Superconducting niobium cavities are important components of linear accelerators. Buffered chemical polishing (bcp) on the inner surface of the cavity is a standard procedure to improve its performance. The quality of bcp, however, has not been optimized well in terms of the uniformity of surface smoothness. A finite element computational fluid dynamics (cfd) model was developed to simulate the...

In this paper, a solar air collector duct equipped with baffles on back plate was numerically investigated. The Reynolds number (Re) varied from 5000 to 20,000, the angle baffle (a) 30° 120°, spacing ratio (Pr) 2 8, and blockage (Br) 0.375 0.75 examine their effects Nusselt (Nu), friction factor (f), thermohydraulic performance parameter (η). 2D numerical simulation used standard k-ε turbulence...

A gas relay in the transformer, an important non-electricity protection equipment, only triggers stem leaf spring for serious alarm when baffle rotates to a certain angle, which cannot judge transformer fault event of heavy before running state and development process, this paper puts forward kind based on panel corner monitoring methods. The partial structure is improved, signal extracted by i...

From Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom. Disclosures: None. Received for publication March 26, 2008; revisions received June 5, 2008; accepted for publication Sept 1, 2008; available ahead of print Jan 27, 2009. Address for reprints: Prem Venugopal, MCh, FRCS, Department of cardiac Surgery, East wing, St Thomas’ Hospital, Lambeth Palace Rd, London SE1 7EQ, United ...

Crowdsourcing is an increasingly popular phenomenon where companies solicit the help of the public in helping accomplish some of the activities commonly performed by employees or contractors. These activities can range from solving scientific problems that baffle the in-house experts to repetitive and boring tasks that are deemed too mundane for the employees. Other activities include content g...

Pregnancy can be daunting. Prenatal gadgets tempt expecting mothers at every turn, as the market is saturated with ever-changing options for mommy, daddy and baby. But underneath it all, we are simply driven by a common desire to fulfill the ideals of motherhood and to connect with our babies. Stroller technology alone is enough to baffle the mind. Maybe next year we’ll see an organic, Tempur-P...

A micro-perforated panel (MPP) with a backing cavity is a well known device for efficient noise absorption. This configuration has been thoroughly studied in the experimental conditions of an acoustic tube (Kundt tube), in which the MPP is excited by a normal incident plane wave in one dimension. In a more practical situation, the efficiency of MPP may be influenced by the vibro-acoustic behavi...

The potential for acoustic metamaterials to provide a breakthrough in sound attenuation has been unlocked recent times due advancements additive manufacturing techniques. These materials allow the targeting of specific frequencies attenuation. To date have not experimentally tested an automotive silencer performance enhancement. This study investigates effect within representative silencer. res...