title: The changing face of Lake Okataina’s ‘phosphorus scape’: Who is the culprit?

authors: Kpodonu, Theodore

abstract: Lake sediments contain a great wealth of data on biogeochemical and limnological processes of historical importance, which can be used to interpret natural ecosystem dynamics, and climatic and anthropogenic impacts. In this study, this information was used to understand the dynamics of phosphorus speciation in deep Lake Okataina, to assist with understanding how changes in the catchment influence lake productivity. A 49-cm sediment core was retrieved from Lake Okataina and its depositional history was dated using 210Pb and tephra chronology. Amongst New Zealand lakes, Okataina may be considered close to a ‘reference’ lake, with 89% native forest and without a significant change in its land use in the past c. 800 years. However, perturbations to the lake during this time may be due to expanding populations of invasive terrestrial mammals, earthquakes, volcanic eruptions and tree felling, which may alter the geochemistry of the soils in the catchment, composition of runoff and, ultimately, the composition of the bottom sediments of the lake. We hypothesised that changes in soil phosphorus geochemistry in the catchment will result in a changing phosphorus species in the lake sediments.

text: The changing face of Lake Okataina’s ‘phosphorus scape’: Who is the culprit? Lake sediments contain a great wealth of data on biogeochemical and limnological processes of historical importance, which can be used to interpret natural ecosystem dynamics, and climatic and anthropogenic impacts. In this study, this information was used to understand the dynamics of phosphorus speciation in deep Lake Okataina, to assist with understanding how changes in the catchment influence lake productivity. A 49-cm sediment core was retrieved from Lake Okataina and its depositional history was dated using 210Pb and tephra chronology. Amongst New Zealand lakes, Okataina may be considered close to a ‘reference’ lake, with 89% native forest and without a significant change in its land use in the past c. 800 years. However, perturbations to the lake during this time may be due to expanding populations of invasive terrestrial mammals, earthquakes, volcanic eruptions and tree felling, which may alter the geochemistry of the soils in the catchment, composition of runoff and, ultimately, the composition of the bottom sediments of the lake. We hypothesised that changes in soil phosphorus geochemistry in the catchment will result in a changing phosphorus species in the lake sediments.

year: 2015

title: Flexibility Analysis of Heat Exchanger Network Retrofit Designs using Monte Carlo Simulation

authors: Lal, Nathan S.

abstract: The aim of this paper is to use Monte Carlo Simulation (MCS) to conduct an analysis of the flexibility and controllability of retrofitted Heat Exchanger Network (HEN) designs. Historical plant data is often uncertain and variable but is an important tool for understanding the real-time operation of a HEN. MCS uses these uncertainties to give an analysis of the retrofitted HENs, and it can be used in a more detailed analysis of the controllability and flexibility. Using Monte Carlo Simulation, inflexibility has been defined as the probability of a HEN to fail to meet temperature targets within defined tolerances. Inflexibility can be used as a tool to guide the retrofit analysis of a HEN. A retrofit HEN design should improve the flexibility of the network without compromising on the expected energy savings. The proposed method is demonstrated using a four-stream HEN problem. The inflexibility of the network was shown to be improved with bypass control and optimal allocation of retrofit area and the proposed method succeeds in augmenting the retrofit design method so that cost-effective, flexible retrofit HENs can be identified.

text: Flexibility Analysis of Heat Exchanger Network Retrofit Designs using Monte Carlo Simulation The aim of this paper is to use Monte Carlo Simulation (MCS) to conduct an analysis of the flexibility and controllability of retrofitted Heat Exchanger Network (HEN) designs. Historical plant data is often uncertain and variable but is an important tool for understanding the real-time operation of a HEN. MCS uses these uncertainties to give an analysis of the retrofitted HENs, and it can be used in a more detailed analysis of the controllability and flexibility. Using Monte Carlo Simulation, inflexibility has been defined as the probability of a HEN to fail to meet temperature targets within defined tolerances. Inflexibility can be used as a tool to guide the retrofit analysis of a HEN. A retrofit HEN design should improve the flexibility of the network without compromising on the expected energy savings. The proposed method is demonstrated using a four-stream HEN problem. The inflexibility of the network was shown to be improved with bypass control and optimal allocation of retrofit area and the proposed method succeeds in augmenting the retrofit design method so that cost-effective, flexible retrofit HENs can be identified.

year: 2019

title: Evaluation of the Whānau Ora Wellbeing Service of Te Whakaruruhau: Final report

authors: Robertson, Neville

subjects: whānau ora

abstract: Domestic violence and child abuse represent significant threats to whānau ora. Conversely, the weakening or loss of whānau ties can increase the vulnerability of whānau members to domestic violence and child abuse. Thus enhancing whānau ora in the context of domestic violence and child abuse is both a high priority and a significant challenge.

Te Whakaruruhau Māori Women’s Refuge has been providing safe housing, support and advocacy to women and children for over two decades and has become a key agency in family violence networks in Kirikiriroa. The development of the Whānau Ora Wellbeing Service, the focus of this evaluation, was a logical extension of Refuge services.

The Māori and Psychology Research Unit was commissioned in mid‐2011 to conduct this evaluation. It is based on ten case studies of clients in the programme, interviews with Te Whakaruruhau staff and key informants in allied agencies, and participant‐observation of Refuge activities. The case studies provide insights into the lived experience of women dealing with violence, their attempts to protect themselves and their children, and their experiences of – and reflections upon – the Whānau Ora Wellbeing programme.

text: Evaluation of the Whānau Ora Wellbeing Service of Te Whakaruruhau: Final report Domestic violence and child abuse represent significant threats to whānau ora. Conversely, the weakening or loss of whānau ties can increase the vulnerability of whānau members to domestic violence and child abuse. Thus enhancing whānau ora in the context of domestic violence and child abuse is both a high priority and a significant challenge.

Te Whakaruruhau Māori Women’s Refuge has been providing safe housing, support and advocacy to women and children for over two decades and has become a key agency in family violence networks in Kirikiriroa. The development of the Whānau Ora Wellbeing Service, the focus of this evaluation, was a logical extension of Refuge services.

The Māori and Psychology Research Unit was commissioned in mid‐2011 to conduct this evaluation. It is based on ten case studies of clients in the programme, interviews with Te Whakaruruhau staff and key informants in allied agencies, and participant‐observation of Refuge activities. The case studies provide insights into the lived experience of women dealing with violence, their attempts to protect themselves and their children, and their experiences of – and reflections upon – the Whānau Ora Wellbeing programme.

year: 2013-07-20