Commercial energy efficiency and the environment

The production and use of energy create serious, extensive environmental affects at every level, in every country, argue the authors. That impact may be more serious in developing than in developed countries as developing countries depend more on natural resources and lack the economic strength to withstand environmental consequences. At the same time, a reliable energy supply is vital to economic growth and development. Energy consumption and economic growth have been somewhat delinked at high income levels, but increased energy consumption (especially of electricity) is inevitable with higher GDP. Greater energy efficiency in developing countries and Eastern Europe is a high-priority way to mitigate the harm to the environment of growing energy consumption, say the authors. They outline four advantages of greater energy efficiency. It requires measures that are in the economic self-interest of those regions. Political obstacles make these measures difficult, but there are well-established techniques for addressing concerns about low-income consumers (such as direct income support or life-line rates). It will help conserve the world supply of nonrenewable (especially fossil) fuels. It will encourage appropriate fuel switching. It addresses every level of concern, up to the global effects of global warming. Any strategy to make energy use and production more efficient must rely more extensively than before on markets that are allowed to function with less government interference. The crucial components of such a straetegy (also crucial to economic development generally) are: more domestic and external competition; the gradual elimination of energy pricing distortions; the reduction of macroeconomic and sectoral distortions (for example, in foreign exchange and credit markets); the reform of energy supply enterprises - reducing state interference, providing more financial autonomy and a greater role for the private sector; consumer incentives to select more efficient lights, space heating, and so on. The authors are not convinced of the need for nonmarket approaches beyond those geared to correct externalities, provide essential information, support basic research and development, and possibly promote pilot projects. They also conclude that a government is far more likely to take action to reduce an environmental externality if it captures benefits within its own national boundaries that exceed the cost of the action. Reducing the large difference between energy prices and economic costs in developing countries and Eastern Europe is a more immediate issue than carbon taxes. The developed countries, say the authors, have an indispensable role to play in improving energy efficiency in the developing countries and Eastern Europe. They can encourage the flow of efficient technology, they can increase conventional aid, and they must accept a greater share of the burden of protecting the global commonalities.Energy and Environment,Environmental Economics&Policies,Energy Demand,Transport and Environment,Power&Energy Conversion

The Parenthood “Happiness Penalty”: The Effects of Social Policies in 22 Countries

A large body of research has established that parents are less happy than nonparents. But is it always true that parents are less happy than nonparents? This research brief, by PRC faculty research associate Jennifer Glass and colleagues, shows that the “happiness penalty” is entirely explained by the presence or absence of social policies that allow parents to better combine paid work with family obligations.Population Research Cente

Crystal structure, thermodynamics, magnetics and disorder properties of Be-Fe-Al intermetallics

The elastic and magnetic properties, thermodynamical stability, deviation from stoichiometry and order/disorder transformations of phases that are relevant to Be alloys were investigated using density functional theory simulations coupled with phonon density of states calculations to capture temperature effects. A novel structure and composition were identified for the Be-Fe binary {\epsilon} phase. In absence of Al, FeBe_5 is predicted to form at equilibrium above ~ 1250 K, while the {\epsilon} phase is stable only below ~ 1650 K, and FeBe_2 is stable at all temperatures below melting. Small additions of Al are found to stabilise FeBe_5 over FeBe_2 and {\epsilon}, while at high Al content, AlFeBe_4 is predicted to form. Deviations from stoichiometric compositions are also considered and found to be important in the case of FeBe_5 and {\epsilon}. The propensity for disordered vs ordered structures is also important for AlFeBe_4 (which exhibits complete Al-Fe disordered at all temperatures) and FeBe_5 (which exhibits an order-disorder transition at ~ 950 K).Comment: 14 pages, 10 figures, accepted for publication in J. Alloy Compd. on 14 March 201

Molecular dynamics study of oxygen diffusion in Pr₂NiO_4+δ

Oxygen transport in tetragonal Pr2NiO4+δ has been investigated using molecular dynamics simulations in conjunction with a set of Born model potentials. Oxygen diffusion in Pr2NiO4+δ is highly anisotropic, occurring almost entirely via an interstitialcy mechanism in the a-b plane. The calculated oxygen diffusivity has a weak dependence upon the concentration of oxygen interstitials, in agreement with experimental observations. In the temperature range 800-1500 K, the activation energy for migration varied between 0.49 and 0.64 eV depending upon the degree of hyperstoichiometry. The present results are compared to previous work on oxygen self-diffusion in related K2NiF4 structure materials

Anisotropic oxygen diffusion in tetragonal La₂NiO_4+δ: molecular dynamics calculations

Molecular dynamics simulations, used in conjunction with a set of Born model potentials, have been employed to study oxygen transport in tetragonal La2NiO4+δ. We predict an interstitialcy mechanism with an activation energy of migration of 0.51 eV in the temperature range 800-1100 K. The simulations are consistent with the most recent experiments. The prevalence of oxygen diffusion in the a-b plane accounts for the anisotropy observed in measurements of diffusivity in tetragonal La2NiO4+δ

Tensor distributions on signature-changing space-times

Irregularities in the metric tensor of a signature-changing space-time suggest that field equations on such space-times might be regarded as distributional. We review the formalism of tensor distributions on differentiable manifolds, and examine to what extent rigorous meaning can be given to field equations in the presence of signature-change, in particular those involving covariant derivatives. We find that, for both continuous and discontinuous signature-change, covariant differentiation can be defined on a class of tensor distributions wide enough to be physically interesting.Comment: 9 pages, LaTeX 2.0

Twisted Electromagnetic Modes and Sagnac Ring-Lasers

A new approximation scheme, designed to solve the covariant Maxwell equations inside a rotating hollow slender conducting cavity (modelling a ring-laser), is constructed. It is shown that for well-defined conditions there exist TE and TM modes with respect to the longitudinal axis of the cavity. A twisted mode spectrum is found to depend on the integrated Frenet torsion of the cavity and this in turn may affect the Sagnac beat frequency induced by a non-zero rotation of the cavity. The analysis is motivated by attempts to use ring-lasers to measure terrestrial gravito-magnetism or the Lense-Thirring effect produced by the rotation of the Earth.Comment: LaTeX 31 pages, 3 Figure

"Fiscal Equalization in Japan: Assessment and Recommendations"

Intergovernmental fiscal relations in Japan have been strained in recent years. This paper seeks to assess the Japanese equalization transfer in the light of the theory of fiscal federalism. This paper argues that the case for equalization lies in offsetting net fiscal benefit (NFB) differentials across jurisdictions. It has been shown that the case for equalization and its design depend on the type of public good being provided as well as the mode of finance. Moreover, where equalization is called for, its form and level can be very different depending on whether the relevant policy goal is that of fiscal equity or fiscal efficiency. Studying the institutional context, we arrive at the conclusion that the system of equalization transfers in Japan is consistent with the application of those principles.

Interstitialcy diffusion of oxygen in tetragonal La₂CoO_4+δ

We report on the mechanism and energy barrier for oxygen diffusion in tetragonal La2CoO4+δ. The first principles-based calculations in the Density Functional Theory (DFT) formalism were performed to precisely describe the dominant migration paths for the interstitial oxygen atom in La2CoO4+δ. Atomistic simulations using molecular dynamics (MD) were performed to quantify the temperature dependent collective diffusivity, and to enable a comparison of the diffusion barriers found from the force field-based simulations to those obtained from the first principles-based calculations. Both techniques consistently predict that oxygen migrates dominantly via an interstitialcy mechanism. The single interstitialcy migration path involves the removal of an apical lattice oxygen atom out from the LaO-plane and placing it into the nearest available interstitial site, whilst the original interstitial replaces the displaced apical oxygen on the LaO-plane. The facile migration of the interstitial oxygen in this path is enabled by the cooperative titling-untilting of the CoO6 octahedron. DFT calculations indicate that this process has an activation energy significantly lower than that of the direct interstitial site exchange mechanism. For 800-1000 K, the MD diffusivities are consistent with the available experimental data within one order of magnitude. The DFT- and the MD-predictions suggest that the diffusion barrier for the interstitialcy mechanism is within 0.31-0.80 eV. The identified migration path, activation energies and diffusivities, and the associated uncertainties are discussed in the context of the previous experimental and theoretical results from the related Ruddlesden-Popper structures

Exact partial information decompositions for Gaussian systems based on dependency constraints

The Partial Information Decomposition (PID) [arXiv:1004.2515] provides a theoretical framework to characterize and quantify the structure of multivariate information sharing. A new method (Idep) has recently been proposed for computing a two-predictor PID over discrete spaces. [arXiv:1709.06653] A lattice of maximum entropy probability models is constructed based on marginal dependency constraints, and the unique information that a particular predictor has about the target is defined as the minimum increase in joint predictor-target mutual information when that particular predictor-target marginal dependency is constrained. Here, we apply the Idep approach to Gaussian systems, for which the marginally constrained maximum entropy models are Gaussian graphical models. Closed form solutions for the Idep PID are derived for both univariate and multivariate Gaussian systems. Numerical and graphical illustrations are provided, together with practical and theoretical comparisons of the Idep PID with the minimum mutual information PID (Immi). [arXiv:1411.2832] In particular, it is proved that the Immi method generally produces larger estimates of redundancy and synergy than does the Idep method. In discussion of the practical examples, the PIDs are complemented by the use of deviance tests for the comparison of Gaussian graphical models.Comment: 39 pages, 9 figures, 9 table