Coulombic Efficiency for Practical Zinc Metal Batteries: Critical Analysis and Perspectives

Climate change and energy depletion are common worries of this century. During the global clean energy transition, aqueous zinc metal batteries (AZMBs) are expected to meet societal needs due to their large-scale energy storage capability with earth-abundant, non-flammable, and economical chemistries. However, the poor reversibility of Zn poses a severe challenge to AZMB implementation. Coulombic efficiency (CE) is a quantitative index of electrode reversibility in rechargeable batteries but is not well understood in AZMBs. Thus, in this work, the state-of-art CE to present the status quo of AZMB development is summarized. A fictional 120 Wh kg-1 AZMB pouch cell is also proposed and evaluated revealing the improvement room and technical goal of AZMB chemistry. Despite some shared mechanisms between AZMBs and lithium metal batteries, misconceptions prevalent in AZMBs are clarified. Essentially, AZMB has its own niche in the market with unique merits and demerits. By incorporating academic and industrial insights, the development pathways of AZMB are suggested. This work comprehensively explores recent advancements in the Coulombic efficiency of aqueous zinc ion batteries, illuminating overlooked test details. Setting a target of 99.9% efficiency, the researchers propose a hypothetical 120 Wh kg-1 MnO2/Zn pouch cell and delineate a three-stage plan to enhance energy density in future developments. Additionally, this work provides valuable insights for improving Coulombic efficiency and refining battery testing methodologies.imag

A Method to Upscale a Floating Offshore Wind Turbine from 5 MW to 15 MW

This thesis presents a method to upscale the NREL 5 MW reference wind turbine and the OC4 reference semisubmersible from 5 MW to 15 MW. The basis for the upscaling method is an assumption for the overturning moment scaling with turbine power rating. Focusing on the semisubmersible, this allows for upscaling by preserving max static pitch angle, or in other words, by scaling pitch restoring stiffness with the same factor as overturning moment. This was accomplished by increasing column radius, or column distance, or both. Increasing column radius increased the heave natural period and metal mass, while increasing column distance raised the center of gravity and metacentric height but slightly decreased the heave natural period, potentially exposing the platform to resonant effects. Comparison was also made to the VolturnUS-S 15 MW platform, whose design was observed to increase the heave natural period while lowering the center of gravity, addressing issues with scaling column distance. Finally, a method for estimating the upscaled platform parameters for different overturning moment assumptions was developed after observing that the upscaled platform had much greater pitch restoring stiffness than the VolturnUS-S platform. The estimation indicated that for the assumed overturning moment scaling, platform metal mass per unit power would always decrease when upscaling

Lignin-derived hard carbon anode for potassium-ion batteries : interplay among lignin molecular weight, material structures, electrolyte chemistry, and storage mechanisms

Potassium-ion battery (PIB) is a rising star in the rechargeable battery field due to its potential low cost and high energy for large-scale applications. Hard carbon (HC) is one of the most popular anodes for practical PIBs due to its high K-ion storage and relatively low material cost. Primarily, biomass (such as lignin) represents an abundant source for synthesizing HC. This thesis developed a series of HCs from lignin with different molecular weights (MWs) at serial pyrolysis temperatures (PTs) of 500–1000 °C, exhibiting varying electrochemical performance. The best lignin-derived HC (LHC) was pyrolyzed from medium-MW lignin at 700 °C (M700) and delivered a high reversible specific capacity of ~300 mAh g⁻¹ at 50 mA g⁻¹. M700 exhibited an optimal mixture of graphite-like nanocrystals with the most significant interlayer distance and amorphous structure to maximize K-ion storage from bulk insertion and surface adsorption. The role of electrolytes was then investigated to determine the LHC performance and K-ion storage mechanism. We systematically studied the influence of four electrolyte systems, i.e., two K salts (KPF⁶ and KFSI) in carbonate ester and ether solvents, on ionic mobility, cycling stability, and charge transfer kinetics of M700 in PIBs. It is found that the M700 anode achieved the best cycling stability and kinetics performance in the KFSI EC/DEC electrolyte. Mechanimsic study disclosed that the improved performance could be ascribed to the formation of robust KF-rich SEI resulting from FSI⁻ decomposition, which effectively prevented irreversible side reactions and severe structural decay (e.g., exfoliation and pulverization). The degradation mechanisms of other electrolyte systems are also explained by SEI formation and solvation/desolvation effect. It is expected that this work will provide guidance on the anode and electrolyte selection and design for PIBs in the near future.Applied Science, Faculty ofEngineering, School of (Okanagan)Graduat

Nuclear receptor RORγ inverse agonists/antagonists display tissue- and gene-context selectivity through distinct activities in altering chromatin accessibility and master regulator SREBP2 occupancy.

The nuclear receptor RORγ is a major driver of autoimmune diseases and certain types of cancer due to its aberrant function in T helper 17 (Th17) cell differentiation and tumor cholesterol metabolism, respectively. Compound screening using the classic receptor-coactivator interaction perturbation scheme led to identification of many small-molecule modulators of RORγ(t). We report here that inverse agonists/antagonists of RORγ such as VTP-43742 derivative VTP-23 and TAK828F, which can potently inhibit the inflammatory gene program in Th17 cells, unexpectedly lack high potency in inhibiting the growth of TNBC tumor cells. In contrast, antagonists such as XY018 and GSK805 that strongly suppress tumor cell growth and survival display only modest activities in reducing Th17-related cytokine expression. Unexpectedly, we found that VTP-23 significantly induces the cholesterol biosynthesis program in TNBC cells. Our further mechanistic analyses revealed that VTP-23 enhances the local chromatin accessibility, H3K27ac mark and the cholesterol master regulator SREBP2 recruitment at the RORγ binding sites, whereas XY018 exerts the opposite activities. Yet, they display similar inhibitory effects on circadian rhythm program. Similar distinctions and contrasting activities between TAK828F and SR2211 in their effects on local chromatin structure at Il17 genes were also observed. Together, our study shows for the first-time that structurally distinct RORγ antagonists possess different or even contrasting activities in tissue/cell-specific manner. Our findings also highlight that the activities at natural chromatin are key determinants of RORγ modulators' tissue selectivity

A New Species of Rhodoleia (Hamamelidaceae) From the Upper Pliocene of West Yunnan, China and Comments on Phytogeography and Insect Herbivory

In Europe, fossil fruits and seeds of Rhodoleia (Hamamelidaceae) have been described from the Upper Cretaceous to the Miocene, whereas no fossil record of Rhodoleia has been reported in Asia, where the modern species occur. Herein, 21 fossil leaves identified as Rhodoleia tengchongensis sp. nov. are described from the Upper Pliocene of Tengchong County, Yunnan Province, Southwest China. The fossils exhibit elliptic lamina with entire margins, simple brochidodromous major secondary veins, mixed percurrent intercostal tertiary veins, and looped exterior tertiaries. The leaf cuticle is characterized by pentagonal or hexagonal cells, stellate multicellular trichomes, and paracytic stomata. The combination of leaf architecture and cuticular characteristics suggests that the fossil leaves should be classified into the genus Rhodoleia. The fossil distributions indicate that the genus Rhodoleia might originate from Central Europe, and that migrated to Asia prior to the Late Pliocene. Additionally, insect damage is investigated, and different types of damage, such as hole feeding, margin feeding, surface feeding, and galling, are observed on the thirteen fossil leaves. Based on the damage frequencies for the fossil and extant leaves, the specific feeding behavior of insects on Rhodoleia trees appears to have been established as early as the Late Pliocene. The high occurrence of Rhodoleia insect herbivory may attract the insect-foraging birds, thereby increasing the probability of pollination

Impact of Gut Bacterial Metabolites on Psoriasis and Psoriatic Arthritis: Current Status and Future Perspectives.

There is growing evidence that supports a role of gut dysbiosis in the pathogenesis of psoriasis (Pso). Thus, probiotic supplementation and fecal microbiota transplantation may serve as promising preventive and therapeutic strategies for patients with Pso. One of the basic mechanisms through which the gut microbiota interacts with the host is through bacteria-derived metabolites, usually intermediate or end products produced by microbial metabolism. In this study, we provide an up-to-date review of the most recent literature on microbial-derived metabolites and highlight their roles in the immune system, with a special focus on Pso and one of its most common comorbidities, psoriatic arthritis

Optimization and evaluation of astragalus polysaccharide injectable thermoresponsive <i>in-situ</i> gels

<div><p>The objective of this study was to develop an injectable in situ forming gel system based on Poloxamer for sustained release of Astragalus polysaccharide (APS), thus achieved once or twice administration instead of frequent dosing during long-term treatment. The optimal formulation is 10 g APS, 18 g poloxamer 407, 2 g poloxamer 188, 0.15 g CMC-Na, 0.85 g sodium chloride in 100 ml gel in situ which had a preferable sol-gel transition temperature(<i>T</i> sol-gel) (34.1 ± 0.4°C), and good stability. In vitro release studies, all formulations containing polymer additives had prolonged release time and decreased initial burst to some extent. The optimal formulation containing 0.15% CMC-Na showed a best sustained release profile for about 132 h with the lowest initial burst in vitro about 16.30% in 12 h). In vivo, Male BALB/c mice (18–20 g) were administrated with APS in-situ gel just once, the values of immune organ indices, spleen lymphocyte proliferation, and serum IgM, IgG, IL-2 and IL-6 had significant increase, which was consistent with the mice given daily APS injections (7 times), while the above indices were increased more significantly in which administrated with APS in-situ gel twice. Based on these results, it can be concluded that the Poloxamer depot is a promising carrier for the sustained release of APS with an ideal release behavior.</p></div

The cellular A570 values of every group in vivo test.

<p>The cellular A570 values of every group in vivo test.</p