Problems Silver

The recovery of silver from the solutions used in developing and fixing photographic film and prints presents just such a problem. Silver is an expensive metal, and the recovery is profitable. Moreover, if not recovered, the silver ions would constitute an undesirable pollutant in water supplies. 

Problem Silver is an element and therefore it is not possible to decompose it into different substances. It should not be possible for black silver , if one calls it an element, to decompose. If, however, one takes the black substance, which we find on silver cutlery, and intensely heats it, a silvery metal and a pungent smelling gas are produced silver and sulfur dioxide. This experiment shows also that the black substance is a compound silver sulfide. A similar experiment could be performed with black silver oxide, it decomposes to form silver and oxygen. 

Problem Silver (Ag Z = 47) has 46 known isotopes, but only two occur naturally, " Ag and Ag. Given the following mass spectrometric data, calculate the atomic mass of Ag ... 

In the early and mid-1960s, multilayer boards arrived on the scene, particularly for military uses, where cost was not an issue the premium was on compactness, weight, and reliability. These boards evolved with advances that occurred in metallizing and photoresist processes. Standards and specifications were prepared for conventional boards in the early 1960s, and in the latter part of that decade for multilayers. Because of migration problems, silver was permanently eliminated as a competitor for copper in metallizing circuit board holes. 

Problems Silver staining is complicated, takes a long time (1 to 2 h), is difficult to reproduce exactly, and it is not quantifiable because different proteins stain with different intensity (Poehling and Neuhoff 1981). In addition, the stained protein cannot be used for anything else (no blot, no elution, is quenched). In addition, the silver stain by no means targets proteins specifically, and it stains nucleic acids, lipopolysaccharides, bpids, and glycolipids. 

In the case of indoor antibacterial tiles, one has to keep in mind the possibility of accumulation of bacteria in areas either temporarily or permanently inaccessible to light. To overcome this problem, silver or copper metal particles have been deposited photocatalytically on catalyst surfaces [25]. These metals are widely used as antimicrobial agents. Either of the metal solutions is sprayed on the... 

Nitroethane and 1-(3,4 methylenedioxy) 2- nitropropane This method of producing the above mentioned nitro compounds is by far the best Ritter has come across yet The problem with standard nitroethane synthesis is that the -NO2 source most commonly used is silver nitrite (a la Merck Index citing). Needless to say, this is going to be an expensive compound to make as it is not available commercially but must be synthesized from costly silver nitrate. The other methods mentioned in Vogels 5th masterpiece... 

Selectivity Due to the chemical nature of the precipitation process, precipitants are usually not selective for a single analyte. For example, silver is not a selective precipitant for chloride because it also forms precipitates with bromide and iodide. Consequently, interferents are often a serious problem that must be considered if accurate results are to be obtained. 

Deteriora.tlon. Apart from physical damage that can result from carelessness, abuse, and vandaUsm, the main problem with metal objects Hes in thek vulnerabihty to corrosion (see Corrosion and corrosion control) (127,128). The degree of corrosion depends on the nature and age of the object. Corrosion can range from a light tarnish, which may be aesthetically disfiguring on a poHshed silver or brass artifact, to total mineralization, a condition not uncommon for archaeological material. 

Hydrogen sulfide has traditionally been a problem in the tarnishing of silver and the discoloration of bronze patinas. This gas can be dealt with in the filters of the climate-control system as well as through the use of proper absorbing agents. For example, a paper treated with activated charcoal is fabricated especially for absorbing H2S within a microclimate. 

Silver on Diai Plates. Sdvet hahde has high photographic speed and a highly developed sensitizing and stabilizing technology. The principal problem... 

Air. Studies have shown that 2500 years ago lead pollution caused by Greek and Roman silver smelters was a significant problem (4). Based on analysis of lake sediments and Greenland s ice, it was found that lead contamination from smelters in southern and central Europe was carried throughout the northern hemisphere. As long ago as the thirteenth century, air pollution has been linked to the burning of coal (4). The main concern was the smell from the sulfur in the coal and the effects of the soot. It was not until many years later that the effects of air pollution on people s health were discovered. 

Silver—Iron Cells. The silver—iron battery system combines the advantages of the high rate capabiUty of the silver electrode and the cycling characteristics of the iron electrode. Commercial development has been undertaken (70) to solve problems associated with deep cycling of high power batteries for ocean systems operations. 

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