WorldWideScience

Sample records for palladium excess heat

  1. Progress in excess of power experiments with electrochemical loading of deuterium in palladium

    International Nuclear Information System (INIS)

    Violante, V.; Moretti, S.; Bertolotti, M.

    2006-01-01

    A research activity has been carried out, during the last 3 years, in the field of triggering anomalous heat effects in palladium deuteride. An enhancement of the excess of power reproducibility in deuterated palladium was obtained by using He-Ne Laser irradiation during electrochemical loading. A preliminary correlation between excess of energy and 4 He concentration increasing above the background was found. The continuation of the experimental program confirmed that Laser triggering produce an interesting gain of reproducibility. An upgrade of the experimental set-up has been realized. (author)

  2. The abundant excess heat production during low energy nuclear reaction in the nano scale solid state the cold fusion, 14 years' legacy

    International Nuclear Information System (INIS)

    Woo, Tae Ho; Miley, George H.; Lipson, Andrei; Kim, Sung O.; Luo, Nie; Castano, Carlos H.

    2002-01-01

    The quite abundant excess heat and radioactive materials are found during the solid state reaction. This phenomenon has done during the Low Energy Nuclear Reaction (LENR) in the nano scale molecular structure electrodes and Hydrogen compound electrolytes. The Palladium (or Nickel) and Platinum are incorporated as the electrode and the Light Water (H 2 O) as the electrolyte. The excess heat was produced up to 40% in year 2001. The Alpha particles are also detected. The computer code, Coherent Lattice Accelerator Inter-Ionic Reaction Enhancer (CLAIRE) Code System, is constructed for the simulation. The 0.1 A of the distance between two the Hydrogen ion (proton) and Palladium nucleus is the critical point for the nuclear fusion reaction

  3. The abundant excess heat production during low energy nuclear reaction in the nano scale solid state the cold fusion, 14 years' legacy

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Tae Ho; Miley, George H.; Lipson, Andrei; Kim, Sung O.; Luo, Nie; Castano, Carlos H. [The University of Illinois, Urbana (United States)

    2002-05-01

    The quite abundant excess heat and radioactive materials are found during the solid state reaction. This phenomenon has done during the Low Energy Nuclear Reaction (LENR) in the nano scale molecular structure electrodes and Hydrogen compound electrolytes. The Palladium (or Nickel) and Platinum are incorporated as the electrode and the Light Water (H{sub 2}O) as the electrolyte. The excess heat was produced up to 40% in year 2001. The Alpha particles are also detected. The computer code, Coherent Lattice Accelerator Inter-Ionic Reaction Enhancer (CLAIRE) Code System, is constructed for the simulation. The 0.1 A of the distance between two the Hydrogen ion (proton) and Palladium nucleus is the critical point for the nuclear fusion reaction.

  4. Heat evolution involved with electrochemical discharge of hydrogen and deuterium onto palladium

    International Nuclear Information System (INIS)

    Chemla, M.; Chevalet, J.; Bury, R.

    1989-01-01

    Using a quasi-adiabatic micro-calorimeter, we could determine the thermal energy generated during electrolysis of a 0.2 M solution of LiO D in heavy water. In all cases of usual electrolysis, the heat production was found to be less than the total input of electrical energy. We also applied a new technique of transfer electrolysis, where a sample of deuterium saturated palladium was used as the anode. Then, the thermal energy is strictly equal to the consumed electrical energy. In a few experiments, a slight excess of enthalpy was observed and was assumed to result from partial oxidation of deuterium by trace amounts of oxygen. Similar experiments using natural water lead to comparable results [fr

  5. Industrial excess heat for district heating in Denmark

    International Nuclear Information System (INIS)

    Bühler, Fabian; Petrović, Stefan; Karlsson, Kenneth; Elmegaard, Brian

    2017-01-01

    Highlights: •Method for utilisation potential of industrial excess heat for district heating. •Industrial excess heat from thermal processes is quantified at single production units. •Linking of industrial excess heat sources and district heating demands done in GIS. •Excess heat recovery using direct heat transfer and heat pumps. •5.1% of the Danish district heating demand could be supplied by industrial excess heat. -- Abstract: Excess heat is available from various sources and its utilisation could reduce the primary energy use. The accessibility of this heat is however dependent amongst others on the source and sink temperature, amount and potential users in its vicinity. In this work a new method is developed which analyses excess heat sources from the industrial sector and how they could be used for district heating. This method first allocates excess heat to single production units by introducing and validating a new approach. Spatial analysis of the heat sources and consumers are then performed to evaluate the potential for using them for district heating. In this way the theoretical potential of using the excess heat for covering the heating demand of buildings is determined. Through the use of industry specific temperature profiles the heat usable directly or via heat pumps is further found. A sensitivity analysis investigates the impact of future energy efficiency measures in the industry, buildings and the district heating grid on the national potential. The results show that for the case study of Denmark, 1.36 TWh of district heat could be provided annually with industrial excess heat from thermal processes which equals 5.1% of the current demand. More than half of this heat was found to be usable directly, without the need for a heat pump.

  6. Evaluation of Excess Heat Utilization in District Heating Systems by Implementing Levelized Cost of Excess Heat

    Directory of Open Access Journals (Sweden)

    Borna Doračić

    2018-03-01

    Full Text Available District heating plays a key role in achieving high primary energy savings and the reduction of the overall environmental impact of the energy sector. This was recently recognized by the European Commission, which emphasizes the importance of these systems, especially when integrated with renewable energy sources, like solar, biomass, geothermal, etc. On the other hand, high amounts of heat are currently being wasted in the industry sector, which causes low energy efficiency of these processes. This excess heat can be utilized and transported to the final customer by a distribution network. The main goal of this research was to calculate the potential for excess heat utilization in district heating systems by implementing the levelized cost of excess heat method. Additionally, this paper proves the economic and environmental benefits of switching from individual heating solutions to a district heating system. This was done by using the QGIS software. The variation of different relevant parameters was taken into account in the sensitivity analysis. Therefore, the final result was the determination of the maximum potential distance of the excess heat source from the demand, for different available heat supplies, costs of pipes, and excess heat prices.

  7. Basic study of cold fusion. 1. The development of excess heat measurement system in electrolysis

    International Nuclear Information System (INIS)

    Asaoka, Yoshiyuki; Fujita, Tomonari

    1994-01-01

    We have an opportunity ripe to investigate the cold fusion phenomena. In order to declare the subjects to be examined, the precision calorimetry system was developed to try to reproduce the phenomena. The electrolysis of heavy water with palladium cathode was conducted based on the thought that it is important to confirm the cold fusion phenomena. For precision excess power measurement, the closed cell with recombiner and flow-calorimetry were adopted. The obtained accuracy for the excess power measurement of the system was ±0.2 W at up to 9 W of applied power. This is enough for the excess power reported as the cold fusion phenomena. For farther investigation, measurement of loading ratio of deuterium in the palladium cathode, maintenance of high deuterium loading and analysis of the palladium cathode are to be conducted. (author)

  8. Industrial excess heat for district heating in Denmark

    DEFF Research Database (Denmark)

    Bühler, Fabian; Petrovic, Stefan; Karlsson, Kenneth Bernard

    2017-01-01

    analyses excess heat sources from the industrial sector and how they could be used for district heating. This method first allocates excess heat to single production units by introducing and validating a new approach. Spatial analysis of the heat sources and consumers are then performed to evaluate...... the potential for using them for district heating. In this way the theoretical potential of using the excess heat for covering the heating demand of buildings is determined. Through the use of industry specific temperature profiles the heat usable directly or via heat pumps is further found. A sensitivity...... analysis investigates the impact of future energy efficiency measures in the industry, buildings and the district heating grid on the national potential. The results show that for the case study of Denmark, 1.36 TWh of district heat could be provided annually with industrial excess heat from thermal...

  9. Investigation of high temperature reactions on solid substrates with Rutherford backscattering spectrometry: interaction of palladium with selenium on heated graphite surfaces

    International Nuclear Information System (INIS)

    Majidi, V.; Robertson, J.D.

    1991-01-01

    Selenium and palladium interactions on heated pyrolytically coated graphite substrates were investigated using Rutherford backscattering spectrometry. The studies were performed using selenium alone, palladium alone, and a combination of selenium and palladium deposited on the graphite substrates. The results indicate that palladium instantaneously stabilizes selenium at ambient temperatures and prevents the diffusion of selenium into the graphite. As the substrate is heated, temperature dependent diffusion of all analytes into the graphite is observed. Furthermore, it appears that the stabilization of selenium is due to the formation of a stoichiometric compound with palladium and oxygen. This compound decomposes at a temperature between 1070 and 1770 K. (author)

  10. Investigation of high temperature reactions on solid substrates with Rutherford backscattering spectrometry: interaction of palladium with selenium on heated graphite surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Majidi, V.; Robertson, J.D. (Kentucky Univ., Lexington, KY (United States). Dept. of Chemistry)

    1991-01-01

    Selenium and palladium interactions on heated pyrolytically coated graphite substrates were investigated using Rutherford backscattering spectrometry. The studies were performed using selenium alone, palladium alone, and a combination of selenium and palladium deposited on the graphite substrates. The results indicate that palladium instantaneously stabilizes selenium at ambient temperatures and prevents the diffusion of selenium into the graphite. As the substrate is heated, temperature dependent diffusion of all analytes into the graphite is observed. Furthermore, it appears that the stabilization of selenium is due to the formation of a stoichiometric compound with palladium and oxygen. This compound decomposes at a temperature between 1070 and 1770 K. (author).

  11. Low-cost method for fabricating palladium and palladium-alloy thin films on porous supports

    Science.gov (United States)

    Lee, Tae H; Park, Chan Young; Lu, Yunxiang; Dorris, Stephen E; Balachandran, Uthamalingham

    2013-11-19

    A process for forming a palladium or palladium alloy membrane on a ceramic surface by forming a pre-colloid mixture comprising a powder palladium source, carrier fluid, dispersant and a pore former and a binder. Ultrasonically agitating the precolloid mixture and applying to a substrate with an ultrasonic nozzle and heat curing the coating form a palladium-based membrane.

  12. Recovery of palladium, cesium, and selenium from heavy metal alkali borosilicate glass by combination of heat treatment and leaching processes

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhanglian; Okada, Takashi, E-mail: t-okada@u-fukui.ac.jp; Nishimura, Fumihiro; Yonezawa, Susumu

    2017-06-05

    Highlights: • A separation technique of both noble and less noble metal from glass is studied. • Via reductive heat treatment, 80% of palladium is extracted in liquid bismuth. • Sodium–potassium-rich materials with cesium and selenium are phase separated. • From the materials, over 80% of cesium and selenium are extracted in water. - Abstract: Reductive heat-treatment and leaching process were applied to a simulated lead or bismuth soda-potash-borosilicate glass with palladium, cesium, and selenium to separate these elements. In the reductive heat treatment, palladium is extracted in liquid heavy metal phase generated by the reduction of the heavy metal oxides, whereas cesium and selenium are concentrated in phase separated Na–K-rich materials on the glass surface. From the materials, cesium and selenium can be extracted in water, and the selenium extraction was higher in the treatment of the bismuth containing glass. The chemical forms of palladium in the glass affected the extraction efficiencies of cesium and selenium. Among the examined conditions, in the bismuth glass treatment, the cesium and selenium extraction efficiencies in water were over 80%, and that of palladium in liquid bismuth was over 80%.

  13. Excess Sodium Tetraphenylborate and Intermediates Decomposition Studies

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, M.J.

    1998-12-07

    The stability of excess amounts of sodium tetraphenylborate (NaTPB) in the In-Tank Precipitation (ITP) facility depends on a number of variables. Concentration of palladium, initial benzene, and sodium ion as well as temperature provide the best opportunities for controlling the decomposition rate. This study examined the influence of these four variable on the reactivity of palladium-catalyzed sodium tetraphenylborate decomposition. Also, single effects tests investigated the reactivity of simulants with continuous stirring and nitrogen ventilation, with very high benzene concentrations, under washed sodium concentrations, with very high palladium concentrations, and with minimal quantities of excess NaTPB.

  14. Member for conducting excess heat away from heat sources

    International Nuclear Information System (INIS)

    Cooke-Yarborough, E.H.

    1975-01-01

    Should a radioisotope-powered engine (e.g., a Stirling cycle engine for generating electricity) stop working for any reason, the radioisotope heat source will continue to generate heat. This will result in a rise in temperature which may cause overheating of and possible damage to the engine as well as to the heat source itself. The invention provides a support/location member for conducting excess heat from the heat source and which, in normal operation of the engine, will impede the conduction of heat away from the heat source and so reduce thermal losses. The member is of elongated form and comprises a stack of heat-conductive slugs disposed in a tube and in interspaced relationship along the axis of the tube. The tube supports the slugs in axial alignment. Means are provided for attaching an end one of the slugs to the heat source and means operable on overheating of said end one of the slugs are also provided whereby the slugs are able to move into heat-conducting contact with each other so as to conduct the excess heat away from said heat source. The slugs may be brazed to the tube whereby progressive overheating of the slugs along the stack results in an overheated slug being freed from attachment to the tube so as to allow the overheated slug to move along the stack and engage the next slug in line in heat-conducting contact. (U.S.)

  15. Characterising palladium-silver and palladium-nickel alloy membranes using SEM, XRD and PIXE

    International Nuclear Information System (INIS)

    Keuler, J.N.; Lorenzen, L.; Sanderson, R.D.; Prozesky, V.; Przybylowicz, W.J.

    1999-01-01

    Palladium alloy membranes were prepared by successive electroless plating steps on an alumina-zirconia support membrane. Palladium, silver and nickel were deposited in layers and then the metal films were heat treated for 5 h in a hydrogen atmosphere at 650 deg. C. The topography of the metal coatings and cross-sections of the films (before and after heating) were characterised using scanning electron microscopy (SEM). XRD was used to determine the crystal phase of the alloy coatings. Both SEM and XRD provide only surface information and therefore micro-PIXE was used to extract depth information of the alloy coating. Concentration profiles across the thickness of the films were constructed to determine penetration of the coating into the support membrane pores during electroless plating and to investigate diffusion of coated layers during the heating step

  16. Identification and Evaluation of Cases for Excess Heat Utilisation Using GIS

    Directory of Open Access Journals (Sweden)

    Fabian Bühler

    2018-03-01

    Full Text Available Excess heat is present in many sectors, and its utilization could reduce the primary energy use and emission of greenhouse gases. This work presents a geographical mapping of excess heat, in which excess heat from the industry and utility sector was distributed to specific geographical locations in Denmark. Based on this mapping, a systematic approach for identifying cases for the utilization of excess heat is proposed, considering the production of district heat and process heat, as well as power generation. The technical and economic feasibility of this approach was evaluated for six cases. Special focus was placed on the challenges for the connection of excess heat sources to heat users. To account for uncertainties in the model input, different methods were applied to determine the uncertainty of the results and the most important model parameters. The results show how the spatial mapping of excess heat sources can be used to identify their utilization potentials. The identified case studies show that it can be economically feasible to connect the heat sources to the public energy network or to use the heat to generate electricity. The uncertainty analysis suggests that the results are indicative and are particularly useful for a fast evaluation, comparison and prioritization of possible matches. The excess heat temperature and obtainable energy price were identified as the most important input parameters.

  17. Spatiotemporal and economic analysis of industrial excess heat as a resource for district heating

    DEFF Research Database (Denmark)

    Bühler, Fabian; Petrović, Stefan; Holm, Fridolin Müller

    2018-01-01

    detailed analysis of the most suitable types of industries and the costs is required, allowing a targeted exploitation of this resource. This work extends the spatial and thermodynamic analysis, to account for the temporal match between industrial excess heat and district heating demands, as well...... as the costs for implementation and operation of the systems. This allows the determination of cost-effective district heating potentials, as well as the analysis of different industries and technological requirements. The results show that the temporal mismatch between excess heat and district heating demand...... and lack of demand, reduces the theoretical substitution potential by almost 30%. If heat storages are introduced, the total potential is reduced by only 10%. A majority of the excess heat can be utilised at socio-economic heating costs lower than the average Danish district heating price and the cost...

  18. Excess Sodium Tetraphenylborate and Intermediates Decomposition Studies

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, M.J. [Westinghouse Savannah River Company, AIKEN, SC (United States); Peterson , R.A.

    1998-04-01

    The stability of excess amounts of sodium tetraphenylborate (NaTPB) in the In-Tank Precipitation (ITP) facility depends on a number of variables. Concentration of palladium, initial benzene, and sodium ion as well as temperature provide the best opportunities for controlling the decomposition rate. This study examined the influence of these four variables on the reactivity of palladium-catalyzed sodium tetraphenylborate decomposition. Also, single effects tests investigated the reactivity of simulants with continuous stirring and nitrogen ventilation, with very high benzene concentrations, under washed sodium concentrations, with very high palladium concentrations, and with minimal quantities of excess NaTPB. These tests showed the following.The testing demonstrates that current facility configuration does not provide assured safety of operations relative to the hazards of benzene (in particular to maintain the tank headspace below 60 percent of the lower flammability limit (lfl) for benzene generation rates of greater than 7 mg/(L.h)) from possible accelerated reaction of excess NaTPB. Current maximal operating temperatures of 40 degrees C and the lack of protection against palladium entering Tank 48H provide insufficient protection against the onset of the reaction. Similarly, control of the amount of excess NaTPB, purification of the organic, or limiting the benzene content of the slurry (via stirring) and ionic strength of the waste mixture prove inadequate to assure safe operation.

  19. Excess Sodium Tetraphenylborate and Intermediates Decomposition Studies

    International Nuclear Information System (INIS)

    Barnes, M.J.; Peterson, R.A.

    1998-04-01

    The stability of excess amounts of sodium tetraphenylborate (NaTPB) in the In-Tank Precipitation (ITP) facility depends on a number of variables. Concentration of palladium, initial benzene, and sodium ion as well as temperature provide the best opportunities for controlling the decomposition rate. This study examined the influence of these four variables on the reactivity of palladium-catalyzed sodium tetraphenylborate decomposition. Also, single effects tests investigated the reactivity of simulants with continuous stirring and nitrogen ventilation, with very high benzene concentrations, under washed sodium concentrations, with very high palladium concentrations, and with minimal quantities of excess NaTPB. These tests showed the following.The testing demonstrates that current facility configuration does not provide assured safety of operations relative to the hazards of benzene (in particular to maintain the tank headspace below 60 percent of the lower flammability limit (lfl) for benzene generation rates of greater than 7 mg/(L.h)) from possible accelerated reaction of excess NaTPB. Current maximal operating temperatures of 40 degrees C and the lack of protection against palladium entering Tank 48H provide insufficient protection against the onset of the reaction. Similarly, control of the amount of excess NaTPB, purification of the organic, or limiting the benzene content of the slurry (via stirring) and ionic strength of the waste mixture prove inadequate to assure safe operation

  20. Identification and Evaluation of Cases for Excess Heat Utilisation Using GIS

    DEFF Research Database (Denmark)

    Bühler, Fabian; Petrovic, Stefan; Ommen, Torben Schmidt

    2018-01-01

    Excess heat is present in many sectors, and its utilization could reduce the primary energy use and emission of greenhouse gases. This work presents a geographical mapping of excess heat, in which excess heat from the industry and utility sector was distributed to specific geographical locations...

  1. Economic analysis of using excess renewable electricity to displace heating fuels

    DEFF Research Database (Denmark)

    Pensini, Alessandro; Rasmussen, Claus Nygaard; Kempton, Willett

    2014-01-01

    . Because excess electricity appears to be cost-optimum, this raises the question as to whether the excess electricity, which in the case of wind power is predominately produced in colder weather, might displace other fuels for purposes such as heat. This study models using excess electricity for heating......, based on an analysis of electricity and heat use in a TSO in the North-Eastern part of the United States (PJM Interconnection). The heating system was modeled as heat pump based district heating (HPDH) with thermal energy storage (TES). Thus, excess electricity is transformed into heat, which is easy....... An algorithm that calculates the total cost of a unit of heat was used to determine the economically optimal size of the system’s main components and the influence that natural gas (NG) and electricity prices have on this optimum. It was found that a system based on heat pumps (HP) and centralized thermal...

  2. Modeling of hydrogen/deuterium dynamics and heat generation on palladium nanoparticles for hydrogen storage and solid-state nuclear fusion.

    Science.gov (United States)

    Tanabe, Katsuaki

    2016-01-01

    We modeled the dynamics of hydrogen and deuterium adsorbed on palladium nanoparticles including the heat generation induced by the chemical adsorption and desorption, as well as palladium-catalyzed reactions. Our calculations based on the proposed model reproduce the experimental time-evolution of pressure and temperature with a single set of fitting parameters for hydrogen and deuterium injection. The model we generated with a highly generalized set of formulations can be applied for any combination of a gas species and a catalytic adsorbent/absorbent. Our model can be used as a basis for future research into hydrogen storage and solid-state nuclear fusion technologies.

  3. Artificial crystals with 3d metal and palladium particles subjected to high-temperature heat treatment

    Science.gov (United States)

    Rinkevich, A. B.; Nemytova, O. V.; Perov, D. V.; Samoylovich, M. I.; Kuznetsov, E. A.

    2018-04-01

    High-temperature heat treatment has valuable impact on the structure and physical properties of artificial crystals with 3d metal and palladium particles. Artificial crystals are obtained by means of introduction of particles into the interspherical voids of opal matrices. The magnetic properties are studied at the temperatures ranging from 2 to 300 K and in fields up to 350 kOe. Microwave properties are investigated in the millimeter frequency range. The complex dielectric permittivity of several nanocomposites is measured. The influence of heat treatment up to 960 °C on the structure of artificial crystals is clarified.

  4. Changes in Blood Components in Aphtha Patients with Excess Heat

    OpenAIRE

    Qin, Lu; Li, Yan; Jiao, Yifeng; Fu, Danqing; Ye, Li; Ji, Jinjun; Xie, Guanqun; Fan, Yongsheng; Xu, Li

    2016-01-01

    “Superior heat” is a popularization expression in TCM heat syndrome and has no counterpart in the modern medical system concept. Oral ulcer is considered to be a kind of clinical manifestation of “superior heat.” Aphtha is a common and frequently occurring disease, which can be divided into excess heat and Yin deficiency. The aphtha of excess heat manifests the syndromes of acute occurrence, severe local symptoms, obvious swelling and pain, red tongue, yellow coating, and fast-powerful pulse....

  5. Abnormal excess heat observed during Mizuno-type experiments

    International Nuclear Information System (INIS)

    Fauvarque, Jean-Francois; Clauzon, Pierre Paul; Lalleve, Gerard Jean-Michel

    2006-01-01

    A simple calorimeter has been designed that works at constant temperature; that of boiling water. Heat Losses can be estimated accurately with an ohmic heater. As expected, losses are independent of the electric power input to the heater and the amount of evaporated water is linearly dependant on the power input. The device has been used to determine the heating power of a plasma electrolysis (the Ohmori-Mizuno experiment). We confirm that in this experiment, the heat output from electrolysis is greater than the electrical power input. The excess energy increases as the electrolysis voltage is increased from 200 up to 350 V (400 V input). The excess energy may be as high as 120 W. (author)

  6. Modeling of hydrogen/deuterium dynamics and heat generation on palladium nanoparticles for hydrogen storage and solid-state nuclear fusion

    Directory of Open Access Journals (Sweden)

    Katsuaki Tanabe

    2016-01-01

    Full Text Available We modeled the dynamics of hydrogen and deuterium adsorbed on palladium nanoparticles including the heat generation induced by the chemical adsorption and desorption, as well as palladium-catalyzed reactions. Our calculations based on the proposed model reproduce the experimental time-evolution of pressure and temperature with a single set of fitting parameters for hydrogen and deuterium injection. The model we generated with a highly generalized set of formulations can be applied for any combination of a gas species and a catalytic adsorbent/absorbent. Our model can be used as a basis for future research into hydrogen storage and solid-state nuclear fusion technologies.

  7. Conventional physics can explain cold fusion excess heat

    Science.gov (United States)

    Chubb, S. R.

    In 1989, when Fleischmann, Pons and Hawkins (FP), claimed they had created room temperature, nuclear fusion in a solid, a firestorm of controversy erupted. Beginning in 1991, the Office of Naval Research began a decade-long study of the FP excess heat effect. This effort documented the fact that the excess heat that FP observed is the result of a form of nuclear fusion that can occur in solids at reduced temperature, dynamically, through a deuteron (d)+d□4He reaction, without high-energy particles or □ rays. A key reason this fact has not been accepted is the lack of a cogent argument, based on fundamental physical ideas, justifying it. In the paper, this question is re-examined, based on a generalization of conventional energy band theory that applies to finite, periodic solids, in which d's are allowed to occupy wave-like, ion band states, similar to the kinds of states that electrons occupy in ordinary metals. Prior to being experimentally observed, the Ion Band State Theory (IBST) of cold fusion predicted a potential d+d□4He reaction, without high energy particles, would explain the excess heat, the 4He would be found in an unexpected place (outside heat-producing electrodes), and high-loading, x□1, in PdDx, would be required.

  8. Excess Mortality Attributable to Extreme Heat in New York City, 1997-2013.

    Science.gov (United States)

    Matte, Thomas D; Lane, Kathryn; Ito, Kazuhiko

    2016-01-01

    Extreme heat event excess mortality has been estimated statistically to assess impacts, evaluate heat emergency response, and project climate change risks. We estimated annual excess non-external-cause deaths associated with extreme heat events in New York City (NYC). Extreme heat events were defined as days meeting current National Weather Service forecast criteria for issuing heat advisories in NYC based on observed maximum daily heat index values from LaGuardia Airport. Outcomes were daily non-external-cause death counts for NYC residents from May through September from 1997 to 2013 (n = 337,162). The cumulative relative risk (CRR) of death associated with extreme heat events was estimated in a Poisson time-series model for each year using an unconstrained distributed lag for days 0-3 accommodating over dispersion, and adjusting for within-season trends and day of week. Attributable death counts were computed by year based on individual year CRRs. The pooled CRR per extreme heat event day was 1.11 (95%CI 1.08-1.14). The estimated annual excess non-external-cause deaths attributable to heat waves ranged from -14 to 358, with a median of 121. Point estimates of heat wave-attributable deaths were greater than 0 in all years but one and were correlated with the number of heat wave days (r = 0.81). Average excess non-external-cause deaths associated with extreme heat events were nearly 11-fold greater than hyperthermia deaths. Estimated extreme heat event-associated excess deaths may be a useful indicator of the impact of extreme heat events, but single-year estimates are currently too imprecise to identify short-term changes in risk.

  9. Heat-related mortality in India: excess all-cause mortality associated with the 2010 Ahmedabad heat wave.

    Directory of Open Access Journals (Sweden)

    Gulrez Shah Azhar

    Full Text Available In the recent past, spells of extreme heat associated with appreciable mortality have been documented in developed countries, including North America and Europe. However, far fewer research reports are available from developing countries or specific cities in South Asia. In May 2010, Ahmedabad, India, faced a heat wave where the temperatures reached a high of 46.8 °C with an apparent increase in mortality. The purpose of this study is to characterize the heat wave impact and assess the associated excess mortality.We conducted an analysis of all-cause mortality associated with a May 2010 heat wave in Ahmedabad, Gujarat, India, to determine whether extreme heat leads to excess mortality. Counts of all-cause deaths from May 1-31, 2010 were compared with the mean of counts from temporally matched periods in May 2009 and 2011 to calculate excess mortality. Other analyses included a 7-day moving average, mortality rate ratio analysis, and relationship between daily maximum temperature and daily all-cause death counts over the entire year of 2010, using month-wise correlations.The May 2010 heat wave was associated with significant excess all-cause mortality. 4,462 all-cause deaths occurred, comprising an excess of 1,344 all-cause deaths, an estimated 43.1% increase when compared to the reference period (3,118 deaths. In monthly pair-wise comparisons for 2010, we found high correlations between mortality and daily maximum temperature during the locally hottest "summer" months of April (r = 0.69, p<0.001, May (r = 0.77, p<0.001, and June (r = 0.39, p<0.05. During a period of more intense heat (May 19-25, 2010, mortality rate ratios were 1.76 [95% CI 1.67-1.83, p<0.001] and 2.12 [95% CI 2.03-2.21] applying reference periods (May 12-18, 2010 from various years.The May 2010 heat wave in Ahmedabad, Gujarat, India had a substantial effect on all-cause excess mortality, even in this city where hot temperatures prevail through much of April-June.

  10. Preparation of Palladium/Silver-Coated Polyimide Nanotubes: Flexible, Electrically Conductive Fibers

    OpenAIRE

    Lushi Kong; Guanchun Rui; Guangyu Wang; Rundong Huang; Ran Li; Jiajie Yu; Shengli Qi; Dezhen Wu

    2017-01-01

    A simple and practical method for coating palladium/silver nanoparticles on polyimide (PI) nanotubes is developed. The key steps involved in the process are silver ion exchange/reduction and displacement reactions between silver and palladium ions. With the addition of silver, the conductivity of the PI nanotubes is greatly enhanced. Further, the polyimide nanotubes with a dense, homogeneous coating of palladium nanoparticles remain flexible after heat treatment and show the possibility for u...

  11. Technologies for utilization of industrial excess heat: Potentials for energy recovery and CO2 emission reduction

    International Nuclear Information System (INIS)

    Broberg Viklund, Sarah; Johansson, Maria T.

    2014-01-01

    Highlights: • Technologies for recovery and use of industrial excess heat were investigated. • Heat harvesting, heat storage, heat utilization, and heat conversion technologies. • Heat recovery potential for Gävleborg County in Sweden was calculated. • Effects on global CO 2 emissions were calculated for future energy market scenarios. - Abstract: Industrial excess heat is a large untapped resource, for which there is potential for external use, which would create benefits for industry and society. Use of excess heat can provide a way to reduce the use of primary energy and to contribute to global CO 2 mitigation. The aim of this paper is to present different measures for the recovery and utilization of industrial excess heat and to investigate how the development of the future energy market can affect which heat utilization measure would contribute the most to global CO 2 emissions mitigation. Excess heat recovery is put into a context by applying some of the excess heat recovery measures to the untapped excess heat potential in Gävleborg County in Sweden. Two different cases for excess heat recovery are studied: heat delivery to a district heating system and heat-driven electricity generation. To investigate the impact of excess heat recovery on global CO 2 emissions, six consistent future energy market scenarios were used. Approximately 0.8 TWh/year of industrial excess heat in Gävleborg County is not used today. The results show that with the proposed recovery measures approximately 91 GWh/year of district heating, or 25 GWh/year of electricity, could be supplied from this heat. Electricity generation would result in reduced global CO 2 emissions in all of the analyzed scenarios, while heat delivery to a DH system based on combined heat and power production from biomass would result in increased global CO 2 emissions when the CO 2 emission charge is low

  12. Heat-Related Mortality in India: Excess All-Cause Mortality Associated with the 2010 Ahmedabad Heat Wave

    Science.gov (United States)

    Azhar, Gulrez Shah; Mavalankar, Dileep; Nori-Sarma, Amruta; Rajiva, Ajit; Dutta, Priya; Jaiswal, Anjali; Sheffield, Perry; Knowlton, Kim; Hess, Jeremy J.; Azhar, Gulrez Shah; Deol, Bhaskar; Bhaskar, Priya Shekhar; Hess, Jeremy; Jaiswal, Anjali; Khosla, Radhika; Knowlton, Kim; Mavalankar, Mavalankar; Rajiva, Ajit; Sarma, Amruta; Sheffield, Perry

    2014-01-01

    Introduction In the recent past, spells of extreme heat associated with appreciable mortality have been documented in developed countries, including North America and Europe. However, far fewer research reports are available from developing countries or specific cities in South Asia. In May 2010, Ahmedabad, India, faced a heat wave where the temperatures reached a high of 46.8°C with an apparent increase in mortality. The purpose of this study is to characterize the heat wave impact and assess the associated excess mortality. Methods We conducted an analysis of all-cause mortality associated with a May 2010 heat wave in Ahmedabad, Gujarat, India, to determine whether extreme heat leads to excess mortality. Counts of all-cause deaths from May 1–31, 2010 were compared with the mean of counts from temporally matched periods in May 2009 and 2011 to calculate excess mortality. Other analyses included a 7-day moving average, mortality rate ratio analysis, and relationship between daily maximum temperature and daily all-cause death counts over the entire year of 2010, using month-wise correlations. Results The May 2010 heat wave was associated with significant excess all-cause mortality. 4,462 all-cause deaths occurred, comprising an excess of 1,344 all-cause deaths, an estimated 43.1% increase when compared to the reference period (3,118 deaths). In monthly pair-wise comparisons for 2010, we found high correlations between mortality and daily maximum temperature during the locally hottest “summer” months of April (r = 0.69, pheat (May 19–25, 2010), mortality rate ratios were 1.76 [95% CI 1.67–1.83, pheat wave in Ahmedabad, Gujarat, India had a substantial effect on all-cause excess mortality, even in this city where hot temperatures prevail through much of April-June. PMID:24633076

  13. Improvements in or relating to devices for conducting excess heat away from heat sources

    International Nuclear Information System (INIS)

    Cooke-Yarborough, E.H.

    1976-01-01

    Reference is made to radioisotope powered heat engines. Should such an engine stop working for any reason the radioisotope heat source will continue to generate heat, and this may cause overheating and possible damage to the engine as well as the heat source. A device is described for conducting excess heat from the heat source to a heat sink but which in normal operation of the engine will impede heat conduction and so reduce thermal losses. The device may be used to support and/or locate the heat source. Constructional and operational details are given. (U.K.)

  14. Evidence for hydrogen-assisted recovery of cold-worked palladium: hydrogen solubility and mechanical properties studies

    Directory of Open Access Journals (Sweden)

    Maria Ferrer

    2017-07-01

    Full Text Available The influence of hydrogen as an agent to accelerate the thermal recovery of cold-worked palladium has been investigated. The techniques used to characterize the effects of hydrogen on the thermal recovery of palladium were hydrogen solubility and mechanical property measurements. Results show that the presence of modest amounts of hydrogen during annealing of cold-worked palladium does enhance the degree of thermal recovery, with a direct correlation between the amount of hydrogen during annealing and the degree of recovery. The results indicate that the damage resulting from cold-working palladium can be more effectively and efficiently reversed by suitable heat treatments in the presence of appropriate amounts of hydrogen, as compared to heat treatment in vacuum. The somewhat novel technique of using changes in the hydrogen solubility of palladium as an indicator of thermal recovery has been validated and complements the more traditional technique of mechanical property measurements.

  15. Co-deposition of palladium with hydrogen isotopes

    International Nuclear Information System (INIS)

    Dash, J.; Ambadkar, A.

    2006-01-01

    Palladium was co-deposited with hydrogen isotopes on a Pd cathode. This resulted in enhanced production of excess thermal power. After electrolysis the Pd Lβ/ Lα ratio was found to be increased in characteristic X-ray spectra from localized, microscopic areas on the surface of the Pd cathode. This suggests the possibility that appreciable amounts of silver are present in these areas. (authors)

  16. Excessive heat removal due to feedwater system malfunction

    International Nuclear Information System (INIS)

    Beader, D.; Peterlin, G.

    1986-01-01

    Excessive heat removal transient of the Krsko Nuclear Power Plant, caused by steam generators feedwater system malfunctions was simulated by RELAP5/MOD1 computer code. The results are increase of power and reactor scram caused by high-high steam generator level. (author)

  17. Chemical recovery of a palladium-103 from irradiated silver target

    International Nuclear Information System (INIS)

    Lapshina, E.V.; Kokhanyuk, V.M.; Zhuikov, B.L.; Myasoedova, G.V.; Zakhartchenko, E.A.; Phillips, D.R.; Jamriska, D.J.

    2003-01-01

    The goal of this work is to develop an extraction method of no-carrier-added palladium-103 from silver. Metallic silver targets were irradiated by protons with the energy of 60-140 MeV to generate palladium-103. Other radioactive isotopes of rhodium, ruthenium, technetium, palladium and silver are also formed at the same time. Two methods of Pd-103 recovering from irradiated silver target are considered. The first one includes the dissolving of the irradiated silver target in nitric acid followed by adding of hydrochloric acid to the solution. Palladium with rhodium, ruthenium and technetium completely remained in solution while silver was precipitated in the form of silver chloride. Extraction of palladium from the obtained solution was provided by the formation of palladium complex with a chelate sorbent which is specific to palladium in acidic solutions. The sorbent makes it possible to separate palladium from admixtures of rhodium, ruthenium and technetium isotopes. The polymeric complex-forming sorbent of fibrous structure with the groups of 3 (5) - methylpyrazole (POLYORGS-15n) is used. An other possible method has been also studied. It includes again dissolving of metallic silver in nitric acid, but does not need silver chloride precipitation. Silver may be sorbed by the complex-forming sorbents, but its sorption is very sensitive to acid concentration. Chelate sorbents of fibrous structure with the groups of amidoxime and hydrazidine (POLYORGS-33n) have been successfully used in our experiments. A high efficiency of palladium extraction by POLYORGS-33n from 2-4 M nitric acid solutions was achieved. Concentrated hydrochloric acid (without heating) was used for palladium desorption with higher yield than in the first method. (authors)

  18. Kinetic Characteristics of Hydrogen Transfer Through Palladium-Modified Membrane

    Science.gov (United States)

    Petriev, I. S.; Frolov, V. Yu.; Bolotin, S. N.; Baryshev, M. G.; Kopytov, G. F.

    2018-01-01

    The paper deals with hydrogen transfer through Pd-23%Ag alloy membrane, the surface of which is modified by the electrolytic deposition of highly dispersed palladium. The dependence between the density of hydrogen flow and its excess pressure on the input surface of membrane is well approximated by the first-order curve. This fact indicates that the process of hydrogen permeability is defined by its dissociation on the input surface. Activation energy of this process is 47.9 kJ/mol which considerably exceeds that of the process of hydrogen transfer through palladium (22-30 kJ/mol). This confirms the fact that the chemisorption is a rate-controlling step of the hydrogen transfer through membrane.

  19. Production of 4He in D2-Loaded Palladium-Carbon Catalyst I

    International Nuclear Information System (INIS)

    Clarke, W. Brian

    2003-01-01

    A series of lead vials of internal volume 1.0 cm 3 were charged with ∼200 mg of carbon catalyst containing 0.5% Pd and 0.4% Pd. The vials were clamped to stainless steel manifolds on a vacuum line, then pumped out and filled with high-purity H 2 or D 2 at a pressure of 152 cm Hg and a temperature of 23 deg. C. Several vials contained ordinary activated carbon instead of palladium-carbon, and some vials contained only H 2 or D 2 . All the vials were stored in a sandbox heated to ∼ 200 deg. C for times up to 45 days before mass spectrometer measurements of 3 He and 4 He were made. No evidence was found for the high concentrations of 4 He claimed in similar experiments by several other researchers. The upper limit for the concentration excess of 4 He in D 2 in vials containing palladium-carbon is 11 ppt (parts per trillion) at the 95% confidence level. This limit for 4 He may be compared with previous claims in similar experiments of 100 ppm (parts per million) by Case and 11 ppm by George and McKubre et al

  20. Economic feasibility of district heating delivery from industrial excess heat: A case study of a Swedish petrochemical cluster

    International Nuclear Information System (INIS)

    Morandin, Matteo; Hackl, Roman; Harvey, Simon

    2014-01-01

    The present work discusses the potential and the economic feasibility of DH (district heating) delivery using industrial excess heat from a petrochemical cluster at the Swedish West Coast. Pinch Analysis was used for estimating the DH capacity targets and for estimating the cost of heat exchanger installation. A discounted cash flow rate of return of 10% was used as a criterion for identifying the minimum yearly DH delivery that should be guaranteed for a given DH capacity at different DH sales prices. The study was conducted for the current scenario in which no heat recovery is achieved between the cluster plants and for a possible future scenario in which 50% of the fuel currently used for heating purposes is saved by increasing the heat recovery at the site. The competition between excess heat export and local energy efficiency measures is also discussed in terms of CO 2 emission consequences. The maximum capacity of DH delivery amounts today to around 235 MW, which reduces to 110 MW in the future scenario of increased site heat recovery. The results of our analysis show that feasible conditions exist that make DH delivery profitable in the entire capacity range. - Highlights: • Pinch Analysis targeting approach and short-cut cost accounting procedure. • Economic analysis for different DH delivery capacities up to maximum targets. • Sensitivity analysis of heat sales prices. • Parallel plants and cluster wide heat collection systems considered. • Competition between cluster internal heat recovery and excess heat export is discussed

  1. Biogas production supported by excess heat – A systems analysis within the food industry

    International Nuclear Information System (INIS)

    Broberg Viklund, Sarah; Lindkvist, Emma

    2015-01-01

    Highlights: • A systems analysis when moving from external to internal production and use of biogas at an industry. • The aim is to study the impacts on greenhouse gas emissions and economics from this switch. • The study compares the choice of using biogas or industrial excess heat to heat the digester. • Internal biogas production supported by excess heat has environmental and economic benefits. - Abstract: The aim of this paper was to study the effects on greenhouse gases and economics when a change is made in the use of industrial organic waste from external production and use of biogas (A) to internal production and use (B). The two different system solutions are studied through a systems analysis based on an industrial case. The baseline system (A) and a modified system (B) were compared and analysed. Studies show that industrial processes considered as integrated systems, including the exchange of resources between industries, can result in competitive advantages. This study focuses on the integration of internally produced biogas from food industry waste produced by a food company and the use of excess heat. Two alternative scenarios were studied: (1) the use of available excess heat to heat the biogas digester and (2) the use of a part of the biogas produced to heat the biogas digester. This study showed that the system solution, whereby excess heat rather than biogas is used to heat the biogas digester, was both environmentally and economically advantageous. However, the valuation of biomass affects the magnitude of the emissions reduction. Implementing this synergistic concept will contribute to the reaching of European Union climate targets

  2. High stability of palladium/kieselguhr composites during absorption/desorption cycling for hydrogen isotope separation

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Yang, E-mail: lei.y@outlook.com; Liu, Xiaopeng; Li, Shuo; Jiang, Lijun; Zhang, Chao; Li, Shuai; He, Di; Wang, Shumao

    2016-12-15

    Highlights: • Pd/K composites with as high as 57 wt.% of Pd have been successfully prepared. • Palladium particles can be effectively packed into the pores of kieselguhr substrates. • Variation of heat-treatment temperatures hardly affect hydrogen absorption capacity and hydrogen saturation time of the Pd/K. • Anti-pulverization property of Pd/K can be improved by packing palladium into the kieselguhr internal pores and heating at 1300 °C. - Abstract: Palladium/kieselguhr (Pd/K) composites with 57 wt.% of Pd were prepared by an improved dipping and thermal decomposition method and heated at elevated temperature to reduce breakdown during hydrogenation-dehydrogenation cycles. The hydrogen absorption kinetic properties of the samples heated at different temperatures were tested under the condition of 20 °C with 100 kPa hydrogen pressure. The 1300 °C heated Pd/K composites were repeated up to 4010 absorption and desorption cycles at temperature ranges between −40 °C and 200 °C. The results show that the phase structure, hydrogen absorption capacity and hydrogen saturation time of the Pd/K were not affected by the change of heat-treated temperatures. And after heat treatment at 1300 °C, the Pd/K particles were strengthened and fraction of larger than 80 mesh were as high as 93.4%.

  3. Preparation of Palladium/Silver-Coated Polyimide Nanotubes: Flexible, Electrically Conductive Fibers.

    Science.gov (United States)

    Kong, Lushi; Rui, Guanchun; Wang, Guangyu; Huang, Rundong; Li, Ran; Yu, Jiajie; Qi, Shengli; Wu, Dezhen

    2017-11-02

    A simple and practical method for coating palladium/silver nanoparticles on polyimide (PI) nanotubes is developed. The key steps involved in the process are silver ion exchange/reduction and displacement reactions between silver and palladium ions. With the addition of silver, the conductivity of the PI nanotubes is greatly enhanced. Further, the polyimide nanotubes with a dense, homogeneous coating of palladium nanoparticles remain flexible after heat treatment and show the possibility for use as highly efficient catalysts. The approach developed here is applicable for coating various noble metals on a wide range of polymer matrices, and can be used for obtaining polyimide nanotubes with metal loaded on both the inner and outer surface.

  4. Preparation of Palladium/Silver-Coated Polyimide Nanotubes: Flexible, Electrically Conductive Fibers

    Directory of Open Access Journals (Sweden)

    Lushi Kong

    2017-11-01

    Full Text Available A simple and practical method for coating palladium/silver nanoparticles on polyimide (PI nanotubes is developed. The key steps involved in the process are silver ion exchange/reduction and displacement reactions between silver and palladium ions. With the addition of silver, the conductivity of the PI nanotubes is greatly enhanced. Further, the polyimide nanotubes with a dense, homogeneous coating of palladium nanoparticles remain flexible after heat treatment and show the possibility for use as highly efficient catalysts. The approach developed here is applicable for coating various noble metals on a wide range of polymer matrices, and can be used for obtaining polyimide nanotubes with metal loaded on both the inner and outer surface.

  5. Determination of palladium content in palladium-alumina/palladium-silica/palladium-tin oxide catalyst for nuclear reactor applications

    International Nuclear Information System (INIS)

    Sharma, P.K.; Bassan, M.K.T.; Avhad, D.K.; Singhal, R.K.

    2012-01-01

    Alumina and silica act as support for finely divided palladium metal powder in synthesis of catalyst. These catalyst (Pd-Al 2 O 3 , Pd-SiO 2 and Pd-SnO 2 ) used in nuclear power reactor (moderator cover gas system) for the conversion of hydrogen. In Indian nuclear power programme these catalyst are regularly used in Kaiga 1 and 2 and Rajasthan atomic power plant 3 and 4. The performance of the catalyst, solely depends on the concentration of palladium, which is the active component in this catalyst composition. Therefore it is highly desirable to have rouged analytical methodology for the accurate estimation of palladium. Leaching of Pd from the bulk matrix is tedious due to the less reactive nature of Pd therefore complete solubilization of the matrix is carried out by fusion method

  6. Titanium tritide radioisotope heat source development: palladium-coated titanium hydriding kinetics and tritium loading tests

    International Nuclear Information System (INIS)

    Van Blarigan, Peter; Shugard, Andrew D.; Walters, R. Tom

    2012-01-01

    We have found that a 180 nm palladium coating enables titanium to be loaded with hydrogen isotopes without the typical 400-500 C vacuum activation step. The hydriding kinetics of Pd coated Ti can be described by the Mintz-Bloch adherent film model, where the rate of hydrogen absorption is controlled by diffusion through an adherent metal-hydride layer. Hydriding rate constants of Pd coated and vacuum activated Ti were found to be very similar. In addition, deuterium/tritium loading experiments were done on stacks of Pd coated Ti foil in a representative-size radioisotope heat source vessel. The experiments demonstrated that such a vessel could be loaded completely, at temperatures below 300 C, in less than 10 hours, using existing department-of-energy tritium handling infrastructure.

  7. Analysis of an effective solution to excessive heat supply in a city primary heating network using gas-fired boilers for peak-load compensation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hai-Chao; Jiao, Wen-Ling; Zou, Ping-Hua; Liu, Jing-Cheng [School of Municipal and Environmental Engineering, Harbin Institute of Technology, mail box 2645, 202 Haihe Road, Nangang District, Harbin 150090 (China)

    2010-11-15

    Through investigation of the Dengfeng heating network in the city of Daqing, China, for the 2007-2008 heating season, we found serious problems of excessive heat supply in the primary heating network. Therefore, we propose the application of gas-fired boilers in underperforming heating substations as peak-load heat sources to effectively adapt to the regulation demands of seasonal heat-load fluctuations and reduce the excessive heat supply. First, we calculated the excessive heat supply rates (EHSRs) of five substations using detailed investigative data. We then discussed the feasibility of the proposed scheme providing energy savings from both energetic and exergetic points of view. The results showed that the average EHSR of the five substations between January and March was 20.57% of the gross heat production but consequently reduced to 6.24% with the installation of the gas-fired boilers. Therefore, the combined heating scheme with coal as the basic heat-source and gas-fired boilers as peak-load heat sources is energy-efficient to some extent, although requires the use of natural gas. Meanwhile, the exergy decreased by 10.97%, which indicates that the combined heating scheme effectively reduces the primary energy consumption and pollutant emission of the heating systems. (author)

  8. Thermal, thermoelectric, and cathode poisoning effects in cold fusion experiments

    International Nuclear Information System (INIS)

    Keesing, R.G.; Greenhow, R.C.; Cohler, M.D.; McQuillan, A.J.

    1991-01-01

    This paper reports on an unsuccessful attempt to repeat the observations by Fleischmann and Pons of cold nuclear fusion in deuterium-charged palladium; no excess heat is found, nor is any gamma or neutron activity identified. Peltier heating at the palladium/platinum junction is investigated, but no effects are seen; the possibility remains, however, that a large Peltier coefficient may arise for deuterium concentrations that render the palladium-deuterium semiconducting. Finally, the effects of poisoning the palladium with cyanide were investigated

  9. Demonstration technology development of new hydrogen energy; Shinsuiso energy jissho gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This report describes results of the study on the excess heat generation phenomenon during the electrolysis of heavy water using palladium metals as electrode in FY 1995. For the measurements of excess heat using an open type electrolysis cell during the excess heat generation demonstration model tests, significant excess heat beyond the range of input was not measured both for ICARUS-1 and for ICARUS-2. For the measurements using a fuel cell, high absorbing rate more than 0.85 was stably achieved for highly pure Pd electrode material by heat treatment and surface treatment. The excess heat could be reproduced for plural tests. The heat recovery rate more than 98% was obtained using the NHE type flow calorimetric system. The excess heat measurements using this are examined. For the reactive palladium materials, various materials ranging from single crystal to cold working polycrystal materials were systematically used for the absorbing experiments. Benchmark tests were also conducted through the cooperation with related researchers. 18 refs., 135 figs., 28 tabs.

  10. Development of polymeric palladium-nanoparticle membrane-installed microflow devices and their application in hydrodehalogenation.

    Science.gov (United States)

    Yamada, Yoichi M A; Watanabe, Toshihiro; Ohno, Aya; Uozumi, Yasuhiro

    2012-02-13

    We have developed a variety of polymeric palladium-nanoparticle membrane-installed microflow devices. Three types of polymers were convoluted with palladium salts under laminar flow conditions in a microflow reactor to form polymeric palladium membranes at the laminar flow interface. These membranes were reduced with aqueous sodium formate or heat to create microflow devices that contain polymeric palladium-nanoparticle membranes. These microflow devices achieved instantaneous hydrodehalogenation of aryl chlorides, bromides, iodides, and triflates by 10-1000 ppm within a residence time of 2-8 s at 50-90 °C by using safe, nonexplosive, aqueous sodium formate to quantitatively afford the corresponding hydrodehalogenated products. Polychlorinated biphenyl (10-1000 ppm) and polybrominated biphenyl (1000 ppm) were completely decomposed under similar conditions, yielding biphenyl as a fungicidal compound. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Laccases as palladium oxidases.

    Science.gov (United States)

    Mekmouche, Yasmina; Schneider, Ludovic; Rousselot-Pailley, Pierre; Faure, Bruno; Simaan, A Jalila; Bochot, Constance; Réglier, Marius; Tron, Thierry

    2015-02-01

    The first example of a coupled catalytic system involving an enzyme and a palladium(ii) catalyst competent for the aerobic oxidation of alcohol in mild conditions is described. In the absence of dioxygen, the fungal laccase LAC3 is reduced by a palladium(0) species as evidenced by the UV/VIS and ESR spectra of the enzyme. During the oxidation of veratryl alcohol performed in water, at room temperature and atmospheric pressure, LAC3 regenerates the palladium catalyst, is reduced and catalyzes the four-electron reduction of dioxygen into water with no loss of enzyme activity. The association of a laccase with a water-soluble palladium complex results in a 7-fold increase in the catalytic efficiency of the complex. This is the first step in the design of a family of renewable palladium catalysts for aerobic oxidation.

  12. Relationships Between Excessive Heat and Daily Mortality over the Coterminous U.S

    Science.gov (United States)

    Crosson, William L.; Al-Hamdan, Mohammad Z.; Estes, Maury G., Jr.; Estes, Sue M.; Quattrochi, Dale A.

    2015-01-01

    In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization, it is very likely that extreme heat events (EHEs) will become more common and more severe in the U.S. Using National Land Data Assimilation System (NLDAS) meteorological reanalysis data, we have developed several measures of extreme heat to enable assessments of the impacts of heat on public health over the coterminous U.S. These measures include daily maximum and minimum air temperatures, daily maximum heat indices and a new heat stress variable called Net Daily Heat Stress (NDHS) that gives an integrated measure of heat stress (and relief) over the course of a day. All output has been created on the NLDAS 1/8 degree (approximately 12 km) grid and aggregated to the county level, which is the preferred geographic scale of analysis for public health researchers. County-level statistics have been made available through the Centers for Disease Control and Prevention (CDC) via the Wide-ranging Online Data for Epidemiologic Research (WONDER) system. We have examined the relationship between excessive heat events, as defined in eight different ways from the various daily heat metrics, and heat-related and all-cause mortality defined in CDC's National Center for Health Statistics 'Multiple Causes of Death 1999-2010' dataset. To do this, we linked daily, county-level heat mortality counts with EHE occurrence based on each of the eight EHE definitions by region and nationally for the period 1999-2010. The objectives of this analysis are to determine (1) whether heat-related deaths can be clearly tied to excessive heat events, (2) what time lags are critical for predicting heat-related deaths, and (3) which of the heat metrics correlates best with mortality in each US region. Results show large regional differences in the correlations between heat and mortality. Also, the heat metric that provides the best indicator of mortality varied by region

  13. Conventional Physics can Explain Excess Heat in the Fleischmann-Pons Cold Fusion Effect

    Science.gov (United States)

    Chubb, Scott

    2011-03-01

    In 1989, when Fleischmann and Pons (FP) claimed they had created room temperature, nuclear fusion in a solid, a firestorm of controversy erupted. Beginning in 1991, the Office of Naval Research began a decade-long study of the FP excess heat effect. This effort documented the fact that the excess heat that FP observed is the result of a form of nuclear fusion that can occur in solids at reduced temperature, dynamically, through a deuteron (d)+d?helium-4 reaction, without high-energy particles or ? rays. This fact has been confirmed at SRI and at a number of other laboratories (most notably in the laboratory of Y. Arata, located at Osaka University, Japan). A key reason this fact has not been accepted is the lack of a cogent argument, based on fundamental physical ideas, justifying it. In the paper, this question is re-examined, based on a generalization of conventional energy band theory that applies to finite, periodic solids, in which d's are allowed to occupy wave-like, ion band states, similar to the kinds of states that electrons occupy in ordinary metals. Prior to being experimentally observed, the Ion Band State Theory of cold fusion predicted a potential d+d?helium-4 reaction, without high energy particles, would explain the excess heat, the helium-4 would be found in an unexpected place (outside heat- producing electrodes), and high-loading, x?1, in PdDx, would be required.

  14. Excessive heat-associated gingival necrosis: a case report.

    Science.gov (United States)

    Barnes, P L; Rossi-Fedele, G

    2017-09-01

    Heat-delivery devices have been associated with relatively high temperatures. Previous basic research studies suggest that the risk for periodontal tissues is negligible, as the presence of the root filling materials, amongst other factors, reduce the risk of overheating. This report describes the case of a 45 year old male, who was undergoing restorative treatment in a multi-specialty dental practice. As part of his overall treatment planning, orthograde root canal retreatment for his maxillary left incisor teeth was deemed necessary, due to chronic apical periodontitis. Following cold lateral compaction, the coronal portion of the core material was severed using a System B Heat Source (Kerr Dental, Orange, CA, USA), with the patient reporting pain as well as a burning sensation. The following day the patient was seen by a periodontist and gingival necrosis in relation to the central incisor was found. The most likely cause of the complication was considered to be excessive heat during the operative procedure. The patient was followed up for a 2-year period and the soft tissues returned to their original condition without the need for periodontal treatment. © 2017 Australian Dental Association.

  15. Identification of Excess Heat Utilisation Potential using GIS: Analysis of Case Studies for Denmark

    DEFF Research Database (Denmark)

    Bühler, Fabian; Petrovic, Stefan; Ommen, Torben Schmidt

    2017-01-01

    feasibility of using this approach is evaluated for four scenarios. Special focus is placed on the challenges for the connection of excess heat sources to heat consumers, as well as tax schemes applicable in Denmark. To account for uncertainties in the model input, Monte Carlo simulations and Morris...

  16. Excess heat production in Pd/D during periodic pulse discharge current in various conditions

    International Nuclear Information System (INIS)

    Karabut, A.B.

    2006-01-01

    Experimental date from low-energy nuclear reactions (LENR) in condensed media are presented. The nuclear reactions products were found in solid cathode media used in glow discharge. Apparently, the nuclear reactions were initiated when bombarding the cathode surface by plasma ions with the energy of 1.0 - 2.0 keV. Excess heat from a high current glow discharge reaction in D 2 , Xe, and Kr using cathodes already charged with preliminary deuterium-charged Pd and Ti cathode samples are given. Excess heat up to 10-15 W and efficiency up to 130% were recorded under the experiments for Pd cathode samples in D 2 discharge. Excess heat up to 5 W and efficiency up to 150% were recorded for Pd cathodes that were charged with deuterium before the run, in Xe and Kr discharges. At the same time excess heat was not observed for pure Pd cathode samples in Xe and Kr discharges. The formation of impurity nuclides ( 7 Li, 13 C, 15 N, 20 Ne, 29 Si, 44 Ca, 48 Ca, 56 Fe, 57 Fe, 59 Co, 64 Zn, 66 Zn, 75 As, 107 Ag, 109 Ag, 110 Cd, 111 Cd, 112 Cd, 114 Cd and 115 In) with 'the efficiency up to 10 13 at./s was recorded. The isotopic ratios of these new nuclides were quite different from the natural ratios. Soft X-ray radiation from the solid-state cathode with the intensity up to 0.01 Gy/s was recorded in experiments with discharges in H 2 , D 2 , Ar, Xe, and Kr. The X-ray radiation was observed in bursts of up to 10 6 photons, with up to 10 5 bursts per second while the discharge was formed and within 100 ms after turning off the discharge current. The results of the X-ray radiation registration showed that the excited energy levels have a lifetime up to 100 ms or more, and the energy of 1.2 - 2.5 keV. A possible mechanism for producing excess heat and nuclear transmutation reactions in the solid medium with the excited energy levels is considered

  17. Method for reducing excess heat supply experienced in typical Chinese district heating systems by achieving hydraulic balance and improving indoor air temperature control at the building level

    DEFF Research Database (Denmark)

    Zhang, Lipeng; Gudmundsson, Oddgeir; Thorsen, Jan Eric

    2016-01-01

    A common problem with Chinese district heating systems is that they supply more heat than the actual heat demand. The reason for this excess heat supply is the general failure to use control devices to adjust the indoor temperature and flow in the building heating systems in accordance with the a......A common problem with Chinese district heating systems is that they supply more heat than the actual heat demand. The reason for this excess heat supply is the general failure to use control devices to adjust the indoor temperature and flow in the building heating systems in accordance...... with the actual heat demand. This results in 15-30% of the total supplied heat being lost. This paper proposes an integrated approach that aims to reduce the excess heat loss by introducing pre-set thermostatic radiator valves combined with automatic balancing valves. Those devices establish hydraulic balance...... that once the hydraulic balance is achieved and indoor temperatures are controlled with this integrated approach, 17% heat savings and 42.8% pump electricity savings can be achieved. The energy savings will also have a positive environmental effect with seasonal reductions of 11 kg CO2, 0.1 kg SO2, and 0...

  18. Sensitization to palladium in Europe

    DEFF Research Database (Denmark)

    Muris, Joris; Goossens, An; Gonçalo, Margarida

    2015-01-01

    BACKGROUND: Recently, sodium tetrachloropalladate (Na2 PdCl4 ) was found to be a more sensitive palladium patch test allergen than palladium dichloride (PdCl2 ). OBJECTIVES: To determine the optimal test concentration of Na2 PdCl4 , to evaluate the prevalence of palladium sensitization with Na2 P...... patch test concentration. Sensitization to palladium is almost as prevalent as sensitization to nickel. The sex distribution is different between nickel-sensitized and palladium-sensitized patients, suggesting different sources of exposure.......Cl4 and PdCl2 , and to compare the results with nickel sensitization in a European multicentre study. MATERIALS AND METHODS: In addition to the European or national baseline series including NiSO4 ·6H2 0 5% pet., consecutive patients were tested with PdCl2 and Na2 PdCl4 2%, 3% and 4% pet. in eight...... European dermatology clinics. The age and sex distributions were also evaluated in patients sensitized to nickel and palladium. RESULTS: In total, 1651 patients were tested. Relative to 3% Na2 PdCl4 , 4% Na2 PdCl4 did not add any information. Two per cent Na2 PdCl4 resulted in more doubtful reactions...

  19. Method for reducing excess heat supply experienced in typical Chinese district heating systems by achieving hydraulic balance and improving indoor air temperature control at the building level

    International Nuclear Information System (INIS)

    Zhang, Lipeng; Gudmundsson, Oddgeir; Thorsen, Jan Eric; Li, Hongwei; Li, Xiaopeng; Svendsen, Svend

    2016-01-01

    A common problem with Chinese district heating systems is that they supply more heat than the actual heat demand. The reason for this excess heat supply is the general failure to use control devices to adjust the indoor temperature and flow in the building heating systems in accordance with the actual heat demand. This results in 15–30% of the total supplied heat being lost. This paper proposes an integrated approach that aims to reduce the excess heat loss by introducing pre-set thermostatic radiator valves combined with automatic balancing valves. Those devices establish hydraulic balance, and stabilize indoor temperatures. The feasibility and the energy consumption reduction of this approach were verified by means of simulation and a field test. By moving the system from centrally planned heat delivery to demand-driven heat delivery, excess heat loss can be significantly reduced. Results show that once the hydraulic balance is achieved and indoor temperatures are controlled with this integrated approach, 17% heat savings and 42.8% pump electricity savings can be achieved. The energy savings will also have a positive environmental effect with seasonal reductions of 11 kg CO_2, 0.1 kg SO_2, and 0.03 kg NO_x per heating square meter for a typical case in Harbin. - Highlights: • Two real cases reflect the temperature and flow control situation of heating systems in China. • Pre-set radiator valves with automatic balancing valves create dynamic hydraulic balance. • IDA-ICE simulation shows 17% heat saving and 48% pump electricity saving. • This approach can improve the comfort level of multi-storey/high-rise residential buildings. • This approach can reduce excess heat supply and bring out positive environmental impacts.

  20. Excess heat production in Pd/D during periodic pulse discharge current in various conditions

    Energy Technology Data Exchange (ETDEWEB)

    Karabut, A.B. [FSUE ' LUCH' , 24 Zheleznodorozhnaya St., Podolsk, Moscow Region 142100 (Russian Federation)

    2006-07-01

    Experimental date from low-energy nuclear reactions (LENR) in condensed media are presented. The nuclear reactions products were found in solid cathode media used in glow discharge. Apparently, the nuclear reactions were initiated when bombarding the cathode surface by plasma ions with the energy of 1.0 - 2.0 keV. Excess heat from a high current glow discharge reaction in D{sub 2}, Xe, and Kr using cathodes already charged with preliminary deuterium-charged Pd and Ti cathode samples are given. Excess heat up to 10-15 W and efficiency up to 130% were recorded under the experiments for Pd cathode samples in D{sub 2} discharge. Excess heat up to 5 W and efficiency up to 150% were recorded for Pd cathodes that were charged with deuterium before the run, in Xe and Kr discharges. At the same time excess heat was not observed for pure Pd cathode samples in Xe and Kr discharges. The formation of impurity nuclides ({sup 7}Li, {sup 13}C, {sup 15}N, {sup 20}Ne, {sup 29}Si, {sup 44}Ca, {sup 48}Ca, {sup 56}Fe, {sup 57}Fe, {sup 59}Co, {sup 64}Zn, {sup 66}Zn, {sup 75}As, {sup 107}Ag, {sup 109}Ag, {sup 110}Cd, {sup 111}Cd, {sup 112}Cd, {sup 114}Cd and {sup 115}In) with 'the efficiency up to 10{sup 13} at./s was recorded. The isotopic ratios of these new nuclides were quite different from the natural ratios. Soft X-ray radiation from the solid-state cathode with the intensity up to 0.01 Gy/s was recorded in experiments with discharges in H{sub 2}, D{sub 2}, Ar, Xe, and Kr. The X-ray radiation was observed in bursts of up to 10{sup 6} photons, with up to 10{sup 5} bursts per second while the discharge was formed and within 100 ms after turning off the discharge current. The results of the X-ray radiation registration showed that the excited energy levels have a lifetime up to 100 ms or more, and the energy of 1.2 - 2.5 keV. A possible mechanism for producing excess heat and nuclear transmutation reactions in the solid medium with the excited energy levels is considered.

  1. Excess heat from kraft pulp mills: Trade-offs between internal and external use in the case of Sweden-Part 1: Methodology

    International Nuclear Information System (INIS)

    Svensson, Inger-Lise; Joensson, Johanna; Berntsson, Thore; Moshfegh, Bahram

    2008-01-01

    Excess heat from a kraft pulp mill can be used either internally to increase the level of efficiency in the mill, or externally for example as district heating. This paper presents an approach to investigate the competition between external and internal use through modelling the pulp mill and an energy company (ECO) within the same system boundary. Three different sizes of ECOs with different district heating demands are studied. To investigate the competitiveness of using industrial excess heat as district heating compared with other heat production techniques, the option of investing in excess heat use is introduced, along with the possibility for the ECO to invest in biomass combined heat and power (CHP), waste CHP and natural gas combined cycle (NGCC). To evaluate the robustness of the model, alternative solutions are identified and will be used as a comparison to the optimal solutions. The model has been verified by comparing the results with previous studies concerning kraft pulp mills and with related studies regarding district heating and real ECOs. Finally, the approach presented in this part of the study will be used in the second part in order to investigate the trade-off between internal and external use of excess heat under different future energy market scenarios

  2. Correlation between abnormal deuterium flux and heat flow in a D/Pd system

    International Nuclear Information System (INIS)

    Li Xingzhong; Liu Bin; Tian Jian; Wei Qingming; Zhou Rui; Yu Zhiwu

    2003-01-01

    Deuterium flux through the thin wall of a palladium tube has been studied by monitoring gas pressure and temperature. A high-precision calorimeter (Calvet) was used to detect heat flow when the heater was shut down and the palladium tube was cooling down slowly. At certain temperatures an abnormal deuterium flux appeared. This deuterium flux reached a peak when the temperature of the palladium was decreasing. This abnormal deuterium flux differs from the monotonic feature of a normal diffusive flux and is accompanied by a heat flow

  3. Palladium-cobalt particles as oxygen-reduction electrocatalysts

    Science.gov (United States)

    Adzic, Radoslav [East Setauket, NY; Huang, Tao [Manorville, NY

    2009-12-15

    The present invention relates to palladium-cobalt particles useful as oxygen-reducing electrocatalysts. The invention also relates to oxygen-reducing cathodes and fuel cells containing these palladium-cobalt particles. The invention additionally relates to methods for the production of electrical energy by using the palladium-cobalt particles of the invention.

  4. Case study of an organic Rankine cycle applied for excess heat recovery: Technical, economic and policy matters

    International Nuclear Information System (INIS)

    Lemmens, Sanne; Lecompte, Steven

    2017-01-01

    Highlights: • Case study of an organic Rankine cycle for heat recovery from an industrial kiln. • The costs and financial feasibility of the system are discussed in detail. • The cost structure is most defined by the capital costs, annual costs are limited. • The system is financially feasible, but subsidies remain important. • The results are most sensitive to changes in load hours and electricity price. - Abstract: Many industrial processes inevitably produce excess heat as by-product. Recovering this heat is a matter of waste management and provides opportunities to improve the energy use efficiency. The excess heat can be used for heating purposes (e.g., in processes, or delivered to district heating systems or buildings) or to generate electricity. An increasingly applied technology for industrial excess heat recovery is the organic Rankine cycle (ORC), suitable to recover low-grade heat from 90 °C onwards. Although ORCs are studied intensively, few studies have examined the economics of commissioned ORC systems. This paper investigates a 375 kW_g_r_o_s_s ORC system employed for flue gas heat recovery from an industrial kiln in Flanders, Belgium. The purpose of the study is twofold: providing insight into a practical ORC case; and evaluating the financial feasibility while taking the specific policy circumstances into account. The financial appraisal takes account of the specific technical setup, the diverse costs of the system, the external economic parameters, and the policy circumstances in Europe, Belgium and Flanders. A sensitivity analysis illustrates the influence of each parameter on the results. The analysis demonstrates the dominance of the investment costs (4217 €_2_0_1_3/kW_g_r_o_s_s) in the expenses. Under the valid conditions the investment has a positive financial return, but the financial support from the government is indispensable. Finally, the sensitivity analysis reveals the importance of attaining sufficient load hours and the

  5. Palladium transport in SiC

    International Nuclear Information System (INIS)

    Olivier, E.J.; Neethling, J.H.

    2012-01-01

    Highlights: ► We investigate the reaction of Pd with SiC at typical HTGR operating temperatures. ► The high temperature mobility of palladium silicides within polycrystalline SiC was studied. ► Corrosion of SiC by Pd was seen in all cases. ► The preferential corrosion and penetration of Pd along grain boundaries in SiC was found. ► The penetration and transport of palladium silicides in SiC along grain boundaries was found. - Abstract: This paper reports on a transmission electron microscopy (TEM) and scanning electron microscopy (SEM) study of Pd corroded SiC. The reaction of Pd with different types of SiC at typical HTGR operating temperatures was examined. In addition the high temperature mobility of palladium silicides within polycrystalline SiC was investigated. The results indicated corrosion of the SiC by Pd in all cases studied. The corrosion leads to the formation of palladium silicides within the SiC, with the predominant phase found being Pd 2 Si. Evidence for the preferential corrosion and penetration of Pd along grain boundaries in polycrystalline SiC was found. The penetration and transport, without significant corrosion, of palladium silicides into polycrystalline SiC along grain boundaries was also observed. Implications of the findings with reference to the use of Tri Isotropic particles in HTGRs will be discussed.

  6. Growth and sedimentation of fine particles produced in aqueous solutions of palladium sulfate and palladium sulfate-silver sulfate induced by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Hatada, Motoyoshi; Jonah, C.D.

    1994-10-01

    It is known that palladium and palladium-silver fine particles were formed from deaerated aqueous solutions of palladium sulfate and palladium sulfate-silver sulfate induced by gamma-ray irradiation. Changes in particle size and with amount of particles in the solution with time during and after irradiation were studied using dynamic light scattering technique and UV spectrophotometer. The particles formed from palladium sulfate solution are found to be water-filled bulky particles of diameter of 200 nm, which grow by mutual coagulation even after irradiation was terminated. Average density depends on concentration of palladium ion in the solution and dose, and the lowest density was about 2 g/cm 3 for particles of 200 nm obtained from 0.06 mM solution by 2.4 kGy irradiation. The average density of the particles obtained from palladium sulfate-silver sulfate solutions was smaller than those obtained for the corresponding palladium sulfate solutions. Supersonic agitation destroyed coagulated precipitates to form fine particles, but did not form clusters of a few atoms. (author)

  7. Flexible palladium-based H2 sensor with fast response and low leakage detection by nanoimprint lithography.

    Science.gov (United States)

    Lim, Su Hui; Radha, Boya; Chan, Jie Yong; Saifullah, Mohammad S M; Kulkarni, Giridhar U; Ho, Ghim Wei

    2013-08-14

    Flexible palladium-based H2 sensors have a great potential in advanced sensing applications, as they offer advantages such as light weight, space conservation, and mechanical durability. Despite these advantages, the paucity of such sensors is due to the fact that they are difficult to fabricate while maintaining excellent sensing performance. Here, we demonstrate, using direct nanoimprint lithography of palladium, the fabrication of a flexible, durable, and fast responsive H2 sensor that is capable of detecting H2 gas concentration as low as 50 ppm. High resolution and high throughput patterning of palladium gratings over a 2 cm × 1 cm area on a rigid substrate was achieved by heat-treating nanoimprinted palladium benzyl mercaptide at 250 °C for 1 h. The flexible and robust H2 sensing device was fabricated by subsequent transfer nanoimprinting of these gratings into a polycarbonate film at its glass transition temperature. This technique produces flexible H2 sensors with improved durability, sensitivity, and response time in comparison to palladium thin films. At ambient pressure and temperature, the device showed a fast response time of 18 s at a H2 concentration of 3500 ppm. At 50 ppm concentration, the response time was found to be 57 s. The flexibility of the sensor does not appear to compromise its performance.

  8. A light water excess heat reaction suggests that cold fusion may be alkali-hydrogen fusion

    International Nuclear Information System (INIS)

    Bush, R.T.

    1992-01-01

    This paper reports that Mills and Kneizys presented data in support of a light water excess heat reaction obtained with an electrolytic cell highly reminiscent of the Fleischmann-Pons cold fusion cell. The claim of Mills and Kneizys that their excess heat reaction can be explained on the basis of a novel chemistry, which supposedly also explains cold fusion, is rejected in favor of their reaction being, instead, a light water cold fusion reaction. It is the first known light water cold fusion reaction to exhibit excess heat, it may serve as a prototype to expand our understanding of cold fusion. From this new reactions are deduced, including those common to past cold fusion studies. This broader pattern of nuclear reactions is typically seen to involve a fusion of the nuclides of the alkali atoms with the simplest of the alkali-type nuclides, namely, protons, deuterons, and tritons. Thus, the term alkali-hydrogen fusion seems appropriate for this new type of reaction with three subclasses: alkali-hydrogen fusion, alkali-deuterium fusion, and alkali-tritium fusion. A new three-dimensional transmission resonance model (TRM) is sketched. Finally, preliminary experimental evidence in support of the hypothesis of a light water nuclear reaction and alkali-hydrogen fusion is reported. Evidence is presented that appears to strongly implicate the transmission resonance phenomenon of the new TRM

  9. Palladium transport in SiC

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, E.J., E-mail: jolivier@nmmu.ac.za [Centre for High Resolution Transmission Electron Microscopy, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Neethling, J.H. [Centre for High Resolution Transmission Electron Microscopy, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer We investigate the reaction of Pd with SiC at typical HTGR operating temperatures. Black-Right-Pointing-Pointer The high temperature mobility of palladium silicides within polycrystalline SiC was studied. Black-Right-Pointing-Pointer Corrosion of SiC by Pd was seen in all cases. Black-Right-Pointing-Pointer The preferential corrosion and penetration of Pd along grain boundaries in SiC was found. Black-Right-Pointing-Pointer The penetration and transport of palladium silicides in SiC along grain boundaries was found. - Abstract: This paper reports on a transmission electron microscopy (TEM) and scanning electron microscopy (SEM) study of Pd corroded SiC. The reaction of Pd with different types of SiC at typical HTGR operating temperatures was examined. In addition the high temperature mobility of palladium silicides within polycrystalline SiC was investigated. The results indicated corrosion of the SiC by Pd in all cases studied. The corrosion leads to the formation of palladium silicides within the SiC, with the predominant phase found being Pd{sub 2}Si. Evidence for the preferential corrosion and penetration of Pd along grain boundaries in polycrystalline SiC was found. The penetration and transport, without significant corrosion, of palladium silicides into polycrystalline SiC along grain boundaries was also observed. Implications of the findings with reference to the use of Tri Isotropic particles in HTGRs will be discussed.

  10. The kinetics of removal of heat-induced excess nuclear protein

    International Nuclear Information System (INIS)

    Roti, J.L.R.; Uygur, N.; Higashikubo, R.

    1984-01-01

    To investigate the role of protein content, temperature and heating time in the removal of heat-induced excess protein associated with the isolated nucleus, the kinetics of protein removal was monitored for 6 to 8 hours following exposure to 7 hyperthermic protocols. Four of these (47 0 C-7.5 min., 46 0 C-15 min., 45 0 C-30 min., and 44 0 C-60 min.) resulted in a nuclear protein content approximately twice that of nuclei from unheated cells (2.05 +- .14) following heat exposure. Three protocols (45 0 C-15 min., 44 0 C-30 min. and 43 0 C-60 min.) resulted in a nuclear protein content approximately 1.6 times normal (1.63 +- .12). If nuclear protein content were the only determinant in the recovery rate, then the same half time for nuclear protein removal would be expected within each group of protocols. Rate constants for nuclear protein removal were obtained by regression analysis. The half-time for nuclear protein removal increased with decreasing temperature and increasing heating time for the same nuclear protein content. This result suggests that the heating time and temperature are more of a determinant in the removal kinetics than protein content alone. Extended kinetics of recovery (to 36 hours) showed incomplete recovery and a secondary increase in protein associated with the isolated nucleus. These results were due to cell-cycle rearrangement (G/sub 2/ block) and unbalanced growth

  11. Unexpectedly high uptake of palladium by bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Lakatos, J. [Research Lab. for Mining Chemistry, Hungarian Academy of Sciences, Miskolc-Egyetemvaros (Hungary); Brown, S.D.; Snape, C.E. [Univ. of Strathclyde, Dept. of Pure and Applied Chemistry, Glasgow (United Kingdom)

    1997-12-31

    The uptake of palladium as a conversion catalyst onto coals of different rank was investigated. Palladium fixation occurs by a different mode to that for alkaline earth and first row transition metals. Therefore, the dispersion of relatively high concentration of palladium by an ion sorption process is even possible for bituminous coals. (orig.)

  12. Excess heat from kraft pulp mills: Trade-offs between internal and external use in the case of Sweden-Part 2: Results for future energy market scenarios

    International Nuclear Information System (INIS)

    Joensson, Johanna; Svensson, Inger-Lise; Berntsson, Thore; Moshfegh, Bahram

    2008-01-01

    In this paper the trade-off between internal and external use of excess heat from a kraft pulp mill is investigated for four different future energy market scenarios. The work follows the methodology described in Svensson et al. [2008. Excess heat from kraft pulp mills: trade-offs between internal and external use in the case of Sweden-Part 1: methodology. Energy Policy, submitted for publication], where a systematic approach is proposed for investigating the potential for profitable excess heat cooperation. The trade-off is analyzed by economic optimization of an energy system model consisting of a pulp mill and an energy company (ECO). In the model, investments can be made, which increase the system's energy efficiency by utilization of the mill's excess heat, as well as investments that increase the electricity production. The results show that the trade-off depends on energy market prices, the district heating demand and the type of existing heat production. From an economic point of view, external use of the excess heat is preferred for all investigated energy market scenarios if the mill is studied together with an ECO with a small heat load. For the cases with medium or large district heating loads, the optimal use of excess heat varies with the energy market price scenarios. However, from a CO 2 emissions perspective, external use is preferred, giving the largest reduction of global emissions in most cases

  13. : Recyclable, ligand free palladium(II) catalyst for Heck reaction

    Indian Academy of Sciences (India)

    well as heterogeneous palladium catalysts, generated from either palladium(0) compounds or palladium(II) acetate or chloride salts.6 Several ligands such as phosphines, phoshites, carbenes, thioethers have been successfully employed for this reaction.7 However, homogeneous catalysis results in problems of recovery.

  14. Palladium allergy in relation to dentistry

    NARCIS (Netherlands)

    Muris, J.

    2015-01-01

    Palladium is a metal that is used as alloying metal for dental crowns and bridges. This thesis focusses on the possible impact of oral exposure to this metal on the immune system, and allergy in particular. An alternative skin test allergen for diagnosing palladium allergy is introduced: (di)sodium

  15. MONTANA PALLADIUM RESEARCH INITIATIVE

    Energy Technology Data Exchange (ETDEWEB)

    Peters, John; McCloskey, Jay; Douglas, Trevor; Young, Mark; Snyder, Stuart; Gurney, Brian

    2012-05-09

    Project Objective: The overarching objective of the Montana Palladium Research Initiative is to perform scientific research on the properties and uses of palladium in the context of the U.S. Department of Energy's Hydrogen, Fuel Cells and Infrastructure Technologies Program. The purpose of the research will be to explore possible palladium as an alternative to platinum in hydrogen-economy applications. To achieve this objective, the Initiatives activities will focus on several cutting-edge research approaches across a range of disciplines, including metallurgy, biomimetics, instrumentation development, and systems analysis. Background: Platinum-group elements (PGEs) play significant roles in processing hydrogen, an element that shows high potential to address this need in the U.S. and the world for inexpensive, reliable, clean energy. Platinum, however, is a very expensive component of current and planned systems, so less-expensive alternatives that have similar physical properties are being sought. To this end, several tasks have been defined under the rubric of the Montana Palladium Research Iniative. This broad swath of activities will allow progress on several fronts. The membrane-related activities of Task 1 employs state-of-the-art and leading-edge technologies to develop new, ceramic-substrate metallic membranes for the production of high-purity hydrogen, and develop techniques for the production of thin, defect-free platinum group element catalytic membranes for energy production and pollution control. The biomimetic work in Task 2 explores the use of substrate-attached hydrogen-producing enzymes and the encapsulation of palladium in virion-based protein coats to determine their utility for distributed hydrogen production. Task 3 work involves developing laser-induced breakdown spectroscopy (LIBS) as a real-time, in situ diagnostic technique to characterize PGEs nanoparticles for process monitoring and control. The systems engineering work in task 4

  16. Investigation of radiation-chemical behaviour of divalent palladium in perchloric acid solutions

    International Nuclear Information System (INIS)

    Vladimirova, M.V.; Kalinina, S.V.

    1988-01-01

    Gamma-radiolysis of divalent palladium in perchloric acid solutions is studied. Absorption spectra of intermediate palladium compounds formed in the irradiated solution are taken. The analysis of literature data as well as comparative analysis of the absorption spectra obtained under irradiation of palladium (2) perchloric acid solutions with absorption spectra of palladium chlorocomplexes allows to suppose that the mentioned compounds are chlorocomplexes of palladium (2) of different composition depending on HClO 4 concentration in the initial solution and absorbed radiation dose. Radiation-chemical reduction of palladium (2) up to metal is stated to take place in the whole studied range of initial concentrations of components of the system and dose rates. Kinetic dependences of metallic palladium formation are obtained. Values of radiation-chemical yields of metallic palladium formation depending on the initial concentrations of palladium (2) and perchloric acid are given. A mechanism of radiolytic reduction of palladium (2) in the investigated system is suggested based on the experimental data, and a theoretical value of the radiation-chemical yield of palladium (2) reduction being in a good agreement with experimentally found values is calculated

  17. Recovery of Elemental Palladium by Shewanella putrefaciens

    Science.gov (United States)

    Akasaka, S.; Xia, X.; Sawada, K.; Enokida, Y.; Yamamoto, I.; Ohnuki, T.

    2006-12-01

    Microbial reduction of metals plays an important role in environmental behavior and provides a technique for the recovery of metals from industrial wastewater. Recently, demand for platinum group metals (PGMs) increases by their catalytic properties. The extreme rarity of PGMs have led to a growing interest in their recovery. Palladium, one of PGMs, has different oxidation states of Pd(II) and Pd(0). The oxidized form of Pd(II) is soluble, while the reduced form of Pd(0) is insoluble. In this study, microbial reduction of palladium by Fe(III)- reducing bacterium, Shewanella putrefaceins was conducted. This bacterium is known to be capable of reducing metals, such as Mn(IV), U(VI), or Tc(VII) with organic C or H2 as an electron donor. In order to investigate the potential of S. putrefaciens to reduce Pd(II) in solution, resting cells or heat-killed cells were suspended under anaerobic conditions with lactate or H2 as an electron donor. The cells of S. putrefaciens (NBRC3908) were grown in aerobic medium, harvested by centrifugation, and then washed with 25 mmol/dm3 HEPES and 100 mmol/dm3 NaCl (HEPES-NaCl) solution (pH 7.0). The heat-killed cells were autoclaved for 20 min at 121 degrees C. The cell suspension (21.5 mg in dry weight) was resuspended in the HEPES-NaCl solution which contained 1.0 mmol/dm3 Na2PdCl4 (Wako Pure chemical Industries, Ltd). The suspensions were bubbled with N2 for 15 min before 10 mmol/dm3 lactate or 4.8 v/v% H2 was added. The suspensions were then incubated at 30 degrees C. Redox potential (Eh) and pH of the solutions were measured in an inert glove box with Ar gas. Concentration of Pd(II) was measured by Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). Deposited Pd and cells were analyzed by X-ray powder diffraction (XRD) and Scanning Electron Microscope (SEM) with Energy-Dispersive Spectroscopy (EDS). Approximately 86% of Pd(II) of the initial concentration was removed from solution by the resting cells within 24 h when

  18. Palladium Nanoparticle Hydrogen Sensor

    Directory of Open Access Journals (Sweden)

    I. Pavlovsky

    2006-12-01

    Full Text Available An innovative hydrogen sensor based on palladium (Pd nanoparticle networks is described in the article. Made by Applied Nanotech Inc. sensor has a fast response time, in the range of seconds, which is increased at 80 °C due to higher hydrogen diffusion rates into the palladium lattice. The low detection limit of the sensor is 10 ppm of H2, and the high limit is 40,000 ppm. This is 100% of a lowest flammability level of hydrogen. This range of sensitivities complies with the requirements that one would expect for a reliable hydrogen sensor.

  19. Development of second generation gold-supported palladium material with low-leaching and recyclable characteristics in aromatic amination.

    Science.gov (United States)

    Al-Amin, Mohammad; Arai, Satoshi; Hoshiya, Naoyoki; Honma, Tetsuo; Tamenori, Yusuke; Sato, Takatoshi; Yokoyama, Mami; Ishii, Akira; Takeuchi, Masashi; Maruko, Tomohiro; Shuto, Satoshi; Arisawa, Mitsuhiro

    2013-08-02

    An improved process for the preparation of sulfur-modified gold-supported palladium material [SAPd, second generation] is presented. The developed preparation method is safer and generates less heat (aqueous Na2S2O8 and H2SO4) for sulfur fixation on a gold surface, and it is superior to the previous method of preparing SAPd (first generation), which requires the use of the more heat-generating and dangerous piranha solution (concentrated H2SO4 and 35% H2O2) in the sulfur fixation step. This safer and improved preparation method is particularly important for the mass production of SAPd (second generation) for which the catalytic activity was examined in ligand-free Buchwald-Hartwig cross-coupling reactions. The catalytic activities were the same between the first and second generation SAPds in aromatic aminations, but the lower palladium leaching properties and safer preparative method of second generation SAPd are a significant improvement over the first generation SAPd.

  20. Isomerization of 2-butene-1,4-diol in aqueous solutions catalyzed by palladium(II) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Kalabin, S.M.; Novikov, N.A.; Belov, A.P.

    1989-02-01

    The authors studied the isomerization of 2-butene-1,4-diol into 3-butene-1,2-diol at 18-25/degree/C. The concentrations of the diol and PdCl/sub 2/ were (1.0-5.0) /times/ 10/sup /minus/2/ mole/liter at 5-10-fold excess amounts of HCl and NaCl. These additives were used because of their inhibiting action on the oxidation of olefinic compounds. 3-Butene-1,2-diol was identified by /sup 1/H NMR method directly in the reaction solutions in which the reaction solutions in which the reactions in D/sub 2/O were carried out. It was found that palladium(II) complexes catalyze the isomerization of 2-butene-1,4-diol into 3-butene-1,2-diol. A mechanism is proposed for the reaction, which includes the intermediate formation of /eta//sup 3/-allyl complex of palladium with a coordinated hydroxyl group.

  1. Excess Molar Volume,Viscosity and Heat Capacity for the Mixture of 1,2—Propanediol—Water at Different Temperatures

    Institute of Scientific and Technical Information of China (English)

    杨长生; 马沛生; 唐多强; 靳凤民

    2003-01-01

    Experimental densities,viscosities and heat capacities at different emperatures were presented over the entire mole fraction range for the binary mixture of 1,2-propanediol and water,Density values were used in the determination of excess molar volumes,VE,At the same time,the excess viscosity was in vestigated,The values of VE and ηE were fitted to the Redlich-kister equation.Good agreement was observed,The excess volumes are negative over the entire range of composition.They show an U-shaped-concentration dependence and decrease in abolute values with increase of temperature,Values of ηE are negative over the entire range of the composition,and has a trend very similar to that of VE ,The analysis shows that at any temperature the specific heat of mixture is a linear function of the composition as x1>20%,All the extended lines intersect at one point.An empirical equation is obtained to calculate the specific heat to mixture at any composition and temperature in the experimental range.

  2. Atomistic simulation of helium bubble nucleation in palladium

    Energy Technology Data Exchange (ETDEWEB)

    Wang Liang [Department of Applied Physics, Hunan University, Changsha 410082 (China); Hu, Wangyu [Department of Applied Physics, Hunan University, Changsha 410082 (China)], E-mail: wangyuhu2001cn@yahoo.com.cn; Xiao Shifang [Department of Applied Physics, Hunan University, Changsha 410082 (China)], E-mail: sfxiao@yahoo.com.cn; Yang Jianyu [Department of Maths and Physics, Hunan Institute of Engineering, Xiangtan 411104 (China); Deng Huiqiu [Department of Applied Physics, Hunan University, Changsha 410082 (China)

    2009-09-15

    A palladium crystal has been constructed with 11808 atoms. 55 helium atoms occupied the octahedral position of palladium crystal are introduced and retained in a spherical region. Molecular dynamic simulations are performed in a constant temperature and constant volume ensemble (NVT) with temperature controlled by Nose-Hoover thermostat. The interactions between palladium atoms are described with modified analytic embedded atom method (MAEAM), the interactions between palladium atom and helium atom are in the form of Morse potential, and the interactions between helium atoms are in the form of L-J potential function. With the analysis of the radial distribution function (RDF) and microstructure, it reveals that some of helium atoms form a series of clusters with different size, and the nucleation core is random at low temperature, and which is the embryo of helium bubble. Increasing temperature can accelerate the process of bubble nucleation, and the clusters will aggregate and coalesce into a bigger one in which there are no palladium atoms, and it is considered as a helium bubble.

  3. Detecting Airborne Mercury by Use of Palladium Chloride

    Science.gov (United States)

    Ryan, Margaret; Shevade, Abhijit; Kisor, Adam; Homer, Margie; Jewell, April; Manatt, Kenneth; Torres, Julia; Soler, Jessica; Taylor, Charles

    2009-01-01

    Palladium chloride films have been found to be useful as alternatives to the gold films heretofore used to detect airborne elemental mercury at concentrations of the order of parts per billion (ppb). Somewhat more specifically, when suitably prepared palladium chloride films are exposed to parts-per-billion or larger concentrations of airborne mercury, their electrical resistances change by amounts large enough to be easily measurable. Because airborne mercury adversely affects health, it is desirable to be able to detect it with high sensitivity, especially in enclosed environments in which there is a risk of leakage of mercury from lamps or other equipment. The detection of mercury by use of gold films involves the formation of gold/mercury amalgam. Gold films offer adequate sensitivity for detection of airborne mercury and could easily be integrated into an electronic-nose system designed to operate in the temperature range of 23 to 28 C. Unfortunately, in order to regenerate a gold-film mercury sensor, one must heat it to a temperature of 200 C for several minutes in clean flowing air. In preparation for an experiment to demonstrate the present sensor concept, palladium chloride was deposited from an aqueous solution onto sets of gold electrodes and sintered in air to form a film. Then while using the gold electrodes to measure the electrical resistance of the films, the films were exposed, at a temperature of 25 C, to humidified air containing mercury at various concentrations from 0 to 35 ppb (see figure). The results of this and other experiments have been interpreted as signifying that sensors of this type can detect mercury in room-temperature air at concentrations of at least 2.5 ppb and can readily be regenerated at temperatures <40 C.

  4. Practical, economical, and eco-friendly starch-supported palladium catalyst for Suzuki coupling reactions.

    Science.gov (United States)

    Baran, Talat

    2017-06-15

    In catalytic systems, the support materials need to be both eco friendly and low cost as well as having high thermal and chemical stability. In this paper, a novel starch supported palladium catalyst, which had these outstanding properties, was designed and its catalytic activity was evaluated in a Suzuki coupling reaction under microwave heating with solvent-free and mild reaction conditions. The starch supported catalyst gave remarkable reaction yields after only 5min as a result of the coupling reaction of the phenyl boronic acid with 23 different substrates, which are bearing aril bromide, iodide, and chloride. The longevity of the catalyst was also investigated, and the catalyst could be reused for 10 runs. The starch supported Pd(II) catalyst yielded remarkable TON (up to 25,000) and TOF (up to 312,500) values by using a simple, fast and eco-friendly method. In addition, the catalytic performance of the catalyst was tested against different commercial palladium catalysts, and the green starch supported catalyst had excellent selectivity. The catalytic tests showed that the novel starch based palladium catalyst proved to be an economical and practical catalyst for the synthesis of biaryl compounds. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Growth of nanoparticles in hydrogen-implanted palladium subsurfaces

    International Nuclear Information System (INIS)

    Okuyama, F.

    2010-01-01

    Solid particles with nanometric dimensions are shown to grow in the opened subsurface of a polycrystalline palladium (Pd) hydrogen-implanted at around 500 C. The particles are Pd in main composition and densely grown on sloping walls of fissured grain boundaries or cracks. The average grain size increases from deeper to shallow regions, suggesting that a negative temperature gradient toward the surface existed along the crack walls. The nanoparticles are certain to arise from the condensation of Pd vapors on the walls, forcing us to assume that hydrogen atoms implanted in an overpopulation heated their implantation zone so strongly as to vaporize Pd. (orig.)

  6. Growth of nanoparticles in hydrogen-implanted palladium subsurfaces

    Energy Technology Data Exchange (ETDEWEB)

    Okuyama, F. [Nagoya Institute of Technology, Graduate School of Engineering, Nagoya (Japan)

    2010-07-15

    Solid particles with nanometric dimensions are shown to grow in the opened subsurface of a polycrystalline palladium (Pd) hydrogen-implanted at around 500 C. The particles are Pd in main composition and densely grown on sloping walls of fissured grain boundaries or cracks. The average grain size increases from deeper to shallow regions, suggesting that a negative temperature gradient toward the surface existed along the crack walls. The nanoparticles are certain to arise from the condensation of Pd vapors on the walls, forcing us to assume that hydrogen atoms implanted in an overpopulation heated their implantation zone so strongly as to vaporize Pd. (orig.)

  7. Quantifying the adverse effect of excessive heat on children: An elevated risk of hand, foot and mouth disease in hot days.

    Science.gov (United States)

    Zhang, Wangjian; Du, Zhicheng; Zhang, Dingmei; Yu, Shicheng; Hao, Yuantao

    2016-01-15

    Hand, foot and mouth disease (HFMD) is a common childhood infection and has become a major public health issue in China. Considerable research has focused on the role of meteorological factors such as temperature and relative humidity in HFMD development. However, no studies have specifically quantified the impact of another major environmental agent, excessive heat, on HFMD. The current study was designed to help address this research gap. Case-based HFMD surveillance data and daily meteorological data collected between 2010 and 2012 was obtained from China CDC and the National Meteorological Information Center, respectively. Distributed lag nonlinear models were applied to assess the impact of excessive heat on HFMD and its variability across social-economic status and age groups. After controlling the effects of several potential confounders, the commonly hot days were found to positively affect the HFMD burdens with the relative risk (RR) peaking at around 6 days of lag. The RR of HFMD in the Pearl-River Delta Region was generally higher and persisted longer than that in the remaining developing areas. Regarding the inter-age group discrepancy, children aged 3-6 years old had the highest risk of HFMD under conditions of excessive heat whereas those greater than 6 years old had the lowest. The lag structure of the impact of the extremely hot days was quite similar to that of the commonly hot days, although the relative effect of these two kinds of conditions of excessive heat might vary across regions. This study indicated significantly facilitating effects of excessive heat on HFMD especially among those aged 3-6 and from developed areas. Results from the current study were particularly practical and important for developing area-and-age-targeted control programs in the context of climate change and urbanization. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Hydrogen Production via Steam Reforming of Ethyl Alcohol over Palladium/Indium Oxide Catalyst

    Directory of Open Access Journals (Sweden)

    Tetsuo Umegaki

    2009-01-01

    Full Text Available We report the synergetic effect between palladium and indium oxide on hydrogen production in the steam reforming reaction of ethyl alcohol. The palladium/indium oxide catalyst shows higher hydrogen production rate than indium oxide and palladium. Palladium/indium oxide affords ketonization of ethyl alcohol with negligible by-product carbon monoxide, while indium oxide mainly affords dehydration of ethyl alcohol, and palladium affords decomposition of ethyl alcohol with large amount of by-product carbon monoxide. The catalytic feature of palladium/indium oxide can be ascribed to the formation of palladium-indium intermetallic component during the reaction as confirmed by X-ray diffraction and X-ray photoelectron spectroscopic measurements.

  9. Fabrication of palladium-based microelectronic devices by microcontact printing

    International Nuclear Information System (INIS)

    Wolfe, Daniel B.; Love, J. Christopher; Paul, Kateri E.; Chabinyc, Michael L.; Whitesides, George M.

    2002-01-01

    This letter demonstrates the patterning of thin films of metallic palladium by microcontact printing (μCP) of octadecanethiol, and the use of the patterned films in the fabrication of a functional sensor. This technique was also used to prepare templates of palladium for the electroless deposition of copper. The resistivity of the palladium and copper microstructures was 13.8 and 2.8 μΩ cm, respectively; these values are approximately 40% larger than the values for the pure bulk metals. Palladium patterned into serpentine wires using μCP functioned as a hydrogen sensor with sensitivity of 0.03 vol % H 2 in N 2 , and a response time of ∼10 s (at room temperature)

  10. On the nature of the excess heat capacity of mixing

    Science.gov (United States)

    Benisek, Artur; Dachs, Edgar

    2011-03-01

    The excess vibrational entropy (Δ S {vib/ex}) of several silicate solid solutions are found to be linearly correlated with the differences in end-member volumes (Δ V i ) and end-member bulk moduli (Δκ i ). If a substitution produces both, larger and elastically stiffer polyhedra, then the substituted ion will find itself in a strong enlarged structure. The frequency of its vibration is decreased because of the increase in bond lengths. Lowering of frequencies produces larger heat capacities, which give rise to positive excess vibrational entropies. If a substitution produces larger but elastically softer polyhedra, then increase and decrease of mean bond lengths may be similar in magnitude and their effect on the vibrational entropy tends to be compensated. The empirical relationship between Δ S {vib/ex}, Δ V i and Δκ i , as described by Δ S {vib/ex} = (Δ V i + mΔκ i ) f, was calibrated on six silicate solid solutions (analbite-sanidine, pyrope-grossular, forsterite-fayalite, analbite-anorthite, anorthite-sanidine, CaTs-diopside) yielding m = 0.0246 and f = 2.926. It allows the prediction of Δ S {vib/ex} behaviour of a solid solution based on its volume and bulk moduli end-member data.

  11. Silver-Palladium Surfaces Inhibit Biofilm Formation

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Schroll, Casper; Hilbert, Lisbeth Rischel

    2009-01-01

    Undesired biofilm formation is a major concern in many areas. In the present study, we investigated biofilm-inhibiting properties of a silver-palladium surface that kills bacteria by generating microelectric fields and electrochemical redox processes. For evaluation of the biofilm inhibition...... efficacy and study of the biofilm inhibition mechanism, the silver-sensitive Escherichia coli J53 and the silver-resistant E. coli J53[pMG101] strains were used as model organisms, and batch and flow chamber setups were used as model systems. In the case of the silver-sensitive strain, the silver......-palladium surfaces killed the bacteria and prevented biofilm formation under conditions of low or high bacterial load. In the case of the silver-resistant strain, the silver-palladium surfaces killed surface-associated bacteria and prevented biofilm formation under conditions of low bacterial load, whereas under...

  12. The solubility of palladium(II) bis-dimethylglyoximate

    International Nuclear Information System (INIS)

    Maghzian, R.

    1978-01-01

    The solubility of palladium(II) bis-dimethylglyoximate in different solutions has been determined. Values obtained for the solubility of the palladium complex are tabulated. The solubility is the lowest in water, ammonium acetate and a 25% acetone-water mixture. It is highest in dilute HCl and acetone but precipitation from aqueous acetone should be satisfactory for most purposes if the acetone content of the solvent is roughly less than 50% by volume. The solubility in dilute HCl reflects the concern by previous workers for losses in precipitation from mineral acid. In general, however, the losses are unlikely to be significant unless the quantity of palladium to be precipitated and weighed is small. (T.G.)

  13. Determination of palladium by flame photometry

    International Nuclear Information System (INIS)

    Parellada Bellod, R.

    1964-01-01

    A study on the determination of palladium by lame photometry, fixing the most convent experimental conditions and using solvents to increase the emission of this elements is carried out. Among the organic solvents, acetone has been found the most efficient. The interferences produced by anions and cations have also been studied and an analytical method is related, in which lines of calibration of 0 to 100 ppm palladium re used. (Author) 7 refs

  14. Adsorption of palladium ions by modified carbons from rice husks

    International Nuclear Information System (INIS)

    Mostafa, M.R.

    1994-01-01

    Steam activated carbon of high surface area does not show palladium ions adsorption. Treatment of this carbon with HF acid increases to a great extent the gas adsorption capacity expressed as nitrogen surface area as well as the adsorption capacity of palladium ions from aqueous solution. HHB was loaded in different amounts on to these carbons. The acid sites represent the active fraction of the surface on which the adsorption palladium ions proceed. The uptake of palladium ions by HHB treated carbons is related to the total number of HHB molecules loaded on the carbon surface. (author)

  15. Development of Separation Materials Containing Palladium for Hydrogen Isotopes Separation

    International Nuclear Information System (INIS)

    Deng Xiaojun; Luo Deli; Qian Xiaojing

    2010-01-01

    Displacement chromatography (DC) is a ascendant technique for hydrogen isotopes separation. The performance of separation materials is a key factor to determine the separation effect of DC. At present,kinds of materials are researched, including palladium materials and non-palladium materials. It is hardly replaceable because of its excellent separation performance, although palladium is expensive. The theory of hydrogen isotopes separation using DC was introduced at a brief manner, while several palladium separation materials were expatiated in detail(Pd/K, Pd-Al 2 O 3 , Pd-Pt alloy). Development direction of separation materials for DC was forecasted elementarily. (authors)

  16. Dendritic surface morphology of palladium hydride produced by electrolytic deposition

    International Nuclear Information System (INIS)

    Julin, Peng; Bursill, L.A.

    1990-01-01

    Conventional and high-resolution electron microscopic studies of electrolytically-deposited palladium hydride reveal a fascinating variety of surface profile morphologies. The observations provide direct information concerning the surface structure of palladium electrodes and the mechanism of electrolytic deposition of palladium black. Both classical electrochemical mechanisms and recent 'modified diffusion-limited-aggregation' computer simulations are discussed in comparison with the experimental results. 13 refs., 9 figs

  17. Fexofenadine Suppresses Delayed-Type Hypersensitivity in the Murine Model of Palladium Allergy

    Directory of Open Access Journals (Sweden)

    Ryota Matsubara

    2017-06-01

    Full Text Available Palladium is frequently used in dental materials, and sometimes causes metal allergy. It has been suggested that the immune response by palladium-specific T cells may be responsible for the pathogenesis of delayed-type hypersensitivity in study of palladium allergic model mice. In the clinical setting, glucocorticoids and antihistamine drugs are commonly used for treatment of contact dermatitis. However, the precise mechanism of immune suppression in palladium allergy remains unknown. We investigated inhibition of the immune response in palladium allergic mice by administration of prednisolone as a glucocorticoid and fexofenadine hydrochloride as an antihistamine. Compared with glucocorticoids, fexofenadine hydrochloride significantly suppressed the number of T cells by interfering with the development of antigen-presenting cells from the sensitization phase. Our results suggest that antihistamine has a beneficial effect on the treatment of palladium allergy compared to glucocorticoids.

  18. Palladium-Catalyzed Cross-Coupling Reactions of Perfluoro Organic Compounds

    Directory of Open Access Journals (Sweden)

    Masato Ohashi

    2014-09-01

    Full Text Available In this review, we summarize our recent development of palladium(0-catalyzed cross-coupling reactions of perfluoro organic compounds with organometallic reagents. The oxidative addition of a C–F bond of tetrafluoroethylene (TFE to palladium(0 was promoted by the addition of lithium iodide, affording a trifluorovinyl palladium(II iodide. Based on this finding, the first palladium-catalyzed cross-coupling reaction of TFE with diarylzinc was developed in the presence of lithium iodide, affording α,β,β-trifluorostyrene derivatives in excellent yield. This coupling reaction was expanded to the novel Pd(0/PR3-catalyzed cross-coupling reaction of TFE with arylboronates. In this reaction, the trifluorovinyl palladium(II fluoride was a key reaction intermediate that required neither an extraneous base to enhance the reactivity of organoboronates nor a Lewis acid additive to promote the oxidative addition of a C–F bond. In addition, our strategy utilizing the synergetic effect of Pd(0 and lithium iodide could be applied to the C–F bond cleavage of unreactive hexafluorobenzene (C6F6, leading to the first Pd(0-catalyzed cross-coupling reaction of C6F6 with diarylzinc compounds.

  19. Sputtering induced surface composition changes in copper-palladium alloys

    International Nuclear Information System (INIS)

    Sundararaman, M.; Sharma, S.K.; Kumar, L.; Krishnan, R.

    1981-01-01

    It has been observed that, in general, surface composition is different from bulk composition in multicomponent materials as a result of ion beam sputtering. This compositional difference arises from factors like preferential sputtering, radiation induced concentration gradients and the knock-in effect. In the present work, changes in the surface composition of copper-palladium alloys, brought about by argon ion sputtering, have been studied using Auger electron spectroscopy. Argon ion energy has been varied from 500 eV to 5 keV. Enrichment of palladium has been observed in the sputter-altered layer. The palladium enrichment at the surface has been found to be higher for 500 eV argon ion sputtering compared with argon ion sputtering at higher energies. Above 500 eV, the surface composition has been observed to remain the same irrespective of the sputter ion energy for each alloy composition. The bulk composition ratio of palladium to copper has been found to be linearly related to the sputter altered surface composition ratio of palladium to copper. These results are discussed on the basis of recent theories of alloy sputtering. (orig.)

  20. Effects of palladium coatings on oxygen sensors of titanium dioxide thin films

    International Nuclear Information System (INIS)

    Castaneda, L.

    2007-01-01

    Titanium dioxide (TiO 2 -anatase phase) thin films were deposited by the ultrasonic spray pyrolysis technique employing titanium (IV) oxide acetylacetonate (TiO(acac) 2 ) dissolved in pure methanol as a source material. In order to prepare oxygen sensors, TiO 2 thin films were deposited on interdigitated gold electrodes with contacted alumina substrates. Palladium (Pd) coatings were carried out by vacuum thermal evaporation through a metallic mask. The effect of the surface additive (Pd) on the response of the thin film TiO 2 oxygen sensors was monitored in a mixture with zero-grade air. The electrical characterization (monitoring of the electrical surface resistance with the operation temperature) of the sensors in an atmosphere of oxygen (diluted in zero-grade air) was performed in a vacuum chamber (10 -6 Torr), where the gas pressure can be controlled. The films sensitivity was estimated by the following relation: s=R gas -R 0 /R 0 . The response time of the sensor is defined to be the time needed to reach a 0.9R 0 value when the oxygen excess is removed. The gas-sensing properties of TiO 2 sensors in an atmosphere of 10 4 ppm of oxygen were measured between 100 and 450 deg. C. Experimental results obtained using palladium as a surface additive show that the sensitivity reaches a stationary value of 1.18 for O 2 concentration of 100ppm in zero-grade air at 300 deg. C, which is as high as those reported for oxygen sensors prepared with more expensive and complex techniques. The role and activity of palladium coatings incorporated on solid-state oxygen sensors are determined by their chemical state, aggregation form and interaction with the metal-oxide semiconductor

  1. Controlling the excess heat from oxy-combustion of coal by blending with biomass

    Energy Technology Data Exchange (ETDEWEB)

    Haykiri-Acma, H.; Turan, A.Z.; Yaman, S.; Kucukbayrak, S. [Istanbul Technical University, Chemical and Metallurgical Engineering Faculty, Chemical Engineering Department, 34469, Maslak, Istanbul (Turkey)

    2010-11-15

    Two different biomass species such as sunflower seed shell and hazelnut shell were blended with Soma-Denis lignite to determine the effects of co-combustion on the thermal reactivity and the burnout of the lignite sample. For this purpose, Thermogravimetric Analysis and Differential Scanning Calorimetry techniques were applied from ambient to 900 C with a heating rate of 40 C/min under dry air and pure oxygen conditions. It was found that the thermal reactivities of the biomass materials and the lignite are highly different from each other under each oxidizing medium. On the other hand, the presence of biomass in the burning medium led to important influences not only on the burnout levels but also on the heat flows. The heat flow from the burning of lignite increased fivefold when the oxidizing medium was altered from dry air to pure oxygen. But, in case of co-combustion under oxygen, the excess heat arising from combustion of lignite could be reduced and this may be helpful to control the temperature of the combustion chamber. Based on this, co-combustion of coal/biomass blends under oxygen may be suggested as an alternative method to the ''Carbon Dioxide Recycle Method'' encountered in the oxyfuel combustion systems. (author)

  2. Enhancing the performance of single-chambered microbial fuel cell using manganese/palladium and zirconium/palladium composite cathode catalysts.

    Science.gov (United States)

    Jadhav, Dipak A; Deshpande, Parag A; Ghangrekar, Makarand M

    2017-08-01

    Application of ZrO 2 , MnO 2 , palladium, palladium-substituted-zirconium oxide (Zr 0.98 Pd 0.02 O 2 ) and palladium-substituted-manganese oxide (Mn 0.98 Pd 0.02 O 2 ) cathode catalysts in a single-chambered microbial fuel cell (MFC) was explored. The highest power generation (1.28W/m 3 ) was achieved in MFC with Mn 0.98 Pd 0.02 O 2 catalyst, which was higher than that with MnO 2 (0.58W/m 3 ) alone; whereas, MFC having Zr 0.98 Pd 0.02 O 2 catalyzed cathode and non-catalyzed cathode produced powers of 1.02 and 0.23W/m 3 , respectively. Also, low-cost zirconium-palladium-composite showed better catalytic activity and capacitance over ZrO 2 with 20A/m 3 current production and demonstrated its suitability for MFC applications. Cyclic voltammetry analyses showed higher well-defined redox peaks in composite catalysts (Mn/Zr-Pd-C) over other catalyzed MFCs containing MnO 2 or ZrO 2 . Electrochemical behaviour of composite catalysts on cathode showed higher availability of adsorption sites for oxygen reduction and, hence, enhanced the rate of cathodic reactions. Thus, Mn/Zr-Pd-C-based composite catalysts exhibited superior cathodic performance and could be proposed as alternatives to costly Pd-catalyst for field applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Facile synthesis of bacitracin-templated palladium nanoparticles with superior electrocatalytic activity

    Science.gov (United States)

    Li, Yanji; Wang, Zi; Li, Xiaoling; Yin, Tian; Bian, Kexin; Gao, Faming; Gao, Dawei

    2017-02-01

    Palladium nanomaterials have attracted great attention on the development of electrocatalysts for fuel cells. Herein, we depicted a novel strategy in the synthesis of palladium nanoparticles with superior electrocatalytic activity. The new approach, based on the self-assembly of bacitracin biotemplate and palladium salt for the preparation of bacitracin-palladium nanoparticles (Bac-PdNPs), was simple, low-cost, and green. The complex, composed by a series of spherical Bac-PdNPs with a diameter of 70 nm, exhibited a chain-liked morphology in TEM and a face-centered cubic crystal structure in X-Ray diffraction and selected area electron diffraction. The palladium nanoparticles were mono-dispersed and stable in aqueous solution as shown in TEM and zeta potential. Most importantly, compared to the commercial palladium on carbon (Pd/C) catalyst (8.02 m2 g-1), the Bac-PdNPs showed a larger electrochemically active surface area (47.57 m2 g-1), which endowed the products an excellent electrocatalytic activity for ethanol oxidation in alkaline medium. The strategy in synthesis of Bac-PdNPs via biotemplate approach might light up new ideas in anode catalysts for direct ethanol fuel cells.

  4. Porous palladium coated conducting polymer nanoparticles for ultrasensitive hydrogen sensors

    Science.gov (United States)

    Lee, Jun Seop; Kim, Sung Gun; Cho, Sunghun; Jang, Jyongsik

    2015-12-01

    Hydrogen, a clean-burning fuel, is of key importance to various industrial applications, including fuel cells and in the aerospace and automotive industries. However, hydrogen gas is odorless, colorless, and highly flammable; thus appropriate safety protocol implementation and monitoring are essential. Highly sensitive hydrogen leak detection and surveillance sensor systems are needed; additionally, the ability to maintain uniformity through repetitive hydrogen sensing is becoming increasingly important. In this report, we detail the fabrication of porous palladium coated conducting polymer (3-carboxylate polypyrrole) nanoparticles (Pd@CPPys) to detect hydrogen gas. The Pd@CPPys are produced by means of facile alkyl functionalization and chemical reduction of a pristine 3-carboxylate polypyrrole nanoparticle-contained palladium precursor (PdCl2) solution. The resulting Pd@CPPy-based sensor electrode exhibits ultrahigh sensitivity (0.1 ppm) and stability toward hydrogen gas at room temperature due to the palladium sensing layer.Hydrogen, a clean-burning fuel, is of key importance to various industrial applications, including fuel cells and in the aerospace and automotive industries. However, hydrogen gas is odorless, colorless, and highly flammable; thus appropriate safety protocol implementation and monitoring are essential. Highly sensitive hydrogen leak detection and surveillance sensor systems are needed; additionally, the ability to maintain uniformity through repetitive hydrogen sensing is becoming increasingly important. In this report, we detail the fabrication of porous palladium coated conducting polymer (3-carboxylate polypyrrole) nanoparticles (Pd@CPPys) to detect hydrogen gas. The Pd@CPPys are produced by means of facile alkyl functionalization and chemical reduction of a pristine 3-carboxylate polypyrrole nanoparticle-contained palladium precursor (PdCl2) solution. The resulting Pd@CPPy-based sensor electrode exhibits ultrahigh sensitivity (0.1 ppm

  5. Thermosonic wire bonding of IC devices using palladium wire

    International Nuclear Information System (INIS)

    Shze, J.H.; Poh, M.T.; Tan, R.M.

    1996-01-01

    The feasibility of replacing gold wire by palladium wire in thermosonic wire bonding of CMOS and bipolar devices are studied in terms of the manufacturability, physical, electrical and assembly performance. The results that palladium wire is a viable option for bonding the bipolar devices but not the CMOS devices

  6. Synthesis of palladium nanoparticles with leaf extract of Chrysophyllum cainito (Star apple) and their applications as efficient catalyst for C-C coupling and reduction reactions

    Science.gov (United States)

    Majumdar, Rakhi; Tantayanon, Supawan; Bag, Braja Gopal

    2017-10-01

    A simple green chemical method for the one-step synthesis of palladium nanoparticles (PdNPs) has been described by reducing palladium (II) chloride with the leaf extract of Chrysophyllum cainito in aqueous medium. The synthesis of the palladium nanoparticles completed within 2-3 h at room temperature, whereas on heat treatment (70-80 °C), the synthesis of colloidal PdNPs completed almost instantly. The stabilized PdNPs have been characterized in detail by spectroscopic, electron microscopic and light scattering measurements. The synthesized PdNPs have been utilized as a green catalyst for C-C coupling reactions under aerobic and phosphine-free conditions in aqueous medium. In addition, the synthesized PdNPs have also been utilized as a catalyst for a very efficient sodium borohydride reduction of 3- and 4-nitrophenols. The synthesized PdNPs can retain their catalytic activity for several months.

  7. Absorption of hydrogen by vanadium-palladium alloys

    International Nuclear Information System (INIS)

    Artman, D.; Lynch, J.F.; Flanagan, T.B.

    1976-01-01

    Pressure composition isotherms (273-373 K) have been determined for the absorption of hydrogen by a series of six palladium alloys (f.c.c) in the composition range from 1 to 8 at.% vanadium. At a given hydrogen content, the equilibrium hydrogen pressure progressively increases with vanadium content. Thermodynamic parameters for the absorption of hydrogen are reported at infinite dilution of hydrogen and for the formation of the nonstoichiometric hydride from the hydrogen-saturated alloy. The relative, partial molar enthalpy of solution of hydrogen at infinite dilution increases slightly with vanadium content. The presence of vanadium, which absorbs hydrogen itself in its normal b.c.c. structure, greatly inhibits the ability of palladium to absorb hydrogen. For example, the isobaric solubility of hydrogen (1 atm, 298K) decreases from H/Pd=0.7 (palladium) to 0.024 (V(6%)-Pd). The lattice expansion due to the presence of interstitial hydrogen has been determined by X-ray diffraction. From these data it can be concluded that the formation of two non-stoichiometric hydride phases does not occur at vanadium contents greater that 5 at.% (298 K). Electrical resistance has been measured as a function of the hydrogen content of the alloys. The electrical resistance increases more markedly with hydrogen content for these alloys than for any of the palladium alloys previously examined. (Auth.)

  8. The utilization of excess wind-electric power from stock water pumping systems to heat a sector of the stock tank

    Energy Technology Data Exchange (ETDEWEB)

    Nydahl, J.E.; Carlson, B.O. [Univ. of Wyoming, Laramie, WY (United States)

    1996-12-31

    On the high plains, a wind-electric stock water pumping system produces a significant amount of excess power over the winter months due to intense winds and the decreased water consumption by cattle. The University of Wyoming is developing a multi-tasking system to utilize this excess energy to resistively heat a small sector of the stock tank at its demonstration/experimental site. This paper outlines the detailed heat transfer analysis that predicted drinking water temperature and icing conditions. It also outlines the optimization criteria and the power produced by the Bergey 1500 wind electric system. Results show that heating a smaller insulated tank inserted into the larger tank would raise the drinking water temperature by a maximum of 6.7 {degrees}C and eliminate icing conditions. The returns associated with the additional cattle weight gain, as a result of the consumption of warmer water, showed that system modification costs would be recovered the first year. 12 refs., 11 figs., 2 tabs.

  9. Chemical recovery of palladium-103 from irradiated silver target

    International Nuclear Information System (INIS)

    Lapshina, E.V.; Kokhanyuk, V.M.; Zhuikov, B.L.; Myasoedova, G.V.; Zakhartchenko, E.A.; Phillips, D.R.; Jamriska, D.J.

    2003-01-01

    The goal of this work is to develop an extraction method of no-carrier-added palladium-103 from silver. Metallic silver targets may be irradiated by protons with energy of 60-200 MeV or more to generate palladium-103 simultaneously with other radioactive isotopes of rhodium, ruthenium, technetium, palladium and silver. According to the dependence experimental production yield of Pd-103 and isotopes of other elements in thick silver target vs. Proton energy the most suitable energy for maximum yield of Pd-103 and minimum yield of other elements is from about 100 to about 140 MeV. Activity of radionuclides produced in silver target depends from many factors (target thickness, irradiation time, etc.). Two methods of Pd-103 recovering from irradiated silver target are considered in this work: (1) Silver target is dissolved in nitric acid followed by silver precipitation in the form of silver chloride by addition of HCl. The solution containing Pd, Rh and other radionuclides is passed through the layer of fibrous sorbent POLYORGS-15n. Then the sorbent is washed and Pd is desorbed by hot 12 M hydrochloric acid; (2) Silver target is dissolved in nitric acid followed by passing of the obtained solution (2 M HNO 3 ) through a disk set of complex forming sorbent POLYORGS-33n. Under these conditions palladium is sorbed by the sorbent while silver, rhodium, ruthenium and technetium are passed through the sorbent. Then the sorbent is washed with 2M nitric acid, and Pd is desorbed by 12 M hydrochloric acid. Extraction of palladium is occurred during the formation of palladium complex with a chelate sorbent specific to palladium in acidic solutions. Such a sorbent makes possible separation of palladium from accompanying radionuclides such as rhodium, ruthenium and technetium. The polymeric complex-forming sorbent of fibrous structure with the groups of 3(5)-methylpyrazole (POLYORGS-15) is used. The distinctive feature of the sorbents in the form of fibrous 'filled' material is

  10. Nano-palladium is a cellular catalyst for in vivo chemistry

    Science.gov (United States)

    Miller, Miles A.; Askevold, Bjorn; Mikula, Hannes; Kohler, Rainer H.; Pirovich, David; Weissleder, Ralph

    2017-07-01

    Palladium catalysts have been widely adopted for organic synthesis and diverse industrial applications given their efficacy and safety, yet their biological in vivo use has been limited to date. Here we show that nanoencapsulated palladium is an effective means to target and treat disease through in vivo catalysis. Palladium nanoparticles (Pd-NPs) were created by screening different Pd compounds and then encapsulating bis[tri(2-furyl)phosphine]palladium(II) dichloride in a biocompatible poly(lactic-co-glycolic acid)-b-polyethyleneglycol platform. Using mouse models of cancer, the NPs efficiently accumulated in tumours, where the Pd-NP activated different model prodrugs. Longitudinal studies confirmed that prodrug activation by Pd-NP inhibits tumour growth, extends survival in tumour-bearing mice and mitigates toxicity compared to standard doxorubicin formulations. Thus, here we demonstrate safe and efficacious in vivo catalytic activity of a Pd compound in mammals.

  11. Excessive Heat Events and National Security: Building Resilience based on Early Warning Systems

    Science.gov (United States)

    Vintzileos, A.

    2017-12-01

    Excessive heat events (EHE) affect security of Nations in multiple direct and indirect ways. EHE are the top cause for morbidity/mortality associated to any atmospheric extremes. Higher energy consumption used for cooling can lead to black-outs and social disorder. EHE affect the food supply chain reducing crop yield and increasing the probability of food contamination during delivery and storage. Distribution of goods during EHE can be severely disrupted due to mechanical failure of transportation equipment. EHE during athletic events e.g., marathons, may result to a high number of casualties. Finally, EHE may also affect military planning by e.g. reducing hours of exercise and by altering combat gear. Early warning systems for EHE allow for building resilience. In this paper we first define EHE as at least two consecutive heat days; a heat day is defined as a day with a maximum heat index with probability of occurrence that exceeds a certain threshold. We then use retrospective forecasts performed with a multitude of operational models and show that it is feasible to forecast EHE at forecast lead of week-2 and week-3 over the contiguous United States. We finally introduce an improved definition of EHE based on an intensity index and investigate forecast skill of the predictive system in the tropics and subtropics.

  12. Report on the development/comprehensive research of new hydrogen energy demonstrative technology; Shinsuiso energy jissho gijutsu kaihatsu sogo kenkyu hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    In this project, the excess heat phenomenon caused by electrolyzing heavy water using palladium metal, etc. as electrode was captured as `new hydrogen energy.` To make a possibility of being as a future energy source clear, the abnormal heating phenomenon was verified. By elucidating the mechanism, the paper aimed at quantitatively controlling the heat generation. The R and D period was four years from fiscal 1993, and the details of the research are about the excess heat measuring test, material analysis/development tests, test on detection of reaction products, information collection/arrangement, international research cooperation. As a result of the research, a part of the excess heat measurement was surely able to be reproduced. However, when a confirmation experiment on the excess heat was conducted by another more positive method under the same conditions, it was found that the excess heat quantity was not the absolute excess heat quantity exceeding the measuring sensitivity/errors of the system. Supposing the excess heat of 0.1W order is generated in nuclear reaction, any of reaction products should be detected in a considerable quantity. However, no reaction products were not detected. 42 refs., 241 figs., 55 tabs.

  13. Palladium configuration dependence of hydrogen detection sensitivity based on graphene FET for breath analysis

    Science.gov (United States)

    Sakamoto, Yuri; Uemura, Kohei; Ikuta, Takashi; Maehashi, Kenzo

    2018-04-01

    We have succeeded in fabricating a hydrogen gas sensor based on palladium-modified graphene field-effect transistors (FETs). The negative-voltage shift in the transfer characteristics was observed with exposure to hydrogen gas, which was explained by the change in work function. The hydrogen concentration dependence of the voltage shift was investigated using graphene FETs with palladium deposited by three different evaporation processes. The results indicate that the hydrogen detection sensitivity of the palladium-modified graphene FETs is strongly dependent on the palladium configuration. Therefore, the palladium-modified graphene FET is a candidate for breath analysis.

  14. Surface topography of a palladium cathode after electrolysis in heavy water

    International Nuclear Information System (INIS)

    Silver, D.S.; Dash, J.; Keefe, P.S.

    1993-01-01

    Electrolysis was performed with a palladium cathode and an electrolyte containing both hydrogen and deuterium ions. The cathode bends toward the anode during this process. Examination of both the concave and the convex surfaces with the scanning electron microscope, scanning tunneling microscope, and atomic force microscope shows unusual surface characteristics. Rimmed craters with faceted crystals inside and multitextural surfaces were observed on an electrolyzed palladium cathode but not on palladium that has not been electrolyzed. 9 refs., 9 figs

  15. Toward Efficient Palladium-Catalyzed Allylic C-H Alkylation

    DEFF Research Database (Denmark)

    Jensen, Thomas; Fristrup, Peter

    2009-01-01

    Recent breakthroughs have proved that direct palladium (II)-catalyzed allylic C-H alkylation can be achieved. This new procedure shows that the inherent requirement for a leaving group in the Tsuji-Trost palladium-catalyzed allylic alkylation can be lifted. These initial reports hold great promise...... for the development of allylic C-H alkylation into a widely applicable methodology, thus providing a means to enhance synthetic efficiency in these reactions....

  16. Making use of the energy potential of hybrid heat production from excess green electricity; Energetische Potenziale hybrider Waermeerzeugung aus Oekostrom-Ueberangeboten nutzen

    Energy Technology Data Exchange (ETDEWEB)

    Volkmann, Lukas; Riegebauer, Philipp; Oesterwind, Dieter [Zentrum fuer Innovative Energiesysteme (ZIES), Duesseldorf (Germany); Muench, Wolfram [Energie Baden-Wuerttemberg AG (EnBW), Karlsruhe (Germany)

    2013-06-15

    Convert electricity to heat? Integration with the heat market opens up the option of using excess yields of electricity from renewable resources for hybrid provision of room heating, warm water and process steam. Environmental protection associations such as BUND e.V. (Association for Environmental Protection and Nature Conservation) are demanding a ban on conventional electric heating, but at the same time acknowledge the potential of plants that can flexibly switch between generating heat from fossil fuels and from electricity. Time for a paradigm change.

  17. Palladium-Catalysed Coupling Reactions

    NARCIS (Netherlands)

    de Vries, Johannes G.; Beller, M; Blaser, HU

    2012-01-01

    Palladium-catalysed coupling reactions have gained importance as a tool for the production of pharmaceutical intermediates and to a lesser extent also for the production of agrochemicals, flavours and fragrances, and monomers for polymers. In this review only these cases are discussed where it seems

  18. Heat Roadmap Europe: Identifying strategic heat synergy regions

    International Nuclear Information System (INIS)

    Persson, U.; Möller, B.; Werner, S.

    2014-01-01

    This study presents a methodology to assess annual excess heat volumes from fuel combustion activities in energy and industry sector facilities based on carbon dioxide emission data. The aim is to determine regional balances of excess heat relative heat demands for all third level administrative regions in the European Union (EU) and to identify strategic regions suitable for large-scale implementation of district heating. The approach is motivated since the efficiency of current supply structures to meet building heat demands, mainly characterised by direct use of primary energy sources, is low and improvable. District heating is conceived as an urban supply side energy efficiency measure employable to enhance energy system efficiency by increased excess heat recoveries; hereby reducing primary energy demands by fuel substitution. However, the importance of heat has long been underestimated in EU decarbonisation strategies and local heat synergies have often been overlooked in energy models used for such scenarios. Study results indicate that 46% of all excess heat in EU27, corresponding to 31% of total building heat demands, is located within identified strategic regions. Still, a realisation of these rich opportunities will require higher recognition of the heat sector in future EU energy policy. - Highlights: • EU27 energy and industry sector heat recycling resources are mapped and quantified. • Target regions for large-scale implementation of district heating are identified. • 46% of total EU27 excess heat volume is seized in 63 strategic heat synergy regions. • Large urban zones have lead roles to play in transition to sustainability in Europe. • Higher recognition of heat sector is needed in future EU energy policy for realisation

  19. Ion flotation of rhodium(III) and palladium(II) with anionic surfactants.

    Science.gov (United States)

    He, X C

    1991-03-01

    The ion flotation of rhodium(III) and palladium(II) with some anionic surfactants has been investigated. Two flotation procedures are proposed for the separation of some platinum metals, based on differences in the kinetic properties of the chloro-complexes of rhodium(III), palladium(II) and platinum(IV). The first involves the selective flotation of Rh(H(2)O)(3+)(6) from PdCl(2-)(4) and PtCl(2-)(6) in dilute hydrochloric acid with sodium dodecylbenzenesulfonate (SDBS). After precipitation of the hydroxide and redissolution in dilute acid, the Rh(III) is converted into Rh(H(2)O)(3+)(6), Pd(II) and Pt(IV) remaining as PdCl(2-)(4) and PtCl(2-)(6) respectively, and separation is achieved by floating the Rh(H(2)O)(3+)(6) with SDBS. The second is for separation of Pd(II). Prior to flotation, the solution of PdCl(2-)(4) and PtCl(2-)(6) is heated with ammonium acetate to convert PdCl(2-)(4) into Pd(NH(3))(2+)(4). The chloro-complex of Pt(IV) is unaffected. The complex cation, Pd(NH(3))(2+)(4), is then selectively floated with SDBS. The procedures are fast, simple and do not require expensive reagents and apparatus.

  20. Palladium-Catalyzed Atom-Transfer Radical Cyclization at Remote Unactivated C(sp3 )-H Sites: Hydrogen-Atom Transfer of Hybrid Vinyl Palladium Radical Intermediates.

    Science.gov (United States)

    Ratushnyy, Maxim; Parasram, Marvin; Wang, Yang; Gevorgyan, Vladimir

    2018-03-01

    A novel mild, visible-light-induced palladium-catalyzed hydrogen atom translocation/atom-transfer radical cyclization (HAT/ATRC) cascade has been developed. This protocol involves a 1,5-HAT process of previously unknown hybrid vinyl palladium radical intermediates, thus leading to iodomethyl carbo- and heterocyclic structures. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Thermodynamics of the hybrid interaction of hydrogen with palladium nanoparticles

    NARCIS (Netherlands)

    Griessen, R.P.; Strohfeldt, N.; Giessen, H.

    2015-01-01

    Palladium-hydrogen is a prototypical metal-hydrogen system. It is therefore not at all surprising that a lot of attention has been devoted to the absorption and desorption of hydrogen in nanosized palladium particles. Several seminal articles on the interaction of H with Pd nanocubes and

  2. Wheat yield loss attributable to heat waves, drought and water excess at the global, national and subnational scales

    Science.gov (United States)

    Zampieri, M.; Ceglar, A.; Dentener, F.; Toreti, A.

    2017-06-01

    Heat waves and drought are often considered the most damaging climatic stressors for wheat. In this study, we characterize and attribute the effects of these climate extremes on wheat yield anomalies (at global and national scales) from 1980 to 2010. Using a combination of up-to-date heat wave and drought indexes (the latter capturing both excessively dry and wet conditions), we have developed a composite indicator that is able to capture the spatio-temporal characteristics of the underlying physical processes in the different agro-climatic regions of the world. At the global level, our diagnostic explains a significant portion (more than 40%) of the inter-annual production variability. By quantifying the contribution of national yield anomalies to global fluctuations, we have found that just two concurrent yield anomalies affecting the larger producers of the world could be responsible for more than half of the global annual fluctuations. The relative importance of heat stress and drought in determining the yield anomalies depends on the region. Moreover, in contrast to common perception, water excess affects wheat production more than drought in several countries. We have also performed the same analysis at the subnational level for France, which is the largest wheat producer of the European Union, and home to a range of climatic zones. Large subnational variability of inter-annual wheat yield is mostly captured by the heat and water stress indicators, consistently with the country-level result.

  3. Pore surface fractal analysis of palladium-alumina ceramic membrane using Frenkel-Halsey-Hill (FHH) model.

    Science.gov (United States)

    Ahmad, A L; Mustafa, N N N

    2006-09-15

    The alumina ceramic membrane has been modified by the addition of palladium in order to improve the H(2) permeability and selectivity. Palladium-alumina ceramic membrane was prepared via a sol-gel method and subjected to thermal treatment in the temperature range 500-1100 degrees C. Fractal analysis from nitrogen adsorption isotherm is used to study the pore surface roughness of palladium-alumina ceramic membrane with different chemical composition (nitric acid, PVA and palladium) and calcinations process in terms of surface fractal dimension, D. Frenkel-Halsey-Hill (FHH) model was used to determine the D value of palladium-alumina membrane. Following FHH model, the D value of palladium-alumina membrane increased as the calcinations temperature increased from 500 to 700 degrees C but decreased after calcined at 900 and 1100 degrees C. With increasing palladium concentration from 0.5 g Pd/100 ml H(2)O to 2 g Pd/100 ml H(2)O, D value of membrane decreased, indicating to the smoother surface. Addition of higher amount of PVA and palladium reduced the surface fractal of the membrane due to the heterogeneous distribution of pores. However, the D value increased when nitric acid concentration was increased from 1 to 15 M. The effect of calcinations temperature, PVA ratio, palladium and acid concentration on membrane surface area, pore size and pore distribution also studied.

  4. District heating in sequential energy supply

    International Nuclear Information System (INIS)

    Persson, Urban; Werner, Sven

    2012-01-01

    Highlights: ► European excess heat recovery and utilisation by district heat distribution. ► Heat recovery in district heating systems – a structural energy efficiency measure. ► Introduction of new theoretical concepts to express excess heat recovery. ► Fourfold potential for excess heat utilisation in EU27 compared to current levels. ► Large scale excess heat recovery – a collaborative challenge for future Europe. -- Abstract: Increased recovery of excess heat from thermal power generation and industrial processes has great potential to reduce primary energy demands in EU27. In this study, current excess heat utilisation levels by means of district heat distribution are assessed and expressed by concepts such as recovery efficiency, heat recovery rate, and heat utilisation rate. For two chosen excess heat activities, current average EU27 heat recovery levels are compared to currently best Member State practices, whereby future potentials of European excess heat recovery and utilisation are estimated. The principle of sequential energy supply is elaborated to capture the conceptual idea of excess heat recovery in district heating systems as a structural and organisational energy efficiency measure. The general conditions discussed concerning expansion of heat recovery into district heating systems include infrastructure investments in district heating networks, collaboration agreements, maintained value chains, policy support, world market energy prices, allocation of synergy benefits, and local initiatives. The main conclusion from this study is that a future fourfold increase of current EU27 excess heat utilisation by means of district heat distribution to residential and service sectors is conceived as plausible if applying best Member State practice. This estimation is higher than the threefold increase with respect to direct feasible distribution costs estimated by the same authors in a previous study. Hence, no direct barriers appear with

  5. Ageing of palladium tritide: mechanical characterization, helium state and modelling

    International Nuclear Information System (INIS)

    Segard, M.

    2010-01-01

    Palladium is commonly used for the storage of tritium (the hydrogen radioactive isotope), since it forms a low-equilibrium-pressure and reversible tritide. Tritium decay into helium-3 is responsible for the ageing of the tritide, leading to the apparition of helium-3 bubbles for instance. Both experimental and theoretical aspects of this phenomenon are studied here.Previous works on ageing modelling led to two main models, dealing with:- Helium-3 bubbles nucleation (using a cellular automaton), - Bubbles growth (using continuum mechanics).These models were quite efficient, but their use was limited by the lack of input data and fitting experimental parameters.To get through these limitations, this work has consisted in studying the most relevant experimental data to improve the modelling of the palladium tritide ageing.The first part of this work was focused on the assessment of the mechanical properties of the palladium tritide (yield strength, ultimate strength, mechanical behaviour). They were deduced from the in situ tensile tests performed on palladium hydride and deuteride. In the second part, ageing characterization was undertaken, mainly focusing on: - Bubbles observations in palladium tritide using transmission electron microscopy, - Internal bubble pressure measurements using nuclear magnetic resonance, - Macroscopic swelling measurements using pycno-metry.The present work has led to significant progress in ageing understanding and has brought very valuable improvements to the modelling of such a phenomenon. (author) [fr

  6. Palladium nanoparticle anchored polyphosphazene nanotubes ...

    Indian Academy of Sciences (India)

    607–610. c Indian Academy of Sciences. Palladium ... 2Department of Chemistry, APA College of Arts and Culture, Palani, Tamil Nadu 624 601, India. 3Department of .... K Dinakaran acknowledges the financial support from. Department of ...

  7. Research report of FY 1996 on development of new hydrogen energy demonstration technology. 1. FY 1996 results; 1996 nendo kenkyu hokokusho. Shinsuiso energy jissho gijutsu kaihatsu (1996 nendo jisshibun)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    The purpose of this project is to clarify the possibility of new hydrogen energy as a future energy source. The new hydrogen energy is obtained from the excess heat generation phenomenon through the electrolysis of heavy water using palladium metal as an electrode. The excess heat regeneration tests have been successively conducted using two kinds of electrolytic cells. As a result, the excess heat generation measured by one electrolytic cell in FY 1996 has been confirmed in about 35% of repeatability under the same condition. On the other hand, the excess heat over the measuring accuracy was not measured using two kinds of absolute heating value measuring systems. The electrolytic cell, by which the excess heat was measured, was used for confirming the absolute heating value as keeping its condition. When tests were conducted using the developed system, it was found that the absolute heating value can not be detected. Then, verification tests are currently conducted for determining the cause. Moreover, in order to clarify the basic characteristics of materials required for the regeneration of the excess heat generation phenomenon, observation and analysis of the materials were performed before and after the excess heat measurement. Thus, the cause of difference was revealed. 3 refs., 98 figs., 24 tabs.

  8. Mechanism of the palladium-catalyzed hydrothiolation of alkynes to thioethers: a DFT study.

    Science.gov (United States)

    Zhang, Xing-hui; Geng, Zhi-yuan; Wang, Ke-tai; Li, Shan-shan

    2014-09-01

    The mechanisms of the palladium-catalyzed hydrothiolation of alkynes with thiols were investigated using density functional theory at the B3LYP/6-31G(d, p) (SDD for Pd) level. Solvent effects on these reactions were explored using the polarizable continuum model (PCM) for the solvent tetrahydrofuran (THF). Markovnikov-type vinyl sulfides or cis-configured anti-Markovnikov-type products were formed by three possible pathways. Our calculation results suggested the following: (1) the first step of the cycle is a proton-transfer process from thiols onto the palladium atom to form a palladium-thiolate intermediate. The palladium-thiolate species is attacked on alkynes to obtain an elimination product, liberating the catalyst. (2) The higher activation energies for the alkyne into the palladium-thiolate bond indicate that this step is the rate-determining step. The Markovnikov-type vinyl sulfide product is favored. However, for the aromatic alkyne, the cis-configured anti-Markovnikov-type product is favored. (3) The activation energy would reduce when thiols are substituted with an aromatic group. Our calculated results are consistent with the experimental observations of Frech and colleagues for the palladium-catalyzed hydrothiolation of alkynes to thiols.

  9. Carbon nanotubes decorated with palladium nanoparticles : Synthesis, characterization, and catalytic activity

    NARCIS (Netherlands)

    Karousis, Nikolaos; Tsotsou, Georgia-Eleni; Evangelista, Fabrizio; Rudolf, Petra; Ragoussis, Nikitas; Tagmatarchis, Nikos

    2008-01-01

    In this article, the in situ preparation of palladium nanoparticles, as mediated by the self-regulated reduction of palladium acetate with the aid of sodium dodecyl sulfate (SDS), followed by subsequent deposition onto single-walled carbon nanotubes and multimalled carbon nanotubes (MWCNTs), is

  10. Microwave-assisted synthesis of palladium nanocubes and nanobars

    International Nuclear Information System (INIS)

    Yu, Yanchun; Zhao, Yanxi; Huang, Tao; Liu, Hanfan

    2010-01-01

    Microwave was employed in the shape-controlled synthesis of palladium nanoparticles. Palladium nanocubes and nanobars with a mean size of about 23.8 nm were readily synthesized with H 2 PdCl 4 as a precursor, tetraethylene glycol (TEG) as both a solvent and a reducing agent in the presence of PVP and CTAB in 80 s under microwave irradiation. The structures of the as-prepared palladium nanoparticles were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and ultraviolet-visible (UV-vis) absorption spectroscopy. The formation of PdBr 4 2- due to the coordination replacement of the ligand Cl - ions in PdCl 4 2- ions by Br - ions in the presence of bromide was responsible for the synthesis of Pd nanocubes and nanobars. In addition, a milder reducing power, a higher viscosity and a stronger affinity of TEG were beneficial to the larger sizes of Pd nanocubes and nanobars.

  11. Oxygen Activated, Palladium Nanoparticle Catalyzed, Ultrafast Cross-Coupling of Organolithium Reagents

    NARCIS (Netherlands)

    Heijnen, Dorus; Tosi, Filippo; Vila, Carlos; Stuart, Marc C. A.; Elsinga, Philip H.; Szymanski, Wiktor; Feringa, Ben L.

    2017-01-01

    The discovery of an ultrafast cross-coupling of alkyland aryllithium reagents with a range of aryl bromides is presented. The essential role of molecular oxygen to form the active palladium catalyst was established; palladium nanoparticles that are highly active in cross-coupling reactions with

  12. Palladium sulphide (PdS) films as a new thermoelectric sulphide compound

    Energy Technology Data Exchange (ETDEWEB)

    Ares, J.R.; Diaz-Chao, P.; Clamagirand, J.; Macia, M.D.; Ferrer, I.J.; Sanchez, C. [Universidad Autonoma de Madrid (Spain). Lab. de Materiales de Interes en Energias Renovables

    2010-07-01

    Palladium sulphide (PdS) films have been prepared by direct sulphuration of 20 nm thick palladium films at different temperatures (200 C < T < 450 C). Sulphurated films exhibit an unique crystalline phase: PdS. Seebeck coefficient and electrical resistivity of these films are between -110 and -150 {mu}V/K and {proportional_to} 0.08 to 0.8 {omega}cm depending on the sulphuration temperature. Negative sign of Seebeck coefficient indicates an n type conduction in all films. Discussion is focused on the influence of atomic ratio between sulphur and palladium as well as impurities arising from the substrate on transport properties. (orig.)

  13. The generalized lewis acid-base titration of palladium and niobium

    Science.gov (United States)

    Cima, M.; Brewer, L.

    1988-12-01

    The high thermodynamic stability of alloys composed of platinum group metals and group IVB and VB metals has been explained by an electronic interaction analogous to the Lewis acid-base concept for nontransition elements. The analogy is further demonstrated by the titration of palladium by addition of niobium. The activity of niobium in solid palladium was measured as a function of concentration by solid-state galvanic cells and study of the ternary oxide phase diagram. The galvanic cells were of the type Pt/NbO2,Nb2O4.8/YDTJNbOy,Nbpd/Pt where the solid electrolyte is yttria-doped thoria (YDT). Ternary phase diagrams for the Pd-Nb-0 and Rh-Nb-0 systems were obtained by characterizing samples equilibrated at 1000 °C. The phase relationships found in the ternary diagrams were also used to derive thermochemical data for the alloys. Thermochemical quantities for other acid-base stabilized alloys such as Nb-Rh, Ti-Pd, and Ti-Rh were also measured. The excess partial molar ΔGxs/R of niobium at infinite dilution was determined to be -31 kilo-Kelvin at 1000 °C, and the AG°JR of formation of a mole of NbPd3.55 is —21 kilo-Kelvin. These results and those for the other systems are used to assess the importance of valence electron configuration, nuclear charge, and crystal field effects in the context of generalized Lewis acid-base theory. It is concluded that both the nuclear charge of the atom and crystal field splitting of the valence orbitals significantly affect the basicity of the platinum group metals.

  14. Method for recovering palladium and technetium values from nuclear fuel reprocessing waste solutions

    Science.gov (United States)

    Horwitz, E. Philip; Delphin, Walter H.

    1979-07-24

    A method for recovering palladium and technetium values from nuclear fuel reprocessing waste solutions containing these and other values by contacting the waste solution with an extractant of tricaprylmethylammonium nitrate in an inert hydrocarbon diluent which extracts the palladium and technetium values from the waste solution. The palladium and technetium values are recovered from the extractant and from any other coextracted values with a strong nitric acid strip solution.

  15. Development of anodic stripping voltametry for the determination of palladium in high level nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Bhardwaj, T. K. [North Carolina State University, Raleigh (United States); Sharma, H. S.; Affarwal, S. K. [Bhabha Atomic Research Centre, Mumbai (India); Jain, P. C. [Meerut College, Meerut (India)

    2012-12-15

    Deposition potential, deposition time, square wave frequency, rotation speed of the rotating disc electrode, and palladium concentration were studied on a Glassy Carbon Electrode (GCE) in 0.01M HCl for the determination of palladium in High Level Nuclear Waste (HLNW) by anodic stripping voltammetry. Experimental conditions were optimized for the determination of palladium at two different, 10-8 and 10-7 M, levels. Error and standard deviation of this method were under 1% for all palladium standard solutions. The developed technique was successfully applied as a subsidiary method for the determination of palladium in simulated high level nuclear waste with very good precision and high accuracy (under 1 % error and standard deviation).

  16. Palladium silicide - a new contact for semiconductor radiation detectors

    International Nuclear Information System (INIS)

    Totterdell, D.H.J.

    1981-11-01

    Silicide layers can be used as low resistance contacts in semiconductor devices. The formation of a metal rich palladium silicide Pd 2 Si is discussed. A palladium film 100A thick is deposited at 300 0 C and the resulting silicide layer used as an ohmic contact in an n + p silicon detector. This rugged contact has electrical characteristics comparable with existing evaporated gold contacts and enables the use of more reproducible bonding techniques. (author)

  17. Palladium alloys for hydrogen diffusion

    International Nuclear Information System (INIS)

    1977-01-01

    A palladium-base alloy with tin and/or a silicon addition and its use in the production of hydrogen from water via a cycle of chemical reactions, of which the decomposition of HI into H 2 and I 2 is the most important, is described

  18. Metal allergen of the 21st century--a review on exposure, epidemiology and clinical manifestations of palladium allergy

    DEFF Research Database (Denmark)

    Faurschou, Annesofie; Menné, Torkil; Johansen, Jeanne D

    2011-01-01

    Consumers are mainly exposed to palladium from jewellery and dental restorations. Palladium contact allergy is nearly always seen together with nickel allergy, as palladium and nickel tend to cross-react. We aimed to analyse the available palladium patch test data and case reports to determine...

  19. Thin film platinum–palladium thermocouples for gas turbine engine applications

    Energy Technology Data Exchange (ETDEWEB)

    Tougas, Ian M.; Gregory, Otto J., E-mail: gregory@egr.uri.edu

    2013-07-31

    Thin film platinum:palladium thermocouples were fabricated on alumina and mullite surfaces using radio frequency sputtering and characterized after high temperature exposure to oxidizing environments. The thermoelectric output, hysteresis, and drift of these sensors were measured at temperatures up to 1100 °C. Auger electron spectroscopy was used to follow the extent of oxidation in each thermocouple leg and interdiffusion at the metallurgical junction. Minimal oxidation of the platinum and palladium thermoelements was observed after high temperature exposure, but considerable dewetting and faceting of the films were observed in scanning electron microscopy. An Arrhenius temperature dependence on the drift rate was observed and later attributed to microstructural changes during thermal cycling. The thin film thermocouples, however, did exhibit excellent stability at 1000 °C with drift rates comparable to commercial type-K wire thermocouples. Based on these results, platinum:palladium thin film thermocouples have considerable potential for use in the hot sections of gas turbine engines. - Highlights: • Stable thin film platinum:palladium thermocouples for gas turbine engines • Little oxidation but significant microstructural changes from thermal cycling • Minimal hysteresis during repeated thermal cycling • Drift comparable to commercial wire thermocouples.

  20. Oxygen isotope exchange on palladium catalysts

    International Nuclear Information System (INIS)

    Kravchuk, L.S.; Beschetvertnaya, T.I.; Novorodskij, V.G.; Novikova, M.G.; Zaretskij, M.V.; Valieva, S.V.

    1983-01-01

    Oxygen heteromolecular isotope exchange on unreduced palladium catalysts, distingushing by metal content is studied. Content of 18 O in gaseous phase is eoual to 46%. Calculations of heteroexchange rates are conducted with decrease of the 18 O in the gaseous phase over solid sample. Method of oxygen thermodesorption has been used to establish that palladium, deposited on γ-Al 2 O 3 during exchange process is in oxidized state; in this case strength of Pd-O bond is determined by content dispersity) of the metal. It is shown that significant increase of exchange rate on the samples with Pd >> 0.5 mass.% content can be induced as by side decomposition reaction of its oxide and corresponding dilution of gaseous mixture by ''light'' oxygen so by possibility of exchange with oxygen of PdO phase

  1. Research report of FY 1996 on development of new hydrogen energy demonstration technology. 2. Results in the extension period of FY 1996; 1996 nendo kenkyu hokokusho. Shinsuiso energy jissho gijutsu kaihatsu (1996 nendo kikan enchobun)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    The purpose of this project is to clarify the possibility of new hydrogen energy as a future energy source. The new hydrogen energy is obtained from the excess heat generation phenomenon through the electrolysis of heavy water using palladium metal as an electrode. The excess heat measurements were conducted through the excess heat confirmation tests using a fuel cell-type electrolytic cell up to November 1997. As a result, it was found that the excess heat measured by the calibration method can not be measured by the flow calorimetric method. In order to investigate the possibility of systematic errors of the both methods, the sensitivity, accuracy and responsibility, and the conditions of the excess heat generation, research activities based on new facts from scientific information and fundamental research supporting projects have been mainly performed. Among these, were performed the excess heat measurement tests by the cataphoresis method, absorption tests by the high-pressure and high-temperature charging method, gas plasma loading, in-situ X-ray detection, and reactant detection tests using Au/Pd/PdO heterogeneous structural body. 5 refs., 59 figs., 9 tabs.

  2. Morphology of one-time coated palladium-alumina composite membrane prepared by sol-gel process and electroless plating technique

    Science.gov (United States)

    Sari, R.; Dewi, R.; Pardi; Hakim, L.; Diana, S.

    2018-03-01

    Palladium coated porous alumina ceramic membrane tube was obtained using a combination of sol-gel process and electroless plating technique. The thickness, structure and composition of palladium-alumina composite membrane were analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and atomic force microscopy (AFM). Palladium particle size was 6.18 to 7.64 nm. Palladium membrane with thickness of approximately 301.5 to 815.1 nm was formed at the outer surface of the alumina layer. EDX data confirmed the formation of palladium-alumina membrane containing 45% of palladium. From this research it shows the combination of sol-gel process and electroless plating technique with one-time coating can produce a homogeneous and smoother palladium nano layer film on alumina substrate.

  3. Demonstration technology development of new hydrogen energy; Shinsuiso energy jissho gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    A phenomenon of excess heat generation through the electrolysis of heavy water using palladium metals as electrode can be recognized as new hydrogen energy. Its mechanism has been investigated for four years since FY 1993. In FY 1993, the New Hydrogen Energy Demonstration Research Center and the New Hydrogen Energy Demonstration Laboratory were organized, and the research was initiated. For the excess heat generation demonstration model tests, two types of electrolysis experimental units were constructed, and the Pd/D-based electrolysis experiments were initiated. For the measurements of excess heat using an open type electrolysis cell, there were rather large errors ranging from -13% to +7%. It is necessary to improve the accuracy. For the measurements using a fuel cell type electrolysis cell, generation of the excess heat ranging from 0% to 6% was observed. For the validity of this, it is required to confirm the long-term stability of calibration and cell components. For the correlation between the increase in absorbing rate and the generation of excess heat, results of 2 to 3% lower were obtained. 28 refs., 89 figs., 26 tabs.

  4. Recovery of nonradioactive palladium and rhodium from high-level radioactive wastes

    International Nuclear Information System (INIS)

    McDuffie, H.F.

    1979-01-01

    A possible method for recovering significant quantities of nonradioactive palladium from fission-product wastes requires essentially complete separation of the fission-product (radioactive) palladium from fission-product ruthenium. After the decay of 106 Ru via 106 Rh to 106 Pd, this nonradioactive palladium is recovered for normal commercial use. The U.S. production of palladium has never been above 1000 kg per year vs consumption of about 46,000 kg per year. Most of the supply comes from Russia and South Africa. It has been estimated that a 400-GW(e) nuclear reactor economy will make available 2000 kg per year of 106 Ru at reactor fuel discharge. A substantial increase might be achieved if plutonium were recycled as fissionable material because of the higher yields of the 106 chain from plutonium. A literature search has uncovered support for three promising approaches to the required separation of palladium from ruthenium: (1) recrystallization from solution in bismuth or in zinc; (2) selective precipitation of a titanium--ruthenium intermetallic compound from bismuth, followed by precipitation of a zinc--palladium intermetallic compound; and (3) dissolution in molten magnesium followed by partitioning between molten magnesium and a molten uranium-5 wt % chromium eutectic at a temperature above 870 0 C. Liquid-liquid extraction appears to be the most promising method from a technological point of view, although intermetallic compound formation is much more interesting chemically. Recovery of some nonradioactive 103 Rh may be possible by liquid-liquid extraction of the fuel before the decay of the 39.8-d 103 Ru has gone substantially to completion. Demonstration of the practicality of these separations will contribute a positive factor to the evaluation of resumption in the United States of nuclear fuel reprocessing and plutonium recycle in light-water-moderated reactors

  5. In situ synthesis of carbon nanotubes decorated with palladium nanoparticles using arc-discharge in solution method

    International Nuclear Information System (INIS)

    Bera, Debasis; Kuiry, Suresh C.; McCutchen, Matthew; Seal, Sudipta; Heinrich, Helge; Slane, Grady C.

    2004-01-01

    A unique, simple, inexpensive, and one-step synthesis route to produce carbon nanotubes (CNTs) decorated with palladium nanoparticles using a simplified dc arc-discharge in solution is reported. Zero-loss energy filtered transmission electron microscopy and scanning transmission electron microscopy confirm the presence of 3 nm palladium nanoparticles. Such palladium nanoparticles form during the reduction of palladium tetra-chloro-square-planar complex. The deconvoluted x-ray photoelectron spectroscopy envelope shows the presence of palladium on the decorated CNTs. The energy dispersive spectroscopy suggests no functionalization of atomic chlorine to the sidewall of the CNTs. The presence of dislodged graphene sheets with wavy morphology supports the formation of CNTs through the 'scroll mechanism'

  6. Electrochemical behavior of fission palladium in 1-butyl-3-methylimidazolium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Jayakumar, M.; Venkatesan, K.A.; Srinivasan, T.G. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2007-08-01

    Electrochemical behavior of palladium (II) chloride in 1-butyl-3-methylimidazolium chloride has been investigated by various electrochemical transient techniques using glassy carbon working electrode at different temperatures (343-373 K). Cyclic voltammogram consisted of a prominent reduction wave at -0.61 V (vs. Pd) due to the reduction of Pd(II) to Pd, and two oxidation waves at -0.26 and 0.31 V. A nucleation loop is observed at -0.53 V. The diffusion coefficient of palladium (II) in bmimCl ({proportional_to}10{sup -7} cm{sup 2}/s) was determined and the energy of activation (63 kJ/mol) was deduced from the cyclic voltammograms at various temperatures. Nucleation and growth of palladium on glassy carbon working electrode has been investigated by chronoamperometry and chronopotentiometry. The growth and decay of chronocurrents measured for palladium deposition has been found to follow the instantaneous nucleation model with three-dimensional growth of nuclei. The surface morphology of the deposit obtained at various applied potentials revealed the formation of dendrites immediately after nucleation and spread in all the directions with time. (author)

  7. Radiochemical neutron activation analysis of high pure palladium and platinum by ion exchange chromatography

    International Nuclear Information System (INIS)

    Sadikov, I.I.; Zinov'ev, V.G.; Sadikova, Z.O.; Salimov, M.I.

    2006-01-01

    Full text: The palladium and platinum are widely used for jewel manufacture because of their beautiful white color. However the most part of these metals are widely adopted in the world as catalysts. Many works on analytical chemistry of platinum group elements published during last years are devoted to determination of platinum and palladium in other materials. There are no articles on analysis technique of the palladium and platinum purity published during last 20 years. Available publications are very old and are published till 70th of the last century, and implement chemical and spectral methods. At the same time, the palladium and platinum are very suitable for NAA. Therefore the purpose of our research was development of high-sensitivity and multielement techniques of radiochemical neutron activation analysis of a high pure palladium and platinum. Research of nuclear characteristics of palladium and platinum has shown that radioactive nuclides with different yields are formed under the reactor neutrons. 109 , 111 , 111m Pd, 109m , 111 Ag, 191 , 197 , 199 Pt, 199 Au are the most important among them. 109Pd separation factor is equal to 1*10 5 at palladium analysis, whereas 197 Pt and 199 Au separation factor is equal to 1*10 4 at the platinum analysis every other day after irradiation. Palladium and platinum can be separated by precipitation, extraction and ion exchange methods. For separation of radioactive nuclide of the matrix elements from the impurity elements we used ion exchange chromatography system Dowex-1x8 - 1 M HNO 3 for palladium and Dowex-1x8 - 0.1 M HNO 3 for platinum. At the HNO 3 acid concentrations variation from 0,1 M to 1 M more then 25 elements have distribution factors less than 1 and 10 elements have distribution factors 5 while matrix elements have distribution factors higher than 100. It allows an effective separation of these elements from palladium and platinum. Optimum sizes of the chromatographic column and the column effluent

  8. Factors affecting the corrosion of SiC layer by fission product palladium

    International Nuclear Information System (INIS)

    Dewita, E.

    2000-01-01

    HTR is one of the advanced nuclear reactors which has inherent safety system, graphite moderated and helium gas cooled. In general, these reactors are designed with the TRISO coated particle consist of four coating layers that are porous pyrolytic carbon (PyC). inner dense PyC (IPyC), silicon carbide (SiC), and outer dense PyC (OPyC). Among the four coating layers, the SiC plays an important role beside in retaining metallic fission products, it also provides mechanical strength to fuel particle. However, results of post irradiation examination indicate that fission product palladium can react with and corrode SiC layer, This assessment is conducted to get the comprehension about resistance of SiC layer on irradiation effects, especially in order to increase the fuel bum-up. The result of this shows that the corrosion of SiC layer by fission product palladium is beside depend on the material characteristics of SiC, and also there are other factors that affect on the SiC layer corrosion. Fuel enrichment, bum-up, and irradiation time effect on the palladium flux in fuel kernel. While, the fuel density, vapour pressure of palladium (the degree depend on the irradiation temperature and kernel composition) effect on palladium migration in fuel particle. (author)

  9. Crystal size effect on the electrochemical oxidation of formate on carbon-supported palladium nanoparticles

    International Nuclear Information System (INIS)

    Santos, Rayana Marcela Izidoro da Silva; Nakazato, Roberto Zenhei; Ciapina, Eduardo Goncalves

    2016-01-01

    Full text: The electrochemical oxidation of formate in alkaline electrolytes has emerged an a promising anodic reaction in the Direct Formate Fuel Cells[1]. Although palladium is considered to be one of the best electro catalyst for the oxidation of formate, important structure-activity relationships are still not understood. In the present work, we investigated the effect of the size of the palladium crystals in the electrochemical oxidation of formate in 0.1 mol L -1 KOH. Carbon-supported palladium nanoparticles (Pd/C) were prepared by chemical reduction of palladium (II) chloride in aqueous media by sodium borohydride in the presence of varying quantities of sodium citrate in the reaction media to obtain metallic crystals with distinct sizes. Analysis of the X-ray diffraction profile revealed the presence of palladium crystals in the range of 6 to 19 nm. Potentiostatic oxidation of formate on the distinct Pd/C samples revealed a volcano-like dependence of the specific activity with the size of the palladium crystals, presenting the highest activity for crystals around 7.5 nm. Reference: [1] A.M. Bartrom, J.L. Haan, The direct formate fuel cell with an alkaline anion exchange membrane, J. Power Sources. 214 (2012) 68-74. (author)

  10. Silver-palladium catalysts for the direct synthesis of hydrogen peroxide

    Science.gov (United States)

    Khan, Zainab; Dummer, Nicholas F.; Edwards, Jennifer K.

    2017-11-01

    A series of bimetallic silver-palladium catalysts supported on titania were prepared by wet impregnation and assessed for the direct synthesis of hydrogen peroxide, and its subsequent side reactions. The addition of silver to a palladium catalyst was found to significantly decrease hydrogen peroxide productivity and hydrogenation, but crucially increase the rate of decomposition. The decomposition product, which is predominantly hydroxyl radicals, can be used to decrease bacterial colonies. The interaction between silver and palladium was characterized using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The results of the TPR and XPS indicated the formation of a silver-palladium alloy. The optimal 1% Ag-4% Pd/TiO2 bimetallic catalyst was able to produce approximately 200 ppm of H2O2 in 30 min. The findings demonstrate that AgPd/TiO2 catalysts are active for the synthesis of hydrogen peroxide and its subsequent decomposition to reactive oxygen species. The catalysts are promising for use in wastewater treatment as they combine the disinfectant properties of silver, hydrogen peroxide production and subsequent decomposition. This article is part of a discussion meeting issue 'Providing sustainable catalytic solutions for a rapidly changing world'.

  11. Migration behavior of palladium in UO2, (3)

    International Nuclear Information System (INIS)

    Yoneyama, Mitsuru; Sato, Seichi; Ohashi, Hiroshi; Ogawa, Toru; Ito, Akinori; Fukuda, Kousaku.

    1992-08-01

    Palladium (Pd) is easily released from UO 2 kernels in HTGR coated fuel particles, and reacts with SiC coating layer. In addition, Pd is one of metallic fission products in irradiation UO 2 , which constitutes in dissoluble residue in reprocessing of LWR fuels. In the present investigation, the migration of palladium in UO 2 was examined by heating diffusion pairs sandwiched Pd foil between UO 2 wafers at 1300 ∼ 1800degC. Experiments were also carried out on affinity of Pd to UP 2 and a formation of U-Pd alloy. Pd was found mainly in the pores of UO 2 . The maximum depth intruded by Pd in fairly large amount was more than 100 μm for UO 2 with 90%TD and 50μm for UO 2 with 95%TD, while the maximum length of open pores was 330 μm for UO 2 with 90%TD, and 50 m for that with 95%TD. Fused Pd wetted UO 2 very much. Pd intruded deeply into UO 2 , especially in the edge of Pd droplet. Furthermore, U was detected either in precipitates or the Pd source with α-Pd phase of U-Pd alloy containing Pd at about 10at%. This fact indicates that Pd highly reacts with UO 2 . From the above results, the transport of Pd in UO 2 was explained by the model of gaseous diffusion through pores in UO 2 , which is retarded by formation of U-Pd alloy. It is also indicated that UPd 3 forms even at the oxygen potential condition of O/U ratio, which is a little higher than 2.00 on the basis of thermodynamic calculation. (author)

  12. The electrocatalytical reduction of m-nitrophenol on palladium nanoparticles modified glassy carbon electrodes

    International Nuclear Information System (INIS)

    Shi Qiaofang; Diao Guowang

    2011-01-01

    Highlights: ► The deposition of palladium on a GC electrode was performed by cyclic voltammetry. ► SEM images showed palladium nanoparticles deposited on a glassy carbon (GC) electrode. ► The Pd/GC electrode can effectively catalyze m-nitrophenol in aqueous media. ► The reduction of m-nitrophenol on the Pd/GC electrode depended on potential and pH. ► XPS spectra of the Pd/GC electrodes demonstrated the presence of palladium. - Abstract: Palladium nanoparticles modified glassy carbon electrodes (Pd/GC) were prepared via the electrodeposition of palladium on a glassy carbon (GC) electrode using cyclic voltammetry in different sweeping potential ranges. The scanning electron microscope images of palladium particles on the GC electrodes indicate that palladium particles with diameters of 20–50 nm were homogeneously dispersed on the GC electrode at the optimal deposition conditions, which can effectively catalyze the reduction of m-nitrophenol in aqueous solutions, but their catalytic activities are strongly related to the deposition conditions of Pd. The X-ray photoelectron spectroscopy spectra of the Pd/GC electrode confirmed that 37.1% Pd was contained in the surface composition of the Pd/GC electrode. The cyclic voltammograms of the Pd/GC electrode in the solution of m-nitrophenol show that the reduction peak of m-nitrophenol shifts towards the more positive potentials, accompanied with an increase in the peak current compared to the bare GC electrode. The electrocatalytic activity of the Pd/GC electrode is affected by pH values of the solution. In addition, the electrolysis of m-nitrophenol under a constant potential indicates that the reduction current of m-nitrophenol on the Pd/GC electrode is approximately 20 times larger than that on the bare GC electrode.

  13. Palladium(II)-Stabilized Pyridine-2-Diazotates: Synthesis, Structural Characterization, and Cytotoxicity Studies.

    Science.gov (United States)

    Tskhovrebov, Alexander G; Vasileva, Anna A; Goddard, Richard; Riedel, Tina; Dyson, Paul J; Mikhaylov, Vladimir N; Serebryanskaya, Tatiyana V; Sorokoumov, Viktor N; Haukka, Matti

    2018-02-05

    Well-defined diazotates are scarce. Here we report the synthesis of unprecedented homoleptic palladium(II) diazotate complexes. The palladium(II)-mediated nitrosylation of 2-aminopyridines with NaNO 2 results in the formation of metal-stabilized diazotates, which were found to be cytotoxic to human ovarian cancer cells.

  14. Temporal trends in human vulnerability to excessive heat

    Science.gov (United States)

    Sheridan, Scott C.; Allen, Michael J.

    2018-04-01

    Over recent decades, studies have examined various morbidity and mortality outcomes associated with heat exposure. This review explores the collective knowledge of the temporal trends of heat on human health, with regard to the hypothesis that humans are less vulnerable to heat events presently than in the past. Using Web of Science and Scopus, the authors identified all peer-reviewed articles that contained keywords on human impact (e.g. mortality, morbidity) and meteorological component (e.g. heat, heatwave). After sorting, a total of 71 articles, both case studies and epidemiological studies, contained explicit assessments of temporal trends in human vulnerability, and thus were used in this review. Most of the studies utilized mortality data, focused on the developed world, and showed a general decrease in heat sensitivity. Factors such as the implementation of a heat warning system, increased awareness, and improved quality of life were cited as contributing factors that led to the decreased impact of heat. Despite the overall recent decreases in heat vulnerability, spatial variability was shown, and differences with respect to health outcomes were also discussed. Several papers noted increases in heat’s impact on human health, particularly when unprecedented conditions occurred. Further, many populations, from outdoor workers to rural residents, in addition to the populations in much of the developing world, have been significantly underrepresented in research to date, and temporal changes in their vulnerability should be assessed in future studies. Moreover, continued monitoring and improvement of heat intervention is needed; with projected changes in the frequency, duration, and intensity of heat events combined with shifts in demographics, heat will remain a major public health issue moving forward.

  15. Interaction between Palladium Nanoparticles and Surface-Modified Carbon Nanotubes: Role of Surface Functionalities

    DEFF Research Database (Denmark)

    Zhang, Bingsen; Shao, Lidong; Zhang, Wei

    2014-01-01

    degrees C. We focus on probing the effects of oxygen and nitrogen-containing functional groups on supported palladium nanoparticles (NPs) in the model catalytic system. The stability of palladium NPs supported on CNTs depends strongly on the surface properties of CNTs. Moreover, the oxygen...... feature, instability, and subtle response of the components upon application of an external field. Herein, we use insitu TEM, electron energy loss spectroscopy, and X-ray photoelectron spectroscopy techniques to record the interaction in palladium on carbon nanotubes (CNTs) from room temperature to 600...

  16. Carbonylation of 1-hexene in the presence of palladium-anion-exchange resin catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Lapidus, A.L.; Pirozhkov, S.D.; Buiya, M.A.; Lunin, A.F.; Karapetyan, L.P.; Saldadze, K.M.

    1986-06-20

    Activated charcoal, silica gel, and zeolites containing palladium are active in the carbonylation of lower olefins by carbon monoxide. In the present work, they studied the carbonylation of 1-hexene in the presence of a series of palladium catalysts containing An-221, An-251, and AN-511 anion-exchange catalysts produced in the USSR as the supports. A catalyst obtained by the deposition of palladium(II) on weakly basic anion-exchange resins displays high efficiency in the carbonylation of 1-hexene with the formation of a nixture of enanthoic and 2-methylcaproic acids.

  17. New Palladium-Catalyzed Approaches to Heterocycles and Carbocycles

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Qinhua [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    The tert-butylimines of o-(1-alkynyl)benzaldehydes and analogous pyridinecarbaldehydes have been cyclized under very mild reaction conditions in the presence of I2, ICl, PhSeCl, PhSCl and p-O2NC6H4SCl to give the corresponding halogen-, selenium- and sulfur-containing disubstituted isoquinolines and naphthyridines, respectively. Monosubstituted isoquinolines and naphthyridines have been synthesized by the metal-catalyzed ring closure of these same iminoalkynes. This methodology accommodates a variety of iminoalkynes and affords the anticipated heterocycles in moderate to excellent yields. The Pd(II)-catalyzed cyclization of 2-(1-alkynyl)arylaldimines in the presence of various alkenes provides an efficient way to synthesize a variety of 4-(1-alkenyl)-3-arylisoquinolines in moderate to excellent yields. The introduction of an ortho-methoxy group on the arylaldimine promotes the Pd-catalyzed cyclization and stabilizes the resulting Pd(II) intermediate, improving the yields of the isoquinoline products. Highly substituted naphthalenes have been synthesized by the palladium-catalyzed annulation of a variety of internal alkynes, in which two new carbon-carbon bonds are formed in a single step under relatively mild reaction conditions. This method has also been used to synthesize carbazoles, although a higher reaction temperature is necessary. The process involves arylpalladation of the alkyne, followed by intramolecular Heck olefination and double bond isomerization. This method accommodates a variety of functional groups and affords the anticipated highly substituted naphthalenes and carbazoles in good to excellent yields. Novel palladium migratiodarylation methodology for the synthesis of complex fused polycycles has been developed, in which one or more sequential Pd-catalyzed intramolecular migration processes involving C-H activation are employed. The chemistry works best with electron-rich aromatics, which is in agreement

  18. Nanostructured palladium tailored via carbonyl chemical route towards oxygen reduction reaction

    International Nuclear Information System (INIS)

    Luo, Y.; Mora-Hernández, J.M.; Estudillo-Wong, L.A.; Arce-Estrada, E.M.; Alonso-Vante, N.

    2015-01-01

    Graphical Abstract: Mass-depending morphologies of nanostructured Palladium obtained via the carbonyl chemical route. Display Omitted -- Highlights: •Mass-depending morphology was observed in nanostructured palladium supported on carbon prepared by the carbonyl chemical route. •The Morphological effect of carbon supported Pd was investigated towards ORR. -- Abstract: Carbon supported palladium nanostructures were synthesized via the carbonyl chemical route. Compared with nanostructured platinum, prepared via carbonyl chemical route, Pd nanomaterials showed mass-loading morphology, whereas particle size and morphology of Pt nanostructures was constant. The oxygen reduction reaction (ORR) on nanostructured Pd, with different morphology in both acid and alkaline medium was investigated. A relationship, based on X-ray diffraction structural analysis pattern, transmission electron microscope, with the Pd morphological effect on ORR activity was identified

  19. Shaping surface of palladium nanospheres through the control of reaction parameters

    International Nuclear Information System (INIS)

    Wang Lianmeng; Tan Enzhong; Guo Lin; Wang Lihua; Han Xiaodong

    2011-01-01

    Solid, cracked, and flower-shaped surfaces of palladium nanospheres with high yields and good uniformity were successfully prepared by a wet chemical method. On the basis of the experimental data, the same size of palladium nanosphere with different surface morphologies can be regulated only by changing the amount of ammonium hydroxide and reductant in one experimental system. The as-prepared products were studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and x-ray diffraction (XRD). In addition, surface-enhanced Raman scattering (SERS) spectra on the as-prepared different surface of palladium nanospheres exhibit high activity towards p-aminothiophenol (PATP) detection, and the result further reveals that the predominance of the a1 vibration mode in the SERS spectra via an electromagnetic (EM) mechanism is significant.

  20. Substoichiometric extraction of traces of gold and palladium

    International Nuclear Information System (INIS)

    Colonat, J.-F.

    1975-01-01

    Several systems for extracting palladium at concentrations ranging from 10 -4 to 10 -6 M/l were studied. Extraction by dithizone is limited by the transformation of the primary complex into a secondary complex which takes place at concentrations around 10 -6 M. This transformation has been demonstrated kinetically. Dimethylglyoxime is an interesting reagent in substoichiometry, in spite of its comparatively low extraction constant. Various complexes which are formed in a highly chlorinated medium have been proposed. Use of copper diethyldithiocarbamate is limited principally by its stability in presence of chlorine ions. The kinetic formation of palladium diethyldithiocarbamate has been studied with greater precision. A direct determination of 100μg of palladium in a copper matrix without preliminary separation has given results comparable in every way with those of other methods. In the case of gold (III) the constants of formation with the diethyldithiocarbamate ion have been determined by an iterative method of calculation, using the influence curves of interfering metals. Finally conditions for an automatization of the substoichiometric extraction, as well as its possibilities for gold determination in the range 200-20ppm, were proposed [fr

  1. Determination of palladium in various samples by atomic absorption spectrometry after preconcentration with dimethylglyoxime on silica gel

    International Nuclear Information System (INIS)

    Tokalioglu, Serife; Oymak, Tuelay; Kartal, Senol

    2004-01-01

    A preconcentration method based on the adsorption of palladium-dimethylglyoxime (DMG) complex on silica gel for the determination of palladium at trace levels by atomic absorption spectrometry (AAS) has been developed. The retained palladium as Pd(DMG) 2 complex was eluted with 1 mol l -1 HCl in acetone. The effect of some analytical parameters such as pH, amount of reagent and the sample volume on the recovery of palladium was examined in synthetic solutions containing street dust matrix. The influence of some matrix ions on the recovery of palladium was investigated by using the developed method when the elements were present both individually and together. The results showed that 2500 μg ml -1 Na + , K + , Mg 2+ , Al 3+ and Fe 3+ ; 5000 μg ml -1 Ca 2+ ; 500 μg ml -1 Pb 2+ ; 125 μg ml -1 Zn 2+ ; 50 μg ml -1 Cu 2+ and 25 μg ml -1 Ni 2+ did not interfere with the palladium signal. At the optimum conditions determined experimentally, the recovery for palladium was found to be 95.3±1.2% at the 95% confidence level. The relative standard deviation and limit of detection (3s/b) of the method were found to be 1.7% and 1.2 μg l -1 , respectively. In order to determine the adsorption behaviour of silica gel, the adsorption isotherm of palladium was studied and the binding equilibrium constant and adsorption capacity were calculated to be 0.38 l mg -1 and 4.06 mg g -1 , respectively. The determination of palladium in various samples was performed by using both flame AAS and graphite furnace AAS. The proposed method was successfully applied for the determination of palladium in the street dust, anode slime, rock and catalytic converter samples

  2. Preparation of Palladium-Impregnated Ceria by Metal Complex Decomposition for Methane Steam Reforming Catalysis

    Directory of Open Access Journals (Sweden)

    Worawat Wattanathana

    2017-01-01

    Full Text Available Palladium-impregnated ceria materials were successfully prepared via an integrated procedure between a metal complex decomposition method and a microwave-assisted wetness impregnation. Firstly, ceria (CeO2 powders were synthesized by thermal decomposition of cerium(III complexes prepared by using cerium(III nitrate or cerium(III chloride as a metal source to form a metal complex precursor with triethanolamine or benzoxazine dimer as an organic ligand. Palladium(II nitrate was consequently introduced to the preformed ceria materials using wetness impregnation while applying microwave irradiation to assist dispersion of the dopant. The palladium-impregnated ceria materials were obtained by calcination under reduced atmosphere of 10% H2 in He stream at 700°C for 2 h. Characterization of the palladium-impregnated ceria materials reveals the influences of the metal complex precursors on the properties of the obtained materials. Interestingly, the palladium-impregnated ceria prepared from the cerium(III-benzoxazine dimer complex revealed significantly higher BET specific surface area and higher content of the more active Pdδ+ (δ > 2 species than the materials prepared from cerium(III-triethanolamine complexes. Consequently, it exhibited the most efficient catalytic activity in the methane steam reforming reaction. By optimization of the metal complex precursors, characteristics of the obtained palladium-impregnated ceria catalysts can be modified and hence influence the catalytic activity.

  3. Palladium emissions in the environment: analytical methods, environmental assessment and health effects

    National Research Council Canada - National Science Library

    Alt, Friedrich; Zereini, Fathi

    2006-01-01

    ... (Eds)). But there is a clear lack of information concerning palladium. It is very important to condense the present state of research findings from emission to potential health risks for the environment and humans. Very important is the chapter about analytical determination of palladium, which shows clearly the problems of several analytic...

  4. Effects of soldering methods on tensile strength of a gold-palladium metal ceramic alloy.

    Science.gov (United States)

    Ghadhanfari, Husain A; Khajah, Hasan M; Monaco, Edward A; Kim, Hyeongil

    2014-10-01

    The tensile strength obtained by conventional postceramic application soldering and laser postceramic welding may require more energy than microwave postceramic soldering, which could provide similar tensile strength values. The purpose of the study was to compare the tensile strength obtained by microwave postceramic soldering, conventional postceramic soldering, and laser postceramic welding. A gold-palladium metal ceramic alloy and gold-based solder were used in this study. Twenty-seven wax specimens were cast in gold-palladium noble metal and divided into 4 groups: laser welding with a specific postfiller noble metal, microwave soldering with a postceramic solder, conventional soldering with the same postceramic solder used in the microwave soldering group, and a nonsectioned control group. All the specimens were heat treated to simulate a normal porcelain sintering sequence. An Instron Universal Testing Machine was used to measure the tensile strength for the 4 groups. The means were analyzed statistically with 1-way ANOVA. The surface and fracture sites of the specimens were subjectively evaluated for fracture type and porosities by using a scanning electron microscope. The mean (standard deviation) ultimate tensile strength values were as follows: nonsectioned control 818 ±30 MPa, microwave 516 ±34 MPa, conventional 454 ±37 MPa, and laser weld 191 ±39 MPa. A 1-way ANOVA showed a significant difference in ultimate tensile strength among the groups (F3,23=334.5; Ptensile strength for gold and palladium noble metals than either conventional soldering or laser welding. Conventional soldering resulted in a higher tensile strength than laser welding. Under the experimental conditions described, either microwave or conventional postceramic soldering would appear to satisfy clinical requirements related to tensile strength. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  5. The study of hydrogen electrosorption in layered nickel foam/palladium/carbon nanofibers composite electrodes

    International Nuclear Information System (INIS)

    Skowronski, J.M.; Czerwinski, A.; Rozmanowski, T.; Rogulski, Z.; Krawczyk, P.

    2007-01-01

    In the present work, the process of hydrogen electrosorption occurring in alkaline KOH solution on the nickel foam/palladium/carbon nanofibers (Ni/Pd/CNF) composite electrodes is examined. The layered Ni/Pd/CNF electrodes were prepared by a two-step method consisting of chemical deposition of a thin layer of palladium on the nickel foam support to form Ni/Pd electrode followed by coating the palladium layer with carbon nanofibers layer by means of the CVD method. The scanning electron microscope was used for studying the morphology of both the palladium and carbon layer. The process of hydrogen sorption/desorption into/from Ni/Pd as well as Ni/Pd/CNF electrode was examined using the cyclic voltammetry method. The amount of hydrogen stored in both types of composite electrodes was shown to increase on lowering the potential of hydrogen sorption. The mechanism of the anodic desorption of hydrogen changes depending on whether or not CNF layer is present on the Pd surface. The anodic peak corresponding to the removal of hydrogen from palladium is lower for Ni/Pd/CNF electrode as compared to that measured for Ni/Pd one due to a partial screening of the Pd surface area by CNF layer. The important feature of Ni/Pd/CNF electrode is anodic peak appearing on voltammetric curves at potential ca. 0.4 V more positive than the peak corresponding to hydrogen desorption from palladium. The obtained results showed that upon storing the hydrogen saturated Ni/Pd/CNF electrode at open circuit potential, diffusion of hydrogen from carbon to palladium phase occurs due to interaction between carbon fibers and Pd sites on the nickel foam support

  6. Arsenic (III Adsorption Using Palladium Nanoparticles from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Farzaneh Arsiya

    2017-07-01

    Full Text Available The presence of Arsenic in drinking water is the greatest threat to health effects especially in water. The purpose of this study is application of green palladium nanoparticles for removal of trivalent Arsenic from aqueous solutions and also the impact of some factors such as retention time, pH, concentration of palladium nanoparticles and Arsenic concentrations was studied. The values for Arsenic removal from aqueous solutions were measured by furnace atomic adsorption spectrometry (Conter AA700. In the study, Langmuir and Freundlich isotherm models and pseudo-second order kinetic model were studied. The results of  optimization is shown that 0.5 g of nanoparticles can removed %99.8 of Arsenic with initial concentration of  0.5 g/l, in 5 minutes at pH=4. Langmuir model, Freundlich model (R2=0.94 and pseudo-second order kinetic model (R2=0.99 shown high correlation for removing of Arsenic from aqueous solutions. It was found, palladium nanoparticles can be used as an efficient method to remove Arsenic from aqueous solutions in a short time.

  7. γ-Diimine palladium(II based complexes mediated polymerization of methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Mahmoud Sunjuk

    2017-02-01

    Full Text Available The synthesis of new palladium(II complexes of the type [Pd(A–NC–ph–CN–ACl2] (4a–e (A = cyclohexyl (a, 2-isoprpropyl (b, pyrenyl (c, naphthyl (d, and 2,6-diisopropyl (e is described. The isolated γ-diimine ligands and their corresponding palladium(II complexes were characterized by their physical properties, elemental analysis, 1H NMR-, 13C NMR, and infrared spectroscopy. The palladium(II complexes (4a–e were employed successfully as catalysts for atom transfer radical polymerization (ATRP of methyl methacrylate (MMA in the presence of ethyl-2-bromoisobutyrate (EBIB as initiator at 90 °C. Polymerization with these catalyst systems afforded polymers with low molecular weight distribution (Mw/Mn and syndio-rich atactic poly (MMA with relatively higher [rr] diads.

  8. Investigation of mechanical and structural characteristics of platinum and palladium at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Trumie, B. T.; Gomidzelovie, L.; Marjanovic, S. R.; Krstic, V. R.

    2015-03-30

    In order to broaden future application of products based on platinum and palladium a comparative analysis of their high-temperature mechanical properties was performed. Platinum and palladium are of great importance and are widely used in chemical industry, electronics, for making laboratory dishes, to name a few. Mechanical properties of pure metals, such as: tensile strength, creep rate and rupture time were investigated using universal testing machine for tensile testing of materials. Microstructure of samples was investigated by optical microscopy. Based on obtained results it can be concluded that the platinum, compared to palladium, is superior for high-temperature applications. (Author)

  9. Investigation of mechanical and structural characteristics of platinum and palladium at high temperatures

    International Nuclear Information System (INIS)

    Trumie, B. T.; Gomidzelovie, L.; Marjanovic, S. R.; Krstic, V. R.

    2015-01-01

    In order to broaden future application of products based on platinum and palladium a comparative analysis of their high-temperature mechanical properties was performed. Platinum and palladium are of great importance and are widely used in chemical industry, electronics, for making laboratory dishes, to name a few. Mechanical properties of pure metals, such as: tensile strength, creep rate and rupture time were investigated using universal testing machine for tensile testing of materials. Microstructure of samples was investigated by optical microscopy. Based on obtained results it can be concluded that the platinum, compared to palladium, is superior for high-temperature applications. (Author)

  10. Some remarks on the neutron elastic- and enelastic-scattering cross sections of palladium

    International Nuclear Information System (INIS)

    Chiba, S.; Guenther, P.T.; Smith, A.B.

    1989-05-01

    The cross sections for the elastic-scattering of 5.9, 7.1 and 8.0 MeV neutrons from elemental palladium were measured at forty scattering angles distributed between ∼15/degree/ and 160/degree/. The inelastic-scattering cross sections for the excitation of palladium levels at energies of 260 keV to 560 keV were measured with high resolution at the same energies, and at a scattering angle of 80/degree/. The experimental results were combined with lower-energy values previously obtained by this group to provide a comprehensive data base extending from near the inelastic-scattering threshold to 8 MeV. That data base was interpreted in terms of a coupled-channel model, including the inelastic excitation of one- and two-phonon vibrational levels of the even isotopes of palladium. It was concluded that the palladium inelastic-scattering cross section, at the low energies of interest in assessment of fast-fission-reactor performance, are large (∼50% greater than given in widely used evaluated fission-product data files). They primarily involve compound-nucleus processes, with only a small direct-reaction component attributable to the excitation of the one-phonon, 2 + , vibrational levels of the even isotopes of palladium. 24 refs., 6 figs

  11. Functionalized Palladium Nanoparticles for Hydrogen Peroxide Biosensor

    Directory of Open Access Journals (Sweden)

    H. Baccar

    2011-01-01

    Full Text Available We present a comparison between two biosensors for hydrogen peroxide (H2O2 detection. The first biosensor was developed by the immobilization of Horseradish Peroxidase (HRP enzyme on thiol-modified gold electrode. The second biosensor was developed by the immobilization of cysteamine functionalizing palladium nanoparticles on modified gold surface. The amino groups can be activated with glutaraldehyde for horseradish peroxidase immobilization. The detection of hydrogen peroxide was successfully observed in PBS for both biosensors using the cyclic voltammetry and the chronoamperometry techniques. The results show that the limit detection depends on the large surface-to-volume ratio attained with palladium nanoparticles. The second biosensor presents a better detection limit of 7.5 μM in comparison with the first one which is equal to 75 μM.

  12. Palladium-catalysed arylation of sulfonamide stabilised enolates

    CSIR Research Space (South Africa)

    Zeevaart, JG

    2005-03-07

    Full Text Available Alpha-Arylation of inethanesulfonamides using palladium catalysis is described. For example, treatment of N-benzyl-Nmethylmethanesulfonamide with catalytic Pd (OAc) (2) in the presence of sodium tert-butoxide, triphenylphosphine and toluene afforded...

  13. HE3 outgassing from four working palladium and uranium beds

    International Nuclear Information System (INIS)

    Souers, P. C.; Coronado, P. R.; Fearon, F. M.; Garza, R. G.; Shaw , J. F.; Stump, R. K.; Tsugawa, R. T.

    1988-01-01

    The He 3 output from two palladium and two uranium beds storing T 2 and D-T was studied as a function of time. Three of the beds were started new and watched for a year; the fourth bed was twelve years old. All four were beds used in routine tritium handling. Initial stoichiometries were PdT/sub 0.3/ and UT/sub 0.7/ so that both operated at similar 1 to 130 kPa pressures. The He 3 from palladium ranged from the 0.002 mo1% lower level of sensitivity to 0.01% for PdT 2 at one year of age. The UT system showed 0.1% He 3 at 4 to 62 days and 0.1 to 10% at longer times, with the first cuts being high in He 3 . The palladium bed with 95 to 97% pure T 2 enriches the output to as high as 97 to 99%. 9 refs., 1 fig., 2 tabs

  14. Noise temperature measurements for the determination of the thermodynamic temperature of the melting point of palladium

    Energy Technology Data Exchange (ETDEWEB)

    Edler, F.; Kuhne, M.; Tegeler, E. [Bundesanstalt Physikalisch-Technische, Berlin (Germany)

    2004-02-01

    The thermodynamic temperature of the melting point of palladium in air was measured by noise thermometric methods. The temperature measurement was based on noise comparison using a two-channel arrangement to eliminate parasitic noises of electronic components by cross correlation. Three miniature fixed points filled with pure palladium (purity: {approx}99.99%, mass: {approx}90 g) were used to realize the melts of the fixed point metal. The measured melting temperature of palladium in air amounted to 1552.95 deg C {+-} 0.21 K (k = 2). This temperature is 0.45 K lower than the temperature of the melting point of palladium measured by radiation thermometry. (authors)

  15. Preparation of palladium impregnated alumina adsorbents: Thermal and neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Sumanta; Gupta, N.K.; Roy, S.P.; Dash, S.; Kumar, A.; Bamankar, Y.R.; Rao, T.V. Vittal [Product Development Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, N. [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Naik, Y., E-mail: ynaik@barc.gov.in [Product Development Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2016-02-10

    Highlights: • Pd/Al{sub 2}O{sub 3} composite microspheres particles with high surface area were prepared sol–gel process. • Scanning electron microscopy (SEM) studies on silver coated particle. • Content of the palladium was determined using Neutron Activation Analysis (NAA). • Decomposition study has been done by quadrupole mass analyser. - Abstract: Pd/Al{sub 2}O{sub 3} composite microspheres particles with high surface area were prepared sol–gel process. The decomposition of dried gel-particles was studied by TGA/DTA and FT-IR technique. TGA studies indicated that formation of palladium is marked by a broad exothermic peak with a loss of water and oxidation of trapped HMTA/Urea nitrate mixture. The main decomposition reaction took place in the temperature range of 660–1250 K in helium and relatively lower temperature of 400 K to 1250 K in oxygen. Optical microscopy indicated that the distribution of palladium is uniform. SEM studies on silver coated particle indicated that there was surface erosion of some gel spheres while in few of them micro cracks were seen at high resolution. Content of the palladium was determined using Neutron Activation Analysis (NAA). Decomposition at various temperatures was studied using Residual gas analyser and decomposition species were identified using quadrupole mass analyser.

  16. Development of a second generation palladium-catalyzed cycloalkenylation and its application to bioactive natural product synthesis.

    Science.gov (United States)

    Toyota, Masahiro

    2013-07-01

    A novel palladium-catalyzed intramolecular oxidative alkylation of unactivated olefins is described. This protocol was devised to solve one of the drawbacks of the original palladium-catalyzed cycloalkenylation that we developed. We call this new procedure the 'second generation palladium-catalyzed cycloalkenylation'. This protocol has been applied to the total syntheses of cis-195A, trans-195A, boonein, scholareins A, C, D, and alpha-skytanthine.

  17. Effect of heating palladium-silver alloys on ceramic bond strength.

    Science.gov (United States)

    Li, Jie-yin; Li, Rui-nan; Chang, Shao-hai; Zhuang, Pei-lin; Liao, Juan-kun; Ye, Xiu-hua; Ye, Jian-tao

    2015-11-01

    The effects of different heat treatments on the internal oxidation and metal-ceramic bond in Pd-Ag alloys with different trace elements require further documentation. The purpose of this in vitro study was to determine whether heat treatment affects the metal-ceramic bond strength of 2 Pd-Ag alloys containing different trace elements. Thirteen cast specimens (25×3×0.5 mm) from each of 2 Pd-Ag alloy groups (W-1 and Argelite 61+3) were allocated to heat treatments before porcelain application: heating under reduced atmospheric pressure of 0.0014 MPa and 0.0026 MPa and heating under normal atmospheric pressure. Bond strengths were evaluated using a 3-point bending test according to ISO9693. Results were analyzed using 2-way ANOVA and Tukey HSD test (α=.05). Visual observation was used to determine the failure types of the fractured specimens. Scanning electron microscopy and energy dispersive spectroscopy were used to study morphologies, elemental compositions, and distributions in the specimens. The W-1 group had a mean bond strength significantly higher than that of Argelite 61+3 (PHeating under reduced atmospheric pressures of 0.0014 MPa and 0.0026 MPa resulted in similar bond strengths (P=.331), and both pressures had significantly higher bond strengths than that of heating under normal atmospheric pressure (P=.002, PHeating under different air pressures resulted in Pd-Ag alloys that contained either Sn or In and Ga, with various degrees of internal oxidation and different quantities of metallic nodules. Heating under reduced atmospheric pressure effectively improved the bond strength of the ceramic-to-Pd-Ag alloys. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  18. Palladium-Catalyzed Asymmetric Quaternary Stereocenter Formation

    NARCIS (Netherlands)

    Gottumukkala, Aditya L.; Matcha, Kiran; Lutz, Martin; de Vries, Johannes G.; Minnaard, Adriaan J.

    2012-01-01

    An efficient palladium catalyst is presented for the formation of benzylic quaternary stereocenters by conjugate addition of arylboronic acids to a variety of beta,beta-disubstituted carbocyclic, heterocyclic, and acyclic enones. The catalyst is readily prepared from PdCl2, PhBOX, and AgSbF6, and

  19. Palladium-catalyzed asymmetric quaternary stereocenter formation

    NARCIS (Netherlands)

    Gottumukkala, A.L.; Matcha, K.; Lutz, M.; de Vries, J.G.; Minnaard, A.J.

    2012-01-01

    An efficient palladium catalyst is presented for the formation of benzylic quaternary stereocenters by conjugate addition of arylboronic acids to a variety of β,β-disubstituted carbocyclic, heterocyclic, and acyclic enones. The catalyst is readily prepared from PdCl2, PhBOX, and AgSbF6, and provides

  20. Preliminary design of fusion reactor fuel cleanup system by palladium alloy membrane method

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi; Konishi, Satoshi; Naruse, Yuji

    1981-10-01

    A design of palladium diffuser and Fuel Cleanup System (FCU) for D-T fusion reactor is proposed. Feasibility of palladium alloy membrane method is discussed based on the early studies by the authors. Operating conditions of the palladium diffuser are determined experimentally. Dimensions of the diffuser are estimated from computer simulation. FCU system is designed under the feed conditions of Tritium Systems Test Assembly (TSTA) at Los Alamos Scientific Laboratory. The system is composed of Pd-diffusers, catalytic oxidizer, freezer and zink beds, and has some advantages in system layout and operation. This design can readily be extended to other conditions of plasma exhaust gases. (author)

  1. The Palladium-Catalyzed Aerobic Kinetic Resolution of Secondary Alcohols: Reaction Development, Scope, and Applications

    KAUST Repository

    Ebner, Davidâ C.; Bagdanoff, Jeffreyâ T.; Ferreira, Ericâ M.; McFadden, Ryanâ M.; Caspi, Danielâ D.; Trend, Raissaâ M.; Stoltz, Brianâ M.

    2009-01-01

    The first palladium-catalyzed enantioselective oxidation of secondary alcohols has been developed, utilizing the readily available diamine (-)-sparteine as a chiral ligand and molecular oxygen as the stoichiometric oxidant. Mechanistic insights regarding the role of the base and hydrogen-bond donors have resulted in several improvements to the original system. Namely, addition of cesium carbonate and tert-butyl alcohol greatly enhances reaction rates, promoting rapid resolutions. The use of chloroform as solvent allows the use of ambient air as the terminal oxidant at 23 degrees C, resulting in enhanced catalyst selectivity. These improved reaction conditions have permitted the successful kinetic resolution of benzylic, allylic, and cyclopropyl secondary alcohols to high enantiomeric excess with good-to-excellent selectivity factors. This catalyst system has also been applied to the desymmetrization of meso-diols, providing high yields of enantioenriched hydroxyketones.

  2. The Palladium-Catalyzed Aerobic Kinetic Resolution of Secondary Alcohols: Reaction Development, Scope, and Applications

    KAUST Repository

    Ebner, Davidâ C.

    2009-12-07

    The first palladium-catalyzed enantioselective oxidation of secondary alcohols has been developed, utilizing the readily available diamine (-)-sparteine as a chiral ligand and molecular oxygen as the stoichiometric oxidant. Mechanistic insights regarding the role of the base and hydrogen-bond donors have resulted in several improvements to the original system. Namely, addition of cesium carbonate and tert-butyl alcohol greatly enhances reaction rates, promoting rapid resolutions. The use of chloroform as solvent allows the use of ambient air as the terminal oxidant at 23 degrees C, resulting in enhanced catalyst selectivity. These improved reaction conditions have permitted the successful kinetic resolution of benzylic, allylic, and cyclopropyl secondary alcohols to high enantiomeric excess with good-to-excellent selectivity factors. This catalyst system has also been applied to the desymmetrization of meso-diols, providing high yields of enantioenriched hydroxyketones.

  3. Extracellular Palladium Nanoparticle Production using Geobacter sulfurreducens

    KAUST Repository

    Yates, Matthew D.

    2013-09-03

    Sustainable methods are needed to recycle precious metals and synthesize catalytic nanoparticles. Palladium nanoparticles can be produced via microbial reduction of soluble Pd(II) to Pd(0), but in previous tests using dissimilatory metal reducing bacteria (DMRB), the nanoparticles were closely associated with the cells, occupying potential reductive sites and eliminating the potential for cell reuse. The DMRB Geobacter sulfurreducens was shown here to reduce soluble Pd(II) to Pd(0) nanoparticles primarily outside the cell, reducing the toxicity of metal ions, and allowing nanoparticle recovery without cell destruction that has previously been observed using other microorganisms. Cultures reduced 50 ± 3 mg/L Pd(II) with 1% hydrogen gas (v/v headspace) in 6 h incubation tests [100 mg/L Pd(II) initially], compared to 8 ± 3 mg/L (10 mM acetate) without H2. Acetate was ineffective as an electron donor for palladium removal in the presence or absence of fumarate as an electron acceptor. TEM imaging verified that Pd(0) nanoparticles were predominantly in the EPS surrounding cells in H2-fed cultures, with only a small number of particles visible inside the cell. Separation of the cells and EPS by centrifugation allowed reuse of the cell suspensions and effective nanoparticle recovery. These results demonstrate effective palladium recovery and nanoparticle production using G. sulfurreducens cell suspensions and renewable substrates such as H2 gas. © 2013 American Chemical Society.

  4. Fiscal 1997 report on the development of new hydrogen atomic energy demonstrative technology; 1997 nendo kenkyu hokokusho (shinsuiso energy jissho gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    In this validation study, phenomena of excess heat which are said to be generated by electrolysis of deuterium using palladium metal, etc. as electrode are taken as `new hydrogen atomic energy,` and to clarify a possibility of using them as a future energy source, the abnormal heating phenomenon was validated and the mechanism was elucidated. The study targeted quantitative control of heat emissions. The study was finished in 1997, the fifth year from the start. The excess heat measurement could partially be reproduced; however, when conducting a confirmation experiment on the excess heat by another more reliable method under the same condition, it was found that the value of excess heat was not an absolute value exceeding measuring sensitivity and errors of the system. If the excess heat of 0.1W order is to be emitted in nuclear reaction, any reactive product should be detected in a substantial quantity. However, the product of a large quantity was not found. A possibility was found out of an increase in nuclear reaction ratio inside solid by low energy deuterium irradiation. From the above, it was concluded that the use of new hydrogen atomic energy was negative. 20 refs., 149 figs., 29 tabs.

  5. Formation of palladium hydrides in low temperature Ar/H_2-plasma

    International Nuclear Information System (INIS)

    Wulff, H.; Quaas, M.; Deutsch, H.; Ahrens, H.; Fröhlich, M.; Helm, C.A.

    2015-01-01

    20 nm thick Pd coatings deposited on Si substrates with 800 nm SiO_2 and 1 nm Cr buffer layers were treated in a 2.45 GHz microwave plasma source at 700 W plasma power and 40 Pa working pressure without substrate heating. For obtaining information on the effect of energy influx due to ion energy on the palladium films the substrate potential was varied from U_s_u_b = 0 V to − 150 V at constant gas flow corresponding to mean ion energies E_i from 0.22 eV ∙ cm"−"2 ∙ s"−"1 to 1.28 eV ∙ cm"−"2 ∙ s"−"1. In contrast to high pressure reactions with metallic Pd, under plasma exposure we do not observe solid solutions over a wide range of hydrogen concentration. The hydrogen incorporation in Pd films takes place discontinuously. At 0 V substrate voltage palladium hydride is formed in two steps to PdH_0_._1_4 and PdH_0_._5_7. At − 50 V substrate voltage PdH_0_._5_7 is formed directly. However, substrate voltages of − 100 V and − 150 V cause shrinking of the unit cell. We postulate the formation of two fcc vacancy palladium hydride clusters PdH_V_a_c(I) and PdH_V_a_c(II). Under longtime plasma exposure the fcc PdH_V_a_c(II) phase forms cubic PdH_1_._3_3. The fcc PdH_0_._5_7 phase decomposes at temperatures > 300 °C to form metallic fcc Pd. The hydrogen removal causes a decrease of lattice defects. In situ high temperature diffractometry measurements also confirm the existence of PdH_V_a_c(II) as a palladium hydride phase. Stoichiometric relationship between cubic PdH_1_._3_3 and fcc PdH_V_a_c(II) becomes evident from XR measurements and structure considerations. We assume both phases have the chemical composition Pd_3H_4. Up to 700 °C we observe phase transformation between both the fcc PdH_V_a_c(II) and cubic PdH_1_._3_3 phases. These phase transformations could be explained analog to a Bain distortion by displacive solid state structural changes. - Highlights: • Thin Pd films were treated under low pressure conditions by an Ar/H_2-plasma. • The

  6. Stereoselective synthesis of tricyclic compounds by intramolecular palladium-catalyzed addition of aryl iodides to carbonyl groups

    Directory of Open Access Journals (Sweden)

    Jakub Saadi

    2016-06-01

    Full Text Available Starting from γ-ketoesters with an o-iodobenzyl group we studied a palladium-catalyzed cyclization process that stereoselectively led to bi- and tricyclic compounds in moderate to excellent yields. Four X-ray crystal structure analyses unequivocally defined the structure of crucial cyclization products. The relative configuration of the precursor compounds is essentially transferred to that of the products and the formed hydroxy group in the newly generated cyclohexane ring is consistently in trans-arrangement with respect to the methoxycarbonyl group. A transition-state model is proposed to explain the observed stereochemical outcome. This palladium-catalyzed Barbier-type reaction requires a reduction of palladium(II back to palladium(0 which is apparently achieved by the present triethylamine.

  7. Characterization of intracellular palladium nanoparticles synthesized by Desulfovibrio desulfuricans and Bacillus benzeovorans

    Energy Technology Data Exchange (ETDEWEB)

    Omajali, Jacob B., E-mail: JBO037@bham.ac.uk, E-mail: jbomajali@gmail.com; Mikheenko, Iryna P. [University of Birmingham, Unit of Functional Bionanomaterials, School of Biosciences, Institute of Microbiology and Infection (United Kingdom); Merroun, Mohamed L. [University of Granada, Department of Microbiology, Faculty of Sciences (Spain); Wood, Joseph [University of Birmingham, School of Chemical Engineering (United Kingdom); Macaskie, Lynne E. [University of Birmingham, Unit of Functional Bionanomaterials, School of Biosciences, Institute of Microbiology and Infection (United Kingdom)

    2015-06-15

    Early studies have focused on the synthesis of palladium nanoparticles within the periplasmic layer or on the outer membrane of Desulfovibrio desulfuricans and on the S-layer protein of Bacillus sphaericus. However, it has remained unclear whether the synthesis of palladium nanoparticles also takes place in the bacterial cell cytoplasm. This study reports the use of high-resolution scanning transmission electron microscopy with a high-angle annular dark field detector and energy dispersive X-ray spectrometry attachment to investigate the intracellular synthesis of palladium nanoparticles (Pd NPs). We show the intracellular synthesis of Pd NPs within cells of two anaerobic strains of D. desulfuricans and an aerobic strain of B. benzeovorans using hydrogen and formate as electron donors. The Pd nanoparticles were small and largely monodispersed, between 0.2 and 8 nm, occasionally from 9 to 12 nm with occasional larger nanoparticles. With D. desulfuricans NCIMB 8307 (but not D. desulfuricans NCIMB 8326) and with B. benzeovorans NCIMB 12555, the NPs were larger when made at the expense of formate, co-localizing with phosphate in the latter, and were crystalline, but were amorphous when made with H{sub 2,} with no phosphorus association. The intracellular Pd nanoparticles were mainly icosahedrons with surfaces comprising {111} facets and about 5 % distortion when compared with that of bulk palladium. The particles were more concentrated in the cell cytoplasm than the cell wall, outer membrane, or periplasm. We provide new evidence for synthesis of palladium nanoparticles within the cytoplasm of bacteria, which were confirmed to maintain cellular integrity during this synthesis.

  8. Anionic Palladium(0) and Palladium(II) Ate Complexes.

    Science.gov (United States)

    Kolter, Marlene; Böck, Katharina; Karaghiosoff, Konstantin; Koszinowski, Konrad

    2017-10-16

    Palladium ate complexes are frequently invoked as important intermediates in Heck and cross-coupling reactions, but so far have largely eluded characterization at the molecular level. Here, we use electrospray-ionization mass spectrometry, electrical conductivity measurements, and NMR spectroscopy to show that the electron-poor catalyst [L 3 Pd] (L=tris[3,5-bis(trifluoromethyl)phenyl]phosphine) readily reacts with Br - ions to afford the anionic, zero-valent ate complex [L 3 PdBr] - . In contrast, more-electron-rich Pd catalysts display lower tendencies toward the formation of ate complexes. Combining [L 3 Pd] with LiI and an aryl iodide substrate (ArI) results in the observation of the Pd II ate complex [L 2 Pd(Ar)I 2 ] - . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Morphological Study Of Palladium Thin Films Deposited By Sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Salcedo, K L; Rodriguez, C A [Grupo Plasma Laser y Aplicaciones, Ingenieria Fisica, Universidad Tecnologica de Pereira (Colombia); Perez, F A [WNANO, West Virginia University (United States); Riascos, H [Grupo Plasma Laser y Aplicaciones, Departamento de Fisica, Universidad Tecnologica de Pereira (Colombia)

    2011-01-01

    This paper presents a morphological analysis of thin films of palladium (Pd) deposited on a substrate of sapphire (Al{sub 2}O{sub 3}) at a constant pressure of 3.5 mbar at different substrate temperatures (473 K, 523 K and 573 K). The films were morphologically characterized by means of an Atomic Force Microscopy (AFM); finding a relation between the roughness and the temperature. A morphological analysis of the samples through AFM was carried out and the roughness was measured by simulating the X-ray reflectivity curve using GenX software. A direct relation between the experimental and simulation data of the Palladium thin films was found.

  10. Morphological Study Of Palladium Thin Films Deposited By Sputtering

    International Nuclear Information System (INIS)

    Salcedo, K L; Rodriguez, C A; Perez, F A; Riascos, H

    2011-01-01

    This paper presents a morphological analysis of thin films of palladium (Pd) deposited on a substrate of sapphire (Al 2 O 3 ) at a constant pressure of 3.5 mbar at different substrate temperatures (473 K, 523 K and 573 K). The films were morphologically characterized by means of an Atomic Force Microscopy (AFM); finding a relation between the roughness and the temperature. A morphological analysis of the samples through AFM was carried out and the roughness was measured by simulating the X-ray reflectivity curve using GenX software. A direct relation between the experimental and simulation data of the Palladium thin films was found.

  11. Supported palladium nanoparticles synthesized by living plants as a catalyst for Suzuki-Miyaura reactions.

    Directory of Open Access Journals (Sweden)

    Helen L Parker

    Full Text Available The metal accumulating ability of plants has previously been used to capture metal contaminants from the environment; however, the full potential of this process is yet to be realized. Herein, the first use of living plants to recover palladium and produce catalytically active palladium nanoparticles is reported. This process eliminates the necessity for nanoparticle extraction from the plant and reduces the number of production steps compared to traditional catalyst palladium on carbon. These heterogeneous plant catalysts have demonstrated high catalytic activity in Suzuki coupling reactions between phenylboronic acid and a range of aryl halides containing iodo-, bromo- and chloro- moieties.

  12. Superconductivity and the structural phase transitions in palladium hydride and palladium deuteride

    International Nuclear Information System (INIS)

    Standley, R.W.

    1980-01-01

    The results of two experimental studies of the superconducting transition temperature, T/sub c/, of palladium hydride, PdH/sub x/, and palladium deuteride, PdD/sub x/, are presented. In the first study, the superconducting transition temperature of PdH/sub x/(D/sub x/) is studied as a function of H(D) concentration, x, in the temperature range from 0.2 K to 4K. The data join smoothly with those reported previously by Miller and Satterthwaite at higher temperatures, and the composite data are described by the empirical relation T/sub c/ = 150.8 (x-x/sub o/) 2 244 , where x/sub o/ = 0.715 for hydride samples and 0.668 for deuteride samples. The results, when compared with the theoretical predictions of Klein and Papaconstantopoulos, et al., raise questions about the validity of their explanation of the reverse isotope effect, which is based solely on a difference in force constants. In the second study, the effect of the order-disorder structural transition associated with the 50 K anomaly on the superconductivity of PdH/sub x/(D/sub x/) is investigated. Samples were quenched to low temperatures in the disordered state, and their transition temperatures measured. The samples were then annealed just below the anomaly temperature, and the ordering process followed by monitoring the change in sample resistance. The transition temperatures in the ordered state were then measured

  13. A dataset for preparing pristine graphene-palladium nanocomposites using swollen liquid crystal templates

    Science.gov (United States)

    Vats, Tripti; Siril, Prem Felix

    2017-12-01

    Pristine graphene (G) has not received much attention as a catalyst support, presumably due to its relative inertness as compared to reduced graphene oxide (RGO). In the present work, we used swollen liquid crystals (SLCs) as nano-reactors for graphene-palladium nanocomposites synthesis. The 'soft' confinement of SLCs directs the growth of palladium (Pd) nanoparticles over the G sheets. In this dataset we include all the parameters and details of different techniques used for the characterization of G, SLCs and synthesized G-Pd nanocomposites. The synthesized G-palladium nanocomposites (Pd-G) exhibited improved catalytic activity compared with Pd-RGO and Pd nanoparticles, in the hydrogenation of nitrophenols and C-C coupling reactions.

  14. Two-dimensional transient far-field analysis for the excess temperature from an arbitrary source

    Energy Technology Data Exchange (ETDEWEB)

    Witten, A.J.; Long, E.C.

    1978-07-01

    An analytic solution is presented for the two-dimensional time-dependent advective diffusion equation governing the distribution of excess temperature in a river of uniform width, depth, and downstream flow. The solution is also applicable to a straight coastline with uniform longshore flow. Exact solutions are obtained for a point heat source and a particular line heat source, while an approximate representation is given for an arbitrary time-varying heat source. These solutions are incorporated into a computer program which calculates excess temperature and time rate-of-change of excess temperature in a river or coast as a result of waste heat discharged from various transient sources.

  15. Linking Excessive Heat with Daily Heat-Related Mortality over the Coterminous United States

    Science.gov (United States)

    Quattrochi, Dale A.; Crosson, William L.; Al-Hamdan, Mohammad Z.; Estes, Maurice G., Jr.

    2014-01-01

    In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization, which contributes to local-scale urban heat islands, it is very likely that extreme heat events (EHEs) will become more common and more severe in the U.S. This research seeks to provide historical and future measures of climate-driven extreme heat events to enable assessments of the impacts of heat on public health over the coterminous U.S. We use atmospheric temperature and humidity information from meteorological reanalysis and from Global Climate Models (GCMs) to provide data on past and future heat events. The focus of research is on providing assessments of the magnitude, frequency and geographic distribution of extreme heat in the U.S. to facilitate public health studies. In our approach, long-term climate change is captured with GCM outputs, and the temporal and spatial characteristics of short-term extremes are represented by the reanalysis data. Two future time horizons for 2040 and 2090 are compared to the recent past period of 1981- 2000. We characterize regional-scale temperature and humidity conditions using GCM outputs for two climate change scenarios (A2 and A1B) defined in the Special Report on Emissions Scenarios (SRES). For each future period, 20 years of multi-model GCM outputs are analyzed to develop a 'heat stress climatology' based on statistics of extreme heat indicators. Differences between the two future and the past period are used to define temperature and humidity changes on a monthly time scale and regional spatial scale. These changes are combined with the historical meteorological data, which is hourly and at a spatial scale (12 km) much finer than that of GCMs, to create future climate realizations. From these realizations, we compute the daily heat stress measures and related spatially-specific climatological fields, such as the mean annual number of days above certain thresholds of maximum and minimum air

  16. Camphyl-based α-diimine palladium complexes: highly efficient precatalysts for direct arylation of thiazoles in open-air.

    Science.gov (United States)

    Chen, Fu-Min; Lu, Dong-Dong; Hu, Li-Qun; Huang, Ju; Liu, Feng-Shou

    2017-07-21

    Based on the strategy of the development of phosphine-free palladium-catalyzed direct C-H arylation, a series of camphyl-based α-diimine palladium complexes bearing sterically bulky substituents were synthesized and characterized. The palladium complexes were applied for the cross-coupling of thiazole derivatives with aryl bromides. The effect of the sterically bulky substituent on the N-aryl moiety as well as the reaction conditions was screened. Under the optimal protocols, a wide range of aryl bromides can be smoothly coupled with thiazoles in good to excellent yields in the presence of a low palladium loading of 0.2 mol% under open-air conditions.

  17. Recovery of hydrogen from impurities using a palladium membrane reactor

    International Nuclear Information System (INIS)

    Willms, R.S.; Okuno, K.

    1993-01-01

    One of the important steps in processing the exhaust from a fusion reactor is recovering tritium which is incorporated into molecules such as water and methane. One device which may prove to be very effective for this purpose is a palladium membrane reactor. This is a reactor which incorporates a Pd/Ag membrane in the reactor geometry. Reactions such as water gas shift, steam reforming and methane cracking can be carried out over the reactor catalyst, and the product hydrogen can be simultaneously removed from the reacting mixture. Because product is removed, greater than usual conversions can be obtained. In addition ultrapure hydrogen is produced, eliminating the need for an additional processing step. A palladium membrane reactor has been built and tested with three different catalysts. Initial results with a Ni-based catalyst show that it is very effective at promoting all three reactions listed above. Under the proper conditions, hydrogen recoveries approaching 100% have been observed. This study serves to experimentally validate the palladium membrane reactor as potentially important tool for fusion fuel processing

  18. Heat exposure and socio-economic vulnerability as synergistic factors in heat-wave-related mortality

    International Nuclear Information System (INIS)

    Rey, Gregoire; Fouillet, Anne; Bessemoulin, Pierre; Frayssinet, Philippe; Dufour, Anne; Jougla, Eric; Hemon, Denis

    2009-01-01

    Heat waves may become a serious threat to the health and safety of people who currently live in temperate climates. It was therefore of interest to investigate whether more deprived populations are more vulnerable to heat waves. In order to address the question on a fine geographical scale, the spatial heterogeneity of the excess mortality in France associated with the European heat wave of August 2003 was analysed. A deprivation index and a heat exposure index were used jointly to describe the heterogeneity on the Canton scale (3,706 spatial units). During the heat wave period, the heat exposure index explained 68% of the extra-Poisson spatial variability of the heat wave mortality ratios. The heat exposure index was greater in the most urbanized areas. For the three upper quintiles of heat exposure in the densely populated Paris area, excess mortality rates were twofold higher in the most deprived Cantons (about 20 excess deaths/100,000 people/day) than in the least deprived Cantons (about 10 excess deaths/100,000 people/day). No such interaction was observed for the rest of France, which was less exposed to heat and less heterogeneous in terms of deprivation. Although a marked increase in mortality was associated with heat wave exposure for all degrees of deprivation, deprivation appears to be a vulnerability factor with respect to heat-wave-associated mortality.

  19. In-situ observation of deuteride formation in palladium electrochemical cathode by X-ray diffraction method

    International Nuclear Information System (INIS)

    Yamamoto, Takao; Oka, Takashi; Taniguchi, Ryoichi

    1990-01-01

    In-situ X-ray diffraction observation of palladium foil cathode (10 μm) was carried out during electrolysis of 0.1N-LiOD heavy water solution in order to estimate the deuterium content in palladium during the detection of charged particles in our previous work. A complete transformation into β-palladium deuteride phase was observed, and its maximum lattice constant 4.06 A was evaluated as corresponding to D/Pd = 0.73. The deuterium concentration in the previous work was estimated as higher than this considering the difference in cell conditions. (author)

  20. Sol-gel synthesized of nanocomposite palladium-alumina ceramic membrane for H{sub 2} permeability: Preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, A.L.; Mustafa, N.N.N. [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Penang (Malaysia)

    2007-08-15

    Palladium-alumina membrane with mesopore and narrow pore size distribution was prepared by the sol-gel method. Effect of the finely dispersed metal on the microstructure and the characteristic properties of the palladium-alumina membrane were investigated. Observations were made on membrane weight loss, morphology, pore structure, pore size, surface area, pore surface fractal and membrane's crystal structure. Autosorb analysis, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) analysis were employed in the membrane characterization. Autosorb analysis found that, BET surface area decreased and pore size of the membrane increased with the increasing of calcinations temperature (500-1100{sup o}C) and with the increasing of palladium amount in the membrane. FTIR and TG/DTA analysis show that the suitable temperature for calcinations of palladium-alumina membrane is at 700{sup o}C. Palladium metals are highly dispersed at calcinations temperature of 700{sup o}C as observed by TEM analysis. The fine crystallinity of the palladium and {gamma}-alumina phase was obtained after calcined at 700{sup o}C. The SEM morphology shows a smooth and free crack layer of palladium-alumina membrane after repeating the process of dipping, drying and calcinations at temperature of 700{sup o}C. The membrane also successfully coated with a good adhesion on support. The thickness of the final membrane layer was estimated as 9{mu} m. (author)

  1. Palladium coated fibre Bragg grating based hydrogen sensor

    International Nuclear Information System (INIS)

    Kasinathan, M.; Sosamma, S.; Kishore, S.; Elumalai, V.; Krishnan, R.; Babu Rao, C.; Dash, Sitaram; Murali, N.; Jayakumar, T.

    2011-01-01

    Detection of steam generator leaks in fast nuclear reactors is carried out by monitoring hydrogen in argon cover-gas. Hydrogen released during sodium cleaning of fast reactor components is required to be monitored. Hydrogen sensors with good sensitivity, stability and response time are required for all the above applications. We report a new type of hydrogen sensor with a Fibre Bragg Grating (FBG) coated with palladium thin film which is used to detect the leak of hydrogen gas in the Steam Generator (SG) module of the Fast Breeder Reactor (FBR). If water leaks into sodium, it results in sodium-water reaction. In this reaction hydrogen and sodium hydroxide are formed. Due to the explosive risk of hydrogen system, hydrogen sensors are of great interest in this case. It is known that hydrogen forms an explosive mixture with air once its concentration exceeds beyond the explosion limit of four percent. The advantages of FBG based hydrogen sensor over the other hydrogen sensors are its inherent property of safety from sparking, immunity to ambient electromagnetic interference. The sensing mechanism in this device is based on mechanical strain that is induced in the palladium coating when it absorbs hydrogen. This process physically stretches the grating and causes the grating period and grating's refractive index, to change. The Bragg wavelength shift is directly proportional to the strain induced and can be directly related to the percentage of hydrogen exposure. The online monitoring of palladium thin film coating on FBG is carried out and recorded the wavelength change and strain induced on the FBG. A hydrogen sensor set up have been fabricated which consists of SS vessel of capacity 10 litres, provided with pressure gauge, Argon filling line with a valve, Hydrogen injection line with flange, a vent line with valve and Hydrogen sensor fixing point. The Palladium coated FBG based Hydrogen sensor is tested in this experimental facility in the exposure of hydrogen in

  2. Correction of Excessive Precipitation over Steep Mountains in a General Circulation Model (GCM)

    Science.gov (United States)

    Chao, Winston C.

    2012-01-01

    Excessive precipitation over steep and high mountains (EPSM) is a well-known problem in GCMs and regional climate models even at a resolution as high as 19km. The affected regions include the Andes, the Himalayas, Sierra Madre, New Guinea and others. This problem also shows up in some data assimilation products. Among the possible causes investigated in this study, we found that the most important one, by far, is a missing upward transport of heat out of the boundary layer due to the vertical circulations forced by the daytime subgrid-scale upslope winds, which in turn is forced by heated boundary layer on the slopes. These upslope winds are associated with large subgrid-scale topographic variance, which is found over steep mountains. Without such subgrid-scale heat ventilation, the resolvable-scale upslope flow in the boundary layer generated by surface sensible heat flux along the mountain slopes is excessive. Such an excessive resolvable-scale upslope flow in the boundary layer combined with the high moisture content in the boundary layer results in excessive moisture transport toward mountaintops, which in turn gives rise to excessive precipitation over the affected regions. We have parameterized the effects of subgrid-scale heated-slope-induced vertical circulation (SHVC) by removing heat from the boundary layer and depositing it in the layers higher up when topographic variance exceeds a critical value. Test results using NASA/Goddard's GEOS-5 GCM have shown that the EPSM problem is largely solved.

  3. Controlled immobilization of palladium nanoparticles in two different fluorinated polymeric aggregate cores and their application in catalysis

    DEFF Research Database (Denmark)

    Kijima, Tetsushi; Javakhishvili, Irakli; Jankova Atanasova, Katja

    2012-01-01

    Fluoroalkyl end-capped betaine-type cooligomeric nanocomposites-immobilized palladium nanoparticles were prepared by the reactions of palladium chloride with sodium acetate in the presence of sodium chloride and the corresponding fluorinated cooligomers. Outer blocks of poly(2,3,4,5,6-pentafluoro....... These fluorinated nanocomposites-immobilized palladium nanoparticles were also applied to the catalysts for Suzuki-Miyaura cross-coupling reaction, and the different reactivity between these nanocomposites was observed....

  4. Analysis of the anomalous hydrogen solubilities in deformed palladiums

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choong Nyeon; Lee, Ho Jong

    1987-02-01

    The anomalous hydrogen solubilities in the deformed palladiums were analyzed by empolying modified Kirchheim's model with considering the partially coherent strain energy which would induced during hydride precipitation around edge dislocations. The dislocation densities, obtained by this model, of the various cold worked and/or reversible US transformed palladium samples were the order of 10/sup 11/cm/sup -2/. The partially coherent strain energies were about 3 kJ/molH and nearly same in the various samples. This value could be compared with the incoherent strain energy, 0.4kJ/molH, which was obtained from the hysteresis on P-C isotherm, and the coherent strain energy calulated, 9.6kJ/molH.

  5. Activation and deactivation of neutral palladium(II) phosphinesulfonato polymerization catalysts

    KAUST Repository

    Rünzi, Thomas

    2012-12-10

    13C-Labeled ethylene polymerization (pre)catalysts [κ2-(anisyl)2P,O]Pd(13CH3)(L) (1-13CH3-L) (L = pyridine, dmso) based on di(2-anisyl)phosphine benzenesulfonate were used to assess the degree of incorporation of 13CH3 groups into the formed polyethylenes. Polymerizations of variable reaction time reveal that ca. 60-85% of the 13C-label is found in the polymer after already 1 min polymerization time, which provides evidence that the pre-equilibration between the catalyst precursor 1-13CH3-L and the active species 1-13CH3-(ethylene) is fast with respect to chain growth. The fraction of 1-13CH3-L that initiates chain growth is likely higher than the 60-85% determined from the 13C-labeled polymer chain ends since (a) chain walking results in in-chain incorporation of the 13C-label, (b) irreversible catalyst deactivation by formation of saturated (and partially volatile) alkanes diminishes the amount of 13CH3 groups incorporated into the polymer, and (c) palladium-bound 13CH3 groups, and more general palladium-bound alkyl(polymeryl) chains, partially transfer to phosphorus by reductive elimination. NMR and ESI-MS analyses of thermolysis reactions of 1-13CH3-L provide evidence that a mixture of phosphonium salts (13CH3)xP+(aryl)4-x (2-7) is formed in the absence of ethylene. In addition, isolation and characterization of the mixed bis(chelate) palladium complex [κ2-(anisyl)2P,O]Pd[κ2-(anisyl) (13CH3)P,O] (11) by NMR and X-ray diffraction analyses from these mixtures indicate that oxidative addition of phosphonium salts to palladium(0) species is also operative. The scrambling of palladium-bound carbyls and phosphorus-bound aryls is also relevant under NMR, as well as preparative reactor polymerization conditions exemplified by the X-ray diffraction analysis of [κ2-(anisyl)2P,O] Pd[κ2-(anisyl)(CH2CH3)P,O] (12) and [κ2-(anisyl)2P,O]Pd[κ2-(anisyl) ((CH2)3CH3)P,O] (13) isolated from pressure reactor polymerization experiments. In addition, ESI-MS analyses of reactor

  6. Engineering Defect-Free Nanoporous Pd from Optimized Pd-Ni Precursor Alloy by Understanding Palladium-Hydrogen Interactions During Dealloying

    Science.gov (United States)

    Schoop, Julius; Balk, T. John

    2014-04-01

    Thin films of nanoporous palladium (np-Pd) were produced from binary palladium-nickel (Pd-Ni) precursor alloys. A suitable precursor alloy and a method of dealloying to yield optimum nanoporosity (average pore/ligament size of 7 nm) were developed by studying the effects of various processing parameters on final microstructure. To obtain crack-free np-Pd, a 100 nm thin film of 20 at. pct Pd (80 at. pct Ni) can be dealloyed for ~5 hours in a 1 M solution of sulfuric acid, with oleic acid and oleylamine added as surfactants. Both shorter and longer dealloying times, as well as heating, inhibit the formation of crack-free np-Pd. Stress measurements at different stages of dealloying revealed that the necessary dealloying time is determined by the diffusion-controlled corrosion reaction occurring within the thin film during dealloying. Strong interaction between hydrogen and np-Pd was reflected in the stress evolution during dealloying. A mechanism is proposed for the formation of a Ni-rich dense top layer that results from H-induced swelling during initial dealloying and permits the development of defect-free np-Pd beneath, by limiting the speed of dealloying.

  7. Tetradentate N2O2 Chelated Palladium(II Complexes: Synthesis, Characterization, and Catalytic Activity towards Mizoroki-Heck Reaction of Aryl Bromides

    Directory of Open Access Journals (Sweden)

    Siti Kamilah Che Soh

    2013-01-01

    Full Text Available Four air and moisture-stable palladium(II-Schiff base complexes, N,N′-bis(α-methylsalicylidenepropane-1,3-diamine palladium(II (2a, N,N′-bis(4-methyl-α-methylsalicylidenepropane-1,3-diamine palladium(II (2b, N,N′-bis(3,5-di-tert-butylsalicylidenepropane-1,3-diamine palladium(II (2c, and N,N′-bis(4-methoxy-salicylidenepropane-1,3-diamine palladium(II (2d, have been successfully synthesised and characterised by CHN elemental analyses and conventional spectroscopic methods. These complexes were investigated as catalysts in the phosphine-free Mizoroki-Heck cross-coupling reactions of aryl bromides with methyl acrylate.

  8. Copper-based electrochemical sensor with palladium electrode for cathodic stripping voltammetry of manganese.

    Science.gov (United States)

    Kang, Wenjing; Pei, Xing; Bange, Adam; Haynes, Erin N; Heineman, William R; Papautsky, Ian

    2014-12-16

    In this work, we report on the development of a palladium-based, microfabricated point-of-care electrochemical sensor for the determination of manganese using square wave cathodic stripping voltammetry. Heavy metals require careful monitoring, yet current methods are too complex for a point-of-care system. Voltammetry offers an attractive approach to metal detection on the microscale, but traditional carbon, gold, or platinum electrodes are difficult or expensive to microfabricate, preventing widespread use. Our sensor uses palladium working and auxiliary electrodes and integrates them with a copper-based reference electrode for simple fabrication and compatibility with microfabrication and printed circuit board processing, while maintaining competitive performance in electrochemical detection. Copper electrodes were prepared on glass substrate using a combination of microfabrication procedures followed by electrodeposition of palladium. The disposable sensor system was formed by bonding a poly(dimethylsiloxane) (PDMS) well to the glass substrate. Cathodic stripping voltammetry of manganese using our new disposable palladium-based sensors exhibited 334 nM (18.3 ppb) limit of detection in borate buffer. The sensor was used to demonstrate manganese determination in natural water samples from a pond in Burnet Woods, located in Cincinnati, OH, and the Ohio River.

  9. Green synthesis of palladium nanoparticles with carboxymethyl cellulose for degradation of azo-dyes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gang; Li, Yun; Wang, Zhengdong; Liu, Huihong, E-mail: huihongliu@126.com

    2017-02-01

    Palladium nanoparticles (PdNPs) were synthesized through friendly environmental method using PdCl{sub 2} and carboxymethyl cellulose (CMC) in an aqueous solution (pH 6) at controlled water bath (80 °C) for 30 min. CMC functioned as both reducing and stabilizing agent. The characterization through high resolution-transmission electron microscopic (HRTEM) and X-ray Fluorescence Spectrometry (XRF) inferred that the as-synthesized PdNPs were spherical in shape with a face cubic crystal (FCC) structure. The results from dynamic light scattering (DLS) suggested the PdNPs had the narrow size distribution with an average size of 2.5 nm. The negative zeta potential (−52.6 mV) kept the as-synthesized PdNPs stable more than one year. The PdNPs showed the excellent catalytic activity by reducing degradation of azo-dyes, such as p-Aminoazobenzene, acid red 66, acid orange 7, scarlet 3G and reactive yellow 179, in the present of sodium borohydride. - Highlights: • Green synthesis of palladium nanoparticles using carboxymethyl cellulose. • The synthesis of palladium nanoparticles were performed easily. • Carboxymethyl cellulose acts as both reducing and stabilization agents. • The as-synthesized palladium nanoparticles show excellent catalytic activity.

  10. Specific heat, polarization and heat conduction in microwave heating systems: A nonequilibrium thermodynamic point of view

    International Nuclear Information System (INIS)

    Bergese, Paolo

    2006-01-01

    A microwave (MW) field can induce in a dielectric material an oscillatory polarization. By this mechanism part of the energy carried by the waves is converted into chaotic agitation, and the material heats up. MW heating is a nonequilibrium phenomenon, while conventional heating can generally be considered as quasi-static. Excess (or nonthermal) effects of MWs with respect to conventional heating lie in this difference. Macroscopically, MW heating can be described in the framework of linear nonequilibrium thermodynamics (NET). This approach indicates that in a dielectric material under MW heating the specific heat has a dynamic component linked to the variation of polarization with temperature, and that polarization and heat conduction are intertwined. In particular, linear NET provides a new phenomenological equation for heat conduction that is composed of the classic Fourier's law and an additional term due to polarization relaxation. This term quantitatively describes the excess effect of MWs on thermal conduction

  11. Formation of palladium hydrides in low temperature Ar/H{sub 2}-plasma

    Energy Technology Data Exchange (ETDEWEB)

    Wulff, H., E-mail: wulff@uni-greifswald.de [University of Greifswald, Institute of Physics, Felix-Hausdorff-Straße 6, 17487 Greifswald (Germany); Quaas, M. [LITEC-LP, Brandteichstraße 20, 17489 Greifswald (Germany); Deutsch, H.; Ahrens, H. [University of Greifswald, Institute of Physics, Felix-Hausdorff-Straße 6, 17487 Greifswald (Germany); Fröhlich, M. [Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2 (Germany); Helm, C.A. [University of Greifswald, Institute of Physics, Felix-Hausdorff-Straße 6, 17487 Greifswald (Germany)

    2015-12-01

    20 nm thick Pd coatings deposited on Si substrates with 800 nm SiO{sub 2} and 1 nm Cr buffer layers were treated in a 2.45 GHz microwave plasma source at 700 W plasma power and 40 Pa working pressure without substrate heating. For obtaining information on the effect of energy influx due to ion energy on the palladium films the substrate potential was varied from U{sub sub} = 0 V to − 150 V at constant gas flow corresponding to mean ion energies E{sub i} from 0.22 eV ∙ cm{sup −2} ∙ s{sup −1} to 1.28 eV ∙ cm{sup −2} ∙ s{sup −1}. In contrast to high pressure reactions with metallic Pd, under plasma exposure we do not observe solid solutions over a wide range of hydrogen concentration. The hydrogen incorporation in Pd films takes place discontinuously. At 0 V substrate voltage palladium hydride is formed in two steps to PdH{sub 0.14} and PdH{sub 0.57}. At − 50 V substrate voltage PdH{sub 0.57} is formed directly. However, substrate voltages of − 100 V and − 150 V cause shrinking of the unit cell. We postulate the formation of two fcc vacancy palladium hydride clusters PdH{sub Vac}(I) and PdH{sub Vac}(II). Under longtime plasma exposure the fcc PdH{sub Vac}(II) phase forms cubic PdH{sub 1.33}. The fcc PdH{sub 0.57} phase decomposes at temperatures > 300 °C to form metallic fcc Pd. The hydrogen removal causes a decrease of lattice defects. In situ high temperature diffractometry measurements also confirm the existence of PdH{sub Vac}(II) as a palladium hydride phase. Stoichiometric relationship between cubic PdH{sub 1.33} and fcc PdH{sub Vac}(II) becomes evident from XR measurements and structure considerations. We assume both phases have the chemical composition Pd{sub 3}H{sub 4}. Up to 700 °C we observe phase transformation between both the fcc PdH{sub Vac}(II) and cubic PdH{sub 1.33} phases. These phase transformations could be explained analog to a Bain distortion by displacive solid state structural changes. - Highlights: • Thin Pd films

  12. Study on the determination of palladium in biological samples by the method of neutron activation analysis

    International Nuclear Information System (INIS)

    Cavalcante, Cassio Queiroz

    2007-01-01

    Palladium is one of platinum group elements present in the nature at very low concentrations. However with the use of this element in the automobile catalyzers Pd became a new pollutant. Besides, Pd has been studied in the preparation of new antitumour drugs. Consequently, there is a need to determine Pd concentrations in biological and environmental samples. This study presents palladium results obtained in the analysis of biological samples and reference materials using instrumental thermal and epithermal neutron activation analysis (INAA and ENAA). The solvent extraction and solid phase extraction separation methods were also applied before ENAA. The samples analyzed in this study were, reference material BCR 723 - Palladium, Platinum and Rhodium in road dust, CCQM-P63 automotive catalyst material of the Proficiency Test and bovine tissue samples containing palladium prepared in the laboratory. Samples and palladium synthetic standard were irradiated at the IEA-R1 nuclear research reactor under thermal neutron flux of about 4 x 10 12 n cm-2 s-1, during a period of 4 and 16 h for INAA and ENAA, respectively. The induced gamma activity of 109 Pd to the sample and standard was measured using a hyper pure Ge detector coupled to a gamma ray spectrometer. The palladium concentration was calculated by comparative method. The gamma ray energy of 109 Pd radioisotope measured was of 88.0 keV, located in a spectrum region of low energy where occurs the interference of X rays, 'Bremsstrahlung' radiations, as well as Compton effect of 24 Na. The pre-separation of palladium from interfering elements by solvent extraction was performed using dimethylglyoxime complexant and chloroform as diluent. In the case of the pre separation procedure using solid reversed phase column, the palladium was retained using N,N-diethyl-N'-benzoyl thiourea complexant and eluted using ethanol. Aliquots of the resulting solutions from the pre-separations, free of interfering elements, were

  13. Palladium alloy membrane process for the treatment of hydrogen isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Hongsuk; Paek, Seungwoo; Lee, Minsoo; Kim, Kwangrag; Yim, Sungpaal; Ahn, Dohee [KAERI, Daejeon (Korea, Republic of); Shim, Myunghwa [Univ. of Science and Technology, Daejeon (Korea, Republic of)

    2005-11-15

    Tritium is a radioactive isotope of hydrogen and it has a half-life of 12.3 years; it decays to He-3 by emitting a low energy beta radiation with an average energy of 5.7 keV and a maximum energy of 18.6 keV. Transfer of environmentally tritiated water to humans takes place via an inhalation, diffusion through the skin and ingestion. Radioactive waste containing tritium is continuously generated by the nuclear industry in, for example, nuclear reactor operations and a radioisotope production, as well as in medical research. Methods for removing tritium from liquid waste provide an alternative to the control of tritium emissions and a personnel exposure. A combined electrolysis and catalytic exchange process is a very effective method to remove small quantities of tritium from light or heavy waste water streams. The process consists of three main steps: (a) A front end step that exchanges the tritium to a less toxic hydrogen phase. This can be performed either through a chemical exchange in the presence of a platinum supported catalyst or through the decomposition of water. (b) A back end process that purifies the tritiated hydrogen gas which evolved from the electrolysis. This can be performed through a palladium alloy membrane separator. (c) A means of storing the concentrated gas safely. Uranium is used if the storage is temporary; titanium is usually employed for long term storage. To gain a better understanding of the tritiated hydrogen gas purification process, a mathematical model of the palladium alloy membrane has been used. This model is described herein, and the representative results of the model calculations are presented. The authors selected the palladium alloy membrane for the hydrogen purification process by considering the membrane properties, such as a chemical resistance, mechanical stability, thermal stability, high permeability, and a stable operation. The solution-diffusion model can be a useful tool for designing a membrane permeator. The

  14. Palladium alloy membrane process for the treatment of hydrogen isotopes

    International Nuclear Information System (INIS)

    Chung, Hongsuk; Paek, Seungwoo; Lee, Minsoo; Kim, Kwangrag; Yim, Sungpaal; Ahn, Dohee; Shim, Myunghwa

    2005-01-01

    Tritium is a radioactive isotope of hydrogen and it has a half-life of 12.3 years; it decays to He-3 by emitting a low energy beta radiation with an average energy of 5.7 keV and a maximum energy of 18.6 keV. Transfer of environmentally tritiated water to humans takes place via an inhalation, diffusion through the skin and ingestion. Radioactive waste containing tritium is continuously generated by the nuclear industry in, for example, nuclear reactor operations and a radioisotope production, as well as in medical research. Methods for removing tritium from liquid waste provide an alternative to the control of tritium emissions and a personnel exposure. A combined electrolysis and catalytic exchange process is a very effective method to remove small quantities of tritium from light or heavy waste water streams. The process consists of three main steps: (a) A front end step that exchanges the tritium to a less toxic hydrogen phase. This can be performed either through a chemical exchange in the presence of a platinum supported catalyst or through the decomposition of water. (b) A back end process that purifies the tritiated hydrogen gas which evolved from the electrolysis. This can be performed through a palladium alloy membrane separator. (c) A means of storing the concentrated gas safely. Uranium is used if the storage is temporary; titanium is usually employed for long term storage. To gain a better understanding of the tritiated hydrogen gas purification process, a mathematical model of the palladium alloy membrane has been used. This model is described herein, and the representative results of the model calculations are presented. The authors selected the palladium alloy membrane for the hydrogen purification process by considering the membrane properties, such as a chemical resistance, mechanical stability, thermal stability, high permeability, and a stable operation. The solution-diffusion model can be a useful tool for designing a membrane permeator. The

  15. Sulphur containing novel extractants for extraction-separation of palladium (II)

    International Nuclear Information System (INIS)

    Shukla, J.P.; Sawant, S.R.; Anil Kumar; Singh, R.K.

    1995-01-01

    Extraction performance of palladium (II) by sulphur containing extragents has unequivocally established their strong extraction ability toward this thiophilic soft metal. Hence a comprehensive investigative study was initiated by us to examine selective reversible extraction-separation of trace and macro amounts of palladium (II) from both aqueous nitric acid as well as hydrochloric acid media into 1,2-dichloroethane by 1,10-dithia-18 crown-6 (1,10-DT18C6), S 6 -pentano-36 (S 6 -P-36) and bis (2-ethylhexyl) sulphoxide (BESO) dissolved in toluene. From the study of aqueous phase acidity, reagent concentration, period of equilibration, diluent, strippant and diverse ions, conditions are established from its quantitative and reversible extraction. Recovery of Pd(II) from loaded thiacrown and sulphoxide phase is easily accomplished by using sodium thiocyanate, ammonium thiocyanate, thiourea, sodium thiosulphate and mixture of (2M Na 2 CO 3 + 0.5 NH 4 OH) (only for BESO) as the strippants. The lack of interference from even appreciable amounts of contaminants like 137 Cs, 106 Ru, 233 U and 239 Pu may be considered as one of the outstanding advantages of the method. Application of these extractants has been successfully tested for the recovery of palladium from high active waste matrix. The extracted complex from both the thiacrowns has been characterized by elemental analyses and UV-Visible spectra, confirmed to be PdA 2 .T (A = NO - 3 , Cl - ) from dilute (pH ∼ 2) acid solutions while composition of organic species with palladium for the sulphoxide, has also been confirmed to be disolvate of the type Pd(NO 3 ) 2 .2BESO. (author). 52 refs., 6 tabs., 6 figs

  16. Study on a multi-component palladium alloy membrane for the fusion fuel cycle

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi; Okuno, Kenji; Nagasaki, Takanori; Noda, Kenji; Ishii, Yoshinobu; Takeshita, Hidefumi.

    1985-11-01

    A feasibility study on the material integrity with respect to the hydride formation and helium damage of the palladium alloy membrane was performed for an application of the palladium diffuser to a fusion fuel cleanup process. This study was conducted under the Japan/US Fusion Cooperation Program. Experimental works on the crystallography, hydrogen solubility and 3 He release characteristics were carried out with a multi-component palladium alloy(Pd-25Ag.Au.Ru). The excellent hydrogen permeability and mechanical properties of the membrane made of this alloy had been confirmed by authors' previous study. Based on the present study, this alloy membrane has high resistivity to the hydrogen embrittlement, and swelling and fracture due to the helium bubble formation under the practical operating conditions of the diffuser. (author)

  17. Chiral separation of substituted phenylalanine analogues using chiral palladium phosphine complexes with enantioselective liquid-liquid extraction

    NARCIS (Netherlands)

    Verkuijl, B.J.V.; Schuur, B.; Minnaard, A.J.; Vries, de J.G.; Feringa, B.L.

    2010-01-01

    Chiral palladium phosphine complexes have been employed in the chiral separation of amino acids and phenylalanine analogues in particular. The use of (S)-xylyl-BINAP as a ligand for the palladium complex in enantioselective liquid–liquid extraction allowed the separation of the phenylalanine

  18. Hydrogenation of carbon monoxide over supported palladium catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, K.; Hashimoto, H.; Kunugi, T.

    1978-03-01

    An alumina-supported 2% palladium catalyst had higher activity for carbon monoxide hydrogenation than a silica-supported 2% palladium catalyst, at 250/sup 0/-400/sup 0/C and 1 atm. The addition of lanthanum oxide or thorium oxide, but not of potassium oxide, to the silica-supported catalyst increased the conversion at 350/sup 0/C from 1.1% to 81.0% with a selectivity of 56.1% for methane, 1.4% for C/sub 2/ compounds, 0.1% for C/sub 3/ compounds, and 42.5% for carbon dioxide. Temperature-programed desorption of carbon monoxide in a hydrogen stream showed that of two desorption peaks observed for carbon monoxide, the one at higher temperature corresponded to the carbon monoxide species which hydrogenates to methane and that the area of this peak increased with increasing thorium content of the catalyst. Graphs, tables, and 12 references.

  19. Method for palladium activating molybdenum metallized features on a ceramic substrate

    International Nuclear Information System (INIS)

    Kumar, A.H.; Schwartz, B.

    1985-01-01

    A molybdenum or tungsten metallurgical pattern is formed on or in a dielectric green sheet. Palladium, nickel, platinum or rhodium is coated on a layer of polyvinyl butyral which is carried on a polyester film. The metal layer of this assembly is laminated to a dielectric green sheet which carries the molybdenum or tungsten metallurgy. The polyester film is stripped off. The resulting assembly is sintered to a fired structure, whereby the polyvinyl butyral is volatilized off and the palladium, nickel, platinum or rhodium is alloyed with the molybdenum or tungsten metallurgy to provide a densified metallurgy whose surface is free of glass

  20. Determination of palladium by flame photometry; Determinacion de paladio por fotometria de llama

    Energy Technology Data Exchange (ETDEWEB)

    Parallada Bellod, R

    1964-07-01

    A study on the determination of palladium by lame photometry, fixing the most convent experimental conditions and using solvents to increase the emission of this elements is carried out. Among the organic solvents, acetone has been found the most efficient. The interferences produced by anions and cations have also been studied and an analytical method is related, in which lines of calibration of 0 to 100 ppm palladium re used. (Author) 7 refs.

  1. Optical properties of palladium nanoparticles under exposure of hydrogen and inert gas prepared by dewetting synthesis of thin-sputtered layers

    Energy Technology Data Exchange (ETDEWEB)

    Kracker, Michael, E-mail: Michael.Kracker@uni-jena.de; Worsch, Christian; Ruessel, Christian [Otto-Schott-Institut, Jena University (Germany)

    2013-04-15

    Thin layers of palladium with a thickness of 5 nm were sputtered on fused silica substrates. Subsequently, the coated glasses were annealed at a temperature of 900 Degree-Sign C for 1 h. This resulted in the formation of small and well-separated palladium nanoparticles with diameters in the range from 20 to 200 nm on the glass surface. The existence of a palladium oxide layer can be detected using optical absorption spectroscopy. Purging with hydrogen leads to an irreversible change in the optical spectra due to the reduction of PdO to metallic palladium. Changing the gas atmosphere from hydrogen to argon leads to significant reversible changes in the optical properties of the particle layer. Based on Mie theory and the respective dielectric functions, the spectra were calculated using the real particle size distribution, weighted dispersions relation to adapt the geometrical conditions and complex dielectric functions of palladium and palladium hydride. A good agreement with measured spectra was found and the dependency of the surrounding media can be explained.Graphical Abstract.

  2. Excess mortality during the warm summer of 2015 in Switzerland.

    Science.gov (United States)

    Vicedo-Cabrera, Ana M; Ragettli, Martina S; Schindler, Christian; Röösli, Martin

    2016-01-01

    In Switzerland, summer 2015 was the second warmest summer for 150 years (after summer 2003). For summer 2003, a 6.9% excess mortality was estimated for Switzerland, which corresponded to 975 extra deaths. The impact of the heat in summer 2015 in Switzerland has not so far been evaluated. Daily age group-, gender- and region-specific all-cause excess mortality during summer (June-August) 2015 was estimated, based on predictions derived from quasi-Poisson regression models fitted to the daily mortality data for the 10 previous years. Estimates of excess mortality were derived for 1 June to 31 August, at national and regional level, as well as by month and for specific heat episodes identified in summer 2015 by use of seven different definitions. 804 excess deaths (5.4%, 95% confidence interval [CI] 3.0‒7.9%) were estimated for summer 2015 compared with previous summers, with the highest percentage obtained for July (11.6%, 95% CI 3.7‒19.4%). Seventy-seven percent of deaths occurred in people aged 75 years and older. Ticino (10.3%, 95% CI -1.8‒22.4%), Northwestern Switzerland (9.5%, 95% CI 2.7‒16.3%) and Espace Mittelland (8.9%, 95% CI 3.7‒14.1%) showed highest excess mortality during this three-month period, whereas fewer deaths than expected (-3.3%, 95% CI -9.2‒2.6%) were observed in Eastern Switzerland, the coldest region. The largest excess estimate of 23.7% was obtained during days when both maximum apparent and minimum night-time temperature reached extreme values (+32 and +20 °C, respectively), with 31.0% extra deaths for periods of three days or more. Heat during summer 2015 was associated with an increase in mortality in the warmer regions of Switzerland and it mainly affected older people. Estimates for 2015 were only a little lower compared to those of summer 2003, indicating that mitigation measures to prevent heat-related mortality in Switzerland have not become noticeably effective in the last 10 years.

  3. Palladium on Carbon-Catalyzed Suzuki-Miyaura Coupling Reaction Using an Efficient and Continuous Flow System

    Directory of Open Access Journals (Sweden)

    Tomohiro Hattori

    2015-01-01

    Full Text Available The continuous flow Suzuki-Miyaura reaction between various haloarenes and arylboronic acids was successfully achieved within only ca. 20 s during the single-pass through a cartridge filled with palladium on carbon (Pd/C. No palladium leaching was observed in the collected reaction solution by atomic absorption spectrometry (detection limit: 1 ppm.

  4. Behavior of palladium and its impact on intermetallic growth in palladium-coated Cu wire bonding

    International Nuclear Information System (INIS)

    Xu Hui; Qin, Ivy; Clauberg, Horst; Chylak, Bob; Acoff, Viola L.

    2013-01-01

    This paper describes the behavior of palladium in palladium-coated Cu (PdCu) wire bonding and its impact on bond reliability by utilizing transmission electron microscopy (TEM). A Pd layer approximately 80 nm thick, which is coated on the surface of Cu wire, dissolves into the Cu matrix during ball formation (under N 2 gas protection) when the wire tip is melted to form a ball. As a result of dissolving the very thin Pd layer into the ball, Pd is almost undetectable along the entire bond interface between the ball and the Al pad. The behavior of Pd during thermal aging in air, however, is different for central and peripheral interfaces. At the central interface, less than 5 at.% Pd is present after 168 h aging at 175 °C. At the periphery, however, Pd diffuses back and congregates, reaching a level of ∼12 at.% after 24 h, and a Pd-rich (Cu,Pd) 9 Al 4 layer (>40 at.% Pd) forms after 168 h. Pd acts substitutionally in Cu 9 Al 4 but cannot penetrate into the CuAl 2 or CuAl. By comparison of intermetallic thickness and interfacial morphology between PdCu and bare Cu wire bonds, it is concluded that the presence of Pd reduces intermetallic growth rate, and is associated with numerous nanovoids in PdCu bonds.

  5. Tritium evolution from various morphologies of palladium

    International Nuclear Information System (INIS)

    Tuggle, D.G.; Claytor, T.N.; Taylor, S.F.

    1994-01-01

    The authors have been able to extend the tritium production techniques to various novel morphologies of palladium. These include small solid wires of various diameters and a type of pressed powder wire and a plasma cell. In most successful experiments, the amount of palladium required, for an equivalent tritium output, has been reduced by a factor of 100 over the older powder methods. In addition, they have observed rates of tritium production (>5 nCi/h) that far exceed most of the previous results. Unfortunately, the methods that they currently use to obtain the tritium are poorly understood and consequently there are numerous variables that need to be investigated before the new methods are as reliable and repeatable as the previous techniques. For instance, it seems that surface and/or bulk impurities play a major role in the successful generation of any tritium. In those samples with total impurity concentrations of >400 ppM essentially no tritium has been generated by the gas loading and electrical simulation methods

  6. Palladium-catalyzed allylation of tautomerizable heterocycles with alkynes.

    Science.gov (United States)

    Lu, Chuan-Jun; Chen, Dong-Kai; Chen, Hong; Wang, Hong; Jin, Hongwei; Huang, Xifu; Gao, Jianrong

    2017-07-21

    A method for the allylic amidation of tautomerizable heterocycles was developed by a palladium catalyzed allylation reaction with 100% atom economy. A series of structurally diverse N-allylic substituted heterocycles can be synthesized in good yields with high chemo-, regio-, and stereoselectivities under mild conditions.

  7. Fractal analysis of electrolytically-deposited palladium hydride dendrites

    International Nuclear Information System (INIS)

    Bursill, L.A.; Julin, Peng; Xudong, Fan.

    1990-01-01

    The fractal scaling characteristics of the surface profile of electrolytically-deposited palladium hydride dendritic structures have been obtained using conventional and high resolution transmission electron microscopy. The results are in remarkable agreement with the modified diffusion-limited aggregation model. 19 refs., 3 tabs., 13 figs

  8. Antibacterial properties of palladium nanostructures sputtered on polyethylene naphthalate

    Czech Academy of Sciences Publication Activity Database

    Polívková, M.; Válová, M.; Siegel, J.; Rimpelová, S.; Hubáček, Tomáš; Lyutakov, O.; Švorčík, V.

    2015-01-01

    Roč. 5, č. 90 (2015), s. 73767-73774 ISSN 2046-2069 Institutional support: RVO:60077344 Keywords : polymer * palladium sputtering * annealing * nanostructure * antibacterial effect Subject RIV: JJ - Other Materials Impact factor: 3.289, year: 2015

  9. QuadraPure-Supported Palladium Nanocatalysts for Microwave-Promoted Suzuki Cross-Coupling Reaction under Aerobic Condition

    Directory of Open Access Journals (Sweden)

    Kin Hong Liew

    2014-01-01

    Full Text Available Cross-linked resin-captured palladium (XL-QPPd was readily prepared by simple physical adsorption onto the high loading QuadraPure macroporous resin and a subsequent reduction process. To enhance the mechanical stability, entrapped palladium nanocatalysts were cross-linked with succinyl chloride. Both transmission electron microscopy images and X-ray diffraction analysis revealed that the palladium nanoparticles were well dispersed with diameters ranging in 4–10 nm. The catalyst performed good catalytic activity in microwave-promoted Suzuki cross-coupling reactions in water under aerobic condition with mild condition by using various aryl halides and phenylboronic acid. In addition, the catalyst showed an excellent recyclability without significant loss of catalytic activity.

  10. Structural Characterizations of Palladium Clusters Prepared by Polyol Reduction of [PdCl4]2− Ions

    Directory of Open Access Journals (Sweden)

    Loredana Schiavo

    2016-01-01

    Full Text Available Palladium nanoparticles are of great interest in many industrial fields, ranging from catalysis and hydrogen technology to microelectronics, thanks to their unique physical and chemical properties. In this work, palladium clusters have been prepared by reduction of [PdCl4]2− ions with ethylene glycol, in the presence of poly(N-vinyl-2-pyrrolidone (PVP as stabilizer. The stabilizer performs the important role of nucleating agent for the Pd atoms with a fast phase separation, since palladium atoms coordinated to the polymer side-groups are forced at short distances during nucleation. Quasispherical palladium clusters with a diameter of ca. 2.6 nm were obtained by reaction in air at 90°C for 2 hours. An extensive materials characterization by transmission electron microscopy (TEM, X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, and other characterizations (TGA, SEM, EDS-SEM, and UV-Vis has been performed in order to evaluate the structure and oxidation state of nanopalladium.

  11. Excess molar volumes and isentropic compressibilities of binary ...

    Indian Academy of Sciences (India)

    Excess molar volume; binary liquid mixtures; isentropic compressibility; intermolecular interactions. ... mixtures are essential for fluid flow, mass flow and heat transfer processes in chemical ... Experimentally determined values of density(ρ).

  12. Neutron activation determination of gold and palladium using extraction by organic sulfides

    International Nuclear Information System (INIS)

    Gil'berg, Eh.N.; Torgov, V.G.; Verevkin, G.V.; AN SSSR, Novosibirsk. Inst. Neorganicheskoj Khimii)

    1978-01-01

    Compared are methods of gold determination in standard rock samples of the USA National Geological Service: a) extraction by solutions of dioctylsulfide and oil sulfides from irradiated samples; b) preliminary extraction by the above solfides with the following extract radiation; c) the method of isotope dilution with substoichiometry extraction. A possibility is studied to determine palladium in the sulfide extract with gold using the NaI(Tl) thin crystal scintillators. It is established that joint palladium and gold extraction permits to determine them in many natural products simultaneously

  13. Palladium-catalysed arylation of acetoacetate esters to yield 2-arylacetic acid esters

    CSIR Research Space (South Africa)

    Zeevaart, JG

    2004-05-24

    Full Text Available , was developed simultaneously by Hart- wig and Buchwald.5 Typically the tert-butyl ester of propionic acid is treated with an aryl halide (bromide or chloride) in the presence of a strong base, palladium and a bulky phosphine ligand or a bulky imidazolinium CO2t... novel palladium- catalysed conditions for the arylation of acetoacetate esters resulting in the formation of 2-arylacetic acid esters. When we attempted the arylation of tert-butyl aceto- acetate 1a with bromobenzene 2a using mild reaction conditions (K3...

  14. Adlayers of palladium particles and their aggregates on porous polypropylene hollow fiber membranes as hydrogenization contractors/reactors

    NARCIS (Netherlands)

    Volkov, V.V.; Lebedeva, V.I.; Petrova, I.V.; Bobyl, A.V.; Konnikov, S.G.; Roldughin, V.I.; Erkel, J. van; Tereshchenko, G.F.

    2011-01-01

    Principal approaches for the preparation of catalytic membrane reactors based on polymer membranes containing palladium nanoparticles and for the description of their characteristics are presented. The method for the development of adlayers composed of palladium nanoparticles and their aggregates on

  15. Exposure to nickel and palladium from dental appliances

    NARCIS (Netherlands)

    Ventura Da Cruz Rodrigues Milheiro, A.M.

    2015-01-01

    The application of a dental material into the oral cavity is not free of biological implications, as deterioration of the material will undoubtedly occur. The adverse health effects of palladium and nickel are well known and their immunologic cross-reactivity is well established. The aim of this

  16. Study of electroplated silver-palladium biofouling inhibiting coating

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Hilbert, Lisbeth Rischel; Schroll, Casper

    2008-01-01

    Biofouling can cause many undesirable effects in industrial and medical settings. In this study, a new biofouling inhibiting Ag-Pd surface was designed to form an inhibiting effect by itself. This design was based on silver combined with nobler palladium, both with catalytic properties. Owing to ...

  17. Effects of heat waves on daily excess mortality in 14 Korean cities during the past 20 years (1991-2010): an application of the spatial synoptic classification approach

    Science.gov (United States)

    Lee, Dae-Geun; Kim, Kyu Rang; Kim, Jiyoung; Kim, Baek-Jo; Cho, Chun-Ho; Sheridan, Scott C.; Kalkstein, Laurence S.; Kim, Ho; Yi, Seung-Muk

    2017-11-01

    The aims of this study are to explore the "offensive" summer weather types classified under the spatial synoptic classification (SSC) system and to evaluate their impacts on excess mortality in 14 Korean cities. All-cause deaths per day for the entire population were examined over the summer months (May-September) of 1991-2010. Daily deaths were standardized to account for long-term trends of subcycles (annual, seasonal, and weekly) at the mid-latitudes. In addition, a mortality prediction model was constructed through multiple stepwise regression to develop a heat-health warning system based on synoptic climatology. The result showed that dry tropical (DT) days during early summer caused excess mortality due to non-acclimatization by inhabitants, and moist tropical (MT) plus and double plus resulted in greater spikes of excess mortality due to extremely hot and humid conditions. Among the 14 Korean cities, highly excess mortality for the elderly was observed in Incheon (23.2%, 95%CI 5.6), Seoul (15.8%, 95%CI 2.6), and Jeonju (15.8%, 95%CI 4.6). No time lag effect was observed, and excess mortality gradually increased with time and hot weather simultaneously. The model showed weak performance as its predictions were underestimated for the validation period (2011-2015). Nevertheless, the results clearly revealed the efficiency of relative and multiple-variable approaches better than absolute and single-variable approaches. The results indicate the potential of the SSC as a suitable system for investigating heat vulnerability in South Korea, where hot summers could be a significant risk factor.

  18. Density functional theory metadynamics of silver, caesium and palladium diffusion at β-SiC grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Rabone, Jeremy, E-mail: jeremy.rabone@ec.europa.eu [European Commission, Joint Research Centre, Institute for Transuranium Elements, D-76125 Karlsruhe (Germany); López-Honorato, Eddie [Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV), Unidad Saltillo, Industria Metalúrgica 1062, Parque Industrial, Ramos Arizpe 25900, Coahuila (Mexico)

    2015-03-15

    Highlights: • DFT metadynamics of diffusion of Pd, Ag and Cs on grain boundaries in β-SiC. • The calculated diffusion rates for Pd and Ag tally with experimental release rates. • A mechanism of release other than grain boundary diffusion seems likely for Cs. - Abstract: The use of silicon carbide in coated nuclear fuel particles relies on this materials impermeability towards fission products under normal operating conditions. Determining the underlying factors that control the rate at which radionuclides such as Silver-110m and Caesium-137 can cross the silicon carbide barrier layers, and at which fission products such as palladium could compromise or otherwise alter the nature of this layer, are of paramount importance for the safety of this fuel. To this end, DFT-based metadynamics simulations are applied to the atomic diffusion of silver, caesium and palladium along a Σ5 grain boundary and to palladium along a carbon-rich Σ3 grain boundary in cubic silicon carbide at 1500 K. For silver, the calculated diffusion coefficients lie in a similar range (7.04 × 10{sup −19}–3.69 × 10{sup −17} m{sup 2} s{sup −1}) as determined experimentally. For caesium, the calculated diffusion rates are very much slower (3.91 × 10{sup −23}–2.15 × 10{sup −21} m{sup 2} s{sup −1}) than found experimentally, suggesting a different mechanism to the simulation. Conversely, the calculated atomic diffusion of palladium is very much faster (7.96 × 10{sup −11}–7.26 × 10{sup −9} m{sup 2} s{sup −1}) than the observed penetration rate of palladium nodules. This points to the slow dissolution and rapid regrowth of palladium nodules as a possible ingress mechanism in addition to the previously suggested migration of entire nodules along grain boundaries. The diffusion rate of palladium along the Σ3 grain boundary was calculated to be slightly slower (2.38 × 10{sup −11}–8.24 × 10{sup −10} m{sup 2} s{sup −1}) than along the Σ5 grain boundary. Rather

  19. Fabrication of Polybenzimidazole/Palladium Nanoparticles Hollow Fiber Membranes for Hydrogen Purification

    KAUST Repository

    Villalobos, Luis Francisco

    2017-09-13

    A novel scheme to fabricate polybenzimidazole (PBI) hollow fiber membranes with a thin skin loaded with fully dispersed palladium nanoparticles is proposed for the first time. Palladium is added to the membrane during the spinning process in the form of ions that coordinate to the imidazole groups of the polymer. This is attractive for membrane production because agglomeration of nanoparticles is minimized and the high-cost metal is incorporated in only the selective layer—where it is required. Pd-containing membranes achieve three orders of magnitude higher H2 permeances and a twofold improvement in H2/CO2 selectivity compared to pure PBI hollow fiber membranes.

  20. Watermelon rind-mediated green synthesis of noble palladium nanoparticles: catalytic application

    Science.gov (United States)

    Lakshmipathy, R.; Palakshi Reddy, B.; Sarada, N. C.; Chidambaram, K.; Khadeer Pasha, Sk.

    2015-02-01

    The present study reports the feasibility of synthesis of palladium nanoparticles (Pd NPs) by watermelon rind. The aqueous extract prepared from watermelon rind, an agro waste, was evaluated as capping and reducing agent for biosynthesis of palladium nanoparticles. The formation of Pd NPs was visually monitored with change in color from pale yellow to dark brown and later monitored with UV-Vis spectroscopy. The synthesized Pd NPs were further characterized by XRD, FTIR, DLS, AFM and TEM techniques. The synthesized Pd NPs were employed in Suzuki coupling reaction as catalyst. The results reveal that watermelon rind, an agro waste, is capable of synthesizing spherical-shaped Pd NPs with catalytic activity.

  1. Insertion of molecular oxygen into a palladium(II) methyl bond: a radical chain mechanism involving palladium(III) intermediates.

    Science.gov (United States)

    Boisvert, Luc; Denney, Melanie C; Hanson, Susan Kloek; Goldberg, Karen I

    2009-11-04

    The reaction of (bipy)PdMe(2) (1) (bipy = 2,2'-bipyridine) with molecular oxygen results in the formation of the palladium(II) methylperoxide complex (bipy)PdMe(OOMe) (2). The identity of the product 2 has been confirmed by independent synthesis. Results of kinetic studies of this unprecedented oxygen insertion reaction into a palladium alkyl bond support the involvement of a radical chain mechanism. Reproducible rates, attained in the presence of the radical initiator 2,2'-azobis(2-methylpropionitrile) (AIBN), reveal that the reaction is overall first-order (one-half-order in both [1] and [AIBN], and zero-order in [O(2)]). The unusual rate law (half-order in [1]) implies that the reaction proceeds by a mechanism that differs significantly from those for organic autoxidations and for the recently reported examples of insertion of O(2) into Pd(II) hydride bonds. The mechanism for the autoxidation of 1 is more closely related to that found for the autoxidation of main group and early transition metal alkyl complexes. Notably, the chain propagation is proposed to proceed via a stepwise associative homolytic substitution at the Pd center of 1 with formation of a pentacoordinate Pd(III) intermediate.

  2. Mechanical, electrical, and thermal expansion properties of carbon nanotube-based silver and silver-palladium alloy composites

    Science.gov (United States)

    Pal, Hemant; Sharma, Vimal

    2014-11-01

    The mechanical, electrical, and thermal expansion properties of carbon nanotube (CNT)-based silver and silver-palladium (10:1, w/w) alloy nanocomposites are reported. To tailor the properties of silver, CNTs were incorporated into a silver matrix by a modified molecular level-mixing process. CNTs interact weakly with silver because of their non-reactive nature and lack of mutual solubility. Therefore, palladium was utilized as an alloying element to improve interfacial adhesion. Comparative microstructural characterizations and property evaluations of the nanocomposites were performed. The structural characterizations revealed that decorated type-CNTs were dispersed, embedded, and anchored into the silver matrix. The experimental results indicated that the modification of the silver and silver-palladium nanocomposite with CNT resulted in increases in the hardness and Young's modulus along with concomitant decreases in the electrical conductivity and the coefficient of thermal expansion (CTE). The hardness and Young's modulus of the nanocomposites were increased by 30%-40% whereas the CTE was decreased to 50%-60% of the CTE of silver. The significantly improved CTE and the mechanical properties of the CNT-reinforced silver and silver-palladium nanocomposites are correlated with the intriguing properties of CNTs and with good interfacial adhesion between the CNTs and silver as a result of the fabrication process and the contact action of palladium as an alloying element.

  3. Observation of radio frequency emissions from electrochemical loading experiments

    International Nuclear Information System (INIS)

    Kidwell, D.A.; Grabowski, K.S.; Dominguez, D.D.; DeChiaro Jr, L.F.

    2015-01-01

    Palladium foil cathodes were electrochemically loaded with deuterium from alkaline solutions of heavy water in specially designed closed calorimeter cells. Here, one cell is described that showed low levels of constant heat (1-7 mW) and radio frequency (RF) emanations, but the RF was not correlated with the heat production. This cell is compared with Pd 90 Rh 10 alloy cathodes that showed excess energy bursts of 2.4-44.3 kJ. In these cells, RF coincident with the bursts was observed peaking at different frequencies from about 450 kHz and extending into the MHz range. Some of the excess energy production in LENR may be in the MHz RF range, which has no conventional explanation in electrochemistry. (author)

  4. Low Temperature Steam Methane Reforming Over Ni Based Catalytic Membrane Prepared by Electroless Palladium Plating.

    Science.gov (United States)

    Lee, Sang Moon; Hong, Sung Chang; Kim, Sung Su

    2018-09-01

    A Pd/Ni-YSZ porous membrane with different palladium loadings and hydrazine as a reducing reagent was prepared by electroless plating and evaluated for the steam methane reforming activity. The steam-reforming activity of a Ni-YSZ porous membrane was greatly increased by the deposition of 4 g/L palladium in the low-temperature range (600 °C). With an increasing amount of reducing reagent, the Pd clusters were well dispersed on the Ni-YSZ surface and were uniform in size (∼500 nm). The Pd/Ni-YSZ catalytic porous membrane prepared by 1 of Pd/hydrazine ratio possessed an abundant amount of metallic Pd. The optimal palladium loadings and Pd/hydrazine ratio increased the catalytic activity in both the steam-reforming reaction and the Pd dispersion.

  5. Hydrogen uptake causes molecular "avalanches" in palladium | Argonne

    Science.gov (United States)

    air cylinders for storing the gas. Palladium, a precious metal closely related to platinum, is that storage or purification, and this research gets us closer to making that a reality. In this study take up hydrogen from the environment. "The ultimate goal is hydrogen storage or purification, and

  6. Adhesion enhancement between electroless nickel and polyester fabric by a palladium-free process

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yinxiang, E-mail: yxlu@fudan.edu.cn [Department of Materials Science, Fudan University, 220 Handan Road, Shanghai 200433 (China); Xue Longlong; Li Feng [Department of Materials Science, Fudan University, 220 Handan Road, Shanghai 200433 (China)

    2011-01-15

    A new, efficient, palladium- and etchant-free process for the electroless nickel plating of poly(ethylene terephthalate) (PET) fabric has been developed. PET electroless plating can be prepared in three steps, namely: (i) the grafting of thiol group onto PET, (ii) the silver Ag{sup 0} seeding of the PET surface, and (iii) the nickel metallization using electroless plating bath. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, X-ray photoelectron spectroscopy (XPS), Raman spectrometer, X-ray diffraction (XRD), and thermogravimetric analysis (TG) were used to characterize the samples in the process, and the nickel loading was quantified by weighing. This process successfully compares with the traditional one based on KMnO{sub 4}/H{sub 2}SO{sub 4} etching and palladium-based seed layer. The nickel coating obtained in this palladium-free process can pass through ultrasonic washing challenge, and shows excellent adhesion with the PET substrate. However, the sample with Pd catalyst via traditional process was damaged during the testing experiment.

  7. Preparation of palladium nanoparticles on alumina surface by chemical co-precipitation method and catalytic applications

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Avvaru Praveen; Kumar, B. Prem; Kumar, A.B.V. Kiran; Huy, Bui The [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of); Lee, Yong-Ill, E-mail: yilee@changwon.ac.kr [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Facile synthesis of palladium nanoparticles on alumina surface. Black-Right-Pointing-Pointer The surface morphology and properties of the nanocrystalline powders were characterized. Black-Right-Pointing-Pointer The catalytic activities of palladium nanoparticles were investigated. - Abstract: The present work reports a chemical co-precipitation process to synthesize palladium (Pd) nanoparticles using alumina as a supporting material. The optimized temperature for the formation of nanocrystalline palladium was found to be 600 Degree-Sign C. The X-ray diffraction (XRD) and Raman spectroscopy were used to study the chemical nature of the Pd in alumina matrix. The surface morphology and properties of the nanocrystalline powders were examined using thermogravimetric analysis (TG-DTA), XRD, Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The calcinations in different atmospheres including in the inert medium forms the pure nano Pd{sup 0} while in the atmospheric air indicates the existence pure Pd{sup 0} along with PdO nanoparticles. The catalytic activities of the as-synthesized nanocrystalline Pd nanoparticles in the alumina matrix were investigated in Suzuki coupling, Hiyama cross-coupling, alkene and alkyne hydrogenation, and aerobic oxidation reactions.

  8. Method and means for heating buildings in a district heating system with waste heat from a thermal power plant

    International Nuclear Information System (INIS)

    Margen, P.H.E.

    1975-01-01

    The waste heat from a thermal power plant is transported through a municipal heating network to a plurality of buildings to be heated. The quantity of heat thus supplied to the buildings is higher than that required for the heating of the buildings. The excess heat is released from the buildings to the atmosphere in the form of hot air

  9. Influence of residual catalyst on the properties of conjugated polyphenylenevinylene materials: Palladium nanoparticles and poor electrical performance

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Nyberg, R.B.; Jørgensen, M.

    2004-01-01

    polymer material prepared by two different routes: the palladium route and the condensation route. The performance in a device application of the two polymer materials was, however, very different, and the palladium route was demonstrated to give poor films with low breakdown voltages and short circuits....

  10. Insights into functional-group-tolerant polymerization catalysis with phosphine-sulfonamide palladium (II) complexes

    KAUST Repository

    Jian, Zhongbao; Falivene, Laura; Wucher, Philipp; Roesle, Philipp; Caporaso, Lucia; Cavallo, Luigi; Gç ttker-Schnetmann, Inigo; Mecking, Stefan

    2014-01-01

    Two series of cationic palladium(II) methyl complexes {[(2-MeOC6H4)2PC6H4SO2NHC6H3(2,6-R1,R2)]PdMe}2[A]2 (X1+-A: R1=R2=H: H1+-A; R1=R2=CH(CH3)2: DIPP1+-A; R1=H, R2=CF3: CF31+-A; A=BF4 or SbF6) and neutral palladium(II) methyl complexes {[(2-MeOC6H4

  11. Site preference of rare earth doping in palladium-iron-arsenide superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Stuerzer, Christine; Schulz, Anne; Johrendt, Dirk [Department Chemie, Ludwig-Maximilians-Universitaet Muenchen (Germany)

    2014-12-15

    The solid solutions (Ca{sub 1-y}RE{sub y}Fe{sub 1-x}Pd{sub x}As){sub 10}Pd{sub z}As{sub 8} with RE = La, Ce, and Pr were synthesized by solid state methods and characterized by X-ray powder diffraction with subsequent Rietveld refinements [(CaFeAs){sub 10}Pt{sub 3}As{sub 8}-type structure (''1038 type''), P anti 1, Z = 1]. Substitution levels (Ca/RE, Fe/Pd, and Pd/□) obtained from Rietveld refinements coincide well with the nominal values according to EDS and the linear courses of the lattice parameters as expected from the ionic radii. The RE atoms favor the one out of five calcium sites, which is eightfold coordinated by arsenic. This leads to significant stabilization of the structure, and especially prevents palladium over-doping in the iron-arsenide layers as observed in the pristine compound (CaFe{sub 1-x}Pd{sub x}As){sub 10}Pd{sub z}As{sub 8}. While the stabilization energy is estimated to about 40 kJ.mol{sup -1} by electronic structure calculations, the reason for the diminished Fe/Pd substitution through RE doping is still not yet understood. We suggest that the electrons transferred from RE{sup 3+} to the (Fe{sub 1-x}Pd{sub x})As layer makes higher palladium concentrations unfavorable. Anyway the reduced palladium doping enables superconductivity with critical temperatures up to 20 K (onset) in the RE doped Pd1038 samples, which could not be obtained earlier due to palladium over-doping in the active iron-arsenide layers. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Effects of heat waves on daily excess mortality in 14 Korean cities during the past 20 years (1991-2010): an application of the spatial synoptic classification approach.

    Science.gov (United States)

    Lee, Dae-Geun; Kim, Kyu Rang; Kim, Jiyoung; Kim, Baek-Jo; Cho, Chun-Ho; Sheridan, Scott C; Kalkstein, Laurence S; Kim, Ho; Yi, Seung-Muk

    2018-04-01

    The aims of this study are to explore the "offensive" summer weather types classified under the spatial synoptic classification (SSC) system and to evaluate their impacts on excess mortality in 14 Korean cities. All-cause deaths per day for the entire population were examined over the summer months (May-September) of 1991-2010. Daily deaths were standardized to account for long-term trends of subcycles (annual, seasonal, and weekly) at the mid-latitudes. In addition, a mortality prediction model was constructed through multiple stepwise regression to develop a heat-health warning system based on synoptic climatology. The result showed that dry tropical (DT) days during early summer caused excess mortality due to non-acclimatization by inhabitants, and moist tropical (MT) plus and double plus resulted in greater spikes of excess mortality due to extremely hot and humid conditions. Among the 14 Korean cities, highly excess mortality for the elderly was observed in Incheon (23.2%, 95%CI 5.6), Seoul (15.8%, 95%CI 2.6), and Jeonju (15.8%, 95%CI 4.6). No time lag effect was observed, and excess mortality gradually increased with time and hot weather simultaneously. The model showed weak performance as its predictions were underestimated for the validation period (2011-2015). Nevertheless, the results clearly revealed the efficiency of relative and multiple-variable approaches better than absolute and single-variable approaches. The results indicate the potential of the SSC as a suitable system for investigating heat vulnerability in South Korea, where hot summers could be a significant risk factor.

  13. REMOVAL OF NICKEL(II) AND PALLADIUM(II) FROM SURFACE ...

    African Journals Online (AJOL)

    Preferred Customer

    Nickel is widely used in electroplating, in the manufacture of Ni-Cd batteries, in rods for arc welding, in pigments for ... Palladium has an extensive use in electrical industry as grids for ... It is also used as catalytic converter in motor vehicles.

  14. Palladium-based nanocatalysts for alcohol electrooxidation in alkaline media

    CSIR Research Space (South Africa)

    Modibedi, RM

    2013-01-01

    Full Text Available in the electrocatalytic oxidation of alcohols in alkaline media compared to platinum catalysts. Recent efforts have focused on the discovery of palladium-based electrocatalysts with little or no platinum for oxygen reduction reaction (ORR). This chapter is an overview...

  15. Microscopic observations of palladium used for cold fusion

    International Nuclear Information System (INIS)

    Matsumoto, T.

    1991-01-01

    This paper examines the microscopic structures of palladium metals used for cold fusion experiments. Tiny spot defects suggesting cold fusion have been observed in grain boundaries as the Nattoh model predicts. The relationship between these defects and a series of neutron busts and an indirect loop of hydrogen chain reactions are discussed

  16. Palladium-catalyzed aryl C-H olefination with unactivated, aliphatic alkenes.

    Science.gov (United States)

    Deb, Arghya; Bag, Sukdev; Kancherla, Rajesh; Maiti, Debabrata

    2014-10-01

    Palladium-catalyzed coupling between aryl halides and alkenes (Mizoroki-Heck reaction) is one of the most popular reactions for synthesizing complex organic molecules. The limited availability, problematic synthesis, and higher cost of aryl halide precursors (or their equivalents) have encouraged exploration of direct olefination of aryl carbon-hydrogen (C-H) bonds (Fujiwara-Moritani reaction). Despite significant progress, the restricted substrate scope, in particular noncompliance of unactivated aliphatic olefins, has discouraged the use of this greener alternative. Overcoming this serious limitation, we report here a palladium-catalyzed chelation-assisted ortho C-H bond olefination of phenylacetic acid derivatives with unactivated, aliphatic alkenes in good to excellent yields with high regio- and stereoselectivities. The versatility of this operationally simple method has been demonstrated through drug diversification and sequential C-H olefination for synthesizing divinylbenzene derivatives.

  17. Industrial Heat Pump for a High Temperature District Heating Application

    DEFF Research Database (Denmark)

    Poulsen, Claus Nørgaard

    by excess thermal energy from thermal solar panels. An industrial heat pump system using the natural refrigerant ammonia, is extracting the thermal energy from the storage when needed, and produce hot water at 85°C, for the district heating grid. The heat pump also acts as contributor to electricity grid...

  18. Palladium-catalysed direct cross-coupling of secondary alkyllithium reagents

    NARCIS (Netherlands)

    Vila, Carlos; Giannerini, Massimo; Hornillos, Valentin; Fananas-Mastral, Martin; Feringa, Ben L.

    2014-01-01

    Palladium-catalysed cross-coupling of secondary C(sp(3)) organometallic reagents has been a long-standing challenge in organic synthesis, due to the problems associated with undesired isomerisation or the formation of reduction products. Based on our recently developed catalytic C-C bond formation

  19. Halide-Enhanced Catalytic Activity of Palladium Nanoparticles Comes at the Expense of Catalyst Recovery

    Directory of Open Access Journals (Sweden)

    Azzedine Bouleghlimat

    2017-09-01

    Full Text Available In this communication, we present studies of the oxidative homocoupling of arylboronic acids catalyzed by immobilised palladium nanoparticles in aqueous solution. This reaction is of significant interest because it shares a key transmetallation step with the well-known Suzuki-Miyaura cross-coupling reaction. Additives can have significant effects on catalysis, both in terms of reaction mechanism and recovery of catalytic species, and our aim was to study the effect of added halides on catalytic efficiency and catalyst recovery. Using kinetic studies, we have shown that added halides (added as NaCl and NaBr can increase the catalytic activity of the palladium nanoparticles more than 10-fold, allowing reactions to be completed in less than half a day at 30 °C. However, this increased activity comes at the expense of catalyst recovery. The results are in agreement with a reaction mechanism in which, under conditions involving high concentrations of chloride or bromide, palladium leaching plays an important role. Considering the evidence for analogous reactions occurring on the surface of palladium nanoparticles under different reaction conditions, we conclude that additives can exert a significant effect on the mechanism of reactions catalyzed by nanoparticles, including switching from a surface reaction to a solution reaction. The possibility of this switch in mechanism may also be the cause for the disagreement on this topic in the literature.

  20. Palladium nanoparticles on InP for hydrogen detection

    Czech Academy of Sciences Publication Activity Database

    Černohorský, Ondřej; Žďánský, Karel; Zavadil, Jiří; Kacerovský, Pavel; Piksová, K.

    2011-01-01

    Roč. 6, č. 410 (2011), s. 4101-4104 ISSN 1931-7573 R&D Projects: GA AV ČR(CZ) KAN401220801; GA ČR GA102/09/1037 Institutional research plan: CEZ:AV0Z20670512 Keywords : palladium * indium phosphide Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 2.726, year: 2011

  1. Hydrogen sensor based on palladium-yttrium alloy nanosheet

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Boyi [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD 4111 (Australia); Zhu, Yong, E-mail: y.zhu@griffith.edu.au [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD 4111 (Australia); Chen, Youping; Song, Han; Huang, Pengcheng [School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074 (China); Dao, Dzung Viet [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD 4111 (Australia)

    2017-06-15

    This paper presents a hydrogen sensor based on palladium-yttrium (Pd-Y) alloy nanosheet. Zigzag-shaped Pd-Y nanosheet with a thickness of 19.3 nm was deposited on a quartz substrate by using an ultrahigh-vacuum magnetron sputtering system and shadow mask. The atomic ratio of palladium to yttrium in the nanosheet was 0.92/0.08. The fabrication process was simple and low-cost, and the sensor can be mass-produced. The experimental results show the sensor has a superior sensitivity, reversibility, and reproducibility. The resistive-based hydrogen detection mechanism in this research is much simpler and more compact compared to the optical-based detection method. - Highlights: • Pd-Y sensing element was fabricated using a magnetron sputtering system and shadow mask. • The Pd-Y compound consisted of 92% Pd and 8% Y. • The fabrication process was simple, low-cost, and mass-production compatible. • The sensor showed superior sensitivity, reversibility, and reproducibility to hydrogen gas. • The device is more compact than the optical-based counterpart.

  2. Hydrogen sensor based on palladium-yttrium alloy nanosheet

    International Nuclear Information System (INIS)

    Wang, Boyi; Zhu, Yong; Chen, Youping; Song, Han; Huang, Pengcheng; Dao, Dzung Viet

    2017-01-01

    This paper presents a hydrogen sensor based on palladium-yttrium (Pd-Y) alloy nanosheet. Zigzag-shaped Pd-Y nanosheet with a thickness of 19.3 nm was deposited on a quartz substrate by using an ultrahigh-vacuum magnetron sputtering system and shadow mask. The atomic ratio of palladium to yttrium in the nanosheet was 0.92/0.08. The fabrication process was simple and low-cost, and the sensor can be mass-produced. The experimental results show the sensor has a superior sensitivity, reversibility, and reproducibility. The resistive-based hydrogen detection mechanism in this research is much simpler and more compact compared to the optical-based detection method. - Highlights: • Pd-Y sensing element was fabricated using a magnetron sputtering system and shadow mask. • The Pd-Y compound consisted of 92% Pd and 8% Y. • The fabrication process was simple, low-cost, and mass-production compatible. • The sensor showed superior sensitivity, reversibility, and reproducibility to hydrogen gas. • The device is more compact than the optical-based counterpart.

  3. Hydrogen storage studies on palladium-doped carbon materials (AC, CB, CNMs) @ metal-organic framework-5.

    Science.gov (United States)

    Viditha, V; Srilatha, K; Himabindu, V

    2016-05-01

    Metal organic frameworks (MOFs) are a rapidly growing class of porous materials and are considered as best adsorbents for their high surface area and extraordinary porosity. The MOFs are synthesized by using various chemicals like triethylamine, terepthalic acid, zinc acetate dihydrate, chloroform, and dimethylformamide (DMF). Synthesized MOFs are intercalated with palladium/activated carbon, carbon black, and carbon nanomaterials by chemical reduction method for the purpose of enhancing the hydrogen adsorption capacities. We have observed that the palladium doped activated carbon on MOF-5 showed high hydrogen storage capacity. This may be due to the affinity of the palladium toward hydrogen molecule. The samples are characterized by X-ray diffraction, scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. We have observed a clear decrease in the BET surface area and pore volume. The obtained results show a better performance for the synthesized sample. To our best knowledge, no one has reported the work on palladium-doped carbon materials (activated carbon, carbon black, carbon nanomaterials) impregnated to the metal-organic framework-5. We have attempted to synthesize carbon nanomaterials using indigenously fabricated chemical vapor deposition (CVD) unit as a support. We have observed an increase in the hydrogen storage capacities.

  4. Enantioconvergent synthesis by sequential asymmetric Horner-Wadsworth-Emmons and palladium-catalyzed allylic substitution reactions

    DEFF Research Database (Denmark)

    Pedersen, Torben Møller; Hansen, E. Louise; Kane, John

    2001-01-01

    A new method for enantioconvergent synthesis has been developed. The strategy relies on the combination of an asymmetric Horner-Wadsworth-Emmons (HWE) reaction and a palladium-catalyzed allylic substitution. Different $alpha@-oxygen-substituted, racemic aldehydes were initially transformed by asy...... the allylic stereocenter and the alkene geometry. Thus, a single $gamma@-substituted ester was obtained as the overall product, in high isomeric purity. The method was applied to a synthesis of a subunit of the iejimalides, a group of cytotoxic macrolides.......A new method for enantioconvergent synthesis has been developed. The strategy relies on the combination of an asymmetric Horner-Wadsworth-Emmons (HWE) reaction and a palladium-catalyzed allylic substitution. Different $alpha@-oxygen-substituted, racemic aldehydes were initially transformed...... by asymmetric HWE reactions into mixtures of two major $alpha@,$beta@-unsaturated esters, possessing opposite configurations at their allylic stereocenters as well as opposite alkene geometry. Subsequently, these isomeric mixtures of alkenes could be subjected to palladium-catalyzed allylic substitution...

  5. Controlled deposition of palladium nanodendrites on the tips of gold nanorods and their enhanced catalytic activity.

    Science.gov (United States)

    Su, Gaoxing; Jiang, Huaqiao; Zhu, Hongyan; Lv, Jing-Jing; Yang, Guohai; Yan, Bing; Zhu, Jun-Jie

    2017-08-31

    Plasmonic Au-Pd nanostructures have drawn significant attention for use in heterogeneous catalysis. In this study, palladium nanodendrite-tipped gold nanorods (PdND-T-AuNRs) were subjected to a facile fabrication under mild reaction conditions. The palladium amounts on the two tips were tunable. In the preparation of PdND-T-AuNRs, dense capped AuNRs, a low reaction temperature, and suitable stabilizing agents were identified as critical reaction parameters for controlling palladium nanodendrites deposited on both ends of AuNRs. After overgrowth with palladium nanodendrites, the longitudinal surface plasmonic resonance peaks of PdND-T-AuNRs were red-shifted from 810 nm to 980 nm. The electrocatalytic activity of PdND-T-AuNRs for ethanol oxidation was examined, which was a bit weaker than that of cuboid core-shell Au-Pd nanodendrites; however, PdND-T-AuNRs were more stable in ethanol electrooxidation. Moreover, the photocatalytic activity of PdND-T-AuNRs for Suzuki cross-coupling reactions was investigated. At room temperature, nearly 100% yield was obtained under laser irradiation. The results can further enhance our capability of fine-tuning the optical, electronic, and catalytic properties of the bimetallic Au-Pd nanostructures.

  6. Chlorodifluoromethane-triggered formation of difluoromethylated arenes catalysed by palladium

    Science.gov (United States)

    Feng, Zhang; Min, Qiao-Qiao; Fu, Xia-Ping; An, Lun; Zhang, Xingang

    2017-09-01

    Difluoromethylated aromatic compounds are of increasing importance in pharmaceuticals, agrochemicals and materials. Chlorodifluoromethane (ClCF2H), an inexpensive, abundant and widely used industrial raw material, represents the ideal and most straightforward difluoromethylating reagent, but introduction of the difluoromethyl group (CF2H) from ClCF2H into aromatics has not been reported. Here, we describe a direct palladium-catalysed difluoromethylation method for coupling ClCF2H with arylboronic acids and esters to generate difluoromethylated arenes with high efficiency. The reaction exhibits a remarkably broad substrate scope, including heteroarylboronic acids, and was used for difluoromethylation of a range of pharmaceuticals and biologically active compounds. Preliminary mechanistic studies revealed that a palladium difluorocarbene intermediate is involved in the reaction. Although numerous metal-difluorocarbene complexes have been prepared, the catalytic synthesis of difluoromethylated or difluoromethylenated compounds involving metal-difluorocarbene complexes has not received much attention. This new reaction therefore also opens the door to understand metal-difluorocarbene complex catalysed reactions.

  7. A Palladium-Tin Modified Microband Electrode Array for Nitrate Determination

    Directory of Open Access Journals (Sweden)

    Yexiang Fu

    2015-09-01

    Full Text Available A microband electrode array modified with palladium-tin bimetallic composite has been developed for nitrate determination. The microband electrode array was fabricated by Micro Electro-Mechanical System (MEMS technique. Palladium and tin were electrodeposited successively on the electrode, forming a double-layer structure. The effect of the Pd-Sn composite was investigated and its enhancement of catalytic activity and lifetime was revealed. The Pd-Sn modified electrode showed good linearity (R2 = 0.998 from 1 mg/L to 20 mg/L for nitrate determination with a sensitivity of 398 μA/(mg∙L−1∙cm2. The electrode exhibited a satisfying analytical performance after 60 days of storage, indicating a long lifetime. Good repeatability was also displayed by the Pd-Sn modified electrodes. The results provided an option for nitrate determination in water.

  8. Palladium nanoparticles supported on layered hydroxide salts and their use in carbon-carbon coupling organic reactions

    OpenAIRE

    Martínez,Maby; Ocampo,Rogelio; Rios,Luz Amalia; Ramírez,Alfonso; Giraldo,Oscar

    2011-01-01

    Palladium nanoparticles supported on zinc hydroxide salts were prepared by intercalation of [PdCl6]2- and its further reduction with ethanol under reflux. All the materials were completely characterized by atomic absorption spectroscopy (AAS), X-ray diffraction (XRD), thermogravimetric/derivative thermogravimetric (TG/DTG) analyses, scanning electron microscopy (SEM), UV-Visible spectrometry and transmission electron microscopy (TEM). TEM analysis confirmed that the palladium nanoparticles we...

  9. Observation of Binuclear Palladium Clusters Upon ESI-MS Monitoring of the Suzuki-Miyaura Cross-Coupling Catalyzed by a Dichloro-bis(aminophosphine) Complex of Palladium

    Czech Academy of Sciences Publication Activity Database

    Agrawal, Divya; Schröder, Detlef; Frech, C. M.

    2011-01-01

    Roč. 30, č. 13 (2011), s. 3579-3587 ISSN 0276-7333 Institutional research plan: CEZ:AV0Z40550506 Keywords : catalysis * C-C coupling * electrospray ionization * palladium * Suzuki-Miyaura coupling Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.963, year: 2011

  10. The initiation of excess power and possible products of nuclear interactions during the electrolysis of heavy water

    International Nuclear Information System (INIS)

    Scott, C.D.; Mrochek, J.E.; Scott, T.C.; Michaels, G.E.; Newman, E.; Petek, M.

    1990-01-01

    The electrolysis of heavy water is being investigated with an insulated flow calorimetric system. The electrolyte was 0.1 to 1.0 N LiOD in D 2 O and cylindrical palladium cathodes surrounded by wire-wound platinum anodes have been used at cathode current densities of 100 to 800 mA/cm 2 . The most recent test has been made with a ''closed system'' without off-gal in which the electrolysis gases were internally recombined. Fast neutrons and gamma rays were measured continuously during the tests. It was shown that certain system perturbations could initiate and extend generation of excess power. In one test, there was an apparent increase in the neutron count rate that was also coincident with system perturbations. 4 refs., 6 figs

  11. Electrochemical catalytic activities of nanoporous palladium rods for methanol electro-oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaoguang; Wang, Weimin; Qi, Zhen; Zhao, Changchun; Ji, Hong; Zhang, Zhonghua [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (MOE), School of Materials Science and Engineering, Shandong University, Jingshi Road 73, Jinan 250061 (China)

    2010-10-01

    A novel electrocatalyst, nanoporous palladium (npPd) rods can be facilely fabricated by dealloying a binary Al{sub 80}Pd{sub 20} alloy in a 5 wt.% HCl aqueous solution under free corrosion conditions. The microstructure of these nanoporous palladium rods has been characterized using scanning electron microscopy and transmission electron microscopy. The results show that each Pd rod is several microns in length and several hundred nanometers in diameter. Moreover, all the rods exhibit a typical three-dimensional bicontinuous interpenetrating ligament-channel structure with length scale of 15-20 nm. The electrochemical experiments demonstrate that these peculiar nanoporous palladium rods (mixed with Vulcan XC-72 carbon powders to form a npPd/C catalyst) reveal a superior electrocatalytic performance toward methanol oxidation in the alkaline media. In addition, the electrocatalytic activity obviously depends on the metal loading on the electrode and will reach to the highest level (223.52 mA mg{sup -1}) when applying 0.4 mg cm{sup -2} metal loading on the electrode. Moreover, a competing adsorption mechanism should exist when performing methanol oxidation on the surface of npPd rods, and the electro-oxidation reaction is a diffusion-controlled electrochemical process. Due to the advantages of simplicity and high efficiency in the mass production, the npPd rods can act as a promising candidate for the anode catalyst for direct methanol fuel cells (DMFCs). (author)

  12. Electrochemical 'cold fusion' trials at IPP Garching

    International Nuclear Information System (INIS)

    Bosch, H.S.; Gernhardt, J.; Karger, F.; Perchermeier, J.; Wurden, G.A.

    1989-07-01

    Following the report of Fleischmann and Pons, we (The Bavarian Bubble Bottle Team) have attempted to reproduce their claims of cold nuclear fusion, and failed. We note that our measurements would not be able to detect neutrons at the level of Jones et al. Three electrolytic cell experiments were conducted using palladium cathodes and Platinum anodes, in a 0.1 Molar solution of LiD in heavy water, without any signs of neutrons, tritium or gammas above backgrounds, and within ±0.3 Watt accuracy calorimetry, no excess heating. Excess heating at the levels of F P would have been easily detected, if present. Intrinsic tritium, differing from each D 2 O bottle tested, was however observed. The longest duration experiment ran for 21 days, and was an attempt to duplicate the large 'melting incident' of F P . This was terminated on April 28, 1989, by throwing the vacuum-cast 22 gram, deuterium-loaded palladium cathode directly into liquid nitrogen, immediately next to a bare BF 3 counter (backed by 25 cm of moderator), in order to attempt one of the Italian ENEA neutron production variants. No neutrons above backgrounds were seen, while counting for one hour, and also none while the piece warmed to room temperature over the next hour. Post mortem analysis of the darkened, hardened Pd piece showed large crystal grains (up to 2 mmx2 mm), and continuing evolution of gas bubbles at the grain boundaries even four days after the experiment was ended. Eight weeks after loading, the catalytically active palladium piece continued to create heavy water (with exposure to oxygen in the air). (orig.)

  13. Ester versus polyketone formation in the palladium-diphosphine catalyzed carbonylation of ethene.

    Science.gov (United States)

    Zuidema, Erik; Bo, Carles; van Leeuwen, Piet W N M

    2007-04-04

    The origin of the chemoselectivity of palladium catalysts containing bidentate phosphine ligands toward either methoxycarbonylation of ethene or the copolymerization of ethene and carbon monoxide was investigated using density functional theory based calculations. For a palladium catalyst containing the electron-donating bis(dimethylphosphino)ethane (dmpe) ligand, the rate determining step for chain propagation is shown to be the insertion of ethene into the metal-acyl bond. The high barrier for chain propagation is attributed to the low stability of the ethene intermediate, (dmpe)Pd(ethene)(C(O)CH3). For the competing methanolysis process, the most likely pathway involves the formation of (dmpe)Pd(CH3OH)(C(O)CH3) via dissociative ligand exchange, followed by a solvent mediated proton-transfer/reductive- elimination process. The overall barrier for this process is higher than the barrier for ethene insertion into the palladium-acetyl bond, in line with the experimentally observed preference of this type of catalyst toward the formation of polyketone. Electronic bite angle effects on the rates of ethene insertion and ethanoyl methanolysis were evaluated using four electronically and sterically related ligands (Me)2P(CH2)nP(Me)2 (n = 1-4). Steric effects were studied for larger tert-butyl substituted ligands using a QM/MM methodology. The results show that ethene coordination to the metal center and subsequent insertion into the palladium-ethanoyl bond are disfavored by the addition of steric bulk around the metal center. Key intermediates in the methanolysis mechanism, on the other hand, are stabilized because of electronic effects caused by increasing the bite angle of the diphosphine ligand. The combined effects explain successfully which ligands give polymer and which ones give methyl propionate as the major products of the reaction.

  14. Nickel foam/polyaniline-based carbon/palladium composite electrodes for hydrogen storage

    International Nuclear Information System (INIS)

    Skowronski, Jan M.; Urbaniak, Jan

    2008-01-01

    The sandwich-like nickel/palladium/carbon electrodes exhibiting ability to absorb hydrogen in alkaline solution are presented. Electrodes were prepared by successive deposition of palladium and polyaniline layers on nickel foam substrate followed by heat treatment to give Ni/Pd/C electrode. It was shown that thermal conversion of polymer into carbon layer and subsequent thermal activation of carbon component bring about the modification of the mechanism of reversible hydrogen sorption. It was proven that carbon layer, interacting with Pd catalyst, plays a considerable role in the process of hydrogen storage. In the other series of experiments, Pd particles were dispersed electrochemically on carbon coating leading to Ni/C/Pd system. The adding of the next carbon layer resulted in Ni/C/Pd/C electrodes. Electrochemical properties of the electrodes depend on both the sequence of Pd and C layers and the preparation/activation of carbon coating. Electrochemical behavior of sandwich-like electrodes in the reaction of hydrogen sorption/desorption was characterized in 6 M KOH using the cyclic voltammetry method and the results obtained were compared to those for Ni/Pd electrode. The anodic desorption of hydrogen from electrodes free and containing carbon layer was considered after the potentiodynamic as well as potentiostatic sorption of hydrogen. The influence of the sorption potential and the time of rest of electrodes at a cut-off circuit on the kinetics of hydrogen recovery were examined. The results obtained for Ni/Pd/C electrodes indicate that the displacement of hydrogen between C and Pd phase takes place during the rest at a cut-off circuit. Electrodes containing carbon layer require longer time for hydrogen electrosorption. On the other hand, the presence of carbon layer in electrodes is advantageous because a considerable longer retention of hydrogen is possible, as compared to Pd/Ni electrode. Hydrogen stored in sandwich-like electrodes can instantly be

  15. Synthesis of pyrrolo(2,3-b)quinolines by palladium-catalyzed heteroannulation

    International Nuclear Information System (INIS)

    Gee, Moon Bae; Lee, Won Jung; Yum, Eul Kgun

    2003-01-01

    Palladium-catalyzed heteroannulation of 2-amino-3-iodoquinoline derivatives and 1-trimethylsilyl internal alkynes provided highly regioselective pyrrolo(2,3-b)quinolines with trimethylsilyl group next to the nitrogen atom in the pyrrole ring

  16. Palladium extraction by a malonamide: behavior and particularities compared to rare earths

    International Nuclear Information System (INIS)

    Poirot, Remi

    2014-01-01

    Recycling of valuable metals appears as a solution of growing interest for a sustainable supply strategy nowadays. Palladium (Pd), along with other platinum group metals (PGM) and rare earth elements (REEs), represents one of the crucial issues in recovery processes. Malonamides are neutral amphiphilic molecules which have proved their potency for the extraction of lanthanides. These extractants in nitric media were thoroughly studied in frame of nuclear fuel treatment towards lanthanide-actinide separation. Within this framework, our purpose was to study liquid/liquid (L/L) extraction towards Pd recovery from nitric media by a malonamide: the DMDOHEMA. Various parameters such as as equilibration time, pH, extractant and nitrate concentrations were investigated in detail. In some experimental conditions, a Pd-rich solid third phase appears at the interface. These third phases were deeply analyzed with NMR, IR and XPS. Mechanistic studies involved complete analysis of the organic phases, including chemical speciation at the molecular level (coordination chemistry with NMR, IR, XRD), and supramolecular ordering characterization (with SAXS and NMR). Palladium complexes were identified and characterized. Similarities and differences between palladium and lanthanides behavior during extraction were evidenced and both can be efficiently co-extracted or separated according to different experimental conditions. (author) [fr

  17. Correction of Excessive Precipitation Over Steep and High Mountains in a General Circulation Model

    Science.gov (United States)

    Chao, Winston C.

    2012-01-01

    Excessive precipitation over steep and high mountains (EPSM) is a well-known problem in GCMs and meso-scale models. This problem impairs simulation and data assimilation products. Among the possible causes investigated in this study, we found that the most important one, by far, is a missing upward transport of heat out of the boundary layer due to the vertical circulations forced by the daytime upslope winds, which are forced by the heated boundary layer on subgrid-scale slopes. These upslope winds are associated with large subgrid-scale topographic variation, which is found over steep and high mountains. Without such subgridscale heat ventilation, the resolvable-scale upslope flow in the boundary layer generated by surface sensible heat flux along the mountain slopes is excessive. Such an excessive resolvablescale upslope flow combined with the high moisture content in the boundary layer results in excessive moisture transport toward mountaintops, which in turn gives rise to EPSM. Other possible causes of EPSM that we have investigated include 1) a poorly-designed horizontal moisture flux in the terrain-following coordinates, 2) the condition for cumulus convection being too easily satisfied at mountaintops, 3) the presence of conditional instability of the computational kind, and 4) the absence of blocked flow drag. These are all minor or inconsequential. We have parameterized the ventilation effects of the subgrid-scale heated-slope-induced vertical circulation (SHVC) by removing heat from the boundary layer and depositing it in layers higher up when the topographic variance exceeds a critical value. Test results using NASA/Goddard's GEOS-S GCM have shown that this largely solved the EPSM problem.

  18. Studies on the preparation of 109Pd and 111Ag by (n,γ) reactions on natural palladium for possible applications in radionuclide therapy

    International Nuclear Information System (INIS)

    Vimalnath, K.V.; Chirayil, Viju; Saha, Sujata

    2007-01-01

    Natural palladium on neutron activation provided two radionuclides viz 111 Ag and 109 Pd with attractive nuclear properties for use in radionuclide therapy applications in nuclear medicine. 109 Pd (t 1/2 13.7h, E βmax 1.03MeV) was produced by neutron activation of 108 Pd, while in the same target 111 Ag (t 1/2 7.45d, E βmax 1.04MeV) is formed by the beta decay of co-produced radioactive 111 Pd. Measured samples of palladium foils were neutron irradiated in Dhruva reactor for 7d at a flux of 9 x 10 13 n.cm -2 .s -1 . Radioactive palladium and silver were separated by ion-exchange chromatography over Dowex 1x8, 200-400 mesh size anion exchanger column. Radiochemical mixture of palladium and silver loaded in 10M HCl acid medium showed retention of palladium, while silver eluted out freely. The separated radionuclidically pure fractions of 109 Pd and 111 Ag activity were reconstituted as chloride and nitrate solutions respectively. About 133 GBq 109 Pd and 930 MBq of 111 Ag activity were produced from 100mg palladium. (author)

  19. Prefunctionalized Porous Organic Polymers: Effective Supports of Surface Palladium Nanoparticles for the Enhancement of Catalytic Performances in Dehalogenation.

    Science.gov (United States)

    Zhong, Hong; Liu, Caiping; Zhou, Hanghui; Wang, Yangxin; Wang, Ruihu

    2016-08-22

    Three porous organic polymers (POPs) containing H, COOMe, and COO(-) groups at 2,6-bis(1,2,3-triazol-4-yl)pyridyl (BTP) units (i.e., POP-1, POP-2, and POP-3, respectively) were prepared for the immobilization of metal nanoparticles (NPs). The ultrafine palladium NPs are uniformly encapsulated in the interior pores of POP-1, whereas uniform- and dual-distributed palladium NPs are located on the external surface of POP-2 and POP-3, respectively. The presence of carboxylate groups not only endows POP-3 an outstanding dispersibility in H2 O/EtOH, but also enables the palladium NPs at the surface to show the highest catalytic activity, stability, and recyclability in dehalogenation reactions of chlorobenzene at 25 °C. The palladium NPs on the external surface are effectively stabilized by the functionalized POPs containing BTP units and carboxylate groups, which provides a new insight for highly efficient catalytic systems based on surface metal NPs of porous materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Investigation of short-lived neutron-rich palladium and silver isotopes after fast chemical separation from fission fragments

    International Nuclear Information System (INIS)

    Bruechle, W.

    1976-01-01

    In this paper, chemical separation processes are described permitting fast and neat isolation of short-lived palladium and silver nuclides from fusion product mixtures. The process for palladium is based on the stability of palladium diethyldithiophosphate. From fission products of the reactions 238 U(n,f) and 249 Cf(nth,f), the following palladium niclides could be studied for the first time by gamma spectroscopy: 1.66 min 113 Pd, 2.45 min 114 Pd, 29 sec sup(115a)Pd, 54 sec sup(115b)Pd, 12.5 sec 116 Pd. 113 Pd could also be indentified according to the reaction 116 Cd(n,α) 113 Pd. The separation of silver is based on the fast isotopic exchange on AgCl. With this process, the following nuclides have been separated from fission product mixtures and studied by gamma spectroscopy: 70 sec sup(113m)Ag, 5.0 sec 114 Ag, 19.2 sec sup(115m)Ag, 2.65 min sup(116g)Ag, 10.5 sec sup(116m)Ag, 1.3 min sup(117g)Ag, 6.0 sec sup(117m)Ag, 4.0 sec 118 Ag. (orig./WL) [de

  1. Palladium mixed-metal surface-modified AB5-type intermetallides enhance hydrogen sorption kinetics

    Directory of Open Access Journals (Sweden)

    Roman V. Denys

    2010-09-01

    Full Text Available Surface engineering approaches were adopted in the preparation of advanced hydrogen sorption materials, based on ‘low-temperature’, AB5-type intermetallides. The approaches investigated included micro-encapsulation with palladium and mixed-metal mantles using electroless plating. The influence of micro-encapsulation on the surface morphology and kinetics of hydrogen charging were investigated. It was found that palladium-nickel (Pd-Ni co-deposition by electroless plating significantly improved the kinetics of hydrogen charging of the AB5-type intermetallides at low hydrogen pressure and temperature, after long-term pre-exposure to air. The improvement in the kinetics of hydrogen charging was credited to a synergistic effect between the palladium and nickel atoms in the catalytic mantle and the formation of an ‘interfacial bridge’ for hydrogen diffusion by the nickel atoms in the deposited layer. The developed surface-modified materials may find application in highly selective hydrogen extraction, purification, and storage from impure hydrogen feeds.

  2. Heat stress management in hot mines

    CSIR Research Space (South Africa)

    Schutte, P

    2009-09-01

    Full Text Available consequences of excessive levels of occupational heat stress were recognized by the South African gold mining industry when the first death from heat stroke occurred in 1924 (1). Steps to combat the heat stress hazard were taken almost immediately... currently used in the South African mining industry. In South African mines, work environments having a wet-bulb temperature in excess of 27.4 °C are considered to be ‘hot’ and necessitate the introduction of practices to safeguard miners...

  3. Thermogravimetric determination of the enthalpy of astatine and radon adsorption on palladium surfaces

    International Nuclear Information System (INIS)

    Eichler, B.; Son Chun, K.

    1985-01-01

    In order to investigate the adsorption of astatine and radon on a palladium surface some on- and off-line thermochromatographic experiments were carried out with 210 At and 220 Rn tracers. The partial molar adsorption enthalpy for zero covering was found to be ΔH/sub a//sup 0, loc./(At) = -(15S +- 10) kJ mole -1 and ΔH/sub a//sup 0, mob./(Rn) = -(37 +- 4) kJ mole -1 . The results are compared with theoretical and experimental values for other elements of the sixth period. The adsorption behaviour of At is in conformity with that of the p-metals on a palladium surface. (author)

  4. Novel O N N Pyrazolyl-imine and Imidazolyl-imine Pincer Palladium ...

    African Journals Online (AJOL)

    NICO

    pincer palladium complexes in Heck coupling reactions. The general form of .... while single crystals suitable for X-ray analyses of complexes 1–4 were grown by ...... non-hydrogen atoms were refined with anisotropic displacement coefficients.

  5. Synthesis of honeycomb-like palladium nanostructures by using cucurbit[7]uril and their catalytic activities for reduction of 4-nitrophenol

    Energy Technology Data Exchange (ETDEWEB)

    Premkumar, Thathan [Department of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); The University College/Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Geckeler, Kurt E., E-mail: keg@gist.ac.kr [Department of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Department of Nanobio Materials and Electronics (WCU), Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2014-12-15

    An eco-friendly one-pot method to synthesize self-assembled palladium nanoclusters using a macrocycle, namely cucurbit[7]uril, in the alkaline medium without employing any special reducing or capping agents and/or external energy at room temperature is described. This greener approach, which utilizes water as a benign solvent and biocompatible cucurbit[7]uril as both reducing and protecting agents, can be applied to synthesize other noble metal nanoparticles such as gold, silver, and platinum. Owing to unique structural arrangement of cucurbit[7]uril, it was possible to prepare palladium nanoclusters of honeycomb-like structure irrespective of the reaction conditions. The honeycomb-like palladium nanoclusters were characterized using transmission electron microscopy (TEM), higher-resolution TEM (HR-TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), UV–vis, and FT-IR spectroscopy. Significantly, the synthesized palladium nanoclusters exhibited catalytic activity for the reduction reaction of 4-nitrophenol at room temperature. The approach launched here is easy, green, and user-friendly in contrast to the conventional techniques using polymers or surfactants and harsh reductants. - Highlights: • A simple and one-pot method to synthesis palladium nanostructures with honey-comb like structure. • The strategy established here does not require any harsh and toxic reducing agents. • It has a potential to be a general method for the synthesis of metal nanoparticles in water medium. • Palladium nanoclusters can be used as catalyst for the reduction reaction of 4-nitrophenol. • This system makes a novel platform for industrial and biomedical applications.

  6. Synthesis of phenanthridines via palladium-catalyzed picolinamide-directed sequential C–H functionalization

    Directory of Open Access Journals (Sweden)

    Ryan Pearson

    2013-05-01

    Full Text Available We report a new synthesis of phenanthridines based on palladium-catalyzed picolinamide-directed sequential C–H functionalization reactions starting from readily available benzylamine and aryl iodide precursors. Under the catalysis of Pd(OAc2, the ortho-C–H bond of benzylpicolinamides is first arylated with an aryl iodide. The resulting biaryl compound is then subjected to palladium-catalyzed picolinamide-directed intramolecular dehydrogenative C–H amination with PhI(OAc2 oxidant to form the corresponding cyclized dihydrophenanthridines. The benzylic position of these dihydrophenanthridines could be further oxidized with Cu(OAc2, removing the picolinamide group and providing phenathridine products. The cyclization and oxidation could be carried out in a single step and afford phenathridines in moderate to good yields.

  7. Confined palladium colloids in mesoporous frameworks for carbon nanotube growth

    NARCIS (Netherlands)

    Berenguer-Murcia, A.; Rebrov, E.V.; Cabaj, M.; Wheatley, A.E.H.; Johnson, B.F.G.; Robertson, J.; Schouten, J.C.

    2009-01-01

    Palladium colloidal nanoparticles with an average size of approximately 2.4 nm have been incorporated into mesoporous inorganic thin films following a multistep approach. This involves the deposition of mesoporous titania thin films with a thickness of 200 nm by spin-coating on titanium plates with

  8. Tapered Optical Fiber Functionalized with Palladium Nanoparticles by Drop Casting and Laser Radiation for H₂ and Volatile Organic Compounds Sensing Purposes.

    Science.gov (United States)

    González-Sierra, Nancy Elizabeth; Gómez-Pavón, Luz Del Carmen; Pérez-Sánchez, Gerardo Francisco; Luis-Ramos, Arnulfo; Zaca-Morán, Plácido; Muñoz-Pacheco, Jesús Manuel; Chávez-Ramírez, Francisco

    2017-09-06

    A comparative study on the sensing properties of a tapered optical fiber pristine and functionalized with the palladium nanoparticles to hydrogen and volatile organic compounds (VOCs), is presented. The sensor response and, response/recovery times were extracted from the measurements of the transient response of the device. The tapered optical fiber sensor was fabricated using a single-mode optical fiber by the flame-brushing technique. Functionalization of the optical fiber was performed using an aqueous solution of palladium chloride by drop-casting technique assisted for laser radiation. The detection principle of the sensor is based on the changes in the optical properties of palladium nanoparticles when exposed to reducing gases, which causes a variation in the absorption of evanescent waves. A continuous wave laser diode operating at 1550 nm is used for the sensor characterization. The sensor functionalized with palladium nanoparticles by this technique is viable for the sensing of hydrogen and VOCs, since it shows an enhancement in sensor response and response time compared to the sensor based on the pristine optical microfiber. The results show that the fabricated sensor is competitive with other fiber optic sensors functionalized with palladium nanoparticles to the hydrogen.

  9. Sonogashira Coupling Reaction with Palladium Powder and Potassium Fluoride in Methanol

    Institute of Scientific and Technical Information of China (English)

    王磊; 李品华

    2003-01-01

    A Sonogashira coupling reaction of aromatic halides with terminal alkynes in the presence of palladium powder,potassium fluoride,cuprous iodide and triphenylphosphine in methanol,giving the corresponding coupling products aryl alkynes in good to excellent yiekls,was investigated.

  10. A micromachined calorimetric gas sensor: an application of electrodeposited nanostructured palladium for the detection of combustible gases.

    Science.gov (United States)

    Bartlett, Philip N; Guerin, Samuel

    2003-01-01

    Palladium films with regular nanoarchitectures were electrochemically deposited from the hexagonal (H1) lyotropic liquid crystalline phase of the nonionic surfactant octaethyleneglycol monohexadecyl ether (C16EO8) onto micromachined silicon hotplate structures. The H1-e Pd films were shown to have high surface areas (approximately 28 m2 g(-1)) and to act as effective and stable catalysts for the detection of methane in air on heating to 500 degrees C. The response of the H1-e Pd-coated planar pellistors was found to be linearly proportional to the concentration of methane between 0 and 2.5% in air with a detection limit below 0.125%. Our results show that the electrochemical deposition of nanostructured metal films offers a promising approach to the fabrication of micromachined calorimetric gas sensors for combustible gases.

  11. ERRATUM Study of microstructure in vanadium–palladium alloys by ...

    Indian Academy of Sciences (India)

    WINTEC

    ERRATUM. Study of microstructure in vanadium–palladium alloys by X-ray diffraction technique. J Ghosh, S K Chattopadhyay, A K Meikap, S K Chatterjee and P Chatterjee 2007 Bull. Mater. Sci. 30 447–454. In page 448, under §2.1 Warren–Averbach method, after equation (1), the sentence starting with “Then the domain ...

  12. Interaction of CO with Palladium Supported on Oxidized Tungsten

    Czech Academy of Sciences Publication Activity Database

    Jirka, Ivan; Plšek, Jan; Šutara, F.; Matolín, V.; Cháb, Vladimír; Prince, K. C.

    2006-01-01

    Roč. 110, č. 47 (2006), s. 23837-23844 ISSN 1520-6106 R&D Projects: GA ČR GA202/05/0244; GA AV ČR IAA1010413 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z10100521 Keywords : palladium * WOx surfaces * TPD Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.115, year: 2006

  13. XPS study of palladium sensitized nano porous silicon thin film

    Indian Academy of Sciences (India)

    Keywords. Porous silicon; passivation; palladium; oxidation; XPS. Abstract. Nano porous silicon (PS) was formed on -type monocrystalline silicon of 2–5 cm resistivity and (100) orientation by electrochemical anodization method using HF and ethanol as the electrolytes. High density of surface states, arising due to its ...

  14. Electronic structure of palladium and its relation to uv spectroscopy

    DEFF Research Database (Denmark)

    Christensen, N.E.

    1976-01-01

    The electronic-energy-band structure of palladium has been calculated by means of the relativistic augmented-plane-wave method covering energies up to 30 eV above the Fermi level. The optical interband transitions producing structure in the dielectric function up to photon energies of 25 eV have ...

  15. Palladium-based on-wafer electroluminescence studies of GaN-based LED structures

    Energy Technology Data Exchange (ETDEWEB)

    Salcianu, C.O.; Thrush, E.J.; Humphreys, C.J. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Plumb, R.G. [Centre for Photonic Systems, Department of Engineering, University of Cambridge, Cambridge CB3 0FD (United Kingdom); Boyd, A.R.; Rockenfeller, O.; Schmitz, D.; Heuken, M. [AIXTRON AG, Kackertstr. 15-17, 52072 Aachen (Germany)

    2008-07-01

    Electroluminescence (EL) testing of Light Emitting Diode (LED) structures is usually done at the chip level. Assessing the optical and electrical properties of LED structures at the wafer scale prior to their processing would improve the cost effectiveness of producing LED-lamps. A non-destructive method for studying the luminescence properties of the structure at the wafer-scale is photoluminescence (PL). However, the relationship between the on-wafer PL data and the final device EL can be less than straightforward (Y. H Aliyu et al., Meas. Sci. Technol. 8, 437 (1997)) as the two techniques employ different carrier injection mechanisms. This paper provides an overview of some different techniques in which palladium is used as a contact in order to obtain on-wafer electroluminescence information which could be used to screen wafers prior to processing into final devices. Quick mapping of the electrical and optical characteristics was performed using either palladium needle electrodes directly, or using the latter in conjunction with evaporated palladium contacts to inject both electrons and holes into the active region via the p-type capping layer of the structure. For comparison, indium was also used to make contact to the n-layer so that electrons could be directly injected into that layer. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Spatial and temporal distribution of platinum, palladium and rhodium in Zagreb air.

    Science.gov (United States)

    Rinkovec, Jasmina; Pehnec, Gordana; Godec, Ranka; Davila, Silvije; Bešlić, Ivan

    2018-09-15

    Platinum (Pt), palladium (Pd) and rhodium (Rh) are most widely used in the production of automotive catalytic converters that serve to reduce toxic emissions from motor vehicles. The aim of this study was to quantitatively determine the levels of platinum, palladium and rhodium in the PM 10 and PM 2.5 fraction of airborne particle matter and find their spatial and temporal distribution at different polluted areas of the city of Zagreb, Croatia. The method used in this paper included weekly sampling of airborne particle matter on quartz filters, microwave digestion in acid under high pressure and temperature, and analysis by inductively coupled plasma mass spectrometry (ICP MS). The results have shown that the highest mean values at all three sampling stations (North, Center, South) were obtained for palladium (3.856 pg m -3 , 5.396 pg m -3 , 5.600 pg m -3 ) and the lowest for rhodium (0.444 pg m -3 , 0.643 pg m -3 , 0.750 pg m -3 ). The average mass concentrations of platinum group elements (PGE) in PM 10 increased for all three elements in the direction North Zagreb are the first results of their kind for this area and will provide insights into the contribution of catalytic converters to the presence of these elements in the environment. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Nonenzymatic glucose sensing based on deposited palladium nanoparticles on epoxy-silver electrodes

    International Nuclear Information System (INIS)

    Gutes, Albert; Carraro, Carlo; Maboudian, Roya

    2011-01-01

    Highlights: → New nonenzymatic glucose sensor material. → Modified epoxy-silver electrodes with palladium nanoparticles. → Simple electroless surface modification. → Wide linear response range. → Easy implementation. - Abstract: A new approach for nonenzymatic glucose sensing, based on a simple modification of epoxy-silver surfaces deposited on the tip of commercial copper electric wires, is presented. Palladium was galvanically displaced on the surface of the epoxy-silver surface in order to obtain metal nanoparticles that act as catalyst for the direct oxidation of glucose. Scanning electron microscopy revealed the formation of the metal nanoparticles. X-ray photoelectron spectroscopy confirmed the metallic nature of the formed nanostructures on the surface. Electrochemical characterization and calibration of the palladium-modified epoxy-silver electrode is reported, obtaining a linear range of 1-20 mM for the detection of glucose with low interference of ascorbic acid and uric acid. A simple 3-step coulometry was used as the detection technique. The developed sensing material is believed to be a great candidate for integration in small devices for clinical essays, due to the simplicity and cost effectiveness of the presented approach, compared to the state-of-the-art devices reported recently in the literature. Simplicity in the coulometry determinations makes these Pd-modified epoxy-silver sensors a good candidate for easy glucose determinations.

  18. Biosorption of platinum and palladium for their separation/preconcentration prior to graphite furnace atomic absorption spectrometric determination

    Energy Technology Data Exchange (ETDEWEB)

    Godlewska-Zylkiewicz, Beata E-mail: bgodlew@uwb.edu.pl

    2003-08-15

    Inexpensive baker's yeast Saccharomyces cerevisiae and green algae Chlorella vulgaris, either free or immobilized on silica gel have been shown to selectively accumulate platinum and palladium from water samples in acidic medium (pH 1.6-1.8). Optimization of conditions of metals biosorption (sample pH, algae and yeast masses, adsorption time, temperature) was performed in batch mode. The procedure of matrix separation based on biosorption of platinum and palladium on algae C. vulgaris covalently immobilized on silica gel in flow mode was developed. The use of algae in flow procedure offers several advantages compared with its use in the batch mode. The procedure shows better reproducibility (<2%), improved efficiency of platinum retention on the column (93.3{+-}1.6%), is less laborious and less time consuming. The best recovery of biosorbed metals from column (87.7{+-}3.3% for platinum and 96.8{+-}1.1 for palladium) was obtained with solution of 0.3 mol l{sup -1} thiourea in 1 mol l{sup -1} hydrochloric acid. The influence of thiourea on analytical signals of examined metals during GFAAS determination is discussed. The procedure has been applied for separation of noble metals from tap and waste water samples spiked with platinum and palladium.

  19. Catalytic Palladium Film Deposited by Scalable Low-Temperature Aqueous Combustion.

    Science.gov (United States)

    Voskanyan, Albert A; Li, Chi-Ying Vanessa; Chan, Kwong-Yu

    2017-09-27

    This article describes a novel method for depositing a dense, high quality palladium thin film via a one-step aqueous combustion process which can be easily scaled up. Film deposition of Pd from aqueous solutions by conventional chemical or electrochemical methods is inhibited by hydrogen embrittlement, thus resulting in a brittle palladium film. The method outlined in this work allows a direct aqueous solution deposition of a mirror-bright, durable Pd film on substrates including glass and glassy carbon. This simple procedure has many advantages including a very high deposition rate (>10 cm 2 min -1 ) and a relatively low deposition temperature (250 °C), which makes it suitable for large-scale industrial applications. Although preparation of various high-quality oxide films has been successfully accomplished via solution combustion synthesis (SCS) before, this article presents the first report on direct SCS production of a metallic film. The mechanism of Pd film formation is discussed with the identification of a complex formed between palladium nitrate and glycine at low temperature. The catalytic properties and stability of films are successfully tested in alcohol electrooxidation and electrochemical oxygen reduction reaction. It was observed that combustion deposited Pd film on a glassy carbon electrode showed excellent catalytic activity in ethanol oxidation without using any binder or additive. We also report for the first time the concept of a reusable "catalytic flask" as illustrated by the Suzuki-Miyaura cross-coupling reaction. The Pd film uniformly covers the inner walls of the flask and eliminates the catalyst separation step. We believe the innovative concept of a reusable catalytic flask is very promising and has the required features to become a commercial product in the future.

  20. Studies on nickel (II and palladium (II complexes with some tetraazamacrocycles containing tellurium

    Directory of Open Access Journals (Sweden)

    Rathee Nitu

    2012-01-01

    Full Text Available The synthesis of 10-membered and 12-membered tellurium containing tetraazamacrocyclic complexes of divalent nickel and palladium by template condensation of diaryltellurium dichlorides, (aryl = p-hydroxyphenyl, 3-methyl-4-hydroxyphenyl, p-methoxyphenyl with 1,2-diaminoethane and 1,3-diaminopropane in the presence of metal dichloride is reported. The resulting complexes have been subjected to elemental analyses, magnetic measurements, electronic absorption, infra-red, and proton magnetic resonance spectral studies. The formation of proposed macrocyclic skeletons and their donor sites have been identified on the basis of spectral studies. Distorted octahedral structure for the nickel complexes in the solid state and squareplanar structure for the palladium complexes have been suggested.

  1. Low-temperature solution processing of palladium/palladium oxide films and their pH sensing performance.

    Science.gov (United States)

    Qin, Yiheng; Alam, Arif U; Pan, Si; Howlader, Matiar M R; Ghosh, Raja; Selvaganapathy, P Ravi; Wu, Yiliang; Deen, M Jamal

    2016-01-01

    Highly sensitive, easy-to-fabricate, and low-cost pH sensors with small dimensions are required to monitor human bodily fluids, drinking water quality and chemical/biological processes. In this study, a low-temperature, solution-based process is developed to prepare palladium/palladium oxide (Pd/PdO) thin films for pH sensing. A precursor solution for Pd is spin coated onto pre-cleaned glass substrates and annealed at low temperature to generate Pd and PdO. The percentages of PdO at the surface and in the bulk of the electrodes are correlated to their sensing performance, which was studied by using the X-ray photoelectron spectroscope. Large amounts of PdO introduced by prolonged annealing improve the electrode's sensitivity and long-term stability. Atomic force microscopy study showed that the low-temperature annealing results in a smooth electrode surface, which contributes to a fast response. Nano-voids at the electrode surfaces were observed by scanning electron microscope, indicating a reason for the long-term degradation of the pH sensitivity. Using the optimized annealing parameters of 200°C for 48 h, a linear pH response with sensitivity of 64.71±0.56 mV/pH is obtained for pH between 2 and 12. These electrodes show a response time shorter than 18 s, hysteresis less than 8 mV and stability over 60 days. High reproducibility in the sensing performance is achieved. This low-temperature solution-processed sensing electrode shows the potential for the development of pH sensing systems on flexible substrates over a large area at low cost without using vacuum equipment. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Selective extraction of palladium with caffeine from acidic chloride media; Sansei enkabutsu yoeki karano kafuein ni yoru parajiumu no sentakuteki chushutsu

    Energy Technology Data Exchange (ETDEWEB)

    Kaikake, K.; Baba, Y. [Miyazaki University, Miyazaki (Japan). Faculty of Engineering

    1999-06-10

    In order to examine the possibility of caffeine as an extractant, the extraction of metal ions from acidic chloride media was studied at 298 K using the mixture solvent of chloroform and 2-ethyl-1-hexanol. Caffeine has exhibited a high selectivity for palladium (2) over base metals such as copper (2), nickel (2), and iron (3), and over precious metal such as platinum (4). The stoichiometric relation in the extraction of palladium (2) with caffeine was elucidated by examining the effects of chloride ion, hydrogen ion, and caffeine concentrations on its extractability. In addition, palladium (2) was found to be extracted selectively with caffeine from the mixture containing a 25-fold amount of platinum (4) or copper (2). The stripping of palladium (2) was performed to an extent of 80% by a single batchwise treatment with an aqueous mixture solution of hydrochloric acid and thiourea. (author)

  3. Oxygen kinetics and mechanism at electrocatalysts on the base of palladium-iron system

    International Nuclear Information System (INIS)

    Tarasevich, M.R.; Zhutaeva, G.V.; Bogdanovskaya, V.A.; Radina, M.V.; Ehrenburg, M.R.; Chalykh, A.E.

    2007-01-01

    Binary nanodispersed carbon XC72 supported PdFe catalysts with different atomic palladium-to-iron ratios are synthesized and studied in oxygen reduction reaction in acid solution at 60 o C. The Pd:Fe ratio was well controlled by the initial concentrations of Pd and Fe in the precursor solutions. The nanoparticles were characterized by transmission electron microscopy, X-ray diffractometry and X-ray photoelectron spectroscopy. The optimum Pd:Fe ratio for this reaction was determined to be 3:1. The comparison of activities of the catalysts with component ratios equaled 3:1 and 10:1 is shown that the activities are differed from each other by 10-15 times in advantage of catalyst with lesser content of palladium. This phenomenon can be related to the different particle size of both catalysts and different distribution of particles by size discovered by TEM method. The achievement of maximum activity near the ratio of Pd:Fe = 3:1 is due to as effect of alloy-forming and the influence of binary system component ratio and synthesis conditions on dispersity degree of metallic phase nanoparticles. Under optimal conditions of precursor mixture high-temperature pyrolysis, iron produces the stabilizing effect palladium. It gives rise to obtaining the uniform and finely divided (7-8 nm) metallic particles

  4. Chalcogen-containing oxazolines in the palladium-catalyzed asymmetric allylic alkylation

    Directory of Open Access Journals (Sweden)

    Braga Antonio L.

    2006-01-01

    Full Text Available A comparative study about the ability of chiral chalcogen-containing oxazolines to act as chiral ligands in the palladium-catalyzed allylic alkylation of rac-1,3-diphenyl-2-propenyl acetate with dimethyl malonate is reported. Differences in the catalytic performance are observed with sulfur, selenium and tellurium analogues.

  5. Supporting Information Palladium Complexes of a New Type of N ...

    Indian Academy of Sciences (India)

    Prasenjit Ghosh

    Palladium Complexes of a New Type of N-heterocyclic Carbene. Ligand Derived From a Tricyclic Triazolooxazine Framework. Manoj Kumar Gangwar, Alok Ch. Kalita and Prasenjit Ghosh*. Department of Chemistry,. Indian Institute of Technology Bombay, ... 2. Figure S1. 1. H NMR spectrum of the compound 1a in CDCl3.

  6. Size control and supporting of palladium nanoparticles made by laser ablation in saline solution as a facile route to heterogeneous catalysts

    International Nuclear Information System (INIS)

    Marzun, Galina; Nakamura, Junji; Zhang, Xiaorui; Barcikowski, Stephan; Wagener, Philipp

    2015-01-01

    Graphical abstract: - Highlights: • We studied laser-generated, size-controlled palladium nanoparticles in saline solution. • Palladium nanoparticles were electrostatically stabilized by anions. • Photo- and electrocatalyst are prepared by supporting Pd nanoparticles to TiO 2 and graphene. • Particle size does not change during supporting process, while 18 wt% load has been achieved. • Palladium nanoparticles and graphene undergo a redox-reaction during adsorption. - Abstract: In the literature many investigations on colloidal stability and size control of gold nanoparticles are shown but less for ligand-free palladium nanoparticles, which can be promising materials in various applications. Palladium nanoparticles are perspective materials for a manifold of energy application like photo- and electrocatalysis or hydrogen storage. For this purpose, size-controlled nanoparticles with clean surfaces and facile immobilization on catalyst supports are wanted. Laser ablation in saline solution yields ligand-free, charged colloidal palladium nanoparticles that are supported by titania and graphene nanosheets as model systems for photo- and electrocatalysis, respectively. By adjusting the ionic strength during laser ablation in liquid, it is possible to control stability and particle size without compromising subsequent nanoparticle adsorption of supporting materials. A quantitative deposition of nearly 100% yield with up to 18 wt% nanoparticle load was achieved. The average size of the laser-generated nanoparticles remains the same after immobilization on a support material, in contrast to other preparation methods of catalysts. The characterization by X-ray photoelectron spectroscopy reveals a redox reaction between the immobilized nanoparticles and the graphene support

  7. Synthesis of heterocyclic compounds through palladium-catalyzed C-H cyclization processes.

    Science.gov (United States)

    Inamoto, Kiyofumi

    2013-01-01

    Herein, we describe our development of synthetic methods for heterocyclic compounds based on the palladium-catalyzed carbon-hydrogen bond (C-H) functionalization/intramolecular carbon-heteroatom (nitrogen or sulfur) bond formation process. By this C-H cyclization method, we efficiently prepared various N-heterocycles, including indazoles, indoles, and 2-quinolinones, as well as S-heterocycles such as benzothiazoles and benzo[b]thiophenes. Yields are typically good to high and good functional-group tolerance is observed for each process, thereby indicating that the method provides a novel, highly applicable synthetic route to the abovementioned biologically important heterocyclic frameworks. As an application of this approach, an auto-tandem-type, one-pot process involving the oxidative Heck reaction and subsequent C-H cyclization using cinnamamides and arylboronic acids as starting materials in the presence of a palladium catalyst was also developed for the rapid construction of the 2-quinolinone nucleus.

  8. The Melting Point of Palladium Using Miniature Fixed Points of Different Ceramic Materials: Part II—Analysis of Melting Curves and Long-Term Investigation

    Science.gov (United States)

    Edler, F.; Huang, K.

    2016-12-01

    Fifteen miniature fixed-point cells made of three different ceramic crucible materials (Al2O3, ZrO2, and Al2O3(86 %)+ZrO2(14 %)) were filled with pure palladium and used to calibrate type B thermocouples (Pt30 %Rh/Pt6 %Rh). A critical point by using miniature fixed points with small amounts of fixed-point material is the analysis of the melting curves, which are characterized by significant slopes during the melting process compared to flat melting plateaus obtainable using conventional fixed-point cells. The method of the extrapolated starting point temperature using straight line approximation of the melting plateau was applied to analyze the melting curves. This method allowed an unambiguous determination of an electromotive force (emf) assignable as melting temperature. The strict consideration of two constraints resulted in a unique, repeatable and objective method to determine the emf at the melting temperature within an uncertainty of about 0.1 μ V. The lifetime and long-term stability of the miniature fixed points was investigated by performing more than 100 melt/freeze cycles for each crucible of the different ceramic materials. No failure of the crucibles occurred indicating an excellent mechanical stability of the investigated miniature cells. The consequent limitation of heating rates to values below {± }3.5 K min^{-1} above 1100° C and the carefully and completely filled crucibles (the liquid palladium occupies the whole volume of the crucible) are the reasons for successfully preventing the crucibles from breaking. The thermal stability of the melting temperature of palladium was excellent when using the crucibles made of Al2O3(86 %)+ZrO2(14 %) and ZrO2. Emf drifts over the total duration of the long-term investigation were below a temperature equivalent of about 0.1 K-0.2 K.

  9. Palladium-Catalyzed alpha-Arylation of Tetramic Acids

    DEFF Research Database (Denmark)

    Storgaard, Morten; Dorwald, F. Z.; Peschke, B.

    2009-01-01

    A mild, racemization-free, palladium-Catalyzed alpha-arylation of tetramic acids (2,4-pyrrolidinediones) has been developed. Various amino acid-derived tetramic acids were cleanly arylated by treatment with 2 mol % of Pd(OAc)(2), 4 mol % of a sterically demanding biaryl phosphine, 2.3 equiv of K2CO...... no effect on their reactivity: both electron-rich and electron-poor aryl chlorides and bromides or triflates led to good yields. Ortho-substituted aryl halides and heteroaryl halides, however, did not undergo the title reaction....

  10. Synthesis of Dihydrobenzofurans via Palladium-Catalyzed Heteroannulations

    Energy Technology Data Exchange (ETDEWEB)

    Rozhkov, Roman Vladimirovich [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    Palladium-catalyzed heteroannulation of 1,3-dienes with 3-iodo-2-alkenols, and 2-iodo-2-alkenols, as well as their amino analogs, affords the corresponding cyclic ethers and amines respectively. The presence of a β-hydrogen in the vinylic halide results in β-hydride elimination giving the corresponding alkyne. The presence of a bulky group in the α-position of the vinylic halide results in failure or reduced amounts of annulation products. A chloride source, pyridine base and electron-rich phosphine are essential for this reaction.

  11. A tandem Mannich addition–palladium catalyzed ring-closing route toward 4-substituted-3(2H-furanones

    Directory of Open Access Journals (Sweden)

    Jubi John

    2014-06-01

    Full Text Available A facile route towards highly functionalized 3(2H-furanones via a sequential Mannich addition–palladium catalyzed ring closing has been elaborated. The reaction of 4-chloroacetoacetate esters with imines derived from aliphatic and aromatic aldehydes under palladium catalysis afforded 4-substituted furanones in good to excellent yields. 4-Hydrazino-3(2H-furanones could also be synthesized from diazo esters in excellent yields by utilising the developed strategy. We could also efficiently transform the substituted furanones to aza-prostaglandin analogues.

  12. Micromachined Dense Palladium Electrodes for Thin-film Solid Acid Fuel Cells

    NARCIS (Netherlands)

    Unnikrishnan, S.

    2009-01-01

    This thesis paves the way towards the microfabrication of a solid acid electrolyte based fuel cell (µSAFC), which has a membrane electrode assembly (MEA) consisting of a thin-film of water soluble electrolyte encapsulated between two dense palladium electrode membranes. This project work

  13. Experimental heat capacities, excess entropies, and magnetic properties of bulk and nano Fe3O4-Co3O4 and Fe3O4-Mn3O4 spinel solid solutions

    Science.gov (United States)

    Schliesser, Jacob M.; Huang, Baiyu; Sahu, Sulata K.; Asplund, Megan; Navrotsky, Alexandra; Woodfield, Brian F.

    2018-03-01

    We have measured the heat capacities of several well-characterized bulk and nanophase Fe3O4-Co3O4 and Fe3O4-Mn3O4 spinel solid solution samples from which magnetic properties of transitions and third-law entropies have been determined. The magnetic transitions show several features common to effects of particle and magnetic domain sizes. From the standard molar entropies, excess entropies of mixing have been generated for these solid solutions and compared with configurational entropies determined previously by assuming appropriate cation and valence distributions. The vibrational and magnetic excess entropies for bulk materials are comparable in magnitude to the respective configurational entropies indicating that excess entropies of mixing must be included when analyzing entropies of mixing. The excess entropies for nanophase materials are even larger than the configurational entropies. Changes in valence, cation distribution, bonding and microstructure between the mixing ions are the likely sources of the positive excess entropies of mixing.

  14. The effect of price regulation on the performances of industrial symbiosis: a case study on district heating

    DEFF Research Database (Denmark)

    Sacchi, Romain; Ramsheva, Yana Konstantinova

    2018-01-01

    . The most ambitious scenario doubles the amount of excess heat supplied and reduces the heat carbon footprint by 90% compared to current level, for an end-user price increase of 41%. The price increase results from a higher supply of excess heat at a higher price and an unchanged purchase cost from the coal......This study of the district heating system of Aalborg (Denmark) analyses how fiscal instruments affect the extent excess heat recovery helps reduce the carbon footprint of heat. It builds on a supply-and-demand framework and characterizes the changes in excess heat supply with consequential life...... cycle assessment in reference to one gigajoule distributed. The heat supply curve is defined through ten scenarios, which represent incremental shares of excess heat as the constraints of the said legal instruments are lifted. The heat demand curve follows the end-users’response to price changes...

  15. Solar Powered Heat Control System for Cars

    OpenAIRE

    Abin John; Jithin Thomas

    2014-01-01

    It takes times for an air-conditioner to effectively start cooling the passenger compartment in the car. So the passenger of the car will feel the heat in the car extremely before the air-conditioner fully cooling the interior of the car. Excessive heat can also damage an automobile's interior as well as personal property kept in the passenger compartment. So, a system to reduce this excessive heat by pumping out hot air and allowing cooler ambient air to enter the car by mean...

  16. SU-F-207-05: Excess Heat Corrections in a Prototype Calorimeter for Direct Realization of CT Absorbed Dose to Phantom

    International Nuclear Information System (INIS)

    Chen-Mayer, H; Tosh, R

    2015-01-01

    Purpose: To reconcile air kerma and calorimetry measurements in a prototype calorimeter for obtaining absorbed dose in diagnostic CT beams. While corrections for thermal artifacts are routine and generally small in calorimetry of radiotherapy beams, large differences in relative stopping powers of calorimeter materials at the lower energies typical of CT beams greatly magnify their effects. Work-to-date on the problem attempts to reconcile laboratory measurements with modeling output from Monte Carlo and finite-element analysis of heat transfer. Methods: Small thermistor beads were embedded in a polystyrene (PS) core element of 1 cm diameter, which was inserted into a cylindrical HDPE phantom of 30 cm diameter and subjected to radiation in a diagnostic CT x-ray imaging system. Resistance changes in the thermistors due to radiation heating were monitored via lock-in amplifier. Multiple 3-second exposures were recorded at 8 different dose-rates from the CT system, and least-squares fits to experimental data were compared to an expected thermal response obtained by finite-element analysis incorporating source terms based on semi-empirical modeling and Monte Carlo simulation. Results: Experimental waveforms exhibited large thermal artifacts with fast time constants, associated with excess heat in wires and glass, and smaller steps attributable to radiation heating of the core material. Preliminary finite-element analysis follows the transient component of the signal qualitatively, but predicts a slower decay of temperature spikes. This was supplemented by non-linear least-squares fits incorporating semi-empirical formulae for heat transfer, which were used to obtain dose-to-PS in reasonable agreement with the output of Monte Carlo calculations that converts air kerma to absorbed dose. Conclusion: Discrepancies between the finite-element analysis and our experimental data testify to the very significant heat transfer correction required for absorbed dose calorimetry of

  17. SU-F-207-05: Excess Heat Corrections in a Prototype Calorimeter for Direct Realization of CT Absorbed Dose to Phantom

    Energy Technology Data Exchange (ETDEWEB)

    Chen-Mayer, H; Tosh, R [NIST, Gaithersburg, MD (United States)

    2015-06-15

    Purpose: To reconcile air kerma and calorimetry measurements in a prototype calorimeter for obtaining absorbed dose in diagnostic CT beams. While corrections for thermal artifacts are routine and generally small in calorimetry of radiotherapy beams, large differences in relative stopping powers of calorimeter materials at the lower energies typical of CT beams greatly magnify their effects. Work-to-date on the problem attempts to reconcile laboratory measurements with modeling output from Monte Carlo and finite-element analysis of heat transfer. Methods: Small thermistor beads were embedded in a polystyrene (PS) core element of 1 cm diameter, which was inserted into a cylindrical HDPE phantom of 30 cm diameter and subjected to radiation in a diagnostic CT x-ray imaging system. Resistance changes in the thermistors due to radiation heating were monitored via lock-in amplifier. Multiple 3-second exposures were recorded at 8 different dose-rates from the CT system, and least-squares fits to experimental data were compared to an expected thermal response obtained by finite-element analysis incorporating source terms based on semi-empirical modeling and Monte Carlo simulation. Results: Experimental waveforms exhibited large thermal artifacts with fast time constants, associated with excess heat in wires and glass, and smaller steps attributable to radiation heating of the core material. Preliminary finite-element analysis follows the transient component of the signal qualitatively, but predicts a slower decay of temperature spikes. This was supplemented by non-linear least-squares fits incorporating semi-empirical formulae for heat transfer, which were used to obtain dose-to-PS in reasonable agreement with the output of Monte Carlo calculations that converts air kerma to absorbed dose. Conclusion: Discrepancies between the finite-element analysis and our experimental data testify to the very significant heat transfer correction required for absorbed dose calorimetry of

  18. Catalytic Enantioselective Alkylation of β-Keto Esters with Xanthydrol in the Presence of Chiral Palladium Complex

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyu Yeon; Kim, Dae Young [Soonchunhyang Univ., Asan (Korea, Republic of)

    2016-01-15

    Our research interest has been directed toward the development of synthetic methods for the enantioselective construction of stereogenic carbon centers. Recently, we explored the catalytic enantioselective functionalization of active methines in the presence of chiral palladium(II) complexes. In conclusion, we have accomplished the efficient catalytic enantioselective alkylation of β-keto esters 1 with xanthydrol 2 with high yields and excellent enantioselectivity (up to 98% ee). It should be noted that this alkyaltion reaction proceeds well using air- and moisture-stable chiral palladium com- plexes with low loading (1 mol%)

  19. PALLADIUM-FACILITATED ELECTROLYTIC DECHLORINATION OF 2-CHLOROBIPHENYL USING A GRANULAR-GRAPHITE ELECTRODE.

    Science.gov (United States)

    Palladium-assisted electrocatalytic dechlorination of 2-chlorobiphenyl (2-Cl BP) in aqueous solutions was conducted in a membrane-separated electrochemical reactor with granular-graphite packed electrodes. The dechlorination took place at a granular-graphite cathode while Pd was ...

  20. Unsupported palladium alloy membranes and methods of making same

    Science.gov (United States)

    Way, J. Douglas; Thoen, Paul; Gade, Sabina K.

    2015-06-02

    The invention provides support-free palladium membranes and methods of making these membranes. Single-gas testing of the unsupported foils produced hydrogen permeabilities equivalent to thicker membranes produced by cold-rolling. Defect-free films as thin as 7.2 microns can be fabricated, with ideal H.sub.2/N.sub.2 selectivities as high as 40,000. Homogeneous membrane compositions may also be produced using these methods.

  1. PVP-Stabilized Palladium Nanoparticles in Silica as Effective Catalysts for Hydrogenation Reactions

    Directory of Open Access Journals (Sweden)

    Caroline Pires Ruas

    2013-01-01

    Full Text Available Palladium nanoparticles stabilized by poly (N-vinyl-2-pyrrolidone (PVP can be synthesized by corresponding Pd(acac2 (acac = acetylacetonate as precursor in methanol at 80°C for 2 h followed by reduction with NaBH4 and immobilized onto SiO2 prepared by sol-gel process under acidic conditions (HF or HCl. The PVP/Pd molar ratio is set to 6. The effect of the sol-gel catalyst on the silica morphology and texture and on Pd(0 content was investigated. The catalysts prepared (ca. 2% Pd(0/SiO2/HF and ca. 0,3% Pd(0/SiO2/HCl were characterized by TEM, FAAS, and SEM-EDS. Palladium nanoparticles supported in silica with a size 6.6 ± 1.4 nm were obtained. The catalytic activity was tested in hydrogenation of alkenes.

  2. Preparation of fluorinated biaryls through direct palladium-catalyzed coupling of polyfluoroarenes with aryltrifluoroborates

    KAUST Repository

    Fang, Xin; Huang, Yuanyuan; Chen, Xiaoqing; Lin, Xiaoxi; Bai, Zhengshuai; Huang, Kuo-Wei; Yuan, Yaofeng; Weng, Zhiqiang

    2013-01-01

    The direct palladium-catalyzed coupling of polyfluoroarenes with aryltrifluoroborates gave the desired products of fluorinated biaryls in good to excellent yields. A diverse set of important functional groups including methoxy, aldehyde, ester

  3. Mechanism of reductive elimination. Reaction of alkylpalladium(II) complexes with tetraorganotin, organolithium, and Grignard reagents. Evidence for palladium(IV) intermediacy

    International Nuclear Information System (INIS)

    Milstein, D.; Stille, J.K.

    1979-01-01

    Coupling products are obtained in good yields from the reaction of tetraorganotin compounds or Grignard reagents and organohalogenopalladium(II) complexes provided that a benzyl bromide is present. Low yields are obtained in the absence of the benzyl bromides, in which case other decomposition pathways (e.g., α elimination) take place, even in the presence of electron acceptors (e.g., oxygen, m-dinitrobenzene). The first step in the reaction of benzylhalogenobis(triphenylphosphine)-palladium(II) complexes with MeM (M = SnMe 3 , MgBr) is metathesis of the benzyl ligand rather than the halogen. This unique carbon-for-carbon transmetalation takes place at 25 0 C and is facilitated by electron-donating substituents on the benzyl ligand. The products of this reaction subsequently react at higher temperature in the presence of a benzyl bromide to afford ethylbenzene. Optically active chloro-(α-deuteriobenzyl)bis(triphenylphosphine)palladium yields, upon reaction with tetramethyltin in the presence of p-nitrobenzyl bromide, optically active α-deuterioethylbenzene in which overall retention of configuration at carbon has resulted. cis-dimethylbis(triphenylphosphine)palladium(II) reacts with benzyl bromide at 25 0 C to afford ethylbenzene and bromomethylbis(triphenylphosphine)palladium(II) rather than ethane. When optically active α-deuteriobenzyl bromide is used in this reaction, optically active α-deuterioethylbenzene is formed, and inversion of configuration at carbon takes place. The reductive elimination process is proposed to take place preferentially from a palladium(IV) intermediate with retention of configuration at carbon

  4. Electrooxidation of aliphatic alcohols on palladium oxide catalyst prepared by pulsed electrodeposition technique

    International Nuclear Information System (INIS)

    Casella, Innocenzo G.

    2009-01-01

    Palladium film can be deposited on gold polycrystalline electrodes, from a deoxygenated alkaline solution containing 50 mM NaOH plus 0.5 mM K 2 Pd(CN) 4 . A multipulse sequence of potentials of equal amplitude and duration was used for the palladium deposition process. In particular, an optimized waveform of potentials of E 1 = 1.0 V vs. SCE and E 2 = -1.0 V vs. SCE for the relevant pulse duration of t 1 = 0.05 s and t 2 = 0.05 s, for 30 s, was used. Cyclic voltammetry and scanning electron microscopy (SEM) were employed to characterize the gold-palladium modified electrode (Au-Pd) towards the electrooxidation of aliphatic alcohols in alkaline solutions. The voltammetric study suggests that the kinetics involved in the alcohol electrooxidation at the Pd-Au electrode are sensibly higher than those observed on the bare Pd and Au electrodes. In addition, the most interesting aspect of the electrooxidation of aliphatic alcohols at the Au-Pd electrode was that as the number of methylene groups on the homologous series of aliphatic alcohols increased, the molar response also increased. Under pulsed chronoamerometric conditions (PCC), using an optimized triple pulse waveform of potentials the modified electrode exhibits interesting catalytic currents without any apparent poisoning effects during the oxidation of aliphatic alcohols.

  5. On the possibility of deuteron disintegration in electrochemically compressed D+ in a palladium cathode

    International Nuclear Information System (INIS)

    Ragheb, M.; Miley, G.H.

    1989-01-01

    The possibility of deuteron disintegration due to polarization in the coulomb field of a target nucleus according to an Oppenheimer-Phillips process is discussed within the context of electrochemically compressed D + in a palladium cathode. This reaction is possible between deuterons and palladium isotopes, as well as between the deuterons themselves. In the last case, the equivalent of the proton branch of the deuterium-deuterium fusion reaction occurs in preference to the neutron branch. The process provides a possible explanation for the observed energy release, tritium production, and neutron suppression in the Fleischmann and Pons experiment. If such a process can be experimentally verified, analogous processes leading to the disintegration of the 9 Be nucleus may be achievable

  6. A New Thermodynamic Calculation Method for Binary Alloys: Part I: Statistical Calculation of Excess Functions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The improved form of calculation formula for the activities of the components in binary liquids and solid alloys has been derived based on the free volume theory considering excess entropy and Miedema's model for calculating the formation heat of binary alloys. A calculation method of excess thermodynamic functions for binary alloys, the formulas of integral molar excess properties and partial molar excess properties for solid ordered or disordered binary alloys have been developed. The calculated results are in good agreement with the experimental values.

  7. Catalytic wet oxidation of ammonia solution: Activity of the nanoscale platinum-palladium-rhodium composite oxide catalyst

    International Nuclear Information System (INIS)

    Hung, C.-M.

    2009-01-01

    Aqueous solutions of 400-1000 mg/L of ammonia were oxidized in a trickle-bed reactor (TBR) in this study of nanoscale platinum-palladium-rhodium composite oxide catalysts, which were prepared by the co-precipitation of H 2 PtCl 6 , Pd(NO 3 ) 3 and Rh(NO 3 ) 3 . Hardly any of the dissolved ammonia was removed by wet oxidation in the absence of any catalyst, whereas about 99% of the ammonia was reduced during wet oxidation over nanoscale platinum-palladium-rhodium composite oxide catalysts at 503 K in an oxygen partial pressure of 2.0 MPa. A synergistic effect exists in the nanoscale platinum-palladium-rhodium composite structure, which is the material with the highest ammonia reduction activity. The nanometer-sized particles were characterized by TEM, XRD and FTIR. The effect of the initial concentration and reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid hourly space velocity of under 9 h -1 in the wet catalytic processes

  8. Catalytic wet oxidation of ammonia solution: Activity of the nanoscale platinum-palladium-rhodium composite oxide catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Hung, C.-M. [Department of Industry Engineering and Management, Yung-Ta Institute of Technology and Commerce, 316 Chung-shan Road, Linlo, Pingtung 909, Taiwan (China)], E-mail: hungcm1031@gmail.com

    2009-04-15

    Aqueous solutions of 400-1000 mg/L of ammonia were oxidized in a trickle-bed reactor (TBR) in this study of nanoscale platinum-palladium-rhodium composite oxide catalysts, which were prepared by the co-precipitation of H{sub 2}PtCl{sub 6}, Pd(NO{sub 3}){sub 3} and Rh(NO{sub 3}){sub 3}. Hardly any of the dissolved ammonia was removed by wet oxidation in the absence of any catalyst, whereas about 99% of the ammonia was reduced during wet oxidation over nanoscale platinum-palladium-rhodium composite oxide catalysts at 503 K in an oxygen partial pressure of 2.0 MPa. A synergistic effect exists in the nanoscale platinum-palladium-rhodium composite structure, which is the material with the highest ammonia reduction activity. The nanometer-sized particles were characterized by TEM, XRD and FTIR. The effect of the initial concentration and reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid hourly space velocity of under 9 h{sup -1} in the wet catalytic processes.

  9. Catalytic wet oxidation of ammonia solution: activity of the nanoscale platinum-palladium-rhodium composite oxide catalyst.

    Science.gov (United States)

    Hung, Chang-Mao

    2009-04-15

    Aqueous solutions of 400-1000 mg/L of ammonia were oxidized in a trickle-bed reactor (TBR) in this study of nanoscale platinum-palladium-rhodium composite oxide catalysts, which were prepared by the co-precipitation of H(2)PtCl(6), Pd(NO(3))(3) and Rh(NO(3))(3). Hardly any of the dissolved ammonia was removed by wet oxidation in the absence of any catalyst, whereas about 99% of the ammonia was reduced during wet oxidation over nanoscale platinum-palladium-rhodium composite oxide catalysts at 503 K in an oxygen partial pressure of 2.0 MPa. A synergistic effect exists in the nanoscale platinum-palladium-rhodium composite structure, which is the material with the highest ammonia reduction activity. The nanometer-sized particles were characterized by TEM, XRD and FTIR. The effect of the initial concentration and reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid hourly space velocity of under 9 h(-1) in the wet catalytic processes.

  10. Interaction of 2-aminopyrimidine with dichloro-[1-alkyl-2-(naphthylazo imidazole]palladium(II complexes : Kinetic and mechanistic studies

    Directory of Open Access Journals (Sweden)

    Saha Sushanta

    2007-10-01

    Full Text Available Abstract Background The anticancer properties of cisplatin and palladium(II complexes stem from the ability of the cis-MCl2 fragment to bind to DNA bases. However, cisplatin also interacts with non-cancer cells, mainly through bonding molecules containing -SH groups, resulting in nephrotoxicity. This has aroused interest in the design of palladium(II complexes of improved activity and lower toxicity. The reaction of DNA bases with palladium(II complexes with chelating N,N/donors of the cis-MCl2 configuration constitutes a model system that may help explore the mechanism of cisplatin's anticancer activity. Heterocyclic compounds are found widely in nature and are essential to many biochemical processes. Amongst these naturally occurring compounds, the most thoroughly studied is that of pyrimidine. This was one of the factors that encouraged this study into the kinetics and mechanism of the interaction of 2-aminopyrimidine (2-NH2-Pym with dichloro-{1-alkyl-2-(α-naphthylazoimidazole}palladium(II [Pd(α-NaiRCl2, 1] and dichloro-{1-alkyl-2-(β-naphthylazoimidazole}palladium(II [Pd(β-NaiRCl2, 2] complexes where the alkyl R = Me (a, Et (b, or Bz (c. Results 2-NH2-Pym reacts with 1a, 1b, and 1c to yield [{1-alkyl-2-(α-naphthylazoimidazole}bis(2-aminopyrimidine]palladium(II (3a, 3b, 3c dichloride and with 2a, 2b, and 2c to yield [{1-alkyl-2-(β-naphthylazoimidazole}bis(2-aminopyrimidine]palladium(II (4a, 4b, 4c dichloride in an acetonitrile (MeCN medium. The products were characterized using spectroscopic techniques (FT-IR, UV-Vis, NMR. The ligand substitution reactions follow second order kinetics – first order dependence on the concentration of the Pd(II complex and 2-NH2-Pym. Addition of LiCl to the reaction does not influence its rate. The thermodynamic parameters (standard enthalpy of activation, Δ‡H° and standard entropy of activation, Δ‡S° were determined from variable temperature kinetic studies. The magnitude of the second order

  11. Dechlorination of Environmental Contaminants Using a Hybrid Nanocatalyst: Palladium Nanoparticles Supported on Hierarchical Carbon Nanostructures

    Directory of Open Access Journals (Sweden)

    Hema Vijwani

    2012-01-01

    Full Text Available This paper demonstrates the effectiveness of a new type of hybrid nanocatalyst material that combines the high surface area of nanoparticles and nanotubes with the structural robustness and ease of handling larger supports. The hybrid material is made by fabricating palladium nanoparticles on two types of carbon supports: as-received microcellular foam (Foam and foam with carbon nanotubes anchored on the pore walls (CNT/Foam. Catalytic reductive dechlorination of carbon tetrachloride with these materials has been investigated using gas chromatography. It is seen that while both palladium-functionalized carbon supports are highly effective in the degradation of carbon tetrachloride, the rate of degradation is significantly increased with palladium on CNT/Foam. However, there is scope to increase this rate further if the wettability of these structures can be enhanced in the future. Microstructural and spectroscopic analyses of the fresh and used catalysts have been compared which indicates that there is no change in density or surface chemical states of the catalyst after prolonged use in dechlorination test. This implies that these materials can be used repeatedly and hence provide a simple, powerful, and cost-effective approach for dechlorination of water.

  12. SU-F-T-39: Comparing Nomograms for Ordering of Palladium-103 Seeds for Dynamic Intraoperative Prostate Seed Implantation

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, P; Wang, L; Riegel, A [Northwell Health, Lake Success, NY (United States)

    2016-06-15

    Purpose: Several nomograms exist for the purpose of ordering palladium- 103 seeds for permanent prostate seed implants. Excess seeds pose additional radiation safety risks and increase the cost of care. This study compared three seed ordering nomograms with seed counts from dynamic intra-operative PSI to determine (1) the cause of excess seeds and (2) the optimal nomogram for our institution. Methods: Pre-operative and intra-operative clinical data were collected for 100 Gy (n=151) and 125 Gy (n=224) prostate seed implants. The number of implanted seeds which would have given D90=100% was normalized to that criteria and seed strength of 2U. This was plotted against intra-operative prostate volume and compared to two previously published nomograms and an in-house nomogram. A linear fit was produced and confidence intervals were calculated. The causes of excess seeds were assessed by comparing pre- and intra-operative prostate volumes, variability of D90 around 100%, and variance of seed strength from 2U. Results: Of the 375 total cases, 97.6% had excess seeds. On average, 27.17±12.91% of ordered seeds were wasted. Of this percentage, 6.98±5.47% of excess seeds were due to overestimation of pre-operative prostate volume, 1.10±0.88% were due to D90<100%, 1.17±0.67% were due to seed strength over 2U, and 17.36±7.79% could not be directly attributed to a specific reason. The latter percentage may be due to overestimation of the in-house nomogram. Two of three nomograms substantially overestimated the number of seeds required. The third nomogram underestimated the required seed number for smaller prostate treatment volume. A linear fit to the clinical data was derived and 99.9% confidence intervals were calculated. Conclusion: Over 85% of clinical cases wasted over 15% of ordered seeds. Two of three nomograms overestimated the required number of seeds. The upper 99.9% C.I. of the clinical data may provide a more reasonable nomogram for Pd-103 seed ordering.

  13. SU-F-T-39: Comparing Nomograms for Ordering of Palladium-103 Seeds for Dynamic Intraoperative Prostate Seed Implantation

    International Nuclear Information System (INIS)

    Taylor, P; Wang, L; Riegel, A

    2016-01-01

    Purpose: Several nomograms exist for the purpose of ordering palladium- 103 seeds for permanent prostate seed implants. Excess seeds pose additional radiation safety risks and increase the cost of care. This study compared three seed ordering nomograms with seed counts from dynamic intra-operative PSI to determine (1) the cause of excess seeds and (2) the optimal nomogram for our institution. Methods: Pre-operative and intra-operative clinical data were collected for 100 Gy (n=151) and 125 Gy (n=224) prostate seed implants. The number of implanted seeds which would have given D90=100% was normalized to that criteria and seed strength of 2U. This was plotted against intra-operative prostate volume and compared to two previously published nomograms and an in-house nomogram. A linear fit was produced and confidence intervals were calculated. The causes of excess seeds were assessed by comparing pre- and intra-operative prostate volumes, variability of D90 around 100%, and variance of seed strength from 2U. Results: Of the 375 total cases, 97.6% had excess seeds. On average, 27.17±12.91% of ordered seeds were wasted. Of this percentage, 6.98±5.47% of excess seeds were due to overestimation of pre-operative prostate volume, 1.10±0.88% were due to D90<100%, 1.17±0.67% were due to seed strength over 2U, and 17.36±7.79% could not be directly attributed to a specific reason. The latter percentage may be due to overestimation of the in-house nomogram. Two of three nomograms substantially overestimated the number of seeds required. The third nomogram underestimated the required seed number for smaller prostate treatment volume. A linear fit to the clinical data was derived and 99.9% confidence intervals were calculated. Conclusion: Over 85% of clinical cases wasted over 15% of ordered seeds. Two of three nomograms overestimated the required number of seeds. The upper 99.9% C.I. of the clinical data may provide a more reasonable nomogram for Pd-103 seed ordering.

  14. Immobilization of Highly Effective Palladium Catalyst onto Poly(4-Vinylpyridine): Synthesis and Characterization

    International Nuclear Information System (INIS)

    Siti Kamilah Che Soh; Intan Shafinass Kassim; Siti Aminah Jusoh; Mustaffa Samsuddin

    2016-01-01

    A commonly known weakness of homogeneous catalysts is the difficulty to recover the active catalyst from the product. Due to the disadvantage, the designing of supported catalyst has been approached to overcome the separation difficulty of the palladium-based homogeneous catalyst. New polymer supported N 2 O 2 metal complex was successfully immobilized by mixing of poly(4-vinylpyridine) with palladium(II) complex in the presence of ethyl acetate as solvent. Then, the reaction was stirred for 72 hours at room temperature to form corresponding P 4 VP-Pd catalyst. The properties of immobilized catalyst were characterized by various techniques such as fourier transform infrared (FTIR), thermogravimetric (TGA), X-ray diffraction (XRD), scanning electron microscopy/ energy dispersive X-ray (SEM/ EDX) and inductively coupled plasma-optical emission (ICP-OES) spectroscopy. (author)

  15. Performance of palladium nanoparticle–graphene composite as an efficient electrode material for electrochemical double layer capacitors

    International Nuclear Information System (INIS)

    Dar, Riyaz A.; Giri, Lily; Karna, Shashi P.; Srivastava, Ashwini K.

    2016-01-01

    Highlights: • Single step synthesis of palladium nanoparticles decorated-graphene nanocomposite. • Improved electron transfer kinetics and superior capacitive performance. • High specific capacitance of 637 F g −1 at a current density of 1.25 A g −1 . • Retention of 91.4% of its initial capacitance after 10000 cycles of testing. - Abstract: Palladium nanoparticle–graphene nanosheet composite (PdNP–GN) is demonstrated as an efficient electrode material in energy storage applications in supercapacitors. Palladium nanoparticle (PdNP) decorated graphene nanosheet (GN) composite was synthesized via a chemical approach in a single step by the simultaneous reduction of graphene oxide (GO) and palladium chloride from the aqueous phase using ascorbic acid as reducing agent. The materials were characterized by scanning and high resolution transmission electron microscopy, Raman, X-ray diffraction and energy dispersive X-ray spectroscopy which demonstrate that the metal nanoparticles have been uniformly deposited on the surface of graphene nanosheets. The synthesized material has been analyzed by cyclic voltammetry, electrochemical impedance spectrometry and chronopotentiometry using 1 M KCl as the supporting electrolyte for its application in electrochemical double layer supercapacitors. PdNPs-GN composite showed improved electron transfer kinetics and superior capacitive performance with large specific capacitance of 637 F g −1 , excellent cyclic performance and maximum energy and power densities of 56 Wh kg −1 and 1166 W kg −1 , respectively at a current density of 1.25 A g −1 . This highlights the importance of the synergetic effects of electrochemically efficient Pd nanoparticles and graphene for energy storage applications in supercapacitors.

  16. Cloud point extraction of palladium in water samples and alloy mixtures using new synthesized reagent with flame atomic absorption spectrometry (FAAS)

    International Nuclear Information System (INIS)

    Priya, B. Krishna; Subrahmanayam, P.; Suvardhan, K.; Kumar, K. Suresh; Rekha, D.; Rao, A. Venkata; Rao, G.C.; Chiranjeevi, P.

    2007-01-01

    The present paper outlines novel, simple and sensitive method for the determination of palladium by flame atomic absorption spectrometry (FAAS) after separation and preconcentration by cloud point extraction (CPE). The cloud point methodology was successfully applied for palladium determination by using new reagent 4-(2-naphthalenyl)thiozol-2yl azo chromotropic acid (NTACA) and hydrophobic ligand Triton X-114 as chelating agent and nonionic surfactant respectively in the water samples and alloys. The following parameters such as pH, concentration of the reagent and Triton X-114, equilibrating temperature and centrifuging time were evaluated and optimized to enhance the sensitivity and extraction efficiency of the proposed method. The preconcentration factor was found to be (50-fold) for 250 ml of water sample. Under optimum condition the detection limit was found as 0.067 ng ml -1 for palladium in various environmental matrices. The present method was applied for the determination of palladium in various water samples, alloys and the result shows good agreement with reported method and the recoveries are in the range of 96.7-99.4%

  17. A Palladium-Catalyzed Vinylcyclopropane (3 + 2) Cycloaddition Approach to the Melodinus Alkaloids

    KAUST Repository

    Goldberg, Alexander F. G.

    2011-08-19

    A palladium-catalyzed (3+2) cycloaddition of a vinylcyclopropane and a β-nitrostyrene is employed to rapidly assemble the cyclopentane core of the Melodinus alkaloids. The ABCD ring system of the natural product family is prepared in six steps from commercially available materials.

  18. Practical and General Palladium-Catalyzed Synthesis of Ketones from Internal Olefins

    KAUST Repository

    Morandi, Bill

    2013-01-16

    Make it simple! A convenient and general palladium-catalyzed oxidation of internal olefins to ketones is reported. The transformation occurs at room temperature and shows wide substrate scope. Applications to the oxidation of seed-oil derivatives and a bioactive natural product (see scheme) are described, as well as intriguing mechanistic features.

  19. Reactivation of a Palladium Catalyst during Glucose Oxidation by Molecular Oxygen

    Czech Academy of Sciences Publication Activity Database

    Gogová, Zuzana; Hanika, Jiří

    2009-01-01

    Roč. 63, č. 5 (2009), s. 520-526 ISSN 0366-6352 R&D Projects: GA ČR(CZ) GD203/08/H032 Institutional research plan: CEZ:AV0Z40720504 Keywords : glucose * palladium catalyst * deactivation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.791, year: 2009

  20. Practical and General Palladium-Catalyzed Synthesis of Ketones from Internal Olefins

    KAUST Repository

    Morandi, Bill; Wickens, Zachary K.; Grubbs, Robert H.

    2013-01-01

    Make it simple! A convenient and general palladium-catalyzed oxidation of internal olefins to ketones is reported. The transformation occurs at room temperature and shows wide substrate scope. Applications to the oxidation of seed-oil derivatives and a bioactive natural product (see scheme) are described, as well as intriguing mechanistic features.

  1. Palladium on Nitrogen-Doped Mesoporous Carbon: A Bifunctional Catalyst for Formate-Based, Carbon-Neutral Hydrogen Storage.

    Science.gov (United States)

    Wang, Fanan; Xu, Jinming; Shao, Xianzhao; Su, Xiong; Huang, Yanqiang; Zhang, Tao

    2016-02-08

    The lack of safe, efficient, and economical hydrogen storage technologies is a hindrance to the realization of the hydrogen economy. Reported herein is a reversible formate-based carbon-neutral hydrogen storage system that is established over a novel catalyst comprising palladium nanoparticles supported on nitrogen-doped mesoporous carbon. The support was fabricated by a hard template method and nitridated under a flow of ammonia. Detailed analyses demonstrate that this bicarbonate/formate redox equilibrium is promoted by the cooperative role of the doped nitrogen functionalities and the well-dispersed, electron-enriched palladium nanoparticles. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Separation of gold, palladium and platinum in chromite by anion exchange chromatography for inductively coupled plasma atomic emission spectrometric analysis

    International Nuclear Information System (INIS)

    Choi, Kwang Soon; Lee, Chang Heon; Park, Yeong Jae; Joe, Kih Soo; Kim, Won Ho

    2001-01-01

    A study has been carried out on the separation of gold, iridium, palladium, rhodium, ruthenium and platinum in chromite samples and their quantitative determination using inductively coupled plasma atomic emission spectrometry (ICP-AES). The dissolution condition of the minerals by fusion with sodium peroxide was optimized and chromatographic elution behavior of the rare metals was investigated by anion exchange chromatography. Spectral interference of chromium, a matrix of the minerals, was investigated on determination of gold. Chromium interfered on determination of gold at the concentration of 500 mg/L and higher. Gold plus trace amounts of iridium, palladium, rhodium and ruthenium, which must be preconcentrated before ICP-AES was separated by anion exchange chromatography after reducing Cr(VI) to Cr(III) by H 2 O 2 . AuCl - 4 retained on the resin column was selectively eluted with acetone- HNO 3 -H 2 O as an eluent. In addition, iridium, palladium, rhodium and ruthenium remaining on the resin column were eluted as a group with concentrated HCl. However, platinum was eluted with concentrated HNO 3 . The recovery yield of gold with acetone-HNO 3 -H 2 O was 100.7 ± 2.0 % , and the yields of palladium and platinum with concentrated HCl and HNO 3 were 96.1 ± 1.8% and 96.6 ± 1.3%, respectively. The contents of gold and platinum in a Mongolian chromite sample were 32.6 ± 2.2 μg/g and 1.6 ± 0.14 μg/g, respectively. Palladium was not detected

  3. Palladium polypyridyl complexes: synthesis, characterization, DNA interaction and biological activity on Leishmania (L.) mexicana

    International Nuclear Information System (INIS)

    Navarro, Maribel; Betancourt, Adelmo; Hernandez, Clara; Marchan, Edgar

    2008-01-01

    This paper describes the search for new potential chemotherapeutic agents based on transition metal complexes with planar ligands. In this study, palladium polypyridyl complexes were synthesized and characterized by elemental analysis, NMR, UV-VIS and IR spectroscopies. The interaction of the complexes with DNA was also investigated by spectroscopic methods. All metal-to-ligand charge transfer (MLCT) bands of the palladium polypyridyl complexes exhibited hypochromism and red shift in the presence of DNA. The binding constant and viscosity data suggested that the complexes [PdCl 2 (phen)] and [PdCl 2 (phendiamine)] interact with DNA by electrostatic forces. Additionally, these complexes induced an important leishmanistatic effect on L. (L.) mexicana promastigotes at the final concentration of 10 μmol L -1 in 48 h. (author)

  4. Synthesis of Nitriles via Palladium-Catalyzed Water Shuffling from Amides to Acetonitrile

    OpenAIRE

    Zhang, Wandi; Haskins, Christopher W.; Yang, Yang; Dai, Mingji

    2014-01-01

    Palladium-catalyzed synthesis of nitriles from amides has been described. Two similar, but complementary reaction conditions have been identified to convert various amides including α,β,γ,δ-unsaturated amides, cinnamides, aromatic amides and alkyl amides to the corresponding nitriles in good to excellent yield.

  5. Synthesis of nitriles via palladium-catalyzed water shuffling from amides to acetonitrile.

    Science.gov (United States)

    Zhang, Wandi; Haskins, Christopher W; Yang, Yang; Dai, Mingji

    2014-12-07

    Palladium-catalyzed synthesis of nitriles from amides has been described. Two similar, but complementary reaction conditions have been identified to convert various amides including α,β,γ,δ-unsaturated amides, cinnamides, aromatic amides and alkyl amides to the corresponding nitriles in good to excellent yield.

  6. Developing a Procedure for Segmenting Meshed Heat Networks of Heat Supply Systems without Outflows

    Science.gov (United States)

    Tokarev, V. V.

    2018-06-01

    The heat supply systems of cities have, as a rule, a ring structure with the possibility of redistributing the flows. Despite the fact that a ring structure is more reliable than a radial one, the operators of heat networks prefer to use them in normal modes according to the scheme without overflows of the heat carrier between the heat mains. With such a scheme, it is easier to adjust the networks and to detect and locate faults in them. The article proposes a formulation of the heat network segmenting problem. The problem is set in terms of optimization with the heat supply system's excessive hydraulic power used as the optimization criterion. The heat supply system computer model has a hierarchically interconnected multilevel structure. Since iterative calculations are only carried out for the level of trunk heat networks, decomposing the entire system into levels allows the dimensionality of the solved subproblems to be reduced by an order of magnitude. An attempt to solve the problem by fully enumerating possible segmentation versions does not seem to be feasible for systems of really existing sizes. The article suggests a procedure for searching rational segmentation of heat supply networks with limiting the search to versions of dividing the system into segments near the flow convergence nodes with subsequent refining of the solution. The refinement is performed in two stages according to the total excess hydraulic power criterion. At the first stage, the loads are redistributed among the sources. After that, the heat networks are divided into independent fragments, and the possibility of increasing the excess hydraulic power in the obtained fragments is checked by shifting the division places inside a fragment. The proposed procedure has been approbated taking as an example a municipal heat supply system involving six heat mains fed from a common source, 24 loops within the feeding mains plane, and more than 5000 consumers. Application of the proposed

  7. Microscale Regenerative Heat Exchanger

    Science.gov (United States)

    Moran, Matthew E.; Stelter, Stephan; Stelter, Manfred

    2006-01-01

    The device described herein is designed primarily for use as a regenerative heat exchanger in a miniature Stirling engine or Stirling-cycle heat pump. A regenerative heat exchanger (sometimes called, simply, a "regenerator" in the Stirling-engine art) is basically a thermal capacitor: Its role in the Stirling cycle is to alternately accept heat from, then deliver heat to, an oscillating flow of a working fluid between compression and expansion volumes, without introducing an excessive pressure drop. These volumes are at different temperatures, and conduction of heat between these volumes is undesirable because it reduces the energy-conversion efficiency of the Stirling cycle.

  8. Palladium(II)-catalyzed desulfitative synthesis of aryl ketones from sodium arylsulfinates and nitriles: scope, limitations, and mechanistic studies.

    Science.gov (United States)

    Skillinghaug, Bobo; Sköld, Christian; Rydfjord, Jonas; Svensson, Fredrik; Behrends, Malte; Sävmarker, Jonas; Sjöberg, Per J R; Larhed, Mats

    2014-12-19

    A fast and efficient protocol for the palladium(II)-catalyzed production of aryl ketones from sodium arylsulfinates and various organic nitriles under controlled microwave irradiation has been developed. The wide scope of the reaction has been demonstrated by combining 14 sodium arylsulfinates and 21 nitriles to give 55 examples of aryl ketones. One additional example illustrated that, through the choice of the nitrile reactant, benzofurans are also accessible. The reaction mechanism was investigated by electrospray ionization mass spectrometry and DFT calculations. The desulfitative synthesis of aryl ketones from nitriles was also compared to the corresponding transformation starting from benzoic acids. Comparison of the energy profiles indicates that the free energy requirement for decarboxylation of 2,6-dimethoxybenzoic acid and especially benzoic acid is higher than the corresponding desulfitative process for generating the key aryl palladium intermediate. The palladium(II) intermediates detected by ESI-MS and the DFT calculations provide a detailed understanding of the catalytic cycle.

  9. A new metal electrocatalysts supported matrix: Palladium nanoparticles supported silicon carbide nanoparticles and its application for alcohol electrooxidation

    International Nuclear Information System (INIS)

    Dai Hong; Chen Yanling; Lin Yanyu; Xu Guifang; Yang Caiping; Tong Yuejin; Guo Longhua; Chen Guonan

    2012-01-01

    In this paper, we propose a facile approach for palladium nanoparticles load using silicon carbide nanoparticles as the new supported matrix and a familiar NaBH 4 as reducer. Detailed X-ray photoelectron spectrum (XPS) and transmission electron microscopy (TEM) analysis of the resultant products indicated that palladium nanoparticles are successfully immobilized onto the surface of the silicon carbide nanoparticles with uniform size distribution between 5 and 7 nm. The relative electrochemical characterization clearly demonstrated excellent electrocatalytic activity of this material toward alcohol in alkaline electrolytes. Investigation on the characteristics of the electrocatalytic activity of this material further indicated that the palladium nanoparticles supporting on SiC are very promising for direct alcohol fuel cells (DMFCs), biosensor and electronic devices. Moreover, it was proved that silicon carbide nanoparticles with outstanding properties as support for catalysis are of strong practical interest. And the silicon carbide could perform attractive role in adsorbents, electrodes, biomedical applications, etc.

  10. Excess Molar Volume, Viscosity and Heat Capacity for the Binary Mixture of p-Xylene and Acetic Acid at Different Temperatures%对二甲苯和醋酸二元液体混合物在不同温度下的超额摩尔体积、粘度和热容

    Institute of Scientific and Technical Information of China (English)

    杨长生; 马沛生; 唐多强; 尹秋响; 赵长伟

    2002-01-01

    Experimental densities, viscosities and heat capacities at different temperatures were presented overthe entire range of mole fraction for the binary mixture of p-xylene and acetic acid. Density values were used in thedetermination of excess molar volumes, VE. At the same time, the excess viscosity and excess molar heat capacitieswere calculated. The values of VE, ηE and cpE were fitted to the Redlich-Kister equation. Good agreements wereobserved. The excess molar volumes are positive with a large maximum value located in the central concentrationrange. The excess viscosity has an opposite trend to the excess molar volume VE. ηE values are negative over theentire range of the mixture. The cure of dependence of cEp on concentration has a special shape. The molecularinteraction between p-xylene and acetic acid is discussed.

  11. Application of heat pipes in nuclear reactors for passive heat removal

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Z.; Yetisir, M., E-mail: haquez@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-07-01

    This paper introduces a number of potential heat pipe applications in passive (i.e., not requiring external power) nuclear reactor heat removal. Heat pipes are particularly suitable for small reactors as the demand for heat removal is significantly less than commercial nuclear power plants, and passive and reliable heat removal is required. The use of heat pipes has been proposed in many small reactor designs for passive heat removal from the reactor core. This paper presents the application of heat pipes in AECL's Nuclear Battery design, a small reactor concept developed by AECL. Other potential applications of heat pipes include transferring excess heat from containment to the atmosphere by integrating low-temperature heat pipes into the containment building (to ensure long-term cooling following a station blackout), and passively cooling spent fuel bays. (author)

  12. Dinuclear Tetrapyrazolyl Palladium Complexes Exhibiting Facile Tandem Transfer Hydrogenation/Suzuki Coupling Reaction of Fluoroarylketone

    KAUST Repository

    Dehury, Niranjan; Maity, Niladri; Tripathy, Suman Kumar; Basset, Jean-Marie; Patra, Srikanta

    2016-01-01

    Herein, we report an unprecedented example of dinuclear pyrazolyl-based Pd complexes exhibiting facile tandem catalysis for fluoroarylketone: Tetrapyrazolyl di-palladium complexes with varying Pd-Pd distances efficiently catalyze the tandem reaction

  13. Palladium-catalyzed aerobic oxidative cross-coupling of arylhydrazines with terminal alkynes.

    Science.gov (United States)

    Zhao, Yingwei; Song, Qiuling

    2015-09-04

    The palladium-catalyzed Sonogashira-type aerobic oxidative coupling of arylhydrazines with terminal alkynes via C-N bond cleavage has been developed; internal alkynes were afforded with a broad substrate scope. This reaction proceeds under copper- and base-free conditions with molecular oxygen as the sole oxidant and nitrogen and water as the only by-products.

  14. Palladium nanoparticles anchored on graphene nanosheets: Methanol, ethanol oxidation reactions and their kinetic studies

    Energy Technology Data Exchange (ETDEWEB)

    Nagaraju, D.H., E-mail: dhnagu@gmail.com [Department of Mechanical Engineering, 117 576 (Singapore); Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 (Saudi Arabia); Devaraj, S. [Department of Mechanical Engineering, 117 576 (Singapore); School of Chemical and Biotechnology, SASTRA University, Thanjavur, 613 401 (India); Balaya, P., E-mail: mpepb@nus.edu.sg [Department of Mechanical Engineering, 117 576 (Singapore); Engineering Science Program, National University of Singapore, 117 576 (Singapore)

    2014-12-15

    Highlights: • Palladium nanoparticles decorated graphene is synthesized in a single step. • Electro-catalytic activity of Gra/Pd toward alcohol oxidation is evaluated. • 1:1 Gra/Pd exhibits good electro-catalytic activity and efficient electron transfer. - Abstract: Palladium nanoparticles decorated graphene (Gra/Pd nanocomposite) was synthesized by simultaneous chemical reduction of graphene oxide and palladium salt in a single step. The negatively charged graphene oxide (GO) facilitates uniform distribution of Pd{sup 2+} ions onto its surface. The subsequent reduction by hydrazine hydrate provides well dispersed Pd nanoparticles decorated graphene. Different amount of Pd nanoparticles on graphene was synthesized by changing the volume to weight ratio of GO to PdCl{sub 2}. X-ray diffraction studies showed FCC lattice of Pd with predominant (1 1 1) plane. SEM and TEM studies revealed that thin graphene nanosheets are decorated by Pd nanoparticles. Raman spectroscopic studies revealed the presence of graphene nanosheets. The electro-catalytic activity of Gra/Pd nanocomposites toward methanol and ethanol oxidation in alkaline medium was evaluated by cyclic voltammetric studies. 1:1 Gra/Pd nanocomposite exhibited good electro-catalytic activity and efficient electron transfer. The kinetics of electron transfer was studied using chronoamperometry. Improved electro-catalytic activity of 1:1 Gra/Pd nanocomposite toward alcohol oxidation makes it as a potential anode for the alcohol fuel cells.

  15. Palladium nanoparticles anchored on graphene nanosheets: Methanol, ethanol oxidation reactions and their kinetic studies

    International Nuclear Information System (INIS)

    Nagaraju, D.H.; Devaraj, S.; Balaya, P.

    2014-01-01

    Highlights: • Palladium nanoparticles decorated graphene is synthesized in a single step. • Electro-catalytic activity of Gra/Pd toward alcohol oxidation is evaluated. • 1:1 Gra/Pd exhibits good electro-catalytic activity and efficient electron transfer. - Abstract: Palladium nanoparticles decorated graphene (Gra/Pd nanocomposite) was synthesized by simultaneous chemical reduction of graphene oxide and palladium salt in a single step. The negatively charged graphene oxide (GO) facilitates uniform distribution of Pd 2+ ions onto its surface. The subsequent reduction by hydrazine hydrate provides well dispersed Pd nanoparticles decorated graphene. Different amount of Pd nanoparticles on graphene was synthesized by changing the volume to weight ratio of GO to PdCl 2 . X-ray diffraction studies showed FCC lattice of Pd with predominant (1 1 1) plane. SEM and TEM studies revealed that thin graphene nanosheets are decorated by Pd nanoparticles. Raman spectroscopic studies revealed the presence of graphene nanosheets. The electro-catalytic activity of Gra/Pd nanocomposites toward methanol and ethanol oxidation in alkaline medium was evaluated by cyclic voltammetric studies. 1:1 Gra/Pd nanocomposite exhibited good electro-catalytic activity and efficient electron transfer. The kinetics of electron transfer was studied using chronoamperometry. Improved electro-catalytic activity of 1:1 Gra/Pd nanocomposite toward alcohol oxidation makes it as a potential anode for the alcohol fuel cells

  16. Chromatographic enrichment of isotopes in hydrogen and water samples on palladium

    International Nuclear Information System (INIS)

    Andreev, B.M.; Polevoi, A.S.; Perevezentsev, A.N.

    1987-01-01

    Data on the isotopic enrichment of hydrogen and water samples by chromatography on palladium have been analyzed. Experimental data on the effect of temperature, hydrogen flow, volume of the enriched fraction, and length of the chromatographic column on the degree of separation attainable in the column have been obtained. It has been shown that the maximum separation achievable (regardless of the type of the isotope mixture) at 273 K falls with increase of hydrogen flow and volume of the enriched gas fraction recoverable from the column. A separation degree of ∼ 1040 has been achieved for a mixture of protium and deuterium in a 10-mm wide and 0.6-m long chromatographic column packed with palladium black with a grain size of 0.2-0.5 mm at 273 K and a specific hydrogen flow of 1.22 mole/m 2 x sec. For a protium-tritium mixture a separation degree of ∼ 90 has been reached in a similar column at 273 K and a specific hydrogen flow of 0.4 mole/m 2 x sec

  17. Fabrication of palladium nanoparticles immobilized on an amine-functionalized ceramic membrane support using a nanoparticulate colloidal impregnation method with enhanced catalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Du, Yan; Chen, Rizhi [Nanjing Tech University, Nanjing (China)

    2015-09-15

    An efficient and reusable catalyst was developed by depositing palladium nanoparticles on an amine-functionalized ceramic membrane support using a nanoparticulate colloidal impregnation method. The as-prepared Pdloaded ceramic membrane support was characterized by XRD, SEM, EDS, TEM, XPS, ICP, and its catalytic properties were investigated in the liquid-phase p-nitrophenol hydrogenation. A comparative study was also made with the palladium nanoparticles deposited on an amine-functionalized ceramic membrane support by an impregnation-reduction method. The palladium nanoparticles could be homogeneously immobilized on the ceramic membrane support surface, and exhibited excellent catalytic performance in the p-nitrophenol hydrogenation. The catalytic activity of the Pdloaded ceramic membrane support prepared by the nanoparticulate colloidal impregnation method increased by 16.6% compared to that of impregnation-reduction method. In the nanoparticulate colloidal impregnation method, palladium nanoparticles were presynthesized, higher loading of Pd(0) could be obtained, resulting in better catalytic activity. The as-prepared Pd-loaded ceramic membrane support could be easily reused for several cycles without appreciable degradation of catalytic activity.

  18. Determination of the Debye-Waller Factor of hydrogen in Palladium and Palladium Silver alloy

    International Nuclear Information System (INIS)

    Khodabakhsh, R.

    1986-01-01

    The mean square amplitude of the vibrating hydrogen in metals can be determined by using coherent elastic neutron scattering experiments, inelastic one-phonon scattering measurements. To determine the D.W.F. Debye-Waller Factor from the coherent elastic scattering measurements, information about the positions of atoms within the unit is required, and vice versa. The main difficulty concerning the determination of the D.W.F. from the inelastic experiment is in elimination of multi-phonon contribution from the measured spectrum. However, the D.W.F. of hydrogen in palladium has been usually determined by the intensity of the quasi-elastic line. An integration of the measured scattering law S(Q,W) at constant Q, over a certain energy window ΔE, results in the quasi-elastic intensity. To obtain an accurate result, this window has to be chosen large enough to comprise most of the quasi-elastic line, but sufficiently small so that the phonon contributions are small. The MARX spectrometer is ideally constructed for this type of measurement where the window is about +-1 Mev for incident neutron wavelength, =4.115 A. Thus, the quasi-elastic scattering method was considered the best method of determining the D.W.F. of hydrogen in palladium using the MARX spectrometer. However, if the acoustic part overlaps with the quasi-elastic part, one has to obtain the D.W.F. by fitting the data to a quasi-elastic model. The work to be reported here is the investigation of variations of the D.W.F. of hydrogen in Pd and PdAgsub(0.085) with temperature and extension of the available data to as high a temperature as possible. Therefore the integrated intensity of incoherent quasi-elastic neutron scattering by proton in polycrystallin Pd/H and PdAgsub(0.085)/H was investigated as a function of the scattering vector Q. A quasi-harmonic D.W.F. behaviour was observed at elevated temperatures. The observed Debye-Waller Factor depends strongly on the form of the amplitude weighted frequency

  19. A Colorimetric Chemodosimeter for Pd(II): A Method for Detecting Residual Palladium in Cross-Coupling Reactions

    Science.gov (United States)

    Houk, Ronald J. T.; Wallace, Karl J.; Hewage, Himali S.; Anslyn, Eric V.

    2008-01-01

    A colorimetric chemodosimeter (SQ1) for the detection of trace palladium salts in cross-coupling reactions mediated by palladium is described. Decolorization of SQ1 is affected by nucleophilic attack of ethanethiol in basic DMSO solutions. Thiol addition is determined to have an equilibrium constant (Keq) of 2.9 × 106 M-1, with a large entropic and modest enthalpic driving force. This unusual result is attributed to solvent effects arising from a strong coordinative interaction between DMSO and the parent squaraine. Palladium detection is achieved through thiol scavenging from the SQ1-ethanethiol complex leading to a color “turn-on” of the parent squaraine. It was found that untreated samples obtained directly from Suzuki couplings showed no response to the assay. However, treatment of the samples with aqueous nitric acid generates a uniform Pd(NO3)2 species, which gives an appropriate response. “Naked-eye” detection of Pd(NO3)2 was estimated to be as low as 0.5 ppm in solution, and instrument-based detection was tested as low as 100 ppb. The average error over the working range of the assay was determined to be 7%. PMID:19122841

  20. Reversible, high molecular weight palladium and platinum coordination polymers based on phosphorus ligands

    NARCIS (Netherlands)

    Paulusse, J.M.J.; Huijbers, J.P.J.; Sijbesma, R.P.

    2005-01-01

    A general strategy for the preparation and characterization of high molecular weight coordination polymers based on bifunctional phosphorus ligands and palladium or platinum dichloride is described. Metal-to-ligand stoichiometry is of key importance for the formation of linear coordination polymers

  1. Reversible, High Molecular Weight Palladium and Platinum Coordination Polymers Based on Phosphorus Ligands

    NARCIS (Netherlands)

    Paulusse, Jos Marie Johannes; Huijbers, Jeroen P.J.; Sijbesma, Rint P.

    2005-01-01

    A general strategy for the preparation and characterization of high molecular weight coordination polymers based on bifunctional phosphorus ligands and palladium or platinum dichloride is described. Metal-to-ligand stoichiometry is of key importance for the formation of linear coordination polymers

  2. Antibiofilm effect enhanced by modification of 1,2,3-triazole and palladium nanoparticles on polysulfone membranes

    KAUST Repository

    Cheng, Hong

    2015-01-01

    Biofouling impedes the performance of membrane bioreactors. In this study, we investigated the antifouling effects of polysulfone membranes that were modified by 1,2,3-triazole and palladium nanoparticles. The membranes to be tested were embedded within a drip flow biofilm reactor, and Pseudomonas aeruginosa PAO1 was inoculated and allowed to establish biofilm on the tested membranes. It was found that 1,2,3-triazole and palladium nanoparticles can inhibit the bacterial growth in aerobic and anaerobic conditions. The decrease in bacterial growth was observed along with a decrease in the amount of total polysaccharide and Pel polysaccharide within the biofilm matrix but not the protein content.

  3. Antibiofilm effect enhanced by modification of 1,2,3-triazole and palladium nanoparticles on polysulfone membranes

    KAUST Repository

    Cheng, Hong

    2015-08-01

    Biofouling impedes the performance of membrane bioreactors. In this study, we investigated the antifouling effects of polysulfone membranes that were modified by 1,2,3-triazole and palladium nanoparticles. The membranes to be tested were embedded within a drip flow biofilm reactor, and Pseudomonas aeruginosa PAO1 was inoculated and allowed to establish biofilm on the tested membranes. It was found that 1,2,3-triazole and palladium nanoparticles can inhibit the bacterial growth in aerobic and anaerobic conditions. The decrease in bacterial growth was observed along with a decrease in the amount of total polysaccharide and Pel polysaccharide within the biofilm matrix but not the protein content.

  4. Efficiency of Al2O3 supported palladium sorbents in the process of hydrogen isotope exchange

    International Nuclear Information System (INIS)

    Andreev, B.M.; Perevezentsev, A.N.; Yasenkov, V.I.

    1981-01-01

    It is found that in the hydrogen-palladium system while applying the metal to aluminium oxide a considerable increase of the heterogeneous hydrogen isotopic exchange rate is observed due to the increase of its specific surface at 167-298 K temperatures and 350-500 Torr hydrogen pressures. It is shown that in the process of thermal treatment of the supported palladium sorbent resulting in reconstruction of the carrier porous structure, as well as in increasing the metal crystal size, the change of the stage, limiting the isotopic exchange process, occurs. The values of the rate and energy of activation of the hydrogen isotopic exchange are presented [ru

  5. Interaction of ethylene with palladium clusters supported on oxidized tungsten foil

    Czech Academy of Sciences Publication Activity Database

    Jirka, Ivan; Plšek, Jan; Vondráček, Martin; Šutara, F.; Matolin, V.; Cháb, Vladimír; Prince, K. C.

    2007-01-01

    Roč. 601, č. 14 (2007), s. 3114-3124 ISSN 0039-6028 R&D Projects: GA ČR(CZ) GA202/05/0244 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z10100521 Keywords : synchrotron radiation photoelectron spectroscopy * thermal desorption spectroscopy * chemisorption * palladium Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.855, year: 2007

  6. Assembling strategy to synthesize palladium modified kaolin nanocomposites with different morphologies

    OpenAIRE

    Li, Xiaoyu; Ouyang, Jing; Zhou, Yonghua; Yang, Huaming

    2015-01-01

    Nanocomposites of aluminosilicate minerals, kaolins (kaolinite and halloysite) with natural different morphologies assembling with palladium (Pd) nanoparticles have been successfully synthesized through strong electrostatic adsorption and chemical bonding after surface modification with 3-aminopropyl triethoxysilane (APTES). Meanwhile, the influence of different morphologies supports on catalytic hydrogenation properties was explored. The surface concentration of amino groups on the kaolins w...

  7. Electrochemical behavior of ruthenium (III), rhodium (III) and palladium (II) in 1-butyl-3-methylimidazolium chloride ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Jayakumar, M.; Venkatesan, K.A. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Srinivasan, T.G. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)], E-mail: tgs@igcar.gov.in; Vasudeva Rao, P.R. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2009-11-01

    Electrochemical behavior of ruthenium (III), rhodium (III) and palladium (II) in 1-butyl-3-methylimidazolium chloride (bmimCl) and their ternary and binary solutions in bmimCl was studied at various working electrodes at 373 K by cyclic voltammetry and chronoamperometry. Ruthenium (III) chloride forms a stable solution with bmimCl and the cyclic voltammogram of ruthenium (III) in bmimCl recorded at glassy carbon electrode consisted of several redox waves due to the complex nature of ruthenium to exist in several oxidation states. Electrolysis of ruthenium (III) chloride in bmimCl at the cathodic limit of bmimCl (-1.8 V (vs. Pd)) did not result in ruthenium metal deposition. However, it was deposited from bmimPF{sub 6} and bmimNTf{sub 2} room temperature ionic liquids at -0.8 V (vs. Pd). The electrochemical behavior of ruthenium (III) in bmimCl in the presence of palladium (II) and rhodium (III) was studied by cyclic voltammetry. The presence of palladium (II) in bmimCl favors underpotential deposition of ruthenium metal. The nuclear loop at -0.5 V (vs. Pd) was observed in all solutions when palladium (II) co-existed with other two metal ions. Nucleation and growth of the metal on glassy carbon working electrode was investigated by chronoamperometry. The growth and decay of chronocurrents has been found to follow the instantaneous nucleation model with three-dimensional growth of nuclei.

  8. Palladium polypyridyl complexes: synthesis, characterization, DNA interaction and biological activity on Leishmania (L.) mexicana

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Maribel [Instituto Venezolano de Investigaciones Cientificas, Caracas (Venezuela). Centro de Quimica; Betancourt, Adelmo [Universidad de Carabobo, Valencia (Venezuela). Facultad Experimental de Ciencia y Tecnologia. Dept. de Quimica; Hernandez, Clara [Universidad de Carabobo Sede Aragua, Maracay (Venezuela). Facultad de Ciencias de la Salud. Dept. de Ciencias Basicas; Marchan, Edgar [Universidad de Oriente, Cumana (Venezuela). Inst. de Investigaciones en Biomedicina y Ciencias Aplicadas. Nucleo de Sucre

    2008-07-01

    This paper describes the search for new potential chemotherapeutic agents based on transition metal complexes with planar ligands. In this study, palladium polypyridyl complexes were synthesized and characterized by elemental analysis, NMR, UV-VIS and IR spectroscopies. The interaction of the complexes with DNA was also investigated by spectroscopic methods. All metal-to-ligand charge transfer (MLCT) bands of the palladium polypyridyl complexes exhibited hypochromism and red shift in the presence of DNA. The binding constant and viscosity data suggested that the complexes [PdCl{sub 2}(phen)] and [PdCl{sub 2}(phendiamine)] interact with DNA by electrostatic forces. Additionally, these complexes induced an important leishmanistatic effect on L. (L.) mexicana promastigotes at the final concentration of 10 {mu}mol L{sup -1} in 48 h. (author)

  9. Palladium nanoparticles exposure: Evaluation of permeation through damaged and intact human skin.

    Science.gov (United States)

    Larese Filon, Francesca; Crosera, Matteo; Mauro, Marcella; Baracchini, Elena; Bovenzi, Massimo; Montini, Tiziano; Fornasiero, Paolo; Adami, Gianpiero

    2016-07-01

    The intensified use of palladium nanoparticles (PdNPs) in many chemical reactions, jewellery, electronic devices, in car catalytic converters and in biomedical applications lead to a significant increase in palladium exposure. Pd can cause allergic contact dermatitis when in contact with the skin. However, there is still a lack of toxicological data related to nano-structured palladium and information on human cutaneous absorption. In fact, PdNPs, can be absorbed through the skin in higher amounts than bulk Pd because NPs can release more ions. In our study, we evaluated the absorption of PdNPs, with a size of 10.7 ± 2.8 nm, using intact and damaged human skin in Franz cells. 0.60 mg cm(-2) of PdNPs were applied on skin surface for 24 h. Pd concentrations in the receiving solutions at the end of experiments were 0.098 ± 0.067 μg cm(-2) and 1.06 ± 0.44 μg cm(-2) in intact skin and damaged skin, respectively. Pd flux permeation after 24 h was 0.005 ± 0.003 μg cm(-2) h(-1) and 0.057 ± 0.030 μg cm(-2) h(-1) and lag time 4.8 ± 1.7 and 4.2 ± 3.6 h, for intact and damaged skin respectively. This study indicates that Pd can penetrate human skin. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Impacts of the 2015 heat waves on mortality in the Czech Republic-a comparison with previous heat waves

    Czech Academy of Sciences Publication Activity Database

    Urban, A.; Hanzlíková, Hana; Kyselý, J.; Plavcová, E.

    2017-01-01

    Roč. 14, č. 12 (2017), č. článku 1562. ISSN 1660-4601 Institutional support: RVO:67985530 Keywords : heat-related mortality * heat-wave * excess heat factor * Central Europe Subject RIV: DG - Athmosphere Sciences, Meteorology OBOR OECD: Meteorology and atmospheric sciences Impact factor: 2.101, year: 2016

  11. Lenr and "cold Fusion" Excess Heat:. Their Relation to Other Anomalous Microphysical Energy Experiments and Emerging New Energy Technologies

    Science.gov (United States)

    Mallove, Eugene F.

    2005-12-01

    During the past 15 years, indisputable experimental evidence has built up for substantial excess heat (far beyond ordinary chemical energy) and low-energy nuclear reaction phenomena in specialized heavy hydrogen and ordinary hydrogen-containing systems.1 The primary theorists in the field that is properly designated Cold Fusion/LENR have generally assumed that the excess heat phenomena is commensurate with nuclear ash (such as helium), whether already identified or presumed to be present but not yet found. That was an excellent initial hypothesis. However, the commensurate nuclear ash hypothesis has not been proved, and appears to be approximately correct in only a few experiments. During this same period, compelling evidence although not as broadly verified as data from cold fusion/LENR has also emerged for other microphysical sources of energy that were previously unexpected by accepted physics. The exemplar of this has been the "hydrino" physics work of Dr. Randall Mills and his colleagues at Black-Light Power Corporation, which was a radical outgrowth from the cold fusion field that emerged publicly in May 1991.2 Even more far-reaching is the work in vacuum energy extraction pioneered by Dr. Paulo and Alexandra Correa, which first became public in 1996.3 This vacuum energy experimentation began in the early 1980s and has been reduced to prototype technological devices, such as the patented PAGDTM (pulsed abnormal glow discharge) electric power generator, as well as many published experiments that can be performed in table-top fashion to verify the Correa Aetherometry (non-luminiferous or non-electromagnetic aether measurement science).4 In an era when mainstream science and its media is all agog about dark matter and dark energy composing the vast bulk of the universe, there is a great need to reconcile, if possible, the significant bodies of evidence from these three major experimental and theoretical streams: cold fusion/LENR, hydrino physics, and

  12. Oxidative addition of aryl chlorides to monoligated palladium(0): A DFT-SCRF study

    DEFF Research Database (Denmark)

    Ahlquist, Mårten Sten Gösta; Norrby, Per-Ola

    2007-01-01

    Oxidative addition of aryl chlorides to palladium has been investigated by hybrid density functional theory methods (B3LYP), including a continuum model describing the solvent implicitly. A series of para-substituted aryl chlorides were studied to see the influence of electronic effects...

  13. Palladium-Catalysed Direct Cross-Coupling of Organolithium Reagents with Aryl and Vinyl Triflates

    NARCIS (Netherlands)

    Vila, Carlos; Hornillos, Valentin; Giannerini, Massimo; Fananas-Mastral, Martin; Feringa, Bernard L.

    2014-01-01

    Carbon-Carbon Bond Formation Carbon-carbon bond formation by the cross-coupling of highly reactive organolithium reagents is a major challenge. Recently, it was demonstrated that palladium catalysts are able to couple organic halides with various organolithium species under mild conditions in a

  14. Density functional study on the mechanism for the highly active palladium monolayer supported on titanium carbide for the oxygen reduction reaction

    International Nuclear Information System (INIS)

    Mao, Jianjun; Zhang, Yanxing; Chu, Xingli; Li, Shasha; Yang, Zongxian

    2016-01-01

    The adsorption, diffusion, and dissociation of O 2 on the palladium monolayer supported on TiC(001) surface, MLPd/TiC(001), are investigated using ab initio density functional theory calculations. Strong adhesion of palladium monolayer to the TiC(001) support, accompanied by a modification of electronic structure of the supported palladium, is evidenced. Compared with Pt(111) surface, the MLPd/TiC(001) can enhance the adsorption of O 2 , leading to comparable dissociation barrier and a smaller diffusion barrier of O 2 . Whilst the adsorption strength of atomic O (the dissociation product of O 2 ) on MLPd/TiC(001) is similar to that on the Pt(111) surface, possessing high mobility, our theoretical results indicate that MLPd/TiC(001) may serve as a good catalyst for the oxygen reduction reaction.

  15. Synthesis and characterization of palladium-cobalt alloy for new medical micro-devices

    Science.gov (United States)

    Kafrouni, Lina

    According to Canadian Cancer Statistics, it is estimated that 196,900 Canadians will develop cancer and 78,000 will die of cancer in 2015. Given that tumor cells are more sensitive to a temperature increase than healthy ones, this property can be used in vivo to destroy the cancerous cells by elevation of body temperature, otherwise known as hyperthermia. Magnetic hyperthermia is a promising technique for cancer treatment because of ease in targeting the cancerous cells using magnetic nanoparticles (MNPs) and hence having fewer side effects than chemotherapy and radiotherapy. Despite the use of magnetic hyperthermia to treat cancer for thousands of years, the challenge of only heating malignant cells remains daunting. Thus, oncologists often use the heat treatment in combination with radiotherapy or chemotherapy or both. The combined approach results in eliminating many cancer cells in addition to making the resistant cancer cells more vulnerable to other treatments. To use stand-alone magnetic hyperthermia therapy, difficulties in surface modification of magnetic particles for selective uptake by cancerous cells and stability as well as magnetic properties for high heating capacity (> 1000 W/g) must be overcome. The ultimate objective of this thesis is to synthesize an excellent candidate for a powerful magnetic hyperthermia. Due to rapid advances in nanotechnology, a synthesis method of nanoparticles (NPs) with the ability to rigorously control the structure and morphology, such as size, shape and crystallinity, is needed. Electrodeposition is a versatile method for the synthesis of metal NPs directly and selectively onto conductive substrates, simply by regulating applied current or voltage. Furthermore, the particles size and the shape are easily controllable. Besides, studies have shown that the electrodeposition technique is of great utility in the fabrication of nanocrystalline palladium-cobalt (PdCo) alloys. The primary goal of this project is to synthesize

  16. Development of chiral terminal-alkene-phosphine hybrid ligands for palladium-catalyzed asymmetric allylic substitutions.

    Science.gov (United States)

    Liu, Zhaoqun; Du, Haifeng

    2010-07-02

    A variety of novel chiral terminal-alkene-phosphine hybrid ligands were successfully developed from diethyl L-tartrate for palladium-catalyzed asymmetric allylic alkylations, etherifications, and amination to give the desired products in excellent yields and ee's.

  17. Impacts of the 2015 Heat Waves on Mortality in the Czech Republic—A Comparison with Previous Heat Waves

    Czech Academy of Sciences Publication Activity Database

    Urban, A.; Hanzlíková, H.; Kyselý, Jan; Plavcová, E.

    2017-01-01

    Roč. 14, č. 12 (2017), č. článku 1452. ISSN 1660-4601 Institutional support: RVO:86652079 Keywords : heat-related mortality * heat-wave * excess heat factor * Central Europe Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 2.101, year: 2016

  18. Palladium catalyzed selective distal C-H olefination of biaryl systems.

    Science.gov (United States)

    Maity, Soham; Hoque, Ehtasimul; Dhawa, Uttam; Maiti, Debabrata

    2016-11-29

    Palladium catalyzed selective distal C-H activation with nitrile based templates has been of significant research interest in recent times. In this report, we disclose the distal C-H olefination of biphenyl systems with high regio- and stereo-selectivity and useful synthetic yields. The utility of this method has been demonstrated through its wide olefin scope, its operation at the gram scale and the easy removal/recovery of the directing group.

  19. Application of Colloidal Palladium Nanoparticles for Labeling in Electron Microscopy

    Czech Academy of Sciences Publication Activity Database

    Vancová, Marie; Šlouf, Miroslav; Langhans, Jan; Pavlová, Eva; Nebesářová, Jana

    2011-01-01

    Roč. 17, č. 5 (2011), s. 810-816 ISSN 1431-9276 R&D Projects: GA AV ČR KAN200520704; GA AV ČR KJB600960906; GA ČR GAP205/10/0348 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z40500505 Keywords : electron microscopy * colloidal palladium * nanoparticles * labeling * salivary glands * Ixodes ricinus Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.007, year: 2011

  20. p-chloro- and p-bromo-benzoylacetoneoxime as the spectrophotometric reagents for palladium and ruthenium(III)

    International Nuclear Information System (INIS)

    Yeole, V.V.; Langade, A.D.; Shinde, V.M.

    1980-01-01

    A procedure is described for the extractive spectrophotometric determination of palladium or ruthenium(III) using p-chloro or p-bromobenzoylacetoneoxime as the reagent. The yellow palladium complexes which are extracted into chloroform from an aqueous solution of pH 3.5, absorb as 400 nm and conform to Beer's law in the range of 10 to 100 μg of Pd/10 ml of organic phase. The orange-red ruthenium complexes which are extracted into ethylacetate from an aqueous solution of pH 5.0, absorbs at 475 nm and conforms to Beer's law in the range of 20 to 200 μg of Ru/10 ml of organic phase. The molar absorptivities, Sandell's sensitivities and instability constants are reported. (author)

  1. A simple method to deposit palladium doped SnO2 thin films using plasma enhanced chemical vapor deposition technique

    International Nuclear Information System (INIS)

    Kim, Young Soon; Wahab, Rizwan; Shin, Hyung-Shik; Ansari, S. G.; Ansari, Z. A.

    2010-01-01

    This work presents a simple method to deposit palladium doped tin oxide (SnO 2 ) thin films using modified plasma enhanced chemical vapor deposition as a function of deposition temperature at a radio frequency plasma power of 150 W. Stannic chloride (SnCl 4 ) was used as precursor and oxygen (O 2 , 100 SCCM) (SCCM denotes cubic centimeter per minute at STP) as reactant gas. Palladium hexafluroacetyleacetonate (Pd(C 5 HF 6 O 2 ) 2 ) was used as a precursor for palladium. Fine granular morphology was observed with tetragonal rutile structure. A peak related to Pd 2 Sn is observed, whose intensity increases slightly with deposition temperature. Electrical resistivity value decreased from 8.6 to 0.9 mΩ cm as a function of deposition temperature from 400 to 600 deg. C. Photoelectron peaks related to Sn 3d, Sn 3p3, Sn 4d, O 1s, and C 1s were detected with varying intensities as a function of deposition temperature.

  2. Alternative products to carbazoles in the oxidation of diphenylamines with palladium (II) acetate

    OpenAIRE

    Raposo, M. Manuela M.; Campos, Ana M. F. Oliveira; Shannon, Patrick V. R.

    1997-01-01

    Although simple diphenylamines are conveniently oxidised with Palladium (II) acetate to give carbazoles, for more complex examples, carbazoles are minor products amongst many. CRUP (Portugal). British Council - Treaty of Windsor Programme. Junta Nacional de Investigação Científica e Tecnológica.

  3. Memory effects in palladium-catalyzed allylic Alkylations of 2-cyclohexen-1-yl acetate

    DEFF Research Database (Denmark)

    Svensen, Nina; Fristrup, Peter; Tanner, David Ackland

    2007-01-01

    The objective of this work was to characterize the enantiospecificity of the allylic alkylation of enantioenriched 2-cyclohexen-1-yl acetate with the enolate ion of dimethyl malonate catalyzed by unsymmetrical palladium catalysts. The precatalysts employed were (eta(3)-allyl)PdLCl, where L...

  4. Atomic absorption photometry of excess Zn in ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Lott, K.; Shinkarenko, S.; Tuern, L. [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Kirsanova, T.; Grebennik, A.; Vishnjakov, A. [Department of Physical Chemistry, D. Mendelejev University of Chemical Technology of Russia, Miusskaya Sq. 9, 125047 Moscow (Russian Federation)

    2005-02-01

    Zn excess in ZnO is built up automatically at high temperatures. Excess Zn in hydrothermally grown ZnO single crystals were investigated by the atomic absorption photometry (AAP) method. To determine the excess zinc in ZnO samples, the AAP of zinc vapour was used in the conditions of solid-vapour equilibrium. Zn AAP allowed to eliminate excess Zn connected differentially in ZnO samples. To fix Zn non-stoichiometry, all the ZnO samples tested were previously heat treated at temperature interval from 850 to 900 C and at fixed Zn vapour pressures from 0.1 to 0.9 of saturated zinc vapour pressure at given treatment temperature. The analysis of temperature dependence of zinc vapour pressure indicated that the impurity metals take active role in the determination of non-stoichiometric zinc. The impurities Mn, Fe, Co, Ni and Cu form oxides which will reduce during annealing in Zn vapor up to metals form. During AAP measurement in optical cuvette, these metals react with ZnO and give additional Zn vapor pressure. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Fabrication of Nitrogen-Doped Mesoporous-Carbon-Coated Palladium Nanoparticles: An Intriguing Electrocatalyst for Methanol and Formic Acid Oxidation.

    Science.gov (United States)

    Ray, Chaiti; Dutta, Soumen; Sahoo, Ramkrishna; Roy, Anindita; Negishi, Yuichi; Pal, Tarasankar

    2016-05-20

    Inspired by the attractive catalytic properties of palladium and the inert nature of carbon supports in catalysis, a concise and simple methodology for in situ nitrogen-doped mesoporous-carbon-supported palladium nanoparticles (Pd/N-C) has been developed by carbonizing a palladium dimethylglyoximate complex. The as-synthesized Pd/N-C has been exfoliated as a fuel cell catalyst by studying the electro-oxidation of methanol and formic acid. The material synthesized at 400 °C,namely, Pd/N-C-400,exhibitssuperior mass activity and stability among catalysts synthesized under different carbonization temperaturesbetween300 and 500 °C. The unique 1D porous structure in Pd/N-C-400 helps better electron transport at the electrode surface, which eventually leads to about five times better catalytic activity and about two times higher stability than that of commercial Pd/C. Thus, our designed sacrificial metal-organic templatedirected pathway becomes a promising technique for Pd/N-C synthesis with superior catalytic performances. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. The biosynthesis of palladium nanoparticles by antioxidants in Gardenia jasminoides Ellis: long lifetime nanocatalysts for p-nitrotoluene hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Jia Lishan; Zhang Qian; Li Qingbiao; Song Hao, E-mail: jials@xmu.edu.c [Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Key Laboratory for Chemistry and Biochemical Engineering, Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen 361005 (China)

    2009-09-23

    Gardenia jasminoides Ellis' water crude extract was used for the bioreduction of palladium chloride in this paper. The UV-vis spectrum, x-ray diffraction spectrum measurement, the Fourier transform infrared spectroscopy and TEM technique confirmed the formation of palladium nanoparticles and identified antioxidants including geniposide, chlorogenic acid, crocins and crocetin were reducing and stabilizing agents for synthesizing palladium nanoparticles in water crude extract. The particle size and dispersity were temperature-dependent. The particle sizes ranged from 3 to 5 nm and revealed the best dispersity at 70 {sup 0}C. Catalytic performance of the biosynthetic Pd nanoparticles with good dispersity was investigated by hydrogenation of p-nitrotoluene. The catalysts showed a conversion of 100% under conditions of 5 MPa, 150 {sup 0}C for 2 h. The selectivity of p-methyl-cyclohexylamine achieved 26.3%. The catalyst was recycled five times with no agglomeration and maintained activity, which was attributed to the appropriate protection of the antioxidants. On the basis of the study, it appears to be a new promising biosynthetic nanocatalyst for the development of an industrial process.

  7. The biosynthesis of palladium nanoparticles by antioxidants in Gardenia jasminoides Ellis: long lifetime nanocatalysts for p-nitrotoluene hydrogenation

    Science.gov (United States)

    Jia, Lishan; Zhang, Qian; Li, Qingbiao; Song, Hao

    2009-09-01

    Gardenia jasminoides Ellis' water crude extract was used for the bioreduction of palladium chloride in this paper. The UV-vis spectrum, x-ray diffraction spectrum measurement, the Fourier transform infrared spectroscopy and TEM technique confirmed the formation of palladium nanoparticles and identified antioxidants including geniposide, chlorogenic acid, crocins and crocetin were reducing and stabilizing agents for synthesizing palladium nanoparticles in water crude extract. The particle size and dispersity were temperature-dependent. The particle sizes ranged from 3 to 5 nm and revealed the best dispersity at 70 °C. Catalytic performance of the biosynthetic Pd nanoparticles with good dispersity was investigated by hydrogenation of p-nitrotoluene. The catalysts showed a conversion of 100% under conditions of 5 MPa, 150 °C for 2 h. The selectivity of p-methyl-cyclohexylamine achieved 26.3%. The catalyst was recycled five times with no agglomeration and maintained activity, which was attributed to the appropriate protection of the antioxidants. On the basis of the study, it appears to be a new promising biosynthetic nanocatalyst for the development of an industrial process.

  8. Immobilized Palladium Nanoparticles on Zirconium Carboxy-Aminophosphonates Nanosheets as an Efficient Recoverable Heterogeneous Catalyst for Suzuki–Miyaura and Heck Coupling

    Directory of Open Access Journals (Sweden)

    Vadym Kozell

    2017-06-01

    Full Text Available Zirconium phosphate glycine diphosphonate nanosheets (ZPGly have been used as support for the preparation of solid palladium nanoparticles, namely Pd@ZPGly. Thanks to the presence of carboxy-aminophosponate groups on the layer surface, ZPGly-based materials were able to stabilize a high amount of palladium (up to 22 wt % also minimizing the amount of metal leached in the final products of representative important cross-coupling processes selected for proving the catalysts’ efficiency. The catalytic systems have been fully characterized and used in low amounts (0.1 mol % in the Suzuki–Miyaura and Heck cross-couplings. Moreover, the protocols were optimized for the use of recoverable azeotropic mixtures (aq. EtOH 96% or aq. CH3CN 84%, respectively and in the flow procedure allowing one to isolate the final pure products, without any purification step, with very low residual palladium content and with a very low waste production.

  9. Liquid-phase pulsed laser ablation synthesis of graphitized carbon-encapsulated palladium core–shell nanospheres for catalytic reduction of nitrobenzene to aniline

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu-jin; Ma, Rory; Reddy, D. Amaranatha; Kim, Tae Kyu, E-mail: tkkim@pusan.ac.kr

    2015-12-01

    Graphical abstract: - Highlights: • Graphitized carbon-encapsulated palladium core–shell nanospheres fabricated by laser ablation. • Physical characterizations of synthesized Pd@C nanospheres. • Assessments of catalytic performance of Pd@C nanospheres for the reduction of nitrobenzene to aniline. • Significant improvement of the catalytic activity due to the graphitized carbon-layered structure and the high specific surface area. - Abstract: Graphitized carbon-encapsulated palladium (Pd) core–shell nanospheres were produced via pulsed laser ablation of a solid Pd foil target submerged in acetonitrile. The microstructural features and optical properties of these nanospheres were characterized via high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible spectroscopy. Microstructural analysis indicated that the core–shell nanostructures consisted of single-crystalline cubic metallic Pd spheres that serve as the core material, over which graphitized carbon was anchored as a heterogeneous shell. The absorbance spectrum of the synthesized nanostructures exhibited a broad (absorption) band at ∼264 nm; this band corresponded to the typical inter-band transition of a metallic system and resulted possibly from the absorbance of the ionic Pd{sup 2+}. The catalytic properties of the Pd and Pd@C core–shell nanostructures were investigated using the reduction of nitrobenzene to aniline by an excess amount of NaBH{sub 4} in an aqueous solution at room temperature, as a model reaction. Owing to the graphitized carbon-layered structure and the high specific surface area, the resulting Pd@C nanostructures exhibited higher conversion efficiencies than their bare Pd counterparts. In fact, the layered structure provided access to the surface of the Pd nanostructures for the hydrogenation reaction, owing to the synergistic effect between graphitized carbon and the nanostructures. Their

  10. Liquid-phase pulsed laser ablation synthesis of graphitized carbon-encapsulated palladium core–shell nanospheres for catalytic reduction of nitrobenzene to aniline

    International Nuclear Information System (INIS)

    Kim, Yu-jin; Ma, Rory; Reddy, D. Amaranatha; Kim, Tae Kyu

    2015-01-01

    Graphical abstract: - Highlights: • Graphitized carbon-encapsulated palladium core–shell nanospheres fabricated by laser ablation. • Physical characterizations of synthesized Pd@C nanospheres. • Assessments of catalytic performance of Pd@C nanospheres for the reduction of nitrobenzene to aniline. • Significant improvement of the catalytic activity due to the graphitized carbon-layered structure and the high specific surface area. - Abstract: Graphitized carbon-encapsulated palladium (Pd) core–shell nanospheres were produced via pulsed laser ablation of a solid Pd foil target submerged in acetonitrile. The microstructural features and optical properties of these nanospheres were characterized via high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible spectroscopy. Microstructural analysis indicated that the core–shell nanostructures consisted of single-crystalline cubic metallic Pd spheres that serve as the core material, over which graphitized carbon was anchored as a heterogeneous shell. The absorbance spectrum of the synthesized nanostructures exhibited a broad (absorption) band at ∼264 nm; this band corresponded to the typical inter-band transition of a metallic system and resulted possibly from the absorbance of the ionic Pd 2+ . The catalytic properties of the Pd and Pd@C core–shell nanostructures were investigated using the reduction of nitrobenzene to aniline by an excess amount of NaBH 4 in an aqueous solution at room temperature, as a model reaction. Owing to the graphitized carbon-layered structure and the high specific surface area, the resulting Pd@C nanostructures exhibited higher conversion efficiencies than their bare Pd counterparts. In fact, the layered structure provided access to the surface of the Pd nanostructures for the hydrogenation reaction, owing to the synergistic effect between graphitized carbon and the nanostructures. Their unique

  11. Polystyrene-Supported Acyclic Diaminocarbene Palladium Complexes in Sonogashira Cross-Coupling: Stability vs. Catalytic Activity

    Directory of Open Access Journals (Sweden)

    Vladimir N. Mikhaylov

    2018-04-01

    Full Text Available Two types of immobilized on the amino-functionalized polystyrene-supported acyclic diaminocarbene palladium complexes (ADC-PdII are investigated under Sonogashira cross-coupling conditions. Depending on substituents in the diaminocarbene fragment immobilized ADC-PdII, systems are found to have different catalytic activity and stability regarding Pd-leaching. PdII-diaminocarbenes possessing protons at both nitrogen atoms smoothly decompose into Pd0-containing species providing a catalytic “cocktail system” with high activity and ability to reuse within nine runs. Polymer-supported palladium (II complex bearing NBn–Ccarbene–NH-moiety exhibits greater stability while noticeably lower activity under Sonogashira cross-coupling. Four molecular ADC-PdII complexes are also synthesized and investigated with the aim of confirming proposed base-promoted pathway of ADC-PdII conversion through carbodiimide into an active Pd0 forms.

  12. Modelling of Temperature Profiles and Transport Scaling in Auxiliary Heated Tokamaks

    DEFF Research Database (Denmark)

    Callen, J.D.; Christiansen, J.P.; Cordey, J.G.

    1987-01-01

    time , the heating effectiveness η, and the energy offset W(0). Considering both the temperature profile responses and the global transport scaling, the constant heat pinch or excess temperature gradient model is found to best characterize the present JET data. Finally, new methods are proposed......The temperature profiles produced by various heating profiles are calculated from local heat transport models. The models take the heat flux to be the sum of heat diffusion and a non-diffusive heat flow, consistent with local measurements of heat transport. Two models are developed analytically...... in detail: (i) a heat pinch or excess temperature gradient model with constant coefficients; and (ii) a non-linear heat diffusion coefficient (χ) model. Both models predict weak (lesssim20%) temperature profile responses to physically relevant changes in the heat deposition profile – primarily because...

  13. The impact of surface composition on Tafel kinetics leading to enhanced electrochemical insertion of hydrogen in palladium

    Science.gov (United States)

    Dmitriyeva, Olga; Hamm, Steven C.; Knies, David L.; Cantwell, Richard; McConnell, Matt

    2018-05-01

    Our previous work experimentally demonstrated the enhancement of electrochemical hydrogen insertion into palladium by modifying the chemical composition of the cathode surface with Pb, Pt and Bi, referred to as surface promoters. The experiment demonstrated that an optimal combination of the surface promoters led to an increase in hydrogen fugacity of more than three orders of magnitude, while maintaining the same current density. This manuscript discusses the application of Density Functional Theory (DFT) to elucidate the thermodynamics and kinetics of observed enhancement of electrochemical hydrogen insertion into palladium. We present theoretical simulations that: (1) establish the elevation of hydrogen's chemical potential on Pb and Bi surfaces to enhance hydrogen insertion, (2) confirm the increase of a Tafel activation barrier that results in a decrease of the reaction rate at the given hydrogen overpotential, and (3) explain why the surface promoter's coverage needs to be non-uniform, namely to allow hydrogen insertion into palladium bulk while simultaneously locking hydrogen below the surface (the corking effect). The discussed DFT-based method can be used for efficient scanning of different material configurations to design a highly effective hydrogen storage system.

  14. Hydrodechlorination of Tetrachloromethane over Palladium Catalysts Supported on Mixed MgF2-MgO Carriers

    Directory of Open Access Journals (Sweden)

    Magdalena Bonarowska

    2016-11-01

    Full Text Available Pd/MgO, Pd/MgF2 and Pd/MgO-MgF2 catalysts were investigated in the reaction of CCl4 hydrodechlorination. All the catalysts deactivated in time on stream, but the degree of deactivation varied from catalyst to catalyst. The MgF2-supported palladium with relatively large metal particles appeared the best catalyst, characterized by good activity and selectivity to C2-C5 hydrocarbons. Investigation of post-reaction catalyst samples allowed to find several details associated with the working state of hydrodechlorination catalysts. The role of support acidity was quite complex. On the one hand, a definite, although not very high Lewis acidity of MgF2 is beneficial for shaping high activity of palladium catalysts. The MgO-MgF2 support characterized by stronger Lewis acidity than MgF2 contributes to very good catalytic activity for a relatively long reaction period (~5 h but subsequent neutralization of stronger acid centers (by coking eliminates them from the catalyst. On the other hand, the role of acidity evolution, which takes place when basic supports (like MgO are chlorided during HdCl reactions, is difficult to assess because different events associated with distribution of chlorided support species, leading to partial or even full blocking of the surface of palladium, which plays the role of active component in HdCl reactions.

  15. Effect of pH on the spontaneous synthesis of palladium nanoparticles on reduced graphene oxide

    International Nuclear Information System (INIS)

    Zhang, Xiaorui; Ooki, Wataru; Kosaka, Yoshinori R.; Okonogi, Akinori; Marzun, Galina; Wagener, Philipp; Barcikowski, Stephan; Kondo, Takahiro; Nakamura, Junji

    2016-01-01

    Highlights: • Palladium metal nanoparticles were spontaneously formed on reduced graphene oxide (rGO) via a redox reaction in H_2O. • The amount of Pd deposited on rGO was affected by pH. • The amount of oxygen-containing functional groups in rGO was increased with the deposition of palladium. • The importance of redox potential in spontaneous deposition was demonstrated by an experiment with Zn, Ni, Pt, Pd, etc.. • The spontaneous redox deposition method is facile, environmentally friendly, and needs no external reducing agents. - Abstract: Palladium (Pd) nanoparticles were spontaneously deposited on reduced graphene oxide (rGO) without any external reducing agents. The prepared Pd/rGO composites were then characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Spontaneous deposition occurred because of a redox reaction between the Pd precursor and rGO, which involved reduction of bivalent Pd to metallic Pd"0 and oxidation of the sp"2 carbon of rGO to oxygen-containing functional groups. The amount of Pd deposited on rGO varied with pH, and this was attributed to electrostatic interactions between the Pd precursor and rGO based on the results of zeta potential measurements. The importance of the redox reaction in the spontaneous deposition was demonstrated in the experiment with Zn, Ni, Cu, Ag, Pt, Pd, and Au.

  16. Effect of pH on the spontaneous synthesis of palladium nanoparticles on reduced graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaorui [Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Ooki, Wataru; Kosaka, Yoshinori R.; Okonogi, Akinori [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Marzun, Galina; Wagener, Philipp; Barcikowski, Stephan [Technical Chemistry I and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitaetsstrasse 7, D-45141 Essen (Germany); NanoEnergieTechnikZentrum (NETZ), University of Duisburg-Essen, Carl-Benz-Strasse 199, D-47057 Duisburg (Germany); Kondo, Takahiro [Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Tsukuba Research Center for Interdisciplinary Materials Science (TIMS) & Center for Integrated Research in Fundamental Science and Engineering (CiRfSE), University of Tsukuba, 1-1-1 Tennodai, 305-8573 (Japan); Nakamura, Junji, E-mail: nakamura@ims.tsukuba.ac.jp [Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Tsukuba Research Center for Interdisciplinary Materials Science (TIMS) & Center for Integrated Research in Fundamental Science and Engineering (CiRfSE), University of Tsukuba, 1-1-1 Tennodai, 305-8573 (Japan)

    2016-12-15

    Highlights: • Palladium metal nanoparticles were spontaneously formed on reduced graphene oxide (rGO) via a redox reaction in H{sub 2}O. • The amount of Pd deposited on rGO was affected by pH. • The amount of oxygen-containing functional groups in rGO was increased with the deposition of palladium. • The importance of redox potential in spontaneous deposition was demonstrated by an experiment with Zn, Ni, Pt, Pd, etc.. • The spontaneous redox deposition method is facile, environmentally friendly, and needs no external reducing agents. - Abstract: Palladium (Pd) nanoparticles were spontaneously deposited on reduced graphene oxide (rGO) without any external reducing agents. The prepared Pd/rGO composites were then characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Spontaneous deposition occurred because of a redox reaction between the Pd precursor and rGO, which involved reduction of bivalent Pd to metallic Pd{sup 0} and oxidation of the sp{sup 2} carbon of rGO to oxygen-containing functional groups. The amount of Pd deposited on rGO varied with pH, and this was attributed to electrostatic interactions between the Pd precursor and rGO based on the results of zeta potential measurements. The importance of the redox reaction in the spontaneous deposition was demonstrated in the experiment with Zn, Ni, Cu, Ag, Pt, Pd, and Au.

  17. RAPID AND SENSITIVE DETERMINATION OF PALLADIUM USING HOMOGENEOUS LIQUID-LIQUID MICROEXTRACTION VIA FLOTATION ASSISTANCE FOLLOWED BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    Mohammad Rezaee

    2015-05-01

    Full Text Available A method for the determination of trace amounts of palladium was developed using homogeneous liquid-liquid microextraction via flotation assistance (HLLME-FA followed by graphite furnace atomic absorption spectrometry (GFAAS. Ammonium pyrrolidine dithiocarbamate (APDC was used as a complexing agent. This was applied to determine palladium in three types of water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent extraction. No centrifugation was required in this procedure. The water sample solution was added to the extraction cell which contained an appropriate mixture of extraction and homogeneous solvents. By using air flotation, the organic solvent was collected at the conical part of the designed cell. Parameters affecting extraction efficiency were investigated and optimized. Under the optimum conditions, the calibration graph was linear in the range of 1.0-200 µg L-1 with a limit of detection of 0.3 µg L-1. The performance of the method was evaluated for the extraction and determination of palladium in water samples and satisfactory results were obtained. In order to verify the accuracy of the approach, the standard addition method was applied for the determination of palladium in spiked synthetic samples and satisfactory results were obtained.

  18. Determination of trace level of palladium and platinum content in anticancer drug Imatinib base by ICP-MS

    International Nuclear Information System (INIS)

    Yadav, Ravi; Salunke-Gawali, Sunita

    2013-01-01

    Metal impurities in Pharmaceutical drug substance is of great concern not only because of the intrinsic toxicity of certain contaminants but also due to the opposite effect that the contaminants which may have on drug stability and shelf life. Therefore it is necessary to monitor the organic as well as inorganic impurities throughout the process of manufacturing process at every stage from raw material, intermediate and finished products. An Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) method has been developed for Palladium and Platinum content in the anticancer drug, Imatinib mesylate. Rhodium (Rh) was used as internal standard for determination of Palladium and Platinum content on in Imatinib mesylate. (author)

  19. Copper(II) and palladium(II) complexes with tridentate NSO donor Schiff base ligand: Synthesis, characterization and structures

    Science.gov (United States)

    Kumar, Sujit Baran; Solanki, Ankita; Kundu, Suman

    2017-09-01

    Mononuclear copper(II) complex [CuL2] and palladium(II) complexes [Pd(X)L] where X = benzoate(bz) or salicylate(sal) and HL = 2-(methylthio)phenylimino)methyl)phenol, a Schiff base ligand with NSO coordination sites have been synthesized and characterized by microanalyses, IR, UV-Visible spectra, conductivity measurement and magnetic studies. Crystal structures of all the complexes have been solved by single crystal X-ray diffraction studies and showed that there are two molecules in a unit cell in the [CuL2] complex - one molecule has square planar geometry whereas second molecule has distorted square pyramidal geometry and palladium(II) complexes have distorted square planar geometry.

  20. Excess Molar Volume, Viscosity and Heat Capacity for the Mixture of 1,2-Propanediol-Water at Different Temperatures%1,2-丙二醇水溶液在不同温度下的超额摩尔体积黏度和热容

    Institute of Scientific and Technical Information of China (English)

    杨长生; 马沛生; 唐多强; 靳凤民

    2003-01-01

    Experimental densities, viscosities and heat capacities at different temperatures were presented over the entire mole fraction range for the binary mixture of 1,2-propanediol and water. Density values were used in the determination of excess molar volumes, VE. At the same time, the excess viscosity was investigated. The values of VE and ηE were fitted to the Redlich-Kister equation. Good agreement was observed. The excess volumes are negative over the entire range of composition. They show an U-shaped-concentration dependence and decrease in absolute values with increase of temperature. Values of ηE are negative over the entire range of the composition, and has a trend very similar to that of VE . The analysis shows that at any temperature the specific heat of mixture is a linear function of the composition as x1>20%. All the extended lines intersect at one point. An empirical equation is obtained to calculate the specific heat to mixture at any composition and temperature in the experimental range.

  1. Bulk and Surface Structures of Palladium-Modified Copper-Zinc Oxides ex Hydroxycarbonate Precursors

    NARCIS (Netherlands)

    López Granados, M.; Melián-Cabrera, I.; Fierro, J.L.G.

    2002-01-01

    (Pd)-Cu-Zn ex hydroxycarbonate precursors were prepared and characterized by several bulk and surface techniques. A palladium-free Cu-Zn precursor (CZ) was prepared by coprecipitation. Two Pd-Cu-Zn samples were prepared by coprecipitation (PCZ-CP) and sequential precipitation (PCZ-SP). It is shown

  2. Quantification of the reactions in heat storage systems in the Malm aquifer

    Science.gov (United States)

    Ueckert, Martina; Baumann, Thomas

    2017-04-01

    Combined heat and power plants (CHP) are efficient and environmentally friendly because excess heat produced during power generation is used for heating purposes. While the power demand remains rather constant throughout the year, the heat demand shows seasonal variations. In a worst-case scenario, the heat production in winter is not sufficient, and the power production in summer has to be ramped down because the excess heat cannot be released to the environment. Therefore, storage of excess heat of CHP is highly beneficial from an economic and an ecological point of view. Aquifer thermal energy storage (ATES) is considered as a promising technology for energy storage. In a typical setting, water from an aquifer is produced, heated up by excess heat from the CHP and injected through a second borehole back into the aquifer. The carbonate rocks of the upper Jurrasic in the Molasse Basin seem to be promising sites for aquifer heat storage because of their high transmissivity combined with a typical geological setting with tight caprock. However, reactions in the aquifer cannot be neglected and may become the limiting process of the whole operation. While there have been several studies performed in clastic aquifers and for temperatures below 100°C, the knowledge about high injection temperatures and storage into a carbonatic aquifer matrix is still limited. Within a research project funded by the Bavarian State Ministry for Economic Affairs and the BMW Group, the storage and recuperation of excess heat energy into the Bavarian Malm aquifer with flow rates of 15 L/s and temperatures of up to 110°C was investigated. The addition of {CO_2} was used to prevent precipitations. Data from the field site was backed up by autoclave experiments and used to verify a conceptional hydrogeochemical model with PhreeqC for the heat storage operation. The model allows to parametrize the operation and to predict possible reactions in the aquifer.

  3. Recent palladium membrane reactor development at the tritium systems test assembly

    International Nuclear Information System (INIS)

    Willms, R.S.; Birdsell, S.A.; Wilhelm, R.C.

    1995-01-01

    The palladium membrane reactor (PMR) is proving to be a simple and effective means for recovering hydrogen isotopes from fusion fuel impurities such as methane and water. This device directly combines two techniques which have long been utilized for hydrogen processing, namely catalytic shift reactions and palladium/silver permeators. A proof-of-principle (PMR) has been constructed and tested at the Tritium Systems Test Assembly of Los Alamos National Laboratory. The first tests with this device showed that is was effective for the proposed purpose. Initial work concluded that a nickel catalyst was an appropriate choice for use in a PMR. More detailed testing of the PMR with such a catalyst was performed and reported in other works. It was shown that a nickel catalyst-packed PMR did, indeed, recover hydrogen from water and methane with efficiencies approaching 100% in a single processing pass. These experiments were conducted over an extended period of time and no failure or need for regeneration was encountered. These positive results have prompted further PMR development. Topics addressed include alternate PMR geometries and initial testing of the PMR with tritium. These are the subjects of this paper

  4. Sulphur poisoning of palladium catalysts used for methane combustion: Effect of the support

    International Nuclear Information System (INIS)

    Escandon, Lara S.; Ordonez, Salvador; Vega, Aurelio; Diez, Fernando V.

    2008-01-01

    Four different supported palladium catalysts (using alumina, silica, zirconia and titania as supports), prepared by incipient wetness impregnation, were tested as catalysts for methane oxidation in presence of sulphur dioxide. The catalyst supported on zirconia showed the best performance, whereas the silica-supported one showed the fastest deactivation. Temperature-programmed desorption experiments of the poisoned catalysts suggest that SO 2 adsorption capacity of the support plays a key role in the catalyst poisoning. In order to study the effect of promoters, expected to improve the thermal stability and thioresistance of the catalyst, commercial zirconia modified by yttrium and lantane was tested as supports. It was found that the presence of these promoters does not improve the performance of the zirconia-supported catalyst. A deactivation model - considering two different active sites (fresh and poisoning), pseudo-first order dependence on methane concentration and poisoning rate depending on sulphur concentration and fraction of non-poisoned palladium - was used for modelling the deactivation behaviour

  5. Synthesis of palladium-doped silica nanofibers by sol-gel reaction and electrospinning process

    Energy Technology Data Exchange (ETDEWEB)

    San, Thiam Hui; Daud, Wan Ramli Wan; Kadhum, Abdul Amir Hassan; Mohamad, Abu Bakar; Kamarudin, Siti Kartom; Shyuan, Loh Kee; Majlan, Edy Herianto [Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia and Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2012-06-29

    Nanofiber is drawing great attention nowadays with their high surface area per volume and flexibility in surface functionalities that make them favorable as a proton exchange membrane in fuel cell application. In this study, incorporation of palladium nanoparticles in silica nanofibers was prepared by combination of a tetraorthosilane (TEOS) sol-gel reaction with electrospinning process. This method can prevent the nanoparticles from aggregation by direct mixing of palladium nanoparticles in silica sol. The as-produced electrospun fibers were thermally treated to remove poly(vinyl pyrrolidone) (PVP) and condensation of silanol in silica framework. PVP is chosen as fiber shaping agent because of its insulting and capping properties for various metal nanoparticles. Scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the silica fibers and Pd nanoparticles on the fibers. Spun fibers with average diameter ranged from 100nm to 400nm were obtained at optimum operating condition and distribution of Pd nanoparticles on silica fibers was investigated.

  6. Palladium-Catalyzed Carbenylative Cross-Coupling and Carbenylative Amination Utilizing Vinylcarbenes

    OpenAIRE

    Agee, Christopher

    2017-01-01

    This work focuses on the use of N-tosylhydrazones derived from α,β-unsaturated aldehydes – precursors to vinylcarbene ligands – in palladium-catalyzed carbenylative cross-coupling and carbenylative amination reactions. These carbenylative reactions were used to form η3-allylpalladium intermediates that generate stereogenic centers at the carbene center. An initial acyclic model system was used to intercept a well-known prochiral 1,3-diphenylallyl intermediate to probe the feasibility of enant...

  7. Continuous flow hydrogenation using polysilane-supported palladium/alumina hybrid catalysts

    Directory of Open Access Journals (Sweden)

    Shū Kobayashi

    2011-05-01

    Full Text Available Continuous flow systems for hydrogenation using polysilane-supported palladium/alumina (Pd/(PSi–Al2O3 hybrid catalysts were developed. Our original Pd/(PSi–Al2O3 catalysts were used successfully in these systems and the hydrogenation of unsaturated C–C bonds and a nitro group, deprotection of a carbobenzyloxy (Cbz group, and a dehalogenation reaction proceeded smoothly. The catalyst retained high activity for at least 8 h under neat conditions.

  8. The Excess Heat Factor: A Metric for Heatwave Intensity and Its Use in Classifying Heatwave Severity

    Directory of Open Access Journals (Sweden)

    John R. Nairn

    2014-12-01

    Full Text Available Heatwaves represent a significant natural hazard in Australia, arguably more hazardous to human life than bushfires, tropical cyclones and floods. In the 2008/2009 summer, for example, many more lives were lost to heatwaves than to that summer’s bushfires which were among the worst in the history of the Australian nation. For many years, these other forms of natural disaster have received much greater public attention than heatwaves, although there are some signs of change. We propose a new index, called the excess heat factor (EHF for use in Australian heatwave monitoring and forecasting. The index is based on a three-day-averaged daily mean temperature (DMT, and is intended to capture heatwave intensity as it applies to human health outcomes, although its usefulness is likely to be much broader and with potential for international applicability. The index is described and placed in a climatological context in order to derive heatwave severity. Heatwave severity, as characterised by the climatological distribution of heatwave intensity, has been used to normalise the climatological variation in heatwave intensity range across Australia. This methodology was used to introduce a pilot national heatwave forecasting service for Australia during the 2013/2014 summer. Some results on the performance of the service are presented.

  9. Auxiliary Heat Exchanger Flow Distribution Test

    International Nuclear Information System (INIS)

    Kaufman, J.S.; Bressler, M.M.

    1983-01-01

    The Auxiliary Heat Exchanger Flow Distribution Test was the first part of a test program to develop a water-cooled (tube-side), compact heat exchanger for removing heat from the circulating gas in a high-temperature gas-cooled reactor (HTGR). Measurements of velocity and pressure were made with various shell side inlet and outlet configurations. A flow configuration was developed which provides acceptable velocity distribution throughout the heat exchanger without adding excessive pressure drop

  10. An investigation of excess noise in transition-edge sensors on a solid silicon substrate

    International Nuclear Information System (INIS)

    Crowder, S.G.; Lindeman, M.A.; Anderson, M.B.; Bandler, S.R.; Bilgri, N.; Bruijn, M.P.; Chervenak, J.; Figueroa-Feliciano, E.; Finkbeiner, F.; Germeau, A.; Hoevers, H.F.C.; Iyomoto, N.; Kelly, R.; Kilbourne, C.A.; Lai, T.; Man, J.; McCammon, D.; Nelms, K.L.; Porter, F.S.; Rocks, L.; Saab, T.; Sadleir, J.; Vidugiris, G.

    2006-01-01

    Transition-edge sensors (TESs) exhibit two major types of excess noise above the expected and unavoidable thermodynamic fluctuation noise (TFN) to the heat sink and Johnson noise. High-resistance TESs such as those made by the Netherlands Institute for Space Research (SRON) show excess noise consistent with internal TFN (ITFN) caused by random energy transport within the TES itself while low resistance TESs show an excess voltage noise of unknown origin seemingly unrelated to temperature fluctuations. Running a high-resistance TES on a high thermal conductivity substrate should suppress ITFN and allow detection of any excess voltage noise. We tested two TESs on a solid silicon substrate fabricated by SRON of a relatively high normal state resistance of ∼200 mΩ. After determining a linear model of the TES response to noise for the devices, we found little excess TFN and little excess voltage noise for bias currents of up to ∼20 μA

  11. Synergistic dual activation catalysis by palladium nanoparticles for epoxide ring opening with phenols.

    Science.gov (United States)

    Seth, Kapileswar; Roy, Sudipta Raha; Pipaliya, Bhavin V; Chakraborti, Asit K

    2013-07-04

    Synergistic dual activation catalysis has been devised for epoxide phenolysis wherein palladium nanoparticles induce electrophilic activation via coordination with the epoxide oxygen followed by nucleophilic activation through anion-π interaction with the aromatic ring of the phenol, and water (reaction medium) also renders assistance through 'epoxide-phenol' dual activation.

  12. A simple elution strategy for biotinylated proteins bound to streptavidin conjugated beads using excess biotin and heat.

    Science.gov (United States)

    Cheah, Joleen S; Yamada, Soichiro

    2017-12-02

    Protein-protein interactions are the molecular basis of cell signaling. Recently, proximity based biotin identification (BioID) has emerged as an alternative approach to traditional co-immunoprecipitation. In this protocol, a mutant biotin ligase promiscuously labels proximal binding partners with biotin, and resulting biotinylated proteins are purified using streptavidin conjugated beads. This approach does not require preservation of protein complexes in vitro, making it an ideal approach to identify transient or weak protein complexes. However, due to the high affinity bond between streptavidin and biotin, elution of biotinylated proteins from streptavidin conjugated beads requires harsh denaturing conditions, which are often incompatible with downstream processing. To effectively release biotinylated proteins bound to streptavidin conjugated beads, we designed a series of experiments to determine optimal binding and elution conditions. Interestingly, the concentrations of SDS and IGEPAL-CA630 during the incubation with streptavidin conjugated beads were the key to effective elution of biotinylated proteins using excess biotin and heating. This protocol provides an alternative method to isolate biotinylated proteins from streptavidin conjugated beads that is suitable for further downstream analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Prediction of nanofluids properties: the density and the heat capacity

    Science.gov (United States)

    Zhelezny, V. P.; Motovoy, I. V.; Ustyuzhanin, E. E.

    2017-11-01

    The results given in this report show that the additives of Al2O3 nanoparticles lead to increase the density and decrease the heat capacity of isopropanol. Based on the experimental data the excess molar volume and the excess molar heat capacity were calculated. The report suggests new method for predicting the molar volume and molar heat capacity of nanofluids. It is established that the values of the excess thermodynamic functions are determined by the properties and the volume of the structurally oriented layers of the base fluid molecules near the surface of nanoparticles. The heat capacity of the structurally oriented layers of the base fluid is less than the heat capacity of the base fluid for given parameters due to the greater regulation of its structure. It is shown that information on the geometric dimensions of the structured layers of the base fluid near nanoparticles can be obtained from data on the nanofluids density and at ambient temperature - by the dynamic light scattering method. For calculations of the nanofluids heat capacity over a wide range of temperatures a new correlation based on the extended scaling is proposed.

  14. HEAT TRANSFER METHOD

    Science.gov (United States)

    Gambill, W.R.; Greene, N.D.

    1960-08-30

    A method is given for increasing burn-out heat fluxes under nucleate boiling conditions in heat exchanger tubes without incurring an increase in pumping power requirements. This increase is achieved by utilizing a spinning flow having a rotational velocity sufficient to produce a centrifugal acceleration of at least 10,000 g at the tube wall. At this acceleration the heat-transfer rate at burn out is nearly twice the rate which can be achieved in a similar tube utilizing axial flow at the same pumping power. At higher accelerations the improvement over axial flow is greater, and heat fluxes in excess of 50 x 10/sup 6/ Btu/hr/sq ft can be achieved.

  15. Experiments on a ceramic electrolysis cell and a palladium diffuser at the tritium systems test assembly

    International Nuclear Information System (INIS)

    Konishi, Satoshi; Yoshida, Hiroshi; Ohno, Hideo; Naruse, Yuji; Coffin, D.O.; Walthers, C.R.; Binning, K.E.

    1985-01-01

    A ceramic electrolysis cell and a palladium diffuser are developed in Japan and is tested with tritium in Tritium Systems Test Assembly (TSTA) of the Los Alamos National Laboratory, in order to confirm the feasibility as possible upgrades for the fuel cleanup system (PCU). The ceramic electrolysis cell made of stabilized zirconia was operated at 630 0 C for an extended period with a mixture of 3% T 2 O in He carrier gas in the circulation system with oxidizing catalyst bed. The palladium diffuser was tested with circulated pure tritium gas at 280 0 C to verify the compatibility of the alloy with tritium, since the 3 He produced in the metal could cause a degradation. The isotopic effects were also measured for both devices

  16. Preparation of fluorinated biaryls through direct palladium-catalyzed coupling of polyfluoroarenes with aryltrifluoroborates

    KAUST Repository

    Fang, Xin

    2013-07-01

    The direct palladium-catalyzed coupling of polyfluoroarenes with aryltrifluoroborates gave the desired products of fluorinated biaryls in good to excellent yields. A diverse set of important functional groups including methoxy, aldehyde, ester, nitro and halide can be well tolerated in the protocol. © 2013 Elsevier B.V. All rights reserved.

  17. Mapping of potential heat sources for heat pumps for district heating in Denmark

    International Nuclear Information System (INIS)

    Lund, Rasmus; Persson, Urban

    2016-01-01

    The ambitious policy in Denmark on having a 100% renewable energy supply in 2050 requires radical changes to the energy systems to avoid an extensive and unsustainable use of biomass resources. Currently, wind power is being expanded and the increasing supply of electricity is slowly pushing the CHP (combined heat and power) plants out of operation, reducing the energy efficiency of the DH (district heating) supply. Here, large heat pumps for district heating is a frequently mentioned solution as a flexible demand for electricity and an energy efficient heat producer. The idea is to make heat pump use a low temperature waste or ambient heat source, but it has so far been very unclear which heat sources are actually available for this purpose. In this study eight categories of heat sources are analysed for the case of Denmark and included in a detailed spatial analysis where the identified heat sources are put in relation to the district heating areas and the corresponding demands. The analysis shows that potential heat sources are present near almost all district heating areas and that sea water most likely will have to play a substantial role as a heat source in future energy systems in Denmark. - Highlights: • The availability of heat sources for heat pumps in Denmark are mapped and quantified. • A novel methodology for assessment of low temperature industrial excess heat is presented. • There are heat sources available for 99% of district heating networks in Denmark. • The concentration of heat sources is generally bigger around bigger cities than smaller. • Ambient temperature heat sources will be more needed in district heating of big cities.

  18. A Facile Synthesis of a Palladium-Doped Polyaniline-Modified Carbon Nanotube Composites for Supercapacitors

    Science.gov (United States)

    Giri, Soumen; Ghosh, Debasis; Malas, Asish; Das, Chapal Kumar

    2013-08-01

    Supercapacitors have evolved as the premier choice of the era for storing huge amounts of charge in the field of energy storage devices, but it is still necessary to enhance their performance to meet the increasing requirements of future systems. This could be achieved either through advancing the interfaces of the material at the nanoscale or by using novel material compositions. We report a high-performance material composition prepared by combining a transition metal (palladium)-doped conductive polymer with multiwalled carbon nanotubes (MWCNTs). MWCNTs/palladium-doped polyaniline (MWCNTs/Pd/PANI) composites and multiwalled carbon nanotube/polyaniline (MWCNTs/PANI) composites (for comparison) were prepared via in situ oxidative polymerization of aniline monomer. The reported composites were characterized by Fourier-transform infrared (FTIR), x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) studies. FESEM and TEM studies indicated the narrow size distribution of the π-conjugated polymer-protected palladium nanoparticles on the surface of the carbon nanotubes. All the electrochemical characterizations were executed using a three-electrode system in 1 M H2SO4 electrolyte. Cyclic voltammetry (CV) analysis was performed to observe the capacitive performance and redox behavior of the composites. The ion transfer behavior and cyclic stability of the composites were investigated by electrochemical impedance spectroscopy (EIS) analysis and cyclic charge-discharge (CCD) testing, respectively. The MWCNTs/Pd/PANI composite was found to exhibit an especially high specific capacitance value of 920 F/g at scan rate of 2 mV/s.

  19. Synthesis, characterization, DFT calculations and antibacterial activity of palladium(II) cyanide complexes with thioamides

    Science.gov (United States)

    Ahmad, Saeed; Nadeem, Shafqat; Anwar, Aneela; Hameed, Abdul; Tirmizi, Syed Ahmed; Zierkiewicz, Wiktor; Abbas, Azhar; Isab, Anvarhusein A.; Alotaibi, Mshari A.

    2017-08-01

    Palladium(II) cyanide complexes of thioamides (or thiones) having the general formula PdL2(CN)2, where L = Thiourea (Tu), Methylthiourea (Metu), N,N‧-Dimethylthiourea (Dmtu), Tetramethylthiourea (Tmtu), 2-Mercaptopyridine (Mpy) and 2-Mercaptopyrimidine (Mpm) were prepared by reacting K2[PdCl4] with potassium cyanide and thioamides in the molar ratio of 1:2:2. The complexes were characterized by elemental analysis, thermal and spectroscopic methods (IR, 1H and 13C NMR). The structures of three of the complexes were predicted by DFT calculations. The appearance of a band around 2100 cm-1 in IR and resonances around 120-130 ppm in the 13C NMR spectra indicated the coordination of cyanide to palladium(II). More than one resonances were observed for CN- carbon atoms in 13C NMR indicating the existence of equilibrium between different species in solution. DFT calculations revealed that in the case of the palladium(II) complex of Tmtu, the ionic dinuclear [Pd(Tmtu)4][Pd(CN)4] form was more stable than the dimer of mononuclear complex [Pd(Tmtu)2(CN)2] by 0.91 kcal mol-1, while for the complexes of Tu or Mpy ligands, the nonionic [Pd(L)2(CN)2] forms were more stable than the corresponding [Pd(L)4][Pd(CN)4] complexes by 1.26 and 6.49 kcal mol-1 for L = Tu and Mpy, respectively. The complexes were screened for antibacterial effects and some of them showed significant activities against both gram positive as well as gram negative bacteria.

  20. Heat index in migrant farmworker housing: implications for rest and recovery from work-related heat stress.

    Science.gov (United States)

    Quandt, Sara A; Wiggins, Melinda F; Chen, Haiying; Bischoff, Werner E; Arcury, Thomas A

    2013-08-01

    Although the health risk to farmworkers of working in hot conditions is recognized, potential for excessive heat exposure in housing affecting rest and recovery has been ignored. We assessed heat index in common and sleeping rooms in 170 North Carolina farmworker camps across a summer and examined associations with time of summer and air conditioning use. We recorded dangerous heat indexes in most rooms, regardless of time or air conditioning. Policies to reduce heat indexes in farmworker housing should be developed.

  1. All electrochemical fabrication of a bilayer membrane composed of nanotubular photocatalyst and palladium toward high-purity hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Hattori, Masashi [Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga 816-8580 (Japan); Noda, Kei, E-mail: nodakei@elec.keio.ac.jp [Department of Electronics and Electrical Engineering, Keio University, Hiyoshi, Yokohama 223-8522 (Japan)

    2015-12-01

    Graphical abstract: - Highlights: • A bilayer membrane composed of TiO{sub 2} nanotube array and palladium was fabricated. • The TiO{sub 2}/Pd bilayer membrane was prepared with an all-electrochemical process. • The membrane consists of pure Pd and anatase TiO{sub 2} nanotubes with no alloy formation. • Photocatalytic H{sub 2} production and concomitant separation were demonstrated. • High-purity H{sub 2} production rate and apparent quantum yield were evaluated. - Abstract: We developed an all-electrochemical technique for fabricating a bilayer structure of a titanium dioxide (TiO{sub 2}) nanotube array (TNA) and a palladium film (TNA/Pd membrane), which works for photocatalytic high-purity hydrogen production. Electroless plating was used for depositing the Pd film on the TNA surface prepared by anodizing a titanium foil. A 3-μm-thick TNA/Pd membrane without any pinholes in a 1.5-cm-diameter area was fabricated by transferring a 1-μm-thick TNA onto an electroless-plated 2-μm-thick Pd film with a mechanical peel-off process. This ultrathin membrane with sufficient mechanical robustness showed photocatalytic H{sub 2} production via methanol reforming under ultraviolet illumination on the TNA side, immediately followed by the purification of the generated H{sub 2} gas through the Pd layer. The hydrogen production rate and the apparent quantum yield for high-purity H{sub 2} production from methanol/water mixture with the TNA/Pd membrane were also examined. This work suggests that palladium electroless plating is more suitable and practical for preparing a well-organized TNA/Pd heterointerface than palladium sputter deposition.

  2. Test of the palladium diffuser in the JAERI Fuel Cleanup System in the Tritium Systems Test Assembly

    International Nuclear Information System (INIS)

    Konishi, Satoshi; Hayashi, Takumi; O-hira, Shigeru

    1993-03-01

    The JAERI Fuel Cleanup System (JFCU) is a major subsystem of the TSTA simulated fusion fuel loop. The palladium diffuser, that accepts simulated plasma exhaust and purifies the hydrogen isotopes mixture for the feed to the Isotope Separation System, was tested with deuterium to investigate the characteristics of the components. Permeation flow rate is a linear function of the difference of the square root of the pressure across the palladium alloy membrane. However at the low pressure region, an impediment on the permeation was observed. It was suspected to be caused by the impurity adsorbed on the surface of the permeated side of the membrane and was reduced by oxidation treatment. (author)

  3. Fission products silver, palladium, and cadmium identification in neutron-irradiated SiC TRISO particles using a Cs-Corrected HRTEM

    Energy Technology Data Exchange (ETDEWEB)

    Rooyen, I.J. van, E-mail: isabella.vanrooyen@inl.gov [Fuel Design and Development Department, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID, 83415-6188 (United States); Olivier, E.J.; Neethling, J.H. [Centre for High Resolution Electron Microscopy, Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

    2016-08-01

    Electron microscopy investigations of selected coated particles from the first advanced gas reactor experiment at Idaho National Laboratory provided important information on fission product distribution and chemical composition in the silicon-carbide (SiC) layer. Silver precipitates were nano-sized, and therefore high-resolution transmission electron microscopy (HRTEM) was used to provide more information at the atomic level. Based on gamma-ray analysis, this particle which was irradiated to an average burnup of 19.38% fissions per initial metal atom, may have released as much as 10% of its available Ag-110 m inventory during irradiation. The HRTEM investigation focused on silver, palladium, and cadmium due to interest in silver transport mechanisms and possible correlation with palladium and silver previously found. Palladium, silver, and cadmium were found to co-exist in some of the SiC grain boundaries and triple junctions. This study confirmed palladium both at inter and intragranular sites. Phosphor was identified in SiC grain boundaries and triple points. - Highlights: • First high resolution electron microscopy fission product nano-structural locations of irradiated TRISO coated particles. • Pd observed inside SiC grains in proximity to planar defects e.g. stacking faults. • Ag co-exists with Pd and Cd only may suggest a Pd-assisted transport mechanism. • First finding of neutron transmutation product P, in SiC layer of TRISO coated particles. No direct link to Ag transport. • No significant Pd corrosion of SiC observed even at this high resolution images.

  4. Natural phosphate-supported palladium: A highly efficient and recyclable catalyst for the suzuki-miyaura coupling under microwave irradiation

    KAUST Repository

    Hassine, Ayoub; Bouhrara, Mohamed; Sebti, Said; Solhy, Abderrahim; Mahfouz, Remi; Luart, Denis; Lene, Christophe; Fihri, Aziz

    2015-01-01

    This report explores Suzuki-Miyaura coupling under microwave irradiation, using a new generation of catalyst that is based on natural phosphate (NP) impregnated by palladium. This catalyst was prepared by the treatment of natural phosphate with bis(benzonitrile)palladium(II) chloride in acetone at room temperature. The catalyst displayed high catalytic activity for the Suzuki-Miyaura coupling of aryl bromides and chlorides with aryl boronic acids in pure water and with the use of microwave irradiation. The low-cost and availability of the solid support, mild reaction conditions, high yields of desired products, recyclability of the catalyst and short reaction times are the notable features of these methods.

  5. Natural phosphate-supported palladium: A highly efficient and recyclable catalyst for the suzuki-miyaura coupling under microwave irradiation

    KAUST Repository

    Hassine, Ayoub

    2015-01-19

    This report explores Suzuki-Miyaura coupling under microwave irradiation, using a new generation of catalyst that is based on natural phosphate (NP) impregnated by palladium. This catalyst was prepared by the treatment of natural phosphate with bis(benzonitrile)palladium(II) chloride in acetone at room temperature. The catalyst displayed high catalytic activity for the Suzuki-Miyaura coupling of aryl bromides and chlorides with aryl boronic acids in pure water and with the use of microwave irradiation. The low-cost and availability of the solid support, mild reaction conditions, high yields of desired products, recyclability of the catalyst and short reaction times are the notable features of these methods.

  6. Transient thermal stress distribution in a circular pipe heated externally with a periodically moving heat source

    International Nuclear Information System (INIS)

    Özışık, Gülşah; Genç, M. Serdar; Yapıcı, Hüseyin

    2012-01-01

    This study presents the effects of periodically moving heat source on a circular steel pipe heated partly from its outer surface under stagnant ambient conditions. While the pipe is heated with this heat source applied on a certain section having a thickness of heat flux, the water flows through it to transfer heat. It is assumed that the flow is a fully-developed laminar flow. The heat source moves along from one end of the outer to the other end with a constant speed and then returns to the first end with the same speed. It is assumed that the heat transfer rate has a constant value, and that the thermo-physical properties of the steel do not change with temperature (elastic analysis). The numerical calculations have been performed individually for a wide range of thermal conductivity of steel and for different thicknesses of heat flux. The moving heat source produces the non-uniform temperature gradient and the non-uniform effective thermal stress, and when it arrives at the ends of the pipe, the temperature and effective thermal stress ratio profiles rise more excessively. The tangential component is more dominant in the effective thermal stress than the radial component. Highlights: ► Moving heat source produces non-uniform temperature gradients and thermal stresses. ► When moving heat source arrives at ends of pipe, temperature gradients rise excessively. ► With increasing of heat flux thickness and thermal conductivity, the temperature gradients reduce. ► Temperature gradients in thermal boundary layers slightly increase. ► Tangential component is more dominant in thermal stress than radial component.

  7. Umbilical Cord Blood-Derived Stem Cells Improve Heat Tolerance and Hypothalamic Damage in Heat Stressed Mice

    Directory of Open Access Journals (Sweden)

    Ling-Shu Tseng

    2014-01-01

    Full Text Available Heatstroke is characterized by excessive hyperthermia associated with systemic inflammatory responses, which leads to multiple organ failure, in which brain disorders predominate. This definition can be almost fulfilled by a mouse model of heatstroke used in the present study. Unanesthetized mice were exposed to whole body heating (41.2°C for 1 hour and then returned to room temperature (26°C for recovery. Immediately after termination of whole body heating, heated mice displayed excessive hyperthermia (body core temperature ~42.5°C. Four hours after termination of heat stress, heated mice displayed (i systemic inflammation; (ii ischemic, hypoxic, and oxidative damage to the hypothalamus; (iii hypothalamo-pituitary-adrenocortical axis impairment (reflected by plasma levels of both adrenocorticotrophic-hormone and corticosterone; (iv decreased fractional survival; and (v thermoregulatory deficits (e.g., they became hypothermia when they were exposed to room temperature. These heatstroke reactions can be significantly attenuated by human umbilical cord blood-derived CD34+ cells therapy. Our data suggest that human umbilical cord blood-derived stem cells therapy may improve outcomes of heatstroke in mice by reducing systemic inflammation as well as hypothalamo-pituitary-adrenocortical axis impairment.

  8. Nanocomposite catalyst with palladium nanoparticles encapsulated in a polymeric acid: A model for tandem environmental catalysis

    KAUST Repository

    Isimjan, Tayirjan T.; He, Quan; Liu, Yong; Zhu, Jesse; Puddephatt, Richard J.; Anderson, Darren Jason

    2013-01-01

    The synthesis and characterization of a novel hybrid nanocomposite catalyst comprised of palladium nanoparticles embedded in polystyrene sulfonic acid (PSSH) and supported on metal oxides is reported. The catalysts are intended for application

  9. Wind power integration using individual heat pumps – Analysis of different heat storage options

    DEFF Research Database (Denmark)

    Hedegaard, Karsten; Mathiesen, Brian Vad; Lund, Henrik

    2012-01-01

    Significant installations of individual heat pumps are expected in future energy systems due to their economic competitiveness. This case study of the Danish energy system in 2020 with 50% wind power shows that individual heat pumps and heat storages can contribute to the integration of wind power....... Heat accumulation tanks and passive heat storage in the construction are investigated as two alternative storage options in terms of their ability to increase wind power utilisation and to provide cost-effective fuel savings. Results show that passive heat storage can enable equivalent to larger...... reductions in excess electricity production and fuel consumption than heat accumulation tanks. Moreover, passive heat storage is found to be significantly more cost-effective than heat accumulation tanks. In terms of reducing fuel consumption of the energy system, the installation of heat pumps is the most...

  10. Superparamagnetic bimetallic iron-palladium nanoalloy: synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, Rabia; Mazhar, Muhammad [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Akhtar, M Javed; Nadeem, M; Siddique, Muhammad [Physics Division, PINSTECH, PO Nilore, Islamabad 44000 (Pakistan); Shah, M Raza [HEJ Research Institute of Chemistry, University of Karachi, Karachi 75270 (Pakistan); Khan, Nawazish A [Material Science Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Mehmood, Mazhar [National Centre for Nanotechnology, PIEAS, Islamabad 45650 (Pakistan); Butt, N M [Pakistan Science Foundation, Islamabad 44000 (Pakistan)], E-mail: mazhar42pk@yahoo.com

    2008-05-07

    Iron-palladium nanoalloy in the particle size range of 15-30 nm is synthesized by the relatively low temperature thermal decomposition of coprecipitated [Fe(Bipy){sub 3}]Cl{sub 2} and [Pd(Bipy){sub 3}]Cl{sub 2} in an inert ambient of dry argon gas. The silvery black Fe-Pd alloy nanoparticles are air-stable and have been characterized by EDX-RF, XRD, AFM, TEM, magnetometry, {sup 57}Fe Moessbauer and impedance spectroscopy. This Fe-Pd nanoalloy is in single phase and contains iron sites having up to 11 nearest-neighboring atoms. It is superparamagnetic in nature with high magnetic susceptibility, low coercivity and hyperfine field.

  11. Palladium nanoparticles on InP for hydrogen detection

    Directory of Open Access Journals (Sweden)

    Zdansky Karel

    2011-01-01

    Full Text Available Abstract Layers of palladium (Pd nanoparticles on indium phosphide (InP were prepared by electrophoretic deposition from the colloid solution of Pd nanoparticles. Layers prepared by an opposite polarity of deposition showed different physical and morphological properties. Particles in solution are separated and, after deposition onto the InP surface, they form small aggregates. The size of the aggregates is dependent on the time of deposition. If the aggregates are small, the layer has no lateral conductance. Forward and reverse I-V characteristics showed a high rectification ratio with a high Schottky barrier height. The response of the structure on the presence of hydrogen was monitored.

  12. Determination of palladium in biological samples applying nuclear analytical techniques

    International Nuclear Information System (INIS)

    Cavalcante, Cassio Q.; Sato, Ivone M.; Salvador, Vera L. R.; Saiki, Mitiko

    2008-01-01

    This study presents Pd determinations in bovine tissue samples containing palladium prepared in the laboratory, and CCQM-P63 automotive catalyst materials of the Proficiency Test, using instrumental thermal and epithermal neutron activation analysis and energy dispersive X-ray fluorescence techniques. Solvent extraction and solid phase extraction procedures were also applied to separate Pd from interfering elements before the irradiation in the nuclear reactor. The results obtained by different techniques were compared against each other to examine sensitivity, precision and accuracy. (author)

  13. Palladium-catalyzed cyclocarbonylation of o-iodoanilines with heterocumulenes: regioselective preparation of 4(3H)-quinazolinone derivatives

    Science.gov (United States)

    Larksarp; Alper

    2000-05-09

    A catalyst system comprising palladium acetate-bidentate phosphine is effective for the cyclocarbonylation of o-iodoanilines with heterocumulenes at 70-100 degrees C for 12-24 h to give the corresponding 4(3H)-quinazolinone derivatives in good yields. Utilizing o-iodoaniline with isocyanates, carbodiimides, and ketenimines for the reaction, 2,4-(1H,3H)-quinazolinediones, 2-amino-4(3H)-quinazolinones and 2-alkyl-4(3H)-quinazolinones were obtained, respectively. The nature of the substrates including the electrophilicity of the carbon center of the carbodiimide, and the stability of the ketenimine, influence the product yields of this reaction. Urea-type intermediates are believed to be generated first in situ from the reaction of o-iodoanilines with heterocumulenes, followed by palladium-catalyzed carbonylation and cyclization to yield the products.

  14. Effects of impurities on hydrogen permeability through palladium alloy membrane at comparatively high pressure and temperature

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi; Konishi, Satoshi; Katsuta, Hiroji; Naruse, Yuji

    1982-02-01

    Palladium alloy membrane method is considered to be a useful technique for fusion reactor fuel purification process. To study the feasibility of this method, the effects of impurities on permeation characteristics of palladium alloy membrane were examined. Experiments were carried out at practical conditions: pressure; 120 - 1200 kPa, temperature; about 700 K. No poisoning effect on hydrogen permeability of commercial Pd-Ag (Au.Ru) alloy was observed for impurities such as NH 3 , CH 4 , CO, CO 2 , O 2 and N 2 , which were mixed with hyper-pure H 2 at low concentration level (10 - 10000 ppm). Deterioration occurred by contamination with oil vapor. However, regeneration of the membrane was easily performed by air baking followed by hydrogen reduction. Chemical reactions in the permeation cell were also examined. (author)

  15. Investigation into periodic process of hydrogen isotope separation by counterflow method in the hydrogen-palladium system

    International Nuclear Information System (INIS)

    Andreev, B.M.; Selivanenko, I.L.; Vedeneev, A.I.; Golubkov, A.N.; Tenyaev, B.N.

    1999-01-01

    The key diagram and results of the investigation into working conditions of the pilot plant for hydrogen isotope separation embodying the concept of continuous counterflow separation in the hydrogen-palladium system are shown. The counterflow of phases in the plant is attained under the motion of palladium solid hydride phase relative to stationary blocks of flow rotation. The column separator is defined as section type one. The plant performs in periodic regime with accumulating vessels for light and heavy components of the separated mixture. Maximum concentration of the separated tritium ranged up to ∼ 96 % in the experiments of the deuterium-tritium separation. Minimum concentration of the residual tritium in the mixture ranged up to ∼ 0.1 %. The plant provides to reprocessing 4.5 moles of the gas a day [ru

  16. Palladium(II)-catalyzed ortho-olefination of arenes applying sulfoxides as remote directing groups.

    Science.gov (United States)

    Wang, Binjie; Shen, Chuang; Yao, Jinzhong; Yin, Hong; Zhang, Yuhong

    2014-01-03

    A novel palladium-catalyzed ortho-C(sp(2))-H olefination protocol has been developed by the use of sulfoxide as the directing group. Importantly, relatively remote coordination can be accessed to achieve the ortho olefination of benzyl, 2-arylethyl, and 3-arylpropenyl sulfoxide substrates, and the olefinated sulfoxide can be easily transformed to other functionalities.

  17. Simultaneous determination of palladium, platinum and rhodium by on-line column enrichment and HPLC with 2,4-dihydroxybenzylidenethiorhodanine as pre-column derivatization reagent

    Directory of Open Access Journals (Sweden)

    Dong Xuechang

    2006-01-01

    Full Text Available A new method for the simultaneous determination of palladium, platinum and rhodium ions as metal-DHBTR chelates was developed. The palladium, platinum and rhodium ions were pre-column derivatized with 2,4-dihydroxybenzylidenethiorhodanine (DHBTR to form colored chelates. The Pd-DHBTR, Pt-DHBTR and Rh-DHBTR chelates can be absorbed onto the front of the enrichment column when they were injected into the injector and sent to the enrichment column with a 0.05 mol L-1 sodium acetate-acetic acid buffer solution (pH 3.5 as mobile phase. After the enrichment had finished, by switching the six ports switching valve, the retained chelates were back-flushed by mobile phase and traveling towards the analytical column. These chelates separation on the analytical column was satisfactory with 62% (v/v acetonitrile (containing 0.05 mol L-1 of pH 3.5 sodium acetate-acetic acid buffer salt and 0.1% (m/v of tritonX-100 as mobile phase. The Limits of detection of palladium, platinum and rhodium are 3.6 ng L-1, 3.2 ng L-1 and 4.5 ng L-1, respectively. This method was applied to the determination of palladium, platinum and rhodium in water, urine and soil samples with good results.

  18. Identification of excess 40Ar by the 40Ar/39Ar age spectrum technique

    International Nuclear Information System (INIS)

    Lanphere, M.A.; Dalrymple, G.B.

    1976-01-01

    40 Ar/ 39 Ar incremental heating experiments on igneous plagioclase, biotite, and pyroxene that contain known amounts of excess 40 Ar indicate that saddle-shaped age spectra are diagnostic of excess 40 Ar in igneous minerals as well as in igneous rocks. The minima in the age spectra approach but do not reach the crystallization age. Neither the age spectrum diagram nor the 40 Ar/ 36 Ar versus 39 Ar/ 36 Ar isochron diagram reliably reveal the crystallization age in such samples. (Auth.)

  19. Neutron measurements in deuterated palladium cathodes subjected to pulsed electrolytic currents

    International Nuclear Information System (INIS)

    Granada, J.R.; Mayer, R.E.; Guido, G.; Florido, P.C.; Patino, N.E.; Gillette, V.H.; Sobehart, L.; Gomez, S.; Larreteguy, A.; Universidad Nacional de Cuyo, San Carlos de Bariloche

    1989-01-01

    We report on neutron measurements performed on electrolytic cells using a high efficiency (22%) detection system in combination with a procedure involving a non-stationary current through the cell's circuit. Under these conditions, neutron production was observed in cells containing LiH dissolved in heavy water with a Palladium cathode. Characteristic patterns showing one or two bumps were obtained in a repeatable fashion, depending on the previous charging history of the cathode. (orig.)

  20. Investigating the nature of palladium chain-walking in the enantioselective redox-relay Heck reaction of alkenyl alcohols.

    Science.gov (United States)

    Hilton, Margaret J; Xu, Li-Ping; Norrby, Per-Ola; Wu, Yun-Dong; Wiest, Olaf; Sigman, Matthew S

    2014-12-19

    The mechanism of the redox-relay Heck reaction was investigated using deuterium-labeled substrates. Results support a pathway through a low energy palladium-alkyl intermediate that immediately precedes product formation, ruling out a tautomerization mechanism. DFT calculations of the relevant transition structures at the M06/LAN2DZ+f/6-31+G* level of theory show that the former pathway is favored by 5.8 kcal/mol. Palladium chain-walking toward the alcohol, following successive β-hydride eliminations and migratory insertions, is also supported in this study. The stereochemistry of deuterium labels is determined, lending support that the catalyst remains bound to the substrate during the relay process and that both cis- and trans-alkenes form from β-hydride elimination.

  1. Effects of polarization-charge shielding in microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Lin, M. S.; Lin, S. M.; Chiang, W. Y.; Barnett, L. R.; Chu, K. R., E-mail: krchu@yahoo.com.tw [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China)

    2015-08-15

    Heating of dielectric objects by radio frequency (RF) and microwaves has long been a method widely employed in scientific research and industrial applications. However, RF and microwave heating are often susceptible to an excessive temperature spread due to uneven energy deposition. The current study elucidates an important physical reason for this difficulty and proposes an effective remedy. Non-spherical samples are placed in an anechoic chamber, where it is irradiated by a traveling microwave wave with 99% intensity uniformity. Polarization charges induced on the samples tend to partially cancel the incident electric field and hence reduce the heating rate. The polarization-charge shielded heating rate is shown to be highly dependent on the sample's shape and its orientation relative to the wave electric field. For samples with a relatively high permittivity, the resultant uneven heating can become a major cause for the excessive temperature spread. It is also demonstrated that a circularly polarized wave, with its rapidly rotating electric field, can effectively even out the heating rate and hence the temperature spread.

  2. Definition of the size of nanoclusters of silver and palladium in carbon fiber

    International Nuclear Information System (INIS)

    Volobuev, V.S.; Bashmakov, I.A.; Lukashevich, S.M.; Tolkacheva, E.A.; Tikhonova, T.F.; Lukashevich, M.G.; Kaputskij, F.N.

    2008-01-01

    Size of palladium and silver nanoclusters is carbon matrix prepared by heart treatment of metal-polymer precursor has been determined by means of XR diffractions study. It was shown that the cluster size increases with increasing annealing temperature from 700 to 900 degree Celsius by factor two. No structuring of carbon matrix was observed under clusters forming. (authors)

  3. Palladium Hydride Promoted Stereoselective Isomerization of Unactivated Di(exo)methylenes to Endocyclic Dienes

    OpenAIRE

    Jung, Michael E.; Lee, Gloria S.; Pham, Hung V.; Houk, K. N.

    2014-01-01

    The exomethylenes of 2,6-disubstituted bicyclo[3.3.1]nonan-9-ones 2 are readily isomerized over a palladium catalyst under an atmosphere of hydrogen to predominantly form the isomer 3 with C 2 symmetry with very little formation of the analogous product with C s symmetry. A hydrogen source is essential to effect the rearrangement.

  4. Synthesis, characterization and thermal properties of palladium(II complexes containing phenyltetrazole. Crystal structure of trans-[C40H64N8 O2PdCl2

    Directory of Open Access Journals (Sweden)

    Gallardo Hugo

    2000-01-01

    Full Text Available The new 5-(n-alkoxyphenyl-2-n-alkyltetrazole (L¹ and alpha,omega-bis-[5-(4-pentoxyphenyl-2-alkanetetrazoles] (L² ligands and their Pd(II complexes have been synthesized. The X-ray diffraction study of the palladium complex with L¹ reveals a mononuclear structure in which the geometry of the Pd(L¹2Cl2 chromophore is planar as required by the inversion center at the palladium atom, where each molecule of phenyltetrazole binds to the metal ion in a monodentate fashion via a Pd-N1 sigma-bond. For the palladium complex with L², a dinuclear structure ([Pd2(L²2Cl4 ] has been proposed on the basis of NMR and IR spectroscopy.

  5. Enhancement in photovoltaic properties of silicon solar cells by surface plasmon effect of palladium nanoparticles

    Science.gov (United States)

    Atyaoui, Malek; Atyaoui, Atef; Khalifa, Marwen; Elyagoubi, Jalel; Dimassi, Wissem; Ezzaouia, Hatem

    2016-04-01

    This work presents the surface Plasmon effect of Palladium nanoparticles (Pd NPs) on the photovoltaic properties of silicon solar cells. Pd NPs were deposited on the p-type silicon base of the n+/p junction using a chemical deposition method in an aqueous solution containing Palladium (II) Nitrate (PdNO3)2 and Ammonium Hydroxide (NH4OH) followed by a thermal treatment at 500 °C under nitrogen atmosphere. Chemical composition and surface morphology of the treated silicon base were examined by energy dispersive X-ray (EDX) spectroscopy, scanning electronic microscopy (SEM) and Atomic Force Microscopy (AFM). The effect of the deposited Pd NPs on the electrical properties was evaluated by the internal quantum efficiency (IQE) and current-voltage (I-V) measurements. The results indicate that the formation of the Pd NPs is accompanied by an enhanced light absorption and improved photovoltaic parameters.

  6. Metallurgical characterization of new palladium-containing cobalt chromium and nickel chromium alloys

    Science.gov (United States)

    Puri, Raghav

    Recently introduced to the market has been an entirely new subclass of casting alloy composition whereby palladium (˜25 wt%) is added to traditional base metal alloys such as CoCr and NiCr. Objectives. The purpose of this study was to evaluate the microstructure and Vickers hardness of two new CoPdCr and one new NiPdCr alloy and compare them to traditional CoCr and NiCr alloys. Methods. The casting alloys investigated were: CoPdCr-A (Noble Crown NF, The Argen Corporation), CoPdCr-I (Callisto CP+, Ivoclar Vivadent), NiPdCr (Noble Crown, Argen), CoCr (Argeloy N.P. Special, Argen), and NiCr (Argeloy N.P. Star, Argen). As-cast cylindrical alloy specimens were mounted in epoxy resin and prepared with standard metallographic procedures, i.e. grinding with successive grades of SiC paper and polishing with alumina suspensions. The alloys were examined with an optical microscope, SEM/EPMA, and XRD to gain insight into their microstructure, composition, and crystal structure. Vickers hardness (VHN) was measured and statistically analyzed by one way ANOVA and Tukey's HSD test (alpha=0.05). Results. Optical microscopy showed a dendritic microstructure for all alloys. The Pd-containing alloys appear to possess a more complex microstructure. SEM/EPMA showed Cr to be rather uniformly distributed in the matrix with palladium tending to be segregated apart from Mo and Ni or Co. Areas of different composition may explain the poor electrochemical results noted in previous studies. XRD suggested the main phase in the Ni-containing solutions was a face centered cubic Ni solid solution, whereas the CoCr exhibited a hexagonal crystal structure that was altered to face centered cubic when Pd was included in the composition. For Vickers hardness, the Co-containing alloys possessed a greater hardness than the Ni-containing alloys. However, the incorporation of Pd in CoCr and NiCr had only a slight effect on microhardness. Conclusion. Overall, the inclusion of palladium increases the

  7. Acoustic emission during hydrogen absorption and desorption in palladium

    International Nuclear Information System (INIS)

    Ramesh, R.; Mukhopadhyay, C.K.; Jayakumar, T.; Baldev Raj

    1996-01-01

    Acoustic emission technique has been used to study charging and discharging of hydrogen in palladium. During charging, breaking of oxide film due to surface activation and saturation of hydrogen absorption have been identified by acoustic emission. In the discharging cycle, the desorption of hydrogen from the specimen leads to high AE activity immediately after initiation of discharging, followed by gradual decrease in the acoustic activity, which reaches a minimum upon completion of the desorption. The potential of the acoustic emission technique for studying the kinetics of hydrogen absorption and desorption in metals has been shown. (author)

  8. Soluble Polymer-supported Synthesis of Indoles via Palladium-mediat -ed Heteroannulation of Terminal Alkynes with o-Iodoanilines

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A soluble polymer-supported synthesis of indoles via palladium-mediated hetero- annulation of terminal alkynes with o-iodoanilines has been described. The protocol provides a useful tool for constructing combinatorial indole libraries.

  9. Thermodynamic excess quantities of ternary Au-Co-Pd melts by computer-aided Knudsen cell mass spectrometry

    International Nuclear Information System (INIS)

    Tomiska, Josef

    2009-01-01

    Computer-aided Knudsen cell mass spectrometry is used for the thermodynamic investigations on ternary Au-Co-Pd melts over the entire range of composition. The 'digital intensity-ratio' (DIR)-method has been applied for the determination of the thermodynamic excess quantities, and the ternary thermodynamically adapted power (TAP) series concept is used for algebraic representation of the thermodynamic mixing behavior. The corresponding TAP parameters as well as the values of the molar excess Gibbs energies G E , of the molar heats of mixing H E , of the molar excess entropies S E , and of the thermodynamic activities at 1800 K are presented.

  10. Complexes of palladium(II with 1-phenyl-1-hydroxymethylene bisphosphoniс acid and their antitumor activity

    Directory of Open Access Journals (Sweden)

    O. M. Kozachkova

    2017-02-01

    Full Text Available Complex formation of K2[PdCl4] with 1-phenyl-1-hydroxymethylene bisphosphonic acid (PhHMBP, H4L has been studied by pH potentiometry, electron and NMR spectroscopy. It was found that in aqueous solution with physiological concentration of chlorine anions (0.15 mol/l KCl, anionic complexes of the equimolar compositions [PdHLCl2]3- (lgβ = 24.51 (0.3 and [PdLCl2]4- (lgβ = 20.74 (0.02 are formed. In the first coordination sphere palladium was surrounded by two oxygen atoms of two phosphonic groups of the bidentately coordinated ligand with closure of six-membered [O, O] ring, and two chlorine anions. The formation of palladium(II equimolar complexes with PhHMBP and bidentate coordination of the ligand to the central metal cation was confirmed by 31P NMR spectroscopy. Cytotoxic activity (IC50 based on metal content of the synthesized Pd(II complexes with PhHMBP against human MG-63 osteosarcoma and MCF-7 mammary tumor cells was compared with cisplatin on in vitro models. It was established that cytotoxic activity of the Pd complexes was lower than that of cisplatin. The acute toxicity (LD50 based on metal content of solutions of Pd(II complexes with PhHMBP was found to be lower compared to cisplatin. It was shown that the use of solutions of palladium(II complexes with PhHMBP inhibited tumor growth in mice with sarcoma 180.

  11. Ab initio study of the structural, magnetic, and electronic properties of copper and silver clusters and their alloys with one palladium atom

    Directory of Open Access Journals (Sweden)

    S. J Hashemifar

    2015-01-01

    Full Text Available In this paper, the structural, magnetic, and electronic properties of two- to nine-atom copper and silver clusters and their alloys with one palladium atom are investigated by using full-potential all-electron density functional computations. After calculating minimized energy of several structural isomers of every nanocluster, it is argued that the small size nanoclusters (up to size of 6, ‎ prefer planar structures, while by increasing size a 2D-3D structural transformation is observed. The structural transformation of pure and copper-palladium clusters occurs in the size of seven and that of silver-palladium cluster in happens at the size of six. The calculated second difference and dissociation energies confirm that the two- and eight- atom pure clusters and three- and seven- atom alloyed clusters are magic clusters. The electronic and magnetic properties of stable isomers are calculated and considered after applying many body based GW correction.

  12. Nickel(II) and palladium(II) triphenylphosphine complexes incorporating tridentate Schiff base ligands: Synthesis, characterization and biocidal activities

    Science.gov (United States)

    Shabbir, Muhammad; Akhter, Zareen; Ashraf, Ahmad Raza; Ismail, Hammad; Habib, Anum; Mirza, Bushra

    2017-12-01

    Nickel(II) and palladium(II) triphenylphosphine complexes incorporating tridentate Schiff bases have been prepared and characterized by elemental analysis as well as by spectroscopic techniques (FTIR & NMR). The synthesized compounds were assessed to check their potential biocidal activity by using different biological assays (brine shrimp cytotoxicity, antimicrobial, antioxidant, antitumor and drug-DNA interaction). Results of brine shrimp cytotoxicity assay showed that ligand molecules are more bioactive than metal complexes with LD50 as low as 12.4 μg/mL. The prominent antitumor activity was shown by nickel complexes while the palladium complexes exhibited moderate activity. The synthesized compounds have shown high propensity for DNA binding either through intercalation or groove binding which represents the mechanism of antitumor effect of these compounds. Additionally, ligand molecules and nickel metal complexes showed significant antioxidant activity with IC50 values as low as 3.1 μg/mL and 18.9 μg/mL respectively while palladium complexes exhibited moderate activity. Moreover, in antimicrobial assays H2L1, Ni(L1)PPh3 and H2L3 showed dual inhibition against bacterial and fungal strains while for the rest of the compounds varying degree of activity was recorded against different strains. Overall comparison of results suggests that the synthesized compounds can be promising candidate for drug formulation and development.

  13. GREEN SYNTHESIS OF SILVER AND PALLADIUM NANOPARTICLES AT ROOM TEMPERATURE USING COFFEE AND TEA EXTRACT

    Science.gov (United States)

    An extremely simple green approach that generates bulk quantities of nanocrystals of noble metals such as silver (Ag) and palladium (Pd) using coffee and tea extract at room temperature is described. The single-pot method uses no surfactant, capping agent, and/or template. The ob...

  14. Phenomenological in-situ TEM gas exposure studies of palladium particles on MgO at room temperature

    Science.gov (United States)

    Heinemann, K.; Poppa, H.; Osaka, T.

    1983-01-01

    It has been found that very small vapor-deposited catalytically active metal particles in the 1-2 nm size range on metal oxide substrates can undergo significant changes when they are exposed to gases such as oxygen or air, or even when allowed to 'anneal' at room temperature (RT) under vacuum conditions. The present investigation is concerned with continued in-situ gas exposures of as-deposited, 1 to 2 nm size palladium particles on MgO to air, oxygen, nitrogen, hydrogen, CO, and water vapor at RT. It is found that the low-pressure exposure to various gases at RT can significantly affect small palladium particles supported on MgO surfaces. Exposure to oxygen for 3 min at 0.0002 m bar produces a considerable amount of coalescence, flattening of the particles, and some distinct crystallographic particle shapes.

  15. Californium Recovery from Palladium Wire

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-08-01

    The recovery of 252Cf from palladium-252Cf cermet wires was investigated to determine the feasibility of implementing it into the cermet wire production operation at Oak Ridge National Laboratory’s Radiochemical Engineering Development Center. The dissolution of Pd wire in 8 M HNO3 and trace amounts of HCl was studied at both ambient and elevated temperatures. These studies showed that it took days to dissolve the wire at ambient temperature and only 2 hours at 60°C. Adjusting the ratio of the volume of solvent to the mass of the wire segment showed little change in the kinetics of dissolution, which ranged from 0.176 mL/mg down to 0.019 mL/mg. A successful chromatographic separation of 153Gd, a surrogate for 252Cf, from Pd was demonstrated using AG 50x8 cation exchange resin with a bed volume of 0.5 mL and an internal diameter of 0.8 cm.

  16. The excess enthalpies of liquid Ge-Pb-Te alloys

    International Nuclear Information System (INIS)

    Blachnik, R.; Binder, J.; Schlieper, A.

    1997-01-01

    The excess enthalpies of liquid alloys in the ternary system Ge-Pb-Te were determined at 1210 K in a heat flow calorimeter for five sections Ge y Pb 1-y -Te with y = 0.2, 0.4, 0.5, 0.6 and 0.8 and at 1153 K for Ge 0.5 Pb 0.5 -Te. The enthalpy surface in the ternary system is determined by a valley of exothermic minima, stretching from an exothermic minimum at the composition GeTe to one at the composition PbTe in the respective binaries. The excess enthalpies in the limiting metallic binary were adapted with the Redlich-Kister formalism. For the description of the thermodynamic functions in the ternary system the equation of Bonnier was taken using ternary coefficients. The calculated curves are in good agreement with the experimental data. (orig.)

  17. Neutron powder diffraction studies of Hydrogen and Denterium in Palladium Phosphides

    International Nuclear Information System (INIS)

    Andersson, Y.

    1986-01-01

    The use of the Rietveld-type profile refinements on neutron powder diffraction intensity data for determining crystallographic positions of hydrogen and deuterium in metal hydrides is illustrated by results obtained on some hydrogenated and deuterated palladium phosphides. The structural features of the solid solutions of hydrogen and deuterium in Pd/sb15/P/sb2/ Pd/sb6/P and Pd/sb3/P/sb1-u/ (0< u<0.28) are briefly presented and discussed

  18. Palladium-Catalyzed Tandem Oxidative Arylation/Olefination of Aromatic Tethered Alkenes/Alkynes.

    Science.gov (United States)

    Gao, Yang; Gao, Yinglan; Wu, Wanqing; Jiang, Huanfeng; Yang, Xiaobo; Liu, Wenbo; Li, Chao-Jun

    2017-01-18

    We describe herein a palladium-catalyzed tandem oxidative arylation/olefination reaction of aromatic tethered alkenes/alkynes for the synthesis of dihydrobenzofurans and 2 H-chromene derivatives. This reaction features a 1,2-difunctionalization of C-C π-bond with two C-H bonds using O 2 as terminal oxidant at room temperature. The products obtained are valuable synthons and important scaffolds in biological agents and natural products. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Carbon in palladium catalysts: A metastable carbide

    International Nuclear Information System (INIS)

    Seriani, Nicola; Mittendorfer, Florian; Kresse, Georg

    2010-01-01

    The catalytic activity of palladium towards selective hydrogenation of hydrocarbons depends on the partial pressure of hydrogen. It has been suggested that the reaction proceeds selectively towards partial hydrogenation only when a carbon-rich film is present at the metal surface. On the basis of first-principles simulations, we show that carbon can dissolve into the metal because graphite formation is delayed by the large critical nucleus necessary for graphite nucleation. A bulk carbide Pd 6 C with a hexagonal 6-layer fcc-like supercell forms. The structure is characterized by core level shifts of 0.66-0.70 eV in the core states of Pd, in agreement with experimental x-ray photoemission spectra. Moreover, this phase traps bulk-dissolved hydrogen, suppressing the total hydrogenation reaction channel and fostering partial hydrogenation. (author)

  20. Palladium-catalyzed, asymmetric Baeyer–Villiger oxidation of prochiral cyclobutanones with PHOX ligands

    KAUST Repository

    Petersen, Kimberly S.

    2011-06-01

    Described in this report is a general method for the conversion of prochiral 3-substituted cyclobutanones to enantioenriched γ-lactones through a palladium-catalyzed Baeyer-Villiger oxidation using phosphinooxazoline ligands in up to 99% yield and 81% ee. Lactones of enantiopurity ≥93% could be obtained through a single recrystallization step. Importantly, 3,3-disubtituted cyclobutanones produced enantioenriched lactones containing a β-quaternary center. © 2011 Elsevier Ltd. All rights reserved.

  1. Palladium(II-Catalyzed othro-C–H-Benzoxylation of 2-Arylpyridines by Oxidative Coupling with Aryl Acylperoxides

    Directory of Open Access Journals (Sweden)

    Wing-Yiu Yu

    2013-04-01

    Full Text Available A palladium(II-catalyzed ortho-benzoxylation of 2-arylpyridines with aryl acylperoxides was developed. With pyridyl as directing group, the benzoxylation reaction exhibits remarkable regioselectivity and excellent functional group tolerance, providing the products in up to 87% yield.

  2. Excessive Daytime Sleepiness

    Directory of Open Access Journals (Sweden)

    Yavuz Selvi

    2016-06-01

    Full Text Available Excessive daytime sleepiness is one of the most common sleep-related patient symptoms, with preva-lence in the community estimated to be as high as 18%. Patients with excessive daytime sleepiness may exhibit life threatening road and work accidents, social maladjustment, decreased academic and occupational performance and have poorer health than comparable adults. Thus, excessive daytime sleepiness is a serious condition that requires investigation, diagnosis and treatment primarily. As with most medical condition, evaluation of excessive daytime sleepiness begins a precise history and various objective and subjective tools have been also developed to assess excessive daytime sleepiness. The most common causes of excessive daytime sleepiness are insufficient sleep hygiene, chronic sleep deprivation, medical and psychiatric conditions and sleep disorders, such as obstructive sleep apnea, medications, and narcolepsy. Treatment option should address underlying contributors and promote sleep quantity by ensuring good sleep hygiene. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2016; 8(2: 114-132

  3. Nuclear heat-load limits for above-grade storage of solid transuranium wastes

    International Nuclear Information System (INIS)

    Clontz, B.G.

    1978-06-01

    Nuclear safety and heat load limits were established for above-grade storage of transuranium (TRU) wastes. Nuclear safety limits were obtained from a study by J.L. Forstner and are summarized. Heat load limits are based on temperature calculations for TRU waste drums stored in concrete containers (hats), and results are summarized. Waste already in storage is within these limits. The limiting factors for individual drum heat load limits were (1) avoidance of temperatures in excess of 190 0 F (decomposition temperature of anion resin) when anion resin is present in a concrete hat, and (2) avoidance of temperatures in excess of 450 0 F (ignition temperature of paper) at any point inside a waste drum. The limiting factor for concrete had heat load limits was avoidance of temperatures in excess of 265 0 F (melt point of high density polyethylene) at the drum liners. A temperature profile for drums and hats filled to recommended limits is shown. Equations and assumptions used were conservative

  4. Facile synthesis of palladium nanoparticle doped polyaniline nanowires in soft templates for catalytic applications

    Science.gov (United States)

    Kshirasagar, Krushna J.; Markad, Uddhav S.; Saha, Abhijit; Sharma, Kiran Kumar K.; Sharma, Geeta K.

    2017-02-01

    Palladium nanoparticles doped polyaniline (Pd-PANI) nanocomposite (NCs) is synthesized in surfactant based liquid crystalline mesophase by chemical oxidation followed by radiolysis. The confinement of the liquid crystalline mesophase facilitates polymerization of aniline monomers and their 1D growth into polyaniline (PANI) nanowires by using ammonium persulfate. The PANI nanowires have an average diameter of 30-40 nm. The in situ radiolytic reduction of palladium ions ensures uniform size distribution of the palladium (Pd) nanoparticles on the surface of the PANI nanowires. The synthesized Pd-PANI nanocomposites show wire like structures of PANI (diameter ~30-40 nm) on which Pd nanoparticles of the size 10 nm are decorated. The identical average diameter of the PANI nanowires before and post gamma irradiation suggest high stability of the PANI nanowires in liquid crystalline mesophase. Surface characterization of the NCs were carried out using BET and XPS. The catalytic activity of Pd-PANI NCs are investigated in the reduction of methylene blue (MB) and 4-nitro phenol (4-NP) by sodium borohydride (NaBH4). The kinetics of the Pd-PANI NCs catalysed reactions are analysed using the Langmuir-Hinshelwood model. The apparent rate constant (k app) for the MB and 4-NP reduction reactions is 29  ×  10-3 s-1 and 20  ×  10-3 s-1 respectively with an actual Pd catalyst loading of 2.665  ×  10-4 ppm. Further, the recyclability of the Pd-PANI NCs catalyst in both the reduction reactions shows the stability of the catalyst up to four reaction cycles tested in this investigation and the multifunctional nature of the catalyst. The study provides a new approach for the directional synthesis of conducting polymer-metal nanocomposites and their possible application as a nanocatalyst in environmental remediation.

  5. DTDGA impregnated XAD-16 beads for separation and recovery of palladium from acidic wastes

    International Nuclear Information System (INIS)

    Singh, Krishan Kant; Kanagare, Anant B.; Bairwa, K.K.; Manmohan Kumar; Bajaj, Parma N.; Ruhela, Ritesh; Singh, Ajoy K.; Hubli, Rajendra C.

    2014-01-01

    In the present study DTDGA extractant impregnated XAD16 polymeric beads (DTDGA- XAD16) were synthesized by wet chemical method and the beads were characterized by various techniques viz. FT-IR, Optical microscopy, SEM and TGA. The DTDGA-XAD 16 beads were evaluated for separation and recovery of palladium from high level waste solutions (HLW)

  6. Electrophysical properties of silicon doped by palladium-103 isotope

    International Nuclear Information System (INIS)

    Makhkamov, Sh.; Tursunov, N.A.; Sattiev, A.R.; Normurodov, A.B.

    2007-01-01

    The work is devoted to study of radiation physical processes taking place in Si under nuclear transmutation, Identification and determination of defects microstructure and homogeneities and their distribution, study of interactions of nuclear-transformed phosphorus isotopes with palladium atoms, and its effect on crystal properties. For examination monocrystalline silicon of n- and p-type conductivity with specific resistance from 1 to 40 Ω·cm, dislocation density ∼10 4 cm -2 and oxygen content ∼10 17 cm -3 has been applied. Doping of silicon plates by examined admixture has been carried out by thermal diffusion method within temperature range 1000-1250 deg. C for 0.5- 5 h. Irradiation of doped silicon was conducted by reactor neutron fluences 5·10 18 - 5·10 19 cm -2 with subsequent annealing at 1000 deg. C for 30 min. Efficiency of mixture centers formation in silicon, effect of concentration of formed mixture-defect centers on electro-physical, photoelectric and recombination parameters of doped silicon and revealing of type and state of generated defects have been controlled by electric, volume and X-ray fluorescent methods. On the base of spectroscopic researches it is shown, that in silicon forbidden zone after Pd diffusion in DLTS spectra peaks related with acceptor (E c -0.18 and E v +0.34 eV) levels, and peak responsible for level E v +0.32 eV of donor character caused by palladium impurity. It is shown, that irradiation of doped silicon samples by neutrons lead to nuclear transmutation of 102 Pd, 104 Pd in 103 Pd isotopes in the crystal volume with following electron capture in stable isotope 103m Rh

  7. Sensitization to palladium and nickel in Europe and the relationship with oral disease and dental alloys

    NARCIS (Netherlands)

    Muris, J.; Goossens, A.; Gonçalo, M.; Bircher, A.J.; Giménez-Arnau, A.; Foti, C.; Rustemeyer, T.; Feilzer, A.J.; Kleverlaan, C.J.

    2015-01-01

    Background The role of palladium and nickel sensitization in oral disease and dermatitis is not fully understood. Objectives To investigate whether sensitization to these metals was associated with exposure to dental alloys and oral and skin complaints/symptoms in a European multicentre study.

  8. Determination of the laterally homogeneous barrier height of palladium Schottky barrier diodes on n-Ge (111)

    CSIR Research Space (South Africa)

    Chawanda, A

    2011-05-01

    Full Text Available The authors have studied the experimental linear relationship between barrier heights and ideality factors for palladium (Pd) on bulk-grown (1 1 1) Sb-doped n-type germanium (Ge) metal-semiconductor structures with a doping density of about 2...

  9. Origin of excess heat generated during loading Pd-impregnated alumina powder with deuterium and hydrogen

    International Nuclear Information System (INIS)

    Dmitriyeva, O.; Cantwell, R.; McConnell, M.; Moddel, G.

    2012-01-01

    Highlights: ► We studied heat produced by hydrogen and deuterium in Pd-impregnated alumina powder. ► Samples were fabricated using light and heavy water isotopes and varied the gas used for loading. ► Incorporation of hydrogen and deuterium influenced the amount of heat released or consumed. ► Pd nanoparticles appear to catalyze hydrogen/deuterium (H/D) exchange chemical reactions. ► Anomalous heating can be accounted for by chemical rather than nuclear reactions. - Abstract: We studied heat production in Pd-impregnated alumina powder in the presence of hydrogen and deuterium gases, investigating claims of anomalous heat generated as a result of nuclear fusion, usually referred to as a low energy nuclear reaction (LENR). By selecting the water isotope used to fabricate the material and then varying the gas used for loading, we were able to influence the amount of heat released or consumed. We suggest that Pd in its nanoparticle form catalyzes hydrogen/deuterium (H/D) exchange reactions in the material. This hypothesis is supported by heat measurements, residual gas analysis (RGA) data, and calculations of energy available from H/D exchange reactions. Based on the results we conclude that the origin of the anomalous heat generated during deuterium loading of Pd-enriched alumina powder is chemical rather than nuclear.

  10. Scope and Limitations of Auxiliary-Assisted, Palladium-Catalyzed Arylation and Alkylation of sp2 and sp3 C-H Bonds

    Science.gov (United States)

    Nadres, Enrico T.; Santos, Gerson Ivan Franco; Shabashov, Dmitry; Daugulis, Olafs

    2013-01-01

    The scope of palladium-catalyzed, auxiliary-assisted direct arylation and alkylation of sp2 and sp3 C-H bonds of amine and carboxylic acid derivatives has been investigated. The method employs a palladium acetate catalyst, substrate, aryl, alkyl, benzyl, or allyl halide, and inorganic base in t-amyl alcohol or water solvent at 100-140 °C. Aryl and alkyl iodides as well as benzyl and allyl bromides are competent reagents in this transformation. Picolinic acid auxiliary is used for amine γ-functionalization and 8-aminoquinoline auxiliary is used for carboxylic acid β-functionalization. Some optimization of base, additives, and solvent is required for achieving best results. PMID:24090404

  11. External-beam PIXE spectrometry for the study of Punic jewellery (SW Spain): The geographical provenance of the palladium-bearing gold

    International Nuclear Information System (INIS)

    Ontalba Salamanca, M.A.; Gomez-Tubio, B.; Ortega-Feliu, I.; Respaldiza, M.A.; Luisa de la Bandera, M.; Ovejero Zappino, G.; Bouzas, A.; Gomez-Moron, A.

    2006-01-01

    This paper presents the study of a set of Punic gold items (400 B.C.), from the Museum of Cadiz (Spain). An external beam set-up has been employed for the absolutely non-destructive analysis of the objects. PIXE spectrometry has been performed in order to characterize the metallic alloys and the manufacturing techniques. Compositional differences have been found and soldering procedures have been identified. By comparison with the rings and other coetaneous jewellery, the presence of palladium in the bulk alloy of the earrings can be pointed out. The geographical provenance of the palladium-bearing gold is discussed based on geological and archaeological considerations

  12. External-beam PIXE spectrometry for the study of Punic jewellery (SW Spain): The geographical provenance of the palladium-bearing gold

    Energy Technology Data Exchange (ETDEWEB)

    Ontalba Salamanca, M.A. [Departamento de Fisica, Escuela Politecnica, Universidad de Extremadura, Avda. de la Universidad s/n., 10071 Caceres (Spain)]. E-mail: ontalba@unex.es; Gomez-Tubio, B. [Centro Nacional de Aceleradores, Sevilla (Spain); Ortega-Feliu, I. [Centro Nacional de Aceleradores, Sevilla (Spain); Respaldiza, M.A. [Centro Nacional de Aceleradores, Sevilla (Spain); Luisa de la Bandera, M. [Departamento de Arqueologia, Universidad de Sevilla (Spain); Ovejero Zappino, G. [Cobre Las Cruces SA, Gerena, Sevilla (Spain); Bouzas, A. [Instituto Andaluz de Patrimonio Historico, Sevilla (Spain); Gomez-Moron, A. [Instituto Andaluz de Patrimonio Historico, Sevilla (Spain)

    2006-08-15

    This paper presents the study of a set of Punic gold items (400 B.C.), from the Museum of Cadiz (Spain). An external beam set-up has been employed for the absolutely non-destructive analysis of the objects. PIXE spectrometry has been performed in order to characterize the metallic alloys and the manufacturing techniques. Compositional differences have been found and soldering procedures have been identified. By comparison with the rings and other coetaneous jewellery, the presence of palladium in the bulk alloy of the earrings can be pointed out. The geographical provenance of the palladium-bearing gold is discussed based on geological and archaeological considerations.

  13. Comparing the responses of rumen ciliate protozoa and bacteria to excess carbohydrate.

    Science.gov (United States)

    Teixeira, César R V; Lana, Rogério de Paula; Tao, Junyi; Hackmann, Timothy J

    2017-06-01

    When given excess carbohydrate, certain microbial species respond by storing energy (synthesizing reserve carbohydrate), but other species respond by dissipating the energy as heat (spilling energy). To determine the importance of these responses in the rumen microbial community, this study quantified the responses of mixed ciliate protozoa vs bacteria to glucose. We hypothesized that ciliates would direct more glucose to synthesis of reserve carbohydrate (and less to energy spilling) than would bacteria. Ciliates and bacteria were isolated from rumen fluid using filtration and centrifugation, resuspended in nitrogen-free buffer to limit growth, and dosed with 5 mM glucose. Compared with bacteria, ciliates consumed glucose >3-fold faster and synthesized reserve carbohydrate 4-fold faster. They incorporated 53% of glucose carbon into reserve carbohydrate-nearly double the value (27%) for bacteria. Energy spilling was not detected for ciliates, as all heat production (104%) was accounted by synthesis of reserve carbohydrate and endogenous metabolism. For bacteria, reserve carbohydrate and endogenous metabolism accounted for only 68% of heat production, and spilling was detected within 11 min of dosing glucose. These results suggest that ciliates alter the course of ruminal carbohydrate metabolism by outcompeting bacteria for excess carbohydrate, maximizing reserve carbohydrate synthesis, and minimizing energy spilling. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Comparison of Neural Networks and Regression Time Series in Estimating the Development of the Afternoon Price of Palladium on the New York Stock Exchange

    Directory of Open Access Journals (Sweden)

    Marek Vochozka

    2017-12-01

    Full Text Available Purpose of the article: Palladium is presently used for producing electronics, industrial products or jewellery, as well as products in the medical field. Its value is raised especially by its unique physical and chemical characteristics. Predicting the value of such a metal is not an easy matter (with regard to the fact that prices may change significantly in time. Methodology/methods: To carry out the analysis, London Fix Price PM data was used, i.e. amounts reported in the afternoon for a period longer than 10 years. To process the data, Statistica software is used. Linear regression is carried out using a whole range of functions, and subsequently regression via neural structures is performed, where several distributional functions are used again. Subsequently, 1000 neural networks are generated, out of which 5 proving the best characteristics are chosen. Scientific aim: The aim of the paper is to perform a regression analysis of the development of the palladium price on the New York Stock Exchange using neural structures and linear regression, then to compare the two methods and determine the more suitable one for a possible prediction of the future development of the palladium price on the New York Stock Exchange. Findings: Results are compared on the level of an expert perspective and the evaluator’s – economist’s experience. Within regression time lines, the curve obtained by the least squares methods via negative-exponential smoothing gets closest to Palladium price line development. Out of the neural networks, all 5 chosen networks prove to be the most practically useful. Conclusions: Because it is not possible to predict extraordinary situations and their impact on the palladium price (at most in the short term, but certainly not over a long period of time, simplification and the creation of a relatively simple model is appropriate and the result is useful.

  15. Urban Heat Wave Hazard Assessment

    Science.gov (United States)

    Quattrochi, Dale A.; Jedlovec, Gary; Meyer, Paul J.; LaFontaine, Frank J.; Crane, Dakota L.

    2016-01-01

    Heat waves are the largest cause of environment-related deaths globally. On average, over 6,000 people in the United States alone are hospitalized each summer due to excessive heat. Key elements leading to these disasters are elevated humidity and the urban heat island effect, which act together to increase apparent temperature and amplify the effects of a heat wave. Urban demographics and socioeconomic factors also play a role in determining individual risk. Currently, advisories of impending heat waves are often too generalized, with limited or no spatial variability over urban regions. This frequently contributes to a lack of specific response on behalf of the population. A goal of this project is to develop a product that has the potential to provide more specific heat wave guidance invoking greater awareness and action.

  16. Size effects in electronic and catalytic properties of unsupported palladium nanoparticles in electrooxidation of formic acid.

    Science.gov (United States)

    Zhou, Wei Ping; Lewera, Adam; Larsen, Robert; Masel, Rich I; Bagus, Paul S; Wieckowski, Andrzej

    2006-07-13

    We report a combined X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and chronoamperometry (CA) study of formic acid electrooxidation on unsupported palladium nanoparticle catalysts in the particle size range from 9 to 40 nm. The CV and CA measurements show that the most active catalyst is made of the smallest (9 and 11 nm) Pd nanoparticles. Besides the high reactivity, XPS data show that such nanoparticles display the highest core-level binding energy (BE) shift and the highest valence band (VB) center downshift with respect to the Fermi level. We believe therefore that we found a correlation between formic acid oxidation current and BE and VB center shifts, which, in turn, can directly be related to the electronic structure of palladium nanoparticles of different particle sizes. Clearly, such a trend using unsupported catalysts has never been reported. According to the density functional theory of heterogeneous catalysis, and mechanistic considerations, the observed shifts are caused by a weakening of the bond strength of the COOH intermediate adsorption on the catalyst surface. This, in turn, results in the increase in the formic acid oxidation rate to CO2 (and in the associated oxidation current). Overall, our measurements demonstrate the particle size effect on the electronic properties of palladium that yields different catalytic activity in the HCOOH oxidation reaction. Our work highlights the significance of the core-level binding energy and center of the d-band shifts in electrocatalysis and underlines the value of the theory that connects the center of the d-band shifts to catalytic reactivity.

  17. Origin of excess heat generated during loading Pd-impregnated alumina powder with deuterium and hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Dmitriyeva, O., E-mail: olga.dmitriyeva@colorado.edu [Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, CO 80309-0425 (United States); Coolescence LLC, 2450 Central Ave Ste F, Boulder, CO 80301 (United States); Cantwell, R.; McConnell, M. [Coolescence LLC, 2450 Central Ave Ste F, Boulder, CO 80301 (United States); Moddel, G. [Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, CO 80309-0425 (United States)

    2012-09-10

    Highlights: Black-Right-Pointing-Pointer We studied heat produced by hydrogen and deuterium in Pd-impregnated alumina powder. Black-Right-Pointing-Pointer Samples were fabricated using light and heavy water isotopes and varied the gas used for loading. Black-Right-Pointing-Pointer Incorporation of hydrogen and deuterium influenced the amount of heat released or consumed. Black-Right-Pointing-Pointer Pd nanoparticles appear to catalyze hydrogen/deuterium (H/D) exchange chemical reactions. Black-Right-Pointing-Pointer Anomalous heating can be accounted for by chemical rather than nuclear reactions. - Abstract: We studied heat production in Pd-impregnated alumina powder in the presence of hydrogen and deuterium gases, investigating claims of anomalous heat generated as a result of nuclear fusion, usually referred to as a low energy nuclear reaction (LENR). By selecting the water isotope used to fabricate the material and then varying the gas used for loading, we were able to influence the amount of heat released or consumed. We suggest that Pd in its nanoparticle form catalyzes hydrogen/deuterium (H/D) exchange reactions in the material. This hypothesis is supported by heat measurements, residual gas analysis (RGA) data, and calculations of energy available from H/D exchange reactions. Based on the results we conclude that the origin of the anomalous heat generated during deuterium loading of Pd-enriched alumina powder is chemical rather than nuclear.

  18. Palladium-catalyzed three-component reaction of N-tosyl hydrazones, isonitriles and amines leading to amidines.

    Science.gov (United States)

    Dai, Qiang; Jiang, Yan; Yu, Jin-Tao; Cheng, Jiang

    2015-12-04

    A palladium-catalyzed three-component reaction between N-tosyl hydrazones, aryl isonitriles and amines was developed, leading to amidines in moderate to good yields. This procedure features the rapid construction of amidine frameworks with high diversity and complexity. Ketenimines serve as intermediates, which encounter nucleophilic attack by amines to produce amidines.

  19. Metal Palladium Dispersed Inside Macroporous Ion-Exchange Resins: Textural Characterization and Accessibility to Gaseou Reactants

    Czech Academy of Sciences Publication Activity Database

    Biffis, A.; Jeřábek, Karel; D'Archivio, A. A.; Galantini, L.; Corain, B.

    2000-01-01

    Roč. 130, - (2000), s. 2327-2332 ISSN 0167-2991. [International Congress on Catalysis /12./. Granada, 09.07.2000-14.07.2000] Institutional research plan: CEZ:AV0Z4072921 Keywords : metal palladium * dispersed * ion-exchange resins Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.513, year: 2000

  20. Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene with alcohols

    Directory of Open Access Journals (Sweden)

    Katrina Tait

    2016-10-01

    Full Text Available Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene derivatives using alcohol nucleophiles were investigated. The optimal conditions were found to be 10 mol % PdCl2(CH3CN2 in methanol, offering yields up to 92%. The reaction was successful using primary, secondary and tertiary alcohol nucleophiles and was compatible with a variety of substituents on cyclopropanated oxabenzonorbornadiene. With unsymmetrical C1-substituted cyclopropanated 7-oxabenzonorbornadienes, the regioselectivity of the reaction was excellent, forming only one regioisomer in all cases.

  1. Tritium and neutron measurements from deuterated Pd-Si

    International Nuclear Information System (INIS)

    Claytor, T.N.; Tuggle, D.G.; Menlove, H.O.; Seeger, P.A.; Doty, W.R.; Rohwer, R.K.

    1990-01-01

    Evidence has been found for tritium and neutron production in palladium and silicon stacks when pulsed with a high electric current. These palladium-silicon stacks consist of alternating layers of pressed palladium and silicon powder. A pulsed high electric current is thought to promote non equilibrium conditions important for tritium and neutron production. More than 2000 hours of neutron counting time has been accumulated in a underground, low background, environment with high efficiency counters (21%). Neutron emission has occurred as infrequent burst or as low level emission lasting for up to 20 hours. In eight of 30 cells, excess tritium greater than 3 sigma has been observed. In each of these measurements, with the powder system, the ratio of tritium detected to total integrated total neutrons inferred has been anomalously high. Recent cells have shown reproducible tritium generation at a level of about 0.5 nCi/hr. Several hydrogen and air control cells have been run with no anomalous excess tritium or neutron emission above background. A significant amount of the total palladium inventory (18%) has been checked for tritium contamination by three independent means. 12 refs., 6 figs., 2 tabs

  2. Heat exchanger

    International Nuclear Information System (INIS)

    Leigh, D.G.

    1976-01-01

    The arrangement described relates particularly to heat exchangers for use in fast reactor power plants, in which heat is extracted from the reactor core by primary liquid metal coolant and is then transferred to secondary liquid metal coolant by means of intermediate heat exchangers. One of the main requirements of such a system, if used in a pool type fast reactor, is that the pressure drop on the primary coolant side must be kept to a minimum consistent with the maintenance of a limited dynamic head in the pool vessel. The intermediate heat exchanger must also be compact enough to be accommodated in the reactor vessel, and the heat exchanger tubes must be available for inspection and the detection and plugging of leaks. If, however, the heat exchanger is located outside the reactor vessel, as in the case of a loop system reactor, a higher pressure drop on the primary coolant side is acceptable, and space restriction is less severe. An object of the arrangement described is to provide a method of heat exchange and a heat exchanger to meet these problems. A further object is to provide a method that ensures that excessive temperature variations are not imposed on welded tube joints by sudden changes in the primary coolant flow path. Full constructional details are given. (U.K.)

  3. Anion-assisted trans-cis isomerization of palladium(II) phosphine complexes containing acetanilide functionalities through hydrogen bonding interactions.

    Science.gov (United States)

    Lu, Xiao-Xia; Tang, Hau-San; Ko, Chi-Chiu; Wong, Jenny Ka-Yan; Zhu, Nianyong; Yam, Vivian Wing-Wah

    2005-03-28

    The anion-assisted shift of trans-cis isomerization equilibrium of a palladium(II) complex containing acetanilide functionalities brought about by allosteric hydrogen bonding interactions has been established by UV/Vis, 1H NMR, 31P NMR and ESI-MS studies.

  4. In vitro formation of oropharyngeal biofilms on silicone rubber treated with a palladium/tin salt mixture

    NARCIS (Netherlands)

    Dijk, F; Westerhof, M; Busscher, HJ; van Luyn, MJA; van der Mei, HC

    2000-01-01

    Adhesion of yeasts and bacteria to silicone rubber is one of the first steps in the biodeterioration of indwelling, silicone rubber voice prostheses. In this paper, silicone rubber, so-called "Groningen button," voice prostheses were treated with a colloidal palladium/tin solution to form a thin

  5. Effective and selective recovery of gold and palladium ions from metal wastewater using a sulfothermophilic red alga, Galdieria sulphuraria.

    Science.gov (United States)

    Ju, Xiaohui; Igarashi, Kensuke; Miyashita, Shin-Ichi; Mitsuhashi, Hiroaki; Inagaki, Kazumi; Fujii, Shin-Ichiro; Sawada, Hitomi; Kuwabara, Tomohiko; Minoda, Ayumi

    2016-07-01

    The demand for precious metals has increased in recent years. However, low concentrations of precious metals dissolved in wastewater are yet to be recovered because of high operation costs and technical problems. The unicellular red alga, Galdieria sulphuraria, efficiently absorbs precious metals through biosorption. In this study, over 90% of gold and palladium could be selectively recovered from aqua regia-based metal wastewater by using G. sulphuraria. These metals were eluted from the cells into ammonium solutions containing 0.2M ammonium salts without other contaminating metals. The use of G. sulphuraria is an eco-friendly and cost-effective way of recovering low concentrations of gold and palladium discarded in metal wastewater. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Activity enhancement of Ag/mordenite catalysts by addition of palladium for the removal of nitrogen oxides from diesel engine exhaust gas

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, K.; Tsujimura, K. [New A.C.E. Institute Co., Ltd., Ibaraki (Japan); Shinoda, K.; Kato, T. [Mitsui Mining and Smelting Co., Ltd., Saitama (Japan)

    1998-01-15

    Various Ag-Pd/mordenite catalysts were prepared on washcoated honeycombs and tested in terms of NO{sub x} removal from diesel exhaust gas with (CH{sub 3}){sub 2}O as a reducing agent at a practical high level of space velocity. The activity was dependent upon the palladium loading. In terms of NO{sub x} removal, the order of catalytic activity was Ag(3)/Pd(0.01)/mordenite Ag(3)/Pd(0.1)/mordenite Ag(3)/mordenite catalyst Ag(3)/Pd(1.0)/mordenite. It was found that a relatively small loading of palladium on Ag/mordenite catalysts led to a significant improvement in catalytic activity over a wide range of temperatures. The properties of these catalysts were also investigated by the NH{sub 3} temperature programed desorption (TPD) and BET method. It was found that Ag(3)/Pd(0.01)/mordenite had a larger amount of acid sites. It was concluded that Ag/mordenite catalyst with a small amount of palladium can effectively remove NO{sub x} over a wide range of temperatures using (CH{sub 3}){sub 2}O as a reducing agent

  7. Synthesis, structural characterization, and pro-apoptotic activity of 1-indanone thiosemicarbazone platinum(II) and palladium(II) complexes: potential as antileukemic agents.

    Science.gov (United States)

    Gómez, Natalia; Santos, Diego; Vázquez, Ramiro; Suescun, Leopoldo; Mombrú, Alvaro; Vermeulen, Monica; Finkielsztein, Liliana; Shayo, Carina; Moglioni, Albertina; Gambino, Dinorah; Davio, Carlos

    2011-08-01

    In the search for alternative chemotherapeutic strategies against leukemia, various 1-indanone thiosemicarbazones, as well as eight novel platinum(II) and palladium(II) complexes, with the formula [MCl₂(HL)] and [M(HL)(L)]Cl, derived from two 1-indanone thiosemicarbazones were synthesized and tested for antiproliferative activity against the human leukemia U937 cell line. The crystal structure of [Pt(HL1)(L1)]Cl·2MeOH, where L1=1-indanone thiosemicarbazone, was solved by X-ray diffraction. Free thiosemicarbazone ligands showed no antiproliferative effect, but the corresponding platinum(II) and palladium(II) complexes inhibited cell proliferation and induced apoptosis. Platinum(II) complexes also displayed selective apoptotic activity in U937 cells but not in peripheral blood monocytes or the human hepatocellular carcinoma HepG2 cell line used to screen for potential hepatotoxicity. Present findings show that, in U937 cells, 1-indanone thiosemicarbazones coordinated to palladium(II) were more cytotoxic than those complexed with platinum(II), although the latter were found to be more selective for leukemic cells suggesting that they are promising compounds with potential therapeutic application against hematological malignancies. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Mass spectrometric determination of the thermodynamic excess properties of ternary Fe-Co-Cr melts

    International Nuclear Information System (INIS)

    Schmidt, Harald; Tomiska, Josef

    2004-01-01

    Computer-aided Knudsen cell mass spectrometry is used for the thermodynamic investigations on ternary Fe-Co-Cr melts over the entire range of composition. The thermodynamic mixing behavior has been determined by means of the 'digital intensity-ratio' (DIR) method. The ternary thermodynamically adapted power (TAP) series concept is used for the algebraic representation of the molar excess properties. The corresponding TAP parameters, and the values of the molar excess quantities Z E (T, x) (Z is the Gibbs energy G, heat of mixing H, entropy S) as well as the thermodynamic activities of all three constituents at 1950 K are presented

  9. Novel Base Metal-Palladium Catalytic Diesel Filter Coating with NO2 Reducing Properties

    DEFF Research Database (Denmark)

    Johansen, K.; Dahl, S.; Mogensen, G.

    2007-01-01

    A novel alternative base metal/palladium coat has been developed that has limited NO2 formation and which even removes NO2 in a wide temperature range.Soot combustion, HC conversion and CO conversion properties are comparable to current platinum based solutions but the coating has a more attracti...... solutions. Furthermore, durability results from base metal/Pd coated DPFs installed on operating taxis and related tests cycle data is given....

  10. Processing precious metals in a top-blown rotary converter

    Science.gov (United States)

    Whellock, John G.; Matousek, Jan W.

    1990-09-01

    Copper-nickel/platinum-palladium flotation concentrates produced by the Stillwater Mining Company were smelted and refined in an integrated pilot plant consisting of a submerged-arc electric furnace and top-blown rotary converter. The conversion of high-iron electric furnace mattes was achieved with apparent oxygen efficiencies in excess of 100 percent. Platinum and palladium recoveries averaged 99 percent, and copper and nickel recoveries were 94 percent.

  11. Fermi/LAT observations of dwarf galaxies highly constrain a dark matter interpretation of excess positrons seen in AMS-02, HEAT, and PAMELA

    Energy Technology Data Exchange (ETDEWEB)

    López, Alejandro [Michigan Center for Theoretical Physics, University of Michigan – Ann Arbor, 450 Church St., Ann Arbor (United States); Savage, Christopher [Nordita (Nordic Institute for Theoretical Physics), KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, Stockholm (Sweden); Spolyar, Douglas; Adams, Douglas Q., E-mail: aolopez@umich.edu, E-mail: chris@savage.name, E-mail: dspolyar@gmail.com, E-mail: doug.q.adams@gmail.com [Oskar Klein Centre for Cosmoparticle Physics, Stockholm University, Roslagstullsbacken 23, Roslagstullsbacken 21, Stockholm (Sweden)

    2016-03-01

    It is shown that a Weakly Interacting Massive dark matter Particle (WIMP) interpretation for the positron excess observed in a variety of experiments, HEAT, PAMELA, and AMS-02, is highly constrained by the Fermi/LAT observations of dwarf galaxies. In particular, this paper examines the annihilation channels that best fit the current AMS-02 data (Boudaud et al., 2014), specifically focusing on channels and parameter space not previously explored by the Fermi/LAT collaboration. The Fermi satellite has surveyed the γ-ray sky, and its observations of dwarf satellites are used to place strong bounds on the annihilation of WIMPs into a variety of channels. For the single channel case, we find that dark matter annihilation into (b b-bar ,e{sup +}e{sup -}, μ{sup +}μ{sup -}, τ{sup +}τ{sup -},4-e or 4-τ ) is ruled out as an explanation of the AMS positron excess (here b quarks are a proxy for all quarks, gauge and Higgs bosons). In addition, we find that the Fermi/LAT 2σ upper limits, assuming the best-fit AMS-02 branching ratios, exclude multichannel combinations into b b-bar and leptons. The tension between the results might relax if the branching ratios are allowed to deviate from their best-fit values, though a substantial change would be required. Of all the channels we considered, the only viable channel that survives the Fermi/LAT constraint and produces a good fit to the AMS-02 data is annihilation (via a mediator) to 4-μ, or mainly to 4-μ in the case of multichannel combinations.

  12. Process for adapting a heat source and a thermal machine by temporary heat storage

    International Nuclear Information System (INIS)

    Cahn, R.P.; Nicholson, E.W.

    1975-01-01

    The process described is intended to ensure the efficient use of the heat from a nuclear reactor or from a furnace burning fossil fuel at constant power, and of a boiler in a power station comprising a multi-stage steam turbine, the steam extracted from the turbine being used for pre-heating the boiler feed water. This process is most flexible with a varying load. It includes the high temperature storage of the excess heat energy in a low vapor pressure storage liquid (hydrocarbon oils, molten salts or liquid metals) at atmospheric pressure when the demand is low; then, when the energy demand is at its height, the reduction of steam extraction from the turbine with simultaneous utilisation of the hot heat storage liquid for the various maintenance heating functions of the power station by heat exchange, so that the heat can expand totally in the turbine with generation of energy [fr

  13. Excess cardiovascular mortality associated with cold spells in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Kyncl Jan

    2009-01-01

    Full Text Available Abstract Background The association between cardiovascular mortality and winter cold spells was evaluated in the population of the Czech Republic over 21-yr period 1986–2006. No comprehensive study on cold-related mortality in central Europe has been carried out despite the fact that cold air invasions are more frequent and severe in this region than in western and southern Europe. Methods Cold spells were defined as periods of days on which air temperature does not exceed -3.5°C. Days on which mortality was affected by epidemics of influenza/acute respiratory infections were identified and omitted from the analysis. Excess cardiovascular mortality was determined after the long-term changes and the seasonal cycle in mortality had been removed. Excess mortality during and after cold spells was examined in individual age groups and genders. Results Cold spells were associated with positive mean excess cardiovascular mortality in all age groups (25–59, 60–69, 70–79 and 80+ years and in both men and women. The relative mortality effects were most pronounced and most direct in middle-aged men (25–59 years, which contrasts with majority of studies on cold-related mortality in other regions. The estimated excess mortality during the severe cold spells in January 1987 (+274 cardiovascular deaths is comparable to that attributed to the most severe heat wave in this region in 1994. Conclusion The results show that cold stress has a considerable impact on mortality in central Europe, representing a public health threat of an importance similar to heat waves. The elevated mortality risks in men aged 25–59 years may be related to occupational exposure of large numbers of men working outdoors in winter. Early warnings and preventive measures based on weather forecast and targeted on the susceptible parts of the population may help mitigate the effects of cold spells and save lives.

  14. Palladium Loaded on Magnetic Nanoparticles as Efficient and Recyclable Catalyst for the Suzuki- Miyaura Reaction

    Directory of Open Access Journals (Sweden)

    H. Khojasteh

    2015-07-01

    Full Text Available Palladium is the best metal catalyst for Suzuki cross coupling reaction for synthesize of unsymmetrical biaryl compounds. But its high cost limits its application in wide scale. Using of nanoscale particles as active catalytic cites is a good approach for reducing needed noble metal. By loading precious nanoparticles on magnetic nanocores as a support, recycling and reusing of catalyst will be possible. Magnetic nanoparticles have super paramagnetic feature and applying an external magnetic field can collect the supported catalyst from reaction milieu simply. In this work new palladium catalyst immobilized on modified magnetic nanoparticles containing NNO donor atoms were synthesized. Then the catalyst characterized by FT-IR spectroscopy, thermogravimetric analysis, X-ray diffraction and ICP. Prepared catalyst showed high activity in the Suzuki– Miyaura cross-coupling reaction of phenylboronic acid with aryl halides. Activity, Pd loading, reusability and Pd leaching of catalyst were studied. Results showed that the supported catalyst has the advantage to be completely recoverable with the simple application of an external magnetic field.

  15. Mild Palladium Catalyzed ortho C-H Bond Functionalizations of Aniline Derivatives.

    Science.gov (United States)

    Tischler, Ms Orsolya; Tóth, Mr Balázs; Novák, Zoltán

    2017-02-01

    This account collects the developments and transformations which avoid the utilization of harsh reaction conditions in the field of palladium catalyzed, ortho-directed C-H activation of aniline derivatives from the first attempts to up-to-date results, including the results of our research laboratory. The discussed functionalizations performed under mild conditions include acylation, olefination, arylation, alkylation, alkoxylation reactions. Beside the optimization studies and the synthetic applications mechanistic investigations are also presented. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Spectroscopic study of low-temperature hydrogen absorption in palladium

    Energy Technology Data Exchange (ETDEWEB)

    Ienaga, K., E-mail: ienaga@issp.u-tokyo.ac.jp; Takata, H.; Onishi, Y.; Inagaki, Y.; Kawae, T. [Department of Applied Quantum Physics, Faculty of Engineering, Kyushu University, Motooka, Nishi-Ku, Fukuoka 819-0395 (Japan); Tsujii, H. [Department of Physics, Faculty of Education, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Kimura, T. [Department of Physics, Kyushu University, Hakozaki, Higashi-Ku, Fukuoka 812-8581 (Japan)

    2015-01-12

    We report real-time detection of hydrogen (H) absorption in metallic palladium (Pd) nano-contacts immersed in liquid H{sub 2} using inelastic electron spectroscopy (IES). After introduction of liquid H{sub 2}, the spectra exhibit the time evolution from the pure Pd to the Pd hydride, indicating that H atoms are absorbed in Pd nano-contacts even at the temperature where the thermal process is not expected. The IES time and bias voltage dependences show that H absorption develops by applying bias voltage 30 ∼ 50 mV, which can be explained by quantum tunneling. The results represent that IES is a powerful method to study the kinetics of high density H on solid surface.

  17. Synthesis, characterization, antimicrobial and antitumor reactivity of new palladium(II) complexes with methionine and tryptophane coumarine derivatives

    Science.gov (United States)

    Stojković, Danijela Lj; Jevtić, Verica V.; Vuković, Nenad; Vukić, Milena; Čanović, Petar; Zarić, Milan M.; Mišić, Milena M.; Radovanović, Dragče M.; Baskić, Dejan; Trifunović, Srećko R.

    2018-04-01

    In reaction of 3-acetyl-4-hydroxy coumarine with methionine methyl ester hydrochloride and tryptophane methyl ester hydrochloride the corresponding enamine ligands were obtained. Palladium (II) complexes were prepared in reaction of potassium-tetrachloridopalladate (II) and corresponding enamine. All compounds were characterized by microanalysis, infrared, 1H and 13C NMR spectroscopy. In vitro antitumor activity of the mentioned ligands and corresponding palladium (II) complexes, as well as me-Gly and me-Val ligands and [Pd (me-Gly)]Cl and [Pd (me-Val)2] complexes was determined by MTT assay against two leukemia cell lines (JVM-13 and MOLT-4) and against primary leukemic cells isolated from chronic lymphocytic leukemia (CLL) patients. Antimicrobial activity of the tested compound was evaluated by determining the minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) against three reference bacterial strains: E. faecalis, P. aeruginosa, S. aureus and one clinical isolate of yeast: Candida spp.

  18. 16 CFR 23.7 - Misuse of the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium,” and “osmium.”

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Misuse of the words âplatinum,â âiridium,â... § 23.7 Misuse of the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium,” and “osmium.” (a) It is unfair or deceptive to use the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium...

  19. Palladium nanoparticles in electrochemical sensing of trace terazosin in human serum and pharmaceutical preparations

    Energy Technology Data Exchange (ETDEWEB)

    Sefid-sefidehkhan, Yasaman [Department of Chemistry, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of); Nekoueian, Khadijeh [Laboratory of Green Chemistry, Faculty of Technology, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Amiri, Mandana, E-mail: mandanaamiri@uma.ac.ir [Department of Chemistry, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of); Sillanpaa, Mika [Laboratory of Green Chemistry, Faculty of Technology, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Eskandari, Habibollah [Department of Chemistry, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of)

    2017-06-01

    In this approach, palladium nanoparticle film was simply fabricated on the surface of carbon paste electrode by electrochemical deposition method. The film was characterized using scanning electron microscopy, electrochemical impedance spectroscopy and cyclic voltammetry. The prepared electrode exhibited an excellent electrocatalytic activity toward detection of trace amounts of terazosin, which is an antihypertensive drug. Under the optimum experimental conditions, a linear range of 1.0 × 10{sup −8}–1.0 × 10{sup −3} mol L{sup −1} with a detection limit of 1.9 × 10{sup −9} mol L{sup −1} was obtained for determination of terazosin using differential pulse voltammetry as a sensitive method. The efficiency of palladium nanoparticle film on the surface of carbon paste electrode successfully proved for determination of terazosin in pharmaceutical sample and human serum sample with promising recovery results. The effect of some foreign species has been studied. - Highlights: • PdNPs were simply fabricated by electrochemical deposition. • PdNPs exhibited an excellent electrocatalytic activity toward oxidation of terazosin. • Terazosin has been determined in pharmaceutical sample and human serum sample.

  20. Palladium nanoparticles anchored on graphene nanosheets: Methanol, ethanol oxidation reactions and their kinetic studies

    KAUST Repository

    Nagaraju, Doddahalli H.

    2014-12-01

    Palladium nanoparticles decorated graphene (Gra/Pd nanocomposite) was synthesized by simultaneous chemical reduction of graphene oxide and palladium salt in a single step. The negatively charged graphene oxide (GO) facilitates uniform distribution of Pd2+ ions onto its surface. The subsequent reduction by hydrazine hydrate provides well dispersed Pd nanoparticles decorated graphene. Different amount of Pd nanoparticles on graphene was synthesized by changing the volume to weight ratio of GO to PdCl2. X-ray diffraction studies showed FCC lattice of Pd with predominant (1 1 1) plane. SEM and TEM studies revealed that thin graphene nanosheets are decorated by Pd nanoparticles. Raman spectroscopic studies revealed the presence of graphene nanosheets. The electro-catalytic activity of Gra/Pd nanocomposites toward methanol and ethanol oxidation in alkaline medium was evaluated by cyclic voltammetric studies. 1:1 Gra/Pd nanocomposite exhibited good electro-catalytic activity and efficient electron transfer. The kinetics of electron transfer was studied using chronoamperometry. Improved electro-catalytic activity of 1:1 Gra/Pd nanocomposite toward alcohol oxidation makes it as a potential anode for the alcohol fuel cells. © 2014 Elsevier Ltd.