Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Copper monitoring

Tyrrell E., Gibson C., MacCraith B.D., Gray D., Byrne P., Kent N., Burke C., Pauli B., Development of a micro-fluidic manifold for copper monitoring utilising chemiluminescence detection, Lab on a Chip 2004 4 384-390. [Pg.214]

If one wants to understand why such changes occur, one can look at a few of the basic equilibrium properties of such complexes. Figure 1 illustrates the trends which occur when a sample is titrated with copper, monitoring three different parameters. The black dots indicate the relative amount of bound copper as indicated by free copper ions sensed with an ion-selective electrode (Xc of left ordinate). The triangles represent the change of the absorbance of the solution at 465 nm (right ordinate). The curve with the open circles is the relative quenching of the fulvic acid fluorescence (Q of left ordinate). We see that we are able to probe several different types of sites with different types of probes for this multidentate system. [Pg.43]

B92004 Lead and Copper Monitoring Guidance for Water Systems Serving 101 to 500 Persons... [Pg.219]

To remove possible surface contamination, some samples were chemically etched after irradiation for 2 to 5 min, depending on the silicon concentration, in a 1/1 (v/v) mixture of 14 M nitric acid and 50 % hydrofluoric acid at room temperature. A 20 m surface layer was removed. The copper monitor foil and the removed surface layer degraded the energy to 20 MeV. [Pg.374]

Acetylene has a low solubiHty in Hquid oxygen. Excessive concentrations can lead to separation of soHd acetylene and produce accumulations that, once initiated, can decompose violently, detonating other oxidizable materials. Acetylene is monitored routinely when individual hydrocarbons are determined by gas chromatography, but one of the wet classical methods may be more convenient. These use the unique reaction of acetylene with Ilosvay s reagent (monovalent copper solution). The resulting brick-red copper acetyHde may be estimated colorimetricaHy or volumetricaHy with good sensitivity (30). [Pg.480]

Fig. 4. Examples of emission spectrometry as a diagnostic monitoring tool for plasma processing, (a) The removal of chlorine contamination from copper diode leads using a hydrogen—nitrogen plasma. Emissions are added together from several wavelengths, (b) The etching and eventual removal of a 50-p.m thick polyimide layer from an aluminum substrate, where (x ) and (° ) correspond to wavelengths (519.82 and 561.02 nm, respectively) for molecular CO2... Fig. 4. Examples of emission spectrometry as a diagnostic monitoring tool for plasma processing, (a) The removal of chlorine contamination from copper diode leads using a hydrogen—nitrogen plasma. Emissions are added together from several wavelengths, (b) The etching and eventual removal of a 50-p.m thick polyimide layer from an aluminum substrate, where (x ) and (° ) correspond to wavelengths (519.82 and 561.02 nm, respectively) for molecular CO2...
Analysis of zinc solutions at the purification stage before electrolysis is critical and several metals present in low concentrations are monitored carefully. Methods vary from plant to plant but are highly specific and usually capable of detecting 0.1 ppm or less. Colorimetric process-control methods are used for cobalt, antimony, and germanium, turbidimetric methods for cadmium and copper. Alternatively, cadmium, cobalt, and copper are determined polarographicaHy, arsenic and antimony by a modified Gutzeit test, and nickel with a dimethylglyoxime spot test. [Pg.410]

The most common form of corrosion is uniform corrosion, in which the entire metal surface degrades at a near uniform rate (1 3). Often the surface is covered by the corrosion products. The msting of iron (qv) in a humid atmosphere or the tarnishing of copper (qv) or silver alloys in sulfur-containing environments are examples (see also SiLVERAND SILVER ALLOYS). High temperature, or dry, oxidation, is also usually uniform in character. Uniform corrosion, the most visible form of corrosion, is the least insidious because the weight lost by metal dissolution can be monitored and predicted. [Pg.274]

Since the higher thermal conduc tivity material (copper or bronze) is a much better bearing material than the conventional steel backing, it is possible to reduce the babbitt thickness to. 010-030 inch. Embedded thermocouples and RTDs will signal distress in the bearing if properly positioned. Temperature-monitoring systems have been found to be more accurate than axial-position indicators, which tend to have linearity problems at high temperatures. [Pg.944]

Copper (II), Bismuth (III) and lead (II), ai e important elements in the environment and they have essential roles in different biologieal systems. Lead is widely distributed in nature and exhibits severe deleterious effeets on human [1]. Copper is an essential element for the normal metabolism of many living organisms. Bismuth has been used in medieines for the treatment of helieobaeter pylorie-indueed gastritis [2, 3]. Therefore traee analysis of these elements is important for monitoring their eoneentration in the environment. [Pg.95]

Six iron anodes are required for corrosion protection of each condenser, each weighing 13 kg. Every outflow chamber contains 14 titanium rod anodes, with a platinum coating 5 /tm thick and weighing 0.73 g. The mass loss rate for the anodes is 10 kg A a for Fe (see Table 7-1) and 10 mg A a for Pt (see Table 7-3). A protection current density of 0.1 A m is assumed for the coated condenser surfaces and 1 A m for the copper alloy tubes. This corresponds to a protection current of 27 A. An automatic potential-control transformer-rectifier with a capacity of 125 A/10 V is installed for each main condenser. Potential control and monitoring are provided by fixed zinc reference electrodes. Figure 21-2 shows the anode arrangement in the inlet chamber [9]. [Pg.469]

Because silver, gold and copper electrodes are easily activated for SERS by roughening by use of reduction-oxidation cycles, SERS has been widely applied in electrochemistry to monitor the adsorption, orientation, and reactions of molecules at those electrodes in-situ. Special cells for SERS spectroelectrochemistry have been manufactured from chemically resistant materials and with a working electrode accessible to the laser radiation. The versatility of such a cell has been demonstrated in electrochemical reactions of corrosive, moisture-sensitive materials such as oxyhalide electrolytes [4.299]. [Pg.262]

White phosphorus. This element burns in air and can produce severe thermal and chemical burns. It may reignite on drying. After washing, rapid but brief treatment with copper sulphate (to avoid systemic absorption and copper poisoning) is used to convert the phosphorus to copper phosphide which is then removed Hydrogen fluoride. This can form painful but delayed necrosis. Treat with calcium gluconate locally and monitoring of serum calcium levels, with administration of calcium where necessary... [Pg.136]

Various types of reference electrodes have been considered in Section 20.3, and the potentials of these electrodes and their variation with the activity of the electrolyte are listed in Table 21.7, Chapter 21. It is appropriate, however to point out here that the saturated calomel electrode (S.C.E.), the silver-silver chloride electrode and the copper-copper sulphate electrode are the most widely used in corrosion testing and monitoring. [Pg.1010]

Industrial production media must also contain sources of potassium, phosphorous and magnesium. Trace elements may also have to be added. The water used for medium preparation will be from the public water supply or other readily available source. The quality of the water is carefully monitored because the presence of certain metal salts, for example, calcium, copper and iron, can have adverse effects on both the growth of the oiganism and the rheological properties of the exopolysaccharides. [Pg.204]

Certain internal chemical treatments employed also need strict control to avoid risks of adverse chemical reaction and resultant corrosion. In particular, nitrogen-containing chemicals such as hydrazine and amines require effective monitoring to limit the concentration of ammonia release into steam because the presence of ammonia may, under certain conditions, cause stress corrosion cracking of copper and brasses. [Pg.170]

The limited anodic potential range of mercury electrodes has precluded their utility for monitoring oxidizable compounds. Accordingly, solid electrodes with extended anodic potential windows have attracted considerable analytical interest. Of the many different solid materials that can be used as working electrodes, the most often used are carbon, platinum, and gold. Silver, nickel, and copper can also be used for specific applications. A monograph by Adams (17) is highly recommended for a detailed description of solid-electrode electrochemistry. [Pg.110]

The copper atom-acetylene matrix-reaction, monitored originally by esr spectroscopy (60) has now been investigated by IR/UV-visible spectroscopy (144), and there is general agreement on the identification of two mononuclear species, CuCCaHali.. The esr/IR/UV-visible... [Pg.154]

The organization for Economic Co-operation and Development publishes a compendium on environmental data including river monitoring, also on a biannual basis. The most recent edition includes 5 year incremental data from 1970 through 1985 for chromium, copper, lead, cadmium, ammonia, nitrate, phosphorous, dissolved oxygen and biochemical oxygen demand 28),... [Pg.244]

Mass Balance Estimates. Based on National Pollutant Discharge Elimination System monitoring reports, the total daily discharge of trace elements into the main stem Willamette River is of the order of 100 pounds per day. Seventy-five percent of the total is zinc with the bulk of the remainder due to chromium and copper. Table 6 identifies industrial and natural sources of trace elements into the Willamette basin. The table indicates that an average of 97 percent of all trace element loading to the basin is natural in origin. The natural component is due to weathering of soil and rocks in the basin and this... [Pg.276]

Recently Shihabi and Bishop (93) described a refinement in the preparation of a stable substrate and demonstrated the feasibility monitoring the reaction kinetically. This procedure has been evaluated by Lifton et. al. (9 ), who found that this method correlated well (r 0.914) with the copper soap-lipase method of Dirstine. They concluded that the method was rapid (less than 5 min. per sample), accurate, precise and linear over a clinically useful range. Its simplicity allows its application as an emergency procedure. Attempts to use this assay for urine lipase activity were unsuccessful. [Pg.214]


See other pages where Copper monitoring is mentioned: [Pg.158]    [Pg.473]    [Pg.158]    [Pg.473]    [Pg.1686]    [Pg.3]    [Pg.331]    [Pg.379]    [Pg.12]    [Pg.394]    [Pg.395]    [Pg.554]    [Pg.385]    [Pg.410]    [Pg.71]    [Pg.280]    [Pg.42]    [Pg.43]    [Pg.88]    [Pg.126]    [Pg.403]    [Pg.27]    [Pg.569]    [Pg.767]    [Pg.122]    [Pg.26]   
See also in sourсe #XX -- [ Pg.100 ]




SEARCH



Flux monitor, copper

Spectroscopic Monitoring and Characterization of Copper Centers

© 2024 chempedia.info