Influence of iodine value on combustion and NOx emission characteristics of a DI diesel engine

Biodiesel is a renewable fuel that has been shown to reduce many exhaust emissions, except oxides of nitrogen (NOx), in diesel engine cars. This is of special concern in inner urban areas that are subject to strict environmental regulations, such as EURO norms. Also, the use of pure biodiesel (B100) is inhibited because of its higher NOx emissions compared to petroleum diesel fuel. The aim of this present work is to investigate the effect of the iodine value and cetane number of various biodiesel fuels obtained from different feed stocks on the combustion and NOx emission characteristics of a direct injection (DI) diesel engine. The biodiesel fuels were chosen from various feed stocks such as coconut, palm kernel, mahua (Madhuca indica), pongamia pinnata, jatropha curcas, rice bran, and sesame seed oils. The experimental results show an approximately linear relationship between iodine value and NOx emissions. The biodiesels obtained from coconut and palm kernel showed lower NOx levels than diesel, but other biodiesels showed an increase in NOx. It was observed that the nature of the fatty acids of the biodiesel fuels had a significant influence on the NOx emissions. Also, the cetane numbers of the biodiesel fuels are affected both premixed combustion and the combustion rate, which further affected the amount of NOx formation. It was concluded that NOx emissions are influenced by many parameters of biodiesel fuels, particularly the iodine value and cetane number.

AC/DC electrical characteristics of epoxy-multi wall carbon nanotube nanocomposites

Expoxy nanocomposites with multiwell carbon nanotubes (mwcnts) filler up to 0.3%wt were prepared by sheer mixing and good dispersion of the MWCNTS in the epoxy was successfully achieved. The electrical behaviour was characterized by measurements of the alternating current (ac) and direct current (dc) conductives at room temperature. Typical percolation behaviour was observed at a low percolation threshold of 0.055%. Frequency independent ac conductivity was observed at low frequencies but not at high frequencies. An equivalent circuit models was used to predict the impedence response in these nanocomposites.

Examination of relationships between urban form, household activities, and time allocation in the Atlanta Metropolitan Region

A substantial body of research is focused on understanding the relationships between socio-demographics, land-use characteristics, and mode specific attributes on travel mode choice and time-use patterns. Residential and commercial densities, inter-mixing of land uses, and route directness in conjunction with transportation performance characteristics interact to influence accessibility to destinations as well as time spent traveling and engaging in activities. This study uniquely examines the activity durations undertaken for out-of-home subsistence; maintenance, and discretionary activities. Also examined are total tour durations (summing all activity categories within a tour). Cross-sectional activities are obtained from household activity travel survey data from the Atlanta Metropolitan Region. Time durations allocated to weekdays and weekends are compared. The censoring and endogeneity between activity categories and within individuals are captured using multiple equations Tobit models. The analysis and modeling reveal that land-use characteristics such as net residential density and the number of commercial parcels within a kilometer of a residence are associated with differences in weekday and weekend time-use allocations. Household type and structure are significant predictors across the three activity categories, but not for overall travel times. Tour characteristics such as time-of-day and primary travel mode of the tours also affect traveler's out-of-home activity-tour time-use patterns.

Lateral shearing interferometry, dynamic wavefront sensing, and high-speed videokeratoscopy for noninvasive assessment of tear film surface characteristics : a comparitive study

There are several noninvasive techniques for assessing the kinetics of tear film, but no comparative studies have been conducted to evaluate their efficacies. Our aim is to test and compare techniques based on high-speed videokeratoscopy (HSV), dynamic wavefront sensing (DWS), and lateral shearing interferometry (LSI). Algorithms are developed to estimate the tear film build-up time TBLD, and the average tear film surface quality in the stable phase of the interblink interval TFSQAv. Moderate but significant correlations are found between TBLD measured with LSI and DWS based on vertical coma (Pearson's r2=0.34, p<0.01) and higher order rms (r2=0.31, p<0.01), as well as between TFSQAv measured with LSI and HSV (r2=0.35, p<0.01), and between LSI and DWS based on the rms fit error (r2=0.40, p<0.01). No significant correlation is found between HSV and DWS. All three techniques estimate tear film build-up time to be below 2.5 sec, and they achieve a remarkably close median value of 0.7 sec. HSV appears to be the most precise method for measuring tear film surface quality. LSI appears to be the most sensitive method for analyzing tear film build-up.

Phenothiazine UVA dosimeter : characteristics and performance

This paper provides an overview of the characteristics of a phenothiazine-mylar dosimeter which can be used as an effective solar UVA exposure assessment tool. This dosimeter is sensitive to UVA wavelengths (315–400 nm); its performance has been characterized in a series of tests such as (a) UVA exposure response (dose-response), (b) temperature stability of the response, (c) impact of long term storage, and (d) angular response. There is no effect of long term storage post-exposure and no effect of temperature up to 30 °C. For angles up to 70°, the cosine error of the normalized UVA is less than approximately 0.1. These characterizations have confirmed the reliability and reproducibility of a phenothiazine-mylar combined dosimeter as an effective solar UVA exposure tool for field-based studies of the UVA exposures to population groups.

Biomass burning influenced particles characteristics in Northern Territory Australia based on airborne measurements

Airborne measurements of particle number concentrations from biomass burning were conducted in the Northern Territory, Australia, during June and September campaigns in 2003, which is the early and the late dry season in that region. The airborne measurements were performed along horizontal flight tracks, at several heights in order to gain insight into the particle concentration levels and their variation with height within the lower boundary layer (LBL), upper boundary layer (UBL), and also in the free troposphere (FT). The measurements found that the concentration of particles during the early dry season was lower than that for the late dry season. For the June campaign, the concentration of particles in LBL, UBL, and FT were (685 ± 245) particles/cm3, (365 ± 183) particles/cm3, and (495 ± 45) particle/cm3 respectively. For the September campaign, the concentration of particles were found to be (1233 ± 274) particles/cm3 in the LBL, (651 ± 68) particles/cm3 in the UBL, and (568 ± 70) particles/cm3 in the FT. The particle size distribution measurements indicate that during the late dry season there was no change in the particle size distribution below (LBL) and above the boundary layer (UBL). This indicates that there was possibly some penetration of biomass burning particles into the upper boundary layer. In the free troposphere the particle concentration and size measured during both campaigns were approximately the same.

Damage localisation in beams and plates using vibration characteristics

Dynamic computer simulation techniques are used to develop and apply a multi-criteria procedure, incorporating changes in natural frequencies, modal flexibility and the modal strain energy, for damage localisation in beams and plates. Numerically simulated modal data obtained through finite element analyses are used to develop algorithms based on changes of modal flexibility and modal strain energy before and after damage and used as the indices for assessment of the state of structural health. The proposed procedure is illustrated through its application to flexural members under different damage scenarios and the results confirm its feasibility for damage assessment.

User characteristics of transit oriented developments : the case of Kelvin Grove Urban Village

Transit oriented developments are high density mixed use developments located within short and easily walkable distance of a major transit centre. These developments are often hypothesised as a means of enticing a mode shift from the private car to sustainable transport modes such as, walking, cycling and public transport. However, it is important to gather evidence to test this hypothesis by determining the travel characteristics of transit oriented developments users. For this purpose, travel surveys were conducted for an urban transit oriented development currently under development. This chapter presents the findings from the preliminary data analysis of the travel surveys. Kelvin Grove Urban Village, a mixed use development located in Brisbane, Australia, has been selected as the case for the transit oriented developments study. Travel data for all groups of transit oriented development users ranging from students to shoppers, and residents to employees were collected. Different survey instruments were used for different transit oriented development users to optimise their response rates, and the performance of these survey instruments are stated herein. The travel characteristics of transit oriented development users are reported in this chapter by explaining mode share, trip length distribution, and time of day of trip. The results of the travel survey reveal that Kelvin Grove Urban Village users use more sustainable modes of transport as compared to other Brisbane residents.

Self-service technology and the moderating effects of consumer characteristics

The incidence of self-service technology, where the consumer delivers the service themselves using technology, is increasing in the service encounter. One area that is under-explored is the potential impact of self-service technology on consumer satisfaction and affective commitment. Accordingly, this paper presents an empirical study that investigates the relative impact of self-service technology on consumer satisfaction (both overall and transaction-specific) and affective commitment, accounting for the moderating effects of consumer characteristics. The results highlight the importance of personal service for evaluations of satisfaction and commitment, and the importance of social competency as a moderator in this relationship. An understanding of these consumer perceptions will allow organisations to develop strategies to deliver the services expected by their consumers, improving consumer satisfaction and commitment.

The impacts of traffic and rainfall characteristics on heavy metals build-up and wash-off from urban roads

An investigation into the effects of changes in urban traffic characteristics due to rapid urbanisation and the predicted changes in rainfall characteristics due to climate change on the build-up and wash-off of heavy metals was carried out in Gold Coast, Australia. The study sites encompassed three different urban land uses. Nine heavy metals commonly associated with traffic emissions were selected. The results were interpreted using multivariate data analysis and decision making tools, such as principal component analysis (PCA), fuzzy clustering (FC), PROMETHEE and GAIA. Initial analyses established high, low and moderate traffic scenarios as well as low, low to moderate, moderate, high and extreme rainfall scenarios for build-up and wash-off investigations. GAIA analyses established that moderate to high traffic scenarios could affect the build-up while moderate to high rainfall scenarios could affect the wash-off of heavy metals under changed conditions. However, in wash-off, metal concentrations in 1-75µm fraction were found to be independent of the changes to rainfall characteristics. In build-up, high traffic activities in commercial and industrial areas influenced the accumulation of heavy metal concentrations in particulate size range from 75 - >300 µm, whereas metal concentrations in finer size range of <1-75 µm were not affected. As practical implications, solids <1 µm and organic matter from 1 - >300 µm can be targeted for removal of Ni, Cu, Pb, Cd, Cr and Zn from build-up whilst organic matter from <1 - >300 µm can be targeted for removal of Cd, Cr, Pb and Ni from wash-off. Cu and Zn need to be removed as free ions from most fractions in wash-off.

The impact of managers' characteristics on the use of public relations strategy : an exploratory study in Queensland schools

While previous positive and normative studies have focused on the role public relations should play in organisations and the need for management in all organisations to attend to public relations (Cutlip et al., 2006), there has been little discussion in the public relations literature on why or how managers choose to enact public relations strategies for their organisations. If the discipline of public relations is to cement itself as a management function, then researchers must gain a better understanding of managers themselves given that they are the ones who decide if and how public relations strategies should be employed in the organisation. This study has sought to explore evidence of a relationship between management characteristics and their impact on decisions managers make when choosing which public relations strategies to adopt in response to changes in the organisation’s operating environment. This exploratory research study has been conducted within a specific context of schools in Queensland, Australia. Queensland schools have been facing a number of changes within their operating environment due to changes in Federal funding models in Australia’s education system. This study used an exploratory, qualitative approach to understand the management characteristics demonstrated by managers in schools and how these have impacted on the selection of public relations strategies for responding to their changing and increasingly competitive environment. The unit of analysis for this research study was principals in State (government) schools and in non-government schools. Ten principals were interviewed from four different types of schools in Queensland – the more traditional, elite, private schools (GPS Schools); other Independent Schools; Catholic Schools; and State (or public) schools. These interviews were analysed for quantitative comparisons of the managers’ characteristics across the different schools (in terms of the number of principals in each age bracket, those holding postgraduate qualifications, years of experience etc.); and for qualitative data to provide a greater sense of their understanding of public relations. The 10 schools were selected within a geographic area from Brisbane’s inner city to its outer western suburbs to include an element of competition amongst those managers being interviewed. A detailed review of government, school and other public documents was also conducted to gain an insight into the environment in which principals made decisions about public relations strategy to respond to increasing competition. This study found support for the literature on the relationship between management characteristics and strategy. However, there was also variation in findings warranting further investigation of the literature on the relationship between management characteristics and strategy in a school setting. Key relationships found in this study were between: management characteristics themselves; age and the use of public relations strategies; and gender and the use of public relations strategies. There was also evidence of support for the literature linking the impact that the combination of managers’ age, education and experience had on the use of public relations strategies. While this study was exploratory in nature, it did reveal a number of areas that require further investigation to gain a deeper understanding of how and why managers choose public relations strategies as a response to changes in their operating environment. It also provided a different framework to gain a better understanding of managers’ understanding and support of public relations in schools, which, in conjunction with an analysis of their management characteristics, will hopefully allow public relations scholars and practitioners alike gain an understanding of how and why managers use public relations strategies.

Driver distractions: Characteristics underlying drivers' risk perceptions

Driver distraction is a research area that continues to receive considerable research interest but the drivers’ perspective is less well documented. The current research focuses on how drivers perceive the risks associated with a range of driver distractions with the aim of identifying features that contribute to their risk perception judgements. Multidimensional scaling analysis was employed to better understand drivers’ risk perceptions for 15 in-vehicle and external distractions. Results identify both salient qualitative characteristics that underpin drivers’ risk perceptions, such as the probability of a crash, as well as identify other features inherent in the distractions that may also contribute to risk perceptions. The implications of the results are discussed for better understanding drivers’ perceptions of distractions and the potential for improving road safety messages related to distracted driving.

The hydrodynamic and capture/retention performance of a gross pollutant trap

This research shows that gross pollutant traps (GPTs) continue to play an important role in preventing visible street waste—gross pollutants—from contaminating the environment. The demand for these GPTs calls for stringent quality control and this research provides a foundation to rigorously examine the devices. A novel and comprehensive testing approach to examine a dry sump GPT was developed. The GPT is designed with internal screens to capture gross pollutants—organic matter and anthropogenic litter. This device has not been previously investigated. Apart from the review of GPTs and gross pollutant data, the testing approach includes four additional aspects to this research, which are: field work and an historical overview of street waste/stormwater pollution, calibration of equipment, hydrodynamic studies and gross pollutant capture/retention investigations. This work is the first comprehensive investigation of its kind and provides valuable practical information for the current research and any future work pertaining to the operations of GPTs and management of street waste in the urban environment. Gross pollutant traps—including patented and registered designs developed by industry—have specific internal configurations and hydrodynamic separation characteristics which demand individual testing and performance assessments. Stormwater devices are usually evaluated by environmental protection agencies (EPAs), professional bodies and water research centres. In the USA, the American Society of Civil Engineers (ASCE) and the Environmental Water Resource Institute (EWRI) are examples of professional and research organisations actively involved in these evaluation/verification programs. These programs largely rely on field evaluations alone that are limited in scope, mainly for cost and logistical reasons. In Australia, evaluation/verification programs of new devices in the stormwater industry are not well established. The current limitations in the evaluation methodologies of GPTs have been addressed in this research by establishing a new testing approach. This approach uses a combination of physical and theoretical models to examine in detail the hydrodynamic and capture/retention characteristics of the GPT. The physical model consisted of a 50% scale model GPT rig with screen blockages varying from 0 to 100%. This rig was placed in a 20 m flume and various inlet and outflow operating conditions were modelled on observations made during the field monitoring of GPTs. Due to infrequent cleaning, the retaining screens inside the GPTs were often observed to be blocked with organic matter. Blocked screens can radically change the hydrodynamic and gross pollutant capture/retention characteristics of a GPT as shown from this research. This research involved the use of equipment, such as acoustic Doppler velocimeters (ADVs) and dye concentration (Komori) probes, which were deployed for the first time in a dry sump GPT. Hence, it was necessary to rigorously evaluate the capability and performance of these devices, particularly in the case of the custom made Komori probes, about which little was known. The evaluation revealed that the Komori probes have a frequency response of up to 100 Hz —which is dependent upon fluid velocities—and this was adequate to measure the relevant fluctuations of dye introduced into the GPT flow domain. The outcome of this evaluation resulted in establishing methodologies for the hydrodynamic measurements and gross pollutant capture/retention experiments. The hydrodynamic measurements consisted of point-based acoustic Doppler velocimeter (ADV) measurements, flow field particle image velocimetry (PIV) capture, head loss experiments and computational fluid dynamics (CFD) simulation. The gross pollutant capture/retention experiments included the use of anthropogenic litter components, tracer dye and custom modified artificial gross pollutants. Anthropogenic litter was limited to tin cans, bottle caps and plastic bags, while the artificial pollutants consisted of 40 mm spheres with a range of four buoyancies. The hydrodynamic results led to the definition of global and local flow features. The gross pollutant capture/retention results showed that when the internal retaining screens are fully blocked, the capture/retention performance of the GPT rapidly deteriorates. The overall results showed that the GPT will operate efficiently until at least 70% of the screens are blocked, particularly at high flow rates. This important finding indicates that cleaning operations could be more effectively planned when the GPT capture/retention performance deteriorates. At lower flow rates, the capture/retention performance trends were reversed. There is little difference in the poor capture/retention performance between a fully blocked GPT and a partially filled or empty GPT with 100% screen blockages. The results also revealed that the GPT is designed with an efficient high flow bypass system to avoid upstream blockages. The capture/retention performance of the GPT at medium to high inlet flow rates is close to maximum efficiency (100%). With regard to the design appraisal of the GPT, a raised inlet offers a better capture/retention performance, particularly at lower flow rates. Further design appraisals of the GPT are recommended.