Search Results (1,285)

Thermal energy storage (TES) technologies are essential for renewable energy integration, industrial waste heat recovery, grid flexibility, and improved energy efficiency. Despite advances in sensible heat thermal energy storage (SHTES), latent heat thermal energy storage (LHTES), and thermochemical energy storage (TCES), practical deployment remains constrained by inadequate heat transfer rates, which limit charging and discharging processes, reduce storage utilization, and increase system size and cost. Conventional heat-transfer enhancement approaches, including fins, embedded heat exchangers, conductive additives, porous structures, and flow intensification techniques often introduce trade-offs related to manufacturability, complexity, durability, and energy consumption. Additive manufacturing (AM) has emerged as a promising approach for overcoming these limitations by enabling precise control of internal geometry, porosity, surface-area-to-volume ratio, and fluid pathways. Through the fabrication of architected structures, lattice networks, triply periodic minimal surface (TPMS) geometries, and multifunctional heat-transfer architectures, AM enables geometry-driven optimization of thermal performance that is difficult to achieve using conventional manufacturing methods. These capabilities support the development of compact TES systems with enhanced heat transfer, improved thermal uniformity, and increased energy utilization. This review examines additive manufacturing technologies relevant to TES applications, including powder bed fusion, directed energy deposition, material extrusion, vat photopolymerization, and binder jetting. The relationships among manufacturing processes, material selection, and thermal performance are discussed across SHTES, LHTES, and TCES systems. Particular emphasis is placed on AM-enabled heat-transfer enhancement strategies, phase change material (PCM)-integrated structures, architected thermal networks, embedded heat exchangers, and computational design methodologies such as topology optimization. Current challenges involving material compatibility, scalability, cost, and long-term durability are also evaluated. The review highlights how additive manufacturing is transforming TES design from a material-centered paradigm toward geometry-enabled thermal engineering, creating new opportunities for next-generation energy storage systems. Full article

With the growing demand for continuous health assessment and early disease screening, biofluids have attracted increasing attention because they provide molecular information that cannot be obtained from conventional physical signals alone. However, practical biofluid analysis remains constrained by limited sample volumes, unstable wet interfaces, complex fluid transport, and dependence on external power sources. Triboelectric nanogenerators and triboelectric nanosensors offer a promising solution by combining mechanical energy harvesting with direct signal transduction. This review provides a critical overview of the theoretical basis of triboelectric biofluid sensing, including working modes, figures of merit, charge-transfer mechanisms, and the differences between solid–solid and solid–liquid electrification. Material selection, interfacial functionalization, fluid collection, wearable configurations, and multimodal integration are further discussed. Recent applications involving sweat, tears, saliva, urine, interstitial fluid, blood, and wound exudate are summarized to clarify how triboelectric devices function as either power sources or active sensing interfaces. Particular attention is given to their potential in early screening, risk assessment, and auxiliary diagnosis. Current limitations associated with biofouling, charge dissipation, individual variability, biosafety, durability, calibration, and clinical validation are also evaluated. Finally, future directions are proposed to improve analytical reliability and accelerate the translation of self-powered biofluid sensors from laboratory prototypes to clinically meaningful healthcare platforms. Full article

Rice husk, an abundant agro-industrial by-product rich in SiO₂, represents a promising precursor for the sustainable synthesis of zeolites. In this study, rice husk ash was used to synthesize faujasite-type X and faujasite-type Y, and their performance for Hg²⁺ removal from aqueous solutions was comparatively evaluated. X-ray diffraction confirmed the successful formation of the faujasite structures, while physicochemical characterization revealed differences in pore structure and surface chemistry. FAU-type X exhibited higher Hg²⁺ removal than FAU-type Y, consistent with the combined influence of its lower Si/Al ratio, higher framework charge density and ion-exchange capacity, as well as its larger pore volume and average pore diameter. Based on its higher Hg²⁺ removal, FAU-type X was selected for a comprehensive evaluation of its adsorption performance and applicability under environmentally relevant conditions. The pseudo-second-order model best described adsorption kinetics for both zeolites, whereas thermodynamic analyses indicated that the adsorption process was spontaneous and endothermic. Optimal adsorption conditions for FAU-type X were achieved at pH 6.8, using an adsorbent dosage of 0.75 g L⁻¹, a contact time of 24 h, and an initial Hg²⁺ concentration of 1 mg L⁻¹. Equilibrium data were best fitted by the Sips isotherm model, indicating adsorption on a heterogeneous surface with a maximum adsorption capacity of 83.14 mg g⁻¹. FAU-type X retained appreciable adsorption performance after four regeneration cycles, although Hg²⁺ removal efficiency decreased in Caquetá River water because of competition from coexisting metal ions. To assess the environmental implications of the treated water beyond Hg²⁺ removal efficiency, ecotoxicological assays demonstrated the sensitivity of Daphnia magna to residual Hg²⁺ concentrations, whereas reductions in Escherichia coliforms were mainly attributed to the adsorption process. In addition, Lactuca sativa seedlings exhibited approximately 50% inhibition of elongation after treatment. Overall, these findings demonstrate the potential of rice husk-derived faujasite-type X as a sustainable adsorbent for Hg²⁺ removal, while highlighting the need for complementary treatment strategies to ensure the environmentally safe discharge of water and its agricultural reuse. Full article

The increasing deployment of decentralized renewable energy systems requires sustainable, affordable, and high-energy-density storage technologies. While thermal energy storage using phase change materials (PCMs) represents a promising solution, its widespread adoption remains limited by the low thermal conductivity of most PCMs, which restricts (dis)charge power. This work demonstrates that high discharge powers can be achieved through optimized heat-exchanger design without enhancing the intrinsic thermal conductivity of the PCM. After sizing simulations for individual homes, a thermal storage demonstrator integrating water heat exchangers immersed in two PCM reservoirs for domestic hot water and space heating was designed and experimentally investigated. The prototype achieved discharge powers exceeding 80 kW, sustaining 65 kW once transit water had fully cleared the tank, in a compact PCM heat exchanger volume of 0.79 m³, despite the low PCM thermal conductivity of only 0.16 W·m⁻¹K⁻¹. This performance is enabled by a heat-exchanger design providing 203 m² of heat-transfer area while limiting the maximum PCM-to-fin distance to about 1.5 mm. Thermosiphon-driven natural convection was also observed during melting and may further enhance heat transfer. These results demonstrate that heat-exchanger geometry, rather than enhanced PCM conductivity, is the key design parameter for achieving compact, high-power PCM thermal energy storage. Full article

Experimental measurements and two-dimensional axisymmetric fluid simulations are performed to study coaxial argon dielectric barrier discharge. Oscilloscope measurements capture voltage–charge waveforms and Lissajous figures to resolve cycle-integrated electrical characteristics. Continuous-integration optical emission spectroscopy without phase resolution is used to qualitatively verify metastable argon. As peak voltage rises from 5 kV to 13 kV, the simulated volume-averaged electron temperature displays a pronounced N-shaped trend: it peaks at 9 kV, falls abnormally between 10 kV and 11 kV, and recovers at higher voltages. This non-monotonic variation arises from intra-cycle self-shielding by dielectric surface charges together with power-broadening driven by discharge spatial expansion. Monotonically increasing equivalent capacitance confirms continuous surface charge accumulation, and the simulated inward shift of the high-electron-temperature region validates the emergence of surface-charge-induced reverse electric fields. The discharge maintains a steady filamentary regime across all tested conditions. Because microdischarge filaments occupy only a small portion of the gap, the volume-averaged electron density from simulations is far lower than the peak density within individual streamers. This work elucidates the mechanism underlying the anomalous electron temperature drop at moderate voltages and offers guidance for controlling atmospheric-pressure filamentary DBD. Full article

Resorcinol–formaldehyde (RF)-derived porous carbons have attracted considerable attention as anode materials for lithium-ion batteries because of their tunable pore structures and continuous carbon frameworks. However, conventional one-factor-at-a-time experiments do not readily allow the relative effects of multiple preparation factors to be systematically compared within a unified experimental framework. In this study, a mixed-level Design of Experiments (DOE) was employed to systematically investigate the effects of solid content, gelation temperature, R/C ratio, combined gelation and acid-washing/aging times, and drying method on the BET specific surface area, total pore volume, and dominant pore size of RF-derived porous carbons. Representative preparation conditions were subsequently selected to prepare PC-1 and PC-2. Both samples exhibited predominantly amorphous mesoporous carbon structures and similar electrochemical response profiles. PC-1 exhibited a higher reversible specific capacity and slightly more favorable electrochemical kinetics. These concurrent observations suggest an association between the pore-structure characteristics and electrochemical behavior of the selected samples. PC-1 delivered an initial charge capacity of 416.67 mAh g⁻¹ with an initial Coulombic efficiency of 79.31%. After 200 cycles at 0.1 A g⁻¹, it retained a reversible capacity of 307.86 mAh g⁻¹, corresponding to a capacity retention of 88.64% relative to the second-cycle charge capacity. These results indicate that, within the investigated design space, the DOE approach provides an exploratory basis for jointly comparing the statistical evidence and practical effect magnitudes of the preparation factors and for selecting representative candidates with favorable pore-structure characteristics. The integration of DOE-based factor screening with subsequent structural and electrochemical validation provides an experimentally grounded framework for relating preparation parameters to pore-structure responses and lithium-storage behavior, thereby supporting the rational development of RF-derived porous carbon anodes for lithium-ion batteries. Full article

Electrospinning is a versatile technique for producing membranes composed of submicrometric fibers and possessing high porosity and a large surface-to-volume ratio. These properties make electrospun fiber mats attractive for many applications including filtration, biomedical materials, and sensing. While conventional set-ups readily generate randomly oriented nonwovens, many applications require precise control over fiber organization. Such control can be achieved by manipulating the charged jet and the residual charges retained by deposited fibers, both governed by the electric field that is intrinsic to the electrospinning process. This review examines strategies for electrostatic control of electrospun fiber mat morphology, organized around two principal mechanisms: control of the charged jet in-flight and control of the landing jet. Auxiliary electrode-assisted electrospinning, which aims to suppress or redirect the whipping instabilities, as well as gap-separated and structured collectors that exploit electrostatic template effects, are discussed. Particular attention is given to the underlying mechanisms. Collectively, these methods illustrate how tailoring the electric field allows for the production of membranes with complex, application-specific fiber morphologies. Full article

The present study proposes a configuration of a solar PV-battery-powered knapsack sprayer (SPKS) equipped with a rear-mounted multi-nozzle boom to serve as a sustainable, reliable and decentralized spraying system for smallholder farmers. This design aims to significantly reduce the physiological strain and inconsistent performance associated with conventional manual lever sprayers (MLSs). The SPKS was evaluated against the MLS during onion crop spraying in terms of hydraulic performance, field capacity, spray deposit uniformity, and operator ergonomics and biomechanics, alongside an economic and environmental sustainability assessment. Results of hydraulic tests revealed that the SPKS achieved the optimal spray distribution uniformity of C.V = 16.67% at an operating pressure of 350 kPa and a boom height of 40 cm. Field experiments demonstrated that the SPKS more than doubled the effective field capacity to 0.36 ha/h compared to 0.16 ha/h for the MLS, achieving a field efficiency of 67.55%. Moreover, the SPKS achieved high spray deposit coverage (88%) compared to the MLS (52.6%), while the integrated PV panel effectively doubled operational runtime by maintaining >50% battery state of charge under continuous load. Biomechanics and ergonomics pilot analyses indicated that the MLS operation imposed high musculoskeletal (RULA score = 7) and cardiac strain, whereas SPKS operation was classified as low-risk (RULA score = 3) with minimal cardiac strain. Economically, the SPKS saves approximately $8.70 USD per hectare in labor costs. Environmentally, it prevents ~17.0 kg of CO₂ emissions annually and reduces pesticide application volume by 26.5%. By simultaneously addressing energy limitations, ergonomic hazards, and operational inefficiencies, the SPKS offers a holistic and superior solution for sustainable smallholder agriculture. Full article

Organic electrochemical transistors (OECTs) utilize ion injections to regulate the overall conductivity of the organic semiconductor channel, achieving high transconductance (g_m) by coupling ionic and electronic charge carriers within the whole channel’s volume. However, the slow ion migration rate through the hydrophobic semiconducting polymer layer restricts the response rate of the device for widespread applications in biomedical sensing. This work introduced poly(ethylene glycol) (PEG) bisazide photo-crosslinking agent into the p-type semiconducting polymers as a hydrophilic active channel in accumulated-mode OECTs. Upon incorporation of PEG segments into conjugated polymers via photolithography, the resulting OECTs exhibit a significant enhancement in both µC* product and doping/de-doping dynamics by at least one order of magnitude. The photo-patterning of an ion-conducting semiconductor channel with a minimum line gap of 5 µm enables the fabrication of a depletion-mode inverter. This study presents a straightforward patterning process that enhances the hydrophilicity of various hydrophobic conjugated polymers while eliminating the need for complex synthesis procedures typically required for introducing ethylene glycol side chains on conjugated polymers. Full article

The rapid growth of electric-vehicle charging demand has increased the need for reliable station-level congestion monitoring and early warning. Existing studies mainly predict charging demand, load, occupancy, or availability, whereas charging congestion pressure is usually shaped by multiple operational factors. This study proposes an interpretable station-level charging congestion pressure assessment and multi-horizon early-warning framework. A Charging Congestion Pressure Index (CCPI) is constructed by integrating occupancy, arrival pressure, charging or occupation duration, service volume, and price–time context into a unified station–hour pressure representation. Based on temporally aligned current, lagged, and rolling features, future high-pressure states are predicted at 1 h, 3 h, and 6 h horizons. Using 1423 charging stations and 6,181,512 station–hour observations from September 2022 to February 2023, this study evaluates whether the proposed station–hour pressure representation can support multi-horizon high-pressure warning under temporal and station-level validation settings. Results show that current pressure is a strong short-term persistence baseline, while learning-based models provide larger F1-score gains at longer horizons. Extreme Gradient Boosting (XGBoost) achieved F1 gains of +0.022, +0.040, and +0.068 over the persistence baseline at the 1 h, 3 h, and 6 h horizons, respectively. Ablation, temporal validation, station holdout validation, and block-bootstrap tests further support the stability of the proposed framework. These findings indicate that interpretable pressure-index construction and temporally consistent multi-horizon warning can provide an engineering decision-support basis for charging-infrastructure operation, station-level congestion monitoring, and proactive resource management. Full article

Water scarcity in semi-arid regions makes efficient irrigation scheduling a priority, yet farm-level adoption of soil-moisture monitoring remains limited by the cost, low portability and installation complexity of commercial sensing systems. This study presents the development and field validation of WaziSense, a low-cost, solar-powered Internet-of-Things (IoT) smart tensiometer, developed within the OSIRRIS platform for soil-water monitoring and irrigation scheduling. The device couples a Watermark granular-matrix sensor and a DS18B20 temperature probe to an ATmega328P microcontroller (Arduino Pro-Mini, 3.3 V, 8 MHz) with long-range LoRa communication and a maximum-power-point-tracking (MPPT) solar-charging stage, logging soil matric potential and soil temperature every 15 min. An open-source edge/cloud stack (WaziGate, WaziApp) retrieves weather forecasts from an open API and runs an automated machine learning (AutoML) regression pipeline that forecasts soil-water dynamics and the time to a user-defined threshold, from which irrigation is scheduled and its applied volume verified by a flow meter. The system was deployed at three bioclimatic sites in Tunisia (durum wheat at Cherfech, citrus at Nabeul, apple at Sbeitla), with tensiometers installed at 20 and 40 cm depths, and validated against commercial 10HS capacitive probes coupled to a ZL6 data logger, with which the co-located readings were significantly correlated (r = 0.81). Calibrated readings showed a strong relationship between soil–water content and soil–water potential (R² = 0.99), and the edge forecasting model reproduced soil–water dynamics on unseen data (Sbeitla apple site, 5-day horizon) with R² = 0.73, RMSE = 0.35, MAE = 0.23 and MPE = 12.52%. With a material cost under about 90 EUR per node and fully open-source hardware and software, WaziSense is one to two orders of magnitude cheaper than commercial monitoring stations, offering an affordable, reproducible and scalable tool for data-driven irrigation in water-limited agriculture. Full article

It is essential to design electrode structures which simultaneously ensure mechanical strength and facilitate rapid sodium-ion transport to enable practical and large-scale sodium-ion battery (SIB) applications. In this study, we report a novel anode material featuring a cross-linked architecture composed of MoS₂ reinforced internally by catalytically derived CoS₂@C-supported carbon nanotubes (CNTs), and externally by commercial multi-walled carbon nanotubes (MWCNTs). This dual-reinforced configuration effectively prevents MoS₂ layer aggregation, enhances structural integrity, and establishes continuous conductive frameworks for efficient electron transmission. Additionally, it offers ample ion-diffusion pathways and mechanical resilience to buffer volume changes during cycling. Density functional theory (DFT) simulations reveal that the modified MoS₂ structure exhibits a significantly reduced sodium-ion diffusion barrier, contributing to enhanced charge-discharge kinetics. The CoS₂@C/CNTs@MoS₂@MWCNTs electrode achieves remarkable cycling stability, retaining 395 mA h g⁻¹ at 1 A g⁻¹ for 2000 cycles. In situ X-ray diffraction (XRD) along with kinetic analyses confirm a pseudocapacitance-dominated storage mechanism. Furthermore, full coin-type cells assembled with Na₃V₂(PO₄)₃ cathodes demonstrate excellent cycling performance, demonstrating the practical potential of this design strategy for advanced SIBs. Full article

Upgrading biogas to pipeline-quality methane requires the efficient removal of CO₂, yet conventional physicochemical routes remain energy-intensive. Coupling a CO₂-selective membrane with microalgal photosynthetic fixation offers a green alternative, but is constrained by the low CO₂/CH₄ selectivity of common membranes and the poor adhesion of microalgae to hydrophobic membrane surfaces. Here, a dual-functional composite membrane was developed that simultaneously provides CO₂/CH₄ sieving and a biocompatible interface for microalgal attachment, and was integrated into a microalgae membrane bioreactor (MMBR). A cellulose acetate mixed-matrix membrane incorporating polyethyleneimine-grafted ZIF-8 (CA/PZIF-8(15)) achieved a mixed-gas CO₂ permeability of 122.3 Barrer and a CO₂/CH₄ selectivity of 41.17. An ionic-liquid-modified chitosan (CS/IL) coating, first optimized on a commercial flat-sheet polyethersulfone (PES) membrane used as a model surface for the adhesion study, reversed the surface charge from −30.8 to +3.75 mV, lowered the water contact angle to 51.2°, and increased the day-7 adhesion of Scenedesmus obliquus by ~108%. Transferring the coating onto CA/PZIF-8(15) further raised the permeability to 138 Barrer and the selectivity to 57.31, placing the composite above the 2008 Robeson upper bound. In the MMBR, CH₄ purity reached 95.13% after 48 h; a mass balance on the recirculating gas volume indicated that essentially all of the CO₂ removed from the gas phase permeated the membrane, of which an estimated 2% was fixed into microalgal biomass while the remainder was retained in the liquid phase. This work offers a membrane-design strategy that bridges gas-separation functionality and microalgal carbon fixation for sustainable biogas upgrading. Full article

Maritime routes ensure connectivity between nations, carrying a vast flow of goods across borders, while ports serve as the critical junctions within this network, managing a wide spectrum of commodities from raw materials to finished goods. Ports also generate employment across numerous sectors and underpin a broad range of allied industries. A seaport is a maritime facility equipped with docks, cranes, and storage infrastructure for international trade, where ships load and unload cargo, containers, and passengers. Key functions of seaports include customs processing, warehousing, and vessel services, with major global hubs such as Shanghai, PSA Singapore, DP World, and Rotterdam handling immense volumes of cargo each year. In contrast, Bangladesh’s ports, Chittagong, Mongla, and Payra, play a vital role in sustaining regional commerce. Today, ports are widely recognized as essential capital infrastructure and prime movers of economic activity. Smart ports are automated facilities that leverage advanced digital technologies, including sensors, big data analytics, artificial intelligence (AI), machine learning (ML), deep learning (DL), augmented reality (AR), digital twins, the Internet of Things (IoT), and various automation systems, to optimize overall operational efficiency. These tools streamline cargo movement while embedding sustainable practices to protect the environment. Beyond operational gains, smart ports deliver faster, more advanced services to all stakeholders involved in port operations, including shipping companies, customs agencies, local communities, and other relevant parties. Renewable energy sources, electric vehicle charging stations, onshore power supply, and smart logistics infrastructure are among the defining sustainability features of smart ports in the present-day context. This study examines the current status and future development trajectory of Bangladesh’s sea ports in relation to the broader global imperative toward smart port transformation. Full article

Large volumes of solid waste are produced by the winemaking sector, which could be utilised as adsorbents to retain contaminants, providing a beneficial approach in terms of economic recovery and sustainability. The adsorption of nitrate onto biochar produced from grape pomace has not received enough attention, even though biochar-based materials have been thoroughly studied for water treatment applications. This study aims to fill the knowledge gap by assessing a low-cost mildly carbonized biochar derived from winery residues for nitrate retention and optimising the nitrate retention procedures by comprehensive physicochemical characterisation. The mildly carbonized biochar prepared from grape pomace collected from the Dealu Mare wine region (Romania) was characterized using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM–EDX), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), and thermogravimetric and derivative thermogravimetric (TGA/DTG) analyses. Results revealed a structure enriched with oxygen-containing functional groups that promote nitrate retention through combined physical adsorption and electrostatic interactions. Surface analyses after adsorption confirmed the successful immobilization of nitrate species on the biochar matrix. The adsorption performance was improved by Response Surface Methodology (RSM) method using a Central Composite Design (CCD), studying the influences of the following parameters: solution pH, adsorbent weight, nitrate concentration and time. Among all variables, pH was identified as the dominant factor controlling adsorption efficiency, reflecting the key role of surface charge interactions. The optimized conditions (175 mg/L nitrate, pH 6, 0.3 g adsorbent dosage, and 94 min contact time) resulted in a maximum nitrate removal efficiency (RE) of 86.69%, while the predictive model exhibited excellent accuracy (R²_adj = 0.985). The findings demonstrate that mildly carbonized grape pomace biochar can achieve competitive nitrate removal without chemical surface modification, offering a more sustainable and economically attractive alternative to conventionally biochars. The research highlights that selecting feedstock and utilizing intrinsic surface functionality can create efficient nitrate adsorbents from agro-industrial residues. Full article