Mathematical Programming Modeling of Agricultural Supply Response

Agricultural and Food Policy, Land Economics/Use,

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,

An Investigation into the Environmental and Human Health Implications of Microplastic Toxicity

The pervasive distribution of microplastics in the environment has become a global concern, with potential repercussions for human health, ecosystems, and biological toxicity. This review synthesizes current research on the environmental distribution, potential pathways of human exposure, and health implications of microplastics. We highlight the methodologies employed in quantifying and characterizing microplastics, as well as the toxicological assessments conducted in various biological matrices. Our findings indicate a significant correlation between microplastic exposure and adverse health outcomes, necessitating urgent policy interventions and further research.

High-dimensional FGM-ResNet modelling of turbulent spray combustion: Effects of evaporation non-adiabacity and scalar correlation

In the stratified or partially premixed piloted jet flames, previous experimental and priori studies have identified a strong correlation between mixture fraction and progress variable. In the framework of large-eddy simulation (LES) and flamelet-generated manifolds (FGM) approach, a joint probability density function (PDF) method is constructed to characterize subgrid correlations. To pave the way for high dimensional tabulation modeling, a deep residual network (ResNet) is trained, dramatically reducing the memory footprint of tabulation. The Message Passing Interface (MPI) shared memory technique is applied to load the original chemical table during parallel computations. Application of LES to a partially pre-vaporized ethanol spray flame demonstrates good agreement with experimental results. Consideration of the subgrid correlation results in a noticeable improvement in temperature prediction. Calculations using ResNet show a notable consistency with those using chemical tables. Visualization of enthalpy highlights the significance of non-adiabatic tabulation in modeling liquid fuel combustion. The unscaled progress variable is selected to better describe the chemical reaction rate in the blending zone of an air stream and a pilot stream with the product of a fully burnt lean fuel mixture. The impact of the source term due to evaporation in the transport equation of the progress variable is validated. The correlation coefficient is found to significantly influence the chemical reaction rate. The subgrid-scale interaction between liquid fuel evaporation and subgrid correlation is elucidated

Towards on-chip time-resolved thermal mapping with micro-/nanosensor arrays

In recent years, thin-film thermocouple (TFTC) array emerged as a versatile candidate in micro-/nanoscale local temperature sensing for its high resolution, passive working mode, and easy fabrication. However, some key issues need to be taken into consideration before real instrumentation and industrial applications of TFTC array. In this work, we will demonstrate that TFTC array can be highly scalable from micrometers to nanometers and that there are potential applications of TFTC array in integrated circuits, including time-resolvable two-dimensional thermal mapping and tracing the heat source of a device. Some potential problems and relevant solutions from a view of industrial applications will be discussed in terms of material selection, multiplexer reading, pattern designing, and cold-junction compensation. We show that the TFTC array is a powerful tool for research fields such as chip thermal management, lab-on-a-chip, and other novel electrical, optical, or thermal devices