title: Active Electromagnetic Damping for Lightweight Electric Vehicles.

authors: Duke, Mike

subjects: Electromagnetic

abstract: Due to the low weight of most current electric vehicles, the effectiveness of commercial passive dampers is reduced when compared to current production automobiles. Active dampers allow for a significant reduction in the amount of road signal that affects the passenger body. However current active hydraulic dampers tend to be heavy and to have a power consumption that precludes their use in electric vehicles. By use of a linear electromagnetic element it is possible to create an active damper that has enough authority to provide active damping with a fraction of the weight and power consumption of a hydraulic system. A computer model of an active electromagnetic damper was constructed and the results were compared to a physical prototype. This verified the effectiveness of the damper and the low power consumption. This computer model was then scaled up for the simulation of a real world quarter car model. This simulation demonstrated that the use of the active linear electromagnetic damper was more effective at all frequencies when compared to an ideal passive damper. It was also demonstrated that the active electromagnetic damper had a similar mass to a passive damper and had a power consumption of more than an order of magnitude less than a comparable active hydraulic damper. Keywords-component; Electromagnetic; damping; active; suspension.

text: Active Electromagnetic Damping for Lightweight Electric Vehicles. Due to the low weight of most current electric vehicles, the effectiveness of commercial passive dampers is reduced when compared to current production automobiles. Active dampers allow for a significant reduction in the amount of road signal that affects the passenger body. However current active hydraulic dampers tend to be heavy and to have a power consumption that precludes their use in electric vehicles. By use of a linear electromagnetic element it is possible to create an active damper that has enough authority to provide active damping with a fraction of the weight and power consumption of a hydraulic system. A computer model of an active electromagnetic damper was constructed and the results were compared to a physical prototype. This verified the effectiveness of the damper and the low power consumption. This computer model was then scaled up for the simulation of a real world quarter car model. This simulation demonstrated that the use of the active linear electromagnetic damper was more effective at all frequencies when compared to an ideal passive damper. It was also demonstrated that the active electromagnetic damper had a similar mass to a passive damper and had a power consumption of more than an order of magnitude less than a comparable active hydraulic damper. Keywords-component; Electromagnetic; damping; active; suspension.

year: 2015-01-17

title: Biology of common bully (Gobiomorphus cotidianus) populations in the Tarawera and Rangitaiki Rivers: Reproductive isolation by inland distance or effluent discharges?

authors: Bleackley, Natalie Anne

subjects: Gobiomorphus cotidianus

abstract: Previous research identified distinct genetic, life-history and reproductive differences between populations of common bully (Gobiomorphus cotidianus) upstream and downstream of a pulp and paper mill outfall on the Tarawera River in the Bay of Plenty, New Zealand. This thesis sought to investigate the distribution of amphidromous and non-amphidromous common bully in the Tarawera River by examining fish collected from upstream (37 km inland) and downstream (20 km inland) locations and comparing them to fish from similar inland locations (40 km and 17 km inland, respectively) in the nearby Rangitaiki River. Otolith microchemistry revealed life-history differences between upstream and downstream populations and stable isotope analysis ensured long-term site residency. Amphidromy dominated in the downstream river populations, while the disappearance of diadromous fish generally occurred with inland distance. A mixture of diadromous and non-diadromous fish were found in the upstream Rangitaiki, while a complete absence of diadromous recruits was found in the upstream Tarawera River. A reduction in oculoscapular canal structures also coincided with loss of diadromy in fish from both rivers. Temporal reproductive divergence was investigated through track annual trends in gonadosomatic index.

The Tarawera River receives significant inputs from numerous industrial, municipal and natural sources, most notably from two pulp and paper mills. In the absence physical barriers in the Tarawera, it has been hypothesised that the lack of diadromous recruits in the upstream Tarawera River may be related to aquatic discharges in the downstream river. A behavioural study was performed to examine the hypothesis that pulp and paper mill effluent may be acting as a chemical barrier to fish migration within the river. A dual-choice chamber was employed to examine the responses of common bully exposed to a range of effluent concentrations (100, 50, 25, 12.5, 0% v/v). Fish exhibited significant avoidance responses when exposed to 100 and 50% effluent concentration, while no avoidance was observed at effluent concentrations below 50% This study demonstrated that common bully show a strong preference for river water when simultaneously exposed to effluent, albeit at environmentally unrealistic concentrations (i.e. greater than 15%), implicating potential for this effluent to act as a chemical barrier in the Tarawera River.
Following the establishment of reproductive timing of common bully in the Tarawera River, a wild fish health assessment was undertaken to investigate the effects of long-term effluent exposure in situ. Adult common bully were sampled downstream of the mill influence and compared to an appropriate reference population from the downstream Rangitaiki River. Male and female fish from the Tarawera River demonstrated 6- to 9-fold greater ethoxyresorufin-O¬-deethylase (EROD) activity compared to reference fish, indicating exposure to organic contaminants in this river. Tarawera females showed some minor variation in hematological variables including decreased mean cell volume (MCV), mean cell haemoglobin (MCH) and increased total white blood cell count (WBCC) suggestive of an immune response. Slightly greater ovarian follicular steroid production in Tarawera fish potentially indicates some form of endocrine alteration. However, this response may also be related to differences in reproductive synchrony and gonadal development between the two fish populations.

text: Biology of common bully (Gobiomorphus cotidianus) populations in the Tarawera and Rangitaiki Rivers: Reproductive isolation by inland distance or effluent discharges? Previous research identified distinct genetic, life-history and reproductive differences between populations of common bully (Gobiomorphus cotidianus) upstream and downstream of a pulp and paper mill outfall on the Tarawera River in the Bay of Plenty, New Zealand. This thesis sought to investigate the distribution of amphidromous and non-amphidromous common bully in the Tarawera River by examining fish collected from upstream (37 km inland) and downstream (20 km inland) locations and comparing them to fish from similar inland locations (40 km and 17 km inland, respectively) in the nearby Rangitaiki River. Otolith microchemistry revealed life-history differences between upstream and downstream populations and stable isotope analysis ensured long-term site residency. Amphidromy dominated in the downstream river populations, while the disappearance of diadromous fish generally occurred with inland distance. A mixture of diadromous and non-diadromous fish were found in the upstream Rangitaiki, while a complete absence of diadromous recruits was found in the upstream Tarawera River. A reduction in oculoscapular canal structures also coincided with loss of diadromy in fish from both rivers. Temporal reproductive divergence was investigated through track annual trends in gonadosomatic index.

The Tarawera River receives significant inputs from numerous industrial, municipal and natural sources, most notably from two pulp and paper mills. In the absence physical barriers in the Tarawera, it has been hypothesised that the lack of diadromous recruits in the upstream Tarawera River may be related to aquatic discharges in the downstream river. A behavioural study was performed to examine the hypothesis that pulp and paper mill effluent may be acting as a chemical barrier to fish migration within the river. A dual-choice chamber was employed to examine the responses of common bully exposed to a range of effluent concentrations (100, 50, 25, 12.5, 0% v/v). Fish exhibited significant avoidance responses when exposed to 100 and 50% effluent concentration, while no avoidance was observed at effluent concentrations below 50% This study demonstrated that common bully show a strong preference for river water when simultaneously exposed to effluent, albeit at environmentally unrealistic concentrations (i.e. greater than 15%), implicating potential for this effluent to act as a chemical barrier in the Tarawera River.
Following the establishment of reproductive timing of common bully in the Tarawera River, a wild fish health assessment was undertaken to investigate the effects of long-term effluent exposure in situ. Adult common bully were sampled downstream of the mill influence and compared to an appropriate reference population from the downstream Rangitaiki River. Male and female fish from the Tarawera River demonstrated 6- to 9-fold greater ethoxyresorufin-O¬-deethylase (EROD) activity compared to reference fish, indicating exposure to organic contaminants in this river. Tarawera females showed some minor variation in hematological variables including decreased mean cell volume (MCV), mean cell haemoglobin (MCH) and increased total white blood cell count (WBCC) suggestive of an immune response. Slightly greater ovarian follicular steroid production in Tarawera fish potentially indicates some form of endocrine alteration. However, this response may also be related to differences in reproductive synchrony and gonadal development between the two fish populations.

year: 2008

title: Re-designing the national imaginary: The development of Matariki as a contemporary festival

authors: Hardy, Ann

subjects: Aotearoa/New Zealand

abstract: This article considers the factors shaping the contemporary redevelopment in Aotearoa/ New Zealand of the indigenous commemoration of the rising of the constellation Matariki as a marker of seasonal change.  Through interviews with producers of media materials celebrating Matariki, it examines the ideological, cultural, and economic factors determining the encoding of the materials, investigating in particular the ways in which Matariki can resource a marketplace for spiritual commodities.

text: Re-designing the national imaginary: The development of Matariki as a contemporary festival This article considers the factors shaping the contemporary redevelopment in Aotearoa/ New Zealand of the indigenous commemoration of the rising of the constellation Matariki as a marker of seasonal change.  Through interviews with producers of media materials celebrating Matariki, it examines the ideological, cultural, and economic factors determining the encoding of the materials, investigating in particular the ways in which Matariki can resource a marketplace for spiritual commodities.

year: 2012