Simulations predict that hot super-Earth sized exoplanets can have their envelopes stripped by photoevaporation, which would present itself as a lack of these exoplanets. However, this absence in the ...exoplanet population has escaped a firm detection. Here we demonstrate, using asteroseismology on a sample of exoplanets and exoplanet candidates observed during the Kepler mission that, while there is an abundance of super-Earth sized exoplanets with low incident fluxes, none are found with high incident fluxes. We do not find any exoplanets with radii between 2.2 and 3.8 Earth radii with incident flux above 650 times the incident flux on Earth. This gap in the population of exoplanets is explained by evaporation of volatile elements and thus supports the predictions. The confirmation of a hot-super-Earth desert caused by evaporation will add an important constraint on simulations of planetary systems, since they must be able to reproduce the dearth of close-in super-Earths.
Objective To examine whether high milk consumption is associated with mortality and fractures in women and men.Design Cohort studies.Setting Three counties in central Sweden.Participants Two large ...Swedish cohorts, one with 61 433 women (39-74 years at baseline 1987-90) and one with 45 339 men (45-79 years at baseline 1997), were administered food frequency questionnaires. The women responded to a second food frequency questionnaire in 1997.Main outcome measure Multivariable survival models were applied to determine the association between milk consumption and time to mortality or fracture.Results During a mean follow-up of 20.1 years, 15 541 women died and 17 252 had a fracture, of whom 4259 had a hip fracture. In the male cohort with a mean follow-up of 11.2 years, 10 112 men died and 5066 had a fracture, with 1166 hip fracture cases. In women the adjusted mortality hazard ratio for three or more glasses of milk a day compared with less than one glass a day was 1.93 (95% confidence interval 1.80 to 2.06). For every glass of milk, the adjusted hazard ratio of all cause mortality was 1.15 (1.13 to 1.17) in women and 1.03 (1.01 to 1.04) in men. For every glass of milk in women no reduction was observed in fracture risk with higher milk consumption for any fracture (1.02, 1.00 to 1.04) or for hip fracture (1.09, 1.05 to 1.13). The corresponding adjusted hazard ratios in men were 1.01 (0.99 to 1.03) and 1.03 (0.99 to 1.07). In subsamples of two additional cohorts, one in males and one in females, a positive association was seen between milk intake and both urine 8-iso-PGF2α (a biomarker of oxidative stress) and serum interleukin 6 (a main inflammatory biomarker).Conclusions High milk intake was associated with higher mortality in one cohort of women and in another cohort of men, and with higher fracture incidence in women. Given the observational study designs with the inherent possibility of residual confounding and reverse causation phenomena, a cautious interpretation of the results is recommended.
The representation of the atmospheric boundary layer is an important part of weather and climate models and impacts many applications such as air quality and wind energy. Over the years, the ...performance in modeling 2-m temperature and 10-m wind speed has improved but errors are still significant. This is in particular the case under clear skies and low wind speed conditions at night as well as during winter in stably stratified conditions over land and ice. In this paper, the authors review these issues and provide an overview of the current understanding and model performance. Results from weather forecast and climate models are used to illustrate the state of the art as well as findings and recommendations from three intercomparison studies held within the Global Energy and Water Exchanges (GEWEX) Atmospheric Boundary Layer Study (GABLS). Within GABLS, the focus has been on the examination of the representation of the stable boundary layer and the diurnal cycle over land in clear-sky conditions. For this purpose, single-column versions of weather and climate models have been compared with observations, research models, and large-eddy simulations. The intercomparison cases are based on observations taken in the Arctic, Kansas, and Cabauw in the Netherlands. From these studies, we find that even for the noncloudy boundary layer important parameterization challenges remain.
Treatment of sugarcane molasses distillery wastewater is challenging due to the presence of complex phenolic compounds (melanoidins and polyphenols) having antioxidant properties. Due to zero liquid ...discharge regulations, Indian distilleries continue to explore effective treatment options. This work examines the concentration of distillery wastewater by forward osmosis (FO) using aquaporin biomimetic membranes and magnesium chloride hexahydrate (MgCl2.6H2O) as draw solution. The operational parameters viz. feed solution and draw solution flow rate and draw solution concentration were optimized using 10% v/v melanoidins model feed solution. This was followed by trials with distillery wastewater. Under the conditions of this work, feed and draw flow rates of 1 L/min and draw solution concentration of 2M MgCl2.6H2O for melanoidins model solution and 3M MgCl2.6H2O for distillery wastewater were optimal for maximum rejection. Rejection of 90% melanoidins, 96% antioxidant activity and 84% COD was obtained with melanoidins model feed, with a corresponding water flux of 6.3 L/m2h. With as-received distillery wastewater, the rejection was similar (85–90%) to the melanoidins solution, but the water flux was lower (2.8 L/m2h). Water recovery from distillery wastewater over 24 h study period was higher with FO (70%) than reported for RO (35–45%). Repeated use of the FO membrane over five consecutive 24 h cycles with fresh feed and draw solutions and periodic cleaning showed consistent average water flux and rejection of the feed constituents.
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•Distillery wastewater and melanoidins solution were concentrated by forward osmosis.•Aquaporin biomimetic membranes and MgCl2.6H2O draw solution were used.•Rejection of organics, melanoidins and antioxidant activity was over 85%.•Water recovery of 70% was obtained with distillery wastewater feed.•Membrane performance was retained with periodic cleaning.
Along with temperature and density, the elemental abundance is a basic parameter required by astronomers to understand and model any physical system. The abundances of the solar corona are known to ...differ from those of the solar photosphere via a mechanism related to the first ionization potential of the element, but the normalization of these values with respect to hydrogen is challenging. Here, we show that the values used by solar physicists for over a decade and currently referred to as the "coronal abundances" do not agree with the data themselves. As a result, recent analysis and interpretation of solar data involving coronal abundances may need to be revised. We use observations from coronal spectroscopy, the solar wind, and solar energetic particles as well as the latest abundances of the solar photosphere to establish a new set of abundances that reflect our current understanding of the coronal plasma.
In the present work, combination of bi-metallic and tri-metallic Pt, Ir, Sn electro-catalysts was prepared by impregnation reduction method on carbon Vulcan XC-72 to improve upon electro-oxidation of ...ethanol in direct ethanol fuel cell. The prepared electro-catalysts were characterized by means of scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) analyses. XRD and TEM analyses reveal that the prepared catalysts are of nano size (6–10nm) range. It is shown that Pt lattice parameter decreases with the addition of Ir, and increases with the addition of Sn in Pt–Ir–Sn/C catalyst. The electro-catalytic activities characterized by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and chronoamperometry (CA) techniques reveal that the addition of small amount of Ir in Pt–Sn/C electro-catalyst exhibits higher activity towards ethanol oxidation than the Pt–Sn/C (20% Pt and 20% Sn by wt) electro-catalyst. The single direct ethanol fuel cell (DEFC) test at 90°C, 1bar with catalyst loading of 1mg/cm2 and 2M ethanol as anode feed showed an enhancement of catalytic activity in following order: Pt–Ir–Sn/C (20% Pt, 5% Ir and 15% Sn by wt)>Pt–Ir–Sn/C (20% Pt, 10% Ir and 10% Sn by wt)>Pt–Sn/C (20% Pt and 20% Sn by wt)>Pt–Ir–Sn/C (10% Pt, 15% Ir and 15% Sn by wt)>Pt–Ir/C (20% Pt and 20% Ir by wt)> Pt/C (40% Pt by wt). Pt–Ir–Sn/C (20% Pt, 5% Ir and 15% Sn by wt) exhibited highest performance among all the catalysts prepared with power density of 29mW/cm2 in DEFC operating at 90°C.
During translation initiation, initiation factor 2 (IF2) holds initiator transfer RNA (fMet-tRNA
) in a specific orientation in the peptidyl (P) site of the ribosome. Upon subunit joining IF2 ...hydrolyzes GTP and, concomitant with inorganic phosphate (P
) release, changes conformation facilitating fMet-tRNA
accommodation into the P site and transition of the 70 S ribosome initiation complex (70S-IC) to an elongation-competent ribosome. The mechanism by which IF2 separates from initiator tRNA at the end of translation initiation remains elusive. Here, we report cryo-electron microscopy (cryo-EM) structures of the 70S-IC from Pseudomonas aeruginosa bound to compact IF2-GDP and initiator tRNA. Relative to GTP-bound IF2, rotation of the switch 2 α-helix in the G-domain bound to GDP unlocks a cascade of large-domain movements in IF2 that propagate to the distal tRNA-binding domain C2. The C2-domain relocates 35 angstroms away from tRNA, explaining how IF2 makes way for fMet-tRNA
accommodation into the P site. Our findings provide the basis by which IF2 gates the ribosome to the elongation phase.
In this study, the effect of minor (5 vol.%) addition of Al–10Si–0.2Mg (composition in wt.%) pre-alloyed powder on densification, microstructure and mechanical behaviour of spark plasma-sintered ZrB
...2
-20 vol.% SiC composite has been investigated. The sintered composite records a relative density of 99.83% despite being processed at a relatively low temperature (1700 °C) in argon atmosphere. Interestingly, ZrB
2
–20SiC–5AlSiMg composite does not undergo any shape distortion though the liquidus temperature of this metallic alloy additive is quite low (~ 592 °C). Extensive phase and microstructure analyses by appropriate techniques indicate that no free or unreacted AlSiMg is detected in the sintered composite. Thermodynamic analysis suggests that AlSiMg serves as a reducing agent for ZrO
2
oxide scale and forms respective high-melting oxide phases. Raman analysis confirms that incorporation of 5 vol.% AlSiMg enhances residual compressive stress of SiC grains. Furthermore, the addition of AlSiMg is found to enhance the thermal shock resistance of the composite. In brief, this new AlSiMg additive results in better densification (99.83%) and hence an attractive combination of useful mechanical properties like Vickers microhardness (17.63 ± 0.54 GPa), nano-hardness (18.62 ± 1.23 GPa), indentation fracture toughness (7.21 ± 1.13 MPa
m
), elastic modulus (432.64 ± 32.90 GPa) and flexural strength (659.25 ± 32.40 MPa) in the AlSiMg-added ZrB
2
-20SiC composite.
The waste and recycling sector is a growing part of industry. Whether health surveillance is indicated and how it should be undertaken is unclear.
To undertake a review of the literature to identify ...hazards to health, biological effects and occupational illnesses for workers in the sector.
A systematic review of the published literature and two UK databases.
Rates of fatal, non-fatal injuries and self-reported work-related illness were found to be higher in the waste and recycling sector than in UK industry as a whole. There was an increased prevalence of respiratory, gastro-intestinal and skin complaints in workers exposed to compost relative to controls. They may also be at increased risk of extrinsic allergic alveolitis, allergic bronchopulmonary aspergillosis, occupational asthma and abnormalities of lung function. Workers involved with the recycling of batteries and cables may be at risk of lead poisoning and exposure to other heavy metals. There were case reports of mercury poisoning from the recycling of fluorescent lights. Cases of occupational asthma have been reported in association with wood and paper recycling. The recycling of e-waste may cause exposure to heavy metals and organic pollutants, such as polybrominated diphenyl ethers, dioxins and polyaromatic hydrocarbons, which have been associated with damage to DNA and adverse neonatal outcomes.
Ill-health and adverse biological effects have been described in waste and recycling workers, but their true prevalence has probably not been captured. Targeted health surveillance may be required to assess exposure and to identify occupational illness.
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