Dissertations / Theses on the topic 'Deposits and depositors'

Banks play a pivotal role in economic growth and development of all countries and therefore the stability of the banking system is a vital goal of bank supervisors. Banks act as delegated monitors of depositors’ funds and this relationship, like all principal-agent relationships, presents agency problems. In the case of banks agency problems arise because depositors cannot accurately assess the financial health of banks due to the asymmetry of information existing between banks and depositors. Because banks possess private information on their borrowers, which depositors cannot access, it exposes depositors to risk of loss of deposits in cases of bank failures originating from nonrepayment of such loans. This asymmetry of information also exposes banks to runs by depositors and these runs can lead to bank failures with devastating effects for the financial system and the economy at large. It is for this reason that banks are regulated and supervised more than other institutions. Bank failures are a worldwide phenomenon and South Africa is no exception as evidenced by historical and recent bank failures in South Africa. This thesis investigates the desirability of introducing an explicit deposit insurance scheme in South Africa as a means of protecting small, unsophisticated depositors who are almost always the losers when banks fail, and promoting financial stability. The study finds that bank failures in South Africa are mainly attributable to mismanagement of banks, liquidity problems and fraud. Bank failures as a result of the aforementioned reasons have led to depositors losing their deposits in South Africa. The absence of a clearly defined depositor protection scheme in South Africa, the inadequacy of the hitherto implicit guarantee system to protect depositors, and the poor record of the South African Reserve Bank in bank failure resolution, form the basis of the conclusion of the study, i.e., there is a case for the introduction of deposit insurance in South Africa. In order to assist South African policymakers in designing an effective deposit insurance scheme for the country, the thesis further provides a guide on how the most important design features of deposit insurance should be handled. This is in an attempt to ensure that the moral hazard problem inherent in deposit insurance is overcome.

The modeling of non-maturity deposits is a topic that is highlyimportant to many banks because of the large amount of funding that comes fromthese products. It is also a topic that currently is in the focus oflegislators. Although a non-maturity deposit may seem to be a trivial product,it has several characteristics that make it rather complex. One of the twopurposes of this thesis is to compare different models for the deposit rate ofnon-maturity deposits and to investigate the strengths and weaknesses of themodels. The other purpose is to find a new model for the deposit rate ofnon-maturity deposits. Several different models that are suggested in the literatureare described and evaluated based on the four aspects; goodness of fit,stability, negative interest rate environment and simplicity. Three new modelsfor the deposit rate are suggested in this thesis, one of which shows a verygood performance compared to the models that can be found in the literature.
Modellering av icke tidsbunden inlåning är ett ämne som är mycket viktigt för många banker på grund av den stora andel finansiering som kommer från dessa produkter. Det är också ett ämne som för närvarande väcker lagstiftares intresse. Även om icke tidsbunden inlåning kan tyckas vara en trivial produkt, har den flera egenskaper som gör den komplex. Ett av de två syftena med detta arbete är att jämföra olika modeller för kundräntan i icke tidsbunden inlåning och att undersöka modellernas styrkor och svagheter. Det andra syftet är att introducera en ny modell för kundräntan i icke tidsbunden inlåning. Flera olika modeller från litteraturen beskrivs och utvärderas baserat på de fyra utgångspunkterna passform, stabilitet, negativ räntemiljö och enkelhet. Tre nya modeller av kundräntor för icke tidsbunden inlåning föreslås i detta arbete, varav en visar ett mycket bra resultat jämfört med de modeller som föreslås i litteraturen.

Orientador : Bernardino Ribeiro de Figueiredo
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociencias
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Doutorado

Exploration companies commonly rely on geochemistry to identify alteration of distinctive geochemical and mineralogical character, surrounding metal sulphide deposits that were precipitated from hydrothermal fluids. However, examination of raw analytical data is prone to error due to closure effects and the difficulty in removing the effects of background variation in unaltered rocks from the variations imposed by later hydrothermal alteration. Closure can be avoided by using ratios, or by utilising mass balance approaches based on fixing volume, mass or concentration changes between samples of parent and daughter lithologies. Using a parent-daughter approach is limiting, because only pairs of samples can be compared at any one time and because an unaltered equivalent must be produced for each sample examined in this way. Pearce Element Ratio analysis and General Element Ratio analysis (PER and GER) are not restricted in this fashion, and are more amenable to interrogation of large data sets. PER and GER are also capable of decoupling background variation from that variation due to hydrothermal alteration. Furthermore, these ratio methods are readily applied to commercially derived lithogeochemical assays. In this study, various analytical methods and interpretive techniques (including PER and GER) have been applied to identify alteration in rocks around the Century and Elura Zn-Pb-Ag deposits, and to assess whether primary ore-related alteration effects can still be identified once altered rocks have been subjected to weathering. Ratios of trace elements over a conserved element have been used to generate a suite of pathfinder elements for each deposit. Elements enriched in host rocks around both deposits include the economic metals Zn, Pb and Ag, along with Rb and Tl. Sodium is ubiquitously depleted in altered rocks. Other elements in the pathfinder suites are distinctive to each deposit type, and include a number of major and trace elements that are added or removed from the rocks around the mineralised zones. For example, Sb and As are enriched in rocks around Elura mineralisation while Ge and Cd are enriched in samples around Century deposit. Iron carbonate development accompanied by potassic alteration, the destruction of albite and the absence of chlorite are the dominant mineral alteration effects at both deposits. PER and GER diagrams have been used to quantify the intensity of this alteration and allow lithogeochemistry to be used to vector towards high intensity alteration, which is adjacent to Century and Elura mineralisation. These ratio methods are applied to both visibly and cryptically altered rocks at both deposits, and have a very high degree of success in classifying alteration in unweathered rocks. The following simple PER ratios indicate proximity to Elura mineralisation: Ca/C, K/Al for shales, K/(Al-Na) for siltstones/sandstones. The following simple PER ratios indicate proximity to Century mineralisation: Mn/Ti, Mg/Ti and Fe/Ti vs C/Ti, K/Ti vs Al/Ti, K/Ti vs (Al-Na)/Ti. Pathfinder elements can be overlain onto PER and GER diagrams to aid in ranking the prospectivity of samples, and to assess mineral hosts for individual pathfinder elements. Weathering destroys most indicators of alteration in the Elura area, while alteration signatures are better preserved in host rocks around the Century deposit.

Orientador: José Ricardo Pelaquim Mendes
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências
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Resumo: Neste trabalho discute-se os desafios associados à atividade de perfuração de poços de petróleo através de formações afetadas pela presença de domos salinos. Domos salinos podem induzir grandes tensões nas formações subjacentes e adjacentes, impondo a necessidade de um planejamento específico para a perfuração e manutenção de poços de petróleo. Durante a perfuração, em frente à zonda de sal, há relatos de problemas de aprisionamento de coluna, dissolução de sal no fluido de perfuração, ocasionando a formação de batentes mecânicos e cavernas. Há ainda, nas formações que rodeiam um domo salino, devido à alterações no campo de tensões, problemas de instabilidade nas paredes do poço aberto e formação de zonas anormalmente prossurizadas. Após o revestimento do poço, há casos de colapso do revestimento. Para prever e mitigar os riscos associados à essa atividade é de fundamental importância o entendimento dos fenômenos físicos que o ocasionam. Com essa finalidade, foi feito um estudo à respeito de tais mecanismo físicos como fluência e instabilidade hidrodinâmica, mais especificamente a instabilidade de Rayleigh-Taylor. Desenvolveu-se, a partir de tal estudo, um modelo analítico para prever o desenvolvimento de um domo salino e discutiu-se a forma como este pode interferir em parâmetros importantes para a atividade de perfuração como, por exemplo, o campo de tensões nas formações adjacentes às camadas de sal
Abstract: In this present work are discussed the challenges associated with the drilling activities in oil wells through formations affected by the presence of salt domes. This geological structures can induce large stresses in the underlaying and adjacent formations, imposing the necessity of specific planning for drilling and maintenance of such oil wells. During drilling, facing the salt, there are reports of problems of stuck pipe, salt dissolution, forming mechanical stops and caves. There are still, in formations around a salt dome, due changes in the stress field, problems of well instability and abnormally pressure zones. After casing, there are cases of case collapse. To prevent and mitigate risks associated to this activity, is crucial understand the physical phenomena behind it. With such finality, was made an study related with such physical mechanisms, such hydrodynamic instability, specifically the Rayleigh-Taylor instability. Was developed, from this study, an analytical model to predict the salt dome development and was discussed the way such it can interfer in important paramenters related to the drilling activity as, for exemple, the tension field in the formation around the salt dome
Mestrado
Explotação
Mestre em Ciências e Engenharia de Petróleo

A cossimulação de teores em depósitos multivariados complexos com mais de três variáveis envolvidas, quando realizada por métodos clássicos, é extremamente trabalhosa e acaba por gerar resultados que precisam de ajuste posterior, principalmente com relação ao fechamento da soma dos teores nos blocos ou faixas granulométricas de interesse. A necessidade de ajustes posteriores, aliada à falta de praticidade destes métodos, motiva a busca por soluções alternativas que gerem resultados tão ou mais precisos e, sejam mais facilmente implementáveis no dia a dia da indústria mineira. Nesta tese foi analisada a viabilidade de aplicação de cinco combinações de métodos como alternativa aos métodos clássicos: a simulação individual pelo método de bandas rotativas de cada uma das variáveis, em suporte de pontos posteriormente reblocados (combinação 1); a simulação das transformações ilrs, também pelo métodos de bandas rotativas, de forma individual e em suporte de pontos posteriormente reblocados (combinação 2); a simulação diretamente em suporte de blocos dos fatores MAFs (combinação 3); a simulação diretamente em suporte de blocos dos fatores MAFs das ilrs, com a utilização da variável artificial Resto, também utilizada nas combinações 1,2 e 3 (combinação 4) e; a simulação diretamente em suporte de blocos dos fatores MAFs das ilrs, com a operação de fechamento (combinação 5). Para aplicação da metodologia proposta foram simulados os teores das variáveis Alap, Fe, Si e Ti, retidas na faixa 14#, para um depósito de bauxita do norte do Brasil. Os resultados obtidos em todas as combinações foram analisados com relação ao grau de reprodução das características estatísticas e de continuidade espacial, reprodução das somas dos teores dos dados originais também na faixa simulada e a reprodução das correlações, ou reprodução da ausência de correlações, também nos cenários simulados. Após a análise dos resultados obtidos, se pode concluir que todas as combinações testadas são passíveis de utilização, no entanto, somente as combinações quatro e cinco proveem uma solução acabada para o problema em questão. Isto se deve ao fato de estas duas combinaões de métodos serem as únicas que combinaram: a decomposição MAF, para descorrelacionar as variáveis, simular cada uma de modo independente das demais e mesmo assim garantir a reprodução das correações no final do processo; a transformação ilr, que, por considerar as amostras como composições pertencentes ao espaço de soma restrita e constante, Simplex, garante que a soma dos teores esteja garantida nos resultados das simulações; e, a simulação diretamente em suporte de blocos, que foi incluída por evitar que um grande número de pontos precise ser simulado e posteriormente ajustado para o suporte de blocos, dando agilidade ao processo. A combinação cinco se mostrou ainda mais vantajosa por não fazer uso da variável artificial Resto, o que diminui o número de variáveis a serem efetivamente simuladas. Apesar das vantagens apontadas, é inegável que o usuário precisa conhecer e estar atento à sequência em que as transformações devem ser aplicadas sobre os dados originais.
Cossimulation of complex multivariate deposits with more than three variables involved, when performed by classical methods, is extremely labor intensive and ultimately generate results that need further adjustment, especially with respect to the closing of the sum of the attributes of interest. The need for further adjustments, together with the difficulties in practical implementation of these methods, motivates the search for alternative solutions that generate results as or more accurate and which can be more easily implementable at the mining industry. This thesis analyzed the feasibility of five combinations of methods as an alternative to the classical ones: individual simulation by turning bands method, each variable at a time, in subsequent block support adjustment (combination 1); the simulation of ILRs transformations, also using the turning bands method, individually and followed by the block support correction (combination 2); the directly block simulation of MAFs factors (combination 3); direct block simulation of MAFs factors of ILRs with the use of artificial variable “Resto” also used in combinations 1,2 and 3 (combination 4) and direct block simulation of MAFs factors of ILRs with the closing operation (combination 5). To apply the proposed methodology, the following variables from a large bauxite deposit were chosen: mass retained at 14 # sieve, Alap, Fe, Si and Ti were simulated. The results obtained in all combinations were analyzed with respect to the level of reproduction of statistical characteristics and spatial continuity, reproduction of the sums of the grades of the original data also in the simulated scenarios, allied to variables cross-correlation reproduction in the simulated scenarios. The results lead to conclude that all tested combinations are amenable to use, however, only the 4 and 5 combinations provide a finished solution to the problem in question. The MAF decomposition was used to decorrelate the variables and so each one of those could be independently simulated, and the maintenance of correlations after the procces was assured, and the ilr transformation was included in both combinations 4 and 5 to provide results with constant sums of the grades in the sieve of interest. These two combinations guarantee the maintenance of the grades closed sum and correlations reproduction in simulated scenarios, and, still are computationally efficient as the block simulation was used to avoid the simulation of a large amount of points that need to be post processed. The last workflow proved to be even more advantageous for not using an artificial variable Resto, which reduces the number of variables to be effectively simulated. Despite of these advantages, it is undeniable that the user needs to know and to be aware of the sequence in which transformation should be applied to the original data.

В роботі розглядаються напрямки оптимізації депозитної стратегії банків України в умовах фінансової кризи.
Directions optimization strategy deposit banks in Ukraine in financial crisis considered in the article.

The subprime mortgage crisis (SMC) is an ongoing housing and nancial crisis that was triggered by a marked increase in mortgage delinquencies and foreclosures in the U.S. It has had major adverse consequences for banks and nancial markets around the globe since it became apparent in 2007. In our research, we examine an originator's (OR's) nonlinear stochastic optimal control problem related to choices regarding deposit inflow rates and marketable securities allocation. Here, the primary aim is to minimize liquidity risk, more speci cally, funding and credit crunch risk. In this regard, we consider two reference processes, namely, the deposit reference process and the residential mortgage loan (RML) reference process. This enables us to specify optimal deposit inflows as well as optimal marketable securities allocation by using actuarial cost methods to establish an ideal level of subprime RML extension. In our research, relationships are established in order to construct a stochastic continuous-time banking model to determine a solution for this optimal control problem which is driven by geometric Brownian motion. In this regard, the main issues to be addressed in this dissertation are discussed in Chapters 2 and 3. In Chapter 2, we investigate uncertain banking behavior. In this regard, we consider continuous-time stochastic models for OR's assets, liabilities, capital, balance sheet as well as its reference processes and give a description of their dynamics for each stochastic model as well as the dynamics of OR's stylized balance sheet. In this chapter, we consider RML and deposit reference processes which will serve as leading indicators in order to establish a desirable level of subprime RMLs to be extended at the end of the risk horizon. Chapter 3 states the main results that pertain to the role of stochastic optimal control in OR's risk management in Theorem 2.5.1 and Corollary 2.5.2. Prior to the stochastic control problem, we discuss an OR's risk factors, the stochastic dynamics of marketable securities as well as the RML nancing spread method regarding an OR. Optimal portfolio choices are made regarding deposit and marketable securities inflow rates given by Theorem 3.4.1 in order to obtain the ideal RML extension level. We construct the stochastic continuoustime model to determine a solution for this optimal control problem to obtain the optimal marketable securities allocation and deposit inflow rate to ensure OR's stability and security. According to this, a spread method of RML financing is imposed with an existence condition given by Lemma 3.3.2. A numerical example is given in Section 3.5 to illustrates the main issues raised in our research.
Thesis (M.Sc. (Applied Mathematics))--North-West University, Potchefstroom Campus, 2011.

Besshi-type deposits range in age from early Proterozoic to early Tertiary, of which the largest number are late Proterozoic, early Palaeozoic or Mesozoic in age. No Archaean examples of Besshi-type deposits are known, probably due to insufficient availability of sialic crust for erosion and clastic marine sedimentation before the start of the Proterozoic. All Besshi-type deposits are contained within sequences of clastic sedimentary rock and intercalated basalts in a marine environment. The basalts and amphibolites are principally tholeiitic in composition. Besshi-type deposits characteristically form stratiform 1enses and sheet-like accumulations of semi-massive to massive sulphide. The main ore assemblage consists dominantly of pyrite and/or pyrrhotite with variable amounts of chalcopyrite, sphalerite and trace galena, arsenopyrite, gold and e1ectrum, barite being absent in general. The median Besshi-type deposit (n=75) contains 1.3 million tonnes (Mt) of massive sulphide with a Cu grade running at 1.43%. It is suggested that Besshi-type deposits form by both exhalative and synsedimentary replacement processes when considering geological features and comparisons with modern analogues in the Guaymas Basin, Middle Valley and Escanaba Trough. The currently forming metalliferous sediments in the Red Sea provide for a brine pool model explaining the lack of footwall feeder zones below sheet-like deposits. Where thick sulphide lenses are contained in some Besshi-type deposits, combinations of exhalative precipitation and sub-sea-floor replacement of permeable sediments and/or volcanic rocks, take place in the upper parts of submarine hydrothermal systems.

Динамічний розвиток економіки України багато в чому залежить від ефективності роботи банківської системи, одним з основних джерел наповнення якої виступають депозити фізичних та юридичних осіб. Так, протягом останнього часу все більше уваги вітчизняних дослідників привертають питання організації ефективної системи яка б забезпечила налагоджений потік грошових коштів населення до банківської системи країни та змогла б забезпечити реальний сектор економіки необхідними інвестиційними ресурсами.
The dynamic development of Ukraine's economy largely depends on the efficiency of the banking system, one of the main sources of which are the deposits of individuals and legal entities. So, for the last time more and more attention of researchers attract domestic issues of efficient system which would ensure the streamlined flow of funds in the banking system of the country and would be able to provide the real economy the necessary investment resources.
Динамичное развитие экономики Украины во многом зависит от эффективности работы банковской системы, одним из основных источников наполнения которой выступают депозиты физических и юридических лиц. Так, в последнее время все больше внимания отечественных исследователей привлекают вопросы организации эффективной системы которая бы обеспечила налаженный поток денежных средств населения в банковскую систему страны и смогла бы обеспечить реальный сектор экономики необходимыми инвестиционными ресурсами.

Turbidite-hosted gold deposits contribute a significant proportion to world lode gold production and have also provided substantial gold to alluvial resources. Turbidity current deposits occur throughout geological time within Archaean greenstone belts, Proterozoic orogenic belts and rifted passive continental margins, and Palaeozoic geosynclines. Representing the end member of the sedimentary cycle, turbidites have the attribute of preservation not only on an individual bed basis but also due to below wave base accumulation in submarine deeps. Cyclic deposition according to the Bouma sequence punctuates turbidite deposition by a series of diastems. Accumulation of organic, pelagic and chemical sediments may concentrate gold to protore enrichment levels i n a primary sedimentary environment. Dewatering during diagenesis and low-grade metamorphism under reducing conditions may redistribute gold with transport as low energy organo- and thio-complexes. Gold may precipitate with diagenetic pyrite and silica near black shale and/or partially replace fine carbonate detritus. Gold solubility increases with high grade amphibolite facies metamorphism (T 400ºC) when efficient leaching of gold and transport by simple chloro- and hydroxychloro - complexes to lower greenschist regions takes place. Reduced permeability of turbidite strata induces hydrofracturing which focuses dewatering solutions. Gold is deposited due to pressure and temperature decrease or local changes in physico - chemico conditions caused by the reaction of fluids with wall rocks (reactive beds in turbidites are predominantly carbonaceous strata). The largest of turbidite - hosted goldfields are confined to back -arc or marginal sea basins with restricted oceanic circulation. The richest concentrations of gold occur proximal to the original source within the greenschist facies formations lowermost in a thick turbidite sequence and exhibit strong combined structural and lithological association. Turbidites represent important strata for the concentration and preservation of gold not only during sedimentation and diagenesis but also during later deformation and metamorphism.

This review summarises the factors which control the formation and distribution of surficial gold placer deposits. Regional tectonic and climatic conditions as well as gold source are considered. The characteristics of eluvial, alluvial, marine, glacial and fluvioglacial gold placer deposits are described. Particular attention is paid to the gold grains within these placers. These gold grains have a distinctive morphology and chemical composition which reflect the manner in which they were transported, deposited and concentrated within the placers. The knowledge of the processes which lead to the formation and location of surficial gold placers is then used to guide exploration and target potential deposits, which can then be evaluated.

The targets of the research were the gravel and sand deposits of different genetic type, as well as promising areas in the area of Lithuania. The present work defines the principle applied for construction of dynamical models of non-metal mineral deposits. The possibilities of automated analysis and evaluation of mineral deposit prospecting data have explored; the methodology for automation of mineral deposit use design solutions has created and introduced into a computer software; the possibilities of automation for calculation of production (mining) volumes according to the surveyor measurements have explored; the possibilities of automation for recording and controlling the production (mining) have explored in the dissertation. The modelling is done in 3D space enabling to see 3D perspective images of a pit from any point selected and prognosticate the course of excavation works.
Tyrimų objektais buvo pasirinkti įvairių genetinių tipų žvyro ir smėlio telkiniai bei prognoziniai plotai išsidėstę Lietuvos teritorijoje. Disertacijoje yra apibrėžtas nerūdinių naudingųjų iškasenų telkinių dinaminių modelių sudarymo principas; išnagrinėtos naudingųjų iškasenų telkinių žvalgybos duomenų automatizuotos analizės ir vertinimo galimybės; sukurta naudingųjų iškasenų telkinių naudojimo projektinių sprendinių automatizavimo metodika ir įdiegta į programinę įrangą; išnagrinėtos kasybos apimčių pagal markšeiderinius apmatavimus apskaičiavimo automatizavimo galimybės; išnagrinėtos kasybos proceso apskaitos ir kontrolės automatizavimo galimybės. Modeliavimas atliekamas trimatėje erdvėje, kas sudaro galimybę matyti trimačius perspektyvinius karjero vaizdus iš bet kokio pasirinkto taško ir numatyti naudingųjų iškasenų telkinių kasybos darbų eigą.

Islamic banking deposits are fundamentally structured in a different way than the conventional banking deposits. Each type of Islamic banking deposits, such as savings, demand, and timed deposits, is devised using the approved Shari’ah contracts such as qard, wadiah, murabahah, and mudarabah. These contracts are opposed to the conventional concepts, as they are based on the concept of a ‘lender-borrower’ relationship. In addition, the Shari’ah-approved contracts are unique as they feature a different nature of risk and return. This is especially the case for mudarabah contracts (henceforth referred to as profit-sharing contracts). The uniqueness of profit-sharing contracts in deposit products has been given due recognition in theory and also in practice, as most of the Islamic banks in Malaysia offered this product. In addition, the unique features and characteristics of profit-sharing based deposit accounts are also highlighted in the prudential standards issued by prominent regulatory bodies such as AAOIFI and IFSB which, have been adopted by the Bank Negara Malaysia (Central Bank of Malaysia). Nevertheless, it is argued by many Islamic banks practitioners, especially in Malaysia, that the concept of profit-sharing in deposits products is not practical in reality, because the depositors do not behave according to, nor accept the principles that have been laid down in the Shari’ah. Thus it is argued that both the depositors and the Islamic bankers have treated the product similar to any other conventional banking deposits products. The main aim of this study, hence, is to explore and examine the level of awareness, knowledge, perceptions, and attitude of the Islamic banking depositors in Malaysia towards characteristics of profit-sharing deposits accounts in accordance with the fundamental Shari’ah principles but also the regulations prevailing. In addition, this research also attempts to explore the significant determinant factors that encourage the depositors to engage with Islamic banking deposits accounts in general and profit-sharing deposits accounts in particular. In fulfilling the aim of the study, primary data collection research was adopted through a survey questionnaire technique. The questionnaires were distributed to eight Islamic banks representing various types of Islamic banks in Kuala Lumpur and Selangor. The questionnaire asked various pertinent questions, which intended to elicit the depositors’ opinions, perceptions, and attitudes towards the unique characteristics of profit-sharing contract as specified in Shari’ah muamalah principles. The characteristics among others are: (i) concept of uncertain deposits returns; (ii) concept of non-guarantee for the deposits; (iii) concept of profit equalization reserve. A total 649 of the returned questionnaires were complete and fit for analysis purpose. The data were analysed using various statistical analysis techniques ranging from simple frequency distribution analysis to the more advanced analyses such as non-parametric statistical analysis, factor analysis, and logistic regression. In general, the results of the study show that the level of awareness of the need to have Islamic banking deposits accounts because of religious reasons is considered as high among the Malaysian depositors. Nevertheless, the results also indicate that a high level of awareness is not being translated into a high level of understanding concerning the objectives of the products which are structured in accordance to the Shari’ah-compliant contracts. This can be seen in the major findings of this study: the characteristics of profit-sharing contracts, which arguably are the most desirable Shari’ah-compliant contracts, are not acceptable to the depositors. This indirectly implies that they are still strongly influenced by the nature of conventional banking products. In addition, the logistics regression results further proved that related factors (‘financial services’ and ‘income’) emerged as the main determinants in creating demand for profit-sharing deposits accounts. The results of the research should draw the attention of the Islamic bankers and also the regulators to finding ways for improving the level of understanding among the depositors. However, the critical successful factor in educating the depositors is highly dependent on the level of knowledge exhibited by the Islamic bankers themselves, which can be a real concern as highlighted by the findings of this study.

Northwestern Mexico is characterized by different metallogenic provinces that are included along the Basin and Range, the Sierra Madre Occidental, and the Baja California geological provinces. With the purpose of contribute to the current understanding of the mineralizing processes, the present study focused on two important copper metallogenic provinces: the Cananea Porphyry District in Sonora, and the Sediment-hosted Stratiform Copper- and Mn-deposits in Baja California Sur. The U-Pb zircon ages from the mineralizing porphyries from Cananea district suggest a continued magmatic activity period of ~6 Ma. Also suggests a period of ~20 Ma for the entire magmatic activity in the district. The Re-Os molybdenite ages demonstrate five well-constrained mineralization events in the district; the main mineralization is constrained over a short period of time (~4 Ma). The new molybdenite age from the Pilar deposit documents the oldest mineralizing pulse, suggesting possibly the initiation of the Laramide mineralization in northern Sonora. A detailed study of Mariquita porphyry Cu and Lucy Cu-Mo deposits in the Cananea district was performed. Four hydrothermal stages were defined in Mariquita, whereas a single hydrothermal pulse characterizes Lucy. Emplacement depths between 1-1.2 km, and temperatures between 430-380ºC characterized the mineralization from Mariquita, whereas deeper emplacement depths and higher mineralization temperatures characterized Lucy. The stable isotope systematic and fluid inclusion data determined that the mineralizing fluids in Mariquita deposit are essentially magmatic during the earlier hydrothermal stages, whereas the last stage is the mixing between magmatic and winter meteoric-waters. The mineralizing fluids from Lucy deposit are magmatic in origin. A comprehensive study was performed in the Cu-Co-Zn-Mn ineralization of the Boléo District, and Mn-oxide mineralization along the eastern coast Baja California Sur. The REE and trace element in the Mn-oxides demonstrated the exhalative nature of the mineralizing hydrothermal fluids, and exclude the hydrogenous nature. The stable isotope systematic in ore and gangue minerals, along with the Cu-isotope data helped to decipher the nature of mineralizing and non-mineralizing fluids. The application of Pb, Sr and Re-Os isotope systems was applied to constrain the nature of the fluids involved during the mineralization processes and that the metal sources.

Orientador: Francisco Sérgio Bernardes Ladeira
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências
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Resumo: O rio Mogi Guaçu apresenta, no trecho próximo a Estação Ecológica de Jataí, em Luis Antônio-SP, elevada sinuosidade do canal e inúmeros meandros abandonados causados pela migração lateral e posterior avulsão do curso principal. Essa situação proporcionou uma configuração específica para os solos localizados no terraço e na planície aluvial do rio. Para entender melhor a morfopedogênese desse local, foi feita uma sequência de perfis e tradagens para a investigação da continuidade lateral dos horizontes pedológicos, para depois serem realizadas análises químicas, granulométricas, mineralógicas, micromorfológicas e datações. Identificou-se horizontes ricos em matéria orgânica que ocupam toda a várzea e antigo terraço fluvial, que estão se desenvolvendo sobre um depósito residual de 130.000A.P, conforme datação realizada em um dos perfis. Esses horizontes possuem gêneses diferentes. Um deles, classificado como hístico (H), se desenvolveu preenchendo um antigo meandro abandonado, enquanto os horizontes acima dele, compostos por uma sequência de horizontes A húmicos, foram depositados posteriormente em ambiente de maior energia do rio, num dado momento onde ele já tinha incidido seu talvegue em alguns metros e se deslocado no sentido contrário ao de sua planície aluvial. Esse horizonte foi enterrado por sedimentos aluviais e a preservação da matéria orgânica foi eficiente, apesar de apresentar menores quantidades de carbono orgânico que o horizonte H. A mineralogia mostrou que a Caulinita é o mineral predominante na fração argila, apesar de ocorrerem também Gibbsita e VHE. Esta última seria resultado de neoformação, indicando atual situação de drenagem livre, ou, sua presença é de origem alóctone. A micromorfologia mostrou feições redox ainda preservadas na base do perfil 3, porosidades fissurais associadas à processos de perda de água pela superfície e grandes diferenças granulométricas entre os perfis apresentados, a principal delas se refere à diminuição latente do grau de seleção dos grãos do esqueleto no sentido da vertente para a planície aluvial. As razões molares apontaram para descontinuidades no horizonte 2A em P5 e P3, e entre os horizontes Ah e H, no perfil 4, mostrando distintas condições de pedogênese dentro dos perfis. Os processos de formação desses horizontes estão ligados à migração lateral do rio Mogi Guaçú e incisão do seu talvegue, que proporcionaram condições redutoras para o acúmulo de matéria orgânica, resultando em momentos de maior e menor acúmulo. Com as datações foi possível propor a cronologia da formação do paleoterraço e da planície aluvial nos últimos 130.000 anos e dos solos associados, no entanto, as considerações feitas a respeito da influência do paleoclima e de fatores estruturais não são conclusivas, devido à dinâmica geológica e geomorfológica da área, que é bastante específica
Abstract: The Mogi Guaçu river, near to Estação Ecológica de Jataí (Luis Antônio-SP), shows high sinuosity on its channel and many abandoned meaders caused by lateral migration and main course's avulsion. This situation is responsible by a specific configuration for the soils which are localized at terrace and at the river's alluvial plain. For a better understanding of the local morphopedogenesis, a profiles' sequence and some boreholes were made in order to investigate the lateral continuity of the soil horizons, and then perform chemical analysis, particle size distribution, mineralogy, micromorphology and datings.This process enabled the identification of horizons rich in organic matter which fills the lowland and the old's alluvial plain, which are developing above residual deposits of 130.000B.P, in according to the dating of one of the profiles. These horizons have different genesis. One of them, classified as histic horizon (H), developed filling an older abandoned meander, while the horizons above, compound by a sequence of humic A horizons, were deposited later on high energy river environment, at some point where it has been cut its thalweg in some meters and moved away of the alluvial plain. This horizon was buried by alluvial sediments and the preservation of organic matter was efficient, despite of showing lower amounts of organic carbon than H horizon.The mineralogy has shown that Caulinite is the predominant mineral in clay fraction, although Gibbsite and HIV also exist. HIV may be the result of neoformation, indicating an actual situation of free drainage, or, its presence is allochthounous. The micromorpholy has shown preserved redox lineament on the bottom of profile 3, porosities associated to water loss processes by surface and big granulometric differences between the profiles. One of the biggest differences refers to the grain selection's reduction of the skeleton in the direction of the slope to the alluvial plain. The molar ratios indicated gaps on 2A horizon in the P5 and P3, and between Ah and H horizons, on profile 4, showing different profile conditions of soil forming. The formation process of those horizons is linked with lateral migration of the river Mogi Guaçu and incision of its thalweg, which provides reducing conditions for the amount of organic matter, resulting in higher and lesser moments of accumulation.By datings was possible propose paleoterrace and alluvial plain formation chronology of last 130.000 years and associated soils, although, the considerations made about paleoclimate and structural factors influence aren't conclusive, due to geologic and geomorphologic dynamic of area, that is much specific
Mestrado
Análise Ambiental e Dinâmica Territorial
Mestre em Geografia

Tesis para optar al grado de Magíster en Administración
Autores no envían autorización, para ser publicada en el Portal de Tesis Electrónicas de la U. de Chile.
obar Valenzuela, Pablo [Parte I Análisis estrátegico y de mercado], Venegas Padilla, Tiburcio Antonio [Parte II Análisis organizativo - financiero]
Los relaves mineros son un problema latente para el medioambiente. Si no se considera un manejo posterior a su abandono, pueden ser fuente de diversos inconvenientes de salud para las comunidades aledañas, ya que pueden incidir negativamente en la flora, fauna y cursos de agua disponibles del lugar donde estén insertos. Esto se debe a que aumentan su incidencia negativa por: actividad eólica, lo que provoca inhalación directa de los contaminantes; eventos climáticos lluviosos, que contaminan el agua de riego con la posterior ingesta de alimentos contaminados; movimientos telúricos, que infiltran contaminantes a napas subterráneas, entre otros eventos naturales. La empresa FitoMine tiene por objetivo resolver esta necesidad que tienen hoy las empresas mineras, de manejar adecuadamente los depósitos de relaves provenientes de sus operaciones, con una visión de futuro que cumpla con la actual legislación minera y que vaya aún más allá, generando una propuesta de valor sustentable para la industria en Chile. Este plan de negocios, se enfoca en aportar una solución integrada de gestión y de innovación tecnológica, para la mitigación y manejo medio ambiental de estos depósitos, a través de la técnica de fitoestabilización, que consiste básicamente en la implantación de especies arbóreas nativas en los depósitos terminados (no activos). La fitoestabilización utiliza especies vegetales nativas capaces de resistir y sobrevivir en suelos con altos niveles de metales, con el fin de estabilizar física y químicamente sustratos ricos en metales como es el caso de los depósitos de relaves. Esta opción, al compararse a la tradicional vitrificación o cementación, tiene notables ventajas en cuanto a servicios ambientales y eco sistémicos, pues genera belleza paisajística; aumento de áreas verdes, que con el tiempo se pueden usar para recreación; mayor captura de CO2, recuperación de la cobertura vegetal y hábitats de flora y fauna, generando valor para los clientes, trabajadores y comunidades. Este aspecto es fundamental, dado que los nuevos desarrollos mineros, están y seguirán estando fuertemente condicionados por el trabajo conjunto con las comunidades, otorgando grados cada vez mayores de asociatividad. En este estudio, se muestran las condiciones para la creación de esta empresa, dado el ambiente del mercado y los factores externos complementarios. Especialmente relevante es el marco legal, que obliga a las mineras a dar manejos sustentables a sus operaciones, incluyendo el manejo final y cierre de los tranques de relaves. El servicio ofrecido, considera el estudio de la zona de los relaves e identificación de las especies arbóreas nativas, evaluación del rendimiento de las especies escogidas, plantación de árboles y mantención por los primeros años. Mediante un trabajo riguroso y responsable, se pretende que FitoMine sea reconocida como la empresa líder y de mayor prestigio en fitoestabilización de tranques de relave en Chile. En el estudio se ha determinado, que esta es una buena oportunidad de negocio, en un entorno propicio para su implementación, arrojando valores de TIR de 35.1%, VAN sobre los $1.853 millones, muy positivos avalando su retorno. Un aspecto relevante, es el nivel de capital financiero necesario para iniciar la operación ($600 millones), que estimamos es el principal riesgo para su lanzamiento. La generación de proyectos dependerá en gran medida del acercamiento directo a los ejecutivos del área de sustentabilidad de los potenciales clientes, aportando una solución integral a los requerimientos de cierre de los depósitos de relaves.

Today the problem of waste has gained environmental and economic importance for many countries. Accumulation of waste is transformed into significant danger factor that affects the quality of life and is one of the real threats to environmental security. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/31722

The interest in modeling non-maturing deposits has skyrocketed ever since thefinancial crisis 2008. Not only from a regulatory and legislative perspective,but also from an investment and funding perspective.Modeling of non-maturing deposits is a very broad subject. In this thesis someof the topics within the subject are investigated, where the greatest focus inon the modeling of the deposit volumes. The main objective is to providethe bank with an analysis of the majority of the topics that needs to be cov-ered when modeling non-maturing deposits. This includes short-rate model-ing using Vasicek’s model, deposit rate modeling using a regression approachand a method proposed by Jarrow and Van Deventer, volume modeling usingSARIMA, SARIMAX and a general additive model, a static replicating port-folio based on Maes and Timmerman’s to model the behaviour of the depositaccounts and finally a liquidity risk model that was suggested by Kalkbrenerand Willing. All of these models have been applied on three different accounttypes: private transaction accounts, savings accounts and corporate savingsaccounts.The results are that, due to the current market, the static replicating portfoliodoes not achieve the desired results. Furthermore, the best volume model forthe data provided is a SARIMA model, meaning the effect of the exogenousvariables are seemingly already embedded in the lagged volume. Finally, theliquidity risk results are plausible and thus deemed satisfactory.
Intresset för att modellera inlåningsvolymer utan en kontrakterad förfallodaghar ökat markant sedan finanskrisen 2008. Inte bara sett utifrån ett perspek-tiv att uppfylla krav som ställs av tillsynsmyndigheter, men också sett utifrånbankens investerings-och finansieringsperspektiv.Målet med det här arbetet är att förse banken med en analys av majoritetenav de olika områdena som man behöver ta hänsyn till när man ska model-lera inlåningar utan förfallodatum, men med ett fokus på volymmodellering.I den här rapporten modelleras räntor (kortränta och kontoränta), kontovoly-merna, kontobeteendet samt likviditetsrisken. Detta görs med hjälp av Vasicekför korträntan, en regressionsmetod samt en metod som föreslagits av Jarrowoch Van Deventer för kontoräntan, SARIMA, SARIMAX och en generell ad-ditiv regressionsmetod för volymerna, en statisk replikeringsportfölj baseradpå Maes och Timmermans modell för att imitera kontona och slutligen så mo-delleras likviditetsrisken med ett ramverk som föreslagits av Kalkbrener ochWilling. Alla dessa nämnda modeller appliceras, där det är möjligt, på de treolika kontotyperna: privatkonton, sparkonton samt företagssparkonto.Resultatet är att räntemodelleringen samt replikeringsportföljen inte ger ade-kvata resultat på grund av den rådande marknaden. Vidare så ger en SARIMA-modell den bästa prediktionen, vilket gör att slutsatsen är att andra exogenavariabler redan är inneslutna i den fördröjda volymvariabeln. Avslutningsvisså ger likviditetsmodellen tillfredsställande resultat och antas vara rimlig.

The aim of this dissertation is to analyze the case in point of deposit tracing back its origin in archaic Roman law, following its development from the point of view of the legal protection granted to such institutiom, between Roman law in the Republican age and in the classic epoch, up until its consolidation in the Digest where the discipline is treated organically. Taking a clear diachronical approach, the study ends with a look at the codification of deposit contract in the Italian juridical system and its application in the Italian courthouses and at the Court of Cassation. In detail, this study begins, for illustrative and framing purposes, with a short etymological and lexical analysis of the word 'deposito' and its originary meaning in relation with the Italian language. The Italian language generally points to a tripartite meaning: deposit as the act whereby a certain good is given to somebody who is committed to keep it and return it; deposit as the contract established at the moment of delivery; deposit as the item which has been deposited. The Accademia della Crusca enumerates as many as twenty-four different meanings for the term ‘deposito’, and they are reported here. Following such preliminary considerations, the study then esamine the institution of deposit at its dawning: deposit was not initially recognized as a real contract, but as an agreement whereby a private party ‘the depositor’ would hand in friendly terms to another one - the depositary - an item to be kept in custody and returned in due time. The bond created by the fides that tied the depositary to the depositor was then divinely sanctioned: if the friendly agreement based on fides was violated, the depositario could, hypothetically be considered a homo sacer for having broken the faith (fides rupta) and the subsequent breaking of the pax deorum, namely the relationship of friendship that in the historical age had to remain between men and gods. On the promise of sacertas, descending automatically on the depositary, it is inferred that he could be killed with impunity because the killing was exclusively dependent on divine will on account of the violation of religious and holy precepts. The arguments that sustain such powerful and unprecedented hermeneutical approach are, in the author's modest opinion, evident and univocal, deriving from the oldest source on the institution of deposit ‘Coll. 10. 7. 11.: ex causa depositi lege duodecim tabularum in duplum actio datur, edicto praetoris in simplum ‘that bears witness the penal origin of such institute. This penal conviction in duplum must have necessarily preceded the Law of the Twelve Table, so it is reasonable to conclude that it was justified by the general violation of fides between Roman citizens; and the violation of fides at the dawning of Roman civilization, made the subject sacer. From archaic law, the study then moves to classical law to analyze the formulas in factum and in ius ex fide bona: the former is definitely older - first half of the I century BC- and still has penal associations, whereas the latter - late I century BC- demonstrates the definitive parting from penal law and offers a full and effective protection to the contractors. Having illustrated the substantial differences between these civil actions, the dissertation examines the discipline of deposit contract outlined and handed down to us by fragments included in the Digest. In this analysis we highlight the essential requisites of the deposit contract, indeed not too different from the current ones, except as far as gratuitousness is concerned, that only in Roman Law was part of the case in point and determined the depositary's responsibility only in case of malice. Deposit in the classical age appears to be an actual contract where a depositor transfers to a depositary the movable good so that he guards it and returns it upon request of the depositor. The requisite of the aforementioned contract are, then, the datio rei, a typical element of all actual contract, gratuitousness, an element that distinguishes Roman deposit from Italian law, and the subjective intention of the parties involved to establish a deposit contract. Once the contract is finalized, the sources indicate in the custody and restitution of the item upon request of the depositor the obligations entailed by the contract and binding the depositary alone. From this point of view the deposit contract is a unilateral contract: obligations arise only for the depositary, whereas the depositor is protected by the depositi directa, through which the depositor can reclaim the deposited item at a trial. Lastly, as far as classical deposit is concerned, this study has only taken into account the responsibility of the depositary in case of malice, evidencing a very mitigated representation of malice itself. This dissertation has synthetically considered the special figures of deposit (already existing in Roman law): necessary deposit, irregular deposit and confiscation seizure. Finally, in a diachronical approach, this study has considered the deposit contract as in the article n. 1766 of the Italian Civil Code and its application in Italian jurisprudence.
Il presente elaborato si propone di analizzare la fattispecie del deposito partendo dalle sue origini, risalenti al diritto romano arcaico, seguendone l'evoluzione sotto il profilo della tutela processuale offerta all'istituto, tra il diritto romano dell' età della Repubblica ed il diritto romano della successiva epoca classica, fino al consolidarsi della disciplina raccolta in modo organico ed esaustivo nel Digesto. Con modalità spiccatamente diacronica lo studio si conclude volgendo uno sguardo alla fattispecie codicistica del contratto di deposito nell'ordinamento giuridico italiano e all'applicazione del suddetto presso le aule dei Tribunali e avanti la Corte di cassazione. Nello specifico lo studio inizia, a scopo illustrativo e di inquadramento generale, con una sintetica analisi, sotto il profilo etimologico e lessicale, della parola deposito e del suo significato originario in rapporto alla lingua italiana. La lingua italiana indica in via generale una tripartizione di significato: l'atto con cui si consegna un bene ad altri, che assume l'impegno a custodirlo ed eventualmente restituirlo; il relativo contratto che si conclude al momento della consegna; il medesimo oggetto depositato. E ben ventiquattro sono i significati attribuiti al lemma deposito dall'Accademia della Crusca, di cui si è dato conto. Svolte le suddette considerazioni preliminari, lo studio passa alla disamina dell'istituto del deposito ai suoi albori: la fattispecie del deposito in origine non era riconosciuta siccome un contratto reale, bensì come una forma di accordo in forza del quale una parte privata ‘il deponente’ a titolo di amicizia consegnava all'altra ‘il depositario’ una cosa allo scopo di custodia e di successiva riconsegna. Il vincolo creatosi in forza della fides che legava il depositario al deponente riceveva in questo modo tutela direttamente dalle divinità : a seguito della violazione dell'accordo amicale (fondato sulla fides) instauratosi tra le parti, il depositario, in ipotesi, poteva finanche essere ritenuto homo sacer stante la violazione della suddetta fides ‘fides rupta’ e la seguente rottura della pax deorum, ossia di quel rapporto di amicizia che, in epoca storica, doveva permanere tra uomini e divinità. Sulla premessa della sacertà , discendente in modo automatico, del depositario se ne ricava che il medesimo poteva essere impunemente ucciso da chiunque: tale uccisione sarebbe dipesa esclusivamente dalla volontà delle divinità quale conseguenza della violazione dei precetti di natura religioso-sacrali. Gli argomenti sui quali si fonda simile approdo ermeneutico, certamente forte e mai in precedenza riscontrato, sono ‘a modesto parere di chi scrive’ evidenti ed univoci e si ricavano dalla più antica fonte sull'istituto del deposito ‘Coll. 10. 7. 11.: ex causa depositi lege duodecim tabularum in duplum actio datur, edicto praetoris in simplum’ che testimonia l' origine penale dell'istituto in parola. La suddetta condanna penale nel doppio doveva, necessariamente, preesistere alla stessa Legge delle Dodici Tavole e, pertanto, è ragionevole ritenere trovasse giustificazione nella generale violazione della fides tra i cittadini romani: e la violazione della fides agli albori della civitas romana comportava, come testè detto, la sacertà del soggetto. Dal diritto arcaico, lo studio volge lo sguardo verso il diritto classico e analizza le formule in factum ed in ius ex fide bona: la prima è certamente più risalente ‘prima metà del primo secolo a. C. ‘ e presenta ancora addentellati penalistici, laddove la seconda, successiva ‘seconda metà del primo secolo a. C.’ evidenzia il definitivo distacco dal diritto penale ed offre una piena ed efficace tutela alle parti contrattuali. Messe in luce le differenze sostanziali tra le predette azioni civili, lo studio è passato ad analizzare la disciplina del contratto di deposito venutasi a delineare e tramandataci dai frammenti contenuti nel Digesto. Nell'analisi della disciplina si sono messi in evidenza i requisiti essenziali del contratto di deposito, per vero non dissimili da quelli della fattispecie odierna, ad eccezione della gratuità che solo nel diritto romano era elemento della fattispecie e cosa determinava la responsabilità del depositario per il solo dolo. Il deposito in epoca classica figura, infatti, essere un contratto reale per cui taluno (depositante) trasferisce ad altri (depositario) le detenzione di una cosa mobile, affinchè la custodisca e poi la restituisca a semplice richiesta del deponente. I requisiti del suddetto sono, allora, la datio rei, elemento tipico di tutti i contratti reali, la gratuità, elemento che caratterizza il deposito romano distinguendolo da quello previsto dall'ordinamento giuridico italiano, e l'intenzione subiettiva delle parti di concludere un contratto di deposito. Concluso il contratto di deposito, le fonti indicano nella custodia e nella restituzione della cosa a richiesta del deponente, le obbligazioni nascenti dal contratto di deposito e poste a capo del solo depositario. In questo senso il contratto di deposito è un contratto unilaterale: le obbligazioni nascono in capo ad una sola parte contrattuale, il depositario, laddove l'altra parte contrattuale, il deponente, è tutelata per il mezzo dell' ‘actio depositi directa’, con la quale quest' ultimo potrà in sede processuale recuperare la cosa data in deposito. Infine per quanto riguarda il deposito classico lo studio ha analizzato la responsabilità limitata al solo dolo del depositario, evidenziando una rappresentazione del dolo stesso dai toni abbastanza attenuati. Lo studio ha quindi preso in considerazione sinteticamente le figure speciali di deposito (già presenti nel diritto romano): il deposito necessario, il deposito irregolare ed il sequestro. Infine, in modo diacronico, lo studio ha volto uno sguardo al contratto di deposito di cui all' art. 1766 c.c. e all'applicazione del suddetto offerta dalla Giurisprudenza italiana.

Gossans, the brightly coloured oxidation products of sulphide mineralised rocks, have acted as an exploration target for base and precious metals and sulphur for thousands of years. They are easily identified from remote sensing and field-based reconnaissance, and once found may be drilled to determine the character of mineralisation below. The number of targets drilled could potentially be reduced if gossans overlying significant mineralisation can be discriminated from their field relations, mineralogy and geochemistry. Previous such studies have focussed on porphyry-type systems, with less attention on the generally much lower tonnage volcanogenic massive sulphide (VMS) deposits. However, VMS continue to provide an economically important source of metals in Europe and elsewhere. The Troodos Massif in Cyprus was chosen for this study as it hosts a currently active Cu mine along with historically worked VMS, is little deformed and has a relatively well understood geological framework. Of particular interest are secondary Cu deposits (SCUD) which form due to weathering of primary massive sulphides (PMS). These can be worked at relatively lower financial and environmental cost, and at much lower grades (down to around 0.1 % Cu). The only currently mined SCUD in Cyprus is the Phoenix ore body at Skouriotissa, which lies immediately adjacent to, and structurally below the Phoukasa PMS. The questions addressed in this study are: 1) Do Cypriot PMS that were mined for Cu show original Cu enrichments, or is their elevated Cu content a result of supergene enrichment to form an SCUD? This was addressed by comparing the mineralogical, chemical and S isotopic compositions of PMS mined for Cu with those mined for pyrite only from across the Troodos; 2) Do gossans formed from Cu-rich sulphides show distinctive mineralogical and chemical signatures? The characteristics of gossans known to overlie prospective sulphide bodies were compared with those from barren PMS; 3) What circumstances promote the formation of SCUDs? In particular, did sulphide oxidation occur on the sea floor or in a terrestrial environment? It was considered likely that SCUD formation may require sea floor oxidation because this will result in limited Cu dispersion, due to both sharp pH and redox gradients and limited fluid flow when compared with terrestrial weathering, where the depth to the water table can be considerable. The question was addressed by comparing the field relations, chemistry and S and O isotope compositions of gossans thought to have formed on the sea floor (Skouriotissa - Phoenix) with those generated in a terrestrial setting (Kokkinopezoula, Mathiati and Sia). The remnants of primary VMS deposits mined for Cu in Cyprus (Phoukasa, Sia and Troulli) almost exclusively contain primary Cu sulphides such as chalcopyrite. Secondary Cu sulphides, mainly chalcocite and covellite, are only present in significant concentrations at Phoukasa and Troulli, with Cu oxides being found in Phoenix. At Phoukasa, secondary Cu sulphides have a mean δ34S = 3.69±0.08 ‰ similar to primary pyrite and chalcopyrite (mean δ34S = 3.78±0.08 ‰) suggesting formation from Cu-rich fluids that scavenged S from primary sulphides. Sulphide material collected from copper mines has Cu = 840 to > 10,000 ppm at Phoukasa; 167 to 3573 ppm at Sia; 288 to > 10,000 ppm at Troulli, while the Cu-barren deposits have generally lower Cu grades (Cu = 170 to 433 ppm at Kokkinopezoula; 327 to 1303 ppm at Mathiati north). There are no systematic differences in the S isotope compositions of pyrite between deposits mined for Cu and those not (average δ34S = 1.68, 3.74 and 7.1 ‰ for Cu-rich Sia, Lysos and Phoukasa, and 5.03 and 3.70 ‰ for Cu-poor Kokkinopezoula and Mathiati North sulphides, respectively). No consistent chemical differences (including chalcophile elements) could be identified between gossans overlying Cu-rich as opposed to barren PMS. Gossans overlying the Lysos and Sia Cu-rich PMS, however, show an enrichment in Pb and Zn not observed in other gossans, and umbers, which are chemical sediments associated with VMS systems, often overlying gossans, show strong Cu enrichments in the vicinity of Cu-rich PMS. Umber samples from near the Cu-rich Phoukasa sulphide body contain > 10,000 to 35,400 ppm Cu, while those around Cu-poor Mathiati North contain 669 to 819 ppm Cu. There were no differences in the S isotope compositions of gypsum from sulphide bodies which were Cu-rich (δ34S = 5.9 to 6.9 ‰ for Sia, Phoukasa and Troulli) and Cu-poor (δ34S = 5.0 to 7.3 ‰ for Kokkinopezoula, Mathiati North). Regarding the environment of formation of SCUDs, an initial submarine oxidation of the Phoukasa VMS is considered likely as it is immediately overlain by marine pelagic sediments, while all other deposits studied are overlain by volcanics. In addition, volcanics in the vicinity of Phoukasa show large negative Ce anomalies (Ce/Ce* = 0.90 to 0.38, average = 0.71), consistent with sea floor alteration, compared with other localities such Kokkinopezoula (Ce/Ce* = 0.89 to 1.08, average = 0.97) and Sia (Ce/Ce* = 0.92 to 1.03, average = 0.99). Unfortunately, the S isotope composition of gypsum could not be used to determine the nature of the gossan-forming environment. Gypsums from all locations (average δ34S = 6.74±0.08 ‰) have δ34S values similar to, but slightly 34S enriched compared with their associated sulphides (average δ34S = 2.9±0.08 ‰) which indicates that their S isotope signature largely reflects that of S released during sulphide oxidation, as opposed to evaporation of sulphate-rich waters or direct precipitation from a similar solution (i.e., seawater). However, the oxygen isotope composition of gypsum (average δ18O = 6.2 ‰) from Sia (average δ18O = 2.4 ‰) reflects a mixture of atmospheric O (δ18O = 23.6 ‰) and Mediterranean meteoric water O (δ18O ≈-5.0 ‰), indicating a terrestrial environment of formation. Gypsum from Skouriotissa has an average δ18O = 6.6 ‰ which most likely indicates a combination of seawater and seawater-dissolved O (δ18O ≈23.5 ‰), despite some overlap with the composition of meteoric water and atmospheric O. In summary, it is proposed that the currently unique nature of Skouriotissa as hosting the only major SCUD in Cyprus is due largely to initial sea water alteration of the Phoukasa PMS resulting in limited Cu dispersion and localised Cu enrichment within the primary ore body. Subsequent uplift and alteration of the Phoukasa PMS led to the formation of a relatively high grade SCUD in the Phoenix deposit. The main outcomes of the study are a series of models for the development of gossans and associated lithologies in terrestrial and seafloor weathering environments in Cyprus. These incorporate a new term (retali) for acid leached volcanics in the footwall of PMS, and exploration-relevant field, mineralogical and chemical criteria for their discrimination from gossans, which overlie PMS. In agreement with an existing model, the formation of the Phoenix SCUD is interpreted as having been due to the downward migration of Cu-bearing acid fluids from the seafloor oxidation of the upper parts of the Phoukasa deposit. Secondary Cu mineralisation is thought to have taken place within the relatively reducing environment below the water table in lavas stratigraphically below the Phoukasa deposit. That the formation of SCUDs may require seafloor sulphide oxidation, and that this can be recognised in the mineralogy and chemical compositions of associated volcanics and gossans, provides new exploration criteria for SCUDs. However, it should be noted that the Phoenix deposit was the only SCUD examined in this study, and that this model should therefore be tested elsewhere.

Carbonaceous engine deposits tend to accumulate on most of the inner surfaces of the car engine. The presence of these deposits leads to a deteriorated efficiency of the engine and a number of adverse effects, such as higher propensity of the engine to knock. It has been proposed that selective adsorption of some of the fuel components in the porous deposits (and changing composition of the pre-combustion fuel) could be a contributing mechanism of the diminished efficiency of the engine. This, as well as other mechanisms of the deposits action, crucially depend on the porous structure of the material. Therefore, the aim of this investigation is to develop a method, which is able to accurately characterize the internal porous structure of the engine deposits and predict their adsorption properties at different conditions. This should allow us to assess whether the selective adsorption of fuel components is indeed a plausible contributing mechanism to the diminished performance of the engine. Accurate characterization of the engine deposits faces several difficulties due to their complex porous structure and chemical composition. A widely adopted approach in the characterization of activated carbons, which combines molecular simulation, specifically grand canonical Monte Carlo (GCMC) in slit pores, and experimental adsorption isotherms, is the starting point for the method suggested in this work. In this thesis, we will demonstrate that, by systematic modification of the solid-fluid interaction in the molecular simulation, we are able to correctly account for the chemical structural heterogeneity of the samples used. The new parameters of solid-fluid interaction allow us to extract representative pore size distributions and investigate the adsorption properties under different conditions of temperature and pressure, based on the obtained pore size distribution. Specifically, using the experimental data from a single ethane isotherm at 278K we accurately predict ethane adsorption at other temperatures and in different samples. Additionally, the proposed method is able to predict the adsorption of more complex hydrocarbons, i.e. n-butane and isobutane. The performance of the method is assessed by comparing the simulations results with the experimental adsorption measurements data on the engine deposits samples. Another important capability of the method is that it enables us to generate adsorption predictions of two key components commonly used to represent the combustion properties of the fuel, n-heptane and isooctane. We explore the equilibrium adsorption properties of these components based on the determined pore size distributions of the deposit samples. The results presented in the thesis highlight the importance of the adsorption in the internal porous structure of the engine deposits. The present study reinforces the value of molecular simulation combined with a limited number of experimental measurements, to accurately characterize heterogeneous carbonaceous materials and to make predictions at different conditions with sufficient precision.

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
O presente trabalho forneceu informações originais para auxiliar o entendimento dos fenômenos básicos que governam a deposição de parafina em dutos. O programa de pesquisa estudou questões relevantes, ainda em aberto na literatura, relacionadas à formação, crescimento e envelhecimento de depósitos de parafina. Com este objetivo, foi desenvolvido um programa experimental seguindo a estratégia de conduzir experimentos simples, empregando seções de teste em escala de laboratório, com condições de contorno e iniciais bem definidas, e empregando fluidos de teste simples e com propriedades conhecidas. As medidas foram realizadas em seções de testes retangular e anular, ambas especialmente projetadas para permitir medidas ópticas da evolução temporal e espacial da espessura dos depósitos. As seções de testes foram equipadas com um sensor de fluxo de calor, sondas de temperatura móveis e janelas para amostragem de depósitos, que permitiram a medição de grandezas importantes como, condutividade térmica do depósito sob condições de escoamento, perfis de temperatura dentro do depósito, evolução da temperatura da interface depósito-líquido, e composição do depósito. A variação espacial e temporal da espessura do depósito foi medida para diferentes valores do número de Reynolds laminar. Excelente concordância foi obtida entre os valores medidos e previsões de um modelo numérico desenvolvido previamente em nosso grupo de pesquisa. Medidas da evolução temporal da temperatura da interface depósito-líquido mostraram que a temperatura da interface evolui de um valor igual à temperatura inicial de aparecimento de cristais da solução, TIAC, até a temperatura de desaparecimento de cristais, TDC, a medida que o depósitos cresce até sua espessura de regime permanente. A sonda de temperatura foi utilizada na medição de perfis transversais de temperatura dentro do depósitos sob condições de escoamento. A comparação destes perfis com soluções teóricas apontaram para a possibilidade de ocorrência de escoamento dentro da matriz porosa do depósitos. As medições da condutividade térmica do depósitos sob condições de escoamento não apresentaram qualquer efeito da taxa de cisalhamento imposta, para a faixa de número de Reynolds investigada. Variações transversais da condutividade térmica do depósitos indicaram a presença de líquido próximo à parede fria. Amostras do depósitos foram obtidas e analisadas por cromatografia gasosa de alta temperatura para a faixa de número de Reynolds laminares investigadas, e para diferentes durações dos experimentos de deposição. As análises indicaram que as distribuições de carbono das amostras de depósitos apresentaram um deslocamento em direção aos maiores números de carbono com o aumento do Reynolds e do tempo de deposição, caracterizando o processo de envelhecimento do depósito. As distribuições do número de carbono apresentaram um comportamento assintótico com o número de Reynolds, para amostras obtidas dos trechos finais dos comprimentos de deposição da seção de testes anular.
The present research provided original information to aid the understanding of the physical mechanisms governing wax deposition in pipelines. The research program addressed a number of relevant open questions in the literature regarding the formation, growth and aging of the wax deposit layer. To this end, an experimental program was devised, following a strategy of conducting simple experiments, employing lab-scale test sections with well-defined boundary and initial conditions, and using simple test uids with known properties. Measurements were performed in a rectangular and in an annular test section, both especially designed to allow for optical measurements of the time evolution of the spatial distribution of the wax deposit thickness. The test sections were equipped with heat ux sensor, temperature traversing probes and deposit sampling ports that allowed the measurement of relevant local information on the deposit, such as, thermal conductivity under owing conditions, temperature profiles within the deposit, deposit-liquid interface temperature, and deposit composition. The temporal and spatial evolution of the deposit layer were measured for different values of the laminar ow Reynolds number. Excellent agreement was obtained between measured values of the deposit thickness and predictions from a numerical model developed previously in our research group. Measurements of the evolution of the deposit-liquid interface temperature have shown that the interface temperature evolves from a value equal to the solution wax appearance temperature, WAT, to the wax disappearance temperature, WDT, as the deposit grows to attain its steady state thickness. The temperature traversing probe was employed to obtain information on the temperature profiles within the wax deposit layer under owing conditions. A comparison of the measured temperature profiles within the deposit with the theoretical solutions, indicated the possibility of convective transport in the deposit. Measurements of the deposit thermal conductivity under owing conditions did not reveal any effects of the imposed shear rate, for the range of Reynolds numbers investigated. Local variations of the thermal conductivity across the deposit layer indicated the presence of liquid close to the cold wall. Deposit samples were obtained and analyzed by high temperature gas chromatography, for the range of the laminar Reynolds numbers tested and for different durations of the deposition experiments. The analyzes revealed that the carbon distributions of the deposit samples presented a shift toward higher carbon numbers both, with increasing deposition time and Reynolds number, characterizing the aging process of the deposit. The carbon number distributions were seen to display an asymptotic behavior with Reynolds number, for samples obtained from the final portion of the longer deposition lengths of the annular test section.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.
Includes bibliographical references.
Combustion chamber deposits are found in virtually all internal combustion engines after a few hundred hours of operation. Deposits form on cylinder, piston, and head surfaces that are in contact with fuel-air mixture during the engine cycle. The effects of deposits include increased engine-out NOx emissions, octane requirement increase, and changes in flame speed and thermal efficiency. A framework is developed for examining the physical and chemical processes that contribute to the formation of combustion chamber deposits. First, a hypothesis for the general mechanism of deposit formation is developed from a review of previous work on this issue. The key features of this mechanism are formation of deposit precursor species from fuel and air as the flame quenches at the engine wall, diffusive and convective transport of these species to the wall, and condensation or adsorption at the wall surface. The experimental system and methodology developed in this work are meant to provide insight into the interactions between these processes, and in particular to study the chemical mechanisms that contribute to the formation of deposit precursor species. A cooled low pressure flat flame burner is used to produce steady-state propane-air flames doped with toluene, a known deposit forming species.
(cont.) Profiles of concentrations and temperature are measured using infrared spectroscopy and gas chromatography techniques. In conjunction with the experiments, a one-dimensional numerical model is developed, capable of simulating flame quenching with deposition over a range of conditions extending from the low pressure, steady state burner experiments to high pressure, rapid transient engine conditions, using chemical mechanisms of precursor formation that may be determined experimentally. Modeling of deposition with simplified chemical mechanisms reveals that deposition by condensation can reproduce trends observed in experiments by other researchers; however, adsorption could still be a contributing factor. Experimental observations of toluene-doped flames show the formation of oxygenated compounds such as benzaldehyde and benzofuran, which are likely deposit precursor candidates. The methodology developed in this thesis shows promise for determining deposit precursor identities and formation mechanisms for important fuel components, and for clarifying the role of gas-phase processes in the formation of combustion chamber deposits.
by Christopher O'Brien.
Ph.D.

Critical metals are elements essential to high-tech industry and green technology which are associated with a significant supply risk. Diversifying supplies of these elements is therefore a high priority. Porphyry copper deposits contain potentially economic enrichments of some of these elements, namely rhenium, platinum group elements (PGEs), bismuth and tellurium. This thesis investigates the source, transport mechanism and distribution of these critical elements in two post-collisional Tethyan porphyry deposits. The Muratdere Cu-Mo (Au-Re) porphyry deposit, Turkey, described here for the first time, contains two generations of molybdenite with contrasting Re concentrations. The early, Re-poor molybdenites have magmatic δ34SCDT values, while the late, vein hosted Re-rich molybdenite has δ34SCDT values matching those of the surrounding country rock suggesting that the additional Re has been sourced from hydrothermal fluid-country rock interaction. The Skouries Cu-Au porphyry deposit, Greece, is PGE, Te and Bi enriched. In contrast to Muratdere, Skouries is shown to be an orthomagmatic system hosted by a series of overprinting dykes, with the metal enrichment hypothesised to have been provided by periodic mafic recharge of a deeper source magma chamber. The mineralising fluids in Skouries are shown to have been highly oxidised and hypersaline with complex cation chemistry (Na, K, Fe, Mn and Ca), and with the overall fluid evolution progressing from an early CO2 rich fluid to a later brine. The PGEs in the deposit are located in the main hypogene mineralising veinsets, associated with potassic alteration, and are found to be hosted in bismuth and tellurium complexes. A variety of platinum group minerals are identified, including sopcheite (Ag4Pd3Te4) and sobolevskite (PdBi). LA-ICP-MS of fluid inclusions, combined with microthermometry, has shown gold, bismuth and palladium to be hydrothermally transported by high temperature ( > 500°C), high salinity ( > 65 wt% NaCl+KCl) and highly oxidised fluids, and a bismuth-tellurium collector model is proposed to allow concentration of palladium from under-saturated fluids into platinum group minerals. High semi-metal (Te and Bi) contents in porphyries are therefore proposed to be an indicator of PGE enrichment.

Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1999.
Includes bibliographical references.
At present, very little is known about the mechanisms that control flow and transport through wetland deposits. Therefore, the objective of this research was to investigate the factors that influenced flow in wetland soils. To accomplish this, Column Experiments, run on a specialized permeameter, were conducted on both re-sedimented and undisturbed wetland soil specimens. During these experiments, sodium chloride (NaCl) tracer was injected into the soil specimen, and its breakthrough was monitored concurrently with other parameters, such as flow velocity and hydraulic gradient. Subsequently, the breakthrough data collected during the Column Experiments were fit using both the One-Region and Two-Region transport models, and the fit results were analyzed and compared to the geotechnical data collected for the soil. The data collected during the experimental program indicate enormous complexity in the mechanisms controlling flow and transport through wetland soils. From their analysis the following observations were made: First, even though wetland soils are considered to be two-region soils, having both an effective and an immobile porosity, the One-Region model was able to describe Sodium Chloride breakthrough in the soil. This indicates that the NaCl tracer was not interacting with the immobile region of the specimen. Second, the results demonstrated that wetland soil hydraulic conductivity is highly variable and sensitive to volume of flow. In fact, hydraulic conductivity was seen to decrease irreversibly by up to 6% per pore volume of flow. It was also found that hydraulic conductivity was sensitive to increases in pore water salt concentration, and to the flushing out of salts from wetland specimens. Finally, it was observed that, for the most part, large changes in hydraulic conductivity did not correspond to changes in the specimen's effective pore size or pore distribution. In fact, unless salt concentrations were increased drastically, the effective pore space remained invariant over an order of magnitude change in soil hydraulic conductivity. This suggests that changes in soil hydraulic conductivity might be due to increases or decreases in the number of flow channel constrictions in a specimen. From the results of this research it is hypothesized that the number of flow channel constrictions increased when flow and a decrease in salt concentration mobilized organic and mineral particles, which collected and clogged narrow pore throats along the flow channels. It is also hypothesized that the number of flow channel constrictions decreased when increases in pore water salt concentration causect organic fibers along the flow channel walls to coil.
by Lana A. Aref.
Sc.D.

Carlin-type, fine-grained, "invisible" or Disseminated Replacement Type gold-silver deposits are all different names for a major new type of ore deposit that is currently being extensively developed in the Western United States. This type of deposit is now being found elsewhere. Thus a descriptive empirical model that emphasizes the geological and geochemical environment of formation is needed to assist the mining industry in the search for similar deposits. These deposits are typically formed in carbonaceous, silty dolomites and Iimestones or mineralization calcareous siltstones rocks and is exceedingly fine-grained is disseminated in the and claystones. host sedimentary Gold-silver , ore. Primary alteration usually less than one micron in size in unoxidized types include decalcification, argillitization, silicification resulting in the and pyritization. Silicification is commonly intense formation of jasperoid bodies which may be the host to higher grade ore. Supergene alteration is dominated by oxidation resulting in the formation of numerous oxides and sulphates and the release of gold from its association with sulphides and organic carbon. elements are As, Ba, Hg, Sb, and TI. Commonly associated trace Available geological, geochemical, fluid inclusion and stable-isotope studies lead to the conclusion that a circulating hydrothermal system is the important factor necessary for gold-silver concentration and deposition. A direct genetic or only casual relation between are deposition and discrete igneous formations remains unclear. However, it is considered that volcanism provided the source of heat necessary for the generation of a circulating hydrothermal system. High angle faults and fold structures facilitate transport and are of prime importance in directing are fluids to favourable host lithologies. The host rocks, overwhelmingly carbonate - rich, include those whose original and/or altered compositions and resulting permeability provide favourable sites for the precipitation of disseminated gold. The processes specialized. resulting Any th ick in the formation of these deposits are section of carbonate rocks has the potential not to produce Disseminated Replacement Type deposits wherever underlying igneous activity has developed a hydrothermal system

Three bitumen-hosted ore deposits from Peru, Argentina and Chile are described. These deposits (now abandoned) contain diverse mineral assemblages and were mined for vanadium (Minasragra, Peru), uranium (Cerro Huemul, Argentina) and copper (Copiapó, Chile). Highly integrated geological and geochemical studies have enabled the construction of paragenetic sequences and genetic models for these deposits. The Minasragra deposit was a bitumen-hosted vanadium orebody located within the Central Peruvian Andes. It was characterised by a highly unusual and world-unique mineral assemblage which included the vanadium sulphide mineral, patronite. Paragenesis is divided into four distinct phases and deposit genesis is linked to the extreme alteration of an in situ vanadium and sulphur-rich bitumen vein catalyzed by the intrusion of a high-level dyke suite. Cerro Huemul is a bitumen-hosted sandstone-type U-Cu deposit located within continental facies in the Neuquén Basin. Petrographic studies of bitumens and ore species coupled with fluid inclusion analysis enable reconstruction of fluid flow through this sandstone unit. Mineralization is divided into three paragenetic stages and is integrated into a regional and deposit-specific genetic model for ore deposition. The Copiapó study focuses on an extensive andesite lava horizon of Lower Cretaceous age which contains a diverse suite of copper sulphide minerals in intimate association with solid bitumen. Petrographic studies of ore and bitumen species enable the construction of paragenetic sequence which is divided into three mineralizing stages. All three bitumen-ore deposits formed due to the presence of solid bitumen and each case study investigates the role that bitumen played in the mineralizing process. Collectively these studies provide detailed insight into mineralization processes at bitumen-hosted ore deposits and highlight the versatility of bitumens to economically-concentrate a wide range of metals and minerals. A synopsis of the formation of all bitumen-type deposits (solid bitumen veins and bitumen-hosted ore bodies) is presented and ideas regarding the potential of mineral exploration for organo-metallic deposits within the Andean Cordillera are outlined.

The objective of this report is to carry out a pre-study and develop a framework for how the liquidity and interest rate risk of a bank's demand deposits can be modeled. This is done by first calibrating a Vasicek short rate model and then deriving models for the bank's deposit volume and deposit rate using multiple regression. The volume model and the deposit rate model are used to determine the liquidity and interest rate risk, which is done separately. The liquidity risk is determined by a liquidity quantile which estimates the minimum deposit volume that is expected to remain in the bank over a given time period. The interest rate risk is quantified by an arbitrage-free valuation of the demand deposit which can be used to determine the sensitivity of the net present value of the demand deposit caused by a parallel shift in the market rates. Furthermore, an immunization and a replicating portfolio are constructed and the performances of these are tested when introducing the same parallel shifts in the market rates as in the valuation of the demand deposit. The conclusion of this thesis is that the framework for the liquidity risk management that is developed gave satisfactory results and could be used by the bank if the deposit volume is estimated on representative data and a more accurate model for the short rate is used. The interest rate risk framework did however not yield as reliable results and would be more challenging to implement as a more advanced model for the deposit rate is required.
Målet med denna rapport är att utveckla ett ramverk för att bestämma likviditets-och ränterisken som är relaterad till en banks inlåningsvolym. Detta görs genom att först ta fram en modell för korträntan via kalibrering av en Vasicek modell. Därefter utvecklas, genom multipelregression, modeller för att beskriva bankens inlåningsvolym och inlåningsränta. Dessa modeller används för att kvantifiera likviditets- och ränterisken för inlånings-volymen, vilka beräknas och presenteras separat. Likviditetsrisken bestäms genom att en likviditetskvantil tas fram, vilken estimerar den minimala inlånings-volymen som förväntas kvarstå hos banken över en given tidsperiod. Ränterisken kvantifieras med en arbitragefri värdering av inlåningen och resultatet används för att bestämma känsligheten för hur nuvärdet av inlåningsvolymen påverkas av ett parallellskifte. Utöver detta bestäms en immuniseringsportfölj samt en rep-likerande portfölj och resultatet av dessa utvärderas mot hur nuvärdet förändras givet att samma parallellskifte i ränteläget som tidigare introduceras. Slutsatsen av projektet är att det framtagna ramverket för att bestämma likviditetsrisken för inlåningen gav bra resultat och skulle kunna implementeras i dagsläget av banken, förutsatt att volymmodellen estimeras på representativ data samt att en bättre modell för korträntan används. Ramverket för att bestämma ränterisken gav dock inte lika tillförlitliga resultat och är mer utmanande att implementera då en mer avancerad modell för inlåningsräntan krävs.

The Higdon deposit is located on the east flank of the St. Francois Mountains, approximately 11.5 km NE of Fredericktown, MO in the Mine LaMotte-Fredericktown district of the world renown Southeast Missouri (SEMO) region of Mississippi Valley-type (MVT) deposits. It was discovered in the 1950s and an attempt to mine the deposit was made in the 1960s. In the 2000s the importance of the Higdon deposit increased after extensive exploration by The Doe Run Mining Co. revealed a larger deposit, greater Ni-Co content than initially estimated and the presence of a low grade Unconformity-type Uranium deposit, similar to those of the Athabasca Basin in Canada. The overall paragenetic sequence, stratigraphy and stratigraphic controls of the Higdon deposit resembles those present in other SEMO MVT deposits located at the east flank of the St. Francois Mountains. The stratigraphy includes the Cambrian formations: Eminence, Potosi, Derby-Doe Run, Davis, Bonneterre and Lamotte which unconformably overlies Precambrian granitic intrusions. A common feature is the presence of collapse breccias especially at the base of the Bonneterre Formation and a relatively thin Lamotte Formation. Fine-grained, disseminated sulfides of Fe, Pb, Zn, Co and Ni are hosted in the lower one third of the Bonneterre Formation and upper two thirds of the Lamotte Formation, in a series of grainstone beds, open spaces in collapse breccias, near pinch outs of the Lamotte Formation against basement highs. Disseminations and nodules of pitchblende (uraninite) occur through the entire Lamotte Formation. The Higdon deposit differs in several important ways from the deposits of the Viburnum Trend on the west flank of the St. Francois Mountains. These differences include a distinctly lower stratigraphic interval of collapse breccias and mineralization, greater abundance of Co-Ni minerals, presence of pitchblende, and a significant fault control of mineralization. Several regionally extensive high angle faults aligned parallel to the NW-striking Simms Mountain and Mine LaMotte fault systems bound the deposit, especially the high Ni-Co-U portion. Petrographic and microprobe studies at Higdon revealed a mineral paragenetic sequence of uraninite (pitchblende, within a carbon matrix), pyrite, marcasite, chalcopyrite, bravoite, siegenite, gerdorsffite, sphalerite and galena. These minerals were deposited in four different stages: (1) a U dominated stage that precipitated the pitchblende during Early Ordovician to Permian time; (2) a Fe sulfide dominated sulfide characterized by pyrite, marcasite and bravoite; (3) a Cu-Co-Ni stage dominated by chalcopyrite and siegenite, and (4) a Zn-Pb stage characterized by the precipitation of sphalerite and galena. Precambrian uraniferous granitic intrusions in the vicinity of the Higdon deposit supplied the U for the pitchblende mineralization. At Higdon the U mineralization represents an overlapping deposit in an otherwise MVT system. This required leaching by fluids migrating through the basement along high angle faults and U precipitation in a reducing environment as the fluids encountered the Lamotte Formation. The Ni and Co were possibly leached from mafic and ultramafic intrusions along the Reelfoot Rift or from the Precambrian basement and transported to the Higdon area by fluids migrating along the regional NW-trending faults. Mixing with connate Pb-Zn brines moving laterally through the Lamotte Sandstone and other permeable units may have triggered the sulfide precipitation. Finally, the Higdon deposit is anomalous in the tonnage and grade of its Ni-Co resource (0.17 % Ni, 0.14 % Co) with significant values contained in siegenite (30.9 % Ni, 23.9 % Co), bravoite (0.04 % Ni, 6.3 % Co), gerdorsffite (26.1 % Ni, 8.0 % Co) and marcasite-pyrite (0.3 % Ni, 0.2 % Co).

The Viking Age (800–1050 A.D.) is also called the “Silver Age”. Despite the fact that no silver mines were in use in Sweden at that time, most of the landowners for one reason or another had a lot of precious metal stored in their homes. Alone the Island of Gotland has found over 700 different hoards of which around 400 of these hoards have been excavated over the last 100 years. Archeologists are debating whether all this precious metal had been brought to the island by traders from the east, or if it came from the Viking raids in the west. Besides the coins, thousands of pieces of silver have been recorded. The intention of this essay is to attempt to clarify if it is possible to find differentiating factors between the hoards and to classify categories of these precious metal deposits. I indeed, such classifications and categorizations are achievable in the research findings in this paper.

Orientador: Giorgio Basilici
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências
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Resumo: Os lençóis de areia eólica são sistemas deposicionais constituídos em áreas de morfologia plana ou ligeiramente ondulada. As formas de leito predominantes nos lençóis de areia são as marcas onduladas de vento. Tais formas de leito podem ocorrer em comboios ou compondo zibars. Os zibars são formas de leito similares às dunas. Nos zibars não há geração de estratos de queda. Embora muitos estudos reconheçam sistemas de deposição eólica pré-cambrianos, poucos são direcionados aos lençóis de areia eólica. Igualmente negligenciados são os zibars. A Formação Bandeirinha é a unidade inferior do Supergrupo Espinhaço. Depósitos de arenitos vermelhos intercalados a conglomerados intraformacionais compõem esta unidade. Três elementos arquiteturais foram individualizados: zibars, dunas com faces de deslizamento e canais efêmeros. Os depósitos de zibars são arenitos finos a grossos, moderadamente bem selecionados, constituídos por sets de arenitos com laminações planas e paralelas, de geometria tabular ou em cunha. Os sets ocorrem sobrepostos, separados por superfícies truncadas, e constituem cosets. Os depósitos de dunas com faces de deslizamento são arenitos finos a médios, muito bem selecionados, que ocorrem na forma de corpos de geometria lenticular. Os depósitos de canais efêmeros são constituídos por corpos de conglomerados intraformacionais, clasto-suportados, de base côncava, os quais ocorrem em contato erosivo sobre os estratos de arenitos. As superfícies erosivas, de contato entre arenitos e conglomerados, têm amplitude regional. A Formação Bandeirinha é interpretada como uma sucessão sedimentar formada em um lençol de areia eólica dominado por zibars. A alternância entre depósitos de arenitos eólicos e conglomerados revela variações climáticas de ordem regional, onde a deposição eólica (clima seco) era interrompida por deposição subaquosa (clima mais úmido). Neste lençol de areia, o balanço entre entrada e saída de materiais clásticos foi sempre positivo, a construção eólica foi contínua nos períodos mais secos. A estabilização do sistema foi resultado dos processos de cimentação no substrato. A subsidência tectônica foi o principal mecanismo de preservação do sistema eólico
Abstract: The aeolian sand sheets are depositional systems formed in areas with flat or slightly undulating morphology. The predominant bedforms in sand sheets are climbing wind ripples. These bedforms may occur in convoys or composing zibars. The zibars are similar to dunes, but without avalanching faces. Although many studies recognise aeolian Precambrian systems, few works deal with aeolian sand sheets. Equally neglected are the zibars. The Bandeirinha Formation is the lower unit of the Espinhaço Supergroup. Deposits of red sandstones intercalated with intraformational conglomerates compose this unit. Three architectural elements are recognised: zibars, dunes with slip faces and ephemeral channels. Deposits of zibars are fine to coarse grained sandstones, moderately well sorted, and composed by sets of planar-parallel laminations sandstones, in tabular geometry. The sets are superimposed and occur separated by truncated surfaces that constitute cosets. The dunes with slip face are fine to medium grained, very well sorted, and occur as lenticular bodies. The ephemeral channel deposits consist of intraformational conglomerates, clast-supported, with concave erosive basal surface on the sandstone strata. The erosive surfaces of the conglomerates seem to have a regional extension. The Bandeirinha Formation is interpreted as an aeolian sand sheet dominated by zibars. The transition between aeolian sandstones and conglomerates reveals climate variations of regional range, where aeolian deposition, which corresponds to dry climate phase, was interrupted by subaqueous deposition, in more humid climate. During the sand sheet deposition, the balance between input and output of clastic materials was always positive, the aeolian construction was continuous. The stabilization of the aeolian system was result of cementation processes of shallow depth. The tectonic subsidence was the main mechanism of preservation of the aeolian system
Mestrado
Geologia e Recursos Naturais
Mestre em Geociências