Teesside University

• Modelling commitment in a two-stage optional Prisoner’s Dilemma game. • Optionality boosts commitment but fails to sustain cooperation, leading to exit. • A strict rule boosts cooperation by closing an ‘opportunistic exit’ loophole. • Flexible rules may yield higher social welfare when exit options are beneficial. • Guides the institutional design to maximise both cooperation and social welfare. Commitment is a well-established mechanism for fostering cooperation in human society and multi-agent systems, while most research on commitment-based cooperation assumes compulsory participation. This overlooks many real-world scenarios where individuals are free to abstain from an interaction. We address this gap by proposing a two-stage evolutionary game model that integrates commitment with the optional Prisoner’s Dilemma. In our model, players first decide whether to commit and then choose to cooperate, defect, or exit. We find that optional participation boosts commitment acceptance but fails to foster cooperation, leading instead to widespread exit behaviour. To address this, we compare two institutional incentives: a strict rule rewarding only committed cooperators, and a flexible rule rewarding any committed non-defector. Results show that the strict rule is better for promoting cooperation, as the flexible rule creates a loophole for opportunistic exits. However, the flexible rule can yield higher social welfare when exit options are highly beneficial. Our study highlights the need for well-designed incentives in voluntary settings to effectively promote both cooperation and social welfare.

• Large nutrient exports are infrequent and short-lived depending on heavy rainfalls. • Heavy rainfalls regulate nutrient and ion concentrations by a dilution effect. • Effluent water quality varies seasonally as controlled by climatic factors. • The pond assures particle retention but fails to treat soluble components. • Downstream aquatic communities are subject to harmful effects year-round. Peatlands are important stores of carbon and nutrients, but drainage for peat extraction disrupts hydrology and water quality, enhancing leaching of organic matter and nutrients. This study examined the seasonal dynamics of water quality from a 16.4 ha industrial cutaway peatland catchment in Ireland following storm events and evaluated the influence of an on-site sedimentation pond. Water quality, including carbon, nitrogen and major ions, was monitored over three years using automated storm-event sampling, grab sampling and continuous flow measurements to assess seasonal variability, pond treatment effects and relationships with climatic drivers (flow and temperature). High flows (≥25 L/s) were infrequent, whereas low flows (≤5 L/s) were common. Carbon and nitrogen concentrations varied markedly between storm events, with increasing flow generally causing dilution. Despite their rarity, short-lived high flows accounted for a large proportion (>70–85%) of annual nutrient export. Effluent water quality exhibited clear seasonal patterns and was strongly related to flow and temperature. Warm, dry periods produced more neutral, nutrient-rich effluents, whereas colder, wetter conditions generated more acidic waters with lower concentrations, regulated by pH. Oxygen availability within the catchment appeared to influence carbon production in effluents concurrently with ammonia production. The pond received subsurface inflows low in dissolved oxygen and exhibited highly variable hydraulic retention times (mean ± standard deviation 90 ± 551 days; median 15 days). While the pond retained particulate material, its influence on dissolved constituents was limited. These effluents pose risks to receiving waters, highlighting the need for improved mitigation strategies in extracted peatland catchments.

Business performance in financial institutions remains uneven across emerging economies, despite sustained investments in strategic planning and reform initiatives. Attention has increasingly shifted from strategy formulation to execution, yet empirical evidence on how strategy implementation shapes organisational performance in developing financial systems remains limited. This study examines the relationship between strategy implementation and business performance in Nigerian financial institutions, using Wema Bank Plc as an empirical case. Drawing on goal-setting theory and the resource- based view, strategy implementation is operationalised through five core dimensions: strategic leadership, organisational structure alignment, communication clarity, resource allocation, and technology integration. A quantitative survey design was adopted, with data collected from 270 employees across selected branches in Lagos State. Descriptive statistics and regression analysis were used to assess the impact of strategy implementation on business performance. Findings indicate that strategy implementation has a statistically significant positive effect on business performance, with all five dimensions showing strong explanatory power. The study reinforces the centrality of execution in strategic management and offers evidence-based insights for managers seeking to translate strategic intent into measurable organisational outcomes within financial institutions.

Gas condensate banking can significantly reduce near-well gas productivity by as much as ~60% in tight gas reservoirs. Existing treatment techniques are resource demanding and could alter the reservoir structure permanently. This study investigates the effectiveness of enhanced electrokinetic oil recovery (EK-EOR) as a low-impact alternative for treating condensate banks. Using compositional reservoir simulation (CMG GEM), the influence of key reservoir and operational parameters—porosity, permeability, producer well location (i, j), injection rate, and injection pressure—on cumulative gas production (CGP) was examined. A Box–Behnken design of experiments was employed to generate 62 simulation runs, and a proxy model was developed to approximate full-field responses. Statistical validation showed strong model fidelity (R2 = 0.99, AAPE = 2.2%). The proxy was then optimized using a genetic algorithm (GA) to identify conditions that maximize gas recovery. Results indicate that lower injection rates and lower injection pressures maximize CGP through enhanced electro-osmotic flow and reduced water blocking, achieving a peak cumulative gas of 4.06 × 108 ft3. A secondary optimum at high injection pressure could be attributed to re-pressurization and partial re-vaporization of condensate near the wellbore. Reservoir quality also exerted a strong control: higher permeability and moderate porosity favoured gas yield, while optimal producer placement near the reservoir boundary increased drainage efficiency. This study demonstrates a systematic optimization framework combining design of experiments, proxy modelling, and evolutionary algorithms to evaluate EK-EOR performance.

The long-term reliability and performance of photovoltaic (PV) modules largely depend on the thermal stability and durability of encapsulation materials that protect solar cells from environmental and thermal degradation. Ethylene–vinyl acetate (EVA) is widely used as a solar cell encapsulant due to its excellent optical and mechanical properties; however, its thermal stability and resistance to degradation remain critical challenges under prolonged operating conditions. Although EVA-based nanocomposites have been investigated for solar cell encapsulation, limited studies have systematically examined how different nanoclay fillers and processing conditions influence the thermal stability and encapsulation efficiency of EVA materials. This study aims to optimize the thermal stability of EVA nanocomposites by incorporating different inorganic fillers mica, montmorillonite (MMT), and vermiculite, at varying concentrations and milling cycles. An 8% EVA solution was prepared and blended with these fillers to evaluate their effects on the thermal and structural properties of the nanocomposite materials. Thermal characterization using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) revealed noticeable changes in melting temperature, glass transition temperature, and thermal degradation behavior. The incorporation of nanofillers improved the thermal stability of the EVA matrix and influenced its crystallinity and mechanical properties. The optimized EVA nanocomposite demonstrated enhanced thermal resistance and improved durability compared with neat EVA, although a slight reduction in encapsulation efficiency was observed. These findings provide valuable insights into the formulation and optimization of EVA nanocomposites for solar cell encapsulation, contributing to the development of more thermally stable and durable encapsulation materials for sustainable photovoltaic applications.

The treatment of pain in the prehospital setting is suboptimal. The scope of paramedic practice is broadening, with more medicines becoming available to these professionals, including ketamine for pain management. A systematic literature review was carried out to examine the safety and efficacy of ketamine for adult trauma in a prehospital setting and its suitability for paramedics working outside an enhanced care scope of practice. Ketamine is effective in hypovolaemic patients and a preferred option for critically ill and hypotensive patients; it is particularly effective in alleviating trauma-based pain when used with opiates such as morphine or fentanyl. Side effects are rare and easily managed. Ketamine is a safe and effective addition to prehospital analgesia for adult trauma patients and safe for paramedics working outside an enhanced care scope of practice to administer. Advancing paramedics' understanding of the co-administration of ketamine and morphine versus ketamine alone would support decision-making in trauma-based patient.