title: Preparation, characterisation, and reaction studies of Group IV-transition metal compounds

authors: Graham, Bruce W. L.

abstract: The compounds germylpentacarbonylmanganese, methylgermylpentacarbonylmanganese, and methylgermyltetracarbonylcobalt have been prepared by alkali-halide elimination reactions between the appropriate germyl halides and metal carbonyl anions. The two methyl derivatives were characterised by vibrational and nmr spectroscopy and mass spectrometry, with assignments being proposed for most of the observed features of the spectra. 
Some reactions of H₃GeMn(CO)₅ and MeGeH₂Mn(CO)₅ were investigated. Reagents used included the halogens, hydrogen halides, group III and group IV-halides, mercuric halides, phosphorus trihalides, triarylphosphines, and ethylene. The reaction of MeGeH₂Co(CO)₄ with mercuric chloride was also investigated, as were a number of related reactions of MeGeH₃ and the methylgermyl halides. Most of the reactions were studied by nmr spectroscopy, and in some cases products were further characterised by infrared spectroscopy.
The reactions of MeGeH₃ and MeGeH₂Co(CO)₄ with Co₂(CO)₈ were investigated and in both cases the compound MeGeCo₃(CO)₁₁ was isolated as a major product. Some exchange reactions of MeGeH₂Co(CO)₄ and (H₃Ge)₂Fe(CO)₄ with Mn(CO)₅⁻ were also investigated as a new synthetic route to group IV-transition metal compounds.
The identification of the various reaction products is reported and discussed, and the reactions of group IV-transition metal compounds are reviewed.

text: Preparation, characterisation, and reaction studies of Group IV-transition metal compounds The compounds germylpentacarbonylmanganese, methylgermylpentacarbonylmanganese, and methylgermyltetracarbonylcobalt have been prepared by alkali-halide elimination reactions between the appropriate germyl halides and metal carbonyl anions. The two methyl derivatives were characterised by vibrational and nmr spectroscopy and mass spectrometry, with assignments being proposed for most of the observed features of the spectra. 
Some reactions of H₃GeMn(CO)₅ and MeGeH₂Mn(CO)₅ were investigated. Reagents used included the halogens, hydrogen halides, group III and group IV-halides, mercuric halides, phosphorus trihalides, triarylphosphines, and ethylene. The reaction of MeGeH₂Co(CO)₄ with mercuric chloride was also investigated, as were a number of related reactions of MeGeH₃ and the methylgermyl halides. Most of the reactions were studied by nmr spectroscopy, and in some cases products were further characterised by infrared spectroscopy.
The reactions of MeGeH₃ and MeGeH₂Co(CO)₄ with Co₂(CO)₈ were investigated and in both cases the compound MeGeCo₃(CO)₁₁ was isolated as a major product. Some exchange reactions of MeGeH₂Co(CO)₄ and (H₃Ge)₂Fe(CO)₄ with Mn(CO)₅⁻ were also investigated as a new synthetic route to group IV-transition metal compounds.
The identification of the various reaction products is reported and discussed, and the reactions of group IV-transition metal compounds are reviewed.

year: 1973

title: Modelling volcanic tsunamis

authors: Prasetya, Gegar Sapta

subjects: tsunamis

abstract: Tsunamis generated by volcanic eruptions have caused about 25% of all deaths associated with volcano activity. The 1883 Krakatau eruption is one example of a fairly recent eruption that produced large tsunamis (-35 m) which caused a high death toll. Concern has also been raised by the potential tsunami generation of the Auckland Volcanic Field, and the impact of such events on the Auckland Region.
Although the generation of tsunamis by volcanic eruptions is a major hazard, the processes of tsunami generation are poorly understood. A review of volcanic tsunamis identified 10 main mechanisms. Four of these - caldera collapse, debris avalanches, submarine explosions, and pyroclastic flows - have been suggested as the mechanisms producing the largest tsunamis. All four mechanisms have also been suggested as being responsible for the tsunamis produced by the Krakatau eruption.
A combination of physical and numerical modelling was used to develop predictive tools to be applied to volcanoes in Indonesia and New Zealand. The physical modelling involved two main investigations:
• A 3 dimensional scale model of the Straits of Sunda and Krakatau. This examined the nature of tsunamis produced by caldera collapse, submarine explosions, and water displacement by debris avalanches and pyroclastic flows.
• A series of 2 dimensional simulations of the entrance of pyroclastic flows into the sea. A finite element numerical model was applied to the simulation of pyroclastic flow, maar formation and submarine explosion generation of tsunamis within the Auckland Volcanic Field.
The physical and numerical model results indicate that large scale pyroclastic flows are probably the cause of the main 1883 Krakatau tsunamis. A tsunami wave can easily be generated by gravity flows entering the water, regardless of the slope. The wave properties depend on the relative densities of the flow and the receiving body, and the velocity of the flow. The angle of entry of the flow into the water determines the deposition pattern of sediment. The formation of the Calmeyers and Steers shallow area on Krakatau event 1883 was reproduced by the pyroclastic experiments using coarse sand and mud with steep entry angle ~ 60°). The more dilute upper component of the pyroclastic flow that traveled along the sea surface for up to 45 km and killed more than 1000 people at Katimbang, Sumatera Island can also be explained. The experiments showed that less dense material from the pyroclastic flow propagates near the water surface. This is even more likely if the material is hot and gas-rich.
Physical and numerical model results showed that a single explosion cannot produce a high wave. If a super violent explosion did occur during the Krakatau event, then the water waves (tsunamis) that caused the devastating effect on the surrounding island coastal land were not caused by the direct transfer of explosive forces. Instead a sequence of one or more pyroclastic flows, or collapsing column in and around the Krakatau complex are the most likely mechanism causing the largest tsunami.
Numerical modelling of the Auckland Volcanic Field examined 4 scenarios:
• A series of submarine explosion;
• Pyroclastic flows from Rangitoto Island;
• Pyroclastic flows from Browns (Motukorea) Island;
• Submarine explosion within the Tamaki Estuary.
The first 3 scenarios produced regional effects, while the last was purely local event.
It was also found that the efficiency of the submarine explosion mechanism was increased by using a sequence of smaller explosions, instead of one large explosion. However the timing between explosions was found to be critical; if the explosions are too close together or too far apart, the efficiency decreases. It is considered that the optimal timing will vary with water depth and explosive yield.
The numerical modelling showed that volcanic tsunamis are not a major threat to Auckland. However under suitable conditions a volcanic eruption could produce moderately large tsunamis that generate strong currents.

text: Modelling volcanic tsunamis Tsunamis generated by volcanic eruptions have caused about 25% of all deaths associated with volcano activity. The 1883 Krakatau eruption is one example of a fairly recent eruption that produced large tsunamis (-35 m) which caused a high death toll. Concern has also been raised by the potential tsunami generation of the Auckland Volcanic Field, and the impact of such events on the Auckland Region.
Although the generation of tsunamis by volcanic eruptions is a major hazard, the processes of tsunami generation are poorly understood. A review of volcanic tsunamis identified 10 main mechanisms. Four of these - caldera collapse, debris avalanches, submarine explosions, and pyroclastic flows - have been suggested as the mechanisms producing the largest tsunamis. All four mechanisms have also been suggested as being responsible for the tsunamis produced by the Krakatau eruption.
A combination of physical and numerical modelling was used to develop predictive tools to be applied to volcanoes in Indonesia and New Zealand. The physical modelling involved two main investigations:
• A 3 dimensional scale model of the Straits of Sunda and Krakatau. This examined the nature of tsunamis produced by caldera collapse, submarine explosions, and water displacement by debris avalanches and pyroclastic flows.
• A series of 2 dimensional simulations of the entrance of pyroclastic flows into the sea. A finite element numerical model was applied to the simulation of pyroclastic flow, maar formation and submarine explosion generation of tsunamis within the Auckland Volcanic Field.
The physical and numerical model results indicate that large scale pyroclastic flows are probably the cause of the main 1883 Krakatau tsunamis. A tsunami wave can easily be generated by gravity flows entering the water, regardless of the slope. The wave properties depend on the relative densities of the flow and the receiving body, and the velocity of the flow. The angle of entry of the flow into the water determines the deposition pattern of sediment. The formation of the Calmeyers and Steers shallow area on Krakatau event 1883 was reproduced by the pyroclastic experiments using coarse sand and mud with steep entry angle ~ 60°). The more dilute upper component of the pyroclastic flow that traveled along the sea surface for up to 45 km and killed more than 1000 people at Katimbang, Sumatera Island can also be explained. The experiments showed that less dense material from the pyroclastic flow propagates near the water surface. This is even more likely if the material is hot and gas-rich.
Physical and numerical model results showed that a single explosion cannot produce a high wave. If a super violent explosion did occur during the Krakatau event, then the water waves (tsunamis) that caused the devastating effect on the surrounding island coastal land were not caused by the direct transfer of explosive forces. Instead a sequence of one or more pyroclastic flows, or collapsing column in and around the Krakatau complex are the most likely mechanism causing the largest tsunami.
Numerical modelling of the Auckland Volcanic Field examined 4 scenarios:
• A series of submarine explosion;
• Pyroclastic flows from Rangitoto Island;
• Pyroclastic flows from Browns (Motukorea) Island;
• Submarine explosion within the Tamaki Estuary.
The first 3 scenarios produced regional effects, while the last was purely local event.
It was also found that the efficiency of the submarine explosion mechanism was increased by using a sequence of smaller explosions, instead of one large explosion. However the timing between explosions was found to be critical; if the explosions are too close together or too far apart, the efficiency decreases. It is considered that the optimal timing will vary with water depth and explosive yield.
The numerical modelling showed that volcanic tsunamis are not a major threat to Auckland. However under suitable conditions a volcanic eruption could produce moderately large tsunamis that generate strong currents.

year: 1998

title: An evaluation of Te Rau Puawai workforce 100: Academic mentor's perspectives

authors: Nikora, Linda Waimarie

subjects: Maori students

abstract: To evaluate the Te Rau Puawai programme, the Ministry of Health commissioned the
Maori and Psychology Research Unit of the University of Waikato in July 2001. The
overall aim of the evaluation was to provide the Ministry with a clearer understanding
of the programme including: the perceived critical success factors, the barriers if any
regarding Te Rau Puawai, the impact of the programme, the extent to which the
programme may be transferable, gaps in the programme, and suggested
improvements.
As an integral component of the Te Rau Puawai programme and as a specialised
source of support, academic mentors were identified as an important group to receive
comment from. This report documents the evaluative exchange that occurred by way
of email questionnaire, that we had with 18 out of 46 academic mentors of Te Rau
Puawai bursars in the College of Humanities and Social Sciences responded to our
questionnaire.

text: An evaluation of Te Rau Puawai workforce 100: Academic mentor's perspectives To evaluate the Te Rau Puawai programme, the Ministry of Health commissioned the
Maori and Psychology Research Unit of the University of Waikato in July 2001. The
overall aim of the evaluation was to provide the Ministry with a clearer understanding
of the programme including: the perceived critical success factors, the barriers if any
regarding Te Rau Puawai, the impact of the programme, the extent to which the
programme may be transferable, gaps in the programme, and suggested
improvements.
As an integral component of the Te Rau Puawai programme and as a specialised
source of support, academic mentors were identified as an important group to receive
comment from. This report documents the evaluative exchange that occurred by way
of email questionnaire, that we had with 18 out of 46 academic mentors of Te Rau
Puawai bursars in the College of Humanities and Social Sciences responded to our
questionnaire.

year: 2002-05-01