Copper absorbance

The copper EXAFS of the ruthenium-copper clusters might be expected to differ substantially from the copper EXAFS of a copper on silica catalyst, since the copper atoms have very different environments. This expectation is indeed borne out by experiment, as shown in Figure 2 by the plots of the function K x(K) vs. K at 100 K for the extended fine structure beyond the copper K edge for the ruthenium-copper catalyst and a copper on silica reference catalyst ( ). The difference is also evident from the Fourier transforms and first coordination shell inverse transforms in the middle and right-hand sections of Figure 2. The inverse transforms were taken over the range of distances 1.7 to 3.1A to isolate the contribution to EXAFS arising from the first coordination shell of metal atoms about a copper absorber atom. This shell consists of copper atoms alone in the copper catalyst and of both copper and ruthenium atoms in the ruthenium-copper catalyst. 

Ammino-cuprous Iodides.—Cuprous iodide, like the other halides of copper, absorbs ammonia gas, forming ammino-compounds. If the iodide be saturated with ammonia gas at 0° C. two ammines appear to be formed, hexammino-cuprous iodide, [Cu2(NII3)6]I2, and triammino-cuprous iodide, [Cu2(NII3)3]I2. These are the only compounds formed according to Lloyd s examination by measuring change of pressure with change of composition. 

Molten copper absorbs several times its volume of sulphur dioxide, the product being a mixture of cuprous oxide and cuprous sulphide, which remains in solution in the metal.1 When dry, sulphur dioxide has no action on iron even at 100° C., but the metal is slightly attacked by the moist gas.2... 

Figure 3. Copper absorbance spectrum of galactose oxidase (775 nm not recorded) (----) and the enzyme in the presence of sodium azide (-). Spectra...

Molten copper absorbs hydrogen9 and sulphur dioxide,10 the occluded gases being eliminated on cooling. The liquid metal does not absorb nitrogen. It combines with oxygen to form cuprous oxide, so that fall of temperature is not attended by evolution of the gas. It decomposes hydrocarbons such as methane and ethane, with occlusion of hydrogen and separation of carbon. 

Hepatolenticular degeneration (Wilson s disease) is caused by a genetic failure to eliminate copper absorbed from food so that it accumulates in the liver, brain, cornea and kidneys. Chelating copper in the gut with penicillamine (p. 293) or trientine can establish a negative copper balance (with some clinical improvement if treatment is started early). The patients may also develop cirrhosis, and the best treatment for both may be orthotopic liver transplantation. 

After complete saturation of the copper-binding capacity of the liver, the copper absorbed from food can no longer be taken up by the liver. This means that copper is stored in the brain, skeletal system, heart, cornea and kidneys - as is also the case when copper stored in the hepatocytes is released into the circulation on a large scale due to extensive liver cell necrosis. (339)... 

The normal range of serum copper in the adult is 11 to 24 Urinary copper is normally about 20 jjg/day. This level is equivalent to 0.5 to 3.0% of copper intake. Most of the copper absorbed into the body is excreted by way of the bile and lost via the feces. About 1.7 mg of copper is excreted in bile per day this amount varies with the amount absorbed from the diet. This copper occurs complexed with protein and bilirubin. Bilirubin is a catabolite of heme. The copper is excreted in the bile and lends not to be absorbed back Into the body, There is little or no enterohepatic circulation of copper. The concentration of bile copper drops markedly with a copper deficiency, contributing to the conservation of this mineral by the body. 

Calculated concentrations are based on the diffusion equation for a semi-infinite medium (see text) and are given immediately under the experimental values. Diffusion coefficients are calculated from the total copper absorbed by the laminate stack. 

OEM Thermafin copper absorber plates and flat plate solar thermal collectors. Tel 1.800.874.2190... 

The ESR studies performed on the catalysts whose activity data are here in above presented show the existence of copper absorbed in the lattice under two forms which according to the literature data would be Cu2+ and Cu+. 

Although copper is as inherently toxic as many other heavy metals and is present in a number of tissues in concentrations at which many metals exhibit toxicity, copper toxicosis in human beings occurs only in about five individuals in a million. Except where suicidal attempts involve the ingestion of thousands of times the normal daily intake of copper, or where copper enters the body by other than the gasto-intestinal tract, copper toxicosis of man is seen solely in those individuals who inherit a pair of abnormal autosomal genes, the effect of which appears to be to impair a normal excretory route for copper absorbed in excess of what is metabolically essential. Copper toxicosis eventuates not merely because there is too much in the body, but because the excess is not Incorporated into specific copper proteins which would... 

Many different laser types have been developed for the treatment of different materials. The higher the absorption rate of the laser radiation, the faster the material can be heated. While some highly reflective materials (e.g. aluminium and copper) absorb short wavelengths best (e.g. Nd YAG/Neodynium Yttrium Aluminium Garnet or diode lasers), less reflective materials (e.g. iron and steel) can best be treated with lasers operating at longer wavelengths (e.g. CO2 lasers) (see Fig. 6.11). 

The practice of feeding high levels of copper to pigs appears to be possible because of the unusual ability of this animal to store copper in its liver, and at the levels of copper popularly fed (125-250 ppm dry matter), the relatively large amounts of copper absorbed from the intestine travel by way of the portal vein to the liver, where they are stored and thereby prevented from affecting... 

Replace the aluminium absorber (1335 mg cm ) by a copper absorber of the same thickness on the second shelf and count for 200 seconds. Repeat using instead of copper, lead absorbers of the same thickness. Repeat using an iron absorber instead. 

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