title: Recent studies of sediment capping and flocculation for nutrient stabilisation

authors: Özkundakci, Deniz

subjects: New Zealand

abstract: Water quality in the Rotorua Lakes has declined in the past 30 to 40 years due to increasing nutrient loads, specifically nitrogen and phosphorus. In situ restoration techniques, including sediment capping and flocculation, have been developed to attempt to reduce internal nutrient loads, which can be comparable in magnitude to external loads in eutrophic lakes. The aim of this report is to summarise the current state of knowledge, and to documents some recent studies of sediment capping and flocculation techniques designed to remove nutrients from the water column by retaining them permanently within the bottom sediments. Experimental set-ups for testing the efficacy of different materials range from conventional batch adsorption studies to sediment reactor experiments. Natural ecosystems have also been simulated with mesocosms in Lake Okaro. A full scale application of aluminium sulphate (alum) in Lake Okar. A full scale application of aluminium sulphate (alum) in Lake Okaro has also been intensively monitored. The different studies have provided information on the restoration potential of some sediment capping agents and flocculants, but many questions still remain. Given the current state of knowledge it is not possible to confirm a priori the circumstances under which a whole lake trial would be successful. Future research should be carried out on the follow foci:
•	Establishment of chronic or acute toxic effects of the adsorbent materials.
•	Effect of treatment applications on benthic biota, particularly capping materials that may alter physical characteristics of the sediments.
•	Application of computer models for the purpose of both hindcasting and better understanding effects of application of an adsorbent to a lake, and for the purpose of predicting the changes in trophic status.
•	Application techniques and costs, particularly in view of potential for quite radical changes in source of adsorbent materials, grain sizes and methods of application for a single adsorbent.

text: Recent studies of sediment capping and flocculation for nutrient stabilisation Water quality in the Rotorua Lakes has declined in the past 30 to 40 years due to increasing nutrient loads, specifically nitrogen and phosphorus. In situ restoration techniques, including sediment capping and flocculation, have been developed to attempt to reduce internal nutrient loads, which can be comparable in magnitude to external loads in eutrophic lakes. The aim of this report is to summarise the current state of knowledge, and to documents some recent studies of sediment capping and flocculation techniques designed to remove nutrients from the water column by retaining them permanently within the bottom sediments. Experimental set-ups for testing the efficacy of different materials range from conventional batch adsorption studies to sediment reactor experiments. Natural ecosystems have also been simulated with mesocosms in Lake Okaro. A full scale application of aluminium sulphate (alum) in Lake Okar. A full scale application of aluminium sulphate (alum) in Lake Okaro has also been intensively monitored. The different studies have provided information on the restoration potential of some sediment capping agents and flocculants, but many questions still remain. Given the current state of knowledge it is not possible to confirm a priori the circumstances under which a whole lake trial would be successful. Future research should be carried out on the follow foci:
•	Establishment of chronic or acute toxic effects of the adsorbent materials.
•	Effect of treatment applications on benthic biota, particularly capping materials that may alter physical characteristics of the sediments.
•	Application of computer models for the purpose of both hindcasting and better understanding effects of application of an adsorbent to a lake, and for the purpose of predicting the changes in trophic status.
•	Application techniques and costs, particularly in view of potential for quite radical changes in source of adsorbent materials, grain sizes and methods of application for a single adsorbent.

year: 2006

title: Conflict-preserving abstraction of discrete event systems using annotated automata

authors: Ware, Simon

subjects: computer science

abstract: This paper proposes to enhance compositional verification of the nonblocking property of discrete event systems by introducing annotated automata. Annotations store nondeterministic branching information, which would otherwise be stored in extra states and transitions. This succinct representation makes it easier to simplify automata and enables new efficientmeans of abstraction, reducing the size of automata to be composed and thus the size of the synchronous product state space encountered in verification. The abstractions proposed are of polynomial complexity, and they have been successfully applied to model check the nonblocking property of the same set of large-scale industrial examples as used in related work.

text: Conflict-preserving abstraction of discrete event systems using annotated automata This paper proposes to enhance compositional verification of the nonblocking property of discrete event systems by introducing annotated automata. Annotations store nondeterministic branching information, which would otherwise be stored in extra states and transitions. This succinct representation makes it easier to simplify automata and enables new efficientmeans of abstraction, reducing the size of automata to be composed and thus the size of the synchronous product state space encountered in verification. The abstractions proposed are of polynomial complexity, and they have been successfully applied to model check the nonblocking property of the same set of large-scale industrial examples as used in related work.

year: 2012

title: Responding to the message: Responsive written feedback in a Maori to English transition context

authors: Glynn, Ted

subjects: New Zealand

abstract: This paper reports on the writing component of a community and
school Maori to English literacy transition programme implemented in a kura
kaupapa Maori (Maori language immersion school. 21 Year 6, 7 and 8
students received responsive written feedback for their writing in English,
over a ten-week period, during their weekly independent writing time.
Students’ stories were mailed to a young Maori woman (the third author) in a
provincial city 100 kilometres from the kura . She was not known to any of the
students prior to the study, but she acted as an interested audience, and
responded in writing by focussing on the content or messages in students’
stories. She did not provide any corrective feedback on students’ writing.
The study employed an intra-subject multiple-baseline research design across
four school terms, with the responsive written feedback being introduced
sequentially to each of three student Year groups. Measures were taken of
total words written, adventurous words written, as well as holistic ratings of
audience impact and language quality. Data demonstrate positive gains in
both the quantity and quality of students’ writing, as well as maintenance of
high levels of writing accuracy for all Year groups.

text: Responding to the message: Responsive written feedback in a Maori to English transition context This paper reports on the writing component of a community and
school Maori to English literacy transition programme implemented in a kura
kaupapa Maori (Maori language immersion school. 21 Year 6, 7 and 8
students received responsive written feedback for their writing in English,
over a ten-week period, during their weekly independent writing time.
Students’ stories were mailed to a young Maori woman (the third author) in a
provincial city 100 kilometres from the kura . She was not known to any of the
students prior to the study, but she acted as an interested audience, and
responded in writing by focussing on the content or messages in students’
stories. She did not provide any corrective feedback on students’ writing.
The study employed an intra-subject multiple-baseline research design across
four school terms, with the responsive written feedback being introduced
sequentially to each of three student Year groups. Measures were taken of
total words written, adventurous words written, as well as holistic ratings of
audience impact and language quality. Data demonstrate positive gains in
both the quantity and quality of students’ writing, as well as maintenance of
high levels of writing accuracy for all Year groups.

year: 2005