The Influence of Fatty Acid Ester Alcohol Moiety Molecular Structure on Diesel Combustion and Emissions

At present, biodiesel is primarily comprised of fatty acid methyl esters (FAMEs) obtained by the transesterification of a variety of vegetable oils with methanol. However, transesterification can be carried out with a wide variety of alcohols other than methanol. This paper presents experimental studies carried out on a diesel engine supplied with a range of single-molecule fuels to investigate the effect of fuel molecular structure on combustion and emissions. Eight fatty acid esters that can be produced by transesterification of vegetable oils and animal fats using methanol, ethanol, n-propanol, n-butanol, iso-propanol, iso-butanol, and tert-butanol were investigated. The aim was to ascertain the way in which the structure of the alcohol reactant and the corresponding moiety in the ester molecule affects combustion and emissions. Previously obtained experimental results from a second set of 18 nonoxygenated acyclic hydrocarbons were used to assist the interpretation of the test results from the eight fatty acid esters. The engine tests were carried out at constant injection timing, and they were repeated at constant ignition timing and at constant ignition delay, the latter being achieved through the addition to the various fuels of small quantities of ignition improver (2-ethyl hexyl nitrate). Only small differences in ignition quality of the fatty acid esters were found with variation of the molecular structure of the alcohol moiety. Where present, differences in ignition delay were found to be the main driver of both combustion phasing and emissions production. With the effect of ignition delay isolated, physical properties of the esters, such as thermal degradation prior to vaporization and boiling point, were found to exert an influence on levels of particulate and NOx emissions

Combustion and emissions characteristics of toluene/n-heptane and 1-octene/n-octane binary mixtures in a direct injection compression ignition engine

Successfully designing and making effective of use of the next generation of liquid fuels, which will be derived from a range of biomass and fossil sources, requires an understanding of the interactions between structurally similar and dissimilar fuel components when utilised in current engine technology. Interactions between fuel components can influence the release of energy and production of harmful emissions in compression ignition combustion through determination of the autoignition behavior of the fuel. This paper presents experimental studies carried out in a single-cylinder engine supplied with a range of binary mixture fuels to investigate the effect of fuel component interactions on autoignition in direct injection compression ignition. A range of binary mixtures consisting of toluene and n-heptane and also 1-octene and n-octane were tested so as to observe respectively the effect of an aromatic compound and an alkene on n-alkane combustion and emissions. The engine tests were carried out at constant injection timing and they were repeated at constant ignition timing and at constant ignition delay, the latter being achieved through the addition to the various fuels of small quantities of ignition improver (2-ethylhexyl nitrate). Increasing the presence of toluene in the toluene/n-heptane binary mixtures resulted in an increased ignition delay time and generated a distinct two stage ignition process. An increased level of 1-octene in the binary mixtures of 1-octene/n-octane was also found to increase ignition delay, though to a much lesser extent than toluene in the case of the toluene/n-heptane mixtures. Interactions between the fuel components during the ignition delay period appear important in the case of the toluene/n-heptane mixtures but not those of 1-octene/n-octane. At constant injection and constant ignition timings, the combustion phasing and the level of emissions produced by each binary mixture were primarily driven by the ignition delay time. With ignition delay equalised, an effect of adiabatic flame temperature on NOx production was visible

Associatons Between Self-Reported Well-being and Neuromuscular Performance During a Professional Rugby Union Season.

Associatons between self-reported well-being and neuromuscular performance during a professional rugby union season. J Strength Cond Res 32(9): 2498-2509, 2018-Self-reported wellness is often used to monitor fatigue responses to training and competition. Constraints within team sports mean short-form wellness questionnaires are typically preferred to literature-validated documents. This research aimed to assess the relationship between self-reported wellness and neuromuscular (NM) performance during a professional rugby union season, and to identify changes in these parameters over a 12-week period. On the first training day each week, before activity, 37 players rated 5 wellness subscales ("fatigue/vigor," "upper-body soreness," "lower-body soreness," "mood," and "sleep quality/duration") on a 1-5 Likert scale (1 representing the lowest wellness), and 5-repetition countermovement jumps (CMJs) were completed after a warm-up. Each week, total wellness, wellness subscales, and 4 CMJ measures for each participant were calculated as change from baseline. Within-participant correlations were determined between changes in wellness and CMJ measures, whereas week-to week differences and differences from baseline were assessed using Wilcoxon signed-rank tests. Within-participant correlations were compared for players grouped by age and position. Wellness and CMJ scores fluctuated according to physical stress, persisted beneath baseline throughout, and showed declining trends over 12 weeks. Very large (r = 0.7-0.89)/large (r = 0.5-0.69) correlations were identified between wellness and CMJ variables (positive: velocity, dip, time; negative: duration), and each wellness subscale displayed large/very large positive correlations with CMJ velocity. This was true for all subgroups, although subtle differences existed between ages and positions. It was concluded that players' subjective wellness is a useful tool, ideally used within a broader monitoring scheme, for monitoring ongoing NM fatigue, which increased from week to week

Consultancy-Based Projects

This chapter will:; ; ; Show how consultancy work can inform business discourse teaching;; ; ; Discuss how needs analysis and communication audits can be used to generate recommendations for teaching and training;; ; ; Profile a number of consultancy-based business discourse projects and show how they have informed training and course development;; ; ; Provide a case study, together with a set of tasks appropriate for the business discourse classroom, and a set of further readings

Minimising medicine use in organic dairy herds through animal health and welfare planning

Livestock is important in many organic farming systems, and it is an explicit goal to ensure high levels of animal health and welfare (AHW) through good management. This will lead to reduced medicine use and better quality of animal products. In two EU network projects NAHWOA & SAFO it was concluded that this is not guaranteed merely by following organic standards. Both networks recommended implementation of individual animal health plans to stimulate organic farmers to improve AHW. These plans should include a systematic evaluation of AHW and be implemented through dialogue with each farmer in order to identify goals and plan improvements. 15 research institutions in 8 European countries are involved in the proposed project with the main objective to minimise medicine use in organic dairy herds through active and well planned AHW promotion and disease prevention. The project consists of 5 work packages, 4 of which comprise research activities building on current research projects, new applications across borders, exchange of knowledge, results and conclusions between participating countries, and adopting them to widely different contexts. International and national workshops facilitate this exchange. Focus areas are animal health planning, AHW assessment using animal based parameters and development of advisory systems and farmer groups. Epidemiological analyses of the effect on AHW from reduced medicine use and herd improvements are planned in all participating countries

Investigating MgII Absorption in Paired Quasar Sight-Lines

We test whether the Tinker & Chen model of MgII absorption due to the gaseous halo around a galaxy can reproduce absorption in quasar pairs (both lensed and physical) and lensed triples and quads from the literature. These quasars exhibit absorption from a total of 38 MgII systems spanning z=0.043 - 2.066 with mean redshift =1.099 and weighted mean rest-frame equivalent width of 0.87 Ang. Using the Tinker & Chen model to generate simulated sight-lines, we marginalize the unknown parameters of the absorbing galaxies: dark matter halo mass, impact parameter, and azimuthal angle on the sky. We determine the ability of the model to statistically reproduce the observed variation in MgII absorption strength between paired sight-lines for different values of the gas covering fraction f_c and the characteristic length scale ell_c, within which the variation in absorption equivalent widths between sight-lines exponentially decreases. We find a best-fit f_c=0.60 \pm 0.15 and ell_c<8/h_70 kpc (1\sigma confidence limits), with smaller f_c allowed at larger ell_c. At 99.7% confidence, we are able to rule out f_c>0.87 for all values of ell_c and the region where ell_c<1.0/h_70 kpc and f_c<0.3.Comment: 24 pages, 11 figures, 2 tables, accepted for publication in MNRAS, 1 Dec 201

Maternal–Fetal Microtransfusions and HIV-1 Mother-to-Child Transmission in Malawi

Background: Between 25% and 35% of infants born to HIV-infected mothers become HIV-1 infected. One potential route of mother-to-child transmission (MTCT) could be through a breakdown in the placental barrier (i.e., maternal–fetal microtransfusions). Methods and Findings: Placental alkaline phosphatase (PLAP) is a 130-kD maternal enzyme that cannot cross the intact placental barrier. We measured PLAP activity in umbilical vein serum as an indicator of maternal–fetal microtransfusion, and related this to the risk of HIV-1 MTCT. A case-cohort study was conducted of 149 women randomly selected from a cohort of HIV-1-infected pregnant Malawians; these women served as a reference group for 36 cases of in utero MTCT and 43 cases of intrapartum (IP) MTCT. Cord PLAP activity was measured with an immunocatalytic assay. Infant HIV status was determined by real-time PCR. The association between cord PLAP activity and HIV-1 MTCT was measured with logistic regression using generalized estimating equations. Among vaginal deliveries, PLAP was associated with IP MTCT (risk ratio, 2.25 per $log_{10}$ ng/ml PLAP; 95% confidence interval, 0.95–5.32) but not in utero MTCT. In a multivariable model adjusted for HIV-1 RNA load, chorioamnionitis, and self-reported fever, the risk of IP MTCT almost tripled for every $log_{10}$ increase in cord PLAP activity (risk ratio, 2.87; 95% confidence interval, 1.05–7.83). Conclusion: These results suggest that during vaginal deliveries, placental microtransfusions are a risk factor for IP HIV-1 MTCT. Future studies are needed to identify factors that increase the risk for microtransfusions in order to prevent IP HIV-1 MTCT

CEO pay, shareholder returns, and accounting profits

We assess the impact on CEO pay (including salary, cash bonus, and benefits in kind) of changes in both accounting and shareholder returns in 99 British companies in the years 1972-89. After correcting for heterogeneity biases inherent in the standard specifications of the problem, we find a strong positive relationship between CEO pay and within-company changes in shareholder returns, and no statistically significant relationship between CEO pay and within-company changes in accounting returns. Differences between firms in long-term average profitability do appear to have a substantial effect on CEO pay, while differences between firms in shareholder returns add nothing to the within-firm pay dynamics.These findings call into question the rationale for explicitly share-based incentive schemes