• Energy Research
• Restricted close
• Embargo close
• engineering and technology close
• RU close
• IN close

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.

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

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.

Results of the innovative development of an efficiently controlled, new-generation, energy-saving, industrial AC electric drive are presented. The drive is based on a two-link cycloconverter without a filter in the intermediate link. The improved energy and electromagnetic compatibility with the supply mains are important advantages of new-generation converters.

Abstract The aim of the present study was to assess the influence of substrate concentration on the fermentative hydrogen production from sweet sorghum extract, in a continuous stirred tank bioreactor. The reactor was operated at a Hydraulic Retention Time (HRT) of 12 h and carbohydrate concentrations ranging from 9.89 to 20.99 g/L, in glucose equivalents. The maximum hydrogen production rate and yield were obtained at the concentration of 17.50 g carbohydrates/L and were 2.93 ± 0.09 L H 2 /L reactor/d and 0.74 ± 0.02 mol H 2 /mol glucose consumed, corresponding to 8.81 ± 0.02 L H 2 /kg sweet sorghum, respectively. The main metabolic product at all steady states was butyric acid, while ethanol production was high at high substrate concentrations. The experiments showed that hydrogen productivity depends significantly on the initial carbohydrate concentration, which also influences the distribution of the metabolic products.

The main performance characteristics of the turbine, descriptions of the electrohydraulic control and protection system (EHCPS), the heat flow diagram, arrangement decisions, and motivation for selecting them, are given. The steam turbine presented by the Ural Turbine Works (UTW) is intended for replacing the VPT-25 turbine the service life of which has already expired at the Novokuybyshevsk CHP plant. The mixed-pressure turbine will operate in combination of the double-circuit heat recovery boiler (HRB) in a parallel scheme. High-pressure (HP) steam will be supplied from the main steam header to which high-pressure steam from the power boilers and the HRB will be fed, while low-pressure (LP) steam will be supplied directly from the HRB. For the turbine, nozzle steam distribution and the two-row control stage are adopted. The turbine has a process steam extraction line with its stop and control valve and heating steam extraction line leading to the main steam collector.

Coordinate pulsewidth modulation is considered for the control of power switches of matrix and two-component direct frequency converters (DFC) in ac drive systems. The synthesis of modulating signals yielding the specified output voltages and sinusoidal grid currents for converters with no intermediate smoothing filter is discussed. Simulation of DFC operation with an RLE load and an asynchronous motor is undertaken.