Threshold Frequency Research Articles

Optimization of surface water microfiltration with hydraulic and chemically enhanced backwashing

Short-term microfiltration (MF) fouling is commonly abated by periodically reversing the flow to remove foulants that weakly adhered to the membrane. Strong oxidants (i.e., chlorine) can be added to hydraulic backwash water to augment its efficacy—a process called chemically enhanced backwashing (CEB). Herein, we report a rigorous mathematical model for constant flux MF incorporating hydraulic backwashing and CEB, and validated with laboratory data obtained using untreated and alum-coagulated water from the Foss Reservoir in Oklahoma, USA. We implemented an optimal control procedure and used it to predict MF behavior long past experimental timescales. We identified a frequency threshold beyond which the necessary transmembrane pressure (TMP) reached an asymptotic value, indicating a pseudo steady-state, periodic solution to the model when coupling hydraulic backwashing with CEB. We report differences in TMP saturation values and timescales by simulating transient MF of untreated and pretreated water. Numerical simulations revealed that the operating flux could be increased 10-fold after pretreatment (compared with raw water) before reaching the maximum manufacturer-recommended pressure for the experimental hollow-fibers. The predicted higher flux and extended duration between cleaning-in-place demonstrated advantages of coagulation pretreatment under hydraulic backwashing and CEB. Model observations could guide decision making for CEB timing and frequency.

An adaptive load shedding methodology for renewable integrated power systems

System stability issues regarding frequency and voltage in modern power systems are growing in importance as they incorporate more and more complex components. To ensure a sustainable, pollution-free power generation, modern power systems are designed to incorporate more renewable generation sources than traditional ones. Therefore, in the event of a large-scale disruption event, conventional load-shedding strategies are unable to keep the voltage and frequency limit below the threshold value. The suggested approach takes into account this issue by rating load buses in relation to relevant frequency changes, their voltage stability, system load damping coefficients, and the introduction of green energy sources in place of fossil fuel-based ones. Battery Energy Storage Systems (BESS) are used in the proposed method to minimize load shedding amount required for conventional schemes. After determining the amount, the scheme dynamically chooses feeders as per relative weightage of the stability components (voltage, frequency) to ensure that the overall load shed amount is near to the calculated value. To verify this, the scheme is tested on IEEE 39 bus with python scripted simulation. There are four scenarios considering 250 MW, 500 MW and 1500 MW injection of PV based power generation sources with conventional generation loss of 800 MW and 1000 MW. The threshold frequency is considered 49.10 Hz. The total amount of BESS is 300 MW. For every scenario, it has been found that the methodology successfully maintains the system frequency above 49.10 Hz with a minimal amount of load shedding. Hence, the proposed methodology is able to maintain frequency stability for a modern power system with large-scale PV generation through adaptive feeder selection for load shedding.

A multitasking renal function assessment janus biosensor based on photonic spin Hall effect at epsilon-near-zero threshold frequency of YaBa2Cu3O7 ceramic material

Photonic spin Hall effect (PSHE) is an effective measurement approach for characterizing weak refractive index changes. In this paper, a multitasking renal function detection biosensor based on epsilon-near-zero threshold frequency of superconducting YaBa2Cu3O7 ceramic material is proposed, which provides a new way for the enhancement of PSHE. Using Brewster angle and critical angle at the interface of the epsilon-near-zero YaBa2Cu3O7 ceramic material, the maximum PSHE displacement for detection is enhanced to 54.681 times the wavelength λ. Through the asymmetric arrangement of different dielectrics, the biosensor is equipped with Janus property. When electromagnetic waves propagate on the forward and backward scales, glucose solution concentration, serum creatinine concentration, and cholesterol concentration can be accurately detected with a resolution up to 5 × 10−5 RIU and the highest sensitivity of 59.57 RIU−1. The designed biosensor breaks through the limitation of single scale and single function of conventional biosensors, and provides help for promoting comprehensive and accurate detection and treatment of kidney diseases.

Parental-effect gene-drive elements under partial selfing, or why do Caenorhabditis genomes have hyperdivergent regions?

Self-fertile Caenorhabditis nematodes carry a surprising number of Medea elements, alleles that act in heterozygous mothers and cause death or developmental delay in offspring that don't inherit them. At some loci, both alleles in a cross operate as independent Medeas, affecting all the homozygous progeny of a selfing heterozygote. The genomic coincidence of Medea elements and ancient, deeply coalescing haplotypes, which pepper the otherwise homogeneous genomes of these animals, raises questions about how these apparent gene-drive elements persist for long periods of time. Here I investigate how mating system affects the evolution of Medeas, and their paternal-effect counterparts, peels. Despite an intuition that antagonistic alleles should induce balancing selection by killing homozygotes, models show that, under partial selfing, antagonistic elements experience positive frequency dependence: the common allele drives the rare one extinct, even if the rare one is more penetrant. Analytical results for the threshold frequency required for one allele to invade a population show that a very weakly penetrant allele, one whose effects would escape laboratory detection, could nevertheless prevent a much more penetrant allele from invading under high rates of selfing. Ubiquitous weak antagonistic Medeas and peels could then act as localized barriers to gene flow between populations, generating genomic islands of deep coalescence. Analysis of gene expression data, however, suggest that this cannot be the whole story. A complementary explanation is that ordinary ecological balancing selection generates ancient haplotypes on which Medeas can evolve, while high homozygosity in these selfers minimizes the role of gene drive in their evolution.

Physical activity as a predictor of activities of daily living in older adults: a longitudinal study in China.

This study aimed to assess the prevalence of physical activity and its association with the progression of difficulty performing activities of daily living among older adults in China. A population-based prospective cohort study based on China Family Panel Studies (CFPS) data was conducted in 2018 and 2020. This study used a logistic model to empirically estimate the effects on daily living activities among older adults. A total of 2073 older adults aged 60 years and above were included, 78.0% of whom did not exercise. The logistic regression model revealed several predictive factors for activity of daily living decline among older adults. These included residence status (OR = 0.672; 95% CI 0.519-0.869; p = 0.002), age (OR = 0.307; 95% CI 0.169-0.557; p < 0.001), ethnicity (OR = 0.511; 95% CI 0.338-0.773; p = 0.001), education level (OR = 2.180; 95% CI 1.366-3.479; p < 0.001), job (OR = 0.601; 95% CI 0.447-0.810; p = 0.001), chronic disease (OR = 0.769; 95% CI 0.604-0.978; p = 0.032) and physical activity (less: OR = 0.464; 95% CI 0.300-0.720; p = 0.001; adequate: OR = 0.512; 95% CI 0.321-0.816; p = 0.005). Our findings indicate that insufficient physical activity is particularly acute among the older adults. Physical activity has emerged as a significant predictor of decreased daily living activities among older adults. Our research underscores that less and adequate physical activity can prevent a reduction in daily living activities, in contrast to a lack of exercise. The most effective threshold for daily exercise frequency is a session per day, while the ideal exercise duration is 15 min. Additionally, the desired intensity for exercise is characterized by rapid breathing and a noticeable heartbeat, accompanied by slight perspiration. Community nurses play a pivotal role in providing health education on daily exercise to the older adults. It is crucial for nurses in community hospitals to closely monitor the daily exercise habits of the older adults, actively disseminate the benefits of exercise, and enhance their current exercise regimens through effective health education, ultimately improving their quality of life.

Influence of Spatial Scale Effect on UAV Remote Sensing Accuracy in Identifying Chinese Cabbage (Brassica rapa subsp. Pekinensis) Plants

The exploration of the impact of different spatial scales on the low-altitude remote sensing identification of Chinese cabbage (Brassica rapa subsp. Pekinensis) plants offers important theoretical reference value in balancing the accuracy of plant identification with work efficiency. This study focuses on Chinese cabbage plants during the rosette stage; RGB images were obtained by drones at different flight heights (20 m, 30 m, 40 m, 50 m, 60 m, and 70 m). Spectral sampling analysis was conducted on different ground backgrounds to assess their separability. Based on the four commonly used vegetation indices for crop recognition, the Excess Green Index (ExG), Red Green Ratio Index (RGRI), Green Leaf Index (GLI), and Excess Green Minus Excess Red Index (ExG-ExR), the optimal index was selected for extraction. Image processing methods such as frequency domain filtering, threshold segmentation, and morphological filtering were used to reduce the impact of weed and mulch noise on recognition accuracy. The recognition results were vectorized and combined with field data for the statistical verification of accuracy. The research results show that (1) the ExG can effectively distinguish between soil, mulch, and Chinese cabbage plants; (2) images of different spatial resolutions differ in the optimal type of frequency domain filtering and convolution kernel size, and the threshold segmentation effect also varies; (3) as the spatial resolution of the imagery decreases, the optimal window size for morphological filtering also decreases, accordingly; and (4) at a flight height of 30 m to 50 m, the recognition effect is the best, achieving a balance between recognition accuracy and coverage efficiency. The method proposed in this paper is beneficial for agricultural growers and managers in carrying out precision planting management and planting structure optimization analysis and can aid in the timely adjustment of planting density or layout to improve land use efficiency and optimize resource utilization.

Research on a Multi-Scale Clustering Method for Buildings Taking into Account Visual Cognition

Building clustering is a key problem that needs to be solved in the realization of the automatic synthesis of large-scale maps. The selection of different feature and spatial distance calculation methods has a great impact on the clustering results, and the need to manually select appropriate feature and distance metrics leads to the problem of not being able to fully consider the complexity and diversity of buildings. In this paper, we propose a multi-scale clustering method for buildings that takes visual perception into account using the Gestalt principle to simulate how humans classify buildings through visual perception. Moreover, by analyzing the spatial features and texture attributes of buildings, a visual distance is designed to be used as a condition for building classification to assess the similarity between buildings, solving the complexity of manually selecting feature vectors and spatial distances and realizing the adaptive selection of features. Through experimental validation at different scales (macro, meso and micro), the present method is able to achieve the accurate clustering of buildings, and a frequency threshold of 91% is found, which is able to determine the optimal clustering results. The experimental results show that the proposed method can not only fully consider the complexity and diversity of buildings but also effectively support the understanding and analysis of urban spatial structure and provide a scientific decision-making basis for urban planning and management.

Effect of Age on Distortion Product Otoacoustic Emissions at Extended High Frequencies.

The inner ear is most susceptible to the aging effects. Distortion product otoacoustic emissions (DPOAEs) are a good indicator for interpreting the age effects but are usually recorded at up to 8000 Hz frequencies in routine audiologic testing. The present study was designed to assess and compare the DPOAEs at conventional frequencies and at extended high frequencies (EHFs) across different age groups. Extended high-frequency audiometry (9000-16000 Hz) and DPOAEs from 500-16000 Hz were recorded on 80 adult (160 ears) participants (15-55 years) with normal hearing sensitivity. The participants were categorized into 4 groups: group I (15-<25 years), group II (25-<35 years), group III (35-<45 years), and group IV (45-55 years). A statistically significant reduction in EHF thresholds was observed from group III onward. However, the thresholds were comparatively better for group III at frequencies 9000, 10000, and 11500Hz than group IV. No significant difference was observed for EHF DPOAEs in groups I and II (except at 16000 Hz) and III and IV. Distortion product otoacoustic emissions at conventional frequencies in group IV were significantly poorer than the other 3 groups. A weak negative correlation was observed between the DPOAE parameters and EHF thresholds. The effect of age was more pronounced on EHF DPOAEs than EHF thresholds for frequencies 9000, 10000, and 11500 Hz. Distortion product otoacoustic emissions at EHF started deteriorating below the age of 30 years and showed a rapid decline above 35 years. Extended high-frequency DPOAEs can be used as screening tools to assess the function of the basal part of the cochlea.

A Novel Ultrasonic Leak Detection System in Nuclear Power Plants Using Rigid Guide Tubes with FCOG and SNR.

Leak detection in nuclear reactor coolant systems is crucial for maintaining the safety and operational integrity of nuclear power plants. Traditional leak detection methods, such as acoustic emission sensors and spectroscopy, face challenges in sensitivity, response time, and accurate leak localization, particularly in complex piping systems. In this study, we propose a novel leak detection approach that incorporates a rigid guide tube into the insulation layer surrounding reactor coolant pipes and combines this with an advanced detection criterion based on Frequency Center of Gravity shifts and Signal-to-Noise Ratio analysis. This dual-method strategy significantly improves the sensitivity and accuracy of leak detection by providing a stable transmission path for ultrasonic signals and enabling robust signal analysis. The rigid guide tube-based system, along with the integrated criteria, addresses several limitations of existing technologies, including the detection of minor leaks and the complexity of installation and maintenance. By enhancing the early detection of leaks and enabling precise localization, this approach contributes to increased reactor safety, reduced downtime, and lower operational costs. Experimental evaluations demonstrate the system's effectiveness, focusing on its potential as a valuable addition to the current array of nuclear power plant maintenance technologies. Future research will focus on optimizing key parameters, such as the threshold frequency shift (Δf) and the number of randomly selected frequencies (N), using machine learning techniques to further enhance the system's accuracy and reliability in various reactor environments.

Influenza A virus within-host evolution and positive selection in a densely sampled household cohort over three seasons.

While influenza A virus (IAV) antigenic drift has been documented globally, in experimental animal infections, and in immunocompromised hosts, positive selection has generally not been detected in acute infections. This is likely due to challenges in distinguishing selected rare mutations from sequencing error, a reliance on cross-sectional sampling, and/or the lack of formal tests of selection for individual sites. Here, we sequenced IAV populations from 346 serial, daily nasal swabs from 143 individuals collected over three influenza seasons in a household cohort. Viruses were sequenced in duplicate, and intrahost single nucleotide variants (iSNVs) were identified at a 0.5% frequency threshold. Within-host populations exhibited low diversity, with >75% mutations present at <2% frequency. Children (0-5 years) had marginally higher within-host evolutionary rates than adolescents (6-18 years) and adults (>18 years, 4.4 × 10-6 vs. 9.42 × 10-7 and 3.45 × 10-6, P < .001). Forty-five iSNVs had evidence of parallel evolution but were not over-represented in HA and NA. Several increased from minority to consensus level, with strong linkage among iSNVs across segments. A Wright-Fisher approximate Bayesian computational model identified positive selection at 23/256 loci (9%) in A(H3N2) specimens and 19/176 loci (11%) in A(H1N1)pdm09 specimens, and these were infrequently found in circulation. Overall, we found that within-host IAV populations were subject to genetic drift and purifying selection, with only subtle differences across seasons, subtypes, and age strata. Positive selection was rare and inconsistently detected.

Deciphering the hydrodynamics of lipid-coated microbubble sonoluminescence for sonodynamic therapy

Sonodynamic therapy (SDT) is a minimally invasive targeted cancer therapy that uses focused low-intensity ultrasound (<10 MPa, <10 W/cm2) to activate sonosensitizer drugs. Once activated, these chemical compounds generate reactive oxygen species (ROS) to damage and kill cancer cells. A Phase I clinical trial has shown promising results for treating glioblastoma with SDT. We hypothesize that the efficacy of SDT can be improved by introducing lipid-coated microbubbles that produce a sonochemical effect that enhances ROS production. We investigate the hydrodynamics of a U.S. Food and Drug Administration (FDA)-approved microbubble, Lumason®, and a phospholipid-coated oxygen microbubble to predict the ultrasound parameters that induce sonoluminescence onset in biophysically relevant medium (e.g., water and blood) under clinical SDT conditions. The threshold pressures and frequencies for sonoluminescence with these therapeutic agents lie between 20 kHz – 1 MHz and 0.05 MPa – 1 MPa, respectively. The lipid-coated oxygen microbubble exhibits stronger sonoluminescence than the Lumason® microbubble, suggesting its use for improving SDT efficacy.

Modulating droplet electrohydrodynamics via the interplay of extensional flow and an alternating current electric field

Electric fields can be used to exert controlled time-varying forces on a droplet under progressive stretching in an extensional flow, allowing for its precise manipulation in various industrial and scientific applications, including microfluidics, materials science, and biological studies. However, the interaction between the combined extensional flow field and electric field may trigger a complex electrohydrodynamic response, as determined primarily by the capillary and viscous forces and the convection of surface charge. Here, we theoretically and computationally analyze the deformation and breakup of a droplet subjected to an alternating current (AC) electric field and uniaxial extensional flow. Our asymptotic theory, applicable in the small-deformation limit, quantifies the contributions of each applied field to the shape oscillations. Numerical simulations are employed to explore the dynamical evolution of the droplet in the nonlinear regime of variation in the capillary number. Our theoretical and numerical results are in excellent agreement, demonstrating that an AC electric field can significantly alter transient deformation depending on its magnitude and frequency. We identify the threshold frequency, dependent on the ratios of electrical properties, which can induce periodic oblate-prolate shape transitions. The interaction between viscous and electric stresses driving these transients is discussed. Contrary to intuition, strong electric fields greatly suppress shape oscillations, leading instead to large continuous elongations that eventually result in an end-pinching breakup mode, forming elongated bulbous-ended droplets. The breakup state, characterized by droplet length and shape at the onset of breakup, is determined by the field parameters and the physical properties of the fluids. Notably, the breakup state length and total breakup time have a non-monotonic relationship with the applied electric field frequency. The insights gained into the physics of oscillatory stable deformation and non-oscillatory unstable deformation offer new means of droplet manipulation in droplet-based micro-mechano-electrical systems that remained unexplored thus far.

A methodological exploration of the P-frame approach: Implications for developing phrase lists

The widespread availability of corpora and corpus tools has led to considerable advances in our understanding of phraseology and how it can be investigated. An increasingly influential approach to investigating phraseology is the retrieval and analysis of phrase frames (p-frames), recurrent word sequences with a variable slot. Although the p-frame approach is quite well-established, pedagogically oriented research in this area is still quite new, in particular the application of phrase frames to generate useful lists of phrases. This paper aims to contribute to methodological efforts in this direction by presenting a case study to illustrate decision-making throughout the process from corpus compilation to the generation of a final pedagogical list of phrases. Using a corpus of research article (RA) introductions in Health Sciences, this study shows how key decisions including p-frame length, frequency and range thresholds were arrived at. It also discusses exclusion criteria focusing on variability and predictability of p-frame fillers, and the fine-tuning of the resulting list, focusing on semantic coherence and pedagogical usefulness. Finally, we present the results of an initial evaluation of the list by stakeholders. The main contributions of the study to p-frame research methodology lie in the clarification of threshold settings, the potential contribution of variability and predictability to decision-making and the proposal of more in-depth concordance analysis of co-text to aid in the identification of phrases.

The Impact of Point-of-Care Ultrasound-Guided Resuscitation on Clinical Outcomes in Patients With Shock: A Systematic Review and Meta-Analysis.

To determine the impact of point-of-care ultrasound (POCUS)-guided resuscitation on clinical outcomes in adult patients with shock. We searched MEDLINE, Embase, and unpublished sources from inception to December 2023. We included randomized controlled trials (RCTs) that examined the use of POCUS to guide resuscitation in patients with shock. We collected data regarding study and patient characteristics, POCUS protocol, control group interventions, and outcomes. We identified 18 eligible RCTs. POCUS slightly influences physicians' plans for IV fluid (IVF) and vasoactive medication prescription (moderate certainty), but results in little to no changes in the administration of IVF (low to high certainty) or inotropes (high certainty). POCUS may result in no change in the number of CT scans performed (low certainty) but probably reduces the number of diagnostic echocardiograms performed (moderate certainty). POCUS-guided resuscitation probably reduces 28-day mortality (relative risk [RR] 0.88; 95% CI, 0.78-0.99), the duration of vasoactive medication (mean difference -0.73 d; 95% CI, -1.16 to -0.30), and the need for renal replacement therapy (RRT) (RR 0.80; 95% CI, 0.63-1.02) (low to moderate certainty evidence), and lactate clearance (high certainty evidence). POCUS-guided resuscitation may results in little to no difference in ICU or hospital admissions, ICU and hospital length of stay, and the need for mechanical ventilation (MV) (low to moderate certainty evidence). There is an uncertain effect on the risk of acute kidney injury and the duration of MV or RRT (very low certainty evidence). POCUS-guided resuscitation in shock may yield important patient and health system benefits. Due to lack of sufficient evidence, we were unable to explore how the thresholds of operator competency, frequency, and timing of POCUS scans impact patient outcomes.

Clonal Hematopoiesis and Clinical Outcomes in Metastatic Castration-Resistant Prostate Cancer Patients Given Androgen Receptor Pathway Inhibitors (Alliance A031201).

Mutations in hematopoietic progenitor cells accumulate with age leading to clonal expansion, termed clonal hematopoiesis (CH). CH in the general population is associated with hematopoietic neoplasms and reduced overall survival (OS), predominantly through cardiovascular adverse events (CVAE). Because androgen receptor pathway inhibitors (ARPI) used in metastatic castration-resistant prostate cancer (mCRPC) are also associated with CVAEs and because CH negatively impacted survival in an advanced solid tumor cohort, we hypothesized that CH in mCRPC may be associated with increased CVAEs and inferior survival. A targeted DNA sequencing panel captured common CH mutations in pretreatment blood samples from 957 patients enrolled in Alliance A031201: a randomized trial of enzalutamide ± abiraterone/prednisone in the first-line mCRPC setting. The primary outcome was the impact of CH on OS; the secondary outcomes were progression-free survival (PFS) and CVAEs. Baseline comorbidities were similar by CH status. No differences in OS/progression-free survival were detected regardless of treatment arm or the variant allele frequency threshold used to define CH [primary: 2% (normal-CH, N-CH); exploratory: 0.5% (low-CH) and 10% (high-CH, H-CH)]. Patients with H-CH (7.2%) and TET2-mutated N-CH (6.0%) had greater odds of any CVAE (14.5% vs. 4.0%; P = 0.0004 and 12.3% vs. 4.2%; P = 0.010, respectively). More major CVAEs were observed in patients with H-CH (5.8% vs. 1.9%; P = 0.042) and N-CH (3.4% vs. 1.8%; P = 0.147). CH did not affect survival in patients with mCRPC treated with ARPIs in A031201. H-CH and TET2-mutated CH were associated with more CVAEs. These findings inform the risk/benefit discussion about ARPIs in mCRPC.

ABO Blood Group and Auditory Function in Young Adults.

In recent years, research on the effect of blood group on hearing function has gained more attention. Some blood groups show susceptibility to certain general health and auditory disorders like noise induced hearing loss, infections, coronary artery disease, gastric carcinoma and duodenal ulcer. The present study aimed to determine the differences in middle ear and cochlear function among persons with different blood groups (AB, A, B, O). Sixty adults (18-24 years) with normal hearing sensitivity were included in the study. They were divided into four groups based on blood groups (A, B, AB, O) with 15 participants each. High-frequency thresholds, distortion product otoacoustic emissions (DPOAE) and resonance frequency were measured. High-frequency thresholds for both ears were measured at octave frequencies from 9kHz to 16kHz. Resonant frequency was determined using sweep frequency method. The findings demonstrated that individuals with blood group AB and O had considerably lower DPOAE amplitudes. Resonance frequency and extended high frequency thresholds did not, however, differ significantly between the blood groups. The decrease in the amplitude of otoacoustic emissions (OAE) can be explained by a reduction in the quantity of robust outer hair cells and elevated protein levels, which in turn lead to a reduction in the cochlear blood flow in persons with blood type O and AB, respectively. More research with greater numbers of participants is necessary to improve the generalization of the findings.

Modulating Wetting States of Molten Aluminum Droplets on SiO2 Surfaces via Vertical Sinusoidal Vibrations.

Vibration affects the wetting behavior of droplets, and it is feasible to use vibration to modulate the adhesion characteristics of droplets. In this paper, the effect of vertical sinusoidal vibrations on the wettability of molten aluminum droplets on the substrate surfaces of smooth and with nanopillars is investigated. The increase in the frequency or amplitude of the vibration leads to a rise in the interfacial potential energy between the molten droplets and the substrate, which in turn leads to the occurrence of the Wenzel-Cassie transition. Once the vibration frequency reaches the threshold values, the molten droplets leave from the substrate, that is, dewetting occurs. The molten droplets in the Wenzel state undergo a Wenzel-Cassie transition before dewetting occurs. A phase diagram describing the frequency thresholds at which the molten aluminum droplets undergo dewetting and the Wenzel-Cassie transition at different amplitudes is plotted. For a specific amplitude, the frequency of vibration required for dewetting to occur in molten aluminum droplets in the Young state is lower than that in the Wenzel state. The needed vibrational frequency for dewetting or the Wenzel-Cassie transition decreases with increasing amplitude.

Study on the impact of active intake air fluctuation on the performance and mass transfer of PEM Fuel Cell

Enhancing mass transfer is imperative for mitigating concentration polarization and thereby optimizing fuel cell performance. This study presents numerical investigation to explore the performance of a proton exchange membrane fuel cell, which involves implementation of actively controlled fluctuating mass fluxes at cathode inlet in order to achieve desirable mass transfer enhancement. The trajectories of liquid droplets within channel were predicted by employing volume of fluid method. The results revealed that the current density exhibits frequency-dependent fluctuations, aligning with input oscillations. A marginal increase in mean current density was observed with frequency amplified and the maximum power density with fluctuated flow increased by 3.9 % compared to that with steady flow inlet. A noteworthy and linear augmentation was evident with amplitude escalation. The mean current density surpassed 34.7 % of the steady current at the amplitude of 10. Beyond a frequency threshold of 1000 Hz, the fluctuating current density surpassed that of steady flow throughout the entire period, attributed to the time constant of gas transport within the gas diffusion layer. Moreover, fluctuation phenomenon of the pressure field within the fuel cell channel, which contributed to reinforced mass transfer and accelerated product alleviation in the region facing bipolar rib was identified during gas transport in the gas diffusion layer. Numerical simulations adopting the volume of fluid method revealed a heightened tendency for the disintegration and expulsion of liquid droplets in the channel attributable to fluctuating flow.

Development and evaluation of a novel user-operated slider-based audiometry method.

To evaluate a novel user-operated audiometry method allowing users full control in determining their pure-tone hearing thresholds. Comparative study. Participants were recruited from a hearing clinic after undergoing manual audiometry (six frequencies). They then performed test-retests of a new test (slider audiometry, eight frequencies) and completed the System Usability Scale questionnaire. 37 adult participants, including 30 hearing-impaired and seven normal-hearing individuals. Mean (SD) threshold differences for octave frequencies between 250 to 2000 Hz between manual and slider audiometry ranged from -7.8 (6.6) to -5.7 (6.5) dB and were significant. For 4000 and 8000 Hz mean differences were -0.3 (8.4) and 0.0 (9.7) dB and insignificant. Standard deviations ranged from 6.5 to 9.7 dB across six tested frequencies. Slider test-retest mean threshold differences ranged from -1.4 (4.7) to 0.3 (6.0) dB across eight tested frequencies, with standard deviations ranging from 4.1 to 8.5 dB. The average usability score for the slider audiometry was 88.3. When compared to manual audiometry, the slider audiometry demonstrated validity at 4000 and 8000 Hz but found significantly lower thresholds for octave frequencies between 250 to 2000 Hz. Test-retests of the new method revealed small mean differences and acceptable SDs.

CELEBRIMBOR: core and accessory genes from metagenomes.

Metagenome-Assembled Genomes (MAGs) or Single-cell Amplified Genomes (SAGs) are often incomplete, with sequences missing due to errors in assembly or low coverage. This presents a particular challenge for the identification of true gene frequencies within a microbial population, as core genes missing in only a few assemblies will be mischaracterized by current pangenome approaches. Here, we present CELEBRIMBOR, a Snakemake pangenome analysis pipeline which uses a measure of genome completeness to automatically adjust the frequency threshold at which core genes are identified, enabling accurate core gene identification in MAGs and SAGs. CELEBRIMBOR is published under open source Apache 2.0 licence at https://github.com/bacpop/CELEBRIMBOR and is available as a Docker container from this repository. Supplementary material is available in the online version of the article.