Edge Effects Research Articles

Measuring Land Preservation Success: Applying Fragstats to Preserved Farmland in Lancaster County, Pennsylvania

Edge effects are traditionally discussed in biogeography and ecosystem protection. Yet preserved farmland can also experience challenging pressures at its perimeter, such as increased development pressure and conflicts between farms and nonfarm neighbors. Academic assessments of the most common farmland preservation goal—large, contiguous blocks—have focused on the area and connectivity of preserved parcels and largely overlooked the block or shape component, which relates most strongly to these types of pressures. This study fills that gap, applying the edge-effects concept to preserved farmland for the first time and tracking the shape of preserved farmland patches in Lancaster County, Pennsylvania, a leading agricultural county in the United States. The study uses the spatial pattern analysis program Fragstats to examine preserved farmland patch size, shape, and area in Lancaster County between 2000 and 2023. Results show that although land preservation organizations in Lancaster County had success at increasing the area and contiguity of preserved land, the perimeter of farmland patches increased even more significantly, even when accounting for differences in area. Farmland patches became increasingly irregular over the study period, with meandering shapes that maximize edge. The outcome suggests that tracking edge separately from area and contiguity is important because success in one does not mean success in the others. Information on edge and shape can help land preservation organizations prioritize parcels that reduce the edge effects that make it more expensive to purchase easements and more challenging for farmers to keep farming.

Thin corridors limit wildlife: Variance of tropical carnivore distribution and habitat use in a critical rainforest corridor

AbstractMadagascar is acclaimed for its floral and faunal endemism and biodiversity. Among the island nation's most emblematic fauna are its native mammalian carnivores; they are members of the threatened and endemic Eupleridae family. The Corridor of Marojejy, Anjanaharibe‐Sud Special Reserve, Tsaratanana (COMATSA) is a newly protected corridor system that faces deforestation and lacks detailed assessments of its native carnivore community. We deployed 44 motion‐activated trail cameras to identify which terrestrial carnivores are found within the rainforest corridor landscape of COMATSA‐Sud and Marojejy National Park, and to examine carnivore occupancy, relative activity and the impacts of habitat edge. Our sampling array operated from October 20, 2021, to February 10, 2022 (113 days) and confirmed the presence of four species in Eupleridae: Cryptoprocta ferox, Fossa fossana, Galidia elegans, and Galidictis fasciata, as well as a non‐native carnivore species: Canis familiaris. We show that carnivore occurrences significantly increase with distance to forest edges. We discuss the negative impacts of forest loss on native carnivores and highlight the threats posed by the non‐native carnivore C. familiaris. Our findings spotlight faunal detections across the corridor and indicate that fewer native carnivores are found in the corridor compared to nearby protected areas, suggesting that deforestation correlates with a skewed distribution of carnivore detections. Based on our data, we provide management recommendations for the protection of the forest corridor and its endemic faunal community.

Finite Element Analysis of Electrostatic Coupling in LISA Pathfinder Inertial Sensors

In the LISA Pathfinder (LPF) mission, electrostatic noise can reach the femto-Newtonian level despite the fact that the LPF’s sensors are equipped with potential shielding. Most of the existing simulation studies focus on the electrostatic edge effect and related fields, while the simulation study of the patch effect is neglected. For that reason, this paper analyzes the basic principle of electrostatic noise and constructs a simulation model for studying the coupling effects of a TM’s residual charge and stray bias voltage. The patch effect and other perturbation factors are simulated by the simulation model with finite element operation, focusing on the suppression effect of the protective ring on the edge effect, the realization of the patch effect in the simulation model, and the possible influence. The results show that electrode area and the spacing between the electrode and the TM together limit the suppression effect of the protective ring on the edge effect. The spatial and temporal variations of the patch effect significantly affect the distributed electric field between the electrodes and the TM, as well as the charge distribution density of the TM. In the worst-case scenario of LPF electrostatic input parameters, the electrostatic noise is about 1.03 × 10−15 m/s2/√Hz at 1 mHz, which is about 6% different from the expected performance estimate. Finally, considering the limitations of multiple environmental factors on the inertial sensors, the present model will be useful to explore the interactive effects of multi-field coupling and to further investigate the impact of low-energy electron charging on the performance of the inertial sensors.

Fully protected marine areas linked to reduced home ranges of fishes

AbstractHome range size is a fundamental trait that can affect the probability of fish being harvested and, at the same time, may be affected by fishing. The relationship between home range size and fishing will impact the effectiveness of fully protected areas (FPAs), as it will influence the number of fish moving into fished areas, affecting both spillover and edge effects. One hypothesis is that individuals within FPAs will present reduced home range size relative to individuals in fished areas. This pattern can be driven by demographic selection (e.g. fishing of individuals with large home ranges leaving the FPAs), improved habitat requiring less foraging movements, or behavioural changes associated with reduced fishing threats. To test the relationship between home range size and protection, we compiled 1143 individual‐level home range sizes based on acoustic tracking, covering 17 species from 11 FPAs in 7 countries, with information on distance from FPA borders. A dichotomic analysis (in/out of FPAs) did not support a significant change in the home range size between FPAs and fished areas. However, continuous analysis across the FPA borders demonstrated reduced home range size within the FPAs. We did not find an effect of FPA age or size on this pattern. While we cannot pinpoint the underlying mechanism for the pattern revealed, we suggest behavioural changes as the main driver for reduced home range within FPAs. This mechanism will lead to more resident populations within FPAs, reducing fishing mortality within FPAs yet limiting spillover benefits to adjacent fisheries.

Pervasive impacts of railway edge effects on edaphic parameters and vegetation distribution patterns

Addressing the ecological impacts of transport corridors while planning any transport network is paramount for a better of understanding ecological processes, biodiversity distribution, and ecosystem resilience. Here, we evaluated the impacts of railway edges on edaphic parameters, plant diversity, and composition in the northwestern Himalaya as a function of perpendicular distance from the railway track. In 2014 and 2017, we sampled vegetation plots across 31 sites distributed along 119 km of the Kashmir railway to test the effect of railway tracks on edaphic and vegetative parameters in short-term periods. T-shaped plots were laid comprising four sub-plots, one parallel to the track and the other three perpendiculars to it. We adopted the Mountain Invasion Research Network road survey methodology for data collection. We found (i) an increasing trend in all soil parameters (electrical conductivity, salinity, organic carbon, available nitrogen, and available phosphorus), except pH, as the distance from the railway track increased; (ii) significant railway edge effects on the importance value index of plant growth forms, life span, nativity and taxonomic group across space (distance of plots from the track) and time (2014–2017); and (iii) a significant spatiotemporal railway edge effects on plant species composition. Our results are pioneering in showing that railway tracks crossing through different ecosystems alter the edaphic conditions, resulting in direct and indirect edge effects on key abiotic and biotic factors, which in turn impact the vegetation of the surrounding natural habitats on both sides of the railway track. Our study contributes toward a better understanding of the role of anthropogenic edges like railways on edaphic parameters and vegetation distribution.

Influence of seasonality and edge effect on seagrass-associated macrobenthic communities: A case study from the Andaman Islands, India

Seagrass seasonality and community interactions within a meadow are local-scale ecological measures that inform management, especially in the wake of climate change. We investigated the collective influence of two ecological processes- seagrass seasonality, and edge effect, on the macrobenthic communities in the Andaman Islands, India. Thalassia hemprichii formed two mono-species intertidal meadows, while Enhalus acoroides dominated the mixed-species meadow. The study was carried out across winter (January), summer (April), and monsoon (August) in 2021 using quadrat sampling (0.5 ×0.5 m), where we surveyed the edges, center, and unvegetated micro-habitats within a meadow. Our findings suggest site-specific seasonality trends for T. hemprichii, as seasonality was governed more by the local environment than species. However, seagrass growth was the lowest in summer for both the investigated meadows. Further, we report a differential influence of seagrass seasonality on macrofaunal densities. Infaunal densities were the highest in low seagrass growth (summer), while epifaunal densities positively correlated with seagrass meadow attributes. For both investigated sites, the highest epifaunal densities were observed in winters [Site 1 = 116.8 ± 27.5 ind./m2; Site 2 = 187.8 ± 14.3 ind./m2). Lastly, we report no influence of edge effect on infauna but a little on epifauna, where for the latter, trends were site, season, and group-specific. Epifaunal holothuroids were the only group with a consistent negative edge across sites and seasons, and densities were concentrated in center > edge > unvegetated regions. In conclusion, we suggest that seagrass seasonality is a product of the local environment rather than the species type. Furthermore, seagrass seasonality substantially influenced macrofauna more than the edge effect. This study is the first attempt from the Indian waters to collectively study community responses towards seagrass seasonality and edge effect, filling a critical ecological gap in seagrass research and management in India.

EDGE EFFECTS ON THE ABUNDANCE OF THE CRAB Ucides cordatus (DECAPODA: OCYPODIDAE) IN A NEOTROPICAL MANGROVE

Mangroves are among the most productive and biologically important ecosystems in the world and are currently undergoing extensive habitat loss and fragmentation. Such habitat loss and fragmentation result in the creation of edges, which can cause edge effects on the remaining habitat, resulting in changes in abiotic conditions, alterations in ecosystem functioning, and loss of biodiversity. The crab Ucides cordatus (Linnaeus, 1763), locally known as “caranguejo-uçá,” is a species of great economic and ecological importance in these environments. This species is also considered an important indicator of environmental quality, being sensitive to various pollutants. Therefore, we evaluated how anthropogenic edges affect the U. cordatus population in a mangrove area and compared these patterns to those observed at natural edges. We found a positive effect of edge creation on crab abundance for the total number of burrows and the number of open burrows, but no effect on the number of closed burrows. Conversely, we detected a negative effect of natural edges on the quantity of closed burrows. Our findings suggest that anthropogenic edges may alter crab abundances, becoming the preferred habitat for young crabs. However, we emphasize that the interior of the mangrove is also crucial for species maintenance, especially for adult crabs and juveniles during molting.

Edge-affected droplet dynamic and subsequent frost growth characteristics for horizontal cold plate under different humidity levels

Frosting widely exists in engineering applications and mostly has negative impacts. To better avoid or utilize frosting, more micro and systematic investigations into the frosting mechanisms are necessary. In this study, the combined effect of humidity and plate edge on droplet dynamic and the subsequent frost growth characteristics of a horizontal cold plate is experimentally investigated. The results show that the difference in the durations of droplet condensation stage between edge-affected and unaffected regions is little, and both decrease from around 480 to 43 s when relative humidity (RH) increases from 30% to 80%. In contrast, the difference in the durations of droplet freezing stage between edge-affected and unaffected regions is significant. The former is around 9 s at all humidity levels, while the latter decreases from around 100 s to 40 s when RH increases from 30% to 80%. Meanwhile, the average equivalent droplet diameters in the edge-affected region are 87.3 × 10−3–122.1 × 10−3 mm, which are 31.0 × 10−3–45.5 × 10−3 mm larger than in the unaffected region. The frost layer surface roughness at 80% RH is smaller than others due to the frost crystal reverse melting. This paper can help better understand the frosting mechanism from a microscopic scale and guide the accurate prediction of frost formation.

Numerical study on heat transfer and pressure performance of different suspension nozzles

The drying process of the lithium battery pole pieces makes extensive use of the suspension nozzle. It is of great significance to study the heat transfer and pressure steady-state characteristics of the suspension nozzle and to select the appropriate nozzle structure for the production of pole pieces. Based on the SSTk-ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{SST }}k - \\omega$$\\end{document} turbulence model, this article numerically simulates the impact jet process of suspension nozzles with slits, injection holes, and effusion holes. There is a qualitative and quantitative analysis of the distribution of their velocity field, temperature field, local Nusselt number, average Nusselt number, local pressure coefficient, and average pressure coefficient, and the comprehensive performance index of the nozzle is proposed. The results show that when the weight factor of heat transfer performance α is less than 21.61% and the weight factor of pressure performance β is more than 78.39%, the comprehensive performance of the traditional suspension nozzle with double slits is the best. As the α is increasing, the β is decreasing. The comprehensive performance of the suspension nozzle with effusion holes is the best. The turbulent intermittence, interaction between neighbouring jets, and edge effects affect the heat transfer and pressure uniformity of the suspension nozzle.

Model modification and influence of edge effect on effective area of giant electro-rheological polishing using plate electrodes

Abstract Giant electro-rheological polishing (GPRP) is recognized as an innovative ultra-precision machining technology with significant potential. However, the pronounced edge effect within the GPRP's polishing gap can introduce errors in calculating the effective area and designing the electrode structure. This, in turn, may lead to under-polishing and an increased risk of insulation breakdown. In this study, COMSOL was employed to investigate the electric field distribution characteristics within the polishing gap. This exploration aimed to refine the calculation model of the effective area, optimize the plate electrodes' structure and size, and diminish the likelihood of insulation breakdown. Through systematic finite element simulations, the impact of polishing voltage, inter-electrode gap, and plate length on the edge effect was thoroughly analyzed to ascertain its influence range. The simulation findings revealed that, while maintaining a constant inter-electrode gap for the tool electrode, variations in the polishing gap, polishing voltage, and plate length within specific ranges resulted in an edge effect influence range of approximately 1 mm. Moreover, when the machining gap, polishing voltage, and plate length remained unchanged, the edge effect influence range increased proportionally with the electrode gap within a specific range, approximately equivalent to the size of the electrode gap. Experimental validation of the giant electro-rheological effect confirmed the existence and influence range of the edge effect, aligning with the finite element simulation results. Ultimately, modifications to the calculation model of the effective area were proposed, along with a solution to optimize the electrode size and structure, with the objective of reducing the probability of insulation breakdown. In practical applications, this work can provide a valuable reference for electrode structure design, insulation breakdown improvement and parameter selection.

Correlation between microstructural inhomogeneity and architectural design in additively manufactured NiTi shape memory alloys

ABSTRACT Additively manufactured Nitinol (NiTi) architectured materials, designed with unit cell architectures, hold promise for customisable applications. However, the common assumption of homogeneity in modeling and additive manufacturing of these architectured materials needs further investigation because geometric-dependent melt pool behaviour results in inhomogeneous microstructure and thermomechanical properties. This study shows that property inhomogeneity at the mesoscale is one reason for pseudo-linear response and partial superelasticity of the fabricated NiTi body-centered cubic (BCC) architectured materials. We modeled using a phenomenological constitutive relation and additively manufactured NiTi architectured materials with varying relative densities. These fabricated samples showed distinct microstructural textures and compositions that affected their local recoverability. The edge effects and laser turn regions were identified as the causes underlying the observed microstructural inhomogeneity. The dimensionless Fourier number is used to describe the transition of printing modes. This study provides valuable information on rigorous experimental/computational consistency in future work.

Influence of substrate edge chamfer geometric features on the edge effect of spin-coating film

Abstract The spin-coating method is a widely employed technique for thin film fabrication. However, edge effects can adversely affect the quality and utility of the films produced. This study investigates the influence of chamfered edges on the substrate during the spin-coating process on edge effects. Both experimental and simulation results indicate that smaller chamfer angles contribute to reducing the width of edge effects. Conversely, the width of the chamfer has a relatively minor impact on the extent of edge effects.

Revealing Mode Formation in Quasi-Bound States in the Continuum Metasurfaces via Near-Field Optical Microscopy.

Photonic metasurfaces offer exceptional control over light at the nanoscale, facilitating applications spanning from biosensing, and nonlinear optics to photocatalysis. Many metasurfaces, especially resonant ones, rely on periodicity for the collective mode to form, which makes them subject to the influences of finite size effects, defects, and edge effects, which have considerable negative impact at the application level. These aspects are especially important for quasi-bound state in the continuum (BIC) metasurfaces, for which the collective mode is highly sensitive to perturbations due to high-quality factors and strong near-field enhancement. Here, the mode formation in quasi-BIC metasurfaces on the individual resonator level using scattering scanning near-field optical microscopy (s-SNOM) in combination with a new image processing technique, is quantitatively investigated. It is found that the quasi-BIC mode is formed at a minimum size of 10×10-unit cells much smaller than expected from far-field measurements. Furthermore, it is shown that the coupling direction of the resonators, defects and edge states have pronounced influence on the quasi-BIC mode. This study serves as a link between the far-field and near-field responses of metasurfaces, offering crucial insights for optimizing spatial footprint and active area, holding promise for augmenting applications such as catalysis and biospectroscopy.

The analysis of Yunnan Dayao basin effect based on microtremor test and numerical simulation

AbstractMicrotremor tests and finite element numerical simulations were used to analyze the seismic ground motion effects of the Yunnan Dayao sedimentary basin. The results of the microtremor relative to the reference point spectral ratio (HS/HR) method showed that the spectral ratio curves of each observation point in Dayao basin show multipeak characteristics, indicating that the site consists of different soil layers; the predominant frequencies of each observation point mainly are 6~9 Hz in the basin and there are lots of differences in the predominant frequencies of different observation points, which indicate that the site stiffness of each observation point is different; the differences of spectral ratios between the east–west directions (EW) and the north–south directions (NS) reveal the site's anisotropy. The amplification coefficient characteristics of each observation point in the basin obtained by numerical simulation show that the predominant frequency is 6 ~ 9 Hz; the amplification coefficients of each observation point are different; the edge effect and the focusing effect amplify the seismic ground motion in the basin; the different amplification coefficients of the two sub‐basins reflect the significant effect of the basin soil layers' differences on the seismic ground motion, the site is softer and amplification coefficients are larger; the slope degree of basin edges significantly affects the seismic ground motion near the basins edge, the amplification coefficients of the slope steeper and amplification coefficients larger. This study demonstrates that the microtremor test spectral ratio (HS/HR) method has good reliability applied to the analysis of basin effect and combining the finite element numerical simulation method is more effective in revealing the basin effect mechanism.

Influence of the edge effect of the solenoid magnetic field on the discharge process of magnetron sputtering in long and narrow chambers

The fourth-generation light source or future particle accelerators have compact vacuum systems, resulting in a small flow conductance of the beam chamber. The development of NEG (Non-Evaporable Getters) films technology with distributed pumping is a good solution. This technology can obtain a pressure distribution with a small pressure gradient and an ultra-high vacuum of 10-8 Pa inside the vacuum chambers. In the magnetron sputtering process for NEG coating, the inhomogeneity of the magnetic field at the edge of the solenoid is a key parameter for affecting the stability of the magnetron sputtering discharge process. The influence mechanism of the edge magnetic field on the plasma discharge process and discharge uniformity was studied to optimize the coating parameters, which is very important. The Particle-In-Cell/Monte Carlo Collision (PIC/MCC) method was employed to simulate plasma discharge in a narrow vacuum chamber under various edge magnetic field conditions. The potential distribution, charged particle density distribution, and particle density distribution on the target were acquired for four sets of discharge parameters, followed by data processing and analysis. The electric field distribution during the discharge process is closely linked to the non-uniformity of the magnetic field at the solenoid's edge. The smaller Br (the radial component of the magnetic field) component of the magnetic field, the more uniform distribution of Ar+ on the target surface, and the smaller the difference along the length of the vacuum chamber. A smaller radial component (Br) of the magnetic field results in a more uniform distribution of Ar+ on the target surface and reduces variations in film thickness along the length of the vacuum chamber. This is attributed to the small distance between the inner wall of the vacuum chamber and the cathode target. The change in the edge magnetic field will result in the rapid migration of electrons to the inner wall of the vacuum chamber and insufficient collision with the discharge gas, making it challenging to sustain the discharge process. Moreover, fluctuations in the edge magnetic field of the solenoid induce gradient drift and curvature drift in charged particles, resulting in rapid electron loss and alterations in the density and potential distribution of charged particles at the ends of the vacuum chamber, ultimately leading to discharge instability. The research results show the importance of the edge magnetic field effect on the magnetron sputtering coating of the slender vacuum chambers, which provides an important reference for the segmented coating process of similar vacuum chambers in future accelerators.

Chiral silicene nanoribbons under transverse and vertical electric fields: Role of edge states

In this paper, we study the edge effects on the electronic transmission of chiral silicene nanoribbons (CSiNRs) using the tight binding method and Green’s function approach. The investigation covers SiNRs of different chiralities and widths under the influence of transverse and vertical electric fields. The results show significant variations in the electronic properties of SiNRs based on these parameters. The study further explores the role of edge states in the electronic properties of CSiNRs, a topic of recent interest due to potential applications for efficient transport of electrical or optical signals. The results contribute to the understanding of the anisotropic nature of electronic transport in silicene ribbons and open new avenues for the exploration of silicene-based electronic and optoelectronic devices.

Devising an edge effect compensation procedure to eliminate structural distortions during frequency filtering

The object of this study is the process of filtering astronomical frames that contain images of potential objects in the Solar System. To recognize the image of each such object in contrast with the background of the frame, it is necessary to carry out frequency filtering of the image. Any frequency filtering using various image filters is aimed at reducing the dynamic range of the background substrate. Also, frequency filtering leads to an increase in the signal-to-noise ratio of the entire image or its fragments, depending on the configuration. However, the identified problem area of each image during frequency filtering is the distortion of the structure of its edges. Therefore, to solve this problem, an edge effect compensation procedure has been proposed to eliminate structural distortions during frequency filtering. Complementing the image with borders on all sides and the augmented extended image made it possible to introduce a formal connection between the pixel values of the extended image fragment and the pixel values of the extended original image. Testing was carried out using a high-pass Gaussian filter. The use of the devised edge effect compensation procedure made it possible to remove distortion of the structure of the image edges. The devised edge effect compensation procedure was tested in practice within the CoLiTec project. It was implemented during the in-frame processing stage of the Lemur software. The study showed that the use of the devised edge effect compensation procedure makes it possible to remove image artifacts compared to conventional filtering without taking into account the edge effect. Also, owing to edge effect compensation, structural image distortions were eliminated, and the signal-to-noise ratio was increased by 7–10 times

Edge effect during microwave plasma chemical vapor deposition diamond-film: Multiphysics simulation and experimental verification

Edge effect during microwave plasma chemical vapor deposition diamond-film: Multiphysics simulation and experimental verification

Investigating Transmission Coefficients of AB-Stacked Bilayer Graphene Nanoribbons with Varied Edge Configurations

In this study, the transmission coefficients of AB-stacked bilayer graphene nanoribbons (AB-BGNRs) with different edge configurations, specifically zigzag and armchair edges, are comprehensively investigated. These coefficients are modeled and simulated using the tight-binding (TB) model and non-equilibrium Green’s function (NEGF) formalism. The impact of edge structures on the electronic properties of AB-BGNRs is highlighted, providing insights into their potential applications in nanoelectronics devices. Significant variations between zigzag and armchair-edged bilayer graphene nanoribbons (BGNRs) are demonstrated, emphasizing the importance of edge configuration in device performance. This study contributes to the fundamental understanding of edge effects in bilayer graphene and paves the way for the design of more efficient graphene-based electronic devices.

Seasonal activity of plum curculio (Coleoptera: Curculionidae) in small Southeastern peach orchards.

Plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae), is a key pest in Southeastern peach production by infesting fruit and decreasing yield. In Northeastern apples, plum curculio was found to have an "edge effect," where more plum curculio are present next to a forested border than in the center of an orchard, and their propensity to fly or walk depended on air temperature. We conducted field studies over 3 seasons (2019-2021) to investigate whether plum curculio in small Southeastern peach plots exhibits the edge effect and to determine its primary mode of movement (flying or walking). Our results revealed that plum curculio did not exhibit the edge effect in Southeastern peaches. Thus, unlike Northeastern apples where plum curculio exhibits the edge effect, the reduced-input application program where insecticide sprays mainly target a few perimeter-row trees instead of the whole orchard for plum curculio management is not recommended for Southeastern peaches. Additionally, we observed that plum curculio in Southeastern peaches did not exhibit a primary mode of movement, and in most of the sampling weeks, the numbers of flying and walking plum curculio were not significantly correlated in the field. These results emphasize that using plum curculio sampling tools that only capture flying or walking plum curculio is not ideal for monitoring plum curculio activity in the Southeast. Overall, our findings indicate that plum curculio in Southeastern small peach plots and Northeastern apples does not exhibit the same behavior (i.e., edge effect and propensity to fly or walk).