This article presents the results of comparative investigations of thermal parameters of hybrid sol−gel coatings (named TMZ) prepared from tetraethyl orthosilicate and organically modified 3-methacryloxypropyltrimethoxysilane. The coatings were prepared with the addition of zirconium(IV) tetrapropoxide chelated with methacrylic acid. Two series of samples were investigated: the first series, TMZ-I, TMZ-II and TMZ-III, with different amounts of zirconium, and the second series, TMZ-I/Ce, TMZ-II/Ce and TMZ-III/Ce, with the addition of cerium nitrate. The influence of the amount of zirconium and cerium on the thermal parameters of the sol−gel coatings was next analyzed. Two non-destructive and photothermal techniques were used for this purpose: photothermal radiometry (PTR) and beam deflection spectroscopy (BDS). The thermal diffusivity and conductivity of the coatings were extracted from the frequency experiments and are presented and discussed. The two-layer model was applied to interpr... [more]

Two comb-type copolymers were synthesized by modifications of the maleic anhydride-α-octadecene copolymer with aniline (AMAC) and with phenethylamine (EMAC), respectively. The effects of AMAC and EMAC on the non-isothermal crystallization kinetics of the MEK−toluene dewaxing process were comparatively investigated. The results showed that, under the optimum process conditions, the addition of 100 ppm AMAC or EMAC could increase the yield of dewaxed oil (DWO) from 67.21% to 70.87% or 69.90%, respectively, and increase the filtration rate by 80% and 70%, respectively. The non-isothermal crystallization kinetics analysis showed that the crystallization process conformed to Mo’s equation, and the addition of AMAC and EMAC slowed down the crystallization rate of paraffin. The polarizing light microscope observations revealed that the addition of AMAC promoted the formation of snow flower-like crystals, and the EMAC addition led to the crystals having longer rods with a relatively complete m... [more]

Polymetallic transition metal phosphides (TMPs) exhibit quasi-metallic properties and a high electrical conductivity, making them attractive for high-performance hybrid supercapacitors (HSCs). Herein, a nanohoneycomb (NHC)-like FeNi layered double hydroxide (LDH) array was grown in situ on 3D current collector nickel foam (NF), which is also the nickel source during the hydrothermal process. By adjusting the amount of NaH2PO2, an incomplete phosphated FeNi(OH/P) nanosheet array was obtained. The optimized FeNi(OH/P) nanosheet array exhibited a high capacity up to 3.6 C cm−2 (408.3 mAh g−1) and an excellent long-term cycle performance (72.0% after 10,000 cycles), which was much better than FeNi LDH’s precursor. In addition, the hybrid supercapacitor (HSC) assembled with FeNi(OH/P) (cathode) and polypyrrole (PPy/C, anode) achieved an ultra-high energy density of 45 W h kg−1 at a power density of 581 W kg−1 and an excellent cycle stability (118.5%, 2000 cycles), indicating its great poten... [more]

Wettability alteration is one of the most important mechanisms of surfactant flooding. In this work, the combined Amott/USBM (United States Bureau of Mines) method was applied to study the average wettability alteration of initially neutral cores after viscoelastic-surfactant (VES) filtration. The effects of static aging, dynamic aging, VES concentration, filtration flow rate, and pore radius on the alteration of a core’s average wettability were studied. The wettability-alteration trends measured by Amott and USBM were consistent, demonstrating that the overall hydrophilicity of the core was enhanced after VES filtration. The wettability alterations of the core brought about by dynamic aging were more significant than by static aging. The viscoelastic properties of the VES played an important role in altering the wettability. In addition, the ability of the VES to affect the core’s wettability was significantly enhanced when the VES concentration was increased, which was beneficial in... [more]

We investigate proximity effects on hydrogen absorption in ultra-thin vanadium layers through combing light transmission and electron scattering. We compare the thermodynamic properties of the vanadium layers, which are based on the superlattice structure of Cr/V (001) and Fe/V (001). We find an influence of the proximity effects on the finite-size scaling of the critical temperatures, which can be explained by a variation of dead layers in the vanadium. In addition to this, the proximity effects on hydrogen absorption are also verified from the changes of excess resistivity.

High mineralization of water complicates the use of foam in reservoir conditions. Anionic−nonionic surfactants are one of the best candidates for these conditions since they have both high surface activity and salt tolerance. One of the ways to obtain anionic−nonionic surfactants is to modify nonionic surfactants by an anionic group. The type of the group and its chemical structure can strongly affect the properties of the surfactant. In this work, widely-produced nonionic surfactant nonylphenol (12) ethoxylate (NP12EO) was modified by new types of carboxylic groups through the implementation of maleic (NP12EO-MA) and succinic (NP12EO-SA) anhydrides with different saturation levels. The main objectives of this work were to compare synthesized surfactants with nonionic precursor and to reveal the influence of unsaturated bonds in the carboxyl group on the properties of the foam. NaCl concentration up to 20 wt% was used to simulate high mineralization conditions, as well as to assess the... [more]

In this paper, a layer-by-layer removal model of surface atoms (Al) is established according to the atomic structure of sapphire, which can accurately calculate etch rates of crystal planes and analyze the anisotropy of etch rates of sapphire. Firstly, etch rate distributions of sapphire are gained through different etching experiments of sapphire hemispheres, and the effect of concentrations of the etching solution on etch rate distributions are analyzed. Then, different types of surface atoms are classified based on the types of chemical bonds of surface atoms, the arrangement laws of surface atoms of different crystal planes are analyzed and a general formula for calculating etch rates of different planes is proposed. Finally, the effectiveness of the layer-by-layer removal model of surface atoms (Al) is proved by small errors between calculated rates of the model and experimental rates at different concentrations, and the factors affecting the anisotropy of etch rates of sapphire a... [more]

This paper presents the results of studies for niobium sorption from chloride solutions with the use of anion-exchange organic sorbents: Amberlite IRA-67, Purolite A-100, AB-17-8, and AN-2FN. Niobium sorption was performed from model niobium-containing solutions. Data on comparative sorption characteristics of the studied sorbents were obtained, and the static exchange capacity of the sorbents, values of distribution coefficients, and extraction degree during the niobium sorption from chloride solutions were calculated. The Purolite A-100 anion-exchange resin exhibited the highest affinity for niobium ions under the conditions studied. Its distribution coefficient was 184 mL/g; the niobium extraction degree was 41.5%. To study the equilibrium sorption of niobium from solution on the Purolite A-100 anionite, three well-known models of isotherms were applied: Langmuir, Freundlich, and Dubinin−Radushkevich. The data obtained confirm the good agreement of the Langmuir model with the result... [more]

Aluminium metal is not typically added to the submerged arc welding (SAW) process because it is easily oxidised to form unwanted slag in the weld pool. The successful application of aluminium as a de-oxidiser is illustrated in this study by preventing oxidation of Cr and Co to their oxides, thereby preventing element loss to the slag. Unconstrained pure metals of Al, Cr, Co and Cu were applied to investigate the gas formation behaviour of these elements in the SAW arc cavity. Of interest is the effect of copper in the arc cavity in terms of its possible substitution for aluminium. The results confirmed that the Al-Cr-Co-Cu alloyed weld metal total oxygen content was lowered to 176 ppm O, in comparison to 499 ppm O in the weld metal formed from welding with the original flux, which excluded metal powder additions. This lower ppm O value of 176 ppm O confirms that the added aluminium powder effectively lowered the original flux-induced partial oxygen pressure in the arc cavity, and at th... [more]

The examination and choice of an alternate composite material for the high-voltage circuit of Otto cycle internal combustion engines—more commonly known as gasoline engines—are presented in the research that follows. To do this, multicriteria selection procedures are employed, and the outcomes are validated through the use of thermal character simulation software and standard laboratory tests. Nylon is the recommended material for Coils on Plug (COP) high-voltage insulators. Four of the six multicriteria selection techniques utilized in this study were found to be effective. It was discovered through the virtual simulation process that, even in the same environment with the same edge circumstances, the thermal behavior of the materials differs dramatically because the quadrants exhibit different behavior depending on the material. Given that nylon has a lower elasticity modulus than silicone, it was determined that the dimensions are crucial for the nylon Spark Plug Boot (SPB) to compl... [more]

Bioethanol produced from lignocellulose is a renewable energy substitute for traditional fossil fuels. Poplar wood as forest waste is popular in bioethanol production. Nonetheless, the complex structure of lignocellulose leads to low reducing sugar and ethanol yields. Thus, lignocellulose pretreatment is necessary to promote enzymatic hydrolysis. Deep eutectic solvents (DESs) have good dissolution capacity, low vapor pressure, a simple synthesis procedure, low synthesis cost and low toxicity. More and more researchers have begun paying attention to the application of DESs in lignocellulose pretreatment. In this work, poplar wood was pretreated using a series of basic DESs based on diol. The effects of the DES species, the basicity of the solvents, the pretreatment temperature and the pretreatment time on the effectiveness of pretreatment and enzyme hydrolysis for poplar wood were investigated, and characterization analysis (Fourier transform infrared spectroscopy, X-ray diffraction and... [more]

Multiple Automated Guided Vehicles promise to be an effective solution for executing tasks such as material transportation and inspection in industrial parks. In particular, system stability is the key to maintaining connectivity among multiple agents. In this paper, we build the stability model of multi-agent system (MAS) under the background of swarm robots transporting materials in an industrial park, and propose a network topology optimization method to improve the stability of MAS. In concrete, we first analyze the effect of channel environment on network topology, and the communication delay is analyzed. Then considering the communication delay and artificial potential field, we establish the stability analysis model of MAS and obtain the stability condition of the MAS by using Lyapunov correlation theorem. Finally, we formulate the network topology optimization problem of MAS by maximizing the second smallest eigenvalue of the Laplacian and get the optimal solutions. Analysis an... [more]

The demand to synthesize economical detoxification adsorbents of organic pollutants has been a thriving solicitude for most environmental research aspirants. Here, we synthesized a titanium(III) oxide doped with spherical shaped meta-aminophenol formaldehyde magnetic microspheres (Ti2O3/mAPF MMSs) by the polymerization method of Ti2O3 nanoparticles with formaldehyde and m-aminophenol. SEM analysis confirmed the synthesized material as crystalline in nature and had ~400−450 nm sized particles. The physical characterization of the Ti2O3/mAPF MMSs were quantitatively revealed by FTIR spectrum and PXRD in elaboration. The carboxylate frequency and the characteristic apex of the titanium−oxygen bond was found in the FTIR spectrum for Ti2O3/mAPF derived from Ti2O3. The PXRD patterns proved that the synthesized magnetic microspheres contained Ti2O3 nanoparticles. The experimental methods of TGA and DTA confirmed the thermal stability and its composition of Ti2O3/mAPF MMSs. The kinetic adsorpt... [more]

Single-particle inductively coupled plasma-mass spectrometry (SP-ICP-MS) has emerged as an important tool for the characterization of inorganic nanoparticles (NPs) in the environment. Although most SP-ICP-MS applications rely on the quadrupole ICP-MS (ICP-QMS), it is limited by the slow scanning speed of the quadrupole. Recent advancements in instrumentation have led to the development of inductively coupled plasma time-of-flight mass spectrometry (ICP-TOF-MS) which offers a viable solution. In this review, we discuss the recent advances in instrumentation and methodology of ICP-TOF-MS, followed by a detailed discussion of the applications of SP-ICP-TOFMS in analyzing NPs in the environment. SP-ICP-TOFMS has the potential to identify and quantify both anthropogenic and natural NPs in the environment, providing valuable insights into their occurrence, fate, behavior, and potential environmental risks.

This work focused on the insufficient or excessive pressure relief in large-diameter pressure relief by drilling. The influence of large-diameter pressure relief by drilling on the 6307 working face of the Tangkou coal mine on the roadway deformation was taken as the research background, with numerical simulations, indoor experiments, and on-site applications used. The influence of pressure relief drilling on roadway deformation was studied to propose segmented reaming pressure relief. The influences of parameters (e.g., reaming diameter, reaming depth, and borehole spacings) on the evolution characteristics of segmented reaming cracks and pressure relief were further investigated. The results showed that segmented reaming pressure relief reduced the roadway deformation and the peak elastic energy of coal in the impacted hazard area and improved the energy accumulation of the surrounding rocks of the roadway. The effect of segmented reaming pressure relief was positively correlated wit... [more]

Chinalco’s Toromocho mine, located in the Morococha district of Peru, treated 117,200 mtpd ores during last 10 years. It is currently undergoing expansion, treating approximately 52,740 mtpd of chalcopyrite ore since 2021. As with the commissioning of most large plants, the metallurgical performance levels produced after stability was achieved were below the design criteria; more specifically, the Cu overall recoveries were 80−82% compared with the design value of 85%, and the final concentrate Cu grades were 20−23% compared with the design value of 24% over the past 2 years. It is clear that the copper losses in the fine size fraction (<10 µm) were due to unoptimized hydrodynamics. To overcome this obstacle and improve overall performance, an innovative approach for flotation circuit evaluation was designed and set up, to improve understanding of the nature of the mineral losses, benchmark the cell hydrodynamics as a platform to improve flotation cell operation, and link the circui... [more]

The processing quality of steel bar thread has a large influence on its performance. Using the traditional thread processing technology, it is difficult to meet the requirements of steel bar thread processing with large diameter and high strength. A technical process for HRB500 high-strength steel bar thread processing, including face milling, rib stripping, chamfering, necking formation, and thread rolling, was proposed. The influences of cutting parameters on the cutting force of steel bar surface in face milling were analyzed by the finite element method. For the necking formation process, the effect of springback amount on necking formation was studied. The main parameters in rolling formation were analyzed and calculated, including extrusion pressure, rolling speed, and rolling feed. Experiments for uniaxial tensile of the processed high-strength steel bar threads were carried out. The results showed that cutting depth has the largest influence on the cutting force; the second is... [more]

Four different bacteria capable of degrading butachlor, as well as five different syntrophic pairs of bacteria able to break down butachlor, were isolated from rice paddy soils in Korea. Genetic and phenotypic analyses were conducted to better understand their characteristics and behavior. All single isolates and syntrophic pairs were able to utilize butachlor as a sole carbon and energy source. Analysis of the 16S rRNA sequence showed that the isolates were related to members of the genus Rhodococcus and a new type of butachlor-degrading genus Sphingobium. The chromosomal DNA fingerprinting patterns of the butachlor-degrading bacteria and syntrophic pairs were analyzed using a technique called repetitive-sequence-based PCR (REP-PCR). The results showed that there were two different REP-PCR patterns found among the four independent butachlor-degrading bacteria, and ten strains of five different syntrophic pairs produced a total of eight distinct DNA fingerprints. Through the use of gas... [more]

Design parameters such as initial bonding section, prestress, and bonding stiffness have a significant impact on the mechanical properties of the full-length bonded prestressed bolt. In order to understand the influence of the above three parameters on the axial force and shear stress of anchor bolts under the condition of rock separation, theoretical and numerical models were established, and the sensitivity of different parameters was analyzed based on the grey correlation method. Results indicate that the bonding stiffness had the greatest impact on the mechanical properties of the bolt and largely determined the peak axial force, peak interfacial shear stress, and number of sliding elements. Moreover, prestress had a significant impact on the peak axial force and the distribution of shear stress in the initial bonding section, while the length of the initial bonding section had a significant impact on the number of sliding elements and the peak axial force after sliding. The grey c... [more]

Composites of (1-x)Gd2Zr2O7·xMgO were prepared by mixing gadolinium zirconate with freshly precipitated Mg(OH)2 followed by heat treatment at 1500 °C. Small concentrations of magnesium oxide dissolved in the complex oxide matrix of Gd2Zr2O7. This led to decrease in the lattice parameters of the matrix phase and a complex redistribution of Gd and Zr over the A and B sublattices. According to the impedance spectroscopy results of the studied samples, for (1-x)Gd2Zr2O7·xMgO (x = 0.05, 0.07, 0.10), the ionic conductivity was slightly higher than that for the undoped Gd2Zr2O7. The share of dominant ion transport did not change upon doping with magnesium oxide. The composites showed chemical resistance in a lithium halide (LiCl) melt and interacted with LiCl-xLi2O (x = 2 wt.%, 4 wt.%) melts at 650 °C with the formation of a Gd2O3 phase or a mixture of phases (Gd2O3, Li2ZrO3, ZrO2, LiGdO2, or LiGdCl2) on the ceramic surface, respectively.

Gas electron multipliers (GEMs) have been widely used for particle collection and signal amplification. Because of the advantages of glass, such as high hardness, aging resistance, and dielectric strength, research into its application as a substrate material in GEM design and process has attracted extensive attention in recent years. This paper compares two commonly used glass GEM structural designs and shows that the optical transparency of the hexagonal symmetric structure is superior to that of the rectangle structure. An electric field model is developed to characterize the negative correlation between the hole diameter and the electric field strength. The structure of glass GEM is designed according to the feasibility of the process. A new process method of surface metal patterning using hole filling to form a mask is proposed, which can meet the high alignment and shaping requirements of the perfect match between the opening of metal layer and the aperture shape of the substrate... [more]

By adjusting the synthesis process, silver nanoparticles (AgNp) of various shapes, sizes, and structures can be obtained, all of which have a substantial impact on the biological effect, notably, the regulation of antibacterial activity in the present circumstances of growing bacterial resistance. Due to their relatively small size, nanoparticles may be disseminated evenly throughout the body of the experimental animal, even at low doses, and exert more potent antibacterial activities. Our research was centered on the synthesis, production, and biological evaluation of antibacterial silver nanoparticles. Using the Turkevich method, we were able to effectively synthesize and characterize nanoscale silver particles, with an average crystallite size of 9.49 nm. We examined their acute toxicity and pharmacokinetic characteristics in rats after administering a single dosage. In addition, we evaluated the biological effect of topical AgNp suspension on the progression of burn-type lesions in... [more]

Efficient waste management, especially in relation to swaste reuse, has become a pressing societal issue. The waste bittern generated during salt production and discarded oyster shells present formidable environmental challenges and a waste of resources for some coastal regions. Therefore, this work developed a two-stage circular process for the environmentally friendly and efficient utilization of both waste materials. In the first stage, CO2 gas and an organic extraction phase comprising Tri(octyl-decyl)amine (R3N) and isoamyl alcohol were introduced into the waste bittern to obtain MgCO3·3H2O (s). The second stage involved reacting the reacted organic extraction phase with oyster shell powders to produce CaCl2·2H2O (s) and CO2 (g) and regenerate R3N. This work focused on investigating the yield of MgCO3·3H2O and the regeneration ratio of R3N, which are crucial indicators for the two stages involved in the process. The results indicate that, under optimal operating conditions, a maxi... [more]

To handle the gangue well and control the settlement of the surface, as well as to reduce the risk of water bleeding, settlement and even blockage and pipe breaking of the gangue slurry in the process of conveying, the rheological characteristics of the slurry should be studied. The rheological properties of slurry with different concentrations prepared from gangue samples of the Ningtiaota coal mine were tested, and the correlation between the rheological characteristics of the coal gangue filling slurry and three factors, namely the gangue mass fraction, grain gradation and standing time, were studied by a single factor method and response surface methodology. The results show that the fitting curve of the Herschel−Bulkley model is mostly linear, that is, the shear stress of coal gangue paste increases as a function of the shear rate. Therefore, these two concentrations are too small to form a stable network structure to wrap large particles and can easily cause pipe blockage. The yi... [more]

The evaluation of groundwater environmental quality and the identification of recharge sources are very important for groundwater utilization. In this study, hydrochemistry and isotope analysis methods are used to investigate the recharge sources and hydrochemical processes of groundwater in Zhanjiang City. The results show that all samples of groundwater were drawn on the left of the global meteoric water line (GMWL: δD = 8δ18O + 10) and local meteorological water lines (LMWL1: δD = 8.17δ18O + 11.74 and LMWL2: δD = 7.50δ18O + 6.18), indicating that the groundwater was mainly recharged by meteoric precipitation and influenced by the effect of evaporation. In the middle and deep confined aquifers, the isotope data depleted with the depth, indicating that there is a relatively weak hydraulic connection between them. In addition, compared with unconfined groundwater, the isotope data of confined groundwater showed relative depletion, indicating that the confined aquifer may be partially r... [more]