Diffusion and convection of gaseous and fine particulate from a chimney

Particle dispersion from a high chimney is considered and an expression for the subsequent concentration of the particulate deposited on the ground is derived. We consider the general case wherein the effects of both diffusion and convection on the steady state ground concentration of particulate are incorporated. Two key parameters emerge from this analysis: the ratio of diffusion to convection and the nondimensionalised surface mass transfer rate. We also solve the inverse problem of recovering these two parameters given the boundary concentration profile and provide an estimate of the concentration flux above the chimney stack

The formation of mixed germanium–cobalt carbonyl clusters: an electrospray mass spectrometric study, and the structure of a high-nuclearity [Ge₂Co₁₀(CO)₂₄]²⁻ anion

The reaction of [µ₄-Ge{Co₂(CO)₇}₂] with [Co(CO)₄]⁻ has been monitored by electrospray mass spectrometry to detect the cluster anions generated. Conditions giving known mixed Ge–Co carbonyl clusters were established, and a new high nuclearity cluster anion, [Ge₂Co₁₀(CO)₂₄]²⁻ was detected. Conditions for its formation were optimised and it was subsequently isolated as its [Et₄N]⁺ salt and characterised by single-crystal X-ray crystallography. The Ge₂Co₁₀ cluster core has a novel geometry with the two germanium atoms in semi-encapsulated positions, forming seven formal Ge–Co bonds. There are also eighteen formal Co–Co bonds. Corresponding reactions of [µ₄-Si{Co₂(CO)₇}₂] with [Co(CO)₄]⁻ were also investigated

Geology of the Qaqqanituaq Area and mafic and ultramafic geochemistry of the Hall Peninsula, Baffin Island, Nunavut

Recent regional bedrock mapping carried out on the Hall Peninsula, Baffin Island, Nunavut has revealed previously unknown rock units, structural relationships and metamorphic conditions achieved. Mafic and ultramafic rocks occur primarily intercalated with metasedimentary rocks in the east-central region of the Hall Peninsula. Focused mapping was carried out in the Quaqqanituaq Area (QA), now the type locality for metasedimentary-mafic/ultramafic occurrences on the Hall Peninsula. The QA records an east-west compression event, D1, which produced in the dominant regional S1 fabric and tight, nearly isoclinal F1 folds. The QA also records a north-south compression event, D3 (regional D2 event not observed in QA) resulting in an S3 crenulation cleavage and open F3 folds. U-Pb detrital zircon geochronology and U-Pb geochronology of a cross-cutting monzogranite dyke bracket sediment accumulation and mafic/ultramafic intrusion/extrusion between 2.13 and 1.87 Ga and place a maximum age on D1 at 1.87 Ga. Garnet – biotite – K-feldspar – ± sillimanite mineral assemblages observed in QA pelites indicate that upper amphibolite facies metamorphic conditions were reached. This observation is empirically confirmed by the implementation of winTWQ software which indicates that the peak pressure and temperature conditions reached in the QA were 4.8±2.1 kbars and 645±50°C. Whole-rock major and trace element geochemical data was obtained for 75 mafic and ultramafic samples from all regions of the Hall Peninsula including 20 from the QA. Mafic samples were classified on the basis of N-MORB normalized trace element geochemistry as being alkaline (La/Sm ~ 4.9; Gd/Yb ~ 2.7), calc-alkaline (La/Sm ~ 4.3; Gd/Yb ~ 2.4), tholeiitic (La/Sm ~ 2.1; Gd/Yb ~ 1.1), or transitional (La/Sm ~ 2.7; Gd/Yb ~ 1.6). A negative Nb anomaly, which is on average 5.4 times lower with respect to Th and Ce is observed in all mafic samples with the exception of alkaline mafic rocks. On the basis of their geochemical profiles and comparative study of adjacent terrains, the mafic rocks are concluded result from partial melting a subduction modified mantle source during plume-initiated rifting of the North Atlantic Craton

Reconstruction of the spatial dependency of dielectric and geometrical properties of adhesively bonded structures

An inverse problem motivated by the nondestructive testing of adhesively bonded structures used in the aircraft industry is studied. Using transmission line theory, a model is developed which, when supplied with electrical and geometrical parameters, accurately predicts the reflection coefficient associated with such structures. Particular attention is paid to modelling the connection between the structures and the equipment used to measure the reflection coefficient. The inverse problem is then studied and an optimization approach employed to recover these electrical and geometrical parameters from experimentally obtained data. In particular the approach focuses on the recovery of spatially varying geometrical parameters as this is paramount to the successful reconstruction of electrical parameters. Reconstructions of structure geometry using this method are found to be in close agreement with experimental observations

The Impact of Welfare Colonialism on Inuit Responses to Climate Change in Qikiqtani, Canada

Climate instability in the Arctic poses large challenges for Inuit who live there and whilst climate vulnerability research is effective on many levels, this approach has been critiqued for overlooking the impacts of colonialism. Therefore, a niche exists that investigates how the ongoing issues of welfare colonialism, which refers to the problematic centre-periphery interactions between the state and indigenous groups from the 1950s, affect the ability of Inuit to respond to climate change. To do this, the ‘vulnerability’ term, currently widely used in Canadian Arctic research, was re-framed to ‘community wellness’ in order to offer a more open-ended analysis. Through consulting literature, this study asks: How do the legacies of welfare colonialism in Qikiqtani, Canada affect community wellness in Igloolik and Grise Fiord? It was found that the main factors of community wellness, which include kinship, culture, community, mobility and subsistence, were all adversely impacted by aspects of welfare colonialism such as resettlement and the removal of Inuit from their homes for education and medical treatment. It is suggested that Inuit in Qikiqtani today are less able to respond to challenges due to these legacies of welfare colonialism. Analysis of literature indicates that there is significant overlap between the ongoing impacts of colonialism and non-climatic factors of climate vulnerability in the Canadian Arctic. Because of this, welfare colonialism is argued to affect the human dimensions of climate change in Qikiqtani as it increases the vulnerability of Inuit. It is also noted that the centreperiphery aspects of welfare colonialism can be also be partially seen in the research that is conducted in the Canadian Arctic today and that there is opportunity for future studies to explore ways in which aspects of this research could be decolonised

The Impact of Future CO2 Emission Reduction Targets on U.S. Electric Sector Water Use

The U.S. electric sector's reliance on water makes it vulnerable to the impacts of climate change on water resources. Here we analyze how constraints on U.S. energy system carbon dioxide (CO2) emissions could affect water withdrawal and consumption in the U.S. electric sector through 2055. We use simulations of the EPA's U.S. 9-region (EPAUS9r) MARKAL least-cost optimization energy systems model with updated water use factors for electricity generating technologies. Model results suggest CO2 constraints could force the retirement of old power plants and drive increased use of low water-use renewable and nuclear power as well as natural gas CCS plants with more advanced cooling systems. These changes in electric sector technology mix reduce water withdrawal in all scenarios but increase water consumption in aggressive scenarios. Decreased electric sector water withdrawal would likely reduce electric sector vulnerability to climate change, but the rise in consumption could increase competition with other users.Master of Scienc

The effect of metformin on absolute telomere length

In this study, the relationship between average absolute telomere length and metformin use was examined. Human blood samples were obtained from 106 participants ranging from 42-100 years old. Samples were split into four cohorts for analysis: non-type 2 diabetics not taking metformin (Cohort 1), type 2 diabetics taking metformin (Cohort 2), type 2 diabetics not taking metformin (Cohort 3), and non-type 2 diabetics taking metformin. DNA from blood samples were extracted and purified using an and average absolute telomere length was measured using quantitative polymerase chain reaction (qPCR). The average absolute telomere length increased with age for Cohort 2 samples and decreased slightly with age for Cohort 1 samples. This led to the mean average absolute telomere length of Cohort 2 beginning as a lower value than Cohort 1 and then matching and later surpassing the Cohort 1 levels with increased age. This trend was intriguing but showed no statistical significance between the mean average absolute telomere length for Cohort 1 and Cohort 2. Cohort 3, however, had a mean average absolute telomere length which was considerably lower than Cohort 1 and 2. The difference between Cohort 3 and 1 and Cohort 3 and 2 was statistically significant between the ages of 71-80. This lower average absolute telomere length in Cohort 3 when compared to Cohort 2 indicates that metformin use may reduce telomere shortening in older adults. Overall, the findings provide further evidence of metformin’s geroprotective effects, and indicate the need for further, more in depth studies in the future with a larger sample size

The Synthesis and Fine Structure Studies of Polycyclic Aromatic Hydrocarbons

The main part of this thesis has dealt with benzylic coupling in a large number of methyl derivatives of polycyclic aromatic hydrocarbons. It has been shown previously that a coupling constant of ~1.0 Hz. between the methyl protons and the ortho aromatic proton is indicative of a high degree of localisation and double bond character in the intervening bond. This idea has been extended by examining a series of symmetrical 6-dimethyl derivatives which involved synthesising 2' ,3'-dimethyl-1,2;6,7-dibenzo-pyrene, (I) and 6,7-dimethy1-1,2:3-4-dibenzanthracene (II). 9,10-Dimethyl-3,4-benzotetraphene (III) was obtained as a byproduct in the latter synthesis. The couplings in these derivatives add further evidence to the idea that there is only one true double bond in each ring which occupies the lowest energy orbital. The remaining 4 pi-electrons are divided into two higher energy levels with one pair remaining delocalised within the ring,and the third pair, in the highest level, delocalised outside the ring and capable of migrating from ring to ring. An annellation effect is thus observed in passing from o-xylene to 2,3-dimethylanthracene (IV)(V)(VI) which can be explained by the increased linear annellation reducing the influence of those delocalised pi-electrons which are free to migrate, as they are spread over more rings. The distribution of the true double bond can also be considerably affected by substitution in the ring. This is reflected by considerable -changes in the magnitude of the benzylic coupling and supports the additivity of only one true double bond in each ring. The electronic arrangement in pyridazine is in the opposite sense to naphthalene and anthracene. There is a high degree of double bond character in the 4,5 position and a correspondingly low value in the 3,4 and 5,6 positions. This is borne out on examination of a number of methylpyridazines and adds further evidence to the above ideas. Finally, the unusual asymmetry of the methyl resonance in alpha-methyl derivatives was investigated. During this work an explanation was published on the basis of computer analysis of the methyl signal and it appears that the asymmetry is inherent with this combination of couplings to the ortho, para and meta protons on the ring. The apparent lack of long-range coupling in aromatic hydrocarbons has been attributed to 2nd order interactions. In this work halogen derivatives of anthracene and tetracene were examined. Decoupling indicates the absence of para coupling between the protons on non-terminal rings, although there is substantial trans-peri coupling between the protons of a terminal and non-terminal ring. However a methyl group on a non-terminal ring is found to he strongly coupled only to the para proton with J= 0.8-1.0Hz. This value is as large as the coupling constant observed for the localised double bond in 9-methylphenanthrene 1.0 Hz. This evidence is compared with other methyl derivatives and several possible explanations are discussed. The reductive dimerisation of 6-naphthanthrone yielded the known hydrocarbons, dinaphtho-(7', 1' : 1,13): (1", 7" :6, 8) -peropyrene , dinaphtho- -peropyrene and 2,3-trimethylenepyrene along with two new hydrocarbons (VIl) and(VIIl). Circobiphenyl (VII) is a highly condensed hydrocarbon which can be considered as a double coronene. The U.V. spectrum is similar to coronene, however its low solubility has proved a stumbling block in efforts to obtain the n. m. r. spectrum. It was hoped that the protons of this molecule would resonate at low field thus indicating a "superaromaticity" effect analogous to coronene. A new purple hydrocarbon was also obtained and U.V. evidence favours the structure dibenzisoviolanthrene (VIIl). Application of Robinsons aromatic sextet to this structure does not indicate any localised dienophilic regions and therefore this molecule should not react with maleic anhydride. Contrary to expectations, two-fold addition of maleic anhydride does occur in a similar manner to 2,3:4,5:8,9:10,11-tetrabenzoperylene and on this basis the possibility of structure (IX) cannot be excluded. However closer examination of structure (IX) shows that a complete Kekule structure is not possible, despite the fact that alternant marking predicts an equal number of marked and unmarked carbon atoms. The former finding leads to the theoretical prediction of a diradical or higher structure with an inherent instability as shown by triangulene, yet from the alternant marking sbbeme (IXa) a bond across the middle ring involving electrons of opposite spin might be possible. In order to test the above predictions and to try and clarify the reactivity of the purple hydrocarbon with maleic anhydride, an unambiguous synthesis of (IX) was attempted. A series of examples which show the asymmetric annellation of two diphenyl complexes to an acene have been built up over the years. Two of the remaining members of this series are 1,2:3,4:11,12: 13,14-hetrabenzheptacene (x) and 1,2:3,4-dibenzhexacene (xi). A synthesis of the former compound was undertaken to increase the scope of the above series and in an effort to obtain a reasonably stable heptacene derivative

Encoding Featherweight Java with Assignment and Immutability using The Coq Proof Assistant

We develop a mechanized proof of Featherweight Java with Assignment and Immutability in the Coq proof assistant. This is a step towards more machine-checked proofs of a non-trivial type system. We used object immutability close to that of IGJ [8]. We describe the challenges of the mechanization and the encoding we used inside of Coq. prover. Our Coq sources are publically available 1. Example. We define a parametrized class Cell, where the mutable instantiation can get and set the interned object, whereas the immutable instantiation can only get the interned object, provided initially in the constructor. We chose to use transitive mutability in this example. 1