Re-liquefying boil-off gas consumes 2.24 MW aboard a liquefied natural gas (LNG) carrier, and the nitrogen reverse Brayton cycle (N2RBC) used is limited by 32 °C seawater. No unified energy, exergy, economic and environmental (4E) assessment exists for an exhaust-driven ammonia-water absorption refrigeration cycle (ARC) coupled to such a plant, nor any marine costing basis. The two cycles are solved as one steady-state model against the unmodified seawater-intercooled plant, with three least-dependent criteria optimized simultaneously and TOPSIS, LINMAP and entropy weighting compared. Chilling the intercooler water to 5.3 °C lowers the compressor inlet from 37 to 10.3 °C and cuts specific energy consumption 8.8 percent, from 0.691 to 0.630 kWh per kilogram. Net auxiliary demand falls 198 kW and second-law efficiency rises from 30.70 to 33.68 percent, the absorption chiller yield cooling power 1.30 MW with two main engines 272 °C exhaust gas. Irreversibility in the nitrogen loop falls 12.6 percent, but the absorption subsystem adds more than it removes; that destruction is drawn from exhaust the baseline vents, carrying no fuel penalty. Moreover, land-based costs corrected for shipboard material, geometry, and installation yield absorption-plant capital from 1.37 million USD, against 1.50 million USD total incremental capital. For the economic viability, Discounted payback is 9.97 years at 8 percent over 20 years, internal rate of return 13.81 percent, and 869 tonnes of carbon dioxide are avoided annually. Last but not least, assessed for tropical service at 0.8 USD per kilogram of fuel over 7,224 operating hours per year, the retrofit loses its positive net present value if capital exceeds the estimate by more than 47 percent or fuel falls below 0.55 USD per kilogram.
This study systematically investigates the effect of CO2 activation duration (0-60 min at 900 °C) on electrospun polyacrylonitrile-derived carbon nanofibers (CNFs) for supercapacitor electrodes. The results reveal a nonlinear relationship between activation time and structural evolution. An intermediate duration of 50 min (CNF50) optimizes the microstructure, yielding the lowest ID/IG ratio, the highest sp2/sp3 carbon ratio, and a maximized microporous surface area of 658 m2 g−1. These characteristics enhance electrical conductivity and provide abundant ion-accessible sites. Consequently, the CNF50 electrode achieves a superior specific capacitance of 151.65 F g−1 at 0.5 A g−1, which represents a threefold improvement over non-activated CNFs. Furthermore, CNF50 demonstrates outstanding cycling stability, retaining 93.86
Mesenchymal stem cells (MSCs) exert immunomodulatory and regenerative effects primarily through their secretome, which comprises cytokines, growth factors, and extracellular vesicles. Although prolonged in vitro expansion has been reported to induce replicative senescence and alter MSC function, the functional consequences of passage-dependent changes in the MSC secretome remain incompletely characterized. In this study, we performed an integrated comparison of early- and late-passage MSC secretomes using THP-1 monocytic cells as an in vitro model to evaluate immunomodulatory and migratory responses. MSCs were characterized based on immunophenotype, proliferative capacity, and senescence-associated β-galactosidase activity. The biological effects of MSC secretomes on THP-1 cell viability, migration, and inflammatory responses were evaluated using MTT assays, chemotaxis assays, quantitative PCR, and ELISA. Early-passage MSC secretomes (EP-MSC-S) enhanced THP-1 cell viability, increased the expression of anti-inflammatory cytokines (IL-10 and TGF-β1), and reduced the transcript levels of pro-inflammatory mediators, including NF-κB, IL-1β, IL-6, and TNF-α. In contrast, late-passage MSC secretomes (LP-MSC-S) were associated with increased pro-inflammatory gene expression, enhanced migratory activity, and upregulation of CXCR4 and VEGF transcripts in THP-1 cells. Cytokine array profiling further demonstrated higher signal intensities of pro-inflammatory and chemotactic cytokines, including IL-1β, MCP-1, and MCP-2, in LP-MSC-S, whereas EP-MSC-S exhibited higher signal intensities of anti-inflammatory cytokines such as IL-4 and IL-13. Collectively, these findings provide functional evidence that MSC passage number is associated with coordinated changes in secretome composition and downstream immune and migratory responses in vitro. This study is limited by the use of an in vitro model, MSCs derived from a single donor, and gene-level pathway analysis without protein-level validation. Therefore, the findings should be interpreted as preliminary mechanistic associations that warrant further validation in multi-donor and in vivo models before translational applications can be considered. MSCs are known to influence immune responses mainly through the substances they release, known as the secretome. However, when MSCs are expanded in the laboratory for extended periods, they may undergo aging-related changes that could affect their biological properties. In this study, we compared secretomes obtained from early and late laboratory passages of MSCs using an in vitro immune cell model. We found that secretomes from early-passage MSCs were associated with a more anti-inflammatory profile, while those from late-passage MSCs showed features linked to increased inflammatory signaling and cell migration. These differences suggest that prolonged cell expansion may alter the functional characteristics of MSC secretomes. Because this study was conducted using a single donor and an in vitro model, the findings should be considered preliminary. Further research using multiple donors and more advanced models is needed to better understand how MSC passage number may influence their potential applications in immune-related conditions.
Coal is an abundant source of energy; however, the use of Pakistani coal is limited due to its high sulfur content, which causes environmental and health issues. Hence, pre-combustion desulfurization of coal is imperative for quality enhancement. The present study investigates the microbial desulfurization of coal from the Balochistan mine by using local bacterial strains, Bacillus pumilus and Bacillus licheniformis, isolated from the same coal mine, for their sustainability, adaptability, and local availability. Batch incubation experiments with a coal particle size of 75 and 150 µm and incubation periods of 7 and 14 days were conducted to evaluate the effect of particle size and incubation period on the sulfur removal efficiency. Proximate analysis was conducted in accordance with ASTM D3173, ASTM D3174, and ASTM D3175 to determine the moisture content (MC), ash content (AC), and volatile matter (VM), while ultimate analysis was performed using a CHNS analyzer. Additionally, XRD was used to determine changes in composition and structure before and after treatment. The results showed that microbial treatment increased calorific value, specifically at smaller particle sizes and longer incubation periods. The maximum sulfur removal achieved by B. licheniformis was 32.73
This study investigates the influence of niobium (Nb) on the heat-treatment behavior of multi-alloyed white cast iron containing 5 wt
