This note describes the program HEADTAIL for the simulation of transverse and longitudinal single bunch phenomena, with special emphasis on the instability and emittance growth induced by an electron cloud. All input parameters as well as the standard output files are described here. The note is intended to provide potential users with the guidelines for the installation and the use of the prog...

The urban stream syndrome may not be limited to streams in urbanized watersheds. We measured the spatial pattern of impervious cover in ∼82,800 small watersheds across the conterminous United States by comparing watershed-based and stream-based measures of imperviousness. The watershed-based measure was the commonly used watershed percentage impervious cover. The stream-based measure was the pe...

Infinite lists, or streams are often used in mathematical problems. We investigate three models to represent these streams in Coq, a proof assistant. For each of these models we investigate what it means for streams to be equal, and how we can prove these stream equalities. In the two most fruitful models we represent streams using a coinductive type, which means coinduction is crucial in our p...

Rapid freeze-quench (RFQ) trapping of short-lived reaction intermediates for spectroscopic study plays an important role in the characterization of biological reactions. Recently there has been considerable effort to achieve submillisecond reaction deadtimes. We present here a new, robust, high-velocity microfluidic mixer that enables such rapid freeze-quenching. It is a based on the mixing met...

The addition of mist to a flow of steam or gas offers enhanced cooling for many applications, including cooling of gas turbine blades. The enhancement mechanisms include effects of mixing of mist with the gas phase and effects of evaporation of the droplets. An impinging mist flow is attractive for study because the impact velocity is relatively high and predictable. Water droplets, less than 1...

The current work experimentally investigates the flow characteristics of an air jet impinging on an open rotor-stator system with a low non-dimensional spacing, G = 0.02, and with a very low aspect ratio, e/D = 0.25. The rotational Reynolds numbers varied from 0.33 × 10 to 5.32 × 10, while the jet Reynolds numbers ranged from 17.2×10 to 43×10. Particle image velocimetry (PIV) measurements were ...

This letter describes the flow kinematics and stability of thin fluid sheets produced by impinging obliquely aligned laminar jets of a series of viscoelastic wormlike micelle solutions. As the velocity of the impinging jets is increased, the sheets of viscoelastic fluid grow larger and eventually become unstable. High speed imaging reveals a transition through a series of striking new flow stru...

We report on the experimental evidence of the role of rotational alignment of the gas-phase molecules in the interaction of propylene with Ag(001). Molecular alignment has been controlled by a velocity selection of the impinging molecules, flying in a supersonic seeded molecular beam. The experimental findings indicate that at low surface coverage the sticking probability is independent of mole...

Impinging jet ventilation (IJV), which supplies a high momentum air impinging and spreading over the floor, could be used in both cooling heating modes. However, as low-level supply system, excessive temperature difference between head ankle levels may exist due to cool being directly supplied occupied zone. As one type of different personalized (PV) terminal device, ductless (DPV) is self-stan...