A novel experimental method for the measurement of the caloric curves of clusters

A novel experimental scheme has been developed in order to measure the heat capacity of mass selected clusters. It is based on controlled sticking of atoms on clusters. This allows one to construct the caloric curve, thus determining the melting temperature and the latent heat of fusion in the case of first-order phase transitions. This method is model-free. It is transferable to many systems since the energy is brought to clusters through sticking collisions. As an example, it has been applied to Na\_90\^+ and Na\_140\^+. Our results are in good agreement with previous measurements

First-Principles Calculation of the Cu-Li Phase Diagram

We present first-principles calculations of the solid-state portion of the Cu-Li phase diagram based on the cluster expansion formalism coupled with the use of (i) bond length-dependent transferable force constants and lattice dynamics calculations to model of vibrational disorder and (ii) lattice gas Monte Carlo simulations to model configurational disorder. These calculations help settle the existence of additional phases in the Cu-Li phase diagram that have been postulated, but not yet clearly established. Our calculations predict the presence of at least one additional phase and the associated predicted phase transitions are consistent with our electrochemical measurements, which exhibit clear plateaus in the electromotive force-composition curve

The use of gliders for oceanographic science: the data processing gap

Autonomous gliders represent a step change in the way oceanographic data can be collected and as such they are increasingly seen as valuable tools in the oceanographer’s arsenal. However, their increase in use has left a gap regarding the conversion of the signals that their sensors collect into scientifically useable data.At present the novelty of gliders means that only a few research groups within the UK are capable of processing glider data whilst the wider oceanographic community is often unaware that requesting deployment of a glider by MARS does not mean that they will be provided with fully processed and calibrated data following the deployment. This is not a failing of MARS – it is not in their remit – but it does mean that a solution is needed at the UK community level. The solution is also needed quickly given the rapidly growing glider fleet and requests to use it.To illustrate the far from trivial resources and issues needed to solve this problem at a community level, this document briefly summarises the resources and steps involved in carrying glider data through from collection to final product, for the glider owning research groups within the UK which have the capability.This report does not provide a recommendation on whether such a community facility should be the responsibility of NOC, BODC or MARS but does provide information on possible protocols and available software that could be part of a solution.This report does, however, recommend that, to support the growing use of the MARS gliders, a permanently staffed group is needed as a priority, to provide data processing and calibration necessary to allow the translation of glider missions into high impact scientific publications

Testing the predective validity of the time trade-off and the Stardard Gamble

This paper tests the consistency of health utility measurements with individual preferences. We compare three methods, the time trade-off, the standard gamble and a version of the standard gamble that corrects for the deviations from expected utility modelled by prospect theory. Individual preferences are measured both through a ranking task and through a choice task. In decisions involving no risk the time trade-off is most consistent with people’s preferences with the standard gamble a close second. In decisions involving risk the corrected standard gamble is most consistent with people’s preferences. Our data do not support the common assumption in health economics that utility is transferable across decision contexts.Health utility measurement, QALYs,stardard gamble, time trade-off, prospect theory.

Energy use and indoor environment in a sample of monitored domestic buildings in the UK

This paper is based on the low-cost approaches and transferable techniques that were applied in a PhD reserch project on energy-related occupancy activities. The strengths of qualitative and quantitative research strategies were combined for the study of this socio-technical research topic. Long-term field measurement was conducted for data acquisition using self-configured monitoring schemes. Case study was selected as the research approach. Building characteristics and household features in each case study group were purposefully selected to deploy same-standard monitoring schemes. Comparable monitoring results were pre-processed following identical procedures to implement the selected data analysis methods. The inspection results provided the researcher and the associated project partners with a novel perspective to interpret the difference in actual energy consumption and indoor environment within and between the case study groups. The research methodology and moitoring approach are covered in this paper that also presents the macro-scale monitoring results of energy use and indoor environment in two case study groups. The micro-scale presentation and algorithm-based examination will be covered in other academic papers. This paper demonstrates the huge potential for some commonly applied building assessment methods to be improved by objectively considering currently overlooked aspects, such as the low-tech design and construction of heavy-weight thermal mass houses and the largely varied occupancy activities. Future work relating to the comparison of actual monitoring data with simulation results is pointed out at the end of the paper

Using the right slope of the 970 nm absorption feature for estimating canopy water content

Canopy water content (CWC) is important for understanding the functioning of terrestrial ecosystems. Biogeochemical processes like photosynthesis, transpiration and net primary production are related to foliar water. The first derivative of the reflectance spectrum at wavelengths corresponding to the left slope of the minor water absorption band at 970 nm was found to be highly correlated with CWC and PROSAIL model simulations showed that it was insensitive to differences in leaf and canopy structure, soil background and illumination and observation geometry. However, these wavelengths are also located close to the water vapour absorption band at about 940 nm. In order to avoid interference with absorption by atmospheric water vapour, the potential of estimating CWC using the first derivative at the right slope of the 970 nm absorption feature was studied. Measurements obtained with an ASD FieldSpec spectrometer for three test sites were related to CWC (calculated as the difference between fresh and dry weight). The first site was a homogeneous grassland parcel with a grass/clover mixture. The second site was a heterogeneous floodplain with natural vegetation like grasses and various shrubs. The third site was an extensively grazed fen meadow. Results for all three test sites showed that the first derivative of the reflectance spectrum at the right slope of the 970 nm absorption feature was linearly correlated with CWC. Correlations were a bit lower than those at the left slope (at 942.5 nm) as shown in previous studies, but better than those obtained with water band indices. FieldSpec measurements showed that one may use any derivative around the middle of the right slope within the interval between 1015 nm and 1050 nm. We calculated the average derivative at this interval. The first site with grassland yielded an R2 of 0.39 for the derivative at the previously mentioned interval with CWC (based on 20 samples). The second site at the heterogeneous floodplain yielded an R2 of 0.45 for this derivative with CWC (based on 14 samples). Finally, the third site with the fen meadow yielded an R2 of 0.68 for this derivative with CWC (based on 40 samples). Regression lines between the derivative at the right slope of the 970 nm absorption feature and CWC for all three test sites were similar although vegetation types were quite different. This indicates that results may be transferable to other vegetation types and other site

Fast Damage Recovery in Robotics with the T-Resilience Algorithm

Damage recovery is critical for autonomous robots that need to operate for a long time without assistance. Most current methods are complex and costly because they require anticipating each potential damage in order to have a contingency plan ready. As an alternative, we introduce the T-resilience algorithm, a new algorithm that allows robots to quickly and autonomously discover compensatory behaviors in unanticipated situations. This algorithm equips the robot with a self-model and discovers new behaviors by learning to avoid those that perform differently in the self-model and in reality. Our algorithm thus does not identify the damaged parts but it implicitly searches for efficient behaviors that do not use them. We evaluate the T-Resilience algorithm on a hexapod robot that needs to adapt to leg removal, broken legs and motor failures; we compare it to stochastic local search, policy gradient and the self-modeling algorithm proposed by Bongard et al. The behavior of the robot is assessed on-board thanks to a RGB-D sensor and a SLAM algorithm. Using only 25 tests on the robot and an overall running time of 20 minutes, T-Resilience consistently leads to substantially better results than the other approaches

Collective dynamics in crystalline polymorphs of ZnCl2_{2}: potential modelling and inelastic neutron scattering study

We report a phonon density of states measurement of $\alpha$-ZnCl$_{2}$ using the coherent inelastic neutron scattering technique and a lattice dynamical calculation in four crystalline phases of ZnCl$_{2}$ using a transferable interatomic potential. The model calculations agree reasonably well with the available experimental data on the structures, specific heat, Raman frequencies and their pressure variation in various crystalline phases. The calculated results have been able to provide a fair description of the vibrational as well as the thermodynamic properties of ZnCl$_{2}$ in all its four phases.Comment: Accepted in J. Phys.: Condens. Matte