Extreme temperatures, mortality, and adaptation: Evidence from the county level in China.

Extreme temperatures are known to cause adverse health outcomes. Yet knowledge on the magnitude of this effect in developing countries is limited due to data availability and reliability issues. Collecting data for 2872 counties in China, we estimate the effects of daily temperatures on the monthly mortality rate. The results indicate that an additional day for which the maximum temperature is 38°C or above on average increases the monthly mortality rate by about 1.7% relative to if that day's maximum temperature had been in the range 16-21°C. This is after deducting deaths harvested from the subsequent month. Higher gross domestic product per capita at the county level is associated with lower mortality effects of hot and cold days. Improved dwelling conditions are found to be associated with a lower mortality effect of hot days and improved local healthcare infrastructure to be associated with a lower mortality effect of cold days. In the absence of strong adaptation efforts, the estimates suggest net upward pressure on annual mortality rates over coming decades in many populous counties, especially under more extreme climate change scenarios.

Lithium-antimony-lead liquid metal battery for grid-level energy storage.

The ability to store energy on the electric grid would greatly improve its efficiency and reliability while enabling the integration of intermittent renewable energy technologies (such as wind and solar) into baseload supply. Batteries have long been considered strong candidate solutions owing to their small spatial footprint, mechanical simplicity and flexibility in siting. However, the barrier to widespread adoption of batteries is their high cost. Here we describe a lithium-antimony-lead liquid metal battery that potentially meets the performance specifications for stationary energy storage applications. This Li||Sb-Pb battery comprises a liquid lithium negative electrode, a molten salt electrolyte, and a liquid antimony-lead alloy positive electrode, which self-segregate by density into three distinct layers owing to the immiscibility of the contiguous salt and metal phases. The all-liquid construction confers the advantages of higher current density, longer cycle life and simpler manufacturing of large-scale storage systems (because no membranes or separators are involved) relative to those of conventional batteries. At charge-discharge current densities of 275 milliamperes per square centimetre, the cells cycled at 450 degrees Celsius with 98 per cent Coulombic efficiency and 73 per cent round-trip energy efficiency. To provide evidence of their high power capability, the cells were discharged and charged at current densities as high as 1,000 milliamperes per square centimetre. Measured capacity loss after operation for 1,800 hours (more than 450 charge-discharge cycles at 100 per cent depth of discharge) projects retention of over 85 per cent of initial capacity after ten years of daily cycling. Our results demonstrate that alloying a high-melting-point, high-voltage metal (antimony) with a low-melting-point, low-cost metal (lead) advantageously decreases the operating temperature while maintaining a high cell voltage. Apart from the fact that this finding puts us on a desirable cost trajectory, this approach may well be more broadly applicable to other battery chemistries.

Fuel prices and road deaths: Motorcyclists are different.

This study estimates the effect of gasoline prices on road deaths by vehicle mode using annual data for 62 countries for 2000-2018 and all states of the United States (US) for 1998-2018. Higher gasoline prices are associated with fewer overall road deaths. The proportional effect on motorcyclist deaths tends to be smaller or even have the opposite sign, especially in countries that are not highly dependent on motorcycles. For the US, a positive effect of gasoline prices on motorcyclist deaths is found, with an elasticity of about 0.3. There is also a positive relationship between gasoline prices and motorcycle registrations in the US. The results confirm that additional attention towards motorcyclist safety is warranted in times of high fuel prices.

X-ray photoelectron spectroscopy (XPS) investigation of the surface film on magnesium powders.

Magnesium (Mg) and its alloys are attractive for use in automotive and aerospace applications because of their low density and good mechanical properties. However, difficulty in forming magnesium and the limited number of available commercial alloys limit their use. Powder metallurgy may be a suitable solution for forming near-net-shape parts. However, sintering pure magnesium presents difficulties due to surface film that forms on the magnesium powder particles. The present work investigates the composition of the surface film that forms on the surface of pure magnesium powders exposed to atmospheric conditions and on pure magnesium powders after compaction under uniaxial pressing at a pressure of 500 MPa and sintering under argon at 600 °C for 40 minutes. Initially, focused ion beam microscopy was utilized to determine the thickness of the surface layer of the magnesium powder and found it to be ~10 nm. The X-ray photoelectron analysis of the green magnesium sample prior to sintering confirmed the presence of MgO, MgCO(3)·3H(2)O, and Mg(OH)(2) in the surface layer of the powder with a core of pure magnesium. The outer portion of the surface layer was found to contain MgCO(3)·3H(2)O and Mg(OH)(2), while the inner portion of the layer is primarily MgO. After sintering, the MgCO(3)·3H(2)O was found to be almost completely absent, and the amount of Mg(OH)(2) was also decreased significantly. This is postulated to occur by decomposition of the compounds to MgO and gases during the high temperature of sintering. An increase in the MgO content after sintering supports this theory.