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Repeated treatment of rats with ethanol (1 g/kg, once daily for 15 days) enhanced the locomotor effect of morphine, 3 weeks post-treatment. This ethanol-induced long-term behavioural sensitization to morphine was associated with an increase in the electrically evoked release of [3H]dopamine (DA) and [14C]acetylcholine (ACh) from nucleus accumbens slices. A similar enhanced responsiveness of accumbal dopaminergic and cholinergic neurons to depolarization was apparent 3 weeks after repeated morphine, amphetamine or cocaine administration. Prior ethanol exposure also caused a long-term enhancement of electrically evoked release of [3H]DA and [14C]ACh from slices of the caudate-putamen. Unlike the locomotor effect of morphine, that of amphetamine was not enhanced in ethanol-pretreated rats. These data indicate that ethanol administration may cause long-term behavioural sensitization associated with adaptive changes in dopaminergic and cholinergic neurons of rat nucleus accumbens and caudate-putamen. Furthermore, an enhanced reactivity of nucleus accumbens dopaminergic nerve terminals and dopamine-sensitive cholinergic neurons appears to be a common long-term neuroadaptive effect of distinct types of addictive drugs. However, since repeated ethanol exposure did not cause a long-term increase in the locomotor effect of amphetamine, these neuroadaptations may not always be sufficient to cause long-lasting behavioural (cross-)sensitization.

Abstract Life Cycle Assessment (LCA) has been conducted for seven experimental cubicles located in Puigverd de Lleida (Spain). The objective of this experimental set-up is to test different constructive solutions in order to point out the most sustainable solution with lower energy demand during the operational phase. Therefore, different building, insulation and Phase Change Materials (PCMs) have been tested under controlled temperature conditions to examine the thermal performance of the whole system. Although some of these materials are able to reduce the energy demand and consequently the environmental impact during the operational phase, they still have high embodied energy that can cause high environmental impact during the manufacturing phase. Therefore the LCA study in this paper focuses on assessing the impact of the embodied energy needed during the manufacturing and disposal phase by highlighting and comparing the effect of using different building materials, insulating materials, and phase change materials.

Studies addressing the role of large herbivores on nitrogen cycling in grasslands have suggested that the direction of effects depends on soil fertility. Via selection for high quality plant species and input of dung and urine, large herbivores have been shown to speed up nitrogen cycling in fertile grassland soils while slowing down nitrogen cycling in unfertile soils. However, recent studies show that large herbivores can reduce nitrogen mineralization in some temperate fertile soils, but not in others. To explain this, we hypothesize that large herbivores can reduce nitrogen mineralization in loamy or clay soils through soil compaction, but not in sandy soils. Especially under wet conditions, strong compaction in clay soils can lead to periods of soil anoxia, which reduces decomposition of soil organic matter and, hence, N mineralization. In this study, we use a long-term (37-year) field experiment on a salt marsh to investigate the hypothesis that the effect of large herbivores on nitrogen mineralization depends on soil texture. Our results confirm that the presence of large herbivores decreased nitrogen mineralization rate in a clay soil, but not in a sandy soil. By comparing a hand-mown treatment with a herbivore-grazed treatment, we show that these differences can be attributed to herbivore-induced changes in soil physical properties rather than to above-ground biomass removal. On clay soil, we find that large herbivores increase the soil water-filled porosity, induce more negative soil redox potentials, reduce soil macrofauna abundance, and reduce decomposition activity. On sandy soil, we observe no changes in these variables in response to grazing. We conclude that effects of large herbivores on nitrogen mineralization cannot be understood without taking soil texture, soil moisture, and feedbacks through soil macrofauna into account.

Syngas deriving from biomass gasification is receiving increased interest as an alternative fuel in spark ignition (SI) engines for power generation, despite problems related to the variability of its composition and the low energy density. Syngas release from gasifiers is indeed strongly affected by the quality of the feedstock and by the specific features and control strategy of the reactor. The paper considers the possibility to achieve, at the same time, high efficiency and low pollutant emissions of a syngas powered engine by acting on operating variables as the spark timing and the air-to-fuel ratio, with also the possible inclusion of exhaust gas recirculation (EGR). Model-based design and multi-objective optimization methods are applied as a feasible approach to address this issue, hence to improve the energetic and the environmental performances of power generation under a flexible fuel quality. A one-dimensional (1D) model of a naturally aspirated SI engine fuelled by syngas, properly developed and validated through a specific experimental campaign, is here presented to investigate the effect of the main controlling variables on power output and emissions. A proper design of experiment (DoE) space is considered. The 1D model is coupled with a genetic optimization algorithm for the search of the best compromise solution between maximum performance and minimum pollutants amount. The identified optimal solution allows a reduction up to the 50% for both nitrogen oxides and carbon monoxide emissions with a negligible worsening of the power output.

In this work, a promising technique, consisting of a liquid Water Injection (WI) at the intake ports, is investigated to overcome over-fueling and delayed combustions typical of downsized boosted engines, operating at high loads. In a first stage, experimental tests are carried out in a spark-ignition twin-cylinder turbocharged engine at a fixed rotational speed and medium-high loads. In particular, a spark timing and a water-to-fuel ratio sweep are both specified, to analyze the WI capability in increasing the knock-limited spark advance. In a second stage, the considered engine is schematized in a 1D framework. The model, developed in the GT-Power(TM) environment, includes user defined procedures for the description of combustion and knock phenomena. Computed results are compared with collected data for all the considered operating conditions, in terms of average performance parameters, in-cylinder pressure cycles, burn rate profiles, and knock propensity, as well. Finally, the validated model is applied to investigate the full potential of water injection in reducing the knock tendency and improving the fuel economy in a wide load range. The numerical results highlight that WI technique involves significant Brake Specific Fuel Consumption (BSFC) advantages, especially at the medium-high loads. These benefits are limited by the maximum allowable levels for the in-cylinder pressure, while additional advantages are obtained in terms of reduced turbine inlet temperature, turbocharger speed, and boost pressure. The developed numerical procedure, based on validated combustion and knock sub-models, is able to take into account the complex interactions among different parameters, which affect the engine behavior. It is hence believed to realistically forecast the WI-related BSFC advantages and constraints, induced by thermo-mechanical stresses. Simultaneously, it underlines the need of a partial engine redesign to fully exploit WI potential.

Modern fuels are an important enabler of social and economic development. Still, over 2 billion people rely on traditional biomass for their daily energy needs. To overcome the negative effects of traditional energy on human health and the environment and to enhance the livelihood conditions of the poor, a transition towards cleaner and more efficient forms of energy is needed. Understanding household fuel choice and fuel switching behaviour is of vital importance in search for policies to support such a transition process. This paper adds to the existing energy transition literature in two ways. First, we provide a novel conceptual framework to analyze the decision environment underlying energy and fuel choices. Second, we apply this framework in a meta-analysis of existing choice models investigating energy switching and stacking behaviour in urban and rural areas in developing countries. The meta-analysis shows that socio-economic household characteristics appear to receive most attention so far in identifying groups of fuel users, while relatively little information is available on the impact of the external decision context on household energy choices. © 2012 Elsevier Ltd.

The gaseous and liquid products of the fixed-bed pyrolysis of agricultural residues (hazelnut shells, olive pomace, straw pellets) and wood (beech wood and softwood pellets) are chemically characterized and compared. The heating temperature is varied in the range 473-800 K but the process occurs in the presence of large thermal overshoots. These reach their maxima for heating temperatures below (residues, overshoots up to about 225 K) or above (wood, overshoots up to about 85 K) approximately 650 K. Though mainly originated from secondary decomposition, overheating also highly enhances the primary decomposition rates, globally leading to short volatile residence times. As a consequence, the product distribution is modified. In particular, at low heating temperatures, also following pyrolytic runaway, the residues produce the largest amounts of volatiles and the yields of several condensable organic compounds (acetic acid, propionic acid, formic acid, hydroxypropanone, levoglucosan, guiacols and syringols) reach their maxima, with even qualitative deviations from the usual trends observed in pyrolysis.