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P91 and P92 steels are widely used in nuclear and thermal power plant's high-temperature (650–700 °C) operating components. The welding procedure, base plate composition, filler material composition, and post-weld heat treatment (PWHT) significantly affect the metallurgical characterization of weldments at room temperature. This work focuses on joining P91 and P92 steel by the TIG welding with filler ER90S-B9. The study analyzes the materialization of coarse-grained HAZ (CGHAZ), inter-critical HAZ (ICHAZ), and fine grained HAZ (FGHAZ) under welded and PWHT. PWHT was conducted at 840 °C for 2, 4 and 6h. An optical microscopic (OM) scanning electron microscope (SEM) was employed to characterize the welded and PWHT samples. It was perceived that the tensile strength of PWHT increased as the heat treatment times increased from 2 to 6 h, while the hardness value decreased accordingly. The maximum tensile strength (594.71 MPa) was observed in PWHT_6 h, while the minimum tensile strength (537.52 MPa) was perceived in the as-welded sample. The PWHT_6h reveals the minimum hardness values (271.12 HV) at the fusion zone among all the conditions. The WFZ consisted of an untampered lath martensitic grain structure, demonstrating an average hardness value of 314.15 HV in the PWHT_2h condition. The hardness value in CGHAZ samples for as-welded, PWHT_2h, PWHT_4h, and PWHT_6h was observed at 456.85, 436.81, 368.63, and 327.41 HV, respectively. [ABSTRACT FROM AUTHOR]

Multi-walled carbon nanotubes (MWCNTs) have significant environmental concerns for soil, water and ecosystems. Since their harmful effects on human health, including respiratory disease, they are considered dangerous substances. Thus, it is required to discover a constructive solution to decrease of MWCNT toxicity. Due to their high degradability, white rot and soft rot fungi have been used in the biodegradation of various pollutants. In this study, we evaluated the ability of native Iranian white and soft rot fungi to degrade MWCNTs mainly by means of dynamic light scattering (DLS) and surface charge measurement. In this regard, growth kinetics, CO2 and protein production, size, surface charge and pH change were measured. Continuous Raman spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM) imaging were carried out to detect the process of degradation. The results showed that the morphology, arrangement, size and diameter of MWCNTs were modified due to fungal degradation. The cytotoxicity of treated MWCNTs was determined by the MTT test. The results indicated that native Iranian white and soft rot fungi have a significant ability for degradation of MWCNTs. Furthermore, it could be concluded that fungal treatment could reduce the toxicity of MWCNTs and the best result was achieved in 500 ppm MWCNTs for Trichoderma sp. The activities of oxidative enzymes such as laccase, manganese peroxidase (MnP) and lignin peroxidase (LiP) were measured to determine the mechanism of degradation. Enzyme assays have suggested that these oxidising enzymes especially laccase might play a key role in the degradation of MWCNTs in white rot and soft rot fungi. The overall results confirmed the reproductive ability of Trichoderma sp. WF29 as a soft rot and two white rot fungi Irpex lacteus WF36 and Trametes versicolor to degrade MWCNT. [ABSTRACT FROM AUTHOR]

Unburned carbon from fly ash and its graphitization products (at temperatures of 2400 and 3000°C) were tested using scanning electron microscope (SEM), X-ray diffraction (×RD) and micro-Raman spectroscopy. The same tests were also carried out for synthetic and natural graphite. Various morphological forms of products with a high degree of graphitization, such as spheroidal graphite, hexagonal plates, column plates, and jagged-edge films were identified in the sample of unburned carbon annealed at 3000°C. The product of thermal treatment at the temperature of 3000°C has the interlayer spacing d002 value characteristic for semigraphite. With increasing temperature the number of crystallites in stack N, their height Lc002 and aromaticity fa increases. The degree of G graphitization of annealed samples increases more than twice with increasing temperature. With the increase of the temperature the aliphatic chains are decomposed and the aromatic systems are reconstructed, so the degree of internal structure order increases. The Raman examinations showed that the structural parameters determined for the graphite and carbonizate samples after thermal treatment at the temperature of 3000°C are equal in the standard deviation range. [ABSTRACT FROM AUTHOR]

Plant-mediated processes offer a more straightforward and cost-effective alternative to conventional chemical and physical methods for the reduction of silver ions to silver metallic nanoparticles. This study was conducted to synthesize silver nanoparticles (AgNPs) using a solution of silver nitrate (AgNO3) and a local Basciftlik white potato cultivar (S. tuberosum). Furthermore, the study aimed to compare antioxidant activity of nano-silver particles with that of the potato extract. The potato cultivar was extracted with deionized water and the solution was filtrated. The filtrate was reacted with AgNO3 solution to obtain the AgNPs. The structure of synthesized AgNPs was determined by a spectroscopic study, and characteristic functional groups were analyzed by a fourier-transform infrared spectroscopy (FTIR). The signal observed at 3267 cm−1 is indicative of the hydroxyl functional group. The highest absorption at 429 nm in ultraviolet-visible (UV-VIS) spectrum confirmed the occurrence of the synthesized AgNPs. The biogenic crystalline structure of the synthesized AgNPs was verified by an X-ray diffraction analysis. Average size and morphology of the St-AgNPs were determined by Scanning Electron Microscope analysis, which also indicated the formation of the AgNPs with an average size of 37.31 nm. Antioxidant activity study revealed that the synthesized AgNPs had higher antioxidant activity compared to that of the potato extract alone. [ABSTRACT FROM AUTHOR]

Today, increasing dyes pollution is of great importance for life. Leaving the dyes used in industries such as textiles without being discharged pollutes other water sources. In order to prevent this, different methods are used in the literature. In this study, SrAl2B2O7, a borate metal, was used to remove methyl blue (MB), an anionic dye, by batch adsorption method. Strontium aluminoborate (SrAl2B2O7) was prepared using a solution combustion method at 950 °C for 4 h in air. The prepared adsorbent was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The particle morphology of the adsorbent was investigated using scanning electron microscope (SEM). By using N2 adsorption–desorption, the Brunnauer, Emmet, and Teller (BET) specific surface area was found to be 1.9578 m2 g−1. The surface charge of the dye-adsorbed SrAl2B2O7 was determined based on zeta-potential measurements. Langmuir (R2=0.9897), Freundlich (R2=0.985), Dubinin & Radushkevic (R2=0.976), Scatchard (R2=0.881), Temkin & Pyzhev (R2=0.978) isotherms were calculated in the study. SrAl2B2O7 showed good adsorption performance for methyl blue (MB) with maximum adsorption capacities of 29.069 mg g−1 (Langmuir). Adsorption processes were also studied in detail. Thermodynamic and kinetic models; pseudo-first-order (R2=0.415), pseudo-second-order (R2=0.999), Elovich (R2=0.968) showed that adsorption using SrAl2B2O7 in MB removal is endothermic and pseudo-second order. [ABSTRACT FROM AUTHOR]

Hydraulic fracturing effectively enhances production in the unconventional oil and gas industry. As we all know, proppant plays a vital role in the hydraulic fracturing. In this paper, the effects of proppant type, particle size, concentration, closure pressure, and other factors are studied by laboratory experiments. Based on the actual triaxial simulation device (TSD), quartz sand, ceramic, and coated sand are used as proppant, while sandstone, coal rock, shale, and granite are selected as the stone slate to experiment. The surface of the proppant was imaged by a surface profiler (SP) and scanning electron microscope (SEM) to compare the microscopic surface characteristics before and after the experiment. The particle size macroscopic distribution was measured by Mastersizer 2000. The results and innovation are as follows: This paper investigates the proppant crushing for hydraulic fracturing and provides an alternative evaluation method for proppant selection. The crushing laws of proppant under different pressures and stone slate are compared by using the experimental device. It is reliable for quartz sand to replace ceramic in deep layer of the field application. It also overturns the previous thinking. We believe this found holds the key toward systematically optimizing the development of unconventional reservoirs. [ABSTRACT FROM AUTHOR]

Friction Stir Welding is a process that has led to increasing usage of aluminum and its alloys in different industries, since it is an autogenous and a solid-state welding process. The work developed in this paper was focused on the analysis of the mechanical behavior of AA7075-T651 friction stir butt welded joints, of 4 mm of thickness, under different loading and temperature conditions. A selection process was applied to assure the appropriate welding parameters. The welds from which the investigated specimens were manufactured from were submitted to nondestructive testing to assess the presence of welding defects. Fatigue tests were carried out, under a constant amplitude loading regime, at stress ratios of 0.05 and 0.5 and at temperatures of 23 °C and 150 °C. The results obtained by the fatigue tests point to a higher fatigue life of the specimens when the highest stress ratio, R = 0.5, was used (for the maximum stress applied), for both loading temperatures. For the stress range, the contrary was found to be true. Room temperature was also found to result in a significantly better fatigue performance. A Scanning Electron Microscope was used to characterize the fatigue fracture surfaces. [ABSTRACT FROM AUTHOR]

Cement-based cementing materials have some disadvantages, such as high brittleness and poor mechanical properties. In the long-term production process of oil and gas wells, it is easy to damage, resulting in annulus pressure and interlayer channeling. However, curable resin-based cementing materials have the advantages of good toughness, high strength, and low elastic modulus, and have the potential as cementing materials. A water-based epoxy resin cementing fluid system suitable for cementing was obtained in this article, which has good toughness and high strength, and can directly replace cement slurry for cementing. When the temperature was 50 °C and 70 °C, the fluidity of water-based epoxy resin cementing fluid system was greater than 18 cm, and the thickening time was 74 minute and 128 minute, respectively. The 28 day compressive strength of the resin cured at 70 °C increased by 276.3% and the tensile strength increased by 117.9% compared with the blank cement paste. Scanning electron microscope test indicated that the matrix of water-based epoxy resin is denser than that of blank cement paste. Fourier transform infrared spectrometer and X-ray diffraction analyses demonstrate that the cured epoxy resin products are not affected by curing age. According to the thermogravimetric results, epoxy resin can be used in high temperature deep well. On the whole, replacing cement with water-based epoxy resin cementing fluid can improve the cementing quality, which has broad application value. [ABSTRACT FROM AUTHOR]

The new period of science and technology implies control over the size and shape of materials. In determining the properties and potential application of materials the morphology variation plays an important role. The present study focuses on the fabrication of calcium oxalate (CaC2O4) in a nano range having uniform and novel particle morphology. The powder materials having monodispersed particles of plate-like and donut-shaped morphologies were successfully synthesized by a controlled precipitation method under extensively optimized experimental parameters. The morphology of the as-prepared uniform fine particle systems was studied by scanning electron microscope and the mechanical functional surface groups and crystallinity of the test material were examined by Fourier transform infrared spectroscopy (FT-IR) and (XRD) X-ray diffraction analysis, respectively. The effect of different parameters on calcium oxalate particle morphology was also investigated. The observed results explored a significant effect of technological parameters on particle size, shape, and uniformity. Therefore, monodispersed unique particle systems of calcium oxalate were synthesized under a narrow set of experimental conditions through a reproducible recipe protocol. [ABSTRACT FROM AUTHOR]

Hydraulic fracturing effectively enhances production in the unconventional oil and gas industry. As we all know, proppant plays a vital role in the hydraulic fracturing. In this paper, the effects of proppant type, particle size, concentration, closure pressure, and other factors are studied by laboratory experiments. Based on the actual triaxial simulation device (TSD), quartz sand, ceramic, and coated sand are used as proppant, while sandstone, coal rock, shale, and granite are selected as the stone slate to experiment. The surface of the proppant was imaged by a surface profiler (SP) and scanning electron microscope (SEM) to compare the microscopic surface characteristics before and after the experiment. The particle size macroscopic distribution was measured by Mastersizer 2000. The results and innovation are as follows: This paper investigates the proppant crushing for hydraulic fracturing and provides an alternative evaluation method for proppant selection. The crushing laws of proppant under different pressures and stone slate are compared by using the experimental device. It is reliable for quartz sand to replace ceramic in deep layer of the field application. It also overturns the previous thinking. We believe this found holds the key toward systematically optimizing the development of unconventional reservoirs. [ABSTRACT FROM AUTHOR]

Nanofluids have demonstrated incredible potential for application in various industries such as coolants. Metal oxides are widely used as solid particles in formulations of nanofluids due to their advantages. Metal oxide-based nanoparticles (NPs), ZnO NPs were fabricated by the ultrasonically assisted co-precipitation method. The structure and morphology of the synthesized ZnO NPs were characterized using an array of analytical techniques including X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The XRD results showed that the purity of ZnO was obtained. The investigated nanofluids remained stable for a long time without substantial sedimentation. The present study deals with the corrosion assessment of St37 steel in nanofluids prepared with various concentrations of ZnO NPs. A scanning electron microscope coupled with energy-dispersive X-ray spectroscopy was used to determine the surface characteristics and elemental composition of low-carbon steel specimens both before and after corrosion tests. Notably, the nanofluid containing 0.05% by weight of ZnO nanoparticles demonstrated the highest corrosion prevention efficiency among the prepared nanofluids. Furthermore, impedance spectroscopy measurements revealed that the corrosion resistance increased by 72.9% for the nanofluid containing 0.05 wt% ZnO NPs compared to the base fluid. These findings highlight the potential of ZnO nanoparticles as an environmentally friendly anti-corrosion compound in cooling systems, effectively reducing corrosion degradation. [ABSTRACT FROM AUTHOR]

A new species, Momonides neolandbergi Li & Guo sp. nov. is described in detail, which is the fifth species all over the world in Momonidinae Lundblad, 1941, Momoniidae K. Viets, 1926. The family and subfamily are newly recorded for Chinese fauna. The new species are recorded by camera, optical microscope, and scanning electron microscope. Publication:New species: [ABSTRACT FROM AUTHOR]

The current study demonstrates the effect of Ni-substitution on the structural, dielectric and ferroelectric properties of Ba0.90Sr0.10Ti1-xNixO3 (where x = 0.000, 0.005, 0.015 and 0.025) ceramics, synthesized by solid-state reaction approach. A pure perovskite phase with tetragonal structure has been confirmed by X-ray diffraction (XRD) analysis. Scanning electron microscope (SEM) images revealed change in microstructure. The dielectric behavior of the prepared ceramics was investigated as a function of temperature (30–150°C) at different frequencies. The results indicate that there is an increase in dielectric constant (ϵRT) and low dielectric loss (tanδRT) were obtained at room temperature by substitution of Ni2+ ions in BST ceramics, offering a promising material for capacitor applications at room temperature. Room temperature P-E loops were recorded at different applied electric fields and typical hysteresis loops were obtained. Improvement in the values of Pr and Pmax was observed by substitution of Ni2+ ions. [ABSTRACT FROM AUTHOR]

We present the results of the irreversibility field (Birr), critical temperature (Tc), and magnetic critical current density (Jcm) for cylindrical samples encapsulated in carbon and doped with 1-3 at% dysprosium and terbium oxides. All samples were analyzed microstructurally by using a scanning electron microscope (SEM) and X-ray diffraction (XRD). The influence of annealing temperature and time and high isostatic pressure on Jcm was investigated. Our results show that double-doped (C + Tb2O3 and C + Dy2O3) and low isostatic pressure heat treatment (0.1 MPa) decrease the Tc by about 0.5 K compared to the undoped MgB2 (0.1 MPa). The magnetic measurements show that double-doped and heat treatment under high isostatic pressure (HIP - 1 GPa) leads to a decrease in Tc of about 2.5 K compared to the undoped MgB2 sample after the HIP process. Our results show that the HIP process slightly increases Jcm at 4.2 K and 20 K, and improves Jcm at 30 K in undoped MgB2 samples. Furthermore, our results show that the HIP process and double-doped significantly increase Jcm at 4.2K and decrease Jcm at 30K. Our results indicate that the HIP process can produce high field and low-temperature pinning centers in doubly doped MgB2 materials. [ABSTRACT FROM AUTHOR]

A new Tulostoma species, T. irregulireticulatum is described. The genus Tulostoma is a gasteroid fungus in the family Agaricaceae and is commonly known as a stalked puffball. A detailed morphological description of this new taxon is provided, together with a map of the collection site, photographs of the macroscopic structures in the field, and images of microscopic structures under a light microscope and scanning electron microscope. [ABSTRACT FROM AUTHOR]

An economical 2Cr steel tubing was prepared for application in a certain downhole corrosion condition, and the CO2 corrosion behaviour was investigated by employing the 25Mn2 steel for comparative study. The corrosion films of the two steels under different corrosion conditions were analysed by optical microscope, scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). It is revealed that the corrosion rate of 25Mn2 steel at static solution is about 2.5 times higher than that at the dynamic solution with the flow velocity of 1 m/s, while the corrosion rate of 2Cr steel keeps almost the same. It is found that both steels show two layers of corrosion film at static corrosion, and the corrosion film is mainly composed of FeCO3, α-FeOOH and dotted Fe3C in the inner layer. It is inferred that carbon pickup phenomenon observed in the corrosion film is attributed to the formation of FeCO3, as well as may also be due to phenomenologically the reaction of Fe3C with carbonic acid. [ABSTRACT FROM AUTHOR]

This study investigates the optical and structural properties of nitrogen-doped Carbon Quantum Dots (NCQDs) on Titanium dioxide (TiO2). We synthesized the NCQDs via direct pyrolysis using varying amount of nitrogen precursor. We used a UV-visible, Fluorescence and Fourier Transform Infrared spectrophotometer, X-ray diffractometer (XRD), and Scanning Electron Microscope (SEM) to probe the samples. The introduction of nitrogen enhanced the intrinsic activities and electron dynamics of the CQD films, leading to improved confinement, charge extraction, and light harvesting. The optical response of the NCQDs strongly hinged on the nitrogen doping content. Sensitizing different amounts of NCQDs on TiO2 surface reduced their bandgap energies. XRD analysis confirms the preservation of the TiO2 anatase phase nanoparticle after the introduction of NCQDs, with no substantial changes to the crystal lattice and phase purity of the resulting photoanodes, indicating the presence of NCQDs on the surface. However, the deposition of NCQDs decreased the crystallite size. SEM images show well-dispersed morphologies with non-clustered NCQDs films. NCQDs can serve as promising photosensitizers in photovoltaic devices. [ABSTRACT FROM AUTHOR]

The surface-active ILs [C16mim]Cl synthesized by combining imidazole group (C4H6N2) and 1-chlorohexadecane (C16H33Cl) was used as surfactant to prepare ILs microemulsions for sludge treatment. Meanwhile, the treatment conditions were optimized and the optimal conditions were obtained. Due to the strong interaction between ILs and asphaltenes as well as the solubilization of microemulsions, the residual oil rate of oily sludge decreased to 1.33%. The characterization of oily sludge was performed by scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR) and contact angle measurement. Results showed that [C16mim]Cl ILs microemulsions treatment could effectively promoted the desorption of asphaltenes from the surface of sludge solids, which provided a clear understanding of the mechanism for ILs microemulsions-enhanced oily sludge recovery. Oil in Water (O/W) microemulsions prepared using ionic liquids [C16mim]Cl as surfactants were used to the treatment of oily sludge with high removal oil rate (97.97%) and low residual oil rate (1.33%). Based on the strong interaction between [C16mim]Cl and asphaltenes as well as the solubilization effect of microemulsions, the use of ionic liquids microemulsions improves the effect of sludge treatment and realizes the effective recovery of crude oil, which has potential applications in the field of energy recovery and environmental protection. [ABSTRACT FROM AUTHOR]

The solution-based casting method fabricates the free-standing pure PVDF-TrFE, PVDF-TrFE-Nafion blended films and tests them for structural, morphological, and microwave studies. The X-ray diffraction pattern and FTIR spectrum confirmed the formation of the ferroelectric β-phase of PVDF-TrFE. The surface morphology of blended films is studied by scanning electron microscope (SEM), and noticeable changes in the morphological features are observed in the blended films resulting from the differences in the nucleation process in these films. Then using the open-ended coaxial probe method, the complex permittivity measurements were carried out over a large frequency range, from 0.5 GHz to 50 GHz. These results were verified with the Transmission-Reflection method using a rectangular waveguide in the X-band and Ku-band frequency range. The microwave absorption properties of the blends are also studied in the same frequency range. The stability of the dielectric properties and low microwave absorption indicates that the blending of PVDF-TrFE with Nafion results in a new potential material for high frequency flexible capacitor applications. [ABSTRACT FROM AUTHOR]

We report the structure, microstructure, dielectric, transport, and optical properties of the CaMn0.94Ce0.06O3 ceramic synthesized by the solid-state reaction method. Analysis of the X-ray diffraction (XRD) pattern of the sample adopts an orthorhombic crystal symmetry. A study of scanning electron microscope (SEM) micrograph shows the homogeneous distribution of the well-grown grains over the entire surface of the sample. The well-defined and distinct grain boundaries surrounding the compact grains may be a possible reason for a better conductivity mechanism in the sample. The study of the energy dispersive x-ray (EDX) spectrum provides information about the formation of high-purity samples and also confirms the presence of Ca, Mn, Ce and O in both weight and atomic percentages. The agglomeration rate during the sintering process may be a possible reason for a better dielectric and conductivity mechanism. Fourier-transform infrared spectroscopy (FTIR) study strongly supports the presence of all constituent element's atomic vibration bands. The study of the UV visible spectra provides the idea of semiconducting nature and bandgap energy of 4.89 eV. At a low range of frequency, the presence of the Maxwell-Winger type of dielectric dispersion is confirmed. Dielectric properties were investigated, including conductivity, dielectric constant, dielectric loss, and complex modulus. According to impedance analysis, primarily the charge carriers' long-range movement controls the conduction process. The semiconducting nature of the sample is confirmed by analysis of the Cole-Cole plots. [ABSTRACT FROM AUTHOR]

We report the structure, microstructure, dielectric, and transport properties of the dysprosium (Dy) modified lanthanum bismuth oxide (LaBi0.85Dy0.15O3) synthesized by the solid-state reaction method. The Rietveld refinement of the X-ray diffraction (XRD) data was done using MAUD software which adopts an orthorhombic crystal system. Scherer's formula was used to calculate crystallite size, which is found to be 25.2 nm. An analysis of a scanning electron microscope (SEM) image indicates that the grains have an even distribution throughout the whole sample surface with well-defined grain boundaries. Once more, compacted grains and clearly defined grain boundaries may have an impact on the conduction mechanism in the sample. The energy dispersive analysis of the X-ray (EDX) spectrum provides that all the constituent elements are present in the both weight and atomic percentage in the sample. The generated sample appears to reflect the Maxwell–Wagner type of dielectric dispersion, in accordance with research on the dielectric characteristics as a function of temperature and frequency. While impedance evaluation confirms the existence of the negative temperature coefficient of resistance (NTCR), the modulus plot analysis indicates a non-Debye kind of relaxation mechanism. A thermally activated conduction mechanism is present, according to the study of the ac conductivity plot. Again, the study of the Nyquist and Cole–Cole plots shows that semiconducting behavior is consistent with several applications involving energy storage devices. [ABSTRACT FROM AUTHOR]

To investigate the impact of sodium dodecylbenzene sulfonate (SDBS) modification on coking coal’s wettability, our research focuses on coking coal and uses SDBS as the surfactant in the experiment. The surface tension, scanning electron microscope, FTIR, contact angle measurement, and reverse osmosis experiment are employed to measure the microscopic characteristics and wettability of raw coking coal, water-soaked coal, and coal soaked in 0.0005%, 0.005%, and 0.05% SDBS solutions. Finally, the dust reduction efficiency was determined by spray dust reduction experiments. We analyzed the effect of varying mass fractions of SDBS on coking coal’s wettability. The findings indicate that the surface of coal samples soaked in water and SDBS solution become rough. Adding clean water and SDBS solution improves the coal samples’ wettability. Among various coal samples soaked in different solutions, the one treated with 0.005% SDBS solution exhibits the smallest contact angle, significantly higher moisture absorption, and the most pronounced wetting effect. Soaking the coal samples in 0.005% SDBS solution can achieve the highest dust reduction efficiency. In summary, soaking the coal samples in no matter clean water or SDBS solution can enhance the wettability of coal dust, while soaking in 0.005% SDBS solution has a better effect. [ABSTRACT FROM AUTHOR]

In this paper, anthracite in Shanxi region is taken as a research object, and the pore structure of coal under different freeze-thaw times is characterized and analyzed by scanning electron microscope and nitrogen adsorption experiment. The SEM experimental results show that the micron-scale cracks on the surface of anthracite gradually connect after freeze-thaw, and the secondary crack channels are formed around the pores and air holes, so that the pores also begin to connect. Further, the quantitative information of the picture was extracted, and it was found that the surface porosity and fractal dimension of the coal sample changed significantly after three freeze-thaw cycles, which increased by 163.3% and 15.9% respectively, and increased with the increase of freeze-thaw cycles. The results of low-temperature nitrogen adsorption experiments show that the coal samples after freeze-thaw are mainly crack, and the pore structure changes from simple to complex. In addition, the maximum nitrogen adsorption capacity, specific surface area and pore volume increased by 125.7%, 69.3% and 72.6%, respectively. With the increase of freeze-thaw times, the growth rates of maximum nitrogen adsorption capacity, specific surface area and pore volume are significantly different. The results of joint characterization show that the number of pores and cracks increases to different degrees after freezing and thawing. Comparing the increase in the degree of fracturing (163.3%) with the increase in the total pore volume (30.68%), we find that the degree of change of the crack after thawing is higher than that of the pore. In this paper, the damage effect of coal samples after freezing and thawing with liquid nitrogen is investigated from an experimental point of view, which accelerates the great leap of cyclic cryogenic fracturing technology from basic theory to technical practice. [ABSTRACT FROM AUTHOR]

Modern scanning electron imaging (SEM) frequently adopts the multi-frame stacking technique to minimize the vibration and drift but ignores the electron beam-induced thermal effect (called thermal effect hereafter for short) during the stacking. This study investigates the thermal effect on SEM contrast in multi-frame stacking mode for two systems, namely one gold nanorod (Au-NR) and one silicon nanorod (Si-NR) on a Si substrate through a Monte-Carlo approach (In short, Au/Si and Si/Si systems). The primary focus of this investigation was to explore the correlation between two distinct types of signals, namely secondary electrons (SE) and backscattering electrons (BSE), in relation to the number of frames. It was observed that the SEM contrast exhibited sensitivity to the frame. The stacking process generally led to a reduction in SE contrast and an increase in BSE contrast compared to the scenario without thermal effects. This is attributed to higher heat accumulation within the solid as more frames are stacked, resulting in electrons from NRs acquiring extra energy and consequently causing a deep penetration depth that inhibits most SEs from being emitted. However, it helps BSEs to emit because there is more conversion of low-energy Ses into BSE signals with assistance from the extra energy. Furthermore, it was found that the thermal effect had less impact on cases involving a large primary electron (PE) beam energy. This is mainly because the larger initial energy causes the smaller relative variation in electron energy. Details of the explanation of the mechanism behind these results were given systematically by the electron-solid interaction theory. This study advances our comprehension and clarification of the physical mechanism underlying electron-beam-induced deposition, thereby enhancing process control, performance, and reliability. [ABSTRACT FROM AUTHOR]

The quality of water significantly affects the health and walefare of all orginisms, highlighting the importance to develop low-cost and efficient wastewater treatment methods. Herein, we report the fabrication, characterization, and utilization of a polymer-based ternary nanocomposite (CuO-SiO2/PVA) for the removal of Nile Blue (NB) and Methylene Blue (MB) contaminants from wastewater, along with exploring its potential biological activities. We have successfully employed the cost-effective sol--gel and in-situ polymerization approaches to fabricate the CuO-SiO2/PVA based ternary composite, utilizing Cu(NO3)2·3H2O:Glycerol:TEOS:PVA in a ratio of 8:2:3:4. The desired fabrication of nanocomposite was confirmed through UV-Visible spectroscopy, SEM (scanning electron microscope), TEM (transmission electron microscope), EDX (energy dispersive X-ray diffraction), FTIR (Fourier transform infrared), DSC (differential scanning calorimetry), and TGA (thermogravimetric analysis). In addition to its biological potentialthe performance of the nanocomposite in catalytic / photocatalytic removal of NB and MB dyes is investigated and compared. The higher photodegradation performance of the composite for NB (85%) dye than for MB (76%) dye indicates that variables such as chemical structure, charge, molecular mass, and pH sensitivity of the dyes can influence the catalyst's removal potential. This composite is considered to have a higher capability for removing pollutants and microorganisms from wastewater. [ABSTRACT FROM AUTHOR]

In this article, maleic anhydride (MA) was used to graft-modify chitosan (CS) to obtain maleic anhydride-modified chitosan (MCS). Composite films with different ratios were prepared by melt blending-extrusion pelletizing-blown film using Poly (butylene adipate-co-terephthalate) (PBAT) as the substrate and CS or MCS as the filler. These films can be utilized in a variety of ways, such as food packaging, agricultural mulching film, and more. The composite films were characterized and tested by a Fourier transform infrared (FTIR) spectrometer, thermogravimetric (TG) analysis, differential scanning calorimetry (DSC), scanning electron microscope (SEM), and electronic universal testing machine, and the effects of different fillers and filler contents on the properties of the composite films were investigated. The results showed that the thermal stability of the composite films decreased slightly with the increase in filler ratio, the melt crystallization temperature increased and then decreased, and the tensile strength and elongation at break of the composite films decreased. Compared with unmodified CS, MCS had better dispersion and compatibility when blended with PBAT, and the interaction between MCS and PBAT was greater than that of CS. The optimal filler amount of MCS was 6% for the combination of film material cost and performance considerations. [ABSTRACT FROM AUTHOR]

Based on polyvinyl alcohol, polyacrylic acid, and sodium alginate, ion-conducting hydrogels with high stretchability and adhesion were fabricated via a two-step process. Hydrogels were prepared with different contents of cellulose nanocrystals (CNC) and sodium alginate to improve the performance of ion-conducting hydrogels. The samples were tested and analyzed by Fourier transform infrared spectrometer, universal mechanical tester, LCR digital bridge and scanning electron microscope. The results show that the addition of sodium alginate can improve the ductility and mechanical properties of the hydrogel, and with the increase of the amount of sodium alginate, the ductility of the hydrogel shows an upward trend, when the amount of sodium alginate is 0 g, when the CNC is 0, the elongation at break of the hydrogel is 201.4%, and the maximum tensile strength is 0.045 MPa. When the amount of sodium alginate was 1 g and the CNC was 0, the elongation at break of the hydrogel was 769.2%, and the maximum tensile strength reached 0.075 MPa. The addition of CNC will also improve the mechanical properties of the hydrogel, but the addition of excessive CNC will reduce the mechanical properties of the hydrogel. When containing 2 g CNC and 1 g sodium alginate (SA), the elongation at break of the hydrogel was 983.2%, and the maximum tensile strength was 0.098 MPa. When the CNC content increased to 4 g, the elongation at break of the hydrogel decreased to 698.1%, and the maximum tensile strength decreased to 0.065 MPa. When the hydrogel is stretched, the relative resistance of the hydrogel increases with the stretching deformation. And the hydrogel can still guarantee the stability of the change in multiple stretching cycles, which indicates that the hydrogel has potential application value in flexible sensors. [ABSTRACT FROM AUTHOR]

This work examined the kinetics of Copper (II) and Lead (II) leaching in EDTA acid. The impacts of various factors such as pH, acid concentration, soil-to-solution ratio, and stirring speed were investigated to improve the leaching conditions and assess the leaching kinetics. According to the findings, copper (II) and lead (II) leaching was enhanced by an increase in leaching temperature, stirring speed and acid concentration, as well as a drop in solid-liquid ratio and pH. The results indicated that after 120 minutes of leaching in EDTA acid with a concentration of 1.5 M and a solid/liquid ratio of 5 g/200 mL, pH of 3, and stirring speed of 375 rpm, 90.98% of copper (II) and 95.43% of lead (II) were removed from the sample. Diffusion across the product layer was the rate-controlling phase during the leaching; according to the experimental results, a diffusion-controlled model best matched. The activation energy was determined to be 15.58 kJ/mol and 15.70 kJ/mol for copper (II) and lead (II), indicating the diffusion-controlled process. The ANN Multi-layer, Feed-forward, and Back-Propagation Learning algorithms are trained to optimize the leaching process parameters. The ANN algorithm was developed with two neurons as output layers corresponding to copper (II) and lead (II) leaching recovery, 15 hidden layers, and 5 input variables describing the leaching parameters. The optimal trained neural network illustrates the validation, testing, and training steps with R2 values of 0.992, 0.994 and 0.999, respectively. The leaching mechanism was validated by (XRF) X-Ray Fluorescence, (FTIR) infrared spectroscopy and (SEM) scanning electron microscope analysis of the original sample. [ABSTRACT FROM AUTHOR]

In this report, we are presenting the effect of B-site co-doping with Sn and Zr (2% each) on frequency and temperature-dependent dielectric and electrical properties of Ba0.5Sr0.5TiO3 (BST). The desired compound is synthesised following solid-state reaction route and the structural and micro-structural study of the resulting compound is done using X-ray diffractometer (XRD) and scanning electron microscope (SEM) technique. XRD study revealed that the parent structure of BST is mostly retained after co-doping. SEM micrograph analysis presented dense packing of grains of different sizes distributed all over the volume of compound formed. The compound was found to have a moderate value of dielectric constant and low tangent loss along with a near stable response of these dielectric properties over the studied frequency range, suggesting its possible application in tuneable matching networks and frequency agile antennas. Electrical properties study suggested a non-Debye type electrical response with a thermally activated conduction mechanism occurring in the material. The dependence of conductivity with temperature showed negative temperature coefficient of temperature behaviour of the compound and the ac conductivity spectrum followed Johnscher's power law. The variation of exponent with temperature suggested correlated barrier hopping conduction mechanism in the material. [ABSTRACT FROM AUTHOR]

The nanometer sodium montmorillonite (Na-MMT), hexadecyl trimethyl ammonium bromide (CTAB), and octadecyl trimethyl sodium chloride (OTAC) were used as reaction monomers and ethanol as solvent, and two oil soluble viscosity reducers MMT-CTAB and MMT-OTAC were synthesized. Structural characterization experiment of modified montmorillonite were conducted by the infrared spectrometer, thermogravimetric analyzer, contact angle tester, scanning electron microscope, and dispersion observation. 20 wt% wax-containing model oil was chosen as the research object. The properties of two viscosity reducers on the pour point and viscosity of model oil were studied experimentally. The results showed that the two modified montmorillonite viscosity reducers were successfully prepared. And both can reduce the pour point and viscosity of model oil. The performance of MMT-OTAC was better than MMT-CTAB, which can reduce the pour point of model oil by 6 °C and the viscosity by 91.1%. [ABSTRACT FROM AUTHOR]