The escalating impacts of global warming have raised concerns at local and global levels, necessitating urgent mitigation efforts, particularly among households in urban settings. However, limited information on household energy consumption and its associated carbon footprint may constrain effective climate mitigation and policy development in Bauchi metropolis. This study assessed household energy consumption in Bauchi metropolis to establish its carbon footprint and inform policy development amid evident climate change. The study adopted a descriptive survey approach involving questionnaires and observational field measurements using a weighing scale to establish the average unit weight of energy sources across six wards. A two stage sampling technique involving cluster and purposive sampling was adopted. Descriptive statistics and the Intergovernmental Panel on Climate Change (IPCC) guidelines were used to analyse the data and estimate the related carbon footprint. The result of 403 analysed responses revealed that the average annual carbon footprint from firewood, charcoal, grid electricity, LPG, petrol, diesel, kerosene, and sawdust was 6.61 tCO2 per household, with firewood and charcoal identified as priority areas for emission reduction. The study concluded that household energy consumption contributes to carbon emissions in the Bauchi metropolis and therefore recommends targeted interventions should reduce dependence on firewood and charcoal and promote cleaner household energy sources.
Offshore expansion of aquaculture is constrained by the prohibitive cost of subsea grid connection, making off-grid renewable generation an alternative to the diesel supply that currently dominates. This study addresses a fundamental question: is there an optimal renewable energy infrastructure suitable for universal deployment in offshore aquaculture, or must solutions be site-specific? A probabilistic decision-making framework incorporating influence diagrams, Markov chains, temporal modelling, investment cost forecasting, and five renewable energy infrastructure designs was evaluated against performance, environmental impact, and techno-economic criteria. Application to two Tasmanian case study sites revealed that multi-source renewable infrastructures outperformed single-source alternatives, yet different technology combinations proved optimal at each location (VAWT-PV-OWC at Bass Strait, HAWT-PV or HAWT at Storm Bay). Under equal criterion weighting, renewable alternatives scored 15–35% lower in utility than diesel generation, at a cost of valued energy approximately 9–14 times the diesel baseline on a 2030 forecast basis, but this ranking reversed once environmental weighting exceeded 37%, within the range of plausible stakeholder priorities. The site-specific rankings were unchanged across all 64 cost-parameter perturbation scenarios tested, indicating robustness to cost-forecast uncertainty. These findings demonstrate that effective renewable energy deployment for offshore aquaculture requires site-specific assessment rather than a one-size-fits-all approach, and provide a transferable methodology for conducting assessment.
Acrylamide and 5-hydroxymethylfurfural (5-HMF) are chemical process contaminants generated in black garlic through the Maillard reaction. Vacuum aging (16 kPa, 70–75 °C for 12 days) was introduced as a new aging technology to mitigate acrylamide and 5-HMF in black garlic. Results showed that vacuum aging suppressed the formation of acrylamide (from 2.86 μg/g to below the detection limit, i.e., 100% reduction) and 5-HMF (from 173.26 μg/g to 7.90 μg/g, i.e., 95.4% reduction) in black garlic due to the reduced thermal exposure. Vacuum aging inhibited the Maillard reaction, and resulted in the higher lightness (L = 22.14) and the lower browning degree (ΔE = 62.76) of black garlic than those (L = 15.16, ΔE = 69.47) prepared by conventional aging. The reduced thermal exposure also restrained the hydrolytic release of fructose, glucose, total polyphenols, and total flavonoids in vacuum-aged black garlic. It reduced them by 95.0%, 100%, 89.9%, and 91.8%, respectively, which in turn diminished its antioxidant capacity by 58.4% and 79.1% based on the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. These limitations of vacuum aging, including decreased antioxidant capacity together with sensorial quality reduction, require further process refinement in future work before this technology can be implemented for industrial-scale production of black garlic.
Due to their dense microstructure and excellent thickness controllability, copper films are widely utilized in flexible electronics and energy storage device systems. Their interfacial stability in electrochemical environments becomes the critical factor limiting device cycle life and safety. However, in fluorine-containing electrolyte environments, copper is susceptible to severe HF-induced corrosion, generating unstable products such as CuF2, which can lead to structural degradation and functional failure. The results indicated that the film with a low Zn content (Cu-Zn (9.5:0.5 wt%)) exhibited deteriorated corrosion resistance due to a significant micro-galvanic effect. Its corrosion current was as high as 6.87 × 10−5 mA·cm−2. By contrast, the high-Zn-content film (Cu-Zn (9:1 wt%)) formed a composite passivation film that increased charge transfer resistance to 1.22 × 104 Ω·cm2 and reduced the corrosion current to 2.08 × 10−5 mA·cm−2. The introduction of an additional carbon layer resulted in optimal stability of the Cu-Zn (9:1 wt%)@C composite film, with the corrosion current decreasing to 6.14 × 10−6 mA·cm−2 and the structure remaining intact after corrosion. Multi-scale characterization revealed that the addition of zinc to the alloy enhanced the film’s intrinsic passivation capability, while the carbon layer provided an external barrier effect through physical isolation, charge regulation, and stress relief. This synergy effectively suppressed the formation of by-products. In summary, the Cu-Zn (9:1 wt%)@C composite film demonstrated the greatest corrosion resistance, establishing a theoretical foundation and engineering approach for the design of highly stable metallic films for use in intricate electrochemical environments.
The long-term fire safety of steel structures necessitates fire-resistant (FR) steels with superior strength retention after prolonged exposure to elevated temperatures. This study investigates two FR steels with Mo contents of 0.25 wt.% and 0.50 wt.% (correspondingly adjusted Cr contents to maintain a nearly constant total Mo + Cr alloy level) after thermal exposure at 600 °C for up to 6 h. Both steels exhibit a polygonal ferrite (PF) and granular bainite (GB) microstructure, but with different phase fractions. Increasing Mo to 0.5 wt.% promotes bainite formation, resulting in a predominantly granular bainitic microstructure (88% GB and 12% PF). A multi-scale characterization reveals that the higher-Mo/lower-Cr design not only increases the fraction of GB but also dramatically enhances its thermal stability. Importantly, Mo suppresses the premature precipitation of coarse (Nb, Ti)(C, N) in the parent austenite, thereby retaining solutes for the subsequent precipitation of a high number density of fine carbides within the bainitic ferrite laths during thermal exposure. The combination of a high-density dislocation substructure within the stable GB and the strong precipitation strengthening from these dispersed nano-carbides is primarily responsible for the superior strength retention in the higher-Mo/lower-Cr FR3 steel. This steel maintains a high yield strength of 440 MPa after 6 h at 600 °C, which is 158 MPa higher than its 0.25 wt.% Mo counterpart and satisfies the international fire-resistance criterion (YS600 °C/YSRT > 2/3). This work provides a mechanistic basis for optimizing Mo–Cr alloy design to achieve exceptional long-term high-temperature performance in FR steels.
