Journals
2026 EN
Tennant Richard K. · Kuloyo Olukayode · Moody Andrew G.
+8 more
Global demand for renewable energy continues to rise, highlighting the importance of renewable natural gas asa sustainable alternative to fossil fuels. Anaerobic digestion (AD) is a proven, scalable technology for producing biogas, yet its efficiency depends on stable microbial communities operating under suitable temperature regimes. This study evaluates the effect of lowering operating temperatures in pilot‐scale digesters on gas yields, digestate chemistry, and microbial dynamics. Six continuously stirred tank reactors are acclimated at 55°C before three are gradually reduced to 48°C, while three remain at 55°C. Over a 60‐day period, methane yields do not significantly differ between the two treatments, averaging 140 l CH 4 kg −1 VS at 48°C and 125 l CH 4 kg −1 VS at 55°C, with biomethane composition stable at 54%. Metagenomic analyses reveal higher microbial diversity and functional redundancy at 48°C, with greater representation of methanogenic taxa such as Methanocelleus . In contrast, communities at 55°C show reduced diversity and dominance by thermophilic taxa. These results suggest that lowering AD operating temperatures may enhance microbial resilience without compromising methane production. Reduced energy input for heating at 48°C also offers potential operational and environmental benefits, which may improve commercial viability, subject to site‐specific factors and further validation of large‐scale AD facilities.
Journals
2026 EN
Inayat Muhammad · Abbas Farzana · HafeezurRehman Muhammad
+4 more
ABSTRACT The current study assessed the impact of organic and inorganic feeding management on water quality, growth performance and plankton communities in a pond‐based polyculture system over 9 months, using three treatments: Ctrl (C), organic feeding (T1) and inorganic feeding (T2). Significant differences were observed in electrical conductivity (EC) and total dissolved solids (TDS), with inorganic feeding showing the highest EC (1719.95 ± 41.05 µS/cm, p = 0.0017) and TDS (884.80 ± 4.90 mg/L, p = 0.0122), while other water parameters such as DO, pH and temperature showed no significant variation ( p > 0.05). In terms of growth, grass carp in organic feeding showed the highest weight gain (1264.0 ± 5.0 g) and specific growth rate (2.31 ± 0.01%/day), significantly higher than inorganic feeding (1089.4 ± 1.6 g, p < 0.0001). The overall gross yield was also highest in organic feeding (238,506.5 ± 29,668.4 g/ha, p < 0.0001). Phytoplankton and zooplankton diversity and abundance were significantly greater in organic feeding, with total densities of 31,224.0 ± 145.0 and 16,485.0 ± 524.0 cells/mL, respectively ( p < 0.001). Proximate composition revealed significant improvements in organic feeding fish for protein (e.g., grass carp: 22.19 ± 0.79%, p < 0.0001), fat, ash and moisture content. Organoleptic evaluation also favored organic feeding, showing significantly better texture (8.16 ± 0.22), flavour (8.43 ± 0.26) and overall acceptability (8.01 ± 0.20) compared to organic and inorganic feeding management ( p < 0.0001). These findings suggest that organic feeding management (organic feeding) improves water quality (excluding EC and TDS), enhances fish growth, promotes richer plankton communities and improves fish nutrition.
Journals
2026 EN
Hossain Meskat · Islam Degonto · Masum Zobaer
+5 more
ABSTRACT Coastal communities in Bangladesh face significant challenges due to long‐term salinity intrusion, leading to economic vulnerability and environmental stress. The remarkable adaptability of mud crabs to saline environments has encouraged coastal farmers to transition from shrimp aquaculture to mud crab fattening as an adaptive strategy. However, the sustainability of this practice is challenged by the overexploitation of wild seed, elevated mortality rates, suboptimal stocking densities and lack of standardized hatchery‐produced crablets. Therefore, the present study aimed to evaluate the growth performance and survival of juvenile mud crabs ( Scylla olivacea ) reared at three different stocking densities (2, 4 and 6 crab/m 2 ) randomly allocated in triplicate earthen grow‐out ponds over a 90‐day culture period. Hatchery‐reared juvenile mud crabs (1.78 ± 0.18 g) were stocked into 80 m 2 earthen ponds, where Nypa palm ( Nypa fruticans ) leaves were used as shelters covering 30% of the pond area. Survival rate, growth performance and key physicochemical parameters were monitored throughout the culture period. Principal component analysis (PCA) was also done to explain other factors that may influence the growth performance of crabs during culture. Crabs were fed once daily in southwestern areas with experimentally formulated feed with 45% protein. The findings revealed that stocking density significantly affected ( p < 0.05) the survival rate. Crablets stocked at 2 and 4 crab/m 2 had a significantly ( p < 0.05) higher final mean weight than crablets stocked at 6 crab/m 2 . Crabs reared at a moderate stocking density (4 crab/m 2 ) demonstrated higher yields than other treatments. Stocking with 6 crab/m 2 exhibited the higher number of deformed crabs. These results indicate that a stocking density of 4 crab/m 2 is recommended for the grow‐out of S. olivacea crablets in earthen ponds. Optimal stocking density will provide scientific basis to enhance production efficiency, reduce mortality and promote sustainable mud crab aquaculture in Bangladesh.
Journals
2026 EN
Rakotonaivo Miarisoa Lalaina · Ranaivomanana Lala N. J. · Gough Charlotte
+4 more
ABSTRACT The status of most fish stocks in Madagascar remains poorly documented. Given their importance for food security and livelihoods, it is necessary to define management measures with reliable data. This study applied a length‐based Bayesian biomass (LBB) estimation method for analysing the fisheries' representative length‐frequency data of seven most commonly caught coral reef fish species in the southwest of Madagascar. Using Froese's indicators, the use ofB B 0$\frac{B B_0 ;$ as a stock status indicator, allows a consistent comparison among species in multi‐gear, multi‐species fisheries and provides a practical basis for management advice in data‐limited contexts. The stock status was determined based on median estimates for the period 2018–2023, which provide an assessment of the overall status. Estimates for 2023 were used to describe the most recent status of the stocks. The outputs of this study provide a guide for fisheries managers, coastal communities and authorities to formulate effective management strategies for the sustainability of the marine fisheries in Madagascar. A key recommendation from the study is the need for fisheries managers to improve fisheries data and to periodically monitor biological indicators to assess the status of small‐scale fisheries stocks.
Journals
2026 EN
Tanaka Takuya · Koyanagi Hirosato · Ehara Takumi
+6 more
ABSTRACT Aggregation‐induced emission luminogens (AIEgens) are typically large π‐conjugated molecules, but their low affinity and noninvasiveness toward analytes limit practical applications. To address this, smaller, more planar AIEgens are needed. Stilbene, though structurally suitable, lacks visible luminescence. Here, we report a minimally modified stilbene‐based AIEgen—4‐dipropylamino‐4’‐cyano‐bridged stilbene ( DpCBS[7] )—that exhibits fluorescence solvatochromism and efficient AIE across a broad polarity range in the visible region. DpCBS[7] exhibits low quantum yields ( Φ fl = 0.01–0.04) in solvents from nonpolar n ‐hexane to polar dimethyl sulfoxide, with large Stokes shifts, viscosity‐sensitive luminescence, and highly efficient solid‐state luminescence ( Φ fl = 0.70). To elucidate its dual solvatochromic and AIE behavior, femtosecond transient absorption spectroscopy was conducted. In solution, DpCBS[7] displays transient absorption with lifetimes of 21 ps (toluene) and 56 ps (acetonitrile) at 293 K, indicating ultrafast nonradiative decay leading to low Φ fl . Arrhenius analysis over the temperature range of 263–313 K revealed activation energies (Δ E a ) of 9.90 kJ/mol in toluene and 12.8 kJ/mol in acetonitrile for the S 1 → S 0 decay of DpCBS[7] . The Δ E a values show no clear systematic dependence on solvent polarity. In contrast, pre‐exponential factor A remains consistently high regardless of solvent polarity, indicating that the striking photophysical response is governed primarily by the pre‐exponential factor rather than by modulation of the activation energy. These findings highlight the fundamental importance of tailoring the distribution function through structural modification as a robust strategy to control AIE characteristics.
Journals
2026 EN
Li Xiaoning · Yang Lin · Ye Hu
+7 more
Abstract The extensive use and insufficient recycling of polyethylene terephthalate (PET) create environmental and resource challenges. Alkaline hydrolysis offers a sustainable approach to degrade PET into terephthalic acid (TPA) for high‐value metal–organic frameworks (MOFs), yet mass transfer limitations hinder efficiency. Here, we pioneer the application of high‐shear reactors (HSR) to enhance hydrolysis through intense shear stress and turbulence. Benefiting from higher rotor speed and narrower shear gap, PET flakes are fragmented into smaller particles with surface microstructures, significantly increasing specific surface area and ester group exposure, which leads to a 2.4‐fold increase in degradation compared to high‐speed stirring. Ethanol‐induced PET swelling and turbulence‐driven surface renewal synergistically enhance OH − /COO − interaction, enabling 98.6% PET degradation in 8 min (5.00 wt.% NaOH). Recycled TPA is used to synthesize UiO‐66, which has applicability in carbon dioxide adsorption. This work establishes a rapid, efficient pathway for transforming waste PET into functional materials, advancing circular economy practices.
Journals
2026 EN
Liu Zhihao · Li Yan · Tian Jumei
+7 more
Abstract Metal‐support interaction (MSI) imposes significant influences on the performance of CO 2 methanation; however, its precise regulation remains confusing. Herein, we design two Ni cooperated with mesoporous TUD‐1 catalysts differing in strength of MSI to investigate the relationship between their structure and activity. It is found that the optimal Ni/TUD‐1‐GEL catalyst prepared by a gel‐assisted one‐pot synthesis method possesses a smaller particle size. Additionally, its moderate MSI restrains the migration and coalescence of active species. This ultimately results in a superior performance with CO 2 conversion of 65.4% without evident deactivation for 156 h on stream at an ultra‐low temperature of 225°C, which is one of the best performances of catalysts in published works under the given conditions. In situ diffuse reflectance infrared Fourier transforms reveal that CO 2 is sequentially converted into formate and carbonate and, finally, CH 4 . Moreover, the formation and evolution of the active phase during catalyst synthesis and reaction processes are probed by in situ x‐ray diffraction.
Journals
2026 EN
Yang Sheng · Zhang Hong · Li Wanxin
+1 more
Abstract As the primary proton‐conducting carrier in high‐temperature proton exchange membrane fuel cells (HT‐PEMFCs), the leaching process of phosphoric acid (PA) substantially accelerates performance decay and reduces the lifespan of PEMFCs. A three‐dimensional Lattice Boltzmann Method model is presented to simulate the PA leaching process in HT‐PEMFCs by coupling the catalytic layer structures generated by the improved quartet structure generation set method. The model demonstrates high efficiency, accuracy, and realism. Based on this model, the process of PA droplets invading the catalytic layer is described in detail, and the influence of factors such as porosity on fluid dynamics is analyzed. The results indicate that in the catalytic layers with different porosities, ε = 54% is associated with reduced droplet invasion and an acceptable pressure increase; smaller droplets, lower gas velocity conditions, thicker catalytic layers, and larger contact angles have been shown to be more conducive to mitigating the impact of PA invasion.
Journals
2026 EN
Luo Jie · Qu MingLiang · Yang JinPing
+4 more
Abstract Optimizing convective heat transfer in packed beds is critical for energy‐efficient process design, yet the interplay between particle configuration and pore‐scale transport remains poorly understood. We propose an experimentally validated dual network model (DNM) to explore a wide range of packing configurations and flow conditions to guide packing optimization. Using stratified beds for demonstration, we show that placing a small‐particle layer adjacent to the heating surface enhances heat transfer, with an optimal layer thickness (~7.1% of bed width representing a single‐layer), beyond which a rising pressure drop reduces overall efficiency. Cross‐flow analysis attributes these improvements to increased conduction, suppressed channeling, and intensified local mixing. Increasing particle size differences further boosts heat transfer but increases hydraulic resistance, shifting the optimal thickness toward smaller values. This experimental–modeling integrated framework provides pore‐scale insights into the trade‐off between heat transfer and pressure drop, offering practical guidelines for scalable thermal management and process intensification.
Journals
2026 EN
Gao Xin · Liu HanXuan · Xiao Donghui
+3 more
Abstract Partial hydrogenolysis of dimethyl oxalate (DMO) to methyl glycolate (MG) is a central step in biodegradable polyglycolic acid (PGA) production. However, it remains a great challenge for efficient and selective DMO hydrogenolysis under mild temperature (<100°C). In this work, we demonstrate an outstanding DMO hydrogenolysis by employing alkaline (Na, K) metal‐doped Ru catalysts. Na presents a stronger promotional effect than K. The highest yield of MG is achieved at 90.2% at 85°C in 15 h of reaction on 3Ru‐0.4Na/SiO 2 and the catalyst can be directly reused more than 10 times without any additional regeneration. The doping of Na effectively enables smaller Ru nanoparticle size, larger capacity of H 2 adsorption via a hydrogen pool (includes surface hydride, i.e., Na‐H δ − ) on Ru–Na interface, stronger strength of DMO adsorption. It is further revealed that there is a linear relation between the content of surface Ru 0 + Ru 3+ + Ru δ − and MG yield. Finally, an optimal ratio of Ru 3+ + Ru δ − /Ru 0 of 1.26 is achieved.