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Sample records for caso4 oxygen carrier

  1. Effect of Gasifying Medium on the Coal Chemical Looping Gasification with CaSO4 as Oxygen Carrier☆

    Institute of Scientific and Technical Information of China (English)

    Yongzhuo Liu; Weihua Jia; Qingjie Guo; Hojung Ryu

    2014-01-01

    The chemical looping gasification uses an oxygen carrier for solid fuel gasification by supplying insufficient lattice oxygen. The effect of gasifying medium on the coal chemical looping gasification with CaSO4 as oxygen carrier is investigated in this paper. The thermodynamical analysis indicates that the addition of steam and CO2 into the system can reduce the reaction temperature, at which the concentration of syngas reaches its maximum value. Experimental result in thermogravimetric analyzer and a fixed-bed reactor shows that the mixture sample goes through three stages, drying stage, pyrolysis stage and chemical looping gasification stage, with the temper-ature for three different gaseous media. The peak fitting and isoconversional methods are used to determine the reaction mechanism of the complex reactions in the chemical looping gasification process. It demonstrates that the gasifying medium (steam or CO2) boosts the chemical looping process by reducing the activation energy in the overall reaction and gasification reactions of coal char. However, the mechanism using steam as the gasifying medium differs from that using CO2. With steam as the gasifying medium, parallel reactions occur in the begin-ning stage, followed by a limiting stage shifting from a kinetic to a diffusion regime. It is opposite to the reaction mechanism with CO2 as the gasifying medium.

  2. Investigation into Syngas Generation from Solid Fuel Using CaSO4-based Chemical Looping Gasification Process

    Institute of Scientific and Technical Information of China (English)

    LIU Yongzhuo; GUO Qingjie

    2013-01-01

    Chemical-looping gasification(CLG)is a novel process for syngas generation from solid fuels,sharing the same basic principles as chemical-looping combustion(CLC).It also uses oxygen carriers(mainly metal oxide and calcium sulfate)to transfer heat and oxygen to the fuel.In this paper,the primary investigation into the CLG process with CaSO4 as oxygen carrier was carried out by thermodynamic analysis and experiments in the tube reactor.Sulfur-contained gas emission was mainly H2S rather than SO2 in the CLG process,showing some different features from the CLC.The mass and heat balance of CLG processes were calculated thermodynamically to determinate the auto-thermal operating conditions with different CaSO4/C and steam/C molar ratios.It was found that the CaSO4/C molar ratio should be higher than 0.2 to reach auto-thermal balance.The effect of temperature on the reactions between oxygen carrier and coal was investigated based on Gibbs free energy minimum method and experimental results.It indicated that high temperature favored the CLG process in the fuel reactor and part of syngas was consumed to compensate for auto-thermal system.

  3. Synthesis gas production using oxygen storage materials as oxygen carrier over circulating fluidized bed

    Institute of Scientific and Technical Information of China (English)

    DAI Xiaoping; YU Changchun; LI Ranjia; WU Qiong; HAO Zhengping

    2008-01-01

    A novel process for synthesis gas production over Circulating Fluidized Bed (CFB) using oxygen storage materials as oxygen carrier was reported. First, oxygen in the air was chemically fixed and converted to lattice oxygen of oxygen storage materials over regenerator, and then methane was selectively oxidized to synthesis gas with lattice oxygen of oxygen storage materials over riser reactor. The results from simulation reaction of CFB by sequential redox reaction on a fixed bed reactor using lanthanum-based perovskite LaFeO3 and La0.8Sr0.2Fe0.9Co0.1O3 oxides prepared by sol-gel, suggested that the depleted oxygen species could be regenerated, and methane could be oxidized to synthesis gas by lattice oxygen with high selectivity. The partial oxidation of methane to synthesis gas over CFB using lattice oxygen of the oxygen storage materials instead of gaseous oxygen should be possibly applicable.

  4. Enhanced optical oxygen sensing using a newly synthesized ruthenium complex together with oxygen carriers.

    Science.gov (United States)

    Ertekin, Kadriye; Kocak, Suleyman; Sabih Ozer, M; Aycan, Sule; Cetinkaya, Bekir

    2003-11-12

    In this article, an emission based, simple and fast method is proposed for the determination of gaseous oxygen. A newly synthesized fluorophore, dichloro-{2,6-bis[1-(4-dimethylamino-phenylimino) ethyl]pyridine}ruthenium(II) has been used for oxygen sensing together with oxygen carrier perfluorochemicals (PFCs) in silicon matrix. It should be noted that the solubility of oxygen in fluorocarbons is about three to ten times large as that observed in the parent hydrocarbons or in water, respectively. Employed PFCs are chemically and biochemically inert, have high dissolution capacities for oxygen, and, once doped into sensing film, considerably enhance the response of sensing agent. PMID:18969220

  5. Natural Ores as Oxygen Carriers in Chemical Looping Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Hanjing; Siriwardane, Ranjani; Simonyi, Thomas; Poston, James

    2013-08-01

    Chemical looping combustion (CLC) is a combustion technology that utilizes oxygen from oxygen carriers (OC), such as metal oxides, instead of air to combust fuels. The use of natural minerals as oxygen carriers has advantages, such as lower cost and availability. Eight materials, based on copper or iron oxides, were selected for screening tests of CLC processes using coal and methane as fuels. Thermogravimetric experiments and bench-scale fixed-bed reactor tests were conducted to investigate the oxygen transfer capacity, reaction kinetics, and stability during cyclic reduction/oxidation reaction. Most natural minerals showed lower combustion capacity than pure CuO/Fe{sub 2}O{sub 3} due to low-concentrations of active oxide species in minerals. In coal CLC, chryscolla (Cu-based), magnetite, and limonite (Fe-based) demonstrated better reaction performances than other materials. The addition of steam improved the coal CLC performance when using natural ores because of the steam gasification of coal and the subsequent reaction of gaseous fuels with active oxide species in the natural ores. In methane CLC, chryscolla, hematite, and limonite demonstrated excellent reactivity and stability in 50-cycle thermogravimetric analysis tests. Fe{sub 2}O{sub 3}-based ores possess greater oxygen utilization but require an activation period before achieving full performance in methane CLC. Particle agglomeration issues associated with the application of natural ores in CLC processes were also studied by scanning electron microscopy (SEM).

  6. Evaluation of different oxygen carriers for biomass tar reforming

    DEFF Research Database (Denmark)

    Mendiara, Teresa; Johansen, Joakim Myung; Utrilla, Rubén;

    2011-01-01

    , in a concentration of 600–2000ppmv, was chosen as a tar model compound. Experiments were performed in a TGA apparatus and a fixed bed reactor. Four oxygen carriers (60% NiO/MgAl2O4 (Ni60), 40% NiO/NiAl2O4 (Ni40), 40% Mn3O4/Mg–ZrO2 (Mn40) and FeTiO3 (Fe)) were tested under alternating reducing/oxidizing cycles...

  7. Evaluation of different oxygen carriers for biomass tar reforming

    DEFF Research Database (Denmark)

    Mendiara, Teresa; Johansen, Joakim Myung; Utrilla, Rubén;

    2011-01-01

    This work is a continuation of a previous paper by the authors [1] which analyzed the suitability of the Chemical Looping technology in biomass tar reforming. Four different oxygen carriers were tested with toluene as tar model compound: 60% NiO/MgAl2O4 (Ni60), 40% NiO/NiAl2O4 (Ni40), 40% Mn3O4/Mg...

  8. Thermal Analysis and Investigation of NiO-Based Oxygen Carriers for Chemical-Looping Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Jerndal, Erik, e-mail: erik.jerndal@chalmers.se

    2009-03-15

    Capture and storage of CO{sub 2} can be used to reduce greenhouse gas emissions from combustion of fossil fuels. Chemical-looping combustion is a two-step combustion process where CO{sub 2} is obtained in a separate stream, ready for compression and storage. The technology uses circulating oxygen carriers to transfer oxygen from an air reactor to a fuel reactor, thus avoiding an energy consuming gas separation unit. A thermal analysis of the process using a large number of possible oxygen carriers was performed by simulating chemical reactions. Based on the ability of the oxygen carriers to convert different gaseous fuels, stability in air and melting temperature some metal oxides based on Ni, Cu, Fe, Mn, Co, W and sulphates of Ba, Sr and Ca showed good thermodynamic properties and could be feasible as oxygen carriers. The promising systems were investigated further with respect to temperature changes in the fuel reactor as well as possible formation of carbon, sulphides and sulphates which may deactivate the oxygen carriers. Oxygen carriers of NiO, supported by NiAl{sub 2}O{sub 4}, were prepared and investigated experimentally with respect to parameters important for chemical-looping combustion. These oxygen carriers were based on commercially available raw materials in contrast to most of the previously tested oxygen carriers, which have been prepared from pure chemicals. Further, it was investigated if spray-drying, which is a production method suitable for large-scale particle preparation, can be used to produce high performing oxygen carriers instead of the small-scale freeze-granulation method. Generally, materials prepared from commercially available raw material showed high reactivity with methane and oxygen. Oxygen carriers prepared by spray-drying, displayed a remarkable similarity when compared to oxygen carriers prepared from the same starting material by freeze-granulation, both regarding physical properties and reactivity. Further, the up-scaling of

  9. Syngas Generation from Methane Using a Chemical-Looping Concept: A Review of Oxygen Carriers

    Directory of Open Access Journals (Sweden)

    Kongzhai Li

    2013-01-01

    Full Text Available Conversion of methane to syngas using a chemical-looping concept is a novel method for syngas generation. This process is based on the transfer of gaseous oxygen source to fuel (e.g., methane by means of a cycling process using solid oxides as oxygen carriers to avoid direct contact between fuel and gaseous oxygen. Syngas is produced through the gas-solid reaction between methane and solid oxides (oxygen carriers, and then the reduced oxygen carriers can be regenerated by a gaseous oxidant, such as air or water. The oxygen carrier is recycled between the two steps, and the syngas with a ratio of H2/CO = 2.0 can be obtained successively. Air is used instead of pure oxygen allowing considerable cost savings, and the separation of fuel from the gaseous oxidant avoids the risk of explosion and the dilution of product gas with nitrogen. The design and elaboration of suitable oxygen carriers is a key issue to optimize this method. As one of the most interesting oxygen storage materials, ceria-based and perovskite oxides were paid much attention for this process. This paper briefly introduced the recent research progresses on the oxygen carriers used in the chemical-looping selective oxidation of methane (CLSOM to syngas.

  10. Combined oxides as oxygen-carrier material for chemical-looping with oxygen uncoupling

    International Nuclear Information System (INIS)

    Highlights: • Manganese-based combined oxides are examined for chemical-looping combustion applications. • Promising compositions includes (MnyFe1−y)Ox, (MnySi1−y)Ox and CaMnO3−δ. • Study includes thermodynamic analysis and overview of current experimental experiences. - Abstract: Oxygen-carrier materials for chemical-looping with oxygen uncoupling (CLOU) must be capable of taking up and releasing gas-phase O2 at conditions relevant for generation of heat and power. In principle, the capability of a certain material to do so is determined by its thermodynamic properties. This paper provides an overview of the possibility to design feasible oxygen carrier materials from combined oxides, i.e. oxides with crystal structures that include several different cations. Relevant literature is reviewed and the thermodynamic properties and key characteristics of a few selected combined oxide systems are calculated and compared to experimental data. The general challenges and opportunities of the combined oxide concept are discussed. The focus is on materials with manganese as one of its components and the following families of compounds and solid solutions have been considered: (MnyFe1−y)Ox, (MnySi1−y)Ox, CaMnO3−δ, (NiyMn1−y)Ox, (MnyCu1−y)Ox and (MnyMg1−y)Ox. In addition to showing promise from a thermodynamic point of view, reactivity data from experimental investigations suggests that the rate of O2 release can be high for all systems. Thus these combined oxides could also be very suitable for practical application

  11. Recovery Act: Novel Oxygen Carriers for Coal-fueled Chemical Looping

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Wei-Ping; Cao, Yan

    2012-11-30

    Chemical Looping Combustion (CLC) could totally negate the necessity of pure oxygen by using oxygen carriers for purification of CO{sub 2} stream during combustion. It splits the single fuel combustion reaction into two linked reactions using oxygen carriers. The two linked reactions are the oxidation of oxygen carriers in the air reactor using air, and the reduction of oxygen carriers in the fuel reactor using fuels (i.e. coal). Generally metal/metal oxides are used as oxygen carriers and operated in a cyclic mode. Chemical looping combustion significantly improves the energy conversion efficiency, in terms of the electricity generation, because it improves the reversibility of the fuel combustion process through two linked parallel processes, compared to the conventional combustion process, which is operated far away from its thermo-equilibrium. Under the current carbon-constraint environment, it has been a promising carbon capture technology in terms of fuel combustion for power generation. Its disadvantage is that it is less mature in terms of technological commercialization. In this DOE-funded project, accomplishment is made by developing a series of advanced copper-based oxygen carriers, with properties of the higher oxygen-transfer capability, a favorable thermodynamics to generate high purity of CO{sub 2}, the higher reactivity, the attrition-resistance, the thermal stability in red-ox cycles and the achievement of the auto-thermal heat balance. This will be achieved into three phases in three consecutive years. The selected oxygen carriers with final-determined formula were tested in a scaled-up 10kW coal-fueled chemical looping combustion facility. This scaled-up evaluation tests (2-day, 8-hour per day) indicated that, there was no tendency of agglomeration of copper-based oxygen carriers. Only trace-amount of coke or carbon deposits on the copper-based oxygen carriers in the fuel reactor. There was also no evidence to show the sulphidization of oxygen

  12. Chemical-Looping Combustion and Gasification of Coals and Oxygen Carrier Development: A Brief Review

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2015-09-01

    Full Text Available Chemical-looping technology is one of the promising CO2 capture technologies. It generates a CO2 enriched flue gas, which will greatly benefit CO2 capture, utilization or sequestration. Both chemical-looping combustion (CLC and chemical-looping gasification (CLG have the potential to be used to generate power, chemicals, and liquid fuels. Chemical-looping is an oxygen transporting process using oxygen carriers. Recently, attention has focused on solid fuels such as coal. Coal chemical-looping reactions are more complicated than gaseous fuels due to coal properties (like mineral matter and the complex reaction pathways involving solid fuels. The mineral matter/ash and sulfur in coal may affect the activity of oxygen carriers. Oxygen carriers are the key issue in chemical-looping processes. Thermogravimetric analysis (TGA has been widely used for the development of oxygen carriers (e.g., oxide reactivity. Two proposed processes for the CLC of solid fuels are in-situ Gasification Chemical-Looping Combustion (iG-CLC and Chemical-Looping with Oxygen Uncoupling (CLOU. The objectives of this review are to discuss various chemical-looping processes with coal, summarize TGA applications in oxygen carrier development, and outline the major challenges associated with coal chemical-looping in iG-CLC and CLOU.

  13. Feasibility study of CaSO4:Eu, CaSO4:Eu,Ag and CaSO4:Eu,Ag(NP) as thermoluminescent dosimeters

    International Nuclear Information System (INIS)

    This work evaluates the dosimetric properties of crystals of CaSO4 doped with unusual elements, such as europium (Eu) and silver (Ag), including their nanoparticle forms, after the incorporation of glass or Teflon and compares them with well-known thermoluminescent dosimeters (TLD). X-ray diffraction analyses showed that samples of doped CaSO4 exhibit only a single phase corresponding to the crystal structure of anhydrite. Optical spectroscopy confirmed the presence of Eu3+ in the crystal matrix and a luminescent gain due the presence of silver nanoparticles. The composites showed thermoluminescent emission glow curves, with a single peak centered at approximately 200 °C for pellets with Teflon and at 230 °C for pellets with glass. The dosimeters based on calcium sulfate doped with europium and silver nanoparticles provided the most intense thermoluminescent (TL) emission of the composites studied. In comparison with commercial TLD, such as LiF:Mg,Ti and CaSO4:Dy, the CaSO4:Eu,Ag(NP)+glass produced in this work presented similar low detection limits and higher sensitivity. The new methods for the preparation of dosimeters and the incorporation of glass are shown to be viable because all of the samples presented a linear, reproducible and first order kinetic TL emission. - Highlights: • Thermoluminescent properties of CaSO4 doped with Eu, Ag and Ag nanoparticles were evaluated. • Crystals were grown using a production route based in the Yamashita method. • Glass or Teflon was incorporate to the crystals in order to obtain composites. • The TL responses of the composites are proportional to the dose absorbed. • The CaSO4:Eu,Ag(NP) + glass has potential to be used as a thermoluminescent dosimeter

  14. Nanocomposite oxygen carriers for chemical-looping combustion of sulfur-contaminated synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Rahul D. Solunke; Goetz Veser [United States Department of Energy, Pittsburgh, PA (United States). National Energy Technology Laboratory

    2009-09-15

    Chemical-looping combustion (CLC) is an emerging technology for clean combustion. We have previously demonstrated that the embedding of metal nanoparticles into a nanostructured ceramic matrix can result in unusually active and sinter-resistant nanocomposite oxygen carrier materials for CLC, which combine the high reactivity of metals with the high-temperature stability of ceramics. In the present study, we investigate the effect of H{sub 2}S in a typical coal-derived syngas on the stability and redox kinetics of Ni- and Cu-based nanostructured oxygen carriers. Both carriers show excellent structural stability and only mildly changed redox kinetics upon exposure to H{sub 2}S, despite a significant degree of sulfide formation. Surprisingly, partial sulfidation of the support results in a strong increase in oxygen carrier capacity in both cases because of the addition of a sulfide-sulfate cycle. Overall, the carriers show great potential for use in CLC of high-sulfur fuels. 21 refs., 13 figs. 1 tab.

  15. Study of dimensional changes during redox cycling of oxygen carrier materials for chemical looping combustion

    NARCIS (Netherlands)

    Fossdal, A.; Darell, O.; Lambert, A.; Schols, E.; Comte, E.; Leenman, R.N.; Blom, R.

    2015-01-01

    Dimensional and phase changes of four candidate oxygen carrier materials for chemical looping combustion are investigated by dilatometry and high-temperature X-ray diffraction during four redox cycles. NiO/Ni2AlO4 does not exhibit significant dimensional changes during cycling, and it is shown that

  16. A Study on CaSO4 Fouling Deposit

    Institute of Scientific and Technical Information of China (English)

    RenXiaoguang; LiCuiqing; LiuChanghou

    2002-01-01

    This paper reports the influences of heat transfer surface properties on the formation of CaSO4 fouling deposition during flow boiling heat transfer.The surfaces of several test heaters have been treated by surface modification techniques.such as dynamic mixing ion beam implantation and dynamic mixing magnetron sputtering to reduce surface energy.Fouling runs with these heaters were carried out at different heat fluxes,flow velocities and salt concentrations.The results show that heat transfer surfaces with low surface energy experienced significantly a reduced formation of CaSO4 deposit.

  17. Large >60 gallon/day ‘pulse-tube’ oxygen liquefier for aircraft carriers

    Science.gov (United States)

    Spoor, P. S.

    2015-12-01

    An oxygen liquefier using a large ‘pulse-tube’ or acoustic-Stirling cryocooler is described, which has a liquefaction rate in excess of 60 gallons per day (227 liters per day) as measured by the increase in weight of a storage dewar, from <20 kWe input. Several of these systems will be deployed on U.S. Navy aircraft carriers to provide shipboard liquid oxygen. Paths to improvement in future systems are identified, although it is noted that since the present system exceeds the required specifications, these improvements may not be implemented in the near term.

  18. Calcium and chemical looping technology for power generation and carbon dioxide (CO2) capture solid oxygen- and CO2-carriers

    CERN Document Server

    Fennell, Paul

    2015-01-01

    Calcium and Chemical Looping Technology for Power Generation and Carbon Dioxide (CO2) Capture reviews the fundamental principles, systems, oxygen carriers, and carbon dioxide carriers relevant to chemical looping and combustion. Chapters review the market development, economics, and deployment of these systems, also providing detailed information on the variety of materials and processes that will help to shape the future of CO2 capture ready power plants. Reviews the fundamental principles, systems, oxygen carriers, and carbon dioxide carriers relevant to calcium and chemical loopingProvi

  19. Development of an ultrasound sensitive oxygen carrier for oxygen delivery to hypoxic tissue.

    Science.gov (United States)

    Eisenbrey, John R; Albala, Lorenzo; Kramer, Michael R; Daroshefski, Nick; Brown, David; Liu, Ji-Bin; Stanczak, Maria; O'Kane, Patrick; Forsberg, Flemming; Wheatley, Margaret A

    2015-01-15

    Radiation therapy is frequently used in the treatment of malignancies, but tumors are often more resistant than the surrounding normal tissue to radiation effects, because the tumor microenvironment is hypoxic. This manuscript details the fabrication and characterization of an ultrasound-sensitive, injectable oxygen microbubble platform (SE61O2) for overcoming tumor hypoxia. SE61O2 was fabricated by first sonicating a mixture of Span 60 and water-soluble vitamin E purged with perfluorocarbon gas. SE61O2 microbubbles were separated from the foam by flotation, then freeze dried under vacuum to remove all perfluorocarbon, and reconstituted with oxygen. Visually, SE61O2 microbubbles were smooth, spherical, with an average diameter of 3.1 μm and were reconstituted to a concentration of 6.5 E7 microbubbles/ml. Oxygen-filled SE61O2 provides 16.9 ± 1.0 dB of enhancement at a dose of 880 μl/l (5.7 E7 microbubbles/l) with a half-life under insonation of approximately 15 min. In in vitro release experiments, 2 ml of SE61O2 (1.3 E8 microbubbles) triggered with ultrasound was found to elevate oxygen partial pressures of 100ml of degassed saline 13.8 mmHg more than untriggered bubbles and 20.6 mmHg more than ultrasound triggered nitrogen-filled bubbles. In preliminary in vivo delivery experiments, triggered SE61O2 resulted in a 30.4 mmHg and 27.4 mmHg increase in oxygen partial pressures in two breast tumor mouse xenografts. PMID:25448552

  20. Significance of oxygen carriers and role of liquid paraffin in improving validamycin A production.

    Science.gov (United States)

    Feng, Jinsong; Jiang, Jing; Liu, Yan; Li, Wei; Azat, Ramila; Zheng, Xiaodong; Zhou, Wen-Wen

    2016-10-01

    Validamycin A (Val-A) synthesized by Streptomyces hygroscopicus 5008 is widely used as a high-efficient antibiotic to protect plants from sheath blight disease. A novel fermentation strategy was introduced to stimulate Val-A production by adding oxygen carriers. About 58 % increase in Val-A production was achieved using liquid paraffin. Further, biomass, carbon source, metabolic genes, and metabolic enzymes were studied. It was also found that the supplementation of liquid paraffin increased the medium dissolved oxygen and intracellular oxidative stress level. The expression of the global regulators afsR and soxR sensitive to ROS, ugp catalyzing synthesis of Val-A precursor, and Val-A structural genes was enhanced. The change of the activities of glucose-6-phosphate dehydrogenase and glyceraldehyde 3-phosphate dehydrogenase was observed, which reflected the redirection of carbon metabolic flux. Based on these results, liquid paraffin addition as an oxygen carrier could be a useful technique in industrial production of Val-A and our study revealed a redox-based secondary metabolic regulation in S. hygroscopicus 5008, which provided a new insight into the regulation of the biosynthesis of secondary metabolites.

  1. On the luminescence properties of CaSO4:Ce.

    Science.gov (United States)

    Lapraz, D; Prevost, H; Iacconi, P; Guigues, C; Benabdesselam, M; Briand, D

    2002-01-01

    The luminescent properties of cerium doped calcium sulphate are studied: fluorescence and excitation spectra, optical absorption and thermoluminescence (TSL). It is known that, in rare earth doped CaSO4, only cerium induces a strong 400 degrees C TSL peak. In CaSO4:0.2%Ce samples synthesised under oxidising conditions, the recovery step of Ce3+ fluorescence is correlated with the 400 degrees C TSL peak readout, as mentioned by Nair er al. Our results indicate that an oxidation of Ce3+ ion does occur under X-irradiation (Ce3+ --> Ce4+), followed by a complete return to the trivalent state after thermal annealing at about 500 degrees C; our results confirm the hypothesis of Nair et al that Ce3+ ions are oxidised by ionising irradiation. So, a pure redox reaction seems the most probable for the 400 degrees C TSL peak of CaSO4:Ce. Moreover, the use of the 400 degrees C TSL peak for high temperature dosimetry applications is discussed.

  2. Physical properties of hemoglobin-poly(acrylamide) hydrogel-based oxygen carriers: effect of reaction pH.

    Science.gov (United States)

    Patton, Jaqunda N; Palmer, Andre F

    2006-02-28

    This work examines the physical properties of bovine hemoglobin (BHb) chemically cross-linked to a pH responsive polymer (poly(acrylamide)) with the goal of taking advantage of the polymer's pH sensitivity to generate low-P50 oxygen carriers for application in physiological conditions characterized by deviations from normal pH. BHb-hydrogel-based oxygen carriers encapsulating 10-16 g/dL BHb displayed P50s liposomes (i.e. Hb-LGs) and change conformations between the R and T states. The magnitude of the zeta potential of Hb-LGs and Hb-NHPs was shown to be within the range of stored red blood cells and within the range of limited flocculation. Taken together, this work describes the preparation and characterization of oxygen carriers with increased oxygen affinities compared to those of red blood cells. PMID:16489809

  3. Artificial Oxygen Carriers%人工氧载体研究进展

    Institute of Scientific and Technical Information of China (English)

    殷晓春; 王荣民; 何玉凤; 朱永峰; 裴菲

    2011-01-01

    Because of the increasing demand for blood and the emergence of unsafe issues in allogeneic blood transfusion, blood substitutes are attracting increasing interest in chemistry and medical science.Based on the knowledge of the structure and functions of hemoglobin-a typical natural oxygen carrier, many artificial oxygen carriers have been synthesized and applied to clinical trails.Artificial oxygen carriers include perfluorocarbon,hemoglobin-based oxygen carrier, synthetic heme and its polymer metal complexes.Although most of the perfluorocarbons could not be applied as blood substitutes, their applications as medicine are still continued because of their therapeutic effect.In order to reduce unwanted side-effects of hemoglobin-based oxygen carriers,hemoglobin has been modified by many methods, such as chemical modification, microencapsulation, recombinant technology, biomimetic nanotechnology, etc.Among all of the above hemoglobin-based oxygen carriers, the particle size of hemoglobin vesicles ( HbV ) is relatively larger in the simulation of the structure of the red blood cell.It represents one of the tendency of the progress of hemoglobin-based oxygen carriers.Most of synthetic hemes, such as pocket porphyrin metal complexes, are only dissolved in organic solvents.In order to increase their water-solubility, synthetic hemes have been conjugated with albumin, xylitol enzymes and cyclodextrin and so on.The results of animal trial showed that these polymer metal complexes could transport dioxygen in the animal body.Beside to be used as the blood substitutes in clinical trails, artificial oxygen carriers have other potential clinical uses, such as cancer therapy, organ transplantation and prevention of ischemia/reperfusion injury of tissues and organs.%血液需求的激增和异体输血的不安全性等问题的出现,促使人们合成"血液替代品".通过对天然氧载体(即血红蛋白)结构与性能的清晰认识,已有多种人工氧载体被成功

  4. High dose and phototransferred thermoluminescence in CaSO4, CaSO4:Dy, and CaSO4:Tm

    International Nuclear Information System (INIS)

    An investigation is presented to test the feasibility of extending the usefulness of the CaSO4 phosphor doped with Tm or Dy into the high dose/high temperature regime. The doses studied range from 1 kGy to 100 kGy obtained from γ ray and flash electron beam sources. Integrated glow curve signals in the 'dosimetry range' (∼100-350oC) and the high temperature range (∼350-600oC) are measured as a function of dose. Integrated UV phototransferred thermoluminescence signals (∼100-300oC) are similarly considered. For powdered samples doped to 0.1 mol%, the onset of saturation occurs near 10 kGy. This establishes that thermoluminescence doseimetry for industrial food processing (pasteurisation, disinfestation, radicidation and radurisation) is a possibility.( (author)

  5. Effect of oxygen precipitates in solar grade silicon on minority carrier lifetime and efficiency of solar cells

    Institute of Scientific and Technical Information of China (English)

    SUN Haizhi; LIU Caichi; HAO Qiuyan; WANG Lijian

    2006-01-01

    The effect of oxygen precipitates on minority carrier lifetime and performance of solar cell was studied by means of Fourier Transform Infrared Spectroscopy (FTIR), quasi-steady state photoconductance (QSSPCD), optical microscope, spectrumresponse and solar cell efficiency test. The minority carrier lifetime and performance of solar cell reduced depend on oxygen precipitates. A few of oxygen precipitates have formed after single-step annealing; and they do not impact the efficiency dramatically. Pre-annealing at 650 ℃ for 4 h enhances the oxygen precipitation when it is subjected to middle temperature annealing. The solar cells performance decayed sharply. Especially annealing at 950 ℃ for 3 h, the V os and I sc of cells decrease 12% and 25% respectively. Few oxygen precipitates have formed in silicon after high temperature annealing at about 1050 ℃ whether pre-annealing is used or not, and the performance of cells is notbe affected.

  6. Performance of coal fly-ash based oxygen carrier for the chemical looping combustion of synthesis gas

    International Nuclear Information System (INIS)

    Highlights: • Fly-ash based oxygen carriers were synthesised for chemical looping combustion of synthesis gas. • Using fly-ash as the support of the oxygen carrier enhanced the thermal stability and oxidant transfer for fuel oxidation. • Fly-ash based nickel oxide reformed hydrocarbons into carbon monoxide with the presence of carbon dioxide. - Abstract: The performance of coal fly-ash based oxygen carriers for chemical looping combustion of synthesis gas has been investigated using both a thermogravimetric analyser and a packed bed reactor. Oxygen carriers with 50 wt% active metal compounds, including copper, nickel and iron oxides, supported on coal fly-ash were synthesised using the deposition–precipitation method. Copper oxide and nickel oxide supported on fly-ash showed high oxygen transfer efficiency and oxygen carrying capacity at 800 °C. The fly-ash based nickel oxide was effective in reforming hydrocarbons and for the conversion of carbon dioxide into carbon monoxide; a nickel complex with silicate was identified as a minor phase following the reduction reaction. The fly-ash based iron oxide showed various reduction steps and resulted in an extended reduction time. The carbon emission at the oxidation stage was avoided by reducing the length of the exposure to the reduction gas

  7. [Effects of Hydraulic Retention Time and Dissolved Oxygen on a CANON Reactor with Haydite as Carrier].

    Science.gov (United States)

    Wang, Hui-fang; Fu, Kun-ming; Zuo, Zao-rong; Qiu, Fu-guo

    2015-11-01

    One Completely Autotrophic Nitrogen Removal Over Nitrite ( CANON) reactor with haydite as carrier was investigated to study the effects of different hydraulic retention time ( HRT) and dissolved oxygen (DO) on CANON reactors by seeding sludge from another mature CANON reactor and using synthetic inorganic ammonia-rich waste water as influent. During the experiment, the concentration of influent ammonia nitrogen was basically unchanged, the HRT of the reactor were 9, 7, 5 h in turn and the range of DO was 1.16-3.20 mg x L(-1). The results showed that: (1) When DO was 1.20-1.75 mg x L(-1), despite the increase of DO can improve AOB's activity and matrix mass transfer in the system, NH4(+) -N and TN removal efficiency were still fell with the shortening of HRT for the CANON reactor, especially when DO was higher than 2.50 mg x L(-1), TN removal efficiency dropped sharply; (2) Under the condition that DO was 1.20-1.75 mg x L(-1), with the shortening of HRT, partial nitritation tended to be stable in the CANON process, and when DO was higher than 1.75 mg x L(-1), even if HRT was shorter, partial nitritation was still severely damaged; (3) Under the condition that DO was 1.20-1.75 mg x L(-1) and HRT was 7 h, for the CANON reactor, partial nitritation and total nitrogen removal efficiency kept well. Hydraulic retention time and dissolved oxygen both are important operational parameters for biological wastewater treatment process, which could directly affect the effect of biological treatment and effluent quality, so to choose appropriate hydraulic retention time and dissolved oxygen coordinately is very important to improve the effect of treatment of ammonium-rich wastewater by CANON process. PMID:26911004

  8. Application of Fe2O3/Al2O3 Composite Particles as Oxygen Carrier of Chemical Looping Combustion

    Institute of Scientific and Technical Information of China (English)

    Fang He; Hua Wang; Yongnian Dai

    2007-01-01

    Chemical looping combustion (CLC) of carbonaceous compounds has been proposed, in the past decade, as an efficient method for CO2 capture without cost of extra energy penalties. The technique involves the use of a metal oxide as an oxygen carrier that transfers oxygen from combustion air to fuels.The combustion is carried out in a two-step process: in the fuel reactor, the fuel is oxidized by a metal oxide, and in the air reactor, the reduced metal is oxidized back to the original phase. The use of iron oxide as an oxygen carrier has been investigated in this article. Particles composed of 80 wt% Fe2O3,together with Al2O3 as binder, have been prepared by impregnation methods. X-ray diffraction (XRD) analysis reveals that Fe2O3 does not interact with the Al2O3 binder after multi-cycles. The reactivity of the oxygen carrier particles has been studied in twenty-cycle reduction-oxidation tests in a thermal gravimetrical analysis (TGA) reactor. The components in the outlet gas have been analyzed. It has been observed that about 85% of CH4 converted to CO2 and H2O during most of the reduction periods. The oxygen carrier has kept quite a high reactivity in the twenty-cycle reactions. In the first twenty reaction cycles, the reaction rates became slightly higher with the number of cyclic reactions increasing, which was confirmed by the scanning electron microscopy (SEM) test results. The SEM analysis revealed that the pore size inside the particle had been enlarged by the thermal stress during the reaction, which was favorable for diffusion of the gaseous reactants into the particles. The experimental results suggested that the Fe2O3/Al2O3 oxygen carrier was a promising candidate for a CLC system.

  9. Atomistic modelling of the hydration of CaSO 4

    Science.gov (United States)

    Adam, Craig D.

    2003-08-01

    Atomistic modelling techniques, using empirical potentials, have been used to simulate a range of structures formed by the hydration of γ-CaSO 4 and described as CaSO 4· nH 2O (0commercial importance and has been subjected to much experimental study. These simulation studies demonstrate significant water-matrix interactions that influence the crystallography of the hydrated phase. The existence of two types of hydration site has been predicted, including one within the Ca 2+coordination sphere. Close correlation between water molecule bonding energy, Ca 2+-O w bond length and unit-cell volume have been established. This shows that as the number of water molecules within the unit cell increases, the bonding energy increases and the unit cell contracts. However around n=0.5, this process reaches a turning point with the incorporation of further waters resulting in reduced binding energy and an expanding unit cell.

  10. Influence of oxygen addition to the carrier gas on laser-induced breakdown spectroscopy measurements on aerosols

    Science.gov (United States)

    Palazzo, N.; Migliorini, F.; Dondè, R.; Maffi, S.; De Iuliis, S.

    2016-01-01

    In this work, laser-induced breakdown spectrosopy is implemented on aerosol particles for absolute concentration analysis. The aim of this work is the investigation of the effect of the bath gas used for nebulizing the aerosol. Nitrogen, air, and 50% O2 in N2 mixture have been chosen as carrier gasses in order to analyze the effect of oxygen addition to the gas. LIBS measurements have been carried out on aerosol particles produced from CuCl2 2H2O solutions, and the 324.7 nm Cu line is considered. As a first analysis, plasma parameters, such as temperature and electron density, have been evaluated changing the carrier gas. Measurements to derive the LIBS calibration curve of the 324.7 nm Cu line are carried out in air and in N2. The significant difference in the slope of the resulting calibration curves has to be attributed to the oxygen addition to the bath gas. To explore such behavior, time-resolved measurements of the Cu line and peak/base ratio have been performed. The presence of two competitive effects have been observed that becomes significant increasing the amount of oxygen in the carrier gas. One is the oxygen-quenching effect, already observed in the literature, and the other one is the enhancement of the Cu LIBS signal, expecially at short delay times. These effects have been observed also at other Cu lines and changing the analyte source. The results are presented and widely discussed.

  11. Examination of Perovskite Structure CaMnO3-δ with MgO Addition as Oxygen Carrier for Chemical Looping with Oxygen Uncoupling Using Methane and Syngas

    Directory of Open Access Journals (Sweden)

    Dazheng Jing

    2013-01-01

    Full Text Available Perovskite structure oxygen carriers with the general formula CaMnxMg1-xO3-δ were spray-dried and examined in a batch fluidized bed reactor. The CLOU behavior, reactivity towards methane, and syngas were investigated at temperature 900°C to 1050°C. All particles showed CLOU behavior at these temperatures. For experiments with methane, a bed mass corresponding to 57 kg/MW was used in the reactor, and the average CH4 to CO2 conversion was above 97% for most materials. Full syngas conversion was achieved for all materials utilizing a bed mass corresponding to 178 kg/MW. SEM/EDX and XRD confirmed the presence of MgO in the fresh and used samples, indicating that the Mg cation is not incorporated into the perovskite structure and the active compound is likely pure CaMnO3-δ. The very high reactivity with fuel gases, comparable to that of baseline oxygen carriers of NiO, makes these perovskite particles highly interesting for commercial CLC application. Contrary to NiO, oxygen carriers based on CaMnO3-δ have no thermodynamic limitations for methane oxidation to CO2 and H2O, not to mention that the materials are environmentally friendly and can utilize much cheaper raw materials for production. The physical properties, crystalline phases, and morphology information were also determined in this work.

  12. Energy response of CaSO4:Dy teflon TLD disk dosimeters to photons and electrons.

    Science.gov (United States)

    Sharada, K S

    1983-01-01

    The photon energy response of CaSO4:Dy teflon disk dosimeters used widely in radiation dosimetry is computed using the energy absorption coefficient values for calcium, sulfur, oxygen, and carbon taken from J. H. Hubbell's tables. For fluorine, the energy absorption coefficients were obtained from the values given by F. H. Attix for CaF2 and Ca. The energy response of the radiation-monitoring disk for the range of 10 keV to 10 MeV, relative to air, is computed and plotted. The response is maximum between 20 and 30 keV and then gradually falls to a constant at 200 keV to 10 MeV. This computed response for different energies is compared with the experimental TL response of the dosimeter. The electron energy response of these TLD disks is computed using the stopping-power values for the different component elements. The electron stopping power for sulfur and calcium from 10 keV to 10 MeV is computed using the Bethe-Bloch formula. Those for oxygen and carbon are taken from the tables given by M. J. Berger and S. M. Seltzer. For fluorine, the values are computed from those for Li and LiF given in the same tables. This calculated response is compared with the experimental beta response of the TL dosimeter. PMID:6823508

  13. Synthesis of Hemoglobin Conjugated Polymeric Micelle: A ZnPc Carrier with Oxygen Self-Compensating Ability for Photodynamic Therapy.

    Science.gov (United States)

    Wang, Shasha; Yuan, Fang; Chen, Kui; Chen, Gaojian; Tu, Kehua; Wang, Hongjun; Wang, Li-Qun

    2015-09-14

    Photodynamic therapy (PDT) is a promising singlet oxygen ((1)O2) mediated clinical treatment for many tumors. As the source of (1)O2, oxygen plays an important role in the curative effect of PDT. However, the facts of photochemical depletion of oxygen and the intrinsic hypoxic microenvironment of tumors remain the major challenges. In this work, a novel photosensitizer carrier with oxygen self-compensating ability was designed for PDT. It was synthesized via chemical conjugation of hemoglobin (Hb) to polymeric micelles formed by triblock copolymers of poly(ethylene glycol)-block-poly(acrylic acid)-block-polystyrene (PEG-b-PAA-b-PS). The PEG-b-PAA-b-PS and resultant micelles in aqueous solution were comprehensively characterized by means of FTIR, (1)H NMR, GPC, DLS, TEM, and fluorescence spectroscopy. The oxygen-binding capacity and antioxidative activity of the Hb conjugated micelles were evaluated via UV-vis spectroscopy. In addition, compared with the control micelles without Hb, the Hb conjugated photosensitizer carrier was able to generate more (1)O2 and exert greater photocytotoxicity on Hela cells in vitro.

  14. A review of blood substitutes: examining the history, clinical trial results, and ethics of hemoglobin-based oxygen carriers

    OpenAIRE

    Jiin-Yu Chen; Michelle Scerbo; George Kramer

    2009-01-01

    The complications associated with acquiring and storing whole blood for transfusions have launched substantial efforts to develop a blood substitute. The history of these efforts involves a complicated mixture of science, ethics, and business. This review focuses on clinical trials of the three hemoglobin-based oxygen carriers (HBOC) that have progressed to Phase II or III clinical trials: He-mAssist (Baxter; Deerfield, IL, US), PolyHeme (Northfield; Evanston, IL, US), and Hemopure (Biopure; ...

  15. Evaluation of the capabilities of a hemoglobin vesicle as an artificial oxygen carrier in a rat exchange transfusion model.

    Science.gov (United States)

    Izumi, Y; Sakai, H; Kose, T; Hamada, K; Takeoka, S; Yoshizu, A; Horinouchi, H; Kato, R; Nishide, H; Tsuchida, E; Kobayashi, K

    1997-01-01

    Encapsulation of hemoglobin within a liposome is one of the strategies in the development of artificial oxygen carriers. It maintains the oxygen transporting properties of hemoglobin and, at the same time, eliminates the side effects of cell free hemoglobin. Hemoglobin vesicles (HbV) are a type of liposome encapsulated hemoglobin. They have a particle size of approximately 250 nm, a hemoglobin concentration of 10 g/dl, and the oxygen affinity, P50, is regulated to 32 Torr. In this study the authors examined the oxygen transporting capability of HbV in vivo, by performing exchange transfusions in rats. Exchange transfusion (90% of the estimated circulatory volume) with HbV suspended in 5% albumin (containing 160 mEq/L, sodium and 107 mEq/L, chloride) was carried out in male Wistar rats. Mean arterial pressure and heart rate were monitored through the arterial catheter. Arterial blood samples for gas analyses were also obtained from the arterial catheter. Abdominal aortic blood flow was measured by an ultrasonic pulsed Doppler flowmeter as an indicator of cardiac output. The oxygen tension of blood withdrawn from the right atrium was measured as an indicator of mixed venous oxygen tension. These values were employed to calculate oxygen delivery and consumption. Renal cortical and skeletal muscle tissue oxygen tensions were monitored as indicators of tissue perfusion. Five percent albumin and washed rat red blood cells suspended in 5% albumin containing 10 g/dl of hemoglobin; were employed as controls. At the completion of a 90% exchange transfusion, renal cortical and skeletal muscle tissue oxygen tensions, along with oxygen delivery and consumption, were sustained almost equally well with the HbV suspension compared to the washed rat red blood cell suspension, but declined significantly with the albumin suspension. The results indicate that the oxygen transporting capability of HbV was almost equivalent to that of rat red blood cells. PMID:9242942

  16. Investigation of temperature-dependent asymmetric degradation behavior induced by hot carrier effect in oxygen ambiance in In–Ga–Zn-O thin film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bo-Wei [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Chang, Ting-Chang [Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Advanced Optoelectronics Technology Center, National Cheng Kung University, Taiwan (China); Hung, Yu-Ju [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Hsieh, Tien-Yu [Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Tsai, Ming-Yen [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Liao, Po-Yung [Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Tsai, Wu-Wei; Chiang, Wen-Jen; Yan, Jing-Yi [Industrial Technology Research Institute, 195, Sec. 4, Chung Hsing Rd., Hsinchu, 31040, Taiwan (China)

    2014-12-01

    The effects of oxygen ambiance on electrical characteristic degradation phenomena in a-InGaZnO thin film transistor with different biases and temperatures are investigated. It can be found that oxygen is substantially adsorbed on the backchannel and results in device instabilities during positive gate bias stress. However, visible light irradiation is found to desorb the adsorbed oxygen ions and this verifies that oxygen dominates the degradation behavior. Moreover, comparing with that in vacuum, hot-carrier stress in oxygen ambiance leads to an extra potential barrier height near the drain side due to oxygen adsorption and causes asymmetric degradation. Furthermore, the asymmetric degradation behavior after hot-carrier stress in oxygen ambiance is suppressed at high temperature due to temperature-induced oxygen desorption or heat-induced holes injecting into the gate insulator. - Highlights: • Oxygen adsorbing will occur beneath the active layer under persistent positive gate bias. • Oxygen desorbing under illumination was verified from the recovery of transfer curves. • Additional barrier height is generated after hot-carrier stress because of oxygen adsorption. • The amount of hot-carrier degradation in oxygen ambience will decrease as temperature elevating.

  17. Performance of Ni-based, Fe-based and Co-based Oxygen Carriers in Chemical-Looping Hydrogen Generation

    Institute of Scientific and Technical Information of China (English)

    Liang Hao; Zhang Xiwen; Fang Xiangchen; Yuan Honggang

    2013-01-01

    Ni-based, Fe-based and Co-based oxygen carriers with perovskite oxides used as the supports were prepared by citric acid complexation method. The oxygen carriers were characterized by thermal analysis, H2-temperature-programmed reduction and X-ray diffraction methods. Performance tests were evaluated through Chemical-Looping Hydrogen Genera-tion in a ifxed-bed reactor operating at atmospheric pressure. The characterization results showed that all samples were composed of metal oxides and perovskite oxides. Performance results indicated that CH4 conversion over the oxygen car-riers decreased in the following order:NiO/LaNiO3>Co2O3/LaCoO3>Fe2O3/LaFeO3. The ability of NiO/LaNiO3 and Fe2O3/LaFeO3 to decompose water was stronger than that of Co2O3/LaCoO3 as evidenced by our experiments. H2 amounting to 80 mL upon reacting on methane in every cycle could be completely oxidized by NiO/LaNiO3 at 900℃in the period from the third cycle to the eighth cycle.

  18. Development of Li compound embedded with CaSO4:Dy TL pellet for neutron measurement

    International Nuclear Information System (INIS)

    Personal neutron dosimetry is quite a difficult area because a neutron is always accompanied with gamma radiation, which is required of a the capability for mixed field dosimetry. CaSO4: Dy phosphor is known to have a very high sensitivity to gamma, but the neutron capture cross section of the constituents of CaSO4:Dy are so small that the interactions between the thermal neutron and the phosphor are rare. One method to improve the neutron interaction is by introducing an impurity ion with a large thermal neutron captures cross section into the phosphor to act as a neutron target centre such as 6Li. In neutron-gamma mixed radiation fields, if two detectors for the 6Li-7Li compounds embedded CaSO4:Dy TL pellets are used, a 6Li-compound embedded pellet can detect the neutron and gamma radiation together, and the other pellet can only detect the gamma radiation. Recently Korea Atomic Energy Research Institute (KEARI) has developed a new type of CaSO4:Dy TL materials embedded with phosphorous (KCT-300) to detect beta and gamma radiation with a very high sensitivity. This paper presents the development of CaSO4:Dy TL pellets embedded with 6Li compound for a thermal neutron measurement, and the detection method of the neutron and gamma dose in mixed fields with CaSO4:Dy TL pellets embedded with a 6Li compound(KCT-306) and CaSO4:Dy TL pellets embedded with a 7Li compound(KCT-307) is introduced. The net neutron sensitivity of CaSO4:Dy TL pellets embedded with 6Li compound developed in this study is about 2 times higher than that of the TLD-600 (Harshaw Co.) dosimeter which is available in the open market

  19. Feasibility study of CaSO4:Tb,Yb as a thermoluminescent dosimeter

    International Nuclear Information System (INIS)

    A new composite based on CaSO4, using terbium as dopant and ytterbium as co-dopant (CaSO4:Tb,Yb), was developed for employment as a thermoluminescent (TL) dosimeter. The crystals used in this work were grown using a production route based on the Yamashita method (Yamashita et al., 1968). Crystal powder was calcined at 600 °C for 1 h. Pellets were made by adding commercial and colorless glass to improve physical resistance and sintered at 700 °C for 6 h. All samples were irradiated by a beta source (90Sr/90Y) and received doses from 1 Gy to 5 Gy. TL analyses have been performed and characteristics such as sensitivity, reproducibility, linearity, and fading have been studied. The CaSO4:Tb,Yb pellets glow curves presented two peaks, the first at around 115 °C, and the second at around 200 °C. The highest intensity was shown for CaSO4:Tb,Yb with a concentration of 0.1 mol% of Tb and Yb together. In all the samples the TL response was proportional to the absorbed dose. Therefore, the CaSO4:Tb,Yb has potential to be used as a thermoluminescent dosimeter. - Highlights: ► A new dosimeter based on CaSO4 and doped with Tb and Yb is proposed. ► The samples were grown using a production route based in the Yamashita method. ► CaSO4:Tb,Yb glow curves exhibited a TL emission in temperatures from 100 to 270 °C. ► The TL responses of the composites produced are proportional to the dose absorbed. ► The CaSO4:Tb,Yb has potential to be used as a thermoluminescent dosimeter

  20. The calcium phosphate coating of soy lecithin nanoemulsion with performance in stability and as an oxygen carrier

    Science.gov (United States)

    Han, Kyu B.

    This work studied the relationship between surfactant, oil, and water, by building ternary phase diagrams, the goal of which was to identify the oil-in-water phase composition. The resulting nano-sized emulsion was coated with dicalcium phosphate by utilizing the ionic affinity between calcium ions and the emulsion surface. Since the desired function of the particle is as an oxygen carrier, the particle stability, oxygen capacity, and oxygen release rate were investigated. The first step in the process was to construct ternary phase diagrams with 1,2-dioleoyl-sn-glycero-3-phosphate (DOPA) and soy derived lecithin. The results showed that the lecithin surfactant formed an oil-in-water phase region that was 36 times greater than that of DOPA. With the desired phase composition set, the lecithin emulsion was extruded, resulting in a well-dispersed nanosized particle. A pH titration study of the emulsion found an optimized calcium phosphate coating condition at pH 8.8, at which, the calcium ion had a greater affinity for the emulsion surface than phosphate. A Hill plot was used to show calcium cooperativeness on the emulsion surface which suggested one calcium ion binds to one lecithin molecule. The lecithin emulsion particles were then coated with calcium phosphate using a layering technique that allowed for careful control of the coating thickness. The overall particle hydrodynamic radius was consistent with the growth of the calcium phosphate coating, from 8 nm to 28 nm. This observation was further supported with cryo-TEM measurements. The stability of the coated emulsion was tested in conditions that simulate practical thermal, physical, and time-dependent conditions. Throughout the tests, the coated emulsion exhibited a constant mono-dispersed particle size, while the uncoated emulsion size fluctuated greatly and exhibited increased polydispersion. The fast mixing method with the stopped-flow apparatus was employed to test the product as an oxygen carrier, and it

  1. Fluorinert, an oxygen carrier, improves cell culture performance in deep square 96-well plates by facilitating oxygen transfer.

    Science.gov (United States)

    Meyer, Aaron; Condon, Russell G G; Keil, Gregory; Jhaveri, Nikita; Liu, Zhong; Tsao, Yung-Shyeng

    2012-01-01

    In bioprocess development, the 96-well plate format has been widely used for high-throughput screening of production cell line or culture conditions. However, suspension cell cultures in conventional 96-well plates often fail to reach high cell density under normal agitation presumably due to constraints in oxygen transfer. Although more vigorous agitation can improve gas transfer in 96-well plate format, it often requires specialized instruments. In this report, we employed Fluorinert, a biologically inert perfluorocarbon, to improve oxygen transfer in 96-well plate and to enable the growth of a Chinese Hamster Ovary cell line expressing a recombinant monoclonal antibody. When different amounts of Fluorinert were added to the cell culture medium, a dose-dependent improvement in cell growth was observed in both conventional and deep square 96-well plates. When sufficient Fluorinert was present in the culture, the cell growth rate, the peak cell density, and recombinant protein production levels achieved in deep square 96-wells were comparable to cultures in ventilated shake flasks. Although Fluorinert is known to dissolve gases such as oxygen and CO(2), it does not dissolve nor extract medium components, such as glucose, lactate, or amino acids. We conclude that mixing Fluorinert with culture media is a suitable model for miniaturization of cell line development and process optimization. Proper cell growth and cellular productivity can be obtained with a standard shaker without the need for any additional aeration or vigorous agitation. PMID:21954223

  2. Preparation, characterization and in vivo investigation of blood-compatible hemoglobin-loaded nanoparticles as oxygen carriers.

    Science.gov (United States)

    Lu, Mingzi; Zhao, Caiyan; Wang, Quan; You, Guoxing; Wang, Ying; Deng, Hongzhang; Chen, Gan; Xia, Sha; Zhao, Jingxiang; Wang, Bo; Li, Xianlei; Shao, Leihou; Wu, Yan; Zhao, Lian; Zhou, Hong

    2016-03-01

    Although many attempts have been made to design advanced hemoglobin-based oxygen carriers (HBOCs), no clinically viable product has been widely approved, because they do not perform normal blood functions, such as coagulation, hematologic reactions and stability. Additionally, the in vivo oxygenation of hemoglobin-loaded nanoparticles (HbPs) encapsulated with polymers has seldom been proved. Herein, HbPs of approximately 200nm with good stability were successfully fabricated and exhibited oxygen-carrying capacity. The HbPs preserve the biological and structure features of hemoglobin according to UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy and circular dichroism (CD) spectral analysis. In vitro, the HbPs showed a viscosity comparable to that of blood with no obvious effects on red blood cell aggregation. At the same time, blood compatibility was characterized in terms of platelet function, clot strength, speed of clot formation, degree of fibrin cross-linking and hemolysis rate. After intravenous administration of HbPs to mice with controlled hemorrhages, blood flow recovery and maintenance of systemic oxygenation were observed.

  3. Screening of NiFe2O4 Nanoparticles as Oxygen Carrier in Chemical Looping Hydrogen Production

    DEFF Research Database (Denmark)

    Liu, Shuai; He, Fang; Huang, Zhen;

    2016-01-01

    ) porosity test. The performance of the prepared materials was first evaluated in a TGA reactor through a CO reduction and subsequent steam oxidation process. Then a complete redox process was conducted in a fixed-bed reactor, where the NiFe2O4 oxygen carrier was first reduced by simulated biomass pyrolysis...... gas (24% H2 + 24% CO + 12% CO2 + N2 balance), then reacted with steam to produce H2, and finally fully oxidized by air. The NiFe2O4 oxygen carrier prepared by the sol gel method showed the best capacity for hydrogen production and the highest recovery degree of lattice oxygen, in agreement with the......The objective of this paper is to systematically investigate the influences of different preparation methods on the properties of NiFe2O4 nanoparticles as oxygen carrier in chemical looping hydrogen production (CLH). The solid state (SS), coprecipitation (CP), hydrothermal (HT), and sol-gel (SG...

  4. CaSO4 and cationic polyelectrolyte as possible pectin precipitants in sugar beet juice clarification

    Directory of Open Access Journals (Sweden)

    Kuljanin Tatjana

    2015-01-01

    Full Text Available Three pectin preparations were isolated from fresh sugar beet pulp during the 150 minutes of extraction, at pH values of 1, 3.5 and 8.5. CaSO4 precipitant was added to 100 cm3 of 0.1% (wt solution of pectin. Studies were performed with 9 different concentrations of CaSO4 solution (50-450 mg dm-3 with the addition of a cationic polyelectrolyte (cationic PAM in concentrations of 3 and 5 mg dm-3. The efficiency of pectin precipitation was monitored by measuring the zeta potential of pectin preparations. Optimal amounts of precipitant CaSO4, without the use of a cationic polyelectrolyte, were as follows: 490-678 mg CaSO4/g pectin. After the use of a cationic polyelectrolyte, the optimal amounts of CaSO4 were smaller (353-512 mg/g pectin. These quantities are significantly lower than the average amount of CaO used in the conventional clarification process of sugar beet juice (about 9 g/g pectin of sugar beet juice. [Projekat Ministarstva nauke Republike Srbije, br. TR -31055

  5. Chemical-looping gasification of biomass in a 10k Wth interconnected fluidized bed reactor using Fe2 O3/Al2 O3 oxygen carrier

    Institute of Scientific and Technical Information of China (English)

    HUSEYIN Sozen; WEI Guo-qiang; LI Hai-bin; HE Fang; HUANG Zhen

    2014-01-01

    The aim of this research is to design and operate a 10 kW hot chemical-looping gasification ( CLG) unit using Fe2 O3/Al2 O3 as an oxygen carrier and saw dust as a fuel. The effect of the operation temperature on gas composition in the air reactor and the fuel reactor, and the carbon conversion of biomass to CO2 and CO in the fuel reactor have been experimentally studied. A total 60 h run has been obtained with the same batch of oxygen carrier of iron oxide supported with alumina. The results show that CO and H2 concentrations are increased with increasing temperature in the fuel reactor. It is also found that with increasing fuel reactor temperature, both the amount of residual char in the fuel reactor and CO2 concentration of the exit gas from the air reactor are degreased. Carbon conversion rate and gasification efficiency are increased by increasing temperature and H2 production at 870 ℃reaches the highest rate. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and BET-surface area tests have been used to characterize fresh and reacted oxygen carrier particles. The results display that the oxygen carrier activity is not declined and the specific surface area of the oxygen carrier particles is not decreased significantly.

  6. Experimental Investigation of CaMnO3−δ Based Oxygen Carriers Used in Continuous Chemical-Looping Combustion

    Directory of Open Access Journals (Sweden)

    Peter Hallberg

    2014-01-01

    Full Text Available Three materials of perovskite structure, CaMn1−xMxO3−δ (M = Mg or Mg and Ti, have been examined as oxygen carriers in continuous operation of chemical-looping combustion (CLC in a circulating fluidized bed system with the designed fuel power 300 W. Natural gas was used as fuel. All three materials were capable of completely converting the fuel to carbon dioxide and water at 900°C. All materials also showed the ability to release gas phase oxygen when fluidized by inert gas at elevated temperature (700–950°C; that is, they were suitable for chemical looping with oxygen uncoupling (CLOU. Both fuel conversion and oxygen release improved with temperature. All three materials also showed good mechanical integrity, as the fraction of fines collected during experiments was small. These results indicate that the materials are promising oxygen carriers for chemical-looping combustion.

  7. Hydrogen and syngas production from two-step steam reforming of methane using CeO2 as oxygen carrier

    Institute of Scientific and Technical Information of China (English)

    Xing Zhu; Hua Wang; Yonggang Wei; Kongzhai Li; Xianming Cheng

    2011-01-01

    CeO2 oxygen carrier was prepared by precipitation method and tested by two-step steam reforming of methane (SRM).Two-step SRM for hydrogen and syngas generation is investigated in a fixed-bed reactor.Methane is directly converted to syngas at a H2/CO ratio close to 2∶ 1 at a high temperature (above 750 ℃) by the lattice oxygen of CeO2; methane cracking is found when the reduction degree of CeO2 was above 5.0% at 850 ℃ in methane isothermal reaction.CeO2-δ obtained from methane isothermal reaction can split water to generate CO-free hydrogen and renew its lattice oxygen at 700 ℃; simultaneously, deposited carbon is selectively oxidized to CO2 by steam following the reaction (C+2H2O→CO2+2H2).Slight deactivation in terms of amounts of desired products (syngas and hydrogen) is observed in ten repetitive two-step SRM process due to the carbon deposition on CeO2 surface as well as sintering of CeO2.

  8. Analysis Of CaSO4 Precipitation At Seawater Desalination Process

    International Nuclear Information System (INIS)

    Analysis of CaSO4 precipitation has been undertaken. The experiment performed by heating seawater sample from Muara Karang at temperature series from 50, 60, 70, 80, 90 and 95oC for 30 minutes, respectively. CaSO4 precipitate observed through out it each temperatures heating predicted by .calcium ion content, pH and sulfate ion remains in seawater sample solution. According to the experiment result that the calcium sulfate precipitate of seawater desalination through the MSF installation should be exceed supersaturation condition which depend on concentration factor and heating temperatures. The heating temperature below 95oC with concentration factor is 1, 2 and 3 that CaSO4 precipitate unachievable. It means that the MSF desalination installation ,especially at heating range along the inlet pipe into before the brine heater calcium sulfate not occurs

  9. CaSO4 and cationic polyelectrolyte as possible pectin precipitants in sugar beet juice clarification

    OpenAIRE

    Kuljanin Tatjana; Lončar Biljana; Pezo Lato; Nićetin Milica; Knežević Violeta; Jevtić-Mučibabić Rada

    2015-01-01

    Three pectin preparations were isolated from fresh sugar beet pulp during the 150 minutes of extraction, at pH values of 1, 3.5 and 8.5. CaSO4 precipitant was added to 100 cm3 of 0.1% (wt) solution of pectin. Studies were performed with 9 different concentrations of CaSO4 solution (50-450 mg dm-3) with the addition of a cationic polyelectrolyte (cationic PAM) in concentrations of 3 and 5 mg dm-3. The efficiency of pectin precipitation was monitored by measu...

  10. Coencapsulation of oxygen carriers and glucose oxidase in polyelectrolyte complex capsules for the enhancement of D-gluconic acid and delta-gluconolactone production.

    Science.gov (United States)

    Bucko, Marek; Gemeiner, Peter; Vikartovská, Alica; Mislovicová, Danica; Lacík, Igor; Tkác, Ján

    2010-04-01

    A novel encapsulated oxidative biocatalyst comprising glucose oxidase (GOD) coencapsulated with oxygen carriers within polyelectrolyte complex capsules was developed for the production of D-gluconic acid and delta-gluconolactone. The capsules containing immobilized GOD were produced by polyelectrolyte complexation with sodium alginate (SA) and cellulose sulfate (CS) as polyanions, poly(methylene-co-guanidine) (PMCG) as the polycation, CaCl(2) as the gelling agent and NaCl as the antigelling agent (GOD-SA-CS/PMCG capsules). Poly(dimethylsiloxane) (PDMS) and an emulsion of n-dodecane (DOD) or perfluorodecaline (PFD) with PDMS were used as the oxygen carriers and MnO(2) was used as a hydrogen peroxide decomposition catalyst. Water-soluble PDMS was found to act as both an oxygen carrier and an emulsifier of water-insoluble DOD and PFD. Stable microcapsules could be produced with concentrations of up to 4% (w/w) of PDMS, 10% (w/w) of DOD and PFD, and 25% (w/w) of MnO(2) in the polyanion solution of SA and CS. Roughly a two-fold increase in the GOD activity from 21.0+/-1.1 to 38.4+/-2.0 U*g(-1) and product space-time yields (STY) from 44.3+/-2.0 to 83.4+/-3.4 g*H*day(-1) could be achieved utilizing coencapsulated oxygen carriers compared to GOD encapsulated in the absence of oxygen carriers. This enhanced production does not significantly depend on the selected oxygen carrier under the conditions used in this study.

  11. Experiments on biomass gasification using chemical looping with nickel-based oxygen carrier in a 25 kWth reactor

    International Nuclear Information System (INIS)

    Biomass gasification using chemical looping (BGCL) is an innovative biomass gasification technology, which utilizes lattice oxygen from oxygen carrier instead of molecular oxygen from air. This work attempted to investigate the BGCL performance with nickel-based oxygen carrier in a 25 kWth reactor. The new prototype is composed of a high velocity fluidized bed as an air reactor, a cyclone, a bubbling fluidized bed as a fuel reactor, and a loop-seal. At first, the major reactions in the process were presented and chemical reaction thermodynamics in the fuel reactor was analyzed. The NiO/Al2O3 oxygen carrier was then applied in the reactor. Different variables, such as gasification temperature, steam-to-biomass (S/B) ratio and NiO content, were analyzed. The carbon conversion efficiency increased smoothly within the temperature range of 650–850 °C, while the syngas yield reached the maximum of 0.33 Nm3kg−1 at 750 °C. Additionally, based on the tradeoff between carbon conversion efficiency and syngas yield, it was concluded that 30 wt.% was the optimal NiO content. Besides, in order to get high quality syngas with low CO2 emission, CaO-decorated NiO/Al2O3 oxygen carrier was investigated. Experimental results showed that the addition of CaO enhanced the biomass gasification process and increased the syngas yield. - Highlights: • A new 25 kWth prototype was made in this study. • NiO was selected as oxygen carrier in the new prototype. • Gasification temperature, steam-to-biomass ratio and NiO content were investigated. • CaO-decorated NiO/Al2O3 was tested to produce high quality syngas

  12. Luminescence in CaSO4 : Dy phosphor - dependence on grain agglomeration, sintering temperature, sieving and washing

    Science.gov (United States)

    Lakshmanan, A. R.; Jose, M. T.; Ponnusamy, V.; Vivek Kumar, P. R.

    2002-02-01

    In the recently developed high-sensitive CaSO4 : Dy phosphor, sieving before the high-temperature sintering treatment has successfully eliminated particle agglomeration during subsequent sintering, and has further enhanced its thermostimulated luminescence (TSL) sensitivity to γ-rays. The reduction in TSL sensitivity of higher sized grains observed earlier following the procedure of sieving after sintering has also more or less vanished. Maximum TSL sensitivity is seen after sintering around 700°C, whereas maximum photoluminescent (PL) sensitivity is seen after sintering around 325°C. While the observed increase in TSL sensitivity (by 30%) with increasing sintering temperature in the range 325-700°C is explained on the basis of diffusion of Dy3+ ions from the surface to the whole volume of the grains (0-75 µm), the drastic decrease (by a factor of 3) in PL sensitivity with increasing sintering temperature is explained on the basis of change in the Dy3+ environment on the grain surface perhaps due to oxygen incorporation. Washing with water and acetone, which affect mainly the surface traps, enhances the PL sensitivity of CaSO4 : Dy slightly; however, it does not influence TSL sensitivity very significantly. Grinding reduces PL in general, but no such trend was noticed in TSL which supports the conclusion that PL originates mainly from surface traps since grinding affects mainly the grain surface. However, the sharp reduction in TSL and PL sensitivities observed at 400°C indicates that an unusual process takes place near that sintering temperature.

  13. Molluscan mega-hemocyanin: an ancient oxygen carrier tuned by a ~550 kDa polypeptide

    Directory of Open Access Journals (Sweden)

    Harasewych Myroslaw G

    2010-05-01

    Full Text Available Abstract Background The allosteric respiratory protein hemocyanin occurs in gastropods as tubular di-, tri- and multimers of a 35 × 18 nm, ring-like decamer with a collar complex at one opening. The decamer comprises five subunit dimers. The subunit, a 400 kDa polypeptide, is a concatenation of eight paralogous functional units. Their exact topology within the quaternary structure has recently been solved by 3D electron microscopy, providing a molecular model of an entire didecamer (two conjoined decamers. Here we study keyhole limpet hemocyanin (KLH2 tridecamers to unravel the exact association mode of the third decamer. Moreover, we introduce and describe a more complex type of hemocyanin tridecamer discovered in fresh/brackish-water cerithioid snails (Leptoxis, Melanoides, Terebralia. Results The "typical" KLH2 tridecamer is partially hollow, whereas the cerithioid tridecamer is almost completely filled with material; it was therefore termed "mega-hemocyanin". In both types, the staggering angle between adjoining decamers is 36°. The cerithioid tridecamer comprises two typical decamers based on the canonical 400 kDa subunit, flanking a central "mega-decamer" composed of ten unique ~550 kDa subunits. The additional ~150 kDa per subunit substantially enlarge the internal collar complex. Preliminary oxygen binding measurements indicate a moderate hemocyanin oxygen affinity in Leptoxis (p50 ~9 mmHg, and a very high affinity in Melanoides (~3 mmHg and Terebralia (~2 mmHg. Species-specific and individual variation in the proportions of the two subunit types was also observed, leading to differences in the oligomeric states found in the hemolymph. Conclusions In cerithioid hemocyanin tridecamers ("mega-hemocyanin" the collar complex of the central decamer is substantially enlarged and modified. The preliminary O2 binding curves indicate that there are species-specific functional differences in the cerithioid mega-hemocyanins which might reflect

  14. Electron spin resonance evaluation of pure CaSO4 and as a phosphor doped with P and Dy.

    Science.gov (United States)

    de Jesus, E F O; Rossi, A M; Lopes, R T

    2002-01-01

    Polycrystalline CaSO4 powder, doped with different elements but mainly rare earths, is one of the most interesting thermoluminescent (TL) materials. Although many electron spin resonance (ESR) analyses have been reported for these materials few studies have been published about the potential of CaSO4 for ESR dosimetry; almost all studies used CaSO4:Dy with a very low Dy concentration as the material for TL measurements. Pure CaSO4 from Merck was used to prepare CaSO4:Dy and CaSO4:P:Dy with different Dy concentrations. Samples were annealed at 600 degrees C for 1 h before irradiation in a Gammacell 220 irradiator with a 60Co gamma source at a dose rate of 100 Gy x min(-1). The ESR spectra of the pure CaSO4 and CaSO4 doped with P and Dy show the lines usually observed with these types of material, with the factor g around 2.036 and an intense line at g = 2.0011 found only in the pure material. This line, probably an axial SO4-, grows linearly with absorbed dose until 1.0 kGy and shows good stability with time. The line should be stabilized by matrix impurities because it can be removed by a simple treatment with hot sulphuric acid.

  15. Investigation of the performance of a copper based oxygen carrier for chemical looping combustion in a 120 kW pilot plant for gaseous fuels

    International Nuclear Information System (INIS)

    Highlights: • A Cu based oxygen carrier for chemical looping combustion has been tested. • A 120 kW pilot plant designed as dual circulating fluidized bed has been used. • Solids inventory and circulation have been identified as critical for performance. • The results are compared with other pilot plants using the same oxygen carrier. • Recommendations for improved reactor designs have been made based on the results. - Abstract: A copper based oxygen carrier prepared by impregnation on a highly porous alumina support (14.2 wt% active CuO) has been tested in a 120 kW chemical looping pilot plant. This oxygen carrier has already been under investigation in other pilot plants up to 10 kW fuel power and showed very good performance, i.e. full fuel conversion was achieved. During the experiments, natural gas has been used as fuel and variations of several process parameters like temperature, fuel power, solids inventory and solids circulation rate have been performed. The copper particles showed good performance regarding conversion of CO and H2 (almost full conversion) but only moderate conversion of CH4 (up to 80%) was achieved. The three process parameters fuel reactor temperature, solids circulation between air and fuel reactor and solids inventory have been identified as significant parameters for fuel conversion, i.e. increasing one of these parameters improves fuel conversion. Continuous analysis of the oxygen carrier particles revealed an initial decay of active CuO content caused by attrition on the external surface of the particles. The CuO content stabilized after 30 h of operation at around 9 wt% and no further decrease was observed

  16. A review of blood substitutes: examining the history, clinical trial results, and ethics of hemoglobin-based oxygen carriers

    Directory of Open Access Journals (Sweden)

    Jiin-Yu Chen

    2009-01-01

    Full Text Available The complications associated with acquiring and storing whole blood for transfusions have launched substantial efforts to develop a blood substitute. The history of these efforts involves a complicated mixture of science, ethics, and business. This review focuses on clinical trials of the three hemoglobin-based oxygen carriers (HBOC that have progressed to Phase II or III clinical trials: HemAssist (Baxter; Deerfield, IL, US, PolyHeme (Northfield; Evanston, IL, US, and Hemopure (Biopure; Cambridge, MA, US. Published animal studies and clinical trials carried out in a perioperative setting have demonstrated that these products successfully transport and deliver oxygen, but all may induce hypertension and lead to unexpectedly low cardiac outputs. Overall, these studies suggest that HBOCs resulted in only modest blood saving during and after surgery, no improvement in mortality and an increased incidence of adverse reactions. To date, the results from these perioperative studies have not led to regulatory approval. All three companies instead chose to focus their efforts on large trials of trauma patients in the pre-hospital setting. Baxter abandoned the development of HemAssist after a trial in the U.S. was prematurely halted when the first 100 patients showed significantly increased mortality rates as compared to patients treated with blood products. Northfield's PolyHeme trial demonstrated a non-significant trend towards increased mortality and a very modest reduction in the subsequent need for blood. The testing of Biopure's Hemopure for trauma patients has been halted for several years because of FDA concerns over trial design and study justification. Ethical concerns have also been raised regarding the design and implementation of all HBOC clinical trials. Thus, the available evidence suggests that HemAssist, Polyheme, and Hemopure are associated with a significant level of cardiovascular dysfunction. The next generation of HBOCs remains

  17. Thermoluminescence characteristics of mixture of CaSO4 and SiO2

    International Nuclear Information System (INIS)

    The study on the characteristics of thermoluminescence (TL) spectra for the mixture of CaSO4 and SiO2 was carried out. Four kinds of mixture of CaSO4 and SiO2 with various mass ratios, such as 1:2, 1:1, 4:1, 9:1, were prepared and tested. Four TL peaks are 110, 160, 240, 380 degree C, and they show linearity and stabilization. Especially, the peak of 240 degree C can be used to dating. TL characteristics of gypsum and calcium sulfate were compared. The data can help us in analysis the glow curve for gypsum. It could be useful to luminescence dating for gypsum. (authors)

  18. Influence of the formation- and passivation rate of boron-oxygen defects for mitigating carrier-induced degradation in silicon within a hydrogen-based model

    Energy Technology Data Exchange (ETDEWEB)

    Hallam, Brett, E-mail: brett.hallam@unsw.edu.au; Abbott, Malcolm; Nampalli, Nitin; Hamer, Phill; Wenham, Stuart [School of Photovoltaics and Renewable Energy Engineering, Level 1 Tyree Energy Technologies Building, University of New South Wales, Kensington, NSW 2052 (Australia)

    2016-02-14

    A three-state model is used to explore the influence of defect formation- and passivation rates of carrier-induced degradation related to boron-oxygen complexes in boron-doped p-type silicon solar cells within a hydrogen-based model. The model highlights that the inability to effectively mitigate carrier-induced degradation at elevated temperatures in previous studies is due to the limited availability of defects for hydrogen passivation, rather than being limited by the defect passivation rate. An acceleration of the defect formation rate is also observed to increase both the effectiveness and speed of carrier-induced degradation mitigation, whereas increases in the passivation rate do not lead to a substantial acceleration of the hydrogen passivation process. For high-throughput mitigation of such carrier-induced degradation on finished solar cell devices, two key factors were found to be required, high-injection conditions (such as by using high intensity illumination) to enable an acceleration of defect formation whilst simultaneously enabling a rapid passivation of the formed defects, and a high temperature to accelerate both defect formation and defect passivation whilst still ensuring an effective mitigation of carrier-induced degradation.

  19. Effects of excess oxygen introduced during sputter deposition on carrier mobility in as-deposited and postannealed indium-tin-oxide films

    International Nuclear Information System (INIS)

    Electrical and structural properties of indium-tin-oxide (ITO) films with various Sn concentrations deposited under a high oxygen partial pressure were examined to find out how the excess oxygen behaves as a scattering and trapping center of electron carriers and to show evidence that excess oxygen is weakly bound with Sn4+ ions on In3+ sites with single-charge SnIn . ITO films with Sn concentrations of 1-25 wt % were deposited on glass substrates by rf sputtering under various oxygen concentrations in the discharge gas (0.3%-100%); the substrate temperature was kept at 773 K during deposition. With increasing O2 flow ratio in the discharge gas from 0.3% to 100%, the Hall mobility and the carrier density were found to decrease from ∼40 to ∼20 cm2 V-1 s-1 and from ∼5.0x1020 to ∼2.0x1018 cm-3, respectively. The dependence of the slope of mobility-temperature curve on the O2 flow ratio and Sn concentration has been examined. For high Sn concentration, the slope changes from negative to positive as the O2 flow rate increases. The slope of the curve for a film with Sn concentration of 8 wt % deposited at an O2 flow ratio of 100% changes from positive to negative after postannealing at 473 K for 30 min. in N2. These results suggest that the oxygen attaches weakly to Sn4+ and that the oxygen plays a role in the scattering and trapping center. It is also found that oxygen ions mainly exist not in interstitial quasianion sites but in the grain boundaries because of the constant lattice parameter after annealing

  20. The Bagni di Lucca thermal waters (Tuscany, Italy): an example of Ca-SO 4 waters with high Na/Cl and low Ca/SO 4 ratios

    Science.gov (United States)

    Boschetti, Tiziano; Venturelli, Giampiero; Toscani, Lorenzo; Barbieri, Maurizio; Mucchino, Claudio

    2005-06-01

    The Bagni di Lucca thermal waters (Lucca province, Tuscany, Italy) have been well known since the Middle Age for their alleged curative properties. In the present work, the waters have been analysed for major and trace components and for O, H, S and Sr isotopes. The δ 2H and δ 18O values indicate a meteoric origin of the waters and the tritium content suggests long-term (more than 40 years) circulation at depth. The δ 34S values in dissolved sulphate of the warmest waters (Doccione, Paolina, Bernabò, Demidoff, Cova) indicate interaction with Triassic evaporites; however, the δ 34S values as well as the 87Sr/ 86Sr ratios in the waters appear to be a little higher (on average 17.6±0.4‰ and 0.70834±0.00006, respectively) than in Triassic sulphate minerals from the Northern Apennines (16.0±0.5‰ and 0.70778±0.00011). The waters are Ca-sulphate and characterised by high Na/Cl (≌2) and low Ca/SO 4 (≌0.7) mole ratios, high Sr (≤12 mg/L), F (≤4.2 mg/L), As (≤80 μg/L), Cs (≤70 μg/L), Rb (≤107 μg/L) and salinity (up to 3087 mg/L of total dissolved solids), low alkalinity, and pH in the range 6.3-7.5. Assuming equilibrium of the waters with anhydrite and chalcedony, the evaluated temperature and pressure are about 70-75 °C and 200-300 bar; considering the pressure as hydrostatic, the evaluated depth of equilibration approaches that of the metamorphic basement (about 3.0-3.8 km) underlying the carbonate-evaporite formations occurring in the area. Thermodynamic computations indicate that the high Na/Cl ratio and the low Ca/SO 4 ratio in the waters may be due to progressive dissolution of albite, anhydrite, dolomite and carbon dioxide accompanied by calcite precipitation. The linear correlations between the major and trace components, including 2H and 18O, demonstrate that thermal springs undergo dilution by low-salinity shallow waters which are recharged at low elevation.

  1. Improvement in the dosimetric CaSO4: Dy obtention method

    International Nuclear Information System (INIS)

    With the purpose of saving up in the dosimetric CaSO4: Dy production, a new method was developed to obtain single crystals. In this method the nitrogen flux used to carry the acid vapour was substituted by compressed air. It was compared all dosimetric properties of the crystals. There is no alteration in the glow curve. The sensitivity is the same in both cases and the lower detection limit is 3.8 x 10-8C.Kg-1 (150 μR)

  2. CaSO4:DY,Mn: A new and highly sensitive thermoluminescence phosphor for versatile dosimetry

    Science.gov (United States)

    Bahl, Shaila; Lochab, S. P.; Kumar, Pratik

    2016-02-01

    With the advent of newer techniques for dose reduction coupled with the development of more sensitive detectors, the radiation doses in radiological medical investigation are decreasing. Nevertheless, keeping the tenet in mind that all radiation doses could entail risk, there is a need to develop more sensitive dosimeters capable of measuring low doses. This paper gives the account of the development of a new and sensitive phosphor CaSO4:Dy,Mn and its characterization. The standard production procedure based on the recrystallization method was used to prepare CaSO4:Dy,Mn. The Thermoluminescence (TL) studies were carried out by exposing it with gamma radiation (Cs-137) from 10 μGy to 100 Gy. The theoretical studies to determine the number of peaks and kinetic parameters related to the TL glow peaks in CaSO4:Dy,Mn was performed using the Computerized Glow Curve Deconvolution (CGCD) method. Experiments were performed to determine optimum concentration of the dopants Dysprosium (Dy) and Mangnese (Mn) in the host CaSO4 so that maximum sensitivity of the phosphor may be achieved. The optimum dopant concentration turned out to be 0.1 mol%. As there were two dopants Dy and Mn their relative ratio were varied in steps of 0.025 keeping the concentration of total dopant (Dy and Mn) 0.1 mol% always. The maximum TL intensity was seen in the CaSO4:Dy(0.025),Mn(0.075) combination. The TL sensitivity of this phosphor was found to be about 2 and 1.8 times higher than that of popular phosphor CaSO4:Dy and LiF:Mg,Cu,P (TLD-700H) respectively. This new phosphor CaSO4:Dy,Mn showed fading of 11% which is similar to that of the standard phosphor CaSO4:Dy. The paper concludes that the new, highly sensitive TL phosphor CaSO4:Dy,Mn has shown higher sensitivity and hence the potential to replace commonly used CaSO4:Dy.

  3. CaMn0.875Ti0.125O3 as oxygen carrier for chemical-looping combustion with oxygen uncoupling (CLOU)—Experiments in a continuously operating fluidized-bed reactor system

    KAUST Repository

    Rydén, Magnus

    2011-03-01

    Particles of the perovskite material CaMn0.875Ti0.125O3 has been examined as oxygen carrier for chemical-looping with oxygen uncoupling, and for chemical-looping combustion of natural gas, by 70h of experiments in a circulating fluidized-bed reactor system. For the oxygen uncoupling experiments, it was found that the particles released O2 in gas phase at temperatures above 720°C when the fuel reactor was fluidized with CO2. The effect increased with increased temperature, and with the O2 partial pressure in the air reactor. At 950°C, the O2 concentration in the outlet from the fuel reactor was in the order of 4.0vol%, if the particles were oxidized in air. For the chemical-looping combustion experiments the combustion efficiency with standard process parameters was in the order of 95% at 950°C, using 1000kg oxygen carrier per MW natural gas, of which about 30% was located in the fuel reactor. Reducing the fuel flow so that 1900kg oxygen carrier per MW natural gas was used improved the combustion efficiency to roughly 99.8%. The particles retained their physical properties, reactivity with CH4 and ability to release gas-phase O2 reasonably well throughout the testing period and there were no problems with the fluidization or formation of solid carbon in the reactor. X-ray diffraction showed that the particles underwent changes in their phase composition though. © 2010 Elsevier Ltd.

  4. Effects of heliox as carrier gas on ventilation and oxygenation in an animal model of piston-type HFOV: a crossover experimental study

    Directory of Open Access Journals (Sweden)

    Hiroma Takehiko

    2010-11-01

    Full Text Available Abstract Objective This study aimed to compare gas exchange with heliox and oxygen-enriched air during piston-type high-frequency oscillatory ventilation (HFOV. We hypothesized that helium gas would improve both carbon dioxide elimination and arterial oxygenation during piston-type HFOV. Method Five rabbits were prepared and ventilated by piston-type HFOV with carrier 50% helium/oxygen (heliox50 or 50% oxygen/nitrogen (nitrogen50 gas mixture in a crossover study. Changing the gas mixture from nitrogen50 to heliox50 and back was performed five times per animal with constant ventilation parameters. Arterial blood gas, vital function and respiratory test indices were recorded. Results Compared with nitrogen50, heliox50 did not change PaCO2 when stroke volume remained constant, but significantly reduced PaCO2 after alignment of amplitude pressure. No significant changes in PaO2 were seen despite significant decreases in mean airway pressure with heliox50 compared with nitrogen50. Conclusion This study demonstrated that heliox enhances CO2 elimination and maintains oxygenation at the same amplitude but with lower airway pressure compared to air/O2 mix gas during piston-type HFOV.

  5. Effect of the hemoglobin-based oxygen carrier HBOC-201 on laboratory instrumentation: cobas integra, chiron blood gas analyzer 840, Sysmex SE-9000 and BCT.

    Science.gov (United States)

    Wolthuis, A; Peek, D; Scholten, R; Moreira, P; Gawryl, M; Clark, T; Westerhuis, L

    1999-01-01

    As part of a clinical trial, we evaluated the effects of the hemoglobin-based oxygen-carrier (HBOC) HBOC-201 (an ultrapurified, stroma-free bovine hemoglobin product, Biopure, Cambridge, MA, USA) on our routine clinical chemistry analyzer (Cobas Integra, F. Hoffmann-La Roche Ltd, Basel, Switzerland ), blood gas analyzer (Chiron 840, Chiron Diagnostics Corporation, East Walpole, MA, USA), routine hemocytometry analyzer (Sysmex SE-9000, TOA Medical Electronics Co Ltd., Kobe, Japan), hemostasis analyzer (BCT, Dade-Behring, Marburg, Germany) and bloodbanking system (Dia-Med-ID Micro Typing System, DiaMed AG, Cressier, Switzerland). The maximum tested concentration of HBOC-201 was 65 g/l. Of the 27 routine clinical chemistry tests challenged with HBOC-201, bilirubin-direct, creatine kinase MB-fraction (CK-MB), creatine kinase (CK), gamma-glutamyltransferase (GGT), magnesium and uric acid were influenced by even low concentrations of HBOC-201. These tests were excluded from use on the plasma of patients treated with HBOC-201. Since the non-availability of the cardiac marker CK-MB may lead to problems in acute situations, we introduced the qualitative Trop T-test (Boehringer Mannheim), which was not influenced. The applicability of another nine tests was limited by the concentration of the HBOC-201 in the patients' plasma. No interference of HBOC-201 in routine hemocytometry, hemostasis-analysis and red-blood cell agglutination detection (blood-bank tests) was observed. Although immediate patient-care was not compromised, routine use of hemoglobin-based oxygen carriers will have a strong impact on logistical management. The development of robust laboratory tests free from the interference of the pigmented oxygen carriers should therefore precede its introduction into routine transfusion medicine.

  6. A quantitative discussion on band-gap energy and carrier density of CdO in terms of temperature and oxygen partial pressure

    International Nuclear Information System (INIS)

    Calculations relative to the band-gap energy shift and carrier spatial density in cadmium oxide are performed in terms of the oxygen partial pressure and substrate temperature relative to the deposition process in the crystal growth of the above material, starting from the consideration of the Fermi energy of an exciton gas. In particular, the band-gap shift experienced by cadmium oxide in terms of the corresponding partial pressure of oxygen is considered as well as the electron spatial density as a function of the pressure in question. Influence of temperature is discussed by estimating the average rate of variation of the band-gap shift versus temperature. In addition, the sensitivity of the above-mentioned shift to temperature is studied by means of a suitable parameter

  7. Dosimetric characteristics and radiation monitoring with CaSO4(Dy):NaCl pellets

    International Nuclear Information System (INIS)

    CaSO4(Dy):NaCl Tl dosimeters, in the form of pellets, are used in the field for a period of one month. Before using these pellets for environmental and personnel radiation monitoring some of the important dosimetric characteristics like fading reusability and effect of ambient light are investigated and described. The pellets are used with plastic and lead filters for personnel and environmental radiation monitoring and the results obtained with the lead filters are in good agreement with those of the energy independent LiF dosimeters. A new combination of plastic, aluminium and lead filters is suggested for dose measurements in a mixed field of X, gamma and beta radiations. (Author)

  8. Preparation and structural characterization of the thermoluminescent material CaSO4: Dy

    International Nuclear Information System (INIS)

    The grade of crystallinity of a material is important so that the one is presented the thermoluminescence phenomenon; for what is necessary to study those structural characteristic of a TL material and to correlate them with its TL response when being irradiated with ionizing radiation. The calcium sulfate activated with Dysprosium (CaSO4: Dy) it is a material that has demonstrated its efficiency in the dosimetry of the ionizing radiation for the thermoluminescence method. In this work the structural characterization of this prepared material for the recrystallization method by means of the evaporation of the solvent and their relationship with their TL response is presented. The results showed that the best material to be used in thermoluminescent dosimetry presents a crystalline structure in orthorhombic phase and a particle size in the interval of 80 μm to 200 μm. (Author)

  9. Improvement of oxygen supply by an artificial carrier in combination with normobaric oxygenation decreases the volume of tissue hypoxia and tissue damage from transient focal cerebral ischemia

    NARCIS (Netherlands)

    Seiffge, David J.; Lapina, Natalia E.; Tsagogiorgas, Charalambos; Theisinger, Bastian; Henning, Robert H.; Schilling, Lothar

    2012-01-01

    Tissue hypoxia may play an important role in the development of ischemic brain damage. In the present study we investigated in a rat model of transient focal brain ischemia the neuroprotective effects of increasing the blood oxygen transport capacity by applying a semifluorinated alkane (SFA)-contai

  10. Phase relation of CaSO4 at high pressure and temperature up to 90 GPa and 2300 K

    Science.gov (United States)

    Fujii, Taku; Ohfuji, Hiroaki; Inoue, Toru

    2016-05-01

    Calcium sulfate (CaSO4), one of the major sulfate minerals in the Earth's crust, is expected to play a major role in sulfur recycling into the deep mantle. Here, we investigated the crystal structure and phase relation of CaSO4 up to ~90 GPa and 2300 K through a series of high-pressure experiments combined with in situ X-ray diffraction. CaSO4 forms three thermodynamically stable polymorphs: anhydrite (stable below 3 GPa), monazite-type phase (stable between 3 and ~13 GPa) and barite-type phase (stable up to at least 93 GPa). Anhydrite to monazite-type phase transition is induced by pressure even at room temperature, while monazite- to barite-type transition requires heating at least to 1500 K at ~20 GPa. The barite-type phase cannot always be quenched from high temperature and is distorted to metastable AgMnO4-type structure or another modified barite structure depending on pressure. We obtained the pressure-volume data and density of anhydrite, monazite- and barite-type phases and found that their densities are lower than those calculated from the PREM model in the studied P-T conditions. This suggests that CaSO4 is gravitationally unstable in the mantle and fluid/melt phase into which sulfur dissolves and/or sulfate-sulfide speciation may play a major role in the sulfur recycling into the deep Earth.

  11. Isothermal gas chromatography of short-lived Hf isotopes and element 104 in chlorinating, oxygen containing carrier gas

    Energy Technology Data Exchange (ETDEWEB)

    Jost, D.T.; Dressler, R.; Eichler, B.; Piguet, D.; Tuerler, A.; Gaeggeler, H.W.; Gaertner, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Grantz, M.; Huebener, S. [FZR (Germany); Buklanov, G.; Lebedev, V.; Timkhin, S.; Vedeneev, M.V.; Yakushev, A.; Zvara, I. [Joint Inst. for Nuclear Research, Dubna (Russian Federation)

    1997-09-01

    Based on thermodynamic state functions retention times of Hf and element 104 were calculated in the case of the simple adsorption of the tetrachlorides and the case of a complex adsorption involving a substitution process with oxygen in the chlorinating gas. Preliminary results for {sup 261}104 and Hf are shown. (author) 1 fig., 1 tab., 3 refs.

  12. CeO2 as the Oxygen Carrier for Partial Oxidation of Methane to Synthesis Gas in Molten Salts: Thermodynamic Analysis and Experimental Investigation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new technique - the direct partial oxidation of methane to synthesis gas using lattice oxygen in molten salts medium has been introduced. Using CeO2 as the oxygen carrier, thermodynamic data were calculated in the reaction process, and the results indicated that direct partial oxidation of methane to synthesis gas using lattice oxygen of cerium oxide is feasible in theory. In a stainless steel reactor, the effects of temperature and varying amounts of γ-Al2O3 supported CeO2 on CH4 conversion,H2 and CO selectivity, were investigated, respectively. The results show that 10% CeO2/γ-Al2O3 has the maximal reaction activity at a temperature of 865 ℃ and above, the H2/CO ratio in the gas that has been produced reaches 2 and the CH4 conversion, H2 and CO selectivity reached the following percentages: i.e.61%, 89%, and 91% at 870 ℃, respectively. In addition, increase of reaction temperature is favorable for the partial oxidation of methane.

  13. Microscale electrochemical cell using plaster (CaSO4 as liquid junction

    Directory of Open Access Journals (Sweden)

    Yuthapong Udnan

    2008-10-01

    Full Text Available A microscale apparatus for electrochemical cell in which plaster (CaSO4 was used as liquid junction has been developed. A glass tube (0.5 cm ID x 5.0 cm was used to prepare each half-cell. The potentials of the resulting galvanic cells were measured by a multimetre and were compared to those of the galvanic cells in which agar was used as liquid junction. It was found that the potentials produced by the galvanic cells with plaster as liquid junction are not significantly different from those of the cells with agar as liquid junction and close to the theoretical values. In addition, when the developed apparatus was used for the study of electrolysis of potassium iodide solution, it was found that the electrolytic cell made from the microscale apparatus with plaster liquid junction can distinctly separate the reactions occurring at the anode and the cathode. Moreover, the lifetime of the plaster liquid junction is much greater than that of the agar liquid junction.

  14. Cobalt(Il) Salen Complex with Two Aza-crown Pendants and Its Analogues as Synthetic Oxygen Carriers

    Institute of Scientific and Technical Information of China (English)

    WEI,Xing-Yue(魏星跃); LI,Jian-Zhang(李建章); MAO,Zhi-Hua(毛治华); ZHOU,Bo(周波); QIN,Sheng-Ying(秦圣英)

    2004-01-01

    Salen with two aza-crown ether pendants H2L1 and its analogues H2La-H2L4 were successfully synthesized starting from benzo-10-aza-15-crown-5 (BN15C5) or morpholine. Their structures were characterized by IR, MS,1H NMR and elemental analysis, and were confirmed by X-ray diffraction analysis of H2L1. Moreover, the saturated oxygen uptake of their cobalt(II) complexes CoL1-CoL4 in diethyleneglycol dimethyl ether was determined at different temperature. The oxygenation contants ( Ko2 ) and thermodynamic parameters (△H° and △S°) were calculated.The modulation of O2-binding capabilities by pendant substituents were investigated as compared with the parent Schiff base complex CoL5 (CoSalen). The results indicate that the dioxygen affinities of CoL have been much more enhanced by aza-crown pendants than that by morpholino pendants, and the O2-binding capabilities of CoL1 and CoLa with aza-crown pendants would also be enhanced by adding alkali metal cations.

  15. Characterization study and five-cycle tests in a fixed-bed reactor of titania-supported nickel oxide as oxygen carriers for the chemical-looping combustion of methane.

    Science.gov (United States)

    Corbella, Beatriz M; de Diego, Luis F; García-Labiano, Francisco; Adánez, Juan; Palaciost, José M

    2005-08-01

    Recent investigations have shown that in the combustion of carbonaceous compounds CO2 and NOx emissions to the atmosphere can be substantially reduced by using a two stage chemical-looping process. In this process, the reduction stage is undertaken in a first reactor in which the framework oxygen of a reducible inorganic oxide is used, instead of the usual atmospheric oxygen, for the combustion of a carbonaceous compound, for instance, methane. The outlet gas from this reactor is mostly composed of CO2 and steam as reaction products and further separation of these two components can be carried out easily by simple condensation of steam. Then, the oxygen carrier found in a reduced state is transported to a second reactor in which carrier regeneration with air takes place at relatively low temperatures, consequently preventing the formation of thermal NOx. Afterward, the regenerated carrier is carried to the first reactor to reinitiate a new cycle and so on for a number of repetitive cycles, while the carrier is able to withstand the severe chemical and thermal stresses involved in every cycle. In this paper, the performance of titania-supported nickel oxides has been investigated in a fixed-bed reactor as oxygen carriers for chemical-looping combustion of methane. Samples with different nickel oxide contents were prepared by successive incipient wet impregnations, and their performance as oxygen carriers was investigated at 900 degrees C and atmospheric pressure in five-cycle fixed-bed reactor tests using pure methane and pure air for the respective reduction and regeneration stages. The evolution of the outlet gas composition in each stage was followed by gas chromatography, and the involved chemical, structural, and textural changes of the carrier in the reactor bed were studied by using different characterization techniques. From the study, it is deduced that the reactivity of these nickel-based oxygen carriers is in the two involved stages and almost independent

  16. Chemical Looping with Copper Oxide as Carrier and Coal as Fuel; Boucle chimique pour la combustion du charbon avec un transporteur d'oxygene a base d'oxyde de cuivre

    Energy Technology Data Exchange (ETDEWEB)

    Eyring, E.M.; Konya, G. [Department of Chemistry, Institute for Clean and Secure Energy, University of Utah, Salt Lake City, UT 84112 (United States); Lighty, J.S.; Sahir, A.H.; Sarofim, A.F.; Whitty, K. [Department of Chemical Engineering, Institute for Clean and Secure Energy, University of Utah, Salt Lake City, UT 84112 (United States)

    2011-03-15

    A preliminary analysis has been conducted of the performance of a Chemical Looping system with Oxygen Uncoupling (CLOU) with copper oxide as the oxygen carrier and coal approximated by carbon as the fuel. The advantages of oxygen uncoupling are demonstrated by providing the energy balances, the circulation rate of oxygen carrier, the oxygen carrier mass loadings, the carbon burnout and oxygen partial pressure in the fuel reactor. Experimental data on the cycling of cuprous oxide to cupric oxide and kinetics for the oxidation and decomposition reactions of the oxides were obtained for use in the analysis. For this preliminary study unsupported oxides were utilized. The decomposition temperatures were rapid at the high temperature of 950 C selected for the fuel reactor. The oxidation kinetics peaked at about 800 C with the decrease in rate at higher temperatures, a decrease which is attributed in the literature to the temperature dependence of the diffusional resistance of the CuO layer surrounding the Cu{sub 2}O; the diffusion occurs through grain boundaries in the CuO layers and the rate of diffusion decreases as a consequence of growth of CuO grains with increasing temperature. The analysis shows the advantages of CLOU in providing rapid combustion of the carbon with carbon burnout times lower than the decomposition times of the oxygen carrier. For the full potential of CLOU to be established additional data are needed on the kinetics of supported oxides at the high temperatures ({>=}850 C) at which oxygen is released by the CuO in the fuel reactor. (authors)

  17. Oxygen "getter" effects on microstructure and carrier transport in low temperature combustion-processed a-InXZnO (X = Ga, Sc, Y, La) transistors.

    Science.gov (United States)

    Hennek, Jonathan W; Smith, Jeremy; Yan, Aiming; Kim, Myung-Gil; Zhao, Wei; Dravid, Vinayak P; Facchetti, Antonio; Marks, Tobin J

    2013-07-24

    In oxide semiconductors, such as those based on indium zinc oxide (IXZO), a strong oxygen binding metal ion ("oxygen getter"), X, functions to control O vacancies and enhance lattice formation, hence tune carrier concentration and transport properties. Here we systematically study, in the IXZO series, the role of X = Ga(3+) versus the progression X = Sc(3+) → Y(3+) → La(3+), having similar chemical characteristics but increasing ionic radii. IXZO films are prepared from solution over broad composition ranges for the first time via low-temperature combustion synthesis. The films are characterized via thermal analysis of the precursor solutions, grazing incidence angle X-ray diffraction (GIAXRD), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy (STEM) with high angle annular dark field (HAADF) imaging. Excellent thin-film transistor (TFT) performance is achieved for all X, with optimal compositions after 300 °C processing exhibiting electron mobilities of 5.4, 2.6, 2.4, and 1.8 cm(2) V(-1) s(-1) for Ga(3+), Sc(3+), Y(3+), and La(3+), respectively, and with I(on)/I(off) = 10(7)-10(8). Analysis of the IXZO TFT positive bias stress response shows X = Ga(3+) to be superior with mobilities (μ) retaining >95% of the prestress values and threshold voltage shifts (ΔV(T)) of lattice formation. We conclude that the metal oxide lattice formation enthalpy (ΔH(L)) and metal ionic radius are the best predictors of IXZO oxygen getter efficacy.

  18. Effect of dissolved oxygen on nitrate removal using polycaprolactone as an organic carbon source and biofilm carrier in fixed-film denitrifying reactors.

    Science.gov (United States)

    Luo, Guozhi; Xu, Guimei; Gao, Jinfang; Tan, Hongxin

    2016-05-01

    Nitrate-nitrogen (NO3(-)-N) always accumulates in commercial recirculating aquaculture systems (RASs) with aerobic nitrification units. The ability to reduce NO3(-)-N consistently and confidently could help RASs to become more sustainable. The rich dissolved oxygen (DO) content and sensitive organisms stocked in RASs increase the difficulty of denitrifying technology. A denitrifying process using biologically degradable polymers as an organic carbon source and biofilm carrier was proposed because of its space-efficient nature and strong ability to remove NO3(-)-N from RASs. The effect of dissolved oxygen (DO) levels on heterotrophic denitrification in fixed-film reactors filled with polycaprolactone (PCL) was explored in the current experiment. DO conditions in the influent of the denitrifying reactors were set up as follows: the anoxic treatment group (Group A, average DO concentration of 0.28±0.05mg/L), the low-oxygen treatment DO group (Group B, average DO concentration of 2.50±0.24mg/L) and the aerated treatment group (Group C, average DO concentration of 5.63±0.57mg/L). Feeding with 200mg/L of NO3(-)-N, the NO3(-)-N removal rates were 1.53, 1.60 and 1.42kg/m(3) PCL/day in Groups A, B and C, respectively. No significant difference in NO3(-)-N removal rates was observed among the three treatments. It was concluded that the inhibitory effects of DO concentrations lower than 6mg/L on heterotrophic denitrification in the fixed-film reactors filled with PCL can be mitigated. PMID:27155419

  19. Effects of Support on the Performance of NiO-Based Oxygen Carriers Effets du support sur les performances de matériaux transporteurs d’oxygène à base d’oxyde de nickel

    Directory of Open Access Journals (Sweden)

    Baek J.-I.

    2011-05-01

    Full Text Available The performance of an oxygen carrier for Chemical Looping Combustion varies with the support material used. NiO oxygen carriers were prepared using 60 or 70 wt% NiO and different raw support materials (γ-Al2O3, pseudoboehmite, α-Al2O3, γ-Al2O3 mixed with MgO, hydrotalcite, MgAl2O4, and γ-Al2O3 with added graphite by the mechanical mixing method. Reactivity tests were conducted using a thermogravimetric analyzer (TGA at 950˚C. The oxygen carriers prepared using γ-Al2O3, γ-Al2O3 mixed with a small amount of MgO, hydrotalcite, and MgAl2O4 showed high oxygen transfer capacity, high oxygen utilization, and a high oxygen transfer rate. Graphite addition to γ-Al2O3 did not increase the surface area or reactivity. The use of pseudoboehmite as a support led to a significant decrease in oxygen transfer capacity and severe agglomeration of the oxygen carriers during the redox reaction. The increase in MgO content in the raw support materials decreased the reduction reactivity. The oxygen carriers prepared with α-Al2O3 showed less oxygen transfer capacity than the other oxygen carriers. The differences in the reactivity according to the support type were explained by the relative strength of NiO-support interaction obtained from the temperature-programmed reduction analysis. The reactivity test results in this work indicate that γ-Al2O3 and hydrotalcite could be desirable raw support materials to prepare highly reactive NiO oxygen carriers with high NiO content. Les performances des materiaux transporteurs d’oxygene varient en fonction du support utilise dans le procede de combustion en boucle chimique. Differents materiaux a base d’oxyde de Nickel ont ete synthetises avec des concentrations elevees en NiO, comprises entre 60 et 70 %, sur differents supports (γ-Al2O3, pseudobohemite, α-Al2O3, γ-Al2O3 melangee avec MgO, hydrotalcite, MgAl2O4 et γ-Al2O3 additivees avec du graphite par melange mecanique. Des tests de reactivite ont ete

  20. Thermoluminescence (TL) properties and x-ray diffraction (XRD) analysis of high purity CaSO4:Dy TL material

    International Nuclear Information System (INIS)

    This paper presents the characterization and TL properties of dysprosium (Dy) doped calcium sulfate (CaSO4) TL material produced by co-precipitation technique with 0.5mol% concentration of dopant. The morphology of the produced TL material was studied using scanning electron microscope (SEM) and the micrograph shows that rectangular parallelepiped shaped crystal with the average of 150 μm in length were produced. The crystallinity of the produced powder was studied using x-ray powder diffraction (XRD). The XRD spectra show that the TL material produced is high purity anhydrite CaSO4 with average crystallite size of 74 nm with orthorhombic crystal system. The TL behavior of produced CaSO4:Dy was studied using a TLD reader after exposure to gamma ray by Co60 source with the doses of 1,5 and 10 Gy. The glow curve shows linear response with glow peak around 230°C which is desired development in the field of radiation dosimetry

  1. Chemical Looping Pilot Plant Results Using a Nickel-Based Oxygen Carrier; Resultats de l'experimentation sur un pilote operant en boucle chimique avec un materiau transporteur d'oxygene a base de nickel

    Energy Technology Data Exchange (ETDEWEB)

    Proll, T.; Kolbitsch, P.; Bolhar-Nordenkampf, J.; Hofbauer, H. [Vienna University of Technology, Institute of Chemical Engineering, Getreidemarkt 9/166, Vienna 1060 (Austria)

    2011-03-15

    A chemical looping pilot plant was designed, built and operated with a design fuel power of 120 kW (lower heating value, natural gas). The system consists of two Circulating Fluidized Bed (CFB) reactors. Operating results are presented and evaluated for a highly reactive nickel-based oxygen carrier, total system inventory 65 kg. The performance in fuel conversion achieved is in the range of 99.8% (CH{sub 4} conversion) and 92% (CO{sub 2} yield). In chemical looping reforming operation, it can be reported that thermodynamic equilibrium is reached in the fuel reactor and that all oxygen is absorbed in the air reactor as soon as the global stoichiometric air/fuel ratio is below 1 and the air reactor temperature is 900 C or more. Even though pure natural gas (98.6 vol.% CH{sub 4}) without steam addition was fed to the fuel reactor, no carbon formation has been found as long as the global stoichiometric air/fuel ratio was larger than 0.4. Based on the experimental findings and on the general state of the art, it is concluded that niche applications such as industrial steam generation from natural gas or CO{sub 2}-ready coupled production of H{sub 2} and N{sub 2} can be interesting pathways for immediate scale-up of the technology. (authors)

  2. Hydrogen and syngas production from two-step steam reforming of methane over CeO2-Fe2O3 oxygen carrier

    Institute of Scientific and Technical Information of China (English)

    ZHU

    2010-01-01

    Two-step steam reforming of methane(SRM)is a novel chemical looping process towards the production of pure hydrogen and syngas(synthesis gas),consisting ofa syngas production step and a water-splitting step.Renewable energy can be used to drive this process for hydrogen production,especially solar energy.CeO2-Fe2O3 complex oxide oxygen carrier was prepared by the impregnation method and characterized by means of X-ray diffractometer(XRD),Raman spectroscopy(Raman)and hydrogen programmed reduction(H2-TPR).CH4temperature programmed and isothermal reactions were adopted to test syngas production reactivity,and water splitting reaction was employed to investigate water-splitting activity.Moreover,two-step SRM performance was evaluated by a successive redox cycle.The results showed that CO-uncontaminated H2 and highly selective syngas(with H2/CO ratio close to 2)could be respectively obtained from two steps,and CeFeO3 formation was found in the first redox cycle and proved to be enhanced by the redox treatment.After 10 successive cycles,obvious CeFeO3 phase was detected,which may be responsible for favorable successive redox cycle performances.

  3. Hydration of calcium sulfate hemihydrate (CaSO 4· {1}/{2}H 2O) into gypsum (CaSO 4·2H 2O). The influence of the sodium poly(acrylate)/surface interaction and molecular weight

    Science.gov (United States)

    Boisvert, Jean-Philippe; Domenech, Marc; Foissy, Alain; Persello, Jacques; Mutin, Jean-Claude

    2000-12-01

    The retarding influence of sodium poly(acrylate) (PANa) on the hydration of calcium sulfate hemihydrate (CaSO 4· {1}/{2}H 2O) was investigated. This study reports the influence of sodium poly(acrylate) on hemihydrate dissolution, on homogenous and heterogeneous gypsum (CaSO 4·2H 2O) nucleation as well as on gypsum growth. It is shown that adsorption of PANa does not hinder the dissolution of hemihydrate in the present experimental conditions. The specific interaction of PANa with gypsum can explain the oriented growth of gypsum crystal. The gypsum growth is slowed down but cannot be blocked by the adsorption of PANa. On the other hand, PANa can block the heterogeneous and homogenous gypsum nucleation. As soon as a critical surface density of PANa onto the hemihydrate surface is reached, the heterogeneous gypsum nucleation is prevented and hemihydrate hydration is indefinitely blocked. The interaction between PANa and the hemihydrate surface is of prime importance to control hydration. Also, the influence of the molecular weight of PANa on homogenous nucleation has been investigated. The precipitation of calcium polyacrylate can explain the differences between the two molecular weights used (2100 and 20 000). This work leads to the conclusion that heterogeneous nucleation is the key process that controls hydration of a system in which hemihydrate dissolution, gypsum nucleation and growth are all occurring at the same time in a continuous manner.

  4. Operational experience with a system of coupled fluidized beds for chemical looping combustion of solid fuels using ilmenite as oxygen carrier

    International Nuclear Information System (INIS)

    Highlights: • Successful operation of a coupled fluidized bed system for CLC of coal. • Two-stage design worked well, i.e. the 2nd stage has an significant effect on fuel conversion. • Solids circulation rates were determined. • High carbon capture rate (ηCC > 96%), which might be attributed to the very fine coal. - Abstract: A system of coupled fluidized beds for chemical looping combustion of solid fuels was successfully commissioned. The facility has a rated thermal power of 25 kW and consists of a circulating fluidized bed coupled with a two-stage bubbling fluidized bed. The two-stage bubbling fluidized bed is the fuel reactor and the riser of the circulating fluidized bed is the air reactor. In the experiments Australian ilmenite with a particle size in the range of 100–400 μm was used as the oxygen carrier. The solid fuel was lignite dust with more than 70% of the mass having a particle size smaller than 150 μm. The influence of the operational parameters, i.e. reactor temperature, coal feed rate and composition of the fuel reactor feed gas on the operational behaviour of the system was investigated. The two-stage fuel reactor performed well and CO2-concentrations in the dry fuel reactor off-gas of above 90 vol.% were achieved. The reason for the appearance of unconverted combustible gases in the fuel reactor off-gas needs further investigation. Solids circulation rates based on the riser cross-section were determined under hot operating conditions and turned out to be between 56 and 70 kg/m2 s. The carbon slip to the air reactor was small in all tests: only 1.5–6.5 wt.% of the fixed carbon introduced with the coal were oxidized in the air reactor

  5. Optimizing a method to obtain CaSO4 activated with Dy for use in thermoluminescent dosimetry

    International Nuclear Information System (INIS)

    Results obtained from experiments in optimizing the variables in the preparation of CaSO4 activated with dysprosium, as phosphors to be used as low dose TL dosemeters for routine radiological protection are presented. The technique used combined those of T. Yamashita and of K. Becker. Heating 8.6 gm of CaSO4.H2O with 0.1 mol % of Dy2O3 in 115 ml of concentrated H2SO4 to 2850C to completely evaporate the acid and placing the obtained crystals in a 6000C oven for one hour gave a TL dosimeter with a sensitivity sufficient to measure 5 mR of 60Co gamma radiation and show a lineal response with this radiation in a 5 mR-5x104R interval. Fading, which appeared in the phosphor only after three weeks, was in the fourth week 4.0% and in the eighth week 6.2% with a σ=+-2.1%. The quality of the phosphor obtained and its ease of reproducibility deserves note. (author)

  6. Measurement of the dose by dispersed radiation in a lineal accelerator using thermoluminescent dosimeters of CaSO4:Dy

    International Nuclear Information System (INIS)

    The thermoluminescence (Tl) is based on the principle of the luminescent in a material when is heated below their incandescence temperature. Is a technique very used in dosimetry that is based on the property that have most of the crystalline materials regarding the storage of the energy that they absorb when are exposed to the ionizing radiations. When this material has been irradiated previously, the radioactive energy that contains is liberated in form of light. In general, the principles that govern the thermoluminescence are in essence the same of those responsible for all the luminescent processes and, this way, the thermoluminescence is one of the processes that are part of the luminescence phenomenon. For this work, the dispersed radiation was measured in the therapy area of the lineal accelerator of medical use type Elekta, using thermoluminescent dosimeters of CaSO4:Dy + Ptfe developed and elaborated in the Universidad Autonoma Metropolitana, Unidad Iztapalapa. With the dosimeters already characterized and calibrated, we proceeded to measure the dispersed radiation being a patient in treatment. The results showed values for the dispersed radiation the order of a third of the dose received by the patient on the treatment table at 30 cm of the direct beam and the order of a hundredth in the control area (4 m of the direct beam, approximately). The conclusion is that the thermoluminescent dosimeters of CaSO4: Dy + Ptfe are appropriate to measure dispersed radiation dose in radiotherapy. (author)

  7. Dosimetric properties of a new high sensitive CaSO4:Dy thermostimulated luminescent phosphor and teflon discs

    International Nuclear Information System (INIS)

    This paper describes the dosimetric properties of a high sensitive CaSO4:Dy thermostimulated luminescence (TLD) phosphor (called N) and Teflon discs supplied by M/s Fluorokraft. The average grain size of this phosphor is very low (10 to 20 μm). Scanning electron microscope photograph reveals needle shaped crystals while that of CaSO4:Dy prepared by the presently used recrystallization technique (called P) is featureless. The TSL sensitivity of N (4 Gy, P exhibits drastic glow curve changes at dose levels ≥ 10 Gy. As a result, the supralinearity of N > 10 Gy is considerably less than that of P. The TSL and photoluminescent (PL) emission spectra show the characteristic 480 and 570 nm Dy3+ lines in both the samples but their relative intensity ratio seem to be sample dependent. In contrast to TSL, the PL intensity of N is just 1/5th that of P. Electron spin resonance and x-ray diffraction studies also show differences between the two samples. (author)

  8. Thermoluminescent characteristics of LiF:Mg,Cu,P and CaSO$_4$:Dy for low dose measurement

    CERN Document Server

    Fernández, S Del Sol; Mendoza, J Guzmán; Sánchez-Guzmán, D; Rodríguez, G Ramírez; Gaona, E; Montalvo, T Rivera

    2016-01-01

    Thermoluminescence (TL) characteristics for LiF:Mg,Cu,P, and CaSO$_4$:Dy under the homogeneous field of X-ray beams of diagnostic irradiation and its verification using thermoluminescence dosimetry is presented. The irradiation were performed utilizing a conventional X-ray equipment installed at the Hospital Ju\\'arez Norte of M\\'exico. Different thermoluminescence characteristics of two material were studied, such as batch homogeneity, glow curve, linearity, detection threshold, reproducibility, relative sensitivity and fading. Materials were calibrated in terms of absorbed dose to the standard calibration distance and they were positioned in a generic phantom. The dose analysis, verification and comparison with the measurements obtained by the TLD-100 were performed. Results indicate that the dosimetric peak appears at 202$^o$C and 277.5$^o$C for LiF:Mg,Cu,P and CaSO$_4$:Dy, respectively. TL response as a function of X-ray dose showed a linearity behavior in the very low dose range for all materials. However...

  9. Heat capacities and entropies from 8 to 1000 K of langbeinite (K2Mg2(SO4)3), anhydrite (CaSO4) and of gypsum (CaSO4·2H2O)

    Science.gov (United States)

    Robie, Richard A.; Russell-Robinson, Susan; Hemingway, Bruce S.

    1989-01-01

    Heat capacities of K2Mg2(SO4)3 (langbeinite) and CaSO4 (anhydrite) were measured from approximately 8 to 1000 K by combined adiabatic shield calorimetry (8-365 K) and differential scanning calorimetry (350-1000 K). Heat capacities were also measured on natural crystals of gypsum (CaSO4 · 2H2O) between 8.1 and 323.5 K. The molar entropies at 298.15 K, Smo(298.15 K), are 378.8 ± 0.6, 107.4 ± 0.2 and 193.8 ± 0.3 J K−1 mol−1 for langbeinite, anhydrite and gypsum, respectively. The heat capacity in J K−1 mol−1 of langbeinite can be represented by the equation Cp,mo(K2Mg2(SO4)3T) = 535.9 + 0.11011T-1.0200 × 106/T2-4.909 × 10−5T2 -4040.2/T0.5 between 300 and 1000 K with an average deviation of ± 0.4%. For anhydrite the heat capacity between 300 and 1000 K is given by Cp,mo(CaSO4,T) = 372.8 - 0.1574 T +1.695 × 106/T2 + 7.993 × 10−5T2 - 4330.8/T0.5 with an average deviation of ±0.4%.

  10. Simulation Experiments on the Reaction of CH4-CaSO4 and Its Carbon Kinetic Isotope Fractionation

    Institute of Scientific and Technical Information of China (English)

    YueChangtao; LiShuyuan; DingKangle; ZhongNingning

    2005-01-01

    Thermochemical sulfate reduction (TSR) in geological deposits can account for the accumulation of H,S in deep sour gas reservoirs. In this paper, thermal simulation experiments on the reaction of CH4-CaSO4 were carried out using an autoclave at high temperatures and high pressures. The products were characterized with analytical methods including carbon isotope analysis. It is found that the reaction can proceed to produce H2S, H2O and CaCO3 as the main products. Based on the experimental results, the carbon kinetic isotope fractionation was investigated, and the value of Ki(kinetic isotope effect) was calculated. The results obtained in this paper can provide useful information to explain the occurrence of H2S in deep carbonate gas reservoirs.

  11. THE THERMOLUMINESCENCE EFFICIENCY OF Li(2)B(4)O(7):Cu AND OF CaSO(4):Tm FOR PHOTONS

    CERN Document Server

    Otto, T; Gindraux, L

    2011-01-01

    The intrinsic thermoluminescence (TL) efficiency of a TL detector relates the absorbed dose in the detector material to the light yield observed upon evaluation. Knowledge of the TL efficiency is of interest when performing numerical simulations of detector response, where only absorbed dose can be predicted. Here, the experimental determination of TL efficiency for calcium sulphate (CaSO(4):Tm) and lithium borate (Li(2)B(4)O(7):Cu) is reported. These materials are widely used in Panasonic dosemeter badges. The results of the study are in agreement with predictions from track structure theory and microdosimetry, relating an enhanced light yield at low X-ray energies to supralinear behaviour of the TL phosphor.

  12. Testing of CaSO-4:Dy in teflon discs as a thermoluminescent dosimetry material for personal monitoring of uranium mine and mill workers

    International Nuclear Information System (INIS)

    Some studies of the spectroscopic and thermoluminescent properties of CaSO4:Dy are discussed. Measurements were also made in the field. Exposures measured using TLD, film and spot monitoring were in agreement, and these observations, together with measurements made at various heights above the ore stockpile have shown that CaSO4:Dy in teflon discs, shielded by 2mm of copper, give a reliable measure of the exposure at the appropriate position on the wearer's body. This exposure may then be converted into the dose equivalent for the whole body

  13. O2.04TREATMENT WITH OMX-4.80, A TUMOR-PENETRATING TUNABLE OXYGEN CARRIER, REDUCES TUMOR HYPOXIA AND DRAMATICALLY ENHANCES RADIATION THERAPY IN INTRACRANIAL MODELS OF GLIOBLASTOMA

    OpenAIRE

    Krtolica, A; Le Moan, N.; Serwer, L.; Yoshida, Y.; Ozawa, T; Butowski, N.; James, D; Cary, S.

    2014-01-01

    We have developed OMX-4.80, a tunable oxygen carrier from the H-NOX protein family, that preferentially accumulates in tumor tissue, reduces hypoxia and enhances radiotherapy (RT). Tumor hypoxia is associated with poor patient outcomes in multiple solid tumors including glioblastoma (GB) and is thought to be a major contributor to poor cancer responses to chemo and radiation therapy. Here, we show that OMX-4.80 administered i.v. into the tail vein of mice bearing orthotopic GB passes the bloo...

  14. Dosimetric intercomparison in Cobalt 60 unities using TLD-100 crystals and CaSO4: Dy + Ptfe

    International Nuclear Information System (INIS)

    The purpose of this work is to design and construct a phantom in basis of thermoplastic polymer of methyl methacrylate that is reutilizable and which allows to do an analysis of the absorbed doses in thermoluminescent crystals (Tl) exposed to cobalt 60 to establish the dosimetric intercomparison in cobalt units which allows to do the follow-up of the Quality assurance programs, standardization of calibration procedures, dosimetry and TLD post intercomparison in radiotherapy. This work allows also prove new thermoluminescent materials of national manufacture developed by Juan Azorin and collaborators as the CaSO4: Dy + Ptfe. This is a first study which is realized in Mexico with the system crystal-phantom for aims to intercomparison in cobalt 60 units. In this work participate eight unities of cobalt 60 of different trades belonging at four radiotherapy centers. The results of the dose intercomparison of the eight unities of cobalt 60 were in the range 0.95-1.13, taking in account that the values between 0.95 and 1.05 were considered acceptable in terms of the requirements by the standing legislation. (Author)

  15. Radionuclide carriers

    International Nuclear Information System (INIS)

    A new carrier for radionuclide technetium 99m has been prepared for scintiscanning purposes. The new preparate consists of physiologically acceptable water-insoluble Tcsup(99m)-carrier containing from 0.2 to 0.8 weight percent of stannic ion as reductor, bound to an anionic starch derivative with about 1-20% of phosphate substituents. (EG)

  16. Anglesite (PbSO4) epitactic overgrowths and substrate-induced twinning on anhydrite (CaSO4) cleavage surfaces

    Science.gov (United States)

    Morales, Juan; Astilleros, José Manuel; Fernández-Díaz, Lurdes; Álvarez-Lloret, Pedro; Jiménez, Amalia

    2013-10-01

    The dissolution-precipitation reactions occurring on mineral surfaces are considered an effective means to remove high amounts of dissolved toxic metals from fluid phases by precipitation of a new solid in whose structures the pollutant is immobilized. However, for these reactions to be efficient a continuous communication between the fluid and mineral phases is required. This communication can be significantly hindered when the new solid phase forms a continuous, homogeneous layer on the mineral substrate. The formation of such a layer is more likely to occur when epitactic relationships exist between the newly formed phase and the mineral substrate. Dissolved lead can be removed by interaction of the Pb-bearing aqueous solution with anhydrite (CaSO4) leading to the formation of anglesite (PbSO4). Here, the relationship between anglesite crystals and an anhydrite substrate is investigated. The three main anhydrite cleavage surfaces, (100), (010), and (001) are considered. A high density of oriented anglesite crystals growing with their (210) plane parallel to the substrate was observed on (001)Anh. The density of oriented anglesite was, however, significantly lower on (100)Anh and almost negligible on (010)Anh. Anglesite grew with its (001) plane parallel to the substrate on (100)Anh, but no evident epitactic relationship was found with (010)Anh. Differences in anglesite crystal density are explained on the grounds of structural similarities and the goodness of anglesite-anhydrite matching through the interface. Both on anhydrite (100) and (001) anglesite crystals show at least two specific orientations, which relate to each other through symmetry operators present in the substrate. The coalescence of differently oriented anglesite crystals leads to the formation of twins. This twinning phenomenon is designated as substrate-induced twinning, since the twinning law is determined by the substrate symmetry. In the particular case of anglesite growing on anhydrite (100) two different orientations have been observed, related each other through (210)Ang which act as twin plane.

  17. Aircraft Carriers

    DEFF Research Database (Denmark)

    Nødskov, Kim; Kværnø, Ole

    in Asia and will balance the carrier acquisitions of the United States, the United Kingdom, Russia and India. China’s current military strategy is predominantly defensive, its offensive elements being mainly focused on Taiwan. If China decides to acquire a large carrier with offensive capabilities......, then the country will also acquire the capability to project military power into the region beyond Taiwan, which it does not possess today. In this way, China will have the military capability to permit a change of strategy from the mainly defensive, mainland, Taiwan-based strategy to a more assertive strategy...... to acquire a carrier, they can either buy one or build it themselves. The easiest way would be to buy a carrier, and if that is the chosen option, then Russia would be the most likely country to build it. Technologically, it will be a major challenge for them to build one themselves and it is likely...

  18. Importância dos carreadores de oxigênio livre de células Oxygen carriers free of cells in transfusion medicine

    Directory of Open Access Journals (Sweden)

    Marcia Cristina Z. Novaretti

    2007-12-01

    Full Text Available Os procedimentos necessários para redução de efeitos adversos associados à transfusão de sangue, em especial aqueles decorrentes da transmissão de agentes infecciosos e da aloimunização leucócito-mediada têm impacto nos custos de produção de hemocomponentes. Paralelamente, as necessidades transfusionais têm aumentado globalmente, ficando evidente a necessidade de um substituto seguro e amplamente disponível para o sangue, chamado de sangue artificial ou de substituto do sangue. Visto que o seu desenvolvimento tem se concentrado na função de carrear oxigênio aos tecidos, daí utilizarmos, nesse texto, a denominação "Carreadores de oxigênio livre de células". Atualmente, dois tipos de carreadores de oxigênio livre de células têm sido testados: as soluções de hemoglobina modificadas (de origem humana ou bovina e os perfluorocarbonos (PFCs. Entretanto, esses produtos não são isentos de efeitos adversos e um grande número de pesquisas clínicas está em andamento para testar sua eficácia e segurança. O maior conhecimento desses carreadores de oxigênio livre de células e seus mecanismos de ação permitiu que aplicações outras, até mesmo não clínicas, estivessem em teste com as novas gerações desses produtos, expandindo assim as fronteiras da medicina transfusional.The procedures needed to reduce transfusion-associated adverse effects, especially those related to transfusion-transmitted diseases and leukocyte-mediated alloimmunization, have a great impact on the production cost of blood components. Additionally, blood transfusion has increased worldwide making the need for a safe substitute for blood evident. These products have been named artificial blood or blood substitutes. Based on the fact that their focus has been oxygen delivery to tissues, "free oxygen carrying cells" is more appropriate. Two major groups of free oxygen carring cells have been tested: modified hemoglobin solutions (bovine or human and

  19. Living with Oxygen Therapy

    Science.gov (United States)

    ... transportation carrier (for example, the airline or bus company). If you need oxygen while traveling, plan in ... NEXT >> Updated: February 24, 2012 Twitter Facebook YouTube Google+ SITE INDEX ACCESSIBILITY PRIVACY STATEMENT FOIA OIG CONTACT ...

  20. Thermoluminescent response to thermal neutrons of mixture of CaSO4: Tm and non-luminous 6LiF

    International Nuclear Information System (INIS)

    Thermoluminescent property of the mixture of CaSO4: Tm powder and non-luminous 6LiF powder was studied with a view to developing a personnel monitor for thermal neutrons. Its thermoluminescent response to thermal neutrons as a function of the particle size or the mixing ratio of both powders was investigated theoretically and experimentally. The phosphor sample, which was prepared according to the most favorable conditions that the particle size of both powders was between 100 -- 150 μm and the mixing weight ratio of CaSO4: Tm to 6LiF was 1 : 1, was found to have the following dosimetric properties. (1) The thermoluminescence output is linear against neutron dose in a dose range from 10 μrem up to 6 rem. (2) The thermoluminescent efficiency remains constant even after 5,000 repetitions of exposure-reading-annealing procedure. (3) A thermal neutron dose of 1 mrem can be determined with a standard deviation of 5.2% even under a γ-ray background of 10 mR. (auth.)

  1. Study of Thermodynamics and Kinetics of CH4-CaSO4 and H2S-Fe2O3 Systems

    Institute of Scientific and Technical Information of China (English)

    岳长涛; 李术元; 丁康乐; 钟宁宁

    2003-01-01

    The destruction of hydrocarbon in deep carbonate diagenetic environment is one of problems on the formation of oil and gas. Organic-inorganic reactions in the process of TSR(Thermochemical Sulfate Reduction) are the main reason to make disappearance of the hydrocarbons. The work in this field has often been the subject of much research work in recent years. In this paper, the thermodynamics of CH4-CaSO4 and H2S-Fe2O3 systems is discussed to investigate the possibility of reactions. It is found that these two reactions can proceed spontaneously.Increasing temperature is favorite for CH4-CaSO4 system but disfavorite for H2S-Fe2O3 system. Thermal simulation experiments were carried out using autoclave at high temperature and high pressure. The properties of the products were characterized by microcoulometry, FT-IR and XRD methods. On the basis of the experimental data, a reaction kinetic model is developed and kinetic parameters are determined.

  2. Preconception Carrier Screening

    Science.gov (United States)

    ... Events Advocacy For Patients About ACOG Preconception Carrier Screening Home For Patients Search FAQs Preconception Carrier Screening ... Screening FAQ179, August 2012 PDF Format Preconception Carrier Screening Pregnancy What is preconception carrier screening? What is ...

  3. 生物质灰对铁矿石载氧体性能的影响%Effect of biomass ash on performance of iron ore as oxygen carrier in chemical looping combustion

    Institute of Scientific and Technical Information of China (English)

    周玉飞; 沈来宏; 顾海明; 牛欣

    2015-01-01

    在小型固定床上以铁矿石为载氧体、CO为燃料,进行了化学链燃烧试验。通过在铁矿石中加入生物质灰,探讨了生物质灰的种类(玉米秆灰、油菜秆灰和稻草灰)、灰的添加量(5%~20%)及灰中碱金属对铁矿石载氧体反应活性的影响。试验结果表明:生物质灰中无机组分不同,对铁矿石载氧体反应活性的影响也不同。由于玉米秆灰和油菜秆灰中碱金属K含量较高,高温下K以气态形式迁移到铁矿石表面,生成了K3 FeO2,从而提高了铁矿石的还原反应活性。稻草灰中Si含量很高,高温下碱金属K及FeO与铁矿石反应,生成低熔点共晶体,加剧了铁矿石表面的烧结,减少了气固反应的接触面积,导致CO总转化率急剧下降。%Experiment on chemical looping combustion was conducted in a fixed bed reactor with iron ore as oxygen carrier and CO as fuel.The effect of biomass ash addition on the performance of the iron ore oxygen carrier was investigated.Several key factors were discussed, including the bio-mass ash type (corn stalk ash, rape stalk ash, straw ash), the ash ratio (5%to 20%) and the alkali metal in the ash.The results indicate that the effect of the biomass ash on the reactivity of iron ore depends on the chemical composition of the ash.The alkali metal K abundant in corn ash and rape ash is released in gaseous state and captured by iron ore through complicated reactions, forming K3 FeO2 which enhances the reduction reactivity of the iron ore.However, the high content of Si in the straw ash leads to a reaction of Si with K and FeO under high temperature to form low melting point compounds which causes serious sintering on the surface of the iron ore.The decrease of con-tact surface causes the decrease of the total CO conversion.

  4. Nano-structured hemoglobin-based oxygen carriers: from properties, methemoglobin suppression to long circulation in blood%血红蛋白基纳米氧载体:结构特点、高铁含量控制及血循环中持久存在

    Institute of Scientific and Technical Information of China (English)

    袁媛; 章晓兰; 刘昌胜

    2011-01-01

    Due to the continuously insufficient supply and the disadvantages associated with the donated blood, artificial blood substitute has received extensive attentions throughout the world in recent years.Nano-structured hemoglobin-based oxygen carriers (NHOCs), in particular the liposome-encapsulated hemoglobin (LEH) and hemoglobin-based polymeric nanoparticles (HbPNPs), which combine the nanotechnology with the traditional cellular oxygen carriers, have shown great potential applications in blood transfusion, thrombus and cancer therapy as well.The present article firstly reports on the current status of the synthesis, properties, clinical trial and application of the LEH and HbPNPs.And then, attentions are devoted to highlight the main challenges and the proposed strategies of the NHOCs with the respect of suppression of the methemoglobin formation and prolonging the blood circulation time.These results make us confident in advancing further development of NHOCs, with the expectation of their eventual commercialization.

  5. O2.04TREATMENT WITH OMX-4.80, A TUMOR-PENETRATING TUNABLE OXYGEN CARRIER, REDUCES TUMOR HYPOXIA AND DRAMATICALLY ENHANCES RADIATION THERAPY IN INTRACRANIAL MODELS OF GLIOBLASTOMA

    Science.gov (United States)

    Krtolica, A.; Le Moan, N.; Serwer, L.; Yoshida, Y.; Ozawa, T.; Butowski, N.; James, D.; Cary, S.

    2014-01-01

    We have developed OMX-4.80, a tunable oxygen carrier from the H-NOX protein family, that preferentially accumulates in tumor tissue, reduces hypoxia and enhances radiotherapy (RT). Tumor hypoxia is associated with poor patient outcomes in multiple solid tumors including glioblastoma (GB) and is thought to be a major contributor to poor cancer responses to chemo and radiation therapy. Here, we show that OMX-4.80 administered i.v. into the tail vein of mice bearing orthotopic GB passes the blood-tumor barrier, penetrates deep into intracranial tumors, and significantly reduces tumor hypoxia in a dose-dependent manner. Hypoxia reduction is demonstrated by a significant decrease in levels of hypoxia inducible factor, HIF1α, and the external hypoxia marker pimonidazole as assessed by IHC and image analysis. Furthermore, hypoxia before and after treatment is compared in the individual tumors by concurrent immunostaining of tumors with a long-term hypoxia marker, Glut1, and short-lived HIF-1α. These data reveal >50% reduction in hypoxic tumor area after OMX-4.80 treatment confirming the effectiveness of OMX-4.80 in reducing hypoxia in individual tumors. When OMX-4.80 treatment was coupled with a single high dose of RT, we observed a 2.7-fold increase in tumor growth delay and 2.9-fold longer survival (p < 0.05, by logrank). Toxicology studies in rodents and dogs with single and multiple supratherapeutic doses of OMX-4.80 revealed a good safety profile affirming its suitability for clinical development. In conclusion, our results indicate that OMX-4.80 is an effective and promising RT enhancer that warrants clinical development in GB patients.

  6. 批量制备Fe2O3/Al2O3氧载体及褐煤化学链燃烧实验研究%Batch Preparation of Fe2O3/Al2O3 Oxygen Carriers for Chemical Looping Combustion of Lignite

    Institute of Scientific and Technical Information of China (English)

    郭磊; 赵海波; 马琎晨; 梅道锋; 方彦飞; 郑楚光

    2013-01-01

    Freeze granulation,spray drying,impregnation and mechanical mixing methods were adopted to prepare Fe2O3/Al2O3 oxygen carriers.To identify the appropriate technologies for batch preparation of the oxygen carriers,the four preparation methods were compared in terms of yield rate,preparation period,physical and chemical characteristics and performance in chemical looping combustion (CLC) of lignite.The experimental results show that freeze granulation has the highest yield rate of carrier with the best mechanical strength.CLC tests of lignite demonstrate that the oxygen carriers prepared by freeze granulation and spray drying bring the highest carbon conversion rate,followed by impregnation and mechanical mixing; and the oxygen carriers prepared by the first two methods have higher chemical reactivity and more stable performance.In the four reduction processes with oxygen carriers prepared by all the four preparation methods,CO2 capture efficiencies exceed 88%; the yield rate of CO2 increases with the rate of carbon conversion,finally approaching 100%; and the combustion efficiencies are above 90%.These indicate that the oxygen carriers prepared by the four methods all have good performances for CO2 capture and high utilization degree of the combustible components.Freeze granulation and spray drying methods can be considered preferentially for batch preparation of oxygen carriers for the CLC of lignite.%采用冷冻成粒法、喷雾干燥法、浸渍法、机械混合法批量制备了Fe2O3/Al2O3氧载体,从氧载体产率、制备周期、物理化学表征、煤化学链燃烧中氧载体性能等角度比较各种批量制备方法,确定合适的批量制备技术.实验结果表明,冷冻成粒法的氧载体产率较高,机械性能最优;与褐煤的化学链燃烧实验中,喷雾干燥法和冷冻成粒法制备的氧载体导致碳转化速率较快,然后依次为浸渍法和机械混合法;且前两种方法制备的氧载体的循环稳定性

  7. What Is Carrier Screening?

    Science.gov (United States)

    ... you want to learn. Search form Search Carrier screening You are here Home Testing & Services Testing for ... help you make the decision. What Is Carrier Screening? Carrier screening checks if a person is a " ...

  8. CaSO4溶液中表面处理对流动沸腾传热系数的影响%Effect of Surface Treatment on Flow Boiling Heat Transfer Coefficient in CaSO4 Containing Water

    Institute of Scientific and Technical Information of China (English)

    任晓光; 李铁凤; 赵起

    2006-01-01

    This paper reports the influence of heat transfer surface treatment on the formation of calcium sulphate deposit during flow boiling heat transfer. The surface of several test heaters was treated by surface modification techniques,such as dynamic mixing magnetron sputtering [DLC (diamond-like carbon), DLC-F (diamond-like carbon-fluorine) and AC (amorphous carbon)] and polishing to reduce surface energy. The results showed that heat transfer surface with low surface energy experienced significant reduction of formation of CaSO4 deposit. (1) Magnetron sputtering stainless steel heat transfer surface with DLC, DLC-F and plasma arc sputtering with AC did not change the surface roughness, but they reduced surface energy and improved heat transfer coefficient, so hindered CaSO4 deposit formation significantly. The DLC-F surface performed better than the DLC surface. (2) Surface energy played an important pole in improving heat transfer coefficient. The less the surface energy the more significant the heat transfer coefficient improved with other experimental conditions identical. (3) The polished surface improved the roughness of the heater, but owing to the high surface energy it was not better than the DLC-F surface for a long-term consideration on improving the heat transfer coefficient.

  9. Using Low-Cost Iron-Based Materials as Oxygen Carriers for Chemical Looping Combustion Utilisation de matériaux bon marché à base de fer comme transporteur d’oxygène dans la combustion en boucle chimique

    Directory of Open Access Journals (Sweden)

    Jerndal E.

    2011-03-01

    Full Text Available In chemical looping combustion with solid fuels, the oxygen-carrier lifetime is expected to be shorter than with gaseous fuels. Therefore, it is particularly important to use low-cost oxygen carriers in solid fuel applications. Apart from being cheap, these oxygen carriers should be able to convert the CO and H2 produced from the solid fuel gasification and be sufficiently hard to withstand fragmentation. Several low-cost iron-based materials displayed high conversion of syngas and high mechanical strength and can be used for further development of the technology. These materials include oxide scales from Sandvik and Scana and an iron ore from LKAB. All tested oxygen carriers showed higher gas conversion than a reference sample, the mineral ilmenite. Generally, softer oxygen carriers were more porous and appeared to have a higher reactivity towards syngas. When compared with ilmenite, the conversion of CO was higher for all oxygen carriers and the conversion of H2 was higher when tested for longer reduction times. The oxygen carrier Sandvik 2 displayed the highest conversion of syngas and was therefore selected for solid fuel experiments. The conversion rate of solid fuels was higher with Sandvik 2 than with the reference sample, ilmenite. Pour appliquer la combustion en boucle chimique à des charges solides, il est important d’utiliser des matériaux transporteurs d’oxygène bon marché. En effet, la durée de vie du transporteur d’oxygène risque d’être plus courte sur charge solide que sur charge gazeuse. Ces matériaux doivent également bien convertir le monoxyde de carbone et l’hydrogène résultant de la gasification, tout en étant suffisamment durs pour résister à la fragmentation. Plusieurs matériaux ont montré un potentiel de conversion élevé sur le gaz de synthèse ainsi qu’une résistance mécanique élevée, ce qui permet d’envisager leur utilisation lors des développements futurs de la technologie. Parmi ces

  10. Oxygen Therapy

    Science.gov (United States)

    Oxygen therapy is a treatment that provides you with extra oxygen. Oxygen is a gas that your body ... machine in your home. A different kind of oxygen therapy is called hyperbaric oxygen therapy. It uses oxygen ...

  11. Development of a technique for improving coefficient of variation of CaSO4:Dy teflon-based TLD personnel monitoring system in low-dose region.

    Science.gov (United States)

    Pradhan, S M; Sneha, C; Sahai, M K; Chougaonkar, M P; Babu, D A R

    2015-12-01

    In view of the importance of zero-dose background (null signal) in influencing the coefficient of variation in low-dose region, a technique for the estimation of the same from composite (gross) signal is developed for CaSO4:Dy-based personnel monitoring system being used in India. The technique is based on simple analysis of glow curves (GCs) of unexposed and exposed dosemeters, evolution of trend/model for the zero-dose curves, generation of simulation protocol for individual zero-dose curves, establishment of characteristics of GCs of exposed dosemeters and finally preparation of an algorithm to segregate the components from composite signal. The technique offers the separation of real-time background and gives superior results over other method of approximation of the background. The results also prove efficiency of the empirical trending and simulation protocol of background GCs. The proposed technique can be implemented in routine monitoring without any extra man hours and reader time.

  12. Development and evaluation of a new baDge/filter for thermoluminescent monitoring with CaSO4: Dy/PTFE

    International Nuclear Information System (INIS)

    Calcium Sulfate (CaSO4:Dy) phosphor Thermoluminescent Dosimeter (TLD) has been used by the Instituto de Pesquisas Energeticas e Nucleares (IPEN), SP, Brazil since 70's and 80's, due to important work of its researchers and collaborators. This phosphor advantages, beside the fact that it is produced by IPEN itself, begin to be more required and its disadvantages have became more apparent, in a global market more and more competitive. This phosphors was used primarily in environmental and area monitoring at IPEN facilities and in a few external institutions, once it presents more sensibility than other phosphors, like LiF:Mg. Its mainly disadvantage is a strong energetic dependence response to ionizing radiation, which must be corrected for its application in every radiation field. This phosphor has been used inside a badge which is an adaptation from photographic film badges used in the past. This badge permits a reasonable correction in the energetic dependence, only for orthogonal beam incidence. With the objective of improve the performance and reduce the energetic dependence on any incidence angle, reducing the dose measurement uncertainty too, this work presents a study on a new badge, with a new filter geometry, and its performance was compared to the actual dosimeter in use, with significant improve on results. Gamma irradiations of 60Co and x-rays of 25,1; 33; 37,3 and 82,1 keV, on incidence angles of 0 deg, 30 deg, 45 deg and 90 deg were done at facility conditions of IPEN. Semi-empirical computational simulation using finite differences in three dimensions were done. The results pointed out the best filter thickness and width for initiate the prototype production, in order to optimize the correction on energetic dependence on irradiation of photons of 33, 48, 118 and 1250 keV energies under many incidence angles. (author)

  13. Corrosion study on high power feeding of telecomunication copper cable in 5 wt.% CaSO4.2H2O solution

    Science.gov (United States)

    Shamsudin, Shaiful Rizam; Hashim, Nabihah; Ibrahim, Mohd Saiful Bahri; Rahman, Muhammad Sayuzi Abdul; Idrus, Muhammad Amin; Hassan, Mohd Rezadzudin; Abdullah, Wan Razli Wan

    2016-07-01

    The studies were carried out to find out the best powering scheme over the copper telephone line. It was expected that the application of the higher power feeding could increase the data transfer and capable of providing the customer's satisfaction. To realize the application of higher remote power feeding, the potential of corrosion problem on Cu cables was studied. The natural corrosion behaviour of copper cable in the 0.5% CaSO4.2H2O solution was studied in term of open circuit potential for 30 days. The corrosion behaviour of higher power feeding was studied by the immersion and the planned interval test to determine the corrosion rate as well as the effect of voltage magnitudes and the current scheme i.e. positive direct (DC+) and alternating current (AC) at about 0.40 ± 0.01 mA/ cm2 current density. In the immersion test, both DC+ and AC scheme showed the increasing of feeding voltage magnitude has increased the corrosion rate of Cu samples starting from 60 to 100 volts. It was then reduced at about 100 - 120 volts which may due to the passive and transpassive mechanism. The corrosion rate was slowly reduced further from 120 to 200 volts. Visually, the positively charged of Cu cable was seems susceptible to severe corrosion, while AC scheme exhibited a slight corrosion reaction on the surface. However, the planned interval test and XRD results showed the corrosion activity of the copper cable in the studied solution was a relatively slow process and considered not to be corroded as a partially protective scale of copper oxide formed on the surface.

  14. Facilitated oxygen transport in liquid membranes: review and new concepts

    NARCIS (Netherlands)

    Figoli, A.; Sager, W.F.C.; Mulder, M.H.V.

    2001-01-01

    In this paper, an overview is given on membranes with oxygen facilitated transport properties to enrich the oxygen content in air. Special emphasis is paid to recent developments of oxygen carrier systems and carrier containing membranes. Concepts leading to a structural evolution of supported liqui

  15. The optically stimulated luminescence (OSL) properties of LiF:Mg,Ti, Li2B4O7:Cu, CaSO4:Tm, and CaF2:Mn thermoluminescent (TL) materials

    International Nuclear Information System (INIS)

    This paper reports on an investigation into the optically stimulated luminescence (OSL) properties of several known thermoluminescent materials, namely LiF:Mg,Ti, Li2B4O7:Cu, CaSO4:Tm, and CaF2:Mn. Samples were irradiated to air doses of 15 mGy, 150 mGy and 1.5 Gy and analyzed using a commercially available OSL reader system to determine their luminescence response to continuous blue and infrared light (IR) excitation, centered at 470 nm and 830 nm wavelengths, respectively. CaF2:Mn did not show an OSL response with either IR or blue light stimulation. Li2B4O7:Cu and LiF:Mg,Ti demonstrated relatively weak OSL signals only under blue light excitation. CaSO4:Tm exhibited OSL under both IR and blue light stimulation at sensitivities roughly one order of magnitude less than the OSL response of α-Al2O3:C under the same conditions. - Highlights: • Optically stimulated luminescence (OSL) properties of several known thermoluminescent materials were investigated. • CaF2:Mn did not show an OSL response with either IR or blue light stimulation. • Li2B4O7:Cu and LiF:Mg,Ti demonstrated very weak OSL signals only under blue light excitation. • CaSO4:Tm exhibited OSL under both IR and blue light stimulation. • OSL properties of CaSO4:Tm indicated an optimal OSL readout regime

  16. Study of LiF:Mg,Ti and CaSO4:Dy dosimeters TL response to electron beams of 6 MeV applied to radiotherapy using PMMA and solid water phantoms

    International Nuclear Information System (INIS)

    The performance of CaSO4:Dy and LiF:Mg,Ti dosimeters to electron beams applied to radiotherapy was investigated. The TL response of these dosimeters was studied for 6 MeV electron beams using PMMA and Solid Water (SW) phantoms. The dosimeters were previously separated in groups according to their TL individual sensitivities to 60Co gamma-radiation in air under electronic equilibrium conditions. After that, they were irradiated with 6 MeV electron doses of 0.1, 0.5, 1, 5 and 10 Gy using a linear accelerator Clinac 2100C Varian of Hospital Israelita Albert Einstein – HIAE. The electron beam irradiations were performed using a 10 × 10 cm2 field size, 100 cm source-phantom surface distance and the dosimeters were positioned at the depth of maximum dose (1.2 cm). The TL readings were carried out between 24 and 32 h after irradiation using a Harshaw 3500 TL reader. The TL dose–response of both type of dosimeters and phantoms presented linear behavior on the electron dose range from 0.1 to 5 Gy CaSO4:Dy dosimeter is 21 times more sensitive than LiF:Mg,Ti, dosimeter commonly used in clinical dosimetry. The obtained results indicate that the performance of CaSO4:Dy dosimeters is similar to LiF:Mg,Ti dosimeters and this material can be an alternative dosimetric material to be used to clinical electron beams dosimetry.

  17. Arsenic speciation in synthetic gypsum (CaSO4·2H2O): A synchrotron XAS, single-crystal EPR, and pulsed ENDOR study

    Science.gov (United States)

    Lin, Jinru; Chen, Ning; Nilges, Mark J.; Pan, Yuanming

    2013-04-01

    Gypsum (CaSO4·2H2O) is a major by-product of mining and milling processes of borate, phosphate and uranium deposits worldwide and, therefore, potentially plays an important role in the stability and bioavailability of heavy metalloids, including As, in tailings and surrounding areas. Gypsum containing 1900 and 185 ppm As, synthesized with Na2HAsO4·7H2O and NaAsO2 in the starting materials, respectively, have been investigated by synchrotron X-ray absorption spectroscopy (XAS), single-crystal electron paramagnetic resonance spectroscopy (EPR), and pulsed electron nuclear double resonance spectroscopy (ENDOR). Quantitative analyses of As K edge XANES and EXAFS spectra show that arsenic occurs in both +3 and +5 oxidation states and the As3+/As5+ value varies from 0.35 to 0.79. Single-crystal EPR spectra of gamma-ray-irradiated gypsum reveal two types of arsenic-associated oxyradicals: [AsO3]2- and an [AsO2]2-. The [AsO3]2- center is characterized by principal 75As hyperfine coupling constants of A1 = 1952.0(2) MHz, A2 = 1492.6(2) MHz and A3 = 1488.7(2) MHz, with the unique A axis along the S-O1 bond direction, and contains complex 1H superhyperfine structures that have been determined by pulsed ENDOR. These results suggest that the [AsO3]2- center formed from electron trapping on the central As5+ ion of a substitutional (AsO4)3- group after removal of an O1 atom. The [AsO2]2- center is characterized by its unique A(75As) axis approximately perpendicular to the O1-S-O2 plane and the A2 axis along the S-O2 bond direction, consistent with electron trapping on the central As3+ ion of a substitutional (AsO3)3- group after removal of an O2 atom. These results confirm lattice-bound As5+ and As3+ in gypsum and point to potential application of this mineral for immobilization and removal of arsenic pollution.

  18. Oxygen Therapy

    Science.gov (United States)

    Oxygen therapy is a treatment that provides you with extra oxygen. Oxygen is a gas that your body needs to function. Normally, your lungs absorb oxygen from the air you breathe. But some conditions ...

  19. Asymmetric Carrier Random PWM

    DEFF Research Database (Denmark)

    Mathe, Laszlo; Lungeanu, Florin; Rasmussen, Peter Omand;

    2010-01-01

    This paper presents a new fixed carrier frequency random PWM method, where a new type of carrier wave is proposed for modulation. Based on the measurements, it is shown that the spread effect of the discrete components from the motor current spectra is very effective independent of the modulation...

  20. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  1. Supplemental Oxygen

    Science.gov (United States)

    ... Disease Lookup > COPD > Diagnosing and Treating COPD Supplemental Oxygen Sometimes with chronic obstructive pulmonary disease (COPD), lung ... in people with severe lung disease Three Ways Oxygen Therapy Is Supplied Compressed oxygen gas and liquid ...

  2. Effects of Oxygen Carrier, Surfactant and H2O2 on Fermentation of L-phenylalanine%氧载体、表面活性剂及H2O2对L-phe发酵影响的研究

    Institute of Scientific and Technical Information of China (English)

    翁雪清; 施巧琴; 吴松刚

    2012-01-01

    用添加氧载体(油酸、豆油)、表面活性剂(Triton-X100)及H2O2的方法,改善L-苯丙氨酸发酵体系中的氧传递速率,以提高苯丙氨酸的产量.实验结果表明,在发酵0h添加1%的豆油、3%的油酸均可使产酸提高,分别可以使L-phe产量提高21.1%和39.5%;发酵0h同时加入3%油酸和0.05% Triton-X100时,提高产量78.95%;发酵12h添加0.075%H2O2,可以提高产苯丙氨酸产量18.42%.%Oxygen vectors (oleic acid, soybean oil), surfactant (Triton-X100) and H2O2 can effectively improve the oxygen transfer rate in the fermentation system, and increase the yield of phenylalanine. Experimental results showed that, adding 1% soybean oil and 3% oleic acid before fermentation could make the L-phe production increased by 21. 1% and 39. 5% respectively; while adding 3% oleic acid and 0. 05% Triton-XlOO at the same time could make L-phe production increased by 78. 95% ; adding 0. 075% H2O2 at 12 h fermentation could make L-phenylalanine production increased by 18. 4%.

  3. Photoinduced Transformation between Charge Carrier and Spin Carrier in Polymers

    Institute of Scientific and Technical Information of China (English)

    MEI Yuan; ZHAO Chang; SUN Xin

    2006-01-01

    By dynamical simulations, we show a transforming process between neutral soliton (spin carrier) and charged soliton (charge carrier) in polymers via photo-excitation, taking a polaron as the transitional bridge. It is photoinduced transformation between spin carrier and charge carrier. In this way, we demonstrate an access for polymers to be applied to spintronics.

  4. The value of energy carriers

    NARCIS (Netherlands)

    Gool, W. van

    1987-01-01

    The value of energy carriers can be described thermodynamically by the amount of heat (enthalpy method) or work (exergy or availability method) that can be obtained from the carriers. Prices for energy carriers are used in economics to express their values. The prices for energy carriers are often r

  5. Using oxygen at home

    Science.gov (United States)

    Oxygen - home use; COPD - home oxygen; Chronic obstructive airways disease - home oxygen; Chronic obstructive lung disease - home oxygen; Chronic bronchitis - home oxygen; Emphysema - home oxygen; Chronic respiratory ...

  6. Duchenne muscular dystrophy carriers

    International Nuclear Information System (INIS)

    By means of magnetic resonance imaging (MRI), the proton spin-lattice relaxation times (T1 values) of the skeletal muscles were measured in Duchenne muscular dystrophy (DMD) carriers and normal controls. The bound water fraction (BWF) was calculated from the T1 values obtained, according to the fast proton diffusion model. In the DMD carriers, T1 values of the gluteus maximus and quadriceps femoris muscles were significantly higher, and BWFs of these muscles were significantly lower than in normal control. Degenerative muscular changes accompanied by interstitial edema were presumed responsible for this abnormality. No correlation was observed between the muscle T1 and serum creatine kinase values. The present study showed that MRI could be a useful method for studying the dynamic state of water in both normal and pathological skeletal muscles. Its possible utility for DMD carrier detection was discussed briefly. (orig.)

  7. The value of energy carriers

    OpenAIRE

    Gool, W. van

    1987-01-01

    The value of energy carriers can be described thermodynamically by the amount of heat (enthalpy method) or work (exergy or availability method) that can be obtained from the carriers. Prices for energy carriers are used in economics to express their values. The prices for energy carriers are often related to their enthalpies when other properties and conditions are equivalent. However, it has been suggested that the exergy of the energy carriers is the proper quantity to establish their value...

  8. Oxygen analyzer

    Science.gov (United States)

    Benner, William H.

    1986-01-01

    An oxygen analyzer which identifies and classifies microgram quantities of oxygen in ambient particulate matter and for quantitating organic oxygen in solvent extracts of ambient particulate matter. A sample is pyrolyzed in oxygen-free nitrogen gas (N.sub.2), and the resulting oxygen quantitatively converted to carbon monoxide (CO) by contact with hot granular carbon (C). Two analysis modes are made possible: (1) rapid determination of total pyrolyzable oxygen obtained by decomposing the sample at 1135.degree. C., or (2) temperature-programmed oxygen thermal analysis obtained by heating the sample from room temperature to 1135.degree. C. as a function of time. The analyzer basically comprises a pyrolysis tube containing a bed of granular carbon under N.sub.2, ovens used to heat the carbon and/or decompose the sample, and a non-dispersive infrared CO detector coupled to a mini-computer to quantitate oxygen in the decomposition products and control oven heating.

  9. Zaria Universal Oxygenator Holder Phase I

    OpenAIRE

    Sunday Adoga Edaigbini; Ibrahim Zira Delia; Muhammad Balarabe Aminu

    2014-01-01

    Introduction: The conduct of cardiopulmonary bypass surgery requires the use of equipment and devices like the oxygenator. The oxygenator comes in different makes and each manufacturer customizes the carrier or ′holder′ of this device specific to their design. Aim: This paper presents an innovation designed to overcome the need to purchase a different holder for every oxygenator thereby cutting the cost. Materials and Methods: A sheet of iron measuring 1.9 cm (width) × 0.1 cm (thickness) was ...

  10. Oxygen Carriers for Chemical Looping Combustion - 4 000 h of Operational Experience Transporteurs d’oxygène pour la combustion en boucle chimique : expérience accumulée pendant 4 000 h d’opération

    Directory of Open Access Journals (Sweden)

    Lyngfelt A.

    2011-04-01

    Full Text Available Chemical Looping Combustion (CLC is a new combustion technology with inherent separation of the greenhouse gas CO2. The technology involves the use of a metal oxide as an oxygen carrier which transfers oxygen from combustion air to the fuel, and hence a direct contact between air and fuel is avoided. Two interconnected fluidized beds, a fuel reactor and an air reactor, are used in the process. The outlet gas from the fuel reactor consists of CO2 and H2O, and the latter is easily removed by condensation. Considerable research has been conducted on CLC in the last years with respect to oxygen carrier development, reactor design, system efficiencies and prototype testing. Today, more than 700 materials have been tested and the technology has been successfully demonstrated in chemical looping combustors in the size range 0.3-140 kW, using different types of oxygen carriers based on oxides of the metals Ni, Co, Fe, Cu and Mn. The total time of operational experience is more than 4 000 hours. From these tests, it can be established that almost complete conversion of the fuel can be obtained and 100% CO2 capture is possible. Most work so far has been focused on gaseous fuels, but the direct application to solid fuels is also being studied. This paper presents an overview of operational experience with oxygen carriers in chemical looping combustors. La combustion en boucle chimique (CLC est une nouvelle technique de combustion permettant la séparation intrinsèque du CO2. Dans ce procédé, un oxyde métallique est utilisé comme transporteur d’oxygène pour véhiculer l’oxygène de l’air vers le combustible, ce qui permet d’éviter un contact direct entre le combustible et l’air. Deux lits fluidisés interconnectés sont utilisés, le réacteur air et le réacteur de combustion. Les fumées du réacteur de combustion contiennent le CO2 et la vapeur d’eau qui peut être facilement éliminée par condensation. Des recherches consid

  11. Study of CaSO4-C-H2O System: Simulation Experiments and Thermodynamic Assessment%CaSO4-C-H2O体系研究:模拟实验与热力学探讨

    Institute of Scientific and Technical Information of China (English)

    丁康乐; 罗跃; 单敬福; 关富佳; 王莎莎

    2013-01-01

    It has been traditionally believed that the TSR solid bitumens (pyrobitumen) are the direct product of thermochemical process and has less effect over the process of thermochemical sulfate reduction (TSR) compared with hydrogen sulfide (H2S). In this study, thermochemical simulation experiment of the CaSO4-C-H2O system was conducted to investigate thermodynamic characteristics of STR in the CaSo4-C-H2O system using activated carbon (C) as a model compound of solid bitumen. The results show that CaSO4-C-H2O system initiated TSR process at the temperature of 300°C , generating products like CaCO3, H2S and CO2. The threshold temperature (300°C) is much lower than temperature range of the TSR simulation tests using hydrocarbons in both gaseous and aqueous states, and consistent with the result through thermodynamic calculations. Process simulation of TSR was conducted using the software of HSC Chemistry 5. 0. It was found that TSR in the CaSOf-C-H2O system initiated at reservoir temperatures of 25~200°C was completely controlled by kinetic factors and increasing pressure is unfavorable to initiation of TSR under a constant temperature. The intensity of TSR is likely associated with saturation concentration of CaSO4 in water: a small amount of water may contribute to better oxidizing conditions while excessive water likely restrains the process of TSR. Under the conditions of pH≤2 and certain temperature, amount of sulfate decreased with decreasing pH. However, for pH range (pH>4) formation water in sedimentary basins, effect of pH on TSR can be negligible. TSR in the system of CaSO4-C-H2O is an exothermic process, and the reaction heat increases with the increasing temperatures. It was established that reaction heat of TSR is about 12. 9-133 J/mol CaSO4 at 25~200°C. Thermodynamic studies and experimental results imply that solid bitumens (pyrobitumen) are much easily involved in TSR than gaseous or aqueous hydrocarbons.%传统认为TSR成因的固态沥青(焦沥青)属于热化学反应的终端产物,不会对TSR的反应进程起到重要作用.本文以活性炭作为固态沥青(焦沥青)的模型化合物,开展了CaSO4-C-H2O体系的热模拟实验研究,探讨了CaSO4-C-H2O体系发生TSR的热力学特征.实验结果表明,CaSO4-C-H2O体系在300℃时即可启动TSR,主要生成CaCO3、H2S和CO2等产物.这一TSR门限温度要远低于以往室内利用气态或液态烃类进行的TSR模拟实验温度范围,与热力学计算结果一致.利用HSC Chemistry 5.0软件进行TSR过程模拟,发现25~200℃时CaSO4-C-H2O体系发生的TSR完全受动力学控制,在温度保持不变情况下,压力增大不利于CaSO4-C-H2O体系发生TSR.较少的含水量对TSR有一定促进作用,而含水量过多则可能抑制TSR的进行,含水量对TSR的影响可能与CaSO4在水中的饱和浓度有关.在一定的温度下,当体系pH≤2时,随着pH逐渐降低,CaSO4的量呈线性递减,但在沉积盆地地层水pH范围内(pH>4),pH对TSR的作用可以忽略不计.CaSO4-C-H2O体系发生的TSR反应是一个放热过程,并且随着温度升高,反应热逐渐增大.在25~200℃范围内,TSR反应热为12.9~133 J/molCaSO4.热力学计算以及模拟实验结果均暗示,固态沥青(焦沥青)可能比烃类更容易参与TSR.

  12. Information and Its Carriers.

    Science.gov (United States)

    Herrmann, F.; And Others

    1985-01-01

    Describes: (1) the structure of a data transmission source, carrier, and receiver; (2) a quantitative measure for the amount of data, followed by some quantitative examples of data transmission processes; (3) the concept of data current; (4) data containers; and (5) how this information can be used to structure physics courses. (JN)

  13. Oxygen Delivering Biomaterials for Tissue Engineering

    Science.gov (United States)

    Farris, Ashley L.; Rindone, Alexandra N.; Grayson, Warren L.

    2016-01-01

    Tissue engineering (TE) has provided promising strategies for regenerating tissue defects, but few TE approaches have been translated for clinical applications. One major barrier in TE is providing adequate oxygen supply to implanted tissue scaffolds, since oxygen diffusion from surrounding vasculature in vivo is limited to the periphery of the scaffolds. Moreover, oxygen is also an important signaling molecule for controlling stem cell differentiation within TE scaffolds. Various technologies have been developed to increase oxygen delivery in vivo and enhance the effectiveness of TE strategies. Such technologies include hyperbaric oxygen therapy, perfluorocarbon- and hemoglobin-based oxygen carriers, and oxygen-generating, peroxide-based materials. Here, we provide an overview of the underlying mechanisms and how these technologies have been utilized for in vivo TE applications. Emerging technologies and future prospects for oxygen delivery in TE are also discussed to evaluate the progress of this field towards clinical translation.

  14. Intestinal solute carriers

    DEFF Research Database (Denmark)

    Steffansen, Bente; Nielsen, Carsten Uhd; Brodin, Birger;

    2004-01-01

    membrane transporters in the small intestine in order to increase oral bioavailabilities of drug or prodrug, the major influence on in vivo pharmacokinetics is suggested to be dose-dependent increase in bioavailability as well as prolonged blood circulation due to large capacity facilitated absorption......A large amount of absorptive intestinal membrane transporters play an important part in absorption and distribution of several nutrients, drugs and prodrugs. The present paper gives a general overview on intestinal solute carriers as well as on trends and strategies for targeting drugs and....../or prodrugs to these carriers in order to increasing oral bioavailability and distribution. A number of absorptive intestinal transporters are described in terms of gene and protein classification, driving forces, substrate specificities and cellular localization. When targeting absorptive large capacity...

  15. 化学链燃烧反应中LaFe1-xCoxO3载氧体的性能研究%PERFORMANCE STUDY OF LaFe1-xCoxO3 AS OXYGEN CARRIERS IN CHEMICAL-LOOPING COMBUSTION REACTION

    Institute of Scientific and Technical Information of China (English)

    梁皓; 尹泽群; 张喜文; 方向晨

    2013-01-01

    A series of LaFe1-xCoxO3 oxygen carriers with different Co content were prepared by citric acid complex method,and their properties were characterized by thermal analysis,X-ray diffraction,temperature program reduction and scanning electron microscopy.The catalytic performance of the prepared samples was investigated in chemical-looping combustion of CO.XRD results showed that LaFe1-xCoxO3 oxides possessed perovskite-type structure.TPR results indicated that oxidizing ability of LaCoO3 was stronger than that of LaFeO3.Especially,the sequential redox reaction revealed that LaCoO3 oxide exhibits high oxygen delivery capacity after 10 redox cycles,in each cycle the CO conversion is 100%.Also the structure of LaCoO3 oxide didn't change much after 10 cycles besides new network structure which was formed under high temperature.All the results showed that LaCoO3 was suit to be oxygen carrier in chemical-looping combustion owing to its high activity and stability.%采用柠檬酸络合法制备不同Co含量的LaFe1-xCoxO3系列复合氧化物载氧体.采用热分析、X射线衍射(XRD)、程序升温还原(TPR)和扫描电镜等手段对载氧体进行表征,并在化学链燃烧反应中进行性能评价.XRD表征结果表明,不同Co含量的LaFe1xCoxO3均能形成钙钛矿结构.TPR表征结果可以说明LaCoO3中的氧物种氧化能力强于LaFeO3.在连续10次化学链燃烧反应中,燃料CO全部被氧化,这归于LaCoO3持续供氧能力强的特点.LaCoO3循环10次后仍然保持钙钛矿结构不变,而且颗粒没有长大,只是颗粒之间形成了网状结构.通过该实验发现LaCoO3具有高活性和较强的稳定性,适合作化学链燃烧技术的载氧体.

  16. Hungarian students’ carrier aspirations

    Directory of Open Access Journals (Sweden)

    A.S. Gubik

    2014-06-01

    Full Text Available The article analyzes the students’ carrier aspiration, right after their graduation and five years after their studies. It examines the differences arising from the students’ family business background and their most important social variables (gender, age. Then the study highlights the effects of study field on the students’ intention. The direct effect of education on starting an enterprise is undiscovered in the literature, the paper deals with the influence of availability and services use, offered by higher institutions.

  17. Carrier transport uphill. I. General

    DEFF Research Database (Denmark)

    Rosenberg, T; Wilbrandt, W

    1963-01-01

    A quantitative treatment of a carrier pump operating with two carrier forms C and Z is presented. Asymmetric metabolic reactions are assumed to transform Z into C on one and C into Z on the other side of the membrane, establishing a carrier cycle. The kinetical consequences of this mechanism...

  18. Maintainable substrate carrier for electroplating

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chen-An; Abas, Emmanuel Chua; Divino, Edmundo Anida; Ermita, Jake Randal G.; Capulong, Jose Francisco S.; Castillo, Arnold Villamor; Ma, Diana Xiaobing

    2016-08-02

    One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The carrier includes a non-conductive carrier body on which the substrates are placed and conductive lines embedded within the carrier body. A plurality of conductive clip attachment parts are attached in a permanent manner to the conductive lines embedded within the carrier body. A plurality of contact clips are attached in a removable manner to the clip attachment parts. The contact clips hold the substrates in place and conductively connecting the substrates with the conductive lines. Other embodiments, aspects and features are also disclosed.

  19. Appreciating Oxygen

    Science.gov (United States)

    Weiss, Hilton M.

    2008-01-01

    Photosynthetic flora and microfauna utilize light from the sun to convert carbon dioxide and water into carbohydrates and oxygen. While these carbohydrates and their derivative hydrocarbons are generally considered to be fuels, it is the thermodynamically energetic oxygen molecule that traps, stores, and provides almost all of the energy that…

  20. Comparison of airline passenger oxygen systems.

    Science.gov (United States)

    Byrne, N J

    1995-08-01

    The principal sources of oxygen for inflight passenger use, scheduled and unscheduled, are examined. Present practices of assessment of the passenger's "fitness to fly" are described. Three partner airlines, British Airways, U.S. Air, and Qantas, catering for more than 8000 oxygen requests annually, are compared. Analysis of customer use suggests that medical oxygen requests are frequently not clinically justified. The growth in demand, for both scheduled and unscheduled use of an expensive resource, supports the need for a "recommended best practice" among carriers. Passengers with respiratory disorders who will most benefit from inflight oxygen are vulnerable either to hypoxia or asthma. PMID:7487813

  1. 化学链燃烧中LaNixFe1-xO3载氧体的性能研究%Performance of LaNixFe1-xO3 as Oxygen Carriers in Chemical-Looping Combustion Reaction

    Institute of Scientific and Technical Information of China (English)

    王钰佳; 梁皓; 张喜文; 孙万付; 方向晨

    2013-01-01

    A series of LaNixFe1-x O3 oxygen carriers with different Ni content was prepared by citric acid complex method, and their properties were characterized by thermal analysis, X-ray diffraction, temperature programmed reduction and scanning electron microscopy. The catalytic performances of the prepared samples were investigated in chemical-looping combustion of CO. The XRD results showed that LaNixFe1-x O3 oxides possessed perovskite-type structure. TPR results indicated that the oxidation ability of LaNix Fe1-x O3(x> 0) was stronger than that of LaFeO3. Especially, the sequential redox reaction revealed that LaFe0.5 Ni0.5 O3 oxide exhibited high oxygen delivery capacity after 10 redox cycles, and CO conversion ratio was above 95% in each cycle. The structure of LaFe0.5 Ni0.5 O3 oxide did not change obviously after 10 cycles except some little particles formed on big particles due to heat release in the oxidation processes.%采用柠檬酸络合法制备了不同Ni含量的LaNixFe1-xO3系列复合氧化物载氧体.采用热分析、X射线衍射、程序升温还原和扫描电境等手段对载氧体进行了表征,并在化学链燃烧反应中进行性能评价.XRD表征结果表明不同Ni含量的LaNixFe1-xO3均能形成钙钛矿结构,TPR表征结果表明随Ni含量增加,LNixaFe1-xO3上氧数量增加,还原能力增强.在连续十次化学链燃烧反应中,95%一氧化碳在LaFe0.5Ni0.5O3上被氧化,扫描电境照片发现部分载氧体颗粒出现破碎、烧结现象.

  2. Materials for Chemical-Looping with Oxygen Uncoupling

    OpenAIRE

    Tobias Mattisson

    2013-01-01

    Chemical-looping with oxygen uncoupling (CLOU) is a novel combustion technology with inherent separation of carbon dioxide. The process is a three-step process which utilizes a circulating oxygen carrier to transfer oxygen from the combustion air to the fuel. The process utilizes two interconnected fluidized bed reactors, an air reactor and a fuel reactor. In the fuel reactor, the metal oxide decomposes with the release of gas phase oxygen (step 1), which reacts directly with the fuel through...

  3. Particle temperature measurements in closed chamber detonations using thermoluminescence from Li2B4O7:Ag,Cu, MgB4O7:Dy,Li and CaSO4:Ce,Tb

    International Nuclear Information System (INIS)

    The present work describes the procedures and results from the first temperature measurements in closed chamber detonations obtained using the thermoluminescence (TL) of particles specifically developed for temperature sensing. Li2B4O7:Ag,Cu (LBO), MgB4O7:Dy,Li (MBO) and CaSO4:Ce,Tb (CSO) were tested separately in a total of 12 independent detonations using a closed detonation chamber at the Naval Surface Warfare Center, Indian Head Explosive Ordnance Disposal Technology Division (NSWC IHEODTD). Detonations were carried out using two different explosives: a high temperature plastic bonded explosive (HPBX) and a low temperature plastic bonded explosive (LPBX). The LPBX and HPBX charges produced temperatures experienced by the TL particles to be between ~550–670 K and ~700–780 K, respectively, depending on the shot. The measured temperatures were reproducible and typically higher than the thermocouple temperatures. These tests demonstrate the survivability of the TL materials and the ability to obtain temperature estimates in realistic conditions, indicating that TL may represent a reliable way of estimating the temperature experienced by free-flowing particles inside an opaque post-detonation fireball. - Highlights: • TL materials were tested in closed chamber detonations. • Temperatures experienced by the particles were ~550–670 K and ~700–780 K. • TL temperatures were reproducible and higher than thermocouple measurements. • Tests demonstrate TL material survival and ability to obtain temperature estimates

  4. Autonomous component carrier selection

    DEFF Research Database (Denmark)

    Garcia, Luis Guilherme Uzeda; Pedersen, Klaus; Mogensen, Preben

    2009-01-01

    in local areas, basing our study case on LTE-Advanced. We present extensive network simulation results to demonstrate that a simple and robust interference management scheme, called autonomous component carrier selection allows each cell to select the most attractive frequency configuration; improving......Low-power base stations such as e.g. Femto-cells are one of the candidates for high data rate provisioning in local areas, such as residences, apartment complexes, business offices and outdoor hotspot scenarios. Unfortunately, the benefits are not without new challenges in terms of interference...... management and efficient system operation. Due to the expected large number of user-deployed cells, centralized network planning becomes unpractical and new scalable alternatives must be sought. In this article, we propose a fully distributed and scalable solution to the interference management problem...

  5. Oxygen Incorporation in Rubrene Single Crystals

    Science.gov (United States)

    Mastrogiovanni, Daniel D. T.; Mayer, Jeff; Wan, Alan S.; Vishnyakov, Aleksey; Neimark, Alexander V.; Podzorov, Vitaly; Feldman, Leonard C.; Garfunkel, Eric

    2014-05-01

    Single crystal rubrene is a model organic electronic material showing high carrier mobility and long exciton lifetime. These properties are detrimentally affected when rubrene is exposed to intense light under ambient conditions for prolonged periods of time, possibly due to oxygen up-take. Using photoelectron, scanning probe and ion-based methods, combined with an isotopic oxygen exposure, we present direct evidence of the light-induced reaction of molecular oxygen with single crystal rubrene. Without a significant exposure to light, there is no reaction of oxygen with rubrene for periods of greater than a year; the crystal's surface (and bulk) morphology and chemical composition remain essentially oxygen-free. Grand canonical Monte Carlo computations show no sorbtion of gases into the bulk of rubrene crystal. A mechanism for photo-induced oxygen inclusion is proposed.

  6. Drug Carrier for Photodynamic Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Tilahun Ayane Debele

    2015-09-01

    Full Text Available Photodynamic therapy (PDT is a non-invasive combinatorial therapeutic modality using light, photosensitizer (PS, and oxygen used for the treatment of cancer and other diseases. When PSs in cells are exposed to specific wavelengths of light, they are transformed from the singlet ground state (S0 to an excited singlet state (S1–Sn, followed by intersystem crossing to an excited triplet state (T1. The energy transferred from T1 to biological substrates and molecular oxygen, via type I and II reactions, generates reactive oxygen species, (1O2, H2O2, O2*, HO*, which causes cellular damage that leads to tumor cell death through necrosis or apoptosis. The solubility, selectivity, and targeting of photosensitizers are important factors that must be considered in PDT. Nano-formulating PSs with organic and inorganic nanoparticles poses as potential strategy to satisfy the requirements of an ideal PDT system. In this review, we summarize several organic and inorganic PS carriers that have been studied to enhance the efficacy of photodynamic therapy against cancer.

  7. Thermodinamically stable phases in the CaO-SiO2-Al2O3-CaSO4-H2O closed system at 25 ºC. Application to cementitious systems

    Directory of Open Access Journals (Sweden)

    Blanco-Varela, M. T.

    2009-06-01

    Full Text Available One of the chief causes of cement and concrete deterioration is the loss of durability prompted by sulphate attack. The existing standards call for long test periods (2- 12 months. Thermodynamic modelling is a particularly appropriate technique for studying systems that only reach equilibrium in the long term. Used in the present study to establish the fields of thermodynamic stability for the phases in the CaO-SiO2-Al2O3-CaSO4-H2O system at 25 ºC. According to the model, gypsum is stable at sulphate ion concentrations of 1.23e-2 mol/kg and over, while ettringite exhibits stability at concentrations ranging from 7.64e-6 to 1.54e-2 mol/kg. Ettringite is compatible with all system phases except SH and gypsum only with ettringite, the C-S-H gels, AH3 and SH. None of the calcium aluminates or silicoaluminates in the system is compatible with gypsum: in its presence, they all decompose to cement deteriorating ettringite. Finally, the model revealed that the maximum sulphate concentration at which C-S-H gel is stable is slightly higher in systems with than without Al2O3.Uno de los principales problemas asociados al deterioro de cementos y hormigones es la pérdida de durabilidad por ataque de sulfatos. La normativa existente requiere largos tiempos de ensayo (2-12 meses. La modelización termodinámica es una técnica particularmente adecuada para el estudio de sistemas que alcanzan el equilibrio en tiempos largos. Aplicando esta metodología se han establecido los campos de estabilidad termodinámica de las fases del sistema CaO-SiO2-Al2O3-CaSO4-H2O a 25 ºC. El yeso es estable a partir de la [SO42-] = 1,23e-2 mol/kg, y la ettringita es estable en un rango de [SO42-] = 7,64e-6 -1,54e-2 mol/kg. La ettringita es compatible con todas las fases del sistema excepto con SH y el yeso sólo con la ettringita, los geles C-S-H, el AH3 y el SH. Ninguno de los aluminatos o silicoaluminatos cálcicos son compatibles con el yeso, en su presencia se descomponen dando etringita. Finalmente, la máxima [SO42-] en la que es estable el gel C-S-H es ligeramente superior en sistemas que contienen Al2O3 con respecto a los que no lo poseen.

  8. 新型硫酸钙除垢剂的性能和应用研究%Study on performance and application of a novel CaSO4 scale remover

    Institute of Scientific and Technical Information of China (English)

    孔令广; 贺茂才; 刘见

    2012-01-01

    针对CaSO4垢结构紧密、硬度大、很难用传统的方法清除的难题,研制了一种CaSO4除垢剂.这种除垢剂具有除垢效率高、无毒、安全性好、对管道设备腐蚀小、成本低、使用方便等特点.本文分别介绍了除垢时间、温度、pH值、加药量等因素对除垢率的影响.通过试验和现场应用证明:TH-708是一种高效的CaSO4除垢剂.%Aiming at the problem of calcium sulfate which is characteristic of compact structure,high hardness and difficult to be removed on the industry water systems, a new type CaSO4 scale remover (TH-708) was prepared. Compared with conventional scale remover, it proved that the performance of the new scale remover was characteristic of high efficiency of removing scale, non-toxicity, safety, little corrosion on pipe equipment, low cost and easy application. The influences of time, temperature, pH and initiator concentrations on descaling rate were investigated. Through studies of laboratory and application on site, it proves that TH-708 is a new type scale remover with high descaling rate.

  9. Chemical Looping Pilot Plant Results Using a Nickel-Based Oxygen Carrier Résultats de l’expérimentation sur un pilote opérant en boucle chimique avec un matériau transporteur d’oxygène à base de nickel

    Directory of Open Access Journals (Sweden)

    Pröll T.

    2011-04-01

    Full Text Available A chemical looping pilot plant was designed, built and operated with a design fuel power of 120 kW (lower heating value, natural gas. The system consists of two Circulating Fluidized Bed (CFB reactors. Operating results are presented and evaluated for a highly reactive nickel-based oxygen carrier, total system inventory 65 kg. The performance in fuel conversion achieved is in the range of 99.8% (CH4 conversion and 92% (CO2 yield. In chemical looping reforming operation, it can be reported that thermodynamic equilibrium is reached in the fuel reactor and that all oxygen is absorbed in the air reactor as soon as the global stoichiometric air/fuel ratio is below 1 and the air reactor temperature is 900°C or more. Even though pure natural gas (98.6 vol.% CH4 without steam addition was fed to the fuel reactor, no carbon formation has been found as long as the global stoichiometric air/fuel ratio was larger than 0.4. Based on the experimental findings and on the general state of the art, it is concluded that niche applications such as industrial steam generation from natural gas or CO2-ready coupled production of H2 and N2 can be interesting pathways for immediate scale-up of the technology. Un pilote d’étude de la combustion en boucle chimique d’une puissance thermique de 120 kW a été dimensionné, construit et opéré. Il est constitué de deux lits circulants interconnectés. Les résultats d’opération qui sont présentés ont été obtenus avec un matériau transporteur d’oxygène très réactif à base de nickel. L’inventaire total du matériau est de 65 kg dans le pilote. La conversion du méthane atteinte est voisine de 99,8 % et le rendement en CO2 est de 92 %. Lorsqu’on opère en mode de reformage, l’équilibre thermodynamique est atteint dans le réacteur fioul. Tout l’oxygène est capté dans le réacteur air dès que le rapport stoechiométrique entre l’air et le méthane est inférieur à 1 et que la temp

  10. Nanostructured Lipid Carriers: A potential drug carrier for cancer chemotherapy

    Directory of Open Access Journals (Sweden)

    Selvamuthukumar Subramanian

    2012-11-01

    Full Text Available Abstract Nanotechnology having developed exponentially, the aim has been on therapeutic undertaking, particularly for cancerous disease chemotherapy. Nanostructured lipid carriers have attracted expanding scientific and commercial vigilance in the last couple of years as alternate carriers for the pharmaceutical consignment, particularly anticancer pharmaceuticals. Shortcomings often came across with anticancer mixtures, such as poor solubility, normal tissue toxicity, poor specificity and steadiness, as well as the high incidence rate of pharmaceutical resistance and the rapid degradation, need of large-scale output procedures, a fast release of the pharmaceutical from its carrier scheme, steadiness troubles, the residues of the organic solvents utilized in the output method and the toxicity from the polymer with esteem to the carrier scheme are anticipated to be overcome through use of the Nanostructured Lipid Carrier. In this review the benefits, types, drug release modulations, steadiness and output techniques of NLCs are discussed. In supplement, the function of NLC in cancer chemotherapy is presented and hotspots in research are emphasized. It is foreseen that, in the beside future, nanostructured lipid carriers will be further advanced to consign cytotoxic anticancer compounds in a more efficient, exact and protected manner.

  11. Basic Stand Alone Carrier Line Items PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Carrier Line Items Public Use Files (PUF) with information from Medicare Carrier claims. The CMS BSA Carrier Line...

  12. Oxygen Transport Ceramic Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay; T. Nithyanantham

    2006-12-31

    Ti doping on La{sub 1-x}Sr{sub x}FeO{sub 3-{delta}} (LSF) tends to increase the oxygen equilibration kinetics of LSF in lower oxygen activity environment because of the high valence state of Ti. However, the addition of Ti decreases the total conductivity because the acceptor ([Sr{prime}{sub La}]) is compensated by the donor ([Ti{sub Fe}{sup {sm_bullet}}]) which decreases the carrier concentration. The properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 1-x}Ti{sub x}O{sub 3-{delta}} (LSFT, x = 0.45) have been experimentally and theoretically investigated to elucidate (1) the dependence of oxygen occupancy and electrochemical properties on temperature and oxygen activity by thermogravimetric analysis (TGA) and (2) the electrical conductivity and carrier concentration by Seebeck coefficient and electrical measurements. In the present study, dual phase (La{sub 0.2}Sr{sub 0.8}Fe{sub 0.6}Ti{sub 0.4}O{sub 3-{delta}}/Ce{sub 0.9}Gd{sub 0.1}O{sub 2-{delta}}) membranes have been evaluated for structural properties such as hardness, fracture toughness and flexural strength. The effect of high temperature and slightly reducing atmosphere on the structural properties of the membranes was studied. The flexural strength of the membrane decreases upon exposure to slightly reducing conditions at 1000 C. The as-received and post-fractured membranes were characterized using XRD, SEM and TG-DTA to understand the fracture mechanisms. Changes in structural properties of the composite were sought to be correlated with the physiochemical features of the two-phases. We have reviewed the electrical conductivity data and stoichiometry data for La{sub 0.2}Sr{sub 0.8}Cr{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} some of which was reported previously. Electrical conductivity data for La{sub 0.2}Sr{sub 0.8}Cr{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCrF) were obtained in the temperature range, 752 {approx} 1055 C and in the pO{sub 2} range, 10{sup -18} {approx} 0.5 atm. The slope of the plot of log {sigma} vs

  13. 基于补偿效应下CaSO4产物层离子扩散的研究%The study of ion diffusion in CaSO4 product layer based on compensation effect

    Institute of Scientific and Technical Information of China (English)

    王松岭; 尚建宇; 冯垚飞

    2011-01-01

    石灰石脱硫反应中,高温热激活使得晶体产生大量的缺陷,局部电中性失去平衡,产物层内部Ca2向外运动形成固态离子扩散.以直接脱硫实验为基础,利用电导率补偿效应找到了CaSO4产物层的特征温度和特征电导率,通过曲线拟舍得到了产物层扩散激活能,最终计算获得了产物层离子扩散系数与温度之间的关系,结果表明:产物层离子扩散系数与温度成指数关系,温度越高,离子扩散系数越大,钙离子越活跃.较大迁移率使得更多的Ca2跃迁至产物层表面与气体分子发生反应,有利于脱硫反应的进行,但考虑到高温石灰石会发生烧结,因此合理地选择脱硫温度是改善硫化反应的根本途径.%Thermal activation may lead to large amount of crystal defects, the local electrical neutrality was smashed and solid-state ion diffusion was formed for the sake of the movement of calcium in product layer at high temperatures. Based on the direct desulphurization experiment, this article is aimed to obtain the relationship between ion diffusion coefficient and temperature when characteristic temperature, characteristic conductivity and diffusion activation energy of CaSO4 product layer were calculated with the help of conductivity compensation effect and curve fitting. The results show that ion diffusion coefficient and temperature are exponential relationship, in addition, the higher the temperature , the bigger the ion diffusion coefficient, the more activate of calcium ions. The greater mobility , which is conducive to desulphurization, may lead large transition of calcium ions to the surface of product layer to react with gas molecules, however, limestone in high temperature will be sintered, so choosing reasonable desulphurization temperature is an appropriate way to improve the desulphurization reaction.

  14. 三种阻垢剂阻硫酸钙垢协同效应的研究%Study on synergistic effect of three CaSO4 scale inhibitors

    Institute of Scientific and Technical Information of China (English)

    王庚平; 蒲瑜

    2011-01-01

    采用电导法研究了聚天冬氨酸(PASP)、羟基亚乙基二膦酸(HEDP)、2-膦酸基-1,2,4三羧基丁烷(PBTCA)三种阻垢剂单组分时的阻CaSO4垢性能以及二元复配、三元复配后的协同效应。考察了pH、温度等条件对二元复配物阻垢性能的影响。实验表明:二元组合除PASP和PBTCA之间存在协同效应,其余组合不存在协同效应,且P(PASP):P(PBTCA)为8:2时阻CaSO4垢性能最好;三元组合阻垢性能有所提升但未超过PASP和PBTCA的二元组合,表明HDEP与PASP和PBTCA之间无协同效应;p(PASP):P(PBTCA)为8:2的复配阻垢剂,其阻硫酸钙性能在温度范围为40~90℃之间随着温度升高而下降,但不受pH变化影响。%The CaSO4 resistance performance of three scale inhibitors PASP, HEDP, PBTCA and their combination were determined by conductometric method. The effect of tempetature, pH on the scale inhibiting performance of two-component system was studied too. It was found that the synergistic effect of the two-component system which having ratio of p (PASP) : p (PBTCA) as 8: 2 shows the best antiscaling performance and the scale inhibition performance lowered with the increase of temperature and the scale inhibiting performance is remain constant when pH increased from 6.0 to 9.0.

  15. Comparison of LaFeO3, La0.8Sr0.2FeO3, and La0.8Sr0.2Fe0.9Co0.1O3 perovskite oxides as oxygen carrier for partial oxidation of methane

    Institute of Scientific and Technical Information of China (English)

    Xiaoping Dai; Changchun Yu; Qiong Wu

    2008-01-01

    Comparison of LaFeO3, La0.8Sr0.2FeO3, and La0.8Sr0.2Fe0.9Co0.1O3 perovskite oxides as oxygen cartier for partial oxidation of methane in the absence of gaseous oxygen was investigated by continuous flow reaction and sequential redox reaction. Methane was oxidized to syngas with high selectivity by oxygen species of perovskite oxides in the absence of gaseous oxygen. The sequential redox reaction revealed that the structural stability and continuous oxygen supply in redox re-action decreased over La0.8Sr0.2Fe0.9Co0.1O3 oxide, while LaFeO3 and Lao.sSro.2FeO3 exhibited excellent structural stability and continuous oxygen supply.

  16. Tailoring the surface properties and carrier dynamics in SnO2 nanowires.

    Science.gov (United States)

    Kar, Ayan; Stroscio, Michael A; Meyyappan, M; Gosztola, David J; Wiederrecht, Gary P; Dutta, Mitra

    2011-07-15

    We report a study of the role of mid-gap defect levels due to surface states in SnO(2) nanowires on carrier trapping. Ultrafast pump-probe spectroscopy provides carrier relaxation time constants that reveal the nature and positions of various defect levels due to the surface states which in turn provide details on how the carriers relax after their injection. The effect of oxygen annealing on carrier concentration is also studied through XPS valence band photoemission spectroscopy, a sensitive non-contact surface characterization technique. These measurements show that charge transfer associated with chemisorption of oxygen in different forms produces an upward band bending and leads to an increase in the depletion layer width by approximately 70 nm, thereby decreasing surface conductivity and forming the basis for the molecular sensing capability of the nanowires.

  17. Tailoring the surface properties and carrier dynamics in SnO{sub 2} nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Kar, Ayan; Stroscio, Michael A; Dutta, Mitra [Electrical and Computer Engineering Department, University of Illinois, Chicago, IL 60607 (United States); Meyyappan, M [Center for Nanotechnology, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Gosztola, David J; Wiederrecht, Gary P, E-mail: dutta@ece.uic.edu [Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2011-07-15

    We report a study of the role of mid-gap defect levels due to surface states in SnO{sub 2} nanowires on carrier trapping. Ultrafast pump-probe spectroscopy provides carrier relaxation time constants that reveal the nature and positions of various defect levels due to the surface states which in turn provide details on how the carriers relax after their injection. The effect of oxygen annealing on carrier concentration is also studied through XPS valence band photoemission spectroscopy, a sensitive non-contact surface characterization technique. These measurements show that charge transfer associated with chemisorption of oxygen in different forms produces an upward band bending and leads to an increase in the depletion layer width by approximately 70 nm, thereby decreasing surface conductivity and forming the basis for the molecular sensing capability of the nanowires.

  18. Monitoring oxygenation.

    Science.gov (United States)

    Severinghaus, John W

    2011-06-01

    Cyanosis was used for a century after dentists began pulling teeth under 100% N(2)O in 1844 because brief (2 min) severe hypoxia is harmless. Deaths came with curare and potent anesthetic respiratory arrest. Leland Clark's invention of a polarographic blood oxygen tension electrode (1954) was introduced for transcutaneous PO2 monitoring to adjust PEEP and CPAP PO2 to prevent premature infant blindness from excess O2 (1972). Oximetry for warning military aviators was tried after WW II but not used for routine monitoring until Takuo Aoyagi (1973) discovered an equation to measure SaO2 by the ratio of ratios of red and IR light transmitted through tissue as it changed with arterial pulses. Pulse oximetry (1982) depended on simultaneous technology improvements of light emitting red and IR diodes, tiny cheap solid state sensors and micro-chip computers. Continuous monitoring of airway anesthetic concentration and oxygen also became very common after 1980. Death from anesthesia fell 10 fold between 1985 and 2000 as pulse oximetry became universally used, but no proof of a causative relationship to pulse oximetry exists. It is now assumed that all anesthesiologist became much more aware of the dangers of prolonged hypoxia, perhaps by using the pulse oximeters. PMID:21717228

  19. Straddle carrier radiation portal monitoring

    Science.gov (United States)

    Andersen, Eric S.; Samuel, Todd J.; Mullen, O. Dennis

    2005-05-01

    U.S. Customs and Border Protection (CBP) is the primary enforcement agency protecting the nation"s ports of entry. CBP is enhancing its capability to interdict the illicit import of nuclear and radiological materials and devices that may be used by terrorists. Pacific Northwest National Laboratory (PNNL) is providing scientific and technical support to CBP in their goal to enable rapid deployment of nuclear and radiation detection systems at U. S. ports of entry to monitor 100% of the incoming international traffic and cargo while not adversely impacting the operations or throughput of the ports. The U.S. ports of entry include the following vectors: land border crossings, seaports, airports, rail crossings, and mail and express consignment courier facilities. U.S. Customs and Border Protection (CBP) determined that a screening solution was needed for Seaport cargo containers being transported by Straddle Carriers (straddle carriers). A stationary Radiation Portal Monitor (RPM) for Straddle Carriers (SCRPM) is needed so that cargo containers can be scanned while in transit under a Straddle Carrier. The Straddle Carrier Portal operational impacts were minimized by conducting a time-motion study at the Port, and adaptation of a Remotely Operated RPM (RO-RPM) booth concept that uses logical lighting schemes for traffic control, cameras, Optical Character Recognition, and wireless technology.

  20. Impact of carriers in oral absorption

    DEFF Research Database (Denmark)

    Gram, Luise Kvisgaard; Rist, Gerda Marie; Lennernäs, Hans;

    2009-01-01

    Carriers may mediate the permeation across enterocytes for drug substances being organic anions. Carrier mediated permeation for the organic anions estrone-3-sulfate (ES) and glipizide across Caco-2 cells were investigated kinetically, and interactions on involved carriers evaluated. Initial......(APP) was not described by carrier kinetics. However, glipizide is affecting exsorption for ES, due to interactions on basolateral carrier. The study confirms that estrone-3-sulfate can be used to characterize anionic carrier kinetics. Furthermore it is suggested that estrone-3-sulfate may be used to identify compounds...... which may interact on anionic carriers....

  1. Carrier sense data highway system

    Science.gov (United States)

    Frankel, Robert

    1984-02-14

    A data transmission system includes a transmission medium which has a certain propagation delay time over its length. A number of data stations are successively coupled to the transmission medium for communicating with one another. Each of the data stations includes a transmitter for originating signals, each signal beginning with a carrier of a duration which is at least the propagation delay time of the transmission medium. Each data station also includes a receiver which receives other signals from other data stations and inhibits operation of the transmitter at the same data station when a carrier of another signal is received.

  2. Study on the influence of rutile nano-TiO2 on performance of CaSO4 whisker/PP-R resin composite%金红石型纳米TiO2对CaSO4晶须/PP-R树脂复合材料性能的影响

    Institute of Scientific and Technical Information of China (English)

    邹敏; 王琪琳

    2009-01-01

    以金红石型纳米TiO2为添加剂改善了CaSO4晶须/PP-R树脂复合材料的各项性能,并研究了金红石型纳米TiO2对PP-R树脂的力学性能、耐热性能和紫外老化性能的影响.研究结果表明:由于纳米TiO2和CaSO4晶须的协同作用,添加纳米TiO2后可进一步提高CaSO4晶须/PP-R树脂复合材料的力学性能和耐热性能;金红石纳米TiO2的加入可以大幅度提高PP-R树脂的耐紫外老化性能,添加5%纳米TiO2后的CaSO4晶须/PP-R树脂复合材料经紫外辐射72 d后,其拉伸强度仅下降了0.36MPa,冲击强度仅下降了0.36kJ·m-2,熔融温度仅下降了5.4℃;而未添加纳米TiO2的CaSO4晶须/PP-R树脂复合材料的拉伸强度下降了1.96MPa,冲击强度下降了1.47kJ·m-2,熔融温度下降了18.6℃.%The performances of CaSO4 whisker/PP-R resin composites, such as the mechanics performance, heat performance and ultraviolet aging performance, had been improved by adding rutile nanometer titanium dioxide. The results showed that adding the rutile nano-TiO2 can improve the performances of CaSO4 whisker/PP-R resin composite farther than adding CaSO4 whisker only because of the cooperation of two stuffs. The results also showed the ultraviolet aging performance of CaSO4 whisker/PP-R resin composite adding 5% can be improved greatly. The rutile nano-TiO2/CaSO4 whisker/PP-R resin composite radiated by UV after 72days, it's tensile strength was 0. 36MPa, Intensity of impact was 0. 36KJ·m-2 and it' s softening point was 5. 4℃. But the CaSO4 whisker/PP-R resin composite radiated by UV after 72days, it's tensile strength was 1.96MPa, Intensity of impact was 1.46KJ·m-2 and it's softening point cut was 18. 6℃.

  3. Injection deep level transient spectroscopy: An improved method for measuring capture rates of hot carriers in semiconductors

    International Nuclear Information System (INIS)

    An improved method for measuring the cross sections for carrier trapping at defects in semiconductors is described. This method, a variation of deep level transient spectroscopy (DLTS) used with bipolar transistors, is applied to hot carrier trapping at vacancy-oxygen, carbon-oxygen, and three charge states of divacancy centers (V2) in n- and p-type silicon. Unlike standard DLTS, we fill traps by injecting carriers into the depletion region of a bipolar transistor diode using a pulse of forward bias current applied to the adjacent diode. We show that this technique is capable of accurately measuring a wide range of capture cross sections at varying electric fields due to the control of the carrier density it provides. Because this technique can be applied to a variety of carrier energy distributions, it should be valuable in modeling the effect of radiation-induced generation-recombination currents in bipolar devices

  4. Injection deep level transient spectroscopy: An improved method for measuring capture rates of hot carriers in semiconductors

    Science.gov (United States)

    Fleming, R. M.; Seager, C. H.; Lang, D. V.; Campbell, J. M.

    2015-07-01

    An improved method for measuring the cross sections for carrier trapping at defects in semiconductors is described. This method, a variation of deep level transient spectroscopy (DLTS) used with bipolar transistors, is applied to hot carrier trapping at vacancy-oxygen, carbon-oxygen, and three charge states of divacancy centers (V2) in n- and p-type silicon. Unlike standard DLTS, we fill traps by injecting carriers into the depletion region of a bipolar transistor diode using a pulse of forward bias current applied to the adjacent diode. We show that this technique is capable of accurately measuring a wide range of capture cross sections at varying electric fields due to the control of the carrier density it provides. Because this technique can be applied to a variety of carrier energy distributions, it should be valuable in modeling the effect of radiation-induced generation-recombination currents in bipolar devices.

  5. Injection deep level transient spectroscopy: An improved method for measuring capture rates of hot carriers in semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, R. M.; Seager, C. H.; Lang, D. V.; Campbell, J. M. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1415 (United States)

    2015-07-07

    An improved method for measuring the cross sections for carrier trapping at defects in semiconductors is described. This method, a variation of deep level transient spectroscopy (DLTS) used with bipolar transistors, is applied to hot carrier trapping at vacancy-oxygen, carbon-oxygen, and three charge states of divacancy centers (V{sub 2}) in n- and p-type silicon. Unlike standard DLTS, we fill traps by injecting carriers into the depletion region of a bipolar transistor diode using a pulse of forward bias current applied to the adjacent diode. We show that this technique is capable of accurately measuring a wide range of capture cross sections at varying electric fields due to the control of the carrier density it provides. Because this technique can be applied to a variety of carrier energy distributions, it should be valuable in modeling the effect of radiation-induced generation-recombination currents in bipolar devices.

  6. OXYGEN-18 + OXYGEN-18 Reactions.

    Science.gov (United States)

    Yuan, Ren-Feng

    Cross sections for the ^{18 }O + ^{18}O reactions (fusion, inelastic excitation and transfer reactions) have been determined in the range 6.73 <=q E_{c.m}<=q 13.24 MeV by measuring the low-lying gamma-ray transitions in the residual nuclei with a high resolution Ge detector. A statistical model calculation of the populations of the residual nuclear states was employed in deducing cross sections from the measured gamma -yields. gamma-ray angular distributions were determined at E_{lab} = 20.0 MeV. The total fusion cross sections were compared with an IWBC calculation employing a parameter set obtained from fitting elastic scattering data. The interaction barrier shape has been obtained by means of the BKN inversion procedure and compared with the barriers for other oxygen isotopes. The inelastic scattering cross section and the two-neutron transfer reaction cross section are reproduced well by the DWBA approach.

  7. Hot carrier degradation in semiconductor devices

    CERN Document Server

    2015-01-01

    This book provides readers with a variety of tools to address the challenges posed by hot carrier degradation, one of today’s most complicated reliability issues in semiconductor devices.  Coverage includes an explanation of carrier transport within devices and book-keeping of how they acquire energy (“become hot”), interaction of an ensemble of colder and hotter carriers with defect precursors, which eventually leads to the creation of a defect, and a description of how these defects interact with the device, degrading its performance. • Describes the intricacies of hot carrier degradation in modern semiconductor technologies; • Covers the entire hot carrier degradation phenomenon, including topics such as characterization, carrier transport, carrier-defect interaction, technological impact, circuit impact, etc.; • Enables detailed understanding of carrier transport, interaction of the carrier ensemble with the defect precursors, and an accurate assessment of how the newly created defects imp...

  8. Production of an accelerated oxygen-14 beam

    CERN Document Server

    Powell, J; Cerny, J

    2003-01-01

    BEARS is an ongoing project to provide a light-ion radioactive-beam capability at the 88-Inch Cyclotron at LBNL. Light radioactive isotopes are produced at a 10 MeV proton medical cyclotron, transported 350 m via a high-speed gas transport capillary, cryogenically separated, and injected into the 88-Inch Cyclotron's ion source. The first radioactive beam successfully accelerated was carbon-11 and beams of intensity more than 10 sup 8 ions/s have been utilized for experiments. Development of oxygen-14 as the second BEARS beam presented considerable technical challenges, both due to its short half-life of 71 s and the radiation chemistry of oxygen in the target. The usual techniques developed for medical uses of oxygen-15 involve the addition of significant amounts of carrier oxygen, something that would overload the ion source. As a solution, oxygen-14 is produced as water in a carrier-free form, and is chemically converted in two steps to carbon dioxide, a form readily usable by the BEARS. This system has bee...

  9. Effect of Ash on Oxygen Carriers for the Application of Chemical Looping Combustion to a High Carbon Char Effet des cendres sur l’activité des porteurs d’oxygène dans la combustion du charbon en boucle chimique

    Directory of Open Access Journals (Sweden)

    Rubel A.

    2011-02-01

    Full Text Available The application of Chemical Looping Combustion (CLC to solid fuels is being investigated at the University of Kentucky, Center for Applied Energy Research (CAER with the aim of the development of a Pressurized Chemical Looping Combustion/Gasification (PCLC/G process for the generation of electricity from coal. One important aspect of the CLC of solid fuel is the understanding of the effect of ash on the reactivity of Oxygen Carriers (OCs. The effect of ash on the redox capabilities of two different iron oxide OCs and on their ability to oxidize coal char was studied. To determine the effect of ash on the reactivity and recycle of the OCs through multiple redox cycles, fly ash from a coal-fired power plant was used. These experiments were performed in a TGMS system using 500 mg of ash/OC mixtures containing different ash concentrations up to 75%. The reducing gas was composed of 10% H2, 15% CO, 20% CO2, and a balance of Ar and the oxidizing gas was 20% O2 in Ar. Oxidation/reductions were carried to near completion. The ash was found to contain OC activity related to inherent iron present in the ash confirmed by XRD. This resulted in increased weight gain/loss on oxidation/reduction. The rate of oxidation/reduction increased with ash concentration due to increased porosity of the OC/ash mixture and better access of the reactive gases to the OC target sites. The two OCs were then used to combust a beneficiated coal char in the TGMS with the only oxygen supplied by an iron oxide OC. The starting mixture was 10% char and 90% of one of two OCs studied. The spent material containing reduced OC and ash was re-oxidized and 10% more char was added for a second reduction of the OC and oxidation of the added char. This procedure was repeated for 5 cycles increasing the ash concentrations from 5 to 25% in the char/ash/OC mixture. Carbon removal was 92 to 97.8 and 97.3 to 99.7% for the two different iron oxide OCs tested. Ash was not detrimental to the

  10. Effect of oxygen on the response of a constant-current 63Ni electron-capture detector

    International Nuclear Information System (INIS)

    A constant-current electron-capture detector (ECD) with a 63Ni ionization cell has been used in a study of the effect of oxygen in nitrogen carrier gas on its response to several compounds. Because of the greatly increased linear dynamic range and the high temperature capabilities of this instrument, oxygen contamination of the carrier gas was found to be much less harmful to the chromatogram baseline than had been previously reported for earlier ECD models. Measurements of the changes in the molar responses of several compounds caused by the addition of up to 2000 ppm of oxygen to the nitrogen carrier gas have been made. For the chlorinated hydrocarbons studied, an effect of oxygen on their molar responses was observed only with the highest oxygen dopings. Anthracene behaved differently, showing an increased molar response at very low levels of oxygen doping. These results suggest that constant-current ECD analyses of polynuclear aromatics may be very sensitive to uncontrolled oxygen contamination of carrier gas, while those of halocarbons will not. For 1-chlorobutane a greatly enhanced response factor is caused by doping of the carrier gas with large amounts of oxygen. As this effect is observed at high detector temperatures where the baseline frequency is only moderately impared by oxygen, oxygen doping is suggested as a means of improving the ECD sensitivity to molecules that have only one or a few halogen atoms. Two reaction mechanisms are proposed to account for the oxygen effects observed. (Auth.)

  11. Fatigue reliability for LNG carrier

    Institute of Scientific and Technical Information of China (English)

    Xiao Taoyun; Zhang Qin; Jin Wulei; Xu Shuai

    2011-01-01

    The procedure of reliability-based fatigue analysis of liquefied natural gas (LNG) carrier of membrane type under wave loads is presented. The stress responses of the hotspots in regular waves with different wave heading angles and wave lengths are evaluated by global ship finite element method (FEM). Based on the probabilistic distribution function of hotspots' short-term stress-range using spectral-based analysis, Weibull distribution is adopted and discussed for fitting the long-term probabilistic distribution of stress-range. Based on linear cumulative damage theory, fatigue damage is characterized by an S-N relationship, and limit state function is established. Structural fatigue damage behavior of several typical hotspots of LNG middle ship section is clarified and reliability analysis is performed. It is believed that the presented results and conclusions can be of use in calibration for practical design and initial fatigue safety evaluation for membrane type LNG carrier.

  12. Gemini surfactants as gene carriers

    Directory of Open Access Journals (Sweden)

    Teresa Piskorska

    2010-03-01

    Full Text Available Gemini surfactants are a new class of amphiphilic compounds built from two classic surfactant moieties bound together by a special spacer group. These compounds appear to be excellent for creating complexes with DNA and are effective in mediating transfection. Thanks to their construction, DNA carrier molecules built from gemini surfactants are able to deliver genes to cells of almost any DNA molecule size, unattainable when using viral gene delivery systems. Moreover, they are much safer for living organisms.

  13. Preventative maintenance of straddle carriers

    Directory of Open Access Journals (Sweden)

    Si Li

    2015-02-01

    Full Text Available Background: Robotic vehicles such as straddle carriers represent a popular form of cargo handling amongst container terminal operators.Objectives: The purpose of this industry-driven study is to model preventative maintenance (PM influences on the operational effectiveness of straddle carriers.Method: The study employs historical data consisting of 21 273 work orders covering a 27-month period. Two models are developed, both of which forecast influences of PM regimes for different types of carrier.Results: The findings of the study suggest that the reliability of the straddle fleet decreases with increased intervals of PM services. The study also finds that three factors – namely resources, number of new straddles, and the number of new lifting work centres – influence the performances of straddles.Conclusion: The authors argue that this collaborative research exercise makes a significant contribution to existing supply chain management literature, particularly in the area of operations efficiency. The study also serves as an avenue to enhance relevant management practice.

  14. Home Oxygen Therapy

    Science.gov (United States)

    ... Oxygen Therapy Font: Aerosol Delivery Oxygen Resources Immunizations Pollution Nutrition Exercise Coming Of Age Older Adults Allergy ... oxygen is so cold it can hurt your skin. Keep a fire extinguisher close by, and let ...

  15. The recent advances on carrier materials for microencapsulating lipophilic cores

    Directory of Open Access Journals (Sweden)

    JIN Minfeng

    2014-12-01

    Full Text Available Lipophilic ingredients,such as polyunsaturated fatty acids,play an important role in industrialized foods to fortify the nutrients.However,these materials are normally sensitive to oxygen,light or heat to be oxidized,and hard to flow and mix within the bulk food due to the hydrophobic nature.Microencapsulation of lipophilic materials could effectively extend their shelf lives,mask unsatisfied flavors,change their physicochemical properties,and enhance the mixing capacities.This work reviewed the different carrier materials applied in microencapsulating the lipophilic ingredients,and discussed their characteristics and effects on encapsulation efficiencies and release profiles of lipophilic cores.

  16. Responsible implementation of expanded carrier screening

    Science.gov (United States)

    Henneman, Lidewij; Borry, Pascal; Chokoshvili, Davit; Cornel, Martina C; van El, Carla G; Forzano, Francesca; Hall, Alison; Howard, Heidi C; Janssens, Sandra; Kayserili, Hülya; Lakeman, Phillis; Lucassen, Anneke; Metcalfe, Sylvia A; Vidmar, Lovro; de Wert, Guido; Dondorp, Wybo J; Peterlin, Borut

    2016-01-01

    This document of the European Society of Human Genetics contains recommendations regarding responsible implementation of expanded carrier screening. Carrier screening is defined here as the detection of carrier status of recessive diseases in couples or persons who do not have an a priori increased risk of being a carrier based on their or their partners' personal or family history. Expanded carrier screening offers carrier screening for multiple autosomal and X-linked recessive disorders, facilitated by new genetic testing technologies, and allows testing of individuals regardless of ancestry or geographic origin. Carrier screening aims to identify couples who have an increased risk of having an affected child in order to facilitate informed reproductive decision making. In previous decades, carrier screening was typically performed for one or few relatively common recessive disorders associated with significant morbidity, reduced life-expectancy and often because of a considerable higher carrier frequency in a specific population for certain diseases. New genetic testing technologies enable the expansion of screening to multiple conditions, genes or sequence variants. Expanded carrier screening panels that have been introduced to date have been advertised and offered to health care professionals and the public on a commercial basis. This document discusses the challenges that expanded carrier screening might pose in the context of the lessons learnt from decades of population-based carrier screening and in the context of existing screening criteria. It aims to contribute to the public and professional discussion and to arrive at better clinical and laboratory practice guidelines. PMID:26980105

  17. Spacelab carrier complement thermal design and performance

    Science.gov (United States)

    Bancroft, S.; Key, R.; Kittredge, S.

    1992-01-01

    The present discussion of the Spacelab carrier complement, which encompasses a Module Carrier, a Module-Pallet Carrier, and a Multiplexer/Demultiplexer Pallet, gives attention to both active and passive thermal performance capabilities, and presents ground testing and analytical results obtained to date. An account is given of the prospective use of a Spacelab Multipurpose Experiment Support Structure.

  18. 7 CFR 33.4 - Carrier.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Carrier. 33.4 Section 33.4 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.4 Carrier. Carrier means any common...

  19. 49 CFR 376.22 - Exemption for private carrier leasing and leasing between authorized carriers.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Exemption for private carrier leasing and leasing... MOTOR CARRIER SAFETY REGULATIONS LEASE AND INTERCHANGE OF VEHICLES Exemptions for the Leasing Regulations § 376.22 Exemption for private carrier leasing and leasing between authorized carriers....

  20. Nanoporous nanocrystalline monoclinic zirconia for luminescent oxygen sensors

    Science.gov (United States)

    Fidelus, Janusz D.; Zhou, Wuzong; Tenderenda, Tadeusz; Nasiłowski, Tomasz

    2015-09-01

    In this work we present a nanocrystalline monoclinic ZrO2 with large free volumen open towards the nanocrystals surface dedicated for optical oxygen sensors. Nanoporous zirconia nanopowder was fabricated in hydrothermal microwave-driven process followed by annealing at 800°C. Metal-coated optical fibers are proposed as a light carrier when the working temperature exceeds 500°C. The obtained results may also find application in luminescent fiber optic oxygen sensors.

  1. Carrier synchronization for STBC OFDM systems

    Institute of Scientific and Technical Information of China (English)

    Cai Jueping; Song Wentao; Li Zan; Ge Jianhua

    2005-01-01

    All-digital carrier synchronization strategies and algorithms for space-time block coding (STBC) orthogonal frequency division multiplexing (OFDM) are proposed in this paper. In our scheme, the continuous pilots (CP) are saved, and the complexity of carrier synchronization is reduced significantly by dividing the process into three steps. The coarse carrier synchronization and the fine carrier synchronization algorithms are investigated and analyzed in detail. Simulations show that the carrier can be locked into tracking mode quickly, and the residual frequency error satisfies the system requirement in both stationary and mobile environments.

  2. Investigating thermal donors in n-type Cz silicon with carrier density imaging

    Directory of Open Access Journals (Sweden)

    Yu Hu

    2012-09-01

    Full Text Available A new method to map the thermal donor concentration in silicon wafers using carrier density imaging is presented. A map of the thermal donor concentration is extracted with high resolution from free carrier density images of a silicon wafer before and after growth of thermal donors. For comparison, free carrier density mapping is also performed using the resistivity method together with linear interpolation. Both methods reveal the same distribution of thermal donors indicating that the carrier density imaging technique can be used to map thermal donor concentration. The interstitial oxygen concentration can also be extracted using the new method in combination with Wijaranakula's model. As part of this work, the lifetime at medium injection level is correlated to the concentration of thermal donors in the as-grown silicon wafer. The recombination rate is found to depend strongly on the thermal donor concentration except in the P-band region.

  3. Oxygen Transport Ceramic Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

    2005-11-01

    The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the current research, the electrical conductivity and Seebeck coefficient were measured as a function of temperature in air. Based on these measurements, the charge carrier concentration, net acceptor dopant concentration, activation energy of conduction and mobility were estimated. The studies on the fracture toughness of the LSFT and dual phase membranes at room temperature have been completed and reported previously. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affects the mechanical properties. To study the effect of temperature on the membranes when exposed to an inert environment, the membranes (LAFT and Dual phase) were heat treated at 1000 C in air and N{sub 2} atmosphere and hardness and fracture toughness of the membranes were studied after the treatment. The indentation method was used to find the fracture toughness and the effect of the heat treatment on the mechanical properties of the membranes. Further results on the investigation of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appears to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model will serve to study ''frozen'' profiles in patterned or composite membranes.

  4. Carrier frequencies, holomorphy and unwinding

    CERN Document Server

    Coifman, Ronald R; Wu, Hau-tieng

    2016-01-01

    We prove that functions of intrinsic-mode type (a classical models for signals) behave essentially like holomorphic functions: adding a pure carrier frequency $e^{int}$ ensures that the anti-holomorphic part is much smaller than the holomorphic part $ \\| P_{-}(f)\\|_{L^2} \\ll \\|P_{+}(f)\\|_{L^2}.$ This enables us to use techniques from complex analysis, in particular the \\textit{unwinding series}. We study its stability and convergence properties and show that the unwinding series can stabilize and show that the unwinding series can provide a high resolution time-frequency representation, which is robust to noise.

  5. Biocheese: A Food Probiotic Carrier

    Directory of Open Access Journals (Sweden)

    J. M. Castro

    2015-01-01

    Full Text Available This review describes some aspects related to the technological barriers encountered in the development and stability of probiotic cheeses. Aspects concerning the viability of probiotic cultures in this matrix are discussed and the potential of cheese as a biofunctional food carrier is analyzed, outlying some points related to health and safety. In general, the manufacture of probiotic cheese should have little change when compared with the elaboration of cheese in the traditional way. The physicochemical and technological parameters influencing the quality of these products have also to be measured so as to obtain a process optimization.

  6. Wuestite - a solar energy carrier

    Energy Technology Data Exchange (ETDEWEB)

    Weidenkaff, A.; Nueesch, P.; Wokaun, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Reller, A. [Hamburg Univ., Hamburg (Germany)

    1997-06-01

    Hydrogen is produced when Wuestite (Fe{sub 1-y}O) is oxidised by water. This reaction is part of a two-step thermochemical metal oxide cycle for the storage of solar energy in the form of chemical energy carriers, characterised by a high chemical potential. The reaction was studied in a tubular furnace with on-line gas analysis and further characterised in detail by DTA und high-temperature X-ray powder diffraction. The influence of non-stoichiometry, morphology and temperature on the mechanism and kinetics of the water-splitting reaction was determined. (author) 3 figs., tabs., 3 refs.

  7. Artificial oxygen transport protein

    Science.gov (United States)

    Dutton, P. Leslie

    2014-09-30

    This invention provides heme-containing peptides capable of binding molecular oxygen at room temperature. These compounds may be useful in the absorption of molecular oxygen from molecular oxygen-containing atmospheres. Also included in the invention are methods for treating an oxygen transport deficiency in a mammal.

  8. Influence of carrier filling ratio on the performance of moving bed biofilm reactor in treating coking wastewater.

    Science.gov (United States)

    Gu, Qiyuan; Sun, Tichang; Wu, Gen; Li, Mingyue; Qiu, Wei

    2014-08-01

    This study aims to evaluate the effect of carrier filling ratio on the performance of a moving bed biofilm reactor in degrading chemical oxygen demand, phenol, thiocyanate, and ammonia from coking wastewater at 20h of hydraulic retention time. The operational experiments under different carrier filling ratios ranging from 20% to 60% were investigated. The maximum removal efficiency of 89%, 99% and 99% for COD, phenol and thiocyanate, and minimum sensitivity to the increasing contaminants concentration in the influent were achieved at 50% carrier filling ratio. The Haldane competitive substrate inhibition kinetics model was used to describe the relationship between the oxygen uptake rate of ammonium oxidizers and the concentration of free ammonium. The highest biofilm microbial community functional diversity (Shannon's diversity index, H') and evenness (Shannon's evenness index, E') were obtained at 50% carrier filling ratio in all runs using a Biolog ECO microplate.

  9. Oxygen-enhanced combustion

    CERN Document Server

    Baukal, Charles E

    2013-01-01

    Combustion technology has traditionally been dominated by air/fuel combustion. However, two developments have increased the significance of oxygen-enhanced combustion-new technologies that produce oxygen less expensively and the increased importance of environmental regulations. Advantages of oxygen-enhanced combustion include less pollutant emissions as well as increased energy efficiency and productivity. Oxygen-Enhanced Combustion, Second Edition compiles information about using oxygen to enhance industrial heating and melting processes. It integrates fundamental principles, applications, a

  10. Carrier detection in xeroderma pigmentosum

    International Nuclear Information System (INIS)

    We were able to detect clinically normal carriers of xeroderma pigmentosum (XP) genes with coded samples of either peripheral blood lymphocytes or skin fibroblasts, using a cytogenetic assay shown previously to detect individuals with cancer-prone genetic disorders. Metaphase cells of phytohemagglutinin-stimulated T-lymphocytes from eight individuals who are obligate heterozygotes for XP were compared with those from nine normal controls at 1.3, 2.3, and 3.3 h after x-irradiation (58 R) during the G2 phase of the cell cycle. Lymphocytes from the XP heterozygotes had twofold higher frequencies of chromatid breaks or chromatid gaps than normal (P less than 10(-5)) when fixed at 2.3 or 3.3 h after irradiation. Lymphocytes from six XP homozygotes had frequencies of breaks and gaps threefold higher than normal. Skin fibroblasts from an additional obligate XP heterozygote, when fixed approximately 2 h after x-irradiation (68 R), had a twofold higher frequency of chromatid breaks and a fourfold higher frequency of gaps than fibroblasts from a normal control. This frequency of aberrations in cells from the XP heterozygote was approximately half that observed in the XP homozygote. The elevated frequencies of chromatid breaks and gaps after G2 phase x-irradiation may provide the basis of a test for identifying carriers of the XP gene(s) within known XP families

  11. Carrier localization in gallium nitride

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, C. [Lawrence Berkeley National Lab., CA (United States)][California Univ., Berkeley, CA (United States); Walukiewicz, W. [Lawrence Berkeley National Lab., CA (United States); Haller, E.E. [Lawrence Berkeley National Lab., CA (United States)][California Univ., Berkeley, CA (United States)] [and others

    1996-09-01

    In wide bandgap GaN, a large number of interesting and important scientific questions remain to be answered. For example, the large free electron concentration reaching 10{sup 19} to 10{sup 20} cm{sup - 3} in nominally undoped material are ascribed to intrinsic defects because no chemical impurity has been found at such high concentrations. According to theoretical models, a nitrogen vacancy acts as a donor but its formation energy is very large in n-type materials, making this suggestion controversial. We have investigated the nature of this yet unidentified donor at large hydrostatic pressure. Results from infrared reflection and Raman scattering indicate strong evidence for localization of free carriers by large pressures. The carrier density is drastically decreased by two orders of magnitude between 20 and 30 GPa. Several techniques provide independent evidence for results in earlier reports and present the first quantitative analysis. A possible interpretation of this effect in terms of the resonant donor level is presented.

  12. Silicon ball grid array chip carrier

    Science.gov (United States)

    Palmer, David W.; Gassman, Richard A.; Chu, Dahwey

    2000-01-01

    A ball-grid-array integrated circuit (IC) chip carrier formed from a silicon substrate is disclosed. The silicon ball-grid-array chip carrier is of particular use with ICs having peripheral bond pads which can be reconfigured to a ball-grid-array. The use of a semiconductor substrate such as silicon for forming the ball-grid-array chip carrier allows the chip carrier to be fabricated on an IC process line with, at least in part, standard IC processes. Additionally, the silicon chip carrier can include components such as transistors, resistors, capacitors, inductors and sensors to form a "smart" chip carrier which can provide added functionality and testability to one or more ICs mounted on the chip carrier. Types of functionality that can be provided on the "smart" chip carrier include boundary-scan cells, built-in test structures, signal conditioning circuitry, power conditioning circuitry, and a reconfiguration capability. The "smart" chip carrier can also be used to form specialized or application-specific ICs (ASICs) from conventional ICs. Types of sensors that can be included on the silicon ball-grid-array chip carrier include temperature sensors, pressure sensors, stress sensors, inertia or acceleration sensors, and/or chemical sensors. These sensors can be fabricated by IC processes and can include microelectromechanical (MEM) devices.

  13. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus

    DEFF Research Database (Denmark)

    Espinosa-Gongora, Carmen; Larsen, Niels; Schonning, Kristian;

    2016-01-01

    pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium...... microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate...

  14. Carriers of the astronomical 2175 ? extinction feature

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, J; Dai, Z; Ernie, R; Browning, N; Graham, G; Weber, P; Smith, J; Hutcheon, I; Ishii, H; Bajt, S; Floss, C; Stadermann, F

    2004-07-20

    The 2175 {angstrom} extinction feature is by far the strongest spectral signature of interstellar dust observed by astronomers. Forty years after its discovery the origin of the feature and the nature of the carrier remain controversial. The feature is enigmatic because although its central wavelength is almost invariant its bandwidth varies strongly from one sightline to another, suggesting multiple carriers or a single carrier with variable properties. Using a monochromated transmission electron microscope and valence electron energy-loss spectroscopy we have detected a 5.7 eV (2175 {angstrom}) feature in submicrometer-sized interstellar grains within interplanetary dust particles (IDPs) collected in the stratosphere. The carriers are organic carbon and amorphous silicates that are abundant and closely associated with one another both in IDPs and in the interstellar medium. Multiple carriers rather than a single carrier may explain the invariant central wavelength and variable bandwidth of the astronomical 2175 {angstrom} feature.

  15. Ultrafast carriers dynamics in filled-skutterudites

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Liang; Xu, Xianfan, E-mail: xxu@purdue.edu [School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Salvador, James R. [Chemical and Materials Systems Laboratory, GM Global R and D, Warren, Michigan 48090 (United States)

    2015-06-08

    Carrier dynamics of filled-skutterudites, an important class of thermoelectric materials, is investigated using ultrafast optical spectroscopy. By tuning the wavelength of the probe laser, charge transfers at different electronic energy levels are interrogated. Analysis based on the Kramers-Kronig relation explains the complex spectroscopy data, which is mainly due to band filling caused by photo-excited carriers and free carrier absorption. The relaxation time of hot carriers is found to be about 0.4–0.6 ps, depending on the electronic energy level, and the characteristic time for carrier-phonon equilibrium is about 0.95 ps. These studies of carrier dynamics, which fundamentally determines the transport properties of thermoelectric material, can provide guidance for the design of materials.

  16. Ultrafast carriers dynamics in filled-skutterudites

    Science.gov (United States)

    Guo, Liang; Xu, Xianfan; Salvador, James R.

    2015-06-01

    Carrier dynamics of filled-skutterudites, an important class of thermoelectric materials, is investigated using ultrafast optical spectroscopy. By tuning the wavelength of the probe laser, charge transfers at different electronic energy levels are interrogated. Analysis based on the Kramers-Kronig relation explains the complex spectroscopy data, which is mainly due to band filling caused by photo-excited carriers and free carrier absorption. The relaxation time of hot carriers is found to be about 0.4-0.6 ps, depending on the electronic energy level, and the characteristic time for carrier-phonon equilibrium is about 0.95 ps. These studies of carrier dynamics, which fundamentally determines the transport properties of thermoelectric material, can provide guidance for the design of materials.

  17. Simulation Experiments on the Reaction of CH4-CaSO4 and Its Carbon Kinetic Isotope Fractionation%甲烷和硫酸钙反应体系热模拟实验及碳同位素分馏研究

    Institute of Scientific and Technical Information of China (English)

    岳长涛; 李术元; 丁康乐; 钟宁宁

    2005-01-01

    Thermochemical sulfate reduction (TSR) in geological deposits can account for the accumulation of H2S in deep sour gas reservoirs. In this paper, thermal simulation experiments on the reaction of CH4-CaSO4 were carried out using an autoclave at high temperatures and high pressures. The products were characterized with analytical methods including carbon isotope analysis. It is found that the reaction can proceed to produce H2S, H2O and CaCO3 as the main products. Based on the experimental results, the carbon kinetic isotope fractionation was investigated, and the value of Ki (kinetic isotope effect) was calculated. The results obtained in this paper can provide useful information to explain the occurrence of H2S in deep carbonate gas reservoirs.

  18. Oxygen chemisorption cryogenic refrigerator

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1987-01-01

    The present invention relates to a chemisorption compressor cryogenic refrigerator which employs oxygen to provide cooling at 60 to 100 K. The invention includes dual vessels containing an oxygen absorbent material, alternately heated and cooled to provide a continuous flow of high pressure oxygen, multiple heat exchangers for precooling the oxygen, a Joule-Thomson expansion valve system for expanding the oxygen to partially liquefy it and a liquid oxygen pressure vessel. The primary novelty is that, while it was believed that once oxygen combined with an element or compound the reaction could not reverse to release gaseous oxygen, in this case oxygen will indeed react in a reversible fashion with certain materials and will do so at temperatures and pressures which make it practical for incorporation into a cryogenic refrigeration system.

  19. Global Telecommunications Services: Strategies of Major Carriers

    OpenAIRE

    Jerry Mccreary; William R. Boulton; Chetan Sankar

    1993-01-01

    The globalization of telecommunications markets is of primary concern for today’s large telecommunications carriers. International business telecommunications is growing at a rate twice that of domestic traffic. Multi-national customers with offices around the world are demanding integrated solutions to their telecommunications needs. As telecommunication carriers respond to these customers’ needs, the carriers are beginning to expand outside their national boundaries. This paper identifi...

  20. Secure quantum carriers for quantum state sharing

    OpenAIRE

    Karimipour, Vahid; Marvian, Milad

    2010-01-01

    We develop the concept of quantum carrier and show that messages can be uploaded and downloaded from this carrier and while in transit, these messages are hidden from external agents. We explain in detail the working of the quantum carrier for different communication tasks, including quantum key distribution, classical secret and quantum state sharing among a set of $n$ players according to general threshold schemes. The security of the protocol is discussed and it is shown that only the legi...

  1. Heterozygote advantage in Tay-Sachs carriers?

    OpenAIRE

    Spyropoulos, B; Moens, P B; Davidson, J.; Lowden, J. A.

    1981-01-01

    Chi-square analyses of new data as well as data previously reported by Myrianthopoulos have shown that grandparents of Tay-Sachs carriers die from proportionally the same causes as grandparents of noncarriers. It is unlikely that there is any advantage to being a Tay-Sachs carrier insofar as resistance to tuberculosis is concerned. Our results are further evidence to support Fraikor's claim that the high carrier frequency of the allele in Ashkenazi Jews is probably caused by a combination of ...

  2. Carriers by chemical vapor deposition

    Science.gov (United States)

    Mronga, Norbert; Adel, J.; Czech, Erwin

    1990-07-01

    Printed materials are affecting people's lives in a variety of ways and to a constantly increasing extent, both in the private and in the business spheres. In particular, the predicted reduction of printed materials resulting from electronic data processing - the so-called "paperless electronic office" - has not occured, indeed quite the reverse. In recent years electrophotographic reprography has established itself successfully as a competitor to conventional printing processes. In the office a photocopier is now a part of the standard equipment. Because of BASF's traditional intensive involvement with pigments and colored printing inks its interest in new technologies in these areas is especially great. BASF has therefore been engaged in research on carriers for some years now.

  3. The Kinetics of Carrier Transport Inhibition

    DEFF Research Database (Denmark)

    Rosenberg, T.; Wilbrandt, Robert Walter

    1962-01-01

    The kinetical treatment of enzymatic carrier transports as given in previous communications has been extended to conditions of inhibition. Various possible types of inhibitors have been considered differing in the site of attack (enzyme or carrier), in the mode of action (competing with the subst......The kinetical treatment of enzymatic carrier transports as given in previous communications has been extended to conditions of inhibition. Various possible types of inhibitors have been considered differing in the site of attack (enzyme or carrier), in the mode of action (competing...

  4. CARRIER/CASK HANDLING SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    E.F. Loros

    2000-06-23

    The Carrier/Cask Handling System receives casks on railcars and legal-weight trucks (LWTs) (transporters) that transport loaded casks and empty overpacks to the Monitored Geologic Repository (MGR) from the Carrier/Cask Transport System. Casks that come to the MGR on heavy-haul trucks (HHTs) are transferred onto railcars before being brought into the Carrier/Cask Handling System. The system is the interfacing system between the railcars and LWTs and the Assembly Transfer System (ATS) and Canister Transfer System (CTS). The Carrier/Cask Handling System removes loaded casks from the cask transporters and transfers the casks to a transfer cart for either the ATS or CTS, as appropriate, based on cask contents. The Carrier/Cask Handling System receives the returned empty casks from the ATS and CTS and mounts the casks back onto the transporters for reshipment. If necessary, the Carrier/Cask Handling System can also mount loaded casks back onto the transporters and remove empty casks from the transporters. The Carrier/Cask Handling System receives overpacks from the ATS loaded with canisters that have been cut open and emptied and mounts the overpacks back onto the transporters for disposal. If necessary, the Carrier/Cask Handling System can also mount empty overpacks back onto the transporters and remove loaded overpacks from them. The Carrier/Cask Handling System is located within the Carrier Bay of the Waste Handling Building System. The system consists of cranes, hoists, manipulators, and supporting equipment. The Carrier/Cask Handling System is designed with the tooling and fixtures necessary for handling a variety of casks. The Carrier/Cask Handling System performance and reliability are sufficient to support the shipping and emplacement schedules for the MGR. The Carrier/Cask Handling System interfaces with the Carrier/Cask Transport System, ATS, and CTS as noted above. The Carrier/Cask Handling System interfaces with the Waste Handling Building System for building

  5. The effect of oxygenation on the radiation hardness of silicon studied by surface photovoltage method

    CERN Document Server

    Härkönen, J; Tuovinen, E; Lassila-Perini, K M; Mehtälä, P; Nummela, S; Nysten, J; Heikkilä, P; Ovchinnikov, V; Palokangas, M; Ylikoski, M; Palmu, L; Kallijärvi, S; Alanko, T; Laitinen, P

    2002-01-01

    The effect of oxygenation on the radiation hardness of silicon detectors was studied. Oxygen-enriched and standard float-zone silicon pin-diodes and oxidized samples were processed and irradiated with 15-MeV protons. After the irradiations, the surface photovoltage (SPV) method was applied to extract minority carrier diffusion lengths of the silicon samples. Adding oxygen to silicon was found to improve the radiation hardness of silicon. The effect was visible in minority carrier diffusion lengths as well as in reverse bias leakage currents. The suitability of SPV method for characterizing irradiated silicon samples was proved. 14 Refs.

  6. Biogeochemistry: Oxygen burrowed away

    NARCIS (Netherlands)

    Meysman, F.J.R.

    2014-01-01

    Multicellular animals probably evolved at the seafloor after a rise in oceanic oxygen levels. Biogeochemical model simulations suggest that as these animals started to rework the seafloor, they triggered a negative feedback that reduced global oxygen.

  7. Oxygen transport membrane

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof.......The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof....

  8. Hyperbaric oxygen therapy

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002375.htm Hyperbaric oxygen therapy To use the sharing features on this page, please enable JavaScript. Hyperbaric oxygen therapy uses a special pressure chamber to increase ...

  9. Oxygen evolution reaction catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  10. Carrier-carrier relaxation kinetics in quantum well semiconductor structures with nonparabolic energy bands

    DEFF Research Database (Denmark)

    Dery, H.; Tromborg, Bjarne; Eisenstein, G.

    2003-01-01

    We describe carrier-carrier scattering dynamics in an inverted quantum well structure including the nonparabolic nature of the valance band. A solution of the semiconductor Bloch equations yields strong evidence to a large change in the temporal evolution of the carrier distributions compared...

  11. Effect of oxygen vacancy defect on the magnetic properties of Co-doped ZnO

    Institute of Scientific and Technical Information of China (English)

    Weng Zhen-Zhen; Zhang Jian-Min; Huang Zhi-Gao; Lin Wen-Xiong

    2011-01-01

    The influence of oxygen vacancy on the magnetism of Co-doped ZnO has been investigated by the first-principles calculations. It is suggested that oxygen vacancy and its location play crucial roles on the magnetic properties of Co-doped ZnO. The exchange coupling mechanism should account for the magnetism in Co-doped ZnO with oxygen vacancy and the oxygen vacancy is likely to be close to the Co atom. The oxygen vacancy (doping electrons) might be available for carrier mediation but is localized with a certain length and can strengthen the ferromagnetic exchange interaction between Co atoms.

  12. Inert carrier drying and coating process

    International Nuclear Information System (INIS)

    An inert carrier process is described for drying radioactive (particularly low level) waste material and for incorporating the dry material into a binder matrix from which the dried material will not be leached. Experimental details, and examples of the carrier and binder materials, are given. (U.K.)

  13. 14 CFR Section 04 - Air Carrier Groupings

    Science.gov (United States)

    2010-01-01

    ... Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC... upon their level of operations and the nature of these operations. In order to determine the level of... carrier's level of operations passes the upper or lower limit of its currently assigned carrier...

  14. Providing resilience for carrier ethernet multicast traffic

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Zhang, Jiang;

    2009-01-01

    This paper presents an overview of the Carrier Ethernet technology with specific focus on resilience. In particular, we detail how multicast traffic, which is essential for e.g. IPTV can be protected. We present Carrier Ethernet resilience methods for linear and ring networks and show by simulation...

  15. Modeling of Carrier Dynamics in Electroabsorption Modulators

    DEFF Research Database (Denmark)

    Højfeldt, Sune

    2002-01-01

    and a phenomenological model for the carrier sweep-out dynamics, we investigate all-optical wavelength conversion, all-optical signal regeneration, and all-optical demultiplexing. A detailed drift-diffusion type model for the sweerp-out of photo-excited carriers in electroabsorption modulators is presented. We use...... the model to calclulate absorption spectra and steady-state carrier distributions in different modulator structures. This allows us to investigate a number of important properties of electroabsorption modulators, such as the electroabsorption effect and th saturation properties. We also investigate...... the influence that carrier recapture has on the device properties, and we discuss the recapture process on a more fundamental level. The model is also used to investigate in detail the carrier sweep-out process in electroabsorption modulators. We investigate how the intrinsic-region width, the separate...

  16. Selection of Carrier Waveforms for PWM Inverter

    Institute of Scientific and Technical Information of China (English)

    陈国呈; 屈克庆; 许春雨; 孙承波

    2003-01-01

    In this paper the influence of different carrier waveforms upon the output characteristics of PWM inverter is described in detail. When a triangular carrier waveform is used in hard-switching PWM inverters, harmonics exist in the neighborhood of the output frequency of the inverter output voltage and current due to the dead time. The triangular carrier waveform used in soft-switching PWM inverter will cause difficulties in controlling resonance-trigger time, higher loss in the resonant circuit, and less utilization of the DC bus voltage. If a sawtooth carrier is used in hard-switching PWM inverter, there will be severe distortion in the current waveform. When sawtooth carriers with alternate positive and negative slopes are used in soft-switching PWM inverters, the resonancetrigger time is easy to control, and distortion in the output voltage and current caused by the dead time will not appear.

  17. Redox homeostasis in plants under abiotic stress: role of electron carriers, energy metabolism mediators and proteinaceous thiols

    OpenAIRE

    Kapoor, Dhriti; Sharma, Resham; Handa, Neha; Kaur, Harpreet; Rattan, Amandeep; Yadav, Poonam; Gautam, Vandana; Kaur, Ravdeep; Bhardwaj, Renu

    2015-01-01

    Contemporaneous presence of both oxidized and reduced forms of electron carriers is mandatory in efficient flux by plant electron transport cascades. This requirement is considered as redox poising that involves the movement of electron from multiple sites in respiratory and photosynthetic electron transport chains to molecular oxygen. This flux triggers the formation of superoxide, consequently give rise to other reactive oxygen species (ROS) under adverse environmental conditions like droug...

  18. Methanol as an energy carrier

    Energy Technology Data Exchange (ETDEWEB)

    Biedermann, P.; Grube, T.; Hoehlein, B. (eds.)

    2006-07-01

    For the future, a strongly growing energy demand is expected in the transport sector worldwide. Economically efficient oil production will run through a maximum in the next decade. Higher fuel prices and an environmentally desirable reduction of emissions will increase the pressure for reducing fuel consumption and emissions in road traffic. These criteria show the urgent necessity of structural changes in the fuel market. Due to its advantages concerning industrial-scale production, storage and global availability, methanol has the short- to medium-term potential for gaining increased significance as a substitution product in the energy market. Methanol can be produced both from fossil energy sources and from biomass or waste materials through the process steps of synthesis gas generation with subsequent methanol synthesis. Methanol has the potential to be used in an environmentally friendly manner in gasoline/methanol mixtures for flexible fuel vehicles with internal combustion engines and in diesel engines with pure methanol. Furthermore, it can be used in fuel cell vehicles with on-board hydrogen production in direct methanol fuel cell drives, and in stationary systems for electricity and heat generation as well as for hydrogen production. Finally, in portable applications it serves as an energy carrier for electric power generation. In this book, the processes for the production and use of methanol are presented and evaluated, markets and future options are discussed and issues of safety and environmental impacts are addressed by a team of well-known authors. (orig.)

  19. Brain Oxygenation Monitoring.

    Science.gov (United States)

    Kirkman, Matthew A; Smith, Martin

    2016-09-01

    A mismatch between cerebral oxygen supply and demand can lead to cerebral hypoxia/ischemia and deleterious outcomes. Cerebral oxygenation monitoring is an important aspect of multimodality neuromonitoring. It is increasingly deployed whenever intracranial pressure monitoring is indicated. Although there is a large body of evidence demonstrating an association between cerebral hypoxia/ischemia and poor outcomes, it remains to be determined whether restoring cerebral oxygenation leads to improved outcomes. Randomized prospective studies are required to address uncertainties about cerebral oxygenation monitoring and management. This article describes the different methods of monitoring cerebral oxygenation, their indications, evidence base, limitations, and future perspectives. PMID:27521197

  20. Optoelectronic characterization of carrier extraction in a hot carrier photovoltaic cell structure

    Science.gov (United States)

    Dimmock, James A. R.; Kauer, Matthias; Smith, Katherine; Liu, Huiyun; Stavrinou, Paul N.; Ekins-Daukes, Nicholas J.

    2016-07-01

    A hot carrier photovoltaic cell requires extraction of electrons on a timescale faster than they can lose energy to the lattice. We optically and optoelectronically characterize two resonant tunneling structures, showing their compatability with hot carrier photovoltaic operation, demonstrating structural and carrier extraction properties necessary for such a device. In particular we use time resolved and temperature dependent photoluminescence to determine extraction timescales and energy levels in the structures and demonstrate fast carrier extraction by tunneling. We also show that such devices are capable of extracting photo-generated electrons at high carrier densities, with an open circuit voltage in excess of 1 V.

  1. Effects of carrier-carrier scattering on population inversion in graphene under pulse photoexcitation

    Science.gov (United States)

    Satou, Akira; Ryzhii, Victor; Otsuji, Taiichi

    2015-01-01

    We study the carrier relaxation dynamics in intrinsic graphene after pulse photoexcitation and reveal effects of intraband carrier-carrier scattering on population inversion in the terahertz region, by conducting simulation based on the quasi-classical Boltzmann equation. It is demonstrated that by changing the dielectric constant of the surrounding materials the rate of carrier-carrier scattering can be controlled and the relaxation dynamics differs for cases with low and high dielectric constants. It is also found that the Pauli blocking of photogeneration in case of the pulse photoexcitation causes decrease in the photocarrier concentration and thus weakening of population inversion with higher dielectric constant.

  2. How Does Oxygen Therapy Work?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. How Does Oxygen Therapy Work? Oxygen therapy provides you with extra ... be delivered to your lungs in several ways. Oxygen Therapy Systems Oxygen is supplied in three forms: ...

  3. Electric Properties of Obsidian: Evidence for Positive Hole Charge Carriers

    Science.gov (United States)

    Nordvik, R.; Freund, F. T.

    2012-12-01

    The blackness of obsidian is due to the presence of oxygen anions in the valence state 1-, creating broad energy levels at the upper edge of the valence band, which absorb visible light over a wide spectral range. These energy states are associated with defect electrons in the oxygen anion sublattice, well-known from "smoky quartz", where Al substituting for Si captures a defect electron in the oxygen anion sublattice for charge compensation [1]. Such defect electrons, also known as positive holes, are responsible for the increase in electrical conductivity in igneous rocks when uniaxial stresses are applied, causing the break-up of pre-existing peroxy defects, Si-OO-Si [2]. Peroxy defects in obsidian cannot be so easily activated by mechanical stress because the glassy matrix will break before sufficiently high stress levels can be reached. If peroxy defects do exist, however, they can be studied by activating them thermally [3]. We describe experiments with rectangular slabs of obsidian with Au electrodes at both ends. Upon heating one end, we observe (i) a thermopotential and (ii) a thermocurrent developing at distinct temperatures around 250°C and 450°C, marking the 2-step break-up of peroxy bonds. [1] Schnadt, R., and Schneider, J.: The electronic structure of the trapped-hole center in smoky quartz, Zeitschrift Physik B Condensed Matter 11, 19-42, 1970. [2] Freund, F. T., Takeuchi, A., and Lau, B. W.: Electric currents streaming out of stressed igneous rocks - A step towards understanding pre-earthquake low frequency EM emissions, Physics and Chemistry of the Earth, 31, 389-396, 2006. [3] Freund, F., and Masuda, M. M.: Highly mobile oxygen hole-type charge carriers in fused silica, Journal Material Research, 8, 1619-1622, 1991.

  4. Carrier scattering in metals and semiconductors

    CERN Document Server

    Gantmakher, VF

    1987-01-01

    The transport properties of solids, as well as the many optical phenomena in them are determined by the scattering of current carriers. ``Carrier Scattering in Metals and Semiconductors'' elucidates the state of the art in the research on the scattering mechanisms for current carriers in metals and semiconductors and describes experiments in which these mechanisms are most dramatically manifested.The selection and organization of the material is in a form to prepare the reader to reason independently and to deal just as independently with available theoretical results and experimental

  5. High capacity carrier ethernet transport networks

    DEFF Research Database (Denmark)

    Rasmussen, Anders; Zhang, Jiang; Yu, Hao;

    2009-01-01

    Ethernet as a transport technology has, up to now, lacked the features such as network layer architecture, customer separation and manageability that carriers require for wide-scale deployment. However, with the advent of PBB-TE and T-MPLS, it is now possible to use Ethernet as a transport...... OAM functions, survivability and the increased bandwidth requirements of carrier class systems. This article provides an overview of PBB-TE and T-MPLS and demonstrates how IPTV services can be realized in the framework of Carrier Ethernet. In addition we provide a case study on performing bit error...

  6. ISRAEL’S NATIONAL WATER CARRIER

    OpenAIRE

    Nathan Cohen

    2008-01-01

    The National Water Carrier of Israel (Ha Movil Ha' Artzi). It is the main water project of Israel and its main task is to transfer water from the rainy north to the center and to the arid south. The National Water Carrier connects the Sea of Galilee with Israel's water system. The original goal was to provide irrigation water to Negev. Today 80% of the water is utilized for Israel's domestic consumption. Most of the water works in Israel are combined with the National Water Carrier for about...

  7. Ambient oxygen promotes tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Ho Joong Sung

    Full Text Available Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53-/- mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53-/- mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.

  8. Integrated turbomachine oxygen plant

    Science.gov (United States)

    Anand, Ashok Kumar; DePuy, Richard Anthony; Muthaiah, Veerappan

    2014-06-17

    An integrated turbomachine oxygen plant includes a turbomachine and an air separation unit. One or more compressor pathways flow compressed air from a compressor through one or more of a combustor and a turbine expander to cool the combustor and/or the turbine expander. An air separation unit is operably connected to the one or more compressor pathways and is configured to separate the compressed air into oxygen and oxygen-depleted air. A method of air separation in an integrated turbomachine oxygen plant includes compressing a flow of air in a compressor of a turbomachine. The compressed flow of air is flowed through one or more of a combustor and a turbine expander of the turbomachine to cool the combustor and/or the turbine expander. The compressed flow of air is directed to an air separation unit and is separated into oxygen and oxygen-depleted air.

  9. Atomic Oxygen Effects

    Science.gov (United States)

    Miller, Sharon K. R.

    2014-01-01

    Atomic oxygen, which is the most predominant species in low Earth orbit, is highly reactive and can break chemical bonds on the surface of a wide variety of materials leading to volatilization or surface oxidation which can result in failure of spacecraft materials and components. This presentation will give an overview of how atomic oxygen reacts with spacecraft materials, results of space exposure testing of a variety of materials, and examples of failures caused by atomic oxygen.

  10. Intraoral radiation carrier for edentulous patients

    International Nuclear Information System (INIS)

    The principles of fabricating an intraoral radioactive carrier have been described to treat malignant diseases of the oral cavity. The prosthesis provides consistent direction and fixation of the radioactive source into the same location

  11. Intraoral radiation carrier for edentulous patients

    Energy Technology Data Exchange (ETDEWEB)

    Sela, M.; Taicher, S.

    1983-12-01

    The principles of fabricating an intraoral radioactive carrier have been described to treat malignant diseases of the oral cavity. The prosthesis provides consistent direction and fixation of the radioactive source into the same location.

  12. Simulation of dual transponder carrier ranging measurements

    Institute of Scientific and Technical Information of China (English)

    Xiang-yu ZHAO; Xiao-jun JIN; Zhong-he JIN

    2009-01-01

    The most dominant error source for microwave ranging is the frequency instability of the oscillator that generates the carrier phase signal. The oscillator noise is very difficult to filter due to its extremely low frequency. A dual transponder carrier ranging method can effectively minimize the oscillator noise by combing the reference phase and the to-and-fro measurement phase from the same single oscillator. This method does not require an accurate time tagging system, since it extracts phases on the same satellite. This paper analyzes the dual transponder carrier ranging system by simulation of the phase measurements with comprehensive error models. Both frequency domain and time domain noise transfer characteristics were simulated to compare them with dual one-way ranging. The simulation results in the two domains conformed to each other and demonstrated that a high level of accuracy can also be achieved by use of the dual transponder carrier ranging system, with relatively simple instruments.

  13. Physician Fee Schedule Carrier Specific Files

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Centers for Medicare and Medicaid Services (CMS) has condensed all 56 Physician Fee Schedule (PFS) carrier specific pricing files into one zip file. It is...

  14. Measuring tissue oxygenation

    Science.gov (United States)

    Soyemi, Olusola O. (Inventor); Soller, Babs R. (Inventor); Yang, Ye (Inventor)

    2009-01-01

    Methods and systems for calculating tissue oxygenation, e.g., oxygen saturation, in a target tissue are disclosed. In some embodiments, the methods include: (a) directing incident radiation to a target tissue and determining reflectance spectra of the target tissue by measuring intensities of reflected radiation from the target tissue at a plurality of radiation wavelengths; (b) correcting the measured intensities of the reflectance spectra to reduce contributions thereto from skin and fat layers through which the incident radiation propagates; (c) determining oxygen saturation in the target tissue based on the corrected reflectance spectra; and (d) outputting the determined value of oxygen saturation.

  15. Solid state oxygen sensor

    Science.gov (United States)

    Garzon, F.H.; Brosha, E.L.

    1997-12-09

    A potentiometric oxygen sensor is formed having a logarithmic response to a differential oxygen concentration while operating as a Nernstian-type sensor. Very thin films of mixed conducting oxide materials form electrode services while permitting diffusional oxygen access to the interface between the zirconia electrolyte and the electrode. Diffusion of oxygen through the mixed oxide is not rate-limiting. Metal electrodes are not used so that morphological changes in the electrode structure do not occur during extended operation at elevated temperatures. 6 figs.

  16. Evaluating multicast resilience in carrier ethernet

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Zhang, Jiang;

    2010-01-01

    This paper gives an overview of the Carrier Ethernet technology with specific focus on resilience. In particular, we show how multicast traffic, which is essential for IPTV can be protected. We detail the ackground for resilience mechanisms and their control and e present Carrier Ethernet resilie...... resilience methods for linear nd ring networks. By simulation we show that the vailability of a multicast connection can be significantly increased by applying protection methods....

  17. Preparation and application of magnetic microsphere carriers

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bo; XING Jianmin; LIU Huizhou

    2007-01-01

    Magnetic microsphere carriers have received considerable attention,primarily because of their wide applications in the fields of biomedicine and bioengineering.In this paper,preparation methods,surface modification and application of magnetic carriers are reviewed.Emphasis will be placed on recent biological and biomedical developments and trends such as enzyme immobilization,cell isolation,protein purification,target drugs and DNA separation.

  18. Enhanced attached growth of microalgae Scenedesmus. LX1 through ambient bacterial pre-coating of cotton fiber carriers.

    Science.gov (United States)

    Zhuang, Lin-Lan; Azimi, Yaldah; Yu, Dawei; Wang, Wen-Long; Wu, Yin-Hu; Dao, Guo-Hua; Hu, Hong-Ying

    2016-10-01

    The role of bacteria/extracellular polymeric substances (EPS) coated carriers on attached microalgae growth in suspended-solid phase photobioreactor (sspBR) was assessed in this study. The results showed that pre-coating cotton with ambient bacteria and their EPS improved the attached microalgal growth by as much as 230% in terms of attached microalgae density. Additionally, the single cell dry weight, chemical composition and oxygen evolving activity of attached microalgae were significantly affected by the presence of bacteria/EPS coating on the cotton carriers. The protein content of microalgae cells cultivated in the ssPBRs with carriers coated by bacteria and sterilized bacteria were on average 26% and 15% more than uncoated carriers, respectively. Through absorbing and immobilizing nutrients from the bulk medium, the bacteria/EPS coating provided the attached microalgae with nitrogen/phosphorus for protein synthesis, especially during the late stages of batch cultivation. PMID:27416514

  19. Implementing oxygen control in chip-based cell and tissue culture systems.

    Science.gov (United States)

    Oomen, Pieter E; Skolimowski, Maciej D; Verpoorte, Elisabeth

    2016-09-21

    Oxygen is essential in the energy metabolism of cells, as well as being an important regulatory parameter influencing cell differentiation and function. Interest in precise oxygen control for in vitro cultures of tissues and cells continues to grow, especially with the emergence of the organ-on-a-chip and the desire to emulate in vivo conditions. This was recently discussed in this journal in a Critical Review by Brennan et al. (Lab Chip (2014). DOI: ). Microfluidics can be used to introduce flow to facilitate nutrient supply to and waste removal from in vitro culture systems. Well-defined oxygen gradients can also be established. However, cells can quickly alter the oxygen balance in their vicinity. In this Tutorial Review, we expand on the Brennan paper to focus on the implementation of oxygen analysis in these systems to achieve continuous monitoring. Both electrochemical and optical approaches for the integration of oxygen monitoring in microfluidic tissue and cell culture systems will be discussed. Differences in oxygen requirements from one organ to the next are a challenging problem, as oxygen delivery is limited by its uptake into medium. Hence, we discuss the factors determining oxygen concentrations in solutions and consider the possible use of artificial oxygen carriers to increase dissolved oxygen concentrations. The selection of device material for applications requiring precise oxygen control is discussed in detail, focusing on oxygen permeability. Lastly, a variety of devices is presented, showing the diversity of approaches that can be employed to control and monitor oxygen concentrations in in vitro experiments.

  20. Reversible Oxygenation of 2,4-Diaminobutanoic Acid-Co(II) Complexes

    Science.gov (United States)

    Li, Hui; Yue, Fan; Wen, Hongmei

    2016-01-01

    This paper introduces the structural characterization and studies on reversible oxygenation behavior of a new oxygen carrier Co(II)-2,4-diaminobutanoic acid (DABA) complex in aqueous solution. The composition of the oxygenated complex was determined by gas volumetric method, molar ratio method, and mass spectrometry, and the formula of the oxygenated complex was determined to be [Co(DABA)2O2]. In aqueous solution, the complex can continuously uptake and release dioxygen and exhibit excellent reversibility of oxygenation and deoxygenation ability. This complex can maintain 50% of its original oxygenation capacity after 30 cycles in 24 h and retain 5% of the original oxygenation capacity after more than 260 cycles after 72 h. When a ligand analogue was linked to histidine (His), the new complex exhibited as excellent reversible oxygenation property as His-Co(II) complex. Insight into the relationship between structural detail and oxygenation properties will provide valuable suggestion for a new family of oxygen carriers.

  1. Carrier effects on tertiary nitrifying moving bed biofilm reactor: An examination of performance, biofilm and biologically produced solids.

    Science.gov (United States)

    Forrest, Daina; Delatolla, Robert; Kennedy, Kevin

    2016-01-01

    Increasingly stricter ammonia and nitrogen release regulations with respect to wastewater effluents are creating a need for tertiary treatment systems. The moving bed biofilm reactor (MBBR) is being considered as an upgrade option for an increasing number of wastewater treatment facilities due to its small footprint and ease of operation. Despite the MBBRs creation as a system to remove nitrogen, recent research on MBBR systems showing that the system's performance is directly related to carrier surface area and is irrespective of carrier shape and type has been performed exclusively on chemical oxygen demand (COD) removal systems. Furthermore, the influence of carrier type on the solids produced by MBBR systems has also been exclusively studied for COD removal systems. This work investigates the effects of three specific carrier types on ammonia removal rates, biofilm morphology, along with solids production and settleability of tertiary nitrifying MBBR systems. The study concludes that carrier type has no significant effect on tertiary nitrifying MBBR system performance under steady, moderate loading conditions. The research does however highlight the propensity of greater surface area to volume carriers to become clogged under high loading conditions and that the high surface area carriers investigated in this study required longer adjustment periods to changes in loading after becoming clogged.

  2. Oxygen therapy - infants

    Science.gov (United States)

    ... may not work well and may die. Your baby may not grow properly. Many of the developing organs, including the brain and heart, may be injured. Too much oxygen can also cause injury. Breathing too much oxygen can damage the lung. ...

  3. Proterozoic atmospheric oxygen

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene

    2014-01-01

    This article is concerned with the evolution of atmospheric oxygen concentrations through the Proterozoic Eon. In particular, this article will seek to place the history of atmospheric oxygenation through the Proterozoic Eon in the context of the evolving physical environment including the history...

  4. Extracorporeal membrane oxygenation circuitry.

    Science.gov (United States)

    Lequier, Laurance; Horton, Stephen B; McMullan, D Michael; Bartlett, Robert H

    2013-06-01

    The extracorporeal membrane oxygenation circuit is made of a number of components that have been customized to provide adequate tissue oxygen delivery in patients with severe cardiac and/or respiratory failure for a prolonged period of time (days to weeks). A standard extracorporeal membrane oxygenation circuit consists of a mechanical blood pump, gas-exchange device, and a heat exchanger all connected together with circuit tubing. Extracorporeal membrane oxygenation circuits can vary from simple to complex and may include a variety of blood flow and pressure monitors, continuous oxyhemoglobin saturation monitors, circuit access sites, and a bridge connecting the venous access and arterial infusion limbs of the circuit. Significant technical advancements have been made in the equipment available for short- and long-term extracorporeal membrane oxygenation applications. Contemporary extracorporeal membrane oxygenation circuits have greater biocompatibility and allow for more prolonged cardiopulmonary support time while minimizing the procedure-related complications of bleeding, thrombosis, and other physiologic derangements, which were so common with the early application of extracorporeal membrane oxygenation. Modern era extracorporeal membrane oxygenation circuitry and components are simpler, safer, more compact, and can be used across a wide variety of patient sizes from neonates to adults. PMID:23735989

  5. Highest Oxygen Bar

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The world’s highest altitude Lhalu Wetland in Tibet is rebounding from past environmental damage In Lhasa, where the oxygen content is just 60 percent of that of the plain area, a place known as the "natural oxygen bar"is highly prized by residents.

  6. Traveling with Portable Oxygen

    Science.gov (United States)

    ... that is right for you depends on your travel plans, your health requirements, and your personal preferences. Compressed Oxygen Compressed ... notice before your ight if you plan to travel with oxygen. For this ... to review procedures and complete all necessary paperwork required by ...

  7. Redox Homeostasis in Plants under Abiotic Stress: Role of electron carriers, energy metabolism mediators and proteinaceous thiols

    Directory of Open Access Journals (Sweden)

    Dhriti eKapoor

    2015-03-01

    Full Text Available Contemporaneous presence of both oxidized and reduced forms of electron carriers is mandatory in efficient flux by plant electron transport cascades. This requirement is considered as redox poising that involves the movement of electron from multiple sites in respiratory and photosynthetic electron transport chains to molecular oxygen. This flux triggers the formation of superoxide, consequently give rise to other reactive oxygen species (ROS under adverse environmental conditions like drought, high or low temperature, heavy metal stress etc. that plants owing during their life span. Plant cells synthesize ascorbate, an additional hydrophilic redox buffer, which protect the plants against oxidative challenge. Large pools of antioxidants also preside over the redox homeostasis. Besides, tocopherol is a liposoluble redox buffer, which efficiently scavenges the ROS like singlet oxygen. In addition, proteinaceous thiol members such as thioredoxin, peroxiredoxin and glutaredoxin, electron carriers and energy metabolism mediators phosphorylated (NADP and non-phosphorylated (NAD+ coenzyme forms interact with ROS, metabolize and maintain redox homeostasis.

  8. Oxygen potential studies on hypostoichiometric uranium-cerium mixed oxide

    Science.gov (United States)

    Nagarajan, K.; Saha, Rita; Yadav, R. B.; Rajagopalan, S.; Kutty, K. V. G.; Saibaba, M.; Rao, P. R. Vasudeva; Mathews, C. K.

    1985-02-01

    Oxygen potential measurements on (U,Ce)0 2-x with Ce/U + Ce ratios of 0.2 to 0.5 were carried out at 1073 and 1173 K by a gas equilibration method employing H 20/H 2 carrier gas. A new wet chemical method based on potentiometric titrations was used to determine and cross check the O/M ratios of the equilibrated samples. Lattice parameters of stoichiometric oxides were determined by x-ray diffraction. The oxygen potentials and their dependence on O/M and composition are discussed and compared with available literature data.

  9. Oxygen enrichment incineration

    International Nuclear Information System (INIS)

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested

  10. Oxygen enrichment incineration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested.

  11. Mitochondrial Reactive Oxygen Species Modulate Mosquito Susceptibility to Plasmodium Infection

    OpenAIRE

    Gonçalves, Renata L. S.; Oliveira, Jose Henrique M.; Oliveira, Giselle A.; Andersen, John F.; Oliveira, Marcus F.; Pedro L Oliveira; Barillas-Mury, Carolina

    2012-01-01

    Background Mitochondria perform multiple roles in cell biology, acting as the site of aerobic energy-transducing pathways and as an important source of reactive oxygen species (ROS) that modulate redox metabolism. Methodology/Principal Findings We demonstrate that a novel member of the mitochondrial transporter protein family, Anopheles gambiae mitochondrial carrier 1 (AgMC1), is required to maintain mitochondrial membrane potential in mosquito midgut cells and modulates epithelial responses ...

  12. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus.

    Science.gov (United States)

    Espinosa-Gongora, Carmen; Larsen, Niels; Schønning, Kristian; Fredholm, Merete; Guardabassi, Luca

    2016-01-01

    Staphylococcus aureus is presently regarded as an emerging zoonotic agent due to the spread of specific methicillin-resistant S. aureus (MRSA) clones in pig farms. Studying the microbiota can be useful for the identification of bacteria that antagonize such opportunistic veterinary and zoonotic pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium system. Carriers and non-carriers were selected on the basis of quantitative longitudinal data on S. aureus carriage in 600 pigs sampled at 20 Danish herds included in two previous studies in Denmark. Raw sequences were analysed with the BION meta package and the resulting abundance matrix was analysed using the DESeq2 package in R to identify operational taxonomic units (OTUs) with differential abundance between S. aureus carriers and non-carriers. Twenty OTUs were significantly associated to non-carriers, including species with known probiotic potential and antimicrobial effect such as lactic acid-producing isolates described among Leuconostoc spp. and some members of the Lachnospiraceae family, which is known for butyrate production. Further 5 OTUs were significantly associated to carriage, including known pathogenic bacteria such as Pasteurella multocida and Klebsiella spp. Our results show that the nasal microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate these bacteria and assess their possible antagonistic effect on S. aureus for the pursuit of new strategies to control MRSA in pig farming. PMID:27509169

  13. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus

    Science.gov (United States)

    Espinosa-Gongora, Carmen; Larsen, Niels; Schønning, Kristian; Fredholm, Merete; Guardabassi, Luca

    2016-01-01

    Staphylococcus aureus is presently regarded as an emerging zoonotic agent due to the spread of specific methicillin-resistant S. aureus (MRSA) clones in pig farms. Studying the microbiota can be useful for the identification of bacteria that antagonize such opportunistic veterinary and zoonotic pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium system. Carriers and non-carriers were selected on the basis of quantitative longitudinal data on S. aureus carriage in 600 pigs sampled at 20 Danish herds included in two previous studies in Denmark. Raw sequences were analysed with the BION meta package and the resulting abundance matrix was analysed using the DESeq2 package in R to identify operational taxonomic units (OTUs) with differential abundance between S. aureus carriers and non-carriers. Twenty OTUs were significantly associated to non-carriers, including species with known probiotic potential and antimicrobial effect such as lactic acid-producing isolates described among Leuconostoc spp. and some members of the Lachnospiraceae family, which is known for butyrate production. Further 5 OTUs were significantly associated to carriage, including known pathogenic bacteria such as Pasteurella multocida and Klebsiella spp. Our results show that the nasal microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate these bacteria and assess their possible antagonistic effect on S. aureus for the pursuit of new strategies to control MRSA in pig farming. PMID:27509169

  14. 惰性载体Al_2O_3对Fe_2O_3及CuO氧载体煤化学链燃烧的影响%Effect of Inert Support Al_2O_3 on the Chemical Looping Combustion of Coal With Fe_2O_3 and CuO-based Oxygen Carrier

    Institute of Scientific and Technical Information of China (English)

    王保文; 赵海波; 郑瑛; 柳朝晖; 郑楚光; 晏蓉

    2011-01-01

    氧载体是煤化学链燃烧技术的基础,惰性载体则是其中的必要组成部分,起着重要的作用。以Al2O3作为典型惰性载体,采用热重分析仪、红外频谱仪、场发射扫描电镜和能谱分析仪以及X衍射仪,对六盘水贫煤与Fe2O3、CuO基氧载体的反应进行了详细的研究。研究发现,Al2O3的引入,使得Fe2O3、CuO基氧载体表面积增大、孔径分布更为优化,而且对氧载体与六盘水贫煤一次热解产物的反应是有利的,能够促进氧载体中更多晶格氧的传递,Fe2O3基氧载体中有更多的Fe2O3还原为低于Fe3O4价态的氧化物,而CuO基氧载体中CuO除了还原为Cu、Cu2O外,其中的CuAl2O4也有一定的反应活性,被还原为CuAlO2。与LPS煤反应时,Fe2O3深度还原产物与部分Al2O3及煤中的SiO2反应生成Fe3Al2(SiO4)3,而CuO则与Al2O3及六盘水贫煤反应生成了(Cu0.215Mg1.785)(Al4Si5O18)复合物。%Oxygen carrier(OC) is the basis for chemical looping combustion of coal and inert support is the necessary part of OC.Al2O3 was adopted as the typical inert support and the reaction of Liupanshui(LPS) coal with Fe2O3,CuO based OC was systematically investigated by various experimental means,including thermogravimetric analysis(TGA),Fourier transform infrared spectroscopy(FTIR),field scanning electron microscopy coupled with energy-dispersive X-ray spectrometry(FSEM-EDX) and X-ray diffraction(XRD) analysis.It was found that,the introduction of Al2O3 to Fe2O3 and CuO made the surface areas of these two OC greatly increased and the pore distribution more optimized,which benefited the primary gaseous products of LPS coal to react with Fe2O3 and CuO.Furthermore,during the reaction of LPS with these two OC,the optimized pore size distribution promoted more sufficient reaction of LPS coal with Fe2O3,and thus more Fe2O3 was reduced into lower valence oxides than Fe3O4;but for CuO based OC,their solid reduced products with

  15. 49 CFR 1139.22 - Revenue data for study carriers.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Revenue data for study carriers. 1139.22 Section... BOARD, DEPARTMENT OF TRANSPORTATION RULES OF PRACTICE PROCEDURES IN MOTOR CARRIER REVENUE PROCEEDINGS Intercity Bus Industry § 1139.22 Revenue data for study carriers. The study carriers, as identified...

  16. Comparison of the MBBR denitrification carriers for advanced nitrogen removal of wastewater treatment plant effluent.

    Science.gov (United States)

    Yuan, Quan; Wang, Haiyan; Hang, Qianyu; Deng, Yangfan; Liu, Kai; Li, Chunmei; Zheng, Shengzhi

    2015-09-01

    The moving bed biofilm reactors (MBBRs) were used to remove the residual NO3(-)-N of wastewater treatment plant (WWTP) effluent, and the MBBR carriers for denitrification were compared. The results showed that high denitrification efficiency can be achieved with polyethylene, polypropylene, polyurethane foam, and haydite carriers under following conditions: 7.2 to 8.0 pH, 24 to 26 °C temperature, 12 h hydraulic retention time (HRT), and 25.5 mg L(-1) external methanol dosage, while the WWTP effluent total nitrogen (TN) was between 2.6 and 15.4 mg L(-1) and NO3(-)-N was between 0.2 and 12.6 mg L(-1). The MBBR filled with polyethylene carriers had higher TN and NO3(-)-N removal rate (44.9 ± 19.1 and 83.4 ± 13.0%, respectively) than those with other carriers. The minimum effluent TN and NO3(-)-N of polyethylene MBBR were 1.6 and 0.1 mg L(-1), respectively, and the maximum denitrification rate reached 23.0 g m(-2) day(-1). When chemical oxygen demand (COD)/TN ratio dropped from 6 to 4, the NO3(-)- N and TN removal efficiency decreased significantly in all reactors except for that filled with polyethylene, which indicated that the polyethylene MBBR can resist influent fluctuation much better. The three-dimensional excitation-emission matrix analysis showed that all the influent and effluent of MBBRs contain soluble microbial products (SMPs)-like organics and biochemical oxygen demand (BOD), which can be removed better by MBBRs filled with haydite and polyethylene carriers. The nitrous oxide reductase (nosZ)-based terminal restriction fragment length polymorphism (T-RFLP) analysis suggested that the dominant bacteria in polyethylene MBBR are the key denitrificans.

  17. Charge carrier transport in liquid crystals

    International Nuclear Information System (INIS)

    The materials exhibiting charge carrier mobility ranging from 10−3 to 0.1 cm2/Vs, i.e., between those of amorphous and crystalline materials, had been missing before the 1990s when the electronic conduction in liquid crystals was discovered. Since then, various liquid crystalline materials including discotic and calamitic liquid crystals have been studied in order to clarify their charge carrier transport properties in liquid crystalline mesophases. In this article, the historical background of the discovery of electronic conduction in liquid crystals, intrinsic and extrinsic conductions, unique properties of the charge carrier transport, the effect of molecular alignment on it, and the conduction mechanism in liquid crystalline mesophases are shortly described on the basis of the experimental and theoretical studies accumulated in these two decades, noting that the missing materials were liquid crystals. - Highlights: • Liquid crystals exhibit charge mobility ranging from 10–3 to 0.1 cm2/Vs. • Electronic (intrinsic) and ionic (extrinsic) conductions in liquid crystals • Unique charge carrier transport properties in liquid crystals • Effect of molecular alignment in mesophases on charge carrier transport • Conduction mechanism in smectic liquid crystals

  18. Extracting hot carriers from photoexcited semiconductor nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaoyang

    2014-12-10

    This research program addresses a fundamental question related to the use of nanomaterials in solar energy -- namely, whether semiconductor nanocrystals (NCs) can help surpass the efficiency limits, the so-called “Shockley-Queisser” limit, in conventional solar cells. In these cells, absorption of photons with energies above the semiconductor bandgap generates “hot” charge carriers that quickly “cool” to the band edges before they can be utilized to do work; this sets the solar cell efficiency at a limit of ~31%. If instead, all of the energy of the hot carriers could be captured, solar-to-electric power conversion efficiencies could be increased, theoretically, to as high as 66%. A potential route to capture this energy is to utilize semiconductor nanocrystals. In these materials, the quasi-continuous conduction and valence bands of the bulk semiconductor become discretized due to confinement of the charge carriers. Consequently, the energy spacing between the electronic levels can be much larger than the highest phonon frequency of the lattice, creating a “phonon bottleneck” wherein hot-carrier relaxation is possible via slower multiphonon emission. For example, hot-electron lifetimes as long as ~1 ns have been observed in NCs grown by molecular beam epitaxy. In colloidal NCs, long lifetimes have been demonstrated through careful design of the nanocrystal interfaces. Due to their ability to slow electronic relaxation, semiconductor NCs can in principle enable extraction of hot carriers before they cool to the band edges, leading to more efficient solar cells.

  19. Dedicated Carrier Deployment in Heterogeneous Networks with Inter-site Carrier Aggregation

    DEFF Research Database (Denmark)

    Wang, Hua; Rosa, Claudio; Pedersen, Klaus I.

    2013-01-01

    ) or picos with dedicated carrier deployment. Collaborative inter-site carrier aggregation (CA) is proposed in scenarios with macro+RRH deployment to make an efficient use of the fragmented spectrum from multiple cells. While in scenarios with macro+pico deployment, UEs can only connect to either...

  20. Glutathione in Cellular Redox Homeostasis: Association with the Excitatory Amino Acid Carrier 1 (EAAC1

    Directory of Open Access Journals (Sweden)

    Koji Aoyama

    2015-05-01

    Full Text Available Reactive oxygen species (ROS are by-products of the cellular metabolism of oxygen consumption, produced mainly in the mitochondria. ROS are known to be highly reactive ions or free radicals containing oxygen that impair redox homeostasis and cellular functions, leading to cell death. Under physiological conditions, a variety of antioxidant systems scavenge ROS to maintain the intracellular redox homeostasis and normal cellular functions. This review focuses on the antioxidant system’s roles in maintaining redox homeostasis. Especially, glutathione (GSH is the most important thiol-containing molecule, as it functions as a redox buffer, antioxidant, and enzyme cofactor against oxidative stress. In the brain, dysfunction of GSH synthesis leading to GSH depletion exacerbates oxidative stress, which is linked to a pathogenesis of aging-related neurodegenerative diseases. Excitatory amino acid carrier 1 (EAAC1 plays a pivotal role in neuronal GSH synthesis. The regulatory mechanism of EAAC1 is also discussed.

  1. Hiding secret data into a carrier image

    Directory of Open Access Journals (Sweden)

    Ovidiu COSMA

    2012-06-01

    Full Text Available The object of steganography is embedding hidden information in an appropriate multimedia carrier, e.g., image, audio, or video. There are several known methods of solving this problem, which operate either in the space domain or in the frequency domain, and are distinguished by the following characteristics: payload, robustness and strength. The payload is the amount of secret data that can be embedded in the carrier without inducing suspicious artefacts, robustness indicates the degree in which the secret data is affected by the normal processing of the carrier e.g., compression, and the strength indicate how easy the presence of hidden data can be detected by steganalysis techniques. This paper presents a new method of hiding secret data into a digital image compressed by a technique based on the Discrete Wavelet Transform (DWT [2] and the Set Partitioning In Hierarchical Trees (SPIHT subband coding algorithm [6]. The proposed method admits huge payloads and has considerable strength.

  2. Hot Carrier extraction with plasmonic broadband absorbers

    CERN Document Server

    Ng, Charlene; Dligatch, Svetlana; Roberts, Ann; Davis, Timothy J; Mulvaney, Paul; Gomez, Daniel E

    2016-01-01

    Hot charge carrier extraction from metallic nanostructures is a very promising approach for applications in photo-catalysis, photovoltaics and photodetection. One limitation is that many metallic nanostructures support a single plasmon resonance thus restricting the light-to-charge-carrier activity to a spectral band. Here we demonstrate that a monolayer of plasmonic nanoparticles can be assembled on a multi-stack layered configuration to achieve broad-band, near-unit light absorption, which is spatially localised on the nanoparticle layer. We show that this enhanced light absorbance leads to $\\sim$ 40-fold increases in the photon-to-electron conversion efficiency by the plasmonic nanostructures. We developed a model that successfully captures the essential physics of the plasmonic hot-electron charge generation and separation in these structures. This model also allowed us to establish that efficient hot carrier extraction is limited to spectral regions where the photons possessing energies higher than the S...

  3. Carrier lifetimes in thin-film photovoltaics

    Science.gov (United States)

    Baek, Dohyun

    2015-09-01

    The carrier lifetimes in thin-film solar cells are reviewed and discussed. Shockley-Read-Hall recombination is dominant at low carrier density, Auger recombination is dominant under a high injection condition and high carrier density, and surface recombination is dominant under any conditions. Because the surface photovoltage technique is insensitive to the surface condition, it is useful for bulk lifetime measurements. The photoconductance decay technique measures the effective recombination lifetime. The time-resolved photoluminescence technique is very useful for measuring thin-film semiconductor or solar-cell materials lifetime, because the sample is thin, other techniques are not suitable for measuring the lifetime. Many papers have provided time-resolved photoluminescence (TRPL) lifetimes for copper-indium-gallium-selenide (CIGS) and CdTe thin-film solar cell. The TRPL lifetime strongly depends on open-circuit voltage and conversion efficiency; however, the TRPL life time is insensitive to the short-circuit current.

  4. Development of radioisotope labeled polymeric carriers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Jin; Jeong, Jea Min; Hwang, Hyun Jeong [Ewha Womans University, Seoul (Korea)

    2000-04-01

    This research was performed with the aim of developing polymeric radioisotope or drug carriers for obtaining efficient diagnostic therapeutic efficacy. As polymers, polyethylene oxides, polylactides, polycaprolactone were chosen to prepare the devices including micelle system, microemulsion, nanospheres. In addition, anticancer drug loaded polylactide microparticulates were fabricated as a regional chemotherapeutics for the treatment of cancer. Technetium or radioactive iodine was labeled to the polymeric carriers via ligands such as DTPA and HPP, respectively. Labeling efficiency was above 90% and stable enough up to 24 hours. Moreover, injected polymer carriers demonstrated higher blood maintenance and bone uptake than Tin colloid, a control. These results suggested that radioisotope carrying polymeric particulate are promising tools for diagnosing blood vessels or bones. Besides, anticancer drug loaded particulates demonstrated appropriate maintenance of therapeutic concentration and localization. Therefore it was proposed that this therapeutic system may be potential as a cancer therapy modality. 20 refs., 24 figs.,5 tabs. (Author)

  5. High Selectivity Oxygen Delignification

    Energy Technology Data Exchange (ETDEWEB)

    Lucian A. Lucia

    2005-11-15

    Project Objective: The objectives of this project are as follows: (1) Examine the physical and chemical characteristics of a partner mill pre- and post-oxygen delignified pulp and compare them to lab generated oxygen delignified pulps; (2) Apply the chemical selectivity enhancement system to the partner pre-oxygen delignified pulps under mill conditions (with and without any predetermined amounts of carryover) to determine how efficiently viscosity is preserved, how well selectivity is enhanced, if strength is improved, measure any yield differences and/or bleachability differences; and (3) Initiate a mill scale oxygen delignification run using the selectivity enhancement agent, collect the mill data, analyze it, and propose any future plans for implementation.

  6. Optic nerve oxygenation

    DEFF Research Database (Denmark)

    Stefánsson, Einar; Pedersen, Daniella Bach; Jensen, Peter Koch;

    2005-01-01

    at similar levels of perfusion pressure. The levels of perfusion pressure that lead to optic nerve hypoxia in the laboratory correspond remarkably well to the levels that increase the risk of glaucomatous optic nerve atrophy in human glaucoma patients. The risk for progressive optic nerve atrophy in human......The oxygen tension of the optic nerve is regulated by the intraocular pressure and systemic blood pressure, the resistance in the blood vessels and oxygen consumption of the tissue. The oxygen tension is autoregulated and moderate changes in intraocular pressure or blood pressure do not affect...... glaucoma patients is six times higher at a perfusion pressure of 30 mmHg, which corresponds to a level where the optic nerve is hypoxic in experimental animals, as compared to perfusion pressure levels above 50 mmHg where the optic nerve is normoxic. Medical intervention can affect optic nerve oxygen...

  7. Hot-carrier effects in MOS devices

    CERN Document Server

    Takeda, Eiji; Miura-Hamada, Akemi

    1995-01-01

    The exploding number of uses for ultrafast, ultrasmall integrated circuits has increased the importance of hot-carrier effects in manufacturing as well as for other technological applications. They are rapidly movingout of the research lab and into the real world.This book is derived from Dr. Takedas book in Japanese, Hot-Carrier Effects, (published in 1987 by Nikkei Business Publishers). However, the new book is much more than a translation. Takedas original work was a starting point for developing this much more complete and fundamental text on this increasingly important topic. The new work

  8. Line broadening caused by Coulomb carrier-carrier correlations and dynamics of carrier capture and emission in quantum dots

    DEFF Research Database (Denmark)

    Uskov, Alexander V; Magnúsdóttir, Ingibjörg; Tromborg, Bjarne;

    2001-01-01

    Mechanisms of pure dephasing in quantum dots due to Coulomb correlations and the dynamics of carrier capture and emission are suggested, and a phenomenological model for the dephasing is developed. It is shown that, if the rates of these capture and emission processes are sufficiently high, signi......, significant homogeneous line broadening of the order of several meV can result....

  9. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    la Cour, M; Kiilgaard, Jens Folke; Eysteinsson, T;

    2000-01-01

    To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide.......To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide....

  10. Practical procedures: oxygen therapy.

    Science.gov (United States)

    Olive, Sandra

    Knowing when to start patients on oxygen therapy can save lives, but ongoing assessment and evaluation must be carried out to ensure the treatment is safe and effective. This article outlines when oxygen therapy should be used and the procedures to follow. It also describes the delivery methods applicable to different patient groups, along with the appropriate target saturation ranges, and details relevant nurse competencies.

  11. Interplay between carrier and cationic defect concentration in ferromagnetism of anatase Ti1-xTaxO2 thin films

    Directory of Open Access Journals (Sweden)

    A. Roy Barman

    2012-03-01

    Full Text Available Thin films of Ta incorporated TiO2 grown by pulsed laser deposition under specific growth conditions show room temperature ferromagnetism. Ta introduces carriers and concomitantly cationic defects, the combination of which leads to ferromagnetism. In this paper, we report on the dependence of the carrier and cationic defect density (compensation on various parameters such as oxygen growth pressure, temperature and Ta concentration. Most likely, the Ti vacancies act as magnetic centers and the free electrons help with the exchange leading to ferromagnetism via Ruderman-Kittel-Kasuya-Yosida mechanism.

  12. OXYGEN DEPLETION IN THE INTERSTELLAR MEDIUM: IMPLICATIONS FOR GRAIN MODELS AND THE DISTRIBUTION OF ELEMENTAL OXYGEN

    International Nuclear Information System (INIS)

    This paper assesses the implications of a recent discovery that atomic oxygen is being depleted from diffuse interstellar gas at a rate that cannot be accounted for by its presence in silicate and metallic oxide particles. To place this discovery in context, the uptake of elemental O into dust is considered over a wide range of environments, from the tenuous intercloud gas and diffuse clouds sampled by the depletion observations to dense clouds where ice mantles and gaseous CO become important reservoirs of O. The distribution of O in these contrasting regions is quantified in terms of a common parameter, the mean number density of hydrogen (nH). At the interface between diffuse and dense phases (just before the onset of ice-mantle growth) as much as ∼160 ppm of the O abundance is unaccounted for. If this reservoir of depleted oxygen persists to higher densities it has implications for the oxygen budget in molecular clouds, where a shortfall of the same order is observed. Of various potential carriers, the most plausible appears to be a form of O-bearing carbonaceous matter similar to the organics found in cometary particles returned by the Stardust mission. The 'organic refractory' model for interstellar dust is re-examined in the light of these findings, and it is concluded that further observations and laboratory work are needed to determine whether this class of material is present in quantities sufficient to account for a significant fraction of the unidentified depleted oxygen.

  13. Adsorption interaction of carrier-free thallium species with gold and quartz surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Serov, A.; Eichler, R.; Tuerler, A.; Wittwer, D.; Gaeggeler, H.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland). Lab. fuer Radio- und Umweltchemie; Bern Univ. (Switzerland). Dept. for Chemistry and Biochemistry; Dressler, R.; Piquet, D.; Voegele, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland). Lab. fuer Radio- und Umweltchemie

    2013-08-01

    The adsorption interactions of thallium and its compounds with gold and quartz surfaces were investigated. Carrier-free amounts of thallium were produced in nuclear fusion reactions of alpha particles with thick gold targets. The method chosen for the studies was gas thermochromatography and varying the redox potential of the carrier gases. It was observed that thallium is extremely sensitive to trace amounts of oxygen and water, and can even be oxidized by the hydroxyl groups located on the quartz surface. The experiments on a quartz surface with O{sub 2}, He, H{sub 2} gas in addition with water revealed the formation and deposition of only one thallium species - TlOH. The adsorption enthalpy was determined to be {Delta} H{sub ads}{sup SiO{sub 2}} (TlOH) = -134 {+-} 5 kJ mol{sup -1}. A series of experiments using gold as stationary surface and different carrier gases resulted in the detection of two thallium species - metallic Tl (H{sub 2} as carrier gas) and TlOH (O{sub 2}, O{sub 2} + H{sub 2}O and H{sub 2} + H{sub 2}O as pure carrier gas or carrier gas mixture) with {Delta} H{sup Au}{sub ads} (Tl) = -270 {+-} 10 kJ mol{sup -1} and {Delta} H{sup Au}{sub ads} (TlOH) = -146 {+-} 3 kJ mol{sup -1}. These data demonstrate a weak interaction of TlOH with both quartz and gold surfaces. The data represent important information for the design of future experiments with the heavier homologue of Tl in group 13 of the periodic table - element 113 (E113). (orig.)

  14. Advanced two-way satellite frequency transfer by carrier-phase and carrier-frequency measurements

    Science.gov (United States)

    Fujieda, Miho; Gotoh, Tadahiro; Amagai, Jun

    2016-06-01

    Carrier-phase measurement is one of the ways to improve the measurement resolution of two-way satellite frequency transfer. We introduce two possible methods for carrier-phase measurement: direct carrier-phase detection identified by Two-Way Carrier-Phase (TWCP) and the use of carrier-frequency information identified by Two-Way Carrier Frequency (TWCF). We performed the former using an arbitrary waveform generator and an analog-to-digital sampler and the latter using a conventional modem. The TWCF measurement using the modem had a resolution of 10-13 and the result agreed with that obtained by GPS carrier-phase frequency transfer in a 1500 km baseline. The measurement accuracy may have been limited by the poor frequency resolution of the modem; however, the TWCF measurement was able to improve the stability of conventional two-way satellite frequency transfer. Additionally, we show that the TWCP measurement system has the potential to achieve a frequency stability of 10-17.

  15. Zaria Universal Oxygenator Holder phase I

    Directory of Open Access Journals (Sweden)

    Sunday Adoga Edaigbini

    2014-01-01

    Full Text Available Introduction: The conduct of cardiopulmonary bypass surgery requires the use of equipment and devices like the oxygenator. The oxygenator comes in different makes and each manufacturer customizes the carrier or ′holder′ of this device specific to their design. Aim: This paper presents an innovation designed to overcome the need to purchase a different holder for every oxygenator thereby cutting the cost. Materials and Methods: A sheet of iron measuring 1.9 cm (width × 0.1 cm (thickness was used to design the holder circular main frame. Another sheet measuring 2 cm (width × 0.6 cm (thickness × 24 cm (length was used to construct a V-shaped handle with the arms of the V attached to the main frame 7 cm apart. At the narrow base of the handle is a latch requiring two 13-gauge screws to attach the holder to the heart-lung machine. Within the circumference of the main frame are four T-shaped side arms which grip the oxygenator; located at 2, 5, 7 and 11 O′clock positions. The stem of the T consist of a 0.6 cm (thickness × 13 cm (length rod drilled through the main frame. The cross of the T consists of variable lengths of the same sheet as the mainframe attached to the stem by a screw mechanism. At the base of the T, is attached a circular handle (4 cm in diameter made of 0.4 cm iron rod. Result: An oxygenator holder which weighs 1.75 kg with a total length of 54 cm (the diameter of the mainframe is 30 cm. Its advantages include (i affordability, (ii materials are locally accessible, (iii versatility (iv reproducibility. The disadvantages include, (i it requires some time to fit, (ii caution is required in fitting the oxygenator to avoid breakage, (iii a spanner is required to lock the latch. Conclusion: The concept of a universal holder is pertinent, especially in resource poor environments to avoid purchasing a new holder whenever the usual oxygenator common to the centre is unavailable. This device is amenable to further modifications to

  16. Polyester Dendrimers: Smart Carriers for Drug Delivery

    Directory of Open Access Journals (Sweden)

    Jean–d’Amour K. Twibanire

    2014-01-01

    Full Text Available Polyester dendrimers have been shown to be outstanding candidates for biomedical applications. Compared to traditional polymeric drug vehicles, these biodegradable dendrimers show excellent advantages especially as drug delivery systems because they are non-toxic. Here, advances on polyester dendrimers as smart carriers for drug delivery applications have been surveyed. Both covalent and non-covalent incorporation of drugs are discussed.

  17. Towards 100 gigabit carrier ethernet transport networks

    DEFF Research Database (Denmark)

    Rasmussen, Anders; Zhang, Jiang; Yu, Hao;

    2010-01-01

    Ethernet as a transport technology has, up to now, lacked the features such as network layer architecture, customer separation and manageability that carriers require for wide-scale deployment. However, with the advent of PBB-TE and TMPLS, it is now possible to use Ethernet as a transport...

  18. A new lubricant carrier for metal forming

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Bay, Niels; Tang, Peter Torben;

    2009-01-01

    A lubricant carrier for metal forming processes is developed. Surfaces with pores of micrometer size for entrapping lubricant are generated by electrochemical deposition of an alloy, consisting of two immiscible metals, of which one metal subsequently is etched away leaving 5 mu m layers with a s...... extrusion at high reduction and excessive stroke comparing with conventionally lubrication using phosphate coating and soap....

  19. Polyester Dendrimers: Smart Carriers for Drug Delivery

    OpenAIRE

    Jean–d’Amour K. Twibanire; T. Bruce Grindley

    2014-01-01

    Polyester dendrimers have been shown to be outstanding candidates for biomedical applications. Compared to traditional polymeric drug vehicles, these biodegradable dendrimers show excellent advantages especially as drug delivery systems because they are non-toxic. Here, advances on polyester dendrimers as smart carriers for drug delivery applications have been surveyed. Both covalent and non-covalent incorporation of drugs are discussed.

  20. Dextran: A promising macromolecular drug carrier

    Directory of Open Access Journals (Sweden)

    Dhaneshwar Suneela

    2006-01-01

    Full Text Available Over the past three decades intensive efforts have been made to design novel systems able to deliver the drug more effectively to the target site. The ongoing intense search for novel and innovative drug delivery systems is predominantly a consequence of the well-established fact that the conventional dosage forms are not sufficiently effective in conveying the drug compound to its site of action and once in the target area, in releasing the active agent over a desired period of time. The potential use of macromolecular prodrugs as a means of achieving targeted drug delivery has attracted considerable interest in recent years. Macromolecules such as antibodies, lipoproteins, lectins, proteins, polypeptides, polysaccharides, natural as well as synthetic polymers offer potential applicabilities as high molecular weight carriers for various therapeutically active compounds. Dextrans serve as one of the most promising macromolecular carrier candidates for a wide variety of therapeutic agents due to their excellent physico-chemical properties and physiological acceptance. The present contribution attempts to review various features of the dextran carrier like its source, structural and physico-chemical characteristics, pharmacokinetic fate and its applications as macromolecular carrier with special emphasis on dextran prodrugs.

  1. Itaconic acid carrier ampholytes for isoelectric focusing.

    Science.gov (United States)

    Brenna, O

    1977-04-11

    Commercial carrier ampholytes, obtained by coupling polyethylene polyamines to acrylic acid, exhibit a conductivity minimum in the pH range 5.5-6.5 owing to the lack of appropriate pK values of the polyamine in this pH region. By replacing acrylic with itaconic acid, it has been possible to effect substantial improvements in the pH range 5.5-6.5 as itaconic acid has a pK2 value of 5.45. Upon coupling, the pK of the gramma-carboxyl group remains virtually unaltered. With itoconic acid carrier ampholytes it has been possible to improve the conductivity in the pH range 5.5-6.5 by as much as 400% compared with conventional carrier ampholytes. It is suggected that the commercial products should be supplemented with itaconic acid carrier ampholytes in order to obtain a more uniform conductivity and buffering capacity in the pH range 3-10.

  2. 7 CFR 35.4 - Carrier.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Carrier. 35.4 Section 35.4 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS EXPORT...

  3. Mass, energy, and exergy balance analysis of chemical looping with oxygen uncoupling (CLOU) process

    International Nuclear Information System (INIS)

    Highlights: • A CLOU reactor system using a CuO-based OC and coal as fuel is analyzed. • Possible operational regions for the chosen OC are identified. • Different heat balance scenarios are investigated. • The second-law efficiency of the system is evaluated. • Various design aspects and process modelling relationships are discussed. - Abstract: Chemical looping with oxygen uncoupling (CLOU) is a promising concept for efficient combustion of solid fuels with an inherent capture of the greenhouse gas CO2. This paper presents a CLOU process scheme with stoichiometric mass, energy, and exergy balances. A CLOU reactor system using medium volatile bituminous coal as fuel and silica-supported CuO as an oxygen carrier is analyzed. The analysis includes the estimation of various design and operational parameters, thermal considerations, and evaluation of the overall performance. The operation of a reactor system of two interacting circulating fluidized beds (CFBs) is greatly influenced by the hydrodynamics. For the CuO oxygen carrier, the hydrodynamic operating range appeared feasible considering the maximum solid circulation rates in current CFB boilers. Depending upon the reactor temperatures, oxygen carrier inventories of 400–680 kg/MW in the system were found necessary for stoichiometric combustion of the fuel. The temperature difference between the reactors should not exceed 50 °C, as otherwise, problems may arise with the heat balance. Exergetic efficiencies in the range of 63–70% were obtained for different combinations of relevant design parameters. It is evident that the possible operating conditions in the system are closely related to the properties of the chosen oxygen carrier. However, the calculation procedure and design criteria presented here are applicable to any oxygen carrier to be used in the process

  4. Simulation of oxygen saturation of hemoglobin solution, RBC suspension and hemosome by a neural network system.

    Science.gov (United States)

    Kan, P; Chen, W K; Lee, C J

    1996-03-01

    Hemoglobin-based artificial blood substitutes as oxygen carrier is advantageous over current plasma expander. In this study, oxygen saturation of hemoglobin solution, red blood cell suspension and artificial blood substitute under various conditions were measured by yeast-consuming-oxygen experiments instead of spectrophotometer. The empirical results were assigned into training feedforward back-propagation neural network system in order to simulate the oxygen saturation model modulated by those factors such as pH, [Cl-], [2,3-DPG], pO2 and pCO2. Consequently, this neural network is able to simulate accurately the oxygen saturation of Hb solution. The prediction of hemosome is not agreed well possible because of the resistance of transport of oxygen. However, the results showed neural net can offer a simple and convenient way in comparison with the conventional methods, especially in dealing with complex and ambiguous problem.

  5. Kinetics and mechanism of hexavalent chromium removal by basic oxygen furnace slag.

    Science.gov (United States)

    Han, Chong; Jiao, Yanan; Wu, Qianqian; Yang, Wangjin; Yang, He; Xue, Xiangxin

    2016-08-01

    Basic oxygen furnace slag (BOFS) has the potential to remove hexavalent chromium (Cr(VI)) from wastewater by a redox process due to the presence of minerals containing Fe(2+). The effects of the solution pH, initial Cr(VI) concentration, BOFS dosage, BOFS particle size, and temperature on the removal of Cr(VI) was investigated in detail through batch tests. The chemical and mineral compositions of fresh and reacted BOFS were characterized using scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS) system and X-ray diffractometer (XRD). The results show that Cr(VI) in wastewater can be efficiently removed by Fe(2+) released from BOFS under appropriate acidic conditions. The removal of Cr(VI) by BOFS significantly depended on the parameters mentioned above. The reaction of Cr(VI) with BOFS followed the pseudo-second-order kinetic model. Fe(2+) responsible for Cr(VI) removal was primarily derived from the dissolution of FeO and Fe3O4 in BOFS. When H2SO4 was used to adjust the solution acidity, gypsum (CaSO4·2H2O) could be formed and become an armoring precipitate layer on the BOFS surface, hindering the release of Fe(2+) and the removal of Cr(VI). Finally, the main mechanism of Cr(VI) removal by BOFS was described using several consecutive reaction steps. PMID:27521937

  6. Lower frequency of Gaucher disease carriers among Tay-Sachs disease carriers.

    Science.gov (United States)

    Peleg, L; Frisch, A; Goldman, B; Karpaty, M; Narinsky, R; Bronstein, S; Frydman, M

    1998-01-01

    The heterozygote frequency of Gaucher disease (GD) and Tay-Sachs disease (TSD) is distinctly high among Ashkenazi Jews (1:29 for TSD and 1:16 for GD). Two main theories have been suggested to explain this high occurrence: a founder effect with subsequent genetic drift, and a selective advantage of heterozygotes. We compared the frequency of the GD most common mutation (1226A-->G) among carriers of the common TSD mutation (+1277 TATC) with the frequency of this mutation in the general Ashkenazi population. The frequency of GD carriers among 308 TSD heterozygotes was 1:28 which is about half the expected (P = 0.03). These results indicate that carriers of both diseases do not possess additional evolutionary advantage over single mutation carriers. A reasonable interpretation of these findings is that one or both mutations have arisen relatively recently in different regions of Europe and have not yet reached genetic equilibrium. PMID:9781065

  7. PAPR Reduction in OFDM Systems with Large Number of Sub-Carriers by Carrier Interferometry Approaches

    Institute of Scientific and Technical Information of China (English)

    HE Jian-hui; QUAN Zi-yi; MEN Ai-dong

    2004-01-01

    High Peak-to-Average Power Ratio (PAPR) is one of the major drawbacks of Orthogonal Frequency Division Multiplexing ( OFDM) systems. This paper presents the structures of the particular bit sequences leading to the maximum PAPR (PAPRmax) in Carrier-Interferometry OFDM (CI/OFDM) and Pseudo Orthogonal Carrier-Interferometry OFDM (PO-CI/OFDM) systems for Binary Phase Shift Keying (BPSK) modulation. Furthermore, the simulation and analysis of PAPRmax and PAPR cumulative distribution in CI/OFDM and PO-CI/OFDM systems with 2048 sub-carriers are presented in this paper. The results show that the PAPR of OFDM system with large number of sub-carriers reduced evidently via CI approaches.

  8. Feasibility study of sulfates as oxygen carriers for chemical looping processes

    Directory of Open Access Journals (Sweden)

    Ganesh Kale

    2012-12-01

    Full Text Available The operational feasibility temperature range of chemical looping combustion (CLC and chemical looping reforming (CLR of the fuels methane, propane, iso-octane and ethanol was explored using the common sulphates

  9. Molecular Evolution of the Oxygen-Binding Hemerythrin Domain.

    Directory of Open Access Journals (Sweden)

    Claudia Alvarez-Carreño

    Full Text Available The evolution of oxygenic photosynthesis during Precambrian times entailed the diversification of strategies minimizing reactive oxygen species-associated damage. Four families of oxygen-carrier proteins (hemoglobin, hemerythrin and the two non-homologous families of arthropodan and molluscan hemocyanins are known to have evolved independently the capacity to bind oxygen reversibly, providing cells with strategies to cope with the evolutionary pressure of oxygen accumulation. Oxygen-binding hemerythrin was first studied in marine invertebrates but further research has made it clear that it is present in the three domains of life, strongly suggesting that its origin predated the emergence of eukaryotes.Oxygen-binding hemerythrins are a monophyletic sub-group of the hemerythrin/HHE (histidine, histidine, glutamic acid cation-binding domain. Oxygen-binding hemerythrin homologs were unambiguously identified in 367/2236 bacterial, 21/150 archaeal and 4/135 eukaryotic genomes. Overall, oxygen-binding hemerythrin homologues were found in the same proportion as single-domain and as long protein sequences. The associated functions of protein domains in long hemerythrin sequences can be classified in three major groups: signal transduction, phosphorelay response regulation, and protein binding. This suggests that in many organisms the reversible oxygen-binding capacity was incorporated in signaling pathways. A maximum-likelihood tree of oxygen-binding hemerythrin homologues revealed a complex evolutionary history in which lateral gene transfer, duplications and gene losses appear to have played an important role.Hemerythrin is an ancient protein domain with a complex evolutionary history. The distinctive iron-binding coordination site of oxygen-binding hemerythrins evolved first in prokaryotes, very likely prior to the divergence of Firmicutes and Proteobacteria, and spread into many bacterial, archaeal and eukaryotic species. The later evolution of the

  10. Field Effect and Strongly Localized Carriers in the Metal-Insulator Transition Material VO(2).

    Science.gov (United States)

    Martens, K; Jeong, J W; Aetukuri, N; Rettner, C; Shukla, N; Freeman, E; Esfahani, D N; Peeters, F M; Topuria, T; Rice, P M; Volodin, A; Douhard, B; Vandervorst, W; Samant, M G; Datta, S; Parkin, S S P

    2015-11-01

    The intrinsic field effect, the change in surface conductance with an applied transverse electric field, of prototypal strongly correlated VO(2) has remained elusive. Here we report its measurement enabled by epitaxial VO(2) and atomic layer deposited high-κ dielectrics. Oxygen migration, joule heating, and the linked field-induced phase transition are precluded. The field effect can be understood in terms of field-induced carriers with densities up to ∼5×10(13)  cm(-2) which are trongly localized, as shown by their low, thermally activated mobility (∼1×10(-3)  cm(2)/V s at 300 K). These carriers show behavior consistent with that of Holstein polarons and strongly impact the (opto)electronics of VO(2). PMID:26588400

  11. Effect of ferroelectric substrate on carrier mobility in graphene field-effect transistors

    Science.gov (United States)

    Bidmeshkipour, S.; Vorobiev, A.; Andersson, M. A.; Kompany, A.; Stake, J.

    2015-10-01

    Effect of LiNbO3 ferroelectric substrate on the carrier mobility in top gated graphene field-effect transistors (G-FETs) is demonstrated. It is shown that, at the same residual concentration of the charge carriers, the mobility in the G-FETs on the LiNbO3 substrate is higher than that on the SiO2/Si substrate. The effect is associated with reduction of Coulomb scattering via screening the charged impurity field by the field induced in the ferroelectric substrate, but significant only for mobilities below 1000 cm2/V s. Raman spectra analysis and correlations established between mobility and microwave loss tangent of the Al2O3 gate dielectric indicate that the charged impurities are located predominantly at the gate dielectric and/or at the gate dielectric/graphene interface and are likely associated with oxygen vacancies.

  12. Recombination of charge carriers on radiation-induced defects in silicon doped by transition metals impurities

    CERN Document Server

    Kazakevich, L A

    2003-01-01

    It has been studied the peculiarities of recombination of nonequilibrium charge carriers on radiation-induced defects in received according to Czochralski method p-silicon (p approx 3 - 20 Ohm centre dot cm), doped by one of the impurities of transition metals of the IV-th group of periodic table (titanium, zirconium, hafnium). Experimental results are obtained out of the analysis of temperature and injection dependence of the life time of charge carriers. The results are explained taking into consideration the influences of elastic stress fields created by the aggregates of transition metals atoms on space distribution over the crystal of oxygen and carbon background impurities as well as on the migration of movable radiation-induced defects during irradiation. (authors).

  13. Carrier-interleaved orthogonal multi-electrode multi-carrier resistivity-measurement tool

    Science.gov (United States)

    Cai, Yu; Sha, Shuang

    2016-09-01

    This paper proposes a new carrier-interleaved orthogonal multi-electrode multi-carrier resistivity-measurement tool used in a cylindrical borehole environment during oil-based mud drilling processes. The new tool is an orthogonal frequency division multiplexing access-based contactless multi-measurand detection tool. The tool can measure formation resistivity in different azimuthal angles and elevational depths. It can measure many more measurands simultaneously in a specified bandwidth than the legacy frequency division multiplexing multi-measurand tool without a channel-select filter while avoiding inter-carrier interference. The paper also shows that formation resistivity is not sensitive to frequency in certain frequency bands. The average resistivity collected from N subcarriers can increase the measurement of the signal-to-noise ratio (SNR) by N times given no amplitude clipping in the current-injection electrode. If the clipping limit is taken into account, with the phase rotation of each single carrier, the amplitude peak-to-average ratio can be reduced by 3 times, and the SNR can achieve a 9/N times gain over the single-carrier system. The carrier-interleaving technique is also introduced to counter the carrier frequency offset (CFO) effect, where the CFO will cause inter-pad interference. A qualitative analysis and simulations demonstrate that block-interleaving performs better than tone-interleaving when coping with a large CFO. The theoretical analysis also suggests that increasing the subcarrier number can increase the measurement speed or enhance elevational resolution without sacrificing receiver performance. The complex orthogonal multi-pad multi-carrier resistivity logging tool, in which all subcarriers are complex signals, can provide a larger available subcarrier pool than other types of transceivers.

  14. Oxygen therapy reduces postoperative tachycardia

    DEFF Research Database (Denmark)

    Stausholm, K; Kehlet, H; Rosenberg, J

    1995-01-01

    Concomitant hypoxaemia and tachycardia in the postoperative period is unfavourable for the myocardium. Since hypoxaemia per se may be involved in the pathogenesis of postoperative tachycardia, we have studied the effect of oxygen therapy on tachycardia in 12 patients randomly allocated to blinded...... air or oxygen by facemask on the second or third day after major surgery. Inclusion criteria were arterial hypoxaemia (oxygen saturation 90 beat.min-1). Each patient responded similarly to oxygen therapy: an increase in arterial oxygen saturation and a decrease...... in heart rate (p oxygen has a positive effect on the cardiac oxygen delivery and demand balance....

  15. Hyperbaric oxygen and radiotherapy

    International Nuclear Information System (INIS)

    Background: Hyperbaric oxygen (HBO) therapy is the inhalation of 100% oxygen at a pressure of at least 1.5 atmospheres absolute (150 kPa). It uses oxygen as a drug by dissolving it in the plasma and delivering it to the tissues independent of hemoglobin. For a variety of organ systems, HBO is known to promote new vessel growth into areas with reduced oxygen tension due to poor vascularity, and therewith promotes wound healing and recovery of radiation-injured tissue. Furthermore, tumors may be sensitized to irradiation by raising intratumoral oxygen tensions. Methods: A network of hyperbaric facilities exists in Europe, and a number of clinical studies are ongoing. The intergovernmental framework COST B14 action 'Hyperbaric Oxygen Therapy' started in 1999. The main goal of the Working Group Oncology is preparation and actual implementation of prospective study protocols in the field of HBO and radiation oncology in Europe. Results: In this paper a short overview on HBO is given and the following randomized clinical studies are presented: (a) reirradiation of recurrent squamous cell carcinoma of the head and neck after HBO sensitization; (b) role of HBO in enhancing radiosensitivity on glioblastoma multiforme; (c) osseointegration in irradiated patients; adjunctive HBO to prevent implant failures; (d) the role of HBO in the treatment of late irradiation sequelae in the pelvic region. The two radiosensitization protocols (a, b) allow a time interval between HBO and subsequent irradiation of 10-20 min. Conclusion: Recruitment of centers and patients is being strongly encouraged, detailed information is given on www.oxynet.org. (orig.)

  16. Hyperbaric oxygen and radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, R. [Medical Univ. of Graz (Austria). Dept. of Radiation; Hamilton-Farrell, M.R. [Whipps Cross Hospital, Leytonstone, London (United Kingdom). Hyperbaric Unit; Kleij, A.J. van der [Academic Medical Center, Amsterdam (NL). Dept. of Surgery] [and others

    2005-02-01

    Background: Hyperbaric oxygen (HBO) therapy is the inhalation of 100% oxygen at a pressure of at least 1.5 atmospheres absolute (150 kPa). It uses oxygen as a drug by dissolving it in the plasma and delivering it to the tissues independent of hemoglobin. For a variety of organ systems, HBO is known to promote new vessel growth into areas with reduced oxygen tension due to poor vascularity, and therewith promotes wound healing and recovery of radiation-injured tissue. Furthermore, tumors may be sensitized to irradiation by raising intratumoral oxygen tensions. Methods: A network of hyperbaric facilities exists in Europe, and a number of clinical studies are ongoing. The intergovernmental framework COST B14 action 'Hyperbaric Oxygen Therapy' started in 1999. The main goal of the Working Group Oncology is preparation and actual implementation of prospective study protocols in the field of HBO and radiation oncology in Europe. Results: In this paper a short overview on HBO is given and the following randomized clinical studies are presented: (a) reirradiation of recurrent squamous cell carcinoma of the head and neck after HBO sensitization; (b) role of HBO in enhancing radiosensitivity on glioblastoma multiforme; (c) osseointegration in irradiated patients; adjunctive HBO to prevent implant failures; (d) the role of HBO in the treatment of late irradiation sequelae in the pelvic region. The two radiosensitization protocols (a, b) allow a time interval between HBO and subsequent irradiation of 10-20 min. Conclusion: Recruitment of centers and patients is being strongly encouraged, detailed information is given on www.oxynet.org. (orig.)

  17. Transparent anodes for polymer photovoltaics: Oxygen permeability of PEDOT

    DEFF Research Database (Denmark)

    Andersen, M.; Carlé, Jon Eggert; Cruys-Bagger, N.;

    2007-01-01

    The oxygen permeability of the transparent organic anode poly(3,4,-ethylene dioxythiophene) with paratoluenesulphonate as the anion (PEDOT:pTS) was determined to be 2.5 +/- 0.7 x 10(-15) cm(3) (STP) CM cm(-2) S-1 Pa-1, and is thus comparable in magnitude to the oxygen permeability of polyethylene......The oxygen permeability of the transparent organic anode poly(3,4,-ethylene dioxythiophene) with paratoluenesulphonate as the anion (PEDOT:pTS) was determined to be 2.5 +/- 0.7 x 10(-15) cm(3) (STP) CM cm(-2) S-1 Pa-1, and is thus comparable in magnitude to the oxygen permeability...... of polyethyleneterephthalate (PET). The oxygen diffusion through bilayers of polyethylene (PE) and PEDOT:pTS and bilayers of PET and PEDOT:pTS was established. The bilayer structures were applied as the carrier substrate and the transparent anode in polymer-based photovoltaic devices employing a mixture of poly(1-methoxy-4......-(2-ethylhexyloxy)-p-phenylenevinylene) (MEH-PPV) and [6,6]-phenyt-C-61-butanoicacidmethylester (PCBM) as the active layer and aluminium as the cathode. The oxygen permeability of the layers and the aluminium cathode was correlated with the lifetime of the solar cell devices. It was found that the performance...

  18. Benchmark and gap analysis of current mask carriers vs future requirements: example of the carrier contamination

    Science.gov (United States)

    Fontaine, H.; Davenet, M.; Cheung, D.; Hoellein, I.; Richsteiger, P.; Dejaune, P.; Torsy, A.

    2007-02-01

    In the frame of the European Medea+ 2T302 MUSCLE project, an extensive mask carriers benchmark was carried out in order to evaluate whether some containers answer to the 65nm technology needs. Ten different containers, currently used or expected in the future all along the mask supply chain (blank, maskhouse and fab carriers) were selected at different steps of their life cycle (new, aged, aged & cleaned). The most critical parameters identified for analysis versus future technologies were: automation, particle contamination, chemical contamination (organic outgassing, ionic contamination), cleanability, ESD, airtightness and purgeability. Furthermore, experimental protocols corresponding to suitable methods were then developed and implemented to test each criterion. The benchmark results are presented giving a "state of the art" of mask carriers currently available and allowing a gap analysis for the tested parameters related to future needs. This approach is detailed through the particular case of carrier contamination measurements. Finally, this benchmark / gap analysis leads to propose advisable mask carrier specifications (and the test protocols associated) on various key parameters which can also be taken as guidelines for a standardization perspective for the 65nm technology. This also indicates that none of tested carriers fulfills all the specifications proposed.

  19. Electrical property studies of oxygen in Czochralski-grown neutron-transmutation-doped silicon

    International Nuclear Information System (INIS)

    Electically active oxygen-related donors can be formed in Czochralski (Cz) Si either during crystal growth or during subsequent heat treatment; conventional n- or p-type dopant carrier concentrations are altered if these oxygen donors are present. Neutron transmutation doping (NTD) has been used to introduce a uniform concentration of 31P in Si. However, oxygen donors can also be formed in NTD Cz Si during the process of annealing to remove NTD radiation damage. In the present experiments, the carrier concentration of Cz and NTD Cz Si samples was determined as a function of the initial dopant, oxygen, and 31P concentration before and after isothermal or isochronal annealing. It is shown that low temperature (350 to 5000C) heat treatment can introduce a significant oxygen donor concentration in Cz Si and in NTD Cz Si that contains radiation-induced lattice defects. Intermediate temperature (550 to 7500C) heat treatment, which is intended to remove oxygen donors or lattice defects, can introduce other oxygen donors; annealing above 7500C is required to remove any of these oxygen donors. Extended (20 h) high-temperature (1000 to 12000C) annealing can remove oxygen donors and lattice defects, but a significant concentration of oxygen donors can still be introduced by subsequent low temperature heat treatment. These results suggest that oxygen-related donor formation in NTD Cz Si at temperatures below 7500C may serve to mask any annealing study of lattice defects. It is concluded that annealing for 30 min at 7500C is sufficient to remove radiation damage in NTD Cz Si when the separate effects of oxygen donor formation are included

  20. Oxygen ion conductors

    Directory of Open Access Journals (Sweden)

    Stephen J Skinner

    2003-03-01

    A very interesting subgroup of this class of materials are the oxides that display oxygen ion conductivity. As well as the intrinsic interest in these materials, there has been a continued drive for their development because of the promise of important technological devices such as the solid oxide fuel cell (SOFC, oxygen separation membranes, and membranes for the conversion of methane to syngas1. All of these devices offer the potential of enormous commercial and ecological benefits provided suitable high performance materials can be developed. In this article we will review the materials currently under development for application in such devices with particular reference to some of the newly discovered oxide ion conductors.

  1. The Appropriate Use of Oxygen

    OpenAIRE

    Lubin, Stan

    1988-01-01

    The scientific evidence for the efficacy of oxygen therapy in acute hypoxemia is limited. In chronic hypoxemia continuous oxygen therapy appears to decrease mortality. Current indications for oxygen treatment are PaO2 less than 60 in acute hypoxemia and less than 55 in chronic hypoxemia. Physical and physiological hazards of oxygen are reviewed. Three syndromes of pulmonary oxygen toxicity are described: tracheobronchitis, adult respiratory distress syndrome, and bronchopulmonary dysplasia.

  2. 48 CFR 1615.470 - Carrier investment of FEHB funds.

    Science.gov (United States)

    2010-10-01

    ... CONTRACTING BY NEGOTIATION Contract Pricing 1615.470 Carrier investment of FEHB funds. (a) Except for contracts based on a combination of cost and price analysis (community-rated), the carrier is required...

  3. Carrier cultures of simian foamy virus.

    Science.gov (United States)

    Clarke, J K; Samuels, J; Dermott, E; Gay, F W

    1970-05-01

    The production of cultures of HEp-2 and BHK-21 cells persistently infected with a type 1 simian foamy virus is described. After infection, HEp-2 cells showed no structural changes, whereas BHK-21 cells lost their normal spindle shape and showed mitochondrial damage, and some cells contained many lysosomes. Thin sections also showed that a few BHK-21 cells contained virus particles in low concentration, and infectious virus could be isolated from both the cells and the supernatant fluid. No virus was seen in thin sections of HEp-2 cells, although infectious virus in low titer could be recovered intermittently from lysed cells. Both carrier cultures were immune to challenge with homologous virus and antigen could be detected in over 90% of the cells even after growth for 9 weeks in the presence of virus-neutralizing serum. The distribution of antigen in carrier cultures of both cell types is described and compared with that seen in cytocidal infections. PMID:4986851

  4. Carrier synchronization and detection of polyphase signals.

    Science.gov (United States)

    Lindsey, W. C.; Simon, M. K.

    1972-01-01

    Digital communication networks used for the distribution of high-speed digital information are currently the subject of design studies for many civil and military applications. This paper presents results that are useful in such studies as well as in network planning. In particular, the paper is concerned with the problems of carrier synchronization and noisy reference detection of polyphase signals. Reconstruction of coherent references for the detection of polyphase signals is considered and analyzed for three carrier reconstruction loops, namely, Nth power (multiply-and-divide) loops, generalized Costas (I-Q) loops, and extensions of data-aided (modulation wipeoff) loops. General expressions for the error probability are developed when the reconstructed reference signals are noisy.

  5. Superconductivity in carrier-doped silicon carbide

    Directory of Open Access Journals (Sweden)

    Takahiro Muranaka, Yoshitake Kikuchi, Taku Yoshizawa, Naoki Shirakawa and Jun Akimitsu

    2008-01-01

    Full Text Available We report growth and characterization of heavily boron-doped 3C-SiC and 6H-SiC and Al-doped 3C-SiC. Both 3C-SiC:B and 6H-SiC:B reveal type-I superconductivity with a critical temperature Tc=1.5 K. On the other hand, Al-doped 3C-SiC (3C-SiC:Al shows type-II superconductivity with Tc=1.4 K. Both SiC:Al and SiC:B exhibit zero resistivity and diamagnetic susceptibility below Tc with effective hole-carrier concentration n higher than 1020 cm−3. We interpret the different superconducting behavior in carrier-doped p-type semiconductors SiC:Al, SiC:B, Si:B and C:B in terms of the different ionization energies of their acceptors.

  6. Terahertz transport dynamics of graphene charge carriers

    DEFF Research Database (Denmark)

    Buron, Jonas Christian Due

    The electronic transport dynamics of graphene charge carriers at femtosecond (10-15 s) to picosecond (10-12 s) time scales are investigated using terahertz (1012 Hz) time-domain spectroscopy (THz-TDS). The technique uses sub-picosecond pulses of electromagnetic radiation to gauge the electrodynamic...... response of thin conducting films at up to multi-terahertz frequencies. In this thesis THz-TDS is applied towards two main goals; (1) investigation of the fundamental carrier transport dynamics in graphene at femtosecond to picosecond timescales and (2) application of terahertz time-domain spectroscopy...... to rapid and non-contact electrical characterization of large-area graphene, relevant for industrial integration. We show that THz-TDS is an accurate and reliable probe of graphene sheet conductance, and that the technique provides insight into fundamental aspects of the nanoscopic nature of conduction...

  7. Screening-induced carrier transport in silicene

    International Nuclear Information System (INIS)

    Based on the Boltzmann transport equation in the MRT approximation, we present a theory to investigate low-field carrier transport in dual-gated silicene FETs by taking into account screened charged impurity scattering, which is the most likely scattering mechanism limiting the conductivity. Static RPA dielectric screening is also included in the conductivity calculation to study temperature-dependent silicene transport. It is found that both calculated conductivity and band gap not only depend strongly on carrier sheet density, but also depend strongly on effective offset density. More importantly, screening-induced metal-insulator-transition phenomena in buckled silicene can be observed theoretically, which is similar to that obtained in monolayer graphene. (paper)

  8. Experimental distribution of entanglement with separable carriers.

    Science.gov (United States)

    Fedrizzi, A; Zuppardo, M; Gillett, G G; Broome, M A; Almeida, M P; Paternostro, M; White, A G; Paterek, T

    2013-12-01

    The key requirement for quantum networking is the distribution of entanglement between nodes. Surprisingly, entanglement can be generated across a network without direct transfer-or communication-of entanglement. In contrast to information gain, which cannot exceed the communicated information, the entanglement gain is bounded by the communicated quantum discord, a more general measure of quantum correlation that includes but is not limited to entanglement. Here, we experimentally entangle two communicating parties sharing three initially separable photonic qubits by exchange of a carrier photon that is unentangled with either party at all times. We show that distributing entanglement with separable carriers is resilient to noise and in some cases becomes the only way of distributing entanglement through noisy environments.

  9. Protection switching for carrier ethernet multicast

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Berger, Michael Stübert

    2010-01-01

    This paper addresses network survivability for IPTV multicast transport in Carrier Ethernet networks. The impact of link failures is investigated and suggestions for intelligent multicast resilience schemes are proposed. In particular, functions of the multicast tree are integrated with the Carri...... recovery path length, recovery time, number of branch nodes and operational complexity. The integrated approach therefore shows significant potential to increase the QoE for IPTV users in case of network failures and recovery actions....

  10. Nanogel Carrier Design for Targeted Drug Delivery

    OpenAIRE

    Eckmann, D.M.; Composto, R. J.; Tsourkas, A; Muzykantov, V. R.

    2014-01-01

    Polymer-based nanogel formulations offer features attractive for drug delivery, including ease of synthesis, controllable swelling and viscoelasticity as well as drug loading and release characteristics, passive and active targeting, and the ability to formulate nanogel carriers that can respond to biological stimuli. These unique features and low toxicity make the nanogels a favorable option for vascular drug targeting. In this review, we address key chemical and biological aspects of nanoge...

  11. Software defined networking: meeting carrier grade requirements

    OpenAIRE

    Staessens, Dimitri; Sharma, Sachin; Colle, Didier; Pickavet, Mario; Demeester, Piet

    2011-01-01

    Software Defined Networking is a networking paradigm which allows network operators to manage networking elements using software running on an external server. This is accomplished by a split in the architecture between the forwarding element and the control element. Two technologies which allow this split for packet networks are ForCES and Openflow. We present energy efficiency and resilience aspects of carrier grade networks which can be met by Openflow. We implement flow restoration and ru...

  12. Atlas V Aft Bulkhead Carrier Rideshare System

    OpenAIRE

    Willcox, Maj Travis

    2012-01-01

    This paper gives the background and details of the Atlas V Aft Bulkhead Carrier to be flown on the National Recoinnassance Office Launch 36 with the Operationally Unique Technologies Satellite Auxiliary Payload. The CubeSats included are from a number of labs, universities and government entities for the purpose of technology demonstration, science experimentation and operational proof of concepts. This mission will pave the way for rideshare on NRO missions and other Atlas V launches.

  13. The solute carrier 6 family of transporters

    DEFF Research Database (Denmark)

    Bröer, Stefan; Gether, Ulrik

    2012-01-01

    The solute carrier 6 (SLC6) family of the human genome comprises transporters for neurotransmitters, amino acids, osmolytes and energy metabolites. Members of this family play critical roles in neurotransmission, cellular and whole body homeostasis. Malfunction or altered expression...... of these transporters is associated with a variety of diseases. Pharmacological inhibition of the neurotransmitter transporters in this family is an important strategy in the management of neurological and psychiatric disorders. This review provides an overview of the biochemical and pharmacological properties...

  14. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    Kiilgaard, Jens Folke; Pedersen, D B; Eysteinsson, T;

    2004-01-01

    The authors have previously reported that carbonic anhydrase inhibitors such as acetazolamide and dorzolamide raise optic nerve oxygen tension (ONPO(2)) in pigs. The purpose of the present study was to investigate whether timolol, which belongs to another group of glaucoma drugs called beta...

  15. Calibration Of Oxygen Monitors

    Science.gov (United States)

    Zalenski, M. A.; Rowe, E. L.; Mcphee, J. R.

    1988-01-01

    Readings corrected for temperature, pressure, and humidity of air. Program for handheld computer developed to ensure accuracy of oxygen monitors in National Transonic Facility, where liquid nitrogen stored. Calibration values, determined daily, based on entries of data on barometric pressure, temperature, and relative humidity. Output provided directly in millivolts.

  16. Photoinduced carrier annihilation in silicon pn junction

    Science.gov (United States)

    Sameshima, Toshiyuki; Motoki, Takayuki; Yasuda, Keisuke; Nakamura, Tomohiko; Hasumi, Masahiko; Mizuno, Toshihisa

    2015-08-01

    We report analysis of the photo-induced minority carrier effective lifetime (τeff) in a p+n junction formed on the top surfaces of a n-type silicon substrate by ion implantation of boron and phosphorus atoms at the top and bottom surfaces followed by activation by microwave heating. Bias voltages were applied to the p+ boron-doped surface with n+ phosphorus-doped surface kept at 0 V. The values of τeff were lower than 1 × 10-5 s under the reverse-bias condition. On the other hand, τeff markedly increased to 1.4 × 10-4 s as the forward-bias voltage increased to 0.7 V and then it leveled off when continuous-wave 635 nm light was illuminated at 0.74 mW/cm2 on the p+ surface. The carrier annihilation velocity S\\text{p + } at the p+ surface region was numerically estimated from the experimental τeff. S\\text{p + } ranged from 4000 to 7200 cm/s under the reverse-bias condition when the carrier annihilation velocity S\\text{n + } at the n+ surface region was assumed to be a constant value of 100 cm/s. S\\text{p + } markedly decreased to 265 cm/s as the forward-bias voltage increased to 0.7 V.

  17. Hydrogen as fuel carrier in PEM fuelcell for automobile applications

    Science.gov (United States)

    Sk, Mudassir Ali; Venkateswara Rao, K.; Ramana Rao, Jagirdar V.

    2015-02-01

    The present work focuses the application of nanostructured materials for storing of hydrogen in different carbon materials by physisorption method. To market a hydrogen-fuel cell vehicle as competitively as the present internal combustion engine vehicles, there is a need for materials that can store a minimum of 6.5wt% of hydrogen. Carbon materials are being heavily investigated because of their promise to offer an economical solution to the challenge of safe storage of large hydrogen quantities. Hydrogen is important as a new source of energy for automotive applications. It is clear that the key challenge in developing this technology is hydrogen storage. Combustion of fossil fuels and their overuse is at present a serious concern as it is creates severe air pollution and global environmental problems; like global warming, acid rains, ozone depletion in stratosphere etc. This necessitated the search for possible alternative sources of energy. Though there are a number of primary energy sources available, such as thermonuclear energy, solar energy, wind energy, hydropower, geothermal energy etc, in contrast to the fossil fuels in most cases, these new primary energy sources cannot be used directly and thus they must be converted into fuels, that is to say, a new energy carrier is needed. Hydrogen fuel cells are two to three times more efficient than combustion engines. As they become more widely available, they will reduce dependence on fossil fuels. In a fuel cell, hydrogen and oxygen are combined in an electrochemical reaction that produces electricity and, as a byproduct, water.

  18. Laser energy tuning of carrier effective mass and thermopower in epitaxial oxide thin films

    KAUST Repository

    Abutaha, Anas I.

    2012-04-18

    The effect of the laser fluence on high temperature thermoelectric properties of the La doped SrTiO3 (SLTO) thin films epitaxially grown on LaAlO3 〈100〉 substrates by pulsed laser deposition is clarified. It is shown that oxygen vacancies that influence the effective mass of carriers in SLTO films can be tuned by varying the laser energy. The highest power factor of 0.433 W K−1 m−1 has been achieved at 636 K for a filmdeposited using the highest laser fluence of 7 J cm−2 pulse−1.

  19. 14 CFR 252.3 - Smoking ban: air carriers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Smoking ban: air carriers. 252.3 Section... PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.3 Smoking ban: air carriers. Air carriers shall prohibit smoking on all scheduled passenger flights....

  20. 14 CFR 252.5 - Smoking ban: foreign air carriers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Smoking ban: foreign air carriers. 252.5... PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.5 Smoking ban: foreign air carriers. (a) Foreign air carriers shall prohibit smoking on all scheduled passenger flight segments: (1) Between...

  1. Legionella pneumophila Secretes a Mitochondrial Carrier Protein during Infection

    OpenAIRE

    Pavel Dolezal; Margareta Aili; Janette Tong; Jhih-Hang Jiang; Marobbio, Carlo M.T.; Sau Fung Lee; Ralf Schuelein; Simon Belluzzo; Eva Binova; Aurelie Mousnier; Gad Frankel; Giulia Giannuzzi; Ferdinando Palmieri; Kipros Gabriel; Thomas Naderer

    2012-01-01

    Author Summary Mitochondrial carrier proteins evolved during endosymbiosis to transport substrates across the mitochondrial inner membrane. As such the proteins are associated exclusively with eukaryotic organisms. Despite this, we identified putative mitochondrial carrier proteins in the genomes of different intracellular bacterial pathogens, including Legionella pneumophila, the causative agent of Legionnaire's disease. We named the mitochondrial carrier protein from L. pneumophila LncP and...

  2. Terahertz carrier dynamics in graphene and graphene nanostructures

    DEFF Research Database (Denmark)

    Jensen, Søren A.; Turchinovich, Dmitry; Tielrooij, Klaas Jan;

    2014-01-01

    Photoexcited charge carriers in 2D graphene and in 1D graphene nanostructures were studied with optical pump-THz probe spectroscopy. We find efficient hot-carrier multiplication in 2D graphene, and predominantly free carrier early time response in 1D nanostructures. © 2014 OSA....

  3. Joint Iterative Carrier Synchronization and Signal Detection for Dual Carrier 448 Gb/s PDM 16-QAM

    DEFF Research Database (Denmark)

    Zibar, Darko; Carvalho, Luis; Estaran Tolosa, Jose Manuel;

    2013-01-01

    Soft decision driven joint carrier synchronization and signal detection, employing expectation maximization, is experimentally demonstrated. Employing soft decisions offers an improvement of 0.5 dB compared to hard decision digital PLL based carrier synchronization and demodulation....

  4. Literature review of the passenger airline business models: Full service carrier, low-cost carrier and charter airlines

    NARCIS (Netherlands)

    Carmona Benitez, R.B.; Lodewijks, G.

    2008-01-01

    The deregulation and liberalization of the air transportation industry have developed three main passenger business models: full service carriers, low-cost carriers, and charter airlines. Deregulation removed regulated fares and routes increasing competition and yields. Airlines business models main

  5. Oxygen Depletion in the Interstellar Medium: Implications for Grain Models and the Distribution of Elemental Oxygen

    CERN Document Server

    Whittet, D C B

    2009-01-01

    This paper assesses the implications of a recent discovery (Jenkins 2009) that atomic oxygen is being depleted from diffuse interstellar gas at a rate that cannot be accounted for by its presence in silicate and metallic oxide particles. To place this discovery in context, the uptake of elemental O into dust is considered over a wide range of environments, from the tenuous intercloud gas and diffuse clouds sampled by the depletion observations to dense clouds where ice mantles and gaseous CO become important reservoirs of O. The distribution of O in these contrasting regions is quantified in terms of a common parameter, the mean number density of hydrogen. At the interface between diffuse and dense phases (just before the onset of ice mantle growth) as much as 160 ppm of the O abundance is unaccounted for. If this reservoir of depleted oxygen persists to higher densities it has implications for the oxygen budget in molecular clouds, where a shortfall of the same order is observed. Of various potential carrier...

  6. Emergency oxygen: What? Who? When?

    Science.gov (United States)

    Starr, L M

    1994-01-01

    1. While the need for oxygen to support ill or injured clients is well established, confusion exists about oxygen devices and legal and training requirements. 2. The FDA recognizes both emergency and prescription oxygen. Emergency devices may be used legally by a non-health care workplace first aider who has completed a course in oxygen administration. Training sources for oxygen administration training are identified. 3. Workplace first aiders may assist a client and occupational health nurse by administering emergency oxygen. The appropriate use of these devices for cases of cardiac distress/arrest, shock, COPD, and hyperventilation is reviewed. PMID:8147981

  7. Influence of Oxygen Partial Pressure on the Fermi Level of ZnO Films Investigated by Kelvin Probe Force Microscopy

    International Nuclear Information System (INIS)

    The influence of oxygen partial pressure on the Fermi level of ZnO films prepared by pulsed laser deposition is investigated. The contact potential difference of the ZnO films fabricated under various oxygen partial pressures is studied systematically using Kelvin probe force microscopy. The Fermi level shifted by 0.35 eV as oxygen partial pressure increased. This indicates a significant change in the electronic structure and energy balance in ZnO films. This fact provides a consistent explanation that the changes in carrier concentration, resistivity and mobility of ZnO films are attributed to oxygen vacancy induced shift of the Fermi level

  8. Influence of Oxygen Partial Pressure on the Fermi Level of ZnO Films Investigated by Kelvin Probe Force Microscopy

    Science.gov (United States)

    Su, Ting; Zhang, Hai-Feng

    2012-12-01

    The influence of oxygen partial pressure on the Fermi level of ZnO films prepared by pulsed laser deposition is investigated. The contact potential difference of the ZnO films fabricated under various oxygen partial pressures is studied systematically using Kelvin probe force microscopy. The Fermi level shifted by 0.35 eV as oxygen partial pressure increased. This indicates a significant change in the electronic structure and energy balance in ZnO films. This fact provides a consistent explanation that the changes in carrier concentration, resistivity and mobility of ZnO films are attributed to oxygen vacancy induced shift of the Fermi level.

  9. Core-shell poly-methylmethacrylate nanoparticles as effective carriers of electrostatically loaded anionic porphyrin.

    Science.gov (United States)

    Varchi, Greta; Benfenati, Valentina; Pistone, Assunta; Ballestri, Marco; Sotgiu, Giovanna; Guerrini, Andrea; Dambruoso, Paolo; Liscio, Andrea; Ventura, Barbara

    2013-05-01

    Among the medical applications of nanoparticles, their usage as photosensitizer (PS) carriers for photodynamic therapy (PDT) has attracted increasing attention. In the present study we explored the morphological and photophysical properties of core-shell PMMA nanoparticles (PMMA-NPs) electrostatically post-loaded with the synthetic, water soluble 5,10,15,20-tetrakis(4-sulphonatophenyl)-porphyrin (TPPS4). pH response and singlet oxygen analyses of differently loaded samples proved the high capability of the PMMA-NPs to shield the PS from the environment, while retaining the PS singlet oxygen production capability. Preliminary in vitro imaging and phototoxicity experiments on HepG2 cells demonstrated the efficacy of the system to trigger photoinduced cell death in the culture.

  10. Promotion of multi-electron transfer for enhanced photocatalysis: A review focused on oxygen reduction reaction

    Science.gov (United States)

    Wang, Changhua; Zhang, Xintong; Liu, Yichun

    2015-12-01

    Semiconductor photocatalysis has attracted significant interest for solar light induced environmental remediation and solar fuel generation. As is well known, photocatalytic performance is determined by three steps: photoexcitation, separation and transport of photogenerated charge carriers, and surface reactions. To achieve higher efficiency, significant efforts have been made on improvement of efficiency of above first two steps, which have been well documented in recent review articles. In contrast, this review intends to focus on strategies moving onto the third step of improvement for enhanced photocatalysis wherein active oxygen species including superoxide radical, hydrogen peroxide, hydroxyl radical are in situ detected. Particularly, surface electron-transfer reduction of oxygen over single component photocatalysts is reviewed and systems enabling multi-electron transfer induced oxygen reduction reaction (ORR) are highlighted. It is expected this review could provide a guideline for readers to better understand the critical role of ORR over photocatalyst in charge carrier separation and transfer and obtain reliable results for enhanced aerobic photocatalysis.

  11. High temperature thermoelectric properties of strontium titanate thin films with oxygen vacancy and niobium doping

    KAUST Repository

    Kumar, Sunil R Sarath

    2013-08-14

    We report the evolution of high temperature thermoelectric properties of SrTiO3 thin films doped with Nb and oxygen vacancies. Structure-property relations in this important thermoelectric oxide are elucidated and the variation of transport properties with dopant concentrations is discussed. Oxygen vacancies are incorporated during growth or annealing in Ar/H2 above 800 K. An increase in lattice constant due to the inclusion of Nb and oxygen vacancies is found to result in an increase in carrier density and electrical conductivity with simultaneous decrease in carrier effective mass and Seebeck coefficient. The lattice thermal conductivity at 300 K is found to be 2.22 W m-1 K-1, and the estimated figure of merit is 0.29 at 1000 K. © 2013 American Chemical Society.

  12. The determining factor for interstitial oxygen formation in Ruddlesden-Popper type La2NiO4-based oxides.

    Science.gov (United States)

    Nakamura, Takashi; Oike, Ryo; Ling, Yihan; Tamenori, Yusuke; Amezawa, Koji

    2016-01-21

    The interstitial oxygen formation mechanism in La2NiO4-based oxides was studied using soft X-ray absorption spectroscopy. When the interstitial oxygen concentration increased, the pre-edge peak of O K-edge spectra increased while Ni L-edge spectra was almost invariant. These spectral changes strongly suggest the significant contribution of ligand oxygen to interstitial oxygen formation by providing/accepting electronic charge carriers. The variation of the integrated peak intensity of the O K-edge strongly suggests that interstitial oxygen formation is determined by the equilibrium unoccupied pDOS of ligand oxygen. From this hypothesis, we propose that modulating the electronic structure is the key to control the capability of interstitial oxygen formation in La2NiO4-based oxides.

  13. 42 CFR 414.226 - Oxygen and oxygen equipment.

    Science.gov (United States)

    2010-10-01

    ... different for stationary oxygen equipment than for portable oxygen equipment, the flow rate for the stationary equipment is used. (ii) If the prescribed flow rate is different for the patient at rest than for... amounts are separately calculated for the following items: (i) Stationary oxygen equipment and...

  14. Oxygen Reduction on Platinum

    DEFF Research Database (Denmark)

    Nesselberger, Markus

    of instrument automation and online data treatment, and provides welldefined mass transport conditions enabling kinetic measurements. A modified electrochemical / spectroscopic interface is presented allowing the exclusive investigation of the Pt/C catalyst layer. Three types of potential dependent adsorption...... effect and anion adsorption on the performance of Pt based electrocatalysts. The anion adsorption is additionally studied by in situ electrochemical infrared spectroscopy during the oxygen reduction reaction (ORR). For this purpose an in situ FTIR setup in attenuated total refection (ATR) configuration....... The influence of the ion adsorption strength, which is observed in the “particle size studies” on the oxygen reduction rate on Pt/C catalysts, is further investigated under similar reaction conditions by infrared spectroscopy. The designed in situ electrochemical ATR-FTIR setup features a high level...

  15. Cerebral oxygenation after birth

    DEFF Research Database (Denmark)

    Hessel, Trine W; Hyttel-Sorensen, Simon; Greisen, Gorm

    2014-01-01

    AIM: To compare absolute values of regional cerebral tissue oxygenation (cStO2 ) during haemodynamic transition after birth and repeatability during steady state for two commercial near-infrared spectroscopy (NIRS) devices. METHODS: In a prospective observational study, the INVOS 5100C and FORE......-SIGHT were compared on 12 term newborns delivered by elective caesarean section. During the 10 min following umbilical cord clamping, cStO2 was measured simultaneously with the neonatal sensors from each device. Repeated measurements were taken the following day. RESULTS: Three and 8 min after clamping......: The INVOS and FORE-SIGHT cStO2 estimates showed oxygenation-level-dependent difference during birth transition. The better repeatability of FORE-SIGHT could be due to the lower response to change in saturation....

  16. High pressure oxygen furnace

    Science.gov (United States)

    Morris, Donald E.

    1992-01-01

    A high temperature high pressure oxygen furnace having a hybrid partially externally heated construction is disclosed. A metallic bar fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 inch bar stock and has a length of about 17 inches. This bar stock is gun drilled for over 16 inches of its length with 0.400 inch aperture to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the bar is provided with a small support aperture into which both a support and a thermocouple can be inserted. The closed end of the gun drilled bar is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior.

  17. Thermodynamic Analysis and Experimental Investigation into Nonflame Combustion Technology(NFCT) with Thermal Cyclic Carrier

    Institute of Scientific and Technical Information of China (English)

    HE Fang; WANG Hua; DAI Yong-nian

    2004-01-01

    The utilization of fossil fuels causes serious negative impacts on the environment and human life. To mitigate greenhouse gases and other pollutants, a novel combustion process-the nonflame combustion technology with a thermal cyclic carrier of molten salt is introduced. In this technology, a whole combustion is divided into two steps, i.e., the section of producing oxide and the section of combustion. In the first step, oxygen is separated from air, and pure N2 is simultaneously formed which is easily recovered. In the other step, the fuels react with lattice oxygen in the oxides formed in the first step, and at the same time, thermal energy,CO2 and H2O vapor are produced. It is noted that the CO2 is easily separated from water vapor and ultimately captured. Theoretically, there are no environmental-unfriendly gases such as CO2, NOx and SO2 discharged in the whole combustion process. Some metal oxides scattered into molten salts play the roles of oxygen carriers in the combustion system, and they can constantly charge and discharge oxygen element from air to fuels during the combustion process. A nonflame combustion system with Li2CO3+K2CO3+Na2SO4 as the molten salt system, CH4 as the fuel and CuO as the catalyst was experimentally investigated. The experimental results show that the combustion process proceeded as it was theoretically analyzed, and CO2 with a high volume fraction of 77.0%-95.0% and N2 with a high volume fraction of 91.9%-99.3% were obtained. The high concentration of CO2 is favorable for capturing and storing subsequently. Therefore, the potential of reducing CO2 emissions of this nonflame combustion technology is huge.

  18. Oxygen Transport Ceramic Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

    2005-08-01

    The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the previous research, the reference point of oxygen occupancy was determined and verified. In the current research, the oxygen occupancy was investigated at 1200 C as a function of oxygen activity and compared with that at 1000 C. The cause of bumps at about 200 C was also investigated by using different heating and cooling rates during TGA. The fracture toughness of LSFT and dual phase membranes at room temperature is an important mechanical property. Vicker's indentation method was used to evaluate this toughness. Through this technique, a K{sub Ic} (Mode-I Fracture Toughness) value is attained by means of semi-empirical correlations between the indentation load and the length of the cracks emanating from the corresponding Vickers indentation impression. In the present investigation, crack propagation behavior was extensively analyzed in order to understand the strengthening mechanisms involved in the non-transforming La based ceramic composites. Cracks were generated using Vicker's indenter and used to identify and evaluate the toughening mechanisms involved. Preliminary results of an electron microscopy study of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appear to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. Modeling of the isotopic transients on operating membranes (LSCrF-2828 at 900 C) and a ''frozen'' isotope profile have been analyzed in conjunction with a 1-D model to reveal the gradient in oxygen diffusivity through the membrane under conditions of high chemical gradients.

  19. Oxygen Transport Ceramic Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

    2005-02-01

    The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. The in situ electrical conductivity and Seebeck coefficient measurements were made on LSFT at 1000 and 1200 C over the oxygen activity range from air to 10{sup -15} atm. The electrical conductivity measurements exhibited a p to n type transition at an oxygen activity of 1 x 10{sup -10} at 1000 C and 1 x 10{sup -6} at 1200 C. Thermogravimetric studies were also carried out over the same oxygen activities and temperatures. Based on the results of these measurements, the chemical and mechanical stability range of LSFT were determined and defect structure was established. The studies on the fracture toughness of the LSFT and dual phase membranes exposed to air and N{sub 2} at 1000 C was done and the XRD and SEM analysis of the specimens were carried out to understand the structural and microstructural changes. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affect the mechanical properties. A complete transformation of fracture behavior was observed in the N{sub 2} treated LSFT samples. Further results to investigate the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appear to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. Recent results on transient kinetic data are presented. The 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model is used to study ''frozen'' profiles in patterned or composite membranes.

  20. Carrier Transport Mechanism in Single Crystalline Organic Semiconductor Thin Film Elucidated by Visualized Carrier Motion.

    Science.gov (United States)

    Matsubara, Kohei; Abe, Kentaro; Manaka, Takaaki; Iwamoto, Mitsumasa

    2016-04-01

    Time-resolved microscopic second harmonic generation (TRM-SHG) measurement was conducted to evaluate temperature dependence of the anisotropic carrier transport process in 6,13-Bis(triisopropylsilylethynyl) (TIPS) pentacene single crystalline domains for two orthogonal directions. Enhancement of the electric field induced SHG (EFI-SHG) signal at the electrode edge at low temperature suggests the presence of potential drop in the injection process. We directly evaluated temperature dependence of the carrier mobility by taking into account the potential drop, and concluded that the Marcus theory is appropriate to interpret the carrier transport in anisotropic TIPS pentacene thin film. TRM-SHG method is a facile and effective way to directly visualize transport process in anisotropic materials and to evaluate injection and transport processes simultaneously. PMID:27451638

  1. Effect of surface stoichiometry and interfacial interactions on ultrafast carrier dynamics of crystalline CdTe (Presentation Recording)

    Science.gov (United States)

    He, Xing; Punpongjareorn, Napat; Wu, Chengyi; Rajagopal, Karjini; Yang, Ding-Shyue

    2015-08-01

    To improve the efficiency of optoelectronic devices, it is critical to understand the carrier dynamics of photoactive materials and the mechanisms involved, including those effects caused by different surface stoichiometry and/or interfacial interactions. A good example is CdTe, which exhibits cost-effective high performance in thin-film photovoltaic cells; it is also known to show surface oxidation, which may affect device efficiency and hence limit the production methods used. In this contribution, we present ultrafast carrier dynamics of crystalline CdTe specimens with different surface conditions using transient reflectivity measurements, following a femtosecond above-gap excitation. The distinct differences observed in the dynamics and the time constants for oxidized and stoichiometrically restored specimens indicate the major role of surface tellurium oxide on the relaxation of photoinduced carriers. The much slower recovery observed on oxidized surfaces is attributed to a transfer (and trapping) of electrons to the tellurium atoms with a high oxidation state, which signifies a charge separation near the surface. To distinguish the effect caused by oxygen adsorption, we also examined the carrier dynamics of CdTe surfaces covered by a thin layer of water molecules for comparison. These results, which show clear interfacial effects, may have broader implications for the understanding of carrier dynamics in nanostructured and polycrystalline specimens under different chemical environments, as such materials exhibit a high surface-to-volume ratio.

  2. Evolution of Oxygenic Photosynthesis

    Science.gov (United States)

    Fischer, Woodward W.; Hemp, James; Johnson, Jena E.

    2016-06-01

    The origin of oxygenic photosynthesis was the most important metabolic innovation in Earth history. It allowed life to generate energy and reducing power directly from sunlight and water, freeing it from the limited resources of geochemically derived reductants. This greatly increased global primary productivity and restructured ecosystems. The release of O2 as an end product of water oxidation led to the rise of oxygen, which dramatically altered the redox state of Earth's atmosphere and oceans and permanently changed all major biogeochemical cycles. Furthermore, the biological availability of O2 allowed for the evolution of aerobic respiration and novel biosynthetic pathways, facilitating much of the richness we associate with modern biology, including complex multicellularity. Here we critically review and synthesize information from the geological and biological records for the origin and evolution of oxygenic photosynthesis. Data from both of these archives illustrate that this metabolism first appeared in early Paleoproterozoic time and, despite its biogeochemical prominence, is a relatively late invention in the context of our planet's history.

  3. Ancient Oceans Had Less Oxygen

    Science.gov (United States)

    King, Angela G.

    2004-01-01

    The amount of dissolved oxygen in the oceans in the mid-Proterozoic period has evolutionary implications since essential trace metals are redox sensitive. The findings suggest that there is global lack of oxygen in seawater.

  4. SINGLET OXYGEN IN NATURAL WATERS

    Science.gov (United States)

    Singlet oxygen is a reactive, electronically excited form of molecular oxygen that rapidly oxidizes a wide variety of organic substances, such as the polycyclic aromatics in petroleum hydrocarbon and the amino acids, histidine, tryptophan, and methionine. Studies of water samples...

  5. Oxygen-Methane Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Orion Propulsion, Inc. proposes to develop an Oxygen and Methane RCS Thruster to advance the technology of alternate fuels. A successful Oxygen/CH4 RCS Thruster...

  6. Electrical and structural properties of diamond films implanted by various doses of oxygen ions

    Institute of Scientific and Technical Information of China (English)

    Hu Xiao-Jun; Ye Jian-Song; Zheng Guo-Qu; Cao Hua-Zhen; Tan Hong-Chuan

    2006-01-01

    Oxygen-doped diamond films are prepared by implanting various dose oxygen ions into the diamond films synthesized by hot filament chemical vapour deposition, and their electrical and structural properties are investigated. Hall effect measurements show that lower dose xygen ion implantation is beneficial to preparing n-type diamonds. The carrier concentration increases with the dose increasing, indicating that oxygen ions supply electrons to the diamonds.The results of AES spectrum indicate that oxygen ions are doped into the diamond films, and the O-implanted depth is around 0.1μm. Raman spectrum measurements indicate that the lower dose oxygen ion implantation at 1014 cm-2or 1015 cm-2 is favourable for producing less damaged O-doped diamond films.

  7. Self-Monitoring Artificial Red Cells with Sufficient Oxygen Supply for Enhanced Photodynamic Therapy

    Science.gov (United States)

    Luo, Zhenyu; Zheng, Mingbin; Zhao, Pengfei; Chen, Ze; Siu, Fungming; Gong, Ping; Gao, Guanhui; Sheng, Zonghai; Zheng, Cuifang; Ma, Yifan; Cai, Lintao

    2016-03-01

    Photodynamic therapy has been increasingly applied in clinical cancer treatments. However, native hypoxic tumoural microenvironment and lacking oxygen supply are the major barriers hindering photodynamic reactions. To solve this problem, we have developed biomimetic artificial red cells by loading complexes of oxygen-carrier (hemoglobin) and photosensitizer (indocyanine green) for boosted photodynamic strategy. Such nanosystem provides a coupling structure with stable self-oxygen supply and acting as an ideal fluorescent/photoacoustic imaging probe, dynamically monitoring the nanoparticle biodistribution and the treatment of PDT. Upon exposure to near-infrared laser, the remote-triggered photosensitizer generates massive cytotoxic reactive oxygen species (ROS) with sufficient oxygen supply. Importantly, hemoglobin is simultaneously oxidized into the more active and resident ferryl-hemoglobin leading to persistent cytotoxicity. ROS and ferryl-hemoglobin synergistically trigger the oxidative damage of xenograft tumour resulting in complete suppression. The artificial red cells with self-monitoring and boosted photodynamic efficacy could serve as a versatile theranostic platform.

  8. A first-principle investigation of the oxygen defects in Si3N4-based charge trapping memories

    International Nuclear Information System (INIS)

    Based on first principle calculations, a comprehensive study of substitutional oxygen defects in hexagonal silicon nitride (β-Si3N4) has been carried out. Firstly, it is found that substitutional oxygen is most likely to form clusters at three sites in Si3N4 due to the intense attractive interaction between oxygen defects. Then, by using three analytical tools (trap energy, modified Bader analysis and charge density difference), we discuss the trap abilities of the three clusters. The result shows that each kind of cluster at the three specific sites presents very different abilities to trap charge carriers (electrons or holes): two of the three clusters can trap both kinds of charge carriers, confirming their amphoteric property; While the last remaining one is only able to trap hole carriers. Moreover, our studies reveal that the three clusters differ from each other in terms of endurance during the program/erase progress. Taking full account of capturing properties for the three oxygen clusters, including trap ability and endurance, we deem holes rather than electrons to be optimal to act as operational charge carriers for the oxygen defects in Si3N4-based charge trapping memories. (semiconductor devices)

  9. Carbon-neutral fuels and energy carriers

    CERN Document Server

    Muradov, Nazim Z

    2011-01-01

    Concerns over an unstable energy supply and the adverse environmental impact of carbonaceous fuels have triggered considerable efforts worldwide to find carbon-free or low-carbon alternatives to conventional fossil fuels. Carbon-Neutral Fuels and Energy Carriers emphasizes the vital role of carbon-neutral energy sources, transportation fuels, and associated technologies for establishing a sustainable energy future. Each chapter draws on the insight of world-renowned experts in such diverse fields as photochemistry and electrochemistry, solar and nuclear energy, biofuels and synthetic fuels, ca

  10. Car Carrier 5.800 TPM

    OpenAIRE

    López de Rojas, Carmen

    2012-01-01

    Tipo de Buque: Car Carrier. Capacidad de carga: carga 1: 3000 coches sin trailers. Carga 2: Carga combinada para 1500 ml de trailers y coches en el resto de las cubiertas del buque no ocupadas por los trailers. Peso muerto 5800 TPM. Capacidad de conductores: 100 personas en camarotes dobles. Sociedad de clasificación: Det Norske Veritas. Reglamentos: Solas, Marpol, Convenio de líneas de carga. Velocidad: 19 nudos al 85% MCR en pruebas. Autonomía: 4500 millas al 80% MCR y 15% al margen de mar....

  11. Oxygen Transport Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay

    2008-08-30

    The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the

  12. Oxygen Transport Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay

    2008-08-30

    The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the

  13. Mixed oxygen ion/electron-conducting ceramics for oxygen separation

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, J.W.; Armstrong, T.R.; Armstrong, B.L. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-08-01

    Mixed oxygen ion and electron-conducting ceramics are unique materials that can passively separate high purity oxygen from air. Oxygen ions move through a fully dense ceramic in response to an oxygen concentration gradient, charge-compensated by an electron flux in the opposite direction. Compositions in the system La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y{minus}z}Fe{sub y}N{sub z}O{sub 3{minus}{delta}}, perovskites where M=Sr, Ca, and Ba, and N=Mn, Ni, Cu, Ti, and Al, have been prepared and their electrical, oxygen permeation, oxygen vacancy equilibria, and catalytic properties evaluated. Tubular forms, disks, and asymmetric membrane structures, a thin dense layer on a porous support of the same composition, have been fabricated for testing purposes. In an oxygen partial gradient, the passive oxygen flux through fully dense structures was highly dependent on composition. An increase in oxygen permeation with increased temperature is attributed to both enhanced oxygen vacancy mobility and higher vacancy populations. Highly acceptor-doped compositions resulted in oxygen ion mobilities more than an order of magnitude higher than yttria-stabilized zirconia. The mixed conducting ceramics have been utilized in a membrane reactor configuration to upgrade methane to ethane and ethylene. Conditions were established to balance selectivity and throughput in a catalytic membrane reactor constructed from mixed conducting ceramics.

  14. 76 FR 5424 - Motor Carrier Safety Advisory Committee; Request for Nominations

    Science.gov (United States)

    2011-01-31

    ... Federal Motor Carrier Safety Administration Motor Carrier Safety Advisory Committee; Request for Nominations AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Request for Nominations to the Motor Carrier Safety Advisory Committee (MCSAC). SUMMARY: The FMCSA solicits nominations...

  15. Limitations of potentiometric oxygen sensors operating at low oxygen levels

    DEFF Research Database (Denmark)

    Lund, Anders; Jacobsen, Torben; Hansen, Karin Vels;

    2011-01-01

    The electrochemical processes that limit the range of oxygen partial pressures in which potentiometric oxygen sensors can be used, were analysed using a theoretical and an experimental approach. Electrochemical impedance spectroscopy was performed on porous Pt/yttria stabilised zirconia (YSZ......) electrodes between 10−6 and 0.2 bar and at temperatures between 500 and 950 °C. The flow of oxide ions and electron holes through a sensor cell, with a YSZ electrolyte, were calculated under similar conditions. The oxygen permeation of the sensor cell was insignificant at an oxygen partial pressure of 10...... that gas phase mass transport processes were dominating. The time constant of the gas phase mass transport processes was found to be inversely proportional to the oxygen partial pressure. The response time of these processes therefore limits the oxygen partial pressure range in which potentiometric oxygen...

  16. Production of Solid sustainable Energy Carriers from biomass by means of TORrefaction (SECTOR)

    Energy Technology Data Exchange (ETDEWEB)

    Witt, Janet; Bienert, Kathrin [DBFZ Deutsches Biomasseforschungszentrum gemeinnuetzige GmbH, Leipzig (Germany). Bereich Bioenergiesysteme; Zwart, Robin; Kiel, Jaap; Englisch, Martin; Wojcik, Magdalena

    2012-07-01

    SECTOR is a large-scale European project with a strong consortium of over 20 partners from industry and science. The project is focussed on the further development of torrefaction-based technologies for the production of solid bioenergy carriers up to pilot-plant scale and beyond, and on supporting the market introduction of torrefaction-based bioenergy carriers as a commodity renewable solid fuel. The torrefaction of biomass materials is considered to be a very promising technology for the promotion of the large-scale implementation of bioenergy. During torrefaction biomass is heated up in the absence of oxygen to a temperature of 250-320 C. By combining torrefaction with pelletisation or briquetting, biomass materials can be converted into a high-energy-density commodity solid fuel or bioenergy carrier with improved behaviour in (long-distance) transport, handling and storage, and also with superior properties in many major end-use applications. Torrefaction has the potential to provide a significant contribution to an enlarged raw material portfolio for biomass fuel production inside Europe by including both agricultural and forestry biomass. In this way, the SECTOR project is expected to shorten the time-to-market of torrefaction technology and to promote market introduction within stringent sustainability boundary conditions. The European Union provides funding for this project within the Seventh Framework Programme. The project has a duration of 42 months and started in January 2012. (orig.)

  17. Theory of Carrier Phase Ambiguity Resolution

    Institute of Scientific and Technical Information of China (English)

    P. J. G. Teunissen

    2003-01-01

    Carrier phase ambiguity resolution is the key to high precision Global Navigation Satellite System(GNSS) positioning and navigation. It applies to a great variety of current and future models of GPS, modernized GPS and Galileo. A proper handling of carrier phase ambiguity resolution requires a proper understanding of the underlying theory of integer inference. In this contribution a brief review is given of the probabilistic theory of integer ambiguity estimation. We describe the concept of ambiguity pull-in regions, introduce the class of admissible integer estimators, determine their probability mass functions and show how their variability solution. The theory is worked out in more detail for integer least-squares and integer bootstrapping. It is shown that the integer least-squares principle maximizes the probability of correct integer estimation. Sharp and easy-to-compute bounds are given for both the ambiguity success rate and the baseline's probability of concentration. Finally the probability density function of the ambiguity residuals is determined. This allows one for the first time to formulate rigorous tests for the integerness of the parameters.

  18. Localized charge carriers in graphene nanodevices

    Energy Technology Data Exchange (ETDEWEB)

    Bischoff, D., E-mail: dominikb@phys.ethz.ch; Varlet, A.; Simonet, P.; Eich, M.; Overweg, H. C.; Ihn, T.; Ensslin, K. [Solid State Physics Laboratory, ETH Zurich, 8093 Zurich (Switzerland)

    2015-09-15

    Graphene—two-dimensional carbon—is a material with unique mechanical, optical, chemical, and electronic properties. Its use in a wide range of applications was therefore suggested. From an electronic point of view, nanostructured graphene is of great interest due to the potential opening of a band gap, applications in quantum devices, and investigations of physical phenomena. Narrow graphene stripes called “nanoribbons” show clearly different electronical transport properties than micron-sized graphene devices. The conductivity is generally reduced and around the charge neutrality point, the conductance is nearly completely suppressed. While various mechanisms can lead to this observed suppression of conductance, disordered edges resulting in localized charge carriers are likely the main cause in a large number of experiments. Localized charge carriers manifest themselves in transport experiments by the appearance of Coulomb blockade diamonds. This review focuses on the mechanisms responsible for this charge localization, on interpreting the transport details, and on discussing the consequences for physics and applications. Effects such as multiple coupled sites of localized charge, cotunneling processes, and excited states are discussed. Also, different geometries of quantum devices are compared. Finally, an outlook is provided, where open questions are addressed.

  19. Influence of carrier on the performance of dry powder inhalers.

    Science.gov (United States)

    Saint-Lorant, G; Leterme, P; Gayot, A; Flament, M P

    2007-04-01

    The aim of this work is to study carriers which can become alternatives to monohydrate lactose in dry powder inhalers and to consider particle parameters that influence adhesion between drug and carrier in dry powder inhalers. Different forms of mannitol, lactose and maltitol were mixed with either terbutaline sulphate or formoterol fumarate. The blends were submitted to different adhesion tests where drug detachment from the carrier was obtained either through mechanical vibration or by aspiration. Parameters like particle shape, roughness, amorphous content and cristalline form may affect interactions between drug and carrier. In our case, crystallized forms of the carrier offered lower adhesion but better release of the active ingredient than spray-dried forms. The crystallized mannitol produced maximal fine particle dose. The blends of the mannitols and the two active ingredients gave different results. The two techniques used to assess the adhesion of drugs to carrier particles provide complementary information about drug/carrier interactions and detachment. The mechanical sieving allows to assess blend stability and the air-jet sieving makes it possible to determine how easily the drug separates from carrier. For the drugs tested, the results of fine particle doses are in agreement with the Alpine air-jet sieve results. The tests used are helpful for the choice of a new carrier in the field of the development of new carriers for dry powder inhalers. PMID:17113733

  20. 47 CFR 69.105 - Carrier common line for non-price cap local exchange carriers.

    Science.gov (United States)

    2010-10-01

    ... residential and single-line business lines multiplied by the difference between the residential and single-line business End User Common Line rate cap and the lesser of $6.50 or the non-price cap local exchange... 47 Telecommunication 3 2010-10-01 2010-10-01 false Carrier common line for non-price cap...

  1. Graphene, a material for high temperature devices; intrinsic carrier density, carrier drift velocity, and lattice energy

    CERN Document Server

    Yin, Yan; Wang, Li; Jin, Kuijuan; Wang, Wenzhong

    2016-01-01

    Heat has always been a killing matter for traditional semiconductor machines. The underlining physical reason is that the intrinsic carrier density of a device made from a traditional semiconductor material increases very fast with a rising temperature. Once reaching a temperature, the density surpasses the chemical doping or gating effect, any p-n junction or transistor made from the semiconductor will fail to function. Here, we measure the intrinsic Fermi level (|E_F|=2.93k_B*T) or intrinsic carrier density (n_in=3.87*10^6 cm^-2 K^-2*T^2), carrier drift velocity, and G mode phonon energy of graphene devices and their temperature dependencies up to 2400 K. Our results show intrinsic carrier density of graphene is an order of magnitude less sensitive to temperature than those of Si or Ge, and reveal the great potentials of graphene as a material for high temperature devices. We also observe a linear decline of saturation drift velocity with increasing temperature, and identify the temperature coefficients of ...

  2. Oxygen isotopes and lakes

    OpenAIRE

    Leng, Melanie; Dean, Jonathan

    2014-01-01

    Isotopes are variations of a particular chemical element. It is all to do with the number of neutrons. Oxygen has two main isotopes: 18O which has 10 neutrons and 8 protons; and 16O which has 8 neutrons and 8 protons. Although these variants have a different number of neutrons (and therefore a different atomic mass), the number of protons remains the same, and they are still classed as the same element. Isotopes are analysed in terms of ratios such as 18O/16O which is shortened to δ18O (δ...

  3. Oxygen Isotopes in Meteorites

    Science.gov (United States)

    Clayton, R. N.

    2003-12-01

    Oxygen isotope abundance variations in meteorites are very useful in elucidating chemical and physical processes that occurred during the formation of the solar system (Clayton, 1993). On Earth, the mean abundances of the three stable isotopes are 16O: 99.76%, 17O: 0.039%, and 18O: 0.202%. It is conventional to express variations in abundances of the isotopes in terms of isotopic ratios, relative to an arbitrary standard, called SMOW (for standard mean ocean water), as follows:The isotopic composition of any sample can then be represented by one point on a "three-isotope plot," a graph of δ17O versus δ18O. It will be seen that such plots are invaluable in interpreting meteoritic data. Figure 1 shows schematically the effect of various processes on an initial composition at the center of the diagram. Almost all terrestrial materials lie along a "fractionation" trend; most meteoritic materials lie near a line of "16O addition" (or subtraction). (4K)Figure 1. Schematic representation of various isotopic processes shown on an oxygen three-isotope plot. Almost all terrestrial materials plot along a line of "fractionation"; most primitive meteoritic materials plot near a line of "16O addition." The three isotopes of oxygen are produced by nucleosynthesis in stars, but by different nuclear processes in different stellar environments. The principal isotope, 16O, is a primary isotope (capable of being produced from hydrogen and helium alone), formed in massive stars (>10 solar masses), and ejected by supernova explosions. The two rare isotopes are secondary nuclei (produced in stars from nuclei formed in an earlier generation of stars), with 17O coming primarily from low- and intermediate-mass stars (radiation in the wavelength range 90-100 nm. The reaction proceeds by a predissociation mechanism, in which the excited electronic state lives long enough to have well-defined vibrational and rotational energy levels. As a consequence, the three isotopic species - C16O, C17O

  4. Oxygen therapy in preterm infants.

    Science.gov (United States)

    Cherian, S; Morris, I; Evans, J; Kotecha, S

    2014-06-01

    Despite being the most widely used and vital therapy in neonatology, optimal strategies for the use of oxygen in preterm infants remain controversial. Achieving the balance between attaining adequate tissue oxygenation and avoiding oxygen toxicity is challenging. There remains a paucity of clear evidence based guidance for clinicians on safe oxygen saturation targets. What does seem apparent is that these targets vary over time in the life of a preterm infant. This article summarises the evidence behind current practice of oxygen monitoring and administration from the first few minutes after birth, through to the acute neonatal and later convalescent periods. Finally, we review the use of home oxygen for preterm infants with bronchopulmonary dysplasia including administration and weaning from domically home oxygen.

  5. Oxygen treatment of cluster headache

    DEFF Research Database (Denmark)

    Petersen, Anja S; Barloese, Mads C J; Jensen, Rigmor H

    2014-01-01

    of oxygen treatment. One study is observational and the remaining five are RCTs. Another five studies were on hyperbaric oxygen treatment hereof two case studies. CONCLUSION: Oxygen therapy can be administered at different flow rates. Three studies investigate the effect of low-flow oxygen, 6-7 l....../min, and found a positive response in 56%, 75% and 82%, respectively, of the patients. One study investigates high-flow oxygen, 12 l/min, and found efficacy in 78% of attacks. The effect of hyperbaric oxygen therapy has been investigated in a few small studies and there is evidence only for an acute......PURPOSE: Our aim was to review the existing literature to document oxygen's therapeutic effect on cluster headache. METHOD: A PubMed search resulted in 28 hits, and from these and their references we found in total 11 relevant studies. We included six studies that investigated the efficacy...

  6. Oxygen vacancy clustering and electron localization in oxygen-deficient SrTiO(3): LDA + U study.

    Science.gov (United States)

    Cuong, Do Duc; Lee, Bora; Choi, Kyeong Mi; Ahn, Hyo-Shin; Han, Seungwu; Lee, Jaichan

    2007-03-16

    We find, using a local density approximation +Hubbard U method, that oxygen vacancies tend to cluster in a linear way in SrTiO(3), a prototypical perovskite oxide, accompanied by strong electron localization at the 3d state of the nearby Ti transition metal ion. The vacancy clustering and the associated electron localization lead to a profound impact on materials properties, e.g., the reduction in free-carrier densities, the appearance of characteristic optical spectra, and the decrease in vacancy mobility. The high stability against the vacancy migration also suggests the physical reality of the vacancy cluster.

  7. Reduction of Oxygen Bound with Hemoglobin by Electrolytic Method Using Hydrogen Gas in Phosphate-buffered Solution

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Hemoglobin(Hb) is important as an oxygen carrier.The trace amount of oxygen in Hb was reduced by an electrolytic method using hydrogen as an electron donor.The deoxygenated Hb(deoxyHb) was stable against heat treatment at 60 ℃ with little precipitant.This method is safe,fast,and would be of potential use for large scale purification of Hb.

  8. Accelerated start-up of moving bed biofilm reactor by using a novel suspended carrier with porous surface.

    Science.gov (United States)

    Chen, Xin; Kong, Lingjun; Wang, Xingyu; Tian, Shuanghong; Xiong, Ya

    2015-02-01

    A novel suspended carrier with porous surface was firstly prepared by coating a sponge on the inside and outside of a hard polyethylene ring. Herein the effects of the sponge thickness (0, 2, 4, 6 mm) and pore size (17, 45, 85 pores per inch, ppi) on the performance of the start-up stage in moving bed biofilm reactor (MBBR) were investigated. The results indicated that the home-made carrier with the sponge thickness of 4 mm and the pore size of 45 ppi, defined as SC4-45, showed the best performance, which obtained high biomass concentration of 2,136.6 mg/L, oxygen uptake rate for COD of 150.1 mg O2/h and oxygen uptake rate for NH4(+)-N of 17.4 mg O2/h. The DGGE profiles of the biofilms obtained in SC4-45 and a commercial carrier showed a similar community as the Dice similarity coefficients between two samples was 0.72. Furthermore, 16S rRNA gene sequence analysis reveals dominance of Sphaerotilus sp. and Aeromonas sp. in the community of both samples. Moreover, for the MBBR based on SC4-45, COD and NH4(+)-N removal rates reached 99.5 ± 1.1 and 93.6 ± 2.3 % at the end of the start-up stage, much higher than those of the commercial carrier, 74.9 ± 2.7 and 40.0 ± 1.8 %, respectively. These indicated the novel carrier obtained a quick start-up.

  9. Timescales of Oxygenation Following the Evolution of Oxygenic Photosynthesis.

    Science.gov (United States)

    Ward, Lewis M; Kirschvink, Joseph L; Fischer, Woodward W

    2016-03-01

    Among the most important bioenergetic innovations in the history of life was the invention of oxygenic photosynthesis-autotrophic growth by splitting water with sunlight-by Cyanobacteria. It is widely accepted that the invention of oxygenic photosynthesis ultimately resulted in the rise of oxygen by ca. 2.35 Gya, but it is debated whether this occurred more or less immediately as a proximal result of the evolution of oxygenic Cyanobacteria or whether they originated several hundred million to more than one billion years earlier in Earth history. The latter hypothesis involves a prolonged period during which oxygen production rates were insufficient to oxidize the atmosphere, potentially due to redox buffering by reduced species such as higher concentrations of ferrous iron in seawater. To examine the characteristic timescales for environmental oxygenation following the evolution of oxygenic photosynthesis, we applied a simple mathematical approach that captures many of the salient features of the major biogeochemical fluxes and reservoirs present in Archean and early Paleoproterozoic surface environments. Calculations illustrate that oxygenation would have overwhelmed redox buffers within ~100 kyr following the emergence of oxygenic photosynthesis, a geologically short amount of time unless rates of primary production were far lower than commonly expected. Fundamentally, this result arises because of the multiscale nature of the carbon and oxygen cycles: rates of gross primary production are orders of magnitude too fast for oxygen to be masked by Earth's geological buffers, and can only be effectively matched by respiration at non-negligible O2 concentrations. These results suggest that oxygenic photosynthesis arose shortly before the rise of oxygen, not hundreds of millions of years before it.

  10. OXYGEN TRANSPORT CERAMIC MEMBRANES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2000-10-01

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

  11. OXYGEN ABUNDANCES IN CEPHEIDS

    Energy Technology Data Exchange (ETDEWEB)

    Luck, R. E.; Andrievsky, S. M. [Department of Astronomy, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-7215 (United States); Korotin, S. N.; Kovtyukh, V. V., E-mail: luck@fafnir.astr.cwru.edu, E-mail: serkor@skyline.od.ua, E-mail: val@deneb1.odessa.ua, E-mail: scan@deneb1.odessa.ua [Department of Astronomy and Astronomical Observatory, Odessa National University, Isaac Newton Institute of Chile, Odessa Branch, Shevchenko Park, 65014 Odessa (Ukraine)

    2013-07-01

    Oxygen abundances in later-type stars, and intermediate-mass stars in particular, are usually determined from the [O I] line at 630.0 nm, and to a lesser extent, from the O I triplet at 615.7 nm. The near-IR triplets at 777.4 nm and 844.6 nm are strong in these stars and generally do not suffer from severe blending with other species. However, these latter two triplets suffer from strong non-local thermodynamic equilibrium (NLTE) effects and thus see limited use in abundance analyses. In this paper, we derive oxygen abundances in a large sample of Cepheids using the near-IR triplets from an NLTE analysis, and compare those abundances to values derived from a local thermodynamic equilibrium (LTE) analysis of the [O I] 630.0 nm line and the O I 615.7 nm triplet as well as LTE abundances for the 777.4 nm triplet. All of these lines suffer from line strength problems making them sensitive to either measurement complications (weak lines) or to line saturation difficulties (strong lines). Upon this realization, the LTE results for the [O I] lines and the O I 615.7 nm triplet are in adequate agreement with the abundance from the NLTE analysis of the near-IR triplets.

  12. Cerebral oxygenation and hyperthermia

    Directory of Open Access Journals (Sweden)

    Anthony Richard Bain

    2014-03-01

    Full Text Available Hyperthermia is associated with marked reductions in cerebral blood flow (CBF. Increased distribution of cardiac output to the periphery, increases in alveolar ventilation and resultant hypocapnia each contribute to the fall in CBF during passive hyperthermia; however, their relative contribution remains a point of contention, and probably depends on the experimental condition (e.g. posture and degree of hyperthermia. The hyperthermia-induced hyperventilatory response reduces arterial CO2 pressure (PaCO2 causing cerebral vasoconstriction and subsequent reductions in flow. During supine passive hyperthermia, the majority of recent data indicate that reductions in PaCO2 may be the primary, if not sole, culprit for reduced CBF. On the other hand, during more dynamic conditions (e.g. hemorrhage or orthostatic challenges, an inability to appropriately decrease peripheral vascular conductance presents a condition whereby adequate cerebral perfusion pressure may be compromised secondary to reductions in systemic blood pressure. Although studies have reported maintenance of pre-frontal cortex oxygenation (assessed by near-infrared spectroscopy during exercise and severe heat stress, the influence of cutaneous blood flow is known to contaminate this measure. This review discusses the governing mechanisms associated with changes in CBF and oxygenation during moderate to severe (i.e. 1.0°C to 2.0°C increase in body core temperature levels of hyperthermia. Future research directions are provided.

  13. Composite oxygen transport membrane

    Science.gov (United States)

    Christie, Gervase Maxwell; Lane, Jonathan A.

    2014-08-05

    A method of producing a composite oxygen ion membrane and a composite oxygen ion membrane in which a porous fuel oxidation layer and a dense separation layer and optionally, a porous surface exchange layer are formed on a porous support from mixtures of (Ln.sub.1-xA.sub.x).sub.wCr.sub.1-yB.sub.yO.sub.3-.delta. and a doped zirconia. In the porous fuel oxidation layer and the optional porous surface exchange layer, A is Calcium and in the dense separation layer A is not Calcium and, preferably is Strontium. Preferred materials are (La.sub.0.8Ca.sub.0.2).sub.0.95Cr.sub.0.5Mn.sub.0.5O.sub.3-.delta. for the porous fuel oxidation and optional porous surface exchange layers and (La.sub.0.8Sr.sub.0.2).sub.0.95Cr.sub.0.5Fe.sub.0.5O.sub.3-.delta. for the dense separation layer. The use of such materials allows the membrane to sintered in air and without the use of pore formers to reduce membrane manufacturing costs. The use of materials, as described herein, for forming the porous layers have application for forming any type of porous structure, such as a catalyst support.

  14. Charge-carrier relaxation dynamics in highly ordered poly( p -phenylene vinylene): Effects of carrier bimolecular recombination and trapping

    Science.gov (United States)

    Soci, Cesare; Moses, Daniel; Xu, Qing-Hua; Heeger, Alan J.

    2005-12-01

    We have studied the charge-carrier relaxation dynamics in highly ordered poly( p -phenylene vinylene) over a broad time range using fast (t>100ps) transient photoconductivity measurements. The carrier density was also monitored (t>100fs) by means of photoinduced absorption probed at the infrared active vibrational modes. We find that promptly upon charge-carrier photogeneration, the initial polaron dynamics is governed by bimolecular recombination, while later in the subnanosecond time regime carrier trapping gives rise to an exponential decay of the photocurrent. The more sensitive transient photocurrent measurements indicate that in the low excitation regime, when the density of photocarriers is comparable to that of the trapping states (˜1016cm-3) , carrier hopping between traps along with transport via extended states determines the carrier relaxation, a mechanism that is manifested by a long-lived photocurrent “tail.” This photocurrent tail is reduced by lowering the temperature and/or by increasing the excitation density. Based on these data, we develop a comprehensive kinetic model that takes into account the bipolar charge transport, the free-carrier bimolecular recombination, the carrier trapping, and the carrier recombination involving free and trapped carriers.

  15. High Selectivity Oxygen Delignification

    Energy Technology Data Exchange (ETDEWEB)

    Arthur J. Ragauskas

    2005-09-30

    The overall objective of this program was to develop improved extended oxygen delignification (EOD) technologies for current U.S. pulp mill operations. This was accomplished by: (1) Identifying pulping conditions that optimize O and OO performance; (2) Identifying structural features of lignin that enhance reactivity towards EOD of high kappa pulps; (3) Identifying factors minimizing carbohydrate degradation and improve pulp strength of EOD high kappa pulps; (4) Developing a simple, reproducible method of quantifying yield gains from EOD; and (5) Developing process conditions that significantly reduce the capital requirements of EOD while optimizing the yield benefits. Key research outcomes included, demonstrating the use of a mini-O sequence such as (E+O)Dkf:0.05(E+O) or Dkf:0.05(E+O)(E+O) without interstage washing could capture approximately 60% of the delignification efficiency of a conventional O-stage without the major capital requirements associated with an O-stage for conventional SW kraft pulps. The rate of formation and loss of fiber charge during an O-stage stage can be employed to maximize net fiber charge. Optimal fiber charge development and delignification are two independent parameters and do not parallel each other. It is possible to utilize an O-stage to enhance overall cellulosic fiber charge of low and high kappa SW kraft pulps which is beneficial for physical strength properties. The application of NIR and multi-variant analysis was developed into a rapid and simple method of determining the yield of pulp from an oxygen delignification stage that has real-world mill applications. A focus point of this program was the demonstration that Kraft pulping conditions and oxygen delignification of high and low-kappa SW and HW pulps are intimately related. Improved physical pulp properties and yield can be delivered by controlling the H-factor and active alkali charge. Low AA softwood kraft pulp with a kappa number 30 has an average improvement of 2% in

  16. DYNAMIC RESPONSE ANALYSIS OF CARRIER-BASED AIRCRAFT DURING LANDING

    Institute of Scientific and Technical Information of China (English)

    段萍萍; 聂宏; 魏小辉

    2013-01-01

    In view of the complexity of landing on the deck of aircraft carrier ,a systematic model ,composed of six-degree-of-freedom mathematic model of carrier-based aircraft ,four-degree-of-freedom model of landing gears and six-degree-of-freedom mathematic model of carrier , is established in the Matlab-Simulink environment , with damping function of landing gears and dynamic characteristics of tires being considered .The model ,where the car-rier movement is introduced ,is applicable for any abnormal landing condition .Moreover ,the equations of motion and relevant parameter are also derived .The dynamic response of aircraft is calculated via the variable step-size Runge-Kuta algorithm .The effect of attitude angles of aircraft and carrier movement during the process of landing is illustrated in details .The analytical results can provide some reference for carrier-based aircraft design and main-tenance .

  17. Characteristics of participants in a gestational carrier program.

    Science.gov (United States)

    Braverman, A M; Corson, S L

    1992-08-01

    Genetic parents and gestational carriers in our gestational carrier program were evaluated by psychodiagnostic interview and by the Minnesota Multiphasic Personality Interview-2 (MMPI-2), a widely used objective psychological test, to identify psychopathology and describe personality characteristics. Overall, participants exhibited no overt psychopathology. Personality differences were found between gestational carriers and genetic mothers and genetic fathers and mothers. Clinical interviews revealed that gestational carriers tended to be the dominant partner in the relationship, were motivated by a wish to help an infertile couple, enjoyed being pregnant, showed narcissistic needs, and expressed a wish for secondary financial gain. The majority of gestational carriers stated that they had considered becoming a traditional surrogate but felt they could not surrender a child that was genetically theirs. These results indicate that there is not any predisposing psychopathology which attracts participants to the gestational carrier program.

  18. Duality of β-glucan microparticles: antigen carrier and immunostimulants

    Directory of Open Access Journals (Sweden)

    Baert K

    2016-05-01

    Full Text Available Kim Baert,1 Bruno G De Geest,2 Henri De Greve,3,4 Eric Cox,1,* Bert Devriendt1,* 1Department of Virology, Parasitology and Immunology, 2Department of Pharmaceutics, Ghent University, Merelbeke, Ghent, Belgium; 3Structural Biology Research Centre, VIB, Brussels, Belgium; 4Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium *These authors contributed equally to this work Abstract: Designing efficient recombinant mucosal vaccines against enteric diseases is still a major challenge. Mucosal delivery of recombinant vaccines requires encapsulation in potent immunostimulatory particles to induce an efficient immune response. This paper evaluates the capacity of β-glucan microparticles (GPs as antigen vehicles and characterizes their immune-stimulatory effects. The relevant infectious antigen FedF was chosen to be loaded inside the microparticles. The incorporation of FedF inside the particles was highly efficient (roughly 85% and occurred without antigen degradation. In addition, these GPs have immunostimulatory effects as well, demonstrated by the strong reactive oxygen species (ROS production by porcine neutrophils upon their recognition. Although antigen-loaded GPs still induce ROS production, antigen loading decreases this production by neutrophils for reasons yet unknown. However, these antigen-loaded GPs are still able to bind their specific β-glucan receptor, demonstrated by blocking complement receptor 3, which is the major β-glucan receptor on porcine neutrophils. The dual character of these particles is confirmed by a T-cell proliferation assay. FedF-loaded particles induce a significantly higher FedF-specific T-cell proliferation than soluble FedF. Taken together, these results show that GPs are efficient antigen carriers with immune-stimulatory properties. Keywords: β-glucan microparticles, FedF, antigen delivery vehicle, immunostimulants

  19. Fires and Burns Involving Home Medical Oxygen

    Science.gov (United States)

    ... nfpa.org Fires and Burns Involving Home Medical Oxygen The air is normally 21% oxygen. Oxygen is not flammable, but fire needs it to burn. ¾ When more oxygen is present, any fire that starts will burn ...

  20. A Silicon Micromachined Gyroscope Driven by the Rotating Carrier Self

    Institute of Scientific and Technical Information of China (English)

    Fuxue Zhang; Xu Mao; Yu Liu; Nan Zhang; Wei Zhang

    2006-01-01

    This paper reported a silicon micromachined gyroscope which is driven by the rotating carrier's angular velocity, the silicon was manufactured by anisotropy etching. The design, fabrication and packing of the sensing element were introduced in the paper. The imitation experimentation and performance test have certificated that the principle of the gyroscope is correct and the gyroscope can be used to sense yawing or pitching angular velocity of the rotating carrier, and the angular velocity of the rotating carrier itself.

  1. Carrier Statistics and Quantum Capacitance Models of Graphene Nanoscroll

    Directory of Open Access Journals (Sweden)

    M. Khaledian

    2014-01-01

    schematic perfect scroll-like Archimedes spiral. The DOS model was derived at first, while it was later applied to compute the carrier concentration and quantum capacitance model. Furthermore, the carrier concentration and quantum capacitance were modeled for both degenerate and nondegenerate regimes, along with examining the effect of structural parameters and chirality number on the density of state and carrier concentration. Latterly, the temperature effect on the quantum capacitance was studied too.

  2. Exploring Quaternized Hydroxyethylcellulose as Potential Gene Carriers

    Institute of Scientific and Technical Information of China (English)

    丁菲; 尤俊; 翁小成; 周金平; 章晓联; 周翔; 张俐娜

    2012-01-01

    Cationic polysaccharides have been receiving more attentions and used as nonviral gene delivery vectors. In this paper, quaternized hydroxyethylcellulose (QHEC) derivatives were studied as gene carriers for their efficient DNA binding abilities. All QHECs could form stable QHEC/DNA complexes and resist the degradation of DNase I. And the dynamic light scatter (DLS) results showed that all QHEC/DNA complexes could form compact particles. These QHEC/DNA complexes exhibited effective transfeetion abilities in comparison to the naked DNA. The cytotox- icities of QHEC and QHEC/DNA complexes were also evaluated in four cell lines which were relatively low com- pared with 25 kDa bPEI. All results indicated that these quaternized hydroxyethylcelluloses could be used as poten- tial gene delivery vectors.

  3. Carbon phosphide monolayers with superior carrier mobility

    Science.gov (United States)

    Wang, Gaoxue; Pandey, Ravindra; Karna, Shashi P.

    2016-04-01

    Two dimensional (2D) materials with a finite band gap and high carrier mobility are sought after materials from both fundamental and technological perspectives. In this paper, we present the results based on the particle swarm optimization method and density functional theory which predict three geometrically different phases of the carbon phosphide (CP) monolayer consisting of sp2 hybridized C atoms and sp3 hybridized P atoms in hexagonal networks. Two of the phases, referred to as α-CP and β-CP with puckered or buckled surfaces are semiconducting with highly anisotropic electronic and mechanical properties. More remarkably, they have the lightest electrons and holes among the known 2D semiconductors, yielding superior carrier mobility. The γ-CP has a distorted hexagonal network and exhibits a semi-metallic behavior with Dirac cones. These theoretical findings suggest that the binary CP monolayer is a yet unexplored 2D material holding great promise for applications in high-performance electronics and optoelectronics.Two dimensional (2D) materials with a finite band gap and high carrier mobility are sought after materials from both fundamental and technological perspectives. In this paper, we present the results based on the particle swarm optimization method and density functional theory which predict three geometrically different phases of the carbon phosphide (CP) monolayer consisting of sp2 hybridized C atoms and sp3 hybridized P atoms in hexagonal networks. Two of the phases, referred to as α-CP and β-CP with puckered or buckled surfaces are semiconducting with highly anisotropic electronic and mechanical properties. More remarkably, they have the lightest electrons and holes among the known 2D semiconductors, yielding superior carrier mobility. The γ-CP has a distorted hexagonal network and exhibits a semi-metallic behavior with Dirac cones. These theoretical findings suggest that the binary CP monolayer is a yet unexplored 2D material holding great

  4. Microemulsions as carriers for therapeutic molecules.

    Science.gov (United States)

    Mehta, Surinder K; Kaur, Gurpreet

    2010-01-01

    The thrust for finding newer drug delivery systems for exiting therapeutic molecules has opened a wide window for colloidal systems. Due to the presence of different domains of variable polarity in the microemulsion systems, they show a huge potential to be used as drug delivery vehicles for a variety of drugs. The use of microemulsion as drug delivery vehicles through a number of routes has engaged a large number of research groups in this area. Microemulsion media finds several applications ranging from drug delivery to drug nanoparticle templating due to its ability to enhance solubility, stability and bioavailability. This review on patent articles recounts the patent literature dealing with different kind of microemulsion carriers used via different routes, solubility and permeability enhancement and its use as a template for nanoparticle synthesis. PMID:19807681

  5. Hot carrier injection degradation under dynamic stress

    Institute of Scientific and Technical Information of China (English)

    Ma Xiao-Hua; Cao Yan-Rong; Hao Yue; Zhang Yue

    2011-01-01

    In this paper, we have studied hot carrier injection (HCI) under alternant stress. Under different stress modes, different degradations are obtained from the experiment results. The different alternate stresses can reduce or enhance the HC effect, which mainly depends on the latter condition of the stress cycle. In the stress mode A (DC stress with electron injection), the degradation keeps increasing. In the stress modes B (DC stress and then stress with the smallest gate injection) and C (DC stress and then stress with hole injection under Vg=0V and Vd = 1.8 V), recovery appears in the second stress period. And in the stress mode D (DC stress and then stress with hole injection under Vg = -1.8 V and Vd = 1.8 V), as the traps filled in by holes can be smaller or greater than the generated interface states, the continued degradation or recovery in different stress periods can be obtained.

  6. Blind Estimation of Multiple Carrier Frequency Offsets

    CERN Document Server

    Yu, Yuanning; Poor, H Vincent; Koivunen, Visa

    2007-01-01

    Multiple carrier-frequency offsets (CFO) arise in a distributed antenna system, where data are transmitted simultaneously from multiple antennas. In such systems the received signal contains multiple CFOs due to mismatch between the local oscillators of transmitters and receiver. This results in a time-varying rotation of the data constellation, which needs to be compensated for at the receiver before symbol recovery. This paper proposes a new approach for blind CFO estimation and symbol recovery. The received base-band signal is over-sampled, and its polyphase components are used to formulate a virtual Multiple-Input Multiple-Output (MIMO) problem. By applying blind MIMO system estimation techniques, the system response is estimated and used to subsequently transform the multiple CFOs estimation problem into many independent single CFO estimation problems. Furthermore, an initial estimate of the CFO is obtained from the phase of the MIMO system response. The Cramer-Rao Lower bound is also derived, and the la...

  7. Take advantage of your insurance carrier

    Energy Technology Data Exchange (ETDEWEB)

    Carlow, S.M.

    1990-02-01

    The primary objective of the developer of an independent energy facility is to make a profit through the sale of electricity and steam. The most effective way to achieve this objective is to design, build and operate a facility in a way that maximizes its availability and efficiency without increasing expenses. A property carrier has a range of insurance products and engineering services designed not only to transfer risk but to increase availability and efficiency and reduce the cost of operating and maintaining a facility. The independent energy producer can benefit by taking full advantage of traditional and specialty insurance products as well as engineering services that are available today. There is a whole range of insurance products that apply during the various stages of pre-construction, construction, testing and commercial operation, and these are described.

  8. Carrier Aggregation for LTE-Advanced

    DEFF Research Database (Denmark)

    Pedersen, Klaus Ingemann; Frederiksen, Frank; Rosa, Claudio;

    2011-01-01

    aggregated. This paper presents a summary of the supported CA scenarios as well as an overview of the CA functionality for LTE-Advanced with special emphasis on the basic concept, control mechanisms, and performance aspects. The discussion includes definitions of the new terms primary cell (PCell) and......Carrier aggregation (CA) is one of the key features for LTE-Advanced. By means of CA, users gain access to a total bandwidth of up to 100 MHz in order to meet the IMT-Advanced requirements. The system bandwidth may be contiguous, or composed of several non-contiguous bandwidth chunks, which are...... secondary cell (SCell), mechanisms for activation and deactivation of CCs, and the new cross-CC scheduling functionality for improved control channel optimizations. We also demonstrate how CA can be used as an enabler for simple yet effective frequency domain interference management schemes. In particular...

  9. A Systems View of the Differences between APOE ε4 Carriers and Non-carriers in Alzheimer's Disease.

    Science.gov (United States)

    Jiang, Shan; Tang, Ling; Zhao, Na; Yang, Wanling; Qiu, Yu; Chen, Hong-Zhuan

    2016-01-01

    APOE ε4 is the strongest genetic risk factor for late-onset Alzheimer's disease (AD) and accounts for 50-65% of late-onset AD. Late-onset AD patients carrying or not carrying APOE ε4 manifest many clinico-pathological distinctions. Thus, we applied a weighted gene co-expression network analysis to identify specific co-expression modules in AD based on APOE ε4 stratification. Two specific modules were identified in AD APOE ε4 carriers and one module was identified in non-carriers. The hub genes of one module of AD APOE ε4 carriers were ISOC1, ENO3, GDF10, GNB3, XPO4, ACLY and MATN2. The other module of AD APOE ε4 carriers consisted of 10 hub genes including ANO3, ARPP21, HPCA, RASD2, PCP4 and ADORA2A. The module of AD APOE ε4 non-carriers consisted of 16 hub genes including DUSP5, TNFRSF18, ZNF331, DNAJB5 and RIN1. The module of AD APOE ε4 carriers including ISOC1 and ENO3 and the module of non-carriers contained the most highly connected hub gene clusters. mRNA expression of the genes in the cluster of the ISOC1 and ENO3 module of carriers was shown to be correlated in a time-dependent manner under APOE ε4 treatment but not under APOE ε3 treatment. In contrast, mRNA expression of the genes in the cluster of non-carriers' module was correlated under APOE ε3 treatment but not under APOE ε4 treatment. The modules of carriers demonstrated genetic bases and were mainly enriched in hereditary disorders and neurological diseases, energy metabolism-associated signaling and G protein-coupled receptor-associated pathways. The module including ISOC1 and ENO3 harbored two conserved promoter motifs in its hub gene cluster that could be regulated by common transcription factors and miRNAs. The module of non-carriers was mainly enriched in neurological, immunological and cardiovascular diseases and was correlated with Parkinson's disease. These data demonstrate that AD in APOE ε4 carriers involves more genetic factors and particular biological processes, whereas AD

  10. Fertility preservation in BRCA mutation carriers.

    Science.gov (United States)

    Revelli, Alberto; Salvagno, Francesca; Delle Piane, Luisa; Casano, Simona; Evangelista, Francesca; Pittatore, Giulia; Razzano, Alessandra; Marchino, Gian L; Gennarelli, Gianluca; Benedetto, Chiara

    2016-10-01

    According to enhanced long-term survival rates of these patients, interest in fertility preservation for young women facing gonadotoxic therapies is increasing. Women who carry a mutation in the BRCA1 or BRCA2 gene have a specifically increased lifetime risk of developing breast and tubo-ovarian cancer. Moreover, they are at high risk of undergoing premature infertility due to the medical interventions that are often performed in order to reduce cancer risk or treat an already existing malignancy. Fertility issues are relevant for healthy BRCA mutation carriers, whose family-planning decisions are often influenced by the need of prophylactic bilateral salpingo-oophorectomy at young age. In BRCA mutation carriers who have a breast cancer at young age, the oncostatic treatment is associated with a significant ovarian toxicity linked to chemotherapy as well as to the long lasting hormonotherapy and to the need of delaying pregnancy for several years. Prompt counselling about different fertility preservation options should be offered to all young girls and women at high risk of ovarian insufficiency and infertility. Validated techniques to preserve fertility include oocyte and embryo cryopreservation, while experimental techniques include ovarian suppression with GnRH-analogs during chemotherapy and ovarian tissue cryopreservation. The choice of the best strategy depends on age, type of chemotherapy, partner status, cancer type, time available for fertility preservation intervention and the risk of ovarian metastasis. All available options should be offered and can be performed alone or in combination. A crucial point is to avoid a significant delay to cancer treatment. PMID:26997146

  11. Carrier-Density-Dependent Lattice Stability in InSb

    International Nuclear Information System (INIS)

    The ultrafast decay of the x-ray diffraction intensity following laser excitation of an InSb crystal has been utilized to observe carrier dependent changes in the potential energy surface. For the first time, an abrupt carrier dependent onset for potential energy surface softening and the appearance of accelerated atomic disordering for a very high average carrier density have been observed. Inertial dynamics dominate the early stages of crystal disordering for a wide range of carrier densities between the onset of crystal softening and the appearance of accelerated atomic disordering

  12. Obstacle avoidance and path planning for carrier aircraft launching

    Directory of Open Access Journals (Sweden)

    Wu Yu

    2015-06-01

    Full Text Available Launching safety and efficiency are important indexes to measure the fighting capacity of carrier. The study on path planning for taxi of carrier aircraft launching under actual deck environment is of great significance. In actual deck scheduling, manual command is applied to taxi of carrier aircraft, which has negative effects on the safety of staff and carrier aircraft launching. In consideration of both the safety and efficiency of carrier aircraft launching, the key elements of the problem are abstracted based on the analysis of deck environment, carrier aircraft maneuver performance and task requirements. According to the problem description, the mathematical model is established including various constraints. The carrier aircraft and the obstacles are reasonably simplified as circle and polygons respectively. What’s more, the proposed collision detection model reduces the calculations. Aimed at the features of model, the theory of model predictive control (MPC is applied to the path search. Then a dynamic weight heuristic function is designed and a dynamic multistep optimization algorithm is proposed. Taking the Nimitz-class aircraft carrier as an example, the paths from parking place to catapult are planned, which indicate the rationality of the model and the effectiveness of the algorithm by comparing the planning results under different simulation environments. The main contribution of research is the establishment of obstacle avoidance and path planning model. In addition, it provides the solution of model and technological foundations for comprehensive command and real-time decision-making of the carrier aircraft.

  13. Joint Iterative Carrier Synchronization and Signal Detection Employing Expectation Maximization

    DEFF Research Database (Denmark)

    Zibar, Darko; de Carvalho, Luis Henrique Hecker; Estaran Tolosa, Jose Manuel;

    2014-01-01

    In this paper, joint estimation of carrier frequency, phase, signal means and noise variance, in a maximum likelihood sense, is performed iteratively by employing expectation maximization. The parameter estimation is soft decision driven and allows joint carrier synchronization and data detection...... and nonlinear phase noise, compared to digital phase-locked loop (PLL) followed by hard decisions. Additionally, soft decision driven joint carrier synchronization and detection offers an improvement of 0.5 dB in terms of input power compared to hard decision digital PLL based carrier synchronization...

  14. Functional Oxygen Sensitivity of Astrocytes.

    Science.gov (United States)

    Angelova, Plamena R; Kasymov, Vitaliy; Christie, Isabel; Sheikhbahaei, Shahriar; Turovsky, Egor; Marina, Nephtali; Korsak, Alla; Zwicker, Jennifer; Teschemacher, Anja G; Ackland, Gareth L; Funk, Gregory D; Kasparov, Sergey; Abramov, Andrey Y; Gourine, Alexander V

    2015-07-22

    In terrestrial mammals, the oxygen storage capacity of the CNS is limited, and neuronal function is rapidly impaired if oxygen supply is interrupted even for a short period of time. However, oxygen tension monitored by the peripheral (arterial) chemoreceptors is not sensitive to regional CNS differences in partial pressure of oxygen (PO2 ) that reflect variable levels of neuronal activity or local tissue hypoxia, pointing to the necessity of a functional brain oxygen sensor. This experimental animal (rats and mice) study shows that astrocytes, the most numerous brain glial cells, are sensitive to physiological changes in PO2 . Astrocytes respond to decreases in PO2 a few millimeters of mercury below normal brain oxygenation with elevations in intracellular calcium ([Ca(2+)]i). The hypoxia sensor of astrocytes resides in the mitochondria in which oxygen is consumed. Physiological decrease in PO2 inhibits astroglial mitochondrial respiration, leading to mitochondrial depolarization, production of free radicals, lipid peroxidation, activation of phospholipase C, IP3 receptors, and release of Ca(2+) from the intracellular stores. Hypoxia-induced [Ca(2+)]i increases in astrocytes trigger fusion of vesicular compartments containing ATP. Blockade of astrocytic signaling by overexpression of ATP-degrading enzymes or targeted astrocyte-specific expression of tetanus toxin light chain (to interfere with vesicular release mechanisms) within the brainstem respiratory rhythm-generating circuits reveals the fundamental physiological role of astroglial oxygen sensitivity; in low-oxygen conditions (environmental hypoxia), this mechanism increases breathing activity even in the absence of peripheral chemoreceptor oxygen sensing. These results demonstrate that astrocytes are functionally specialized CNS oxygen sensors tuned for rapid detection of physiological changes in brain oxygenation. Significance statement: Most, if not all, animal cells possess mechanisms that allow them to

  15. Optic nerve oxygenation

    DEFF Research Database (Denmark)

    Stefánsson, Einar; Pedersen, Daniella Bach; Jensen, Peter Koch;

    2005-01-01

    at similar levels of perfusion pressure. The levels of perfusion pressure that lead to optic nerve hypoxia in the laboratory correspond remarkably well to the levels that increase the risk of glaucomatous optic nerve atrophy in human glaucoma patients. The risk for progressive optic nerve atrophy in human...... glaucoma patients is six times higher at a perfusion pressure of 30 mmHg, which corresponds to a level where the optic nerve is hypoxic in experimental animals, as compared to perfusion pressure levels above 50 mmHg where the optic nerve is normoxic. Medical intervention can affect optic nerve oxygen......-oxygenase inhibitor, indomethacin, which indicates that prostaglandin metabolism plays a role. Laboratory studies suggest that carbonic anhydrase inhibitors might be useful for medical treatment of optic nerve and retinal ischemia, potentially in diseases such as glaucoma and diabetic retinopathy. However, clinical...

  16. Bifunctional alkaline oxygen electrodes

    Science.gov (United States)

    Swette, L.; Kackley, N.; Mccatty, S. A.

    1991-01-01

    The authors describe the identification and testing of electrocatalysts and supports for the positive electrode of moderate-temperature, single-unit, rechargeable alkaline fuel cells. Recent work on Na(x)Pt3O4, a potential bifunctional catalyst, is described, as well as the application of novel approaches to the development of more efficient bifunctional electrode structures. The three dual-character electrodes considered here showed similar superior performance; the Pt/RhO2 and Rh/RhO2 electrodes showed slightly better performance than the Pt/IrO2 electrode. It is concluded that Na(x)Pt3O4 continues to be a promising bifunctional oxygen electrode catalyst but requires further investigation and development.

  17. Photosynthetic hydrogen and oxygen production by green algae

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, E.; Lee, J.W.

    1997-12-31

    An overview of photosynthetic hydrogen and oxygen production by green algae in the context of its potential as a renewable chemical feed stock and energy carrier is presented. Beginning with its discovery by Gaffron and Rubin in 1942, motivated by curiosity-driven laboratory research, studies were initiated in the early 1970s that focused on photosynthetic hydrogen production from an applied perspective. From a scientific and technical point of view, current research is focused on optimizing net thermodynamic conversion efficiencies represented by the Gibbs Free Energy of molecular hydrogen. The key research questions of maximizing hydrogen and oxygen production by light-activated water splitting in green algae are (1) removing the oxygen sensitivity of algal hydrogenases; (2) linearizing the light saturation curves of photosynthesis throughout the entire range of terrestrial solar irradiance--including the role of bicarbonate and carbon dioxide in optimization of photosynthetic electron transport and (3) the minimum number of light reactions that are required to split water to elemental hydrogen and oxygen. Each of these research topics is being actively addressed by the photobiological hydrogen research community.

  18. Saturn's Stratospheric Oxygen Compounds

    Science.gov (United States)

    Romani, Paul N.; Delgado Díaz, Héctor E.; Bjoraker, Gordon; Hesman, Brigette; Achterberg, Richard

    2016-10-01

    There are three known oxygenated species present in Saturn's upper atmosphere: H2O, CO and CO2. The ultimate source of the water must be external to Saturn as Saturn's cold tropopause effectively prevents any internal water from reaching the upper atmosphere. The carbon monoxide and dioxide source(s) could be internal, external, produced by the photochemical interaction of water with Saturn's stratospheric hydrocarbons or some combination of all of these. At this point it is not clear what the external source(s) are.Cassini's Composite InfraRed Spectrometer (CIRS) has detected emission lines of H2O and CO2 (Hesman et al., DPS 2015, 311.16 & Abbas et al. 2013, Ap. J. doi:10.1088/0004-637X/776/2/73) on Saturn. CIRS also retrieves the temperature of the stratosphere using CH4 lines at 7.7 microns. Using CIRS retrieved temperatures, the mole fraction of H2O at the 0.5-5 mbar level can be retrieved and the CO2 mole fraction at ~1-10 mbar. Coupled with ground based observations of CO (Cavalié et al., 2010, A&A, DOI: 10.1051/0004-6361/200912909) these observations provide a complete oxygen compound data set to test photochemical models.Preliminary results will be presented with an emphasis on upper limit analysis to determine the percentage of stratospheric CO and CO2 that can be produced photochemically from CIRS observational constraints on the H2O profile.

  19. Localized Charge Carrier Transport Properties of Zn1- x Ni x O/NiO Two-Phase Composites

    Science.gov (United States)

    Joshi, D. C.; Dasari, K.; Nayak, S.; Palai, R.; Suresh, P.; Thota, S.

    2016-04-01

    We report the localized charge carrier transport of two-phase composite Zn1- x Ni x O/NiO (0 ≤ x ≤ 1) using the temperature dependence of ac-resistivity ρ ac(T) across the Néel temperature T N (= 523 K) of nickel oxide. Our results provide strong evidence to the variable range hopping of charge carriers between the localized states through a mechanism involving spin-dependent activation energies. The temperature variation of carrier hopping energy ɛ h(T) and nearest-neighbor exchange-coupling parameter J ij(T) evaluated from the small poleron model exhibits a well-defined anomaly across T N. For all the composite systems, the average exchange-coupling parameter (J ij)AVG nearly equals to 70 meV which is slightly greater than the 60-meV exciton binding energy of pure zinc oxide. The magnitudes of ɛ h (˜0.17 eV) and J ij (˜11 meV) of pure NiO synthesized under oxygen-rich conditions are consistent with the previously reported theoretical estimation based on Green's function analysis. A systematic correlation between the oxygen stoichiometry and, ɛ h(T) and J ij(T) is discussed.

  20. Oxygen-reducing catalyst layer

    Science.gov (United States)

    O'Brien, Dennis P.; Schmoeckel, Alison K.; Vernstrom, George D.; Atanasoski, Radoslav; Wood, Thomas E.; Yang, Ruizhi; Easton, E. Bradley; Dahn, Jeffrey R.; O'Neill, David G.

    2011-03-22

    An oxygen-reducing catalyst layer, and a method of making the oxygen-reducing catalyst layer, where the oxygen-reducing catalyst layer includes a catalytic material film disposed on a substrate with the use of physical vapor deposition and thermal treatment. The catalytic material film includes a transition metal that is substantially free of platinum. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

  1. Trapping of the Enoyl-Acyl Carrier Protein Reductase-Acyl Carrier Protein Interaction.

    Science.gov (United States)

    Tallorin, Lorillee; Finzel, Kara; Nguyen, Quynh G; Beld, Joris; La Clair, James J; Burkart, Michael D

    2016-03-30

    An ideal target for metabolic engineering, fatty acid biosynthesis remains poorly understood on a molecular level. These carrier protein-dependent pathways require fundamental protein-protein interactions to guide reactivity and processivity, and their control has become one of the major hurdles in successfully adapting these biological machines. Our laboratory has developed methods to prepare acyl carrier proteins (ACPs) loaded with substrate mimetics and cross-linkers to visualize and trap interactions with partner enzymes, and we continue to expand the tools for studying these pathways. We now describe application of the slow-onset, tight-binding inhibitor triclosan to explore the interactions between the type II fatty acid ACP from Escherichia coli, AcpP, and its corresponding enoyl-ACP reductase, FabI. We show that the AcpP-triclosan complex demonstrates nM binding, inhibits in vitro activity, and can be used to isolate FabI in complex proteomes. PMID:26938266

  2. A Systems View of the Differences between APOE ε4 Carriers and Non-carriers in Alzheimer’s Disease

    Science.gov (United States)

    Jiang, Shan; Tang, Ling; Zhao, Na; Yang, Wanling; Qiu, Yu; Chen, Hong-Zhuan

    2016-01-01

    APOE ε4 is the strongest genetic risk factor for late-onset Alzheimer’s disease (AD) and accounts for 50–65% of late-onset AD. Late-onset AD patients carrying or not carrying APOE ε4 manifest many clinico-pathological distinctions. Thus, we applied a weighted gene co-expression network analysis to identify specific co-expression modules in AD based on APOE ε4 stratification. Two specific modules were identified in AD APOE ε4 carriers and one module was identified in non-carriers. The hub genes of one module of AD APOE ε4 carriers were ISOC1, ENO3, GDF10, GNB3, XPO4, ACLY and MATN2. The other module of AD APOE ε4 carriers consisted of 10 hub genes including ANO3, ARPP21, HPCA, RASD2, PCP4 and ADORA2A. The module of AD APOE ε4 non-carriers consisted of 16 hub genes including DUSP5, TNFRSF18, ZNF331, DNAJB5 and RIN1. The module of AD APOE ε4 carriers including ISOC1 and ENO3 and the module of non-carriers contained the most highly connected hub gene clusters. mRNA expression of the genes in the cluster of the ISOC1 and ENO3 module of carriers was shown to be correlated in a time-dependent manner under APOE ε4 treatment but not under APOE ε3 treatment. In contrast, mRNA expression of the genes in the cluster of non-carriers’ module was correlated under APOE ε3 treatment but not under APOE ε4 treatment. The modules of carriers demonstrated genetic bases and were mainly enriched in hereditary disorders and neurological diseases, energy metabolism-associated signaling and G protein-coupled receptor-associated pathways. The module including ISOC1 and ENO3 harbored two conserved promoter motifs in its hub gene cluster that could be regulated by common transcription factors and miRNAs. The module of non-carriers was mainly enriched in neurological, immunological and cardiovascular diseases and was correlated with Parkinson’s disease. These data demonstrate that AD in APOE ε4 carriers involves more genetic factors and particular biological processes

  3. CARRIER PREPARATION BUILDING MATERIALS HANDLING SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    E.F. Loros

    2000-06-28

    The Carrier Preparation Building Materials Handling System receives rail and truck shipping casks from the Carrier/Cask Transport System, and inspects and prepares the shipping casks for return to the Carrier/Cask Transport System. Carrier preparation operations for carriers/casks received at the surface repository include performing a radiation survey of the carrier and cask, removing/retracting the personnel barrier, measuring the cask temperature, removing/retracting the impact limiters, removing the cask tie-downs (if any), and installing the cask trunnions (if any). The shipping operations for carriers/casks leaving the surface repository include removing the cask trunnions (if any), installing the cask tie-downs (if any), installing the impact limiters, performing a radiation survey of the cask, and installing the personnel barrier. There are four parallel carrier/cask preparation lines installed in the Carrier Preparation Building with two preparation bays in each line, each of which can accommodate carrier/cask shipping and receiving. The lines are operated concurrently to handle the waste shipping throughputs and to allow system maintenance operations. One remotely operated overhead bridge crane and one remotely operated manipulator is provided for each pair of carrier/cask preparation lines servicing four preparation bays. Remotely operated support equipment includes a manipulator and tooling and fixtures for removing and installing personnel barriers, impact limiters, cask trunnions, and cask tie-downs. Remote handling equipment is designed to facilitate maintenance, dose reduction, and replacement of interchangeable components where appropriate. Semi-automatic, manual, and backup control methods support normal, abnormal, and recovery operations. Laydown areas and equipment are included as required for transportation system components (e.g., personnel barriers and impact limiters), fixtures, and tooling to support abnormal and recovery operations. The

  4. Oxygen diffusion and oxygen effect in tumor tissue

    International Nuclear Information System (INIS)

    The diffusion of oxygen in tumor cords of bronchus carcinoma of the lung have been studied with refined computer methods for solving the diffusion equation in axis symmetric tumor structures. In this tumor configuration we may find three different regions consisting of euoxic cells, hypoxic tumor cells and necrotic parts. In the case of oxygen supply from a capillary inside a cylinder of tumor tissue with radius 200 μm or in a tumor cord of radius 300 μm with oxygen supply by capillaries outside, we get a relation of well oxygenated cells to hypoxic cells approximately as 1:8 or as 1:1.1 respectively. Of course most of the tumor cords observed in histological slices have smaller diameters, so that an average of approximately 20% hypoxic cells can be assumed. Based on the work of Ardenne, the diffusion of oxygen and glucose in a tumor of type DS-carcinosarcom has been investigated in both intact tumor and tumor treated with ionizing radiation. We can show that a strong reoxygenation effect takes place in that the well supplied regions may increase in some tumor configurations up to a factor of four by volume. The biological consequences of the oxygen pressure determined in tumor cells are discussed in detail. The investigation of oxygen diffusion in the intercapillary tumor region should give a quantitative physical basis for considering the oxygen effect with the aim to explain the advantages of neutron therapy against conventional radiotherapy. (orig./MG)

  5. Carrier-carrier and carrier-phonon scattering in the low-density and low-temperature regime for resonantly pumped semiconductor quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Lorke, M.; Jahnke, F. [Institute for Theoretical Physics, University of Bremen (Germany); Gartner, P. [Institute for Theoretical Physics, University of Bremen (Germany); National Institute for Materials Physics, POB MG-7, Bucharest-Magurele (Romania); Seebeck, J.

    2009-02-15

    We study carrier relaxation due to Coulomb scattering and interaction with LO-phonons in semiconductor quantum dots at low temperatures. Scattering for different relaxation process are evaluated for various carrier distributions that correspond to stages of the typical relaxation kinetics after optical excitation with a weak pulse, generating on average less than one electron per quantum dot. Even when the spacing of the quantum dot energy levels does not match the LO-phonon energy, we.nd that carrier-LO-phonon scattering, in addition to electronelectron and electron-hole interaction, provides efficient carrier relaxation. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. 14 CFR 255.5 - Contracts with participating carriers.

    Science.gov (United States)

    2010-01-01

    ... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS AIRLINE COMPUTER RESERVATIONS SYSTEMS § 255.5 Contracts with participating carriers. (a) No system may require a carrier to maintain any particular level of participation or buy any enhancements in its system on the basis of participation levels or enhancements selected...

  7. 27 CFR 26.117 - Action by carrier.

    Science.gov (United States)

    2010-04-01

    ... OF THE TREASURY LIQUORS LIQUORS AND ARTICLES FROM PUERTO RICO AND THE VIRGIN ISLANDS Taxpayment of Liquors and Articles in Puerto Rico Procedure at Port of Arrival § 26.117 Action by carrier. The carrier of the merchandise specified on the Form 487B shall, at the time of unlading at the port of...

  8. Heat to electricity conversion by cold carrier emissive energy harvesters

    International Nuclear Information System (INIS)

    This paper suggests a method to convert heat to electricity by the use of devices called cold carrier emissive energy harvesters (cold carrier EEHs). The working principle of such converters is explained and theoretical power densities and efficiencies are calculated for ideal devices. Cold carrier EEHs are based on the same device structure as hot carrier solar cells, but works in an opposite way. Whereas a hot carrier solar cell receives net radiation from the sun and converts some of this radiative heat flow into electricity, a cold carrier EEH sustains a net outflux of radiation to the surroundings while converting some of the energy supplied to it into electricity. It is shown that the most basic type of cold carrier EEHs have the same theoretical efficiency as the ideal emissive energy harvesters described earlier by Byrnes et al. In the present work, it is also shown that if the emission from the cold carrier EEH originates from electron transitions across an energy gap where a difference in the chemical potential of the electrons above and below the energy gap is sustained, power densities slightly higher than those given by Byrnes et al. can be achieved

  9. Characterization of the "Escherichia Coli" Acyl Carrier Protein Phosphodiesterase

    Science.gov (United States)

    Thomas, Jacob

    2009-01-01

    Acyl carrier protein (ACP) is a small essential protein that functions as a carrier of the acyl intermediates of fatty acid synthesis. ACP requires the posttranslational attachment of a 4'phosphopantetheine functional group, derived from CoA, in order to perform its metabolic function. A Mn[superscript 2+] dependent enzymatic activity that removes…

  10. Tracking Ultrafast Carrier Dynamics in Single Semiconductor Nanowire Heterostructures

    Directory of Open Access Journals (Sweden)

    Taylor A.J.

    2013-03-01

    Full Text Available An understanding of non-equilibrium carrier dynamics in silicon (Si nanowires (NWs and NW heterostructures is very important due to their many nanophotonic and nanoelectronics applications. Here, we describe the first measurements of ultrafast carrier dynamics and diffusion in single heterostructured Si nanowires, obtained using ultrafast optical microscopy. By isolating individual nanowires, we avoid complications resulting from the broad size and alignment distribution in nanowire ensembles, allowing us to directly probe ultrafast carrier dynamics in these quasi-one-dimensional systems. Spatially-resolved pump-probe spectroscopy demonstrates the influence of surface-mediated mechanisms on carrier dynamics in a single NW, while polarization-resolved femtosecond pump-probe spectroscopy reveals a clear anisotropy in carrier lifetimes measured parallel and perpendicular to the NW axis, due to density-dependent Auger recombination. Furthermore, separating the pump and probe spots along the NW axis enabled us to track space and time dependent carrier diffusion in radial and axial NW heterostructures. These results enable us to reveal the influence of radial and axial interfaces on carrier dynamics and charge transport in these quasi-one-dimensional nanosystems, which can then be used to tailor carrier relaxation in a single nanowire heterostructure for a given application.

  11. Quality of service modeling and analysis for carrier ethernet

    NARCIS (Netherlands)

    Malhotra, R.

    2008-01-01

    Today, Ethernet is moving into the mainstream evolving into a carrier grade technology. Termed as Carrier Ethernet it is expected to overcome most of the shortcomings of native Ethernet. It is envisioned to carry services end-to-end serving corporate data networking and broadband access demands as w

  12. Carriers of foot-and-mouth disease virus: a review

    NARCIS (Netherlands)

    Moonen, P.; Schrijver, R.

    2000-01-01

    This review describes current knowledge about persistent foot-and-mouth disease virus (FMDV) infections, the available methods to detect carrier animals, the properties of persisting virus, the immunological mechanisms, and the risk of transmission. In particular, knowledge about the carrier state,

  13. Modeling of carrier dynamics in quantum-well electroabsorption modulators

    DEFF Research Database (Denmark)

    Højfeldt, Sune; Mørk, Jesper

    2002-01-01

    various design parameters have on the device properties, in particular how they affect the carrier dynamics and the corresponding field dynamics. A number of different types of results are presented. We calculate absorption spectra and steady-state field screening due to carrier pile-up at the separate...

  14. Cardiac involvement in carriers of Duchenne and Becker muscular dystrophy

    NARCIS (Netherlands)

    Hoogerwaard, EM; van der Wouw, PA; Wilde, AAM; Bakker, E; Ippel, PF; Oosterwijk, JC; Majoor-Krakauer, DF; van Essen, AJ; Leschot, NJ; de Visser, M

    1999-01-01

    A cross-sectional study in a cohort of DNA proven carriers of Duchenne (DMD) and Becker (BMD) muscular dystrophy was undertaken with the following objectives: (1) to estimate the frequency of electrocardiographic (ECG) and echocardiographic abnormalities; (2) to establish the proportion of carriers

  15. Spread Spectrum Modulation by Using Asymmetric-Carrier Random PWM

    DEFF Research Database (Denmark)

    Mathe, Laszlo; Lungeanu, Florin; Sera, Dezso;

    2012-01-01

    This paper presents a new fixed carrier frequency random PWM method, where a new type of carrier wave is proposed for modulation. Based on simulations and experimental measurements, it is shown that the spread effect of the discrete components from the motor current spectra and acoustic spectra...

  16. Heat to electricity conversion by cold carrier emissive energy harvesters

    Energy Technology Data Exchange (ETDEWEB)

    Strandberg, Rune [Department of Engineering Sciences, University of Agder, Jon Lilletuns vei 9, 4879 Grimstad (Norway)

    2015-12-07

    This paper suggests a method to convert heat to electricity by the use of devices called cold carrier emissive energy harvesters (cold carrier EEHs). The working principle of such converters is explained and theoretical power densities and efficiencies are calculated for ideal devices. Cold carrier EEHs are based on the same device structure as hot carrier solar cells, but works in an opposite way. Whereas a hot carrier solar cell receives net radiation from the sun and converts some of this radiative heat flow into electricity, a cold carrier EEH sustains a net outflux of radiation to the surroundings while converting some of the energy supplied to it into electricity. It is shown that the most basic type of cold carrier EEHs have the same theoretical efficiency as the ideal emissive energy harvesters described earlier by Byrnes et al. In the present work, it is also shown that if the emission from the cold carrier EEH originates from electron transitions across an energy gap where a difference in the chemical potential of the electrons above and below the energy gap is sustained, power densities slightly higher than those given by Byrnes et al. can be achieved.

  17. 5 CFR 890.505 - Recurring premium payments to carriers.

    Science.gov (United States)

    2010-01-01

    ... § 890.505 Recurring premium payments to carriers. The procedures for payment of premiums, contingency reserve, and interest distribution to FEHB Program carriers shall be those contained in 48 CFR subpart... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Recurring premium payments to...

  18. AQUASOMES: A NOVEL CARRIER FOR DRUG DELIVERY

    Directory of Open Access Journals (Sweden)

    Vishal Sutariya

    2012-03-01

    Full Text Available Nanobiopharmaceutics involves delivery of biopharmaceutical product through different biomaterials like multifunctional nanoparticles, quantum dots, aquasomes, superparamagnetic iron oxide crystals, and liposomes dendrimers. Nanotechnology has emerged fields of biomedical research in the last few decades the presents context is an attempt to present the brief information about nanobiotechnological applications. Aquasomes are nanoparticulate carrier system but instead of being simple nanoparticles these arse three layered self assembled structures, comprised of a solid phase nanocrystalline core coated with oligomeric film to which biochemically active molecules are adsorbed with or without modification. Aquasomes are spherical 60–300 nm particles used for drug and antigen delivery. Aquasomes discovery comprises a principle from microbiology, food chemistry, biophysics and many discoveries including solid phase synthesis, supramolecular chemistry, molecular shape change and self assembly. Three types of core materials are mainly used for producing aquasomes: tin oxide, nanocrystalline carbon ceramics (diamonds and brushite (calcium phosphate dihydrate. Calcium phosphate is the core of interest, owing to its natural presence in the body. The brushite is unstable and converts to hydroxyapatite upon prolong storage. Hydroxyapatite seems, therefore, a better core for the preparation of aquasomes. It is widely used for the preparation of implants for drug delivery. The solid core provides the structural stability, while the carbohydrate coating protects against dehydration and stabilizes the biochemically active molecules. This property of maintaining the conformational integrity of bioactive molecules has led to the proposal that aquasomes have potential as a carrier system for delivery of peptide, protein, hormones, antigens and genes to specific sites. Aquasome deliver their content through specific targeting, molecular sheiling and slow

  19. Subsurface Imaging and Sensing of Charge Carrier Movements in the Earth’s Crust

    Science.gov (United States)

    Dahlgren, R.; Freund, F. T.; Lazarus, M.; Wang, J. S.; Rekenthaler, D.; Peters, R. D.; Duma, G.

    2009-12-01

    The DUSEL facility will enable unique opportunities for field experiments that would otherwise not be possible at surface facilities (Lesko, K.T., TAUP, 2007) and support a host of undergraduate and graduate educational projects. In this presentation, some of the proposed geophysics experiments will be described as part of the subsurface Imaging and Sensing (SIS) project to study charge carrier movement in crustal rock as a function of various perturbations. The electric conductivity of the Earth’s crust is dominated by positive hole charge carriers, e.g. mobile electron vacancy defects (EVD) in the oxygen anion sublattice of minerals that make up the bulk of crustal rocks. We are interested in (i) coupling of fundamental processes linked to the activation of additional EVDs in rocks deep in the crust subjected to tectonic stresses and the outflow of these charge carriers into the surrounding rocks, (ii) their manifestation across the electromagnetic spectrum and other measuands, (iii) induced forces that arise when these charge carriers are subjected to the episodic or daily magnetic field variations coming from geomagnetic storms or from the ionospheric current vortex, and (iv) in the movement of positive holes in the shallow crust when a thunderstorm system drifts overhead, dragging along a charge cloud in the ground. We propose to conduct active rock stressing experiments in situ using expanding grout technique (performing electrical, electromagnetic, and VolksMeter tilt measurements) and to monitor the electric and magnetic field variations penetrating into the Earth’s crust. Additionally optical phenomena will be investigated (anomalous infrared signatures, visible light arising from atomic oxygen and corona discharge, and infrared imaging). If budget permits, measurement of changes of acoustic velocity, evolution of chemical species (H2, O*, Rn, etc) and radar reflectivity as a function of stresses will also be attempted. We propose to study the charge

  20. Charge carrier coherence and Hall effect in organic semiconductors

    Science.gov (United States)

    Yi, H. T.; Gartstein, Y. N.; Podzorov, V.

    2016-03-01

    Hall effect measurements are important for elucidating the fundamental charge transport mechanisms and intrinsic mobility in organic semiconductors. However, Hall effect studies frequently reveal an unconventional behavior that cannot be readily explained with the simple band-semiconductor Hall effect model. Here, we develop an analytical model of Hall effect in organic field-effect transistors in a regime of coexisting band and hopping carriers. The model, which is supported by the experiments, is based on a partial Hall voltage compensation effect, occurring because hopping carriers respond to the transverse Hall electric field and drift in the direction opposite to the Lorentz force acting on band carriers. We show that this can lead in particular to an underdeveloped Hall effect observed in organic semiconductors with substantial off-diagonal thermal disorder. Our model captures the main features of Hall effect in a variety of organic semiconductors and provides an analytical description of Hall mobility, carrier density and carrier coherence factor.

  1. Imaging ballistic carrier trajectories in graphene using scanning gate microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Morikawa, Sei; Masubuchi, Satoru [Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan); Dou, Ziwei; Wang, Shu-Wei; Smith, Charles G.; Connolly, Malcolm R., E-mail: mrc61@cam.ac.uk [Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE (United Kingdom); Watanabe, Kenji; Taniguchi, Takashi [National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Machida, Tomoki, E-mail: tmachida@iis.u-tokyo.ac.jp [Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan); Institute for Nano Quantum Information Electronics, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan)

    2015-12-14

    We use scanning gate microscopy to map out the trajectories of ballistic carriers in high-mobility graphene encapsulated by hexagonal boron nitride and subject to a weak magnetic field. We employ a magnetic focusing geometry to image carriers that emerge ballistically from an injector, follow a cyclotron path due to the Lorentz force from an applied magnetic field, and land on an adjacent collector probe. The local electric field generated by the scanning tip in the vicinity of the carriers deflects their trajectories, modifying the proportion of carriers focused into the collector. By measuring the voltage at the collector while scanning the tip, we are able to obtain images with arcs that are consistent with the expected cyclotron motion. We also demonstrate that the tip can be used to redirect misaligned carriers back to the collector.

  2. Experimental and ab initio ultrafast carrier dynamics in plasmonic nanoparticles

    CERN Document Server

    Brown, Ana M; Narang, Prineha; Schwartzberg, Adam M; Goddard, William A; Atwater, Harry A

    2016-01-01

    Ultrafast pump-probe measurements of plasmonic nanostructures probe the non-equilibrium behavior of excited carriers, which involves several competing effects obscured in typical empirical analyses. Here we present pump-probe measurements of plasmonic nanoparticles along with a complete theoretical description based on first-principles calculations of carrier dynamics and optical response, free of any fitting parameters. We account for detailed electronic-structure effects in the density of states, excited carrier distributions, electron-phonon coupling, and dielectric functions which allow us to avoid effective electron temperature approximations. Using this calculation method, we obtain excellent quantitative agreement with spectral and temporal features in transient-absorption measurements. In both our experiments and calculations, we identify the two major contributions of the initial response with distinct signatures: short-lived highly non-thermal excited carriers and longer-lived thermalizing carriers.

  3. Bombarding Cancer: Biolistic Delivery of therapeutics using Porous Si Carriers

    Science.gov (United States)

    Zilony, Neta; Tzur-Balter, Adi; Segal, Ester; Shefi, Orit

    2013-08-01

    A new paradigm for an effective delivery of therapeutics into cancer cells is presented. Degradable porous silicon carriers, which are tailored to carry and release a model anti-cancer drug, are biolistically bombarded into in-vitro cancerous targets. We demonstrate the ability to launch these highly porous microparticles by a pneumatic capillary gene gun, which is conventionally used to deliver cargos by heavy metal carriers. By optimizing the gun parameters e.g., the accelerating gas pressure, we have successfully delivered the porous carriers, to reach deep targets and to cross a skin barrier in a highly spatial resolution. Our study reveals significant cytotoxicity towards the target human breast carcinoma cells following the delivery of drug-loaded carriers, while administrating empty particles results in no effect on cell viability. The unique combination of biolistics with the temporal control of payload release from porous carriers presents a powerful and non-conventional platform for designing new therapeutic strategies.

  4. Nonequilibrium carrier dynamics in transition metal dichalcogenide semiconductors

    Science.gov (United States)

    Steinhoff, A.; Florian, M.; Rösner, M.; Lorke, M.; Wehling, T. O.; Gies, C.; Jahnke, F.

    2016-09-01

    When exploring new materials for their potential in (opto)electronic device applications, it is important to understand the role of various carrier interaction and scattering processes. In atomically thin transition metal dichalcogenide semiconductors, the Coulomb interaction is known to be much stronger than in quantum wells of conventional semiconductors like GaAs, as witnessed by the 50 times larger exciton binding energy. The question arises, whether this directly translates into equivalently faster carrier-carrier Coulomb scattering of excited carriers. Here we show that a combination of ab initio band-structure and many-body theory predicts Coulomb-mediated carrier relaxation on a sub-100 fs time scale for a wide range of excitation densities, which is less than an order of magnitude faster than in quantum wells.

  5. Carrier-dependent temporal processing in an auditory interneuron.

    Science.gov (United States)

    Sabourin, Patrick; Gottlieb, Heather; Pollack, Gerald S

    2008-05-01

    Signal processing in the auditory interneuron Omega Neuron 1 (ON1) of the cricket Teleogryllus oceanicus was compared at high- and low-carrier frequencies in three different experimental paradigms. First, integration time, which corresponds to the time it takes for a neuron to reach threshold when stimulated at the minimum effective intensity, was found to be significantly shorter at high-carrier frequency than at low-carrier frequency. Second, phase locking to sinusoidally amplitude modulated signals was more efficient at high frequency, especially at high modulation rates and low modulation depths. Finally, we examined the efficiency with which ON1 detects gaps in a constant tone. As reflected by the decrease in firing rate in the vicinity of the gap, ON1 is better at detecting gaps at low-carrier frequency. Following a gap, firing rate increases beyond the pre-gap level. This "rebound" phenomenon is similar for low- and high-carrier frequencies.

  6. Oxygen Effects in Anaerobic Digestion

    Directory of Open Access Journals (Sweden)

    Deshai Botheju

    2009-10-01

    Full Text Available Interaction of free oxygen in bio-gasification is a sparsely studied area, apart from the common argument of oxygen being toxic and inhibitory for anaerobic micro-cultures. Some studies have, however, revealed increased solubilisation of organic matter in the presence of some free oxygen in anaerobic digestion. This article analyses these counterbalancing phenomena with a mathematical modelling approach using the widely accepted biochemical model ADM 1. Aerobic oxidation of soluble carbon and inhibition of obligatory anaerobic organisms are modelled using standard saturation type kinetics. Biomass dependent first order hydrolysis kinetics is used to relate the increased hydrolysis rate with oxygen induced increase in biomass growth. The amended model, ADM 1-Ox (oxygen, has 25 state variables and 22 biochemical processes, presented in matrix form. The computer aided simulation tool AQUASIM 2.1 is used to simulate the developed model. Simulation predictions are evaluated against experimental data obtained using a laboratory batch test array comprising miniature anaerobic bio-reactors of 100 ml total volume each, operated under different initial air headspaces giving rise to the different oxygen loading conditions. The reactors were initially fed with a glucose solution and incubated at 35 Celsius, for 563 hours. Under the oxygen load conditions of 22, 44 and 88 mg/L, the ADM1-Ox model simulations predicted the experimental methane potentials quite adequately. Both the experimental data and the simulations suggest a linear reduction of methane potential with respect to the increase in oxygen load within this range.

  7. Mars oxygen production system design

    Science.gov (United States)

    Cotton, Charles E.; Pillow, Linda K.; Perkinson, Robert C.; Brownlie, R. P.; Chwalowski, P.; Carmona, M. F.; Coopersmith, J. P.; Goff, J. C.; Harvey, L. L.; Kovacs, L. A.

    1989-01-01

    The design and construction phase is summarized of the Mars oxygen demonstration project. The basic hardware required to produce oxygen from simulated Mars atmosphere was assembled and tested. Some design problems still remain with the sample collection and storage system. In addition, design and development of computer compatible data acquisition and control instrumentation is ongoing.

  8. Long-Lived Hot Carriers in III-V Nanowires.

    Science.gov (United States)

    Tedeschi, D; De Luca, M; Fonseka, H A; Gao, Q; Mura, F; Tan, H H; Rubini, S; Martelli, F; Jagadish, C; Capizzi, M; Polimeni, A

    2016-05-11

    Heat management mechanisms play a pivotal role in driving the design of nanowire (NW)-based devices. In particular, the rate at which charge carriers cool down after an external excitation is crucial for the efficiency of solar cells, lasers, and high-speed transistors. Here, we investigate the thermalization properties of photogenerated carriers by continuous-wave (cw) photoluminescence (PL) in InP and GaAs NWs. A quantitative analysis of the PL spectra recorded up to 310 K shows that carriers can thermalize at a temperature much higher than that of the lattice. We find that the mismatch between carrier and lattice temperature, ΔT, increases exponentially with lattice temperature and depends inversely on the NW diameter. ΔT is instead independent of other NW characteristics, such as crystal structure (wurtzite vs zincblende), chemical composition (InP vs GaAs), shape (tapered vs columnar NWs), and growth method (vapor-liquid-solid vs selective-area growth). Remarkably, carrier temperatures as high as 500 K are reached at the lattice temperature of 310 K in NWs with ∼70 nm diameter. While a population of nonequilibrium carriers, usually referred to as "hot carriers", is routinely generated by high-power laser pulses and detected by ultrafast spectroscopy, it is quite remarkable that it can be observed in cw PL measurements, when a steady-state population of carriers is established. Time-resolved PL measurements show that even in the thinnest NWs carriers have enough time (∼1 ns) after photoexcitation to interact with phonons and thus to release their excess energy. Nevertheless, the inability of carriers to reach a full thermal equilibrium with the lattice points to inhibited phonon emission primarily caused by the large surface-to-volume ratio of small diameter NWs. PMID:27104870

  9. The Oxygen a Band

    Science.gov (United States)

    Benner, D. Chris; Devi, V. Malathy; Hoo, Jiajun; Hodges, Joseph; Long, David A.; Sung, Keeyoon; Drouin, Brian; Okumura, Mitchio; Bui, Thinh Quoc; Rupasinghe, Priyanka

    2014-06-01

    The oxygen A band is used for numerous atmospheric experiments, but spectral line parameters that sufficiently describe the spectrum to the level required by OCO2 and other high precision/accuracy experiments are lacking. Fourier transform spectra from the Jet Propulsion Laboratory and cavity ring down spectra from the National Institute of Standards and Technology were fitted simultaneously using the William and Mary multispectrum nonlinear least squares fitting technique into a single solution including the entire band. In addition, photoacoustic spectra already available from the California Institute of Technology will be added to the solution. The three types of spectrometers are complementary allowing the strengths of each to fill in the weaknesses of the others. With this technique line positions, intensities, widths, shifts, line mixing, Dicke narrowing, temperature dependences and collision induced absorption have been obtained in a single physically consistent fit. D. Chris Benner, C. P. Rinsland, V. M. Devi, M. A. H. Smith, and D. Atkins, JQSRT 1995;53:705-21. Part of the research described in this paper was performed at The College of William and Mary, the, Jet Propulsion Laboratory, California Institute of Technology, under contracts and cooperative agreements with the National Aeronautics and Space Administration and the Jet Propulsion Laboratory. Support for the National Institute of Standards and Technology was provided by the NIST Greenhouse Gas Measurements and Climate Research Program and a NIST Innovations in Measurement Science (IMS) award.

  10. Electromigration of carrier-free radionuclides. 13

    International Nuclear Information System (INIS)

    Using a special type of on line electromigration measurements of γ-emitting radionuclides in homogeneous aqueous electrolytes free of supporting materials the electromigration behaviour of the carrier-free 241Am-Am(III) in inert electrolytes, μ = 0.1 (ClO4-), T = 298.1(1) K, was studied. Basing on experimental dependencies of the overall ion mobilities of 241Am-Am(III) on pH between pH 5.5 and 12.9 the stoichiometric hydrolysis constants pβ3 = 28.8(9) and pK1 = 6.9(2) were obtained. For K4 a limitation of pK4 > 13.9(3) was possible, because no formation of anionic hydrolysis products in solutions pH 241Am-Am(III) degrees in the range pH 5.5 - 3 from +6.85(15) up to +5.50(15) · 10-4 cm2s-1V-1. Dependencies of this effect on overall ionic strength, inert electrolyte anion, and temperature of the electrolytes were studied in detail both in acidic and neutral solutions. (author)

  11. European retrievable carrier Eureca servicing by Hermes

    Science.gov (United States)

    Kerstein, L.; Dettmer, J.; Rath, W.

    1987-09-01

    It has been demonstrated that HERMES with a cargo bay configuration as depicted in figure 1 (5 m length, 3 m diam.) with Handling and Positioning Aid (HPA) and HERMES Robotic Arm (HERA) is capable to service a small platform like EURECA, which is an NSTS quarter payload. Only 1/3 of the HERMES cargo bay volume and payload mass is required for the accommodation of the payload Orbital Replaceable Units. By implementing two additional hydrazine tanks refuelling can be avoided for a two-years EURECA mission. The overall servicing configuration is described as follows: The European Retrievable Carrier EURECA-B is mechanically attached through its -y-side sill trunnion to the HERMES berthing port. The HERMES cargo bay doors with radiators are opened and oriented to earth. The HERMES Robotic Arm is equipped with a Module Service Tool (MST) ready for Orbital Replaceable Unit (ORU) exchange. The HERMES berthing port is located at the rear side of the cargo bay in order to achieve best visibility, clearance and accessibility of the HERMES Robotic Arm operation within the cargo bay and the EURECA payload area. The EURECA solar arrays and antennas remain deployed. During the servicing operation, power will be provided by the fully deployed solar arrays. In order to minimize the plume impingement effect, the solar array edge is directed to the HERMES wing.

  12. POLYURETHANE COMPOSITES AS DRUG CARRIERS:: RELEASE PATTERNS

    Directory of Open Access Journals (Sweden)

    M. V. Grigoreva

    2013-10-01

    Full Text Available Biodegradable polyurethanes attract interest of those developing composite materials for biomedical applications. One of their features is their ability to serve as carriers, or matrixes, for medicines and other bioactive compounds to produce a therapeutic effect in body through targeted and/or prolonged delivery of these compounds in the process of their controlled release from matrix. The review presents polyurethane composites as matrices for a number of drugs. The relation between structure of the composites and their degradability both in vitro and in vivo and the dependence of drug release kinetics on physicochemical properties of polyurethane matrix are highlighted. The release of drugs (cefazolin, naltrexone and piroxicam from the composites based on cross-linked polyurethanes (synthesized from laprols, Mw between 1,500 and 2,000 Da and toluylene diisocyanate demonstrated more or less the same pattern (about 10 days in vitro and three to five days in vivo. In contrast, the composites with dioxydine based on a linear polyurethanes (synthesized from oligotetramethilene glycol, Mw 1,000 Da, diphenylmethane-4,4’-diisocyanate and 1,4-butanediol retained their antimicrobial activity at least 30 days. They also showed a significantly higher breaking strength as compared to that of the composites based on cross-linked polyurethanes.

  13. Analysis of thermoelectric properties of amorphous InGaZnO thin film by controlling carrier concentration

    Directory of Open Access Journals (Sweden)

    Yuta Fujimoto

    2015-09-01

    Full Text Available We have investigated the thermoelectric properties of amorphous InGaZnO (a-IGZO thin films optimized by adjusting the carrier concentration. The a-IGZO films were produced under various oxygen flow ratios. The Seebeck coefficient and the electrical conductivity were measured from 100 to 400 K. We found that the power factor (PF at 300 K had a maximum value of 82 × 10−6 W/mK2, where the carrier density was 7.7 × 1019 cm−3. Moreover, the obtained data was analyzed by fitting the percolation model. Theoretical analysis revealed that the Fermi level was located approximately above the potential barrier when the PF became maximal. The thermoelectric properties were controlled by the relationship between the position of Fermi level and the height of potential energy barriers.

  14. Oxygen detection using evanescent fields

    Science.gov (United States)

    Duan, Yixiang; Cao, Weenqing

    2007-08-28

    An apparatus and method for the detection of oxygen using optical fiber based evanescent light absorption. Methylene blue was immobilized using a sol-gel process on a portion of the exterior surface of an optical fiber for which the cladding has been removed, thereby forming an optical oxygen sensor. When light is directed through the optical fiber, transmitted light intensity varies as a result of changes in the absorption of evanescent light by the methylene blue in response to the oxygen concentration to which the sensor is exposed. The sensor was found to have a linear response to oxygen concentration on a semi-logarithmic scale within the oxygen concentration range between 0.6% and 20.9%, a response time and a recovery time of about 3 s, ant to exhibit good reversibility and repeatability. An increase in temperature from 21.degree. C. to 35.degree. C. does not affect the net absorption of the sensor.

  15. Efficient carrier relaxation and fast carrier recombination of N-polar InGaN/GaN light emitting diodes

    International Nuclear Information System (INIS)

    Based on quantum efficiency and time-resolved electroluminescence measurements, the effects of carrier localization and quantum-confined Stark effect (QCSE) on carrier transport and recombination dynamics of Ga- and N-polar InGaN/GaN light-emitting diodes (LEDs) are reported. The N-polar LED exhibits shorter ns-scale response, rising, delay, and recombination times than the Ga-polar one does. Stronger carrier localization and the combined effects of suppressed QCSE and electric field and lower potential barrier acting upon the forward bias in an N-polar LED provide the advantages of more efficient carrier relaxation and faster carrier recombination. By optimizing growth conditions to enhance the radiative recombination, the advantages of more efficient carrier relaxation and faster carrier recombination in a competitive performance N-polar LED can be realized for applications of high-speed flash LEDs. The research results provide important information for carrier transport and recombination dynamics of an N-polar InGaN/GaN LED

  16. Multi-carrier Equalization by Restoration of RedundancY (MERRY) for Adaptive Channel Shortening in Multi-carrier Systems

    OpenAIRE

    Samir Abd Elghafar; Salaheldin M. Diab; Sallam, Bassiouny M.; Moawad I. Dessouky; El-Sayed M. El-Rabaie; Fathi E. Abd El-Samie

    2013-01-01

    This paper proposes a new blind adaptive channel shortening approach for multi-carrier systems. Theperformance of the discrete Fourier transform-DMT (DFT-DMT) system is investigated with the proposedDST-DMT system over the standard carrier serving area (CSA) loop1. Enhanced bit rates demonstratedand less complexity also involved by the simulationof the DST-DMT system.

  17. Efficient carrier relaxation and fast carrier recombination of N-polar InGaN/GaN light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Shih-Wei, E-mail: swfeng@nuk.edu.tw; Liao, Po-Hsun [Department of Applied Physics, National University of Kaohsiung, No. 700, Kaohsiung University Rd., Nan Tzu Dist., 811 Kaohsiung, Taiwan (China); Leung, Benjamin; Han, Jung [Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520 (United States); Yang, Fann-Wei [Department of Electronic Engineering, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Wang, Hsiang-Chen [Graduate Institute of Opto-Mechatronics and Advanced Institute of Manufacturing with High-Tech Innovations (AIM-HI), National Chung Cheng University, Chia-Yi, Taiwan (China)

    2015-07-28

    Based on quantum efficiency and time-resolved electroluminescence measurements, the effects of carrier localization and quantum-confined Stark effect (QCSE) on carrier transport and recombination dynamics of Ga- and N-polar InGaN/GaN light-emitting diodes (LEDs) are reported. The N-polar LED exhibits shorter ns-scale response, rising, delay, and recombination times than the Ga-polar one does. Stronger carrier localization and the combined effects of suppressed QCSE and electric field and lower potential barrier acting upon the forward bias in an N-polar LED provide the advantages of more efficient carrier relaxation and faster carrier recombination. By optimizing growth conditions to enhance the radiative recombination, the advantages of more efficient carrier relaxation and faster carrier recombination in a competitive performance N-polar LED can be realized for applications of high-speed flash LEDs. The research results provide important information for carrier transport and recombination dynamics of an N-polar InGaN/GaN LED.

  18. Oxygen variability and meridional oxygen supply in the tropical North East Atlantic oxygen minimum zone

    Science.gov (United States)

    Hahn, Johannes; Brandt, Peter; Greatbatch, Richard J.; Krahmann, Gerd; Körtzinger, Arne

    2013-04-01

    The oxygen minimum zone (OMZ) of the tropical North East Atlantic (TNEA) is located between the oxygen-rich equatorial region and the Cape Verde Frontal Zone at about 20°N in a depth range of 300 - 700 m. Its horizontal extent is predominantly defined by the North Equatorial Current and by the equatorial zonal current system ventilating the region to the north and south of the OMZ, respectively. The interior of the OMZ is characterized by a sluggish flow regime, where mesoscale eddies play a major role in the ventilation. In this study we focus on the oxygen variability in the TNEA as well as the eddy driven lateral ventilation of the TNEA OMZ across its southern boundary. During recent years an intense measurement program was executed along 23°W cutting meridionally through the TNEA OMZ. Hydrographic and velocity data has been acquired from ship sections and moorings, together covering the latitude range between 6°S and 14°N with particularly high meridional resolution of shipboard and high temporal resolution of moored observations. Based on shipboard data we derived a meridional section of oxygen variance, which reveals numerous local maxima of oxygen variability. Exemplary, strong oxygen variability is observed at the upper (300m, 5° - 12°N) and the southern boundary (400m - 700m, 5°N - 8°N) of the OMZ, whereas the interior of the OMZ is characterized by weak variability. An application of the extended Osborn-Cox model shows that the strong oxygen variability at the southern boundary is mainly generated by mesoscale eddies. The strong variability at the upper boundary is generated by mesoscale eddies as well as microscale turbulence. We apply two methods to estimate the meridional oxygen flux: 1) a flux gradient parameterization and 2) a correlation of oxygen and velocity mooring time series. From the analysis of the 5°N mooring data we find a northward oxygen flux directed towards the OMZ at its core depth, that is mainly due to variability of

  19. Effect of oxygen concentration on singlet oxygen luminescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Longchao; Lin, Lisheng; Li, Yirong; Lin, Huiyun; Qiu, Zhihai [MOE Key Laboratory of OptoElectronic Science and Technology for Medicine, Fujian Provincial Key Laboratory for Photonics Technology, Fujian Normal University, Fuzhou 350007 (China); Gu, Ying [Department of Laser Medicine, Chinese PLA General Hospital, Beijing 100853 (China); Li, Buhong, E-mail: bhli@fjnu.edu.cn [MOE Key Laboratory of OptoElectronic Science and Technology for Medicine, Fujian Provincial Key Laboratory for Photonics Technology, Fujian Normal University, Fuzhou 350007 (China)

    2014-08-01

    Singlet oxygen ({sup 1}O{sub 2}) is a major phototoxic component in photodynamic therapy (PDT) and its generation is dependent on the availability of tissue oxygen. To examine the effect of oxygen concentration on {sup 1}O{sub 2} detection, two hydrophilic photosensitizer (PS), rose bengal (RB) and meso-metra (N-methyl-4-pyridyl) porphine tetra tosylate (TMPyP) were used as model PS. Irradiation was carried out using 523 nm under hypoxic (2%, 13%), normoxic (21%) and hyperoxic (65%) conditions. The spectral and spatial resolved {sup 1}O{sub 2} luminescence was measured by near-infrared (NIR) photomultiplier tube (PMT) and camera, respectively. Upon the irradiation, the emission signal mainly consisted of background scattering light, PS fluorescence and phosphorescence, and {sup 1}O{sub 2} luminescence. The PS phosphorescence was evidently dependent on the oxygen concentration and PS type, which resulted in the change of emission profile of {sup 1}O{sub 2} luminescence. This change was further demonstrated on {sup 1}O{sub 2} luminescence image. The present study suggests that the low oxygen concentration could affect {sup 1}O{sub 2} luminescence detection. - Highlights: • Both spectral and spatial resolved {sup 1}O{sub 2} luminescence measurements were performed. • Effect of oxygen concentration on {sup 1}O{sub 2} generation was quantitatively evaluated. • Low oxygen concentration could affect {sup 1}O{sub 2} luminescence detection.

  20. New materials for eco-sustainable electrochemical processes: oxygen evolution reaction at different electrode materials

    OpenAIRE

    Ferrara, Francesca

    2008-01-01

    In this thesis, the issue concerns the study of the oxygen evolution reaction (OER) at different electrode materials. The idea to carry out such research is connected with the key role, which OER plays in several electrochemical processes. In a future energy scenario based on renewable energy hydrogen is an attractive energy carrier. Among the others, hydrogen production by water electrolysis is a clean and simple way of storing energy from sources such as solar, wind, and hydroelectric powe...

  1. Integration of oxygen membranes for oxygen production in cement plants

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; Søgaard, Martin; Hjuler, Klaus;

    2015-01-01

    a concentrated CO2 source that can be used for enhanced oil recovery, in combination with biomass gasification and electrolysis for synthesis gas production, or possibly sequestered. The cases with oxygen enriched air provide very promising economic figures of merit with discounted payback periods slightly......The present paper describes the integration of oxygen membranes in cement plants both from an energy, exergy and economic point of view. Different configurations for oxygen enrichment of the tertiary air for combustion in the pre-calciner and full oxy-fuel combustion in both pre-calciner and kiln...

  2. Oxygen labelled CO2

    International Nuclear Information System (INIS)

    Tests were carried out as to whether additional information concerning pulmonary gas exchange could be obtained from the application of oxygen labelled carbon dioxide. Single breath experiments were performed on two healthy subjects with 0.1 percent C16O18O and 2.8 percent C18O2 in the inspiratory gas. Breath-hold time was varied between 0.5-20s in different experiments. The 18O-concentration of the end-expired gas bi-exponentially decreased with increasing breath-hold time. The high and low rate constants 4s-1 and 0.12s-1 for C18O2 and 2.5s-1 and 0.87s-1 for C16O18O were derived, respectively. These results, together with model calculations, suggest: 1) the rapid disappearance of C18O2 from the alveolar space is primarily limited by diffusion, so that this isotopic species can be applied to quantify pulmonary diffusing conditions; 2) the lower disappearance rate of C16O18O is caused by a lower equilibration kinetics in blood, so that this isotopic species offers a possibility to study carbonic anhydrase activity of the red cells in vivo; 3) the slow phase of label decay is influenced by both alveolar dead space and carbonic anhydrase activity of the pulmonary tissues. Pathological dead spaces are expected to be sensitively detectable by C16O18O as well as by C18O2. (author). 4 refs.; 4 figs

  3. Oxygenates vs. synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Kamil Klier; Richard G. Herman; Alessandra Beretta; Maria A. Burcham; Qun Sun; Yeping Cai; Biswanath Roy

    1999-04-01

    Methanol synthesis from H{sub 2}/CO has been carried out at 7.6 MPa over zirconia-supported copper catalysts. Catalysts with nominal compositions of 10/90 mol% and 30/70 mol% Cu/ZrO{sub 2} were used in this study. Additionally, a 3 mol% cesium-doped 10/90 catalyst was prepared to study the effect of doping with heavy alkali, and this promoter greatly increased the methanol productivity. The effects of CO{sub 2} addition, water injection, reaction temperature, and H{sub 2}/C0 ratio have been investigated. Both CO{sub 2} addition to the synthesis gas and cesium doping of the catalyst promoted methanol synthesis, while inhibiting the synthesis of dimethyl ether. Injection of water, however, was found to slightly suppress methanol and dimethyl ether formation while being converted to CO{sub 2} via the water gas shift reaction over these catalysts. There was no clear correlation between copper surface area and catalyst activity. Surface analysis of the tested samples revealed that copper tended to migrate and enrich the catalyst surface. The concept of employing a double-bed reactor with a pronounced temperature gradient to enhance higher alcohol synthesis was explored, and it was found that utilization of a Cs-promoted Cu/ZnO/Cr{sub 2}O{sub 3} catalyst as a first lower temperature bed and a Cs-promoted ZnO/Cr{sub 2}O{sub 3} catalyst as a second high-temperature bed significantly promoted the productivity of 2-methyl-1-propanol (isobutanol) from H{sub 2}/CO synthesis gas mixtures. While the conversion of CO to C{sub 2+} oxygenates over the double-bed configuration was comparable to that observed over the single Cu-based catalyst, major changes in the product distribution occurred by the coupling to the zinc chromite catalyst; that is, the productivity of the C{sub 1}-C{sub 3} alcohols decreased dramatically, and 2-methyl branched alcohols were selectively formed. The desirable methanol/2-methyl oxygenate molar ratios close to 1 were obtained in the present double

  4. Carrier Load Balancing and Packet Scheduling for Multi-Carrier Systems

    DEFF Research Database (Denmark)

    Wang, Yuanye; Pedersen, Klaus; Sørensen, Troels Bundgaard;

    2010-01-01

    methods for allocating the CCs to the users- Round Robin (RR) and Mobile Hashing (MH) balancing by means of a simple theoretical formulation, as well as system level simulations. At Layer-2 we propose a simple cross-CC packet scheduling algorithm that improves the coverage performance and the resource...... allocation fairness among users, as compared to independent scheduling per CC. The Long Term Evolution (LTE)-Advanced is selected for the case study of a multi-carrier system. In such a system, RR provides better performance than MH balancing, and the proposed simple scheduling algorithm is shown...

  5. How Europe's Low-Cost Carriers Sidestepped Traditional Carriers' Competitive Advantages

    DEFF Research Database (Denmark)

    Hvass, Kristian Anders

    The initial appearance of U.S. low-cost carriers forced incumbents to create new forms of competitive advantage. These were successful hindrances for nearly two decades. Concurrently, incumbents in Europe implemented similar tools, although within a regulated market. However, Europe's low......-cost airlines were more successful and had a greater initial impact in their early years than their U.S. compatriots. This paper will attempt to highlight some of the differences between the two markets and explain why European low-cost airlines had more advantages following their market deregulation...

  6. Utilization of Waste Materials for Microbial Carrier in Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    H. T. Le

    2016-01-01

    Full Text Available This research focused on the ammonium-nitrogen (NH4-N removal from the domestic wastewater using the attached growth reactors. Two types of waste material of corncob (biodegradable material and concrete (nonbiodegradable material were used as the carrier for microorganisms’ attachment. During operation, both reactors achieved absolutely high performance of ammonium removal (up to 99% and total nitrogen removal (up to 95%. The significant advantage of corncob carrier was that the corncob was able to be a source of carbon for biological denitrification, leading to no external carbon requirement for operating the system. However, the corncob caused an increasing turbidity of the effluent. On the other hand, the concrete carrier required the minimal external carbon of 3.5 C/N ratio to reach the good performance. Moreover, a longer period for microorganisms’ adaptation was found in the concrete carrier rather than the corncob carrier. Further, the same physiological and biochemical characteristics of active bacteria were found at the two carriers, which were negative gram, cocci shape, and smooth and white-turbid colony. Due to the effluent quality, the concrete was more appropriate carrier than the corncob for wastewater treatment.

  7. Hybrid nanostructured drug carrier with tunable and controlled drug release

    International Nuclear Information System (INIS)

    We describe here a transformative approach to synthesize a hybrid nanostructured drug carrier that exhibits the characteristics of controlled drug release. The synthesis of the nanohybrid architecture involved two steps. The first step involved direct crystallization of biocompatible copolymer along the long axis of the carbon nanotubes (CNTs), followed by the second step of attachment of drug molecule to the polymer via hydrogen bonding. The extraordinary inorganic–organic hybrid architecture exhibited high drug loading ability and is physically stable even under extreme conditions of acidic media and ultrasonic irradiation. The temperature and pH sensitive characteristics of the hybrid drug carrier and high drug loading ability merit its consideration as a promising carrier and utilization of the fundamental aspects used for synthesis of other promising drug carriers. The higher drug release response during the application of ultrasonic frequency is ascribed to a cavitation-type process in which the acoustic bubbles nucleate and collapse releasing the drug. Furthermore, the study underscores the potential of uniquely combining CNTs and biopolymers for drug delivery. - Graphical abstract: Block-copolymer crystallized on carbon nanotubes (CNTs). Nanohybrid drug carrier synthesized by attaching doxorubicin (DOX) to polymer crystallized CNTs. Crystallized polymer on CNTs provide mechanical stability. Triggered release of DOX. Highlights: ► The novel synthesis of a hybrid nanostructured drug carrier is described. ► The drug carrier exhibits high drug loading ability and is physically stable. ► The high drug release is ascribed to a cavitation-type process.

  8. Analysis of Ionospheric Delay Estimates from GNSS Carrier Phase Measurements

    Science.gov (United States)

    Gao, Yang

    2016-07-01

    There is an increased demand for more precise ionospheric information such as ionospheric augmentation for fast ambiguity convergence and resolution in real-time kinematic (RTK) and precise point positioning (PPP). More precise ionospheric information is also highly desired to improve the understanding of the space weather dynamics and its impacts on various applications such as aviation and communication systems. Carrier phase measurements from GNSS offer the best precision for precise applications. Current ionospheric models, however, are mostly derived from code or carrier-smoothed code measurements. Ionopsheric models based on carrier phase measurements are expected to provide improved accuracy and should be investigated. In this contribution, various data analyses will be conducted on ionospheric estimates from carrier phase measurements. Since carrier phase measurements are ambiguous and they are also affected by fractional biases, proper observation model is necessary and will be developed. With proper observation model, the analysis results are used to investigate the differences and characteristics of the ionospheric estimates between the code and carrier phase derived estimates and subsequently to help develop methods for precise estimation of the biases in carrier phase measurements and the recovery of the ionospheric effects. Data acquired at different geographic locations and under different ionospheric conditions will be processed for numerical analysis.

  9. Kinetics of Ca2+ carrier in rat liver mitochondria.

    Science.gov (United States)

    Bragadin, M; Pozzan, T; Azzone, G F

    1979-12-25

    The rate of aerobic Ca2+ transport is limited by the rate of the H+ pump rather than by the Ca2+ carrier. The kinetics of the Ca2+ carrier has therefore been studied by using the K+ diffusion potential as the driving force. The apparent Vmax of the Ca2+ carrier is, at 20 degrees C, about 900 nmol (mg of protein)-1 min-1, more than twice the rate of the H+ pump. The apparent Vmax is depressed by Mg2+ and Li+. This supports the view that the electrolytes act as noncompetitive inhibitors of the Ca2+ carrier. The degree of sigmoidicity of the kinetics of Ca2+ transport increases with the lowering of the temperature and proportionally with the concentration of impermeant electrolytes such as Mg2+ and Li+ but not choline. The effects of temperature and of electrolyte do not support the view that the sigmoidicity is due to modifications of the surface potential. Rather, they suggest that Ca2+ transport occurs through a multisubunit carrier, where cooperative phenomena are the result of ligand-induced conformational changes due to the interaction of several allosteric effectors with the carrier subunits. In contrast with La3+ which acts as a competitive inhibitor, Ruthenium Red affects the kinetics by inducing phenomena both of positive and of negative cooperativity. The Ruthenium Red induced kinetics has been reproduced through curve-fitting procedures by applying the Koshland sequential interaction hypothesis to a four-subunit Ca2+ carrier model. PMID:42437

  10. Continuous GPS Carrier-Phase Time Transfer

    Science.gov (United States)

    Yao, Jian

    Time transfer (TT) is the process of transmitting a timing signal from one place to another place. It has applications to the formation and realization of Coordinated Universal Time (UTC), telecommunications, electrical power grids, and even stock exchanges. TT is the actual bottleneck of the UTC formation and realization since the technology of atomic clocks is almost always ahead of that of TT. GPS carrier-phase time transfer (GPSCPTT), as a mainstream TT technique accepted by most national timing laboratories, has suffered from the day-boundary-discontinuity (day-BD) problem for many years. This makes us difficult to observe a remote Cesium fountain clock behavior even after a few days. We find that day-BD comes from the GPS code noise. The day-BD can be lowered by ˜40% if more satellite-clock information is provided and if a few GPS receivers at the same station are averaged. To completely eliminate day-BD, the RINEX-Shift (RS) and revised RS (RRS) algorithms have been designed. The RS/RRS result matches the two-way satellite time/frequency transfer (TWSTFT) result much better than the conventional GPSCPTT result. With the RS/RRS algorithm, we are able to observe a remote Cesium fountain after half a day. We also study the BD due to GPS data anomalies (anomaly-BD). A simple curve-fitting strategy can eliminate the anomaly-BD. Thus, we achieve continuous GPSCPTT after eliminating both day-BD and anomaly-BD.

  11. Participation of Low Molecular Weight Electron Carriers in Oxidative Protein Folding

    Directory of Open Access Journals (Sweden)

    József Mandl

    2009-03-01

    Full Text Available Oxidative protein folding is mediated by a proteinaceous electron relay system, in which the concerted action of protein disulfide isomerase and Ero1 delivers the electrons from thiol groups to the final acceptor. Oxygen appears to be the final oxidant in aerobic living organisms, although the existence of alternative electron acceptors, e.g. fumarate or nitrate, cannot be excluded. Whilst the protein components of the system are well-known, less attention has been turned to the role of low molecular weight electron carriers in the process. The function of ascorbate, tocopherol and vitamin K has been raised recently. In vitro and in vivo evidence suggests that these redox-active compounds can contribute to the functioning of oxidative folding. This review focuses on the participation of small molecular weight redox compounds in oxidative protein folding.

  12. Chemical and Physical Effects of the Carrier Gas on the Atmospheric Pressure PECVD of Fluorinated Precursors

    CERN Document Server

    Hubert, Julie; Mertens, Jérémy; Viville, Pascal; Dufour, Thierry; Barroo, Cédric; de Bocarmé, Thierry Visart; Lazzaroni, Roberto; Reniers, François

    2016-01-01

    The atmospheric pressure PECVD deposition and texturization of hydrophobic coatings using liquid fluorinated C6F12 and C6F14 precursors are investigated. The effect of the carrier gas (argon and helium) is discussed in terms of the behavior of the gas phase and of the characteristics of the deposited film. Mass spectrom-etry measurements indicate that the fragmentation is higher with argon while helium reacts very easily with oxygen impurities leading to the formation of CxFyOz compounds. These observations are consistent with the chemical composition of the films determined by XPS and the variation in the deposition rate. Moreover, the streamers present in the argon discharge affect the morphology of the surface by increasing the roughness, which leads to the increase in the hydrophobicity of the coatings.

  13. Distribution of charge carriers in dissipative structure of semiconductors

    CERN Document Server

    Kamilov, I K; Kovalev, A S

    2002-01-01

    It has been shown experimentally that redistribution of the charge carrier concentration takes place in the volume of Te and InSb monocrystals under formation and excitation by the strong field of a dissipative structure in nonequilibrium electron-hole plasma. This leads to a situation when the presence of only longitudinal autosolitons in the dissipative structure reduces the charge carrier concentration outside autosolitons while the presence of only transversal autosolitons makes the charge carriers concentration larger. These effects are explained in the following manner: longitudinal autosolitons, occurring in nonequilibrium electron-hole plasma created by the Joule heating are considered as cold and transversal autosolitons are considered as hot ones

  14. Laccase immobilized on magnetic carriers for biotechnology applications

    Energy Technology Data Exchange (ETDEWEB)

    Rotkova, Jana [Department of Biological and Biochemical Sciences, University of Pardubice, Strossova 239, 530 03 Pardubice (Czech Republic); Sulakova, Romana [Department of Technology of Organic Compounds, Doubravice 41, 533 53 Pardubice (Czech Republic); Korecka, Lucie; Zdrazilova, Pavla; Jandova, Miroslava [Department of Biological and Biochemical Sciences, University of Pardubice, Strossova 239, 530 03 Pardubice (Czech Republic); Lenfeld, Jiri; Horak, Daniel [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovskeho nam. 2, 162 06 Praha (Czech Republic); Bilkova, Zuzana [Department of Biological and Biochemical Sciences, University of Pardubice, Strossova 239, 530 03 Pardubice (Czech Republic)], E-mail: Zuzana.Bilkova@upce.cz

    2009-05-15

    Laccase catalyzing the oxidation of p-diphenols has been applied in many industrial and biotechnology areas. Immobilized form of laccase has overcome the problem with contamination of the final product. Nevertheless sensitive enzymes immobilized to the matrix can be inactivated by the environmental conditions. The aim of this research was to prepare carrier with improved activity and responsible stability even under extreme reaction conditions. Laccase immobilized through carbohydrate moieties on magnetic hydrazide bead cellulose with a final activity of 0.63 I.U./1 ml of settled carrier confirmed that carriers with oriented immobilized enzyme might be useful in routine biocatalytic applications.

  15. Recent advances in topical formulation carriers of antifungal agents.

    Science.gov (United States)

    Bseiso, Eman Ahmed; Nasr, Maha; Sammour, Omaima; Abd El Gawad, Nabaweya A

    2015-01-01

    Fungal infections are amongst the most commonly encountered diseases affecting the skin. Treatment approaches include both topical and oral antifungal agents. The topical route is generally preferred due to the possible side effects of oral medication. Advances in the field of formulation may soon render outdated conventional products such as creams, ointments and gels. Several carrier systems loaded with antifungal drugs have demonstrated promising results in the treatment of skin fungal infections. Examples of these newer carriers include micelles, lipidic systems such as solid lipid nanoparticles and nanostructured lipid carriers, microemulsions and vesicular systems such as liposomes, niosomes, transfersomes, ethosomes, and penetration enhancer vesicles. PMID:26261140

  16. Safety and environmental aspects in LNG carrier design

    International Nuclear Information System (INIS)

    'Safety and Reliability' has been and will continue to be a key phr ase in marine transportation of LNG. Mitsui Engineering and Shipbuilding Co.,Ltd. has utilized its all expertise and state of art technologies to realize this objective, resulting in exceptionally successful operations of LNG carrier built by the Co. In line with growing global concern about environmental issues, we need to pay more attention to the environmental aspects of the design and construction of LNG carriers. Accordingly, in this paper, we present some topics related safety and environmental concerns which need to be taken into consideration in LNG carriers design and construction. (Author). 7 figs

  17. Proposal for tutorial: Resilience in carrier Ethernet transport

    DEFF Research Database (Denmark)

    Berger, Michael Stübert; Wessing, Henrik; Ruepp, Sarah Renée

    2009-01-01

    Operation, Administration and Management (OAM) functionalities and support for Quality of Service (QoS), required to obtain carrier grade quality. This tutorial provides an overview of the current level of standardization followed by an exhaustive survey of Carrier Ethernet reliability. A number...... of enhancements are still required to make Carrier Ethernet ready for large scale deployments of reliable point-to-multipoint services. The tutorial highlights the necessary enhancements and shows possible solutions and directions towards reliable multicast. Explicit focus is on OAM for multicast, where...

  18. Do Low Cost Carriers Provide Low Quality Service?

    Directory of Open Access Journals (Sweden)

    Tejashree Sayanak

    2008-03-01

    Full Text Available This paper addresses the question of whether low cost carriers provide low quality service. Considerable work has been done on various aspects of airline service quality, including: examining the causes of flight delays and cancellations, investigating service quality during irregular airport operations, and exploring the link between on-time performance and airline ticket prices. Little research has been conducted, however, on the performance of low cost carriers. This paper attempts to fill this void in the literature by examining the on-time performance of six million domestic flights in 2006. We find considerable evidence indicating that low cost carriers offer more reliable flight schedules.

  19. Recent advances in topical formulation carriers of antifungal agents

    Directory of Open Access Journals (Sweden)

    Eman Ahmed Bseiso

    2015-01-01

    Full Text Available Fungal infections are amongst the most commonly encountered diseases affecting the skin. Treatment approaches include both topical and oral antifungal agents. The topical route is generally preferred due to the possible side effects of oral medication. Advances in the field of formulation may soon render outdated conventional products such as creams, ointments and gels. Several carrier systems loaded with antifungal drugs have demonstrated promising results in the treatment of skin fungal infections. Examples of these newer carriers include micelles, lipidic systems such as solid lipid nanoparticles and nanostructured lipid carriers, microemulsions and vesicular systems such as liposomes, niosomes, transfersomes, ethosomes, and penetration enhancer vesicles.

  20. Analytical carrier density and quantum capacitance for graphene

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lingfei; Wang, Wei; Xu, Guangwei; Ji, Zhuoyu; Lu, Nianduan, E-mail: lunianduan@ime.ac.cn; Li, Ling, E-mail: lingli@ime.ac.cn; Liu, Ming [Key Laboratory of Microelectronics Devices and Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China); Laboratory of Nanofabrication and Novel Device Integration, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China)

    2016-01-04

    A disorder based analytical carrier density for graphene is presented here. The carrier density, a basic property of all semiconductors, is obtained based on exponential distribution describing the potential fluctuations induced by impurities and shows good agreement with numerical results. The quantum capacitance is subsequently derived from the carrier density, with a good agreement with experimental measurements. A method for extracting the gate coupling function is also proposed, which relates the internal surface potential with the external applied gate voltage. The essential properties of graphene device physics, such as the temperature, material disorder, and surface potential dependences, are captured in these analytical equations.

  1. Wafer-scale characterization of carrier dynamics in graphene

    DEFF Research Database (Denmark)

    Buron, Jonas Christian Due; Petersen, Dirch Hjorth; Bøggild, Peter;

    2015-01-01

    The electronic properties of single-layer graphene, such as surface conductance, carrier concentration, scattering time and mobility, can be characterized in a noncontact manner by THz time-domain spectroscopy. Standard spectroscopic imaging reveals the AC conductance over large areas with a few...... hundred μm resolution, and spectroscopic imaging on back-gated graphene allows for extraction of both the carrier concentration and the mobility. We find that spatial variations of the conductance of single-layer CVD-grown graphene are predominantly due to variations in mobility rather than in carrier...

  2. BER Performance of IEEE 802.11ad for Single Carrier and Multi Carrier

    Directory of Open Access Journals (Sweden)

    Abhishek Kumar Gupta

    2012-05-01

    Full Text Available In present scenario 802.11n is one of the fastest standards which is widely popular. It provides a theoretical maximum of 450 megabits per second (Mbps, with a typical throughput of 100Mbps. As we know, there is high demand for higher speed due to an increasing of high definition (HD video on smart phone usage and home entertainment. As 802.11n is not able to provide the required speed needed for these uses, thus there is need for technologies which can meet therequirement. IEEE 802.11ad is one of such standards which meet the requirement needed for the above. IEEE 802.11ad standard operates at 60 GHz frequency, promise to deliver from 1 to 7 Gbps. 60 GHz band is one of the largest unlicensed bandwidth with availability of at least 5 GHz of continuous bandwidth worldwide. In this paper we have tested the IEEE 802.11ad system model Bits Error Rate (BER for different modulation technique under several coding scheme for both Single Carrier and Multi Carriers. In this model the modulation technique mainly used are Binary Phase Shift Keying (BPSK, Quaternary Phase Shift Keying (QPSK, 16-Quadrature Amplitude Modulation (QAM, 64-Quadrature Amplitude Modulation (QAM and the coding scheme used is Low Density Parity Check (LDPC code with different code rate.

  3. A pseudodeficiency allele common in non-Jewish Tay-Sachs carriers: Implications for carrier screening

    Energy Technology Data Exchange (ETDEWEB)

    Triggs-Raine, B.L.; Akerman, B.R.; Gravel, R.A. (McGill Univ.-Montreal Children' s Hospital Research Institute, Montreal, Quebec (Canada)); Mules, E.H.; Thomas, G.H.; Dowling, C.E. (Johns Hopkins School of Medicine, Baltimore, MD (United States)); Kaback, M.M.; Lim-Steele, J.S.T. (Univ. of California, San Diego, CA (United States)); Natowicz, M.R. (Eunice Kennedy Shriver Center for Mental Retardation, Waltham, MA (United States)); Grebner, E.E. (Thomas Jefferson Univ., Philadelphia, PA (United States)); Navon, R.R. (Tel-Aviv Univ., Kfar-Sava (Israel)); Welch, J.P. (Dalhousie Univ., Halifax, Nova, Scotia (Canada)); Greenberg, C.R. (Univ. of Manitoba, Winnipeg (Canada))

    1992-10-01

    Deficiency of [beta]-hexosaminidase A (Hex A) activity typically results in Tay-Sachs disease. However, healthy subjects found to be deficient in Hex A activity (i.e., pseudodeficient) by means of in vitro biochemical tests have been described. The authors analyzed the HEXA gene of one pseudodeficient subject and identified both a C[sub 739]-to-T substitution that changes Arg[sub 247][yields]Trp on one allele and a previously identified Tay-Sachs disease mutation of the second allele. Six additional pseudodeficient subjects were found to have the C[sub 739]-to-T but for none of 36 Jewish enzyme-defined carries who did not have one of three known mutations common to this group. The C[sub 739]-to-T allele, together with a [open quotes]true[close quotes] Tay-Sachs disease allele, causes Hex A pseudodeficiency. Given both the large proportion of non-Jewish carriers with this allele and that standard biochemical screening cannot differentiate between heterozygotes for the C[sub 739]-to-T mutations and Tay-Sachs disease carriers, DNA testing for this mutation in at-risk couples is essential. This could prevent unnecessary or incorrect prenatal diagnoses. 40 refs., 3 figs., 4 tabs.

  4. The Design of Bulk Carrier Cargo Holds State Integrated Monitoring System

    Directory of Open Access Journals (Sweden)

    Gao Ru-jiang

    2016-01-01

    Full Text Available Most ship cargo hold Internal uses artificial watch or is unattended. Therefore, it is impossible to know the appropriate information of the cargo holds Internal timely and accurately. Cargo damage and ship accidents occurred frequently. Automation remote processing and monitoring alarm system for the bulk carrier is an important part of the marine automation. The system plays a significant role to guarantee the navigation safety for bulk carriers. The paper introduced the important parts of the integrated monitoring system, structural design, hardware configuration, various modules communication transmission and various data processing software design were included. Based on embedded development, the real time information including the cargo hold internal humidity temperature, oxygen concentration, smoke gas concentration, cold water well level and other data were collected, as well the hatch closed state was detected and the cargo hold internal real time video information was collected. Then the real-time communication between the control display and acquisition modules were assured. By adjusting the corresponding buttons on the bridge according to the monitoring information, so that the cargo hold always in a safe environment, so as to avoid cargo hold accidents.

  5. Electrical Conductivity of Rocks and Dominant Charge Carriers. Part 1; Thermally Activated Positive Holes

    Science.gov (United States)

    Freund, Friedemann T.; Freund, Minoru M.

    2012-01-01

    The prevailing view in the geophysics community is that the electrical conductivity structure of the Earth's continental crust over the 5-35 km depth range can best be understood by assuming the presence of intergranular fluids and/or of intragranular carbon films. Based on single crystal studies of melt-grown MgO, magma-derived sanidine and anorthosite feldspars and upper mantle olivine, we present evidence for the presence of electronic charge carriers, which derive from peroxy defects that are introduced during cooling, under non-equilibrium conditions, through a redox conversion of pairs of solute hydroxyl arising from dissolution of H2O.The peroxy defects become thermally activated in a 2-step process, leading to the release of defect electrons in the oxygen anion sublattice. Known as positive holes and symbolized by h(dot), these electronic charge carriers are highly mobile. Chemically equivalent to O(-) in a matrix of O(2-) they are highly oxidizing. Being metastable they can exist in the matrix of minerals, which crystallized in highly reduced environments. The h(dot) are highly mobile. They appear to control the electrical conductivity of crustal rocks in much of the 5-35 km depth range.

  6. What Are the Risks of Oxygen Therapy?

    Science.gov (United States)

    ... NHLBI on Twitter. What Are the Risks of Oxygen Therapy? Oxygen therapy can cause complications and side effects. These ... problem, your doctor may need to change your oxygen flow rate or the length of time you' ...

  7. Oxygen-Methane Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Two main innovations will be developed in the Phase II effort that are fundamentally associated with our gaseous oxygen/gaseous methane RCS thruster. The first...

  8. Echocardiography in military oxygen divers.

    OpenAIRE

    Boussuges, Alain; Riera, Florence; Rossi, Pascal; Castagna, Olivier; Galland, François; Blatteau, Jean-Eric

    2007-01-01

    BACKGROUND: Oxygen divers undergo environmental stressors such as immersion, ventilation with scuba, cold exposure, and increased ambient pressure. All of these stressors may be responsible for acute hemodynamic modifications. We hypothesized that repeated hyperbaric hyperoxia exposure induces long-term cardiovascular modifications. METHODS: A Doppler echocardiography was conducted on 20 military oxygen divers (average 12 yr diving experience) and compared with 22 controls. Parameters known t...

  9. Oxygen Regulates Tissue Nitrite Metabolism

    OpenAIRE

    Curtis, Erin; Hsu, Lewis L.; Noguchi, Audrey C.; Geary, Lisa; Shiva, Sruti

    2012-01-01

    Aims: Once dismissed as an inert byproduct of nitric oxide (NO) auto-oxidation, nitrite (NO2-) is now accepted as an endocrine reservoir of NO that elicits biological responses in major organs. While it is known that tissue nitrite is derived from NO oxidation and the diet, little is known about how nitrite is metabolized by tissue, particularly at intermediate oxygen tensions. We investigated the rates and mechanisms of tissue nitrite metabolism over a range of oxygen concentrations. Results...

  10. Wet steam treatment with oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Ruehle, W.; Enkler, G. [EnBW Kraftwerke AG, Kernkraftwerk Philippsburg (Germany)

    1999-07-01

    After many years of excellent results using high all volatile treatment (HAVT) for operation of the secondary system of a PWR, flow assisted corrosion in the heating pipes of the intermediate steam reheaters has been experienced. Oxygen addition into the heating steam before the reheater is expected to improve the protective oxide layers formation. The reaction of oxygen with the alkalizing steam ingredients is described. (orig.)

  11. Aging in Fragile X Premutation Carriers.

    Science.gov (United States)

    Lozano, Reymundo; Saito, Naomi; Reed, Dallas; Eldeeb, Marwa; Schneider, Andrea; Hessl, David; Tassone, Flora; Beckett, Laurel; Hagerman, Randi

    2016-10-01

    It is now recognized that FMR1 premutation carriers (PC) are at risk to develop a range of neurological, psychiatric, and immune-mediated disorders during adulthood. There are conflicting findings regarding the incidence of hypertension, hypothyroidism, diabetes, and cancer in these patients that warrant further study. A retrospective controlled study was performed in a convenience sample of 248 controls (130 men, 118 women) and 397 FMR1 PC with and without fragile X-associated tremor ataxia syndrome (FXTAS) (176 men, 221 women); all participants were at least 45 years old (men: mean 62.4, SD 9.5; women: mean 62.8, SD 9.9; p = 0.63). Memory and cognitive assessments (Wechsler Adult Intelligence Scale (WAIS-III), Wechsler Memory Scale (WMS-III)) and molecular testing (CGG repeats and FMR1-mRNA levels) were performed. Additional data included body mass index (BMI), cholesterol levels, blood pressure, hemoglobin A1c (HbA1c) levels, and medical history. A higher percentage of PC subjects self-reported having a diagnosis of hypertension (50.0 vs. 35.0 %, p = 0.006) and thyroid problems (20.4 vs. 10.0 %, p = 0.012) than control subjects. When comparing controls versus PC with FXTAS, the association was higher for diabetes (p = 0.043); however, the effect was not significant after adjusting for demographic predictors. Blood pressure, blood glucose levels, HbA1c, and BMI values were not significantly different between the two groups. The PC with FXTAS group performed consistently lower in neuropsychological testing compared with the PC without FXTAS group, but the differences were very small for all but the WAIS full-scale IQ. Based on these findings, it appears that the risk for hypertension, thyroid problems, and diabetes may be more frequent in PC with FXTAS, which will require verification in future studies. PMID:27334385

  12. Perfluorocarbon (PFC) emulsions as potential drug carriers

    International Nuclear Information System (INIS)

    PFC emulsions have excellent oxygen transporting properties and have been reported to enhance the response of murine tumors to both radiation and BCNU. While the presently available emulsions are far too toxic to the immune system to be used in cancer therapy, they can be used to investigate the overall potential of this approach. As an example, the authors have found that these emulsions can alter drug availability. The lipophilicity of both the PFC and the drug in question determine the partitioning of the drug between the organic and aqueous phases of an emulsion. In vitro, this can reduce drug effectiveness by reducing the amount of drug available to the cells. In vivo, however, this partitioning may produce sustained drug exposure, which could be of benefit in cancer therapy and other applications. In brief, as the drug is absorbed from the circulating aqueous phase, additional drug would leach from the PFC, thereby providing a sustained drug exposure similar to that obtained with liposomes. While a great deal more work will be required to evaluate the practicality of this approach, the existence of this phenomenon must be taken into account in both the design and interpretation of efficacy studies in which anesthetics, chemotherapeutics, etc are employed

  13. Allothermal gasification of biomass into chemicals and secondary energy carriers

    Energy Technology Data Exchange (ETDEWEB)

    Zwart, R.W.R. [ECN Biomass, Coal and Environmental Research, Petten (Netherlands)

    2009-09-15

    The outline of this presentation on the title subject states: Motivation for polygeneration; Allothermal gasification: the MILENA at ECN; Primary gas cleaning: the OLGA for tar removal; Possible secondary energy carriers; Possible chemicals; Polygeneration concept and its feasibility.

  14. Discriminator aided phase lock acquisition for suppressed carrier signals

    Science.gov (United States)

    Carson, L. M.; Krasin, F. E. (Inventor)

    1982-01-01

    A discriminator aided technique for acquisition of phase lock to a suppressed carrier signal utilizes a Costas loop which is initially operated open loop and control voltage for its VCXO is derived from a phase detector that compares the VCXO to a reference frequency thus establishing coarse frequency resolution with the received signal. Then the Costas loop is closed with the low-pass filter of the channel having a bandwidth much greater (by a factor of about 10) than in the I channel so that a frequency discriminator effect results to aid carrier resolution. Finally, after carrier acquisition, the Q-channel filter of the Costas loop is switched to a bandwidth substantially equal to that of the I-channel for carrier tracking.

  15. 47 CFR 54.405 - Carrier obligation to offer Lifeline.

    Science.gov (United States)

    2010-10-01

    ... (CONTINUED) UNIVERSAL SERVICE Universal Service Support for Low-Income Consumers § 54.405 Carrier obligation... service, as defined in § 54.401, to qualifying low-income consumers, and (b) Publicize the availability...

  16. Low temperature carrier transport properties in isotopically controlled germanium

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, K.

    1994-12-01

    Investigations of electronic and optical properties of semiconductors often require specimens with extremely homogeneous dopant distributions and precisely controlled net-carrier concentrations and compensation ratios. The previous difficulties in fabricating such samples are overcome as reported in this thesis by growing high-purity Ge single crystals of controlled {sup 75}Ge and {sup 70}Ge isotopic compositions, and doping these crystals by the neutron transmutation doping (NTD) technique. The resulting net-impurity concentrations and the compensation ratios are precisely determined by the thermal neutron fluence and the [{sup 74}Ge]/[{sup 70}Ge] ratios of the starting Ge materials, respectively. This method also guarantees unprecedented doping uniformity. Using such samples the authors have conducted four types of electron (hole) transport studies probing the nature of (1) free carrier scattering by neutral impurities, (2) free carrier scattering by ionized impurities, (3) low temperature hopping conduction, and (4) free carrier transport in samples close to the metal-insulator transition.

  17. Stacking dependence of carrier transport properties in multilayered black phosphorous

    Science.gov (United States)

    Sengupta, A.; Audiffred, M.; Heine, T.; Niehaus, T. A.

    2016-02-01

    We present the effect of different stacking orders on carrier transport properties of multi-layer black phosphorous. We consider three different stacking orders AAA, ABA and ACA, with increasing number of layers (from 2 to 6 layers). We employ a hierarchical approach in density functional theory (DFT), with structural simulations performed with generalized gradient approximation (GGA) and the bandstructure, carrier effective masses and optical properties evaluated with the meta-generalized gradient approximation (MGGA). The carrier transmission in the various black phosphorous sheets was carried out with the non-equilibrium green’s function (NEGF) approach. The results show that ACA stacking has the highest electron and hole transmission probabilities. The results show tunability for a wide range of band-gaps, carrier effective masses and transmission with a great promise for lattice engineering (stacking order and layers) in black phosphorous.

  18. Carrier screening in preconception consultation in primary care.

    Science.gov (United States)

    Metcalfe, Sylvia A

    2012-07-01

    Discussing carrier screening during preconception consultation in primary care has a number of advantages in terms of promoting autonomy and enabling the greatest range of reproductive choices. For those with a family history of an inherited condition, this ought to be a routine discussion; however, this can be expanded to include the wider population, especially for those conditions for which carrier frequencies are considered relatively common. There is published literature from around the world regarding experiences with carrier screening in primary care for cystic fibrosis, haemoglobinopathies, fragile X syndrome, Tay-Sachs disease and spinal muscular atrophy, although many of these have tended to focus on consultations during rather than before pregnancy. Overall, these studies reveal that population carrier screening is well received by the participants with apparent minimal psychosocial harms; however, challenges exist in terms of approaches to ensure couples receive adequate information to make personally relevant decisions and for ongoing health professional engagement. PMID:22183783

  19. Extending the unambiguous velocity range using multiple carrier frequencies

    DEFF Research Database (Denmark)

    Zhang, Z.; Jakobsson, A.; Nikolov, Svetoslav;

    2005-01-01

    Typically, velocity estimators based on the estimation of the Doppler shift will suffer from a limited unambiguous velocity range. Proposed are two novel multiple carrier based velocity estimators extending the velocity range above the Nyquist velocity limit. Numerical simulations indicate...

  20. Next-generation carrier screening: are we ready?

    OpenAIRE

    Thomas W Prior

    2014-01-01

    Editorial summary Next-generation sequencing (NGS) methodology allows for a major expansion in current carrier screening tests. NGS testing has been shown to be analytically accurate and cost-effective, but major challenges include educational and counseling issues.

  1. Synthetic heat carrier oil compositions based on polyalkylene glycols

    International Nuclear Information System (INIS)

    The results of syntheses of heat carrier oils based on polyalkylene glycols (PAGs) using suitable additives have been reported. Polyalkylene glycols have been prepared by heating diethylene glycol, propylene oxide, glycols, adipic acid and 2-ethyhexanol in the presence of KOH and stannyl octoate as catalyst in the molar ratio to give proper physical properties and viscosity-temperature index. The prepared PAGs have been taken as basic components for heat carrier oil compositions. In order to improve the thermal stability and viscosity indices, as well as other specifications, anti-oxidant and anti-foaming additives were added to the base material to reach optimum compositions. Thermal stability, mass loss on vaporization at 250 oC, 350 oC and changing the specifications after heating at 300 oC for 10 h have also been investigated. The obtained heat carrier oils showed comparable improved properties in comparison with commercially available heat carriers

  2. GUI Application for ATCA-based LLRF Carrier Board Management

    CERN Document Server

    Wychowaniak, Jan; Predki, Pawel; Napieralski, Andrzej

    2011-01-01

    The Advanced Telecommunications Computing Architecture (ATCA) standard describes an efficient and powerful platform, implementation of which was adopted to be used as a base for control systems in high energy physics. The ATCA platform is considered to be applied for the X-ray Free Electron Laser (X-FEL), being built at Deutsches Electronen- Synchrotron (DESY) in Hamburg, Germany. The Low Level Radio Frequency (LLRF) control system is composed of a few ATCA Carrier Boards. Carrier Board hosts Intelligent Platform Management Controller (IPMC), which is developed in compliance with the PICMG specifications. IPMC is responsible for management and monitoring of sub-modules installed on Carrier Boards and pluggable Advanced Mezzanine Card (AMC) modules. The ATCA Shelf Manager is the main control unit of a single ATCA crate, responsible for all power and fan modules and Carrier Boards installed in ATCA shelf. The device provides a system administrator with a set of control and diagnostic capabilities regarding the ...

  3. 47 CFR 73.1545 - Carrier frequency departure tolerances.

    Science.gov (United States)

    2010-10-01

    ... carrier offset, including those stations licensed with a maximum effective radiated power and/or antenna... offset. See Memorandum Opinion and Order on Reconsideration, In the Matter of Establishment of a Class...

  4. An Estimation Method for number of carrier frequency

    Directory of Open Access Journals (Sweden)

    Xiong Peng

    2015-01-01

    Full Text Available This paper proposes a method that utilizes AR model power spectrum estimation based on Burg algorithm to estimate the number of carrier frequency in single pulse. In the modern electronic and information warfare, the pulse signal form of radar is complex and changeable, among which single pulse with multi-carrier frequencies is the most typical one, such as the frequency shift keying (FSK signal, the frequency shift keying with linear frequency (FSK-LFM hybrid modulation signal and the frequency shift keying with bi-phase shift keying (FSK-BPSK hybrid modulation signal. In view of this kind of single pulse which has multi-carrier frequencies, this paper adopts a method which transforms the complex signal into AR model, then takes power spectrum based on Burg algorithm to show the effect. Experimental results show that the estimation method still can determine the number of carrier frequencies accurately even when the signal noise ratio (SNR is very low.

  5. Cell carriers for oncolytic viruses: current challenges and future directions.

    Science.gov (United States)

    Roy, Dominic G; Bell, John C

    2013-01-01

    The optimal route for clinical delivery of oncolytic viruses is thought to be systemic intravenous injection; however, the immune system is armed with several highly efficient mechanisms to remove pathogens from the circulatory system. To overcome the challenges faced in trying to delivery oncolytic viruses specifically to tumors via the bloodstream, carrier cells have been investigated to determine their suitability as delivery vehicles for systemic administration of oncolytic viruses. Cell carriers protect viruses from neutralization, one of the most limiting aspects of oncolytic virus interaction with the immune system. Cell carriers can also possess inherent tumor tropism, thus directing the delivery of the virus more specifically to a tumor. With preclinical studies already demonstrating the success and feasibility of this approach with multiple oncolytic viruses, clinical evaluation of cell-mediated delivery of viruses is on the horizon. Meanwhile, ongoing preclinical studies are aimed at identifying new cellular vehicles for oncolytic viruses and improving current promising cell carrier platforms. PMID:27512657

  6. Nonequilibrium carrier dynamics in transition metal dichalcogenide semiconductors

    Science.gov (United States)

    Steinhoff, A.; Florian, M.; Rösner, M.; Lorke, M.; Wehling, T. O.; Gies, C.; Jahnke, F.

    2016-09-01

    When exploring new materials for their potential in (opto)electronic device applications, it is important to understand the role of various carrier interaction and scattering processes. In atomically thin transition metal dichalcogenide semiconductors, the Coulomb interaction is known to be much stronger than in quantum wells of conventional semiconductors like GaAs, as witnessed by the 50 times larger exciton binding energy. The question arises, whether this directly translates into equivalently faster carrier–carrier Coulomb scattering of excited carriers. Here we show that a combination of ab initio band-structure and many-body theory predicts Coulomb-mediated carrier relaxation on a sub-100 fs time scale for a wide range of excitation densities, which is less than an order of magnitude faster than in quantum wells.

  7. Stacking dependence of carrier transport properties in multilayered black phosphorous.

    Science.gov (United States)

    Sengupta, A; Audiffred, M; Heine, T; Niehaus, T A

    2016-02-24

    We present the effect of different stacking orders on carrier transport properties of multi-layer black phosphorous. We consider three different stacking orders AAA, ABA and ACA, with increasing number of layers (from 2 to 6 layers). We employ a hierarchical approach in density functional theory (DFT), with structural simulations performed with generalized gradient approximation (GGA) and the bandstructure, carrier effective masses and optical properties evaluated with the meta-generalized gradient approximation (MGGA). The carrier transmission in the various black phosphorous sheets was carried out with the non-equilibrium green's function (NEGF) approach. The results show that ACA stacking has the highest electron and hole transmission probabilities. The results show tunability for a wide range of band-gaps, carrier effective masses and transmission with a great promise for lattice engineering (stacking order and layers) in black phosphorous. PMID:26809017

  8. Metal-insulator transition in SrTiO(3-x) thin films induced by frozen-out carriers.

    Science.gov (United States)

    Liu, Z Q; Leusink, D P; Wang, X; Lü, W M; Gopinadhan, K; Annadi, A; Zhao, Y L; Huang, X H; Zeng, S W; Huang, Z; Srivastava, A; Dhar, S; Venkatesan, T; Ariando

    2011-09-30

    We report optical, electrical and magnetotransport properties of oxygen deficient SrTiO(3) (SrTiO(3-x)) thin films fabricated by pulsed laser deposition technique. The oxygen vacancies (O(vac)) in the thin film are expected to be uniform. By comparing its electrical properties to those of bulk SrTiO(3-x), it was found that O(vac) in bulk SrTiO(3-x) is far from uniform over the whole material. The metal-insulator transition (MIT) observed in the SrTiO(3-x) film was found to be induced by the carrier freeze-out effect. The low temperature frozen state can be reexcited by Joule heating, electric and intriguingly magnetic field. PMID:22112172

  9. Oxygen and Early Animal Evolution

    Science.gov (United States)

    Xiao, S.

    2012-12-01

    It is often hypothesized that the rise of animals was triggered by an increase in O2 levels in the atmosphere and oceans. However, this hypothesis is remarkably difficult to test, because the timing of animal divergences is poorly resolved, the physiology of early animals is often unknown, estimates of past pO2 levels come with large error bars, and causal relationships between oxygenation and animal evolution are difficult to establish. Nonetheless, existing phylogenetic, paleontological, and geochemical data indicate that the evolution of macroscopic animals and motile macrometazoans with energetically expensive lifestyles may be temporally coupled with ocean oxygenation events in the Ediacaran Period. Thus, it is plausible that ocean oxygenation may have been a limiting factor in the early evolution of macroscopic, complex, and metabolically aggressive animals (particularly bilaterian animals). However, ocean oxygenation and animal evolution were likely engaged in two-way interactions: Ediacaran oxygenation may have initially lifted a physiological barrier for the evolution of animal size, motility, and active lifestyles, but subsequent animal diversification in the Paleozoic may have also changed oceanic redox structures. Viewed in a broader context, the early evolutionary history of animals was contingent upon a series of events, including genetic preparation (developmental genetics), environmental facilitation (oceanic oxygenation), and ecological escalation (Cambrian explosion), but the rise of animals to ecological importance also had important geobiological impacts on oceanic redox structures, sedimentary fabrics, and global geochemical cycles.

  10. Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals

    DEFF Research Database (Denmark)

    Falås, Per; Baillon-Dhumez, Aude; Andersen, Henrik Rasmus;

    2012-01-01

    Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct ...... bacteria to degrade or transform the target pharmaceuticals was further demonstrated by the limited pharmaceutical removal in an experiment with continuous nitritation and biofilm carriers from a partial nitritation/anammox sludge liquor treatment process....

  11. Study on Papain Immobilization on a Macroporous Polymer Carrier

    OpenAIRE

    Ding, Liang; YAO, Zihua; Li, Tong

    2003-01-01

    Macroporous resin microbeads of methyl methacrylate-divinyl benzene copolymer were synthesized by radical suspension polymerization of acrolein with divinylbenzene in the presence of a pore-creating agent, petroleum ether. The microbeads had a large specific surface area and large pores covered the entire surface of the resin. This macroporous polymer carrier was aminated by hydrazine hydrate that produced a large number of amino groups on the carrier. Papain was immobilized on the ...

  12. Dispersion and polarization dependence of mobile carrier optical nonlinearities

    Science.gov (United States)

    Rustagi, K. C.

    1984-06-01

    Based on the author's earlier work, it is shown that the proper inclusion of carrier scattering should strongly modify the frequency and polarization dependence of optical nonlinearities due to mobile carriers in semiconductors. When the momentum relaxation is much faster than the energy relaxation, the intensity dependent refractive index is enhanced, the induced birefringence becomes a sharp function of the difference frequency ωa-ωb, and a collision induced stimulated Raman effect becomes important.

  13. Carrier screening in preconception consultation in primary care

    OpenAIRE

    Metcalfe, Sylvia A

    2011-01-01

    Discussing carrier screening during preconception consultation in primary care has a number of advantages in terms of promoting autonomy and enabling the greatest range of reproductive choices. For those with a family history of an inherited condition, this ought to be a routine discussion; however, this can be expanded to include the wider population, especially for those conditions for which carrier frequencies are considered relatively common. There is published literature from around the ...

  14. Review of Magnetic Carrier Technologies for Metal Ion Removal

    OpenAIRE

    Broomberg, J.; Gélinas, S.; Finch, James A.; Xu, Z.

    1999-01-01

    Magnetic carriers are magnetic materials designed to bind selectively on some non -magnetic materials to make them separable using magnetic separation. It allows magnetic separation, a fast, efficient, high capacity and well-developed industrial technology, to be applied to the separation of materials that are otherwise non-magnetic. One application is in metal ion recovery from dilute effluents. Magnetic carrier technologies offer some advantages over other more conventional metal ion separa...

  15. The plant mitochondrial carrier family: functional and evolutionary aspects

    OpenAIRE

    Ilka eHaferkamp; Stephan eSchmitz-Esser

    2012-01-01

    Mitochondria play a key role in respiration and energy production and are involved in multiple eukaryotic but also in several plant specific metabolic pathways. Solute carriers in the inner mitochondrial membrane connect the internal metabolism with that of the surrounding cell. Because of their common basic structure, these transport proteins affiliate to the mitochondrial carrier family (MCF). Generally, MCF proteins consist of six membrane-spanning helices, exhibit typical conserved domain...

  16. Decision feedback loop for tracking a polyphase modulated carrier

    Science.gov (United States)

    Simon, M. K. (Inventor)

    1974-01-01

    A multiple phase modulated carrier tracking loop for use in a frequency shift keying system is described in which carrier tracking efficiency is improved by making use of the decision signals made on the data phase transmitted in each T-second interval. The decision signal is used to produce a pair of decision-feedback quadrature signals for enhancing the loop's performance in developing a loop phase error signal.

  17. Effects of copper on the carrier dynamics in black silicon

    DEFF Research Database (Denmark)

    Porte, Henrik; Turchinovich, Dmitry; Persheyev, S.;

    2011-01-01

    Black silicon is produced by laser annealing of a-Si:H films. We show that by adding a thin Cu film on top of the a-Si:H film before laser annealing, the carrier lifetime can be significantly reduced.......Black silicon is produced by laser annealing of a-Si:H films. We show that by adding a thin Cu film on top of the a-Si:H film before laser annealing, the carrier lifetime can be significantly reduced....

  18. Hot-carrier reliability in OPTVLD-LDMOS

    Institute of Scientific and Technical Information of China (English)

    Cheng Junji; Chen Xingbi

    2012-01-01

    An improved structure that eliminates hot-carrier effects (HCE) in optimum variation lateral doping (OPTVLD) LDMOS is proposed.A formula is proposed showing that the surface electric field intensity of the conventional structure is strong enough to make a hot-carrier injected into oxide.However,the proposed structure effectively reduces the maximum surface electric field from 268 to 100 kV/cm and can be realized without changing any process,and thereby reduces HCE significantly.

  19. Subtle changes among presymptomatic carriers of the Huntington's disease gene

    OpenAIRE

    Kirkwood, S.; Siemers, E; Hodes, M.; Conneally, P; Christian, J.; Foroud, T

    2000-01-01

    OBJECTIVES—To compare the neurological and psychometric characteristics of presymptomatic gene carriers and non-gene carriers who are at risk for developing Huntington's disease so as to characterise early signs of disease and to identify markers of neurological function that could be used to assess the impact of experimental therapies on the progression of disease, even among those who are clinically presymptomatic.
METHODS—A sample of people at risk for Huntington's dis...

  20. Test probe for surface mounted leadless chip carrier

    Science.gov (United States)

    Meyer, Kerry L.; Topolewski, John

    1989-05-23

    A test probe for a surface mounted leadless chip carrier is disclosed. The probed includes specially designed connector pins which allow size reductions in the probe. A thermoplastic housing provides spring action to ensure good mechanical and electrical contact between the pins and the contact strips of a leadless chip carrier. Other features include flexible wires molded into the housing and two different types of pins alternately placed in the housing. These features allow fabrication of a smaller and simpler test probe.