title: Nitrogen transformation in a denitrification layer irrigated with dairy factory effluent

authors: McGill, Alexandra

subjects: denitrification

abstract: Adoption of land-based effluent treatment systems can be constrained by the costs and availability of land. Sufficient land area is needed to ensure nitrate leaching from applied effluent is minimised. One approach to decrease required land area is to enhance N removal by denitrification. Layers of organic matter (100 mm thick) were installed below topsoil of a site irrigated with dairy factory effluent. These “denitrification” layers were tested to determine whether they could decrease nitrate leaching by increasing denitrification. Four plots (10×10 m2 each) were constructed with a denitrification layer installed at 300 mm below the surface, and N losses were measured in leachate using suction cups every 3 weeks for 19 months. N in leachate was compared with 4 control plots. Denitrifying enzyme activity, nitrate concentrations, and carbon availability were measured in samples collected from the denitrification layers. These measurements demonstrated that denitrification occurred in the layer; however, denitrification rates were not sufficiently high to significantly decrease nitrate leaching. Total N leaching was 296 kg N ha⁻¹ from control plots and 238 kg N ha⁻¹ from plots with denitrification layers; a total of 798 kg N ha⁻¹ was applied in effluent. More than 50% of the leached N to 40 cm was as organic N, presumably due to bypass flow. Other studies have demonstrated that thicker denitrification layers (more than 300 mm) can reduce nitrate leaching from small-scale septic tank drainage fields but this study suggests that it is probably not practical to use denitrification layers at larger scales.

text: Nitrogen transformation in a denitrification layer irrigated with dairy factory effluent Adoption of land-based effluent treatment systems can be constrained by the costs and availability of land. Sufficient land area is needed to ensure nitrate leaching from applied effluent is minimised. One approach to decrease required land area is to enhance N removal by denitrification. Layers of organic matter (100 mm thick) were installed below topsoil of a site irrigated with dairy factory effluent. These “denitrification” layers were tested to determine whether they could decrease nitrate leaching by increasing denitrification. Four plots (10×10 m2 each) were constructed with a denitrification layer installed at 300 mm below the surface, and N losses were measured in leachate using suction cups every 3 weeks for 19 months. N in leachate was compared with 4 control plots. Denitrifying enzyme activity, nitrate concentrations, and carbon availability were measured in samples collected from the denitrification layers. These measurements demonstrated that denitrification occurred in the layer; however, denitrification rates were not sufficiently high to significantly decrease nitrate leaching. Total N leaching was 296 kg N ha⁻¹ from control plots and 238 kg N ha⁻¹ from plots with denitrification layers; a total of 798 kg N ha⁻¹ was applied in effluent. More than 50% of the leached N to 40 cm was as organic N, presumably due to bypass flow. Other studies have demonstrated that thicker denitrification layers (more than 300 mm) can reduce nitrate leaching from small-scale septic tank drainage fields but this study suggests that it is probably not practical to use denitrification layers at larger scales.

year: 2008

title: Development of a real-time full-field range imaging system

authors: Jongenelen, Adrian P.P.

subjects: range imaging

abstract: This article describes the development of a full-field range imaging system employing a high frequency amplitude modulated light source and image sensor. Depth images are produced at video frame rates in which each pixel in the image represents distance from the sensor to objects in the scene. 
The various hardware subsystems are described as are the details about the firmware and software implementation for processing the images in real-time. The system is flexible in that precision can be traded off for decreased acquisition time. Results are reported to illustrate this versatility for both high-speed (reduced precision) and high-precision operating modes.

text: Development of a real-time full-field range imaging system This article describes the development of a full-field range imaging system employing a high frequency amplitude modulated light source and image sensor. Depth images are produced at video frame rates in which each pixel in the image represents distance from the sensor to objects in the scene. 
The various hardware subsystems are described as are the details about the firmware and software implementation for processing the images in real-time. The system is flexible in that precision can be traded off for decreased acquisition time. Results are reported to illustrate this versatility for both high-speed (reduced precision) and high-precision operating modes.

year: 2009

title: Creating whanaungatanga: Kaupapa Maori support in the Psychology Department at the University of Waikato

authors: Masters-Awatere, Bridgette

subjects: Maori students

abstract: Attendance at university has been recognized by some as a competitive environment that does not cater for the co-operative philosophy followed by many Maori.  Within the Psychology Department at the University of Waikato there have been efforts since the Departments early days to place emphasis on the Maori cultural experience, but there were few Maori students and no Maori staff back then.  Now, in 2004, the Department has a team of Maori staff and courses with Maori content at both undergraduate and graduate levels.  Yet the environment that the students move in is still competitive. Grades are based on individual assessment through undergraduate level. At graduate level the emphasis on group dynamics comes to the fore.  The availability and accessibility of Maori staff at different levels in a Kaupapa Maori programme provides one of the strategies of support for maori students at Waikato.  This paper discusses the issues around managing, delivering and providing opportunities so that Maori students studying psychology feel supported for the duration of their time at Waikato University.

text: Creating whanaungatanga: Kaupapa Maori support in the Psychology Department at the University of Waikato Attendance at university has been recognized by some as a competitive environment that does not cater for the co-operative philosophy followed by many Maori.  Within the Psychology Department at the University of Waikato there have been efforts since the Departments early days to place emphasis on the Maori cultural experience, but there were few Maori students and no Maori staff back then.  Now, in 2004, the Department has a team of Maori staff and courses with Maori content at both undergraduate and graduate levels.  Yet the environment that the students move in is still competitive. Grades are based on individual assessment through undergraduate level. At graduate level the emphasis on group dynamics comes to the fore.  The availability and accessibility of Maori staff at different levels in a Kaupapa Maori programme provides one of the strategies of support for maori students at Waikato.  This paper discusses the issues around managing, delivering and providing opportunities so that Maori students studying psychology feel supported for the duration of their time at Waikato University.

year: 2004-12