1,231 research outputs found
Electric Vehicles Lithium-Polymer Ion Battery Dynamic Behaviour Charging Identification and Modelling Scheme
Lithium-ion batteries are considered the substantial electrical storage element for electric vehicles (EVs). The battery model is the basis of battery monitoring, efficient charging, and safety management. Non-linear modelling is the key to representing the battery and its dynamic internal parameters and performance. This paper proposes a smart scheme to model the lithium-polymer ion battery while monitoring its present charging current and terminal voltage at various ambient conditions (temperature and relative humidity). Firstly, the suggested framework investigated the impact of temperature and relative humidity on the charging process using the constant current-constant voltage (CC-CV) charging protocol. This will be followed by monitoring the battery at the surrounding operating temperature and relative humidity. Hence, efficient non-linear modelling of the EV battery dynamic behaviour using the Hammerstein-Wiener (H-W) model is implemented. The H-W model is considered a black box model that can represent the battery without any mathematical equivalent circuit model which reduces the computation complexity. Finally, the model beholds the boundaries of the charging process that not affecting on the lifetime of the battery. Several dynamic models are applied and tested experimentally to ensure the effectiveness of the proposed scheme under various ambient conditions where the temperature is fixed at 40°C and the relative humidity (RH) at 35%, 52%, and 70%. The best fit using the H-W model reached 91.83% to describe the dynamic behaviour of the battery with a maximum percentage of error 0.1V which is in good agreement with the literature survey. Besides, the model has been scaled up to represent a real EV and expressed the significance of the proposed H-W model
The Application of Human-Centric Lighting in Response to Working from Home Post-COVID-19
COVID-19 has caused a considerable proportion of the public to work from home, either part- or full-time, in unregulated domestic conditions, which have not been designed for commercial activities. This study determined what existing lighting conditions were present in a selection of work-from-home (WFH) environments (Objective One) through quantitative lux level and equivalent melanopic lux (EML) readings by evaluating them against regulatory standards, where further study is required to validate the results with a larger dataset. This study also investigated the social demand for human-centric lighting (HCL) installations within WFH environments (Objective Two) through qualitative questionnaires by considering key parameters: sustainability, practicality, and cost. The results of Objective One showed that compliance with general safety lighting requirements was achieved by 80% of the installations. The mean lux level recorded was 452.4 lux and 0.729 uniformity, which fell below commercial requirements defined for commonly performed WFH activities; 34.3% of recorded EML dropped below the regulatory requirements under daylight conditions. When isolated to artificial lighting, only 7.5% of the required EML was achieved. The results of Objective Two showed that generally participants did not feel that their WFH installations were unsuitably lit, however, 46.2% of participants identified noticeable headaches or eye strain when working from home. A total of 80% of participants highlighted that HCL task lighting would be preferable. It was also found that participants were willing to invest in circadian lighting for health, where 63.2% of them would not accept a reduction in efficiency of over 10% compared to non HCL. Wellbeing was found to be participants’ key preference for their lighting systems, followed by efficiency, home impact, and cost
An Improved Algorithm to Solve Transportation Problems for Optimal Solution
In this paper, we have developed an algorithm to obtain initial basic feasible solution of transportation problems where the object is to minimize the transportation cost. The proposed method is compared with well-known existing methods including Least-Cost Method and North-West Corner Method and is found to yield better results. Feasible solution from the proposed method leads to solution closest to the optimal solution; and in some numerical examples same as the optimal solution. Key words: Transportation problem, Initial Basic Feasible Solution, Optimal Solutio
Recommended from our members
Android application collusion demystified
Application collusion is an emerging threat to Android based devices. In app collusion, two or more apps collude in some manner to perform a malicious action that they are unable to do independently. Detection of colluding apps is a challenging task. Existing commercial malware detection systems analyse each app separately, hence fail to detect any joint malicious action performed by multiple apps through collusion. In this paper, we discuss the current state of research on app collusion and open challenges to the detection of colluding apps. We compare existing approaches and present an integrated approach to effectively detect app collusion
A facile synthesis of porous graphene for efficient water and wastewater treatment
This is the final version of the article. Available from Springer Nature via the DOI in this record.The use of two-dimensional graphene-based materials in water treatment has recently gained significant attention due to their unique electronic and thermal mobility, high surface area, high mechanical strength, excellent corrosion resistance and tunable surface chemistry. However, the relatively expensive, poor hydrophobicity, low adsorption capacity and recyclability, and complex post-treatment of the most pristine graphene frameworks limit their practical application. Here, we report a facile scalable method to produce highly porous graphene from reduced graphene oxide via thermal treatment without addition of any catalyst or use of any template. Comparing to conventional graphene counterparts, as-prepared porous graphene nanosheets showed evident improvement in hydrophobicity, adsorption capacity, and recyclability, making them ideal candidate materials for water treatment. Superhydrophobic and superoleophilic porous graphene prepared in this work has been demonstrated as effective absorbents for a broad range of ions, oils and organic solvents, exhibiting high selectivity, good recyclability, and excellent absorption capacities > 90%. The synthesis method of porous graphene reported in this paper is easy to implement, low cost and scalable. These attributes could contribute towards efficient and cost-effective water purification and pollution reduction.The authors acknowledge support from the EPSRC Centre for Doctoral Training in Metamaterials at the University of Exeter [Grant no. EP/L015331/1]
Evaluation of externality management instruments in marine fisheries
New Zealand marine fishing activities create many types of environmental externalities,
which by law must be internalised. Selection of best intemalisation instruments can be aided
by following a hierarchical decision process, which first screens the universe of instruments
against implementation criteria to establish the feasible set. Instruments in the feasible set
can be evaluated against a range of environmental, Treaty ofWaitangi, economic, sociocultural
and management criteria. This approach to selection can be formalised in decision
support software to provide a useful tool for fisheries management agencies
Criteria to evaluate the application of policy instruments designed to internalise externalities from commercial fisheries : report to Ministry of Fisheries
New Zealand has the world's fourth largest Exclusive Economic Zone and a very large commercial fishery. Arguably this fishery is one of the best managed in the world. Nevertheless, many problems remain to be solved, especially environmental problems. Many of these problems can be categorised as externalities from commercial fishing. We (Hughey et al. 2000) have identified a wide range of policy instruments which can be applied to the internalisation of these externalities. In this report we identify criteria against which each of these instruments should be evaluated before it is considered for implementation. The criteria are environmental, Treaty of Waitangi, socio-economic, recreational and management, respectively. We then evaluate the effectiveness of chosen instruments against these criteria.
All of these tools can be used to enhance decision making in fisheries management and a framework for this decision making is proposed
Effect of Cavity Vacuum Pressure Diminution on Thermal Performance of Triple Vacuum Glazing
Long-term durability of the vacuum edge-seal plays a significant part in retrofitting triple vacuum glazing (TVG) to existing buildings in achieving towards zero-energy buildings (ZEB) target. Vacuum pressure decrement with respect to time between panes affect the thermal efficiency of TVG. This study reports a 3D finite element model, with validated mathematical methods and comparison, for the assessment of the influence of vacuum pressure diminution on the thermal transmittance (U value) of TVG. The centre-of-pane and total U values of TVG calculated to be 0.28 Wm−2K−1 and 0.94 Wm−2K−1 at the cavity vacuum pressure of 0.001 Pa. The results suggests that a rise in cavity pressure from 0.001 Pa to 100 kPa increases the centre-of-pane and total U values from 0.28 Wm−2K−1 and 0.94 Wm−2K−1 to 2.4 Wm−2K−1 and 2.58 Wm−2K−1, respectively. The temperature descent on the surfaces of TVG between hot and cold sides’ increases by decreasing the cavity vacuum pressure from 50 kPa to 0.001 Pa. To maintain the cavity vacuum pressure of 0.001 Pa for over 20 years of life span in the cavity of 10 mm wide edge sealed triple vacuum glazing, non-evaporable getters will maintain the cavity vacuum pressure that will enable the long-term durability to TVG
Rural water collection patterns: combining smart meter data with user experiences in Tanzania (article)
This is the final version. Available on open access from MDPI via the DOI in this recordThe dataset associated with this article is available in ORE at: https://doi.org/10.24378/exe.2283Water collection from piped water distribution systems (PWSs) in rural communities in
sub-Saharan Africa is not understood in much detail. Here, distances travelled to distribution
points (DPs), volumes collected, times of day of collection, and the relationship between location of
DP and volume dispensed are investigated in a rural community in Tanzania using a combination
of novel smart pre-payment meters and results from surveys and interviews. Continuous
availability of water through pre-payment smart meters is shown to eliminate queue time, freeing
time for farming or schooling, and enhance revenue collection for service provision. 97% of users
use DPs as a main source of drinking water as opposed to unimproved alternative sources, and
42% live further than 400 meters from a DP. Collection occurs across daylight with greater volumes
dispensed in the afternoon-evening due to free time from economic activities and children
returning from school. A low mean daily collection of 47 litres per household from DPs is
measured. Volume dispensed across different DPs over time shows no clear pattern. However, the
volume dispensed is indicated by the number of households that use each DP. Increasing PWS
capacity can accommodate for variable collection patterns, and help improve sustainability of rural
water supply.Africa Water EnterprisesEngineering and Physical Sciences Research Council (EPSRC
- …