21 research outputs found
Energy Consumption and Carbon Emissions of Electric Vehicles Under Real Driving Conditions
This thesis investigates the energy consumption of electric vehicles (EVs) under realworld driving conditions and the associated carbon emissions during charging, which are influenced by electricity grid mix, travel demand and energy consumption. Existing methods of road measurements of EVs used unscheduled trips, making the results particular to the test location and difficult to compare. Besides shifting to EVs, additional actions enable further decarbonisation of road transport resulting from changes in travel demand and charging flexibility. The analysis uses data collected from an EV operated on UK roads for almost four years, and the evaluation of the energy consumption was carried out following a real driving cycle (RDC) schedule. The results show EV specific energy consumption (SEC) is highly influenced by changes in ambient temperature, nearly doubling from operation at moderate temperatures of around 20°C to operation at temperatures as low as 0°C due to the corresponding loads required by heating and air conditioning systems. Short trips below 16 km caused nearly 10% SEC average increase in comparison with longer ones, showing more awkward effects in motorway operation with SEC rise up to 29%. Traffic conditions and driving behaviour also demonstrated a high influence on SEC, increasing it by 40% and 16%, respectively, from the most favourable to the most unfavourable condition. A model was developed to investigate carbon emissions projections of passenger vehicles considering the expected large EV market penetration and the impact of changes in road traffic using a set of scenarios based on vehicle ownership and usage. A reduction of 22% in EVs cumulative carbon emissions by 2050 can be achieved by targeting 23% lower vehicle number and 17% usage, while an opposite scenario increases EV cumulative carbon emissions by 28%. The regional differences in energy consumption and carbon emissions were modelled under different charging scenarios, showing carbon emission reduction varies from 4% to 33% between the regions when switching to delayed charging, shifting the charging outside peak hours. An optimised charging that moves charging events to periods of low grid carbon intensity reduces carbon emissions from 6% to 55%, affected by region grid carbon intensity and energy consumption
Cross-language information seeking behaviour English Vs Arabic
Purpose
– The purpose of this paper is to report the results and the methods of a study which applied grounded theory to the information-seeking behaviour of social scientists when searching Arabic and English academic databases using both languages.
Design/methodology/approach
– The research applied the grounded theory approach using search experiments and semi-structured interviews. Think-aloud protocol during the experiment was used to capture the data from the subjects to allow a detailed analysis for the experiment. The semi-structured interviews followed each experiment and were analysed using the Strauss and Corbin (1990) version of the grounded theory, as were the think-aloud protocols.
Findings
– The results of the think-aloud protocols and the semi-structured interviews suggest that the information needs of the subjects varied depending on the language used. In addition, it was discovered that social scientists followed more tactics in searching the Arabic database for the same tasks searched in English during the experiment. This allowed more search strategies and search tactics to appear in seeking information in Arabic language. The study also proposed a model to account for the cross-language information-seeking behaviour.
Research limitations/implications
– This study identifies and compares the information-seeking behaviour of the social scientists in Jordanian universities in searching both Arabic and English academic databases. Therefore, the findings of this study cannot be generalized to other Arab countries, unless there was similar context.
Originality/value
– Few studies have investigated information-seeking behaviour using academic Arabic databases and proposed information-seeking behaviour models. No studies have compared information-seeking behaviour when using Arabic and English academic databases. The value of the current study arises by being the first study to identify and compare the information-seeking behaviour of social scientists by using grounded theory and proposing a cross-language information-seeking behaviour model.
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Regional Electric Vehicle Energy Consumption and Carbon Emissions in Great Britain
This work presents the regional differences in electric vehicle (EV) real-world energy consumption and associated carbon emissions during charging in Great Britain (GB). A model was developed considering the variability in road traffic, ambient temperature, and electricity grid profile between the GB regions on EV carbon emissions under uncontrolled and smart scenarios. The results show the variations in EV energy consumption and carbon emissions impacted by where, when, and how an EV is driven and charged. Carbon emission reduction varies from 5% to 33% between the regions when switching to delayed smart charging, shifting the charging process outside peak hours. An optimised smart charging that moves the charging events to periods of low grid carbon intensity reduces carbon emissions from 6% to 55%, affected by region grid carbon intensity and energy consumption
COMMUNICATION ABILITIES OF JORDANIAN INDIVIDUALS WITH CEREBRAL PALSY ACCORDING TO TYPE, AGE, AND MENTAL ABILITIES
ABSTRACT Objectives: To identify the speech characteristics of various types of Jordanian cerebral palsied children and young adults, and to relate them to age, the associated dysarthria, and cognitive level. Methods: The medical records of 248 cerebral palsied children and young adults seen at the Royal Rehabilitation Center, between 1990 and 2005, were reviewed and analyzed retrospectively. The type, oral motor abilities, Intelligence Quotient, and other disabilities were identified for each case. The speech and language assessment results were categorized into normal, moderate disability, or severe disability. Findings were analyzed with regression analysis and Pearson's correlation using SPSS 10. Results: No statistically significant differences were found in the speech characteristics between the four main types of cerebral palsy. However, strong correlations were found between speech proficiency and both oral-motor abilities and Intelligence Quotient level, and, to a lesser degree, with the age group. Conclusion: The results of this study showed that speech characteristics of Jordanian cerebral palsied cases are not different from those reported in the literature for other languages
Countering Identity Theft and Strengthening Data Security Practices Across the Tax Preparer Community
Techno-economic planning of a fully renewable energy-based autonomous microgrid with both single and hybrid energy storage systems
This paper presents both the techno-economic planning and a comprehensive sensitivity analysis of an off-grid fully renewable energy-based microgrid (MG) intended to be used as an electric vehicle (EV) charging station. Different possible plans are compared using technical, economic, and techno-economic characteristics for different numbers of wind turbines and solar panels, and both single and hybrid energy storage systems (ESSs) composed of new Li-ion, second-life Li-ion, and new lead–acid batteries. A modified cost of energy (MCOE) index including EVs’ unmet energy penalties and present values of ESSs is proposed, which can combine both important technical and economic criteria together to enable a techno-economic decision to be made. Bi-objective and multi-objective decision-making are provided using the MCOE, total met load, and total costs in which different plans are introduced as the best plans from different aspects. The number of wind turbines and solar panels required for the case study is obtained with respect to the ESS capacity using weather data and assuming EV demand according to the EV population data, which can be generalized to other case studies according to the presented modelling. Through studies on hybrid-ESS-supported MGs, the impact of two different global energy management systems (EMSs) on techno-economic characteristics is investigated, including a power-sharing-based and a priority-based EMS. Single Li-ion battery ESSs in both forms, new and second-life, show the best plans according to the MCOE and total met load; however, the second-life Li-ion shows lower total costs. The hybrid ESSs of both the new and second-life Li-ion battery ESSs show the advantages of both the new and second-life types, i.e., deeper depths of discharge and cheaper plans
A THREE PART ESSAY ON THE ROLE OF GOVERNMENT SUBSIDIES ON FIRM LEVEL INNOVATIVE CAPACITY A SYNTHESIS OF EFFECT, PRODUCTIVITY AND PROFITABILITY.
Our analysis contains three essay that look to the effect of innovations given a diverse set of measures. The purpose of the first chapter, which is divided into two levels, is two-fold. First, via a Probit model, we assess the effect subsidies have on firm level innovation and determine if these effects impound in firm level performance given these subsidies. Second, we seek to determine the extent subsidies promote learning and hence positively impact outcomes associated with innovation. We do so by employing the theory of absorptive capacity to guide efforts to isolate the effects that the combination or interaction of investments in research and development and foreign technology have on firm level performance. We adopt Ordinary Least Squares in this endeavor. In the second chapter, we measure, evaluate, and assess whether external infrastructures allow firms to exploit their resources in order to gain maximum efficiency and effectiveness. In this regard, we review the impact infrastructures have on the capacity of a firm to innovate when those infrastructures are viewed as key to the operations of a firm. In doing so, our goal is to assess the impact of these infrastructures components on firm performance. We do so through a Probt model. The purpose of third chapter is to determine the role innovation has in firm performance. Our approach, in essence, seeks to assess the role innovation and subsidies, individually and collectively, have on firm performance. Our study makes use of ordinary least squares regression to investigate this query
Effects of ambient temperature and trip characteristics on the energy consumption of an electric vehicle
This work evaluates the impacts of ambient temperature and trip characteristics on the energy consumption of an electric vehicle (EV) during road tests. The trip characteristics are here defined by the driving distance, stop time percentage and average vehicle speed. The analysis uses data collected from real-world driving of an EV in one of the most populous metropolitan regions in the UK for almost four years, using a dedicated monitoring software for real-time vehicle data processing. The results reveal that the EV specific energy consumption (SEC) increases under operation at low temperature, also showing a larger scatter. Significant changes in SEC are linked to auxiliary energy demand and trip characteristics, especially under cold temperatures. Trips complying with a real-world driving test procedure produced lower SEC than random trips at cold temperatures but showed closed values at moderate temperatures. At both cold and moderate temperature conditions the EV presented lower SEC for urban driving, in comparison with rural and motorway operation, confirming its adequacy for application in metropolitan areas. Urban EV operation at low temperatures from 0°C to 15°C has a trip range 28% lower than driving at moderate temperatures from 15°C to 25°C