Providing real-time information on the chemical properties of hydrocracking bottom oil (HBO) as the feedstock for ethylene cracker while minimizing processing time, is important to improve the real-time optimization of ethylene production. In this study, a novel approach for estimating the properties of HBO samples was developed on the basis of near-infrared (NIR) spectra. The main noise and extreme samples in the spectral data were removed by combining discrete wavelet transform with principal component analysis and Hotelling’s T2 test. Kernel partial least squares (KPLS) regression was utilized to account for the nonlinearities between NIR data and the chemical properties of HBO. Compared with the principal component regression, partial least squares regression, and artificial neural network, the KPLS model had a better performance of obtaining acceptable values of root mean square error of prediction (RMSEP) and mean absolute relative error (MARE). All RMSEP and MARE values of densi... [more]

When it comes to lightweight design of automotive wheels, hybrid designs consisting of a carbon composite wheel rim and a metallic, e.g., aluminum alloy, wheel disc offer significant potential. However, the conventionally used bolted joint between the two parts is complex and requires compromises in lightweight design due to the additional mechanical elements. Within this research, an adhesive joint for a hybrid wheel is developed in order to demonstrate its performance and lightweight potential. The main challenges are the reliable resistance against high structural loads during different load cases, as well as the residual stresses in the joint due to different thermal expansion rates of the composite and aluminum material. The developed joint combines an adhesive bond with a form-fitted geometry while still enabling an assembling process of the wheel disc in rotational direction. In addition, adaptations of the fiber layup in the rim area significantly reduce the thermal residual st... [more]

The chemical industry includes a wide range of factories focused on obtaining final products as: (i) plastics; (ii) chemical fibers; (iii) rubber; (iv) perfumery and cosmetic products; and (v) cleaning products. Although the level of safety in the activities and installations of this sector is very high, the use of dangerous substances implies an increased risk of suffering an accident involving the emission of hazardous substances, as well as endangering the safety of workers. In the case of the manufacture of softeners, the presence of isopropanol (C3H8O), and dimethyl sulfate (CH3)2SO4), have been reported to be the accident cause in most of the cases. The European accident database (eMars) reported an accident in which the presence of impurities of nickel (Ni) in the hydrogenated tallow used as raw material for softener production may have increased thermal reactivity and the chances of spontaneous combustion. This paper analyzes the results obtained with the Maciejasz Index (MI) t... [more]

Since the 1950s, plastic production has skyrocketed. Various environmental and human activities are leading to the formation and accumulation of microplastics (MPs) in aquatic and terrestrial ecosystems, causing detrimental effects on water, soil, plants, and living creatures. Wastewater treatment plants (WWTPs) are one of the primary MP management centers meant to check their entry into the natural systems. However, there are considerable limitations in effectively capturing, detecting, and characterizing these MPs in the inlet and outlet of WWTPs leading to “unaccounted MPs” that are eventually discharged into our ecosystems. In order to assess the holistic picture of the MPs’ distribution in the ecosystems, prevent the release of these omitted MPs into the environment, and formulate regulatory policies, it is vital to develop protocols that can be standardized across the globe to accurately detect and account for MPs in different sample types. This review will cover the details of c... [more]

This study aimed to purify and partially characterize a keratinolytic protease produced by Bacillus sp. P45 through bioconversion of feather meal. Crude protease extract was purified using a sequence of an aqueous two-phase system (ATPS) in large volume systems (10, 50, and 500 g) to increase obtaining purified enzyme, followed by a diafiltration (DF) step. Purified protease was characterized in terms of protein profile analysis by SDS-PAGE, optimum temperature and pH, thermal deactivation kinetics at different temperatures and pH, and performance in the presence of several salts (NaCl, CaCl2, MnCl2, CaO, C8H5KO4, MgSO4, CuSO4, ZnSO4, and FeCl3) and organic solvents (acetone, ethanol, methanol, acetic acid, diethyl ether, and formaldehyde). ATPS with high capacities resulted in purer protease extract without compromising purity and yields, reaching a purification factor up to 2.6-fold and 6.7-fold in first and second ATPS, respectively, and 4.0-fold in the DF process. Recoveries were u... [more]

Aim: To formulate and characterize a palm-oil-in-water-based α-Mangostin nano-emulsion (PO-AMNE) endodontic irrigant, in order to evaluate its antibacterial efficacy against Enterococcus faecalis, Staphylococcus epidermidis, and Candida albicans biofilms, as well as its capacity to remove smear layer. Methods: The solubility of α-Mangostin in various oils was determined and selected, surfactants and co-surfactants were used for the nano-emulsion trial. PO-AMNE was prepared and optimized. The MIC was performed, and the antimicrobial efficacy was estimated against biofilms. The optimized 0.2% PO-AMNE irrigant antimicrobial efficacy in a tooth model was done using colony-forming units. The treated teeth were processed by scanning electron microscopic examination for debris and smear layer removal. An Alamar Blue assay was used to evaluate cell viability. The optimization of the PO-AMNE irrigant was performed using Box−Behnken statistical design. Results: The optimized 0.2% PO-AMNE irrigan... [more]

Since the requirement for a material cutting process occurs in a wide variety of applied contemporary manufacturing, the cutting stock problem plays a critical role in optimizing the amount of raw material utilized in everyday production operations. In this paper, we address the two-dimension strip-cutting problem and implement the graph compression technique to improve the performance of the arc-flow formulation. The number of variables of the obtained mathematical model are substantially reduced. A comparative study on a large set of benchmark instances shows that our compressed model yields very good results for the non-unitary item demand case in contrast to the state-of-the-art mathematical models. Moreover, improved bounds are provided for 24 unsolved benchmark instances, among which 8 have been solved to optimality.

Dyes used in textiles, foods, cosmetics, and chemicals have become a major environmental pollution issue around the world. To address this issue, a number of technologies have been created to remove these pollutants from the environment. Due to their superior properties at nanoscale, numerous nanomaterials have been applied to remove dyes from polluted waters. This research presents the findings of the development of bentonite nano zero-valent iron (B-nZVI) for the treatment of synthetic cationic dyes. This study has three objectives: (i) to produce bentonite nano zero-valence iron (B-nZVI), (ii) to characterize its adsorbents (B-nZVI), (iii) to characterize its adsorption capacity. Four main tests were used for this purpose: (i) a physical test (Brunauer−Emmett−Teller (BET) surface area), (ii) a chemical test (cation exchange capacity (CEC) and X-ray fluorescence (XRF)), (iii) morphology (field emission scanning electron microscopy (FESEM) and (iv) mineralogy (Fourier transform infrar... [more]

Acoustic emission (AE) technology has the advantage of online localization to study the change laws of AE in the process of coal spontaneous combustion and to reveal the generation mechanisms of AE signal during the process of heating and rupture of coal body from a microscopic perspective. This paper first constructs a large-scale coal spontaneous combustion AE test system and conducts experimental tests on the AE signal in the process of coal spontaneous combustion. The results show that with the increase of temperature in the process of coal spontaneous combustion, the AE signal shows a trend of increasing fluctuations. Low-temperature nitrogen adsorption experiments studied the pore structure of coal spontaneous combustion, and the results showed a correspondence between the development of pores and the temperature of coal spontaneous combustion. Further, through the analysis of the evolution of the pore structure of coal through Fourier transform and fractal theory, it is found th... [more]

We investigated the effect of electro-induced multi-gas modification (EIMGM) duration on the adhesion and wear resistance of PET and LDPE polymer substrates used in the printing industry. It was found that EIMGM increases the polar component and the complete free surface energy from 26 to 57 mJ/m2 for LDPE and from 37 to 67 mJ/m2 for PET (due to the formation of oxygen-containing groups on the surface of the materials). Although the degree of textural and morphological heterogeneity of the modified LDPE increased more than twice compared to the initial state, it is not still suitable for application as a substrate in extrusion 3D printing. However, for PET, the plasma-chemical modification contributed to a significant increase (~5 times) in filament adhesion to its surface (due to chemical and morphological transformations of the surface layers) which allows for using the FFF technology for additive prototyping on the modified PET-substrates.

In recent years, China has entered a period of rapid urban development, but most of the cities with rapid development still have ground hardening, which makes it difficult for rainwater to penetrate and discharge. In order to achieve the rapid drainage of accumulated water in the city, nanotechnology was introduced, and permeable concrete based on NC and NS nanomaterials was proposed. Combined with finite element analysis, the permeable properties and mechanical properties of permeable concrete mixed with nanomaterials were analyzed. A comprehensive performance analysis of pervious concrete shows that the viscosity of permeable concrete mixed with nanomaterials is significantly higher than that of non-mixed pervious concrete, and the permeability coefficient of permeable concrete mixed with nanomaterials can reach 0.43 cm/s. A finite element analysis shows that the incorporation of nanomaterials can improve the compressive strength of permeable concrete. At the same time, under a rainw... [more]

Sodium-ion batteries (SIBs) serve as the most promising next-generation commercial batteries besides lithium-ion batteries (LIBs). Hard carbon (HC) from renewable biomass resources is the most commonly used anode material in SIBs. In this contribution, we present a review of the latest progress in the conversion of waste biomass to HC materials, and highlight their application in SIBs. Specifically, the following topics are discussed in the review: (1) the mechanism of sodium-ion storage in HC, (2) the HC precursor’s sources, (3) the processing methods and conditions of the HCs production, (4) the impact of the biomass types and carbonization temperature on the carbon structure, and (5) the effect of various carbon structures on electrochemical performance. Data from various publications have been analyzed to uncover the relationship between the processing conditions of biomass and the resulting structure of the final HC product, as well as its electrochemical performance. Our results... [more]

Resilience is regarded as an essential design objective of a wide range of systems in modern society. This work is based on a vision that networks of mobile energy storage systems could provide an alternative off-grid power system design for rural and underdeveloped regions. To evaluate the resiliency of networked energy storage systems under overload failure, a model of concurrent cascading failure and healing processes is developed and demonstrated. Two resilience metrics are used to evaluate the resilience of a real-world network, namely the recovery level at a specified time and the recovery time. The simulations generate system trajectories at each time step. We explore the dependence of the system behavior on different model parameters that capture key recovery strategies. The success probability of the recovery of a failed node needs to be high enough for the network to restore its original functionality. Similarly, the increase in recovery budget parameter also leads to faster... [more]

Fast-growing grass is a biomass material with characteristics such as high temperature and drought resistance; rapid growth and development; and repeated germination and cutting. Therefore, it is a popular biomass fuel. It is required that the pollutants produced during the biomass combustion process are appropriately controlled. For this purpose, our study analyses the influence of combustion temperature and calcium oxide (CaO) on the nitrogen oxides (NOx) and carbon monoxide (CO) emission characteristics of fast-growing grass combustion using the biomass combustion flue gas analysis and testing platform. The results of our analysis revealed that CaO additive can simultaneously reduce the peak and total NOx emissions at 750 °C. Particularly, 5% CaO demonstrated a significant control effect on the NOx emission from the fast-growing grass combustion process, with a peak and total emissions reduction of 47.05% and 56.81%, respectively. In addition, with an increase in temperature, the CO... [more]

Antibiotic pollution has become a serious concern due to the extensive use of antibiotics, their resistance to removal, and their detrimental effects on aquatic habitats and humans. Hence, developing an efficient antibiotic removal process for aqueous solutions has become vital. Amoxicillin (Amox) is one of the antibiotics that has been efficiently removed from an aqueous solution using hydroxyapatite nanoparticles (HAP NPs). The current study synthesizes and utilizes hydroxyapatite nanoparticles as a cost-effective adsorbent. Adsorbent dose, pH solution, initial Amox concentration, equilibrium time, and temperature are among the factors that have an evident impact on Amox antibiotic adsorption. The (200) mg dose, pH (5), temperature (25) °C, and time (120) min are shown to be the best-optimized values. The nonlinear Langmuir’s isotherm and pseudo-second-order kinetic models with equilibrium capacities of 4.01 mg/g are highly compatible with the experimental adsorption data. The experi... [more]

Biocatalysis entails the use of enzymes, which are catalytically active proteins, to speed up reactions so that products can be obtained swiftly and accurately [...]

To improve the understanding of the mixing performance of double shaft, batch-type paddle mixers, the discrete element method (DEM) in combination with a Plackett−Burman design of experiments simulation plan is used to identify factor significance on the system’s mixing performance. Effects of several factors, including three material properties (particle size, particle density and composition), three operational conditions (initial filling pattern, fill level and impeller rotational speed) and three geometric parameters (paddle size, paddle angle and paddle number), were quantitatively investigated using the relative standard deviation (RSD). Four key performance indicators (KPIs), namely the mixing quality, mixing time, average mixing power and energy required to reach a steady state, were defined to evaluate the performance of the double paddle mixer. The results show that the material property effects are not as significant as those of the operational conditions and geometric param... [more]

Optimizing coal blending is important for high-quality development of coking industries, among which deep understanding of relationships between coal characteristics and coke quality is critical. This work selected four typical coals from Shanxi Province in China to investigate influences of their structures and properties on coke quality. Although these samples belong to coking coals, the mechanical strength and thermal strength of the corresponding cokes are quite different. Macerals in coals, especially vitrinite, have significant effect on thermal strength of cokes. The thermal strength of coke B is better than coke A, because coal A mainly contains desmocollinite and coal B has more telocollinite. The CSR of coke B, C and D is higher than 60%, indicating they possess good thermal property. In the coking process, relatively low initial softening temperature (100 °C), smooth fluidity region and appropriate maximum fluidity is helpful to improve coke quality based on Gieseler fluidit... [more]

Commercially pure aluminium is employed in several industrial applications. On some applications, the surface of this material needs to be functionalised. Laser surface texturing is a powerful tool to functionalise aluminium and aluminium alloy surfaces. However, the corrosion resistance of the laser textured aluminium alloy can be modified, and this has rarely been investigated in the literature. Consequently, the corrosion resistance of the laser textured commercially pure aluminium in saltwater was evaluated using several electrochemical techniques: asymmetric electrochemical noise, potentiodynamic polarisation curve and electrochemical impedance spectroscopy. Although the non-laser surface textured samples possessed higher kinetic corrosion resistance in the first hours of immersion, the corrosion mechanism (process group of the corrosion) was found to be more unstable than the laser textured specimens. The oxidised layer of the textured samples was also nobler than the native pass... [more]

This study proposes a simple correlation for approximating hydrogen solubility in biomaterials as a function of pressure and temperature. The pre-exponential term of the proposed model linearly relates to the pressure, whereas the exponential term is merely a function of temperature. The differential evolution (DE) optimization algorithm helps adjust three unknown coefficients of the correlation. The proposed model estimates 134 literature data points for the hydrogen solubility in biomaterials with an excellent absolute average relative deviation (AARD) of 3.02% and a coefficient of determination (R) of 0.99815. Comparing analysis justifies that the developed correlation has higher accuracy than the multilayer perceptron artificial neural network (MLP-ANN) with the same number of adjustable parameters. Comparing analysis justifies that the Arrhenius-type correlation not only needs lower computational effort, it also has higher accuracy than the PR (Peng-Robinson), PC-SAFT (perturbed-c... [more]

Ugi reactions have been widely studied due to their mild reaction conditions, high structural variability, and wide applications. Ugi adducts have proved to be highly efficient for different kinds of post-transformations by carefully choosing the starting four components. Considering the importance of polycycles, diverse post-Ugi transformations have been employed for the construction of structurally novel polycyclic N-heterocycles. This minireview summarizes the recent developments of post-Ugi reactions for the synthesis of polycycles after the year 2019. Through transition metal catalysis from gold, rhodium, silver, copper, and palladium, as well as transition metal-free approaches, versatile polycycles are constructed in a highly efficient and step-economical manner.

In shale oil reservoirs, nano-scale pores and micro-scale fractures serve as the primary fluid storage and migration space, while the associated flow mechanism remains vague and is hard to understand. In this research, a three-dimensional (3D) reconstruction of the shale core and micro-pore structure description technique is established; digital core technology for shale reservoirs was developed using X-ray computed tomography (X-CT), scanning electron microscope (SEM) and a focused ion beam scanning electron microscope (FIB-SEM). Microscopic oil−water two-phase flow is mimicked using the lattice Boltzmann method (LBM), a well-acknowledged approach to exploring nanoconfined fluid dynamics. In addition, coupled with digital cores, the flow characteristics of shale reservoirs are characterized. The total porosities of bedding fractures in shale and lamellar shale are 2.042% and 1.085%, respectively. The single-phase oil flow inside bedding fractures follows Darcy’s linear flow principle.... [more]

The Lower Permian Fengcheng Formation in Halaalate Mountain in the Junggar Basin has enormous potential for shale oil, while few investigations on quantifying pore structure heterogeneity have been conducted. Thus, total organic carbon (TOC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and low-temperature N2 adsorption tests were conducted on the shales collected from the HSX1 well in the Hashan region to disclose the microscopic pore structure and its heterogeneity. Results show that the selected shales mainly consist of quartz, plagioclase, calcite, and clay minerals. The primary pore types are intergranular pores in quartz and carbonate and intragranular pores in clays, while organic matter (OM) pores are rare. Typical types of H2 and mixed H2-H3 were observed. Type H3 shale pore size distributions (PSD) are unimodal, with a peak at about 70 nm, while Type H2-H3 shales are bimodal, with peaks at about 70 nm and 3 nm, respectively. Type H3 shales have lower D2 than T... [more]

Roof fall is a frequent and destructive disaster in the working face of extra-thick coal seams. The important technology for disaster elimination is roof grouting, and the key to its success is to accurately predict the distance of the advanced fractures based on a reasonable rock constitutive relationship. In this paper, the constitutive relationship reflecting the progressive failure process of rock was established, including the elastic−plastic constitutive relation of intact rock, the fracture constitutive relation of non-penetrating fracture, and the shear friction constitutive relation of penetrating fracture. On this basis, the finite−discrete element method (FDEM) numerical calculation method was developed. Taking Yushupo Coal mine with a 16-m-thick coal seam as an example, the numerical results showed that the fractures in the roof appear 15~35 m ahead of the working face, and the maximum value of advance bearing pressure is between 16 and 30 MPa. Meanwhile the laboratory test... [more]

Conventional radiation-shielding composites usually contain lead, which results in high toxicity and poor portability. Tungsten (W) is an ideal radiation-shielding element that can replace lead due to its high atomic number and non-toxicity. In this work, radiation-shielding composites were prepared using natural rubber (NR) as a matrix and three different particle size powders, namely W, WO3 and WC, as fillers. The results show that, for X-rays, the linear attenuation coefficient of radiation-shielding composites based on natural rubber containing WC with a particle size of 50 μm (50 WC/NR) is 27.005 cm−1 at an X-ray tube voltage of 40 kV, which is more than 14 times the linear attenuation coefficient of NR. For γ-rays, a linear attenuation coefficient of 50 WC/NR achieves 8.320 cm−1 at 81 keV, which is over 55 times the linear attenuation coefficient of NR. In addition, 50 WC/NR had the highest elongation at break at 548.989% and had the lowest hardness at 62 HA. In summary, 50 WC/NR... [more]