Temperature Curves Research Articles

Evolution of heat transfer in MHD nanofluid flow over a porous plate: Insights into the influences of slip and variable viscosity

Temperature-dependent viscosity finds application in various industries such as oil and gas, polymer processing, and food manufacturing. Understanding how viscosity changes with temperature is critical for optimizing processes like drilling operations, polymer molding, and food product consistency. Additionally, it plays a vital role in controlling flow behavior, ensuring efficient heat transfer, and maintaining product quality across different temperature conditions. The exploration of temperature-dependent viscosity in Powell-Eyring nanofluid models represents a novel and unexplored avenue in the field. The study’s novelty is underscored by its comprehensive investigation into a range of factors, such as surface suction, thermal radiation, slip velocity effects, and nanoparticle concentration slip, all integrated within the Powell-Eyring nanofluid model. Moreover, the adoption of bvp4c as a numerical tool further emphasizes the research’s unique contributions. The curves of temperature, concentration, and velocity as a consequence of changes in physical parameters are discussed. Increasing the value of the suction parameter promotes heat transfer but slows the velocity of the nanofluid. The injection of a magnetic field is responsible for compensating for the suction rate. An improvement in the concentration of nanoparticles and temperature is observed as a result of an increase in the slip rate. It is evident that both nanoparticle concentration and temperature rise significantly when Bi, the Biot number, is increased. In the boundary layer, a decrease in velocity is observed as a consequence of an increase in velocity slip, porosity, and magnetic field parameters.

Thermo-convection driven Sodium Alginate-based Darcy–Forchheimer EMHD Williamson hybrid nanofluid flow with varying thermal distribution

A computational investigation is furnished to explore the responses of a Darcy–Forchheimer EMHD Williamson flow of a Sodium Alginate [Formula: see text]-based Ag-Al2O3 hybrid nanofluid passing over a vertically exponentially stretching cylinder emerged through a porous region. The prime focus of this research is to encompass the inclusion of nonlinear variations in heat distribution, Newtonian boundary heating (NBH) effects, and the influence of thermo-convection alongside suction effects. Key parameters, including thermal buoyancy, Darcy porous medium effects, heat source/sink effects, Biot number, variable thermal index, and thermal convection factor, are comprehensively analyzed as these combining factors can play a crucial role in optimizing the efficacy of several systems such as heat exchanger, material processing and geothermal system that involve the concept of thermo-transportation mechanism. The physical flow dynamics are modeled, employing suitable similarity transformations, and subsequently translated into a dimensionless form. The ensuing collection of modified nonlinear ordinary differential equations is solved by employing the Bvp4c solver bundled into the MATLAB program. Several parameters are scrutinized through graphical presentations to elucidate their impacts on the velocity curve, temperature curve, skin friction coefficient, and Nusselt index. It is worth mentioning that the heat distribution profile significantly escalated for the rising values of several factors such as electric field parameter, varying thermal index, Biot number and shape factor, but the reverse is the pattern with suction and thermo-convection effect. Also, the thermal transportation rate at the proximity of the vertical cylindrical wall appears to exhibit an increment of about an average of 47% in SA-based Williamson hybrid nanofluid compared to Williamson fluid for thermo-convective effect, NBH, and thermal buoyancy. Furthermore, the proximate shear stress rate appears to be amplified by approximately 39% in Williamson hybrid nanofluid when contrasted with Williamson fluid for electric field parameter and thermo-convection effect alongside the raised Darcy–Forchheimer factor.

Simulating martensitic transformation in NiTi-Hf – effects of alloy composition and aging treatment

In the NiTi-Hf alloy system, coherent H-phase (orthorhombic) nanoprecipitates have been shown to have strong impact on the B2 (cubic) to B19’ (monoclinic) martensitic transformation (MT) and the corresponding stress-strain behavior. Two typical martensite-precipitate microstructures have been observed: intra-martensite precipitates (IMP) and inter-precipitate martensites (IPM). In the former, high density small H-phase nanoprecipitates are embedded in individual domains of different variants of the B19’ martensite that form a herringbone structure, while in the latter, finer twinning B19’ martensites are confined in between larger H-phase nanoprecipitates. In this study we investigate the mechanisms underlying the formation of these two distinct microstructures through computer simulations using the phase field method. In particular, we study temperature- and stress-induced MTs in the presence of H-phase nanoprecipitates, concentration variations and stress field in the B2 matrix created by the precipitation reaction, and the corresponding thermal and stress hystereses and superelasticity for different alloy compositions and aging treatments. The simulation results indicate that densely populated nanoprecipitates 7∼20 nm in length and 3∼8 nm in width lack the strength to impede the growth, coalescence and coarsening of martensitic domains, resulting in the formation of IMP. In contrast, plate-like nanoprecipitates with diameters of ∼100 nm and thickness of ∼20 nm effectively hinder the growth, coalescence and coarsening of martensitic domains, giving rise to IPM. The IPM microstructure is accompanied by an almost linear volume fraction vs. temperature curve with less than 1 °C hysteresis during thermal cycling and a slim stress-strain hysteresis as compared to that of the IMP microstructure. Therefore, thoughtful choices in alloy composition and aging treatment enable the attainment of distinctly varied precipitate and martensitic microstructures, each characterized by unique pseudoelastic or superelastic properties.

Soil Hydrothermal Dynamics in the Hengduan Mountains of Southeast Tibet and Associated Influencing Factors

Soil water and soil temperature are important ecological factors and driving forces for ecosystem restoration and sustainable development, possessing great significance for climate modeling and prediction. The Hengduan Mountains in southeastern Tibet, China, are located in a climate-change-sensitive area, and the study of soil hydrothermal dynamics in this area is of great significance for local and global climatic change and water resource utilization. This study, based on the soil hydrothermal and meteorological data of the Hengduan Mountain area in Southeast Tibet, analyzes the dynamic change patterns of soil hydrothermal and meteorological factors and explores their influencing relationships. It was found that the dynamic change in soil water content affected by precipitation was “bimodal” type. Among the meteorological factors, soil water content has the strongest correlation with relative humidity. The intra-annual variation curve of soil temperature is similar to that of the atmospheric temperature, showing a “unimodal” type, and has the highest correlation with atmospheric temperature. Specifically, it takes 70 mm and 170 mm of precipitation to change the soil water content and soil temperature at the 150 cm depth. For every 20 °C change in atmospheric temperature, soil temperature above 150 cm changes by an average of 7.2 °C.

SIMULATION AND EX VIVO EXPERIMENTAL STUDY OF MICROWAVE ABLATION OF ADRENAL ADENOMA BY COAXIAL SLOT ANTENNA

Object: Microwave ablation has been widely used in tumor treatment, and the antenna is a critical component of microwave ablation. We aimed to evaluate a single-slot antenna to generate a small volume ablation zone ([Formula: see text] in adrenal tissue. Methods: A three-dimensional numerical model of the adrenal tissue was built and solved by the Finite Element Method. In the simulation model, the slot antenna was placed between the adrenal gland and fat, and the microwave ablation power and time were adjusted to obtain the target ablation zone. In ex vivo experiments, the length and width of the ablation zone were measured, and the significance of ablation parameters on it was determined using a multi-factorial analysis of variance method. The temperature versus time curves at 3[Formula: see text]mm and 7[Formula: see text]mm from the antenna were plotted to validate the simulation. Results: The simulation results showed that the combination of microwave ablation parameter settings 30[Formula: see text]W/300[Formula: see text]s, 40[Formula: see text]W/180[Formula: see text]s, and 40[Formula: see text]W/300[Formula: see text]s could create ablation zones in the adrenal tissue volumes of [Formula: see text] and [Formula: see text], respectively, with minimal damage (less than [Formula: see text] to the surrounding fat tissue. Both power and heating time significantly affected the length and width of the ablation zone. The temperature rise curves obtained in the simulation and ex vivo experiments were in good agreement. Conclusion: This work shows that utilizing a slot antenna can produce a small volume ablation zone in adrenal tissue for microwave ablation of benign adrenal adenomas.

Assessment of hydraulic and thermal properties of the Antarctic active layer: Insights from laboratory column experiments and inverse modeling

To better understand the changes in the hydrologic cycle caused by global warming in Antarctica, it is crucial to improve our understanding of the groundwater flow system, which has received less attention despite its significance. Both hydraulic and thermal properties of the active layer, through which groundwater can flow during thawing seasons, are essential to quantify the groundwater flow system. However, there has been insufficient information on the Antarctic active layer. The goal of this study was to estimate the hydraulic and thermal properties of Antarctic soils through laboratory column experiments and inverse modeling. The column experiments were conducted with sediments collected from two lakes in the Barton Peninsula, Antarctica. A sand column was also operated for comparison. Inverse modeling using HydroGeoSphere (HGS) combined with Parameter ESTimation (PEST) was performed with data collected from the column experiments, including permeameter tests, saturation-drain tests, and freeze-thaw tests. Hydraulic parameters (i.e., Ks, θs, Swr, α, β, and Ss) and thermal diffusivity (D) of the soils were derived from water retention curves and temperature curves with depth, respectively. The hydraulic properties of the Antarctic soil samples, estimated through inverse modeling, were 1.6 × 10−5–3.4 × 10−4 cm s−1 for Ks, 0.37–0.42 for θs, 6.62 × 10−3–1.05 × 10−2 for Swr, 0.53–0.58 cm−1 for α, 5.75–7.96 for β, and 5.11 × 10−5–9.02 × 10−5 cm−1 for Ss. The thermal diffusivities for the soils were estimated to be 0.65–4.64 cm2 min−1. The soil hydraulic and thermal properties reflected the physical and ecological characteristics of their lake environments. The results of this study can provide a basis for groundwater-surface water interaction in polar regions, which is governed by variably-saturated flow and freeze-thaw processes.

Interfacial thermal resistance between mechanically exfoliated nm-thick MoS2 and silicon from −60 °C to 50 °C based on ns-ET Raman technique

In the miniaturization and integration development of micro-devices, the large thermal contact resistance significantly affects the overall performance of micro-devices, which is influenced by both interfacial contact condition and material properties. However, the temperature dependence of interfacial thermal resistance of realistic materials remains unclear. In this work, the interfacial thermal resistance between nm-thick MoS2 nanosheets and Si substrate is measured by using the ns energy transport state-resolved Raman (ns ET-Raman) technique. By comparing the experimental data with finite difference numerical simulation, the real value of the interfacial thermal resistance is determined. By changing the ambient temperature from -60 °C to 50 °C, the interfacial thermal resistance against temperature curve is obtained. As the environmental temperature deviates from room temperature, a large increasement of the interfacial thermal resistance can be observed. As temperature goes back to room temperature, the unreversible interfacial thermal resistance indicates that the large thermal expansion mismatch deteriorates the contact situation. In the last, the interfacial thermal resistance evolution under varying environmental temperatures from both experiments and modeling results in literatures are compared and discussed to illustrate the effect of different interface formation methods. For epitaxial and CVD grown materials, the interfacial thermal resistance generally reduces with raising ambient temperature. While for mechanically exfoliated samples, the effect of thermal expansion mismatch and the resulting gaps dominate the interfacial thermal resistance, which leads to non-monotonous temperature dependency with a valley located at room temperature.

Cross-diffusion and heat transfer effects on peristaltic flow of Reiner-Philippoff nanofluid with pseudoplastic and dilatant fluids over tapered channel: Multiple solutions and stability analysis

Peristaltic flow is used in many scientific and technological fields, including biology and medical technology. The goal of this research is to investigate the peristaltic behavior in an asymmetric non-uniform (tapering) channel using a Reiner-Philippoff fluid model (RPFM)-based nanofluid under the influence of dilatant and pseudoplastic fluid behavior. The Buongiorno nanofluid model (BNFM) is considered to investigate heat mass transportation. The channel is transformed from static reference to movement frame using the subsequent set of modifications, and the dynamic frame is transformed back to dimensionless form using the dimensionless parameters. The fundamental equations have been streamlined due to the long wavelength and small Reynolds number. Novelty of the current study is to examine the stability of numerical framework for RPFM-based nanofluid with dilatant and pseudoplastic fluid behavior. The boundary value problem fourth order code (bvp4c) technique is used to obtain the numerical results. With the use of graphs and tables, the physical elements that influence fluid dynamics are further explained. Stability evaluation has been performed mathematically and graphically. The most reliable solution is shown by the lowest positive eigenvalues, while the unreliable solution is indicated by the negative eigenvalues. It has been proven that changing the Reiner-Philippoff fluid (RPF) factor results in a fluid's velocity changing from dilatant to Newtonian as well as from Newtonian to pseudoplastic. According to the findings, the temperature curves rise as thermophoretic components and Brownian motion increase while decreasing as the Prandtl number increases. A brief theoretical and graphical analysis of each important parameter's effects on the flow dynamics is also carried out.

Modelling the Charpy Impact Ductile-Brittle Transition of a Ship Plate Steel with CAFE Modelling

In the present work, a cellular automata finite element model (CAFE) was developed to model the ductile-brittle transition of a Grade A ship plate steel. Therefore, ductile and brittle cellular automata (CA) arrays of cells were created in the model to integrate material data at microstructural level, along with the ductile and brittle fracture processes. Microstructural data was analysed with Weibull distributions and incorporated in CAFE model using random number generators, along with ductile and brittle fracture parameters. Ductile fracture was modelled with Rousselier damage model; hence damage model parameters were calibrated with experimental data. Brittle fracture was modelled with Beremin model, and four different cleavage particles, found in a Grade A ship plate steel, were incorporated in CAFE model in order to model a competition of particles nucleating microcracks of critical size in the damage regions of Impact Charpy tests and four-point double-notch bend tests performed at low temperature. The mechanical properties the plate steel was measured in the transition region and incorporated in CAFE model, along with ductile-brittle transition rules. The present CAFE model was able to simulate distributions of microcracks in the notch region of four-point double-notch bend models (in the transition region), which correlated with experimental data. CAFE model was also able to simulate microvoids in the notch region of Charpy specimens along with the load-displacement Charpy curve for room test temperature, with very good agreement with experimental data. Once CAFE model was validated at micro and structural level, it was applied to model the typical scatter of impact Charpy energy values in the transition region of Grade A ship plate steel with good agreement with the measured ductile-brittle transition curved of the plate steel. Keywords: cellular automata, finite element modelling, ductile-brittle transition, damage modelling.

Transient state analysis of rehabilitated RC beams using finite element modelling and prediction using an artificial neural network

The present research develops and verifies a simpler numerical approach for analyzing the thermal transient state of rehabilitated concrete beams reinforced with various types of FRP (fiber-reinforced polymer) subjected to high temperatures and specifically built as under-reinforced concrete beams. This approach offers a straightforward, efficient, and exact instrument for numerical analysis. The proposed analytical technique has been validated by load-displacement curves and cross-section temperature data, indicating its dependability and practicality. Subsequently, the validated approach was used to examine the impact of significant variables on the outcome and restoration of FRP-reinforced concrete beams at high temperatures. The methodology gives the Comparing conventional and CFRP, GFRP, AFRP reinforced beams using beam, truss, and shell elements. Thermal and UDL loads were applied, mesh at 25 mm × 25 mm. Transient analysis contrasts performance via displacement and temperature. The temperature versus displacement curve shows the FRP comparisons. Identifying the critical temperature before failure is crucial, emphasizing the curve’s significance in assessing structural performance and potential failure points. Nodal temperatures ranged 939 °C–963 °C (rehabilitated) versus 958 °C (conventional). 200 °C difference affects thermal boundary conditions for structural analysis and Conventional peaks at 320 °C, while AFRP, GFRP, and CFRP reach 358 °C, 385 °C, and 390 °C respectively. CFRP lasts 2400 min. Neural network models demonstrate effective generalizability, enabling satisfactory predictions of RC beam rehabilitation with CFRP laminates within the study’s parameter range.

Alumina solubility in periclase determined to lower mantle conditions and implications for ferropericlase inclusions in diamonds

A series of high-pressure multi-anvil experiments were conducted in the MgO-Al2O3 system between 15 and 50 GPa and at temperatures up to 2623 K, to determine the solubility of Al2O3 in periclase in the stability fields of coexisting spinel, corundum, the Mg2Al2O5 modified ludwigite phase, the MgAl2O4 calcium ferrite phase, and the MgAl2O4 calcium titanate phase. The Al2O3 solubility in periclase is strongly temperature-dependent over the conditions investigated. Conversely, periclase Al2O3 solubility exhibits a negative relationship with pressure. Experiments with up to 40 mol.% FeO in ferropericlase show Al2O3 solubilities that are near identical to those of periclase, within experimental uncertainties. A simple thermodynamic model incorporating significant literature on ambient pressure measurements is able to describe periclase Al2O3 solubility up to 40 GPa. This model is used to investigate the Al2O3 contents of ferropericlase inclusions observed in natural diamonds, which vary up to 0.35 mol. %. Pressure–temperature curves along which particular inclusions formed can be produced if equilibrium can be assumed with Al-bearing minerals found in the same diamond. Alternatively, the maximum possible Al2O3 content in ferropericlase can be determined for a certain pressure–temperature profile and inclusions with Al2O3 contents that exceed this curve can be excluded from those conditions. To obtain such solubility curves, calculations are performed for periclase coexisting with the Al-rich phases spinel, garnet, bridgmanite and the MgAl2O4 calcium ferrite phase. The calculations indicate that periclase, and by inference ferropericlase, Al2O3-contents cannot be greater than 0.5 mol.% under present day adiabatic mantle temperatures and go through a minimum at mantle transition zone conditions. This excludes a number of Al-rich ferropericlase inclusions found in natural diamonds from being formed in the transition zone, unless temperatures were super-adiabatic. This subset of inclusions likely formed either at the base of the upper mantle or the top of the lower mantle, but must have formed at near adiabatic temperatures. The majority of ferropericlase inclusions have Al2O3 contents that would be consistent with formation in the transition zone at near slab temperatures, but could still have been formed at higher temperatures if Al2O3 activities were low.

Curing curve prediction using genetic algorithm optimized back propagation neural network

Thermoset composites constructed with monolithic moulding can significantly reduce the number of parts and connectors, improve the reliability of the composite structure, and reduce production costs. For such composite components, the degree-of-cure (DoC) curve is normally considered to evaluate the curing process, so that the curing process-induced deformation and residual stress can meet the manufacturing requirements. In this paper, a method is proposed to predict the DoC curve based on the neural network. First, the DoC curves for AS4/3501-6 composite structures were obtained from ABAQUS and HETVAL subroutine, and the results were verified by published values. Next, the curves of temperature over time and DoC over time were generated to train the neural network. Finally, the back propagation (BP) neural network is optimized using the genetic algorithm (GA), and the DoC curve prediction model is created. The results demonstrate that, with a maximum error of 3.24%, the simulated curves essentially correspond with published values. Evaluation and validation analyses show that the prediction of the DoC curve using the GA-BP neural network yields high computational efficiency and accuracy.

Electro-Thermal Simulation and Reliability of a Ball Grid Array

Abstract The influence of electric current flow and electrically induced Joule heat on thermal stress for weld joint cracks at both interfaces is still not fully comprehended. This article investigates the effect of subjecting the ball grid array package to a cyclic current input. Current density, Joule effect, and temperature curves are examined.

Research on the mechanism of thermal-mechanical coupling effects of hypersonic aircraft rudder structure

Hypersonic aircraft have achieved rapid development in the past decade, with flight speeds exceeding 5 Ma, posing a very severe aerodynamic and thermal environment for rudder structure. Especially for metal rudder wings, the extremely high temperature and temperature gradient makes the structural thermal response problem very prominent and complex. This article focuses on the study of the thermo-mechanical coupling response of the metal rudder wings of hypersonic aircraft in flight thermal environments. By simplifying the aerodynamic load and aerodynamic thermal environment under flight time sequence, a finite element model based on thermo-mechanical sequence coupling is established. The temperature, thermal stress, and deformation response curves of key parts are extracted, and the thermo-mechanical coupling response law of the rudder structure is explored. Based on the mechanical properties of structural materials at different temperatures, the corresponding relationship between stress and residual strength of key parts during flight time is obtained, and the safety factor of key parts of the structure is given.

Nucleation study of xylitol as PCM in two different crystallization systems: a rheometer and a lab-scale prototype

Sugar alcohols are promising materials for latent heat-based thermal energy systems. Xylitol stands out among them for its high phase change enthalpy and density. However, xylitol, as well as other sugar alcohols, show undercooling and low crystallization rates, which hinder it potential as a phase change material. This work studies the effect of the seeding and shearing technique on crystallization, in addition to the effect of the operation conditions, such as temperature or shear. To do so, two systems are studied: a rheometer and a stirred tank. Induction times are then calculated from temperature and viscosity curves, and a crystallization model is used to study the influence of operating conditions in crystallization.

Design, development and commissioning of the control system for the cryogenic distribution system at ESS

The cryogenic distribution system (CDS) at the European Spallation Source (ESS) connects the refrigeration plant with the linear accelerator, consisting in 13 spoke and 30 elliptical cryomodules that are cooled at 2K via multi-transfer lines, individual valveboxes for every cryomodule and an endbox. The designed control system monitors and controls the cooling helium flow through the CDS. The controls architecture for the CDS is based on one Programmable Logic Controller (PLC) per valvebox and another one for the endbox, which are integrated into EPICS through the Controls Network and takes care of the process functions, making it a total of 44 PLCs. This type of integration allows for the remote operation of the CDS from the control room and the necessary interaction of the control system with other related systems and EPICS services like archiving, alarms and save-and-restore. Pre-commissioning activities like loop checks, temperature curve validation, pressure sensor calibration and valve initialization started in summer 2022. Eventually, the system was ready for commissioning and a first cooldown was performed in December 2022. The paper describes the design, development and commissioning of the control system and diverse challenges during the deployment and commissioning activities. Future activities are discussed including the implementation of a sequencer for automatic cooldown and warmup, integration with the cryomodule controls and a master PLC to handle the helium management.

Commissioning of the cryogenic distribution system of the ESS superconducting linac

The European Spallation Source (ESS) is a neutron-scattering facility being built with extensive international collaboration in Lund, Sweden. An essential part of the project is the linear 2.0 GeV proton accelerator. Its superconducting part is designed to comprise 13 spoke and 30 elliptical cryomodules that are cooled at 2K. The cryogenic distribution system (CDS) connects the refrigeration plant with the cryomodules via multi-transfer lines, individual valveboxes for every cryomodule and an endbox. It is designed, manufactured and installed under the responsibility of two ESS in-kind partners. The CDS for the spoke cryomodules (CDS-SL) is supplied by IJCLab, France, the CDS for the elliptical cryomodules (CDS-EL) is supplied by WUST, Poland. Pre-commissioning, commissioning and operation is done by ESS whereby IFJ PAN contributed with valuable advice. Pre-commissioning activities like loop checks, temperature curve validation, pressure sensor calibration or valve initialization and leak tightness tests followed after mechanical or electrical completion of the respective CDS parts and started in summer 2022. Eventually, the system was ready for commissioning and a first cooldown was performed in December 2022. Goal of this commissioning was to acceptance test and check off the system before pilot cryomodule installation in the tunnel started in March 2023. The paper describes diverse challenges regarding TAO and cryo operation. Test results, lessons learnt, and required modifications are discussed as well as preliminary results of retesting and an outlook.

Synthesis, Surface Modification and Magnetic Properties Analysis of Heat-Generating Cobalt-Substituted Magnetite Nanoparticles.

Here, we present the results of the synthesis, surface modification, and properties analysis of magnetite-based nanoparticles, specifically Co0.047Fe2.953O4 (S1) and Co0.086Fe2.914O4 (S2). These nanoparticles were synthesized using the co-precipitation method at 80 °C for 2 h. They exhibit a single-phase nature and crystallize in a spinel-type structure (space group Fd3¯m). Transmission electron microscopy analysis reveals that the particles are quasi-spherical in shape and approximately 11 nm in size. An observed increase in saturation magnetization, coercivity, remanence, and blocking temperature in S2 compared to S1 can be attributed to an increase in magnetocrystalline anisotropy due to the incorporation of Co ions in the crystal lattice of the parent compound (Fe3O4). The heating efficiency of the samples was determined by fitting the Box-Lucas equation to the acquired temperature curves. The calculated Specific Loss Power (SLP) values were 46 W/g and 23 W/g (under HAC = 200 Oe and f = 252 kHz) for S1 and S2, respectively. Additionally, sample S1 was coated with citric acid (Co0.047Fe2.953O4@CA) and poly(acrylic acid) (Co0.047Fe2.953O4@PAA) to obtain stable colloids for further tests for magnetic hyperthermia applications in cancer therapy. Fits of the Box-Lucas equation provided SLP values of 21 W/g and 34 W/g for CA- and PAA-coated samples, respectively. On the other hand, X-ray photoelectron spectroscopy analysis points to the catalytically active centers Fe2+/Fe3+ and Co2+/Co3+ on the particle surface, suggesting possible applications of the samples as heterogeneous self-heating catalysts in advanced oxidation processes under an AC magnetic field.

Analytical model for static and cyclic creep behavior of pressure-sensitive adhesives

The increasing interest in adhesives, such as pressure-sensitive adhesives (PSAs), is often held back by uncertainties regarding their long-term behavior, which includes creep behavior. However, little information exists in the literature regarding creep behavior of PSAs. In this paper, a unified phenomenological creep model for PSAs is applied in SLJs for static and cyclic creep, seeking to develop a tool to predict creep behavior of PSAs. The model was validated by comparing the predicted creep curves with experimental data. It captured the three creep phases and predicted the creep curves for different stresses and temperatures, which is uncommon in literature.

Method Development for the Prediction of Melt Quality in the Extrusion Process.

Simulation models are used to design extruders in the polymer processing industry. This eliminates the need for prototypes and reduces development time for extruders and, in particular, extrusion screws. These programs simulate, among other process parameters, the temperature and pressure curves in the extruder. At present, it is not possible to predict the resulting melt quality from these results. This paper presents a simulation model for predicting the melt quality in the extrusion process. Previous work has shown correlations between material and thermal homogeneity and the screw performance index. As a result, the screw performance index can be used as a target value for the model to be developed. The results of the simulations were used as input variables, and with the help of artificial intelligence-more precisely, machine learning-a linear regression model was built. Finally, the correlation between the process parameters and the melt quality was determined, and the quality of the model was evaluated.