Search Results (321)

A number of phenomena were observed in experiments on the study of cosmic rays at mountain altitudes and in the stratosphere at ultra-high energies; in particular, the coplanarity of the most energetic particles and local subcascades in the so-called families of γ-rays and hadrons in the cores of extensive air showers at E₀ ≳ 2·10¹⁵ eV (√s ≳ 2 TeV). These effects are not described by theoretical models. To explain this phenomenon, it may be necessary to introduce a new process of generating the most energetic particles in the interactions of hadrons with the nuclei of atmospheric atoms. A new experimental array of cosmic ray detectors, including the ADRON-55 ionization calorimeter, has been created to study processes in EAS cores at ultra-high energies. The possibility of using it to study the coplanarity effect is being considered. Full article

For further investigation of the properties of the muon component in the core regions of extensive air showers (EASs), a new underground hodoscopic set-up with a total sensitive area of 22 m² was built at the Tien Shan High Mountain Cosmic Ray Station. The hodoscope is based on a set of large-sized scintillation charged particle detectors with an output signal of analog type. The installation ensures a (5–8) GeV energy threshold of muon registration and a ∼${10}^4$ dynamic range for the measurement of the density of muon flux. A program facility was designed that uses modern machine learning techniques for automated search for the typical scintillation pulse pattern in an oscillogram of a noisy analog signal at the output of the hodoscope detector. The program provides a ∼99% detection probability of useful signals, with a relative share of false positives below 1%, and has a sufficient operation speed for real-time analysis of incoming data. Complete verification of the hardware and software tools was performed under realistic operation conditions, and the results obtained demonstrate the correctness of the proposed method and its practical applicability to the investigation of the muon flux in EASs. In the course of the installation testing, a preliminary physical result was obtained concerning the rise of the multiplicity of muon particles around an EAS core in dependence on the primary EAS energy. Full article

Background and Objectives: Intimate hygiene is essential in every woman’s cleaning routine and is strongly associated with women’s health. Unfortunately, there is minimal data available on correct intimate hygiene. Materials and Methods: This systematic review was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Multiple electronic databases (PubMed, Embase, Web of Science) were searched. Results: We included 33 studies published between 2000 and 2022 that investigated washing habits, various products, underwear preferences, and pubic hair grooming habits among women. A total number of 21 (64%) articles discussed topics associated with washing habits, including douching, washing product usage, and the choice between bathing and showering. Out of 33 articles, 7 (21%) discuss underwear, clothing, and panty liner usage as a feminine, everyday intimate hygiene routine. A total number of 11 (33%) studies included pubic hair removal methods, reasons, and associated complications in their article. Conclusions: The majority of women have basic knowledge about correct intimate hygiene, including showering at least once a day and regularly changing their underwear. Douching remains one of the most popular intimate hygiene habits among women. Pubic hair shaving became the primary preferred grooming method. Full article

A numerical simulation experiment is conducted to study the first-ever waterspout observed in Victoria Harbour, Hong Kong, in 2024, namely, a mesoscale meteorological model with a spatial resolution of 200 m coupled with a computational fluid dynamics model with a spatial resolution of 4 m. It is found that the simulation could reproduce the observed wind field near the surface reasonably well, as well as the location of the waterspout and showers, as shown in the weather image. By conducting simulations with and without buildings, it is found that the inclusion of buildings is essential for the successful reproduction of the flow fields near the surface and up to several hundred metres high. This may suggest that urbanization plays a role in the occurrence of this waterspout. The resultant horizontal vorticity is then stretched by strong vertical motion at around 850 hPa, resulting in the waterspout, though no closed circulation could be simulated at the location of the waterspout. Moreover, the cyclonic feature for the flow field near the surface has a time lag of about 30 min compared with the actual waterspout occurrence. Nonetheless, the simulation is considered to be generally satisfactory and provides useful insight into the occurrence of the waterspout. Full article

This study presents the findings of an academic extension project focused on promoting oral health and diagnosing oral lesions in institutionalized elderly individuals. The project involved visits by students and faculty to two nursing homes in southern Brazil. Data collection included extraoral and intraoral clinical examinations and educational activities such as lectures and the distribution of printed materials on oral and denture hygiene. According to caregiving staff, oral hygiene, including denture cleaning, was generally performed once daily during morning showers. A total of 118 older adults (68 males and 50 females; mean age 76.1 ± 8.6 years) were examined. Forty-nine used dentures, of whom only 24 (49%) reported satisfaction with their prostheses. In total, 42 oral lesions were identified, mainly angular cheilitis (8), inflammatory fibrous hyperplasia (7), irritation fibroma (7), frictional hyperkeratosis (7), prosthetic stomatitis (5), actinic cheilitis (3), traumatic ulcers (3), and leukoplakia (2). Educational sessions also targeted caregivers, offering practical guidance for improving hygiene practices. The results underscore the need for better oral care and improved access to dental services for institutionalized elderly populations. Academic extension activities play a valuable role in health promotion and in training future professionals in elderly care. Full article

Domestic showers are critical points of human exposure to microbial biofilms, which may harbor opportunistic pathogens such as Legionella spp. and nontuberculous Mycobacterium. However, biofilm development in reverse osmosis (RO)-treated drinking water systems remains poorly understood. We tested whether shower plumbing material (flexible polymer hose versus showerhead with inline polyethersulfone filter) and seasonal water variations influence biofilm community assembly. In a controlled field study, commercial shower systems were deployed in households supplied with RO-treated tap water from the KAUST Seawater Desalination Plant; biofilm samples were collected from hoses and filters over 3–17 months. Flow cytometry and 16S rRNA gene amplicon sequencing characterized microbial abundance, diversity, and taxonomic composition. We found that alpha diversity, measured by observed OTUs, was uniformly low, reflecting ultra-low biomass in RO-treated tap water. Beta diversity analyses revealed clear clustering by material type, with hoses exhibiting greater richness and evenness than filters. Core taxa—Pelomonas, Blastomonas, and Porphyrobacter—dominated both biofilm types, suggesting adaptation to low-nutrient, chlorinated conditions. Overall, our results demonstrate that ultra-low-nutrient RO tap water still supports the formation of material-driven, low-diversity biofilms dominated by oligotrophic taxa, underscoring plumbing-material choice as a critical factor for safeguarding shower water quality. These findings advance our understanding of biofilm ecology in RO-treated systems, informing strategies to mitigate potential health risks in shower water. Full article

Lorentz invariance is such a basic principle in fundamental physics that it must be constantly tested and any proposal of its violation and breakdown of CPT symmetry that might characterize some approaches to quantum gravity should be treated with care. In this review, we examine, among other scenarios, such instances in supercritical (Liouville) string theory, particularly in some brane models for “quantum foam”. Using the phenomenological formalism introduced here, we analyze the observational hints of Lorentz violation in time-of-flight lags of cosmic photons and neutrinos which fit excellently stringy space–time foam scenarios. We further demonstrate how stringent constraints from other astrophysical data, including the recent first detections of multi-TeV events in $\gamma$-ray burst 221009A and PeV cosmic photons by the Large High Altitude Air Shower Observatory (LHAASO), are satisfied in this context. Such models thus provide a unified framework for all currently observed phenomenologies of space–time symmetry breaking at Planckian scales. Full article

Amid rapid urbanization and climate change, global urban water consumption, particularly household water use, has continuously increased in recent years. However, the impact of climate change on individual and household water use behavior remains insufficiently understood. In this study, we conducted tracking surveys in Beijing, China, to determine the correlation between climatic factors (e.g., temperature, precipitation, and wind) and household water use behaviors and consumption patterns. Furthermore, we proposed a genetic programming-based algorithm to identify and quantify key meteorological factors influencing household and personal water use. The results demonstrated that water use is mainly affected by temperature, particularly the daily maximum (TASMAX) and minimum (TASMIN) near-surface air temperature. In addition, showering and personal cleaning account for the largest proportion of water use and are most affected by meteorological factors. For every 10 °C increase in TASMAX, showering water use nonlinearly increases by 3.46 L/d/person and total water use nonmonotonically increases by 1.14 L/d/person. When TASMIN varies between −10 °C and 0 °C, a significant change in personal cleaning water use is observed. We further employed shared socioeconomic pathway scenarios of the Coupled Model Intercomparison Project 6 to forecast household water use. The results showed that residential water use in Beijing will increase by 21–33% by 2035 compared with 2020. This study offers a groundbreaking perspective and transferable methodology for understanding the effects of climate change on household water use behavior, providing empirical foundations for developing sustainable water resource management strategies. Full article

Monte Carlo simulations of induced extensive air showers (EASs) by ultra-high-energy cosmic rays are widely used in comparison with measured events at experiments to estimate the main cosmic ray characteristics, such as mass, energy, and arrival direction. However, these simulations are computationally expensive, with running time scaling proportionally with the number of radio antennas included. The AugerPrime upgrade of the Pierre Auger Observatory will feature an array of 1660 radio antennas. As a result, simulating a single EAS using the full detector array will take weeks on a single CPU thread. To reduce the simulation time, detectors are commonly pre-selected based on their proximity to the shower core, using a selection ellipse based on the Cherenkov radiation footprint scaled by a fixed constant factor. While effective, this approach often includes many noisy antennas at high zenith angles, reducing computational efficiency. In this paper, we introduce an optimal method for selecting candidate detectors with high predicted signal-to-noise ratio for proton and iron primary cosmic rays, replacing the constant scaling factor with a function of the zenith angle. This approach significantly reduces simulation time—by more than 50% per CPU thread for the heaviest, most inclined showers—without compromising signal quality. Full article

Reliable cosmic-ray measurements require a thorough understanding of the detector used. It is especially important when detectors are very simple like the scintillator detectors considered in this work, which provide only information about the amplitude of the signal generated by a detected particle. Arrays of these devices can work in coincidental setups to detect Extensive Air Showers caused by high-energy primary cosmic rays. Due to their low cost and simple design, they can be used as elements of large detector networks needed for the search for global correlations in the cosmic rays. To be able to interpret data collected by those arrays, extensive simulations of such detectors are necessary to determine their efficiency of detection of different types of particles. This work presents the results of analysis of such simulations performed using the Geant4 software (v1.1.2). The analysis results lead to the conclusion that detectors feature almost maximal (close to 100%) efficiency for the detection of cosmic-ray muons and electrons with momenta greater than 0.03 GeV/c. Their sensitivity to low-energy electrons and photons is lower but not negligible and has to be properly taken into account during the interpretation of collected data. Full article

The $\mathsf{\mu }$PPET [mu($\mathsf{\mu }$)on Probe with J-PET] project aims to investigate the “Muon Puzzle” seen in cosmic ray air showers. This puzzle arises from the observation of a significantly larger number of muons on Earth’s surface than that predicted by the current theoretical models. The investigated hypothesis is based on recently observed asymmetries in the parameters for the strong interaction cross-section and trajectory of an outgoing particle due to projectile–target polarization. The measurements require detailed information about muons at the ground level, including their track and charge distributions. To achieve this, the two PET scanners developed at the Jagiellonian University in Krakow (Poland), the J-PET detectors, will be employed, taking advantage of their well-known resolution and convenient location for detecting muons that reach long depths in the atmosphere. One station will be used as a muon tracker, while the second will reconstruct the core of the air shower. In parallel, the existing hadronic interaction models will be modified and fine-tuned based on the experimental results. In this work, we present the conceptualization and preliminary designs of $\mathsf{\mu }$PPET. Full article

In this work we consider the problem of determining the identity of hadrons at high energies based on the topology of their energy depositions in dense matter, along with the time of the interactions. Using GEANT4 simulations of a homogeneous lead tungstate calorimeter with high transverse and longitudinal segmentation, we investigated the discrimination of protons, positive pions, and positive kaons at 100 GeV. The analysis focuses on the impact of calorimeter granularity by progressively merging detector cells and extracting features like energy deposition patterns and timing information. Two machine learning approaches, XGBoost and fully connected deep neural networks, were employed to assess the classification performance across particle pairs. The results indicate that fine segmentation improves particle discrimination, with higher granularity yielding more detailed characterization of energy showers. Additionally, the results highlight the importance of shower radius, energy fractions, and timing variables in distinguishing particle types. The XGBoost model demonstrated computational efficiency and interpretability advantages over deep learning for tabular data structures, while achieving similar classification performance. This motivates further work required to combine high- and low-level feature analysis, e.g., using convolutional and graph-based neural networks, and extending the study to a broader range of particle energies and types. Full article

Free-living protozoa (FLP) can create biofilms in water supply systems and can harbor bacteria, which potentially can be pathogenic, such as Legionella spp. Each year there are more cases of legionellosis in Latvia, so this problem is actual: in 2019 there were 42 cases, but in 2024—88 cases. In this study, the investigated question of the coexistence of FLP and Legionella spp. and bacterial diversity in the drinking water supply systems of Riga, Salaspils, and Jurmala multiapartment buildings and hotels situated in Riga and Jurmala, identify the main FLP genus, and study factors associated with FLP and Legionella spp. occurrence. With microscopy, microbiological, and molecular biology methods, FLP and, specifically, free-living amoeba (FLA) were detected and identified, and Legionella spp. bacteria were isolated. Three FLP genera were identified, including Acanthamoeba, Vahlkampfia, and Hartmanella (Vermamoeba). In hot water, more FLP and Legionella co-existence occurrences were detected. In 64.7% of FLP-positive samples, Hartmanella (Vermamoeba) spp. was detected. Various potentially pathogenic bacteria, such as Coxiella, Leptospira, and Mycobacterium, were detected in the water sample DNA sequences. The average hot water temperature in Riga was lower than 50 °C, which is not enough to minimize the risk of the Legionella bacteria proliferation. The Shannon’s index values showed that bacterial diversity was higher in cold water samples, and the Pearson test showed that the correlation between building floor and Legionella quantity is positive. In this study, we also discovered that differences in bacterial diversity between water samples from two Daugava River banks’ water sources are not significant, but the biggest exception was a much higher percentage of Chaetonotida (hairybellies) in the left river bank samples. Noticeably, there are more Legionella and FLP-positive samples from the kitchen than from the apartment shower. Each hotel building from this study has its own similar bacterial diversity in its water supply system. Full article

We simulate hadrons impinging on a homogeneous lead tungstate (${\mathrm{PbWO}}_4$) calorimeter using GEANT4 software to investigate how the resulting light yield and its temporal structure, as detected by an array of light-sensitive sensors, can be processed by a neuromorphic computing system. Our model encodes temporal photon distributions as spike trains and employs a fully connected spiking neural network to estimate the total deposited energy, as well as the position and spatial distribution of the light emissions within the sensitive material. The extracted primitives offer valuable topological information about the shower development in the material, achieved without requiring a segmentation of the active medium. A potential nanophotonic implementation using III-V semiconductor nanowires is discussed. It can be both fast and energy efficient. Full article

The thermodynamic, exergy and carbon reduction potential of seawater shower cooling towers for central air conditioning systems was investigated under various geometric, physical and environmental conditions. A mathematical model of the shower cooling tower was proposed, and the governing equations considering droplet diameter changes were numerically solved during evaporation. The results showed that compared with the downward-spraying tower, the upward-spraying tower achieved 15.59% higher cooling efficiency, 4.89% higher exergy efficiency and 34.58% higher heat dissipation. Increasing droplet diameter significantly weakened the tower’s cooling capacity, with heat dissipation decreasing by 78.11% as the diameter increased from 1 mm to 2.25 mm. The cooling efficiency, thermal efficiency and exergy efficiency demonstrated consistent declining trends with increasing droplet diameter. Under high-salinity conditions (105 g/kg), compared with standard salinity (35 g/kg), the average reduction of cooling efficiency was 2.96%, and exergy efficiency decreased by 2.73%. The increase in air velocity from 2.5 m/s to 4.0 m/s led to a 13.76% improvement in cooling efficiency and a 22.44% increase in heat dissipation, and exergy efficiency decreased by less than 2%. Through multi-objective optimization analysis, the cooling efficiency increased by 14.69% and exergy destruction decreased by 37.87%, demonstrating significant potential for energy conservation and carbon emission reduction in central air conditioning applications. Full article