Characterization of Flywheel Energy Storage System for Hybrid Vehicles

Flywheels are excellent secondary energy storage devices and several applications in road vehicles are under development. They can be used in hybrid vehicles with an internal combustion engine (ICE) as the prime mover or can be used in hybrid energy storage (HES) to complement the battery. When used in HES, they are utilized to load level the battery so as to protect it from peak loads and enhance its capacity and life. This paper deals with defining the main characteristics of the flywheel for an application as a secondary energy storage device for an electric vehicle. Various strategies for defining flywheels are explained. A real world customer usage data is also presented. This data is analyzed and its results are used to support the selection of the flywheel characteristics. The results show that the chosen flywheel is sufficiently sized to perform its intended tasks for a c-segment passenger car electric vehicle

Analysis of Dual Mode Continuously Variable Transmission for Flywheel Energy Storage Systems

There are different types of energy storage devices which are used in today’s hybrid and electric vehicles. Batteries, ultra capacitors and high speed flywheels are the most commonly used ones. While batteries and supercapacitors store energy in the form of electric energy, the flywheel (FW) is the only device that keeps the energy stored in the original form of mechanical energy the same as the moving vehicle. The flywheel needs to be coupled to the driveshaft of the vehicle in a manner which allows it to vary its speed independently of the moving vehicle in order to vary its energy content. In other words a continuously variable transmission (CVT) is needed. The common mechanical variators used in automotive applications, namely the rolling traction drives and the belt drives, have the disadvantage that their speed ratio range defined as the maximum to minimum speed ratio is generally not sufficient for flywheel energy storage system (FESS). One of the ways to improve the ratio range is by using a dual mode transmission, where the ratio coverage of the variator is exploited twice. This paper presents the fundamental kinematics of such a transmission including its variants. The equations of speed ratio, power flow and efficiency are derived for a variator only transmission and a power split CVT (PSCVT) used in dual mode and the results compared

Simulation based study of battery electric vehicle performance in real world cycles

The development of battery electric vehicles (BEV) must continue since this offers the leading route towards a zero emission transport system. The fuel flexibility of the BEV offers the greatest potential to utilize power from renewable or low emission sources to be used in the transport system. However the limited range and high cost of the BEV remain important issues to be addressed. The battery is the element which strongly affects the cost and range of the BEV. The batteries offer either high specific power or high specific energy, but not both. This paper presents the modelling of a BEV which is used to study the potential for improvement in its energy efficiency. The battery model types have been discussed. The vehicle and other component models have been described. The choice of model parameters and the control strategy has been explained. The simulations have been performed on homologation and real world cycles for different scenarios. Results show significant potential for improvement in the energy efficiency of the BEV in real world usage by the utilization of a secondary energy storage device

Academic cross-pollination: The role of disciplinary affiliation in research collaboration

Academic collaboration is critical to knowledge production, especially as teams dominate scientific endeavors. Typical predictors of collaboration include individual characteristics such as academic rank or institution, and network characteristics such as a central position in a publication network. The role of disciplinary affiliation in the initiation of an academic collaboration between two investigators deserves more attention. Here, we examine the influence of disciplinary patterns on collaboration formation with control of known predictors using an inferential network model. The study group included all researchers in the Institute of Clinical and Translational Sciences (ICTS) at Washington University in St. Louis. Longitudinal data were collected on co-authorships in grants and publications before and after ICTS establishment. Exponential-family random graph models were used to build the network models. The results show that disciplinary affiliation independently predicted collaboration in grant and publication networks, particularly in the later years. Overall collaboration increased in the post-ICTS networks, with cross-discipline ties occurring more often than within-discipline ties in grants, but not publications. This research may inform better evaluation models of university-based collaboration, and offer a roadmap to improve cross-disciplinary collaboration with discipline-informed network interventions

The use of a modified Delphi approach to engage stakeholders in zoonotic disease research priority setting

Background After the 2011 cluster of Hendra virus cases in horses in Australia, public health targeted education initiatives at people in the equine industry to reduce human exposure to potentially infected horses. ‘Horse owners and Hendra Virus: A Longitudinal cohort study To Evaluate Risk’ aims to enhance public health measures through improved understanding of Hendra virus risk perception and risk mitigation strategies among horse owners and horse care providers. This paper describes the stakeholder consultation that was undertaken to ensure the cohort study outcomes were relevant to diverse groups who play a role in Hendra virus policy development and implementation. Methods A two-round modified Delphi study with online questionnaires was conducted. In round one, stakeholders identified priority research areas. In round two, stakeholders rated and ranked topics that emerged from thematic analysis of the round one responses. Round two data were analysed using logistic regression. Results Of the 255 stakeholders contacted, 101 responded to round one. Over 450 topics were proposed. These were organized into 18 themes. Approximately two thirds of the round one respondents participated in round two. ‘Hendra virus-related risk awareness and perception’, ‘personal health and safety’, ‘emergency preparedness’, ‘risk prevention, mitigation, and biosecurity’, and ‘Hendra virus vaccination in horses – attitudes/uptake’ were the top five areas identified according to probability of being ranked extremely important. Conclusions In this study, a modified Delphi approach was effective in guiding research into Hendra virus, a zoonotic disease of animal and human health significance. The findings support the notion that stakeholders should be engaged in zoonotic disease research priority setting. Such consultation will help to ensure that research initiatives are relevant and useful to stakeholders in the position to make use of new findings. Keywords Delphi method Stakeholder engagement Zoonotic disease Hendra virus Public health Thematic analysisThis research was funded by the Commonwealth of Australia, the State of New South Wales and the State of Queensland under the National Hendra Virus Research Program

Effect of age and surgical approach on perioperative wound complication following ovariohysterectomy in shelter-housed cats in Australia

Objectives The aim of the study was to investigate the effects of age and/or surgical approach on perioperative wound complication following ovariohysterectomy (OHE). Methods A retrospective search of perioperative monitoring records from a shelter desexing program was conducted to identify cats that underwent OHE between 1 June 2010 and 31 December 2012 inclusive. A wound complication was defined as gross observation of inflammation or wound dehiscence at the surgical site in the 5 day postoperative period. Cases were grouped according to age (≤12 weeks or >12 weeks) and surgical approach (flank or midline). Stratified analyses were conducted to evaluate the association between surgical approach and wound complications, after adjusting for age. Mantel–Haenszel adjusted risk ratio, Cochran–Mantel–Haenszel test statistic and their 95% confidence intervals were presented. Results A total of 312 cases met the study criteria. The overall wound complication risk was low (6.09%) and was not related to age. A midline approach was associated with a 4.59-times increased risk of wound complication, compared with a flank approach in cats up to 12 weeks of age (P = 0.015) but not in older cats. Conclusions and relevance These findings support the practice of prepubertal desexing for cats.n/

Inhalation Therapy in Patients Receiving Mechanical Ventilation: An Update

Incremental gains in understanding the influence of various factors on aerosol delivery in concert with technological advancements over the past 2 decades have fueled an ever burgeoning literature on aerosol therapy during mechanical ventilation. In-line use of pressurized metered-dose inhalers (pMDIs) and nebulizers is influenced by a host of factors, some of which are unique to ventilator-supported patients. This article reviews the impact of various factors on aerosol delivery with pMDIs and nebulizers, and elucidates the correlation between in-vitro estimates and in-vivo measurement of aerosol deposition in the lung. Aerosolized bronchodilator therapy with pMDIs and nebulizers is commonly employed in intensive care units (ICUs), and bronchodilators are among the most frequently used therapies in mechanically ventilated patients. The use of inhaled bronchodilators is not restricted to mechanically ventilated patients with chronic obstructive pulmonary disease (COPD) and asthma, as they are routinely employed in other ventilator-dependent patients without confirmed airflow obstruction. The efficacy and safety of bronchodilator therapy has generated a great deal of interest in employing other inhaled therapies, such as surfactant, antibiotics, prostacyclins, diuretics, anticoagulants and mucoactive agents, among others, in attempts to improve outcomes in critically ill ICU patients receiving mechanical ventilation

Comparison of pre- and post-vaccination ovine Johne's disease prevalence using a Bayesian approach

This study was conducted to evaluate the effectiveness of GudairTM vaccine in decreasing the prevalence of shedding of Mycobacterium avium subsp. paratuberculosis (MAP) in flocks of varying initial prevalence. Thirty seven self-replacing Merino flocks from New South Wales and Victoria (Australia) that had been vaccinating lambs with GudairTM for at least five years were enrolled in the study. These flocks had been tested prior to or at commencement of vaccination using pooled faecal culture, agar gel immunodiffusion or both tests. These pre-vaccination test results were used to estimate pre-vaccination prevalence. Post-vaccination prevalence was estimated from culture of usually 7 pools of 50 sheep collected from the enrolled flocks in 2008-2009, approximately five or more years after commencement of vaccination. A Bayesian model was developed to estimate and compare the pre- and post-vaccination prevalences for the enrolled flocks. Apparent pre- and post-vaccination prevalences for flocks were modelled as functions of the true pre- and post-vaccination prevalences, respectively, and the sensitivities and specificities of the respective diagnostic tests. Logit-normal models were specified on pre- and post-vaccination true prevalences and were then used to make inferences about the median and 90th percentile of the prevalence distributions and their differences. Priors were mostly specified based on published literature or analysis of abattoir surveillance data for this population of flocks. The analysis found a significant decline in ovine Johne’s disease prevalence from a pre-vaccination median prevalence of 2.72% [95% probability interval (PI): 1.40; 6.86%] to a post-vaccination median prevalence of 0.72% (0.39; 1.27%). However 30 of the 37 flocks still contained sheep that were shedding MAP in their faeces. The results suggest that vaccination with Gudair™ is usually effective in reducing the prevalence of faecal shedding but the response to vaccination is variable among flocks. This approach could be implemented in similar situations to compare prevalences where information from multiple diagnostic tests with varied sensitivities and specificities is available. Keywords: Ovine Johne’s disease; Gudair; Vaccination; Abattoir surveillance; Faecal culture; Agar gel immune-diffusion test