title: Spoof Surface Plasmon Polariton Leaky-Wave Antennas using Periodically Loaded Patches above PEC and AMC Ground Planes

authors: Zhang, Qingle

subjects: Leaky-wave antenna

abstract: This letter proposes two spoof surface plasmon polariton (SSPP) leaky-wave antennas using periodically loaded patches above perfect electric conductor (PEC) and artificial magnetic conductor (AMC) ground planes, respectively. The SSPP leaky-wave antenna is based on an SSPP transmission line, along which circular patches are periodically loaded on both sides to provide an additional momentum for phase matching with the radiated waves in the air. The PEC and AMC ground planes underneath the antenna reflect the radiated waves into the upward space, leading to an enhanced radiation gain. Both PEC- and AMC-grounded antenna prototypes are fabricated and measured in comparison with the one without any ground plane. The experimental results show that the PEC and AMC ground planes increase the radiation gain by approximately 3 dB within the operational frequency range 4.5-6.5 GHz. It also demonstrates that the AMC-grounded leaky-wave antenna, with a thickness of 0.08λ₀ at 6 GHz, features more compact profile than the PEC-grounded one (with a thickness of 0.3λ₀ at 6 GHz).

text: Spoof Surface Plasmon Polariton Leaky-Wave Antennas using Periodically Loaded Patches above PEC and AMC Ground Planes This letter proposes two spoof surface plasmon polariton (SSPP) leaky-wave antennas using periodically loaded patches above perfect electric conductor (PEC) and artificial magnetic conductor (AMC) ground planes, respectively. The SSPP leaky-wave antenna is based on an SSPP transmission line, along which circular patches are periodically loaded on both sides to provide an additional momentum for phase matching with the radiated waves in the air. The PEC and AMC ground planes underneath the antenna reflect the radiated waves into the upward space, leading to an enhanced radiation gain. Both PEC- and AMC-grounded antenna prototypes are fabricated and measured in comparison with the one without any ground plane. The experimental results show that the PEC and AMC ground planes increase the radiation gain by approximately 3 dB within the operational frequency range 4.5-6.5 GHz. It also demonstrates that the AMC-grounded leaky-wave antenna, with a thickness of 0.08λ₀ at 6 GHz, features more compact profile than the PEC-grounded one (with a thickness of 0.3λ₀ at 6 GHz).

year: 2017

title: Towards Robust Exchanges: Evaluating Ecological Compensation in New Zealand

authors: Brown, Marie Amanda

subjects: Resource Management Act

abstract: Ecological compensation is commonly employed but rarely evaluated around the world. In order to assess application of the tool in New Zealand, a systematic nationwide review was undertaken. The research used a combination of qualitative and quantitative tools (i.e. a mixed methods approach) to investigate outcomes associated with ecological compensation under the Resource Management Act 1991 and how variation among outcomes might be explained. Three key research components were addressed: compliance, practice and stakeholder perspectives.
Compliance
The levels of regulatory compliance were assessed in 81 consents and 245 conditions with an overall compliance level of 64.8%. Public organisations (75.5%) were more likely to comply than private companies (65.5%), followed by private individuals (54.7%). Administrative conditions (paper-based) were much more likely to be complied with (82.6%) than non-administrative (action based) conditions (49.6%). There were significant differences in compliance rates across different activities from Agriculture (4.8%) through to Energy Generation (100%), demonstrating the importance of understanding the nature of non-compliance in improving regulatory compliance and enforcement. 
Practice
The recognition of key implementation issues of ecological compensation were investigated based on the ecological exchanges approved in 110 consents. The key implementation issues were (1) equivalency, (2) spatial proximity, (3) additionality, (4) timing, (5) duration and compliance, and (6) currencies and ratios. Most exchanges approved under the RMA were ‘in-kind’ (i.e. broadly similar in type) but that their ecological equivalence was difficult to determine due to poor information. Most exchanges were close to the site of impact (65.5%), and those at a distance were typically the result of aggregated schemes such as mitigation trusts. Most requirements for ecological compensation can be considered to be additional, as there are few other means of compelling ecological restoration or other positive conservation activities in New Zealand. Most ecological compensation (94.5%) was required to be delivered concurrent with or after the activity that was approved with a range of mechanisms used to secure those outcomes. This research also showed that currencies and ratios are rarely used in the determination of ecological compensation.
Stakeholder perspectives
 Semi-structured interviews were conducted with 116 stakeholders from a wide range of disciplines, and demonstrated that while the potential of ecological compensation is well understood and its use is well-supported (96.5%), most stakeholders have significant concerns about implementation. Strong support (87.9%) exists for a more robust and formalized approach to ecological compensation.
For ecological compensation to contribute positively to the management of effects on the environment, the exchanges of biodiversity lost and gained must be robust. The present research has demonstrated that the implementation of ecological compensation in New Zealand is falling short of this expectation, and has identified a range of areas for improvement. The significant potential for failure inherent within ecological compensation requires mitigation with policy and practice improvements, and comprehensive follow-up and review of outcomes. Changes in the use of ecological compensation in New Zealand, toward a context that supports more robust exchanges and limits the potential for negative impact of the tool upon ecosystems and species are essential.

text: Towards Robust Exchanges: Evaluating Ecological Compensation in New Zealand Ecological compensation is commonly employed but rarely evaluated around the world. In order to assess application of the tool in New Zealand, a systematic nationwide review was undertaken. The research used a combination of qualitative and quantitative tools (i.e. a mixed methods approach) to investigate outcomes associated with ecological compensation under the Resource Management Act 1991 and how variation among outcomes might be explained. Three key research components were addressed: compliance, practice and stakeholder perspectives.
Compliance
The levels of regulatory compliance were assessed in 81 consents and 245 conditions with an overall compliance level of 64.8%. Public organisations (75.5%) were more likely to comply than private companies (65.5%), followed by private individuals (54.7%). Administrative conditions (paper-based) were much more likely to be complied with (82.6%) than non-administrative (action based) conditions (49.6%). There were significant differences in compliance rates across different activities from Agriculture (4.8%) through to Energy Generation (100%), demonstrating the importance of understanding the nature of non-compliance in improving regulatory compliance and enforcement. 
Practice
The recognition of key implementation issues of ecological compensation were investigated based on the ecological exchanges approved in 110 consents. The key implementation issues were (1) equivalency, (2) spatial proximity, (3) additionality, (4) timing, (5) duration and compliance, and (6) currencies and ratios. Most exchanges approved under the RMA were ‘in-kind’ (i.e. broadly similar in type) but that their ecological equivalence was difficult to determine due to poor information. Most exchanges were close to the site of impact (65.5%), and those at a distance were typically the result of aggregated schemes such as mitigation trusts. Most requirements for ecological compensation can be considered to be additional, as there are few other means of compelling ecological restoration or other positive conservation activities in New Zealand. Most ecological compensation (94.5%) was required to be delivered concurrent with or after the activity that was approved with a range of mechanisms used to secure those outcomes. This research also showed that currencies and ratios are rarely used in the determination of ecological compensation.
Stakeholder perspectives
 Semi-structured interviews were conducted with 116 stakeholders from a wide range of disciplines, and demonstrated that while the potential of ecological compensation is well understood and its use is well-supported (96.5%), most stakeholders have significant concerns about implementation. Strong support (87.9%) exists for a more robust and formalized approach to ecological compensation.
For ecological compensation to contribute positively to the management of effects on the environment, the exchanges of biodiversity lost and gained must be robust. The present research has demonstrated that the implementation of ecological compensation in New Zealand is falling short of this expectation, and has identified a range of areas for improvement. The significant potential for failure inherent within ecological compensation requires mitigation with policy and practice improvements, and comprehensive follow-up and review of outcomes. Changes in the use of ecological compensation in New Zealand, toward a context that supports more robust exchanges and limits the potential for negative impact of the tool upon ecosystems and species are essential.

year: 2014

title: A discontinuous ca. 80 ka record of Late Quaternary environmental change from Lake Omapere, Northland, New Zealand

authors: Newnham, Rewi M.

subjects: Last Glacial

abstract: We present an integrated record of environmental change from Lake Omapere, Northland, New Zealand, based on palaeolimnological analysis of a 7-m-long core and eight adjunct cores spanning part of the last 80 calendar (cal.) ka. The chronology was developed using tephrochronology, palaeomagnetism and radiocarbon dating together with climato- and palyno-stratigraphy. Two of 14 tephra layers in the cores provide markers for correlating the record with other New Zealand climato-stratigraphic sequences, deep-sea cores and the global marine isotope record. Pollen, diatom, palaeomagnetic, sedimentologic and pigment analyses show that Lake Omapere, currently 2 m deep, has had a discontinuous history. Occupying a shallow basin perched partly within old basalt lavas, the initial (alkaline) lake formed towards the end of MIS 5a at ca. 80 cal. ka, presumably because of blockage of local drainage of a swampy alluvial floodplain, inundating peat deposits and forest trees, including kauri (Agathis australis). The lake filled rapidly to a level 1–2 m above that at present. Such filling was probably unrelated to climate but a subsequent phase of variable but generally falling lake levels and increasing dystrophy may have been climatically controlled, commencing during MIS 4 and culminating in periods early in MIS 3 when the lake became swampy or dry. Conditions of non-deposition (or non-preservation) obtained for most of the period after ca. 55 cal. ka (Rotoehu Ash) until formation of the modern lake approximately 600–700 cal. years ago or soon after, as indicated by the presence of Tephra-1, identified in part as Kaharoa Tephra (AD 1314), near the top of the core. The modern lake originated possibly through damming of the western outlet as a consequence of accelerated erosion accompanying earliest Polynesian deforestation, an interpretation supported by Maori oral tradition.
The pollen record indicates that beech Nothofagus (presumably N. truncata) was much more common in Northland during the Last Glacial, and that for this region the relative abundance of Nothofagus vs. Agathis pollen serves as a better indicator of cooler versus warmer intervals during the Quaternary than the ratio of tree to non-tree pollen. However, it seems likely that moisture balance was a more critical factor than temperature in vegetation composition and distribution, particularly during the LGM, and the long periods of hiatus may also be linked to a drier climate than present. Correlation coefficients between the pollen curves confirm that several tree species (Halocarpus bidwillii, H. biformis and Phyllocladus alpinus), previously palynologically concealed within generic taxonomic groups, occurred about two degrees latitude further north and at a much lower altitude than their current limits during cooler or drier phases of the Last Glacial. A temperature depression in Northland of 4 °C at various times during the Last Glacial is inferred from these range expansions. Nevertheless, the persistence of widespread forest cover suggests that the late Pleistocene climate of Northland was less severe than for most of the rest of New Zealand and strengthens the argument for a heightened temperature gradient across northern New Zealand during the Last Glacial.

text: A discontinuous ca. 80 ka record of Late Quaternary environmental change from Lake Omapere, Northland, New Zealand We present an integrated record of environmental change from Lake Omapere, Northland, New Zealand, based on palaeolimnological analysis of a 7-m-long core and eight adjunct cores spanning part of the last 80 calendar (cal.) ka. The chronology was developed using tephrochronology, palaeomagnetism and radiocarbon dating together with climato- and palyno-stratigraphy. Two of 14 tephra layers in the cores provide markers for correlating the record with other New Zealand climato-stratigraphic sequences, deep-sea cores and the global marine isotope record. Pollen, diatom, palaeomagnetic, sedimentologic and pigment analyses show that Lake Omapere, currently 2 m deep, has had a discontinuous history. Occupying a shallow basin perched partly within old basalt lavas, the initial (alkaline) lake formed towards the end of MIS 5a at ca. 80 cal. ka, presumably because of blockage of local drainage of a swampy alluvial floodplain, inundating peat deposits and forest trees, including kauri (Agathis australis). The lake filled rapidly to a level 1–2 m above that at present. Such filling was probably unrelated to climate but a subsequent phase of variable but generally falling lake levels and increasing dystrophy may have been climatically controlled, commencing during MIS 4 and culminating in periods early in MIS 3 when the lake became swampy or dry. Conditions of non-deposition (or non-preservation) obtained for most of the period after ca. 55 cal. ka (Rotoehu Ash) until formation of the modern lake approximately 600–700 cal. years ago or soon after, as indicated by the presence of Tephra-1, identified in part as Kaharoa Tephra (AD 1314), near the top of the core. The modern lake originated possibly through damming of the western outlet as a consequence of accelerated erosion accompanying earliest Polynesian deforestation, an interpretation supported by Maori oral tradition.
The pollen record indicates that beech Nothofagus (presumably N. truncata) was much more common in Northland during the Last Glacial, and that for this region the relative abundance of Nothofagus vs. Agathis pollen serves as a better indicator of cooler versus warmer intervals during the Quaternary than the ratio of tree to non-tree pollen. However, it seems likely that moisture balance was a more critical factor than temperature in vegetation composition and distribution, particularly during the LGM, and the long periods of hiatus may also be linked to a drier climate than present. Correlation coefficients between the pollen curves confirm that several tree species (Halocarpus bidwillii, H. biformis and Phyllocladus alpinus), previously palynologically concealed within generic taxonomic groups, occurred about two degrees latitude further north and at a much lower altitude than their current limits during cooler or drier phases of the Last Glacial. A temperature depression in Northland of 4 °C at various times during the Last Glacial is inferred from these range expansions. Nevertheless, the persistence of widespread forest cover suggests that the late Pleistocene climate of Northland was less severe than for most of the rest of New Zealand and strengthens the argument for a heightened temperature gradient across northern New Zealand during the Last Glacial.

year: 2004