In this work, the adsorption of CO onto the surface of the transition metal Ni at different coverage levels was explored based on the density functional theory (DFT). The corresponding periodic slab plate models were established, and the adsorption parameters and CO electronic states on different nickel surfaces under different coverage (0.11 mL, 0.25 mL and 0.5 mL) were calculated. The results showed that the most stable adsorption sites on Ni (111) and Ni (100) crystal surfaces were valley sites, while the most stable adsorption sites on a Ni (110) surface was a short bridge site. By comparing the energy of the same adsorption sites, it was found that the adsorption of CO on a Ni (100) crystal surface was superior to the other two surfaces. Furtherly, from the perspective of the electronic structure, the density of states (DOSs) of Ni atoms and CO molecules were calculated before and after adsorption. The density of states showed that the main factor of surface adsorption generation... [more]

The thermal safety problem of lithium-ion batteries (LIB) in use requires an excellent thermal management system to preserve it. In the paper, an expansion flame-retardant composed of APP and CFA and kaolinite is used to enhance the flame-retardant property of phase change materials (PCM). The performances of PCM and their property in the thermal management of LIB were studied. The results indicate that the kaolinite can improve the long-term thermostability of PCM. The addition of flame retardant can make the flame-retardant property of PCM reach V0 level. The synergistic action of expansion flame-retardant and kaolinite can increase the residual carbon and enhance the thermal reliability of flame-retardant PCM (RPCM). The RPCM has an obvious cooling effect on the surface temperature of the battery. The RPCM can reduce the maximum temperature of the cell to 37.4 °C at 3 C, which is 12 °C lower than pure PA. The peak temperature of the battery pack at 3 C is also reduced to 50.28 °C by... [more]

Being continuously abandoned in huge amounts year-round by freight industry, shipping containers meet increasing regenerative utility in forms of temporary buildings, small public facilities, etc., especially in fast-developing countries with large populations and high living intensities like China. Although recycled containers have been nicely entitled with green building visions, their characterized inferior thermal properties (low inertia, poor insulation, etc.) when compared to conventional building forms and materials will greatly hinder their energy-saving potential, especially under the serious future extreme climate expectations. It therefore becomes particularly necessary to uncover the actual energy and thermophysical behaviors of the container building typology, upon extreme future climate scenarios targeting zero carbon forms for small-scale and temporary buildings in the upcoming future. In reference to existing data, this study made reasonable predictions of future extrem... [more]

A P0 system is used in hybrid automobiles to improve engine economy and performance. An essential element of the P0 system for effectively transmitting power to the drive train is the belt drive system (BDS). The features of electric machine (EM) and internal combustion engines (ICE) are taken into account by standard energy management systems, such as the equivalent consumption minimization strategy (ECMS). In order to maximize the effectiveness of the P0 system, this work provides a novel formulation of the ECMS, which considers the power loss map of the BDS in addition to the characteristic maps of EM and ICE. A test bench is built up to characterize the BDS, and it is verified using an open-loop Hardware in the Loop (HIL) in the WLTP driving cycle. To find the most appropriate equivalence factors for the ECMS, which would ordinarily be tuned through trial and error, a genetic algorithm (GA) is used. With regard to the standard ECMS, the proposed methodology intends to reduce fuel u... [more]

It is critical and challenging to develop high performance transition metal phosphides (TMPs) electrocatalysts for oxygen evolution reaction (OER) to address fossil energy shortages. Herein, we report the synthesis of Co2P embedded in N-doped porous carbon (Co2P@N-C) via a facile one-step strategy. The obtained catalyst exhibits a lower overpotential of 352 mV for OER at a current density of 10 mA cm−2 and a small Tafel slope of 84.6 mV dec−1, with long-time reliable stability. The excellent electrocatalytic performance of Co2P@N-C can be mainly owed to the synergistic effect between the Co2P and highly conductive N-C substrate, which not only affords rich exposed active sites but also promotes faster charge transfer, thus significantly promoting OER process. This work presents a promising and industrially applicable synthetic strategy for the rational design of high performance nonnoble metal electrocatalysts with enhanced OER performance.

Disposal of the coal fly ash (CFA) generated from thermal power plants in huge quantities is one of the major concerns for the industry, as well as the natural environment. On the other hand, CFA can be used within a certain percentage range in the cement concrete mix as a replacement for cement. Nanomaterials can also be used to improve the properties of concrete. Therefore, this study investigated the effects of nanosilica (nS) on the mechanical parameters and microstructure of CFA cement concretes. This study utilized an nS content of 5%, along with three CFA contents, i.e., of 0, 15, and 25% by volume. Mechanical property tests and a thorough overview of changes in the structure of modified concrete were carried out to study the effect of the CFA content on the analyzed parameters of concrete containing nS. This study had the goal of elucidating the reinforcing mechanisms of CFA concrete by nS and providing design guidance for the practical engineering applications of CFA-nS compos... [more]

The numerical study of solid/liquid phase change problems represents a large and ongoing field of research with many applications. These simulations should run as fast and accurately as possible. Therefore, proceeding from previous work and findings from the literature, this study investigates enthalpy methods for solving solid/liquid phase change problems. The relationship between temperature and enthalpy is strongly non-linear and requires special treatment; iteratively corrected methods, as well as approaches that do not correct the temperature/enthalpy relationship at all or only once per time step, were considered for a one-dimensional test problem. Based on the results of this study, two solvers can be recommended, the so-called optimum approach and a simple explicit method; both provide accurate results. The explicit method is easy to program, but the optimum approach allows larger time steps and is, therefore, faster. The influence of several parameters was investigated. The me... [more]

Mechanical mining is a widely used method of separating materials from the face to obtain a useful mineral (e.g., coal, metal ores, salts, and diamonds), to make underground workings (e.g., mine galleries, tunnels, and underground garages), level roads, shape slopes, or to dig ditches. Mechanical mining is applied in the mining branch, tunnelling, road, and construction industries. Depending on the mechanical properties of the rocks, most frequently described by uniaxial compression strength, various machines and tools are used. The methods of mining high-strength abrasive rocks that have been used and developed in recent years are particularly applicable to the mining of copper, gold, tungsten, platinum ores, diamond deposits, and tunnelling. In addition to rock strength, the effectiveness of the mining process is affected by abrasiveness, which influences the rate of abrasive tool wear. Therefore, in various research and development centres, but also in production companies, tools ar... [more]

Photovoltaic (PV) technology is the symbol of a sustainable future in many countries around the globe [...]

The magnetic properties of magnetic cores are essential for the design of electrical machines, and consequently appropriate mathematical modeling is needed. Usually, the design and analysis of electrical machines consider only the one-dimensional (1D) magnetic properties of core materials, i.e., the relationship of magnetic flux density (B) versus magnetic field strength (H), and their associated power loss under 1D magnetization, in which the B and H are constrained in the same orientation. Some studies have also been performed with the two-dimensional (2D) magnetizations in which the B and H are vectorial, rotating on a plane, and they may not be in the same direction. It has been discovered that the 2D rotational property is very different from its 1D alternating counterpart. However, the magnetic fields in an electrical machine, in particular claw pole and transverse flux machines, are naturally three-dimensional (3D), and the B and H vectors are rotational and may not lie on the s... [more]

The article analyzes the modern theory and practice of pipeline transport of bituminous oil together with low-viscosity solvent. In addition, a detailed analysis of the rheological models of non-Newtonian fluids is carried out, which establishes a number of assumptions on the rheology model selection algorithm currently in use (limited number of rheological models, variability in model coefficient assignment, etc.). Ways of their elimination are proposed. Dependencies for determination of the dynamic viscosity coefficient of binary oil mixtures are investigated. Calculation of the parameters of the bituminous oil mixture with solvent is considered. Complex experimental studies on rheology mixture models of bituminous oil and solvent on the example of the Ashalchinsky field (Russia, Tatarstan) in a wide range of temperatures and concentrations of the solvent are conducted. A two-dimensional field of rheological models of the oil mixture is constructed, which makes it possible to determi... [more]

The biofabrication of three-dimensional scaffolds using 3D printers and cell-containing bioinks is very promising. A wide range of materials and bioink compositions are being created and tested for cell viability and printability in order to satisfy the requirements of a bioink. This methodology has not still achieved technological maturity, and the actual costs mean that they are often inaccessible for researchers, consequently lowering the development and extending the required times. This research aims to apply this methodology on a laboratory scale by re-adapting a commercial 3D printer, consequently lowering the costs and energy impacts, and, at the same time, ensuring a level of accuracy extremely close to the currently adopted devices and, more in general, suitable for the scopes of the research. To accomplish this, we assembled a biomimetic scaffold made of human Umbilical Cord Matrix Stem Cells (hUCMS), cellulose, and alginate. Various molds were used to produce 3D scaffolds o... [more]

Worldwide gas emissions are being strictly regulated, therefore processes to reduce steam injection for enhanced oil recovery (EOR) require a deeper analysis to identify the means to contribute to environmental impact reduction. Lately the usage of additives such as a solvent for steam injection processes has taken a new interest due to its positive impact on improving oil recovery and energy efficiency and reducing greenhouse gas emissions. In that sense, the use of nanoparticles in thermal EOR has been explored due to its impact on avoiding the volatilization of the solvent, offering greater contact with the oil in the reservoir. Nanoparticles have well-known effects on asphaltenes adsorption, aquathermolysis reactions, oil upgrading, and improving energy efficiencies. This article presents a summary and ranking of the nanoparticles evaluated in nanofluid-based solvent for steam processes, specifically in the catalysis of aquathermolysis reactions. A novel experimental design is prop... [more]

Lignin is an abundant and renewable source capable of replacing different raw materials in the chemical industry. It can be obtained from lignocellulosic biomass (LCB) via different pretreatment methods. In the present study, hydrolysis lignin (HL) from the SunburstTM pretreatment technology was utilized to investigate its enzymatic conversion. At first, soluble HL fractions were obtained via alkali solubilization followed by acid precipitation, referred to as acid precipitated lignin (APL). Furthermore, the APL was tested with three different bacterial laccases to identify the optimal conditions for its conversion into small molecular weight fractions. Among the tested laccases, Streptomyces coelicolor A3(2) (ScLac) displayed the highest rate of APL conversion with a high lignin dosage and under extremely alkaline conditions, i.e., 50 g/L in 0.25 M NaOH solution, resulting in higher molecular weight fractions. The increase in the molecular weight and quantitative linkages before and a... [more]

High water-cut oil production is one of the major issues in the petroleum industry. The present study investigates different profile control solutions, with an emphasis on selective methods and materials that mostly decrease the permeability of water-saturated reservoir areas. To achieve the selective water flow blockage in fractured porous media, the sodium silicate-based gel-forming composition was developed. The test procedure was created to assess selective and strength characteristics of the presented composition. According to the results of this procedure, adding polyatomic alcohols to the mentioned composition enhances its hydrophilic behavior in water-saturated rocks (work of adhesion increases from 117 to 129 mJ/m2) and reduces the hydrophobic behavior in oil-saturated rocks (work of adhesion drops from 110.3 to 77.4 mJ/m2). The selectivity of the composition performance is validated by its higher wettability of water-saturated reservoir rocks compared with oil-saturated; thus... [more]

This review comprehensively examines biochar, an essential material in an era of climate change for reducing carbon dioxide (CO2) emissions into the atmosphere. It is inconspicuous, black, lightweight, and very porous, and is produced through the thermal conversion of biomass. Our literature review highlights biochar’s expansive application possibilities. Firstly, its potential to improve soil quality and sequester CO2 has been examined, as well as its utilization in iron and steel manufacturing to minimize the quantity of coke and ultimately reduce CO2 emissions. In industrial manufacturing, the complete elimination of coke can promote environmental neutrality, which is achieved using biochar from biomass for its extrusion. Furthermore, biochar is becoming increasingly significant in modern energy storage technologies and as an important additive in Pickering emulsions, which are also employed in energy storage systems. Additionally, the use of carbon black is a broad topic, and this... [more]

Metal-halide perovskite solar cells (PSCs) have achieved remarkable power conversion efficiencies in recent years, and spiro-OMeTAD plays a significant role as a hole transport material in PSCs with record efficiencies. However, further studies and systematic experimental procedures on doped spiro-OMeTAD are required to enable a reliable process for potential commercialization. In particular, the effect of the prolonged oxidation of Co(III)TFSI co-doped spiro-OMeTAD has been one of the unanswered topics in PSC research. In this work, we investigate the influence of overnight oxidation on the performance of PSCs with Co(III)TFSI co-doped spiro-OMeTAD. Co-doping spiro-OMeTAD with Co(III) complexes instantly oxidizes spiro-OMeTAD, leading to an improvement in power conversion efficiency (PCE) from 13.1% (LiTFSI-doped spiro-OMeTAD) to 17.6% (LiTFSI + Co(III)TFSI-doped spiro-OMeTAD). It is found that PSCs with spiro-OMeTAD co-doped with Co(III)TFSI without overnight oxidation could retain a... [more]

According to the latest research, nanofluids as a possible future substitution for high-voltage equipment insulation have the potential to enhance the heat transfer and insulation properties of their base fluids. Dielectric properties are represented by breakdown strength (AC, DC, lightning) and dielectric performance as a set of quantities including dissipation factor, permittivity, and volume resistivity. In this study, natural and synthetic esters were mixed with C60 nanoparticles. Samples were examined for dissipation factor, relative permittivity, and volume resistivity at temperatures between 25 °C and 140 °C to monitor changes in dielectric performance with rising temperature, in accordance with IEC 60247. In addition, the samples were tested for AC breakdown voltage (using mushroom-like electrodes with a gap distance of 1 mm) and evaluated using the Weibull distribution statistical method. These measurements allowed complex evaluation of the examined mixtures and the determinat... [more]

Metal oxide and metal dichalcogenide heterostructure composites are promising candidates for electrochemical use. In this study, a hybrid heterostructure composite electrode material was made using a straightforward hydrothermal process using transition metal oxide (NiO) and metal dichalcogenide (MoS2). The surface of the flower-like structured MoS2 was grown with granular structured NiO, and this heterostructure composite exhibited considerably improved specific capacitance when compared to the pure NiO and MoS2 materials. The pseudocapacitive performance was effectively supported by the heterostructure combination of transition metal oxide (TMOs) and metal dichalcogenide (MDC), which greatly improved ion transport within the material and storage. At a current density of 1 A/g, the prepared heterostructure composite electrode material exhibited a specific capacitance of 289 F/g, and, after 2000 cycles, the capacitance retained 101% of its initial value. The symmetric device was constr... [more]

This paper introduces a novel waveguide intended for the spatial transfer of alternating magnetic fields. Instead of ferromagnetic material, an air core was proposed, while the cladding was realized using anisotropic metamaterial, built of the resonators and a paramagnetic composite. Since prior works regarding magnetic field transfer concentrated on static or high frequency fields, the proposed device complements the range of medium frequencies (several to hundreds of kilohertz). The three-dimensional model of the 50 cm long and 20 cm wide rectangular structure with metamaterial cladding was made in COMSOL and computed using the finite element method. Multi-turn inductors were considered and homogenized by the current sheet approximation, while an optimization solver was used to identify an optimal design of the waveguide. The analysis was made with respect to different resonators and permeability of the paramagnetic material. Additionally, the frequency response of the structure was... [more]

Flue gas flooding has been applied in many oilfields for its accessibility and low cost. However, the problem of gas channeling during flue gas flooding is significantly more serious due to reservoir heterogeneity and gravity override, and the traditional profile control agent is inapplicable because of flue gas acidity. In order to solve this challenge, a novel acidic nanoparticle was presented first; then, the profile control performance of both water slugs and this novel nanoparticle for flue gas flooding in heterogeneous reservoirs was studied using core samples with different rhythms. The results show that the stability of the acidic nanoparticles is good, and the viscosity of the nanoparticle solution increases as the pH decreases, which is suitable for acidic flue gas flooding. The oil recovery of flue gas flooding in a positive rhythm core is 5−10% greater than that in a reverse rhythm core. The water slug can improve oil recovery by 5% in the reverse rhythm core, and oil recov... [more]

The present paper deals with the evaluation of the unique design of the thermal energy storage unit and its impact on the overall heat exchange efficiency. The proposed thermal energy storage unit consists of a gyroid thermally conductive structure, the voids of which are filled with sodium acetate trihydrate. The presented concept is focused on the use in the field of heavy machinery, where it is possible to accumulate and re-use waste heat from internal combustion engines from the cooling liquid or lubricating products. The evaluation of designs took place through numerical simulations on three models characterized by different levels of the introduction of the gyroid structure into the design. From the design point of view, the gyroid structure was considered as an object produced by additive manufacturing methods from a thermally conductive filament based on a thermoplastic polymer, which enables considerable simplification of production compared to the use of suitable anti-corrosi... [more]

Biomass is currently the main renewable energy source (RES) in the EU, particularly in Poland. Solid biomass for energy purposes is primarily sourced from forests, the wood processing industry, and agriculture. A significant source of this energy feedstock could also be short-rotation woody crops (SRWCs), including black locust, poplar, and willow. Since numerous factors determine the SRWC biomass quality, the current study aimed at assessing biomass thermophysical properties and elemental composition depending on the plant species, soil enrichment procedure, and the plant harvest rotation over a consecutive 12-year period of cultivation. The characteristics under study, including the moisture content, ash content, volatile matter, fixed carbon, higher heating value (HHV), and the carbon, hydrogen, nitrogen, sulfur, and chlorine contents, were significantly differentiated by all the main factors, i.e., the SRWC species, the soil enrichment procedure, the harvest rotation, and the inter... [more]

The paper presents the results of research on new electroconductive polymer materials, based on polypyrrole, for the different supercapacitor constructions, i.e., the symmetric and asymmetric constructions. All the supercapacitors considered contain ITO collectors. Measurements of the complex impedance frequency characteristics were performed for these elements using the electrochemical impedance spectroscopy (EIS) method. Selected fractional-order models, known from the literature, have been used to model the impedance of these elements. The Particle Swarm Optimization (PSO) algorithm was used to estimate the model parameters. Selected estimation results, their comparison, and conclusions are also presented in the paper. The type of active electrolyte component has the greatest impact on the shape of the impedance frequency characteristics. In most cases, the highest capacitance values and the smallest resistance values were obtained for asymmetric supercapacitors.

In this paper, N, N’-m-phenylene dimaleimide (HVA-2) grafted crosslinked polyethylene (XLPE) insulation materials with different HVA-2 contents were prepared. The grafting, crosslinking, and crystalline structure were characterized by Fourier-transform infrared spectroscopy (FTIR), Soxhlet extraction, and differential scanning calorimetry (DSC), respectively. The space charge distribution, direct current (DC) breakdown strength, and DC conduction current density were tested and the electronic structure was calculated from first-principles. HVA-2 grafting modification can significantly reduce the accumulation of space charges and the conduction current density of XLPE, but have a negative effect on DC breakdown strength. The polar groups of the grafted HVA-2 anchored on XLPE by the grafting reaction can introduce deep traps densely and evenly in XLPE, which would capture and scatter charge carriers, thus reducing the carrier concentration and mobility and further improving the space cha... [more]