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Mesoscale imperfections, such as pores and voids, can strongly modify the properties and the mechanical response of materials under extreme conditions. Tracking the material response and microstructure evolution during void collapse is crucial for understanding its performance. In particular, imperfections in the ablator materials, such as voids, can limit the efficiency of the fusion reaction and ultimately hinder ignition. To characterize how voids influence the response of materials during dynamic loading and seed hydrodynamic instabilities, we have developed a tailored fabrication procedure for designer targets with voids at specific locations. Our procedure uses SU-8 as a proxy for the ablator materials and hollow silica microspheres as a proxy for voids and pores. By using photolithography to design the targets’ geometry, we demonstrate precise and highly reproducible placement of a single void within the sample, which is key for a detailed understanding of its behavior under shock compression. This fabrication technique will benefit high-repetition rate experiments at x-ray and laser facilities. Insight from shock compression experiments will provide benchmarks for the next generation of microphysics modeling.

Many questions regarding dynamic materials could be answered by using time-resolved ultra-fast imaging techniques to characterize the physical and chemical behavior of materials in extreme conditions and their evolution on the nanosecond scale. In this work, we perform multi-frame phase-contrast imaging (PCI) of micro-voids in low density polymers under laser-driven shock compression. At the Matter in Extreme Conditions (MEC) Instrument at the Linac Coherent Light Source (LCLS), we used a train of four x-ray free electron laser (XFEL) pulses to probe the evolution of the samples. To visualize the void and shock wave interaction, we deployed the Icarus V2 detector to record up to four XFEL pulses, separated by 1-3 nanoseconds. In this work, we image elastic waves interacting with the micro-voids at a pressure of several GPa. Monitoring how the material’s heterogeneities, like micro-voids, dictate its response to a compressive wave is important for benchmarking the performances of inertial confinement fusion energy materials. For the first time in a single sample, we have combined an ultrafast x-ray framing camera and four XFEL pulse train to create an ultrafast movie of micro-void evolution under laser-driven shock compression. Eventually, we hope this technique will resolve the material density as it evolves dynamically under laser shock compression.

We measure polarization-resolved fundamental, second, and third harmonic nonlinear Thomson scattering out the side of a laser focus with ${10}^{18}\phantom{\rule{0.16em}{0ex}}\mathrm{W}/{\mathrm{cm}}^{2}$. The separate measured polarization components are each associated with a distinct dimension of predicted electron figure-8 motion. Taken together, the measured angular emission patterns for the two polarizations unambiguously confirm the figure-8 motion. Electrons are donated from low-density helium (${10}^{\ensuremath{-}3}$ to 1 Torr) ionized early during the laser pulse. Time-resolved single-photon detection is used to distinguish signal from noise.

We measure fundamental, second, and third harmonics of nonlinear Thomson scattering emitted by free electrons out the side of a laser focus with 1018 W/cnf. The redshifted photons show distinct spatial patterns when resolved by polarization.

Bioeconomy is an emerging concept that is gaining momentum both in science and policy. Within the forest sector, the bioeconomy discourse is already shaping the international forest policy debate. Given the sector's importance for the national economy, this study investigates the perceptions of bioeconomy by forest owners, forest industry and ENGOs in Sweden. Drawing on cognitive and ideological dimensions of political bargaining, we analyse to which extent the bioeconomy serves as a bridging concept, a dividing concept or a boundary object. The results show that the bioeconomy is a broadly accepted concept, perceived as a natural extension of the Swedish forestry model. Results indicate that bioeconomy is well aligned with the key characteristics of a boundary object, that is, serving specific interests of different forest stakeholders under the generally accepted conceptual umbrella. We did not identify dividing effects of any substance. On the contrary, the interviews provide a strong indication that bioeconomy serves the Swedish forest sector as a bridging concept that brings closer rather than antagonises the different actors.

The purpose of this study was to determine the time course of the attenuation in sympathetic nervous activity during active heat acclimation (HA) in healthy humans. Eight volunteers completed a maximal graded exercise test followed by 8 days of active HA. Heat acclimation consisted of 90 min of walking at 40% of maximal oxygen uptake in a heated environmental chamber at 35 °C. The mean (± SD) ending core temperature during exercise was significantly reduced during the 8 days of HA. Specifically, it decreased from 38.3 ± 0.4 °C on day 1 to 37.9 ± 0.3 °C on day 8. In addition, ending HR during exercise was also significantly reduced from 152 ± 18 bpm on day 1 to 135 ± 15 bpm on day 8 of HA. The most important new finding was that plasma norepinephrine concentration following the first day of exercise in the heat was 1.58 ± 0.22 ng/ml. It significantly decreased to 1.01 ± 0.20, 0.98 ± 0.15, and 0.89 ± 0.11 on days 3, 5, and 8, respectively. The results of the current study show that active HA causes a rapid and significant reduction in NE during exercise in the heat. Such a result suggests that SNA was likewise reduced during HA and may be partially responsible for the reductions in HR that occur with HA since end-exercise HR and NE were found to be highly correlated (r = 0.79).

A frequently heard argument for new highways, especially those to be located in rural regions, is that they will directly lead to new business attraction and expansion opportunities (i.e., expanding from a two-lane road to a four-lane expressway will be what is needed to jump-start lagging economic regions). The literature on industrial site location commonly cites transportation infrastructure and access to markets as key determinants of business location. Meanwhile, many prospective studies are undertaken (major investments studies, environmental impact statements, etc.) that include analyses to try to estimate the economic impacts of new highway investments. The problem is that most transportation-based analysis tools, such as travel network and user benefit models, are not designed to answer the question of the potential for a highway investment to lead to business attraction (which is inherently speculative). Rather, they focus on quantifying current and future traffic patterns and how they will be affected by a highway improvement. The North Country Transportation Study examined these traditional benefits but also, perhaps more importantly, carefully studied the potential for business attraction to the region. This effort provides a substantial advance in the economic development analysis of transportation investments because of the thoroughness of sources and methodologies undertaken to understand and quantify this impact in the relatively rural and isolated region of northern New York. Local interviews and surveys, state business attraction and retention trend analysis, and a specially designed business attraction model were used to transform a typically speculative concept into a tangible one.

The purpose of the current study was to test the hypothesis that the beta-adrenergic innervation of the human eccrine sweat gland facilitates greater sweat production following heat acclimation. Eight healthy subjects (mean ± SD age: 25.1 ± 4.1 years, weight: 79.0 ± 16.1 kg, and VO(2)max: 48.5 ± 8.0 ml/kg/min) underwent active heat acclimation by walking at 40% of their VO(2)max for 8 days (90 min a day) in an environmental chamber (35.3 ± 0.8°C and 40.2 ± 2.1% rH). To test the hypothesis, the adrenergic component of sweat gland innervation was inhibited by continuously administering a 0.5% solution of the beta-adrenergic antagonist propranolol via iontophoresis to a 5 cm(2) area of one forearm during each 90-min exercise bout. The opposing control forearm underwent iontophoresis with a saline solution. Following heat acclimation, mean sweat rate in the inhibited and control forearm was 0.47 ± 0.30 mg/cm(2)/min and 0.44 ± 0.25mg/cm(2)/min, respectively. Findings of the current study fail to support the hypothesis that adrenergic innervation facilitates human eccrine sweat gland function during heat acclimation, as no significant differences in sweating were observed. In light of the above, the physiological significance of the dual cholinergic and adrenergic innervation of the eccrine sweat gland has yet to be determined.

With an ultrafast framing camera, we image the propagation of a shock wave on the nanosecond time-scale. Four frame x-ray phase-contrast radiographs are acquired using the pulse train from an x-ray free electron laser.