Competition between structural distortion and magnetic moment formation in fullerene C20_{20}

We investigated the effect of on-site Coulomb interactions on the structural and magnetic ground state of the fullerene C$_{20}$ based on density-functional-theory calculations within the local density approximation plus on-site Coulomb corrections (LDA+$U$). The total energies of the high symmetry ($I_{h}$) and distorted ($D_{3d}$) structures of C$_{20}$ were calculated for different spin configurations. The ground state configurations were found to depend on the forms of exchange-correlation potentials and the on-site Coulomb interaction parameter $U$, reflecting the subtle nature of the competition between Jahn-Teller distortion and magnetic instability in fullerene C$_{20}$. While the non-magnetic state of the distorted $D_{3d}$ structure is robust for small $U$, a magnetic ground state of the undistorted $I_{h}$ structure emerges for $U$ larger than 4 eV when the LDA exchange-correlation potential is employed.Comment: 4 figures, 1 tabl

Consumer Valuation of the Second Generation of Genetically Modified (GM) Foods with Benefits Disclosure

Employing contingent valuation method (CVM), the study explores whether or not consumers risk/benefit beliefs and knowledge about GM foods affect their behavior as measured by willingness to pay (WTP) a premium for GM beef with benefits. The results demonstrate that risk/benefit perceptions play a significant role to elicit WTP for GM beef with benefitsConsumer/Household Economics,

THE EFFECTS OF RISK PERCEPTIONS ON CONSUMER PREFERENCES FOR BIOTECH LABELING

Consumer/Household Economics,

A MULTINOMIAL LOGIT MODEL OF CONSUMER PERCEPTIONS FOR BIOTECH FOOD LABELING

A multinomial logit analysis is employed to analyze consumers' perceptions about purchasing biotech foods and their preferences for mandatory and voluntary labeling. Results showed that consumers who are sensitive to the possible side effects of biotech crops on wildlife and the environment are more likely to support a mandatory labeling policy. Results also indicated that respondents who believe biotech foods may have unforeseen health risks are more likely to favor mandatory labeling. Furthermore, the study found that respondents who are willing to buy a meat product produced using biotechnology are more likely to favor a voluntary labeling policy.Institutional and Behavioral Economics,