Comparative analysis of sleep parameters and structures derived from wearable flexible electrode sleep patches and polysomnography in young adults.

Polysomnography (PSG) is the gold standard for clinical sleep monitoring, but its cost, discomfort, and limited suitability for continuous use present challenges. The flexible electrode sleep patch (FESP) emerges as an economically viable and patient-friendly solution, offering lightweight, simple operation, and self-applicable. Nevertheless, its utilization in young individuals remains uncertain. The objective of this study was to compare sleep data obtained by FESP and PSG in healthy young individuals and analyze agreement for sleep parameters and structure classification. Overnight monitoring with FESP and PSG recordings in 48 participants (mean age: 23 yr) was done. Correlation analysis, Bland-Altman plots, and Cohen's kappa coefficient assessed consistency. Sensitivity, specificity, and predictive values compared classification against PSG. FESP showed strong correlation and consistency with PSG for sleep monitoring. Bland-Altman plots indicated small errors and high consistency. Kappa values (0.70-0.84) suggested substantial agreement for sleep stage classification. Pearson correlation coefficient values for sleep stages (0.75-0.88) and sleep parameters (0.80-0.96) confirm that FESP has a strong application. Intraclass correlation coefficient yielded values between 0.65 and 0.97. In addition, FESP demonstrated an impressive accuracy range of 84.12-93.47% for sleep stage classification. The FESP also features a wearable self-test program with an error rate of no more than 8% for both deep sleep and wake. In young adults, FESP demonstrated reliable monitoring capabilities comparable to PSG. With its low cost and user-friendly design, FESP is a potential alternative for portable sleep assessment in clinical and research applications. Further studies involving larger populations are needed to validate its diagnostic potential.NEW & NOTEWORTHY By comparison with PSG, this study confirmed the reliability of an efficient, objective, low-cost, and noninvasive portable automatic sleep-monitoring device FESP, which provides effective information for long-term family sleep disorder diagnosis and sleep quality monitoring.

Systematic review and meta-analysis of probiotics in the treatment of allergic rhinitis.

BACKGROUND: The purpose of this meta-analysis is to systematically evaluate the efficacy of probiotics on allergic rhinitis (AR). METHODS: Collecting randomized controlled trials (RCTs) with probiotics as intervention measures for AR, two researchers independently screened the literature, extracted the data and evaluated the methodological quality of the included studies, and used RevMan 5.3 software for meta-analysis to observe the effects of probiotics on Rhinitis Quality of Life (RQLQ) scores, Rhinitis Total Symptom Scores (RTSS), blood eosinophil count, total and antigen-specific serum immunoglobulin E (IgE) levels by using the fixed- or the random-effects model to calculate the pooled risk for significant heterogeneity. RESULTS: A total of 2708 patients were included in 30 RCTs. Meta-analysis results showed that the RQLQ global scores (mean difference [MD] = -9.43; P < 0.00001), RQLQ nasal scores (MD = -1.52; P = 0.03), and RTSS nasal scores (MD = -1.96; P = 0.02) significantly improved in the probiotic group when compared with those in the placebo group. There was no significant difference in blood eosinophil count (MD = -0.09; P=0.82), RQLQ eye scores (MD = -1.45; P = 0.07), RTSS global scores (MD = -2.24; P = 0.26), RTSS eye scores (MD = -0.39; P = 0.31), total and antigen-specific serum IgE levels (MD = -0.04; P = 0.7 and MD = -0.08; P = 0.81) between the probiotic and the placebo group. CONCLUSION: Compared with the placebo group, the quality of life and symptoms of patients with AR significantly improved in the probiotic group, thus providing a new potential method for the application of probiotics in AR. However, because of the limited evidence for the current study outcomes, the heterogeneity of research, and the differences in research results, more high-quality studies are needed to in the future.

Closing CO2 Loop in Biogas Production: Recycling Ammonia As Fertilizer.

We propose and demonstrate a novel system for simultaneous ammonia recovery, carbon capture, biogas upgrading, and fertilizer production in biogas production. Biogas slurry pretreatment (adjusting the solution pH, turbidity, and chemical oxygen demand) plays an important role in the system as it significantly affects the performance of ammonia recovery. Vacuum membrane distillation is used to recover ammonia from biogas slurry at various conditions. The ammonia removal efficiency in vacuum membrane distillation is around 75% regardless of the ammonia concentration of the biogas slurry. The recovered ammonia is used for CO2 absorption to realize simultaneous biogas upgrading and fertilizer generation. CO2 absorption performance of the recovered ammonia (absorption capacity and rate) is compared with a conventional model absorbent. Theoretical results on biogas upgrading are also provided. After ammonia recovery, the treated biogas slurry has significantly reduced phytotoxicity, improving the applicability for agricultural irrigation. The novel concept demonstrated in this study shows great potential in closing the CO2 loop in biogas production by recycling ammonia as an absorbent for CO2 absorption associated with producing fertilizers.

Technoeconomic Assessment of an Advanced Aqueous Ammonia-Based Postcombustion Capture Process Integrated with a 650-MW Coal-Fired Power Station.

Using a rigorous, rate-based model and a validated economic model, we investigated the technoeconomic performance of an aqueous NH3-based CO2 capture process integrated with a 650-MW coal-fired power station. First, the baseline NH3 process was explored with the process design of simultaneous capture of CO2 and SO2 to replace the conventional FGD unit. This reduced capital investment of the power station by US$425/kW (a 13.1% reduction). Integration of this NH3 baseline process with the power station takes the CO2-avoided cost advantage over the MEA process (US$67.3/tonne vs US$86.4/tonne). We then investigated process modifications of a two-stage absorption, rich-split configuration and interheating stripping to further advance the NH3 process. The modified process reduced energy consumption by 31.7 MW/h (20.2% reduction) and capital costs by US$55.4 million (6.7% reduction). As a result, the CO2-avoided cost fell to $53.2/tonne: a savings of $14.1 and $21.9/tonne CO2 compared with the NH3 baseline and advanced MEA process, respectively. The analysis of energy breakdown and cost distribution indicates that the technoeconomic performance of the NH3 process still has great potential to be improved.

Innovative use of membrane contactor as condenser for heat recovery in carbon capture.

The gas-liquid membrane contactor generally used as a nonselective gas absorption enhancement device is innovatively proposed as a condenser for heat recovery in liquid-absorbent-based carbon capture. The membrane condenser is used as a heat exchanger to recover the latent heat of the exiting vapor from the desorber, and it can help achieve significant energy savings when proper membranes with high heat-transfer coefficients are used. Theoretical thermodynamic analysis of mass and heat transfer in the membrane condensation system shows that heat recovery increases dramatically as inlet gas temperature rises and outlet gas temperature falls. The optimal split mass flow rate is determined by the inlet gas temperature and the overall heat-transfer coefficient in the condensation system. The required membrane area is also strongly dependent on the overall heat-transfer coefficient, particularly at higher inlet gas temperatures. Mass transfer across the membrane has an insignificant effect on heat transfer and heat recovery, suggesting that membrane wetting may not be an issue when a membrane condenser is used for heat recovery. Our analysis provides important insights into the energy recovery performance of the membrane condensation system as well as selection of operational parameters, such as split mass flow rate and membrane area, thickness, and thermal conductivity.

Biogas slurry purification-lettuce growth nexus: Nutrients absorption and pollutants removal.

As a main by-product of anaerobic digestion in biogas plants, biogas slurry contains a high concentration of mineral elements (such as ammonia­nitrogen and potassium) and chemical oxygen demand (COD). So determining how to dispose the biogas slurry in a harmless and value-added ways is crucial from the perspective of ecological and environmental protections. This study explored a novel nexus between biogas slurry and lettuce, in which the biogas slurry was concentrated and saturated with carbon dioxide (CO2) to serve as a hydroponic solution for lettuce growth. Meanwhile, the lettuce was used to purify the biogas slurry through removing pollutants. Results showed that when concentrating the biogas slurry, the total nitrogen and ammonia nitrogen contents in the biogas slurry decreased with the increase of concentration factor. The CO2-rich 5-time-concentrated biogas slurry (CR-5CBS) was screened as the most suitable hydroponic solution for lettuce growth after comprehensively considering the nutrient element balance, energy consumption of concentrating the biogas slurry and CO2 absorption performance. The quality of lettuce cultivated in CR-5CBS was comparable to that of the Hoagland-Arnon nutrient solution in terms of physiological toxicity, nutritional quality, and mineral uptake. Obviously, the hydroponic lettuce could effectively utilize the nutrients in CR-5CBS to purify CR-5CBS, meeting the standard of reclaimed water quality for agricultural reuse. Interestingly, when the same yield of lettuce is targeted, using CR-5CBS as the hydroponic solution to cultivate lettuce can save about US $151/m3-CR-5CBS for lettuce production compared to the Hoagland-Arnon nutrient solution. This study might provide a feasible method for high-value utilization and harmless disposal of biogas slurry.

Metal Oxyhydroxide Catalysts Promoted CO2 Absorption and Desorption in Amine-Based Carbon Capture: A Feasibility Study.

The huge energy penalty of CO2 desorption is the greatest challenge impeding the commercial application of amine-based CO2 capture. To deal with this problem, a series of metal oxide and oxyhydroxide catalysts were synthesized in this study to kinetically facilitate the CO2 desorption from 5.0 M monoethanolamine (MEA). The effects of selected catalysts on CO2 absorption kinetics, CO2 absorption capacity, CO2 reaction enthalpy, and desorption duty reduction of 2.0 M MEA were investigated by a true heat flow reaction calorimeter to access the practical feasibility of the catalytic CO2 desorption. The kinetic study of catalytic CO2 desorption was also carried out. CO2 desorption chemistry, catalyst characterization, and structure-function relationships were investigated to reveal the underlying mechanisms. Results show that addition of the catalyst had slight effects on the CO2 absorption kinetics and CO2 reaction enthalpy of MEA. In contrast, the CO2 desorption efficiency greatly increased from 28% in reference MEA to 52% in ZrO(OH)2-aided MEA. Compared to the benchmark catalyst HZSM-5, ZrO(OH)2 exhibited a 13% improvement in CO2 desorption efficiency. More importantly, compared to the reference MEA, the CO2 desorption duties of ZrO(OH)2 and FeOOH-aided MEA significantly reduced by 45 and 47% respectively, which are better than those of most other reported catalysts. The large surface area, pore volume, pore diameter, and amount of surface hydroxyl groups of ZrO(OH)2 and FeOOH afforded the catalytic performance by promoting the adsorption of alkaline speciation (e.g., MEA and HCO3 -) onto the particle surface.

Enhancing the Ammonia Selectivity by Using Nanofiber PVDF Composite Membranes Fabricated with Functionalized Carbon Nanotubes.

Conventional hydrophobic membrane-based membrane distillation (MD) has been applied for ammonia recovery from an anaerobic digestion (AD) effluent. However, the typical hydrophobic membranes do not have selectivity for ammonia and water vapor, which results in high energy consumption from the water evaporation. To enhance the selectivity during the ammonia recovery process, the functionalized carbon nanotubes (CNTs)/polyvinylidene fluoride (PVDF) nanofiber membranes were fabricated by electrospinning, and the effects of different CNTs and their contents on the performance of nanofiber membranes were investigated. The results indicate that CNTs can be successfully incorporated into nanofibers by electrospinning. The contact angles of the composite membrane are all higher than those of commercial membrane, and the highest value 138° can be obtained. Most importantly, under the condition of no pH adjustment, the ammonia nitrogen transfer coefficient reaches the maximum value of 3.41 × 10-6 m/s, which is about twice higher than that of commercial membranes. The ammonia separation factor of the carboxylated CNT (C-CNT) composite membrane is higher than that of the hydroxylated CNT(H-CNT) composite membrane. Compared with the application of the novel C-CNT composite membrane, the ammonia separation factor is 47% and 25% higher than that of commercial and neat PVDF membranes. This work gives a novel approach for enhancing ammonia and water selectivity during AD effluent treatment.

Simultaneous biogas upgrading, CO2 sequestration, and biogas slurry decrement using biomass ash.

A novel system for simultaneous biogas upgrading, CO2 sequestration, and biogas slurry decrement was established by adding biomass ash into biogas slurry to form a renewable CO2 mixture absorbent. After CO2 saturation, the CO2-rich mixture absorbent could be applied for plant growth. When the mass ratio of liquid to solid was 4:1, CO2 absorption capacity of this mixture absorbent reached up to 97.33 g-CO2/kg-biomass-ash, which was about 135% higher than that of the biomass ash-water mixture. The highest value of 129.94 g-CO2/kg-biomass-ash was obtained at a liquid-solid ratio of 99:1. When the TS concentration of anaerobic digestion feedstock was higher than 16 wt% and the water content of CO2-rich absorbent was about 50 wt%, more than 80% of biogas slurry can be adsorbed by the biomass ash. If the biomass ash with a CO2 absorption capacity of 100 g-CO2/kg was adopted and its transportation distance was less than 45 km, the biogas upgrading cost could be lower than the global average level (about RMB¥ 0.7/Nm3-biogas) when using the novel system proposed in this study.

A new approach for biogas slurry disposal by adopting CO2-rich biogas slurry as the flower fertilizer of Spathiphyllum: Feasibility, cost and environmental pollution potential.

A new approach for biogas slurry disposal was put forward in this study through converting biogas slurry to the organic fertilizer of Spathiphyllum. The biogas slurry was firstly concentrated by vacuum distillation to reduce its volume by 80% who is called 5CBS, and then CO2 saturated to reduce its pH to about 6.50 ± 0.20. With or without adding the exogenetic Ca, Mg and P nutrients, CO2-rich 5CBS (i.e., CR-5CBS) was adopted as the root or foliar fertilizer to cultivate Spathiphyllum. Additionally, the commercial Spathiphyllum fertilizer was also experimented as a control. Results showed that the cases adopting CR-5CBS as the root or foliar fertilizer can obtain the agronomic traits and ornamental values of Spathiphyllum better those irrigated by the commercial fertilizer. Exogenetic nutrients added into CR-5CBS can lead to a decreased dead leaf number of Spathiphyllum, an enhanced N assimilation performance, however only a slightly improved assimilation performance of Ca, Mg and P. In terms of the fertilizer economy, CR-5CBS without exogenetic nutrient addition may be a promising for replacing the commercial Spathiphyllum fertilizer in the future. Economic and environmental pollution potential (EPP) analyses indicated that treating biogas slurry as the organic flower fertilizer can achieve a high net profit with about $ 28.89/m3-biogas slurry and a negative EPP value (-3.9), showing its profitability and environmental friendliness.

Removal of methylene blue from aqueous solution by cattle manure-derived low temperature biochar.

Biochar is a low cost and renewable adsorbent which can be used to remove dye from wastewater. Cattle manure-derived low temperature biochar (CMB) was studied to remove methylene blue (MB) from aqueous solution in this paper. The effect of factors including initial concentration of MB, dosage, contact time, and pH on the adsorption properties of MB onto biochar were studied. Characterization of the CMB and MB adsorbed on CMB was performed using techniques including BET, FTIR and SEM. The adsorption isotherm, kinetics, thermodynamics and mechanism were also studied. The results showed the equilibrium data were well fitted to the Langmuir isotherm model, and the saturation adsorption capacity of CMB200 was 241.99 mg g-1. Pseudo-second order kinetics was the most suitable model for describing the adsorption of MB onto biochar. The adsorption thermodynamics of MB on biochar showed that the adsorption was a spontaneous and endothermic process. Through zeta potential measurement, Boehm titration, cation exchange, deashing and esterification experiments, the importance of ash to adsorption was verified, as well as the adsorption mechanism. The adsorption mechanism of MB on CMB200 involved cation exchange, electrostatic interaction, hydrogen bonding, physical effects and others. This work shows that CMB200 holds promise to act as an effective adsorbent to remove MB in wastewater.

Effect of alkali and alkaline earth metal species on the combustion characteristics of cattle manures.

This study investigates the effects of alkali and alkaline earth metal (AAEM) species on the combustion characteristics of cattle manures (CM). Different AAEM species (K, Na, Ca, and Mg) were mixed with CM and deashing CM (D-CM) samples. The combustion characteristics of raw and char samples were compared. The effects of AAEM species on CM char were analyzed based on the structural characteristics of the char sample. Results show that K and Na exert a positive effect, and this effect varies depending on the addition amount. Ca and Mg also exhibit a positive effect, but this effect does not change with the addition amount. The positive effect of K, Na, and Ca is related to the decrease in graphitization degree and increase in specific surface area. However, the positive effect of Mg is negligible. In conclusion, CM can be mixed with fuels containing K or Na in an appropriate ratio. The amount of Ca to be mixed with fuels has no specific requirement, whereas that of Mg to be mixed with fuels should be controlled.

An alternative parameter to characterize biogas materials: Available carbon-nitrogen ratio.

Available carbon-nitrogen ratio (AC/N) was proposed as an alternative parameter for evaluating the potential of biogas materials in this paper. In the calculation of AC/N ratio, only the carbon that could be effectively utilized in anaerobic digestion (AD) process is included. Compared with total C/N, AC/N is particularly more suitable for the characterization of biogas materials rich in recalcitrant components. Nine common biogas materials were selected and a series of semi-continuous tests for up to 110days were carried out to investigate the source of available carbon and the relationship between AC/N and the stability of AD process. The results showed that only the carbon existing in proteins, sugars, fat and hemicelluose should be considered as available carbon for anaerobic microbes. Besides, the optimal AC/N for semi-continuous AD process was preliminarily determined to be 11-15. Taken together, our results demonstrate that AC/N is more effective than total C/N in the evaluation of the potential performance of AD process.

Enhancing ethanol production from thermophilic and mesophilic solid digestate using ozone combined with aqueous ammonia pretreatment.

Pretreatment with ozone combined with aqueous ammonia was used to recover residual organic carbon from recalcitrant solid digestate for ethanol production after anaerobic digestion (AD) of rice straw. Methane yield of AD at mesophilic and thermophilic conditions, and ethanol production of solid digestate were investigated. The results showed that the methane yield at thermophilic temperature was 72.2% higher than that at mesophilic temperature under the same conditions of 24days and 17% solid concentration. And also the ethanol production efficiency of solid digestate after thermophilic process was 24.3% higher than that of solid digestate after mesophilic process. In this study, the optimal conditions for integrated methane and ethanol processes were determined as 55°C, 17% solid concentration and 24days. 58.6% of glucose conversion, 142.8g/kg of methane yield and 65.2g/kg of ethanol yield were achieved, and the highest net energy balance was calculated as 6416kJ/kg.

[CO2 absorption and regeneration performance of a natural amino acid and its potassium salt].

In order to decrease the solvent loss due to amine volatilization and oxidative degradation and reduce the risk of environmental pollution resulting from amine volatilization, amino acid salts with negligible volatility and better resistance to oxidative degradation may be considered as the alternative during the course of CO2 capture. So, experimental study on CO2 absorption and regeneration characteristics of L-arginine and potassium argininate (PA) was put forward in this study based on the CO2 absorption rate and heating regeneration rate at ambient pressure. And the influences of absorbent mass concentration, reaction temperature and absorption-regeneration cycles on CO2 absorption performance of L-arginine and PA were also investigated, which were used to compare with the typical absorbents including monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA). Results showed that among all the five absorbents, PA had the highest CO2 absorption rate of 24.5 x 10(-3) mol x (L x min)(-1) and CO2 loading capacity of 1.99 mol x mol(-1), which were 2.1% and 290.2% higher than MEA with the same mass concentration, respectively. The results also showed that CO2 absorption rate of PA and MEA at 40 degrees C was the highest compared to other temperatures. In addition, although CO2 loading of lean PA solution was slightly higher than that of MEA under the same regeneration conditions, 72.8% CO2 in the rich PA solution can be released, which is 19% higher than that of MEA. After three absorption-regeneration cycles, CO2 absorption capacity of 10% PA was found to be approximate 1.03 mol x mol(-1), which is 255.2% higher than MEA. Furthermore, L-arginine was found to have the stronger CO2 absorption capacity, and its CO2 absorption rate may be comparable to DEA with the same mass concentration.

[Study of new blended chemical absorbents to absorb CO2].

Three kinds of blended absorbents were investigated on bench-scale experimental bench according to absorption rate and regeneration grade to select a reasonable additive concentration. The results show that, among methyldiethanolamine (MDEA) and piperazine (PZ) mixtures, comparing MDEA : PZ = 1 : 0.4 (m : m) with MDEA : PZ = 1 : 0.2 (m : m), the absorption rate is increased by about 70% at 0.2 mol x mol(-1). When regeneration lasting for 40 min, regeneration grade of blended absorbents with PZ concentration of 0.2, 0.4, and 0.8 is decreased to 83.06%, 77.77% and 76.67% respectively while 91.04% for PZ concentration of 0. MDEA : PZ = 1 : 0.4(m : m) is a suitable ratio for MDEA/PZ mixtures as absorption and regeneration properties of the blended absorbents are all improved. The aqueous blends with 10% primary amines and 2% tertiary amines could keep high CO2 absorption rate, and lower regeneration energy consumption. Adding 2% 2-Amino-2-methyl-1-propanol (AMP) to 10% diethanolamine (DEA), the blended amine solvents have an advantage in absorption and regeneration properties over other DEA/AMP mixtures. Blended solvents, which consist of a mixture of primary amines with a small amount of tertiary amines, have the highest absorption rate among the three. And mixed absorbents of secondary amines and a small amount of sterically hindered amines have the best regeneration property. To combine absorption and regeneration properties, blends with medium activator addition to tertiary amines are competitive.