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A study of the physical properties of CdTe thin films doped with Bi is presented. CdTe:Bi thin films were deposited by the close space vapor transport (CSVT) technique using powdered CdTe:Bi crystals grown by the vertical Bridgman method. CdTe:Bi crystals were obtained with nominal Bi doping concentrations varying in the 1 1017–8 1018 cm 3 range. The physical properties of CdTe:Bi thin films were studied performing photoluminescence, X-ray, SEM, photoacoustic spectroscopy and resistivity measurements. We observed a decrease of the resistivity values of CdTe:Bi films with the Bi content as low as 6 105O-cm for Bi concentrations of 8 1018 cm 3. These are meaningful results for CdTe-based solar cells. r 2006 Published by Elsevier B.V

With the aim of increasing knowledge of community structure, dynamics and production of ectomycorrhizal fungi, edible sporocarp yields were monitored between 1995 and 2004 in a Pinus sylvestris stand in the northeast zone of the Iberian Peninsula. A random sampling design was performed by stand age class according to the forest management plan: 0-15, 16-30, 31-50, 51-70 and over 71-years-old. Eighteen 150 m plots were established and sampled weekly every year from September to December. One hundred and nineteen taxa belonging to 51 genera were collected, 40 of which were edible and represented 74% of the total biomass. Boletus edulis, Lactarius deliciosus, Cantharellus cibarius and Tricholoma portentosum sporocarps, which are considered to be of high commercial value, represented 34% of the total production. B. edulis and L. deliciosus were the most remarkable and abundant species, and both were collected in more than 60% of the samplings. B. edulis fructified every year of the experiment; its mean production was 40 kg/ha and year and its maximum productivity was more than 94 kg/ha in 1998. The age class with the largest production of this taxa was the fourth (51-70 years), with 70 kg/ha. L. deliciosus only failed to fructify one autumn (2000); its mean production was almost 10 kg/ha and its maximum productivity close to 30 kg/ha in 1997. The maximum productivity of this species was found in the second (16-30 years) and fifth (71-90 years) stand age classes, with 18 and 16 kg/ha, respectively. Advances in this field can certainly offer new insights into factors affecting sporocarp production.

The articles in this special section focus on the topic of real time demand response applications.

Abstract The development of cleaner and renewable energy sources are needed in order to reduce fossil fuel dependence and mitigate global warming by reducing greenhouse gas emissions. Solar dryers are considered as clean technologies and optimal use of these can minimize the use of non-renewable energy, and can play an important role in the world's future. Drying for forest products is one of the most attractive and cost effective application of solar energy because it may be possible to improve forest residues in profitable biomass as biofuel. In this study, a solar greenhouse dryer was used in drying experiments of wood chips of Pinus pinaster in the south of Spain. The environmental conditions were under autumn season with an average daily solar radiation of 13.74 MJ/(m 2 d) during the 15 days of the experiment. The experiment analyzed the drying process under indoor conditions of several piles of wood chips which was compared to the same shaped piles under open sun drying. The results were mathematically modelled to show the advantages of the Solar Greenhouse Dryer for both, to reach the 10% of relative humidity and fewer days were dedicated for this. Thus, these analyses reveal that the Solar Greenhouse Dryer is a useful and vital technology for the improvement of wood chips as biofuel, it reduces moisture, and it can be applied in many countries because of the fact that it only uses solar energy; it is a renewable energy resource which is both free and clean.

Deaths from the effects of alcohol intoxication are encountered routinely in forensic practice. In an important number of cases difficulty may arise in interpreting the significance of results obtained in the autopsy. In clinical practice biochemical markers, particularly serum gamma-glutamyl-transpeptidase (GGT), alanine aminotransferase (ALT), aspartate transaminase (AST), carbohydrate-deficient transferrin (CDT), and erythrocyte mean corpuscular volume are used to diagnose heavy alcohol consumption. CDT is used as a reliable and specific marker. In postmortem diagnosis, because of the difficulty in interpreting blood alcohol levels and relatively non-specific pathological features, biochemical compounds have been studied for use as possible markers. The aim of this study was to evaluate the usefulness of the postmortem determination of CDT in vitreous humor as a confirmation of antemortem alcoholism. CDT levels were studied in 66 male cadavers with a mean age of 55.9 years (S.D. 17.0, range 22-87 years) with a mean postmortem interval of 17.9 h (S.D. 11.4, range 4-72 h). Cases were assigned to two diagnostic groups according to the antemortem diagnosis of alcoholism. Statistically significant differences were found for CDT and ALT concentrations between the two diagnostic groups. The highest vitreous humor levels of CDT and ALT were obtained in the group of cases with a previous diagnosis of alcoholism. Our results suggest that vitreous humor CDT levels are useful in cases where the postmortem diagnosis of alcoholism is hindered by the non-specificity of data.

Abstract Pyrolysis is currently being considered as an alternative method of treating sewage sludge. It yields residual oils and gases, which can be used as fuels, and a solid which can either be burned or physically activated with air or CO 2 . The aim of this work was to study the influence of different pyrolysis conditions (e.g. temperature and heating rate) on the reactivity in air and in CO 2 of carbonaceous materials obtained from these types of residues. An anaerobic sewage sludge produced in a Spanish urban waste water treatment plant, containing 5 wt.% moisture after air-drying, was pyrolyzed in an electrical laboratory furnace under different pyrolysis conditions. Non-isothermal reactivities (up to 1100°C) in air and in CO 2 of the carbonaceous materials obtained after pyrolysis were performed in a thermobalance. The TG and DTG curves obtained from these experiments are discussed.

Abstract Anaerobic treatment of palm oil mill effluent (POME) was studied using a 16-litre laboratory scale up-flow anaerobic sludge blanket reactor (UASB) run over a range of influent concentrations from 5.1 to 42.5 g Chemical Oxygen Demand (COD) per litre at a constant hydraulic retention time of four days. Methane production, volatile fatty acid conversion, net sludge growth and Chemical Oxygen Demand reduction were monitored. Over 96% Chemical Oxygen Demand was removed at loadings up to 10.6 g COD l −1 day −1 . At the highest influent concentration reactor instability was observed. Up to this point the results indicated that the UASB could treat POME more effectively than other systems reviewed.

The pyrolysis of olive and grape bagasse has been studied with the aim of determining the main characteristics of the charcoals formed and the nature and quantity of gases and liquids produced. Variables investigated were temperature between 300 and 900°C and particle size between 0.4 and 2 mm diameter. Experiments were carried out in an isothermal manner. As a general rule, particle size does not exert any influence, whereas temperature is a very significant variable. Thus an increase in this variable yields an increase in the fixed carbon content, gases produced and, to a lesser extent, ash percentage. On the other hand, volatile material and solid yields decrease with increasing temperature. The principal gases generated are H2, CH4, CO and CO2, while among the liquid components the presence of methanol, acetone, furfuryl alcohol, phenol, furfural, naphthalene and o-cresol has to be highlighted. Heating values of both gas and solid phases were determined from gas composition and elemental carbon analysis. The quality of charcoals and heating value allow the conclusion that the most convenient temperature for the pyrolysis should be between 600 and 700°C, at which the production of liquids is at its maximum. Finally, a kinetic study of the pyrolysis, based on gas generation from thermal decomposition of residues, has been carried out. From this model, rate constants for the formation of each gas and their corresponding activation energies were determined.

The increase in installed wind power has brought a number of Grid Code areas into focus. The area of fault ride-through capability is one with serious implications for system security and thus has an impact on the allowed wind energy penetration in the network. There are several wind turbine models that can be used to study the effects of voltage dips and the corresponding wind turbine responses but these models need to be validated by comparing their results with the data obtained during field tests. This paper presents the design of a voltage dip generator that can be used to test wind turbines up to 5 MW and 20 kV. This system is able to adjust voltage dip depth and duration to the standards defined in different countries and also the fault impedance seen by the grid in order not to disturb its operation during the tests. Simulation results are validated using experimental data obtained at a laboratory-scale prototype (400 V, 90 kW). Finally, the actual 5 MW system and the results obtained during field tests are presented.