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In this study, the performance evaluation of different optimization methods in calculating the change of camera movement, in other words the camera position and angle, was made on images taken from different views with the same camera. For this purpose, gradient-based and population-based optimization techniques have been investigated by using the differentiable rendering methods that have been proposed in recent years for the 3D point cloud created over depth information. It was found that while gradient-based methods are more successful on close movements, population-based methods were more successful in distant changes.

Forest degradation is a gradual process through which the forest's biomass declines, the species composition and vertical complexity change and the soil physicochemical properties degrade. Evaluating forest degradation is challenging, as it needs measurable indicators in order to compare different states of degraded forest with forests in optimal conditions. The UAV-SfM technique, combining imagery taken from unpiloted aerial vehicles (UAV) and Structure from Motion (SfM) algorithms, offers the opportunity to model forests in three dimensions and to derive ecological indicators describing forest conditions. The research objective of this paper is to evaluate to what extent information on forest degradation can be derived with UAV-SfM techniques. The Dry Chaco ecosystem in Argentina offers us the possibility to study the effects of a long history of anthropogenic disturbances on subtropical broadleaf dry forests. We surveyed a sample of 54 forest plots with different degradation histories with a UAV. Based on existing literature on forest ecology, two main degradation mechanisms were defined: loss of vertical integrity and vertical complexity. Multivariate statistical techniques were applied on structural indicators extracted from the 3D canopy model to classify the forest plots into groups or clusters with similar forest conditions. Next, the structural characteristics of the clusters were discussed in the light of a conceptual framework on forest degradation in the Dry Chaco. The results show that objective criteria derived from UAV-SfM 3D canopy models can be used to differentiate (1) forests in good condition from (2) forests that were subject to extensive processes of degradation, (3) forest with a dominance of shrubs and low trees, (4) forests intensively disturbed and (5) low vegetation dominated by bare soils with shrubs. © 2022 Elsevier B.V.

Interactive motion planing and collaborative positioning will play a key role in future autonomous driving applications. For this purpose, the precise reconstruction and pose estimation of other traffic participants, especially of other vehicles, is a fundamental task and will be tackled in this paper based on street level stereo images obtained from a moving vehicle. We learn a shape prior, consisting of vehicle geometry and appearance features, and we fit a vehicle model to initially detected vehicles. This is achieved by minimising an energy function, jointly incorporating 3D and 2D information to infer the model’s optimal and precise pose parameters. For evaluation we use the object detection and orientation benchmark of the KITTI dataset (Geiger et al., 2012). We can show a significant benefit of each of the individual energy terms of the overall objective function. We achieve good results with up to 94.8% correct and precise pose estimations with an average absolute error smaller than 3° for the orientation and 33 cm for position.

Many bridges around the world are in urgent need of refurbishment and face challenges of limited capital investment and condition assessment. Public transportation agencies need reliable monitoring technologies to provide advance warnings of performance loss and pending failure of their critical assets, probability of which may increase due to climate change and extreme weather events. Satellites can be used to address some of these issues by taking several images of a bridge structure at different times and analyzing them with advanced processing techniques such as Interferometric Synthetic Aperture Radar (InSAR). With this approach, accurate weather-independent displacement measurements can be obtained to complement scheduled visual inspection data for bridge performance assessment. This paper presents the InSAR methodology with application to a major bridge in Montreal, Canada, namely the historic Victoria Bridge over which acquired satellite images have been validated against analytical and numerical predictions. A new calculation methodology is presented for the validation of satellite displacement measurements and their comparison to predefined thresholds in order to identify the extent and location of excessive motion on the bridge structure. The displacement results of interest include linear rate (or velocity) and thermal sensitivity (or thermal expansion rate), where both, taken separately or in combination, are found valuable for an accurate assessment of the bridge structural integrity. Finally, a new software platform called BRIGITAL is presented, which can make use of satellite data for 3D visualization, data analysis, and detection and early warning of excessive bridge displacements, which can help bridge engineers identify hot spots on bridges and take action to avoid possible problems and failures., 10th International Conference on Structural Health Monitoring of Intelligent Infrastructure, SHMII 2021, June 30 - July 2, 2021, Porto, Portugal

To visualize any new entity, a visualization algorithm should be designed and programmed. Investigating approaches for programming new scientific visualizations, we come with the following technique: utilize CinemaScience format to describe 3D scenes. CinemaScience is developed for storing and visualizing supercomputer and physical modelling results, and differs with simplicity both for human and machine. It has a set of interesting features, for example it allows to specify dynamics in views dependent on parameters. However, the technique currently known applications are 2D graphics, and in this paper we extend it for 3D case. The main feature of the approach is treating of Cinema artifacts as visual objects of explicit type. We successfully used the suggested approach in various visualization tasks, examples are presented in the paper. We developed the open-source web application that implements the suggested approach. It is open-source and its main features are also described in the paper. © 2021 National Research Nuclear University. All rights reserved.

International audience; At present, network analysis based on the graph theory has become a widely used technique in the field of Mental Health. The networks are part of the main structure of BeGraph software, a 3D visualization cloud application that allows the analysis of complex networks. The main objective of this study is to analyze, through the BeGraph software, the behavior of Mental Health prevalent diseases in a region of Spain, in order to make health decisions. The study used a database with a total of 9403 patient’s records with Mental Health diseases, which belong to two hospitals in Castilla and Leon, Spain, and the 3D visualization software, BeGraph. The results obtained allow us to determine the main diseases detected in each hospital included in the study 6.5% of admissions from the University Clinic of Valladolid with unspecified paranoid schizophrenia and 8.84% of admissions from Rio Hortega Hospital with dysthymic disorder. The analysis of the data allows us to focus on the Mental Health main pathologies detected in the hospitals evaluated, and propose prediction algorithms that help in their diagnosis and treatment. © 2021, Springer Nature Singapore Pte Ltd.

Self-driving cars and robots that run autonomously over long periods of time need high-precision and up-to-date models of the changing environment. The main challenge for creating long term maps of dynamic environments is to identify changes and adapt the map continuously. Changes can occur abruptly, gradually, or even periodically. In this work, we investigate how dense mapping data of several epochs can be used to identify the temporal behavior of the environment. This approach anticipates possible future scenarios where a large fleet of vehicles is equipped with sensors which continuously capture the environment. This data is then being sent to a cloud based infrastructure, which aligns all datasets geometrically and subsequently runs scene analysis on it, among these being the analysis for temporal changes of the environment. Our experiments are based on a LiDAR mobile mapping dataset which consists of 150 scan strips (a total of about 1 billion points), which were obtained in multiple epochs. Parts of the scene are covered by up to 28 scan strips. The time difference between the first and last epoch is about one year. In order to process the data, the scan strips are aligned using an overall bundle adjustment, which estimates the surface (about one billion surface element unknowns) as well as 270,000 unknowns for the adjustment of the exterior orientation parameters. After this, the surface misalignment is usually below one centimeter. In the next step, we perform a segmentation of the point clouds using a region growing algorithm. The segmented objects and the aligned data are then used to compute an occupancy grid which is filled by tracing each individual LiDAR ray from the scan head to every point of a segment. As a result, we can assess the behavior of each segment in the scene and remove voxels from temporal objects from the global occupancy grid.

Scanning electron microscopes (SEMs) are versatile imaging devices for the micro- and nanoscale that find application in various disciplines such as the characterization of biological, mineral or mechanical specimen. Even though the specimen&rsquo, s two-dimensional (2D) properties are provided by the acquired images, detailed morphological characterizations require knowledge about the three-dimensional (3D) surface structure. To overcome this limitation, a reconstruction routine is presented that allows the quantitative depth reconstruction from SEM image sequences. Based on the SEM&rsquo, s imaging properties that can be well described by an affine camera, the proposed algorithms rely on the use of affine epipolar geometry, self-calibration via factorization and triangulation from dense correspondences. To yield the highest robustness and accuracy, different sub-models of the affine camera are applied to the SEM images and the obtained results are directly compared to confocal laser scanning microscope (CLSM) measurements to identify the ideal parametrization and underlying algorithms. To solve the rectification problem for stereo-pair images of an affine camera so that dense matching algorithms can be applied, existing approaches are adapted and extended to further enhance the yielded results. The evaluations of this study allow to specify the applicability of the affine camera models to SEM images and what accuracies can be expected for reconstruction routines based on self-calibration and dense matching algorithms.

Temperature-dependent clay mineral assemblages, vitrinite reflectance, and one-dimensional (1-D) thermal and three-dimensional (3-D) geological modeling of a Neogene wedge-top basin in the Sicilian fold-and-thrust belt and its pre-orogenic substratum allowed us to: (1) define the burial history of the sedimentary succession filling the wedge-top basin and its substratum, (2) reconstruct the wedge-top basin geometry, depocenter migration, and sediment provenance through time in the framework of a source-to-sink system, and (3) shed new light into the kinematic evolution of the Apennine-Maghrebian fold-and-thrust belt.The pre-orogenic substratum of the Scillato basin shows an increase in levels of thermal maturity as a function of stratigraphic age that is consistent with maximum burial to 3.5 km in deep diagenetic conditions. In detail, Ro% values range from 0.40% to 0.94%, and random ordered illite-smectite (I-S) first converts to short-range ordered structures and then evolves to long-range ordered structures at the base of the Imerese unit. The wedge-top basin fill experienced shallow burial (∼2 km) and levels of thermal maturity in the immature stage of hydrocarbon generation and early diagenesis. Vitrinite reflectance and mixed-layer I-S values show two populations of authigenic and inherited phases. The indigenous population corresponds to macerals with Ro% values of 0.33%–0.45% and I-S with no preferred sequence in stacking of layers, whereas the reworked group corresponds to macerals with Ro% values of 0.42%–0.47% and short-range ordered I-S with no correlation as a function of depth.Authigenic and reworked components of the Scillato basin fill allowed us to unravel sediment provenance during the Neogene, identifying two main source areas feeding the wedge-top basin (crystalline units of the European domain and sedimentary units of the African domain), and to detect an early phase of exhumation driven by low-angle extensional faults that predated Neogene compression.

Carbon sequestration in geological formations is in demand for many applications, especially energy production from hydrates. During gas production in a sandy hydrate reservoir, two phase flow and changes in confinement takes place. Nine fully saturated sand systems were scanned three times; before, during and after CO2 gas injection. The confinement pressure was altered, by placing a vertical spring that presses against the upper port of the sediment cylinder. 3D images were analyzed by direct visualization, followed by quantification and pore network analysis. Outcomes demonstrated that shape of sand particles affects how the unconsolidated media will impact the flow, in angular sediments with high confinement pressure, there is more friction between the grains, this results in no dislocations of sand, the fines clog the throats, and more formation damage is noted. In rounded grains with lower confinement pressure, sand grains dislocated; opening large pathways for gas flow; this resulted in lower formation damage. Measures done using pore networks, showed that because of micro-fractures, permeability of the system can increase during hydrate production. This is in contrast to the other systems, where throat sizes shrunk, decreasing the permeability; because of fines migration toward the throats and the small sand grains dislocations. EAGE 2019. This research was made possible by the National Priorities Research Program (NPRP) grant #NPRP8-594-2-244 from Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the authors. The SMT images were collected using the X-ray Operations and Research Beamline Station 13-BMD at Argonne Photon Source (APS), Argonne National Laboratory. The authors thank Dr. Mark Rivers of APS for help in performing the SMT scans. They also acknowledge the support of GeoSoilEnviroCARS (Sector 13), which is supported by the National Science Foundation, USA, Earth Sciences (EAR-1128799), and the US Department of Energy (DOE), Geosciences (DE-FG02-94ER14466). Use of the Advanced Photon Source, an Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory, was supported by DOE, USA under contract no. DE-AC02-06CH11357. Scopus

In this paper a suitable methodology for the improvement of the reliability of results in classification systems based on 3D images is proposed. More in detail, it is based on the knowledge of the uncertainty of the features constituting the 3D image (obtained processing a pair of two 2D stereoscopic images) and on a suitable statistical approach providing a confidence level to the classification result. These pieces of information are then managed in order to improve the classification performance in terms of correct classification and false reject percentages. The experimental results, obtained applying the methodology on an Active Appearance Models algorithm for feature detection and triangulating the 3D features, show that, compared with a basic approach (which generally does not take into account the uncertainty on 3D features), the proposed methodology allows to significantly improve the classification performance even in scenarios characterized by a high uncertainty.

The geometric and hemodynamic characteristics of the left and right vertebral arteries (LVA, RVA) of six healthy volunteers were investigated for the supine (S) and the prone position (P) a common sleeping posture with head rotation. MRI images were used to reconstruct the subject specific three-dimensional solid models of the LVA and RVA from the level of the carotid bifurcation to the vertebrobasilar junction (VJ). Geometric parameters such as cross sectional area ratio, curvature, tortuosity and branch angle were estimated. MR-PCA was used to obtain the blood flow waveforms for the two positions and computational fluid dynamics (CFD) were used to assess the flow field in terms of wall shear stress (WSS) relative residence times (RRT) and localized normalized helicity (LNH). Significant geometric changes but moderate flow changes were observed for both vertebral arteries with head rotation. The CFD results at the VJ show that head rotation causes changes in the WSS distribution, RRT and LNH. Further studies are warranted to assess the clinical significance of the results in terms of atherosclerosis development at the VJ and how the observed geometric changes may affect blood flow to the brain in healthy subjects and vertebral artery stenosis patients, and in terms of increased rapture susceptibility in vertebrobasilar aneurysm patients. © 2015, Biomedical Engineering Society. 43 6 1287 1297 Cited By :4

cited By 2; International audience; Recently, the concept of X-ray diffraction contrast tomography (DCT) has been extended to the case of more widely available laboratory source CT systems. Using well known concepts from geometrical ray optics, an exact formulation is derived for the forward and backward projection geometry encountered under polychromatic cone beam illumination, and it is shown how this projection model can be efficiently implemented in practice. The new projection model is subsequently used for iterative tomographic reconstruction of the three-dimensional shape of a grain from a set of experimentally observed cone beam projections and shows a clear improvement compared to the simplified projection model used previously. © 2015 International Union of Crystallography.

The School of Creative Arts & Technologies at Ulster University (Magee) has brought together the subject of computing with creative technologies, cinematic arts (film), drama, dance, music and design in terms of research and education. We propose here the development of a flagship computer software platform, SceneMaker, acting as a digital laboratory workbench for integrating and experimenting with the computer processing of new theories and methods in these multidisciplinary fields. We discuss the architecture of SceneMaker and relevant technologies for processing within its component modules. SceneMaker will enable the automated production of multimodal animated scenes from film and drama scripts or screenplays. SceneMaker will highlight affective or emotional content in digital storytelling with particular focus on character body posture, facial expressions, speech, non-speech audio, scene composition, timing, lighting, music and cinematography. Applications of SceneMaker include automated simulation of productions and education and training of actors, screenwriters and directors. © ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2017.

3D virtual reconstruction of human body parts is nowadays a common practice in many research fields such as the medical one, the manufacturing of customized products or the creation of personal avatar for gaming purpose. The acquisition can be performed with the use of an active stereo system (i.e., laser scanner, structured light sensors) or with the use of a passive image-based approach. While the former represents a consolidated approach in human modeling, the second is still an active research field. Usually, the reconstruction of a body part through a scanning system is expensive and requests to project light on the patient’s body. On the other hand, the image-based approach could use multi-photo technique to reconstruct a real scene and provides some advantages: low equipment costs (only one camera) and rapid acquisition process of the photo set. In this work, the use of the photogrammetry approach for the reconstruction of humans’ face has been investigated as an alternative to active scanning systems. Two different photogrammetric approaches have been tested to verify their potentiality and their sensitivity to configuration parameters. An initial comparison among them has been performed, considering the overall number of points detected (sparse point cloud reconstruction, dense point cloud reconstruction). Besides, to evaluate the accuracy of the reconstruction, a set of measures used in the design of wearable head-related products has been assessed.

This contribution highlights the potential that modern technologies offer for virtual reconstruction and immersive navigation of monuments that are unavailable due to catastrophic events or other causes. A methodology is proposed for the enjoyment of the Cultural Heritage, starting from modeling, three-dimensional and photorealistic, to arrive at visualization in a virtual world enriched with extra content.

This paper presents the integral equations of the direct problem of magnetic prospecting with respect to demagnetization. These equations are derived for a two-layer medium model. The method of determining the intensity of a secondary magnetic field for the case of magnetizing by a static field, which potential is a harmonic function, is described. The respective integral equations are written based on the theory of a simple layer potential. An iteration algorithm for solving the three-dimensional structural inverse problem of magnetic prospecting with respect to demagnetization for the sampled medium model is proposed based on the modified method of local corrections. For the method of local corrections, it is important to suggest that a change in the model field is mostly influenced by a change in the geometry of part of the object’s boundary that is the nearest to the point of observation. The main feature of this algorithm allows us to get effective technique for solution of magnetic inverse problem for medium with any numbers of layers. © SGEM 2017. All Rights Reserved.

We propose a method for computing realistic computer-generated holograms (CGHs) of three-dimensional (3D) objects, where we benefit from well-established graphical processing units (GPUs) and computer graphics techniques to handle occlusion, shading and parallax effects. The graphics render provides a 2D perspective image including occlusion and shading effects. We also extract the depth map data of the scene. The intensity values and 3D positions of object points are extracted by combining the rendered intensity image and the depth map (Z-buffer) image. We divide the depth range into several planes and quantize the depth value of 3D image points to the nearest plane. In the CGH computation part, we perform proper Fresnel transformations of these planar objects and sum them up to create the hologram corresponding to the particular viewpoint. We then repeat the entire procedure for all possible viewpoints and cover the hologram area. The experimental results show that the technique is capable of performing high quality reconstructions in a fast manner., European Research Council under the European Union Seventh Framework Programme (FP7) ERC

This paper presents a comprehensive experimental study and detailed mechanistic interpretations of the tensile behavior of one representative 3D non-crimp orthogonal woven (3DNCOW) carbon/epoxy composite. The composite is tested under uniaxial in-plane tensile loading in the warp, fill and +/- 45 degrees bias directions. An "S-shape" nonlinearity observed in the stress-strain curves is explained by the concurrent contributions of inherent carbon fiber stiffening ("non-Hookean behavior"), fiber straightening, and gradual damage accumulation. Several approaches to the determination of a single-value Young's modulus from a significantly nonlinear stress-strain curve are discussed and the best approach recommended. Also, issues related to the experimental determination of effective Poisson's ratios for this class of composites are discussed, and their possible resolution suggested. The observed experimental values of the warp- and fill-directional tensile strengths are much higher than those typically obtained for 3D interlock weave carbon/epoxy composites while the nonlinear material behavior observed for the +/- 45 degrees-directional tensile loading is in a qualitative agreement with the earlier results for other textile composites. Results of the damage initiation and progression, monitoried by means of acoustic emission, full-field strain optical measurements, X-rays and optical microscopy, are illustrated and discussed in detail. The damage modes at different stages of the increasing tensile loading are analyzed, and the principal progressive damage mechanisms identified, including the characteristic crack patterns developed at each damage stage. It is concluded that significant damage initiation of the present material occurs in the same strain range as in traditional cross-ply laminates, while respective strain range for other previously studied carbon/epoxy textile composites is significantly lower. Overall the revealed advantages in stiffness, strength and progressive damage behavior of the studied composite are mainly attributed to the absence of crimp and only minimal fiber waviness in the reinforcing 3DNCOW preform. K.U. Leuven

X-ray photoelectron spectroscopy (XPS) has been used to explore the cation rearrangement between the surface and bulk of grains and the surface chemical states of Ce, Mn, Co, Sr, and O ions in the single phase CeO 2 -based solid solutions and in the two phase (100 − x )La 0.6 Sr 0.4 CoO 3 – x CeO 2 (LSCC x ) and (100 − x )La 0.8 Sr 0.2 MnO 3 – x CeO 2 (LSMC x ) composites. The well-resolved Ce 3 d 5/2 and Ce 3 d 3/2 spin–orbit components were determined to study the Ce 4+ to Ce 3+ electronic transition at the surface. The surface of the LSCC x and LSMC x ( x = 8–40 mol%) composites is depleted in cerium. Both Ce 4+ and Ce 3+ cations were revealed. The surface fraction of Ce 4+ cations increases with the rise in CeO 2 content in both systems, but it is higher by about a factor of two in the LSCC composites. A strong enrichment of the surface by Co cations was observed for the composites LSCC x ( x = 8–40 mol%), implying that the presence of cerium could facilitate the Co surface segregation. A slight Sr surface enrichment compared to the nominal stoichiometry was found for La 0.6 Sr 0.4 CoO 3 , CeO 2 -based solid solutions, LSCC57, and LSMC x ( x = 10–57) composites. In contrast, the surface of the LSCC x ( x = 10–37) composites is slightly depleted in strontium cations. The O 1 s spectra of the LSCC and LSMC composites contain several contributions associated with the lattice oxygen related to the phases with the perovskite and fluorite structures as well as with different surface states. Their contributions vary with CeO 2 content and a chemical origin of the transition metal cations on the B-site in the perovskite structure. The Ce 2 (CO 3 ) 3 -based phase seems to exist at the surface of grains and crystallites in the LSCC57 and LSCM composites.

In the article methodology of FEM stimulation of thermal effects, caused by neck-region neuro-electrostimulation was shown. Algorithm of the voxel model conversion to the 3-D objects represented as the complex of the STL-files was described. The evaluation of the temperature in the biological tissues is based on the association of the partial thermal changes, caused by the harmonics components of the pulsed neuro-electrostimulation signal. Features of the thermal changes in the neck region were considered for the neuro-electrostimulation by means of the current pulse field formed in the "SYMPATHOCOR-01" device. Results have shown that for modulation frequencies in range 45-55 Hz, duration of the partial pulses 25-30 us, current pulse amplitude less than 13 mA, the neuro-electrostimulation does not cause thermal changes higher than 0.1 K. Copyright © 2017 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved.

The detection and pose estimation of vehicles plays an important role for automated and autonomous moving objects e.g. in autonomous driving environments. We tackle that problem on the basis of street level stereo images, obtained from a moving vehicle. Processing every stereo pair individually, our approach is divided into two subsequent steps: the vehicle detection and the modelling step. For the detection, we make use of the 3D stereo information and incorporate geometric assumptions on vehicle inherent properties in a firstly applied generic 3D object detection. By combining our generic detection approach with a state of the art vehicle detector, we are able to achieve satisfying detection results with values for completeness and correctness up to more than 86%. By fitting an object specific vehicle model into the vehicle detections, we are able to reconstruct the vehicles in 3D and to derive pose estimations as well as shape parameters for each vehicle. To deal with the intra-class variability of vehicles, we make use of a deformable 3D active shape model learned from 3D CAD vehicle data in our model fitting approach. While we achieve encouraging values up to 67.2% for correct position estimations, we are facing larger problems concerning the orientation estimation. The evaluation is done by using the object detection and orientation estimation benchmark of the KITTI dataset (Geiger et al., 2012).

Geothermal aquifers may be considered as a renewable resource of heat and energy. Internal earth heat may be transported with underground water to the surface by wells, and to not overexploit the aquifer, this water should be returned back. As a rule such systems consist of two wells. Hot water from the producing well is used, as example, for greenhouse complex or other buildings needs, which cools the water, and the injection well returns the cold water into the aquifer. To simulate this open geothermal system a three-dimensional nonstationary mathematical model and numerical algorithms are developed taking into account the most important physical and technical parameters of the wells to describe the heat distribution and thermal water transportation in the aquifer. Results of numerical calculations are presented. © Published under licence by IOP Publishing Ltd.

We have proposed a new canonical-isokinetic ensemble for efficient sampling of conformational space in molecular dynamics (MD) simulations which leads to the optimised isokinetic Nosé-Hoover (OIN) chain algorithm for atomic and molecular systems. We applied OIN to multiple time step (MTS) MD simulations of the rigid and flexible models of water to demonstrate its advantage over the standard canonical, isokinetic and canonical-isokinetic ensembles. With the stabilising effect of OIN thermostatting in MTS-MD, gigantic outer time steps up to picoseconds can be employed to accurately calculate equilibrium and conformational properties. Furthermore, we developed the atomic version of OIN for MTS-MD of a biomolecule in a solvent potential of mean force obtained at sequential MD steps by using the molecular theory of solvation, aka three-dimensional reference interaction site model with the Kovalenko-Hirata closure (3D-RISM-KH). The solvation forces are obtained analytically by converging the 3D-RISM-KH integral equations once per several OIN outer time steps, and are calculated in between by using solvation force-coordinate extrapolation (SFCE) in the subspace of previous successive solutions to 3D-RISM-KH. For illustration, we applied the multiscale OIN/SFCE/3D-RISM-KH algorithm to a fully flexible model of alanine dipeptide in aqueous solution. Although the computational rate of solvent sampling in OIN/SFCE/3D-RISM-KH is already 20 times faster than standard MD with explicit solvent, further substantial acceleration of sampling stems from making solute evolution steps in a statistically averaged potential of mean force obtained from 3D-RISM-KH. The latter efficiently samples the phase space for essential events with rare statistics such as exchange and localisation of solvent and ligand molecules in confined spaces, pockets and at binding sites of the solute macromolecule, as distinct from MD with explicit solvent which requires enormous computational time and number of steps in such cases. © 2013 Taylor & Francis Group, LLC.

The results of the three-dimensional computer and analytical simulation are presented for the kinetics of chain-shaped aggregate growth in suspensions of magnetizable non-Brownian particles. The results of the computer experiment show that, when the volume fraction of particles is no larger than 2-3%, chain-shaped aggregates are formed in the suspensions under the action of a field. The dependence of average number of particles in a chain on time t is adequately described by the power law = Ct k . The experiment indicates that, in contract to the common power approximations, in which exponent k is considered to be a universal constant parameter, it depends on the concentration of particles and their interactions with walls bounding a suspension. At concentrations noticeably exceeding 2-3%, dense bulk aggregates are formed in suspensions. The kinetics of their growth depends on the sizes of a suspension-containing vessel. © 2013 Pleiades Publishing, Ltd.

International audience; A technique is presented for improving the structural analysis of natural fractures development in large scale fold structures. A 3D restoration of a fold provides the external displacement loading conditions to solve, by the finite element method, the forward mechanical problem of an idealized rock material with a stress-strain relationship based on the activation of pervasive fracture sets. In this elasto-plasticity constitutive law, any activated fracture set contributes to the total plastic strain by either an opening or a sliding mode of rock failure. Inherited versus syn-folding fracture sets development can be studied using this mechanical model. The workflow of this methodology was applied to the Weber sandstone formation deformed by forced folding at Split Mountain Anticline, Utah for which the different fracture sets were created and developed successively during the Sevier and the syn-folding Laramide orogenic phases. The field observations at the top stratigraphic surface of the Weber sandstone lead to classify the fracture sets into a pre-fold WNW-ESE fracture set, and a NE-SW fracture set post-dating the former. The development and relative chronology of the fracture sets are discussed based on the geomechanical modeling results. Starting with a 3D restoration of the Split Mountain Anticline, three fold-fracture development models were generated, alternately assuming that the WNW-ESE fracture set is either present or absent prior to folding process. Depending on the initial fracture configuration, the calculated fracture patterns are markedly different, showing that assuming a WNW-ESE joint set to predate the fold best correlates with field observations. This study is a first step addressing the complex problem of identification of fold-related fracturing events using an elementary concept of rock mechanics. When tight to complementary field observations, including petrography, diagenesis and burial history, the approach can be used to better constrain fractured reservoir characterization. © 2012.