bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fresh Air Flow Required to Maintain Safe Carbon Dioxide Levels and Provide a Breathable Air Environment in a Refuge Alternative
Authors: DeGennaro Cory , Yan Lincan , Yantek David 
Published: January 2022

Abstract
Federal mining regulations in the United States mandate that underground coal mines install refuge alternatives (RA) for miners to seek refuge after an inescapable disaster. RAs are required to isolate and protect occupants from hazardous conditions and to provide a life-sustaining, breathable air environment for a minimum of 96 hours. According to federal RA regulations, an RA’s oxygen levels (%O2) must be maintained between 18.5%–23% with carbon dioxide levels (%CO2) less than 1%. Once an RA is occupied, due to human breathing, the %O2 can decrease, and %CO2 levels can increase quickly. One method of providing an RA with a breathable air environment is to use a borehole air supply (BAS) to provide fresh air from the surface, purge existing harmful gases, and prevent harmful gas build-up. RA regulations require air supplies to provide air at 12.5 cubic feet per minute (cfm) per person. To investigate the minimum fresh air flow (FAF) rate needed to maintain interior %O2 and %CO2 within the mandated ranges, researchers conducted testing in a modified shipping container that represented the volume of an RA. During these tests, propane (C3H8) combustion and additional CO2 supplied from cylinders were used to match human O2 consumption and CO2 generation. The FAF rate supplied to the shipping container was varied to determine the minimum FAF rate required for the %CO2 inside the shipping container to stabilize below 1%. The test results showed that the minimum FAF rate was between 1.76–2.12 cfm per person. Therefore, the mandated per-person FAF rate provides a 6x–7x safety factor. Test results also showed that the %O2 range requirement was satisfied for the entire range of tested FAF rates from 1.76–12.5 cfm per person.
In this paper, researchers from the National Institute for Occupational Safety and Health (NIOSH) provide a repeatable test method that can be used to evaluate the FAF rate versus interior gas concentrations (%CO2 and %O2) for various occupancy levels to ensure a breathable air environment within a refuge alternative. This paper also discusses federal RA regulations and previous NIOSH research. Additionally, this paper provides an experimental concept and set-up description, including the C3H8 combustion and supplemental CO2 delivery with gas flow rates used to simulate human breathing, data collection sensors, laboratory modifications, and safety measures. Lastly, the paper discusses test results, including the amount of time taken to reach hazardous interior %CO2 and %O2, as well as %O2 and %CO2 resulting from several FAF rates that have been used to validate a predictive model. This test method could be adopted to evaluate breathable air environments in refuge alternatives and confined enclosures in various industries.
Resistance Heat Assisted Friction Element Welding
Authors: Grimm Tyler J. , Parvathy Gowtham V. , Mears Laine 
Published: January 2022

Abstract
The lightweighting of vehicle structures has become imperative in order to further improve efficiency within the transportation industry. One method of lightweighting is through the extensive use of multiple materials, offering the ability to selectively add strength where needed while eliminating the addition of extraneous mass. Though effective in design, multi-material automotive structures can be difficult to manufacture. One challenge which arises is the joining of these structures, which often cannot be achieved through traditional methods. Friction element welding (FEW) is a process capable of joining aluminum sheets to a steel substrate.
In this process, the aluminum material flows around the fastener shaft by applying an axial load and high rotational speeds. However, when joining high-strength aluminum alloys, this flow becomes diminished due to these materials’ relatively low ductility, resulting in the formation of sharp edges which protrude from the head of the fastener that introduce irregularities and potential contamination. These protrusions, termed chips, accelerate corrosion and are a significant defect. In a previous study, thermal assistance was confirmed as a viable method of reducing chipping by improving the flow of aluminum. An application method for such thermal assistance is developed and tested herein, which utilizes a direct electrical current applied locally to the joint region. The temperature rise was simulated and determined experimentally using a prototype modified downholder. Electrical heating was found to be a viable method of thermal assistance only when forced cooling of the electrodes is used.
Probabilistic Performance Evaluation and Optimization of Medical Plastic Moulded Components Subject to Large Scale Production
Authors: Brix Nerenst Tim , Ebro Martin , Nielsen Morten , Bhadani Kanishk , Asbjörnsson Gauti , Eifler Tobias , Lau Nielsen Kim 
Published: January 2022

Abstract
A new medical device can take years to develop from early concept to product launch. The long development process can be attributed to the severe consequences for the patient if the device malfunctions. Three approaches are often combined to mitigate risks: rigorous simulation and modeling, physical test programs, and Failure Mode Effect Analysis (FMEA) — all of which are time-consuming. Physical test programs are often carried out on prototype components from the same batch and, therefore, limited in revealing the actual distribution of performance. The risk probabilities are subsequently based on educated guesses. Furthermore, simulation and modeling are usually performed on nominal geometry — not accounting for variation — and only provide a safety factor against failure. The traditional use of safety factors in structural analysis versus the probabilistic approach to risk management presents an obvious misfit. Therefore, these three approaches are not ideal for addressing the two key questions that the design engineer has: 1) How often will the design fail, and 2) How should the design be changed to improve robustness and failure rates. The present work builds upon the existing Robust and Reliability-Based Design Optimization (R2BDO) and adjusts it to address the key questions above using finite element analysis. The key feature of the new framework is the focus on minimal use of computational resources while being able to screen feasible design concepts early in the embodiment phase and subsequently optimize their probabilistic performance. A case study in collaboration with a medical design and manufacturing company demonstrates the new framework. The case study includes FEA contact modeling between two plastic molded components with twelve geometrical variables. The optimization focuses on minimizing the failure rate (and improving design robustness) concerning three constraint functions (contact pressure, strain, torque). The study finds that the new framework achieves significant improvements to the component’s performance function (failure rate) with minimal computational resources.
Additively Manufactured Two-Phase Heat Exchanger Integrating PCMs for Spacecraft Thermal Management
Authors: Kabir Mehdi , Gemeda Takele , Preller Evan , Mohammed Raid , Xu Jiajun 
Published: January 2022

Abstract
For spacecraft thermal management systems, it is crucial to diminish the overall mass of on-board thermal storage system and minimize the temperature fluctuations when the environmental temperature changes drastically. Since there is no atmosphere in outer space, heat can only be rejected to space using radiation (e.g., radiators). By engaging and integrating phase-change materials (PCMs) into a passive two-phase heat exchanger, the radiator can be designed and sized for the average rather than the maximum power. To meet the NASA needs, the prototype developed and fabricated in the present study is a novel two-phase heat exchanger that integrates PCMs within a vapor chamber through multiple thin drawers loaded with bulk PCM. The entire solid structure of the prototype is manufactured additively using Maraging Steel with the Direct Laser Metal Sintering (DLMS) technique. The chosen working fluid is Methanol to undertake two-phase heat transfer via saturated vapor from the heated surface of evaporator to the condenser surface, and the condensate then returns back to the heated region and keeps recirculated using the capillary pumping pressure performed by the wick structure without any reliance on the gravitational magnitudes. Depending on the heat sink temperature and PCM melting temperature, the developed heat exchanger can either function as a thermal capacitor or a two-phase heat exchanger with thermal storage capability, that is, two modes of operation to be engaged within the spacecraft’s launching/landing stages or orbiting stage, respectively. In the present study, the geometry and number of the PCM-loaded drawers enclosed inside the heat exchanger’s casing are optimized based on the mass ratio (the ratio of PCM mass to the total heat exchanger mass), additive manufacturing (AM) constraints, and total thermal resistances imposed on the system for either of the operation modes.
Dynamic Response Evaluation of Platinum Thin Film Gauge
Authors: Alam Tanweer , Kumar Rakesh 
Published: January 2022

Abstract
The temperature gauge with quick response characteristic and ability to provide highly precise instantaneous temperature data is usually selected for the systems with minimal time available for the measurement. Thin-film gauges are best suited for such transient measurement. In this paper, the convective environment created by blower-heater arrangement is used to evaluate the dynamic response of platinum thin-film as a heat flux gauge. The in-house fabrication of the gauge is made by using quartz as a substrate and a thin-film of pure platinum acting as a sensing element. The response is measured to the step changes for the enforced convective heat flux. The heat flux value is inferred from transient temperature data from one-dimensional heat conduction model subjected to a semi-infinite body. Numerical analysis is also performed. The similarities of experimental and numerical results authenticate the experimental set up as well as the thin film gauge efficacy.
Verification of Additive Manufacturing Products Using Model Registration and Template Matching Techniques
Authors: Davis Lenning A. , Donnal John S. , Kutzer Michael D. M. 
Published: January 2022

Abstract
This paper presents a method of verifying Additive Manufacturing (AM) products using computer vision, specifically model based registration. The use of AM increasingly widespread, with systems being used by private households, educational institutions, commercial enterprises, and government agencies. With this increased adoption of AM comes cyber-physical risks and an ever-increasing potential for part defects. To address this growing issue, this method seeks to verify product quality using model-based registration and image comparison techniques. Using the “.gcode” file for a given part, and an estimate of the extruder’s pose relative to the product, we create a simulated image of the desired product. This simulated image can be compared to images of the physical part collected during the printing process to verify overall part quality. This paper presents two methods of image comparison to identify discrepancies. Preliminary results yield successful image segmentation and detection of structural defects.
Investigations to Consider Thermal Interactions Between Spatially Separated Subsystems: Concept of a Thermal Coupling System for X-in-the-Loop Test Benches
Authors: Leitenberger Felix , Steck Michael , Gwosch Thomas , Matthiesen Sven 
Published: January 2022

Abstract
The system behavior of new products can be validated with X-in-the-Loop (XiL) test benches. The potential spatial separation of the subsystems on those test benches interrupts the heat flows between the subsystems. This can lead to a different temperature distribution compared to the original assembly situation. It may change the system behavior because many functional relevant properties are temperature-dependent and the thermal interactions are not considered. The reliability of the test results concerning the system behaviour of the overall system is therefore reduced. This paper describes the investigations to consider thermal interactions between spatially separated subsystems on XiL test benches. A concept of a thermal coupling system for the transfer of thermal interactions by heat conduction is modeled. The model setup with sensors, actuators and control systems is described in detail. A simulation is used to check its feasibility for a future physical setup. The results of the simulation show small temperature deviations compared to the situation with spatially separated subsystems. With such a thermal coupling system, thermal interactions by heat conduction between spatially separated subsystems can be transferred. It is able to improve the product validation by using it on XiL test benches.
Yttrium Decorated on Thin Borophene Defect for Hydrogen Storage: A First Principles Study
Authors: Ledwaba Kabelo , Karimzadeh Sina , Mkhohlakali Andile , Jen Tien-Chien 
Published: January 2022

Abstract
Borophene- two-dimensional (2D) is an emerging material that has engrossed much consideration in the field of energy materials They exhibit a broad range of various incredible properties, which were considered as ground-breaking for different application such as batteries, superconductors, anode materials for photochemical water splitting, and biosensors and super capacitors. Yttrium-decorated borophene (Y-borophene) as a carrier for hydrogen storage have been studied. DFT calculations based on the Dmol3 code were used to investigate adsorption energy and optimal geometry for hydrogen adsorption on pure borophene and Y-borophene. Isolated yttrium atom on borophene have studied for defect. For Y-borophene, the yttrium atom can adsorb eight hydrogen molecules with average adsorption energy of 0.461 eV/H2 which has increased adsorption energy by 33% compared to the pure borophene with the same condition. The hydrogen storage capacity of this material is 15.23 wt.%, demonstrating Y-borophene as a promising candidate for hydrogen storage. In addition, the density of states plots (PDOS) is presented to further comprehend the electronic structures and bonding nature.
Effect of Cyclic Compression on Mechanical Behavior of Ceramic-in-Polymer Composite Electrolytes for Lithium-Ion Batteries
Authors: Mulay Nishad , Oh Dahyun , Yoon Dan-Il , Lee Sang-Joon (John) 
Published: January 2022

Abstract
Composite polymer electrolytes (CPEs) for lithium-ion batteries provide an effective balance of ionic conductivity, mechanical robustness, and safety. Loss of charge capacity, however, is caused by several contributing factors. In this work we specifically examine mechanical changes in the composite electrolyte layer. We apply cyclic compression to mimic stress cycling that is caused by asymmetric volume changes during charging cycles between anode and cathode. Using a representative composite electrolyte formulation consisting of Li6.4La3Zr1.4Ta0.6O12 (LLZTO) at 10 wt. % in polyethylene oxide (PEO) with bis(trifluoromethane) sulfonimide (LiTFSI), we experimentally measure stress-strain characteristics, stress relaxation time, and cyclic compression of a composite electrolyte. We also examine the effect of particle size, by comparing 500 nm vs. 5 μm sizes. At 15% compressive strain, the addition of 500 nm particles increased strain energy density (SED) by a factor of 2.6 and the addition of 5 μm particles increased SED by a factor of 2.9. Both particle sizes showed similar relaxation time constant, but the 5 μm particles showed tighter repeatability than the 500 nm case. Both compositions exhibited continual decline in peak stress beyond 500 cycles of compression at 15% strain. These experiments reveal insights into how cyclic loading can alter the mechanical response of a composite electrolyte, and thereby contribute to the broader understanding of electrochemical and mechanical coupling in lithium-ion batteries.
Conceptual Design of Temperature-Controlled Fueled-Salt Irradiation Experiment to Support Demonstration of Advanced Nuclear Reactors
Authors: Abou-Jaoude Abdalla , Chandler James , Core Gregory , Davies Kim , Downey Calvin , Phillips William , Tan Chuting , Wilson Stacey 
Published: January 2022

Abstract
Irradiation testing of fuel-bearing molten salts is critical for supporting the development and demonstration of molten salt reactors (MSRs). These experiments can inform several important reactor design and safety parameters, including source term modeling, the evolution of thermophysical properties with burnup, and the degradation of structural materials under reactor-relevant conditions. Idaho National Laboratory is designing an instrumented and heated high-temperature molten-salt-fueled irradiation capsule to study the behavior of the fuel salt during in-pile irradiation. This paper details the neutronics, thermal, and mechanical analyses performed to date. Parametric studies were performed to assess a range of materials, different experiment dimensions, two in-reactor positions, and the fuel enrichment used. The principal recommendations are to select a peripheral reactor position in order to alleviate neutronic constraints, a thin salt annulus to achieve thermal design objectives, and high-temperature alloys that provide additional safety margins.
Valve-Enabled Sample Preparation and Isothermal Amplification for SARS-CoV-2 Detection at the Point-of-Care
Authors: Manzanas Carlos , Alam Md. Mahbubul , Loeb Julia C. , Lednicky John A. , Wu Chang-Yu , Fan Z. Hugh 
Published: January 2022

Abstract
Early and accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the point-of-care (POC) is crucial for reducing the transmission of coronavirus disease 2019 (COVID-19). To address this need, we have developed a valve-enabled lysis, paper-based RNA enrichment, and RNA amplification device (VLEAD) for detecting SARS-CoV-2. We have combined VLEAD with a smart coffee mug for sample preparation, nucleic acid isothermal amplification, and colorimetric detection using a smartphone camera or a naked eye. VLEAD enables two critical functions required for POC testing: sample preparation and detection. Since the reagents can be pre-packaged in the device, all operational steps can be carried out at POC. We have demonstrated the functions of the device by analyzing samples spiked with heat-inactivated SARS-CoV-2, which were obtained from BEI Resources. This rapid and highly sensitive POC platform for SARS-CoV-2 detection has a potential to help reduce COVID-19 transmission.
A Hybrid Methodology for Risk Mitigation During Development of Safety-Critical Autonomy Features
Authors: Zarifian Pez , Garikapati Divya , Pralle Julia , Dawson Jennifer , Hubmann Constantin , Reiff Brielle , Tam Raymond , Gaddamadugu Gopi 
Published: January 2022

Abstract
As a relatively nascent field, engineers developing autonomous vehicle (AV) technologies need frequent performance feedback on whether algorithms are performing the driving task competently. Further, because of the complexity of AV systems, it is often lower risk to frequently test small, incremental changes instead of delaying testing and accumulating a large number of changes to the algorithms. While simulation and closed course testing are useful and critically important tools, ultimately driving on public roads is necessary to truly understand system performance and identify potential edge cases. Maintaining a high safety standard to protect all road users during continual public road testing is of paramount importance for the AV industry.
The Waterfall methodology has a demonstrated track record for product safety, but does not provide much flexibility for prototyping and incremental testing. The Agile methodology is famous for enabling rapid development and incremental rollouts, but does not possess any inherent safety gates. When it comes to developing complex safety-critical autonomy features, particularly for dynamic environments such as in the case of autonomous vehicles, neither method is fitting.
This paper presents a hybrid methodology that strikes a balance between safe and rapid development of autonomy features for the AV industry.
Innovation in Hydrotesting Above Ground Pipes: Analytical Solution via Integral Transforms for Discerning Test Fluid Temperatures Subject to Ambient Temperature Variations
Authors: Isaza Pedro A. , Botros Kamal K. 
Published: January 2022

Abstract
Hydrostatic testing for strength and leaks of newly constructed pipelines are required by code. However, for exposed pipes challenges are encountered since ambient conditions can influence pressure responses. Additionally, there is uncertainty as to whether the temperatures measured at a pipe’s outer wall, which are used to compute the expected pressure profiles, are representative of the testing fluid. To help bridge the gap, this work demonstrates the use of integral transforms for analytically solving the non-homogeneous 1D transient equations prescribed for the fluid temperature inside a cylindrical pipe. The solution identified provides sufficient generality to accommodate arbitrary initial conditions and ambient temperature variations. Furthermore, a rate of change function is formulated which enables a direct assessment of the temperature equality assumption between the fluid and the pipe wall. The validity of the solution is then substantiated by demonstrating excellent agreement with results reported in the literature (for a scenario describing typical hydrotest conditions). From the results obtained it can be observed that as the Biot number increases the temperature equality assumption begins to break down. Finally, a simplified expression for the relationship between the rate of change of the ambient air and the average fluid temperatures was formulated for this special scenario, which again showed agreement with the results in the literature.
Modular Printed Powered Air Purifying Respirator
Authors: Brown J. , Clifford M. , Magana J. , Salman M. , Tran D. 
Published: January 2022

Abstract
At present, the world is undergoing a pandemic spawning from the advent of a new coronavirus outbreak known as COVID-19. As a result, hospital staff, paramedics, first responders, and the general world population have been forced to wear personal protective equipment (PPE) and take special measures to prevent catching the virus. Furthermore, because of this necessity, increasing demand on the PPE supply chain has generated many shortages, especially seen in masks designed to stop the inhalation of COVID-19 particles in the air. This inspired our group to design something that could help make PPE more accessible and affordable for the average person. The proposed is an almost entirely 3D printed design to help keep costs down and make it simplistic, such that anyone with a 3D printer has the potential to duplicate it. We hope that with the design, we can help combat the shortage and keep more people safe from COVID-19.