Performance testing of a cross-flow membrane-based liquid desiccant dehumidification system

A membrane-based liquid desiccant dehumidification system is one of high energy efficient dehumidification approaches, which allows heat and moisture transfers between air stream and desiccant solution without carryover problem. The system performance is investigated experimentally with calcium chloride, and the impacts of main operating parameters on dehumidification effectiveness (i.e. sensible, latent and total effectiveness) are evaluated, which include dimensionless parameters (i.e. solution to air mass flow rate ratio m∗ and number of heat transfer units NTU) and solution properties (i.e. concentration Csol and inlet temperature Tsol,in). The sensible, latent and total effectiveness reach the maximum values of 0.49, 0.55, and 0.53 respectively at m∗= 3.5 and NTU = 12, and these effectiveness are not limited by m∗ and NTU when m∗ > 2 and NTU > 10. Both the latent and total effectiveness increase with Csol , while almost no variation is observed in the sensible effectiveness. All effectiveness can be improved by decreasing Tsol,in. The experimental data provide a full map of main design parameters for the membrane-based liquid desiccant air conditioning technology

Precision Measurement of M1 Optical Clock Transition in Ni12+

Highly charged ions (HCIs) have drawn significant interest in quantum metrology and in search for new physics. Among these, Ni12+ is considered as one of the most promising candidates for the next generation of HCI optical clocks, due to its two E1-forbidden transitions M1 and E2, which occur in the visible spectral range. In this work, we used the Shanghai-Wuhan Electron Beam Ion Trap to perform a high-precision measurement of the M1 transition wavelength. Our approach involved an improved calibration scheme for the spectra, utilizing auxiliary Ar+ lines for calibration and correction. Our final measured result of the M1 transition wavelength demonstrates a five-fold improvement in accuracy compared to our previous findings, reaching the sub-picometer level accuracy. In combination with our rigorous atomic-structure calculations to capture the electron correlations and relativistic effects, the quantum electrodynamic (QED) corrections were extracted. Moreover, comparing with an estimate of the one-electron QED contributions by using the GRASP2018 package, we found that the present experimental accuracy is high enough for testing the higher-order QED corrections for such a complex system with four electrons in the p subshell.Comment: 15 pages, 5 figure

Identifying Hub Genes for Heat Tolerance in Water Buffalo (Bubalus bubalis) Using Transcriptome Data

Heat stress has a detrimental effect on the physiological and production performance of buffaloes. Elucidating the underlying mechanisms of heat stress is challenging, therefore identifying candidate genes is urgent and necessary. We evaluated the response of buffaloes (n = 30) to heat stress using the physiological parameters, ELISA indexes, and hematological parameters. We then performed mRNA and microRNA (miRNA) expression profiles analysis between heat tolerant (HT, n = 4) and non-heat tolerant (NHT, n = 4) buffaloes, as well as the specific modules, significant genes, and miRNAs related to the heat tolerance identified using the weighted gene co-expression network analysis (WGCNA). The results indicated that the buffaloes in HT had a significantly lower rectal temperature (RT) and respiratory rate (RR) and displayed a higher plasma heat shock protein (HSP70 and HSP90) and cortisol (COR) levels than those of NHT buffaloes. Differentially expressed analysis revealed a total of 753 differentially expressed genes (DEGs) and 16 differentially expressed miRNAs (DEmiRNAs) were identified between HT and NHT. Using the WGCNA analysis, these DEGs assigned into 5 modules, 4 of which were significantly correlation with the heat stress indexes. Interestingly, 158 DEGs associated with heat tolerance in the turquoise module were identified, 35 of which were found within the protein-protein interaction network. Several hub genes (IL18RAP, IL6R, CCR1, PPBP, IL1B, and IL1R1) were identified that significantly enriched in the Cytokine-cytokine receptor interaction. The findings may help further elucidate the underlying mechanisms of heat tolerance in buffaloes

A rechargeable molecular solar thermal system below 0 °C

An optimal temperature is crucial for a broad range of applications, from chemical transformations, electronics, and human comfort, to energy production and our whole planet. Photochemical molecular thermal energy storage systems coupled with phase change behavior (MOST-PCMs) offer unique opportunities to capture energy and regulate temperature. Here, we demonstrate how a series of visible-light-responsive azopyrazoles couple MOST and PCMs to provide energy capture and release below 0 °C. The system is charged by blue light at -1 °C, and discharges energy in the form of heat under green light irradiation. High energy density (0.25 MJ kg-1) is realized through co-harvesting visible-light energy and thermal energy from the environment through phase transitions. Coatings on glass with photo-controlled transparency are prepared as a demonstration of thermal regulation. The temperature difference between the coatings and the ice cold surroundings is up to 22.7 °C during the discharging process. This study illustrates molecular design principles that pave the way for MOST-PCMs that can store natural sunlight energy and ambient heat over a wide temperature range.This work was supported by the National Key Research and Development Program of China (2017YFA0207500), National Natural Science Foundation of China (22022507 and 51973111), Beijing National Laboratory for Molecular Sciences (BNLMS202004), China Postdoctoral Science Foundation (2020M681279) and European Research Council (ERC) through CoG 101002131 “PHOTHERM”.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

Strawberry Nursery Plant Propagation in Relation to Soil Phosphorus and Water Variation

Strawberry nursery plants require chilling and also a high acquisition of phosphorus nutrition for helping capture and transfer energy for its rapid top growth. Soil phosphorus availability can be reduced in presence of high soil Fe, Ca and Mg concentrations in the adsorption process, which can vary with soil water content (SWC) and pH levels. A study was conducted in two commercial nursery plant production fields in the temperate Atlantic coastal areas in 2008. The objectives were to examine soil P availability, strawberry nursery plant propagation and P acquisition in relation to different soil pH, SWC and Ca, Mg and Fe concentrations. The cultivar ‘Strawberry Festival’ was used in the study and measurements were systematically taken along transects. The strawberry nursery plant propagation and productivity expressed using runners and daughter plants were significantly related to soil P availability, soil water and pH levels (0.50 < R2 < 0.61, P < 0.05). Soil soluble P concentrations were associated with soil water, pH and Ca, Mg and Fe concentrations. Strawberry produced 25 runners and 17 daughter plants in the soil with the optimal pH (6.5) and higher SWC and P availability, a 60% higher nursery productivity than that in the acidic soil (pH 5.7). Soil P concentrations were decreased while Ca, Mg and Fe cations were high in the acidic conditions. It was suggested that soil P could be fixed rapidly and thus result in low strawberry nursery productivity

Thermochemical Characterizations of Novel Vermiculite-LiCl Composite Sorbents for Low-Temperature Heat Storage

To store low-temperature heat below 100 °C, novel composite sorbents were developed by impregnating LiCl into expanded vermiculite (EVM) in this study. Five kinds of composite sorbents were prepared using different salt concentrations, and the optimal sorbent for application was selected by comparing both the sorption characteristics and energy storage density. Textural properties of composite sorbents were obtained by extreme-resolution field emission scanning electron microscopy (ER-SEM) and an automatic mercury porosimeter. After excluding two composite sorbents which would possibly exhibit solution leakage in practical thermal energy storage (TES) system, thermochemical characterizations were implemented through simulative sorption experiments at 30 °C and 60% RH. Analyses of thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) curves indicate that water uptake of EVM/LiCl composite sorbents is divided into three parts: physical adsorption of EVM, chemical adsorption of LiCl crystal, and liquid–gas absorption of LiCl solution. Energy storage potential was evaluated by theoretical calculation based on TGA/DSC curves. Overall, EVMLiCl20 was selected as the optimal composite sorbent with water uptake of 1.41 g/g, mass energy storage density of 1.21 kWh/kg, and volume energy storage density of 171.61 kWh/m3

Spatial characterization of scaled hydraulic conductivity functions in the internal drainage process leading to tropical semiarid soil management

Knowledge of water movement is critical to agricultural water use. An internal drainage experiment for assessing downward movement of soil water under the influence of gravity was conducted on a semiarid sandy soil at ICRISAT-Sadore in Niger. The objectives were to estimate unsaturated hydraulic conductivity functions K(θ) at multiple scales using soil water (θ) data determined over the drainage process, and to determine spatial characteristics of K(θ) functions for water management in the semiarid environment. The study site was a naturally rolling field and the soil was a sandy Labucheri soil series. The experimental design consisted of a nested grid with three scales, 1 × 1-m, 5 × 5-m and 20 × 20-m, using 182 neutron access tubes. Soil water movement in space was examined in the 0.15–1.50 m depth throughout the drainage course. Mean soil water downward movement varied between 0.029–1379 mm h−1, depending on water content and soil depth. Elevation features contributed to 16–40% of the variation in hydraulic conductivity functions (K(θ) = e·θf). The best fit for K(θ)-model coefficients was a normal distribution and K(θ) functions were correlated at the three scales (0.81 < R2 < 0.96, P < 0.01). The scaled K(θ) functions were auto-correlated in space within 25–60 m. Management zones based on geostatistical semivariograms and interpolated map patterns were practical for water management planning in the naturally rolling environments