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In this work, we study the induced seismicity recorded during an injection operation at the Muara Laboh geothermal plant (Indonesia). The swarm, consisting of three bursts activating a normal fault zone, is characterized by rapid earthquake (km d−1) migration. We use a 2-D rate-and-state asperity model to better understand the physical mechanisms controlling the evolution of this induced swarm. The model suggests that the observed rapid seismic migration can be explained by the interaction among asperities through the expansion of slow post-seismic slip fronts. Also, it shows that the amount of seismicity generated by the fluid injection is strongly controlled by the background seismicity of the system, that is by the seismicity determined by the tectonic load charging the fault. This close correlation between natural and induced seismicity suggests that the injection in Muara Laboh principally stimulates critically stressed faults, which release the seismicity determined by their natural seismic cycle. [ABSTRACT FROM AUTHOR]

This self-reflective study explores how culturally diverse faculty members can benefit from coteaching in higher education classes. It reflects on a teaching collaboration between two researchers-practitioners from different cultural and academic backgrounds in a South African university. The co-teachers shared equal responsibility for a one-month research seminar. The leading argument of this article is that co-teaching within diversity is a key driver for disruptive and productive professional development, as co-teaching exposes faculty members to pedagogical activities and discourses they would not otherwise have experienced. It enables them to move beyond their comfort zone, take risks collectively, and learn reciprocally. The qualitative findings are organised in a model that conceptualises the co-teaching process, unpacking the relationship between empowering trust, emerging complementarities, reciprocal learning, and professional identity affirmation. The model can help teachers reap the benefits of co-teaching in culturally diverse environments. [ABSTRACT FROM AUTHOR]

Job-embedded, collaborative, and reflective professional development programmes have generally been praised internationally for promoting knowledge sharing and meeting the learning needs of extremely busy practitioners, such as university academic and administrative staff. However, in the Southern African context where, for a variety of reasons, professional development draws extensively on traditional pedagogies, their usefulness has not been fully tested. Analysing the experiences of 11 participants of the Programme for University Leadership in the Southern African Region (PULSAR) and subsequent developments within their own institutions, this article shows how Action Learning can be used as a tool for change for university senior administrators. Through this job-embedded, collaborative, and reflective pedagogy, Action Learning provides enabling conditions for university administrators to unlearn, learn and relearn engagement strategies (e.g., questioning and listening skills, participative team-work) to approach workplace problems differently, and in the process, build more effective working relationships. [ABSTRACT FROM AUTHOR]

This paper examines numerical approaches to model operation of gas storage in salt caverns. The emphasis is on taking into account the thermal exchanges between the well, the cavern, and the rock mass, as well as the modelling of the volume losses of the cavern, while keeping the model fast, simple, and operationally usable. The use of this model in the context of monitoring storage operations is illustrated.

Fracturing fluid may jeopardize the production of hydraulically fractured tight gas formations. Because capillary forces act stronger in low-permeability formations, the invaded fracturing fluid is harder to remove. The increase of water saturation around the fractured well affects the mobility of the gas phase, particularly in tight formations where the gas relative permeability declines strongly when water saturation increases. This damage might greatly reduce the gas production in a very long cleanup period. This paper presents numerical simulation techniques to account for formation damage with both a near-well model and a full-field model for fractured wells in tight formations. For the full-field model, the skin determined from an inversion is suitable for long-term production simulations, and a sector model can be used to update the well skin through a coupled modeling so that the full-field model can be used correctly over the whole life of the project. [ABSTRACT FROM AUTHOR]

In this paper, we apply an FEM–BEM coupling method in petroleum engineering to evaluate complex wells (or fractures) performance. We use boundary element methods around wells and fractures, and finite elements in the remaining part of the reservoir. Copyright © 2004 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Discusses control-volume schemes for the modeling of vertical wells using flexible grids in the simulation of oil reservoirs. Proposed numerical schemes based on a logarithmic approach; Goal of improving the linear approach for near-well modeling; Multipoint and a two-point flux approximation scheme; Ability of these schemes to reduce the calculation errors for the dominant singular well flow.

Two patients, treated with acebutolol and amiodarone respectively, developed a disease clinically, radiologically, and pathologically indistinguishable from bronchiolitis obliterans organising pneumonia. In one case recovery followed discontinuation of acebutolol; in the other case cessation of amiodarone had no effect, and corticosteroids were required. In addition to these patients, several cases of bronchiolitis obliterans organising pneumonia have been reported during treatment with gold salts, amiodarone, and miscellaneous other drugs. Taken together, this information supports the view that bronchiolitis obliterans organising pneumonia may be a form of response by the lungs to insult by drugs. [ABSTRACT FROM PUBLISHER]

An experimental characterisation of a low permeability caprock is first reported. Two different methods are compared to measure the porosity: water imbibition and weighting versus gas (Argon) pycnometry. Water measured porosities appear to systematically underestimate gas measured porosities. A capillary pressure curve is derived from successive equilibrium of samples at imposed relative humidities. The relative gas permeability is thoroughly measured on the same samples. Gas porosity and effective gas permeability measurements have been carried out under different confining pressures. All measured relative gas permeabilities lie on a master curve and present a low critical water saturation beyond which the effective gas permeability nearly vanishes. In an attempt to model this last feature, the salient properties of the microstructure are extracted from electron microscopy images to propose a micro-macro model of the relative gas permeability. The multi-scale modeling is performed within the framework of random media or so-called continuum micromechanics, including localised flow effects within interfaces. The self-consistent homogenisation scheme allows retrieval of a critical water saturation, whose value is governed by the shape of the elementary particles of the material and the localisation of water within the pore space.

Abstract Background Adult T cell leukemia results from the malignant transformation of a CD4+ lymphoid clone carrying an integrated HTLV-1 provirus that has undergone several oncogenic events over a 30-60 year period of persistent clonal expansion. Both CD4+ and CD8+ lymphocytes are infected in vivo; their expansion relies on CD4+ cell cycling and on the prevention of CD8+ cell death. Cloned infected CD4+ but not CD8+ T cells from patients without malignancy also add up nuclear and mitotic defects typical of genetic instability related to theexpression of the virus-encoded oncogene tax. HTLV-1 expression is cancer-prone in vitro, but in vivo numerous selection forces act to maintain T cell homeostasis and are possibly involved in clonal selection. Results Here we demonstrate that the HTLV-1 associated CD4+ preleukemic phenotype and the specific patterns of CD4+ and CD8+ clonal expansion are in vivo selected processes. By comparing the effects of recent (1 month) experimental infections performed in vitro and those observed in cloned T cells from patients infected for >6-26 years, we found that in chronically HTLV-1 infected individuals, HTLV-1 positive clones are selected for tax expression. In vivo, infected CD4+ cells are positively selected for cell cycling whereas infected CD8+ cells and uninfected CD4+ cells are negatively selected for the same processes. In contrast, the known HTLV-1-dependent prevention of CD8+ T cell death pertains to both in vivo and in vitro infected cells. Conclusions Therefore, virus-cell interactions alone are not sufficient to initiate early leukemogenesis in vivo.

Tight gas sandstones are low porosity media, with a very small permeability (i.e., below 1 mD). Their porosity is below 10%, and it is mainly composed of fine noncemented microcracks, which are present between neighboring quartz grains. While empirical models of permeability are available, their predictions, which do not compare well with macroscopic measurements, are not reliable to assess gas well productivity. The purpose of this work is to compare the permeability measured on centimetric plugs to predictions based on pore structure data. Two macroscopic measurements are performed, namely dry gas permeability and mercury intrusion porosimetry (MIP), together with a series of local measurements including focused ion beam and scanning electron microscopy (FIB-SEM), x-ray computed microtomography (CMT), and standard two-dimensional (2D) SEM. Numerical modeling is performed by combining analyses on two scales, namely the microcrack network scale (given by 2D SEM) and the individual 3D microcrack scale (given by either FIB-SEM or CMT). The network permeability is calculated by means of techniques developed for fracture networks. This permeability is proportional to the microcrack transmissivity, which is determined by solving the Stokes equation in the microcracks measured by FIB-SEM or CMT. Good correlation with experimental permeability values is only found when using transmissivity from 3D CMT data. [ABSTRACT FROM AUTHOR]