Europa is one of the most interesting satellites in the solar system in the search ofextra-terrestrial life, as it harbours an interior water ocean under its icy surface. Watervapour in Europa’s atmosphere has been previously observed, suggesting water plumeeruptions from the surface. These plumes could potentially originate from the subsurfaceocean, and as such contain ocean constituents that can be examined in orbit. Twoobservations of Europa’s far-ultraviolet shadow on Jupiter were made by the HubbleSpace Telescope in 2018 and 2019. It was observed in Lyman-α (1 216 Å), a spectral lineof hydrogen. This study investigates the imaged Lyman-α shadow in search of potentialplumes at the shadow limb. Examining the shadow instead of the moon itself is a newmethod of remotely studying the Europan atmosphere. Forward modelling is applied tocreate artificial images that are compared to the observations. Any anomalies aroundthe shadow limb are then analysed and evaluated for their statistical significance. Twonoteworthy outliers are found at the limb (one on each occasion) corresponding to H2Oline of sight column densities of 3.07×1017 cm−2 and 4.72×1016 cm−2, for the 2018 and2019 observation, respectively. They are not significant however, as they lie within threestandard deviations from the expected value (< 3σ). An upper limit on what columndensity is detectable in the data is computed, yielding 6.71×1016 cm−2 (using only 2019data due to a weak signal on the 2018 occasion). A constraint on the maximum possibleH2O column density at Europa is thus provided. The new method is shown to be usefulfor the intended purpose and could potentially be applied on other icy moons. / Europa är ett av solsystemets mest intressanta objekt i jakten på utomjordiskt liv, dådet finns ett hav av vatten under månens isiga yta. Vattenånga har tidigare observeratsi Europas atmosfär, vilket kan tyda på vattenplymer som skjuts ut från ytan i kraftigautbrott. Dessa plymer kan möjligtvis ha sitt ursprung i månens inre hav, de kandärför möjliggöra en analys av havsvattnets beståndsdelar i omloppsbana. Europasultravioletta skugga på Jupiter observerades vid två tillfällen 2018 och 2019, av HubbleSpace Telescope. Observationerna gjordes i Lyman-α (1 216 Å), en spektrallinje hos väte.Denna studie undersöker den avbildade skuggan i Lyman-α för att söka efter potentiellavattenplymer vid skuggans rand. Att undersöka skuggan istället för själva månen är en nymetod för att studera Europas atmosfär genom fjärranalys. Metoden forward modellinganvänds för att skapa artificiella bilder, som jämförs med observationerna. Eventuellaavvikelser som hittas runt skuggans rand analyseras sedan och deras statistiska signifikansutvärderas. Två anmärkningsvärda avvikelser kan hittas vid randen (en vid varjeobservationstillfälle), som motsvarar H2O-kolumndensiteter på 3.07 × 1017 cm−2 och4.72 × 1016 cm−2, för 2018-observationen respektive 2019-observationen. Densiteternaär dock inte signifikanta, då de ligger inom tre standardavvikelser från deras förväntadevärden (< 3σ). Istället beräknas en övre gräns för vilken kolumndensitet som kandetekteras i datan, vilket ger 6.71 × 1016 cm−2 (där endast 2019-data används på grundav en svag signal hos 2018-observationen). Den högsta möjliga H2O-kolumndensitetenkan således begränsas. Den nya metoden visar sig vara användbar för det tänkta syftetoch kan eventuellt appliceras på andra ismånar.

Biological signal processing can help us gain knowledge about biological complexity, as well as using this knowledge to engineer better systems. Three areas are identified as critical to understanding biology: 1) understanding DNA, 2) examining the overall biological function and 3) evaluating these systems in environmental (ie: turbulent) conditions. DNA is investigated for coding structure and redundancy, and a new tandem repeat region, an indicator of a neurodegenerative disease, is discovered. The linear algebraic framework can be used for further analysis and techniques. The work illustrates how signal processing is a tool to reverse engineer biological systems, and how our better understanding of biology can improve engineering designs. Then, the way a single-cell mobilizes in response to a chemical gradient, known as chemotaxis, is examined. Inspiration from receptor clustering in chemotaxis combined with a Hebbian learning method is shown to improve a gradient-source (chemical/thermal) localization algorithm. The algorithm is implemented, and its performance is evaluated in diffusive and turbulent environments. We then show that sensor cross-correlation can be used in solving chemical localization in difficult turbulent scenarios. This leads into future techniques which can be designed for gradient source tracking. These techniques pave the way for use of biologically-inspired sensor networks in chemical localization.

No description available.

The introduced mineral deposit model (MDM) is the product of a trans-disciplinary study, based on Complexity and General Systems Theory. Both investigate the abstract organization of phenomena, independent of their substance, type, or spatial or temporal scale of existence. The focus of the research has been on giant, hydrothermal mineral deposits. They constitute <0.001% of the total number of deposits yet contain 70-85% of the world's metal resources. Giants are the definitive exploration targets. They are more profitable to exploit and less susceptible to fluctuations of the market. Consensus has it that the same processes that generate small deposits also form giants but those processes are simply longer, vaster, and larger. Heat is the dominant factor in the genesis of giant mineral deposits. A paleothermal map shows where the vast heat required to generate a giant has been concentrated in a large space, and even allows us to deduce the duration of the process. To generate a paleothermal map acceptable to the scientific community requires reproducibility. Experimentation with various approaches to pattern recognition of geochemical data showed that the AUTOCLUST algorithm not only gave reproducibility but also gave the most consistent, most meaningful results. It automatically extracts boundaries based on Voronoi and Delaunay tessellations. The user does not specify parameters; however, the modeller does have tools to explore the data. This approach is near ideal in that it removes much of the human-generated bias. This algorithm reveals the radial, spatial distribution, of gold deposits in the Lachlan Fold Belt of southeastern Australia at two distinct scales – repeating patterns every ~80 km and ~230 km. Both scales of patterning are reflected in the geology. The ~80 km patterns are nested within the ~230 km patterns revealing a self-similar, geometrical relationship. It is proposed that these patterns originate from Rayleigh-Bénard convection in the mantle. At the Rayleigh Number appropriate for the mantle, the stable planform is the spoke pattern, where hot mantle material is moving upward near the centre of the pattern and outward along the radial arms. Discontinuities in the mantle, Rayleigh-Bénard convection in the mantle, and the spatial distribution of giant mineral deposits, are correlative. The discontinuities in the Earth are acting as platforms from which Rayleigh-Bénard convection can originate. Shallow discontinuities give rise to plumelets, which manifest at the crust as repeating patterns ranging, from ~100 to ~1,000 km in diameter. Deeper discontinuities give rise to plumes, which become apparent at the crust as repeating patterns ranging from >1,000 to ~4,000 km in diameter. The deepest discontinuities give rise to the superplumes, which become detectable at the crust as repeating patterns ranging from >4,000 to >10,000 km in diameter. Rayleigh-Bénard convection concentrates the reservoir of heat in the mantle into specific locations in the crust; thereby providing the vast heat requirements for the processes that generate giant, hydrothermal mineral deposits. The radial spatial distribution patterns observed for gold deposits are also present for base metal deposits. At the supergiant Broken Hill deposit in far western New South Wales, Australia, the higher temperature Broken Hill-type deposits occur in a radial pattern while the lower temperature deposits occur in concentric patterns. The supergiant Broken Hill deposit occurs at the very centre of the pattern. If the supergiant Broken Hill Deposit was buried beneath alluvium, water or younger rocks, it would now be possible to predict its location with accuracy measured in tens of square kilometres. This predictive accuracy is desired by every exploration manager of every exploration company. The giant deposits at Broken Hill, Olympic Dam, and Mount Isa all occur on the edge of an annulus. There are at least two ways of creating an annulus on the Earth's surface. One is through Rayleigh-Bénard convection and the other is through meteor impact. It is likely that only 'large' meteors (those >10 km in diameter) would have any permanent impact on the mantle. Lesser meteors would leave only a superficial scar that would be eroded away. The permanent scars in the mantle act as ‘accidental templates’ consisting of concentric and possibly radial fractures that impose those structures on any rocks that were subsequently laid down or emplaced over the mantle. In southeastern Australia, the proposed Deniliquin Impact structure has been an 'accidental template' providing a 'line-of-least-resistance' for the ascent of the ~2,000 km diameter, offshore, Cape Howe Plume. The western and northwestern radial arms of this plume have created the very geometry of the Lachlan Fold Belt, as well as giving rise to the spatial distribution of the granitic rocks in that belt and ultimately to the gold deposits. The interplay between the templating of the mantle by meteor impacts and the ascent of plumelets, plumes or superplumes from various discontinuities in the mantle is quite possibly the reason that mineral deposits occur where they do.

The introduced mineral deposit model (MDM) is the product of a trans-disciplinary study, based on Complexity and General Systems Theory. Both investigate the abstract organization of phenomena, independent of their substance, type, or spatial or temporal scale of existence. The focus of the research has been on giant, hydrothermal mineral deposits. They constitute <0.001% of the total number of deposits yet contain 70-85% of the world's metal resources. Giants are the definitive exploration targets. They are more profitable to exploit and less susceptible to fluctuations of the market. Consensus has it that the same processes that generate small deposits also form giants but those processes are simply longer, vaster, and larger. Heat is the dominant factor in the genesis of giant mineral deposits. A paleothermal map shows where the vast heat required to generate a giant has been concentrated in a large space, and even allows us to deduce the duration of the process. To generate a paleothermal map acceptable to the scientific community requires reproducibility. Experimentation with various approaches to pattern recognition of geochemical data showed that the AUTOCLUST algorithm not only gave reproducibility but also gave the most consistent, most meaningful results. It automatically extracts boundaries based on Voronoi and Delaunay tessellations. The user does not specify parameters; however, the modeller does have tools to explore the data. This approach is near ideal in that it removes much of the human-generated bias. This algorithm reveals the radial, spatial distribution, of gold deposits in the Lachlan Fold Belt of southeastern Australia at two distinct scales – repeating patterns every ~80 km and ~230 km. Both scales of patterning are reflected in the geology. The ~80 km patterns are nested within the ~230 km patterns revealing a self-similar, geometrical relationship. It is proposed that these patterns originate from Rayleigh-Bénard convection in the mantle. At the Rayleigh Number appropriate for the mantle, the stable planform is the spoke pattern, where hot mantle material is moving upward near the centre of the pattern and outward along the radial arms. Discontinuities in the mantle, Rayleigh-Bénard convection in the mantle, and the spatial distribution of giant mineral deposits, are correlative. The discontinuities in the Earth are acting as platforms from which Rayleigh-Bénard convection can originate. Shallow discontinuities give rise to plumelets, which manifest at the crust as repeating patterns ranging, from ~100 to ~1,000 km in diameter. Deeper discontinuities give rise to plumes, which become apparent at the crust as repeating patterns ranging from >1,000 to ~4,000 km in diameter. The deepest discontinuities give rise to the superplumes, which become detectable at the crust as repeating patterns ranging from >4,000 to >10,000 km in diameter. Rayleigh-Bénard convection concentrates the reservoir of heat in the mantle into specific locations in the crust; thereby providing the vast heat requirements for the processes that generate giant, hydrothermal mineral deposits. The radial spatial distribution patterns observed for gold deposits are also present for base metal deposits. At the supergiant Broken Hill deposit in far western New South Wales, Australia, the higher temperature Broken Hill-type deposits occur in a radial pattern while the lower temperature deposits occur in concentric patterns. The supergiant Broken Hill deposit occurs at the very centre of the pattern. If the supergiant Broken Hill Deposit was buried beneath alluvium, water or younger rocks, it would now be possible to predict its location with accuracy measured in tens of square kilometres. This predictive accuracy is desired by every exploration manager of every exploration company. The giant deposits at Broken Hill, Olympic Dam, and Mount Isa all occur on the edge of an annulus. There are at least two ways of creating an annulus on the Earth's surface. One is through Rayleigh-Bénard convection and the other is through meteor impact. It is likely that only 'large' meteors (those >10 km in diameter) would have any permanent impact on the mantle. Lesser meteors would leave only a superficial scar that would be eroded away. The permanent scars in the mantle act as ‘accidental templates’ consisting of concentric and possibly radial fractures that impose those structures on any rocks that were subsequently laid down or emplaced over the mantle. In southeastern Australia, the proposed Deniliquin Impact structure has been an 'accidental template' providing a 'line-of-least-resistance' for the ascent of the ~2,000 km diameter, offshore, Cape Howe Plume. The western and northwestern radial arms of this plume have created the very geometry of the Lachlan Fold Belt, as well as giving rise to the spatial distribution of the granitic rocks in that belt and ultimately to the gold deposits. The interplay between the templating of the mantle by meteor impacts and the ascent of plumelets, plumes or superplumes from various discontinuities in the mantle is quite possibly the reason that mineral deposits occur where they do.

The introduced mineral deposit model (MDM) is the product of a trans-disciplinary study, based on Complexity and General Systems Theory. Both investigate the abstract organization of phenomena, independent of their substance, type, or spatial or temporal scale of existence. The focus of the research has been on giant, hydrothermal mineral deposits. They constitute <0.001% of the total number of deposits yet contain 70-85% of the world's metal resources. Giants are the definitive exploration targets. They are more profitable to exploit and less susceptible to fluctuations of the market. Consensus has it that the same processes that generate small deposits also form giants but those processes are simply longer, vaster, and larger. Heat is the dominant factor in the genesis of giant mineral deposits. A paleothermal map shows where the vast heat required to generate a giant has been concentrated in a large space, and even allows us to deduce the duration of the process. To generate a paleothermal map acceptable to the scientific community requires reproducibility. Experimentation with various approaches to pattern recognition of geochemical data showed that the AUTOCLUST algorithm not only gave reproducibility but also gave the most consistent, most meaningful results. It automatically extracts boundaries based on Voronoi and Delaunay tessellations. The user does not specify parameters; however, the modeller does have tools to explore the data. This approach is near ideal in that it removes much of the human-generated bias. This algorithm reveals the radial, spatial distribution, of gold deposits in the Lachlan Fold Belt of southeastern Australia at two distinct scales – repeating patterns every ~80 km and ~230 km. Both scales of patterning are reflected in the geology. The ~80 km patterns are nested within the ~230 km patterns revealing a self-similar, geometrical relationship. It is proposed that these patterns originate from Rayleigh-Bénard convection in the mantle. At the Rayleigh Number appropriate for the mantle, the stable planform is the spoke pattern, where hot mantle material is moving upward near the centre of the pattern and outward along the radial arms. Discontinuities in the mantle, Rayleigh-Bénard convection in the mantle, and the spatial distribution of giant mineral deposits, are correlative. The discontinuities in the Earth are acting as platforms from which Rayleigh-Bénard convection can originate. Shallow discontinuities give rise to plumelets, which manifest at the crust as repeating patterns ranging, from ~100 to ~1,000 km in diameter. Deeper discontinuities give rise to plumes, which become apparent at the crust as repeating patterns ranging from >1,000 to ~4,000 km in diameter. The deepest discontinuities give rise to the superplumes, which become detectable at the crust as repeating patterns ranging from >4,000 to >10,000 km in diameter. Rayleigh-Bénard convection concentrates the reservoir of heat in the mantle into specific locations in the crust; thereby providing the vast heat requirements for the processes that generate giant, hydrothermal mineral deposits. The radial spatial distribution patterns observed for gold deposits are also present for base metal deposits. At the supergiant Broken Hill deposit in far western New South Wales, Australia, the higher temperature Broken Hill-type deposits occur in a radial pattern while the lower temperature deposits occur in concentric patterns. The supergiant Broken Hill deposit occurs at the very centre of the pattern. If the supergiant Broken Hill Deposit was buried beneath alluvium, water or younger rocks, it would now be possible to predict its location with accuracy measured in tens of square kilometres. This predictive accuracy is desired by every exploration manager of every exploration company. The giant deposits at Broken Hill, Olympic Dam, and Mount Isa all occur on the edge of an annulus. There are at least two ways of creating an annulus on the Earth's surface. One is through Rayleigh-Bénard convection and the other is through meteor impact. It is likely that only 'large' meteors (those >10 km in diameter) would have any permanent impact on the mantle. Lesser meteors would leave only a superficial scar that would be eroded away. The permanent scars in the mantle act as ‘accidental templates’ consisting of concentric and possibly radial fractures that impose those structures on any rocks that were subsequently laid down or emplaced over the mantle. In southeastern Australia, the proposed Deniliquin Impact structure has been an 'accidental template' providing a 'line-of-least-resistance' for the ascent of the ~2,000 km diameter, offshore, Cape Howe Plume. The western and northwestern radial arms of this plume have created the very geometry of the Lachlan Fold Belt, as well as giving rise to the spatial distribution of the granitic rocks in that belt and ultimately to the gold deposits. The interplay between the templating of the mantle by meteor impacts and the ascent of plumelets, plumes or superplumes from various discontinuities in the mantle is quite possibly the reason that mineral deposits occur where they do.

MENVSC / Department of Hydrology and Water Resources / ABSTRACT Siloam and Tshipise Springs are scalding geothermal springs geologically located within the Soutpansberg Group in the Limpopo Province of South Africa. These geothermal springs are associated with faults and impermeable dykes and are assumed to be of meteoric origin. The optimal use of a geothermal spring largely depends upon its physical and chemical properties as well as the geological controls at source and surrounding pathway to the surface. This study aimed at investigating trace element concentrations in these geothermal springs in order to quantify their impacts on neighbouring soil and vegetation. Impact on vegetation was assessed by incorporating seasonal variations of the trace element mobility from the geothermal springs to the vegetation (Mangifera indica at Siloam and Acacia robusta at Tshipise) via soil. The geothermal spring water, soil and vegetation samples at both sites were collected from May – July (winter) and September – November (summer), 2014. The soil samples were collected at 5 m intervals up to 20 m away from the geothermal spring in each of the sites. The bark and leaf parts of the vegetation were sampled. The control samples for water, soil and vegetation were obtained from Riverside residence at University of Venda, Thohoyandou, Limpopo Province, where there is non-geothermal source of water. The temperature, electrical conductivity (EC), pH and total dissolved solid (TDS) of the geothermal spring water and control samples were determined in situ and in the laboratory. The water samples were acidified for major cations and trace elements determination. There were also non-acidified water samples for major anion analyses. The soil and vegetation samples were digested using microwave and hot block methods, respectively. Concentrations of arsenic (As), antimony (Sb), barium (Ba), beryllium (Be), boron (B), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), mercury (Hg), lanthanum (La), lead (Pb), lithium (Li), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se), tin (Sn), strontium (Sr), tellurium (Te), thallium (Tl), titanium (Ti), tungsten (W), vanadium (V), and zinc (Zn) were determined by inductively coupled plasma – mass spectrometry (ICP-MS) (Agilent 7700 series). Concentrations of calcium (Ca), magnesium (Mg), sodium (Na) and potassium (K) were analysed using inductively coupled plasma – optical emission spectrometry (ICP-OES) (X – Series 2) whereas the concentrations of chloride (Cl-), fluoride (F-), nitrate (NO3-), phosphate (PO42-), bicarbonate (HCO3-) and sulphate (SO42-) were determined by ion chromatography (IC) (Dionex Model DX 500). Results from this study revealed that the geothermal springs were rich in trace elements compared to that from non-geothermal source of water. The mineral elements present were vii mainly due to rock-water interaction in the deep aquifer at both sites. The geothermal spring water is not fit for drinking because it is particularly high in fluoride (F) having 6.66 and 5.97 mg/L at Siloam ; 6.72 and 7.28 mg/L at Tshipise for winter and summer, respectively. Also, high Nickel (Ni) with 462 µg/L and 868 µg/L: Lead (Pb) with 652 µg/L and 211 µg/L at Siloam and Tshipise respectively, for summer season. In addition, it is not suitable for irrigation owing to high sodium absorption ratio (SAR) values which were above the standard guidelines (˂1) by South African Bureau of Standards (SABS) and World Health Organization (WHO) at both sites. In summer season, there were higher trace elements concentrations than in the winter season. The higher concentration values could be attributed to rainfall, which aids in the dissociation of rock particles, resulting in higher concentrations of these elements. Siloam spring water was more mineralised than Tshipise spring water, hence its neighbouring soils and vegetation possess more trace elements concentrations than the latter. Owing to their high mineral elements content, the geothermal spring water flows across the soil, making it vulnerable to sorption of the trace elements. The trace elements present in the surrounding soil of the geothermal spring were as a result of geothermal water and soil pedogenesis. The geothermal water contaminates the surrounding soil with substantial quantity of trace elements, which decreases with the distance from the geothermal spring, making far distanced soil less-contaminated. High levels of Cr, Co, Ni, Cu, Zn and Pb at Siloam soil can be attributed to more minerals present in the spring, therefore making absorption by Mangifera indica inevitable. Soils at Tshipise are moderately concentrated owing to moderate trace elements concentrations from the geothermal spring water. Generally, seasonal variations were observed in the parameters analysed in the geothermal spring water, surrounding soil and vegetation to ascertain the most favourable season in terms of the trace elements concentrations. There were higher concentrations of trace elements in the geothermal spring, particularly during the summer season, compared to the winter season; this leads to more contamination of the surrounding soils and vegetation. This study showed that geothermal spring has potential to enrich the neighbouring soils and vegetation with trace elements, which could result in contamination. It can be concluded that geothermal spring, despite its benefits to humans, also contaminates the surrounding surface soils with toxic trace elements. Soils are a platform for vegetation. Therefore, if the soil is contaminated by toxic elements, there are high possibilities that these trace elements are absorbed by the neighbouring vegetation, which is likely to affect human beings adversely.

The study is developed from five in-depth interviews with individuals from different walks of life who have interacted significantly with the North Sea. The study discusses change in the North Sea specifically in the development of fixed turbine wind farms and their physical and aesthetic effects. Observations speakers make as to changes in the North Sea and as to its beauty are contextualised and discussed using NASA satellite images, photographs and review of available academic literature, UK policy documents and law. This context includes a study of the industrialised North Sea with reference to the sediment sea plumes behind monopile turbines. The United Kingdom was selected for particular study of its wind farm development permissions process, including evaluations of seascape and the requirement of independence for expert evidence. Decline of trawler access to the North Sea is referenced to wind farm growth, and to adverse changes in public opinion leading to closure of the UK Dogger Bank to trawlers. Finality of wind farm development decisions is considered against the prospect of overturn by the courts. This aspect covers the application and development of principles relating to appeal by way of judicial review in the UK jurisdictions of Scotland, England and Wales, and Northern Ireland. The study identifies, and explains the English aesthetic evaluation of wind farms. It concludes that sea plumes are the result of a legal choice to allow permit applications to succeed without testing by reference to detailed in-sea turbine dimensions. In the permissions process (a) sea plumes are not evaluated by the seascape criteria applicable to coastal or off-coastal wind farms (b) deep offshore wind farms are instead evaluated by possible changes to character of the sea. The study further concludes that (i) the open horizon of the North Sea has been lost in significant part (ii) the combined aesthetic of transience, decay, and nostalgia underlies the aesthetic of the North Sea Maunsell forts (contrasted to Sealand), and also underlies attitudes to decommissioning wind farms, and (iii) concepts of sea beauty may be based on appearance or health, being regulated by different legal regimes in each eventuality (respectively the European Landscape Convention, or the OSPAR/ biodiversity/ habitat initiatives)