Crossover Points Research Articles

Plant sperm cell sequencing for genome phasing and determination of meiotic crossover points.

Haplotype phasing represents a pivotal procedure in genome analysis, entailing the identification of specific genetic variant combinations on each chromosome. Achieving chromosome-level genome phasing constitutes a considerable challenge, particularly in organisms with large and complex genomes. To address this challenge, we have developed a robust, gamete cell-based phasing pipeline, including wet-laboratory processes for plant sperm cell isolation, short-read sequencing and a bioinformatics workflow to generate chromosome-level phasing. The bioinformatics workflow is applicable for both plant and other sperm cells, for example, those of mammals. Our pipeline ensures high-quality single-nucleotide polymorphism (SNP) calling for each sperm cell and the subsequent construction of a high-density genetic map. The genetic map facilitates accurate chromosome-level genome phasing, enables crossover event detection and could be used to correct potential assembly errors. Our bioinformatics pipeline runs on a Linux system and most of its steps can be executed in parallel, expediting the analysis process. The entire workflow can be performed over the course of 1 d. We provide a practical example from our previous research using this protocol and provide the whole bioinformatics pipeline as a Docker image to ensure its easy adaptability to other studies.

Molecular dynamics analysis of the crossover phenomenon in supercritical carbon dioxide

Supercritical carbon dioxide (SCO2) finds widespread applications but its complex phase behavior near and beyond the critical point remains unclear. In this work, extensive focus has been invested in the thermodynamic transitions of SCO2 from a microscopic perspective. It is revealed that both the radial distribution function and structure factor exhibit apparent crossover phenomena as temperature changes. Remarkably, our findings demonstrate an unprecedented agreement between the predicted crossover points using different functions and the experimental Frenkel Line (FL), with a deviation of merely 5.6%. By applying the same method, the FL crossover region is successfully predicted and extended up to an impressive pressure of 200 MPa. Notably, this prediction is a valuable guide in narrowing down the temperature range for further experimental tests. Concurrently, a correlation between the coordination number and the FL is discovered. Overall, our research provides compelling evidence supporting the FL as thermodynamic transitions between the gas-like and liquid-like regions and presents a novel and reliable approach for identifying the FL, which offers valuable theoretical insights into the phase behavior in the supercritical state.

Multifractal Analysis of the Impact of Fuel Cell Introduction in the Korean Electricity Market

This study employs multifractal detrended fluctuation analysis to investigate the impact of fuel cell introduction in the Korean electricity market via the lens of multifractal scaling behavior. Using multifractal analysis, the research delineates discrepancies between peak and off-peak hours, accounting for the daily cyclicity of the electricity market, and proposes a crossover point detection method based on the Chow test. Furthermore, the impacts of fuel cell introduction are evidenced through various methods that encompass multifractal spectra and market efficiency. The findings initially indicate a higher degree of multifractality during off-peak hours relative to peak hours. In particular, the crossover points emerged solely during off-peak hours, unveiling short- and long-term dynamics predicated on a near-annual cycle. Additionally, the average Hurst exponent for the short-term was 0.542, while the average for the long-term was 0.098, representing a notable discrepancy. The introduction of fuel cells attenuated the heterogeneity in the scaling behavior, which is potentially attributable to the decreased volatility in both the supply and demand spectra. Remarkably, after the introduction of fuel cells, there was a discernible decrease in the influence of long-range correlation within multifractality, and the market exhibited an increased propensity toward random-walk behavior. This phenomenon was also detected in the market deficiency measure, from an average of 0.536, prior to the introduction, to an average of 0.267, following the introduction, signifying an improvement in market efficiency. This implies that the introduction of fuel cells into the market engendered increased supply stability and a consistent increase in demand, mitigating volatility on both the supply and demand sides, thus increasing market efficiency.

Rapid investment casting: a techno-economic analysis for evaluating VAT photopolymerisation processes

Adopting additive manufacturing in investment casting, known as rapid investment casting, can significantly reduce lead time and cost. Despite many publications on these technologies, no quantitative techno-economic analyses refer to rapid investment casting. The paper provides helpful insights and a decision-making approach for replacing conventional production technologies (i.e. wax injection) with additive manufacturing technologies. The study is based on a techno-economic analysis framework. It allows assessing key performance indicators (e.g. crossover points and payback periods) for stakeholders to decide the suitable VAT photopolymerisation processes (i.e. stereolithography, digital light processing, and material jetting) according to specific production scenarios (i.e. load factors). Analytical cost models were developed in the frame of this work to assess the time and cost of the overall manufacturing process of the resin model for investment casting, considering the post-processing stages for each of the technologies investigated. The cost models were used to assess the benefits introduced by additive manufacturing in rapid investment casting. A sensitivity analysis evaluated the impact of energy, material, and labour costs for both key performance indicators (crossover points and payback periods). The techno-economic analysis yielded the following results: (i) crossover points in terms of production costs vary, ranging from thousands of units for small components in the jewellery or fashion industries to a few dozen units for larger parts in the mechanical industry, and (ii) crossover points in terms of time are lower than those related to cost. Additionally, digital light processing is regarded as the most promising technology, offering the best crossover points and payback periods across various scenarios, mainly when 3D printers are used at a low utilisation rate.

Multidimensional Evaluation of Altimetry Marine Gravity Models with Shipborne Gravity Data from a New Platform Marine Gravimeter

With the development of satellite altimetry technology and the application of new altimetry satellites, the accuracy and resolution of altimeter-derived gravity field models have improved over the last decades. Nowadays, they are close enough to shipborne gravimetry. In this paper, multi-source shipborne gravity data in the South China Sea were taken to evaluate the accuracies of two high-precision altimeter-derived marine gravity field models (SS V30.1, DTU17). In these shipborne gravity data, there are dozens of routes’ ship gravimetry data, obtained from the National Geophysical Data Center (NGDC); data were tracked from a marine survey with a commercial marine gravimeter (type KSS31M), and data were tracked from a marine gravimetry campaign that was conducted with a newly developed platform gravimeter (type JMG) in the South China Sea in September 2020. After various data filtering, processing, and calibrations, the shipborne gravity data were validated with crossover points analysis. Then, the processed shipborne data were employed to evaluate the accuracy of the altimeter-derived marine gravity field models. During this procedure, the quality of JMG shipborne gravity data was compared with the results of KSS31M and NGDC data. Analysis and evaluation results show that the crossover points verification accuracies of KSS31M and JMG are 0.70 mGal and 1.61 mGal, which are much better than the accuracy of NGDC, which is larger than 8.0 mGal. In the area where the bathymetry changes slowly, the root mean square error values between altimetry gravity models and KSS31M data are respectively 3.28 mGal and 4.54 mGal, and those of the JMG data are respectively 2.94 mGal and 2.60 mGal. According to the above results, we can conclude that the JMG has the same 1–2 mGal accuracy level as KSS31M and can meet the measurement requirements of marine gravity.

Spin magnetotransport in rare-earth iron garnet (REIG)/Pt: Effects of modulated bulk and REIG/Pt interfaces

The intrinsic magnetization compensation behaviors of rare-earth iron garnets (REIGs) make the material promising for applications in ultrafast spin storage devices. REIG/heavy metal heterostructures such as TbIG/Pt often display two sign crossovers of anomalous Hall effect resistance with varying temperatures. One of these crossovers is attributed to the magnetization compensation of REIG, and the other to the competition between the magnetic proximity effect and the spin Hall effect. Here, we design trilayer REIG heterostructures based on two rare-earth species (Tb and Eu). We modulate the layer stacking of the TbIG/EuIG/TbIG sandwich with a fixed total thickness and explore the contributions of REIG bulk and REIG/Pt interfaces on these two crossover points. As TbIG gradually moves away from Pt, the compensation temperature shows some fluctuations. However, when TbIG is entirely out of contact with Pt, the second crossover point undergoes a change that shows REIG/Pt interface dependency. The results highlight the dominance of REIG bulk on the compensation behavior and the interface sensitivity of the second crossover point. This study provides a reference for designing controllable spintronics devices, such as magnon valve applications.

Impact of temperature on ophthalmic viscosurgical devices and clinical implications: a pilot study.

To evaluate how temperature affects the rheology of common ophthalmic viscosurgical devices (OVDs) and clinical implications. Tennent Institute of Ophthalmology, Glasgow, with Department of Mechanical and Aerospace Engineering, and Advanced Materials Research Laboratory, University of Strathclyde, Glasgow, United Kingdom. Laboratory pilot study. The viscous and elastic responses of 3 OVDs (Eyefill-SC/Eyefill-C/Eyefill-HD) were measured using rotational and extensional rheometers at clinically relevant temperatures (5°C, 25°C, 37°C). Thermal properties were evaluated using differential scanning calorimetry and laser-flash analysis. The OVDs tested exhibited viscoelastic properties and shear-thinning behavior. Apparent viscosities and relaxation time were higher at lower temperatures. The Eyefill-C and Eyefill-SC exhibited predominantly viscous character at low frequencies with a transition to predominantly elastic behavior at high frequencies. An increase in temperature led to a decrease in relaxation time under shear and extension. At low frequencies, Eyefill-C and Eyefill-SC moduli increase with decreasing temperatures. Eyefill-HD at 25°C and 37°C displays 2 crossover points, with the storage modulus dominating at low and high frequencies indicating a predominantly elastic behavior. Thermal property analysis revealed Eyefill-C had the lowest thermal conductivity. This pilot study confirms our clinical experience that OVD properties are affected by low temperatures, with increased viscosities at low shear rates and higher relaxation times. Cold OVD can cause greater resistance to initiation of intraocular lens (IOL) injection system forces (compared with warmer OVD). Excessively forced injection using cold OVD could contribute to inadvertent cannula detachment if incorrectly assembled, or uncontrolled IOL release leading to avoidable injury.

Analysis of stage parameters of low-temperature oxidation of water-soaked coal based on kinetic principles

Mine fires caused by spontaneous coal combustion are major disasters in coal mines. The staged oxidation kinetic parameters of various coal samples at oxygen concentrations of 21 %, 15 %, 10 %, 5 %, and 3 % were analyzed using a programmed temperature testing system. Herein, the temperature increase rate of coal, the temperature difference between the furnace and coal, and the oxygen consumption characteristics were obtained. Based on the amount of CO produced and the temperature sensitivity coefficient, three characteristic temperatures and four stages of low-temperature oxidation (LTO) were identified. The results showed that at a critical temperature (TC), the amount of CO gas released from the coal samples increased with increasing oxygen concentration, and the difference in the oxygen consumption rate increased. After the limit temperature (Tu), the amount of CO gas increased steadily, and the increase in the oxygen consumption rate stagnated. CO production, the maximum heating rate, and the maximum heat release rate were positively correlated with the oxygen concentration. As the oxygen concentration increased, the activation energy during the oxygen absorption stage gradually decreased. The average reaction enthalpy (ΔH) of pre-oxidized water-immersed coal was 19.37 kJ/kg greater than that of raw coal. The equation for the conservation of energy of the coal oxidation warming process was normalized. The theoretical values of the awakening stage and the stable stage were τν and τν (1-B), respectively. When B was >1, pre-oxidized water-immersed coal at a low oxygen concentration was prone to crossover points during the oxygen absorption stage, which increased the risk of coal spontaneous combustion (CSC). The research results could provide a theoretical basis for the staged control of the spontaneous combustion of water-immersed coal in goaf areas.

Meta-heuristic algorithms for integrating manufacturing and supply chain functions

This study proposes an integrated framework that incorporates essential manufacturing and supply chain functions. These functions encompass process planning, scheduling, due-date assignment, and delivery optimization. The objective of this integrated approach is to achieve multiple benefits, including balanced workload distribution, enhanced company performance, generation of more realistic planning schedules, and ultimately, the achievement of shorter due dates. As a result, the overall efficiency of operations is substantially improved, with approximately a 50 % increase over isolated function management. Additionally, the isolated integration of the delivery function within systems comprising three integrated functions has been found to improve efficiency by 18%. The study employs various heuristic techniques, including genetic algorithms, simulated annealing, random search, hybrid search, and evolutionary strategy, to assess the optimal solution method and rules for these functions. The Taguchi technique is employed to ascertain the optimal values for critical parameters, such as population size, mutation rate, crossover points, and random search rate. Among the solution methods investigated, genetic algorithms consistently yielded superior results Additionally, the weighted slack rule consistently exhibited notable effectiveness compared to other due-date assignment rules. Similarly, the savings algorithm outperformed other delivery optimization rules. However, it is important to note that among the scheduling rules evaluated, none has emerged as dominant.

High spatial resolution elevation change dataset derived from ICESat-2 crossover points on the Tibetan Plateau

Understanding elevation changes on the Tibetan Plateau is crucial to comprehend the changes in topography, landscape, climate, environmental conditions, and water resources. However, some of the current products that track elevation changes only cover specific surface types or limited areas, and others have low spatial resolution. We propose an algorithm to extract ICESat-2 crossover points dataset for the Tibetan Plateau, and form a dataset. The crossover points dataset has a density of 2.015 groups/km², and each group of crossover points indicates the amount of change in elevation before and after a period of time over an area of approximately 17 meters in diameter. Comparing ICESat-2 crossover points data with existing studies on glaciers and lakes, we demonstrated the reliability of the derived elevation changes. The ICESat-2 crossover points provide a refined data source for understanding high-spatial-resolution elevation changes on the Tibetan Plateau. This dataset can provide validation data for various studies that require high-precision or high-resolution elevation change data on the Tibetan Plateau.

Sensitivity analysis of multipactor susceptibility zone to variations in secondary electron yield values

We present a sensitivity analysis of the multipactor susceptibility zones to variations in the secondary electron yield (SEY) of materials, specifically focusing on the first and second unity crossover points of SEYs. In conducting this research, we leveraged our semi-analytic approach, which allows for the rapid prediction of the full multipactor zones with enhanced accuracy. Using this approach, we unveil several unique features of multipactor susceptibility zones, including the infinite extension of different-order multipactor zones and the overlap between them. Building upon this prediction capability, our results complement previous findings on the same topic and reveal that the multipactor zones depend not only on the first crossover point but also on the second crossover point of SEY, which this latter predominantly impacts multipactor susceptibility zones for low SEY materials. To validate our predictions, we present two distinct sets of multipactor experiments, providing empirical support for our results.

Precise Orbit Determination of the MESSENGER Spacecraft

The NASA MESSENGER mission explored Mercury for more than four years to investigate the properties of the planet. To safely operate in the harsh conditions around Mercury, the spacecraft was in a highly eccentric orbit with a low periapsis altitude. The radiation environment had a strong impact on the spacecraft orbit evolution because of the proximity of Mercury to the Sun. A detailed modeling of the nonconservative forces is then a key factor to enhance the precise orbit determination of the spacecraft. We present here refined models of the nonconservative forces, including thermal reradiation effects, that enabled significant improvements in the trajectory reconstruction. A crossover analysis based on the Mercury Laser Altimeter (MLA) data was carried out to cross-check the accuracy of the orbit determination results. The trajectories retrieved by using the refined spacecraft dynamical model provide reduced height misfit at crossover points, indicating a high-quality reconstruction. Our new solutions of the spacecraft orbits are then archived to be used as auxiliary information for the data analysis of other MESSENGER instruments.

Exploring the ED50 and ED95 of Remimazolam for Laryngeal Mask Airway Insertion During General Anesthesia in Pediatric Strabismus Correction Surgery.

Remimazolam, known for its rapid onset, quick metabolism, and short recovery time from sedation, offers significant advantages in clinical anesthesia. Previous studies have primarily investigated its application in adult surgical anesthesia, with less focus on its utilization in pediatric patients. Therefore, we aimed to explore the 50% effective dose (ED50) and 95% effective dose (ED95) of remimazolam for laryngeal mask airway (LMA) insertion during general anesthesia in pediatric strabismus correction surgery and investigate its dose-response relationship, thereby providing valuable reference data for safer and more rational clinical use of remimazolam. This study included 32 patients aged 3-12 years undergoing strabismus correction surgery at Ningbo Aier Guangming Eye Hospital in 2024. The dosage of remimazolam was determined according to the Dixon 'up-and-down' sequential method: the starting induction dose was 0.2 mg/kg, with a step dose of 0.05 mg/kg. In cases of positive anesthetic effect, the subsequent patient received a reduced step dose, while in cases of negative anesthetic effect, the next subject received an increased step dose. The trial was terminated upon observing seven "positive-negative" crossover points. Furthermore, the ED50 and ED95, along with their 95% confidence intervals (95% CI) were calculated using the Probit regression analysis. Additionally, vital signs of the patients, such as peripheral oxygen (SpO2), heart rate, and blood pressure, along with the incidence of adverse events, were monitored. The ED50 of remimazolam for LMA insertion in pediatric strabismus correction surgery was 0.300 mg/kg (95% CI 0.276-0.323 mg/kg), and the ED95 was 0.369 mg/kg (95% CI 0.324-0.414 mg/kg). Throughout the surgery, SpO2, heart rate, and blood pressure remained stable without any significant fluctuations. The ED50 and ED95 of remimazolam for LMA insertion in pediatric strabismus correction surgery are 0.300 mg/kg and 0.369 mg/kg, respectively. This study demonstrates that remimazolam is both safe and effective for LMA insertion during general anesthesia in pediatric strabismus correction surgery.

Lightweight Video-Based Respiration Rate Detection Algorithm: An Application Case on Intensive Care

The video-based non-contact respiration detection technology can be used in many application scenarios to unobtrusively and ubiquitously monitor the physical state of living beings, and various researchers are currently working on this technology. The optical flow method in tandem with crossover point method is rather effective for respiration rate extraction. However, each method has one disadvantage: 1) the redundant feature points in the traditional optical flow method increase the computational effort and reduce the estimation accuracy; and 2) the traditional crossover point method suffers from crossover points unrelated to breathing movements. For these two challenges, two optimization points are proposed in this work: 1) optimize feature point space by combining spatio-temporal information; and 2) use negative feedback design to adaptively remove crossovers that are not related to respiratory movements. The performance of the proposed algorithm is validated by the Large-scale Bedside Respiration Dataset for Intensive Care (LBRD-IC), which is established using the actual surveillance videos acquired from ICU wards. The validity of the above two optimization points is verified by the ablation experiments. The influential analysis of computation time and video resolution on the performance of the proposed algorithm demonstrates that the proposed algorithm can be deployed to various application terminals to monitor the respiration rate of living organisms in real-time and with high accuracy. In addition, field measurements in the ICU ward have shown that our algorithm can measure respiratory signals of the single patient and multiple patients when only one surveillance camera is present. The dataset and the code are publicly available at: <uri xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">https://github.com/ShawnTan86/LBRD-IC-Dataset</uri> .

Surface-gas chemistry coupling and stability limits of hydrogen/air combustion in catalytic microchannels

The catalytic (heterogeneous) and coupled catalytic-gaseous (hetero-/homogeneous) combustion of fuel-lean hydrogen/air mixtures (equivalence ratio φ = 0.4) in palladium- and rhodium-coated catalytic microchannels was numerically investigated in planar microchannels having a canonical geometry of 10 mm length and 1 mm height. Steady, extinction-induced combustion stability limits were demarcated as a function of inlet velocity and external heat loss at pressures of 1 and 5 bar, with wall thermal conductivities of 1 and 16 W/mK. In each case, interplays between the catalytic and gas-phase chemical reaction pathways, and their impact on the stability limits were identified. The stability results were further compared with literature data for platinum. The simulations indicated that Pd was more resilient against extinction than Rh and had a stronger surface reactivity when competing with gas-phase chemistry in the channel. Similar to Pt, the strong H2 surface reactivity on Pd resulted in wide stability limits purely determined by surface reactions and independent of gas-phase chemistry. In stark contrast, the presence of gas-phase combustion significantly expanded the stability limits of the Rh channel. The stability limits of Rh at 5 bar were consistently broader than those at 1 bar under all investigated conditions, which was also a behavior different to that of Pd and Pt channels, whose stability limit curves had crossover points between the two pressures. Additional simulations were performed in a Surface Perfectly Stirred Reactor (SPSR), providing comprehensive chemistry information, including sensitivity analyses of key reactions and surface coverages. When approaching extinction, OH(s) was a major surface species on Pd, while the Rh surface was primarily blocked by O(s).

Напрестольный крест 1603/04 г. из Покровского монастыря в Суздале: Идентификация вкладчика

The paper reconsiders the issue of the attribution of the eight-pointed reliquary cross made of silver (gilded) and decorated with stamped images on its front side. The votive inscription on the artefact says that the cross was donated to the Suzdal Monastery of the Intercession of Our Lady in 1603/04, with the style of figurative images, foliage pattern and the high quality of work clearly indicating the Moscow origin of this liturgical object. As of presently, the identity of the donator has been believed to be unclear, although the inscription is reliably readably and contains both his names and all information necessary for identification. Many people of Medieval Rus’ had two lay Christian names - today, this idea comes as less of surprise to researchers as it used to a decade earlier, yet the tradition of lay Christian binominality is still to be described and analyzed. There are two aspects to it, equally fascinating: revealing the general structure and the semantics of this bizarre practice and simply replenishing the collection by establishing the very fact that this or that person, often notable, bore not just the name under which everyone knows them, found in history textbooks, but had another name, perhaps even more important from their own perspective. This last task of studying specific cases sometimes requires almost detective investigation, and challenges faced by a researcher are not incidental: they are rooted in the very ways how this system of lay Christian binominality functioned in the pre-Petrine Rus’: the same person could appear under one name in one case and under the other name in another, and sometimes it is really challenging to find the crossover points allowing to identify, say, Cosmas, servant of God with Prince Dmitry Mikhailovich Pozharsky. The historical and onomastic analysis of the inscription on the 1603/04 cross not only allows to reliably identify the owner of this precious specimen of early 17th –century jewellery but also to make some guesses about the circumstances of donation and to clarify our evidence of naming practices characteristic of the 16th -century Rus’.

Circulation of picobirnavirus in Neotropical free-ranging mammals.

Picobirnavirus (PBV) is a family of non-enveloped double-stranded RNA viruses with bisegmented genomes. Segment 1 encodes the capsid protein and segment 2 encodes RNA-dependent RNA polymerase. They exhibit high genomic heterogeneity and infect a wide range of vertebrate hosts, including humans. The objective of this study was to expand our knowledge of the circulation of PBV in free-living animals from two regions (Brazil and Argentina) of the Atlantic Forest. Fecal samples were analyzed from free-living animals: tapir, brocket deer, peccary, and different species of rodents and marsupials. A total of 133 samples were collected and analyzed by RT-PCR, of which 44 (33.08%) were PBV-positive. Nine amplicons were sequenced, five species from Argentina and four from Brazil, and phylogenetic analysis was performed. The nucleotide and amino acid identities of the PBV strains detected in animals from Argentina and Brazil were between 66.3% and 82.5% and between 55.3% and 74.2%, respectively. The analysed strains presented conserved nucleotide blocks without distinction of the host species. The phylogenetic tree showed that PBV strains from Atlantic Forest animals belonging to genogroup I were grouped into different clusters, without defining groups according to host species (human or animal) or the geographical area of detection. This is the first study on PBV in free-living animals in the Atlantic Forest. Our analysis suggested that PBV strains can infect different animal species, leading to PBV transmission between animals and humans. This reinforces the hypothesis of previous crossover points in the ecology and evolution of heterologous PBV strains.

Effect of aspect ratio on mean flow characteristics of cruciform orifice jet

PurposeThe purpose of this study reports the effects of aspect ratio (AR) on mean flow characteristics of the cruciform orifice jet.Design/methodology/approachThe aspect ratio is the height-to-width ratio of the lobe of the cruciform shape. The aspect ratios considered are 0.25, 0.5, 0.75, 1, 2, 3 and 4. The turbulent jet flow is issued through an orifice being fitted to the jet tunnel facility. The velocity measurements are recorded with the help of pitot-static tube connected to a digital manometer setup. The Reynolds number calculated using the equivalent diameter 50.46 × 10–3 m and exit velocity 51.23 m/s was 1.75 × 105. Based on the experimental data, the streamline velocity decay plots, the potential core length (PCL), mean velocity profiles and velocity half widths were plotted, and discussions were made based on the measured data. A smoke-based flow visualization was carried out at moderate Reynolds number 5396.FindingsThe PCL remains almost constant for the aspect ratio 0.25:1 and then starts decreasing for the aspect ratio 1:4. The decrease in PCL indicates improved mixing. The off-center peaks are found along the major axis in mean velocity profiles for almost all cruciform jets. More than one axis switching occurs and can be identified by the crossover points. The location of the first crossover point shifts forward, and the second crossover point shows an oscillating trend. The flow visualization exhibits the jet evolution, and the distance up to which the jet maintains the cruciform shape is increased with the aspect ratio.Research limitations/implicationsThe experiments are limited to air in air jet under isothermal conditions.Social implicationsThe cruciform orifices can be used as fuel injectors and in air-conditioning systems, thereby improving efficiency and energy usage.Originality/valueThe aspect ratio effects on PCL and axis switching are used to explain the mixing characteristics. Flow visualization was also used to support the discussion.

Study on Self-Humidification in PEMFC with Crossed Flow Channels and an Ultra-Thin Membrane.

In this study, a 3D model of a proton exchange membrane fuel cell (PEMFC) with crossed channels and an ultra-thin membrane is developed to investigate the feasibility of self-humidification; experiments utilizing a PEMFC stack with identical configurations are conducted to validate the simulation results and further investigate the effects of various operating conditions (OCs) on self-humidification. The results indicate that the crossed flow channel leads to enhanced uniformity of water distribution, resulting in improved cell performance under low/no humidification conditions. External humidifiers for the anode can be removed since the performance difference is negligible (≤3%) between RHa = 0% and 100%. Self-humidification can be achieved in the stack at 90 °C or below with an appropriate back pressure among 100-200 kPa. As the current density increases, there is a gradual convergence and crossing of the voltage at low RH with that at high RH, and the crossover points are observed at 60-80 °C with suitable pressure when successful self-humidification is achieved. Below the current density of the point, the stack's performance is inferior at lower RH due to membrane unsaturation, and conversely, the performance is inferior at higher RH due to flooding; this current density decreases with higher pressure and lower temperature.

A critical study of the nonlinear rheological properties in major classes of foods using the Sequence of Physical Processes (SPP) method and the Fourier Transform Coupled with Chebyshev Decomposition (FTC) method

The nonlinear rheological behaviors of three different classes of foods (emulsion, suspension, and elastic network) were studied and analyzed using the Rogers Sequence of Physical Processes (SPP) method and the Ewoldt-McKinley method of coupling Fourier Transform with Chebyshev Decomposition (FTC). SPP analysis led to instantaneous rheological parameters G′t and G″t at any point in time, providing a more accurate picture of the linear viscoelastic region and crossover points by the 3D amplitude sweep. When G′t is plotted against G″t, the resulting graph is a deltoid which offers a detailed and distinctive intracycle behavior of each class of food. Analyzing the revolution of deltoids with increasing strain allows for the determination of a critical strain, beyond which irreversible network breakdown occurs. The strain range between the linear viscoelastic limit and the critical strain found in SPP is comparable to the MAOS region as determined with FTC. Under increasing amplitude, predominantly elastic networks showed a gradual structural rearrangement, while more erratic and abrupt changes were observed in the suspension and emulsion we studied. Under increasing frequency, elastic responses dominate viscous responses in all samples due to the shorter experimental time, allowing less relaxation.