Rotating copper

The Ni(II) complex of the hexaaza macrocyclic ligand 1 is reported to show a high activity for the electrocatalytic reduction of C02 to CO when a rotating copper disc electrode is used (85). In addition, water-soluble Niu-azacyclam complexes, 3a-3g, where R = carboxamide or sulfonamide, either aliphatic or aromatic, are found to be active in the electrocatalytic reduction of C02 at a mercury cathode. The efficiency is comparable to that of [Ni(cyclam)]2+ (14). 

Fig. 8. Model of cuprous acetate-quinolme-hydrogcn dimer structural formula II. X = hydrogen atoms attached to copper. (A) Hydrogen atoms close to one another (B) hydrogen atoms separated by rotating copper atoms.

Figure 24 Integrated intensity behavior of three satellite reflections versus exposure time in TTF-TCNQ at 13 K. With a rotating copper anode generator (12-kW Rigaku 200) an 0.5% intensity decrease per irradiation hour is observed. (From Ref. 40.)...

Rotating-copper-disk electrode techniques have been used to evaluate the efficiency of the nickel macrocycle catalyst for the reduction of CO2 to Studies have been performed using Ni(diazacyclam) + (diazacyclam = 3,10-dimethyl-1,3,5,8,10,12-hexaazacyclophane) (5.6), a complex derived from cy-clam, which appears to be more active than [Ni(cyclam)2] " under the same conditions (see Figure 5.70) . These results are consistent with a mechanism proposed by other authors - . ... 

The wet disks are immediately immersed into the vapor of refluxing isopropanol. Once they reach the reflux temperature, as noted by a reduction in the rate of alcohol condensation on the disks, they are removed into the room air where they rapidly become dry and slowly cool to room temperature. At this point, the disks are individually weighed to the nearest 0.1 mg. The disks are then loaded into a metal tray with large circular regions on their bottom faces exposed and the tray placed in the load lock of a vacuum chamber. The load lock is pumped to about 10 torr and then the tray is translated into the chamber and the load lock sealed off from the chamber. The chamber is pumped to about 10 torr with a cryopump. The major residual gas is water from the rotatable rubber seal used between the evacuated space in the chamber and the water flow path into and out of the rotatable copper crucible mentioned below. Titanium vapor is sublimed from a Ti ingot by bombardment with about 8 keV electrons while the periphery of the ingot is cooled by sparse physical contacts with the water-cooled copper crucible in which it rests. The Ti vapor condenses in the line of sight from the source onto the exposed bottoms of the disks. The thickness of the deposited titanium, is monitored by a calibrated quartz crystal balance close to the quartz disks. Typically (iji 5 x 10 cm. 

By rapid quenching of a suitable alloy from the melt at a cooling rate of about 10 -10 K/s, an amorphous metallic state will be produced where crystallization is suppressed. Commonly, casting through a slit nozzle onto a rotating copper wheel is used to form a ribbonshaped product. The thickness of the ribbons is typically between 20 and 40 p,m. 

Studies have been made on the rate of growth of oxide films on different crystal faces of a metal using ellipsometric methods. The rate was indeed different for (100), (101), (110), and (311) faces of copper [162] moreover, the film on a (311) surface was anisotropic in that its apparent thickness varied with the angle of rotation about the film normal. 

Markovic N M, Gasteiger H A and Ross P N 1995 Copper electrodeposition on Pt(111) in the presence of chloride and (bi)sulphate Rotating ring-Pt(111) disk electrode studies Langmuir 11 4098-108... 

Cholestenone. Place a mixture of 1 0 g. of purified cholesterol and 0-2 g. of cupric oxide in a test-tube clamped securely at the top, add a fragment of Dry Ice in order to displace the air by carbon dioxide, and insert a plug of cotton wool in the mouth of the tube. Heat in a metal bath at 300-315° for 15 minutes and allow to cool rotate the test-tube occasionally in order to spread the melt on the sides. Warm with a few ml. of benzene and pour the black suspension directly into the top of a previously prepared chromatographic column (1) rinse the test-tube with a little more benzene and pour the rinsings into the column. With the aid of shght suction (> 3-4 cm. of mercury), draw the solution into the alumina column stir the top 0 -5 cm. or so with a stout copper wire to... 

The cementation of gold and the purification of the ziac electrolyte ate usually carried out ia cylindrical vessels usiag mechanical agitation. The cementation of copper is carried out ia long narrow tanks called launders, ia rotating dmms, or ia an iaverted cone precipitator (see Copper). 

Roasting . Roasting has been largely abandoned ia modem copper smelters, ia which this function is combiaed with the smelting furnace. In older systems, the multiple-hearth roaster is a brick-lined tower having horizontal brick hearths. The concentrate is iatroduced at the top hearth, where rotating arms with rabble blades turn it over and move it to holes ia the hearth. The concentrate is transferred successively to lower hearths and finally... 

Barrel plating of parts in copper cyanide solutions utilizes various formulations, some weaker, some stronger than the high speed baths. When plating parts that tend to stick together or nest during the barrel rotation, the free cyanide may need to be increased. This may require 35—40 g/L free potassium cyanide or more with an equal copper content. 

The current in the copper ring opposes the main flux in that area of the pole and behaves like an artificial second winding, and develops a rotating field. Although the torque so developed is extremely low, it is enough to rotate such small drives, requiring an extremely low starting torque, of the order of 40-50% of the full load torque. 

Nine strips of pure, fully annealed copper were deformed plcistically by being passed between a pair of rotating rollers so that the strips were made thinner and longer. The increases in length produced were 1,10, 20, 30, 40, 50, 60, 70 and 100% respectively. The diamond-pyramid hardness of each piece was measured after rolling. The results were... 

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