Synthesis of plutonium trifluoride by hydro-fluorination and novel thermodynamic data for the PuF3-LiF system

PuF3 was synthetized by hydro-fluorination of PuO2 and subsequent reduction of the product by hydrogenation. The obtained PuF3 was analysed by X-Ray Diffraction (XRD) and found phase-pure. High purity was also confirmed by the melting point analysis using Differential Scanning Calorimetry (DSC). PuF3 was then used for thermodynamic assessment of the PuF3-LiF system. Phase equilibrium points and enthalpy of fusion of the eutectic composition were measured by DSC. XRD analyses of selected samples after DSC measurement confirm that after solidification from the liquid, the system returns to a mixture of LiF and PuF3

Isobaric heat capacity of solid and liquid thorium tetrafluoride

The isobaric heat capacity of solid and liquid thorium tetrafluoride was determined by two calorimetry methods: drop calorimetry to obtain the enthalpy increments in the range from 430 to 1600 K and DSC to obtain the high temperature heat capacity of solid and liquid thorium tetrafluoride using the step method. Adjustments to the experimental setups were developed and implemented to increase accuracy and reduce uncertainty of the obtained data

Physico-chemical properties of the system (LiF-NaF)eut-LaF3 – Phase equilibria, density and volume properties, electrical conductivity andsurface tension

A detailed physico-chemical investigation of molten system (LiF-NaF)eut-LaF3 up to 15 mol% of LaF3 has been done. The phase equilibria were measured by two independent methods (TA and DSC) and consequently Calphad modelling and calculation was performed in order to interpret obtained experimental data. Additional physico-chemical properties like density, electrical conductivity and surface tension were measured. It was found that all investigated properties reflect the ionic changes in the melt providing consistent data, i.e. the most significant changes in these properties are observed at ca. 10 mol% LaF3. The volume propertieswere calculated, as well, providing information about volume expansion. Also temperature anomalous behaviour was observed for the electrical conductivity and surface tension

Experimental investigation and thermodynamic modelling of the ThF₄-PuF₃ phase diagram

Phase equilibria in the ThF4-PuF3 system were measured by differential scanning calorimetry. Samples were encapsulated to prevent leakage during the measurements and to prevent fluoride contamination of the instrument. Formation of intermediate compounds and solid solutions was investigated by X-ray diffraction. A thermodynamic model based on the CALPHAD approach was developed for the measured system. Good fit between measurements and phase equilibria calculated using the model was achieved.RST/Reactor Physics and Nuclear Material

Vaporization behaviour of a PuF₃-containing fuel mixture for the Molten Salt Fast Reactor

The mixture LiF-ThF4-UF4-PuF3 (77.5–6.6-12.3–3.6 mol%), a fuel option for the Molten Salt Fast Reactor (MSFR), has been measured by differential scanning calorimetry (DSC) for determination of phase transitions, and by Knudsen effusion mass spectrometry (KEMS) for measurement of partial vapour pressures. The boiling point of the mixture was determined by extrapolation of total vapour pressure to 1 bar. Thermodynamic calculations were performed and compared with the experimental results. Novel experimental data on pure plutonium trifluoride are presented: melting point, vaporization enthalpy, vapour pressure and ionization energies by electron impact.RST/Reactor Physics and Nuclear Material

ACTonHEALTH study protocol: promoting psychological flexibility with activity tracker and mHealth tools to foster healthful lifestyle for obesity and other chronic health conditions

BackgroundObesity and the state of being overweight are increasing steadily and becoming a global epidemic. Recent research reports 64% of the adult population as overweight in Europe and the USA. The social and economic impacts are increasing, and most of the rehabilitation programs, while effective in the short term, do not produce long-lasting results. An explanatory model from a behavioral perspective can describe the phenomena with the lack of sources of reinforcement related to healthful habits in a daily life context.Methods/designA randomized clinical trial combining single-subject studies and a four-arm group design will be conducted to compare the effect of the current standard in obesity treatment to Acceptance and Commitment Therapy (ACT) and wearable technology at different times, before starting intervention, at the end, and at follow-up visits of 3, 6, and 12months measuring changes over time of physical activity and psychological well-being.DiscussionThe goal of this project, combining ACT and wearable technology, is to develop an effective intervention, efficient and sustainable, which even after discharge can provide adequate contingencies of reinforcement in the natural environment, integrating systematic measurements, continuous feedback, and individualized, values-based objectives. The intervention is aimed to provide a contingent reinforcement for healthful behaviors instead of reinforcing only the achievement of a significant weight loss.The aim of the project, combining Acceptance and Commitment Therapy and Wearable Technology, is to develop an effective, efficient and sustainable intervention able to provide a contingent reinforcement for healthy behaviors. The intervention is aimed to promote adequate healthy behaviors in the natural environment, integrating systematic measurements, continuous feedback and individualized values-based objectives, instead of reinforcing only the achievement of a significant weight loss.Trial registrationClinicalTrials.gov, NCT03351712. Registered on 24 November 2017

ACTonHEALTH study protocol: Promoting psychological flexibility with activity tracker and mHealth tools to foster healthful lifestyle for obesity and other chronic health conditions

Background: Obesity and the state of being overweight are increasing steadily and becoming a global epidemic. Recent research reports 64% of the adult population as overweight in Europe and the USA. The social and economic impacts are increasing, and most of the rehabilitation programs, while effective in the short term, do not produce long-lasting results. An explanatory model from a behavioral perspective can describe the phenomena with the lack of sources of reinforcement related to healthful habits in a daily life context. Methods/design: A randomized clinical trial combining single-subject studies and a four-arm group design will be conducted to compare the effect of the current standard in obesity treatment to Acceptance and Commitment Therapy (ACT) and wearable technology at different times, before starting intervention, at the end, and at follow-up visits of 3, 6, and 12 months measuring changes over time of physical activity and psychological well-being. Discussion: The goal of this project, combining ACT and wearable technology, is to develop an effective intervention, efficient and sustainable, which even after discharge can provide adequate contingencies of reinforcement in the natural environment, integrating systematic measurements, continuous feedback, and individualized, values-based objectives. The intervention is aimed to provide a contingent reinforcement for healthful behaviors instead of reinforcing only the achievement of a significant weight loss. The aim of the project, combining Acceptance and Commitment Therapy and Wearable Technology, is to develop an effective, efficient and sustainable intervention able to provide a contingent reinforcement for healthy behaviors. The intervention is aimed to promote adequate healthy behaviors in the natural environment, integrating systematic measurements, continuous feedback and individualized values-based objectives, instead of reinforcing only the achievement of a significant weight loss. Trial registration: ClinicalTrials.gov, NCT03351712. Registered on 24 November 2017