Silver quick

Synonyms liquid silver quick silver hydrargyrum Rathje Marcero... 

The Model 412 PWR uses several control mechanisms. The first is the control cluster, consisting of a set of 25 hafnium metal rods coimected by a spider and inserted in the vacant spaces of 53 of the fuel assembhes (see Fig. 6). The clusters can be moved up and down, or released to shut down the reactor quickly. The rods are also used to (/) provide positive reactivity for the startup of the reactor from cold conditions, (2) make adjustments in power that fit the load demand on the system, (J) help shape the core power distribution to assure favorable fuel consumption and avoid hot spots on fuel cladding, and (4) compensate for the production and consumption of the strongly neutron-absorbing fission product xenon-135. Other PWRs use an alloy of cadmium, indium, and silver, all strong neutron absorbers, as control material. 

In secondary wastewater treatment plants receiving silver thiosulfate complexes, microorganisms convert this complex predominately to silver sulfide and some metallic silver (see Wastes, INDUSTRIAL). These silver species are substantially removed from the treatment plant effluent at the settling step (47,48). Any silver entering municipal secondary treatment plants tends to bind quickly to sulfide ions present in the system and precipitate into the treatment plant sludge (49). Thus, silver discharged to secondary wastewater treatment plants or into natural waters is not present as the free silver ion but rather as a complexed or insoluble species. 

Electroless reactions must be autocatalytic. Some metals are autocatalytic, such as iron, in electroless nickel. The initial deposition site on other surfaces serves as a catalyst, usually palladium on noncatalytic metals or a palladium—tin mixture on dielectrics, which is a good hydrogenation catalyst (20,21). The catalyst is quickly covered by a monolayer of electroless metal film which as a fresh, continuously renewed clean metal surface continues to function as a dehydrogenation catalyst. Silver is a borderline material, being so weakly catalytic that only very thin films form unless the surface is repeatedly cataly2ed newly developed baths are truly autocatalytic (22). In contrast, electroless copper is relatively easy to maintain in an active state commercial film thicknesses vary from <0.25 to 35 p.m or more. 

Selective gas permeation has been known for generations, and the early use of p adium silver-alloy membranes achieved sporadic industrial use. Gas separation on a massive scale was used to separate from using porous (Knudsen flow) membranes. An upgrade of the membranes at Oak Ridge cost 1.5 billion. Polymeric membranes became economically viable about 1980, introducing the modern era of gas-separation membranes. Hg recoveiy was the first major apphcation, followed quickly by acid gas separation (CO9/CH4) and the production of No from air. 

Much care had to be taken during the TEM observations of silver nitrate filled tubes, because this salt is very sensitive to electron irradiation and the continuous filaments transformed quickly into a chain of silver particles (see Fig. 5) [22]. 

Pipette 25 mL of the standard 0.1 M silver nitrate into a 250 mL conical flask, add 5mL of 6M nitric acid and 1 mL of the iron(III) indicator solution. Run in the potassium or ammonium thiocyanate solution from a burette. At first a white precipitate is produced, rendering the liquid of a milky appearance, and as each drop of thiocyanate falls in, it produces a reddish-brown cloud, which quickly disappears on shaking. As the end point approaches, the precipitate becomes flocculent and settles easily finally one drop of the thiocyanate solution produces a faint brown colour, which no longer disappears upon shaking. This is the end point. The indicator blank amounts to 0.01 mL ofO.lM silver nitrate. It is essential to shake vigorously during the titration in order to obtain correct results. ... 

In order to silver Dewar flasks the jacket is cleaned and filled about two thirds full with the prepared solution. The Dewar should be rolled or shaken during the severing. The end-point is determined by occasionally pouring out a little of the solution, and when a flocculent precipitate is formed the solution should be removed from the flask as quickly as possible to prevent blooming. The flask is then cleaned and dried. If the glass is first etched with a dilute solution (about 0-7 molar) of hydrofluoric acid before its final cleaning, the... 

Lind (1961) defines radiation chemistry as the science of the chemical effects brought about by the absorption of ionizing radiation in matter. It can be said that in 1895, along with X-rays, Roentgen also discovered the chemical action of ionizing radiation. He drew attention to the similarity of the chemical effects induced by visible light and X-rays on the silver salt of the photographic plate. This was quickly followed by the discovery of radioactivity of uranium by Becquerel in 1896. In 1898, the Curies discovered two more radioactive elements—polonium and radium. 

Most substances expand when heated and contract when cooled, but liquid mercury shows an especially large variation of volume with temperature. That is why it is so often used in thermometers and barometers. Mercury also mixes with a number of metals to form alloys called amalgams. Amalgam is a special name given to alloys of mercury. With silver it forms a silver amalgam, which quickly hardens. This is the silver filling used by dentists. 

This epoxide to aldehyde rearrangement was postulated to be the first step in the silver-mediated reaction of alkylzirconocene chlorides with epoxides, in which the aldehyde is subsequently alkylated by the alkylzirconocene species (cf. Scheme 8.44) [56], In a control experiment, it was shown that zirconocene dichloride (1 equivalent or less) and silver (catalytic amounts) do indeed induce the rearrangement of an epoxide to an aldehyde very quickly. 

A 1-1., four-necked, round-bottomed flask equipped with reflux condenser, sealed stirrer, thermometer, and solid addition funnel and protected from atmospheric moisture with a Drierite guard tube is carefully dried and flushed with a dry inert gas (Note I). The flask is charged with 453 g. (3.1 moles) of silver difluoride (Note 2) and 500 ml. of l,l,2-trichloro-l,2,2-trifluoroethane (Note 3), and phenyl disulfide (100 g., 0.458 mole) (Note 4) is weighed into the solid addition funnel. The stirrer is started, and phenyl disulfide is added to the slurry in small portions. An exothermic reaction occurs, and after the addition of several portions the reaction mixture reaches a temperature of 40° (Note 5). By intermittent use of a cooling bath and by adjusting the rate of addition of the disulfide, the reaction temperature may be maintained between 35° and 40°. The addition of the phenyl disulfide requires 45-60 minutes. On completion of the addition the suspension of black silver difluoride has been converted to yellow silver monofluoride, and the exothermic reaction gradually subsides. The reaction mixture is stirred for an additional 15-30 minutes without external cooling and then quickly heated to reflux. 

Calomel is the old-fashioned name for mercurous chloride, Hg2CI2. Calomel was a vital commodity in the Middle Ages because it yields elemental mercury ( quick silver ) when roasted the mercury was required by alchemists. 

The technological information derived from a study of the early jettons can be summarized quite simply - before ca. AD 1450, European jettons contained on average around 4% tin and 1-2% lead, with a low zinc content, typically less than 10%. Traces of antimony, silver and arsenic are often present at 0.1- 02%. Nickel is very low, usually less than 0.05%. After AD 1450, the zinc content rises quickly to over 20%, with a corresponding fall in the lead (less than 1%) and tin (less than 0.2%). The trace elements are usually less than 0.1%, with the exception of nickel, present up to 0.5%. The combined copper plus zinc total is usually greater than 97%. 

Experiment 1.—Dilute a few drops of formaldehyde or acetaldehyde with a few c.c. of water, add a small amount of ammoniacal silver solution, and divide the mixture between two test tubes. Into one test tube run a few drops of sodium hydroxide solution an immediate separation of metallic silver takes place. From the other solution after standing for some time in the cold, or more quickly on warming, the silver separates. Thus the oxidising action of ammoniacal silver solution is very considerably increased by sodium hydroxide (Tollens). Also test the reducing action of the aldehydes on Fehling s solution. 

Chemical agent is mixed with concentrated nitric acid and silver nitrate. Ag2+ generated by the electrochemical cells quickly oxidizes the agent,... 

The effect of salt is to fix or volatilize, according as it is prepared and used. For the spirit of the salt of tartar, if extracted by itself without any addition, has power to render all metals volatile by dissolution and putrefaction, and to dissolve quick or liquid silver into the true mercury, as my practical directions shew. 

Cagliostro showed no outward concern. He d begin, he said, with a demonstration of the relatively quick and straightforward transmutation of mercury to silver. On 7 June 1780, he assembled the Masons at the manor house to perform the operation under their eyes. In shirtsleeves for ease of working, both he and Moczynski also wore full aprons to protect them-... 

And again "I am constrained to believe that there is the Stone which makes Gold, and which makes Silver because I have at distinct turns, made projection with my hand, of one grain of the Powder, upon some thousand grains of hot Quick-silver and the buisiness sic succeeded in the Fire, even as Books do promise a Circle of many People... 

The most beautiful metals, such as silver and gold, can also be the most expensive. Unfortunately, pure gold is soft, and pure silver tarnishes quickly. 

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