The paper addresses the wear particles released from commercially available “low-metallic” automotive brake pads subjected to brake dynamometer tests. Particle size distribution was measured in situ ...and the generated particles were collected. The collected fractions and the original bulk material were analyzed using several chemical and microscopic techniques. The experiments demonstrated that airborne wear particles with sizes between 10
nm and 20
μm were released into the air. The numbers of nanoparticles (<100
nm) were by three orders of magnitude larger when compared to the microparticles. A significant release of nanoparticles was measured when the average temperature of the rotor reached 300
°C, the combustion initiation temperature of organics present in brakes. In contrast to particle size distribution data, the microscopic analysis revealed the presence of nanoparticles, mostly in the form of agglomerates, in all captured fractions. The majority of elements present in the bulk material were also detected in the ultra-fine fraction of the wear particles.
► Wear of low-metallic friction composite produces airborne nano-sized particles. ► Nano-sized particles contain carbon black and metallic compounds. ► Carbon black nano-sized particles are related to resin degradation. ► Number of nanoparticles higher by three orders of magnitude than microparticles.
Braking of automobiles may contribute to nano-particulate air pollution caused by friction processes associated with wear of low-metallic brake pads.
Current Monte Carlo simulations do not provide a good description of the muon component of extensive air showers. Many air shower experiments report discrepancies between their data and Monte Carlo ...predictions, ranging from the TeV scale up to the highest energies. In these proceedings, we address the seasonal variation of the multi-muon events observed by the NOvA Near Detector (ND). For our studies, we use the general-purpose Monte Carlo code FLUKA to treat the transport and interaction of the air-shower particles in the atmosphere and other media. Our design considers a multilayered atmosphere and a layered underground approximated to match the NOvA ND location and detector geometry. Our atmospheric model uses air densities for winter and summer calculated from the temperature and geopotential information for the pressure levels given by the European Center for Medium-Range Weather Forecasts (ECMWF) datasets in situ. Understanding the multi-muon flux at the cosmic ray high-energy range may lead to a better description of the muon production mechanisms in ultra-high-energy extensive air showers. In addition, it can help to improve future Monte Carlo codes or hint at new physics processes or interactions.
Finite element simulation is presented to study the rate effects of the shape memory response of bent NiTi wire “C-shaped” exposure to load. A three-dimensional constitutive model for shape memory ...alloys proposed by Auricchio is implemented in the built-in library of Ansys Workbench 18.2 to capture the shape memory behavior of three different NiTi alloys that are subjected to different thermomechanical treatments. The quasi-static (slow) loading rate and the dynamic (fast) loading rate have been applied isothermally or at adiabatic conditions. Other models assumed the classical shape memory stress-strain behavior, but the realistic behavior of the NiTi SMA is different. The NiTi SMA is influenced by its microstructural changes, such as internal defects, grain size, chemical compositions, content of dislocations and density; all these effects should be added when modeling, which has been considered in this study. The results showed a significant effect of the dynamic loading of NiTi on decreasing the recoverable strain. As a result, it could be expected that the actuator lifetime could be reduced when a rapid, as opposed to a slow, loading rate is adopted. Inhomogeneity of stresses and deformations after loading can cause irreversible plastic deformation. The complete deformation recovery is noticed in the reorientation scenario, unlike in the SIM scenario, which exhibits unrecoverable deformation. Experimental validation is done by comparing the macroscopic displacement of the bent NiTi actuator with the model results, which shows good agreement.
We suggest that modification of meson properties (lifetimes and branching ratios) can occur due to the interaction of constituent quark magnetic moments with strong magnetic fields present in the ...close vicinity of nuclei. A superposition of (J=0) and (J=1, m sub(z)=0) particle-antiparticle quantum states (as observed for ortho-Positronium) may occur also in the case of quarkonium states J/Psi, eta sub(c), Upsilon, eta sub(b) in heavy ion collisions. We speculate on possible modification of eta(548) meson properties (related to C parity and CP violation) in strong magnetic fields which are present in the vicinity of nuclei.
Due to the complexity of friction phenomena in polymer matrix composites, the friction mechanisms have not been fully understood. This paper concentrates on the characterization of friction layer ...formation and correlation of friction layer properties to the performance of a recently developed family of polymer matrix composites. It was demonstrated that character of the friction layer determines the friction performance of the investigated composite material. Structure and chemical composition of the friction layer generated on the friction surface significantly differs from the bulk. Mechano-chemical interaction occurring in the friction process is compared to a “non-friction” situation where an “equivalent” apparent temperature and compressive loading, respectively were applied to the same material. No simple relationship exists between composition of the friction layer and bulk material formulation. Phase stability and kinetics of interactions for “friction” and “equivalent non-friction” loading conditions significantly differ.
Objective
A key outcome measure in the clinical evaluation of dysphonia is the Voice Handicap Index (VHI‐10). The clinical validity of the VHI‐10 was established from surveys administered in the ...physician's office. We aim to understand whether VHI‐10 responses remain reliable when the questionnaire is completed in settings other than the physician's office.
Methods
This is a prospective observational study conducted over a 3‐month period in the outpatient laryngology setting. Thirty‐five adult patients presenting with a complaint of dysphonia, which was symptomatically stable for the preceding 3 months, were identified. Each patient completed a VHI‐10 survey during the initial office visit, followed by three weekly out‐of‐office (termed “ambulatory”) VHI‐10 surveys, over the course of 12 weeks. The specific setting in which the patient completed the survey was recorded (social, home, or work). The Minimal Clinically Important Difference (MCID) is defined as 6 points based on existing literature. T‐tests and a test of one proportion were used for analysis.
Results
A total of 553 responses were collected. Of these, 347 ambulatory scores (63%) differed from the Office score by at least the MCID. Specifically, 94 (27%) were higher than the in‐office score by 6 or more points while 253 (73%) were lower.
Conclusion
The setting in which the VHI‐10 is completed affects how the patient answers the questions. The score is dynamic, reflecting effects of the patients' environment during completion. Utilization of VHI‐10 scores to measure clinical treatment response is only valid if each response is obtained in the same setting.
Level of Evidence
4
Objective
Advances in deep learning and artificial intelligence (AI) have led to the emergence of large language models (LLM) like ChatGPT from OpenAI. The study aimed to evaluate the performance of ...ChatGPT 3.5 and GPT4 on Otolaryngology (Rhinology) Standardized Board Examination questions in comparison to Otolaryngology residents.
Methods
This study selected all 127 rhinology standardized questions from www.boardvitals.com, a commonly used study tool by otolaryngology residents preparing for board exams. Ninety‐three text‐based questions were administered to ChatGPT 3.5 and GPT4, and their answers were compared with the average results of the question bank (used primarily by otolaryngology residents). Thirty‐four image‐based questions were provided to GPT4 and underwent the same analysis. Based on the findings of an earlier study, a pass‐fail cutoff was set at the 10th percentile.
Results
On text‐based questions, ChatGPT 3.5 answered correctly 45.2% of the time (8th percentile) (P = .0001), while GPT4 achieved 86.0% (66th percentile) (P = .001). GPT4 answered image‐based questions correctly 64.7% of the time. Projections suggest that ChatGPT 3.5 might not pass the American Board of Otolaryngology Written Question Exam (ABOto WQE), whereas GPT4 stands a strong chance of passing.
Discussion
The older LLM, ChatGPT 3.5, is unlikely to pass the ABOto WQE. However, the advanced GPT4 model exhibits a much higher likelihood of success. This rapid progression in AI indicates its potential future role in otolaryngology education.
Implications for Practice
As AI technology rapidly advances, it may be that AI‐assisted medical education, diagnosis, and treatment planning become commonplace in the medical and surgical landscape.
Level of Evidence
Level 5.
Relevance of wear occurring in brakes increased with relation to the released chemicals and health and environmental hazards. Wear of brakes leads to formation of complex chemicals that are released ...into environment. Humidity can considerably modify the adhesion of surfaces by creating menisci and increasing the contact area. This paper addresses the impact of humidity on two commercial brake material types: "non-asbestos organic" and "semi-metallics" rubbed against pearlitic gray cast iron used in vehicles worldwide. The friction and wear tests were performed with the “UMT Lab Tester” manufactured by Bruker and the wear surfaces/mechanisms were studied by using of scanning electron microscopy, energy dispersive X-ray microanalysis, and optical topography methods. Both materials wore noticeably less at increased humidity. This was ascribed to a better capacity to form a protective friction layer. It was incorrectly assumed that humidity would be desorbed above the boiling point of water. The chemistry, morphology and phase composition of the friction layers formed on the surfaces during braking could play a determining role when amounts of adsorbed water are concerned. The wear mechanisms including abrasive, adhesive, fatigue, and corrosion wear were observed on both material types, irrespectively of humidity levels.
•Critical humidity level exists below which wear decreases and above which wear increases with increased humidity.•Friction layer consists of nanoparticles captured, compressed and sintered during friction.•Changes in the friction level of brakes, with increased humidity, depends on the character of water adsorbed regimes.•Specific character of the friction layer can protect surface against wear.
We suggest 3P0 quantum state of virtual (ss¯) pairs in the nucleon can be polarised by the internal fields permeating the volume of the nucleon (proton or neutron). Due to the quadratic Zeeman ...interaction, 3P0 wavefunction of virtual (qq¯) pairs acquires the admixture of 1P10 quantum state in the magnetic field, which generates the antiparallel polarization of s and s¯ quarks (in the nucleon). Considering the internal magnetic fields of neutron and proton (originating from their measured magnetic dipole moments), we suggest the induced s-quark polarization in the neutron to be of the oposite direction compared to the proton case. We mention the influence of the internal chromo-magnetic fields on the quantum state of (qq¯) pairs in the nucleon and we discuss also the expected behaviour of virtual (cc¯) pairs.
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