bluuebunny/crossref_metadata_2025 huggingface dataset:
Addressing Software/Hardware Challenges by Incorporating System Software Integrator Certification
Authors: Kemper Bart , Laplante Phillip A.
Published: February 2024

Software is embedded in most electromechanical systems and complex facilities and has changed our lives in the same way that electricity and the internal combustion engine once did. These changes are overwhelmingly beneficial, but recent events, such as the 737 MAX crashes and problems with autonomous vehicles, demonstrate the serious consequences of software failures. The challenges are greater than isolated incidents, however. Three quarters of software projects fail. There has been a 742% average annual increase in SCC attacks over the past three years for open-source software (OSS), in many cases costing millions per incident. There have been significant increases in cyber-attacks and ransomware incidents. Human threats are adaptive, pernicious, and persistent and two US presidents have issued Executive Orders regarding software-related threats to the nation. In response to these events, a task force within the National Society of Professional Engineers proposes the creation of a certified System Software Integrator (SSI) role — a person designated to take responsibility for a system in a manner similar to other professionals with “responsible in-charge” duties. This proposal has been championed by a multi-discipline team from diverse industries, including power generation, software development, and Artificial Intelligence development. The challenge of building critical embedded software systems is not a “software problem, “ but an “engineering problem” that goes well beyond writing lines of code. This is an engineering solution.
Engineering Education Projects: Thermal Imaging for Robotic Joining Operations
Authors: Mauk Michael G. , Senthilvel Kavitha Arjuna Kartihikeyan , Vasudevan Nijanthan , Tseng Tzu-Liang (Bill) , Chiou Richard Y.
Published: February 2024

We describe an undergraduate engineering project to give students hands-on experience and integrate diverse knowledge and skills in robotics, thermal imaging, rapid prototyping, machine learning and artificial intelligence, and plastics engineering, and materials testing. A robot is programmed for ultrasonic welding of 3D-printed or laser-machined plastic parts or soldering of components to printed circuit boards. The process is monitored with a thermal camera, and the infrared images and video are analyzed by machine learning and artificial intelligence algorithms for process optimization, based on criteria tensile strength and pressure leak tests. A pre-trained machine learning model can monitor and analyze the thermal joining processes.
Hydrates Based Carbon Capture System in Texas: a Techno-Economic Perspective
Authors: Acharya Palash V. , Bhati Awan , Bahadur Vaibhav
Published: February 2024

This work analyzes the techno-economic factors associated with the production of blue H2, and hydrates-based capturing of CO2 produced by sorption-enhanced steam methane reforming (SESMR) of methane from landfill gas (LFG) across various counties in Texas. The SESMR system is coupled with a hydrates-based carbon capture system, and the energy and cost of setting up and running such a hydrates-centered capture facility have been estimated. In doing so, the amount of water and energy required to compress and refrigerate the gas down to hydrate-forming conditions and the capital and operating costs involved in setting up and running such a facility are evaluated in detail. The cost of producing hydrogen (without the carbon capture system) from this analysis is estimated at $0.5/kg of H2. The total cost (CAPEX+OPEX) for capturing one metric ton of CO2 ranges from $96 (Harris County) to $145 (Brazoria County). Notably, adding a thermodynamic promoter such as Tetrabutylammonium bromide (TBAB) to the hydrate precursor mixture to achieve favorable thermodynamic formation conditions increases the overall cost ($107–$137/metric ton of CO2 captured). This can be attributed to the increased water requirement necessitating a higher number of reactors, higher refrigeration capacity, and labor costs. The minimum hydrogen cost required for a positive combined net present value (NPV) for a coupled SESMR + hydrate-based carbon capture system for a 30-year project duration is estimated at $0.9/kg and $2.4/kg of H2 for Harris and Brazoria counties, respectively. Furthermore, a 5-year payback period would require a minimum cost corresponding to $1.35/kg (Harris) and $4.95/kg (Brazoria) of H2, demonstrating that the coupled system would be economical only for counties that have a significant hydrogen production potential.
Concerns With Risk Distribution in Environmental Justice
Authors: Nelson Kevin , Kee Ernest
Published: February 2024

When engineers consider risk management, they have traditionally used a largely consequentialist framework in which the key consideration is the expectation value of total harm. However, as discussed by Hanson and by Cramer (in Lewens, 2007) non-consequentialist ethical theories have substantial support from philosophers and it is worth exploring the implications of those theories for engineering practice.

Though we can hardly survey all possible ethical theories, Kantian (deontological) and Rawlsian (justice-centered) theories are extremely prominent. One aspect those theories have in common is that they frown on, if they do not outright forbid, the imposition of risks on people who do not agree to them. This is a view that has been further elaborated in much of the recent work done on environmental justice (Coolsaet, 2020).

One implication is that risks should often be categorically reduced to a de minimis level. It is widely held that justice, unlike probability, does not come in degrees. If that is the case, then it is arguable that justice requires not merely the reduction of the expectation value of harm, but that some kinds of harm must be avoided altogether if at all possible.

The obvious objection to that claim is that risk can never be avoided entirely. One response to that objection is that what really matters is the risk as perceived by those who are required to be subjected to it, or by those with few alternatives to being subjected to it. Related to that point, we must remember that for events lacking a large sample, exact probabilities are not known and must be estimated. Even if we believe we have a good estimate for the probability of some adverse outcome, we should have the humility to respect other estimates. Quantitatively, this can be addressed via several mathematical tools for imprecise probabilities, such as upper and lower probabilities (Walley, 1991).

A further implication that is associated especially with Rawlsian theories is that we must be concerned not only with the total burden of risk, but with its distribution. In particular, the interests of underprivileged groups require consideration. A maximin principle may be applicable, in which we are required to maximize the interests of those who are currently least well off.

In this article, the limitations of engineering information that can be supplied to political decision-makers is explored against well established ethical theory, especially the theories that have been associated with consequentialism and deontology.
Weaving Digital Storytelling in Introductory Design Thinking Course for Mechanical Engineers
Authors: Condoor Sridhar S.
Published: February 2024

Design is at the core of engineering. Recognizing the importance of design thinking, we restructured our first-year design experience for mechanical engineering students at Saint Louis University. The course is structured around projects and uses the flip-classroom format. The first half of the course is focused on learning the traits of a designer/innovator, identifying unmet user needs, and developing innovative concepts. In these projects, students create a video to describe the traits of a designer, present an unmet need to a panel of judges, and create a poster to illustrate potential concepts. The paper presents an overview of the course along with the details of the projects.

In executing these projects, digital storytelling (DST) is a powerful tool that can enhance communication, create an emotional connection, and focus on experiences rather than products. Further, DST is a powerful skill in this digital age. To help students, we weaved DST into the course with three immersion modules — telling your story effectively, telling your story effectively with infographics, and making your story tangible.

The paper details the three digital storytelling modules to help others learn, integrate and implement digital storytelling with the courses that they teach. The first module helps students to storyboards, create impactful slide decks, and practice narration (using tools such as Present with Coach in Microsoft PowerPoint). The second module builds on the first module and brings in the elements of data presentation — which engineers often have to deal with and convey. The module helps in framing infographics and helps design presentations that effectively share qualitative and quantitative information. The module goes beyond the traditional charts and graphs and uses modern data visualization tools such as flourish.studio and d3.js. The third module empowers students to transform story elements into a physical or tangible form using props, analogies, and 3D printing techniques. These techniques help make the story accessible, memorable, and engaging for audiences, enhancing its impact. The three modules help them to develop skills in conveying the key message using storytelling.

Finally, the external project evaluators found a significant improvement over the three projects. Their assessment is also summarized in the paper. Thus, the paper will help faculty teaching similar engineering courses to integrate DST and enhance the skills of their students.
The Impact of Different Backbone Architecture on Autonomous Vehicle Dataset
Authors: Ding Ning , Eskandarian Azim
Published: February 2024

Object detection is a crucial component of autonomous driving, and many detection applications have been developed to address this task. These applications often rely on backbone architectures, which extract representation features from inputs to perform the object detection task. The quality of the features extracted by the backbone architecture can have a significant impact on the overall detection performance. Many researchers have focused on developing new and improved backbone architectures to enhance the efficiency and accuracy of object detection applications. While these backbone architectures have shown state-of-the-art performance on generic object detection datasets like MS-COCO and PASCAL-VOC, evaluating their performance under an autonomous driving environment has not been previously explored. To address this, our study evaluates three well-known autonomous vehicle datasets, namely KITTI, NuScenes, and BDD, to compare the performance of different backbone architectures on object detection tasks.
Research on Integrated Forming Process of Flange Nuts by Three-Roll Skew Rolling and Piercing
Authors: Siyuan Chen , Fei Lin , Xuedao Shu , Zixuan Li , Haijie Xu , Jinrong Zuo , Ying Wang , Yimin Deng
Published: February 2024

In order to realize the high-quality production of large-size flange nuts, a new integrated forming process of flange nut blank by three-roll skew rolling and piercing is proposed in this paper. Different from the traditional hot upsetting and forging process, this new process integrates perforation and flange forming, and the whole process goes through the perforation stage and the reducing stage. Based on Simufact.Forming 15.0, the finite element simulation model forming flange nuts by three-roll skew rolling and piercing was established, and the feasibility and forming law of flange nut blank manufactured by the new process were explored. Seven main process parameters (speed of the barrel roller, feed angle of the barrel roller, plug advance, speed of the disc roller, feed angle of the disc roller, radial feed speed of the disc roller, axial traction speed of the chuck) were selected and imported into the simulation model for single factor analysis. The influence of different process parameters on the force and energy parameters of the piercing section and the forming section was explored, and the feasibility of forming the flange nut blank by the three-roll skew rolling and piercing process was verified.
Ungrading in a Mechanics Curriculum: Identifying Gaps in Student Metacognition
Authors: Schmitz Anne
Published: February 2024

National data has shown a gap in metacognition or self-awareness where students tend to rate themselves higher in proficiency on career-ready skills than employers. The goal of this study is to identify metacognition gaps in the study habits of students in a subset of mechanics courses. Based on modern pedagogical research, two mechanics courses were structured as “ungraded” with a transparent “high-structure” for success where grades were based solely on standards-based grading of summative exams and lab practicals. Students were asked to rank the formative assessments (book reading assignments, quizzes, homework, and lab assignments) from most to least helpful to their learning. In week 7, the students in the sophomore mechanics course (strength of materials) rated labs as most helpful. However, grades were found to be most correlated with book reading notes. This shifted in week 14 where students found homework most helpful but labs were most correlated with grades. The students in a junior/senior mechanics course (machine component design) also rated labs most helpful initially in week 7. However, grades were found to be most correlated with homework. This also shifted in week 14 where students viewed homework as most helpful. This aligned with the grade book data that showed homework to be most correlated with grades. These results show that the sophomore students in this study exhibited larger gaps in metacognition of effective study habits than the junior/senior engineering students. This indicates that engineering students may not develop effective study habits until their senior/junior year of college. This supports the course design strategy of “high-structure” that is recommended in the literature.
eVTOL UAV Conversion to Hydrogen Fuel-Cell Power Source for Enhanced Endurance
Authors: Almesafri Nouf , Alhammadi Majed , Zafar Sayem , Dos Santos Gustavo
Published: February 2024

A study is conducted to investigate the integration of a hydrogen fuel cell power system to a small electric vertical take off and landing (eVTOL) Unmanned Aerial Vehicle (UAV) at Technology Innovation Institute (TII), Abu Dhabi. A hybrid power system is used comprising of hydrogen fuel cell for forward flight and lithium polymer batteries of vertical flight during take-off and landing phase. The hybrid power system is proposed as a substitute to the existing batteries in order to enhance the endurance of eVTOL UAVs. The eVTOL UAV used in this study is Dronepoulis ESA-90 which has four vertical flight motors and a single forward flight motor. Data simulations are conducted for the cruise power of 750 W which is consumed by the forward flight motor. The results show that the flight endurance of the UAV increased from 90 min to 272 minutes when hydrogen fuel cell power system is used. Further studies show that increasing the hydrogen pressure in the cylinder and increasing the size of the cylinder increased the flight endurance of the UAV. Increasing the size of the cylinder can potentially increase the flight endurance of the UAV as long as the overall weight remains within the maximum take-off weight limit.
Enhanced Performance of Laser Dressed Wheels in Internal Grinding of Bearing Steel Parts
Authors: Bindgi Sudheendra , N. Ramesh Babu
Published: February 2024

Internal griding is used for manufacturing of bearing inner races. As the process involves larger area of contact between the wheel and work material, the wear of abrasives as well as the chip entrapment in the pores of the wheel cause the deterioration of wheel performance in internal grinding of parts. This will, in turn, result in huge rejection of parts. Thus, the wheel is periodically dressed using a single point diamond dresser to remove the worn abrasives and grinding debris entrapped in pores of the wheel. Though this method is widely employed in industry, it causes excessive loss of wheel material and also generated inconsistent topography on the wheel surface due to continuous wear of the dresser. This paper covers the development of on-line laser dressing system made on a production grinder and different studies to evaluate the technical feasibility of on-line laser dressing of wheels. The performance of laser dressed wheels was evaluated by different aspects such as specific grinding energy, wheel wear, grinding ratio, roundness and the finish on the ground parts. By comparing the performance of laser dressed wheel with that of the diamond dressed wheel, the technical merits of online dressing of grinding wheels was demonstrated.
Optimized Thermal Performance of CPU Coolers Using Different Working Fluids
Authors: Das Shuva , Molki Majid
Published: February 2024

Over time there has been a notable increase in the use of computers in all fields. The processor technology is equally upgrading over time. Efficient processors demand efficient cooling. Thus, the CPU cooler research becomes significant. In this study, we have investigated a desktop computer CPU cooler. The heat transfer mechanism in such CPU coolers is conjugate heat transfer. With heat pipe temperature and Reynolds number ranging from 35° to 95°C and 100 to 2000, a Nusselt number correlation is obtained considering air as the working fluid. Then, the case is further examined for three working fluids, Helium, Hydrogen, and CO2, which have varying thermophysical properties. This analysis is then performed, maintaining two criteria. The first criterion maintains the same Reynolds number for all the working fluids. The second criterion maintains the same airflow range regardless of the individual Reynolds number. Helium shows four times better heat transfer than air for a fixed Re. The other case also shows Helium as the leading heat rate solution. Overall, this study discusses the potential of using various working fluids in designing thermally efficient CPU coolers.
Modelling of a Drone to Analyze Dynamic Instabilities With its Delivery System
Authors: Marquez Eleazar , Luna Ivan
Published: February 2024

In the study herein, an alternative mathematical model was developed with the intention of understanding the dynamics associated with the instabilities generated by an UAV and its delivery system, particularly the coupled nonlinearities of the system, and thus provide feedback to optimize drone design. In this regard, a Newton-Euler methodology was adopted to establish the parameters of the equations of motion of the target UAV system, which consisted of a combination of a platform and delivery system operating simultaneously. Specifically, the UAV platform was modelled as a rigid body which accounted for a total of six-degrees-of-freedom, three corresponding to the linear (position) directions of the system, and three correlative with the rotational (attitude) directions, thus elucidating drone maneuverability during operation. In this context, the delivery system, attached to the center of the UAV platform, was simultaneously modelled to account for oscillation patterns relative to a single coordinate of the platform, as well as the payload of the package unit. The response of the UAV and its delivery system was captured by imposing various initial conditions, while a power spectral density function was approximated to elucidate the dynamic characteristics of the drone.
Fastenerless Joining of Carbon Fiber Reinforced Thermoplastic Composite to Aluminum
Authors: Phadatare Akash , Jo Eonyeon , Pokkalla Deepak Kumar , Kim Seokpum , Vaidya Uday
Published: February 2024

Continuous efforts are underway for the reduction of the structural weight of transit through the introduction of a multi-material metal-composites system. There are major challenges in joining dissimilar materials to result in optimum structural integrity. The conventional joining techniques have limitations in terms of preparation time, weight penalty resulting from adhesives, and uncertainty in joint integrity. Recently adoption of macro scale mechanical interlocking in the adhesive joining resulted in significant improvement of joint performance. This made mechanical interlocking gain an attention for hybrid joining. In this study, fastenerless method of mechanical interlocking based on Japanese wood joining craft is considered for joining carbon fiber-reinforced polyamide thermoplastic composite to aluminum. Different interlocking joining designs (IJDs) were developed. The joints were obtained by force-fitting the male into the female counterpart. Here the male and female segments joined at macro level with no joining integrity at the interface. Further, these joints were tested and evaluated for tensile strength. A finite element analysis (FEA) model is developed for stress analysis and studying failure mechanisms of the IJDs. It was observed that the geometry of IJD dictates the failure mode and material composition governs the maximum strength achieved by a particular IJD. Each IJD showed higher load capacity with metal as a female counterpart to the composite compared to other way round.
In-Situ Calibration for Load Cells in 3d Printed Bipedal Robot Using 3D Modeling in Computer-Aided Design Environment
Authors: Le Xuan Tung , Herron Connor W. , Leonessa Alexander
Published: February 2024

This paper presents an in-situ calibration for load cells in a bipedal robot. Here the problem is tackled by using mechanical simulation using the 3D Computer-Aid Design (CAD) modeling of the robot. Since mechanical simulation is very high computational power demanding and it needs to be very precise for the calibration, new simplification methods are used for the robot CAD modeling to make the simulation able to run on ordinary personal computers. The results show that the new in-situ calibration method is easy to work with, the force values still meet the requirement for calibration and the computer only needed 10–12 seconds to run for each simulation.
A Three-Electrode Three-Dimensional Impedance-Based Biochemical Sensor for Food Safety Applications
Authors: Zamiri Athena , Shavezipur Mohammad
Published: February 2024

This work presents an innovative structure for impedance-based MEMS biochemical sensors with three electrodes that are stacked on top of one another, creating a 3D geometry with a parallel-plate configuration. The sensor is designed to mimic the porous surface of fresh produce for food safety applications. To characterize the sensor’s electrochemical behavior, we use a chemical, di-ethylhexyl phthalate (DEHP). The sensor is fabricated using PolyMUMPs and is exposed to different concentrations of DEHP, ranging from 0.02 ppm to 20 ppm. Three electrodes used in the sensor create two pairs of sensing electrodes (top-middle electrodes and middle-bottom electrodes) and their impedance spectroscopy response is recorded. The EIS test results show that similar to conventional interdigitated sensors, each pair of electrodes can detect the change in concentration of DEHP, and their Nyquist responses display diffusion effect, charge transport and double-layer effect. Furthermore, due to the parallel-plate geometry of the electrodes, the electrostatic effect is noticeable resulting in a region at the higher end of the frequency spectrum where the electrostatic capacitance affects the Nyquist response. This characteristic of the response is of great importance to detect the internalization of microorganisms when the device is used for pathogen detection.
Energy Sensors and Absorbers Based on Nanoscale Magnetic Tunnel Junction Metamaterials
Authors: Mengesha Betelhiem N. , Estevez Hernandez Juan , Feutmba Arnold , Tyagi Pawan
Published: February 2024

This paper explores nanoscale energy sensors and absorber metamaterials that can be used in various applications, such as solar cells and infrared detectors. It is possible to gain highly efficient and adjustable energy absorption, creating absorber metamaterials at the nanoscale that enhance the performance of solar cells. These metamaterials are based on molecular spintronics devices (MSD) and magnetic tunnel junctions (MTJ). The pillar shaped MTJs are made of two ferromagnetic metals separated by an insulating barrier, such as aluminum oxide (AlOx). The manufacturing process includes photoresist spin coating on a silicon wafer, photolithography, thin film sputtering, and liftoff. Following fabrication, the top and bottom electrodes are covalently bonded by a single molecule magnet (SMM) on the exposed side edges for strong magnetic coupling that changes the magnetic properties of both ferromagnetic metals. This study has considered different thin film deposition materials, configurations, and thicknesses. Magnetic field resonance and light reflectance measurements have been performed before and after molecule attachment to understand the molecule effect on the metamaterials’ energy absorption behavior. The Electron Spin Resonance (ESR) test revealed that the devices shifted following molecule attachment in both acoustic and optical modes. Moreover, due to molecule attachment, there have been significant alterations in the MTJ’s electromagnetic wave absorption characteristics with about 49% less reflectance. This metamaterial has various potential applications in aerospace, renewable energy, sensing, imaging, and communication. It is also a cheaper alternative to traditional solar cells and can inspire the development of smart metamaterials with selective absorption and tunable response.
A Novel Solar Absorption Cogeneration System With an Adjustable Cooling-to-Power Ratio
Authors: Alghamdi Abdulmajeed M. , Sherif S. A.
Published: February 2024

In this work, a novel solar double-effect absorption combined cooling and power (DECCP) system with an adjustable cooling-to-power ratio is proposed. This cogeneration system uses water-LiBr as the working fluid. The novel cycle upon which this system is based has been mathematically modeled, simulated, and parametrically analyzed to generate the system’s performance characteristics for several scenarios. The performance has been compared with those of other similar combined cogeneration cycles. It was found that the proposed cycle outperforms the other cycles from the vantage point of the power produced and the cycle’s ability to produce cooling. For specific operating parameters, the DECCP cycle achieves an exergetic efficiency that varies between 36.55–59.13% based on the refrigerant split ratio used. An effective operating strategy is proposed for the cycle when it is powered by solar energy.
Numerical Analysis of Air Curtain Jet Blast Deflector
Authors: Fletcher Stuart , Walters D. Keith , Leylek James H.
Published: February 2024

This paper presents the numerical results for a novel proof of-concept jet blast deflector design based on use of a high-speed air curtain to deflect aircraft engine exhaust gases during aircraft carrier launch operations. The resulting flowfield represents a supersonic turbulent jet-to-jet interaction that is highly dependent on the location, geometry, and flow conditions of the engine exhaust gases and the air curtain outlet. The complex fluid dynamics was numerically analyzed with the open source computational fluid dynamics (CFD) solver flowPsi, using a k-ω SST turbulence model. The domain was modeled based on the launch of a dual-engine fighter jet and includes an air curtain set at varying angles to the carrier flight deck. Simulations were run to investigate the feasibility of substituting actively cooled aircraft carrier jet blast deflectors with a high velocity air curtain, capable of dissipating aircraft jet exhaust during the catapult launch, with the intention of reducing annual maintenance costs and expenditures. Simulations are performed for several different exhaust conditions representative of actual fighter jet operation, including with and without afterburner. Results obtained from the simulations show promising capabilities and are presented and discussed in detail.
Mechanical Properties of Stretchable Multifunctional Ecoflex Composites for E-Skin Applications
Authors: Guler Zeynel , Jackson Nathan
Published: February 2024

Stretchable silicone elastomers are widely used in various applications such as robotics and wearable technologies due to their mechanical tunability, widespread availability, low cost, and ease of manufacturing. However, elastomers typically have no functional properties, and are often just used for their unique mechanical properties. Recently composite materials using an elastomer backbone have been developed to add functionality such as electrical conductivity, piezoelectric, and magnetic properties. However, research on the effects of mechanical properties due to the addition of these nanoparticles is limited, especially at the micro scale. This study investigates the feasibility of fabricating highly stretchable Ecoflex 00-30 composites containing various nanoparticles and the mechanical properties of these composites. Various nanoparticles were investigated with varying concentrations, and we investigated macro and micro sized samples. Nanoparticles investigated include lead zirconate titanate, neodymium iron boron, Terfenol-D and mixtures of these with varying concentrations up to 80 wt%. The 80% NdFeB composite demonstrated a remanence value of 0.75 T. The piezoelectric properties of PZT/Ecoflex were 1.7 pC/N (d33), and the Terfenol-D composite demonstrated a Villari effect. Most particularly, mechanical behavior of the samples has been comprehensively analyzed based on the tensile tests of different sized specimens. With increasing particle concentration, a promising elevation in the elastic modulus along with a high ductility was obtained.
Material and mechanical properties of young basalt in drill cores from the oceanic island of Surtsey, Iceland
Authors: Jackson M.D. , Heap M.J. , Vola G. , Ardit M. , Rhodes J.M. , Peterson J.G. , Tamura N. , Gudmundsson M.T.
Published: February 2024

Characterization of 2017 drill core samples from Surtsey, an oceanic island produced by 1963–1967 eruptions in the offshore extension of Iceland's east rift zone, reveals highly heterogeneous microstructural, physical, and mechanical properties in subaerial, submarine, and subseafloor basaltic deposits. The connected porosity varies from 42% in weakly consolidated lapilli tuff in a submarine inflow zone to 21% in strongly lithified lapilli tuff in upper subseafloor deposits near the explosively excavated conduit. Permeability, however, varies over six orders of magnitude, from 10−18 m2 to 10−13 m2. Uniaxial compressive strength, P-wave velocity, and thermal conductivity are also highly variable: 10–70 MPa, 1.48–3.74 km·s−1, and 0.472–0.862 W·m−1·K−1, respectively. Synchrotron X-ray microdiffraction analyses integrated with major-element geochemistry and quantitative X-ray powder diffraction analyses describe the initial alteration of fresh glass, incipient consolidation of a fine-ash matrix, and partial closure of pores with mineral cements. Permeability, micromechanical, and thermal property modeling highlight how porosity and pore size in eruptive fabrics—modified through diverse cementing microstructures—influence the physical properties of the pyroclastic deposits. Borehole temperatures, 25–141 °C (measured from 1980 to 2018), do not directly correlate with rock strength properties; rather, the abundance and consolidation of a binding fine-ash matrix appears to be a primary factor. Analytical results integrated with archival data from 1979 drill core samples provide reference parameters for geophysical and heat transfer studies, the physical characteristics of pyroclastic deposits that lithify on a decadal scale, and the stability and survival of oceanic islands over time.
Comparison of two different oxygen saturation target ranges for automated oxygen control in preterm infants: a randomised cross-over trial
Authors: Brouwer Fleur , Salverda Hylke H , Cramer Sophie J E , Schmeits Chantal , van der Plas Jacoline , te Pas Arjan B , Dekker Janneke
Published: February 2024

Objective

To compare the effect of peripheral oxygen saturation (SpO2) target range (TR) (either 91%–95% and 92%–96%) on the frequency and duration of hypoxic and hyperoxic episodes while on automated oxygen control using the OxyGenie controller.

Design

Randomised cross-over study.

Setting

Tertiary-level neonatal unit in the Netherlands.

Patients

Infants (n=27) with a median (IQR) gestational age of 27+0 (25+5–27+3) weeks and postnatal age of 16 (10–22) days, receiving invasive or non-invasive respiratory support.

Interventions

In both groups supplemental oxygen was titrated to a TR of 91%–95% (TRlow) or 92%–96% (TRhigh) by the OxyGenie controller (SLE6000 ventilator) for 24 hours each, in random sequence. After a switch in TR, a 1-hour washout period was applied to prevent carry-over bias.

Main outcome measures

Frequency and duration of hypoxic (SpO2<80% for ≥1 s) and hyperoxic episodes (SpO2>98% for ≥1 s).

Results

Hypoxic episodes were less frequent when the higher range was targeted (TRhighvs TRlow: 2.5 (0.7–6.2)/hour vs 2.4 (0.9–10.2)/hour, p=0.02), but hyperoxic episodes were more frequent (5.3 (1.8–12.3)/hour vs 2.9 (1.0–7.1)/hour, p<0.001). The duration of the out-of-range episodes was not significantly different (hypoxia: 4.7 (2.8–7.1) s vs 4.4 (3.7–6.5) s, p=0.67; hyperoxia: 4.3 (3.3–4.9) s vs 3.9 (2.8–5.5) s, p=0.89).

Conclusion

Targeting a higher SpO2TR with the OxyGenie controller reduced hypoxic episodes but increased hyperoxic episodes. This study highlights the feasibility of using an automated oxygen titration device to explore the effects of subtle TR adjustments on clinical outcomes in neonatal care.

Trial registration number

NL9662.
Variation in occupational exposure risk for COVID-19 workers’ compensation claims across pandemic waves in Ontario
Authors: Smith Peter M , Liao Qing , Shahidi Faraz , Biswas Aviroop , Robson Lynda S , Landsman Victoria , Mustard Cameron
Published: February 2024

Objectives

To understand rates of work-related COVID-19 (WR-C19) infection by occupational exposures across waves of the COVID-19 pandemic in Ontario, Canada.

Methods

We combined workers’ compensation claims for COVID-19 with data from Statistics Canada’s Labour Force Survey, to estimate rates of WR-C19 among workers spending the majority of their working time at the workplace between 1 April 2020 and 30 April 2022. Occupational exposures, imputed using a job exposure matrix, were whether the occupation was public facing, proximity to others at work, location of work and a summary measure of low, medium and high occupational exposure. Negative binomial regression models examined the relationship between occupational exposures and risk of WR-C19, adjusting for covariates.

Results

Trends in rates of WR-C19 differed from overall COVID-19 cases among the working-aged population. All occupational exposures were associated with increased risk of WR-C19, with risk ratios for medium and high summary exposures being 1.30 (95% CI 1.09 to 1.55) and 2.46 (95% CI 2.10 to 2.88), respectively, in fully adjusted models. The magnitude of associations between occupational exposures and risk of WR-C19 differed across waves of the pandemic, being weakest for most exposures in period March 2021 to June 2021, and highest at the start of the pandemic and during the Omicron wave (December 2021 to April 2022).

Conclusions

Occupational exposures were consistently associated with increased risk of WR-C19, although the magnitude of this relationship differed across pandemic waves in Ontario. Preparation for future pandemics should consider more accurate reporting of WR-C19 infections and the potential dynamic nature of occupational exposures.
The Physician Surprise Question in the Emergency Department: prospective cohort study
Authors: Ribeiro Sabrina Correa Costa , Arantes Lopes Thiago Augusto , Costa Jose Victor Gomes , Rodrigues Caio Godoy , Maia Ian Ward Abdalla , Soler Lucas de Moraes , Marchini Julio Flavio Meirelles , Neto Rodrigo Antônio Brandão , Souza Heraldo Possolo , Alencar Júlio César Garcia
Published: February 2024

Objectives

This study aims to test the ability of the surprise question (SQ), when asked to emergency physicians (EPs), to predict in-hospital mortality among adults admitted to an emergency room (ER).

Methods

This prospective cohort study at an academic medical centre included consecutive patients 18 years or older who received care in the ER and were subsequently admitted to the hospital from 20 April 2018 to 20 October 2018. EPs were required to answer the SQ for all patients who were being admitted to hospital. The primary outcome was in-hospital mortality.

Results

The cohort included 725 adults (mean (SD) age, 60 (17) years, 51% men) from 58 128 emergency department (ED) visits. The mortality rates were 20.6% for 30-day all-cause in-hospital mortality and 23.6% for in-hospital mortality. The diagnostic test characteristics of the SQ have a sensitivity of 53.7% and specificity of 87.1%, and a relative risk of 4.02 (95% CI 3.15 to 5.13), p<0.01). The positive and negative predictive values were 57% and 86%, respectively; the positive likelihood ratio was 4.1 and negative likelihood ratio was 0.53; and the accuracy was 79.2%.

Conclusions

We found that asking the SQ to EPs may be a useful tool to identify patients in the ED with a high risk of in-hospital mortality.
Relationship between chain axial resistance and confining stress for South China Sea carbonate sand: an element test
Authors: Guo Zhen , Zhou Zefeng , Jostad Hans Petter , Wang Lizhong , Rui Shengjie
Published: February 2024

For mooring systems, the relationship between chain axial resistance and confining stress affects the tension transfer of embedded mooring chain, and an effective width parameter Et was adopted to reflect the complex geometry of the chain. However, the relationship in carbonate sand is fully understood. Designed as an element test, monotonic and cyclic loading tests were conducted to investigate the variation of chain axial resistance with confining stress under different conditions in South China Sea carbonate sand. Peak effective width parameter and secant coefficient were particularly analyzed to describe the gradual mobilization. The results show that the Et value in South China Sea carbonate sand has a mean increase of 15% compared with Pingtan quartz sand, which makes the chain harder to pull into the carbonate sand. The irregular particle shape may contribute to the higher axial resistance. In cyclic tests, the peak post-cyclic Et-m is larger than that of monotonic test under lower confining stress but is smaller under higher stress. This paper provides some references to chain profile prediction in the carbonate sand.
Environmental radon control in the 700 m underground laboratory at JUNO
Authors: Cui Chenyang , Zhao Jie , Li Gaosong , Zhang Yongpeng , Guo Cong , Qu Zhenning , Wang Yifang , Li Xiaonan , Wen Liangjian , He Miao , Sisti Monica
Published: February 2024

The Jiangmen Underground Neutrino Observatory is constructing the world’s largest liquid scintillator detector, with a 20 kt target mass and approximately 700 m of overburden. The total underground space of civil construction is around 300,000 m$$^3$$

3

, with the main hall comprising about 120,000 m$$^3$$

3

, making it the largest experimental hall in the world. Maintaining a low radon concentration in the underground air is crucial for both human health and the accuracy of experiments involving rare decay detection, such as neutrino and dark matter experiments. To ensure human health and the integrity of neutrino physics experiments, the nominal radon concentration in the main hall must be kept below 200 Bq/m$$^3$$

3

with a maximum value below 400 Bq/m$$^3$$

3

. Introduction of fresh air from above ground can significantly lower radon concentration. A benchmark experiment conducted in the refuge room near the main hall revealed that the radon emanating from underground water is a significant source of radon in the underground air. The total underground ventilation rate is approximately 160,000 m$$^3$$

3

/h of fresh air with about 30 Bq/m$$^3$$

3

$$^{222}$$

222

Rn from the bottom of the vertical tunnel after the installation of powerful fans. Of this, 55,000 m$$^3$$

3

/h is used for ventilation in the main hall. As a result of these measures, the radon concentration inside the main hall has decreased from 1600 Bq/m$$^3$$

3

to below 200 Bq/m$$^3$$

3

under stable working conditions, with exceptions during rare adverse weather events or fan failures. The employed strategies to control radon concentration in the underground air are described in this paper.
Extended landslide velocity and analytical drag
Authors: Pudasaini Shiva P.
Published: February 2024

The landslide velocity plays a dominant role in estimating the impact force and devastated area. Here, based on Pudasaini and Krautblatter (Earth Surf Dyn 10:165–189, 2022. https://doi.org/10.5194/esurf-10-165-2022), I develop a novel extended landslide velocity model that includes the force induced by the hydraulic pressure gradient, which was neglected by all the existing analytical landslide velocity models. By a rigorous conversion between this force and inertia, which facilitates constructing exact analytical solutions for velocity, I develop two peer systems expecting to produce the same result. However, this contradicts with our conventional wisdom. This raises a legitimate question of whether we should develop some new balance equations such that these phenomena can be better explained naturally. I compare the two velocity models that neglect and include the force induced by the hydraulic pressure gradient. Analytical solutions produced by the two systems are fundamentally different. The new model is comprehensive, elegant, and yet an extraordinary development as it reveals serendipitous circumstance resulting in a pressure–inertia paradox. Surprisingly, the mass first moves upstream for quite a while; then, it winds back and continues accelerating down slope. The difference between the extended and simple solution is significant, and widens strongly as the force associated with the hydraulic pressure gradient increases, demonstrating the importance of this force in the landslide velocity. The viscous drag is an essential dissipative force mechanism and plays an important role in controlling the landslide dynamics. However, no explicit mechanical and analytical model exists to date for this. The careful sagacity of the graceful form of new velocity equation results in a plain, yet mechanically extensive, analytical model for viscous drag, the first of this kind. It contains several physical and geometrical parameters, and evolves dynamically as it varies inversely with the flow depth. A dimensionless drag number is constructed characterizing the drag dynamics. Importance of the drag model is explained. In contrast with the prevailing practices, I have proved that drags are essentially different for the expanding and contracting motions. This is an entirely novel revelation. Drag coefficients are close to the empirical or numerical values often used in practice. But, now, I offer an innovative, physically founded analytical model for the drag that can be instantly applied in mass flow simulations.
Inclusive $$B\rightarrow X_c \ell {\bar{\nu }}_\ell$$ and $$B\rightarrow X_u \ell {\bar{\nu }}_\ell$$ decays: current status and future prospects
Authors: Fael Matteo , Prim Markus , Vos K. Keri
Published: February 2024

The inclusive semileptonic $$B\rightarrow X_c \ell {\bar{\nu }}_\ell$$

B
→

X
c

ℓ

ν

¯

ℓ

and $$B\rightarrow X_u \ell {\bar{\nu }}_\ell$$

B
→

X
u

ℓ

ν

¯

ℓ

decays allow for the extraction of the CKM elements $$|V_{cb}|$$

|

V

cb

|

and $$|V_{ub}|$$

|

V

ub

|

, respectively. These extractions are based on the Heavy-Quark Expansion, where recent progress on both the experimental and theoretical side allow for impressively precise results. We review the recent developments in the study of inclusive decays and give an outlook for the future.
Multi-Modal Information Fusion for Localization of Emergency Vehicles
Authors: Joshi Aruna Kumar , Kulkarni Shrinivasrao B.
Published: February 2024

In urban and city environments, road transportation contributes significantly to the generation of substantial traffic. However, this surge in vehicles leads to complex issues, including hindered emergency vehicle movement due to high density and congestion. Scarcity of human personnel amplifies these challenges. As traffic conditions worsen, the need for automated solutions to manage emergency situations becomes more evident. Intelligent traffic monitoring can identify and prioritize emergency vehicles, potentially saving lives. However, categorizing emergency vehicles through visual analysis faces difficulties such as clutter, occlusions, and traffic variations. Visual-based techniques for vehicle detection rely on clear rear views, but this is problematic in dense traffic. In contrast, audio-based methods are resilient to the Doppler Effect from moving vehicles, but handling diverse background noises remains unexplored. Using acoustics for emergency vehicle localization presents challenges related to sensor range and real-world noise. Addressing these issues, this study introduces a novel solution: combining visual and audio data for enhanced detection and localization of emergency vehicles in road networks. Leveraging this multi-modal approach aims to bolster accuracy and robustness in emergency vehicle management.

The proposed methodology consists of several key steps. The presence of an emergency vehicle is initially detected through the preprocessing of visual images, involving the removal of clutter and occlusions via an adaptive background model. Subsequently, a cell-wise classification strategy utilizing a customized Visual Geometry Group Network (VGGNet) deep learning model is employed to determine the presence of emergency vehicles within individual cells. To further reinforce the accuracy of emergency vehicle presence detection, the outcomes from the audio data analysis are integrated. This involves the extraction of spectral features from audio streams, followed by classification utilizing a support vector machine (SVM) model. The fusion of information derived from both visual and audio sources is utilized in the construction of a more comprehensive and refined traffic state map. This augmented map facilitates the effective management of emergency vehicle transit. In empirical evaluations, the proposed solution demonstrates its capability to mitigate challenges like visual clutter, occlusions, and variations in traffic density common issues encountered in traditional visual analysis methods. Notably, the proposed approach achieves an impressive accuracy rate of approximately 98.15% in the localization of emergency vehicles.