Copper Development Association Research Articles

Calculating Aqueous Environmental Quality Standards to Protect Human Health: Derivation of a Predicted No-Effect Concentration.

Efforts to establish water quality standards for the protection of human health involve a calculation of the amount of fish that can be consumed without exceeding a predetermined safe dose. This article is protected by copyright. All rights reserved.

Investigation of the Distribution of Lead in Three Different Combinations of Brass Feedstock

The main objective of this paper was to assess three leaded brass samples (pending application with Copper Development Association) using optical microscopy and mass spectrometry to compare the distribution of lead. Based on the mass spectrometry data, a great deal of variation was not found within each of the samples based on five different sample locations. Optical microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy confirmed that the lead was homogenously distributed in brass.

Can Copper Lower Infection Rates

Contamination of the hospital environment contributes to the acquisition of multidrug-resistant organisms and the development of hospital-acquired infections (HAIs) — a realization that has led to increasing emphasis on disinfection. But might changing surface materials also be beneficial? Two new studies suggest that the use of copper-alloy surfaces could be effective in decreasing HAIs. (One of the authors, who participated in both studies, is employed by the Copper Development Association.) Schmidt and colleagues compared the bacterial burden (BB) on copper-covered and …

Evaluation of the Elevated Temperature Creep Strength of Three Lead-Free Solder Alloys in Soldered Joints

Abstract Amendments to the Safe Drinking Water Act mandated that soldered joints used in potable water systems be free of lead. In addition to lead contents, allowable pressures used in potable water systems are directly related to the elevated temperature creep strengths of the soldered joints. The National Institute of Standards and Technology (NIST) and the Copper Development Association (CDA) investigated the stress rupture behavior of leadfree soldered joints at four temperatures and various applied stresses. An extensive statistical analysis involving maximum likelihood techniques was used to generate estimated threshold stresses (below which failure in the soldered joints did not occur) as a function of composition and temperature. The results of that study for three solder alloys are given.

Twenty-year progress report on the Copper Development Association do-it-yourself solar swimming pool heating manual and on the associated prototype heater

A prototype do-it-yourself solar swimming pool heater was built of copper parts in 1973, combining the solar collector and a copper roof of the flat seam type. It has now heated a pool in Pasadena, California successfully for over 20 years. During those years the associated do-it-yourself manual has been distributed to about 100,000 readers, who have used it to make an unknown number of heaters. Some have used the manual as the basis for a business, building repeated custom heater installations. The present paper represents a progress report.

Corrosion Commentary

TN38 materials for seawater pipeline systems. “Materials for Seawater Pipeline Systems” published by Copper Development Association, describes the factors that need to be taken into account when selecting materials for pipelines handling seawater in ships, offshore oil and gas platforms, desalination plants and shore‐based industry using seawater services.

Corrosion Commentary

Corrosion and antifreeze in solar collectors. We thought that the last word — of several million — had been said on corrosion problems and antifreeze solutions. But to prove us wrong the International Copper Development Association has just issued a report on a project they carried out (Project No.294A) on The Effects of Elevated Temperature Exposure on the Compatibility of Glycol Solutions with Metals Used in Solar Absorbers.

Atmospheric corrosion of clad palladium and palladium-silver alloys: film growth and contamination effects

Claddings of Pd, Pd-40 Ag and Pd-60 Ag on CA725 † † Copper Development Association, Inc., New York, N.Y. copper alloy, exposed for up to 40 months in certain air-conditioned telephone central offices, do not show significant film growth or surface contamination effects. When exposed for similar periods in a non-air-conditioned room of a central office, these claddings had dust particles containing salts of Ca, Na and Cl on a hydrated palladium dichloride film for Pd, and on a mixed hydrated PdCl 2 and silver chloride film for Pd-40 Ag and Pd-60 Ag. The growth rate of the chloride film was parabolic with rate constants of 1.11 × 10 −11 cm 2/month for Pd, 2.77 × 10 −12 cm 2/month for Pd-60 Ag and 5.82 × 10 −13 cm 2/month for Pd-40 Ag. The Pd-60 Ag alloy also reacted with other contaminants and was the most degraded with respect to total film growth, followed by Pd and Pd-40 Ag.

Information activities of Copper Development Association Inc., (U. S.) and Japan Copper Development Association

Information activities of Copper Development Association Inc., (U. S.) and Japan Copper Development Association

Stress Relaxation and Fatigue of Two Electromechanical Spring Materials Strengthened by Thermomechanical Processing

The reliable performance of electrical contacts often depends on the dimensional stability of the spring material used to operate these contacts. The fatigue and stressrelaxation behavior of two copper-base alloys, Copper Development Association Alloys 510 (5 percent tin phosphor bronze) and 725 (89%Cu-9%Ni-2%Sn), strengthened by thermomechanical processing has been investigated. Strengthening mechanisms resulting from a combination of cold work and low temperature heat treatment have been taken advantage cf to produce electromechanical spring materials which have good conductivity and corrosion resistance, have sufficient ductility forpunching and forming, are dimensionally stable for long periods of time and also adequately resist fatigue stressing. Test data are presented which show the materials processed in this manner to have significant advantages over currently available, commercial tempers in that they permit designs having higher working stresses and better material utilization, thus filling a need created by miniaturization.

Physical and Mechanical Properties of Electrodeposited Copper: III . Deposits from Sulfate, Fluoborate, Pyrophosphate, Cyanide, and Amine Baths

This paper is the third published report on the results of a broad program on properties of electrodeposited copper, sponsored jointly by the American Electroplaters' Society, The International Copper Research Association, Inc., The Copper Development Association, and the National Bureau of Standards. The first paper is a comprehensive review of the literature to 1965. The second paper is an interim report on experimental results. The present and final paper, which incorporates the data in the second, includes data from the baths designated in the title, for deposits prepared under a wide range of operating conditions and with use of a variety of addition agents. Properties measured include tensile strength, yield strength, elongation, modulus of elasticity, fatigue strength, hardness, internal stress, density, electrical resistivity, and thermal expansivity. Properties were measured for as‐plated deposits, deposits after annealing at several temperatures, after cold‐working, and at low and high ambient temperatures. Structure of deposits was examined by optical, electron micrograph, and x‐ray methods. Content of impurities in deposits was determined. Correlations are developed among properties, structure, impurity content, type of bath, and operating conditions.

Early Metallurgy

THE Royal Anthropological Institute has appointed a Mining and Metallurgical Committee to investigate problems 41 early metallurgy, as part of its scheme for group studies of the evolution of man. Among the fiit matters to be studied by the Committee is early use of copper. When found in its metallic form, the element is known as ‘native’ copper, and metal of this kind undoubtedly formed the earliest sources of copper supply. Samples from various parts of the world are being collected by the Committee and analysed with the object, if possible, of relating their particular composition to that of ancient specimens of copper work. The Committee includes the following: Mr. C. E. N. Bromehead (Geological Survey and Museum); Prof. V. Gordon Childe (Institute of Archaeology, London); Mr. H. H. Cogh-lan (chairman); Prof. C. H. Desch; Dr. Oliver Davies (Queen's University of Belfast); Mr. A. Digby (British Museum); Prof. C. F. C. Hawkes (University of Oxford); Dr. W. Lamb (secretary); Mr. T. K. Penniman (Pitt Rivers Museum, Oxford); Prof. Stuart Piggott (University of Edinburgh); Dr. H. J. Plenderleith (British Museum); Dr. J. Raftery (National Museum, Dublin); Mr. B. Webster Smith (Copper Development Association).

Earthing with Driven Copper Electrodes

A HUNDRED years ago, when electricity was usually generated by the use of frictional or Wimshurst machines and detected by gold leaf electroscopes, it was well known that an electric charge on a conducting surface could be dissipated by connecting the charged surface to earth. It is now found that owing to the increasing electric power behind modern networks, in order to get safe operation special attention, has,to be paid to the conductor connecting charged metallic objects to earth. Copper electrodes of small diameter cannot be driven with a sledge-hammer unless the ground be soft, as the rod will bend or the top will be deformed. The Copper Development Association of Thames House, Milbank, London, S.W.I, has published a booklet entitled “Copper for Earthing” which gives several useful hints on this problem. The most satisfactory method of driving copper electrodes into the earth is by means of an electric hammer which delivers a large number of light blows. The usual procedure is to choose the wettest or the most low-lying spot in the neighbourhood and drive a copper rod of small diameter into the earth to a depth of about eight feet. The earth resistance is then measured; if too high, several more rods can be driven in and connected in parallel. This is necessary for earthing mains where a possible fault current may be very large. The booklet points out that, even now, earth connexions are sometimes made by a few feet of conduit buried outside the house or under the floor in contact with a small iron plate or with the hot-water piping system. Sometimes even a large electric machine is earthed by binding the wire round a loose rock lying on the ground. In one case the earthing wire was found to terminate in a bottle of water !

Aluminium Bronze. Issued by the Copper Development Association. Pp. 151. London: Copper Development Association, 1938

Journal of the Society of Chemical IndustryVolume 58, Issue 18 p. 423-423 Reviews Aluminium Bronze. Issued by the Copper Development Association. Pp. 151. London: Copper Development Association, 1938 First published: 6 May 1939 https://doi.org/10.1002/jctb.5000581836AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume58, Issue186 May 1939Pages 423-423 RelatedInformation