Low Evaporation Rate Research Articles

Novel PVA-Hyaluronan-Siloxane Hybrid Nanofiber Mats for Bone Tissue Engineering.

Hyaluronan (HA) is a natural biodegradable biopolymer; its biological functions include cell adhesion, cell proliferation, and differentiation as well as decreasing inflammation, angiogenesis, and regeneration of damaged tissue. This makes it a suitable candidate for fabricating nanomaterials with potential use in tissue engineering. However, HA nanofiber production is restricted due to the high viscosity, low evaporation rate, and high surface tension of HA solutions. Here, hybrids in the form of continuous and randomly aligned polyvinyl alcohol (PVA)-(HA)-siloxane nanofibers were obtained using an electrospinning process. PVA-HA fibers were crosslinked by a 3D siloxane organic-inorganic matrix via sol-gel that restricts natural hydrophilicity and stiffens the structure. The hybrid nanofiber mats were characterized by FT-IR, micro-Raman spectroscopy, SEM, and biological properties. The PVA/HA ratio influenced the morphology of the hybrid nanofibers. Nanofibers with high PVA content (10PVA-8 and 10PVA-10) form mats with few beaded nanofibers, while those with high HA content (5PVA-8 and 5PVA-10) exhibit mats with mound patterns formed by "ribbon-like" nanofibers. The hybrid nanofibers were used as mats to support osteoblast growth, and they showed outstanding biological properties supporting cell adhesion, cell proliferation, and cell differentiation. Importantly, the 5PVA-8 mats show 3D spherical osteoblast morphology; this suggests the formation of tissue growth. These novel HA-based nanomaterials represent a relevant advance in designing nanofibers with unique properties for potential tissue regeneration.

A High-resolution Non-detection of Escaping Helium in the Ultrahot Neptune LTT 9779b: Evidence for Weakened Evaporation

The recent discovery of “ultrahot” (P < 1 day) Neptunes has come as a surprise: some of these planets have managed to retain gaseous envelopes despite being close enough to their host stars to trigger strong photoevaporation and/or Roche lobe overflow. Here, we investigate atmospheric escape in LTT 9779b, an ultrahot Neptune with a volatile-rich envelope. We observed two transits of this planet using the newly commissioned WINERED spectrograph (R ∼ 68,000) on the 6.5 m Clay/Magellan II Telescope, aiming to detect an extended upper atmosphere in the He 10830 Å triplet. We found no detectable planetary absorption: in a 0.75 Å passband centered on the triplet, we set a 2σ upper limit of 0.12% (δ R p /H < 14) and a 3σ upper limit of 0.20% (δ R p /H < 22). Using a H/He isothermal Parker wind model, we found corresponding 95% and 99.7% upper limits on the planetary mass-loss rate of Ṁ<1010.03 g s−1 and Ṁ<1011.11 g s−1, respectively, smaller than predicted by outflow models even considering the weak stellar X-ray and ultraviolet emission. The low evaporation rate is plausibly explained by a metal-rich envelope, which would decrease the atmospheric scale height and increase the cooling rate of the outflow. This hypothesis is imminently testable: if metals commonly weaken planetary outflows, then we expect that JWST will find high atmospheric metallicities for small planets that have evaded detection in He 10830 Å.

Investigation of Evaporation Rate for Covered and Uncovered (using recycled materials) Conditions in UiTM Shah Alam

The evaporation rate varies according to temperature, humidity, and wind. The evaporation rate tends to be higher in the hot, dry months and lower in the wetter ones. This may affect the nation’s energy use, indoor air quality, and water availability. This study conducted experiments under three conditions—uncovered, partially, and fully covered to ascertain the evaporation rate at UiTM Shah Alam, Malaysia. Recycled materials such as bottle caps were used in the experiment. The study examined the evaporation rate at UiTM Shah Alam in Selangor. The study discovered that the uncovered surface area evaporated at the highest rates in the morning, noon, and afternoon due to direct solar exposure. As some or all of the surface was shielded from the sun’s rays, partially covered and fully covered surface areas had lower evaporation rates. It shows the evaporation rate for fully covered condition reduced 22 – 50 percent from uncovered condition. Meanwhile, evaporation rate for partially covered condition decreased by 10 – 17 percent compared to uncovered condition. The study offers important information about the variables influencing evaporation rate, which can be used to enhance understanding of evaporation processes and optimize evaporation in various applications. The findings may shed important light on the evaporation process and the variables that influence it, such as temperature, humidity, and cover material. The research results can be used to enhance building design and construction methods, increase building energy efficiency, and guide water management and conservation policies.

Dominance of net autotrophy in arid landscape low relief polar lakes, Nunavut, Canada.

The Arctic is the fastest warming biome on the planet, and environmental changes are having striking effects on freshwater ecosystems that may impact the regional carbon cycle. The metabolic state of Arctic lakes is often considered net heterotrophic, due to an assumed supply of allochthonous organic matter that supports ecosystem respiration and carbon mineralization in excess of rates of primary production. However, lake metabolic patterns vary according to regional climatic characteristics, hydrological connectivity, organic matter sources and intrinsic lake properties, and the metabolism of most Arctic lakes is unknown. We sampled 35 waterbodies along a connectivity gradient from headwater to downstream lakes, on southern Victoria Island, Nunavut, in an area characterized by low precipitation, organic-poor soils, and high evaporation rates. We evaluated whether lakes were net autotrophic or heterotrophic during the open water period using an oxygen isotopic mass balance approach. Most of the waterbodies were autotrophic and sites of net organic matter production or close to metabolic equilibrium. Autotrophy was associated with higher benthic primary production, as compared to its pelagic counterpart, due to the high irradiance reaching the bottom and efficient internal carbon and nutrient cycling. Highly connected midstream and downstream lakes showed efficient organic matter cycling, as evidenced by the strong coupling between gross primary production (GPP) and ecosystem respiration, while decoupling was observed in some headwater lakes with significantly higher GPP. The shallow nature of lakes in the flat, arid region of southern Victoria Island supports net autotrophy in most lakes during the open water season. Ongoing climate changes that lengthen the ice-free irradiance period and increase rates of nutrient evapoconcentration may further promote net autotrophy, with uncertain long-term effects for lake functioning.

Biomimetic Structural Design of Fabric for Low‐Cost, Scalable, and Highly Efficient Off‐Grid Solar‐Driven Water Purification

AbstractInterfacial solar‐vapor generation (ISVG) is an emerging technology for water purification. However, high cost, low evaporation rate, clogging issues, and limited solar utilization under natural condictions greatly hinder its practical application. Herein, inspired by the aligned microstructure of dragonfly wings, a 3D microarray structure composed of vertically aligned hierarchical and hydrophilic carbon fibers (CFs) is constructed using a scalable fiber manufacturing technology. The microarray structure of the high‐thermal‐conductivity CFs with nanocapillaries contributes to the fast mass (steam and salt ions) and heat transfer as well as high omnidirectional light absorption. More importantly, due to the strong multiscale capillary effect, the formed 3D water evaporation surface containing abundant micro‐meniscuses and nanoscale thin water layers in the CFs arrays effectively reduces the evaporation enthalpy and creates more water/air interfaces, leading to the significant increasing evaporation rate. As a result, a high evaporation rate of 2.21 kg m−2 h−1 under one‐sun irradiation can be achieved. Moreover, the off‐grid water treatment device assembled with multiple 3D CFs‐based customized spherical evaporators can obtain a high pure water collection of 10.71 kg m−2 per day without salt accumulation under real environmental conditions. This work demonstrates a high‐efficiency, cost‐effective, and scalable strategy for high‐performance ISVG.

Salt-rejecting 3D cone flowing evaporator based on bilayer photothermal paper for high-performance solar seawater desalination

Solar energy-driven water evaporation technology is a promising, low-cost and sustainable approach to alleviate the global clean water shortage, but usually suffers from low water evaporation rate and severe salt deposition on the water evaporation surface. In this work, a hydrophilic bilayer photothermal paper-based three-dimensional (3D) cone flowing evaporator was designed and prepared for stable high-performance seawater desalination with excellent salt-rejecting ability. The as-prepared bilayer photothermal paper consisted of MXene (Ti3C2Tx) and HAA (ultralong hydroxyapatite nanowires, poly(acrylic acid), and poly(acrylic acid-2-hydroxyethyl ester)). The accordion-like multilayered MXene acted as the efficient solar light absorber, and ultralong hydroxyapatite (HAP) nanowires served as the thermally insulating and supporting skeleton with a porous networked structure. A siphon effect-driven unidirectional fluid transportation unit in the 3D cone flowing evaporator could guide the concentrated saline flowing away from the evaporating surface to prevent salt deposition on the evaporation surface, avoiding severe deterioration of the performance in solar water evaporation. Furthermore, combining high solar light absorption and high photothermal conversion efficiencies, low water evaporation enthalpy (1838 ± 11 J g−1), and additional energy taken from the ambient environment, the as-prepared cone flowing evaporator exhibited a high water evaporation rate of 3.22 ± 0.20 kg m−2 h−1 for real seawater under one sun illumination (1 kW m−2), which was significantly higher than many values reported in the literature. This study provides an effective approach for designing high-performance solar energy-driven water evaporators for sustainable seawater desalination and wastewater purification.

Electrical and thermal characteristics of LaB6 thermionic hollow cathodes operating in He, D2, Ar, and Xe at 4–200 Pa and 0.25–5 A cm−2

We report characteristics of lanthanum hexaboride (LaB6) cathodes for conditions relevant to a high-voltage, high-current switching device. LaB6 is selected because of its relatively low work function, stability in the presence of many common gas impurities, and a low evaporation rate (long life) at operating temperatures. We have investigated the effect of cathode geometry, gas type, pressure, and current on a LaB6 hollow cathode in a diode configuration with an opposing planar anode. The gas is stagnant at a relatively low pressure of 4–200 Pa (0.03–1.5 Torr) because of device high-voltage standoff requirements. In all cases, the plasma voltage decreases to a plateau value with increasing current where a practical device would operate. The plateau voltage aligns with the fill gas excitation or ionization voltage, depending on conditions. At high current, the cathode temperature exceeds that required for thermionic emission to supply the total current, a behavior that is understood by accounting for back-diffusing bulk electrons.

Real-time control of distillation process to improve the recovery efficiency of ThF4-LiCl-KCl molten salt.

The purification and recovery of chloride electrolyte molten salts are vital to reuse this valuable species and reduce the waste. Vacuum distillation method was used to investigate the recovery efficiency of LiCl-KCl mixed molten salt containing 20 wt% ThF4. Rapid mass loss in the initial stage and the subsequent lower evaporation rate were significantly observed under 1173 K and 20 Pa due to the coordination species such as Li3ThF7 and LiTh2F9. To achieve the recovery efficiency of chloride salts, a real-time control distillation was proposed. The distillation was terminated when about 80% mixture salt was evaporated according to the transient weight loss curve. The evaporation ratio of LiCl-KCl reached 91% and the decontamination factors for Th and rare earth elements Nd and Sm were more than 103 and 102, respectively. The results provided a simple and effective scheme to separate ThF4 and recover molten salts from waste electrolyte salts.

Thermal performance of cylindrical and spherical liquid hydrogen tanks

In liquid hydrogen (LH2) storage tanks, the temperature difference between LH2 and the environment leads to the inevitable heat ingress into the storage tanks. Understanding the details of the thermal performance in LH2 storage tanks is necessary to minimize or avoid boil-off gas losses. This paper presents a thermodynamic non-equilibrium model to study the thermal differences between cylindrical and spherical LH2 tanks with the same volumetric capacity. The accuracy of the model is validated with experimental data obtained from cylindrical and spherical tanks. The numerical results show that, in self-pressurized tanks, a spherical geometry results in the lowest pressure increase rate. The pressure increase in horizontal, cylindrical tanks is slower than the corresponding increase in cylindrical tanks oriented vertically. The difference can be related to more effective heat transfer between the vapor and liquid phases in the horizontal cylindrical tanks. A higher initial liquid level increases the thermal mass of the liquid, which suppresses the evaporation rates due to larger heat requirements to warm and evaporate the liquid hydrogen. For tanks under atmospheric pressure, the boil-off gas rate is lowest in the spherical tank while the boil-off gas rates in the horizontal and vertical cylindrical tanks are almost the same. Under these conditions, and quasi-steady state, the total heat absorbed by the tanks is used to evaporate LH2. The spherical tank has the smallest surface area and thus the lowest evaporation rate and the lowest heat transfer from the environment. The evaporation rate is not affected by initial liquid levels.

Effects of operating temperature on Li-O2 battery with ionic liquid-based binary electrolyte

Awaiting a breakthrough, the Li-oxygen battery (LOB) is considered a promising candidate to meet the high energy demands in the future. Among various critical challenges which hamper its development, the mystery of the electrolyte with optimal properties remains unsolved to this day. In this study, we comprehensively investigated the effects of operating temperature (20C, 40 °C and 60 °C) on the electrochemical performance of LOBs incorporated with room temperature ionic liquid (RTIL) and organic solvent binary electrolyte. We designed and investigated 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2C1im][Tf2N]) RTIL and dimethyl sulfoxide (DMSO) organic solvent at various volume ratios ((4:1), (1:1), (1:4)). Among the binary electrolytes, ([C2C1im][Tf2N]/DMSO (1:4)) delivered the highest discharge capacities of 3.70 Ah g− 1 (20 °C), 4.0 Ah g− 1 (40 °C) and 3.65 Ah g− 1 (60 °C) as compared with pure [C2C1im][Tf2N] and DMSO. Cycling stability tests showed superior stability of the binary electrolyte ([C2C1im][Tf2N]/DMSO (1:4)) irrespective of the operating temperature. From viscosity and ionic conductivity measurements (at 20–60 °C), [C2C1im][Tf2N]/DMSO (1:4) exhibited the highest ionic conductivity and the lowest viscosity compared with other binary electrolytes (even with pure electrolytes) at any given temperature. Cyclic voltammetry (CV) tests revealed the highest reaction rates for [C2C1im][Tf2N]/DMSO (1:4) binary electrolytes than pure electrolytes. The superior performance of [C2C1im][Tf2N]/DMSO (1:4) binary electrolyte was ascribed to enhanced stability against reactive intermediate species during oxygen reduction reaction (ORR), increased ionic conductivity, low viscosity (comparable with organic electrolytes), improved oxygen solubility, and relatively low evaporation rates.

Capping Layer Determined Self-assembly of Au-Ag Bimetallic Janus Nanoparticles at An Oil/Water Interface by Molecular Dynamics Simulations.

Bimetallic Janus nanoparticles (BJNPs) have gained more attention due to their unique catalytic and optical properties. The self-assembly of BJNPs is expected as an effective way to fabricate metamaterials suitable for different potential applications. However, the self-assembly dynamic process of BJNPs, which is key to achieving a controllable synthesis, is limited in both experimental and theoretical investigations. Herein, all-atom molecular dynamics (MD) simulations were employed to investigate the self-assembly process of 1-dodecanethiol (DDT)-decorated Au-Ag BJNPs at an oil-water interface. We demonstrate that DDT's van der Waals (vdW) interaction dominates the self-assembly process. BJNPs form close-packed structures at both fast and slow evaporation rates. Au-Ag BJNPs exhibit relatively larger rotations at a low evaporation rate than those at a high evaporation rate, suggesting that the evaporation rate influences the orientation of the Au-Ag BJNPs. BJNPs tend to orient their electric dipole moments toward the external electric field, according to the ab initio MD simulation results. Based on the energy comparison and model analysis, it is found that the parallel array is more stable than the antiparallel one for the Au-Ag BJNP arrays. The dipole-dipole interaction difference between the parallel and antiparallel BJNP arrays obtained according to dipole moment obtained from ab initio calculation is qualitatively consistent with that obtained from MD simulations, indicating that the dipole plays a decisive role in determining the orientation of the BJNP array. This work uncovers the self-assembly dynamic process of BJNPs, paving the way for future applications.

Effect of Partial Drip Irrigation Methods on Soil Moisture and Water Potential Distribution, Growth Characteristics and Yield of Maize

A field experiment was conducted during the autumn of 2021 at the Agricultural Research Department station / Abu Ghraib to evaluate the soil moisture, water potential distribution, and growth factors of maize crops under alternating and constant partial drip irrigation methods. In the experiment, two irrigation systems were used, surface drip irrigation (DI) and subsurface irrigation (SD); under each irrigation system, five irrigation methods were: conventional irrigation (CI), and 75 and 50% of the amount of water of CI of each of the alternating partial irrigation APRI75 and APRI50 and the constant partial irrigation FPRI75 and FPRI50 respectively. The results showed that the water depth for conventional irrigation (C1) was 658.3 and 579.4 mm for the DI and SD irrigation systems, respectively, and the irrigation depth was reduced to 18% when applied APRI75 and FPRI75 and 37% when applied APRI50 and FPRI50 respectively. The moisture distribution differed according to the irrigation method, and the SD provided a higher moisture content and lower water potential due to the lower evaporation rate from the soil surface. Also, the growth traits of maize varied according to the irrigation system and its methods. The SD system was significantly superior in the grain yield of maize with an increase of 5.4% compared with DI, and the alternating partial irrigation treatments were significantly superior to the constant partial irrigation. Keywords: Matric suction, Zea mays L., irrigation system, irrigation depth.

Hierarchical Co3S4 nanostructure coupling with macroporous nickel foam: A robust interfacial solar evaporator for efficient desalination and sustainable freshwater production

Interfacial solar water evaporation (ISWE) technology provides a green, energy-saving and economical way to sustainably produce freshwater from various water sources for addressing the impending water shortage. However, the low evaporation rate, complex manufacturing process and harmful surface salt accumulation for ISWE are still challenging and considerably restricted the practical applications. Herein, we design and fabricate a robust ISWE based on the hierarchical Co3S4 nanostructure as a photothermal absorber and three-dimensional (3D) nickel foam (NF) as a primary structure with macroporous networks. The as-fabricated Co3S4/NF not only introduces sufficient photothermal centers to convert solar energy into heat, but also provides abundant channels for water transportation and steam escape. The Co3S4/NF evaporator exhibits a high evaporation rate of 1.56 kg m−2 h−1 and a photothermal conversion efficiency up to 94.18 % under one-sun illumination. Moreover, such evaporator shows the long-term durability and good salt-resistant ability, which can sustainably produce freshwater from various water sources including seawater, saline water, lake water and other contaminated water. The photothermal Co3S4/NF evaporator would provide a promising platform for the production of drinkable water in a safe and sustainable manner.

The effect of Ir and Sc on the emission capacity of W–Ir matrix scandate cathodes prepared via a novel in situ method

The size and distribution of Sc2O3 in the composite powder precursor has great effect on the emission property of scandate cathode. By one-step in-situ synthesis method, the composite powder exhibits the structure of quasi-spherical Sc2O3 nanoparticles grown in situ on the surface of W/Ir grains, and the obtained W–Ir cathode with 3wt % Sc2O3 could provide the emission current density of 83.43 A/cm2 at 900 °Cb, which is higher than other W–Ir mixed matrix scandate cathodes and W matrix scandate cathode. The XRD results showed that the high emission ability depended on the high content of active phase α-Ba2ScAlO5 and low content of non-active phase BaAl2O4. In-situ TEM has been applied to observe the microstructure evolution of the cathode surface at high temperature for the first time. A serial change in the microstructural features of cathode surface and the migration of Ba, Sc and O on the substrate surface has been found, confirming the formation of Ba-Sc-O active layer. The first-principles calculations indicate that the active substances (Sc) are more stable (low adsorption energy of − 8.58 eV) on the IrW matrix cathode surface than on the tungsten matrix cathode surface, which is consistent with the low evaporation rate of the active substance detected by TFMS technique. Besides, the interaction between the active substance and the matrix was strengthened due to more electron transfer of Sc (1.88 e) and Ba (1.45 e), therefore lowering the work function. The feasible preparation technique makes such a cathode promising for applications in high-power microwave devices.

Polyester fiber bundle-based solar evaporator manufactured by dyeing for efficient desalination and zero liquid discharge

Interfacial solar desalination is a promising technology to address global freshwater scarcity. However, low evaporation rates, complex manufacturing processes, and poor salt resistance have hindered the practical application of solar evaporators. In this study, a three-dimensional (3D) solar evaporator named DB-PFB was developed by dyeing industrial dispersion black (DB) onto polyester fiber bundle (PFB). Vertical channels in the PFB rapidly transport water from the bottom to the top through the wicking effect. This, together with hydrophobic polyester fibers, prevents salt accumulation, ensures stable desalination performance and achieves zero liquid discharge. The 3D DB-PFB can utilize ambient energy and has a stable evaporation rate of about 2.60 kg m–2h−1 for desalination of 20 wt% brine at 1-solar intensity. Continuous evaporation allows the collection of salt crystals and dye wastes in the distillation tank. Long-term indoor and outdoor desalination experiments (about 150 h each) have proven the durability of the DB-PFB. 1 m2 DB-PFB can produce approximately 18 kg of freshwater per day from 20 wt% brine, meeting the daily drinking water needs of six adults. This efficient, easy-to-manufacture, and salt-resistant solar evaporator offers a feasible solution to alleviate global freshwater scarcity.

Reinforcing Pepper (&lt;em&gt;Capsicum annuum&lt;/em&gt;) Growth by Gypsum and Salicylic Acid under Salinity Stress

Purpose: Salinity stress negatively affects plant growth, which leads to a decline in the food source. Low rainfall and high water evaporation rates in some regions are serious problems in the field of agriculture. In saline soil, plants are unable to absorb water. The aim was to find some amendments to reduce the toxic effects of saline soil. Research Method: In this study, a pot experiment was performed to study the ameliorative role of gypsum (G; 0.38 g per 200 g of soil) and salicylic acid (SA was sprayed on the leaves at two different times) on pepper growth. Two concentrations of NaCl (50mM and 100mM) were used for irrigation every two days. After 18 days, some growth characteristics, including shoot and root length, dry and fresh weight, salt tolerance index, leaf surface area, and chlorophyll content, were evaluated.Findings: The results showed that the application of gypsum alone and with foliar spray of SA was effective in reinforcing the pepper seedlings under salinity stress, regardless of salt concentration. Research limitations: Limited availability of some advanced instruments to collect more data.Originality/value: The investigated ameliorator can be used to improve plant growth under salinity stress.

Effects of Operating Temperature on Li-O2 Battery with Ionic Liquid-Based Binary Electrolyte

The progress of rechargeable Li-O2 battery (LOB) is hampered due to the number of challenges its components present. Among various critical challenges, the choice of electrolyte has always been a bottleneck impeding the breakthrough in the development of LOB. Various electrolytes, including organic solvents and room-temperature ionic liquids (RTILs) have been developed and studied. Each electrolyte comes with various limitations, which restrict its application in the LOB. These include thermal and electrochemical stability, volatility, viscosity, flammability, capability to dissolve incoming oxygen, diffusivity, and ionic conductivity. Consequently, no electrolyte could be regarded as an ideal electrolyte. Nonetheless, efforts have been made to tune the physiochemical properties of the electrolyte by blending two or more miscible solvents. High thermal and electrochemical stability and negligible volatility of RTILs can be combined with high diffusivity and ionic conductivity of organic solvents by merely blending them with optimized volume ratios.In this study, we comprehensively investigated the effects of operating temperature (20°C, 40°C and 60°C) on the electrochemical performance of LOBs incorporated with RTIL and organic solvent binary electrolyte. We designed and investigated, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2C1im][Tf2N]) RTIL and dimethyl sulfoxide (DMSO) organic solvent at various volume ratios ((4:1), (1:1), (1:4)). Among the binary electrolytes, ([C2C1im][Tf2N]/DMSO (1:4)) delivered the highest discharge capacities of 3.70 Ah g-1 (20°C), 4.0 Ah g-1 (40°C) and 3.65 Ah g-1 (60°C) as compared with pure [C2C1im][Tf2N] and DMSO. Cycling stability tests showed superior stability of the binary electrolyte ([C2C1im][Tf2N]/DMSO (1:4)) irrespective of the operating temperature. From viscosity and ionic conductivity measurements (at 20-60°C), [C2C1im][Tf2N]/DMSO (1:4) exhibited the highest ionic conductivity and the lowest viscosity compared with other binary electrolytes and pure RTIL at any given temperature. Cyclic voltammetry (CV) tests revealed a higher reaction rate with [C2C1im][Tf2N]/DMSO (1:4) binary electrolytes than pure electrolytes. The superior performance of [C2C1im][Tf2N]/DMSO (1:4) binary electrolyte was ascribed to enhanced stability against reactive intermediate species during oxygen reduction reaction (ORR), increased ionic conductivity, low viscosity (comparable with organic electrolytes), improved oxygen solubility, and relatively low evaporation rates. The detailed results and discussion will be presented during the presentation.

Quasinormal modes and optical properties of 4-D black holes in Einstein Power-Yang–Mills gravity

This paper explores the impact of the Yang–Mills charge parameter and the exponent term on a 4D black hole solution in the Einstein Power-Yang–Mills theory. Through an investigation of the massless scalar quasinormal mode spectrum, black hole shadow, and emission rate, we have determined that the effects of these two parameters are opposite. Specifically, the Yang–Mills charge parameter causes an increase in the real quasinormal frequencies with a correspondingly smaller damping rate. It also results in a smaller black hole shadow and a lower evaporation rate.

When Coordination Polymers Meet Wood: From Molecular Design toward Sustainable Solar Desalination.

Solar-driven interfacial evaporation harnessing solar energy on a water surface provides a sustainable and economic means to efficiently capture freshwater from nontraditional water sources. Endowed with a hierarchical porous structure and mechanical stability, wood-based evaporators represent a renewable alternative to petroleum-based materials. Nonetheless, incidental inferiorities of a low evaporation rate and weak interfacial strength are challenging to overcome. Herein, we propose the usage of chemically stable coordination polymers (Ni-dithiooxamidato, Ni-DTA) as hydrophilic photothermal nanomaterials for the molecular design of robust wood-based evaporators with improved performance. In situ synthesis of Ni-DTA onto the channel wall of balsawood provides sufficient photothermal domains that localize the converted energy for facilitated interfacial evaporation. A rational control of methanol/dimethylformamide ratios enables the coexistence of 1D-nanofibers and 0D-nanoparticles, endowing Balsa-NiDTA with a high evaporation rate of 2.75 kg m-2 h-1 and an energy efficiency of 82% under one-sun illumination. Experimental and simulation results reveal that Ni-DTA polymers with strong hydration ability decrease the equivalent evaporation enthalpy induced by decreased H-bonding density of water molecules near the evaporation interface. The Balsa-NiDTA evaporator showed a high chemical stability, mainly due to the robust Ni-S/Ni-N bonds and the superior cellulose affinity of Ni-DTA. Furthermore, the Balsa-NiDTA evaporator shows an excellent antibacterial activity and low oil-fouling propensity. This work presents a facile and mild strategy to design chemically stable wood-based evaporators, contributing to highly efficient and sustainable solar desalination under harsh conditions.

Boosting Water Evaporation by Construction of Photothermal Materials with a Biomimetic Black Soil Aggregate Structure.

Solar-driven interfacial evaporation is considered an efficient way to get fresh water from seawater. However, the low evaporation rate, surface salt crystallization, and low energy collection of the photothermal evaporation layer limit its further application in an outdoor freshwater field. And the aggregate structure design of the material itself is often ignored in solar-driven water evaporation. Black soil (BS), with a unique soil aggregate structure, is rich in tubular pores, which can be used for multilevel sunlight utilization and good capillary water transport. Based on the extraordinary photothermal properties and pumping capacity of BS, a reasonable unidirectional salt-collecting device is designed, which can realize long-term collection of mineral salts and continuous evaporation of seawater and generate electric energy in the continuous evaporation. Inspired by the unique aggregate structure, the photothermal material doping of halloysite and nigrosin will simulate the generation of this aggregate structure and retain a good water transport effect while obtaining multistage utilization of sunlight. The solar-driven evaporation rate of a nigrosin-halloysite solar steam generator is 1.75 kg m-2 h-1 under 1 kW m-2 mimic solar radiation; it can achieve stable salt leaching-induced voltage generation of 240 mV. This work demonstrates not only a solar evaporator that can continuously achieve desalination but also the design strategy of BS-like aggregate photothermal materials, which promotes the development of low-cost resource recovery and energy generation for practical outdoor seawater desalination.