Meeting the Mandate for Biofuels: Implications for Land Use and Food and Fuel Prices

Biofuels have been promoted to achieve energy security and as a solution to mitigating climate change. This research presents a framework to examine the extent to which biofuel mandates and subsidies reduce gasoline consumption and their implications for the food and fuel prices. A dynamic, multi-market equilibrium model, Biofuel and Environmental Policy Analysis Model (BEPAM), is used to estimate the effects of these policies on cropland usage between food crops and fuel crops and food and fuel prices, and to analyze the incentives provided by alternative policies for the mix of biofuels from corn and various cellulosic feedstocks that are economically viable over the 2007-2022 period. The provision of biofuel subsidies that accompany the mandate under the Renewable Fuel Standard (RFS) is found to significantly change this mix in favor of cellulosic biofuels produced from high yielding grasses and reduce the adverse impact of the RFS alone on food prices.Land Economics/Use, Resource /Energy Economics and Policy,

Mathematical Programming Modeling of Agricultural Supply Response

Agricultural and Food Policy, Land Economics/Use,

High-Resolution Shape Completion Using Deep Neural Networks for Global Structure and Local Geometry Inference

We propose a data-driven method for recovering miss-ing parts of 3D shapes. Our method is based on a new deep learning architecture consisting of two sub-networks: a global structure inference network and a local geometry refinement network. The global structure inference network incorporates a long short-term memorized context fusion module (LSTM-CF) that infers the global structure of the shape based on multi-view depth information provided as part of the input. It also includes a 3D fully convolutional (3DFCN) module that further enriches the global structure representation according to volumetric information in the input. Under the guidance of the global structure network, the local geometry refinement network takes as input lo-cal 3D patches around missing regions, and progressively produces a high-resolution, complete surface through a volumetric encoder-decoder architecture. Our method jointly trains the global structure inference and local geometry refinement networks in an end-to-end manner. We perform qualitative and quantitative evaluations on six object categories, demonstrating that our method outperforms existing state-of-the-art work on shape completion.Comment: 8 pages paper, 11 pages supplementary material, ICCV spotlight pape

Multiferroic heterostructures and tunneling junctions

AbstractMultiferroic heterostructures showing both electric and magnetic orders have attracted much attention because of their promising applications in the next generation of memories, sensors, and microwave devices and so on. The complex electronic and magnetic orders at the interface in multiferroic heterostructures will cause abundant physical phenomena due to the interplay among spin, charge, orbit, and lattice degrees of freedom, and various prototype devices have been achieved. In this review, we summarize some recent progresses mainly in the strain- and charge-mediated effects on the magnetic and electronic transport properties manipulated by electric/magnetic fields in multiferroic heterostructures. The recent advances in multiferroic tunnel junctions with ferroelectric barriers by using the spin polarized nature of magnetic materials are particularly presented, which exhibit magnetoelectric coupling effects at the interface and multi-stable resistance states in a single memory unit cell. Finally, the new inspiration for the design of spintronic devices having more energy efficiency and higher density is discussed

Low cycle fatigue damage model and sensitivity analysis of fatigue crack initiation by finite element approach

To meet the design requirements, different types of defects are often machined on the surface of fatigue components. Local stress concentration formed at the notch accelerate the initiation of fatigue crack, therefore greatly shorten the service lives of such components. Based on the theory of continuous damage mechanics and the principle of irreversible thermodynamics, the damage evolution model of low cycle fatigue is investigated. By programming the damage evolution model as UMAT subroutine and coupling it to ABAQUS, the fatigue damage and crack initiation life of notched P92 steel samples under specific loads are simulated, and the crack initiation location is determined. Furthermore, the damage evolution and crack initiation sensitivity of notch morphology are considered. The results show that the crack initiation occurs easily in the notch root where the damage is greatest and the plastic strain accumulates fastest under cyclic loading. The fatigue damage accumulates slowly at the initial stage, but the damage accumulates rapidly after the cumulative damage reaches a critical value. The fatigue damage evolution and fatigue initiation life are very sensitive to the notch morphology parameters. The notch morphology need to be carefully analyzed, to improve the fatigue life of the notched samples