Statistical energy analysis computer program, user's guide

A high frequency random vibration analysis, (statistical energy analysis (SEA) method) is examined. The SEA method accomplishes high frequency prediction of arbitrary structural configurations. A general SEA computer program is described. A summary of SEA theory, example problems of SEA program application, and complete program listing are presented

The Impact of Feedstock Supply and Petroleum Price Variability on Domestic Biofuel and Feedstock Markets – The Case of the United States

The promotion of biofuel use in preference to traditional petroleum-based transportation fuel has linked agricultural commodity markets and energy markets more closely together. Biofuel policies can involve multiple policy instruments, but studies examining their effects on biofuel feedstock and energy markets are scarce. In addition, the impact of alternative policy approaches in the context of variability in petroleum prices and the supply of biofuel feedstock has received limited attention. Focusing on the current situation in the United States, in which prohibitively high duties prevent imports of ethanol, this paper examines how variability in the price of petroleum and corn supply affects domestic market variability under three types of domestic policies, inclusive of their combinations, for promoting the use of ethanol: 1) the provision of a fixed subsidy (tax credit) for blending ethanol with gasoline; 2) the use of a blending mandate; and 3) the use of a consumption mandate. Varying relative variability in petroleum price and corn supply, we analyze numerically the implications of changes in domestic biofuel policy for variability (measured by the coefficient of variation) in ethanol use and corn prices. We also provide some brief insights into the design of market stabilization policies. Results obtained from Monte Carlo simulations show that in the absence of mandates the quantity of ethanol used under a subsidy policy is highly susceptible to fluctuations in oil prices and corn supply, providing that there are no constraints to adjustment in ethanol demand. The impact of oil price fluctuations on the price of corn is large, but corn supply fluctuations have no or a small impact on the equilibrium corn price, depending on the flexibility of the use of corn in ethanol refining. This is because variations in ethanol volume absorb shocks caused by corn supply fluctuations. Consequently, high fluctuations in the price of petroleum are expected to result in high variability in the corn price in the absence of mandates. With a mandate (with or without a subsidy), as the likelihood that the mandate becomes binding increases, variability in ethanol use declines, the impact of variations in petroleum price on corn prices is reduced, and the impact of variations in corn supply on prices is accentuated. Therefore, if the mandate is likely to be binding, high fluctuations in corn supply are expected to result in high variability in the corn price. If the likelihood that ethanol use exceeds the mandated level is high, the effects are similar to those in the absence of a mandate. The effects of changes in biofuel policy, such as a reduction in the level of tax credit under a mandate and an increase in its level, on the price of corn depend on the relative magnitudes of world oil price and domestic corn supply fluctuations.biofuels, subsidies, mandates, variability, Agricultural and Food Policy, International Relations/Trade, Resource /Energy Economics and Policy,

The Implications of Alternative U.S. Domestic and Trade Policies for Biofuels

The U.S. Renewable Fuel Standard program (RFS), which involves mandates for various biofuels, is complex and has been often misinterpreted or oversimplified in previous studies. In this paper we analyze the implications of the RFS for the U.S. domestic and international ethanol markets. We demonstrate the vital role of the advanced biofuel mandate within the RFS. Impacts of changes in tariffs on imported fuel ethanol and subsidies for U.S. domestic ethanol production are examined. One of our important findings is that the RFS could result in serious misallocation of resources in both a national and international context. There is a possibility that the United States could be required to import sugarcane-based ethanol to meet the advanced biofuel mandate, simultaneously exporting corn-based ethanol, while satisfying the national overall mandate. Since the provision of subsidies for domestic ethanol production can stimulate exports of corn-based ethanol, they are equivalent to export subsidies in this situation. The removal of tariffs can reduce the burden imposed on consumers in the United States from the operation of the RFS. Our analysis shows that it is extremely important to understand the potential impact of the RFS on agricultural and energy markets.Ethanol, trade liberalization, Renewable Fuel Standard, mandate, subsidies, Industrial Organization, F13, Q18, Q42, Q48,

International Variability in Biofuel Trade: An Assessment of U.S. Policies

Although the United States has typically been in a position to import ethanol, corn-based ethanol exports are surging as the domestic market becomes saturated and world prices rise due to high prices for sugar, the competing global feedstock. The U.S. is now the world’s leading ethanol producer but domestic demand is constrained because of technical limitations in the current vehicle fleet. Higher ethanol blends have been approved for use (15% rather than 10%) but a limited number of vehicles that can use such higher blends. Infrastructure constraints also affect the potential supply of higher ethanol blends. As a result of these factors, U.S. biofuel policies can have significant implications for the world ethanol market. Usage mandates under the Renewable Fuel Standard, blender tax credits, and the blend wall can interact to generate excess supplies of ethanol that are likely to be diverted to the world market. This paper examines how fluctuations in corn yield and gasoline prices affect the excess supply of U.S. corn-based ethanol in the presence of alternative assumptions about the maximum amount of ethanol that can be consumed domestically. Using stochastic simulations we also explore the impact of current policies on the mean and variance of export supply. The results highlight the complex interaction between technological constraints, economic incentives, and government policies in the U.S. biofuels sector, and point to the potentially destabilizing effect of such policies in international markets.Ethanol Exports, Biofuel Policies, Variability, International Relations/Trade, Resource /Energy Economics and Policy,

Kaluza-Klein dimensional reduction and Gauss-Codazzi-Ricci equations

In this paper we imitate the traditional method which is used customarily in the General Relativity and some mathematical literatures to derive the Gauss-Codazzi-Ricci equations for dimensional reduction. It would be more distinct concerning geometric meaning than the vielbein method. Especially, if the lower dimensional metric is independent of reduced dimensions the counterpart of the symmetric extrinsic curvature is proportional to the antisymmetric Kaluza-Klein gauge field strength. For isometry group of internal space, the SO(n) symmetry and SU(n) symmetry are discussed. And the Kaluza-Klein instanton is also enquired.Comment: 15 page

The relation between the two-point and the three-point correlation functions in the non-linear gravitational clustering regime

The connection between the two-point and the three-point correlation functions in the non-linear gravitational clustering regime is studied. Under a scaling hypothesis, we find that the three-point correlation function, $\zeta$, obeys the scaling law $\zeta\propto \xi^{\frac{3m+4w-2\epsilon}{2m+2w}}$ in the nonlinear regime, where $\xi$, $m$, $w$, and $\epsilon$ are the two-point correlation function, the power index of the power spectrum in the nonlinear regime, the number of spatial dimensions, and the power index of the phase correlations, respectively. The new formula reveals the origin of the power index of the three-point correlation function. We also obtain the theoretical condition for which the ``hierarchical form'' $\zeta\propto\xi^2$ is reproduced.Comment: 16 pages, 4 figures. Accepted for publication in APJ. Some sentences and figures are revise

Conformal classes of asymptotically flat, static vacuum data

We show that time-reflection symmetric, asymptotically flat, static vacuum data which admit a non-trivial conformal rescaling which leads again to such data must be axi-symmetric and admit a conformal Killing field. Moreover, it is shown that there exists a 3-parameter family of such data.Comment: 23 page

New and interesting records of Brazilian bryophytes

This paper presents data on morphology, ecology and distribution of 16 species of bryophytes collected in Pernambuco, Brazil, that are interesting floristic records. Notothylasorbicularis (Schwein.) Sull. is new to Brazil, 11 species are new to the Northeast region of Brazil and 4 species are new to Pernambuco.Dados morfológicos, ecológicos e de distribuição geográfica são apresentados para 16 espécies de briófitas coletadas no Estado de Pernambuco, Brasil. Notothylas orbicularis (Schwein.) Sull. é registrada pela primeira vez para o Brasil, 11 espécies são novas para a região Nordeste e 4 para o Estado de Pernambuco