From the 2000s onwards, unprecedented space missions have brought about a wealth of novel investigations on the different aspects of space geomechanics. Such aspects are related to the exploratory activities such as drilling, sampling, coring, water extraction, anchoring, etc. So far, a whole range of constitutive research projects on the plate tectonics, morphology, volcanic activities and volatile content of planetary bodies have been implemented. Furthermore, various laboratory experiments on extraterrestrial samples and their artificial terrestrial simulants are continually conducted to obtain the physical and mechanical properties of the corresponding specimens. Today, with the space boom being steered by diverse space agencies, the incorporation of geomechanics into space exploration appreciably appears much needed. The primary objective of this article is to collate and integrate the up-to-date investigations related to the geomechanical applications in space technologies. Empha... [more]

The solidification process in a multi-tube latent heat energy system is affected by the natural convection and the arrangement of heat exchanger tubes, which changes the buoyancy effect as well. In the current work, the effect of the arrangement of the tubes in a multi-tube heat exchanger was examined during the solidification process with the focus on the natural convection effects inside the phase change material (PCM). The behavior of the system was numerically analyzed using liquid fraction and energy released, as well as temperature, velocity and streamline profiles for different studied cases. The arrangement of the tubes, considering seven pipes in the symmetrical condition, are assumed at different positions in the system, including uniform distribution of the tubes as well as non-uniform distribution, i.e., tubes concentrated at the bottom, middle and the top of the PCM shell. The model was first validated compared with previous experimental work from the literature. The resul... [more]

A clear gap was identified in the literature regarding the in-depth evaluation of scaling up thermal energy storage components. To cover such a gap, a new methodological approach was developed and applied to a novel latent thermal energy storage module. The purpose of this paper is to identify some key aspects to be considered when scaling up the module from lab-scale to full-scale using different performance indicators calculated in both charge and discharge. Different normalization methods were applied to allow an appropriate comparison of the results at both scales. As a result of the scaling up, the theoretical energy storage capacity increases by 52% and 145%, the average charging power increases by 21% and 94%, while the average discharging power decreases by 16% but increases by 36% when mass and volume normalization methods are used, respectively. When normalization by the surface area of heat transfer is used, all of the above performance indicators decrease, especially the av... [more]

We present a numerical calculation of the heat transport in a Bragg mirror configuration made of materials that do not obey Fourier’s law of heat conduction. The Bragg mirror is made of materials that are described by the Cattaneo-Vernotte equation. By analyzing the Cattaneo-Vernotte equation’s solutions, we define the thermal wave surface impedance to design highly reflective thermal Bragg mirrors. Even for mirrors with a few layers, very high reflectance is achieved (>90%). The Bragg mirror configuration is also a system that makes evident the wave-like nature of the solution of the Cattaneo-Vernotte equation by showing frequency pass-bands that are absent if the materials obey the usual Fourier’s law.

Light olefins are the main building blocks used in the petrochemical and chemical industries for the production of different components such as polymers, synthetic fibers, rubbers, and plastic materials. Currently, steam cracking of hydrocarbons is the main technology for the production of light olefins. In steam cracking, the pyrolysis of feedstocks occurs in the cracking furnace, where hydrocarbon feed and steam are first mixed and preheated in the convection section and then enter the furnace radiation section to crack to the desired products. This paper summarizes olefin production via the steam cracking process; and the reaction mechanism and cracking furnace are also discussed. The effect of different operating parameters, including temperature, residence time, feedstock composition, and the steam-to-hydrocarbon ratio, are also reviewed.

As newly emerged 2D layered transition metal carbides or carbonitrides, MXenes have attracted growing attention in energy conversion and storage applications due to their exceptional high electronic conductivity, ample functional groups (e.g., -OH, -F, -O), desirable hydrophilicity, and superior dispersibility in aqueous solutions. The significant advantages of MXenes enable them to be intriguing structural units to engineer advanced MXene-based nanocomposites for electrochemical storage devices with remarkable performances. Herein, this review summarizes the current advances of MXene-based materials for energy storage (e.g., supercapacitors, lithium ion batteries, and zinc ion storage devices), in which the fabrication routes and the special functions of MXenes for electrode materials, conductive matrix, surface modification, heteroatom doping, crumpling, and protective layer to prevent dendrite growth are highlighted. Additionally, given that MXene are versatile for self-assembling i... [more]

The negative environmental impact of cement production emphasizes the need to use alternative binders for construction materials. Alkali-activated slag is a more environmentally friendly candidate which can be utilized in the design of mortars with favorable material properties. However, the electrical properties of such materials are generally poor and need to be optimized by various metallic or carbon-based admixtures to gain new sophisticated material functions, such as self-sensing, self-heating, or energy harvesting. This paper investigates the influence of waste metal powder originating from the 3D printing process on the material properties of alkali-activated slag mortars. The untreated metal powder was characterized by means of XRD and SEM/EDS analyses revealing high nickel content, which was promising in terms of gaining self-heating function due to the high electrical conductivity and stability of nickel in a highly alkaline environment. The designed mortars with the waste m... [more]

Recently, to meet the growing demand for stable and flexible batteries, anodes in the form of thin films have drawn the attention of researchers. It is clear that mass production of such batteries would bring the worldwide distribution of flexible devices and wearable electronics closer. Currently, electrodes are deposited on a flexible substrate and consist of conductive and binding agents that increase the volume/weight of the electrode. Here, we propose free-standing and non-active-material-free thin films based on reduced graphene oxide (rGO), titanium dioxide (TiO2) and manganese dioxide (MnO2) as working electrodes in lithium-ion half-cells prepared via the vacuum-assisted filtration method. The electrochemical performance of the assembled half-cells exhibited good cyclic stability and a reversible capacity at lower current densities. The addition of TiO2 and MnO2 improved the capacity of the rGO film, while rGO itself provided a stable rate performance. rGO/TiO2/MnO2 film showed... [more]

REMgNi4-based alloys, RE(2−x)MgxNi4 (RE: rare-earth metals; 0 < x < 2), with a AuBe5-type crystal structure, exhibit reversible hydrogen absorption and desorption reactions, which are known as hydrogen storage properties. These reactions involve formation of three hydride phases. The hydride formation pressures and hydrogen storage capacities are related to the radii of the RE(2−x)MgxNi4, which in turn are dependent on the radii and compositional ratios of the RE and Mg atoms. The crystal structures formed during hydrogen absorption reactions are the key to understanding the hydrogen storage properties of RE(2−x)MgxNi4. Therefore, in this review, we provide an overview of the crystal structures in the hydrogen absorption reactions focusing on RE(2−x)MgxNi4.

In this work, the influence of temperature on textural, morphological, and crystalline characterization of bio-adsorbents produced by hydrothermal carbonization (HTC) of corn stover was systematically investigated. HTC was conducted at 175, 200, 225, and 250 °C, 240 min, heating rate of 2.0 °C/min, and biomass-to-H2O proportion of 1:10, using a reactor of 18.927 L. The textural, morphological, crystalline, and elemental characterization of hydro-chars was analyzed by TG/DTG/DTA, SEM, EDX, XRD, BET, and elemental analysis. With increasing process temperature, the carbon content increased and that of oxygen and hydrogen diminished, as indicated by elemental analysis (C, N, H, and S). TG/DTG analysis showed that higher temperatures favor the thermal stability of hydro-chars. The hydro-char obtained at 250 °C presented the highest thermal stability. SEM images of hydro-chars obtained at 175 and 200 °C indicated a rigid and well-organized fiber structure, demonstrating that temperature had... [more]

The MARIA research reactor is designed and operated as a multipurpose nuclear installation, combining material testing, neutron beam experiments, and medical and industrial radionuclide production, including molybdenum-99 (99Mo). Recently, after fuel conversion to LEU and rejuvenation of the staff while maintaining their experience, MARIA has been used to respond to the increased interest of the scientific community in advanced nuclear power studies, both fission and fusion. In this work, we would like to introduce MARIA’ s capabilities in the irradiation technology field and how it can serve future nuclear research worldwide.

The numerical, analytical, theoretical and experimental study of thermal transport is an active field of research due to its enormous applications and use in numerous systems. This report covers the impacts of thermal transport on pseudo-plastic material past over a horizontal, heated and stretched porous sheet. Modeling of energy conservation is based upon a generalized heat flux model along with a heat generation/absorption factor. The modeled phenomenon is derived in the Cartesian coordinate system under the usual boundary-layer approach proposed by Prandtl, which removes the complexity of the problem. The modeled rheology is obtained in the form of coupled, nonlinear PDEs. These derived PDEs are converted into ODEs with the engagement of similarity transformation. Afterwards, converted ODEs containing some emerging parameters have been approximated numerically with a powerful and effective scheme, namely the finite element approach. The obtained results are compared with the publis... [more]

A combined immersed boundary−lattice Boltzmann approach is used to simulate the dynamics of the fluid−structure interaction of a hollow sealing strip under the action of pressure difference. Firstly, the multiple relaxation times LBM model, hyper-elastic material model and immersed boundary method were deduced. According to the strain characteristics of hyper-elastic materials and the specific situation of friction between the elastic boundary and solid boundary, the internal force and the external force on the immersed boundary were discussed and deduced, respectively. Then, a 2D calculation model of the actual hollow sealing strip system was established, during which technical problems such as the equivalent wall thickness of the sealing strip and the correction of the stiffness of the contact corner were solved. The reliability of the model was verified by comparing results of FEM simulation of quasi-static deformation. Following this, the simulation results of three typical cases o... [more]

Phase change material (PCM) has received significant attention due to its great potential for thermal energy storage. However, the major undesirable property of PCM is related to its low thermal conductivity. In this work, the electrohydrodynamic (EHD) enhancement of PCM melting in circular-elliptical annuli is investigated numerically by using the lattice Boltzmann method (LBM). The key motivation for our choice of the elliptical shape is due to the fact that the more curved elliptical surface corresponds to stronger charge injection strength, which may lead to stronger flow field, and the consequent increase of heat transfer rate. The influences of several non-dimensional parameters, including electric Rayleigh number T, thermal Rayleigh number (Ra) and the aspect ratio (AR) of the inner ellipse are investigated in detail. Based on the numerical results, it is found that the radial electro-convective flow induced by the external electric field makes a significant contribution to the... [more]

In the frame of the pre-conceptual design activities of the DEMO work package DIV-1 “Divertor Cassette Design and Integration” of the EUROfusion program, a mock-up of the divertor outer vertical target (OVT) was built, mainly in order to: (i) demonstrate the technical feasibility of manufacturing procedures; (ii) verify the hydraulic design and its capability to ensure a uniform and proper cooling for the plasma facing units (PFUs) with an acceptable pressure drop; and (iii) experimentally validate the computational fluid-dynamic (CFD) model developed by the University of Palermo. In this context, a research campaign was jointly carried out by the University of Palermo and ENEA to experimentally and theoretically assess the hydraulic performances of the OVT mock-up, paying particular attention to the coolant distribution among the PFUs and the total pressure drop across the inlet and outlet sections of the mock-up. The paper presents the results of the steady-state hydraulic experiment... [more]

In an effort to identify new sources of critical raw materials (CRMs) possibility of recovering selected CRMs from Polish coals, chars, and ashes resulting from the combustion of coals and chars was investigated. The samples were collected from pilot fluidized bed gasification systems. The search for CRMs in coal gasification wastes has not been widely reported before. The study used 2 bituminous coal and 1 lignite sample; the concentration of individual critical raw materials (CRMs) was analyzed using the ICP-MS method. The obtained results were compared with Clarke values in coal ash and in the Earth’s crust, and with the adopted cut-off grade. As shown by the analysis, the highest concentrations of CRMs can be found in fly ash, mainly in samples from the eastern part of the Upper Silesian Coal Basin. This applies mostly to Be, Cs, or Sb due to the fact that their concentrations were found to be higher than the Clarke value in the Earth’s crust; the mentioned fly ashes could be used... [more]

This paper evaluates the thermal performance of a triple-glazed glass window filled with a phase-change material (PCM) compared to the performance of a traditional triple-glazed window with air gaps. The chosen PCM was paraffin wax. A mathematical model to simulate heat transfer within the system was presented. A commercially available software, COMSOL Multiphysics, was used to numerically solve the governing equations. The analysis was carried out for the representative days of different seasons using three types of paraffin wax (5, 10, and 15) that have different melting-temperature ranges. Particularly, the study considers the unique climatic conditions of the Arctic region. Results showed that by integrating a PCM into the cavity of triple-glazing, thermal performance during summer season of the window was enhanced, while for spring and autumn thermal performance was affected by the type of paraffin selected. The thermal performance of glass windows during winter did not change wit... [more]

One of the most important causes of insulation system failure is the breakdown of the interface between two solid dielectrics; understanding the mechanisms governing this breakdown phenomenon is therefore critical. To that end, investigating and reviewing the practical limitations of the electrical breakdown strength of solid−solid interfaces present in insulating components is the primary objective of this work. The published literature from experimental and theoretical studies carried out in order to scrutinize the effects of the presence of solid−solid interfaces is investigated and discussed, considering macro, micro, and nano-scale characteristics. The reviewed literature suggests that solid−solid interfaces in accessories have non-uniform distributions of electrical fields within them in comparison to cables, where the distribution is mostly radial and symmetrical. Many agree that the elastic modulus (elasticity), radial/tangential pressure, surface smoothness/roughness, and diel... [more]

The importance of medical waste management has grown during the COVID-19 pandemic because of the increase in medical waste quantity and the significant dangers of these highly infected wastes for human health and the environment. This innovative review focuses on the possibility of materials, gas/liquid/solid fuels, thermal energy, and electric power production from medical waste fractions. Appropriate and promising treatment/disposal technologies, such as (i) acid hydrolysis, (ii) acid/enzymatic hydrolysis, (iii) anaerobic digestion, (vi) autoclaving, (v) enzymatic oxidation, (vi) hydrothermal carbonization/treatment, (vii) incineration/steam heat recovery system, (viii) pyrolysis/Rankine cycle, (ix) rotary kiln treatment, (x) microwave/steam sterilization, (xi) plasma gasification/melting, (xii) sulfonation, (xiii) batch reactor thermal cracking, and (xiv) torrefaction, were investigated. The medical waste generation data were collected according to numerous researchers from various... [more]

In our recent papers, it was shown that the thermal nanocrystallization of glassy analogs of selected cathode materials led to a substantial increase in electrical conductivity. The advantage of this technique is the lack of carbon additive during synthesis. In this paper, the electrochemical performance of nanocrystalline LiFePO4 (LFP) and LiFe0.88V0.08PO4 (LFVP) cathode materials was studied and compared with commercially purchased high-performance LiFePO4 (C-LFP). The structure of the nanocrystalline materials was confirmed using X-ray diffractometry. The laboratory cells were tested at a wide variety of loads ranging from 0.1 to 3 C-rate. Their performance is discussed with reference to their microstructure and electrical conductivity. LFP exhibited a modest electrochemical performance, while the gravimetric capacity of LFVP reached ca. 100 mAh/g. This value is lower than the theoretical capacity, probably due to the residual glassy matrix in which the nanocrystallites are embedded... [more]

Piezoelectric-based nano resonators are smart structures that can be used for mechanical sensors and actuators in miniature systems. In this study, the nonlinear vibration behavior of a curved piezoelectric-layered nanotube resonator was investigated. The curved structure comprises a core nanotube and a slender layer of piezoelectric material covering the inner nanotube where a harmonic voltage is applied to the piezoelectric layer. Applying the energy method and Hamiltonian principle in association with non-local theories, the governing equations of motion of the targeted system are obtained. Then, the problem is solved using the Galerkin and multiple scales methods, and the system responses under external excitation and parametric load are found. Various resonance conditions are investigated including primary and parametric resonances, and the frequency responses are obtained considering steady state motions. The effects of different parameters such as applied voltage, piezoelectric... [more]

This research article explores the behavior of a phase change material (PCM) when it undergoes interrupted melting and freezing, through experimental investigations using a heat flow meter apparatus. A fatty acid-based organic PCM, encapsulated within polyethylene and thin aluminum foil layers, was experimentally tested in this study. Experiments were designed to represent multiple interrupted phase change scenarios that could occur within PCMs applied in buildings. The experimental results were analyzed and compared with previously reported assumptions in numerical models dealing with PCM hysteresis and interrupted phase change processes. These comparisons indicated that the assumptions used in the different numerical models considered can capture the interrupted phase change phenomena with varying degrees of accuracy. The findings also highlighted the need for additional experimental research on different phase change processes that can occur in building applications of PCMs.

High-temperature desulfurization techniques are fundamental for the development of reliable and efficient conversion systems of low-cost fuels and biomass that answer to the nowadays environmental and energy security issues. This is particularly true for biomass gasification coupled to SOFC systems where the sulfur content has to be minimized before being fed to the SOFC. Thus, commercially available zinc oxide has been studied and characterized as a desulfurizing agent in a fixed-bed reactor at high temperatures from 400 °C to 600 °C. The sorbent material was characterized by XRD, BET, SEM, and EDS analyses before and after adsorption. The sorbent’s sorption capacity has been evaluated at different temperatures, as well as the breakthrough curves. Moreover, the kinetic parameters as the initial sorption rate constant k0, the deactivation rate constant kd, and the activation energy have been calculated using the linearized deactivation model. The best performances have been obtained at... [more]

Air pollution is a significant problem in city centers. According to public health care in Poland, there is a need for local authorities to propose good purification solutions in both outdoor and indoor conditions. The main objective of this study is the development of an appropriate filtration system for public transport, especially for buses and bus stops. Firstly, the authors justify the need for air filtration in the capital of Poland, Warsaw. The average concentration level of PM10 and PM2.5 dust particles in large Polish cities is presented. In addition, it is underlined that PM2.5 dust particles are carriers for coronavirus COVID-19 and easily inhaled by humans. In the next step, the authors introduce an experimental stand used in the examination of different filtration baffles. The filtration efficiency is defined and calculated according to experimental examinations. In these experiments, an antismog cover for air-conditioning split systems, an H13 HEPA filter and a three-stag... [more]

Epoxy nanocomposites reinforced with glass fiber, have been prepared with various weight percentages (1, 3, and 5 wt.%) of MgO nanofillers to improve their electrical and thermal performance. An increase in MgO nanofiller content up to 3 wt.% tends to enhance surface discharge and corona inception voltages measured using fluorescence and UHF methods, under both AC and DC voltage profiles. Reduced initial surface potential along with increased decay rate is observed after inclusion of MgO nanoparticles. Before and after the polarity reversal phenomena, heterocharge formation is observed in the bulk of test specimens. In comparison with other test samples, the 3 wt.% sample had reflected lower electric field enhancement factor. After MgO filler was added to glass fiber reinforced polymer (GFRP) composites, the coefficient of thermal expansion (CTE) has reduced, with the 3 wt.% specimen having the lowest CTE value. TGA measurements revealed an improvement in thermal stability of the GFRP... [more]