title: Bioavailability of phosphorus transported during storm flow to a eutrophic, polymictic lake

authors: Abell, Jonathan Michael

subjects: algal assays

abstract: The bioavailability of catchment-derived particulate phosphorus (PP) to lentic phytoplankton was investigated. Two stream inflows to Lake Rotorua (Bay of Plenty, New Zealand) were sampled during moderate (March) and large (August) discharge peaks in 2012. Phosphorus (P) fractions in samples were quantified and a bioassay was undertaken using samples from the March event to determine whether P-limited phytoplankton could utilise PP. Phosphorus composition differed markedly between events but was comparable between streams. For the March event, all PP (persulphate extractable) was bioavailable if exposed to anoxia, whereas c. 25% was potentially bioavailable for the August event. Despite this, the laboratory bioassay indicated that, under oxic conditions, suspended sediments acted as a sink rather than a source of bioavailable P to P-limited phytoplankton. This study highlights the importance of considering P speciation and the nature of the receiving environment when assessing the bioavailability of P transported through hydrological landscapes.

text: Bioavailability of phosphorus transported during storm flow to a eutrophic, polymictic lake The bioavailability of catchment-derived particulate phosphorus (PP) to lentic phytoplankton was investigated. Two stream inflows to Lake Rotorua (Bay of Plenty, New Zealand) were sampled during moderate (March) and large (August) discharge peaks in 2012. Phosphorus (P) fractions in samples were quantified and a bioassay was undertaken using samples from the March event to determine whether P-limited phytoplankton could utilise PP. Phosphorus composition differed markedly between events but was comparable between streams. For the March event, all PP (persulphate extractable) was bioavailable if exposed to anoxia, whereas c. 25% was potentially bioavailable for the August event. Despite this, the laboratory bioassay indicated that, under oxic conditions, suspended sediments acted as a sink rather than a source of bioavailable P to P-limited phytoplankton. This study highlights the importance of considering P speciation and the nature of the receiving environment when assessing the bioavailability of P transported through hydrological landscapes.

year: 2013

title: Active scheduling for hybrid flowshop with family setup time and inconsistent family formation

authors: Luo, Hao

subjects: hybrid flowshop scheduling

abstract: This research is motivated by a real-life hybrid flowshop scheduling problem where jobs are organized in families according to their machine settings and tools. This type of problem is common in the production process of standard metal components. The problem is complicated by the requirement of family setup time when a machine changes from processing one job family to another and the formation of job families varies in different stages. This problem has been previously solved with a non-delay scheduling heuristic in which no machine is kept idle. This research illustrates that inserting intentional idle time into a non-delay schedule can further reduce the total setup time as well as makespan. With the inserted idle time, the non-delay schedules are extended to active schedules. This paper presents a mechanism to determine the locations and lengths of intentional idle times in the efficient active schedules. Four active scheduling approaches are developed by integrating two types of waiting factor operators into two non-delay approaches. Computational experiments have been conducted to compare the proposed active scheduling approaches in terms of effectiveness and efficiency. The results have shown that the proposed active scheduling approaches are superior to non-delay scheduling. The analysis of variance has been applied on the factors related to scheduling environment, problem size and scheduling approach. The analysis has identified factors that are most influential on the scheduling result.

text: Active scheduling for hybrid flowshop with family setup time and inconsistent family formation This research is motivated by a real-life hybrid flowshop scheduling problem where jobs are organized in families according to their machine settings and tools. This type of problem is common in the production process of standard metal components. The problem is complicated by the requirement of family setup time when a machine changes from processing one job family to another and the formation of job families varies in different stages. This problem has been previously solved with a non-delay scheduling heuristic in which no machine is kept idle. This research illustrates that inserting intentional idle time into a non-delay schedule can further reduce the total setup time as well as makespan. With the inserted idle time, the non-delay schedules are extended to active schedules. This paper presents a mechanism to determine the locations and lengths of intentional idle times in the efficient active schedules. Four active scheduling approaches are developed by integrating two types of waiting factor operators into two non-delay approaches. Computational experiments have been conducted to compare the proposed active scheduling approaches in terms of effectiveness and efficiency. The results have shown that the proposed active scheduling approaches are superior to non-delay scheduling. The analysis of variance has been applied on the factors related to scheduling environment, problem size and scheduling approach. The analysis has identified factors that are most influential on the scheduling result.

year: 2013

title: Māori & Psychology Research Unit annual report 2011

authors: Rua, Mohi

subjects: Māori and Psychology Research Unit

abstract: Annual report of the Māori and Psychology Research Unit (MPRU) 2011. The unit was established in August of 1997. The unit is designed to provide a catalyst and support network for enhancing research concerning the psychological needs, aspirations, and priorities of Maori people. The MPRU is well situated to draw together skilled and experienced interdisciplinary research groups by networking and establishing working relationships with staff and students within the Faculty of Arts and Social Sciences, the University, and the wider community.

text: Māori & Psychology Research Unit annual report 2011 Annual report of the Māori and Psychology Research Unit (MPRU) 2011. The unit was established in August of 1997. The unit is designed to provide a catalyst and support network for enhancing research concerning the psychological needs, aspirations, and priorities of Maori people. The MPRU is well situated to draw together skilled and experienced interdisciplinary research groups by networking and establishing working relationships with staff and students within the Faculty of Arts and Social Sciences, the University, and the wider community.

year: 2012