bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of Pressure Distribution in a Magnetorheological Squeeze Film Damper With Short Bearing Approximation Under Slip Conditions
Authors: Gómez Juan R. , Escandón Juan P. , Vargas René O. , Jimenez Edson M. 
Published: February 2024

Abstract
The present work analyzes the pressure distribution in a magnetorheological squeeze film damper which is used to attenuate mechanical vibrations in rotating systems. In this study, the mathematical model that describes the movement of the fluid is formed by the continuity equation, the momentum equation, the Bingham rheological model and the slip boundary conditions on the walls. Here, Reynolds equation is derived to determine the pressure distribution in the system, assuming a short bearing approximation. Additionally, this study assumes that the velocity of the fluid at the top wall corresponds to the angular velocity of the journal, and the height of the channel depends on the relationship between the bearing clearance and the eccentricity. In the results, velocity profiles and pressure distribution are presented as a function of the dimensionless parameters arising from the dimensionless mathematical model. These parameters are the viscosity ratio, the yield stress, the hydrodynamic slip and the channel height associated with the angular movement of the journal. Therefore, the theoretical results are intended as a contribution to the understanding of magnetorheological squeeze film dampers for applications in rotating systems such as turbines, pumps, aeronautical engines, gyroscopes, among others.
Dynamics of Two Parallel Inverted Flags in Axial Flow
Authors: Wang Shaoguang , Legrand Mathias , Païdoussis Michael P. 
Published: February 2024

Abstract
Two identical thin flexible plates, referred to as “inverted flags”, in a side-by-side arrangement are investigated theoretically. A linear model is developed to predict the onset of instability. This linear model elucidates the mechanism of instability and the sensitivity of the critical flow velocity to the gap between the two flags. The dynamics of a single flag has been studied massively, but the coupling of multiple flags is seldom reported. The Euler-Bernoulli beam theory and incompressible potential flow theory are adopted in the model. The Galerkin method and Fourier transform technique are used to solve flag displacements and fluid potentials, respectively. As the flow velocity is increased, the first mode becomes unstable via a pitchfork bifurcation. At higher flow velocities, higher modes lose stability via Hopf bifurcations. Out-of-phase and in-phase motions are predicted for the two flags. It is found that the critical velocity is independent of the flag gap-to-length ratio when it is approximately greater than 1. When the ratio is reduced, the critical velocity becomes smaller. When the ratio is extremely small, flutter occurs to the first mode before static divergence.
Temperature Field Around a Space Vehicle Descending in Mars Atmosphere
Authors: Rhisat Fahad Nizam , Molki Majid 
Published: February 2024

Abstract
Descending a space vehicle in Mars’s atmosphere is challenging. The main challenge is the unusual heating while the descending spacecraft moves at hypersonic speeds. This paper presents a computational model of a hypersonic flow around a spacecraft descending into Mars’s atmosphere. The work focuses on aerodynamic heating and the thermal field around the vehicle at hypersonic speeds. The mathematical model considers a three-dimensional, compressible hypersonic flow with bow shock waves. OpenFOAM, an open-source CFD code, solves the governing equations of mass, momentum, and energy using a finite-volume approach. The solver is a density-based, shock-capturing approach based on the central-upwind schemes of Kurganov and Tadmor. In this investigation, the turbulence model is Spalart-Allmaras. A clustered mesh resolves the super-fine boundary layer near the walls where large gradients dominate. This study focuses on the range of hypersonic Mach numbers from 5 to 27. A grid refinement study and comparison with the analytical solution verifies the solution approach and validates the results. This work aims to present the temperature field on and about the vehicle. The paper presents regions of subsonic and supersonic flows over the vehicle, surface temperature, and the contribution of aerodynamic heating.
Novel Lockable Passive Joints for Joint Locking-Based Reconfigurable Mechanisms
Authors: Rosyid Abdur , El-Khasawneh Bashar 
Published: February 2024

Abstract
This paper presents a novel design of lockable passive prismatic, revolute, universal, and spherical joints that can be used in a joint locking-based reconfigurable mechanism. The proposed lockable joints offer several advantages, including 1) modularity, 2) small locking force/torque, 3) low-power active trigger, 4) no-slip, and 5) simplicity. All the lockable passive joints proposed in this work provide locking at one or multiple discrete positions, considering that it is the requirement. The modular design, in particular, provides a cost-effective solution for the manufacturing and maintenance of the joints. Designed to have one or more discrete locking positions, the proposed lockable joints have a self-aligning capability that increases the reliability of the locking action. The locking action can be triggered by a low-cost, low-power, short-stroke binary piston such as a solenoid. While the trigger only requires small power, the locking action provides strong locking provided by mechanical locking.
Asymmetrical Auxetic Structures for Impact Force Mitigation
Authors: Yang Chulho , Lee Dongchan , Worwag Ben 
Published: February 2024

Abstract
This research is aimed at proposing an enhanced re-entrant hexagonal structure and examining its auxetic behavior in compressive or tensile load conditions. Auxetic materials, also known as materials with negative Poisson’s ratio (NPR), have been designed and fabricated for diverse applications that utilized normal materials which follow Hooke’s law but still show the NPR properties. One of the major applications is body protection pads that are comfortable to wear and effective in protecting body parts by reducing impact force and preventing injuries in high-risk individuals such as elderly people, industry workers, law enforcement and military personnel, and sports players. Another application is soft robotics for which the auxetic structures are used as sensors and actuators while protecting the wearer in the event of falling or collision. It is important to develop a new garment that best combines each individual’s requirements for wearing comfort, ease of fitting, ensured protection, and cost-effectiveness. The garment would be made from multilayer materials and adaptive structures to achieve unique multifunctional properties such as high hardness, impact toughness, adjustable stiffness, lightweight, and excellent shock absorption.
This paper reports an integrated theoretical, computational (finite element analysis, FEA), and experimental investigation conducted for newly designed asymmetrical auxetic structures that exhibit the NPR effect and good impact force absorption or diversion capability. When an impact force is applied to a protective pad, especially right at the most vulnerable location of possible injury, absorption, and diversion of the impact force are the critical factor for the protection of the human body. For use in soft robotics, different patterns of deformations are also desirable for different motions of body parts and joints. Asymmetry along a longitudinal axis and lateral axis and also repetitive patterns in different directions were studied. Various combinations of auxetic cell patterns were modeled and investigated. 3D CAD models of auxetic structures were developed and their structural characteristics were evaluated through static analyses of FEA models. Through FEA, force and stress distribution on the bottom of the auxetic pads were examined while impact forces were applied on the top surface. The 3D-printed prototypes were then tested, and the results were compared with the computational prediction. Different profiles of stress and force distribution were observed for different patterns. The mitigation of impact forces was also observed. The simulation and test results showed that the asymmetrical auxetic material has high NPR and can be effective for absorbing or diverting impact forces.
Microgrid Partitioning: an Impact Assessment of Integrating a Photovoltaic System With Electrical Energy Storage Devices
Authors: Baniatta Ban , Azzam Ahmad , Abdelsalam Emad , Nawafah Hamza , Kafiah Feras , Qandil Hassan 
Published: February 2024

Abstract
This work assesses the impact of integrating a photovoltaic (PV) system with electrical energy storage devices at a business park in Jordan. The electrical grid of the business park was partitioned as a microgrid from the main national electrical grid. DigSILENT software was used to model the single-line diagram of the microgrid. A total of 0.5 MW PV system and a 0.5 MW Li-ion storage system were assessed in this study. Voltage loadings and frequency were among the measured simulation parameters to evaluate the impact of the integration on the distribution level. The results showed that the harmonic distortion did not exceed the 3% limit set by the IEEE standard for systems under 69 kV. The results also showed that the load flow analysis for the voltage profile was stable and was within the allowed limit of 0.95–1.05 p.u. Furthermore, the integration has resulted in a reduction of up to 1,247 Metric Tons of equivalent CO2 emissions annually.
Energy Harvesting by Vortex-Induced Vibrations of Structures With Different Cross-Sections
Authors: Ali Ussama , Islam Md. , Janajreh Isam 
Published: February 2024

Abstract
The shape of the structure plays a crucial role in determining its vibration characteristics, such as the amplitude and frequency of vibration. The purpose of this investigation is to explore how the flow-induced vibration behavior and energy harvesting potential are impacted by the cross-sectional shape of a structure. In this work, the cross-sectional shapes of the bluff body considered are circular, square, diamond, and triangle. The reduced velocity (Ur) is varied in the range of 2–12. The mass ratio is taken as 1.7, and the damping ratio as 0.016. The hydraulic diameter for all the shapes is kept constant, and the Reynolds number based on the hydraulic diameter is varied in the range of 1.7 × 104 to 10.3 × 104 to mimic the flow velocity of the water current in the ocean (0.19–1.14 m/s). In this work, water is considered as the flowing fluid, which is supposed to be incompressible and viscous. The flow dynamics of the fluid over a bluff body are described using the unsteady Reynolds Averaged Navier-Stokes equations, and the turbulence is modeled through the SST k-ω turbulence model. Based on the findings, it can be concluded that the shape of the bluff body has a significant impact on both the vibration characteristics, the output power, and the efficiency of energy harvesting. The analysis suggests that circular shapes are ideal for energy harvesting from flow-induced vibrations at low Ur, while diamond shapes are most suitable at high Ur. In this study, the maximum output power of 1.57 W was obtained with a diamond-shaped structure at Ur = 10. Whereas the maximum efficiency of 9.01% was obtained through the circular structure at Ur = 4.
Experimental Study of Monovalent Salt and Hydrochloric Acid Solution Effects on the Stability of Blank Oil-Water Dispersion in Batch Separators
Authors: Alanazi Khalid , Mohan R. , Kolla S. S. , Shoham O. 
Published: February 2024

Abstract
The effect of aqueous phase salinity and acidity on the stability of oil-water dispersion is poorly understood. This is because most research works use complex solutions of mixed monovalent and divalent salts to replicate the composition of brine solution in the aqueous phase of crude oil emulsion. Hence, the relevance of each form of ionic solution cannot be determined without isolating and analyzing a laboratory-created oil-water dispersion. Toward this objective, this study aims to investigate the impact of monovalent salt solution and acidic water on the stability of blank (emulsifier-free) oil-in-water (O/W) and water-in-oil (W/O) emulsion. Fluids were mixed at a constant stirrer speed (2,500 rpm) and time (5 minutes) for each investigated emulsion. Mineral oil (EXXSOL™ D110) and distilled water with density and viscosity ratios of 0.805 and 0.330, respectively, were chosen as the pure fluids. Sodium chloride (NaCl) was used to vary the concentration of monovalent salt (from 1 to 60 g/L) in the aqueous phase, whereas a 1.0 M hydrochloric acid solution was used to alter the acidity (pH = 4.80 to 1.88) of distilled water. Experiments ranging from less than a minute to several hours were conducted using four water cuts (WC = 25%, 50%, 75%, and 90%). The brine and acidic water phase had shown large impacts on the stability of O/W (90% and 75% WC) emulsions but had minor effects on W/O (25% and 50% WC) emulsions.
Experimental Investigation, Characterization, and Microstructural Enhancement of Laser Cladded Al-Si-Sn-Cu/Ti-6Al-4V Composite Coatings
Authors: Fatoba Olawale Samuel , Jen Tien-Chien 
Published: February 2024

Abstract
The manufacturing sector has not yet experienced a significant additive manufacturing (AM) effect. This is because there are a number of technical obstacles to be surmounted, such as a lack of process comprehension and in-situ process monitoring and quality control, particularly in metal AM systems. These factors can have a significant impact on the microstructure and the functionality of the manufactured coatings. AM processing parameters can be challenging to fine-tune. The process parameters can cause part deformation and microcracks, residual stresses that develop in the parts/coatings being made severely restrict their actual use. The study focuses on improving the mechanical and hardness properties of the titanium alloy (base metal) using quaternary (Al-Si-Sn-Cu) reinforcement coatings and direct laser metal deposition (DLMD) technique. The experimental work was carried out in South Africa at the National Laser Center (Pretoria) using a 3000 W Ytterbium Laser System (YLS). Multiple tracks were used, each measuring 65 mm in length, with a 2 mm spot diameter. For the purpose of characterizing the materials, standard method was used. The process factors were optimized using a L9 orthogonal design of experiment. Process variables included varying laser power, powder feed rate, and scan speed. According to the findings, the formation of titanium-aluminum (Ti3Al) led to a rise in copper weight percentage, which improved tensile strength, yield strength, and hardness properties. Additionally, copper atomic mobility during solidification led to the formation of the beta-titanium phase. The polished grains were created by adding layers, which resulted in the formation of the thin columnar and elongated grains. Increased scanning speed led to finer grains being created in the microstructure due to a faster cooling rate.
A Numerical and Experimental Investigation About Tensile Fracture in Epoxy Composite Grout Under Thermo-Mechanical Load
Authors: Waseetuddin Nahri S. , Abubakar Abba A. 
Published: February 2024

Abstract
Grouts are designed to provide high load-bearing capability and chemical/material compatibility in building structures’ crevices, cracks, and gaps. Much research has recently been conducted concerning replacing conventional cementitious grout with polymer-based materials. The present study investigates the fracture behavior of epoxy composite grout under flexural loads and different temperatures. The flexural fracture will be the primary fracture mechanism considered in this study. The XFEM, combined with experimentation, will be used to study the influence of thermo-mechanical flexural load on the fracture behavior of epoxy grout. The XFEM method simulates deformation, stresses, strains, and cracking behavior without needing re-meshing and any equation inputs. The numerical simulation is carried out for the epoxy and the cementitious samples at 25°C and 65°C. Experiments are performed for the benchmark flexural problem, and its results are further validated by comparing them with the XFEM simulation. The flexural strength of epoxy grout is much higher than that of the cementitious one at 25°C. Significant micro-cracking in cementitious grouts is observed, further decreasing its capacity to withstand high loads. The strength of the epoxy grout decreases with increasing temperature. The presence of voids increases with temperature, weakening the epoxy material structure under high temperatures. Selecting a more compatible filler material type, shape, and size can enhance the fracture toughness of epoxy composite grout.
Computational Modeling of Extreme Particles Deformation and Grain Refinement During Cold Spray Deposition
Authors: Abubakar Abba A. , Al-Athel Khaled S. , Akhtar Syed S. 
Published: February 2024

Abstract
When deposition parameters are carefully set, cold spraying can successfully deposit composite coatings with customized characteristics. To avoid conducting repeated experimental trials, numerical simulations are critically needed to optimize the cold spray deposition parameters. During cold spraying of the composite layer, extreme particle deformation and temperature rise occur due to the complex interactions among dissimilar particles; hence, the coating layer properties vary across the thickness. In the cold spray literature, particle grain refinement is not considered in numerical simulation studies. The present study uses a physics-based hybrid computational technique to simulate multi-material particle deformation during the cold spray deposition of Ni-Al2O3 coating utilized for wear applications. The hybrid approach effectively combines point cloud and finite element models to simulate particle deformation and interactions during the cold spray process. An attempt to predict the grain refinement due to extreme deformation and dynamic recrystallization of deformed particles is made for the first time using the phase field method (PFM). The strain field and temperature distribution are used to predict the grain size evolution in the deformed particles. The numerical simulation results are validated by comparing them with those of experiments. The results show that the softer Ni (matrix) particles undergo higher deformation, and their deformation pattern is strongly affected by the presence of neighboring Al2O3 particles. Due to higher plastic strain and strain rate, the particle’s deformation affects the grain size evolution, mainly in the Ni matrix material. The extremely deformed regions, such as Ni particle interfaces and edges, demonstrate the possibility for grain refinement according to simulation data on strain rate, temperature, and deformation among dissimilar particles. The current study aims to establish a reliable numerical methodology for the optimization and prediction of properties of composite made from cold spraying.
Atmospheric Water Capture Potential in Arid Countries: An Experimental Investigation
Authors: Rashad Muhammad I. , Mourad Nada , Mubarak Abdallah , Faiad Hend A. , Ahmed Shehab , Farahat Mohamed A. 
Published: February 2024

Abstract
The decline in freshwater supply is a multifaceted global problem that affects both developing and developed countries. In the MENA region, groundwater reserves are overexploited, leading to a heavy reliance on desalination as a main source of drinkable water. However, desalination requires high capital investment and adequate infrastructure. Lack of proper infrastructure further delays implementation of large-scale desalination plants, posing threats to economic growth, social development, and public health, particularly in developing countries. One potential solution in regions with high humidity and temperatures is atmospheric water generation (AWG), which can be used in addition to conventional desalination methods. This could be a promising solution for poor countries with limited infrastructure facing water scarcity challenges. In this study, an experimental setup utilizing a conventional vapor compression cycle (VCC) is designed, built, and tested to produce drinkable water by removing and collecting moisture from humid air. The setup includes an Aluminum-Copper finned tube condenser and a coil-shaped Copper evaporator placed perpendicular to the airflow direction in a horizontal configuration. A controlled fan is used to drive the airflow throughout the system, with the dehumidified cold air from the evaporator directly cooling the condenser for improved energy recovery. The dew point temperature (DPT), relative humidity (RH), and ambient temperature were monitored during experiments. Results show that this system yields an average of 33 litres/m2 per day where the DPT &gt; 12°C and RH &gt; 55%.
A Novel Device for the Standardized Intraoperative Preparation of Non-Valved Glaucoma Tube Shunts
Authors: Alzoubi Faleh , Laird Jack , Mallory Caleb , Stewart Mallory , Zachariah Natalie , Eichaker Lauren , Evans Joshua 
Published: February 2024

Abstract
Glaucoma refers to a category of eye conditions that involve damage to the optic nerve and is characterized by high intraocular pressure (IOP). This optic nerve damage causes pain and discomfort; in chronic cases, it can lead to long term vision loss and sometimes blindness. After failure of preliminary treatment such as drops and medication, late-stage glaucoma patients often undergo surgical intervention in which a drainage shunt is implanted to lower IOP. The shunt tube implantation surgery remains variable in both procedures and outcomes as there does not exist a one-size-fits-all-method or tool for implant and procedure customization.
There is currently a lack of predictability of outflow characteristics of tube shunt fenestrations due to the lack of a method to standardize the creation of fenestrations, leaving the number and size of fenestrations up to the surgeon. Additionally, the ligation of the base of the tube can be difficult and time consuming, which can lengthen surgical time.
Towards improving non-valved tube shunt procedures, this study describes a novel device to standardize the creation of fenestrations in tube shunts at the bedside. The device will standardize the size and placement of the fenestrations by acting as a guide to place a blade or needle. In this way the guide will allow for predetermined fenestrations to be placed at standard depths. Additionally, a preliminary mathematical model has been created to predict outflow characteristics of the novel device as a function of fenestration number. Validated mathematical models hold clinical value in predicting outflow characteristics and tailoring patient care.