Entire Area Research Articles

Optical and electrical properties of Ni+2 doped nanocrystalline Bi2S3 thin films prepared by chemical bath deposition method

Nickel (Ni+2) doped nanocrystalline Bi2S3 thin films are deposited on the glass substrate from the solutions containing Bismuth Nitrate, Ethylenediamine Tetraacetic acid (EDTA) and Thioacetamide at a bath deposition temperature of 318K. The optical, surface morphological and electrical properties of Ni-doped Bi2S3 thin films prepared at three different doping concentration are investigate by using ultraviolet–visible transmission spectra (UV–Vis), Scanning electron microscopy (SEM), Energy Dispersive X-ray (EDAX) and thermo-e.m.f. techniques. The optical band gap energies are found in between 2.32-2.43 eV. The SEM images show that the prepared films are continuous, dense and distributed over the entire area with good uniformity. The electrical conductivity of the films are in the order of 10-2 Ω-1 m-1 . The films are n-type as determined from the Hot Probe method. Photoconductivity studies reveal that photocurrent increases with the increase in Ni doping concentrations. Due to the absorption of photons, free electron-hole pairs (EHP) are produce.

Assessing Peri-Urbanisation and Urban Transitions between 2010 and 2020 in Ho Chi Minh City using an Urban Structure Type Approach

This paper contributes to the understanding of the recent urban development of Ho Chi Minh City, Vietnam. Previous studies have aimed at quantifying the city’s spatial growth yet have disregarded its inherent morphological and socio-economic heterogeneity. To overcome this knowledge gap, we employ an urban structure type approach for the spatially explicit quantification of urbanisation patterns for the period 2010–⁠2020, categorising 77,000 blocks across the entire administrative area of 2095 km2. The approach allows us to understand the basic underlying processes of urbanisation, both quantitatively and qualitatively, and the main growth corridors along the rural–urban gradient. By contextualizing and combining our findings within current literature and official planning reports, we discern between traditional urban growth and the contemporary new town development patterns, highlighting their driving forces and policy implications. Incremental plot-by-plot development along the northwest development corridor is observed as the principal mode of urban development, whilst bypass urbanisation is seen along both the eastern and southern development corridors. Our block-based results highlight the city’s key growth challenges and provide insights on a scale that is meaningful for official spatial and infrastructure planning, and periodic analysis and monitoring. As far as the authors are aware, this is the first time that an urban structure type approach was applied to understand the rapid urban growth dynamics of an emerging megacity in Southeast Asia.

Optimizing coffee production: Increased floral visitation and bean quality at plantation edges with wild pollinators and natural vegetation

Abstract Animal pollination is important for more than 75% of agricultural crops, including coffee, whose productivity can increase with adequate pollination. Bees, including many solitary species, are diverse pollinators, with around 85% of them considered more effective than honeybees in pollen transfer. We assessed the coffee plantation and its surrounding vegetation for solitary bee nesting throughout the coffee flowering season and measured their impact on coffee productivity. We installed collection stations with trap nests inside a coffee plantation, on the border and inside the native vegetation in a farm in Diamantina, MG, Brazil. We used 10 weekly monitored replicates at least 1 km apart. We evaluated fruiting by autogamy in relation to natural pollination and used the increase in fruit set from pollinators to calculate the farmer's monetary gain. We recorded bee visits to the exposed flowers during coffee flowering considering both on the edge and inside the coffee plantation. Ripe fruits were dried, counted and weighed. We discovered 132 solitary bee nests outside the plantation, with 54% containing coffee pollen grains, indicating coffee as an essential resource for bees even outside the crop area. More bee visits occurred at the coffee plantation's edge, resulting in increased fruit production, denser fruits, and rounder fruits in that area. Bagged flowers produced consistent seeds in all locations. The farmer could earn an extra US$1736.37 per hectare if the entire area received the same level of pollination contribution from bees as observed at the coffee border. Synthesis and applications. Our study emphasises the key role of pollinators in coffee production and their impact on fruit and seed characteristics. Bee visits were more frequent on border areas, emphasising their reliance on natural nesting sites. Bee‐mediated pollination positively affected fruit traits and self‐pollinated fruits in plantation borders had reduced mass. Solitary bee nesting was primarily observed in native vegetation, underlining its importance for bee populations. Pollen composition in nests varied with proximity to coffee plantations, indicating landscape vegetation influences pollinator foraging. These findings support optimising coffee plantation design by preserving native vegetation to increase coffee yields and conserve biodiversity.

Developing a Cloud-Based Air Quality Monitoring Platform Using Low-Cost Sensors

Conventional air quality monitoring has been traditionally carried out in a few fixed places with expensive measuring equipment. This results in sparse spatial air quality data, which do not represent the real air quality of an entire area, e.g., when hot spots are missing. To obtain air quality data with higher spatial and temporal resolution, this research focused on developing a low-cost network of cloud-based air quality measurement platforms. These platforms should be able to measure air quality parameters including particulate matter (PM10, PM2.5, PM1) as well as gases like NO, NO2, O3, and CO, air temperature, and relative humidity. These parameters were measured every second and transmitted to a cloud server every minute on average. The platform developed during this research used one main computer to read the sensor data, process it, and store it in the cloud. Three prototypes were tested in the field: two of them at a busy traffic site in Stuttgart, Marienplatz and one at a remote site, Ötisheim, where measurements were performed near busy railroad tracks. The developed platform had around 1500 € in materials costs for one Air Quality Sensor Node and proved to be robust during the measurement phase. The notion of employing a Proportional–Integral–Derivative (PID) controller for the efficient working of a dryer that is used to reduce the negative effect of meteorological parameters such as air temperature and relative humidity on the measurement results was also pursued. This is seen as one way to improve the quality of data captured by low-cost sensors.

Research on multibeam line layout based on geometric mathematical model and regression analysis

A multibeam sounding system is a system that emits acoustic pulse waves through a mechanical device to map the seafloor topography in real time. It can accurately and rapidly measure the size, shape and elevation changes of underwater targets. In this study, the mathematical model of the multibeam sounding system is proposed, and the optimized design of the survey line is carried out according to different seabed geomorphology. Firstly, relevant formulas are deduced by mathematical geometry and trigonometric functions in plane space, then a spatial right-angled coordinate system is established and the direction of the survey line is projected to the x-axis, which transforms the survey line problem in three-dimensional space into a planar type, and finally, according to the mathematical definitions, the shape of the multibeam irradiation on the sloping surface is judged to be an ellipse and the projection model is constructed. The bivariate model is constructed using regression analysis, and the line measurement that meets the requirements is determined by solving the optimal solution. The conclusion shows that the optimal solution for the angle between the direction of the survey line and the projection of the normal direction of the seabed slope on the horizontal plane is 45°, and the survey line that meets the requirements of the shortest measurement length, covering the entire sea area to be surveyed, and the overlap rate of 10-20% can be obtained.

Analysis of Regional Medical Supply and Demand Network Characteristics Based on “Patient Flow Phenomenon”: A Case Study of the Core Area of the Wuhan Metropolitan Area

Examining medical supply–demand imbalances, as revealed through patients’ cross-boundary treatment behaviors, is vital for reducing a metropolitan area’s medical supply–demand gap and furthering sustainable development goals. This study, leveraging medical supply–demand and commuting data, scrutinizes medical imbalances in the Wuhan metropolitan area core. It includes a ‘People-centered’ theory for elucidating patients’ treatment behaviors, proposes a method for constructing a regional medical supply–demand network, and explores the problem of supply–demand imbalance. The key findings include: (1) Wuhan’s central area, despite its abundance of quality medical resources, fails to adequately cover the entire metropolitan area, indicating a need for broader resource distribution. (2) The Ezhou–Huangshi–Huanggang junction shows a stark contrast to Wuhan with its limited medical services and extensive hinterland connections. Future initiatives should aim to integrate resources dispersed from Wuhan, reducing regional disparities. (3) The city’s periphery, influenced by resource distribution models and geographic distance, exhibits significant variance from central urban areas in medical supply–demand connectivity, particularly around Wuhan’s eastern administrative boundaries. Future urban planning is needed to reinforce this area’s role as a vital medical services conduit. (4) The distinguishing differences among the nine medical service communities in terms of resource recognition, service sharing, and patient mobility provide policy guidance for the allocation of medical resources.

Can The Spatial Structure of a Metropolitan Area Bring Regional Economic Benefits? — A Case Study of Melbourne

ABSTRACT The metropolitan area is a manifestation of a particular stage of urbanization. This study establishes a general development law for metropolitan areas, which consists of three stages: origin, expansion, and maturity. To better understand the economic benefits of these development strategies, we selected the Melbourne metropolitan area as a case study. By quantifying the spatial structure and visualizing the spatial layout of the Melbourne metropolitan area, the results reflect the characteristics of its development mode. On the basis of the index calculation and econometric analysis, this study then evaluates the impact of this kind of spatial structure on the economic benefits of the entire area. Our findings indicate that: 1) the population and industry in Melbourne are dispersed; 2) the current spatial structure of the Melbourne metropolitan area enhances regional economic benefits; 3) the spatial structure of the Melbourne metropolitan area has the potential to further cultivate its dominant industries, allowing the area to become a competitive regional pole in Australia; 4) the financial sector can promote local economic gains, investment, and job creation; 5) benefits from Melbourne may spill over to other regions in Victoria State, eventually forming an urban agglomeration that includes Geelong.

Evaluation of electromagnetic characteristics of 3D-printed radar absorbing structures based on three-dimensional period pattern surface

This paper aims to assess the electromagnetic (EM) characteristics of 3D-printed radar absorbing structures (RASs) based on three-dimensional period pattern surface (3D PPS) within the X-band frequency range (8.2–12.4 GHz). The assessment is validated through HFSS software, a 3D printer (Markforged, X7), and a scanning free-space measurement (SFM) system. Firstly, the analysis indicates that the EM characteristics of RASs based on 3D PPS are impacted by impedance matching in the thickness direction and the scattering of EM waves at the edges. The utilization of Onyx (Chopped carbon fiber/Nylon) reveals variations in resonance frequencies and EM wave absorption performance contingent upon the surface shape. Furthermore, significant differences in the variations of EM characteristics are observed even for RASs with the same surface shape but different materials. Secondly, the measurement results of 3D-printed RAS specimens based on PPS using Onyx exhibit similar trends to the analysis results obtained with the SFM system. Ensuring precise measurement results requires specific measurement conditions tailored to each surface shape, along with an examination of the EM characteristic distribution across the entire specimen area. This is crucial due to variations in the size, number, and range of reflected EM waves in the time domain. The analysis and measurement techniques presented in this study hold applicability in designing 3D-printed RASs that demand high EM wave absorption performance, whether under normal or oblique incident EM waves.

H2S‐Mediated Gas Therapy and HSP90 Downregulation Synergically Enhance Tumor Microwave Thermal Therapy

AbstractMicrowave thermal therapy (MWTT) is a novel clinical treatment of tumors via inducing thermal effect and anti‐tumor immune response, exhibiting advantages of deep penetration, minimal invasion, and high heat conversion efficiency. However, effective ablation is difficult to cover the entire tumor area, and heat‐shock protein 90 (HSP90) is often upregulated after ablation to generate heat tolerance of sublethal tumors and weaken the induced antitumor immune effect, resulting in a high rate of tumor recurrence and metastasis. Herein, a multifunctional nanoregulator of metal phenolic network‐coated ZnS (ZnS@Ga‐tannic acid, ZGT) is proposed to release H2S for synergically enhancing MWTT. Under the costimulation of MW radiation and acidic tumor microenvironment, ZGT can improve the MW thermal effects of tumors to promote thermal damage and release H2S to induce tumor apoptosis. The released H2S can also inhibit the production of ATP and then downregulate the expression of HSP90, strengthening the activated systemic antitumor immune response after ablation. This nanoregulator provides a new way for achieving compensation effect for MWTT. The strategy of H2S gas to downregulate HSP90 and positively regulate antitumor immune response introduces a novel direction for reducing the risk of tumor recurrence and metastasis after thermal therapy.

Spatial changes of soil structural properties and organic carbon storage of arable farmland at Umuahia, Abia State

Precision agriculture requires that spatial changes of soil structural properties and soil organic carbon (SOC) accumulation be established for effective soil management. A research was carried out to ascertain the spatial variation of soil structural properties and organic carbon accumulation of an arable farmland at Umuahia. The experiment was conducted by delineating the land into three (3) portions. Three auger and core soil samples each were randomly collected from each portion, and this gave nine (9) observational points which were georeferenced. The soil samples were prepared and analysed in a laboratory for determination of parameters. The data generated were analysed for spatial variation using a GIS software package. The highest SOC accumulation of 26.46 ton / ha was obtained at the extreme north and northwestern regions of the land, while the lowest SOC accumulation of 19.71 ton / ha was obtained at extreme southeastern region of the land. The entire central area to the north western portion of the land had lowest bulk density (BD) of 1.33 kg / m3, while the southward to the north eastern portions of the land had the highest BD of 1.37 kg / m3. The highest hydraulic conductivity of 4.75 cm / mins was observed at the south western portion. The southward and extreme north eastern portions of the land had the highest mean weight diameter (MWD) of 0.95 mm, while the lowest MWD of 0.75 mm was observed at the central areaand extended to the north western portions of the land. There were also spatial changes in the total porosity, and micro aggregate stability indices across the land area. Suitable agronomic practices need to be adopted within the various portions of the land in managing the soil.

Polyphase tectonics on Mars: Insight from the Claritas Fossae

The Claritas Fossae (CF) is an elongated system of scarps and depressions >900 km long, representing the western boundary of the Thaumasia Region to the south of the Tharsis volcanic province. Although there is general agreement on the tectonic nature of such major physiographic feature, the processes that led to its formation are still debated. This study aims to better understand the tectonic evolution of the CF by combining two methodologies: kinematic numerical modelling and structural mapping. Through kinematic numerical modelling, we reproduce the present-day long-wavelength topography (hundreds of kilometres) at CF along four across-strike topographic profiles through the activity of a crustal listric normal fault. We observe that the modelled fault reaches the base of the crust, located at 80 km of depth, without changes in its listric geometry, suggesting a rather homogeneous thick crust. The accuracy of the results is based on the calculated mean misfit between the Martian and modelled topography. In two of the four profiles, the misfit is locally relatively higher, suggesting that the normal dip-slip component alone hardly explains the entire tectonic setting. Through structural mapping, we explore the depressions and scarps that feature the entire study area. We identify four sets of lineaments with different kinematics. The angular and crosscutting relationships between the sets suggest a Riedel-type arrangement within a dextral strike-slip shear zone. Thus, we propose a tectonic evolutionary model of the CF that involves a polyphase evolution made up of a Noachian-Early Hesperian right-lateral strike-slip phase followed by a Late Hesperian-Early Amazonian transtensional reactivation characterised by a significant normal dip-slip component. Our results suggest that the tectonics on Mars were not exclusively single or long-term deformations and that multiple subsequent tectonic events may have contributed to the present-day setting.

Characterizing the Thickness Distribution of Donor and Acceptor in Organic Photovoltaics via Quasi‐Monochromatic Light Transmittance

AbstractThe performance of organic solar cells is sensitive to the film thickness and the uniformity of the donor and acceptor distribution in the photoactive layer. Especially, in the quasi‐planar heterojunction fabricated by layer‐by‐layer process, the donor and acceptor materials may be non‐homogeneously distributed across the entire photoactive layer. Visualization of the spatial distributions of donor and acceptor components sheds light on the relationship between nanostructures and device performances. Based on the distinct infrared absorption characteristics of the organic donor and acceptor, a quasi‐monochromatic light transmittance (QMLT) technique is proposed to quantify the donor and/or acceptor thickness in the photoactive layer blend across the entire device area with nanometer precision. The variation in thickness of donor and acceptor can be clearly and separately revealed. Accordingly, the impacts of spin coating techniques (such as dynamic or static dispensing, and on‐center or off‐center spin coating), as well as solvent choices, on film morphology and device performance can be correlated by the noncontact, nondestructive, and convenient QMLT method.

A Proposed Methodology for Determining the Economically Optimal Number of Sample Points for Carbon Stock Estimation in the Canadian Prairies

Soil organic carbon (SOC) sequestration assessment requires accurate and effective tools for measuring baseline SOC stocks. An emerging technique for estimating baseline SOC stocks is predictive soil mapping (PSM). A key challenge for PSM is determining sampling density requirements, specifically, determining the economically optimal number of samples for predictive soil mapping for SOC stocks. In an attempt to answer this question, data were used from 3861 soil organic carbon samples collected as part of routine agronomic soil testing from a 4702 ha farming operation in Saskatchewan, Canada. A predictive soil map was built using all the soil data to calculate the total carbon stock for the entire study area. The dataset was then subset using conditioned Latin hypercube sampling (cLHS), both conventional and stratified by slope position, to determine the total carbon stocks with the following sampling densities (points per ha): 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, and 0.8. A nonlinear error function was then fit to the data, and the optimal number of samples was determined based on the number of samples that minimized soil data costs and the value of the soil carbon stock prediction error. The stratified cLHS required fewer samples to achieve the same level of accuracy compared to conventional cLHS, and the optimal number of samples was more sensitive to carbon price than sampling costs. Overall, the optimal sampling density ranged from 0.025 to 0.075 samples per hectare.

Estimation of Geotechnical Parameters for Coal Exploration from Quasi-3D Electrical Resistivity Measurements

Geotechnical parameters are crucial for mine planning and operation at different stages of development. However, estimating these parameters requires a large number of boreholes and subsequent detailed analysis of the samples, making it a cumbersome exercise. Moreover, even after conducting these studies, it is not possible to cover the entire operational area. To address this issue, this study presents an indirect method of estimating geotechnical parameters through mathematical relations using resistivity data. The present study incorporated 2D and 3D subsurface imaging techniques for exploring coal reserves and analyzing geotechnical parameters that define subsurface soil properties. Electrical resistivity tomography (ERT) was utilized for data acquisition, employing a Dipole–dipole array with a multielectrode ABEM Terrameter LS instrument. Six parallel profiles were conducted, each 400 m in length, with an inter-electrode spacing of 10 m and a spacing of 50 m between profiles. These profiles were combined into a 3D dataset referred to as quasi-3D ERT. The inversion process for both 2D and 3D data was performed using the Res2dinv and Res3dinv programs, respectively. This study overcame the challenges of 2D resistivity sections by evaluating horizontal depth slices in the x-z plane from layers 1 to 10, reaching a depth of 81.2 m. The geotechnical parameters, including cohesion, friction angle, moisture content, and plastic index, were derived from the resistivity data. The ERT method proved to be cost-effective and efficient in determining soil properties over a large area compared with traditional laboratory analysis of borehole samples. Additionally, the variation of geotechnical parameters with resistivity values exhibited unique characteristics. The results from both the 2D and quasi-3D ERT were well correlated with the borehole data. Such studies are valuable for resource exploration and mine planning purposes.

Changing effects of energy and water on the richness distribution pattern of the Quercus genus in China.

Climate varies along geographic gradients, causing spatial variations in the effects of energy and water on species richness and the explanatory power of different climatic factors. Species of the Quercus genus are important tree species in China with high ecological and socioeconomic value. To detect whether the effects of energy and water on species richness change along climatic gradients, this study built geographically weighted regression models based on species richness and climatic data. Variation partition analysis and hierarchical partitioning analysis were used to further explore the main climatic factors shaping the richness distribution pattern of Quercus in China. The results showed that Quercus species were mainly distributed in mountainous areas of southwestern China. Both energy and water were associated with species richness, with global slopes of 0.17 and 0.14, respectively. The effects of energy and water on species richness gradually increased as energy and water in the environment decreased. The interaction between energy and water altered the effect of energy, and in arid regions, the effects of energy and water were relatively stronger. Moreover, energy explained more variation in species richness in both the entire study area (11.5%) and different climate regions (up to 19.4%). The min temperature of coldest month was the main climatic variable forming the richness distribution pattern of Quercus in China. In conclusion, cold and drought are the critical climatic factors limiting the species richness of Quercus, and climate warming will have a greater impact in arid regions. These findings are important for understanding the biogeographic characteristics of Quercus and conserving biodiversity in China.

Impacts of sustainable management on the spatial distributions of erosion susceptibility and probable sediment yield in a mixed-forested watershed

Forest management practices play multifaceted roles in enhancing the geophysical properties that affect raindrop erosion in the watershed, and consequently, sediment deposition in the reservoir. The current work attempts to integrate empirical and physically-based modeling approaches to quantify the impacts of forest conservation on erosion risk and potential sediment accumulation in the mixed-forested Ogouchi Dam watershed in Japan. The reliability of the empirical model for estimating the total erodibility coefficient (TEr), as a function of various forest properties, was evaluated by applying the mathematical expression to multiple forest conditions and comparing the values to field-measured soil erosion rates. The spatial distribution of the empirically derived values showed that about 25.8% of the Government-managed forests and 45.1% of the private forests have higher risks of raindrop splash erosion compared to natural forests. The TEr value in each small Government-divided forest land (less than 5 ha) was then corresponded to the MUSLE management practice factor (MUSLE P) input in each hydrologic response unit (HRU) in the Soil and Water Assessment Tool (SWAT) model to create a sediment yield distribution map and to predict the amounts of sediment accumulation for different management scenarios. The spatial distribution of sediment yield for the base condition showed that 20.9% of the Government-managed forests and 61.6% of the private forests have higher probable amounts of sediment yield relative to the value simulated in the natural forest. A maximum cumulative sediment reduction of about 14.4% is likely attainable upon the complete control of the Government in the entire planted forest area. Overall, this study effectively utilized the field survey datasets to develop a robust empirical model for quantifying erosion risk and was able to couple the results to a GIS-based model that predicts the amounts of sediment yield under varying environmental conditions.

The movement patterns and foraging resources of Atlantic walruses (Odobenus rosmarus rosmarus) in Franz Josef Land archipelago and connectivity with the Kara‐Barents Sea population

AbstractThe Franz Josef Land population of the Atlantic walrus (Odobenus rosmarus rosmarus) remains one of the least studied. Here, 26 walruses were tagged with satellite‐linked radio transmitters in Franz Josef Land archipelago and Victoria Island in summer‐autumn 2020 and 2021 to assess movements patterns and area utilization. In addition, 65 grab samples were taken to evaluate macrobenthic foraging resources. The mean duration of data records was 53 ± 27 days. The walruses traveled on average 29 ± 13.5 km/day with a mean speed of 1.2 ± 0.6 km/hr. The travel speed and distance were statistically different for male, female, and immature walruses. The individuals tagged on Victoria Island remained in the vicinity of the island, while walruses tagged within the Franz Josef Land archipelago moved between the islands, utilizing the entire area for foraging trips. One walrus migrated from Franz Josef Land to Novaya Zemlya in late November, providing evidence of connectivity with the Kara‐Barents Sea population. The area was characterized by high average biomass of macrobenthos. Bivalve mollusks, Hiatella arctica, were dominating macrobenthic biomass, likely being the main foraging resource for the walruses. Further observations are needed to better understand winter behaviors of Franz Josef Land walruses and possible impacts of climate change on movement patterns.

Geospatial evaluation of the agricultural suitability and land use compatibility in Europe's temperate continental climate region

Land suitability assessment is used in conjunction with geographic information systems to spatially model diverse aspects of soil functions, having the potential to facilitate a sustainable increase in agricultural production, reduce land degradation, or aid humans in adapting to climate change. Compared to the existing datasets, this study provides a new higher resolution geospatial assessment of the agricultural land suitability for several crops and land uses in the temperate continental climate across Europe. To model the land suitability we used geospatial data depicting seventeen eco-pedological indicators (e.g. soil texture, pH, porosity, temperature, precipitation, slope). To evaluate how the land is utilized, the suitability maps have been spatially cross-tabulated with a crop map. Over the entire study area, wheat and barley showed significant suitable land in the southern part, potatoes, and sugar beet exhibited the highest extent of suitable land in the northern parts, while corn and sunflower exhibited a much lower extent of suitable land. Water table depth, precipitation, temperature, terrain slope, soil porosity, SOC, and topsoil texture emerged as the limiting factors for agricultural suitability in the study area. Our results show that the suitable arable land does not have space left for the expansion of crops, however, we have identified regions with extensive cultivation of wheat and corn on unsuitable land with the potential for cultivation of more suitable crops such as barley, sunflower, sugar beet, and potato. It seems that one action that can enhance agricultural practices in the study area is to better allocate each cultivated crop across more suitable lands.

Oral Rabies Vaccination of Raccoons (Procyon lotor) across a Development Intensity Gradient in Burlington, Vermont, USA, 2015-2017.

Management of the raccoon rabies virus variant in North America is conducted primarily using oral rabies vaccination (ORV). When a sufficient proportion of the population is vaccinated (∼60%), rabies transmission can be eliminated. To date, ORV programs have successfully controlled and eliminated raccoon rabies in rural areas, but there has been less success in urban areas. We studied the proportions of rabies virus neutralizing antibodies (RVNA) in a raccoon (Procyon lotor) population during a 3-yr ORV trial in developed areas of Burlington, Vermont, US. We used a modified N-mixture model to estimate raccoon abundance, RVNA seroprevalence, and capture rates jointly to examine factors that relate to ORV success to better inform management. We found that raccoon abundance was lower in less-developed areas compared to urban centers. Raccoon RVNA seroprevalence decreased as population abundance increased; it increased as the average age of the population increased. Nontarget opossum (Didelphis virginiana) captures correlated with a decrease in raccoon RVNA seroprevalence in low-development areas, suggesting that they may be competing for baits. The target bait density across the entire study area was 150 baits/km2, but a hand baiting strategy was heavily concentrated on roads, resulting in uneven bait densities within sampling sites (0-484 baits/km2). Uneven bait distribution across the study area may explain low RVNA seroprevalence in some locations. Our results suggest that increases in bait density across the study area may improve RVNA seroprevalence and support annual ORV to account for raccoon population turnover.

Analyzing microstructural, residual stress, and mechanical characteristics in dissimilar welds of Inconel 59 and AISI 904L through double-pulsed gas metal arc welding

In this research, dissimilar welding of the nickel-based superalloy Inconel 59 and austenitic stainless steel AISI 904L steel was successfully done with double-pulsed gas metal arc welding (DP-GMAW) using the filler ERNiCrMo-13. Macroscopic analysis showed a defect-free weld with an aspect ratio of 2.4, attributed to the efficient heat delivery (0.642 kJ/mm) in DP-GMAW. The microstructure of the weld joint was examined through both optical microscopy and scanning electron microscopy. Examination of the microstructure of the weld interface exposed grain coarsening near the heat-affected zone on the AISI 904L side. In contrast, the weld fusion zone contained fine equiaxed dendrites. Microsegregation and alloying element migration across the entire weld area were assessed through energy dispersive X-ray spectroscopy point analysis and line mapping, revealing controlled microsegregation across the region. X-ray diffraction (XRD) analysis was used to ascertain the average grain size (38.41 nm) and secondary phase composition. The XRD-cosα method was used to assess the residual stress of the weld joint, revealing tensile residual stress in the weld zone and compressive residual stress in other regions. Tensile, Charpy impact, and Vickers hardness tests were conducted in the study to evaluate the strength, toughness, and hardness of a dissimilar weld. The impact of two cryogenic treatments, namely shallow and deep, on tensile and toughness characteristics was investigated in this study. The cryogenic treatments significantly enhanced the mechanical properties of weld samples compared to their as-welded condition, leading to an 11.5% increase in tensile strength and a 10% improvement in toughness.