As many a coffee drinker knows, a drying drop of coffee typically leaves behind a ring-shaped stain of small grounds. Though the phenomenon is common, the mechanisms that drive it are rich with physics. As first elucidated by Robert Deegan and colleagues in 1997, the coffee ring results from radially outward fluid flows induced by so-called contact line pinning: The outer edge of a spilled coff...

Before 2001, the ecological protection area in the Kenting National Park (KTNP), southern Taiwan, was poorly described. In this study, a set of four-year data (2001-2004) of seawater qualities at 19 sampling sites around the Nanwan Bay in the KTNP was used to explore anthropogenic impacts to ecological environment, especially coral reefs. The parameters of water quality were analyzed immediatel...

A leaky dielectric Newtonian drop suspended in another leaky dielectric Newtonian liquid medium deforms as it settles under the influence of a uniform alternating electric field. As a result of this deformation, the terminal velocity is affected. In this study we present a detailed experimental investigation of the effect of horizontally directed uniform alternating electric field on the settli...

The application of syringe to syringe dispersive liquid phase microextraction-solidified floating organic drop was extended for the separation and preconcentration of trace amounts of cadmium ions from water and cereal samples. The extracted cadmium was quantified by electrothermal atomic absorption spectrometry. Factors affecting the complex formation as well as microextraction efficiency such...

in this work, an environmentally friendly sample pre-treatment method, ultrasound assisted surfactant enhanced emulsification microextraction (uaseme) followed with spectrofluorimetry was performed for determination of oxadiazon residues in water samples. after the determination of the most suitable extraction solvent and its volume, other parameters such as type and concentration of surfactant...

A method for the determination of trace amounts of the herbicide oxadiazon was developed using headspace solid-phase microextraction (HS-SPME), gas chromatography-mass spectrometry (GC-MS) and selected ion monitoring. It was applied to determine oxadiazon in ground water, agricultural soil, must, wine and human urine samples. To determine oxadiazon in liquid samples, a response surface methodol...

an efficient, rapid, simple, and highly selective dispersive liquid–liquid microextraction basedon solidification of floating organic drop (dllme-sfod), combined with flame atomicabsorption spectrometry was developed for preconcentration and determination of trace amountsof cobalt in water samples. in this method, an appropriate mixture of acetone and1-undecanol was injected rapidly into the aq...