Lawrence Berkeley National Laboratory

About: Lawrence Berkeley National Laboratory is a facility organization based out in Berkeley, California, United States. It is known for research contribution in the topics: Catalysis & Laser. The organization has 28217 authors who have published 66584 publications receiving 4111321 citations. The organization is also known as: LBNL & LBL.

Lewis number effects in distributed flames

Abstract: Recent computational studies have simulated a mode of distributed premixed combustion where turbulent mixing plays a significant role in the transport of mass and heat near the reaction zone. Under these conditions, molecular transport processes play a correspondingly smaller role. A consequence of burning in this regime is that changes in the composition can occur within the flame zone that modify the local burning rate. This effect depends on the Lewis number (ratio of molecular heat to mass diffusivity), and so the transition to distributed burning will be different for fuels with different Lewis numbers. In this paper, we examine the role of Lewis number on flames in the distributed burning regime. We use high-resolution three-dimensional flame simulations with detailed transport models to explore the turbulent combustion of lean premixed hydrogen, methane and propane mixtures. Turbulence–flame interactions are found to be more pronounced in hydrogen than in the other fuels.

Spinodal Amplification of Density Fluctuations in Fluid-Dynamical Simulations of Relativistic Nuclear Collisions

Abstract: Extending a previously developed two-phase equation of state, we simulate head-on relativistic lead-lead collisions with fluid dynamics, augmented with a finite-range term, and study the effects of the phase structure on the evolution of the baryon density. For collision energies that bring the bulk of the system into the mechanically unstable spinodal region of the phase diagram, the density irregularities are being amplified significantly. The resulting density clumping may be exploited as a signal of the phase transition, possibly through an enhanced production of composite particles.

Engineered Biomimetic Polymers as Tunable Agents for Controlling CaCO3 Mineralization

Abstract: In nature, living organisms use peptides and proteins to precisely control the nucleation and growth of inorganic minerals and sequester CO2via mineralization of CaCO3. Here we report the exploitation of a novel class of sequence-specific non-natural polymers called peptoids as tunable agents that dramatically control CaCO3 mineralization. We show that amphiphilic peptoids composed of hydrophobic and anionic monomers exhibit both a high degree of control over calcite growth morphology and an unprecedented 23-fold acceleration of growth at a peptoid concentration of only 50 nM, while acidic peptides of similar molecular weight exhibited enhancement factors of only ∼2 or less. We further show that both the morphology and rate controls depend on peptoid sequence, side-chain chemistry, chain length, and concentration. These findings provide guidelines for developing sequence-specific non-natural polymers that mimic the functions of natural peptides or proteins in their ability to direct mineralization of CaCO...

Nonlinear quantum optics in a waveguide: distinct single photons strongly interacting at the single atom level.

Abstract: We propose a waveguide-QED system where two single photons of distinct frequency or polarization interact strongly. The system consists of a single ladder-type three level atom coupled to a waveguide. When both optical transitions are coupled strongly to the waveguide’s mode, we show that a control