Dispersion In Range Research Articles

Monte Carlo simulations of the fracture resistance of an asphalt pavement layer

The purpose of the proposed numerical model is to analyze the cracking of the wearing course in a pavement overlay, assuming a pre-existing crack that passes through the binding layer and base. The computations employed the author's simulation-based Monte Carlo material model, which describes the failure process of a Semi-Circular Bend (SCB) specimen during standard laboratory testing of asphalt concrete. A key feature of this model is the incorporation of the random nature of material parameters, allowing for the simulation of result dispersion when analyzing a sufficiently large population of samples. The proposed FEM model and obtained material data were directly applied to the numerical analysis of the pavement structure. The comprehensive computational algorithm allows for a random description of the load that induces crack propagation in the pavement wearing course, leading to the creation of a histogram that defines the range of failure load dispersion. Such supporting calculations can assist in optimizing asphalt mix design and, in the future, may allow for the estimation of pavement structure reliability.

A preliminary experimental study on atomization rainfall properties by two-jet collision in high dam discharge

The energy dissipation method commonly employed for flood discharge in high dams involves the collision of jets in the air. This approach frequently results in the issue of flood discharge atomization. This study experimentally investigates the rainfall characteristics resulting from the interaction between a surface-orifice jet and a deep-orifice jet during high dam discharges. The research explores various flow rate ratios and collision angles of the two jets, focusing on the spatial distribution of rainfall intensity, as well as the size and velocity of droplets post-collision. The findings revealed that the rainfall distribution on the horizontal plane resembles a mushroom cloud, with the maximum rainfall intensity at the center. Increasing the collision angle between the jets significantly increases the dispersion range of atomized rainfall, while the maximum intensity decreases. Additionally, as the jet flow rate ratio increases, the dispersal range of rainfall initially expands before stabilizing, with relatively minor variations in intensity. Following a two-jet collision, the trajectory of the jet was derived, and the associated parameters were determined using experimental data. The probability distributions for droplet size and velocity closely approximated Gaussian distributions. The study also observed that the number of droplets per unit time, along with the ensemble-averaged diameter and velocity, initially increases and then decreases longitudinally. Meanwhile, the number of droplets per unit time gradually decreases in the lateral direction, while the ensemble-averaged diameter and velocity remain relatively constant. Furthermore, with an increase in the jet flow rate ratio, both the ensemble-averaged diameter and velocity of droplets follow a pattern of initial increase and subsequent decrease, while the collision angle has no significant impact.

Composite Risk Assessment of HNS Discharged from Marine Industrial Facilities: A Case Study on Incheon Port, South Korea

This study conducted a composite risk assessment to evaluate the environmental impacts of phenol, a Hazardous and Noxious Substance (HNS) released or leaked from port facilities. The study area was designated as the vicinity of Incheon Port, South Korea, where the volume of petrochemical-related materials is substantial and various industrial facilities are located. For the composite risk assessment, various vulnerability maps were developed, incorporating the dispersion range of phenol calculated through numerical modeling. The vulnerability maps were generated by classifying socio-environment, legally protected areas, habitats, and species, followed by integrating these individual vulnerability maps to construct an integrated vulnerability map. The composite risk assessment was conducted by considering both the integrated vulnerability map and the dispersion range of phenol. The assessment results indicated that the highest risk by depth was observed in the lower layers due to the settling characteristics of phenol. Spatially, areas where islands and coastlines converge exhibited relatively higher risks. This was attributed to the high concentrations of phenol released from industrial facilities, such as crude oil refineries, petrochemical plants, and organic compound manufacturers, in regions characterized by intense human activity, sensitive habitats, and legally protected areas. Continuous monitoring of these high-risk areas is crucial for assessing the environmental impacts of HNS substances like phenol.

The effect of environmental and anthropogenic factors on the microbiome of the sponge, Halichondria panicea, at three coastal sites with different bathing water quality in North east England

The breadcrumb sponge, Halichondria panicea, is a cosmopolitan marine species. Life functions, such as feeding, metabolism and defence, are maintained through microbial symbiosis. As such, perturbations to the symbiotic balance can be expected to affect the health and survival of the sponge. Although generally tolerant of environmental variables, such as temperature, pH and salinity, responses to anthropogenic factors are poorly understood. In this study, the microbial community of the H. panicea was examined over the course of 1 year. Sponge and seawater samples were collected in January, April, July and October 2022, from three locations with different levels of bathing water quality, according to the UK’s Environment Agency. Samples were sequenced using the 16S ribosomal RNA (rRNA) gene, and amplicon sequence variants (ASVs) were inferred from the generated data. Differences in bacterial diversity and abundance among sponge samples from the three locations were examined. A correlation test was used to study the effect of physical and chemical environmental factors along with faecal indicator bacteria on the abundance of the top ten most abundant bacterial phyla. Environmental factors (determined from seawater physicochemical properties) and pollution (determined from trace metals, nutrients and faecal bacteria levels) were found to play an important role in shaping the microbial community of this sponge. The sponge microbiome showed a noticeable seasonal shift, with some species flourishing in January and others emerging in April, notably the faecal and coliform bacteria. Sponge microbiomes from sites with poor-quality bathing water were generally less diverse and had lower microbial abundance, resulting in a greater range of intra-species dispersion than those of sponges living in excellent–good quality waters.

Post-release dispersal and home range of translocated red deer in the Vojvodina province (Serbia)

Monitoring of 38 (12 male and 26 female) red deer translocated from Ivo Wildlife Park (Romania) to hunting ground "Bosutske Forest" (Vojvodina, Serbia) was conducted from 2017 to 2021. The red deer were translocated in lieu of the managing authority's efforts to counteract the effects of red deer losses due to catastrophic flooding in the region. All animals were ear-tagged, while 7 males and 10 females were fitted with GPS collars. A total of 2,288 valid signals were analyzed (565 from males and 1,723 from females). In addition, 1,333 sighting records were collected from eight observation posts (480 in 2019, 670 in 2020 and 183 in 2021). We determined the movements and spatial distribution of translocated animals in the new habitat and estimated their home range sizes. Home range was calculated using the minimum convex polygon method, while the core area was calculated using the kernel density estimator method. The greatest straight-line distance from the acclimatisation enclosure was essentially the same for both sexes (average 6.0 km for males and 6.4 km for females). A non-significant relationship existed between the number of days in captivity and the greatest straight-line distance, as well as between days in captivity and the core area of the home range. The estimated home range of males was 12.8 km2 (range 0.2‒36.1), smaller than that of females (20.6 km2, range 0.4‒68.7), but this difference was not statistically significant. Observations made independently showed mostly herds of 4 to 6 individuals (52.3%), while large herds (≥ 10 individuals) were rare. Participation of translocated and resident animals in mixed herds was common during the monitoring period (62.3%). Our results showed that a high level of acceptance of the new habitat and social cohesion between translocated and resident animals was achieved. We believe that this is due to two main reasons: firstly, the long-term stay in a large acclimatisation enclosure prior to release and secondly, year-round supplemental feeding coupled with an abundant natural food supply in this unique forest area also contributed to successful acclimatisation. Keywords: Cervus elaphus; population; habitat; home range size; red deer; management

Role of the inverse Čerenkov effect in the formation of ultrashort Raman solitons in silica microspheres.

We theoretically demonstrate a new regime, to the best of our knowledge, of the formation of ultrashort optical solitons in spherical silica microresonators with whispering gallery modes. The solitons are driven by a coherent CW pump at the frequency in the range of normal dispersion, and the energy is transferred from this pump to the solitons via two channels: the Raman amplification and inverse Čerenkov effect. We discuss three different regimes of soliton propagation and we also show that these Raman solitons can be controlled by weak coherent CW signals.

Gibbs Dynamics for Fractional Nonlinear Schrödinger Equations with Weak Dispersion

We consider the Cauchy problem for the one-dimensional periodic cubic nonlinear fractional Schrödinger equation (FNLS) with initial data distributed via its associated Gibbs measure. We construct global strong solutions with the flow property for the FNLS on the support of the Gibbs measure in the full dispersive range, thus resolving a question proposed by Sun and Tzvetkov (Nonlinear Anal 213, paper no. 112530, 2021). As a byproduct, we prove the invariance of the Gibbs measure and almost sure global well-posedness for FNLS.

Simulation of LNG tank container leakage and dispersion on anchoring inland carrying vessel

Liquified Natural Gas (LNG) is becoming an important energy source as clean energy. In cities with inland waterways, LNG tank containers transported by inland vessels will be the primary mode of transportation. However, the night sailing of LNG carriers is typically prohibited considering the safety of the vessels and surroundings. Inland LNG tank container carriers have to wait at specific anchorages during the prohibition period and complete the full voyage in segments. During the anchoring phase, the vessels pose significant risks with LNG leakage and dispersion as the primary ones. In this study, taking the anchoring LNG tank container carrier in the Yangtze River in China as a case study, a comparative simulation study is performed using the computational fluid dynamics model to investigate the influencing risk factors. The leakage and dispersion of LNG under extremely unfavorable conditions are also analyzed to calculate the safety area and provide the corresponding safety management suggestions. The comparative analysis results indicate that the leakage aperture is the primary influential factor, followed by wind speed and temperature. The simulations under extremely unfavorable conditions reveal a maximum dispersion range of 190 m and a safety zone radius of 310 m. These results provide important technical guidance and reference values for the case of leakage and dispersion on inland waterways.

P195 CARDIOVASCULAR OUTCOMES IN PATIENTS WITH AORTIC STENOSIS AND HYPERTENSION UNDERGOING AORTIC VALVE REPLACEMENT

Background and Objective: Aortic valve stenosis (AS) is most common valvular heart disease and in its severe form requires aortic valve replacement (AVR). The prevalence of both AS and arterial hypertension (HTN) increases with age and the conditions therefore often co-exist. Co-existence of AS and HTN is associated with higher global left ventricular (LV) pressure overload, more abnormal LV geometry and function, and more adverse cardiovascular outcome. Management of HTN in AS has historically been associated with prudence and concerns, mainly related to drug-induced potential adverse consequences. We evaluated the cardiovascular outcomes of patients with AS and HTN undergoing to AVR Methods: A retrospective cohort study where all the patients who underwent AVR between 2019- 2024, in a 4-level center in Bogotá, Colombia. A descriptive analysis was performed. Continuous variables were expressed as mean or median with their respective measure of dispersion, standard deviation or interquartile range (ICR), the categorical variables were expressed in proportions and absolute numbers. Results: We analyzed 1043 Patients with moderate/severe AS undergoing AVR, 64.3% (671 with HTN), median age for all of 69.8 years ICR (61.7-77.4) Hypertensive patient being older (72 years p<0.0001). In the HTN group 57.8% were men, and more frequently they had diabetes and dyslipidemia comorbidities (p<0.001) as well as greater baseline renal involvement (p<0.001) comparatively with NO-HTN. In addition, hypertensive patient had better LVEF and were treated with ARA II/IECA (55,6% vs 19.4% p<0.001), beta blockers (60.4% vs 47.3% p< 0.001) and anti-calcium medication (13,1% vs 19,5% p<0.001).Table 1. Cardiovascular outcomes showed greater tendency towards worsening of renal function. There were no statistically significant differences in mortality. Conclusions: AVR is presented as a safe procedure in patients with AS and HTN in developing countries. The institutional results show a safe technique, associated with low mortality rates. Hypertensive patients had more acute kidney injury in the post-surgical period, which leads us to propose kidney protection strategies in this group.

Compact Chromatic Confocal Lens with Large Measurement Range.

Spectral confocal sensors are effective for measuring displacements. The core of the spectral confocal measurement system is a dispersive objective lens that uses optical dispersion to establish a one-to-one correspondence between the focusing position and wavelength, achieving high-resolution measurements in the longitudinal direction. Despite significant progress in dispersive objective lenses for spectral confocal sensor systems, challenges such as a limited dispersion range, high cost, and insufficient measurement accuracy persist. To expand the measurement range and improve the accuracy of the spectral confocal sensor, we designed a compact, long-axial dispersion objective lens. This lens has a simple structure that requires only six lens elements, two of which form cemented doublets. The system length is 58 mm, with a working distance of 46 ± 6 mm and a dispersion range of 12 mm within the wavelength range of 450-656 nm. The lens has an object-side numerical aperture (NA) of 0.22 and an image-side NA between 0.198 and 0.24, ensuring high light energy utilization. Finally, a spectral confocal measurement system was constructed based on the designed dispersive objective lens, and performance evaluation tests were conducted. The test results showed that the system achieved a resolution of 0.15 μm and a maximum linear error of ±0.7 μm, demonstrating high-precision measurement capabilities. The proposed lens design enables the development of more portable and cost-effective spectral confocal sensors.

A detailed simulation study on radionuclide dispersion under spent fuel road transportation conditions: Effects of vessel type and coniferous vegetation growth

Vegetation barriers are an important environmental characteristic of spent fuel road transportation accidents. Spent fuel vessels may be affected by force majeure factors during transportation, which leads to damage to spent fuel assemblies and containers and can cause radionuclides to gradually release from assemblies to vessels to the external environment. In this work, considering the growth periods of coniferous vegetation barriers and vessel type, a radionuclide dispersion model based on computational fluid dynamics (CFD) was established by adding a decay term and a pressure loss term. The simulations showed that, first, compared to the small (Type-II) vessel, the effects of fluid flow around the large vessel (Type-I) have a more significant impact on radionuclide dispersion. The backflow around the Type-I vessel causes leaked radionuclides to disperse towards the vessel, and the larger the vessel is, the more significant the rise of the leaked radionuclide plume tail will be due to the increased negative pressure gradient area. Moreover, the area contaminated exceeding the maximum allowable concentration by radioactivity for the Type-I vessel is reduced gradually with the growth of coniferous vegetation barriers due to the weakening of the backflow effect by growing vegetation. Second, compared to vegetation barriers of 15 years and 23 years, the horizontal distance exceeding the maximum allowable concentration of the leaked 131I dispersion from Type II vessels near vegetation barriers for 12 years is the longest. The older the vegetation barrier is, the shorter the horizontal dispersion range, and the shape of radionuclide dispersion gradually transforms from flat to semicircular with vegetation barrier growth, but this could cause a greater radioactive accumulation effect near the leakage point, and the maximum concentration of leaked 131I reached 0.54 kBq·m−3 for leaked radionuclides from the Type II vessel under vegetation barriers of 23 years. In addition, improvement suggestions based on the proposed method are presented, which will enable the Standards Institutes to apply the research methodologies described herein across various scenarios. Environmental ImplicationCompared to nonradioative pollutants, radioactive pollutants are intercepted by vegetation barriers and then migrate to the soil through leaves, stems, and roots, which can contaminate the surrounding environment. Considering the effects of vessel type and coniferous vegetation growth, a radionuclide dispersion model based on CFD was established. Suggestions for decontaminating radioactive pollution areas have been proposed based on the simulation results of hypothetical scenarios. The scenario applicability improvements based on the proposed model could assist relevant Standards Institutes to making improving measures.

Dispersal and connectivity modelling simulations for invertebrate larvae passing through the Strait of Gibraltar

Abstract The link between the northeastern Atlantic and Mediterranean Sea created by the Strait of Gibraltar and the adjacent Iberian and Moroccan coasts marks remarkable transition areas between distinct environments that harbour a diverse mixture of species. The area is interesting regarding marine connectivity and the transport of pelagic invertebrate larvae, crucial knowledge to manage over-exploited populations, and minimize the impacts of climate change and anthropogenic activities. Biophysical models were developed, combining oceanic and particle-tracking Lagrangian simulations with in situ zooplankton distribution data. The conditions driving the larval exchange between the sub-basins and the connectivity throughout the region were explored, using crustacean decapod larvae as biological references. The potential exchange between both sub-basins was confirmed, although specific larval traits revealed contrasting scenarios. The simulations showed that slope-dwelling and mesopelagic larvae have advantage when crossing from the Alboran into the Atlantic, in comparison with shelf-dwelling and epipelagic larvae. Transport pathways and retention areas were identified, and passive drifts were shown to increase the dispersal range of the simulations. The spatial origin of the larval release, larval duration, vertical distribution, and the interaction of larvae with the oceanic features are presented as the main factors impacting the effective larval input into the Atlantic or Mediterranean basins.

Revisiting elemental geochemistry in surface sediments of the Ulleung Basin, East/Japan Sea: Signals from ocean dumping materials

A total of 222 surface sediments were collected in the Ulleung Basin, southwestern East/Japan Sea, from the coast to the basin and analyzed for grain size, total organic carbon, biogenic silica and major and trace elements. The metal concentrations of the surface sediments were highly spatially variable, and their distributions were grouped into four types by factor analysis: waste dumping materials (Cr, Cu, Zn, Sn, Sb, and Pb); detrital materials (Al, Fe, and Cs); suboxic diagenetic materials (Mn, Mo, Co, and Ni); and anoxic diagenetic materials (Cd and U). From core samples collected near the dumping site, approximately the top 10 cm was well mixed in the 210Pbex profiles and highly enriched in the above metals related to dumping materials. The enrichment factor of Sn indicates dumping materials well, and its distribution can be used to estimate the dispersion range of the dumped material in this basin.

Assessment of the Incidence of Müllerian Anomalies in Central Illinois

Introduction: Müllerian anomalies include a spectrum of malformations resulting from the underdevelopment of the Müllerian duct during embryological development. This results in a malformed vagina, uterus or both. Complete agenesis of one or both of these structures in a subset of these cases is known as Mayer‐Rokitansky‐Küster‐Hauser (MRKH) syndrome. There are two types of Müllerian agenesis: Type I MRKH only affects the upper vagina, cervix and uterus, whereas Type II MRKH has associated malformations affecting the renal, auditory and skeletal systems. The reported prevalence is approximately 1 in 5,000 for MRKH syndrome and ~5.5 in 100 for all Müllerian anomalies; however, there is a broad range in the described incidence rates. Purpose: We hypothesized the patient population served by the Department of Ob/Gyn, Division of Reproduction, Endocrinology and Infertility (REI) at Southern Illinois University (SIU) School of Medicine has a higher incidence of Müllerian anomalies and MRKH. Our objective was to assess the incidence of these Müllerian anomalies and describe the types of anomalies that affect women in Central Illinois. Methods: All patients receiving care at SIU Ob/Gyn, Division of REI from 01/1/2010-07/31/2021 were queried using specific ICD-9 and 10 codes and further screened to verify eligibility. A retrospective review (IRB# 21-893) was then conducted on all eligible subjects and relevant health information was extracted from the electronic health record. Continuous variables were measured by central tendency (mean or median) and dispersion (standard deviation or range). Categorical variables were described using frequencies and percentages. Results: The initial query identified 282 individuals of which 81 were deemed eligible (i.e., confirmed Müllerian anomaly). The total number of unique patients who underwent an ultrasound at REI during that time of study approval was 697. Based on these data, the calculated incidence of Müllerian anomalies in the REI patient population is ~11.6% and the incidence of MRKH is 57 in 5000. Demographics included: 74 subjects were White (91.4%), two Black or African American (2.5%), one Asian (1.2%) and 4 declined to report their race or identified as more than one race (4.9%); two subjects were of Hispanic ethnicity (2.5%). Mean ages at menarche and diagnosis were 12.7 ± 1.7 and 27.8 ± 6.4 years, respectively. Eight subjects diagnosed with MRKH had Type I MRKH. The specific type of anomalies identified included: uterine septum (29.1%), arcuate uterus (25.3%), unicornuate uterus (19.0%), agenesis (10.1%), bicornuate uterus (6.3%), uterus didelphys (6.3%) and 3.8% had another type of anomaly. The majority of patients underwent surgery within approximately one year of diagnosis (74%). Postoperative complications were rare (~7%) and included mild constipation, urinary retention and bleeding from the incision site. Pregnancy outcomes were as follows: prior to diagnosis, 3 (30%) infants were preterm vs. 7 (70%) term and those were spontaneous conceptions; after diagnosis 4 (30%) infants were preterm vs 9 (70%) term deliveries and the most common methods of conception were spontaneous and ovulation induction; post-surgery 11 (31%) infants were born preterm vs 24 (69%) term deliveries, and the most common methods of conception were ovulation induction and in-vitro fertilization. Conclusions: From this initial investigation, we found the incidence of Müllerian anomalies in the SIU Ob/Gyn, REI population is higher than the wide range of reported values. As expected, the vast majority of these patients underwent surgical management with little or no complications. We aim to further study what factors/exposures may be impacting the development of female fetuses resulting in Müllerian anomalies.

Habitat requirements of deadwood-dependent invertebrates that occupy tree hollows.

Tree hollows support a specialised species-rich fauna. We review the habitat requirements of saproxylic (= deadwood dependent) invertebrates which occupy tree hollows. We focus on studies quantifying relationships between species occurrence patterns and characteristics of tree hollows, hollow trees, and the surrounding landscape. We also explore the processes influencing species occurrence patterns by reviewing studies on the spatio-temporal dynamics of populations, including their dispersal and genetic structure. Our literature search in the database Scopus identified 52 relevant publications, all of which were studies from Europe. The dominant taxonomic group studied was beetles. Invertebrates in hollow trees were often more likely to be recorded in trees with characteristics reflecting a large amount of resources or a stable and warm microclimate, such as a large diameter, large amounts of wood mould (= loose material accumulated in the hollows mainly consisting of decaying wood), a high level of sun exposure, and with entrance holes that are large and either at a low or high height, and in dry hollows, with entrances not directed upwards. A stable microclimate is probably a key factor why some species of saproxylic invertebrates are confined to tree hollows. Other factors that are different in comparison to downed dead wood is the fact that hollows at a given height from the ground provide shelter from ground-living predators, that hollows persist for longer, and that the content of nutrients might be enhanced by the accumulation of dead leaves, insect frass, and remains from dead insects. Several studies have identified a positive relationship between species occupancy per tree and the amount of habitat in the surrounding landscape, with a variation in the spatial scale at which characteristics of the surrounding landscape had the strongest effect over spatial scales from 200 to 3000 m. We found empirical support for the extinction threshold hypothesis, which predicts that the frequency of species presence per tree is greater if a certain number of trees are aggregated into a few large clusters of hollow trees rather than distributed among many small clusters. Observed thresholds in species occurrence patterns can be explained by colonisation-extinction dynamics, with species occupancy per tree influenced by variation in rates of immigration. Consistent with this assumption, field studies suggest that dispersal rate and range can be low for invertebrates occupying tree hollows, although higher in a warmer climate. For one species in which population dynamics has been studied over 25 years (Osmoderma eremita), the observed population dynamics have characteristics of a "habitat-tracking metapopulation", as local extinctions from trees occur possibly because those trees become unsuitable as well as due to stochastic processes in small populations. The persistence of invertebrate fauna confined to tree hollows may be improved by prolonging the standing life of existing hollow trees. It is also important to recruit new generations of hollow trees, preferably close to existing larger groups of hollow trees. Thus, the spatio-temporal dynamics of hollow trees is crucial for the invertebrate fauna that rely upon them.

Identification of the Campanian Ignimbrite in the Dead Sea and consequent time-transgressive hydroclimatic shifts in the Eastern Mediterranean.

Robust chronologies and time equivalent tephra markers are essential to better understand spatial palaeoenvironmental response to past abrupt climatic changes. Identification of well-dated and widely dispersed volcanic ash by tephra and cryptotephra (microscopic volcanic ash) provides time synchronous tie-points and strongly reduces chronological uncertainties. Here, we present the major, minor and trace element analyses of cryptotephra shards in the Dead Sea Deep Drilling sedimentary record (DSDDP 5017-1A) matching the Campanian Ignimbrite (CI). This geochemical identification expands the known dispersal range of the CI to the southeastern Mediterranean, over 2300km from the volcanic source. Due to the CI eruption occurring near-synchronous with North Atlantic ice surge of Heinrich Event 4 (HE4), this tephra provides insights into regional responses to large-scale climatic change in the Mediterranean. In the Dead Sea, the CI layer is associated with wetter climatic conditions. This contrasts with the contemporaneous occurrence of the CI deposition and dry conditions in the central and eastern Mediterranean suggesting a possible climate time-transgressive expansion of HE4. Our finding underscores the temporal and spatial complexity of regional climate responses and emphasises the importance of tephra as a time marker for studying large-scale climatic changes verses regional variations.

Wind-driven post-bloom dispersion of Microcystis in a large shallow eutrophic lake: A case study in Lake Taihu

To clarify the wind-driven post-bloom dispersion range of Microcystis, which originally clustered on the water surface, an Individual-Based Model (IBM) of Microcystis movement considering the combined effects of wind and light was developed based on actual hydrodynamic data and Microcystis biomass. After calibrating the effects of hydrodynamics and light, 66 cases of short-term (within a week) post-bloom with satellite images from 2011 to 2017 were simulated. The results showed that there were three short-term post-bloom types: vertical reduction (VR), horizontal reduction (HR) and mixed reduction (MR). For VR type, the cyanobacterial bloom reduction rate was rapid (>160 km2/day), but the dispersion range of Microcystis was limited (<2 km/day), and a larger bloom area was likely to form in the original location when wind speed decreased. For HR type, the cyanobacterial bloom reduction rate was slow (<10 km2/day), but Microcystis exhibited a broad dispersion range (>4 km/day), often leading to smaller, thicker, and longer-lasting cyanobacterial blooms downwind, albeit with a lower probability of occurrence. The characteristics of MR lay between the two aforementioned types.

Off-Axis Co-Optical Path Large-Range Line Scanning Chromatic Confocal Sensor

This article proposes a line scanning chromatic confocal sensor to solve the problem of limited chromatic confocal measurement due to the small measurement range and low measurement efficiency in the industrial inspection process. To obtain an extensive dispersion range, the advantages of a simple single-axis structure are combined with the advantages of a large luminous flux of a biaxial structure. Considering large-scale measurement, our sensor uses off-axis rays to limit the illumination path and imaging path to the same optical path structure. At the same time, the field of view is expanded, and a symmetrical structure is adopted to provide a compact optical path and improve space utilization. The simulation and physical system test results shows that the sensor scanning line length is 12.5 mm, and the axial measurement range in the 450 nm to 750 nm band is better than 20 mm. The axial resolution of the detector is ±1 µm combined with the subpixel centroid extraction data processing method, and the maximum allowable tilt angle for specular reflection samples is ±7°. The thicknesses of transparent standard flat glass and the wet collagen membrane are measured. The maximum average error is 1.3 µm, and the relative error is within 0.7%. The constructed sensor is of great significance for rapidly measuring the three-dimensional profile, flatness, and thickness in the fields of transparent biological samples, optics, micromechanics, and semiconductors.

MaNGA DynPop – V. The dark-matter fraction versus stellar velocity dispersion relation and stellar initial mass function variations in galaxies: dynamical models and full spectrum fitting of integral-field spectroscopy

ABSTRACT Using the final Mapping Nearby Galaxies at Apache Point Observatory sample of 10K galaxies, we investigate the dark matter (DM) fraction fDM within one half-light radius Re for about 6K galaxies with good kinematics spanning a wide range of morphologies and stellar velocity dispersion. We employ two techniques to estimate fDM: (i) Jeans anisotropic modelling (JAM), which performs DM decomposition based on stellar kinematics and (ii) comparing the total dynamical mass-to-light ratios (M/L)JAM and (M*/L)SPS from stellar population synthesis (SPS). We find that both methods consistently show a significant trend of increasing fDM with decreasing σe and low fDM at larger σe. For 235 early-type galaxies with the best models, we explore the variation of stellar initial mass function (IMF) by comparing the stellar mass-to-light ratios from JAM and SPS. We confirm that the stellar mass excess factor αIMF increases with σe, consistent with previous studies that reported a transition from Chabrier-like to Salpeter IMF among galaxies. We show that the αIMF trend cannot be driven by M*/L or IMF gradients as it persists when allowing for radial gradients in our model. We find no evidence for the total M/L increasing toward the centre. We detect weak positive correlations between αIMF and age, but no correlations with metallicity. We stack galaxy spectra according to their αIMF to search for differences in IMF-sensitive spectral features (e.g. the $\rm Na_{\rm I}$ doublet). We only find marginal evidence for such differences, which casts doubt on the validity of one or both methods to measure the IMF.

Assessing Dandelion Seed Dispersal and Environmental Impact: A Comprehensive Study

The study investigates the dispersal range of dandelion seeds influenced by wind, considering fruit ripening and invasive species’ impact. CFD fluid dynamics simulation using Ansys Fluent software, integrating Navier-Stokes equations and turbulence theory, analyzes seed motion characteristics and dispersion dynamics in an ideal fluid domain. Parameters like air density and viscosity, representing various seasons, were adjusted in diffusion range across different time scales.We obtained the approximate distribution of dandelion seeds across different seasons and climates, finding larger dispersal areas in arid climates due to stronger winds. In comparison, temperate climates exhibit smaller areas due to gentler winds. To assess the impact of an alien plant on the local environment, we constructed judgment criteria using the Analytical Hierarchy Process (AHP). Through pair-wise comparisons, we calculated weightings for criteria encompassing environmental interference, economic influence, and effects on human health. By assigning ratings to each criterion based on logical reasoning and scientific evidence, we quantified the plant’s impact, yielding a score of 5.74 out of 10 for dandelion, indicating an overall positive effect in the community. Sensitivity testing confirmed the robustness of our model.