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Species color and color pattern vary geographically contributing to environmental tolerance of the species to the fluctuating climate. In a constantly changing environment, the population remains polymorphic, when individuals that are not acclimated to the current environment can survive adverse time periods. Factors influencing color morph frequencies in populations affect spatial variation through local adaptation, which is in turn linked to large‐scale environmental gradients. The influence of environmental factors has not been adequately studied in many polymorphic organisms where the influence of sexual selection on the persistence of polymorphisms is widely recognized. We hypothesized that different color morphs of sand lizard are distributed throughout the Palearctic depending on different environmental conditions. The goal of this study was to examine if the range of morph composition in a color polymorphic lizard can be explained by geographic and climatic variation in the Palearctic. We used publicly available data on sand lizard occurrence from the Global Biodiversity Information Facility and environmental variables from WorldClim and SEDAC databases. We categorized sand lizards' photos to 10 discrete color morphs based on color and color pattern variation. We predicted the color morph distribution using maximum entropy models. We found that variations in morph distributions were mostly related to temperature seasonality, precipitation, elevation, and anthropogenic activities. Our findings support the relationship between environmental conditions and color morph distribution, implying that environmental selection acts differently on color morphs, most likely in conjunction with sexual selection. [ABSTRACT FROM AUTHOR]

We report an interesting Equatorial Plasma Bubbles (EPBs) event during the night of March 22–23, 2017. To investigate the dynamics of observed EPBs, we utilize multi‐instrument data obtained with all‐sky imager (ASI) from Panhala (16.48°N, 74.6°E, 11.1°N Dip. Lat.), Canadian Advanced Digital Ionosonde (CADI) from Tirunelveli (8.73°N, 77.7°E, 1.6°N Dip. Lat.) and ionospheric backscatter echoes data of Gadanki Ionospheric Radar Interferometer (GIRI) radar from Gadanki (13.5°N, 79.2°E, 6.5°N Dip. Lat.) over Indian regions. The optical observations from Panhala reveal clear signatures of EPBs from ∼1600 UT onwards and corresponding ESF occurrence is noted in CADI at Tirunelveli as well. Backscatter echoes are also recorded in Range time intensity map obtained by GIRI after ∼17:45 UT. On this night, two EPBs (EPB1 and EPB2) are observed with inter‐depletion distance of ∼600 km. The EPB1 drifts eastward throughout the night and evolves with time as bifurcated structures while the trailing EPB2 drifts eastward initially and eventually drifts westward. We believe that this is the first evidence of differential drifts of EPBs imaged through ASI over a narrow longitudinal zone over the Indian region. Key Points: One Equatorial Plasma Bubble (EPB) moves eastward while trailing EPB moves westward indicating unusual bidirectional drift patternLarge eastward drift values toward dip equatorial region as compared to low latitude regionThe diminishing of EPBs is observed due to interaction with enhanced intensity region [ABSTRACT FROM AUTHOR]

When designing a concentrating solar power (CSP) system, selection of a proper heat transfer fluid (HTF) material is a key, especially when employed in parabolic trough CSP plants. In particular, the use of low melting mixtures as an alternative to the widely commonly used "solar salt" can increase the CSP manageably and, as a result, several innovative nitrite/nitrate mixtures have been proposed. However, very few thermodynamics data are available for these compounds, especially regarding ternary compositions. One of the most interesting low freezing mixture is prepared with sodium and potassium nitrate together with sodium nitrite. The aim of this work is to investigate the thermodynamics properties of this ternary system, starting from its binary subunits, studying the phase diagram of this compound both experimentally and by a regular solution model. At this purpose, the literature phase diagrams of the binary subsystem were simulated in order to obtain the fitting parameters necessary for the employed semi-predictive tool. Then, the ternary system was modeled and the results showed very good agreement with the experimental points. It is quite interesting to note that both the theoretical and experimental results showed a low melting zone presenting greater sodium nitrate molar fractions with respect to sodium nitrite than previously reported in literature. This would lead to a decrease in the HTF price and an improvement regarding the fluid toxicity. [ABSTRACT FROM AUTHOR]

The employment of parabolic trough solar power plants (PT-CSP) for electrical power and process heat generation is one of the most promising technologies for carbon free energy production. The selection of thermal fluids, both for the heat transfer (heat transfer fluid, HTF) and the storage (heat storage material, HSM), is a crucial point for increasing CSP efficiency and cost effectiveness. In this paper two different PT-CSP configurations, both presenting a double tanks storage system, are compared. In particular, two different medium size (50 MWe) plant schemes, presenting two different working fluids as HTF, are described and analysed. In the first scheme a “binary” molten salt mixture, composed of sodium and potassium nitrate, is considered, while, in the second one, the employment, as HTF, of a “ternary” mixture, consisting of sodium potassium and lithium nitrates, is investigated. In both cases, the binary mixture is used for thermal storage (HSM). The first scheme represents the configuration developed by ENEA and already used for the Archimede plant in Priolo Gargallo (Sicily-Italy). The second one is an innovative proposal, which aims to improve CSP plants performances and to reduce operating costs. In particular, since the ternary mixture has a considerably lower freezing temperature than the binary one, this solution allows to keep the system at a lower temperature overnight, so reducing thermal energy losses. In first instance, it is necessary to characterize the binary and ternary mixtures respect to their thermo-physical features. The two CSP configurations are then sized and, by a techno/economic evaluation, compared with respect to the calculated unit cost of electricity production. [ABSTRACT FROM AUTHOR]

To reveal how the AT-rich genome of bacteriophage PhiKZ has been shaped in order to carry out its growth in the GC-rich host Pseudomonas aeruginosa, synonymous codon and amino acid usage bias of PhiKZ was investigated and the data were compared with that of P. aeruginosa. It was found that synonymous codon and amino acid usage of PhiKZ was distinct from that of P. aeruginosa. In contrast to P. aeruginosa, the third codon position of the synonymous codons of PhiKZ carries mostly A or T base; codon usage bias in PhiKZ is dictated mainly by mutational bias and, to a lesser extent, by translational selection. A cluster analysis of the relative synonymous codon usage values of 16 myoviruses including PhiKZ shows that PhiKZ is evolutionary much closer to Escherichia coli phage T4. Further analysis reveals that the three factors of mean molecular weight, aromaticity and cysteine content are mostly responsible for the variation of amino acid usage in PhiKZ proteins, whereas amino acid usage of P. aeruginosa proteins is mainly governed by grand average of hydropathicity, aromaticity and cysteine content. Based on these observations, we suggest that codons of the phage-like PhiKZ have evolved to preferentially incorporate the smaller amino acid residues into their proteins during translation, thereby economizing the cost of its development in GC-rich P. aeruginosa. [ABSTRACT FROM AUTHOR]

Abstract: To reveal the factors influencing architecture of protein-coding genes in staphylococcal phages, relative synonymous codon usage variation has been investigated in 920 protein-coding genes of 16 staphylococcal phages. As expected for AT rich genomes, there are predominantly A and T ending codons in all 16 phages. Both N c plot and correspondence analysis on relative synonymous codon usage indicates that mutation bias influences codon usage variation in the 16 phages. Correspondence analysis also suggests that translational selection and gene length also influence the codon usage variation in the phages to some extent and codon usage in staphylococcal phages is phage-specific but not S. aureus-specific. Further analysis indicates that among 16 staphylococcal phages, 44AHJD, P68 and K may be extremely virulent in nature as most of their genes have high translation efficiency. If this is true, then above three phages may be useful for curing staphylococcal infections. [Copyright &y& Elsevier]

Abstract: We report about the synthesis and characterisation of two NiCeZrO2 catalysts prepared by one pot-co-precipitation method. The two samples are characterised by similar chemical composition (15wt% Ni, Ce/Zr=80/20 atomic ratio) and properties of the CeZrO2 support, which is a cubic phase solid solution with nanometer sized (5–6nm) crystalline hexagonal/roundish particles. The main differences between the samples are in the NiO particles dispersion and surface area, which were found to be affected by the synthesis pH. Both samples were characterised about their surface properties by employing FTIR spectroscopy of adsorbed CO probe, and tested about their activity and stability in methane steam reforming (MSR) reaction at relatively low temperature (793K). The results show a good activity in MSR irrespective of the NiO size and morphology, with negligible CO formation, but a strong dependence of the catalysts stability upon these parameters. Only the catalyst with smaller (5–10nm) NiO particles was found stable for 250h in MSR at relatively high steam to carbon ratio (S/C=2). This performance could be related to a positive effect of the CeZrO2 support, allowing fast and easy oxygen transfer to and from the NiO/Ni0 active phase, most likely thanks to the occurrence of a strong metal–support interaction. [Copyright &y& Elsevier]

Abstract: Iodine excess separation from hydriodic acid (HI) is one of the most challenging steps of the Sulfur–Iodine thermochemical water splitting cycle. One promising method is the extraction of HI by using phosphoric acid (H3PO4), with the subsequent separation of gaseous hydriodic acid from water and H3PO4 by a distillation step. The aim of the present work is to provide new experimental liquid–liquid equilibrium data for the biphasic HI/I2/H2O/H3PO4 quaternary system, varying both temperature and solution composition in order to optimize the excess of anhydrous phosphoric acid to be added. Two temperature levels were tested, i.e. 100°C and 120°C, and the H3PO4 amount was varied in the feed mixture from 7.7% wt to 38% wt while the [I2]/[HI] and [H2O]/[HI] molar ratios were kept constant at, respectively, a value of 3.7 and 5.6. A temperature level of 120°C, with an H3PO4 initial concentration of about 29% wt leads to the lowest amount of water against HI, which minimizes energy costs in the phosphoric acid reconcentration step, the most energy consuming part in this separation process. [Copyright &y& Elsevier]

Abstract: The gaseous hydrogen iodide decomposition is a thermodynamically limited reaction and subsequently a considerable energy expense for the separation and recirculation of the unreacted species is required. In addition the homogeneous gas phase decomposition of hydrogen iodide has a very low rate and the use of a catalytic system, which is generally highly expensive, is necessary. Hence, with the aim of overcoming the bottleneck represented by the hydrogen releasing step of the Sulphur–Iodine (S–I) cycle in terms of costs and process efficiency, in the present work an alternative version of the HI decomposition section (HI x section) is proposed. In that alternative configuration the addition of metallic nickel into the heavy phase coming from Bunsen reaction is conceived in order to quantitatively obtain hydrogen at low temperature. A theoretical and experimental investigation has been performed, a new cycle has been conceived and the resulting energy demand assessed. [Copyright &y& Elsevier]

Abstract: The decomposition of gaseous sulfuric acid has been investigated computationally. In particular the role of the hydrated gaseous coordination adducts of SO3(g) and H2SO4(g) in the (dissociation+decomposition) process has been evaluated. A first principles study of the gaseous coordination complexes SO3(H2O) n (n =1 to 3) and H2SO4(H2O) m (m =1 to 2) has been carried out deriving equilibrium ground state structures, vibrational frequencies and energetic stabilities by the Moller–Plesset perturbation approximation. These results have been used to derive the enthalpy of formation at 0K and the Gibbs energy functions of these molecules. A new thermodynamic modeling of the decomposition of H2SO4(g) has been therefore performed considering the effect of temperature, pressure and initial composition of the gas (hydration conditions). [Copyright &y& Elsevier]