WorldWideScience

Sample records for bimetals

  1. CALCULATION OF BIMETAL PLATE BENDING FORCE OF A GLOW DISCHARGE STARTER

    OpenAIRE

    Akimov, V.; Mukha, L.

    2005-01-01

    Calculation techniques of bending power of bimetal plate electrode causing its displacement in the direction of the electrode of glow discharge starter have been represented. Calculation of bimetal electrode displacement has been conducted in correspondence with the chosen scheme.

  2. Quality of bimetal Al-Cu joint after explosive cladding

    Directory of Open Access Journals (Sweden)

    S. Berski

    2007-05-01

    Full Text Available Purpose: An analysis of quality of bimetallic joint between aluminium and copper layers of billet for extrusion process is the subject of the work.Design/methodology/approach: For preparing the quality analysis of particular layer of bimetal, the shearing test were done. During the tests the maximal stress for particular sets of the bimetal was established. For chosen cases the metallographic research of Al-Cu joint were done.Findings: The geometry of the cylindrical set and explosive cladding process parameters which allow to obtain the cylindrical bimetallic billets without cracks and delaminations and also with uniform cladded layer along and across the billet.Research limitations/implications: The analysis is concerning the explosive joint of pure aluminium Al995 and electrolytic copper M1E 99,97 in cylindrical sets. In the future research the analysis of this kind of joints after direct extrusion process is planning.Practical implications: The analysis could be helpful for more effective designing of the bimetal billets through the explosive cladding process and next for the plastic working processes.Originality/value: During the extrusion process with high value of extrusion ratio the delamination of the billet layers especially on the boundary of the layers is observed, this fact causes that joint after the metal working processes has lower strength even than components of the bimetal billet. So very important task is establishing the geometry set and explosive parameters to obtain the best quality of the joint.

  3. Theoretical and Experimental Study of Bimetal-Pipe Hydroforming

    OpenAIRE

    Dezhi, Zeng; Kuanhai, Deng; Taihe, Shi; Yuanhua, Lin; Hongjun, Zhu; Tianlei, Li; Yongxing, Sun

    2014-01-01

    The corrosion of oil country tubular goods (OCTG) gets more and more serious especially in the acidic environment. So, it is very important to develop a perfect anticorrosion technology for exploring sour oil and gas fields economically and safely. Analysis indicates that the bimetal-pipe (BP) which consists of the base layer of low carbon steel and a corrosion resistant alloy (CRA) cladding layer is an economic and reliable anticorrosion technology and has broad application prospects in the ...

  4. Abatement of Azo Dye from Wastewater Using Bimetal-Chitosan

    Directory of Open Access Journals (Sweden)

    Ghorban Asgari

    2013-01-01

    Full Text Available We introduce a new adsorbent, bimetallic chitosan particle (BCP that is successfully synthesized and applied to remove the orange II dye from wastewater. The effects of pH, BCP quantity, and contact time are initially verified on the basis of the percentage of orange II removed from the wastewater. Experimental data reveal that the Cu/Mg bimetal and chitosan have a synergistic effect on the adsorption process of the adsorbate, where the dye adsorption by Cu/Mg bimetal, chitosan alone, and bimetal-chitosan is 10, 49, and 99.5%, respectively. The time required for the complete decolorization of orange II by 1 mg/L of BCP is 10 min. The Langmuir model is the best fit for the experimental data, which attains a maximum adsorption capacity of 384.6 mg/g. The consideration of the kinetic behavior indicates that the adsorption of orange II onto the BCP fits best with the pseudo-second-order and Elovich models. Further, the simulated azo dye wastewater can be effectively treated using a relatively low quantity of the adsorbent, 1 mg/L, within a short reaction time of 20 min. Overall, the use of BCP can be considered a promising method for eliminating the azo dye from wastewater effectively.

  5. Static and cyclic strength of bimetal prepared by surfacing method

    International Nuclear Information System (INIS)

    The effect is studied of the magnitude of the operating repeated static load and the number of changes in heat conditions upon the development of diffusion bimetal interlayers (low-carbon unalloyed structural steel plus austenitic highalloy steel). When the material is heated at elevated temperatures under stress and when the temperature and stress change cyclically, the diffusion processes are accelerated. Then in the basic metal there appear decarbonization zones, whereas in the filler metal, carburization zones. The statical strenght is minium in the basic metal, the cyclical strength, in the diffusion zone metal

  6. Semi-flexible bimetal-based thermal energy harvesters

    International Nuclear Information System (INIS)

    This paper introduces a new semi-flexible device able to turn thermal gradients into electricity by using a curved bimetal coupled to an electret-based converter. In fact, a two-step conversion is carried out: (i) a curved bimetal turns the thermal gradient into a mechanical oscillation that is then (ii) converted into electricity thanks to an electrostatic converter using electrets in Teflon®. The semi-flexible and low-cost design of these new energy converters pave the way to mass production over large areas of thermal energy harvesters. Raw output powers up to 13.46 μW per device were reached on a hot source at 60 °C with forced convection. Then, a DC-to-DC flyback converter has been sized to turn the energy harvesters’ raw output powers into a viable supply source for an electronic circuit (DC-3 V). At the end, 10 μW of directly usable output power were reached with 3 devices, which is compatible with wireless sensor network powering applications. (paper)

  7. Semi-flexible bimetal-based thermal energy harvesters

    CERN Document Server

    Boisseau, S; Monfray, S; Puscasu, O; Skotnicki, T; 10.1088/0964-1726/22/2/025021

    2013-01-01

    This paper introduces a new semi-flexible device able to turn thermal gradients into electricity by using a curved bimetal coupled to an electret-based converter. In fact, a two-steps conversion is carried out: (i) a curved bimetal turns the thermal gradient into a mechanical oscillation that is then (ii) converted into electricity thanks to an electrostatic converter using electrets in Teflon (r). The semi-flexible and low cost design of these new energy converters pave the way to mass production over large areas of thermal energy harvesters. Raw output powers up to 13.46uW per device were reached on a hot source at 60{\\deg}C and forced convection. Then, a DC-to-DC flyback converter has been sized to turn the energy harvesters' raw output powers into a viable supply source for an electronic circuit (DC-3V). At the end, 10uW of directly usable output power were reached with 3 devices, which is compatible with Wireless Sensor Networks powering applications. Please cite as : S Boisseau et al 2013 Smart Mater. S...

  8. Structural integrity of welded bi-metallic components (BIMET) - Task Group 5 'Analysis'. Prediction by EAM and FEA

    International Nuclear Information System (INIS)

    Investigations in the EU BIMET project focused on two pipe segments of ferritic and austenitic steel with a special weld in between which is characterised by a multiphase transition with strongly diverging characteristics (strength mis-matching). The BIMET project is described, and some of the findings of Task Group 5 'Analysis' are presented which are based on EAM and FEA

  9. Second-harmonic generation from bimetal composites doped with metal nanoparticles

    Science.gov (United States)

    Daneshfar, Nader

    2016-05-01

    In the present paper, we study the nonlinear optical response of the bimetal composites doped with metal nanoparticles in the framework of nonlinear Mie theory combined with the Maxwell-Garnett model. We concentrate on the second-order harmonic generation from bimetal nanocomposites including silver and gold particles, since sometimes the nonlinear optical response is sensitive to the more accurate of material structure than linear optical response. We show that optical second harmonic generation is strongly sensitive to temperature as an environmental parameter, interparticle plasmon coupling between Au and Ag nanoparticles (the filling factor of inclusions), the particle size and the surrounding medium. However, this work shows good potential of bimetal composites for nonlinear optics at the nanoscale.

  10. Modeling of the thermo-mechanical efficiency of the bimetal strip heat engines

    International Nuclear Information System (INIS)

    This paper presents a theoretical demonstration of the bimetal strip heat engine working, based on the study of the thermo-mechanical instability of the pre-buckled bimetallic beams. Starting from the Euler buckling equation, this paper describes the bimetal strips like classical but non-linear thermodynamic systems, and gives the bistability criterion of such beams. Studying the thermodynamic potentials of these beams helps to evaluate the release of the kinetic energy happening during the beam snap-through, to give the Maxwell relations between each partial derivative of the thermodynamic potentials and to show that the thermal snap-through is a first-order transition according to the Ehrenfest theory. The model is then used to draw the temperature-entropy cycle of the bimetal heat engines and to evaluate the performances of these harvesters (available mechanical energy and thermodynamic cycle efficiency)

  11. Theoretical and Experimental Study of Bimetal-Pipe Hydroforming.

    Science.gov (United States)

    Dezhi, Zeng; Kuanhai, Deng; Taihe, Shi; Yuanhua, Lin; Hongjun, Zhu; Tianlei, Li; Yongxing, Sun

    2014-12-01

    The corrosion of oil country tubular goods (OCTG) gets more and more serious especially in the acidic environment. So, it is very important to develop a perfect anticorrosion technology for exploring sour oil and gas fields economically and safely. Analysis indicates that the bimetal-pipe (BP) which consists of the base layer of low carbon steel and a corrosion resistant alloy (CRA) cladding layer is an economic and reliable anticorrosion technology and has broad application prospects in the transportation of acid medium. However, theoretical study of hydraulic expansion mechanism for BP is not enough. In this paper, the deformation compatibility condition of BP was obtained by studying the deformation rule of the (CRA) liner and the outer pipe of carbon steel in the forming process; the mechanical model which can compute the hydroforming pressure of BP has been established based on the nonlinear kinematic hardening characteristics of material; furthermore, based on the stress strain curve of inner pipe simultaneously, the calculation method of the plastic hardening stress has been proposed. Thus, the accurate method for computing the forming pressure was obtained. The experimental data show that results are consistent with results of the proposed model. It indicates that the model can be used to provide theoretical guidance for the design and production as well as use of BP. PMID:25349461

  12. Selenide isotope generators for the Galileo Mission: SIG hermetic bimetal weld transition joint

    International Nuclear Information System (INIS)

    The successful development of the commercial 6061-T651/Silver/304L explosive clad plate material as a bimetal weld transition joint material, as described herein, satisfies all SIG Galileo design requirements for hermetic weld attachment of stainless steel subassemblies to aluminum alloy generator housing or end cover structures. The application of this type weld transition joint to the hermetic attachment of stainless steel shell connectors is well-developed and tested. Based on on-going life tests of stainless steel receptacle/bimetal ring attachment assemblies and metallurgical characterization studies of this transition joint material, it appears evident that this transition joint material has more than adequate capability to meet the 250 to 3000F and 50,000 hr. design life of the SIG/Galileo mission. Its extended life temperture capability may well approach 350 to 4000F

  13. Degradation of high energetic and insensitive munitions compounds by Fe/Cu bimetal reduction

    International Nuclear Information System (INIS)

    Highlights: ► Bimetal iron–copper particles are highly effective for treating waste streams containing energetic components such as RDX, TNT, HMX, NTO, and DNAN. ► First report ever on the degradation of NTO and DNAN from real industrial wastewater using bimetallic particles. ► Assessment of pH effect on NTO degradation by bimetal. ► Nitroaromatic structure of TNT exhibits a high preference for the metal surface and faster degradation. - Abstract: A reductive technology based on a completely mixed two-phase reactor (bimetallic particles and aqueous stream) was developed for the treatment of aqueous effluents contaminated with nitramines and nitro-substituted energetic materials. Experimental degradation studies were performed using solutions of three high energetics (RDX, HMX, TNT) and three insensitive-munitions components (NTO, NQ, DNAN). The study shows that, on laboratory scale, these energetic compounds are easily degraded in solution by suspensions of bimetallic particles (Fe/Ni and Fe/Cu) prepared by electro-less deposition. The type of bimetal pair (Fe/Cu or Fe/Ni) does not appear to affect the degradation kinetics of RDX, HMX, and TNT. The degradation of all components followed apparent first-order kinetics. The half-lives of all compounds except NTO were under 10 min. Additional parameters affecting the degradation processes were solids loading and initial pH.

  14. Interrelation between acoustic emission parameters and fracture mode of bimetals at 77K

    International Nuclear Information System (INIS)

    Studied are the singularities of acoustic emission during the fracture of industrial bimetals at a boiling temperature of liquid nitrogen (77K), as well as determined is the possibility of estimation of the fracture mode in bimetallic materials (St. 3+Kh18N9T, St. 3+0Kh13) by the acoustic emission method. It is shown that the registration of accoustic emission in combination with the spectral analysis permits to determine rather accurately the micromechanism and time brittle fracture, as well as a change of the fracture mechanism while crack propagation

  15. Amphiphilic hollow porous shell encapsulated Au@Pd bimetal nanoparticles for aerobic oxidation of alcohols in water

    KAUST Repository

    Zou, Houbing

    2015-01-01

    © The Royal Society of Chemistry 2015. This work describes the design, synthesis and analysis of an amphiphilic hollow mesoporous shell encapsulating catalytically active Au@Pd bimetal nanoparticles. The particles exhibited excellent catalytic activity and stability in the aerobic oxidation of primary and secondary alcohols to their corresponding aldehydes or ketones in water when using air as an oxidizing agent under atmospheric pressure.

  16. High Cr white cast iron/carbon steel bimetal liner by lost foam casting with liquid-liquid composite process

    Directory of Open Access Journals (Sweden)

    Xiao Xiaofeng

    2012-05-01

    Full Text Available Liners in wet ball mill for mineral processing industry must bear abrasive wear and corrosive wear, and consequently, the service life of the liner made from traditional materials, such as Hadfield steel and alloyed steels, is typically less than ten months. Bimetal liner, made from high Cr white cast iron and carbon steel, has been successfully developed by using liquid-liquid composite lost foam casting process. The microstructure and interface of the composite were analyzed using optical microscope, SEM, EDX and XRD. Micrographs indicate that the boundary of bimetal combination regions is staggered like dogtooth, two liquid metals are not mixed, and the interface presents excellent metallurgical bonding state. After heat treatment, the composite liner specimens have shown excellent properties, including hardness > 61 HRC, fracture toughness αk >16.5 J·cm-2 and bending strength >1,600 MPa. Wear comparison was made between the bimetal composite liner and alloyed steel liner in an industrial hematite ball mill of WISCO, and the results of eight-month test in wet grinding environment have proved that the service life of the bimetal composite liner is three times as long as that of the alloyed steel liner.

  17. Bimetal Ga-Sn catalyzed growth for the novel morphologies of silicon oxide nanowires

    International Nuclear Information System (INIS)

    The large size, low melting point bimetal Ga-Sn can be used as an effective catalyst for the large-scale growth of highly aligned, closely packed silicon oxide nanowires bunches. The experimental results show that the silicon oxide nanowires tend to grow bunch by bunch. For each bunch, numerous nanowires simultaneously nucleate, grow at nearly the same rate and direction, and simultaneously stop growing. The prickly spheres, whisk-like, echinus-like, hedgehog-like, and dandelions-like silicon oxide nanowires were formed under different atomic ratio of Ga and Sn in the alloy ball. A growth model was proposed. The experimental results further expand the growth mechanism of the quasi-one-dimensional nanostructures to a broader range

  18. Experimental data for synthesis of bi-metalized chitosan particle for attenuating of an azo dye from wastewater.

    Science.gov (United States)

    Hajivandi, Abdollah; Farjadfard, Sima; Ramavandi, Bahman; Akbarzadeh, Samad

    2016-06-01

    In this data article, we introduce data acquired from new adsorbent, bi-metalized chitosan particle that is successfully synthesized and applied to remove the orange II dye, an azo dye, from textile wastewater. The adsorbent was meso- and macro-porous material with BET surface area of 12.69 m(2)/g and pHzpc 6.6. The simulated textile-wastewater can be significantly treated using a relatively low quantity of the adsorbent. Overall, the use of bi-metalized chitosan particle can be considered a promising method for eliminating the azo dye from wastewater effectively. Accordingly, these data will be useful for decolorizing of azo dyes from textile wastewater. PMID:26955651

  19. Fabrication of plain carbon steel/high chromium white cast iron bimetal by a liquid-solid composite casting process

    Institute of Scientific and Technical Information of China (English)

    V Javaheri; H Rastegari; M Naseri

    2015-01-01

    High-chromium white cast iron (HCWCI) is one of the most widely used engineering materials in the mining and cement indus-tries. However, in some components, such as the pulverizer plates of ash mills, the poor machinability of HCWCI creates difficulties. The bimetal casting technique is a suitable method for improving the machinability of HCWCI by joining an easily machined layer of plain car-bon steel (PCS) to its hard part. In this study, the possibility of PCS/HCWCI bimetal casting was investigated using sand casting. The inves-tigation was conducted by optical and electron microscopy and non-destructive, impact toughness, and tensile tests. The hardness and chemical composition profiles on both sides of the interface were plotted in this study. The results indicated that a conventional and low-cost casting technique could be a reliable method for producing PCS/HCWCI bimetal. The interfacial microstructure comprised two distinct lay-ers:a very fine, partially spheroidized pearlite layer and a coarse full pearlite layer. Moreover, characterization of the microstructure revealed that the interface was free of defects.

  20. Preparation of a Bimetal Using Mechanical Alloying for Environmental or Industrial Use

    Science.gov (United States)

    Quinn, Jacqueline; Geiger, Cherie; Clausen, Christian

    2013-01-01

    Following the 1976 Toxic Substances Control Act ban on their manufacture, PCBs remain an environmental threat. PCBs are known to bio-accumulate and concentrate in fatty tissues. Further complications arise from the potential for contamination of commercial mixtures with other more toxic chlorinated compounds such as polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Until recently, only one option was available for the treatment of PCB-contaminated materials: incineration. This may prove to be more detrimental to the environment than the PCBs themselves due to the potential for formation of PCDDs. Metals have been used for the past ten years for the remediation of halogenated solvents and other contaminants in the environment; however, zero-valent metals alone do not possess the activity required to dehalogenate PCBs. Palladium has been shown to act as an excellent catalyst for the dechlorination of PCBs with active metals. This invention is a method for the production of a palladium/magnesium bimetal capable of dechlorinating PCBs using mechanical milling/mechanical alloying. Other base metals and catalysts may also be alloyed together (e.g., nickel or zinc) to create a similarly functioning catalyst system. Several bimetal catalyst systems currently can be used for processes such as hydrogen peroxide synthesis, oxidation of ethane, selective oxidation, hydrogenation, and production of syngas for further conversion to clean fuels. The processes for making these bimetal catalysts often involve vapor deposition. This technology provides an alternative to vapor deposition that may provide equally active catalysts. A hydrogenation catalyst including a base material coated with a catalytic metal is made using mechanical milling techniques. The hydrogenation catalysts are used as an excellent catalyst for the dehalogenation of contaminated compounds and the remediation of other industrial compounds. The mechanical milling technique is

  1. A Fiber Bragg Grating—Bimetal Temperature Sensor for Solar Panel Inverters

    Science.gov (United States)

    Ismail, Mohd Afiq; Tamchek, Nizam; Hassan, Muhammad Rosdi Abu; Dambul, Katrina D.; Selvaraj, Jeyrai; Rahim, Nasrudin Abd; Sandoghchi, Reza; Adikan, Faisal Rafiq Mahamd

    2011-01-01

    This paper reports the design, characterization and implementation of a Fiber Bragg Grating (FBG)-based temperature sensor for an Insulted-Gate Bipolar Transistor (IGBT) in a solar panel inverter. The FBG is bonded to the higher Coefficient of Thermal Expansion (CTE) side of a bimetallic strip to increase its sensitivity. Characterization results show a linear relationship between increasing temperature and the wavelength shift. It is found that the sensitivity of the sensor can be categorized into three characterization temperature regions between 26 °C and 90 °C. The region from 41 °C to 90 °C shows the highest sensitivity, with a value of 14 pm/°C. A new empirical model that considers both temperature and strain effects has been developed for the sensor. Finally, the FBG-bimetal temperature sensor is placed in a solar panel inverter and results confirm that it can be used for real-time monitoring of the IGBT temperature. PMID:22164098

  2. A fiber Bragg grating--bimetal temperature sensor for solar panel inverters.

    Science.gov (United States)

    Ismail, Mohd Afiq; Tamchek, Nizam; Hassan, Muhammad Rosdi Abu; Dambul, Katrina D; Selvaraj, Jeyrai; Rahim, Nasrudin Abd; Sandoghchi, Reza; Adikan, Faisal Rafiq Mahamd

    2011-01-01

    This paper reports the design, characterization and implementation of a fiber Bragg grating (FBG)-based temperature sensor for an insulted-gate Bipolar transistor (IGBT) in a solar panel inverter. The FBG is bonded to the higher coefficient of thermal expansion (CTE) side of a bimetallic strip to increase its sensitivity. Characterization results show a linear relationship between increasing temperature and the wavelength shift. It is found that the sensitivity of the sensor can be categorized into three characterization temperature regions between 26 °C and 90 °C. The region from 41 °C to 90 °C shows the highest sensitivity, with a value of 14 pm/°C. A new empirical model that considers both temperature and strain effects has been developed for the sensor. Finally, the FBG-bimetal temperature sensor is placed in a solar panel inverter and results confirm that it can be used for real-time monitoring of the IGBT temperature. PMID:22164098

  3. A Fiber Bragg Grating—Bimetal Temperature Sensor for Solar Panel Inverters

    Directory of Open Access Journals (Sweden)

    Mohd Afiq Ismail

    2011-09-01

    Full Text Available This paper reports the design, characterization and implementation of a Fiber Bragg Grating (FBG-based temperature sensor for an Insulted-Gate Bipolar Transistor (IGBT in a solar panel inverter. The FBG is bonded to the higher Coefficient of Thermal Expansion (CTE side of a bimetallic strip to increase its sensitivity. Characterization results show a linear relationship between increasing temperature and the wavelength shift. It is found that the sensitivity of the sensor can be categorized into three characterization temperature regions between 26 °C and 90 °C. The region from 41 °C to 90 °C shows the highest sensitivity, with a value of 14 pm/°C. A new empirical model that considers both temperature and strain effects has been developed for the sensor. Finally, the FBG-bimetal temperature sensor is placed in a solar panel inverter and results confirm that it can be used for real-time monitoring of the IGBT temperature.

  4. Isotherm studies for determination of removal capacity of bi-metal (Ni and Cr) ions by aspergillus niger

    International Nuclear Information System (INIS)

    Pakistan is among the developing countries where there is a need to establish new industries to meet the demands of a growing population. This has led to industrial setup in various sectors, without proper planning and consideration for treatment of contamination, leading to disposal of untreated wastewater into nearby land and water bodies. This study was planned to investigate an indigenous Aspergillus niger for development of biosorbent for the removal of metal ions. The Aspergillus isolate's Ni and Cr removal efficiency was determined in batch mode over various pH (4.0-10.0) and temperature (25-40 deg. C) as single as well as bimetal ions. Using a single metal ion, maximum biosorption potential was obtained at pH 5.0-6.0 and 30-35 deg. C for both ions. On the other hand, Ni removal was reduced in the presence of Cr, while Ni removal influenced Cr removal with an increase showing maximum removal at an initial adsorbate concentration of 50mg/L, pH 6.0 and 35 deg. C. Effect of presence of bimetal in a solution on biosorption potential of Aspergillus niger was predicted by using equilibrium modeling. Adsorption trends for both nickel (R2 0.9916) and chromium (R2 0.8548) followed Langmuir isotherm in single metal removal system, but under bimetal condition chromium adsorption fitted better to Freundlich model and that of nickel followed Temkin isotherm, suggesting considerable change in behavior and interaction between biosorbent and metal ions. Therefore, we concluded that Aspergillus niger a viable strain for development of a biosorbent for removal of a mixture of metal ions. (author)

  5. Simultaneous treatment of chlorinated organics and removal of metals and radionuclides with bimetals and complexing acids - application to surfactant solutions

    International Nuclear Information System (INIS)

    Currently available methods for separation and treatment of radioactive mixed waste are typically energy-intensive, and often require high temperatures. Passive methods that operate at ambient temperatures are needed. The purpose of this task is to develop bimetallic substrates, using a base metal such as iron and a promoter metal such as palladium (Pd), to provide a passive, low-energy solution to a substantial portion of DOE's mixed-waste problem. This technology consists of a porous medium that can simultaneously dechlorinate hazardous organics such as TCE and polychlorinated biphenyls (PCBs) at the same time that it removes metallic and hazardous wastes from a solvent/surfactant solution. The porous medium consists of a bimetallic substrate such as palladized iron (Pd/Fe). Palladium is readily chemically plated on iron and preliminary studies suggest that only 0.05 to 0.1% Pd is needed for an efficient reaction. Thus, the cost of the material is reasonable especially is it is long-lived or can be regenerated. Field implementation would consist of the passage of a surfactant-laden, mixed waste through a column or bed of the bimetallic substrate. The organic component of this mixed waste may contain semivolatile compounds such as PCBs or pesticides and herbicides. The bimetal simultaneously removes radionuclides and metals and degrades halogenated hydrocarbons. Virtually any concentration can be treated. Following reaction of the bimetal with the waste stream, the resulting effluent will consist of an uncontaminated aqueous solution of surfactant or solvent that can be reused. The bimetal would then be rinsed with a dilute mineral acid or a mild complexing acid (e.g., oxalic or citric acid) to regenerate the surface and to remove sorbed metals and non-hazardous organic residue. The latter effluent would be low-level radioactive waste in some cases, but it would now be much easier to manage and be of a lower volume than the original mixed waste

  6. Simultaneous treatment of chlorinated organics and removal of metals and radionuclides with bimetals and complexing acids - application to surfactant solutions

    Energy Technology Data Exchange (ETDEWEB)

    Korte, N.E.; Gu, B. [Oak Ridge National Lab., TN (United States)

    1997-10-01

    Currently available methods for separation and treatment of radioactive mixed waste are typically energy-intensive, and often require high temperatures. Passive methods that operate at ambient temperatures are needed. The purpose of this task is to develop bimetallic substrates, using a base metal such as iron and a promoter metal such as palladium (Pd), to provide a passive, low-energy solution to a substantial portion of DOE`s mixed-waste problem. This technology consists of a porous medium that can simultaneously dechlorinate hazardous organics such as TCE and polychlorinated biphenyls (PCBs) at the same time that it removes metallic and hazardous wastes from a solvent/surfactant solution. The porous medium consists of a bimetallic substrate such as palladized iron (Pd/Fe). Palladium is readily chemically plated on iron and preliminary studies suggest that only 0.05 to 0.1% Pd is needed for an efficient reaction. Thus, the cost of the material is reasonable especially is it is long-lived or can be regenerated. Field implementation would consist of the passage of a surfactant-laden, mixed waste through a column or bed of the bimetallic substrate. The organic component of this mixed waste may contain semivolatile compounds such as PCBs or pesticides and herbicides. The bimetal simultaneously removes radionuclides and metals and degrades halogenated hydrocarbons. Virtually any concentration can be treated. Following reaction of the bimetal with the waste stream, the resulting effluent will consist of an uncontaminated aqueous solution of surfactant or solvent that can be reused. The bimetal would then be rinsed with a dilute mineral acid or a mild complexing acid (e.g., oxalic or citric acid) to regenerate the surface and to remove sorbed metals and non-hazardous organic residue. The latter effluent would be low-level radioactive waste in some cases, but it would now be much easier to manage and be of a lower volume than the original mixed waste.

  7. Copper-iron bimetal modified PAN fiber complexes as novel heterogeneous Fenton catalysts for degradation of organic dye under visible light irradiation

    International Nuclear Information System (INIS)

    Graphical abstract: Cu-Fe bimetal amidoximated PAN fiber complex (Cu-Fe-AO-PAN) showed the better catalytic ability and stability under visible irradiation as a novel heterogeneous Fenton catalyst than Fe amidoximated PAN fiber complex (Fe-AO-PAN). - Abstract: A series of Cu-Fe bimetal amidoximated polyacrylonitrile (PAN) fiber complexes with different molar ratios of Cu2+ to Fe3+ ions was prepared using a simple exhaustion method, and characterized using FTIR, DRS and XPS, respectively. Then they were tested as the heterogeneous Fenton catalysts for Rhodamine B degradation with H2O2 in the dark and under visible light irradiation. The results indicated that Cu-Fe bimetal amidoximated PAN fiber complexes could more effectively catalyze the dye degradation in water than Fe amidoximated PAN fiber complex, especially in the dark. And introduction of Cu2+ ions significantly increased their catalytic performance. 0.56 was the optimum molar ratio of Cu2+ to Fe3+ ions to achieve the best catalytic activity and stability. This was mainly due to the synergetic effect in the bimetal complexes. Visible light irradiation improved the catalytic activity of the complexes, especially with a low molar ratio of Cu2+ to Fe3+ ions.

  8. Numerical Simulation on the Die Filling Process of the Thixo-Forging of Al-7 wt pct Si/Al-22 wt pct Si Bimetal Composite

    Science.gov (United States)

    Wang, Guangxu; Huang, Honghua; Yang, Zhao; Shi, Xiaocheng; He, Xiaolong

    2015-10-01

    A bimetal semi-solid fluid has more complicated flow behaviors than a normal semi-solid fluid during thixo-forging. In order to clarify the detailed properties of the bimetal thixo-forging, the effects of billet temperatures and frictions on flow behaviors of the Al-7 wt pct Si/Al-22 wt pct Si bimetal thixo-forging were investigated by commercial software DEFORM-3D. The simulation results show that shear force was unable to be transferred from the upper billet on the drop die side to the bottom billet on the counter die side efficiently in the initial stage of die filling. Only when the upper billet severely deformed, did the shear force deform the bottom billet. A stiffer upper billet can enhance the efficiency of shear force transfer. The processing temperature, the relative stiffness between the upper billet and bottom billet, and frictions between dies and billets, as well as friction between billets, were important factors to control the interface outline of the bimetal parts. The experimental results are consistent with the simulation results.

  9. Investigation of cold rolling influence on the mechanical properties of explosive-welded Al/Cu bimetal

    International Nuclear Information System (INIS)

    In this study, effect of cold rolling process on the mechanical properties and bond strength of Al/Cu/Al bimetal has been investigated. The bimetal raw material has been fabricated by the explosive welding process. Then, cold rolling process was used to reduce the thickness of explosive-welded plates. The mechanical properties of the raw materials and cold-rolled samples were experimentally measured using the tensile, tensile-shearing and hardness tests along the thicknesses of the samples. Moreover, the fractography of the surfaces after the tensile tests were examined by the electron microscope (SEM). The obtained results show that, with the increase of thickness reduction, the ultimate strength and hardness have been increased significantly, while the elongation percentage has been diminished. Also, the bond strength confirms the relevant known standard criterion which is higher than the strength of the aluminum layers. Examination of the fracture surfaces reveal that, due to the brittle nature of the intermetallic compounds at the joining interface, the nucleation and propagation of micro cracks have been accelerated under tension and plastic deformation.

  10. SPICE modelling of a coupled piezoelectric-bimetal heat engine for autonomous Wireless Sensor Nodes (WSN) power supply

    International Nuclear Information System (INIS)

    This paper deals with an electrical modelling and optimization of a thermal energy harvester dedicated to power autonomous systems. Such devices based on bimetal strips and piezoceramics turn thermal gradients into electricity by a two-step conversion mechanism. This work focuses first on a demonstration of a ST-WSN (GreenNet demonstration platform) supplied by the harvester to validate, for the first time, the harvesters viability. That demonstration focuses attention on the need for an optimized power management circuit for piezoelectric generators able to reach output voltages up to 20 V. The work deals then with the proposal of an equivalent lumped element model of the piezoelectric transducer with its SPICE implementation to enable the optimization of a dedicated power management circuit based on the Pulsed Synchronous Charge Extractor (PSCE). Simulations using the SPICE model and the power management circuit lead to an increased extracted power by 144%

  11. SPICE modelling of a coupled piezoelectric-bimetal heat engine for autonomous Wireless Sensor Nodes (WSN) power supply

    Science.gov (United States)

    Boughaleb, J.; Monfray, S.; Vine, G.; Cottinet, P. J.; Arnaud, A.; Boisseau, S.; Duret, A. B.; Quenard, S.; Puscasu, O.; Maitre, C.; Trochut, S.; Hasbani, F.; Di Gilio, T.; Heinrich, V.; Urard, P.; Grasset, J. C.; Boeuf, F.; Guyomar, D.; Skotnicki, T.

    2014-11-01

    This paper deals with an electrical modelling and optimization of a thermal energy harvester dedicated to power autonomous systems. Such devices based on bimetal strips and piezoceramics turn thermal gradients into electricity by a two-step conversion mechanism. This work focuses first on a demonstration of a ST-WSN (GreenNet demonstration platform) supplied by the harvester to validate, for the first time, the harvesters viability. That demonstration focuses attention on the need for an optimized power management circuit for piezoelectric generators able to reach output voltages up to 20 V. The work deals then with the proposal of an equivalent lumped element model of the piezoelectric transducer with its SPICE implementation to enable the optimization of a dedicated power management circuit based on the Pulsed Synchronous Charge Extractor (PSCE). Simulations using the SPICE model and the power management circuit lead to an increased extracted power by 144%.

  12. Study on diffusion behavior and microstructural evolution of Al/Cu bimetal interface by synchrotron X-ray radiography

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tongmin, E-mail: tmwang@dlut.edu.cn [Key Laboratory of Materials Modification By Laser, Ion and Electron Beams (Ministry of Education), School of Material Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Cao, Fei; Zhou, Peng; Kang, Huijun; Chen, Zongning [Key Laboratory of Materials Modification By Laser, Ion and Electron Beams (Ministry of Education), School of Material Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Fu, Yanan; Xiao, Tiqiao [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204 (China); Huang, Wanxia; Yuan, Qingxi [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039 (China)

    2014-12-15

    Highlights: • Interface diffusion of Al/Cu bimetal was directly observed with X-ray radiography. • Three growth stages and four transition zones around Al/Cu interface were identified. • Concentration variations were analyzed through the gray level evolution of images. • Diffusion coefficients of Cu in Al were calculated from concentration variations. - Abstract: Synchrotron X-ray radiography was used to in situ study the interface diffusion behavior and microstructural evolution during the melting and solidification of Al/Cu bimetal. During the solidification, the dendritic growth around the interface is mainly dominated by the variation of Cu concentration and thermal field. Four transition zones of solute profile around the interface were identified to be I (α-Al), II (Al + Al{sub 2}Cu), III (Al{sub 2}Cu) and IV (AlCu, Al{sub 3}Cu{sub 4} and Al{sub 2}Cu{sub 3}), respectively. During the melting, the concentration variations of Al and Cu around the interface were quantitatively analyzed through the extraction of gray level from sequenced X-ray images. The diffusion coefficients of Cu in liquid Al were calculated from the known concentration variations by an inverse method based on Fick’s second law. The diffusion coefficients of Cu in Al were found to follow linear Arrhenius equation dependencies with the pre-exponential factor of 2.83 × 10{sup −5} m{sup 2} s{sup −1} and the activation energy of 96.0 kJ mol{sup −1} in a temperature range of 893–970 K.

  13. Application of Bi-metal Standard to Vertical Displacement Measurement in the Lechangxia Hydro-junction%双金属标在乐昌峡水利枢纽垂直位移观测的应用

    Institute of Scientific and Technical Information of China (English)

    朱信华

    2014-01-01

    Bimetallic standard is applying the differences in thermal expansion coefficients of aluminum and steel tube characteris -tics, absolute displacement measured perpendicular to the dam , or as hydrostatic level measurement , level base.Deformation moni-toring on its hinges , and decorated with bi-metal standard facilities as system base of vertical displacement can be overcome due to various reasons-error in the system.From the bi-metal standard observational aspects of composition , theory, application of bimetal mark in feilaixia lechang .%从双金属标的组成、原理、观测等方面,阐述双金属标在乐昌峡水利枢纽中用以量测坝体内部垂直绝对位移的应用。

  14. The Effect of Heat Treatment on the Properties of Zirconium - Carbon Steel Bimetal Produced By Explosion Welding

    Directory of Open Access Journals (Sweden)

    Prażmowski M.

    2014-10-01

    Full Text Available This paper assesses the effect of various values of detonation velocity on the quality of the bond zone, and thus the properties of bimetal zirconium (Zr 700 - steel (P355NL. The research was carried out for as-bonded welds, i.e. immediately following explosion welding. The results of shearing, peeling and tensile tests as well as macro-scale structural analyses were presented. In order to determine the changes in the value of strain hardening, the microhardness measurements across the interface were carried out. Based on the performed analyses it can be claimed that, depending on the applied technological settings of welding, most cases displayed wavy bond with highly diversified parameters of the wave. The changes observed with the detonation velocity are non-monotonic. High detonation velocities favored the formation of waves with large height and length and strongly affect the increase of the volume of brittle melted zones. Increased volume of the melted regions results in strong decrease of strength properties of the clad. The analysis of strength test results allows claiming that a small volume of melted regions in the bond considerably improves the strength of the bond.

  15. Mechanical Properties of Zirconium/Steel Bimetal Fabricated by Means of Explosive Welding at Varied Detonation Velocities

    Directory of Open Access Journals (Sweden)

    Prażmowski M.

    2014-10-01

    Full Text Available This paper assesses the effect of various values of detonation velocity on the quality of the bond zone, and thus the properties of bimetal zirconium (Zr 700 - steel (P355NL. The research was carried out for as-bonded welds, i.e. immediately following explosion welding. The results of shearing, peeling and tensile tests as well as macro-scale structural analyses were presented. In order to determine the changes in the value of strain hardening, the microhardness measurements across the interface were carried out. Based on the performed analyses it can be claimed that, depending on the applied technological settings of welding, most cases displayed wavy bond with highly diversified parameters of the wave. The changes observed with the detonation velocity are non-monotonic. High detonation velocities favored the formation of waves with large height and length and strongly affect the increase of the volume of brittle melted zones. Increased volume of the melted regions results in strong decrease of strength properties of the clad. The analysis of strength test results allows claiming that a small volume of melted regions in the bond considerably improves the strength of the bond.

  16. Telas de carbón como soporte de catalizadores bimetálicos Pt-Sn: efecto promotor del TiO2

    OpenAIRE

    Huidobro Pahissa, Ana

    2003-01-01

    Este trabajo se centra en el estudio de las interacciones entre dos fases metálicas, el platino y el estaño, soportados sobre dos materiales que establecen distintas interacciones con las fases metálicas soportadas sobre ellos. Se eligió el Pt porque es un metal noble que se utiliza como catalizador en numerosas reacciones catalíticas. El estaño puede actuar como promotor del platino de manera que los sistemas bimetálicos basados en Pt-Sn han sido ampliamente investigados debido a sus b...

  17. Hidrodesulfuración de una carga real (GPV) con fosfuros bimetálicos soportados en sílica

    OpenAIRE

    L. R. Elliard Pérez; J. G. Sandoval-Robles; J. M. Domínguez-Esquivel; R. García-Alamilla; J. A. Melo-Banda; J. Ancheyta

    2006-01-01

    Se sintetizaron fosfuros bimetálicos de Co-Mo y Co-W soportados en SiO2 con 6 y 20% peso de metales, mediante impregnaciones sucesivas, y posteriormente reducidos a temperatura programada. Se obtuvieron las fases deseadas de CoMoP/SiO2 y CoWP/SiO2 de acuerdo a los patrones de difracción de rayos X reportados en la literatura. Se prepararon materiales mesoporosos con área específica alta, teniendo mayor diámetro de poro los materiales de cobalto-molibdeno, promoviendo así una mayor activida...

  18. Direct Synthesis of Dimethyl Carbonate from CO2 and CH3OH Using 0.4 nm Molecular Sieve Supported Cu-Ni Bimetal Catalyst

    Institute of Scientific and Technical Information of China (English)

    陈惠玲; 王栓紧; 肖敏; 韩冬梅; 卢一新; 孟跃中

    2012-01-01

    The 0.4 nm molecular sieve supported Cu-Ni bimetal catalysts for direct synthesis of dimethyl carbonate (DMC) from CO 2 and CH 3 OH were prepared and investigated. The synthesized catalysts were fully characterized by BET, XRD (X-ray diffraction), TPR (temperature programmed reduction), IR (infra-red adsorption), NH 3-TPD (temperature programmed desorption) and CO 2-TPD (temperature programmed desorption) techniques. The results showed that the surface area of catalysts decreased with increasing metal content, and the metals as well as Cu-Ni alloy co-existed on the reduced catalyst surface. There existed interaction between metal and carrier, and moreover, metal particles affected obviously the acidity and basicity of carrier. The large amount of basic sites facilitated the activation of methanol to methoxyl species and their subsequent reaction with activated carbon dioxide. The catalysts were evaluated in a continuous tubular fixed-bed micro-gaseous reactor and the catalyst with bimetal loading of 20% (by mass) had best catalytic activities. Under the conditions of 393 K, 1.1 MPa, 5 h and gas space velocity of 510 h 1 , the selectivity and yield of DMC were higher than 86.0 % and 5.0 %, respectively.

  19. Three-Dimensional Bimetal-Graphene-Semiconductor Coaxial Nanowire Arrays to Harness Charge Flow for the Photochemical Reduction of Carbon Dioxide.

    Science.gov (United States)

    Hou, Jungang; Cheng, Huijie; Takeda, Osamu; Zhu, Hongmin

    2015-07-13

    The photochemical conversion of carbon dioxide provides a straightforward and effective strategy for the highly efficient production of solar fuels with high solar-light utilization efficiency. However, the high recombination rate of photoexcited electron-hole (e-h) pairs and the poor photostability have greatly limited their practical applications. Herein, a practical strategy is proposed to facilitate the separation of e-h pairs and enhance the photostability in a semiconductor by the use of a Schottky junction in a bimetal-graphene-semiconductor stack array. Importantly, Au-Cu nanoalloys (ca. 3 nm) supported on a 3D ultrathin graphene shell encapsulating a p-type Cu2O coaxial nanowire array promotes the stable photochemical reduction of CO2 to methanol by the synergetic catalytic effect of interfacial modulation and charge-transfer channel design. This work provides a promising lead for the development of practical catalysts for sustainable fuel synthesis. PMID:26068934

  20. Effect of volume ratio of liquid to solid on the interfacial microstructure and mechanical properties of high chromium cast iron and medium carbon steel bimetal

    International Nuclear Information System (INIS)

    Highlights: → Volume ratio of liquid to solid affects significantly the interfacial microstructure. → Elemental diffusion activity is increased by increasing volume ratio. → Mechanical property is improved by increasing volume ratio. - Abstract: The high chromium cast iron and medium carbon steel bimetal was fabricated by liquid-solid casting technology. The effect of volume ratios of liquid to solid (6:1, 10:1 and 12:1) on the interfacial microstructure and mechanical properties of bimetal was investigated. The interfacial microstructure was analyzed using scanning electron microscope (SEM) and transmission electron microscope (TEM). The shear strength and microhardness in as-cast condition were studied at room temperature. The results show that the volume ratios of liquid to solid affect significantly the interfacial microstructure. When liquid-solid volume ratio was 6:1, the unbonded region was detected in interface region because the imported heat energy cannot support effectively the diffusion of element, whereas, when liquid-solid volume ratios reach 10:1 and 12:1, a sound interfacial microstructure was achieved by the diffusion of C, Cr, Mo, Cu and Mn, and metallurgical bonding without unbonded region, void and hole, etc. was detected. With the increase of liquid-solid volume ratio, the elemental diffusion activity improves, resulting in the increase of width of interface transition region. At the same distance from interface, with the increase of liquid-solid volume ratio, the microhardness is degraded in HCCI, but increased in MCS. The shear strength is also improved with the increase of liquid-solid volume ratio.

  1. Evaluation of bimetal doped TiO2 in dye fragmentation and its comparison to mono-metal doped and bare catalysts

    Science.gov (United States)

    Malika, Manjakuppam; Rao, Ch. Venkatanarasimha; Das, Raj Kumar; Giri, Ardhendu Sekhar; Golder, Animes Kumar

    2016-04-01

    There are instances that bimetal doped semiconductor materials impart superior photocatalytic activity than bare and mono-metal doping. In this study, visible light responsive mono- (Cu/TiO2 and Ni/TiO2) and bi-metal doped (Cu-Ni/TiO2) TiO2 photocatalysts with wide band gap energy were synthesized via co-precipitation method with an equal mass ratio of Cu and Ni. The catalyst characterization was performed using Diffuse Reflectance UV-visible (DR-UV-vis) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), zeta-potential and Transmission Electron Microscopy (TEM) analyzes. The charge balancing effect of Cu and Ni caused a notable reduction in the optical band gap of TiO2 to 2.91 eV with Cu-Ni/TiO2. The synthesis method increased the anatase phase significantly along with the crystallite size. Cu-Ni/TiO2 displayed a lesser destabilization tendency, and the absolute value of zeta-potentials increased much at pH > pHzpc resulted from the higher oxygen vacancies. The activity of Ni/TiO2, Cu/TiO2, and Cu-Ni/TiO2 was tested for the degradation dynamics and kinetics of Eriochrome Cyanine Red (ECR), an anionic dye. Cu doping exhibited a better dye decomposition because of the low recombination rate of electron/hole pair as a full 3d sub-level of Cu is energetically more favorable than a full 4s sub-level of Ni. The mechanism of dye decomposition releasing inorganic ions is also proposed and validated from the mass spectra.

  2. Development of bimetal-grown multi-scale carbon micro-nanofibers as an immobilizing matrix for enzymes in biosensor applications

    International Nuclear Information System (INIS)

    This study describes the development of a novel bimetal (Fe and Cu)-grown hierarchical web of carbon micro-nanofiber-based electrode for biosensor applications, in particular to detect glucose in liquids. Carbon nanofibers (CNFs) are grown on activated carbon microfibers (ACFs) by chemical vapor deposition (CVD) using Cu and Fe as the metal catalysts. The transition metal-fiber composite is used as the working electrode of a biosensor applied to detect glucose in liquids. In such a bi-nanometal-grown multi-scale web of ACF/CNF, Cu nanoparticles adhere to the ACF-surface, whereas Fe nanoparticles used to catalyze the growth of nanofibers attach to the CNF tips. By ultrasonication, Fe nanoparticles are dislodged from the tips of the CNFs. Glucose oxidase (GOx) is subsequently immobilized on the tips by adsorption. The dispersion of Cu nanoparticles at the substrate surface results in increased conductivity, facilitating electron transfer from the glucose solution to the ACF surface during the enzymatic reaction with glucose. The prepared Cu-ACF/CNF/GOx electrode is characterized for various surface and physicochemical properties by different analytical techniques, including scanning electron microscopy (SEM), electron dispersive X-ray analysis (EDX), Fourier-transform infrared spectroscopy (FTIR), BET surface area analysis, and transmission electron microscopy (TEM). The electrochemical tests show that the prepared electrode has fast response current, electrochemical stability, and high electron transfer rate, corroborated by CV and calibration curves. The prepared transition metal-based carbon electrode in this study is cost-effective, simple to develop, and has a stable immobilization matrix for enzymes. - Graphical abstract: A novel bimetal (Fe and Cu)-grown hierarchical web of carbon micro-nanofiber-based electrode is synthesized for biosensor applications, in particular to detect glucose in liquids. Carbon nanofibers are grown on activated carbon microfibers by

  3. Development of bimetal-grown multi-scale carbon micro-nanofibers as an immobilizing matrix for enzymes in biosensor applications

    Energy Technology Data Exchange (ETDEWEB)

    Hood, Amit R. [Department of Chemical Engineering, Indian Institute of Technology, Kanpur (India); Saurakhiya, Neelam; Deva, Dinesh [DST Unit on Nanosciences, Kanpur, 208016 (India); Sharma, Ashutosh [Department of Chemical Engineering, Indian Institute of Technology, Kanpur (India); DST Unit on Nanosciences, Kanpur, 208016 (India); Verma, Nishith, E-mail: nishith@iitk.ac.in [Department of Chemical Engineering, Indian Institute of Technology, Kanpur (India); Center for Environmental Science and Engineering, Kanpur 208016 (India)

    2013-10-15

    This study describes the development of a novel bimetal (Fe and Cu)-grown hierarchical web of carbon micro-nanofiber-based electrode for biosensor applications, in particular to detect glucose in liquids. Carbon nanofibers (CNFs) are grown on activated carbon microfibers (ACFs) by chemical vapor deposition (CVD) using Cu and Fe as the metal catalysts. The transition metal-fiber composite is used as the working electrode of a biosensor applied to detect glucose in liquids. In such a bi-nanometal-grown multi-scale web of ACF/CNF, Cu nanoparticles adhere to the ACF-surface, whereas Fe nanoparticles used to catalyze the growth of nanofibers attach to the CNF tips. By ultrasonication, Fe nanoparticles are dislodged from the tips of the CNFs. Glucose oxidase (GOx) is subsequently immobilized on the tips by adsorption. The dispersion of Cu nanoparticles at the substrate surface results in increased conductivity, facilitating electron transfer from the glucose solution to the ACF surface during the enzymatic reaction with glucose. The prepared Cu-ACF/CNF/GOx electrode is characterized for various surface and physicochemical properties by different analytical techniques, including scanning electron microscopy (SEM), electron dispersive X-ray analysis (EDX), Fourier-transform infrared spectroscopy (FTIR), BET surface area analysis, and transmission electron microscopy (TEM). The electrochemical tests show that the prepared electrode has fast response current, electrochemical stability, and high electron transfer rate, corroborated by CV and calibration curves. The prepared transition metal-based carbon electrode in this study is cost-effective, simple to develop, and has a stable immobilization matrix for enzymes. - Graphical abstract: A novel bimetal (Fe and Cu)-grown hierarchical web of carbon micro-nanofiber-based electrode is synthesized for biosensor applications, in particular to detect glucose in liquids. Carbon nanofibers are grown on activated carbon microfibers by

  4. The TP0796 Lipoprotein of Treponema pallidum Is a Bimetal-dependent FAD Pyrophosphatase with a Potential Role in Flavin Homeostasis*

    Science.gov (United States)

    Deka, Ranjit K.; Brautigam, Chad A.; Liu, Wei Z.; Tomchick, Diana R.; Norgard, Michael V.

    2013-01-01

    Treponema pallidum, an obligate parasite of humans and the causative agent of syphilis, has evolved the capacity to exploit host-derived metabolites for its survival. Flavin-containing compounds are essential cofactors that are required for metabolic processes in all living organisms, and riboflavin is a direct precursor of the cofactors FMN and FAD. Unlike many pathogenic bacteria, Treponema pallidum cannot synthesize riboflavin; we recently described a flavin-uptake mechanism composed of an ABC-type transporter. However, there is a paucity of information about flavin utilization in bacterial periplasms. Using a discovery-driven approach, we have identified the TP0796 lipoprotein as a previously uncharacterized Mg2+-dependent FAD pyrophosphatase within the ApbE superfamily. TP0796 probably plays a central role in flavin turnover by hydrolyzing exogenously acquired FAD, yielding AMP and FMN. Biochemical and structural investigations revealed that the enzyme has a unique bimetal Mg2+ catalytic center. Furthermore, the pyrophosphatase activity is product-inhibited by AMP, indicating a possible role for this molecule in modulating FMN and FAD levels in the treponemal periplasm. The ApbE superfamily was previously thought to be involved in thiamine biosynthesis, but our characterization of TP0796 prompts a renaming of this superfamily as a periplasmic flavin-trafficking protein (Ftp). TP0796 is the first structurally and biochemically characterized FAD pyrophosphate enzyme in bacteria. This new paradigm for a bacterial flavin utilization pathway may prove to be useful for future inhibitor design. PMID:23447540

  5. Effect of bimetal Hg2+ and Cu2+on activity and conformation of papain%双金属Hg2+和Cu2+对木瓜蛋白酶活性与构象的影响

    Institute of Scientific and Technical Information of China (English)

    张存滢; 曾虹燕; 熊龙斌; 刘学英; Gohi A; 蔡西玲; 陈泽新

    2013-01-01

    The effect of the bimetal Hg2+ and Cu2+ on activity and conformation of papain was studied.The secondary structures of the papain treated by the bimetal ions were investigated by characterization using FT-IR,fluorescence emitting and ultraviolet-absorption spectra.The results show that there exists the dosage-response relationship between the metals and papain activity,which indicates that the bimetal ions have Hormesis effect on the activity known as “a low dose stimulation,high dose inhibition”.Under low concentration,the bimetal ions exhibit synergistic activation effect on papain activity,and Cu2+ shields Hg2+ inhibition on the activity at high concentration.On the one hand,when the concentrations of Hg2+ and Cu2+ are 10-6 and 10-8 mol/L respectively,the strongest activity effect of the bimetal ions on papain is obtained.The content of the nonrandom secondary structures (α-helix and β-sheet) of the treated papain is the highest with the secondary structures of papain being most stable,and enzymatic affinity strongest and papain activity being best.When the concentrations of Hg2+ and Cu2+ are 10-4mol/L,the ordered structure content and papain activity are the lowest.The bimetal ions unfold the enzymic protein and cause the destruction of the secondary structures.The order degree ofpapain conformation is correlated positively with the activity.%研究双金属Hg2+和Cu2+对木瓜蛋白酶活性与构象的影响.利用FT-IR、荧光发射以及紫外吸收光谱探讨Hg2+和Cu2+处理与木瓜蛋白酶二级结构变化的关系.研究结果表明:金属离子与木瓜蛋白酶活性之间存在剂量-效应关系,表现出低剂量促进,高剂量抑制的Hormesis现象.低浓度下,双金属Hg2+和Cu2+表现出协同激活效应;高浓度下,Cu2+的添加屏蔽了Hg2+的抑制作用.双金属离子浓度为10-6 mol/L Hg2+和10-8 mol/L Cu2+时,对酶的激活效应最大,其处理的木瓜蛋白酶的有序结构(α-螺旋和β-折叠)含量最高,二

  6. Nanocasted synthesis of magnetic mesoporous iron cerium bimetal oxides (MMIC) as an efficient heterogeneous Fenton-like catalyst for oxidation of arsenite

    International Nuclear Information System (INIS)

    Highlights: • MMIC with large surface area and pore volume was synthesized via the hard template. • MMIC could be easily separated from aqueous solution with an external magnetic field. • MMIC presented excellent catalytic activity for the oxidation of As(III). • As(III) was mainly oxidized by surface-bound ·OHads and free ·OHfree radicals. • MMIC played a dual function role for the arsenic removal in aqueous solution. - Abstract: Magnetic mesoporous iron cerium bimetal oxides (MMIC) with large surface area and pore volume was synthesized via the hard template approach. This obtained MMIC was easily separated from aqueous solution with an external magnetic field and was proposed as a heterogeneous Fenton-like catalyst for oxidation of As(III). The MMIC presented excellent catalytic activity for the oxidation of As(III), achieving almost complete oxidation of 1000 ppb As(III) after 60 min and complete removal of arsenic species after 180 min with reaction conditions of 0.4 g/L catalyst, pH of 3.0 and 0.4 mM H2O2. Kinetics analysis showed that arsenic removal followed the pseudo-first order, and the pseudo-first-order rate constants increased from 0.0014 min−1 to 0.0548 min−1 as the H2O2 concentration increased from 0.04 mM to 0.4 mM. On the basis of the effects of XPS analysis and reactive oxidizing species, As(III) in aqueous solution was mainly oxidized by ·OH radicals, including the surface-bound ·OHads generated on the MMIC surface which were involved in ≡Fe2+ and ≡Ce3+, and free ·OHfree generation by soluble iron ions which were released from the MMIC into the bulk solution, and the generated As(V) was finally removed by MMIC through adsorption

  7. Nanocasted synthesis of magnetic mesoporous iron cerium bimetal oxides (MMIC) as an efficient heterogeneous Fenton-like catalyst for oxidation of arsenite

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Zhipan [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Zhang, Yalei, E-mail: zhangyalei@tongji.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Dai, Chaomeng [College of Civil Engineering, Tongji University, Shanghai 200092 (China); Sun, Zhen [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

    2015-04-28

    Highlights: • MMIC with large surface area and pore volume was synthesized via the hard template. • MMIC could be easily separated from aqueous solution with an external magnetic field. • MMIC presented excellent catalytic activity for the oxidation of As(III). • As(III) was mainly oxidized by surface-bound ·OH{sub ads} and free ·OH{sub free} radicals. • MMIC played a dual function role for the arsenic removal in aqueous solution. - Abstract: Magnetic mesoporous iron cerium bimetal oxides (MMIC) with large surface area and pore volume was synthesized via the hard template approach. This obtained MMIC was easily separated from aqueous solution with an external magnetic field and was proposed as a heterogeneous Fenton-like catalyst for oxidation of As(III). The MMIC presented excellent catalytic activity for the oxidation of As(III), achieving almost complete oxidation of 1000 ppb As(III) after 60 min and complete removal of arsenic species after 180 min with reaction conditions of 0.4 g/L catalyst, pH of 3.0 and 0.4 mM H{sub 2}O{sub 2}. Kinetics analysis showed that arsenic removal followed the pseudo-first order, and the pseudo-first-order rate constants increased from 0.0014 min{sup −1} to 0.0548 min{sup −1} as the H{sub 2}O{sub 2} concentration increased from 0.04 mM to 0.4 mM. On the basis of the effects of XPS analysis and reactive oxidizing species, As(III) in aqueous solution was mainly oxidized by ·OH radicals, including the surface-bound ·OH{sub ads} generated on the MMIC surface which were involved in ≡Fe{sup 2+} and ≡Ce{sup 3+}, and free ·OH{sub free} generation by soluble iron ions which were released from the MMIC into the bulk solution, and the generated As(V) was finally removed by MMIC through adsorption.

  8. Analysis of fracture modes during extrusion and drawing of bimetal rods or wire. Analytical study of drawing and extrusion of superconducting filamentary wires: fracture problems and evaluation of temperature rise. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Avitzur, B.; Wu, R.; Chou, Y.T.; Talbert, S.

    1984-01-09

    Based on the upper-bound theorem in limit analysis, a theoretical model describing sound flow, core fracture, and sleeve fracture in bimetal rods and wire during extrusion and drawing was developed. The variables affecting core and sleeve fracture are: reduction in area, die geometry, friction, relative size and strength of the core, and applied surface tractions. Within the wide range of combinations of these process variables, only a small range permits co-extrusion and codrawing without fracture. Criteria for the prevention of core and sleeve fracture during co-extrusion and core fracture during co-drawing were developed and presented graphically in this study. The results were applied to the central burst problem during extrusion and drawing of homogeneous materials.

  9. Intermetallic Phase Formation in Explosively Welded Al/Cu Bimetals

    Science.gov (United States)

    Amani, H.; Soltanieh, M.

    2016-05-01

    Diffusion couples of aluminum and copper were fabricated by explosive welding process. The interface evolution caused by annealing at different temperatures and time durations was investigated by means of optical microscopy, scanning electron microscopy equipped with energy dispersive spectroscopy, and x-ray diffraction. Annealing in the temperature range of 573 K to 773 K (300 °C to 500 °C) up to 408 hours showed that four types of intermetallic layers have been formed at the interface, namely Al2Cu, AlCu, Al3Cu4, and Al4Cu9. Moreover, it was observed that iron trace in aluminum caused the formation of Fe-bearing intermetallics in Al, which is near the interface of the Al-Cu intermetallic layers. Finally, the activation energies for the growth of Al2Cu, AlCu + Al3Cu4, Al4Cu9, and the total intermetallic layer were calculated to be about 83.3, 112.8, 121.6, and 109.4 kJ/mol, respectively. Considering common welding methods (i.e., explosive welding, cold rolling, and friction welding), although there is a great difference in welding mechanism, it is found that the total activation energy is approximately the same.

  10. Progress in the characterization of explosively joined Ti/Ni bimetals

    International Nuclear Information System (INIS)

    Highlights: • Titanium Grade 1 and pure nickel were successfully joined by explosive technique. • None of the bimetallic samples failed during the bending test. • The structure of the Ti and Ni components in the interface was refined. • The annealing resulted in the diffusion at the Ti/Ni interface. • The plastic deformation resulted in the strengthening at the Ti/Ni interface. - Abstract: This paper is concerned with the joint of pure titanium Grade 1 with pure nickel obtained by explosive joining. The structure and mechanical properties of the as-received raw materials, the Ti/Ni joints, and the joints after annealing were examined as well as the changes that occur at the interface between these two metals. Based on the results obtained, the mechanism involved in the formation of the joint and its nature were analyzed in the light of the existing theories. The microstructure and chemical composition of the joints were examined in a scanning electron microscope (SEM) equipped with energy dispersive spectroscopy system (EDS) and scanning transmission electron microscope (STEM). The thin foils for STEM observations were prepared using a focus ion beam system (FIB). The examinations revealed that, after the explosive joining, the structure of the Ti and Ni components in the vicinity of the joint was refined, which strongly affected their properties. The annealing at a temperature of 600 °C for 1 h resulted in the occurrence of diffusive layers from the Ni–Ti system at the Ti/Ni interface. The deformation-induced strengthening of the metals and the strength of the joint were estimated by microhardness measurements and three-point bending tests. In the vicinity of the joint the hardness appeared to be considerably increased. None of the samples subjected to the bending tests failed, and no cracking or delamination was observed

  11. Rapid degradation of hexachlorobenzene by micron Ag/Fe bimetal particles

    Institute of Scientific and Technical Information of China (English)

    Xiaoqin Nie; Jianguo Liu; Xianwei Zeng; Dongbei Yue

    2013-01-01

    The feasibility of the rapid degradation of hexachlorobenzene (HCB) by micron-size silver (Ag)/iron (Fe) particles was investigated.Ag/Fe particles with different ratios (0,0.05%,0.09%,0.20%,and 0.45%) were prepared by electroless silver plating on 300 mesh Fe powder,and were used to degrade HCB at different pH values and temperatures.The dechlorination ability of Fe greatly increased with small Ag addition,whereas too much added Ag would cover the Fe surface and reduce the effective reaction surface,thereby decreasing the extent of dechlorination.The optimal Ag/Fe ratio was 0.09%.Tafel polarization curves showed that HCB was rapidly degraded at neutral or acidic pH,whereas low pH levels severely intensified H2 production,which consumed the reducing electrons needed for the HCB degradation.HCB degradation was more sensitive to temperature than pH.The rate constant of HCB dechlorination was 0.452 min-1 at 85℃,50 times higher than that at 31℃.HCB was degraded in a successive dechlorination pathway,yielding the main products 1,2,4,5-tetrachlorobenzene and 1,2,4-trichlorobenzene within 2 hr.

  12. Formation of quasiperiodic bimetal thin films with controlled optical and electrical properties

    Science.gov (United States)

    Arakelian, S.; Vartanyan, T.; Istratov, A.; Kutrovskaya, S.; Kucherik, A.; Itina, T.; Osipov, A.

    2016-04-01

    Synthesis of transparent conductive coatings is a promising direction of modern nanotechnological research. Thin nanostructured noble-metallic films demonstrate nonlinear optical effects in visible spectral range because of their plasmonic properties [1]. In addition, optical characteristics of these thin films strongly depend on the period of the formed surface structures [2]. If the distance between deposited particles almost equals their sizes, the optical properties of the randomly deposited structures may considerably differ from these for periodical structures [3]. In this work, we have studied the degree of the morphology influence (particle diameter in the colloid, the distance between the deposited particles, the number of layers etc.) on the optical and electrical properties of the deposited thin film of bimetallic gold and silver clusters. In this work we used CW-laser with moderate intensity in liquid (water or ethanol) for synthesis nanoparticles of noble metals. For the formation of quasi-periodically arranged clusters, particle deposition from the colloidal systems is used. The optical properties of the deposited bimetallic films are shown to change as a function of composition and geometry in agreement with the modeling of the optical properties.

  13. Study of energy transfer between molecules placed in the vicinity of a bimetal composite nanoparticle

    Energy Technology Data Exchange (ETDEWEB)

    Daneshfar, Nader, E-mail: ndaneshfar@gmail.com, E-mail: ndaneshfar@razi.ac.ir [Department of Physics, Razi University, Kermanshah (Iran, Islamic Republic of)

    2015-10-15

    In this study, the problem of energy transfer between two molecules near a bimetallic composite nanoparticle is investigated. The influence of the interaction between metal particles on the intermolecular energy is studied, because when two metal nanoparticles are placed close to each other, their plasmons coupling giving rise to new features. On the other hand, we discuss the transfer of resonance energy between donor and acceptor molecules (a single donor and a single acceptor) in the presence of a nanocomposite containing gold and silver nanoparticles based on the Maxwell-Garnett effective medium theory and within the quasistatic limit. We show that the interaction energy strongly depends on the particle size, the filling factor of metal particles, the intermolecular distance (the distance between the donor and acceptor molecules), and the dielectric constant of host matrix.

  14. Synthesis, Characterization, and Use of Novel Bimetal Oxide Catalyst for Photoassisted Degradation of Malachite Green Dye

    Directory of Open Access Journals (Sweden)

    K. L. Ameta

    2014-01-01

    Full Text Available This work reports a simple, novel, and cost effective synthesis of nanobimetal oxide catalyst using cerium and cadmium nitrates as metal precursors. The cerium-cadmium oxide nanophotocatalyst was synthesized by coprecipitation method and characterized by X-ray powder diffraction method to analyze the particle size. XRD study reveals a high degree of crystallinity and 28.43 nm particle size. The photocatalytic efficiency of the synthesized nanobimetal catalyst was examined by using it for the photocatalytic degradation of malachite green dye. Experiments were conducted to study the effect of various parameters, such as the pH of the dye solution, concentration of dye, amount of catalyst, and light intensity on the rate of dye degradation. The progress of the dye degradation was monitored spectrophotometrically by taking the optical density of the dye solution at regular intervals. Experimental results indicate that the dye degrades best at pH 8.0 with light intensity 600 Wm−2 and catalyst loading 0.03 g/50 mL of dye solution. The rate constant for the reaction was 7.67 × 10−4 s−1.

  15. Crack growth rate under cyclic bending in the explosively welded steel/titanium bimetals

    International Nuclear Information System (INIS)

    Highlights: ► The results of the tests on fatigue crack growth in a steel/titanium composite under oscillatory bending. ► Hardness of both joined materials in all their section is higher than hardness of the materials before cladding. ► The main crack propagated in the direction parallel to the loading action and they did not include secondary cracks. ► When the crack growth was being passed along the interface line, decrease of the crack growth rate took place. -- Abstract: The paper presents the results of the tests on fatigue crack growth in a steel/titanium composite under oscillatory bending. Two kinds of specimens of rectangular cross sections were tested. In the tested specimens, the ratio of heights of basic and overlaid materials was h1:h2 = 2.5:1 and 1:1. In the specimens, the fatigue crack growth was parallel to the applied loading and its direction changed at the interface line. Next, the crack growth along the interface line or the crack growth passing through the interface line were observed. When the crack growth passed along the interface line, decrease of the crack growth rate took place. The specimens have the uniform crack growth at both sides of lateral surfaces. At the composite fractures in the steel and titanium, transcrystalline cracks are dominating.

  16. A Fiber Bragg Grating—Bimetal Temperature Sensor for Solar Panel Inverters

    OpenAIRE

    Mohd Afiq Ismail; Nizam Tamchek; Muhammad Rosdi Abu Hassan; Dambul, Katrina D.; Jeyraj Selvaraj; Nasrudin Abd Rahim; Seyed Reza Sandoghchi; Faisal Rafiq Mahamd Adikan

    2011-01-01

    This paper reports the design, characterization and implementation of a Fiber Bragg Grating (FBG)-based temperature sensor for an Insulted-Gate Bipolar Transistor (IGBT) in a solar panel inverter. The FBG is bonded to the higher Coefficient of Thermal Expansion (CTE) side of a bimetallic strip to increase its sensitivity. Characterization results show a linear relationship between increasing temperature and the wavelength shift. It is found that the sensitivity of the sensor can be categorize...

  17. Rapid degradation of hexachlorobenzene by micron Ag/Fe bimetal particles.

    Science.gov (United States)

    Nie, Xiaoqin; Liu, Jianguo; Zeng, Xianwei; Yue, Dongbei

    2013-03-01

    The feasibility of the rapid degradation of hexachlorobenzene (HCB) by micron-size silver (Ag)/iron (Fe) particles was investigated. Ag/Fe particles with different ratios (0, 0.05%, 0.09%, 0.20%, and 0.45%) were prepared by electroless silver plating on 300 mesh Fe powder, and were used to degrade HCB at different pH values and temperatures. The dechlorination ability of Fe greatly increased with small Ag addition, whereas too much added Ag would cover the Fe surface and reduce the effective reaction surface, thereby decreasing the extent of dechlorination. The optimal Ag/Fe ratio was 0.09%. Tafel polarization curves showed that HCB was rapidly degraded at neutral or acidic pH, whereas low pH levels severely intensified H2 production, which consumed the reducing electrons needed for the HCB degradation. HCB degradation was more sensitive to temperature than pH. The rate constant of HCB dechlorination was 0.452 min- at 85 degrees C, 50 times higher than that at 31 degrees C. HCB was degraded in a successive dechlorination pathway, yielding the main products 1,2,4,5-tetrachlorobenzene and 1,2,4-trichlorobenzene within 2 hr. PMID:23923419

  18. Un catalizador bimetálico para el tratamiento de aguas que contienen nitratos

    OpenAIRE

    Corma, Avelino; Palomares Gimeno, Antonio Eduardo; Prato, José Gregorio

    2008-01-01

    Traducción de Patente Europea E02740773 (fecha de solicitud, 14/06/2002).-- Prioridad: ES20010615200101471.-- Titulares: Consejo Superior de Investigaciones Científicas (CSIC), Universidad Politécnica de Valencia (UPV).

  19. Comparison of corrosion behavior between fusion cladded and explosive cladded Inconel 625/plain carbon steel bimetal plates

    International Nuclear Information System (INIS)

    Highlights: ► Both explosive and fusion cladding aggravate the corrosion resistance of Inconel 625. ► Fusion cladding is more detrimental to nonuniform corrosion resistance. ► Single-layered fusion coat does not show any repassivation ability. ► Adding more layers enhance the corrosion resistance of fusion cladding Inconel 625. ► High impact energy spoils the corrosion resistance of explosive cladding Inconel 625. -- Abstract: One of the main concerns in cladding Inconel 625 superalloy on desired substrates is deterioration of corrosion resistance due to cladding process. The present study aims to compare the effect of fusion cladding and explosive cladding procedures on corrosion behavior of Inconel 625 cladding on plain carbon steel as substrate. Also, an attempt has been made to investigate the role of load ratio and numbers of fusion layers in corrosion behavior of explosive and fusion cladding Inconel 625 respectively. In all cases, the cyclic polarization as an electrochemical method has been applied to assess the corrosion behavior. According to the obtained results, both cladding methods aggravate the corrosion resistance of Inconel 625. However, the fusion cladding process is more detrimental to nonuniform corrosion resistance, where the chemical nonuniformity of fusion cladding superalloy issuing from microsegregation, development of secondary phases and contamination of clad through dilution hinders formation of a stable passive layer. Moreover, it is observed that adding more fusion layers can enhance the nonuniform corrosion resistance of fusion cladding Inconel 625, though this resistance still remains weaker than explosive cladding superalloy. Also, the results indicate that raising the impact energy in explosive cladding procedure drops the corrosion resistance of Inconel 625.

  20. Gold@silver bimetal nanoparticles/pyramidal silicon 3D substrate with high reproducibility for high-performance SERS

    Science.gov (United States)

    Zhang, Chao; Jiang, Shou Zhen; Yang, Cheng; Li, Chong Hui; Huo, Yan Yan; Liu, Xiao Yun; Liu, Ai Hua; Wei, Qin; Gao, Sai Sai; Gao, Xing Guo; Man, Bao Yuan

    2016-01-01

    A novel and efficient surface enhanced Raman scattering (SERS) substrate has been presented based on Gold@silver/pyramidal silicon 3D substrate (Au@Ag/3D-Si). By combining the SERS activity of Ag, the chemical stability of Au and the large field enhancement of 3D-Si, the Au@Ag/3D-Si substrate possesses perfect sensitivity, homogeneity, reproducibility and chemical stability. Using R6G as probe molecule, the SERS results imply that the Au@Ag/3D-Si substrate is superior to the 3D-Si, Ag/3D-Si and Au/3D-Si substrate. We also confirmed these excellent behaviors in theory via a commercial COMSOL software. The corresponding experimental and theoretical results indicate that our proposed Au@Ag/3D-Si substrate is expected to develop new opportunities for label-free SERS detections in biological sensors, biomedical diagnostics and food safety. PMID:27143507

  1. 热双金属盘螺旋光指针温度计设计%Design of spiral laser pointer thermometer of thermal bimetal plate

    Institute of Scientific and Technical Information of China (English)

    张常龙; 彭元虎; 郇维亮; 李志; 徐崇

    2015-01-01

    利用双金属在不同温度下转过的角度不同,进而引起其端口反射的激光束偏转,设计了光指针温度计,并经标准温度计对其进行校准和标定.该温度计量程为5~90℃,精确度为0.5℃,可拓展常用水银温度计的测量范围.%Because the different metal materials have different thermal expansion coefficients,this study uses double metal turning to different angles at different temperatures,which causes the laser beam deflection reflection,then the light pointer thermometer is designed.The standard of the thermometer calibration and calibration,the measuring range can be expanded for the mercury thermometer.

  2. Síntesis por molienda reactiva del nitruro bimetálico Mo-Fe: Mo3Fe3N

    Directory of Open Access Journals (Sweden)

    Roldán, M. A.

    2008-02-01

    Full Text Available The transition metal nitride ternary show similar properties to the binary nitride and some times this behaviour are improved. In the present work, the molybdenum-iron nitride has been prepared by reactive grinding from the two metals under nitrogen atmosphere at a pressure of 11bar. The characterization of the compound is presented and it is also shown a study of the stability of the nitride under several atmospheres.

    Los nitruros ternarios de los metales de transición poseen propiedades comparables e incluso superiores a las de los nitruros binarios. En el presente trabajo, se preparó un nitruro ternario (Fe3Mo3N por molienda reactiva a partir de la mezcla de los dos metales en atmósfera de nitrógeno a una presión de 11 bar. Se presenta la caracterización del compuesto así como un estudio de la estabilidad del mismo en diferentes atmósferas.

  3. Porous Fe-Nx/C hybrid derived from bi-metal organic frameworks as high efficient electrocatalyst for oxygen reduction reaction

    Science.gov (United States)

    Wu, Yijin; Zhao, Shenlong; Zhao, Kun; Tu, Tengxiu; Zheng, Jianzhong; Chen, Jie; Zhou, Haifeng; Chen, Dejian; Li, Shunxing

    2016-04-01

    A simple, low-cost and large-scale synthesis method for the carbonized porous cubes (CPCs) containing Fe and N co-doped porous carbon hybrid (Fe-Nx/C) with controlled-morphology, uniform elemental distribution and well-defined pore size is developed by pyrolyzing bimetallic FeIII-modified IRMOF-3 cubes in Argon atmosphere at 800 °C. Furtherly, the CPCs are used as the electrocatalyst for oxygen reduction reaction in alkaline solution. Impressively, the CPCs hybrid exhibits a superior electrocatalytic activity with high onset potential (0.93 V) and half-wave potential (0.78 V), and excellent stability, which is attributed to the synergistic effect of its high the surface to volume ratio, well-defined pore size, multi-active composition and high exposed catalytic active sites. We believe the materials based on earth-abundant elements have a huge potential to apply in catalysis, energy, and environment.

  4. CCD双金属标仪的研制及应用%DEVELOPMENT AND APPLICATION OF CCD TYPE BI-METAL TUBE INSTRUMENT

    Institute of Scientific and Technical Information of China (English)

    赵义飞; 李农发; 欧同庚; 史雨辉

    2013-01-01

    基于双金属标的基本原理,设计了一种光电式双金属标仪,并将其成功应用于亭子口水电站大坝垂直位移安全监测系统中.运行结果表明,仪器运行状态稳定可靠,监测效果良好.

  5. Investigating the performance of TiN and TiAIN coatings on milling cutter used for machining bimetal steel strip

    OpenAIRE

    Sarwar, Mohammed; Haider, Julfikar

    2009-01-01

    Surface engineering of cutting tools (single point or multipoint) through advanced coatings (e.g., TiN) has contributed towards considerable improvement of tool life, productivity and machining quality [1] by modifying the tool substrate. New coating species (e.g., TiAlN) are also being developed to further improve the performance of cutting tools. In this study, milling tests were carried out with a TiN and TiAlN coated milling cutter to compare their performance. Physical Vapour Deposition ...

  6. A Phenomenological Study on the Synergistic Role of Precious Metals in the Steam Reforming of Logistic Fuels on Bimetal-Supported Catalysts

    Directory of Open Access Journals (Sweden)

    Abdul-Majeed Azad

    2011-01-01

    Full Text Available Fuel processors are required to convert sulfur-laden logistic fuels into hydrogen-rich reformate and deliver to the fuel cell stack with little or no sulfur. Since sulfur poisons and deactivates the reforming catalyst, robust sulfur-tolerant catalysts ought to be developed. In this paper, the development, characterization and evaluation of a series of reforming catalysts containing two noble metals (with total metal loading not exceeding 1 weight percent supported on nanoscale ceria for the steam-reforming of kerosene is reported. Due to inherent synergy, a bimetallic catalyst is superior to its monometallic analog, for the same level of loading. The choice of noble metal combination in the bimetallic formulations plays a vital and meaningful role in their performance. Presence of ruthenium and/or rhodium in formulations containing palladium showed improved sulfur tolerance and significant enhancement in their catalytic activity and stability. Rhodium was responsible for higher hydrogen yields in the logistic fuel reformate. Duration of steady hydrogen production was higher in the case of RhPd (75 h than for RuPd (68 h; hydrogen generation was stable over the longest period (88 h with RuRh containing no Pd. A mechanistic correlation between the characteristic role of precious metals in the presence of each other is discussed.

  7. Degradation of trichloroethylene (TCE) and polychlorinated biphenyls (PCBs) by Fe and Fe-Pd bimetals in the presence of surfactants and cosolvents

    International Nuclear Information System (INIS)

    Surfactants and cosolvents are being used to enhance the removal of dense non-aqueous phase liquids (DNAPL) such as trichloroethylene (TCE) and polychlorinated biphenyls (PCBS) from contaminated soils. However, the waste surfactant solution containing TCE and PCBs must be treated before it can be disposed. This study evaluated the use of zero-valence iron and palladized iron fillings on the dechlorination of TCE and a PCB congener in a dihexylsulfosuccinate surfactant solution. Batch experimental results indicated that TCE can be rapidly degraded by palladized iron filings with a half-life of 27.4 min. PCB was degraded at a slower rate than TCE with a half-life ranging from 100 min to 500 min as the concentration of surfactant increased. In column flow-through experiments, both TCE and PCBs degrade at an enhanced rate with a half-life about 1.5 and 6 min because of an increased solid to solution ratio in the column than in the batch experiments. Results of this work suggest that Fe-Pd filings may be potentially applicable for ex-situ treatment of TCE and PCBs in the surfactant solutions that are generated during surfactant washing of the contaminated soils

  8. Catálise mono e bimetálica : uma via alternativa sustentável no tratamento de efluentes

    OpenAIRE

    Freitas, Cátia Manuela Antunes da Silva

    2014-01-01

    A crescente concentração de produtos químicos nas águas e os padrões cada vez mais rigorosos no controlo da qualidade para água potável gera, a necessidade urgente de desenvolver novas tecnologias e melhorar os processos de tratamento de água. Uma grande variedade de tecnologias aplicadas ao tratamento de água, tais como processos físico-químicos, métodos biológicos e catalíticos são usados na remoção de poluentes nos quais se incluem os nitratos e os bromatos. A redução cat...

  9. Schottky bariers on InP and GaN made by deposition of colloidal graphite and Pd, Pt or bimetal Pd/Pt nanoparticles for H2-gas detection

    OpenAIRE

    Žďánský, K. (Karel); Yatskiv, R. (Roman)

    2012-01-01

    Schottky barriers on III-V compound semiconductors are still not well explored up to now. There were already reported Pd and Pt Schottky diode gas sensors using InP or GaN materials. However, reported sensing performances are surprisingly different. Thus, proper understanding of sensing mechanism is indispensable. We report on InP and GaN Schottky diode hydrogen sensors with low-leakage currents and high sensitivity, made by deposition of colloidal graphite and electrophoresis of Pd, Pt nebo ...

  10. Molding process analysis of bi-metal tubes with cold-cross-rolled process%双金属复合管冷斜轧工艺的成形过程分析

    Institute of Scientific and Technical Information of China (English)

    秦建平; 於方; 周存龙

    2004-01-01

    本文在冷斜轧理论研究的基础上,探讨了冷斜轧复合工艺生产双金属管的可行性.文中首先建立了考虑应变、应变率、润滑条件和材料加工硬化等因素的钢管冷斜轧过程的数学模型,然后利用塑性成形问题的刚塑性有限元算法计算了钢管冷斜轧过程中塑性变形区的各种分布量,如速度场、应力、应变场等,其结果对选择合理的工艺参数、生产大直径双金属复合管具有重要意义.

  11. Schottky bariers on InP and GaN made by deposition of colloidal graphite and Pd, Pt or bimetal Pd/Pt nanoparticles for H2-gas detection

    Czech Academy of Sciences Publication Activity Database

    Žďánský, Karel; Yatskiv, Roman

    2012-01-01

    Roč. 165, č. 1 (2012), s. 104-109. ISSN 0925-4005 Institutional support: RVO:67985882 Keywords : semiconductor devices * nanostructures * sensors Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.535, year: 2012

  12. 双金属自密封波齿垫片结构参数及密封性能研究%Study on Structural Parameters and Sealing Performance of Bimetal Seal Corrugated Composite Gasket

    Institute of Scientific and Technical Information of China (English)

    周先军; 卫朋; 尚庆军

    2015-01-01

    The study plot was planed with four factors and three grades adopting orthogonal experimental design method.The compressibility and resilience performance of the new gaskets was investigated adop-ting finite element analysis,the sealing performance was discussed between the new gasket and flexible graphite corrugated metal gasket.The result shows that the major element that greatly affects the compres-sibility and resilience performance of the gasket are graphite and gap;the excellent scheme is A1 B1 C1 D1;compared with the flexible graphite corrugated metal gasket,the new gasket has a better sealing perform-ance.%对双金属自密封波齿垫片运用正交试验方法设计了四因素三水平的试验方案,采用有限元方法研究其压缩回弹性能,并比较相同结构参数下波齿复合垫片与双金属自密封波齿垫片的密封性能。研究结果表明:石墨覆盖层厚度是影响双金属自密封波齿垫片压缩率的显著因素,缝宽是影响其回弹率的显著因素,双金属自密封波齿垫片的优选方案为A1 B1 C1 D1;相同预紧力下双金属自密封波齿垫片可以密封较高的内压。

  13. Síntesis y caracterización de catalizadores bimetálicos nanoestructurados basados en bajo contenido de pt para aplicaciones en celdas de combustibles tipo pem /

    OpenAIRE

    Sandoval González, Antonia

    2012-01-01

     tesis que para obtener el grado de Doctorado en Ingeniería (Energía), presenta Antonia Sandoval González ; asesor Sergio Alberto Gamboa Sánchez143 páginas : ilustracionesDoctorado en Ingeniería (Energía) UNAM, Centro de Investigación en Energía, 2012

  14. Determination of minimum admissible thickness of corrosion-resistant coating of nuclear power plant vessels

    International Nuclear Information System (INIS)

    The effect of technological heatings and treatments of the 22K+08Kh18N10T bimetal on diffusion of alloying elements is investigated. The results of investigation are given. Investigations have been carried out in order to determine the minimum admissible thickness of the clad layer of the bimetal produced by explosion welding. It is established that the clad layer with thickness of 3 mm in the two-layer steel, produced by explosion welding, provides the protection of internal surface of the vessel against corrosion. During the production of steam separator for the Chernobylskaya NPS the high technological effectiveness of the bimetal has been found out. Bimetal structure investigation has shown that the thickness of non-carburized austenitic layer in the articles constitutes 1.2 mm. Investigations of Cr and Ni diffusion have shown that these elements diffuse at the depth of 15-2O μm

  15. Dynamic study for performance improvements of a thermo-mechanically bistable heat engine

    Science.gov (United States)

    Boughaleb, J.; Arnaud, A.; Monfray, S.; Cottinet, P. J.; Quenard, S.; Pitone, G.; Boeuf, F.; Guyomar, D.; Skotnicki, T.

    2015-12-01

    This paper focuses on a thermal study of a thermal energy harvester based on the coupling of a bimetallic strip heat engine with a piezoelectric membrane for wasted heat scavenging. Such a harvester is dedicated to power autonomous systems such as wireless sensor nodes. For a better understanding of the working principle of the system, it is compulsory to have a good understanding of the thermal specificities and phenomenon taking place inside the harvester. Attention is consequently focused on the thermal modeling of the harvester in static mode using the equivalence between the electrical and thermal quantities. This first modeling step allowed the improvement of the thermal properties inside the system by increasing the thermal gradient across it. However, the bimetal being the active part of the system has not been taken into account in this model and shadow zones persisted regarding the bimetal operation windows as a function of its snapping temperatures and hysteresis. To overcome this, a dynamic model is proposed in this paper taking into account the bimetal as a switched capacitance alternatively in contact with the hot source and the cold surface. This last model completed the static one by predicting the bimetal's operation windows in function of its intrinsic properties and the operation range evolution in function of the snapping temperature first and then in function of the bimetal thermal hysteresis. Moreover, experimental measurements enable to validate the proposed model and to point out the most powerful bimetals for scavenging higher amounts of power.

  16. Síntesis de Pt-SnlC y Pt-RulC y su respuesta de electro oxidación de etanol para aplicaciones en CCAD

    OpenAIRE

    Ginez C, F.; Garcia L, M.A.; Gamboa, S.A.

    2012-01-01

    Se realizó la sintesis de los cat:alizadores bimetá1icos Pt-Sn y Pt-Ru via coloidal, mediante un proceso de alcohol-reducción asistido por microondas, sin emplear un agente reductorni un agente estabilizador de las partículas bimetálicas. Se soportaron en Carbón Vulcan XC72R (CV) tratado con un agente oxidante. Se realizó la caracterización estructural mediante rayos-x, asi como, la caracterización electroquimica en la reacción de electro-oxidación de etanol (REE) mediante Voltamperometrla Cí...

  17. Fe/Al bimetallic particles for the fast and highly efficient removal of Cr(VI) over a wide pH range: Performance and mechanism.

    Science.gov (United States)

    Fu, Fenglian; Cheng, Zihang; Dionysiou, Dionysios D; Tang, Bing

    2015-11-15

    The iron/aluminum (Fe/Al) bimetallic particles with high efficiency for the removal of Cr(VI) were prepared. Fe/Al bimetallic particles were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), SEM mapping, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). SEM mapping showed that the core of bimetal was Al, and the planting Fe was deposited on the surface of Al. In acidic and neutral conditions, Fe/Al bimetal can completely remove Cr(VI) from wastewater in 20 min. Even at pH 11.0, the Cr(VI) removal efficiency achieved was 93.5%. Galvanic cell effect and high specific surface area are the main reasons for the enhanced removal of Cr(VI) by bimetallic particles. There were no iron ions released in solutions at pH values ranging from 3.0 to 11.0. The released Al(3+) ions concentrations in acidic and neutral conditions were all less than 0.2mg/L. The bimetal can be used 4 times without losing activity at initial pH 3.0. XPS indicated that the removed Cr(VI) was immobilized via the formation of Cr(III) hydroxide and Cr(III)-Fe(III) hydroxide/oxyhydroxide on the surface of Fe/Al bimetal. The Fe/Al bimetallic particles are promising for further testing for the rapid and effective removal of contaminants from water. PMID:26073381

  18. Locating Small Leaks in Large Structures

    Science.gov (United States)

    Lawler, W. F.

    1983-01-01

    Test tool for detecting minute leads in bimetal joints, welds, or other locations employs fine-control valve and hypodermic needle. Test item is connected in conventional manner to helium mass spectrometer tuned to read extremely small amounts of helium gas. Uniqueness of method is ability to detect tiny leaks, through surfaces, not discoverable by gross coverage of test structures by helium gas.

  19. 接触腐蚀

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Galvanic corrosion of dental amalgams in contact with titanium in terms of released ions; Corrosion behavior and galvanic coupling of stainless steels, titanium, and alloy 33 in lithium bromide solutions; Corrosion rates of steel, zinc and bi-metal couples in the field and in laboratory environments; Evaluation of protective coatings on magnesium fo rphosphate process compatibility and galvanic corrosion prevention

  20. MCCB warm adjustment testing concept

    Science.gov (United States)

    Erdei, Z.; Horgos, M.; Grib, A.; Preradović, D. M.; Rodic, V.

    2016-08-01

    This paper presents an experimental investigation in to operating of thermal protection device behavior from an MCCB (Molded Case Circuit Breaker). One of the main functions of the circuit breaker is to assure protection for the circuits where mounted in for possible overloads of the circuit. The tripping mechanism for the overload protection is based on a bimetal movement during a specific time frame. This movement needs to be controlled and as a solution to control this movement we choose the warm adjustment concept. This concept is meant to improve process capability control and final output. The warm adjustment device design will create a unique adjustment of the bimetal position for each individual breaker, determined when the testing current will flow thru a phase which needs to trip in a certain amount of time. This time is predetermined due to scientific calculation for all standard types of amperages and complies with the IEC 60497 standard requirements.

  1. Two approaches for enhancing the hydrogenation properties of palladium: Metal nanoparticle and thin film over layers

    Indian Academy of Sciences (India)

    Manika Khanuja; B R Mehta; S M Shivaprasad

    2008-11-01

    In the present study, two approaches have been used for enhancing the hydrogenation properties of Pd. In the first approach, metal thin film (Cu, Ag) has been deposited over Pd and hydrogenation properties of bimetal layer Cu (thin film)/Pd(thin film) and Ag(thin film)/Pd(thin film) have been studied. In the second approach, Ag metal nanoparticles have been deposited over Pd and hydrogenation properties of Ag (nanoparticle)/Pd (thin film) have been studied and compared with Ag(thin film)/Pd(thin film) bimetal layer system. The observed hydrogen sensing response is stable and reversible over a number of hydrogen loading and deloading cycles in both bimetallic systems. Alloying between Ag and Pd is suppressed in case of Ag(nanoparticle)/Pd(thin film) bimetallic layer on annealing as compared to Ag (thin film)/Pd(thin film).

  2. Quantitative Evaluation of Photoinduced Bending Speed of Diarylethene Crystals

    Directory of Open Access Journals (Sweden)

    Daichi Kitagawa

    2015-11-01

    Full Text Available We investigated photoinduced crystal bending behavior of various photochromic diarylethenes. In all the diarylethene derivatives we used in this work, the relationship between the initial photoinduced bending speed and the crystal thickness was well explained by the easy-handled Timoshenkoʼs bimetal model. Moreover, we proposed a quantitative analysis method to reveal the relationship between the bending speed and the molecular structure of diarylethenes. These results provide the quantitative evaluation method of the photoinduced crystal bending speed.

  3. A high sensitive fiber Bragg grating cryogenic temperature sensor

    Institute of Scientific and Technical Information of China (English)

    Kuo Li; Zhen'an Zhou; Aichun Liu

    2009-01-01

    At cryogenic temperature, a fiber Bragg grating (FBG) temperature sensor with controllable sensitivity and variable measurement range is demonstrated by using bimetal configuration. In experiments, sensitivities of -51.2, -86.4, and -520 pm/K are achieved by varying the lengths of the metals. Measurement ranges of 293 - 290.5, 283 - 280.5, and 259 - 256.5 K are achieved by shortening the distance of the gap among the metals.

  4. Fe/Al bimetallic particles for the fast and highly efficient removal of Cr(VI) over a wide pH range: Performance and mechanism

    International Nuclear Information System (INIS)

    Highlights: • Bimetallic particles with different Fe/Al mass ratios were prepared. • High removal rate of Cr(VI) was achieved in acidic, neutral, and alkaline pH. • No total iron ions at pH 3.0–11.0 and nearly no Al3+ at pH 3.0–7.0 were released. • Galvanic cell effect and high specific surface area contributed to Cr(VI) removal. - Abstract: The iron/aluminum (Fe/Al) bimetallic particles with high efficiency for the removal of Cr(VI) were prepared. Fe/Al bimetallic particles were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), SEM mapping, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). SEM mapping showed that the core of bimetal was Al, and the planting Fe was deposited on the surface of Al. In acidic and neutral conditions, Fe/Al bimetal can completely remove Cr(VI) from wastewater in 20 min. Even at pH 11.0, the Cr(VI) removal efficiency achieved was 93.5%. Galvanic cell effect and high specific surface area are the main reasons for the enhanced removal of Cr(VI) by bimetallic particles. There were no iron ions released in solutions at pH values ranging from 3.0 to 11.0. The released Al3+ ions concentrations in acidic and neutral conditions were all less than 0.2 mg/L. The bimetal can be used 4 times without losing activity at initial pH 3.0. XPS indicated that the removed Cr(VI) was immobilized via the formation of Cr(III) hydroxide and Cr(III)–Fe(III) hydroxide/oxyhydroxide on the surface of Fe/Al bimetal. The Fe/Al bimetallic particles are promising for further testing for the rapid and effective removal of contaminants from water

  5. Fluid circulating pump operated by same incident solar energy which heats energy collection fluid

    Science.gov (United States)

    Collins, E. R.

    1980-01-01

    The application of using a spacecraft solar powered pump terrestrially to reduce or eliminate the need for fossil fuel generated electricity for domestic solar hot water systems was investigated. A breadboard prototype model was constructed utilizing bimetals to convert thermal energy into mechanical motion by means of a toggle operated shutter mechanism. Although it did not meet expected thermal efficiency, the prototype model was sufficient to demonstrate the mechanical concept.

  6. The Synthesis and Photophysical Properties of New Polymetallic Complexes Designed for Use in Photoinitiated Electron Collection

    OpenAIRE

    Jones, Sumner Weston Jr.

    1998-01-01

    The goal of this research was to develop stereochemically defined multimetallic systems for use as light absorbers and electron donor / light absorber dyads in photoinitiated electron transfer and electron collection. The basis for the stereochemical control was provided by the symmetric bridging ligands 2,3,5,6-tetra(pyridyl)pyrazine (tpp) and 2,2'-bipyrimidine (bpm). The symmetric bidentate ligand 4N-perylene was designed and the majority of the synthesis was completed. The bimetal...

  7. Actual problems of ultrasonic control of welded anticorrosion coatings (ch. 1)

    International Nuclear Information System (INIS)

    Results of investigations into heat treatment effect on the size of discontinuities revealed under ultrasonic control (USC) of welded anticorrosion coatings are presented. Comparison of dimensions of equivalent area of allowable and non-allowable reflector-discantinuities (defectiveness standards) in the alloying zone of melted anticorrosion coatings and bimetal sheet, applied in NPP equipment, is given. It is shown that USC on the side of basic metal monifest almost by an order more defects than USC on the side of melting surface

  8. Functional properties of ‘Ti50Ni50–Ti49.3Ni50.7’ shape memory composite produced by explosion welding

    International Nuclear Information System (INIS)

    A bimetal composite, Ti50Ni50–Ti49.3Ni50.7, was produced by explosion welding, causing a Martensitic transformation. The functional properties of these objects were studied. It was found that explosion welding partially depressed the Martensitic transformation; however, a subsequent annealing resulted in the recovery of the kinetics of Martensitic transformations. Moreover, a variation in the annealing temperature allowed the control of a sequence of Martensitic transformations in the Ni-rich layer. The influence of the ratio of the equiatomic TiNi layer thickness to the total thickness of the bimetal composite on the recoverable strain was studied, and it was found that the maximum recoverable strain was observed when the thickness of the equiatomic TiNi layer was approximately equal to 55% of the total thickness of the sample. Functional properties were studied in the bimetal composite using the optimal ratio of the layer’s thickness. It was found that the value of the recoverable strain depended on the value of the residual strain as well as the sequence of the Martensitic transformations that occurred in the Ni-rich TiNi layer. (paper)

  9. A plunger for periodic operation of a well

    Energy Technology Data Exchange (ETDEWEB)

    Abdulzade, A.M.G.; Kondrat, R.M.; Volkovetskiy, S.V.; Yatskiv, M.P.

    1983-01-01

    A plunger is proposed for periodic operation of wells, which contains a body linked with a head and a tip, on which limiting and sealing elements concentrically installed on the body, and spacer bushings of a thermal bimetal which form cavities with the body. To increase the sealing capability of the plunger, the spacer bushings are made in the form of curved planks with a convexity towards the sealing elements. To reduce the time for heating of the spacer bushings to the assigned temperature, channels are made in the body and the head for the passage of the well liquid into the cavities formed by the spacer bushings and the body.

  10. Polyol mediated hexadecylamine capped silver allied nanobimetallic particles and their fluxional properties

    Science.gov (United States)

    Adekoya, J. A.; Dare, E. O.; Mesubi, M. A.; Revaprasadu, N.

    2015-11-01

    The syntheses of hexadecylamine seed mediated Ag/M (M=Co, Ni, Pd and Pt) allied nanobimetallic particles were successfully carried out by the successive reduction of ligand capped metal ions with polyols, resulting in concomitant precipitation of some high index faceted hybrid Ag/M bimetal nanoparticles. The optical measurements revealed the existence of surface plasmon band and peak broadening that causes diffusion processes of the metal sols to decrease making it possible to monitor the changes spectrophotometrically. The bimetallic nanoparticles were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and electron microscopy techniques which confirm the formation of alloyed clusters.

  11. Nuevas aplicaciones decorativas de aleaciones a base de aluminio-molibdeno

    OpenAIRE

    V. H. Mesa-Laguna; C. D. Hernández-Pérez; M. A. Alvarez-Pérez; J. Guzmán; M. García-Hipólito; J. A. Juárez-Islas; González, C.; O. Alvarez-Fregoso

    2005-01-01

    Las propiedades decorativas de aleaciones bimetálicas nanoestructuradas de aluminio molibdeno se han analizado en función de la composición química y los tratamientos térmicos aplicados. Sus aplicaciones decorativas se deben exclusivamente a que las aleaciones están nanoestructuradas. Las aleaciones se elaboraron a temperatura ambiente por la técnica de erosión catódica a magnetrón en atmósfera de argón, variando los tiempos de depósito para obtener diferentes grosores y composiciones elem...

  12. Development of uniform microstructures in immiscible alloys by processing in a low-gravity environment

    Energy Technology Data Exchange (ETDEWEB)

    Grugel, R.N. [Universities Space Research Association, Huntsville, AL (United States). Marshall Space Flight Center; Brush, L.N. [Univ. of Washington, Seattle, WA (United States). Dept. of Materials Science and Engineering

    1996-12-31

    Highly segregated macrostructures tend to develop during processing of hypermonotectic alloys because of the density difference existing between the two liquid phases. The {approximately}4.6 seconds of low-gravity provided by Marshall Space Flight Center`s 105 meter drop tube was utilized to minimize density-driven separation and promote uniform microstructures in hypermonotectic Ag-Ni and Ag-Mn alloys. For the Ag-Ni alloys a numerical model was developed to track heat flow and solidification of the bi-metal drop configuration. Results, potential applications, and future work are presented.

  13. Development of uniform microstructures in immiscible alloys by processing in a low-gravity environment

    Science.gov (United States)

    Grugel, Richard N.; Brush, Lucien N.

    1996-07-01

    Highly segregated macrostructures tend to develop during processing hypermonotectic alloys because of the density difference existing between the two liquid phases. The approximate 4-6 seconds of low-gravity provided by Marshall Space FLight Center's 105 meter drop tube was utilized to minimize density-driven separation and promote uniform microstructures in hypermonotectic Ag-Ni and Ag-Mn alloys. For the Ag-Ni alloys a numerical model was developed to track heat flow and solidification of the bi-metal drop configuration. Results, potential applications, and future work are presented.

  14. Fe/Al bimetallic particles for the fast and highly efficient removal of Cr(VI) over a wide pH range: Performance and mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Fenglian, E-mail: fufenglian2006@163.com [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Environmental Engineering and Science Program, Department of Biomedical, Chemical and Environmental Engineering (DBCEE), University of Cincinnati, OH 45221-0012 (United States); Cheng, Zihang [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Dionysiou, Dionysios D., E-mail: dionysios.d.dionysiou@uc.edu [Environmental Engineering and Science Program, Department of Biomedical, Chemical and Environmental Engineering (DBCEE), University of Cincinnati, OH 45221-0012 (United States); Tang, Bing [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China)

    2015-11-15

    Highlights: • Bimetallic particles with different Fe/Al mass ratios were prepared. • High removal rate of Cr(VI) was achieved in acidic, neutral, and alkaline pH. • No total iron ions at pH 3.0–11.0 and nearly no Al{sup 3+} at pH 3.0–7.0 were released. • Galvanic cell effect and high specific surface area contributed to Cr(VI) removal. - Abstract: The iron/aluminum (Fe/Al) bimetallic particles with high efficiency for the removal of Cr(VI) were prepared. Fe/Al bimetallic particles were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), SEM mapping, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). SEM mapping showed that the core of bimetal was Al, and the planting Fe was deposited on the surface of Al. In acidic and neutral conditions, Fe/Al bimetal can completely remove Cr(VI) from wastewater in 20 min. Even at pH 11.0, the Cr(VI) removal efficiency achieved was 93.5%. Galvanic cell effect and high specific surface area are the main reasons for the enhanced removal of Cr(VI) by bimetallic particles. There were no iron ions released in solutions at pH values ranging from 3.0 to 11.0. The released Al{sup 3+} ions concentrations in acidic and neutral conditions were all less than 0.2 mg/L. The bimetal can be used 4 times without losing activity at initial pH 3.0. XPS indicated that the removed Cr(VI) was immobilized via the formation of Cr(III) hydroxide and Cr(III)–Fe(III) hydroxide/oxyhydroxide on the surface of Fe/Al bimetal. The Fe/Al bimetallic particles are promising for further testing for the rapid and effective removal of contaminants from water.

  15. Diagrams of phase stability for two-dimensional Ni-Al with taking into account of vacancies presence for concentrations 0.2 %, 0.5 %, 1 %, 2 %

    International Nuclear Information System (INIS)

    Within frameworks of model in which interatomic forces have been described with help of pair Morse potentials diagrams of phase stability for two-dimensional system Ni-Al at temperatures close to absolute zero were obtained. Additionally to different options of superstructures disordered states and bimetals containing both phases of pure components at vacancies presence 0.2%, 0.5%, 1%, 2% are considered as well. Diagrams are including of charts of dependence of specific configuration energy from component concentrations with taking into account of vacancies for all possible phases of binary systems

  16. Nuevas aplicaciones decorativas de aleaciones a base de aluminio-molibdeno

    OpenAIRE

    V. H. Mesa-Laguna; C. D. Hernández-Pérez; M. A. Alvarez-Pérez; Guzmán, J; M. García-Hipólito; J. A. Juárez-Islas; González, C; O. Alvarez-Fregoso

    2005-01-01

    Las propiedades decorativas de aleaciones bimetálicas nanoestructuradas de aluminio molibdeno se han analizado en función de la composición química y los tratamientos térmicos aplicados. Sus aplicaciones decorativas se deben exclusivamente a que las aleaciones están nanoestructuradas. Las aleaciones se elaboraron a temperatura ambiente por la técnica de erosión catódica a magnetrón en atmósfera de argón, variando los tiempos de depósito para obtener diferentes grosores y composiciones element...

  17. Stress Concentration Resulting from Irregular Shape of Explosively Cladded Materials Connections - Fem Simulation

    Directory of Open Access Journals (Sweden)

    Kurek Andrzej

    2014-08-01

    Full Text Available The paper contains a numerical analysis of interface zone steel-titanium bimetal obtained by explosive cladding method. Due to the waviness of the zone, and various properties of the constituent material of the materials type contain structural notch. Therefore it is important inter alia in terms of presentation of the results of fatigue are the maximum stresses that occur just in the area of the zone. In the paper the stress concentration factor and the proposed method of modelling the joint zone of a sinusoidal profile, characterized by the same coefficient of stress concentration at the actual profile.

  18. Environmental application of millimetre-scale sponge iron (s-Fe(0)) particles (III): The effect of surface silver.

    Science.gov (United States)

    Ju, Yongming; Yu, Yunjiang; Wang, Xiaoyan; Zhang, Sukun; Liu, Runlong; Fu, Jianping; Han, Jinglei; Fang, Jiande; Dionysiou, Dionysios D

    2015-12-15

    To enhance the dechlorination reactivity of millimetric sponge iron (s-Fe(0)), a facile one-pot method was used to decorate s-Fe(0) with Ag(+) ions under ambient conditions. The results recorded by X-ray diffraction patterns, X-ray photoelectron spectra and high-resolution transmission electron microscopy demonstrated that the growth of Ag(0) was dominated primarily by (111) plane with a mean length of ∼20 nm. The roles of Ag(0) loading, catalyst dosage, particle size, initial pH and contaminant concentration were assessed during the removal of pentachlorophenol (PCP). Catalyst recyclability was also studied. The results revealed that 3-5mm s-Fe(0) particles with 5 wt% Ag(0) loading exhibited the best performance with a dose of 3.0 g per 60 mL PCP solution. In addition, the dechlorination of PCP followed two-step, pseudo-first-order reaction kinetics, and Ag(0)-s-Fe(0) was advantageous compared with bimetals of nanoscale zero-valent iron, iron power and iron flakes. The dechlorination mechanism of PCP over Ag(0)-s-Fe(0) was attributed to the surface Ag(0) decoration, which catalyzed the formation of reactive hydrogen atoms for indirect reaction, and the direct electron transfer via Fe-Ag(0) galvanic cells for direct reaction. This suggests that Ag-based bimetals of s-Fe(0) have great potential in the pretreatment of organic halogen compounds in aqueous solution. PMID:26276702

  19. Metal forming processes to produce ECN superconducting wire

    Energy Technology Data Exchange (ETDEWEB)

    Schaap, E.C.M.E.

    1991-01-01

    The main subject is modelling techniques for metal forming processes. Attention is paid to wire drawing and tube sinking. Part 1 presents the necessary mechanical background. Chapter 2 concerns the issues of the wire drawing of homogeneous isotropic material. Analytic as well as numerical approaches for modelling metal forming processes are discussed in chapter 3, each with their advantages and deficiencies. In Part 2 the applications of the simple upper-bound methods are discussed thoroughly, not because they are expected to bring the ultimate answer in solving deformation problems, but because they can bring some clarity quickly, since they are easy to apply. The upper-bound method applied on wire drawing is discussed in chapter 4; the significance of tube sinking theories is demonstrated in chapter 5 and bi-metal wire drawing in chapter 6. With the aid of the formulas based on these theories, FORTRAN programs for tube sinking and the criterion of core fraction in drawing bi-metal wire have been developed. Their purpose is explained. The finite element method will be discussed in a future report more extensively. In the last chapters some concluding remarks are made on the selection of appropriate values for process and material parameters as to produce sound wire. Recommendations are given for further research. 58 figs., 16 refs., 2 tabs.

  20. Purity-enhanced bulk synthesis of thin single-wall carbon nanotubes using iron-copper catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Lim, H E; Miyata, Y; Nakayama, T; Chen, S; Kitaura, R; Shinohara, H, E-mail: noris@nagoya-u.jp [Department of Chemistry and Institute for Advanced Research, Nagoya University, Nagoya 464-8602 (Japan)

    2011-09-30

    We report high purity and high yield synthesis of single-wall carbon nanotubes (SWCNTs) of narrow diameter from iron-copper bimetal catalysts. The SWCNTs with diameter of 0.8-1.2 nm are synthesized using the zeolite-supported alcohol chemical vapour deposition method. Single metal and bimetal catalysts are systematically investigated to achieve both the enhancement of SWCNT yield and the suppression of the undesired formation of graphitic impurities. The relative yield and purity of SWCNTs are quantified using optical absorption spectroscopy with an ultracentrifuge-based purification technique. For the single metal catalyst, iron shows the highest catalytic activity compared with the other metals such as cobalt, nickel, molybdenum, copper, and platinum. It has been found that the addition of copper to iron results in the suppression of carbonaceous impurity formation without decreasing the SWCNT yield. The purity-enhanced SWCNT shows fairly low sheet resistance due to the improvement of inter-nanotube contacts. This scalable design of SWCNT synthesis with enhanced purity is therefore a promising tool for shaping future high performance devices.

  1. ISOMERIZACION DE N-PENTANO SOBRE Pt/H-MORDENITA Y Pt-Re/H- MORDENITA-Al2O3

    OpenAIRE

    R. García-Alamilla; C. E. Ramos-Galván; G. Sandoval-Robles; J. A. Melo-Banda; L. A. García-Serrano

    2005-01-01

    Mordenita sódica se modificó con HNO3 6M para remover sodio y aluminio de la estructura de la zeolita. La mordenita se usó como soporte de catalizadores: Pt-H/mordenita y Pt-Re/H-mordenita. También se mezcló con alúmina para preparar catalizadores bimetálicos: Pt-H/mordenita-alúmina y Pt-Re/H-mordenita-alúmina. Los cuatro catalizadores se evaluaron en la isomerización de n-pentano a 250 ºC, 60 horas de reacción y presión atmosférica con el propósito de analizar el efecto de la des...

  2. MEMS based pyroelectric thermal energy harvester

    Science.gov (United States)

    Hunter, Scott R; Datskos, Panagiotis G

    2013-08-27

    A pyroelectric thermal energy harvesting apparatus for generating an electric current includes a cantilevered layered pyroelectric capacitor extending between a first surface and a second surface, where the first surface includes a temperature difference from the second surface. The layered pyroelectric capacitor includes a conductive, bimetal top electrode layer, an intermediate pyroelectric dielectric layer and a conductive bottom electrode layer. In addition, a pair of proof masses is affixed at a distal end of the layered pyroelectric capacitor to face the first surface and the second surface, wherein the proof masses oscillate between the first surface and the second surface such that a pyroelectric current is generated in the pyroelectric capacitor due to temperature cycling when the proof masses alternately contact the first surface and the second surface.

  3. Catalytic dechlorination of o-cllorophenol by nanoscale Pd/Fe

    Institute of Scientific and Technical Information of China (English)

    WEI Jian-jun; XU Xin-hua; WANG Da-hui

    2004-01-01

    Transformation of chlorophenols by nanoscale bimetallic particles represents one of the latest innovative technologies for environmental remediation. Nanoscale Pd/Fe bimetallic particles were synthesized in the laboratory for treatment of o-chlorophenol. Most of the nanoscale particles are in the size range of 20-100 nm. BET specific surface area of the nanoscale Pd/Fe particles is 12.4 m2/g. In comparison, a commercially available Fe powder( <100 mesh) has a specific surface area of just 0.49 m2/g. Batch experiments demonstrated that the nanoscale Pd/Fe bimetallic particles can effectively dechlorinate o-chlorophenol. Dechlorination efficiency is affected by the mass fraction of Pd in the bimetal, nanoscale Pd/Fe mass concentration and mixing intensity.

  4. Application of Gold Nanoparticles to Paint Colorants

    Science.gov (United States)

    Ishibashi, Hideo

    Metal nanoparticles possess unique properties that they do not exhibit in their bulk states. One of these properties is the color due to surface plasmon resonance. Gold nanoparticles appear red. This color has been utilized in glass for a long long time. In recent years, highly concentrated pastes of gold and silver nanoparticles have been successfully produced by using a special type of protective polymer and a mild reductant. The paste of gold nanoparticles can be used for paint and other materials as red colorants. In this article,application examples of gold nanoparticles as colorant are introduced. Recently, methods for producing bimetal nanoparticles such as gold/silver and gold/copper have been developed. These nanoparticles allow colors from yellow to green to be created. These methods and colors they produce are also described in this article.

  5. Crystal Growth of Novel Bimetallic Nikel, Magnesium (Ni3+, Mg2+ Potassium Di Hydrogen Phosphate by Solution Growth and their Characterizations

    Directory of Open Access Journals (Sweden)

    A. Claude

    2006-01-01

    Full Text Available Potassium Di-hydrogen Phosphate (KDP, crystal is a good nonlinear optic material having Second Harmonic Generation property (SHG. These KDP crystal is grown with bimetallic dopants Nikel-Magnesium (Ni3+, Mg2+ to form Nikel-Magnesium Di-hydrogen Phosphate (NMKDP. The grown crystals were analysed for structural and optical characteristics and compared with pure KDP. FTIR analysis explains the inclusion of the metallic impurities which extends the transmission region visibly. High resolution XRD confirms the order of crystallinity of the material which is found to be superior in the pure form than the bimetallic form thereby conforming the inclusion of the bimetals. The conversion efficiency and verification of SHG generation of the grown crystals were also confirmed by Kurtz method.

  6. Detection of biomolecules and bioconjugates by monitoring rotated grating-coupled surface plasmon resonance

    CERN Document Server

    Szalai, Aniko; Somogyi, Aniko; Szenes, Andras; Banhelyi, Balazs; Csapo, Edit; Dekany, Imre; Csendes, Tibor; Csete, Maria

    2016-01-01

    Plasmonic biosensing chips were prepared by fabricating wavelength-scaled dielectric-metal interfacial gratings on thin polycarbonate films covered bimetal layers via two-beam interference laser lithography. Lysozyme (LYZ) biomolecules and gold nanoparticle (AuNP-LYZ) bioconjugates with 1:5 mass ratio were seeded onto the biochip surfaces. Surface plasmon resonance spectroscopy was performed before and after biomolecule seeding in a modified Kretschmann-arrangement by varying the azimuthal and polar angles to optimize the conditions for rotated grating-coupling. The shift of secondary and primary resonance peaks originating from rotated grating-coupling phenomenon was monitored to detect the biomolecule and bioconjugate adherence. Numerical calculations were performed to reproduce the measured reflectance spectra and the resonance peak shifts caused by different biocoverings. Comparison of measurements and calculations proved that monitoring the narrower secondary peaks under optimal rotated-grating coupling ...

  7. Bi-metallic model of the free recovery motion of ion irradiated Ti-rich NiTi shape memory alloy thin films

    International Nuclear Information System (INIS)

    A bi-metal approach is used to model the free recovery motion of ion implanted Ti-rich NiTi sputtered films. For comparison and to validate the model, the thermo-mechanical properties of unirradiated films were explored, using an in-house built dead load tester and micro-tensile machine. There is good agreement between the measured recovery stresses in the unirradiated thin film and those that are predicted by model at the interface between the damage and undamaged layer. However, these stresses are too low to conclude that the loss in reversible motion observed in irradiated films are due to the overload of the damage layer and may result from other processes, such as structural and stress relaxations

  8. Bi-metallic model of the free recovery motion of ion irradiated Ti-rich NiTi shape memory alloy thin films

    Energy Technology Data Exchange (ETDEWEB)

    LaGrange, T.; Gotthardt, R

    2004-12-15

    A bi-metal approach is used to model the free recovery motion of ion implanted Ti-rich NiTi sputtered films. For comparison and to validate the model, the thermo-mechanical properties of unirradiated films were explored, using an in-house built dead load tester and micro-tensile machine. There is good agreement between the measured recovery stresses in the unirradiated thin film and those that are predicted by model at the interface between the damage and undamaged layer. However, these stresses are too low to conclude that the loss in reversible motion observed in irradiated films are due to the overload of the damage layer and may result from other processes, such as structural and stress relaxations.

  9. Impact Factors on Removal of Perchloroethylene with Nano-Ni/Fe Methodology

    Institute of Scientific and Technical Information of China (English)

    LIU Fei; HUANG Yuanying; CUI Weihua

    2006-01-01

    Chlorinated hydrocarbons are widely detected in groundwater, but conventional removal methodologies are not time-and-cost effective. With the development of iron reducing technology in recent years, research on nano-iron and nano-bimetal has become a hot spot. The paper presents the results of impact factors on perchloroethylene (PCE) removal by nano-Ni/Fe method. The data show that the reaction rate of unexposed nano-Ni/Fe is 4 times higher than exposed one; and temperature is one of the important controlling factors. Reaction rate constant KsA increases by 2-3 times with every 10℃ increment of temperature. Within a specific range, higher Ni/Fe ratio favors dechlorination process. When the Ni/Fe is 8%, the dechlorination process reaches the highest rate. Dissoved oxygen in the solution does not favor the degradation of chlorinated hydrocarbons.

  10. Formation of bimetallic nanoalloys by Au coating of size-selected Cu clusters

    International Nuclear Information System (INIS)

    Bimetallic clusters display new characteristics that could not be obtained by varying either the size of pure metallic systems or the composition of bulk bimetals alone. Coating of pre-deposited clusters by vapour deposition is a typical synthesis process of bimetallic clusters. Here, we have demonstrated that hierarchical, gold cluster-decorated copper clusters as well as both heterogeneous and homogeneous Cu–Au bimetallic clusters (4.6 to 10.7 nm) can be prepared by coating pre-deposited, size-selected Cu5000 (4.6 ± 0.2 nm) with Au evaporation at various temperatures. These bimetallic clusters were analyzed by aberration-corrected scanning transmission electron microscopy and associated electron energy loss spectroscopy. The results indicate that the growth of bimetallic clusters is controlled by a competition between nucleation and diffusion of the coating Au atoms.

  11. Design and characterization of thermally actuated bimetallic membranes by Michelson interferometry

    OpenAIRE

    JULIO ENRIQUE DUARTE; FLAVIO HUMBERTO FERNÁNDEZ MORALES; ESTELA MARTIN-BADOSA

    2011-01-01

    En el presente trabajo se describen el diseño y la caracterización de membranas bimetálicas de Al-Si, con actuación térmica. El diseño se realizó empleando el método de los Elementos Finitos y se concentró en optimizar la relación de los espesores de las capas de aluminio y silicio. La defl exión de las membranas se determinó aplicando la técnica del Interferómetro de Michelson. En la etapa experimental se utilizaron membranas cuadradas de 5 mm de lado, con un espesor de 10 mm para el silicio...

  12. Synthesis and Characterization of Optically Active Fractal Seed Mediated Silver Nickel Bimetallic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Joseph Adeyemi Adekoya

    2014-01-01

    Full Text Available The synthesis of new seed mediated AgNi allied bimetallic nanocomposites was successfully carried out by the successive reduction of the metal ions in diethylene glycol, ethylene glycol, glycerol, and pentaerythritol solutions, with concomitant precipitation of Ag/Ni bimetal sols. The optical measurement revealed the existence of distinct band edge with surface plasmon resonance (SPR in the region of 400–425 nm and excitonic emission with maximum peak at 382 nm which were reminiscent of cluster-in-cluster surface enriched bimetallic silver-nickel sols. The morphological characterization by transmission electron microscopy, high resolution transmission electron microscopy, and X-ray diffraction analyses complimented by surface scan using X-ray photoelectron spectroscopy strongly supported the formation of intimately alloyed face-centered silver/nickel nanoclusters.

  13. Overhead lines: materials. Guard conductors and cables; Lignes aeriennes: materiels. Conducteurs et cables de garde

    Energy Technology Data Exchange (ETDEWEB)

    Chanal, A. [Electricite de France (EDF), 75 - Paris (France). Direction de la Production et du Transport; Leveque, J.P. [Electricite de France (EDF), Reseau de Transport d' Electricite, 75 - Paris (France)

    2003-02-01

    This article presents the characteristics of bare cables for the construction of overhead lines. During the last decades, no important change has been made in the choice of conductive materials. The main materials used are: the high purity cold drawn aluminium in bi-metal aluminium-steel cables, and the 'almelec', an aluminium alloy with a reinforced traction resistance. Recently, new conductors with a higher transport capacity and a better temperature resistance have been developed. Another way of research concerns the combination of conductors and composite materials (carbon fibers) but no satisfactory solutions have been obtained so far. A more important evolution concerns the guard cables for high voltage lines which now include telecommunication circuits (optical fibers) for high flow rate transmission of numerical data. The laying out of such cables has been generalized in France in order to supply the overall territory with equivalent and satisfactory performances. (J.S.)

  14. INL DPAH STAAR 2015 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Peterman, Dean Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-15

    Research conducted at the INL has demonstrated the synergistic extraction of americium using solvents comprised of bis(o,o-(trifluoromethyl)phenyl) dithiophosphinic acid (DPAH “1”) and trioctylphosphine oxide (TOPO), butyl bis(2,4,4-trimethylpentyl) phosphinate (BuCy272), or dibutyl butylphosphonate (DBBP). One potential drawback of this separations scheme is that soft metals such as silver, cadmium, or palladium and fission products such as zirconium are well extracted by these solvents. Several potential scrubbing reagents were examined. Of the scrubbing reagents studied, cysteine and methione exhibited some ability to scrub soft metals from the loaded solvent. More conventional scrub reagents such as ammonium fluoride or oxalic acid were not effective. Reagents like Bimet and CDTA were not soluble at the acidities used in these studies. Unfortunately, these results indicate that the identification of effective scrubbing reagents for use in a flowsheet based upon the INL DPAH is going to be very difficult.

  15. One-step preparation of optically transparent Ni-Fe oxide film electrocatalyst for oxygen evolution reaction

    International Nuclear Information System (INIS)

    Graphical abstract: The optically transparent Ni-Fe oxide films are deposited on FTO substrates by one-step reactive magnetron co-sputtering. The optimal electrocatalytic activity for oxygen evolution reaction is achieved at an atomic ratio of Fe/Ni = 3:7, which is a very promising cocatalyst for photoelectrochemical water splitting owing to its optical transparency and high electrochemical activity. Display Omitted -- Abstract: Optically transparent cocatalyst film materials is very desirable for improved photoelectrochemical (PEC) oxygen evolution reaction (OER) over light harvesting photoelectrodes which require the exciting light to irradiate through the cocatalyst side, i.e., front-side illumination. In view of the reaction overpotential at electrode/electrolyte interface, the OER electrocatalysts have been extensively used as cocatalysts for PEC water oxidation on photoanode. In this work, the feasibility of a one-step fabrication of the transparent thin film catalyst for efficient electrochemical OER is investigated. The Ni-Fe bimetal oxide films, ∼ 200 nm in thickness, are used for study. Using a reactive magnetron co-sputtering technique, transparent (> 50% in wavelength range 500-2000 nm) Ni-Fe oxide films with high electrocatalytic activities were successfully prepared at room temperature. Upon optimization, the as-prepared bimetal oxide film with atomic ratio of Fe/Ni = 3:7 demonstrates the lowest overpotential for the OER in aqueous KOH solution, as low as 329 mV at current density of 2 mA cm−2, which is 135 and 108 mV lower than that of as-sputtered FeOx and NiOx thin films, respectively. It appears that this fabrication strategy is very promising to deposit optically transparent cocatalyst films on photoabsorbers for efficient PEC water splitting

  16. Asymmetric AgPd-AuNR heterostructure with enhanced photothermal performance and SERS activity

    Science.gov (United States)

    Zhang, Han; Liu, Zeke; Kang, Xiaolin; Guo, Jun; Ma, Wanli; Cheng, Si

    2016-01-01

    Most as-reported nanostructures through galvanic replacement reactions are still symmetric hollow structures, until now. Asymmetric structures fabricated through a galvanic replacement reaction have been rarely reported. However, asymmetric heterostructures can generally lead to new intriguing properties through asymmetric synergistic coupling. Here, we report a simple synthesis of an asymmetric one-ended AgPd bimetal on Au nanorods (AuNR) by combining a galvanic replacement reaction with an Ostwald ripening process. The morphological evolution from a nanodumbbell to a dandelion structure is thoroughly investigated. The unique asymmetric AgPd-AuNR heterostructures possess the required plasmonic performance and avoid strong damping caused by the poor plasmonic metal Pd, resulting in a superior photothermal heating performance and enhanced SERS sensitivity for in situ monitoring of a catalytic reaction compared with the symmetric counterparts.Most as-reported nanostructures through galvanic replacement reactions are still symmetric hollow structures, until now. Asymmetric structures fabricated through a galvanic replacement reaction have been rarely reported. However, asymmetric heterostructures can generally lead to new intriguing properties through asymmetric synergistic coupling. Here, we report a simple synthesis of an asymmetric one-ended AgPd bimetal on Au nanorods (AuNR) by combining a galvanic replacement reaction with an Ostwald ripening process. The morphological evolution from a nanodumbbell to a dandelion structure is thoroughly investigated. The unique asymmetric AgPd-AuNR heterostructures possess the required plasmonic performance and avoid strong damping caused by the poor plasmonic metal Pd, resulting in a superior photothermal heating performance and enhanced SERS sensitivity for in situ monitoring of a catalytic reaction compared with the symmetric counterparts. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07333b

  17. Thermal modeling and optimization of a thermally matched energy harvester

    Science.gov (United States)

    Boughaleb, J.; Arnaud, A.; Cottinet, P. J.; Monfray, S.; Gelenne, P.; Kermel, P.; Quenard, S.; Boeuf, F.; Guyomar, D.; Skotnicki, T.

    2015-08-01

    The interest in energy harvesting devices has grown with the development of wireless sensors requiring small amounts of energy to function. The present article addresses the thermal investigation of a coupled piezoelectric and bimetal-based heat engine. The thermal energy harvester in question converts low-grade heat flows into electrical charges by achieving a two-step conversion mechanism for which the key point is the ability to maintain a significant thermal gradient without any heat sink. Many studies have previously focused on the electrical properties of this innovative device for energy harvesting but until now, no thermal modeling has been able to describe the device specificities or improve its thermal performances. The research reported in this paper focuses on the modeling of the harvester using an equivalent electrical circuit approach. It is shown that the knowledge of the thermal properties inside the device and a good comprehension of its heat exchange with the surrounding play a key role in the optimization procedure. To validate the thermal modeling, finite element analyses as well as experimental measurements on a hot plate were carried out and the techniques were compared. The proposed model provided a practical guideline for improving the generator design to obtain a thermally matched energy harvester that can function over a wide range of hot source temperatures for the same bimetal. A direct application of this study has been implemented on scaled structures to maintain an important temperature difference between the cold surface and the hot reservoir. Using the equations of the thermal model, predictions of the thermal properties were evaluated depending on the scaling factor and solutions for future thermal improvements are presented.

  18. Investigation of annealing treatment on the interfacial properties of explosive-welded Al/Cu/Al multilayer

    International Nuclear Information System (INIS)

    Highlights: ► We studied explosive-welded Al/Cu/Al multilayer. ► We investigated heat treatment influence on the bond properties of Al/Cu/Al. ► Intermetallic compounds were studied using the SEM, OM and EDS analysis. ► Variations of hardness in the thickness were investigated using micro-hardness. ► Intermetallic phases such as AlCu3 and Al2C create at the interface of Al/Cu/Al. -- Abstract: In this study, an Al/Cu/Al multilayer sheet was fabricated by explosive welding process and the effects of annealing temperature on the interfacial properties of explosively bonded Al/Cu bimetal have been investigated. For this purpose, hardness changes along the thickness of the samples have been measured, and the thickness and type of intermetallic compounds formed at the joining interface have been explored by means of optical microscopy (OM), scanning electron microscopy (SEM) and also energy dispersive spectroscopy (EDS). The obtained results indicate that, with the increase of the annealing temperature, the thickness of intermetallic compounds has increased and the amount of hardness along the thickness of the joining interface has diminished. In the annealed sample at 400 °C for 30 min, it was observed that intermetallic layers have formed at the interface of Al/Cu bimetals. These layers consist of the intermetallic compounds AlCu3, Al2Cu and AlCu, and their thickness gets to about 5 μm at some points. The examinations performed by the SEM, following the Vickers micro-hardness test, indicated the existence of a number of microcracks at the top and bottom interface of the sample annealed at 400 °C. This shows the formation of brittle intermetallic compounds at the joining interface, and also indicates the low ductility of these compounds.

  19. Quasi-Instantaneous Bacterial Inactivation on Cu-Ag Nanoparticulate 3D Catheters in the Dark and Under Light: Mechanism and Dynamics.

    Science.gov (United States)

    Rtimi, Sami; Sanjines, Rosendo; Pulgarin, Cesar; Kiwi, John

    2016-01-13

    The first evidence for Cu-Ag (50%/50%) nanoparticulate hybrid coatings is presented leading to a complete and almost instantaneous bacterial inactivation in the dark (≤5 min). Dark bacterial inactivation times on Cu-Ag (50%/50%) were observed to coincide with the times required by actinic light irradiation. This provides the evidence that the bimetal Cu-Ag driven inactivation predominates over a CuO/Cu2O and Ag2O oxides inducing a semiconductor driven behavior. Cu- or Ag-coated polyurethane (PU) catheters led to bacterial inactivation needing about ∼30 min. The accelerated bacterial inactivation by Cu-Ag coated on 3D catheters sputtered was investigated in a detailed way. The release of Cu/Ag ions during bacterial inactivation was followed by inductively coupled plasma mass-spectrometry (ICP-MS) and the amount of Cu and Ag-ions released were below the cytotoxicity levels permitted by the sanitary regulations. By stereomicroscopy the amount of live/dead cells were followed during the bacterial inactivation time. By Fourier transform infrared spectroscopy (FTIR), the systematic shift of the -(CH2) band stretching of the outer lipo-polysaccharide bilayer (LPS) was followed to monitor the changes leading to cell lysis. A hydrophobic to hydrophilic transformation of the Cu-Ag PU catheter surface under light was observed within 30 min followed concomitantly to a longer back transformation to the hydrophobic initial state in the dark. Physical insight is provided for the superior performance of Cu-Ag films compared to Cu or Ag films in view of the drastic acceleration of the bacterial inactivation observed on bimetal Cu-Ag films coating PU catheters. A mechanism of bacterial inactivation is suggested that is consistent with the findings reported in this study. PMID:26699928

  20. Effect of Ag/Au bilayer assisted etching on the strongly enhanced photoluminescence and visible light photocatalysis by Si nanowire arrays.

    Science.gov (United States)

    Ghosh, Ramesh; Imakita, Kenji; Fujii, Minoru; Giri, P K

    2016-03-01

    We report on the strongly enhanced photoluminescence (PL) and visible light photocatalysis by arrays of vertically aligned single crystalline Si nanowires (NWs) grown by Ag/Au bilayer assisted etching. High resolution FESEM and TEM imaging reveals that the Si NWs are decorated with ultra-small size arbitrary shaped Si nanocrystals (NCs) due to the lateral etching of the NWs. A strong broad band and tunable visible to near-infrared (NIR) photoluminescence (PL) in the range 1.3-2.4 eV are observed for these Si NWs/NCs at room temperature, depending on the etching conditions. Our studies reveal that the visible-NIR PL intensity is about two orders of magnitude higher and it exhibits faster decay dynamics in the bilayer assisted etching case as compared to the Ag or Au single layer etching case. The enhanced PL in the bimetal case is attributed to the longer length and higher density of the Si NWs/NCs, surface plasmon resonance enhanced absorption by residual bimetal NPs and the enhanced radiative recombination rate. Studies on the time evolution of PL spectral features with laser exposure under ambient conditions and laser power dependence reveal that both the quantum confinement of carriers in Si NCs and the nonbridging oxygen hole defects in the SiOx layer contribute to the tunable PL. Interestingly, Si NWs grown by Ag/Au bilayer assisted etching exhibit enhanced photocatalytic degradation of methylene blue in comparison to Si NWs grown by single layer Ag or Au assisted etching. The Schottky barrier present between bimetallic NPs and nanoporous Si NWs with Si-H bonds facilitates the photocatalytic activity by efficient separation of photogenerated e-h pairs. Our results demonstrate the superiority of the Si NW array grown by bilayer assisted etching for their cutting edge applications in optoelectronics and environmental cleaning. PMID:26907170

  1. Synthesis, characterization and visible light photocatalytic activity of Cr 3+ , Ce 3+ and N co-doped TiO 2 for the degradation of humic acid

    KAUST Repository

    Rashid, S. G.

    2015-01-01

    The synthesis, characterization and photocatalytic activity of Cr3+ and Ce3+ co-doped TiON (N-doped TiO2) for the degradation of humic acid with exposure to visible light is reported. The synthesized bimetal (Cr3+ + Ce3+) modified TiON (Cr-Ce/TiON), with an evaluated bandgap of 2.1 eV, exhibited an enhanced spectral response in the visible region as compared to pure and Ce3+ doped TiON (Ce/TiON). The XRD analysis revealed the insertion of Cr3+ and Ce3+ in the crystal lattice along with Ti4+ and N that resulted in the formation of a strained TiON anatase structure with an average crystallite size of ∼10 nm. Raman analysis also supported the formation of stressed rigid structures after bimetal doping. HRTEM confirmed the homogeneous distribution of both the doped metallic components in the crystal lattice of TiON without the formation of surface oxides of either Cr3+ or Ce3+. Electron energy loss spectroscopy (EELS) analysis revealed no change in the oxidation of either Cr or Ce during the synthesis. The synthesized Cr-Ce/TiON catalyst exhibited appreciable photocatalytic activity for the degradation of humic acid on exposure to visible light. Additionally, a noticeable mineralization of carbon rich humic acid was also witnessed. The photocatalytic activity of the synthesized catalyst was compared with pristine and Ce3+ doped TiON. © The Royal Society of Chemistry 2015.

  2. High-performance PdRu bimetallic catalyst supported on mesoporous silica nanoparticles for phenol hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chao [The Key Laboratory of Fuel Cell Technology of Guangdong Province and The Key Laboratory for New Energy of Guangdong Universities, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China); Yang, Xu [Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou (China); Yang, Hui; Huang, Peiyan; Song, Huiyu [The Key Laboratory of Fuel Cell Technology of Guangdong Province and The Key Laboratory for New Energy of Guangdong Universities, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China); Liao, Shijun, E-mail: chsjliao@scut.edu.cn [The Key Laboratory of Fuel Cell Technology of Guangdong Province and The Key Laboratory for New Energy of Guangdong Universities, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China)

    2014-10-01

    Graphical abstract: The addition of Ru could significantly improve the performance of the mesoporous silica nanoparticles supported PdRu/MSN catalyst, which showed over 5 times higher mass activity than the mono-Pd/MSN towards the liquid-phase hydrogenation of phenol. The improved dispersion and the electronic interaction contributed to the enhanced catalytic activity for the catalyst towards phenol hydrogenation. - Highlights: • PdRu bimetal catalyst supported on mesoporous silica nanoparticles was prepared. • The average sizeof PdRu alloy is smaller than that of mono-Pd. • The addition of Ru to Pd modulates the electronic properties between Pd and Ru. • PdRu/MSN catalyst shows superior activity on phenol hydrogenation than Pd/MSN. • PdRu/MSN catalyst shows good selectivity for cyclohexanol to some extent. - Abstract: A high-performance PdRu bimetallic catalyst supported on mesoporous silica nanoparticles (MSN), PdRu/MSN, was prepared by a facile impregnation–hydrogen reduction method. It was found that PdRu/MSN showed 5 times higher activity than that of Pd/MSN towards the liquid-phase hydrogenation of phenol. The catalysts were characterized comprehensively by multiple techniques, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and hydrogen temperature program reduction (TPR). It was revealed that adding Ru could effectively improve the Pd dispersion and promote the electronic interaction between the Pd and Ru, both of which contribute to enhancing the catalytic activity.

  3. A Phenomenological Study on the Synergistic Role of Precious Metals in the Steam Reforming of Logistic Fuels on Trimetal-Supported Catalysts

    Directory of Open Access Journals (Sweden)

    Abdul-Majeed Azad

    2010-01-01

    Full Text Available Fuel processors are required to convert sulfur-laden logistic fuels (jet fuels, diesel, and coal into fuel cell quality hydrogen-rich reformate with little or no sulfur for extended periods. Sulfur poisons and deactivates the reforming catalyst, therefore, sulfur-tolerant catalysts ought to be developed. In this paper, the development, characterization, and evaluation of a series of nanoscale ceria-supported reforming catalysts containing three noble metals in low concentration (1 wt% ≤ total metal loading ≤ 1.33 wt% for the steam-reforming of kerosene (a JP-8 surrogate are reported. Their performance is quantified in terms of H2 yield, tolerance towards sulfur in the fuel, and the on-stream stability and compared with that of monometal and bimetal analogs under identical conditions. Due to the inherent cooperative synergy, a trimetal catalyst was found far superior to its mono- and bimetallic analog containing same amount of the precious metal loading in terms of quality of the reformate (measured by H2 level in steady-state as well as the catalyst longevity on-stream prior to deactivation. At the same time a mechanistic correlation between the distinct role of a given precious metal and the extent of its loading in each of the formulations and quality of the corresponding desulfurized H2-rich reformate was discovered.

  4. Promoting effect of Ir on the catalytic property of Ru/ZnO catalysts for selective hydrogenation of crotonaldehyde

    International Nuclear Information System (INIS)

    A series of ZnO supported Ru–Ir bimetal catalysts were prepared and tested for vapor-phase selective hydrogenation of crotonaldehyde. The addition of Ir could effectively promote the catalytic performance, especially the catalyst stability. A Ru–0.5Ir/ZnO catalyst showed the highest activity (a conversion of 63.3%) and selectivity to crotyl alcohol (94.4%) after 30 h reaction. The enhanced stability was attributed to the modified electronic property of Ru by the formation of RuIr alloy as the X-ray photoelectron spectroscopy results showed charge transfer from Ru to Ir, as well as the weakened surface acidity in the Ru–Ir/ZnO catalyst as evidenced by NH3 temperature-programmed desorption technique. Besides, the deactivation of the catalysts was due to the strong chemisorption of CO on the metal surface via decarbonylation reaction and deposition of organic compounds on the catalyst surface, which was characterized by CO poisoning experiment, CO temperature-programmed desorption and temperature-programmed oxidation methods.

  5. Assemblies of silicate sol-gel matrix encapsulated core/shell Au/Ag nanoparticles: interparticles surface plasmon coupling

    Energy Technology Data Exchange (ETDEWEB)

    Manivannan, Shanmugam; Ramaraj, Ramasamy, E-mail: ramarajr@yahoo.com [Madurai Kamaraj University, Centre for Photoelectrochemistry, School of Chemistry (India)

    2012-06-15

    Cluster-like assemblies of bimetal core/shell Au/Ag nanoparticles were prepared. The Ag shell was deposited on the preformed Au nanoparticles using two different types of preformed Au nanoparticles in the presence of EDAS silane monomer, one stabilized by citrate and other by {beta}-cyclodextrin. The Ag shell was deposited on the preformed Au nanoparticles by the reduction of Ag{sup +} ions by {beta}-cyclodextrin and EDAS silane composite. Interestingly, productive Ag shell deposition occurred only on the {beta}-cyclodextrin-stabilized Au nanoparticles and led to the assembly formation, whereas aggregation occurred with the citrate-stabilized Au nanoparticles. The average particle size of the core/shell Au/Ag nanoparticles was found to be 6.5 nm. Spectral features of this assembly of core/shell Au/Ag nanoparticles resembled the longitudinal surface plasmon resonance behavior of Au nanorod-like structures arising from the interparticles surface plasmon coupling. The assemblies so prepared were characterized by uv-vis absorption spectroscopy and high-resolution transmission electron microscopy.Graphical Abstract.

  6. Meat Quality Assessment by Electronic Nose (Machine Olfaction Technology

    Directory of Open Access Journals (Sweden)

    Sundar Balasubramanian

    2009-07-01

    Full Text Available Over the last twenty years, newly developed chemical sensor systems (so called “electronic noses” have made odor analyses possible. These systems involve various types of electronic chemical gas sensors with partial specificity, as well as suitable statistical methods enabling the recognition of complex odors. As commercial instruments have become available, a substantial increase in research into the application of electronic noses in the evaluation of volatile compounds in food, cosmetic and other items of everyday life is observed. At present, the commercial gas sensor technologies comprise metal oxide semiconductors, metal oxide semiconductor field effect transistors, organic conducting polymers, and piezoelectric crystal sensors. Further sensors based on fibreoptic, electrochemical and bi-metal principles are still in the developmental stage. Statistical analysis techniques range from simple graphical evaluation to multivariate analysis such as artificial neural network and radial basis function. The introduction of electronic noses into the area of food is envisaged for quality control, process monitoring, freshness evaluation, shelf-life investigation and authenticity assessment. Considerable work has already been carried out on meat, grains, coffee, mushrooms, cheese, sugar, fish, beer and other beverages, as well as on the odor quality evaluation of food packaging material. This paper describes the applications of these systems for meat quality assessment, where fast detection methods are essential for appropriate product management. The results suggest the possibility of using this new technology in meat handling.

  7. Sintering of biocompatible P/M Co-Cr-Mo alloy (F-75) for fabrication of porosity-graded composite structures

    International Nuclear Information System (INIS)

    Manufacturing of complex-shaped bimetals utilizing two-color powder injection molding (2C-PIM) and three-dimensional printing (3DP) processes, which basically involve sintering of a powder/binder mixture, has been attracted a great interest. This article addresses sintering of biocompatible Co-Cr-Mo alloy for manufacturing stepwise porosity-graded composite structures. Such composite structures provide strength at the core and a porous layer for the tissue growth. To evaluate the process, two grades of gas atomized Co-Cr-Mo powder with an average particle size of 19 and 63 μm were used. Isothermal and non-isothermal sintering behavior of the loose powders under hydrogen and argon atmospheres, which is a simulated condition of 2C-PIM and 3DP processes after de-binding, was studied. Microstructural characteristics of the sintered specimens were evaluated. It was found that an intermediate sintering temperature of 1280 deg. C in argon can be used for manufacturing of the porosity-graded composite layers, i.e., a relatively dense core (5% porosity) with a porous layer (33% porosity) can be produced. A hip-joint with a core/shell structure was produced as a case study

  8. 1996 outstanding facts

    International Nuclear Information System (INIS)

    This progress report of the Direction of Studies and Research (DER) of Electricite de France (EdF) reports on some outstanding studies carried out during the year 1996 and concerning: new applications of electric power (thermal comfort, heating floors, building diagnosis, energy management, customers communicating interfaces, services, air conditioning, off-peak tariffs, power demand mastery in the industry, infrared dryers for paper industry); production means (automatic systems for nuclear power plants operation, management of reactors shutdown schedules for refuelling operations, optimization of fuel loading patterns for PWRs, neutronic and thermohydraulic computer codes for steam pipes rupture accidents, thermo-hydraulic modeling of the confinement building during post-accidental situation, 3D numerical simulation of overpressures inside reactor valves and of vortex and two-phase flow inside auxiliary pipes, control of vibrating fatigue of pipe nozzles, qualification of the adjustable speed drives of the Gravelines' cooling pumps, 3D analysis of new steam turbine designs, identification of bi-metal welding surface defects, a simple method for the evaluation of in-service fatigue of components, the probabilistic dimensioning of safety coefficients, the modeling of thermo-hydro-mechanical coupling of geo-materials for radioactive wastes storage, the supply of isolated sites using renewable energies); environment protection (batteries for electric-powered vehicles, modeling of atmospheric reactive flows, chlorination of the Dampierre's cooling circuits for pathogen amoebas elimination, in-situ treatment of PCBs isolated transformers); and development and exploitation of materials for power networks. (J.S.)

  9. Catalytic De/hydrogenation in Mg by co-doped Ni and VO{sub x} on active carbon: extremely fast kinetics at low temperatures and high hydrogen capacity

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Yi; Cheng, Lina [ARC Centre of Excellence for Functional Nanomaterials, University of Queensland, Brisbane (Australia); School of Mechanical and Mining Engineering, University of Queensland, Brisbane (Australia); Pan, Nan [Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei (China); Zou, Jin [School of Mechanical and Mining Engineering, University of Queensland, Brisbane (Australia); Lu, Gaoqing (Max) [ARC Centre of Excellence for Functional Nanomaterials, University of Queensland, Brisbane (Australia); Yao, Xiangdong [ARC Centre of Excellence for Functional Nanomaterials, University of Queensland, Brisbane (Australia); Queensland Micro- and Nanotechnology Centre (QMNC), Griffith University, Brisbane (Australia)

    2011-05-15

    A multi-component catalyst Ni-VO{sub x}/AC (VO{sub x} is comprised of V{sub 2}O{sub 5} and VO{sub 2}, x = 2.18) was synthesized by a wet impregnation method. The synthesized Ni-VO{sub x}/AC shows a superior catalytic effect on de/hydrogenation of Mg. The MgH{sub 2}+Ni-VO{sub x}/AC composites can absorb 6.2 wt.-% hydrogen within only 1 min at 150 C under a hydrogen pressure of 2 MPa and desorb 6.5 wt.-% hydrogen within 10 min at 300 C under an initial hydrogen pressure of 1 KPa, which overcomes a critical barrier for practical use of Mg as a hydrogen storage material. A significant decrease of activation energy (E{sub a}) indicates that Ni-VO{sub x}/AC catalyst is highly efficient for Mg de/hydrogenation, which may be ascribed to the synergistic effect of bimetals (metal oxides) and nanocarbon. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Effects of the inner mould material on the aluminium–316L stainless steel explosive clad pipe

    International Nuclear Information System (INIS)

    Highlights: ► Different mould materials were adopted to evaluate the effect of the constraint on the clad quality. ► The interface characteristics of clad pipe were analyzed for the different clad pipe. ► The clad pipes possess excellent bonding quality. - Abstract: The clad pipe played an important part in the pipeline system of the nuclear power industry. To prepare the clad pipe with even macrosize and excellent bonding quality, in this work, different mould materials were adopted to evaluate the effect of the constraint on the clad quality of the bimetal pipe prepared by explosive cladding. The experiment results indicated that, the dimension uniformity and bonding interface of clad pipe were poor by using low melting point alloy as mould material; the local bulge or the cracking of the clad pipe existed when the SiC powder was utilized. When the steel mould was adopted, the outer diameter of the clad pipe was uniform from head to tail. In addition, the metallurgical bonding was formed. Furthermore, the results of shear test, bending test and flattening test showed that the bonding quality was excellent. Therefore, the Al–316L SS clad pipe could endure the second plastic forming

  11. Mg-AI Mixed Oxides Supported Bimetallic Au-Pd Nanoparticles with Superior Catalytic Properties in Aerobic Oxidation of Benzyl Alcohol and Glycerol

    Institute of Scientific and Technical Information of China (English)

    王亮; 张伟; 曾尚景; 苏党生; 孟祥举; 肖丰收

    2012-01-01

    Nano-sized Au and Pd catalysts are favorable for oxidations with molecular oxygen, and the preparation of this kind of nanoparticles with high catalytic activities is strongly desirable. We report a successful synthesis of bimetal- lic Au-Pd nanoparticles with rich edge and comer sites on unique support of Mg-AI mixed oxides (Au-Pd/MAO), which are favorable for producing metal nanoparticles with high degree of coordinative unsaturation of metal atoms The systematic microscopic characterizations confirm the bimetallic Au-Pd nanoparticles are present as Au-Pd alloy The irregular shape of the bimetallic nanoparticles are directly observed in HRTEM images. As we expected, Au-Pd/MAO gives very excellent catalytic performances in the aerobic oxidation of benzyl alcohol and glycerol. For example, Au-Pd/MAO shows very high TOF of 91000 h i at 433 K with molecular oxygen at air pressure in solvent-free oxidation of benzyl alcohol; this catalyst also shows relatively high selectivity for tartronic acid (TA- RAC, 36.6%) at high conversion (98.5%) in aerobic oxidation of glycerol. The superior catalytic properties of Au-Pd/MAO would be potentially important tbr production of fine chemicals.

  12. Heat-conducting calorimeter for measuring flux density of ionizing radiation and technique for its calorimetric cell fabrication

    International Nuclear Information System (INIS)

    A heat-conducting calorimeter to determine ionizing radiation flux density has been described. The calorimeter contains an absorbing radiation sample placed inside diathermal calorimetric cell. The cell presents an auxiliary wall in the form of a battery of galvanic thermocouples oined in series, which are in thermal contact with the sample. To decrease the calorimeter inertia, its thermal battery is fabricated in the form of a thin-walled cylindrical cover, shaped like a trapezium cut along spiral line and consisting of alternating mono- and bimetal foil parts with transition points in the middle of the trapezium bases. The way of calorimetric cell obtaining by means of galvanic deposition of couple thermoelectric material per one of the branches of every element in thermal battery is also described. Efficiency of the heat-conducting calorimeter suggested and the way of its calorimetric cell obtaining is conditioned by the device universal character and simplicity of fabrication technique of any typical dimensions of the calorimeter, by the possibility to obtain thermosensitive element of the calorimeter in one technological cycle of galvanic deposition as well as by simplification of fabrication technique and calorimeter assembling

  13. Sintering of biocompatible P/M Co-Cr-Mo alloy (F-75) for fabrication of porosity-graded composite structures

    Energy Technology Data Exchange (ETDEWEB)

    Dourandish, M. [Department of Material Science and Engineering, Sharif University of Technology, P.O. Box 11365-9466, Azadi Avenue, 14588 Tehran (Iran, Islamic Republic of); Godlinski, D. [Fraunhofer Institute for Manufacturing Technology and Applied Materials Research (IFAM), Wiener Str. 12, 28359 Bremen (Germany); Simchi, A. [Department of Material Science and Engineering, Sharif University of Technology, P.O. Box 11365-9466, Azadi Avenue, 14588 Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P.O. Box 11365-9466, Azadi Avenue, 14588 Tehran (Iran, Islamic Republic of)], E-mail: simchi@sharif.edu; Firouzdor, V. [Department of Material Science and Engineering, Sharif University of Technology, P.O. Box 11365-9466, Azadi Avenue, 14588 Tehran (Iran, Islamic Republic of)

    2008-01-15

    Manufacturing of complex-shaped bimetals utilizing two-color powder injection molding (2C-PIM) and three-dimensional printing (3DP) processes, which basically involve sintering of a powder/binder mixture, has been attracted a great interest. This article addresses sintering of biocompatible Co-Cr-Mo alloy for manufacturing stepwise porosity-graded composite structures. Such composite structures provide strength at the core and a porous layer for the tissue growth. To evaluate the process, two grades of gas atomized Co-Cr-Mo powder with an average particle size of 19 and 63 {mu}m were used. Isothermal and non-isothermal sintering behavior of the loose powders under hydrogen and argon atmospheres, which is a simulated condition of 2C-PIM and 3DP processes after de-binding, was studied. Microstructural characteristics of the sintered specimens were evaluated. It was found that an intermediate sintering temperature of 1280 deg. C in argon can be used for manufacturing of the porosity-graded composite layers, i.e., a relatively dense core (5% porosity) with a porous layer (33% porosity) can be produced. A hip-joint with a core/shell structure was produced as a case study.

  14. Bimetallic Au/Pd catalyzed aerobic oxidation of alcohols in the poly(ethylene glycol)/CO2 system

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Bimetallic Au/Pd nanoparticles were prepared and used to catalyze oxidation of alcohols in the poly(ethylene glycol) (PEG)/CO2 biphasic system using O2 as the oxidant without adding any base.The catalytic activity of Au/Pd bimetal with different mole ratios was studied using benzyl alcohol as the substrate.It was found that bimetallic Au/Pd nanoparticles with Au:Pd=1:3.5 had higher catalytic activity than monometallic Au,Pd and the bimetallic Au/Pd nanoparticles with other molar ratios.The effect of CO2 pressure on the oxidation of benzyl alcohol and 1-phenylethanol in PEG/CO2 was investigated.It was demonstrated that CO2 pressure could be used to tune the conversion and selectivity of the reactions effectively.α,β-Unsaturated alcohols were also studied and found to be more reactive than benzyl alcohol and 1-phenylethanol.Recycling experiments showed that the Au/Pd/PEG/CO2 catalytic system could be recycled at least four times without reducing the activity.In addition,the catalytic system is clean and the products can be separated easily.

  15. Label-Free Quantitative Immunoassay of Fibrinogen in Alzheimer Disease Patient Plasma Using Fiber Optical Surface Plasmon Resonance

    Science.gov (United States)

    Kim, Jisoo; Kim, SeJin; Nguyen, Tan Tai; Lee, Renee; Li, Tiehua; Yun, Changhyun; Ham, Youngeun; An, Seong Soo A.; Ju, Heongkyu

    2016-05-01

    We present a real-time quantitative immunoassay to detect fibrinogen in the blood plasma of Alzheimer's disease patients using multimode fiber optical sensors in which surface plasmon resonance (SPR) was employed. Nanometer-thick bimetals including silver and aluminum were coated onto the core surface of the clad-free part (5 cm long) of the fiber for SPR excitation at the He-Ne laser wavelength of 632.8 nm. The histidine-tagged peptide was then coated on the metal surface to immobilize the fibrinogen antibody for the selective capture of fibrinogen among the proteins in the patient blood plasma. The SPR fiber optical sensor enabled quantitative detection of concentrations of fibrinogen from the different human patient blood at a detection limit of ˜20 ng/ml. We also observed a correlation in the fibrinogen concentration measurement between enzyme-linked immunosorbent assay and our SPR fiber-based sensors. This suggests that the presented SPR fiber-based sensors that do not rely on the use of labels such as fluorophores can be used for a real-time quantitative assay of a specific protein such as fibrinogen in a human blood that is known to contain many other kinds of proteins together.

  16. Submonolayer-Pt-Coated Ultrathin Au Nanowires and Their Self-Organized Nanoporous Film: SERS and Catalysis Active Substrates for Operando SERS Monitoring of Catalytic Reactions.

    Science.gov (United States)

    Liu, Rui; Liu, Jing-Fu; Zhang, Zong-Mian; Zhang, Li-Qiang; Sun, Jie-Fang; Sun, Meng-Tao; Jiang, Gui-Bin

    2014-03-20

    For their unique properties, core-shell bimetal nanostructures are currently of immense interest. However, their synthesis is not a trivial work, and most works have been conducted on nanoparticles. We report herein a new synthetic tactic for submonolyer-Pt coated ultrathin Au nanowires (NWs). Besides providing a strong electromagnetic field for Raman signal enhancing, the underlined Au NWs markedly enhanced the catalytic activity of Pt atoms through increasing their dispersity and altering their electronic state. The integration of excellent SERS and high catalytic activity within Au@Pt NWs enable it work as platform for catalyzed reaction study. As a proof of principle, the self-organized Au@Pt NWs thin film is employed in operando SERS monitoring of the p-nitrothiophenol reduction process. In addition to providing kinetic data for structure-activity relationship study, the azo-intermidate independent path is also directly witnessed. This synthetic tactic can be extended to other metals, thus offering a general approach to modulate the physical/chemical properties of both core and shell metals. PMID:26270975

  17. Advances in hexitol and ethylene glycol production by one-pot hydrolytic hydrogenation and hydrogenolysis of cellulose

    International Nuclear Information System (INIS)

    In this review, recent advances in the one-pot hydrolytic hydrogenation and hydrogenolysis of cellulose to value-added polyols, including hexitols (sorbitol, mannitol, and isosorbide) and 1,2-alkanediols (ethylene glycol and 1,2-propylene glycol), are summarized. Methods for the generation of H+ in the first step of cellulose hydrolysis to form intermediate sugars, such as the use of soluble acids (mineral acids and heteropoly acids) and H+ produced in situ from functional supports and H2 dissociation, are classified and analyzed, considering its combination with active metals for the subsequent hydrogenation or hydrogenolysis of sugars to polyols. The interaction of non-noble metals such as nickel, bimetals, and tungsten with support materials in the catalytic conversion of intermediate sugars to hexitols and ethylene glycol is reviewed. The corresponding reaction pathways and mechanisms are discussed, including the conversion process using basic supports and solution conditions. Major challenges and promising routes are also suggested for the future development of the chemocatalytic conversion of cellulose. - Highlights: • Advances in the one-pot hydrolytic hydrogenation/hydrogenolysis of cellulose are summarized. • The interaction of non-noble metals with support materials for cellulose conversion is reviewed. • Method for the generation of in situ H+ and effects of the acidic groups on supports are discussed. • Incomplete identification of intermediates/products causes mechanism complications. • Efficient conversion, separation and purification are other concerns for cellulose degrading

  18. Optimized exposure control in digital mammography

    Science.gov (United States)

    Shramchenko, Nataliya; Blin, Philippe; Mathey, Claude; Klausz, Remy

    2004-05-01

    A method for the determination of optimal operating points of digital mammography systems is described. The digital mammography equipment uses a flat panel detector and a bi-metal molybdenum/rhodium x-ray tube. An operating point is defined by the selection of the x-ray tube target material, x-ray filtration, kVp and detector entrance dose. Breast thickness and composition are estimated from a low dose pre-exposure, then used to index tables containing sets of operating points. The operating points are determined using a model of the image chain, which computes contrast to noise ratio (CNR) and average glandular dose (AGD) for all possible exposure conditions and breast thickness and composition combinations. The selected operating points are those which provide the required CNR for the lowest AGD. An AGD reduction of 30% to 50% can be achieved for comparable Image Quality, relative to current operating points. Resulting from the optimization process, the rhodium target is used in more than 75% of cases. Measurements of CNR and AGD have been performed on various tissue equivalent materials with good agreement between calculated and measured values. The proposed method provides full Image Quality benefit of digital mammography while minimizing dose to patients in a controlled and predictive way.

  19. Rapid Degradation and High Renal Clearance of Cu3BiS3 Nanodots for Efficient Cancer Diagnosis and Photothermal Therapy in Vivo.

    Science.gov (United States)

    Liu, Jing; Wang, Pengyang; Zhang, Xiao; Wang, Liming; Wang, Dongliang; Gu, Zhanjun; Tang, Jinglong; Guo, Mengyu; Cao, Mingjing; Zhou, Huige; Liu, Ying; Chen, Chunying

    2016-04-26

    A key challenge for the use of inorganic nanomedicines in clinical applications is their long-term accumulation in internal organs, which raises the common concern of the risk of adverse effects and inflammatory responses. It is thus necessary to rationally design inorganic nanomaterials with proper accumulation and clearance mechanism in vivo. Herein, we prepared ultrasmall Cu3BiS3 nanodots (NDs) as a single-phased ternary bimetal sulfide for photothermal cancer therapy guided by multispectral optoacoustic tomography (MSOT) and X-ray computed tomography (CT) due to bismuth's excellent X-ray attenuation coefficient. We then monitored and investigated their absorption, distribution, metabolism, and excretion. We also used CT imaging to demonstrate that Cu3BiS3 NDs can be quickly removed through renal clearance, which may be related to their small size, rapid chemical transformation, and degradation in an acidic lysosomal environment as characterized by synchrotron radiation-based X-ray absorption near-edge structure spectroscopy. These results reveal that Cu3BiS3 NDs act as a simple but powerful "theranostic" nanoplatform for MSOT/CT imaging-guided tumor ablation with excellent metabolism and rapid clearance that will improve safety for clinical applications in the future. PMID:27014806

  20. A study on atomic diffusion behaviours in an Al-Mg compound casting process

    International Nuclear Information System (INIS)

    Al and Mg alloys are main lightweight alloys of research interest and they both have superb material properties, i.e., low density and high specific strength, etc. Being different from Al alloys, the corrosion of Mg alloys is much more difficult to control. Therefore to combine merits of these two lightweight alloys as a composite-like structure is an ideal solution through using Al alloys as a protective layer for Mg alloys. Compound casting is a realistic technique to manufacture such a bi-metal structure. In this study, a compound casting technique is employed to fabricate bi-layered samples using Al and Mg and then the samples are analysed using electron probe micro-analyzer (EPMA) to determine diffusion behaviours between Al and Mg. The diffusion mechanism and behaviours between Al and Mg are studied numerically at atomic scale using molecular dynamics (MD) and parametric studies are conducted to find out influences of ambient temperature and pressure on the diffusion behaviours between Al and Mg. The results obtained clearly show the effectiveness of the compound casting process to increase the diffusion between Al and Mg and thus create the Al-base protection layer for Mg

  1. Chemical interactions in multimetal/zeolite catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Sachtler, W.M.H.

    1992-02-07

    Mechanistic explanations have been found for the migration of atoms and ions through the zeolite channels leading to specific distribution of ions and the metal clusters. In this report, we summarize the state of understanding attained on a number of topics in the area of mono- and multimetal/zeolite systems, to which our recent research has made significant contributions. The following topics are discussed: (1) Formation of isolated metal atoms in sodalite cages; (2) differences of metal/zeolite systems prepared by ion reduction in channels or via isolated atoms; (3) rejuvenation of Pd/NaY and Pd/HY catalysts by oxidative redispersion of the metal; (4) formation of mono- or bimetal particles in zeolites by programmed reductive decomposition of volatile metal complexes; (5) cation-cation interaction as a cause of enhanced reducibility; (6) formation of palladium carbonyl clusters in supercages; (7) enhanced catalytic activity of metal particle-proton complexes for hydrocarbon conversion reactions; (8) stereoselectivity of catalytic reactions due to geometric constraints of particles in cages.

  2. Dynamic failure in two-phase materials

    Science.gov (United States)

    Fensin, S. J.; Walker, E. K.; Cerreta, E. K.; Trujillo, C. P.; Martinez, D. T.; Gray, G. T.

    2015-12-01

    Previous experimental research has shown that microstructural features such as interfaces, inclusions, vacancies, and heterogeneities can all act as void nucleation sites. However, it is not well understood how important these interfaces are to damage evolution and failure as a function of the surrounding parent materials. In this work, we present results on three different polycrystalline materials: (1) Cu, (2) Cu-24 wt. %Ag, and (3) Cu-15 wt. %Nb which were studied to probe the influence of bi-metal interfaces on void nucleation and growth. These materials were chosen due to the range of difference in structure and bulk properties between the two phases. The initial results suggest that when there are significant differences between the bulk properties (for example: stacking fault energy, melting temperature, etc.) the type of interface between the two parent materials does not principally control the damage nucleation and growth process. Rather, it is the "weaker" material that dictates the dynamic spall strength of the overall two-phase material.

  3. High performance surface plasmon sensors: Simulations and measurements

    Science.gov (United States)

    Tiwari, Kunal; Sharma, Suresh C.; Hozhabri, Nader

    2015-09-01

    Through computer simulations and surface plasmon resonance (SPR) measurements, we establish optimum parameters for the design and fabrication of SPR sensors of high sensitivity, resolution, stability, and long decay-length evanescent fields. We present simulations and experimental SPR data for variety of sensors fabricated by using bimetal (Ag/Au) and multilayer waveguide-coupled Ag/Si3N4/Au structures. The simulations were carried out by using the transfer matrix method in MATLAB environment. Results are presented as functions of the thickness of the metal (Ag or Au) and the waveguide dielectric used in Ag/Si3N4/Au structures. Excellent agreement is observed between the simulations and experiments. For optimized thickness of the Si3N4 waveguide (150 nm), the sensor exhibits very high sensitivity to changes in the refractive index of analytes, Sn≈52°/R I U , extremely high resolution (F W H M ≤0.28° ) , and long penetration depth of evanescent fields (δ≥305 n m ) .

  4. Trimethylsilylcyclopentadienyl tris(dimethylamino)zirconium as a single-source metal precursor for the atomic layer deposition of Zr{sub x}Si{sub 1-x}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yoon Jang; Moon, Dae-Chul; Han, Jeong Hwan [Thin Film Materials Group, Korea Research Institute of Chemical Technology, 141 Gajeong-Ro, Yuseong-gu, Daejeon 305-600 (Korea, Republic of); Park, Mira; Park, Jung Woo [Thin Film Material Team, Hansol Chemical, 816 Wanju-gun, Jeonbuk 565-904 (Korea, Republic of); Chung, Taek-Mo; Lee, Young Kuk [Thin Film Materials Group, Korea Research Institute of Chemical Technology, 141 Gajeong-Ro, Yuseong-gu, Daejeon 305-600 (Korea, Republic of); An, Ki Seok, E-mail: ksan@krict.re.kr [Thin Film Materials Group, Korea Research Institute of Chemical Technology, 141 Gajeong-Ro, Yuseong-gu, Daejeon 305-600 (Korea, Republic of)

    2014-08-01

    Zr Silicate (Zr{sub x}Si{sub 1-x}O{sub 4}) films with a cation ratio of Zr:Si = 3:1 were deposited by atomic layer deposition (ALD) using trimethylsilylcyclopentadienyl tris(dimethylamino)zirconium (SCTDMAZ) and ozone as a single-source metal precursor and oxidant, respectively. The resultant films showed low residual impurity concentration as well as excellent conformality over complex structures, implying that the growth is controlled by a surface-limited reaction and hence proper ALD growth behavior. The Zr-silicate films exhibited amorphous characteristics as deposited and after post-deposition annealing (PDA) up to temperatures of 800 °C. After PDA the electrical properties of the amorphous Zr-silicate showed standard output values in the metal–insulator–semiconductor structure, with a low hysteresis of 0.04 V and moderate dielectric constant of ∼ 10. Accordingly, these experimental results suggest that SCTDMAZ is indeed a viable option as a single-source metal precursor for the ALD of Zr-silicate thin films. - Highlights: • Single source bimetal precursor for the atomic layer deposition (ALD) of Zr silicate • Characteristic ALD behavior was observed when using the precursor. • The resultant films show typical aspects found in Zr silicate films. • The precursor can easily be prepared by conventionally available chemicals.

  5. Study on antibacterial activity of chemically synthesized PANI-Ag-Au nanocomposite

    Science.gov (United States)

    Boomi, Pandi; Prabu, Halliah Gurumallesh; Manisankar, Paramasivam; Ravikumar, Sundaram

    2014-05-01

    Pristine polyaniline (PANI), PANI-Ag, PANI-Au and PANI-Ag-Au nanocomposites have been successfully synthesized by chemical oxidative polymerization method using aniline as monomer, ammonium persulphate as oxidant and metal (Ag, Au and Ag-Au) colloids. UV-Vis analysis exhibited surface Plasmon resonances of Ag, Au, Ag-Au nanoparticles. FT-IR spectra revealed the shift in peak position of N-H stretching. X-ray diffraction (XRD) results confirm the presence of Ag, Au and Au-Ag nanoparticles. HR-TEM images show nanosizes of Ag, Au, Ag-Au and the incorporation of such nanoparticles into the PANI matrix. Pristine PANI, PANI-Ag, PANI-Au and PANI-Ag-Au nanocomposites were tested for antibacterial activity by agar well diffusion method. PANI-Ag-Au nanocomposite exhibited higher antibacterial activity against both gram-positive [Streptococcus sp. (MTCC 890), Staphylococcus sp. (MTCC 96)] and gram-negative bacteria [Escherichia coli (MTCC 1671) and Klebsiella sp. (MTCC 7407)] when compared with PANI-Ag nanocomposite, PANI-Au nanocomposite and pristine PANI. The novelty of this study is the polymer-bimetal synthesis and its antibacterial potential.

  6. Study on antibacterial activity of chemically synthesized PANI-Ag-Au nanocomposite

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • New method of synthesizing PANI-Ag-Au nanocomposite. • Surface Plasmon resonance and formation of composite at nano level were analyzed. • HR-TEM study revealed uniform distribution of nanoparticles. • PANI-Ag-Au nanocomposite exhibited good antibacterial activity. - Abstract: Pristine polyaniline (PANI), PANI-Ag, PANI-Au and PANI-Ag-Au nanocomposites have been successfully synthesized by chemical oxidative polymerization method using aniline as monomer, ammonium persulphate as oxidant and metal (Ag, Au and Ag-Au) colloids. UV-Vis analysis exhibited surface Plasmon resonances of Ag, Au, Ag-Au nanoparticles. FT-IR spectra revealed the shift in peak position of N-H stretching. X-ray diffraction (XRD) results confirm the presence of Ag, Au and Au-Ag nanoparticles. HR-TEM images show nanosizes of Ag, Au, Ag-Au and the incorporation of such nanoparticles into the PANI matrix. Pristine PANI, PANI-Ag, PANI-Au and PANI-Ag-Au nanocomposites were tested for antibacterial activity by agar well diffusion method. PANI-Ag-Au nanocomposite exhibited higher antibacterial activity against both gram-positive [Streptococcus sp. (MTCC 890), Staphylococcus sp. (MTCC 96)] and gram-negative bacteria [Escherichia coli (MTCC 1671) and Klebsiella sp. (MTCC 7407)] when compared with PANI-Ag nanocomposite, PANI-Au nanocomposite and pristine PANI. The novelty of this study is the polymer-bimetal synthesis and its antibacterial potential

  7. High-performance PdRu bimetallic catalyst supported on mesoporous silica nanoparticles for phenol hydrogenation

    International Nuclear Information System (INIS)

    Graphical abstract: The addition of Ru could significantly improve the performance of the mesoporous silica nanoparticles supported PdRu/MSN catalyst, which showed over 5 times higher mass activity than the mono-Pd/MSN towards the liquid-phase hydrogenation of phenol. The improved dispersion and the electronic interaction contributed to the enhanced catalytic activity for the catalyst towards phenol hydrogenation. - Highlights: • PdRu bimetal catalyst supported on mesoporous silica nanoparticles was prepared. • The average sizeof PdRu alloy is smaller than that of mono-Pd. • The addition of Ru to Pd modulates the electronic properties between Pd and Ru. • PdRu/MSN catalyst shows superior activity on phenol hydrogenation than Pd/MSN. • PdRu/MSN catalyst shows good selectivity for cyclohexanol to some extent. - Abstract: A high-performance PdRu bimetallic catalyst supported on mesoporous silica nanoparticles (MSN), PdRu/MSN, was prepared by a facile impregnation–hydrogen reduction method. It was found that PdRu/MSN showed 5 times higher activity than that of Pd/MSN towards the liquid-phase hydrogenation of phenol. The catalysts were characterized comprehensively by multiple techniques, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and hydrogen temperature program reduction (TPR). It was revealed that adding Ru could effectively improve the Pd dispersion and promote the electronic interaction between the Pd and Ru, both of which contribute to enhancing the catalytic activity

  8. DESIGN AND CHARACTERIZATION OF THERMALLY ACTUATED BIMETALLIC MEMBRANES BY MICHELSON INTERFEROMETRY

    Directory of Open Access Journals (Sweden)

    JULIO ENRIQUE DUARTE

    2011-01-01

    Full Text Available En el presente trabajo se describen el diseño y la caracterización de membranas bimetálicas de Al-Si, con actuación térmica. El diseño se realizó empleando el método de los Elementos Finitos y se concentró en optimizar la relación de los espesores de las capas de aluminio y silicio. La defl exión de las membranas se determinó aplicando la técnica del Interferómetro de Michelson. En la etapa experimental se utilizaron membranas cuadradas de 5 mm de lado, con un espesor de 10 mm para el silicio y espesores de 4 y 1 mm para el aluminio. La caracterización entregó un desplazamiento máximo de 14 mm para la membrana con 4 mm de Al, lo cual es consistente con los resultados obtenidos numéricamente.

  9. OXIDATIVE ETHOXYCARBONYLATION OF ANILINE TO ETHYL PHENYLCARBAMATE CATALYZED BY SILICA-SUPPORTED POLY-γ-AMINOPROPYLSILOXANE-METAL COMPLEXES

    Institute of Scientific and Technical Information of China (English)

    GUAN Shiyou; HUANG Meiyu; JIANG Yingyan

    1993-01-01

    Several silica-supported poly-γ-aminopropylsiloxane-monometal and bimetal complexes (Si-NH2-M,M=Cu or Co;Si-NH2-Cu-M',M'=Co,Sn,Mn,Ni or Fe)have been prepared.Their catalytic properties for oxidative ethoxycarbonylation of aniline to ethyl phenylcarbamate have been investigated.The catalytic reaction was carried out under relatively mild conditions.The catalyst Si-NH2-Cu-Co had high activity and selectivity,and the turn-over number(molar of aniline converted/molar of metal in Si-NH2-Cu-Coadded)could amount to 450 under the conditions:150 ℃,4MPa(CO/O2=3) and 40 hours.The results of XPS and IR indicated that the coordination bonds were formed between nitrogen and metals in Si-NH2-Cu,Si-NH2-Co and Si-NH2-Cu-Co,and the coordination pattern was not single.In the oxidative ethoxycarbonylation of aniline to ethyl phenylcarbamate,the catalytic property of Si-NH2-Cu-Co bimetallic complex was better than Si- NH2-Cu or Si-NH2-Co monometallic complex.This indicated that there was synergistic action between different metals in the bimetallic complex.

  10. Composition Control of CuInSe2 Thin Films Using Cu/In Stacked Structure in Coulometric Controlled Electrodeposition Process.

    Science.gov (United States)

    Kwon, Yong Hun; Do, Hyun Woo; Kim, Hyoungsub; Cho, Hyung Koun

    2015-10-01

    Cu/In bi-metal stacked structures were prepared on Mo coated soda lime glass substrates using electrodeposition method. These metallic precursors were selenized at 550 °C for 60 min to synthesize the CuInSe2 (CIS) thin films in a thermal evaporator chamber with an Se overpressure atmosphere. The composition ratios of CIS thin films were systematically controlled using the coulometric method of the electrodeposition, where the accumulated coulomb of In layers was varied from 1062 to 6375 mC/cm2. As a result, the stoichiometric CIS film was obtained in the Cu/In coulomb ratio of 0.6. Highly crystallized CIS films were produced from the liquid Cu-Se phase in the Cu/In coulomb ratio of ≥0.6. In contrast, the crystallinity and grain size were degraded in the In-rich region. We found that the Cu/In composition ratio of CIS films was linearly proportional to the precursor thickness determined by the coulomb ratio. PMID:26726424

  11. Effect of vanadium doping on structural, magnetic and optical properties of ZnO nanoparticles

    International Nuclear Information System (INIS)

    V-doped ZnO nanoparticles were synthesized by heating metal acetates in organic solvent. All synthesized samples were annealed in air and reducing gas atmosphere at 600 deg. C for 8 h. The XRD patterns of both samples annealed in air and reducing atmosphere indicate that samples have polycrystalline wurtzite structure with increase in lattice constant with increase in V-doping. The particle sizes were calculated by using Scherrer's equation which lies in the range of 25-30 nm. The SEM images show that particles annealed in air and under reducing environment are spherical in nature. The EDX results reveal that samples contain V, Zn, and O contents only. The TPR results indicate that the system contains isolated VOx, ZnOx and bimetallic Zn: V (Ox) sites and indication of electronically excited bimetal sites. There is no signature of ferromagnetism in all samples annealed in air while room temperature ferromagnetism has been observed only under reducing atmosphere annealing. There is monotonically increase in saturation magnetization with V-doping concentration. UV-vis spectroscopy study shows that there is a linear increase in band gap energy with increase in V-doping, a direct evidence of change in magnetic properties due to V-doping and under reducing environment.

  12. Study on antibacterial activity of chemically synthesized PANI-Ag-Au nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Boomi, Pandi [Department of Industrial Chemistry, School of Chemical Sciences, Alagappa University, Karaikudi 630 003, Tamil Nadu (India); Prabu, Halliah Gurumallesh, E-mail: hgprabu2010@gmail.com [Department of Industrial Chemistry, School of Chemical Sciences, Alagappa University, Karaikudi 630 003, Tamil Nadu (India); Manisankar, Paramasivam [Department of Industrial Chemistry, School of Chemical Sciences, Alagappa University, Karaikudi 630 003, Tamil Nadu (India); Ravikumar, Sundaram [Department of Oceanography and Coastal Area Studies, School of Marine Sciences, Alagappa University, Thondi Campus 623 409, Tamil Nadu (India)

    2014-05-01

    Graphical abstract: - Highlights: • New method of synthesizing PANI-Ag-Au nanocomposite. • Surface Plasmon resonance and formation of composite at nano level were analyzed. • HR-TEM study revealed uniform distribution of nanoparticles. • PANI-Ag-Au nanocomposite exhibited good antibacterial activity. - Abstract: Pristine polyaniline (PANI), PANI-Ag, PANI-Au and PANI-Ag-Au nanocomposites have been successfully synthesized by chemical oxidative polymerization method using aniline as monomer, ammonium persulphate as oxidant and metal (Ag, Au and Ag-Au) colloids. UV-Vis analysis exhibited surface Plasmon resonances of Ag, Au, Ag-Au nanoparticles. FT-IR spectra revealed the shift in peak position of N-H stretching. X-ray diffraction (XRD) results confirm the presence of Ag, Au and Au-Ag nanoparticles. HR-TEM images show nanosizes of Ag, Au, Ag-Au and the incorporation of such nanoparticles into the PANI matrix. Pristine PANI, PANI-Ag, PANI-Au and PANI-Ag-Au nanocomposites were tested for antibacterial activity by agar well diffusion method. PANI-Ag-Au nanocomposite exhibited higher antibacterial activity against both gram-positive [Streptococcus sp. (MTCC 890), Staphylococcus sp. (MTCC 96)] and gram-negative bacteria [Escherichia coli (MTCC 1671) and Klebsiella sp. (MTCC 7407)] when compared with PANI-Ag nanocomposite, PANI-Au nanocomposite and pristine PANI. The novelty of this study is the polymer-bimetal synthesis and its antibacterial potential.

  13. Characterisation of silicon microstrip detectors for the ATLAS Phase-II Upgrade with a micro-focused X-ray beam

    CERN Document Server

    Poley, Luise; Bates, Richard; Bloch, Ingo; Diez, Sergio; Fernandez-Tejero, Javier; Fleta, Celeste; Gallop, Bruce; Greenall, Ashley; Gregor, Ingrid-Maria; Hara, Kazuhiko; Ikegami, Yoichi; Lacasta, Carlos; Lohwasser, Kristin; Maneuski, Dzmitry; Nagorski, Sebastian; Pape, Ian; Phillips, Peter W; Sperlich, Dennis; Sawhney, Kawal; Soldevila, Urmila; Ullan, Miguel; Unno, Yoshinobu; Warren, Matt

    2016-01-01

    The planned HL-LHC (High Luminosity LHC) in 2025 is being designed to maximise the physics potential through a sizable increase in the luminosity, totalling 1x10^35 cm^-2 s^-1 after 10 years of operation. A consequence of this increased luminosity is the expected radiation damage at 3000 fb^-1, requiring the tracking detectors to withstand hadron equivalences to over 1x10^16 1 MeV neutrons per cm^2. With the addition of increased readout rates, a complete re-design of the current ATLAS Inner Detector (ID) is being developed as the Inner Tracker (ITk). Two proposed detectors for the ATLAS strip tracker region of the ITk were characterized at the Diamond Light Source with a 3 micron FWHM 15 keV micro focused X-ray beam. The devices under test were a 320 micron thick silicon stereo (Barrel) ATLAS12 strip mini sensor wire bonded to a 130 nm CMOS binary readout chip (ABC130) and a 320 micron thick full size radial (Endcap) strip sensor - utilizing bi-metal readout layers - wire bonded to 250 nm CMOS binary readout...

  14. Influence of Ag-Au microstructure on the photoelectrocatalytic performance of TiO2 nanotube array photocatalysts.

    Science.gov (United States)

    Wang, Qingyao; Wang, Xiaotong; Zhang, Miao; Li, Guihua; Gao, Shanmin; Li, Mingyang; Zhang, Yiqing

    2016-02-01

    In this work, vertically-aligned TiO2 nanotube arrays (TiO2 NTs) were grown on Ti substrates via a facile electrochemical anodization method followed by calcinations. Then, Ag-Au alloy nanoparticles and Ag@Au core-shell nanoparticles were deposited on the obtained TiO2 NTs via UV reduction and displacement reaction, respectively. X-ray diffraction, scanning electron microscopy and transmission electron microscopy indicated that Ag-Au alloy nanoparticles and Ag@Au core-shell nanoparticles grew uniformly on the walls of TiO2 NTs. Investigation results from removal of methyl orange (MO) and Cr(IV) ions indicated that the as-prepared bimetal plasmonic photocatalysts exhibited excellent photoelectrocatalytic (PEC) activities. The influences of Ag-Au alloy and core-shell microstructures on PEC properties of TiO2 NTs were investigated and the TiO2 NTs/Ag@Au photocatalyst showed more outstanding PEC removal efficiency than that of TiO2 NTs/Ag-Au due to the regular core-shell microstructure and low recombination of photogenerated electrons and holes. PMID:26555961

  15. Molecular insights into the enzymatic diversity of flavin-trafficking protein (Ftp; formerly ApbE) in flavoprotein biogenesis in the bacterial periplasm.

    Science.gov (United States)

    Deka, Ranjit K; Brautigam, Chad A; Liu, Wei Z; Tomchick, Diana R; Norgard, Michael V

    2016-02-01

    We recently reported a flavin-trafficking protein (Ftp) in the syphilis spirochete Treponema pallidum (Ftp_Tp) as the first bacterial metal-dependent FAD pyrophosphatase that hydrolyzes FAD into AMP and FMN in the periplasm. Orthologs of Ftp_Tp in other bacteria (formerly ApbE) appear to lack this hydrolytic activity; rather, they flavinylate the redox subunit, NqrC, via their metal-dependent FMN transferase activity. However, nothing has been known about the nature or mechanism of metal-dependent Ftp catalysis in either Nqr- or Rnf-redox-containing bacteria. In the current study, we identified a bimetal center in the crystal structure of Escherichia coli Ftp (Ftp_Ec) and show via mutagenesis that a single amino acid substitution converts it from an FAD-binding protein to a Mg(2+) -dependent FAD pyrophosphatase (Ftp_Tp-like). Furthermore, in the presence of protein substrates, both types of Ftps are capable of flavinylating periplasmic redox-carrying proteins (e.g., RnfG_Ec) via the metal-dependent covalent attachment of FMN. A high-resolution structure of the Ftp-mediated flavinylated protein of Shewanella oneidensis NqrC identified an essential lysine in phosphoester-threonyl-FMN bond formation in the posttranslationally modified flavoproteins. Together, these discoveries broaden our understanding of the physiological capabilities of the bacterial periplasm, and they also clarify a possible mechanism by which flavoproteins are generated. PMID:26626129

  16. 1996 outstanding facts; Faits marquants 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This progress report of the Direction of Studies and Research (DER) of Electricite de France (EdF) reports on some outstanding studies carried out during the year 1996 and concerning: new applications of electric power (thermal comfort, heating floors, building diagnosis, energy management, customers communicating interfaces, services, air conditioning, off-peak tariffs, power demand mastery in the industry, infrared dryers for paper industry); production means (automatic systems for nuclear power plants operation, management of reactors shutdown schedules for refuelling operations, optimization of fuel loading patterns for PWRs, neutronic and thermohydraulic computer codes for steam pipes rupture accidents, thermo-hydraulic modeling of the confinement building during post-accidental situation, 3D numerical simulation of overpressures inside reactor valves and of vortex and two-phase flow inside auxiliary pipes, control of vibrating fatigue of pipe nozzles, qualification of the adjustable speed drives of the Gravelines` cooling pumps, 3D analysis of new steam turbine designs, identification of bi-metal welding surface defects, a simple method for the evaluation of in-service fatigue of components, the probabilistic dimensioning of safety coefficients, the modeling of thermo-hydro-mechanical coupling of geo-materials for radioactive wastes storage, the supply of isolated sites using renewable energies); environment protection (batteries for electric-powered vehicles, modeling of atmospheric reactive flows, chlorination of the Dampierre`s cooling circuits for pathogen amoebas elimination, in-situ treatment of PCBs isolated transformers); and development and exploitation of materials for power networks. (J.S.).

  17. Electrodeposition of Cu-Pd alloys onto electrophoretic deposited carbon nanotubes for nitrate electroreduction

    International Nuclear Information System (INIS)

    Copper-palladium (Cu-Pd) alloys have been electrodeposited onto carbon nanotubes, which were uniformly and stably deposited on Ti plates via electrophoretic deposition. Electrodes with a wide range of Cu/Pd atomic ratios were fabricated by potentiostatic coelectrodeposition of Cu and Pd onto Ti/CNTs. They were characterized by energy-dispersive X-ray analyzer, X-ray diffraction and tested for nitrate electroreduction. The electrode deposited in bath with 5 mM Cu2+ and 5 mM Pd2+ (Ti/CNTs/Cu5-Pd5) possessed outstanding stability as well as the highest electrocatalytic activity with the best nitrate conversion yield and proper N2 selectivity, indicating a synergistic effect of Cu and Pd. X-ray photoelectron spectroscopy and scanning electron microscopy analysis of Ti/CNTs/Cu5-Pd5 and Ti/Cu5-Pd5 revealed that CNTs played a remarkable role in the homogeneous formation of the bimetal, significantly improving the alloy's electrocatalytic activity and stability. The fabricated Ti/CNTs/Cu5-Pd5 was proved to be a promising electrode for nitrate electroreduction.

  18. Delito económico, causa política: falsificadores y contrabandistas en el imperio de los Austrias durante el siglo XVII

    Directory of Open Access Journals (Sweden)

    Elena María García Guerra

    2007-10-01

    Full Text Available Durante el siglo XVII en la Corona de Castilla el sistema monetario bimetálico sufrió serias tensiones como consecuencia de los continuos cambios de valor y ley experimentados por la moneda fraccionaria o de vellón decretados por las autoridades al margen de los vaivenes del mercado. Dichas variaciones, además de alterar los precios y fomentar fraudes y falsificaciones de las piezas circulantes, crearon un fuerte malestar y fueron el origen de numerosas alteraciones del orden público. Nuestra comunicación analizará la legislación real y cierta documentación procedente de la Sala de Alcades de Casa y Corte y de la Real Chancillería de Valladolid - máximos tribunales en la Corte y en los reinos castellanos -, con tres objetivos: en primer lugar, conocer cómo perseguían las autoridades a los monederos falsos y los problemas derivados de la superposición de jurisdicciones a la hora de juzgarlos; en segundo lugar, cuáles fueron las medidas adoptadas para atajar las actividades de quienes practicaban cambios entre especies monetarias sin respetar las tasas establecidas, las cuales tanto tenían que ver con la llegada de los galeones de Indias; y, en tercer lugar, ofrecer algunas ideas en torno al delito de contrabando, agudizado por el poderoso atractivo que tenían las monedas de oro y plata castellanas para los naturales de las diferentes naciones europeas - Holanda, Inglaterra, Francia - que dominaban el comercio con América.

  19. NASA Tech Briefs, June 2013

    Science.gov (United States)

    2013-01-01

    Topics include: Cloud Absorption Radiometer Autonomous Navigation System - CANS, Software Method for Computed Tomography Cylinder Data Unwrapping, Re-slicing, and Analysis, Discrete Data Qualification System and Method Comprising Noise Series Fault Detection, Simple Laser Communications Terminal for Downlink from Earth Orbit at Rates Exceeding 10 Gb/s, Application Program Interface for the Orion Aerodynamics Database, Hyperspectral Imager-Tracker, Web Application Software for Ground Operations Planning Database (GOPDb) Management, Software Defined Radio with Parallelized Software Architecture, Compact Radar Transceiver with Included Calibration, Software Defined Radio with Parallelized Software Architecture, Phase Change Material Thermal Power Generator, The Thermal Hogan - A Means of Surviving the Lunar Night, Micromachined Active Magnetic Regenerator for Low-Temperature Magnetic Coolers, Nano-Ceramic Coated Plastics, Preparation of a Bimetal Using Mechanical Alloying for Environmental or Industrial Use, Phase Change Material for Temperature Control of Imager or Sounder on GOES Type Satellites in GEO, Dual-Compartment Inflatable Suitlock, Modular Connector Keying Concept, Genesis Ultrapure Water Megasonic Wafer Spin Cleaner, Piezoelectrically Initiated Pyrotechnic Igniter, Folding Elastic Thermal Surface - FETS, Multi-Pass Quadrupole Mass Analyzer, Lunar Sulfur Capture System, Environmental Qualification of a Single-Crystal Silicon Mirror for Spaceflight Use, Planar Superconducting Millimeter-Wave/Terahertz Channelizing Filter, Qualification of UHF Antenna for Extreme Martian Thermal Environments, Ensemble Eclipse: A Process for Prefab Development Environment for the Ensemble Project, ISS Live!, Space Operations Learning Center (SOLC) iPhone/iPad Application, Software to Compare NPP HDF5 Data Files, Planetary Data Systems (PDS) Imaging Node Atlas II, Automatic Calibration of an Airborne Imaging System to an Inertial Navigation Unit, Translating MAPGEN to ASPEN for

  20. Preparation of Ag/Cu Janus nanowires: Electrodeposition in track-etched polymer templates

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, X.R. [Henan Key Laboratory of Ion Beam Bioengineering, Physical Engineering College, Zhenzhou University, Zhengzhou 450052 (China); Wang, C.M.; Fu, Q.B. [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Jiao, Z.; Wang, W.D.; Qin, G.Y. [Henan Key Laboratory of Ion Beam Bioengineering, Physical Engineering College, Zhenzhou University, Zhengzhou 450052 (China); Xue, J.M., E-mail: jmxue@pku.edu.cn [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China)

    2015-08-01

    Highlights: • In this paper, we introduce a simple method for preparation of Janus nanowires by electrodeposition. • Using ion-track-etched PC polymer templates and commercial PC track-etched membrane templates, Ag/Cu Janus nanowires fabricated by this method all have uniform size. No matter how the holes array in the template, regular or not, the nanowires prepared by this method have similar properties. • By controlling the etching time, the size of the nanowires could be controlled easily and special shape nanowires also can be prepared by this template. • The polymer template is very easy to dissolve thoroughly and has no damage to nanowires almost. It is suitable for the preparation of nanowires suspension. • This method also has better applicability for polymer templates and can be seen as a simple convenient method for the preparation of Ag/Cu Janus nanowires. - Abstract: Bimetal (Janus) nanowire has been widely used as a promising nanoscale motor. In this paper we present a highly controllable method to fabricate Ag/Cu Janus nanowires using track-etched polymer templates. Ag/Cu Janus nanowires with uniform size and stabilized structure have been successfully fabricated by electrodepositing Ag nanowires, and subsequently Cu nanowires in track-etched polymer templates. The pore size of nanopores prepared by this template is uniform and continuously controlled, so aperture of achieved nanowires are uniform and can be regulated. This polymer template can dissolve inorganic solvents that do not react with the nanowires, making it is easy to release the nanowires into solution. The nanopore shape in the track-etched templates is adjustable (e.g. conical), nanowires with more special shapes could be fabricated. Thus, these features make this simple and inexpensive method very suitable for the preparation of Janus nanowire.

  1. Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor

    International Nuclear Information System (INIS)

    In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran[reg]), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran[reg]) are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub

  2. Hydroxyl capped silver-gold alloy nanoparticles: characterization and their combination effect with different antibiotics against Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Katayon Bahrami

    2014-04-01

    Full Text Available   Objective(s: Metal nanoparticles (NPs offer a wide variety of potential applications in pharmaceutical sciences due to the unique advances in nanotechnology research. In this work, bimetal Ag-Au alloy NPs were prepared and their combinations with other antibiotics were tested against Staphylococcus aureus .   Materials and Methods: Firstly, Ag-Au alloy NPs with Au/Ag molar ratio of 1:1 was fabricated and was purified by agarose gel electrophoresis system. The morphology and size of the purified NPs were confirmed by transmission electron microscopy. Chemical composition and surface chemistry of these NPs were studied with atomic absorption spectophotometry and Fourier transforms infrared spectroscopy, respectively. The size of purified Ag-Au alloy NPs was less than 200 nm. Also the presence of organic compounds with a hydroxyl residue was detected on the surface of these purified NPs. In next step the effect of purified Ag-Au alloy NPs on the antibacterial activity of different antibiotics was evaluated at sub-inhibitory content (5 μg/disk using disk diffusion method against S. aureus. Ag NPs and Au NPs were also tested at same content (5 μg using mentioned method. Results: The most enhancing effect of Ag-Au alloy NPs was observed for penicillin G and piperacillin. No enhancing effects on the antibacterial activity of different antibiotics were observed at 5 μg/disk for the mono-metal nanoparticles (Ag NPs and Au NPs against S. aureus. Conclusion: These results signify that the Ag-Au alloy NPs potentiates the antimicrobial action of certain antibiotics suggesting a possible utilization of this nano material in combination therapy against resistant S. aureus.

  3. Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lapa, N. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal)]. E-mail: ncsn@fct.unl.pt; Barbosa, R. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal); Lopes, M.H. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Mendes, B. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal); Abelha, P. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Gulyurtlu, I. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Santos Oliveira, J. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal)

    2007-08-17

    In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran[reg]), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran[reg]) are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub

  4. Thermal gain of CHP steam generator plants and heat supply systems

    Science.gov (United States)

    Ziganshina, S. K.; Kudinov, A. A.

    2016-08-01

    Heating calculation of the surface condensate heat recovery unit (HRU) installed behind the BKZ-420-140 NGM boiler resulting in determination of HRU heat output according to fire gas value parameters at the heat recovery unit inlet and its outlet, heated water quantity, combustion efficiency per boiler as a result of installation of HRU, and steam condensate discharge from combustion products at its cooling below condensing point and HRU heat exchange area has been performed. Inspection results of Samara CHP BKZ-420-140 NGM power boilers and field tests of the surface condensate heat recovery unit (HRU) made on the bimetal calorifier base КСк-4-11 (KSk-4-11) installed behind station no. 2 Ulyanovsk CHP-3 DE-10-14 GM boiler were the basis of calculation. Integration of the surface condensation heat recovery unit behind a steam boiler rendered it possible to increase combustion efficiency and simultaneously decrease nitrogen oxide content in exit gases. Influence of the blowing air moisture content, the excess-air coefficient in exit gases, and exit gases temperature at the HRU outlet on steam condensate amount discharge from combustion products at its cooling below condensing point has been analyzed. The steam condensate from HRU gases is offered as heat system make-up water after degasification. The cost-effectiveness analysis of HRU installation behind the Samara CHP BKZ-420-140 NGM steam boiler with consideration of heat energy and chemically purified water economy has been performed. Calculation data for boilers with different heat output has been generalized.

  5. Levulinic acid hydrogenolysis on Al2O3-based Ni-Cu bimetallic catalysts

    Institute of Scientific and Technical Information of China (English)

    Iker Obregón; Eriz Corro; Urko Izquierdo; Jesus Requies; Pedro L. Arias

    2014-01-01

    Inexpensive γ-alumina-based nickel-copper bimetallic catalysts were studied for the hydrogenolysis of levulinic acid, a key platform molecule for biomass conversion to biofuels and other valued chemicals, into γ-valerolactone as a first step towards the production of 2-methyltetrahydrofurane. The activities of both monometallic and bimetallic catalysts were tested. Their textural and chemical characteristics were determined by nitrogen physisorption, elemental analysis, temperature-pro-grammed ammonia desorption, and temperature-programmed reduction. The monometallic nickel catalyst showed high activity but the highest by-product production and significant amounts of carbon deposited on the catalyst surface. The copper monometallic catalyst showed the lowest activity but the lowest carbon deposition. The incorporation of the two metals generated a bimetal-lic catalyst that displayed a similar activity to that of the Ni monometallic catalyst and significantly low by-product and carbon contents, indicating the occurrence of important synergetic effects. The influence of the preparation method was also examined by studying impregnated- and sol-gel-derived bimetallic catalysts. A strong dependency on the preparation procedure and calcina-tion temperature was observed. The highest activity per metal atom was achieved using the sol-gel-derived catalyst that was calcined at 450 °C. High reaction rates were achieved;the total levulinic acid conversion was obtained in less than 2 h of reaction time, yielding up to 96%γ-valerolactone, at operating temperature and pressure of 250 °C and 6.5 MPa hydrogen, respec-tively.

  6. Design of household calorimeter flowmeter with a temperature-controlled device%带有温度自控装置的户用热量表流量计的设计

    Institute of Scientific and Technical Information of China (English)

    王海燕

    2011-01-01

    设计了一种在超声波热量表中用的测量管道.由于超声波测量管体、传感器安装孔、传感器穿线管和安装座在焊接为一体时,难以保证各部件的相互尺寸、位置精度要求,所以设计提出将以上结构一次铸造成型,并在实现一体化的基础上加装双金属测温器.由于采用一次铸造成型,所以精度高,便于大批量生产;由于加了双金属片测温器,及由其控制伸缩改变热水流量的方形板,可自动调控室内温度,可广泛用于取暖管的控制.%Designed a calorimeter using the ultrasonic measurement of pipe.As the ultrasonic measuring tube ,the sensor mounting hole ,the sensor threading pipe and install the seat in welding as a whole ,it is difficult to ensure the various components of each size, position accuracy requirements ,so the design of the above structure ,a cast molding, and the integration of the based on the device to install pairs of metal temperature. As a result of a cast molding,so high precision,easy to mass production;due to increase of the bimetal temperature measurement devices,and flexible to change the water flow under the control of a square plate ,can automatically control the indoor temperature can be widely used for heating tube control.

  7. Removal of trichloroethylene DNAPL trapped in porous media using nanoscale zerovalent iron and bimetallic nanoparticles: Direct observation and quantification

    International Nuclear Information System (INIS)

    Highlights: ► TCE DNAPL removal inside pores using NZVI or bimetals in a 2-D system was visualized. ► Presence of nitrate and humic substances decrease the TCE DNAPL removal efficiency. ► Presence of ethanol increases the TCE DNAPL removal efficiency. ► Metal catalysts enhance the TCE DNAPL removal using NZVI in a short term reaction. ► Metal catalysts do not increase the DNAPL removal efficiency for a long term reaction. - Abstract: Direct trichloroethylene (TCE) dense non-aqueous phase liquid (DNAPL) removal inside pore areas using nanoscale zerovalent iron (NZVI) and bimetallic nanoparticles were first investigated in a water-saturated porous glass micromodel. Effects of nitrate, aqueous ethanol co-solvent, humic substance, and elapsed time on TCE DNAPL removal using NZVI were studied by direct visualization. The removal efficiency was then quantified by directly measuring the remaining TCE DNAPL blobs area using an image analyzer. As ethanol content of co-solvent increased, TCE DNAPL removal by NZVI was also increased implying sequential TCE DNAPL removal mechanisms: as dissolved TCE was degraded by NZVI, TCE dissolution from TCE blobs would be then facilitated and the TCE blob areas would be eventually reduced. The presence of nitrate and humic substance hindered the NZVI reactivity for the TCE DNAPL removal. In contrast, the TCE DNAPL removal efficiency was enhanced using bimetallic nanoparticles in a short-term reaction by generating atomic hydrogen for catalytic hydro-dechlorination. However, all TCE DNAPL removal efficiencies reached the same level after long-term reaction using both NZVI and bimetallic nanoparticles. Direct TCE DNAPL observation clearly implied that TCE blobs existed for long time even though all TCE blobs were fully exposed to NZVI and bimetallic nanoparticles.

  8. Preparation of Ag/Cu Janus nanowires: Electrodeposition in track-etched polymer templates

    International Nuclear Information System (INIS)

    Highlights: • In this paper, we introduce a simple method for preparation of Janus nanowires by electrodeposition. • Using ion-track-etched PC polymer templates and commercial PC track-etched membrane templates, Ag/Cu Janus nanowires fabricated by this method all have uniform size. No matter how the holes array in the template, regular or not, the nanowires prepared by this method have similar properties. • By controlling the etching time, the size of the nanowires could be controlled easily and special shape nanowires also can be prepared by this template. • The polymer template is very easy to dissolve thoroughly and has no damage to nanowires almost. It is suitable for the preparation of nanowires suspension. • This method also has better applicability for polymer templates and can be seen as a simple convenient method for the preparation of Ag/Cu Janus nanowires. - Abstract: Bimetal (Janus) nanowire has been widely used as a promising nanoscale motor. In this paper we present a highly controllable method to fabricate Ag/Cu Janus nanowires using track-etched polymer templates. Ag/Cu Janus nanowires with uniform size and stabilized structure have been successfully fabricated by electrodepositing Ag nanowires, and subsequently Cu nanowires in track-etched polymer templates. The pore size of nanopores prepared by this template is uniform and continuously controlled, so aperture of achieved nanowires are uniform and can be regulated. This polymer template can dissolve inorganic solvents that do not react with the nanowires, making it is easy to release the nanowires into solution. The nanopore shape in the track-etched templates is adjustable (e.g. conical), nanowires with more special shapes could be fabricated. Thus, these features make this simple and inexpensive method very suitable for the preparation of Janus nanowire

  9. Fabrication of an organic light-emitting diode inside a liquid crystal display

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jiun-Haw; Chang, Wei-Fu; Wu, Cheng-Che [Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan, ROC (China); Lin, Chi-Feng [Department of Electro-Optical Engineering, National United University, Miaoli 36003, Taiwan, ROC (China); Lee, Jiunn-Yih [Department of Materials Science and Engineering, National Taiwan University Science and Technology, Taipei 10617, Taiwan, ROC (China); Chiu, Tien-Lung, E-mail: tlchiu@saturn.yzu.edu.tw [Department of Photonics Engineering, Yuan Ze University, Chungli, Taoyuan 32003, Taiwan, ROC (China)

    2013-10-31

    The fabrication of a hybrid device architecture fully integrating a transparent organic light-emitting diode (OLED) and a liquid crystal display (LCD) within two glass substrates is reported in this study. The transparent OLED was fabricated on the inner surface of the glass substrate. Twisted nematic liquid crystal (LC) materials were used to fill the space between the two glass substrates. The OLED was driven by an indium-tin oxide (ITO) anode on the glass substrate and a thin bi-metal (Al/Ag) cathode, which also served as the electrode of the LCD. The other electrode for the LCD-mode operation was the ITO on the other glass substrate. A commercially available ultraviolet (UV)-curable resin was spun onto the thin Al/Ag as the passivation layer to protect the OLED from attacks by the following polyimide layer (serving as the alignment layer of the LCD), rubbing process and LC materials. In this device structure, the electrical characteristic of the OLED-mode operation was almost the same as that of the control device. Current efficiency (in terms of cd/A) of the hybrid device from top-emission (towards the LCD) decreased by 26.5% due to optical interference effect, whereas efficiency from bottom-emission remained the same. The driving voltage of the LCD-mode operation increased by 1.6 V due to the insertion of the passivation layer between the two electrodes. The contrast ratio decreased from 150 to 25 due to the reflection of the thin Al/Ag layer. Compared with that of the control device, the storage lifetime of the OLED increased as a result of filling the encapsulated cavity with LC materials, which helped repel ambient water and oxygen. - Highlights: • Organic light emitting device (OLED) was fabricated inside liquid crystal device (LCD). • LCD protected OLED from the attack of ambient oxygen and moisture. • OLED functions were not affected by LCD process with suitable treatment.

  10. Ethylbenzene dehydrogenation over Mg3Fe0.5−xCoxAl0.5 catalysts derived from hydrotalcites: Comparison with Mg3Fe0.5−yNiyAl0.5 catalysts

    KAUST Repository

    Atanda, Luqman A.

    2011-04-01

    A series of Mg3Fe0.5-xCoxAl0.5 (x = 0-0.5) catalysts were prepared from hydrotalcite precursors and their activities in the dehydrogenation of ethylbenzene were compared with those of a series of Mg3Fe0.5-yNiyAl0.5 (y = 0-0.5) catalysts also derived from hydrotalcite. The hydrotalcites prepared by co-precipitation were calcined at 550 °C to the mixed oxides with a high surface area of 150-240m2gcat-1; they were composed of Mg(Fe,Me,Al)O periclase and Mg(Me)(Fe,Al)2O4 spinel (Me = Co or Ni). Bimetallic Fe3+-Co2+ system showed a synergy, i.e., an increase in the activity, whereas Fe3+-Ni2+ bimetallic system showed no synergy. The high styrene yield was obtained on Mg 3Fe0.1Co0.4Al0.5; however, a large substitution of Fe3+ with Co2+ caused a decrease in styrene selectivity along with coking on the catalysts, due to an isolation of CoOx on the catalyst surface. The highest yield as well as the highest selectivity for styrene production was obtained at x = 0.25 at time on stream of 30 min. The coprecipitation at pH = 10.0 and the composition of Mg3Fe0.25Co0.25Al0.5 were the best for preparing the active catalyst. This is partly due to the formation of a good hydrotalcite structure. On this catalyst, the active Fe3+ species was reduced at a low temperature by the Fe3+-Co2+ bimetal formation, leading to a high activity. Simultaneously, the amount of reducible Fe3+ was the smallest, resulting in a high stability of the active Fe3+ species. It is likely that the dehydrogenation was catalyzed by the reduction-oxidation between Fe3+ and Fe2+ and that Co2+ assisted the reduction-oxidation by forming Fe 3+-Co2+ (1/1) bimetallic active species. © 2011 Elsevier B.V. All rights reserved.

  11. ANOMALOUS ELECTRODEPOSITION OF Fe-Ni ALLOY COATING FROM SIMPLE AND COMPLEX BATHS AND ITS MAGNETIC PROPERTY

    Directory of Open Access Journals (Sweden)

    M A Islam

    2010-03-01

    Full Text Available Electrodeposition of Fe-Ni thin films has been carried on copper substrate under various electrodeposition conditions from two simple and six complex baths. Sulfate baths composing of NiSO4. 7H2O, FeSO4.7H2O, H3BO3 and Na2SO4KEYWORDS: Anomalous Electrodeposition, Fe-Ni Coating, Complexing agent, Current Density, Magnetic Property. 1. INTRODUCTION Alloy electrodeposition technologies can extend tremendously the potential of electrochemical deposition processes to provide coatings that require unique mechanical, chemical and physical properties [1]. There has been a great research interest in the development and characterization of iron-nickel (Fe-Ni thin films due to their operational capacity, economic interest, magnetic and other properties [2]. Due to their unique low coefficient of thermal expansion (CTE and soft magnetic properties, Fe-Ni alloys have been used in industrial applications for over 100 years [3]. Typical examples of applications that are based on the low CTE of Fe-Ni alloys include: thermostatic bimetals, glass sealing, integrated circuit packaging, cathode ray tube, shadow masks, membranes for liquid natural gas tankers; applications based on the soft magnetic properties include: read-write heads for magnetic storage, magnetic actuators, magnetic shielding, high performance transformer cores. comprise the simple baths whereas complex baths were prepared by adding ascorbic acid, saccharin and citric acid in simple baths. The effect of bath composition, pH and applied current density on coating appearance, composition, morphology and magnetic property were studied. Wet chemical analysis technique was used to analyze the coating composition whereas SEM and VSM were used to study the deposit morphology and magnetic property respectively. Addition of complexing agents in plating baths suppressed the anomalous nature of Fe-Ni alloy electrodeposition. Coatings obtained from simple baths were characterized by coarse grained non

  12. Uma análise crítica da literatura sobre a oferta e a circulação de moeda metálica no Brasil nos séculos XVI e XVII

    Directory of Open Access Journals (Sweden)

    Fernando Carlos G. de Cerqueira Lima

    2005-03-01

    Full Text Available Este artigo examina os principais fatores determinantes da oferta e da circulação de moeda metálica no Brasil nos séculos XVI e XVII. O objetivo é contribuir para o debate, até hoje pouco explorado, sobre a escassez de moeda no Brasil colonial. O trabalho é dividido em seis seções, além da introdução e considerações finais. A primeira apresenta as principais características do sistema bimetálico então vigente em Portugal e de sua política de desvalorização da unidade de conta. A análise da oferta de moeda no Brasil é desenvolvida nas quatro seções seguintes, destacando o início do processo de monetização, os fluxos de entrada e saída de metais, os impactos da política de cunhagem metropolitana e os episódios de remarcação e cunhagem de moeda no Brasil. Os determinantes do entesouramento são discutidos a seguir. Uma última seção resume os argumentos apresentados ao longo do trabalho.This paper examines the main factors that determined the supply and circulation of metallic coins in Brazil in the sixteenth and seventeenth centuries. The objective is to contribute to the debate, often neglected, on the scarcity of money in colonial Brazil. The paper is divided into six parts, on top of the introduction and the concluding remarks. The first presents the main features of the then prevalent Portuguese monetary system, as well as its policy of debasement. The next four parts deal with the supply of metallic currency in Brazil analysing respectively the early stages of the process of monetization, the inflows and outflows of precious metals, the impacts of the policy of coinage adopted by the Portuguese Crown, and some episodes of marking and minting of coins in Brazil. This is followed by an analysis of hoarding. It concludes with a summary of the main arguments developed along the paper.

  13. Equilibrios químicos en bioadsorción

    Directory of Open Access Journals (Sweden)

    Romera, E.

    2007-02-01

    Full Text Available An experimental study of biosorption was carried out using six different kinds of algae and five different heavy metals (cadmium, copper, nickel, lead and zinc. Experimental data fitted very well to Langmuir’s model and this allowed to predict the behaviour of the biomass under specific working conditions. Using the equations of the model under different initial assumptions, a series of mathematical calculations were done for monometallic, bimetallic and trimetallic systems. The most complicated calculation is that in which, knowing the initial metal concentration (C0, it is necessary to calculate the conditions reached at the equilibrium, this is, qe and Ce. This assumption is of great interest from the point of view of the actual applicability of the process. However, in this case, it is necessary to solve very complex mathematical equations which, for multimetallic systems, are of degree n+1, where n is the number of ions present in solution.The excellent correlation between experimental and theoretical data demonstrates that the  biosorption process can be modelling.

    Se ha realizado un estudio experimental de bioadsorción utilizando seis tipos diferentes de algas y cinco metales pesados (cadmio, cobre, níquel, plomo y zinc. El buen ajuste de los datos experimentales al modelo de Langmuir ha permitido poder predecir el comportamiento de la biomasa en unas condiciones determinadas de trabajo. Todo ello, en base a una serie de cálculos matemáticos, utilizando las propias ecuaciones del modelo y bajo distintos supuestos iniciales de cálculo, tanto en sistemas monometálicos como en sistemas bimetálicos y trimetálicos. El supuesto de cálculo más complicado es el que, conociendo la concentración metálica inicial (C0 se deseen calcular las condiciones que se alcanzarían en el equilibrio, es decir, qe y Ce. Este, sería un supuesto de máximo interés de cara a

  14. Environmental application of millimeter-scale sponge iron (s-Fe{sup 0}) particles (II): The effect of surface copper

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Yongming, E-mail: juyongming@scies.org [South China Institute of Environmental Sciences, The Ministry of Environmental Protection of the PRC, Guangzhou 510655 (China); Liu, Xiaowen, E-mail: liuxiaowen@scies.org [South China Institute of Environmental Sciences, The Ministry of Environmental Protection of the PRC, Guangzhou 510655 (China); Liu, Runlong; Li, Guohua; Wang, Xiaoyan; Yang, Yanyan; Wei, Dongyang; Fang, Jiande [South China Institute of Environmental Sciences, The Ministry of Environmental Protection of the PRC, Guangzhou 510655 (China); Dionysiou, Dionysios D., E-mail: dionysios.d.dionysiou@uc.edu [Environmental Engineering and Science Program, Department of Biomedical, Chemical and Environmental Engineering (DBCEE), University of Cincinnati, Cincinnati, Ohio 45221-0012 (United States)

    2015-04-28

    Highlights: • Facile reduction reaction achieves decoration of Cu{sup 0} onto the surface of s-Fe{sup 0}. • The removal efficiency of RhB over Cu{sup 0}–s-Fe{sup 0} was similar to that of Cu{sup 0}–nZVI. • Cu{sup 0}–s-Fe{sup 0} can operate under mild condition with lower cost compared to nZVI. • The reductive mechanism over Cu{sup 0}–s-Fe{sup 0} under US condition is also elucidated. - Abstract: To enhance the catalytic reactivity of millimeter-scale particles of sponge iron (s-Fe{sup 0}), Cu{sup 2+} ions were deposited on the surface of s-Fe{sup 0} using a simple direct reduction reaction, and the catalytic properties of the bimetallic system was tested for removal of rhodamine B (RhB) from an aqueous solution. The influence of Cu{sup 0} loading, catalyst dosage, particle size, initial RhB concentration, and initial pH were investigated, and the recyclability of the catalyst was also assessed. The results demonstrate that the 3 ∼ 5 millimeter s-Fe{sup 0} particles (s-Fe{sup 0}(3 ∼ 5 mm)) with 5 wt% Cu loading gave the best results. The removal of RhB followed two-step, pseudo-first-order reaction kinetics. Cu{sup 0}–s-Fe{sup 0} showed excellent stability after five reuse cycles. Cu{sup 0}–s-Fe{sup 0} possesses great advantages compared to nanoscale zero-valent iron, iron power, and iron flakes as well as its bimetals. The surface Cu{sup 0} apparently catalyzes the production of reactive hydrogen atoms for indirect reaction and generates Fe-Cu galvanic cells that enhance electron transfer for direct reaction. This bimetallic catalyst shows great potential for the pre-treatment of recalcitrant wastewaters. Additionally, some oxides containing iron element are selected to simulate the adsorption process. The results prove that the adsorption process of FeOOH, Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4} played minor role for the removal of RhB.

  15. Ion beam processing of surfaces and interfaces. Modeling and atomistic simulations

    International Nuclear Information System (INIS)

    , sputtering is not the dominant driving force responsible for the ripple formation. Processes like bulk and surface defect kinetics dominate the surface morphology evolution. Only at grazing incidence the sputtering has been found to be a direct cause of the ripple formation. Bradley and Harper theory fails in explaining the ripple dynamics because it is based on the second-order-effect 'sputtering'. However, taking into account the new mechanisms, a 'Bradley-Harper equation' with redefined parameters can be derived, which describes pattern formation satisfactorily. (ii) Kinetics of (bulk) defects has been revealed as the dominating driving force of pattern formation. Constantly created defects within the collision cascade, are responsible for local surface topography fluctuation and cause surface mass currents. The mass currents smooth the surface at normal and close to normal ion incidence angles, while ripples appear first at θ ≥ 40 . The evolution of bimetallic interfaces under ion irradiation is another application of TRIDER described in this thesis. The collisional mixing is in competition with diffusion and phase separation. The irradiation with He+ ions is studied for two extreme cases of bimetals: (i) Irradiation of interfaces formed by immiscible elements, here Al and Pb. Ballistic interface mixing is accompanied by phase separation. Al and Pb nanoclusters show a self-ordering (banding) parallel to the interface. (ii) Irradiation of interfaces by intermetallics forming species, here Pt and Co. Well-ordered layers of phases of intermetallics appear in the sequence Pt/Pt3Co/PtCo/PtCo3/Co. The TRIDER program package has been proven to be an appropriate technique providing a complete picture of mixing mechanisms.

  16. Ion beam processing of surfaces and interfaces. Modeling and atomistic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Liedke, Bartosz

    2011-03-24

    general, sputtering is not the dominant driving force responsible for the ripple formation. Processes like bulk and surface defect kinetics dominate the surface morphology evolution. Only at grazing incidence the sputtering has been found to be a direct cause of the ripple formation. Bradley and Harper theory fails in explaining the ripple dynamics because it is based on the second-order-effect 'sputtering'. However, taking into account the new mechanisms, a 'Bradley-Harper equation' with redefined parameters can be derived, which describes pattern formation satisfactorily. (ii) Kinetics of (bulk) defects has been revealed as the dominating driving force of pattern formation. Constantly created defects within the collision cascade, are responsible for local surface topography fluctuation and cause surface mass currents. The mass currents smooth the surface at normal and close to normal ion incidence angles, while ripples appear first at θ ≥ 40 . The evolution of bimetallic interfaces under ion irradiation is another application of TRIDER described in this thesis. The collisional mixing is in competition with diffusion and phase separation. The irradiation with He{sup +} ions is studied for two extreme cases of bimetals: (i) Irradiation of interfaces formed by immiscible elements, here Al and Pb. Ballistic interface mixing is accompanied by phase separation. Al and Pb nanoclusters show a self-ordering (banding) parallel to the interface. (ii) Irradiation of interfaces by intermetallics forming species, here Pt and Co. Well-ordered layers of phases of intermetallics appear in the sequence Pt/Pt{sub 3}Co/PtCo/PtCo{sub 3}/Co. The TRIDER program package has been proven to be an appropriate technique providing a complete picture of mixing mechanisms.

  17. P-DEMO for demonstration of fast spectrum transmutator PEACER

    International Nuclear Information System (INIS)

    generator modules are equipped at the above downcomer where the cooled coolant flows downward to the core. Heated LBE storage tank and cover gas control system (CGCS) are established on the upward reactor enclosure and transporter system for refueling also is in this region. The CGCS controls the dissolved oxygen level in LBE by flowing hydrogen and oxygen and traps radio-toxic polonium vapors. For the all potential accidents, the reactor vessel air cooling system (RVACS) is designed to remove decay heat by natural circulation of air. The primary shutdown control assemblies are established above the core held by magnetic drive mechanisms during normal operation. They are dropped with the loss of magnetic power into the core by gravity upon a demand. In the above core, the secondary shutdown assemblies are located with different holding mechanism, self-actuated bi-metal latches, and are dropped into the core in the case of accidents accompanying coolant temperature rises. P-DEMO operates at the low temperature range of 300 ∼ 450 deg. C in order to assure no corrosion problem for structural materials with LBE coolant throughout the 60 years of lifetime. Considering large density and inertial mass of LBE coolant, a three dimensional seismic isolation system is employed for both reactor and the preprocess units to assure their structural robustness

  18. Estimativa da radiação solar global diária em função do potencial de energia solar na superfície do solo Estimation of daily global solar radiation as a function of the solar energy potential at soil surface

    Directory of Open Access Journals (Sweden)

    André Belmont Pereira

    2002-06-01

    Full Text Available A radiação solar recebida na superfície do solo, além de sua relevância a diversas atividades humanas diárias, desempenha um papel importante no crescimento e desenvolvimento de plantas. Este trabalho teve por objetivo desenvolver e aferir um modelo de estimativa da densidade de fluxo de radiação solar global, em função do potencial de energia solar à superfície, no município de Ponta Grossa, PR, Brasil (latitude 25º13' S, longitude 50º03' W, altitude 880 m. Os valores estimados do potencial de energia solar obtidos em função de apenas uma medida realizada na passagem meridiana do sol foram confrontados com os valores medidos por um actinógrafo de placa bimetálica de Robitzsch para aqueles dias que apresentaram razão de insolação superior a 0,85. Este conjunto de dados foi submetido a uma análise de regressão linear simples, obtendo-se bom ajuste entre valores observados e calculados. Foi utilizado o método baseado no potencial de energia solar à superfície para estimativa dos coeficientes a e b da equação de Angström para a localidade em questão. A metodologia foi eficiente para quantificar a densidade de fluxo de radiação solar global, com rapidez e simplicidade, bem como revelaram que o critério de estimativa do potencial de energia solar gerou valores equivalentes aqueles obtidos pela metodologia clássica de Angström. O conhecimento do potencial de energia solar disponível e da densidade de fluxo de radiação global é de suma importância na estimativa da demanda máxima de evaporação, do consumo hídrico de culturas irrigadas e para o dimensionamento de artifícios de engenharia solar, tais como secadores, aquecedores, fogões solares, refrigeradores etc.The solar radiation received at the surface of the earth, apart from its relevance to several daily human activities, plays an important role in the growth and development of plants. The aim of the current work was to develop and gauge an estimation