chromium(III) up to 100 ng mL−1, and for chromium(VI) up to 200 ng mL−1) were obtained, using the “fixed time” method with detection limits of 4.9 ng mL−1 and 3.8 ng mL−1, respectively. The results suggest that at the reaction conditions chromium(VI) is reduced and chromium(III) is oxidized to an intermediate oxidation state and the catalytic action of chromium is due to the formation of an act...

We develop a spectral representation formalism to calculate the Casimir force in the non-retarded limit, between a spherical particle and a substrate, both with arbitrary local dielectric properties. This spectral formalism allows one to do a systematic study of the force as a function of the geometrical variables separately from the dielectric properties. We found that the force does not follo...

A method to make two types of hinges which bend toward opposite directions from the same epitaxial layers using the micro-origami technique is proposed and successfully applied to make standing micro-stages on a GaAs substrate. This method opens a path to fabricate more complex three-dimensional self-positioned micro-machined structures. q 2003 Elsevier Science Ltd. All rights reserved.

an increase in the red cell's normal substrate, glucose, can produce changes in red cell metabolism.

According to the cognitive substrate hypothesis, human intelligence arises from the integration of specialist parts that are mostly shared with other mammals. In order for such specialists to cooperate in novel situations, however, they must agree on a system of signals that can describe aspects of the new situation using relations between familiar elements. This poses a problem because many si...

Fishers have been complaining about the effects of bottom trawl gear on the marine environment since at least the 14th century. Trawl gear affects the environment in both direct and indirect ways. Direct effects include scraping and ploughing of the substrate, sediment resuspension, destruction of benthos, and dumping of processing waste. Indirect effects include post-fishing mortality and long...

In this paper, we show how surface-micromachined buckled cantilevers can be used to construct out-of-plane structures. We include the relevant theory necessary to predict the height and angle of plates attached to buckled cantilevers, as well as the mechanical stresses involved in assembly. These platforms can be assembled to any angle between 0◦ and 90◦ with respect to the substrate by changin...

Biodegradation of phenol in the presence of glucose as a supplementary substrate was investigated with mixed microbial consortium isolated from waste effluent of coke-steel factory. Batch experiments were carried out at room temperature and pH value of 7. Initial phenol and glucose concentrations were in the range of 25-1000 mg/l and 500-3000 mg/l, respectively. In a dual substrates system the ...

In this work, we develop methods for controlling multiple untethered magnetic micro-robots (Mag-μBots) without the need for a specialized substrate. We investigate Mag-μBots that are geometrically and magnetically designed to respond uniquely to the same input magnetic fields. Designs include: (1) geometrically similar Mag-μBots with different values of magnetization, (2) geometrically dissimil...