title: Responses of free-ranging house sparrows to feed containing primary and secondary repellents

authors: Day, Tim D.

subjects: agricultural lime

abstract: We recorded the responses of free-ranging house sparrows (Passer domesticus) to various concentrations of primary repellents and a secondary repellent. Wheat treated with either lime or neem oil was consumed by sparrows at the same rate over 24 hours as plain wheat at all doses. d-pulegone significantly reduced wheat consumption from day 1 onwards throughout the 4 days. Avex™ (containing the secondary repellent anthraquinone) did not significantly reduce wheat consumption on day 1 of exposure, but sparrows ate progressively less repellent wheat over the following days. For both d-pulegone and Avex™, there was a negative relationship between wheat consumption and repellent concentration. In experiment 2, the highest concentrations of Avex™ + d-pulegone combined reduced daily wheat consumption significantly more than Avex™ alone and the effect lasted throughout the 10-day test. These results demonstrate the potential of primary and secondary repellents, presented alone or in combination, for modifying the feeding behaviour of sparrows.

text: Responses of free-ranging house sparrows to feed containing primary and secondary repellents We recorded the responses of free-ranging house sparrows (Passer domesticus) to various concentrations of primary repellents and a secondary repellent. Wheat treated with either lime or neem oil was consumed by sparrows at the same rate over 24 hours as plain wheat at all doses. d-pulegone significantly reduced wheat consumption from day 1 onwards throughout the 4 days. Avex™ (containing the secondary repellent anthraquinone) did not significantly reduce wheat consumption on day 1 of exposure, but sparrows ate progressively less repellent wheat over the following days. For both d-pulegone and Avex™, there was a negative relationship between wheat consumption and repellent concentration. In experiment 2, the highest concentrations of Avex™ + d-pulegone combined reduced daily wheat consumption significantly more than Avex™ alone and the effect lasted throughout the 10-day test. These results demonstrate the potential of primary and secondary repellents, presented alone or in combination, for modifying the feeding behaviour of sparrows.

year: 2011

title: Rapid online detection of nitrate and quantification of nitrate removal via capacitive deionisation (CDI)

authors: Jose, Jojo

subjects: Nitrate detection

abstract: Abstract
The increasing nitrate contamination in water poses significant environmental and public health challenges. With the rapid development of Capacitive Deionization (CDI) as a low-cost point-of-use (POU) solution to the problem, there was a rapid need for an online in-situ method for nitrate detection to support emerging POU technologies. 

Due to these circumstances, it was necessary to investigate a new method for detecting nitrates, optimised for CDI’s requirements. Spectrophotometric based methods in small batch configuration (cuvette style) became our focus at the onset. A review of all the viable techniques reduced the design to the following common steps that needed to be converted into a viable miniature scale process: i) sample the liquid continuously, ii) pretreatment, iii) nitrate to nitrite reduction, iv) dye addition, v) colour development, vi) spectrophotometric measurement, and vii) dispense the waste.

With the aim of trialling a range of methods that had the potential of functioning as a continuous flow cell system within this design process, reverse engineering attempts were made using commercially available reagent sets from Palintest, and Hach Nitraver5 showing poor colour development. Thus, they were eliminated from further testing 

Subsequent experiments employed the zinc reduction method, which offered a cost-effective means of nitrate concentration through its reduction to nitrite, followed by colorimetric analysis. Even though the zinc method demonstrated promising results, challenges such as sensitivity to reaction time, over-reduction of nitrite to ammonia, and variability in reproducibility limited its effectiveness. Additionally, side reactions and maintenance issues, including zinc oxidation and clogging, hinder its suitability for our continuous process.

Vanadium Chloride reduction method was finally chosen for its efficiency, rapid reaction time, and robustness under varying conditions. This method, combined with UV-VIS spectrophotometric analysis and MATLAB-based data processing, enabled real-time nitrate monitoring with over 93.05% accuracy. Key parameters such as residence time, flow rate, and heat transfer were optimised to enhance system performance. A reaction temperature of 85°C enabled complete reduction of vanadium species within 2 minutes, ensuring safe operation, consistent repeatability, and high precision. To address axial dispersion in flow-through systems, a novel sample-and-hold configuration was implemented, utilising seven parallel reactors with 17-second intervals to achieve discrete temporal resolution and accurate measurement. The system achieved a high-frequency sampling rate of 210 samples per hour (105 samples per CDI cycle), allowing near real-time tracking of nitrate fluctuations during semi-batch CDI operation.

A Stella model was developed to simulate nitrate removal via CDI, providing high resolution insight into nitrate adsorption and desorption dynamics. The model predicted transient nitrate responses that did not far exceed the system’s temporal resolution, which guided the implementation of a discrete sampling interval of 17 seconds. The integration of experimental validation with system simulation underscores the effectiveness of this combined approach in achieving accurate, real-time nitrate monitoring. The outcomes of this research contribute to the advancement of automated water quality analysis systems and offer a scalable, field-deployable solution for mitigating nitrate pollution in drinking water supplies.

text: Rapid online detection of nitrate and quantification of nitrate removal via capacitive deionisation (CDI) Abstract
The increasing nitrate contamination in water poses significant environmental and public health challenges. With the rapid development of Capacitive Deionization (CDI) as a low-cost point-of-use (POU) solution to the problem, there was a rapid need for an online in-situ method for nitrate detection to support emerging POU technologies. 

Due to these circumstances, it was necessary to investigate a new method for detecting nitrates, optimised for CDI’s requirements. Spectrophotometric based methods in small batch configuration (cuvette style) became our focus at the onset. A review of all the viable techniques reduced the design to the following common steps that needed to be converted into a viable miniature scale process: i) sample the liquid continuously, ii) pretreatment, iii) nitrate to nitrite reduction, iv) dye addition, v) colour development, vi) spectrophotometric measurement, and vii) dispense the waste.

With the aim of trialling a range of methods that had the potential of functioning as a continuous flow cell system within this design process, reverse engineering attempts were made using commercially available reagent sets from Palintest, and Hach Nitraver5 showing poor colour development. Thus, they were eliminated from further testing 

Subsequent experiments employed the zinc reduction method, which offered a cost-effective means of nitrate concentration through its reduction to nitrite, followed by colorimetric analysis. Even though the zinc method demonstrated promising results, challenges such as sensitivity to reaction time, over-reduction of nitrite to ammonia, and variability in reproducibility limited its effectiveness. Additionally, side reactions and maintenance issues, including zinc oxidation and clogging, hinder its suitability for our continuous process.

Vanadium Chloride reduction method was finally chosen for its efficiency, rapid reaction time, and robustness under varying conditions. This method, combined with UV-VIS spectrophotometric analysis and MATLAB-based data processing, enabled real-time nitrate monitoring with over 93.05% accuracy. Key parameters such as residence time, flow rate, and heat transfer were optimised to enhance system performance. A reaction temperature of 85°C enabled complete reduction of vanadium species within 2 minutes, ensuring safe operation, consistent repeatability, and high precision. To address axial dispersion in flow-through systems, a novel sample-and-hold configuration was implemented, utilising seven parallel reactors with 17-second intervals to achieve discrete temporal resolution and accurate measurement. The system achieved a high-frequency sampling rate of 210 samples per hour (105 samples per CDI cycle), allowing near real-time tracking of nitrate fluctuations during semi-batch CDI operation.

A Stella model was developed to simulate nitrate removal via CDI, providing high resolution insight into nitrate adsorption and desorption dynamics. The model predicted transient nitrate responses that did not far exceed the system’s temporal resolution, which guided the implementation of a discrete sampling interval of 17 seconds. The integration of experimental validation with system simulation underscores the effectiveness of this combined approach in achieving accurate, real-time nitrate monitoring. The outcomes of this research contribute to the advancement of automated water quality analysis systems and offer a scalable, field-deployable solution for mitigating nitrate pollution in drinking water supplies.

year: 2025-06-10

title: Cultural Theory Made Critical: Towards a Theory of the Indigenous Intellectual

authors: Hireme, Hemi Te Rere

abstract: Despite the fact that Western critical theory has provided us with theories of the power relations that operate within our lives, I argue that the indigenous element is nonetheless understated within these theories. To this end, my thesis is precisely that we must make the "cultural" critical. I argue that various theories of cognitive and moral submissiveness must be supplemented with a theory of submissiveness at the indigenous level in order for issues of latent power to be addressed. This thesis is therefore about developing a theory that for tangata whenua seeks to overcome one of the most debilitating effects of colonial domination - a loss of critical consciousness. I advocate the need for a new type of intellectual - the indigenous intellectual. 
I present my thesis in two parts. Part One examines Western critical theory to understand the processes that contribute to colonial domination. Here, I identify relations and processes of power that have contributed to a continuing assault on tangata whenua cultural continuity and well-being. Of particular significance are Foucault's study of governmentalisation and normalisation and Gramsci's notion of hegemony and the traditional and organic intellectuals. 
Part Two records not only how this understanding is put into action by way of the introduction of a "critical theory" component in programmes at Te Whare Wananga 0 Awanuiarangi over a number of years, but also offers a critical cultural theory in the form of the indigenous intellectual. While it acknowledges the extreme value of Western critical theory in allowing tangata whenua to understand the relations of power and the effects of colonial domination, the programme also identifies the many voids and spaces within Western critical theory that leave unanswered the oppressiveness and hegemony of cultural and ideological colonisation. I conclude my thesis by arguing that, whilst many in leadership positions claim allegiance to Gramsci' s concept of the organic intellectual, their ideological stance is anything but organic. By examining why they do not represent indigenous interests "organically", I argue that a new concept is needed to expose the sham of much of our contemporary "inorganic" politics: that our cultural needs are better served by a concept of the "indigenous" intellectual.

text: Cultural Theory Made Critical: Towards a Theory of the Indigenous Intellectual Despite the fact that Western critical theory has provided us with theories of the power relations that operate within our lives, I argue that the indigenous element is nonetheless understated within these theories. To this end, my thesis is precisely that we must make the "cultural" critical. I argue that various theories of cognitive and moral submissiveness must be supplemented with a theory of submissiveness at the indigenous level in order for issues of latent power to be addressed. This thesis is therefore about developing a theory that for tangata whenua seeks to overcome one of the most debilitating effects of colonial domination - a loss of critical consciousness. I advocate the need for a new type of intellectual - the indigenous intellectual. 
I present my thesis in two parts. Part One examines Western critical theory to understand the processes that contribute to colonial domination. Here, I identify relations and processes of power that have contributed to a continuing assault on tangata whenua cultural continuity and well-being. Of particular significance are Foucault's study of governmentalisation and normalisation and Gramsci's notion of hegemony and the traditional and organic intellectuals. 
Part Two records not only how this understanding is put into action by way of the introduction of a "critical theory" component in programmes at Te Whare Wananga 0 Awanuiarangi over a number of years, but also offers a critical cultural theory in the form of the indigenous intellectual. While it acknowledges the extreme value of Western critical theory in allowing tangata whenua to understand the relations of power and the effects of colonial domination, the programme also identifies the many voids and spaces within Western critical theory that leave unanswered the oppressiveness and hegemony of cultural and ideological colonisation. I conclude my thesis by arguing that, whilst many in leadership positions claim allegiance to Gramsci' s concept of the organic intellectual, their ideological stance is anything but organic. By examining why they do not represent indigenous interests "organically", I argue that a new concept is needed to expose the sham of much of our contemporary "inorganic" politics: that our cultural needs are better served by a concept of the "indigenous" intellectual.

year: 2002