WorldWideScience

Sample records for bimetals

  1. Bimetal switches in an AND logic gate

    Science.gov (United States)

    Lubrica, Joel V.; Lubrica, Quantum Yuri B.

    2016-09-01

    In this frontline, we use bimetal switches to provide inputs in an electrical AND logic gate. These switches can be obtained from the pre-heat starters of fluorescent lamps, by safely removing the glass enclosure. They may be activated by small open flames. This frontline has a historical aspect because fluorescent lamps, together with pre-heat starters, are now being replaced by compact fluorescent, halogen, and LED lamps.

  2. 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.

  3. Photomagnetism in cyano-bridged bimetal assemblies.

    Science.gov (United States)

    Ohkoshi, Shin-ichi; Tokoro, Hiroko

    2012-10-16

    The study of photoinduced phase-transition materials has implications for the fields of inorganic chemistry, solid-state chemistry, and materials science. Cyano-bridged bimetal assemblies are promising photomagnetic materials. Because cyano-bridged bimetal assemblies possess various absorption bands in the visible light region, their electronic and spin states can be controlled by visible light irradiation. Moreover, the selection of magnetic metal ions and organic ligands provide a way of controlling spin-spin interactions through a cyano bridge. In this Account, we describe cyano-bridged bimetal assemblies developed in our laboratory. Cu(II)(2)[Mo(IV)(CN)(8)]·8H(2)O (CuMo), Rb(I)Mn(II)[Fe(III)(CN)(6)] (RbMnFe), and Co(II)(3)[W(V)(CN)(8)](2)·(pyrimidine)(4)·6H(2)O (CoW) induce photomagnetism via photoinduced metal-to-metal charge transfers (MM'CT), while Fe(II)(2)[Nb(IV)(CN)(8)]·(4-pyridinealdoxime)(8)·2H(2)O (FeNb) exhibits a photoinduced magnetization via a photoinduced spin crossover. Irradiation with 473 nm light causes the CuMo system to exhibit a spontaneous magnetization with a Curie temperature (T(C)) of 25 K, but irradiation with 532, 785, and 840 nm light reduces the magnetization. In this reversible photomagnetic process, excitation of the MM'CT from Mo(IV) to Cu(II) produces a ferromagnetic mixed-valence isomer of Cu(I)Cu(II)[Mo(V)(CN)(8)]·8H(2)O (CuMo'). CuMo' returns to CuMo upon irradiation in the reverse-M'MCT band. RbMnFe shows a charge transfer (CT)-induced phase transition from the Mn(II)-Fe(III) phase to the Mn(III)-Fe(II) phase. Irradiation with 532 nm light converts the Mn(III)-Fe(II) phase into the Mn(II)-Fe(III) phase, and we observe photodemagnetization. In contrast, irradiation of the Mn(II)-Fe(III) phase with 410 nm light causes the reverse phase transition. A CT-induced Jahn-Teller distortion is responsible for this visible light-induced reversible photomagnetic effect. In the CoW system, a CT-induced spin transition causes the

  4. 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 ...

  5. 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.

  6. Study on liquid-liquid bimetal composite casting hammers

    Institute of Scientific and Technical Information of China (English)

    Rong Shoufan; Zhou Haitao; ZhuYongchang; Wang Junfa; Yao Jia; Li Chunhong

    2014-01-01

    Crusher hammers for the mineral processing industry must meet the demands of both high wear resistance at the hammer head and high impact toughness at the hammer handle. The crusher hammers made of Hadfield steel have typical y low service life of less than 40 hours. To solve the problem, a kind of bimetal crusher hammers made of high chromium cast iron (HCCI) and low al oy steel (LAS) has been successful y developed by using liquid-liquid composite casting. The microstructure and composite interface bonding was analyzed using optical microscope, SEM, EDX and XRD. Micrographs indicate that the composite interface is metal urgical y bonded with a zigzag shape across the boundary and without unbound region or void. After heat treatment, the composite hammers have shown excellent properties. The hardness of HCCI is at least 63 HRC and its αk is greater than 3.5 J•cm-2; the hardness of LAS is greater than 35 HRC and its αk is no less than 80 J•cm-2. Diffusion of elements takes place at the interface and forms a transition region. The micro hardness increases from LAS to the interface and then to HCCI. Wear comparison was made separately between the bimetal composite hammer and a Hadfield steel hammer in two quarries of Jilin province and Liaoning province. The results showed that the liquid-liquid bimetal composite hammers did not have the fal ing off of hammer head or impact fracture phenomenon, and their service life was 3.75 times as long as that of the Hadfield steel hammers.

  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. 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

  9. 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

  10. Dehalogenation of Aryl Halides Catalyzed by Montmorillonite Immobilized Bimetal Catalyst in Aqueous System

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A novel bisupported bimetal catalyst PVP-PdCl2-FeSO4/Al-Mont-PEG600 was prepared by immobilization of PVP (poly (N-vinyl-2-pyrrolidone)) supported bimetallic catalyst using alumina pillared inartificial montmorillonite as the carrier. This catalyst has good dehalogenation activity and selectivity to aryl halides-o-chlorotoluene in aqueous system in the presence of phase transfer catalyst (PEG) and sodium formate as hydrogen source. The catalyst also shows good reusability.

  11. Copper/zinc bimetal nanoparticles-dispersed carbon nanofibers: A novel potential antibiotic material.

    Science.gov (United States)

    Ashfaq, Mohammad; Verma, Nishith; Khan, Suphiya

    2016-02-01

    Copper (Cu) and zinc (Zn) nanoparticles (NPs) were asymmetrically distributed in carbon nanofibers (CNFs) grown on an activated carbon fiber (ACF) substrate by chemical vapor deposition (CVD). The CVD conditions were chosen such that the Cu NPs moved along with the CNFs during tip-growth, while the Zn NPs remained adhered at the ACF. The bimetal-ACF/CNF composite material was characterized by the metal NP release profiles, in-vitro hemolytic and antibacterial activities, and bacterial cellular disruption and adhesion assay. The synergetic effects of the bimetal NPs distributed in the ACFs/CNFs resulted from the relatively slower release of the Cu NPs located at the tip of the CNFs and faster release of the Zn NPs dispersed in the ACF. The Cu/Zn-grown ACFs/CNFs inhibited the growth of the Gram negative Escherichia coli, Gram positive Staphylococcus aureus, and Methicillin resistance Staphylococcus aureus bacterial strains, with superior efficiency (instant and prolonged inhibition) than the Cu or Zn single metal-grown ACFs/CNFs. The prepared bimetal-carbon composite material in this study has potential to be used in different biomedical applications such as wound healing and antibiotic wound dressing.

  12. 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.

  13. Synthesis and characterization of Pb-Bi bimetal nanoparticles by solution dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Yanbao [Laboratory of Special Functional Materials, Henan University, Kaifeng 475002 (China); Liu Jin [Laboratory of Special Functional Materials, Henan University, Kaifeng 475002 (China); Cao Liuqin [Laboratory of Special Functional Materials, Henan University, Kaifeng 475002 (China); Wu Zhishen [Laboratory of Special Functional Materials, Henan University, Kaifeng 475002 (China); Zhang Zhijun [Laboratory of Special Functional Materials, Henan University, Kaifeng 475002 (China)]. E-mail: zhaoyb902@henu.edu.cn; Dang Hongxin [Laboratory of Special Functional Materials, Henan University, Kaifeng 475002 (China)

    2006-09-10

    In this paper, we report a new solution synthetic route to prepare Pb-Bi bimetal nanoparticles from bulk ingot that is different from conventional solution methods. The Pb-Bi nanoparticles were prepared by dispersing directly melt Pb-Bi ingot in a suitable solvent and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and other techniques. Transmission electron microscopy shows that the Pb-Bi nanoparticles appear a spherical shape with an average diameter of 50 nm. X-ray diffraction studies show that the Pb-Bi nanoparticles contain crystalline Pb{sub 7}Bi{sub 3}, Bi and a little amount of PbO. Tribological results show that Pb-Bi nanoparticles as a lubricating additive show good antiwear properties. In addition, the formation mechanism of the Pb-Bi nanoparticles was also discussed.

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

    Directory of Open Access Journals (Sweden)

    Abdollah Hajivandi

    2016-06-01

    Full Text Available 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 m2/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.

  15. 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

    2016-01-01

    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 m2/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

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. Development of bimetal oxide doped multifunctional polymer nanocomposite for water treatment

    Science.gov (United States)

    Saxena, Swati; Saxena, Umesh

    2016-08-01

    Bimetal oxide doped polymer nanocomposite was developed using Alumina and Iron (III) Oxide as nanoparticles with Nylon 6, 6 and Poly (sodium-4-styrenesulphonate) as polymer matrix for removal of pollutants from water. The blend sample of polymers was prepared by well established solution blending technique and their nanocomposite samples were prepared through dispersion technique during the solution casting of blend sample. The fabricated composites were characterized adopting FTIR, XRD, FESEM and EDX techniques. XRD and FESEM were used for morphological characterization of nano phase, while FTIR and EDX analysis were adopted for characterization of chemical moieties in composites. In the study of pollutant removal capacities of prepared composites, 6 % nanocomposite provided the best results. It exhibited the maximum removal of all parameters. The removal of total alkalinity was 66.67 %, total hardness 42.85 %, calcium 66.67 %, magnesium 25 %, chloride 58.66 %, nitrate 34.78 %, fluoride 63.85 %, TDS 41.27 % and EC was up to the level of 41.37 % by this composite. The study is a step towards developing multifunctional, cost-effective polymer nanocomposites for water remediation applications.

  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. 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.

  4. 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

  5. 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.

  6. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Asemabadi, M. [School of Mechanical Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran 16844 (Iran, Islamic Republic of); Sedighi, M., E-mail: sedighi@iust.ac.ir [School of Mechanical Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran 16844 (Iran, Islamic Republic of); Honarpisheh, M. [School of Mechanical Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran 16844 (Iran, Islamic Republic of)

    2012-12-15

    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.

  8. Bimetal cup hydroforming of Al/St and Cu/St composites: Adaptive finite element analysis and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Hashemi, Abbas; Gollo, Mohammad Hoseinpour [Shahid Rajaee Teacher Training University, Tehran (Iran, Islamic Republic of); Seyedkashi, S. M. [University of Birjand, Birjand (Iran, Islamic Republic of)

    2016-05-15

    An adaptive Finite element analysis (FEA) was proposed in this paper for the industrial design of bimetal conical-cylindrical cup hydroforming. Forming circumstances for the perfect and imperfect parts were concluded through adaptive FEA using the ANSYS parametric design language. Effective parameters, including pressure loading path, layer placement order, and thickness ratio, were investigated for hydroforming of Al/St and Cu/St composite sheets. Experimental tests were implemented to validate adaptive finite element results. Rupture failure upon the pressure path occurred on the contact area between the blank and punch tip radius at low pressures and on the transition area of the conical-cylindrical portion at high pressures. The proposed method is applicable for any cylindrical, conical, or cylindrical/conical shapes with different materials and dimensions. Therefore, this method is beneficial as a practical design tool for engineers and researchers working in the process design of hydroformed shell products.

  9. 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%.

  10. 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.

  11. Analysis of Welding Technology about Bimetal-lined Pipe%双金属复合管焊接技术分析

    Institute of Scientific and Technical Information of China (English)

    李发根; 孟繁印; 郭霖; 常泽亮

    2014-01-01

    双金属复合管的焊接接头结构复杂,焊接难度较大。通过对双金属复合管端面处理工艺和对接焊接工艺分析,提出了端部堆焊工艺较端部封焊工艺易于焊接但不够经济的现状,指出对于薄壁小直径双金属复合管道的焊接宜采用合金焊丝对接焊工艺,而对于厚壁大直径双金属复合管道则宜采用过渡焊方法焊接。另外,还分析了当前的焊接评定标准,强调了制定适宜复合管的焊接工艺评定标准的必要性。%The welded joint structure of bimetal-lined pipe is complex and is difficult to be welded. Through analysis on pipe end treatment and butt welding procedure for bimetal-lined pipe, it indicated the overlaying was easy to weld but not to be economic comparing with seal welding, it also pointed out that alloy wire butt welding might be used to weld thin wall and small diameter bimetal-lined pipes, while for thick wall and large diameter pipes the buffer layer welding method can be used. Additionally, the existing standards about welding procedure qualification were analyzed in the paper, and the necessity of drafting welding procedure qualification standard about bimetal-lined pipes was emphasized.

  12. 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。

  13. 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.

  14. Effect of cold-rolling and annealing on interfacial structures and properties of A500/steel bimetal strip

    Institute of Scientific and Technical Information of China (English)

    LI Bao-mian; HAN Jian-fen; XU Guang-ming; CUI Jian-zhong

    2005-01-01

    The effect of cold-rolling, by both a series of small passes and single-pass with different deformations as well as the subsequent annealing, on the interfacial structures and properties of A500 (AlSn8 Pb2Si2.5 Cu0.8 Cr0.2 )/steel bimetal strip produced by liquid-solid roll cladding was investigated. Experimental results of the cold-rolling by a series of small passes show that the interfacial bonding strength increases slightly when the total deformation is less than 7.32% and then decreases gradually with the increase in deformation. Subsequent annealing has no effect on the interfacial structures and properties. The effect of cold-rolling by single-pass less than 33.2 % deformation on the interfacial structures and properties is the same as that of multi-pass cold-rolling, whereas cold-rolling by singlepass more than 33. 2% deformation followed by annealing at 350 ℃ for 2. 5 h can make the interfacial bonding strength increase to a great extent. Metallographic examination of the interface shows that there exist only transverse cracks within the interfacial layer and the clad strip does not split along the interface during cold-rolling if the thickness of interfacial layer is less than 4 - 5 μm. The thick interfacial layer(>5 - 6 μm), however, crumbles during cold-rolling, thus resulting in the splitting of the clad strip.

  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. 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.

  17. Hydroisomerization of n-heptane over bimetal-bearing H3PW12O40 catalysts supported on dealuminated USY zeolite

    Institute of Scientific and Technical Information of China (English)

    WEI RuiPing; GU YanBo; WANG Jun

    2008-01-01

    The bimetal-bearing (CePt or LaPt) 12-tungstophosphoric acid (H3PW12O40 (PW)) catalysts supported on dealuminated USY zeolite (DUSY) were prepared by impregnation and characterized by XRD, BET, IR, and H2-chemisorption.Their catalytic activities were tested in the hydroisomerization of n-heptane with a continuous atmospheric fixed-bed reactor.After the steam treatment combined with the acid leaching, as well as the supporting with PW and the bimetals, the DUSY support retains the Y zeolite porosity and the PW well keeps its Keggin structure in catalysts.The doping of Ce into the catalysts enhances the dispersion of Pt on the catalyst surface.The Pt-bearing PW catalysts doped with Ce or La, especially Ce, exhibit much higher catalytic activity and selectivity than the catalysts without dopants at lowered re-action temperatures.At the optimal reaction conditions, i.e., the reaction temperature of 250℃ and WHSV of 1.4 h-1, the catalyst with a Pt loading of 0.4%, PW loading of 10% and a molar ratio of Ce to Pt of 15:1 shows a conversion of n-heptane of 70.3% with a high selectivity for isomerization products of 94.1%.

  18. Hydroisomerization of n-heptane over bimetal-bearing H3PW12O40 catalysts supported on dealuminated USY zeolite

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The bimetal-bearing (CePt or LaPt) 12-tungstophosphoric acid (H3PW12O40 (PW)) catalysts supported on dealuminated USY zeolite (DUSY) were prepared by impregnation and characterized by XRD, BET, IR, and H2-chemisorption. Their catalytic activities were tested in the hydroisomerization of n-heptane with a continuous atmospheric fixed-bed reactor. After the steam treatment combined with the acid leaching, as well as the supporting with PW and the bimetals, the DUSY support retains the Y zeolite porosity and the PW well keeps its Keggin structure in catalysts. The doping of Ce into the catalysts enhances the dispersion of Pt on the catalyst surface. The Pt-bearing PW catalysts doped with Ce or La, especially Ce, exhibit much higher catalytic activity and selectivity than the catalysts without dopants at lowered reaction temperatures. At the optimal reaction conditions, i.e., the reaction temperature of 250℃ and WHSV of 1.4 h1, the catalyst with a Pt loading of 0.4%, PW loading of 10% and a molar ratio of Ce to Pt of 15:1 shows a conversion of n-heptane of 70.3% with a high selectivity for isomerization products of 94.1%.

  19. Cu-Co bi-metal catalyst prepared by perovskite CuO/LaCoO3 used for higher alcohol synthesis from syngas

    Institute of Scientific and Technical Information of China (English)

    Yuzhen Fang; Yuan Liu; Wei Deng; Junhai Liu

    2014-01-01

    Cu-Co bi-metal catalysts derived from CuO/LaCoO3 perovskite structure were prepared by one-step citrate complexing method, and the structure evolution reaction from CuO/LaCoO3 to Cu-Co2C/La2O2CO3 under H2 pretreatment was investigated by techniques of XRD, TPR and TEM. The results suggest that a much higher dispersion of copper significantly enhanced the reduction of cobalt, and a stronger interaction between copper and cobalt ions in LaCoO3 particles led to the formation of bi-metallic Cu-Co particles in the reduced catalysts and the enrichment of Co on the surface of bimetallic particles. The prepared catalysts were highly active and selective for the alcohol synthesis from syngas due to the presence of copper-modified Co2 C species.

  20. 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.

  1. 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

  2. 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

  3. Well-organized raspberry-like Ag@Cu bimetal nanoparticles for highly reliable and reproducible surface-enhanced Raman scattering

    Science.gov (United States)

    Lee, Jung-Pil; Chen, Dongchang; Li, Xiaxi; Yoo, Seungmin; Bottomley, Lawrence A.; El-Sayed, Mostafa A.; Park, Soojin; Liu, Meilin

    2013-11-01

    Surface-enhanced Raman scattering (SERS) is ideally suited for probing and mapping surface species and incipient phases on fuel cell electrodes because of its high sensitivity and surface-selectivity, potentially offering insights into the mechanisms of chemical and energy transformation processes. In particular, bimetal nanostructures of coinage metals (Au, Ag, and Cu) have attracted much attention as SERS-active agents due to their distinctive electromagnetic field enhancements originated from surface plasmon resonance. Here we report excellent SERS-active, raspberry-like nanostructures composed of a silver (Ag) nanoparticle core decorated with smaller copper (Cu) nanoparticles, which displayed enhanced and broadened UV-Vis absorption spectra. These unique Ag@Cu raspberry nanostructures enable us to use blue, green, and red light as the excitation laser source for surface-enhanced Raman spectroscopy (SERS) with a large enhancement factor (EF). A highly reliable SERS effect was demonstrated using Rhodamine 6G (R6G) molecules and a thin film of gadolinium doped ceria.Surface-enhanced Raman scattering (SERS) is ideally suited for probing and mapping surface species and incipient phases on fuel cell electrodes because of its high sensitivity and surface-selectivity, potentially offering insights into the mechanisms of chemical and energy transformation processes. In particular, bimetal nanostructures of coinage metals (Au, Ag, and Cu) have attracted much attention as SERS-active agents due to their distinctive electromagnetic field enhancements originated from surface plasmon resonance. Here we report excellent SERS-active, raspberry-like nanostructures composed of a silver (Ag) nanoparticle core decorated with smaller copper (Cu) nanoparticles, which displayed enhanced and broadened UV-Vis absorption spectra. These unique Ag@Cu raspberry nanostructures enable us to use blue, green, and red light as the excitation laser source for surface-enhanced Raman spectroscopy

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. Dechlorination of HCB by Bimetals Based on Zero Valent Iron%基于零价铁的双金属体系对六氯苯还原脱氯研究

    Institute of Scientific and Technical Information of China (English)

    曾宪委; 刘建国; 聂小琴

    2013-01-01

    利用Ag、Pb和Cu作为催化金属与微米级铁粉制成不同的双金属体系还原脱氯六氯苯(hexachlorobenzene,HCB),探讨不同催化金属种类、不同双金属添加量以及不同离子强度3种因素对HCB脱氯效率的影响,并剖析双金属催化条件下HCB的脱氯规律.结果表明,微米级铁粉对HCB几乎无还原脱氯效果,添加Ag、Pb和Cu对HCB均具有良好的催化脱氯能力,当Ag/Fe、Pb/Fe和Cu/Fe的最佳比例分别为0.2%、0.5%和1%时,反应2h后HCB的脱氯率分别达到93.5%、88.5%和49.6%;同时,由于催化金属均匀附着在零价铁表面可以形成更多的微型原电池,故增加双金属投加量可有效提高HCB脱氯速率,0.1 g Pb/Fe对HCB脱氯率为38.3%,而0.8 g Pb/Fe对HCB脱氯率可达到88.6%;另外,离子强度增大对HCB的脱氯也有一定促进作用,在Na2SO4浓度分别为0、0.05和0.5 mol· L-1的3个反应器中,反应2h后HCB脱氯率分别达到93.5%、98.O%和98.9%.%Based on the reducing capacity of zero valent iron, the study investigated the behavior of dechlorination of hexachlorobenzene by bimetals synthetized using Fe with Ag, Pb or Cu as catalysts,respectively. The results showed that bimetals could dechlorinate HCB faster than Fe(0) did, the optimal ratios of Ag/Fe, Pb/Fe and Cu/Fe were 0.2% , 0.5% and 1%. After reacting 2 hours, the dechlorination rates of HCB by Ag/Fe, Pb/Fe and Cu/Fe were 93.5%, 88.5% and 49.6% respectively. The catalyst metal distribution had a great effect on the reductive dechlorination capacity of the bimetal systems, due to more galvanic cells produced by well-distributed catalyst metal and iron. Increasing the amount of bimetal was an effective way to promote HCB dechlorination rate, 88.6% HCB was degraded in 2 h by 0.8 g Pb/Fe while only 38.3% HCB was degraded by 0. 1 g Pb/Fe. Besides, HCB dechlorination could be enhanced a little with increasing ionic strength, the HCB dechlorination rates were 93.5% , 98.0% and 98

  9. 一种大口径双金属复合管半自动氩弧焊接工艺%A semi - automatic TIG welding process for large - diameter bimetal composite pipe

    Institute of Scientific and Technical Information of China (English)

    王京

    2014-01-01

    采用半自动氩弧焊焊接工艺,对大口径(DN >300)双金属复合管进行焊接,包括焊前预处理、根焊、过渡焊、填充焊、盖面焊,解决了双金属复合管仅靠手工焊接施工造成的焊接速度慢、工人劳动强度大及焊接热输出量大而影响不锈钢层耐蚀性等难题。%A Semi - automatic TIG welding process for large diameter(DN > 300)bimetal composite pipe for welding,including pre-treatment before welding,root welding,soldering transition,filling welding,cosmetic welding,solved the slow speed,high labor inten-sity of workers and the welding heat output the amount is large and the effects of stainless steel corrosion resistance and other problems of the double metal composite pipe by hand welding.

  10. 放电等离子烧结制备YG20C/Cr12MoV双金属复合材料%Preparation of YG20C/Cr12MoV steel bimetal composite by spark plasma sintering

    Institute of Scientific and Technical Information of China (English)

    吕玉廷; 蒋朋; 曹佑青; 吴建峰; 徐金富

    2013-01-01

    用M42和YG20C质量比为2∶1的混合粉末,利用放电等离子烧结技术制备了YG20C/Cr12MoV双金属复合材料,并对过渡层与Cr12MoV、YG20C两侧界面的微观组织、元素扩散及显微硬度进行了分析.结果表明,Cr12MoV钢内表面有一层宽度约为60 μm的晶粒异常长大区,其硬度较低,对复合材料的连接性能产生不利影响;SPS烧结过程中,粉末颗粒之间的火花放电使Cr12MoV钢表层产生高温是造成晶粒异常长大、脱碳和贫Cr的主要原因;过渡层与Cr12MoV、YG20C界面过渡区宽度分别约为60 μm和40μm,两界面处元素发生扩散,显微硬度呈梯度增加,连接性能良好.%The YG20C/Cr12MoV steel bimetal composite was prepared by spark plasma sintering technique,using the mixture powder of M42 and YG20C (mass ratio of M42/YG20C =2∶1).Microstructure,elements diffusion and micro-hardness of interfaces between transition layer and Cr12MoV steel and the cemented carbide were analyzed.The results show that abnormal growth grains region whose width is approximately 60 μm is found on the internal surface of Cr12MoV.The abnormal growth grains with lower hardness has an harmful impact on the adhesiveness of the composite.Higher temperature of Cr12MoV surface layer which is caused by electrical discharges between powder particles in the SPS process results in abnormal grains growth,surface decarburization and chromium loss.The widths of transition areas between transition layer/Cr12MoV,YG20C interfaces are about 60 μm and 40 μm,respectively,where elements self-diffusion happens,micro-hardness appears gradient increase and the connection properties are good.

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

    Science.gov (United States)

    Amani, H.; Soltanieh, M.

    2016-08-01

    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.

  12. 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

  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. 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.

  15. 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.

  16. 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).

  17. 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.

  18. 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...

  19. 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

    2016-05-01

    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.

  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. Encapsulation of Mono- or Bimetal Nanoparticles Inside Metal-Organic Frameworks via In situ Incorporation of Metal Precursors.

    Science.gov (United States)

    Chen, Liyu; Chen, Xiaodong; Liu, Hongli; Li, Yingwei

    2015-06-10

    A facile, in situ metal precursor incorporation strategy is established for good control over the location and composition of metal nanoparticles within metal-organic frameworks (MOFs). This one-step metal precursor incorporation route is successfully applied to the fabrication of ultrafine Pd, Ni, and PdNi alloys to be selectively encapsulated inside the pores of MOFs, achieving superior catalytic activity and stability in the hydrogenation of nitrobenzene.

  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. Design Analysis of Cold Roll Bonding Mill for Bimetal Composites%双金属冷复合轧机的设计初探

    Institute of Scientific and Technical Information of China (English)

    张京诚

    2015-01-01

    通过开发设计双金属冷复合轧机,对冷复合轧制的特殊工艺进行了针对性研究,最终采用经济合理的参数选择与方案配置完成了轧机设计,并成功生产出合格产品;同时对冷复合轧机的应用前景提出了展望.

  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. 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.

  7. 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.

  8. 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

  9. Study on bimetal hacksaw blades industry in China%中国双金属带锯条行业研究

    Institute of Scientific and Technical Information of China (English)

    刘年红

    2010-01-01

    双金属带锯条具有切削精度高、材料损耗低、工作效率高等优点.在金属切割领域,双金属带锯条的发明被誉为"切削工艺的一场革命".文章着重介绍了全球及中国双金属带锯条市场容量.

  10. 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 ...

  11. Evaluation of diffusion and phase transformation at Ag/Al bimetal produced by cold roll welding%冷轧焊接制备Ag/Al双金属材料的扩散和相转变

    Institute of Scientific and Technical Information of China (English)

    Hossein OLIA; Mehrdad ABBASI; Seyed Hossein RAZAVI

    2012-01-01

    通过轧制Al条和Ag条制备Ag/Al双金属条.为使Al和Ag条之间发生冷焊,对表面进行处理并设置不同的轧制压下量.实验表明:发生冷焊的最小临界轧制厚度压下量为70%,相当于轧制形状因子0.1630.对双金属条进行均匀化退火,于400℃保温不同时间.利使用扫描电子显微镜观察Al/Ag界面,研究可能存在的硬脆相.通过EDS分析和线扫描分析退火时间对扩散距离和相转变的影响.在界面上Ag侧观察到一个扩散区,其宽度随退火时间的延长而增加.退火处理3h后在靠近界面处观察到一些δ相,而且随着退火时间的延长,δ相变得更粗、更连续.显微硬度测试表明:尽管通过均匀化退火生成δ相,界面硬度却有所降低.%Aluminum and silver strips were cold welded by rolling and a bimetallic strip was produced.To create cold weld between Al and Ag,mating surfaces were specially prepared and various rolling thickness reductions were applied.The minimum critical thickness reduction to begin cold weld was specified as 70% which equals 0.1630 critical rolling shape factors.The bimetallic strips were treated by diffusion annealing at 400 ℃ and various annealing time.The Al/Ag interface of strips was observed by scanning electron microscope to investigate the formation of hard and brittle probable phases.The effect of anneal time on diffusion distance and phase transformation was also analysed by EDS analysis and line scan.A diffusion region along the interface in the Ag side was observed and its width increased with prolonging annealing time.Some δ phases were detected close to the interface after anneal treating for 3 h and δ phase was thicker and more continuous by increasing annealing time.The microhardness measurement showed that in spite of formation ofδ phase due to diffusion annealing,the interface hardness was reduced.

  12. 高锡铝合金-钢双金属冷轧复合机理研究%Research on Cold-rolled Bonding Mechanism of High-tin Aluminum Alloy and Steel Bimetal

    Institute of Scientific and Technical Information of China (English)

    崔国明; 李兴霞; 曾建民

    2013-01-01

    采用冷轧复合工艺制得高锡铝合金-钢双金属材料,分别对冷轧态和再结晶退火态双金属的结合界面进行组织观察、结合强度测试及结合机理分析.结果表明:冷轧态双金属中锡相呈带状分布,再结晶态双金属中锡相呈“孤岛状”均匀分布;双金属界面形态结合良好,冷轧态双金属的界面结合机理为冷压焊合和机械咬合,再结晶态界面结合机理为冷压焊合、机械咬合和冶金结合三种;经350℃×2h退火后,双金属结合强度达92.6 MPa,比冷轧态提高了27%.

  13. Study of A Tearing Method Measuring Bonding Strength of Cold Rolling Cladding Bimetal Strip%一种测试冷轧双金属复合板撕裂结合强度方法的研究

    Institute of Scientific and Technical Information of China (English)

    林大超; 白海龙; 史庆南

    2000-01-01

    提出了一种用撕裂法测试冷轧双金属复合板结合强度的方法,对制样过程、原理及撕裂过程中的三种变形方式进行了论述,给出了相关的实验测试结果,并对实验结果进行了分析和讨论.

  14. 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.

  15. 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。

  16. 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

  17. The Effect of Cryogenic Treament on the Cutting Bimetal Power Hacksaw Blades%深冷处理对双金属带锯条切削性能的影响

    Institute of Scientific and Technical Information of China (English)

    李海丽; 贾春德; 莫春立

    2003-01-01

    应用实验手段研究了深冷处理对双金属机用带锯条切削性能的影响,包括对刃部材料M42钢的红硬性、耐磨性的研究以及对背部材料Rm80钢疲劳性能的分析.结果表明:深冷处理不仅可提高M42钢的红硬性、耐磨性;同时提高了Rm80钢的抗疲劳性能,延长刀具的使用寿命,通过对比回火前和回火后+深冷处理工艺,发现采用回火后+深冷处理工艺能显著提高材料寿命.

  18. 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

  19. 零价铁、镍-铁和铜-铁双金属对四氯乙烯的脱氯性能研究%Study on Dechlorination Capabilities of Zero-valent Iron,Nickel-Iron or Copper-Iron Bimetal on Tetrachloroethylene

    Institute of Scientific and Technical Information of China (English)

    何小娟; 李旭东; 汤明皋; 刘菲; 周琪

    2006-01-01

    研究了零价铁、镍-铁和铜-铁双金属对四氯乙烯(PCE)的还原性脱氯性能.实验结果表明,零价铁、镍-铁和铜-铁双金属对PCE的脱氯反应符合准一级反应动力学方程;双金属对PCE的脱氯反应速率高于零价铁,镍-铁双金属对PCE的脱氯反应速率常数是零价铁的2.486倍;镍-铁和铜-铁双金属可使PCE完全脱氯,零价铁在对PCE脱氯的过程中产生一定量的三氯乙烯;增加金属质量,可提高PCE的脱氯反应速率;金属颗粒越小,越有利于PCE脱氯反应.

  20. 一种新型三维锌钠双金属配合物的水热合成及其晶体结构%Hydrothermal Synthesis and Crystal Structure of a New Three-dimensional Zinc Sodium Bi-metal Complexes

    Institute of Scientific and Technical Information of China (English)

    梁鹏; 岑健梅; 覃忠娟; 尹显洪

    2013-01-01

    水热法合成了一个新的Zn、Na双金属配合物,poly[di-μ2-aqua-di-μs-oxalato-μ4-oxalato -disodiumdizine(ID],[NaZn(C2O4)3/2(H2O)]n.通过X-射线单晶衍射仪测定其结构,结果表明:晶体为单斜晶系,P2(1)/c空间群,晶胞参数a=5.8834(14)(A),b=15.687(4)(A),c=6.9780(16)(A),α=90.00°,β=100.343(2)°,γ=90.00°,V=633.6(3) (A)3,Z=4.在非对称的结构中,由两个晶体学独立的草酸组,其中一个在反演中心,另外一个在一般位置每个锌离子为六配位,钠离子为七配位,配合物通过配位螯合及草酸桥联形成三维超分子结构,配位水与另外两个草酸根离子的氧形成氢键,并参与了配合物的空间连接,使配合物的空间结构更加稳定.

  1. 双金属带锯条切削34Mn2V合金结构钢的切削性能的研究%A Study on the Cutting Performance Using Bimetal Hacksaw Blades for Cutting 34Mn2V Alloy Structural Steel

    Institute of Scientific and Technical Information of China (English)

    贾春德; 李海丽

    2004-01-01

    应用实验手段研究了经过深冷处理的双金属带锯条在切削正火态34Mn2V合金结构钢时的切削性能,并求出了切削34Mn2V合金结构的刀具耐用度公式.结果表明:经过深冷处理的双金属带锯条具有良好的切削性能,这种良好的切削性能主要是由于深冷处理引起材料内部微观结构的变化带来的.

  2. ESTUDIO DE NANOPARTÍCULAS BIMETÁLICAS DE Rh-Pd SINTETIZADAS POR VÍA ELECTROQUÍMICA

    Directory of Open Access Journals (Sweden)

    Maraid Sosa

    2011-01-01

    Full Text Available En este trabajo, se reporta la síntesis de nanopartículas bimetálicas de Rh-Pd por medio de la reducción de iones metálicos por electrólisis a corriente constante (cronopotenciometría, utilizando bromuro de tetrapropilamonio (TPABr como estabilizante y electrolito en un medio de agua/etanol. La caracterización por Microscopía Electrónica de Transmisión (MET mostró que a medida que la corriente es más negativa, el tamaño de las nanopartículas disminuye. Los patrones de difracción de electrones obtenidos de éste estudio mostraron que en las nanopartículas bimetálicas de Rh-Pd se encuentran presentes fases bimetálicas con presencia de oxigeno. De acuerdo a lo anterior, y con los estudios de voltamperometría cíclica y espectroscopía de UV-visible se puede decir que las nanopartículas bimetálicas de Rh-Pd son nanoaleaciones. Los resultados de espectroscopía de UV- visible sugieren que las nanopartículas bimetálicas y monometálicas de Rh-Pd, Rh y Pd poseen plasmones de superficie.

  3. 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...

  4. 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

  5. Catalytic hydrotreatment of fast-pyrolysis oil using non-sulfided bimetallic Ni-Cu catalysts on a delta-Al2O3 support

    NARCIS (Netherlands)

    Ardiyanti, A. R.; Khromova, S. A.; Venderbosch, R. H.; Yakovlev, V. A.; Heeres, H. J.

    2012-01-01

    Fast pyrolysis oil from lignocellulosic biomass is an attractive energy carrier. However, to improve the product characteristics such as a reduced polarity and higher thermal stability, upgrading is required. We here report activities on the catalytic hydrotreatment of fast pyrolysis oil using bimet

  6. Dechlorination of Aromatic Chlorides in Aqueous System Catalyzed by Functionalized MontK10 Supported Palladium-tin

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel bisupporter bimetal catalyst PVP-PdCl2-SnCl4/MontK10-PEG400, using for dehalogenation of insoluable aromatic halides in aqueous system, has shown high dechlorination activity and selectivity, without any organic solvent or phase transfer catalyst. The conversion of aromatic chlorides can reach 100%. The catalyst is easy to prepare and has good reusability.

  7. Passivation of bimetallic catalysts used in water treatment: prevention and reactivation.

    Science.gov (United States)

    Chen, Jianming; Gillham, Robert W; Gui, Lai

    2013-01-01

    With respect to degradation rates and the range in contaminants treated, bimetals such as Ni-Fe or Pd-Fe generally outperform unamended granular iron. However, the catalytic enhancement is generally short-lived, lasting from a few days to months. To take advantage of the significant benefits of bimetals, this study aims at developing an effective method for the rejuvenation of passivated bimetals and alternatively, the prevention of rapid reactivity loss of bimetals. Because the most likely cause of Ni-Fe and Pd-Fe passivation is the deposition of iron oxide films over the catalyst sites, it is hypothesized that removal of the iron oxide films will restore the lost reactivity or avoiding the deposition of iron oxide films will prevent passivation. Two organic ligands (ethylenediaminetetraacetic acid (EDTA), and [s,s]-ethylenediaminedisuccinate acid ([s,s]-EDDS)) and two acids (citric acid and sulphuric acid) were tested as possible chemical reagents for both passivation rejuvenation and prevention. Trichloroethene (TCE) and Ni-Fe were chosen as probes for chlorinated solvents and bimetals respectively. The test was carried out using small glass columns packed with Ni-Fe. TCE solution containing a single reagent at various concentrations was pumped through the Ni-Fe columns with a residence time in the Ni-Fe of about 6.6 min. TCE concentrations in the influent and effluent were measured to evaluate the performance of each chemical reagent. The results show that (i) for passivated Ni-Fe, flushing with a low concentration of acid or ligand solution without mechanical mixing can fully restore the lost reactivity; and (ii) for passivation prevention, adding a small amount of a ligand or an acid to the feed solution can successfully prevent or at least substantially reduce Ni-Fe passivation. All four chemicals tested are effective in both rejuvenation and prevention, but sulphuric acid and citric acid are considered to be the most practical reagents due to their

  8. 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).

  9. 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.

  10. 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.

  11. 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...

  12. 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.

  13. 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

  14. Analysis of Bonding Behavior and Critical Reduction of Two-Layer Strips in Clad Cold Rolling Process

    Science.gov (United States)

    Maleki, H.; Bagherzadeh, S.; Mollaei-Dariani, B.; Abrinia, K.

    2013-04-01

    In recent years, two-layer metallic sheets have been increasingly used in various industries to create combined functions. Among cladding methods, the cold rolling is most widely used in producing bimetallic sheets. In this research, to thoroughly provide guidelines for cold rolling of bimetal strip, an attempt has been made to develop an analytical model based on upper bound method. Also, the bonding strength and critical reduction were calculated using upper bound theorem and the finite element simulation was used for Al/St bimetallic strip. Finally, an experimental study was run for our model to be verified analytically and numerically. Results show that the bonding strength of strips increases with increasing the total thickness reduction of bimetal strips and because of subsequent occurrence of strips bonding in roll gap, increasing the yield strength of base layer gives rise to critical reduction. Through the study, it becomes clear that the proposed analytical model is applicable for simulating the cold rolling process of the two-layer strips and is capable to broaden our knowledge in manufacturing and production of bimetal strips and sheets.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. A novel strategy for the design of smart supramolecular gels: controlling stimuli-response properties through competitive coordination of two different metal ions.

    Science.gov (United States)

    Lin, Qi; Sun, Bin; Yang, Qing-Ping; Fu, Yong-Peng; Zhu, Xin; Zhang, You-Ming; Wei, Tai-Bao

    2014-09-21

    By rationally introducing Ca(2+) and Fe(3+) into a supramolecular gel, a bimetal-gel CaFeG was prepared. CaFeG could reversibly "turn-on" its fluorescence upon sensing H2PO4(-) with specific selectivity under gel-gel states through the competitive coordination of Ca(2+) and Fe(3+) with gelators and H2PO4(-). Thus, CaFeG could act as a H2PO4(-) test kit and could be utilised in rewritable security display materials.

  20. 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

  1. 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...

  2. 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.

  3. 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.

  4. Oxidación de propileno sobre catalizadores Pt-Cu/y-alúmina. Primera Parte: Caracterización de catalizadores de Pt-Cu/y-alúmina por quimisorción de H2

    Directory of Open Access Journals (Sweden)

    Luis M. Carballo

    2011-02-01

    Full Text Available En este trabajo se analiza el efecto de la composición de catalizadores de Pt-Cu/y-alúmina sobre el área superficial reactiva correspondiente a la oxidación total de propileno. Los ensayos experimentales se efectuaron en un reactor diferencial que se usó tanto para la caracterización del catalizador "in situ" mediante la medición de la quimisorción selectiva de H2. Además, se discuten los efectos y las interacciones bimetálicas que ocurren con frecuencia en los catalizadores soportados. A partir de los estudios de adsorción química de H2 sobre los catalizadores soportados de Pt-Cu se encontró, mediante la aplicación de la teoría de la solución regular a la superficie de los cristales y teniendo en cuenta que el H2 se adsorbe químicamente solamente sobre los átomos superficiales de Pt (se observó que el hidrógeno no se quimisorbe sobre el Cu, que los átomos de Cu se segregan a la superficie de los cristalitos bimetálicos.

  5. High-temperature deformation behavior of titanium clad steel plate

    Institute of Scientific and Technical Information of China (English)

    Shang-Wu Zeng; Ai-Min Zhao; Hai-Tao Jiang; Xiao-Qian Yan; Ji-Xiong Liu; Xiao-Ge Duan

    2015-01-01

    In this paper,the single-pass hot compression experiment of titanium clad steel plate was carried out by Gleeble-3500 thermal mechanics simulation test machine,and the effect of deformation temperature (T),strain rate (4),thickness ratio (k),and friction coefficient (μ) on flow pattern of the metal and stress in the deformation zone was analyzed.The results show that the metal flow behavior and the stress during compressive deformation depend strongly on the deformation temperature.At 800 and 850 ℃,the bimetal can flow uniformly,while at 900 ℃,the TA2 flows faster than Q235B,and the phenomenon of TA2 wrapping Q235B is observed.The metal flow of the bimetal material will coordinate each other through the bonding interface.It is noted that the stress increases with the increase of the the andμ and decreases when the metal flows along the contact area.

  6. 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.

  7. Influence of Molecular Sieve Supported Metal Oxides on the Desulfurization in Catalytic Cracking of Sulfur-containing Model Compounds and Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    申宝剑; 李海丽; 李会峰; 鲍晓军; 周小虹

    2003-01-01

    Zn, La, Zr, Sn and Ti loaded molecular sieves were prepared by impregnation method. Conversions of benzothiophene and dibenzothiophene over the metal oxides modified ultra stable zeolite Y(USY), ZSM-5, β and MSU-2 molecular sieve catalysts were investigated by means of micro-activity test (MAT) experiments. The results showed that Zn and La loaded catalysts were better than the other metals, and ZSM-5 with lower SiO2/Al2O3 mole ratio showed better results than those with higher SiO2/Al2O3 as far as desulfurization reaction is considered. A comparison of the desulfurization activities of the La/Zn-USY catalyst with USY catalyst indicated that the bimetal loaded USY catalyst gave good products selectivity when sulfur containing heavy oil was used as the feedstock. The sulfur content in gasoline fraction was decreased by 25%, and there was no loss in the Research Octane Number.

  8. Influence of Molecular Sieve Supported Metal Oxides on the Desulfurization in Catalytic Cracking of Sulfur-containing Model Compounds and Hydrocarbons%金属担载分子筛对含硫模型化合物和含硫烃的催化裂化脱硫反应的影响

    Institute of Scientific and Technical Information of China (English)

    申宝剑; 李海丽; 李会峰; 鲍晓军; 周小虹

    2003-01-01

    Zn, La, Zr, Sn and Ti loaded molecular sieves were prepared by impregnation method. Conversions of benzothiophene and dibenzothiophene over the metal oxides modified ultra stable zeolite Y(USY), ZSM-5, β and MSU-2 molecular sieve catalysts were investigated by means of micro-activity test (MAT) experiments. The results showed that Zn and La loaded catalysts were better than the other metals, and ZSM-5 with lower SiO2/Al2O3 mole ratio showed better results than those with higher SiO2/Al2O3 as far as desulfurization reaction is considered. A comparison of the desulfurization activities of the La/Zn-USY catalyst with USY catalyst indicated that the bimetal loaded USY catalyst gave good products selectivity when sulfur containing heavy oil was used as the feedstock. The sulfur content in gasoline fraction was decreased by 25%, and there was no loss in the Research Octane Number.

  9. MEMS based pyroelectric thermal energy harvester

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. 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.

  11. 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.

  12. Thermal Stability and Reductive Property of CexZr1-xO2 Solid Solution Doped Simultaneously by Fe, Mn or Fe, Cu

    Institute of Scientific and Technical Information of China (English)

    Yan Zhongjun; Yang Dong; Wen Mingfen; Chen Jing; Wang Jinggang; Gu Yongwan

    2005-01-01

    CexZr1-xO2 complex oxides doped by transition metal(Fe, Mn, Cu) were prepared by precipitation method. Thermal stability of samples was characterized by XRD, surface areas were measured by BET method and reductive property was characterized by TPR. The results show that MnO2 can be dispersed in solid solution after calcined at 1273 K, when the loading is 12%, while Fe and Cu is easy to separate from samples at this temperature. Samples doped simultaneously by Fe, Mn or Fe, Cu demonstrated high reactive property at low temperature. The starting reduction temperature are 413 and 373 K, respectively. TPR results also show a broad range of reductive temperature exists in these bi-metal doped samples.

  13. 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.

  14. 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.

  15. Mechanics property Study for Interface Bim Composite of Zinc Alloy ZAS35/Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    陈基勇; 耿浩然; 杨爱玲

    2002-01-01

    The distortional fields of interface-U-field and V-field-have been obtained after the mechanics property for the geometric distortion of interface of cracked zinc alloy ZAS35/carbon steel is analyzed by means of a laser moire interferometry. The optimum cast preheating temperature has been decided in the light of the experiment of shear strength. After the microstructure of interface of bimetal composite of zinc alloy ZAS35/carbon steel is analyzed and studied with a X ray diffraction and an electronic scanning mirror (ESM), the phase component of metallurgical bond of interface of zinc alloy ZAS35/carbon steel has been gained, and the results of interface scan of distribution of elements Fe/Zn have been obtained with the dip coating temperature of 700(C. The above working theory, the experimental technology and its results will be introduced in this paper, and its results will be analyzed.

  16. 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...

  17. 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.

  18. Interaction of a solar space heating system with the thermal behavior of a building

    Energy Technology Data Exchange (ETDEWEB)

    Vilmer, C.; Warren, M.L.; Auslander, D.

    1980-12-01

    The thermal behavior of a building in response to heat input from an active solar space heating system is analyzed to determine the effect of the variable storage tank temperature on the cycling rate, on-time, and off-time of a heating cycle and on the comfort characteristics of room air temperature swing and of offset of the average air temperature from the setpoint (droop). A simple model of a residential building, a fan coil heat-delivery system, and a bimetal thermostat are used to describe the system. A computer simulation of the system behavior has been developed and verified by comparisons with predictions from previous studies. The system model and simulation are then applied to determine the building response to a typical hydronic solar heating system for different solar storage temperatures, outdoor temperatures, and fan coil sizes. The simulations were run only for those cases where there was sufficient energy from storage to meet the building load requirements.

  19. 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 ...

  20. 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.

  1. 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

  2. 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

  3. 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

    2016-03-21

    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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. HIDROGENACIÓN SELECTIVA DE CITRAL EN FASE LÍQUIDA SOBRE CATALIZADORES Ir–Fe/TiO2 REDUCIDOS A ALTA TEMPERATURA

    Directory of Open Access Journals (Sweden)

    Hugo Alonso Rojas Sarmiento

    2008-03-01

    Full Text Available En este trabajo se muestra la hidrogenación del citral sobre catalizadores de Ir e Ir-Fe/TiO2 reducidos a 773 K (HTR. Lapreparación de los catalizadores se realizó con soluciones acuosas de H2IrCl6 para obtener una carga de metal al 1% y por impregnación de FeCl3, lo cual permitió obtener los correspondientes sistemas bimetálicos. Todos los catalizadores presentaron una selectividad del 100% hacia los alcoholes insaturados (geraniol y nerol. La caracterización de los sólidos se efectuó mediante quimisorción selectiva de hidrógeno a 298 K, DRX, TPR y XPS. Los resultados de actividad intrínseca y selectividad se explican con base en los datos de caracterización que ponen en evidencia el efecto de una fuerte interacción metal-soporte (SMSI. También se muestra la descripción de un reactor tipo STR donde se efectuó la evaluación de la actividad intrínseca del catalizador.

  9. 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.

  10. 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.

  11. Highly active Ce 1- xCu xO 2 nanocomposite catalysts for the low temperature oxidation of CO

    Science.gov (United States)

    Mai, Hailing; Zhang, Dengsong; Shi, Liyi; Yan, Tingting; Li, Hongrui

    2011-06-01

    A series of Ce 1- xCu xO 2 nanocomposite catalysts with various copper contents were synthesized by a simple hydrothermal method at low temperature without any surfactants, using mixed solutions of Cu(II) and Ce(III) nitrates as metal sources. These bimetal oxide nanocomposites were characterized by means of XRD, TEM, HRTEM, EDS, N 2 adsorption, H 2-TPR and XPS. The influence of Cu loading (5-25 mol%) and calcination temperature on the surface area, particle size and catalytic behavior of the nanocomposites have been discussed. The catalytic activity of Ce 1- xCu xO 2 nanocomposites was investigated using the test of CO oxidation reaction. The optimized performance was achieved for the Ce 0.80Cu 0.20O 2 nanocomposite catalyst, which exhibited superior reaction rate of 11.2 × 10 -4 mmol g -1 s -1 and high turnover frequency of 7.53 × 10 -2 s -1 (1% CO balanced with air at a rate of 40 mL min -1, at 90 °C). No obvious deactivation was observed after six times of catalytic reactions for Ce 0.80Cu 0.20O 2 nanocomposite catalyst.

  12. Facile Synthesis of Core/Shell-like NiCo2O4-Decorated MWCNTs and its Excellent Electrocatalytic Activity for Methanol Oxidation

    Science.gov (United States)

    Ko, Tae-Hoon; Devarayan, Kesavan; Seo, Min-Kang; Kim, Hak-Yong; Kim, Byoung-Suhk

    2016-02-01

    The design and development of an economic and highly active non-precious electrocatalyst for methanol electrooxidation is challenging due to expensiveness of the precursors as well as processes and non-ecofriendliness. In this study, a facile preparation of core-shell-like NiCo2O4 decorated MWCNTs based on a dry synthesis technique was proposed. The synthesized NiCo2O4/MWCNTs were characterized by infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and selected area energy dispersive spectrum. The bimetal oxide nanoparticles with an average size of 6 ± 2 nm were homogeneously distributed onto the surface of the MWCNTs to form a core-shell-like nanostructure. The NiCo2O4/MWCNTs exhibited excellent electrocatalytic activity for the oxidation of methanol in an alkaline solution. The NiCo2O4/MWCNTs exhibited remarkably higher current density of 327 mA/cm2 and a lower onset potential of 0.128 V in 1.0 M KOH with as high as 5.0 M methanol. The impressive electrocatalytic activity of the NiCo2O4/MWCNTs is promising for development of direct methanol fuel cell based on non-Pt catalysts.

  13. SÍNTESIS Y CARACTERIZACIÓN DE CATALIZADORES Ni/MCM-22, Pt/MCM-22 Y Pt-Ni/MCM-22

    Directory of Open Access Journals (Sweden)

    Everton R.F. dos Santos

    2012-01-01

    Full Text Available El objetivo de este estudio fue producir la zeolita MCM-22 y, a partir de ésta, desarrollar catalizadores de zeolitas (Ni/MCM-22, Pt/MCM-22 y Pt-Ni/MCM-22. La obtención de estos catalizadores se realizó mediante el proceso de intercambio competitivo de iones. Estos materiales se caracterizaron por Difracción de Rayos X (DRX, Espectrometría de Energía Dispersiva (EDX, Termogravimétrico (TGA, y grado de adsorción de n-butilamina. La difracción de rayos X del precursor MCM-22 (P mostró los picos típicos de la topología MWW (Mobil tWenty tWo. En el patrón de difracción de la muestra calcinada no se observaron picos relacionados con la materia orgánica responsable por la producción de la zeolita MCM-22. Se verificó por termogravimetría, que la pérdida de masa en las muestras del catalizador se encuentra cercana a los 150 °C. La pérdida de masa total de los catalizadores muestra una reducción considerable en la cantidad de n-butilamina fisisorbida para el catalizador bimetálico.

  14. Green-chemistry Compatible Approach to TiO2-supported PdAu Bimetallic Nanoparticles for Solvent-free 1-Phenylethanol Oxidation under Mild Conditions

    Institute of Scientific and Technical Information of China (English)

    Jian-Bing Chang; Chang-Hai Liu; Jie Liu; Yu-Yan Zhou; Xu Gao; Sui-Dong Wang

    2015-01-01

    TiO2-supported PdAu bimetallic nanoparticles (NPs) with small size and good dispersity were prepared by the room-temperature ionic liquid-assisted bimetal sputtering, which is simple, environmentally friendly, and free of additives and byproducts. Pd/Au atomic ratio can be tuned by controlling the sputtering conditions simply. High catalytic activity was found in PdAu–NPs–TiO2 hybrids for solvent-free selective oxidation of 1-phenylethanol using O2 as the oxidant at the low temperature of 50 °C and low pressure of 1 atm. It was found that Pd/Au ratio strongly affected the catalytical activity, and the highest conversion of about 35%and turnover frequency of about 421 h-1 were achieved at 1:1 of Pd/Au atomic ratio. The synergistic effect in PdAu NPs was also discussed based on the comprehensive characterization results. The present approach may offer an alternative platform for future development of green-chemistry compatible bimetallic nanocatalysts.

  15. Characterisation of strip silicon 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...

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.)

  2. 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)

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. XPS and DFT study of pulsed Bi-implantation of bulk and thin-films of ZnO-The role of oxygen imperfections

    Science.gov (United States)

    Zatsepin, D. A.; Boukhvalov, D. W.; Gavrilov, N. V.; Kurmaev, E. Z.; Zhidkov, I. S.

    2016-11-01

    An atomic and electronic structure of the bulk and thin-film morphologies of ZnO were modified using pulsed Bi-ion implantation (1 × 1017 cm-2 fluence, 70 min exposure under Bi-ion beam, EBi+ = 30 keV, pulsed ion-current density of not more than 0.8 mA/cm2 with a repetition rate of 12.5 Hz). The final samples were qualified by X-ray photoelectron core-level and valence band mapping spectroscopy applying ASTM materials science standard. The spectroscopy data obtained was discussed on the basis of DFT-models for Bi-embedding into ZnO host-matrices. It was established that in the case of direct Bi-impurities insertion into the employed ZnO-host for both studied morphologies neither the only "pure" Bi2O3-like phase nor the only "pure" Bi-metal will be preferable to appear as a secondary phase. An unfavorability of the large cluster agglomeration of Bi-impurities in ZnO-hosts has been shown and an oxygen 2s electronic states pleomorphizm was surely established.

  8. 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.).

  9. 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

  10. 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.

  11. 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.

  12. Atomically Precise Colloidal Metal Nanoclusters and Nanoparticles: Fundamentals and Opportunities.

    Science.gov (United States)

    Jin, Rongchao; Zeng, Chenjie; Zhou, Meng; Chen, Yuxiang

    2016-09-28

    Colloidal nanoparticles are being intensely pursued in current nanoscience research. Nanochemists are often frustrated by the well-known fact that no two nanoparticles are the same, which precludes the deep understanding of many fundamental properties of colloidal nanoparticles in which the total structures (core plus surface) must be known. Therefore, controlling nanoparticles with atomic precision and solving their total structures have long been major dreams for nanochemists. Recently, these goals are partially fulfilled in the case of gold nanoparticles, at least in the ultrasmall size regime (1-3 nm in diameter, often called nanoclusters). This review summarizes the major progress in the field, including the principles that permit atomically precise synthesis, new types of atomic structures, and unique physical and chemical properties of atomically precise nanoparticles, as well as exciting opportunities for nanochemists to understand very fundamental science of colloidal nanoparticles (such as the stability, metal-ligand interfacial bonding, ligand assembly on particle surfaces, aesthetic structural patterns, periodicities, and emergence of the metallic state) and to develop a range of potential applications such as in catalysis, biomedicine, sensing, imaging, optics, and energy conversion. Although most of the research activity currently focuses on thiolate-protected gold nanoclusters, important progress has also been achieved in other ligand-protected gold, silver, and bimetal (or alloy) nanoclusters. All of these types of unique nanoparticles will bring unprecedented opportunities, not only in understanding the fundamental questions of nanoparticles but also in opening up new horizons for scientific studies of nanoparticles. PMID:27585252

  13. 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.

  14. 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.

  15. 铁铜双金属催化剂选择性催化氧化氨为氮气%Selective Catalytic Oxidation of Ammonia to Nitrogen over Iron and Copper Bimetallic Catalysts

    Institute of Scientific and Technical Information of China (English)

    孙萌萌; 曹毅; 兰丽; 邹莎; 房志涛; 陈耀强

    2014-01-01

    Iron and copper bimetal ic catalysts with fixed total contents of copper and iron were prepared by a co-impregnation method, and then used for selective catalytic oxidation of ammonia to nitrogen. The properties of the catalysts were characterized by N2 adsorption-desorption, H2 temperature-programmed reduction (H2-TPR), NH3 temperature-programmed desorption (NH3-TPD), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The iron and copper bimetal ic catalysts exhibited good activity and high selectivity of N2 at the gas hourly space velocity (GHSV) of 100000 h-1. The activity and N2 selectivity in the low temperature range increased with increasing Cu loading, whereas in the high temperature range (above 400 ° C) the selectivity of N2 was directly related to the content of iron. The highest NH3 conversion was achieved at about 350 °C for Fe0.25Cu0.75/ZSM-5, and the N2 selectivity was up to 97%at 300 °C. On the other hand, the extremely high N2 selectivity about 98%was obtained over Fe0.75Cu0.25/ZSM-5 at 500 °C. In addition, N2O as the by-product and greenhouse gas was obtained in very low amounts for al the catalysts. The characterization results showed that the activity was influenced by the acid content and the amounts of copper species. Moreover, the highly reducing capacity could improve the N2 selectivity.%固定铜铁的总质量不变,采用共浸渍法制备铜铁双金属催化剂.为了更好地了解催化剂的性质,分别用N2吸附-脱附、H2-程序升温还原(H2-TPR)、NH3-程序升温脱附(NH3-TPD)、X射线衍射(XRD)和X射线光电子能谱(XPS)方法对制备的催化剂进行表征.研究发现在100000 h-1空速下,铜铁双金属催化剂呈现出好的活性和氮气选择性.在低温区,随着铜含量的增加,活性和氮气的选择性增加,然而在高温区氮气的选择性直接和铁的含量相关.其中催化剂Fe0.25Cu0.75/ZSM-5,在350° C氨的转化率达到最高,在300° C

  16. The CMT-process and its possible applications, especially joining of steel with aluminium; Der CMT - Prozess und seine Moeglichkeiten, im speziellen das Fuegen von Stahl mit Aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Bruckner, J.; Himmelbauer, K.; Hackl, H. [Fronius International GmbH, Wels (Austria)

    2004-07-01

    Knowing how to weld dissimilar metals is becoming more and more important. One reason is that it's often impossible for one material to provide the optimum chemical, physical, and mechanical characteristics needed for an application. For this reason, as well as cost efficiency, technology specialists are experimenting with different joining processes to weld bimetal joints optimally. A reliable method of joining the two most commonly used metals, steel and aluminum, would make it possible to make these joints in several applications. On one hand, aluminum is becoming increasingly more important in the automotive industry because of its good processing and performance characteristics and because it's lightweight, which results in lower fuel consumption. Given today's heightened need to decrease energy consumption, aluminum is a major player in modern-day mechanical engineering. On the other hand, steel continues to dominate many fields of engineering, a fact underlined by the development of high-strength and superhigh-strength steels. When different metals are joined, each metal's features should be considered. It's important to pay attention to the chemical and physical properties-such as the corrosion behavior and thermal expansion coefficient-and to atomic properties, such as the lattice constant and type of crystalline lattice. Processes typically used to join dissimilar metals are bonding, riveting, or clinching, which essentially have no influence on the metals' atomic properties. Another method, thermal joining, can shorten joining time, produce tight seams, and provide high strength. (orig.)

  17. 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 KCk-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.

  18. 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.

  19. An investigation into friction stir welding of copper niobium nanolamellar composites

    Science.gov (United States)

    Cobb, Josef Benjamin

    The workpiece materials used in this study are CuNb nano-layered composites (NLC) which are produced in bulk form by accumulative roll bonding (ARB). CuNb NLC panels are of interest because of their increase in strength and radiation damage tolerance when compared to either of their bulk constituents. These increased properties stem from the bi-metal interface, and the nanometer length-scale of the layers. However to be commercially viable, methods to successfully join the ARB NLC which retain the layered structure panels are needed. Friction stir welding is investigated in this study as a possible joining method that can join the material while maintaining its layered structure and hence its properties. Mechanical properties of the weld were measured at a macro level using tensile testing, and at a local level via nano-indentation. The post weld layer structure was analyzed to provide insight into the flow paths. The grain orientation of the resulting weld nugget was also analyzed using electron backscatter diffraction and transmission Kikuchi diffraction. Results from this study show that the nano-layered structure can be maintained in the CuNb NLC by control of the friction stir welding parameters. The resulting microstructure is dependent on the strain experienced during the joining process. A variation in layer thickness reduction is correlated with increasing shear strain. Above a critical level of shear strain, the NLC microstructure was observed to fragment into equiaxed grains with a higher hardness than the NLC panels. Results from this study are also used to further the understanding of the material flow and hot working conditions experienced during the friction stir welding process.

  20. Using multi-layered roll bonding and reaction annealing to process gamma-titanium aluminide sheet material

    Science.gov (United States)

    Chaudhari, Gajanan Prabhakar

    The process of roll bonding and reaction annealing was used to process gamma-titanium aluminide sheets with a nearly fully lamellar microstructure. Cold roll bonding was employed to bond elemental Al and Ti foils. The bonded sheets were annealed at 600 °C to convert all of the Al into TiAl3. The effect of rolling strain on the reaction kinetics was studied. Accumulative roll bonding was also employed to study the effect of increased rolling strain on the microstructures resulting after annealing. After the first annealing stage, a cold rolling step resulted in a denser microstructure. A second annealing treatment at 1300 °C for 6 h resulted in a microstructure consisting of two phases, gamma and alpha2, along with Kirkendall porosity. Further densification of the sheets was carried out using hot rolling. A final heat treatment at 1400 °C for 0.3 h resulted in nearly fully lamellar microstructure. The porosity evolution was evaluated at different stages of processing. The mechanical properties of the processed sheet were determined and compared with the data available in the literature. The process of bi-metal multi-layer roll bonding was modeled using the equilibrium force balance method (slab method). The effect of anisotropy and strain hardening was included in the model. The effect of different variables such as total reduction, coefficient of friction, roll radius and initial foil thickness ratio, on the thickness fraction of metals in the bonded composite was investigated. The model enables the estimation of the final composition of the roll bonded composite. The results of the model were compared with the experimental results, and good agreement was observed.

  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. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Double metal rolling pipe used in air cooler in power plant%双金属轧片管在发电厂空冷器中的应用

    Institute of Scientific and Technical Information of China (English)

    邓佐力

    2013-01-01

    through the analysis and comparison on around the reed pipe and double metal rolling tube performance, selection of double metal rolling tube of reasonable design for transformation of around reed air cooler in power plant, to improve the heat transfer efficiency, reduce the flow resistance, save energy, improve the economic benefit. According to the transformation of the results and the practical application, the bimetal sheet tube air cooler in air cooling generator on various parameters are better than the original wound tube air cooler, meet the requirements. Proof of double metal rolling tube air cooler in the power plant has the good application value, it is worth popularization and application in other similar situations.%  通过对绕簧管和双金属轧片管的性能分析比较,选取双金属轧片管对发电厂中的绕簧管空冷器进行合理设计改造,使其提高传热效率、降低流动阻力,达到节能降耗、提高效益目的。根据改造的结果以及在实际应用中看,采用双金属轧片管空冷器在发电机的空气冷却上各项参数均优于原绕簧管空冷器,达到了要求。证明双金属轧片管空冷器在发电厂中有很好的应用价值,在其它类似的场合中也值得应用推广。

  7. 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.

  8. The limitations of applying zero-valent iron technology in contaminants sequestration and the corresponding countermeasures: the development in zero-valent iron technology in the last two decades (1994-2014).

    Science.gov (United States)

    Guan, Xiaohong; Sun, Yuankui; Qin, Hejie; Li, Jinxiang; Lo, Irene M C; He, Di; Dong, Haoran

    2015-05-15

    Over the past 20 years, zero-valent iron (ZVI) has been extensively applied for the remediation/treatment of groundwater and wastewater contaminated with various organic and inorganic pollutants. Based on the intrinsic properties of ZVI and the reactions that occur in the process of contaminants sequestration by ZVI, this review summarizes the limitations of ZVI technology and the countermeasures developed in the past two decades (1994-2014). The major limitations of ZVI include low reactivity due to its intrinsic passive layer, narrow working pH, reactivity loss with time due to the precipitation of metal hydroxides and metal carbonates, low selectivity for the target contaminant especially under oxic conditions, limited efficacy for treatment of some refractory contaminants and passivity of ZVI arising from certain contaminants. The countermeasures can be divided into seven categories: pretreatment of pristine ZVI to remove passive layer, fabrication of nano-sized ZVI to increase the surface area, synthesis of ZVI-based bimetals taking advantage of the catalytic ability of the noble metal, employing physical methods to enhance the performance of ZVI, coupling ZVI with other adsorptive materials and chemically enhanced ZVI technology, as well as methods to recover the reactivity of aged ZVI. The key to improving the rate of contaminants removal by ZVI and broadening the applicable pH range is to enhance ZVI corrosion and to enhance the mass transfer of the reactants including oxygen and H(+) to the ZVI surface. The characteristics of the ideal technology are proposed and the future research needs for ZVI technology are suggested accordingly.

  9. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Poley, Luise [DESY, Hamburg (Germany); Blue, Andrew; Bates, Richard [Glasgow Univ. (United Kingdom). SUPA School of Physics and Astronomy; and others

    2016-03-15

    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 1 x 10{sup 35} cm{sup -2}s{sup -1} after 10 years of operation. A consequence of this increased luminosity is the expected radiation damage at 3000 fb{sup -1}, requiring the tracking detectors to withstand hadron equivalences to over 1 x 10{sup 16} 1 MeV neutrons per cm{sup 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 μm FWHM 15 keV micro focused X-ray beam. The devices under test were a 320 μm thick silicon stereo (Barrel) ATLAS12 strip mini sensor wire bonded to a 130 nm CMOS binary readout chip (ABC130) and a 320 μm thick full size radial (Endcap) strip sensor - utilizing bi-metal readout layers - wire bonded to 250 nm CMOS binary readout chips (ABCN-25). Sub-strip resolution of the 74.5 μm strips was achieved for both detectors. Investigation of the p-stop diffusion layers between strips is shown in detail for the wire bond pad regions. Inter strip charge collection measurements indicate that the effective width of the strip on the silicon sensors is determined by p-stops regions between the strips rather than the strip pitch. The collected signal allowed for the identification of operating thresholds for both devices, making it possible to compare signal response between different versions of silicon strip detector modules.

  11. Environmental application of millimeter-scale sponge iron (s-Fe(0)) particles (II): the effect of surface copper.

    Science.gov (United States)

    Ju, Yongming; Liu, Xiaowen; Liu, Runlong; Li, Guohua; Wang, Xiaoyan; Yang, Yanyan; Wei, Dongyang; Fang, Jiande; Dionysiou, Dionysios D

    2015-04-28

    To enhance the catalytic reactivity of millimeter-scale particles of sponge iron (s-Fe(0)), Cu(2+) ions were deposited on the surface of s-Fe(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(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(0) particles (s-Fe(0)(3∼5mm)) with 5wt% Cu loading gave the best results. The removal of RhB followed two-step, pseudo-first-order reaction kinetics. Cu(0)-s-Fe(0) showed excellent stability after five reuse cycles. Cu(0)-s-Fe(0) possesses great advantages compared to nanoscale zero-valent iron, iron power, and iron flakes as well as its bimetals. The surface Cu(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, Fe2O3 and Fe3O4 played minor role for the removal of RhB.

  12. Blindagem eletromagnética, aterramento e proteção contra surtos de tensão em equipamentos para monitoramento automático do teor de água no solo Electromagnetic shielding, grounding and protection against voltage surges in equipments for automatic soil-water measurements

    Directory of Open Access Journals (Sweden)

    Claudia F. A. Teixeira

    2004-04-01

    Full Text Available O objetivo do presente trabalho foi implementar um sistema de blindagem eletromagnética, aterramento e proteção contra surtos de tensão na instalação de instrumental para o monitoramento automático do teor de água no solo. O experimento foi instalado em Piracicaba, São Paulo, em que os equipamentos utilizados foram um testador de cabos marca Tektronix, que opera pelo princípio da reflectometria no domínio do tempo e um sistema de aquisição de dados marca Campbell Scientific Inc. (CSI, que controla e analisa as formas de onda produzidas pelo testador de cabos. A umidade volumétrica foi obtida indiretamente por meio de sensores inseridos no solo, os quais medem a constante dielétrica do mesmo. Utilizaram-se tubos galvanizados para a blindagem eletromagnética dos cabos e hastes "cooperweld", cordoalha de cobre e terminais bimetálicos para o sistema de aterramento. Para o sistema de proteção eletroeletrônica, utilizaram-se um disjuntor para a separação do circuito de alimentação, protetor de surtos, "no-breaks" e medidor de resistência de terra. Face aos resultados obtidos, pode-se concluir que o sistema proposto, ao utilizar material geralmente preexistente em locais de pesquisa agropecuária, apresentou uma proteção eficaz.The objective of this paper was to implement an electromagnetic shielding, grounding and voltage surge protection in equipments for automatic soil water monitoring. The experiment was carried out in Piracicaba, São Paulo State, Brazil, using a Tektronix Cable Tester (Model 1502 B that operates by time domain reflectometry (TDR and a datalogger (CR10X, Campbell Scientific Inc., CSI to control and analyze the waveforms produced by the cable tester. The water content was indirectly obtained by measuring the dielectric constant through probes inserted in the soil. For electromagnetic shielding the energy and signal cables were inserted in galvanized pipes, linked together by means of copper wire fixed in

  13. Ánodos de Pt-Ru y Pt-Ir para Celdas de Combustible Alimentadas con Metano y Propano Directo Pt-Ru and Pt-Ir Anodes for Direct Methane and Propane Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Bibian A Hoyos

    2007-01-01

    Full Text Available En este trabajo se evalúa el efecto de la temperatura en el desempeño de celdas de combustible de membrana de intercambio protónico alimentadas con metano y propano, utilizando oxígeno como alimentación en el cátodo. Para la oxidación de los combustibles en los ánodos, se probaron cinco catalizadores soportados en carbón: Pt, Pt85Ru15, Pt50Ru50, Pt90Ir10 y Pt50Ir50. Como catalizador en el cátodo se usó platino puro soportado en carbón. El desempeño de las celdas de combustible fue evaluado mediante curvas de polarización obtenidas a partir de los datos corriente-potencial. Los resultados indican que la oxidación de metano se ve favorecida a altas temperaturas sobre los catalizadores Pt90/Ir10, Pt50/Ir50 y Pt50/Ru50. A bajas temperaturas los mejores catalizadores resultaron ser Pt y Pt85/Ru15. La mezcla bimetálica Pt85/Ru15 fue la que presentó mejor desempeño para llevar a cabo la oxidación de propano a 30 °C.In this paper, the effect of temperature in the performance of proton exchange membrane fuel cells feed with methane and propane, using oxygen as feed to the cathode, is presented. For the fuel oxidation in the anodes, five carbon supported catalysts were tested: Pt, Pt85/Ru15, Pt50/Ru50, Pt90/Ir10, and Pt50/Ir50. Carbon-supported pure platinum was used as catalysts in the cathode side. The performance of the fuel cells was evaluated by polarization curves obtained from the current-potential data. Results indicate that methane oxidation is favoured at high temperatures on the Pt90/Ir10, Pt50/Ir50 and Pt50/Ru50 catalysts. At low temperatures the best catalysts were Pt and Pt85/Ru15. The Pt85/Ru15 bimetallic mixture showed the best performance to carry out propane oxidation at 30 °C.

  14. 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

  15. 固体酸WO3/TiO2的制备及其催化合成正丁酸己酯%Preparation of WO3/TiO2 solid acid and synthesis of hexyl butyrate

    Institute of Scientific and Technical Information of China (English)

    曹永军

    2011-01-01

    A new bimetal solid acid catalyst WO3/TiO2 was synthesized with WO3 as active component. Hexyl butyrate was synthesized from butyric acid with n-hexanol as the catalyst. The effects of various factors such as WO3 content,calcination temperature of the catalyst,catalyst dosage,molar ratio of n-hexanol to butyric acid and reaction time on esterification rate were investigated. The results indicated that suitable conditions of the catalyst obtained were :WO3 50% ,calcination at 500 ℃ for 2. 0 h. The optimized conditions of synthesizing hexyl butyrate were: molar ratio of n-hexanol to butyric acid 2. 0,reaction time 90 min, cyclohexane 10 mL and catalyst dosage 2. 0 g,esterification rate was 98.8% . The catalyst also had exceUent stability. After the catalyst was used for 5 times,the esterification rate could still reach 87. 6% all the same.%制备了WO3为活性组分、TiO2为载体的双金属固体酸酯化催化剂WO3/TiO2,用于正丁酸与正己醇酯化合成正丁酸己酯,考察了催化剂中WO3含量、焙烧温度、催化剂用量、n(正己醇):n(正丁酸)、反应时间和催化剂重复使用性等因素对酯化率的影响.实验结果表明,催化剂的适宜制备条件是WO3 50%、500℃焙烧2.0 h.催化合成正丁酸已酯的适宜反应条件为:n(正己醇):n(正丁酸)=2.0,催化剂用量2.0 g,环己烷10 mL,反应时间90min.在此条件下,酯化率为98.8%,催化剂使用5次后,酯化率仍可达87.6%.

  16. 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

  17. 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.

  18. 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.

  19. El efecto de la heterogeneidad de las propiedades mecánicas de una unión soldada sobre la carga de plastificación de probetas de fractura tipo C(T Y SE(B

    Directory of Open Access Journals (Sweden)

    Donoso, J. R.

    2008-10-01

    Full Text Available The yield load values of two-dimensional C(T and SE(B specimens with various degrees of mismatch, were numerically evaluated. The yield load values were normalized using the Common Format in order to analyze the effect of the weld, using as reference material C(T and SE(B specimens made only of base metal (BM. In undermatched specimens (the weld metal elastic limit is lower than that of BM the normalized yield load decreases compared to the elastic limit of BM. In overmatched specimens (the weld metal elastic limit is larger than that of BM, the yield load increases. This variation of the yield load depends on the degree of mismatch, and on the relation between weld size and crack length. The numerical results were compared with experimental values obtained with mismatched weld C(T specimens using an ASTM A 588 steel as base metal.

    Se determinaron, numéricamente, los valores de la carga de plastificación de probetas de geometría compacta C(T y de flexión SE(B, bidimensionales, con cordón de soldadura de diferentes grados de desajuste entre los límites elásticos del material de soldadura y del metal base. Los valores de la carga de plastificación de las probetas bimetálicas se normalizaron mediante el Formato Común, con el objeto de analizar el efecto del cordón, tomando como referencia probetas de metal base (MB. En probetas sub-ajustadas (límite elástico del cordón menor que el de MB la carga de plastificación normalizada disminuye, comparada con el límite elástico de MB. En probetas sobre-ajustadas (límite elástico del cordón mayor que el de MB se produce un aumento de la carga de plastificación normalizada. Esta variación depende del grado de desajuste, y de la relación entre tamaño de cordón y longitud de grieta. Los resultados numéricos se compararon con valores experimentales obtenidos con probetas C(T de uniones soldadas desajustadas del acero ASTM A 588.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. Metallography of Battery Resistance Spot Welds

    Science.gov (United States)

    Martinez, J. E.; Johannes, L. B.; Gonzalez, D.; Yayathi, S.; Figuered, J. M.; Darcy, E. C.; Bilc, Z. M.

    2015-01-01

    Li-ion cells provide an energy dense solution for systems that require rechargeable electrical power. However, these cells can undergo thermal runaway, the point at which the cell becomes thermally unstable and results in hot gas, flame, electrolyte leakage, and in some cases explosion. The heat and fire associated with this type of event is generally violent and can subsequently cause damage to the surrounding system or present a dangerous risk to the personnel nearby. The space flight environment is especially sensitive to risks particularly when it involves potential for fire within the habitable volume of the International Space Station (ISS). In larger battery packs such as Robonaut 2 (R2), numerous Li-ion cells are placed in parallel-series configurations to obtain the required stack voltage and desired run-time or to meet specific power requirements. This raises a second and less obvious concern for batteries that undergo certification for space flight use: the joining quality at the resistance spot weld of battery cells to component wires/leads and battery tabs, bus bars or other electronic components and assemblies. Resistance spot welds undergo materials evaluation, visual inspection, conductivity (resistivity) testing, destructive peel testing, and metallurgical examination in accordance with applicable NASA Process Specifications. Welded components are cross-sectioned to ensure they are free of cracks or voids open to any exterior surface. Pore and voids contained within the weld zone but not open to an exterior surface, and are not determined to have sharp notch like characteristics, shall be acceptable. Depending on requirements, some battery cells are constructed of aluminum canisters while others are constructed of steel. Process specific weld schedules must be developed and certified for each possible joining combination. The aluminum canisters' positive terminals were particularly difficult to weld due to a bi-metal strip that comes ultrasonically

  6. 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