Uniform Source Research Articles

Cinnabar for Roman Ephesus: Material quality, processing and provenance

Ephesus was an important harbor city that flourished during the Roman period and ancient texts mention Almadén in Spain and the Cilbian fields of Ephesus as important cinnabar sources in antiquity. This work investigates whether imported cinnabar was used and whether this could be related to changes in painting activities over time. Microscopic analysis indicates a consistent preparation of cinnabar, hinting at a uniform source material quality or processing technique. However, the use of cinnabar varies among the architectural structures studied, indicating a plurality of painting techniques. A few of the analyzed cinnabar samples overlap with Turkish- and Balkan reference Pb isotope ratios; three samples from tabernas, however, deviate from this. The Hg isotope ratios reveal that cinnabar from carbonate-hosted deposits was likely used, and that processing of cinnabar included heating as suggested by ancient texts. Most notably, a correlation exists between the geochemical data and the painting technique – shifts in sourcing and cinnabar usage are potentially assignable to building chronology and/or usage. Through the lens of material provenance and processing, Ephesian cinnabar brings the organization of pigment trade into focus.

Dosimetric and biological impact of activity extravasation of radiopharmaceuticals in PET imaging.

The increasing use of nuclear medicine and PET imaging has intensified scrutiny of radiotracer extravasation. To our knowledge, this topic is understudied but holds great potential for enhancing our understanding of extravasation in clinical PET imaging. This work aims to (1) quantify the absorbed doses from radiotracer extravasation in PET imaging, both locally at the site of extravasation and with the extravasation location as a source of exposure to bodily organs and (2) assess the biological ramifications within the injection site at the cellular level. A radiation dosimetry simulation was performed using a whole-body 4D Extended Cardiac-Torso (XCAT) phantom embedded in the GATE Monte Carlo platform. A 10-mCi dose of 18F-FDG was chosen to simulate a typical clinical PET scan scenario, with 10% of the activity extravasated in the antecubital fossa of the right arm of the phantom. The extravasation volume was modeled as a 5.5mL rectangle in the hypodermal layer of skin. Absorbed dose contributions were calculated for the first two half-lives, assuming biological clearance thereafter. Dose calculations were performed as absorbed doses at the organ and skin levels. Energy deposition was simulated both at the local extravasation site and in multiple organs of interest and converted to absorbed doses based on their respective masses. Each simulation was repeated ten times to estimate Monte Carlo uncertainties. Biological impacts on cells within the extravasated volume were evaluated by randomizing cells and exposing them to a uniform radiation source of 18F and 68Ga. Particle types, their energies, and direction cosines were recorded in phase space files using a separate Geant4 simulation to characterize their entry into the nucleus of the cellular volume. Subsequently, the phase space files were imported into the TOPAS-nBio simulation to assess the extent of DNA damage, including double-strand breaks (DSBs) and single-strand breaks (SSBs). Organ-level dosimetric estimations are presented for 18F and 68Ga radionuclides in various organs of interest. With 10% extravasation, the hypodermal layer of the skin received the highest absorbed dose of 1.32±0.01Gy for 18F and 0.99±0.01Gy for 68Ga. The epidermal and dermal layers received absorbed doses of 0.07±0.01Gy and 0.13±0.01Gy for 18F, and 0.14±0.01Gy and 0.29±0.01Gy for 68Ga, respectively. In the extravasated volume, 18F caused an average absorbed dose per nucleus of 0.17±0.01Gy, estimated to result in 10.58±0.50 DSBs and 268.11±12.43 SSBs per nucleus. For 68Ga, the absorbed dose per nucleus was 0.11±0.01Gy, leading to an estimated 6.49±0.34 DSBs and 161.24±8.12 SSBs per nucleus. Absorbed doses in other organs were on the order of micro-gray (µGy). The likelihood of epidermal erythema resulting from extravasation during PET imaging is low, as the simulated absorbed doses to the epidermis remain below the thresholds that trigger such effects. Moreover, the organ-level absorbed doses were found to be clinically insignificant across various simulated organs. The minimal DNA damage at the extravasation site suggests that long-term harm, such as radiation-induced carcinogenesis, is highly unlikely.

Numerical Assessment of MHD Tri-Hybrid Nanoparticles by Tangent Hyperbolic Model with Chemical Reaction: Thermodynamic Analysis

This paper investigates the influence of magneto-tangent hyperbolic nanofluid on the flow of a tri-hybrid nanoliquid consisting of [Formula: see text], and [Formula: see text] particles suspended in [Formula: see text]. The entropy production is encountered in this analysis. The fluid flows over a stretch sheet is considered. In addition, the energy equation also assumes the existence of a uniform heat source or sink and thermal radiation. Furthermore, the concentration equation emphasizes the chemical reaction. The current proposed model yields a set of nonlinear governing equations. The modeled formulation is transformed into a dimensionless system through the application of a suitable alteration. The complex nonlinear equation system was solved using the bvp4c through numerical methods. The main motive of this exploration is to emphasize the rate of heat and mass transfer in a flow of [Formula: see text], and [Formula: see text]-based hybrid nanofluid across a stretch sheet. The graphical study illustrates that Weissenberg number and magnetic field enhancement result in decreasing the velocity. But thermal layer, entropy production, and Bejan number are enhanced with larger values of Weissenberg number and magnetic field. This study focuses on different profiles with various flow parameters. Furthermore, we have compared the tri-hybrid nanofluid with the hybrid and mono nanofluid in all the figures and tabular format. Additionally, we have compared tri-hybrid, hybrid, and mono nanofluid using graphs for velocity, temperature, concentration, entropy production, and Bejan number.

Reduction of speckle effect using galvanometer scanners in a laser-based uniform source for radiance responsivity measurement

Narrow linewidth lasers play an important role in high-spectral and high-precision radiometric calibration. In this paper, a standard uniform light source for radiometric calibration of imaging detectors and devices is designed and realized based on narrow linewidth laser and intergrating sphere. Because the speckle effect caused by laser has a great influence on the radiance transfer, galvanometer scanners were employed to reduce the speckle effect. CCD method was used to measure the nonuniformity of the middle row/column of the integrating sphere exit, and nonuniformity reduced from 2.6 % to 0.72 % when the galvanometer scanners were turned on. By superimposing 9 different regions of static speckle image, the non-uniformity is greatly reduced, which is consistent with the experimental results. The output radiance stability of the source is measured with an improvement from 8.4 × 10-5 to 2.7 × 10-5. Finally, the nonuniformity of the source is measured to be 0.15 % by a spot luminance meter.

Onset of double-diffusive convection in a Poiseuille flow with a uniform internal heat source

The linear stability analysis of the onset of double-diffusive convection in a Poiseuille flow system is investigated. In addition, a volumetric uniform internal heat source is taken into account. In this problem, the horizontal fluid channel is bounded by two plates which are isothermal and isosolutal. The governing parameters are thermal Rayleigh number RaT, solutal Rayleigh number Ras, internal heat source parameter RaI, Prandtl number Pr, and Reynolds number Re. The eigenvalue problem arising from the linear perturbed system of equations is solved numerically using the Chebyshev–Tau method coupled with the QZ algorithm. It is found that the positive solutal Rayleigh number Ras destabilizes the system. Furthermore, it is observed that an increase in the Prandtl number Pr stabilizes the system. Additionally, at Ras = −60, the critical values of the thermal Rayleigh number Rac decreases with R=Re cos ϕ up 2; and increases with R beyond R=2.

Onset of Darcy–Brinkman convection with thermal anisotropy in an inclined porous layer

In this article, we study the linear instability and the nonlinear stability (through energy functional) analyses of thermal convection in an inclined Darcy–Brinkman porous layer considering uniformly heated horizontal rigid, impermeable walls from below and above. The effects of a uniform internal heat source and anisotropy in effective thermal diffusivity on heat transfer are also considered. Heating the porous layer from below yields the temperature gradient, influencing the buoyancy and making the convection happen. This temperature gradient also impacts the base state. The basic solution for velocity incorporates both hyperbolic and polynomial functions, significantly increasing the complexity of linear and nonlinear analyses. The Chebyshev-tau method, together with the QZ algorithm, is used to solve the linear and nonlinear perturbed system of equations numerically. The region of subcritical instability is obtained by comparing the linear and nonlinear thresholds for the longitudinal and transverse rolls, respectively. We found that perturbations for longitudinal and transverse rolls do not grow after inclination is more than 30.3° and 31.3°, respectively. It has been noted that in transverse roll scenarios, the flow becomes stabilized when the inclination angle, ϕ, is equal to or exceeds 60°, where ϕ plays a leading role in surpassing the impact of internal heating. However, when the inclination angle is ϕ<60°, then internal heating dominates and destabilizes the flow. For the longitudinal rolls, the internal heating dominates the whole range of ϕ, destabilizing the system. Furthermore, it can be seen that the Darcy number (Da) and the anisotropic thermal diffusivity (ξ) delay the onset of convection.

Novel multi-function setup comprising ultra-bright uniform source for spectral and radiometric calibrations of digital imaging sensors and multiple spectrometric applications

Abstract A new setup is being developed for calibrating CCD/CMOS sensors and cameras, and measuring spectrophotometric quantities in both point-wise and imaging modes. The setup includes a laser-driven light source (LDLS), double-grating monochromator, and an integrating sphere with specific design for two-dimensional (2D) spectrophotometric measurements of complex samples and spectral responsivity calibration of digital imaging sensors and cameras in the visible to near infrared (VIS-NIR) region. The setup can cover a spectral range from 250 nm to 2000 nm with relatively high radiance. The study presents optimization and validation work in the visible through NIR spectral range, up to 1000 nm. Preliminary experiments suggest improved accuracy and lower uncertainties for better metrological performance and sophisticated applications. The developed instrument promises a variety of novel applications while suppressing systematic errors and inaccuracies. The presented measurements results include the validation of 2D spectral reflectance/transmittance measurements in the 360-1000 nm spectral region using selected homogenous standards. Additionally provided are the findings of demonstration measurements for 2D spectral transmittance and the CCD camera’s spectral responsivity within the same spectral range.

Assessment of Conventional X-ray Machine Resolution, Using Designed Phantom

The diagnostics x-ray machine produces electromagnetic radiation used to image the body in case of pathology; therefore, this exposure was justified. But if the exposure parameters were not chosen satisfactorily, imaging has to be repeated where the patient was subjected to a substantial amount of radiation. To determine the spatial resolution in order to find the optimum kV relative to machine type, the phantom is placed on the detector surface, and a uniform source of radiation is placed above the bar phantom, where the focus-to-film distance was 1 m. An image is acquired; the unit was set at 2 mAs and 40 kVp value. In this study, 3 conventional x-ray machines were investigated using point phantom designed by the researcher, which consisted of a variable diameter used to test variable exposure factors. The results showed that the best machine resolution was Toshiba model E7239X (2016) for Modern Medical Center that had a high resolution of 96% at 45 kV for a point of thickness of 1.4 mm.

Electrodeposition of actinides: Optimization of deposition parameters by chronoamperometric studies

To quantify alpha-emitting radionuclides by alpha spectrometry, it is necessary to prepare a thin and uniform alpha source on a suitable substrate. Electrodeposition is the most used electrochemical technique for this purpose. In order to better understand the electrochemical process carried out in the electrodeposition of actinides, in particular the selection of the current densities applied, a chronoamperometric study of the electrodeposition of actinides (Th, U, Pu, Am and Cm), in three different electrolytes (Na2SO4/H2SO4, NH4NO3, NaF) using stainless steel and platinum as cathode and anode, respectively, is presented. The corresponding polarization curves (potential vs. current density), characteristic for each electrolyte and actinide used, were constructed from the chronoamperometric data. The limiting diffusion current as well as the minimum current necessary for the electrodeposition process to take place were determined. To achieve a quantitative electrodeposition of actinides, a balance between OH− production and the thickness of the OH− layer formed near the cathode must be reached. These parameters are controlled by the electrolyte used and the current density applied to the electrochemical system. Actinides were electrodeposited mainly in the form of oxides, according to Raman spectroscopy results.

NiCo layered double hydroxides/carbon dots composites with S-doing for high-performance asymmetric supercapacitors

The pursuit of high-performance electrode materials for supercapacitors has led to the exploration of transition metal layered double hydroxides (LDH), which boast an impressive theoretical specific capacitance. However, their intrinsic limitations, such as poor electronic conductivity and slow diffusion kinetics, have posed significant challenges for their practical implementation. In this work, a NiCo LDH/carbon dots (CDs) composite with S-doping has been meticulously designed to overcome the aforementioned limitations through a synergistic combination of heteroatom doping and carbon incorporation. Utilizing a one-pot hydrothermal method, the composite electrode for the application of asymmetric supercapacitors have been in-situ growth on Ni foam substrate, which not only serves as a robust support but also contributes to the formation of NiCo LDH by providing a uniform Ni source, thereby ensuring strong adhesion and structural integrity. The morphology and microstructures of composites could be finely modulated by adjusting CDs amount. With moderate CDs contents, the optimum electrode S-LDH/CDs-2 exhibits distinctive 3D needle-like spherical morphology, coupled with the ample space for ion diffusion. Consequently, the electrode demonstrates outstanding electrochemical performance, featuring a high areal capacitance of 5157 mF cm−2 at a current density of 2 mA cm−2. Additionally, it exhibits noteworthy rate performance and maintains excellent cycling stability. Integrating the innovative electrode into asymmetric supercapacitors configuration, superior energy density (0.24–0.45 mWh cm−2) and power density (4–20 mW cm−2) as well as good stability have been achieved for the S-LDH/CDs-2//AC device. These results indicate that S-doped NiCo LDH/CDs composite electrode has the desirable potential to be a candidate for energy storage devices.

The impact of ambient noise sources in subsurface models estimated from noise correlation waveforms

SUMMARY Cross-correlations of seismic ambient noise are frequently used to image Earth structure. Usually, tomographic studies assume that noise sources are uniformly distributed and interpret noise correlations as empirical Green’s functions. However, previous research suggests that this assumption can introduce errors in the estimated models, especially when noise correlation waveforms are inverted. In this paper, we investigate changes in subsurface models inferred from noise correlation waveforms depending on whether the noise source distribution is considered to be uniform. To this end, we set up numerical experiments that mimic a tomographic study in Southern California exploiting ambient noise generated in the Pacific Ocean. Our results show that if the distribution of noise sources is deemed uniform instead of being numerically represented in the wave simulations, the misfit of the estimated models increases. In our experiments, the model misfit increase ranges between 5 and 21 per cent, depending on the heterogeneity of the noise source distribution. This indicates that assuming uniform noise sources introduces source-dependent model errors. Since the location of noise sources may change over time, these errors are also time-dependent. In order to mitigate these errors, it is necessary to account for the noise source distribution. The spatial extent to which noise sources must be considered depends on the propagation distance of the ambient noise wavefield. If only sources near the study area are considered, model errors may arise.

Effect of dielectric material on the uniformity of nanosecond pulsed dielectric barrier discharge

Dielectric barrier discharge (DBD) is considered as a promising technique to produce large volume uniform plasma at atmospheric pressure, and the dielectric barrier layer between the electrodes plays a key role in the DBD processes and enhancing discharge uniformity. In this work, the uniformity and discharge characteristics of the nanosecond (ns) pulsed DBD with dielectric barrier layers made of alumina, quartz glass, polycarbonate (PC), and polypropylene (PP) are investigated via discharge image observation, voltage-current waveform measurement and optical emission spectral diagnosis. Through analyzing discharge image by gray value standard deviation method, the discharge uniformity is quantitatively calculated. The effects of the space electric field intensity, the electron density (N e), and the space reactive species on the uniformity are studied with quantifying the gap voltage U g and the discharge current I g, analyzing the recorded optical emission spectra, and simulating the temporal distribution of N e with a one-dimensional fluid model. It is found that as the relative permittivity of the dielectric materials increases, the space electric field intensity is enhanced, which results in a higher N e and electron temperature (T e). Therefore, an appropriate value of space electric field intensity can promote electron avalanches, resulting in uniform and stable plasma by the merging of electron avalanches. However, an excessive value of space electric field intensity leads to the aggregation of space charges and the distortion of the space electric field, which reduce the discharge uniformity. The surface roughness and the surface charge decay are measured to explain the influences of the surface properties and the second electron emission on the discharge uniformity. The results in this work give a comprehensive understanding of the effect of the dielectric materials on the DBD uniformity, and contribute to the selection of dielectric materials for DBD reactor and the realization of atmospheric pressure uniform, stable, and reactive plasma sources.

Mixed planting of subtropical Chinese fir in South China improves microbial carbon source metabolism and functional diversity through the accumulation of nutrients from soil aggregates.

Soil microbial functional traits are key indicators of soil microbial ecological traits; however, how mixing patterns of Chinese fir and broadleaved trees drive soil microbial functional trait variation at the aggregate scale and how soil microbial functional traits are linked to soil fertility factors have largely not been determined. In this study, soil from the 0-20 cm depths in three Chinese fir plantations was collected, and the soil samples were separated into >2 mm (large macro-aggregate), 0.25-2 mm (macro-aggregate) and <0.25 mm (micro-aggregate) by complying with an optimal moisture sieving procedure. The metabolic activities, functional diversity and different carbon sources utilization characteristics of the soil microorganisms were determined by the Biolog Eco microplate method. In all Chinese fir plantations, micro-aggregates (<0.25 mm) consistently exhibited the highest levels of microbial metabolic activity, a more uniform carbon source utilisation capacity, and the highest microbial diversity. Micro-aggregates also showed elevated levels of soil organic carbon (OC), total nitrogen (TN), total phosphorus (TP), and higher ratios of C/N and C/P compared to large macro-aggregates and macro-aggregates, indicating that micro-aggregates contain more resources available to soil microorganisms. Soil OC, TN, and TP content were enhanced by integration with Michelia macclurei, suggesting that this combination promotes relatively favourable soil conditions for microbial growth and multiplication. This, in turn, promotes microbial metabolic activity. Furthermore, redundancy and correlation analyses showed that soil OC, TN, and TP were identified as principal determinants of soil microbial functional properties in Chinese fir plantations. In summary, mixed cultivation and aggregate size influenced microbial functional properties via soil nutrient alterations. Consequently, adopting a mixed cultivation approach of Chinese fir and broadleaved trees is advocated in the subtropical regions of Guangxi. Employing a diversity of tree species, including M. macclurei, is recommended for optimal soil quality preservation.

Thermal transport characteristics of fluid-particle suspension in a vertical uniform tube: A computational study on Rabinowitsch fluid with uniform heat source

Problem statement The thermal transport of fluid-particle suspension in Rabinowitsch fluid is discussed theoretically in a vertical uniform tube under the consideration of a uniform heat source. Methodology The fluid and particle phase models are used to develop the mathematical model in the form of partial differential equations which are solved through the symbolic software MATHEMATICA version 12.0 and present the exact solution of temperature distribution, velocity of fluid and particle phases, wall shear stress, pressure gradient, pressure rise, and stream function, etc. Computational results and findings The volume fraction density of the particles slows down the motion of the fluid particles. The velocity of Newtonian fluid is maximum as compared to pseudo-plastic and Dilatant fluids. The fluid phase velocity is superior to particle phase velocity distribution for all pertinent parameters of the analysis. The pressure rise increases in the case of Newtonian and pseudo plastic fluid and decreases in Dilatant fluid. The trapping phenomena are strongly associated with the volume fraction density of the particle. The shear stress shows a decreasing trend against the volume fraction density of the particles, Grashoff number, and heat source parameter. Special case The current fluid model (Rabinowitsch fluid) can be reduced in Newtonian, pseudo plastic, and Dilatant fluid for taking κ → 0 , κ < 0 , and κ > 0 , respectively. Applications The current analysis can be useful in biomedical engineering to observe the blood supply through the arteries, the removal of kidney stones, and also the passage of urine to the bladder from the ureter. Originality The present research is original and has not been published before.

Edge conditional node update graph neural network for multivariate time series anomaly detection

With the rapid advancement in cyber-physical systems, the increasing number of sensors has significantly complicated manual monitoring of system states. Consequently, graph-based time series anomaly detection methods have gained attention due to their ability to explicitly represent relationships between sensors. However, these methods often apply a uniform source node representation across all connected target nodes, even when updating different target node representations. Moreover, the graph attention mechanism, commonly used to infer unknown graph structures, could constrain the diversity of source node representations. In this paper, we introduce the Edge Conditional Node Update Graph Neural Network (ECNU-GNN). Our model, equipped with an edge conditional node update module, dynamically transforms source node representations based on connected edges to represent target nodes aptly. We validate performance on three real-world datasets: SWaT, WADI, and PSM. Our model demonstrates 5.4%, 12.4%, and 6.0% higher performance, respectively, compared to baseline models with best F1 scores. Our code is available at https://github.com/hayoung-jo/ECNU-GNN.

Deciphering ore genesis with oxygen and sulfur isotope signatures: A case study from the Singhbhum Shear Zone, Eastern India

The importance of light-stable isotopes and their mass-dependent fractionations in understanding past geological processes is enormous. The present research delivers precise, high-resolution, in-situ oxygen (18/16O) and triple sulfur (32/33/34S) isotope ratios from quartz and sulfide minerals found in the CuAu Kendadih deposit located along the Mesoproterozoic (∼1.6 Ga) Singhbhum Shear Zone (SSZ) in eastern India. Oxygen and sulfur isotope analyses were carried out on quartz and pyrite-chalcopyrite pairs that are in textural equilibrium, using the most advanced Large Geometry-Secondary Ion Mass Spectrometer (LG-SIMS; CAMECA IMS-1300HR3). The results show restricted ranges for δ18Oquartz (+6 to +7.7‰; average: 6.9 ± 0.9‰, n = 50) and δ34Schalcopyrite-pyrite (+11.4 to +11.9‰; average: 11.79 ± 0.2‰, n = 62). This isotopic homogeneity suggests a single, uniform fluid source for the ore-forming metals. The combined oxygen, sulfur isotope ratios, and fluid inclusion data are consistent with a hydrothermal fluid derived from an “I-type” granitic melt. This study incorporates existing fluid inclusion, stable, and radiogenic isotope data from temporally similar deposits within the shear zone, reevaluating their implications in light of the new findings. It proposes that, around 1.6 billion years ago, underplating the Singhbhum Craton by the Dalma Plume resulted in the remelting of the lower crust. This remelting is attributed to the plume's introduction of a significantly elevated thermal perturbation. The process is hypothesized to have led to the generation of second-order granitic melts. Upon emplacement in the lower crust, these granitic melts became the potential source for essential metals, ligands, and hydrothermal fluids, contributing to mineralization within the deep-seated Singhbhum Shear Zone. This research attempts to comprehensively describe the “source-to-sink” ore genesis model by proposing potential magma chamber processes that concentrate metals and ligands at the roof zone, followed by the separation of metal-rich hydrothermal fluids, fluid-rock interaction, and the physicochemical conditions governing the deposition of the extensive polymetallic deposit. This work offers novel insights into the Mesoproterozoic metallogenesis along the Singhbhum Shear Zone, challenging existing paradigms that favored evaporite or seawater brine sources. Furthermore, it sheds light on the Mesoproterozoic sub-crustal processes beneath the Indian Craton in this region.

Thermocapillary migration of a compound drop in an arbitrary viscous flow

The thermocapillary migration of a concentric compound drop in an arbitrary viscous flow under the consideration of negligible Reynolds number is investigated. The thermocapillary effect refers to the migration of a drop under the influence of a temperature gradient. The thermal and hydrodynamic problems are examined. The thermal field is governed by the heat conduction equation whereas the hydrodynamic fluid velocities are governed by the linearized Navier–Stokes equations. Presence of temperature gradient results in variation of the interfacial tension which is assumed to depend on temperature linearly. Variation of interfacial gradient leads to the coupling of the hydrodynamic problem with the thermal problem through the boundary condition. A complete general solution of Stokes equations is utilized to obtain closed-form expressions for the velocity vector and pressure. The hydrodynamic forces acting on the compound drop are obtained and expressed in terms of Fax́en’s law. Some important asymptotic limiting cases of hydrodynamic drag are also derived. The hydrodynamic drag for cases of uniform flow, shear flow, and heat source with the known ambient flow are derived and it is found that in the case of shear flow, the hydrodynamic drag is contributed only by the thermal component and the shear flow has no effect on it. The obtained results for drag and torque in the limiting cases are in agreement with the existing results in the literature. Furthermore, the migration velocity of the compound drop is obtained by equating the hydrodynamic drag force to zero. The results obtained for migration velocity are explained with the aid of graphs. The migration velocity is found to be a monotonic function of the Marangoni number and the radius of the innermost drop.

Improved slip mechanism and convective heat impact for ternary nanofluidic flowing past a riga surface

This study of electro-magneto-hydrodynamics has great significance due to its numerous applications like chromatography, fluid pumping, micro coolers and fluid stirring thermal reactors and flow regulation in fluidics systems. Subject to upper functions on electrical magnetic field, the consequences of electromagnetic initiation into ternary nanofluids flow through the Riga plate were noticed. Furthermore, this ternary hybrid nanofluid flow was based on the effect on slip condition, uniform heat source, convective energy and thermal radiation. The ternary hybrid nanofluid was built from the scattering of silver, copper and copper oxide nanoparticles by this base fluid blood. This phenomenon had been formed by the model of the system in partial differential equations; it was made easy in the dimensionless nonlinear structure of ordinary differential equations by employing comparison substitutions. This result on the acquired set of the differential equations was simulated over the bvp4c method. It has been discovered that the ternary hybrid nanofluid velocity is essentially lower along the differing numbers of permeable media, although it amplifies along the upshot on the Hartmann number. Moreover, an enhanced heat transport rate of up to 14% was marked for the triple nanoparticle nanofluid by relating it to another nanofluid and establishing an excellent behavior on triple nanoparticle nanofluids.

Exceptional load-bearing capability of Al FPCB/Cu FPCB lap joints using instantaneous laser-based large area facial soldering: Experimental and numerical investigations

This study introduces a novel method for integrating aluminum flexible printed circuit boards (FPCBs) and copper FPCBs into battery management systems (BMS) using and instantaneous large area facial laser source soldering. Achieving a robust bonding strength of 65 MPa involved applying 600 W of laser power for 2 s, enhancing atom diffusion and promoting intermetallic compound (IMC) growth. Finite Element Method (FEM) simulations revealed variations in heat transfer between Al and Cu, affecting IMC thickness at interfaces. Formation of the (Cu, Ni)3Sn4 phase within solder, and variations in laser output significantly influenced solder joint orientation and Al electrode nucleation. Excessive laser power (>800 W) caused critical damage, such as delamination at the Al-PI interface, altering fracture modes and bonding strength. Furthermore, with a detailed examination of the laser soldering phenomenon through both experimental and numerical investigations, this study provides a thorough understanding of the different soldering mechanisms in conventional reflow soldering compared to instantaneous uniform large-area heat source laser soldering. These insights provide new design and material considerations to replace the conventional wiring harness with Al/Cu FPCB lap joints which optimize the circuitry and reducing BMS volume.

Enhancing the degrees of freedom of topology optimization via variable-porosity metal foams: Design of heat conduction paths in a volume-to-point problem

Multi-material topology optimization determines the optimal distribution of different materials within a design domain in order to achieve specific performance goals. This work takes advantage of such technique to enhance the thermal performance of a benchmark heat conduction problem. The aim is to investigate the impact of enhancing the degrees of freedom introducing different materials, i.e., variable-porosity metal foams in addition to the high-conductivity solid, in the design of heat conduction paths under a constant weight constraint. The study leverages a well-established case study – volume-to-point problem – in the field of thermal management, ensuring a consistent basis for comparison. It consists of a square domain with a uniform heat source and a Dirichlet condition at a point on the boundary. Interpolation functions – ordered solid isotropic material with penalization (SIMP) type – allow the properties – in this case thermal conductivity – of materials to be correctly assigned. The distinction between materials is made by means of different thresholds on the projection function. By varying the foam porosity, we investigate the trade-offs between weight and heat dissipation efficiency. The objective is to find the ideal combination of materials that maximizes heat transfer – minimizing the average domain temperature – while conforming to weight constraints. Findings reveal that multi-material topology optimization – when applied to heat conduction problems – can outperform other design approaches, such as the growth-based algorithm, the evolved constructal tree, and the classical topology optimization (with one solid material), thereby paving the ground to innovative heat sink designs in weight-constrained environments.