Ocean thermal energy: Potentials and pitfalls
Abstract Thermal energy in vast reaches of the world's oceans lies waiting to be tapped by a fuel‐hungry world. The United States— the one heavily industrialized nation with “OTEC”; waters lapping its shores—is actively developing the technology; Japan and a European consortium are also pressing forward. The resource may be of practical value soon to favorably situated islands (e.g., Hawaii, Puerto Rico, Cuba) and Third World countries. Meaningful contributions to mainland U.S. electricity needs are almost certainly a decade or more in the future, and conjectural. Environmental dangers loom if OTEC is too extensively and hurriedly deployed, and for the United States it is not a substitute for nuclear fission and fossil fuel in meeting immediate energy needs.
Ocean Energy: Forms and Prospects
The nature and distribution of power sources of the sea other than petroleum are discussed, along with possible entr�es for their use. Waves, tides, currents, and salinity and temperature gradients all have the potential to contribute useful power. Submarine geothermal sources, salt domes, ice, and other marine-associated concentrations may be more important. There are opportunities to employ these marine power resources directly rather than for contributions to power grids or power-intensive products. Ancillary employment of the seawater as a coolant and of the sediments below the seabed for the disposal of nuclear wastes may be even more important uses than employment of the power that the sea contains.
Electrochemical detection of copper(II) at a gold electrode modified with a self-assembled monolayer of penicillamine
A penicillamine (PCA) self-assembled monolayer (SAM) was prepared on a gold electrode. It has been found that the modified electrode exhibited a selective response to copper ions. As demonstrated by cyclic voltammetric experiments, the SAM-based electrode showed an attractive ability to preconcentrate efficiently traces of copper(II) from solutions. Under optimum conditions, the anodic peak current was proportional to the concentration of Cu(II) in the range from 8.0 × 10−7 to 1.0 × 10−4 M with a detection limit of 4.0 × 10−7 M. Moreover, this modified gold electrode is also characterized by excellent repeatability, showing a relative standard deviation of 3.2% for nine successive measurements of 1.0 × 10−5 M Cu(II). The PCA/Au SAM gold electrode was used for the determination of Cu(II) in a tap water sample and the results showed a good agreement with the data obtained by atomic emission spectrometry.