Benzylammonium 2,4-bis(dicyanomethylene)-2,3-dihydroisoindolide

The cation and anion of the title salt, C⁷H₁₀N⁺.C₁₄H₄N₅-, are both bisected by a crystallographic mirror plane. Extensive hydrogen bonding, with the R₆⁶(28) graph-set motif, connects the ions into layers

Series arrays of planar long Josephson junctions for high dynamic range magnetic flux detection

This work is licensed under a Creative Commons Attribution 4.0 International License.We investigated series arrays of closely spaced, planar long Josephson junctions for magnetic field transduction in Earth’s field, with a linear response and high dynamic range. The devices were fabricated from thin film high-temperature superconductor YBa2Cu3O7−δ (YBCO) thin films, using focused helium ion beam irradiation to create the Josephson barriers. Four series arrays, each consisting of several hundreds of long junctions, were fabricated and electrically tested. From fits of the current-voltage characteristics, we estimate the standard deviation in critical current to be around 25%. Voltage-magnetic field measurements exhibit a transfer function of 42 mV/mT and a linear response over a range of 303 μT at 71 K, resulting in a dynamic range of 124 dB.FOSR FA 9550-17-C-0006FA 9550-15-1-0218ARO Grant W911NF1710504NSF Grant No. 166444

Flight-based chemical characterization of biomass burning aerosols within two prescribed burn smoke plumes

Biomass burning represents a major global source of aerosols impacting direct radiative forcing and cloud properties. Thus, the goal of a number of current studies involves developing a better understanding of how the chemical composition and mixing state of biomass burning aerosols evolve during atmospheric aging processes. During the Ice in Clouds Experiment-Layer Clouds (ICE-L) in the fall of 2007, smoke plumes from two small Wyoming Bureau of Land Management prescribed burns were measured by on-line aerosol instrumentation aboard a C-130 aircraft, providing a detailed chemical characterization of the particles. After ~2–4 min of aging, submicron smoke particles, produced primarily from sagebrush combustion, consisted predominantly of organics by mass, but were comprised primarily of internal mixtures of organic carbon, elemental carbon, potassium chloride, and potassium sulfate. Significantly, the fresh biomass burning particles contained minor mass fractions of nitrate and sulfate, suggesting that hygroscopic material is incorporated very near or at the point of emission. The mass fractions of ammonium, sulfate, and nitrate increased with aging up to ~81–88 min and resulted in acidic particles. Decreasing black carbon mass concentrations occurred due to dilution of the plume. Increases in the fraction of oxygenated organic carbon and the presence of dicarboxylic acids, in particular, were observed with aging. Cloud condensation nuclei measurements suggested all particles >100 nm were active at 0.5% water supersaturation in the smoke plumes, confirming the relatively high hygroscopicity of the freshly emitted particles. For immersion/condensation freezing, ice nuclei measurements at −32 °C suggested activation of ~0.03–0.07% of the particles with diameters greater than 500 nm

Relationships of Biomass-Burning Aerosols to Ice in Orographic Wave Clouds

Ice concentrations in orographic wave clouds at temperatures between −24° and −29°C were shown to be related to aerosol characteristics in nearby clear air during five research flights over the Rocky Mountains. When clouds with influence from colder temperatures were excluded from the dataset, mean ice nuclei and cloud ice number concentrations were very low, on the order of 1–5 L^(−1). In this environment, ice number concentrations were found to be significantly correlated with the number concentration of larger particles, those larger than both 0.1- and 0.5-μm diameter. A variety of complementary techniques was used to measure aerosol size distributions and chemical composition. Strong correlations were also observed between ice concentrations and the number concentrations of soot and biomass-burning aerosols. Ice nuclei concentrations directly measured in biomass-burning plumes were the highest detected during the project. Taken together, this evidence indicates a potential role for biomass-burning aerosols in ice formation, particularly in regions with relatively low concentrations of other ice nucleating aerosols

Observation of playa salts as nuclei in orographic wave clouds

During the Ice in Clouds Experiment-Layer Clouds (ICE-L), dry lakebed, or playa, salts from the Great Basin region of the United States were observed as cloud nuclei in orographic wave clouds over Wyoming. Using a counterflow virtual impactor in series with a single-particle mass spectrometer, sodium-potassium-magnesium-calcium-chloride salts were identified as residues of cloud droplets. Importantly, these salts produced similar mass spectral signatures to playa salts with elevated cloud condensation nuclei (CCN) efficiencies close to sea salt. Using a suite of chemical characterization instrumentation, the playa salts were observed to be internally mixed with oxidized organics, presumably produced by cloud processing, as well as carbonate. These salt particles were enriched as residues of large droplets (>19 μm) compared to smaller droplets (>7 μm). In addition, a small fraction of silicate-containing playa salts were hypothesized to be important in the observed heterogeneous ice nucleation processes. While the high CCN activity of sea salt has been demonstrated to play an important role in cloud formation in marine environments, this study provides direct evidence of the importance of playa salts in cloud formation in continental North America has not been shown previously. Studies are needed to model and quantify the impact of playas on climate globally, particularly because of the abundance of playas and expected increases in the frequency and intensity of dust storms in the future due to climate and land use changes

Can Perceived Support for Entrepreneurship Keep Great Faculty in the Face of Spinouts?

Despite the recent increase in academic entrepreneurship research, we still know relatively little about the degree of involvement of academic inventors in university spinouts. In this study, we distinguish between academic inventors who leave the university after the creation of a spinout (academic exodus) and those who maintain their university affiliation (academic stasis). Drawing from the literature on innovation-supportive climates and from organizational support theory, we argue that perceptions of institutional support and departmental norms regarding entrepreneurship are associated with the exodus versus stasis decision. We find that inventors who have higher perceptions of institutional support for entrepreneurship are less likely to leave. This relationship is enhanced by perceptions of favorable departmental norms toward entrepreneurship. We discuss the implications of our work for the literature on academic entrepreneurship, innovation-supportive climates, and perceived organizational support. Our study has clear policy implications for universities, policymakers, and funders who aim to stimulate academic entrepreneurship, but are concerned about losing entrepreneurial faculty. Specifically, we advise universities and policymakers to actively support academic inventors wishing to spin out and to monitor this support in a customer-friendly manner, in order to ensure that the inventors' perceptions of support are favorable. It is also important for universities to look out for inconsistencies between a supportive environment for entrepreneurship at the institutional level and unfavorable norms toward entrepreneurship at the departmental level; such inconsistencies can lead good faculty members out of academia. More broadly, universities can pursue an aggregation strategy that aims to retain both a research and commercialization identity while building strong links between them