Remanufacturing

Remanufacturing is a form of recycling where used durable goods are refurbished to a condition comparable to new products. With reduced energy and resource consumption, remanufactured goods are produced at a fraction of the original cost and with lower emissions of pollution. This paper presents a theoretical model of remanufacturing where a duopoly of original manufacturers produce a component of a final good. The component needing to be replaced creates an aftermarket. An environmental regulation assessing a minimum level of remanufacturability is also introduced. The main results indicate that a social planner could use collusion of the firms on the level of remanufacturability as a substitute for environmental regulation. However, if an environmental regulation is to be implemented, collusion should be repressed since competition supports the public intervention better. One of the results also coincides with the Porter Hypothesis.remanufacturing, competition, environmental regulation, Porter Hypothesis

Transboundary Movements of Waste

In a stylized model of international trade, a monopolist in the North exports second-hand products to a representative firm in the South to be reused as intermediate goods, with potential trade gains. The degree of reusability of waste products is a crucial choice variable in the North. This is because with a lack of international vigilance, non-reusable waste can be mixed illegally with the reusable waste. I explore the driving forces for the movement of illegal waste, paying particular attention to the role of local waste regulations, such as the EU's Waste Electrical and Electronic Equipment directive. Under mild conditions, it is shown that increased regulation stringency in the North leads its firm to reduce the degree of reusability of its products. As a result, the flow of non-reusable waste to the South increases, providing another channel for the Pollution Haven Hypothesis.second-hand products, illegal waste, environmental regulation, trade

Remanufacturing

This paper presents a theoretical model of remanufacturing where a duopoly of original manufacturers produces a component of a final good. The specific component that needs to be replaced during the lifetime of the final good creates a secondary market where independent remanufacturers enter the competition. An environmental regulation imposing a minimum level of remanufacturability is also introduced. The main results establish that, while collusion of the firms on the level of remanufacturability increases both profit and consumer surplus, a social planner could use collusion as a substitute for an environmental regulation. However, if an environmental regulation is to be implemented, collusion should be repressed since competition supports the public intervention better. Under certain circumstances, the environmental regulation can increase both profit and consumer surplus. Part of this result supports the Porter Hypothesis, which stipulates that industries respecting environmental regulations can see their profits increase.Remanufacturing, competition, environmental regulation, Porter hypothesis.

Soft chemistry synthesis of the perovskite CaCu3Ti4O12

The perovskite CaCu3Ti4O12 (CCT) has been obtained after calcination of oxalate precursors at 900–1000 °C in air. Those precursors are prepared using a soft chemistry method, the coprecipitation. The oxalate powders consist of disk-like particles of 2–3 μm diameter and 300–400 nm thickness. By varying the ratio of the initial amounts of metal chlorides, additional phases (CaTiO3, TiO2 and CuO) could be obtained besides CCT. The corresponding multiphased ceramics present improved dielectric properties

Internal friction investigation of phase transformation in nearly stoichiometric LaMnO3+δ

Rhombohedral LaMnO3+δ powders, prepared by two different soft chemistry routes (co-precipitation and hydrothermal synthesis), are sintered at 1400 °C for 2 h in air. Measurements of internal friction Q−1(T) and shear modulus G(T), at low frequencies from −180 to 700 °C under vacuum, evidence three structural transitions of nearly stoichiometric orthorhombic LaMnO3+δ. The first one, at 250 or 290 °C, depending on the processing followed, is associated to either a Jahn–Teller structural transition or a phase transformation from orthorhombic to pseudo-cubic. The second one at 610 or 630 °C is related to a phase transformation from pseudo-cubic or orthorhombic to rhombohedral. Below the Neel temperature, around −170 °C, a relaxation peak could be associated, for samples prepared according to both processing routes, to the motion of Weiss domains

Cosmological billiards and oxidation

We show how the properties of the cosmological billiards provide useful information (spacetime dimension and $p$-form spectrum) on the oxidation endpoint of the oxidation sequence of gravitational theories. We compare this approach to the other available methods: $GL(n,R)$ subgroups and the superalgebras of dualities.Comment: To appear in the Proceedings of the 27th Johns Hopkins Workshop and in the Proceedings of the 36th International Symposium Ahrenshoop; v2: minor error correcte

Dielectric properties of CaCu3Ti4O12 based multiphased ceramics

A “soft chemistry” method, the coprecipitation, has been used to synthesize the perovskite CaCu3Ti4O12 (CCT). Three main types of materials were obtained for both powders and sintered ceramics: a monophased consisting of the pure CCT phase, a biphased (CCT + CaTiO3), and a three-phased (CCT + CaTiO3 + copper oxide (CuO or Cu2O)). These ceramics, sintered at low temperature, 1050 °C, present original dielectric properties. The relative permittivity determined in the temperature range (−150 < T < 250 °C) is significantly higher than the one reported in the literature. Internal barrier layer capacitor is the probable mechanism to explain the particular behaviour. Moreover, the presence of a copper oxide phase beside the perovksite CCT plays an important role for enhancing the dielectric properties

Democracy, Inequality and the Environment when Citizens can Mitigate Privately or Act Collectively

We study the political economy of the environment in autocratic, weak and strong democracies when individuals can either mitigate the health consequences of domestic pollution privately or reduce pollution collectively through public policy. The setting is that of a small open economy in which incomes depend importantly on trade in dirty goods, where income inequality and the degree to which ordinary citizens exert voice in each dimension of the policy process distinguishes elites and ordinary citizens. The recognition that the health consequences of pollution can be dealt with privately at a cost adds an important dimension to the analysis of the political economy of environmental regulation, especially for an open economy. When private mitigation is feasible, inequality of incomes leads to an unequal distribution of the health burden of pollution (in accordance with the epidemiologic evidence), thus polarizing the interests of citizens in democracies and of ordinary citizens and elites in non-democratic regimes. Inequality in the willingness to bear the cost of private mitigation in turn interacts with the pollution costs and income benefits of trade in dirty goods to further polarize interests concerning both environmental stringency and the regulation of trade openness. In this context, we show how the eco-friendliness ranking of different political regimes varies with the cost of private mitigation and with the extent of income inequality, tending to converge when mitigation costs are high, and even producing a ranking reversal between democracies and autocracies, and between weak and strong democracies, when costs lie in an intermediate range.pollution, environmental regulation, private mitigation, income inequality, democracy, trade, welfare, collective choice, political economy

Large scale statistical analysis of GEO datasets

The problem addressed here is that of simultaneous treatment of several gene expression datasets, possibly collected under different experimental conditions and/or platforms. Using robust statistics, a large scale statistical analysis has been conducted over $20$ datasets downloaded from the Gene Expression Omnibus repository. The differences between datasets are compared to the variability inside a given dataset. Evidence that meaningful biological information can be extracted by merging different sources is provided