bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comprehensive Thermodynamics Investigation of a Solar-Powered Hydrogen Production Plant
Authors: Alsaleem Sulaiman M. 
Published: September 2024

Abstract
Green hydrogen production utilizing a solar-powered proton exchange membrane (PEM) electrolyzer is a promising technology for generating clean energy and reducing greenhouse gas emissions. This work presents a comprehensive thermodynamics study to investigate producing hydrogen gas through PEM electrolysers driven by solar-powered Rankine cycles. Parabolic trough solar collectors supply thermal energy to a single-stage Rankine cycle (SRC) and a binary steam-organic Rankine cycle (SRC-ORC) using different refrigerants to generate electricity that powers the electrolysers. First and second law analysis on solar collectors, power cycles, and PEM electrolysers are presented. Over the solar irradiation range (Gb = 600–1000 W/m2), results show that (SRC-ORC) configuration produced the highest hydrogen rate when using the R134a and R744 as working refrigerants in the ORC. Moreover, at a Gb = 800 W/m2, the model shows that (SRC-ORC) yields higher energetic and exergetic efficiencies compared to the corresponding (SRC) by about 12% and 14%, respectively. The analytical model reveals that more than half of the exergy input to the system was destroyed in the electrolysers followed by solar collectors and then power cycles. This highlights the necessity to optimize the design of PEM electrolysers to enhance the hydrogen production rate.
Two-Degrees of Freedom Flow-Induced Vibrations and Heat Transfer of Twin Cylinders in Tandem and Staggered Arrangements
Authors: Ali Ussama , Islam Md. , Janajreh Isam 
Published: September 2024

Abstract
The emergence of flow-induced vibrations (FIV) is critical in industrial systems like heat exchanger tubes and marine risers, posing challenges in modern shell-and-tube heat exchanger design due to tube failures from fatigue damage. This work explores the impact of cylinder configurations on flow-induced oscillations and heat transfer in laminar regime at a Reynolds number of 100. Both cylinders were allowed to oscillate in two-degrees of freedom, experiencing motion both along the flow direction (streamwise) and transverse to it. The configuration of the two identical circular cylinders varied from tandem alignment (α = 0°) to staggered (α = 30° and 60°). The spacing between the two cylinders remained at 6D, with D representing the cylinder’s diameter. The cylinders were heated at a constant temperature to observe the heat transfer characteristics influenced by the two-dimensional FIV. To investigate the FIV, the reduced velocity (Ur) was systematically adjusted within the range of 2 to 12. The findings revealed the responsiveness of the cylinders to variations in reduced velocity and cylinder configurations, particularly with regard to vibrations and heat transfer. The tandem alignment resulted in most pronounced vibrational responses in both cylinders. Both cylinders exhibited lock-in behavior within the range of Ur = 6 to 8, with significant transverse vibration amplitudes. Downstream cylinder (DC) experienced the widest span of lock-in in the tandem configuration. Streamwise vibrations were insignificant when compared to their transverse counterparts. Different vorticity patterns emerged in the wake of the cylinders, due to the different configurations. The staggered setup with α = 60° lead to a substantial 75% reduction in transverse vibrations and a 9% elevation in the Nusselt number for DC compared to the tandem configuration.
Flow and Heat Transfer Characteristics in Arrays of Stationary and Elastically Supported Cylinders
Authors: Kumar Sanjeev , Islam Md. , Fatt Yap Yit , Janajreh Isam 
Published: September 2024

Abstract
This study investigates FIV and heat transfer in arrays of stationary and elastically supported cylinders by considering nine heated circular cylinders with inline arrangements. A 2-D numerical simulations considering low Reynolds number and forced convection heat transfer are carried out using ANSYS Fluent loaded with user-defined function (UDF). User-defined function (UDF) governs cylinders’ displacements in y-directions for elastically supported cylinders. Several parameters are considered, including a reduced velocity range of 2–12, a fixed centre-to-centre distance between cylinders of 3D in both direction i.e. transverse and streamwise, a Reynolds number of 100, a Prandtl number of 0.7, and a constant mass ratio of 2. The heat transfer performance is investigated in elastically supported cylinders and then results are compared with arrays of stationary cylinders to understand the significance of FIV. The results of this study indicate that the flow pattern for arrays of elastically supported cylinders depends on the reduced velocity, and it is different from that of arrays of stationary cylinders. At lower reduced velocities, it follows the almost same flow pattern as stationary cylinders. Additionally, it is observed that FIV in elastically supported cylinders shows a significant improvement in the average Nusselt number up to 39% for arrays of elastically supported cylinders when compared with arrays of stationary cylinders.
A Convolution Neural Network Design for Combined Image and Sensor Data Analysis to Determine Droplet Vaporization Regime and Heat Transfer Performance
Authors: Tchouteng Njike Ursan , Silva Anisa , Carey Van P. 
Published: September 2024

Abstract
Combining high-speed video cameras and optimal measurement techniques with digital sensors controlled by a data acquisition system can yield a combination of experimental tools to explore boiling process thermophysics and heat transfer mechanisms. Imaging can provide qualitative and quantitative information that complements data provided by temperature, pressure, and more sensors. This paper summarizes the results of an exploration of machine learning strategies to optimally combine and analyze boiling process images and digital sensor information from experiments. We specifically sought a convolution neural network to analyze the vaporization of deposited water droplets on superheated surfaces that may have varying degrees of nucleate boiling effects. Through experimentation, we found that a hybrid parallel-series convolution/neuron neural network design worked very effectively. The network could extract the regime of droplet vaporization (conduction driven only, conduction plus nucleate boiling, or explosive boiling), the liquid morphology, and could predict the vaporization regime, the wall superheat, and mean heat transfer rate as a function of image input and operating system parameters. Using data collected from the droplet deposition experiment, this network design has been trained to predict the mean heat transfer rate with a root mean square percent error (RMSPE) of only 3.3% and 7.2% on a training and testing dataset respectively. The hybrid network developed in this research appears to be a promising strategy for analyzing experimental data for physical systems that are best investigated experimentally with a combined use of imaging and digital sensor instrumentation.
Prediction of Airflow and Temperature Distribution in Data Centers With Focus on Containments
Authors: Karki Kailash , Radmehr Amir , Patankar Suhas 
Published: September 2024

Abstract
This study uses CFD modeling to predict the behavior of containments in data centers under various operational and design conditions. The focus is placed on cold-aisle containments, but the discussion and results are equally applicable to hot-aisle containments. The parameters considered are the flow rate of cooling air entering the aisle in relation to the airflow demand of the racks, leakage areas on the containment walls and racks, and airflow characteristics of the servers. Results are presented for both steady-state and transient scenarios.
Enhanced Heat Transfer Through Additively Manufactured Architectured Lattice Frame Materials in SS316L and Ti-6Al-4V
Authors: Aider Youssef , Kaur Inderjot , Mujahid Shiraz , Paudel YubRaj , Rhee Hongjoo , Singh Prashant 
Published: September 2024

Abstract
High porosity metal foams have been proven to yield high rates of heat dissipation. However, metal foams are available in limited configurations in terms of pore density and porosity as well as in limited materials, such as aluminum, copper etc. For the design and development of next generation high temperature heat exchangers, a significant increase in the heat transfer performance is required at a reasonable increase in pumping power, while at the same time, the materials should withstand the high temperatures as well as the mechanical loads. To this end, novel architectured materials with superior thermal performance as well as load bearing capabilities are designed and developed, with the support of state-of-the-art metal additive manufacturing. Three different unit cell topologies, viz. Tetrakaidecahedron (TKD), Rhombic-Dodecahedron (DDC) and Octet, are additively manufactured for porosities ranging between 0.7 and 0.9, in two materials Stainless Steel 316L and Ti-6Al-4V. Experiments have been conducted to determine the effective thermal conductivity and the convective heat transfer coefficient for the above samples with air as working fluid. The convective heat transfer experiments were carried out for air flow velocities ranging from 1–7 m/s through lattice frame samples which were one unit cell thick. The single unit cell configuration was designed to fully leverage the conjugate heat transfer capabilities where the struts are directly attached to the wall subjected to heat load. In general, the heat transfer for the lowest porosity samples of each topology was higher compared to the two higher porosity samples. The same is true for the pressure drop. For the highest porosity (0.9) samples, Octet performed marginally better than the TKD and DDC configurations for SS316L materials, while for the Ti-6Al-4V, the performance of the three unit cells were nearly similar for the 0.9 porosity. SS316L test articles exhibited higher convective heat transfer compared to the Ti-6Al-4V samples.
Flow Boiling Heat Transfer Characteristics of R32 Outside Three-Dimensional Enhanced Tubes
Authors: Zhang Chenglin , Li Wei , Wang Xu , Kukulka David John , Ma Keshuai , Sherif S. A. , Wang Zepeng 
Published: September 2024

Abstract
Flow boiling heat transfer characteristics of R32 on the outside surface of three-D enhanced copper tubes have been experimentally investigated. One enhanced tube has been studied along with a smooth tube (ST tube) of the same diameter for comparison purposes. The enhanced tube has diamond stripes and a spherical shape (referred to here as the LEHT tube). Experimental conditions included saturation temperatures of 279, 283, and 288K; average vapor qualities ranging from 0.2 to 0.8; and mass fluxes ranging from 70 to 230 kg/(m2s). Both the heat transfer coefficient and frictional pressure drop in the LEHT tube increased with an increase in the mass flux. For the smooth tube, the effect of the average vapor quality on the heat transfer coefficient was found to be less significant compared to that of the LEHT tube. The heat transfer coefficient of the LEHT tube was also found to first increase and then decrease as the vapor quality increased. Finally, the frictional pressure drop in both tubes has been found to be inversely proportional to the saturation temperature, with the saturation temperature having little impact on the heat transfer coefficient.
A High-Power Volumetric Two-Photon Polymerization/Lithography Scheme Without Using Beam Splitters
Authors: Jakkinapalli Aravind , Wen Sy-Bor 
Published: September 2024

Abstract
A phase-controlled spatial light modulator to split one laser pulse into tens of thousands of mini rays, each propagating into a designed direction to form a 3D point cloud, has been proposed and demonstrated recently. The original experimental design needs a beamsplitter to couple the femtosecond laser light to the phase-controlled spatial light modulator. Thus, only one-fourth of the incoming laser light is used in the volumetric lithography after two reflections with the beamsplitter. This study proposes a tilted coupling scheme between the femtosecond laser and the phase-controlled spatial light modulator. Because no beamsplitters are required in the new scheme, the useful laser energy is four times higher than the original scheme, and the required exposure time to cross-link polymer through two-photon absorption is sixteen times shorter.
A new mathematical model has also been developed to generate the phase diagram on the phase-controlled spatial light modulator to diffract light into the required directions to form voxels in the designed 3D point clouds. The new mathematical model considers the tilted incoming laser light and the required adjustment to ensure mini rays arrive at the voxel locations simultaneously to trigger two-photon absorption. The resulting phase diagram for projecting vertical lines, tilted lines, and micro pyramids with the new mathematical model for the tilt coupling scheme is presented. The resulting lithography results and the possible future improvements considering the diffraction of mini rays are also discussed.
Exploring the Energy and Exergy Performance of an Integrated Heat Recovery System in Aluminum Smelters Using a Parallel Two-Stage Organic Rankine Cycle
Authors: Abdelsamie Mostafa M. , Ali Mohamed Ibrahim 
Published: September 2024

Abstract
The primary aluminum industry stands out as one of the most energy-consuming and occasionally inefficient sectors, with approximately 50% of energy lost as waste heat. The challenge lies in the multitude of heat sources in aluminum smelters, each varying in quantity and temperature levels. Addressing this, the study employs the Parallel Two-stage Organic Rankine Cycle (PTORC) to integrate wasted heat from cathode sidewalls and exhaust gases into a unified recovery system. Based on a series of simulations, the current analysis delves into the impact of primary and secondary evaporation temperatures, as well as the number of integrated aluminum pots, on the energy and exergy performance of PTORC. Under specific design conditions, the results reveal that optimizing the system occurs when the primary evaporation temperature decreases and the secondary evaporation temperature increases. This leads to a substantial enhancement in both output power and thermal efficiency, accompanied by a reduction in exergetic destruction. At a primary evaporation temperature of 111.5°C and a secondary evaporation temperature of 78.5°C, the net output power reaches an optimal value of 3,840 kW. However, despite the increase in generated power, the exergy destruction of the recovery system experiences a notable rise with the number of integrated cells.
Navigating Virtual Collisions: Insights Into Perception–Action Differences in Children and Young Adults Using a Head-On Avoidance Task
Authors: Hammill Megan , Rapos Victoria , Cinelli Michael 
Published: September 2024

Children tend to make more last-minute locomotor adjustments than adults when avoiding stationary obstacles. The purpose of this study was to compare avoidance behaviors of middle-aged children (10–12 years old) with young adults during a head-on collision course with an approaching virtual pedestrian. Participants were immersed in a virtual environment and completed a perceptual decision-making task in which they had to respond to the future direction of an approaching virtual pedestrian once they disappeared. Following the perceptual task, participants walked along an 8-m pathway toward a goal, while avoiding a collision with a virtual pedestrian who approached along the midline than veered toward the left, right, or continued walking straight. Results revealed that children were able to correctly predict the future directions of the virtual pedestrian similar to adults, albeit at a slower response time (0.55 s vs. 0.33 s). During the action task, children initiated a deviation in their travel path later (i.e., closer to the virtual pedestrian) compared to adults (1.65 s vs. 1.52 s). Children were also more variable in their onset of deviation and time-to-contact. Although children appear to have developed adult-like perceptual abilities and can avoid an approaching virtual pedestrian, children employ riskier avoidance strategies and are highly variable, suggesting middle-aged children are still fine-tuning their perception-action system.
Ultraslow cooling of an ultrahot orogen
Authors: Clark Chris , Brown Michael , Knight Ben , Johnson Tim E. , Mitchell Ruairidh J. , Gupta Saibal 
Published: September 2024

Abstract
To constrain the rate of cooling of lower-crustal rocks from an ultrahot orogen, we determined both the age and equilibration temperature of metamorphic zircon from six widely spaced samples of metasedimentary garnet–sillimanite gneiss from the Eastern Ghats Province in eastern India. For the combined data set of metamorphic zircon, concordant dates decrease continuously within 2σ uncertainty from around 950 Ma to 800 Ma, consistent with ∼150 m.y. of zircon crystallization. Ti-in-zircon temperatures for each dated spot during this period decrease with age, corresponding to linear cooling rates ranging from 0.26 to 0.90 °C/m.y. We propose that retention of heat-producing elements in the lower crust of the Eastern Ghats Province and a low net erosion rate were responsible for ∼150 m.y. of ultraslow cooling.
Molecular Dynamics Calculation of Interfacial Tension in a Two-Phase Liquid Hydrocarbon–Water–Surfactant System: From Rarefied to Superdense Surfactant Monolayer
Authors: Vanin A. A. , Volkov N. A. , Brodskaya E. N. , Shchekin A. K. , Turnaeva E. A. , Polovinkin M. S. , Eroshkin Yu. A. 
Published: September 2024

Abstract
A method is proposed for calculating low interfacial tension (IFT) based on molecular dynamics simulation of systems with superdense packing of surfactant molecules at the water–liquid hydrocarbon interface. The interfacial tension was calculated by the molecular dynamics method using the all-atom and coarse-grained models in water–alkane (decane, dodecane) two-phase systems in the presence of various individual surfactants. The following ionic and nonionic surfactants were considered: sodium dodecyl sulfate (SDS), cetyltrimethylammonium chloride (CTAC), sodium dodecylbenzenesulfonate (SDBS), sodium decet-6 sulfate C10E6SO4Na, hexaethylene glycol monodecyl ether (C10E6), triethylene glycol monononadecyl ether (C19E3), and octapropoxypentaethylene glycol monododecyl ether (C12P8E5). It was shown that the interfacial tension decreases to zero when surfactant adsorption increases to the limiting values.
Validation of a machine learning algorithm for identifying infants at risk of hypoxic ischaemic encephalopathy in a large unseen data set
Authors: Murray Anne L , O’Boyle Daragh S , Walsh Brian H , Murray Deirdre M 
Published: September 2024

ObjectiveTo validate a hypoxic ischaemic encephalopathy (HIE) prediction algorithm to identify infants at risk of HIE immediately after birth using readily available clinical data.DesignSecondary review of electronic health record data of term deliveries from January 2017 to December 2021.SettingA tertiary maternity hospital.PatientsInfants >36 weeks’ gestation with the following clinical variables available: Apgar Score at 1 min and 5 min, postnatal pH, base deficit, and lactate values taken within 1 hour of birthInterventionsPreviously trained open-source logistic regression and random forest (RF) prediction algorithms were used to calculate a probability index (PI) for each infant for the occurrence of HIE.Main outcomeValidation of a machine learning algorithm to identify infants at risk of HIE in the immediate postnatal period.Results1081 had a complete data set available within 1 hour of birth: 76 (6.95%) with HIE and 1005 non-HIE. Of the 76 infants with HIE, 37 were classified as mild, 29 moderate and 10 severe. The best overall accuracy was seen with the RF model. Median (IQR) PI in the HIE group was 0.70 (0.53–0.86) vs 0.05 (0.02–0.15), (p<0.001) in the non-HIE group. The area under the receiver operating characteristics curve for prediction of HIE=0.926 (0.893–0.959, p<0.001). Using a PI cut-off to optimise sensitivity of 0.30, 936 of the 1081 (86.5%) infants were correctly classified.ConclusionIn a large unseen data set an open-source algorithm could identify infants at risk of HIE in the immediate postnatal period. This may aid focused clinical examination, transfer to tertiary care (if necessary) and timely intervention.
Effect of intravenous methylprednisolone on serum antibody levels in thyroid eye disease
Authors: Lee Chaeyeon , Lee Jung Eun , Kim Kyunga , Woo Kyung In 
Published: September 2024

Background/aimsWe evaluated longitudinal autoantibody changes after intravenous methylprednisolone (IVMP), compared them with those in untreated patients and identified prognostic factors for treatment response.MethodsIn this single-centre, retrospective, observational study, a total of 163 individuals diagnosed with moderate-to-severe thyroid eye disease were enrolled and followed for 12 months. Depending on whether IVMP was administered, we divided the patients into treatment and control groups. Based on the effect of IVMP on TSH receptor (TSH Rc) antibody level, we divided the patients into Ab declined and Ab not declined groups.We evaluated the time, group and interaction associations with the longitudinal autoantibody titres over 12 months using generalised estimating equations. Using multivariable logistic regression, we investigated the prognostic factors for a poor response to IVMP.ResultsIn the IVMP group, the TSH Rc antibody (Ab) titre decreased rapidly for 6 months and then decreased slowly until 12 months, becoming similar to the control group at 12 months. This suggests a difference in the decreasing pattern over time between the IVMP and control groups (group and time interaction p=0.029). Total cholesterol (OR 1.0217 (95% CI 1.0068 to 1.0370), p=0.0043) was a significant prognostic factor for the steroid response. The threshold total cholesterol value to distinguish between Ab declined and Ab not declined was 186 mg/dL.ConclusionIVMP significantly decreased the TSH Rc Ab level for the 3 months after treatment, compared with the no-treatment group, but the groups did not differ significantly after 12 months. Patients with high total cholesterol levels generally showed a poor response to IVMP.