Effects of Changing Drive Control Method of Idling Wood Size Reduction Machines on Fuel Consumption and Exhaust Emissions

Operating conditions often fluctuate during processing of branches and sawmill offcuts using low-power wood size reduction machines (WSRMs), mainly due to changes in wood supply frequency. This results in relatively high proportions of idling time. Fuel consumption and associated exhaust emissions of WSRMs with combustion engines can be reduced by using innovative drive unit control systems during idling. The objective of the research was to determine the effects of two speed control systems on the fuel consumption and exhaust emissions of a WSRM with a two-cylinder cutting mechanisms driven by a small 9.5 kW spark ignition engine. Speed control system A (commercially available) had a substantially higher rotational speed than system B (an innovative, adaptive solution subject to patent application No. P433586). Pine (Pinus sylvestris L.) wood sawmill offcuts (average cross-sectional area, length and water content: 25×40 mm, 3000 mm and ca. 12, respectively) were used in system tests at a feed rate of ca. 5 pieces min-1. Material of this size is typically processed by such machines. Operating conditions were monitored by recording the rotational speed and torque. Emissions of harmful exhaust compounds–carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), and nitrogen oxides (NOx) – were recorded using a portable emission measurement system. Fuel consumption values were also calculated from the data. The following effects were observed: application of innovative system B resulted in 33% lower fuel consumption, as well as 30%, 37% and 33% lower CO, CO2 and NOx emissions, respectively, than system A, but at the same time 290% higher HC emissions were registered. In operating conditions with higher proportions of idling time, solution B provides even higher reductions in fuel consumption and exhaust emissions

Electron Paramagnetic Resonance and Electron Spin Echo Studies of Co2+ Coordination by Nicotinamide Adenine Dinucleotide (NAD+) in Water Solution

Co(2+) binding to the nicotinamide adenine dinucleotide (NAD(+)) molecule in water solution was studied by electron paramagnetic resonance (EPR) and electron spin echo at low temperatures. Cobalt is coordinated by NAD(+) when the metal is in excess only, but even in such conditions, the Co/NAD(+) complexes coexist with Co(H(2)O)(6) complexes. EPR spin-Hamiltonian parameters of the Co/NAD(+) complex at 6 K are g(z) = 2.01, g(x) = 2.38, g(y) = 3.06, A(z) = 94 × 10(−4) cm(−1), A(x) = 33 × 10(−4) cm(−1) and A(y) = 71 × 10(−4) cm(−1). They indicate the low-spin Co(2+) configuration with S = 1/2. Electron spin echo envelope modulation spectroscopy with Fourier transform of the modulated spin echo decay shows a strong coordination by nitrogen atoms and excludes the coordination by phosphate and/or amide groups. Thus, Co(2+) ion is coordinated in pseudo-tetrahedral geometry by four nitrogen atoms of adenine rings of two NAD(+) molecules

MAESTRO, CASTRO, and SEDONA -- Petascale Codes for Astrophysical Applications

Performing high-resolution, high-fidelity, three-dimensional simulations of Type Ia supernovae (SNe Ia) requires not only algorithms that accurately represent the correct physics, but also codes that effectively harness the resources of the most powerful supercomputers. We are developing a suite of codes that provide the capability to perform end-to-end simulations of SNe Ia, from the early convective phase leading up to ignition to the explosion phase in which deflagration/detonation waves explode the star to the computation of the light curves resulting from the explosion. In this paper we discuss these codes with an emphasis on the techniques needed to scale them to petascale architectures. We also demonstrate our ability to map data from a low Mach number formulation to a compressible solver.Comment: submitted to the Proceedings of the SciDAC 2010 meetin

Rapeseed Oil Methyl Esters (RME) as Fuel for Urban Transport

The use of biofuels is justified by the common agricultural policy decisions, by the need to improve environment protection and by the search of alternative energy sources. In such a context, methyl esters of vegetable oils, known as biodiesel and ethyl alcohol are receiving increasing attention as alternative fuels for automotive engines. The main advantages of biodiesel and ethyl alcohol are that these fuels are nontoxic, biodegradable, and renewable with the potential to reduce engine exhaust emissions, especially with regard to greenhouse gases emission. The fact that these biofuels are available in larger and larger quantities is of great importance as well. Currently, in the European market the most important biofuel is FAME (Fatty Acid Methyl Esters) manufactured mainly as Rapeseed Methyl Esters (RME). It is forecasted that the scale of production and consumption of this fuel will continue increasing as a result of the growing demand for diesel fuels and a levelled demand for spark-ignition engine fuels. Currently, FAME is added to regular diesel fuels in the amount of up to 7%. Besides, its consumption in a pure form grows as well. This chapter presents ecological properties of RME in relation to conventional diesel fuel. The aim of the research was to determine the potential of RME in reducing exhaust emissions (CO, HC, NOx and PM) from diesel engines operated in buses. The tests were carried out in real operating conditions of a city bus meeting EEV emissions standard. Comparative analysis made it possible to assess the environmental performance of buses depending on the type of fuel used. The obtained results indicate a slightly lower emission of CO, HC and PM when the vehicle was fuelled with RME but at the same time its application results in a slight increase in the emission of NOx. It seems that similar level of exhaust emissions recorded regardless of fuel type results from an advanced exhaust gas aftertreatment system (SCR + DPF) which was applied in the test vehicle

Measurement of Exhaust Emissions under Actual Operating Conditions with the Use of PEMS: Review of Selected Vehicles

This paper is a synthetic approach to real driving (RDE) from selected vehicles: light-duty vehicle (LDV), heavy-duty vehicle (HDV). The tests were performed with the portable emission measurement system (PEMS) equipment under actual traffic conditions. The paper discusses problems of measurement methodology and emission of CO, HC, NOx, and PM. The performed investigation confirms that the main problem is the emission of NOx and PM, which usually is higher than the emission level. The obtained results show that the RDE method is very complex, but is the only way to provide invaluable information on the actual on-road exhaust emissions, not obtainable under laboratory conditions. In recent years, methods of exhaust emission testing under actual operating conditions have been developing rapidly. New technologies for extra low engine emissions pose a new question: does emission testing in a standard laboratory reflects real life emissions of a vehicle in use? In order to answer this question, it is necessary to measure the vehicle in-use emissions. Today, we know that the engine operating conditions (engine load and speed) in laboratory tests are not compliant with the conditions of actual operation. That is why the results of such tests are so desirable

Environmental Aspects of the Use of CNG in Public Urban Transport

This chapter concerns the problem of assessing the exhaust emission from the engines of city transport buses fuelled by CNG. It presents a comparative analysis of toxic exhaust emissions of CO, HC, NOx and PM, from urban buses powered by diesel and CNG. The measurements were carried out over the SORT standardised cycles as well as during a real drive condition on a city bus route. The research revealed that CNG bus generates significantly lower NOx emission, whereas its CO and HC emissions are higher. Taking into account low PM emissions, CNG buses should be regarded as eco-friendly means of public transport