Effects of an on line bypass oil recycler on emissions with oil age for a bus using in service testing

A method of cleaning lubricating oil on line was investigated using a fine bypass particulate filter followed by an infra red heater. Two bypass filter sizes of 6 and 1 micron were investigated, both filter sizes were effective but the one micron filter had the greatest benefit. This was tested on two nominally identical EURO 2 emissions compliance single decker buses, fitted with Cummins 6 cylinder 8.3 litre turbocharged intercooled engines and coded as Bus 4063 and 4070. These vehicles had emissions characteristics that were significantly different, in spite of their similar age and total mileage. Bus 4063 showed an apparent deterioration on emissions with time while Bus 4070 showed a stabilised trend on emissions with time for their baseline tests without the recycler fitted. Comparison was made with the emissions on the same vehicles and engines with and without the on-line bypass oil recycler. Engine exhaust emissions were measured about every 2000 miles. All tests started with an oil drain and fresh lubricating oil. The two buses were tested in a different sequence, Bus 4063 with the recycler fitted and then removed later in the test after an oil change and Bus 4070 with no recycler fitted at first and then fitted after 29,000 miles with no oil change. The Bus 4070 was also the one with the finer bypass filter. The test mileage was 45,000 miles for Bus 4063 and 48,000 miles for Bus 4070. The air/fuel ratio was worked out by the exhaust gas analysis. The correlation between air/fuel ratio and emission parameters was determined. The results showed that the on line oil recycler cleaning system reduced the rate of increase of the NOx from 5% to 1.6% for Bus 4063 and from 4.1% to 0% for Bus 4070 per 10,000 miles. Hydrocarbon emissions increased 30 ppm per 10,000 miles with the recycler removed compared to a stabilised level with the recycler fitted for Bus 4063. There was a small decrease in hydrocarbon emissions after fitting the recycler for Bus 4070. The particulate emissions were reduced by 35% for Bus 4063 and 24% for Bus 4070 on average. The reductions on total particulate mass were due to reductions on particulate carbon and lube oil VOF emissions. The black smoke was reduced by 56% for Bus 4063 in terms of rate of increase and 40% for Bus 4070 in terms of average value

The influence of an oil recycler on emissions with oil age for a refuse truck using in service testing

A method of cleaning lubricating oil on line was investigated using a fine bypass particulate filter followed by an infra red heater. Two bypass filter sizes of 6 and 1 micron were investigated, both filter sizes were effective but the one micron filter had the greatest benefit. This was tested on two nominally identical EURO 1 emissions compliance refuse trucks, fitted with Perkins Phazer 210Ti 6 litre turbocharged intercooled engines and coded as RT320 and RT321. These vehicles had emissions characteristics that were significantly different, in spite of their similar age and total mileage. RT321 showed an apparent heavier black smoke than RT320. Comparison was made with the emissions on the same vehicles and engines with and without the on-line bypass oil recycler. Engine exhaust emissions were measured about every 400 miles. Both vehicles started the test with an oil drain and fresh lubricating oil. The two refuse trucks were tested in a different sequence, the RT320 without the recycler fitted and then fitted later and the RT321 with the recycler fitted and then removed later in the test and both without any oil change. The RT320 was also the one with the finer bypass filter. The test mileage was nearly 8,000 miles both trucks. The air/fuel ratio was worked out by the exhaust gas analysis. The correlation between air/fuel ratio and emission parameters was determined and appropriate corrections were made in the case of that the air/fuel ratio had an effect on emissions. The results showed that the on line oil recycler cleaning system can reduce the rate of increase of the NOx with oil age. There appeared little influence of the oil recycler on carbon monoxide and hydrocarbon emissions. The rate of increase in particulate emissions was reduced by 50% for RT320 and an immediate decrease in particulate emissions was seen on RT320 test after fitting the recycler. The black smoke was reduced by 30% for RT320 in terms average value and an immediate decrease in smoke after fitting the recycler on RT320 test and an immediate increase in smoke after the removal of the recycler on RT321 test were shown

Oil quality in diesel engines with on line oil cleaning using a heated lubricating oil recycler

A method of cleaning the oil on line was investigatedusing a bypass fine particulate filter followed by an infra red heater to remove water and light diesel fractions in the oil. This was tested on a range of on road vehicles and a Ford 1.8 litre IDI passenger car engine on a test bed. Comparison was made with the oil quality on the same vehicles and engines without the on-line recycler. Test times were from 200 to 1500 hours of oil ageing and some of the tests showed that the oil quality was still good after 4 times the normal oil life. The results showed that the on line oil recycler cleaning system reduced the rate of fall of the TBN and rate of increase of the TAN. There was a very significant reduction in the soot in oil and the fuel dilution. There was also a consistent reduction in all the wear metals apart from copper and a decrease in the rate of reduction of oil additives. There was also measured on the Ford IDI engine a 5% reduced fuel consumption. Many of these effects were attributed to an influence of the cleaner oil on reduced engine deposits

Oil quality in diesel engines with on line oil cleaning using a heated lubricating oil recycler

A method of cleaning the oil on line was investigatedusing a bypass fine particulate filter followed by an infra red heater to remove water and light diesel fractions in the oil. This was tested on a range of on road vehicles and a Ford 1.8 litre IDI passenger car engine on a test bed. Comparison was made with the oil quality on the same vehicles and engines without the on-line recycler. Test times were from 200 to 1500 hours of oil ageing and some of the tests showed that the oil quality was still good after 4 times the normal oil life. The results showed that the on line oil recycler cleaning system reduced the rate of fall of the TBN and rate of increase of the TAN. There was a very significant reduction in the soot in oil and the fuel dilution. There was also a consistent reduction in all the wear metals apart from copper and a decrease in the rate of reduction of oil additives. There was also measured on the Ford IDI engine a 5% reduced fuel consumption. Many of these effects were attributed to an influence of the cleaner oil on reduced engine deposits

Simple Statistical Probabilistic Forecasts of the winter NAO

The variability of the North Atlantic Oscillation (NAO) is a key aspect of Northern Hemisphere atmospheric circulation and has a profound impact upon the weather of the surrounding landmasses. Recent success with dynamical forecasts predicting the winter NAO at lead times of a few months has the potential to deliver great socioeconomic impacts. Here, a linear regression model is found to provide skillful predictions of the winter NAO based on a limited number of statistical predictors. Identified predictors include El Niño, Arctic sea ice, Atlantic SSTs, and tropical rainfall. These statistical models can show significant skill when used to make out-of-sample forecasts, and the method is extended to produce probabilistic predictions of the winter NAO. The statistical hindcasts can achieve similar levels of skill to state-of-the-art dynamical forecast models, although out-of-sample predictions are less skillful, albeit over a small period. Forecasts over a longer out-of-sample period suggest there is true skill in the statistical models, comparable with that of dynamical forecasting models. They can be used both to help evaluate and to offer insight into the sources of predictability and limitations of dynamical models

Drivers and potential predictability of summer time North Atlantic polar front jet variability

The variability of the North Atlantic polar front jet stream is crucial in determining summer weather around the North Atlantic basin. Recent extreme summers in western Europe and North America have highlighted the need for greater understanding of this variability, in order to aid seasonal forecasting and mitigate societal, environmental and economic impacts. Here we find that simple linear regression and composite models based on a few predictable factors are able to explain up to 40% of summertime jet stream speed and latitude variability from 1955 onwards. Regression models covering the earlier part of the twentieth century are much less effective, presumably due to decreased availability of data, and increased uncertainty in observational reanalyses. Sea surface temperature (SST) forcings impact predominantly on jet speed, whereas solar and cryospheric forcings appear to influence jet latitude. The cryospheric associations come from the previous autumn, suggesting the survival of an ice-induced signal through the winter season, whereas solar influences lead jet variability by a few years. Wavelet coherence analysis identifies that associations fluctuate over the study period but it is not clear whether this is just internal variability or actual non-stationarity. Finally we identify areas for future research

Corporate control and multiple large shareholders

Many firms have more than one blockholder, but finance theory suggests that one blockholder should be sufficient to bestow all benefits on a firm that arise from concentrated ownership. This paper identifies a reason why more blockholders may arise endogenously. We consider a setting where multiple shareholders have endogenous conflicts of interest depending on the size of their stake. Such conflicts arise because larger shareholders tend to be less well diversified and would therefore prefer the firm to pursue more conservative investment policies. When the investment policy is determined by a shareholder vote, a single blockholder may be able to choose an investment policy that is far away from the dispersed shareholders' preferred policy. Anticipating this outcome reduces the price at which shares trade. A second blockholder (or more) can mitigate the conflict by shifting the voting outcome more towards the dispersed shareholders' preferred investment policy and this raises the share price. The paper derives conditions under which there are blockholder equilibria.The model shows how different ownership structures affect firm value and the degree of underpricing in an IPO

USING HISTORIC SITES IN DETERMINING PLANT-SOIL INTERACTIONS UNDER LONG TERM CONTAMINATED SOILS

The relationships between heavy metals in soils and crop tissues are critical in understanding the potential risk to crop yields from Zn, Cu and Ni (the principal phytotoxic elements of concern in sludge), and the possible effects on dietary Cd (the critical zootoxic element that is labile in sludge-treated soil and readily absorbed by plants. These relationships cannot be derived from the agronomic trials because the quantities of heavy metals applied to the soil in sludge are small. These are field sites have been treated with sludge for many years in operational practice and where the oncentrations of heavy metals have been significantly raised above background values, representing potentially a worse-case of soil contamination. The purpose of the study was to provide a surrogate for long-term sludge-treated agricultural soil by examining the effects on crops of heavy metals in soil irrigated with raw sewage effluent for periods of more than 80 years and containing significantly elevated concentrations of heavy metals. Methodology: Two surveys of the Gabal El Asfar Old Farm were undertaken to assess the long-term effects of heavy metals in sludge-treated soil on crop quality. In the first survey, the relationships between total and DTPA extractable heavy metals in soil and concentrations in citrus fruit were examined. Concentrations of heavy metals in leaves of citrus were measured in the second survey and related to total and DTPA extractable metals in soil. The heavy metal contents of citrus leaves and fruit (orange - eleven sampling sites; mandarin - four sampling sites), and total and DTPA extractable concentrations in soils were measured in samples collected from different areas of the Farm during two site surveys. Total and DTPA concentrations of heavy metals in the surveyed soils showed significant enrichment by long-term irrigation with sewage effluent. For example, the maximum total concentrations of Zn and Cu were 530 and 366 mg kg-1, respectively, representing a potential risk to crop yields The maximum Cd concentration detected was 9 mg kg-1 and may be a potential risk to the human food chain from uptake into staple crops grown at the farm. DTPA extractable metals were significantly (P<0.001) correlated with the total contents of Zn (r=0.91***), Cu (r=0.83***), Ni (r=0.63***) and Pb (r=0.85***) in soil when data from both surveys were pooled for statistical evaluation. There was also evidence of a weak relationship between DTPA extractable Cd and the total soil Cadmium is the only element of concern in terms of the risk to human health from uptake into food crops grown on sludge-treated soil. The total Cd concentration in soil was raised to a value 3 times the maximum EU limit for this element in sludge-treated agricultural soil. Despite the marked increase in soil Cd content, there was no detectable transfer into citrus leaves or fruit (Figure 1). The absence of Cd uptake into citrus fruit is to be expected because fruits are amongst the least sensitive plant parts to Cd accumulation. These data emphasise the minimal risk to the human diet from Cd in fruit crops grown on sludge-treated soil. . In all cases, leaf tissue concentrations were low and in some cases Cu status was below the deficiency threshold. The Cd content in leaves was small and generally <0.02 mg kg-1 DM.

Species compositions of elasmobranchs caught by three different commercial fishing methods off southwestern Australia, and biological data for four abundant bycatch species

Commercial catches taken in southwestern Australian waters by trawl fisheries targeting prawns and scallops and from gillnet and long-line fisheries targeting sharks were sampled at different times of the year between 2002 and 2008. This sampling yielded 33 elasmobranch species representing 17 families. Multivariate statistics elucidated the ways in which the species compositions of elasmobranchs differed among fishing methods and provided benchmark data for detecting changes in the elasmobranch fauna in the future. Virtually all elasmobranchs caught by trawling, which consisted predominantly of rays, were discarded as bycatch, as were approximately a quarter of the elasmobranchs caught by both gillnetting and longlining. The maximum lengths and the lengths at maturity of four abundant bycatch species, Heterodontus portusjacksoni, Aptychotrema vincentiana, Squatina australis, and Myliobatis australis, were greater for females than males. The L50 determined for the males of these species at maturity by using full clasper calcification as the criterion of maturity did not differ significantly from the corresponding L50 derived by using gonadal data as the criterion for maturity. The proportions of the individuals of these species with lengths less than those at which 50% reach maturity were far greater in trawl samples than in gillnet and long-line samples. This result was due to differences in gear selectivity and to trawling being undertaken in shallow inshore waters that act as nursery areas for these species. Sound quantitative data on the species compositions of elasmobranchs caught by commercial fisheries and the biological characteristics of the main elasmobranch bycatch species are crucial for developing strategies for conserving these important species and thus the marine ecosystems of which they are part

A Pragmatic Approach to the Continuum Spectrum in Quasifree Scattering

This work was supported by the National Science Foundation Grant NSF PHY 81-14339 and by Indiana Universit