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

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

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

Spatial distribution of mortality in Pacific oysters Crassostrea gigas: reflection on mechanisms of OsHV-1 transmission

The ostreid herpesvirus (OsHV-1) has the potential to devastate Crassostrea gigas culture in Australia as it has done in many other countries, highlighting the need for a better understanding of disease expression and transmission. The aim of this study was to assess the spatial distribution of OsHV-1 associated mortalities in one of only two infected areas in Australia, Woolooware Bay (Botany Bay New South Wales). In October 2011, healthy sentinel Pacific oysters were placed in three different locations at three different tidal levels and OsHV-1 associated mortalities were closely monitored over 7 months. The outbreak started in November 2011 and the disease remained active until April 2012. Three major mortality events were detected. Rather than being a propagating epizootic, it appeared that most oysters were infected from the same environmental source. The distribution of OsHV-1 associated mortalities was spatially clustered, highly variable and clearly dependent on the age of oysters and their position in the water column. Non-random distribution of mortalities at macro scale (sites several km apart) and micro scale (within rearing trays), and vertical clustering patterns in the water column are discussed in relation to mechanisms of transmission in water. We hypothesise that OsHV-1 may be carried through water by particles, possibly plankton. Key words: Crassostrea gigas, Ostreid herpesvirus 1, summer mortalities, spatial distribution, plankton, disease transmissionFunded by the Fisheries Research and Development Corporation, the University of Sydney and the Sydney Metropolitan Catchment Management Authorit

Experimental infections of Pacific oyster Crassostrea gigas using the Australian OsHV-1 µVar strain

In Australia the spread of the Ostreid herpesvirus OsHV-1 microvariant (OsHV-1 µVar) threatens the Pacific oyster industry. There was an urgent need to develop an experimental infection model in order to study the pathogenesis of the virus in controlled laboratory conditions. The present study constitutes the first attempt to use archived frozen oysters as a source of inoculum, based on the Australian OsHV-1 µVar strain. Experiments were conducted to test (i) the virus infectivity, (ii) the dose-response relationship for OsHV-1, and (iii) the best storage conditions to keep infective viral inoculum. Intramuscular injection of a viral inoculum consistently led to an onset of mortality 48h post injection and a final cumulative mortality exceeding 90%, in association with high viral loads (1 x 105 – 3 x 107 copies of virus mg-1) in dead individuals. For the first time an infective inoculum was produced from frozen oysters (tissues stored at -80°C for 6 months). Storage of purified viral inoculum at +4°C for 3 months provided similar results to use of fresh inoculum whereas storage at -20°C, -80°C and room temperature was detrimental to infectivity. A dose-response relationship for OsHV-1 was identified but further research is recommended to determine the most appropriate viral concentration for development of infection models that would be used for different purposes. Overall, this work highlights the best practices and potential issues that may occur in the development of a reproducible and transferable infection model for studying the pathogenicity of the Australian OsHV-1 strain in C. gigas under experimental conditions. Keywords: Ostreid herpesvirus 1; Crassostrea gigas; experimental infection model; dose-response; inoculum preparation; storage condition

Attachment accuracy of a novel prototype robotic rotary and investigation of two management strategies for incomplete milked quarters

Throughout 2009 and 2010, FutureDairy (Camden, NSW, Australia) was involved in testing a novel prototype robotic rotary (RR). The commercial version RR is expected to be capable of carrying out 90 milkings per hour. To achieve the high throughput the rotary rotates the cow to the cup attachment robot and then around the platform in a stop–start fashion. The robot does not remain with the cow during the entire milking process. When not all teat cups are attached during a milking session there is an opportunity for cows to be sent back to the waiting yard for a second milking attempt. The study presented here was designed to test whether or not the extension of the interval to a second milking attempt improved milking success of incompletely milked cows. It was expected that with an increased milking interval between the two subsequent milkings the changes to the udder conformation could positively affect the attachment success at the second attempt. The 1 h milking interval treatment (1 h) simulated cows being drafted directly back to the pre-milking waiting yard, whilst the 3 h milking interval treatment (3 h) was designed to simulate cows being drafted back after accessing post-milking supplementary feed on a feedpad. The results presented in this manuscript showed no significant difference between the frequencies of successful attachment in the second attempt between the 1 h and 3 h treatments indicating that a reasonable level of flexibility exists with management of incompletely milked cows and dairy layout designs. Milk production level affected the probability of success at second attempt, which was about 7.5 times higher in cows with an average milk production level greater than 19.3 kg than those with less than 10.8 kg. When looking at the total proportion of cows successfully milked after two attempts, it was found that successful milking was more likely in multiparous cows compared to primiparous cows. Highlights • We studied management options for incompletely milked cows on a robotic rotary. • Firstly cows returned to waiting yard with approx. 1 h interval between attempts. • Secondly cows returned to waiting yard via feed pad – approx. 3 h between attempts. • No difference found between 1 and 3 h intervals on attachment success. • Level of flexibility exists with management of incompletely milked cows. Keywords: Success-rate; Pasture based; Automatic milking system; Robotic rotary; DairyDairy Australia, DeLaval, Department of Primary Industries NSW and The University of Sydney

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

Why is temperature sensitivity important for the success of common respiratory viruses?

This review explores the idea that temperature sensitivity is an important factor in determining the success of respiratory viruses as human parasites. The review discusses several questions. What is viral temperature sensitivity? At what range of temperatures are common respiratory viruses sensitive? What is the mechanism for their temperature sensitivity? What is the range of temperature along the human airway? What is it that makes respiratory viruses such successful parasites of the human airway? What is the role of temperature sensitivity in respiratory zoonoses? A definition of temperature sensitivity is proposed, as “the property of a virus to replicate poorly or not at all, at the normal body temperature of the host (restrictive temperature), but to replicate well at the lower temperatures found in the upper airway of the host (permissive temperature).” Temperature sensitivity may influence the success of a respiratory virus in several ways. Firstly; by restricting the infection to the upper airways and reducing the chance of systemic infection that may reduce host mobility and increase mortality, and thus limit the spread of the virus. Secondly; by causing a mild upper airway illness with a limited immune response compared to systemic infection, which means that persistent herd immunity does not develop to the same extent as with systemic infections, and re‐infection may occur later. Thirdly; infection of the upper airway triggers local reflex rhinorrhea, coughing and sneezing which aid the exit of the virus from the host and the spread of infection in the community

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/