This paper reports the atom probe analysis results of the oxygen dissolved in the as-cast amorphous and crystallized Zr65Cu15Al10Pd10 and Zr65Cu17.5Ni10Al7.5 alloys. Impurity oxygen ranging from 0.1 to 1 at.% is dissolved uniformly in the as-quenched Zr65Cu15Al10Pd10 and Zr65Cu17.5Ni10Al7.5 amorphous alloys even though the oxygen is not added intentionally. When the Zr65Cu15Al10Pd10 alloy is cr...

For the determination of dissolved oxygen, working principle of the fiber optic oxygen sensor is studied. The sensor system calibration method and temperature compensation measures and their maintenance methods are analyzed. The dissolved oxygen sensors current widely using oxygen electrode and optical fiber oxygen sensor are compared. Optical fiber probe sensor is used in the current system, t...

We are concerned with the inverse problem of detecting sources in a coupled diffusion-reaction system. This problem arises from the Biochemical Oxygen Demand-Dissolved Oxygen model() governing the interaction between organic pollutants and the oxygen available in stream waters. The sources we consider are point-wise and simulate stationary or moving pollution sources. The ultimate objective is ...

We present a methodology to model water, heat, and dissolved oxygen budgets on short time scales within a shallow estuarine environment using limited local water quality and climatic data. A tidally restricted eutrophic pond in Elkhorn Slough, California, experiences extreme diel dissolved oxygen (DO) variations during warm sunny days and neap tidal cycles. Empirical relationships between biolo...

Lactate dehydrogenase (LDH) has been shown to play an important role in adaptation of several aquatic species to different habitats. The genomes of Daphnia pulex, a pond species, and Daphnia pulicaria, a lake inhabitant, encode two L-LDH enzymes, LDHA and LDHB. We estimated relative levels of Ldh gene expression in these two closely related species and their hybrids in four environmental settin...

The physicochemical qualities of a typical rural-based river were assessed over a 12-month period from August 2010 to July 2011 spanning the spring, summer, autumn and winter seasons. Water samples were collected from six sampling sites along Tyume River and analysed for total nitrogen, orthophosphate, biochemical oxygen demand (BOD), temperature, pH, dissolved oxygen (DO), electrical conductiv...

the physico-chemical parameters, nutrient status and heavy metal ions of huluka and alaltu rivers of ambo, ethiopia were studied. temperature, ph, electrical conductivity, co2 content, total dissolved solids, hardness, dissolved oxygen, ca2+, mg2+, cl-, nitrate, phosphate and sulphate have been determined along with selected heavy metals to assess the various water quality profiles along the ri...

The aim of this one-year study (August 2009 to July 2010) was to evaluate the Corumbataí River water polluted by anthropogenic sources and see how it affects the reproduction of the microcrustacean Ceriodaphnia dubia (Richard, 1984) in laboratory conditions over seven days of exposure to water samples collected monthly at six different locations. We determined the concentrations of zinc (Zn), c...

Remotely sensed data can reinforce the abilities of water resources researchers and decision makers to monitor waterbodies more effectively. Remote sensing techniques have been widely used to measure the qualitative parameters of waterbodies (i.e., suspended sediments, colored dissolved organic matter (CDOM), chlorophyll-a, and pollutants). A large number of different sensors on board various s...