Paper-layering process 692 Subject

Before fluorination, the dielectric constant ofpoly(bisbenzocyclobutene) was 2.8, and this value was reduced to 2.1 after plasma treatment. No data were reported in the paper on characterization of structure or properties, except for the dielectric constant of the modified poly(bisbenzocyclobutene). The authors did report that the thermal stability offluorinatedpoly(vinylidenefluoride) was inferior to the original poly(vinylidenefluoride) when treated in a similar way. One of the probable reasons for the low thermal stability is that the NF3 plasma degraded the polymer. According to their results, the thickness of fluorinated poly(bisbenzo-cyclobutene) was reduced by 30%. The same phenomenon was observed for other hydrocarbon polymers subjected to the NF3 plasma process. A remaining question is whether plasma treatment can modify more than a thin surface layer of the cured polymer Additionally, one of the side products generated was hydrogen fluoride, which is a serious drawback to this approach. 

The macro-scale investigations showed that pretreatment of an iron surface with steam at 700°C itduces a dramatic increase in the catalytic activity for carbon deposition from hydrocarbons. Spectroscopic analysis (Auger and Mossbauer) combined with weight increase measurements prove that treatment of iron with steam at 700°C results in the conversion of the surface of the iron to FeO. At 800°C, this process is not just limited to the uppermost surface layers but penetrates to an appreciable depth of the material after a three hour treatment. Indeed Mossbauer spectroscopy data shows that nearly all of a 0.013 cm Fe foil is transformed to FeO in this time at 800°C. It should be mentioned that the reaction of steam with iron to produce FeO may be possible at temperatures above 570°C (3). The nonstoichiometric nature of FeO has been the subject of "a considerable number of papers. It is known, however, that the defects present in this material are vacant cation sites and trapped positive holes (26). 

Any surface subjected to water-containing micro-organisms will sooner or later become coated with a layer of bacteria. Deposits that contain a high amount of micro-organisms are referred to as (biological) slime or biofilm, because of their slimy or gel-like character. Slime formation is most obvious in areas where the water flow is insufficient to dislodge the accumulation. The process of biofilm formation is known as biofouling. Biofihns occur in most water systems, and the pulp and paper industry is just one of many industries where this occurs. 

A large number of papers dealing with laser-induced temperature jumps were addressed to heterogeneous rate constants in electrochemical kinetics [78-83]. Heterogeneous rate processes have been studied [78], as well as double-layer formation at glassy carbon electrodes [79]. Superfast electrode reactions [80] and short-lived intermediates at electrode surfaces [81, 82] were the subject of investigations. Anodic silver oxidation m the presence of different anions has been studied [83, 84]. 

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