Recovery Techniques Research Articles

The thermal stability mechanism of MBA-crosslinked PPGs: Insights from macroscopic phenomena to chemical reactions

Preformed particle gels (PPGs) is one of the most efficient enhanced oil recovery techniques used for conformance control. Evaluating the thermal stability of PPGs and understanding their thermal stability mechanism are crucial for the development and application of high-temperature-resistant PPGs. We focused on conventional N, N′-methylene-bis-acrylamide (MBA) crosslinked PPGs, systematically analyzing the macroscopic state changes, microstructural changes, and chemical reactions occurring during the ageing process in 1 % NaCl solution at different temperatures, and delved into their thermal stability mechanism. Our findings revealed that the swelling ratio (SR) of PPGs during ageing is correlated with temperature, showing three distinct patterns: a stable SR at low temperatures (<60 °C), a period of unchanged swelling followed by a continuous increase within the intermediate temperature range (70–90 °C), and a rapid swelling leading to sol conversion at high temperatures (>95 °C). Scanning electron microscope observations and elastic modulus analysis confirmed that the microstructure of PPGs remains stable when the SR was unchanged, while continuous increases in the SR indicated damage to the gel's micro-network structure. X-ray photoelectron spectrum and carbon nuclear magnetic resonance spectroscopy indicated that no chemical reactions occurred in PPGs at temperatures not exceeding 60 °C. When temperature was 70–100 °C, a small amount of acrylamide (AM) hydrolysis occurred initially, which then sequentially triggered the hydrolysis of MBA crosslinkers and 2-Acrylamido-2-methylpropane sulfonic acid (AMPS) due to the catalytic effect of undissociated carboxyl. At temperatures above 100 °C, hydrolysis reactions occurred simultaneously in AM, MBA crosslinkers, and AMPS. The thermal stability of MBA-crosslinked PPGs is indeed related to the thermal stability of the MBA, but it can be reduced by the influence of other non-temperature-resistant monomers, such as AM. This study provides insights into the thermal stability mechanisms of PPGs and guidance for the development of high-temperature-resistant PPGs.

A Comparative study on novel active cooling and heat recovery techniques for photovoltaic-thermal collectors

In this study, four different cooling techniques with a variety type of coolant for a commercial photovoltaic-thermal collector have been simulated optically and thermally by using the discrete ordinate radiation model (DO) and compared in a hot climate. These methods include a cooling channel with lateral inlet and outlet (case II), a cooling channel with uniquely designed fins (case III), a channel with circular inlet and many elliptical outlets patterns (case IV), and a specific pattern of copper tubes containing water beneath the solar module (case V), in comparison with a standard PV module (case I). The cooling fluids utilized in this research consist of dry air, moist air with relative humidity of 20 %, 40 %, and 60 %, and water in an active cooling method. The results indicate that using fins and copper pipes reduces the temperature, respectively, by 12 °C and 23 °C, leading to 4.10 % and 7.92 % improvement in electrical efficiency, which corresponds to a power improvement of 4.12 % and 7.98 % in cases III and V. In comparison, in cases II and IV, temperature reductions were only 6.5 °C and 9 °C, respectively, leading to a smaller improvement in efficiency of 2.20 % and 4.10 % in both scenarios where no fins are present. Consequently, the shape of the inlet and outlet, along with the distribution of air inside the channel, influences the cooling performance of the solar module significantly. It is observed that in cases II, III, and IV, by increasing the relative humidity of the incoming air to 60 % with an inlet velocity of 1 m/s, the electrical efficiency improves approximately 4.21 %, 5.5 %, and 4.91 %, respectively, compared to Case I.

CHEF-K, a hybrid technique for early recovery in complex tibial plateau fractures: a case report

CHEF-K, a hybrid technique for early recovery in complex tibial plateau fractures: a case report

Donation After Circulatory Death Cardiac Recovery Technique: Single-Center Observational Outcomes

BackgroundRecovery of hearts from donation after circulatory death donors has been performed either with direct procurement and perfusion (DPP) using the TransMedics Organ Care System or with normothermic regional perfusion (NRP) with subsequent cold storage. It remains unclear which of these 2 strategies yields optimal posttransplant outcomes. MethodsAll heart transplant recipients from donors after circulatory death donors at the Vanderbilt University Medical Center (Nashville, TN) were reviewed (February 2020 to January 2023). Recipients were stratified into an NRP or DPP cohort. All DPP recoveries were performed using the TransMedics Organ Care System. The key outcome was severe primary graft dysfunction at 24 hours, defined by the need for postoperative extracorporeal membrane oxygenation. ResultsA total of 118 hearts were transplanted (NRP, 87; DPP, 31). Donors recovered using NRP were younger (25 years [interquartile range {IQR}, 21-31 years] vs 31 years [IQR, 24-37 years]; P = .008) and had shorter distance traveled (292 miles [158-516 miles] vs 449 miles [IQR, 248-635 miles]; P = .02). Recipient preoperative risk factors were similar between the groups. There was no difference in the incidence of severe primary graft dysfunction at 24 hours (NRP, 5.8%; and DPP, 12.9%; P = .24). However, ejection fraction at 7 days after transplantation was higher in the NRP group (65% [IQR, 60%-65%] vs 60% [IQR, 60%-68%]; P = .005). There was no difference in inotrope scores at 24 hours (P = 1.00) or 72 hours (P = .87) or in 30-day (NRP, 95% vs DPP, 97%; P = .75) and 1-year (NRP, 94% vs DPP, 86%; P = .19) survival. ConclusionsNRP and DPP strategies for recovery of cardiac allografts yield comparable early allograft outcomes. Future studies are needed to confirm these findings in larger prospective cohorts.

To Stick or Not to Stick? Studying the Impact of Offset Recovery Techniques During Mid-Air Interactions.

During mid-air interactions, common approaches (such as the god-object method) typically rely on visually constraining the user's avatar to avoid visual interpenetrations with the virtual environment in the absence of kinesthetic feedback. This paper explores two methods which influence how the position mismatch (positional offset) between users' real and virtual hands is recovered when releasing the contact with virtual objects. The first method (sticky) constrains the user's virtual hand until the mismatch is recovered, while the second method (unsticky) employs an adaptive offset recovery method. In the first study, we explored the effect of positional offset and of motion alteration on users' behavioral adjustments and users' perception. In a second study, we evaluated variations in the sense of embodiment and the preference between the two control laws. Overall, both methods presented similar results in terms of performance and accuracy, yet, positional offsets strongly impacted motion profiles and users' performance. Both methods also resulted in comparable levels of embodiment. Finally, participants usually expressed strong preferences toward one of the two methods, but these choices were individual-specific and did not appear to be correlated solely with characteristics external to the individuals. Taken together, these results highlight the relevance of exploring the customization of motion control algorithms for avatars.

Performance Analysis of Lake Water Cooling Coupled with a Waste Heat Recovery System in the Data Center

Data centers (DCs) require continuous cooling throughout the year and produce a large amount of low-grade waste heat. Free cooling and waste heat recovery techniques are promising approaches to reduce DC energy consumption. Although previous studies have explored diverse waste heat utilization strategies, there is a significant gap in combining waste heat recovery with lake water cooling in DCs. Therefore, this study proposed a system integrating lake water cooling with waste heat recovery for DCs. To evaluate the energy-saving performance of the suggested system, the influence of waste heat recovery locations and volumes has been investigated. An analysis of the improvement in system parameters is also conducted. The study’s findings highlight that targeted recovery of waste heat from sources like chilled water or air in server rooms can significantly reduce the cooling energy demand of the system. The results show that recovering heat from the return air of IT equipment can yield a remarkable power usage effectiveness (PUE) and coefficient of performance (COP) of 1.19 and 10.17, and the energy consumption of the cooling system is reduced to 10.06%. Moreover, the outcomes reveal the potential for substantial energy savings of up to 26.05% within the proposed system by setting the chilled water and air supply temperatures to 16 and 20 °C, respectively.

A novel approach for missing data recovery and fault nodes detection in wireless sensor networks

SummaryEnsuring data integrity in wireless sensor networks (WSNs) is crucial for accurate monitoring, yet missing data due to sensor faults present a significant challenge. This research introduces an innovative approach that integrates advanced data recovery techniques with leading‐edge methods to address this issue. The system begins by identifying and isolating fault nodes using a specialized algorithm that analyzes network behavior. By applying fuzzy density‐based spatial clustering of applications with noise (FDBSCAN), potential fault nodes are precisely located based on deviations from expected patterns. Subsequently, an intelligent missing data recovery mechanism powered by bidirectional long short‐term memory (Bi‐LSTM) networks takes action. The Bi‐LSTM model is trained on existing sensor data to capture intricate patterns and dependencies, enabling accurate prediction and reconstruction of missing values caused by identified faults. The synergy between Bi‐LSTM for missing data recovery and FDBSCAN for fault node detection comprehensively addresses the missing data problem in WSNs. In missing data recovery, it demonstrates low mean absolute deviation (MAD) ranging from 0.021 to 0.13 and mean squared deviation (MSD) ranging from 0.0025 to 0.05 across various missing data ratios. Data reliability remains consistently high at 96% to 98%, even with up to 80% missing data. For fault node detection, the approach achieves precision of 95.7%, recall of 96.3%, F1‐score of 96.1%, and accuracy of 97.4%, outperforming existing techniques. The computational cost during training is noted at 5.79 h, presenting a limitation compared to other methods. This research highlights the importance of integrating fault node detection into missing data recovery mechanisms, presenting an innovative solution for the advancement of WSNs.

Waste heat recovery from a green ammonia production plant by Kalina and vapour absorption refrigeration cycles: A comparative energy, exergy, environmental and economic analysis

The production of green ammonia involves significant energy penalties due to heat losses. Recovering this heat can enhance the sustainability of ammonia production. However, this area remains largely unexplored, making it unclear which approach to waste heat recovery is best suited. Therefore, this paper investigates two methods of waste heat recovery in a green ammonia production plant: the Kalina Cycle (KC) and the Vapour Absorption Refrigeration Cycle (VARC). The underlying processes are simulated, and an analysis is conducted covering energy, exergy, environmental, and economic aspects. The results show that integrating the system with KC yields a marginal energy efficiency improvement of about 1%. However, when the conventional ammonia production system is integrated with VARC, the improvement in energy efficiency reaches 8%, while exergy efficiency improves by 11%. An environmental assessment estimates the greenhouse gas emissions saved by each heat recovery method, revealing that VARC achieves almost four times the emission savings compared to KC. Economically, integrating KC increases the levelized cost of ammonia (LCOA) by over 18%, whereas adding VARC has almost no impact on the LCOA. Overall, the co-production of refrigeration using VARC is identified as a superior heat recovery technique for green ammonia plants.

The role of nanoparticle–surfactant interactions in air-stabilized foams used for improving oil recovery

Foam flooding, an emerging tertiary oil recovery technique, demonstrates efficacy as a conformance control method in enhanced oil recovery. Conformance control mitigates injected displacement fluid channeling and bypassing, improving macroscopic sweep efficiency. Generated foamed films preferentially enter high permeability zones, diverting subsequent injection into unswept lower permeability regions. Nanoparticle-reinforced foams exhibit consistent bulk stability and effective residual oil mobilization. This work utilizes dynamic foam analysis to probe the synergistic effects of zinc oxide nanoparticles and anionic surfactant on foam generation and persistence. Bulk and local scale foam stability is evaluated under various potassium chloride concentrations. Optimal foam stability occurs near the critical micelle concentration of the surfactant at 2,500 ppm. Increasing electrolyte concentration within a fixed surfactant formulation decreases foam stability due to salt-induced micellar swelling. An optimized electrolyte and nanoparticles with a surfactant combination produce high-quality foam with increased bubble density per unit area. Micellar swelling by nanoparticle adsorption inhibits lamellae thinning and liquid drainage. Enhanced foam properties improve microscopic displacement efficiency and mobility control in foam-assisted oil recovery. Oil recovery is increased by approximately 22% compared to conventional waterflooding.

Robust image tamper detection and recovery with self-embedding watermarking using SPIHT and LDPC

In today’s digital landscape, the pervasive use of digital images across diverse domains has led to growing concerns regarding their authenticity and reliability. The potential for malicious manipulation of these images underscores the critical need to develop robust methods for detecting tampering and ensuring their integrity. Fragile watermarking has been found to have extensive applications for tamper detection and recovery. An image watermarking technique for tamper detection, correction, and recovery is presented in this study. The proposed method employs a self-embedding method to generate the reference watermark from the original image, which has the advantage of superior tamper detection, localization, recovery capabilities, and robustness against attacks. Set Partitioning in the Hierarchical Tree (SPIHT) algorithm is applied to generate a reference watermark of the original image. Low-Density Parity Check (LDPC) is employed for error correction, providing higher-quality reconstruction to recover the original image. Schur decomposition processed the watermarked image blocks to generate authentication bits for each block to enhance tampering detection. The proposed watermarking method was evaluated using PSNR, SSIM, BER, and NC metrics for grayscale and colored images. The technique demonstrated high robustness in tamper detection and recovery against various malicious attacks. Comparative analysis with existing methods shows the efficacy of the proposed method.

Advancements in Surfactant Carriers for Enhanced Oil Recovery: Mechanisms, Challenges, and Opportunities.

Enhanced oil recovery (EOR) techniques are crucial for maximizing the extraction of residual oil from mature reservoirs. This review explores the latest advancements in surfactant carriers for EOR, focusing on their mechanisms, challenges, and opportunities. We delve into the role of inorganic nanoparticles, carbon materials, polymers and polymeric surfactants, and supramolecular systems, highlighting their interactions with reservoir rocks and their potential to improve oil recovery rates. The discussion includes the formulation and behavior of nanofluids, the impact of surfactant adsorption on different rock types, and innovative approaches using environmentally friendly materials. Notably, the use of metal oxide nanoparticles, carbon nanotubes, graphene derivatives, and polymeric surfacants and the development of supramolecular complexes for managing surfacant delivery are examined. We address the need for further research to optimize these technologies and overcome current limitations, emphasizing the importance of sustainable and economically viable EOR methods. This review aims to provide a comprehensive understanding of the emerging trends and future directions in surfactant carriers for EOR.

Utilizing cost-effective pyrocarbon for highly efficient gold retrieval from e-waste leachate

Addressing burdens of electronic waste (E-waste) leachate while achieving sustainable and selective recovery of noble metals, such as gold, is highly demanded due to its limited supply and escalating prices. Here we demonstrate an environmentally-benign and practical approach for gold recovery from E-waste leachate using alginate-derived pyrocarbon sorbent. The sorbent demonstrates potent gold recovery performance compared to most previously reported advanced sorbents, showcasing high recovery capacity of 2829.7 mg g−1, high efficiency (>99.5%), remarkable selectivity (Kd ~ 3.1 × 108 mL g−1), and robust anti-interference capabilities within environmentally relevant contexts. The aromatic structures of pyrocarbon serve as crucial electrons sources, enabling a hydroxylation process that simultaneously generates electrons and phenolic hydroxyls for the reduction of gold ions. Our investigations further uncover a “stepwise” nucleation mechanism, in which gold ions are reduced as intermediate gold-chlorine clusters, facilitating rapid reduction process by lowering energy barriers from 1.08 to −21.84 eV. Technoeconomic analysis demonstrates its economic viability with an input-output ratio as high as 1370%. Our protocol obviates the necessity for organic reagents whilst obtaining 23.96 karats gold product from real-world central processing units (CPUs) leachates. This work introduces a green sorption technique for gold recovery, emphasizing its role in promoting a circular economy and environmental sustainability.

Evaluation of the Teaching Recovery Techniques intervention among newcomer students in Swedish schools: a randomised controlled trial turned into a feasibility study

BackgroundDuring recent years, Europe has faced the arrival of migrants whereof a considerable group of youth present mental health problems, such as symptoms of post-traumatic stress disorder (PTSD). Schools offer a safe environment for mental health interventions to these groups, yet there is limited research on the impact of school-based interventions addressing mental health problems in newcomer youths, especially in the Swedish context. This cluster randomized controlled trial (RCT) aimed to explore the effectiveness of the Teaching Recovery Techniques (TRT) intervention among newcomer students with PTSD symptoms in Swedish secondary schools.MethodsNine schools were randomly assigned to TRT or a wait list control group prior to the baseline assessment. Follow-up data were collected immediately following the intervention and three months post-intervention. In total, 531 students were approached, of which 61 gave consent and were eligible to be included in the study: 55 in TRT and 6 in the control condition. Given the low number of participants in the control condition, we merely analyzed students who had received TRT.ResultsWe report on feasibility of recruitment, data collection, intervention delivery and intervention effectiveness. In terms of intervention effectiveness, within subjects ANOVAs revealed significant reductions in PTSD symptoms and general mental health problems from baseline to the three months-follow-up (p < 0.001).ConclusionsOur results indicate that TRT is a promising school-based intervention for newcomer students with PTSD symptoms. For a successful implementation of TRT in the school context, schools need to be engaged and the implementation should be managed by a local coordinator.Trial registrationISRCTN, ISRCTN48178969, Retrospectively registered 20/12/2019.

A novel closed-loop biotechnology for recovery of cobalt from a lithium-ion battery active cathode material.

In recent years, the demand for lithium-ion batteries (LIBs) has been increasing rapidly. Conventional recycling strategies (based on pyro- and hydrometallurgy) are damaging for the environment and more sustainable methods need to be developed. Bioleaching is a promising environmentally friendly approach that uses microorganisms to solubilize metals. However, a bioleaching-based technology has not yet been applied to recover valuable metals from waste LIBs on an industrial scale. A series of experiments was performed to improve metal recovery rates from an active cathode material (LiCoO2; LCO). (i) Direct bioleaching of ≤0.5 % LCO with two prokaryotic acidophilic consortia achieved >80 % Co and 90 % Li extraction. Significantly lower metal recovery rates were obtained at 30 °C than at 45 °C. (ii) In contrast, during direct bioleaching of 3 % LCO with consortia adapted to elevated LCO levels, the 30 °C consortium performed significantly better than the 45 °C consortium, solubilizing 73 and 93 % of the Co and Li, respectively, during one-step bioleaching, and 83 and 99 % of the Co and Li, respectively, during a two-step process. (iii) The adapted 30°C consortium was used for indirect leaching in a low-waste closed-loop system (with 10 % LCO). The process involved generation of sulfuric acid in an acid-generating bioreactor (AGB), 2-3 week leaching of LCO with the biogenic acid (pH 0.9), selective precipitation of Co as hydroxide, and recirculation of the metal-free liquor back into the AGB. In total, 58.2 % Co and 100 % Li were solubilized in seven phases, and >99.9 % of the dissolved Co was recovered after each phase as a high-purity Co hydroxide. Additionally, Co nanoparticles were generated from the obtained Co-rich leachates, using Desulfovibrio alaskensis, and Co electrowinning was optimized as an alternative recovery technique, yielding high recovery rates (91.1 and 73.6% on carbon felt and roughened steel, respectively) from bioleachates that contained significantly lower Co concentrations than industrial hydrometallurgical liquors. The closed-loop system was highly dominated by the mixotrophic archaeon Ferroplasma and sulfur-oxidizing bacteria Acidithiobacillus caldus and Acidithiobacillus thiooxidans. The developed system achieved high metal recovery rates and provided high-purity solid products suitable for a battery supply chain, while minimizing waste production and the inhibitory effects of elevated concentrations of dissolved metals on the leaching prokaryotes. The system is suitable for scale-up applications and has the potential to be adapted to different battery chemistries.

Hydrogen bonding-based deep eutectic solvents for choline chloride/sulfamide and its application in the recycling of precious metals

The depletion of natural resources for precious metals is occurring as the economy expands, and conventional recovery techniques often involve the use of hazardous reagents. We have successfully developed a novel deep eutectic solvent, choline chloride/sulfamide, which exhibits exceptional efficiency in forming a highly effective deep eutectic dissolution reagent with dibromohydantoin for the efficient recovery of precious metals. The acidity provided by sulfamide and the oxygen negative ions generated by choline chloride jointly initiate an attack on the N-Br bond in dibromohydantoin. Bromine radicals and Br2 together promote the oxidation of precious metals. The Cl- and Br- ions form complexes to generate AuCl2Br2-, which effectively stabilizes the Au3+ species in solution. Under optimal reaction conditions, Au0 can be completely dissolved within 25 minutes. The average rate of gold dissolution in this DES dissolution reagent was 10,235.9 mg Au/(h·mol DBD), which is more than 200 times the average rate of gold dissolution in conventional cyanide. Moreover, DES dissolution reagent allows for recycling of the precious metal up to 6 times with dissolution rates consistently above 95 %. By adding it into an oxalic acid solution, the gold complex can be reduced to Au0 to achieve recycling of precious metals.

Cardiac magnetic resonance findings in cardiac amyloidosis.

The purpose of this review is to highlight the increasing importance of cardiac magnetic resonance (CMR) imaging in diagnosing and managing cardiac amyloidosis, especially given the recent advancements in treatment options. This review emphasizes the crucial role of late gadolinium enhancement (LGE) with phase-sensitive inversion recovery (PSIR) techniques in both diagnosing and predicting patient outcomes in cardiac amyloidosis. The review also explores promising new techniques for diagnosing early-stage disease, such as native T1 mapping and ECV quantification. Additionally, it delves into experimental techniques like diffusion tensor imaging, MR elastography, and spectroscopy. This review underscores CMR as a powerful tool for diagnosing cardiac amyloidosis, assessing risk factors, and monitoring treatment response. While LGE imaging remains the current best practice for diagnosis, emerging techniques such as T1 mapping and ECV quantification offer promise for improved detection, particularly in early stages of the disease. This has significant implications for patient management as newer therapeutic options become available for cardiac amyloidosis.

Techno-economic, techno-environmental assessments, and deep learning optimization of an integrated system for CO2 capturing from a gas turbine: Tehran case study

This study investigates methods to reduce heat losses, CO2 emissions, and improve the overall efficiency of micro gas turbine power plants, considering economic viability as gas turbines are a major component of the global energy supply chain. Heat recovery and carbon capture techniques were employed to achieve these goals. First, a steam Rankine cycle and a greenhouse were designed to integrate with an existing micro gas turbine. Second, the entire system was simulated using thermodynamic, economic, and environmental models. Finally, an optimization process was conducted through a machine learning model using the integrated model. By adding a Rankine cycle, 80 % of the heat losses in a traditional power plant were recovered, converted into electricity and cooling, and resulted in a 3 % efficiency improvement. Additionally, implementing a CO2 separation and capture unit with utilization in a nearby greenhouse not only enhanced greenhouse profitability but also significantly reduced CO2 emissions into the atmosphere. While the system's cost rate increased by $40/hour, the investment payback period is only 0.97 years. Furthermore, CO2 emission rate was reduced by 15 %.

Integrated catalytic systems for simultaneous NOx and PM reduction: a comprehensive evaluation of synergistic performance and combustion waste energy utilization.

The global transition towards sustainable automotive vehicles has driven the demand for energy-efficient internal combustion engines with advanced aftertreatment systems capable of reducing nitrogen oxides (NOx) and particulate matter (PM) emissions. This comprehensive review explores the latest advancements in aftertreatment technologies, focusing on the synergistic integration of in-cylinder combustion strategies, such as low-temperature combustion (LTC), with post-combustion purification systems. Selective catalytic reduction (SCR), lean NOx traps (LNT), and diesel particulate filters (DPF) are critically examined, highlighting novel catalyst formulations and system configurations that enhance low-temperature performance and durability. The review also investigates the potential of energy conversion and recovery techniques, including thermoelectric generators and organic Rankine cycles, to harness waste heat from the exhaust and improve overall system efficiency. By analyzing the complex interactions between engine operating parameters, combustion kinetics, and emission formation, this study provides valuable insights into the optimization of integrated LTC-aftertreatment systems. Furthermore, the review emphasizes the importance of considering real-world driving conditions and transient operation in the development and evaluation of these technologies. The findings presented in this article lay the foundation for future research efforts aimed at overcoming the limitations of current aftertreatment systems and achieving superior emission reduction performance in advanced combustion engines, ultimately contributing to the development of sustainable and efficient automotive technologies.

A novel hybrid enhanced oil recovery technique to enhance oil production from oil-wet carbonate reservoirs by combining electrical heating with nanofluid flooding

Enhanced Oil Recovery provides a promising technique to maximise fossil fuel recovery from existing resources, and when used in conjunction with Carbon Capture and Storage/Utilisation provides a way to support a transition to alternative cleaner fuels. A hybrid Enhanced Oil Recovery method by a combination of electrical heating and nanofluid flooding was applied to oil-wet carbonate reservoirs and assessed in terms of the oil production, zeta potential, contact angle, pellet compaction, interfacial tension, and pH values. The hybrid technique consisted of a combination of direct current (up to 30 V) and iron oxide (Fe2O3) or magnesium oxide (MgO) nanofluids. Both nanofluids were injected into oil-wet Austin chalk – our laboratory model of an oil-wet carbonate reservoir – and then electrical heating was started, or vice versa. Introducing electrical heating first increased oil recovery by up to 27% in seawater compared to 16% in deionised water. When Fe2O3 nanofluid was injected, oil recovery further increased to 32% in seawater and 24% in deionised water. The contact angle and zeta potential decreased from 124° to 36° and from −24.4 to −23.7 mV, respectively, when nanofluid was injected in seawater, leading to better nanofluid stability and penetration into the carbonate rock as shown by increased pellet porosity from 6.6% to 14.8%. Moreover, it was found that the interfacial tension was reduced from 72 to 32.7 mN/m in the pre-magnetised samples with Fe2O3 NPs injection compared to 33.2 mN/m in the samples with MgO injection. It was found from our experiments that the effect of the generated electricity on the surface charge was of a temporary nature as the zeta potential of the rock returned to its original value as soon as the power was disconnected. The mechanism underlying the hybrid Enhanced Oil Recovery EOR technique from the laboratory findings was found to be based on electrowetting and nanofluid adsorption. Results indicate that the technique is promising for further improving oil recovery and securing energy supply during the transition to net zero.

Unveiling Mechanistic Insight into Accelerating Oxygen Molecule Activation by Oxygen Defects in Co3O4-x/g-C3N4 p-n Heterojunction for Efficient Photo-Assisted Uranium Extraction from Seawater.

Photo-assisted uranium extraction from seawater (UES) is regarded as an efficient technique for uranium resource recovery, yet it currently faces many challenges, such as issues like biofouling resistance, low charge separation efficiency, slow carrier transfer, and a lack of active sites. Based on addressing the above challenges, a novel oxygen-deficient Co3O4-x/g-C3N4 p-n heterojunction is developed for efficient photo-assisted uranium extraction from seawater. Relying on the defect-coupling heterojunction synergistic effect, the redistribution of molecular charge density formed the built-in electric field as revealed by DFT calculations, significantly enhancing the separation efficiency of carriers and accelerating their migration rate. Notably, oxygen vacancies served as capture sites for oxygen, effectively promoting the generation of reactive oxygen species (ROS), thereby significantly improving the photo-assisted uranium extraction performance and antibacterial activity. Thus, under simulated sunlight irradiation with no sacrificial reagent added, Co3O4-x/g-C3N4 extracted a high uranium extraction amount of 1.08mgg-1 from 25 L of natural seawater after 7 days, which is superior to most reported carbon nitride-based photocatalysts. This study elaborates on the important role of surface defects and inerface engineering strategies in enhancing photocatalytic performance, providing a new approach to the development and design of uranium extraction material from seawater.