Product Layer Research Articles

An efficient molten steel slag gas quenching process: Integrating carbon solidification and waste heat recovery

The iron and steel-making industries have garnered significant attention in research related to low-carbon transitions and the reuse of steel slag. This industry is known for its high carbon emissions and the substantial amount of steel slag it generates. To address these challenges, a waste heat recovery process route has been developed for molten steel slag, which integrates CO2 capture and fixation as well as efficient utilization of steel slag. This process involves the use of lime kiln flue gas from the steel plant as the gas quenching agent, thereby mitigating carbon emissions and facilitating carbonation conversion of steel slag while simultaneously recovering waste heat. The established carbonation model of steel slag reveals that the insufficient diffusion of CO2 gas molecules within the product layer is the underlying mechanism hindering the carbonation performance of steel slag. This finding forms the basis for enhancing the carbonation performance of steel slag. The results of Aspen Plus simulation indicate that 1 t of steel slag (with a carbonation conversion rate of 15.169 %) can fix 55.19 kg of CO2, process 6.08 kmol of flue gas (with a carbon capture rate of 92.733 %), and recover 2.04 GJ of heat, 0.43 GJ of exergy, and 0.68 MWh of operating cost. These findings contribute to the development of sustainable and efficient solutions for steel slag management, with potential applications in the steel production industry and other relevant fields.

Corrosion behavior of TiN monolayer and CrN/TiN multilayer coatings: Impact of immersion time and saline solution type

AbstractThe corrosion behavior of the TiN monolayer and CrN/TiN multilayer coatings deposited via cathodic arc evaporation physical vapor deposition (CAE‐PVD) on the Ti–6Al–4V substrates were evaluated in Ringer's and Hank's physiological saline electrolytes. XRD (x‐ray diffractometry) and scanning electron microscopy (SEM) analysis were used to characterize the coatings. The corrosion behavior of coatings was assessed by impedance spectroscopy and potentiodynamic polarization techniques. The results showed that the corrosion resistance of coatings was increased in the order of TiN‐Ringer's < TiN‐Hank's < CrN/TiN‐Ringer's < CrN/TiN‐Hank's. Therefore, it can be concluded that the CrN/TiN coating, due to having a large number of interfaces and a smoother surface with fewer macroparticles and pinholes, is more efficient in raising the corrosion resistance properties of titanium than TiN monolayer coating. Moreover, it was observed that Ringer's solution is a more severe environment than Hank's solution. Both coatings, because of the precipitation of a protective corrosion products layer on their surface, showed an enhancement in corrosion resistance with increasing the immersion time from 1 to 14 days in Hank's. The results suggest TiN monolayer and CrN/TiN multilayer coatings as promising candidates for biomedical applications.

Role of layer arrangement in microstructure and corrosion behavior for 78-mm thick-plate 316L stainless steel fabricated via narrow gap laser wire filling welding

Controlling repeated thermal cycling is one of the key mechanisms to design microstructures in the interlayer regions for narrow gap laser wire filling welding (NGLWFW) of austenite stainless steels. Herein, the optimization of process parameters for individual layers is tailored to customize the molten pool morphology during the NGLWFW process, facilitating precise control over the microstructure and, consequently, enhancing both mechanical properties and corrosion resistance of the joint. The results showed that the molten pool morphology acquired by simulation are obviously diverse from the bottom zone (BZ), middle zone (MZ) to upper zone (UZ) of the welded joint ascribed to the high heat accumulation effect, leading to the variation of microstructure. At BZ, the combination of smaller grain size and reduced dendrite spacing reduce the number of corrosion sites and promote the formation of a denser and more uniform corrosion product layer. Additionally, the diverse grain orientation, characterized by lower texture strength, facilitated a more uniform distribution of elements. Furthermore, the significantly higher content of δ-ferrite showing smallish shape disrupted the directional growth of austenite columnar grains, contributing to the excellent corrosion resistance observed at the BZ.

Adsorption kinetics and inhibition mechanisms of a film-forming amine on carbon steel surfaces

In the present study, the inhibition mechanisms and the adsorption kinetics of a film-forming amine (N-oleyl-1,3-propanediamine, OLDA) were investigated on a carbon steel surface in various corrosive environments, relevant to industrial water/steam circuits. In situ electrochemical characterizations including Electrochemical Impedance Spectroscopy (EIS) and polarization curves were combined with ex situ surface analysis, such as Polarization Modulation Infrared Reflection Absorption Spectroscopy (PM-IRRAS) and Raman Spectroscopy. OLDA acts as a mixed inhibitor for all the studied conditions. In a deaerated medium, OLDA adsorption is temperature-independent (25 °C–50 °C) and PM-IRRAS analyses reveal the formation of a monolayer (thickness of about 1.6 nm) on the steel surface. In aerated media, mixed OLDA/corrosion products layers are formed exceeding the monolayer thickness (about 20 nm). Finally, the presence of a well-defined time constant in the high frequency range in impedance spectra is correlated with the accumulation of OLDA molecules with corrosion products.

Age-related changes in the mitochondrial, synthesis of steroids, and cellular homeostasis of the chicken ovary

In poultry reproduction, the decline of ovarian function due to aging is related to dysfunction of mitochondria exacerbated by a reduction in antioxidant capacity, ultimately leading to follicle atresia and decreased egg production. However, the mechanisms of mitochondrial dysfunction in the chicken ovary in aging have remained to be understood. Hence, this study aims to investigate the effects of aging on mitochondrial function and cellular homeostasis. We collect ovarian tissue, small white follicles (SWF), large white follicles (LWF), and small yellow follicles (SYF) from three different laying periods of hens. The transmission electron microscopy (TEM) results showed that mitochondrial damage occurred in ovarian tissue during the late laying period (LP), characterized by structural swelling, scattered mitochondrial cristae, and an increase in the vacuoles. At the same time, with age, the synthesis of steroid hormones in the ovaries and follicular tissues is reduced. The levels of autophagy and cell apoptosis in ovarian tissues were both increased in the LP. In addition, aging adversely impacts mitochondrial function, leading to a decrease in mitochondrial unfolded protein response (UPRmt) functions. This study will expand the knowledge about regressing ovarian aging in hens and increasing egg production in older layers for poultry production.

Organismal trade-offs and the pace of planktonic life.

No one is perfect, and organisms that perform well in some habitat or with respect to some tasks, do so at the cost of performance in others: there are inescapable trade-offs. Organismal trade-offs govern the structure and function of ecosystems and attempts to demonstrate and quantify trade-offs have therefore been an important goal for ecologists. In addition, trade-offs are a key component in trait-based ecosystem models. Here, I synthesise evidence of trade-offs in plankton organisms, from bacteria to zooplankton, and show how a slow-fast gradient in life histories emerges. I focus on trade-offs related to the main components of an organism's Darwinian fitness, that is resource acquisition, survival, and propagation. All consumers need to balance the need to eat without being eaten, and diurnal vertical migration, where zooplankton hide at depth during the day to avoid visual predators but at the cost of missed feeding opportunities in the productive surface layer, is probably the best documented result of this trade-off. However, there are many other more subtle but equally important behaviours that similarly are the result of an optimisation of these trade-offs. Most plankton groups have also developed more explicit defence mechanisms, such as toxin production or evasive behaviours that are harnessed in the presence of their predators; the costs of these have often proved difficult to quantify or even demonstrate, partly because they only materialise under natural conditions. Finally, all multicellular organisms must allocate time and resources among growth, reproduction, and maintenance (e.g. protein turnover and DNA repair), and mate finding may compromise both survival and feeding. The combined effects of all these trade-offs is the emergence of a slow-fast gradient in the pace-of-life, likely the most fundamental principle for the organisation of organismal life histories. This crystallisation of trade-offs may offer a path to further simplification of trait-based models of marine ecosystems.

Atmospheric corrosion of AISI‐1020 carbon steel in a very aggressive coastal zone of Havana, Cuba. Determination of corrosivity category using three ways of assessment

AbstractThe Cuban coastal line is reported to be one of the most aggressive in the world. Three ways to estimate corrosivity category of the atmosphere were considered. The influence of meteorological parameters on chloride deposition rate in saline solution form was considered as a first way. Corrosion rate calculated by dose response function is considered a second way. It was confirmed that atmospheric corrosion of AISI‐1020 carbon steel is influenced by and in salt solution form. A critical level from which could increase was estimated. The presence of typical crystalline phases of carbon steel confirmed that formation mechanism led to cracking of the corrosion products layer. It justified the increase of rcorr as a function of time until reaching a very high (C5) corrosivity category as the third assessment way. was predicted up to 20 years of exposure. A correspondence between the three assessment ways existed.

Biodegradable high-nitrogen iron alloy anastomotic staples: In vitro and in vivo studies

For gastrointestinal anastomosis, metallic biodegradable staples have a broad application potential. However, both magnesium and zinc alloys have relatively low strength to withstand the repeated peristalsis of the gastrointestinal tract. In this study, we developed a novel kind of biodegradable high-nitrogen iron (HN–Fe) alloy wires (0.23 mm), which were fabricated into the staples. The tensile results showed that the ultimate tensile strength and elongation of HN–Fe wires were 1023.2 MPa and 51.0 %, respectively, which was much higher than those of other biodegradable wires. The degradation rate in vitro of HN–Fe wires was slightly higher than that of pure Fe wires. After 28 days of immersion, the tensile strength of HN–Fe wires remained not less than 240 MPa, meeting the clinical requirements. Furthermore, sixteen rabbits were enrolled to conduct a comparison experiment using HN–Fe and clinical Ti staples for gastroanastomosis. After 6 months of implantation, a homogeneous degradation product layer on HN–Fe staples was observed and no fracture occurred. The degradation rate of HN–Fe staples in vivo was significantly higher than that in vitro, and they were expected to be completely degraded in 2 years. Meanwhile, both benign cutting and closure performance of HN–Fe staples ensured that all the animals did not experience hemorrhage and anastomotic fistula during the observation. The anastomosis site healed without histopathological change, inflammatory reaction and abnormal blood routine and biochemistry, demonstrating good biocompatibility of HN–Fe staples. Thereby, the favorable performance makes the HN–Fe staples developed in this work a promising candidate for gastrointestinal anastomosis.

Preparatory study for carbon sequestration modelling of agroforestry systems in Hungary: The assessment of the yield class distribution of windbreaks

The escalating carbon dioxide emissions leading to global climate change are acknowledged as a paramount environmental challenge in the twenty-first century. The significance of land use systems in stabilising carbon dioxide levels and enhancing carbon sink potential has gained noteworthy attention from both the scientific and political communities. The Intergovernmental Panel on Climate Change emphasises that agroforestry systems present vital prospects for synergising climate change adaptation and mitigation efforts, offering substantial technical mitigation potential. Windbreaks are well-known agroforestry systems in Hungary and form an important part of agricultural landscapes. The improved agroforestry subsidy system in our country makes it relevant to model the carbon sequestration potential of windbreaks. In the framework of the ForestLab project we plan to develop a carbon sequestration model specific for Hungarian agroforestry systems. In this study, as a preparatory step of the model development, we assessed the yield class distribution of Hungarian windbreaks by tree species group and identified variables that had significant effect on yield class based on the data of the National Forestry Database. Our results show that among the examined effects the most important predictor of the yield class of windbreaks was the tree species group, followed by the thickness of the productive soil layer and the hydrology of the site.

Influence of rolling reduction on corrosion behavior of WE43 alloy

The corrosion behavior of WE43 alloy with different rolling reductions (0%, 25%, 45%, and 80%) at 500 °C was investigated in 3.5 wt.% NaCl solution. The microstructure evolution of the rolled WE43 alloy was characterized in detail by means of optical microscopy (OM), transmission electron microscopy (TEM) and electron back-scattered diffraction (EBSD). The results show that with increasing reductions, basal texture is gradually enhanced and grain size gradually decreases. Only the alloy with 45% reduction exhibits dispersed dynamic precipitates. Immersion and electrochemical measurements demonstrate the decreasing order of the corrosion resistance of the rolled WE43 alloy: 45% reduction > 80% reduction > 25% reduction > 0 reduction. The best corrosion resistance of the WE43 alloy with 45% reduction is mainly related to a large number of finely dispersed precipitates, which are capable of promoting the formation of a compact corrosion product layer. The increased corrosion rate of the sample with 80% reduction is induced by the re-solution of the majority of precipitates into the matrix. The grain size, basal texture and deformation twins have a limited effect on the corrosion resistance of rolled WE43 alloy compared with the precipitates.

Some issues in reactive wetting at high temperatures described by reaction product control theory

The phenomenon of reactive wetting at high temperature and its special issues are systematically discussed, focusing on the wetting behavior in metal/metal and metal/ceramic systems. Especially, based on the reaction product control (RPC) theory, the influence of wetting mechanism, spreading dynamics and interfacial reactivity on wettability and interfacial structure is deeply analyzed. The limitations of the classical RPC model under certain conditions are pointed out. In the ultra-fast spreading systems, the spreading dynamics cannot satisfy the prediction of RPC model, which is related to the formation of chemical bonds at the solid/liquid interface. Among them, the Gibbs free energy of the interface reaction does not directly point to the difference of wettability, but is reflected in the thickness of the reaction product layer. The greater the absolute value of Gibbs free energy of interface reaction, the thicker the thickness of precipitation layer. The mechanism leading to wetting is not always consistent with the spreading dynamics, the former is related to the bonding properties, and the latter is related to the slowest link leading to spreading.

Comparative study on the corrosion behavior of two arc spraying coatings in simulated marine environments

The corrosion behaviors of arc spraying 5083Al and Zn15Al coatings in a simulated marine environment were comparatively analyzed. The 5083Al coating exhibited lower corrosion rates and higher polarization resistance than the Zn15Al coating. Due to the lower solubility and higher supersaturation of Al(OH)3, the corrosion products of 5083Al coating presents a faster deposition rate and causes a denser and blocky corrosion products layer, which inhibits the penetration of Cl−, thereby enhancing corrosion resistances. Furthermore, in the case of coating cracking, the 5083Al coating, with lower potentials than EH36 steel matrix and lower self-discharge rate than the Zn15Al coating, acting as the sacrificial anode, is more suitable to provide durable protection for steels in marine environments.

Feasibility analysis of commingle production of multi-layer reservoirs in the high water cut stage of oilfield development

Multi-layer commingle production is a common development technique to improve the overall oil recovery of multi-layer reservoirs. However, this technique is mainly used at low water cut stage. Research on this technique at high water cut stage is comparatively few. Therefore, in order to improve productivity and recovery of wells, feasibility analysis of commingle production of multi-layer reservoirs in the high water cut stage is analyzed. To achieve a good commingle production result, the production layers must be optimized and inter-layer interference must be analyzed and reduced as much as possible. Factors, such as permeability, porosity, viscosity, capillary pressure, gravity, pressure difference, and water cut difference, have impact on commingle production. But it is difficult to consider all these factors. Therefore, according to the geological reservoir characteristics of X Oilfield, a model is established to simulate commingle production process, and the results are compared and analyzed. The interference degree is characterized by seepage resistance. The commingle production effect is evaluated by dimensionless oil increase coefficient, production index, and production index interference coefficient. The results show that the larger the difference of permeability ratio and water cut between multi-layers, the more severe the interlayer interference; dimensionless oil increase coefficients are all positive, it means that commingle production can achieve good oil increase effect even in the high water cut stage; the recommended technical limits for commingle production are that: permeability ratio is less than 5; commingle production timing is that water cut of low permeability layer is higher than 80%. This technique has been applied to X Oilfield, and the oil recovery increased about 2.8%, which confirmed this method feasibility.

In-situ oxidation for selective lithium extraction from spent LiFePO4 cathodes by low acid dosage

Recovery of lithium from spent lithium iron phosphate batteries is crucial to alleviating the storage of lithium. This study proposes a method for the selective recovery of lithium from spent lithium iron phosphate battery cathodes using a leaching system of H2SO4 and H2O2. Efficient and selective lithium recovery was achieved through in-situ oxidation of lithium iron phosphate driven by a low acid dosage, and the mechanism of selective lithium recovery was investigated by precipitation experiments of Fe2+ and PO43−. The shrinking core model was used for the kinetic analysis of the leaching process, and the results suggested that the leaching process was controlled by the internal diffusion of the product layer. Moreover, essential leaching parameters such as acid concentration, H2SO4 dosage, H2O2 dosage, leaching time, and leaching temperature were systematically investigated. The results showed that the leaching rate of Li reached 97.95 % along with a selectivity of 99.60 %, which meets the standard of the battery-grade Li2CO3, while the leaching rate of both Fe and P was less than 1 %.

Protective Properties of Calcareous Deposit Layer for Cathodically Polarized AH36 Steel in Natural Seawater

A calcareous deposit is a by-product of the cathodic polarization in seawater environments. This study presents the results of evaluating the anticorrosion and anti-macro-biofouling effectiveness of a calcareous deposit layer on the surface of the cathodically polarized AH36 structural steel in tropical seawater. The polarization is induced with initial current densities at which the calcareous deposit layer formed with both aragonite and brucite for 12 months continuously. The protective properties of the layer were compared with those of the passive layer from corrosion products under the same environmental conditions. The macro-biofouling in the tropical seawater is observed in the closed and open surfaces of the steel. The comparison of the anticorrosion property shows that, to some degree, the calcareous deposit layer contributes to surface passivation, as in the case of the corrosion product layer. In addition, the composition of the brucite and aragonite in the calcareous layer in the study plays a role as a macro-biofouling growth-limiting factor.

The role of water vapour on CO2 mobility on calcite surface during carbonation process for calcium looping: A DFT study

The presence of water vapour has been proven to stimulate carbonation for the calcium looping process, while its effect mechanism during the slow reaction stage still lacks insight understanding at the atomic level, where H2O molecules may interact with the product layer to affect the transportation of CO2. This study tried to reveal the role of water vapour on CO2 mobility on the calcite surface through density functional theoretical (DFT) calculation. H2O molecule has higher adherence to calcite surface than CO2, and it can react with CO3 to generate HCO3− and OH− ions. Then, the formed OH− ion above the surface layer can adsorb CO2. Moreover, H2O can also react with O2− defect to form OH− ions, and the OH ion at the deeper position can still adsorb CO2 through a two-step process with remarkable energy barriers. However, the formation of HCO3− can degrade the energy barriers to CO2 release from the calcite surface, owning to the weaker CO bond. Two directions of CO2 movement between anions were involved in this investigation, including crossing through the surface layer to the second layer and the movement inside the surface layer, where the higher mobility of CO2 from HCO3− to O2− ion occurs in both movement directions. For the case inside the surface layer, the movement from O2− ion to HCO3− has a higher energy barrier, indicating that the stimulation by H2O is a one-way effect, and the enhancement by H2O for CO2 mobility is caused by the reaction with CO32− other than O2− ion.

A Human–Machine Interaction Mechanism: Additive Manufacturing for Industry 5.0—Design and Management

Industry 5.0 is an emerging value-driven manufacturing model in which human–machine interface-oriented intelligent manufacturing is one of the core concepts. Based on the theoretical human–cyber–physical system (HCPS), a reference framework for human–machine collaborative additive manufacturing for Industry 5.0 is proposed. This framework establishes a three-level product–economy–ecology model and explains the basic concept of human–machine collaborative additive manufacturing by considering the intrinsic characteristics and functional evolution of additive manufacturing technology. Key enabling technologies for product development process design are discussed, including the Internet of Things (IoT), artificial intelligence (AI), digital twin (DT) technology, extended reality, and intelligent materials. Additionally, the typical applications of human–machine collaborative additive manufacturing in the product, economic, and ecological layers are discussed, including personalized product design, interactive manufacturing, human–machine interaction (HMI) technology for the process chain, collaborative design, distributed manufacturing, and energy conservation and emission reductions. By developing the theory of the HCPS, for the first time its core concepts, key technologies, and typical scenarios are systematically elaborated to promote the transformation of additive manufacturing towards the Industry 5.0 paradigm of human–machine collaboration and to better meet the personalized needs of users.

Cracking the dynamic code of the deep: Unexpected seasonal patterns of active protistan-bacterial microbiomes in the mesopelagic zone of the South China Sea

Disentangling microbial dynamics in the mesopelagic zone is crucial due to its role in processing sinking photic production, affecting carbon export to the deep ocean. The relative importance of photic zone processes versus local biogeochemical conditions in mesopelagic microbial dynamics, especially seasonal dynamics, is largely unknown. We employed rRNA gene transcript-based high-throughput sequencing on 189 samples collected from both the photic and mesopelagic zones, along with seasonal observations, to understand the South China Sea’s protistan-bacterial microbiota diversity, drivers, and mechanisms. Mesopelagic communities displayed unexpectedly greater seasonal but less vertical dynamics than photic counterparts. Temperature, dissolved oxygen, nutrients, and bacterial abundance drove mesopelagic communities vertically. Photic zone processes (using net community production and mixed layer depth as proxies) of past seasons, coinciding with strong monsoon periods, shaped seasonal fluctuations in mesopelagic communities, indicating a time-lag effect. Furthermore, certain microbes were identified as indicators for beta diversity by depth and season. This investigation deepens our understanding of how and why mesopelagic communities vary with season and depth. Recognizing the time-lagged effect of photic zone processes on mesopelagic communities is crucial for understanding the current and future configurations of the ocean microbiome, especially in the context of climate change and its effect on carbon export and ocean storage.

Release of lead, copper, zinc from the initial corrosion of brass water meter in drinking water: Influences of solution composition and electrochemical characterization

Corrosion of brass plumbing materials may lead to metal release and deteriorate the drinking water quality. In this study, the initial corrosion of brass coupon cut from commercially available water meter was investigated. High rates of Pb, Cu and Zn release from the brass coupon were found during the early stage of corrosion (0–5 d) due to general corrosion and galvanic corrosion. The corrosion current density (Icorr) increased and resistance (RF) decreased during this period indicating that severe corrosion had occurred. In a later stage (5–30 d), a decreased Icorr and an increased RF were observed due to the development of a denser layer of Pb and Cu corrosion products which regulated the release of soluble Pb and Cu. The release of Zn continued and no significant Zn precipitation was found. Overall, particulate Pb, particulate Cu and soluble Zn dominated in the metal release during the initial corrosion of brass. The release of Pb, Cu and Zn was enhanced by a lower pH. Free chlorine was found to slightly reduce the release of Pb but promote the release of Cu and Zn. The presence of Pb on the brass surfaces was found to alleviate the dezincification process. A conceptual model based on metal release profile and electrochemical characterization was proposed to describe the initial corrosion of brass in typical drinking water.

LiF-Rich Solid Electrolyte Interphase Formation by Establishing Sacrificial Layer on the Separator.

The formation of a stable solid electrolyte interphase (SEI) layer is crucial for enhancing the safety and lifespan of Li metal batteries. Fundamentally, a homogeneous Li+ behavior by controlling the chemical reaction at the anode/electrolyte interface is the key to establishing a stable SEI layer. However, due to the highly reactive nature of Li metal anodes (LMAs), controlling the movement of Li+ at the anode/electrolyte interface remains challenging. Here, an advanced approach is proposed for coating a sacrificial layer called fluorinated self-assembled monolayer (FSL) on a boehmite-coated polyethylene (BPE) separator to form a stable SEI layer. By leveraging the strong affinity between the fluorine functional group and Li+, the rapid formation of a LiF-rich SEI layer in the cell production and early cycling stage is facilitated. This initial stable SEI formation promotes the subsequent homogeneous Li+ flux, thereby improving the LMA stability and yielding an enhanced battery lifespan. Further, the mechanism behind the stable SEI layer generation by controlling the Li+ dynamics through the FSL-treated BPE separator is comprehensively verified. Overall, this research offers significant contributions to the energy storage field by addressing challenges associated with LMAs, thus highlighting the importance of interfacial control in achieving a stable SEI layer.