Emerging Frontiers in Multichannel Membrane Capacitive Deionization: Recent Advances and Future Prospects.

Capacitive deionization (CDI) has emerged as a promising desalination technology and recently promoted the development of multichannel membrane capacitive deionization (MC-MCDI). In MC-MCDI, the independent control of multiflow channels, including the feed and electrolyte channels, enables the optimization of electrode operation in various modes, such as concentration gradients and reverse voltage discharge, facilitating semicontinuous operation. Moreover, the integration of redox couples into MC-MCDI has led to advancements in redox-mediated desalination. Specifically, the introduction of redox-active species helps enhance the ion removal efficiency and reduce energy consumption during desalination. This systematic approach, combining principles from CDI and electrodialysis, results in more sustainable and efficient desalination. These advancements have contributed to improved desalination performance and practical feasibility, rendering MC-MCDI an increasingly attractive option for addressing water scarcity challenges. Despite the considerable interest in and potential of this process, there is currently no comprehensive review available that covers the operational features and applications of MC-MCDI. Therefore, this Review provides an overview of recent research progress, focusing on the unique cell configuration, vital operation principles, and potential advantages over conventional CDI. Additionally, innovative applications of MC-MCDI are discussed. The Review concludes with insights into future research directions, potential opportunities in industrial desalination technology, and the fundamental and practical challenges for successful implementation.

Activity-aggression behavioural syndromes exist in males but not in females of the field cricket Teleogryllus emma.

Previous studies on sex differences in behaviour have largely focused on differences in average behaviours between sexes. However, males and females can diverge not only in average behaviours but also in the direction of behavioural correlations at the individual level (i.e. behavioural syndromes). Behavioural syndromes, with their potential to constrain the independent evolution of behaviours, may play a role in shaping sex-specific responses to selection and contributing to the development of sex differences in behaviour. Despite the pivotal role of behavioural syndromes in the evolution of sexual dimorphism in behaviour, robust empirical evidence of sex differences in behavioural syndromes based on repeated measurements of behaviours is scarce. In this study, we conducted repeated measurements of activity and aggression in male and female field crickets Teleogryllus emma, providing evidence of sex differences in the existence of behavioural syndromes. Males exhibited a significantly positive behavioural syndrome between activity and aggression, whereas females, in contrast, did not show any aggressive behaviour, resulting in the absence of such a syndrome. The sex differences in the existence of the activity-aggression behavioural syndromes in this species could be attributed to differences in selection. Selection favouring more active and aggressive males may have shaped a positive activity-aggression behavioural syndrome in males, whereas the absence of selection favouring female aggression may have resulted in the absence of aggression and the related behavioural syndrome in females. However, given the plasticity of behaviour with changes in age or the environment, further research is needed to explore how sex differences in the existence of activity-aggression behavioural syndromes change across contexts. Furthermore, understanding the genetic underpinning of sex differences in a behavioural syndrome would be pivotal to assess the role of behavioural syndromes in the evolution of sexual dimorphism in behaviours.

Hybrid Approach for Indoor Localization Using Received Signal Strength of Dual-Band Wi-Fi.

In this paper, we propose a hybrid localization algorithm to boost the accuracy of range-based localization by improving the ranging accuracy under indoor non-line-of-sight (NLOS) conditions. We replaced the ranging part of the rule-based localization method with a deep regression model that uses data-driven learning with dual-band received signal strength (RSS). The ranging error caused by the NLOS conditions was effectively reduced by using the deep regression method. As a consequence, the positioning error could be reduced under NLOS conditions. The performance of the proposed method was verified through a ray-tracing-based simulation for indoor spaces. The proposed scheme showed a reduction in the positioning error of at least 22.3% in terms of the median root mean square error compared to the existing methods. In addition, we verified that the proposed method was robust to changes in the indoor structure.

Postharvest Disease Control of Colletotrichum gloeosporioides and Penicillium expansum on Stored Apples by Gamma Irradiation Combined with Fumigation.

To study the control of postharvest decay caused by Colletotrichum gloeosporioides and Penicillium expansum, gamma irradiation alone or in combination with fumigation was evaluated to extend the shelf life of apples in South Korea. An irradiation dose of 2.0 kGy resulted in the maximum inhibition of C. gloeosporioides and P. expansum spore germination. The gamma irradiation dose required to reduce the spore germination by 90% was 0.22 and 0.35 kGy for C. gloeosporioides and P. expansum, respectively. Microscopic observations revealed that when the fungal spores were treated with gamma irradiation (4.0 kGy), conidial germination was stopped completely resulting in no germ tube formation in C. gloeosporioides. Treatment with the eco-friendly fumigant ethanedinitrile had a greater antifungal activity against C. gloeosporioides and P. expansum in comparison with the non-treated control under in vitro conditions. The in vitro antifungal effects of the gamma irradiation and fumigation treatments allowed us to further study the effects of the combined treatments to control postharvest decay on stored apples. Interestingly, when apples were treated with gamma irradiation in combined with fumigation, disease inhibition increased more at lower (< 0.4 kGy) than at higher doses of irradiation, suggesting that combined treatments reduced the necessary irradiation dose in phytosanitary irradiation processing under storage conditions.

Postharvest Control of Botrytis cinerea and Monilinia fructigena in Apples by Gamma Irradiation Combined with Fumigation.

To extend the shelf life of apples in South Korea, we evaluated the effect of gamma irradiation alone or gamma irradiation combined with fumigation on the control of postharvest decay caused by Botrytis cinerea and Monilinia fructigena. An irradiation dose of 1.0 kGy caused the maximal inhibition of B. cinerea and M. fructigena spore germination. The gamma irradiation dose required to reduce the spore germination by 90% was 0.76 and 0.78 kGy for B. cinerea and M. fructigena, respectively. Inhibition of conidial germination of both fungal pathogens occurred at a greater level at the doses of 0.2 to 1.0 kGy compared with the nontreated control; 0.2 kGy caused 90.5 and 73.9% inhibition of B. cinerea and M. fructigena, respectively. Treatment in vitro with the ecofriendly fumigant ethanedinitrile had a greater effect compared with the nontreated control. The in vitro antifungal effects of the gamma irradiation and fumigation treatments allowed us to further study the effects of the combined treatments. Interestingly, when irradiation was combined with fumigation, the percentage of disease inhibition increased more at lower (<0.4 kGy) than at higher doses of irradiation, suggesting that the combined treatments reduced the necessary irradiation dose in phytosanitary irradiation processing under storage conditions.

Membrane of Functionalized Reduced Graphene Oxide Nanoplates with Angstrom-Level Channels.

Membranes with atomic level pores or constrictions are valuable for separation and catalysis. We report a graphene-based membrane with an interlayer spacing of 3.7 angstrom (Å). When graphene oxide nanoplates are functionalized and then reduced, the laminated reduced graphene oxide (rGO) nanoplates or functionalized rGO membrane is little affected by an intercalated fluid, and the interlayer spacing of 3.7 Å increases only to 4.4 Å in wetted state, in contrast to the graphene oxide (GO) membrane whose interlayer spacing increases from 9 Å to 13 Å in wetted state. When applied to ion separation, this membrane reduced the permeation rate of small ions such as K(+) and Na(+) by three orders of magnitude compared to the GO membrane.

A carbon nanotube wall membrane for water treatment.

Various forms of carbon nanotubes have been utilized in water treatment applications. The unique characteristics of carbon nanotubes, however, have not been fully exploited for such applications. Here we exploit the characteristics and corresponding attributes of carbon nanotubes to develop a millimetre-thick ultrafiltration membrane that can provide a water permeability that approaches 30,000 l m(-2) h(-1) bar(-1), compared with the best water permeability of 2,400 l m(-2) h(-1) bar(-1) reported for carbon nanotube membranes. The developed membrane consists only of vertically aligned carbon nanotube walls that provide 6-nm-wide inner pores and 7-nm-wide outer pores that form between the walls of the carbon nanotubes when the carbon nanotube forest is densified. The experimental results reveal that the permeance increases as the pore size decreases. The carbon nanotube walls of the membrane are observed to impede bacterial adhesion and resist biofilm formation.

Carbon nanotube-bonded graphene hybrid aerogels and their application to water purification.

We present carbon nanotube (CNT)-bonded graphene hybrid aerogels that are prepared by growing CNTs on a graphene aerogel surface with nickel catalyst. The presence of bonded CNTs in the graphene aerogel results in vastly improved mechanical and electrical properties. A significant increase in specific surface area is also realized. The presence of the CNTs transforms the hybrid aerogels into a mesoporous material. The viscoelasticity of the hybrid aerogels is found to be invariant with respect to temperature over a range of between -150 °C and 450 °C. These characteristics along with the improved properties make the hybrid aerogels an entirely different class of material with applications in the fields of biotechnology and electrochemistry. The mesoporous nature of the material along with its high specific surface area also makes the hybrid aerogel attractive for application in water treatment. Both anionic and cationic dyes can be effectively removed from water by the hybrid aerogel. A number of organics and oils can be selectively separated from water by the hybrid aerogel. The hybrid aerogel is easy to handle and separate from water due to its magnetic nature, and can readily be recycled and reused.