ACTIS process

The ACTIS process described above is a typical example of low-pressure plasma polymerization or LCVD, which is an ultimate green process with no effluent in the practical sense. Microwave plasma is used for plasma polymerization of acetylene. ACTIS process, as an example of LCVD, has an ideal combination of unique advantages in (1) very high reaction yield (monomer to coating), (2) no effluent from the process, (3) no reactor wall contamination because the reactor wall is the substrate surface, and (4) very short reaction time. However, whether such an ideal LCVD process is an industrially viable practice is a totally different issue. 

Figure 20.29 (A) ACTIS process time = 2.5 s. (B) ACTIS Lite process time = 1.2 s. (Reproduced with permission from Sidei).

The important influence of the LFAE is also nicely demonstrated on the labilities of V2+ andV3+.The smaller LFAE of t g [V(H20)6]3+ makes it about six times more labile than t2g [V(H20)6]2+ despite the smaller charge of the 2+ complex (Fig. 5). Both exchange processes are a-acti-vated with negative volumes of activation of —8.9 (V3+) (113) and —4.1 cm3 mol-1 (V2+) (68). 

Gaudy, A.F. Jr. and E.T. Gaudy (1971), Biological concepts for design and operation of the acti vated sludge process, US Environmental Protection Agency, Water Pollution Research Series, Rep. no. 17090, FQJ, 09/71, USEPA, Washington, DC. 

The chemical aspect of the coenzymatic action of a-lipoic acid is to mediate the transfer of electrons and acti-vated acyl groups resulting from the decarboxylation and oxidation of a-keto acids within the complexes. In this process, lipoic acid is itself transiently reduced to dihydrolipoic acid (see fig. 10.12), and this reduced form is the acceptor of the activated acyl groups. Its dual role of electron and acyl-group acceptor enables lipoic acid to couple the two processes. 

Compound 23 is the active alkylating agent. The a-carbon atom is acti ated toward nucleophilic attack, permitting it to alkylate the nitrogen of the deprotonated succinimide 5 to give TV-butenylimide 7. This releases triphenylphosphine oxide (Ph3P=0). Thus, in the overall process DFAD is reduced to hydrazine derivative 22, whereas triphenylphosphine is oxidized to triphenylphosphine oxide. 

As some rewiews 14) deal with this challenging and as it happens not yet completely settled problem, we shall only briefly resume some facts. In fluoroacetylenes, the nucleophile attacks at C-l tends to localize the negative charge at C-2, away from fluorine. This process is favourable both by the kinetic (low energy of acti vation due to... 

Qm at the equilibrium distance rm. Molecular adsorption is usually a non-acti-vated process. The solid curves represent adsorption of the atoms following dissociation of the molecule in the gas phase, the heat of adsorption is Qd at the equilibrium distance r < rm corresponding to the short-range chemical interaction. 

Nowadays, methods are known for the preparation of porous polymeric supports comprising particulate material from an appropriate mixture of starting components. Such a material prepared by a casting process is limited in its three dimensional size by the housing it is cast into (Zip Tip, Milhpore, Eigure 3.11a and 3.11b) or is in the form of a sheet (Empore Acti-Mod, EMC Bioproducts Biorex, Bio-Rad) [16,17]. 

The process of digestion and the activity of carbonic anhydrase are major ev cryday concerns in the medical profession. A clearer understanding of the concepts of protein digestion and carbonic anhydrase acti ity is provid by simplified descriptions of the relevant biochemical mechanisms. Protein digestion involves the addition of water to a peptide bond. Carbonic anhydrase activity involves the addition of water to COj. A related process, the phosphorolysis of glycogen, is also described. 

In the Talspeak process, the separation of trivalent actinides and lanthanides is accomplished by coextracting the two groups of elements into di(2-ethyl hexyl)phosphoric acid (HDEHP) from a carboxylic acid solution and then partitioning the acti-... 

The acti vity of enzymes often must be regulated so that they function at the proper time and place. This regulation is essential for coordination vast array of biochemical processes taking place at any instant in an organism. Enzymatic activity is regulated in five principal ways ... 

Another motif recurs in this activation reaction. The enzyme-bound acyladenylate intermediate is not unique to the synthesis of acyl CuA. Acyl adenylates are frequently formed when carboxyl groups are acti vated in biochemical reactions. Amino acids are activated for protein synthesis by a similar mechanism (p. 862), although the enzymes that catalyze this process are not homologous to acyl CoA synthetase. Thus, activation by adenylation recurs in part because of convergent evolution. 

Despite considerable research, the mechanisms of protein turnover are still unclear. However, several aspects of this process are now known. Proteins are degraded by proteolytic enzymes found throughout the cell. These include the cytoplasmic Ca2+-acti-vated calpains and the lysosomal cathepsins. In addition, ubiquina-tion is now believed to have a major role in protein turnover. In ubiquination, illustrated in Figure 15A, several molecules of a small 76-residue eukaryotic protein called ubiquitin are covalently attached to some proteins destined for degradation. Once a pro-... 

The spikes are of two types. One type (haemagglutinin) has a vital role in the first stages of infection, the penetration of host cells. The second type of spike is made of an enzyme called sialidase, whose role is to help newly formed viruses escape from the host cell so that they can move on to infect other cells. As part of this process, sialidase cleaves off sialic acid from oligosaccharides (short chains of carbohydrate units). These sialidase spikes have clefts that contain an acti ve site, into which bound sialic acid (Structure 3.1) fits during the cleavage process. This active site... 

TREATABILITY/REIMOVABILITY (Process, Removable Range (%), Avg. Achiev able Cone. (pg/L)) Aerated lagoons, 0, negative removal Activated sludge, 47->97, 0.4 Acti vated sludge (based on synthetic wastewater), 56, 2200 Powdered activated carbon adsorptiot (based on synthetic wastewater), 90, 79,000 can be physically removed by washout by rainfal and dry deposition... 

Sidel, a French company, has developed the Actis plasma process that coats the inside of PET bottles with a 0.15 micron thick layer of amorphous carbon to improve oxygen and carbon dioxide barrier. Actis stands for Amorphous Carbon Treatment on Internal Surface. The carbon is deposited from acetylene gas, using a microwave-assisted process to excite the gas into plasma. The bottles are clear, and the process is reported to increase the carbon dioxide barrier of beer bottles by up to seven times, while not interfering with recycling. Actis has been approved by FDA, and is reported to cost 20 to 25 percent less than multilayer PET bottles with comparable barrier properties [10], Sidel has also developed Actis Lite a lower level of treatment for carbonated soft drink bottles, sparkling waters, juices, teas, and sauces, which do not require as good a barrier as beers and ciders. 

Observations from operating BWR plants suggest that on the surfaces wetted by high-temperature reactor water, one has to expect a deposition mechanism which is similar to that on the surfaces of a PWR primary circuit. The activation products released from the activated in-core materials, as well as from the fuel rod deposits, as dissolved ions are incorporated into the oxide layers on the austenitic out-of-core surfaces directly from the reactor water. The activated crud which is resuspended from the fuel rod surfaces is also partly deposited on the out-of-core surfaces here, colloid chemistry processes may participate in the deposition process. These corrosion products often show a higher cobalt content than the non-acti-vated corrosion products that are brought in with the feedwater. During the residence time of the particulate corrosion products on the out-of-core surfaces, this excess cobalt content is reduced therefore, the activated crud can be considered as an additional source of ionic cobalt (Alder et al., 1992). 

The results obtained fi-can analytical equipment measuring the compositicHi of a reactor output are normally reported in mol fractions. In most cases the mol fiactions of components at the outlet are autcxnatically re-normalized so that their sum is one. This is correct as fiu- as mol fi-actions are concerned, but the atomic balances of the output may well be off due to both analytical errex and the process of re-nonnalization iqq>Iied to the measured mole fi acti< is. Hiis is an issue that needs to be addressed in eadi instance, regardless of reactor emfiguration or the mode of reactor < )CTation. At the same time this is a particularly well conditioned problon to address in the case of the voluminous data fi om a TSR expohneit. 

The process is called ACTIS (Amorphous Carbon Treatment on Internal Surface). It consists of coating the internal surface of a standard single-layer PET bottle with a layer of highly hydrogenated amorphous carbon, obtained from food gas in its plasma state. The coating creates a thin (about 0.1 pm thick) barrier inside the bottle. The food safety quality has been approved by the Dutch standards authority (which is also accredited to the European Union), and the coated bottle is 100% recyclable. 

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