No abstract

The reduction of emissions from diesel engines has been a key element in obtaining air quality and greenhouse gas reduction goals. Biodiesel is an important alternative fuel for diesel applications, but there is a tendency for biodiesel to increase nitrogen oxides (NO x) emissions, which remains an issue in nonattainment areas. This study investigated the effect of using low blend level biodiesel fuels and fuel additives on emissions. Emissions from three B5 biodiesel fuels and six B20-soybean oil methyl ester (SME) with additive blends were evaluated as potential biodiesel formulations for California. B5-SME and B5-waste cooking oil methyl ester (WCOME) both showed measurable increases in NO x emissions, while a B5-animal fat methyl ester (AFME) showed a slight reduction or no change in NO x emissions compared to the CARB diesel. The B5-AFME blend also passed the criteria of the CARB diesel emissions equivalent certification test. Of the additives tested, only one provided reductions in NO x emissions for the B20-SME blends, but the reductions were not enough to pass the CARB diesel emissions equivalent certification test at the B20 level. Biodiesel blends generally showed either reductions or no significant changes in particulate matter (PM), total hydrocarbon (THC), and carbon monoxide (CO) emissions.

Dyed textiles are, in general, less resistant to colour change when weathered than when exposed behind glass to daylight. No standard method exists for the assessment of weathering fastness. An outdoor weathering test and a wet fading lamp test are described, and their merits and deficiencies discussed. The method of assessment allows direct comparison between the weathering (or wet‐fading‐lamp) fastness of a pattern and the light fastness according to B.S. 1006. These methods have yielded useful results in practice, and this paper records some work carried out to date.

The California Air Resources Board (CARB) has regulated the properties of diesel fuel sold in California since 1988 to lower emissions of particulate matter (PM) and oxides of nitrogen (NO x ). Although many studies have shown that reduced levels of aromatics and higher cetane numbers can improve emissions, the actual impact of CARB fuels on inuse diesel emissions has not yet been extensively studied, especially as diesel engine and aftertreatment technology has evolved over the years. This study evaluates the differences between California and Federal diesel fuels with heavy-duty engine and chassis dynamometer tests. The engine dynamometer results showed that NO x emissions for the Federal fuels ranged from 4.7% to 9.5% higher than the CARB diesel. These NO x reductions are similar to the estimates being used in the latest regulations. The chassis dynamometer test results did not show as consistent trends for NO x as those seen for the engine dynamometer testing. For the chassis dynamometer testing, four out of ten vehicles showed consistent reductions in NO x , with emissions for the Federal fuels ranging from 3.3% to 9.9% higher than the CARB diesel, while the other six vehicles did not show consistent fuel impacts. On an absolute level, the NO x benefit for CARB diesel shows a decline with continuing advances in engine technology. The results showed that CARB diesel did not show strong benefits for PM. The results also showed that the introduction of aftertreatment systems for PM and NO x will, over time, largely eliminate any potential benefits that might be obtained through the use of CARB diesel, although NO x benefits will persist through to 2020.