Environmental Relative Humidity Research Articles

Optimization of conventional-zeolite-synthesis from waste pumice for water adsorption

This research reports conventionally-synthesized-zeolites with comparatively large surface area (SSA) and water-uptake prepared solely from waste-pumice. Notably, the synthesis process avoided using additional commercial raw materials, organic templates, and high temperatures, so that the process was less costly and ecofriendly. To optimize the process, the synthesis time was varied, and the mixture of the raw material and alkaline solution was stirred for 12 h. The zeolite mother liquor was also recycled. Water adsorption experiments were carried out using gravimetric measurements. The Na-P1-rich zeolite product with an optimal water uptake of 0.256 g/g was synthesized after 48 h of hydrothermal activation (H). On the other hand, the product’s optimal SSA of 186 m2/g was achieved after 36H under similar conditions (rich in faujasite). Adsorption isotherms showed that water uptake increased with activation time and with the inclusion of mother liquor recycling. Furthermore, recycling resulted in a product with enhanced SSA compared to its precursor. Un-recycled products exhibited relatively high-water uptake both at low and high relative-pressure, while the recycled product had a high uptake at high relative pressure. All products could be used in adsorption heat pump (AHP) applications (air conditioning) suited for high relative humidity (RH) environments. However, high-synthesis-time non-recycled products could also work for low RH AHP applications.

Study on dosimetric characteristics of polycarbonate films irradiated by electron beam

In this study, the dosimetric characteristics (thickness applicability, dose linear response, signal fading characteristic, in-batch consistency, readout reproducibility, humidity dependence, and electron energy response) of engineering polycarbonate films irradiated by electron beam were studied using spectrophotometry. The results show that polycarbonate films of various thicknesses exhibit good dose linearity within their corresponding wavelength ranges. Specifically, the dose capture range of 0.3 mm polycarbonate film spans from 950 Gy to 1000 kGy. After irradiation, the net absorbance of polycarbonate films showed an exponential decline, which was dose-dependent. The average absolute deviation of net absorbance for polycarbonate films produced within the same batch is 1.49% at 100 kGy. After 15 repeated absorbance measurements, the coefficient of variation in net absorbance for the polycarbonate films is less than 1%. Additionally, the radiation response of the polycarbonate film is affected by the environment relative humidity (during irradiation and post-irradiation storage). At the same dose of 3.5-20 MeV electron beam irradiation, the net absorbance response deviation of polycarbonate films remains below 2.26%. These results provide a comprehensive reference for detecting high doses of electron beams using engineering polycarbonate films.

Neutron tomography and image registration methods to study local physical deformations and attenuation variations in treated archaeological iron nail samples

This study presents a preliminary examination of the effects of environment changes post-excavation on heavily corroded archaeological Roman iron nails using neutron tomography and image registration techniques. Roman nails were exposed to either a high relative humidity environment, or fast thermal drying as primary experiments to show the power of this imaging technique to monitor and quantify the structural changes of corroded metal artifacts. This research employed a series of pre- and post-treatment tomography acquisitions (time-series) complemented by advanced image registration methods. Based on mutual information (MI) metrics, we performed rigid body and affine image registrations to meticulously account for sample repositioning challenges and variations in imaging parameters. Using non-affine local registration results, in a second step, we detected localized expansion and shrinkage in the samples attributable to imposed environmental changes. Specifically, we observed local shrinkage on the nail that was dried, mostly in their Transformed Medium (TM), the outer layer where corrosion products are cementing soil and sand particles. Conversely, the sample subjected to high relative humidity environment exhibited localized expansion, with varying degrees of change across different regions. This work highlights the efficacy of our registration techniques in accommodating manual removal or loss of extraneous material (loosely adhering soil and TM layers around the nails) post-initial tomography, successfully capturing local structural changes with high precision. Using differential analysis on the accurately registered samples we could also detect and volumetrically quantify the variation in moisture and detect changes in active corrosion sites (ACS) in the sample. These preliminary experiments allowed us to advance and optimize the application of a neutron tomography and image registration workflow for future, more advanced experiments such as humidity fluctuations, corrosion removal through micro-blasting, dechlorination and other stabilization treatments.

Evaporation, spreading, and possible uptake of droplets on sorghum (Sorghum bicolor) and cowpea (Vigna unguiculata) leaves using an imaging-based technology.

Sprayed agrochemical droplets have a dynamic evolution on the leaf surface, undergoing changes in shape and volume due to spreading, evaporation, and adsorption. To better understand these processes, an accessible imaging-based experimental methodology is presented to precisely measure droplet spreading, evaporation, and potential uptake by a leaf within a controlled relative humidity environment. Laboratory experiments were conducted to determine the effect of hydrocarbon surfactants, accelerators (light mineral oil), and humectants (high fructose corn syrup) on droplet spread, evaporation, and potential uptake when applied to sorghum (Sorghum bicolor 'Tricker') and cowpea (Vigna unguiculata) leaves. Experiments on cowpea leaves showed uniform spreading and no change in evaporation compared to the predicted rate. In contrast, on sorghum leaves, results suggest that the volume loss rate exceeds the predicted evaporation rate (up to 23%), indicating a potential uptake by the leaves. Some accelerated dynamics on sorghum can be attributed to the lateral spreading observed on hairy leaves along the veins, increasing the contact area by an average of 65%. However, samples containing light mineral oil, typically considered an accelerant to aid in uptake, demonstrated the highest rate but exhibited minimal spreading. The study demonstrates how droplet composition affects droplet dynamics on waxy and hairy leaves by using an imaging-based methodology to measure evaporation rates, volume loss, contact angle, wetted area, and spreading behavior. The findings highlight some of the complex coupling between the crop protection product composition and droplet life cycle on a leaf. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Reconstructing the Surface of K2SiF6:Mn4+ Phosphors toward Enhanced Moisture Resistance for White LED Applications.

The K2SiF6:Mn4+ (KSFM) phosphor featuring efficient ultranarrow red emissions is an outstanding candidate for white light-emitting diode (WLED) applications. However, poor moisture resistance seriously affects its application performance. In this study, a two-step surface reconstruction strategy is proposed to dramatically enhance the moisture resistance of commercially available KSFM phosphors, involving treatment with H2NbF7 and subsequent hydrothermal treatment. The modified KSFM phosphor exhibits a high internal quantum efficiency (IQE) of 98.9% after the two-step surface treatment. Meanwhile, nearly 100% of the initial emission intensity is retained for the modified KSFM phosphor even after aging in high temperature (85 °C) and high relative humidity (85% RH) environments for 6 days, in sharp contrast to only 18.6% retention for the original KSFM phosphor. The relative emission intensity of the modified KSFM remains at 98.9% even after being immersed in water for 6 h. Additionally, the phosphor-converted LED fabricated with the modified KSFM phosphor demonstrated excellent long-term stability, retaining up to 97.9% of initial luminous efficacy after aging under 85 °C and 85% RH conditions for 500 h. The moisture-resistance mechanism is elucidated on the basis of spectroscopic analysis as well as structural and compositional characterization of the phosphor surface layer, which can be attributed to the formation of a robust Mn4+-rare shell with high crystalline quality following this two-step surface treatment. The findings contribute to the performance improvements of KSFM phosphors for industrial applications.

The role of diabatic heating/cooling in outer rainbands in the secondary eyewall formation and evolution in a numerically simulated tropical cyclone

In this study, the role of diabatic heating/cooling in outer rainbands (ORBs) in the formation and evolution of the secondary eyewall of a numerically simulated tropical cyclone (TC) is investigated. This is done through a series of sensitivity experiments under idealized conditions using a high-resolution cloud-resolving atmospheric model. The results show that artificially increasing diabatic heating in rainbands enhances convective activities in ORBs and leads to an earlier secondary eyewall formation (SEF), and later the faster weakening and earlier dissipation of the primary eyewall. Reducing diabatic heating in ORBs weakens the rainbands and delays the SEF but prolongs the duration of the double eyewall structure if the SEF occurs. Reducing diabatic cooling in ORBs enhances convective activity in rainbands but has little effect on convection in the primary eyewall prior to the SEF. However, it results in a widened eyewall structure and a stronger TC after the eyewall replacement. Increasing diabatic cooling in ORBs largely suppresses convection in rainbands and prohibits the SEF. These results demonstrate that diabatic heating/cooling in ORBs plays important roles in the SEF and evolution. Since diabatic heating/cooling in rainbands is sensitive to the near-core environmental relative humidity, our results demonstrate the critical importance of large-scale environmental moist condition to the formation and evolution of secondary eyewall in TCs. In addition, it is also found that when the area-averaged diabatic heating rate in ORBs becomes similar in magnitude to that in the primary eyewall, the secondary eyewall forms. Plain language summaryPrevious studies have demonstrated the importance of diabatic heating/cooling in outer rainbands to the structure and intensity changes of tropical cyclones (TCs) with a single eyewall. It is unclear whether and how diabatic heating/cooling in outer rainbands may affect the formation and evolution of the secondary eyewall in TCs. These issues have been addressed based on a series of sensitivity experiments under idealized conditions using a high-resolution atmospheric model. Results show that diabatic heating in outer rainbands is favorable for the secondary eyewall formation (SEF). Increasing diabatic heating in outer eyewall can lead to faster weakening and thus earlier dissipation of the primary eyewall. Diabatic cooling in outer rainbands suppresses convection in outer rainbands and prohibits the SEF. Since diabatic heating/cooling in outer rainbands is sensitive to the near-core environmental relative humidity, our results demonstrate the importance of the large-scale environmental moist condition to the SEF of TCs. We also found that when the area-averaged diabatic heating rate in outer rainbands becomes similar in magnitude to that in the primary eyewall, the secondary eyewall would form, which can be considered as a measure of the SEF in TCs. Key points1.Increasing diabatic heating in outer rainbands leads to earlier SEF, and faster weakening and earlier dissipation of the primary eyewall.2.Increasing diabatic cooling in outer rainbands suppresses convective activity in outer rainbands and is unfavorable for the SEF.3.When the area-averaged diabatic heating rate in outer rainbands and the eyewall become similar in magnitude, the secondary eyewall forms.

Influence of fungicide on soybean seed quality from delayed harvest and environment

AbstractField studies in 2019–2020 evaluated the influence of fungicide application on seed quality from delayed harvest (approx. 20, 30, and 44 days after optimum harvest timing, i.e., 13% seed moisture). Treatments included nofungicide, pydiflumetofen plus difenoconazole (13.7 fl oz/acre Miravis Top, Syngenta), or mefentrifluconazole plus pyraclostrobin plus fluxapyroxad (8 fl oz/acre Revytek, BASF). Effect of environment was investigated in both field (natural rainfall events) and environmentally controlled growth chambers (79°F or 90°F with 30% or 100% relative humidity and exposed for 48 or 96 h) for potential impacts on soybean [Glycine max (L.) Merr.] seed quality. Seed quality was based on a rating scale of 1 to 10 with 1 being seeds in good condition and 10 being seeds in poor condition, based on USDA reference images. Fungicide application had no effect on seed quality from delayed harvest or a saturated environment (100% relative humidity). Delaying harvest beyond approximately 20 days past optimum timing can result in reduced seed quality regardless of fungicide application (1.0 to 2.0 vs 4.0 to 8.1 rating). In addition, seedpod exposure averaged across temperature and relative humidity environments for as little as 96 h after optimum harvest timing can result in deteriorating seed quality issues (3.2 vs 1.4 rating) regardless of fungicide application. Results indicate that soybean harvest delayed 20 days after optimum timing and subjected to seasonal rainfall events or seedpods exposed to completely saturated conditions for 96 h associated with a tropical weather event will result in soybean seed quality deterioration regardless of fungicide application.

Rectangular bismuth oxychloride with high mid-wave infrared reflectance to strengthen radiative cooling performance

Abstract Radiative cooling materials (RCMs) based on polymers, that reflect solar irradiance (0.24–2.5 µm) strongly and emit radiation within atmospheric window (8–13 µm) intensively, have yielded obviously cooling performance. However, RCMs reported failed to realize high mid-wave infrared (2.5–8 µm) reflectance (i.e., spectral selectivity), which play an importance role in reject the radiation from ambient especially in high relative humidity. Thus, enhancing the reflectance of RCMs in mid-wave infrared can further strengthen the cooling effect in the environment of high relative humidity. Additive of fillers with high reflectance in mid-wave infrared is effective, low cost and convenient to modified the cooling performance polymeric RCMs. In this paper, micron rectangular bismuth oxychloride (BiOCl) powders were proposed and synthesized by hydrothermal method. And, rectangular BiOCl boasts excellent mid-wave infrared reflective capacity (85%). Then, rectangular BiOCl was added into the top-layer of flexible hierarchically porous complex membrane, and improved the reflectance of porous membrane within 2.5–8 µm from 48.3% to 58.1%. While the emittance of the obtained bilayer membrane within atmospheric window was hardly affected. The membrane with BiOCl exhibited better cooling performance in humid ambient (70%), demonstrating the importance of spectral selectivity experimentally. This work proposed an effective strategy to modify spectral selectivity of RCMs and it could expand the application of radiative cooling materials in hot and humid areas.

High relative humidity environment alleviates hypoxia-induced pulmonary arterial hypertension in mice

The environment has long been considered a crucial factor influencing the onset and progression of pulmonary diseases. Environmental therapy is also a practical treatment approach for many conditions. While research has explored the effects of factors like air pressure and oxygen concentration on pulmonary arterial hypertension (PAH), the impact of air humidity on PAH has not been investigated. In this study, we examined the role of different air humidity levels in a mouse model of PAH by controlling relative humidity. We induced PAH in mice using 10 % hypoxia, which led to significant thickening of the pulmonary vasculature, elevated right ventricular systolic pressure, and an increased right ventricular hypertrophy index (RVHI). However, when exposed to an environment with 80–95 % relative humidity, there was a marked reduction in the extent of pulmonary vascular remodeling, decreased vascular thickening, and lower RVHI, effectively preserving right heart function. Notably, changes in the Bmpr2/Tgf-β signaling pathway were significant and may play a pivotal role in this protective effect. In summary, our findings indicate that high relative humidity confers a protective effect on hypoxia-induced PAH in mice, providing novel insights into potential treatments for PAH.

Environmental factors affecting accelerated carbonation of recycled concrete aggregates using response surface methodology

To further enhance CO2 capture and sequestration in concrete waste, this study investigates the interaction of four environmental factors, i.e., temperature, relative humidity (RH), CO2 concentration and pressure on the accelerated carbonation of recycled concrete aggregates. 29 groups of accelerated carbonation tests are performed based on the Box-Behnken design. The effects of four factors on the carbonation percentage of recycled concrete aggregates (RCAs) are analyzed using a response surface methodology. A response surface model is obtained to characterize the experimental results. Additionally, three single-factor scenarios and three multi-factor coupled scenarios are employed to show the mechanisms affecting RCA carbonation and carbonation environments. Single factor analysis indicate that RH and CO2 concentration can significantly affect the carbonation of the RCA and the significance of the interactions follows the order of temperature - RH, RH - CO2 concentration and temperature - CO2 concentration. The microstructure of RCAs during carbonation is further studied and presented.

Relative humidity sensor based on a nano-film deposited LPFG with hydrophilic polymer composite coating

A novel high-performance relative humidity (RH) sensor is proposed by using a hydrophilic polymer composite film-coated nano-film deposition deposited long-period fiber grating (LPFG). A high refractive index (RI) TiO2 nano-film is deposited on the LPFG as an inner layer. The film thickness is selected to maximize the surrounding refractive index (SRI) sensitivity of the grating when the SRI is approaching the cladding index. A composite film made of polyvinyl alcohol (PVA) and polyethylene glycol (PEG) is used as the an external humidity-to-RI transducer. The concentration and proportion of the PVA/PEG solutions are appropriately chosen to tune the refractive index (RI) RI of the polymer coating to the transition range during the RH varying from 60 % to 95 %. For the LPFG coated with two layers film, the a RH sensitivity up to 3.3 nm/% is achieved. The variation in RH is found to have a linear response. The proposed device offers a reliable alternative for higher RH environment sensing.

Integrating self-hygroscopic hydrogel electrolyte and porous electrode for supercapacitor operating in variable humidity environments

The application of supercapacitors (SCs) based on the conventional polyvinyl alcohol‑potassium hydroxide (PVA-KOH) polymer electrolyte is challenged in variable humidity environments, especially in low relative humidity (RH) environments. Herein, taking advantage of the high ionic conductivity and strong hygroscopicity of highly concentrated KOH solutions, we have prepared a hygroscopic hydrogel polymer electrolyte composed of sodium alginate (SA)/PVA/poly(acrylic acid) (PAA)-KOH. The SA/PVA/PAA-KOH gel electrolyte exhibits high ionic conductivity, superior water retention and even water adsorption capability. A three-dimensional CoCu-layered double hydroxide/zeolitic imidazole framework-67 (CuCo-LDH/ZIF-67) porous electrode has also been prepared for the construction of the high-performance SC operating in variable RH environments. The CuCo-LDH/ZIF-67 porous electrode allows deep penetration of the self-hygroscopic electrolyte, facilitating electron/ion diffusion and providing fast water transport channels. As a result, our asymmetric SC show significantly improved electrochemical performance than that of SC based on conventional PVA-KOH electrolyte under different RH environments. This integration strategy can advance the practical application of SC in extreme environments.

Thermodynamic water adsorption analysis of biodegradable films based on corn starch-chitosan added with triblock copolymers

Adding triblock copolymers to hydrophilic films is an option to improve the functional properties and water resistance under high equilibrium relative humidity (RHeq) environments. Sorption isotherms of corn starch-chitosan based films added with triblock copolymers (L64 and P123) measured at 4, 20, and 36 °C were fitted using the Guggenheim-Anderson-De Boer equation. Thermodynamic analysis allowed allocating the minimum integral entropy value between 0.09 and 0.50 of water activity. The compensation enthalpy-entropy showed that the entropy driven the process at low water activities (0.10–∼0.33) and the enthalpy driven the water sorption at high water activities (∼0.33–∼0.90).

Inorganic-Derived 0D Perovskite Induced Surface Lattice Arrangement for Efficient and Stable All-Inorganic Perovskite Solar Cells.

The inverted inorganic CsPbI3 perovskite solar cells (PSCs) are prospective candidates for next-generation photovoltaics owing to inherent robust thermal/photo-stability and compatibility for tandems. However, the performance and stability of the inverted CsPbI3 PSCs fall behind the n-i-p counterparts due to poor energetic alignment and abundant interfacial defect states. Here, an inorganic 0D Cs4PbBr6 with a good lattice strain arrangement is implemented as the surface anchoring capping layer on CsPbI3. The Cs4PbBr6 perovskite induces enhanced electron-selective junction and thus facilitates efficient charge extraction and effectively inhibits non-radiative recombination. Consequently, the CsPbI3 PSCs with Cs4PbBr6 demonstrate the highest power conversion efficiency (PCE) of CsPbI3-based inverted PSCs, reaching 21.03% PCE from a unit cell and 17.39% PCE from a module with a 64 cm2 aperture area. Furthermore, the resulting devices retain 92.48% after 1000h under simultaneous 1-sun and damp heat (85°C / 85% relative humidity) environment.

Biolaminates as an Example of Upcycling Product with Keratin Flour-Research and Thermal Properties Modeling.

Keratin waste, including keratin powder, is a significant byproduct of the poultry processing and meat industries. It is a major contributor to waste management problems due to its volume and the environmental pollutants that it can produce. The disposal of keratin waste is challenging due to the potential for odors and pathogens to enter the soil and water. The aim of this work is to present the possibility of using waste materials in accordance with the principles of upcycling and producing fully valuable products. In this research, the author focuses on the production and research of textile multilayer laminates using keratin flour that had been previously considered waste material. New textile composites should be characterized by increased thermal insulation properties with constant comfort in use. This research determines the physiological comfort interpreted as the state of the human-laminate system, which maintains the conditions of comfort in human perception, i.e., constant temperature and humidity of the body under changing conditions of a relative humidity environment.

The manufacture of natural hydraulic limes: Influence of raw materials' composition, calcination and slaking in the crystal-chemical properties of binders

This study aims to achieve an in-depth understanding of the manufacturing process of natural hydraulic lime (NHL) by assessing the influence of raw materials' chemical- mineralogical composition and the effect of the slaking process. NHLs with variable hydraulicity were manufactured using 56 raw materials from carbonate outcrops in Andalusia (Spain). This study shows that siliceous limestones with microcrystalline quartz generate hydraulic phases after calcination. However, when the amount of this reactive silica exceeds 18% by weight, CaO is not formed, and only calcium silicates appear. It was also found that slaking of NHL leads to partial hydration of the most reactive calcium silicates, reducing the expected reactivity of the lime. Instead, exposure of NHL quicklimes to environmental relative humidity promotes the formation of disordered portlandite and reduces the partial hydration of hydraulic phases. Our findings demonstrate that standard slaking can be replaced by alternative methods for the studied binders.

Managing Green and Sustainable Technologies: Climate-Informed Corrosion Prediction for Steel Structures

The unpredictability of atmospheric circumstances is one of the major elements that contribute to the capability to anticipate the corrosion growth in metal structures over time accurately. Climate shifts can potentially modify the long-term attributes of these factors throughout the operational life of metal structures, both those currently in existence and those newly developed. The impact of climate irregularity on the probabilistic nature of atmospheric variables, which significantly impact corrosion situations, can add intricacy to corrosion predictions in these constructions. This project presents an incorporated framework to quantify the impact of climate alteration on the corrosion rates of steel structures in Jordan. It considers the changes in environmental conditions, specifically temperature, relative humidity, and wind speed, and their impacts on atmospheric corrosion. Global Climate Models are employed to assess the long-term effects of climate transformation on these environmental circumstances. An analytical model for anticipating corrosion rate is integrated with climate transformation models to predict modifications in the corrosion rates of steel parts relative to historical situations. This project also examines the impact of climate transformation on the fluctuations of these climatic parameters and offers a contrast between historical data and projected conditions across the country. The findings indicate a significant increase in corrosion rates across Jordan, which calls for localized green building codes and standards to ensure that future infrastructure is sustainable and capable of withstanding the new climatic norms. This approach addresses the immediate challenges posed by climate change and contributes to the broader goals of sustainable urban development and managing green technology adoption in Jordan. Doi: 10.28991/CEJ-2024-010-08-016 Full Text: PDF

Investigation of the effect of relative humidity on micro lime consolidation of degraded earthen structures

Micro lime, hydrated lime (Ca (OH)2) with particle sizes of 1-3μ dispersed in isopropanol, can be used to reinforce deteriorated earthen structures. The consolidation effect depends on the amount of moisture present in the structure or in the ambient air. This study investigates the influence of different levels of relative humidity (RH) on the consolidation effect of micro lime on earthen structures, the chemical processes responsible for the consolidation and the physical changes to the structure. The aim is to gain a deeper understanding of the underlying chemical reactions and to identify a potential limit to the applicability of this consolidation method in low RH environments. The fact that many of these sites are located in arid climates greatly influences the practical application of micro lime in the conservation of historical earthen structures. To characterize the consolidation effect of micro lime, unconfined compressive strength and exposure to wet and dry cycles were used. The properties of the reaction products and the bonding between soil particles and micro lime were investigated using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). At RH levels of 25%, 45%, 65% and 90%, the unconfined compressive strength (UCS) and the modulus of deformation at 50% strength (E50) of the micro lime-reinforced specimens demonstrated an increase with humidity. This led to a significant improvement in their ability to resist the effects of dry–wet cycles. Results from thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) indicate that micro lime interacts with the soil matrix via carbonation, with the reaction rate increasing with humidity. At 25% RH, vaterite was produced and residual free lime was observed, whereas at humidity levels of 45% and above, the reaction yielded vaterite and aragonite. The lime treatment did not significantly alter the pore structure of the soil specimens. The total porosity of the specimens was only slightly reduced, with the main effect of the lime treatment being a reduction in the number of large pores.

Design of Mineral Oil/Stearic Acid Hybrid Coatings for Reducing Hygroscopicity of Ammonium Nitrate.

Ammonium nitrate (AN) is a very promising high-energy oxidant for use in solid propellants but suffers from serious hygroscopicity. While various coating materials (e.g., surfactants) have been employed to mitigate the hygroscopicity of AN, the interaction mechanisms between AN and these coatings remain inadequately understood. Here, we report the preparation of a mineral oil/stearic acid (MO/SA) hybrid coating that significantly reduces the hygroscopicity of AN. The hygroscopicity of AN is efficiently inhibited through interactions between the NH4+ of AN molecules and the -COOH of SA molecules, resulting in the formation of a dense and hydrophobic coating. Additionally, the defects in the SA coating are compensated for by the MO film. Consequently, MO/SA@AN particles with a low mass ratio of the coating (1.35 wt %) exhibit a low hygroscopicity of 7.24% after being kept in a 90% relative humidity environment at 20 °C for 24 h, representing a 48.10% decline of the hygroscopicity. Furthermore, MO/SA@AN maintains a high rate of hygroscopicity decline, at 29.5%, even at 35 °C and 90% RH after 24 h. Additionally, the hybrid coating effectively accelerates the thermal decomposition reactions of AN. This study provides valuable insights into the development of hybrid coatings with excellent antihygroscopic properties for AN.

Optimal Design of Air Treatment for an Adsorption Water-Harvesting System

In some areas where access to water is difficult, such as arid regions, it is a feasible measure to acquire water from the air. In this context, a system for water harvesting from the air was designed and manufactured. In order to find the optimal operation parameters of the system, the humidity–enthalpy diagram and the dehumidifier computation software (V2.0, Win7) were adopted for the optimization work. The air treatment process of the system was analyzed and calculated by using the professional software provided by the dehumidifier company. Operation modes of ‘powerful mode’ and ‘economic mode’ were defined in the computation work, which are represented by the water production amount and efficiency (water production per power consumption), respectively. According to computation analysis, the relationships between the main performance indicators and the system design/operation parameters were obtained. By considering the heating power limitation of the system, the wheel dehumidifier rotation speed of 8 rph (revolutions per hour), zonal area ratio of Ap/Ar = 2, and the optimal airflow ratios in different relative humidity (RH) environments, together with the outlet air parameter settings of the surface cooler, were finally defined.