Introducing wwhypda: a world-wide collaborative hydrogeological parameters database

Since the seminal publication of Henry Darcy's work in the 1880s, a very large number of rock property values (such as hydraulic conductivity, permeability, compressibility, porosity, etc.) has been measured and published. These data are, however, dispersed and difficult to access. To overcome this problem and to facilitate site characterization (especially stochastic), a worldwide hydrogeological parameter database (wwhypda) is proposed. It is an open and collaborative catalog allowing users to store and retrieve measurements. The catalog is accessible through a web interface ( http://wwhypda.org ). Presently, it provides individual values and probability density functions of the properties as a function of lithology, scale of observation, location, and geological environmen

High resolution multi-facies realizations of sedimentary reservoir and aquifer analogs

Geological structures are by nature inaccessible to direct observation. This can cause difficulties in applications where a spatially explicit representation of such structures is required, in particular when modelling fluid migration in geological formations. An increasing trend in recent years has been to use analogs to palliate this lack of knowledge, i.e., exploiting the spatial information from sites where the geology is accessible (outcrops, quarry sites) and transferring the observed properties to a study site deemed geologically similar. While this approach is appealing, it is difficult to put in place because of the lack of access to well-documented analog data. In this paper we present comprehensive analog data sets which characterize sedimentary structures from important groundwater hosting formations in Germany and Brazil. Multiple 2-D outcrop faces are described in terms of hydraulic, thermal and chemical properties and interpolated in 3-D using stochastic techniques. These unique data sets can be used by the wider community to implement analog approaches for characterizing reservoir and aquifer formations

Analog-based meandering channel simulation

Characterizing the complex geometries and the heterogeneity of the deposits in meandering river systems is a long-standing issue for the 3-D modeling of alluvial formations. Such deposits are important sources of accessible groundwater in alluvial aquifers throughout the world and also play a major role as hydrocarbons reservoirs. In this paper, we present a method to generate meandering river centerlines that are stochastic, geologically realistic, connected, and conditioned to local observations or global geomorphological characteristics. The method is based on fast 1-D multiple-point statistics in a transformed curvilinear domain: the succession in directions observed in a real-world meandering river (the analog) is considered as statistical model for multiple-point statistics simulation. The integration of local data is accomplished by an inverse procedure ensuring that the channels pass through a given set of locations while conserving the high-order spatial characteristics of an analog. The methodology is applied on seven real-world case studies. This work demonstrates the flexibility and the applicability of multiplepoint statistics outside the standard paradigm that considers the simulation of a 2-D or 3-D variable with spatial coordinates

Experimentation of a Web Database for Augmented Reality Apps. The case study of ruled geometries

The growing field of Augmented Reality Apps is an indication of greater interest, by private markets and public institutions, towards immersive visualization and those tools that can enhance cultural content through user involvement. An often underrated feature of this digitalization lies in the smart language with which the notions are shown, in quick synthesis based on schemes, slides, lists, images, and comparisons. But the continuous input of data in an app can cause various problems, both on the hardware and software front: from the obvious weight gain, not negligible for pocket devices, to the continuous updating of scientific knowledge, that risks leaving behind all those theoretical contents that are not controlled or renewed. To this is added the problem of the constant maintenance of mobile devices for what concerns software, operating systems, security protocols, and systems for decoding existing data, especially for AR Apps that use audio and video devices. With this in mind, and in order to optimize the performance of mobile tools, a digital archive in the form of an open-source site is useful, providing centralized and pre-cataloged data specifically for use in the AR App. In this way, qualified users can contribute to the knowledge presented through a client-server upload system on the site, properly filtered by semi-automatic security checks. The experimentation of the contribution investigates the advantages and possibilities of such a structured system, setting the case study on the theory of ruled geometries, and the architectures corresponding to them

Locality-based 3-D multiple-point statistics reconstruction using 2-D geological cross-sections

Multiple-point statistics (MPS) has shown promise in representing complicated subsurface structures. For a practical three-dimensional (3-D) application, however, one of the critical issues the difficulty to obtain a credible 3-D training image. However, bidimensional (2-D) training images are often available because established workflows exist to derive 2-D sections from scattered boreholes and/or other samples. In this work, we propose a locality-based MPS approach to reconstruct 3-D geological models on the basis of such 2-D cross-sections, making 3-D training images unnecessary. Only several local training sub-sections closer to the central uninformed node are used in the MPS simulation. The main advantages of this partitioned search strategy are the high computational efficiency and a relaxation of the stationarity assumption. We embed this strategy into a standard MPS framework. Two probability aggregation formulas and their combinations are used to assemble the probability density functions (pdfs) from different sub-sections. Moreover, a novel strategy is adopted to capture more stable pdfs, where the distances between patterns and flexible neighborhoods are integrated on several multiple grids. A series of sensitivity analyses demonstrate the stability of the proposed approach. Several hydrogeological 3-D application examples illustrate the applicability of our approach in reproducing complex geological features. The results, in comparison with previous MPS methods, show better performance in portraying anisotropy characteristics and in CPU cost

Incremental Peritoneal Dialysis Favourably Compares with Hemodialysis as a Bridge to Renal Transplantation

Background. The value of incremental peritoneal dialysis (PD) as a bridge to renal transplantation (Tx) has not been specifically addressed. Methods. All consecutive Stage 5 CKD patients with at least 1 year predialysis followup, starting incremental PD or HD under our care and subsequently receiving their first renal Tx were included in this observational cohort study. Age, gender, BMI, underlying nephropathy, residual renal function (RRF) loss rate before dialysis and RRF at RRT start, comorbidity, RRT schedules and adequacy measures, dialysis-related morbidity, Tx waiting time, RRF at Tx, incidence of delayed graft function (DGF), in-hospital stay for Tx, serum creatinine at discharge and one year later were collected and compared between patients on incremental PD or HD before Tx. Results. Seventeen patients on incremental PD and 24 on HD received their first renal Tx during the study period. Age, underlying nephropathy, RRF loss rate in predialysis, RRF at the start of RRT and comorbidity did not differ significantly. While on dialysis, patients on PD had significantly lower epoetin requirements, serum phosphate, calciumxphosphate product and better RRF preservation. Delayed graft function (DGF) occurred in 12 patients (29%), 1 on incremental PD and 11 on HD. Serum creatinine at discharge and 1 year later was significantly higher in patients who had been on HD. Conclusions. In patients receiving their first renal Tx, previous incremental PD was associated with low morbidity, excellent preservation of RRF, easier attainment of adequacy targets and significantly better immediate and 1-year graft function than those observed in otherwise well-matched patients previously treated with HD

Il Motel Agip di Mario Ridolfi. Dall’analisi grafica alla rappresentazione parametrica e immersiva

The research aims to describe the process of generation and growth of the architectural form of an unrealized project by Mario Ridolfi, the Agip Motel in Settebagni, through the aid of graphic analysis, geometric and parametric modeling and virtual reality . Versatile architect, with a vast production, well documented by the sources, of completed and unrealized projects, the latter little studied, especially from the point of view of geometry. The abundant presence of design documentation has made it possible to identify and reconstruct the geometric layout on which the motel tower is based: a decagonal matrix plan with star-shaped vertices, in a progression of floors defined by a cylindrical helix. This polycentric trend of the elevation is manifested in a torsion of the building, and in a continuous irregularity of the internal plans, which therefore requires the project a considerable commitment to adapt. Starting from the graphic reconstruction, a 3D model of the plan and a parametric script of the envelope were created, which controls the various functions of the torsion and the different perimeters. Finally, at the end of the restitution, it was decided to reproduce the discrete parametric model in an augmented reality system, with an interactive mechanism for scrolling through the planes of the model and effectively visualizing the evolution of the heights