INDEX copper

Copper Corrosion Study. F. Romero, California State University—Dominguez Hills, http //tardis.csudh.edu/fromero/chemistry/copper/index.html... 

Copper Value (Copper Index or Copper Number) of Cellulose It represents the amt of Cu reduced from the cupric to cuprous state in alkaline sola by lOOg of cellulose (such as cotton). In case of cotton, it gives an indication as to whether any appreciable changes have taken place during purification proceduresjin case of woodpulp, it indicates the degree of purity. Accdg to Doree (Ref 4 pp 26 32-3)>normal cotton cellulose has copper values below 0.2 while sulfite pulp has value>2. The alpha-cellulose obtd from sulfite pulp had a value of 0,8... 

Figure 3.401. Dependence of the heating period on viscosity (t /c) of cryolised starch solution 2) redaction capacity - copper index of cryolised starch 3) Jc of starch soluble fractions obtained after cryolisis [1178],...

Figure 3.402. Dependence of the copper index of the water-soluble starch fraction 1) starch cryolised in the presence of air 2) starch cryolised in argon atmosphere [1178],...

Copper Development Association P.O. Box 1840 Greenwich, Conn. 06836 Standards for wrought and cast copper and copper alloy products a standards handbook is pubUshed with tolerances, alloy data, terminology, engineering data, processing characteristics, sources and specifications cross-indexes for six coppers and 87 copper-based alloys that are recognized as standards. 

Sa.tura.tion Index. Materials of constmction used in pools are subject to the corrosive effects of water, eg, iron and copper equipment can corrode whereas concrete and plaster can undergo dissolution, ie, etching. The corrosion rate of metallic surfaces has been shown to be a function of the concentrations of Cl ,, dissolved O2, alkalinity, and Ca hardness as well as buffer intensity, time, and the calcium carbonate saturation index (35). 

The Colour Index (up to June 1991) Hsts 21 direct violets with disclosed chemical constitutions. Commercially important are Cl Direct Violet 9 [6227-14-1] (79) (Cl 27885) (sulfanihc acid coupled to cresidiue followed by alkaline coupling to V-phenyl J-acid) and Cl Direct Violet 66 [6798-03-4] (80) (Cl 29120) (a copper complex of 2-arniao-l-phenol-4-sulfonarnide (2 mol) coupled to 6,6 -imiQobis-l-naphthol-3-sulfonic acid). 

Purified monomer is usually inhibited before shipment by such materials as copper resinate, diphenylamine or hydroquinone, which are generally removed before polymerisation. The monomer is a sweet-smelling liquid partially miscible with water and with the following properties boiling point at 760mmHg, 72.5°C specific gravity at 20°C, 0.934 refractive index 1.395 vapour... 

There are some aspects in the raw dry NR grades for adhesive manufacturing to be considered. NR tends to suffer oxidative degradation catalyzed by metals (mainly copper). The susceptibility of NR to oxidation can be measured using the plasticity retention index. The better grades of rubber have the higher plasticity retention index. 

The aim of the present paper is to extent the previous work " to different adsorbate than the substrate. We have thus studied the vibrational properties of Au single adatoms on the low-index faces of copper, and compared the present results with the above studies. The choice of Au comes from the fact that the Cu-Au alloys have been widely studied and used as prototype by many groups. 

We have studied the vibrational properties of Au adatoms on the low-index faces of copper. From the position of new phonon modes, which are due to the presence of the adatom, it comes out that the gold adatom is weakly coupled with the atoms of Cu(l 11) for the directions parallel to the surface and tightly bound with those of Cu(lOO). These modes are found in lower frequencies than those of the Cu adatom. The temperature dependence of MSD s and relaxed positions of the Au adatom along the normal to the surface direction, reveal that this atom is more tightly bound with the (111) face and less with the (110) face. 

The effect of pH on the corrosion of zinc has already been mentioned (p. 4.170). In the range of pH values from 5 -5 to 12, zinc is quite stable, and since most natural waters come within this range little difficulty is encountered in respect of pH. The pH does, however, affect the scale-forming properties of hard water (see Section 2.3 for a discussion of the Langelier index). If the pH is below the value at which the water is in equilibrium with calcium carbonate, the calcium carbonate will tend to dissolve rather than form a scale. The same effect is produced in the presence of considerable amounts of carbon dioxide, which also favours the dissolution of calcium carbonate. In addition, it is important to note that small amounts of metallic impurities (particularly copper) in the water can cause quite severe corrosion, and as little as 0-05 p.p.m. of copper in a domestic water system can be a source of considerable trouble with galvanised tanks and pipes. 

The procedure utilises eriochrome blue black RC (also called pontachrome blue black R Colour Index No. 15705) at a pH of 4,8 in a buffer solution. Beryllium gives no fluorescence and does not interfere iron, chromium, copper, nickel, and cobalt mask the fluorescence fluoride must be removed if present. The method may be adapted for the determination of aluminium in steel. 

Carbon monoxide chemisorption was used to estimate the surface area of metallic iron after reduction. The quantity of CO chemisorbed was determined [6J by taking the difference between the volumes adsorbed in two isotherms at 195 K where there had been an intervening evacuation for at least 30 min to remove the physical adsorption. Whilst aware of its arbitrariness, we have followed earlier workers [6,10,11] in assuming a stoichiometry of Fe CO = 2.1 to estimate and compare the surface areas of metallic iron in our catalysts. As a second index for this comparison we used reactive N2O adsorption, N20(g) N2(g) + O(ads), the method widely applied for supported copper [12]. However, in view of the greater reactivity of iron, measurements were made at ambient temperature and p = 20 Torr, using a static system. 

Chang S-C, Weaver MJ. 1991. Influence of coadsorbed bismuth and copper on carbon monoxide adlayer stmctures at ordered low-index platinum-aqueous interfaces. Surf Sci 241 11-24. 

ICA, Copper Connects Life, The International Copper Association, Ltd., New York, NY, available at http //www.copperinfo.org/aboutica/index.html, 2007. 

Table 2.2 contains mean values of the Cu—Oz bond lengths ((<7Cu—())), copper valence index [11] (FCu) and partial charge (<2Cu), one-electron energies of the HOMO and LUMO ( HOmo> lumo) levels along with the bonding energy of Cu1 to the hosting cluster. 

From the comparison of the results, it can be inferred that copper ions exchanged in the ZSM-5 zeolites assumes a bidentate (sites 12 and II) or tridentate coordination (sites M5, Z6, and M7). These two groups differ also in the molecular properties (Table 2.2). The I-centers are characterized by lower values of the valence index and greater partial charges, QCu, in comparison to the M and Z centers, which is associated with the deeper laying HOMO and LUMO levels. In the M5, Z6, and M7 sites Cu1 ions exhibit more covalent character, and the frontier orbitals have less negative energies. As a result, the chemical hardness of the I-centers, located at the channel intersections, is smaller than those located on the walls of the ZSM-5 zeolite. 

Stranski-Krastanov growth has been documented for copper on Au(lll) [101, 102], Pt(100) and Pt(lll) [103], for silver on Au(lll) [104, 105], for cadmium on Cu(lll) [106] and for lead on Ag(100) and Ag(lll) [107-109]. In all of these examples, an active metal is deposited onto a low-index plane of a more noble metal. Since the substrate does not undergo electrochemical transformations at the deposition potential, a reproducible surface can be presented to the solution. At the same time, the substrate metal must be carefully prepared and characterized so that the nucleation and growth mechanisms can be clearly identified, and information can be obtained by variation of the density of surface features, including steps, defects and dislocations. 

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