Copper compared with silver

In vitro study shows increased antifungal activity of silver comparing with copper in the same concentration. 

On the other hand, if silver, silver/palladium, or gold are used as conductive material, it is not necessary to take deoxidation of the material into account since they can be fired in the air atmosphere, and a wide choice of materials is possible. Since it is not necessary to bear in mind driving off the binder as with copper materials explained above, the manufacturing process is simple. Silver and palladium are not entirely without problems, such as silver oxide due to low temperature oxidation diffusing into the glass, and dilation through oxidation of the palladium [15]. However, compared with copper, their problems are really insignificant. 

Photochromic silver—copper haUde films were produced by vacuum evaporation and deposition of a mixture of the components onto a sUicate glass substrate (13). The molar ratio of the components was approximately 9 1 (Ag Cu) and film thicknesses were in the range of 0.45—2.05 p.m. Coloration rate upon uv exposure was high but thermal fade rates were very slow when compared with standard silver haUde glass photochromic systems. 

This study relates to a continuous process for the preparation of perfluoroalkyl iodides over nanosized metal catalysts in gas phase. The water-alcohol method provided more dispersed catalysts than the impregnation method. The Cu particles of about 20 nm showed enhanced stability and higher activity than the particles larger than 40 nm. This was correlated with the distribution of copper particle sizes shown by XRD and TEM. Compared with silver and zinc, copper is better active and stable metal. 

In the effect of active metal, copper was more stable and active than silver and zinc. In the effect of particle size, the smaller particle is the more stable and active. It seems that the catalysts with smaller particle size have more active sites compared with those of larger particle size in same space. Through out the Fig. 3 and Table 2, in the effect of reaction... 

Sintered alloy films of reasonable thickness, e.g., opaque, mirrorlike films, can provide an adequate number of diffraction peaks for the determination of a lattice constant of adequate accuracy for present purposes. Thus, the apparent lattice constants calculated from the centroids of individual diffraction peaks, observed with a counter-diffractometer, may be extrapolated to 0 = 90°, using the Nelson-Riley function to give a value of a0. There has been some discussion about differences in lattice constants for thin films compared with bulk metals values of ao for pure silver films ( 1000 A nominal thickness) were found (74) to be consistently small compared with bulk silver but only by 0.05%. For alloy films a similar deviation would correspond to a variation of 1% in the composition of the alloy. Larger deviations have been reported for very thin films, e.g., —0.2% in copper films of 100 A nominal thickness (75).]... 

Using Resources Use resources such as the CRC Handbook of Chemistry and Physics, the Merck Index, or the Internet to determine the colors of silver metal and copper nitrate in water. Compare this information with your observations of the reactants and products in step 6. 

Standard textbooks normally paid little attention to gold chemistry compared with that of other metals, even other noble metals. This tendency has changed in the last two decades, with impressive development in its stoichiometric coordination and organometallic chemistry [2]. However, while platinum and palladium have been extensively used as catalysts for a long time, and copper and silver (partners of gold in the periodic table) are used in many large-scale processes, gold was not considered for these types of transformations [7]. 

Table 5), and several are now being used, or are potentially useful, for measuring key ocean elements. The most common use of direct potentiometry (as compared with potentiometric titrations) is for measurement of pH (Culberson, 1981). Most other cation electrodes are subject to some degree of interference from other major ions. Electrodes for sodium, potassium, calcium, and magnesium have been used successfully. Copper, cadmium, and lead electrodes in seawater have been tested, with variable success. Anion-selective electrodes for chloride, bromide, fluoride, sulfate, sulfide, and silver ions have also been tested but have not yet found wide application. 

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