Commercial carbon composition resistors have been used as gauges to make dynamic stress measurements in homogeneous and heterogeneous reactive and inert materials. Initial loading was provided by plane wave lenses or shaped charge jets. A series of gas gun and aquarium experiments has been conducted to characterize the behavior of the gauges. Calibrations up to about 14 GPa for nominal 470 Ω resistors and 17 GPa for nominal 4700 Ω resistors are presented. The accuracy of the carbon resistor gauges is limited by response time considerations when submicrosecond rise times are encountered, and there is hysteresis during release. The gauge-to-gauge reproducibility appears to be adequate, and they survive in situations where no other stress transducer has been successfully used, such as in reacting beds of large-particle gun propellants.

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Ytterbium has been successfully used as the piezoresistive element in stress transducers for in situ measurements of stress amplitudes associated with wave propagation in rocks and soils and for laboratory studies of high-rate loading effects in solids and liquids. Ytterbium has been calibrated over its useful range and it can be seen that consideration of the tensor aspects of the piezoresistance become important below 10 kbar. We have used static tensile and hydrostatic data to determine the piezoresistivity tensor coefficients and estimate the shock-wave piezoresistance coefficient, which compares well with experiment. In addition, we offer an explanation of the difference observed between hydrostatic and shock-wave data in the region where plastic deformation becomes important during dynamic compression.

Solar electricity enables the advancement and deployment of technologies that are strongly influenced by clean energy availability and cost. The economics of both desalination and hydrogen production from water electrolysis are dominated by the cost of energy, and the availability of inexpensive solar energy creates markets and offers incentives to the desalination and electrolyzer industries. Herein, production of high‐purity water and hydrogen from seawater is focused on. Current electrolyzers require deionized water so they need to be coupled with desalination units. It is shown that such coupling is cost effective in hydrogen generation, and it also offers benefits to thermal desalination, which can utilize waste heat from electrolysis. Furthermore, such coupling can be optimized when electrolyzers operate at high current density, using low‐cost solar and/or wind electricity, as such operation increases both hydrogen production and heat generation. Results of technoeconomic modeling of polymer electrolyte membrane electrolyzers define thresholds of electricity pricing, current density, and operating temperature that make clean electrolytic hydrogen cost competitive with hydrogen from steam methane reforming (SMR). By using 2020 hourly electricity pricing in California and Texas, it is estimated that hydrogen can be produced from seawater in coupled desalination−electrolyzer systems at prices near $2 kg−1 H2, reaching cost parity with hydrogen produced from SMR.