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Wood biomass is turned into industrial fuel through chipping. The efficiency of chipping depends on many factors, including chipper knife wear. Chipper knife wear was determined through a long-term follow-up study, conducted at a waste wood recycling yard. Knife wear determined a sharp drop of productivity (>20%) and a severe decay in product quality. Dry sharpening with a grinder mitigated this effect, but it could not replace proper wet sharpening. Increasing the frequency of wet sharpening sessions determined a moderate increase of knife depreciation cost, but it could drastically enhance machine performance and reduce biomass processing cost. Since benefits largely exceed costs, increasing the frequency of wet sharpening sessions may be an effective measure for reducing overall chipping cost. If the main goal of a chipper operator is to increase productivity and/or decrease fuel consumption, then managing knife wear should be a primary target. (C) 2014 Elsevier Ltd. All rights reserved.

Ostrava in the Moravian-Silesian region (Czech Republic) is a European air pollution hot spot for airborne particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and ultrafine particles (UFPs). Air pollution source apportionment is essential for implementation of successful abatement strategies. UFPs or nanoparticles of diameter <100 nm exhibit the highest deposition efficiency in human lungs. To permit apportionment of PM sources at the hot-spot including nanoparticles, Positive Matrix Factorization (PMF) was applied to highly time resolved particle number size distributions (NSD, 14 nm-10 μm) and PM0.09-1.15 chemical composition. Diurnal patterns, meteorological variables, gaseous pollutants, organic markers, and associations between the NSD factors and chemical composition factors were used to identify the pollution sources. The PMF on the NSD reveals two factors in the ultrafine size range: industrial UFPs (28%, number mode diameter - NMD 45 nm), industrial/fresh road traffic nanoparticles (26%, NMD 26 nm); three factors in the accumulation size range: urban background (24%, NMD 93 nm), coal burning (14%, volume mode diameter - VMD 0.5 μm), regional pollution (3%, VMD 0.8 μm) and one factor in the coarse size range: industrial coarse particles/road dust (2%, VMD 5 μm). The PMF analysis of PM0.09-1.15 revealed four factors: SIA/CC/BB (52%), road dust (18%), sinter/steel (16%), iron production (16%). The factors in the ultrafine size range resolved with NSD have a positive correlation with sinter/steel production and iron production factors resolved with chemical composition. Coal combustion factor resolved with NSD has moderate correlation with SIA/CC/BB factor. The organic markers homohopanes correlate with coal combustion and the levoglucosan correlates with urban background. The PMF applications to NSD and chemical composition datasets are complementary. PAHs in PM1 were found to be associated with coal combustion factor.

The paper presents a method of analysis and design of urban landscapes called PlaceMaker. The method is intended as a key resource for assessing the identity of places and measures for its enhancement, reconstruction and design. By using different tools for analysis and interpretation of places and questionnaires administered to their users, PlaceMaker finds the identity material that the city has available and how to de-compose and re-compose it for its sustainable project transformation. Pedestrian-intensive areas, in particular urban, cultural and historical poles of attraction, increasingly bear the imprint of globalization, conveying messages which have developed in an uncontrolled manner and are aimed at conveying their users' patterns of thought and action. The presence of a dense mixture of contrasting elements and perceptions can detract from the image of a city. As regards, the paper is completed with a synopsis of the experiment carried out in an historic axe in London - Oxford Street - where globalization is in danger of levelling out the beauty of the area in favour of widespread genericity

The oleaginous alga Chlorella protothecoides accumulates lipid in its biomass when grown in nitrogen-restricted conditions. To assess the relationship between nitrogen provision and lipid accumulation and to determine the contribution of photosynthesis in mixotrophic growth, C. protothecoides was grown in mixo- and heterotrophic nitrogen-limited continuous flow cultures. Lipid content increased with decreasing C/N, while biomass yield on glucose was not affected. Continuous production of high lipid levels (57% of biomass) was possible at high C/N (87-94). However, the lipid production rate (2.48 g L(-1) d(-1)) was higher at D=0.84 d(-1) with C/N 37 than at D=0.44 d(-1) and C/N 87 even though the lipid content of the biomass was lower (38%). Photosynthesis contributed to biomass and lipid production in mixotrophic conditions, resulting in 13-38% reduction in CO2 production compared with heterotrophic cultures, demonstrating that photo- and heterotrophic growth occurred simultaneously in the same population.

The Indian Ocean Experiment (INDOEX) was an international, multiplatform field campaign to measure long-range transport of air pollution from South and Southeast Asia toward the Indian Ocean during the dry monsoon season in January to March 1999. Surprisingly high pollution levels were observed over the entire northern Indian Ocean toward the Intertropical Convergence Zone at about 6°S. We show that agricultural burning and especially biofuel use enhance carbon monoxide concentrations. Fossil fuel combustion and biomass burning cause a high aerosol loading. The growing pollution in this region gives rise to extensive air quality degradation with local, regional, and global implications, including a reduction of the oxidizing power of the atmosphere.

Artículos en revistas Advanced Metering Infrastructures (AMI) represent one of the first steps in the Smart Grid process, where Power Line Communication (PLC) is emerging as the most costeffective solution since it allows reusing electric infrastructures as communication channel. However, the performance of this technology is highly affected by the characteristics of the existing distribution network. This article presents a thorough sensitivity analysis to assess the operating limits of smart metering applications for multiple representative configurations of low voltage (LV) networks based on a PLC simulation framework that integrates DLMS/COSEM and PRIME standards. The number of registered nodes and the time to read all meters have been defined as Key Performance Indicators to assess the communication performance. The conclusions drawn from this study provide useful information for the integration of smart meter applications that take advantage of AMI under different local conditions. info:eu-repo/semantics/publishedVersion

The paper presents a computer simulation of the operation of three independent electric drives with a periodic load, connected to a common power supply network. Two cases are considered - operation of electric drives in one phase and in different phases. An analysis of their impact on the electrical supply network is carried out, the results are compared with the permissible Russian standards. An analytical optimization method based on the analysis of power graphs of electric drives with periodic load was considered. The article contains an overview of possible methods for regulating the working phase of the mechanism.

Changes in the composition, structure, and altitudinal distribution of low forests at the upper limit of their growth over the past 50 years have been studied in the Tylaisko-Konzhakovsko-Serebryanskii Massif (the Northern Urals). The qualitative and quantitative assessment of these changes has been made on the basis of descriptions, photographs, and maps made in 1956 and 2005. The results show that the upper boundary of low forests on the majority of slopes has ascended. Considerable changes have occurred in the composition, density, and height of the tree layer in the communities that formed the upper low-forest boundary in 1956. Among a fairly large number of tree species growing in the subgoltzy belt (Picea obovata, Larix sibirica, Pinus sibirica, and Abies sibirica), the birch Betula tortuosa has expanded most actively, whereas the proportions of P. obovata and especially L. sibirica in low forests have decreased. These changes are explained by climate warming and increasing humidity.