title: Subseafloor Investigation of Sediments at Southern Tauranga Harbour, New Zealand, before Capital Dredging

authors: Jorat, M. Ehsan

subjects: Science & Technology

abstract: The Port of Tauranga plays a key role in New Zealand's export–import industry, and capital dredging commenced in October 2015 to extend the shipping channels to accommodate larger container vessels. This study investigated two-dimensional and three-dimensional subsurface estuarine sediment stratigraphy to predict the sedimentological conditions encountered during dredging operations to ensure that appropriate dredging methodologies were used to minimise the generation of turbidity. Eight cone penetration tests (CPTs), 14 core descriptions, and a high-resolution seismic investigation in Stella Passage (the main shipping channel of Tauranga Harbour) provided the basis for this research. Six major units comprise the stratigraphy; in ascending order they are lower pumiceous sand and silt (UNIT6), quartz-feldspar sand and silt (UNIT5), middle pumiceous sand and silt (UNIT4), silt–sand–clay (UNIT3), upper pumiceous sand and silt (UNIT2), and Holocene marine (UNIT1) sediments forming the modern seafloor. Three paleovalleys filled with sediments from UNIT2 were identified extending west to east across the channel. The CPT profiles were correlated with the seismostratigraphic units and their corresponding soil behaviour type to characterise each unit's sediment stiffness. The UNIT6 is unlikely to be encountered in current and future capital dredging operations because it is the lowest observed unit. A special dredging methodology may be required for UNIT5 and UNIT4 as they have high CPT tip resistance and undrained shear strength. For UNIT3, UNIT2, and UNIT1, which have very low CPT tip resistance and undrained shear strength, trailing suction and cutter suction dredging is appropriate. The potential turbidity of the water column, however, could impose a significant threat to marine biota and has to be taken into account.

text: Subseafloor Investigation of Sediments at Southern Tauranga Harbour, New Zealand, before Capital Dredging The Port of Tauranga plays a key role in New Zealand's export–import industry, and capital dredging commenced in October 2015 to extend the shipping channels to accommodate larger container vessels. This study investigated two-dimensional and three-dimensional subsurface estuarine sediment stratigraphy to predict the sedimentological conditions encountered during dredging operations to ensure that appropriate dredging methodologies were used to minimise the generation of turbidity. Eight cone penetration tests (CPTs), 14 core descriptions, and a high-resolution seismic investigation in Stella Passage (the main shipping channel of Tauranga Harbour) provided the basis for this research. Six major units comprise the stratigraphy; in ascending order they are lower pumiceous sand and silt (UNIT6), quartz-feldspar sand and silt (UNIT5), middle pumiceous sand and silt (UNIT4), silt–sand–clay (UNIT3), upper pumiceous sand and silt (UNIT2), and Holocene marine (UNIT1) sediments forming the modern seafloor. Three paleovalleys filled with sediments from UNIT2 were identified extending west to east across the channel. The CPT profiles were correlated with the seismostratigraphic units and their corresponding soil behaviour type to characterise each unit's sediment stiffness. The UNIT6 is unlikely to be encountered in current and future capital dredging operations because it is the lowest observed unit. A special dredging methodology may be required for UNIT5 and UNIT4 as they have high CPT tip resistance and undrained shear strength. For UNIT3, UNIT2, and UNIT1, which have very low CPT tip resistance and undrained shear strength, trailing suction and cutter suction dredging is appropriate. The potential turbidity of the water column, however, could impose a significant threat to marine biota and has to be taken into account.

year: 2017-03-01

title: Partial Order Reduction with Compositional Verification

authors: Shaw, Adrian Mark

subjects: Partial order reduction

abstract: This thesis expands the usage of partial order reduction methods in reducing the state space of large models in model checking. The work done can be divided into two parts. In the first part we introduce two new ample conditions that utilise strongly connected components in place of two existing ample conditions that use cycles. We use these new conditions to optimise existing partial order reduction verifiers and extend them to verify nonblocking properties. We also introduce two selection strategies for choosing ample event sets and an improved ample algorithm in order to improve the efficiency of ample set computation, and investigate how the various combinations of these suggested algorithmic improvements effect several models of varying size. The second part of the thesis introduces the concept of using partial order reduction techniques in combination with compositional verification techniques. We introduce a modified version of the silent continuation rule that makes use of the independence relationship from partial order reduction methods and include algorithms by which they may be implemented in a model verifier. All of the original concepts developed in this thesis are also proven correct.

text: Partial Order Reduction with Compositional Verification This thesis expands the usage of partial order reduction methods in reducing the state space of large models in model checking. The work done can be divided into two parts. In the first part we introduce two new ample conditions that utilise strongly connected components in place of two existing ample conditions that use cycles. We use these new conditions to optimise existing partial order reduction verifiers and extend them to verify nonblocking properties. We also introduce two selection strategies for choosing ample event sets and an improved ample algorithm in order to improve the efficiency of ample set computation, and investigate how the various combinations of these suggested algorithmic improvements effect several models of varying size. The second part of the thesis introduces the concept of using partial order reduction techniques in combination with compositional verification techniques. We introduce a modified version of the silent continuation rule that makes use of the independence relationship from partial order reduction methods and include algorithms by which they may be implemented in a model verifier. All of the original concepts developed in this thesis are also proven correct.

year: 2014

title: Experiences of New Zealand Māori mothers’ Engagement with health and social services post-COVID-19 2020 lockdown

authors: Barrett, Nikki Maree

subjects: Childbirth

abstract: Background: 
Despite universal provision of maternity care, Māori (Indigenous peoples of Aotearoa/New Zealand) experience significant maternal and infant health disparities compared to their dominant Pākehā (non-Māori) counterparts. This paper examined the lived realities of postnatal Māori māmā (mothers) engaging with health and social services. Enablers and barriers were identified to better understand what is required to strengthen health services’ responsiveness to Māori māmā health needs and aspirations. 

Methods: 
Underpinned by Kaupapa Māori research principles, which are grounded in Māori cultural values, emphasising self-determination, and Māori aspirations, a small cohort of 17 expectant Māori māmā were recruited from a Māori childbirth education programme to participate in a three-phase study. Phase three, the focus of this paper, involved seven semi-structured, open-ended telephone interviews with Māori māmā. A thematic analysis, underpinned by a mana wahine (authority inherent in Māori women) theoretical perspective amplified these experiences. 

Results: 
Five themes were identified that encapsulated participants’ engagement and interactions with health and social services. These themes were as follows: (1) right to enact tino rangatiratanga (autonomy) and self-achievement; (2) responsiveness of services; (3) service and system issues; (4) need for greater choice and opportunity; and (5) impact of COVID-19. 

Conclusions: 
This study privileged the voices of Māori wāhine, highlighting their experiences with a complex and often unresponsive health system. Participants valued services that enabled them to exercise tino rangatiratanga. Echoing the experiences of other Indigenous Peoples, incorporating culturally relevant practices into perinatal health services is crucial for achieving health equity and addressing disparities.

text: Experiences of New Zealand Māori mothers’ Engagement with health and social services post-COVID-19 2020 lockdown Background: 
Despite universal provision of maternity care, Māori (Indigenous peoples of Aotearoa/New Zealand) experience significant maternal and infant health disparities compared to their dominant Pākehā (non-Māori) counterparts. This paper examined the lived realities of postnatal Māori māmā (mothers) engaging with health and social services. Enablers and barriers were identified to better understand what is required to strengthen health services’ responsiveness to Māori māmā health needs and aspirations. 

Methods: 
Underpinned by Kaupapa Māori research principles, which are grounded in Māori cultural values, emphasising self-determination, and Māori aspirations, a small cohort of 17 expectant Māori māmā were recruited from a Māori childbirth education programme to participate in a three-phase study. Phase three, the focus of this paper, involved seven semi-structured, open-ended telephone interviews with Māori māmā. A thematic analysis, underpinned by a mana wahine (authority inherent in Māori women) theoretical perspective amplified these experiences. 

Results: 
Five themes were identified that encapsulated participants’ engagement and interactions with health and social services. These themes were as follows: (1) right to enact tino rangatiratanga (autonomy) and self-achievement; (2) responsiveness of services; (3) service and system issues; (4) need for greater choice and opportunity; and (5) impact of COVID-19. 

Conclusions: 
This study privileged the voices of Māori wāhine, highlighting their experiences with a complex and often unresponsive health system. Participants valued services that enabled them to exercise tino rangatiratanga. Echoing the experiences of other Indigenous Peoples, incorporating culturally relevant practices into perinatal health services is crucial for achieving health equity and addressing disparities.

year: 2025