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Computational modeling of passive transport of functionalized nanoparticles
Get PDFFunctionalized nanoparticles (NPs) are complex objects present in a variety of systems ranging from synthetic grafted nanoparticles to viruses. The morphology and number of the decorating groups can vary widely between systems. Thus, the modeling of functionalized NPs typically considers simplified spherical objects as a first-order approximation. At the nanoscale label, complex hydrodynamic interactions are expected to emerge as the morphological features of the particles change, and they can be further amplified when the NPs are confined or near walls. Direct estimation of these variations can be inferred via diffusion coefficients of the NPs. However, the evaluation of the coefficients requires an improved representation of the NPs morphology to reproduce important features hidden by simplified spherical models. Here, we characterize the passive transport of free and confined functionalized nanoparticles using the Rigid Multi-Blob (RMB) method. The main advantage of RMB is its versatility to approximate the mobility of complex structures at the nanoscale with significant accuracy and reduced computational cost. In particular, we investigate the effect of functional groups' distribution, size, and morphology over nanoparticle translational and rotational diffusion. We identify that the presence of functional groups significantly affects the rotational diffusion of the nanoparticles; moreover, the morphology of the groups and number induce characteristic mobility reduction compared to non-functionalized nanoparticles. Confined NPs also evidenced important alterations in their diffusivity, with distinctive signatures in the off-diagonal contributions of the rotational diffusion. These results can be exploited in various applications, including biomedical, polymer nanocomposite fabrication, drug delivery, and imaging
Aeroacoustic Analysis of a Closely Installed Chevron Nozzle Jet using the High-Order Discontinuous Galerkin Method
Get PDFIn this paper, we use Large Eddy Simulations (LES) in combination with the Ffowcs Williams - Hawkings method to study the influence of chevrons on the flow field as well as the noise produced by a closely installed M = 0.6 jet. The LES simulations are performed with the spectral/hp element framework Nektar++. Nektar++ uses the high-order discontinuous Galerkin method and an implicit scheme based on the matrix-free Newton-GMRES method to discretize the unfiltered Navier-Stokes equations in space and time, respectively. The far-field noise is computed using Antares. Antares solves the Ffowcs Williams - Hawkings equation for a permeable integration surface in the time-domain using a source-time dominant algorithm. The aerodynamic results show good agreement with experimental data obtained in the Doak Laboratory Flight Jet Rig, located at the University of Southampton. Some discrepancies are observed in terms of the far-field noise levels, especially for higher polar observer angles relative to the downstream jet axis. In terms of noise reduction potential, the simulations predict that the chevrons reduce the OASPL by 1dB compared to an installed round nozzle for all observers located on the unshielded side of the wing. This should be compared to the experiments, which predict a 1.5dB noise reduction for the same chevron nozzle
Numerical simulations of thixotropic semi-solid aluminium alloys in open-rotor and rotor-stator mixers
Get PDFThis research uses the Bautista-Manero-Puig (BMP) model to examine flow patterns of semi-solid aluminium alloys (Al) in open-rotor and stator-rotor mixers via numerical solutions. The model captures the distinct thixo-viscoelastic behavior of the Al-alloys at low temperatures, near melting point. The analysis involves using 2D structured-meshes for open-rotor and rotor-stator geometries. Solutions for Newtonian and thixo-viscoelastic model fluids are reported through fields of velocity, strain-rate, stress, fluidity, and streamlines, revealing distinct features. Findings reveal nonlinear thixo-viscoelastic vortex patterns that vary with rotational speed, resulting in different fluidity and stress profiles compared to the invariant response of Newtonian fluids. At lower rotational speeds, rotor-pallets are dominated by structured material that gradually becomes unstructured to cover the outer vessel walls. When including a stator, the inner stator region resembles the Newtonian solution, but the outflow through stator gaps is reduced due to flow-structure levels outside. This information is of interest for industrial design and optimization of molten Al-alloy processing.Programa de Transferencia de Tecnología de la DFB
FEDER
Consejo Nacional de Ciencias, Humanidades y Tecnologı́as (CONAHCYT, Mexico)
Universidad Nacional Autónoma de México UNA
Constant probe orientation for fast contact-based inspection of 3D free-form surfaces using (3+2)-axis inspection machines
Get PDFA new probe optimization method for contact based (3+2)-axis inspection machines is proposed. Given an inspection path of a stylus on a free-form surface, an optimal orientation of the stylus is computed such that (i) the inclination angle of the stylus is within a given angular range with respect to the surface normal, (ii) the motion of the stylus is globally collision free, and (iii) the stylus remains constant in the coordinate system of the measuring machine. The last condition guarantees that the inspection motion requires only the involvement of the three translational axes of the measuring machine. The numerical simulations were validated through physical experiments on a testcase of a tooth of a bevel gear due to the surface complexity and probe accessibility. This optimized method was compared to 3-axis and 5-axis inspection strategies, showing that the fixed (3+2)-axis stylus returns more accurate inspection results compared to the traditional 3-axis approach and similar to 5-axis approach
Resource-Efficient High-Dimensional Entanglement Detection via Symmetric Projections
Get PDFWe introduce two families of criteria for detecting and quantifying the entanglement of a bipartite quantum state of arbitrary local dimension. The first is based on measurements in mutually unbiased bases and the second is based on equiangular measurements. Both criteria give a qualitative result in terms of the state's entanglement dimension and a quantitative result in terms of its fidelity with the maximally entangled state. The criteria are universally applicable since no assumptions on the state are required. Moreover, the experimenter can control the trade-off between resource-efficiency and noise-tolerance by selecting the number of measurements performed. For paradigmatic noise models, we show that only a small number of measurements are necessary to achieve nearly-optimal detection in any dimension. The number of global product projections scales only linearly in the local dimension, thus paving the way for detection and quantification of very high-dimensional entanglement
A First Rigorous Attempt to Explain Charge Transport in a Protein-Ligand complex
Get PDFRecent experimental evidence shows that when a protein (or peptide) binds to its ligand pair, the protein effectively “switches on” enabling long-range charge transport within the protein. Astonishingly, the protein-ligand complex exhibits conductances in the order of nanosiemens over distances of many nanometers and macroscopic Ohm’s law emerges. Here, we investigate this emergent phenomenon via the framework of many-body (fermionic) quantum statistical principles. We propose a simple model
which gives rise to an Ohm’s law with vanishing quantum effects in its thermodynamic limit (with respect to length scales). Specifically, we consider protein-ligand complexes as a two-band 1D lattice Hamiltonian system in which charge carriers (electrons or holes) are assumed to be quasi-free. We investigate theoretically and numerically the behavior of the microscopic
current densities with respect to varying voltage, temperature and length within reasonable physiological parameter ranges. We compute the current observable at each site of the protein-ligand lattice and demonstrate how the local microscopic charge transport behavior generates the macroscopic current. The overall framework contributes to the search for unifying
principles for long-range charge transport and associated emergent laws in protein complexes, which is crucial for bioelectronics.Project of Basque Government through the grant IT1615-22.Ikerbasque (The Basque Foundation for Science), BCAM Severo Ochoa accreditation CEX2021-001142-S / MICIN / AEI / 10.13039/501100011033, grant RTI2018-093860-B-C21 funded by (AEI/FEDER, UE) and acronym “MathNEURO”. COST Action CA18232 financed by the European Cooperation in Science and Technology (COST). Project PID2020-112948GB-I00 funded by MCIN/AEI/10.13039/501100011033 and by "ERDF A way of making Europe". Project PID2020-117281GB-I00 and PID2019-107444GA-I00, partly from European Regional Development Fund (ERDF), and the Basque Government, grant IT1483-22
Some consequences of the μ-constant condition for families of surfaces
No full textLet f:X→Δ be a 1-parameter family of 2-dimensional isolated hypersurface singularities. In this paper, we show that if the Milnor number is constant, then any semistable model, obtained from f after a sufficiently large base change must satisfy non trivial restrictions. Those restrictions are in terms of the dual complex, Hodge structure and numerical invariants of the central fibre.Programa Predoctoral de Formación de Personal Investigador No Doctor of the Basque Government Department of Education
SEV-2023-2026
BCAM Severo Ochoa accreditation CEX2021-001142-S / MICIN / AEI / 10.13039/501100011033
Reducing Model Complexity by Means of the Optimal Scaling: Population Balance Model for Latex Particles Morphology Formation.
Get PDFRational computer-aided design of multiphase polymer materials is vital for rapid progress in many important applications, such as: diagnostic tests, drug delivery, coatings , additives for constructing materials, cosmetics, etc. Several property predictive models, including the prospective Population Balance Model for Latex Particles Morphology Formation (LPMF PBM), have already been developed for such materials. However, they lack computational efficiency, and the accurate prediction of materials’ properties still remains a great challenge . To enhance performance of the LPMF PBM, we explore the feasibility of reducing its complexity through disregard of the aggregation terms of the model. The introduced nondimensionalization approach, which we call Optimal Scaling with Constraints, suggests a quantitative criterion for locating regions of slow and fast aggregation and helps to derive a family of dimensionless LPMF PBM of reduced complexity. The mathematical analysis of this new family is also provided. When compared with the original LPMF PBM, the resulting models demonstrate several orders of magnitude better computational efficiency.The BERC 2018e2021 grant and the following ELKARTEK projects were also acknowledged: KK-2021/0 0 022, KK-2021/0 0 064 and KK-2022/0 0 0 06K
SilionBurmuin: A Horizon Europe propelled Neurocomputing Initiative in the Basque Country
No full textSiliconBurmuin is aimed at creating a multi-disciplinary neurocomputing community in the Basque Country, bringing together technology and scientific research centres and industry companies. This community will: (1) identify key biological structures and mechanisms that play a major role in vision across species, and (2) transform this knowledge into novel mathematical formalisms, neuromorphic designs and algorithms to solve industry challenges and enable new experiments of interest in neuroscience and clinical research. To achieve the latter objective in a time-effective manner, SiliconBurmuin will draw strong connections with the ongoing Horizon Europe Nim-bleAI project, with which it shares coordination. This is expected to allow reinforcement of ideas, knowledge and technology via a common prototyping platform where to implement IP from both projects. In addition to describing the research objectives and direction of SiliconBurmuin, this paper posits that co-coordination and co-funding of aligned projects at EU and regional levels might well be a catalyst for raising regional self-awareness of own potential and develop it to help fulfill global challenges, such as semiconductor sovereignty.Elkartek project SILICON BURMUIN no. KK-2023/00090
Computation of the regularized incomplete Beta function
Get PDFAn algorithm for the computation of the regularized incomplete Beta function is described. This function has important applications in areas such as Statistics, Physics and Information Theory. The computation of the function can be carried out through a continued function evaluation supplemented with series and asymptotic expansions when both parameters are large. Numerical tests demonstrate the accuracy of the algorithm and show that our algorithm is more accurate than Matlab’s built-in function betainc for a wide range of parameters