Deca potential

These results produce an ordering of the one-electron reduction potentials as shown in Figure 14.9. This order is consistent with results on the reactions of oxygen and porphyrins with carotenoids (McVie at al. 1979, Conn et al. 1992), for example, p-CAR - reacts much more efficiently with oxygen than LYC - and DECA -. Comparative studies have been made in benzene due to the decreased solubility of XANs in hexane and Table 14.8 gives the corresponding bimolecular rate constants for electron transfer. Overall, the one-electron reduction potentials increase in the order ZEA < P-CAR LUT < LYC < APO - CAN < ASTA. 

Organic semiconductors are becoming increasingly important in the fabrication of electronic devices. For electron transport, metal complex pigments, such as hexa-deca-fluoro copper phthalocyanine (76), are showing potential.79... 

A variety of other highly-strained electron-rich donors also form colored complexes (similar to homobenzvalene) with various electron acceptors, which readily undergo thermal cycloadditions (with concomitant bleaching of the color).209 For example, Tsuji et al.210 reported that dispiro[2.2.2.2]deca-4,9-diene (DDD), with an unusually low ionization potential of 7.5 eV,211 readily forms a colored charge-transfer complex with tetracyanoquinodimethane (TCNQ). The [DDD, TCNQ] charge-transfer complex undergoes a thermal cycloaddition to [3,3]paracyclophane in excellent yield, i.e.,... 

Finally, PBDEs—mainly three commercial mixtures known as Penta-BDE, Octa-BDE, and Deca-BDE—are still widely used as flame retardants in products such as polymers, resins, electronic devices, building materials, textiles, and the polyurethane foam padding used in furniture and carpets. The intensive production and use of these compounds has made them ubiquitous in the environment and in biota.125,126 EPA is working with industry, governments, and environmental and public health groups to research and better understand the potential health risks posed by these substances.127 The European Commission is also aware of these risks to the environment and public health and has established EQS in the low ppt level. Thus, for Penta-BDE, the annual average (AA) EQS is 0.0005 pg L 1 for inland surface waters and 0.0002 pg L 1 for other surface waters. There... 

Two other bacteriophage systems have also been investigated as potential phage-display vectors, namely bacteriophage T4 [131], where a C-terminal extension on fibritin encoded by gene wac (whisker s antigen control) could be displayed, and P4 [132], where a deca-peptide was successfully inserted and presented near the N-terminus of the capsid decoration component, Psu. Their relative usefulness cannot yet be evaluated. 

The Administrative Measure on the Control of Pollution Caused by Electronic Information Products (China-RoHS) entered into force in March 2007.85 The legislation is applicable to import, manufacture, and sale of products in China. Products for export are specifically excluded. Many product types that are not within the scope of the EU RoHS are within the scope of the China RoHS and vice versa. In addition, the initial disclosure, declaration, and exemption requirements for a RoHS certificate in China are different from the EU RoHS. The same six hazardous substances are regulated (lead, cadmium, chromium(VI), mercury, PBBs, and PBDEs, with the exception of deca-BDE). The China RoHS is likely to be upgraded to national regulation and to be amended in the future to potentially cover more products. More detailed materials testing is required in the China RoHS and is accepted only if performed by certified Chinese laboratories. A table in the product documentation must identify which hazardous substances are contained and which components are present. 

Abstract In this chapter relatively recent European Commission risk assessment reports for three potential PBT/vPvB chemicals are used as examples to illustrate scientific uncertainty in the risk assessment process, and how science and policy interact when such uncertainty is handled. The studied risk assessment reports are for pentabromodiphenylether (Penta), octabromodiphenylether (Octa), and decabromodiphenylether (Deca) and the analyses focus on the scientific basis for assessing the risk of potential PBT and vPvB properties as described in these documents. The purpose of this effort is to contribute to a discussion aiming at clarifying the nature of science-policy interactions, and improving the transparency of the risk assessment process. 

The European Commission risk assessment reports for the diphenylethers Penta (European Commission 2001), Octa (European Commission 2003b), and Deca (European Commission 2002 and 2004) were used to identify examples of scientific uncertainties in the risk assessment process for potential PBT/vPvB substances. A systematic search for indicators of scientific uncertainty in these documents was performed, including how these uncertainties are described and handled in the risk characterization and in the conclusions section, and taking into consideration the use of and weight given to non-standard data in the final conclusions. 

Regarding human health risks the Deca risk assessors note that scientific information on bioconcentration in human adipose tissues and subsequent elimination via for example breast milk is insufficient, but that other brominated diphenyl ethers (i.e. Hexa, Penta and Tetra) are excreted with breast milk. Based on the low rate of oral absorption in rats and the low bioaccumulation potential, the Deca risk assessors state that they might anticipate a rather low excretion of this compound in the breast milk. ... 

F. Belot, C. Guerreiro, F. Baleux, and L. A. Mulard, Synthesis of two linear PADRE conjugates bearing a deca- or pentadecasaccharide B epitope as potential synthetic vaccines against Shigella flexneri serotype 2a infection, Eur. J. Chem., 11 (2005) 1625-1635. 

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