Analytical review of passive mass transfer of water vapor in a space suit

Engineering study and analysis of water vapor mass transfer in space sui

Dynamic Supply Chain Network Design for Diesel Fuel Consumption in Oil and Gas Fields

A dynamic supply chain network (SCN) design problem is addressed in this work to optimally fulfill diesel fuel demands in oil and gas fields. Through a novel mixed integer linear programming (MILP) formulation we seek to determine the location of a group of storage tanks (ST) aiming to fulfill the diesel fuel demand while minimizing the net present value of the overall costs over the planning horizon. We introduce the concept of by the mobile ST, which can be seized of released at any period during the planning horizon. Mo-bile STs can be moved period by period among the grid of potential nodes of the superstructure. An integrated SCN is considered, taking into account all its dis-tinctive characteristics. In fact, a generalized approach is developed allowing for flexible flows across the network, capturing the intertwined nature of deci-sions. Economies of scale governing capital investments and operational costs are reflected in terms of the different types of ST to be optimally selected by the model. Lastly, the service level is assessed through a hybrid indicator composed of the magnitude of the flows and the total time required to fulfill fuel demands. A case study under different scenarios is addressed to show the potentials of the proposed approach and the efficiency of the SCN designs being obtained.Sociedad Argentina de Informática e Investigación Operativ

Dynamic Supply Chain Network Design for Diesel Fuel Consumption in Oil and Gas Fields

A dynamic supply chain network (SCN) design problem is addressed in this work to optimally fulfill diesel fuel demands in oil and gas fields. Through a novel mixed integer linear programming (MILP) formulation we seek to determine the location of a group of storage tanks (ST) aiming to fulfill the diesel fuel demand while minimizing the net present value of the overall costs over the planning horizon. We introduce the concept of by the mobile ST, which can be seized of released at any period during the planning horizon. Mo-bile STs can be moved period by period among the grid of potential nodes of the superstructure. An integrated SCN is considered, taking into account all its dis-tinctive characteristics. In fact, a generalized approach is developed allowing for flexible flows across the network, capturing the intertwined nature of deci-sions. Economies of scale governing capital investments and operational costs are reflected in terms of the different types of ST to be optimally selected by the model. Lastly, the service level is assessed through a hybrid indicator composed of the magnitude of the flows and the total time required to fulfill fuel demands. A case study under different scenarios is addressed to show the potentials of the proposed approach and the efficiency of the SCN designs being obtained.Sociedad Argentina de Informática e Investigación Operativ

Dynamic Supply Chain Network Design for Diesel Fuel Consumption in Oil and Gas Fields

A dynamic supply chain network (SCN) design problem is addressed in this work to optimally fulfill diesel fuel demands in oil and gas fields. Through a novel mixed integer linear programming (MILP) formulation we seek to determine the location of a group of storage tanks (ST) aiming to fulfill the diesel fuel demand while minimizing the net present value of the overall costs over the planning horizon. We introduce the concept of by the mobile ST, which can be seized of released at any period during the planning horizon. Mo-bile STs can be moved period by period among the grid of potential nodes of the superstructure. An integrated SCN is considered, taking into account all its dis-tinctive characteristics. In fact, a generalized approach is developed allowing for flexible flows across the network, capturing the intertwined nature of deci-sions. Economies of scale governing capital investments and operational costs are reflected in terms of the different types of ST to be optimally selected by the model. Lastly, the service level is assessed through a hybrid indicator composed of the magnitude of the flows and the total time required to fulfill fuel demands. A case study under different scenarios is addressed to show the potentials of the proposed approach and the efficiency of the SCN designs being obtained.Sociedad Argentina de Informática e Investigación Operativ

Analysis of the micro to macro response of clays to compression

An investigation of clay microstructure and its evolution under 1D and isotropic compression is presented for different clays. Data from the literature are compared to original results on two Italian clays, obtained using SEM, image processing, MIP and on-purpose swelling tests. The effects of composition and loading history on clay microstructure, as well as its changes along the compression path (pre- and post-gross-yielding) are analysed and a conceptual model of microstructure evolution is proposed for the clays under study. NC clays at early virgin compression, either natural or reconstituted, are found to possess an open fabric of random-low orientation, complying with a prevailing inter-aggregate and a smaller intra-aggregate porosity, whose size and distribution depend on composition. Under 1D compression, either in the field or in the laboratory, the inter-aggregate porosity is lost, at a rate dependent on composition and loading history, and the dominant intra-aggregate micro-pore is progressively reduced. Accordingly, perfectly oriented stacks of domains are recognised which, though, embed preserved random particle arrangements even at large pressures, resulting in an increase of average orientation up to the reach of a steady orientation degree. Isotropic compression causes faster microstructure evolution, although large pressures are required to change 1D-induced fabric orientation.Peer ReviewedPostprint (author's final draft

Characterisation of the multi-scale fabric features of high plasticity clays

An investigation of the microstructural features of a high-plasticity clay, in both its natural conditions and reconstituted in the laboratory, is described. Scanning electron microscopy is used here to characterise the fabric at different magnifications, while image processing of the micrographs delivers a quantitative assessment of the fabric orientation. The results of energy-dispersive X-ray spectroscopy and swelling tests, as reported in a previous study by the authors, are used to characterise the bonding nature and strength, as well as mercury intrusion porosimetry to investigate clay porosimetry. Despite their identical composition, the natural and the reconstituted clay have experienced different deposition and loading history, generating different microstructural features that are shown to underlie their differences in state. For both clays, one-dimensional (1D) compression to medium–high pressures is seen to determine a well-oriented medium magnification fabric. However, larger-scale observations and the corresponding image processing results reveal non-uniform local fabric features, hence making fabric characterisation dependent on the scale of analysis and bringing about the issue of identifying the clay micro-scale representative element volume relating to the clay macro-behaviour. The micro-REV is identified for the clays under study and its connection with the macro-behaviour characterised. The microstructural evolution induced by 1D compression to very high pressures is shown to concern mainly the clay porosity and porosimetry, the fabric orientation being steady, thus explaining the isotropic hardening observed in laboratory tests.Peer ReviewedPostprint (author's final draft

Can the current state support mechanisms help the growth of renewable energies in wind markets?

The aim of this paper is to provide evidence on the effectiveness of the current state support mechanism incentive adopted by the Italian government in the wind market. In particular, this paper intends to investigate the effectiveness of the auction mechanism as an incentive tool for renewable sources as required by the transposition of Directive 2009/28/EC. In order to demonstrate the economic and financial feasibility of a typical wind-sector investment, we performed a scenario analysis (Monte Carlo simulation) determining a 52,500 Net Present Value (NPV) by varying the key underlying variables of the investment. The results show that with the mechanism currently in place the percentage of positive leveraged NPV is approximately equal to 70%. Despite the state contribution provided through the “Feed-in tariff” mechanism, the profitability of wind projects is not always successful, and this problem could be amplified by the slowness of the authorization procedures. The article offers prime reflections for scholars and policy makers who have long been committed to promoting sustainable development and important considerations on the introduction of further incentive models

Complexity Characterization in a Probabilistic Approach to Dynamical Systems Through Information Geometry and Inductive Inference

Information geometric techniques and inductive inference methods hold great promise for solving computational problems of interest in classical and quantum physics, especially with regard to complexity characterization of dynamical systems in terms of their probabilistic description on curved statistical manifolds. In this article, we investigate the possibility of describing the macroscopic behavior of complex systems in terms of the underlying statistical structure of their microscopic degrees of freedom by use of statistical inductive inference and information geometry. We review the Maximum Relative Entropy (MrE) formalism and the theoretical structure of the information geometrodynamical approach to chaos (IGAC) on statistical manifolds. Special focus is devoted to the description of the roles played by the sectional curvature, the Jacobi field intensity and the information geometrodynamical entropy (IGE). These quantities serve as powerful information geometric complexity measures of information-constrained dynamics associated with arbitrary chaotic and regular systems defined on the statistical manifold. Finally, the application of such information geometric techniques to several theoretical models are presented.Comment: 29 page