Atrazine and simazine are pre-emergence herbicides that are known to contaminate ground water from normal agricultural use. According to a recent U.S. Environmental Protection Agency (EPA) re-registration eligibility decision for atrazine, the breakdown products of atrazine and simazine were determined to be as toxic as the parent chemical. Consequently, EPA concluded that the concentrations of...

relief wells are used extensively to relieve excess hydrostatic pressure in pervious foundation strata overlain by impervious top strata, conditions which often exist landward of levees and downstream of dams and hydraulic structures. placing well outlets in below-surface trenches or collector pipes helps dry up seepage areas downstream of levees and dams. relief wells are often used in combina...

Availability of clean water and adequate sanitation facilities are of prime importance for limiting diarrheal diseases. We examined the spatial information on the groundwater quality and sanitation facilities of a village in southern India using Geographic Information System (GIS) tools. Place of residence, position of wells and latrines were mapped and well water samples were tested for microb...

In 1997, a compulsory notification system for waterborne outbreaks was introduced in Finland. The main aim of this notification is to obtain immediate information on suspected waterborne outbreaks in order to restrict and manage the outbreak promptly. During the past ten years, there have been 67 waterborne outbreaks in Finland, mainly associated with small groundwater supplies or private wells...

It is shown that optical rectification in biased quantum wells using specially shaped optical pulses can be used to generate quasi-half-cycle THz electromagnetic pulses. Namely, we investigate THz generation by pulses incorporating a rapid pi phase shift. We further explore the potential of this scheme for high-repetition-rate quasi-half-cycle THz pulse generation.

The Irish playwright and socialist George Bernard Shaw has been of marginal concern for historians of biology because his vitalist Lamarckism has been viewed as out of step with contemporary science. However, Julian Huxley and J.B.S. Haldane were certainly of the opinion that Shaw was a man of influence in this regard and took pains to counter his views in their own attempts to engage the publi...

We consider the classical dynamics of two particles moving in harmonic potential wells and interacting with the same external environment HE, consisting of N noninteracting chaotic systems. The parameters are set so that when either particle is separately placed in contact with the environment, a dissipative behavior is observed. When both particles are simultaneously in contact with HE an indi...