Dissertations / Theses on the topic 'Marble mining'

ABSTRACT MODELING A MODERN MARBLE PROCESSING PLANT BY USING PETRI NET Keser, Ö
zge M. Sc., Department of Mining Engineering Supervisor: Prof Dr. NeS&rsquo
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elebi Co-Supervisor: Prof Dr. Tevfik Gü
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ler December 2003, 110 pages All developing countries need sufficient raw material resources to develop and to guarantee their future. Considering Turkish natural resources, marble has a great importance because of its demand on the market, reserve amount and quality. However, some effort is required to improve the existing marble production and processing efficiency. Petri nets (PNs) are the information models that control the flow for concurrent and synchronous systems. In this regard, PN application can be useful. However, its application is limited to the complex systems and no application of PN is available in mining sector. iii In this sense, this study aims to examine the applicability of PN to mining. This study examines the production system in order to optimize the process in case of two different types of marble product orders. Three case studies are applied to examine benefits and difficulties in implementation of PN to a marble processing plant. The study shows that PN can successfully be used as a tool for the optimization of total production time, simulation and modeling of the system. It provides to see the sequence of the processes, their time, remaining time of each transition and optimum total production times. The difficulties of PN implementation are found out as the determination of each path in the reachability graph, matrix representation with large quantity of place, etc.

Das Erzgebirge verfügt über beträchtliche Marmorvorkommen. Schon seit Jahrhunderten sind die Kalzit- und Dolomitmarmore als Düngemittel, später als Grundstoffe in der chemischen Industrie, in der Glasproduktion und als Zuschlagstoffe in der Baustoffindustrie begehrt. Die Monografie enthält die geologische Beschreibung von über 100 Marmorlagerstätten auf sächsischem und tschechischem Gebiet. Die Marmorvorkommen werden anhand von geologischen Übersichtskarten, Rissausschnitten, geologischen Schnitten und zahlreichen Fotos beschrieben. Schwerpunkte sind dabei die geschichtliche Entwicklung des jeweiligen Abbaus, die geologischen Verhältnisse, die bergtechnischen Bedingungen, die Verwendung des Rohstoffs und die Einflüsse des Marmorbergbaus auf die Umwelt. Die aufbereiteten Daten sind für künftige Bergbauunternehmungen von Interesse.

The exploitation of rock material usually results in a change of the in-situ force field surrounding the rock mass. Mine design is one of the major challenges when planning and operating a mine in a complex environmental context such as the Apuan Alps marble district (Italy). There could be significant risks related to the safety of both personnel and equipment. This research focuses on data collection, geo-structural interpretation and rock mechanics analysis by means of advanced remote sensing techniques (e.g. Structure for Motion methods, Terrestrial Laser Scanning, change detection analysis, etc.), numerical modelling for the stability analysis of both surface and underground structures, and modelling of brittle failure. In particular, this research investigates the application of Remotely Piloted Aircraft Systems (RPASs) and of Structure from Motion (SfM) methods for geo-hazard identification, awareness and risk reduction. Limit equilibrium and numerical analyses were carried out to study the stability of two large marble blocks in an open pit marble mine area. These analyses were focused on the important role that rock bridges have on slope stability, and to investigate the active-passive wedge mechanism that may develop due to rock mass strength degradation and brittle failure mechanisms. Additionally, the spalling failure of an underground marble pillar was investigated to include a multifaceted/multitemporal stability analysis with the objective of studying mining engineering issues related with the extraction of valuable rock resources. Morphological variations were identified using a change detection approach and analysed using both Finite Element (FEM) and hybrid Finite-Discrete Element (FDEM) methods. In this context, understanding the mechanical behaviour of a rock mass has always been a major concern for increasing the safety and minimizing economic loss. A mine design concerns the stability of the excavations, including the potential collapse of slopes and quarry faces, spalling of the sidewalls, and the structurally controlled failure of the underground openings. The cornerstone of an engineering understanding of a rock mass structure is represented by data collection and interpretation. The starting point is represented by the knowledge of the lithologies and the major structural features present in the rock mass. Such information provides essential background to rock mechanics studies, but may be available in limited form using classical mapping techniques due to the limited accessibility of rock outcrops. Indeed, measurements can be made on natural slopes or on faces exposed by surface excavations, but the data collected may not be representative of the whole site. In this context, it is now possible to drastically increase the quantity of mapping information by using advanced and modern geomatics techniques. In order to analyse rock outcrops, the use of RPAS allows to overcome data acquisition issues related to high steep quarry walls, while at the same time it provides high resolution images and 3D models. This is particularly important because fractures characteristics may be spatially variable due to stress relaxation induced by excavation activity. Terrestrial Laser Scanning allows to rapidly acquire information as point clouds with a millimetre level of detail from the surrounding surfaces. Both aerial and terrestrial measurement techniques can be useful to perform detailed and accurate structural analysis and periodical estimates of surface changes by means of the so-called change detection analysis, in order to identify modified surfaces in the mining area. In this context, geomatics techniques and conventional geological/engineering-geological surveys techniques should be used simultaneously because when used together they allow to reduce data uncertainty and to provide a better characterisation of data variability. Indeed, the reliability of the analysis depends on the quality, quantity and interpretation of available field information. Many design structures in mine engineering practice involve complex problems and it is often necessary to carry out detailed rock mechanics analysis using powerful numerical tools. Indeed, stress and stability analysis can be carried out using continuous and/or discontinuous numerical approaches. These techniques are currently used in the civil and mining engineering sectors due to the possibility to take account of complex rock mass deformation and failure. Numerical methods allow to consider the whole rock mass mechanical behaviour on the contrary of classical approaches that, for example, consider a block as an isolated object. In this context, numerical methods are able to investigate and illustrate the involved rock failure mechanisms during mining activities and particularly the initiation, propagation, and coalescence of cracks, and the propagation of discrete fractures.

Das Erzgebirge verfügt über beträchtliche Marmorvorkommen. Schon seit Jahrhunderten sind die Kalzit- und Dolomitmarmore als Düngemittel, später als Grundstoffe in der chemischen Industrie, in der Glasproduktion und als Zuschlagstoffe in der Baustoffindustrie begehrt. Die Monografie enthält die geologische Beschreibung von über 100 Marmorlagerstätten auf sächsischem und tschechischem Gebiet. Die Marmorvorkommen werden anhand von geologischen Übersichtskarten, Rissausschnitten, geologischen Schnitten und zahlreichen Fotos beschrieben. Schwerpunkte sind dabei die geschichtliche Entwicklung des jeweiligen Abbaus, die geologischen Verhältnisse, die bergtechnischen Bedingungen, die Verwendung des Rohstoffs und die Einflüsse des Marmorbergbaus auf die Umwelt. Die aufbereiteten Daten sind für künftige Bergbauunternehmungen von Interesse.

The diploma thesis tries to introduce possibilities of marble mining in moravian locality of Ujčov on the basis of feasibility study. Background of the practical part of the work is built on expert opinions on the stone resources, experts in the field consultations and communication with potential suppliers. The study results into a preliminary financial plan of the project, which quantifies reached conclusions. The text also considers possible ventures. The thesis also aims to be a base for a business plan.

Tese de Mestrado em Arquitectura com Especialização em Planeamento Urbano e Territorial.
As pedreiras são fenómenos singulares ilustrativos das relações entre o homem e os valores do território. São paisagens exclusivas, identitárias da cultura das regiões em que se inserem, tal como dos recursos endógenos do meio, e neste sentido afirmam-se como fenómenos singulares pelo que devem ser defendidas e preservadas. Estas paisagens pela sua própria natureza e dimensões, na ausência de tratamento ambiental e paisagístico, podem repercutir-se pejorativamente. A não sustentabilidade das actividades extractivas impõem um limite ao seu desenvolvimento. Pelo que, após as explorações, a recuperação da área afectada é um imperativo legislativo. Assegurando o equilíbrio ecológico e a qualidade paisagística do local. As mesmas características e especificidades das pedreiras que incitam ao prejuízo atribuem, por outro lado, um carácter excepcional a estas paisagens. As áreas extractivas após o término da sua função genérica podem representar a oportunidade de serem reconvertidas em novos valores. A reabilitação de uma pedreira pode perpetuar o propósito útil do espaço, valorizando as especificidade da paisagem e a sua competitividade. A sua reconversão em novos atractivos pode beneficiando a região e da população e, simultaneamente, assegurar o equilíbrio e qualidade do meio e da paisagem.

No presente documento é feita a descrição dos trabalhos de extração e transformação de mármore, bem como de todos os equipamentos e normas utilizadas neste processo, tendo sido feito todo o acompanhamento técnico dos trabalhos executados. Apresenta-se ainda o estudo de uma nova área de exploração com vista ao alargamento da cavidade extrativa tendo como base as caraterísticas geológicas da região. Este estudo foi complementado com a realização e análise de uma sondagem como meio de prospeção. Finalmente são expostas as tarefas de controlo de produção associadas à aplicação da Marcação CE; ABSTRACT: Technical Monitoring and Production Quality Control in the Quarry and Sawmilling of Plácido José Simões S.A. Company. Marble extraction and transformation activities are described in this work. Equipment, procedures and norms used in this dimension stone chain processing are also detailed. The technical monitoring of the work performed in the Plácido Simões company quarry and processing plant having also been done. It is also presented the study of a new area of exploration aiming at extending the mining cavity having as a basis the geological characteristics of the region. This study was complemented with the making and analysis of a mining survey drilling as means of prospection. Finally the production control tasks associated with the implementation of CE marking are explained and described in detail.

Includes abstract.
Includes bibliographical references.
Sand, an important input to the construction industry, is extensively mined from the environment leading to depletion of the resource as well as damage to riparian habitat and the alteration of river beds and banks. Sand mining in South Africa is controlled by a complex regulatory system that can be distilled into three main themes: mineral regulation; environmental regulation; and land use planning regulation. In this thesis, it is hypothesised that sand mining is subject to all three regulatory themes equally. In practice, however, the regulatory system is skewed in favour of mineral regulation with the effect that the latter two themes are effectively ignored by sand miners.

Targeting marine diamondiferous deposits along the south-western Namibian coastline has involved the construction of seawall berms to advance the coastline and permit mining in previously subtidal areas. Large areas are mined out to bedrock level by the removal of overburden (sand and gravel), and after mining is complete, areas behind the seawalls fill with seawater, creating a series of coastal marine ponds that have the potential to function as saline wetlands corresponding to closed estuaries. The study site lies north of the Orange River mouth, within the Tsau//Khaeb (Sperrgebiet) National Park, to which the public has restricted access due to diamond mining in the area. Consequently, there is a focus on biodiversity conservation and the overall objective of this thesis was to determine the ecological value of the mining ponds by investigating whether they harbour sufficient biodiversity to qualify as a viable alternative ecological habitat, rather than restoring them to their original state as backfilled, revegetated dune areas. The study area, approximately 75 kilometres in length, was divided into north, middle and south sections, according to the age and status of mining activities, and I first assessed whether ponds in these three areas differed in their physical properties (Chapter 1). To determine whether the ponds serve as a useful ecological role worth preserving, I then investigated the diversity and amount of saltmarsh vegetation (Chapter 2), bird species (Chapter 3) and fish (Chapter 4) currently benefiting from these mining ponds. Ponds in the north are older and hypersaline whereas the south and middle ponds are younger and closely approach physical conditions in the sea. Diurnal fluctuations in oxygen concentration took place, but oxygen levels never dropped below 80% and were thus not limiting. After about 15 years, ponds developed salinities in excess of 80‰, which is likely to set limits on their ecological viability. Most ponds supported saltmarshes, but only a single species, Salicornia natalensis, grew around them. Its abundance was greatest around old ponds, but its health decreased with salinity. Wind emerged as a likely means of dispersal among ponds. The ponds supported a rich avifauna, averaging 11028 birds per count for all ponds combined; 36 species were recorded, ten being endemics, and five being listed in Namibia's Red Data Book. Numbers were highest for ponds that were being ‘dewatered' to remove water prior to mining, as this exposed a rich benthic epifaunal source of food. Blacknecked Grebe, Cape Cormorant, Greater and Lesser Flamingos, Kelp Gull and Common Tern were the most abundant birds. Salinity did not limit bird numbers or diversity, so the northern high-salinity ponds may continue to serve as bird habitat for periods of time much greater than the 15 years after which they become hypersaline. In comparison with nine other wetlands in the region, the ponds had great numbers, diversity, densities, and numbers of threatened species than about half of these wetlands, many of which are considered Important Bird Areas (IBAs). In many cases, they also supported more species that had numbers in excess of 1% of the southern African population than these IBAs. Only two species of fish commonly occurred in the ponds, the west coast steenbras Lithognathus auratus and the southern mullet Chelon richardsonii, although small numbers of two other marine species were recorded. The diversity of marine fish was thus low, even by the impoverished standards of west-coast estuaries. Unexpectedly, there were no significant differences between the ichthyofauna of ponds in the north, middle and south, nor was there any relationship between total fish numbers and salinity. Body condition of steenbras was lowest in the hypersaline north ponds, and their stomach contents contained a low diversity of food items there. The presence of recruits and the range of gonadal states suggested that both species bred in the ponds. Steenbras proved to be protandrous, with females dominating larger size classes. Growth rates of both species were faster in the ponds than in the adjacent sea, and mullet achieved substantially greater sizes in ponds. Thus, the ponds do serve as viable ecosystems, albeit with a limited range of saltmarsh and fish species, and support an impressively diverse avifauna. Their long-term viability will, however, become limited by rising salinity as their age increases.

The aggregate market of the Eastern United States is quantitatively modelled and the interaction of its components measured. Concrete and paving aggregate were the selected types for the purposes of this study. Using 1987 as base year, production is segmented into geographic units by using information obtained from the Mine Safety and Health Administration. The quarry price is given by an empirical relation, accounting for urbanization, and based on an extensive telephone survey. The global demand is determined by econometric procedures. The break-down by geographic unit is performed using construction data in an input/output manner. Transport, which is multi-modal, is simulated by linear programming. These concepts are consolidated by the optimisation of aggregate distribution. The model developed is used to simulate different situations, demonstrating the reliability of the obtained solutions.

Bibliography: pages 94-99.
The primary aim of this study was to assess the rate of recovery of macrobenthic communities after offshore marine mining. Three techniques, namely univariate, distributional and multivariate, were used to make this assessment. Two distinct areas, the northern and southern research areas, were investigated, and statistical and numerical analyses were conducted for each area independently. Data were aggregated to, and analysed at, the genus level. Replicates were arranged in temporal categories according to recent mining history. The northern research area appears to be affected by mining activity in terms of species composition, but not species diversity. Statistical testing detected significant differences between unmined replicates and all other temporal categories for this area, and this was also discernible in the cluster analysis and ordination plots. The overall picture generated suggests that the northern research area is affected immediately and severely by mining activity, resulting in rapid changes in species composition. However, the period of 15-19 months subsequent to mining is insufficient to allow the community to recover to a stable state. The southern research area, on the other hand, shows a slightly different scenario, with mining activity having a severe and immediate impact on both species composition as well as species diversity. Recently mined sites were found to be significantly different from both unmined sites and sites mined 43-51 months ago. The latter two categories were not found to be significantly different from each other. The results suggest that the road to recovery in the southern research area is a slow, but steady one in terms of species composition. This was particularly apparent in the results of the "SIMPER" analysis where the level of similarity between temporal categories increased steadily with time after mining. The overall picture suggests that the area has recovered substantially after 43-51 months, and that the community approximates that of the unmined area with regard to species composition. Geological analyses were also conducted, with results indicating a prevalence of fine surficial sediment particles in unmined sites, and coarse surficial sediment particles in recently mined sites. Percentage gravel, in particular, was found to be a reliable indicator of the condition of a site with regard to the level of disturbance. Altered stratigraphy and changes in particle size distribution as a result of mining activity are considered to have a noticeable effect on the structure of benthic communities. A number of taxa were found to be particularly reliable as indicator species. In both the northern and southern research areas, polychaetes (specifically Prionospio pinnata and the Lumbrineris genus) were abundant in unmined sites as well as in sites mined 43-51 months ago in the southern research area. Individuals of the genus Nassarius, on the other hand, were scarce in unmined sites, but abundant in recently mined sites. These taxa appear to be reliable indicators of the level of recovery attained in previously mined areas.

This study focusses on the marine diamond placers within Exclusive Prospecting Licence 1950 and Mining Licence 103a, located northwest of the north-facing Hottentot Bay which is 60 km north of Lüderitz, along the central Namibian coastline. The thesis follows the natural geological evolution of the marine placer deposit from primary source, through alluvial and/or glacial transportation, concentration along the coastline by wave, aeolian and alluvial/sheet-wash processes and finally marine diamond placer preservation. All of these processes are reviewed as they are important in understanding of the evolution marine placer deposits. The poly-cyclic role of coastal aeolian, alluvial, and marine processes, in marine placer enrichment is shown to be particularly important in considered target identification and prioritisation. A detailed bathymetric, sonographic and seismic interpretation, is an integral part of diamond placer exploration, and was used to examine and describe surficial and sub-bottom characteristics within the study area. Marine placers are formed along palaeo-strandlines during periods of marine transgression and regression and are therefore fundamental in marine placer exploration. A detailed bathymetry map, compiled for this study, of the area between Lüderitz Bay and Clara Hill, provides the foundation for a detailed terrace level investigation. Regionally, twelve well-developed stillstand levels are identified, nine of which fall into the study area. These interpretations are compared with global eustatic as well as terrace and resource/reserve levels in the Lüderitz area and are found to correlate well. Sediment dynamic studies involve the use of accredited application software for wave refraction modelling, to determine the wave angle and orbital wave velocity at the seabed. Bedload velocities, required to move diamonds of specific sizes, can be empirically determined and therefore areas of diamond entrainment and deposition can be modelled and target features delineated and prioritised. These detailed interpretations provide a sound platform for evaluating diamond placer process models in the study area. By integrating both previously published and newly formulated ideas, a revised, holistic model for the formation of marine diamond placer deposits in central Namibian is postulated. The proposed model is tested by comparing it to the lateral distribution of presently defined resource/reserve areas in the Lüderitz area and shows a close correlation with most of these enriched deposits. Based on this model, a matrix for the delineation and prioritisation of marine placer deposits is developed and the best target features within the study area are identified.
KMBT_363
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This thesis analyses the legal effects on third States of the deep seabed mining regime embodied in the 1982 Law of the Sea Convention. As a general rule, a treaty can neither impose obligations, nor confer rights, upon a third State without its consent. However, the thesis argues that the legal position of the third States could be affected by the Convention's regime in one or more of the following ways: namely, the objective legal personality of the International Seabed Authority, the customary status of the common heritage principle, the concept of an "objective regime" and the concept of an obligation erga omnes. The thesis examines these concepts in turn, relying on the assumption that the Convention (including Part XI) will come into force in its present form with widespread acceptance from many States including some major industrialized States, and that some States, particularly the US, will remain non-parties to the Convention. Finally, the thesis examines the interim obligations of certain industrialized States which are signatories to the Convention in the context of the compatibility of the reciprocating States regime with the Convention's regime.

Bibliography: pages 114-116.
This study is one of three based on grab samples of macrobenthos obtained before and at different times after mining for diamonds off the coast of Namibia. The first study dealt with multivariate clustering analysis of the first samples before and after mining. The second study focused on recovery times after mining and this study is aimed at estimating the amount of stress encountered by benthic communities, for comparision with the descriptive multivariate approach. Two research areas, classified as 'northern' and 'southern' were investigated. Data were aggregated and analysed at the genus level. Graphical and statistical analyses were conducted on the data which was classified in three ways. First, on all unmined sites from the two research areas together to test for natural site-to-site variability. Secondly and thirdly, each research area (north and south) was analysed separately to test for differences between unmined and mined sites at each area. Stress levels in the community were assessed by Caswell's neutral model (the Vstatistic) and by interpretation of the value of the W-statistic (a summary statistic of the ABC curves). Correlation techniques were applied to assess if there was any relationship between the diversity indices (as indicators of the influence of disturbance on community structure) on the one hand, and the environmental indicators of disturbance (percentage gravel, sand, mud) on the other.

After the discovery of the “Minamata” disease, a neurological syndrome in humans caused by severe mercury poisoning, many studies on toxic metals in marine food webs were carried out. In the coastal marine environments, trace elements, deriving from both natural processes and human activities, contribute to marine pollution, posing potential risks to marine ecosystems. This study focuses on trace elements contamination from gold mining activities in marine sediments and in two tissues (body wall and gut) on Holothuria atra, by comparing samples collected in affected and not affected sites in North Sulawesi (Indonesia). This region is affected by industrial and artisanal gold mining activities. While industrial mines generally use cyanidation method, artisanal gold mines still employ Hg amalgamation to extract gold from ores. Mean concentrations of As, Au, Co, Cr, Cu, Hg, Ni, Pb, Sb and Zn resulted significantly higher in surface sediments at sites that receive discharge from mines than at control sites. Mean concentrations of As, Au, Cr, Hg and Ni in body walls of H. atra were significantly higher at sites that receive discharge from mines than at control sites. Mean concentrations of As, Au, Co, Cr, Cu, Hg, Pb, Sb, Sn and Zn in guts of the same specimens were significantly higher at impacted sites. Nevertheless, pollution levels varied according to the typology and oldness of mining activities. By comparing the results of this study with the few data available on trace elements contamination in H. atra, we notice that levels of trace elements in specimens of North Sulawesi are generally higher both in body walls and in guts than found previous studies, characterised by different kind of impacts. Hg resulted the most concerning element both in surface sediment and in H. atra specimens. Further studies are needed to better understand the effect of Hg and other toxic elements in marine ecosystems and in food webs of impacted areas of North Sulawesi.

Natural product drug discovery has traditionally been the corner stone of medicine having provided cures to many of today's most common diseases. In particular, antibiotics have revolutionised healthcare and extended human lifespan. However, since their introduction into the clinic, resistance to these drugs has arisen. With the number of new antibiotics being discovered in recent years declining, and fewer drugs making it past clinical trials, we have reached the point where antibiotic resistant infections have become common place and a serious threat to health and society. There is now an urgent requirement for the discovery of new antibiotics and in particular those with unexploited mode of action. This thesis details the different areas of natural product drug development from discovery through to analogue generation. In Chapter one, the history of natural products as therapeutics is explored with a particular focus on antibiotics and how resistance arises against these agents. It outlines why the discovery of new antibiotics is so important and new methods used to facilitate this search. Chapter two follows with the development of a screening platform for antibiotic induction, using the model Streptomyces; Streptomyces coleiolor M145. A variety of culture additives are explored for their ability to induce secondary metabolism production. Chapter three then details the sampling and identification of microbes from a pseudo-marine environment and their screening for their ability to produce secondary metabolites with antibiotic properties. The second half of this thesis centres on the non-ribosomal peptide echinomycin. Collaborators Aquapharm supplied the marine derived strain AQP-4895, capable of producing echinomycin. Chapter four details the establishment of AQP-4895 culturing conditions and the shift observed in production profile. Next Chapter five looks at producing echinomycin analogues through precursor directed biosynthesis. A range of halogenated quinoxaline carboxylic acids are synthesised and fed to AQP-4895, and the respective echinomycin analogues monitored by LC-MS. Chapter Six then aims to direct biosynthesis of the halogenated analogues, using mutasynthesis. Due to the lack of genetic data available surrounding the strain, an unusual approach was taken, using iPCR to create a template for homologous recombination.

>Magister Scientiae - MSc
Drug-resistant infections are a global health crisis and drastically hinder the treatment options to effectively combat disease. Today, natural products remain an important source of novel drug candidates. Micro-organisms, in addition to being a source of bioactive natural products, represent a sustainable source of these compounds. As the marine environment is largely underexplored, the oceans represent a potential source of novel NPs. This study aimed at the discovery of novel NPs from bacteria associated with novel marine invertebrate species endemic to the South African coast, including a sponge Spongia (Spongia) sp. 001RSASPN and a tunicate, Pseudodistoma africanum Millar, 1954. The methodology comprised of culture-dependent and culture-independent strategies. The former involved the isolation of bacteria associated with the invertebrate species and subsequent screening for anti-microbial activity against a panel of indicator strains including a multi-drug resistant E. coli strain. Anti-bacterial activity was detected in 6.1% and 4% of bacterial isolates from the sponge and tunicate isolates respectively. The culture-independent strategy involved the use of PCR to select bioactive strains likely to contain novel NRPS or PKS secondary metabolite pathways. An NRPS A- domain exhibiting low sequence identity (65%) to reference sequences in the NCBI database was amplified from isolate PE8-15, a strain belonging to the genus Bacillus. This predicted a novel NRPS pathway within this strain. In addition, this isolate exhibited the most diverse anti-microbial profile including anti-bacterial and anti-fungal activity (A.fumigatus ATCC 46645). Therefore, as the most promising candidate, the genome of PE8-15 was sequenced following which 10 secondary metabolite pathways including bacteriocins (5), NRPS (3), siderophore (1) and a terpene pathway were identified. The A-domain amplified from PE8-15 originated from Cluster 4, and NRPS pathway predicted to encode a lipopeptide. Lipopeptides are an important class of compounds with a range of industrial applications in the pharmaceutical, cosmetic as well as food industry. The identification of potentially novel secondary metabolite pathways from even well- studied groups of organisms demonstrates the importance of sequence-based methods in natural product discovery. Furthermore, this study highlights the South African coast as a rich source of microbial natural products and should be exploited further for drug discovery.

Thesis (M.S. in Information Technology Management)--Naval Postgraduate School, September 2003.
Thesis advisor(s): Thomas J. Housel, Glenn R. Cook. Includes bibliographical references (p. 81-82). Also available online.

Philosophiae Doctor - PhD
The World Health Organisation predicts that by the year 2050, 10 million people could die annually as a result of infections caused by multidrug resistant bacteria. Individuals with compromised immune systems, caused by underlying disease such as HIV, MTB and COVID-19, are at a greater risk. Antibacterial resistance is a global concern that demands the discovery of novel drugs. Natural products, used since ancient times to treat diseases, are the most successful source of new drug candidates with bioactivities including antibiotic, antifungal, anticancer, antiviral, immunosuppressive, anti-inflammatory and biofilm inhibition. Marine bioprospecting has contributed significantly to the discovery of novel bioactive NPs with unique structures and biological activities, superior to that of compounds from terrestrial origin. Marine invertebrate symbionts are particularly promising sources of marine NPs as the competition between microorganisms associated with invertebrates for space and nutrients is the driving force behind the production of antibiotics, which also constitute pharmaceutically relevant natural products.

Maritime transport has profound importance for the world economy. Vessels of all sizes constantly transport large numbers of passengers and goods across the sea, often under adverse operational conditions. Vessels need to exhibit high levels of reliability, availability, maintainability and safety (RAMS). However, at the same time their performance needs to be optimised ensuring the lowest possible fuel consumption with the maximum operational capacity and range without compromising RAMS. Sweating of naval assets and profitability should be maximised for the operator ensuring investment in future projects and supporting the growth of maritime transport and world economy as a whole. Vessels have been traditionally manufactured using naval steel grades such AH, DH and EH. Smaller leisure and specialised purpose vessels such as patrol boats, etc. have been built using fibre-reinforced composite (FRC) materials. This trend is gradually penetrating the market of larger commercial vessels including freight and cruise ships. However, these are still the early days and further investigation of the optimum FRC manufacturing techniques and mechanical properties together with an in-depth understanding of the damage mechanics are required before such materials can become more commonplace. This project has investigated different glass FRCs using different manufacturing techniques. Glass fibres are preferred due to their lower cost in comparison with carbon fibres. The use of carbon FRCs in maritime applications is limited to the fabrication of racing and high performance speedboat vessels. Samples manufactured under laboratory conditions have been compared with those manufactured by a shipyard. It has been seen that the in-house samples had generally superior performance. Steel-to-composite joints have also been assessed including different designs. The effect of different features in the design such as drilled holes and bolts on the mechanical performance of the manufactured samples has also been evaluated. The damage mechanisms involved during damage propagation and features causing damage initiation have been considered. Damage initiation and subsequent evolution have been monitored using acoustic emission (AE). Various signal processing approaches have been employed (manual and automatic) for optimum evaluation of the AE data obtained in a semiquantitative manner. It has been shown that AE could be applied effectively for structural health monitoring of naval structures in the field. Several factors and parameters that need to be considered during acquisition and analysis have been successfully determined. The key results of the study together with mechanical testing and characterisation of samples employed are presented in summarised form within the present thesis.

>Magister Scientiae - MSc
The continued emergence of bacterial resistance to the antibiotics currently employed to treat several diseases has added to the urgency to discover and develop novel antibiotics. It is well established that natural products have been the source of the most effective antibiotics that are currently being used to treat infectious diseases and they remain a major source for drug production. Natural products derived from marine microorganisms have received much attention in recent years due to their applications in human health. One of the biggest bottlenecks in the drug discovery pipeline is the rediscovery of known compounds. Hence, dereplication strategies such as genome sequencing, genome mining and LCMS/MS among others, are essential for unlocking novel chemistry as it directs compound discovery away from previously described compounds. In this study, the genome of a marine microorganism, Thalassomonas viridans XOM25T was mined and its antimicrobial activity was assessed against a range of microorganisms. Genome sequencing data revealed that T. viridans is a novel bacterium with an average nucleotide identity of 81% to its closest relative T. actiniarum. Furthermore, genome mining data revealed that 20% of the genome was committed to secondary metabolisms and that the pathways were highly novel at a sequence level. To our knowledge, this species has not previously been exploited for its antimicrobial activity. Hence, the aim of this study was to screen for bioactivity and identify the biosynthetic gene/s responsible for the observed bioactivity in T. viridans using a bioassay-and-genome- guided isolation approach to assess the bioactive agent. The bioassay-guided fractionation approach coupled to LCMS/MS led to the identification of a novel antimicrobial protein, TVP1. Bioinformatic analyses showed that TVP1 is a novel antimicrobial protein that is found in the tail region of a prophage in the T. viridans genome. Phage-derived proteins have previously been shown to induce larval settlement in some marine invertebrates. Since the mechanism of action of TVP1 remains unknown, it remains a speculation whether it may offer a similar function. More research is required to determine the biotechnological application and the role of TVP1 in its host and natural environment.

>Magister Scientiae - MSc
The high rate of rediscovery of known compounds has led to a decline in the discovery of novel natural products. The high biodiversity of organisms growing in extreme conditions such as oceans has led to the increased interest by researchers for their use as a source of novel natural products. Marine bacteria are known for their extensive biosynthetic capacity to produce diverse natural products, which are suitable for various biotechnology applications such as in agriculture, for treatment of fungal plant pathogens, and as antibiotics, for treatment of bacterial infections. This study aimed at discovering novel secondary metabolites from marine bacteria previously associated with novel marine invertebrate species endemic to the South African coast. The methodologies used in this study included a bioassay guided fractionation coupled to genome sequencing and mining. For the bioassay guided fractionation approach, the study first focused on screening marine bacteria for antimicrobial activity when cultured on 4 different media, against fungal strains previously shown to be virulent olive trunk pathogens. In parallel, the bacterial isolates with the most inhibitory activity against the fungal pathogens were also screened for antimicrobial activity against 4 indicator strains including Gram-negative Escherichia coli 1699 (E. coli), Pseudomonas putida, and Gram-positive Staphylococcus epidermidis ATCC14990, and Bacillus cereus ATCC10702. One of the marine bacterial isolates, PE6-126, showed diverse antimicrobial activity including antibacterial and antifungal activity against the tested strains. The genome sequencing data revealed that this isolate was B. cereus based on the average nucleotide identity (ANI) (>99%) to reference strains. antiSMASH analysis of the genome revealed nine predicted secondary metabolite clusters including bacteriocins (2), non-ribosomal peptide synthetase (NRPS) (2), siderophore (1), sactipeptide (1), betalactone (1), linear azol(in)e-containing peptides (LAP) - bacteriocin (1) and a terpene (1). Some of these pathways had low to no sequence similarity to known pathways, indicating the potential of these pathways to produce novel compounds. One of the pathways showed very high sequence similarity to the thuricin CD pathway in Bacillus thuringiensis. Considering that thuricin CD has been reported to have antimicrobial activity against B. cereus (ATCC1072), it was hypothesised that it could also be produced by PE6-126. However, the antimicrobial extract from PE6-126 was tested for sensitivity to proteinase K and heat treatment, which thuricin CD is known to be sensitive to. The results revealed that the antimicrobial activity was not lost after treatment, implying that a different metabolite could be responsible for the anti-B. cereus activity. In addition, PE6-126 initially displayed antimicrobial activity against a multi-drug resistant E. coli 1699, suggesting some of the antimicrobial compound/(s) produced by this strain could potentially be novel. The bioassay-guided fractionation approach coupled to Liquid Chromatography Mass Spectrometry (LC-MS) did not lead to identification of the antimicrobial compound/(s), therefore it remains a question whether the secondary metabolite pathways predicted by antiSMASH lead to the production of the active compound/(s). The results from this study showed that even well studied species have the potential to synthesize as yet undescribed compounds, based on the novelty of some of the pathways. This study highlights the importance of employing a genome-guided approach in drug discovery, as there may be many novel compounds to discover from biosynthetic pathways that have not yet been characterised. Further research is needed to identify the antimicrobial compound/(s) produced by PE6-126.

>Magister Scientiae - MSc
The high rate of rediscovery of known compounds has led to a decline in the discovery of novel natural products. The high biodiversity of organisms growing in extreme conditions such as oceans has led to the increased interest by researchers for their use as a source of novel natural products. Marine bacteria are known for their extensive biosynthetic capacity to produce diverse natural products, which are suitable for various biotechnology applications such as in agriculture, for treatment of fungal plant pathogens, and as antibiotics, for treatment of bacterial infections. This study aimed at discovering novel secondary metabolites from marine bacteria previously associated with novel marine invertebrate species endemic to the South African coast. The methodologies used in this study included a bioassay guided fractionation coupled to genome sequencing and mining. For the bioassay guided fractionation approach, the study first focused on screening marine bacteria for antimicrobial activity when cultured on 4 different media, against fungal strains previously shown to be virulent olive trunk pathogens. In parallel, the bacterial isolates with the most inhibitory activity against the fungal pathogens were also screened for antimicrobial activity against 4 indicator strains including Gram-negative Escherichia coli 1699 (E. coli), Pseudomonas putida, and Gram-positive Staphylococcus epidermidis ATCC14990, and Bacillus cereus ATCC10702. One of the marine bacterial isolates, PE6-126, showed diverse antimicrobial activity including antibacterial and antifungal activity against the tested strains. The genome sequencing data revealed that this isolate was B. cereus based on the average nucleotide identity (ANI) (>99%) to reference strains. antiSMASH analysis of the genome revealed nine predicted secondary metabolite clusters including bacteriocins (2), non-ribosomal peptide synthetase (NRPS) (2), siderophore (1), sactipeptide (1), betalactone (1), linear azol(in)e-containing peptides (LAP) - bacteriocin (1) and a terpene (1). Some of these pathways had low to no sequence similarity to known pathways, indicating the potential of these pathways to produce novel compounds. One of the pathways showed very high sequence similarity to the thuricin CD pathway in Bacillus thuringiensis. Considering that thuricin CD has been reported to have antimicrobial activity against B. cereus (ATCC1072), it was hypothesised that it could also be produced by PE6-126. However, the antimicrobial extract from PE6-126 was tested for sensitivity to proteinase K and heat treatment, which thuricin CD is known to be sensitive to. The results revealed that the antimicrobial activity was not lost after treatment, implying that a different metabolite could be responsible for the anti-B. cereusactivity. In addition, PE6-126 initially displayed antimicrobial activity against a multi-drug resistant E. coli 1699, suggesting some of the antimicrobial compound/(s) produced by this strain could potentially be novel. The bioassay-guided fractionation approach coupled to Liquid Chromatography Mass Spectrometry (LC-MS) did not lead to identification of the antimicrobial compound/(s), therefore it remains a question whether the secondary metabolite pathways predicted by antiSMASH lead to the production of the active compound/(s).The results from this study showed that even well studied species have the potential to synthesize as yet undescribed compounds, based on the novelty of some of the pathways. This study highlights the importance of employing a genome-guided approach in drug discovery, as there may be many novel compounds to discover from biosynthetic pathways that have not yet been characterised. Further research is needed to identify the antimicrobial compound/(s) produced by PE6-126.

The Ming maritime prohibition policy (1371-1568) reversed the maritime policies of the preceeding Tang, Song and Yuan dynasties. It was maintained for two centuries at considerable costs, but in 1568 was eventually abolished. There has not yet been a satisfactory analysis of this policy, which addresses the issues of why it was introduced, why it was maintained for so long, and why, eventually, it was overturned. This thesis takes a new approach to understanding these issues. Instead of focusing solely on external factors, such as the need for defence against Japanese piracy, it focuses on the internal situation of Ming society, and instead of focusing on the policy as an epiphenomenon it considers the social foundation for Ming foreign trade policy. In this thesis, the maritime policy is treated as a product of the social, economic and political configurations of Ming China. It argues that the establishment of the policy, its maintenance and abolition reflect two different socio-economic structures, hence two different political bases. The suppression of commerce during the early Ming reflected the interests of the political elite that came to power with the establishment of the new dynasty. The abolition of the maritime prohibition reflected the way the commercialisation of the socio-economic landscape brought a new political élite to power, in which many more officials with merchant-family backgrounds participated in the policymaking process. Commercialisation drove the social re-configuration and reshaped the political landscape, and this resulted in the late Ming years in an overturn of many of the policies that had been introduced at the beginning of the dynasty. Such a structural approach allows us to gain a richer understanding of the maritime prohibition policy.

This project focuses on the use of sponge genetic transcripts in the form of expressed sequence tags (ESTs) readily available in Genbank to search for novel genes using bioinformatics analysis tools. Marine sponge species are known to house a diversity of marine microbes and are known as the ‘living fossils’ of the animal kingdom because of the large number of ancient genes they house. Genomic mining can be a useful tool in discovering these orthologous genes. This study utilized the techniques of genomic mining of 11 previously described sponge species transcripts. The results of this study provide a better understanding of the genomic structure of the organisms studied by creating a more detailed genetic map and examining a specific environmental snapshot of the genes in each sponge. Novel methods for dissecting beneficial information from large scale data sets available in genomic libraries utilizing bioinformatics search tool MGRAST were examined. The results of this study indicate that sponges house numerous genes that are likely to be evolutionary predecessors of genes in higher eukaryotes. Support was also given to the notion that microbial communities play a role in metabolic pathways of sponges.

Dag Wellander: Meaning – memory: oblivion. A reading of Birgitta Trotzig’s The mud kings daughter. Master of Arts paper. Written in Swedish. 115 pp. Department of Literature and History of Ideas, Stockholm University, SE – 106 91 Stockholm

The purpose of the paper is to treat one question, including the consequences of it’s answer, the question if The mud kings daughter is a text that has meaning. The question is in a first series of steps being approached by the way of scrutinizing the meaning found in the text in accordance with the methodology applied by those four dissertations that are available on the subject, i.e. on The mud kings daughter. These examinations do not find that the alleged forms of meaning stated by the dissertations is being produced by the text. On the contrary striking similarities is being found between these alleged forms of meaning on the one hand, and on the other the unfounded, disambiguated meaning that, according to Shoshana Felman, Freudian and anti-Freudian critics alike, have said is to be found in Henry James’ short novel The Turn of the Screw. In a following series of steps – some of which are being taken on Jacques Derrida’s advice – the rhetorical functioning of the textual ambiguity is observed and often found to be enchanting, whereupon the rhetorical necessity of the textual ambiguity is found to be affliction.

This split between the rhetorical functioning of the textual ambiguity as rather enchanting, and the rhetorical necessity of the textual ambiguity being affliction, is then treated as something that hardly could be understood, and, accordingly, as something that might be understood as something that could not be understood. The idea is being put in that this split could be thought of as an inversion of oblivion into a living memory of a forgotten reading impression, an idea that is being inspired by the inversion of oblivion into a living memory in Marcel Proust’s In Search of Lost Time.

Keywords: Birgitta Trotzig, Shoshana Felman, Jacques Derrida, Marcel Proust, meaning, ambiguity, memory, oblivion.

L’objectif de cette thèse est d’analyser l’évolution d’une province à mini-bassins salifères, en s’appuyant sur l’étude des variations spatiales et temporelles de faciès, d’épaisseurs ainsi que des géométries développées lors du fluage des évaporites. L’exemple naturel investigué est le bassin de Sivas, situé sur le Plateau central Anatolien en Turquie. Ce bassin d’avant-pays enregistre à l’Oligo-Miocène la formation de nombreux mini-bassins secondaires au-dessus d’un niveau d’évaporites allochtones. A partir d’une cartographie et d’une description détaillées des séries sédimentaires accumulées dans les mini-bassins de Sivas, nous avons pu identifier trois ensembles tectono-sédimentaires cohérents :• la formation Karayün (Oligocène moyen à supérieur), constituée de dépôts de playa-lake, fluviatile en tresse et fluvio-lacustre, interprétée comme proche d’un système fluviatile en distributaires ;• la formation Karacaören (Oligocène supérieur, Miocène inférieur), interprétée comme une série alternante entre une rampe mixte deltaïque et carbonatée, et des dépôts de lagune et de plaine côtière ;• la formation de Benlikaya (Miocène), constituée de dépôts de cônes alluviaux, fluviatiles en tresse et playa-lake, interprétée également comme proche d’un système fluviatile en distributaires.Malgré de nombreuses variations de l’épaisseur et de la succession sédimentaire inter- et intra-bassins, des unités stratigraphiques équivalentes ont pu être déterminées à partir de l’identification de lignes isochrones marquant des changements de tendances. Nous avons montré alors que le système sédimentaire de chacun des mini-bassins est contrôlé au premier ordre par trois facteurs interdépendants, à savoir :• l’accommodation par halocinèse, provoquant la surrection des diapirs et des murs périphériques lors de la subsidence du mini-bassin. Ce fluage des évaporites produit des variations intra-basinales de faciès et d’épaisseurs, associées à des déformations syn-sédimentaires en bordure de mini-bassins. À plus grande échelle, ces objets salifères produisent une compartimentation inter-bassins des environnements de dépôts.• le taux d’accumulation sédimentaire, qui influence la faciologie et l’architecture stratigraphique des dépôts.• l’accommodation régionale, lié à la flexure du bassin, à l’origine du dépôt de série isopaques pouvant recouvrir les diapirs et finalement masquer l’influence salifère.À ces paramètres communs aux provinces salifères, nous ajoutons, l’influence des contraintes tectoniques compressives qui modifient les rétroactions entres ces facteurs
The aim of this thesis is to investigate the development of a salt-related mini-basin province, based on spatial and temporal changes in the facies assemblages, stratigraphic architecture and thicknesses, as well as stratal structures related to salt movement. The study area is the Sivas Basin, located in the Central Anatolian Plateau of Turkey, which is a foreland basin that records the formation during the Oligo-Miocene of numerous secondary mini-basins on top of an allochthonous evaporite canopy. Through detailed mapping of the Sivas mini-basin province, we provide a new and comprehensive description of the stratigraphic vertical succession including:• the Karayün Fm (Mid to upper Oligocene), comprising playa-lake, fluvial braided and fluvio-lacustrine deposits, and interpreted as a large distributive fluvial system;• the Karacaören Fm (Up. Oligocene to Low. Miocene), comprising two main sub-environments: mixed deltaic and carbonate ramp, alternating with coastal plain and restricted lagoon;• the Benlikaya Fm (Miocene), comprising alluvial fan, fluvial braided and playa-lake deposits interpreted also as a large distributive fluvial system;Within neighbouring minibasins and despite a similar vertical stratigraphic succession, variations are observed in stratigraphic units of equivalent age within and between minibasins. At the first order, we have defined three factors that dictate the pattern of mini-basin filling:• salt-induced accommodation producing local faciologic and stratigraphic thickness changes, and halokinetic structures along mini-basin borders. At larger scale, salt structures result in a compartmentalization of facies between basins.• The sediment supply rate, which affects facies assemblage and stratigraphic architecture.• Tectonically driven regional accommodation attributed to the foreland flexure, inducing the deposition of relatively isopachous series draping and finally obscuring the salt topography.In addition, these three factors are largely influenced by shortening during the evolution of the Sivas fold-and-thrust-belt

This thesis provides a comparative analysis of the environmental values present in Ghana’s and Senegal’s coastal regions, and the implications that those have for the surrounding environment. The countries approaches to urban farming, mining and oil and gas extraction, fishing, marine debris and municipal waste management are assessed in order to reach a greater understanding of these environmental issues. In undertaking this thesis, I attempted to draw a correlation between the handling of these issues and how people perceive their environment. Through the comparison of environmental degradation and the level of effort to achieve a more sustainable developmental framework in both countries, I draw examples from successes in Senegal’s coastal management framework to recommend appropriate environmental policy for the Greater Accra Region.

Este estudo apresenta ao Departamento de Engenharia de Minas e Petróleo (PMI) da Escola Politécnica da USP, e também a toda a sociedade, a importância que os oceanos têm com relação às suas riquezas minerais. Pretende ainda mostrar a grande responsabilidade que um empreendimento mineiro no fundo do mar precisa ter, com relação aos impactos ambientais, sendo possível minerar em regiões profundas no oceano promovendo a sustentabilidade. A ideia da mineração oceânica/submarina está ainda sendo amadurecida, este é o momento adequado para se propor metodologias de trabalho submarino sustentáveis; mitigar seus impactos. Este trabalho abrange o tema de maneira ampla, abordando o aspecto histórico, legal, ambiental, bem como questões técnicas de engenharia de minas, como sondagem submarina, caracterização tecnológica, lavra submarina, beneficiamento de minério oceânico e descarte de rejeitos. O trabalho apresenta os passos e resultados de um caso real de exploração oceânica. Trata-se de um estudo para viabilizar economicamente a extração e o beneficiamento de areia marinha, para fins industriais, proveniente da Baía de Guanabara (RJ). O trabalho apresenta desde o planejamento da amostragem no fundo do mar, execução destes trabalhos, caracterização tecnológica, simulação de processo e estudos específicos do uso industrial da areia após beneficiamento. Apresenta ainda uma proposta de rota de processo para a areia marinha e questões ligadas à lavra e ao descarte de rejeitos.
This study aims to show the importance of the oceans and its mineral wealth. It intends also to show the big responsibility that an undersea enterprise must bear concerning the environmental impact. It shows the availability to minein a sustainable way in the bottom of the sea. The undersea mining is still raising, now is the auspicious time to suggest sustainably submarine work methodologies; to mitigate its impact. This study covers the historic, legal and environmental aspects, as well as technical issues of mining engineering such as undersea survey, process mineralogy, undersea mining, mineral beneficiation for marine ores and tailings disposal. This study presents the steps and results of a real subsea exploration case. The studied ore is a marine sand from Baía de Guanabara (Rio de Janeiro), aiming to supply industrial market. This is a feasibility and technical study to show how to exploit and process this kind of ore. The study shows the undersea survey planning and its execution, the process mineralogy planning and its results, process simulation and some specific studies to industrial uses for this sand, after its beneficiation. Besides these subjects, the study proposes an industrial process route for process and tailings disposal.

Ad oggi esistono fortissime evidenze che le attività antropiche stanno causando rapidi cambiamenti alle dinamiche degli ecosistemi marini. Molti di questi cambiamenti stanno già avvenendo negli oceani del nostro pianeta, con potenziali conseguenze negative nelle prossime decadi. La Direttiva Quadro sulla Strategia Marine (MSFD, 200856/EU), approvata nel 2008 dal Consiglio Europeo e dal Parlamento Europeo, richiede agli Stati Membri di fornire informazioni sullo stato di salute dei mari di loro pertinenza " stabilendo un quadro per le azioni comunitarie nel campo delle politiche ambientali marine", e le relative strategie da adottare per migliorare la qualità degli ecosistemi marini al fine di assicurare lo sfruttamento delle risorse anche alle generazioni future. L'obiettivo principale di questa tesi di dottorato è quello di identificare pattern utili alla definizione del buono stato ambientale (GES) come richiesto dalla Direttive Europea per i descrittori 5 (eutrofizzazione) e 7 (alterazioni idrografiche) della Direttiva, attraverso l'integrazione di dati fisici e biologici misurati in situ, dati da satellite e output di modelli revisionali a diverse scale spazio temporali. Al fine di comprende meglio anche le dinamiche a piccola scala, sono stati elaborati dati relativi alla portata dei fiumi e al carico dei nutrienti che si immette nelle zone costiere della Regione Marche e il loro impatto sulle acque marine costiere. I risultati di questo studio hanno evidenziato nel periodo preso in esame cambiamenti differenti a grande e piccola scala. Se a scala di bacino il mare Adriatico sta subendo negli ultimi anni un riscaldamento delle acque, con corrispondente aumento della biomassa fitoplantonica, e un innalzamento del valori di salinità, a scala locale le dinamiche marine sembrano più influenzate dalle dinamiche fluviali. Questi risultati permettono di definire delle linee guida necessarie per sviluppare soglie e determinare adeguati standard per le acque del Mare Adriatico, oltre a migliorare la conoscenza della variabilità temporale sia del bacino adriatico sia a scala locale, dove la forzante principale è rappresentata dalle dinamiche fluviali.
There are growing evidence that human activities together with climate change are driving profound changes of marine ecosystems with important repercussions on the goods and services they provide for human wellbeing. The Marine Strategy Framework Directive (MSFD, 2008/56/EU), approved in 2008 by the European Parliament and transposed at Italian level in 2010 (Legislative Decree 190/2010), requires Member States to provide information on marine environmental status and to take the necessary measures to achieve or maintain Good Environmental Status (GES) of the marine environment by the year 2020. The main objective of this PhD thesis is to improve knowledge on the trophic and thermohaline conditions of the Adriatic Sea related to descriptors 5 (eutrophication) and 7 (hydrographic alterations) which are included in the MSFD and used along with other 9 descriptors for the assessment of GES, through the use and integration of outputs of predictive models, physical and biological data measured in situ and satellite data analyzed at different spatial and temporal scales. In order to better clarify dynamics occurring at local scale, data on thermohaline and biogeochemical characteristics of coastal waters of Marche Region have been acquired along with information on the river outflows and nutrient load. Results of this study highlight that during the investigated period temporal patterns occurring at the basin scale are different than those observed at local scale. In particular, while at the basin an increase of water temperature and salinity together with an increase of the phytoplankton biomass have been observed in the last 10-15 years, at a local scale patterns of thermohaline and biogeochemical characteristics on a decade are generally opposite and influenced by the river dynamics. Overall results of this study on the one hand highlight the importance of using integrated tools and approaches for the study of the thermohaline and biogeochemical characteristics at different spatial scales (Adriatic basin vs. local scale), and on the other represent an important benchmark for a better understanding of the functioning of the Adriatic Sea and the potential changes that could affect the achievement of GES and its maintenance over time.

El objetivo de la Tesis es obtener una visión de la situación actual de la laguna costera del Mar Menor en relación con la contaminación por metales pesados procedentes de actividades mineras mediante el empleo de herramientas ecotoxicológicas. Comienza con el estudio de la entrada de residuos mineros en el ecosistema, su distribución en las aguas de la laguna así como los efectos tóxicos asociados. Continua valorando la biodisponibilidad de los metales contenidos en los sedimentos lagunares mediante pruebas de toxicidad y de bioacumulación; sus efectos en praderas de fanerógamas y comunidades de invertebrados asociados, para continuar determinando la potencial transferencia trófica de metales en las redes alimenticias lagunares y su posible biomagnificación. Finalmente, la Tesis concluye determinando la utilidad de indicadores propuestos para su aplicación en la Directiva Europea Marco del Agua cuando son aplicados a dos ecosistemas acuáticos contaminados por contaminación tóxica (metales pesados).
The objective of the Thesis is to determine the present situation of the Mar Menor coastal lagoon in relation with the contamination caused by heavy metals coming from old mining activities through the use of ecotoxicological tools. It begins with the study of the entrance of mining wastes in the lagoon ecosystem, its distribution in the lagoon waters as well as their toxic effects. It continues assessing the bioavailability of metals contained in sediments of the lagoon by means of bioaccumulation studies and toxicity tests; their possible deleterious effects on marine phanerogams and associated invertebrate communities. It also determines the potential trophic transfer of metals in trophic webs of the lagoon studying the possible biomagnification of metals. Finally, the Thesis concludes determining the utility of some indicators proposed for their application in the European Water Framework Directive when they are applied to aquatic ecosystems impacted by toxic contamination (heavy metals).

La caractérisation de sources acoustiques a pour but de décrire des émetteurs sonores à travers certains paramètres comme leur localisation dans l'espace, le niveau sonore qu'ils produisent ou encore leur identification grâce à leur signature acoustique. Dans cette thèse, l'objectif est d'obtenir certains de ces trois paramètres dans deux cas d'application concrets, pour des sources situées en champ lointain et grâce à des antennes acoustiques. La première application concerne l'impact acoustique de la prospection minière sous-marine par grands fonds dans le cadre du projet FUI Abysound. Au sein du projet, la thèse cherche à caractériser les machines excavatrices placées sur les fonds marins en obtenant leur localisation et leur niveau sonore. Une première phase de design a abouti à la construction d'une antenne conique de 3 m. En s'appuyant ensuite sur les données issues de deux campagnes expérimentales menées en mer Méditerranée avec cette antenne, la méthode haute-résolution MUSIC localise précisément les sources mises en oeuvre, qu'elles soient mobiles et à plus de 600 m de l'antenne, ou immergées par 700 m de fond. Leur niveau sonore est ensuite estimé par formation de voies, et les niveaux attendus sont retrouvés pour des signaux monochromatiques ou à large bande. Dans la seconde application, une procédure complète pour la localisation et l'identification de drones est proposée pour la protection de sites sensibles. Elle combine traitement d'antenne et apprentissage statistique en s'articulant autour de trois étapes clés : la localisation, la focalisation et l'identification. La méthode MUSIC localise à nouveau les sources acoustiques présentes autour de l'antenne industrielle utilisée, puis la focalisation reconstruit le signal temporel de chacune, et un modèle SVM les identifie comme drone ou non. Les validations expérimentales, en intérieur comme en extérieur, constituent une contribution importante de ce travail de thèse. Les données acquises montrent entre autres que la procédure localise des drones à 3° près en extérieur, les détecte à 99 %, ou encore les identifie en présence d'une source perturbatrice plus puissante
Acoustic sources characterization aims to describe sound emitters through some parameters like their localization in space, the sound level they produce or their identification thanks to their acoustic signature. In this thesis, the objective is to obtain some of these parameters in two industrial application cases, for sources located in far-field and by the use of acoustic arrays. The first application concerns deep-sea mining acoustic impact in the context of Abysound FUI project. Within it, the thesis searches to characterize the excavation machine located on the seabed by assessing their localization and their sound level. First, a design phase has led to the construction of a 3 m size acoustic array. Then, using data from two experimental campaigns conducted in the Mediterranean Sea with this array, the high-resolution method MUSIC accurately localizes the used acoustic sources, either mobile and more than 600 m away from the array, or immersed by 700 m depth. Their sound level is then estimated by beamforming, and the expected levels are verified for monochromatic or wideband signals. In the second application, a complete procedure for the localization and the identification of drones is proposed to protect sensitive areas. It combines array processing and machine learning through three key steps: localization, focalization, and identification. MUSIC localizes again nearby acoustic sources around the industrial array used, then focalization reconstructs each temporal signal, and a SVM model identifies them as drone or not. Experimental validations, inside and outside, establish an important contribution of this thesis work. Acquired data show for instance that the procedure localizes drones with 3° accuracy outside, detects them at 99 %, or identifies them despite the presence of a more powerful source

Considering the recent introduction of restrictions on air pollutant onboard ships and the increasing interest towards more energy efficient naval transportation, an effort is made in the present thesis to assess the possible design of a novel engine unit. More specifically, in the current regulation context, Gas Turbines are a promising alternative to current diesel engines, thanks to lighter fuel requirements, low NOx pollutants and the potential to run in combined cycle architecture with cogeneration strategies. While their application has shown clear advantages and drawbacks on large ships, there seems to be little if no data concerning smaller units. The present work tries to assess the possible design of a radial turbine for an engine to be employed onboard ships as a Mini Gas Turbine, i.e. up to 5 MW output power, taking into account cycle, aerodynamic and structural design. To this purpose, a platform was built in Ansys Workbench to perform Computational Fluid Dynamics and thermo-mechanical Finite Element simulations aimed to design and optimize such a novel radial turbine.

Marine diamond mining as practiced on the west coast of southern Africa is considered to be a high-risk venture. Investment decisions can be eased by using simulations to model likely outcomes. This study utilised Net Present Value (NPV) to measure the impact of sampling and grade estimation decisions on a marine diamond mining project. It focused on aspects such as the accurate determination of geological conditions, the influence of the degree of error in the geostatistical estimation process, sample density and sample support size. A simulated deposit was constructed that could be sampled using various parameters to measure the sensitivity of NPV. Various scenarios and their related NPV's showed that exploration costs have a small impact on a project in comparison with other cost aspects. However, the decisions made in the exploration process do have a significant impact on the NPV of a project. Inaccuracy in recovery efficiency and mining rate prediction, lead to a decline in NPV. Misfitting the semi-variogram model had a smaller impact on the NPV than the other scenarios investigated, but the importance of reflecting the true variance of the deposit in financial terms was evident. Finding the optimal sampling density and support size do have a positive effect on NPV. It is believed that the method demonstrated in this study can be used as a guide to add value in the selection of optimal parameters when planning exploration campaigns in marine mining projects. AFRIKAANS : Mariene diamant ontginning, soos beoefen aan die weskus van suidelike Afrika, is 'n hoe risiko ondememing. Beleggings besluite kan vergemaklik word deur simulasies te gebruik om moonlike resultate te modeleer. Hierdie studie het Netto Huidige Waarde (NHW) gebruik om die impak van steekproefneming en skattings besluite op 'n mariene diamantontginning projek te meet. Aspekte soos die korrekte bepaling van geologiese kondisies, die invloed van foute in die geostatistiese skattings proses, steekproef spasieering en steekproef grootte, is ondersoek. 'n Afsetting is met 'n simulasie geskep. Steekproewe is dan geneem van die afsetting om NHW sensitiwiteit teenoor verskeie parameters te meet. Verskeie scenarios en hulle verwante NHW's het gewys dat, in vergelyking met ander kostes, eksplorasie kostes 'n klein impak op 'n projek het. In teenstelling hiermee is die impak van besluite wat geneem word in die eksplorasie fase groot. Onakkurate herwinnings effektiwiteit en ontginningstempo skattings lei tot 'n afname in NHW. Swak modelering van die semi-variogram het 'n kleiner invloed op NHW, maar die belangrikeid daarvan om die ware variansie van die afsetting te reflekteer, was duidelik in finansieele terme. Die gebruik van optimale steekproef spasieering en grootte het 'n positiewe impak op NHW. Die metode wat gedemonstreer word in hierdie studie kan gebruik word as 'n gids om optimale parameters te selekteer wanneer eksplorasie programme beplan word vir mariene diamantontginnings projekte. Copyright
Dissertation (MSc)--University of Pretoria, 2012.
Geology
unrestricted

La mine Marban est située dans le sud de la ceinture de roches vertes de l'Abitibi, dans le secteur minier de Val d'Or-Malartic. Les roches encaissantes de la mine sont une alternance d'unités mafiques et ultramafiques de la Formation de Jacola. La mine Marban a produit 1 983 112 tonnes à 5.27 g/t d'or (Au) pour un total de 330 027 onces entre 1961 et 1974. Le minerai aurifère de la mine Marban est encaissé par une unité mafique, principalement dans sa partie cisaillée et plissée. Le gisement est situé dans la zone de cisaillement Marbenite, orientée est-sud-est -ouest-nord-ouest. La géologie locale montre une alternance d'unités mafiques et ultramafiques cisaillées et plissées, recoupées par des dykes dioritiques et gabbroïques ainsi que par des intrusions granodioritiques dans la partie nord du secteur. De récents forages carottés ont permis d'établir la géométrie 3D des unités présentes. Les unités mafiques et ultramafiques forment quatre plis isoclinaux serrés dont le plan axial est généralement orienté est-sud est/ouest-nord ouest, et incliné vers le nord de 45° à 60°. Il semble donc que la minéralisation exploitée à la mine Marban soit logée dans les charnières des plis antiformes développés dans une unité de roches mafiques, à proximité du contact avec une unité de roches ultramafiques, ou le long du plan axial de ces plis. L'étude des figures de déformation des roches de Marban montrent que le secteur a subit des déformations cassantes et ductiles, provoquées par l'orogénie Kénoréenne. La forme des minéraux métalliques dont celle des grains d'or suggère que la minéralisation a subit au moins une partie de ces déformations. Il semble donc que le gisement de Marban soit précoce par rapport aux évènements associés à l'orogénie Kénoréenne. D'après ces éléments, l'âge de précipitation de l'or de Marban est pré-à syn-tectonique. Une étude métallogénique et minéralogique des carottes de sondage a permis de déterminer qu'une grande partie de la minéralisation aurifère récemment découverte dans les forages se concentre le long du contact entre les unités de roches mafiques et ultramafiques. On y a par exemple obtenu des teneurs de 6.08 g/t Au sur 6.5 m, et de 2,44 g/t Au sur 9 m sur les flancs du pli antiforme contenant le gisement de la mine Marban. D'autre part, des mesures de la susceptibilité magnétique des lithologies recoupées par les sondages font apparaître une diminution de la teneur en magnétite des roches ultramafiques à l'approche du contact avec les roches mafiques adjacentes. L'hypothèse de la mise en place de l'or est que des fluides enrichis en CO₂ et en complexes bisulfurés porteurs d'or sont associés à une altération des différentes lithologies de Marban, forçant ainsi des échanges métasomatiques. L'altération des roches ultramafiques (komatiites) en roches à talc-carbonate aurait provoqué la transformation de la magnétite en pyrite par interaction avec des fluides riches en CO₂ et en soufre réduit. Des cristaux de magnétite corrodés par de la pyrite ont notamment été observés. Dans ce type d'environnement, la cristallisation de la pyrite entraîne indirectement la précipitation de l'or transporté par les fluides. La minéralisation aurifère apparaît donc comme le produit d'une altération métasomatique entre des unités de composition contrastée, mafique-ultramafique. Cette altération se manifeste souvent sous forme d'auréoles aurifères enrichies en chlorite, carbonates, et pyrite le long des contacts entre les différentes lithologies. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Abitibi, Formation de Jacola, Mine Marban, Minéralisation aurifère, Roches basaltiques, Roches ultramafiques, Altération métasomatique, Complexes bisulfurés, Fluides, Pyrite, Magnétite, Chlorites.

La governance degli oceani e dei relativi fondali si colloca tra gli sviluppi più contemporanei e significativi del diritto internazionale del mare. Il presente elaborato offre uno studio su uno degli attori internazionali chiamati alla cooperazione ed al coordinamento per la tutela degli ecosistemi oltre la giurisdizione nazionale. La ricerca si concentra, infatti, su una delle tre istituzioni create dalla Convenzione delle Nazioni Unite sul diritto del mare (UNCLOS), ovverosia l’Autorità internazionale dei fondali marini (l’Autorità). La scelta del soggetto è dettata dall’evidenza che l’Autorità – unica organizzazione con un mandato esplicitamente esteso alla tutela dell’Area – è stata a lungo considerata alla periferia del diritto internazionale e, pertanto, oggetto di sporadica e spesso incompleta analisi in riferimento al suo contributo alla tutela ambientale delle aree oltre la giurisdizione nazionale. Dal 2021, tuttavia, essa è entrata in una nuova fase della sua esistenza, che la colloca sul proscenio della governance degli oceani. Invero, con una lettera datata 25 giugno 2021 indirizzata al Consiglio – l’organo esecutivo dell’Autorità – il Presidente della Repubblica di Nauru ha dichiarato che la compagnia Nauru Ocean Resources Inc. sponsorizzata dal paese intende procedere all’estrazione dei noduli di manganese dell’Area. Ai sensi dell’Accordo di attuazione della Parte XI dell’UNCLOS, il Consiglio dovrà concludere entro due anni l’adozione di norme, regolamenti e procedure per facilitare l’approvazione di un piano di lavoro per lo sfruttamento minerario. Essa dovrà, in particolare, mettere a punto un robusto ed olistico regolamento, che consenta di contemperare la crescente richiesta di minerali con il più elevato livello di tutela dell’ambiente possibile, prima che le operazioni estrattive abbiano inizio su scala commerciale. Nonostante l’ampiezza del mandato ambientale goduto dall’Autorità ai sensi dell’articolo 145 dell’UNCLOS, lo studio mostrerà che in oltre 25 anni di attività essa ha elaborato norme e regolamenti solo in relazione alle attività minerarie e non, più in generale, a tutela dell’Area dagli impatti delle attività antropogeniche lato sensu. Si evidenzia, dunque, nei fondali come nella colonna d’acqua oltre la giurisdizione nazionale, un fenomeno di frammentazione della governance ambientale, evidentemente contraria a quell’approccio integrato, sempre più ritenuto fondamentale per la tutela dell’alto mare e dell’Area. Diverse sono le conseguenze di tale status quo. Si tratta, in particolare, della mancanza di principi generali condivisi per la tutela delle aree oltre la giurisdizione nazionale, ma anche dell’assenza di un quadro globale per l’istituzione di aree marine protette e per le valutazioni di impatto ambientale. Vi si aggiungono, poi, le incertezze connesse allo status giuridico delle risorse marine genetiche e l’incostante integrazione di considerazioni connesse alla tutela dell’ambiente marino e alla conservazione della biodiversità nel processo decisionale delle organizzazioni internazionali, settoriali e regionali, esistenti. Rispetto ad un siffatto quadro, che il negoziando terzo accordo di attuazione dell’UNCLOS si prefigge di modificare, questa ricerca ha indagato il ruolo dell’Autorità rispetto ad elementi selezionati del package deal, su cui si fonda tale nuovo trattato. Il presente elaborato ha, dunque, concluso che l’Autorità costituisce un attore indispensabile e dotato di competenze già in parte estese a ciascuno degli ambiti presi in considerazione dal terzo accordo di attuazione, ed ha evidenziato il suo possibile ruolo nel rafforzamento della governance delle aree oltre la giurisdizione nazionale. Benché l’accordo sulla conservazione ed uso sostenibile della biodiversità troverà applicazione tanto all’Area quanto all’alto mare, per i due spazi marini l’UNCLOS prevede norme e principi diversi che non appare semplice conciliare. Ciò, in particolare, costituisce un ostacolo a rendere l’Autorità la struttura istituzionale a supporto dell’implementazione del nuovo trattato, come auspicato da una certa dottrina e da un considerevole numero di Stati. La riluttanza verso una tale opzione risiede in un timore già espresso durante la Terza conferenza di codificazione del diritto del mare. Si tratta, cioè, del verificarsi di quel fenomeno, ribattezzato in dottrina come creeping common heritage, consistente nell’erosione della libertà dei mari a favore del principio del patrimonio comune dell’umanità, con il conseguente «spill over effect on other areas of the law of the sea». A 40 anni dall’apertura alla firma dell’UNCLOS, non si è, però, sviluppata alcuna prassi in tal senso: non vi sono, pertanto, elementi che inducano a ritenere che servirsi, per l’attuazione del nuovo accordo, di una moderna organizzazione a carattere quasi universale, certamente non più alla periferia del diritto internazionale e che pone al centro della sua attività un forte accento sulla tutela dell’ambiente marino, possa avere alcun effetto di destabilizzazione rispetto ai delicati equilibri di sovranità e giurisdizione sanciti dall’UNCLOS. Quel che è certo è che dall’analisi del mandato dell’Autorità e degli sviluppi più recenti (e prossimi) in tema di tutela delle aree oltre la giurisdizione nazionale è emersa l’inadeguatezza di un approccio rigidamente zonale alla protezione dell’ambiente marino. Ciò non implica, come pure da alcuni sostenuto, un ripensamento dell’intera UNCLOS, che resta un monumentale traguardo del moderno diritto internazionale e che ha efficacemente retto all’urto del tempo, ma l’identificazione di schemi cooperativi sostanziali – e non più solo formali – tra i vari attori coinvolti nella governance degli oceani. Dal suo canto, l’Autorità si sta approcciando a tale sfida portando a completamento un robusto sistema di tutela dell’ambiente marino prima che le attività di sfruttamento minerario da essa regolate avranno luogo. In questo senso, i risultati che l’Autorità riuscirà a raggiungere nel prossimo biennio saranno di indubbio rilievo e contribuiranno a rafforzare la governance ambientale delle aree oltre la giurisdizione nazionale. Tuttavia, fino a che non si costituirà, per il tramite del nuovo accordo, un rapporto cooperativo istituzionalizzato tra le organizzazioni internazionali attive su base settoriale, regionale e globale, il gap nella tutela dell’Area e dell’alto mare permarrà ed i preoccupanti trend sullo stato di salute dell’ambiente marino oltre la giurisdizione nazionale non saranno destinati a migliorare.

Text in English with abstracts and keywords in English, Afrikaans, Sepedi and Sesotho
Soil and other geological materials found on the crust of the Earth are known to be rich in naturally occurring silicate minerals. Asbestos is one of the fibrous silicate minerals that was mined predominantly in some regions of Limpopo, Mpumalanga and Northern Cape provinces in South Africa. Despite the cessation of asbestos mining due to associated human health effects in 2002, there is still a concern about possible environmental exposure to asbestos fibres. A single asbestos fibre is made of millions of microscopic needle-like fibrils which break easily to produce inhalable size fractions that are reported to cause lung diseases. The main source of asbestos fibres in former mining areas is asbestos mine dumps and asbestos contaminated surface soil. Asbestos mine dumps in Limpopo Province are partially rehabilitated, while in Mpumalanga Province they are not rehabilitated and all these dumps are now under the care of government because the original owners have abandoned them. The settleable dust is the first indicator of airborne dust pollution and the rate of settleable dust rates was used to select the sites to be monitored. A pilot study was conducted to test the performance of the ASTMD1739:1998 and ASTM D 1739:1970 methods. The method was further modified and optimized to measure asbestos load in settleable dust samples. A total ten sites located around vulnerable human settlements that are in close proximity to the abandoned asbestos mine dumps were chosen in Mpumalanga and Limpopo Provinces respectively. Airborne, surface and trapped dust samples were collected once a month around human settlements that are in close proximity to the abandoned asbestos mine dumps from April 2016 to June 2017. Airborne dust samples were collected using the official settleable dust monitoring method, the general particulate matter E-sampler and the official asbestos Air-Con 2 sampler. Surface dust was collected outdoors around the settleable dust collection units using a brush and dust pan and was stored in labeled zipper bags made of plastic material. Trapped dust samples were collected using sticky tape both indoors and outdoors around the window panes, on surfaces of furniture and on windscreens of old cars and were stored in labeled closed containers. Surface soil samples were also screened with the hand held asbestos analyser before collection. The samples were extensively and carefully prepared and handled to avoid or minimize cross contamination using standard laboratory methods and were analysed using calibrated analytical instruments. An adapted method (ASTMD 1739:1970) was used to determine the presence of asbestos hazard in a form of mineral count. This method was also used for the identification of asbestos and other minerals in different dust samples using the XRD technique. Physical features of all minerals such as the shape, size and type were also determined as part of the characterization process using the SEM-EDS technique. The ASTMD1739:1998 method gave rise to higher retention of settleable dust, hence it was found to be more efficient. Unfortunately, this best performing method is not legislated or regulated by the government. This researcher concludes that the reasons could be due to the different shapes of the windshield designs (which means the different designs of windshields) at may make it difficult to standardize and control. However, this information gap provides an opportunity of a longer focused study of this method with the intention of finding a standardized windshield design that could be recommended for use in the country. Secondly, the units that had both water and algaecide gave rise to higher settleable Mpumalanga. Three exceedances of 600 mg/m2/day of residential limit regulated through National Dust Control Regulation no.28 of 2013 presented in decreasing order in Limpopo were 2724 mg/m2/day at Site E, 1638 mg/m2/day at Site D and 834 mg/m2/day at Site B in the same month of March 2017 . The XRF data of metal oxides, including these top three [Si(IV)O2, Fe2(III)O3 and Al2(III)O3], confirm the dominance of silicate minerals in surface dust samples from both provinces. The XRD mineralogy data from filtered settleable dust show the dominance of the amphibole asbestos particulates ranging from 18 to 56 % in Limpopo province and 2.0 to 3.0 % in Mpumalanga province. Low presence of serpentine minerals with the highest being 2.0 % and 7.0 % in Limpopo and Mpumalanga provinces respectively. About 8.0 to 43 % of amphibole asbestos minerals were measured on trapped dust in Limpopo together with zero detection of serpentine. No asbestos minerals were detected on trapped dust from Mpumalanga, despite the close proximity of the unrehabilitated asbestos mine dumps All airborne asbestos fibres that were captured on the filter substrates were a bove the limit value of 100 f/mL of air. The highest airborne asbestos fibre and concentration counts m easured were 40 fibres and 0, 00434 f /mL concentration in October 2017 at Site A. The second highest fibre count concentration was measured in June with 0,00287 f/mL at Site A in September 2017 and 0,01085 f/mL at the Site D in June 2017 monitoring sites. Again, the highest in June 2017 with 0,00125 f/mL for Site A for Limpopo Province. In Mpumalang a the lowest asbestos fibre concentration which are be low the OHSA no. 39 of 1993 and MDHS 39/ 4, 1995 0.1 f/mL and 100 f/mL However, from the safety perspective all asbestos fibres or minerals inhaled are a hazard to human health. The study established that the adapted asbestos mineral count method succeeded in identifying and quantifying the asbestos minerals that existed in the settleable dust samples from the study areas. These outcome s were successfully validated with the test undertaken using both the officially (Air Con 2 sampler) and unofficial (E sampler) recognized method of asbestos fibre count. The adapted mineral count method provides the research community with an alternative, cost effective and user friendly method of analysis. Also, the validation method s gave additional new information. Of a total of 120 of ex- posed filter papers used in the official asbestos fibre Air Con 2 sampler, 28 filters had positive presence of asbestos fibres, making it 23 collection efficiency And of the 100 exposed filt er papers used in for E samplers, only 8% collection efficiency was recorded. The results means that the official asbestos fibre Air Con 2 sampler has 23 more collection efficiency than the general particulate matter E sampler for air- borne asbestos monitoring. The impact of these results could also be that a general particulate matter high volume sampler c ould still be used for asbestos fibre monitoring in the absence of a specific and selective Air Con 2 sampler, as long as the user appreciates abo ut 23 collection deficiency. These findings go a long way in helping to make air quality research domain accessible. Since the ASTM D1739:1998 method has been found to perform better than the officially recognized method, this study recommends that the regulators of air quality in the country consider it. But, the method will first require some improvement and standardization particularly the different wind shield designs before it could be officially accepted as the method of collection and analyses for settleable dust. It is hoped that the air quality research community will take up the challenge.
Grond en ander geologiese materiale wat op die aardkors aangetref word, is bekend dat hulle ryk is in silikaatminerale wat natuurlik voorkom. Asbes is een van die veselagtige silikaatminerale wat hoofsaaklik in sommige streke van die Limpopo, Mpumalanga en Noord-Kaap Provinsies in Suid-Afrika ontgin is. Ondanks die staking van asbesmynbou in 2002 as gevolg van gepaardgaande gesondheidseffekte op mense, is daar steeds kommer oor moontlike blootstelling aan asbesvesels in die omgewing. 'n Enkele asbesvesel bestaan uit miljoene mikroskopiese naaldagtige vesels wat maklik breek om partikels van inasembare grootte te produseer wat volgens berigte longsiektes veroorsaak. Die belangrikste bron van asbesvesels in voormalige myngebiede is asbesmynhope en besmette asbesoppervlakgrond. Asbesmynhope in Limpopo Provinsie word gedeeltelik gerehabiliteer, terwyl hulle in Mpumalanga Provinsie nie gerehabiliteer word nie, en al hierdie mynhope is nou onder die regering se toesig omdat die oorspronklike eienaars die mynhope verlaat het. Die neerslagbare stof is die eerste aanduiding van stofbesoedeling in die lug en is gebruik om die terreine wat gemoniteermoet word, te kies. 'n Loodsstudie is uitgevoer om die prestasie van die ASTMD1739:1998 en ASTMD1739:1970 metodes te toets. In die loop van die studie is 'n amptelike ASTMD1739:1970 metode gebruik en toegepas vir die versameling van neerslagbare stofmonsters. In Mpumalanga en Limpopo Provinsies respektiewelik is daar altesaam tien (10) terreine gekies rondom kwesbare menslike nedersettings wat naby die verlate asbesmynhope geleë is. Stofmonsters in die lug, oppervlak en wat vasgevang is, is een keer per maand versamel vanaf April 2016 tot Junie 2017 rondom menslike nedersettings in die nabyheid van die verlate asbesmynhope. Stofmonsters in die lug is versamel volgens die amptelike neerslagbare stofmoniteringsmetode, die E monsternemer en die Air-Con 2 monsternemer. Oppervlakstof is buite met behulp van 'n kwas en stofpan rondom die neerslagbare stofopvangeenhede opgevang en is in gemerkte ritsakke van plastiekmateriaal geberg. Stofmonsters wat vasgevang is, is met behulp van kleeflint, binne en buite, om vensterruite, op meubeloppervlaktes en op voorruitte van ou motors versamel, en is in gemerkte geslote houers geberg. Oppervlakgrondmonsters is ook voor versameling met die draagbare asbesanaliseerder gefilter. Die monsters is breedvoerig en sorgvuldig voorberei en hanteer om kruisbesmetting tot ‘n minimum te beperk deur gebruik te maak van standard laboratoriummetodes en is ontleed met behulp van gekalibreerde analitiese instrumente. 'n Aangepaste metode is gebruik om die teenwoordigheid van asbesgevaar in 'n vorm van mineraaltelling te bepaal. Hierdie metode is ook gebruik vir die identifisering van asbes en ander minerale in verskillende stofmonsters met behulp van die XRD tegniek. Die fisiese kenmerke van alle minerale soos die vorm, grootte en tipe is ook bepaal as deel van die karakteriseringsproses met behulp van die SEM-EDS tegniek. Die ASTMD1739:1998 metode het gelei tot 'n hoër retensie van neerslagbare stof, en daarom is gevind dat dit doeltreffender is. Ongelukkig word hierdie metode wat die beste presteer nie deur die regering gewettig of gereguleer nie. Hierdie navorser kom tot die gevolgtrekking dat die redes kan wees as gevolg van die verskillende vorms van die voorruitontwerpe wat dit moeilik kan maak om dit te standaardiseer en te beheer. Hierdie inligtingsgaping bied egter 'n geleentheid tot 'n langer gefokusde studie van hierdie metode met die doel om 'n gestandaardiseerde voorruitontwerp te vind wat aanbeveel kan word vir gebruik in die land. Tweedens het die eenhede wat beide water en alge-suurwater gehad het, gelei tot 'n hoër neerslagbare stof in Mpumalanga Provinsie. Drie oorskrydings wat in dalende volgorde in Limpopo aangebied is, was 2724 mg/m2/dag op perseel E, 1638 mg/m2/dag op perseel D en 834 mg/m2/dag op perseel B in dieselfde maand van Maart 2017. Die XRF data van metaaloksiede, met inbegrip van hierdie top drie [Si(IV)O2, Fe2(III)O3 en Al2(III)O3], bevestig die oorheersing van silikaatminerale in oppervlakstofmonsters van beide provinsies. Die XRD mineralogiedata van gefiltreerde, neerslagbare stof toon die oorheersing van die amfibool asbesdeeltjies wat wissel tussen 18 en 56 % in Limpopo Provinsie en 2.0 en 3.0 % in Mpumalanga Provinsie. Daar is ‘n lae teenwoordigheid van serpentynminerale met die hoogste onderskeidelik 2.0 % en 7.0 % in die Limpopo en Mpumalanga Provinsies onderskeidelik. Ongeveer 8.0 tot 43 % van die amfibool asbesminerale is op vasgevangde stof in Limpopo gemeet, tesame met geen opsporing van serpentyn. Geen asbesminerale is opgespoor in die vasgevangde stof van Mpumalanga nie, ondanks die nabyheid van die ongerehabiliteerde asbesmynhope. Alle asbesvesels in die lug wat op die filtersubstrate vasgelê is, was bo die grenswaarde van 100 f/mL lug. Die hoogste asbesvesel en konsentrasietellings in die lug gemeet, was 40 vesels en 'n konsentrasie van 2.083 f/mL in Oktober op Terrein A. Die volgende hoogste veseltellingkonsentrasie is in Junie gemeet met 6.590 f/mL op die Terrein A en 5.272 f/mL op die Terrein D moniteringsterreine. In Mpumalanga was die hoogste asbesveselkonsentrasie 2.190 f/mL in Junie en 2.083 f/mL in November op Terrein D. Uit ‘n veiligheidsperspektief is alle asbesvesels of minerale wat ingeasem word egter 'n gevaar vir die mens se gesondheid. Die studie het vasgestel dat die aangepaste asbesmineraaltellingmetode daarin geslaag het om die asbesminerale wat in die neerslagbare stofmonsters uit die studiegebiede bestaan te identifiseer en te kwantifiseer. Hierdie uitkoms is suksesvol bekragtig met die toets wat onderneem is met behulp van die amptelik erkende metode vir die telling van asbesvesel. Die aangepaste mineraaltellingmetode bied aan die navorsingsgemeenskap 'n alternatiewe, koste-effektiewe en gebruikersvriendelike ontledingsmetode. Aangesien daar gevind is dat die ASTMD1739:1998 metode beter presteer as die amptelik erkende metode, beveel hierdie studie aan dat die reguleerders van luggehalte in die land dit oorweeg. Maar die metode sal eers verbetering en standaardisering verg, veral die verskillende windskermontwerpe voordat dit amptelik aanvaar kan word as die metode om neerslagbare stof te versamel en te ontleed. Daar word gehoop dat die gemeenskap wat luggehalte navors die uitdaging sal aanpak.
Mabu le dišomišwa tše dingwe tša bothutaswika tše di hwetšagalago bokagodimo ba Lefase di tsebja di e na le diminerale tše dintši tša tlhago tše di diragalago ka tlhago. Marela ke e ngwe ya diminerale tše di nago le dimela tše di ntši kudu tše di bego di epšwa kudu mafelong a mangwe a diphrofentshe "diphrofentsheng tša Limpopo, Mpumalanga le North Cape Afrika Borwa. Le ge go feditšwe go epšwa marela ka lebaka la ditlamorago tše amanago le maphelo a batho ka 2002, go na le pelaelo malebana le go utullwa ga malwetši a marela. Fibre ke ye ngwe ya marela ye e dirilwego ka maekrosekopiki tše dimilione tše di ka senyegago bonolo go tšweletša khemobonolo yeo e hlamago malwetši a mafahla. Sehlodikgolo sa malwetši a marela mafelong a mathomo ao go bego go le meepo ke sekoti sa marela le mabu a ka godimo ga marela. Dikoti tša meepo ya Marela Phrofentsheng ya Limpopo di mpšhafaditšwe ka tsela ye itšego, eupša Phrofentsheng ya Mpumalanga ga se tša mpšhafatšwa gomme mafelo a ka moka a laolwa ke mmušo gobane beng ba tšona ba di tlogetše. Lerole le ka rarollwago ke sešupopele sa tšhilafalo ya moya e dirwago ka moya gomme se be se šomišwa go kgetha mafelo ao a loketšwego go hlokomelwa. Go ile gwa dirwa tekolo ya go leka tšhomo ya mekgwa ya ASTMD1739: 1998 le ASTM D 1739: 1970. Ge re ntše re tšwela pele ka thuto, go šomišitšwe mokgwa wa semmušo wa ASTM D1739: 1970 gomme wa šomišwa lebakeng la go kgoboketša sampole ya lerole e ka rarollwago. Mafelo a lesome (10) a hweditšwe kgauswi le bodulo ba batho bjo bo lego kotsing ka dikoti tša meepo ya marela di ile tša kgethwa diphrofentsheng tša Mpumalanga le Limpopo ka go latelana. Disampole tša moya tša ka godimo ga lefase, godimo le tše di khutilego di ile tša kgoboketšwa ga tee kgweding kgauswi le bodulo ba batho tše di bego kgauswi kudu le dikoti tša meepo ya marela go tloga ka la 2016 Mopitlo go fihla ka Phupu 2017. Mehuta ya lerole ye sepetšwago ke moya e ile ya kgoboketšwa go šomišwa mokgwa wa semolao wa go tšweletša lerole, E-sampler le sampole ya Air-Con 2. Lerole la ka godimo le be le kgoboketšwa ka ntle go rarela dikarolo tša go kgoboketša lerole go šomišwa poratšhe le pane ya kota gomme le bolokelwa ka mekotleng e nago le zipper ye dirilwego ka polasetiki. Sampole ya lerole le le bego le gaeletšwe le ile la kgoboketšwa ka theipi ya go momela bokagareng le bokantle bja morumofasetere,mabotong a phahlo , le godimo ga galasebokapele dikoloing tša kgale gomme tša bolokwa ka gare ga didirišwa tšeo di makilwego. Disampolo tša mabu a ka godimo di be di hlahlobjwa gape ka mokgwa wa go kgwa ka letsogo ke mohlahlobi wa marela pele go kgoboketšwa. Disampole di be di lokišitšwe kudu ebile di dirilwe ka tlhoko go efoga tšhilafalo ka mekgwa ye tlwaelegilwego ya laporatori gomme ba e hlahloba ba šomiša didirišwa tša go hlahloba. Mokgwa o ikgethilego o šomišwa go hwetša bogona ba kotsi ya marela ka mokgwa wa palo ya diminerale. Mokgwa wo o be o šomišitšwe gape le go bošupong ba marela le diminerale tše dingwe ka gare ga disampole tše di fapanego tša lerole go šomišwa mokgwa wa XRD. Dibepegopono tša diminerale ka moka go swana le sebopego, bogolo le mohuta le tšona di be di tšewa e le karolo ya tshepetšo ya pharodipataka go bogolo le mohuta le tšona di be di tšewa e le karolo ya tshepetšo ya pharodipataka go šomišwa mokgwa wa SEM-EDS. Mokgwa wa ASTMD1739: 1998 o ile wa dira gore go bolokwe lerole le phagameng ka go fetolegago, ka gona go hweditšwe gore le šoma gabotse kudu. Ka bomadimabe, mokgwa wo o tšweletši kudu ge o ngwadišwa ke molao go mmušo. Monyakišiši wo o phetha ka gore mabaka e ka ba ka lebaka la dibopego tše di fapaneng tša meralo ya setsi sa moya se se ka dirago gore go be boima go tseba le go laola. Le ge go le bjalo, sekgoba se sa tshedimošo se fa monyetla wa go ithuta nepišo e telele ya maikemišetšo a go hwetša moralo o tiišitšwego wa moya o ka šišinywago gore o šomišwe ka nageng. Ya bobedi, diyuniti tše di bego di e na le meetsi le algaecide di ile tša tšweletša maemo a phagamego Mpumalanga Phrofentsheng. Ditekanyetšo tše tharo tše di tšweleditše ka tatelano ya taolo e fokotšegago e be e le 2724 mg/ m2/ letšatši go Site E, 1638 mg / m2/ letšatši go Site D le 834 mg/ m2/ letšatši go Site B kgweding ye tee ya Hlakola 2017 Dintlha tša XRF tša di-oxide tša tšhipi, go akaretša tše tše tharo tša godimo [Si (IV) O2, Fe2 (III) O3 le Al2 (III) O3], di tiiša boleng bo phagameng ba diminerale tša silrate mehuteng ya lerole ye e tšwago diphrofentsheng ka bobedi. Dintlha tša XRD tša mineralogy tše di tšwago leroleng le tšhilafatšong di ka tšewa di bontšha phelo ya marela ya amphibole go tloga go 18 go iša go 56% phrofentsheng ya Limpopo le 2.0 go iša go 3.0% phrofentsheng ya Mpumalanga. Bogonatlase ba diminerale tša serpentine tše phagameng ka go fetišiša e le 2.0% le 7.0% diphrofentsheng tša Limpopo le Mpumalanga ka go latelana. Go lekana 8.0 go iša go 43% ya diminerale tša marela tše lekantšwego di ile tša lekanywa leroleng le ageeletšwego ka Limpopo gammogo le go utullwa ga serpentine. Ga go na diminerale tša marela tše di hweditšwego leroleng le ageeletšwego le tšwago Mpumalanga, le ge e le kgauswi kgauswi le dikoti tša mope wa maraba wa marela se a mpšhafatšwago. Mehuta ka moka ya moya ya marela ye e bego e swerwe ka gare ga moya o bego o Mehuta ka moka ya moya ya marela ye e bego e swerwe ka gare ga moya o bego o le ka godimo wa boleng ba moya wa 100 f /mL. Mohuta o phagamego go fetišiša wa moya wa marela le dipalo tša mahlorišo a lekantšwego e be e le tše 40 le bogolo ba 2.083 f /mL ka Diphalane go Site A. Tekanyomahloriš e latelago ya fiber e lekantšwe Phupu ka 6.590 f /mL go Site A le 5.272 f /mL Site D mafelong a tlhahlobo. Nageng ya Mpumalanga, di-fibre tša marela tše phagamego ka go fetišiša e be e le 2.190 f / mL ka Phupu le 2.083 f /mL ka Dibatsela go Site D. Le ge go le bjalo, go latela ponego ya tšhireletšo, fibre ka moka tša marela goba diminerale tše di hengwago di kotsi maphelong a botho. Boithuto bo bo utullotše gore mokgwa wo lekantšwego wa marela o bontšhitšwegošupo o atlegile go kgetholla le go hlakola diminerale tša marela tše di bego di le gona ka gare ga disampolo tša lerole le tšwago mafelong a boithuto. Sephetho se se netefaditšwe katlego le tlhahlobo ye e dirilwego e šomišwago mokgwa wo amogetšwego ke molao wa marela fiber. Mokgwa o lekantšwego wa diminerale o thuša setšhaba sa dinyakišišo ka mokgwa o mongwe wa tlhahlobo ye e šongwago, gabotse e bile ye botho. Go tloga go mokgwa wa ASTM D1739: 1998 o hweditšwe o šoma gabotse go feta mokgwa wo amogetšwego ke molao, thuto ye e šupetša gore balaodi ba boleng ba moya nageng ba e nagane. Empa, mokgwa wo o tla hloka mpšhafatšo le maemo pele kudu meralo ye fapaneng ya thebe ya moya pele e ka amogelwa ke molao e le mokgwa wa go kgoboketša le go sekaseka lerole le le ka rarolwago. Re tshepa gore setšhaba sa dinyakišišo tša boleng ba moya se tla tšea bothata bo.
Mobu le lisebelisoa tse ling tsa jioloji tse fumanehang bokaholimo ba Lefatše li tsejoa li na le liminerale tse ngata tsa tlhaho tse etsahalang ka tlhaho. Asbestos ke e 'ngoe ea liminerale tse nang le silika e ngata e neng e chekoa haholo libakeng tse ling tsa liprofinse tsa "liprofinse tsa Limpopo, Mpumalanga le North Cape Afrika Boroa. Leha ho felisoa morafo oa asbestos ka lebaka la litlamorao tse amanang le bophelo bo botle ba batho ka 2002, ho ntse ho na le ts'oenyeho mabapi le ho pepesetsoa ha tikoloho likhoele tsa asbestos. Fiber e le 'ngoe ea asbestos e entsoe ka likhoele tse limilione tse kang nale tse tsoang habonolo ho hlahisa likaroloana tse sa bonoeng tse tlalehang libaka-mafuamatšo. Mohloli o ka sehloohong oa likhoele tsa asbestos libakeng tseo pele e neng e le tsa meepo ke lithako tsa asbestos le mobu o silafetseng oa asbestos. Likotlo tsa merafo ea Asbestos Profinseng ea Limpopo li nchafalitsoe ka tsela e itseng, athe Profinseng ea Mpumalanga ha e nchafatsoe 'me libaka tsena kaofela li laoloa ke mmuso hobane beng ba tsona ba ba lahlile. Lerōle le ka rarolloang ke letšoao la pele la tšilafalo ea moea e tsoang ka moea mme le ne le sebelisetsoa ho khetha libaka tseo li lokelang ho-shebelloa. Ho ile ha etsoa boithuto ba ho leka ts'ebetso ea mekhoa ea ASTMD1739: 1998 le ASTM D 1739: 1970. Ha re ntse re tsoela pele ka thuto, ho sebelisitsoe mokhoa oa semmuso oa ASTM D1739: 1970 'me oa sebelisoa bakeng sa ho bokella sampole ea lerōle e ka rarolloang. Sebaka sa libaka tse leshome (10) tse fumanehang haufi le bolulo ba batho ba tlokotsing tse haufi le libaka tse lahliloeng tsa meepo ea asbestos li ile tsa khethoa liprofinseng tsa Mpumalanga le Limpopo ka ho latellana. Lisampole tsa moea tse ka holim'a lefatše, holimo le tse patiloeng li ile tsa bokelloa hang ka khoeli ho potoloha libaka tsa bolulo tsa batho tse haufi haholo le libaka tse lahliloeng tsa moepo oa asbestos ho tloha ka Mmesa 2016 ho fihlela ka Phuptjane 2017. Mefuta ea lerōle e tsamaisoang ke moea e ile ea bokelloa ho sebelisoa mokhoa oa semolao oa ho hlahisa lerōle, E-sampler le sampole ea Air-Con 2. Lerōle le kaholimo le ne le bokelloa ka ntle ho potoloha likarolo tsa ho bokella lerōle le sebelisa brashi le pane ea patsi mme le bolokiloe ka mekotleng e nang le zipper e entsoeng ka thepa ea polasetiki. Mehlala ea lerōle e neng e tšoasehile e ile ea bokelloa ho sebelisoa theipi e khangoang ka tlung le kantle kahare ho lifensetere, ka holim'a thepa ea ka tlung le lifensetereng tsa likoloi tsa khale 'me li bolokiloe ka har'a lisebelisoa tse koetsoeng. Meetso ea mobu e kaholimo le eona e ile ea hlahlojoa ka letsoho le ts'oaroang ka asbestos pele ho pokello. Mehlala e ne e hlophisitsoe haholo ebile e entsoe ka hloko ho qoba ho silafatsa kapa ho fokotsa tšilafalo ea tšebeliso ea mekhoa e tloaelehileng ea laboratori mme e ile ea hlahlojoa ho sebelisoa lisebelisoa tsa tekanyetso. Mokhoa o ikhethileng o sebelisitsoe ho fumana ho ba teng ha kotsi ea asbestos ka mokhoa oa palo ea liminerale. Mokhoa ona o ne o boetse o sebelisoa bakeng sa ho khetholla asbestos le liminerale tse ling ka har'a disampole tse fapaneng tsa lerōle ho sebelisoa mokhoa oa XRD. Litšobotsi tsa 'mele tsa liminerale tsohle tse kang sebopeho, boholo le mofuta le tsona li ne li nkuoa e le karolo ea ts'ebetso ea sebopeho ho sebelisa mokhoa oa SEM-EDS. Mokhoa oa ASTMD1739: 1998 o ile oa etsa hore ho bolokoe lerōle le phahameng ka ho fetelletseng, ka hona ho fumanoe hore le sebetsa hantle haholo. Ka bomalimabe, mokhoa ona o atlehileng ka ho fetisisa ha o ngolisoe ke molao kapa 'muso. Mofuputsi enoa o phethela ka hore mabaka a ka ba teng ka lebaka la sebopeho se fapaneng sa meralo ea setsi sa moea se ka etsang hore ho be thata ho tseba le ho laola. Leha ho le joalo, lekhalo lena la tlhaiso-leseling le fana ka monyetla oa ho ithuta ho tsepameng molemong oa mokhoa ona ka sepheo sa ho fumana moralo o tiisitsoeng oa moea o ka khothalletsoang hore o sebelisoe ka har'a naha. Ya bobedi, diyuniti tse neng di na le metsi le algaecide li ile tsa hlahisa maemo a phahameng a ho tsetsahala Mpumalanga. Litekanyetso tse tharo tse fanoeng ka tatellano ea taolo e fokotsehang e ne e le 2724 mg/ m2/ letsatsi ho Site E, 1638 mg /m2/ letsatsi ho Site D le 834 mg / m2/letsatsi ho Site B ka khoeli e tšoanang ea Hlakubele 2017. Lintlha tsa XRF tsa li-oxide tsa tšepe, ho kenyelletsa tsena tse tharo tse holimo [Si (IV) O2, Fe2 (III) O3 le Al2 (III) O3], li tiisa boleng bo phahameng ba liminerale tsa silrate mefuteng ea lerōle e tsoang liprofinseng ka bobeli. Lintlha tsa XRD tsa mineralogy tse tsoang lerōleng le ts'ilafatsoang li ka nkuoa li bonts'a phello ea asbestos ea amphibole ho tloha ho 18 ho isa ho 56% profinseng ea Limpopo le 2.0 ho isa ho 3.0% profinseng ea Mpumalanga. Boteng bo tlase ba liminerale tsa linoha tse phahameng ka ho fetisisa e le 2.0% le 7.0% liprofinseng tsa Limpopo le Mpumalanga ka ho latellana. Hoo e ka lerōleng le ts'oaroang ho la Limpopo hammoho le ho sibolloa ha noha. Ha ho na liminerale tsa asbestos tse fumanoeng lerōleng le tsubelletsoeng le tsoang Mpumalanga, leha ho le haufi le marang-rang a litopo tsa asbestos tse sa ntlafatsoang. Mefuta eohle ea moea e kang asbestos e neng e hapiloe kahare ho moea o ne o le kaholimo ho boleng ba moea oa 100 f /mL. Mofuta o phahameng ka ho fetisisa oa moea oa asbestos le lipalo tsa mahloriso tse lekantsoeng e ne e le likhoele tse 40 le boholo ba 2.083 f /mL ka Mphalane ho Site A. Khakanyo e latelang ea fiber fiber e latelang e lekantsoe ka Pherekhong ka 6.590 f /mL ho Site A le 5.272 f /mL setsing D libaka tsa tlhahlobo. Naheng ea Mpumalanga, li-fiber tsa asbestos tse phahameng ka ho fetisisa e ne e le 2.190 f /mL ka Phuptjane le 2.083 f /mL ka Pulungoana ho Site D. Leha ho le joalo, ho latela pono ea ts'ireletso, likhoele tsohle tsa asbestos kapa liminerale tse kentsoeng li kotsi bophelong ba motho. Boithuto bo fumane hore mokhoa o lekantsoeng oa "asbestos" o ntlafalitsoeng o atlehile ho tseba le ho hlakisa liminerale tsa asbestos tse neng li le teng ka har'a mehlala ea lerōle e tsoang libakeng tsa boithuto. Sephetho sena se netefalitsoe ka katleho le tlhahlobo e entsoeng e sebelisang mokhoa o amohetsoeng ka molao oa asbestos fiber count. Mokhoa o lekantsoeng oa liminerale o thusa sechaba sa lipatlisiso ka mokhoa o mong oa tlhahlobo o sebetsang, o sebetsang hantle ebile o sebelisang botsoalle. Ho tloha ha mokhoa oa ASTM D1739: 1998 o fumanoe o sebetsa hantle ho feta mokhoa o amohetsoeng ka molao, thuto ena e khothaletsa hore batsamaisi ba boleng ba moea naheng ba e nahane. Empa, mokhoa ona o tla hloka ntlafatso le maemo pele haholo mealo e fapaneng ea thebe ea moea pele e ka amoheloa ka molao e le mokhoa oa ho bokella le ho sekaseka lerōle le ka rarolloang. Re tšepa hore sechaba sa lipatlisiso tsa boleng ba moea se tla nka bothata bona.
Environmental Science
Ph. D. (Environmental Sciences)