Context. The turbulent pumping effect corresponds to the transport of magnetic flux due to the presence of density and turbulence gradients in convectively unstable layers. In the induction equation it appears as an advective term and for this reason it is expected to be important in the solar and stellar dynamo processes. Aims. In this work, we have explored the effects of the turbulent pumpin...

Detecting and quantifying small drawdown at observation wells distant from the pumping well greatly expands the characterized aquifer volume. However, this detection is often obscured by water level fluctuations such as barometric and tidal effects. A reliable analytical approach for distinguishing drawdown from nonpumping water-level fluctuations is presented and tested here. Drawdown is disti...

Head measurements at a single observation well during a cross-hole pumping test carry a great amount of information about aquifer heterogeneity other than the average property of the aquifer as implied in Theis analysis of aquifer test. In this commentary, we use simple examples and a probabilistic reasoning approach based on Darcy’s law to unravel this information, buried in the results of qua...

An analytical solution for the case of transient, pumping-induced drawdown in a nonuniform aquifer is presented. The nonuniform aquifer is conceptualized as a uniform matrix into which a disk of anomalous properties has been placed. The disk can be arbitrarily located with respect tothe pumping well. This solution can be used to develop considerable insight concerning the nature of drawdown i n...

Insects that are small or exhibit low metabolic rates are considered to not require active ventilation to augment diffusive gas exchange. Some pupae with low metabolic rates exhibit abdominal pumping, a behaviour that is known to drive tracheal ventilation in the adults of many species. However, previous work on pupae suggests that abdominal pumping may serve a non-respiratory role. To study th...

Around the third week after gestation in embryonic development, the human heart consists only of a valvless tube, unlike a fully developed adult heart, which is multi-chambered. At this stage in development, the heart valves have not formed and so net flow of blood through the heart must be driven by a different mechanism. It is hypothesized that there are two possible mechanisms that drive blo...

VACUUM PUMPING STUDY OF TITANIUM-ZIRCONIUM-VANADIUM THIN FILMS* Yulin Li and Simon Ho, LEPP, Cornell University, Ithaca, NY 14853, USA Abstract Vacuum pumping via non-evaporable getter (NEG) thin film deposited directly onto the interior of a vacuum chamber is a novel way to achieve extreme high vacuum. As part of R&D efforts for the proposed Energy Recovery Linac at Cornell, the pumping perfor...

In 1950, French physicist Alfred Kastler introduced the concept of modern optical pumping, for which he was awarded the Nobel Prize in 1966. The process of optical pumping involves using photons of a desired wavelength and polarization to change the distribution of a gas of atoms from thermal equilibrium. Today, optical pumping is a critical tool in modern Physics experiments, and is the basis ...

In C. elegans, pharyngeal pumping is regulated by the presence of bacteria. In response to food deprivation, the pumping rate rapidly declines by about 50-60%, but then recovers gradually to baseline levels on food after 24 hr. We used this system to study the role of insulin/IGF-1 signaling (IIS) in the recovery of pharyngeal pumping during starvation. Mutant strains with reduced function in t...

Dial balances are preferred for speed in today's crowded school laboratory. Dial-O-Gram 310 is preferred for speed, accuracy, and the ruggedness which withstands student handling and makes expensive service contracts unnecessary. The unique accuracy of Dial-O-Gram 310 is the result of extensive research by Ohaus on the cause and correction of errors in spiral spring mechanisms. Only Ohaus uses ...