A spin- and angle-resolving photoelectron spectrometer

A new type of hemispherical electron energy analyzer that permits angle and spin resolved photoelectron spectroscopy has been developed. The analyzer permits standard angle resolved spectra to be recorded with a two-dimensional detector in parallel with spin detection using a mini-Mott polarimeter. General design considerations as well as technical solutions are discussed and test results from the Au(111) surface state are presented

The effect of temporary parental benefit on children’s antibiotics use: Evidence from a natural field experiment

Prudent use of antibiotics is important to delay the spread of resistance. This paper analyses the effect on children’s antibiotics use of a reform of the temporary parental benefit in Sweden. The reform increased the maximum compensation for this benefit. The level of compensation for social security may affect the propensity of a patient or parent to push for a prescription for antibiotics, as a less generous compensation makes it more expensive to be absent from work and since there is widespread overconfidence in the effectiveness of antibiotics. Using municipality level data, we show that the reform resulted in a reduction in children’s antibiotics use by about five per cent. The result is fairly robust to alternative empirical strategies, suggesting that welfare policies can have important indirect effects that should be taken into account

Motivation pour apprendre une langue étrangère – une question de visualisation? : Les effets de trois activités en cours de français sur la motivation d’élèves suédois

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Accretion process, magnetic fields, and apsidal motion in the pre-main sequence binary DQ Tau

Classical T Tauri stars (CTTSs) are young stellar objects that accrete materials from their accretion disc influenced by their strong magnetic field. The magnetic pressure truncates the disc at a few stellar radii and forces the material to leave the disc plane and fall onto the stellar surface by following the magnetic field lines. However, this global scheme may be disturbed by the presence of a companion interacting gravitationally with the accreting component. This work is aiming to study the accretion and the magnetic field of the tight eccentric binary DQ Tau, composed of two equal-mass ($\sim$ 0.6 \msun ) CTTSs interacting at different orbital phases. We investigated the variability of the system using a high-resolution spectroscopic and spectropolarimetric monitoring performed with ESPaDOnS at the CFHT. We provide the first ever magnetic field analysis of this system, the Zeeman-Doppler imaging revealed a stronger magnetic field for the secondary than the primary (1.2 kG and 0.5 kG, respectively), but the small-scale fields analysed through Zeeman intensification yielded similar strengths (about 2.5 kG). The magnetic field topology and strengths are compatible with the accretion processes on CTTSs. Both components of this system are accreting, with a change of the main accretor during the orbital motion. In addition, the system displays a strong enhancement of the mass accretion rate at periastron and apastron. We also discovered, for the first time in this system, the apsidal motion of the orbital ellipse.Comment: 18 pages, 20 figures. Accepted for publication in MNRA

Potentials in Li-Ion Batteries Probed by Operando Ambient Pressure Photoelectron Spectroscopy

The important electrochemical processes in a battery happen at the solid/liquid interfaces. Operando ambient pressure photoelectron spectroscopy (APPES) is one tool to study these processes with chemical specificity. However, accessing this crucial interface and identifying the interface signal are not trivial. Therefore, we present a measurement setup, together with a suggested model, exemplifying how APPES can be used to probe potential differences over the electrode/electrolyte interface, even without direct access to the interface. Both the change in electron electrochemical potential over the solid/liquid interface, and the change in Li chemical potential of the working electrode (WE) surface at Li-ion equilibrium can be probed. Using a Li4Ti5O12 composite as a WE, our results show that the shifts in kinetic energy of the electrolyte measured by APPES can be correlated to the electrochemical reactions occurring at the WE/electrolyte interface. Different shifts in kinetic energy are seen depending on if a phase transition reaction occurs or if a single phase is lithiated. The developed methodology can be used to evaluate charge transfer over the WE/electrolyte interface as well as the lithiation/delithiation mechanism of the WE

Probing Electrochemical Potential Differences over the Solid/Liquid Interface in Li-Ion Battery Model Systems

The electrochemical potential difference (Δμ̅) is the driving force for the transfer of a charged species from one phase to another in a redox reaction. In Li-ion batteries (LIBs), Δμ̅ values for both electrons and Li-ions play an important role in the charge-transfer kinetics at the electrode/electrolyte interfaces. Because of the lack of suitable measurement techniques, little is known about how Δμ̅ affects the redox reactions occurring at the solid/liquid interfaces during LIB operation. Herein, we outline the relations between different potentials and show how ambient pressure photoelectron spectroscopy (APPES) can be used to follow changes in Δμ̅e over the solid/liquid interfaces operando by measuring the kinetic energy (KE) shifts of the electrolyte core levels. The KE shift versus applied voltage shows a linear dependence of ∼1 eV/V during charging of the electrical double layer and during solid electrolyte interphase formation. This agrees with the expected results for an ideally polarizable interface. During lithiation, the slope changes drastically. We propose a model to explain this based on charge transfer over the solid/liquid interface

The role of anionic processes in Li1−xNi0.44Mn1.56O4 studied by resonant inelastic X-ray scattering

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Brandteknisk riskvärdering av Bildningscentrum i Flen

This study has been carried out, as part of the course Fire Safety Evaluation at Lund Technical University, to assess the fire safety of an elementary school in Flen. The study is made up of three parts, an overview and description of the school, an analysis of possible fire scenarios within the school compound, and a set of action proposals based on the findings from the analysis. In the analysis, we identified several possible fire scenarios and subsequently limited these to three which were – based on a quantitative risk assessment – selected for further analysis. The chosen scenarios consist of fire in auditorium, fire in toilet, and fire in mini-auditorium. The computer programs Fire Dynamics Simulator and Pathfinder were used to simulate smoke spread and evacuation respectively. The results of the report show that certain measures may be required to assure the personal safety of staff and students. These measures can be summarized to a lowered number of people or/and new evacuation routes