Inclination Research Articles

A Method for Studying the Size and Position of the Apical Bases of the Jaws Using Computed Tomography of the Jaws

The study of the apical bases has been relevant in orthodontics for many decades; its study was carried out both on jaw models and on lateral cephalograms. Dentistry today is impossible without three-dimensional studies, which allows you to study an object from any angle and visualize the smallest changes in the anatomical structures of the area under study. The use of cone beam computed tomography to study the apical bases of the jaws makes it possible to study the configuration, size, and position of both the bases themselves and the structures that form them. The parameters we proposed allow us to study the width, length and angle of inclination of the apical base on single CBCT sections. Clinical use of the proposed analysis will contribute to more complete and accurate orthodontic treatment planning.

Hydraulic Transport of Large Solid Particles in Inclined Pipes Under Pulsating Flow Conditions

Abstract The pressure loss due to the hydraulic transport of large solid particles should be predicted for the design of subsea mining systems. The mixture flow in a flexible jumper is expected to be unsteady during lifting operations in an actual mining system. The authors develop a one-dimensional mathematical model that predicts such pressure loss under pulsating mixture flows in a static inclined pipe assuming that the flow in the jumper is fully developed. An experiment is performed on the hydraulic transport of solid particles to obtain data for model validation. In this experiment, several kinds of solid particles are used: alumina beads, glass beads, and gravel. The experimental parameters are mixture velocity, solid concentration, pulsation period and amplitude of water velocity, and pipe inclination angle. The proposed model is validated through a comparison with experimental data. The validation confirms that the model is applicable for the prediction of the pressure loss in inclined pipes under pulsating flow conditions. Furthermore, we calculate the pressure loss due to the hydraulic transport of polymetallic sulfide ores using the proposed model. The calculation results show that the time-averaged pressure loss drastically varies with the pipe inclination angle, reaching its maximum value between the pipe inclination angles of 30 deg and 60 deg, at which the flow is inclined upward. The results also show that the amplitude of pressure loss pulsation differs little between pipe inclination angles and that the pulsation component of pressure loss should be considered in designing lifting systems.

Nonlinear interactions of an n-layer X-shape low-frequency vibration isolator equipped with a nonlinear vibration absorber at 1:1 internal resonance: analytical and numerical investigations

This work addresses, for the first time, the nonlinear dynamics of an n− layers bioinspired X− shape low-frequency vibration isolation system equipped with a nonlinear vibration absorber. The comprehensive mathematical model governing the two-degree-of-freedom system has been derived using Lagrangian mechanics. The method of averaging was applied to obtain an accurate analytical solution for the derived mathematical model. Utilizing the established analytical solution, the dynamical characteristics of the X− shape vibration isolator have been explored both as a single-degree-of-freedom system and after coupling with the proposed vibration absorber, as a two-degree-of-freedom system. The influence of different system parameters, including the number of structure layers, the initial inclination angle, the X− shape rod length, and the absorber stiffness and damping coefficients, on the vibration isolation performance has been investigated. The main findings indicate that while the single-degree-of-freedom X− shape low-frequency vibration isolator performs well in eliminating low-frequency vibration excitations, it exhibits strong vibration levels when the base excitation frequency exceeds the structure's natural frequency. Additionally, it was found that coupling a highly damped linear vibration absorber to the X− shape isolator not only eliminates the strong oscillations of the structure when subjected to high-frequency base excitations but also enhances the structure's low-frequency vibration isolation performance. Moreover, it was reported that integrating a nonlinear vibration absorber with either soft or hard spring characteristics instead of a linear one may degrade the vibration isolation performance of the structure rather than enhance it. Finally, numerical validation of all the analytical results was performed, which showed excellent correspondence with the analytical findings.

Investigation on mixed mode I/II crack propagation in nitrate ester plasticized polyether propellant: Experimental and numerical study

The fracture of solid propellant is predominantly attributed to the existence of mixed mode cracks, so it is essential to investigate the the fracture behavior of solid propellant with mixed mode I/II crack. This paper presents fracture characteristics of nitrate ester plasticized polyether (NEPE) propellant under different crack inclination angles (β = 30°–90°). Based on the combination of a drawing machine and a high-speed camera, the mechanical response, crack propagation velocity and crack-path morphology were investigated. The critical equivalent stress intensity factor Keqc was calculated to assess the fracture toughness of the NEPE propellant, and a potential simplified criterion related to the stress intensity factor was proposed. The experimental results demonstrated that the NEPE propellant with mixed mode I/II crack exhibited blunting fracture phenomena during crack propagation, resulting in fluctuating crack propagation velocity. As the crack inclination angle decreases, the fracture toughness of the NEPE propellant increases and then decreases, and the value of Keqc reaches its maximum at β = 45°. Furthermore, numerical studies based on bond-based peridynamic (BBPD) were performed by modeling the crack propagation process of the NEPE propellant, including the crack phase field diagram and the load–displacement curve of the NEPE propellant. The simulation results were then compared with the experiments.

Deformation and microstructure radial gradient evolution of AZ31 magnesium alloy bar during three-roll skew rolling

AZ31 magnesium alloy bar with radial gradient microstructure was prepared by three-roll skew rolling process (TRS), and achieving an excellent combination of ductility and strength. To elucidate the formation mechanism of this gradient microstructure, the deformation behavior during rolling was analyzed through experiments and simulations. The simulation results indicated that the metal flow of the bar in a spatial helical trajectory during rolling, with the trajectory inclination angle gradually decreasing from the center to the surface, promoting dynamic recrystallization in the surface and near-surface regions. The radial equivalent strain decreased from 1.5 at the surface to 0.01 at the center, and the shear strain decreased from 0.051 at the surface to 0.00012 at the center. Experimental results showed that the grain size of the bars decreased from 49.77 µm at the center to 19.72 µm at the surface, and the tensile twin volume fraction decreased from 34.1 % to 19.4 %. Dynamic recrystallization predominantly occurred in the outer ring region of the bars, while significant {10−12} tensile twin activation was observed in the central region, with twin-induced dynamic recrystallization observed at the twin boundaries. Mechanical property tests demonstrated that the gradient structure endowed the bars with a favorable combination of strength and elongation, with hardness significantly increasing from 50 HV at the center to 90 HV at the surface. This indicates that the three-roll skew rolling technology effectively promotes dynamic recrystallization at the surface, and the resulting gradient microstructure achieves an excellent combination of strength and plasticity in magnesium alloy bars.

花生清选筛台架的设计与试验

In order to address the high impurity and loss rates in the cleaning process of existing peanut combine harvesters, the design basis of the cleaning sieve was explored. Tests were conducted to determine the composition of the peanut picking fruit and the characteristics of the material suspension mixture. Additionally, the mechanical relationship between the fruit and miscellaneous mixtures and the cleaning sieve was investigated. The wind speed ranged from 8 m/s to 10 m/s, the vibration frequency ranged from 6 Hz to 8 Hz, and the inclination angle of the sieve ranged from 5° to 9°. The scavenger sieve platform was constructed and tested using Box-Behnken’s central combination test method. The optimal combination of fan wind speed (9 m/s), sieve surface inclination angle (8°), and sieve vibration frequency (7 Hz) resulted in a pod impurity rate of 1.16% and a loss rate of 1.4%. The device significantly reduces impurity content and loss rate during peanut harvesting. The study's results can serve as a reference for improving the design of the peanut combine harvester cleaning mechanism and optimizing operating parameters.

Timing and scintillation studies of PSR J1439−5501

Context. PSR J1439−5501 is a mildly recycled pulsar in a 2.12-day circular orbit around a heavy white dwarf. A white dwarf cooling model has estimated the companion mass to be between 1 and 1.3 M⊙ and the inclination angle to be greater than 55°. Such high mass and inclination are expected to induce a Shapiro delay, namely, a relativistic time delay in the signal propagation caused by the curved space-time induced by the companion. Until now, however, no Shapiro delay has been measured in this system. Aims. Our aim is to detect the Shapiro delay and, thus, to independently measure the mass and inclination of PSR J1439−5501 by using data from the Parkes and MeerKAT radio telescopes. Methods. The Shapiro delay parameters were measured through pulsar timing, which coherently accounts for every rotation of the pulsar. These measurements were then used to estimate the masses of the component stars and the inclination angle of the binary. A scintillation analysis was additionally performed by investigating the secondary spectra, which are the Fourier-transformed observed scintillation patterns. The obtained secondary spectral variations were analyzed in terms of the orbital motion and annual variation to estimate the ascending nodes, distance, and the location of the screen. Results. We obtained a highly significant measurement of the Shapiro delay, which allows estimates of the pulsar mass (1.57−0.26+0.30 M⊙), the white dwarf (WD) companion mass (1.27−0.12+0.13 M⊙), and inclination angle, (75(1)° or 105(1)°). These estimates assume that the companion mass cannot exceed the Chandrasekhar mass limit (1.48 M⊙), along with a lower limit of 1.17 M⊙ for NS masses. These results are consistent with previous studies, but the precision of the component masses has been improved significantly. The orbital and spin parameters and the large WD mass make this system very similar to that of PSR J2222−0137 and PSR J1528−3146, thereby suggesting a common evolutionary mechanism. The scintillation analysis suggests that the longitude of the ascending node is 16(7)° or −20(6)°, depending on the sense of the inclination angle. The screen distance is 260 ± 100 pc, potentially associated with the edge of the Local Bubble.

Thermo-fluid performance of axially perforated multiple rectangular flow deflector-type baffle plate in an tubular heat exchanger

The study investigated an unconventional heat exchanger design that utilizes swirling airflow to enhance heat transfer over heated tubes. This innovative system incorporates a perforated round baffle plate, accompanied by multiple rectangular air deflectors oriented in opposite directions at varying inclination angles. These deflectors are symmetrically arranged at different pitch ratios alongside consistently spaced tubes forming a circular configuration, all subject to a uniform heat flux. Enclosed within a circular duct with longitudinal airflow, the combined baffle plate and tube assembly bring forth efficient heat transfer. The air-side turbulence intensified by the deflectors induces a chaotic motion, contributing to enhanced surface heat transfer. Each baffle plate has twelve opposite-oriented deflectors, resulting in opposing swirl flows that further promote flow recirculation and augment surface heat transfer. The performance of this heat exchanger was evaluated by considering different pitch ratios and inclination angles across a Reynolds number range of 16000-30000. The findings demonstrate that the heat exchanger with rectangular flow deflectors on the baffle plate exhibits significant improvements in thermo-fluid performance. Notably, an average enhancement of 1.88 was observed at an inclination angle of 50 degrees and a pitch ratio of 1.2 when compared to an exchanger without baffle plates, emphasizing the considerable impact of these design aspects.

BPNN-based prediction for the shapes of a petal hole induced by hydrodynamic ram

The attitude angles of a projectile moving through a liquid are important factors that influence the dynamic failure of liquid-filled structures induced by hydrodynamic ram (HRAM). In this study, the effect of the attitude angles of a cylindrical projectile on the shapes of the petal hole in the rear plate of a kerosene-filled tank was investigated through ballistic impact experiments using three-dimensional digital image correlation, finite element simulations, and a back propagation neural network (BPNN). The inclination angle λ characterizing the shapes of the petal hole was related to the projection shapes of the projectile when impacting on the rear plate. The formation of petal-hole shapes was also accompanied by the formation of plastic hinge lines in the rear plate. Additionally, a method combining a BPNN and physical equations that accurately predict the drag coefficient and motion of a projectile moving through a liquid was proposed. A function describing the shapes of the petal hole was provided in the 2D space of the two initial attitude angles. The results provide offer insights into trajectory stability during liquid entry and aid in predicting the dynamic failure mode of a liquid-filled tank induced by HRAM.

Directional self-migration of droplets on an inclined surface driven by wettability gradient

In the current study, the anti-gravity directional self-migration of droplets on an inclined surface driven by wettability gradient (ω) was investigated using a front-tracking method. A unified mechanical model of droplet motion on an inclined wettability gradient wall was derived, considering the driving force generated by ω (Fd), gravity (G), and flow resistance (Ff). The model demonstrates that ω, G, and inclination angle (α) are key parameters affecting droplet motion. By varying ω, Bond number (Bo), and α, the droplet dynamic characteristics were analyzed, and a real-time Capillary number (Ca) was introduced to measure the droplet migration speed. The results indicate that a larger ω generates a greater Fd, leading to faster migration and more pronounced spreading. When the ratio of the channel width to the droplet diameter is 0.7, the droplet can cross three regions, obtaining double Fd, and Ca curve exhibits a bimodal structure. When the ratio of the channel width to the droplet diameter is 1.2, the droplet slides and spreads in the middle region without ω, resulting in a trimodal Ca curve. A larger Bo implies a stronger gravity effect, reducing the net driving force for upward migration and slowing the migration speed. At α=30° and ω=0.54, Bo reaches its critical value at 0.5, where G exceeds Fd, causing the droplet to slide downward along the wall. α affects droplet motion by controlling the gravitational component along the wall (Gx). A larger α results in a smaller net driving force for upward migration, reducing the migration speed.

Maximal transport of non-Newtonian fluid in an anisotropic rotating porous channel with an inclined magnetic field

This study explores the flow characteristics of a viscous, incompressible, conducting Jeffrey fluid in a rotating channel filled with anisotropic porous medium with an inclined magnetic field. The study has relevance to fluid motion in striated rock formations and seepage flow in rotating systems across insulation or geological layers. The channel's rotation axis and a principal axis of the permeability tensor are perpendicular to the walls. The flow is described by the Darcy–Brinkman model under no-slip boundary conditions, applicable in regenerative heat exchangers. Key parameters include the rotation rate and the lateral permeabilities. They have significant impacts on flow behavior. Fluid velocity consists of a primary component aligned with the pressure gradient and a secondary component influenced by the Coriolis force. The variation in lateral permeabilities affects the convexity of the velocity profile, while the magnetic field allows for control of both velocity and volumetric flow rates. The Jeffrey parameter and the inclination angle further enhance the flow behavior. This study provides comprehensive analysis through tables and figures for various values of the anisotropic Darcy number and the rotation parameter, detailing the model's physical properties. The effects of the product of skin friction and the Reynolds number are also discussed, with results aligning with the existing literature for limiting cases. These findings offer valuable insights into fluid behavior in complex environments where rotation, porous structures, and magnetic fields interact with implications for process optimization, resource recovery, and sustainable engineering practices.

Results in Engineering Experimental investigation of drag loss and plate separation behavior of wet clutches under external forces

Understanding the drag loss behavior of wet clutches is crucial for the development of low-loss clutch systems. For non-horizontal installation positions and non-stationary applications, external forces caused by the inclination or vehicle dynamics act on the plates. It has yet to be investigated how external forces influence the plate separation process and distribution and, subsequently, the drag loss behavior. Therefore, this study aimed to fundamentally investigate wet clutches' drag loss and plate separation behavior under the effect of external forces. The investigations were conducted in three steps. First, fundamental knowledge of the plate separation and drag loss behavior was gained. The effects of relevant design and operating parameters on the drag loss behavior were determined then. Separation springs were finally tested to avoid the influence of external forces. The drag loss and plate separation behavior were investigated on a drag torque test rig based on different clutch systems. The external forces were applied by inclining the test rig. The plate separation behavior was determined through image-based measurement of the plate movements. It was found that the plates separate under external forces and that the drag torque curve shows characteristics similar to wet clutches operated without external forces applied. The utilization of the set total clearance depends on the inclination angle. Hence, increasing the set total clearance does not generally imply lower drag losses, but increasing the inclination angle leads to higher drag losses. It was confirmed that the drag loss behavior is not influenced by external forces when using spacing elements. The findings of this study extend the existing body of literature and may support the development process of brake and clutch systems.

Numerical analysis of magnetohydrodynamic mixed convection and entropy generation in a curvelinear lid-driven cavity with carbon nanotubes and an adiabatic cylinder

Mixed convection convection is a vital subject and it is beneficial in many engineering applications. The current paper addresses this subject with a novel geometry and very vital variables including magnetohydrodynamic influences on the forced/free convection as well as the reproduction of irreversibilities in an enclosure filled with water/carbon nanotubes (CNT) and a nonadiabatic cylinder. The top wall is split from the middle and moves in different directions to drive the isotherms which are generated from the bottom wall and cold from the vertical surfaces. The numerical analysis was carried out using finite element method; the variables are Reynolds number (40–200), Richardson number (0.01–10), Hartmann number (0–62), inclined magnetohydrodynamic angle (0–60), volume concentration (0–0.08) while Prandtl number has kept constant at 6.2. The results show that the transformation of heat, as well as the fluid flow, are largely influenced by the change of variables, where increasing Reynolds number, Richardson number enhances heat and increases the flow circulation. Furthermore, heat transfer enhances by 57 % when increasing Ri from 0.1 to 10 at Re=41 and this enhancement increases to 62.5 % at Re = 200. Furthermore, increasing the concentration of the carbon nanotube can cause heat transfer but decrease the circulation of the fluid. In contrast, the transfer of heat as well as the flow streams are remarkably decreased with the increase of the Hartmann at zero inclination angle; however, the value of the Nusselt average increases with the increase of the inclination angle. Moreover, the value of Nusselt average decreses by 34.7 % when increasing Ha from 0 to 62 at Re = 200. Furthermore, the total entropy generation increases as Richardson number, Reynolds number, and volume concentration increase; in contrast, detraction with the rise of the MHD.

Computational fluid dynamics modeling of gas bubble separation efficiency in downhole separators and vertical / inclined annulus: An experimental validation and analysis

This study presents a comprehensive investigation into gas bubble separation efficiency in a vertical downhole separator using computational fluid dynamics (CFD) modeling, which is validated with experimental data. The research aims to provide detailed insights into the separation mechanisms and the factors affecting them, such as liquid velocity, gas bubble sizes, and positions. Using an Euler-Lagrange multiphase model, the behavior of individual gas bubbles within the liquid-gas mixture was simulated. The results demonstrate that separation efficiency decreases as the liquid flow rate increases. This reduction in efficiency occurs because the increased liquid flow rate drags more bubbles within the stream, making it harder for them to separate. The separation process is primarily driven by the buoyancy force acting on the bubbles and the velocity profile of the liquid flow. Smaller bubbles, which tend to be near the casing wall, separate more efficiently, while larger bubbles are predominantly located between the second and third quarters of the annulus space. The "quarters" refer to radial divisions from the casing wall to the tubing wall, with the first quarter closest to the casing wall and the fourth quarter closest to the tubing wall. The study introduces a nonlinear regression model based on the numerical results to predict liquid slug separation efficiency. This model, validated against experimental data, accurately predicts separation efficiency and offers a robust methodology for estimating the efficiency of gravity-driven gas-liquid separators. This methodology is crucial for refining separator design and improving the operational efficiency of downhole separation systems, which are vital for enhancing the performance of pumping systems in oil and gas wells. The contributions of this study include a deeper understanding of the downhole separation process, the development of a simplified model for assessing bubble separation efficiency, and the potential application of the proposed methodology to different gas-liquid separator designs and inclination angles, thereby informing the design and operation of downhole separation systems.

Numerical study on the polarity change process during internal wave shoaling

Polarity change is an important mechanism for internal waves shoaling. In this study, a numerical model for simulating the real-scale internal wave passing over slope-shelf topography is established based on the Fourier pseudo-spectral method and weakly nonlinear theory. By numerical simulation, the effects of shelf height, initial wave amplitude, and inclination angle on the waveform characteristics and energy properties of the internal wave during its shoaling are investigated. In the polarity change process, the initial internal wave converts into a depression wave and a generated elevation wave behind it. The distance between the peak of the elevation wave and the trough of the depression wave is a key feature to describe the polarity change. In terms of energy properties, the energy ratio of depression and generated elevation waves compared with the initial wave as well as their relative magnitude is mainly determined by the shelf height. In addition, the initial wave amplitude also affects the generation of the elevation wave and the attenuation of the depression wave to a certain extent. The increase in the inclination angle hinders the formation of the elevation wave but has little effect on the depression wave energy.

Non-simultaneous impact of droplet pairs on solid surfaces

This study delves into the dynamics of non-simultaneous droplet impacts on solid substrates, focusing on interactions between identical impacting droplets. Comparisons between non-simultaneous and simultaneous impacts are presented to understand the phenomena comprehensively. An in-house-built microcontroller-based droplet generator releases two equal-sized droplets on demand, allowing for simultaneous or non-simultaneous impacts. The interaction between impacting droplets generates an uprising sheet, whose characteristics vary with time lag between impacts, impact Weber number, and inter-droplet spacing. The evolution of central sheet characteristics, lamellae spreading dynamics, splashing mechanism, and secondary atomization is evaluated. Findings reveal that central sheet morphology varies with the time lag between impacts, transitioning from a two-dimensional (2D) “semilunar” sheet (vertical or inclined) with a linear base to a three-dimensional (3D) sheet with a curved base, increasing the probability of secondary atomization. The temporal evolution of the central sheet position, height, and inclination angle is governed by the momentum of spreading lamellae. A novel scaling law for maximum sheet extension and a theoretical expression for surface liquid spread are proposed, consistent with the measurements. The characteristics of secondary droplets generated during non-simultaneous impacts are similar to those from simultaneous impacts, with the size of the secondary droplets being one order of magnitude larger than those expected from isolated single-droplet impacts.

Nonoperative Management of Glenoid Baseplate Failure in Reverse Shoulder Arthroplasty

BackgroundGlenoid baseplate failure in reverse shoulder arthroplasty (RSA) remains a challenging problem. Nonoperative management may be an option in certain patients. The purpose of this study was to evaluate outcomes following nonoperative management of glenoid baseplate failure after RSA. MethodsUtilizing a single institution database, a retrospective review was performed to identify patients from 2010-2019 who sustained glenoid baseplate failures after RSA and were treated nonoperatively. Exclusion criteria included revision surgery and presence of active infection. Included patients had minimum 2 year clinical and radiographic follow-up. Chart review captured patient demographics, surgical indications and technique. Radiographs were reviewed to determine etiology of baseplate failure and other implant complications. Glenosphere inclination angle was measured on true AP radiographs immediately postoperatively and after baseplate failure. ResultsEighteen patients had glenoid baseplate failures treated nonoperatively during the study period. Five patients were deceased, leaving 13 patients who were available for clinical follow-up. Twelve (92%) patients were successfully contacted. Mean age was 77 years, BMI was 28, and 8/12 were female. Mean Charlson Comorbidity Index score was 4.1. Mean preoperative ASES score was 43.0 and VAS pain was 6.3. At mean 5.7-year follow-up, patients had an ASES score of 49.2, VAS pain of 4.3, SANE of 49% and 50% of patients were satisfied with their outcome. Preoperative and final follow-up ASES and VAS scores were similar. Average time from index surgery to baseplate failure was 19 months. Of the eighteen identified patients, 16 (89%) failures resulted in increased baseplate superior tilt (7 with concomitant broken baseplate screws). For these 16 patients, mean glenosphere inclination angle after failure (131°) was significantly greater than initial inclination angle (100°), p=0.03. The other 2 failures resulted in increased baseplate anteversion. 8/18 (44%) patients had bone grafting at the time of surgery. When comparing dissatisfied and satisfied patients, there were no specific patient characteristics or radiographic parameters that were associated with satisfaction. ConclusionNonoperative management of glenoid baseplate failure yields modest patient reported outcomes, with 50% patient satisfaction at mid-term follow-up. The mortality rate in this cohort of patients was almost 30%. Therefore, in select patients, nonoperative treatment of RSA baseplate failure may be a reasonable option.

Stability of a viscous liquid film flowing down an inclined plane with respect to three-dimensional disturbances

An analysis is presented for the stability of a viscous liquid film flowing down an inclined plane with respect to three-dimensional disturbances under the action of gravity and surface tension. Using momentum-integral method, the nonlinear free surface evolution equation is derived by introducing the self-similar semiparabolic velocity profiles along the flow (x- and y-axis) directions. A normal mode technique and the method of multiple scales are used to obtain the theoretical (linear and nonlinear stability) results of this flow problem, which conceive the physical parameters: Reynolds number Re, Weber number We, angle of inclination of the plane θ and the angle of propagation of the interfacial disturbances ϕ. The temporal growth rate ωi+ and second Landau constant J2, based on which various (explosive, supercritical, unconditional, subcritical) stability zones of this flow problem are categorized, contain the shape factors B and β owing to the non-zero steady basic flow along the y-axis direction. A novel result which emerges from the linear stability analysis is that for any given value of Re, We and θ, any stability that arises in two-dimensional disturbances (ϕ = 0) must also be present in three-dimensional disturbances. For ϕ = 0, there exists a second explosive unstable zone (instead of unconditional stable zone) after a certain value of Re (or θ) due to the involvement of B and β in the expression of J2. This explosive unstable zone vanishes after a certain value of ϕ depending upon the values of Re, We and θ, which confirms the stabilizing influence of ϕ on the thin film flow dynamics irrespective of the values of Re, We and θ.

Finite Element Analysis of Shear Performance for Reinforced Concrete T-Beams by Polymer Bars Strengthened with Carbon Fiber Using Embedded Through Section Technique

The purpose of this research presents the research results obtained from a numerical simulation using the ABAQUS/CAE version 2019 finite element software. This study tested the shear behavior of T-beams made of reinforced concrete (RC). The structure is reinforced with a carbon fiber reinforced polymer (CFRP) bar embedded through a section (ETS). The numerical validation approach implicated using numerical analysis on the experimental data collected from twelve reinforced concrete (RC) T-beams divide into two groups each group include reference beam, the field of numerical analysis was expanded to encompass the examination of many aspects, such as the impact of the diameter of CFRP bars. The main objective of this project is to create a computational model that accurately transcribes the complex nonlinear properties inherent in beams. This work conducts a comparative investigation of computational and experimental models, with a specific focus on their load-deflection features and cracking patterns. The study found that the average ratio of ultimate load to deflections in numerical model simulations for beams was 1.011, whereas in experimental testing it was 0.928. The research findings establish a clear correlation between the diameter of CFRP bars and the stiffness of a beam, assuming a constant angle of inclination and spacing.

Quantification of the hetero-contact formation process for a CuO/CeO2 hetero-aggregate model system prepared by double flame spray pyrolysis

In hetero-aggregates, different materials form sintered hetero-contacts, which lead to new material properties. In this study, the influence of process parameters on the formation of hetero-contacts in Double Flame Spray Pyrolysis (DFSP) was quantified. The mixing of jets was monitored by Particle Image Velocimetry (PIV) measurements as well as by thermocouples and compared to the single flame setting. Overlap of the jets was evaluated using tracers to visualize the mixing zone. Ten CuO/CeO2 model material samples were prepared with different flame inclination angles, nozzle distances and different particle volume fractions. Mixing on hetero-aggregate level was quantified using Convolutional Neural Network (CNN) evaluations of STEM images, Temperature-Programmed Reduction (TPR) and Differential Centrifugal Sedimentation (DCS) disk centrifugation to determine cluster sizes and hetero-coordination numbers as mixing quantifiers. Here, good correlations between the differently measured quantifiers were observed.