Cyclic Process Research Articles

Thermochemical heat storage performance of Fe-doped MgO/Mg(OH)2: Experimental and DFT investigation

MgO/Mg(OH)2 thermochemical heat storage system can realize large-scale energy storage by repetitive hydration/dehydration reactions to enhance the stability of solar energy utilization. However, slow interconversion and incomplete reactions caused by agglomeration restrict the cyclic heat storage capability of MgO/Mg(OH)2. In this work, a low-cost efficient Fe-doped MgO was prepared by a simple wet-mixing method and its energy released performance and kinetics in MgO/Mg(OH)2 heat storage progress were examined in a twin fixed-bed reactor and a simultaneous thermal analyzer. Additionally, density functional theory calculations were used to examine the impact of Fe on the mechanisms of MgO/Mg(OH)2 heat storage process. The results shows that when the molar ratio of MgO to Fe is 95:5, the energy released density of Fe-doped MgO is about 400 % higher than that of MgO after 10 heat storage cycles. In preparation process, the existence of Fe leads to the generation of MgFe2O4, which forms layered microstructure with the high specific surface area and pore volume and mitigates agglomeration behavior of MgO. It improves the cyclic stability of MgO and reduces the dehydration temperature of Mg(OH)2, and simultaneously the activation energy of the dehydration stage is reduced by 33.2 %. Fe enhances the interaction of H2O with the MgO surface and promotes the dissociation of H2O on Mg(OH)2 surface. Combined with economic analysis, Fe-doped MgO is a suitable material for MgO/Mg(OH)2 heat storage cycles.

Intense thermal shock generators made of micron-thick SnO2 layers for the on-chip rapid thermal processing in air

Thermal shock-resistant heaters are essential in various electronic devices, including chemical sensors and pyroelectric electron emitters. The advent of ultrafast high-temperature sintering and shock synthesis of nanomaterials has increased the demand for air-operating high-rate joule heaters. Moreover, incorporating such heaters at the chip level would revolutionize current rapid thermal processing methods in semiconductor technology. Here, transparent micron-thick SnO2 resistors are grown by spray pyrolysis on alumina, silica, and oxidized silicon chips and used as thermal shock-resistant air-operating heaters. These heaters can generate repeated heating cycles at rates of 15,000 °C/s up to 900 °C/s. Tin is a group IV element and its impact on Si- and SiO2-based devices is minimal making the presented device silicon compatible. The superior performance of the presented heaters is attributed to the tin oxide’s unique combination of physicochemical properties including high-temperature chemical stability in oxidizing atmospheres, suitable intrinsic conductivity, and optimal negative temperature coefficient of resistance. The application of the SnO2 heaters for the rapid on-chip high-temperature oxidation and sintering of low-melting-point metal thin films, while preserving the metal layer’s nanotexture, is demonstrated.

Characterization of the Ratcheting Effect on the Filler Material of a Steel Slag-Based Thermal Energy Storage

Thermocline thermal energy storage systems play a crucial role in enhancing energy efficiency in energy-intensive industries. Among available technologies, air-based packed bed systems are promising due to their ability to utilize cost-effective materials. Recently, one of the most intriguing filler materials under study is steel slag, a byproduct of the steel industry. Steel slag offers affordability, ample availability without conflicting usage, stability at temperatures up to 1000 °C, compatibility with heat transfer fluids, and non-toxicity. Previous research demonstrated favorable thermophysical and mechanical properties. Nonetheless, a frequently overlooked aspect is the endurance of the slag particles, when exposed to both mechanical and thermal stresses across numerous charging and discharging cycles. Throughout the thermal cyclic process, the slag within the tank experiences substantial loads at elevated temperatures, undergoing thermal expansion and contraction. This phenomenon can result in the deterioration of individual particles and potential damage to the tank structure. However, assessing the extended performance of these systems is challenging due to the considerable time required for thermal cycles at a relevant scale. To address this issue, this paper introduces a specially designed fast testing apparatus, providing the corresponding testing results of a real-scale system over 15 years of operation.

Estimation of the repeatability and reproducibility of test results in determining the degree of cure of protective paint coatings using differential scanning calorimetry

The degree of curing of protective paint-and-varnish coatings for oil country tubular goods is a parameter characterizing the completeness of their polymerization, and allows drawing a conclusion about the final physicomechanical properties and the possibility of using the material under specific conditions. This parameter is considered decisive in conducting acceptance tests and incoming quality control of pipe products with plated protective epoxy coatings despite a low accuracy of the obtained results and the impact of various instrumental factors and methodological approaches. The authors have developed a methodology for determining the curing degree of coatings based on the procedures given in regulatory documents (CSA Z245.20 Series-18, GOST R ISO 21809-2), taking into account the analysis of factors affecting the results of determining the curing degree carried out in the previous work. According to the conducted studies, the rates of heating and cooling during the measurement process, the temperature test program (in particular, the presence and duration of isothermal exposures before heating cycles), and curve processing methods were corrected and selected in the proposed methodology. The aim of this work is the analysis of the precision of the developed method for determining the curing degree of protective coatings to confirm the high accuracy of the obtained values under observing the prescribed procedure. The analysis was carried out by statistical processing of the results obtained in comparative tests performed in four testing laboratories, and included calculation of the repeatability of the results by their standard deviation, reproducibility and assessment of the acceptability of these parameters. The developed procedure for determining the curing degree of protective coatings, from sampling to processing of DSC curves, showed good precision, which indicates the reproducibility and repeatability of the proposed method. The developed method can be used as a unified sequence for determining the curing degree of paints and varnishes used as protective coatings in different laboratories.

Effect of dietary electrolyte balance and arginine to lysine ratio on hematological, antioxidant and immunological traits in dual-purpose breeding hens under cyclic heat stress condition

A total of 245 hens and 35 cocks (32 weeks age) were assigned to seven treatment groups (five replicates with seven hens and one cock) to investigate the effect of dietary electrolyte balance (DEB) and arginine to lysine ratio (Arg/Lys) on birds’ physiological and biochemical traits under cyclic heat stress (CHS) condition. Birds were housed in an environmentally controlled facility having four sectors. The first group (positive control, PC) was kept under thermoneutral conditions and fed diet with DEB of 180 mEq and Arg/Lys of 1.25, whereas the other six treatments were kept in the second sector under CHS and fed diet with DEB and Arg/Lys equal to: 180 mEq and 1.25 (negative control, NC); 250 mEq and 1.25; 320 mEq and 1.25; 180 mEq and 1.37; 250 mEq and 1.37; 320 mEq and 1.37, respectively. Hens on NC group had significantly decreased red blood cells (RBCs), white blood cells (WBCs) and its fractions. The groups fed different DEB and Arg/Lys in diet significantly enhanced the blood parameters and plasma lipid profile compared NC group. Hens under CHS fed on 250 and 320 DEB with 1.37 Arg/Lys recorded the lowest concentration of low-density lipoprotein (LDL) compared with the other groups. Triiodothyronine (T3) activity was not differed among groups, while T4 activity in layer exposed to CHS (NC group) recorded the highest activity compared to PC. From findings, it can be concluded that laying hens fed a diet having DEB 250 mEq with 1.37 Arg/Lys could be successfully applied to counteract the adverse effect of CHS and to improve blood hematological and biochemical traits, antioxidants, and immunity response.

Microstructural and Corrosion Behavior of Thin Sheet of Stainless Steel-Grade Super Duplex 2507 by Gas Tungsten Arc Welding

<div>Super duplex stainless steel (SDSS) is a type of stainless steel made of chromium (Cr), nickel (Ni), and iron (Fe). In the present work, a 1.6 mm wide thin sheet of SDSS is joined using gas tungsten arc welding (GTAW). The ideal parameter for a bead-on-plate trial is found, and 0.216 kJ/mm of heat input is used for welding. As an outcome of the welding heating cycle and subsequent cooling, a microstructural study revealed coarse microstructure in the heat-affected zone and weld zone. The corrosion rate for welded joints is 9.3% higher than the base metal rate. Following the corrosion test, scanning electron microscope (SEM) analysis revealed that the welded joint’s oxide development generated a larger corrosive attack on the weld surface than the base metal surface. The percentages of chromium (12.5%) and molybdenum (24%) in the welded joints are less than those in the base metal of SDSS, as per energy dispersive X-ray (EDX) analysis. Corrosion modeling is done using the COMSOL Multiphysics software. Electrochemical corrosion modeling is used to determine the electrolyte potential (i.e., 0.09 V) and current density (i.e., 0.2 A/m<sup>2</sup> to 1.8 A/m<sup>2</sup>). An entire mesh model contains 6240 elements. The largest and smallest element sizes are 4 mm and 0.1 mm, respectively. The maximum element rate of growth is 1.2.</div>

Cyclic Deracemization of rac‐Sulfoxides via Alternating Biocatalytic Reduction and Light‐Dependent Oxidation Employing Eosin Y as Photocatalyst

AbstractThe synergistic combination of biocatalysis and photocatalysis is emerging as powerful tool for the development of sustainable and atom‐efficient synthetic concepts facilitating an enormous portfolio of possible reactions which even goes beyond the capabilities found in nature. Here, a cyclic deracemization process is presented tailored for the synthesis of optically pure sulfoxides which are versatile structural motifs in asymmetric synthesis as well as in bioactive compounds. Enantioselective enzyme‐catalyzed reduction of rac‐sulfoxides was combined with a stereo‐unselective photocatalytic oxidation of the corresponding sulfide intermediate. The utilization of the readily accessible and rather inexpensive photocatalyst Eosin Y increases the usability of this synthetic method. To overcome the incompatibility between the photocatalyst Eosin Y and the biocatalytic step, the cyclic deracemization process was performed in a step‐wise fashion via alternated reduction in the darkness and oxidation under illumination. This modular system allowed precise adjustments of reaction parameters yielding the desired sulfoxide targets with up to >99 % ee. Evaluation of the substrate scope including a range of structurally diverse molecules demonstrated its broad applicability.

Ca-Cu/Al2O3 catalysts for H2S removal at near ambient temperature: Synthesis, characterization, DFT calculation, and mechanistic insights

A series of Ca-doped CuxO/Al2O3 catalysts were developed using the excessive impregnation method for H2S catalytic oxidation at near-ambient temperatures. Ca(NO3)-CuxO/Al2O3 catalyst with 2.5 wt% Ca exhibited optimal H2S desulfurization performance at 60 °C and RH 60%, achieving an H2S removal capacity of 401.34 mg/g. Experimental, characterization, and DFT calculation results demonstrate that during the catalytic oxidation of H2S, H2O can be catalytically convert into ·OH while simultaneously capturing and dissociating H2S. The ·OH and NO3- then catalyze the oxidation of HS-/S2- to elemental S. Moreover, the redundant OH adsorbed on the basic sites can buffer the pH and promote the dissociation of H2S. The above cyclic process could alleviate the deactivation of the Ca-Cu/Al2O3 catalyst. Therefore, a ·OH-induced desulfurization mechanism assisted with Ca2+ buffer the pH and NO3- cyclic oxidation of H2S has been proposed. This work contributes to the preparation of high-capacity mental-based catalysts for H2S oxidation.

Reviewing metal fluorides as the cathode materials for high performance Li batteries

AbstractExploring high‐energy density rechargeable lithium (Li) batteries is urgently needed to meet the demand of the large‐scale electric vehicle market. Conversion‐type metal fluorides (MFx) have been considered as desirable cathode materials for next‐generation rechargeable batteries because of their high operational voltages, environmental non‐toxicity, low cost, and high thermal stability. In this review, we present the most promising and feasible MFx applied in rechargeable Li batteries in terms of capacity, discharge potential, volume change, fabricated methods, crystal structure, and cost/abundance. The electrochemical performance is briefly illustrated, and the recent advances in mechanisms focused on MFx cathodes upon cyclic processes are noted and discussed in detail. Finally, prospects for the current challenges and possible research directions, with the aim to provide some inspiration for the development of MFx‐based cathodes are presented.

Electrothermal effect of carbon fiber and graphite reinforced metakaolin‐based geopolymer

AbstractThis paper investigates the influence of carbon fiber and graphite on the cyclic electrothermal performance of geopolymers (inorganic polymers). It was observed that carbon fibers, graphite, and the carbon fiber/graphite composite could form a stable conductive network at low voltage (3 V). However, under high voltages (9 and 12 V), the current of the geopolymer exhibited a peak shape in the first cycle, with higher voltages resulting in larger peak values and decreased conductivity in subsequent cycles. While graphite improved electrical and thermal conductivity, it weakened the microstructure, leading to an increase in microcracks and voids, and a reduction in the strength of geopolymers. The cumulative energy during the electrothermal process was calculated. The failure mechanism of the conductive network in the geopolymer during cyclic electrical heating was explained, highlighting the disruptive effect of gel shrinkage due to water loss on conductive networks.

Exploring morphological variation in bismuth ferrite nanostructures by pulsed laser deposition: synthesis, structural and electrochemical properties.

Structural and electrochemical properties of bismuth ferrite nanostructures produced by pulsed laser deposition with various morphologies are reported. The nanostructures are also explored as electrode materials for high-performance supercapacitors. Scanning electron microscopy images revealed that various bismuth ferrite morphologies were produced by varying the background pressure (10-6, 0.01, 0.10, 0.25, 0.50, 1.0, 2.0 and 4.0 Torr) in the deposition chamber and submitting them to a thermal treatment after deposition at 500◦C. The as-deposited bismuth ferrite nanostructures range from very compact thin-film (10-6, 0.01, 0.10 Torr), to clustered nanoparticles (0.25, 0.50, 1.0 Torr), to very dispersed arrangement of nanoparticles (2.0 and 4.0 Torr). The electrochemical characteristic of the electrodes was investigated through cyclic voltammetry process. The increase in the specific surface area of the nanostructures as background pressure in the chamber increases does not lead to an increase in interfacial capacitance. This is likely due to the wakening of electrical contact between nanoparticles with increasing porosity of the nanostructures. The thermal treatment increased the contact between nanoparticles, which caused an increase in the interfacial capacitance of the nanostructure deposited under high background pressure in the chamber.

Fundamental properties and intermolecular interaction of triethylene glycol + ethylenediamine aqueous solution for CO2 capture

Solvent absorption as a significant method for carbon dioxide capture, exploring the mechanism of CO2 capture and regeneration solvents is essential for industrial applications. In this work, water (H2O) + (ethylenediamine (EDA) + triethylene glycol (TEG)) system with the constant mole ratio (TEG: EDA = 1: 1) was chosen as the liquid absorbent. In order to gain a deeper comprehension of solution properties of H2O + (EDA + TEG) system, the density (ρ) and viscosity (η) of fundamental properties were measured at P = 1005 hPa and T = (298.15 K to 318.15 K) with the temperature step of 5 K. The excess properties, including excess molar volume (VmE), viscosity deviation (Δη), and excess Gibbs energy of activation of viscous flow (ΔG*E) of H2O + (EDA + TEG) system were calculated from the experimental ρ and η values, and fitted well with the Redlich-Kister polynomial equation. The above results combined with the spectra proved the existence of intermolecular interaction in H2O + (EDA + TEG) system, which favorably fixed CO2. Subsequently, the aqueous solution with mass fraction of 15 wt% EDA and molar ratio EDA: TEG = 1: 1 was used for absorbing CO2 (room temperature) and desorbing (378.15 K) for 5-time cycles, and the cycling absorption performance decreased. So as to explore the reason of degradation, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and nuclear magnetic resonance carbon spectroscopy (13C NMR) were used to analyze the circulating absorption mechanism of CO2 in H2O + (EDA + TEG) system, which revealed that alkyl carbonates and partially indecomposable substance 2-imidazolidinones generated in the cyclic process, and provided some implications for the industrial application.

Development of professional competence of future mathematics teachers in the HEI educational process

Relevance. The importance of this study is due to the evolution of modern education towards excellence and the need to constantly monitor the relationship between teacher�s self-education, knowledge culture, professional training and social requirements. For that reason, it is important to use modern approaches and methods to prepare a mathematics teacher. Purpose. The purpose of the study is to describe and diagnose the methodological and technical features of teacher training, to determine the level of competence of mathematics teachers in their work, their ability to use self-education techniques and the main methods of theoretical and methodological preparation for students' educational activities. Methodology. Typical methods used in research on this topic � analysis, classification, reasoning, synthesis and comparison of approaches � make it possible to identify and highlight key areas for improving the professional training of future teacher. Results. The study examines methods for developing students' competence, analyses the literature, determines the components of mathematics teacher competence, highlights the functions and levels of development, provides the structure of the highest levels of teacher professional competence, determines the content of professional competence of a future mathematics teacher, presents models for the development of methodological knowledge about the professional competence of students and improving educational culture, diagnoses problems, related to the professional competence of students. Conclusions. Professional development is an ongoing, cyclical process because professionalism requires continuous enhancement. The advancement of this process largely depends on an environment that encourages self-development. A key objective in the professional training of mathematics teachers is to cultivate professional competence. This competence reflects students' readiness to apply both theoretical and practical knowledge in science and education, as well as their ability to enhance and refine their qualifications. The study indicates that the professional competence of a future teacher encompasses several aspects: motivational, cognitive, operational, creative, and reflective. Keywords: mathematics teacher; educational process; quality of methodological training; methodological knowledge; methodological culture; professional competencies

Flock health planning: How to move from a plan to a reflective planning process in Northern Irish sheep flocks?

AbstractFlock health planning has been advocated as part of a wider drive within livestock production for veterinarians and farmers to adopt a prevention‐focused approach to veterinary medicine. This approach has, at its core, a cyclical process of assessment, evaluation, action and re‐assessment, and is documented, at least in summary, in a health plan (HP). The HP has become a defining pillar of farm quality assurance schemes (QASs), introduced to address calls for greater transparency and accountability in food production. There is limited current information on the attitudes and behaviours surrounding flock HPs in the sheep sector and the barriers to greater involvement in an active process of continual improvement through reflective flock health planning. This study aims to address these issues with reference to the national flock in Northern Ireland. A mixed‐methods approach was used to explore farmers' and veterinarians' opinions and behaviours related to QASs and HP, with data obtained through an online scoping questionnaire, semi‐structured interviews with 27 farmers and 15 veterinarians, and discussion groups with farmers and veterinarians. No evidence of a positive association between a farm having a HP and implementation of 12 industry‐recommended flock health activities was identified using the Fisher's exact test. Farmers reported a reluctance to pay for veterinary advice while some veterinarians reported a lack of time to develop HPs for farmers, and sheep‐related work generally. Farmers predominantly saw the HP as a static, physical document, which had limited impact on their management practices, rather than a proactive, reflective and collaborative planning process. Veterinarians tasked with completing HPs felt restricted by limited knowledge of on‐farm practices, flock production data and a lack of confidence in the accuracy of on‐farm medicine records. This led some to believe that the HPs may fail to address critical issues. A new approach to engage farmers and veterinarians together in active flock health planning needs to be developed. This will need a sustainable delivery plan. Then the focus can be shifted towards ongoing reflective health planning to drive change for the betterment of sheep health and welfare.

Robust ultrablack film deposited on large-curvature magnesium alloy by atomic layer deposition

A broadband absorber composed of a TiAlC/SiO2 film stack prepared by atomic layer deposition was presented, which could be uniformly coated on magnesium alloys with large curvature, achieving an average absorption as high as 99.4% within the wavelength range from 400 to 1000 nm. An Al2O3/TiO2 interlayer was deposited on magnesium alloys prior to the deposition of ultrablack films, which effectively prevented corrosion of magnesium caused by Al3+ and Cl− by-products in the TiAlC film. With the presence of this interlayer, the ultrablack film on the surface of the magnesium alloy exhibited good adhesion and abrasion resistance. Furthermore, after undergoing damp heat and thermal cycling tests, the absorptions of the ultrablack film-coated magnesium alloys remained at 99.1% and 99.0%, respectively, which indicated that the film is promising for application in precision optics under harsh environmental conditions.

From Siege to Survival: Exploring the Multi-Faceted Traumas of Meranao Internally Displaced Persons

The 2017 Marawi Siege in the southern Philippines resulted not only in a city’s physical devastation but also in a profound psychological impact on its internally displaced residents, mainly from the Meranao community. This research aims to understand the trauma endured by these Meranao IDPs, linking it with paradigms of forced migration, cultural displacement, and post-conflict collective memory. Using the American Psychiatric Association’s definition of trauma and Herman’s Trauma Theory as a guiding framework, six IDP survivors from the Sagonsongan area were interviewed. The study adopted the Interpretative Phenomenological Analysis (IPA) approach to explore the participants’ experiences. This qualitative method involves a detailed examination of personal lived experiences, attempting to understand how individuals make sense of their major life experiences. The IPA approach was particularly suitable for this study as it allowed the researchers to examine the personal stories of trauma, providing a rich and detailed first-person account of the psychological struggles faced by the Meranao IDPs. The data collection involved in-depth, semi-structured interviews that enabled the participants to share their stories in a flexible yet comprehensive manner. The interviews were transcribed verbatim and analyzed following the principles of IPA, which involve a cyclical process of reading and re-reading the transcripts, coding for themes, and looking for connections between themes across the different narratives. The researchers remained cognizant of their preconceptions and engaged in a reflective process to minimize bias. The findings revealed several themes, such as the traumatic implications of familial dislocation, economic hardships, persistent trauma, feelings of exhaustion, and a compromised sense of safety. These findings not only intersect with established theories but also provide unique insights into the Meranao community’s post-siege challenges. The trauma narratives contributed to a nuanced account of the Meranao IDPs’ psychological struggles after the siege. Keywords: Meranao community, internally displaced persons, Marawi Siege, trauma

Broadening the Discourse on Death Anxiety: Unexplored Dimensions and Holistic Perspectives

Understanding death anxiety among patients is crucial for healthcare professionals to provide personalized care and support strategies. Cultural and social norms play a significant role in shaping an individual's perception of death. While some cultures accept death as a natural and cyclical process, others tend to avoid it. Therefore, healthcare professionals must consider these factors to develop effective assistance strategies. This our discourse emphasizes the importance of comprehensively evaluating death anxiety to contribute to the study of Özpancar Şolpan et al. on this subject.

Electrodialysis for efficient antisolvent recovery in precipitation of critical metals and lithium-ion battery recycling

It has proven effective to recover metal compounds from aqueous mixtures by use of antisolvents; organic compounds that induce selective precipitation. A challenge with antisolvents is that they are both costly to produce and recover on an industrial scale. In recycling of lithium-ion batteries and recovering critical metals, we find that electrodialysis can be a competitive method for purifying and recycling antisolvents. In this study we investigate the use of electrodialysis to separate salt and water from a ternary solution of water, KCl and ethanol. A coupled non-equilibrium electrochemical model is developed to understand how such systems may be operated, designed, and which characteristics that are required for the ion exchange membranes. We demonstrate how the water transference coefficients of the membranes should be tuned in the process optimisation and why membrane property design is crucial to the success of this concept. Residual mixtures from antisolvent precipitation, with ethanol (EtOH) solvent weight fractions around 0.6-0.7, can be demineralised and the EtOH fraction increased by 0.1-0.2 at an energy requirement of 60-200 kWh mEtOH−3 by use of electrodialysis. In an example application of the concept, aqueous KCl is precipitated by recycled ethanol in a cyclic process, requiring 0.161 kWh molKCl−1. This example case considers complete ethanol rejection by the membranes and abundant water co-transport, characterised by the transference coefficients: tw=15 and ta=0 for water and EtOH respectively. The findings pave the way for new applications with aqueous mixtures of critical metals.

Enhancement of the Power-to-Heat Energy Conversion Process of a Thermal Energy Storage Cycle through the use of a Thermoelectric Heat Pump

The principal strategy for achieving a neutral climate entails enhancing the share of renewable energies in the energy mix, in conjunction with promoting innovation in efficient technologies. Thermal energy storage systems have the potential to efficiently handle the intermittent nature of renewable energy sources. Furthermore, these systems can effectively handle shifts in both heat and electrical demand. Thus, efficient power-to-heat technologies are needed to boost thermal energy storage. This manuscript explores the potential of utilising a thermoelectric heat pump system in conjunction with electric resistances for charging a thermal energy storage. In order to achieve elevated temperatures, the thermoelectric system integrates thermoelectric heat pump blocks in a two-stage configuration. Air has been employed as a heat transfer medium for sensible heat storage. Higher airflow rates improve the performance of thermoelectric heat pump system. Moreover, its impact on the optimal voltage supply of the thermoelectric system is observed when it is combined with an electric resistance to achieve elevated temperatures. In comparison to the basic charging process that solely relies on the electric resistance of a thermal energy storage at 120 °C, a significant 30 % increase in power-to-heat energy conversion has been achieved by including the thermoelectric heat pump system. In fact, it efficiently elevates the temperature from the initial ambient temperature of 25 °C to a remarkable 113.1 °C, achieving a coefficient of performance of 1.35 with an airflow rate of 23 m3/h. Therefore, the use of this technology to enhance a complete process of storing excess renewable energy in the form of heat for subsequent use in both heat and electricity through a combined heat and power cycle is demonstrated.

Controllable release of Cu ions contributes to the enhanced environmentally-friendly performance of antifouling Cu-bearing stainless steel coating prepared using high-velocity air fuel

Organic antifouling coatings represent an economical and efficient solution for addressing the marine biofouling. However, their application is constrained by issues of durability and toxicity. Therefore, this study has developed a metal-based antifouling coating by utilizing pre-alloyed copper-bearing stainless steel (Cu-bearing SS) powder in conjunction with high-velocity air fuel (HVAF) technology, aiming to achieve an environmentally-friendly and long-lasting antifouling coating. Compared to the self-polishing copolymer (SPC) coating, the adhesion strength of Cu-bearing SS coating increased to 69.0 MPa, which is approximately a 33-fold increase. The coating also exhibited enhanced wear resistance, the width and depth of the wear track for the Cu-bearing SS coating decreased 42.9 % and 81.0 %, respectively. Furthermore, the coating still demonstrated strong inhibitory effects on typical fouling microorganisms and algae adhesion due to Cu ions release process environmentally-friendly. The electrochemical techniques coupling with surface morphology observations were used to elucidate the antifouling mechanism. The variation trend of coating corrosion current was consistent with the release process of Cu ions, which was directly related to the evolution of the coating surface morphology. The three-stage change in the surface morphology of the 304 L-Cu SS coating contributes to the formation of a cyclic variation trend process of Cu ions. The evolution of surface morphology, accompanied by the controlled release process of Cu ions, had become a distinctive feature of antifouling properties for a metal-based coating.