AUTOMATION OR OPENNESS?: TECHNOLOGY AND TRADE IMPACTS ON COSTS AND LABOR COMPOSITION IN THE FOOD SYSTEM

Productivity, technology, production costs, Productivity Analysis, Research and Development/Tech Change/Emerging Technologies,

Corporate Social Responsibility and Economic Performance

We describe some perspectives on corporate social responsibility (CSR), in order to provide a context for considering the strategic motivations and implications of CSR. Based on this framework, which is based on characterizing optimal firm decision making and underlies most existing work on CSR, we propose an agenda for further theoretical and empirical research on CSR. We then summarize and relate the articles in this special issue to the proposed agenda.

First-principles study of the solubility, diffusion, and clustering of C

Within the framework of density functional theory, we investigate three key properties of a C interstitial solid solution in crystalline Ni: the heat of solution (⌬H sol ), the activation energy for C diffusion (E a ), and the C-C pair binding energy (B). In addition, we assess the impact of Ni magnetism upon each property. The most energetically favorable lattice site for C is the interstitial octahedral site (O site͒, which is 1.59 eV lower in energy than the tetrahedral site (T site͒. Using the nudged elastic band method, we determine that diffusion between O sites proceeds via a T-site intermediate. The calculated activation energy (E a ϭ1.62 eV), is in good agreement with experimental data from the literature ͑1.54 -1.71 eV͒. The binding of C pairs is sensitive to magnetization effects, and is negligible (BϷ0 eV) in the ferromagnetic state, but repulsive in the paramagnetic state (BϭϪ0.2 eV). These results are consistent with anelastic relaxation experiments, which find B Ͻ0.1 eV in the FM state. The calculated heat of solution in the paramagnetic Ni state (⌬H sol para ϭ0.2-0.35 eV) is in reasonable agreement with high-temperature experimental values of ϳ0.4 eV, and the magnitude of ⌬H sol in the ferromagnetic state is found to be about 0.4 eV greater than in the paramagnetic state. Lastly, we briefly assess the effect of pseudopotential choice and exchange-correlation functionals upon the accuracy of the results

Electronic structure of Li 2 O 2 {0001} surfaces

Abstract The surface properties of the Li 2 O 2 discharge phase are expected to impact strongly the capacity, rate capability, and rechargeability of Li-oxygen batteries. Prior calculations have suggested that the presence of halfmetallic surface states in Li 2 O 2 may mitigate electrical passivation resulting from the growth of Li 2 O 2 , which is a bulk insulator. Here we revisit the electronic structure of bulk Li 2 O 2 and the dominant Li 2 O 2 {0001} surface by comparing results obtained with the PBE GGA functional, the HSE06 hybrid functional, and quasiparticle GW methods. Our results suggest that the bulk band gap lies between the value predicted by the G 0 W 0 method, 5.15 eV, and the value predicted by the self-consistent quasiparticle GW (scGW) approximation, 6.37 eV. The PBE, HSE06, and scGW methods agree that the most stable surface, an oxygen-rich {0001} termination, is indeed half-metallic. This result supports the notion that the electronic structure of surfaces may play an important role in understanding performance limitations in Li-oxygen batteries

Climatic Drivers for Multi-Decadal Shifts in Solute Transport and Methane Production Zones within a Large Peat Basin

Northern peatlands are an important source for greenhouse gases but their capacity to produce methane remains uncertain under changing climatic conditions. We therefore analyzed a 43-year time series of pore-water chemistry to determine if long-term shifts in precipitation altered the vertical transport of solutes within a large peat basin in northern Minnesota. These data suggest that rates of methane production can be finely tuned to multi-decadal shifts in precipitation that drive the vertical penetration of labile carbon substrates within the Glacial Lake Agassiz Peatlands. Tritium and cation profiles demonstrate that only the upper meter of these peat deposits was flushed by downwardly moving recharge from 1965 through 1983 during a Transitional Dry-to-Moist Period. However, a shift to a moister climate after 1984 drove surface waters much deeper, largely flushing the pore waters of all bogs and fens to depths of 2 m. Labile carbon compounds were transported downward from the rhizosphere to the basal peat at this time producing a substantial enrichment of methane in Delta C-14 with respect to the solid-phase peat from 1991 to 2008. These data indicate that labile carbon substrates can fuel deep production zones of methanogenesis that more than doubled in thickness across this large peat basin after 1984. Moreover, the entire peat profile apparently has the capacity to produce methane from labile carbon substrates depending on climate-driven modes of solute transport. Future changes in precipitation may therefore play a central role in determining the source strength of peatlands in the global methane cycle