A description is given of the parametric study done to evaluate the structural behavior of the replacement steel orthotropic deck planned for the Bronx—Whitestone Bridge in New York City. A principal objective was to analyze the deck details for stress ranges that indicated sensitivity to fatigue cracking. On the basis of the analysis findings, important modifications were made to the preliminary deck design. These changes were primarily to reduce the maximum stresses in the diaphragms and ribs around the diaphragm cutouts—locations that traditionally have been prone to cracking, as observed on orthotropic decks on other bridges. After the completion of the deck design, a full-scale prototype deck measuring 48 by 37 ft was fabricated and subjected to a series of laboratorycontrolled fatigue tests. Proper boundary conditions and loading procedures were created to produce stress ranges similar to those in the full bridge model. Laboratory test results correlated well with the computed stress ranges and demonstrated that the deck had outstanding fatigue resistance and could readily provide the 75-year design service life specified for the orthotropic deck.

The highly irreversible electrochemical oxidation of Sb(lll) at a platinum electrode in dilute HCI is electrocatalyzed by Ior l2 specifically adsorbed at the electrode surface. This phenomenon was applied for the determination of antimony in several standard alloys and in human hair by a highly sensitive and selective method using forced-flow liquid chromatography with a platinum coulometric detector. Because the electrolytic efficiency of the detector was 100%, the quantity of Sb(lll) in the samples was calculated directly from the integral of the current-time peak for Sb(lll) using Faraday's law. Use of a calibration curve was unnecessary.Johnson and Larochelle recently described a simple design for a tubular electrode (1). When packed with chips of platinum, the electrode can be operated with 100% electrolytic efficiency for a large range of fluid flow rates.

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