The unprecedented economies of scale and unique mass transport properties of microfluidic devices made them viable nano-volume protein crystallization screening platforms. However, realizing the full potential of microfluidic crystallization requires complementary technologies for crystal optimization and harvesting. In this paper, we report a microfluidic device which provides a link between c...

   In this study, cadmium sulfide nanoparticles (CdS NPs) were prepared, characterized and used as a new adsorbent for simultaneous removal of Pb(II) and Cu(II) ions from aqueous solutions. Using a batch adsorption method, the effects of solution pH, contact time, adsorbent dose, and temperature were studied and optimized. Removal efficiencies, higher than 98% were obtained for both the met...

We studied the kinetics of the reaction between cholesterol and sulfuric acid in acetic acid-acetic anhydride medium. Results have been used to establish near-optimal conditions for the fast kinetic determination of cholesterol in serum. The reaction rate measured during the first 20 s of the reaction is proportional to cholesterol concentration. There is good agreement (<2% deviation) between ...

This technical note describes kinetic fluorescence as an analytical technique to quantify non-fluorescent species. The technique is applied to the determination of thiamine (vitamin B1) in solution. Fluorescence intensity is monitored as thiamine converts to fluorescent thiochrome, and a relationship is established between the rate of increase of intensity and the concentration of thiamine. The...

The H-point standard addition method (HPSAM), based on a spectrophotometric measurement for the simultaneous determination of hydrazine and acetylhydrazine, is described. This method is based on the difference between the rates of their reactions with N,N-dimethylaminobenzaldehyde (DAB) in the presence of sodium dodecyl sulfate (SDS) in acidic media. The results showed that hydrazine and acetyl...

A new kinetic method for the determination of Hg(II) based on its inhibitory effect on the Brilliant green-sulfite reaction at pH 6.5 is proposed. The reaction is followed spectrophotometrically at 615 nm by measuring the change in absorbance at the fixed time of 3.5 min after the initiation of the reaction. Both the influence of the reaction variables and the interference of many ions have...

The new generation of centrifugal parallel fast analyzers, such as the “CentrifiChem,” is generally thought of primarily as enzyme analyzers, because of the several attractive characteristics they possess for such assays. With them, one can make an initial reading within several seconds of starting a reaction. They therefore can also be used to determine the concentration of selected compounds,...

To quantify the effect of wave breaking turbulence on sediment transport in the nearshore, the vertical distribution of time-averaged suspended sediment concentration (SSC) in the surf zone was parameterized in terms of the turbulent kinetic energy (TKE) at different cross-shore locations, including the bar crest, bar trough, and inner surf zone. Using data from a large-scale laboratory experim...