title: Bacteriological control food equipment by cleaning systems

authors: Dunsmore, David George

abstract: This study was undertaken to examine the performance of cleaning systems applied to food equipment. The contribution by the components of those systems to the performance of the total system was determined.
A cleaning simulator was constructed in which test pieces in 4 test cells were subjected to 25 to 35 cycles, each of 12h. Each cycle the test pieces were: soiled for 45 min. in pasteurised milk (at 30°c) dosed with 10⁶ bacteria/ml of Streptococcus faecalis, Escherichia coli or Enterobacter aerogenes; serially treated with the rinses, detergents and sanitizers of the experimental cleaning system; and left for 9.5h intercycle (rest) period. The changes in the soil mass with time on stainless steel, rubber and glass test pieces were determined gravimetrically. The changes in the numbers of the dosed and non-dosed organisms on the surfaces, after components of the cleaning system had been applied, were determined by a swab-recovery/ plate-counting system. The surfaces were also examined by scanning electron microscopy. Four experiments were performed using this technique.
A field experiment examined the performance of 5 cleaning systems over experimental periods of 5 weeks on 15 milking machines. 
The nature of the changes in the performance of the cleaning system over time were determined. Both detergents and sanitizers could, under varying conditions, contribute significantly to the bacteriological performance achieved by the system. A sanitizer applied for the complete intercycle period was more efficient than those applied for short contact-times. A post-wash sanitizer was slightly more efficient than a sanitizer applied before milking. 
The cycle of bacterial deposition onto the equipment surfaces, attachment, depletion by the cleaning system, growth during the intercycle period, and subsequent contamination of the milk at the next milking was studied. All three dose organisms attached actively, and were then largely removed by the cleaning system. Despite there being a large amount of soil on the surfaces of the test pieces, the intercycle conditions (30°c at up to 90% RH for 9.5h) were insufficient for growth. The effect of the amount of soil on the surface on the ability of bacteria to survive the application of a system or system component was examined. The minimum soil levels necessary for an organism to survive a treatment (Total Effect Maximum) and the minimum soil necessary for all organisms to survive a treatment (Zero Effect Minimum) were determined for systems and system components. 
The data was used to discuss the principles to be followed in designing a cleaning system. The principles were applied to the design of a system to clean a milking machine with cold solutions by soak techniques.

text: Bacteriological control food equipment by cleaning systems This study was undertaken to examine the performance of cleaning systems applied to food equipment. The contribution by the components of those systems to the performance of the total system was determined.
A cleaning simulator was constructed in which test pieces in 4 test cells were subjected to 25 to 35 cycles, each of 12h. Each cycle the test pieces were: soiled for 45 min. in pasteurised milk (at 30°c) dosed with 10⁶ bacteria/ml of Streptococcus faecalis, Escherichia coli or Enterobacter aerogenes; serially treated with the rinses, detergents and sanitizers of the experimental cleaning system; and left for 9.5h intercycle (rest) period. The changes in the soil mass with time on stainless steel, rubber and glass test pieces were determined gravimetrically. The changes in the numbers of the dosed and non-dosed organisms on the surfaces, after components of the cleaning system had been applied, were determined by a swab-recovery/ plate-counting system. The surfaces were also examined by scanning electron microscopy. Four experiments were performed using this technique.
A field experiment examined the performance of 5 cleaning systems over experimental periods of 5 weeks on 15 milking machines. 
The nature of the changes in the performance of the cleaning system over time were determined. Both detergents and sanitizers could, under varying conditions, contribute significantly to the bacteriological performance achieved by the system. A sanitizer applied for the complete intercycle period was more efficient than those applied for short contact-times. A post-wash sanitizer was slightly more efficient than a sanitizer applied before milking. 
The cycle of bacterial deposition onto the equipment surfaces, attachment, depletion by the cleaning system, growth during the intercycle period, and subsequent contamination of the milk at the next milking was studied. All three dose organisms attached actively, and were then largely removed by the cleaning system. Despite there being a large amount of soil on the surfaces of the test pieces, the intercycle conditions (30°c at up to 90% RH for 9.5h) were insufficient for growth. The effect of the amount of soil on the surface on the ability of bacteria to survive the application of a system or system component was examined. The minimum soil levels necessary for an organism to survive a treatment (Total Effect Maximum) and the minimum soil necessary for all organisms to survive a treatment (Zero Effect Minimum) were determined for systems and system components. 
The data was used to discuss the principles to be followed in designing a cleaning system. The principles were applied to the design of a system to clean a milking machine with cold solutions by soak techniques.

year: 1978

title: An Investigation into Landing Approach Visual Illusions

authors: Reynolds, Natalie Beth

subjects: aviation

abstract: This experiment was designed to examine aspects of human visual perception during approaches to a runway. The runway width illusion has commonly been reported to contribute to the dangerous tendency of pilots to fly low approaches to runways that are wide and high approaches to runways that are narrow. Attempts to prevent the runway width illusion have not attempted to identify the ideal location for an indicator of altitude. Thus the present experiment examined the effect of varying runway width and manipulated scenes in order to determine whether the runway width illusion was present and where participants were focusing their attention in the scenes. Thirty-two non-pilot participants and 3 pilots took part in the experiment and viewed static and dynamic scenes of runways that were narrow (30.48m), medium (60.96m) or wide (91.44m) at one of three viewing heights low (30.48m), medium (45.72m) or high (60.96m). After viewing scenes, participants were required to estimate their altitude and aim-point. The results of this experiment revealed that participants were fairly inaccurate at estimating altitude and were inclined to overestimate aim-point, however the data also indicated that there was a robust runway width illusion that was present across static and dynamic trials and in both altitude and aim-point data. The standard marking on the runway in an attempt to prevent the runway width illusion was not effective at preventing incorrect altitude estimations but did assist participants to estimate aim-point. It was also found that the objects that participants' most commonly reported using to estimate altitude in the visual scene were located in the lower segment of the scenes.

text: An Investigation into Landing Approach Visual Illusions This experiment was designed to examine aspects of human visual perception during approaches to a runway. The runway width illusion has commonly been reported to contribute to the dangerous tendency of pilots to fly low approaches to runways that are wide and high approaches to runways that are narrow. Attempts to prevent the runway width illusion have not attempted to identify the ideal location for an indicator of altitude. Thus the present experiment examined the effect of varying runway width and manipulated scenes in order to determine whether the runway width illusion was present and where participants were focusing their attention in the scenes. Thirty-two non-pilot participants and 3 pilots took part in the experiment and viewed static and dynamic scenes of runways that were narrow (30.48m), medium (60.96m) or wide (91.44m) at one of three viewing heights low (30.48m), medium (45.72m) or high (60.96m). After viewing scenes, participants were required to estimate their altitude and aim-point. The results of this experiment revealed that participants were fairly inaccurate at estimating altitude and were inclined to overestimate aim-point, however the data also indicated that there was a robust runway width illusion that was present across static and dynamic trials and in both altitude and aim-point data. The standard marking on the runway in an attempt to prevent the runway width illusion was not effective at preventing incorrect altitude estimations but did assist participants to estimate aim-point. It was also found that the objects that participants' most commonly reported using to estimate altitude in the visual scene were located in the lower segment of the scenes.

year: 2007

title: Maori seeking self-determination or Tino Rangatiratanga? A note

authors: Toki, Valmaine

abstract: Dr Nin Tomas wrote a considered and substantial piece entitled “Indigenous Peoples and the Māori: The Right to Self-Determination in International Law - From Woe to Go” for the New Zealand Law Review published in 2008.² In her conclusion she notes two ways in which self-determination has been implemented by the state: first, by “greater tolerance and benevolence along a series of principled guidelines”,³ and, second, as a “peoples-centred, enabling principle that allows Indigenous peoples to re-establish their social, economic and political institutions”.⁴
In 2010, New Zealand reversed its position and supported the United Nations Declaration on the Rights of Indigenous Peoples (the Declaration).5 With this in mind, this short piece revisits the notion of self-determination by examining the differing dynamics of concepts of external and internal self-determination before a short discussion on pluralism and the relationship between tino rangatiratanga and self-determination. In conclusion some thoughts are offered on a potential form of self-determination that could be consistent with the exercise of tino rangatiratanga.

text: Maori seeking self-determination or Tino Rangatiratanga? A note Dr Nin Tomas wrote a considered and substantial piece entitled “Indigenous Peoples and the Māori: The Right to Self-Determination in International Law - From Woe to Go” for the New Zealand Law Review published in 2008.² In her conclusion she notes two ways in which self-determination has been implemented by the state: first, by “greater tolerance and benevolence along a series of principled guidelines”,³ and, second, as a “peoples-centred, enabling principle that allows Indigenous peoples to re-establish their social, economic and political institutions”.⁴
In 2010, New Zealand reversed its position and supported the United Nations Declaration on the Rights of Indigenous Peoples (the Declaration).5 With this in mind, this short piece revisits the notion of self-determination by examining the differing dynamics of concepts of external and internal self-determination before a short discussion on pluralism and the relationship between tino rangatiratanga and self-determination. In conclusion some thoughts are offered on a potential form of self-determination that could be consistent with the exercise of tino rangatiratanga.

year: 2017