Effect of Martian Suspended Dust on Albedo Measurements from the MGS-TES Data

Suspended dust on Mars influences albedo measurements by orbiting instruments, but not necessary the real surface albedo. The aim of this study is to characterize the role of suspended aerosols on albedo measurement by remote sensing instruments

Frontal alpha asymmetry neurofeedback for the reduction of negative affect and anxiety

Frontal alpha asymmetry has been proposed to underlie the balance between approach and withdrawal motivation associated to each individual's affective style. Neurofeedback of EEG frontal alpha asymmetry represents a promising tool to reduce negative affect, although its specific effects on left/right frontal activity and approach/withdrawal motivation are still unclear. The present study employed a neurofeedback training to increase frontal alpha asymmetry (right - left), in order to evaluate discrete changes in alpha power at left and right sites, as well as in positive and negative affect, anxiety and depression. Thirty-two right-handed females were randomly assigned to receive either the neurofeedback on frontal alpha asymmetry, or an active control training (N = 16 in each group). The asymmetry group showed an increase in alpha asymmetry driven by higher alpha at the right site (p < 0.001), as well as a coherent reduction in both negative affect and anxiety symptoms (ps < 0.05), from pre-to post-training. No training-specific modulation emerged for positive affect and depressive symptoms. These findings provide a strong rationale for the use of frontal alpha asymmetry neurofeedback for the reduction of negative affect and anxiety in clinical settings

aluminum honeycomb sandwich for protective structures of earth moving machines

Abstract The design and the assembly of the vehicles subjected to the risk of crushing from falling objects have to consider such danger and provide the operators with suitable safety systems. Generally, falling object protective structures for earth moving machines consist of vertical elements, connected by transversal elements, covered by a roof. The latter has the aim to protect the operators from falling objects and it is usually made of a steel skeleton with a metal plate. In this study, sandwich panels were proposed as technical solution for the impact protection from falling objects in earth moving machines. A very light and cheap aluminum honeycomb core (AA3003 alloy and cell size = 19 mm) was considered as design solution and was subjected to static and dynamic full-scale tests. The results were analysed according to the performance requirements of ISO 3449 standard. The experimental results confirmed that the honeycomb structures are well suitable for designing absorber devices in vehicles protective structures in order to ensure occupant safety

Promoting the Flexibility of Thermal Prosumers Equipped with Heat Pumps to Support Power Grid Management

The increasing share of renewable energy sources in energy systems will lead to unpredictable moments of surplus/deficit in energy production. To address this issue, users with heat pumps can provide support to power grid operators through flexible unit operation achieved via Demand Response programs. For buildings connected to low-temperature heating networks with ensured third-party access, further room for flexibility can be explored by investigating the production of surplus heat that can be sold to the network. A key aspect lies in the identification of the energy pricing options that could encourage such flexible operation of a heat pump by “thermal prosumers”. To this aim, the present study investigates the impact of ad hoc variations in the electricity purchasing price through discounts or penalties included in the “network cost” component of the price on cost-effective operation of a heat pump connected to the thermal network. To discuss the effects of different pricing options in terms of increased flexibility, an office building located in Italy and equipped with a high-temperature heat pump is adopted as the case study. A heuristic profit-oriented management strategy of the heat pump is assumed, and dynamic simulations are performed. The results indicate that at current electricity prices, the heat pump operation is profitable both when supplying the heat to meet the building’s requirements and when producing surplus heat for sale to the thermal network. In addition, it is revealed that the penalties applied to the electricity purchasing price are effective in encouraging changes in the heat pump operation strategy, reducing its average production (the building increasingly relying on buying heat from the network) and the associated electricity consumption by 46.0% and 79.7% in the “light” and “severe” local power deficit scenarios, respectively

A General Process-Based Model for Describing the Metabolic Shift in Microbial Cell Cultures

The metabolic shift between respiration and fermentation at high glucose concentration is a widespread phenomenon in microbial world, and it is relevant for the biotechnological exploitation of microbial cell factories, affecting the achievement of high-cell-densities in bioreactors. Starting from a model already developed for the yeast Saccharomyces cerevisiae, based on the System Dynamics approach, a general process-based model for two prokaryotic species of biotechnological interest, such as Escherichia coli and Bacillus subtilis, is proposed. The model is based on the main assumption that glycolytic intermediates act as central catabolic hub regulating the shift between respiratory and fermentative pathways. Furthermore, the description of a mixed fermentation with secondary by-products, characteristic of bacterial metabolism, is explicitly considered. The model also represents the inhibitory effect on growth and metabolism of self-produced toxic compounds relevant in assessing the late phases of high-cell density culture. Model simulations reproduced data from experiments reported in the literature with different strains of non-recombinant and recombinant E. coli and B. subtilis cultured in both batch and fed-batch reactors. The proposed model, based on simple biological assumptions, is able to describe the main dynamics of two microbial species of relevant biotechnological interest. It demonstrates that a reductionist System Dynamics approach to formulate simplified macro-kinetic models can provide a robust representation of cell growth and accumulation in the medium of fermentation by-products

New fluorescent polymeric nanocomposites synthesized by antimony dodecyl-mercaptide thermolysis in polymer

In this work, the formation of semiconductive Sb2S3 nanoparticles inside amorphous polystyrene has been achieved by thermal degradation of the corresponding antimony dodecyl-mercaptide, Sb(SC12H25)3. The thermolysis of the dodecyl-mercaptide precursor was studied as both pure phase and mercaptide solution in polystyrene. The thermal decom- position of the antimony mercaptide precursor at 350°C, under vacuum, showed the formation of a mixture of antimony trisulfide (stibnite, Sb2S3) and zero-valent antimony (Sb) phase. X-ray Powder Diffraction (XRD) and Rietveld analysis carried out on the obtained nanostructured powder confirmed the presence of Sb and Sb2S3 phases in 10.4 wt% and 89.6 wt% amount, respectively. The same pyrolysis reaction was carried out in the polymer and the resulting nanocompos- ite material was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-VIS spec- troscopy, and fluorescence spectroscopy. The nanocomposite structural characterization indicated the presence of well-dispersed nanoclusters of antimony and stibnite (15-30 nm in size) inside the amorphous polymeric phase. Optical measurements on the obtained nanocomposite films showed a strong emission at 432 nm upon excitation at 371 nm, prob- ably related to the presence of Sb2S3 nanoclusters

Spectrophotometric properties of dwarf planet Ceres from the VIR spectrometer on board the Dawn mission

We study the spectrophotometric properties of dwarf planet Ceres in the VIS-IR spectral range by means of hyper-spectral images acquired by the VIR imaging spectrometer on board the NASA Dawn mission. Disk-resolved observations with a phase angle within the $7^{\circ}<\alpha<132^{\circ}$ interval were used to characterize Ceres' phase curve in the 0.465-4.05 $\mu$m spectral range. Hapke's model was applied to perform the photometric correction of the dataset, allowing us to produce albedo and color maps of the surface. The $V$-band magnitude phase function of Ceres was fitted with both the classical linear model and H-G formalism. The single-scattering albedo and the asymmetry parameter at 0.55$\mu$m are $w=0.14\pm0.02$ and $\xi=-0.11\pm0.08$, respectively (two-lobe Henyey-Greenstein phase function); the modeled geometric albedo is $0.094\pm0.007$; the roughness parameter is $\bar{\theta}=29^{\circ}\pm6^{\circ}$. Albedo maps indicate small variability on a global scale with an average reflectance of $0.034 \pm 0.003$. Isolated areas such as the Occator bright spots, Haulani, and Oxo show an albedo much higher than average. We measure a significant spectral phase reddening, and the average spectral slope of Ceres' surface after photometric correction is $1.1\%k\AA^{-1}$ and $0.85\%k\AA^{-1}$ at VIS and IR wavelengths, respectively. Broadband color indices are $V-R=0.38\pm0.01$ and $R-I=0.33\pm0.02$. H-G modeling of the $V$-band magnitude phase curve for $\alpha<30^{\circ}$ gives $H=3.14\pm0.04$ and $G=0.10\pm0.04$, while the classical linear model provides $V(1,1,0^{\circ})=3.48\pm0.03$ and $\beta=0.036\pm0.002$. The comparison with spectrophotometric properties of other minor bodies indicates that Ceres has a less back-scattering phase function and a slightly higher albedo than comets and C-type objects. However, the latter represents the closest match in the usual asteroid taxonomy.Comment: 14 pages, 20 figures, published online on Astronomy and Astrophysics on 13 February 2017. Revised to reflect minor changes in text and figures made in proofs, updated value of V-R and R-