Under effective compression, impingement of opposing rough surfaces of a fracture can force the walls of the fracture apart during slip. Therefore, a fracture’s surface roughness exerts a primary control on the amount of dilation that can be sustained on a fracture since the opposing surfaces need to remain in contact. Previous work has attempted to characterize fracture surface roughness through topographic profiles and power spectral density analysis, but these metrics describing the geometry of a fracture’s surface are often non-unique when used independently. However, when combined these metrics are affective at characterizing fracture surface roughness, as well as the mechanisms affecting changes in roughness with increasing slip, and therefore changes in dilation. These mechanisms include the influence of primary grains and pores on initial fracture roughness, the effect of linkage on locally increasing roughness, and asperity destruction that limits the heights of asperities and forms gouge. This analysis reveals four essential stages of dilation during the lifecycle of a natural fracture, whereas previous slip-dilation models do not adequately address the evolution of fracture surface roughness: (1) initial slip companied by small dilation is mediated by roughness controlled by the primary grain and pore dimensions; (2) rapid dilation during and immediately following fracture growth by linkage of formerly isolated fractures; (3) wear of the fracture surface and gouge formation that minimizes dilation; and (4) between slip events cementation that modifies the mineral constituents in the fracture. By identifying these fundamental mechanisms that influence fracture surface roughness, this new conceptual model relating dilation to slip has specific applications to Enhanced Geothermal Systems (EGS), which attempt to produce long-lived dilation in natural fractures by inducing slip. / Geology

Porosity is a fundamental characteristic of rock critical to its mechanical and hydrologic behavior, yet a study of the open and accumulated healed porosity of nine core samples from Newberry Volcano shows that different measurement methods produce significantly different estimates of pore volume and structure. This study compares traditional 2D point count, petrographic image analysis, and 3D x-ray Micro Computed Tomography (micro CT) measurement of porosity primarily derived from fracture slip and dilation. The set of measurements quantifies the discrepancy among measurement methods and provides a basis for assessing how this uncertainty depends on geologic factors including the stage of fracture development, and the size and connectivity of the pores. This comparison reveals that detailed petrographic mapping provides the most accurate characterization of fracture porosity, and its history of development, owing to its high spatial resolution and accuracy of phase identification as well as insights afforded from mineralogic and textural relationships. However, this analysis lacks the three-dimensional characterization necessary to determine pore shape and interconnectedness, especially in highly anisotropic and heterogeneous fracture porosity. Micro CT does characterize the three dimensionality of pores, and thus although it consistently underestimates porosity due to non-uniqueness of phase densities and limitations in resolution, and is difficult to post process, this method can usefully augment the petrographic analysis. High resolution mapping of petrographic thin sections also provides a means to characterize the roughness of fracture surfaces across multiple cycles of slip, related dilation, and healing. Analysis of 19 slip events on a small, early stage fracture experiencing less than mm-scale slip, indicates that this roughness is preserved across multiple slip events and is consistently associated with dilation recorded by the accumulation of layers of precipitated cement. Initially, characteristic length scales intrinsic to rock such as the primary grain and pore size distribution of the > 0.2 mm size fraction significantly influence the roughness of fractures, until the dominant mechanism of fracture growth becomes linkage among macroscopic fractures. This correlation among primary rock characteristics such as grain size, fracture roughness, repeated fracture slip, and dilation provides a potential method to assess the key attributes promoting dilatant, self-propping fracture slip necessary for successful stimulation to generate an Enhanced Geothermal System. Comparison to more developed fractures characterized by the development of fault rock suggest such stimulation is most successful for fractures sustaining small slip of a few millimeters or less during single slip events. / Geology

In this thesis, the potential of enhanced geothermal system to provide adequate energy to a 10 MW electricity power plant from Prairie Evaporite Formation of Williston Basin was investigated. This formation partly consists of halite with low thermal resistance and high thermal conductivity, which translates into a lower drilling length to reach the desired temperature, comparing to other rock types. To this end, two numerical models with experimental data in south-west Manitoba (i.e. Tilston) and south-east Saskatchewan (i.e. Generic) were designed. The thermal reservoirs were located at 1.5 km (Tilston site) and 3 km (Generic site) with approximate thicknesses of 118 m. Considering an injection brine of 6% NaCl at 15°C, the final derived temperature at wellhead of the production wells were 43°C and 105°C respectively. Finally, the Generic site was concluded as a suitable candidate for electricity production by providing higher surfaced fluid temperature than the minimum of 80°C. / February 2017

Orientador: Guilherme de Paula Nogueira / Resumo: Comumente o biotipo é o principal critério utilizado para predicão da puberdade precoce em novilhas Nelore. Este experimento comparou os possíveis efeitos do peso a desmama (PeD), peso ao sobreano (PeS), espessura de gordura subcutânea na garupa (EGSG), concentrações séricas de IGF-I (IGF-I) e insulina ao sobreano (Ins), ganho diário de peso: até a desmama (GD), entre a desmama ao sobreano (GS) e do nascimento até o sobreano (GT), além de escores visuais de conformação (C), precocidade (P) e musculatura (M) avaliados tanto na desmama como no sobreano, sobre a idade à primeira prenhez e desempenho na primeira estação de monta (EM) de novilhas Nelore. Para isso foram utilizados dados de 241 novilhas, produzidos pela P@RM agropecuária, estas nascidas entre maio e setembro de 2016. As mesmas permaneceram à pasto num único lote a partir da desmama. Avaliações de CPM e mensuração do peso corporal em jejum alimentar e hídrico após12h foram realizadas na desmama e repetidas após ganho mínimo de 50kg de peso. Foi iniciada a EM no dia seguinte à avaliação de sobreano, quando as novilhas foram submetidas ao protocolo de indução de puberdade e duas inseminações artificiais em tempo fixo, e posterior repasse com touro. Para a idade em dias à primeira prenhes houve efeito individual de C na desmama, PeD, GD, P e M no sobreano, GS, GT e IGF-I (p<0,05), no entanto, P e M na desmama não se mostraram importantes (p>0,05). Todas as avaliações de CPM mostraram correlações positivas com o GD, GS ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Lately frame has being used to predict the occurrence of precocious puberty in Nellore heifers. This experiment compared the possible effects of weaning weight (PeD), yearling weight (PeS), rump backfat thickness (EGSG), serum concentrations of IGF-I (IGF-I) and insulin to yearling (INS), daily weight gain until weaning (GD), between weaning to yearling (GS) and from birth to yearling (GT), further the visual scores of conformation (C), precocity (P) and musculature (M) on weaning and yearling, on age at first pregnancy and the performance in the first breeding season (EM) of Nellore heifers. For that, data from 241 animals, produced by P@RM farming, born between May to September 2016 was used. After weaning all heifers were kept on pasture in a single lot and CPM score and body weight gain, under restriction of food and water for 12 h, were evaluated at weaning and repeated after a minimum weight gain of 50 kg. Breeding season started a day after evaluation of yearling, where heifers were subjected to a puberty induction protocol and two fixed time artificial inseminations, followed by a clean-up bull. There was an individual effect of C at weaning, PeD, GD, P and M on the yearling, GS, GT and IGF-I on age at days at first pregnancy (p<0.05), however, the date of birth, P and M at weaning had no significant effect (p>0.05). All CPM evaluations showed positive correlations with GD, GS and GT both at weaning (r= 0.61, 0.38, 0.43, p<0.05) and yearling (0.46, 0.50, 0, 41, p<0.05... (Complete abstract click electronic access below) / Doutor

Tax incentives such as investment tax credit and taxable income deductions related to the environment and climate change are becoming more popular. Introducing tax incentives related to the environment and climate change helps meet the sustainability objectives of growth and development. Many countries worldwide are taking serious steps to counter the mounting challenges due to changing climatic conditions. To meet the sustainability goals, Sweden has set a goal to lower greenhouse gas emissions by 55% in 2030 compared to 1990. In this regard, it is imperative to reflect on the tax incentives provided by the Swedish government in terms of the investment tax credit. It is significant to investigate the beneficiaries of the Swedish government's tax incentives. We selected the top 100 listed companies on the Swedish stock market, Nasdaq Stockholm, to answer this question from 2017 to 2019. Our dependent variable is a dummy indicating 1 for firms who took advantage of the investment tax credit and 0 otherwise. We use ESG scores to construct our dependent variable. Because a higher ESG score reflects a more sustainable approach to production by firms. Therefore, we use dummy 1 for firms on the top of ESG ranking and 0 otherwise. We use different firm-level characteristics as the independent variables, such as age, size, investment, capital, assets, capacity, net capital, and net income. We use a longitudinal research design because sample observations vary across firms and over a short time. We conduct probit and logistic regression to identify the beneficiaries of the tax incentives. The study's findings show that different firm-level characteristics significantly impact the probability of being an ITC beneficiary. For instance, domestic enterprises are more likely to benefit from tax incentives than foreign enterprises, but the relationship is insignificant. In the same way, firms with a maximum number of employees and capital stock are more likely to benefit from the tax incentives than firms with lower capital stocks and limited employees. Our findings also show that firms with higher amounts of new investment in fixed assets are more likely to benefit from the tax incentives. Finally, we found a statistically significant coefficient for firm capacity, an indicator of total inventory. Specifically, the higher the capacity of a firm, the more it is likely to be an ITC beneficiary.

Le Fossé rhénan bénéficie de circulations naturelles d’eau géothermale, ce qui le rend propice à l’exploitation géothermique. Comment et où les fluides géothermaux circulent-ils ? Quels liens ont-ils avec la tectonique et la sismicité induite ? La géodésie spatiale pourrait-elle apporter de nouveaux éclairages à ces questionnements ? L’objectif de cette thèse est la réalisation d’un suivi géodésique des sites géothermiques de Soultz-sous-Forêts et de Rittershoffen (Alsace, France). Les observations permettent de faire un état des lieux des déplacements de surface des environs des sites pendant leur mise en place et apportent de nouvelles connaissances à l’échelle locale sur le Fossé rhénan supérieur. Les résultats majeurs concernent l’analyse des déformations observées à Landau (Rhénanie-Palatinat, Allemagne). Cette approche illustre également les complémentarités des méthodes géodésiques utilisées (InSAR, GNSS, nivellement). / The Upper Rhine Graben benefits of natural circulation of geothermal fluid, which makes it suitable for geothermal exploitation. How and where do geothermal fluids circulate? What are their links with induced seismicity and tectonics? Could geodesy provide new insigth to these questions ? The objective of this thesis is the realization of a geodetic monitoring at Soultz and Rittershoffen (Alsace, France) geothermal sites. The results are an inventory of nearby sites surface displacements during the implementation of the geothermal sites. They bring new knowledge locally on the Upper Rhine Graben. The main results are the analysis of deformations observed in Landau (Palatinat, Germany). This approach also reflects the complementarities of geodetic methods (InSAR, GNSS, levelling).

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Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-09-22T13:27:31Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_InterfaceGraficaProcessamentos.pdf: 1358079 bytes, checksum: 0a46b54cbf6f962cc071bf26f80727b3 (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-09-29T14:18:43Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_InterfaceGraficaProcessamentos.pdf: 1358079 bytes, checksum: 0a46b54cbf6f962cc071bf26f80727b3 (MD5) / Made available in DSpace on 2014-09-29T14:18:43Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_InterfaceGraficaProcessamentos.pdf: 1358079 bytes, checksum: 0a46b54cbf6f962cc071bf26f80727b3 (MD5) Previous issue date: 2001 / O presente trabalho consiste no desenvolvimento de uma interface gráfica para pré e pós-processamentos de dados elétricos e eletromagnéticos em geofísica utilizando-a na transformação da EGSLIB – Electrical Geophysics Software Library, a qual é constituída por um acervo de programas FORTRAN para DOS, em um software integrado e que possua uma eficiente interface gráfica com o usuário. O resultado deste esforço foi a surgimento de um produto que foi denominado EGS 2000 – Electrical Geophysics Suite - 2000 version. Construído em ambiente DELPHI da Borland, através de um processo de desenvolvimento que, além de orientado a objetos, foi centrado em uma arquitetura que permitiu um alto grau de aproveitamento de programas FORTRAN já desenvolvidos e testados. Tal produto, constitui-se em uma poderosa ferramenta de auxílio à modelagem e interpretação de dados geofísicos totalmente executável no sistema operacional MS-Windows. Com isso, alcançou-se uma forma economicamente viável para dar uma destinação prática aos resultados teóricos obtidos nas universidades e institutos de pesquisa. Os exemplos apresentados, mostram-nos que, auxiliadas por computador, modelagens e interpretações de dados geofísicos alcançam um nível de produtividade e versatilidade jamais obtidos pelas ferramentas de outrora, uma vez que diversos modelos podem ser armazenados e recuperados e seus resultados comparados com dados observados sistematicamente colecionados, conferindo ao processo um alto grau de confiabilidade e rapidez.

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In geothermal reservoirs and unconventional gas reservoirs with very low matrix permeability, fractures are the main routes of fluid flow and heat transport, so the fracture permeability change is important. In fact, reservoir development under this circumstance relies on generation and stimulation of a fracture network. This thesis presents numerical simulation of the response of a fractured rock to injection and extraction considering the role of poro-thermoelasticity and joint deformation. Fluid flow and heat transport in the fracture are treated using a finite difference method while the fracture and rock matrix deformation are determined using the displacement discontinuity method (DDM). The fractures response to fluid injection and extraction is affected both by the induced stresses as well as by the initial far-field stress. The latter is accounted for using the non-equilibrium condition, i.e., relaxing the assumption that the rock joints are in equilibrium with the in-situ stress state. The fully coupled DDM simulation has been used to carry out several case studies to model the fracture response under different injection/extractions, in-situ stresses, joint geometries and properties, for both equilibrium and non-equilibrium conditions. The following observations are made: i) Fluid injection increases the pressure causing the joint to open. For non-isothermal injection, cooling increases the fracture aperture drastically by inducing tensile stresses. Higher fracture aperture means higher conductivity. ii) In a single fracture under constant anisotropic in-situ stress (non-equilibrium condition), permanent shear slip is encountered on all fracture segments when the shear strength is overcome by shear stress in response to fluid injection. With cooling operation, the fracture segments in the vicinity of the injection point are opened due to cooling-induced tensile stress and injection pressure, and all the fracture segments experience slip. iii) Fluid pressure in fractures increases in response to compression. The fluid compressibility and joint stiffness play a role. iv) When there are injection and extraction in fractured reservoirs, the cooler fluid flows through the fracture channels from the injection point to extraction well extracting heat from the warmer reservoir matrix. As the matrix cools, the resulting thermal stress increases the fracture apertures and thus increases the fracture conductivity. v) Injection decreases the amount of effective stress due to pressure increase in fracture and matrix near a well. In contrast, extraction increases the amount of effective stress due to pressure drop in fracture and matrix.