Global modeling of hydrogen using GFDL-AM4.1: Sensitivity of soil removal and radiative forcing

Hydrogen (H₂) has been proposed as an alternative energy carrier to reduce the carbon footprint and associated radiative forcing of the current energy system. Here, we describe the representation of H₂ in the GFDL-AM4.1 model including updated emission inventories and improved representation of H₂ soil removal, the dominant sink of H₂. The model best captures the overall distribution of surface H₂, including regional contrasts between climate zones, when v_d(H₂) is modulated by soil moisture, temperature, and soil carbon content. We estimate that the soil removal of H₂ increases with warming (2–4% per K), with large uncertainties stemming from different regional response of soil moisture and soil carbon. We estimate that H₂ causes an indirect radiative forcing of 0.84 mW m^?2/(Tg(H₂)yr^?1) or 0.13 mW m^?2 ppbv^?1, primarily due to increasing CH₄ lifetime and stratospheric water vapor production.     

Heat transfer due to buoyancy-driven convective interaction in enclosures: Fundamentals and applications

Coupling of two basic mechanisms of gravity-driven convection is named as convective interactions in the paper. Classification of applications of the interaction mechanism with different orientation of input (output) heat flux to the gravity force is suggested. Brief overview and comments are done. For illustration of the classification a number of examples on the basis of experience in technique and technology are presented. Some convective interaction features with change of orientation for a model of differently heated square are shown. Critical value of the angle for bifurcation onset, heat transfer and temperature stratification in dependency of the angle, temperature oscillations onset in dependency of Pr number for inclined square are presented.     

Online Scheduling FIFO Policies with Admission and Push-Out

We consider the problem of managing a bounded size First-In-First-Out (FIFO) queue buffer, where each incoming unit-sized packet requires several rounds of processing before it can be transmitted out. Our objective is to maximize the total number of successfully transmitted packets. We consider both push-out (when a policy is permitted to drop already admitted packets) and non-push-out cases. We provide worst-case guarantees for the throughput performance of our algorithms, proving both lower and upper bounds on their competitive ratio against the optimal algorithm, and conduct a comprehensive simulation study that experimentally validates predicted theoretical behavior.     

Fuel-Rod Design and Materials Validation for 10 MW NPP

Atomic Energy - The timeliness of the development of small nuclear power plants is determined by their economic utility and prospects for use as an energy source in remote regions with...     

Effect of thermal annealing on the properties of borophosphate systems containing simulated Cs + Sr radioactive waste fractions

The effect of thermal annealing on the resistance of borophosphate systems to crystallization and the effect of crystallization on the hydrolytic stability of the materials were examined. Systems containing simulated Cs + Sr fraction were studied. Annealing at 400–500°C leads to a noticeable decrease in the leach rate. Annealing at a higher temperature, 600°C, leads to crystallization of the glass and to a considerable increase in the leach rate.