Formation of droplets from the liquid wall film passing through the inlet port of a spark ignition engine

The available literature has been surveyed to determine the parameters affecting fuelling requirements of spark ignition engines and their relation to engine performance and emissions. Theories and experiment relating to two phase and multi-component flows have also been examined and the techniques employed in the measurement of droplet sizes and liquid wall films have been reviewed. Following preliminary steady flow visualisation experiments to examine the trajectories of droplets discharging from the valve port an extensive practical investigation of the spectrum of droplet sizes formed by the break up of the wall film has produced results which have been correlated in terms of the important fuel and airflow parameters. It is concluded that the Sauter mean diameter of droplets formed by the break up of the wall film will vary between 70 and 150 m, depending on the operating conditions of the engine. The spectra of droplet sizes measured show that a significant proportion of the total mass of the wall film breaks into drops which will be too large to burn completely and, by comparison with measurements of unburned hydrocarbon emissions from engines supplied with a homogeneous mixture of air and gaseous hydrocarbons, it is concluded that the droplets from the wall film are likely to increase emissions by 50%.

Diagenetic processes in ore formation with special reference to the Zambian copperbelt and permian marl slate.

This thesis is concerned with the role of diagenesis in forming ore deposits. Two sedimentary 'ore-types' have been examined; the Proterozoic copper-cobalt orebodies of the Konkola Basin on the Zambian Copperbelt, and the Permian Marl Slate of North East England. Facies analysis of the Konkola Basin shows the Ore-Shale to have formed in a subtidal to intertidal environment. A sequence of diagenetic events is outlined from which it is concluded that the sulphide ores are an integral part of the diagenetic process. Sulphur isotope data establish that the sulphides formed as a consequence of the bacterial reduction of sulphate, while the isotopic and geochemical composition of carbonates is shown to reflect changes in the compositions of diagenetic pore fluids. Geochemical studies indicate that the copper and cobalt bearing mineralising fluids probably had different sources. Veins which crosscut the orebodies contain hydrocarbon inclusions, and are shown to be of late diagenetic lateral secretion origin. RbiSr dating indicates that the Ore-Shale was subject to metamorphism at 529 A- 20 myrs. The sedimentology and petrology of the Marl Slate are described. Textural and geochemical studies suggest that much of the pyrite (framboidal) in the Marl Slate formed in an anoxic water column, while euhedral pyrite and base metal sulphides formed within the sediment during early diagenesis. Sulphur isotope data confirm that conditions were almost "ideal" for sulphide formation during Marl Slate deposition, the limiting factors in ore formation being the restricted supply of chalcophile elements. Carbon and oxygen isotope data, along with petrographic observations, indicate that much of the calcite and dolomite occurring in the Marl Slate is primary, and probably formed in isotopic equilibrium. A depositional model is proposed which explains all of the data presented and links the lithological variations with fluctuations in the anoxicioxic boundary layer of the water column.

Sedimentology, palaeontology and diagenesis of the Much Wenlock limestone formation

Lithofacies distribution indicates that the Much Wenlock Limestone Formation of England and South Wales was desposited on a shelf which was flat and gently subsiding in the north, but topographically variable in the south. Limestone deposition in the north began with 12m of alga-rich limestone, which formed an upward shoaling sequence. Deepening then led to deposition of calcareous silty mudstones on the northern shelf. The remainder of the formation in this area formed during a shelf-wide regression, culminating in the production of an E to W younging sandbody. Lithofacies distribution on the southern shelf was primarily controlled by local subsidence. Six bedded lithofacies are recognised which contain 14 brachiopod/bryozoan dominated assemblages, of which 11 are in situ and three consist of reworked fossils. Microfacies analysis is necessary to distinguish assemblages which reflect original communities from those which reflect sedimentary processes. Turbulence, substrate-type, ease of feeding and other organisms in the environment controlled faunal distribution. Reefs were built dominantly by corals, stromatoporoids, algae and crinoids. Coral/stromatoporoid (Type A) reefs are common, particularly on the northern shelf, where they formed in response to shallowing, ultimately growing in front of the advancing carbonate sandbody. Algae dominate Type B and Type C reefs, reflecting growth in areas of poor water circulation. Lithification of the formation began in the marine-phreatic environment with precipitation of aragonite and high Mg calcite, which was subsequently altered to turbid low Mg calcite. Younger clear spars post-date secondary void formation. The pre-compactional clear spars have features which resemble the products of meteoric water diagenesis, but freshwater did not enter the formation at this time. The pre-compactional spars were precipitated by waters forced from the surrounding silty mudstones at shallow burial depths. Late diagenetic products are stylolites, compaction fractures and burial cements.

The formation and impact of hazard control policy:a study of the regulation of white lead paint in Britain

Government regulation of industrial hazards is examined in the context of the economic and technical processes of industrial development. Technical problems and costs of control are considered as factors in both the formation and impact of regulation. This thesis focuses on an historical case-study of the regulation of the hazard to painting workers from the use of lead pigments in paint. A regulatory strategy based on the prohibition of lead paints gained initial acceptance within the British state in 1911, but was subsequently rejected in favour of a strategy that allowed continued use of lead paint subject to hygiene precautions. The development of paint technology and its determinants, including concern about health hazards, are analysed, focusing on the innovation and diffusion into the paint industry of the major white pigments: white lead (PbC03 .PB(OH)2)and its substitutes. The process of regulatory development is examined, and the protracted and polarised regulatory d~bate contrasted to the prevailing 'consensual' methods of workplace regulation. The rejection of prohibition is analysed in terms of the different political and technical resources of those groups in conflict over this policy. This highlights the problems of consensus formation around such a strategy, and demonstrates certain constraints on state regulatory activity, particularly regarding industrial development. Member-states of the International Labour Organisation agreed to introduce partial prohibition of lead paint in 1921. Whether this was implemented is related to the economic importance of lead and non-lead metal and pigment industries to a nation. An analysis is made of the control of lead poisoning. The rate of control is related to the economic and technological trajectory of the regulated industry. Technical and organisational characteristics are considered as well as regulatory factors which range from voluntary compliance and informal pressures to direct legal requirements. The implications of this case-study for the analysis of the development and impacts of regulation are assessed.

Consumer responses to really new products: examining the impacts of learning strategies and presentation formats on product comprehension and attitude formation

Mental simulations and analogies have been identified as powerful learning tools for RNPs. Furthermore, visuals in advertising have recently been conceptualized as meaningful sources of information as opposed to peripheral cues and thus may help consumers learn about RNPs. The study of visual attention may also contribute to understanding the links between conceptual and perceptual analyses when learning for a RNP. Two conceptual models are developed. the first model consists of causal relationships between the attributes of advertising stimuli for RNPs and consumer responses, as well as mediating influences. The second model focuses on the role of visual attention in product comprehension as a response to advertising stimuli. Two experiments are conducted: a Web-Experiment and an eye-tracking experiment. The first experiment (858 subjects) examines the effect of learning strategies (mental simulation vs. analogy vs. no analogy/no mental simulation) and presentation formats (words vs. pictures) on individual responses. The mediating role of emotions is assessed. The second experiment investigates the effect of learning strategies and presentation formats on product comprehension, along with the role of attention (17 subjects). The findings from experiment 1 indicate that learning strategies and presentation formats can either enhance or undermine the effect of advertising stimuli on individual responses. Moreover, the nature of the product (i.e. hedonic vs. utilitarian vs. hybrid) should be considered when designing communications for RNPs. The mediating role of emotions is verified. Experiment 2 suggests that an increase in attention to the message may either reflect enhanced comprehension or confusion.

Spray dried combinations of lactoferrin with antibiotics appear superior to monotherapy for reducing biofilm formation by pseudomonas aeruginosa

SD Apo Lactoferrin-Tobramycin/Gentamicin Combinations are superior to monotherapy in the eradication of Pseudomonas aeruginosa Biofilm in the lungs Wilson Oguejiofor1, Lindsay J. Marshall1, Andrew J. Ingham1, Robert Price2, Jag. Shur2 1School of Life and Health Sciences, Aston University, Birmingham, UK. 2School of Pharmacy and Pharmacology, University of Bath, Bath, UK. KEYWORDS: lactoferrin, apo lactoferrin, spray drying, biofilm, cystic fibrosis Introduction Chronic lung infections from the opportunistic pathogeen Pseudomonas aeruginosa has been recognised as a major contributor to the incidences of high morbidity and mortality amongst cystic fibrosis (CF) patients (1,2). Currently, strategies for managing lung infections in CF patients involves the aggressive use of aerosolised antibiotics (3), however, increasing evidence suggests that the biofilm component of P. aeruginosa in the lower airway remains unperturbed and is associated with the development of antibiotic resistance. If this is so then, there is an urgent need to suitably adjust the current treatment strategy so that it includes compounds that prevent biofilm formation or disrupt established biofilms. It is well understood that biofilm formation is strongly dependent on iron (Fe3+) availability (4), therefore aerosolised anti-infective formulations which has the ability to chelate iron may essentially be a well suited therapy for eliminating P. aeruginosa biofilms on CF airway epithelial cells (5). In this study, we report the use of combination therapy; an aminoglycosides (tobramycin and gentamicin) and an antimicrobial peptide (lactoferrin) to significantly deplete P. aeruginosa biofilms. We demonstrate that lactoferrin-tobramycin and lactoferrin-gentamicin combinations are superior to the single antibiotic regime currently being employed to combat P. aeruginosa biofilms. MATERIALS AND METHOD Antibiotics: The antibiotics used in this study included gentamicin and tobramycin supplied by Fagron, UK. Bacterial strain and growth conditions: Pseudomonas aeruginosa strain PAO1 was provided by Prof. Peter Lambert of Aston University, Birmingham UK. The Strains were routinely grown from storage in a medium supplemented with magnesium chloride, glucose and casamino acids. Dialysis of lactoferrin: Apo lactoferrin was prepared by dialyzing a suspension of lactoferrin for 24 hrs at 4 °C against 20 mmol/L sodium dihydrogen phosphate, 20 mmol/L sodium acetate and 40 mmol/L EDTA (pH 3.5). Ferric ion (Fe3+) removal was verified by atomic absorption spectroscopy measurements. Spray drying of combinations of lactoferrin and apo lactoferrin with the different aminoglycosides: Combinations of tobramycin and gentamicin with the different preparations of lactoferrin were spray dried (SD) as a 2% (w/v) aqueous suspension. The spray drying parameters utilized for the production of suitable micron-sized particles includes: Inlet temperature, 180°C, spray flow rate, 606 L/hr; pump setting, 10%; aspirator setting, 85% (34m3/hr) to produce various outlet temperatures ranging from 99 - 106°C. Viability assay: To test the bactericidal activity of the various combinations, a viability assay was performed as previously described by Xu, Xiong et al. (6) with some modifications. Briefly, 10µL of ~ c. 6.6 x 107 CFU mL-1 P. aeruginosa strain PAO1 suspension were incubated (37°C, 60 mins) with 90 µL of a 2 µg/mL concentration of the various combinations and sampled every 10 mins. After incubation, the cells were diluted in deionised water and plated in Mueller hinton agar plates. Following 24 h incubation of the plates at 37°C, the percentage of viable cells was determined relative to incubation without added antibiotics. Biofilm assay: To test the susceptibility of the P. aeruginosa strain to various antibiotics in the biofilms mode of growth, overnight cultures of P. aeruginosa were diluted 1:100 into fresh medium supplemented with magnesium chloride, glucose and casamino acids. Aliquots of the dilution were dispensed into a 96 well dish and incubated (37°C, 24 h). Excess broth was removed and the number of colony forming units per milliliter (CFU/mL) of the planktonic bacteria was quantified. The biofilms were then washed and stained with 0.1% (w/v) crystal violet for 15 mins at room temperature. Following vigorous washing with water, the stained biofilms were solubilized in 30% acetic acid and the absorbance at 550nm of a 125 µL aliquot was determined in a microplate reader (Multiskan spectrum, Thermo Scientific) using 30% acetic acid in water as the blank. Aliquots of the broth prior to staining were used as an indicator of the level of planktonic growth. RESULTS AND DISCUSSION Following spray drying, the mean yield, volume weighted mean diameter and moisture content of lactoferrin powder were measured and were as follows (Table 1 and table 2); Table 1: Spray drying parameters FormulationInlet temp (°C)Outlet temp (°C)Airflow rate (L/hr)Mean yield (%)Moisture content (%) SD Lactoferrin18099 - 10060645.2 ±2.75.9 ±0.4 SD Apo Lactoferrin180100 - 10260657.8 ±1.85.7 ±0.2 Tobramycin180102 - 10460682.1 ±2.23.2 ±0.4 Lactoferrin + Tobramycin180104 - 10660687.5 ±1.43.7 ±0.2 Apo Lactoferrin + Tobramycin180103 - 10460676.3 ±2.43.3 ±0.5 Gentamicin18099 - 10260685.4 ±1.34.0 ±0.2 Lactoferrin + Gentamicin180102 - 10460687.3 ±2.13.9 ±0.3 Apo Lactoferrin + Gentamicin18099 -10360680.1±1.93.4 ±0.4 Table 2: Particle size distribution d10 d50d90 SD Lactoferrin1.384.9111.08 SD Apo Lactoferrin1.284.7911.04 SD Tobramycin1.254.9011.29 SD Lactoferrin + Tobramycin1.175.2715.23 SD Apo Lactoferrin + Tobramycin1.115.0614.31 SD Gentamicin1.406.0614.38 SD Lactoferrin + Gentamicin1.476.2314.41 SD Apo Lactoferrin + Gentamicin1.465.1511.53 The bactericidal activity of the various combinations were tested against P. aeruginosa PAO1 following a 60 minute incubation period (Figure 1 and Figure 2). While 2 µg/mL of a 1:1 combination of spray dried apo lactoferrin and Gentamicin was able to completely kill all bacterial cells within 40 mins, the same concentration was not as effective for the other antibiotic combinations. However, there was an overall reduction of bacterial cells by over 3 log units by the other combinations within 60 mins. Figure 1: Logarithmic plot of bacterial cell viability of various combinations of tobramycin and lactoferrin preparations at 2µg/mL (n = 3). Figure 2: Logarithmic plot of bacterial cell viability of various combinations of gentamicin and lactoferrin preparations at 2µg/mL (n = 3). Crystal violet staining showed that biofilm formation by P. aeruginosa PAO1 was significantly (ANOVA, p < 0.05) inhibited in the presence of the different lactoferrin preparations. Interestingly, apo lactoferrin and spray dried lactoferrin exhibited greater inhibition of both biofilm formation and biofilm persistence (Figure 2). Figure 2: Crystal violet staining of residual biofilms of P. aeruginosa following a 24hr incubation with the various combinations of antibiotics and an exposure to 48 hr formed biofilms. CONCLUSION In conclusion, combination therapy comprising of an antimicrobial peptide (lactoferrin) and an aminoglycosides (tobramycin or gentamicin) provides a feasible and alternative approach to monotherapy since the various combinations are more efficient than the respective monotherapy in the eradication of both planktonic and biofilms of P. aeruginosa. ACKNOWLEDGEMENT The authors would like to thank Mr. John Swarbrick and Friesland Campina for their generous donation of the Lactoferrin. REFERENCES 1.Hassett, D.J., Sutton, M.D., Schurr, M.J., Herr, A.B., Caldwell, C.C. and Matu, J.O. (2009), "Pseudomonas aeruginosa hypoxic or anaerobic biofilm infections within cystic fibrosis airways". Trends in Microbiology, 17, 130-138. 2.Trust, C.F. (2009), "Antibiotic treatment for cystic fibrosis". Report of the UK Cystic Fibrosis Trust Antibiotic Working Group. Consensus document. London: Cystic Fibrosis Trust. 3.Garcia-Contreras, L. and Hickey, A.J. (2002), "Pharmaceutical and biotechnological aerosols for cystic fibrosis therapy". Advanced Drug Delivery Reviews, 54, 1491-1504. 4.O'May, C.Y., Sanderson, K., Roddam, L.F., Kirov, S.M. and Reid, D.W. (2009), "Iron-binding compounds impair Pseudomonas aeruginosa biofilm formation, especially under anaerobic conditions". J Med Microbiol, 58, 765-773. 5.Reid, D.W., Carroll, V., O'May, C., Champion, A. and Kirov, S.M. (2007), "Increased airway iron as a potential factor in the persistence of Pseudomonas aeruginosa infection in cystic fibrosis". European Respiratory Journal, 30, 286-292. 6.Xu, G., Xiong, W., Hu, Q., Zuo, P., Shao, B., Lan, F., Lu, X., Xu, Y. and Xiong, S. (2010), "Lactoferrin-derived peptides and Lactoferricin chimera inhibit virulence factor production and biofilm formation in Pseudomonas aeruginosa". J Appl Microbiol, 109, 1311-1318.

Using min-sum loopy belief propagation for decentralised supply chain formation

Modern business trends such as agile manufacturing and virtual corporations require high levels of flexibility and responsiveness to consumer demand, and require the ability to quickly and efficiently select trading partners. Automated computational techniques for supply chain formation have the potential to provide significant advantages in terms of speed and efficiency over the traditional manual approach to partner selection. Automated supply chain formation is the process of determining the participants within a supply chain and the terms of the exchanges made between these participants. In this thesis we present an automated technique for supply chain formation based upon the min-sum loopy belief propagation algorithm (LBP). LBP is a decentralised and distributed message-passing algorithm which allows participants to share their beliefs about the optimal structure of the supply chain based upon their costs, capabilities and requirements. We propose a novel framework for the application of LBP to the existing state-of-the-art case of the decentralised supply chain formation problem, and extend this framework to allow for application to further novel and established problem cases. Specifically, the contributions made by this thesis are: • A novel framework to allow for the application of LBP to the decentralised supply chain formation scenario investigated using the current state-of-the-art approach. Our experimental analysis indicates that LBP is able to match or outperform this approach for the vast majority of problem instances tested. • A new solution goal for supply chain formation in which economically motivated producers aim to maximise their profits by intelligently altering their profit margins. We propose a rational pricing strategy that allows producers to earn significantly greater profits than a comparable LBP-based profitmaking approach. • An LBP-based framework which allows the algorithm to be used to solve supply chain formation problems in which goods are exchanged in multiple units, a first for a fully decentralised technique. As well as multiple-unit exchanges, we also model in this scenario realistic constraints such as factory capacities and input-to-output ratios. LBP continues to be able to match or outperform an extended version of the existing state-of-the-art approach in this scenario. • Introduction of a dynamic supply chain formation scenario in which participants are able to alter their properties or to enter or leave the process at any time. Our results suggest that LBP is able to deal easily with individual occurences of these alterations and that performance degrades gracefully when they occur in larger numbers.

The formation and properties of some cyclic compounds of silicon an dtin

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