2D Sections Research Articles

Thermal Effects at Continent-Ocean Transform Margins: A 3D Perspective

Continental breakup along transform margins produces a sequence of (1) continent-continent, (2) continent-oceanic, (3) continent-ridge, and (4) continent-oceanic juxtapositions. Spreading ridges are the main sources of heat, which is then distributed by diffusion and advection. Previous work focused on the thermal evolution of transform margins built on 2D numerical models. Here we use a 3D FEM model to obtain the first order evolution of temperature, uplift/subsidence, and thermal maturity of potential source rocks. Snapshots for all four transform phases are provided by 2D sections across the margin. Our 3D approach yields thermal values that lie in between the previously established 2D end-member models. Additionally, the 3D model shows heat transfer into the continental lithosphere across the transform margin during the continental-continental transform stage ignored in previous studies. The largest values for all investigated quantities in the continental area are found along the transform segment between the two ridges, with the maximum values occurring near the transform-ridge corner of the trailing continental edge. This boundary segment records the maximum thermal effect up to 100 km distance from the transform. We also compare the impact of spreading rates on the thermal distribution within the lithosphere. The extent of the perturbation into the continental areas is reduced in the faster models due to the reduced exposure times. The overall pattern is similar and the maximum values next to the transform margin is essentially unchanged. Varying material properties in the upper crust of the continental areas has only a minor influence.

3D reconstruction of two-phase random heterogeneous material from 2D sections: An approach via genetic algorithms

This paper introduces a method to reconstruct the three-dimensional (3D) microstructure of two-phase materials, e.g., porous materials such as highly irradiated nuclear fuel, from two-dimensional (2D) sections via a multi-objective optimization genetic algorithm. The optimization is based on the comparison between the reference and reconstructed 2D sections on specific target properties, i.e., 2D pore number, and mean value and standard deviation of the pore-size distribution. This represents a multi-objective fitness function subject to weaker hypotheses compared to state-of-the-art methods based on n-points correlations, allowing for a broader range of application. The effectiveness of the proposed method is demonstrated on synthetic data and compared with state-of-the-art methods adopting a fitness based on 2D correlations. The method here developed can be used as a cost-effective tool to reconstruct the pore structure in highly irradiated materials using 2D experimental data.

High-Temperature Area of the Fe-Ni-Co-Cu Phase Diagram: Experimental Study and Computer Design

Experimental study of phase equilibria in quaternary Fe-Ni-Co-Cu system has been carried out using differential thermal analysis, scanning electron microscopy and energy dispersive x-ray spectrometry. Experimental data obtained for several synthesized alloys in the Fe-Ni-Co-Cu system have been used for plotting the liquidus and solidus hypersurfaces projections also for design and verification of the T-x-y-z phase diagram. The 4D geometrical description of the Fe-Ni-Co-Cu system, plotted with applying fundamental geometrical principles of phase diagrams design, facilitates visualization of the liquidus and solidus hypersurfaces in 2D and 3D formats, and the entire four-dimensional T-x-y-z phase diagram using any 2D or 3D sections.

Determining of optimum operation modes of a diesel engine with a multi-component bio-fuel composition

A problem of reduced number of tests was identified during the determining of optimal load and speed performance of a diesel engine with a multi-component bio-fuel composition. The planning method of the experiment for determining of effective ICE performance was improved. For factor space description, graph analyses were carried out using a semi-rotatable 2nd order Box-Behnken statistical design for three factors. The operation studies of a 4ChN 11,0/12,5 diesel engine were performed with the most stable multi-component bio-fuel composition, including the following ingredients, % wt.: RSO – 34.5; ethanol – 31.0; DF – 34.5. The analysis of regression models and 2D sections of response surfaces provided for determining of the optimum advance angle of fuel injection Θɞnp. = 23.5 deg. to TDC. By method of superposition of the 2D sections of the response surfaces of the effective efficiency ηe and the specific effective fuel consumption ge a search for a compromise solution on optimum combination of the levels of the factors to be studied. It was found out that the optimum area of the combination of factors is located in the range of the crankshaft rpm n = 1400…1550 min−1 of the diesel engine and in the effective load range Pe = 0.68…0.85 MPa. Under recognition of the variable nature of the load and speed modes of a diesel engine in a real operation environment, the obtained data are of practical interest.

Shape characterization methods of irregular cavity using Fourier analysis in tunnel

The erosion of soluble rock and transformation of groundwater result in the high geometrical irregularity of cavities in nature. The purpose of this paper is to quantitatively describe the shape of irregular cavities using Fourier transform analysis. Firstly, multi-level characterization indexes of the 2D section of cavities have been proposed, considering the high shape irregularity of cavities. The first level indexes include Shape Factor (SF), Aspect Ratio (AR) and Sphere Like (SL). The second level indexes consist of Angularity Factor (AF) and Convexity Factor (CF). The third level indexes are Roundness Factor (RF). Then, the geometric contour of cavity was transformed into a 2D waveform, with an equal-angle points sampling of the cavity boundary. The geometric boundary of irregular cavity was segmented and transformed from discrete time domain to frequency domain based on discrete Fourier transform (DFT). Furthermore, we proposed Fourier shape descriptor, which was found to control the cavity shape. The relationship between Fourier shape descriptors in different sequences and multi-level characterization indexes was determined using designed and irregular nature cavities as sample data. The results demonstrated that the Fourier shape descriptors​ D2, D3 and D8 mainly control multi-level characterization indexes including the overall shape, the irregularity and the roughness of the cavity boundary, respectively. Finally, the 3D characterization method of cavity shape was further proposed based on averaging the 2D sections, which hence offers a possible way to further quantitatively study the mechanical properties of surrounding rockmass effected by the irregular shape of cavities.

Digital Vacone

Between 2016 and 2018, excavations at the Roman villa of Vacone, carried out by the Upper Sabina Tiberina Project, transitioned to completely digital recording practices. The methodological shift was accompanied by a three-year campaign of backfill removal and cleaning, which allowed most of the villa’s extant architecture and décor uncovered since 2012 to be digitized. Moreover, a new documentation protocol was established that employs photogrammetry in lieu of scale drawing to model the three-dimensional spatial characteristics of every archaeological context. Notable artifacts were also modeled to facilitate off-site study. The excavation’s experiences with this conversion offer valuable lessons for other long-term archaeological projects contemplating a similar shift amid active fieldwork. The project’s digital recording team developed a methodology for layer-by-layer modeling that ensures precise alignment between stratigraphic contexts using fixed markers. From these, standard 2D products (orthomosaic plans and digital elevation models [DEMs]) were produced. A similar technique was used for generating 2D orthomosaics of vertical features (such as walls and stratigraphic sections) without the need to take numerous measurements on the vertical surface (e.g., with a prismless total station). Similarly, the generated data can create 2D sections along any arbitrary line even after the strata have been removed. Beyond simply replicating traditional two-dimensional records, the 3D data have proven essential for visualizing the interrelation of above and below ground spaces, and for analyzing a terraced structure built on several levels. Composite 3D models, hosted online, are also an effective tool for public outreach with stakeholders in the local community, as well as the general public.

3D neural circuit visualization by neural tracing and tissue clearing for dementia study

AbstractBackgroundTo date, different techniques were developed for mapping neural connections, including diffusion tensor imaging (DTI) and neural tracers. DTI allows tracing of connections in macroscale but with low resolution. While neural tracers can allow visualization at single cell level, their signals are usually visualized in 2D sections. This results in missing information from the damages of brain tissues during tissue sectioning and inaccuracy of computation reconstruction. Therefore, we decided to trace neural circuits by using neural tracers in 3D intact tissues instead of 2D sections. In this study, we aim to establish 3D visualization protocol by combining neural tracing and tissue clearing techniques. We tested the potential of this protocol on tracing the neural circuit involved in Parkinson’s disease dementia (PDD) by using both chemical‐based and viral‐based neural tracers. Medial forebrain bundle (MFB) connects striatum, substantia nigra and frontal cortex. We at first focused on dopaminergic pathway projecting from MFB.MethodCholera toxin subunit B (CTB) conjugated with Alexa Fluor‐647 (CTB‐647) or adeno‐associated virus (AAV) expressing nerve growth factor and green fluorescent protein (AAV‐NGF‐GFP) was injected into MFB by stereotaxic injection. The rats were then euthanized by perfusion at different day points (10 days for CTB‐647; 5 weeks for AAV‐NGF‐GFP) after the injection. The brains were treated with 4% sodium dodecyl sulfate (SDS) plus Optical Properties‐adjusting Tissue Clearing agent (OPTIClear) solution for 5 days and then incubated into OPTClear solution for 2 days. The fluorescent signals were visualized by confocal microscopy.ResultCTB‐647 and AAV‐NGF‐GFP signals were detected in striatum. It showed that the CTB‐647 can travel from MFB to striatum through nigrostriatal pathway, while AAV‐NGF‐GFP can be absorbed by the neurons projecting from MFB to striatum to express green fluorescent proteins. It is feasible to trace neural circuits by neural tracing with tissue clearing.ConclusionTaken together, nigrostriatal pathway, connecting substantia nigra and striatum, can be traced by using neural tracers together with tissue clearing. With this protocol, the neural circuits related to the dementia processes in PD can be further studied. Acknowledgement: The study is supported by Seed Funding for Translational and Applied Research (201910160016) to RCCC.

Application of numerical modelling for determining the optimal position of the suction slot in the steam turbine vane cascade

The numerical investigations of liquid film development in the last stages of steam turbines were performed. This data was used to suggest the position of the suction slot used to evacuate the liquid phase from the turbine flow path. The object of study is a periphery 2D section of vanes cascade. The movement of coarse droplets in the blade passage was simulated. Their collision with the blade surfaces results in the appearance of additional sources of mass and momentum for liquid film. The influence of theoretical Mach number on the features of liquid film formation was studied. The distributions of main characteristics, reflecting the formation of the film, have been obtained. They were used to analyse the liquid phase flow along the surfaces and to point out base recommendations about the location of the suction slot.

Integration of diagenesis in basin-scale, stratigraphic forward models using reactive transport modeling: Input and scaling issues

This article presents an integrated approach based on stratigraphic forward modeling and reactive transport modeling to adequately represent the development of a mixed siliciclastic-carbonate sedimentary system and its diagenesis. This work was realized on a realistic case study, the Oligo-Miocene series of Carry-le-Rouet, South-East of France, characterized by a complex pattern of bioclastic, bioconstructed and siliciclastic deposits, and affected by several exposure surfaces and associated meteoric diagenesis. A first phase consisted in building a stratigraphic forward model (SFM), using the software DionisosFlow. The construction of the model was based on sensitivity tests on the two main parameters controlling basin sedimentation: 1) competition between carbonate production and siliciclastic supply; 2) subsidence. The results of the simulations, especially the facies distribution, the thickness of the deposits and the sedimentary architectures were compared with the observed data to validate the model. A second phase consisted in focusing on a specific stratigraphic event and performing reactive transport modeling (RTM) on a 2D section extracted from the DionisosFlow model to evaluate the mineralogical transformations and resulting petrophysical evolutions created by early diagenesis. The calculation results show the occurrence of two domains of salinity, that were associated with two distinct diagenetic environments: marine and meteoric phreatic. Globally, the simulated diagenetic trends are qualitatively consistent with the petrographic observations, except for the replacement of aragonite by a calcite cement, that systematically occurred in the model and is not always observed in thin sections. This preliminary study emphasizes the issues associated with the application of RTM to diagenetic phenomena, linked with the uncertainties inherent to specific parameters, such as minerals kinetic properties, and the mismatch between the space and time scales of the modeled processes and the upscaled description of each SFM cell. These results argue in favor of an alternative solution, that could conciliate the different processes. The combination of the various SFM output properties with simplified chemical reactions whose rates have been tuned for specific diagenetic processes of interest could provide diagenetic risk maps that would constitute useful guides for exploration at basin scale.

Detection of Cover Collapse Doline and Other Epikarst Features by Multiple Geophysical Techniques, Case Study of Tarimba Cave, Brazil

Reliable characterization of the karst system is essential for risk assessment where many associated hazards (e.g., cover-collapse dolines and groundwater pollution) can affect natural and built environments, threatening public safety. The use of multiple geophysical approaches may offer an improved way to investigate such cover-collapse sinkholes and aid in geohazard risk assessments. In this paper, covered karst, which has two types of shallow caves (vadose and fluvial) located in Tarimba (Goias, Brazil), was investigated using various geophysical methods to evaluate their efficiency in the delineation of the geometry of sediments filled sinkhole. The methods used for the investigation were Electrical Resistivity Tomography (ERT), Seismic Refraction Survey (SRS), Seismic Refraction Tomography (SRT) and the Very Low Frequency Electromagnetic (VLF-EM) method. The study developed several (2D) sections of the measured physical properties, including P-wave velocity and electrical resistivity, as well as the induced current (because of local bodies). For the analysis and processing of the data obtained from these methods, the following approaches were adopted: ERT inversion using a least-square scheme, Karous-Hjelt filter for VLF-EM data and time-distance curves and Vp cross-sections for the SRS. The refraction data analysis showed three-layered stratigraphy topsoil, claystone and carbonate bedrock, respectively. The findings obtained from ERT (three-layered stratigraphy and sediment-filled doline), as well as VLF-EM (fractured or filled caves as a positive anomaly), were found to be consistent with the actual field conditions. However, the SRS and SRT methods did not show the collapsed material and reached the limited the depth because of shorter profile lengths. The study provides a reasonable basis for the development of an integrated geophysical approach for site characterization of karst systems, particularly the perched tank and collapse doline.

Quantifying intracortical bone microstructure: A critical appraisal of 2D and 3D approaches for assessing vascular canals and osteocyte lacunae.

Describing and quantifying vascular canal orientation and volume of osteocyte lacunae in bone is important in studies of bone growth, mechanics, health and disease. It is also an important element in analysing fossil bone in palaeohistology, key to understanding the growth, life and death of extinct animals. Often, bone microstructure is studied using two‐dimensional (2D) sections, and three‐dimensional (3D) shape and orientation of structures are estimated by modelling the structures using idealised geometries based on information from their cross sections. However, these methods rely on structures meeting strict geometric assumptions. Recently, 3D methods have been proposed which could provide a more accurate and robust approach to bone histology, but these have not been tested in direct comparison with their 2D counterparts in terms of accuracy and sensitivity to deviations from model assumptions. We compared 2D and 3D methodologies for estimating key microstructural traits using a combination of experimental and idealised test data sets. We generated populations of cylinders (canals) and ellipsoids (osteocyte lacunae), varying the cross‐sectional aspect ratios of cylinders and orientation of ellipsoids to test sensitivity to deviations from cylindricality and longitudinal orientation, respectively. Using published methods, based on 2D sections and 3D data sets, we estimated cylinder orientation and ellipsoid volume. We applied the same methods to six CT data sets of duck cortical bone, using the full volumes for 3D measurements and single CT slices to represent 2D sections. Using in silico test data sets that did deviate from ideal cylinders and ellipsoids resulted in inaccurate estimates of cylinder or canal orientation, and reduced accuracy in estimates of ellipsoid and lacunar volume. These results highlight the importance of using appropriate 3D imaging and quantitative methods for quantifying volume and orientation of 3D structures and offer approaches to significantly enhance our understanding of bone physiology based on accurate measures for bone microstructures.

3D mapping of intruding salt bodies in the subsurface of the Gulf of Mexico using 3D seismic data

Salt tectonics has important implications for hydrocarbon exploration in salt-bearing basins since salt deformation can directly or indirectly form hydrocarbon traps, influence hydrocarbon migration, and can control deepwater depositional systems. In various basins around the globe, extensive research has been conducted on initiation of salt mobilization, subsequent deformation, and eventual cessation, typically from subsurface two-dimensional (2D) sections. However, 3D seismic data has dominated the petroleum industry for the last 30 years. Despite the plethora of 3D seismic data acquired in salt-bearing basins, there has been hardly any published work displaying the 3D geometries of complex salt bodies. 3D salt mapping in the subsurface can reveal true distribution of salt bodies and their detailed intricacies of geometrical variations, aiding in the overall salt system interpretation. Using a large 3D seismic survey (3,350 km2), this study presents the first 3D salt mapping in the Gulf of Mexico, demonstrating how 3D visualization of the entire Louann Salt system within the Middle Jurassic to present-day stratigraphy can improve interpretation of salt feeder geometries, allochthonous salt canopies, initial salt distribution, and salt weld locations in the study area.

3D Exploration of the Brainstem in 50-Micron Resolution MRI.

The brainstem, a structure of vital importance in mammals, is currently becoming a principal focus in cognitive, affective, and clinical neuroscience. Midbrain, pontine and medullary structures serve as the conduit for signals between the forebrain and spinal cord, are the epicenter of cranial nerve-circuits and systems, and subserve such integrative functions as consciousness, emotional processing, pain, and motivation. In this study, we parcellated the nuclear masses and the principal fiber pathways that were visible in a high-resolution T2-weighted MRI dataset of 50-micron isotropic voxels of a postmortem human brainstem. Based on this analysis, we generated a detailed map of the human brainstem. To assess the validity of our maps, we compared our observations with histological maps of traditional human brainstem atlases. Given the unique capability of MRI-based morphometric analysis in generating and preserving the morphology of 3D objects from individual 2D sections, we reconstructed the motor, sensory and integrative neural systems of the brainstem and rendered them in 3D representations. We anticipate the utilization of these maps by the neuroimaging community for applications in basic neuroscience as well as in neurology, psychiatry, and neurosurgery, due to their versatile computational nature in 2D and 3D representations in a publicly available capacity.

Investigations of HAWT Airfoil Shape Characteristics and 3D Rotational Augmentation Sensitivity Toward the Aerodynamic Performance Improvement

This study investigates the impacts of dierent airfoil shapes on the 3D augmentationand power production of horizontal axis wind turbines (HAWTs). The aerodynamic eect fromchanging the leading and trailing edge of the airfoil is the emphasis of the research. Varied powerproduced from modifying sensitivity on 3D augmentations, caused by revamping airfoil shapes, areshown. The 3D correction law, considering the chord to radius ratio and the blades’ pitch angle inthe rotation, is applied to the airfoil lift coecients. The blade element method (BEM) embeddedin the software Qblade with modified lift coecients simulates the power productions of threewind turbines from these airfoils. The comparisons of the boundary layer characteristics, sectionalforces, and inflow angle of the blade sections are calculated. The k-omega SST turbulence model inOpenFoam visualizes the stall and separation of the blades’ 2D section. The airfoils with a roundedleading edge show a reduced stall and separated flow region. The power production is 2.3 timeshigher for the airfoil constructed with a more rounded leading edge S809r and two times higher forthe airfoil S809gx of the symmetric structure.

Understanding the gravity response variability of sedimentary basins using forward stratigraphic modelling

It is accepted that gravity inversions are non-unique and that multiple models will fit the data equally well. Over sedimentary basins, this implies that gravity anomalies can be equally well explained by sedimentary strata with constant densities over a highly heterogeneous basement, or by highly heterogeneous sedimentary strata over a constant density basement. While both scenarios minimise the difference between the predicted and observed gravity signal, neither are geologically plausible. In this work, we explore stratigraphic modelling as a new parameterisation for gravity models. By using a process-based numerical simulation to generate the sedimentary basins' density models we seek to focus only on geologically plausible models. We then study the variability of the sedimentary strata's gravity response (i.e. the range of possible geophysical signatures) to stratigraphic parameter changes. Results from a study of a 2D section in the Northern Carnarvon basin (the northwest shelf of Australia) emphasize that even when the stratigraphic models are trialled using a wide range of input parameters, the simulated gravity response still has a limited variability when compared to model results generated using other parameterisations. Lastly, our results provide insights into the global sensitivity of the gravity response, highlighting the sedimentary and stratigraphic parameters that most affect the geophysical signal, allowing for a discussion of the geologic and stratigraphic controls of the sedimentary basin's gravity response.

Nutil: A Pre- and Post-processing Toolbox for Histological Rodent Brain Section Images.

With recent technological advances in microscopy and image acquisition of tissue sections, further developments of tools are required for viewing, transforming, and analyzing the ever-increasing amounts of high-resolution data produced. In the field of neuroscience, histological images of whole rodent brain sections are commonly used for investigating brain connections as well as cellular and molecular organization in the normal and diseased brain, but present a problem for the typical neuroscientist with no or limited programming experience in terms of the pre- and post-processing steps needed for analysis. To meet this need we have designed Nutil, an open access and stand-alone executable software that enables automated transformations, post-processing, and analyses of 2D section images using multi-core processing (OpenMP). The software is written in C++ for efficiency, and provides the user with a clean and easy graphical user interface for specifying the input and output parameters. Nutil currently contains four separate tools: (1) A transformation toolchain named “Transform” that allows for rotation, mirroring and scaling, resizing, and renaming of very large tiled tiff images. (2) “TiffCreator” enables the generation of tiled TIFF images from other image formats such as PNG and JPEG. (3) A “Resize” tool completes the preprocessing toolset and allows downscaling of PNG and JPEG images with output in PNG format. (4) The fourth tool is a post-processing method called “Quantifier” that enables the quantification of segmented objects in the context of regions defined by brain atlas maps generated with the QuickNII software based on a 3D reference atlas (mouse or rat). The output consists of a set of report files, point cloud coordinate files for visualization in reference atlas space, and reference atlas images superimposed with color-coded objects. The Nutil software is made available by the Human Brain Project (https://www.humanbrainproject.eu) at https://www.nitrc.org/projects/nutil/.

Sloshing Motion in a Real-Scale Water Storage Tank under Nonlinear Ground Motion

Water storage tanks in cities are usually large and are occasionally affected by earthquakes. A sudden earthquake can cause pressure pulses that damage water containers severely. In this study, the sloshing motion in a high filling level tank caused by seismic excitation is investigated by the numerical method in a 2D model. Two well-studied strong earthquakes are used to analyze the broadband frequency nonlinear displacement of the tank both in the longitudinal and vertical directions. Based on careful experimental verification, the free surface motion and the elevations at the side wall are captured, and the sloshing pressure response is examined. The results show that the 2D section of the cylindrical tank can be used to estimate the maximum response of the 3D sloshing, and the water motions under the seismic excitations are consistent with the modal characteristics of the sloshing. The time histories response of the water motion reflected that the sloshing response is hysteretic compared with the seismic excitation. The anti-seismic ability of the damping baffle shows that its effect on sloshing pressure suppression is limited, and further study on the seismic design of water tanks in earthquake-prone regions is needed.

Determination of the regional and residual gravity anomalies to reconstruct basin structures of the Cauvery Basin

The measured gravity field of the Earth contains two main components of short wavelength residual anomalies and long wavelength regional anomalies. In the petroleum industry, the most important component is the residual anomalies which correlate with the shallow density variations in sedimentary basins. The regional anomalies are caused by deeper density contrasts in the lithospheric mantle and the Asthenosphere. The current study is focused to determine residual and regional gravity anomalies for understanding basin architecture of the Cauvery Basin. In this study, the basement of the Cauvery Basin was determined using two-way-travel time seismic data and well log data obtained from eight exploration wells. Depth data from selected 2D sections were used as input data for a Mathematica® program which developed based on the iterative algorithm to calculate the residual gravity anomaly caused by a 2D polygonal body having a density contrast with the surrounding. The difference of the calculated and the observed gravity was then used to obtain the regional gravity along the arbitrary survey lines. Results show that the regional gravity ranged from about -50 mGal to 70 mGal with having a relatively high gravity anomaly in the central part of the Cauvery Basin. According to the regional tectonic settings, the high gravity anomaly can indicate a crustal thinning process that occurred during the rifting phase of the basin. The residual gravity anomaly of the Cauvery Basin ranged from about -60 mGal to 20 mGal and it follows the horst and graben structures. In summary, several undiscovered sub-basins were identified related to the rifting of (i) East–West Gondwana (ca. 167 Ma, NE–SW trending structures) and (ii) the East India–Antarctica (ca. 137 Ma, NW–SE trending). Therefore, this study can be productively used for mapping the structural elements and architecture in terms of considering the most favorable locations for future hydrocarbon exploration in the Cauvery Basin.

Magnetic rocks distribution and depth to basement analysis on an old Quarry Site, Abeokuta, SW Nigeria

Geomagnetic study was carried out to investigate the distribution and depth of formations of different magnetic rocks on an old quarry site, Abeokuta, Southwestern, Nigeria. Eight ground magnetic profiles were established with 10 m spacing intervals orientated in West-East and North-South directions, and ranged between 110 and 190 m. A total of 223 data sets were acquired and corrected for all forms of magnetic variations. The resulting residual anomalies were plotted against distance using Microsoft Excel tool. Also, these anomalies were modeled into 2D and 3D contour sections using Surfer 10. The depth to basement analysis was carried out using Peter’s half slope graphical method. The resulting profiles and contour sections revealed variable anomalies which indicated contrast in the magnetic distributions of the subsurface. Mineral rocks with average (0-150 nT) magnetic susceptibilities dominated the profiles, and this indicated that the study area is on pegmatite or Quartz vein which probably harbored Beryl, Graphite, Sandstone, Quartz, Tantalite and Mica in both massive and disseminated quantities. Regions with high (150-300 nT) and low (0 to -150 nT) magnetic susceptibilities were also observed across the profiles. Mineral rocks with very thin bodies were observed at depths 3.48-17.42 m, intermediate bodies were buried at depths 2.61-13.06 m, while very thick bodies were located at depths between 2.09 and 10.45 m. The depth of the magnetic sources revealed that the major and minor mineral rock contact in the study area.

A CFD‐DEM approach to study the breakup of fractal agglomerates in an internal mixer

AbstractIn this work we present a method to investigate the breakup of filler agglomerates in an internal mixer during a compounding operation. The method employs computational fluid dynamics (CFD) simulations along with discrete element method (DEM) simulations. CFD simulations are performed to compute the flow field inside a 2D section of a typical batch internal mixer with two tangential rotors. During the CFD simulation, we assume the filler agglomerates to behave as tracer particles, carried passively by the flow. The trajectory of the tracers, together with the experienced velocity gradients, are fed to a DEM code, built in the framework of Stokesian dynamics. The code computes the mechanical response of the agglomerates along the trajectory, from which it is finally possible to ascertain the occurrence of breakup. Simulations are performed to evaluate the robustness of the method on two different rotor speed ratio conditions and varying agglomerate strength.