Electric unmanned aerial vehicles (E-UAVs) represent a promising vehicle platform with applications spanning medical services, agriculture, disaster relief, and geological surveys, among others. Within E-UAVs, power electronics play a pivotal role in transferring electrical energy from the battery to the electric motors as the driving force. However, the energy losses inherent in switching power semiconductor devices make these components major heat generators, necessitating the need for effective thermal management. Direct air cooling, due to its simplicity for weight-restricted platforms like E-UAVs, is a preferred method for managing these thermal challenges. In this study, we present a numerical analysis of a direct air-cooling system designed for a MOSFET-based motor control system embedded within an E-UAV's airfoil with 82 W loss per module. Through our parametric numerical studies, we design a low drag force heat sink by heuristically optimizing the fin shape, configuration, and height of a commercial benchmark under various E-UAV operating conditions, including altitude climbing and full-speed flight. Results indicate an optimal and machinable heat sink design featuring a configuration of elliptical pin fins with a functionally graded fin density that is exposed to external air flow. A further primary goal in the heat sink design is to achieve low thermal resistance at low flight speeds while also minimizing drag at higher speeds; these are objectives that are traditionally at odds with each other. Thus, to overcome this, we introduce innovative strategies such as a prepositioned, moveable front panel, and it is found that the optimal inclined angle of the front panel is similar to 15 degrees. While computational insights offer promising leads, experimental validation via wind tunnel tests is left as future work. In summary, the study provides guidance on power electronics thermal management for future E-UAV platforms.

Neurodegenerative diseases pose significant challenges to global healthcare, exacerbated by complexities of the central nervous system and blood–brain barrier. While FDA-approved magnetic nanocarriers offer promising solutions for targeted drug delivery, inherent challenges in predicting delivery performance still hinder clinical practice. Existing brain vasculature transport models often lack accuracy in the 3D construction of the brain vasculature network and physiology of blood circulation, limiting progress in targeted drug delivery. This paper introduced the Circle of Willis’s novel computational fluid dynamics framework to address these challenges. Utilizing patient-specific vascular geometries and incorporating complexities of blood circulation, hemodynamics, and the rheology for non-Newtonian fluid effect, our approach provides unprecedented insights into drug carrier dynamics in the mouse brain vasculature. Furthermore, we performed a comparative study simulating the dynamic transport using three types of magnetic nanocarriers—gold-coated superparamagnetic iron oxide (Au-SPIO), hollow-gold nano-shell enclosed superparamagnetic iron oxide (HGNS-SPIO), and metal–organic frameworks loaded with iron oxide (MOF-Fe3O4)—to predict their transport in adult mice’s brain under magnetic targeting. The simulation was validated by in vivo results by comparing the bioavailability of nanoparticles in different brain regions. Under a non-magnetic field, simulations revealed a capture efficiency of around 10.5

Magneto-plasmonic nanoparticles (MPNPs), such as solid gold (Au) or hollow gold (HG) coated superparamagnetic iron oxide (SPIO) nanoparticles (NPs), have attracted increasing attention for brain-targeted therapeutics. This is due to their supreme magnetic targeting capability, light-to-heat conversion efficiency, and biocompatibility. Though promising, their therapeutic efficiency is difficult to predict because of the complex absorption, distribution, metabolism, and excretion process and the intrinsic and extrinsic properties of the blood–brain barrier (BBB). This paper presents a modern physiologically based pharmacokinetic (PBPK) model to predict pharmacokinetic (PK) behaviors of brain-targeting MPNPs and investigate their morphology and surface function-dependent BBB crossing efficiency. This model quantifies intrinsic and extrinsic properties of PK parameters, including phagocytic cellular uptake rate and brain permeability. This model successfully predicts the biodistribution of functionalized Au-SPIO (18.42 ± 0.23 nm) and HG-SPIO (73.65 ± 1.46 nm) MPNPs in 8-week-old adult mice in a 16-h window after intraperitoneal (IP) injection. These predictions agree well with the experimental data with a low absolute average fold error (1.5381 for Au-SPIO and 1.1225 for HG-SPIO NPs). Interestingly, Au-SPIO MPNPs with thinner plasmonic layers result in higher magnetization levels and thus lead to more efficient BBB crossing. Static magnetic field stimulation could improve brain accumulation of IP-injected Au-SPIO and HG-SPIO NPs by up to 4.9

To enhance the efficiency of power electronics, a composite DC-DC converter architecture has been proposed based on the literature, which addresses the loss mechanisms associated with indirect power conversion explicitly over a wide range of operating conditions, especially at moderate-to-low workload. While the composite DC-DC converter possesses lower power losses and high reliability, it also has numerous components that generate heat and require thermal management, including power modules and planar magnetic components. The magnetic components include planar inductors and a planar transformer. To achieve a compact, power-dense overall composite boost converter structure, a double-side manifold micro-channel cold plate was developed. The physical architecture of the composite converter was optimized to strategically position the power modules and planar inductors on opposite sides of the thin form-factor cold plate. A volumetric power density of 21.3 kW/L, with a system volume of 5.9 L and maximum power of 126 kW was achieved. Packaging, design, and fabrication details of the system and unique multi-component cold plate are provided. Cold plate heat transfer coefficients, in the range of 10–22 kW/m2-K, with a pressure drop of ~9 kPa at a coolant flow rate of 10 L/min, were achieved to satisfy a range of component cooling requirements.

Higher levels of integration for improved functionality along with increased power density are important for electronics in future vehicle platforms, where greater efficiency and reduced volume are critical. Power switching devices (e.g., IGBT, MOSFET), driver boards, and cooling devices are three important components of a power electronic system. The design and integration of these three components strongly impact the efficiency, power density, and reliability of the power electronics. In the current work, a few highly integrated power electronic solutions with extremely high-power density were proposed. Detailed comparisons of the concepts in terms of cooling performance, thermal stress at the assembling interface, cost, reliability, feasibility, etc. were conducted and summarized. It was found that the concept of ceramic-polymer blend based bonding between the PCB and cold plate provided excellent cooling performance and the lowest thermal stress at the bonding interface, which makes it one of the most promising solutions.

A synergistic, adaptive, continuous-flow, and low-carbon solar evaporation and electrochemical treatment (SEET) system was proposed and researched for energy-efficient and sustainable decentralized water treatment. The hybrid system integrated anodic oxidation with solar evaporation to enhance organic degradation and optimize mass transport through the photo-thermal effect. A novel four-step numerical simulation method was proposed to design the system and examine the water evaporation process and mass transport of salts and organics. A case study was implemented, revealing that system parameters related to evaporation and organics degradation exhibited strong interdependence. The relationships between these parameters were well established, and adaptive water flow rate ranges were also identified to prevent salt accumulation while ensuring efficient organic degradation. The adaptability demonstrated the system's potential for use in varying influent scenarios. A prototype of the system was constructed, and the experimental data matched well with the simulation results. In the experiments, the local water temperature reached 45-50 degrees C in the continuous-flow mode under one sun condition, resulting in a 2-5 times reduction in outlet organic concentrations compared to traditional electrochemical systems. Energy analysis confirmed that the system primarily relied on clean and sustainable solar energy, maintaining a low carbon footprint. In conclusion, this innovative approach offers significant potential for addressing the clean drinking water crisis and enhancing pollutant removal in future decentralized water treatment systems.

The main translational barrier of neuroprotective drugs such as retinoic acid (RA) is the lack of targeted delivery to the specified brain region and the short half-life. Superparamagnetic iron-oxide (SPIO) coated with solid gold (SPIO@Au) and hollow gold (SPIO@HG) nanoparticles (NPs) have shown promise as brain-specific nanocarriers for sustainable and controlled delivery of neuroprotective drugs. However, their effectiveness has been restricted by their limited loading capacity. Surface functionalization with porous coordinate cages (PCCs) as a premium drug encapsulating component through SH-PEG-Py ligands has the potential to address this issue. Still, the traditional direct exchange (DE) method often results in insufficient functionalized ligands. This paper presents the anion exchange resin (AER)-based surface modification approach that can improve the number of functionalized ligands, regulate NP surface charges, and improve the colloidal stability by facilitating the ligand exchange reactions. This, in turn, has largely enhanced the drug encapsulation capacities of SPIO@Au NPs functionalized with PCCs. The hydrodynamic diameter and ζ-potential have validated the effectiveness of AER-based functionalization of PCCs on both SPIO@Au and SPIO@HG NPs. The colloidal stability of SPIO@Au-PCC NPs exhibits a more positive surface charge (38 mV) than the DE method (−17 mV). The loading capacity of RA with SPIO@Au-PCC has increased by 2.5 times compared with the traditional DE method (32.29 vs. 13.51 μg/mg). The 24-h release of RA has increased to 88

Cotton fabric has a wide application in the textile and furniture industries. However, because of its chemical composition and physical structure, it is highly flammable, which seriously threatens life and property. Incorporating insulating inorganic coatings onto cotton fabrics to mimic the formation of char layer, is a relatively new and effective strategy to improve their flame retardancy. In this study, as an affordable, environmentally friendly, and energy-efficient approach, biomineralization was applied to produce TiO2 coatings on the surface of cotton fabric to form a flame retardant system. The surface morphology and chemical compositions were well characterized first, and the flammability of treated cotton fabric was comprehensively evaluated using different techniques from micro to macro-scale. TiO2 coated cotton shows better flame resistance at the molecular level. The TiO2 coating produced by biomineralization exhibits a strong effect to reduce the burning intensity of cotton. The peak heat release rate is reduced by 5.5%, 27.1%, and 32.6%, respectively for TiO2 coated cotton with 1 cycle, 3 cycles, and 7 cycles of treatment. It also shows the potential to slow down the fire spread rate and the propensity of fire development. The protective effectiveness depends on the number of cycles of treatment. With only 1 cycle of treatment, it is not enough to attain a uniform TiO2 protective coating and thus it shows limited flame retardant performance. Once a uniform TiO2 coating is formed by biomineralization, it shows strong flame retardancy. With 7-cycle treatment, its limiting oxygen index can even reach 21.0%.

Interfacial solar evaporation holds great potential for water desalination; other sustainable energy resources naturally coexisting with solar energy (e.g., wind and water wave), however, have rarely been exploited to augment solar evaporation, especially in closed conditions. Herein, we developed a novel system that had an interfacial solar evaporator integrated with an angularly vibrating cantilever beam, harnessing both solar and water wave energies when floating on water surfaces for efficient water desalination. Super high evaporation rates of similar to 3.1 and 1.9 kg m(-2) h(-1) under simulated sunlight and vibrations were obtained in open and closed conditions, respectively. In outdoor tests floating on lake water surfaces, the cantilever beam effectively responded to realistic water waves of varying low frequencies and amplitudes, and the system delivered a high condensate collection rate of similar to 1.8 kg m(-2)h(-1). Mechanism studies revealed that the vibrating cantilever beam promoted vapor flow and condensation on selective surfaces. The cantilever beam enabled the direct mechanical energy transfer from water waves to moisture flow without using any electronics, resulting in great systemoperation-maintenance simplicity. This work provides new insights on advancing solar desalination with the simultaneous and rational utilization of multiple sustainable energy resources.

Solar steam generation is an emerging technology of desalination using renewable solar energy, but when treating saline water containing organics, the solar absorber is subject to fouling by low-surface-tension organics. Also, volatile organic compounds (VOCs) present in the source water may evaporate concurrently with water vapor and penetrate into the condensate, causing health concerns to the quality of the distilled water. In this work, we developed a unique water desalination process by integrating solar steam generation with electrochemical degradation to treat saline water containing organics, and strong synergistic effects have been experimentally demonstrated. The process used a dual-functional solar absorber that simultaneously served as a cathode of the electrochemical reactor, whose structural design was optimized by numerical simulation to balance heat transfer and mass transport. Degradation of three model organic pollutants, bisphenol A, phenol (VOC), and humic acid (natural organic matter) was evaluated, and the degradation rate constants were doubled under simulated sunlight compared to that without illumination, likely due to the high local temperature in the electrochemical reactor induced by the photothermal effect and preserved by the rational thermal insulation design. Furthermore, the concentration of VOCs in the condensate was reduced by 20 folds when electrochemical degradation of feed water was applied. In addition, the electrochemical degradation effectively mitigated humic acid fouling on the solar absorber, improving the steam generation rate by 20% after 12 h treatment, compared to the conventional solar evaporation process. Finally, the integrated solar desalination system achieved a thermal efficiency of 92.6% under real sunlight testing.

Cathodic membranes were applied with Fe reagent to enhance the mass transport of electro-Fenton (EF) by means of forced permeation. However, the considerable amount of toxic Fe reagent left in electrolytes may cause secondary pollution. Also, the membranes without active EF catalysts exposed low removal efficiency due to insufficient surface catalytic activity. In this work, an advanced flow-through process without toxic Fe reagent was developed using modified stainless steel (SS) mesh with high catalytic activity. The surface of SS mesh was decorated by catalytically-active FexCo3-xO4 nanoparticles and functionalized carbon nanotubes (CNTs). The synergistic effect between Fe and Co elements enhanced the electro-Fenton efficiency, and the optimal n(Fe): n(Co) ratio was determined at 1:2 from the degradation rate of pollutants and H2O2. The addition of FeCo2O4/CNT enhanced the first-order reaction rate k to 2.60 times on bisphenol A (BPA) removal, and 2.16 times on sulfamethoxazole (SMX) removal, compared to an undecorated mesh. Consequently, 94% of BPA were eliminated after 60 min and 100% of SMX were eliminated after 120 min, respectively, under a low current density of 2.84 mA cm. The total concentration of leached Fe/Co ions into the electrolyte was only around 2.4 μmol L after the treatment.

In situ construction has emerged for fabricating superwetting PVDF membranes with uniform organic coatings and improved resistance to oil fouling, but it remains almost unexplored to apply this strategy to attain durable inorganic coatings and prepare superior antifouling PVDF membranes. Herein, we developed a novel in situ biomineralization method to fabricate superhydrophilic and underwater superoleophobic PVDF-TiO2 membranes with conformal TiO2 coatings on both the top and internal surfaces. An initial flux of 400 L m(-2) h(-1) (LMH) with a final flux of 200 LMH at 2.5 h under 0.1 bar, oil rejection higher than 99.7%, and highly stable cycling per-formance (5 cycles at 130 min each) were achieved on crossflow filtration of surfactant-stabilized oil-in-water emulsions. We used a new "flux map" to make a relatively fair comparison among the reported membranes, which suggested the superior performance of our PVDF-TiO2 membrane. The demonstrated exceptional per-formance was attributed to the low oil adhesion and great hydrophilicity enabled by the durable and super-wetting coatings composed of densely packed TiO2 nanoparticles on the entire membrane, as well as to the relatively smooth top surface with an appropriate surface pore size that alleviate the oils being trapped by the surface structures.

Anodic electrocoagulation processes can remove broad varieties of pollutants in industrial wastewater. However, some stubborn contaminants may still remain in effluents after the treatment and cause environmental issues. To further improve the efficiency of pollutant removal, we have coupled electrocatalysis with electrocoagulation and applied an atomic layer deposition (ALD) enabled TiO2 ultrathin overcoating at a nanometer scale on a stainless steel cathode. The electrocatalytic overcoating increased the elimination efficiency of organics and microorganisms, likely due to the electro-generation of adequate reactive oxygen species (ROS). The thickness of TiO2 nanofilm was controlled by the number of ALD cycles, and it was found that nanofilms processed with 50-100 cycles led to the maximum benefit of pollutant removal. By using the novel electrocoagulation-electrocatalysis cell to treat synthetic wastewater, a remarkable removal of 99.92% of E. Coli, 92.1% of suspended solids, 98.3% of heavy metal ions, and 88.8% of methylene blue was observed. This hybrid electrochemical treatment process may have the potential to treat wastewater at a larger scale. (C) 2020 Elsevier Ltd. All rights reserved.

There has been a growing interest in thermal management materials due to the prevailing energy challenges and unfulfilled needs for thermal insulation applications. We demonstrate the exceptional thermal management capabilities of a large-scale, hierarchal alignment of cellulose nanofibrils directly fabricated from wood, hereafter referred to as nanowood. Nanowood exhibits anisotropic thermal properties with an extremely low thermal conductivity of 0.03 W/m·K in the transverse direction (perpendicular to the nanofibrils) and approximately two times higher thermal conductivity of 0.06 W/m·K in the axial direction due to the hierarchically aligned nanofibrils within the highly porous backbone. The anisotropy of the thermal conductivity enables efficient thermal dissipation along the axial direction, thereby preventing local overheating on the illuminated side while yielding improved thermal insulation along the backside that cannot be obtained with isotropic thermal insulators. The nanowood also shows a low emissivity of <5% over the solar spectrum with the ability to effectively reflect solar thermal energy. Moreover, the nanowood is lightweight yet strong, owing to the effective bonding between the aligned cellulose nanofibrils with a high compressive strength of 13 MPa in the axial direction and 20 MPa in the transverse direction at 75% strain, which exceeds other thermal insulation materials, such as silica and polymer aerogels, Styrofoam, and wool. The excellent thermal management, abundance, biodegradability, high mechanical strength, low mass density, and manufacturing scalability of the nanowood make this material highly attractive for practical thermal insulation applications.

•Personal thermal management can be applied for building energy saving and improving occupant thermal comfort.•A thermoelectric unit is proposed for personal thermal management.•Relationship established between personal energy requirement and thermoelectric energy supply.•Weight minimization of the thermoelectric unit is achieved.