bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing and Analysis of Mechanical, and Corrosion Properties of 2024 Aluminum Alloy Using Friction Stir Processing
Authors: Dhamodaran Shanthakumar , Velukkudi Santhanam Senthil Kumar , Kuppusamy Raman 
Published: February 2024

Abstract
The friction stir method, an emerging metalworking technique, has the ability to locally and deliberately change the microstructures in the near-surface layers of a treated metallic component. A significant amount of material is permanently deformed, mixed, and exposed to heat in the treatment zone as part of this surface modification procedure, which significantly alters the material’s microstructure. The treated zone is distinguished by a recrystallized fine-grained structure. This strategy was developed from friction stir welding, a type of solid-state joining technique that employs friction to permanently bond metals. The friction stir technique is used to preserve the bulk qualities of the base material while further enhancing resistance to wear, creep, and fatigue. Because of its high specific strength, lightweight, and machinability, There are numerous applications for aluminum and the associated alloys. The AA2024 is one of the strongest aluminum alloys, and it will contain copper as a primary alloying element. Owing to its substantial strength-to-weight ratio, The AA2024 is a material utilised in the aviation industry, notably fuselage structures and orthopaedic equipment. The microstructure and mechanical characteristics of the treated zone can be manipulated by adjusting the tool design and FSP parameters. The current effort tries to determine the best range of processing parameters by altering the tool rotational speed, traverse speed, and applied force. This experiment included tool rotational speeds of 1000, 1300, and 1600 rpm, tool traverse speeds of 15 mm/min, 30 mm/min, and 45 mm/min, and applied loads of 8 kg, 10.25 kg, and 12.5 kg. The experiment is designed using the Box-Behnken optimization technique, which considers three factors at three different levels. To improve material flow for the reinforcing particles, a cylindrical pin of H13 tool steel bearing a hardness of 60 HRC is designed and produced. The ultimate tensile strength (UTS) of FSPed AA2024 samples was tested using a universal testing machine in accordance with ASTM E8 standards. The Vicker’s hardness testing machine was used to perform microhardness tests as per ASTM E384 standards to determine the hardness of FSPed AA2024 samples. By comparing the sample weights before and after testing, the corrosion rates had been determined using the immersion corrosion testing method. The 2D-surface roughness tests were carried out using Taylor Hobson’s Surtronic S-128 roughness testing machine to determine the roughness value of FSPed AA2024 samples. The most effective friction stir process variables are chosen using Grey Relational Analysis (GRA), which is applied to the outcomes of many response tests. At a 95% confidence level, the most important contributing friction stir process factors are identified using an analysis of variance (ANOVA).
Naturally-Circulated Waste Heat Recovery Equipment Driven by Flue Gas Dumped at a Stack and Performance Improvement
Authors: Lee Jaedal , Yi Junseok , Cho Seongkuk , Jeon Soohwan 
Published: February 2024

Abstract
Here, waste heat recovery equipment driven by flue gas dumped at a stack is introduced in order to perform a task to augment energy saving and combustion efficiency in industrial furnaces. The main structure is composed of an evaporator and a condenser as a pair unit for natural circulation of steam as a working fluid. The evaporator and condenser are helical solid finned tubes erected vertically in which the fin side fluids make a cross flow. Steam boiled by the flue gas that sweeps over the evaporator finside condenses into water liquid along the condenser tubeside. Air used for combustion is heated by absorbing latent heat release issuing from steam condensation in the condenser. Thermal robustness and stability tests were carried out to have a long-term operation capability and experience, and secure driving characteristics with which future commissioning scenario will be composed. Two operation modes were performed for thermal efficiency evaluation: one for a baseline with plain tubes in the condenser, and the other with hiTran inserts (product of CalGavin Co., Ltd. [1]) in the condenser. The hiTran was half installed from upstream of the condenser. The hiTran mode has a better thermal efficiency slightly over 2% than that of the baseline mode near at a flue gas inlet temperature of 300°C. By leading to disturbing step-wisely downward-growing boundary layer along the condenser tube surface, the insert as an obstacle against the developing boundary layer seems to be contributable to thermal efficiency augmentation. On the other hand, there appears more subcooled steam condensate at the condenser outlet such that more heat load is assigned to the evaporator. The subcooled heat loads that are allocated to the evaporator for the baseline mode and the hiTran mode are assigned to 5.7% and 12.9%, respectively.
A Literature Review of Automated Fault Detection and Diagnostics for HVAC Systems
Authors: Allen-Magande Hugh , Khazaii Javad , Esmaeili Amin 
Published: February 2024

Abstract
Modern HVAC systems are significant energy consumers and major contributors to environmental pollution. These systems consume around 52% of the total U.S. energy used in commercial buildings on average; withal, the air conditioning industry is responsible for approximately 4% of global greenhouse gas emissions annually. Previous research has targeted ways to improve the energy efficiency of HVAC systems and reduce their environmental impact via enhanced control algorithms. However, because maintenance teams execute HVAC system diagnostics offline, this hinders detecting and correcting any system malfunctions or underperformance immediately. Currently, innumerable research is underway that focuses on improving automated fault detection and diagnostics (AFDD) algorithms for HVAC systems to reduce operating costs and improve efficiency and indoor air quality (IAQ). This study aims to synopsize the typical fault detection and diagnosis systems being developed for commercial and industrial buildings. Still, the authors believe there is a need for less expensive AFDD algorithms for HVAC systems, as well as common standards or protocols for FDD development. Machine learning may be the best approach to achieve a more dynamic system that adapts to changing situations independently, which could be the key to developing an adaptive HVAC AFDD system using Artificial Intelligence.
Finite Element Analysis and Fatigue Life Prediction of a Laterally Conducting GaN-Based Power Package Under Thermal Cycling
Authors: Zaghari Pouria , Sinha Sourish S. , Ryu Jong Eun , Franzon Paul D. , Hopkins Douglas C. 
Published: February 2024

Abstract
Thermal fatigue life analysis of GaN packages is an important consideration that affects the reliability and durability of electronic devices. In this paper, the fatigue life assessment of a GaN laterally conducting power packaging, including SAC305 and Sn63/Pb37 solders was conducted using the finite element analysis (FEA) method. The thermal cycling loading was chosen based on JEDEC Standard JESD22-A104D condition M. With temperature cycling from −40°C to 150°C. To simulate the viscoplastic behavior of solder materials under thermal cycling, the Anand constitutive model was adopted. Coffin-Manson, Engelmaier, and Solomon empirical models were utilized to predict the cyclic life of the package based on stress and strain distribution in the solder layers. Results showed that the critical solder joint location of the failure was in the SAC305 solder. The maximum inelastic strain range of SAC305 solder was calculated to be 0.023697. The fatigue life prediction of the module showed that the Engelmaier model was the most conservative model resulting in a fatigue life of 136 cycles.
Numerical Investigations of Shock Wave Reactors Employing Head-On Colliding Shock Waves
Authors: Akbari Pejman , Tüchler Stefan , Copeland Colin D. , Shaffer James , Askari Omid 
Published: February 2024

Abstract
This study investigates the feasibility of hydrogen production using gasdynamic compression heating, focusing on high temperatures (&gt; 1500 K) shock wave reactors with sufficient residence time for high fuel-to-hydrogen yield. The study compares two designs, an eight-port, and a twelve-port shock wave reactor employing head-on colliding shock waves. The novel twelve-port shock wave reactor design uses multiple pressure-reducing stages when releasing the driving gas from the reaction channels. In comparison, the eight-port design uses a single step to remove the driving gas. The novel twelve-port process is observed to increase the efficiency because the rate of entropy generation from viscous and thermal dissipations is lowered. The numerical results show that the stage-expansion design (twelve-port design) is more efficient than the single-expansion architecture (eight-port design) despite its system complexity. This finding confirms the theoretical principles and suggests that shock wave reactor designs could benefit from multi-stage expansion (and compression) process. The study provides valuable insights for the design and optimization of shock wave reactors for fuel pyrolysis process.
Numerical Studies of Hemodynamic Flow in the Aortic Vessel of Patients With Congenital Heart Disease
Authors: Jack Justin T. , Jensen Morten , Collins Thomas , Chan Frandics Pak , Millett Paul C. 
Published: February 2024

Abstract
The most prevalent type of birth defects globally are congenital heart defects (CHDs), requiring knowledge of intracardiac blood flow for their evaluation and progression. However, imaging techniques such as four-dimensional magnetic resonance and blood speckle imaging continues to lack the resolution required to extract flow data in patients with elevated flow velocities. Aortic stenosis (AS), a left ventricular outflow tract anomaly frequently associated with Williams syndrome, requires better tools for severity assessment than clinical findings and pressure gradient assessments, as these can be influenced by transient physiology and the stage of the disease. A computational framework was developed to evaluate intracardiac blood flow in a patient with an extreme aortic defect using the coupling of zero-dimensional (0D) lumped parameter models and pre- and post-intervention patient-specific reconstructed geometries to perform computational fluid dynamic (CFD) simulations. The framework allows for the analysis and visualization of complex blood flow patterns, providing insight into changes in geometry and flow dynamics affecting cardiac function. The framework aims to evaluate the effectiveness of the surgical procedure in correcting the defective aorta.
Fabrication of Conductive Patterns by Laser Irradiation and Thermal Treatment of Silver Nanoparticle Inks for Flexible Printed Electronics
Authors: Chowdhury Rajib , Courville Justin , Jang SeonHee 
Published: February 2024

Abstract
A combination of laser irradiation and thermal treatment of a silver (Ag) nanoparticle (NP) ink was introduced to produce conductive patterns for flexible electronics applications. All of the patterns were laser irradiated followed by thermal treatment. The Ag patterns sintered under formic acid (FA) exhibited increased necking and coalescence. The sheet resistance of the patterns was influenced by sintering atmospheres and the Ag pattern sintered in the FA demonstrated the lowest value of 0.0016 Ω/sq. The hardness values were varied with different sintering atmospheres and the Ag pattern sintered in the FA exhibited the highest hardness value of 4.38 N/mm2. The patterns sintered in different atmospheres exhibited a weight loss in the range of 5.73–7.62% and the roughness varied from 67.95–211.3 nm. This can be attributed to the presence of organic residues after sintering and the degree of NP agglomeration. After conducting folding tests on Ag patterns for up to 50 cycles, all atmospheric conditions exhibited an increasing trend in resistance ratio with each subsequent folding cycle. The Ag patterns that were sintered under air and FA exhibited the lowest and highest resistance ratios of 1.57 and 8.58, respectively.
Prediction of the Maximum Energy Harvest Considering Year-Around Sky Coverage Conditions and Optimized Setup Angles of Fixed PV Panels
Authors: Gwesha Ammar Omar , Li Peiwen , Alfulayyih Yasir Mohammed 
Published: February 2024

Abstract
The installation of solar photovoltaic (PV) panels is growing globally as the international community is on track to transition from fossil fuel energy to clean and sustainable resources of energy such as solar energy, wind energy, hydropower, and bioenergy. Among various renewable energy technologies, the capacity of power generation using solar PV has grown dramatically in recent years around the world. With more and more fields and building roofs covered with PV panels, setting up solar panels with flexibility at various idle surfaces becomes important for cost reduction. Regarding making use of idled areas and surfaces for solar panels, it is also important to have a tool to predict the energy harvest and the cost in order to attract more and more customers. In an attempt to maximize the irradiance fallen on a PV panel of various orientations, the present study provides a general model to predict the energy harvest and also the optimal tilt angles and orientation of the panels when needed. The analysis can accurately calculate the instantaneous sunray vector and solar panel normal vector using Solar Position Algorithm to account for the “cosine” effect of the angle of incidence. And more importantly, weather conditions or clouds coverage conditions are also combined in the calculation for precise energy prediction. The solar energy received per unit area of a PV panel in every 5 minutes is summated or integrated for daylong period from sunrise to sunset considering 21 years of averaged cloud-cover meteorological data. The model presented here is employed to two examples of geographical sites at north and south hemispheres and can be applied to any location around the world. The results for the City of Tucson Arizona USA show that the amount of yearly solar energy captured by a solar tracking panel is 3619.32 kWh/m2, whereas the annual solar energy received by an optimally tilted solar panel of a slop same as the local latitude could reach to 2206 kWh/m2 (60.9% of that from a fully tracking system). The findings also indicate that by optimally adjusting the tilt angle two times a year, four times, and monthly, the yearly solar energy accumulation can be 65.534%, 65.525%, and 66.515% of that of a system with tracking, respectively. In the absence of rooftop or ground installation options, the study reveals that vertically installing PV solar panels on walls due south would attain about 32% of the annual solar collection compared to a fully tracked system.
Vibration Phenomenon of Infants by Using a Baby Carriers
Authors: Iguchi Ryogo , Ota Shinichiro , Asano Katsuhiro 
Published: February 2024

Abstract
In this study, we focused on the vibration phenomenon of infants when using baby carriers. Although several safety standards for baby carriers are available, they do not consider the physical burden caused by the vibration phenomenon of infants, which may cause excessive vibration load to infants depending on the conditions of use.
The aim of this study was to clarify the vibration phenomenon of infants when using baby carriers. We conducted two measurement experiments: one was a vibration experiment using a vibration exciter and the other was a walking experiment in which participants walked at different speeds using a baby carrier and an infant dummy.
In the vibration experiment, regardless of the difference between the infant dummy and baby carrier, the amplitude of acceleration on the shaker and participant, and at each measurement point between the participant and infant dummy, varied less than 0.01 mm at 1–2 Hz, indicating that the baby carrier did not amplify the vibration. However, the acceleration amplitude was amplified when the frequency band became larger than 2 Hz. In the walking experiment, the measured acceleration amplitude peaked at 1.2 Hz at 70 BPM and at 1.5 Hz at 90 BPM, confirming that it was strongly influenced by the walking cycle.
Determination of Renewable Energy Capacity by Stochastic Optimization
Authors: Manoharan Yogesh , Headley Alexander John 
Published: February 2024

Abstract
The installation of renewable energy sources is becoming more common for those seeking to become self-sufficient in their energy requirements, minimize electricity costs, or limit their carbon footprint. Other technologies such as energy storage systems (ESS) or demand side management (DSM) systems are also being adopted alongside renewables to manage the intermittent nature of renewable energy and maximize potential savings. For behind-the-meter customers, significant savings can be achieved with a combination of renewable energy with battery energy storage systems (BESSs). However, batteries and renewable energy require large capital investments. There exists an interplay of benefits, costs, and generation needs that makes it is difficult to determine the proper size of renewable energy sources for maximum impact. Hence in this study a methodology for sizing renewables, batteries and optimizing savings is presented. Given the intermittent nature of renewables, stochastic methods are added to understand the impact of variability on planning procedures.
For this study both wind and solar power sources are considered. Given their significantly different generation profiles, the effect on system designs using a combination of both power sources is explored. The size of renewables and BESS are estimated using a stochastic optimization program. This study will help to improve the understanding of BESS and renewable energy sources in maximizing the savings from an entire system. The stochastic optimization gives us estimate of renewable and BESS and insight on the impact of uncertainties present in the measurement of wind speed and solar radiation on the outcome of the optimization program.
Using High-Fidelity Time-Domain Simulation Data to Construct Multi-Fidelity State Derivative Function Surrogate Models for Use in Control and Optimization
Authors: Sundarrajan Athul , Herber Daniel R. 
Published: February 2024

Abstract
Models that balance accuracy against computational costs are advantageous when designing dynamic systems with optimization studies, as several hundred predictive function evaluations might be necessary to identify the optimal solution. The efficacy and use of derivative function surrogate models (DFSMs), or approximate models of the state derivative function, have been well-established in the literature. However, previous studies have assumed an a priori state dynamic model is available that can be directly evaluated to construct the DFSM. In this article, we propose an approach to extract the state derivative information from system simulations using piecewise polynomial approximations. Once the required information is available, we propose a multi-fidelity DFSM approach as a predictive model for the system’s dynamic response. This multi-fidelity model consists of summation between a linear-fit lower-fidelity model and an additional nonlinear error corrective function that compensates for the error between the high-fidelity simulations and low-fidelity models. We validate the model by comparing the simulation results from the DFSM to the high-fidelity tools. The DFSM model is, on average, five times faster than the high-fidelity tools while capturing the key time domain and power spectral density (PSD) trends. Then, an optimal control study using the DFSM is conducted with outcomes showing that the DFSM approach can be used for complex systems like floating offshore wind turbines (FOWTs) and help identify control trends and trade-offs.
Carbon Footprint of Electricity Generation in a Conceptual Bioenergy Power Plant With Carbon Capture and Storage
Authors: Nemer Martha , Duque-Rivera Jorge , Aviles Daniel , Salas Daniel , Ramirez Angel D. 
Published: February 2024

Abstract
This paper analyzes the efficiency of a BECCS (Bioenergy with carbon capture and storage) system as an energy generation carbon sink in Ecuador, conceptualizing a 20MW power plant whose energy source is eucalyptus wood and evaluating its carbon footprint with an attributional life cycle assessment (LCA). The paper presents the technical specifications of the equipment and the processes needed to carry out the operation. Aiming at a case study for Pichincha - Ecuador, the power plant will contribute 3.5% of the total energy needed to power the province. The selected region possesses a high concentration of optimal areas with adequate soil to plant eucalyptus, equivalent to 56% of the total available in Ecuador. The electricity generation system has a global efficiency of 33.3% without considering the internal consumption of equipment and 13.4% assuming all internal consumptions. The carbon footprint was determined using the OpenLCA software, previous work on LCA of electricity generation in Ecuador and commercial life cycle inventory databases. The result for the proposed system is −0,95 kgCO2/kWh, demonstrating that it delivers carbon-negative energy because the growth of the eucalyptus removed carbon from the atmosphere. In contrast, the traditional energy generation systems by steam generation using fuel oil combustion have a carbon footprint of 0,93 kgCO2/kWh.
Composites and Sustainability: What Is the State of the Art
Authors: Patton Ned 
Published: February 2024

Abstract
Sustainability in the Advanced Composites Industry means many things to many people. This paper addresses the current challenges and approaches to reaching the overall goal of sustainable composite materials. The discussion includes the state of the art in natural fiber and resin formulations, recycling composites after they have completed their useful life, research into the means of separating the fibers from the matrix plastics that bind them together, and reuse of the original constituents of the composite being recycled. The challenges are many since the resin formulations and the surface chemistry of the fibers is specifically tailored during manufacture to resist taking them apart. This paper, therefore, presents current methods for recycling, which are primarily grinding or chopping up the composite and reusing the chopped up composite in a lower performance material. It also presents current research areas that are attempting to recycle composites without creating excess greenhouse gases or hazardous chemicals, and chemical and thermo-chemical methods being proposed, some of which are in development, to render the resin or plastic binding the fibers together from a solid back into a liquid so that the fibers can be more easily removed without damaging them, making them available for reuse. The paper concludes with a description of what a Circular Economy means WRT advanced composites and what is needed to close the circle and make composites truly sustainable.