Radiation, optical, power flow, and electrical diagnostics at the Z facility: Layout and techniques utilized to operate in the harsh environment.

The Z machine is a current driver producing up to 30 MA in 100 ns that utilizes a wide range of diagnostics to assess accelerator performance and target behavior conduct experiments that use the Z target as a source of radiation or high pressures. We review the existing suite of diagnostic systems, including their locations and primary configurations. The diagnostics are grouped in the following categories: pulsed power diagnostics, x-ray power and energy, x-ray spectroscopy, x-ray imaging (including backlighting, power flow, and velocimetry), and nuclear detectors (including neutron activation). We will also briefly summarize the primary imaging detectors we use at Z: image plates, x-ray and visible film, microchannel plates, and the ultrafast x-ray imager. The Z shot produces a harsh environment that interferes with diagnostic operation and data retrieval. We term these detrimental processes "threats" of which only partial quantifications and precise sources are known. We summarize the threats and describe techniques utilized in many of the systems to reduce noise and backgrounds.

Hybrid target design for imprint mitigation in direct-drive inertial confinement fusion.

A target design for mitigating the Rayleigh-Taylor instability is proposed for use in high energy density and direct-drive inertial confinement fusion experiments. In this scheme, a thin gold membrane is offset from the main target by several-hundred microns. A strong picket on the drive beams is incident upon this membrane to produce x rays which generate the initial shock through the target. The main drive follows shortly thereafter, passing through the ablated shell and directly driving the main target. The efficacy of this scheme is demonstrated through experiments performed at the OMEGA EP facility, showing a reduction of the Rayleigh-Taylor instability growth which scales exponentially with frequency, suppressing development by at least a factor of 5 for all wavelengths below 100 µm. This results in a delay in the time of target perforation by ∼40%.

Erratum: Measurement of Body-Centered-Cubic Aluminum at 475 GPa [Phys. Rev. Lett. 119, 175702 (2017)].

This corrects the article DOI: 10.1103/PhysRevLett.119.175702.

Measurement of Body-Centered-Cubic Aluminum at 475 GPa.

Nanosecond in situ x-ray diffraction and simultaneous velocimetry measurements were used to determine the crystal structure and pressure, respectively, of ramp-compressed aluminum at stress states between 111 and 475 GPa. The solid-solid Al phase transformations, fcc-hcp and hcp-bcc, are observed at 216±9 and 321±12 GPa, respectively, with the bcc phase persisting to 475 GPa. The high-pressure crystallographic texture of the hcp and bcc phases suggests close-packed or nearly close-packed lattice planes remain parallel through both transformations.

Absolute calibration of the OMEGA streaked optical pyrometer for temperature measurements of compressed materials.

Experiments in high-energy-density physics often use optical pyrometry to determine temperatures of dynamically compressed materials. In combination with simultaneous shock-velocity and optical-reflectivity measurements using velocity interferometry, these experiments provide accurate equation-of-state data at extreme pressures (P > 1 Mbar) and temperatures (T > 0.5 eV). This paper reports on the absolute calibration of the streaked optical pyrometer (SOP) at the Omega Laser Facility. The wavelength-dependent system response was determined by measuring the optical emission from a National Institute of Standards and Technology-traceable tungsten-filament lamp through various narrowband (40-nm-wide) filters. The integrated signal over the SOP's ∼250-nm operating range is then related to that of a blackbody radiator using the calibrated response. We present a simple closed-form equation for the brightness temperature as a function of streak-camera signal derived from this calibration. Error estimates indicate that brightness temperature can be inferred to a precision of <5%.

Temperature measurements of shocked silica aerogel foam.

We present recent results of equation-of-state (EOS) measurements of shocked silica (SiO_{2}) aerogel foam at the OMEGA laser facility. Silica aerogel is an important low-density pressure standard used in many high energy density experiments, including the novel technique of shock and release. Due to its many applications, it has been a heavily studied material and has a well-known Hugoniot curve. This work then complements the velocity and pressure measurements with additional temperature data providing the full EOS information within the warm dense matter regime for the temperature interval of 1-15 eV and shock velocities between 10 and 40 km/s corresponding to shock pressures of 0.3-2 Mbar. The experimental results were compared with hydrodynamic simulations and EOS models. We found that the measured temperature was systematically lower than suggested by theoretical calculations. Simulations provide a possible explanation that the emission measured by optical pyrometry comes from a radiative precursor rather than from the shock front, which could have important implications for such measurements.

Review of submarine groundwater discharge (SGD) in coastal zones of the Southeast and Gulf Coast regions of the United States with management implications.

Groundwater serves as the primary drinking water source for over half of the coastal populations of the Southeast and Gulf Coast regions, two of the fastest growing regions in the United States. Increased demand for this resource has exceeded sustainable yields in many areas and induced saltwater intrusion of coastal aquifers. A process associated with coastal groundwater, submarine groundwater discharge (SGD), has been documented as a source of subsurface fluids to coastal ocean environments throughout the Southeast and Gulf Coast regions and is potentially a significant contributor to nearshore water and geochemical budgets (i.e., nutrients, carbon, trace metals) in many coastal regions. The importance of groundwater as a drinking water source for coastal populations and the influences of submarine groundwater discharge to the coastal ocean warrant increased research and management of this resource. This paper highlights findings from recent SGD studies on three hydrogeologically different continental margins (Onslow Bay, NC, southern Florida, and the Louisiana margin), provides background on the common methods of assessing SGD, and suggests a regional management plan for coastal groundwater resources. Suggested strategies call for assessments of SGD in areas of potentially significant discharge, development of new monitoring networks, and the incorporation of a regional coastal groundwater resources council.

Women in agriculture: risks for occupational injury within the context of gendered role.

Women continue to make significant contributions to farming. Not only do women participate in the traditional roles of homemaker, caregiver, and wife, they also work side-by-side with their spouses in keeping the farm viable. More daughters are entering the farming business, either as partners with other family members or as independent operators. Each year since the United States Department of Agriculture began including gender in the Census of Agriculture, the percentage of women engaged in agriculture has increased, and women's participation in agriculture is increasing faster than in other business segments. This article examines the role of women in agriculture and how sociocultural, economic, and physical factors may affect women's exposure to injury-producing events and their knowledge and beliefs about injury prevention. To date, few studies have examined work-related unintentional injuries among farm women. Even less is known about the extent to which occupational risks are recognized when women seek medical care. Differences in size and stature, increased physical strain, and low maximal oxygen uptake may predispose women to ergonomic-related injuries. Limitations of current research and recommendations for future analyses are discussed.

Kentucky legislators' views on tobacco policy.

CONTEXT: Kentucky leads the nation in adult and teen smoking prevalence. Even though Kentucky is one of the most tobacco-dependent states, tobacco policy is subject to change in light of possible national tobacco legislation. OBJECTIVE: To describe the degree of agreement among Kentucky legislators regarding tobacco control and tobacco farming policy, and to discover whether use of the policy Delphi method produces a shift toward consensus on tobacco policy. DESIGN: A two-round policy Delphi study was conducted using in-person interviews. SETTING: Legislators' offices in Frankfort, Kentucky. PARTICIPANTS: Volunteer sample of 116 Kentucky legislators (84% response rate). MAIN OUTCOME MEASURES: Degree of agreement on tobacco control and tobacco farming policies. RESULTS: Lawmakers were highly supportive of policies to lessen the state's dependence on tobacco, and were favorable toward stronger tobacco control policies. There were discrepancies, however, between what policies legislators thought were desirable and what policies were realistic. Tobacco interests were identified as possible explanations for this disparity. Tobacco allotment ownership was associated with less support for tobacco control and tobacco farming policies. A shift toward consensus on tobacco policy was achieved in the second round for 45% of the interview items common to both rounds. CONCLUSIONS: Kentucky legislators were highly supportive of reducing the state's dependence on tobacco and more supportive of tobacco control policies than expected. The policy Delphi method has the potential for shifting opinions about tobacco policies among state legislators. The findings of this study identify opportunities for public health policy change in one of the most tobacco-dependent states in the United States.

A workable solution to test review.

The authors describe a test review procedure that provides immediate feedback for faculty and students. The review procedure is described and the benefits for students and faculty are discussed with specific examples. Methods for using information gained from the test review procedure are also suggested.

Ethylene glycol toxicity.

Ingestion of ethylene glycol is a rare occurrence, but it is an attractive agent for intoxication and suicide. Treatment is aimed at rapid excretion of the EG, prevention of the formation of metabolites, and the prevention and treatment of renal failure. Prior to discharge, Mr K revealed that he had drunk the antifreeze because he was despondent about his work situation. He had a short, but intensive trajectory that followed the three-system-involvement classic to EG poisoning, with the renal system most severely affected. Mr K was discharged from the hospital one week after admission and referred to appropriate community resources for counseling. The critical care nurse plays a key role in alleviating the hazards of this complex disorder through complete and ongoing assessment of all systems.

Alternative Respiratory Path Capacity in Plant Mitochondria: Effect of Growth Temperature, the Electrochemical Gradient, and Assay pH.

Influence of growth temperature on the capacity of the mitochondrial alternative pathway of electron transport was investigated using etiolated corn (Zea mays L.) seedlings. These seedlings were grown to comparable size in either a warm (30 degrees C) or a cold (13 degrees C) temperature regime, and then their respiration rates were measured as O(2) uptake at 25 degrees C. The capacity of the alternative pathway (KCN-insensitive O(2) uptake) was found essentially to double in shoots of cold-grown seedlings. This increased capacity slowly developed over several days growth in the cold, but was lost within 1 day when the seedlings were exposed to a warm regime. When mitochondria were isolated from the shoots of these seedlings, a greater potential for flow through the alternative path was observed in mitochondria from the cold-grown seedlings with all substrates used (an average increase of 84%). Using exogenous NADH as the substrate, the effect of the electrochemical gradient on measurable capacities of the cytochrome and alternative pathways was investigated in mitochondria from both etiolated seedlings and thermogenic spadices. The uncoupler FCCP (p-trifluoromethoxycarbonylcyanide phenylhydrazone) was used to diminish the electrochemical gradient when desired. In corn (Zea mays L.) shoot and mung bean (Vigna radiata L.) hypocotyl mitochondria, which have relatively low capacities of the alternative pathway, increased flow through the cytochrome chain in the absence of the electrochemical gradient was found not to influence the potential for flow through the alternative path. However, in mitochondria from skunk cabbage (Symplocarpus foetidus L.) and voodoo lily (Sauromatum guttatum Schott) spadices, which have high capacities of the alternative pathway, increased flow through the cytochrome chain in the absence of the gradient occurred at the expense of flow through the alternative pathway. These results suggest that in mitochondria of thermogenic spadices, the combined capacities of the cytochrome and alternative paths exceed the capacity of the exogenous NADH dehydrogenase. The effect of assay pH on measurable capacities of the cytochrome and alternative paths was determined over a pH range of 5.6 to 8.8 using exogenous NADH as the mitochondrial substrate. When the electrochemical gradient was present, it limited the electron transport rate and little effect of assay pH was observed. However, when formation of the gradient was prevented through inclusion of FCCP, measurable capacities of the cytochrome and alternative paths were found to be greatly influenced by pH. This experiment also revealed that the potential for respiratory control is largely dependent upon the assay pH.