The use of zinc and its alloys in rechargeable aqueous batteries faces a major problem: corrosion. This must be overcome to ensure the delivery of the sustainable hybrid rechargeable aqueous battery ...system. In this review, the mechanism of zinc corrosion in acidic aqueous electrolytes has been discussed, followed by a summary of corrosion studying methods. The use of polymer-containing materials to protect zinc from corrosion and their possible applications in batteries are also discussed.
The chemistry, methods, and results of corrosion studies on zinc coating using polymer-containing materials may be exploited in the development of the next generations of hybrid rechargeable aqueous batteries.
Intergroup conflict is a costly and persistent aspect of social life, and one that often carries great moral significance for those who participate in it. Ostensibly moral behaviors can provide a ...path to social status in groups, as when self-sacrificing in-group members gain respect and prestige relative to their peers. This article bridges these two ideas to examine the perceived morality and status worthiness of intergroup revenge and forgiveness, and the moral accounts used to justify them. Using an original survey experiment conducted on a national probability sample in the United States, we examine everyday intergroup conflicts across national, sports, and political identities. We find forgiveness is perceived as more moral, and in turn more status worthy, than revenge. Justifications for moral judgments typically drew on accounts of harm/care, reciprocity, and avoiding chaos and disorder. This contributes to research on conflict, group dynamics, status, and morality.
Single phase cubic spinel LiMn2O4 nanosized particles are synthesized by a novel solution-mediated solid state method. The obtained LiMn2O4 nanoparticles have a narrow particle size distribution in a ...range from 100 to 300nm. Cyclic voltammetry and galvanostatic charge–discharge tests of the LiMn2O4 samples are performed in an aqueous solution of lithium and zinc acetates, using zinc as anode. Cells containing nanosized LiMn2O4 cathodes have higher specific discharge capacity, coulombic efficiency, better cyclability and rate capability than the cells containing conventional bulk LiMn2O4. The superior electrochemical performance can be ascribed to the much smaller particle size and less agglomeration, which not only shorten the diffusion pathway for electrons and lithium ions but also provide a larger specific surface area for lithium transportation during high C-rate charge–discharge cycling.
•Single phase cubic spinel LiMn2O4 nanosized particles are synthesized by a solution-mediated solid state method.•The obtained LiMn2O4 nanoparticles have a narrow particle size distribution in a range from 100 to 300nm.•The nanosized LiMn2O4 cathode shows superior electrochemical performance in comparison with conventional bulk LiMnO4 cathode in the rechargeable hybrid aqueous batteries
Fractional exhaled nitric oxide (FENO) is a biomarker of airway inflammation in asthma. The measurement of FENO is utilized to assist in the diagnosis and treatment of children with asthma, ...especially for those treated with inhaled corticosteroids.
The aims of this study were to evaluate the correlations between FENO and atopic status, blood eosinophil levels, FCER2 mutation, and asthma control in Vietnamese children.
This was a prospective and descriptive study approved by the local Ethical Board. All children with uncontrolled asthma, seen in the National Hospital of Pediatrics (Hanoi, Vietnam), were included. Exhaled breath FENO, blood eosinophils, skin prick test, total IgE, asthma control test (ACT), and FCER2 gene polymorphism were performed at inclusion. They were followed up at 3 months to evaluate clinical status, FENO levels, and ACT.
Forty-two children with uncontrolled asthma with a mean age of 10±3 years (6-16 years) were included. The male/female ratio was 2.5/1. The mean FENO levels were 26±25 ppb. FENO was significantly higher in patients with a positive skin prick test for respiratory allergens (
<0.05). FENO was significantly correlated with blood eosinophil levels (
=0.5217;
=0.0004). Five of the 32 subjects (15.6%) had a mutation of FCER2 gene (rs28364072 SNP). In this group, the levels of FENO were highest (37±10 ppb;
<0.05). The levels of FENO were significantly decreased after 3 months of treatment (17±8 ppb vs 26±25 ppb;
<0.05). Significant correlations between inhaled corticosteroid doses and FENO levels occurred at 1 and 3 months (
=0.415,
=0.007;
=0.396,
=0.010; respectively). There were no correlations between FENO levels, ACT, and daily use of salbutamol. After 3 months, asthma remained uncontrolled in 22.2% of children.
The measurement of FENO levels is a useful and feasible tool to predict clinical, biological, and asthma control in Vietnamese children.
Ultrathin microporous carbon (UMPC) for lithium–sulfur (Li–S) cathode with uniform pore width of approximately 0.6 nm and dozens nm in thickness is synthesized with graphene oxide as template by ...glucose hydrothermal carbonization and surfactant-assisted assembling method. The UMPC supplies desirable S pregnancy space and the intimate contact between UMPC and S, therefore improving the conductivity of S@UMPC composite and dynamic performance. Smaller sulfur molecules limited in UMPC thoroughly prevent the formation of electrolyte-soluble polysulfides, hence excellent cycling performance with 900 mAh g−1 after 150 cycles is kept. Ultrathin three-dimensional carbon nanosheets are significant to fast electron transfer and Li+ diffusion contributing to excellent dynamic performance (710 mAh g−1 at 3 C).
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•UMPC synthesized with graphene as template by glucose hydrothermal carbonized self-assemble.•Stable smaller sulfur molecules were implanted in ultrathin-microporous carbon.•UMPC with excellent conductivity improves the C-rate performance of S@UMPC.•900 mAh g−1 is kept after 150 cycles charge/discharge process at 0.1 C.
A novel self-assembled LiFePO4/graphene composite is successfully prepared by a facile template-free hydrothermal approach. Physical and electrochemical properties of the LiFePO4/graphene composite ...as cathode material in rechargeable hybrid aqueous batteries are firstly investigated. The LiFePO4/graphene composite exhibits a high discharge capacity of 145.8mAhg−1 at 0.2C, which is 40% higher than that of pristine LiFePO4. Moreover, LiFePO4/graphene shows much better rate capability and excellent cyclability. This enhanced electrochemical performance could be attributed to the positive effects of graphene nanosheets, which create a flexible electrical conductive matrix, ensuring a continuous electron pathway in bulk electrode and absorbing the volume change during lithium intercalation/de-intercalation of LiFePO4.
•A self-assembled LiFePO4/graphene composite is prepared by a hydrothermal method.•The LiFePO4 particles with rough surface are composed of numerous nanoparticles.•LiFePO4 particles are distributed uniformly among the wrinkled graphene sheets.•LiFePO4/graphene shows superior properties in rechargeable hybrid aqueous battery.
Detecting contact when fingers are approaching an object and estimating the magnitude of the force the fingers are exerting on the object after contact are important tasks for a multi-fingered ...robotic hand to stably grasp objects. However, for a linkage-based under-actuated robotic hand with a self-locking mechanism to realize stable grasping without using external sensors, such tasks are difficult to perform when only analyzing the robot model or only applying data-driven methods. Therefore, in this paper, a hybrid of previous approaches is used to find a solution for realizing stable grasping with an under-actuated hand. First, data from the internal sensors of a robotic hand are collected during its operation. Subsequently, using the robot model to analyze the collected data, the differences between the model and real data are explained. From the analysis, novel data-driven-based algorithms, which can overcome noted challenges to detect contact between a fingertip and the object and estimate the fingertip forces in real-time, are introduced. The proposed methods are finally used in a stable grasp controller to control a triple-fingered under-actuated robotic hand to perform stable grasping. The results of the experiments are analyzed to show that the proposed algorithms work well for this task and can be further developed to be used for other future dexterous manipulation tasks.
The all-vanadium redox flow battery (VRFB) is one of the most promising energy storage systems to be associated with the grid. The system has been developed for almost 30 years. A key component for ...VRFBs is the membrane separator, which separates the positive and negative half-cells and prevents the cross-mixing of vanadium ions, while providing required ionic conductivity. In general, research is conducted to solve a multi-variable problem which requires optimization in both physical characteristics and electrochemical performance of the membrane. Nafion and its derivatives are still important materials thanks to their high chemical stability and ionic conductivity. However, weaknesses of these materials, such as high vanadium ion crossover and high cost, stimulate new approaches in materials design for VRFBs. New achievements in material sciences and polymer chemistry allow further development of other types of polymeric materials and composites as separators in VRFBs. This includes new cation exchange membranes, anion exchange membranes, amphoteric ion-exchange membranes, and non-ionic porous materials. Each type of material exhibits its advantages, accompanied by its weaknesses. Recent articles in polymer-containing membranes for use as separators in VRFBs are reviewed.
A key component for all-vanadium redox flow batteries is the membrane separator, which separates the positive and negative half-cells and prevents the cross-mixing of vanadium ions, while providing required ionic conductivity.
A composite consisting of sulfur/dehydrogenated polyacrylonitrile is one of the most promising cathode materials for use in rechargeable lithium–sulfur batteries. However, the reported sulfur ...contents have been low, less than 50 wt%, which compromise the intrinsic high specific capacity and energy of elemental sulfur and hence decrease significantly the specific energy of the composite. To identify the potential to further increase the sulfur content, we elucidate the binding mechanism of sulfur and polyacrylonitrile in their composite. The heat treatment experiments at varying timespans with excess sulfur showed a constancy of sulfur content after a critical length of timespan, indicating the saturation of sulfur in the structure of dehydrogenated polyacrylonitrile. Based on molecular structure and size consideration, it is proposed that the binding involves the formation of an 8 membered ring of sulfur embedded between 4 heterocyclic rings of dehydrogenated polyacrylonitrile. From this model and experimental results, we show that there exists an upper limit of sulfur content in the sulfur/dehydrogenated polyacrylonitrile composite at 56 wt%.
•Binding mechanism of sulfur and dehydrogenated polyacrylonitrile is proposed.•C/H molar ratio is about 6 in the thermally stable structure.•The upper limit for sulfur content in the composite is 56 wt%.•Higher sulfur content will result in poor electrochemical performance.
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