Third Party Access pricing to the network, secondary capacity market and economic optimum : the case of natural gas

The gas deregulation process implies crucial choices concerning access to transportation networks. These choices deal with the nature, the structure and the level of access fees. This paper proposes an evaluation of different systems implemented both in Europe and North America, in relation to normative pricing references. The rules according to which shippers can buy or sell capacity represent another kind of choice that Regulators have to make. This paper proposes a simple model which demonstrates that secondary market prices should not be subject to a cap and emphasizes the need of a 'use-it-or-lose-it' rule on this market.DEREGLEMENTATION; INVESTISSEMENT; OPTION REELLE; FINANCEMENT OPTIMAL; PRIX DE REVIENT; ELECTRICITE

Grackles

Numbering in the tens of millions of birds, grackle populations in North America can cause a variety of conflicts with people. Grackles eat agricultural crops and livestock feed, damage property, spread pathogens, and collide with aircraft. Their large roosts can be a nuisance in urban and suburban areas. A combination of dispersal techniques, exclusion, and lethal removal may help to reduce grackle damage. Grackles adapt easily to human-dominated environments, and exploit human food and other features of human landscapes. Thus, an integrated damage management approach to grackle damage focuses on reducing and eliminating the damage, rather than simply controlling grackle populations. Three species of grackles are present in North America: the common grackle, the boat-tailed grackle, and the great-tailed grackle. A fourth species, the greater Antillean grackle (Q. niger) is present in Puerto Rico. All are part of the Family Icteridae that includes blackbirds, orioles, cowbirds, meadowlarks, and bobolinks. The population status of all three grackle species is considered common to overabundant

Urban Sprawl and the Finances of State and Local Governments

Concern over the rate of spatial growth of urban areas has become a significant national political issue and a major development issue in many urban areas. An often cited statistic, typically presented as evidence of sprawl, is that between 1960 and 1990 the urban population in the United States increased by 50 percent while the amount of developed land more than doubled (Benefield et al., 1999).While much has been written about the causes and consequences of sprawl, little attention has been paid to the implications of sprawl for the finances of state and local government. There are at least two possible channels for sprawl to affect the finances of state and local governments. First, if the causes of sprawl include market failures or government policies, there may be a role for governmental corrective action. Second, sprawl may affect the costs of and revenue sources for the public provision of goods and services. This paper considers the potential effects that sprawl might have on the finances of state and local governments and the possible policies that might be adopted to address the causes and consequences of sprawl

Theory and Observation of Displacement Phenomena in Coadsorbed Films

Displacement refers to a surprising phenomenon observed in a number of adsorption systems. At low temperatures, some relatively inert gases, such as krypton (Kr) or methane ( CH4), are found to displace molecules from preadsorbed monolayer films of a more condensable species, such as carbon tetrachloride ( CCl4), from a graphite substrate. We present a simple thermodynamic model to explain displacement and make a prediction applicable to both first-order and continuous displacement processes. We also present measurements on CH4/CCl4 and Kr/CCl4 coadsorbed films from 77–112 K that verify our prediction and yield the CCl4 film spreading pressure