title: Introduction

authors: Daniel, Roy M.

subjects: biology

abstract: It is generally taken for granted that water is essential for life. Looking for water on Mars has been a preoccupation for decades, and there are an infinite number of meetings on the general topic of ‘water in biology’. Yet these rarely ask precisely why water is important. And if we cannot answer that question, then perhaps it might be replaced by some other medium in some other life form that can still metabolize and reproduce. In fact, there is recent evidence that the molecular–level requirements for water may have been overstated. Our Discussion Meeting aimed to take a constructively sceptical view, encouraging diversity of attitude by bringing together interested scientists from a range of disciplines.

text: Introduction It is generally taken for granted that water is essential for life. Looking for water on Mars has been a preoccupation for decades, and there are an infinite number of meetings on the general topic of ‘water in biology’. Yet these rarely ask precisely why water is important. And if we cannot answer that question, then perhaps it might be replaced by some other medium in some other life form that can still metabolize and reproduce. In fact, there is recent evidence that the molecular–level requirements for water may have been overstated. Our Discussion Meeting aimed to take a constructively sceptical view, encouraging diversity of attitude by bringing together interested scientists from a range of disciplines.

year: 2004

title: Calcium phosphate precipitation from whey permeate

authors: Panova, Natalia N.

abstract: Currently the New Zealand Dairy Industry manufactures a very successful milk calcium product known as ALAMINTM by the precipitation of calcium phosphates (CaP) from various heated whey permeate streams. The main scientific objective of the study described in this thesis was to seek a detailed insight into the fundamental chemistry of the calcium phosphate precipitation process from whey permeates. 
To achieve this scientific objective, the project involved the use of a combination of the theoretical, computer-based speciation calculations, experimental bench-scale calcium phosphate precipitation and application of a large suite of chemical, spectroscopic and microscopic instrumental techniques for analysing the as received whey permeates and commercial ALAMINTM samples, as well as products of bench-scale precipitation reactions from whey permeate and laboratory-prepared solutions modelling whey permeate. An extensive literature search of calcium phosphate precipitation was also carried out. 
Equilibrium Speciation Calculations which predicted precipitation and ion speciations as a function of pH in a complex ionic medium modelling various whey permeate media were used to investigate the influence of several components, i.e. lactate, citrate, sulphate,Mg2+ and Ca:P molar ratio on the extent of precipitation of calcium phosphate solids in the system. The ion speciation program also modelled the effect of seasonal variations in the whey permeate by varying the concentrations of certain components while keeping others constant. In general, the fundamental component influencing yield of calcium phosphate solids in the permeate was found to be the free Ca2+ ion, the concentration of which was sensitive to pH, citrate, lactate, and sulfate concentration as well as Ca:P molar ratio. 
To provide an experimental dimension to these ion speciation studies, a simulated lactic whey ultrafiltrate (SLWUF) buffer which mimicked lactic whey permeate was developed and its precipitation chemistry studied under pH-stat control at pH 6.8 and 25°C. In conjunction with the pH-stat studies, Ca ISE studies were also undertaken to provide additional scientific data on the systems. In general, the experimental work effectively confirmed most of the trends predicted by the ion speciation calculations with regard to the effects on free calcium ion by other components in the simulated buffer. The most important finding on the chemistry of calcium phosphate precipitation from the simulated lactic whey ultrafiltrate buffer was that the precipitation product proceeds via the well documented phase transformation process from an initially amorphous structurally illdefined solid through to the final microcrystalline non-stoichiometric hydroxyapatite. 
Bench-scale precipitation work which incorporated laser light scattering analysis, Ca ISE, FTIR, TEM and ICP-OES/AAS analysis executed on the actual whey permeates effectively proved that calcium phosphate precipitation from the (heated) whey permeate exhibited a similar phase transformation chemistry to that observed with the simulated lactic whey ultrafiltrate (SLWUF) buffer. Agitation rate data and laser light scattering of precipitation from lactic whey permeates coupled with a Log-Normal distribution analysis of the Malvern (Mastersizer) particle size data revealed an increase of aggregation with time and with increases in agitation rate. The Log-Normal analysis suggested that 2-3 distinct particle populations were present throughout the precipitation reaction. Other characterisation work on the commercial ALAMIN™ solids proved that it was a poorly crystalline insoluble non-stoichiometric hydroxyapatite material which co-deposits with a small amount of citrate and protein. This agrees with the precipitation work conducted on precipitates from SLWUF buffers which also show co-deposition with citrate. An additional finding was that lactic whey permeates exhibited less buffering capacity than sulfuric acid whey permeates due to the presence of higher concentrations of citrate in the latter. Concerns about inclusions of calcium sulfate solid phases in the commercial sulfuric acid whey-derived ALAMIN™ were found to be unnecessary due to the experimental confirmation that these phases were not present to any great extent in the final product, a fact backed up by theoretical speciation calculations and ICP-OES analysis. 
In general, this study illustrates the successful application of both theoretical speciation calculations and experimental work to make sense of the chemistry occurring in a naturally complex system which is potentially of great value to the New Zealand Dairy Industry.

text: Calcium phosphate precipitation from whey permeate Currently the New Zealand Dairy Industry manufactures a very successful milk calcium product known as ALAMINTM by the precipitation of calcium phosphates (CaP) from various heated whey permeate streams. The main scientific objective of the study described in this thesis was to seek a detailed insight into the fundamental chemistry of the calcium phosphate precipitation process from whey permeates. 
To achieve this scientific objective, the project involved the use of a combination of the theoretical, computer-based speciation calculations, experimental bench-scale calcium phosphate precipitation and application of a large suite of chemical, spectroscopic and microscopic instrumental techniques for analysing the as received whey permeates and commercial ALAMINTM samples, as well as products of bench-scale precipitation reactions from whey permeate and laboratory-prepared solutions modelling whey permeate. An extensive literature search of calcium phosphate precipitation was also carried out. 
Equilibrium Speciation Calculations which predicted precipitation and ion speciations as a function of pH in a complex ionic medium modelling various whey permeate media were used to investigate the influence of several components, i.e. lactate, citrate, sulphate,Mg2+ and Ca:P molar ratio on the extent of precipitation of calcium phosphate solids in the system. The ion speciation program also modelled the effect of seasonal variations in the whey permeate by varying the concentrations of certain components while keeping others constant. In general, the fundamental component influencing yield of calcium phosphate solids in the permeate was found to be the free Ca2+ ion, the concentration of which was sensitive to pH, citrate, lactate, and sulfate concentration as well as Ca:P molar ratio. 
To provide an experimental dimension to these ion speciation studies, a simulated lactic whey ultrafiltrate (SLWUF) buffer which mimicked lactic whey permeate was developed and its precipitation chemistry studied under pH-stat control at pH 6.8 and 25°C. In conjunction with the pH-stat studies, Ca ISE studies were also undertaken to provide additional scientific data on the systems. In general, the experimental work effectively confirmed most of the trends predicted by the ion speciation calculations with regard to the effects on free calcium ion by other components in the simulated buffer. The most important finding on the chemistry of calcium phosphate precipitation from the simulated lactic whey ultrafiltrate buffer was that the precipitation product proceeds via the well documented phase transformation process from an initially amorphous structurally illdefined solid through to the final microcrystalline non-stoichiometric hydroxyapatite. 
Bench-scale precipitation work which incorporated laser light scattering analysis, Ca ISE, FTIR, TEM and ICP-OES/AAS analysis executed on the actual whey permeates effectively proved that calcium phosphate precipitation from the (heated) whey permeate exhibited a similar phase transformation chemistry to that observed with the simulated lactic whey ultrafiltrate (SLWUF) buffer. Agitation rate data and laser light scattering of precipitation from lactic whey permeates coupled with a Log-Normal distribution analysis of the Malvern (Mastersizer) particle size data revealed an increase of aggregation with time and with increases in agitation rate. The Log-Normal analysis suggested that 2-3 distinct particle populations were present throughout the precipitation reaction. Other characterisation work on the commercial ALAMIN™ solids proved that it was a poorly crystalline insoluble non-stoichiometric hydroxyapatite material which co-deposits with a small amount of citrate and protein. This agrees with the precipitation work conducted on precipitates from SLWUF buffers which also show co-deposition with citrate. An additional finding was that lactic whey permeates exhibited less buffering capacity than sulfuric acid whey permeates due to the presence of higher concentrations of citrate in the latter. Concerns about inclusions of calcium sulfate solid phases in the commercial sulfuric acid whey-derived ALAMIN™ were found to be unnecessary due to the experimental confirmation that these phases were not present to any great extent in the final product, a fact backed up by theoretical speciation calculations and ICP-OES analysis. 
In general, this study illustrates the successful application of both theoretical speciation calculations and experimental work to make sense of the chemistry occurring in a naturally complex system which is potentially of great value to the New Zealand Dairy Industry.

year: 2001

title: A New Technique for Measuring Runup Variation Using Sub-Aerial Video Imagery

authors: Salmon, Summer Anne

subjects: Wave Runup

abstract: Video monitoring of beaches is becoming the preferred method for observing changes to nearshore morphology. Consequently this work investigates a new technique for predicting the probability of inundation that is based on measuring runup variation using video. Runup is defined as the water-level elevation maxima on the foreshore relative to the still water level and the waterline is defined as the position where the MWL intersects the beach face. Tairua, and Pauanui Beaches, on the north east coast of the North Island of New Zealand, were used as the field site in this study and represent two very different beaches with the same incoming wave and meteorological conditions. Tairua is most frequently in an intermediate beach state, whereas Pauanui is usually flatter in nature.

In order to rectify runup observations, an estimate of the runup elevation was needed (Z). This was estimated by measuring the variation of the waterline over a tidal cycle from time-averaged video images during a storm event and provided beach morphology statistics (i.e. beach slope (α) and beach intercept (b)) used in the rectification process where Z=aX+b. The maximum swash excursions were digitized from time-stacks, and rectified to provide run-up timeseries with duration 20 minutes. Field calibrations revealed a videoed waterline that was seaward of the surveyed waterline. Quantification of this error gave a vertical offset of 0.33m at Tairua and 0.25m at Pauanui. 

At Tairua, incident wave energy was dominant in the swash zone, and the runup distributions followed a Rayleigh distribution. At Pauanui, the flatter beach, the runup distributions were approximately bimodal due to the dominance of infragravity energy in the swash signal. The slope of the beach was a major control on the runup elevation; runup at Pauanui was directly affected by the deepwater wave height and the tide, while at Tairua there was no correlation. Overall, the results of the study indicate realistic runup measurements, over a wide range of time scales and, importantly, during storm events. However, comparisons of videoed runup and empirical runup formulae revealed larger deviations as the beach steepness increased. Furthur tests need to be carried out to see if this is a limitation of this technique, used to measure runup. The runup statistics are consistently higher at Tairua and suggests that swash runs up higher on steeper beaches. However, because of the characteristics of flatter beaches (such as high water tables and low drainage efficiencies) the impact of extreme runup elevations on such beaches are more critical in regards to erosion and/ or inundation.

The coastal environment is of great importance to Māori. Damage to the coast and coastal waahi tapu (places of spiritual importance) caused by erosion and inundation, adversely affects the spiritual and cultural well-being of Māori. For this reason, a chapter was dedicated to investigating the practices used by Māori to protect and preserve the coasts in accordance with tikanga Māori (Māori protocols). Mimicking nature was and still is a practice used by Māori to restore the beaches after erosive events, and includes replanting native dune plants and using natural materials on the beaches to stabilize the dunes. Tapu and rahui (the power and influence of the gods) were imposed on communities to prohibit and prevent people from free access to either food resources or to a particular place, in order to protect people and/ or resources. Interpretations of Māori oral histories provide insights into past local hazards and inform about the safety and viability of certain activities within an area. Environmental indicators were used to identify and forecast extreme weather conditions locally.  Māori knowledge of past hazards, and the coastal environment as a whole, is a valuable resource and provides a unique source of expertise that can contribute to current coastal hazards management plans in New Zealand and provide insights about the areas that may again be impacted by natural hazards.

text: A New Technique for Measuring Runup Variation Using Sub-Aerial Video Imagery Video monitoring of beaches is becoming the preferred method for observing changes to nearshore morphology. Consequently this work investigates a new technique for predicting the probability of inundation that is based on measuring runup variation using video. Runup is defined as the water-level elevation maxima on the foreshore relative to the still water level and the waterline is defined as the position where the MWL intersects the beach face. Tairua, and Pauanui Beaches, on the north east coast of the North Island of New Zealand, were used as the field site in this study and represent two very different beaches with the same incoming wave and meteorological conditions. Tairua is most frequently in an intermediate beach state, whereas Pauanui is usually flatter in nature.

In order to rectify runup observations, an estimate of the runup elevation was needed (Z). This was estimated by measuring the variation of the waterline over a tidal cycle from time-averaged video images during a storm event and provided beach morphology statistics (i.e. beach slope (α) and beach intercept (b)) used in the rectification process where Z=aX+b. The maximum swash excursions were digitized from time-stacks, and rectified to provide run-up timeseries with duration 20 minutes. Field calibrations revealed a videoed waterline that was seaward of the surveyed waterline. Quantification of this error gave a vertical offset of 0.33m at Tairua and 0.25m at Pauanui. 

At Tairua, incident wave energy was dominant in the swash zone, and the runup distributions followed a Rayleigh distribution. At Pauanui, the flatter beach, the runup distributions were approximately bimodal due to the dominance of infragravity energy in the swash signal. The slope of the beach was a major control on the runup elevation; runup at Pauanui was directly affected by the deepwater wave height and the tide, while at Tairua there was no correlation. Overall, the results of the study indicate realistic runup measurements, over a wide range of time scales and, importantly, during storm events. However, comparisons of videoed runup and empirical runup formulae revealed larger deviations as the beach steepness increased. Furthur tests need to be carried out to see if this is a limitation of this technique, used to measure runup. The runup statistics are consistently higher at Tairua and suggests that swash runs up higher on steeper beaches. However, because of the characteristics of flatter beaches (such as high water tables and low drainage efficiencies) the impact of extreme runup elevations on such beaches are more critical in regards to erosion and/ or inundation.

The coastal environment is of great importance to Māori. Damage to the coast and coastal waahi tapu (places of spiritual importance) caused by erosion and inundation, adversely affects the spiritual and cultural well-being of Māori. For this reason, a chapter was dedicated to investigating the practices used by Māori to protect and preserve the coasts in accordance with tikanga Māori (Māori protocols). Mimicking nature was and still is a practice used by Māori to restore the beaches after erosive events, and includes replanting native dune plants and using natural materials on the beaches to stabilize the dunes. Tapu and rahui (the power and influence of the gods) were imposed on communities to prohibit and prevent people from free access to either food resources or to a particular place, in order to protect people and/ or resources. Interpretations of Māori oral histories provide insights into past local hazards and inform about the safety and viability of certain activities within an area. Environmental indicators were used to identify and forecast extreme weather conditions locally.  Māori knowledge of past hazards, and the coastal environment as a whole, is a valuable resource and provides a unique source of expertise that can contribute to current coastal hazards management plans in New Zealand and provide insights about the areas that may again be impacted by natural hazards.

year: 2008