title: Lanthanide Luminescence and its Applications in Forensic Science

authors: Parnell, Antony Joseph

subjects: latent

abstract: Lanthanide compounds, specifically those containing europium and terbium can exhibit luminescent properties when combined with ligands that promote this characteristic. Lanthanide luminescence has proven to have an array of useful applications, one of which is the formation of luminescent powders for exposure of latent fingerprints. The aim of this study was to synthesise a novel ligand to support luminescent character in europium and terbium compounds, and then dope these compounds in to talcum powder. This resulting powder would ideally give exposure of latent fingerprints that can then be enhanced, through excitation of the luminescent compounds dispersed in the powder.
A novel (Me)₃CN(CH₂P(O)Ph₂)₂ ligand (p=o) was synthesised, and in turn was used to synthesis a range of Ln(β‐diketonate)₃(p=o) compounds. These compounds were assessed for potential luminescent activity, and doped into talcum powder. These powders were then appraised for their prospective use as latent fingerprint exposing agents. 
Through modification of a published procedure, the (Me)₃CN(CH₂P(O)Ph₂)₂ ligand was synthesised, and characterised by Electrospray Ionisation (ESI) Mass spectrometry, Nuclear Magnetic Resonance (NMR) spectroscopy, Infra‐red (IR) spectroscopy, melting point analysis and elemental analysis. With β‐diketonate ligands acetylacetone (acac) and thenoyltrifluoroacetone (tta), lanthanide metals lanthanum, europium and terbium and the (p=o) ligands a series of novel compounds were synthesised (Ln(β‐diketonate)₃(p=o)). These compounds were characterised by the methods listed above. 
Using the neutral ligands 1,10‐phenanthroline (phen) and 2,2‐bipyridine (bipy), a series of Eu/Tb(acac/tta)₃(phen/bipy) compounds were synthesised and doped into talcum powder, to investigate the effects on particle and structure character of the doped talcum powders. Talcum powder was also sonicated to investigate the effect of this on particle size, along with effect on use as a fingerprinting agent. Laser diffraction and Scanning Electron Microscopy studies informed of a notable decrease in particle size with sonication, and an increase in specific surface area. However the effect of this process on increasing exposure of latent fingerprints was deemed too insignificant to justify the procedure.
The compounds Eu/Tb(acac/tta)₃(phen/bipy), (Eu/Tb(β‐diketonate)₃(p=o) and [H₂NMe₂]₃[Eu/Tb(2,6‐dpa)₃].2H₂O were investigated for luminescent activity. Fluorescence spectroscopy determined the dominant emission wavelengths from 254 nm and 312 nm excitation were at 510 nm and 625 nm respectively. The talcum powders, doped with the luminescent compounds were analysed for luminescent activity. Direct screening with an ultra‐violet (UV) lamp with emission wavelengths of 254 nm and 312 nm informed of the powders with the most intensely observed luminescent emissions. From these results, Eu(tta)₃(p=o), H₂NMe₂]₃[Eu(2,6‐ dpa)₃].2H₂O, Tb(acac)₃(p=o) and H₂NMe₂]₃[Tb(2,6‐dpa)₃].2H₂O were chosen as the most promising candidates for more in‐depth investigation of latent fingerprint exposure potential. Furthermore, it was determined that the novel (Me)₃CN(CH₂P(O)Ph₂)₂ ligand was successful as a neutral ligand for supporting luminescence.
The powders were trialled by several variables, including surface, powder quantity, age of latent print, temperature, and the brush used to determine their effectiveness. Powders were compared to commercial Greenwop and Redwop fingerprint powders, as these were the most similar industrial samples in terms of use. Through trials in the laboratory and the police fingerprinting laboratory, it was determined that the doped talcum powders were inferior to the commercial “wop” samples in terms of latent print definition under UV conditions. However, the talcum powders had several useful applications, specifically the dual effect of exposing prints clearly under UV and non‐UV conditions. It was concluded the best application for the fingerprint powders was on smooth surfaces such as glass, with a gradual application of powder. Small amounts of powder gave more clarity under non‐UV print exposure, but higher quantities of powder were required to get ample luminescent intensity under UV conditions.

text: Lanthanide Luminescence and its Applications in Forensic Science Lanthanide compounds, specifically those containing europium and terbium can exhibit luminescent properties when combined with ligands that promote this characteristic. Lanthanide luminescence has proven to have an array of useful applications, one of which is the formation of luminescent powders for exposure of latent fingerprints. The aim of this study was to synthesise a novel ligand to support luminescent character in europium and terbium compounds, and then dope these compounds in to talcum powder. This resulting powder would ideally give exposure of latent fingerprints that can then be enhanced, through excitation of the luminescent compounds dispersed in the powder.
A novel (Me)₃CN(CH₂P(O)Ph₂)₂ ligand (p=o) was synthesised, and in turn was used to synthesis a range of Ln(β‐diketonate)₃(p=o) compounds. These compounds were assessed for potential luminescent activity, and doped into talcum powder. These powders were then appraised for their prospective use as latent fingerprint exposing agents. 
Through modification of a published procedure, the (Me)₃CN(CH₂P(O)Ph₂)₂ ligand was synthesised, and characterised by Electrospray Ionisation (ESI) Mass spectrometry, Nuclear Magnetic Resonance (NMR) spectroscopy, Infra‐red (IR) spectroscopy, melting point analysis and elemental analysis. With β‐diketonate ligands acetylacetone (acac) and thenoyltrifluoroacetone (tta), lanthanide metals lanthanum, europium and terbium and the (p=o) ligands a series of novel compounds were synthesised (Ln(β‐diketonate)₃(p=o)). These compounds were characterised by the methods listed above. 
Using the neutral ligands 1,10‐phenanthroline (phen) and 2,2‐bipyridine (bipy), a series of Eu/Tb(acac/tta)₃(phen/bipy) compounds were synthesised and doped into talcum powder, to investigate the effects on particle and structure character of the doped talcum powders. Talcum powder was also sonicated to investigate the effect of this on particle size, along with effect on use as a fingerprinting agent. Laser diffraction and Scanning Electron Microscopy studies informed of a notable decrease in particle size with sonication, and an increase in specific surface area. However the effect of this process on increasing exposure of latent fingerprints was deemed too insignificant to justify the procedure.
The compounds Eu/Tb(acac/tta)₃(phen/bipy), (Eu/Tb(β‐diketonate)₃(p=o) and [H₂NMe₂]₃[Eu/Tb(2,6‐dpa)₃].2H₂O were investigated for luminescent activity. Fluorescence spectroscopy determined the dominant emission wavelengths from 254 nm and 312 nm excitation were at 510 nm and 625 nm respectively. The talcum powders, doped with the luminescent compounds were analysed for luminescent activity. Direct screening with an ultra‐violet (UV) lamp with emission wavelengths of 254 nm and 312 nm informed of the powders with the most intensely observed luminescent emissions. From these results, Eu(tta)₃(p=o), H₂NMe₂]₃[Eu(2,6‐ dpa)₃].2H₂O, Tb(acac)₃(p=o) and H₂NMe₂]₃[Tb(2,6‐dpa)₃].2H₂O were chosen as the most promising candidates for more in‐depth investigation of latent fingerprint exposure potential. Furthermore, it was determined that the novel (Me)₃CN(CH₂P(O)Ph₂)₂ ligand was successful as a neutral ligand for supporting luminescence.
The powders were trialled by several variables, including surface, powder quantity, age of latent print, temperature, and the brush used to determine their effectiveness. Powders were compared to commercial Greenwop and Redwop fingerprint powders, as these were the most similar industrial samples in terms of use. Through trials in the laboratory and the police fingerprinting laboratory, it was determined that the doped talcum powders were inferior to the commercial “wop” samples in terms of latent print definition under UV conditions. However, the talcum powders had several useful applications, specifically the dual effect of exposing prints clearly under UV and non‐UV conditions. It was concluded the best application for the fingerprint powders was on smooth surfaces such as glass, with a gradual application of powder. Small amounts of powder gave more clarity under non‐UV print exposure, but higher quantities of powder were required to get ample luminescent intensity under UV conditions.

year: 2011

title: Invasive fish survey of Lake Arapuni by boat electrofishing

authors: Tempero, Grant Wayne

abstract: A boat electrofishing survey of Lake Arapuni was conducted on 2 February 2017 by the University of Waikato to investigate anecdotal reports of koi carp (Cyprinus carpio) presence in the lake. Nine 10-minute electrofishing transects were conducted around the littoral zone of the lake. This resulted in a total distance fished of 3.35 km and a total area fished of 1.34 ha. A total of 100 fish were captured, comprising three species: brown bullhead catfish (Ameiurus nebu/osus), goldfish {Carassius auratus) and rudd {Scardinius erythrophthalmus); in addition, eels (Anguilla sp.) were observed but not captured.
Total captured fish biomass was 14.8 kg {11. 7 kg/ha) with goldfish being the most abundant species (86 individuals), accounting for most of the biomass (86.8%). Rudd were the next most abundant species with nine individuals captured (1.0 kg/ha) followed by catfish (five individuals; 0.4 kg/ha). Rudd and catfish boat electrofishing biomass estimates should be regarded as minimal as capture rates for benthic species (catfish) and juveniles (rudd) are often lower than those of adult pelagic species. The reduced capture efficiency of benthic species is due to their preference for depths beyond the extent of the electrofishing field (approximately 2 m in extent from the anode), in addition benthic species are more likely to be missed by netters due to their reduced visibility. The smaller size (<100 mm FL) of juvenile fish makes them less susceptible to the electric field and therefore less likely to be captured in numbers representative of the community composition.
No koi carp were captured even though the area fished was typical of their preferred habitat. While the presence of koi carp in Lake Arapuni cannot be completely discounted, the survey results indicate that they are either absent from the lake or present in low numbers. Furthermore, the goldfish population was dominated by large adults (>150 mm FL), many of which were highly coloured and had markings similar to those of koi carp. It is likely that these larger coloured goldfish were mistaken for koi carp in previous sightings, especially as adult goldfish form small aggregations similar to those of koi carp. If koi carp are present in Lake Arapuni they are likely to be at biomass levels too low to mount viable control or eradication programmes given the large area and depth of the lake.

text: Invasive fish survey of Lake Arapuni by boat electrofishing A boat electrofishing survey of Lake Arapuni was conducted on 2 February 2017 by the University of Waikato to investigate anecdotal reports of koi carp (Cyprinus carpio) presence in the lake. Nine 10-minute electrofishing transects were conducted around the littoral zone of the lake. This resulted in a total distance fished of 3.35 km and a total area fished of 1.34 ha. A total of 100 fish were captured, comprising three species: brown bullhead catfish (Ameiurus nebu/osus), goldfish {Carassius auratus) and rudd {Scardinius erythrophthalmus); in addition, eels (Anguilla sp.) were observed but not captured.
Total captured fish biomass was 14.8 kg {11. 7 kg/ha) with goldfish being the most abundant species (86 individuals), accounting for most of the biomass (86.8%). Rudd were the next most abundant species with nine individuals captured (1.0 kg/ha) followed by catfish (five individuals; 0.4 kg/ha). Rudd and catfish boat electrofishing biomass estimates should be regarded as minimal as capture rates for benthic species (catfish) and juveniles (rudd) are often lower than those of adult pelagic species. The reduced capture efficiency of benthic species is due to their preference for depths beyond the extent of the electrofishing field (approximately 2 m in extent from the anode), in addition benthic species are more likely to be missed by netters due to their reduced visibility. The smaller size (<100 mm FL) of juvenile fish makes them less susceptible to the electric field and therefore less likely to be captured in numbers representative of the community composition.
No koi carp were captured even though the area fished was typical of their preferred habitat. While the presence of koi carp in Lake Arapuni cannot be completely discounted, the survey results indicate that they are either absent from the lake or present in low numbers. Furthermore, the goldfish population was dominated by large adults (>150 mm FL), many of which were highly coloured and had markings similar to those of koi carp. It is likely that these larger coloured goldfish were mistaken for koi carp in previous sightings, especially as adult goldfish form small aggregations similar to those of koi carp. If koi carp are present in Lake Arapuni they are likely to be at biomass levels too low to mount viable control or eradication programmes given the large area and depth of the lake.

year: 2017

title: Kia whakatōmuri te haere whakamua: ‘I walk backwards into the future with my eyes fixed on my past’

authors: Rameka, Lesley Kay

subjects: Māori

abstract: This whakataukī or ‘proverb’ speaks to Māori perspectives of time, where the past, the present and the future are viewed as intertwined, and life as a continuous cosmic process. Within this continuous cosmic movement, time has no restrictions – it is both past and present. The past is central to and shapes both present and future identity. From this perspective, the individual carries their past into the future. The strength of carrying one’s past into the future is that ancestors are ever present, existing both within the spiritual realm and in the physical, alongside the living as well as within the living. This article explores Māori perspectives of the past and the models and inspiration they offer. In this way, it provides a critique of the practices in early childhood education, highlighting the importance of cultural concepts and practices, and discusses implications for both teaching and academic practice.

text: Kia whakatōmuri te haere whakamua: ‘I walk backwards into the future with my eyes fixed on my past’ This whakataukī or ‘proverb’ speaks to Māori perspectives of time, where the past, the present and the future are viewed as intertwined, and life as a continuous cosmic process. Within this continuous cosmic movement, time has no restrictions – it is both past and present. The past is central to and shapes both present and future identity. From this perspective, the individual carries their past into the future. The strength of carrying one’s past into the future is that ancestors are ever present, existing both within the spiritual realm and in the physical, alongside the living as well as within the living. This article explores Māori perspectives of the past and the models and inspiration they offer. In this way, it provides a critique of the practices in early childhood education, highlighting the importance of cultural concepts and practices, and discusses implications for both teaching and academic practice.

year: 2017