WorldWideScience

Sample records for sub-micron refractory metal

  1. Effective Use of Focused Ion Beam (FIB) in Investigating Fundamental Mechanical Properties of Metals at the Sub-Micron Scale

    OpenAIRE

    Greer, Julia R.

    2006-01-01

    Recent advances in the 2-beam focused ion beams technology (FIB) have enabled researchers to not only perform high-precision nanolithography and micro-machining, but also to apply these novel fabrication techniques to investigating a broad range of materials' properties at the submicron and nano-scales. In our work, the FIB is utilized in manufacturing of sub-micron cylinders, or nano-pillars, as well as of TEM cross-sections to directly investigate plasticity of metals at thes...

  2. A Novel Step-Doping Fully-Depleted Silicon-on-Insulator Metal-Oxide-Semiconductor Field-Effect Transistor for Reliable Deep Sub-micron Devices

    Science.gov (United States)

    Elahipanah, Hossein; Orouji, Ali A.

    2009-11-01

    For first time, we report a novel deep sub-micron fully-depleted silicon-on-insulator metal-oxide-semiconductor field-effect-transistor (FD SOI MOSFET) where the channel layer consists of two sections with a step doping (SD) region in order to increase performance and reliability of the device. This new structure that called SD FD SOI structure (SDFD-SOI MOSFET), were used for reaching suitable threshold voltage upon device scaling and reliability improvement. We demonstrate that the electric field was modified in the channel and common peak near the source junction have been reduced in the SDFD-SOI structure. The device demonstrates large enhancements in performance areas such as current drive capability, output resistance, hot-carrier reliability and threshold voltage roll-off. It was found that the device performance is very much dependent upon the SD region parameters. Simulation results show that the proposed structure improved on/off current ratio, and saturated output characteristics compared with conventional SOI structure (C-SOI MOSFET). Also, it was shown that substrate current of SDFD-SOI MOSFET is much lower than the C-SOI MOSFET which presented the lower hot-carrier degradation in proposed MOSFET. Results show that the most short-channel problems in very large scale integrated circuits (VLSI) could be solved and the proposed SDFD-SOI MOSFETs can work very well in deep sub-micron and nanoscale regime.

  3. Binary alloys for refractory-metal brazing

    Science.gov (United States)

    Morris, J. F.

    1974-01-01

    Data on binary-metal eutectics and melting-point minimums have been assembled for use in selecting brazing filler compositions for refractory metals. Data are presented in four tables for ready reference. Brief discussion of problems and potentials of metallides is included in appendix.

  4. Refractory metal particles in refractory inclusions in the Allende meteorite

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, L. H.; Blander, M.

    1980-01-01

    An examination of refractory metal particles in five calcium-aluminum-rich inclusions in the Allende meteorite indicates a complex variety of compositions and large departures from equilibrium. These particles appear to have been primordial condensates which were isolated from the nebula and from each other at different times by cocondensing oxides. Selective diffusion and/or oxidation of the more oxidizable metals (Mo, W, Fe and Ni), phase segregations into different alloy phases (fcc, bcc, hcp and perhaps ordered phases) and the formation of metastable condensates appears to have been involved in the modification of these materials to their present state. Only a small fraction of our observations cannot be reconciled with this picture because of a lack of knowledge of some of the phase equilibria which might have bee involved.

  5. 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.

  6. Scanning SQUID susceptometers with sub-micron spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Kirtley, John R., E-mail: jkirtley@stanford.edu; Rosenberg, Aaron J.; Palmstrom, Johanna C.; Holland, Connor M.; Moler, Kathryn A. [Department of Applied Physics, Stanford University, Stanford, California 94305-4045 (United States); Paulius, Lisa [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252 (United States); Spanton, Eric M. [Department of Physics, Stanford University, Stanford, California 94305-4045 (United States); Schiessl, Daniel [Attocube Systems AG, Königinstraße 11A, 80539 Munich (Germany); Jermain, Colin L.; Gibbons, Jonathan [Department of Physics, Cornell University, Cornell, Ithaca, New York 14853 (United States); Fung, Y.-K.K.; Gibson, Gerald W. [IBM Research Division, T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Huber, Martin E. [Department of Physics, University of Colorado Denver, Denver, Colorado 80217-3364 (United States); Ralph, Daniel C. [Department of Physics, Cornell University, Cornell, Ithaca, New York 14853 (United States); Kavli Institute at Cornell, Ithaca, New York 14853 (United States); Ketchen, Mark B. [OcteVue, Hadley, Massachusetts 01035 (United States)

    2016-09-15

    Superconducting QUantum Interference Device (SQUID) microscopy has excellent magnetic field sensitivity, but suffers from modest spatial resolution when compared with other scanning probes. This spatial resolution is determined by both the size of the field sensitive area and the spacing between this area and the sample surface. In this paper we describe scanning SQUID susceptometers that achieve sub-micron spatial resolution while retaining a white noise floor flux sensitivity of ≈2μΦ{sub 0}/Hz{sup 1/2}. This high spatial resolution is accomplished by deep sub-micron feature sizes, well shielded pickup loops fabricated using a planarized process, and a deep etch step that minimizes the spacing between the sample surface and the SQUID pickup loop. We describe the design, modeling, fabrication, and testing of these sensors. Although sub-micron spatial resolution has been achieved previously in scanning SQUID sensors, our sensors not only achieve high spatial resolution but also have integrated modulation coils for flux feedback, integrated field coils for susceptibility measurements, and batch processing. They are therefore a generally applicable tool for imaging sample magnetization, currents, and susceptibilities with higher spatial resolution than previous susceptometers.

  7. Discovering sub-micron ice particles across Dione' surface

    Science.gov (United States)

    Scipioni, Francesca; Schenk, Pual; Tosi, Federico; Clark, Roger; Dalle Ore, Cristina; Combe, Jean-Philippe

    2015-11-01

    Water ice is the most abundant component of Saturn’s mid-sized moons. However, these moons show an albedo asymmetry - their leading sides are bright while their trailing side exhibits dark terrains. Such differences arise from two surface alteration processes: (i) the bombardment of charged particles from the interplanetary medium and driven by Saturn’s magnetosphere on the trailing side, and (ii) the impact of E-ring water ice particles on the satellites’ leading side. As a result, the trailing hemisphere appears to be darker than the leading side. This effect is particularly evident on Dione's surface. A consequence of these surface alteration processes is the formation or the implantation of sub-micron sized ice particles.The presence of such particles influences and modifies the surfaces' spectrum because of Rayleigh scattering by the particles. In the near infrared range of the spectrum, the main sub-micron ice grains spectral indicators are: (i) asymmetry and (ii) long ward minimum shift of the absorption band at 2.02 μm (iii) a decrease in the ratio between the band depths at 1.50 and 2.02 μm (iv) a decrease in the height of the spectral peak at 2.6 μm (v) the suppression of the Fresnel reflection peak at 3.1 μm and (vi) the decrease of the reflection peak at 5 μm relative to those at 3.6 μm.We present results from our ongoing work mapping the variation of sub-micron ice grains spectral indicators across Dione' surface using Cassini-VIMS cubes acquired in the IR range (0.8-5.1 μm). To characterize the global variations of spectral indicators across Dione' surface, we divided it into a 1°x1° grid and then averaged the band depths and peak values inside each square cell.We will investigate if there exist a correspondence with water ice abundance variations by producing water ice' absorption band depths at 1.25, 1.52 and 2.02 μm, and with surface morphology by comparing the results with ISS color maps in the ultraviolet, visible and infrared

  8. Short range investigation of sub-micron zirconia particles

    Energy Technology Data Exchange (ETDEWEB)

    Caracoche, M C; Martinez, J A [Departamento de Fisica, IFLP, Facultad de Ciencias Exactas, CICPBA, Universidad Nacional de La Plata (Argentina); Rivas, P C [IFLP-CONICET, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata (Argentina); Bondioli, F; Cannillo, V [Dipartimento di Ingegniria dei Materiali e dell' Ambiente, Facolta di Ingegneria, Universita di Modena e Reggio Emilia (Italy); Ferrari, A M, E-mail: cristina@fisica.unlp.edu.a [Dipartimento di Scienza a Metodi dell' Ingegneria, Universita di Modena e Reggio Emilia (Italy)

    2009-05-01

    The Perturbed Angular Correlations technique was used to determine the configurations around Zirconium ions and their thermal behavior in non-aggregated sub-micron zirconia spherical particles. Three residues containing- Zr surroundings were determined for the non-crystalline starting particles, which were identified under the assumption of a certain chemical reactions sequence during synthesis. While the one made up mainly by hydroxyl groups was common to both samples, the two involving mainly organic residues were particle size dependent. Upon crystallization, both samples stabilized in the t'- and t- tetragonal forms and the Xc-cubic form but their amounts and temperatures of appearance were different. On heating, the structure of the smaller particles became gradually monoclinic achieving total degradation upon the subsequent cooling to RT.

  9. Atom Probe Tomography and Its Application to Refractory Metal Nuggets

    Science.gov (United States)

    Daly, L.; Bland, P. A.; Forman, L. V.; Reddy, S. M.; Rickard, W. D. A.; Saxey, D. W.; La Fontaine, A.; Yang, L.; Trimby, P. W.; Cairney, J.; Ringer, S.; Schaefer, B. F.

    2016-08-01

    Atom probe tomography is capable of achieving atomic resolution. This allows us to accurately measure the chemistry of refractory metal nuggets in situ, revealing nanometre scale variations in their chemistry and the presence of sulphur in the alloy.

  10. Directed light fabrication of refractory metals and alloys

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-05-30

    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 (1.06{micro}m), 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.

  11. Directed Light Fabrication of Refractory Metals and Alloys

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-05-14

    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 (1.06{micro}m), 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.

  12. Deformation Behavior of Sub-micron and Micron Sized Alumina Particles in Compression.

    Energy Technology Data Exchange (ETDEWEB)

    Sarobol, Pylin; Chandross, Michael E.; Carroll, Jay; Mook, William; Boyce, Brad; Kotula, Paul Gabriel; McKenzie, Bonnie Beth; Bufford, Daniel Charles; Hall, Aaron Christopher.

    2014-09-01

    The ability to integrate ceramics with other materials has been limited due to high temperature (>800degC) ceramic processing. Recently, researchers demonstrated a novel process , aerosol deposition (AD), to fabricate ceramic films at room temperature (RT). In this process, sub - micro n sized ceramic particles are accelerated by pressurized gas, impacted on the substrate, plastically deformed, and form a dense film under vacuum. This AD process eliminates high temperature processing thereby enabling new coatings and device integration, in which ceramics can be deposited on metals, plastics, and glass. However, k nowledge in fundamental mechanisms for ceramic particle s to deform and form a dense ceramic film is still needed and is essential in advancing this novel RT technology. In this wo rk, a combination of experimentation and atomistic simulation was used to determine the deformation behavior of sub - micron sized ceramic particle s ; this is the first fundamental step needed to explain coating formation in the AD process . High purity, singl e crystal, alpha alumina particles with nominal size s of 0.3 um and 3.0 um were examined. Particle characterization, using transmission electron microscopy (TEM ), showed that the 0.3 u m particles were relatively defect - free single crystals whereas 3.0 u m p articles were highly defective single crystals or particles contained low angle grain boundaries. Sub - micron sized Al 2 O 3 particles exhibited ductile failure in compression. In situ compression experiments showed 0.3um particles deformed plastically, fractured, and became polycrystalline. Moreover, dislocation activit y was observed within the se particles during compression . These sub - micron sized Al 2 O 3 particles exhibited large accum ulated strain (2 - 3 times those of micron - sized particles) before first fracture. I n agreement with the findings from experimentation , a tomistic simulation s of nano - Al 2 O 3 particles showed dislocation slip and

  13. Separating the signal from the noise: Expanding flow cytometry into the sub-micron range.

    Science.gov (United States)

    Cytometry Part A Special Section: Separating the signal from the noise: Expanding flow cytometry into the sub-micron range. The current Cytometry Part A Special Section presents three studies that utilize cytometers to study sub-micron particles. The three studies involve the 1...

  14. Reactions Between MgO-C Refractory, Molten Slag and Metal

    National Research Council Canada - National Science Library

    Li, Zushu; Mukai, Kusuhiro; Tao, Zainan

    2000-01-01

    The behavior of MgO-C refractory-slag-metal system, which is caused by the reactions such as the dissolution of MgO and graphite in the refractory into slag and metal respectively and the generation...

  15. Deciphering sub-micron ice particles on Enceladus surface

    Science.gov (United States)

    Scipioni, F.; Schenk, P.; Tosi, F.; D'Aversa, E.; Clark, R.; Combe, J.-Ph.; Ore, C. M. Dalle

    2017-07-01

    The surface of Saturn's moon Enceladus is composed primarily by pure water ice. The Cassini spacecraft has observed present-day geologic activity at the moon's South Polar Region, related with the formation and feeding of Saturn's E-ring. Plumes of micron-sized particles, composed of water ice and other non-ice contaminants (e.g., CO2, NH3, CH4), erupt from four terrain's fractures named Tiger Stripes. Some of this material falls back on Enceladus' surface to form deposits that extend to the North at ∼40°W and ∼220°W, with the highest concentration found at the South Pole. In this work we analyzed VIMS-IR data to identify plumes deposits across Enceladus' surface through the variation in band depth of the main water ice spectral features. To characterize the global variation of water ice band depths across Enceladus, the entire surface was sampled with an angular resolution of 1° in both latitude and longitude, and for each angular bin we averaged the value of all spectral indices as retrieved by VIMS. The position of the plumes' deposits predicted by theoretical models display a good match with water ice band depths' maps on the trailing hemisphere, whereas they diverge significantly on the leading side. Space weathering processes acting on Enceladus' surface ionize and break up water ice molecules, resulting in the formation of particles smaller than one micron. We also mapped the spectral indices for sub-micron particles and we compared the results with the plumes deposits models. Again, a satisfactory match is observed on the trailing hemisphere only. Finally, we investigated the variation of the depth of the water ice absorption bands as a function of the phase angle. In the visible range, some terrains surrounding the Tiger Stripes show a decrease in albedo when the phase angle is smaller than 10°. This unusual effect cannot be confirmed by near infrared data, since observations with a phase angle lower than 10° are not available. For phase angle

  16. Refractory metal nuggets in different types of cosmic spherules.

    Digital Repository Service at National Institute of Oceanography (India)

    Rudraswami, N.G.; ShyamPrasad, M.; Plane, J.M.C.; Berg, T.; Feng, W.; Balgar, S.

    Out of the three basic cosmic spherule types collected from the seafloor, RMNs (refractory metal nuggets) have been reported from I-type spherules commonly, rarely from S-type spherules and never from the G-type spherules. Nuggets in the I-type...

  17. Acoustic Emission Patterns and the Transition to Ductility in Sub-Micron Scale Laboratory Earthquakes

    Science.gov (United States)

    Ghaffari, H.; Xia, K.; Young, R.

    2013-12-01

    We report observation of a transition from the brittle to ductile regime in precursor events from different rock materials (Granite, Sandstone, Basalt, and Gypsum) and Polymers (PMMA, PTFE and CR-39). Acoustic emission patterns associated with sub-micron scale laboratory earthquakes are mapped into network parameter spaces (functional damage networks). The sub-classes hold nearly constant timescales, indicating dependency of the sub-phases on the mechanism governing the previous evolutionary phase, i.e., deformation and failure of asperities. Based on our findings, we propose that the signature of the non-linear elastic zone around a crack tip is mapped into the details of the evolutionary phases, supporting the formation of a strongly weak zone in the vicinity of crack tips. Moreover, we recognize sub-micron to micron ruptures with signatures of 'stiffening' in the deformation phase of acoustic-waveforms. We propose that the latter rupture fronts carry critical rupture extensions, including possible dislocations faster than the shear wave speed. Using 'template super-shear waveforms' and their network characteristics, we show that the acoustic emission signals are possible super-shear or intersonic events. Ref. [1] Ghaffari, H. O., and R. P. Young. "Acoustic-Friction Networks and the Evolution of Precursor Rupture Fronts in Laboratory Earthquakes." Nature Scientific reports 3 (2013). [2] Xia, Kaiwen, Ares J. Rosakis, and Hiroo Kanamori. "Laboratory earthquakes: The sub-Rayleigh-to-supershear rupture transition." Science 303.5665 (2004): 1859-1861. [3] Mello, M., et al. "Identifying the unique ground motion signatures of supershear earthquakes: Theory and experiments." Tectonophysics 493.3 (2010): 297-326. [4] Gumbsch, Peter, and Huajian Gao. "Dislocations faster than the speed of sound." Science 283.5404 (1999): 965-968. [5] Livne, Ariel, et al. "The near-tip fields of fast cracks." Science 327.5971 (2010): 1359-1363. [6] Rycroft, Chris H., and Eran Bouchbinder

  18. Sub-micron Hard X-ray Fluorescence Imaging of Synthetic Elements

    Science.gov (United States)

    Jensen, Mark P.; Aryal, Baikuntha P.; Gorman-Lewis, Drew; Paunesku, Tatjana; Lai, Barry; Vogt, Stefan; Woloschak, Gayle E.

    2013-01-01

    Synchrotron-based X-ray fluorescence microscopy (SXFM) using hard X-rays focused into sub-micron spots is a powerful technique for elemental quantification and mapping, as well as microspectroscopic measurement such as μ-XANES (X-ray absorption near edge structure). We have used SXFM to image and simultaneously quantify the transuranic element plutonium at the L3 or L2 edge as well as lighter biologically essential elements in individual rat pheochromocytoma (PC12) cells after exposure to the long-lived plutonium isotope 242Pu. Elemental maps reveal that plutonium localizes principally in the cytoplasm of the cells and avoids the cell nucleus, which is marked by the highest concentrations of phosphorus and zinc, under the conditions of our experiments. The minimum detection limit under typical acquisition conditions for an average 202 μm2 cell is 1.4 fg Pu/cell or 2.9 × 10−20 moles Pu/μm2, which is similar to the detection limit of K-edge SXFM of transition metals at 10 keV. Copper electron microscopy grids were used to avoid interference from gold X-ray emissions, but traces of strontium present in naturally occurring calcium can still interfere with plutonium detection using its Lα X-ray emission. PMID:22444530

  19. Refractory metal alloys and composites for space nuclear power systems

    Science.gov (United States)

    Titran, Robert H.; Stephens, Joseph R.; Petrasek, Donald W.

    1988-01-01

    Space power requirements for future NASA and other U.S. missions will range from a few kilowatts to megawatts of electricity. Maximum efficiency is a key goal of any power system in order to minimize weight and size so that the Space Shuttle may be used a minimum number of times to put the power supply into orbit. Nuclear power has been identified as the primary power source to meet these high levels of electrical demand. One method to achieve maximum efficiency is to operate the power supply, energy conservation system, and related components at relatively high temperatures. For systems now in the planning stages, design temperatures range from 1300 K for the immediate future to as high as 1700 K for the advanced systems. NASA Lewis Research Center has undertaken a research program on advanced technology of refractory metal alloys and composites that will provide baseline information for space power systems in the 1900's and the 21st century. Special emphasis is focused on the refractory metal alloys of niobium and on the refractory metal composites which utilize tungsten alloy wires for reinforcement. Basic research on the creep and creep-rupture properties of wires, matrices, and composites are discussed.

  20. Penetration of sub-micron particles into dentinal tubules using ultrasonic cavitation.

    Science.gov (United States)

    Vyas, N; Sammons, R L; Pikramenou, Z; Palin, W M; Dehghani, H; Walmsley, A D

    2017-01-01

    Functionalised silica sub-micron particles are being investigated as a method of delivering antimicrobials and remineralisation agents into dentinal tubules. However, their methods of application are not optimised, resulting in shallow penetration and aggregation. The aim of this study is to investigate the impact of cavitation occurring around ultrasonic scalers for enhancing particle penetration into dentinal tubules. Dentine slices were prepared from premolar teeth. Silica sub-micron particles were prepared in water or acetone. Cavitation from an ultrasonic scaler (Satelec P5 Newtron, Acteon, France) was applied to dentine slices immersed inside the sub-micron particle solutions. Samples were imaged with scanning electron microscopy (SEM) to assess tubule occlusion and particle penetration. Qualitative observations of SEM images showed some tubule occlusion. The particles could penetrate inside the tubules up to 60μm when there was no cavitation and up to ∼180μm when there was cavitation. The cavitation bubbles produced from an ultrasonic scaler may be used to deliver sub-micron particles into dentine. This method has the potential to deliver such particles deeper into the dentinal tubules. Cavitation from a clinical ultrasonic scaler may enhance penetration of sub-micron particles into dentinal tubules. This can aid in the development of novel methods for delivering therapeutic clinical materials for hypersensitivity relief and treatment of dentinal caries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. 40 CFR 471.50 - Applicability; description of the refractory metals forming subcategory.

    Science.gov (United States)

    2010-07-01

    ... refractory metals forming subcategory. 471.50 Section 471.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS FORMING AND METAL POWDERS POINT SOURCE CATEGORY Refractory Metals Forming Subcategory § 471.50 Applicability; description of the...

  2. Analysis and Design of Monolithic Inductors in Sub-micron CMOS

    DEFF Research Database (Denmark)

    Fallesen, Carsten; Jørgensen, Allan

    1997-01-01

    In the last few years the CMOS processes have gone into deep sub-micron channel lengths. This means that it is now possible to make GHz applications in CMOS. In analog GHz applications it is often necessary to have access to inductors. This report describes the development of a physical model of ...

  3. Processing of Refractory Metal Alloys for JOYO Irradiations

    Energy Technology Data Exchange (ETDEWEB)

    RF Luther; ME Petrichek

    2006-02-21

    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.

  4. Synthesis, Structure, and Properties of Refractory Hard-Metal Borides

    Science.gov (United States)

    Lech, Andrew Thomas

    As the limits of what can be achieved with conventional hard compounds, such as tungsten carbide, are nearing reach, super-hard materials are an area of increasing industrial interest. The refractory hard metal borides, such as ReB2 and WB4, offer an increasingly attractive alternative to diamond and cubic boron nitride as a next-generation tool material. In this Thesis, a thorough discussion is made of the progress achieved by our laboratory towards understanding the synthesis, structure, and properties of these extremely hard compounds. Particular emphasis is placed on structural manipulation, solid solution formation, and the unique crystallographic manifestations of what might also be called "super-hard metals".

  5. Sub-micron-sized delafossite CuCrO2 with different morphologies ...

    Indian Academy of Sciences (India)

    40, No. 1, February 2017, pp. 195–199. c Indian Academy of Sciences. DOI 10.1007/s12034-016-1340-6. Sub-micron-sized delafossite CuCrO2 with different morphologies synthesized by nitrate–citric acid sol–gel route. SATISH BOLLOJU1 and RADHAKRISHNAN SRINIVASAN1,2,∗. 1Department of Chemistry, BITS Pilani ...

  6. Directed assembly of conducting polymers on sub-micron templates by electrical fields

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Jia; Wei, Ming [National Science Foundation (NSF) Nanoscale Science and Engineering Center for High-Rate Nanomanufacturing, University of Massachusetts Lowell, Lowell, MA 01854 (United States); Busnaina, Ahmed [National Science Foundation (NSF) Nanoscale Science and Engineering Center for High-Rate Nanomanufacturing, Northeastern University, Boston, MA 02115 (United States); Barry, Carol [National Science Foundation (NSF) Nanoscale Science and Engineering Center for High-Rate Nanomanufacturing, University of Massachusetts Lowell, Lowell, MA 01854 (United States); Mead, Joey, E-mail: Joey_Mead@uml.edu [National Science Foundation (NSF) Nanoscale Science and Engineering Center for High-Rate Nanomanufacturing, University of Massachusetts Lowell, Lowell, MA 01854 (United States)

    2013-02-20

    Highlights: Black-Right-Pointing-Pointer Nanoscale patterns with dimensions of assembled PANi down to 100 nm were fabricated. Black-Right-Pointing-Pointer We use electrophoretic and dielectrophoretic assembly to deposit PANi. Black-Right-Pointing-Pointer Electrophoretic and dielectrophoretic assembly of PANi finished in less than 1 min. Black-Right-Pointing-Pointer Effect of process parameters on assembly of PANi onto nanoscale pattern was studied. Black-Right-Pointing-Pointer The assembled PANi can be transferred to other flexible substrates. - Abstract: Patterning of conducting polymer into sub-micron patterns over large areas at high rate and low cost is significant for commercial manufacturing of novel devices. Electrophoretic and dielectrophoretic assembly provide an easily scaled approach with high fabrication rates. In this work, electrophoretic and dielectrophoretic assembly were used to assemble polyaniline (PANi) into multiscale sub-micron size patterns in less than 1 min. The process was controlled by assembly time, amplitude, and frequency of the electric field. Dielectrophoretic assembly is preferable for manufacturing as it reduces damage to the templates used to control the assembly. Using this method, sub-micron patterns with dimensions of the assembled PANi down to 100 nm were fabricated over large areas in short times. The assembled PANi was further transferred to other flexible polymer substrates by a thermoforming process, providing a fast, easily controlled and promising approach for fabrication of nanoscale devices.

  7. Some possible filler alloys with low vapor pressures for refractory-metal brazing

    Science.gov (United States)

    Morris, J. F.

    1973-01-01

    A compilation of eutectics and melting-point minima for binary combinations of metals having vapor pressures below 10 to the minus 10th power torr at 1500 degrees K and .00005 torr at 2000 degree K is presented. These compositions and others near them on their phase diagrams are potential special brazing fillers for refractory metals. Some possible problems and advantages for fusion bonds of such mixtures are indicated. Evaluations of brazing fillers containing refractory metals are reported.

  8. Sub-micron Cu/SSZ-13: Synthesis and application as selective catalytic reduction (SCR) catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Prodinger, Sebastian; Derewinski, Miroslaw A.; Wang, Yilin; Washton, Nancy M.; Walter, Eric D.; Szanyi, János; Gao, Feng; Wang, Yong; Peden, Charles H. F.

    2017-02-01

    For the first time, sub-micron Cu/SSZ-13, obtained by modifying an existing synthesis procedure, was shown to be an effective and stable catalyst for selective catalytic reduction reactions, such as NO reduction. Characterization of the materials with X-ray diffraction, N2-physisorption and 27Al MAS NMR shows that hydrothermal aging, simulating SCR reaction conditions, is more destructive in respect to dealumination for smaller particles prior to Cu-exchange. However, the catalytic performance and hydrothermal stability for Cu/SSZ-13 is independent of the particle size. In particular, the stability of tetrahedral framework Al is improved in the sub-micron Cu/SSZ-13 catalysts of comparable Cu loading. This indicates that variations in the Al distribution for different SSZ-13 synthesis procedures have a more critical influence on stabilizing isolated Cu-ions during harsh hydrothermal aging than the particle size. This study is of high interest for applications in vehicular DeNOx technologies where high loadings of active species on wash coats can be achieved by using sub-micron Cu/SSZ-13. The authors would like to thank B. W. Arey and J. J. Ditto for performing electron microscope imaging. The authors gratefully acknowledge the US Department of Energy (DOE), Energy Efficiency and Renewable Energy, Vehicle Technologies Office for the support of this work. S. P and M. A. D also acknowledge support by the Materials Synthesis and Simulation Across Scales (MS3 Initiative) conducted under the Laboratory Directed Research & Development Program at PNNL. The research described in this paper was performed in the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US DOE by Battelle.

  9. Breakdown resistance of refractory metals compared to copper

    CERN Document Server

    Taborelli, M; Kildemo, M

    2004-01-01

    The behaviour of Mo, W and Cu with respect to electrical breakdown in ultra high vacuum has been investigated by means of a capacitor discharge method. The maximum stable electric field without breakdown and the field enhancement factor, beta have been measured between electrodes of the same material in a sphere/plane geometry for anode and cathode, respectively. The maximum stable field increases as a function of the number of breakdown events for W and Mo. In contrast, no systematic increase is observed for Cu. The highest values obtained are typically 500 MV/m for W, 350 MV/m for Mo and only 180 MV/m for Cu. This conditioning, found for the refractory metals, corresponds to a simultaneous decrease of beta and is therefore related to the field emission properties of the surface and their modification upon sparking. Accordingly, high beta values and no applicable field increase occur for Cu even after repeated breakdown. The results are compared with RF breakdown experiments [1] performed on prototype 30 GHz...

  10. Spectroscopic and magnetic properties of neodymium doped in GdPO{sub 4} sub-micron-stars prepared by solvothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, G.A., E-mail: ajith@gakumar.net [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, 78249 (United States); Balli, Nicolas R. [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, 78249 (United States); Kailasnath, M. [International School of Photonics, Cochin University of Science and Technology, Kochi, 682022 (India); Mimun, L. Christopher [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, 78249 (United States); Dannangoda, Chamath; Martirosyan, Karen S. [University of Texas at Rio Grande Valley, Brownsville, TX, 78520 (United States); Santhosh, C. [Department of Atomic and Molecular Spectroscopy, Manipal University, Manipal, 576104 (India); Sardar, Dhiraj K. [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, 78249 (United States)

    2016-07-05

    Neodymium-doped gadolinium orthophosphate (GdPO{sub 4}:Nd{sup 3+}) luminomagnetic sub-micron-stars were prepared by solvothermal method using metal nitrates and phosphoric acid. Monoclinic star shaped in six lobed sub-micron-stars with 600 nm length is obtained with uniform particle size distribution. After heat-treatment at 800 °C for 1 h in air, the stars separate into isolated petal shaped particles and show characteristic emission bands of Nd{sup 3+} with the strongest emission at 1064 nm. The emission intensities and fluorescence decay times are dependent on the Nd{sup 3+} concentration with the highest emission intensity and longest fluorescence decay time of 311 μs at 1064 nm with 0.5 mol% Nd{sup 3+}. Under 808 nm excitation with 12 W/cm{sup 2} power density a quantum yield of 9% was obtained for the 1.0 mol% Nd{sup 3+}. The presence of paramagnetic Gd{sup 3+} gives magnetic properties to the phosphor with a calculated magnetic moment of 1510 and 107,965 Bohr magneton at 300 and 5 K, respectively. - Highlights: • Star shaped Nd doped GdPO{sub 4} sub-micron phosphor particles are prepared for the first time. • Particles show both optical and magnetic properties. • Under 808 nm excitation near infrared emission was observed at 1064 nm with 9% quantum yield. • Magnetic moment of the particle was 1510 and 107,965 Bohr magneton at 300 and 5 K, respectively.

  11. Impact-disrupted gunshot residue: A sub-micron analysis using a novel collection protocol

    Directory of Open Access Journals (Sweden)

    V. Spathis

    2017-06-01

    Full Text Available The analysis of gunshot residue (GSR has played an integral role within the legal system in relation to shooting cases. With a characteristic elemental composition of lead, antimony, barium, and a typically discriminative spheroidal morphology, the presence and distribution of GSR can aid in firearm investigations. In this experiment, three shots of low velocity rim-fire ammunition were fired over polished silicon collection substrates placed at six intervals over a 100 cm range. The samples were analysed using a Field Emission Gun Scanning Electron Microscope (FEG-SEM in conjunction with an X-flash Energy Dispersive X-ray (EDX detector, allowing for GSR particle analyses of composition and structure at the sub-micron level. The results of this experiment indicate that although classic spheroidal particles are present consistently throughout the entire range of samples their sizes vary significantly, and at certain distances from the firearm particles with an irregular morphology were discerned, forming “impact-disrupted” GSR particles, henceforth colloquially referred to as “splats”. Upon further analysis, trends with regards to the formation of these splat particles were distinguished. An increase in splat frequency was observed starting at 10 cm from the firearm, with 147 mm−2 splat density, reaching a maximal flux at 40 cm (451 mm−2, followed by a gradual decrease to the maximum range sampled. Moreover, the structural morphology of the splats changes throughout the sampling range. At the distances closest to the firearm, molten-looking particles were formed, demonstrating the metallic residues were in a liquid state when their flight path was disrupted. However, at increased distances-primarily where the discharge plume was at maximum dispersion and moving away from the firearm, the residues have had time to cool in-fight resulting in semi-congealed and solid particles that subsequently disrupted upon impact, forming more

  12. Laser smoothing of sub-micron grooves in hydroxyl-rich fused silica

    Energy Technology Data Exchange (ETDEWEB)

    Shen Nan [Lawrence Livermore National Laboratory, 7000 East Avenue, L-491, Livermore, CA 94550-9234 (United States); Matthews, Manyalibo J., E-mail: ibo@llnl.gov [Lawrence Livermore National Laboratory, 7000 East Avenue, L-491, Livermore, CA 94550-9234 (United States); Fair, James E.; Britten, Jerald A.; Nguyen, Hoang T.; Cooke, Diane; Elhadj, Selim; Yang, Steven T. [Lawrence Livermore National Laboratory, 7000 East Avenue, L-491, Livermore, CA 94550-9234 (United States)

    2010-04-01

    Nano- to micrometer-sized surface defects on UV-grade fused silica surfaces are known to be effectively smoothed through the use of high-temperature localized CO{sub 2} laser heating, thereby enhancing optical properties. However, the details of the mass transport and the effect of hydroxyl content on the laser smoothing of defective silica at sub-micron length scales are still not completely understood. In this study, we examine the morphological evolution of sub-micron, dry-etched periodic surface structures on type II and type III SiO{sub 2} substrates under 10.6 {mu}m CO{sub 2} laser irradiation using atomic force microscopy (AFM). In situ thermal imaging was used to map the transient temperature field across the heated region, allowing assessment of the T-dependent mass transport mechanisms under different laser-heating conditions. Computational fluid dynamics simulations correlated well with experimental results, and showed that for large effective capillary numbers (N{sub c} > 2), surface diffusion is negligible and smoothing is dictated by capillary action, despite the relatively small spatial scales studied here. Extracted viscosity values over 1700-2000 K were higher than the predicted bulk values, but were consistent with the surface depletion of OH groups, which was confirmed using confocal Raman microscopy.

  13. The surface characterisation and comparison of two potential sub-micron, sugar bulking excipients for use in low-dose, suspension formulations in metered dose inhalers.

    Science.gov (United States)

    James, Jeff; Crean, Barry; Davies, Martyn; Toon, Richard; Jinks, Phil; Roberts, Clive J

    2008-09-01

    This study compares the surface characteristics and surface energetics of two potential bulking excipients, anhydrous sub-micron alpha-lactose and sub-micron sucrose, for use with low-dose, suspension formulations in pressurised metered dose inhalers (pMDIs). Both sub-micron bulking excipients are processed from parent materials (alpha-lactose monohydrate/alpha-lactose monohydrate and silk grade sucrose, respectively) so the surface characteristics of each material were determined and compared. Additionally, the surface energetics and adhesive interactions between each sub-micron bulking excipient and some chosen active pharmaceutical ingredients (APIs) used in pMDI formulations were also determined. From this data, it was possible to predict the potential degree of interaction between the APIs and each sub-micron bulking excipient, thus determining suitable API-excipient combinations for pMDI formulation optimisation. Salmon calcitonin was also investigated as a potential API due to the current interest in, and the potential low-dose requirements for, the pulmonary delivery of proteins. The size and morphology of each sub-micron excipient (and parent materials) were determined using scanning electron microscopy (SEM) and the crystalline nature of each sub-micron excipient and parent material was assessed using X-ray diffraction (XRD). The surface chemistry of each sub-micron excipient was analysed using X-ray photoelectron spectroscopy (XPS). The surface energies of each sub-micron excipient, along with their respective parent materials and any intermediates, were determined using two techniques. The surface energies of these materials were determined via (a) single particle adhesive interactions using atomic force microscopy (AFM) and (b) 'bulk' material surface interactions using contact angle measurements (CA). From the CA data, it was possible to calculate the theoretical work of adhesion values for each API-excipient interaction using the surface component

  14. The fabrication of integrated carbon pipes with sub-micron diameters

    Science.gov (United States)

    Kim, B. M.; Murray, T.; Bau, H. H.

    2005-08-01

    A method for fabricating integrated carbon pipes (nanopipettes) of sub-micron diameters and tens of microns in length is demonstrated. The carbon pipes are formed from a template consisting of the tip of a pulled alumino-silicate glass capillary coated with carbon deposited from a vapour phase. This method renders carbon nanopipettes without the need for ex situ assembly and facilitates parallel production of multiple carbon-pipe devices. An electric-field-driven transfer of ions in a KCl solution through the integrated carbon pipes exhibits nonlinear current-voltage (I-V) curves, markedly different from the Ohmic I-V curves observed in glass pipettes under similar conditions. The filling of the nanopipette with fluorescent suspension is also demonstrated.

  15. In situ analysis of Refractory Metal Nuggets in carbonaceous chondrites

    Science.gov (United States)

    Daly, Luke; Bland, Phil A.; Dyl, Kathryn A.; Forman, Lucy V.; Evans, Katy A.; Trimby, Patrick W.; Moody, Steve; Yang, Limei; Liu, Hongwei; Ringer, Simon P.; Ryan, Christopher G.; Saunders, Martin

    2017-11-01

    Micrometre to sub-micrometre-scale alloys of platinum group elements (PGEs) known as Refractory Metal Nuggets (RMNs) have been observed in primitive meteorites. The Australian Synchrotron X-ray Fluorescence (XRF) beamline, in tandem with the Maia detector, allows rapid detection of PGEs in concentrations as low as 50-100 ppm at 2 μm resolution. Corroborating these analyses with traditional electron microscopy techniques, RMNs can be rapidly identified in situ within carbonaceous chondrites. These results dispute the assumption of most previous studies: that RMNs are unique to Ca-Al-rich inclusions (CAIs). We find that RMNs are, in fact, observed within all components of carbonaceous chondrites, such as the matrix, chondrules (consistent with observations from Schwander et al. (2015b) and Wang et al. (2007)), and sulphides; though the majority of RMNs are still found in CAIs. The chemistry of RMNs reveals a complex diversity of compositions, which nevertheless averages to CI chondrite abundance ratios. This implies that RMNs are the dominant, if not sole host phase for PGEs. One hundred and thirteen RMNs from this study are combined with reported compositions in the literature, and compared to condensation model compositions similar to Berg et al. (2009), RMNs derived experimentally by precipitation (Schwander et al., 2015a), host phase and host meteorite. Comparisons reveal only weak correlations between parent body processes (sulphidation) and nebular processes (condensation and precipitation) with RMN compositions. It appears that none of these processes acting in isolation or in tandem can explain the diversity observed in the RMN population. Our interpretation is that the Solar Nebula inherited an initially compositionally diverse population of RMNs from the Giant Molecular Cloud; that a variety of Solar System processes have acted on that population; but none have completely homogenised it. Most RMNs have experienced disk and asteroidal processing, but some

  16. Multifunctional Metallic and Refractory Materials for Energy Efficient Handling of Molten Metals

    Energy Technology Data Exchange (ETDEWEB)

    Xingbo Liu; Ever Barbero; Bruce Kang; Bhaskaran Gopalakrishnan; James Headrick; Carl Irwin

    2009-02-06

    The goal of the project was to extend the lifetime of hardware submerged in molten metal by an order of magnitude and to improve energy efficiency of molten metal handling process. Assuming broad implementation of project results, energy savings in 2020 were projected to be 10 trillion BTU/year, with cost savings of approximately $100 million/year. The project team was comprised of materials research groups from West Virginia University and the Missouri University of Science and Technology formerly University of Missouri – Rolla, Oak Ridge National Laboratory, International Lead and Zinc Research Organization, Secat and Energy Industries of Ohio. Industry partners included six suppliers to the hot dip galvanizing industry, four end-user steel companies with hot-dip Galvanize and/or Galvalume lines, eight refractory suppliers, and seven refractory end-user companies. The results of the project included the development of: (1) New families of materials more resistant to degradation in hot-dip galvanizing bath conditions were developed; (2) Alloy 2020 weld overlay material and process were developed and applied to GI rolls; (3) New Alloys and dross-cleaning procedures were developed for Galvalume processes; (4) Two new refractory compositions, including new anti-wetting agents, were identified for use with liquid aluminum alloys; (5) A new thermal conductivity measurement technique was developed and validated at ORNL; (6) The Galvanizing Energy Profiler Decision Support System (GEPDSS)at WVU; Newly Developed CCW Laser Cladding Shows Better Resistance to Dross Buildup than 316L Stainless Steel; and (7) A novel method of measuring the corrosion behavior of bath hardware materials. Project in-line trials were conducted at Southwire Kentucky Rod and Cable Mill, Nucor-Crawfordsville, Nucor-Arkansas, Nucor-South Carolina, Wheeling Nisshin, California Steel, Energy Industries of Ohio, and Pennex Aluminum. Cost, energy, and environmental benefits resulting from the project

  17. Fabrication and Characterization of Brazed Joints for SiC-Metallic Systems Utilizing Refractory Metals

    Science.gov (United States)

    Coddington, Bryan; Asthana, Rajiv; Halbig, Michael C.; Singh, M.

    2011-01-01

    Metal to ceramic joining plays a key role for the integration of ceramics into many nuclear, ground and aero based technologies. In order to facilitate these technologies, the active metal brazing of silicon carbide (CVD beta-SiC, 1.1 mm thick, and hot-pressed alpha-SiC, 3 mm thick) to the refractory metals molybdenum and tungsten using active braze alloys was studied. The joint microstructure, composition, and microhardness were evaluated by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and Knoop hardness testing. The braze alloys, Cusil-ABA, Ticusil and Copper-ABA, all formed sound joints with excellent wetting and chemical bonding with the SiC substrate. Despite the close thermal expansion match between the metal substrates and SiC, hairline cracks formed in alpha-SiC while beta-SiC showed no signs of residual stress cracking. The use of ductile interlayers to reduce the effect from residual stresses was investigated and joints formed with copper as an interlayer produced crack free systems utilizing both CVD and hot-pressed SiC.

  18. Structure and properties of transition metal-metalloid glasses based on refractory metals

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, W.L.; Williams, A.R.

    1979-01-01

    The structure and properties of several new transition metal-metalloid (TM/sub 1-x/M/sub x/) metallic glasses based on refractory transition metals (e.g. Mo, W, Ru etc.) have been systemically investigated as a function of composition. The structure of the alloys has been investigated by x-ray diffraction methods and measurements of superconducting properties, electrical resistivity, density, hardness, and mechanical behavior were made. These data are used in developing a novel description of the structure of TM/sub 1-x/M/sub x/ glasses. The experimental evidence suggests that an ideal amorphous phase forms at a specific composition x/sub c/ and that this phase has a well defined atomic short range order. For metallic glasses having x < x/sub c/ (metalloid poor glasses) vacancy-like defects form, which are characterized by the excess volume which they contribute to the glass. Another, as yet unspecified defect appears to form in glasses with x > x/sub c/. This novel picture can explain the variation of many properties of these glasses with metalloid concentration.

  19. High density-high purity graphite prepared by hot isostatic pressing in refractory metal containers

    Science.gov (United States)

    Hoenig, C.L.

    1994-08-09

    Porous graphite in solid form is hot isostatically pressed in a refractory metal container to produce a solid graphite monolith with a bulk density greater than or equal to 2.10 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed, chemically vapor deposited, or coated by some other suitable means onto graphite. Hot isostatic pressing at 2,200 C and 30 KSI (206.8 MPa) argon pressure for two hours produces a bulk density of 2.10 g/cc. Complex shapes can be made. 1 fig.

  20. A Nordic project on high speed low power design in sub-micron CMOS technology for mobile phones

    DEFF Research Database (Denmark)

    Olesen, Ole

    This paper is a survey paper presenting the Nordic CONFRONT project and reporting some results from the group at CIE/DTU, Denmark. The objective of the project is to demonstrate the feasibility of sub-micron CMOS for the realisation of RF front-end circuits operating at frequencies in the 1...

  1. Water ice and sub-micron ice particles on Tethys and Mimas

    Science.gov (United States)

    Scipioni, Francesca; Nordheim, Tom; Clark, Roger Nelson; D'Aversa, Emiliano; Cruikshank, Dale P.; Tosi, Federico; Schenk, Paul M.; Combe, Jean-Philippe; Dalle Ore, Cristina M.

    2017-10-01

    IntroductionWe present our ongoing work, mapping the variation of the main water ice absorption bands, and the distribution of the sub-micron particles, across Mimas and Tethys’ surfaces using Cassini-VIMS cubes acquired in the IR range (0.8-5.1 μm). We present our results in the form of maps of variation of selected spectral indicators (depth of absorption bands, reflectance peak height, spectral slopes).Data analysisVIMS acquires hyperspectral data in the 0.3-5.1 μm spectral range. We selected VIMS cubes of Tethys and Mimas in the IR range (0.8-5.1 μm). For all pixels in the selected cubes, we measured the band depths for water-ice absorptions at 1.25, 1.5 and 2.02 μm and the height of the 3.6 μm reflection peak. Moreover, we considered the spectral indictors for particles smaller than 1 µm [1]: (i) the 2 µm absorption band is asymmetric and (ii) it has the minimum shifted to longer λ (iii) the band depth ratio 1.5/2.0 µm decreases; (iv) the reflection peak at 2.6 µm decreases; (v) the Fresnel reflection peak is suppressed; (vi) the 5 µm reflectance is decreased relative to the 3.6 µm peak. To characterize the global variation of water-ice band depths, and of sub-micron particles spectral indicators, across Mimas and Tethys, we sampled the two satellites’ surfacees with a 1°x1° fixed-resolution grid and then averaged the band depths and peak values inside each square cell.3. ResultsFor both moons we find that large geologic features, such as the Odysseus and Herschel impact basins, do not correlate with water ice’s abundance variation. For Tethys, we found a quite uniform surface on both hemispheres. The only deviation from this pattern shows up on the trailing hemisphere, where we notice two north-oriented, dark areas around 225° and 315°. For Mimas, the leading and trailing hemispheres appear to be quite similar in water ice abundance, the trailing portion having water ice absorption bands lightly more suppressed than the leading side

  2. Refractory metals welded or brazed with tungsten inert gas equipment

    Science.gov (United States)

    Wisner, J. P.

    1965-01-01

    Appropriate brazing metals and temperatures facilitate the welding or brazing of base metals with tungsten inert gas equipment. The highest quality bond is obtained when TIG welding is performed in an inert atmosphere.

  3. Large area sub-micron chemical imaging of magnesium in sea urchin teeth.

    Science.gov (United States)

    Masic, Admir; Weaver, James C

    2015-03-01

    The heterogeneous and site-specific incorporation of inorganic ions can profoundly influence the local mechanical properties of damage tolerant biological composites. Using the sea urchin tooth as a research model, we describe a multi-technique approach to spatially map the distribution of magnesium in this complex multiphase system. Through the combined use of 16-bit backscattered scanning electron microscopy, multi-channel energy dispersive spectroscopy elemental mapping, and diffraction-limited confocal Raman spectroscopy, we demonstrate a new set of high throughput, multi-spectral, high resolution methods for the large scale characterization of mineralized biological materials. In addition, instrument hardware and data collection protocols can be modified such that several of these measurements can be performed on irregularly shaped samples with complex surface geometries and without the need for extensive sample preparation. Using these approaches, in conjunction with whole animal micro-computed tomography studies, we have been able to spatially resolve micron and sub-micron structural features across macroscopic length scales on entire urchin tooth cross-sections and correlate these complex morphological features with local variability in elemental composition. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Chemical Mapping of Proterozoic Organic Matter at Sub-Micron Spatial Resolution

    Science.gov (United States)

    Oehler, Dorothy Z.; Robert, Francois; Mostefaoui, Smail; Meibom, Anders; Selo, Madeleine; McKay, David S.

    2006-01-01

    We have used a NanoSIMS ion microprobe to map sub-micron-scale distributions of carbon, nitrogen, sulfur, silicon, and oxygen in organic microfossils and laminae from the approximately 0.85 Ga Bitter Springs Formation of Australia. The data provide clues about the original chemistry of the microfossils, the silicification process, and biosignatures of specific microorganisms and microbial communities. Chemical maps of fossil unicells and filaments reveal distinct wall-and sheath-like structures enriched in C, N and S, consistent with their accepted biological origin. Surprisingly, organic laminae, previously considered to be amorphous, also exhibit filamentous and apparently compressed spheroidal structures defined by strong enrichments in C, N and S. By analogy to data from the well-preserved microfossils, these structures are interpreted as being of biological origin, most likely representing densely packed remnants of microbial mats. Because the preponderance of organic matter in Precambrian sediments is similarly "amorphous," our findings open a large body of generally neglected material to in situ structural, chemical, and isotopic study. Our results also offer new criteria for assessing biogenicity of problematic kerogenous materials and thus can be applied to assessments of poorly preserved or fragmentary organic residues in early Archean sediments and any that might occur in meteorites or other extraterrestrial samples.

  5. Scalable Sub-micron Patterning of Organic Materials Toward High Density Soft Electronics.

    Science.gov (United States)

    Kim, Jaekyun; Kim, Myung-Gil; Kim, Jaehyun; Jo, Sangho; Kang, Jingu; Jo, Jeong-Wan; Lee, Woobin; Hwang, Chahwan; Moon, Juhyuk; Yang, Lin; Kim, Yun-Hi; Noh, Yong-Young; Jaung, Jae Yun; Kim, Yong-Hoon; Park, Sung Kyu

    2015-09-28

    The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. In this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. The successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics.

  6. Laser smoothing of sub-micron grooves in hydroxyl-rich fused silica

    Energy Technology Data Exchange (ETDEWEB)

    Shen, N; Matthews, M J; Fair, J E; Britten, J A; Nguyen, H T; Cooke, D; Elhadj, S; Yang, S T

    2009-10-30

    Nano- to micrometer-sized surface defects on UV-grade fused silica surfaces are known to be effectively smoothed through the use of high-temperature localized CO{sub 2} laser heating, thereby enhancing optical properties. However, the details of the mass transport and the effect of hydroxyl content on the laser smoothing of defective silica at submicron length scales is still not completely understood. In this study, we examine the morphological evolution of sub-micron, dry-etched periodic surface structures on type II and type III SiO{sub 2} substrates under 10.6 {micro}m CO{sub 2} laser irradiation using atomic force microscopy (AFM). In-situ thermal imaging was used to map the transient temperature field across the heated region, allowing assessment of the T-dependent mass transport mechanisms under different laser-heating conditions. Computational fluid dynamics simulations correlated well with experimental results, and showed that for large effective capillary numbers (N{sub c} > 2), surface diffusion is negligible and smoothing is dictated by capillary action, despite the relatively small spatial scales studied here. Extracted viscosity values over 1700-2000K were higher than the predicted bulk values, but were consistent with the surface depletion of OH groups, which was confirmed using confocal Raman microscopy.

  7. Ultrathin oxides for the SCM analysis of sub-micron doping profiles

    Energy Technology Data Exchange (ETDEWEB)

    Ciampolini, Lorenzo; Bertin, F.; Hartmann, J.M.; Rochat, N.; Holliger, Ph.; Laugier, F.; Chabli, A

    2003-09-15

    Attenuated total reflection (ATR) spectroscopy and spectroscopic ellipsometry (SE) have been used to characterize oxides used for the scanning capacitance microscopy (SCM) technique. SCM has been used to study boron and phosphorous doped Si test structures epitaxially grown on (100) Si substrates. SCM samples have one-dimensional (1D) doping profiles with sub-micron features, with staircase-like steps in the unipolar sample and a smoother profile in the bipolar sample, as obtained by secondary ion mass spectrometry (SIMS) profiling. Cross-sectional SCM results obtained on samples oxidized by the standard low-temperature UV-ozone method are presented, discussed and compared to results obtained on cleaved samples oxidized by a simple exposure to air. The results show that the native oxide covering a (110) cleaved section may yield SCM images of sufficient quality, with no contrast reversal on a wide range of doping levels, as well as observed on sections prepared with the UV-ozone technique. However, the long-term stability of the SCM signal on native oxides is poor, and UV-ozone oxidation can be used to recover a valid SCM signal. Realistic ultrathin oxide thickness data obtained by SE on (110) substrates are presented together with ATR results, which confirm the superior quality of UV-ozone oxides with respect to other kinds of oxides.

  8. PARTITIONING OF THE REFRACTORY METALS, NICKEL AND CHROMIUM, IN COMBUSTION SYSTEMS

    Science.gov (United States)

    The partitioning of nickel (Ni) and Chromium (Cr) in combustion systems was investigated theoretically and experimentally. In comparison to other volatile and semi-volatile metals, both Ni and Cr are usually considered to be refractory (non-volatile). Theoretical predictions ba...

  9. Condensation of refractory metals in asymptotic giant branch and other stellar environments

    Energy Technology Data Exchange (ETDEWEB)

    Schwander, D.; Berg, T.; Schönhense, G.; Ott, U., E-mail: schwandd@uni-mainz.de [Institut für Physik, Johannes Gutenberg-Universität, Staudingerweg 7, D-55128 Mainz (Germany)

    2014-09-20

    The condensation of material from a gas of solar composition has been extensively studied, but less so condensation in the environment of evolved stars, which has been mainly restricted to major compounds and some specific element groups such as the Rare Earth elements. Also of interest, however, are refractory metals like Mo, Ru, Os, W, Ir, and Pt, which may condense to form refractory metal nuggets (RMNs) like the ones that have been found in association with presolar graphite. We have performed calculations describing the condensation of these elements in the outflows of s-process enriched AGB stars as well as from gas enriched in r-process products. While in carbon-rich environments (C > O), the formation of carbides is expected to consume W, Mo, and V (Lodders and Fegley), the condensation sequence for the other refractory metals under these conditions does not significantly differ from the case of a cooling gas of solar composition. The composition in detail, however, is significantly different due to the completely different source composition. Condensation from an r-process enriched source differs less from the solar case. Elemental abundance ratios of the refractory metals can serve as a guide for finding candidate presolar grains among the RMNs in primitive meteorites—most of which have a solar system origin—for confirmation by isotopic analysis. We apply our calculations to the case of the four RMNs found by Croat et al., which may very well be presolar.

  10. Sub-micron opto-chemical probes for studying living neurons

    Science.gov (United States)

    Hossein-Zadeh, M.; Delgado, J.; Schweizer, F.; Lieberman, R.

    2017-02-01

    We have fabricated sub-micron opto-chemical probes for pH, oxygen and calcium monitoring and demonstrated their application in intracellular and extracellular monitoring of neurons (cortical neuronal cultures and acute hippocampal slices). Using these probes, we have measured extracellular pH in the stratum radiatum of the CA1 region of mouse hippocampus upon stimulation of presynaptic Schaffer collateral axons. Synaptic transmission was monitored using standard electrophysiological techniques. We find that the local pH transiently changes in response to synaptic stimulation. In addition, the geometry of the functionalized region on the probe combined with high sensitivity imaging enables simultaneous monitoring of spatially adjacent but distinct compartments. As proof of concept we impaled cultured neurons with the probe measured calcium and pH inside as well as directly outside of neurons as we changed the pH and calcium concentration in the physiological solution in the perfusion chamber. As such these probes can be used to study the impact of the environment on both cellular and extra-cellular space. Additionally as the chemical properties of the surrounding medium can be controlled and monitored with high precision, these probes enable differential measurement of the target parameter referenced to a stable bath. This approach eliminates the uncertainties associated with non-chemical fluctuations in the fluorescent emission and result in a self-calibrated opto-chemical probe. We have also demonstrated multifunctional probes that are capable of measuring up to three parameters in the extracellular space in brain slices.

  11. Sub-micron resolution high-speed spectral domain optical coherence tomography in quality inspection for printed electronics

    Science.gov (United States)

    Czajkowski, J.; Lauri, J.; Sliz, R.; Fält, P.; Fabritius, T.; Myllylä, R.; Cense, B.

    2012-04-01

    We present the use of sub-micron resolution optical coherence tomography (OCT) in quality inspection for printed electronics. The device used in the study is based on a supercontinuum light source, Michelson interferometer and high-speed spectrometer. The spectrometer in the presented spectral-domain optical coherence tomography setup (SD-OCT) is centered at 600 nm and covers a 400 nm wide spectral region ranging from 400 nm to 800 nm. Spectra were acquired at a continuous rate of 140,000 per second. The full width at half maximum of the point spread function obtained from a Parylene C sample was 0:98 m. In addition to Parylene C layers, the applicability of sub-micron SD-OCT in printed electronics was studied using PET and epoxy covered solar cell, a printed RFID antenna and a screen-printed battery electrode. A commercial SD-OCT system was used for reference measurements.

  12. Preliminary Investigations of Joining Technologies for Attaching Refractory Metals to Ni-Based Superalloys

    Science.gov (United States)

    Gould, Jerry E.; Ritzert, Frank J.; Loewenthal, William S.

    2006-01-01

    In this study, a range of joining technologies has been investigated for creating attachments between refractory metal and Ni-based superalloys. Refractory materials of interest include Mo-47%Re, T-111, and Ta-10%W. The Ni-based superalloys include Hastelloy X and MarM 247. During joining with conventional processes, these materials have potential for a range of solidification and intermetallic formation-related defects. For this study, three non-conventional joining technologies were evaluated. These included inertia welding, electro-spark deposition (ESD) welding, and magnetic pulse welding (MPW). The developed inertia welding practice closely paralleled that typically used for the refractory metals alloys. Metallographic investigations showed that forging during inertia welding occurred predominantly on the nickel base alloy side. It was also noted that at least some degree of forging on the refractory metal side of the joint was necessary to achieve consistent bonding. Both refractory metals were readily weldable to the Hastelloy X material. When bonding to the MarM 247, results were inconsistent. This was related to the higher forging temperatures of the MarM 247, and subsequent reduced deformation on that material during welding. ESD trials using a Hastelloy X filler were successful for all material combinations. ESD places down very thin (5- to 10- m) layers per pass, and interactions between the substrates and the fill were limited (at most) to that layer. For the refractory metals, the fill only appeared to wet the surface, with minimal dilution effects. Microstructures of the deposits showed high weld metal integrity with maximum porosity on the order of a few percent. Some limited success was also obtained with MPW. In these trials, only the T-111 tubes were used. Joints were possible for the T-111 tube to the Hastelloy X bar stock, but the stiffness of the tube (resisting collapse) necessitated the use of very high power levels. These power levels

  13. Prescribed 3-D Direct Writing of Suspended Micron/Sub-micron Scale Fiber Structures via a Robotic Dispensing System.

    Science.gov (United States)

    Yuan, Hanwen; Cambron, Scott D; Keynton, Robert S

    2015-06-12

    A 3-axis dispensing system is utilized to control the initiating and terminating fiber positions and trajectory via the dispensing software. The polymer fiber length and orientation is defined by the spatial positioning of the dispensing system 3-axis stages. The fiber diameter is defined by the prescribed dispense time of the dispensing system valve, the feed rate (the speed at which the stage traverses from an initiating to a terminating position), the gauge diameter of the dispensing tip, the viscosity and surface tension of the polymer solution, and the programmed drawing length. The stage feed rate affects the polymer solution's evaporation rate and capillary breakup of the filaments. The dispensing system consists of a pneumatic valve controller, a droplet-dispensing valve and a dispensing tip. Characterization of the direct write process to determine the optimum combination of factors leads to repeatedly acquiring the desired range of fiber diameters. The advantage of this robotic dispensing system is the ease of obtaining a precise range of micron/sub-micron fibers onto a desired, programmed location via automated process control. Here, the discussed self-assembled micron/sub-micron scale 3D structures have been employed to fabricate suspended structures to create micron/sub-micron fluidic devices and bioengineered scaffolds.

  14. Sub-micron particle number size distribution characteristics at two urban locations in Leicester

    Science.gov (United States)

    Hama, Sarkawt M. L.; Cordell, Rebecca L.; Kos, Gerard P. A.; Weijers, E. P.; Monks, Paul S.

    2017-09-01

    The particle number size distribution (PNSD) of atmospheric particles not only provides information about sources and atmospheric processing of particles, but also plays an important role in determining regional lung dose. Owing to the importance of PNSD in understanding particulate pollution two short-term campaigns (March-June 2014) measurements of sub-micron PNSD were conducted at two urban background locations in Leicester, UK. At the first site, Leicester Automatic Urban Rural Network (AURN), the mean number concentrations of nucleation, Aitken, accumulation modes, the total particles, equivalent black carbon (eBC) mass concentrations were 2002, 3258, 1576, 6837 # cm-3, 1.7 μg m-3, respectively, and at the second site, Brookfield (BF), were 1455, 2407, 874, 4737 # cm-3, 0.77 μg m-3, respectively. The total particle number was dominated by the nucleation and Aitken modes, with both consisting of 77%, and 81% of total number concentrations at AURN and BF sites, respectively. This behaviour could be attributed to primary emissions (traffic) of ultrafine particles and the temporal evolution of mixing layer. The size distribution at the AURN site shows bimodal distribution at 22 nm with a minor peak at 70 nm. The size distribution at BF site, however, exhibits unimodal distribution at 35 nm. This study has for the first time investigated the effect of Easter holiday on PNSD in UK. The temporal variation of PNSD demonstrated a good degree of correlation with traffic-related pollutants (NOX, and eBC at both sites). The meteorological conditions, also had an impact on the PNSD and eBC at both sites. During the measurement period, the frequency of NPF events was calculated to be 13.3%, and 22.2% at AURN and BF sites, respectively. The average value of formation and growth rates of nucleation mode particles were 1.3, and 1.17 cm-3 s-1 and 7.42, and 5.3 nm h-1 at AURN, and BF sites, respectively. It can suggested that aerosol particles in Leicester originate mainly

  15. Systematic Sub-Micron Na/Ca Banding in Orbulina universa and bilobata

    Science.gov (United States)

    Bonnin, E. A.; Zhu, Z.; Spero, H. J.; Hoenisch, B.; Russell, A. D.; Fehrenbacher, J. S.; Gagnon, A. C.

    2016-02-01

    Mg/Ca ratios in planktic foraminifera are used widely as a proxy for past sea-surface temperatures. However, over the last decade, it has become clear that these ratios are not constant throughout the shell. Instead these ratios vary systematically by several fold between day and night independent of temperature, a phenomenon that has yet to be explained mechanistically. Determining whether elements other than Mg also exhibit sub-micron banding is essential to properly interpret Me/Ca-based paleoproxies and could help constrain the mechanisms causing Me/Ca variability. Using time-of-flight secondary ion mass spectrometry (ToF-SIMS), an isotope mapping technique with a spatial resolution of roughly 200 nm, we discovered systematic Na/Ca banding in individuals of the symbiont-bearing planktic foraminifer Orbulina universa that had been cultured at constant temperature. Using stable-isotope time stamps, we show that this Na/Ca banding varies inversely with Mg/Ca, with high Na/Ca during the day and low Na/Ca at night for most individuals. Using a combination of analytical models and complementary instrumental techniques, we test whether these patterns can be explained by various ion transport processes. In addition to this Na/Ca banding pattern, there is a distinct region of both high Mg/Ca and high Na/Ca at the location of the primary organic membrane. This POM signature may be a useful way to map organic layers in foraminifera, a method we tested in bilobata, a rare morphotype of O. universa that develops a secondary sphere. Mapping Na/Ca and Mg/Ca in bilobata, we show that an additional organic layer is required during secondary sphere growth and that mineralization occurs over both spheres when this additional quasi-chamber forms. Applying ToF-SIMS and our new understanding of Na/Ca heterogeneity to bilobata is a first step towards connecting the extensive geochemical knowledge developed in O. universa to the multi-chambered species used in paleoceanography.

  16. Cathepsin K-targeted sub-micron particles for regenerative repair of vascular elastic matrix.

    Science.gov (United States)

    Jennewine, Brenton; Fox, Jonathan; Ramamurthi, Anand

    2017-04-01

    regenerative elastic matrix repair in the AAA wall. Proactive screening of high risk elderly patients now enables early detection of Abdominal Aortic Aneurysms (AAAs). Current management of small, growing AAAs is limited to passive, imaging based growth monitoring. There are also no established drug-based therapeutic alternatives to surgery for AAAs, which is unsuitable for many elderly patients, and none which can achieve restore disrupted and lost elastic matrix in the AAA wall, which is essential to achieve growth arrest or regression. We seek to test the feasibility of a regenerative therapy based on localized, one time delivery of drug-releasing Sub-Micron-sized drug delivery polymer Particles (SMPs) that are also uniquely chemically functionalized on their surface to also provide them pro-elastin-regenerative & anti-matrix degradative properties, and also conjugated with antibodies targeting cathepsin K, an elastolytic enzyme that is highly overexpressed in AAA tissues; the latter serves as a modality to enable targeted binding of the SMPs to the AAA wall following intravenous infusion, or intraoartal, catheter-based delivery. Such SMPs can potentially stimulate structural repair in the AAA wall following one time infusion to delay or prevent AAA growth to rupture. The therapy can provide a non-surgical treatment option for high risk AAA patients. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  17. Pulsed laser deposition of thin refractory metal nitride films

    Science.gov (United States)

    Fernandez, Manuel; Bereznai, M.; Caricato, A. P.; D'Anna, Emilia; Juhasz, A.; Leggieri, Gilberto; Luches, Armando; Majni, Guiseppe; Martino, Maurizio; Mengucci, Paolo; Nagy, P. M.; Nanai, Laszlo; Toth, Zsolt

    2003-11-01

    We report on the deposition of thin transition metal nitride (TMN) films by ablating Mo, Ta, V and W targets in low-pressure (1, 10 and 100 Pa) nitrogen atmosphere by KrF excimer laser pulses, and on their characterization. The targets were foils of high purity (99.8%). 3" Si(111) wafers wre used as substrates. Film characteristics (composition, crystalline structure, hardness) were studied as a function of N2 pressure, KrF laser fluence (4.5-19 J/cm2), substrate temperature (20-750°C) and target to substrate distance (30-70 mm). Rutherford backscattering spectrometery (RBS) was used to calculate thickness of the films and identification of the composition. TMN films ar formed already at low N2 ambient pressures (1 Pa) and laser fluences (6 J/cm2) on substrates at room temperature. XRD investigations show that films deposited at elevated temperatures are mostly polycrystalline. While Mo, W and Ta nitrides show respectively a γ-Mo2N, β-W2N and δ-TaN phase in almost any deposition condition, vanadium nitride shows a prevalent phase of δ-VN at N2 pressures of 1-10 Pa, while at higher pressures (100 Pa) and at relatively high laser fluences (16-19 J/cm2) the dominant phase is β-V2N. Generally the crystallinity of the films improves by increasing the substrate temperature. Well-crystallinzed films are obtained on substrates heated at 500°C. Surface morphology, microhardness and electrical resistivity of the films are discussed as a function of both the nitrogen pressure and substrate temperature.

  18. A Nordic project on high speed low power design in sub-micron CMOS technology for mobile phones

    DEFF Research Database (Denmark)

    Olesen, Ole

    This paper is a survey paper presenting the Nordic CONFRONT project and reporting some results from the group at CIE/DTU, Denmark. The objective of the project is to demonstrate the feasibility of sub-micron CMOS for the realisation of RF front-end circuits operating at frequencies in the 1.......8-2.0 GHz range. The ultimate goal is a single-chip transceiver, requiring only an external band-pass filter between the chip and the antenna. DECT has been chosen as a comparative standard to compare the new approaches developed in the work as well as to facilitate good knowledge transfer to industry. All...

  19. A simple and wide-range refractive index measuring approach by using a sub-micron grating

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chun-Wei; Wu, Chun-Che; Lin, Shih-Chieh [Department of Power Mechanical Engineering, National Tsing Hua University, 101 Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China)

    2015-04-13

    This paper presents the design and simulation results of a high-precision low-cost refractometer that demonstrates the main advantage of a wide measurement range (1 ≤ n ≤ 2). The proposed design is based on the diffractive properties of sub-micron gratings and Snell's Law. The precision and uncertainty factors of the proposed system were tested and analyzed, revealing that the proposed refractometer demonstrates a wide measurement range with sensitivity of 10{sup −4}.

  20. Optically and acoustically triggerable sub-micron phase-change contrast agents for enhanced photoacoustic and ultrasound imaging

    Directory of Open Access Journals (Sweden)

    Shengtao Lin

    2017-06-01

    Full Text Available We demonstrate a versatile phase-change sub-micron contrast agent providing three modes of contrast enhancement: 1 photoacoustic imaging contrast, 2 ultrasound contrast with optical activation, and 3 ultrasound contrast with acoustic activation. This agent, which we name ‘Cy-droplet’, has the following novel features. It comprises a highly volatile perfluorocarbon for easy versatile activation, and a near-infrared optically absorbing dye chosen to absorb light at a wavelength with good tissue penetration. It is manufactured via a ‘microbubble condensation’ method. The phase-transition of Cy-droplets can be optically triggered by pulsed-laser illumination, inducing photoacoustic signal and forming stable gas bubbles that are visible with echo-ultrasound in situ. Alternatively, Cy-droplets can be converted to microbubble contrast agents upon acoustic activation with clinical ultrasound. Potentially all modes offer extravascular contrast enhancement because of the sub-micron initial size. Such versatility of acoustic and optical ‘triggerability’ can potentially improve multi-modality imaging, molecularly targeted imaging and controlled drug release.

  1. Optically and acoustically triggerable sub-micron phase-change contrast agents for enhanced photoacoustic and ultrasound imaging.

    Science.gov (United States)

    Lin, Shengtao; Shah, Anant; Hernández-Gil, Javier; Stanziola, Antonio; Harriss, Bethany I; Matsunaga, Terry O; Long, Nicholas; Bamber, Jeffrey; Tang, Meng-Xing

    2017-06-01

    We demonstrate a versatile phase-change sub-micron contrast agent providing three modes of contrast enhancement: 1) photoacoustic imaging contrast, 2) ultrasound contrast with optical activation, and 3) ultrasound contrast with acoustic activation. This agent, which we name 'Cy-droplet', has the following novel features. It comprises a highly volatile perfluorocarbon for easy versatile activation, and a near-infrared optically absorbing dye chosen to absorb light at a wavelength with good tissue penetration. It is manufactured via a 'microbubble condensation' method. The phase-transition of Cy-droplets can be optically triggered by pulsed-laser illumination, inducing photoacoustic signal and forming stable gas bubbles that are visible with echo-ultrasound in situ . Alternatively, Cy-droplets can be converted to microbubble contrast agents upon acoustic activation with clinical ultrasound. Potentially all modes offer extravascular contrast enhancement because of the sub-micron initial size. Such versatility of acoustic and optical 'triggerability' can potentially improve multi-modality imaging, molecularly targeted imaging and controlled drug release.

  2. X-ray imaging with sub-micron resolution using large-area photon counting detectors Timepix

    Science.gov (United States)

    Dudak, J.; Karch, J.; Holcova, K.; Zemlicka, J.

    2017-12-01

    As X-ray micro-CT became a popular tool for scientific purposes a number of commercially available CT systems have emerged on the market. Micro-CT systems have, therefore, become widely accessible and the number of research laboratories using them constantly increases. However, even when CT scans with spatial resolution of several micrometers can be performed routinely, data acquisition with sub-micron precision remains a complicated task. Issues come mostly from prolongation of the scan time inevitably connected with the use of nano-focus X-ray sources. Long exposure time increases the noise level in the CT projections. Furthermore, considering the sub-micron resolution even effects like source-spot drift, rotation stage wobble or thermal expansion become significant and can negatively affect the data. The use of dark-current free photon counting detectors as X-ray cameras for such applications can limit the issue of increased image noise in the data, however the mechanical stability of the whole system still remains a problem and has to be considered. In this work we evaluate the performance of a micro-CT system equipped with nano-focus X-ray tube and a large area photon counting detector Timepix for scans with effective pixel size bellow one micrometer.

  3. A unique corundum and refractory metal-nugget bearing micrometeorite P117

    Science.gov (United States)

    Rudraswami, N. G.; Reshma, K.; Shyam Prasad, M.

    2017-01-01

    Micrometeorites provide a large range of samples sourced from a wide variety of planetary materials, thereby providing a scope for expanding the known inventory of solar system materials. Here we report the micrometeorite AAS62-34-P117 having the assemblage of corundum, hibonite, unknown Al-rich phases, FeNi metal blebs, sulfide, and phosphate embedded in Al-rich silicate composition, and Pt-group element nuggets dispersed throughout the micrometeorite. Here, we report the presence of corundum in micrometeorites as a major refractory phase with sizes greater than 10 μm. The Al-rich phases have Al2O3 50-70%, such high Al phases are not known from meteoritic components either in chondrules or refractory inclusions. In addition, the Ca content is extremely poor to relate it directly to known refractory inclusions, but is very high in Al. The presence of corundum in Al-rich phases indicates the micrometeorite to be early condensate from solar nebula that later got incorporated into Si-rich materials leading to a transformation that produced the unusual Al-rich and Ca-poor phases different from the average solar composition. The observed texture and mineralogy of the micrometeorite appears to have evolved in a nebular setting that has compositional reservoirs different from those of any known components of meteorites.

  4. Isotopic analysis of individual refractory metal nuggets using atom probe tomography

    Science.gov (United States)

    Daly, L.; Bland, P.; Schaefer, B. F.; Saxey, D. W.; Reddy, S.; Fougerouse, D.; William, R. D. A.; Forman, L. V.; Trimby, P.; La Fontaine, A.; Yang, L.; Cairney, J.; Ringer, S.

    2016-12-01

    Sub-micrometre metallic alloys of the highly siderophile elements, known as refractory metal nuggets (RMNs), can be found in primitive carbonaceous chondrites. There has been some suggestion that these grains may have a pre-solar origin, however their <1 µm size has meant that isotopic analysis of individual grains has not previously been possible. Atom probe microscopy has sufficient spatial resolution to quantify the isotopic compositions, across the entire mass range, of small sample volumes (<0.02 µm3) with high sensitivity and precision. We present analyses of four individual RMNs from the same refractory inclusion within the ALH 77307 meteorite. The results indicate that these RMNs have significant isotopic deviations from solar relative isotope abundances and therefore preserve a pre-solar isotopic signature. All RMNs exhibit large p-process enrichments in 98Ru and depletions in s-process 186Os. Two RMNs have a similar isotopic signature, suggesting formation in the same stellar environment. This similarity between two RMNs indicates that there may be a significant contribution of material to our solar system from a single source. The other two RMNs are isotopically dissimilar. Finally, three of the RMNs plot on a 187Re -187Os isochron from which we can derive a galactic age of 12.5 Ga ±1.8. To the best of our knowledge this is the first direct determination of the age of the Milky Way through physical analysis of non-solar material.

  5. Effective Third-Order Nonlinearities in Metallic Refractory Titanium Nitride Thin Films

    CERN Document Server

    Kinsey, Nathaniel; Courtwright, Devon; DeVault, Clayton; Bonner, Carl E; Gavrilenko, Vladimir I; Shalaev, Vladimir M; Hagan, David J; Van Stryland, Eric W; Boltasseva, Alexandra

    2015-01-01

    Nanophotonic devices offer an unprecedented ability to concentrate light into small volumes which can greatly increase nonlinear effects. However, traditional plasmonic materials suffer from low damage thresholds and are not compatible with standard semiconductor technology. Here we study the nonlinear optical properties in the novel refractory plasmonic material titanium nitride using the Z scan method at 1550 nm and 780 nm. We compare the extracted nonlinear parameters for TiN with previous works on noble metals and note a similarly large nonlinear optical response. However, TiN films have been shown to exhibit a damage threshold up to an order of magnitude higher than gold films of a similar thickness, while also being robust, cost-efficient, bio- and CMOS compatible. Together, these properties make TiN a promising material for metal-based nonlinear optics.

  6. A Nordic Project Project on High Speed Low Power Design in Sub-micron CMOS Technology for Mobile

    DEFF Research Database (Denmark)

    Olesen, Ole

    1997-01-01

    This paper is a survey paper presenting the Nordic CONFRONT project and reporting some results from the group at CIE/DTU, Denmark. The objective of the project is to demonstrate the feasibility of sub-micron CMOS for the realisation of RF front-end circuits operating at frequencies in the 1.......8-2.0 GHz range. The ultimate goal is a single-chip transceiver, requiring only an external band-pass filter between the chip and the antenna. DECT has been chosen as a comparative standard to compare the new approaches developed in the work as well as to facilitate good knowledge transfer to industry. All...... of including good off-chip components in the design by use of innovative, inexpensive package technology.To achieve a higher level of integration, the project will use a novel codesign approach to the design strategy. Rather than making specifications based on a purely architectural approach, the work uses...

  7. Investigation of a broadband refractory metal metamaterial absorber at terahertz frequencies.

    Science.gov (United States)

    Hu, Dan; Wang, Hongyan; Tang, Zhenjie; Zhang, Xiwei

    2016-07-01

    A broadband, polarization-independent, and wide-angle refractory metal metamaterial absorber is numerically investigated at terahertz frequencies, which consists of a periodic array of a chromium metallic loop and a chromium metallic film separated by a polyimide layer. Results show that a higher than 90% broadband absorption can be achieved for the range of frequencies from 1.00 through 2.43 THz, and the full absorption width at half-maximum can attain 110.80%, which is considerably larger than in previously reported results. Moreover, the greater than 90% broadband absorption response can still be maintained when the incidence angle increases to 45°. The physical origin of the proposed broadband absorber originates from localized surface plasmon resonances of the single metallic loop resonator. Furthermore, the designed concept also can be achieved in the visible and near-infrared region by rationally designing the dimensions of the absorber. This compact design has potential applications in stealth technology, energy harvesting, and thermal imaging.

  8. Efficacy of Self-Expandable Metallic Stent Inserted for Refractory Hemorrhage of Duodenal Cancer

    Directory of Open Access Journals (Sweden)

    Takashi Orii

    2016-05-01

    Full Text Available Because of advances in the technology of gastrointestinal endoscopy and improvements in the quality of stents, it has become routine to place a stent as palliative therapy for malignant gastrointestinal obstruction. On the other hand, stent placement for malignant gastrointestinal hemorrhage has scarcely been reported, although it may be performed for hemorrhage of the esophageal varicose vein. We recently experienced a patient with refractory hemorrhage from an unresectable duodenal cancer who underwent placement of a self-expandable metallic stent (SEMS and thereafter had no recurrence of the hemorrhage. A 46-year-old man underwent laparotomy to radically resect a cancer in the third portion of the duodenum, which invaded widely to the superior mesenteric vein and its branches and was considered unresectable. After stomach-partitioning gastrojejunostomy was performed, chemotherapy was initiated according to the regimen of chemotherapy of far advanced gastric cancer. One year and 4 months after induction of chemotherapy, gastrointestinal hemorrhage occurred. Upper gastrointestinal endoscopy revealed the hemorrhage oozing from the duodenal cancer, and endoscopic hemostasis, such as injection of hypertonic saline epinephrine and argon plasma coagulation, was unsuccessful. Twenty days after emergence of the hemorrhage, an endoscopic covered SEMS was placed with confirmation by fluoroscopy. Immediately after placement of the stent, the tarry stool stopped and the anemia ceased to progress. The recurrence of the hemorrhage has not been confirmed without migration of the stent. SEMS is an effective hemostatic procedure for malignant refractory hemorrhage.

  9. Experimental Design for Evaluation of Co-extruded Refractory Metal/Nickel Base Superalloy Joints

    Energy Technology Data Exchange (ETDEWEB)

    ME Petrichek

    2005-12-16

    Prior to the restructuring of the Prometheus Program, the NRPCT was tasked with delivering a nuclear space reactor. Potential NRPCT nuclear space reactor designs for the Prometheus Project required dissimilar materials to be in contact with each other while operating at extreme temperatures under irradiation. As a result of the high reactor core temperatures, refractory metals were the primary candidates for many of the reactor structural and cladding components. They included the tantalum-base alloys ASTAR-811C and Ta-10W, the niobium-base alloy FS-85, and the molybdenum base alloys Moly 41-47.5 Rhenium. The refractory metals were to be joined to candidate nickel base alloys such as Haynes 230, Alloy 617, or Nimonic PE 16 either within the core if the nickel-base alloys were ultimately selected to form the outer core barrel, or at a location exterior to the core if the nickel-base alloys were limited to components exterior to the core. To support the need for dissimilar metal joints in the Prometheus Project, a co-extrusion experiment was proposed. There are several potential methods for the formation of dissimilar metal joints, including explosive bonding, friction stir welding, plasma spray, inertia welding, HIP, and co-extrusion. Most of these joining methods are not viable options because they result in the immediate formation of brittle intermetallics. Upon cooling, intermetallics form in the weld fusion zone between the joined metals. Because brittle intermetallics do not form during the initial bonding process associated with HIP, co-extrusion, and explosive bonding, these three joining procedures are preferred for forming dissimilar metal joints. In reference to a Westinghouse Astronuclear Laboratory report done under a NASA sponsored program, joints that were fabricated between similar materials via explosive bonding had strengths that were directly affected by the width of the diffusion barrier. It was determined that the diffusion zone should not exceed

  10. Refractory Metal Heat Pipe Life Test - Test Plan and Standard Operating Procedures

    Science.gov (United States)

    Martin, J. J.; Reid, R. S.

    2010-01-01

    Refractory metal heat pipes developed during this project shall be subjected to various operating conditions to evaluate life-limiting corrosion factors. To accomplish this objective, various parameters shall be investigated, including the effect of temperature and mass fluence on long-term corrosion rate. The test series will begin with a performance test of one module to evaluate its performance and to establish the temperature and power settings for the remaining modules. The performance test will be followed by round-the-clock testing of 16 heat pipes. All heat pipes shall be nondestructively inspected at 6-month intervals. At longer intervals, specific modules will be destructively evaluated. Both the nondestructive and destructive evaluations shall be coordinated with Los Alamos National Laboratory. During the processing, setup, and testing of the heat pipes, standard operating procedures shall be developed. Initial procedures are listed here and, as hardware is developed, will be updated, incorporating findings and lessons learned.

  11. Vacuum Plasma Spray (VPS) Forming of Solar Thermal Propulsion Components Using Refractory Metals

    Science.gov (United States)

    Zimmerman, Frank R.; Hissam, David A.; Gerrish, Harold P.; Davis, William M.

    1999-01-01

    The Thermal Spray Laboratory at NASA's Marshall Space Flight Center has developed and demonstrated a fabrication technique using Vacuum Plasma Spray (VPS) to form structural components from a tungsten/rhenium alloy. The components were assembled into an absorber cavity for a fully-functioning, ground test unit of a solar then-nal propulsion engine. The VPS process deposits refractory metal onto a graphite mandrel of the desired shape. The mandrel acts as a male mold, forming the required contour and dimensions of the inside surface of the deposit. Tungsten and tungsten/25% rhenium were used in the development and production of several absorber cavity components. These materials were selected for their high temperature (greater than 25000 C [greater than 4530 F]) strength. Each absorber cavity comprises 3 coaxial shells with two, double-helical flow passages through which the propellant gas flows. This paper describes the processing techniques, design considerations, and process development associated with forming these engine components.

  12. High Proportions of Sub-micron Particulate Matter in Icelandic Dust Storms in 2015

    Science.gov (United States)

    Dagsson Waldhauserova, Pavla; Arnalds, Olafur; Olafsson, Haraldur; Magnusdottir, Agnes

    2017-04-01

    Iceland is extremely active dust region and desert areas of over 44,000 km2 acknowledge Iceland as the largest Arctic and European desert. Frequent dust events, up to 135 dust days annually, transport dust particles far distances towards the Arctic and Europe. Satellite MODIS pictures have revealed dust plumes exceeding 1,000 km. The annual dust deposition was calculated as 40.1 million tons yr-1. Two dust storms were measured in transverse horizontal profile about 90 km far from different dust sources in southwestern Iceland in the summer of 2015. Aerosol monitor DustTrak DRX 8533EP was used to measure PM mass concentrations corresponding to PM1, PM2.5, PM4, PM10 and the total PM15 at several places within the dust plume. Images from camera network operated by the Icelandic Road and Coastal Administration were used to estimate the visibility and spatial extent of measured dust events. A numerical simulation of surface winds was carried out with the numerical model HIRLAM with horizontal resolution of 5 km and used to calculate the total dust flux from the sources. The in situ measurements inside the dust plumes showed that aeolian dust can be very fine. The study highlights that suspended volcanic dust in Iceland causes air pollution with extremely high PM1 concentrations comparable to the polluted urban stations in Europe or Asia rather than reported dust event observations from around the world. The PM1/PM2.5 ratios are generally low during dust storms outside of Iceland, much lower than > 0.9 and PM1/PM10 ratios of 0.34-0.63 found in our study. It shows that Icelandic volcanic dust consists of higher proportion of submicron particles compared to crustal dust. The submicron particles are predicted to travel long distances. Moreover, such submicron particles pose considerable health risk because of high potential for entering the lungs. Icelandic volcanic glass has often fine pipe-vesicular structures known from asbestos and high content of heavy metals. Previous

  13. Utilizing Hilbert-Huang transform in detection some of mechanical properties of the refractory metals

    Science.gov (United States)

    Mohammed, Arshed Abdulhamed; Haris, Sallehuddin Mohamed; Nuawi, Mohd Zaki

    2016-02-01

    This study is one of the first to report on the use of Hilbert-Huang transform (HHT) to determine the modulus of elasticity of a material, which is one of the most important properties of metals. In addition, this study involves an analytical study of the process of transfer of energy, which was represented in the form of intrinsic mode functions (IMFs). Moreover, the distribution of IMFs within the time-frequency-plain was determined by testing eight test specimens. Five test specimens were refractory materials, namely, Ti, Ti6AL4V, Zr, Nb, and Ta, and the other three were non-refractory materials, namely, Al, Brass, and ST4340. The new setup was composed of Mg and involves the use of two piezoelectric transducers, which were used as the emitter and receiver. The setup was designed and implemented in this research based on Mg usage to test the metals. First, a new relationship was derived between the pressure transmission coefficient (PTC) of the transmitted wave (through the emitter-water-test specimen-Mg to the receiver) and the corresponding values of the product of the density (ρ) and the modulus of elasticity (E) for the same test specimen. Another relationship was established between the PTCs and the total energy transmitted at high frequencies. This energy indicates the summation of IMFs that have high frequencies (THIMFs), higher than 10 kHz, can determine E better than TOF for most test specimens. To verify this results, with regard to the second conclusion, a new simulation for this setup was carried out using Simulink in MATLAB. Twelve theoretical tests were done, for high acoustic impedance metals, like Hf, Mo, WNiFe and W in addition to test the same group which was tested experimentally. The results of theoretical tests supported the experimental results except for Nb. Most of the conclusions were obtained through practical results and analytical studies. The results proved that THIMFs can determine the change in the microstructure of the alloys

  14. Time-specific measurements of energy deposition from radiation fields in simulated sub-micron tissue volumes

    Energy Technology Data Exchange (ETDEWEB)

    Famiano, M.A.

    1997-07-07

    A tissue-equivalent spherical proportional counter is used with a modified amplifier system to measure specific energy deposited from a uniform radiation field for short periods of time ({approximately}1 {micro}s to seconds) in order to extrapolate to dose in sub-micron tissue volumes. The energy deposited during these time intervals is compared to biological repair processes occurring within the same intervals after the initial energy deposition. The signal is integrated over a variable collection time which is adjusted with a square-wave pulse. Charge from particle passages is collected on the anode during the period in which the integrator is triggered, and the signal decays quickly to zero after the integrator feedback switch resets; the process repeats for every triggering pulse. Measurements of energy deposited from x rays, {sup 137}Cs gamma rays, and electrons from a {sup 90}Sr/{sup 90}Y source for various time intervals are taken. Spectral characteristics as a function of charge collection time are observed and frequency plots of specific energy and collection time-interval are presented. In addition, a threshold energy flux is selected for each radiation type at which the formation of radicals (based on current measurements) in mammalian cells equals the rate at which radicals are repaired.

  15. Examination of nanosecond laser melting thresholds in refractory metals by shear wave acoustics

    Directory of Open Access Journals (Sweden)

    A. Abdullaev

    2017-07-01

    Full Text Available Nanosecond laser pulse-induced melting thresholds in refractory (Nb, Mo, Ta and W metals are measured using detected laser-generated acoustic shear waves. Obtained melting threshold values were found to be scaled with corresponding melting point temperatures of investigated materials displaying dissimilar shearing behavior. The experiments were conducted with motorized control of the incident laser pulse energies with small and uniform energy increments to reach high measurement accuracy and real-time monitoring of the epicentral acoustic waveforms from the opposite side of irradiated sample plates. Measured results were found to be in good agreement with numerical finite element model solving coupled elastodynamic and thermal conduction governing equations on structured quadrilateral mesh. Solid-melt phase transition was handled by means of apparent heat capacity method. The onset of melting was attributed to vanished shear modulus and rapid radial molten pool propagation within laser-heated metal leading to preferential generation of transverse acoustic waves from sources surrounding the molten mass resulting in the delay of shear wave transit times. Developed laser-based technique aims for applications involving remote examination of rapid melting processes of materials present in harsh environment (e.g. spent nuclear fuels with high spatio-temporal resolution.

  16. Examination of nanosecond laser melting thresholds in refractory metals by shear wave acoustics

    Science.gov (United States)

    Abdullaev, A.; Muminov, B.; Rakhymzhanov, A.; Mynbayev, N.; Utegulov, Z. N.

    2017-07-01

    Nanosecond laser pulse-induced melting thresholds in refractory (Nb, Mo, Ta and W) metals are measured using detected laser-generated acoustic shear waves. Obtained melting threshold values were found to be scaled with corresponding melting point temperatures of investigated materials displaying dissimilar shearing behavior. The experiments were conducted with motorized control of the incident laser pulse energies with small and uniform energy increments to reach high measurement accuracy and real-time monitoring of the epicentral acoustic waveforms from the opposite side of irradiated sample plates. Measured results were found to be in good agreement with numerical finite element model solving coupled elastodynamic and thermal conduction governing equations on structured quadrilateral mesh. Solid-melt phase transition was handled by means of apparent heat capacity method. The onset of melting was attributed to vanished shear modulus and rapid radial molten pool propagation within laser-heated metal leading to preferential generation of transverse acoustic waves from sources surrounding the molten mass resulting in the delay of shear wave transit times. Developed laser-based technique aims for applications involving remote examination of rapid melting processes of materials present in harsh environment (e.g. spent nuclear fuels) with high spatio-temporal resolution.

  17. The plasma device for the high-heat plasma testing of refractory metals and inventing of new highly porous materials

    Science.gov (United States)

    Budaev, V. P.; Fedorovich, S. D.; Martynenko, Yu V.; Lukashevsky, M. V.; Gubkin, M. K.; Lazukin, A. V.; Karpov, A. V.; Shestakov, E. A.

    2017-11-01

    A unique plasma device has been constructed at the NRU “MPEI” for the study of plasma-surface interaction and the high-heat plasma testing of refractory metals, such as tungsten, molybdenum, steel and other plasma facing materials used in fusion reactor including the ITER. This plasma device is a multi-cusp linear stationary plasma confinement system. It has power-saving characteristics as well as compactness due to the employment of the 8-pole multicusp magnetic field configuration instead of a strong axial magnetic field. Experiments are planned to develop a novel technology for highly porous surface structure of the refractory metal with a pore size and nanofibers of 50 nanometers including tungsten “fuzz”.

  18. Cost Estimate for Molybdenum and Tantalum Refractory Metal Alloy Flow Circuit Concepts

    Science.gov (United States)

    Hickman, Robert R.; Martin, James J.; Schmidt, George R.; Godfroy, Thomas J.; Bryhan, A.J.

    2010-01-01

    The Early Flight Fission-Test Facilities (EFF-TF) team at NASA Marshall Space Flight Center (MSFC) has been tasked by the Naval Reactors Prime Contract Team (NRPCT) to provide a cost and delivery rough order of magnitude estimate for a refractory metal-based lithium (Li) flow circuit. The design is based on the stainless steel Li flow circuit that is currently being assembled for an NRPCT task underway at the EFF-TF. While geometrically the flow circuit is not representative of a final flight prototype, knowledge has been gained to quantify (time and cost) the materials, manufacturing, fabrication, assembly, and operations to produce a testable configuration. This Technical Memorandum (TM) also identifies the following key issues that need to be addressed by the fabrication process: Alloy selection and forming, cost and availability, welding, bending, machining, assembly, and instrumentation. Several candidate materials were identified by NRPCT including molybdenum (Mo) alloy (Mo-47.5 %Re), tantalum (Ta) alloys (T-111, ASTAR-811C), and niobium (Nb) alloy (Nb-1 %Zr). This TM is focused only on the Mo and Ta alloys, since they are of higher concern to the ongoing effort. The initial estimate to complete a Mo-47%Re system ready for testing is =$9,000k over a period of 30 mo. The initial estimate to complete a T-111 or ASTAR-811C system ready for testing is =$12,000k over a period of 36 mo.

  19. Influence of particle bombardment on microstructure and internal stresses of refractory metal suicides on silicon

    Science.gov (United States)

    Hardtke, Ch.; Schilling, W.; Ullmaier, H.

    1991-07-01

    First results on microstructural changes and stress relaxation in thin refractory metal suicide films (TaSi 2 and MoSi 2) caused by particle bombardment are reported. The polycrystalline films had initial tensile stresses of some 10 9 Pa. Exposed to irradiation with Ge ions of 400 keV, both suicides showed a similar stress relaxation behaviour as a function of dose. During room-temperature implantation the initial tensile stress rapidly decreased and turned into compressive stress. Continuous irradiation partly relaxed the compressive stress and resulted in a saturation value of some -10 8 Pa. With increasing implantation temperature, the buildup of compressive stress gradually vanished, leaving only the initial decrease of tensile stress which finally approached zero. Based on microstructural investigations (TEM and X-ray diffraction) it is proposed to explain this behaviour by the combined action of two processes: relaxation of tensile stress by a volume increase due to irradiation-induced amorphization, and Frenkel defect production and relaxation of compressive stress by irradiation-induced densification of amorphous regions and/or Frenkel defect elimination.

  20. Direct Metal Deposition of Refractory High Entropy Alloy MoNbTaW

    Science.gov (United States)

    Dobbelstein, Henrik; Thiele, Magnus; Gurevich, Evgeny L.; George, Easo P.; Ostendorf, Andreas

    Alloying of refractory high entropy alloys (HEAs) such as MoNbTaW is usually done by vacuum arc melting (VAM) or powder metallurgy (PM) due to the high melting points of the elements. Machining to produce the final shape of parts is often needed after the PM process. Casting processes, which are often used for aerospace components (turbine blades, vanes), are not possible. Direct metal deposition (DMD) is an additive manufacturing technique used for the refurbishment of superalloy components, but generating these components from the bottom up is also of current research interest. MoNbTaW possesses high yield strength at high temperatures and could be an alternative to state-of-the-art materials. In this study, DMD of an equimolar mixture of elemental powders was performed with a pulsed Nd:YAG laser. Single wall structures were built, deposition strategies developed and the microstructure of MoNbTaW was analyzed by back scattered electrons (BSE) and energy dispersive X-ray (EDX) spectroscopy in a scanning electron microscope. DMD enables the generation of composition gradients by using dynamic powder mixing instead of pre-alloyed powders. However, the simultaneous handling of several elemental or pre-alloyed powders brings new challenges to the deposition process. The influence of thermal properties, melting point and vapor pressure on the deposition process and chemical composition will be discussed.

  1. Fabrication of a high-aspect-ratio sub-micron tool using a cathode coated with stretched-out insulating layers

    Science.gov (United States)

    Zeng, Yongbin; Wang, Yufeng; Qu, Ningsong; Zhu, Di

    2013-09-01

    This paper describes a method for preparing a high-aspect-ratio sub-micron tool using a cathode coated with stretched-out insulating layers and a straight reciprocating motion applied at the anode via the liquid membrane electrochemical machining (ECM). Simulation results indicate that the application of a cathode coated with stretched-out insulating layers is beneficial for the localization of ECM. Moreover, a mathematical model was derived to estimate the final average diameter of the fabricated tools. Experiments were conducted to verify the versatility and feasibility of the proposed method and its mathematical model. It was observed that the calculated and the experimental results are in good agreement with each other. A sub-micron tool with an average diameter 140.8 nm and an aspect ratio up to 50 was fabricated using the proposed method.

  2. SiO2/ZnO Composite Hollow Sub-Micron Fibers: Fabrication from Facile Single Capillary Electrospinning and Their Photoluminescence Properties.

    Science.gov (United States)

    Song, Guanying; Li, Zhenjiang; Li, Kaihua; Zhang, Lina; Meng, Alan

    2017-02-24

    In this work, SiO2/ZnO composite hollow sub-micron fibers were fabricated by a facile single capillary electrospinning technique followed by calcination, using tetraethyl orthosilicate (TEOS), polyvinylpyrrolidone (PVP) and ZnO nanoparticles as raw materials. The characterization results of the scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) spectra indicated that the asprepared composite hollow fibers consisted of amorphous SiO2 and hexagonal wurtzite ZnO. The products revealed uniform tubular structure with outer diameters of 400-500 nm and wall thickness of 50-60 nm. The gases generated and the directional escaped mechanism was proposed to illustrate the formation of SiO2/ZnO composite hollow sub-micron fibers. Furthermore, a broad blue emission band was observed in the photoluminescence (PL) of SiO2/ZnO composite hollow sub-micron fibers, exhibiting great potential applications as blue light-emitting candidate materials.

  3. SiO2/ZnO Composite Hollow Sub-Micron Fibers: Fabrication from Facile Single Capillary Electrospinning and Their Photoluminescence Properties

    Directory of Open Access Journals (Sweden)

    Guanying Song

    2017-02-01

    Full Text Available In this work, SiO2/ZnO composite hollow sub-micron fibers were fabricated by a facile single capillary electrospinning technique followed by calcination, using tetraethyl orthosilicate (TEOS, polyvinylpyrrolidone (PVP and ZnO nanoparticles as raw materials. The characterization results of the scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffraction (XRD and Fourier transform infrared spectroscopy (FT-IR spectra indicated that the asprepared composite hollow fibers consisted of amorphous SiO2 and hexagonal wurtzite ZnO. The products revealed uniform tubular structure with outer diameters of 400–500 nm and wall thickness of 50–60 nm. The gases generated and the directional escaped mechanism was proposed to illustrate the formation of SiO2/ZnO composite hollow sub-micron fibers. Furthermore, a broad blue emission band was observed in the photoluminescence (PL of SiO2/ZnO composite hollow sub-micron fibers, exhibiting great potential applications as blue light-emitting candidate materials.

  4. Crystallography of refractory metal nuggets in carbonaceous chondrites: A transmission Kikuchi diffraction approach

    Science.gov (United States)

    Daly, Luke; Bland, Phil A.; Dyl, Kathryn A.; Forman, Lucy V.; Saxey, David W.; Reddy, Steven M.; Fougerouse, Denis; Rickard, William D. A.; Trimby, Patrick W.; Moody, Steve; Yang, Limei; Liu, Hongwei; Ringer, Simon P.; Saunders, Martin; Piazolo, Sandra

    2017-11-01

    Transmission Kikuchi diffraction (TKD) is a relatively new technique that is currently being developed for geological sample analysis. This technique utilises the transmission capabilities of a scanning electron microscope (SEM) to rapidly and accurately map the crystallographic and geochemical features of an electron transparent sample. TKD uses a similar methodology to traditional electron backscatter diffraction (EBSD), but is capable of achieving a much higher spatial resolution (5-10 nm) (Trimby, 2012; Trimby et al., 2014). Here we apply TKD to refractory metal nuggets (RMNs) which are micrometre to sub-micrometre metal alloys composed of highly siderophile elements (HSEs) found in primitive carbonaceous chondrite meteorites. TKD allows us to analyse RMNs in situ, enabling the characterisation of nanometre-scale variations in chemistry and crystallography, whilst preserving their spatial and crystallographic context. This provides a complete representation of each RMN, permitting detailed interpretation of their formation history. We present TKD analysis of five transmission electron microscopy (TEM) lamellae containing RMNs coupled with EBSD and TEM analyses. These analyses revealed textures and relationships not previously observed in RMNs. These textures indicate some RMNs experienced annealing, forming twins. Some RMNs also acted as nucleation centres, and formed immiscible metal-silicate fluids. In fact, each RMN analysed in this study had different crystallographic textures. These RMNs also had heterogeneous compositions, even between RMNs contained within the same inclusion, host phase and even separated by only a few nanometres. Some RMNs are also affected by secondary processes at low temperature causing exsolution of molybdenite. However, most RMNs had crystallographic textures indicating that the RMN formed prior to their host inclusion. TKD analyses reveal most RMNs have been affected by processing in the protoplanetary disk. Despite this

  5. Trends and sources of ozone and sub-micron aerosols at the Mt. Bachelor Observatory during 2004-2015

    Science.gov (United States)

    Zhang, L.; Jaffe, D. A.; Hee, J.

    2016-12-01

    Tropospheric ozone (O3) and airborne particles have significant impacts on human health and the environment. The Mt. Bachelor Observatory (MBO, 2.8 km a.s.l.) in Central Oregon, USA, now has one of the longest continuous free tropospheric records of O3, CO and aerosols in North America. In this study, we report on sources and trends of O3 and sub-micron aerosol scattering at MBO for 2004-2015. For O3, the seasonal cycle shows a bimodal pattern with peaks in April and July, while aerosol scattering (σsp) is lognormally distributed with a very high average in August and a smaller maximum in May. Mean O3 concentrations show a positive and significant trend in all seasons except winter, with an increase of approximately 0.6 ppb/year. This trend appears to be driven by Asian pollution in spring and regional wildfires in summer. For aerosol scattering, we see a significant increase only in summer, driven by recent increases in wildfire activity in the western US. Monthly criteria for isolating free troposphere (FT) and boundary layer (BL) air masses at MBO were obtained based on comparison of MBO water vapor (WV) distributions to those of Salem (SLE) and Medford (MFR), Oregon at equivalent pressure level. In all seasons, FT O3 is, on average, higher than BL O3, but the seasonal patterns are rather similar. For σsp the mean in summer is significantly higher than the FT, indicating the importance of regional wildfire smoke. We have identified four types of air masses that impact O3, CO and aerosols: Asian long range transport (ALRT), regional wildfires, regional industrial pollution, and upper troposphere and lower stratosphere (UTLS) intrusions. Over the 12 years of observations, we have identified 204 individual plume events based on the criteria of 8 consecutive polluted hours with elevated σsp, O3 or CO. Multi-pollutant correlations and backward trajectories were used to differentiate background source categories. A series of enhancement ratios (ERs) including

  6. Trends and sources of ozone and sub-micron aerosols at the Mt. Bachelor Observatory (MBO) during 2004-2015

    Science.gov (United States)

    Zhang, Lei; Jaffe, Daniel A.

    2017-09-01

    In this paper, we report the climatology of tropospheric ozone (O3) and sub-micron aerosol scattering at the Mt. Bachelor Observatory (MBO, 2.8 km asl) in central Oregon, USA, during 2004-2015. The seasonal cycle for O3 showed a bimodal pattern with peaks in April and July, while aerosol scattering (σsp) was lognormally distributed with a very high peak in August and a smaller peak in May. The mean O3 concentrations showed positive and significant trends in all seasons except winter, with a slope of 0.6-0.8 ppbv yr-1. Monthly criteria for isolating free tropospheric (FT) and boundary layer influenced (BLI) air masses at MBO were obtained based on comparison of MBO water vapor (WV) distributions to those of Salem (SLE) and Medford (MFR), Oregon, at equivalent pressure level. In all seasons, FT O3 was, on average, higher than BLI O3, but the seasonal patterns were rather similar. For σsp the FT mean in spring was higher, but the BLI mean in summer was significantly higher, indicating the importance of regional wildfire smoke. To better understand the causes for the seasonal and interannual trends at MBO, we identified four major categories of air masses that impact O3, carbon monoxide (CO) and aerosols: upper troposphere and lower stratosphere (UTLS) O3 intrusion, Asian long-range transport (ALRT), Arctic air pollution (AAP) and plumes from the Pacific Northwest region (PNW). ALRT and PNW plumes can be further divided into wildfires (WF), industrial pollution (IP) and mineral dust (MD). Over the 12 years of observations, 177 individual plume events have been identified. Enhancement ratios (ERs) and Ångström exponents (AEs) of aerosols were calculated for all events. The lowest slope of Δσsp/ΔO3 is a unique feature of UTLS events. PNW-WF events have the highest averages for Δσsp/ΔCO, Δσsp/ΔO3 and Δσsp/ΔNOy compared to other events. These ERs decrease during long-range transport due to the shorter residence time of aerosols compared to the other

  7. Thermodynamic properties of heavy ion heated refractory metals; Thermodynamische Eigenschaften von schwerionengeheizten hochschmelzenden Metallen

    Energy Technology Data Exchange (ETDEWEB)

    Hug, Alexander

    2011-05-04

    Knowledge of basic physical properties of matter in high-energy-density (HED) states such as the equation-of-state (EOS) is of fundamental importance for various branches of basic and applied physics. However, such matter under extreme conditions of temperature and pressure - also called ''warm dense matter'' (WDM) - can only be generated in dynamic experiments employing the most powerful drivers. At the high temperature experimental area HHT of the GSI Helmholtzzentrum fuer Schwerionenforschung (Darmstadt, Germany), intense beams of energetic heavy ions are used for this purpose. The aim of this work is to study thermophysical properties of refractory metals in hot solid and liquid states by precise temperature measurements. In order to identify the melting plateau and to limit the maximum target temperature to the region of interest, relatively long (one microsecond) bunches of uranium and xenon ions have been used to heat initially solid samples. The intense ion beams were focused on a millimetre spot at the target in order to achieve uniform conditions. The temperature on the target surface was determined by analysing thermal radiation emitted from a 0.03 mm{sup 2} area at five different wavelengths. In order to obtain the physical temperature, one has to measure not only the thermal radiation but also the emissivity, ε(T,λ) of the target surface which is not known ab initio. For this purpose, a set-up for direct target reflection measurement was designed and embedded into the fast multichannel pyrometer system. The reflection signal provides the necessary information about modifications of the target surface properties during the interaction with the ion beam. Beside the pyrometric and reflection measurement set-ups, various hardware and software components of the data acquisition system for the heavy-ion beam driven experiments were substantially enhanced. The emissivity was also obtained by identifying the melting plateau and using the

  8. Hydrothermal Synthesis Au-Bi2Te3 Nanocomposite Thermoelectric Film with a Hierarchical Sub-Micron Antireflection Quasi-Periodic Structure

    Directory of Open Access Journals (Sweden)

    Junlong Tian

    2015-06-01

    Full Text Available In this work, Au-Bi2Te3 nanocomposite thermoelectric film with a hierarchical sub-micron antireflection quasi-periodic structure was synthesized via a low-temperature chemical route using Troides helena (Linnaeus forewing (T_FW as the biomimetic template. This method combines chemosynthesis with biomimetic techniques, without the requirement of expensive equipment and energy intensive processes. The microstructure and the morphology of the Au-Bi2Te3 nanocomposite thermoelectric film was analyzed by X-ray diffraction (XRD, field-emission scanning-electron microscopy (FESEM, and transmission electron microscopy (TEM. Coupled the plasmon resonances of the Au nanoparticles with the hierarchical sub-micron antireflection quasi-periodic structure, the Au-Bi2Te3 nanocomposite thermoelectric film possesses an effective infrared absorption and infrared photothermal conversion performance. Based on the finite difference time domain method and the Joule effect, the heat generation and the heat source density distribution of the Au-Bi2Te3 nanocomposite thermoelectric film were studied. The heterogeneity of heat source density distribution of the Au-Bi2Te3 nanocomposite thermoelectric film opens up a novel promising technique for generating thermoelectric power under illumination.

  9. Sub-micron resolution surface plasmon resonance imaging enabled by nanohole arrays with surrounding Bragg mirrors for enhanced sensitivity and isolation.

    Science.gov (United States)

    Lindquist, Nathan C; Lesuffleur, Antoine; Im, Hyungsoon; Oh, Sang-Hyun

    2009-02-07

    We present nanohole arrays in thin gold films as sub-micron resolution surface plasmon resonance (SPR) imaging pixels in a microarray format. With SPR imaging, the resolution is not limited by diffraction, but by the propagation of surface plasmon waves to adjacent sensing areas, or nanohole arrays, causing unwanted interference. For ultimate scalability, several issues need to be addressed, including: (1) as several nanohole arrays are brought close to each other, surface plasmon interference introduces large sources of error; and (2) as the size of the nanohole array is reduced, i.e. fewer holes, detection sensitivity suffers. To address these scalability issues, we surround each biosensing pixel (a 3-by-3 nanohole array) with plasmonic Bragg mirrors, blocking interference between adjacent SPR sensing pixels for high-density packing, while maintaining the sensitivity of a 50 x larger footprint pixel (a 16-by-16 nanohole array). We measure real-time, label-free streptavidin-biotin binding kinetics with a microarray of 600 sub-micron biosensing pixels at a packing density of more than 10(7) per cm(2).

  10. Experimental investigation of refractory metals in the premelting region during fast heating

    Science.gov (United States)

    Senchenko, V. N.; Belikov, R. S.; Popov, V. S.

    2015-11-01

    This work demonstrates experimental possibility of investigation of high refractory materials around its melting point, particularly in premelting region with high accuracy. In this article authors describe the developed experimental setup based on rapid resistive self-heating of a sample by a large current pulse generated by a capacitor discharge circuit that allow fast pulse interruption by temperature feedback signal. The sample temperature was measured with a two-channel microsecond radiation pyrometer. Preliminary experiments were conducted on tantalum and molybdenum at heating speed of 108 K/s. The method allows investigating thermophysical properties of refractory conductive materials such as melting temperature, melting heat, specific resistivity, specific enthalpy and specific heat capacity in solid and liquid phase, especially in premelting area.

  11. Diffusion Couple Alloying of Refractory Metals in Austenitic and Ferritic/Martensitic Steels

    Science.gov (United States)

    2012-03-01

    23]:   ) Dt4 /(x 2 e Dt4 N t,xC    (2) C(x,t) = concentration (wt%) of refractory element at a given position x from the “film” (taken from...as shown in Figure 21. This slope is then defined via Equation (2) as Dt4 1 m  (3) which can be rearranged to solve for

  12. Refractory-Slag-Metal-Inclusion Multiphase Reactions Modeling Using Computational Thermodynamics: Kinetic Model for Prediction of Inclusion Evolution in Molten Steel

    Science.gov (United States)

    Shin, Jae Hong; Chung, Yongsug; Park, Joo Hyun

    2017-02-01

    The refractory-slag-metal-inclusion multiphase reaction model was developed by integrating the refractory-slag, slag-metal, and metal-inclusion elementary reactions in order to predict the evolution of inclusions during the secondary refining processes. The mass transfer coefficient in the metal and slag phase, and the mass transfer coefficient of MgO in the slag were employed in the present multiphase reactions modeling. The "Effective Equilibrium Reaction Zone (EERZ) Model" was basically employed. In this model, the reaction zone volume per unit step for metal and slag phase, which is dependent on the `effective reaction zone depth' in each phase, should be defined. Thus, we evaluated the effective reaction zone depth from the mass transfer coefficient in metal and slag phase at 1873 K (1600 °C) for the desulfurization reaction which was measured in the present study. Because the dissolution rate of MgO from the refractory to slag phase is one of the key factors affecting the slag composition, the mass transfer coefficient of MgO in the ladle slag was also experimentally determined. The calculated results for the variation of the composition of slag and molten steel as a function of reaction time were in good agreement with the experimental results. The MgAl2O4 spinel inclusion was observed at the early to middle stage of the reaction, whereas the liquid oxide inclusion was mainly observed at the final stage of the refining reaction. The content of CaO sharply increased, and the SiO2 content increased mildly with the increasing reaction time, while the content of Al2O3 in the inclusion drastically decreased. Even though there is slight difference between the calculated and measured results, the refractory-slag-metal multiphase reaction model constructed in the present study exhibited a good predictability of the inclusion evolution during ladle refining process.

  13. Compatibility of refractory metals and beryllium with molten Pb-17Li

    Energy Technology Data Exchange (ETDEWEB)

    Feuerstein, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany); Graebner, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany); Oschinski, J. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany); Horn, S. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany)

    1996-10-01

    The compatibility of V, Nb, Ta, Mo, W and Re with static eutectic mixture Pb-17Li was investigated experimentally. All these metals are very stable in the eutectic up to 600 C. Dissolution rates as well as solubilities are low. Below 600 C, a chemical reaction zone caused by initiation of an intergranular corrosion was observed. There was a strong isothermal mass transfer to the crucible wall. Diffusion coefficients for vanadium were calculated. They are in the expected range. The behaviour of beryllium is included in this paper for comparison. Diffusion coefficients were determined. In spite of low dissolution rates a strong intergranular corrosion causes destruction of this metal. (orig.).

  14. Source apportionment of fine PM and sub-micron particle number concentrations at a regional background site in the western Mediterranean: a 2.5 year study

    Directory of Open Access Journals (Sweden)

    M. Cusack

    2013-05-01

    Full Text Available The chemical composition and sources of ambient fine particulate matter (PM1 over a period of 2.5 years for a regional background site in the western Mediterranean are presented in this work. Furthermore, sub-micron particle number concentrations and the sources of these particles are also presented. The mean PM1 concentration for the measurement period was 8.9 μg m−3, with organic matter (OM and sulphate comprising most of the mass (3.2 and 1.5 μg m−3 respectively. Six sources were identified in PM1 by Positive Matrix Factorisation (PMF: secondary organic aerosol, secondary nitrate, industrial, traffic + biomass burning, fuel oil combustion and secondary sulphate. Typically anthropogenic sources displayed elevated concentrations during the week with reductions at weekends. Nitrate levels were elevated in winter and negligible in summer, whereas secondary sulphate levels underwent a contrasting seasonal evolution with highest concentrations in summer, similar to the fuel oil combustion source. The SOA source was influenced by episodes of sustained pollution as a result of anticyclonic conditions occurring during winter, giving rise to thermal inversions and the accumulation of pollutants in the mixing layer. Increased levels in summer were owing to higher biogenic emissions and regional recirculation of air masses. The industrial source decreased in August due to decreased emissions during the vacation period. Increases in the traffic + biomass burning source were recorded in January, April and October, which were attributed to the occurrence of the aforementioned pollution episodes and local biomass burning emission sources, which include agriculture and domestic heating systems. Average particle number concentrations (N9-825 nm from 5/11/2010 to 01/06/2011 and from 15/10/2011 to 18/12/2011 reached 3097 cm−3. Five emission sources of particle of sub-micron particles were determined by Principal Component Analysis (PCA; industrial

  15. An Investigation of the Irradiation Swelling Mechanisms in Refractory Metals at High Temperatures.

    Science.gov (United States)

    1985-02-01

    Kratos 1.2 MV high voltage transmission electron microscope, a National Electrostatics 2-MV Tandem type universal ion accelerator , and a Texas Nuclear... Electrostatics Type 2 UDHS 2.0-MV Tandem accelerator is equipped with one internal and two external negative ion sources for helium and metal ions...respectively. The specifications are given in Table VI. Table VI. Specifications of Tandem Accelerator Terminal Voltage 180-2000 kV Charging System 1 pelletron

  16. Refractory metal superalloys: Design of yttrium aluminum garnet passivating niobium alloys

    Science.gov (United States)

    Bryan, David

    A systems-based approach, integrating computational modeling with experimental techniques to approach engineering problems in a time and cost efficient manner, was employed to design a Nb-based refractory superalloy for use at 1300°C. Ashby-type selection criteria for both thermodynamic and kinetic parameters were employed to identify a suitable protective oxide for Nb alloys. Yttrium aluminum garnet (YAG) was selected as the most promising candidate for its excellent combination of desirable properties. The alloy microstructural concept was based upon the gamma - gamma' nickel-based superalloys in which the multifunctional gamma' phase serves as both a creep strengthening dispersion and a source of reactive elements for oxide passivation. Candidate ternary Pd-Y-Al and Pt-Y-Al compounds were fabricated and characterized by XRD and DTA. Of the intermetallics studied, only PtYAl had a high enough melting point (1580°C) for use in an alloy operating at 1300°C. The alloy matrix design was based upon Wahl's extension of Wagner's criterion for protective oxidation, requiring a reduction of the product N ODO/DAl by 5 orders of magnitude relative to binary Nb-Al. A thermodynamic and kinetic analysis identified elements with large oxygen affinities as the most beneficial for reducing the magnitude of the quantity NOD O. Construction of a combined thermodynamic and mobility database identified increased Al solubility as the best approach for increasing D Al. Utilizing the thermodynamic and mobility databases, obtained from a combination of model alloys, oxidation experiments, and first principles calculations, theoretical designs predicted the large changes in solubility and transport parameters were achievable. Several prototype alloys were then fabricated and evaluated via oxidation tests at both 1300°C and 1100°C. YAG formation was demonstrated as part of multicomponent oxide scales in the alloys that exhibited the greatest reduction in oxidation rates. The oxidation

  17. Image-Guided Ultrasound Characterization of Volatile Sub-Micron Phase-Shift Droplets in the 20-40 MHz Frequency Range.

    Science.gov (United States)

    Sheeran, Paul S; Daghighi, Yasaman; Yoo, Kimoon; Williams, Ross; Cherin, Emmanuel; Foster, F Stuart; Burns, Peter N

    2016-03-01

    Phase-shift perfluorocarbon droplets are designed to convert from the liquid to the gas state by the external application of acoustic or optical energy. Although droplet vaporization has been investigated extensively at ultrasonic frequencies between 1 and 10 MHz, few studies have characterized performance at the higher frequencies commonly used in small animal imaging. In this study, we use standard B-mode imaging sequences on a pre-clinical ultrasound platform to both image and activate sub-micron decafluorobutane droplet populations in vitro and in vivo at center frequencies in the range of 20-40 MHz. Results show that droplets remain stable against vaporization at low imaging pressures but are vaporized at peak negative pressures near 3.5 MPa at the three frequencies tested. This study also found that a small number of size outliers present in the distribution can greatly influence droplet performance. Removal of these outliers results in a more accurate assessment of the vaporization threshold and produces free-flowing microbubbles upon vaporization in the mouse kidney. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  18. A Fast, Versatile Nanoprobe for Complex Materials: The Sub-micron Resolution X-ray Spectroscopy Beamline at NSLS-II (491st Brookhaven Lecture)

    Energy Technology Data Exchange (ETDEWEB)

    Thieme, Juergen [BNL Photon Sciences Directorate

    2014-02-06

    Time is money and for scientists who need to collect data at research facilities like Brookhaven Lab’s National Synchrotron Light Source (NSLS), “beamtime” can be a precious commodity. While scanning a complex material with a specific technique and standard equipment today would take days to complete, researchers preparing to use brighter x-rays and the new sub-micron-resolution x-ray spectroscopy (SRX) beamline at the National Synchrotron Light Source II (NSLS-II) could scan the same sample in greater detail with just a few hours of beamtime. Talk about savings and new opportunities for researchers! Users will rely on these tools for locating trace elements in contaminated soils, developing processes for nanoparticles to deliver medical treatments, and much more. Dr. Thieme explains benefits for next-generation research with spectroscopy and more intense x-rays at NSLS-II. He discusses the instrumentation, features, and uses for the new SRX beamline, highlighting its speed, adjustability, and versatility for probing samples ranging in size from millimeters down to the nanoscale. He will talk about complementary beamlines being developed for additional capabilities at NSLS-II as well.

  19. Synthesis and self-assembly of dumbbell shaped ZnO sub-micron structures using low temperature chemical bath deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Borade, P. [National Centre for Nanoscience and Nanotechnology, University of Mumbai, Kalina Campus, Santacruz (E), Mumbai 400098 (India); Joshi, K.U. [Anton-Paar India Pvt. Ltd., Thane (W), 400607 (India); Gokarna, A.; Lerondel, G. [Laboratoire de Nanotechnologie et D' Instrumentation Optique, Institut Charles Delaunay, CNRS UMR 6281, Université de Technologie de Troyes, 12 Rue Marie Curie, BP 2060, 10010 Troyes (France); Walke, P. [National Centre for Nanoscience and Nanotechnology, University of Mumbai, Kalina Campus, Santacruz (E), Mumbai 400098 (India); Late, D. [National Chemical Laboratory (NCL), Pune 400027 (India); Jejurikar, S.M., E-mail: jejusuhas@gmail.com [National Centre for Nanoscience and Nanotechnology, University of Mumbai, Kalina Campus, Santacruz (E), Mumbai 400098 (India)

    2016-02-01

    We report well dispersed horizontal growth of ZnO sub-micron structures using simplest technique ever known i.e. chemical bath deposition (CBD). A set of samples were prepared under two different cases A) dumbbell shaped ZnO grown in CBD bath and B) tubular ZnO structures evolved from dumbbell shaped structures by dissolution mechanism. Single phase wurtzite ZnO formation is confirmed using X-ray diffraction (XRD) technique in both cases. From the morphological investigations performed using scanning electron microscopy (SEM), sample prepared under case A indicate formation of hex bit tool (HBT) shaped ZnO crystals, which observed to self-organize to form dumbbell structures. Further these microstructures are then converted into tubular structures as a fragment of post CBD process. The possible mechanism responsible for the self-assembly of HBT units to form dumbbell structures is discussed. Observed free excitonic peak located at 370 nm in photoluminescence (PL) spectra recorded at 18 K indicate that the micro/nanostructures synthesized using CBD are of high optical quality. - Highlights: • Controlled growth of Dumbbell shaped ZnO using Chemical Bath Deposition (CBD). • Growth mechanism of dumbbell shaped ZnO by self-assembling was discussed. • Quick Transformation of ZnO dumbbell structures in to tubular structures by dissolution. • Sharp UV Emission at 370 nm from both dumbbell and tubular structures.

  20. Scaling down the two-dimensional electron gas spin resonance (ESR) phenomena in GaAs/AlGaAs heterostructures to sub-micron samples

    Science.gov (United States)

    Bandaru, Prabhakar; Yablonovitch, Eli; Jiang, Hong-Wen

    2002-03-01

    Electron Spin Resonance (ESR) has been proposed as a technique for achieving single electron and subsequently single spin control, important for the emerging fields of spintronics and quantum computing. In this paper, we report on ESR in the quantum Hall regime, of sub-micron structures containing a few hundred electrons. These phenomena are contrasted with ESR phenomena in structures containing 10^7 - 10^9 electrons, which have been performed so far (Reference 1). There are several novel features observed in the ESR of small structures, such as a very large decrease of resistance and shift in the quantum Hall minima to lower magnetic fields after the resonance. These imply a reduction in the number of electrons and could result from the greater influence of the surface and impurity potential fluctuations intrinsic to a small sample. The ESR peak intensity is hypothesized to result from the transfer of electrons from the localized states to the extended states. References: 1.H.W.Jiang and E. Yablonovitch, Phys. Rev.B., 64, R041307, (2001) 2.M.Dobers, K.v. Klitzing and G. Weimann,Phys. Rev. B, 38, 5453, (1988).

  1. Sub-micron and nanoscale feature depth modulates alignment of stromal fibroblasts and corneal epithelial cells in serum-rich and serum-free media.

    Science.gov (United States)

    Fraser, Sarah A; Ting, Yuk-Hong; Mallon, Kelly S; Wendt, Amy E; Murphy, Christopher J; Nealey, Paul F

    2008-09-01

    Topographic features are generally accepted as being capable of modulating cell alignment. Of particular interest is the potential that topographic feature geometry induces cell alignment indirectly through impacting adsorbed proteins from the cell culture medium on the surface of the substrate. However, it has also been reported that micron-scale feature depth significantly impacts the level of alignment of cellular populations on topography, despite being orders of magnitude larger than the average adsorbed protein layer (nm). In order to better determine the impact of biomimetic length scale topography and adsorbed protein interaction on cellular morphology we have systematically investigated the effect of combinations of sub-micron to nanoscale feature depth and lateral pitch on corneal epithelial cell alignment. In addition we have used the unique properties of a serum-free media alternative in direct comparison to serum-rich medium to investigate the role of culture medium protein composition on cellular alignment to topographically patterned surfaces. Our observation that increasing groove depth elicited larger populations of corneal epithelial cells to align regardless of culture medium composition and of cell orientation with respect to the topography, suggests that these cells can sense changes in topographic feature depths independent of adsorbed proteins localized along ridge edges and tops. However, our data also suggests a strong combinatory effect of topography with culture medium composition, and also a cell type dependency in determining the level of cell elongation and alignment to nanoscale topographic features.

  2. Sub-micron and nanoscale feature depth modulates alignment of stromal fibroblasts and corneal epithelial cells in serum-rich and serum-free media

    Science.gov (United States)

    Fraser, Sarah A.; Ting, Yuk-Hong; Mallon, Kelly S.; Wendt, Amy E.; Murphy, Christopher J.; Nealey, Paul F.

    2011-01-01

    Topographic features are generally accepted as being capable of modulating cell alignment. Of particular interest is the potential that topographic feature geometry induces cell alignment indirectly through impacting adsorbed proteins from the cell culture medium on the surface of the substrate. However, it has also been reported that micron-scale feature depth significantly impacts the level of alignment of cellular populations on topography, despite being orders of magnitude larger than the average adsorbed protein layer (nm). In order to better determine the impact of biomimetic length scale topography and adsorbed protein interaction on cellular morphology we have systematically investigated the effect of combinations of sub-micron to nanoscale feature depth and lateral pitch on corneal epithelial cell alignment. In addition we have used the unique properties of a serum-free media alternative in direct comparison to serum-rich medium to investigate the role of culture medium protein composition on cellular alignment to topographically patterned surfaces. Our observation that increasing groove depth elicited larger populations of corneal epithelial cells to align regardless of culture medium composition and of cell orientation with respect to the topography, suggests that these cells can sense changes in topographic feature depths independent of adsorbed proteins localized along ridge edges and tops. However, our data also suggests a strong combinatory effect of topography with culture medium composition, and also a cell type dependency in determining the level of cell elongation and alignment to nanoscale topographic features. PMID:18041718

  3. The heterogeneous reaction of hydroxyl radicals with sub-micron squalane particles: a model system for understanding the oxidative aging of ambient aerosols

    Science.gov (United States)

    Smith, J. D.; Kroll, J. H.; Cappa, C. D.; Che, D. L.; Liu, C. L.; Ahmed, M.; Leone, S. R.; Worsnop, D. R.; Wilson, K. R.

    2009-05-01

    The heterogeneous reaction of OH radicals with sub-micron squalane particles, in the presence of O2, is used as a model system to explore the fundamental chemical mechanisms that control the oxidative aging of organic aerosols in the atmosphere. Detailed kinetic measurements combined with elemental mass spectrometric analysis reveal that the reaction proceeds sequentially by adding an average of one oxygenated functional group per reactive loss of squalane. The reactive uptake coefficient of OH with squalane particles is determined to be 0.3±0.07 at an average OH concentration of ~1×1010 molecules cm-3. Based on a comparison between the measured particle mass and model predictions it appears that significant volatilization of a reduced organic particle would be extremely slow in the real atmosphere. However, as the aerosols become more oxygenated, volatilization becomes a significant loss channel for organic material in the particle-phase. Together these results provide a chemical framework in which to understand how heterogeneous chemistry transforms the physiochemical properties of particle-phase organic matter in the troposphere.

  4. The heterogeneous reaction of hydroxyl radicals with sub-micron squalane particles: a model system for understanding the oxidative aging of ambient aerosols

    Directory of Open Access Journals (Sweden)

    J. D. Smith

    2009-05-01

    Full Text Available The heterogeneous reaction of OH radicals with sub-micron squalane particles, in the presence of O2, is used as a model system to explore the fundamental chemical mechanisms that control the oxidative aging of organic aerosols in the atmosphere. Detailed kinetic measurements combined with elemental mass spectrometric analysis reveal that the reaction proceeds sequentially by adding an average of one oxygenated functional group per reactive loss of squalane. The reactive uptake coefficient of OH with squalane particles is determined to be 0.3±0.07 at an average OH concentration of ~1×1010 molecules cm−3. Based on a comparison between the measured particle mass and model predictions it appears that significant volatilization of a reduced organic particle would be extremely slow in the real atmosphere. However, as the aerosols become more oxygenated, volatilization becomes a significant loss channel for organic material in the particle-phase. Together these results provide a chemical framework in which to understand how heterogeneous chemistry transforms the physiochemical properties of particle-phase organic matter in the troposphere.

  5. Sub-micron Polymer–Zeolitic Imidazolate Framework Layered Hybrids via Controlled Chemical Transformation of Naked ZnO Nanocrystal Films

    Energy Technology Data Exchange (ETDEWEB)

    Meckler, Stephen M.; Li, Changyi; Queen, Wendy L.; Williams, Teresa E.; Long, Jeffrey R.; Buonsanti, Raffaella; Milliron, Delia J.; Helms, Brett A.

    2015-11-24

    Here we show that sub-micron coatings of zeolitic imidazolate frameworks (ZIFs) and even ZIF–ZIF bilayers can be grown directly on polymers of intrinsic microporosity from zinc oxide (ZnO) nanocrystal precursor films, yielding a new class of all-microporous layered hybrids. The ZnO-to-ZIF chemical transformation proceeded in less than 30 min under microwave conditions using a solution of the imidazole ligand in N,N-dimethylformamide (DMF), water, or mixtures thereof. By varying the ratio of DMF to water, it was possible to control the morphology of the ZIF-on-polymer from isolated crystallites to continuous films. Grazing incidence X-ray diffraction was used to confirm the presence of crystalline ZIF in the thin films, and X-ray absorption spectroscopy was used to quantify film purity, revealing films with little to no residual ZnO. The role solvent plays in the transformation mechanism is discussed in light of these findings, which suggest the ZnO nanocrystals may be necessary to localize heterogeneous nucleation of the ZIF to the polymer surface.

  6. Sub-micron Polymer–Zeolitic Imidazolate Framework Layered Hybrids via Controlled Chemical Transformation of Naked ZnO Nanocrystal Films

    Energy Technology Data Exchange (ETDEWEB)

    Meckler, Stephen M.; Li, Changyi; Queen, Wendy L. [Department; Williams, Teresa E.; Long, Jeffrey R.; Buonsanti, Raffaella; Milliron, Delia J. [McKetta; Helms, Brett A.

    2015-11-02

    Here we show that sub-micron coatings of zeolitic imidazolate frameworks (ZIFs) and even ZIF–ZIF bilayers can be grown directly on polymers of intrinsic microporosity from zinc oxide (ZnO) nanocrystal precursor films, yielding a new class of all-microporous layered hybrids. The ZnO-to-ZIF chemical transformation proceeded in less than 30 min under microwave conditions using a solution of the imidazole ligand in N,N-dimethylformamide (DMF), water, or mixtures thereof. By varying the ratio of DMF to water, it was possible to control the morphology of the ZIF-on-polymer from isolated crystallites to continuous films. Grazing incidence X-ray diffraction was used to confirm the presence of crystalline ZIF in the thin films, and X-ray absorption spectroscopy was used to quantify film purity, revealing films with little to no residual ZnO. The role solvent plays in the transformation mechanism is discussed in light of these findings, which suggest the ZnO nanocrystals may be necessary to localize heterogeneous nucleation of the ZIF to the polymer surface.

  7. Comprehensive recovery of gold and base-metal sulfide minerals from a low-grade refractory ore

    Science.gov (United States)

    Li, Wen-juan; Liu, Shuang; Song, Yong-sheng; Wen, Jian-kang; Zhou, Gui-ying; Chen, Yong

    2016-12-01

    The comprehensive recovery of small amounts of valuable minerals such as gold and base-metal sulfide minerals from a low-grade refractory ore was investigated. The following treatment strategy was applied to a sample of this ore: gold flotation-gold concentrate leaching-lead and zinc flotation from the gold concentrate leaching residue. Closed-circuit trials of gold flotation yielded a gold concentrate that assayed at 40.23 g·t-1 Au with a recovery of 86.25%. The gold concentrate leaching rate was 98.76%. Two variants of lead-zinc flotation from the residue—preferential flotation of lead and zinc and bulk flotation of lead and zinc—were tested using the middling processing method. Foam from the reflotation was returned to the lead rougher flotation or lead-zinc bulk flotation, whereas middlings from reflotation were discarded. Sulfur concentrate was a byproduct. The combined strategy of flotation, leaching, and flotation is recommended for the treatment of this kind of ore.

  8. Closeout Report for the Refractory Metal Accelerated Heat Pipe Life Test Activity

    Science.gov (United States)

    Martin, J.; Reid, R.; Stewart, E.; Hickman, R.; Mireles, O.

    2013-01-01

    With the selection of a gas-cooled reactor, this heat pipe accelerated life test activity was closed out and its resources redirected. The scope of this project was to establish the long-term aging effects on Mo-44.5%Re sodium heat pipes when subjected to space reactor temperature and mass fluences. To date, investigators have demonstrated heat pipe life tests of alkali metal systems up to .50,000 hours. Unfortunately, resources have not been available to examine the effect of temperature, mass fluence, or impurity level on corrosion or to conduct post-test forensic examination of heat pipes. The key objective of this effort was to establish a cost/time effective method to systematically test alkali metal heat pipes with both practical and theoretical benefits. During execution of the project, a heat pipe design was established, a majority of the laboratory test equipment systems specified, and operating and test procedures developed. Procurements for the heat pipe units and all major test components were underway at the time the stop work order was issued. An extremely important outcome was the successful fabrication of an annular wick from Mo-5%Re screen (the single, most difficult component to manufacture) using a hot isostatic pressing technique. This Technical Publication (TP) includes specifics regarding the heat pipe calorimeter water-cooling system, vendor design for the radio frequency heating system, possible alternative calorimeter designs, and progress on the vanadium equilibration technique. The methods provided in this TP and preceding project documentation would serve as a good starting point to rapidly implement an accelerated life test. Relevant test data can become available within months, not years, and destructive examination of the first life test heat pipe might begin within 6 months of test initiation. Final conclusions could be drawn in less than a quarter of the mission duration for a long-lived, fission-powered, deep space probe.

  9. The flow stress of high-purity refractory body-centred cubic metals and its modification by atomic defects

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, A. [Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany). Inst. fuer Physik

    1995-11-01

    The strong temperature and strain-rate dependence of the flow stress of high-purity refractory body-centred cubic metals has been shown to be an intrinsic property and is ascribed to a high Peierls barrier of a{sub o} left angle 111 right angle /2 screw dislocations. These barriers are overcome by the formation of kink pairs on the screw dislocations. The paper reports on recent, complete flow-stress data on ultra-high purity Mo crystals obtained by two different experimental techniques. The results are in accord with earlier work of Brunner and Diehl on {alpha}-Fe, who showed that below the so-called knee temperature, T{sub K}, three regimes in the temperature variation of the flow-stress should be distinguished. Two of them are fully accounted for by the same glide mechanism, namely elementary glide steps on {l_brace}211{r_brace} planes. The upper bend separating these two regimes in an inherent feature of the theory of kink-pair formation and does not indicate a change in the glide mechanism. There is strong evidence that the lower bend, separating the range of {l_brace}211{r_brace} elementary glide steps from the low-temperature flow-stress regime, is due to a change in the glide mechanism. It is argued that at the lower bend the screw-dislocation cores undergo a ``first-order phase transition`` from a low-temperature configuration that allows glide of a given screw dislocation on any of its three {l_brace}110{r_brace} glide planes to a high-temperature configuration that can glide only on one definite {l_brace}211{r_brace} plane. Between T{sub K} and the lower-bend temperature, T, bcc metals may show the unique phenomena of alloy and irradiation softening. With regard to the latter phenomenon, Brunner and Diehl distinguish between ``primary`` and ``secondary`` softening. It is shown that alloy softening and the ``secondary irradiation softening`` of bcc metals may be explained by an ``overheating`` of the phase transition in the dislocation core. (orig./WL).

  10. Hygroscopicity of Chemically Aged, sub-micron Squalane Particles: On the Role of Size and Composition towards the Hygroscopicity Parameter κ

    Science.gov (United States)

    Harmon, C. W.; Smith, J. D.; Che, D. L.; Leone, S. R.; Wilson, K. R.

    2010-12-01

    Measurements presented herein explore cloud condensation nuclei (CCN) activity of sub-micron squalane particles chemically aged by hydroxyl radicals as a function of size and OH exposure. As squalane particles are exposed to OH radicals, size-selected 100, 150, and 200 nm particles monotically decrease in size with increasing OH exposure. Concurrently, their CCN derived hygroscopicity parameter values, κ, increase with OH exposure until saturating at 0.165 in the 100 nm data set, 0.140 in the 150 nm data set, and reach a maximum value of 0.075 in the 200 nm data set at the highest level of OH exposure. The critical super-saturation relative humidity (RH) at which CCN activity is achieved decreases initially with increasing OH exposure and then increases with OH exposure, most notably for the 100 nm data set and weakly with the 150 nm data set. Chemically aged squalane particles from the 200 nm data set show a monotonic decrease in critical super-saturation RH with all values of increasing OH exposure between 0.1-2.5 × 10^13 s molec./cc. The measured O:C ratios of 160 nm chemically aged squalane particles, which were reported previously, are compared to κ values by the CCN derived relationship reported in literature: κ = 0.30*O:C and reasonable agreement is attained in the size-selected 150 nm data set. These values are also compared with the hygroscopic growth factor derived relationship in literature: κ = 0.49*(O:C -0.25) and reasonable agreement is attained at O:C > 0.35.

  11. 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

  12. On the sub-micron aerosol size distribution in a coastal-rural site at El Arenosillo Station (SW – Spain

    Directory of Open Access Journals (Sweden)

    M. Sorribas

    2011-11-01

    Full Text Available This study focuses on the analysis of the sub-micron aerosol characteristics at El Arenosillo Station, a rural and coastal environment in South-western Spain between 1 August 2004 and 31 July 2006 (594 days. The mean total concentration (NT was 8660 cm−3 and the mean concentrations in the nucleation (NNUC, Aitken (NAIT and accumulation (NACC particle size ranges were 2830 cm−3, 4110 cm−3 and 1720 cm−3, respectively. Median size distribution was characterised by a single-modal fit, with a geometric diameter, median number concentration and geometric standard deviation of 60 nm, 5390 cm−3 and 2.31, respectively. Characterisation of primary emissions, secondary particle formation, changes to meteorology and long-term transport has been necessary to understand the seasonal and annual variability of the total and modal particle concentration. Number concentrations exhibited a diurnal pattern with maximum concentrations around noon. This was governed by the concentrations of the nucleation and Aitken modes during the warm seasons and only by the nucleation mode during the cold seasons. Similar monthly mean total concentrations were observed throughout the year due to a clear inverse variation between the monthly mean NNUC and NACC. It was related to the impact of desert dust and continental air masses on the monthly mean particle levels. These air masses were associated with high values of NACC which suppressed the new particle formation (decreasing NNUC. Each day was classified according to a land breeze flow or a synoptic pattern influence. The median size distribution for desert dust and continental aerosol was dominated by the Aitken and accumulation modes, and marine air masses were dominated by the nucleation and Aitken modes. Particles

  13. -C Refractories

    Science.gov (United States)

    Xu, Yibiao; Sang, Shaobai; Li, Yawei; Ren, Bo; Zhao, Lei; Li, Yuanbing; Li, Shujing

    2014-06-01

    Al2O3-C refractories were first fabricated in a coke bed at 1673 K (1400 °C) using tabular corundum, reactive alumina, carbon black, silicon, and microsilica as the starting materials and phenol resin as the binder. Then the alkali attack resistance of those materials was conducted in the powder mixture of carbon black and potassium carbonate (1:1 wt pct) in a graphite crucible at 1273 K (1000 °C) for 10 hours. The correlation between pore size, permeability of Al2O3-C refractories, and their alkali (K2CO3) attack was investigated by means of mercury intrusion porosimetry, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results showed that the pore structure of Al2O3-C refractories was controlled by the addition of silicon, ultrafine reactive alumina, and microsilica to in-situ form SiC whiskers and mullite in the preparation process. The mean pore size of Al2O3-C refractories was strongly associated with permeability. With the decrease of the mean pore size, the permeability of the Al2O3-C refractories reduced constantly. The alkali attack test also verified that the Al2O3-C refractories with lower permeability had better alkali corrosion resistance, because the penetration of K vapor into the materials could be restricted effectively. The corrosion mechanism of Al2O3-C refractories supposes that (1) K2CO3 was reduced to K vapor and penetrated into the specimen through the open pores and (2) K vapor reacted with SiC, SiO2, and alumina to form KAlSi2O6 and KAlSiO4, which is in agreement with the thermodynamic prediction.

  14. Highly Refractory Porous Ceramics,

    Science.gov (United States)

    1979-03-14

    also highly refractory porous materials based on co- rundum and magnesite were released in a limited amount.(1,6). The technology of manufacturing...there is an effect of slags and 4and other molten substances ( glasses , metals, etc.), under conditions where there is an effect of gas flows at high...slags, metal, glass , ashes, etc. (Table 53). Table 53 Ta6.,Hua 53 A Upeue~mbuas TenepaTypa npNveneas aA$MocANAEnaTNX n AunacoMux aerolecubM

  15. Role of carboxylate ion and metal oxidation state on the morphology ...

    Indian Academy of Sciences (India)

    Sub-micron rods and spheres of cobalt succinate sesquihydrate and iron succinate trihydrate/pentahydrate respectively have been synthesized by the reverse micellar route. These precursors are an excellent source for the synthesis of metal and metal oxide nanoparticles. Cubes of (edge length ∼ 150 nm) Fe3O4 and ...

  16. Chromia refractory brick with carbon treatment

    Science.gov (United States)

    Bennett, James P.; Kwong, Kyei-Sing

    2017-03-21

    The disclosure provides a refractory brick system comprising a chromia refractory brick for operation in the slagging environment of an air-cooled gasifier. The chromia refractory brick comprises a ceramically-bonded porous chromia refractory having a porosity greater than 9% and having carbon deposits residing within the pores. The brick may be further comprised of Al.sub.2O.sub.3. The air-cooled gasifier generates a liquefied slag in contact with the refractory brick and generally operates at temperatures between 1250.degree. C. and 1575.degree. C. and pressures between 300 psi to 1000 psi, with oxygen partial pressures generally between 10.sup.-4 and 10.sup.-10 atm. The refractory brick performs without substantial chromium carbide or chromium metal formation in the low oxygen partial pressure environment. The inclusion of carbon without chromium carbide formation provides for significant mitigation of slag penetration and significantly reduced refractory wear.

  17. HIGHLY REFRACTORY CRUCIBLES OF STABILIZED ZIRCONIA FOR INDUCTION MELTING OF THE PLATINUM GROUP METALS, FABRICATED BY VIBROCASTING

    Directory of Open Access Journals (Sweden)

    V. V. Primachenko

    2012-01-01

    Full Text Available As the result of the studies at PJSC « UKRNIIO them. A.S.Berezhnogo» the technology and commercial production of crucibles from stabilized zirconia for the smelting of platinum group metals are develop

  18. Temporary metallic stent placement in the treatment of refractory benign esophageal strictures: results and factors associated with outcome in 55 patients

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hyoung; Kim, Kyung Rae; Shin, Ji Hoon; Lim, Jin-Oh [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea); Song, Ho-Young [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea)]|[University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology, Seoul (Korea); Choi, Eugene K. [Weill Medical College of Cornell University, New York, NY (United States)

    2009-02-15

    The purpose of this study was to evaluate the effectiveness of temporary metallic stenting in 55 patients with treatment-resistant benign esophageal strictures and to identify factors associated with clinical outcomes. Under fluoroscopic guidance, covered retrievable stents were placed in 55 patients with benign esophageal strictures and were removed with retrieval hook 1 week to 6 months after placement. Stent placement was successful in all patients, and the mean dysphagia score was reduced from 2.8 to 1.3 (p<0.001). The most common complications were tissue hyperproliferation (31%), severe pain (24%), and stent migration (25%). During follow-up (mean: 38 months), recurrence of the stricture necessitating balloon dilation was seen in 38 (69%) of 55 patients. Maintained patency rates after temporary stenting at 1, 3, and 6 months and 1, 2, and 4 years were 58%, 43%, 38%, 33%, 26%, and 21%, respectively. In multivariate analysis, length (p=0.003) of the stricture was the only significant factor associated with maintained patency after temporary stenting. In conclusion, temporary metallic stenting for refractory benign esophageal strictures may be effective during the period of stent placement, but is disadvantaged by the high recurrence rates after stent removal, particularly in patients with a long length of stricture (>7cm). (orig.)

  19. Transglutaminase-induced or citric acid-mediated cross-linking of whey proteins to tune the characteristics of subsequently desolvated sub-micron and nano-scaled particles.

    Science.gov (United States)

    Bagheri, Leila; Yarmand, Mohammadsaeed; Madadlou, Ashkan; Mousavi, Mohammad E

    2014-01-01

    Whey proteins were inter-connected either by the enzyme transglutaminase or citric acid and then desolvated with ethanol to generate particles. Both samples comprised of sub-micron (>300 nm) and nano-scaled (~100 nm) particles based on the hydrodynamic size measurements. Enzyme-induced cross-linking of proteins yielded more monodisperse particles and decreased the mean size of the major (nano-scaled) fraction of particles. Scanning electron microscopy images revealed a spherical morphology for all samples with mean sizes of particles from enzymatically cross-linked proteins. The mediating role of citric acid in bridging the proteins was confirmed by Fourier transform infrared spectroscopy. Differential scanning calorimetry indicated that pre-heating of protein solution before cross-linking and desolvation denatured the proteins entirely. In vitro degradation of whey protein particles in a simulated gastric fluid demonstrated that cross-linking of whey proteins before desolvation stage enhanced significantly the digestion stability of particles.

  20. Environmental and energy gains from using molten magnesium–sodium–potassium chlorides for electro-metallisation of refractory metal oxides

    Directory of Open Access Journals (Sweden)

    Wei Li

    2015-12-01

    Full Text Available The molten eutectic mixture of magnesium, sodium and potassium chlorides (MgCl2–NaCl–KCl has inappreciable solubility for oxide ions, and can help disengage a carbon anode from the oxide ions generated at a metal oxide cathode, and effectively avoid carbon dioxide formation. This “disengaging strategy” was successfully demonstrated in electro-reduction of solid oxides of zirconium and tantalum. It has led to significantly higher current efficiency (93%, and lower energy consumption (1.4 kW h kg−1 in electrolysis of tantalum oxide to tantalum metal compared to the conventional electrolysis in molten calcium chloride (e.g. 78% and 2.4 kW h/kg-Ta.

  1. Present situation of refractories in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Bittencourt, P. (Magnesita S.A., (Brazil))

    1992-11-10

    This paper outlines the present situation of refractories in Brazil, particularly the use of refractories in the steel industry which is one of the major industries in this country. Brazil is the 8th largest steel producer in the world, and about 64% of all the production is exported. Because of increasing competitions in the world market, high-level production techniques are required, and active improvements of refractories are also being carried out. The specific consumption of refractories in 1 ton of steel has gradually decreased to produce high-quality refractories. In Brazil, 95% of all demand except for special items such as submerged nozzles and blast furnace carbon blocks can be provided domestically. It is characteristic that raw materials for refractories, such as magnesite, bauxite, and graphite can also be self-supporting. Compositions and physical properties of typical refractories used for various purposes in iron and steel manufactures including blast furnaces, torpedo cars, BOF converters, electric are furnaces, and electric arc ladles are described, and the direction toward their conversion into new materials is shown. Moreover, the trends of refractories for the cement industry and for nonferrous metals such as aluminum are introduced. 6 figs., 15 tabs.

  2. REFRACTORY DIE FOR EXTRUDING URANIUM

    Science.gov (United States)

    Creutz, E.C.

    1959-08-11

    A die is presented for the extrusion of metals, said die being formed of a refractory complex oxide having the composition M/sub n/O/sub m/R/sub x/O/sub y/ where M is magnesium, zinc, manganese, or iron, R is aluminum, chromic chromium, ferric iron, or manganic manganese, and m, n, x, and y are whole numbers. Specific examples are spinel, magnesium aluminate, magnetite, magnesioferrite, chromite, and franklinite.

  3. Impact of smoking on guided tissue regeneration using a biocomposite poly (lactic-co-glycolic) acid/sub-micron size hydroxyapatite with a rubber dam as an alternative barrier.

    Science.gov (United States)

    Stramazzotti, D; Coiana, C; Zizzi, A; Spazzafumo, L; Sauro, S; D'Angelo, A B; Rubini, C; Aspriello, S D

    2015-03-01

    The purpose of our study was to critically evaluate the results obtained from a guided tissue regeneration technique after 12 months using a bocomposite poly (lactic-co-glycolic) acid/sub-micron size hydroxyapatite (PLGA/HA) with a rubber dam as a barrier in smoking and non-smoking patients. We selected 36 patients (18 current smokers and 18 non-smokers) diagnosed with chronic advanced periodontitis with a periodontal site (probing depth [PD] >5) amenable to regenerative surgery. Twelve months after surgery, the periodontal parameters were found to have statistically improved, when non-smokers were compared with smokers, in: PD reduction (6.3 ± 2.1 mm vs. 3.6 ± 1.9 mm); CAL gain (4.4 ± 1.1 vs. 2.8 ± 2.2 mm); recession (1.8 ± 1.4 mm vs. 0.8 ± 0.9 mm); and hard tissue fill (4.7 ± 0.8 mm vs. 2.8 ± 2.1 mm). Furthermore, since we found PD baseline differences between groups, smoking seemed not to influence the outcomes achieved (CAL gain and ΔREC) 12 months post surgery with respect to PD baseline. The use of PLGA/HA with a rubber dam significantly improved the periodontal parameters in both smoking and non-smoking subjects. This improvement was nevertheless lower in smokers than the non-smokers, confirming the negative impact of smoking on periodontal regeneration. © The Author(s) 2015.

  4. Carbon Based Refractories

    National Research Council Canada - National Science Library

    EWAIS, Emad Mohamed M

    2004-01-01

    .... They are classified into two groups; carbon/bricks/blocks and carbon containing materials. Carbon containing materials are further classified into carbon containing basic refractories and non-basic refractories...

  5. Modification of Inclusions in Molten Steel by Mg-Ca Transfer from Top Slag: Experimental Confirmation of the `Refractory-Slag-Metal-Inclusion (ReSMI)' Multiphase Reaction Model

    Science.gov (United States)

    Shin, Jae Hong; Park, Joo Hyun

    2017-12-01

    High-temperature experiments and Refractory-Slag-Metal-Inclusion (ReSMI) multiphase reaction simulations were carried out to determine the effect of the ladle slag composition on the formation behavior of non-metallic inclusions in molten steel. Immediately after the slag-metal reaction, magnesium migrated to the molten steel and a MgAl2O4 spinel inclusion was formed due to a reaction between magnesium and alumina inclusions. However, the spinel inclusion changed entirely into a liquid oxide inclusion via the transfer of calcium from slag to metal in the final stage of the reaction. Calcium transfer from slag to metal was more enhanced for lower SiO2 content in the slag. Consequently, the spinel inclusion was modified to form a liquid CaO-Al2O3-MgO-SiO2 inclusion, which is harmless under steelmaking conditions. The modification reaction was more efficient as the SiO2 content in the slag decreases.

  6. Sub-micron indent induced plastic deformation in copper and irradiated steel; Deformation plastique induite par l'essai d'indentation submicronique, dans le cuivre et l'acier 316L irradie

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Ch

    1999-07-01

    In this work we aim to study the indent induced plastic deformation. For this purpose, we have developed a new approach, whereby the indentation curves provides the mechanical behaviour, while the deformation mechanisms are observed thanks to Transmission Electron Microscopy (TEM). In order to better understand how an indent induced dislocation microstructure forms, numerical modeling of the indentation process at the scale of discrete dislocations has been worked out as well. Validation of this modeling has been performed through direct comparison of the computed microstructures with TEM micrographs of actual indents in pure Cu (001]. Irradiation induced modifications of mechanical behaviour of ion irradiated 316L have been investigated, thanks to the mentioned approach. An important hardening effect was reported from indentation data (about 50%), on helium irradiated 316L steel. TEM observations of the damage zone clearly show that this behaviour is associated with the presence of He bubbles. TEM observations of the indent induced plastic zone also showed that the extent of the plastic zone is strongly correlated with hardness, that is to say: harder materials gets a smaller plastic zone. These results thus clearly established that the selected procedure can reveal any irradiation induced hardening in sub-micron thick ion irradiated layers. The behaviour of krypton irradiated 316L steel is somewhat more puzzling. In one hand indeed, a strong correlation between the defect cluster size and densities on the irradiation temperature is observed in the 350 deg. C - 600 deg. C range, thanks to TEM observations of the damage zone. On the other hand, irradiation induced hardening reported from indentation data is relatively small (about 10%) and shows no dependence upon the irradiation temperature (within the mentioned range). In addition, it has been shown that the reported hardening vanishes following appropriate post-irradiation annealing, although most of the TEM

  7. 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.; hide

    2009-01-01

    Ceramics can be defmed as a material consisting of hard brittle properties produced from inorganic and nonmetallic minerals made by firing at high temperatures. These materials are compounds between metallic and nonmetallic elements and are either totally ionic, or predominately ionic but having some covalent character. This definition allows for a large range of materials, not all applicable to refractory applications. As this report is focused on potential ceramic materials for high temperature, aggressive exposure applications, the ceramics reviewed as part of this report will focus on refractory ceramics specifically designed and used for these applications. Ceramic materials consist of a wide variety of products. Callister (2000) 1 characterized ceramic materials into six classifications: glasses, clay products, refractories, cements, abrasives, and advanced ceramics. Figure 1 shows this classification system. This review will focus mainly on refractory ceramics and cements as in general, the other classifications are neither applicable nor economical for use in large structures such as the flame trench. Although much work has been done in advanced ceramics over the past decade or so, these materials are likely cost prohibitive and would have to be fabricated off-site, transported to the NASA facilities, and installed, which make these even less feasible. Although the authors reviewed the literature on advanced ceramic refractories 2 center dot 3 center dot 4 center dot 5 center dot 6 center dot 7 center dot 8 center dot 9 center dot 10 center dot 11 center dot 12 after the review it was concluded that these materials should not be ' the focus of this report. A review is in progress on materials and systems for prefabricated refractory ceramic panels, but this review is focusing more on typical refractory materials for prefabricated systems, which could make the system more economically feasible. Refractory ceramics are used for a wide variety of applications

  8. Development of improved refractories

    Energy Technology Data Exchange (ETDEWEB)

    Wereszczak, A.A.; Ferber, M.K.; Liu, K.C. [Oak Ridge National Lab., TN (United States); Moore, R.E. [Univ. of Missouri, Rolla, MO (United States)

    1997-04-01

    The goal of the proposed project is to provide expertise and facilities for the high temperature mechanical properties characterization of refractory materials which are of interest to the US DOE`s Office of Industrial Technologies Advanced Industrial Materials Project. Initially the project would establish dedicated refractory testing facilities which would be capable of generating representative engineering creep and high temperature modulus of elasticity (MOE) data to a temperature of 3300{degrees}F (1815{degrees}C) in ambient air. The generated engineering creep and MOE data would serve R&D requirements of refractories-manufacturers and its glass-manufacturer end-users and designers. The relevance of this effort to the refractory and glass-making industries would be ensured by coordinating the research activities through a membership with Alfred University`s Center for Glass Research (CGR) Satellite Center at the University of Missouri-Rolla (UMR), an NSF Center. Valid engineering creep and high temperature MOE data currently do not exist for almost all commercial refractories. Refractory end-users such as glass-manufacturers require such data for efficient and economical design of their various glass-melting furnace superstructures (e.g., furnace crowns). Refractories in glass production furnaces may be subjected to extreme temperatures as high as 3200{degrees}F (1760{degrees}C). With the simultaneous imposition of mechanical and thermal stresses, creep deformation of the refractory material will assuredly occur as a consequence. Designers must ensure that the structural integrity is maintained, so these high temperature deformations must be considered for successful glass furnace superstructure design. These criteria can only be satisfied with the utilization of representative engineering creep and high temperature MOE data for the refractory materials that are chosen for the design of the refractory superstructures.

  9. HIGH TEMPERATURE REFRACTORY COATING FOR GRAPHITE MOLDS

    Science.gov (United States)

    Stoddard, S.D.

    1958-10-21

    An improved foundry mold coating for use with graphite molds used in the casting of uranium is presented. The refractory mold coating serves to keep the molten uranium from contact with graphite of the mold and thus prevents carbon pickup by the molten metal. The refractory coating is made by dry mixing certain specific amounts of aluminum oxide, bentonite, Tennessee ball clay, and a soluble silicate salt. Water is then added to the mixture and the suspension thus formed is applied by spraying onto the mold.

  10. 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...

  11. Management of refractory epilepsy.

    Science.gov (United States)

    Muñana, Karen R

    2013-05-01

    The term refractory epilepsy is utilized in veterinary medicine to describe a condition in which an animal with epilepsy fails to attain satisfactory seizure control or suffers intolerable side effects despite appropriate therapy with conventional antiepileptic drugs. Refractory epilepsy is an important problem in small animal practice as it occurs in approximately one-third of dogs with epilepsy. Consequently, there is much interest in identifying ways to more effectively treat this population of animals. More than a dozen new antiepileptic drugs have been approved for humans over the last 2 decades, and several of these drugs, including gabapentin, zonisamide, levetiracetam, and pregabalin, have been evaluated for the treatment of refractory seizures in veterinary patients. Nonmedical methods to treat poorly controlled epilepsy are also being explored. The 2 alternative forms of therapy that have shown the most promise in humans with epilepsy are electrical stimulation of the brain and dietary modification, both of which have also been evaluated in dogs. This overview summarizes the available data on pharmacologic as well as nonmedical treatment options for dogs and cats with refractory epilepsy. Although many forms of therapy are currently being utilized in clinical practice, our knowledge of the safety and efficacy of these treatments is limited. Additional randomized controlled trials are needed to better evaluate these novel therapies for refractory epilepsy in dogs and cats. © 2013 Elsevier Inc. All rights reserved.

  12. Refractory gastroesophageal reflux disease

    Directory of Open Access Journals (Sweden)

    Joaquim Prado P. Moraes-Filho

    2012-12-01

    Full Text Available CONTEXT: Gastroesophageal reflux disease (GERD is a condition which develops when the reflux of stomach contents causes troublesome symptoms and/or complications. Its pathophysiology, diagnosis and treatment have frequently been analyzed but it is interesting to review some aspects of the GERD refractory patients to the proton pump inhibitors treatment. The treatment encompasses behavioral measures and pharmacological therapy. The majority of the patients respond well to proton pump inhibitors treatment but 20%-42% of them may not do so well. Patients who are unresponsible to 4-8 weeks' treatment with proton pump inhibitors (omeprazole, pantoprazole, rabeprazole, lansoprazole, esomeprazole, pantoprazole-Mg might have so-called refractory GERD. RESULTS: In some cases the patients are not real refractory because either they do not have GERD or the disease was not correctly treated, but the term refractory is still employed. Although debatable, the Brazilian GERD Consensus based upon evidences recommends as first step in the diagnosis, the upper digestive endoscopy to exclude the diagnosis of peptic ulcer and cancer and in some cases identify the presence of esophageal mucosa erosions. CONCLUSIONS: The main causes of the so-called refractory GERD are: (1 functional heartburn; (2 low levels of adherence to proton pump inhibitors treatment; (3 inadequate proton pump inhibitors dosage; (4 wrong diagnosis; (5 co-morbidities and pill-induced esophagitis; (6 genotypic differences; (7 nonacid gastroesophageal reflux; (8 autoimmune skin diseases; (9 eosinophilic esophagitis.

  13. Compatibility of refractory materials for nuclear reactor poison control systems

    Science.gov (United States)

    Sinclair, J. H.

    1974-01-01

    Metal-clad poison rods have been considered for the control system of an advanced space power reactor concept studied at the NASA Lewis Research Center. Such control rods may be required to operate at temperatures of about 140O C. Selected poison materials (including boron carbide and the diborides of zirconium, hafnium, and tantalum) were subjected to 1000-hour screening tests in contact with candidate refractory metal cladding materials (including tungsten and alloys of tantalum, niobium, and molybdenum) to assess the compatibility of these materials combinations at the temperatures of interest. Zirconium and hafnium diborides were compatible with refractory metals at 1400 C, but boron carbide and tantalum diboride reacted with the refractory metals at this temperature. Zirconium diboride also showed promise as a reaction barrier between boron carbide and tungsten.

  14. 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.

  15. Plasmonic properties of refractory titanium nitride

    Science.gov (United States)

    Catellani, Alessandra; Calzolari, Arrigo

    2017-03-01

    The development of plasmonic and metamaterial devices requires the research of high-performance materials alternative to standard noble metals. Renewed as a refractory stable compound for durable coatings, titanium nitride has recently been proposed as an efficient plasmonic material. Here, by using a first-principles approach, we investigate the plasmon dispersion relations of TiN bulk and we predict the effect of pressure on its optoelectronic properties. Our results explain the main features of TiN in the visible range and prove a universal scaling law which relates its mechanical and plasmonic properties as a function of pressure. Finally, we address the formation and stability of surface-plasmon polaritons at different TiN-dielectric interfaces proposed by recent experiments. The unusual combination of plasmonics and refractory features paves the way for the realization of plasmonic devices able to work at conditions not sustainable by the usual noble metals.

  16. Processes for preparing novel baddeleyite refractory articles

    Energy Technology Data Exchange (ETDEWEB)

    McGarry, Ch.N.; Stunis, J.; Wehrenberg, Th.M.

    1984-07-24

    A novel process for fabricating novel high zirconia content refractory articles directly from novel sinterable compositions including as the major ingredient thereof baddeleyite ore concentrates thereby reducing costs. Appropriate additives, particularly zircon, further provide enhanced resistance to thermal shock damage. Plasticizers, binders and other processing aids are identified for press forming exemplary compositions into continuous casting nozzles, shrouds and other ceramic products typically used in the processing of molten steel, specialty metals and glass.

  17. [Treatment of refractory ascites].

    Science.gov (United States)

    Martínez, Javier; Albillos, Agustín

    2014-07-01

    Ascites is a common complication of hepatic cirrhosis and portal hypertension. Patients present systemic and splanchnic circulation disorders, which cause central hypovolemia and arterial hypotension, with the subsequent activation of vasoconstrictor systems and increased renal reabsorption of sodium and water. Approximately 5%-10% of patients present refractory ascites. Refractory ascites is considered when it is not controllable with standard dietary (sodium restriction) and diuretic (furosemide up to 160 mg a day and spironolactone up to 400mg a day) treatment or when patients present adverse effects due to diuretics that impede their administration at optimum dosages. The current therapeutic options for these patients are repeated evacuative paracentesis and the percutaneous intrahepatic portosystemic shunt. Despite these treatments, refractory ascites has a poor prognosis; patients should therefore be assessed for liver transplantation. Copyright © 2014 Elsevier España, S.L. All rights reserved.

  18. "A High Speed Laser Profiling Device for Refractory Lininig Thickness Measurements In a Gasifier with Cross-Cut to the Metals, Forest Products, Chemical and Power Generation Industries"

    Energy Technology Data Exchange (ETDEWEB)

    Michel Bonin; Tom Harvill; Jared Hoog; Don Holve; Alan Alsing; Bob Clark; Steve Hrivnak

    2007-11-01

    Process Metrix began this project with the intent of modifying an existing ranging system and combining the same with a specially designed optical scanner to yield three dimensional range images that could be used to determine the refractory lining thickness in a gasifier. The goal was to make these measurements during short outages while the gasifier was at or near operating temperature. Our initial estimates of the photon counts needed for the modulation-based range finder were optimistic, and we were forced to undertake a redesign of the range finder portion of the project. This ultimately created significant and unanticipated time delays that were exacerbated when Acuity Technologies, the subcontractor responsible for delivering the redesigned range finder, failed to deliver electrical components capable of meeting the specific range error requirements needed for accurate lining thickness measurement. An extensive search for an alternate, off-the-shelf solution was unsuccessful, and Process Metrix was forced to undertake the electronics development internally without project funds. The positive outcome of this effort is a documented set of range finder electronics that have exceptional accuracy, simplicity, temperature stability and detection limit; in sum a package perfectly suited to the measurement requirements and within our control. It is unfortunate yet understandable, given the time delays involved in reaching this milestone, that the Department of Energy decided not to continue the project to completion. The integration of this electronics set into the optomechanical hardware also developed within the scope of the project remains as follow-on project that Process Metrix will finish within the calendar year 2008. Testing in the gasifier is, at this point, not certain pending the award of additional funding needed for field trials. Eastman, our industrial partner in this project, remains interested in evaluating a finished system, and working together we

  19. Dynamic Testing of Gasifier Refractory

    Energy Technology Data Exchange (ETDEWEB)

    Michael D. Mann; Wayne S. Seames; Devdutt Shukla; Xi Hong; John P. Hurley

    2005-12-01

    The University of North Dakota (UND) Chemical Engineering Department in conjunction with the UND Energy & Environmental Research Center (EERC) have initiated a program to examine the combined chemical (reaction and phase change) and physical (erosion) effects experienced by refractory materials under slagging coal gasification conditions. The goal of this work is to devise a mechanism of refractory loss under these conditions. The controlled-atmospheric dynamic corrodent application furnace (CADCAF) was utilized to simulate refractory/slag interactions under dynamic conditions that more realistically simulate the environment in a slagging coal gasifier than any of the static tests used previously by refractory manufacturers and researchers. High-alumina and high-chromia refractory bricks were tested using slags obtained from two solid fuel gasifiers. Testing was performed at 1475 C in a reducing atmosphere (2% H{sub 2} in N{sub 2}) The CADCAF tests show that high-chrome refractories have greater corrosion resistance than high-aluminum refractories; coal slag readily diffuses into the refractory through its grain boundaries; the refractory grains are more stable than the matrix in the tests, and the grains are the first line of defense against corrosion; calcium and alkali in the slag are more corrosive than iron; and silicon and calcium penetrate the deepest into the refractory. The results obtained from this study are preliminary and should be combined with result from other research programs. In particular, the refractory corrosion results from this study should be compared with refractories removed from commercial gasifiers.

  20. 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...

  1. Determination of vanadium in refractory metals, steel, cast iron, alloys and silicates by extraction of an NBPHA complex from a sulphuric-hydrofluoric acid medium.

    Science.gov (United States)

    Donaldson, E M

    1970-07-01

    A method for determining up to 0.15% of vanadium in high-purity niobium and tantalum metals, cast iron, steel, non-ferrous alloys and silicates is described. The proposed method is based on the extraction of a red vanadium(V)-N-benzoyl-N-phenylhydroxylamine complex into chloroform from a sulphuric-hydrofluoric acid medium containing excess of ammonium persulphate as oxidant. The molar absorptivity of the complex is 428 l.mole(-1).mm(-5) at 475 nm, the wavelength of maximum absorption. Interference from chromium(VI) and cerium(IV) is eliminated by reduction with iron(II). Common ions, including large amounts of titanium, zirconium, molybdenum and tungsten, do not interfere.

  2. Status epilepticus: Refractory and super-refractory.

    Science.gov (United States)

    Dubey, Deepanshu; Kalita, Jayantee; Misra, Usha K

    2017-01-01

    Status epilepticus (SE) is an important neurological emergency. It is defined as seizures lasting for 5 minutes or more or recurrent seizures without recovery of consciousness to baseline between the attacks. Refractory SE (RSE) is defined as SE persisting despite sufficient dose of benzodiazepines and at least one antiepileptic drug (AED), irrespective of time. Super refractory SE (SRSE) is defined as SE that continues for 24 hours or more after the use of anesthetic therapy, including cases that recur on weaning of the anesthestic agent. RSE occurs in 23%-48% of the patients and SRSE in approximately 22% of the patients with SE. In general, RSE occurs in patients with new-onset seizures rather than in patients with chronic epilepsy. The etiology of RSE in developing countries is dominated by central nervous system (CNS) infections and head injury compared to stroke and drug withdrawal in the developed countries. The treatment of RSE and SRSE is not evidence based. Following benzodiazepines, the second line antiepileptic drugs include sodium valproate, phenytoin, levetiracetam, and anesthetic drugs such as midazolam, phenobarbital, and propofol. Most intravenous anesthetic drugs produce hypotension and respiratory suppression; therefore, patients with RSE are managed in intensive care units (ICUs). In RSE patients, electroencephalogram (EEG) burst suppression with interburst interval of 2-20 s or even flat EEG has been tried. Recently, concerns have been raised on the safety of burst suppression in RSE and SRSE. The paucity of ICUs in developing countries limits the use of these management protocols. There is a need to explore intravenous AEDs with safer cardiovascular and respiratory profile for the management of SE.

  3. Refractory rheumatoid vasculitis.

    Science.gov (United States)

    Kumar, Ashok; Goel, Anshul; Lapsiwala, Mehul; Singhal, Suman

    2016-11-01

    Systemic rheumatoid vasculitis (SRV) can develop in rheumatoid arthritis of long duration and high disease activity. It most commonly manifests as cutaneous vasculitis and mononeuritis multiplex. This can involve any organ of the body and carries very high mortality. We report a case of a young male who had rheumatoid arthritis for the past 15 years and became refractory to standard drugs and anti-TNF agents. He subsequently developed SRV, which started as mononeuritis multiplex. Disease progressed to result in gangrene of hands and feet despite receiving intravenous cyclophosphamide. Intravenous immunoglobulin and rituximab also could not provide any response. Prolonged ICU stay resulted in critical care neuromyopathy. Central nervous system vasculitis developed even after repeated infusions of intravenous immunoglobulins and at last he died of complications. In this case report, we have presented rare and chronic protracted presentation of rheumatoid vasculitis involving skin, nerves, brain and testis, which was refractory to the recommended therapies.

  4. Refractoriness in human atria

    DEFF Research Database (Denmark)

    Skibsbye, Lasse; Jespersen, Thomas; Christ, Torsten

    2016-01-01

    rhythm and chronic atrial fibrillation tissues and was neither affected by changes in frequency (1 vs. 3Hz). CONCLUSIONS: Our results suggest a preferentially voltage-dependent, rather than time-dependent, effect with respect to refractoriness at physiologically relevant rates in human atria. However...... 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...

  5. Periclase-chromite refractories from fused materials

    Energy Technology Data Exchange (ETDEWEB)

    Slovikovskii, V.V.; Eroshkina, V.I.; Kononenko, G.V.; Nechistykh, G.A.; Simonov, K.V.

    1985-11-01

    Experiments were carried out to obtain high-grade fused chromitepericlase. It is shown that during the melting of batch consisting of raw magnesite and chromite ore the process of reducing the chromite ore to metallic ferrochromium is eliminated, which adversely affects both the content of Cr/sub 2/O/sub 3/ in the fused material, and also the commercial appearance of the resulting refractories. The authors developed a technology for preparing periclase-chromite refractories with chrommite-periclase constituents. The goods obtained possess good physicoceramic properties and a low content of silicites. The articles thus prepared were used to make the linings of the most critical parts of the converters which allowed an increase to be made in the duration of campaigns for the Kivset units of 1.5-2 times.

  6. 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.

  7. 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...

  8. IMPROVED CORROSION RESISTANCE OF ALUMINA REFRACTORIES

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Recent advances in refractories for steelmaking. Seikoyo taikabutsu no shinpo

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, K. (Nippon Steel Corp., Tokyo (Japan))

    1994-05-07

    Advances and problems of refractories for steelmaking are explained. With the division of refining functions in the steel manufacturing process, and the development of new processes, functions which comply to them are being demanded for refractories. Progress related to the main refractories is summarized. Long-life refractories such as magnesite-carbon bricks, alumina-carbon silicate-carbon bricks, magnesite-chrome bricks were developed, and the unit requirement of furnace materials was reduced by 25% in 10 years. Labor-saving in furnace construction work also advanced by the development of the wall construction methods based on execution of casting process. For realization of high quality steel, ladles made of neutral alumina-spinel which does not contaminate the steel are used. For the preliminary treatment process of hot metal, ASC bricks and glass-added ASC bricks were developed as refractories, and the unit requirement was reduced. For converters, MgO-C bricks which have anticorrosion properties as well as antispalling properties are being broadly used. As for RH of secondary refining facility, magnesite-chrome type basic bricks which cope with the very severe conditions are used. For the ladle, alumina-spinel type casting material is used in order to save labor and to improve the quality of the steel. However, in the case of continuous casting, various types of refractories having special functions are used. 35 refs., 16 figs.

  10. Refractory Celiac Disease

    Directory of Open Access Journals (Sweden)

    K Khatami

    2014-04-01

    Full Text Available Refractory celiac disease (RCD is when malabsorption symptoms and villous atrophy persist despite strict adherence to a gluten free diet (GFD for more than 12 months and other causes of villous atrophy have been ruled out.  RCD is considered a rare disease and almost exclusively occurs in adults. Persistent diarrhea, abdominal pain, weight loss are the most common symptoms in RCD. Also, anemia, fatigue, malaise, thromboembolic events and coexisting autoimmune disorders are frequent. Diagnosis of RCD is based on other causes of unresponsiveness to the GFD, particularly collagenous sprue, ulcerative jejunitis, and enteropathy-associated T-cell lymphoma. Many disorders such as autoimmune enteropathy, tropical sprue, common variable immunodeficiency, and intolerance to non-gluten dietary proteins may have similar histological findings but not necessarily identical with CD and therefore should be excluded. Repeat intestinal biopsy may help to differentiate causes of non-responsive CD associated with ongoing villous atrophy (e.g., gluten contamination, small-bowel bacterial overgrowth, RCD. There are 2 subtypes of RCD according to absence (type I or presence (type II of an abnormal intraepithelial lymphocyte population. RCD type 1 usually becomes better with a combination of aggressive nutritional support, adherence to GFD, and pharmacologic therapies such as prednisone, budesonide and azathioprine. For RCD type 2, more aggressive therapeutic approach is needed since clinical response to therapies is less certain and may evolve into aggressive enteropathy associated T-cell lymphoma and the prognosis is poor.   Key words: Celiac Disease, Refractory.  

  11. 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.

  12. [Lamotrigine in refractory epilepsy].

    Science.gov (United States)

    García-Escrivà, A; López-Hernández, N; Alvarez-Saúco, M; Pampliega-Pérez, A; Oliver-Navarrete, C; Asensio-Asensio, M; Moltó-Jordá, J M; Palao-Sánchez, A

    Lamotrigine (LTG) is a new antiepileptic drug indicated in all kinds of partial and generalised clonic-tonic seizures, both in monotherapy and polytherapy. Between 20 and 30% of epileptic patients have poor control over their seizures despite adequate treatment. We report on our experience regarding the long-term efficacy and tolerability of LTG in refractory seizures. We conducted a consecutive 10-year study of patients who began LTG therapy following poor control of their seizures, in spite of being treated with two or more antiepileptic drugs in monotherapy or in combination. Both their epidemiological and clinical data were collected for study. We studied the efficacy of the treatment, differentiating between remission (absence of seizures), improvement (reduction>50% of the seizures), inefficacy (reductionepilepsy, in 28.5% it was symptomatic and in the remaining 28.5% it was idiopathic. EEG readings and neuroimaging scans were pathological in 53.8% and 43.6%, respectively. After beginning therapy with LTG, 33% remained free of seizures, 43.6% improved, in 18.3% it was seen to be ineffective and 5.1% got worse. Dropout rate was 56.4%:23.1% due to insufficient control over the seizures, 17.9% owing to side effects and 15.4% because of non-compliance. Treatment with LTG offers a high degree of efficacy in the control of seizures in patients with refractory epilepsy, although it is limited by a high dropout rate.

  13. Platinum Group Coatings for Refractory Metals

    Science.gov (United States)

    1984-06-01

    molybdenum , tungsten, tantalum, niobium, rhenium or carbon/carbon must be used to fabricate the parts to withstand these temperatures. These materials and...layers (eg silicides, borides ) o Alloy coatings that form compact oxide layers (Ni and Co F based alloys) o Stable oxides that provide physical barriers...thermally etched) surface and seems to promote adhesion. Molybdenum rods 3mm in diameter were used as substrates during many of the runs where the

  14. REFRACTORY COATING FOR GRAPHITE MOLDS

    Science.gov (United States)

    Stoddard, S.D.

    1958-06-24

    Refractory coating for graphite molds used in the casting of uranium is described. The coating is an alumino-silicate refractory composition which may be used as a mold surface in solid form or as a coating applied to the graphite mold. The composition consists of a mixture of ball clay, kaolin, alumina cement, alumina, water, sodium silicate, and sodium carbonate.

  15. Monel Metal Castings

    Science.gov (United States)

    1935-07-17

    foot is adequate. A refractory , open sand should be used. Melting and Casting: The alloys are successfully produced from electro-nickel and copper...desirable if the charge is not chiefly Monel Metal scrap. About 0.1% magnesium should be ;ell stirred into the melt in the ladle before pouring. The addition...such as is used for the more refractory valve trim alloys. Carboloy tools probably can be used to advantage for the high silicon Monel Metal alloys

  16. Ciclosporin and refractory colitis.

    Science.gov (United States)

    Hawthorne, A Barney

    2003-03-01

    Intravenous ciclosporin 4 mg/kg daily is rapidly effective as a salvage therapy for patients with refractory colitis, who would otherwise face colectomy, but its use is controversial because of risk of toxicity, and long-term failure rate. Opportunistic infections remain a serious concern, with a number of reports of death related to ciclosporin. Renal and neurotoxicity are also well-recognized. The drug should not be continued for more than 3-6 months and its main role is as a bridge to azathioprine or 6-mercaptopurine. Risks of toxicity can be reduced by using lower doses (2 mg/kg/day intravenously), by oral microemulsion ciclosporin, or by monotherapy without corticosteroids. Preliminary evidence shows good response rates, but further studies are needed to confirm optimal use of this potent, but hazardous, therapy.

  17. Management of Refractory Vasodilatory Shock.

    Science.gov (United States)

    Jentzer, Jacob C; Vallabhajosyula, Saraschandra; Khanna, Ashish K; Chawla, Lakhmir S; Busse, Laurence W; Kashani, Kianoush B

    2018-01-09

    Refractory shock is a lethal manifestation of cardiovascular failure defined by an inadequate hemodynamic response to high doses of vasopressor medications. Approximately 7% of critically ill patients will develop refractory shock, with short-term mortality exceeding 50%. Refractory vasodilatory shock develops from uncontrolled vasodilation and vascular hyporesponsiveness to endogenous vasoconstrictors, causing failure of physiologic vasoregulatory mechanisms. Standard approaches to the initial management of shock include fluid resuscitation and initiation of norepinephrine. When these measures are inadequate to restore BP, vasopressin or epinephrine can be added. Few randomized studies exist to guide clinical management and hemodynamic stabilization in patients who do not respond to this standard approach. Adjunctive therapies, such as hydrocortisone, thiamine, and ascorbic acid, may increase BP in severe shock and should be considered when combination vasopressor therapy is needed. Novel vasopressor agents, such as synthetic human angiotensin II, can increase BP and reduce the need for high doses of catecholamine vasopressors in severe or refractory vasodilatory shock. Few effective rescue therapies exist for established refractory shock, which emphasizes the importance of aggressive intervention before refractory shock develops, including the earlier initiation of rational combination vasopressor therapy. The present review discusses the diagnosis and management of refractory shock to offer guidance for management of this important clinical problem and to provide a framework for future research. Copyright © 2018 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  18. Timing Challenges for Very Deep Sub-Micron (VDSM IC

    Directory of Open Access Journals (Sweden)

    Ichiang Lin

    2002-01-01

    Full Text Available Many IC design houses failed to be market leaders because they miss the market window due to timing closure problems. Compared to half-micron designs, the amount of time spent on timing verification has greatly increased. Cell delays can be accurately estimated during logic synthesis. However, interconnect delays are unknown until the wire geometry is defined in physical design. Logic synthesis using the cell library models for interconnect delay estimates may be statistically accurate, but can not predict the delay of individual nets accurately. Delay estimates for individual nets (global nets, long wires, large fan-outs, buses, which matter most for the critical paths can be inaccurate and cause a design failure. Inaccurate timing verification causes silicon failure in shipped products that results in the loss of millions of dollars spent designing a high-performance product and potentially larger costs due to lost market share. Full-chip, sign-off verification with silicon-accuracy will allow these problems to be discovered and fixed before tape-out.

  19. Dynamics of vortex matter in YBCO sub-micron bridges

    Science.gov (United States)

    Papari, G.; Carillo, F.; Stornaiuolo, D.; Massarotti, D.; Longobardi, L.; Beltram, F.; Tafuri, F.

    2014-11-01

    We have developed a fabrication process that allows us to realize pure YBCO nanowires displaying robust superconductivity at widths w as low as 160 nm. We can modify the process in order to maintain a Au protective layer. This allows us to scale our nanowires even further to widths as low as 50 nm. We have studied how the presence of vortices and the occurrence of phase slips affect the transport properties of nanowires in the width range ξ entry barrier is found to scale with the width. Our findings confirm that for widths ξ < w < λ nanowires are better protected against phase slips and vortex flow.

  20. Sub-micron surface plasmon resonance sensor systems

    Science.gov (United States)

    Glazier, James A. (Inventor); Amarie, Dragos (Inventor)

    2013-01-01

    Wearable or implantable devices combining microfluidic control of sample and reagent flow and micro-cavity surface plasmon resonance sensors functionalized with surface treatments or coatings capable of specifically binding to target analytes, ligands, or molecules in a bodily fluid are provided. The devices can be used to determine the presence and concentration of target analytes in the bodily fluids and thereby help diagnose, monitor or detect changes in disease conditions.

  1. W-CMP for sub-micron inverse metallisation

    NARCIS (Netherlands)

    van Kranenburg, H.; van Corbach, H.D.; Woerlee, P.H.; Lohmeier, Martin

    1997-01-01

    Chemical Mechanical Polishing (CMP) of tungsten for an inverse metallisation scheme is investigated. The influence of CMP parameters on removal rate and uniformity is studied. The main effects on the removal rate are the applied pressure and the rotation rate of the polishing pad. To the first order

  2. Nano-ring arrays for sub-micron particle trapping

    Science.gov (United States)

    Han, Xue; Truong, Viet Giang; Nic Chormaic, Síle

    2017-04-01

    Plasmonic tweezers based on nano-ring arrays on gold thin film are demonstrated. A cylindrical surface plasmon resonance is generated in the aperture of a nano-ring and a transmission peak results. When nano-slits are included to connect the nano-rings, the transmission peak becomes narrower. When the size of the aperture of the nano-ring is reduced, this peak is red-shifted. Both 0.5 μm and 1 μm polystyrene particles are trapped successfully by nano-ring arrays. A self-induced back-action effect is observed when a red-shifted laser beam is used. With multiple trapping sites provided by the nano-ring array, this type of plasmonic tweezers has huge potential to be integrated in lab-on-a-chip systems for life sciences research.

  3. Sub-micron surface plasmon resonance sensor systems

    Science.gov (United States)

    Glazier, James A. (Inventor); Amarie, Dragos (Inventor)

    2012-01-01

    A sensor for detecting the presence of a target analyte, ligand or molecule in a test fluid, comprising a light transmissive substrate on which an array of surface plasmon resonant (SPR) elements is mounted is described. A multi-channel sensor for detecting the presence of several targets with a single microchip sensor is described. A multi-channel sensor including collections of SPR elements which are commonly functionalized to one of several targets is also described. The detectors sense changes in the resonant response of the SPR elements indicative of binding with the targets.

  4. Physics of sub-micron cosmic dust particles

    Science.gov (United States)

    Roy, N. L.

    1974-01-01

    Laboratory tests with simulated micrometeoroids to measure the heat transfer coefficient are discussed. Equations for ablation path length for electrically accelerated micrometeoroids entering a gas target are developed which yield guidelines for the laboratory measurement of the heat transfer coefficient. Test results are presented for lanthanum hexaboride (LaB sub 6) microparticles in air, argon, and oxygen targets. The tests indicate the heat transfer coefficient has a value of approximately 0.9 at 30 km/sec, and that it increases to approximately unity at 50 km/sec and above. Test results extend to over 100 km/sec. Results are also given for two types of small particle detectors. A solid state capacitor type detector was tested from 0.61 km/sec to 50 km/sec. An impact ionization type detector was tested from 1.0 to 150 km/sec using LaB sub 6 microparticles.

  5. Metrology of sub-micron structured polymer surfaces

    DEFF Research Database (Denmark)

    Quagliotti, Danilo; Tosello, Guido; Salaga, J.

    surface replication of the tool insert component when moulding the polymer melt [1]. This aspect is particularly critical when dealing with increasingly small dimensional scales in micro- and nano-structured surfaces [2, 3].In this context, a metrological investigation of polymer replicated surfaces using...

  6. Sub-Micron Grinding of a Food Product

    NARCIS (Netherlands)

    Hennart, S.L.A.

    2011-01-01

    This thesis describes how the activity of a preservative product used in food coatings can be optimized. This project is partly sponsored by the European Marie Curie Framework projects as part of the BioPowders research training network. DSM Food Specialties hosts and co finances this project. The

  7. Investigation of Appropriate Refractory Material for Laboratory Electritic Resistrance Furnance

    Directory of Open Access Journals (Sweden)

    J.B Agboola

    2009-07-01

    Full Text Available There have been numerous efforts to increase the local content of furnaces; hence the choice of appropriate refractory material for lining of locally manufactured furnaces has remained a major concern. This research work investigates the choice of appropriate local refractory material for the lining of laboratory electric resistance furnace.Electric resistance furnaces are extensively used in the laboratory for heat treatment of metals and alloys. Refractory binders such as silicon carbide were experimented upon for strength and resistance to high temperature.The results obtained showed that Kankara fireclay containing 15% SiC ( 5.70 % linear shrinkage , 46.2% apparent porosity, 1.77gkm³ Bulk density, 18 cycles of spalling tests at 1300°C, 5.253KN/m² of cold strength has appropriate properties for producing grooved bricks for lining of laboratory electric resistance Furnace.

  8. Intrathecal ziconotide for refractory pain.

    Science.gov (United States)

    Doggrell, Sheila A

    2004-07-01

    For cancer and AIDS patients, 10-30% of pain is refractory to strong opioids, requiring intraspinal administration for pain management. Ziconotide is a selective N-type calcium channel blocker, which inhibits neurotransmitter release, and following intrathecal administration will affect primary nociceptive afferents. In 108 patients with previously unmanaged refractory pain despite the use of systemic or intrathecal opioids, in the initial titration phase, the mean Visual Analogue Scale of Pain Intensity scores improved more in the ziconotide group (53%) than the placebo group (18%). Serious adverse effects were more common in the ziconotide group (31%) than placebo group (10%) in the initial titration phase. In the 48 patients receiving ziconotide, who proceeded to the maintenance phase, the benefit of ziconotide was continued. Until a new approach with a better effectiveness/adverse effects profile than ziconotide for refractory pain emerges, further optimisation of ziconotide for use in the treatment of refractory pain should be undertaken.

  9. 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

    Bulk vitrification (BV) was selected for a pilot-scale test and demonstration facility for supplemental treatment to accelerate the cleanup of low-activity waste (LAW) at the Hanford U.S. DOE Site. During engineering-scale (ES) tests, a small fraction of radioactive Tc (and Re, its nonradioactive surrogate) were transferred out of the LAW glass feed and molten LAW glass, and deposited on the surface and within the pores of the castable refractory block (CRB). Laboratory experiments were undertaken to understand the mechanisms of the transport Tc/Re into the CRB during vitrification and to evaluate various means of CRB protection against the deposition of leachable Tc/Re. The tests used Re as a chemical surrogate for Tc. The tests with the baseline CRB showed that the molten LAW penetrates into CRB pores before it converts to glass, leaving deposits of sulfates and chlorides when the nitrate components decompose. Na2O from the LAW reacts with the CRB to create a durable glass phase that may contain Tc/Re. Limited data from a single CRB sample taken from an ES experiment indicate that, while a fraction of Tc/Re is present in the CRB in a readily leachable form, most of the Tc/Re deposited in the refractory is retained in the form of a durable glass phase. In addition, the molten salts from the LAW, mainly sulfates, chlorides, and nitrates, begin to evaporate from BV feeds at temperatures below 800 C and condense on solid surfaces at temperatures below 530 C. Three approaches aimed at reducing or preventing the deposition of soluble Tc/Re within the CRB were proposed: metal lining, sealing the CRB surface with a glaze, and lining the CRB with ceramic tiles. Metal liners were deemed unsuitable because evaluations showed that they can cause unacceptable distortions of the electric field in the BV system. Sodium silicate and a low-alkali borosilicate glaze were selected for testing. The glazes slowed down molten salt condensate penetration, but did little to reduce the

  10. Three-dimensional Hierarchical Metal oxide-Carbon Electrode Material for High Efficient Microbial Electrosynthesis

    DEFF Research Database (Denmark)

    Cui, Mengmeng; Nie, Huarong; Zhang, Tian

    2017-01-01

    pore structure in a microwave oven is demonstrated. Microwave pyrolysis of ferrocene using carbon felt as a microwave absorber, a method that is rapid (tens of seconds), does not require harsh conditions nor costly equipment is utilized, and can be readily scaled up. The produced material has a high......The production of hierarchical hybrid conductive materials that are mesoporous, with pores spanning from sub-micron to microns in size, is important for large-area electrode applications. Here, a simple one-step, low-cost method to fabricate a metal oxide-carbon hybrid materials with a hierarchical...

  11. Impact of alternate fuels on industrial refractories and refractory insulation applications. An Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Wei, G.C.; Tennery, V.J.

    1976-09-01

    The effects of use of alternate fuels such as distillate oils, residual oils, coal, producer gas, and electricity on refractory insulation are evaluated. Sections are included on alternate fuels for 1976 to 1980, assessment by industry of fuel conversion impact on industrial refractories in the period 1976 to 1980, interactions of alternate fuel combustion products with refractories and refractory insulation, and analysis of degradation mechanisms in refractories and refractory materials. (JRD)

  12. Testing Requirements for Refractory Materials

    Science.gov (United States)

    Calle, Luz Marina; Hintze, Paul E.; Parlier, Christopher R.; Curran, Jerome P.; Kolody, Mark R.; Sampson, Jeffrey W,; Montgomery, Eliza M.

    2012-01-01

    Launch Pads 39A and 39B currently use refractory material (Fondu Fyre) in the flame trenches. This material was initially approved for the Saturn program. This material had a lifetime of 10years according to the manufacturer, and it has been used for over 40 years. As a consequence, the Fondu Fyre at Launch Complex 39 requires repair subsequent to almost every launch. A review of the literature indicates that the gunned Fondu Fyre refractory product (WA-1 G) was never tested prior to use. With the recent severe damage to the flame trenches, a new refractory material is sought to replace Fondu Fyre. In order to replace Fondu Fyre, a methodology to test and evaluate refractory products was developed. This paper outlines this methodology and discusses current testing requirements, as well as the laboratory testing that might be required. Furthermore, this report points out the necessity for subscale testing, the locations where this testing can be performed, and the parameters that will be necessary to qualify a product. The goal is to identify a more durable refractory material that has physical, chemical, and thermal properties suitable to withstand the harsh environment of the launch pads at KSC.

  13. 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.

  14. Brazing Dissimilar Metals

    Science.gov (United States)

    Krotz, Phillip D.; Davis, William M.; Wisner, Daniel L.

    1996-01-01

    Brazing effective technique for joining ordinary structural metals to brittle, low-thermal-expansion refractory metals. Specifically, brazing process established for joining copper or nickel flanges to ends of vacuum-plasma-sprayed tungsten tubes and for joining stainless-steel flanges to ends of tubes made of alloy of molybdenum with 40 percent of rhenium.

  15. Infliximab for refractory oral ulcers.

    Science.gov (United States)

    Ryu, Hee Jung; Seo, Mi Ryoung; Choi, Hyo Jin; Baek, Han Joo

    2014-01-01

    Recurrent oral ulcer (ROU) is a common condition that significantly impacts quality of life. It is often related to systemic diseases, such as Behçet's disease (BD), Crohn's disease, and ulcerative colitis. Treatment of ROU depends on its severity: from topical agents for mild cases to systemic agents, such as corticosteroids, azathioprine, or other immunosuppressants for severe cases. Recently, good results have been reported with infliximab in refractory ROU. However, the optimal dosage and treatment duration have not been determined and the cost and potential side effects should be considered. We report on four patients who received a single-dose infliximab for refractory ROU. Two patients had refractory ROU with no underlying disease; one of them had soft palate perforation accompanied by severe oral ulcers. The two other patients had ROU of BD without major organ involvement. All patients received a single infusion of infliximab and an additional infusion was given on demand in one patient. Infliximab showed a rapid, good response in three patients and was also effective in improving the acute inflammation in the perforation of the soft palate, which had been resistant to conventional therapies. These effects diminished over a few weeks, but the ROU were tolerable and it was not necessary to increase steroids or add another medicine for about 1 year. We suggest that a single infusion of infliximab can be considered for refractory ROU. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Dexmedetomidine for Refractory Intracranial Hypertension.

    Science.gov (United States)

    Schomer, Kendra J; Sebat, Christian M; Adams, Jason Y; Duby, Jeremiah J; Shahlaie, Kiarash; Louie, Erin L

    2017-01-01

    Dexmedetomidine (DEX) is a selective α2 adrenergic agonist that is commonly used for sedation in the intensive care unit (ICU). The role of DEX for adjunctive treatment of refractory intracranial hypertension is poorly defined. The primary objective of this study was to determine the effect of DEX on the need for rescue therapy (ie, hyperosmolar boluses, extraventricular drain [EVD] drainages) for refractory intracranial hypertension. Secondary objectives included the number of intracranial pressure (ICP) excursions, bradycardic, hypotensive, and compromised cerebral perfusion pressure episodes. This retrospective cohort study evaluated patients admitted to the neurosurgical ICU from August 1, 2009, to July 29, 2015, and who received DEX for refractory intracranial hypertension. The objectives were compared between the 2 time periods-before (pre-DEX) and during therapy (DEX). Twenty-three patients with 26 episodes of refractory intracranial hypertension met the inclusion criteria. The number of hyperosmolar boluses was decreased after DEX therapy was initiated. Mannitol boluses required were statistically reduced (1 vs 0.5, P = .03); however, reduction in hypertonic boluses was not statistically significant (1.3 vs 0.9, P = .2). The mean number of EVD drainages per 24 hours was not significantly different between the time periods (15.7 vs 14.0, P = .35). The rate of ICP excursions did not differ between the 2 groups (24.3 vs 22.5, P = .62). When compared to pre-DEX data, there was no difference in the median number of hypotensive (0 vs 0), bradycardic (0 vs 0), or compromised cerebral perfusion pressure episodes (0.5 vs 1.0). Dexmedetomidine may avoid increases in the need for rescue therapy when used as an adjunctive treatment of refractory intracranial hypertension without compromising hemodynamics.

  17. Mechanical properties of refractory concretes for boilers; Propriedades mecanicas de concretos refratarios para caldeiras

    Energy Technology Data Exchange (ETDEWEB)

    Angioletto, E.; Pelisser, F.; Peterson, M.; Angioletto, E.; Rocha, M.R.; Arnt, A.B.C. [Universidade do Estado de Santa Catarina (UDESC), Criciuma, SC (Brazil)], E-mail: ean@unesc.net; Coelho, R. [Tractebel Energia, Florianpolis, SC (Brazil)

    2010-07-01

    Refractory concretes are used in extremely physically demanding conditions. An important example is concretes used as sealing systems in boilers, where their dimensional stability at high temperatures is fundamental to durability and has a strong impact on maintenance costs and system idleness. In this work, refractory concretes with different compositions were characterized and then tested by dilatometry, for compressive strength and in assays involving adherence between tensile concrete/metal inserts, simulating the fixing system in boilers. Analysis of the results showed that refractory concretes do not present retraction due to air during drying, eliminating the possibility of cracking. While casting the plate/prototype with metal inserts, satisfactory concrete/metal adherence was verified and surface cracking occurred that did not influence the tensile bond strength between the insert and the concrete. (author)

  18. Typical corrosion of alumina refractory in aluminum reflow oven; Corrosao tipica de refratarios aluminosos em forno de refusao de aluminio

    Energy Technology Data Exchange (ETDEWEB)

    Baldo, Jaoa B., E-mail: baldo@ufscar.br [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil)

    2014-07-01

    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{sub 2}O{sub 3}, SiO{sub 2} and TiO{sub 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{sub 2} and TiO{sub 2} contained in the refractory were reduced and transformed into their metallic elements causing an intense structural spalling. (author)

  19. 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.

  20. Wettability between molten slag and dolomitic refractory

    OpenAIRE

    Shen, Ping; Zhang, Lifeng; Wang, Yi; Sridhar, Seetharaman; Wang, Qiangqiang

    2016-01-01

    In the current study, the wettability between molten slag and dolomitic refractory materials used in the ladle during steel refining was investigated. The contact angle between molten slag and dolomitic substrate decreased with increasing temperature. The slag with lower basicity spread on the substrate more easily and penetrated deeper into the substrate. The penetration depth of slag into the refractory increased with the extension of holding time. The CaO in the refractory dissolved into s...

  1. 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...

  2. 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...

  3. The improvement of slagging gasifier refractories

    Energy Technology Data Exchange (ETDEWEB)

    Kwong, K.-S.; Bennett, J.P.; Powell, C.A.; Krabbe, R.A.

    2006-03-01

    Refractories play a vital role in slagging gasifier on-line availability and profitability for the next clean power generation system. A recent survey of gasifier users by USDOE indicated that a longer service life of refractories is the highest need among gasifier operators. Currently, Cr2O3 based refractories, the best of commercially available materials for use in slagging gasifiers, last between 3 and 24 months. Researchers at Albany Research Center (ARC) have identified structural spalling, caused by slag penetration, as one of the major failure mechanisms of Cr2O3 refractories through postmortem analysis. New Cr2O3 refractories with phosphate additives have been developed by ARC to decrease slag penetration and thus structural spalling. Laboratory physical property tests indicated that ARC developed refractories are superior to other commercial bricks. One of the ARC developed phosphate containing refractories has been installed in a slagging gasifier. Preliminary results of the performance of this refractory in the gasifier will be reported along with research to develop non-chromia refractories.

  4. Iron refractory iron deficiency anemia

    Science.gov (United States)

    De Falco, Luigia; Sanchez, Mayka; Silvestri, Laura; Kannengiesser, Caroline; Muckenthaler, Martina U.; Iolascon, Achille; Gouya, Laurent; Camaschella, Clara; Beaumont, Carole

    2013-01-01

    Iron refractory iron deficiency anemia is a hereditary recessive anemia due to a defect in the TMPRSS6 gene encoding Matriptase-2. This protein is a transmembrane serine protease that plays an essential role in down-regulating hepcidin, the key regulator of iron homeostasis. Hallmarks of this disease are microcytic hypochromic anemia, low transferrin saturation and normal/high serum hepcidin values. The anemia appears in the post-natal period, although in some cases it is only diagnosed in adulthood. The disease is refractory to oral iron treatment but shows a slow response to intravenous iron injections and partial correction of the anemia. To date, 40 different Matriptase-2 mutations have been reported, affecting all the functional domains of the large ectodomain of the protein. In vitro experiments on transfected cells suggest that Matriptase-2 cleaves Hemojuvelin, a major regulator of hepcidin expression and that this function is altered in this genetic form of anemia. In contrast to the low/undetectable hepcidin levels observed in acquired iron deficiency, in patients with Matriptase-2 deficiency, serum hepcidin is inappropriately high for the low iron status and accounts for the absent/delayed response to oral iron treatment. A challenge for the clinicians and pediatricians is the recognition of the disorder among iron deficiency and other microcytic anemias commonly found in pediatric patients. The current treatment of iron refractory iron deficiency anemia is based on parenteral iron administration; in the future, manipulation of the hepcidin pathway with the aim of suppressing it might become an alternative therapeutic approach. PMID:23729726

  5. Plasmonic excitations on metallic nanowires embedded in silica photonic crystal fibers

    Energy Technology Data Exchange (ETDEWEB)

    Prill Sempere, Luis

    2010-06-17

    This thesis describes the theoretical and experimental investigation of metal-filled photonic crystal fibers (PCFs) and their fabrication. The thesis explains how to overcome the obstacles when infiltrating molten metals into sub-micron holes in fused silica (SiO{sub 2}) PCF. The optical properties of such filled fibers are theoretically and experimentally investigated, focusing on the coupling between the core mode of the fibers and the surface plasmon polaritons (SPPs) on the metal wires. The thesis introduces the ideas, physical challenges and results of two new filling techniques: the pressure cell technique and the splicing technique. These techniques make it possible for the first time to fill different fiber structures with sub-micron sized holes, such as PCFs and single-hole capillaries, with different metals like gold (Au) and silver (Ag). Samples with hole diameters between 120 nm and 20 {mu}m and aspect ratios as high as 75000 have been realized. Theoretical simulations and models have been developed in order to understand the optical behavior of these novel structures. The light guided in the core of the filled PCF structure will couple to SPP modes on the wires. Several measurements have been performed to determine the resonance wavelengths and losses of such filled PCF structures. Also, different phenomena such as the shift of the resonance position with the wire diameter or pitch and the polarization dependence of SPP in polarization maintaining (PM)-PCF have been investigated. The fabrication of free standing metal arrays was another focus of this work. The critical question was how to remove the surrounding SiO{sub 2} from the metal wires. Two different approaches have been tried: etching of the SiO{sub 2} and cleaving the PCF. (orig.)

  6. 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 ...

  7. Neuroimaging evaluation in refractory epilepsy.

    Science.gov (United States)

    Granados, Ana M; Orejuela, Juan F; Rodriguez-Takeuchi, Sara Y

    2015-10-01

    To describe the application of neuroimaging analysis, compared to neuropsychological tests and video-electroencephalogram, for the evaluation of refractory epilepsy in a reference centre in Cali, Colombia. Between March 2013 and November 2014, 29 patients, 19 men and 10 women, aged 9-65 years and with refractory epilepsy, were assessed by structural and functional magnetic resonance imaging while performing tasks related to language, verbal and non-verbal memory. Also, volumetric evaluation was performed. A 1.5 Tesla magnetic resonance imaging scanner was used in all cases. Neuroimaging evaluation identified 13 patients with mesial temporal sclerosis. The remaining patients were classified as: 10 patients with neoplastic masses, two patients with cortical atrophy, two patients with scarring lesions and two patients with non-structural aetiology. Among patients with mesial temporal sclerosis, comparison between techniques for lateralising the epileptogenic foci was made; the κ index between functional magnetic resonance imaging and hippocampi volumetry was κ=1.00, agreement between neuroimaging and video-electroencephalogram was good (κ=0.78) and comparison with a neuropsychological test was mild (κ=0.24). Neuroimaging studies allow the assessment of functional and structural damage related to epileptogenic lesions and foci, and are helpful to select surgical treatment, conduct intraoperative neuronavigation techniques, predict surgical deficits and evaluate patient recovery. © The Author(s) 2015.

  8. Refractory for Black Liquor Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Musa Karakus; Xiaoting Laing

    2005-10-01

    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

  9. REFRACTORY FOR BLACK LIQUOR GASIFIERS

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Musa Karakus; Jun Wei

    2005-03-01

    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

  10. NASA research on refractory compounds.

    Science.gov (United States)

    Gangler, J. J.

    1971-01-01

    The behavior and properties of the refractory carbides, nitrides, and borides are being investigated by NASA as part of its research aimed at developing superior heat resistant materials for aerospace applications. Fundamental studies on the electronic and defect structures of the carbides indicate that there is promise for improving the strength and ductility of these materials. Studies of the zirconium-carbon-oxygen system show that zirconium oxycarbides of different compositions and lattice parameters can be formed between 1500 and 1900 C and are stable below 1500 C. More applied studies show that hot working generally improves the microstructure and therefore the strength of TiC and NbC. Sintering studies on UN indicate that very high densities can be achieved. Hot pressing of cermets of HfN and HfC produces good mechanical properties for high temperature bearing applications.

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. Refractory for Black Liquor Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Alireza Rezaie

    2003-08-01

    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

  20. 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

  1. Refractory for Black Liquor Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Robert E. Moore; William L. Headrick; Alireza Rezaie

    2003-03-31

    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

  2. Primordial Compositions of Refractory Inclusions

    Energy Technology Data Exchange (ETDEWEB)

    Grossman, L; Simon, S B; Rai, V K; Thiemens, M H; Hutcheon, I D; Williams, R W; Galy, A; Ding, T; Fedkin, A V; Clayton, R N; Mayeda, T K

    2008-02-20

    Bulk chemical and oxygen, magnesium and silicon isotopic compositions were measured for each of 17 Types A and B refractory inclusions from CV3 chondrites. After bulk chemical compositions were corrected for non-representative sampling in the laboratory, the Mg and Si isotopic compositions of each inclusion were used to calculate its original chemical composition assuming that the heavy-isotope enrichments of these elements are due to Rayleigh fractionation that accompanied their evaporation from CMAS liquids. The resulting pre-evaporation chemical compositions are consistent with those predicted by equilibrium thermodynamic calculations for high-temperature nebular condensates but only if different inclusions condensed from nebular regions that ranged in total pressure from 10{sup -6} to 10{sup -1} bar, regardless of whether they formed in a system of solar composition or in one enriched in OC dust relative to gas by a factor of ten relative to solar composition. This is similar to the range of total pressures predicted by dynamic models of the solar nebula for regions whose temperatures are in the range of silicate condensation temperatures. Alternatively, if departure from equilibrium condensation and/or non-representative sampling of condensates in the nebula occurred, the inferred range of total pressure could be smaller. Simple kinetic modeling of evaporation successfully reproduces observed chemical compositions of most inclusions from their inferred pre-evaporation compositions, suggesting that closed-system isotopic exchange processes did not have a significant effect on their isotopic compositions. Comparison of pre-evaporation compositions with observed ones indicates that 80% of the enrichment in refractory CaO + Al{sub 2}O{sub 3} relative to more volatile MgO + SiO{sub 2} is due to initial condensation and 20% due to subsequent evaporation for both Type A and Type B inclusions.

  3. 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.

  4. Effect of Injection Smelting Jet Characteristics on Refractory Wear in the Mitsubishi Process

    Science.gov (United States)

    Goto, Moto; Echigoya, Takumi

    1980-11-01

    The Mitsubishi Process is a multi-furnace continuous copper smelting and converting process developed by Mitsubishi Metal Corporation. Developing a furnace lining system to minimize refractory wear in smelting and converting furnaces was one of the major objectives since the pilot plant started operation in 1968. Many efforts were directed toward developing techniques such as thickness control of slag layer, application of water-cooled jackets, fuel combustion control to avoid hot spots, and modification of furnace configuration. These efforts prolonged furnace life by a year, and are expected to extend it to several years in the near future. This paper discusses developments which have reduced refractory wear, and current refractory practice based on recent operating data.

  5. 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].

  6. 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).

  7. Ultra High Temperature Refractory Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Legacy refractory materials that have origins dating to the original Saturn program are commonly used in current launch facilities. Although they failure to meet the...

  8. Ultra High Temperature Refractory Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Legacy refractory materials that have origins dating to the original Saturn program are commonly used in current launch facilities. Although they fail to meet the...

  9. Emergency coronary angioplasty in refractory unstable angina

    NARCIS (Netherlands)

    P.J. de Feyter (Pim); P.W.J.C. Serruys (Patrick); M.J.B.M. van den Brand (Marcel); K. Balakumaran (Kulasekaram); A.L. Soward; P.G. Hugenholtz (Paul); A.E.R. Arnold (Alfred); B. Mochtar (Bas)

    1985-01-01

    textabstractWe performed percutaneous transluminal coronary angioplasty as an emergency procedure in 60 patients with unstable angina pectoris that was refractory to treatment with maximally tolerated doses of beta-blockers, calcium antagonists, and intravenous nitroglycerin. The initial success

  10. Functional outcome of prolonged refractory status epilepticus

    OpenAIRE

    Lai, Alexandre; Outin, Hervé D.; Jabot, Julien; Mégarbane, Bruno; Gaudry, Stéphane; Coudroy, Rémi; Louis, Guillaume; Schneider, Francis; Barbarot, Nicolas; Roch, Antoine; Lerolle, Nicolas; Luis, David; Fourrier, François; Renault, Anne; Argaud, Laurent

    2015-01-01

    International audience; Introduction:To characterize etiology, clinical course and outcomes of patients in prolonged refractory status epilepticus (PRSE) and looking for prognostic factors.Methods:Retrospective study conducted in patients hospitalized from January 1, 2001 to December 31, 2011 in 19 polyvalent intensive care units in French university and general hospitals. Patients were adults with a generalized convulsive refractory status epilepticus that lasted more than seven days, despit...

  11. Molecular Determinants of Hormone Refractory Prostate Cancer

    Science.gov (United States)

    2017-07-01

    Award Number: W81XWH-12-1-0062 TITLE: Molecular Determinants of Hormone Refractory Prostate Cancer PRINCIPAL INVESTIGATOR: Atish Choudhury...CONTRACTING ORGANIZATION: Dana-Farber Cancer Institute Boston, MA 02215 REPORT DATE: July 2017 TYPE OF REPORT: Annual PREPARED FOR: U.S. Army...Determinants of Hormone Refractory Prostate Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-12-1-0062 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Atish

  12. The Modified Atkins Diet in Refractory Epilepsy

    Directory of Open Access Journals (Sweden)

    Suvasini Sharma

    2014-01-01

    Full Text Available The modified Atkins diet is a less restrictive variation of the ketogenic diet. This diet is started on an outpatient basis without a fast, allows unlimited protein and fat, and does not restrict calories or fluids. Recent studies have shown good efficacy and tolerability of this diet in refractory epilepsy. In this review, we discuss the use of the modified Atkins diet in refractory epilepsy.

  13. 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.

  14. Refractory of Furnaces to Reduce Environmental Impact

    Energy Technology Data Exchange (ETDEWEB)

    Hanzawa, Shigeru, E-mail: hanzawa@ngk.co.jp [NGK Insulators, LTD., Mizuho, Nagoya (Japan)

    2011-10-29

    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{sub 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{sub 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.

  15. Rational use of refractories in regenerator checkers

    Energy Technology Data Exchange (ETDEWEB)

    Popov, O.N.; Borovkova, L.B.; Izosenkova, A.V.; Shatova, N.P.

    1985-09-01

    The thermal efficiency of regenerators in glass furnaces depends on the rational choice of the checker system and the refractory materials used in their construction. In order to develop practical recommendations for the rational use of refractories in checkers for sheet glass, container, and medical-glass furnaces, the authors carried out an all-around investigation of the resistance of aluminosilicate and magnesia refractories in laboratory conditions, modelling the actual service conditions of the material in the checkers. Magnesite, ordinary MO-89, compressed magnesite MU-91, magnesitechromite ordinary, MKhSO, periclase-spinel ordinary, PShSO, forsterite F, unfired magnesite-chromite BMKh, chamotte ShN-38, and highalumina DV-12 were selected as refractories. The use in checkers of magnesia refractories, bearing in mind their corrosion resistance, and with the elimination of the factors in the damaging action, will enable one to ensure prolonged service for the checkers without carrying out hot repairs during the campaign of furnaces producing sheet, container, and medical glasses.

  16. The fate of heavy metals during combustion and gasification of contaminated biomass—A brief review

    Energy Technology Data Exchange (ETDEWEB)

    Nzihou, Ange, E-mail: ange.nzihou@mines-albi.fr [Université de Toulouse, Mines Albi, CNRS, Centre RAPSODEE, Campus Jarlard, F-81013 Albi cedex 09 (France); Stanmore, Brian [Formerly of the University of Queensland, Brisbane, QLD 4072 (Australia)

    2013-07-15

    Highlights: ► A review on metal behaviour during the thermal treatment of contamined biomass. ► Wide range of biomass waste reported. ► Distribution of metals in the ash, and in the sub-micron particles discussed. -- Abstract: The literature on the presence of heavy metals in contaminated wastes is reviewed. Various categories of materials produced from domestic and industrial activities are included, but municipal solid waste, which is a more complex material, is excluded. This review considers among the most abundant the following materials – wood waste including demolition wood, phytoremediation scavengers and chromated copper arsenate (CCA) timber, sludges including de-inking sludge and sewage sludge, chicken litter and spent pot liner. The partitioning of the metals in the ashes after combustion or gasification follows conventional behaviour, with most metals retained, and higher concentrations in the finer sizes due to vaporisation and recondensation. The alkali metals have been shown to catalyse the biomass conversion, particularly lithium and potassium, although other metals are active to a lesser extent. The most prevalent in biomass is potassium, which is not only inherently active, but volatilises to become finely distributed throughout the char mass. Because the metals are predominantly found in the ash, the effectiveness of their removal depends on the efficiency of the collection of particulates. The potential for disposal into soil depends on the initial concentration in the feed material.

  17. Roasting of refractory gold and silver concentrate; Tostacion de un concentrado refractario de oro y plata

    Energy Technology Data Exchange (ETDEWEB)

    Coraonado, J. H.; Encinas, M. A.; Leyva, M. A.; Valenzuela, J. L.; Valenzuela, A.; Munive, G. T.

    2012-11-01

    In processing of precious metal ores with high pyrite content, refractory concentrates are obtained, which are difficult to process. A refractory gold and silver concentrate was leached with sodium cyanide. Results show low extraction percentages, being 34 % of gold and 40 % of silver. A roasting method to oxidize the concentrate was used, making it more susceptible to cyanidation, hence a more efficient way to extract precious metals. The variables include roasting temperature and roasting and cyanidation time. In addition, the hot calcine was added to the leaching solution at room temperature to analyze the effect on particle size and recovery. The best results, although not entirely satisfactory (50 % of gold and 61 % of silver) were obtained by roasting the concentrate for 4 h at 600 degree centigrade, followed by cyanidation for 20 h. The lime consumption to raise the pH to about 11.3 was increased markedly to 25 kg/m{sup 3}. (Author) 11 refs.

  18. Modelling Simulation and Comparison of Refractory Corrosion at RHI's Technology Center

    Science.gov (United States)

    Gregurek, Dean; Ressler, Angelika; Franzkowiak, Anna; Spanring, Alfred

    In order to determine the most suitable refractory products and improve the lining lifetime for the diverse furnaces used in the nonferrous metal industry, corrosion tests are performed at RHF's Technology Center. The practical facilities include the cup test, induction furnace, rotary kiln, and drip slag test described in this paper, which enable a comprehensive understanding of the chemo-thermal brick wear on a pilot scale. The corrosion trials are performed with actual slags generated during operations at a customer's plant. To determine the highest influencing wear parameter, every single test is combined with a detailed mineralogical investigation and thermochemical calculations performed using FactSage. Based on the results, tailored refractory solutions for the nonferrous metal industry can be provided in combination with trials conducted at the customer's site.

  19. Dramatic response to infliximab in refractory neurosarcoidosis

    Directory of Open Access Journals (Sweden)

    Chintamaneni Sreekanth

    2010-01-01

    Full Text Available Sarcoidosis is a systemic disease characterized by noncaseating granulomas in the involved organs. Neurologic manifestations involving the central and/or peripheral nervous system occur in about 5% of patients. Neurosarcoidosis is often refractory to conventional treatment and therefore more effective treatment options are needed. While the etiology of the disease is still unknown, there is now a better understanding of its pathogenesis on a molecular level. It is clear that tumor necrosis factor-α (TNFα plays a pivotal role in the development of the granulomas and it is believed to be a key cytokine involved in the pathogenesis of the disease. Taking advantage of this better understanding of disease pathogenesis, anti-TNFα agents are being increasingly used to treat refractory sarcoidosis. We report a patient with refractory neurosarcoidosis who showed dramatic improvement in the clinical and radiological manifestations following treatment with infliximab; he suffered a relapse upon discontinuation of the medication.

  20. Treatment of refractory neonatal seizures with topiramate.

    Science.gov (United States)

    Riesgo, Rudimar; Winckler, Maria Isabel; Ohlweiler, Lygia; Ranzan, Josiane; Becker, Michele; Salvador, Socrates; Magalhaes, Luiza; Ribeiro, Ricardo

    2012-12-01

    The objective of this study is to describe the usefulness of topiramate in refractory neonatal seizures. We reported the clinical off-label use of topiramate in three cases of refractory neonatal seizures of unclear origin with no response to conventional antiepileptic drugs. In all cases, the seizures were completely controlled with adding topiramate. All patients became seizure free during hospitalization and were followed by approximately 1 year after hospital discharge, with monotherapy with topiramate. The clinical off-label use of topiramate in neonatal seizures is still incipient. When searching publications in this matter, only one report was identified. Because of its efficacy for both seizures and neuroprotection, topiramate could be a useful choice in refractory neonatal seizures. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  1. Refractory Behaviors of Magnetite-Kaolin Bricks

    Science.gov (United States)

    Adeosun, S. O.; Akpan, E. I.; Gbenebor, O. P.; Taiwo, O. O.; Eke, I. J.

    2016-11-01

    In this work, the suitability of using kaolin-magnetite-plastic clay to produce refractory bricks has been experimentally explored. Thirty bricks of different compositions were produced and fired at 1200°C. The density, shrinkage moisture content, loss on ignition, porosity and permeability of the bricks were examined. Results show that the bricks remained stable during firing and thus possess good insulating characteristics. The highest (2.23 g/cm3) and lowest (2.00 g/cm3) bulk densities obtained in this study are higher than the highest bulk density reported for Al dross-filled refractories (1.23 g/cm3). The bricks also possessed very low effective moisture content (10-23%) and very high compression modulus (16-100 MPa) desirable in insulating refractory bricks with high resistance to abrasion.

  2. Design of Refractory Metal Life Test Heat Pipe and Calorimeter

    Science.gov (United States)

    Martin, J. J.; Reid, R. S.; Bragg-Sitton, S. M.

    2010-01-01

    Heat pipe life tests have seldom been conducted on a systematic basis. Typically, one or more heat pipes are built and tested for an extended period at a single temperature with simple condenser loading. Results are often reported describing the wall material, working fluid, test temperature, test duration, and occasionally the nature of any failure. Important information such as design details, processing procedures, material assay, power throughput, and radial power density are usually not mentioned. We propose to develop methods to generate carefully controlled data that conclusively establish heat pipe operating life with material-fluid combinations capable of extended operation. The test approach detailed in this Technical Publication will use 16 Mo-44.5%Re alloy/sodium heat pipe units that have an approximate12-in length and 5/8-in diameter. Two specific test series have been identified: (1) Long-term corrosion rates based on ASTM-G-68-80 (G-series) and (2) corrosion trends in a cross-correlation sequence at various temperatures and mass fluences based on a Fisher multifactor design (F-series). Evaluation of the heat pipe hardware will be performed in test chambers purged with an inert purified gas (helium or helium/argon mixture) at low pressure (10-100 torr) to provide thermal coupling between the heat pipe condenser and calorimeter. The final pressure will be selected to minimize the potential for voltage breakdown between the heat pipe and radio frequency (RF) induction coil (RF heating is currently the planned method of powering the heat pipes). The proposed calorimeter is constructed from a copper alloy and relies on a laminar flow water-coolant channel design to absorb and transport energy

  3. Office Procedures in Refractory Chronic Rhinosinusitis.

    Science.gov (United States)

    Thamboo, Andrew; Patel, Zara M

    2017-02-01

    Office procedures in chronic rhinosinusitis (CRS) can be considered before and after medical management, as well as before and after surgical management. This article focuses specifically on refractory CRS, meaning those patients who have failed medical and surgical management already. The options available in the management of refractory CRS depend on the personnel, equipment, and instrumentation available in the office setting; surgeon experience; and patient suitability and tolerability. This article provides readers with possible procedural options that can be done in their clinics with indications, patient selection, potential complications, and postoperative considerations. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Magnesite and chromium-magnesite refractories

    Energy Technology Data Exchange (ETDEWEB)

    Campos Loriz, D.

    1981-01-01

    The fifth part of the series, is concerned with a study on magnesite refractories, essential to the basic steelplant and starts with both traditional (natural carbonates and hydroxides) and recently-used (sea-water hydroxide) raw materials. Following a discussion on the fundamental system MgO-CaO-Si/sub 2/ consideration is given, among others, to baked, tarred and chemically-bonded refractories; their properties and use, ending with a brief examination of conventional and direct-bond chromium-magnesite materials.

  5. Double sequential defibrillation for refractory ventricular fibrillation.

    Science.gov (United States)

    El Tawil, Chady; Mrad, Sandra; Khishfe, Basem F

    2017-12-01

    A 54-year-old suffered from an out-of-hospital cardiac arrest. Compressions were started within minutes and the patient was in refractory ventricular fibrillation despite multiple asynchronized shocks and maximal doses of antiarrhythmic agents. Double sequential defibrillation was attempted with successful Return Of Spontaneous Circulation (ROSC) after a total of 61min of cardiac arrest. The patient was discharged home neurologically intact. Double sequential defibrillation could be a simple effective approach to patients with refractory ventricular fibrillation. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. 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.

  7. Characterization and testing of refractories for glass tank melters

    OpenAIRE

    Velez,M.; Karakus,M.; Reidmeyer,M. R.; Headrick,W. D.; Moore,R. E.

    2001-01-01

    Current and future research goals in our laboratories include the study of the attack of glass-contact refractories and of crown refractories in glass tank melters, under either air-gas or oxyfuel conditions. There is an emphasis on evaluation and characterization of critical parameters of commercial refractories such as microstructure, porosity and mechanical properties. A second focus is the evaluation of the performance of refractory alternatives to traditional crown and superstructure ref...

  8. Recent advances in silica-alumina refractory: A review

    OpenAIRE

    Sadik, Chaouki; El Amrani, Iz-Eddine; Albizane, Abderrahman

    2014-01-01

    In this article, the elaboration and the characterization of silica-alumina refractory have been reviewed. Refractory oxides encompass a broad range of unary, binary, and ternary ceramic compounds that can be used in structural, insulating, and other applications. This paper provides a historical perspective on the elaboration and the use of silica-alumina refractory, reviews applications for refractory oxides, describes typical processing routes, overviews fundamental structure–property rela...

  9. Recent advances in silica-alumina refractory: A review

    Directory of Open Access Journals (Sweden)

    Chaouki Sadik

    2014-06-01

    Full Text Available In this article, the elaboration and the characterization of silica-alumina refractory have been reviewed. Refractory oxides encompass a broad range of unary, binary, and ternary ceramic compounds that can be used in structural, insulating, and other applications. This paper provides a historical perspective on the elaboration and the use of silica-alumina refractory, reviews applications for refractory oxides, describes typical processing routes, overviews fundamental structure–property relations, and summarizes the properties of these materials.

  10. 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 ...

  11. Emerging therapeutics in refractory renal cell carcinoma.

    Science.gov (United States)

    Koshkin, Vadim S; Rini, Brian I

    2016-06-01

    Metastatic renal cell carcinoma (mRCC) has seen the introduction of numerous new treatments over the past decade. However, the efficacy of these therapies has plateaued, and new treatment options are needed for the majority of patients with mRCC whose disease inevitably progresses through one or more standard therapies ('refractory' mRCC). Recently approved agents in this space have shown great promise. This article reviews the evidence behind current management strategies for mRCC. After reviewing clinical trials that established current first-line therapies and agents used in the refractory setting, we address new ideas for the treatment of refractory disease including combination therapies and novel targeted agents. In particular, we focus on targeted immunotherapy in refractory mRCC. We conclude by considering future directions in combination treatments utilizing these novel agents. Numerous approaches have produced tangible benefits for the treatment of patients with mRCC. These include development of next generation VEGFR/TKIs, targeted immunotherapy agents, and the development of combined regimens. In particular, immunotherapy agents targeting the PD1/PD-L1 pathway have shown great promise with a robust survival advantage seen in patients treated with nivolumab. A tolerable side effect profile of immunotherapy agents makes them amenable for use in combination therapies and ongoing trials are addressing this question.

  12. Mapping strain fields induced in Zr-based bulk metallic glasses during in-situ nanoindentation by X-ray nanodiffraction

    Energy Technology Data Exchange (ETDEWEB)

    Gamcová, J.; Bednarčík, J.; Franz, H. [DESY, Notkestraße 85, Hamburg 22547 (Germany); Mohanty, G.; Wehrs, J.; Michler, J. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstraße 39, Thun 3602 (Switzerland); Michalik, Š. [Institute of Physics ASCR, Na Slovance 2, Praha 18221 (Czech Republic); Krywka, C. [HZG, Institut für Werkstoffforschung, Notkestraße 85, Hamburg 22547 (Germany); Breguet, J. M. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstraße 39, Thun 3602 (Switzerland); Alemnis GmbH, Feuerwerkerstraße 39, Thun 3602 (Switzerland)

    2016-01-18

    A pioneer in-situ synchrotron X-ray nanodiffraction approach for characterization and visualization of strain fields induced by nanoindentation in amorphous materials is introduced. In-situ nanoindentation experiments were performed in transmission mode using a monochromatic and highly focused sub-micron X-ray beam on 40 μm thick Zr-based bulk metallic glass under two loading conditions. Spatially resolved X-ray diffraction scans in the deformed volume of Zr-based bulk metallic glass covering an area of 40 × 40 μm{sup 2} beneath the pyramidal indenter revealed two-dimensional map of elastic strains. The largest value of compressive elastic strain calculated from diffraction data at 1 N load was −0.65%. The region of high elastic compressive strains (<−0.3%) is located beneath the indenter tip and has radius of 7 μm.

  13. Clinical Features of Refractory Ascites in Outpatients

    Directory of Open Access Journals (Sweden)

    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.

  14. Comprehensive Utilization of Iron and Phosphorus from High-Phosphorus Refractory Iron Ore

    Science.gov (United States)

    Sun, Yongsheng; Zhang, Qi; Han, Yuexin; Gao, Peng; Li, Guofeng

    2018-02-01

    An innovative process of coal-based reduction followed by magnetic separation and dephosphorization was developed to simultaneously recover iron and phosphorus from one typical high-phosphorus refractory iron ore. The experimental results showed that the iron minerals in iron ore were reduced to metallic iron during the coal-based reduction and the phosphorus was enriched in the metallic iron phase. The CaO-SiO2-FeO-Al2O3 slag system was used in the dephosphorization of metallic iron. A hot metal of 99.17% Fe and 0.10% P was produced with Fe recovery of 84.41%. Meanwhile, a dephosphorization slag of 5.72% P was obtained with P recovery of 67.23%. The contents of impurities in hot metal were very low, and it could be used as feedstock for steelmaking after a secondary refining. Phosphorus in the dephosphorization slag mainly existed in the form of a 5CaO·P2O5·SiO2 solid solution where the P2O5 content is 13.10%. At a slag particle size of 20.7 μm (90% passing), 94.54% of the P2O5 could be solubilized in citric acid, indicating the slag met the feedstock requirements in phosphate fertilizer production. Consequently, the proposed process achieved simultaneous Fe and P recovery, paving the way to comprehensive utilization of high-phosphorus refractory iron ore.

  15. Comprehensive Utilization of Iron and Phosphorus from High-Phosphorus Refractory Iron Ore

    Science.gov (United States)

    Sun, Yongsheng; Zhang, Qi; Han, Yuexin; Gao, Peng; Li, Guofeng

    2017-11-01

    An innovative process of coal-based reduction followed by magnetic separation and dephosphorization was developed to simultaneously recover iron and phosphorus from one typical high-phosphorus refractory iron ore. The experimental results showed that the iron minerals in iron ore were reduced to metallic iron during the coal-based reduction and the phosphorus was enriched in the metallic iron phase. The CaO-SiO2-FeO-Al2O3 slag system was used in the dephosphorization of metallic iron. A hot metal of 99.17% Fe and 0.10% P was produced with Fe recovery of 84.41%. Meanwhile, a dephosphorization slag of 5.72% P was obtained with P recovery of 67.23%. The contents of impurities in hot metal were very low, and it could be used as feedstock for steelmaking after a secondary refining. Phosphorus in the dephosphorization slag mainly existed in the form of a 5CaO·P2O5·SiO2 solid solution where the P2O5 content is 13.10%. At a slag particle size of 20.7 μm (90% passing), 94.54% of the P2O5 could be solubilized in citric acid, indicating the slag met the feedstock requirements in phosphate fertilizer production. Consequently, the proposed process achieved simultaneous Fe and P recovery, paving the way to comprehensive utilization of high-phosphorus refractory iron ore.

  16. Characterization and testing of refractories for glass tank melters

    Directory of Open Access Journals (Sweden)

    Velez M.

    2001-01-01

    Full Text Available Current and future research goals in our laboratories include the study of the attack of glass-contact refractories and of crown refractories in glass tank melters, under either air-gas or oxyfuel conditions. There is an emphasis on evaluation and characterization of critical parameters of commercial refractories such as microstructure, porosity and mechanical properties. A second focus is the evaluation of the performance of refractory alternatives to traditional crown and superstructure refractories including their physical aspects, crown design, and joint quality.

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

    Science.gov (United States)

    Holtkamp, Martin

    2018-01-24

    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

  18. Acupuncture for refractory epilepsy: role of thalamus.

    Science.gov (United States)

    Chen, Shuping; Wang, Shubin; Rong, Peijing; Liu, Junling; Zhang, Hongqi; Zhang, Jianliang

    2014-01-01

    Neurostimulation procedures like vagus nerve stimulation (VNS) and deep brain stimulation have been used to treat refractory epilepsy and other neurological disorders. While holding promise, they are invasive interventions with serious complications and adverse effects. Moreover, their efficacies are modest with less seizure free. Acupuncture is a simple, safe, and effective traditional healing modality for a wide range of diseases including pain and epilepsy. Thalamus takes critical role in sensory transmission and is highly involved in epilepsy genesis particularly the absence epilepsy. Considering thalamus serves as a convergent structure for both acupuncture and VNS and the thalamic neuronal activities can be modulated by acupuncture, we propose that acupuncture could be a promising therapy or at least a screening tool to select suitable candidates for those invasive modalities in the management of refractory epilepsy.

  19. Acupuncture for Refractory Epilepsy: Role of Thalamus

    Directory of Open Access Journals (Sweden)

    Shuping Chen

    2014-01-01

    Full Text Available Neurostimulation procedures like vagus nerve stimulation (VNS and deep brain stimulation have been used to treat refractory epilepsy and other neurological disorders. While holding promise, they are invasive interventions with serious complications and adverse effects. Moreover, their efficacies are modest with less seizure free. Acupuncture is a simple, safe, and effective traditional healing modality for a wide range of diseases including pain and epilepsy. Thalamus takes critical role in sensory transmission and is highly involved in epilepsy genesis particularly the absence epilepsy. Considering thalamus serves as a convergent structure for both acupuncture and VNS and the thalamic neuronal activities can be modulated by acupuncture, we propose that acupuncture could be a promising therapy or at least a screening tool to select suitable candidates for those invasive modalities in the management of refractory epilepsy.

  20. Deoxyspergualin in relapsing and refractory Wegener's granulomatosis

    DEFF Research Database (Denmark)

    Flossmann, O; Baslund, B; Bruchfeld, A

    2008-01-01

    OBJECTIVES: Conventional therapy of Wegener's granulomatosis with cyclophosphamide and corticosteroids is limited by incomplete remissions and a high relapse rate. The efficacy and safety of an alternative immunosuppressive drug, deoxyspergualin, was evaluated in patients with relapsing...... or refractory disease. METHODS: A prospective, international, multicentre, single-limb, open-label study. Entry required active Wegener's granulomatosis with a Birmingham vasculitis activity score (BVAS) > or =4 and previous therapy with cyclophosphamide or methotrexate. Immunosuppressive drugs were withdrawn......-threatening (> or = grade 3) treatment-related adverse events occurred in 24 (53%) patients mostly due to leucopaenias. CONCLUSIONS: Deoxyspergualin achieved a high rate of disease remission and permitted prednisolone reduction in refractory or relapsing Wegener's granulomatosis. Adverse events were common but rarely led...

  1. Intravenous immunoglobulin therapy for refractory recurrent pericarditis.

    Science.gov (United States)

    del Fresno, M Rosa; Peralta, Julio E; Granados, Miguel Ángel; Enríquez, Eugenia; Domínguez-Pinilla, Nerea; de Inocencio, Jaime

    2014-11-01

    Recurrent pericarditis is a troublesome complication of idiopathic acute pericarditis and occurs more frequently in pediatric patients after cardiac surgery (postpericardiotomy syndrome). Conventional treatment with nonsteroidal antiinflammatory drugs, corticosteroids, and colchicine is not always effective or may cause serious adverse effects. There is no consensus, however, on how to proceed in those patients whose disease is refractory to conventional therapy. In such cases, human intravenous immunoglobulin, immunosuppressive drugs, and biological agents have been used. In this report we describe 2 patients with refractory recurrent pericarditis after cardiac surgery who were successfully treated with 3 and 5 monthly high-dose (2 g/kg) intravenous immunoglobulin until resolution of the effusion. Our experience supports the effectiveness and safety of this therapy. Copyright © 2014 by the American Academy of Pediatrics.

  2. Management of refractory ischemic priapism: current perspectives

    Directory of Open Access Journals (Sweden)

    Capece M

    2017-08-01

    Full Text Available Marco Capece,1 Arianna Gillo,2 Andrea Cocci,3 Giulio Garaffa,1 Massimiliano Timpano,4 Marco Falcone4 1The Institute of Urology, University College of London Hospital (UCLH, London, UK; 2Department of Urology, “Umberto Parini” Hospital, Aosta, 3Department of Urology, Careggi Hospital, Firenze, 4Department of Urology, University of Turin, Città della Salute e della Scienza, Turin, Italy Objectives: The aim of the present manuscript is to review the current literature on priapism, focusing on the state-of-the-art knowledge of both the diagnosis and the treatment of the refractory ischemic priapism (IP.Methods: Pubmed and EMBASE search engines were used to search for words “priapism”, “refractory priapism”, “penile prosthesis”, “diagnosis priapism”, “priapism treatment”, “penile fibrosis”, “priapism therapy”. All the studies were carefully examined by the authors and then included in the review.Results: First-line treatment involves ejaculation, physical exercise and cold shower followed by corporal blood aspiration and injection of α-adrenoceptor agonists. Subsequently, a distal or proximal shunt may be considered. If none of the treatment is effective or the priapism episode lasts >48 hours penile prosthesis implantation could be the only option to solve the priapism and treat the ongoing erectile dysfunction.Conclusion: The management of IP is to achieve detumescence of persistent penile erection and to preserve erectile function after resolution of the priapic episode. On the other hand, penile fibrosis and following shortening should be prevented. Early penile prosthesis implantation in patients with refractory IP is able to solve both the priapic episode and prevent the otherwise certain penile shortening. Penile prosthesis implantation is the actual gold standard of care in cases of refractory IP. Keywords: priapism, ischemic priapism, penile fibrosis, penile prosthesis, shunt 

  3. Acupuncture for Refractory Epilepsy: Role of Thalamus

    OpenAIRE

    Chen, Shuping; Wang, Shubin; Rong, Peijing; Liu, Junling; Zhang, Hongqi; Zhang, Jianliang

    2014-01-01

    Neurostimulation procedures like vagus nerve stimulation (VNS) and deep brain stimulation have been used to treat refractory epilepsy and other neurological disorders. While holding promise, they are invasive interventions with serious complications and adverse effects. Moreover, their efficacies are modest with less seizure free. Acupuncture is a simple, safe, and effective traditional healing modality for a wide range of diseases including pain and epilepsy. Thalamus takes critical role in ...

  4. Medical image of the week: refractory dyspnea

    OpenAIRE

    Malo J; Reyes N; Rischard F

    2012-01-01

    A 61 year old man with an extensive smoking history and emphysema was referred for evaluation of dyspnea refractory to standard therapy. He was diagnosed with a pulmonary embolism 5 months prior to presentation and has been on warfarin since that time. Review of the patient’s CT scan performed prior to the visit demonstrated dilated main; right; and left pulmonary arteries (Figure 1). Also visualized was an eccentrically located thrombus with areas of calcification and central recanalization...

  5. How I treat refractory thrombotic thrombocytopenic purpura

    Science.gov (United States)

    Sayani, Farzana A.

    2015-01-01

    Acquired thrombotic thrombocytopenic purpura (TTP) is characterized by thrombocytopenia and microangiopathic hemolytic anemia (MAHA) without an obvious cause, and may include fever, mild renal failure, and neurologic deficits. It is characterized by a deficiency of the von Willebrand factor (VWF) cleaving enzyme, ADAMTS13 (a disintegrin and metalloproteinase, with a thrombospondin type 1 motif, member 13), resulting in formation of microthrombi in the high sheer environment of the microvasculature. This causes microvascular occlusion, MAHA, and organ ischemia. Diagnosis is based on the presence of clinical symptoms, laboratory aberrations consistent with MAHA, decreased ADAMTS13 activity, and possibly presence of anti-ADAMTS13 autoantibodies. Upfront treatment of acute TTP includes plasma exchange and corticosteroids. A significant number of patients are refractory to this treatment and will require further interventions. There are limited data and consensus on the management of the refractory TTP patient. Management involves simultaneously ruling out other causes of thrombocytopenia and MAHA, while also considering other treatments. In this article, we describe our management of the patient with refractory TTP, and discuss use of rituximab, increased plasma exchange, splenectomy, and immunosuppressive options, including cyclophosphamide, vincristine, and cyclosporine. We also review recent evidence for the potential roles of bortezomib and N-acetylcysteine, and explore new therapeutic approaches, including recombinant ADAMTS13 and anti-VWF therapy. PMID:25784681

  6. Refractory hematemesis caused by haemoductal pancreatitis

    Directory of Open Access Journals (Sweden)

    Chandrasekharan Rajasekharan

    2012-04-01

    Full Text Available We report a case of a 48-year-old female, who presented with refractory haemetemesis. Her oesophago-gastroduodenoscopy showed only a healing ulcer but profuse bleeding was seen from duodenum. In spite of a negative oesophago-gastroduodenoscopy she was bleeding profusely with haemodynamic decompensation. Doppler coeliac trunk showed a suprapancreatic cystic lesion with yin-yang pattern of blood flow confirming a pseudo aneurysm involving the superior and inferior pancreatioduodenal arterial arcade using digital subtraction angiography. The conversion of a pancreatic pseudo cyst into a pseudo aneurysm is a potential lethal complication because, when rupture occurs, mortality rises up to 40%.She was diagnosed to have pancreatic pseudocyst, psedoaneurysm and haemosuccus pancreaticus with wirsungorrhagia and was offered arterial embolization following which she improved. Patients with chronic calcificpancratitis (CCP could remain silent and can present with normal amylase and lipase. Complications such as pseudocysts or pseudoaneurysms can be asymptomatic. The pancreas should be considered a possible site of hemorrhage in CCP in cases of refractory upper gasrtrointestinal haemorrhage. We highlight the importance of looking for causes other than bleeding duodenal/gastic ulcer/oesophageal varices in case of a refractory hametemeis giving the patient option of a nonsurgical modality of treatment and it’s reduced risks.The effectiveness of embolistion for bleeding psuedoaneurysms is emphasized.

  7. Angiotensin II in Refractory Septic Shock.

    Science.gov (United States)

    Antonucci, Elio; Gleeson, Patrick J; Annoni, Filippo; Agosta, Sara; Orlando, Sergio; Taccone, Fabio Silvio; Velissaris, Dimitrios; Scolletta, Sabino

    2017-05-01

    Refractory septic shock is defined as persistently low mean arterial blood pressure despite volume resuscitation and titrated vasopressors/inotropes in patients with a proven or suspected infection and concomitant organ dysfunction. Its management typically requires high doses of catecholamines, which can induce significant adverse effects such as ischemia and arrhythmias. Angiotensin II (Ang II), a key product of the renin-angiotensin-aldosterone system, is a vasopressor agent that could be used in conjunction with other vasopressors to stabilize critically ill patients during refractory septic shock, and reduce catecholamine requirements. However, very few clinical data are available to support Ang II administration in this setting. Here, we review the current literature on this topic to better understand the role of Ang II administration during refractory septic shock, differentiating experimental from clinical studies. We also consider the potential role of exogenous Ang II administration in specific organ dysfunction and possible pitfalls with Ang II in sepsis. Various issues remain unresolved and future studies should investigate important topics such as: the optimal dose and timing of Ang II administration, a comparison between Ang II and the other vasopressors (epinephrine; vasopressin), and Ang II effects on microcirculation.

  8. New sol–gel refractory coatings on chemically-bonded sand cores for foundry applications to improve casting surface quality

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Poulsen, T.; Stage, R.K.

    2011-01-01

    Foundry refractory coatings protect bonded sand cores and moulds from producing defective castings during the casting process by providing a barrier between the core and the liquid metal. In this study, new sol–gel refractory coating on phenolic urethane cold box (PUCB) core was examined. The coa......Foundry refractory coatings protect bonded sand cores and moulds from producing defective castings during the casting process by providing a barrier between the core and the liquid metal. In this study, new sol–gel refractory coating on phenolic urethane cold box (PUCB) core was examined...... were produced with sol-gel coated and uncoated cores and the results were related to the coating properties. The casting results were also compared with castings made with cores coated with commercial alcohol-based and water-based foundry coatings. The analyses show that castings produced with sol–gel...... coated cores have better surface quality than those from uncoated cores and comparable surface quality with the commercial coatings. Therefore, the new sol–gel coating has a potential application in the foundry industry for improving the surface finish of castings thereby reducing the cost of fettling...

  9. Comprehensive Creep and Thermophysical Performance of Refractory Materials

    Energy Technology Data Exchange (ETDEWEB)

    Ferber, M.K.; Wereszczak, A.; Hemrick, J.A.

    2006-06-29

    Furnace designers and refractory engineers recognize that optimized furnace superstructure design and refractory selection are needed as glass production furnaces are continually striving toward greater output and efficiencies. Harsher operating conditions test refractories to the limit, while changing production technology (such as the conversion to oxy-fuel from traditional air-fuel firing) can alter the way the materials perform [1-3]. Refractories for both oxy- and air-fuel fired furnace superstructures (see Fig. 1) are subjected to high temperatures that may cause them to creep excessively or subside during service if the refractory material is not creep resistant, or if it is subjected to high stress, or both. Furnace designers can ensure that superstructure structural integrity is maintained if the creep behavior of the refractory material is well understood and well represented by appropriate engineering creep models. Several issues limit the abilities of furnace designers to (1) choose the optimum refractory for their applications, (2) optimize the engineering design, or (3) predict the service mechanical integrity of their furnace superstructures. Published engineering creep data are essentially nonexistent for almost all commercially available refractories used for glass furnace superstructures. The limited data that do exist are supplied by the various refractory suppliers. Unfortunately, the suppliers generally have different ways of conducting their mechanical testing, and they interpret and report their data differently. This inconsistency makes it hard for furnace designers to draw fair comparisons between competing grades of candidate refractories. Furthermore, the refractory suppliers' data are often not available in a form that can be readily used for furnace design or for the prediction and design of long-term structural integrity of furnace superstructures. As a consequence, the U.S. Department of Energy (DOE) Industrial Technology Program

  10. 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.

  11. Current Management of Refractory Germ Cell Tumors and Future Directions.

    Science.gov (United States)

    Allen, J Clayton; Kirschner, Austin; Scarpato, Kristen R; Morgans, Alicia K

    2017-02-01

    We review current management strategies for patients with relapsed and refractory germ cell tumors (GCTs), defined as relapsed or persistent disease following at least one line of cisplatin-based chemotherapy. Additionally, we discuss future directions in the management of these patients. Recent studies involving targeted therapies have been disappointing. Nevertheless, studies of the management of refractory germ cell cancer are ongoing, with a focus on optimal utilization of high-dose chemotherapy and autologous stem cell transplant, as well as the role of immune checkpoint inhibitors in refractory germ cell tumors. Studies aiming to identify those patients who may benefit from more intensive treatment up front to prevent the development of refractory disease are also in progress. Testicular germ cell tumors are among the most curable of all solid tumor malignancies, with cure being possible even in the refractory, metastatic setting. Treatment of refractory disease remains a challenging clinical scenario, but potentially practice changing studies are ongoing.

  12. SENSOR-BASED SORTING OF SPENT REFRACTORY BRICKS

    OpenAIRE

    Knapp, Henning; Horckmans, Liesbeth; Bouillot, Frédérique; Fricke-Begemann, Cord; Connemann, Sven; Makowe, Joachim; Ducastel, Antoine; Stark, Alexander

    2016-01-01

    Refractory materials are essential for all high-temperature applications in industry. Depending on the position in the furnace and specific process requirements, refractories are produced from several raw materials, such as dolomite, magnesite, bauxite, graphite or chromite. Most of these raw materials are not rare but strict quality requirements limit the producers of refractories to only a few deposits in the world. Thus, raw material supply is a critical factor for the production of refrac...

  13. Sensor-based identification of spent Refractory Bricks

    OpenAIRE

    Knapp, Henning; Horckmans, L.; Fricke-Begemann, Cord; Makowe, Joachim; Ducastel, A.; Stark, Alexander; Bouillot, F.

    2015-01-01

    Refractory bricks are essential for high-temperature applications in various industries. The fabrication of most of our daily life products consumes a certain amount of refractories. Although essential, they are often not perceived so by the public. Depending on their specific application and the position in the furnace, different types of refractories are necessary. The different types consist of a small number of naturally occurring high quality raw materials, such as dolomite, magnesite, b...

  14. Properties of Refractory Concrete in Tension and Compression

    Science.gov (United States)

    Sampson, Jeffrey

    2009-01-01

    Refractory concrete on the LC-39A Flame Deflector has been damaged during multiple Space Shuttle launches (e.g. STS-124, STS-126, STS-119, and STS-125, STS-127). These events have prompted a better understanding of the system via an analytical model of the Flame Deflector assembly to include the Fondu Fyre refractory concrete. This model requires test data inputs of the refractory concrete's mechanical properties, which include stress versus strain curves in tension and compression, modulus of elasticity, and Poisson's ratio. Sections of Fondu Fyre refractory concrete removed from the LC-39A Flame Deflector were provided for this testing.

  15. Refractory Coated/Lined Low Density Structures Project

    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...

  16. Ketogenic diet therapy is effective in encephalitis with refractory seizures.

    Science.gov (United States)

    Matsuzono, Kosuke; Kurata, Tomoko; Deguchi, Shoko; Yamashita, Toru; Deguchi, Kentaro; Abe, Koji

    2014-10-01

    Although ketogenic diet therapy is effective in refractory seizures in childhood, its effect on adult encephalitis with similar refractory seizures and prolonged encephalopathy has not been well reported. We report here a case of a 22-year-old man with acute encephalitis with refractory repetitive partial seizures (AERRPS). Partial seizures of the face developed to repeated generalized convulsions, which were refractory against anti-epileptic drugs and a high dose of propofol. After struggling for 9 months, he dramatically recovered after ketogenic diet therapy. Ketogenic diet therapy may be an important tool to help cure AERRPS.

  17. 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.

  18. Launch Pad Flame Trench Refractory Materials

    Science.gov (United States)

    Calle, Luz M.; Hintze, Paul E.; Parlier, Christopher R.; Bucherl, Cori; Sampson, Jeffrey W.; Curran, Jerome P.; Kolody, Mark; Perusich, Steve; Whitten, Mary

    2010-01-01

    The launch complexes at NASA's John F. Kennedy Space Center (KSC) are critical support facilities for the successful launch of space-based vehicles. These facilities include a flame trench that bisects the pad at ground level. This trench includes a flame deflector system that consists of an inverted, V-shaped steel structure covered with a high temperature concrete material five inches thick that extends across the center of the flame trench. One side of the "V11 receives and deflects the flames from the orbiter main engines; the opposite side deflects the flames from the solid rocket boosters. There are also two movable deflectors at the top of the trench to provide additional protection to shuttle hardware from the solid rocket booster flames. These facilities are over 40 years old and are experiencing constant deterioration from launch heat/blast effects and environmental exposure. The refractory material currently used in launch pad flame deflectors has become susceptible to failure, resulting in large sections of the material breaking away from the steel base structure and creating high-speed projectiles during launch. These projectiles jeopardize the safety of the launch complex, crew, and vehicle. Post launch inspections have revealed that the number and frequency of repairs, as well as the area and size of the damage, is increasing with the number of launches. The Space Shuttle Program has accepted the extensive ground processing costs for post launch repair of damaged areas and investigations of future launch related failures for the remainder of the program. There currently are no long term solutions available for Constellation Program ground operations to address the poor performance and subsequent failures of the refractory materials. Over the last three years, significant liberation of refractory material in the flame trench and fire bricks along the adjacent trench walls following Space Shuttle launches have resulted in extensive investigations of

  19. 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.

  20. Refractory reverse amblyopia with atropine penalization

    Directory of Open Access Journals (Sweden)

    Preeti Ajit Patil

    2010-01-01

    Full Text Available Pharmacological penalization with atropine has been shown to be equally effective as conventional occlusion therapy in the treatment of amblyopia in children. Reverse amblyopia of the sound eye with atropine penalization has been reported before, but is more common in cases where the effect is augmented with optical penalization and is mostly reversible. We report a case of reverse amblyopia with atropine penalization, in a 4-year-old girl, which was refractory to treatment. This report highlights the need for strict monitoring of the vision in the sound eye and regular follow-up in children undergoing amblyopia treatment.

  1. Medical image of the week: refractory dyspnea

    Directory of Open Access Journals (Sweden)

    Malo J

    2012-12-01

    Full Text Available A 61 year old man with an extensive smoking history and emphysema was referred for evaluation of dyspnea refractory to standard therapy. He was diagnosed with a pulmonary embolism 5 months prior to presentation and has been on warfarin since that time. Review of the patient’s CT scan performed prior to the visit demonstrated dilated main; right; and left pulmonary arteries (Figure 1. Also visualized was an eccentrically located thrombus with areas of calcification and central recanalization. Echocardiography confirmed the presence of elevated pulmonary pressures consistent with a diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH. Medical therapy and a referral for pulmonary artery endarterectomy are being considered.

  2. Assessment of Sub-Micron Particles by Exploiting Charge Differences with Dielectrophoresis

    Directory of Open Access Journals (Sweden)

    Maria F. Romero-Creel

    2017-08-01

    Full Text Available The analysis, separation, and enrichment of submicron particles are critical steps in many applications, ranging from bio-sensing to disease diagnostics. Microfluidic electrokinetic techniques, such as dielectrophoresis (DEP have proved to be excellent platforms for assessment of submicron particles. DEP is the motion of polarizable particles under the presence of a non-uniform electric field. In this work, the polarization and dielectrophoretic behavior of polystyrene particles with diameters ranging for 100 nm to 1 μm were studied employing microchannels for insulator based DEP (iDEP and low frequency (<1000 Hz AC and DC electric potentials. In particular, the effects of particle surface charge, in terms of magnitude and type of functionalization, were examined. It was found that the magnitude of particle surface charge has a significant impact on the polarization and dielectrophoretic response of the particles, allowing for successful particle assessment. Traditionally, charge differences are exploited employing electrophoretic techniques and particle separation is achieved by differential migration. The present study demonstrates that differences in the particle’s surface charge can also be exploited by means of iDEP; and that distinct types of nanoparticles can be identified by their polarization and dielectrophoretic behavior. These findings open the possibility for iDEP to be employed as a technique for the analysis of submicron biological particles, where subtle differences in surface charge could allow for rapid particle identification and separation.

  3. A solvent-shrinkage method for producing polymeric microsieves with sub-micron size pores

    NARCIS (Netherlands)

    Vriezekolk, Erik; Kemperman, Antonius J.B.; Girones nogue, Miriam; de Vos, Wiebe Matthijs; Nijmeijer, Dorothea C.

    2013-01-01

    This paper presents a thorough investigation of a simple method to decrease the dimensions of polymeric microsieves. Pore sizes of microsieves are usually in the micrometer scale, but need to be reduced to below 1 µm to make the microsieves attractive for aqueous filtration applications. In this

  4. Simulation of monolithic active pixels in deep sub-micron technologies

    CERN Document Server

    Manolopoulos, S; Turchetta, R

    2002-01-01

    The use of monolithic active pixels (MAPS) has quickly spread in a number of scientific fields ranging from imaging to high-energy particle physics applications. The success of MAPS is due to a number of reasons, for example their low power consumption, fast readout, high spatial resolution and low cost. The latter reflects the use of standard CMOS processes for fabrication. In this paper, the performance of MAPS designed in 0.25 mu m technology will be modelled by means of TCAD device simulation software. The dependence of the device performance on parameters that affect the detection of minimum ionising particles (MIP) will be studied aiming at the optimisation of the detector performance. More specifically, the simulations will focus on the influence of the epitaxial layer thickness on the amount of collected charge, that defines the signal and the cluster size, that affects the spatial resolution.

  5. Preparation of chitosan-TPP sub-micron particles: Critical evaluation and derived recommendations.

    Science.gov (United States)

    Rázga, Filip; Vnuková, Dominika; Némethová, Veronika; Mazancová, Petra; Lacík, Igor

    2016-10-20

    The controlled preparation of chitosan particles is far from being trivial due to a considerable number of experimental parameters. For chitosan-tripolyphosphate (TPP) particles we evaluate the impact of chemical (type of chitosan, concentration, chitosan to TPP ratio, pH, ionic strength) and process factors (dialysis, stirring rate, rate of TPP addition, temperature, needle diameter) on the size and colloidal stability. The particles were prepared at pH=6.0 at which chitosan adopts the coiled conformation that is discussed as the dominant factor in controlling the stoichiometry of crosslinking reaction shifted towards TPP. These conditions result in identical particle size around 400nm and zeta potential around 22mV. The colloidal stability evaluated 24 hours after preparation depends on the amount of TPP during crosslinking. Under the same conditions, the colloidal stability up to 1 month is demonstrated. Several recommendations are provided to increase the control over formation of chitosan-TPP particles. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Trapping ultracold atoms in a sub-micron-period triangular magnetic lattice

    Science.gov (United States)

    Wang, Y.; Tran, T.; Surendran, P.; Herrera, I.; Balcytis, A.; Nissen, D.; Albrecht, M.; Sidorov, A.; Hannaford, P.

    2017-07-01

    We report the trapping of ultracold 87Rb atoms in a 0.7-μ m-period two-dimensional triangular magnetic lattice on an atom chip. The magnetic lattice is created by a lithographically patterned magnetic Co/Pd multilayer film plus bias fields. Rubidium atoms in the |F =1 , mF=-1 > low-field seeking state are trapped at estimated distances down to about 100 nm from the chip surface and with calculated mean trapping frequencies up to about 800 kHz . The measured lifetimes of the atoms trapped in the magnetic lattice are in the range 0.4-1.7 ms , depending on distance from the chip surface. Model calculations suggest the trap lifetimes are currently limited mainly by losses due to one-dimensional thermal evaporation following loading of the atoms from the Z -wire trap into the very tight magnetic lattice traps, rather than by fundamental loss processes such as surface interactions, three-body recombination, or spin flips due to Johnson magnetic noise. The trapping of atoms in a 0.7 -μ m -period magnetic lattice represents a significant step toward using magnetic lattices for quantum tunneling experiments and to simulate condensed matter and many-body phenomena in nontrivial lattice geometries.

  7. Induced magnetoresistance in semiconductor devices due to single sub-micron magnetic barriers

    Science.gov (United States)

    Kubrak, V.; Rahman, F.; Overend, N.; Gallagher, B. L.; Main, P. C.; Boeck, J. de; Behest, M.; Marrows, C. H.; Howson, M. A.

    1998-12-01

    We investigate the magnetoresistance induced in a near-surface two-dimensional electron gas by the fringe field of a thin ferromagnetic line on the surface of the device. From the measured magnetoresistance, we deduce the hysteretic properties of the magnetic line, using the semiconductor device as a nanomagnetometer.

  8. Multidisciplinary Approach to the Science and Technology of Sub-Micron Electronics.

    Science.gov (United States)

    1987-03-10

    overlap with the continuum are unique to the quantum well structures. A paper describing our findings has been submitted for publication. Regarding...Grant ARO DAAG 29-83-K-0131 during the period 7/1/85-12/31/85 1. " Fibonacci GaAs-AlAs Superlattices", R. Clarke, R. Merlin, K. Bajema, F.-Y Juang and P.K...pursued: experiments on new quasiperiodic superlattices and studies of quantum-well structures. In the quasiperiodic ( Fibonacci ) superlattices we have

  9. Simulation of hurricane response to suppression of warm rain by sub-micron aerosols

    Directory of Open Access Journals (Sweden)

    D. Rosenfeld

    2007-07-01

    Full Text Available The feasibility of hurricane modification was investigated for hurricane Katrina using the Weather Research and Forecasting Model (WRF. The possible impact of seeding of clouds with submicron cloud condensation nuclei (CCN on hurricane structure and intensity as measured by nearly halving of the area covered by hurricane force winds was simulated by "turning–off" warm rain formation in the clouds at Katrina's periphery (where wind speeds were less than 22 m s−1. This simplification of the simulation of aerosol effects is aimed at evaluating the largest possible response. This resulted in the weakening of the hurricane surface winds compared to the "non-seeded" simulated storm during the first 24 h within the entire tropical cyclone (TC area compared to a control simulation without warm rain suppression. Later, the seeding-induced evaporative cooling at the TC periphery led to a shrinking of the eye and hence to some increase in the wind within the small central area of the TC. Yet, the overall strength of the hurricane, as defined by the area covered by hurricane force winds, decreased in response to the suppressed warm rain at the periphery, as measured by a 25% reduction in the radius of hurricane force winds. In a simulation with warm rain suppression throughout the hurricane, the radius of the hurricane force winds was reduced by more than 42%, and although the diameter of the eye shrunk even further the maximum winds weakened. This shows that the main mechanism by which suppressing warm rain weakens the TC is the low level evaporative cooling of the un-precipitated cloud drops and the added cooling due to melting of precipitation that falls from above.

  10. Sub-micron-sized delafossite CuCrO2 with different morphologies ...

    Indian Academy of Sciences (India)

    Currently, copper chromium oxide crystallizing in delafossite structure attracts huge research interest due to its versatile applications arising from its layered structure. In this work, delafossite CuCrO 2 was synthesized by sol–gel method from their respective hydrated nitrate salts with citric acid as a chelating agent.

  11. Penetration of sub-micron aerosol droplets in composite cylindrical filtration elements

    NARCIS (Netherlands)

    Geurts, Bernardus J.; Pratte, Pascal; Stolz, S.; Stabbert, Regina; Poux, Valerie; Nordlund, Markus; Winkelmann, Christoph

    Advection–diffusion transport of aerosol droplets in composite cylindrical filtration elements is analyzed and compared to experimental data. The penetration, characterizing the fraction of droplets that passes through the pores of a filtration element, is quantified for a range of flow rates. The

  12. Deviation from threshold model in ultrafast laser ablation of graphene at sub-micron scale

    Energy Technology Data Exchange (ETDEWEB)

    Gil-Villalba, A.; Xie, C.; Salut, R.; Furfaro, L.; Giust, R.; Jacquot, M.; Lacourt, P. A.; Dudley, J. M.; Courvoisier, F., E-mail: francois.courvoisier@femto-st.fr [Institut FEMTO-ST, UMR 6174 CNRS, Universite de Bourgogne Franche-Comte, 25030 Besançon Cedex (France)

    2015-08-10

    We investigate a method to measure ultrafast laser ablation threshold with respect to spot size. We use structured complex beams to generate a pattern of craters in CVD graphene with a single laser pulse. A direct comparison between beam profile and SEM characterization allows us to determine the dependence of ablation probability on spot-size, for crater diameters ranging between 700 nm and 2.5 μm. We report a drastic decrease of ablation probability when the crater diameter is below 1 μm which we interpret in terms of free-carrier diffusion.

  13. Preparation and characterization of sub-micron dispersions of sand in ethylene glycol-water mixture

    OpenAIRE

    Manikandan,S.; Karthikeyan, N.; M Silambarasan; K. S. Suganthi; Rajan, K. S.

    2012-01-01

    Experiments were carried out on the preparation and characterization of dispersions of sand in ethylene glycol-water (50-50%) mixture. The dispersions were prepared by stirred bead milling of 20-30 µm sand (in water) followed by dilution with water and ethylene glycol. The influence of temperature (31-45 ºC), particle concentration (< 2 vol %) and ultrasonication on the viscosity of sand-ethylene glycol-water dispersions was studied. The thermal conductivity of dispersions as a function of pa...

  14. White light generation using photonic crystal fiber with sub-micron circular lattice

    Science.gov (United States)

    Saghaei, Hamed; Ghanbari, Ashkan

    2017-08-01

    In this paper, we study a photonic crystal fiber (PCF) with circular lattice and engineer linear and nonlinear parameters by varying the diameter of air-holes. It helps us obtain low and high zero dispersion wavelengths in the visible and nearinfrared regions. We numerically demonstrate that by launching 100 fs input pulses of 1, 2, and 5 kW peak powers with center wavelength of 532 nm from an unamplified Ti:sapphire laser into a 100 mm length of the engineered PCF, supercontinua as wide as 290, 440 and 830 nm can be obtained, respectively. The spectral broadening is due to the combined action of self-phase modulation, stimulated Raman scattering and parametric four-wave-mixing generation of the pump pulses. The third and the widest spectrum covers the entire visible range and a part of near infrared region making it a suitable source for both white light applications and optical coherence tomography to measure retinal oxygen metabolic response to systemic oxygenation.

  15. Laser forming for sub-micron adjustment: with application to optical fiber assembly

    NARCIS (Netherlands)

    Folkersma, Ger

    2015-01-01

    Laser forming is a method to deform a material by controlled local laser heating. In combination with a dedicated actuator topology, those deformations can be used for high precision alignment of components. This thesis applies this method to the alignment of optical fibers with respect to the

  16. OpenStage: a low-cost motorized microscope stage with sub-micron positioning accuracy.

    Directory of Open Access Journals (Sweden)

    Robert A A Campbell

    Full Text Available Recent progress in intracellular calcium sensors and other fluorophores has promoted the widespread adoption of functional optical imaging in the life sciences. Home-built multiphoton microscopes are easy to build, highly customizable, and cost effective. For many imaging applications a 3-axis motorized stage is critical, but commercially available motorization hardware (motorized translators, controller boxes, etc are often very expensive. Furthermore, the firmware on commercial motor controllers cannot easily be altered and is not usually designed with a microscope stage in mind. Here we describe an open-source motorization solution that is simple to construct, yet far cheaper and more customizable than commercial offerings. The cost of the controller and motorization hardware are under $1000. Hardware costs are kept low by replacing linear actuators with high quality stepper motors. Electronics are assembled from commonly available hobby components, which are easy to work with. Here we describe assembly of the system and quantify the positioning accuracy of all three axes. We obtain positioning repeatability of the order of 1 μm in X/Y and 0.1 μm in Z. A hand-held control-pad allows the user to direct stage motion precisely over a wide range of speeds (10(-1 to 10(2 μm·s(-1, rapidly store and return to different locations, and execute "jumps" of a fixed size. In addition, the system can be controlled from a PC serial port. Our "OpenStage" controller is sufficiently flexible that it could be used to drive other devices, such as micro-manipulators, with minimal modifications.

  17. OpenStage: a low-cost motorized microscope stage with sub-micron positioning accuracy.

    Science.gov (United States)

    Campbell, Robert A A; Eifert, Robert W; Turner, Glenn C

    2014-01-01

    Recent progress in intracellular calcium sensors and other fluorophores has promoted the widespread adoption of functional optical imaging in the life sciences. Home-built multiphoton microscopes are easy to build, highly customizable, and cost effective. For many imaging applications a 3-axis motorized stage is critical, but commercially available motorization hardware (motorized translators, controller boxes, etc) are often very expensive. Furthermore, the firmware on commercial motor controllers cannot easily be altered and is not usually designed with a microscope stage in mind. Here we describe an open-source motorization solution that is simple to construct, yet far cheaper and more customizable than commercial offerings. The cost of the controller and motorization hardware are under $1000. Hardware costs are kept low by replacing linear actuators with high quality stepper motors. Electronics are assembled from commonly available hobby components, which are easy to work with. Here we describe assembly of the system and quantify the positioning accuracy of all three axes. We obtain positioning repeatability of the order of 1 μm in X/Y and 0.1 μm in Z. A hand-held control-pad allows the user to direct stage motion precisely over a wide range of speeds (10(-1) to 10(2) μm·s(-1)), rapidly store and return to different locations, and execute "jumps" of a fixed size. In addition, the system can be controlled from a PC serial port. Our "OpenStage" controller is sufficiently flexible that it could be used to drive other devices, such as micro-manipulators, with minimal modifications.

  18. Bragg diffraction from sub-micron particles isolated by optical tweezers

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Yuan, E-mail: ygao0709@anl.gov; Harder, Ross; Southworth, Stephen; Guest, Jeffrey; Ocola, Leonidas; Young, Linda [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Scherer, Norbert; Yan, Zijie [Department of Chemistry, University of Chicago, Chicago, IL 60637 (United States); Pelton, Matthew [Department of Physics, University of Maryland, Baltimore County, MD 21250 (United States)

    2016-07-27

    We describe an apparatus using dynamic holographic optical tweezers which is capable of trapping and aligning a single micron scale anisotropic ZnO particle for x-ray Bragg diffraction experiments. The optical tweezers demonstrate enough stability to perform coherent x-ray diffraction imaging.

  19. Dynamics of Dissolved Organic Matter and Microbes in Seawater through Sub-Micron Particle Size Analyses

    Digital Repository Service at National Institute of Oceanography (India)

    Goes, J.I.; Balch, W.M.; Vaughn, J.M.; Gomes, H.R.

    processes responsible for the dynamics of DOM rely on monitoring the consumption and breakdown of specific compounds of phytoplankton origin, generally, through the use of labeled precursors and substrates (Kirchman et al., 1991; Fry et al., 1996; Rich et al... attempts to determine the molecular weight or size spectrum of DOM using size exclusion chromatography, but these have generally proven unsatisfactory (Beckett et al., 1987). One reason is that DOM is exposed to high shear stresses during separation...

  20. Analysis and Test Development for Parasitic Fails in Deep Sub-Micron Memory Devices

    NARCIS (Netherlands)

    Irobi, I.S.

    2011-01-01

    Emerging technology trends are gravitating towards extremely high levels of integration at the package and chip levels, and use of deeply scaled technology in nanometer, approaching 10nm CMOS. Challenges will arise due to the ability to design complex systems such as robots that encompass sensors,

  1. Enhanced strength and temperature dependence of mechanical properties of Li at small length scales and its implications for Li metal anodes

    CERN Document Server

    and, Chen Xu; Aryanfar, Asghar; Viswanathan, Venkatasubramanian; Greer, Julia R

    2016-01-01

    Most next-generation Li-ion battery chemistries require a functioning lithium metal (Li) anode. However, its application in secondary batteries has been inhibited because of uncontrollable dendrite growth during cycling. Mechanical suppression of dendrite growth through solid polymer electrolytes (SPE) or through robust separators has shown the most potential for alleviating this problem. Studies of the mechanical behavior of Li at any length scale and temperature are virtually non-existent because of its extreme reactivity, which renders sample preparation, transfer, microstructure characterization and mechanical testing prohibitively challenging. We conduct nano-mechanical experiments in an in-situ Scanning Electron Microscope and show that micron-sized Li attains extremely high strengths of 105 MPa at room temperature and of 35MPa at 90$^\\circ$C. We demonstrate that single crystalline Li exhibits a power-law size-effect at the micron- and sub-micron length scales, with the strengthening exponent of -0.68 a...

  2. Corrosão de refratários utilizados na siderurgia. Parte III: caracterização de refratários comerciais Corrosion of refractories used in steel metallurgy. Part III: characterization of commercial refractories

    Directory of Open Access Journals (Sweden)

    S. R. Bragança

    2013-03-01

    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-se com resultados experimentais. As propriedades físicas e microestruturais de refratários comerciais foram estudadas, considerando-se as diferenças entre elas e implicações com a qualidade e provável vida útil do refratário. Assim, investigou-se os diversos tipos de refratários utilizados como revestimento em uma panela de aço, como de sobre-linha (freeboard, linha de escória e linha de metal. Os refratários magnésia-carbono e doloma-carbono foram avaliados, destacando-se também as diferenças entre eles. Os materiais analisados mostraram características favoráveis a uma elevada resistência ao processo de corrosão, apresentando uma série de propriedades a serem escolhidas de acordo com a prática industrial.The main aspects found in the literature about refractories corrosion were reviewed, 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, this study comprised various types of refractories used as lining on steel ladle, as on freeboard, slag line and metal line. Magnesia-carbon and doloma-carbon refractories were analyzed, highlighting the differences between them. The examined materials showed characteristics favoring high resistance to corrosion process, presenting a series of properties to be selected in accordance with industry practice.

  3. Broadband absorption enhancement in organic solar cells using refractory plasmonic ceramics

    Science.gov (United States)

    Magdi, Sara; Ji, Dengxin; Gan, Qiaoqiang; Swillam, Mohamed A.

    2017-01-01

    We theoretically demonstrate absorption enhancement in organic solar cells (OSC) due to the incorporation of titanium nitride and zirconium nitride plasmonic nanostructures. Localizing light using plasmonic nanostructures has the potential to overcome the absorption limitations of OSC and improve their power conversion efficiency. Thus, using C-MOS compatible, cheap, and abundant materials, such as refractory plasmonics, for light trapping could facilitate their commercialization. This work shows that transition metal nitrides have comparable performance to Ag when placed as the nanopatterned back electrode. In addition, the effect of adding TiN nanoparticles and nanowires inside the active layer has been analyzed.

  4. Refractory Materials for Flame Deflector Protection

    Science.gov (United States)

    Calle, Luz M.; Hintze, Paul E.; Parlier, Christopher R.; Sampson, Jeffrey W.; Curran, Jerome P.; Kolody, Mark R.; Peruisich, Stephen A.

    2010-01-01

    Fondu Fyre (FF) is currently the only refractory material qualified for use in the flame trench at KSC's Shuttle Launch Pads 39A and 3913. However, the material is not used as it was qualified and has undergone increasingly frequent and severe degradation due to the launch blasts. This degradation is costly as well as dangerous for launch infrastructure, crew and vehicle. The launch environment at KSC is unique. The refractory material is subject to the normal seacoast environment, is completely saturated with water before launch, and is subjected to vibrations and aggressive heat/blast conditions during launch. This report presents results comparing two alternate materials, Ultra-Tek FS gun mix and Kruzite GR Plus, with Fondu Fyre. The materials were subjected to bulk density, porosity, compression strength, modulus of rupture and thermal shock tests. In addition, test specimens were exposed to conditions meant to simulate the launch environment at KSC to help better understand how the materials will perform once installed.

  5. Ziconotide: a new option for refractory pain.

    Science.gov (United States)

    Prommer, Eric

    2006-06-01

    Ziconotide has been introduced as a new nonopioid treatment for chronic pain. Structurally, it is a peptide, the synthetic analog of the omega-conotoxin, derived from the marine snail, Conus magus. N-type voltage-sensitive calcium channels play a role in the transmission of nociceptive stimuli and also are involved in the release of neurotransmitters important in pain transmission. Ziconotide's therapeutic benefit derives from its potent and selective blockade of neuronal-type voltage-sensitive calcium channels. Blockade of the channels results in suppression of abnormal ectopic discharges from the injury site or the dorsal root ganglia, possibly resulting in decreased neuroplasticity, and decreased synaptic transmission that leads to the generation of chronic pain syndromes. The advantage of ziconotide is that tolerance does not occur, while disadvantages associated with ziconotide are the need for intrathecal administration and significant neurotoxicites associated with its use. When tested in clinical trials, ziconotide has been shown to have synergistic or additive value to the effect of morphine. Ziconotide, formerly known also as SNX- 111, represents a new class of agents, the N-type calcium channel blockers. These may represent another option for patients with refractory pain and refractory pain syndromes.

  6. Intravesical silver nitrate for refractory hemorrhagic cystitis.

    Science.gov (United States)

    Montgomery, Brian D; Boorjian, Stephen A; Ziegelmann, Matthew J; Joyce, Daniel D; Linder, Brian J

    2016-09-01

    Hemorrhagic cystitis is a challenging clinical entity with limited evidence available to guide treatment. The use of intravesical silver nitrate has been reported, though supporting literature is sparse. Here, we sought to assess outcomes of patients treated with intravesical silver nitrate for refractory hemorrhagic cystitis. We identified nine patients with refractory hemorrhagic cystitis treated at our institution with intravesical silver nitrate between 2000-2015. All patients had failed previous continuous bladder irrigation with normal saline and clot evacuation. Treatment success was defined as requiring no additional therapy beyond normal saline irrigation after silver nitrate instillation prior to hospital discharge. Median patient age was 80 years (IQR 73, 82). Radiation was the most common etiology for hemorrhagic cystitis 89% (8/9). Two patients underwent high dose (0.1%-0.4%) silver nitrate under anesthesia, while the remaining seven were treated with doses from 0.01% to 0.1% via continuous bladder irrigation for a median of 3 days (range 2-4). All nine patients (100%) had persistent hematuria despite intravesical silver nitrate therapy, requiring additional interventions and red blood cell transfusion during the hospitalization. There were no identified complications related to intravesical silver nitrate instillation. Although well tolerated, we found that intravesical silver nitrate was ineffective for bleeding control, suggesting a limited role for this agent in the management of patients with hemorrhagic cystitis.

  7. Extracorporeal membrane oxygenation for refractory cardiac arrest

    Directory of Open Access Journals (Sweden)

    Steven A Conrad

    2017-01-01

    Full Text Available Extracorporeal cardiopulmonary resuscitation (ECPR is the use of rapid deployment venoarterial (VA extracorporeal membrane oxygenation to support systemic circulation and vital organ perfusion in patients in refractory cardiac arrest not responding to conventional cardiopulmonary resuscitation (CPR. Although prospective controlled studies are lacking, observational studies suggest improved outcomes compared with conventional CPR when ECPR is instituted within 30-60 min following cardiac arrest. Adult and pediatric patients with witnessed in-hospital and out-of-hospital cardiac arrest and good quality CPR, failure of at least 15 min of conventional resuscitation, and a potentially reversible cause for arrest are candidates. Percutaneous cannulation where feasible is rapid and can be performed by nonsurgeons (emergency physicians, intensivists, cardiologists, and interventional radiologists. Modern extracorporeal systems are easy to prime and manage and are technically easy to manage with proper training and experience. ECPR can be deployed in the emergency department for out-of-hospital arrest or in various inpatient units for in-hospital arrest. ECPR should be considered for patients with refractory cardiac arrest in hospitals with an existing extracorporeal life support program, able to provide rapid deployment of support, and with resources to provide postresuscitation evaluation and management.

  8. Treatment of relapsed and refractory Hodgkin Lymphoma

    Science.gov (United States)

    von Tresckow, Bastian

    2017-01-01

    Despite the high first line cure rates in patients with Hodgkin Lymphoma (HL) still 10–20% of patients suffer from relapsed or refractory disease. High dose chemotherapy (HDCT) followed by autologous stem cell transplant (ASCT) is standard of care for suitable patients with relapsed or refractory HL and allows for cure in approximately 50%. Due to the poor prognosis of high risk patients even with HDCT and ASCT, consolidation strategies have been evaluated to improve the cure rates. For patients with recurrence after HDCT and ASCT, treatment is palliative in most cases. The anti CD30 antibody-drug conjugate brentuximab vedotin (BV) has been shown to induce high response rates in these patients; however, durable responses were reported in a small percentage of patients only. For carefully selected patients with multiple relapses, dose-reduced allogeneic transplant (RICallo) is a potentially curative option. The role of RICallo will have to be reevaluated in the era of anti-programmed death-1 (PD1) antibodies. PMID:27496309

  9. INFLIXIMAB IN TREATMENT OF REFRACTORY JUVENILE ARTHRITIS

    Directory of Open Access Journals (Sweden)

    I.P. Nikishina

    2010-01-01

    Full Text Available Inclusion to the clinical practice of genetically engineered biological medications opens new opportunities in treatment of juvenile arthritis. The article summarizes an experience of treatment of juvenile arthritis with infliximab in children’s department of Scientific Center of Rheumatology, Russian Academy of Medical Sciences. The analysis included 55 patients (16 children had systemic type, 23 — polyarticular type of juvenile arthritis, and 16 patients had juvenile spondylarthritis, treated with infliximab in 2002–2009 years. Infliximab was administrated in patients with high activity of the disease refractory to the modern basic therapy. Patients received intravenous infliximab 3–5 mg/kg daily according to the standard scheme (on 0, 2, 6 weeks and further every 8 weeks. Therapy with this drug was estimated as effective (improvement on 30% and more according ACRpedi in 80% of patients: 16% achieved ACR30, 29% — ACR50, 26% — ACR70, and 9% — ACR90. Unfavorable effects (infusion reactions were detected in 16% of cases. Infections, including one case of disseminated tuberculosis, developed in 20% of patients. Thus, treatment with infliximab is effective and has good «risk–benefit» ratio in treatment of patients with refractory juvenile arthritis. Key words: children, juvenile arthritis, infliximab, treatment.(Voprosy sovremennoi pediatrii — Current Pediatrics. 2010;9(1:142-149

  10. Vigabatrin and lamotrigine in refractory epilepsy.

    Science.gov (United States)

    Stolarek, I; Blacklaw, J; Forrest, G; Brodie, M J

    1994-08-01

    Epilepsy arises from an imbalance of inhibitory and excitatory influences in the brain. Vigabatrin (VIG) decreases the breakdown of the inhibitory neurotransmitter gamma-aminobutyric acid, whereas lamotrigine (LTG) reduces presynaptic excitatory amino acid release. 22 patients with refractory epilepsy, treated with an anticonvulsant regimen containing VIG, entered a balanced, double blind, placebo controlled, crossover trial of additional LTG. Treatment periods of 12 weeks (25 mg, 50 mg, 100 mg LTG twice daily for four weeks at each dose, and matched placebo) were followed by wash out intervals of four weeks. 14 of the 20 patients completing the study improved, resulting in a significant fall in seizure days and numbers. Analysis of seizure type confirmed a beneficial effect on partial and secondary generalised tonic-clonic seizures. At the highest LTG dose (200 mg daily) there was a median fall of 37% in seizure count with nine (45%) patients reporting > 50% reduction. Three of these patients were seizure free during this month of treatment. Side effects were minimal throughout the study. Concentrations of other antiepileptic drugs, including those of carbamazepine 10,11-epoxide, were not modified by LTG. This study suggests a substantial efficacy for a regimen containing VIG and LTG. Combinations of drugs with complementary modes of action may provide a rational pharmacological approach to the management of refractory epilepsy.

  11. [Lenvatinib in radioiodine refractory thyroid carcinomas].

    Science.gov (United States)

    de la Fouchardiere, Christelle

    2016-11-01

    Differentiated thyroid cancers are usually cured by an appropriate surgery and a radioiodine remnant ablation. If metastases occur, successive radioiodine administrations and/or local treatments can be provided. Nevertheless, some patients will be, or become refractory to radioiodine. In case of significant and rapid progression of metastatic lesions, they will be candidate to kinase inhibitor treatments. Two agents are now approved in this situation: sorafenib and lenvatinib. Lenvatinib (Lenvima®) is a tyrosine kinase inhibitor (TKI) targeting the VEGFR1-3, FGFR 1-4, PDGFR-α, RET and c-kit. It received an FDA and EMA approval in February and March 2015 for the treatment of radioiodine refractory thyroid cancers following the SELECT study's results. In this study, patients treated with lenvatinib had a significant increase in progression-free survival (18.3 months vs. 3.6 months; HR=0.21; CI=0.14-0.31, P Cancer. Published by Elsevier Masson SAS. All rights reserved.

  12. 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.

  13. The Ahmed Glaucoma Valve in Refractory Glaucoma: Experiences ...

    African Journals Online (AJOL)

    BACKGROUND: The management of refractory glaucoma is a challenging task for any glaucoma surgeon. This study is aimed to evaluate the efficacy of Ahmed Glaucoma Valve implantation in refractory glaucomas in South-West Ethiopia. METHODS: A retrospective review was conducted on the charts of consecutive ...

  14. Refractory gastro-oesophageal reflux disease: a major management ...

    African Journals Online (AJOL)

    2009-05-12

    May 12, 2009 ... Refractory oesophagitis (non-healing of erosions) is rare since the advent of potent gastric acid inhibition with proton pump inhibitors (PPIs). However, refractory gastro-oesophageal reflux disease (GORD) symptoms, both typical and atypical (cough, chronic hoarseness, asthma and atypical chest pain), ...

  15. Quasi-coherent thermal emitter based on refractory plasmonic materials

    DEFF Research Database (Denmark)

    Liu, Jingjing; Guler, Urcan; Lagutchev, Alexei

    2015-01-01

    The thermal emission of refractory plasmonic metamaterial - a titanium nitride 1D grating - is studied at high operating temperature (540 degrees C). By choosing a refractory material, we fabricate thermal gratings with high brightness that are emitting mid-infrared radiation centered around 3 mu m...

  16. Dermatitis Herpetiformis Refractory to Gluten-free Dietary Treatment.

    Science.gov (United States)

    Hervonen, Kaisa; Salmi, Teea T; Ilus, Tuire; Paasikivi, Kaija; Vornanen, Martine; Laurila, Kaija; Lindfors, Katri; Viiri, Keijo; Saavalainen, Päivi; Collin, Pekka; Kaukinen, Katri; Reunala, Timo

    2016-01-01

    Dermatitis herpetiformis (DH) is a blistering skin disease, which is regarded as an extra-intestinal manifestation of coeliac disease. Refractory cases of coeliac disease, that do not respond to a gluten-free diet and which carry an increased risk of lymphoma, are well-known in coeliac disease. To determine whether refractory cases of DH with active rash and persistent small bowel atrophy occur we analysed our series of 403 patients with DH. Seven (1.7%) patients, who had been on a gluten-free diet for a mean of 16 years, but who still required dapsone to treat the symptoms of DH, were identified. Of these, one patient died from mucinous adenocarcinoma before re-examination. At re-examination skin immunoglobulin A (IgA) deposits were found in 5/6 refractory and 3/16 control DH patients with good dietary response. Small bowel mucosa was studied at re-examination from 5 refractory and 8 control DH patients and was normal in all 5 refractory and 7/8 control DH patients. One refractory DH patient died from adenocarcinoma, but no lymphoma developed in any of the patients. This study documents for the first time refractory DH, in which the rash is non-responsive to a gluten-free diet, but the small bowel mucosa heals. This differs from refractory coeliac disease, in which the small bowel mucosa does not heal on a gluten-free diet.

  17. 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,

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

    Indian Academy of Sciences (India)

    Lightweight cordierite–mullite refractories with low coefficients of thermal conductivity (CTCs), high strengths and high thermal-shock resistances were prepared using porous cordierite ceramics as aggregates. Phase compositions and microstructures of lightweight refractories were measured by X-ray diffraction (XRD), ...

  19. 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...

  20. Development of alumino-silicate refractories in Ghana | Kisiedu ...

    African Journals Online (AJOL)

    The clay and kaolin minerals could be used to produce fireclay refractories for construction of incinerators operating at maxi-mum temperatures of about 1000 oC. The performance of the refractories was demonstrated by producing bric-ks to construct kilns and incinerators for the ceramic industries and hospitals. Journal of ...

  1. Diagnosis and Treatment of Refractory Gastroesophageal Reflux Disease (GERD

    Directory of Open Access Journals (Sweden)

    Selfie

    2015-12-01

    Full Text Available Gastroesophageal reflux disease (GERD was a damage in mucosal layer caused by gastric acid reflux. GERD was found about 10-20% in Western Countries and less in Asia, about 2,6-6,7%. Among different type of GERD, refractory GERD was a problem found in daily clinical practice. This terminology was used in patients with regurgitation and heartburn symptoms which is not responsive to 8 weeks proton pump inhibitor (PPI therapy. There were several mechanisms underlying the etiology and pathophysiology of refractory GERD. In general, refractory GERD diagnosis was based on clinical findings, objective endoscopic examination, ambulatory reflux monitoring, and response to antiacid-secretion therapy. Reevaluation of patients compliance should be the first step in refractory GERD management. A further treatment strategies could be started, consist of medical and surgical therapies. A basic clinical knowledge of refractory GERD would help clinician in deciding the best approach for diagnosis and therapy.

  2. 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)

  3. 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.

  4. Improved Sand-Compaction Method for Lost-Foam Metal Casting

    Science.gov (United States)

    Bakhtiyarov, Sayavur I.; Overfelt, Ruel A.

    2008-01-01

    An improved method of filling a molding flask with sand and compacting the sand around a refractory-coated foam mold pattern has been developed for incorporation into the lost-foam metal-casting process. In comparison with the conventional method of sand filling and compaction, this method affords more nearly complete filling of the space around the refractory-coated foam mold pattern and more thorough compaction of the sand. In so doing, this method enables the sand to better support the refractory coat under metallostatic pressure during filling of the mold with molten metal.

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

    Science.gov (United States)

    2017-10-09

    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

  6. Ancient asteroids enriched in refractory inclusions.

    Science.gov (United States)

    Sunshine, J M; Connolly, H C; McCoy, T J; Bus, S J; La Croix, L M

    2008-04-25

    Calcium- and aluminum-rich inclusions (CAIs) occur in all classes of chondritic meteorites and contain refractory minerals predicted to be the first condensates from the solar nebula. Near-infrared spectra of CAIs have strong 2-micrometer absorptions, attributed to iron oxide-bearing aluminous spinel. Similar absorptions are present in the telescopic spectra of several asteroids; modeling indicates that these contain approximately 30 +/- 10% CAIs (two to three times that of any meteorite). Survival of these undifferentiated, large (50- to 100-kilometer diameter) CAI-rich bodies suggests that they may have formed before the injection of radiogenic 26Al into the solar system. They have also experienced only modest post-accretionary alteration. Thus, these asteroids have higher concentrations of CAI material, appear less altered, and are more ancient than any known sample in our meteorite collection, making them prime candidates for sample return.

  7. Multimodal intrathecal analgesia in refractory cancer pain.

    Science.gov (United States)

    Mastenbroek, Thierry C; Kramp-Hendriks, Bianca J; Kallewaard, Jan Willem; Vonk, Johanna M

    2017-01-01

    Cancer pain treatment has improved over the last decades. The majority of this population can be treated effectively with analgesics following the Guidelines of the original World Health Organisation (WHO). Unfortunately 10-15% of these patients still suffer from severe and refractory cancer pain, especially in the terminal phases of disease and require additional pain management modalities. Therefore, end-stage clinical interventions are particularly needed to minimize the perception of pain. With intrathecal therapy (ITT), drugs are delivered close to their site of action in the central nervous system avoiding first-pass metabolism and blood-brain barrier. It may improve analgesia with a smaller dose and possibly achieve a reduction in systemic or cerebral side effects compared to oral supplied medication alone. Multimodal analgesia enables further dose reduction with improved analgesia and fewer side effects. In this retrospective research we investigated the effectiveness and side-effect profile of intrathecal morphine, bupivacaine and clonidine. Patients were followed until death occurred. Pain scores and side effects were recorded before initiating ITT (T0), just after initiating ITT (T1), at hospital discharge (T2), in the ambulant setting (T3) and the last obtained scores before death occurred (T4). Nine patients were included who suffered from severe and refractory cancer pain, not reacting to conventional pain management or had intolerable side effects. Primary tumour location was pancreatic (4), urothelial (3) and prostate (2). Primary pain was considered neuropathic or mixed neuropathic-nociceptive. The treatment team consisted of an anaesthetist, specialized nurse in coordination with primary physician, treating oncologist and specialized home care. All patients were free of pain after initiation of the intrathecal therapy. The average follow-up period was 11 weeks in which there was a slight increase in NRS-score. In the last days before death

  8. Refractory pruritus in primary biliary cirrhosis

    Science.gov (United States)

    Pinheiro, Nuno Cercas; Marinho, Rui Tato; Ramalho, Fernando; Velosa, José

    2013-01-01

    Pruritus is a major symptom of primary biliary cirrhosis, cholestatic autoimmune disease which affects mostly middle-age women. Often, it can be severe and refractory to multiple treatments, and mostly affecting the patient’s health-related quality of life. Intense pruritus can be itself an indication to liver transplantation, in extreme cases leading to suicide. Its physiopathology has not yet been fully elucidated, but recent studies added the elevation of autotaxin and lysophosphatidic acid to the group of classic mechanisms already linked to cholestatic pruritus. In this case report we illustrate how ultraviolet B phototherapy appears to successfully control severe pruritus and contribute to the healing of pruritic skin lesions caused by intense scratching. There is limited medical literature concerning this therapeutic approach on cholestatic pruritus, but we hope that further randomised controlled trials will successfully establish it as an effective treatment in the near future. PMID:24234429

  9. Esquizofrenia refratária Refractory schizophrenia

    Directory of Open Access Journals (Sweden)

    Helio Elkis

    2007-10-01

    Full Text Available OBJETIVO: O propósito deste artigo é o de revisar vários aspectos da esquizofrenia refratária levando em conta questões relacionadas à definição, aspectos clínicos, correlatos psicobiológicos, tratamentos farmacológicos e não farmacológicos, assim como preditores de resposta terapêutica. MÉTODO: Pesquisa no Medline, assim como artigos dos autores. RESULTADOS E CONCLUSÕES: Pelo menos um terço dos pacientes com esquizofrenia são refratários a tratamento com antipsicóticos e as evidências apontam a clozapina em monoterapia como a principal opção nesses casos. A politerapia com antipsicóticos não tem apoio em evidências. Ensaios clínicos recentes mostraram que a potencialização da clozapina com outros antipsicóticos não é superior ao placebo.OBJECTIVE: The aim of the present paper is to review the various aspects of refractory schizophrenia regarding issues such as definitions, clinical aspects, psychobiological correlates, pharmacological and non-pharmacological treatment options and predictors of treatment response. METHOD: Medline search as well as articles of the authors. RESULTS AND CONCLUSIONS: Refractory schizophrenia affects at least one third of patients with schizophrenia and the best evidence shows that is monotherapy with clozapine remains the mainstay for the treatment of such condition. Antipsychotic polipharmacy is not supported by current evidence and recent clinical trials have shown that clozapine augmentation with antipsychotics has no benefit over placebo.

  10. Pegloticase: in treatment-refractory chronic gout.

    Science.gov (United States)

    Lyseng-Williamson, Katherine A

    2011-11-12

    Intravenous pegloticase offers a novel approach to treating chronic gout refractory to conventional therapy. Pegloticase is a recombinant polyethylene glycol-conjugated form of uricase (a uric acid-specific enzyme lacking in humans) that catalyses the oxidation of uric acid to allantoin. In randomized, placebo-controlled, double-blind, 6-month, phase III trials, intravenous pegloticase 8 mg every 2 or 4 weeks provided sustained reductions in plasma uric acid levels to less than the therapeutic target of 6 mg/dL in a substantial proportion of patients with chronic gout who were refractory to, or intolerant of, conventional urate-lowering therapy. Pegloticase 8 mg every 2 weeks was associated with disease-modifying benefits relative to placebo, as shown by significant improvements from baseline in tophi resolution, frequency of gout flares and tender joint count, and clinically relevant and statistically significant improvements from baseline in health-related quality-of-life parameters related to disability, pain and physical function. Pegloticase 8 mg every 4 weeks was also significantly more effective than placebo with regard to most, but not all, of these endpoints. Preliminary data from an open-label extension of the phase III trials indicate that long-term treatment with pegloticase 8 mg every 2 or 4 weeks may maintain plasma uric acid normalization in patients who experienced a sustained uric acid response during the phase III trials. The most common serious adverse events associated with pegloticase are gout flares, infusion reactions and anaphylaxis. In addition, exacerbation of pre-existing congestive heart failure was reported in 2% of patients receiving pegloticase 8 mg every 2 weeks in the phase III trials.

  11. Tacrolimus in Corticosteroid-Refractory Vernal Keratoconjunctivitis.

    Science.gov (United States)

    Chatterjee, Samrat; Agrawal, Deepshikha

    2016-11-01

    To evaluate the efficacy of 0.03% tacrolimus in the treatment of corticosteroid-refractory vernal keratoconjunctivitis (VKC). This open-label study enrolled 30 patients with VKC who were not responding to topical corticosteroid treatment for at least 4 weeks. All patients were treated with 0.03% tacrolimus eye ointment 3 times daily, 0.05% ketotifen eye drops twice daily, and preservative-free artificial tears. Symptoms (itching, redness, watering, discharge, burning, and photophobia) and signs (conjunctival injection, papillae, cobblestone papillae, limbal inflammation, or hypertrophy and corneal epithelial staining) were graded on a 4-point scale at enrolment, after 4 weeks, and at the end of treatment period, which was at 12 weeks. Composite scores for symptoms and signs were computed by summing individual scores. Treatment failure was denoted if additional treatment with corticosteroids were required. The composite scores for symptoms (10.8, 3.8, 3.4) and signs (8.7, 4.7, 4.0) in 23 patients showed a statistically significant (P < 0.05) improvement from baseline to the 4- and 12-week visits. Among the signs, upper tarsal papilla showed improvement only at 12 weeks, but the scores for giant cobblestone papillae did not reach statistically significant reduction even at 12 weeks. There was improvement in visual acuity at 12 weeks, although it was not statistically significant (P = 0.05). Treatment failure was recorded in 17% patients. The only adverse effect reported was transient stinging sensation lasting for a few days. Tacrolimus 0.03% was apparently safe and effective in treating patients with steroid-refractory VKC. A small subset of patients may still require supplemental topical corticosteroids for resolution of their symptoms.

  12. Nitroimidazole-refractory giardiasis: a growing problem requiring rational solutions.

    Science.gov (United States)

    Carter, E R; Nabarro, L E; Hedley, L; Chiodini, P L

    2018-01-01

    Giardia intestinalis is microaerophilic diarrhoea-causing protozoan common in countries with suboptimal sanitation. Standard treatment is with nitroimidazoles, but a growing number of refractory cases is being reported. Treatment failure has become increasingly prevalent in travellers who contract giardiasis in Asia. Clinicians are increasingly falling back on second-line and less well-known drugs to treat giardiasis. To review nitroimidazole-refractory G. intestinalis infection, examine the current efficacy of standard therapeutic agents, consider potential resistance mechanisms which could cause treatment failure and describe the practical aspects of managing this emerging clinical problem. A PubMed search was conducted using combinations of the following terms: refractory, Giardia, giardiasis, resistance and treatment. Articles on the pharmacotherapy, drug resistance mechanisms and use of alternative agents in nitroimidazole-refractory giardiasis were reviewed. We review the standard drugs for giardiasis, including their efficacy in initial treatment, mode of action and documented in vitro and in vivo drug resistance. We assess the efficacy of alternative drugs in nitroimidazole-refractory disease. Existing data suggest a potential advantage of combination treatment. An optimal treatment strategy for refractory giardiasis has still to be determined, so there is no standard treatment regimen for nitroimidazole-refractory giardiasis. Further work on drug resistance mechanisms and the use of drug combinations in this condition is a priority. Copyright © 2017. Published by Elsevier Ltd.

  13. Pack cementation diffusion coatings for Fe-base and refractory alloys. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, R.A. [Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering

    1998-03-10

    With the aid of computer-assisted calculations of the equilibrium vapor pressures in halide-activated cementation packs, processing conditions have been identified and experimentally verified for the codeposition of two or more alloying elements in a diffusion coating on a variety of steels and refractory metal alloys. A new comprehensive theory to treat the multi-component thermodynamic equilibria in the gas phase for several coexisting solid phases was developed and used. Many different processes to deposit various types of coatings on several types of steels were developed: Cr-Si codeposition for low- or medium-carbon steels, Cr-Al codeposition on low-carbon steels to yield either a Kanthal-type composition (Fe-25Cr-4Al in wt.%) or else a (Fe, Cr){sub 3}Al surface composition. An Fe{sub 3}Al substrate was aluminized to achieve an FeAl surface composition, and boron was also added to ductilize the coating. The developmental Cr-lean ORNL alloys with exceptional creep resistance were Cr-Al coated to achieve excellent oxidation resistance. Alloy wires of Ni-base were aluminized to provide an average composition of Ni{sub 3}Al for use as welding rods. Several different refractory metal alloys based on Cr-Cr{sub 2}Nb have been silicided, also with germanium additions, to provide excellent oxidation resistance. A couple of developmental Cr-Zr alloys were similarly coated and tested.

  14. 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.

  15. Composition and process for making an insulating refractory material

    Science.gov (United States)

    Pearson, A.; Swansiger, T.G.

    1998-04-28

    A composition and process are disclosed for making an insulating refractory material. The composition includes calcined alumina powder, flash activated alumina powder, an organic polymeric binder and a liquid vehicle which is preferably water. Starch or modified starch may also be added. A preferred insulating refractory material made with the composition has a density of about 2.4--2.6 g/cm{sup 3} with reduced thermal conductivity, compared with tabular alumina. Of importance, the formulation has good abrasion resistance and crush strength during intermediate processing (commercial sintering) to attain full strength and refractoriness.

  16. Functional characterisation of metal(loid) processes in planta through the integration of synchrotron techniques and plant molecular biology

    Science.gov (United States)

    Donner, Erica; Punshon, Tracy; Guerinot, Mary Lou; Lombi, Enzo

    2013-01-01

    Functional characterisation of the genes regulating metal(loid) homeostasis in plants is a major focus of crop biofortification, phytoremediation, and food security research. This paper focuses on the potential for advancing plant metal(loid) research by combining molecular biology and synchrotron-based techniques. Recent advances in x-ray focussing optics and fluorescence detection have greatly improved the potential of synchrotron techniques for plant science research, allowing metal(loids) to be imaged in vivo in hydrated plant tissues at sub-micron resolution. Laterally resolved metal(loid) speciation can also be determined. By using molecular techniques to probe the location of gene expression and protein localisation and combining it with this synchrotron-derived data, functional information can be effectively and efficiently assigned to specific genes. This paper provides a review of the state of the art in this field, and provides examples as to how synchrotron-based methods can be combined with molecular techniques to facilitate functional characterisation of genes in planta. PMID:22200921

  17. Refractory primary immune thrombocytopenia with subsequent del(5q) MDS

    DEFF Research Database (Denmark)

    Bech Mortensen, Thomas; Frederiksen, Henrik; Marcher, Claus Werenberg

    2017-01-01

    A patient with refractory primary immune thrombocytopenia (ITP) characterised by severe skin and mucosal bleedings was treated with several ITP-directed therapies including cyclophosphamide. He later developed therapy-related del(5q) myelodysplastic syndrome with no dysplastic morphological...

  18. 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...... with cirrhosis and refractory ascites in a tertiary unit. MATERIAL AND METHODS: We performed a systematic search of literature in May 2014. In addition, 61 patients with cirrhosis and ascites were identified and followed from development of refractory ascites until death or end of follow-up. RESULTS: Fourteen...... 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...

  19. Refractory Coated/Lined Low Density Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation in this proposed effort is the development of refractory coated or lined low density structures. Lightweight structures are desirable for space...

  20. Recycling MgO-C refractory in electric arc furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Conejo, A.N. [Metallurgy Department, Morelia Technological Institute, Morelia (Mexico); Lule, R.G.; Lopez, F. [Process Engineering Department-Steelmaking Shop, Lazaro Cardenas City (Mexico); Rodriguez, R. [Refractories Department, Lazaro Cardenas City (Mexico)

    2006-11-15

    MgO-C refractory recycling from electric arc furnaces and ladle furnaces has been carried out during the melting of direct reduced iron (DRI). Metallurgical trials to define the effects of refractory recycling on energy consumption, melting time, flux consumption and refractory consumption are reported in this work. The method of preparation as well as the method of injection is also included in this study. Based on current results, the practice of recycling spent refractory is highly recommended. Visual inspection indicates the potential benefits in slag foaming which starts to form at the beginning of the heat thus allowing the use of full power transformer and in turn results in faster melting rates. (author)

  1. 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).

  2. Silica crown refractory corrosion in glass melting furnaces

    National Research Council Canada - National Science Library

    Balandis A; Nizeviciene D

    2011-01-01

    ... of glass furnaces, when the rate of corrosion of crowns were about 2 times greater. The change of these parameters, the chemical composition and formation of the microcracks in the used silica refractories material were studied...

  3. Refractory, Abrasive, and Other Industrial Minerals Operations - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer includes refractory, abrasive, and other industrial minerals operations in the United States. The data represent commodities covered by the Minerals...

  4. Compressive Creep and Thermophysical Performance of Mullite Refractories

    Energy Technology Data Exchange (ETDEWEB)

    Hemrick, JG

    2002-04-01

    Compressive creep testing of ten commercially available mullite refractories was performed at 1300-1450 C and at static stresses between 0.2-0.6 MPa. These refractories were examined because they are used in borosilicate glass furnace crowns and superstructures along with in sidewall applications. Additionally, despite their high cost ({approx}$500/ft{sup 3}) they are cheaper than other refractories such as chrome alumina ({approx}$3000/ft{sup 3}) or fusion-cast alumina ({approx}900/ft{sup 3}) which are used as replacements for traditional silica refractories in harsh oxy-fuel environments. The corrosion resistances of these ten materials were also evaluated. In addition, measurements were made that tracked their dimensional stability, phase content, microstructure, and composition as a function of temperature and time. The techniques used for these characterizations and their respective analyses are described. An intent of this study was to provide objective and factual results whose interpretations were left to the reader.

  5. Deformation Behavior of Nanoporous Metals

    Energy Technology Data Exchange (ETDEWEB)

    Biener, J; Hodge, A M; Hamza, A V

    2007-11-28

    of free surfaces can no longer be neglected. As the material becomes more and more constraint by the presence of free surfaces, length scale effects on plasticity become more and more important and bulk properties can no longer be used to describe the material properties. Even the elastic properties may be affected as the reduced coordination of surface atoms and the concomitant redistribution of electrons may soften or stiffen the material. If, and to what extend, such length scale effects control the mechanical behavior of nanoporous materials depends strongly on the material and the characteristic length scale associated with its plastic deformation. For example, ductile materials such as metals which deform via dislocation-mediated processes can be expected to exhibit pronounced length scale effects in the sub-micron regime where free surfaces start to constrain efficient dislocation multiplication. In this chapter we will limit our discussion to our own area of expertise which is the mechanical behavior of nanoporous open-cell gold foams as a typical example of nanoporous metal foams. Throughout this chapter we will review our current understanding of the mechanical properties of nanoporous open-cell foams including both experimental and theoretical studies.

  6. A mechanical refractory period of chondrocytes after dynamic hydrostatic pressure.

    Science.gov (United States)

    Cao, Xu; Xia, Hansong; Li, Na; Xiong, Kun; Wang, Zili; Wu, Song

    2015-06-01

    Mechanical stimulation, a crucial factor for maintaining the cartilaginous phenotype and promoting the chondrogenesis, has been widely used in autologous chondrocyte transplantation. This study was designed to investigate a novel concept of mechanical refractory period of chondrocytes after dynamic hydrostatic pressure (dHP). dHP protocols (0.1 Hz, 2 MPa) were applied. The variation in type II collagen (Col II) expression induced by each dHP unit was measured. The dynamic remodeling of F-actin during the mechanical protocols was observed morphologically and mechanically by laser confocal microscopy and optical magnetic twisting cytometry (OMTC), respectively. About 20 ng/ml VEGF was used to stabilize the F-actin and restrain the mechanical refractory period. Compared with the remarkable increase of Col II (16-fold) induced by the initial dHP unit, the chondrocytes entered a mechanical refractory period and the second unit hardly elevated Col II expression (only 2.9-fold). This refractory period recovered partially within 2 h. The uniform, parallel, and coarse fibers of F-actin before dHP became thin, sparse, and disordered, and the cell stiffness decreased concomitantly. The variations in both the morphology and the mechanical property of F-actin were highly synchronous to the mechanical refractory period and recovered in a time-dependent manner. VEGF postponed the appearance of this refractory period and maintained the high expression of Col II by VEGF/p38/MAPKAPK-2/LIMK/cofilin pathway. A mechanical refractory period of chondrocytes has been discovered and defined in this study. The F-actin depolymerization is the putative mechanism, and this refractory period can be postponed by VEGF-induced F-actin stabilization.

  7. 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.

  8. Barbiturate-refractory epilepsy: safe schedule for therapeutic substitution

    OpenAIRE

    Gorz, Ana Maria; Silvado, Carlos E. S.; Bittencourt, Paulo Rogério M.

    1986-01-01

    Barbiturates are considered first line antiepileptic drugs in third world countries due to traditional and economic reasons. This prospective uncontrolled study of 52 patients aged 15 to 64 years (mean 24) demonstrates that patients who become refractory to barbiturates are mainly those with partial seizures with or without generalization or with a focal EEG abnormality (71%). Seizures tend to become refractory approximately 6 years after barbiturates were started. Progressive barbiturate wit...

  9. Silica crown refractory corrosion in glass melting furnaces

    OpenAIRE

    Balandis A.; Nizeviciene D.

    2011-01-01

    The critical parameters of silica refractories, such as compressive strength, bulk, density, quantity of silica, microstructure and porosity were evaluated of unused and used bricks to line the crowns of glass furnaces, when the rate of corrosion of crowns were about 2 times greater. The change of these parameters, the chemical composition and formation of the microcracks in the used silica refractories material were studied. It was established that the short time at service of containe...

  10. The Use Of Phosphates To Reduce Slag Penetration In Cr203-Based Refractories

    Science.gov (United States)

    Kwong, Kyei-Sing; Dogan, Cynthia P.; Bennett, James P.; Chinn, Richard E.; Petty, Arthur V.

    2004-11-09

    A high-chromium refractory material that provides improved resistance to coal slag penetration is presented. The refractory mixture comprises a blend of chromium oxide, aluminum oxide and phosphates. The refractory mixture may be blended with an aggregate and cured. In addition a phosphorous oxide may be blended with chromium oxide and aluminum oxide and additionally an aggregate. The refractory mixture reduces the rate of coal slag penetration into the surface of the cured refractory.

  11. Use of phosphates to reduce slag penetration in Cr2O3-based refractories

    Energy Technology Data Exchange (ETDEWEB)

    Kwong, Kyei-Sing; Dogan, Cynthia P.; Bennett, James P.; Chinn, Richard E.; Petty, Arthur V.

    2004-11-09

    A high-chromium refractory material that provides improved resistance to coal slag penetration is presented. The refractory mixture comprises a blend of chromium oxide, aluminum oxide and phosphates. The refractory mixture may be blended with an aggregate and cured. In addition a phosphorous oxide may be blended with chromium oxide and aluminum oxide and additionally an aggregate. The refractory mixture reduces the rate of coal slag penetration into the surface of the cured refractory.

  12. Use of Phosphates to Reduce Slag Penetration in CR203-Based Refractories

    Energy Technology Data Exchange (ETDEWEB)

    Kwong, Kyei-Sing; Dogan, Cynthia P.; Bennett, James P.; Chinn, Richard E.; Petty, Arthur V.

    2004-11-09

    A high-chromium refractory material that provides improved resistance to coal slag penetration is presented. The refractory mixture comprises a blend of chromium oxide, aluminum oxide and phosphates. The refractory mixture may be blended with an aggregate and cured. In addition a phosphorus oxide may be blended with chromium oxide and aluminum oxide and additionally an aggregate. The refractory mixture reduces the rate of coal slag penetration into the surface of the cured refractory.

  13. Chronic lymphocytic leukemia: treatment options for patients with refractory disease.

    Science.gov (United States)

    Motta, Marina; Wierda, William G; Ferrajoli, Alessandra

    2009-09-01

    Patients with purine analogue-refractory chronic lymphocytic leukemia (CLL) have short survival and limited treatment options. Defining the best salvage strategies for this population is challenging, because limited data are available from clinical trials, and because studies have enrolled mixed populations (patients with recurrent and refractory disease or patients with refractory disease and Richter transformation). Moreover, patients with refractory CLL have a high incidence of unfavorable molecular and clinical features, such as high-risk genomic profiles, unmutated immunoglobulin heavy-chain genes, expression of zeta-chain-associated protein kinase 70, and bulky lymphadenopathies. These patients are also severely immunosuppressed because of the underlying disease and the treatments received, and experience a high rate of infectious complications that pose an additional difficulty in selecting treatment. Despite these challenges, in parallel with better characterizations of the biologic features of refractory CLL, the number of available treatment modalities for this population has increased. Several chemoimmunotherapy combinations have been developed, and novel agents with a different mechanism of action are being investigated in clinical trials. Furthermore, allogeneic stem cell transplantation with nonmyeloablative conditioning regimens is a therapeutic strategy that is increasingly offered to patients with refractory CLL.

  14. Recycling practices of spent MgO-C refractories

    Energy Technology Data Exchange (ETDEWEB)

    Kwong, Kyei-Sing; Bennett, James P.

    2002-10-01

    The recycling options of spent MgO-C refractories from an electrical arc furnace (EAF) have been evaluated. The economic, quality of spent refractories and products made from it, the ease of implementation of a recycling practice and the interest of steel melt shops were considered. It was decided that the best option of most EAF shops would be to recycle spent MgO-C refractory as a foaming slag conditioner because of their MgO content. Crushed MgO-C spent refractories can be reused directly back into an EAF without complex and costly beneficiation. Even though this practice is simple, it is critical to know the optimum amount of MgO in the slag to achieve the best foaming quality. A computer model was designed to find the optimum MgO amount. This modeling also helps the melt shop extend refractory service life, increase the energy efficiency, increase productivity, and decrease the amount of slag. Issues related to the refractory recycling will be discussed.

  15. Electron microscopy study of refractory ceramic fibers.

    Science.gov (United States)

    MacKinnon, P A; Lentz, T J; Rice, C H; Lockey, J E; Lemasters, G K; Gartside, P S

    2001-10-01

    In epidemiological studies designed to identify potential health risks of exposures to synthetic vitreous fibers, the characterization of airborne fiber dimensions may be essential for assessing mechanisms of fiber toxicity. Toward this end, air sampling was conducted as part of an industry-wide study of workers potentially exposed to airborne fibrous dusts during the manufacture of refractory ceramic fibers (RCF) and RCF products. Analyses of a subset of samples obtained on the sample filter as well as on the conductive sampling cowl were performed using both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to characterize dimensions of airborne fibers. Comparison was made of bivariate fiber size distributions (length and diameter) from air samples analyzed by SEM and by TEM techniques. Results of the analyses indicate that RCF size distributions include fibers small enough in diameter (fibers (> 60 microm) may go undetected by TEM, as evidenced by the proportion of fibers in this category for TEM and SEM analyses (1% and 5%, respectively). Limitations of the microscopic techniques and differences in fiber-sizing rules for each method are believed to have contributed to the variation among fiber-sizing results. It was concluded from these data that further attempts to characterize RCF exposure in manufacturing and related operations should include analysis by TEM and SEM, since the smallest diameter fibers are not resolved with SEM and the fibers of longer length are not sized by TEM.

  16. [Clinical features of atypical refractory anemia (RA)].

    Science.gov (United States)

    Matsuda, A; Jinnai, I; Kusumoto, S; Shiramatsu, F; Bessho, M; Saito, M; Hirashima, K

    1991-08-01

    Twenty-three patients with bicytopenia or pancytopenia were retrospectively studied. The patients with underlying disorders, blast count of more than 5% on bone marrow (BM) aspirate, blast count of more than 1% on peripheral blood or ringed sideroblast count of more than 15% on BM aspirate were excluded. According to Yoshida's criteria, 23 patients were classified into 6 subtypes [AA (aplastic anemia)1: typical AA, AA2: atypical AA, MDS (myelodysplastic syndrome)3: typical RA (refractory anemia, MDS4-6: atypical RA], and AA1 7 cases; AA2 2 cases; MDS3 5 cases; MDS4 1 case; MDS5 2 cases; MDS6 6 cases. To clarify the clinical features of atypical RA group (MDS4-6), we investigated ferrokinetics, RBC life span, karyotype, serum Epo (erythropoietin) concentration, response to therapy and prognosis. Results were as follows: 1) all three RA patients who were younger than 30 years old were included in atypical RA group, 2) in ferrokinetics study PID (plasma iron disappearance time) values of MDS4 and MDS6 patients ranged between those of AA1 and those of MDS3 patients (5 of 7 patients), 3) two cases who developed leukemia belonged to typical RA group, 4) patients with atypical RA showed response to therapy and their prognosis were better than those with typical RA. These observations suggest that atypical RA have different clinical features from typical RA.

  17. Efficacy of levetiracetam in refractory childhood epilepsy

    Directory of Open Access Journals (Sweden)

    Keon Su Lee

    2010-04-01

    Full Text Available Purpose : To evaluate the efficacy and safety of levetiracetam adjunctive therapy for reducing the rate of seizure frequency in children with intractable pediatric epilepsy. Methods : We reviewed the medical records of 86 patients with intractable pediatric epilepsy who visited our hospital between March 1989 and February 2009. Levetiracetam was included in the previous anticonvulsant regimen for at least 6 months and the reduction in the rate of seizure frequency was determined in follow-up examinations. We analyzed demographic data, seizure types, antiepileptic drug history, levetiracetam dose, adverse effects of levetiracetam therapy, treatment outcome, electroencephalogram findings, etc. Results : More than 50% reduction in the seizure frequency was observed in 62 of the 86 (72.1% patients; 44 patients (51.1% became seizure free, while the seizure frequency increased in 5.8% patients. The associations between seizure reduction rate and age, associated diseases, seizure types, and seizure frequency before treatment were not significant. However, the duration of disease, dose of levetiracetam, duration and frequency of anticonvulsant administration before levetiracetam therapy were significantly correlated. Electroencephalogram findings and the cause of epilepsy showed partial correlation. Forty (46% patients showed adverse symptoms; the symptoms in the order of their frequency were somnolence, hyperactivity, irritability, aggressiveness, tiredness, etc. Conclusion : The findings of our study provide the evidence that levetiracetam adjunctive therapy is efficacious and well tolerated in various refractory childhood epilepsy cases.

  18. Flavopiridol and Vorinostat in Treating Patients With Relapsed or Refractory Acute Leukemia or Chronic Myelogenous Leukemia or Refractory Anemia

    Science.gov (United States)

    2013-04-01

    Blastic Phase Chronic Myelogenous Leukemia; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Refractory Anemia With Excess Blasts; Relapsing Chronic Myelogenous Leukemia; Untreated Adult Acute Lymphoblastic Leukemia; Untreated Adult Acute Myeloid Leukemia

  19. System and process for aluminization of metal-containing substrates

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Yeong-Shyung; Stevenson, Jeffry W.

    2017-12-12

    A system and method are detailed for aluminizing surfaces of metallic substrates, parts, and components with a protective alumina layer in-situ. Aluminum (Al) foil sandwiched between the metallic components and a refractory material when heated in an oxidizing gas under a compression load at a selected temperature forms the protective alumina coating on the surface of the metallic components. The alumina coating minimizes evaporation of volatile metals from the metallic substrates, parts, and components in assembled devices that can degrade performance during operation at high temperature.

  20. Quantification and localization of trace metals in natural plancton using a synchrotron x-ray fluorescence microprobe.

    Energy Technology Data Exchange (ETDEWEB)

    Twining, B. S.; Baines, S. B.; Fisher, N. S.; Jacobsen, C.; Maser, J.; State Univ. of New York at Stony Brook

    2003-03-01

    The accumulation of trace metals by planktonic protists influences the growth of primary producers, metal biogeochemical cycling, and metal bioaccumulation in aquatic food chains. Despite their importance, unequivocal measurements of trace element concentrations in individual plankton cells have not been possible to date. We have used the 2-ID-E side-branch hard x-ray microprobe at the Advanced Photon Source to measure trace elements in individual marine plankton cells. This microprobe employs zoneplate optics to produce the sub-micron spatial resolution and low background fluorescence required to produce trace element maps of planktonic protist cells ranging in size from 3 to >50 {micro}m. We have developed preservation, rinsing, and mounting protocols that remove most of the salt from our marine samples, thus simplifying the identification of unknown cells and reducing high Cl-related background fluorescence. We have also developed spectral modeling techniques that account for the frequent overlap of adjacent fluorescence peaks and non-uniform detector response. Finally, we have used parallel soft x-ray transmission and epifluorescence microscopy images to estimate C normalized trace element concentrations, identify functional cell types (e.g., photosynthetic vs. non-photosynthetic), and correlate cell structures with spatial patterns in trace element fluorescence.

  1. Heterogeneous catalytic wet air oxidation of refractory organic pollutants in industrial wastewaters: a review.

    Science.gov (United States)

    Kim, Kyoung-Hun; Ihm, Son-Ki

    2011-02-15

    Catalytic wet air oxidation (CWAO) is one of the most economical and environmental-friendly advanced oxidation process. It makes a promising technology for the treatment of refractory organic pollutants in industrial wastewaters. Various heterogeneous catalysts including noble metals and metal oxides have been extensively studied to enhance the efficiency of CWAO. The present review is concerned about the literatures published in this regard. Phenolics, carboxylic acids, and nitrogen-containing compounds were taken as model pollutants in most cases, and noble metals such as Ru, Rh, Pd, Ir, and Pt as well as oxides of Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, and Ce were applied as heterogeneous catalysts. Reports on their characterization and catalytic performances for the CWAO of aqueous pollutants are reviewed. Discussions are also made on the reaction mechanisms and kinetics proposed for heterogeneous CWAO and also on the typical catalyst deactivations in heterogeneous CWAO, i.e. carbonaceous deposits and metal leaching. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Probiotics and refractory chronic spontaneous urticaria.

    Science.gov (United States)

    Nettis, E; Di Leo, E; Pastore, A; Distaso, M; Zaza, I; Vacca, M; Macchia, L; Vacca, A

    2016-09-01

    Background. In chronic spontaneous urticaria (CSU) first-line therapy with an antihistamine-based regimen may not achieve satisfactory control in patients. Thus, a continuing need exists for effective and safe treatments for refractory CSU. Aim. To evaluate the clinical efficacy and safety of an intake of a combination of 2 probiotics (Lactobacillus salivarius LS01 and Bifidobacterium breve BR03) in patients with CSU who remain symptomatic despite concomitant H1-antihistamine therapy. Methods. This report analyzes the effects of therapy with two probiotic strains on the clinical progress of 52 unselected patients with difficulty to treat CSU underwent to medical examination in two Italian specialist urticaria Clinics between September 2013 and September 2014. A mixture of Lactobacillus LS01 and Bifidobacterium BR03 were administered in each patient twice daily for 8 weeks. To evaluate patients' improvement with probiotics, urticaria activity score over 7 days (UAS7) was used at baseline and at week 8 in addition to a 5-question urticaria quality of life questionnaire. Results. Fifty-two patients with CSU were included in this study (10 male and 42 female, age range 19-72 years). Mean disease duration was 1.5 years. Fourteen patients discontinued treatment, so evaluable population consisted of 38 patients. Nine of the 38 patients experienced mild clinical improvement during probiotic treatment (23.7%); one patient reported significant clinical improvement (2.6%) and one patient had complete remission of urticaria (2.6%). Twenty-seven patients did not have improvement in symptoms (71.1%). No side effects during the course of therapy were reported. Conclusions. A combination of Lactobacillus salivarius LS01 and Bifidobacterium breve BR03 administered twice daily for 8 weeks might reduce the symptoms scores and improve quality of life scores in a part of patients with CSU who remained symptomatic despite treatment with H1 antihistamine mostly in subjects with allergic

  3. Organically bound sulfur in refractory organic substances.

    Science.gov (United States)

    Abbt-Braun, G; Jahnel, J B

    2001-11-01

    The sulfur compounds of refractory organic substances (ROS) of different origin have been characterized. Total organic sulfur was determined by elemental analysis. Sulfur-containing amino acids methionine and cystine were analyzed chromatographically after hydrolysis with HCl or by proteolytic digestion using enzymes. The results obtained from elemental analysis show that the total amount of sulfur is strongly dependent on the origin of the samples, because of different environmental factors during the formation of ROS. For naturally occurring samples isolated from soil seepage water, bog lake water and ground water the carbon-to-sulfur atomic ratios (C/S) decrease with the stage of humification, because of preferential loss of carbon. In humic acids (HA) isolated from secondary effluent the high value of the nitrogen-to-sulfur ratio (N/S) was indicative of a large amount of protein-derived nitrogen and sulfur compounds. In the solutions from acid hydrolysis the total amount of amino acid carbon related to the dissolved organic carbon (DOC) was generally less than 5%. Percentages of cystine related to all the amino acids detected were in the range 4 to 16%; methionine was below the detection limit for most samples. The results show that cystine is very important among the amino acids released. Enzymatic release generally resulted in smaller amounts of amino acids, indicating that these molecules are not only present in bioavailable protein-like structures. The data were compared with those from other approaches reported in the literature for the speciation of sulfur forms in ROS, including potentiometric titration, differential reduction methods, and spectroscopic investigations.

  4. Intrathecal ziconotide for refractory chronic pain.

    Science.gov (United States)

    Lynch, Shalini S; Cheng, Christine M; Yee, Jennie L

    2006-01-01

    To describe the pharmacology, efficacy, and safety of ziconotide for treatment of severe chronic pain in patients who are candidates for intrathecal therapy. A PubMed/MEDLINE search (1966-June 2006) was conducted using the terms ziconotide, Prialt, and SNX-111. Manufacturer-provided data, the Food and Drug Administration medical review of ziconotide, and abstracts presented at American Pain Society meetings (2001-2006) were also reviewed. Human studies evaluating the efficacy and safety of ziconotide for the treatment of chronic pain were considered. Animal data were excluded. Ziconotide is the first and only neuronal-type (N-type) calcium-channel blocker. Ziconotide must be administered intrathecally via continuous infusion. A programmable implanted variable-rate microinfusion device, or an external microinfusion device and catheter must be utilized. In double-blind, placebo-controlled studies, ziconotide significantly improved patient perception of pain from baseline to the end of the study periods, which ranged from 11 to 21 days. Patients enrolled in clinical trials were intolerant of or refractory to other treatment modalities. There have been no studies that directly compared ziconotide with other intrathecal or systemic analgesics. Key ziconotide-related adverse events are neuropsychiatric, including depression, cognitive impairment, and hallucinations; depressed levels of consciousness; and elevation of creatine kinase levels. Ziconotide is also associated with a risk of meningitis due to possible contamination of the microinfusion device. Ziconotide is a therapeutic option for treatment of severe chronic pain in patients who have exhausted all other agents, including intrathecal morphine, and for whom the potential benefit outweighs the risks of serious neuropsychiatric adverse effects and of having an implanted device. Further studies are needed to determine the comparative efficacy of ziconotide and other pain therapies.

  5. [Early identification of refractory Mycoplasma pneumoniae pneumonia in children].

    Science.gov (United States)

    Wang, Zhen; Li, Ya-Chun; Chen, Lu

    2015-11-01

    To investigate the clinical indicators for early identification of refractory Mycoplasma pneumoniae pneumonia (RMPP) in children. The clinical data of 142 children with Mycoplasma pneumoniae pneumonia (MPP) between January 2014 and June 2015 were retrospectively studied. Among the 142 children, there were 32 cases of RMPP and 110 cases of non-refractory MPP. The clinical data were compared between the RMPP and non-refractory MPP groups. The percentage of school-age children in the RMPP group was higher than in the non-refractory MPP group (Prefractory MPP group (Prefractory MPP children (Prefractory MPP children (Prefractory MPP group (P40 mg/L and ESR>30 mm/h+LDH>300 IU/L than the non-refractory MPP group (P<0.05). RMPP is common in school-age children. Consolidation of lung on chest X-Ray, pleural effusion and increased levels of CRP and ESR+LDH may be helpful to early identification of RMPP in children.

  6. Aerosol Chemical Speciation Monitor (ACSM) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Thomas B. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-08-15

    The Aerodyne Aerosol Chemical Speciation Monitor (ACSM) measures particle mass loading and chemical composition in real time for non-refractory sub-micron aerosol particles. The ACSM is designed for long-term unattended deployment and routine monitoring applications.

  7. System and method for producing metallic iron

    Energy Technology Data Exchange (ETDEWEB)

    Englund, David J.; Schlichting, Mark; Meehan, John; Crouch, Jeremiah; Wilson, Logan

    2014-07-29

    A method of production of metallic iron nodules comprises assembling a hearth furnace having a moveable hearth comprising refractory material and having a conversion zone and a fusion zone, providing a hearth material layer comprising carbonaceous material on the refractory material, providing a layer of reducible material comprising and iron bearing material arranged in discrete portions over at least a portion of the hearth material layer, delivering oxygen gas into the hearth furnace to a ratio of at least 0.8:1 ponds of oxygen to pounds of iron in the reducible material to heat the conversion zone to a temperature sufficient to at least partially reduce the reducible material and to heat the fusion zone to a temperature sufficient to at least partially reduce the reducible material, and heating the reducible material to form one or more metallic iron nodules and slag.

  8. Refractoriness of on extended movement to directional change.

    Science.gov (United States)

    Williams, L R

    1971-12-01

    An extended movement was used to compare the memory-drum and single-channel definitions of psychological refractoriness. The basic movement In response to the first signal (S1) was a forward lunge and a concurrent arm swing through a target string. The response to the second signal (S2) was a reversal of the original movement The interstimulus Interval (ISI) ranged from .10 - .70 sec. in .10-sec. steps. The hypothesis that refractoriness of the reversal movement would decrease as ISI shortened was confirmed by the fact that error frequencies decreased significantly and substantially with decreasing IS I. The availability of some residual capacity to deal with S2 during the refractory period was also indicated by an examination of the relationship between RT2 and the interval between S2 and RT1. This departure from the classical single-channel model shows some agreement with the neuromotor-programming theory.

  9. Decompressive laparotomy for refractory intracranial hypertension after traumatic brain injury.

    Science.gov (United States)

    Dorfman, Jon D; Burns, Joseph D; Green, Deborah M; DeFusco, Christina; Agarwal, Suresh

    2011-12-01

    Intracranial hypertension is a crucial modifiable risk factor for poor outcome after traumatic brain injury (TBI). Limited evidence suggests that decompressive laparotomy may be an effective treatment for refractory ICH in patients who have elevated intra-abdominal pressure. Case report. We present a multi-trauma patient who sustained severe TBI in a motor vehicle collision. Intracranial pressure (ICP) was initially medically managed but became refractory to standard therapies. Emergent decompressive laparotomy performed in the surgical intensive care unit for abdominal compartment syndrome concomitantly improved the patient's ICP. Elevated intra-abdominal pressure can exacerbate intracranial hypertension in patients with TBI. Recognition of this condition and treatment with decompressive laparotomy may be useful in patients with intracranial hypertension refractory to optimal medical therapy.

  10. 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.

  11. 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.

  12. Using low porosity refractory materials in coke ovens

    Energy Technology Data Exchange (ETDEWEB)

    Narita, Y.; Sudzuki, T.

    1982-02-19

    Refractory bricks with porosity (KP) of less than or equal to 17 percent, which contain less than 1 percent iron oxide and are resiliant at temperatures of more than 1,000/sup 0/C, are made through caking or electrosmelting of materials with a high aluminum content (chamotte, sillimanite, cordierite, pagodite) and silicon content (magnesial chromite, alumina, magnesite, calcite and zircon). In a refractory material with a seeming porosity of less than or equal to 17 percent the deposition of carbon in the pores is reduced which promotes a constant heat conductivity and strength of the refractory material in the operation of coke ovens. Normally the carbon is formed with the reduction of CO under the catalytic action of iron oxide.

  13. An unusual cause of refractory hypoxemia in cirrhosis.

    Science.gov (United States)

    Patidar, Yashwant; Kumar, Sachin

    2015-03-01

    Pulmonary gas exchange abnormalities and refractory hypoxemia cause myriad difficulties in patients with chronic liver disease. In addition to intrinsic cardiopulmonary diseases and hepatopulmonary syndrome, some unusual pathophysiological mechanisms in patients with portosystemic collaterals might contribute to hypoxemia. We report the clinical presentation of an unusual portosystemic anatomic shunt that permits venous admixture with oxygenated blood, causing hypoxemia that is refractory to the administration of supplemental oxygen, and recurrent hepatic encephalopathy. There has been no such report in the published literature. This case highlights the importance of keeping direct portopulmonary venous anastomosis in the differential diagnosis of oxygen-refractory hypoxemia and recurrent hepatic encephalopathy in patients with cirrhosis in the appropriate clinical context. Copyright © 2015 by Daedalus Enterprises.

  14. Propofol in the treatment of refractory migraine headaches.

    Science.gov (United States)

    Dhir, Ashish

    2016-09-01

    Refractory/intractable migraine headaches are associated with chronic pain that does not respond to standard care of treatment. Propofol(2,6-diisopropylphenol) in sub-anesthetic doses has been reported to be beneficial in such patients. The present article describes the complete drug profile of propofol in the management of these super-refractory migraine headaches. The article covers different preclinical and clinical studies available in the literature. Expert commentary: Propofol is useful as an off-label drug molecule in an emergency situation of refractory migraines where it has been found to reduce the pain intensity. The molecule with a narrow therapeutic index and high abuse potential is prescribed only when conventional drugs fail to deliver any relief. There are not adequate double-blind crossover studies that substantiate the effectiveness of propofol in the treatment of migraine headaches. Furthermore, long-term outcomes for the use of propofol in migraine headaches requires an extensive investigation.

  15. Development of Cost-Effective Low-Permeability Ceramic and Refractory Components for Aluminum Melting and Casting

    Energy Technology Data Exchange (ETDEWEB)

    Kadolkar, Puja [ORNL; Ott, Ronald D [ORNL

    2006-02-01

    A recent review by the U.S. Advanced Ceramics Association, the Aluminum Association, and the U.S. Department of Energy's Office of Industrial Technologies (DOE/OIT) described the status of advanced ceramics for aluminum processing, including monolithics, composites, and coatings. The report observed that monolithic ceramics (particularly oxides) have attractive properties such as resistance to heat, corrosion, thermal shock, abrasion, and erosion [1]. However, even after the developments of the past 25 years, there are two key barriers to commercialization: reliability and cost-effectiveness. Industry research is therefore focused on eliminating these barriers. Ceramic coatings have likewise undergone significant development and a variety of processes have been demonstrated for applying coatings to substrates. Some processes, such as thermal barrier coatings for gas turbine engines, exhibit sufficient reliability and service life for routine commercial use. Worldwide, aluminum melting and molten metal handling consumes about 506,000 tons of refractory materials annually. Refractory compositions for handling molten aluminum are generally based on dense fused cast silica or mullite. The microstructural texture is extremely important because an interlocking mass of coarser grains must be bonded together by smaller grains in order to achieve adequate strength. At the same time, well-distributed microscopic pores and cracks are needed to deflect cracks and prevent spalling and thermal shock damage [2]. The focus of this project was to develop and validate new classes of cost-effective, low-permeability ceramic and refractory components for handling molten aluminum in both smelting and casting environments. The primary goal was to develop improved coatings and functionally graded materials that will possess superior combinations of properties, including resistance to thermal shock, erosion, corrosion, and wetting. When these materials are successfully deployed in

  16. DEVELOPMENT OF A HIGH TEMPERATURE LIQUID METAL SOLUTION CALORIMETER.

    Science.gov (United States)

    alloys and many inorganic compounds, including such materials as steels, refractory metal alloys, carbides, borides , and silicides. Because of the high...alumina is used for other parts. Heat is supplied through molybdenum wire resistance windings and controlled by a proportioning controller. Temperatures

  17. High Temperature Reactions of Uranium Dioxide with Various Metal Oxides

    Science.gov (United States)

    1956-02-20

    difficulties described in (2) and (3). However, sagging of the helix, blocking the line of sight, was a troublesome problem . REFRACTORY METAL HEATER...Jr., Uranium oxide phase equilibrium systems: IV, UOr- ThOg , J. Am. Ceram. Soc. 36, 397 (1953). [20] H. von Wartenberg and E. Prophet, Melting diagrams

  18. 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.

  19. Metal-metal-hofteproteser

    DEFF Research Database (Denmark)

    Ulrich, Michael; Overgaard, Søren; Penny, Jeannette

    2014-01-01

    In Denmark 4,456 metal-on-metal (MoM) hip prostheses have been implanted. Evidence demonstrates that some patients develope adverse biological reactions causing failures of MoM hip arthroplasty. Some reactions might be systemic. Failure rates are associated with the type and the design of the Mo...

  20. The Utility of Cannabidiol in the Treatment of Refractory Epilepsy.

    Science.gov (United States)

    Reddy, D S

    2017-02-01

    Cannabis-derived cannabinoids such as cannabidiol (CBD) have anticonvulsant properties. Recently, there has been an emerging interest in the use of CBD-enriched products for treatment of drug-resistant epilepsy. Some pilot trials of CBD have proved beneficial for refractory epilepsy, but its efficacy is yet to be confirmed by standard placebo-controlled trials. However, the mechanisms underlying the seizure protection efficacy claims of CBD remain unclear. This review briefly describes the clinical utility of CBD in the treatment of refractory epilepsy. © 2016 American Society for Clinical Pharmacology and Therapeutics.

  1. 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.

  2. Amantadine for the treatment of refractory absence seizures in children.

    Science.gov (United States)

    Perry, M Scott; Bailey, Laurie J; Kotecha, Amy C; Malik, Saleem I; Hernandez, Angel W

    2012-04-01

    Amantadine has demonstrated efficacy in small series for absence and myoclonic type seizures. We examined the efficacy of amantadine for treating refractory absence seizures in a cohort of pediatric patients. We retrospectively reviewed medical records for patients with absence seizures treated with amantadine at Cook Children's Medical Center after January 2007. Abstracted data included sex, age at initiation, concomitant antiepileptic drugs, amantadine dosing, and seizure frequency. Outcomes at 3, 6, and 12 months after initiation were categorized as >90%, ≥50%, or 90% reduction in seizure frequency. Amantadine may constitute an efficacious alternative treatment for refractory absence seizures. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Influence of the phase composition of refractory materials on creep

    Directory of Open Access Journals (Sweden)

    Terzić A.

    2006-01-01

    Full Text Available In this paper, the relationship between the creeping effect and mineralogical characteristics of the applied binding phase for various refractory materials (high-alumina materials, with high or low impurity content, tar bonded either magnesite or dolomite materials and silicate bonded chrom-magnesite materials is presented. The mechanism of creeping is analyzed and the activation energy for creep for each investigated material is obtained and discussed. All investigated materials are creep sensitive under investigated conditions and have similar activation energies for creep except high-alumina refractories with a low impurity content.

  4. Refractory High-Entropy Alloys (Preprint)

    Science.gov (United States)

    2011-07-01

    the equimolar mixtures of the corresponding elements. High purity titanium was used as a getter for residual gases in the high vacuum chamber. The...tungsten, molybdenum and vanadium were in the form of 45.7 mm diameter rods with a purity of 99.7%, 99.0% and 99.9%, respectively. The tantalum and...15.6 9.08 / 21.0 Table 2. The crystal lattice parameter, a, density, ρ, and Vickers hardness, Hv, of high purity W, Nb, Mo, Ta and V metals, and

  5. 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

  6. Ascorbic Acid and Combination Chemotherapy in Treating Patients With Relapsed or Refractory Lymphoma

    Science.gov (United States)

    2018-01-25

    High Grade B-Cell Lymphoma With MYC and BCL2 or BCL6 Rearrangements; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Hodgkin Lymphoma; Recurrent Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Lymphoma

  7. 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.

  8. Metallated metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

    2017-08-22

    Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

  9. Metallated metal-organic frameworks

    Science.gov (United States)

    Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

    2017-02-07

    Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

  10. Iron-Refractory Iron Deficiency Anemia

    Directory of Open Access Journals (Sweden)

    Ebru Yılmaz Keskin

    2015-03-01

    Full Text Available Demir, oksijenin taşınması, DNA sentezi ve hücre çoğalması gibi çeşitli biyolojik reaksiyonlar için vazgeçilmez olduğundan, yaşam için zorunludur. Demir metabolizması ve bu elementin düzenlenmesiyle ilgili bilgilerimiz, son yıllarda belirgin şekilde değişmiştir. Demir metabolizması ile ilgili yeni bozukluklar tanımlanmış ve demirin başka bozuklukların kofaktörü olduğu anlaşılmaya başlamıştır. Hemokromatozis ve demir tedavisine dirençli demir eksikliği anemisi (IRIDA; “iron-refractory iron deficiency anemia” gibi genetik durumlar üzerinde yapılan çalışmalar, vücuttaki demir dengesini kontrol eden moleküler mekanizmalar ile ilgili önemli ipuçları sunmuştur. Bu ilerlemeler, gelecekte, hem genetik hem de kazanılmış demir bozukluklarının daha etkili şekilde tedavi edilmesi amacıyla kullanılabilir. IRIDA, demir eksikliği ile giden durumlarda, hepsidin üretimini baskılayan matriptaz-2’yi kodlayan TMPRSS6 genindeki mutasyonlardan kaynaklanmaktadır. Hastalığın tipik özellikleri, hipokrom, mikrositer anemi, çok düşük ortalama eritrosit hacmi, oral demir tedavisine yanıtsızlık (veya yetersiz yanıt ve parenteral demire kısmi yanıttır. Klasik demir eksikliği anemisinin aksine, serum ferritin değeri genellikle hafif düşük ya da normal aralıkta; serum ve idrar hepsidin değerleri ise, aneminin derecesi ile orantısız şekilde yüksek bulunur. Şimdiye kadar literatürde bildirilmiş olguların sayısı 100’ü geçmediği halde, IRIDA’nın, “atipik” mikrositik anemilerin en sık nedeni olduğu düşünülmektedir. Bu derlemenin amacı, IRIDA hakkındaki güncel bilgileri araştırıcılar ile paylaşmak ve bu alandaki farkındalıklarını arttırmaktır.

  11. Diffusion of Siderophile Elements in Fe Metal: Application to Zoned Metal Grains in Chondrites

    Science.gov (United States)

    Righter, K.; Campbell, A. J.; Humajun, M.

    2003-01-01

    The distribution of highly siderophile elements (HSE) in planetary materials is controlled mainly by metal. Diffusion processes can control the distribution or re-distribution of these elements within metals, yet there is little systematic or appropriate diffusion data that can be used to interpret HSE concentrations in such metals. Because our understanding of isotope chronometry, redox processes, kamacite/taenite-based cooling rates, and metal grain zoning would be enhanced with diffusion data, we have measured diffusion coefficients for Ni, Co, Ga, Ge, Ru, Pd, Ir and Au in Fe metal from 1200 to 1400 C and 1 bar and 10 kbar. These new data on refractory and volatile siderophile elements are used to evaluate the role of diffusional processes in controlling zoning patterns in metal-rich chondrites.

  12. Corrosion Resistances of Cr-Free Refractories to Copper Smelting Slags

    Science.gov (United States)

    Chen, Mao; Chen, Junhong; Zhao, Baojun

    Appropriate selection of refractories for high temperature processes is vital to the production. Magnesia-chromite refractory has been widely used in copper making industry. However, the risk of generating high poisonous Cr6+ drives the researchers to find Cr-free refractories for copper industry.

  13. Effects of slag composition and process variables on decontamination of metallic wastes by melt refining

    Energy Technology Data Exchange (ETDEWEB)

    Heshmatpour, B.; Copeland, G. L.

    1981-01-01

    Melt refining has been suggested as an alternative for decontamination and volume reduction of low-level-contaminated metallic wastes. Knowledge of metallurgical and thermochemical aspects of the process is essential for effective treatment of various metals. Variables such as slag type and composition, melting technique, and refractory materials need to be identified for each metal or alloy. Samples of contaminated metals were melted with fluxes by resistance furnace or induction heating. The resulting ingots as well as the slags were analyzed for their nuclide contents, and the corresponding partition ratios were calculated. Compatibility of slags and refractories was also investigated, and proper refractory materials were identified. Resistance furnace melting appeared to be a better melting technique for nonferrous scrap, while induction melting was more suitable for ferrous metals. In general uranium contents of the metals, except for aluminum, could be reduced to as low as 0.01 to 0.1 ppM by melt refining. Aluminum could be decontaminated to about 1 to 2 ppM U when certain fluoride slags were used. The extent of decontamination was not very sensitive to slag type and composition. However, borosilicate and basic oxidizing slags were more effective on ferrous metals and Cu; NaNO/sub 3/-NaCl-NaOH type fluxes were desirable for Zn, Pb, and Sn; and fluoride type slags were effective for decontamination of Al. Recrystallized alumina proved to be the most compatible refractory for melt refining both ferrous and nonferrous metals, while graphite was suitable for nonferrous metal processing. In conclusion, melt refining is an effective technique for volume reduction ad decontamination of contaminated metal scrap when proper slags, melting technique, and refractories are used.

  14. POST-MORTEM CHARACTERISATION OF ALUMINA-C REFRACTORY BRICKS WITH ORGANIC BOND FROM STEEL PRODUCTION: POTENTIALITY OF Al₂O₃ - MATERIAL RECOVERY

    Directory of Open Access Journals (Sweden)

    Beatrice Plesingerova

    2017-07-01

    Full Text Available The paper describes the post-mortem characterisation of spent class AC 70/5 refractory linings from steel ladles, focuses on the environmental impact of their dumping, and points to possibilities of reusing material that is less degraded by corrosion. The degradability of the spent refractories in water is an indicator of their degree of corrosion. Therefore the crushed refractory bricks were leached in water and a weakly acid medium (pH = 5.95 and 4.21, respectively. The pH value, conductivity, redox potential and concentration of ions were measured in the leachates. New AC 70/5 material generates a pH value of leachates of around 8.5, while the alkalinity of leachates from spent brick material increases with the increasing content of lime-corroding compounds (pH = 10-12. Alkaline environments inhibit the release of heavy metal ions. Under the thin strongly corroded surface the refractory material deteriorates only slightly. When bricks are crushed, a redistribution of components into grainy fractions occurs. C and MgO are concentrated in the fine fraction (under 1 mm and Al₂O₃ in the coarse fractions (1-2.5 mm. In view of raw material prices it is desirable to proceed further with the recovery of grainy Al₂O₃.

  15. Aborted and refractory status epilepticus in children : A comparative analysis

    NARCIS (Netherlands)

    Lambrechtsen, Florise A. C. P.; Buchhalter, Jeffrey R.

    Purpose: The aims of this retrospective study were: (1) to compare the demographics, clinical characteristics, etiology, and EEG findings of status epilepticus aborted with medication (ASE) and refractory status epilepticus (RSE), (2) to describe the treatment response of status epilepticus (SE),

  16. Role of rectal myomectomy in refractory chronic constipation ...

    African Journals Online (AJOL)

    Background: To assess the role of diagnostic and therapeutic value of anorectal myectomy in cases of chronic refractory constipation. Materials and Methods: Twenty-eight patients 11 months to 9 years of age presenting with chronic constipation, with contrast enema showing dilated rectum and sigmoid colon were included ...

  17. Reserpine for the treatment of refractory mania | Eloff | South African ...

    African Journals Online (AJOL)

    We report a case of refractory mania treated successfully with reserpine. The patient was a 26-year-old man with bipolar I disorder, who had recurrent hospital admissions for manic episodes that failed to respond to multiple mood stabilisers and antipsychotics. The patient also suffered from hypertension. His manic ...

  18. A case of incomplete and refractory Kawasaki disease: Diagnostic ...

    African Journals Online (AJOL)

    The diagnosis of incomplete Kawasaki disease (KD) – i.e. cases that do not full all the diagnostic criteria – requires a high index of suspicion. We report a case of incomplete KD that was refractory to treatment with intravenous immunoglobulin and subsequently responded to treatment with intravenous methylprednisolone.

  19. Long-term outcomes of thalidomide in refractory Crohn's disease.

    Science.gov (United States)

    Gerich, M E; Yoon, J L; Targan, S R; Ippoliti, A F; Vasiliauskas, E A

    2015-03-01

    Several open-label and retrospective studies have indicated that thalidomide may be beneficial in patients with refractory Crohn's disease (CD). To report our long-term experience with the use of thalidomide for adults with refractory Crohn's disease. We conducted a retrospective study of long-term clinical and safety outcomes among adults treated with thalidomide for refractory Crohn's disease. Response was defined as a clinician's assessment of improvement after at least 7 days treatment of one or more of the following: bowel movement frequency, fistula output, rectal bleeding, abdominal pain, extraintestinal manifestations, or well-being. Remission required all of the following: thalidomide for a median of 4.4 months and followed up for a median of 58 months. Clinical response and remission rates were 54% and 19%, respectively. About 40% of patients were able to stop steroids. Response rates were higher for those treated with more than 50 mg/day (85%) than for those treated with a maximum of 50 mg/day (40%; P = 0.01). An adverse event occurred in 68% of patients. Approximately one-third of patients (38%) experienced neuropathy. Thalidomide appears to be safe and effective in some patients with refractory Crohn's disease. Although side effects may limit long-term use, thalidomide has potential to induce significant clinical responses. © 2014 John Wiley & Sons Ltd.

  20. Therapy of the refractory ascites: Total paracentesis vs. TIPS.

    Science.gov (United States)

    La Mura, Vincenzo; Salerno, Francesco

    2016-01-01

    This revision was aimed to report the evidences on the treatment of patients with cirrhosis and refractory ascites. Mainly, we wished to explore which of the predicting variables could be used to prefer large-volume paracentesis or TIPS. Copyright © 2015 Elsevier España, S.L.U. y AEEH y AEG. All rights reserved.

  1. 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.

  2. Performance Evaluation of Refractory Bricks produced from locally ...

    African Journals Online (AJOL)

    The performance evaluation of refractory bricks produced from some local clay deposits in Delta State, Nigeria was investigated. Four major sites in Delta State renowned for abundant clay deposits were selected, namely; Oghara, Ekpan, Ubeji and Jeddo. The clay samples were crushed, milled (pulverised) and sieved to ...

  3. Super Refractory Status Epilepticus: A Case Report from Livingstone ...

    African Journals Online (AJOL)

    Background: Status Epilepticus (SE) is defined as more than five minutes of persistent seizure activity without full recovery of consciousness in between the seizures. If SE fails to respond to two antiepileptic drugs, it is called refractory status epilepticus (RSE) and if it continues or recurs 24 hours after anesthesia, it is called ...

  4. [Refractory cardiac arrest patients in prehospital care, potential organ donors].

    Science.gov (United States)

    Le Jan, Arnaud; Dupin, Aurélie; Garrigue, Bruno; Sapir, David

    2016-09-01

    Under the authority of the French Biomedicine Agency, a new care pathway integrates refractory cardiac arrest patients into a process of organ donation. It is a medical, logistical and ethical challenge for the staff of the mobile emergency services. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. Thermochemical Considerations in Self-Sustaining Synthesis of Refractory Compounds,

    Science.gov (United States)

    1982-08-01

    REPORT DATE Defense Advanced Research Projects Agency August 1982 1400 Wilson Boulevard 13. NUMBER OF PAGES Arlington, Virginia 22209 14. MONITORING...TEMPERATURES FOR SOME REFRACTORY AND OTHER MATERIALS Material Temperature (*F) Hafnium carbide 7520 Tantalum carbide 7025 Graphite 6870 Zirconium carbide...4892 Zirconia 4850 Molybdenum 4748 Beryllia 4660 Zircon 4530 Boron carbide 4430 Silicon carbide (volatilizes) 4160 Spinel 3860 Alumina 3720 Magnesium

  6. A case of incomplete and refractory Kawasaki disease : diagnostic ...

    African Journals Online (AJOL)

    disease.[4,5] Not all cases ful l all the diagnostic criteria, and these are termed incomplete KD.[6,7] We report a case of incomplete KD that was refractory to the recommended standard treatment with intravenous immunoglobulin (IVIG), but responded to treatment with intravenous methylprednisolone. e case highlights the.

  7. Effectiveness of infliximab in refractory FDG PET-positive sarcoidosis

    NARCIS (Netherlands)

    Vorselaars, Adriane D M; Crommelin, Heleen A; Deneer, Vera H M; Meek, Bob; Claessen, Anke M E; Keijsers, Ruth G M; van Moorsel, Coline H M; Grutters, JC

    Inconclusive evidence for the efficacy of infliximab in sarcoidosis hinders the global use of this potentially beneficial drug. To study infliximab efficacy in a clinical setting, we performed a prospective open-label trial in patients refractory to conventional treatment. Patients (n=56) received

  8. Epidural blood patch for refractory low CSF pressure headache

    DEFF Research Database (Denmark)

    Madsen, Søren Aalbæk; Fomsgaard, Jonna Storm; Jensen, Rigmor

    2011-01-01

    reduction in frequency. An increase in days with use of medication was found. Increased awareness of low CSF pressure headache is emphasized and a controlled larger randomized study is needed to confirm the results. However the present results, allows us to conclude that EBP in treatment-refractory low CSF...

  9. Microscopic colitis: A review of etiology, treatment and refractory disease.

    Science.gov (United States)

    Park, Tina; Cave, David; Marshall, Christopher

    2015-08-07

    Microscopic colitis is a common cause of chronic, nonbloody diarrhea. Microscopic colitis is more common in women than men and usually affects patients in their sixth and seventh decade. This article reviews the etiology and medical management of microscopic colitis. The etiology of microscopic colitis is unknown, but it is associated with autoimmune disorders, such as celiac disease, polyarthritis, and thyroid disorders. Smoking has been identified as a risk factor of microscopic colitis. Exposure to medications, such as non-steroidal anti-inflammatory drugs, proton pump inhibitors, and selective serotonin reuptake inhibitors, is suspected to play a role in microscopic colitis, although their direct causal relationship has not been proven. Multiple medications, including corticosteroids, anti-diarrheals, cholestyramine, bismuth, 5-aminosalicylates, and immunomodulators, have been used to treat microscopic colitis with variable response rates. Budesonide is effective in inducing and maintaining clinical remission but relapse rate is as high as 82% when budesonide is discontinued. There is limited data on management of steroid-dependent microscopic colitis or refractory microscopic colitis. Immunomodulators seem to have low response rate 0%-56% for patients with refractory microscopic colitis. Response rate 66%-100% was observed for use of anti-tumor necrosis factor (TNF) therapy for refractory microscopic colitis. Anti-TNF and diverting ileostomy may be an option in severe or refractory microscopic colitis.

  10. Association of interleukin 17 / angiotensin II with refractory ...

    African Journals Online (AJOL)

    Abstract. Objective: The study was performed to investigate the association of interleukin 17 (IL 17) or angiotensin II (Ang II) with refractory hypertension risk in hemodialysis patients. Methods: Ninety hemodialysis patients were enrolled into this study, and those with hypertension were divided into two groups.

  11. Penetration and Effectiveness of Micronized Copper in Refractory Wood Species.

    Directory of Open Access Journals (Sweden)

    Chiara Civardi

    Full Text Available 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(OH2, 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(OH2 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.

  12. Issues Impacting Refractory Service Life in Biomass/Waste Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, J.P.; Kwong, K.-S.; Powell, C.A.

    2007-03-01

    Different carbon sources are used, or are being considered, as feedstock for gasifiers; including natural gas, coal, petroleum coke, and biomass. Biomass has been used with limited success because of issues such as ash impurity interactions with the refractory liner, which will be discussed in this paper.

  13. 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.

  14. Anaesthesia for left thoracoscopic sympathectomy for refractory long ...

    African Journals Online (AJOL)

    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 underwent successful left thoracoscopic sympathectomy. All three patients ...

  15. 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.

  16. Treatment-refractory, juvenile-onset bipolar affective disorder

    OpenAIRE

    Vijay Sagar, K. John

    2005-01-01

    A case of juvenile-onset bipolar affective disorder with a childhood history of attention-deficit hyperactivity disorder (ADHD) is presented. As the patient was refractory to treatment with mood stabilizers, clozapine was given, which succeeded in achieving remission. The disorder's natural history needs further study. Data also need to be collected for optimal pharmacotherapeutic guidance.

  17. Refractory generalised convulsive status epilepticus : a guide to treatment.

    Science.gov (United States)

    Kälviäinen, Reetta; Eriksson, Kai; Parviainen, Ilkka

    2005-01-01

    The patient with status epilepticus has continuous or rapidly repeating seizures. Generalised convulsive status epilepticus (GCSE) is the most common form of the disorder and is a life-threatening condition that requires prompt medical management. Status epilepticus that does not respond to first-line benzodiazepines (lorazepam or diazepam) or to second-line antiepileptic drugs (phenytoin/fosphenytoin, phenobarbital or valproate) is usually considered refractory and requires more aggressive treatment. The optimal treatment of refractory GCSE has not been defined, but patients should be treated in an intensive care unit, as artificial ventilation and haemodynamic support are required. Invasive haemodynamic monitoring is often necessary and EEG monitoring is essential. The drug treatment of refractory GCSE involves general anaesthesia with continuous intravenous anaesthetics given in doses that abolish all clinical and electrographic epileptic activity, often requiring sedation to the point of burst suppression on the EEG. Barbiturate anaesthetics, pentobarbital in the US and thiopental sodium in Europe and Australia, are the most frequently used agents and are highly effective for refractory GCSE both in children and adults. Indeed, they remain the only way to stop seizure activity with certainty in severely refractory cases. Other options are midazolam for adults and children and propofol for adults only.Regardless of the drug selected, intravenous fluids and vasopressors are usually required to treat hypotension. Once seizures have been controlled for 12-24 hours, continuous intravenous therapy should be gradually tapered off if the drug being administered is midazolam or propofol. Gradual tapering is probably not necessary with pentobarbital or thiopental sodium. Continuous EEG monitoring is required during high-dose treatment and while therapy is gradually withdrawn. During withdrawal of anaesthetic therapy, intravenous phenytoin/fosphenytoin or valproate should

  18. 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

    2018-02-01

    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.

  19. 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

  20. Modelling of Equilibrium Between Mantle and Core: Refractory, Volatile, and Highly Siderophile Elements

    Science.gov (United States)

    Righter, K.; Danielson, L.; Pando, K.; Shofner, G.; Lee, C. -T.

    2013-01-01

    Siderophile elements have been used to constrain conditions of core formation and differentiation for the Earth, Mars and other differentiated bodies [1]. Recent models for the Earth have concluded that the mantle and core did not fully equilibrate and the siderophile element contents of the mantle can only be explained under conditions where the oxygen fugacity changes from low to high during accretion and the mantle and core do not fully equilibrate [2,3]. However these conclusions go against several physical and chemical constraints. First, calculations suggest that even with the composition of accreting material changing from reduced to oxidized over time, the fO2 defined by metal-silicate equilibrium does not change substantially, only by approximately 1 logfO2 unit [4]. An increase of more than 2 logfO2 units in mantle oxidation are required in models of [2,3]. Secondly, calculations also show that metallic impacting material will become deformed and sheared during accretion to a large body, such that it becomes emulsified to a fine scale that allows equilibrium at nearly all conditions except for possibly the length scale for giant impacts [5] (contrary to conclusions of [6]). Using new data for D(Mo) metal/silicate at high pressures, together with updated partitioning expressions for many other elements, we will show that metal-silicate equilibrium across a long span of Earth s accretion history may explain the concentrations of many siderophile elements in Earth's mantle. The modeling includes refractory elements Ni, Co, Mo, and W, as well as highly siderophile elements Au, Pd and Pt, and volatile elements Cd, In, Bi, Sb, Ge and As.

  1. Extending Tabletop XUV Spectroscopy to the Liquid Phase to Examine Transition Metal Catalysts

    Science.gov (United States)

    Benke, Kristin; Ryland, Elizabeth S.; Vura-Weis, Josh

    2017-06-01

    M-edge spectroscopy of first row transition metals (3p to 3d excitation) is the low energy analogue of more well-known K- and L-edge spectroscopy, but can be implemented without the use of a synchrotron. Instead, M-edge spectroscopy can be performed as a tabletop method, relying on high harmonic generation (HHG) to produce ultrashort (˜ 20 fs) pulses of extreme ultraviolet (XUV) light in the range of 10-100s of eV. We have shown tabletop M-edge spectroscopy to be a valuable tool in determining the electronic structure of metal-centered coordination complexes and have demonstrated its capacity to yield element-specific information about a compound's oxidation state, spin state, and ligand field. The power of this technique to distinguish these features makes it a promising addition to the arsenal of methods used to study metal-centered catalysts. A catalytic reaction can be initiated photochemically and the XUV probe can be used to track oxidative and structural changes to identify the key intermediates. Until recently tabletop XUV spectroscopy has been performed on thin film samples, but in order to examine homogeneous catalysis, the technique must be adapted to look at samples in the liquid phase. The challenges of adapting tabletop XUV spectroscopy to the liquid phase lie in the lower attenuation length of XUV light compared to soft and hard x-rays and the lower flux compared to synchrotron methods. As a result, the sample must be limited to a sub-micron thickness as well as isolated from the vacuum environment required for x-ray spectroscopy. I am developing a liquid flow cell that relies on confining the sample between two x-ray transmissive SiN membranes, as has been demonstrated for use at synchrotrons, but adapted to the unique difficulties encountered in tabletop XUV spectroscopy.

  2. Iron refractory iron deficiency anemia: a heterogeneous disease that is not always iron refractory.

    Science.gov (United States)

    Donker, Albertine E; Schaap, Charlotte C M; Novotny, Vera M J; Smeets, Roel; Peters, Tessa M A; van den Heuvel, Bert L P; Raphael, Martine F; Rijneveld, Anita W; Appel, Inge M; Vlot, Andre J; Versluijs, A Birgitta; van Gelder, Michel; Granzen, Bernd; Janssen, Mirian C H; Rennings, Alexander J M; van de Veerdonk, Frank L; Brons, Paul P T; Bakkeren, Dirk L; Nijziel, Marten R; Vlasveld, L Thom; Swinkels, Dorine W

    2016-12-01

    TMPRSS6 variants that affect protein function result in impaired matriptase-2 function and consequently uninhibited hepcidin production, leading to iron refractory iron deficiency anemia (IRIDA). This disease is characterized by microcytic, hypochromic anemia and serum hepcidin values that are inappropriately high for body iron levels. Much is still unknown about its pathophysiology, genotype-phenotype correlation, and optimal clinical management. We describe 14 different TMPRSS6 variants, of which 9 are novel, in 21 phenotypically affected IRIDA patients from 20 families living in the Netherlands; 16 out of 21 patients were female. In 7 out of 21 cases DNA sequencing and multiplex ligation dependent probe amplification demonstrated only heterozygous TMPRSS6 variants. The age at presentation, disease severity, and response to iron supplementation were highly variable, even for patients and relatives with similar TMPRSS6 genotypes. Mono-allelic IRIDA patients had a milder phenotype with respect to hemoglobin and MCV and presented significantly later in life with anemia than bi-allelic patients. Transferrin saturation (TSAT)/hepcidin ratios were lower in IRIDA probands than in healthy relatives. Most patients required parenteral iron. Genotype alone was not predictive for the response to oral iron. We conclude that IRIDA is a genotypically and phenotypically heterogeneous disease. The high proportion of female patients and the discrepancy between phenotypes of probands and relatives with the same genotype, suggest a complex interplay between genetic and acquired factors in the pathogenesis of IRIDA. In the absence of inflammation, the TSAT/hepcidin ratio is a promising diagnostic tool, even after iron supplementation has been given. Am. J. Hematol. 91:E482-E490, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. Esophageal Stent for Refractory Variceal Bleeding: A Systemic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Xiao-Dong Shao

    2016-01-01

    Full Text Available Background. Preliminary studies suggest that covered self-expandable metal stents may be helpful in controlling esophageal variceal bleeding. Aims. To evaluate the effectiveness and safety of esophageal stent in refractory variceal bleeding in a systematic review and meta-analysis. Methods. A comprehensive literature search was conducted on PubMed, EMBASE, and Cochrane Library covering the period from January 1970 to December 2015. Data were selected and abstracted from eligible studies and were pooled using a random-effects model. Heterogeneity was assessed using I2 test. Results. Five studies involving 80 patients were included in the analysis. The age of patients ranged from 18 to 91 years. The mean duration of follow-up was 46.8 d (range, 30–60 d. The success rate of stent deployment was 96.7% (95% CI: 91.6%–99.5% and complete response to esophageal stenting was in 93.9% (95% CI: 82.2%–99.6%. The incidence of rebleeding was 13.2% (95% CI: 1.8%–32.8% and the overall mortality was 34.5% (95% CI: 24.8%–44.8%. Most of patients (87.4% died from hepatic or multiple organ failure, and only 12.6% of patients died from uncontrolled bleeding. There was no stent-related complication reported and the incidence of stent migration was 21.6% (95% CI: 4.7%–46.1%. Conclusion. Esophageal stent may be considered in patients with variceal bleeding refractory to conventional therapy.

  4. Combustion based technique for synthesis and joining of refractory materials

    Science.gov (United States)

    White, Jeremiah David Edward

    Gasless combustion systems offer features that make them attractive tools for a variety of potential applications. Among them are rapid heating rates, high exothermicity, and high maximum temperatures. These characteristics were exploited to accomplish three separate concepts including the joining of refractory materials, synthesis of a pore-free composite, and the study of thermal explosion in mechanically activated powders. Honeywell Aerospace is a leading producer of carbon brakes for commercial aircraft. The manufacturing process involves chemical vapor infiltration (CVI) to form a carbon matrix around a carbon fiber preform. A major disadvantage of this approach is the time required to form a fully dense preform, which is on the order of 140 days. In addition, after the brakes are in service, they have to be discarded while there is a relatively thick amount of friction material still available. There is a profit motive for reusing these discs which are out of spec. One such example would be to perform a refurbishment by bonding a new thin C/C element onto a used "core" to produce a brake that meets performance specifications. Unfortunately, joining C/C composites is not a simple task, as carbon does not lend itself to welding, and other means (e.g. mechanical or adhesives) would not hold up to the harsh operational conditions. A novel apparatus was designed, built, and proven to join C/C using so-called reactive resistance welding (RRW). It is shown that a joint stronger than the original material can be achieved using moderate electrical current and mechanical force. Additionally, joining layers of similar thickness and microstructure were obtained with different reactive media, ranging from pellets of pressed powders (˜1-2 mm) to thin metal foils (˜25 micron). By modifying the schematic of the RRW apparatus, porous C/C was infiltrated with liquid silicon in order to form a new pore-free C/C-SiC composite. It is shown that using such a process, the silicon

  5. Omeprazole for Refractory Gastroesophageal Reflux Disease during Pregnancy and Lactation

    Directory of Open Access Journals (Sweden)

    John K Marshall

    1998-01-01

    Full Text Available Symptomatic gastroesophageal reflux is a common complication of pregnancy and lactation. However, the safety of many effective medical therapies, including oral proton pump inhibitors, has not been well defined. The administration of oral omeprazole to a 41-year-old female during the third trimester of pregnancy, after ranitidine and cisapride failed to control her refractory gastroesophageal reflux, is reported. No adverse fetal effects were apparent, and the patient elected to continue omeprazole therapy (20 mg/day while breastfeeding. Peak omeprazole concentrations in breast milk (58 nM, 3 h after ingestion were less than 7% of the peak serum concentration (950 nM at 4 h, indicating minimal secretion. Although omeprazole is a potentially useful therapy for refractory gastroesophageal reflux during pregnancy and lactation, further data are needed to define better its safety and efficacy.

  6. Gamma radiography of refractory-lined vessels and components

    Energy Technology Data Exchange (ETDEWEB)

    Lapinski, N. P.

    1978-08-01

    Materials used in coal-conversion systems are exposed to high pressure, high temperature, corrosive and erosive gases, and liquids containing particulate matter. These severe environments necessitate an assessment of the integrity of components to prevent premature failures. Gamma radiography was evaluated as a viable technique for testing such components in the laboratory or after operation in situ. Penetrameters (image-quality indicators) were developed for refractory-lined vessels and transfer lines, and exposure times for various combinations of refractory-steel thicknesses were determined. Radiography with /sup 60/Co was performed on gasifier vessels, combustor vessels, and critical transfer lines in existing pilot plants using the experience gained through laboratory experiments. The results show that gamma radiography is a practical and effective method to detect critical conditions in coal-conversion system components. 18 figures, 3 tables.

  7. Treatment of pediatric refractory Crohn’s disease with thalidomide

    Science.gov (United States)

    Zheng, Cui-Fang; Xu, Jia-Hua; Huang, Ying; Leung, Ying-Kit

    2011-01-01

    AIM: To assess the efficacy and tolerability of thalidomide in pediatric Crohn’s disease (CD). METHODS: Six patients with refractory CD received thalidomide at an initial dose of 2 mg/kg per day for one month, then increased to 3 mg/kg per day or decreased to 1 mg/kg per day, and again further reduced to 0.5 mg/kg per day, according to the individual patient’s response to the drug. RESULTS: Remission was achieved within three months. Dramatic clinical improvement was demonstrated after thalidomide treatment. Endoscopic and pathological improvements were also observed after thalidomide treatment, which was well tolerated by all patients. CONCLUSION: Thalidomide is a useful drug for pediatric refractory CD. PMID:21455327

  8. Relationship between "extension of refractoriness" and probability of successful defibrillation.

    Science.gov (United States)

    Tovar, O H; Jones, J L

    1997-02-01

    The "extension of refractoriness" hypothesis, which suggests that the shock halts fibrillation by extending the refractory period, has not been directly tested. Defibrillation (5 isolated rabbit hearts; 111 episodes) was attempted by 8-ms pulses (65% tilt) delivered through epicardial patches. Monophasic action potentials were recorded in a low current density region (6.3 V/cm at 90% success). Fifty shocks failed to convert; 61 shocks successfully defibrillated. Postshock response duration (from shock to repolarization) was significantly longer for successful type A (with no postshock activations) defibrillation (102.3 +/- 7.5 ms) than for unsuccessful defibrillation (47.6 +/- 4.3 ms; P defibrillation were significantly longer than those for unsuccessful defibrillation. A minimum prolongation of 75 ms was associated with type A defibrillation. These results suggest that shock-induced response duration correlates with successful defibrillation and that a response of 75 ms is required to completely block fibrillation wavefronts.

  9. Etanercept in refractory lupus arthritis: An observational study.

    Science.gov (United States)

    Cortés-Hernández, Josefina; Egri, Natalia; Vilardell-Tarrés, Miquel; Ordi-Ros, Josep

    2015-06-01

    To investigate the long-term safety and preliminary efficacy of etanercept in patients with refractory lupus arthritis. We evaluated 43 patients in this observational cohort study. All received etanercept (50mg/week) in addition to concomitant immunosuppressive agents. Patient and disease characteristics were collected. Incidence of adverse events and the effect on autoantibody levels were evaluated. Clinical efficacy was measured by the 28-joint count and the SLEDAI-2K scores. Remission of lupus arthritis was defined by a 28-joint score = 0. Clinically inactive systemic disease was defined by a SLEDAI-2K score etanercept reduction. A total of 24 patients discontinued treatment, 12 of them due to clinical remission. Long-term therapy with etanercept was relatively safe and had remarkable long-term efficacy for refractory lupus arthritis. In view of these results, further controlled trials are warranted. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Effect of acute subendocardial ischemia on ventricular refractory periods.

    Science.gov (United States)

    Ma, Longle; Wang, Lexin

    2007-01-01

    To investigate the impact of acute subendocardial ischemia on the dispersion of ventricular refractory periods. Acute subendocardial ischemia was induced in sheep by partial ligation of the left circumflex coronary artery and rapid pacing of the left atrium. The ventricular effective refractory period (ERP) was measured in five areas of the left ventricle by a programmed premature stimulation technique. The average ERP and ERP dispersion remained unchanged in the control group (n=5, P>0.05). In the study group (n=5), the ERP was shortened following subendocardial ischemia. ERP dispersion decreased significantly from 48+/-9 ms to 36+/-13 ms 30 min after the ischemia (P=0.02). There was neither spontaneous nor stimulation-induced ventricular arrhythmia after ischemia. Acute subendocardial ischemia leads to a homogenous reduction of ventricular ERP. This may partially explain why subendocardial ischemia is associated with a low incidence of ventricular arrhythmia.

  11. Omeprazole for refractory gastroesophageal reflux disease during pregnancy and lactation.

    Science.gov (United States)

    Marshall, J K; Thompson, A B; Armstrong, D

    1998-04-01

    Symptomatic gastroesophageal reflux is a common complication of pregnancy and lactation. However, the safety of many effective medical therapies, including oral proton pump inhibitors, has not been well defined. The administration of oral omeprazole to a 41-year-old female during the third trimester of pregnancy, after ranitidine and cisapride failed to control her refractory gastroesophageal reflux, is reported. No adverse fetal effects were apparent, and the patient elected to continue omeprazole therapy (20 mg/day) while breastfeeding. Peak omeprazole concentrations in breast milk (58 nM, 3 h after ingestion) were less than 7% of the peak serum concentration (950 nM at 4 h), indicating minimal secretion. Although omeprazole is a potentially useful therapy for refractory gastroesophageal reflux during pregnancy and lactation, further data are needed to define better its safety and efficacy.

  12. Plasma exchange in cryptogenic new onset refractory status epilepticus.

    Science.gov (United States)

    Li, Judy; Saldivar, Christina; Maganti, Rama K

    2013-01-01

    New onset refractory status epilepticus (NORSE) is a recently described entity and has been difficult to treat because the etiology is often cryptogenic. Our aim in each case was to stop status epilepticus while simultaneously searching for the etiology. We describe three patients who presented with NORSE, who were refractory to multiple anticonvulsants and general anesthetics for at least 5 days. All patients had an extensive evaluation including MRI brain, CSF studies, radiologic scans for malignancy and serological autoimmune and infectious investigations. Each patient responded dramatically to the use of plasma exchange therapy with cessation of status epilepticus by the fourth day of treatment. Although an etiology was sought after, no appropriate cause for NORSE could be found. We propose early use of plasma exchange therapy (Class IV evidence) in hopes to prevent the complications of status epilepticus and prolonged hospitalization. Copyright © 2012 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  13. Combination of interferon and dexamethasone in refractory multiple myeloma.

    Science.gov (United States)

    San Miguel, J F; Moro, M; Bladé, J; Guerras, L; Hernandez, J; Jimenez-Galindo, R; Ortega, F; Gonzalez, M

    1990-01-01

    The present pilot study was designed to analyse the efficacy and toxicity of the association of interferon (IFN) and dexamethasone (Dx) in 32 resistant and relapsed myeloma patients. Among the evaluable cases, 15 (68 per cent) responded to treatment (32 per cent achieved an objective response--OR--and 36 per cent a partial response--PR--), the 'remission' status lasting for more than one year in six of them. Moreover, four out of the seven OR patients showed a reduction in B.M. plasma cells to less than 5 per cent. Five out of 11 patients that were previously refractory to VBAD, that includes high dose dexamethasone (Dx), responded to IFN-Dx. The protocol was generally well tolerated with only four patients discontinuing therapy due to adverse effects. The present results show that the combination IFN + Dx is a promising therapeutic approach for patients with refractory myeloma.

  14. Target therapies for radioiodine refractory advanced thyroid tumors.

    Science.gov (United States)

    Schlumberger, M

    2012-01-01

    A small but not irrelevant percentage of differentiated thyroid cancers become refractory to radioiodine treatment either because they lose the ability of taking up iodine over the time or because, despite a persistent uptaking ability, the effect of the radioiodine is lost in terms of tumor burden reduction. These patients receive only few and transient benefits from other conventional therapies and particularly from chemotherapy. In the last decade, several new drugs have been discovered as potentially useful and tested in clinical trials. They are mainly represented by protein kinase inhibitor molecules that should be proposed to advanced and progressive 131I refractory thyroid cancer patients by enrolling them in clinical trials or by the "off label" use of the drug.

  15. Brentuximab vedotin for relapsed or refractory Hodgkin’s lymphoma

    Directory of Open Access Journals (Sweden)

    Chen R

    2015-03-01

    Full Text Available Runzhe Chen, Baoan Chen Department of Hematology and Oncology (Key Department of Jiangsu Medicine, Zhongda Hospital, Medical School, Southeast University, Nanjing, Jiangsu Province, People’s Republic of China Abstract: Brentuximab vedotin is a promising antibody–drug conjugate (ADC targeting CD30 of tumor cells. It selectively delivers monomethyl auristatin E (MMAE into CD30-expressing cells and induces tumor cell apoptosis. Various clinical trials have provided evidence that it is effective in relapsed or refractory Hodgkin’s lymphoma (HL, and it has also shown its advantages in other CD30-positive lymphomas. In this review, we focus on the structure, mechanisms, and pharmacokinetics of brentuximab vedotin. We also summarize clinical trials with brentuximab vedotin and make recommendations for brentuximab vedotin in the treatment of relapsed or refractory HL. Keywords: lymphoma, CD30-positive, clinical trials, tumor cells, antitumor effects, monoclonal antibody

  16. Chronic, refractory CRPS involving 3 limbs: a case report.

    Science.gov (United States)

    Zyluk, A

    2013-06-01

    We report the case of a 26-year-old woman with CRPS involving consecutively 3 extremities during 8 years. None of the treatments used was effective and each CRPS episode resulted in persistence and chronification of the disease. We suggest that this patient presents a specific subtype of the disease, called "chronic, refractory CRPS" which is extremely severe, disabling and resistant to treatment. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Oral cyclosporine therapy for refractory severe vernal keratoconjunctivitis

    Directory of Open Access Journals (Sweden)

    Nikhil S Gokhale

    2012-01-01

    Full Text Available We report the success of oral cyclosporine therapy in a patient with severe vision-threatening vernal keratoconjunctivitis. A child presented with severe allergy which was not controlled with topical steroids, cyclosporine and mast cell stabilizers. Oral steroids were required repeatedly to suppress inflammation. Child showed a dramatic improvement and stabilization with oral cyclosporine therapy. Oral cyclosporine therapy can be tried in severe vision-threatening allergy refractory to conventional therapy.

  18. Treatment-refractory anxiety; definition, risk factors, and treatment challenges

    OpenAIRE

    Roy-Byrne, Peter

    2015-01-01

    A sizable proportion of psychiatric patients will seek clinical evaluation and treatment for anxiety symptoms reportedly refractory to treatment. This apparent lack of response is either due to ?pseudo-resistance? (a failure to have received and adhered to a recognized and effective treatment or treatments for their condition) or to true ?treatment resistance.? Pseudo-resistance can be due to clinician errors in selecting and delivering an appropriate treatment effectively, or to patient nona...

  19. Refractory plasmonics with titanium nitride: broadband metamaterial absorber.

    Science.gov (United States)

    Li, Wei; Guler, Urcan; Kinsey, Nathaniel; Naik, Gururaj V; Boltasseva, Alexandra; Guan, Jianguo; Shalaev, Vladimir M; Kildishev, Alexander V

    2014-12-17

    A high-temperature stable broadband plasmonic absorber is designed, fabricated, and optically characterized. A broadband absorber with an average high absorption of 95% and a total thickness of 240 nm is fabricated, using a refractory plasmonic material, titanium nitride. This absorber integrates both the plasmonic resonances and the dielectric-like loss. It opens a path for the interesting applications such as solar thermophotovoltaics and optical circuits. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Oral cyclosporine therapy for refractory severe vernal keratoconjunctivitis

    Science.gov (United States)

    Gokhale, Nikhil S; Samant, Rohini; Sharma, Vishnu

    2012-01-01

    We report the success of oral cyclosporine therapy in a patient with severe vision-threatening vernal keratoconjunctivitis. A child presented with severe allergy which was not controlled with topical steroids, cyclosporine and mast cell stabilizers. Oral steroids were required repeatedly to suppress inflammation. Child showed a dramatic improvement and stabilization with oral cyclosporine therapy. Oral cyclosporine therapy can be tried in severe vision-threatening allergy refractory to conventional therapy. PMID:22569387

  1. Low-Chrome/Chrome Free Refractories for Slagging Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    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 1275-1575º 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.

  2. Omeprazole for Refractory Gastroesophageal Reflux Disease during Pregnancy and Lactation

    OpenAIRE

    Marshall, John K; Thomson, Alan BR; Armstrong, David

    1998-01-01

    Symptomatic gastroesophageal reflux is a common complication of pregnancy and lactation. However, the safety of many effective medical therapies, including oral proton pump inhibitors, has not been well defined. The administration of oral omeprazole to a 41-year-old female during the third trimester of pregnancy, after ranitidine and cisapride failed to control her refractory gastroesophageal reflux, is reported. No adverse fetal effects were apparent, and the patient elected to continue omep...

  3. Plasmapheresis in a Patient With "Refractory" Urticarial Vasculitis

    OpenAIRE

    Kartal, Ozgur; Gulec, Mustafa; Caliskaner, Zafer; Nevruz, Oral; Cetin, Turker; Sener, Osman

    2012-01-01

    Immune complexes are found in the circulation of 30%-75% of patients with urticarial vasculitis and much evidence supports the role of these immune complexes in the pathogenesis of urticarial vasculitis. Plasmapheresis is effective for removing these immune complexes; however, there are few reports on the use of plasmapheresis in the treatment of urticarial vasculitis. We describe a case of "refractory" urticarial vasculitis in which the symptoms improved after plasmapheresis treatment. We su...

  4. ROSA DAMASCENA OIL: AN ADJUNCTIVE THERAPY FOR PEDIATRIC REFRACTORY SEIZURES

    OpenAIRE

    F. Ashrafzadeh MD; H. Rakhshandeh MD; E. Mahmodi MD

    2009-01-01

    ObjectiveSeveral investigations have demonstrated that Rosa damascena has an inhibitory effect on the hypothalamus and on pituitary system reactivity in the rat; it has also been shown that the essential oil of Rosa damascena has significant antiepileptic effects on pentylentetrazole (PTZ) induced seizures in rats. We aimed at assessing the effects of the essential oil of Rosa damascena when used as an adjunct treatment to treat children with refractory seizuresMaterials and MethodsIn this do...

  5. Influence of the phase composition of refractory materials on creep

    OpenAIRE

    Terzić A.; Pavlović Lj.; Milutinović-Nikolić A.

    2006-01-01

    In this paper, the relationship between the creeping effect and mineralogical characteristics of the applied binding phase for various refractory materials (high-alumina materials, with high or low impurity content, tar bonded either magnesite or dolomite materials and silicate bonded chrom-magnesite materials) is presented. The mechanism of creeping is analyzed and the activation energy for creep for each investigated material is obtained and discussed. All investigated materials are creep s...

  6. Postrepolarization refractoriness in acute ischemia and after antiarrhythmic drug administration: Action potential duration is not always an index of the refractory period

    NARCIS (Netherlands)

    Coronel, Ruben; Janse, Michiel J.; Opthof, Tobias; Wilde, Arthur A.; Taggart, Peter

    2012-01-01

    Action potential duration is widely used as a measure of refractory period in ischemia. Although the end of repolarization closely corresponds to the end of refractoriness in the well-perfused, well-oxygenated myocardium, it is no longer true for the ischemic myocardium, in which the recovery of

  7. Nonequilibrium dynamics of stochastic point processes with refractoriness.

    Science.gov (United States)

    Deger, Moritz; Helias, Moritz; Cardanobile, Stefano; Atay, Fatihcan M; Rotter, Stefan

    2010-08-01

    Stochastic point processes with refractoriness appear frequently in the quantitative analysis of physical and biological systems, such as the generation of action potentials by nerve cells, the release and reuptake of vesicles at a synapse, and the counting of particles by detector devices. Here we present an extension of renewal theory to describe ensembles of point processes with time varying input. This is made possible by a representation in terms of occupation numbers of two states: active and refractory. The dynamics of these occupation numbers follows a distributed delay differential equation. In particular, our theory enables us to uncover the effect of refractoriness on the time-dependent rate of an ensemble of encoding point processes in response to modulation of the input. We present exact solutions that demonstrate generic features, such as stochastic transients and oscillations in the step response as well as resonances, phase jumps and frequency doubling in the transfer of periodic signals. We show that a large class of renewal processes can indeed be regarded as special cases of the model we analyze. Hence our approach represents a widely applicable framework to define and analyze nonstationary renewal processes.

  8. 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

  9. 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

  10. 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.

  11. Super Refractory Status Epilepticus in Hashimoto’s Encephalopathy

    Directory of Open Access Journals (Sweden)

    Mujahid Al-Busaidi

    2017-05-01

    Full Text Available We present a case of a 38-year-old woman who was at eight weeks of gestation and was admitted to Sultan Qaboos University Hospital with refractory status epilepticus (SE. She presented with a two-day history of fever and a depressed level of consciousness that was followed with generalized tonic-clonic seizures. She progressed to refractory SE that required intubation and mechanical ventilation. Autoimmune workup was suggestive of Hashimoto’s encephalopathy (HE as suggested by the high levels of thyroid antibodies. Her magnetic resonance imaging showed bilateral hippocampal and basal ganglia hyperintensities, and electroencephalogram showed bilateral frontal epileptiform discharges. Other autoimmune workup was negative. Intravenous anesthetics were started including propofol, midazolam, ketamine, and thiopentone. She was started on multiple immunosuppressive therapies. Multiple antiepileptics were used including phenytoin, lamotrigine, levetiracetam, sodium valproate, clobazam, phenobarbital, and lacosamide. The outcome was unusual in terms of refractoriness to immunotherapy treatment despite a confirmed diagnosis. We did a literature review of all cases with HE presenting with SE with their clinical characteristics and outcome.

  12. Obinutuzumab for relapsed or refractory indolent non-Hodgkin's lymphomas.

    Science.gov (United States)

    Gabellier, Ludovic; Cartron, Guillaume

    2016-04-01

    The use of anti-CD20 monoclonal antibodies (mAbs), such as rituximab, in CD20-positive B-cell malignancies has dramatically improved the outcome of chronic lymphoid leukemia and non-Hodgkin's lymphomas (NHL). However, the occurrence of relapse and development of rituximab-refractory disease highlight the need to develop novel anti-CD20 mAbs, with improved mechanisms of action. Obinutuzumab is the first humanized type II glycoengineered anti-CD20 mAb. In vitro and in vivo data suggested several differences compared with rituximab, including a low level of complement-dependent cytotoxicity and an increased direct nonapoptotic cell death. Moreover, the glycoengineered Fc-linked nonfucosylated oligosaccharide enhanced the Fc-Fcγ receptor (FcγR) IIIa interaction, resulting in improved antibody-dependent cellular cytotoxicity and phagocytosis. Preclinical models suggested that these differences translate into superior survival in murine lymphoma models. Phase I/II trials in monotherapy in relapsed or refractory B-cell NHL demonstrated that obinutuzumab has an acceptable safety profile, infusion-related reactions being the most common adverse event. In rituximab-refractory indolent NHL, the recent randomized phase III GADOLIN study demonstrated an improved median progression-free survival for patients treated with obinutuzumab plus bendamustine rather than bendamustine alone. Further trials are ongoing to determine the role of obinutuzumab as a first-line agent in the treatment of follicular lymphoma.

  13. Refractory gastric antral vascular ectasia: a new endoscopic approach.

    Science.gov (United States)

    Zulli, C; Del Prete, A; Romano, M; Esposito, F; Amato, M R; Esposito, P

    2015-11-01

    Gastric antral vascular ectasia (GAVE) is an uncommon disorder observed in patients with liver cirrhosis, causing upper gastro-intestinal haemorrhage. GAVE is diagnosed through esophagogastroduodenoscopy and is characterized by the presence of visible columns of red tortuous enlarged vessels along the longitudinal folds of the antrum (i.e., so-called watermelon stomach). Pharmacological, endoscopic and surgical approaches have been proposed for the treatment of GAVE. Endoscopy represents the gold standard for GAVE treatment. The most widely used endoscopic approach is represented by Neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. Argon plasma coagulation (APC) has been proven to be more efficient in terms of costs and complication rates than and equally effective as Nd:YAG. Other endoscopic procedures proposed for this treatment are banding ligature (EBL) and sclerotherapy with Polidocanol. Refractory GAVE represents a therapeutic challenge because it may cause persistent anemia, often leading to repeated blood transfusions due to the inefficacy of pharmacological and endoscopic therapeutic approaches. Endoscopic band ligation (EBL) has been shown to be superior to APC in the treatment of refractory GAVE. Surgical antrectomy by Billroth I anastomosis can be considered in selected cases. In this study, we report a successful endoscopic treatment of refractory GAVE by using a combination of submucosal injection of 1% Polidocanol at the four antral quadrants and subsequent application of APC on the visible antral lesions in two patients.

  14. 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.

  15. Efficacy and tolerability of levetiracetam for pediatric refractory epilepsy.

    Science.gov (United States)

    Muramatsu, Kazuhiro; Sawaura, Noriko; Ogata, Tomomi; Makioka, Nishiki; Tomita, Keiko; Motojima, Toshino; Ida, Kuniko; Hazama, Kyoko; Arakawa, Hirokazu

    2017-03-01

    Levetiracetam has a high tolerability and is effective against various seizure types and epilepsy syndromes. However, no study has specifically evaluated the efficacy of levetiracetam in children with refractory epilepsy based on magnetic resonance imaging (MRI) findings and the presence of intellectual disability (ID). We retrospectively evaluated levetiracetam efficacy and safety in 49 pediatric patients who met the following inclusion criteria: (1) diagnosis of refractory epilepsy with first-line antiepileptic (AED) treatment ⩾2years, (2) younger than 20years old, and (3) received oral levetiracetam treatment for ⩾6months. We assessed the relationships of these outcomes with MRI findings and ID status. Eighteen (37%) patients achieved a ⩾50% reduction in seizure frequency, and the majority (78%) had no remarkable side effects. Twenty-two (45%) patients had previously been treated with more than seven antiepileptic drugs prior to levetiracetam. Among 18 patients who achieved a ⩾50% reduction in seizure frequency, 13 and 5 had negative and positive MRI findings, and 9 and 9 had and did not have ID, respectively. Our findings suggest that even for intractable pediatric cases with symptomatic etiology (i.e., MRI lesion and ID), levetiracetam has favorable efficacy for refractory epilepsy with tolerable adverse effects. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  16. Role of rectal myomectomy in refractory chronic constipation

    Directory of Open Access Journals (Sweden)

    Rajeev G Redkar

    2012-01-01

    Full Text Available Background: To assess the role of diagnostic and therapeutic value of anorectal myectomy in cases of chronic refractory constipation. Materials and Methods: Twenty-eight patients 11 months to 9 years of age presenting with chronic constipation, with contrast enema showing dilated rectum and sigmoid colon were included in the study. Anorectal myectomy under general anaesthesia was carried out in these selected patients and were followed-up for up to 6 months to 5 years. Clinical improvement was measured by post-operative bowel habits and relief of symptoms. Results: Twenty-two patients improved clinically; partial response in 4 patients, no response in 2 patients. Two patient required further pull through surgery and was found to have transition zone at the recto-sigmoid level. Ten patients had aganglionosis (of which 5 had ganglion cells present in the proximal part of speciment, 7 had normal histology, 7 had hypoganglionosis, 2 had intestinal neuronal dysplasia, one had nerve hypertrophy and one had immature ganglia. Conclusion: Anorectal myectomy is an effective and technically simple procedure in selected patients with chronic refractory constipation, for both diagnostic and therapeutic purpose. Because apart from confirming Hirschsprung′s disease, it also therapeutically relieves symptoms in 93% of patients with chronic refractory constipation.

  17. Posterior quadrant disconnection for refractory epilepsy: A case series

    Directory of Open Access Journals (Sweden)

    Javeria Nooraine

    2014-01-01

    Full Text Available Objective: To analyze the surgical outcome and safety of posterior quadrant disconnection in medically refractory epilepsy arising from the posterior head region from a level IV tertiary care center over a period of three years. Materials and Methods: Seven consecutive patients who underwent posterior quadrant disconnection for refractory epilepsy were analyzed. Results: We analyzed the data of seven (n = 7 consecutive posterior quadrant epilepsy patients who underwent posterior quadrant disconnection with a mean age of 8.5 years over the last three years of which 4 were male and 3 females. All patients underwent extensive pre-surgical evaluation including detailed history, examination, prolonged video EEG recordings, neuropsychological testing, MRI brain, DTI, PET scan (n = 6, fMRI (n = 4, WADA test (n = 1 and invasive recording (n = 1, Of seven patients four had left sided pathology and three had right sided pathology. All patients except one underwent pure disconnection and one underwent partial resection. Conclusion: Posterior quadrant disconnection is effective surgical procedure for medically refractory epilepsy arising from the posterior quadrant in carefully selected patients without morbidity or functional disability across various age groups especially in children. In our series, all seven patient had good seizure outcome and none had functional disabilities.

  18. Interaction mechanism between refractory and melts in iron bath smelting reduction process

    Directory of Open Access Journals (Sweden)

    Qiu G.B.

    2010-01-01

    Full Text Available The corrosion behavior of three sorts of refractories based on alumina-graphite were studied by immersion tests. The melts included smelting reduction molten slag and corresponding carbon saturated molten iron. The influence of test temperature, FeO content in slag and specimen rotative velocity on the corrosion rate of refractories was examined. By means of SEM and EDS, the microstructure change of the refractories after immersion test in kinds of melts was studied. The morphology of the deteriorated layer showed the corrosion extent of refractories. With the addition of zirconia and titania into the refractories, the corrosion rate changed to some extent. The corrosion rate of three sorts of refractories increased dramatically with the increasing FeO content in smelting reduction slag. Compared with alumina-graphite refractory and alumina-graphite-zirconia refractory, alumina-graphite-titania refractory had stronger corrosion resistance in the smelting reduction conditions. By the results of SEM and EDS, the corrosion mechanism of refractories was developed.

  19. Molecular dynamics analysis of oxidation, segregation and stress corrosion failures of refractory alloys

    Science.gov (United States)

    Verners, Osvalds

    The focuses of the thesis are heating induced segregation/mixing of refractory alloys, along with oxidation and stress corrosion properties of selected fcc metals and thin oxide layers formed on the surfaces thereof. The particular studies include segregation and oxidation simulation of Mo3Ni alloy clusters. These reveal favorable stabilizing oxidation resistance properties due to the Ni component, which diffuses during annealing to the surface of the clusters. A comparative study has been done for different sized Al grains in Fe or Ni bulk matrices. Its results indicate that Ni matrix is favorable due to the grain dissolution and energetic stability properties upon heating and cooling of the structures. Oxidation simulation of the same structures in slab structures indicate that unmixed metals oxidize first and the alloy layer, which forms only for the Ni matrix, eventually segregates to single-metal layers, which oxidize subsequently. The stress corrosion properties of Al oxide slab/thin film structures in water, noble gas and vacuum environments have been studied with the aim of subsequent stress corrosion simulation of alloys or metals with protective surface oxide layers. The obtained results indicate brittle type failures, which involve shear deformation and localized amorphization. The plasticity enhancing fluid environment effects are found to be similar for both reactive and nonreactive species, which indicates significant pressure effects and passivated reactivity of surfaces. Parallel to the corrosion study, strain rate effects and cyclic loading behavior for slab structures in vacuum have been characterized and compared at different temperatures. These indicate time dependent deformation mechanisms including temperature enhanced local amorphization prior to crack formation. Complementary analyses include extended timescale crack behavior of a slab structure in vacuum using parallel replica dynamics and steady state analysis of a slab structure in water

  20. Features of Adult Autoimmune Enteropathy Compared With Refractory Celiac Disease.

    Science.gov (United States)

    Sharma, Ayush; Choung, Rok Seon; Wang, Xiao Jing; Russo, Pierre A; Wu, Tsung-Teh; Nehra, Vandana; Murray, Joseph A

    2018-01-04

    Little is known about the features of immune-mediated non-celiac villous atrophies, such as autoimmune enteropathy (AIE). We investigated the demographic, clinical, and histologic features of adults with AIE compared to adults with refractory celiac disease type 1. We also report outcomes of treatment with open-label budesonide. We performed a retrospective case-control of patients with AIE (n=30) seen at the Mayo Clinic (in Rochester, Minnesota) from 2000 through 2015. Patients with refractory celiac disease type 1 who were treated with open-label budesonide served as controls (n=42). Biopsy specimens were reviewed for all patients. We collected demographic, clinical, biochemical and histologic data from patients. We also collected data on responses to open-capsule budesonide from patients with AIE (available from 22 patients) and controls (available from 42 patients); the median duration of follow up was 28 months (range, 0-1421 months). Patients with AIE had a higher proportion of men (60%) and were younger (mean, 44±18 years) than patients with refractory celiac disease type 1 (29% men; P=.002 and mean age, 57±16 years; P=.007). A higher proportion of patients with AIE presented with chronic diarrhea (100%) and weight loss (90%) than patients with refractory celiac disease type 1 (71%; P40 per 100 epithelial cells in 100%) compared with patients with AIE (in 50%) (P=.003). Conventional therapy (systemic steroids) had failed in most patients with AIE (a complete clinical response was reported in only 7 patients) before treatment with open-capsule budesonide was initiated. A clinical response to open-capsule budesonide was reported for 85% of patients with AIE (50% complete response, 35% partial response) compared to 92% of controls (68% complete response, 24% partial response). In a retrospective study of 30 patients with AIE, followed for a median 28 months, we found this disease to have has distinct demographic, clinical, and histologic characteristics

  1. 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

  2. Characterization and analysis of sub-micron surface roughness of injection moulded microfluidic systems using White Light Interferometry

    DEFF Research Database (Denmark)

    Tosello, Guido; Marinello, Francesco; Hansen, Hans Nørgaard

    2009-01-01

    Surface topography is of great importance in polymer micro fluidics, therefore the replication capability of the process and the surface quality of the tool has to be suitably optimized. In this paper, optical profilometry (white light interferometry, WLI) is implemented for topographical...

  3. Characterization and analysis of micro channels and sub-micron surface roughness of injection moulded microfluidic systems using optical metrology

    DEFF Research Database (Denmark)

    Tosello, Guido; Marinello, Francesco; Hansen, Hans Nørgaard

    2012-01-01

    Precision injection moulding of miniaturized products with micro features such as channels for microfluidic applications poses the greatest challenges in terms of tooling technology and process optimization. The injection moulding process window of polypropylene was validated using a metrological...... approach for the production of a microfluidic substrate. Dimensional accuracy of micro channels 48 µm wide and 110 µm deep, as well as quality surface topography replication (surface roughness from 30 nm to 360 nm) were investigated using non-contact measuring instruments such as an optical coordinate...... measuring machine and a white light interferometer respectively. The effect of the dimensional scale range on the micro/nano features replication was evaluated and it was found to be the dominant parameter if compared with the effect of the other process-related parameters investigated (melt and mould...

  4. Characterization and analysis of micro channels and sub-micron surface roughness of injection moulded microfluidic systems using optical metrology

    DEFF Research Database (Denmark)

    Tosello, Guido; Marinello, Francesco; Hansen, Hans Nørgaard

    2009-01-01

    Precision injection moulding of miniaturized products with micro features such as channels for microfluidic applications poses the greatest challenges in terms of tooling technology and process optimization. The injection moulding process window of polypropylene was validated using a metrological...... approach for the production of a microfluidic substrate. Dimensional accuracy of micro channels 48 µm wide and 110 µm deep, as well as quality surface topography replication (surface roughness from 30 nm to 360 nm) were investigated using non-contact measuring instruments such as an optical coordinate...... measuring machine and a white light interferometer respectively. The effect of the dimensional scale range on the micro/nano features replication was evaluated and it was found to be the dominant parameter if compared with the effect of the other process-related parameters investigated (melt and mould...

  5. Characterization of the critical current and physical properties of superconducting epitaxial NbTiN sub-micron structures

    Energy Technology Data Exchange (ETDEWEB)

    Klimov, A., E-mail: aklimov@ite.waw.pl [Institute of Electron Technology, Al. Lotników 32/46, 02-668 Warsaw (Poland); Słysz, W.; Guziewicz, M. [Institute of Electron Technology, Al. Lotników 32/46, 02-668 Warsaw (Poland); Kolkovsky, V.; Zaytseva, I.; Malinowski, A. [Institute of Physics Polish Academy of Science, Al. Lotników 32/46, 02-668 Warsaw (Poland)

    2017-05-15

    Highlights: • This manuscript presents investigation of the critical current dependence of Nb(Ti)N nanostructured superconducting single photon detectors (SNSPD) in function of temperature and applied magnetic field. • Presented results are complimentary and compared with the same data received for submicron-wide single bridge Nb(Ti)N structures. • Our data demonstrate significant influence of local constrictions on physical properties of our SNSPD detectors. - Abstract: Measurements of critical current in NbTiN as a function of applied magnetic field and temperature are reported for two samples: 700-nm-wide bridge and 100-nm-wide meander. In 700-nm-wide NbTiN bridge we pinpointed the limiting factors for the critical current density to be current-driven vortex de-pinning at low temperatures and thermally activated flux flow closer to the transition temperature. In 100-nm-wide NbTiN meander we found phase slips activation, accompanied by hotspots formation at all measured temperatures. These two types of structures demonstrate different dependence of the critical current on the applied magnetic field. Although our NbTiN meander structures has high de-pairing critical current densities ∼10{sup 7} A/cm{sup 2} at low temperatures, the real critical currents are smaller due to the presence of the local constrictions.

  6. Comparative Mineralogy, Microstructure and Compositional Trends in the Sub-Micron Size Fractions of Mare and Highland Lunar Soils

    Science.gov (United States)

    Thompson, M. S.; Christoffersen, R.; Noble, S. K.; Keller, L. P.

    2012-01-01

    The morphology, mineralogy, chemical composition and optical properties of lunar soils show distinct correlations as a function of grain size and origin [1,2,3]. In the mineralogy type, microstructure and major element compositions of grains in this important size range in lunar soils.

  7. High performance imaging of relativistic soft X-ray harmonics by sub-micron resolution LiF film detectors

    Energy Technology Data Exchange (ETDEWEB)

    Pikuz, Tatiana; Faenov, Anatoly [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Pirozhkov, Alexander; Esirkepov, Timur; Koga, James; Nakamura, Tatsufumi; Bulanov, Sergei; Fukuda, Yuji; Hayashi, Yukio; Kotaki, Hideyuki; Kando, Masaki [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Astapov, Artem; Pikuz, Sergey Jr. [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Klushin, Georgy [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); International Laser Center of M.V. Lomonosov Moscow State University, Moscow (Russian Federation); Nagorskiy, Nikolai; Magnitskiy, Sergei [International Laser Center of M.V. Lomonosov Moscow State University, Moscow (Russian Federation); Kato, Yoshiaki [The Graduate School for the Creation of New Photonics Industries, Hamamatsu, Shizuoka (Japan)

    2012-12-15

    The spectrum variation and the coherent properties of the high-order harmonics (HOH) generated by an oscillating electron spikes formed at the joint of the boundaries of a cavity and a bow wave, which are created by a relativistically self-focusing laser in underdense gas jet plasma, are investigated. This new mechanism for HOH generation efficiently produces emission from ultraviolet up to the XUV ''water window'' spectral range. To characterize such source in the wide spectral range a diffraction imaging technique is applied. High spatial resolution EUV and soft X-ray LiF film detector have been used for precise measurements of diffraction patterns. The measurements under observation angle of 8 to the axis of laser beam propagation have been performed. The diffraction patterns were observed on the detector clearly, when the square mesh was placed at the distance of 500 mm from the output of plasma and at the distance of 27.2 mm in front of the detector. It is shown that observed experimental patterns are well consistent with modeled ones for theoretical HOH spectrum, provided by particle-in-cell simulations of a relativistic-irradiance laser pulse interaction with underdense plasma (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. A Nordic project on high speed low power design in sub-micron CMOS technology for mobile phones

    DEFF Research Database (Denmark)

    Olesen, Ole

    circuit design is based on state-of-the-art CMOS technology (0.5µm and below) including circuits operating at 2GHz. CMOS technology is chosen, since a CMOS implementation is likely to be significantly cheaper than a bipolar or a BiCMOS solution, and it offers the possibility to integrate the predominantly...

  9. Sub-micron particle behaviour and capture at an immuno-sensor surface in an ultrasonic standing wave.

    Science.gov (United States)

    Kuznetsova, Larisa A; Martin, Stacey P; Coakley, W Terence

    2005-12-15

    The capture of 200 nm biotinylated latex beads from suspensions of concentration 10(7) to 2.5 x 10(8) particle/ml on an immuno-coated surface of the acoustic reflector in an ultrasound standing wave (USW) resonator has been studied while the acoustic pathlength was less than one half wavelength (lambda/2). The particles were delivered to the reflector's surface by acoustically induced flow. The capture dependencies on suspension concentration, duration of experiments and acoustic pressure have been established at 1.09, 1.46 and 1.75 MHz. Five-fold capture increase has been obtained at 1.75 MHz in comparison to the control (no ultrasound) situation. The contrasting behaviours of 1, 0.5 and 0.2 mum fluorescent latex beads in a lambda/4 USW resonator at 1.46 MHz have been characterized. The particle movements were observed with an epi-fluorescent microscope and the velocities of the particles were measured by particle image velocimetry (PIV). The experiments showed that whereas the trajectories of 1 mum particles were mainly affected by the direct radiation force, 0.5 mum particles were influenced both by the radiation force and acoustic streaming. The 0.2 mum latex beads followed acoustic streaming in the chamber and were not detectably affected by the radiation force. The streaming-associated behaviour of the 200 nm particles has implications for enhanced immunocapture of viruses and macromolecules (both of which are also too small to experience significant acoustic radiation force).

  10. Imaging of vaporised sub-micron phase change contrast agents with high frame rate ultrasound and optics.

    Science.gov (United States)

    Lin, Shengtao; Zhang, Ge; Jamburidze, Akaki; Chee, Melisse; Leow, Chee Hau; Garbin, Valeria; Tang, Meng-Xing

    2018-01-31

    Phase-change ultrasound contrast agent (PCCA), or nanodroplet shows promises as an alternative to conventional microbubble agent over a wide range of diagnostic applications. In the meantime, high-frame-rate (HFR) ultrasound imaging with microbubbles enables unprecedentedly temporal resolution compared to traditional contrast-enhanced ultrasound imaging. The combination of HFR ultrasound imaging and PCCAs can offer opportunities to observe and better understand PCCA behaviour after vaporisation capturing the fast phenomenon at a high temporal resolution. In this study, we utilised HFR ultrasound at frame rates in the kilohertz range (5-20 kHz) to image the native and size-selected PCCA populations immediately after vaporisation in vitro with clinical acoustic parameters. The size-selected PCCAs through filtration are shown to preserve submicron-sized (mean diameter < 200 nm) population without micron-sized outliers (> 1 µm) that are originally from the native PCCA emulsion. The results demonstrate imaging signals with different amplitude and temporal features compared to that of microbubbles. Compared with microbubbles, both B-mode and Pulse-Inversion (PI) signals from vaporised PCCA populations were reduced significantly in the first tens of milliseconds, while only B-mode signals from the PCCAs recovered during the next 400 ms, suggesting significant changes to the size distribution of PCCAs after vaporisation. It is also shown that such recovery in signal over time is not evident when using size-selective PCCAs. Furthermore, it was found that signals from the vaporised PCCA populations are affected by the amplitude and frame rate of the HFR ultrasound imaging. Using high-speed optical camera observation (30 kHz), we observed the particle size change in the vaporised PCCA populations exposed to the HFR ultrasound imaging pulses. These findings can benefit the understandings of PCCA behaviour under HFR ultrasound imaging. © 2018 Institute of Physics and Engineering in Medicine.

  11. Influence of biomass burning on mixing state of sub-micron aerosol particles in the North China Plain

    Science.gov (United States)

    Kecorius, Simonas; Ma, Nan; Teich, Monique; van Pinxteren, Dominik; Zhang, Shenglan; Gröβ, Johannes; Spindler, Gerald; Müller, Konrad; Iinuma, Yoshiteru; Hu, Min; Herrmann, Hartmut; Wiedensohler, Alfred

    2017-09-01

    Particulate emissions from crop residue burning decrease the air quality as well as influence aerosol radiative properties on a regional scale. The North China Plain (NCP) is known for the large scale biomass burning (BB) of field residues, which often results in heavy haze pollution episodes across the region. We have been able to capture a unique BB episode during the international CAREBeijing-NCP intensive field campaign in Wangdu in the NCP (38.6°N, 115.2°E) from June to July 2014. It was found that aerosol particles originating from this BB event showed a significantly different mixing state compared with clean and non-BB pollution episodes. BB originated particles showed a narrower probability density function (PDF) of shrink factor (SF). And the maximum was found at shrink factor of 0.6, which is higher than in other episodes. The non-volatile particle number fraction during the BB episode decreased to 3% and was the lowest measured value compared to all other predefined episodes. To evaluate the influence of particle mixing state on aerosol single scattering albedo (SSA), SSA at different RHs was simulated using the measured aerosol physical-chemical properties. The differences between the calculated SSA for biomass burning, clean and pollution episodes are significant, meaning that the variation of SSA in different pollution conditions needs to be considered in the evaluation of aerosol direct radiative effects in the NCP. And the calculated SSA was found to be quite sensitive on the mixing state of BC, especially at low-RH condition. The simulated SSA was also compared with the measured values. For all the three predefined episodes, the measured SSA are very close to the calculated ones with assumed mixing states of homogeneously internal and core-shell internal mixing, indicating that both of the conception models are appropriate for the calculation of ambient SSA in the NCP.

  12. Perampanel in patients with refractory and super-refractory status epilepticus in a neurological intensive care unit.

    Science.gov (United States)

    Rohracher, A; Höfler, J; Kalss, G; Leitinger, M; Kuchukhidze, G; Deak, I; Dobesberger, J; Novak, H; Pilz, G; Zerbs, A; Trinka, E

    2015-08-01

    In refractory status epilepticus (SE), because of subcellular maladaptive changes, GABAergic drugs are no longer effective, and the excitatory neurotransmitter glutamate (Glu) plays a major role in seizure perpetuation. Perampanel (PER, licensed since 09/2012) is the first orally active noncompetitive AMPA receptor antagonist for adjunctive treatment of refractory focal epilepsy. We analyzed treatment response, seizure outcome, and adverse effects of add-on treatment with perampanel in patients with refractory status epilepticus in the Neurological Intensive Care Unit (NICU), Salzburg, Austria between 09/2012 and 11/2014 by retrospective chart review. Twelve patients (75% women) with refractory status epilepticus were treated with PER administered per nasogastric tube between 09/2012 and 11/2014. Median age was 75 years [range: 60-91]. The most frequent SE type was nonconvulsive SE (NCSE) with (5/12, 42%) and without coma (6/12, 50%). In seven patients (58%), SE arose de novo, with an acute symptomatic cause in five patients (42%). Cerebrovascular diseases (4/12, 33%) and cerebral tumors (4/12, 33%) were the most common etiologies. Perampanel was given after a median number of four antiepileptic drugs [range: 2-7] and a median time of 1.5 days [range: 0.8-18.3]. In one patient (8%), clinical improvement was observed within 24h and EEG improvement within 60 h after administration of PER, while in another patient (8%), clinical and EEG improvement was observed more than 48 h after administration. Median initial dose was 4 mg [range: 2-12; SD: 4.11], titrated up to a median of 12 mg [range: 4-12] in steps of 2 to 4 mg per day. No adverse effects were reported regarding cardiorespiratory changes or laboratory parameters. Outcomes after SE were moderate disability in five patients (42%), death in three patients (25%), and persistent vegetative state in two patients (17%). Though glutamate plays a major role in seizure perpetuation, the noncompetitive AMPA receptor

  13. 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.

  14. RESULTS OF OUTPATIENT PROGRAM ON EFFECTIVE THERAPY OF REFRACTORY ARTERIAL HYPERTENSION

    OpenAIRE

    M. M. Batyushin; I. V. Derevyankina; M. Z. Gasanov; O. V. Akopova; K. I. Babiyan; Y. N. Boychenko; N. V. Vasilchenko; T. A. Gabysyan; S. Ch. Gayboryan; I. S. Golovatenko; N. M. Demkova; D. O. Dmitriev; E. V. Kirtava; O. L. Kotyankova; G. V. Ludanova

    2015-01-01

    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 antag...

  15. RESULTS OF OUTPATIENT PROGRAM ON EFFECTIVE THERAPY OF REFRACTORY ARTERIAL HYPERTENSION

    OpenAIRE

    M. M. Batyushin; I. V. Derevyankina; M. Z. Gasanov; O. V. Akopova; K. I. Babiyan; Y. N. Boychenko; N. V. Vasilchenko; T. A. Gabysyan; S. Ch. Gayboryan; I. S. Golovatenko; N. M. Demkova; D. O. Dmitriev; E. V. Kirtava; O. L. Kotyankova; G. V. Ludanova

    2007-01-01

    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 antag...

  16. Vagal nerve stimulation for medically refractory epilepsy in Angelman syndrome: a series of three cases.

    Science.gov (United States)

    Tomei, Krystal L; Mau, Christine Y; Ghali, Michael; Pak, Jayoung; Goldstein, Ira M

    2018-03-01

    We describe three children with Angelman syndrome and medically refractory epilepsy. Case series of three pediatric patients with Angelman syndrome and medically refractory epilepsy. All three patients failed medical treatment and were recommended for vagal nerve stimulator (VNS) implantation. Following VNS implantation, all three patients experienced reduction in seizure frequency greater than that afforded by medication alone. We present vagal nerve stimulator implantation as a viable treatment option for medically refractory epilepsy associated with Angelman syndrome.

  17. Method of making metal matrix composites reinforced with ceramic particulates

    Science.gov (United States)

    Cornie, James A.; Kattamis, Theodoulos; Chambers, Brent V.; Bond, Bruce E.; Varela, Raul H.

    1989-01-01

    Composite materials and methods for making such materials are disclosed in which dispersed ceramic particles are at chemical equilibrium with a base metal matrix, thereby permitting such materials to be remelted and subsequently cast or otherwise processed to form net weight parts and other finished (or semi-finished) articles while maintaining the microstructure and mechanical properties (e.g. wear resistance or hardness) of the original composite. The composite materials of the present invention are composed of ceramic particles in a base metal matrix. The ceramics are preferably carbides of titanium, zirconium, tungsten, molybdenum or other refractory metals. The base metal can be iron, nickel, cobalt, chromium or other high temperature metal and alloys thereof. For ferrous matrices, alloys suitable for use as the base metal include cast iron, carbon steels, stainless steels and iron-based superalloys.

  18. Method of making metal matrix composites reinforced with ceramic particulates

    Science.gov (United States)

    Cornie, J.A.; Kattamis, T.; Chambers, B.V.; Bond, B.E.; Varela, R.H.

    1989-08-01

    Composite materials and methods for making such materials are disclosed in which dispersed ceramic particles are at chemical equilibrium with a base metal matrix, thereby permitting such materials to be remelted and subsequently cast or otherwise processed to form net weight parts and other finished (or semi-finished) articles while maintaining the microstructure and mechanical properties (e.g. wear resistance or hardness) of the original composite. The composite materials of the present invention are composed of ceramic particles in a base metal matrix. The ceramics are preferably carbides of titanium, zirconium, tungsten, molybdenum or other refractory metals. The base metal can be iron, nickel, cobalt, chromium or other high temperature metal and alloys thereof. For ferrous matrices, alloys suitable for use as the base metal include cast iron, carbon steels, stainless steels and iron-based superalloys. 2 figs.

  19. 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

  20. 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)

  1. Refractory anastomotic bile leaks after orthotopic liver transplantation are associated with hepatic artery disease.

    Science.gov (United States)

    DaVee, Tomas; Geevarghese, Sunil K; Slaughter, James C; Yachimski, Patrick S

    2017-05-01

    Anastomotic bile leaks are common after orthotopic liver transplant (OLT), and standard treatment consists of placement of a biliary endoprosthesis. The objectives of this study were to identify risk factors for refractory anastomotic bile leaks and to determine the morbidity associated with refractory bile leaks after OLT. Consecutive adult patients who underwent ERCP for treatment of post-OLT biliary adverse events between 2009 and 2014 at a high-volume transplant center were retrospectively identified. A refractory leak was defined as a bile leak that persisted after placement of a plastic biliary endoprosthesis and required repeat endoscopic or surgical intervention. Forty-three subjects met study inclusion criteria. Median age was 57 years, and 36 (84%) subjects were men. Refractory bile leaks were diagnosed in 40% of subjects (17/43). Time-to-event analysis revealed an association between refractory bile leaks and the combined outcome of death, repeat transplant, or surgical biliary revision (hazard ratio, 3.78; 95% confidence interval, 1.25-11.45; P = .01). Hepatic artery disease was more common with refractory compared with treatment-responsive bile leaks (53% vs 8%, P = .001). Refractory anastomotic bile leaks after liver transplantation are associated with decreased event-free survival. Hepatic artery disease is associated with refractory leaks. Large-scale prospective studies should be performed to define the optimal management of patients at risk for refractory bile leaks. Copyright © 2017 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  2. Handbook of refractory carbides and nitrides properties, characteristics, processing and applications

    CERN Document Server

    Pierson, Hugh O

    1996-01-01

    Refractory carbides and nitrides are useful materials with numerous industrial applications and a promising future, in addition to being materials of great interest to the scientific community. Although most of their applications are recent, the refractory carbides and nitrides have been known for over one hundred years. The industrial importance of the refractory carbides and nitrides is growing rapidly, not only in the traditional and well-established applications based on the strength and refractory nature of these materials such as cutting tools and abrasives, but also in new and promising fields such as electronics and optoelectronics.

  3. Entinostat in Treating Pediatric Patients With Recurrent or Refractory Solid Tumors

    Science.gov (United States)

    2018-01-24

    Childhood Brain Stem Neoplasm; Childhood Lymphoma; Childhood Solid Neoplasm; Pineal Region Neoplasm; Recurrent Childhood Central Nervous System Neoplasm; Recurrent Childhood Visual Pathway Glioma; Refractory Central Nervous System Neoplasm

  4. Comparison of Ferrous Calcium Silicate Slag and Calcium Ferrite Slag Interactions with Magnesia-Chrome Refractories

    Science.gov (United States)

    Kaur, R. R.; Swinbourne, D. R.; Wadsley, M. W.; Nexhip, C.

    2011-06-01

    The cost of maintaining and eventually replacing refractories as a result of slag attack is a significant cost component in the copper industry. Converting matte to blister copper takes place in reactors lined with direct-bonded magnesia-chrome refractories, and several continuous converting operations use calcium ferrite slag. Unfortunately, the low viscosity of calcium ferrite slag makes it aggressive toward the refractories. Ferrous calcium silicate (FCS) slag has been proposed as a replacement; however, the effect of this slag on magnesia-chrome refractories has not been studied. In this work, the interactions between FCS slag and magnesia-chrome refractory at 1573 K (1300 °C) with an oxygen partial pressure of 10-6 atm were studied and compared with that experienced with calcium ferrite slag under the same conditions. Both slags penetrated the pores in the refractory and caused compositional change in the chromite spinel intergranular bonding phase through cation interdiffusion, which resulted in cracking and debonding of periclase grains. It was observed that the refractory was penetrated much more deeply by calcium ferrite slag than FCS slag because of the higher surface tension and lower viscosity of calcium ferrite slag. As a result, the refractory was attacked less by FCS slag than it was by calcium ferrite slag. It is concluded that the use of FCS slag in continuous copper converting is likely to extend refractory life.

  5. Characterization of the refractory organic matter present in the dust particles of 67P/Churyumov-Gerasimenko.

    Science.gov (United States)

    Fray, Nicolas; Baklouti, Donia; Bardyn, Anaïs; Briois, Christelle; Cottin, Hervé; Engrand, Cécile; Fischer, Henning; Hilchenbach, Martin; Isnard, Robin; Le Roy, Léna; Modica, Paola; Paquette, John; Ryno, Jouni; Stenzel, Oliver; Siljeström, Sandra; Thirkell, Laurent

    2017-04-01

    The Cometary Secondary Ion Mass Analyser (COSIMA), a miniaturized time-of-flight secondary ion mass spectrometer (ToF-SIMS), is one of the dust particle instruments onboard the orbiter of the Rosetta mission that arrived to comet 67P/Churyumov-Gerasimenko in mid-2014. COSIMA analyses the mineral and organic composition of dust particles that are captured on metal targets exposed to space [1, 2]. The mass spectra acquired by COSIMA show that refractory organic matter is ubiquitous in cometary dust particles [2]. The nature of this carbonaceous material will be discussed. We will highlight the abundance of organic matter in these dust particles as well as the nitrogen to carbon elemental ratio of this refractory organic matter. These results obtained on the dust particles of 67P will be compared to those from other astrophysical objects (carbonaceous chondrites, IDPs, micro-meteorites). This comparison could provide clues on the origin and evolution of the cometary organic matter. References: [1] Hilchenbach, M. et al. (2016) ApJ, 816, L32. [2] Schulz, R. et al. (2015) Nature, 518, 216-218. [3] Fray, N. et al. (2016) Nature, 538, 72-74.

  6. 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.

  7. Evaluating the Relationship between Slabbing of Cr2O3/MgO Refractories Used in Steelmaking and Spalling of High Chrome Oxide Refractories Used in Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, J.P.; Thomas, H.; Kwong, K.-S.

    2006-10-01

    Because of its excellent corrosion resistance and high temperature properties, chrome oxide refractories have been used in a number of severe service environments, including steelmaking and gasification. Refractory failure of Cr2O3/MgO or MgO/Cr2O3 refractories in steelmaking can involve a phenomena called slabbing, peeling, or chemical spalling. A similar failure mechanism exists in the high chrome oxide materials used in gasification. Gasifiers contain the reaction between a carbon feedstock, water, and oxygen under reducing conditions; producing H2 and CO used in chemicals or as fuel for power plants. A slagging gasifier typically operates between 1250- 1575°C, and with pressures between 300-1000 psi. Gasification refractory failure is by chemical dissolution and/or by spalling. Spalling is caused by slag penetration of the porous refractory surface and by expansion differences between the penetrated/non-penetrated areas, and is exacerbated by thermal cycling. Similarities between slabbing of steelmaking refractories and spalling of gasification refractories will be discussed.

  8. Facilitation and refractoriness of the electrically evoked compound action potential.

    Science.gov (United States)

    Hey, Matthias; Müller-Deile, Joachim; Hessel, Horst; Killian, Matthijs

    2017-11-01

    In this study we aim to resolve the contributions of facilitation and refractoriness at very short pulse intervals. Measurements of the refractory properties of the electrically evoked compound action potential (ECAP) of the auditory nerve in cochlear implant (CI) users at inter pulse intervals below 300 μs are influenced by facilitation and recovery effects. ECAPs were recorded using masker pulses with a wide range of current levels relative to the probe pulse levels, for three suprathreshold probe levels and pulse intervals from 13 to 200 μs. Evoked potentials were measured for 21 CI patients by using the masked response extraction artifact cancellation procedure. During analysis of the measurements the stimulation current was not used as absolute value, but in relation to the patient's individual ECAP threshold. This enabled a more general approach to describe facilitation as a probe level independent effect. Maximum facilitation was found for all tested inter pulse intervals at masker levels near patient's individual ECAP threshold, independent from probe level. For short inter pulse intervals an increased N1P1 amplitude was measured for subthreshold masker levels down to 120 CL below patient's individual ECAP threshold in contrast to the recreated state. ECAPs recorded with inter pulse intervals up to 200 μs are influenced by facilitation and recovery. Facilitation effects are most pronounced for masker levels at or below ECAP threshold, while recovery effects increase with higher masker levels above ECAP threshold. The local maximum of the ECAP amplitude for masker levels around ECAP threshold can be explained by the mutual influence of maximum facilitation and minimal refractoriness. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Effectiveness of peripheral neurectomy in refractory cases of trigeminal neuralgia

    Directory of Open Access Journals (Sweden)

    Narayan Sharma Lamichhane

    2016-01-01

    Full Text Available Context: Trigeminal neuralgia (TN is a commonly diagnosed neurosensory disease of orofacial region involving the fifth cranial nerve. Patient refractory to pharmacotherapy or with clinical and/or laboratory side effects sufficient to demand drug cessation is subjected to surgical technique. Aims: The aim of this study is to investigate the efficacy of peripheral neurectomy in the management of refractory TN. Settings and Design: This retrospective study on forty patients refractory to carbamazepine was conducted in the department of oral and maxillofacial surgery in the Northeast part of China from September 2011 to September 2014. Patients and Methods: Patients treated with neurectomy were followed up at regular intervals to assess the duration of pain-free period, and the pain was assessed using visual analog scale and the success of the surgery was defined accordingly. Statistical Analysis Used: Descriptive statistical analysis was carried out using IBM SPSS-20. Results: The mean age of the patients was 67.92 years (46–86 years, with higher incidence in females (F:M = 1.6:1. The 3rd division of trigeminal nerve was most commonly affected by the disease. The right side was more common than the left side. Duration of postsurgical pain-free period varied from 12 to 36 months with mean pain-free duration of 23.25 months. Recurrent cases were treated with low dose of carbamazepine, and majority of them were relieved of symptoms. Conclusions: Peripheral neurectomy is a minimal invasive surgery; safe and effective for elderly patients, especially in rural areas where advanced neurosurgical facilities are not available and for those who are reluctant to major neurosurgical procedures.

  10. [PAD regimen for relapsed or refractory patients with multiple myeloma].

    Science.gov (United States)

    Zhang, Yong-Qing; Liang, Rong; Bai, Qing-Xian; Zhang, Tao; Yang, Lan; Wang, Yi-Wei; Wang, Wen-Qing; Gu, Hong-Tao; Shu, Mi-Mi; Zhu, Hua-Feng; Bai, Yan-Ni; Chen, Xie-Qun

    2009-04-01

    To investigate the efficacy and safety of PAD [bortezomib (PS-341), doxorubicin and dexamethasone] regimen for relapsed or refractory multiple myeloma (MM). Seventeen patients with relapsed or refractory MM received two to four 21-day cycles of PAD: an intravenous bolus of bortezomib (1.3 mg/m2) on days 1, 4, 8, and 11; doxorubicin 10 mg per day on days 1 to 4, and dexamethasone 40 mg on days 1-4. Response was evaluated according to International Myeloma Working Group Criteria (IMWG 2006), toxicity was graded according to NCI CTCAE (common terminology criteria for adverse events) v 3.0. After 2-4 courses of PAD, 14 patients (82.4%) response, including complete response (CR) in 4 (23.5%), very good partial response (VGPR) in 4 (23.5%), partial response (PR) in 6 (35.3%) and stable disease (SD) in 3 (17.6%). Median time to progression was 9.5 months. The median course to response was 1.6 (1-3). All of 5 patients with extramedullary plasmacytoma achieved at least PR after the first cycle therapy; the plasmacytoma disappeared after 1-2 cycles of PAD. The efficacy was independent of other prognostic factors such as beta2-MG. Adverse events included thrombocytopenia in 9 patients (52.9%), leukopenia in 4 (23.5%), peripheral neuropathy in 4 (23.5%), varicella herpes zoster in 3 (17.6%), fatigue in 6 (35.3%) and diarrhea in 2 (11.7%). All of these adverse reactions could be controlled with routine supportive treatment, only one patient died from respiratory failure during his fifth PAD cycle. PAD regimen should be considered as an appropriate treatment for relapsed or refractory MM, especially for MM with extramedullary plasmacytoma. Its efficacy is independent of traditional prognostic factors. The side effects are usually manageable.

  11. Correlation between Corneal Thickness and Degree of Myopic Refractory Error

    Directory of Open Access Journals (Sweden)

    A Mortazavi

    2005-01-01

    Full Text Available Background: corneal thickness is an important factor in refractive surgeries such as Radial Keratotomy (RK, Photo Refractive Keratotomy (PRK and Laser Insitu Keratomileusis (LASIK. This study evaluated the correlation between this factor and the degree of myopic refractory error. Methods: In this cross-sectional study, 224 myopic eyes (112 patients which had undergone LASIK operation were assessed. These patients had referred to Aban Eye Clinic, Isfahan, Iran, during August and September 2002. Corneal thickness was measured by ORB SCAN Topoghraphy, and cycloplegic refraction was performed with autorefratometery and retinoscopy. Suspected keratoconus cases and hyperopic patients were excluded. Results: The patients' age was 27.2 ± 1.36 in men (N = 35 and 30.13 ± 1.04 in women (N = 77. Mean value of myopic refractory error in male patients was 5.1 ± 0.24D and in female patients was 3.8 ± 0.36D. Mean of corneal thickness was 540 ± 5.25 µM and 530 ± 5.88 µM in male and female patients respectively. There was no correlation between the degree of myopia and corneal thickness in any of the patients. Also in this research, no relations between the age and myopia were found. Right eye (P > 0.5, r = 0.124 Left eye (P > 0.5, r = 0.104. Conclusion: Based on our findings, corneal thickness and myopic refectory error do not seem to have any relations. (r = 0.039, p = 0.684. Keywords: Corneal Thickness, Cornea, Myopia, LASIK, Refractory Error

  12. Dexmedetomidine for refractory adrenergic crisis in familial dysautonomia.

    Science.gov (United States)

    Dillon, Ryan C; Palma, Jose-Alberto; Spalink, Christy L; Altshuler, Diana; Norcliffe-Kaufmann, Lucy; Fridman, David; Papadopoulos, John; Kaufmann, Horacio

    2017-02-01

    Adrenergic crises are a cardinal feature of familial dysautonomia (FD). Traditionally, adrenergic crises have been treated with the sympatholytic agent clonidine or with benzodiazepines, which can cause excessive sedation and respiratory depression. Dexmedetomidine is a centrally-acting α 2-adrenergic agonist with greater selectivity and shorter half-life than clonidine. We evaluated the preliminary effectiveness and safety of intravenous dexmedetomidine in the treatment of refractory adrenergic crisis in patients with FD. Retrospective chart review of patients with genetically confirmed FD who received intravenous dexmedetomidine for refractory adrenergic crises. The primary outcome was preliminary effectiveness of dexmedetomidine defined as change in blood pressure (BP) and heart rate (HR) 1 h after the initiation of dexmedetomidine. Secondary outcomes included incidence of adverse events related to dexmedetomidine, hospital and intensive care unit (ICU) length of stay, and hemodynamic parameters 12 h after dexmedetomidine cessation. Nine patients over 14 admissions were included in the final analysis. At 1 h after the initiation of dexmedetomidine, systolic BP decreased from 160 ± 7 to 122 ± 7 mmHg (p = 0.0005), diastolic BP decreased from 103 ± 6 to 65 ± 8 (p = 0.0003), and HR decreased from 112 ± 4 to 100 ± 5 bpm (p = 0.0047). The median total adverse events during dexmedetomidine infusion was 1 per admission. Median hospital length of stay was 9 days [interquartile range (IQR) 3-11 days] and median ICU length of stay was 7 days (IQR 3-11 days). Intravenous dexmedetomidine is safe in patients with FD and appears to be effective to treat refractory adrenergic crisis. Dexmedetomidine may be considered in FD patients who do not respond to conventional clonidine and benzodiazepine pharmacotherapy.

  13. Staging operation in the treatment of refractory glaucoma

    Directory of Open Access Journals (Sweden)

    Yu-Wei Gao

    2016-02-01

    Full Text Available AIM:To analyze the clinical results of cyclophotocoagulation followed by other anti-glaucoma surgeries in the treatment of refractory glaucoma.METHODS:The clinical data of 30 patients(30 eyeswith refractory glaucoma were retrospectively analyzed from January 2013 to July 2014 in Beijing Huade Hospital, including 12 females and 18 males, with an average age of 56 years. Among the 30 eyes, there were 2 eyes with acute angle-closure glaucoma, 4 eyes with over mature cataract, 6 eye with intumescent cataract, 5 eyes with neovascular glaucoma,9 eyes with hard-to-controlled glaucoma even after surgeries,4 eyes with secondary glaucoma after vitrectomy. Diode laser transscleral cyclophotocoagulation was applied to all patients as the primary choice. If the intraocular pressure(IOPwas not well controlled, a secondary anti-glaucoma surgery was applied. RESULTS:During the follow-up period, all of the 30 eyes had satisfactory results, with no complications during or after the operations. The average pre-operative IOP was 62.79±5.59mmHg, which dropped to 32.84±8.16mmHg at 1wk after cyclophotocoagulation. Six of 30 eyes had totally normal IOP, the rest 24 cases underwent another anti-glaucoma operation, after which the IOP decreased to a normal range and in which no complication occurred.CONCLUSION:In the treatment of refractory glaucoma, applying cyclophotocoagulation first to control the IOP can greatly reduce risk of complications during the secondary surgeries. According to their original categories, further anti-glaucoma surgery can reduce the IOP to a safe and effective range.

  14. Maintenance plasma exchange therapy for steroid-refractory neuromyelitis optica.

    Science.gov (United States)

    Khatri, Bhupendra O; Kramer, John; Dukic, Mary; Palencia, Mauricio; Verre, William

    2012-01-01

    Neuromyelitis optica (NMO) is a severe inflammatory demyelinating disease of the central nervous system with exacerbations involving the optic nerves, spinal cord, or both. This study explores the utility of maintenance plasma exchange (mTPE) as a therapy in patients with relapsing, corticosteroid-refractory, NMO. This retrospective case series presents data on patients who were diagnosed with NMO using currently accepted criteria. These patients were refractory to high-dose corticosteroids and received mTPE. Seven patients met the criteria for NMO diagnosis and all were positive for antibodies against aquaporin-4. Over a mean of 7.1 years (range, 2-16), these patients received between 21 and 154 TPE treatments (mean, 76). Although treated with mTPE, five out of the seven patients improved by more than one point on the Expanded Disability Status Scale. Interruption in mTPE in five patients resulted in clinical worsening. When mTPE was restarted in three out of the five patients who experienced a cessation of mTPE, these patients either stabilized or improved. The two patients who did not restart the mTPE protocol died. Patients treated with mTPE also experienced a reduction in the number of NMO exacerbations. Finally, stabilization of the retinal nerve fiber layer thickness was observed while on mTPE. In this preliminary study, mTPE appeared safe and may bring about improvement in disability and sustained stabilization of the clinical course in patients with steroid-refractory relapsing forms of NMO. Copyright © 2012 Wiley Periodicals, Inc.

  15. Rapid clozapine titration in treatment-refractory bipolar disorder.

    Science.gov (United States)

    Ifteni, Petru; Correll, Christoph U; Nielsen, Jimmi; Burtea, Victoria; Kane, John M; Manu, Peter

    2014-09-01

    Clozapine is effective in treatment-refractory bipolar disorder (BD). Guidelines recommend slow titration to prevent seizures, hypotension and myocarditis, but this stance is not supported by comparative data. To evaluate the safety and effectiveness of rapid clozapine titration in BD. Analysis of a consecutive cohort of treatment-refractory BD patients with mixed/manic episode admitted on alternate days to one of two units of a psychiatric hospital. On one unit, clozapine was started at 25mg followed by 25-50mg as needed every 6h (maximum=100mg/day) on day 1, followed by increases of 25-100mg/day. On the other unit, clozapine was initiated with 25mg in day 1, followed by increases of 25-50mg/day. The primary outcome was the number of days from starting clozapine until readiness for discharge, adjusted in logistic regression for the number of antipsychotics tried during the hospitalization, psychotropic co-treatments and presence of psychotic features. Patients subject to rapid (N=44) and standard (N=23) titration were similar in age, gender, smoking status, body mass index, illness severity at baseline and discharge, and highest clozapine dose. Clozapine was discontinued due to hypotension (N=1) and pneumonia (N=1) during rapid titration, and for excessive sedation (N=1) in each titration group. The number of hospital days from starting clozapine until readiness for discharge was 3.8 days shorter in the rapid titration group (12.7±6.3 vs. 16.5±5.8, p=0.0077). Rapid clozapine titration appeared safe and effective for treatment-refractory BD. The potential for shorter hospital stays justifies prospective trials of this method. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Metallization failures

    Science.gov (United States)

    Beatty, R.

    1971-01-01

    Metallization-related failure mechanisms were shown to be a major cause of integrated circuit failures under accelerated stress conditions, as well as in actual use under field operation. The integrated circuit industry is aware of the problem and is attempting to solve it in one of two ways: (1) better understanding of the aluminum system, which is the most widely used metallization material for silicon integrated circuits both as a single level and multilevel metallization, or (2) evaluating alternative metal systems. Aluminum metallization offers many advantages, but also has limitations particularly at elevated temperatures and high current densities. As an alternative, multilayer systems of the general form, silicon device-metal-inorganic insulator-metal, are being considered to produce large scale integrated arrays. The merits and restrictions of metallization systems in current usage and systems under development are defined.

  17. A Direct Refractory Die Technique for Cast Gold Restorations.

    Science.gov (United States)

    Smith, C T; Diefenderfer, K E

    Fabricating accurate cast gold restorations can be challenging for both clinicians and laboratory technicians. Removing the wax pattern from the master die often distorts the pattern, which, in turn, compromises the overall fit and marginal adaptation of the casting. This article demonstrates a laboratory technique in which the final restoration is cast directly on the refractory die without removing the wax pattern. Thus, distortion of the wax pattern is avoided, enabling the production of superbly fitting gold castings for both intracoronal and extracoronal restorations.

  18. Novel Engineered Refractory Materials for Advanced Reactor Applications

    Energy Technology Data Exchange (ETDEWEB)

    Shannon, Steven [North Carolina State Univ., Raleigh, NC (United States); Eapen, Jacob [North Carolina State Univ., Raleigh, NC (United States); Maria, Jon-Paul [North Carolina State Univ., Raleigh, NC (United States); Weber, William [Univ. of Tennessee, Knoxville, TN (United States)

    2016-03-14

    This report summarizes the results of DOE-NEUP grant 10-853. The project spanned 48 months (36 months under the original grant plus a 12 month no cost extension). The overarching goal of this work was to fabricate and characterize refractory materials engineered at the atomic scale with emphasis on their tolerance to accumulated radiation damage. With an emphasis on nano-scale structure, this work included atomic scale simulation to study the underlying mechanisms for modified radiation tolerance at these atomic scales.

  19. Extremely refractory Kawasaki disease with disseminated intravascular coagulation.

    Science.gov (United States)

    Koh, Young Kwon; Lee, Jae Hee; Park, Yeong Bong

    2017-07-01

    Disseminated intravascular coagulation is a rare complication of Kawasaki disease and appears in Kawasaki disease patients. We report a case of refractory Kawasaki disease complicated with disseminated intravascular coagulation and giant coronary aneurysm. A 5-month-old boy presented with Kawasaki disease with coagulopathy. Although the coagulopathy improved after fresh-frozen plasma and antithrombin-III administration, the fever persisted despite two rounds of intravenous immunoglobulin, along with intravenous methylprednisolone pulse therapy and infliximab administration. Despite all efforts to treatment, the patient had giant coronary aneurysms and died suddenly.

  20. Refractory Immunological Thrombocytopenia Purpura and Splenectomy in Pregnancy

    Directory of Open Access Journals (Sweden)

    Santiago Bernal-Macías

    2015-01-01

    Full Text Available Thrombocytopenia is defined as a platelet count of less than 100,000 platelets per microlitre (mcL. Thrombocytopenia develops in approximately 6-7% of women during pregnancy and at least 3% of these cases are caused by immunological platelet destruction. Herein, we present a pregnant woman who develops at the first trimester autoimmune thrombocytopenia purpura associated with positive antiphospholipid antibodies. The disease was refractory to pharmacological treatments but had a favourable response to splenectomy. The patient carried the pregnancy to term without complication and gave birth to a healthy baby girl.

  1. Trace Element Abundances in Refractory Inclusions from Antarctic Micrometeorites

    Science.gov (United States)

    Greshake, A.; Hoppe, P.; Bischoff, A.

    1995-09-01

    Refractory inclusions are charcteristic components in carbonaceous chondrites. Therefore, refractory inclusions found in micrometeorites can give important hints about the relationship between micrometeorites and carbonaceous chondrites. So far, only a few inclusions were found in micrometeorites [1-4]. In this study we report the first trace element analysis of perovskite and fassaite found in micrometeorites. We studied two Antarctic micrometeorites by ASEM, EMP, and SIMS. The first particle is 120 micrometers in size mainly consisting of a fine-grained matrix of dehydrated former phyllosilikates that enclose a 5 micrometers sized perovskite [5]. The perovskite is surrounded by a 1 micrometers thick rim of ilmenite and contains up to 1.3 wt% FeO as determined by EMP. The trace element abundances were determined by SIMS following the procedure described by [6]. The REE pattern of the perovskite is shown in Fig. 1. The pattern is closely related to the Group II pattern with its typical depletion of the more refractory REEs [7]. It is also very similar to the REE abundances of perovskite from Murchison (CM) [8] and CH-chondrites [9]. This may indicate a relationship between this micrometeorite and components in carbonaceous chondrites. The second micrometeorite is 100 micrometers in size consisting of a fine-grained (20 micrometers across) and a coarse-grained (80 micrometers across) area. Both areas contain fassaite with different chemical compositions. The particle was previously analyzed by Lindstrom and Kloeck [1] without knowing the mineralogy. We carried out SIMS analysis of each area of the micrometeorite separately. The TEE patterns of these two areas are similar and show in general a Group III pattern (20-30x CI) in which the more refractory REEs are not fractionated. The negative Eu anomaly is much more apparent in the coarse-grained area and no Yb anomaly is apparent in one of the areas. This is the first CAI of a micrometeorite showing a Group III REE

  2. Epidural blood patch for refractory low CSF pressure headache

    DEFF Research Database (Denmark)

    Madsen, Søren Aalbæk; Fomsgaard, Jonna Storm; Jensen, Rigmor

    2011-01-01

    Once believed an exceedingly rare disorder, recent evidence suggests that low cerebrospinal fluid (CSF) pressure headache has to be considered an important cause of new daily persistent headaches, particularly among young and middle-aged individuals. Treatment of low CSF pressure headache consists...... of non-invasive/conservative measures and invasive measures with epidural blood patch providing the cornerstone of the invasive measures. In the present pilot study we therefore aimed to evaluate the treatment efficacy of epidural blood patch (EBP) in treatment-refractory low-pressure headache. Our...

  3. Amiodarone-Induced Life-Threatening Refractory Hypotension.

    Science.gov (United States)

    Doshi, Deepak; Jayawardana, Ravi

    2015-09-14

    Amiodarone is frequently used in emergency departments for treatment of arrhythmias. Incidence of several amiodarone-related adverse events is unknown. The literature is sparse for potentially life-threatening adverse effects of amiodarone. We present a case of a male patient who presented with chest discomfort and rapid atrial fibrillation. He was known to have paroxysmal atrial fibrillation, which did not respond to initial beta-blocker treatment. The second-line drug amiodarone was given to the patient for rate control. He developed severe hypotension related to amiodarone and required inotropic support along with rapid-sequence intubation. Intravenous amiodarone can cause severe and refractory hypotension.

  4. Plasmapheresis in a patient with "refractory" urticarial vasculitis.

    Science.gov (United States)

    Kartal, Ozgur; Gulec, Mustafa; Caliskaner, Zafer; Nevruz, Oral; Cetin, Turker; Sener, Osman

    2012-07-01

    Immune complexes are found in the circulation of 30%-75% of patients with urticarial vasculitis and much evidence supports the role of these immune complexes in the pathogenesis of urticarial vasculitis. Plasmapheresis is effective for removing these immune complexes; however, there are few reports on the use of plasmapheresis in the treatment of urticarial vasculitis. We describe a case of "refractory" urticarial vasculitis in which the symptoms improved after plasmapheresis treatment. We suggest that plasmapheresis be considered as an option in patients with severe or treatment-resistant urticarial vasculitis.

  5. Glatiramer Acetate-associated Refractory Immune Thrombocytopenic Purpura

    Directory of Open Access Journals (Sweden)

    Iftach Sagy

    2016-04-01

    Full Text Available We present a case of glatiramer acetate-associated refractory immune thrombocytopenic purpura (ITP in a female patient with multiple sclerosis. A search of MEDLINE/PubMed did not find any connection between glatiramer acetate and thrombocytopenia, specifically ITP. The autoimmune reaction was resistant to conservative ITP treatment, and was eventually managed only by splenectomy. To the best of our knowledge, this is the first report of glatiramer acetate-associated ITP. Physicians should be aware of this condition, and consider performing routine blood counts at the beginning of glatiramer acetate treatment.

  6. Geology and Refractory Clay Deposits of the Haldeman and Wrigley Quadrangles, Kentucky

    Science.gov (United States)

    Patterson, Sam H.; Hosterman, John W.; Huddle, John Warfield

    1962-01-01

    mixtures of kaolinite, illite, and mixed-layer clays by leaching in swamps to the deposition of the beds overlying the clay. The refractory properties of the clay vary directly with the purity of the kaolinite, and refractoriness decreases as the proportions of illite and mixed-layer clays increase. Certain nonclay minerals, chiefly siderite, pyrite, and iron oxide-bearing minerals, also act as fiuxes, reducing the refractory properties of the clay. The entire resources of clay in the Olive Hill clay bed are roughly and tentatively estimated to include 105,000,000 tons in the Haldeman quadrangle and 175,000,000 tons in the Wrigley quadrangle. Much of this clay is of poor quality and the amount that is better than the minimum requirements for use in refractories is probably about 30,000,000 tons. Only a fraction of this tonnage is suitable for superheat-duty products. Limestone is the only nonmetallic mineral resource other than refractory clay that has been developed in the two quadrangles, but 1arge amounts of shale suitable for use in making lightweight aggregate and structural clay products may also be present. Most of the limestone, which is quarried. in both quadrangles, is used for road-metal, concrete aggregate, and agriculture stone, but some of the limestone is of the quality that would be suitable for other uses. Virtually all the Mississippian Beech Creek limestone of Malott, 1919 which is as much as 18 feet thick, consists of high-calcium limestone. Shale beds that appear most favoralble for making lightweight aggregate are in the shale facies of the Lee formation of Pennsylvanian age. Shale that is probably suitable for structural clay products is present in the shale flacles of the Lee formation and in the Muldraugh formation of Mississippian age. Several dry holes have been drilled in search for oil and gas within the area of the two quadrangles. Though no commercial production was ever attained, one well furnished a supply of gas f

  7. Iodine I 131 Monoclonal Antibody BC8 Before Autologous Stem Cell Transplant in Treating Patients With Relapsed or Refractory Hodgkin Lymphoma or Non-Hodgkin Lymphoma

    Science.gov (United States)

    2017-11-15

    Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Hodgkin Lymphoma; Recurrent T-Cell Non-Hodgkin Lymphoma; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Hodgkin Lymphoma; Refractory T-Cell Non-Hodgkin Lymphoma

  8. Application of ceramic coating to improve abrasive wear resistance of die inserts used to press-mould stampings of refractories

    Directory of Open Access Journals (Sweden)

    A. W. Orłowicz

    2017-01-01

    Full Text Available The paper presents results of a study on abrasive wear resistance of die inserts for composite moulds used to pressmould stampings from refractory materials, determined based on susceptibility to scratching with a diamond indenter. For the study, two inserts of high-chromium cast iron were prepared, of which one was provided with a ceramic coating (60 % Al2O3 + 40 % TiO2 with a metallic interlayer (NiAlCrSi. Both layers were deposited by means of the Atmospheric Plasma Spraying (APS method. The obtained scratch test results indicate that with the use of the same load force (20 N, die inserts with ceramic coating are characterized with less indenter penetration depth which should translate to higher resistance to abrasive wear.

  9. Model for temperature profile estimation in the refractory of a metallurgical ladle

    Science.gov (United States)

    Fredman, T. P.; Saxén, H.

    1998-06-01

    Modeling of the transient thermal state of metallurgical ladels is motivated by the need for estimating the drop in temperature of the liquid metal in the ladle. On-line estimation of the state is required, since the same ladle is used in a number of casting cycles with rapid changes in boundary conditions for the temperature field, and the conditions in the current as well as previous cycles affect the thermal state. Although a large number of methods for the numerical solution of conduction-diffusion partial differential equations have been developed, there are still advantages to keeping thermal field computations at a relatively simple level, in contrast to the situation in the design process of ladles, where two-dimensional modeling may be required. Extensive computations under nonverifiable boundary and initial parameter values are not especially suited for real-time simulation of industrial processes. This article presents a novel approach to the solution of the one-dimensional transient heat conduction problem applied to ladle linings, relying on classical analytical techniques in combination with numerical methods. The performance of the model was validated by a comparison of predictions to thermocouple measurements from the refractory of a steelmaking ladle during a campaign of 26 casting cycles. Reasonable agreement between the measured and simulated variables could be established, which demonstrates the feasibility of the approach.

  10. A noncontact measurement technique for the specific heat and total hemispherical emissivity of undercooled refractory materials

    Science.gov (United States)

    Rulison, Aaron J.; Rhim, Won-Kyu

    1994-03-01

    A noncontact measurement technique for the constant pressure specific heat (cpl) and the total hemispherical emissivity (ɛTl) of undercooled refractory materials is presented. In purely radiative cooling, a simple formula which relates the post-recalescence isotherm duration and the undercooling level to cpl is derived. This technique also allows us to measure ɛTl once cpl is known. The experiments were performed using the high-temperature high-vacuum electrostatic levitator at JPL in which 2-3 mm diameter metallic samples can be levitated, melted, and radiatively cooled in vacuum. The averaged specific heats and total hemispherical emissivities of Zr and Ni over the undercooled regions agree well with the results obtained by drop calorimetry: cpl,av(Zr)=40.8±0.9 J/mol K, ɛTl,av(Zr)=0.28±0.01, cpl,av(Ni)=42.6±0.8 J/mol K, and ɛTl,av(Ni)=0.16±0.01.

  11. 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.

  12. Lenalidomide for the treatment of relapsed and refractory multiple myeloma

    Science.gov (United States)

    van de Donk, Niels WCJ; Görgün, Güllü; Groen, Richard WJ; Jakubikova, Jana; Mitsiades, Constantine S; Hideshima, Teru; Laubach, Jacob; Nijhof, Inger S; Raymakers, Reinier A; Lokhorst, Henk M; Richardson, Paul G; Anderson, Kenneth C

    2012-01-01

    Lenalidomide is an amino-substituted derivative of thalidomide with direct antiproliferative and cytotoxic effects on the myeloma tumor cell, as well as antiangiogenic activity and immunomodulatory effects. Together with the introduction of bortezomib and thalidomide, lenalidomide has significantly improved the survival of patients with relapsed and refractory myeloma. The most common adverse events associated with lenalidomide include fatigue, skin rash, thrombocytopenia, and neutropenia. In addition, when lenalidomide is combined with dexamethasone or other conventional cytotoxic agents, there is an increase in the incidence of venous thromboembolic events. There is now evidence that continued treatment with lenalidomide has a significant impact on survival by improving the depth and duration of response. This highlights the value of adverse event management and appropriate dose adjustments to prevent toxicity, and of allowing continued treatment until disease progression. In this review, we will discuss the different lenalidomide-based treatment regimens for patients with relapsed/refractory myeloma. This is accompanied by recommendations of how to manage and prevent adverse events associated with lenalidomide-based therapy. PMID:22956884

  13. Mechanical and Physicochemical Evaluation of Alkaleri Fireclay for Refractory Application

    Directory of Open Access Journals (Sweden)

    Job Ajala Amkpa

    2017-04-01

    Full Text Available The mechanical, chemical and physical property of Alkaleri fireclay was investigated for its appropriateness for refractory application. The chemical composition was performed and analyzed using the X-ray fluorescence (XRF spectrometer Bench top XRF analyzer technique. Chemical property result indicated that the clay contained 67.4 % silica (SiO2, 30.06 % aluminum (Al2O3, and other impurities. The clay was subjected to mechanical activation through sintering process at varied sintering temperatures of 900 °C, 1000 °C, 1100 °C and 1200 °C. At the best sintering temperature of 1200 °C, the cold crushing strength (CCS was 17.82 MPa, in the physical properties; apparent porosity was 22.8 %, bulk density was 1.8 g/cm3, and firing shrinkage was 8.9 %. The Alkaleri clay belongs to alumino-silicate fireclay group and therefore, suitable materials for refractory application of ladle, kiln dryer, boilers, cook stoves, furnace lining and bricks.

  14. Preoperative neuropsychological presentation of patients with refractory frontal lobe epilepsy.

    Science.gov (United States)

    Patrikelis, Panayiotis; Gatzonis, Stylianos; Siatouni, Anna; Angelopoulos, Elias; Konstantakopoulos, George; Takousi, Maria; Sakas, Damianos E; Zalonis, Ioannis

    2016-06-01

    This study investigated whether certain cognitive deficits are associated with frontal lobe epilepsy (FLE) aiming to contribute with localization data to the preoperative assessment of epilepsy surgery candidates. We evaluated 34 patients with refractory FLE, 37 patients with refractory medial temporal lobe epilepsy (MTLE), and 22 healthy individuals in attention, psychomotor speed, motor function, verbal memory span, verbal fluency, response inhibition/interference, concept formation and set shifting, anticipation and planning, global memory. Neuropsychological performances of FLE and MTLE were similar, with the only exception the WCST-number of categories index, measuring mental flexibility, in which MTLE patients performed significantly worse than FLE patients. Left-FLE patients presented more perseverative responding compared to both other patient groups and healthy controls (HCs), while left-MTLE patients showed worse sorting abilities than the other epilepsy groups. Our findings suggest a weak cognitive differentiation between FLE and MTLE, probably attributed to the intricate nature of fronto-temporal connectivity frequently resulting in overlapping deficits as well as the confounding effects of seizure-related variables. In clinical practice, a highly individualized (idiographic) neuropsychological approach along with the inclusion of concurrent EEG recordings (e.g., interictal coupling) may be of help for neuropsychologists in identifying FLE patients from those with medial temporal pathology presenting frontal dysfunction as a secondary cognitive symptom.

  15. Open and Laparoscopic Colposuspension in Girls with Refractory Urinary Incontinence

    Directory of Open Access Journals (Sweden)

    Barbara Anna Dobrowolska-Glazar

    2017-12-01

    Full Text Available IntroductionLower urinary tract symptoms (LUTS are very common in children. Standard treatments consist of urotherapy, antibiotic prophylaxis, anti-muscarinics, physical therapy, and the treatment of coexisting constipation. A small group of girls also present with stress incontinence or with stress-induced urge incontinence. In cases of persistent LUTS due to congenital bladder neck insufficiency (BNI, surgical treatment might be considered. The aim of this paper is to assess the results of open and laparoscopic colposuspension in children with refractory urinary incontinence (UI.Materials and methodsThe results of 18 open and 18 laparoscopic consecutive colposuspensions were analyzed. All patients had UI and failed conservative treatment. BNI was proven by repeated perineal ultrasound and video-urodynamic study. The laparoscopic procedure was performed preperitoneally and the open procedure was via a transverse lower abdominal incision. The same postoperative protocol was used in both groups.ResultsThe mean operation time was 65 min for the open and 90 min for the lap procedure (p < 0.05. Full success was achieved in 7/18 in the open and in 8/18 in the lap group and partial response was seen in 3/18 and in 5/18, respectively (p = 0.64. No intraoperative complications occurred in this cohort.ConclusionOpen and laparoscopic colposuspension can be used to treat refractory UI in children with BNI when non-invasive methods fail.

  16. Barbiturate-refractory epilepsy: safe schedule for therapeutic substitution

    Directory of Open Access Journals (Sweden)

    Ana Maria Gorz

    1986-09-01

    Full Text Available Barbiturates are considered first line antiepileptic drugs in third world countries due to traditional and economic reasons. This prospective uncontrolled study of 52 patients aged 15 to 64 years (mean 24 demonstrates that patients who become refractory to barbiturates are mainly those with partial seizures with or without generalization or with a focal EEG abnormality (71%. Seizures tend to become refractory approximately 6 years after barbiturates were started. Progressive barbiturate withdrawal over a period of two to 8 months (mean 5 with institution of treatment with carbamazepine, phenytoin or sodium valproate allowed complete barbiturate withdrawal in 42 of the 52 patients (81%. Furthermore monthly seizure frequency in those in whom barbiturates were withdrawn decreased from 7.1 to 1.7 per patient. An improvement in mental status was observed but not measured. These results show that barbiturates should not be first-choice drugs in patients who have a chronic disease such as epilepsy, and indicate a schedule for barbiturate withdrawal Which is safe and independent of hospitalization or monitoring of antiepileptic drug serum concentrations.

  17. Erbium:YAG laser resurfacing for refractory melasma.

    Science.gov (United States)

    Manaloto, R M; Alster, T

    1999-02-01

    Melasma is a facial dyspigmentation which is a common complaint in patients with darker skin tones. Many current therapies used for this condition are ineffective and can cause significant adverse effects. The purpose of this study was to evaluate the role of erbium:YAG laser resurfacing in the management of refractory melasma. Ten female patients with melasma unresponsive to previous therapy of bleaching creams and chemical peels were included in this study. Full face skin resurfacing using an erbium: YAG laser (2.94 microm) was performed using 5.1-7.6 J/cm2 energy. Clinical evaluations using the Melasma Area and Severity Index (MASI) and melanin reflectance spectrometry measurements were taken preoperatively and at 0.5, 1, 1.5, 3, and 6 weeks and 3, 5, and 6 months postoperatively. Adverse effects after laser resurfacing such as prolonged erythema, infection, and hyperpigmentation were recorded. There was marked improvement of the melasma immediately after laser surgery using the parameters outlined; however, between 3 and 6 weeks postoperatively, all patients exhibited post-inflammatory hyperpigmentation. Decreased MASI and melanin reflectance spectrometry measurement scores were noted after biweekly glycolic acid peels and at the end of 6 months, significant clinical improvement in the melasma was seen compared to the preoperative evaluation. Erbium:YAG laser resurfacing effectively improves melasma; however, the almost universal appearance of transient post-inflammatory hyperpigmentation necessitates prompt and persistent intervention. The use of this laser therapy is recommended only for refractory melasma.

  18. Occupational outcome after temporal lobectomy for refractory epilepsy.

    Science.gov (United States)

    Sperling, M R; Saykin, A J; Roberts, F D; French, J A; O'Connor, M J

    1995-05-01

    We evaluated employment after temporal lobectomy for refractory epilepsy in 86 patients (3.5 to 8 years of follow-up). Seventy-three patients qualified for the work force before and after surgery. Unemployment rates declined after surgery (18 patients [25%] unemployed before surgery, eight patients [11%] unemployed after surgery), and underemployment also tended to diminish. Improvement in occupational status related strongly to the degree of postoperative seizure relief. Seizure-free patients fared better (no unemployment, little underemployment) than patients with some seizure-free years and some years with seizures after surgery, whose high underemployment level persisted. Patients with seizures in each year after surgery fared worst (despite reduced seizure frequency), with increased unemployment after surgery. Age at surgery also influenced vocational outcome in patients who were unemployed before surgery. Historical, educational, cognitive, and behavioral measures did not correlate with vocational outcome. Employment gains came slowly; unemployed patients took up to 6 years to obtain work after surgery. Of 13 students at the time of surgery, 11 have graduated and nine are now employed. We conclude that seizures play a large role in limiting employment, and that by alleviating seizures, temporal lobectomy improves employability in people with refractory epilepsy. Surgery thereby provides benefit to individuals with epilepsy by increasing financial independence and to society by reducing unemployment.

  19. Hyperbaric oxygen therapy for refractory radiation-induced hemorrhagic cystitis.

    Science.gov (United States)

    Ribeiro de Oliveira, Tiago M; Carmelo Romão, António J; Gamito Guerreiro, Francisco M; Matos Lopes, Tomé M

    2015-10-01

    To analyze the efficacy of hyperbaric oxygen for the treatment of radiation-induced hemorrhagic cystitis and to identify factors associated with successful treatment. Clinical records from 176 patients with refractory radiation-induced hemorrhagic cystitis treated at the Portuguese Navy Center for Underwater and Hyperbaric Medicine, during a 15-year period, were retrospectively analyzed. Evolution of macroscopic hematuria was used to analyze treatment efficacy and correlated with other external variables. From a total of 176 treated patients, 23.9% evidenced other radiation-induced soft tissue lesions. After an average on 37 sessions, 89.8% of patients showed resolution of hematuria, with only 1.7% of adverse events. In our sample, hematuria resolution after treatment with hyperbaric oxygen was statistically associated to the need for transfusion therapy (P = 0.026) and the number of sessions of hyperbaric oxygen (P = 0.042). No relationship was found with the remaining variables. Refractory radiation-induced hemorrhagic cystitis can be successfully and safely treated with hyperbaric oxygen. Treatment effectiveness seems to be correlated with the need for transfusion therapy and the number of sessions performed. © 2015 The Japanese Urological Association.

  20. Rapid Clozapine Titration in Patients with Treatment Refractory Schizophrenia.

    Science.gov (United States)

    Poyraz, Cana Aksoy; Özdemir, Armağan; Sağlam, Nazife Gamze Usta; Turan, Şenol; Poyraz, Burç Çağrı; Tomruk, Nesrin; Duran, Alaattin

    2016-06-01

    The aim of this study is to evaluate the safety and effectiveness of rapid clozapine titration in patients with schizophrenia in hospital settings. We conducted a retrospective two-center cohort study to compare the safety and effectiveness of clozapine with different titration rates in treatment-refractory patients with schizophrenia. In the first center, clozapine was started at 25-50 mg followed by 50-100 mg as needed every 6 h on day 1, followed by increases of 50-100 mg/day. In the second center, titration was slower; clozapine initiated with 12.5-50 mg on day 1 followed by increases of 25-50 mg/day. The number of days between starting of clozapine until discharge was shorter in the rapid titration group (22.4 ± 8.72 vs 27.0 ± 10.5, p = 0.1). Number of days of total hospital stay were significantly shorter in the rapid titration group (29.6 ± 10.6 vs 41.2 ± 14.8, p = 0.002). Hypotension was more common in the rapid titration group and one patient had suspected myocarditis. Rapid clozapine titration appeared safe and effective. The length of stay following initiation of clozapine was shorter in the rapid-titration group, although this was not statistically significant. However starting clozapine earlier together with rapid titration has significantly shortened the length of hospital stay in patients with treatment refractory schizophrenia.