Sampling Area Research Articles

Infestation Rates, Seasonal Abundance of Aphids and Relationships with Some Environmental Factors in Different Forest Habitats in Southwestern Türkiye

Aim of study: It was to determine the infestation rate and seasonal abundance of aphids and their relationships with some environmental factors in forests. Area of study: The study was conducted in Pinus nigra, P. brutia, Cedrus libani, Abies cilicica, Juniperus spp., Quercus spp. and Robinia pseudoacacia forests (34 sampling areas) in Isparta. Materials and methods: Systematic sampling was carried out monthly throughout April-October in 2019-2020. As aphid density and infestation rates were determined, 30 cm shoots were taken from 10 trees. The slope, aspect, elevation, forest characteristics, daily minimum, average, and maximum temperature and total precipitation were recorded. Main results: Abundance were highest in P. nigra, Quercus and Robinia pseudoacacia forests in both years. There was a significant correlation between abundance and development stages (p

Estimation of Dry Matter Yield in Mediterranean Pastures: Comparative Study between Rising Plate Meter and Grassmaster II Probe

This study evaluates two expedient electronic sensors, a rising plate meter (RPM) and a “Grassmaster II” capacitance probe (GMII), to estimate pasture dry matter (DM, in kg ha−1). The sampling process consisted of sensor measurements, followed by pasture collection and a laboratory reference analysis. In this comparative study, carried out throughout the 2023/2024 pasture growing season, a total of 288 pasture samples were collected in two phases (calibration and validation). The calibration phase (n = 144) consisted of measurements on three dates (6 December 2023, 29 February and 10 May 2024) in 48 georeferenced sampling areas of the experimental field “Eco-SPAA” (“MG” field), located at Mitra farm (Évora, Portugal). This pasture is a permanent mixture of various botanical species (grasses, legumes, and others) grazed by sheep, and is representative of biodiverse dryland pastures. The validation phase (n = 144) was carried out between December 2023 and April 2024 in 18 field tests (each with eight pasture samples), in three types of representative pastures: the same mixture for grazing (“MG” field), a commercial and annual mixture for cutting (mowing) and conservation (“MM” field), and legumes for grazing (“LG” field). The best estimation model for DM was obtained based on measurements carried out in February in the case of the GMII probe (R2 = 0.61) and December 2023 and February 2024 in the case of RPM (R2 = 0.76). The estimation decreased very significantly for both sensors based on measurements carried out in May (spring). The validation phase showed greater accuracy (less RMSE) in “MG” field tests (RMSE of 735.4 kg ha−1 with GMII and 512.3 kg ha−1 with the RPM). The results open perspectives for other works that would allow the testing, calibration, and validation of these electronic sensors in a wider range of pasture production conditions, in order to improve their accuracy as decision-making support tools in pasture management.

Modeling movements improves capture–recapture estimates for mobile species with sparse data: Polar bears (Ursus maritimus) in Viscount Melville sound

AbstractWildlife management requires estimates of demographic parameters that are difficult to obtain for mobile species at low densities. Biased parameter estimates often result from capture–recapture (CR) studies due to small sample sizes and unequal recapture probabilities, the latter of which can be caused by animal movements with respect to the sampling area. We developed a multistate CR model designed to minimize biases by including multiple data types (capture, harvest, natural mortality, and telemetry) and accounting for temporary emigration. We applied the model to data collected intensively from 2012 to 2014, and intermittently since the 1970s, for the Viscount Melville (VM) subpopulation of polar bears (Ursus maritimus) in the Canadian Arctic. The number of bears within the VM subpopulation boundary likely increased from an average of 145 (Bayesian 95% credible interval [CRI] [109, 221]) in 1989–1992 to 235 (95% CRI [148, 569]) in 2012–2014. Survival probability increased for all sex and age classes except adult females, for which estimates declined due to unknown reasons. Polar bear movements exhibited Markovian dependence with approximately 28% of the subpopulation located outside of the sampling area each spring. This contributed to inaccurate parameter estimates when using a simpler, single‐state CR model that only included capture data. Although the interpretation of demographic status was complicated by statistical uncertainty and changes in study design, our findings suggest that—as of 2014—the VM polar bear subpopulation had likely recovered from an earlier period of overharvest, was stable, and had not exhibited detectable negative effects of climate warming.

Difference in reproductive traits of two sympatric species of Stigmaphyllon (Malpighiaceae) throughout their distribution range: are they context-dependent?

Populations of widely distributed plants may experience varying climatic or ecological conditions, leading to uneven evolution of reproductive traits. However, studies on reproductive biology usually focus on just one, or rarely two, sampling areas. In this study, we performed a geographical comparative analysis of the flowering pattern, pollination biology and breeding system of Stigmaphyllon bonariense and S. jatrophifolium (Malpighiaceae) throughout their natural distribution in Argentina, classifying them as ‘northern’ or ‘southern’ according to their geographic location. For this, we selected 4 populations for S. bonariense and 3 for S. jatrophifolium to characterized the flowering peak at both the individual (IFP) and population (PFP) levels, the floral display per inflorescence, the richness of Malpighiaceae species and their pollinators, and the stigmatic and body pollen loads of the pollinators. In addition, we performed manipulative experiments to determine the breeding system. Our results showed that the duration of flowering phenology and the floral display vary between northern and southern populations of both species. These traits include flowering duration and the number of flowers at anthesis per inflorescence (floral display). In addition, the pollination context exhibited latitudinal differences in species richness, phenology, body size of oil-collecting bees, and visitation frequency. Besides, the number of co-flowering Malpighiaceae species varied among populations. However, no considerable differences were observed among populations in terms of stigmatic and body pollen load in pollinators of both species. The breeding system was invariable and consistent in both species with self-incompatibility (SI). These findings suggest that certain reproductive traits of both Stigmaphyllon species are context-dependent and would allow the species maximise reproductive success in each population. Therefore, our results demonstrate that large-scale geographical studies (i.e., several populations with different climatic conditions) and the analysis of various phenological traits are necessary to better understand the reproductive biology of plant species.

Here to stay: evaluating establishment of eastern tubenose goby Proterorhinus semipellucidus (Kessler, 1877) in the Baltic Sea with otolith microchemistry and structure

In 2020, the presence of a novel non-indigenous species, eastern tubenose goby Proterorhinus semipellucidus (Kessler, 1877), was documented in the Gulf of Finland, Baltic Sea. As tubenose goby invasion may have a comprehensive ecological impact on the local ecosystem, it has to be confirmed whether the species has established an independently reproducing population or persists through continuous invasions in this area. We examined the otolith microstructure to determine the age of specimens sampled from the southern and northern coasts of the Gulf of Finland. Additionally, otolith microchemistry analysis was carried out on the southern coast specimens. Otolith microstructure revealed the population’s age structure, showing the presence of different age classes, including younger individuals. The microchemistry analyses suggested that the specimens had hatched in brackish water salinities similar to those found in the sampling areas. This indicates local reproduction instead of introduction from the virtually freshwater Neva Bay, which is most likely the donor area of the studied populations. These data confirm the establishment of a self-sustaining reproducing population of eastern tubenose goby in the Gulf of Finland, eastern part of the brackish Baltic Sea.

The Effects of Depth and Habitats on Bycatch Distribution in Deployed Fish Traps in Bidong Archipelago, Terengganu – Peninsular Malaysia

Graphical Abstract Highlight Research 1. Fish traps at 20 m depth captured the highest species diversity, while 10 m had the most bycatch abundance. 2. Habitat type strongly influenced bycatch composition and species richness, with differences across the study stations. 3. Artisanal fish traps captured a wide range of species, indicating non-selectivity in fishing. 4. Bycatch composition varied with depth, with demersal species being predominant at greater depths. 5. The study recommends management strategies like time-release mechanisms to minimize the ecological impact of fish traps. AbstractIn many marine ecosystems, the fish population has been correlated to bycatch related activities, the most frequently fisheries activities in Malaysia, while the relative importance of other factors such as the depth of artisanal fish trap remains understudied. We investigate whether the bycatch distribution would be affected by deployment of artisanal fish trap at different depths, placed at extensively studied marine educational university station, the Bidong Island, East Coast of Peninsular Malaysia, Terengganu. The traditional artisanal fish trap with a dimension of 1.52 m x 0.92 m x 0.92 m with the wooden frame and the oval shape funnel with a diameter of 25 cm x 6 cm and 25 cm of entrance depth were used for sample collection. The results show that there are six families, six genera and seven species of fish were successfully captured with a 20 m depth captured more fish species compared to others (i.e., 10 m and 15 m depth). The findings of this study provide evidence of the relationship of fish trap depths and fish distribution in the wild. This information could be useful for fishermen for further deployment of their fish trap within the sampling areas in the future.

Shear mechanical behavior and fracturing path of red sandstone treated by joninted effect of water-fractures

Water content and primary fractures can change the mechanical characteristics of rock, making it easy to induce geological disasters. Therefore, direct shear tests of red sandstone under the action of water-fracture were carried out in this paper. The results show that shear strength of rock samples with fractures is less than that of intact rock samples. With the increase of primary fracture dip angle, shear strength and macroscopic crushing area of the rock sample increases first and then decreases with 20° as the boundary. It shows that the primary fractures weaken the shear mechanical properties and change the macroscopic failure mode. The shear performance of water-bearing rock samples is weaker than that of intact rock samples, and the weakening degree of water-saturated on shear performance of rock samples is lower than that of unsaturated water state. The fracture surfaces of rock samples are divided into 'shortest path single through type', 'longest path single through type' and 'cross path through type'. The failured rock samples are divided into 'single through type' and 'cross through type'. The research results can provide reference for geological disaster management under relevant conditions.

Rapid 3D imaging at cellular resolution for digital cytopathology with a multi-camera array scanner (MCAS)

Optical microscopy has long been the standard method for diagnosis in cytopathology. Whole slide scanners can image and digitize large sample areas automatically, but are slow, expensive and therefore not widely available. Clinical diagnosis of cytology specimens is especially challenging since these samples are both spread over large areas and thick, which requires 3D capture. Here, we introduce a new parallelized microscope for scanning thick specimens across extremely wide fields-of-view (54 × 72 mm2) at 1.2 and 0.6 μm resolutions, accompanied by machine learning software to rapidly assess these 16 gigapixel scans. This Multi-Camera Array Scanner (MCAS) comprises 48 micro-cameras closely arranged to simultaneously image different areas. By capturing 624 megapixels per snapshot, the MCAS is significantly faster than most conventional whole-slide scanners. We used this system to digitize entire cytology samples (scanning three entire slides in 3D in just several minutes) and demonstrate two machine learning techniques to assist pathologists: first, an adenocarcinoma detection model in lung specimens (0.73 recall); second, a slide-level classification model of lung smears (0.969 AUC).

Preliminary results of the monitoring of protected red wood ants in Rila Mountain, Bulgaria

This study aimed to assess the present distribution of red wood ant species and changes in their nest density over a period of eight years in the area of Rila Mt, Bulgaria. One of the sampling areas was the Parangalitza Biosphere Reserve, the nation’s second oldest protected area. The other two sites are Rila Monastery region and Samokov region. Field monitoring via transect sampling was conducted in 2014 and 2022. We marked 35 nests along 29 transects in 2014 and 76 nests along 27 transects in 2022 of the red wood ants Formica rufa Linnaeus, 1761, F. lugubris Zetterstedt, 1838, F. pratensis Retzius, 1783, and F. exsecta Nylander, 1846, the latter of which is not a member of the rufa group. The most abundant species was F. rufa, followed by F. lugubris, F. pratensis, and F. exsecta. The nest density of F. rufa and F. pratensis decreased in some of the revisited transects after 8 years, which can be explained by increased shading of their habitats. Monitoring is recommended at least every 5 years to detect trends in red wood ant populations and evaluate the effects of protection measures.

Density-profile imaging using a second harmonic dispersion interferometer configured with reflective-beam expanders.

A Second-Harmonic Dispersion Interferometer (SHDI) is assembled to measure the two-dimensional, line-integrated density profile of a pulsed-plasma jet using probe-beam diameters well beyond the 1mm diameters typically used in such instruments. An initial prototype demonstrated the technique using 7mm beam diameters, which are now increased to 35mm diameter using two types of beam expanders: an achromatic-beam expander (ABE) or a reflective-beam expander (RBE). ABEs were found to add a periodic background to the measured-phase image with a magnitude of the order of Δϕ ∼ 2π radians, compared to the background phase noise level in the system configured without beam expanders at Δϕbg ∼ 0.025 radians. Subtraction of the background phase in a sample image reduced the effect of the ABE phase offset to a level of Δϕ ∼ 0.1 radians, enhancing the quality of the density measurements. Reflective-beam expanders (RBEs) did not modify the background phase appreciably and were a significant improvement, allowing the instrument to be used for 2D (r, z) density-profile measurements of a 3cm diameter × 5cm long, pulsed-plasma jet. Variations in the timing parameters for the plasma gun, specifically the gas valve opening time and the gas-injection delay, for a constant discharge current were used to map the plasma gun's performance, indicating a nominal line-integrated electron density of Nedl ≳ 3 × 1015 cm-2 and a volumetric density of Ne ≃ 9 × 1015cm-3. The results obtained for the RBE configuration demonstrate that the 2D-SHDI platform may be scaled to even larger sample areas and a rep-rated system, with the ability to potentially provide for a reproducible, time-resolved (∼1 ns), high resolution (∼100μm) measurement of 2D plasma-density profiles.

A Dynamic Path Planning Method for UAVs Based on Improved Informed-RRT* Fused Dynamic Windows

In recent years, navigating rotor drones in complex and dynamic environments has been a significant challenge. This paper proposes an improved path planning method by integrating the enhanced Informed-RRT* algorithm with the Dynamic Window Approach (DWA) algorithm. Firstly, the probability weight function for sampling direction is dynamically adjusted based on the Euclidean distance between the start and goal points to obtain higher-quality sampling points. Secondly, the Artificial Potential Field (APF) concept is introduced during the generation of new nodes, applying the improved APF method to the elliptical sampling area to guide the direction of new node generation. This significantly reduces the number of redundant nodes, enhances the convergence speed, and improves the obstacle avoidance efficiency. Then, a polynomial fitting method is employed to optimize the path, yielding a smoother trajectory. Finally, the improved DWA algorithm is integrated. Initially, the Informed-RRT* algorithm generates an optimal path from the starting point to the goal point in the global space, which is then provided as an initial reference path to the DWA algorithm. During actual operation, the DWA algorithm dynamically adjusts control inputs based on the current position, speed, and reference path of the drone, ensuring that the drone can avoid dynamic obstacles and unknown static obstacles in real time while staying as close to the reference path as possible.

A low-cost homogenizing device for in-field and remote DNA and RNA extraction

Environmental monitoring of microorganisms is critical for the protection and enhancement of human and ecosystem health. Even though these molecular methods have overtaken traditional culture-based methods and become more accessible, these techniques still require expensive equipment and dedicated facilities to process samples which in the context of a global pandemic, remote sampling areas or low-income countries can be extremely challenging. Sample preparation and sample homogenisation are critical steps for molecular-based techniques, especially for the extraction of DNA and RNA. This study developed a low-cost, open-source, freely available 3D printed homogenizer for the processing of DNA and RNA extraction. The BoSL Beater 3D is a portable device that allows researcher to perform bead-beating steps commonly required for environmental sample extraction protocols in the field and without access to main’s power. The BoSL Beater 3D was tested on filtered wastewater samples and passive samplers exposed to wastewater over a 24-hour period and showed similar or better performance to the traditional laboratory bead beater for both the extraction of DNA and RNA. The cost of this 3D homogeniser is roughly $18 AUD ($296 AUD with the jigsaw, which is roughly 57 times cheaper than a traditional bead beater) and has the added usability of being portable and easily adaptable to any type of jigsaw. In combination to newly developed field extraction kits as well as portable PCR machines, this 3D homogeniser could provide the tool necessary to enable access to molecular testing in remote setting as well as developing countries, which may not have access to fully equipped laboratories, but also allow for timely reporting. In addition, the BoSL Beater 3D, in combination with field extraction kit, can allow more flexibility to researchers while sampling, shipping, and processing DNA and RNA samples, whilst maintaining quality of these samples.

Do Micro Finance Banks Influence The Performance Of Small Scale Business Entrepreneurs In Ijebu North Lga, Ogun State, Nigeria?

This paper contributes to the debate on the impact of Microfinance financial and non-financial services on the development of small-scale entrepreneurs. This study actually investigated the influence of Access to Microfinance Credit and Microfinance services on the development of small-scale entrepreneurs in Ijebu North Local Government Area of Ogun State, Nigeria. Survey research design using simple random sampling technique was employed to select 90 out of 175 registered small-scale entrepreneurs in Ijebu North LGA. Applying regression analysis on the primary data collected showed that a positive and significant relationship exists between Access to Microfinance credit and performance of small-scale entrepreneurs in the sampled areas. In addition, Microfinance service was also found to exert a significant influence on small-scale entrepreneurs’ performance, albeit, the correlation coefficient and the coefficient of determination were below average. This notwithstanding, the study concludes that Microfinance provision of credit; financial services, business support, and empowerment have positively influenced business performance, income generation, asset accumulation, and overall well-being of small-scale entrepreneurs in the sample area. It is recommended that microfinance institutions should continue to focus on expanding access to credit and other financial and advisory services to small-scale entrepreneurs to continuously improve their overall performance.

Determination of the Iron and Zinc Contents for Teff Types in The NorthWestern Part of Ethiopia

A simple and efficient method was used to determine the levels of iron and zinc in the teff flour samples. The aim of this study was to determine the concentration levels of iron and zinc in teff samples across different locations and to compare with other reported values due to different agricultural applications. The levels of Fe and Zn in the three types of teff samples collected from the three sampling areas were determined by using Micro-plasma atomic emission spectroscopy. The iron mean concentration of white teff was highest in the Bure site followed by Bahir Dar and Debre Markos sampling sites. The level of iron in the red teff was highest in the Debre Markos site followed by Bure and Bahir Dar sampling sites respectively. Similarly, the iron content of the mixed teff was highest in Bahir Dar site followed by Debre Markos and Bure sampling sites. However, the amounts of Zn determined in the three types of teff samples collected from the three different locations were almost similar. The overall mean concentrations determined (mg/kg, air dry weight) for the teff samples collected from the Bure, Debre Markos and Bahir Dar sites were in the ranges of Fe (719) > Zn (86) >, Fe (728) > Zn (87) and Fe (668) > Zn (73), respectively. The one way ANOVA indicated the mean concentrations of the two studied metals found in the three types of teff samples within and between the sampling sites was not significant at 95% confidence level.

Unveiling the Diversity and Ecological Roles of Macrofungi in Ayer Hitam Forest Reserve, Selangor, Malaysia

The biodiversity of macrofungi in remaining lowland dipterocarp forest in highly urbanization pressures is infrequently studied, even though their significant impact on the ecosystem of forested and non-forested habitats. Therefore, this research endeavours to unravel the diversity of macrofungi from different substrates in the Ayer Hitam Forest Reserve located in Selangor, Malaysia. Through a combination of field surveys, the study seeks to contribute valuable insights into the complex relationships between macrofungi and the surrounding habitats where macrofungal community structure was mainly influenced by substrate richness and microclimates. Sporocarps of macrofungi were collected from selected sites using opportunistic sampling methods. A total of 333 sporocarps were obtained and identified based on morphological and molecular analysis. Basidiomycota prevailed in the Ayer Hitam Forest Reserve where 27 species belonging to 14 families were successfully identified. Saprophytic fungi (22 species, 81.5%) dominated the areas, and a small number of mycorrhizal (1 species, 3.7%) and parasitic (4 species, 14.8%) fungi were found. Based on species diversity, order Polyporales is the highest occurrence species in the sampling areas with a Shannon-Weiner Index value of 2.103 and Simpson Index value of 0.954, Evenness Index value of 0.601, making it the most abundant order containing Microporus species, The findings are expected to enhance our knowledge of the biodiversity of macrofungi from different substrates in Ayer Hitam Forest Reserve, which can lead to conservation efforts and promote the ecological significance of macrofungi in tropical forest ecosystems.

ТЕСТИРОВАНИЕ ВОЗМОЖНОСТЕЙ МЕТОДИКИ ОПЕРАТИВНОГО МОНИТОРИНГА ГОРНО-ЛЕДНИКОВЫХ СИСТЕМ

The article considers the possibilities of assessing the glaciation area of ​​the Northern Ile and Ile-Kungey glacier systems based on monitoring data from a limited sample of test glaciers. During testing in each of the mentioned glacier systems, based on the data on the area of ​​two samples of 10 glaciers, their total sample (20 glaciers) and their share in the total area of ​​glaciers in each of the named glaciation regions, the area of ​​glaciers of the corresponding glacier system was calculated. According to the testing results, the values ​​of the correlation coefficient of the calculated and actual (based on the results of glacier cataloguing) values ​​of the glaciation area for the three mentioned glacier samples were 0.99, 0.98, and 0.99 for the Northern Ile glacier system and 0.99, 0.97, and 0.99 for the Ilei-Kungey, respectively. The testing results leave no doubt about the possibility of operational monitoring of the glaciation area dynamics of mountain glacier systems based on the data on the area of ​​a limited sample of glaciers of the corresponding glacier system with an error of no more than ±5 %. According to the testing results, the calculated values ​​of the glacier area of ​​the considered glacier systems in 88 % of cases were less than 5% of the actual values, and only in 4 cases out of 33 (12 %) they exceeded this threshold, with an average deviation of the calculated data from the actual values ​​of less than 2 % and the largest calculation errors of 7.8 and -9.6 %. This indicates the high efficiency of the method of operational monitoring of mountain glacier systems. It allows to rapidly (with a repeatability from once every few years to annually) assess the loss of perennial ice in the considered glacier system and the contribution of glacial meltwater to the formation of river flow. Which, in its turn, is a good basis for the corresponding modeling of current and predicted changes.

Assessent of tree diversity in the vegetation of ramna areas of dhaka city for better management

The present article deals with the evaluation of the existing tree species diversity in the Ramna areas of Dhaka city. Both random and stratified random quadrat sampling were used for the data collection from July 2021 to June 2022. The study identified a total of 156 tree species in 46 families. Among the sampling areas, 115 tree species were found in Ramna Park, 61 tree species in Suhrawardy Udyan, and 98 tree species in the Dhaka University area. The sampling areas overlapped significantly with many tree species. Among the species, 33% of the species were of ornamental value, followed by timber (24%), medicinal (21%), fruit (19%), and wildlife-supporting (3%). 51% of the species belonged to exotics and 49% were native. The most abundant species were Swietenia mahagoni in Ramna Park and Dhaka University and Eucalyptus camaldulensis in Suhrawardy Udyan. Based on the important value index, the most dominant species were S mahagoni in Ramna Park and Dhaka University and Ficus elastica in Suhrawardy Udyan. Among the top 15 most abundant and dominant trees, nine belonged to exotics, and the rest were native. The Shannon diversity index value ranged from 3.83 to 4.39. Ramna Park showed the highest index value (4.39), followed by Dhaka University (3.91) and Suhrawardy Udyan (3.83). Stakeholder’s consultations revealed that on average 90% of the support was found for management strategies such as native enrichment, reducing exotic dominance, planting purposeful trees, heritage plantations, and expert consultation during plantation. Identified threats included construction works, exotic presence, lack of native seedlings, and low awareness. Recommendations include promoting the dominance of native species, gradual exotic replacement, enhancing wildlife-supporting species, increasing public awareness, and integrating expert opinions into urban plantation programs. Bangladesh J. Bot. 53(3): 605-617, 2024 (September)

Spectro-environmental factors integrated ensemble learning for urban river network water quality remote sensing

Remote sensing water quality monitoring technology can effectively supplement the shortcomings of traditional water quality monitoring methods in spatiotemporal dynamic monitoring capabilities. At present, although the spectral feature-based remote sensing water quality inversion models have achieved many successes, there could still be a problem of insufficient generalization ability in monitoring the water quality of complex river networks in large cities. In this paper, we propose a spectro-environmental factors integrated ensemble learning model for urban river network water quality inversion. We analyzed the correlation between water quality parameters, spectral reflectance, and environmental factors based on an in-situ dataset collected in the northern part of Shanghai. Using the Hot Spot Analysis (Getis-Ord Gi*), we found that river network water quality parameters have different patterns in different urban functional zones. Furthermore, daily average temperature, total rainfall within the seven days, and several band combinations were also selected as the environmental and spectral features using factor analysis and Pearson correlation coefficient analysis. After the feature analysis, the spectro-environmental factors integrated ensemble learning model was trained. Compared with the spectral-based machine learning inversion models, the coefficients of determination R2 increased by about 0.50. Our model was also tested in three different test areas within and outside the in-situ sampling areas in Shanghai based on low-altitude multispectral remote sensing images. The R2 results for total phosphorus (TP), ammonia nitrogen (NH3-N), and chemical oxygen demand (COD) within the in-situ sampling areas were 0.52, 0.58, and 0.56 respectively. The mean absolute percentage error (MAPE) results were 53.36%, 63.95%, and 22.46% respectively. After adding the area outside the in-situ sampling areas, the R2 results for TP, NH3-N, and COD were 0.47, 0.47, and 0.53. The MAPE were 49.38%, 74.46%, and 20.49%. Our research provided a new remote sensing water quality inversion method to be utilized in complex urban river networks which exhibited solid accuracy and generalization ability.

Crucible-less Processing of Ti with TiC Heterogeneous Nucleation Site Particles by Electrostatic Levitation

In this study, the microstructure, hardness, density, viscosity, and surface tension of molten pure Ti with TiC particles were studied via electrostatic levitation experiments, where the electrostatic levitation experiment involved container-less processing, which can suppress heterogeneous nucleation via crucibles. Microstructural observation revealed long needle-shaped α-grains across the whole area in the pure Ti sample. On the other hand, smaller needle-shaped α-grains were found in the samples with TiC particles. However, the detailed microstructural analysis of Ti + 0.7vo l%TiC sample revealed that the fine α-grains observed in the Ti + 0.7vo l%TiC are transformed from single grain of prior β phase. This is because the TiC particles dissolve into the molten Ti during the electrostatic levitation experiment. Instead, Ti–rich TiC precipitates formed by cooling can act as pinning sites rather than heterogeneous nucleation sites, which results in a finer microstructure for the samples with TiC particles during the electrostatic levitation experiment. The density of the samples is linearly related to the temperature, and it decreases with increasing temperature. In addition, a higher density is observed for the samples with TiC particles. Although linear relationships between the surface tension and temperature were found, the addition of TiC particles had no notable effect on the viscosity of the molten pure Ti.

Influence of Supercritical Conditions on Isothermal Adsorption Capacity Calculation of Methane and Model Optimization.

The study of isothermal adsorption models for coal and methane under supercritical conditions helps us to understand the gas content distribution in coal seams and improve gas management in coal mines. Coal samples from the Hebi mine and Longshan coal mine were selected for this research. Using the weight method, isothermal adsorption curves of supercritical methane at temperatures of 308, 313, and 318 K were measured. The adsorption phase density of supercritical methane was obtained by using the intercept method and model fitting, and the absolute adsorption capacity of methane was calculated. Simultaneously, the pore volume and specific surface area of the coal samples were tested, and the isothermal adsorption model for supercritical methane was studied and optimized. The results indicate that using mercury intrusion, low-temperature N2, and low-temperature CO2 adsorption methods for testing coal sample pore structures allows for multiscale characterization of the coal pore structure. Based on the Gibbs excess adsorption theory, the phase density of methane obtained from the intercept method and model fitting effectively represent the isothermal adsorption curve of supercritical methane. By combination of the specific surface area and pore volume distribution of the coal with the absolute adsorption capacity of methane, the number of methane adsorption layers on the coal surface was calculated to be between 1.11 and 1.3 layers. This suggests that the isothermal adsorption model for supercritical methane on coal is not solely micropore filling or single molecular layer adsorption but primarily single molecular layer adsorption with concurrent micropore filling adsorption. Based on this adsorption mechanism, an L-DA isothermal adsorption model for supercritical methane on coal was established. The L-DA isothermal model shows good fitting results and effectively explains the adsorption characteristics of supercritical methane on coal.