Littérature scientifique sur le sujet « Galvanic caps »

The basic data on the volume of the formation of household (municipal) metal-containing waste, in particular, aluminum cans for drinks, cans, waste electrical and electronic equipment, electrical power sources (batteries and galvanic cells), as well as lighting lamps. The main methods of handling the indicated waste are considered and their critical analysis is presented. Particular attention is paid to the recycling and disposal of common waste such as waste electrical and electronic equipment, chemical sources of electrical current, and lighting lamps. Taking into account the rapid growth in the consumption of electrical and electronic products, it is shown that now there is a tendency not so much to improve the methods of disposal of the corresponding waste, but to ensure the production of more durable goods that provide for the possibility of their repair. A gradual transition from the 3R strategy (Reuse, Reduce, Recycle) to the 10R strategy (Refuse, Rethink, Reconsider, Reuse, Repair, Refurbish, Remanufacture, Repurpose, Recycle, Recover) is proposed. At the same time, the development of effective technologies for extracting not only traditional iron, aluminum, copper and their alloys from metal-containing household waste is not removed from the agenda, but also more scarce metals, including rare earth and heavy metals, as well as platinum group metals, which will allow significantly reduce the man-made load on the environment. Bibl. 69, Table 1.

A new intraoral luting technique between electroformed galvanic gold caps (AGC) and a metallic framework for a Cement-retained Implant-supported Metal-resin-fixed Complete-denture (CIMC) is presented. The peculiarity is the different prosthetic design with the metallic framework that is 1.5 mm shorter than the margin of the galvanic caps. As a consequence, the conventional thick prosthesis margin (AGC, cement for the luting phase, framework)is modified into a thin AGC prosthesis seal (0,3 mm) just beyond the apical limit of the aesthetic material. Passive fit is achieved during the intraoral luting phase between the framework and the galvanic caps. In this retrospective study we analyzed the periodontal response (plaque index and sulcus bleeding index) between patients treated with the conventional technique and patients treated with the new technique. The results (36 months followup) show that the new prosthetic techniques allows better periodontal health and in both groups, according to Literature, we found a positive correlation between plaque index and sulcus bleeding index. In conclusion, the new procedure is efficient, standardized, and enhances aesthetics and periodontal health.

Most metals used by our society corrode, from the mild tarnish on silver to the green patina that coats our copper statues and electrical wiring to the red rust on our cars and iron bridges (Fig. 12.1, Plate 17). Metal corrosion often involves the conversion of metals into either oxides or their soluble hydrolysis products. The metals we use in our structures, as well as in electronic and magnetic devices, are destroyed as a result of this conversion. It has been estimated that the annual cost of metallic corrosion to the U.S. economy is hundreds of billions of dollars (5% of the gross national product). Therefore, enormous efforts have been made to understand why metals corrode, and what can be done to inhibit corrosion processes. Stainless steel is just one example of humankind’s attempts to limit corrosion processes. Other examples include the use of inert paints on ships to prevent saline corrosion, coating iron with zinc to galvanize it, and exploiting electrochemical strategies, such as using sacrificial anodes that corrode instead of iron, as a means of protecting more important materials’ components. The number of comprehensive texts and reviews regarding metal corrosion scales with its economic impact, with more than 1000 articles being published on the topic per year. Those of you interested in more comprehensive discussions regarding how specific metals corrode in specific environments such as seawater and acid rain should see other works. Our focus in this chapter is to highlight how metal corrosion is mediated by the presence of oxides, with an emphasis on reactions that occur in water. This overview highlights the basic properties of oxide films that give rise to a wide range of complicated metal corrosion phenomena. The discussion draws on many concepts highlighted in other chapters of this book: surface chemistry (Chapter 6), electrochemistry (Chapter 11), and oxide dissolution (Chapter 16). Metal corrosion often involves electrochemical reactions in which the metal is oxidized by either water or O2.

Turbine compressor coatings are evaluated for use in acidified environments. In such environments, field performance shows poor correlation to results of neutral salt spray tests (ASTM B117). Tests which might better describe these low pH atmospheres are described and the copper accelerated acetic acid salt spray (ASTM B368) is selected as the most useful development tool. In addition, combining CASS exposure with thermal cycling is shown to be a useful procedure to further differentiate coatings for use in acidic environments. It is shown that, unlike the neutral salt spray, in CASS, highly sacrificial (i.e., galvanic) aluminum-filled ceramic overlay coatings fail more rapidly than do non sacrificial materials. Conventional barrier films represented by high performance polymeric coatings are prone to severe blistering in these acidic conditions. Preferred acid resistant coatings are described.

This study is the first stage of a research program aimed at understanding differences in how people process 2D and 3D automotive stimuli, using psychophysiological tools such as galvanic skin response (GSR), eye tracking, electroencephalography (EEG), and facial expressions coding, along with respondent ratings. The current study uses just one measure, eye tracking, and one stimulus format, 2D realistic renderings of vehicles, to reveal where people expect to find information about brand and other industry-relevant topics, such as sportiness. The eye-gaze data showed differences in the percentage of fixation time that people spent on different views of cars while evaluating the “Brand” and the degree to which they looked “Sporty/Conservative”, “Calm/Exciting”, and “Basic/Luxurious”. The results of this work can give designers insights on where they can invest their design efforts when considering brand and styling cues.