High-quality microwave absorber materials play a crucial role in the efficient and uniform processing of variety of materials through microwave hybrid heating. Silicon carbide (SiC) is an excellent ...microwave absorber at room temperature, which enhances the heating rate of the target materials significantly. In the present study, effects of heat insulation materials and their configurations on microwave heating characteristics of SiC were investigated at different power levels. The responses were assessed in terms of the heating capability (maximum temperature achieved), radiation heat loss, temperature gradient, and heating uniformity under different parametric conditions. A 3D COMSOL Multiphysics simulation model, coupled with microwave heating and heat transfer module, was developed with surface-to-ambient radiation boundary conditions. Electromagnetic and thermal properties of the SiC utilized in the model were selected based on physical properties, such as porosity/density, particle size, and chemical composition of SiC. The model outputs were validated with experimental findings. Results showed that microwave heating characteristics were highly sensitive to the susceptor (SiC) properties, insulation materials and power levels. Insulation materials prevented heat losses significantly; at the same time, different insulation configurations altered the electrical field intensity distribution within the SiC sample, which affected the responses. Microwave power levels also influenced the responses and quantity of insulation required.
The dissemination of the tangible and intangible values of heritage building represents one of the most important objectives in the field of Digital Cultural Heritage (DCH). In recent years, ...different studies and research applied to heritage monuments have shown how it is possible to improve the awareness of the architectural heritage through the integration of latest developments in the field of 3D survey, 3D modelling, Building Information Modeling (BIM) and eXtended Reality (XR). On the other hand, this digital workflow requires a huge amount of data sources and a holistic approach to reach a high level of information sharing coming from different disciplines and sectors such as restoration, geomatics, 3D virtual museums and serious gaming. In conjunction with entertainment software and gaming, this research shows the main results obtained during the generative process of digital environments oriented to improve the level of information and to enrich the contents coming from the informative models. The case study is represented by one of the most important Lombard monuments: the Basilica of Sant’Ambrogio in Milan. This study, starting from the 3D survey and the data collection of the historical records of the church, improves the creation of an XR experience that reaches a new level of interactivity for different types of devices (desktop, mobile, VR headset) and users (experts, non-experts).Highlights:Generative modelling requirements and novel grades of generations (GOG) and accuracy (GOA) are presented in order to improve the digitisation of built heritage from the 3D survey, reducing time and costs of the scan-to-BIM process.The holistic value of generative modelling allows experts to create digital worlds able to faithfully and accurately represent the detected reality and improve new immersive environments for Virtual Reality (VR) and Augmented Reality (AR) projects.Immersive environments are created with a mixture of the latest generation software and hardware, allowing users to discover the hidden historical values of built heritage with new levels of interactivity and information.
Forest vegetation classification and structure measurements are fundamental steps for planning, monitoring, and evaluating large-scale forest changes including restoration treatments. High spatial ...and spectral resolution remote sensing data are critically needed to classify vegetation and measure their 3-dimensional (3D) canopy structure at the level of individual species. Here we test high-resolution lidar, hyperspectral, and multispectral data collected from unmanned aerial vehicles (UAV) and demonstrate a lidar-hyperspectral image fusion method in treated and control forests with varying tree density and canopy cover as well as in an ecotone environment to represent a gradient of vegetation and topography in northern Arizona, U.S.A. The fusion performs better (88% overall accuracy) than either data type alone, particularly for species with similar spectral signatures, but different canopy sizes. The lidar data provides estimates of individual tree height (R2=0.90; RMSE=2.3m) and crown diameter (R2=0.72; RMSE=0.71m) as well as total tree canopy cover (R2=0.87; RMSE=9.5%) and tree density (R2=0.77; RMSE=0.69 trees/cell) in 10m cells across thin only, burn only, thin-and-burn, and control treatments, where tree cover and density ranged between 22 and 50% and 1–3.5 trees/cell, respectively. The lidar data also produces highly accurate digital elevation model (DEM) (R2=0.92; RMSE=0.75m). In comparison, 3D data derived from the multispectral data via structure-from-motion produced lower correlations with field-measured variables, especially in dense and structurally complex forests. The lidar, hyperspectral, and multispectral sensors, and the methods demonstrated here can be widely applied across a gradient of vegetation and topography for monitoring landscapes undergoing large-scale changes such as the forests in the southwestern U.S.A.
•Forest thinning and prescribed burning result in subtle changes.•Such changes require high resolution data to estimate.•UAV lidar and hyperspectral image fusion performs well in such estimates.•Structure-from motion data performs less well, but adequately.
•3D CFD model incorporates total recirculation and single pass modes of operation.•3D CFD model predicts experimental data in a wide range of reactant concentrations.•Kinetic constant from 2D is 17% ...overestimated compared to 3D result.•3D model appears to give more realistic estimation than the 2D.
This paper presents the estimation of adsorption rate and apparent kinetic rate constants for photodegradation of 4-nitrophenol in a recirculating and single-pass photocatalytic microreactor using simulated solar radiation. The effect of changing initial concentration (Co) of 4-nitrophenol in a recirculation mode was predicted by employing a dynamic transport model with kinetics (momentum and mole transports) using COMSOL Multiphysics. Adsorption and kinetic rate constants were estimated by fitting 3D model to experimental data. The estimated monolayer (m) and multilayer (n) adsorption–desorption rate constants were 1.77x104 m3 mol-1 h−1 (kads,m), 0.0252 h−1 (kdes,m), 1.77x104 m3 mol-1 h−1 (kads,n) and 0.0126 h−1 (kdes,n) respectively; and apparent kinetic constant (kapp) was 2.16 h−1. Results from the single pass model showed that a rise in Co produces an increase in initial degradation rate. Moreover, decreasing flow rate (Q), increasing microchannel length (L) and decreasing microchannel height (h) boost the overall conversion of 4-nitrophenol in solution. This work demonstrates the promising application of microreactors in heterogeneous photocatalysis as tertiary stage technology for wastewater treatment, especially for the photodegradation of recalcitrant pollutant.
The Covid-19 a pandemic infectious disease and affected life across the world resulting in over 188.65 million confirmed cases across 223 countries, territories and areas with 4.06 million deaths. It ...is caused by a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and spike (S) protein of SARS-CoV-2, which plays a key role in the receptor recognition and cell membrane fusion process, is composed of two subunits, S1 and S2. The S1 subunit contains a receptor-binding domain (RBD) that recognizes and binds to the host receptor angiotensin-converting enzyme 2 (ACE2), while the S2 subunit mediates viral cell membrane fusion. Hence, it is a key target for developing neutralizing antibodies. Here, we have performed phylogenetic analysis and structural modeling of the SARS-CoV-2 spike glycoprotein, which is found highly conserved. The overall percent protein sequence identity from the SARS-CoV-2 spike protein sequences from the NCBI database was 99.68%. The functional domains of the S protein reveal that the S1 subunit was highly conserved (99.70%) than the S2 subunit (99.66%). Further, the 319–541 residues (RBD) of amino acids within the S1 domain were 100% similar among the spike protein. The 3D modeling of SARS-CoV-2 spike glycoprotein indicated that S protein has four domains with five protein units and the S1 subunit from 1 to 289 amino acid of domain 1 is highly conserved without any change in the ligand interaction site. This analysis clearly suggests that the S1 subunit (RBD 319–541) can be used as a target region for stable and safe vaccine development.
Contamination of aquatic environments has been steadily increasing due to human activities. The Pacific oyster Crassostrea gigas has been used as a key species in studies assessing the impacts of ...contaminants on human health and the aquatic biome. In this context, cytochrome P450 (CYPs) play a crucial role in xenobiotic metabolism. In vertebrates many of these CYPs are regulated by nuclear receptors (NRs) and little is known about the NRs role in C. gigas. Particularly, the CgNR5A represents a homologue of SF1 and LRH-1 found in vertebrates. Members of this group can regulate genes of CYPs involved in lipid/steroid metabolism, with their activity regulated by other NR, called as DAX-1, generating a NR complex on DNA response elements (REs). As C. gigas does not exhibit steroid biosynthesis pathways, CgNR5A may play other physiological roles. To clarify this issue, we conducted an in silico investigation of the interaction between CgNR5A and DNA to identify potential C. gigas CYP target genes. Using molecular docking and dynamics simulations of the CgNR5A on DNA molecules, we identified a monomeric interaction with extended REs. This RE was found in the promoter region of 30 CYP genes and also the NR CgDAX. When the upstream regulatory region was analyzed, CYP2C39, CYP3A11, CYP4C21, CYP7A1, CYP17A1, and CYP27C1 were mapped as the main genes regulated by CgNR5A. These identified CYPs belong to families known for their involvement in xenobiotic and lipid/steroid metabolism. Furthermore, we reconstructed a trimeric complex, previously proposed for vertebrates, with CgNR5A:CgDAX and subjected it to molecular dynamics simulations analysis. Heterotrimeric complex remained stable during the simulations, suggesting that CgDAX may modulate CgNR5A transcriptional activity. This study provides insights into the potential physiological processes involving these NRs in the regulation of CYPs associated with xenobiotic and steroid/lipid metabolism.
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•3D modeling and molecular dynamics simulations of the NR5A were conducted, predicting a monomeric DNA binding interaction.•CYP2C39, CYP3A11, CYP4C21, CYP7A1, CYP17A1, CYP27C1 and CgDAX genes, have been identified as promising targets of CgNR5A.•Molecular dynamics simulations of CgNR5A-CgDAX suggest a potential regulatory role of CgDAX in the activity of CgNR5A.
Hybrid columns of FGM/FML type with inhomogeneous transverse structure perpendicular to their length are discussed. After that, laminated columns with different layups of laminate plies are ...discussed, with focus put on the effect exerted by many coupling of the stiffness submatrix on the lowest eigenvalue load. All columns were simply supported The study uses three methods for determining the lowest eigenvalues. The first two are analytical beam methods (i.e. 1D modelling approaches) based on the use of the Euler-Bernoulli theory. The proposed 1D methods are a generalisation of the well-known approach of determining the lowest eigenloads of isotropic columns. The first approach is to solve the eigenproblem directly from the differential equation of the deflection line. The second approach assumes that the curvature of the beam depends on the susceptibility of the beam. This is a fundamental assumption in the bending theory of beams and thin plates. The third method is the FEM (3D shell approach) which is used for the verification of the previous calculations. A comparison of the obtained results showed that the proposed 1D (one-dimensional) approach based on the full susceptibility matrix, which is the inverse stiffness matrix was as accurate as the 3D (three-dimensional) FEM shell model. The relative difference does not exceed 3%. Second 1D approach based on the stiffness matrix yields many times unacceptable differences relative to the reference results obtained by the FEM method. This comparison clearly demonstrates that an approach based on the assumption that curvature is directly proportional to susceptibility in flexural composite structures produces accurate results for all types of coupling.
The existing literature extensively explores the impacts of stiffness matrix elements on both the linear and non-linear stability of laminate columns. However, there is a notable absence of studies focusing on the influence of susceptibility. This crucial aspect has been overlooked in prior studies. The present paper endeavors to fill this gap by shedding light on the influence of susceptibility, thereby emphasizing its significance in the analysis of laminate column stability.
Abstract This study compares empirical and topology optimization methods for reducing gear body mass. Specimens produced via empirical guidelines and topology optimization were compared to referent ...full-disc gear, focusing on stresses and deformations. Values were determined numerically (Ansys was used) and the calculation method was verified using ISO 6336. The empirical approach exhibited substantial increases in stress and deformation while topology optimization method had promising outcomes. While decreasing mass, it also diminished tooth root stress on the tensile side by 17.1%.
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