Changes In Surface Characteristics Research Articles

Temporal stability and spatial dependency of pixel-specific red-NIR soil lines from multi-temporal satellite remote sensing imagery

ABSTRACT The temporal stability and spatial dependence of pixel-specific red-NIR soil line coefficients were studied using analyses of geostatistics and covariance. We used time series of MODIS 8-day composite reflectance data from 2000 to 2019 of bare soil surfaces near Kabul, Afghanistan. The goal was to explore the feasibility of reducing the soil background signal in red-NIR vegetation indices (VIs). The results were that 1) Red-NIR pixel-specific soil line coefficients can be obtained using multi-temporal remote sensing imagery; 2) pixel-specific Red-NIR soil line coefficients derived from multi-temporal remote sensing imagery exhibit clear spatial dependency related to the soil line coefficients of soils sampled in the field, and 3) Red-NIR pixel-specific soil line coefficients were stable for years, but showed instability for periods longer than 16 years. These results imply that A) some changes in soil surface characteristics can be deduced using long-term observations, B) pixel-specific Red-NIR soil lines at any location can be estimated by kriging interpolation. Consequently, soil line coefficients derived from multi-temporal satellite observations can be used to derive information about vegetation, such as the germination stages pixel-by-pixel or above-ground biomass in sparsely vegetated lands. The derived values should be valid over wide areas, minimizing soil background effects.

Fabrication of the PES Membrane Embedded with Plasma-Modified Zeolite at Different O2 Pressures.

In this research, the non-thermal glow discharge plasma process was implemented to modify the surface of natural clinoptilolite zeolite before incorporation into the polyethersulfone (PES) membrane. The influence of plasma gas pressure variation on the fouling resistance and separation performance of the prepared membranes was studied. Fourier transform infrared, field emission scanning electron microscopy, and X-ray diffraction analyses of the unmodified and modified clinoptilolites revealed the Si-OH-Al bond's development during plasma treatment and the change in surface characteristics. In terms of performance, increasing the plasma gas pressure during clinoptilolite treatment resulted in the twofold enhancement of water flux from 91.2 L/m2 h of bare PES to 188 L/m2 h of the membrane containing plasma-treated clinoptilolite at 1.0 Torr pressure. Meanwhile, the antifouling behavior of membranes was improved by introducing more hydrophilic functional groups derived from the plasma treatment process. Additionally, the enhanced dye separation of membranes was indicated by the separation of 99 and 94% of reactive green 19 and reactive red 195, respectively.

Adsorption of heavy metals on biodegradable and conventional microplastics in the Pearl River Estuary, China

In recent years, microplastics (MPs) as emerging carriers for environmental pollutants have attracted increasing worldwide attention. However, the adsorption of heavy metals on MPs, especially for biodegradable MPs, has been still poorly understood in estuarine environments. In this study, we investigated the aging of biodegradable and conventional MPs in the Pearl River Estuary after long-term exposure and their impacts on the adsorption of heavy metals from seawater. The results showed that the changes in surface characteristics were more prominent on biodegradable MPs than on conventional MPs after aging. Both biodegradable and conventional MPs could adsorb heavy metals, and their adsorption capacities fluctuated greatly on different MPs and different exposure times. The adsorption capacities of Cu, Pb, and As on biodegradable MPs were higher than those on conventional MPs, whereas Mn, Cr, and Co had lower adsorption on biodegradable MPs after 9–12 months by inductively coupled plasma-mass spectrometry (ICP-MS). The aging characteristics (CI, O/C, and Xc) of MPs accounted for a contribution of 51.0% on heavy metal adsorption, while the environmental factors (temperature, salinity, pH, and heavy metal concentration) only contributed to 13.2%. Therefore, the present study can provide important evidence on the environmental behaviors and ecological risks of biodegradable and conventional MPs in estuarine systems.

High performance, low‐fouling nanocomposite membrane with TiO2 nanomaterial in polysulfone matrix for advanced water treatment

AbstractIn the present article, nanocomposite TiO2/polysulfone membranes were prepared for advanced water treatment and removal of surfactant and dye from water were evaluated. The nanocomposite membranes demonstrated enhanced antifouling properties. Scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, atomic force microscopy, and transmission electron microscopy were conducted to characterize particles and fabricated nanocomposite membranes. The antifouling characteristics of the membrane were assessed by ultrafiltration of model foulants such as sodium alginate and egg albumin and it was found that the nanocomposite membranes were less prone to fouling. Separation performance of Congo red dye and non‐ionic surfactant Triton X‐100 were evaluated and the nanocomposite membranes have shown encouraging results. With incorporation of TiO2 nanoparticles, ultimate tensile strength increased while elongation at break decreased. Decrement in pore size with incorporation of nanomaterial and change in surface characteristics were responsible for improved performance of membrane.

Improved Method to Characterize Leaf Surfaces, Guide Adjuvant Selection, and Improve Glyphosate Efficacy.

Glyphosate, one of the most widely used herbicides, plays an important role in controlling weeds and ensuring crop production. While using glyphosate, adjuvants are commonly added to improve its deposition on weeds and control efficacy. However, changes in weed leaf surface characteristics may reduce glyphosate penetration and contribute to evolved glyphosate resistance. Therefore, it is significant to introduce an improved method for regularizing leaf surface characterization and guide adjuvant selection to improve glyphosate efficacy. In this work, surface characteristics of typical weed leaves have been systematically investigated by 3D surface analysis and scanning electron microscopy, finally quantified by apparent surface free energy (ASFE) due to its comprehensive and quantitative evaluation of leaf surfaces. Moreover, the relationship between the weed leaf surface characteristics and the retention of glyphosate on weeds was established, further related to the control efficacy against weeds. To maximize the utilization rate of glyphosate, the types and concentrations of adjuvants should be regulated according to the ASFE of weeds. Our findings not only regularize the surface properties of weed leaves but also reveal their influencing mechanism on the deposition and biological activity of glyphosate, which provide effective guidance for the use of glyphosate.

Statistical evaluation of the effects of surface processing on aerospace fastener tested strength

In the aerospace industry, various surface processing or coatings are widely used. It is known that surface processing can affect tested strength values. However, no detailed research on the aerospace fastener tensile and double shear strength variation due to surface processing has been conducted. Thus, the purpose of this study was to systematically evaluate the effect of surface processing on the standard aerospace fastener's tensile and shear properties. We selected three of the most common fastener finishes, including bare, passivation, and dry film processing. We conducted statistical analyses to identify the relationship between surface friction and tested strength. Our results showed that fastener tensile and double shear strength decreased in the groups that received surface processing compared to the bare group. This decrease was likely due to a change in surface characteristics, such as the friction coefficient instead of intrinsic material degradation due to surface processing. This evaluation may provide a solid foundation to gauge the true strength to improve aerospace fastener processing.

Detail Injection-Based Spatio-Temporal Fusion for Remote Sensing Images With Land Cover Changes

Spatio-temporal fusion can generate time-series images with high spatial resolution, and it is highly desirable in various applications, especially in monitoring fine dynamic changes of surface features on remote sensing images. Currently, most spatio-temporal fusion methods predict the target fine image by employing the auxiliary fine images on neighboring phases; however, they are generally limited in abrupt land cover changes between the target and the neighboring auxiliary images. In this paper, we propose a novel Detail Injection-based Spatio-Temporal Fusion (DISTF) model to alleviate this problem, by exploring the inherent relationship between the spatio-temporal fusion and spatio-spectral fusion. The proposed DISTF consists of three modules: a Three-branch Detail Injection (TDI) module, a Fine Detail Prediction (FDP) module, and a reconstruction module. The interpretable TDI module is inspired by spatio-spectral fusion, aiming to inject the non-changed detail information extracted from the neighboring fine images into the target coarse image, which can preserve the abrupt change information captured in the target coarse image. The FDP module is designed to further integrate the correlated information from the outputs of TDI and refine the spatial-spectral information to boost the fusion accuracy. Finally, the reconstruction module and the hybrid loss function are designed to more effective reconstruct the high-quality target fine image. The qualitative and quantitative experiment results on two datasets with different types of changes demonstrated that the proposed DISTF method achieves richer spatial detail and more accurate prediction than the eight existing methods.

Influence of N doping on structural and photocatalytic properties of hydrothermally synthesized TiO2/carbon composites

N-doped TiO2/carbon composites (TiO2/CN) with different nitrogen content, were obtained starting from titanium isopropoxide and glucose, and by varying the amount of melamine, added to starting reaction mixture. For comparison, an undoped sample (TiO2/C) was also prepared. Structural and surface characteristics were determined through scanning electron microscopy, thermogravimetric analysis, elemental analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and nitrogen adsorption? desorption isotherms. The photocatalytic activity of TiO2/CN composites was examined via photocatalytic degradation of methylene blue and multiclass pharmaceuticals from water solution. It was found that N doping of TiO2/carbon composites induced changes in structural and surface characteristics of TiO2/CN composites, improving their adsorption, but decreasing photocatalytic efficiency. Nevertheless, TiO2/CN0.05 composite obtained by the hydrothermal synthesis in the presence of glucose and 0.05 g melamine showed the highest efficiency for removing selected pharmaceuticals and methylene blue from aqueous solutions through the combined processes of adsorption in the dark, and photocatalytic degradation under UV and visible irradiation.

Dissolution does not affect grass phytolith assemblages

Dissolution is one among several taphonomical processes that may bias paleoenvironmental, paleoclimatic or taxonomic interpretation of phytolith assemblages. To improve our understanding of dissolution on grass phytoliths, we studied systematic changes of surface features, morphotype assemblages, and dissolution rates of phytoliths extracted from two grass species Hyparrhenia involucrata (Panicoideae), Nastus borbonicus (Bambusoideae), one soil from La Réunion Island (approximate mean age < 800 yr), and three paleosols from Ethiopia (approximate age of 4.4 million years). We used heavy-liquid to extract phytoliths, and 1% Na2CO3 to perform partial dissolution experiments. Physicochemical surface properties, morphotypes, and assemblages were analyzed using optical and scanning electron microscopy, laser diffraction, and X-ray diffractometry. Our results show that 1) phytoliths from different grass species may have different dissolution rates: phytoliths from the leaves of Hyparrhenia involucrata (Panicoideae) are more prone to dissolution than those from Nastus borbonicus (Bambusoideae). 2) Silicon (Si) released by phytolith assemblages (i.e., phytolith dissolution rate) decreases as follows: plant > soil > paleosol. 3) Dissolution leads to cavity formation on phytolith surfaces and disappearance of fragile silica particles. 4) Partial dissolution does not significantly change percentages of common grass phytolith morphotypes in a given assemblage. These results provide a benchmark for assessing the reliability of paleoenvironmental reconstructions using grass phytolith assemblages from buried soils and sediments.

Self-functionalization of soil-aged biochar surfaces increases nitrate retention

Nutrient retention in biochar amended soil has yielded variable results, with poorly understood mechanisms. Identification of changes on biochar surfaces during in situ soil aging can provide mechanistic information on the role of biochar on nutrient retention. In the current greenhouse study, we analyzed changes of biochar surface characteristics from aging in two soils with different iron levels and amended with two types of manure under corn. On pristine biochar surfaces, we detected no iron species. In contrast, after soil aging (70 days), a self-functionalization of biochar surfaces with iron oxides was observed, which can be explained by soil redox cycles allowing reduced iron(II) to migrate on biochar surfaces followed by its re-oxidation. This self-functionalization is proposed as an underlying mechanism explaining the significantly (p < 0.01) increased nitrate retention by 29–180 % in biochar amended soil. Significant (p < 0.05) reductions in leachate phosphate (18–41 %) and dissolved organic carbon (8.8–55 %) were also observed after biochar surface functionalization. Our results indicate that redox-driven iron oxide formation on surfaces of biochar in the soil can be a critical process explaining the dynamic nature of nutrient retention observed in biochar amended soils. Identifying soil environmental conditions most beneficial for such surface functionalization, which has the potential to increase nutrient retention, is critical for implementing efficient biochar amendment strategies and for increased resource efficiency in agroecosystems.

Modification of waste sugarcane bagasse fly ash for CO2 capture application

CO2 capture is a promising approach to aid in the mitigation of the global environmental crisis caused by greenhouse gas emissions. The efficiency of adsorbents is critical to the success of this approach. Sugarcane bagasse fly ash (SBA) was used in this study as a support to increase the CO2 adsorption capacity of CaO. The physical and chemical characteristics of SBA treated with various reagents (HCl, H3PO4, CH3COOH, NaOH, NH3, and H2O2) were investigated. The CaO was then loaded at 10–50 wt% on the support surface, and the modified adsorbent was tested for its potential to adsorb CO2. According to the results of the experiments, the acidic reagent increased the surface area of SBA, whereas the base reagents provided SBA with a higher pore volume and a larger pore size. The different surface characteristics of the modified SBA had a direct impact on its CO2 adsorption capacity. The adsorbent with NaOH-pretreated SBA and 50% CaO loading had the highest CO2 adsorption capacity, which was 27% higher than that of unsupported CaO due to the decent distribution of CaO found on the NaOH-treated SBA surface. For a better understanding, a graphical model was finally proposed to describe the aforementioned changes in surface characteristics and adhesion of CaO on the SBA support. These findings show that SBA, a valueless bagasse-incinerating waste material, can be used as a support to increase the CO2 adsorption capacity of adsorbents, transforming it into a more valuable and environmentally sustainable material.Graphical abstract

Change in surface characteristics and permeability of human enamel after subjecting to radiation therapy.

Radiation-related caries is a complex destructive lesion leading to uncompromising damage of enamel and dentin in patients suffering from head and neck cancer managed with radiotherapy. The purpose of this study was to evaluate the changes in the permeability of enamel and to assess the morphological and chemical changes of teeth surface subjected to 6 MV photon beam irradiation. For this in vitro study, coronal portion of 20 premolars were sectioned mesiodistally into halves and then grouped into two. Samples in group 1 (control) were not subjected to cycles of irradiation and those in group 2 (experimental) were subjected to a cumulative uniform radiation dose of 70 Gray fractioned in 35 fractions with 6 MV photons. The silver nitrate penetration method was used to assess the change in permeability of enamel. The variations in surface topography and mineral content were assessed using scanning electron microscopy with energy dispersive X-ray analysis. Dye penetration scores of surface texture changes were compared between the two groups utilizing the Chi-square test. The change in the elemental levels between enamel surfaces of the two groups was compared using an independent t-test. The application of 6 MV photon radiation did not change enamel permeability and surface topography. However, a noteworthy reduction in the carbon content (P = 0.002) was observed in teeth subjected to irradiation. Though radiation exposure did not alter the enamel permeability and surface topography, it had caused significant chemical compositional changes. Carbon content was significantly reduced in irradiated enamel samples.

Biochemical and Ultrastructural Studies for Toxicity of Kaempferol Derivative Recovered from the Plant Lysimachia Ramosa

Leaves of Lysimachia ramosa are used by various tribes of Meghalaya to cure intestinal helminth infections. Preliminary investigations disclosed impressive anthelmintic effects of the kaempferol derivative, an active component of the plant, however, toxic effects on its consumers, if any, are not known. Therefore, the present study has been undertaken to investigate the acute and sub-acute toxic effects of kaempferol derivative, of the plant, taking Wistar rats as a model. Following OECD 407, 250 mg, 500 mg, and 1000 mg/kg body weight doses of the active component have been selected to treat the animals for 28 days. On the 29th day, the animals have been sacrificed to assess different toxicological effects on animals. The LD50 value of the anthelmintic component was found to be more than 5000 mg/kg body weight of rats. Histological, ultrastructural, haematological, biochemical, andorgano-somatic (HSI and RSI) studies demonstrate changes in surface characteristics of various cellular organelles of different vital organs such as the liver, kidney, and intestine. Alterations were also recorded in different vital enzymes such as AST, ALT, and ALP in the phytochemical exposed rats at higher doses. The results revealed that treatment with the active component at a higher concentration may lead to toxicological effects if treatment persists for a longer period.

Surface Characterization of Lüders Band on NiTi Shape Memory Alloy

The tensile deformation of NiTi alloy can proceeds in either homogeneous manner, or localized deformation via formation and propagation of macroscopic shear bands, that is commonly known as Lüders-like deformation. The high deformation strain within the localized deformed regions can result in the changes of surface characteristics of NiTi specimen. This paper studies the surface roughening effect associated with Lüders-like deformation of martensitic NiTi alloy, via surface characterization of polished surface and localized deformed region that consists of Lüders bands on tensile specimens, respectively. The surface roughness profile and roughness parameters of surface with Lüders bands are significantly different and higher as compared to the polished surface.

Physicochemical and biological ageing processes of (micro)plastics in the environment: a multi-tiered study on polyethylene

Pollution by plastic and microplastic impacts the environment globally. Knowledge on the ageing mechanisms of plastics in natural settings is needed to understand their environmental fate and their reactivity in the ecosystems. Accordingly, the study of ageing processes is gaining focus in the context of the environmental sciences. However, laboratory-based experimental research has typically assessed individual ageing processes, limiting environmental applicability. In this study, we propose a multi-tiered approach to study the environmental ageing of polyethylene plastic fragments focusing on the combined assessment of physical and biological processes in sequence. The ageing protocol included ultraviolet irradiation in air and in a range of water solutions, followed by a biofouling test. Changes in surface characteristics were assessed by Fourier transform infrared spectroscopy, scanning electron microscopy, and water contact angle. UV radiation both in air and water caused a significant increase in the density of oxidized groups (i.e., hydroxyl and carbonyl) on the plastic surface, whereby water solution chemistry influenced the process both by modulating surface oxidation and morphology. Biofouling, too, was a strong determinant of surface alterations, regardless of the prior irradiation treatments. All biofouled samples present (i) specific infrared bands of new surface functional groups (e.g., amides and polysaccharides), (ii) a further increase in hydroxyl and carbonyl groups, (iii) the diffuse presence of algal biofilm on the plastic surface, and (iv) a significant decrease in surface hydrophobicity. This suggests that biological-driven alterations are not affected by the level of physicochemical ageing and may represent, in real settings, the main driver of alteration of both weathered and pristine plastics. This work highlights the potentially pivotal role of biofouling as the main process of plastic ageing, providing useful technical insights for future experimental works. These results also confirm that a multi-tiered laboratory approach permits a realistic simulation of plastic environmental ageing in controlled conditions.

Toxicity of tire wear particles and the leachates to microorganisms in marine sediments

Tire wear particles (TWPs), which are among the microplastic pollutants in the environment, can inevitably accumulate in coastal sediments. The present study comprehensively investigated the effect of pristine TWPs on bacterial community structure in coastal sediments and compared the effect of pristine TWPs and aged TWPs on nine strains of bacteria in sediments. In addition, the effect of the TWP leachate was studied with all the nine bacterial strains and the toxicity-causing substances in the leachate was investigated using Bacillus subtilis. Exposure to TWPs could lead to a shift in bacteria community and affect nitrogen metabolism in marine sediments. Aged TWPs were more toxic than pristine TWPs due to changes in particle surface characteristics. The leachate exhibited greater toxicity than TWPs as well, and Zn was identified to be the major toxicity-causing substance. The overall results of this study are important for understanding the effects of TWPs and the leachates on microorganisms in marine sediments.

The Influences of Climatic and Lithological Factors on Weathering of Sediments in Humid Badland Areas

Climate variables including temperature, rainfall intensity, rainfall acidity, and lithological properties are among the most important factors affecting rock weathering. However, the relative contribution of these four factors on rock weathering, especially on chemical weathering, is still unclear. In this study, we carried out a series of weathering-leaching rainfall simulations on four types of badland sediments under controlled conditions of two levels of temperature, rainfall intensity, and rainfall acidity based on the real field data from representative weather scenarios. The main objectives are 1) to explore the progressive change of sample surface and leachate characteristics and 2) to reveal the independent effects of temperature, rainfall intensity, rainfall acidity, and lithology and their relative contribution as well, on both mechanical and chemical weathering. Qualitative analysis on crack development and fragmentation of sample surface and quantitative analysis on the leachate volume, pH, electrical conductivity, and total cation and anion releases of sample leachate together demonstrated that for the investigated sediments, under the conditions of temperature, intensity, and acidity of rain that can be achieved in nature, high drying temperature obviously increases mechanical disintegration by promoting the rate and magnitude of moisture variations (wetting–drying alterations), while high rainfall intensity and acid rain have no obvious effect. Impact and importance of the drying process caused by high temperature between wetting events need more attention, rather than high rainfall intensity. Low temperature, high rainfall intensity, and acid rain contributing more hydrogen ions required for cation exchanges, rock type with more soluble minerals, all promote chemical weathering, and the influence of climatic and lithological factors on chemical weathering decreases in the following order: mineral composition&amp;gt; rainfall intensity &amp;gt; temperature &amp;gt; rainfall acidity. Climatic variations on temperature can modify weathering processes and in that way conditioned hydro-geomorphological processes in badland areas. Such changes should be considered for direct and indirect implications on badland dynamics.

Mobile technology of thermal modification of wood

Wood as a structural material has a number of disadvantages, including a short service life, relatively low dimensional stability, significant volumetric deformations under the influence of moisture, pronounced anisotropy and water absorption. Thermomodification slightly improves physical and mechanical properties, but the problem of changing surface characteristics, in particular adhesion, arises. In order to determine the technological characteristics of thermally modified wood and to develop possible measures to improve the technology of applying protective coatings, the surface energy and compressive strength limit along the fibers were determined. A comprehensive approach is applied to analyze the state of the thermally modified wood surface through the study of surface energy characteristics based on the Fowkes method, which takes into account dispersion, hydrogen and dipole-dipole interactions at the solid-liquid interface. According to the marginal angle of wetting, it was found that the process of thermal modification wood helps to increase the resistance of its surface to wetting due to a decrease in polarity by 1.68 times with an increase in the duration of modification to 30 min. At the same time, the surface free energy for samples modified at 300 °C for 5 min. is 64.5 mJ/m2, during 30 min. – 24.1 mJ/m2. Regarding compressive strength, thermal modification reduces the strength limit by 1.46 times. At a temperature of 300 ºС and a time of 5 min. and 15 min. the indicator remains at the level of ordinary wood – 42 MPa. Treatment for 30 min. reduces the strength limit to 29 MPa, wood loses plasticity. The obtained results make it possible to effectively choose stable coatings for such wood for high-quality surface treatment with paint and varnish materials. Knowing the moment of time from which the reduction of the strength limit begins, conducting the process of thermal modification becomes more controlled and makes it possible to predict the characteristics of the future material

Preservation of Titanium in a Naringin-Containing Solution to Enhance Osteogenic and Anti-inflammatory Activities In Vitro

When exposed to air, the titanium implants undergo changes in surface characteristics and biological activity, which is known as biological aging. It is important to find a suitable storage method to slow down the biological aging of titanium. The purpose of this study was to develop a naringin-containing storage solution and evaluate the effects of this storage method on physicochemical properties as well as osteogenic and anti-inflammatory activities of commercial pure titanium (cp-Ti) and sandblasted with large grit and acid-etched titanium (SLA-Ti). Titanium surfaces stored in air and 0.9% NaCl solution for 4 weeks were served as control, and samples submerged in three different concentrations of naringin-containing solution for 4 weeks were used to investigate the new storage method. Surface topography images showed that nanostructures were observed on liquid-stored SLA-Ti surfaces. The storage condition did not influence the roughness of both cp-Ti and SLA-Ti. However, the wettability of titanium varied with the storage methods. Titanium stored in the naringin-containing solution exhibited lower contact angles. Samples stored in aqueous solution were less susceptible to hydrocarbon contamination. The preservation of titanium in the 10 μM naringin-containing solution enhanced the adhesion, proliferaton, and differentiation of osteoblasts. In addition, macrophages on samples stored in 10 μM and 100 μM naringin-containing solutions displayed better anti-inflammatory effect. In summary, the 10 μM naringin-containing solution could enhance osteogenic and anti-inflammatory activities of titanium and was proved to be an effective new storage condition.

Review: land, cloud, and climate change (in focus: Borneo)

This article discusses the salient findings of the Intergovernmental Panel on Climate Change Special Report on Climate Change and Land (2019). Local impacts of global warming in Borneo are discussed in terms of changes in temperature and precipitation. A drier and warmer climate is expected with the continued deforestation of Borneo. Changes in land surface characteristics of Borneo also affect the properties of cloud that forms over it. Deforested areas are generally associated with diffused clouds, small cloud particles, and thin and high clouds. Low vegetative areas are associated with a low evapotranspiration rate and low amount of latent heat release, which discourages the formation of convective clouds. The weak updraft associated with a non-convective cloud cannot support the formation of large cloud droplets. Moreover, the deforestation of primary forests of Borneo and replacing them with palm trees may cause larger cloud properties’ variability over the area.