Effective Oxygen

Access of air and water will also affect the corrosion rate. Metal inserts in corrosive plastics are most actively attacked at the plastic/metal/air interfaces with certain metals, notably aluminium titaniumand stainless steel, crevice effects (oxygen shielding and entrapment of water) frequently accelerate attack. Acceleration of corrosion by bimetallic couples between carbon-fibre-reinforced plastics and metals presents a problem in the use of these composites. 

The carbonyl (COO ) group, which carries a full charge, will have the most pronounced effect. Oxygen atoms of hydroxyl groups carry a partial negative charge and, therefore, repel each other. 

In almost all industrial circumstances, a deaerator is a cost-effective oxygen-removing proposition that complements primary pretreatment equipment such as water softeners. 

NOTE The injection point of chelant should be into the boiler FW as far downsteam as possible from the deaerator and chemical oxygen scavenging point to permit sufficient time for effective oxygen removal to take place. 

Effective oxygen scavenging, down to less than 5 ppb is generally required, plus good pH control because the BW is unbuffered. Typically, the pH of the BD is slightly lower than that of the FW because some of the (alkaline) amine in the BW leaves with the steam. 

Ichinose, H. Wariishi, H., and Tanaka, H., Effective oxygen transfer reaction catalyzed by microperoxidase-11 during sulfur oxidation of dibenzothiophene. Enzyme and Microbial Technology, 2002. 30 pp. 334—339. 

The air gas-diffusion electrode developed in this laboratory [5] is a double-layer tablet (thickness ca.1.5 mm), which separates the electrolyte in the cell from the surrounding air. The electrode comprises two layers a porous, from highly hydrophobic, electrically conductive gas layer (from the side of the air) and a catalytic layer (from the side of the electrolyte). The gas layer consists of a carbon-based hydrophobic material produced from acetylene black and PTFE by a special technology [6], The high porosity of the gas layer ensures effective oxygen supply into the reaction zone of the electrode simultaneously the leakage of the electrolyte through the electrode... 

The hydrophobic gas layer of the air electrode [4] possesses high porosity (ca. 0,9 cm2/g), such that an effective oxygen supply through this layer is obtained. From the experimental porogrames measured by both mercury and 7 N KOH-porometiy the contact angle 0en of the hydrophobic material with water electrolytes is obtained (0eff =116° 118°). Because of... 

We have exploited this base catalysis of the oxygen exchange process to effect oxygen lability in the less electrophilic carbonyl sites of neutral metal carbonyl species. Because [MCOOH] intermediates are readily decarboxylated in the presence of excess hydroxide ion, in order to observe oxygen exchange processes in neutral metal carbonyl complexes it was convenient to carry out these reactions in a biphasic system employing phase transfer catalysis () (16, 17. 18). Under conditions (eq. 7) the... 

Inorganic reagents are generally used to selectively functionalize resist films after exposure to effect oxygen RIE resistance, and several examples have recently appeared in the literatures (78-80). 

Once the oxidative-addition reaction of dioxygen to metal d -ions has occurred, the essentially electrophihc dioxygen becomes a nucleophilic peroxide ligand. Since the oxidation of substrates is associated with electron transfer from the substrate to the oxidant, i.e. in this case the dioxygen adduct, effective oxygenations require a further activation to transform the nucleophihc peroxide into an electrophihc species prior to the oxygen transfer. 

The epoxidation of olefins catalyzed by iminium salts and amines (or ammonium salts) is emerging as a new technique for the functionalization of simple aUcenes. These catalysts have relatively simple structures and hence are easily produced at scale they offer potential as green oxidation catalysts. These organic salts are effective oxygen transfer reagents towards electron-rich unfunctionalized olefins. For the iminium salt systems oxone oxidizes an iminium salt to the oxaziridi-nium intermediate, which then transfers oxygen to the olefin and as oxone reacts readily with iminium ions to regenerate the oxaziridinium species catalyti-cally, efficient oxidation is possible. 

The oxidation of sulfides is the most straightforward method for the synthesis of sulfoxides and sulfones.During recent years, very useful procedures involving aqueous hydrogen peroxide (H2O2) as the terminal oxidant are noteworthy due to the effective oxygen-content, low cost, safety in storage and operation and... 

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