OBJECTIVE Women at risk for delayed onset of lactation are often advised to pump their breasts before lactogenesis stage II to hasten the timing of this process. The effectiveness of this clinical practice has not been previously evaluated. This study investigates the effects of breast pumping before the onset of lactation on early milk transfer and subsequent breastfeeding duration among women...

In complex hydrogeological environments the effective management of groundwater quality problems by pump-and-treat operations can be most confidently achieved if the mixing dynamics induced within the aquifer by pumping are well understood. The utility of isotopic environmental tracers (C-, H-, O-, S-stable isotopic analyses and age indicators-(14) C, (3) H) for this purpose is illustrated by t...

Conventional pumping test analysis methodology assumes that aquifer transmissivity is invariant in space. The ramifications. of this assumption are examined for_ hypothetic~! ~nits who~e va~ations in transmissivity are considered to be reasonable representatmns of vanatmns possible m natural systems. The dependence of pumping test transmissivity on spatial (angular and radial) and temporal loca...

We have recently developed a theory that can be used to locate the source of contamination captured by a pumping well [1]. Accounting for advection, dispersion, linearequilibrium sorption, aquifer heterogeneity, and regional natural recharge, the theory is based on the concept of travel time probability. This probability describes the time for a particle to travel from a source location to the ...

Oscillatory pumping tests-in which flow is varied in a periodic fashion-provide a method for understanding aquifer heterogeneity that is complementary to strategies such as slug testing and constant-rate pumping tests. During oscillatory testing, pressure data collected at non-pumping wells can be processed to extract metrics, such as signal amplitude and phase lag, from a time series. These me...

[1] A semianalytical solution is presented for a mathematical model describing the flow of groundwater in response to a slug or pumping test in a highly permeable, confined aquifer. This solution, which is appropriate for wells of any degree of penetration and incorporates inertial mechanisms at both the test and observation wells, can be used to gain new insights into hydraulic tests in highly...

Nearly 40 years ago, Neuman (1968) developed an analytical solution for drawdown in a system of three aquifers separated by two aquitards when one of the aquifers is pumped at a constant rate. Whereas the simpler case of two aquifers separated by one aquitard has been presented by Neuman and Witherspoon (1969a), the full five-layer solution has not been previously evaluated. We do so here using...

an appropriate method to determine the hydraulic conductivity above water table is guelph permeameter. using this method, experiments can be carried out by one person in a short period. several investigators have commented on the systematic difference between the hydraulic conductivity obtained by guelph permeameter and shallow well pumping test (swpt) methods. therefore, the purpose of this re...