High Barrier Research Articles

Plastic Crystal Fast Ion‐Conductor Electrolyte Enabled Ultra‐Low Temperature Rechargeable Organic Battery

AbstractBattery performance is much damaged by ultra‐low‐temperature (<−80 °C), due to the insufficient ionic conductivity and high desolvation energy barrier. The strong coupling between ion dissociation and ion‐desolvation much increases the difficulty in electrolyte‐design. Here, it is demonstrated that such issue can be fundamentally addressed by a salt‐led electrolyte engineering. The salt with poor interionic interaction can be easily dissociated under appropriate solvation force even at extremely low‐temperature. The new electrolyte‐design logic is validated by 1‐ethyl‐1‐methylpyrrolidinium bis(fluorosulfonyl)imide, an organic ionic plastic‐crystals (OIPCs)‐characteristic salt. With the mild solvation assistance from methyl acetate, the electrolyte supplies considerable conductivity of 0.36 mS cm−1 at −110 °C and enables the smooth charging/discharging of polyimide/polytriphenylamine all‐organic cell at ultra‐low‐temperature. Even with high material loading, the cell reserves 65% of theoretical capacity under 0.2 C‐rate at −110 °C. This work represents a significant advancement in the low‐temperature batteries, and provides new knowledge of the ionic dynamics of electrolyte.

Constructing Self-Healing Polydimethylsiloxane through Molecular Structure Design and Metal Ion Bonding.

Self-healing polydimethylsiloxane (PDMS) has garnered significant attention due to its potential applications across various fields. In this study, a functionalized modification of PDMS containing di-aminos was initially conducted using 2,6-pyridinedicarbonyl chloride to synthesize pyridine-PDMS (Py-PDMS). Subsequently, rare earth metal europium ions (Eu3+) were incorporated into Py-PDMS. Due to the coordination interaction between Eu3+ and organic ligands, a coordination cross-linking network was created within the Py-PDMS matrix, resulting in the fabrication of Eu3+-Py-PDMS elastomer. At a molar ratio of Eu3+ to ligands of 1:1, the tensile strength of Eu3+-Py-PDMS reached 1.4 MPa, with a fracture elongation of 824%. Due to the dynamic reversibility of coordination bonds, Eu3+-Py-PDMS with a metal-to-ligand molar ratio of 1:2 exhibited varying self-healing efficiencies at different temperatures. Notably, after 4 h of repair at 60 °C, its self-healing efficiency reached nearly 100%. Furthermore, the gas barrier properties of Eu3+-Py-PDMS with a molar ratio of 1:1 was improved compared with that of Eu3+-Py-PDMS with a molar ratio of 1:1. This study provides an effective strategy for the design and fabrication of PDMS with high mechanical strength, high gas barrier properties, and exceptional self-healing efficiency.

New insights into hydration shells in boosting marine uranium adsorption kinetics

Identifying mass transfer is essential for boosting adsorption kinetics. The internal and external diffusions serve as rate-limiting steps. The liquid film diffusion is commonly identified as external diffusion, while the mass diffusion across the ubiquitous hydration shell is generally ignored. Charged functional groups can bind water molecules strongly via electrostatically induced hydration. Herein, three representative polar polymers, including cation polymer (PDMAPAA), anion polymer (PSS) and zwitterion polymer (PSBMA), are crosslinked with polyamioxime (PAO) to synthesize radially aligned PAO-PDMAPAA, PAO-PSS, PAO-PSBMA, respectively, by a bidirectional freeze-casting. We focus on the effect of hydration structure and hydration dynamics on marine uranium extraction performance. It is found that the external diffusion in PAO-polar polymer adsorbents can be facilitated due to fast water exchange in dynamic hydration shell, leading to a reduced adsorption equilibrium time compared with the pristine PAO. However, the high hydration degree causes strong viscous shear and high dehydration barrier, which impede the complexation of UO22+ with binding sites of PAO. Although the hydration degree follows the order of PAO-PSBMA > PAO-PDMAPAA > PAO-PSS, PAO-PDMAPAA delivers the shortest equilibrium time required. In addition, the increasing temperature would weaken viscous shear in static hydration shell, which equivalently reduces the apparent friction of hydrated uranyl ions. Consequently, light-irradiated GO@PAO-PDMAPAA adsorbent, in which GO acts as a photothermal mediator, yields a shorter equilibrium time (∼18 days) than PAO-PDMAPAA together with a high uranium adsorption capacity of 12.24 mg-U/g-Ads in natural seawater. These findings provide valuable guidance for enhancing uranium adsorption kinetics associated with hydration shell.

Efficient Modeling of Water Adsorption in MOFs Using Interpolated Transition Matrix Monte Carlo.

With the specter of accelerating climate change, securing access to potable water has become a critical global challenge. Atmospheric water harvesting (AWH) through metal-organic frameworks (MOFs) emerges as one of the promising solutions. The standard numerical methods applied for rapid and efficient screening for optimal sorbents face significant limitations in the case of water adsorption (slow convergence and inability to overcome high energy barriers). To address these challenges, we employed grand canonical transition matrix Monte Carlo (GC-TMMC) methodology and proposed an efficient interpolation scheme that significantly reduces the number of required simulations while maintaining accuracy of the results. Through the example of water adsorption in three MOFs: MOF-303, MOF-LA2-1, and NU-1000, we show that the extrapolation of the free energy landscape allows for prediction of the adsorption properties over a continuous range of pressure and temperature. This innovative and versatile method provides rich thermodynamic information, enabling rapid, large-scale computational screening of sorbents for adsorption, applicable for a variety of sorbents and gases. As the presented methodology holds strong applicative potential, we provide alongside this paper a modified version of the RASPA2 code with a ghost swap move implementation and a Python library designed to minimize the user's input for analyzing data derived from the TMMC simulations.

Tiered Licensure for Pharmacy Technicians: Is the Advanced Pharmacy Technician (APhT) License the Model for State Regulators?

Two states-Connecticut and New Hampshire-have created or attempted to create advanced pharmacy technician (APhT) licenses. Both licenses, proposed and actual, have high barriers to entry, such as requiring 1 to 3 years of prior technician experience and passage of various assessments or trainings, such as a state-specific jurisprudence exam. Those obtaining APhT licensure are granted additional authority, such as performing final product verification (e.g., tech-check-tech) and vaccine administration. Compared with practices in other states, the APhT role in CT and NH provides minimal scope gains relative to the requirements imposed; as a result, there has been limited uptake (<1%) among current technicians. As such, it appears unlikely that tiered licensure for technicians will be the preferred mechanism for states to expand the role of pharmacy technicians in the future.

The Structure-Conduct-Performance of Indonesian Coffee Processing Industry

Coffee industry in Indonesia in the short- and long terms has the potential to boost the country’s economy which can be seen in the form of structure, behavior, and performance. Market forces affect the market structure in an industry. The formation of the market structure affects a company’s behavior which further affects the performance of the company. The data used in this study is sourced from the Central Statistics Agency. The study measures the relationship of structure and other factors that affect the performance of the Indonesian coffee industry using a multiple regression model. Our findings show that the coffee processing industry in Indonesia has an oligopoly structure with a fairly high market barrier. The market behavior of the coffee processing industry is seen in terms of price strategy, products, and promotion. The performance of the coffee processing industry in Indonesia has an increasing trend every year. A positive trend results in good performance for the company so that it will increase the level of profit. Based on the regression results, the Minimum Cost Price which represents the performance of the Indonesian coffee processing industry is significantly influenced by the Efficiency Value. CR4 value and Labor Productivity have no real effect on the Minimum Price Cost. The pattern of the relationship between Efficiency and Labor Productivity to the Minimum Price Cost has a positive effect while CR4 has a negative effect. Keywords: structure, conduct, performance, coffee processing industry

Blood-brain barrier disruption and hemorrhagic transformation in acute stroke before endovascular reperfusion therapy.

Early blood-brain barrier (BBB) disruption in patients with acute ischemic stroke (AIS) can be detected on perfusion computed tomography (PCT) images before undergoing reperfusion therapy. In this study, we aimed to determine whether early disruption of the BBB predicts intracranial hemorrhage transformation (HT) in patients with AIS undergoing endovascular therapy and further identify factors influencing BBB disruption. We retrospectively analyzed general clinical and imaging data derived from 159 consecutive patients with acute anterior circulation stroke who were admitted to the Department of Neurology of the First Hospital of Jilin University, and who underwent endovascular treatment between January 1, 2021, and March 31, 2023. We evaluated the relationship between BBB destruction and intracranial HT before endovascular reperfusion therapy and examined the risk factors for early BBB destruction. A total of 159 patients with assessable BBB leakage were included. The median (interquartile range, IQR) age was 63 (54-70) years, 108 (67.9%) patients were male, and the median baseline National Institutes of Health Stroke Scale (NHISS) score was 12 (10-15). Follow-up non-contrast computed tomography (NCCT) detected HT in 63 patients. After logistic regression modeling adjustment, we found that BBB leakage in the true leakage area was slightly more than 2-fold risk of HT (odds ratio [OR], 2.01; 95% confidence interval [CI] 1.02-3.92). Heart rate was also associated with HT (OR, 1.03, 95% CI, 1.00-1.05). High Blood-brain barrier permeability (BBBP) in the true leakage area was positively correlated with infarct core volume (OR, 1.03; 95% CI, 1.01-1.05). Early BBB destruction before endovascular reperfusion therapy was associated with HT, whereas high BBBP correlated positively with infarct core volume.

Activation of σ‐Bonds by Group 13/Ylide‐Based Ambiphiles: Understanding and Design

AbstractThe factors controlling the activation of σ‐bonds promoted by hidden Frustrated Lewis Pairs have been computationally explored using quantum chemical tools. To this end, the influence of both the nature of the group 13 element acting as Lewis acid as well as the cooperative action of the Lewis antagonists on the bond activation was quantitatively analyzed by means of the activation strain model of reactivity in combination with the energy decomposition analysis method. It is found that while the activation of the polar EX−H bonds (E15=group 15 element; E16=group 16 element) is feasible, the analogous processes involving non‐polar E14−H bonds (CH4, SiH4 or H2) proceed with much higher barriers. Nevertheless, these processes, and in particular the dihydrogen activation, can be realizable (i. e. proceeding with a feasible barrier) through rational design.

Investigation of the effects of rare earth element doping on the thermophysical properties of Gd2Zr2O7 by first principles

Gd2Zr2O7 is one of the most promising new generation of ceramic materials for high temperature thermal barrier coatings. However, it still has great potential of improving thermal and mechanical properties and contributing tobetter thermal cycling performance of the coating. Doping rare earth elements in Gd2Zr2O7 is an effective method to enhance its thermal and mechanical properties. In this paper, the first principles is used to calculate the thermophysical properties of doped Gd2Zr2O7 with 16 rare earth elements, including modulus of elasticity, Debye temperature, minimum high-temperature thermal conductivity, high temperature thermal expansion coefficient, and fracture toughness, by which all doped Gd2Zr2O7 ceramics were ranked using the entropy method. The results show that doping with Pr, Sm, Yb, and Nd showed superior comprehensive performance. Specially, (Gd0.875Pr0.125)2Zr2O7 has the lowest Young's modulus of 244 MPa, Pugh ratio of 0.53, Debye temperature of 523.4 K, thermal conductivity of 1.27 W/(m·K), and the largest coefficient of thermal expansion of 9.19 × 10−6 K−1, and (Gd0.875Ho0.125)2Zr2O7 has the highest fracture toughness of 2.21 MPa·m1/2.

Integral Concurrent Learning Control Lyapunov Functions and High Order Control Barrier Functions and Application to Adaptive Cruise Control

Integral Concurrent Learning Control Lyapunov Functions and High Order Control Barrier Functions and Application to Adaptive Cruise Control

Manipulating the electronic state of ruthenium to boost highly selective electrooxidation of ethylene to ethylene glycol in acid

Electrochemical oxidation of ethylene is a novel approach to manufacture valuable ethylene glycol (EG), which is an important raw material in organic chemical industry. However, the poor EG selectivity and expensive additional purification costs hinder this method from being practically used. In this work, ultrafine iridium-ruthenium (IrRu) alloy nanoparticles are synthesized through the precipitation-reduction method and their electrocatalytic performance towards ethylene oxidation to EG has been comprehensively studied. Near 100% selectivity is achieved with a EG yield of 60.62 mmol gRu−1 h−1 at 1.475 V on an optimal Ir0.54Ru0.46 catalyst. OH-stripping, in-situ electrochemical attenuated total internal reflectance Fourier transform infrared spectra and DFT calculation reveal that the introduction of Ir can modulate the electronic structure and d-band center so as to endow the Ru with the mild binding energy with the key intermediates and small energy barrier for *HOCH2CH2OH desorption, thereby enhancing the EG generation. Simultaneously, the high energy barrier for the overoxidation of the *CH2CH2OH renders the EG formation thermodynamically favorable, thus realizing the near 100% EG selectivity. This work provides a new understanding for the high-selectivity electrosynthesis of high-value-added oxides.

Data‐efficient and risk‐based pressure sensor placement optimization for water systems

AbstractDeployment of remote metering infrastructure can help utilities improve pressure management and limit pipe break impacts. Since it is cost‐infeasible to install sensors to fully cover an entire system, a risk‐based approach where devices are deployed in areas of systemic vulnerabilities will maximize the benefit of these limited resources. Previous work on sensor allocations requires well‐calibrated hydraulic models that contain a full asset inventory. This high barrier of data requirement makes it difficult to apply existing methods. In this research, we present a more efficient methodology with lower data requirements. Proxies for system vulnerabilities are generated using historic break records, and GIS inventories are used to derive candidate installation points. The problem is presented as a generalized version of the well‐studied maximal coverage location problem, where locations are selected for optimal coverage of risky areas. The workflow is demonstrated on a small suburban utility in Pennsylvania, USA.

Factors affecting the participation and utilization of breast cancer screening services among health care workers Kolar: a qualitative study

Factors affecting the participation and utilization of breast cancer screening services among health care workers Kolar: a qualitative study

Unveiling the mechanism and selectivity of the [3 + 2] cycloaddition reactions of nitrone with acetylene derivatives leading to anticancer 4-isoxazoline derivatives from the MEDT perspective

The [3 + 2] cycloaddition reactions of N-methyl-C-(2-furyl) nitrone (a) with a series of acetylene derivatives (4b), (5b), and (6b) have been studied at the B3LYP-D3/6-31G(d) computational level within the framework of Molecular Electron Density Theory. Topological analysis allows classifying the nitrone (a) as a zwitterionic (zw-) three-atom component (TAC) associated with high energy barrier. These 32CA reactions follow a one-step mechanism under kinetic control with highly asynchronous bond formation. Bonding Evolution Theory (BET) analysis indicates that no new covalent CO and CC bonds form at the transition states (TSs). Interestingly, the global electron density transfer (GEDT) between 0.08 and 0.18 e predicts low polar character of forward electron density transfer (FEDF) type with the electronic flux from the nitrone (a) to the acetylene derivatives. Electron localization function (ELF) and atom-in-molecules (AIM) topological analysis of the electron density at the TS structures characterize the non-concerted nature of these one-step zw-type 32CA reactions.

Students Motivation Levels and Barriers to Learning Physical Education: Senior High School Perspective

This study investigated high school students motivation and barriers to implementing Physical Education (PE). This study used a descriptive quantitative research survey method involving 300 samples. The instrument utilizes an online motivation questionnaire for data collection. The data is analyzed using percentage analyses. The results of data analysis with indicators of student motivation reveal that the Intrinsic motivation and Identified regulation categories have higher results and identical values, with a value of 23%, and the Amotivation category, with a value of 15%, has lower results among other motivation indicators including intrinsic motivation, identified regulation, introjected regulation, external regulation. The indicator of student barriers shows that the external category has higher results with a value of 54%, and the internal category has lower results with a value of 46%. This research indicates that intrinsic motivation and identified regulation have identical values and are higher than the other motivation categories. It concludes that many students still have the motivation that grows from themselves and pressure from outside to participate in physical education learning. Barriers can also be concluded by examining higher external than internal indicators. This study shows that students have barriers that prevent them from growing outside to participate in educational learning activities.

Anisotropic Cu2O nanostructures: A promising remediation for per- and polyfluoroalkyl substances

Copper oxide (Cu2O) exhibits exceptional optical properties and phase stability at the nanoscale level making it highly desirable in nanotechnology applications. Its unique and distinctive properties make it highly feasible for diverse applications, which include environmental remediation, energy conversion, and catalysis. In this study, we tailor the surface and facet orientation of Cu2O nanoparticles to enhance their efficacy in addressing environmental contaminants such as per- and polyfluorinated substances (PFAS). By adjusting the ratios of the precursor and capping agent, we have synthesized Cu2O nanocubes (NCs) and octahedra (Oh) with average sizes of 450 nm and 650 nm, respectively. The time-dependent UV–Vis interaction studies revealed significant redshifts in absorption spectra upon the addition of Cu2O NCs and Oh to the PFAS solutions, indicative of the changes in the surroundings upon the interaction. FT-IR spectra further confirmed the sorption of PFAS on Cu2O nanostructures with stronger adsorption observed for longer-chain PFAS due to enhanced hydrophobic interactions. XPS analysis further provided insights into the surface composition changes after post-interaction, indicating the presence of PFAS on Cu2O nanostructures. The zeta potential analysis supported the role of electrostatic interactions in PFAS removal. Our results demonstrate that Cu2O Oh exhibits superior PFAS adsorption compared to Cu2O NCs, which is attributed to the exposed facets of a copper atom having a positive surface charge and facilitating electrostatic interactions. Specifically, Cu-terminated (110) or (111) surfaces exhibit enhanced sorption capacity, while the reduced reactivity of Cu-terminated Cu2O (100) surfaces is linked to high energy barrier holes at the surface region. Overall, this study elucidates the interaction mechanisms between Cu2O nanostructures and PFAS which underscores the significance of surface engineering for optimizing their performance in environmental remediation strategies.

Ternary Solid Polymer Electrolytes at the Electrochemical Interface: A Computational Study.

Polymer-based solid-like gel electrolytes have emerged as a promising alternative to improve battery performance. However, there is a scarcity of studies on the behavior of these media at the electrochemical interface. In this work, we report classical MD simulations of ternary polymer electrolytes composed of poly(ethylene oxide), a lithium salt [lithium bis(trifluoromethanesulfonyl)imide], and different ionic liquids [1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide] confined between two charged and uncharged graphene-like surfaces. The molecular solvation of Li+ ions and their diffusion as well as the polymer conformational picture were characterized in terms of the radial distribution functions, coordination numbers, number density profiles, orientations, displacement variance, polymer radius of gyration, and polymer end-to-end distance. Our results show that the layering behavior of the ternary electrolyte in the interfacial region leads to a decrease of Li+ mobility in the direction perpendicular to the electrodes and high energy barriers that hinder lithium cations from coming into direct contact with the graphene-like surface. The nature of the ionic liquid and its concentration were found to influence the structural and dynamic properties at the electrode/electrolyte interface, the electrolyte with low amounts of the pyrrolidinium-based ionic liquid being that with the best performance since it favors the migration of Li+ cations toward the negative electrode when compared to the imidazolium-based one.

Dynamics of carrier injection through V-defects in long wavelength GaN LEDs

The efficiency of high-power operation of multiple quantum well (QW) light emitting diodes (LEDs) to a large degree depends on the realization of uniform hole distribution between the QWs. In long wavelength InGaN/GaN QW LEDs, the thermionic interwell hole transport is hindered by high GaN barriers. However, in polar LED structures, these barriers may be circumvented by the lateral hole injection via semipolar 101¯1 QWs that form on the facets of V-defects. The efficiency of such carrier transfer depends on the transport time since transport in the semipolar QWs is competed by recombination. In this work, we study the carrier transfer from the semipolar to polar QWs by time-resolved photoluminescence in long wavelength (green to red) LEDs. We find that the carrier transfer through the semipolar QWs is fast, a few tens of picoseconds with the estimated room temperature ambipolar diffusion coefficient of ∼5.5 cm2/s. With diffusion much faster than recombination, the hole transport from the p-side of the structure to the polar QWs should proceed without a substantial loss, contributing to the high efficiency of long wavelength GaN LEDs.

Enhanced CO adsorption and *CO hydrogenation for efficient CO2 deep reduction on MnCu-NC

In CO2RR, enhancing CO adsorption could suppress desorption and increase *CO concentration for deep reduction. An underlying concern is that strong adsorption might result in high thermodynamic barrier for *CO hydrogenation, however, kinetic barrier firstly dominates the reaction pathway and determines the products selectivity. Directed by above idea, CO2RR performance on Mn, Cu doped nitrogenated carbon (MnCu-NC) is comprehensively studied using density functional theory (DFT). MnCu-NC shows a mild limiting potential of −0.59 V (*CO → *CHO) for CH3OH and CH4 products. CO poisoning is likely to cause catalyst deactivation, while CO modified MnCu-NC shows a slightly increased limiting potential of −0.63 V (*COCO → *COCHO) for CH3OH and CH4, and hydrogen evolution is significantly suppressed. Further comparative studies indicate that kinetic barrier for *CO hydrogenation is crucial for deep reduction, and C–O activation, as well as CO adsorption is enhanced by Π-backbonding. Besides, introduction Cu to dual-atom catalyst (DAC) could help retain more electrons and Mn has strong magnetization for charge transfer, both of which improve the charge densities and Π-backbonding strength, thus boosting the remarkable CO2RR performance toward CH4 and CH3OH on MnCu-NC.

Synergy of Weakly Solvated Electrolyte and LiF-Reinforced Interphase Enables Long-Term Operation of Li-Metal Batteries at Low Temperatures.

Hindered by the high diffusion energy barrier of Li+ in graphite anode layers, the low-temperature application of traditional Li-ion batteries is limited. Lithium metal without intercalation and with excellent specific capacity is expected to support battery operation at low temperatures. However, due to the low conductivity, high freezing point, and strong solvation energy of traditional carbonate electrolytes, the application of lithium-metal batteries at low temperatures remains challenged. In this paper, an all-ester-based ternary solvent electrolyte based on fluorinated carbonate and methyl acetate is developed to improve the cyclic efficiency of the Li-metal anode at subzero temperatures. Methyl acetate, with low viscosity and low freezing point, endows Li+ with efficient transfer in the bulk phase at low temperatures. Fluorinated cosolvent regulates the solvation structure, thereby facilitating Li+ desolvation while forming a LiF-rich solid electrolyte interphase. The electrolyte exhibits good compatibility with the Li-metal anode, as confirmed by the significantly reduced kinetic barrier of Li+ diffusion at the interface. The theoretical calculations suggest that anions occupy the dominant positions within the inner solvation sheath. The in situ/ex situ characterizations provide straightforward evidence of a dendrite-free Li-metal electrode during cycling. As a result, the symmetric Li||Li cell is able to cycle stably for thousands of hours at current densities of 0.5 mA cm-2 and 1 mAh cm-2. When paired with a LiFePO4 cathode, the battery at 0.2 C (1 C = 170 mA g-1) has a capacity retention of 95.4% after 200 cycles at -15 °C and 92.6% after 100 cycles at -20 °C, respectively.