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Energy-efficient CO2 hydrogenation with fast response using photoexcitation of CO2 adsorbed on metal catalysts.
Many heterogeneous catalytic reactions occur at high temperatures, which may cause large energy costs, poor safety, and thermal degradation of catalysts. Here, we propose a light-assisted surface reaction, which catalyze the surface reaction using both light and heat as an energy source. Conventional metal catalysts such as ruthenium, rhodium, platinum, nickel, and copper were tested for CO2 hydrogenation, and ruthenium showed the most distinct change upon light irradiation. CO2 was strongly adsorbed onto ruthenium surface, forming hybrid orbitals. The band gap energy was reduced significantly upon hybridization, enhancing CO2 dissociation. The light-assisted CO2 hydrogenation used only 37% of the total energy with which the CO2 hydrogenation occurred using only thermal energy. The CO2 conversion could be turned on and off completely with a response time of only 3 min, whereas conventional thermal reaction required hours. These unique features can be potentially used for on-demand fuel production with minimal energy input
An EMF cell with a nitrogen solid electrolyte-on the transference of nitrogen ions in yttria-stabilized zirconia
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The mobility and electrochemical activity of nitrogen inside and/or at the surface of ionic compounds is of fundamental, as well as of possibly practical, relevance. In order to better understand the role of nitrogen anions in solid electrolytes, we measured the transference number of nitrogen in yttria-stabilized zirconia (YSZ) by a concentration cell technique as a function of oxygen activity at different temperatures in the range of 1023 ≤ T/K ≤ 1123. YSZ doped with 1.9 wt% of N (YSZ:N) turned out to have an appreciable nitrogen transference number, which increased from 0 to 0.1 with decreasing oxygen activity in the range of −20 < logaO2 < −14. The stability of N in YSZ:N, however, has yet to be elucidated under oxidizing conditions.DFG, SPP 1136, Substitutionseffekte in ionischen Festkörper
An EMF cell with a nitrogen solid electrolyte-on the transference of nitrogen ions in yttria-stabilized zirconia
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The mobility and electrochemical activity of nitrogen inside and/or at the surface of ionic compounds is of fundamental, as well as of possibly practical, relevance. In order to better understand the role of nitrogen anions in solid electrolytes, we measured the transference number of nitrogen in yttria-stabilized zirconia (YSZ) by a concentration cell technique as a function of oxygen activity at different temperatures in the range of 1023 ≤ T/K ≤ 1123. YSZ doped with 1.9 wt% of N (YSZ:N) turned out to have an appreciable nitrogen transference number, which increased from 0 to 0.1 with decreasing oxygen activity in the range of −20 < logaO2 < −14. The stability of N in YSZ:N, however, has yet to be elucidated under oxidizing conditions.DFG, SPP 1136, Substitutionseffekte in ionischen Festkörper
Phenomenological Theory of Superconductivity and Magnetism in HoDyNiBC
The coexistence of the superconductivity and magnetism in the
HoDyNiBC is studied by using Ginzburg-Landau theory. This
alloy shows the coexistence and complex interplay of superconducting and
magnetic order. We propose a phenomenological model which includes two magnetic
and two superconducting order parameters accounting for the multi-band
structure of this material. We describe phenomenologically the magnetic
fluctuations and order and demonstrate that they lead to anomalous behavior of
the upper critical field. The doping dependence of in
HoDyNiBC showing a reentrance behavior are analyzed
yielding a very good agreement with experimental data.Comment: 4 pages, 3 figures, REVTeX, submitted to PR
Preliminary effects and acceptability of a co-produced physical activity referral intervention
Objectives: To explore the preliminary effects and acceptability of a co-produced physical activity referral intervention.
Study Design: Longitudinal design with data collected at baseline and post a 12-week physical activity referral intervention.
Setting. Community leisure centre.
Methods: 32 adults with controlled lifestyle-related health conditions took part in a physical activity referral intervention (co-produced by a multidisciplinary stakeholder group) comprising 12 weeks’ subsidised fitness centre access plus four behaviour change consultations. A complete case analysis (t-tests and magnitude-based inferences) was conducted to assess baseline-to-12-week change in physical activity, cardiometabolic, and psychological measures. Semi-structured interviews were conducted (n=12) to explore experiences of the intervention.
Results: Mean improvements were observed in cardiorespiratory fitness-2 (3.6 ml.kg.-1min-1 (95% confidence interval 1.9 to 5.4) P<0.001) and moderate-to-vigorous physical activity (12.6 min.day (95% CI 4.3 to 29.6) P=0.013). Participants were positive about the support from exercise referral practitioners, but experienced some challenges in a busy and under staffed gym environment.
Conclusions: A co-produced physical activity referral intervention elicited short-term improvements in physical activity and cardiometabolic health. Further refinements may be required, via ongoing feedback between stakeholders, researchers and service users, to achieve the intended holistic physical activity focus of the intervention, prior to a definitive trial
Clinical course, costs and predictive factors for response to treatment in carpal tunnel syndrome: The PALMS study protocol
Background Carpal tunnel syndrome (CTS) is the most common neuropathy of the upper limb and a significant contributor to hand functional impairment and disability. Effective treatment options include conservative and surgical interventions, however it is not possible at present to predict the outcome of treatment. The primary aim of this study is to identify which baseline clinical factors predict a good outcome from conservative treatment (by injection) or surgery in patients diagnosed with carpal tunnel syndrome. Secondary aims are to describe the clinical course and progression of CTS, and to describe and predict the UK cost of CTS to the individual, National Health Service (NHS) and society over a two year period. Methods/Design In this prospective observational cohort study patients presenting with clinical signs and symptoms typical of CTS and in whom the diagnosis is confirmed by nerve conduction studies are invited to participate. Data on putative predictive factors are collected at baseline and follow-up through patient questionnaires and include standardised measures of symptom severity, hand function, psychological and physical health, comorbidity and quality of life. Resource use and cost over the 2 year period such as prescribed medications, NHS and private healthcare contacts are also collected through patient self-report at 6, 12, 18 and 24 months. The primary outcome used to classify treatment success or failures will be a 5-point global assessment of change. Secondary outcomes include changes in clinical symptoms, functioning, psychological health, quality of life and resource use. A multivariable model of factors which predict outcome and cost will be developed. Discussion This prospective cohort study will provide important data on the clinical course and UK costs of CTS over a two-year period and begin to identify predictive factors for treatment success from conservative and surgical interventions
Superconductivity in a single C60 transistor
Single molecule transistors (SMTs) are currently attracting enormous
attention as possible quantum information processing devices. An intrinsic
limitation to the prospects of these however is associated to the presence of a
small number of quantized conductance channels, each channel having a high
access resistance of at best =12.9 k. When the
contacting leads become superconducting, these correlations can extend
throughout the whole system by the proximity effect. This not only lifts the
resistive limitation of normal state contacts, but further paves a new way to
probe electron transport through a single molecule. In this work, we
demonstrate the realization of superconducting SMTs involving a single C60
fullerene molecule. The last few years have seen gate-controlled Josephson
supercurrents induced in the family of low dimensional carbon structures such
as flakes of two-dimensional graphene and portions of one-dimensional carbon
nanotubes. The present study involving a full zero-dimensionnal fullerene
completes the picture.Comment: 12 pages, 3 figure
Observation of Andreev reflection in the c-axis transport of Bi_2Sr_2CaCu_2O_{8+x} single crystals near T_c and search for the preformed-pair state
We observed an enhancement of the -axis differential conductance around
the zero-bias in AuBiSrCaCuO (Bi2212) junctions near the
superconducting transition temperature . We attribute the conductance
enhancement to the Andreev reflection between the surface Cu-O bilayer with
suppressed superconductivity and the neighboring superconducting inner bilayer.
The continuous evolution from depression to an enhancement of the zero-bias
differential conductance, as the temperature approaches from below,
points to weakening of the barrier strength of the non-superconducting layer
between adjacent Cu-O bilayers. We observed that the conductance enhancement
persisted up to a few degrees above in junctions prepared on slightly
overdoped Bi2212 crystals. However, no conductance enhancement was observed
above in underdoped crystals, although recently proposed theoretical
consideration suggests an even wider temperature range of enhanced zero-bias
conductance. This seems to provide negative perspective to the existence of the
phase-incoherent preformed pairs in the pseudogap state.Comment: 17 pages including 4 figure
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