First-Principles Investigation of Ti2CSO and Ti2CSSe Janus MXene Structures for Li and Mg Electrodes

<div> <div> <div> <p>While lithium battery electrodes are constantly being improved in terms of their properties, discovering new materials with alternative energy carriers like Mg are important to lower the cost of production and to enhance the energy density. MXenes are a type of highly investigated materials with promising energy applications due to their excellent electronic conductivity and good mechanical and dynamical stability. Experimentally realized Janus MoSSe nanosheets provided promising results for battery electrodes. It is known that the surface terminations of MXenes highly affect on the electrochemical properties and the diffusion barriers of ions. Inspired by this, we studied Ti2CSO and Ti2CSSe Janus MXenes for Li and Mg electrodes. Our density functional theory-based, first-principles calculations indicate that both monolayers are thermodynamically, mechanically, and dynamically stable. We calculated that the average voltages for Li and Mg adsorbed Ti2CST (T = O, Se) MXenes are approximately 0.95 and 0.2 V, respectively. The maximum voltage for Ti2CSTLix is about 2 V, and that for Ti2CSTMgx is around 0.45 V. The Mg adsorbed Ti2CSO monolayer exhibits the highest gravimetric capacity (524.54 mAh/g) compared to that of other Janus MXenes considered in this paper. For Ti2CSSeLix, we obtained a higher capacity (230.45 mAh/g) and a lower diffusion barrier (0.191 eV) than that of most of the Li adsorbed S-functionalized MXenes. </p> </div> </div> </div>

First-Principles Investigation of Ti2CSO and Ti2CSSe Janus MXene Structures for Li and Mg Electrodes

<div> <div> <div> <p>While lithium battery electrodes are constantly being improved in terms of their properties, discovering new materials with alternative energy carriers like Mg are important to lower the cost of production and to enhance the energy density. MXenes are a type of highly investigated materials with promising energy applications due to their excellent electronic conductivity and good mechanical and dynamical stability. Experimentally realized Janus MoSSe nanosheets provided promising results for battery electrodes. It is known that the surface terminations of MXenes highly affect on the electrochemical properties and the diffusion barriers of ions. Inspired by this, we studied Ti2CSO and Ti2CSSe Janus MXenes for Li and Mg electrodes. Our density functional theory-based, first-principles calculations indicate that both monolayers are thermodynamically, mechanically, and dynamically stable. We calculated that the average voltages for Li and Mg adsorbed Ti2CST (T = O, Se) MXenes are approximately 0.95 and 0.2 V, respectively. The maximum voltage for Ti2CSTLix is about 2 V, and that for Ti2CSTMgx is around 0.45 V. The Mg adsorbed Ti2CSO monolayer exhibits the highest gravimetric capacity (524.54 mAh/g) compared to that of other Janus MXenes considered in this paper. For Ti2CSSeLix, we obtained a higher capacity (230.45 mAh/g) and a lower diffusion barrier (0.191 eV) than that of most of the Li adsorbed S-functionalized MXenes. </p> </div> </div> </div>

Effects of Co Addition on the Properties and Microstructure of Cu-Ni-Si-P-Mg Alloys

Cu-Ni-Si alloys are widely used in electrical and electronic industry owing to excellent electrical conductivity and strength. A suitable addition of Co in the Cu-Ni-Si alloys can improve its strength and deteriorate its electrical conductivity. In this work, Cu-Ni-Co-Si-P-Mg alloys with different Co content are employed to investigate the effects of Co on the properties and microstructure. The results showed that Co addition lead to the formation of (Ni, Co)2Si precipitates. (Ni, Co)2Si precipitate is harder to coarsen than δ-Ni2Si during aging. The larger the Co content in the alloys is, the smaller the precipitates formed is. There exists a threshold content of Co to divide the studied alloys into two groups. One group of theses alloys with <1 wt.% Co or Co/Ni ratio <0.56 has the same aging behavior as the Cu-Ni-Si-P-Mg alloy. On the contrary, the time to reach the peak hardness of aging for another group can be obviously delayed and its electrical conductivity decreases slightly with the increase of Co content. It can be attributed to the lower diffusion rate of Co than that of Ni in the Cu matrix. Meanwhile, the Co addition can inhibit the formation of P-enriched Ni-P phase in Co-containing alloys during aging. The as-quenched Cu-1.6Ni-1.2Co-0.65Si-0.1P-0.05Mg alloy can reach 257 HV and 38.7%IACS after aging at 500 °C for 3 h, respectively.

The Role of Pirfenidone in the Treatment of Interstitial Pneumonia With Autoimmune Features

Rationale: No approved pharmacotherapies are available for patients with interstitial pneumonia with autoimmune features (IPAF). Objective: In the present work, we aimed to evaluate the efficacy and safety of pirfenidone for the treatment of IPAF.Methods: A retrospective cohort study consisting of patients who met diagnostic criteria for IPAF was performed after a multidisciplinary review, and the patients receiving pirfenidone were compared with those in the non-pirfenidone group. The baseline data and diagnostic characteristics of patients were assessed. Pulmonary function and prednisone dose were analyzed by a mix-effects model.Results: A total of 184 patients, who met the diagnostic criteria of IPAF, were divided into two groups: pirfenidone group (n=81) and non-pirfenidone group (n=103). Patients in the pirfenidone group had a lower forced vital capacity (FVC%, P< 0.001) and a lower diffusion capacity for carbon monoxide (DLCO%, P=0.003). The pirfenidone group exhibited a greater increase of FVC% at 6 (P=0.003), 12 (P=0.013), and 24 (P=0.003) months. After adjustment for sex, age, UIP pattern, baseline FVC% and DLCO%, patients in the pirfenidone group continued to show a greater improvement in FVC% (χ2 (1) =4.59, P=0.032). Subgroup analysis identified superior therapeutic effects of pirfenidone in patients with dosage > 600 mg/day (P = 0.010) and medication course > 12 months (P = 0.007). Besides, the pirfenidone group had a lower prednisone dose than the non-pirfenidone group after 12 months of treatment (P=0.002). Moreover, 17 patients (19.32%) experienced side effects after taking pirfenidone, including one case of anaphylactic shock.Conclusions: Pirfenidone (600-1,800 mg/day) might help improve FVC, with an acceptable safety and tolerability profile in IPAF patients.

A Smartphone-based Diffusometric Immunoassay for Detecting C-Reactive Protein

In this study, we developed a portable smartphone-based diffusometry for analyzing the C-reactive protein (CRP) concentration. An optimized fluorescence microscopic add-on system for a smartphone was used to image the 300 nm fluorescent beads. Sequential nanobead images were recorded for a period and the image data were used for fluorescence correlation spectrometric (FCS) analysis. Through the analysis, the nanobeads’ diffusion coefficient was obtained. Further, the diffusion coefficients of the anti-CRP-coated nanobeads, which were suspended in the samples with various CRP concentrations, were estimated using smartphone-based diffusometry. After 10 min of reaction, the anti-CRP-coated nanobeads in a higher CRP concentration solution led to a lower diffusion coefficient. Based on the experiments, a linear sensing range of 1~8 µg/mL was found.

Influence of Water Concentration on Its Mobility in Matrimid®

Mobility of water in polyheteroarylene (Matrimid®) was simulated at 300 K and different concentrations of water (0.5 wt.%–3 wt.%). Parameters of anomalous diffusion were calculated from molecular dynamics simulations on the base of mean square displacements of water molecules. It was found that mobility of water has nonmonotonic dependence on its concentration. Lower diffusion rates at concentrations below than 1 wt.% can be attributed to the sorption of water onto the polar groups of polymer (sorption sites). Decreasing of diffusion rate with increasing of water concentration is due to the formation of clusters of water molecules, which hampers the penetration of water between polymer chains.

Modulating and Orienting an Anisotropic Zn-Based Metal Organic Framework for Selective CH4/CO2 Gas Separation

This work investigates the morphological control of the anisotropic [Zn2(NDC)2(DABCO)]n MOF (Metal organic framework) and the subsequent adsorption characteristics for CO2/CH4 gas separation. Morphology of the MOF crystals is controlled by the use of modulators. The addition of acetic acid or pyridine successfully produce rod or plate morphologies, respectively, with each morphology possessing a different major surface pore aperture. Single-component equilibrium and kinetic adsorption data for CO2 and CH4 were collected. Equilibrium analysis indicates a slight selectivity towards CO2 whereas kinetic data unexpectedly shows lower diffusion time constants for CO2 compared to CH4. Mass transfer resistances on each species is discussed. Finally, a coating technique termed solution shearing is used to orient different morphologies on substrates as a film. An increase in film orientation is observed for the rod morphology, indicating that this MOF morphology is a promising candidate to create large area, thin-film applications.

Fourier series solution for an anisotropic and layered configuration of the dispersive Henry Problem

Henry Problem (HP) still plays an important role in benchmarking numerical models of seawater intrusion (SWI) as well as being applied to practical and managerial purposes. The popularity of this problem is due to having a closed-form semi-analytical (SA) solution. The early SA solutions obtained for HP were limited to extensive assumptions that restrict its application in practical works. Several further studies expended the generality of the solution by assuming lower diffusion coefficients or including velocity-dependent dispersion in the results. However, all these studies are limited to homogeneous and isotropic domains. The present work made an attempt to improve the reality of the SA solution obtained for dispersive HP by considering anisotropic and stratified heterogeneous coastal aquifers. The solution is obtained by defining Fourier series for both stream function and salt concentration, applying a Galerkin treatment using the Fourier modes as trial functions and solving the flow and the salt transport equations simultaneously in the spectral space. In order to include stratified heterogeneity, a special depth-hydraulic conductivity model is applied that can be solved analytically without significant mathematical complexity. Several examples are proposed and studied. The results show excellent agreement between the SA and numerical solutions obtained with an in-house advanced finite element code.

Synthesis of Hydrophilic Polyelectrolyte as Draw Solute for Forward Osmosis Process

Synthesis and characterization of hydrophilic polyelectrolyte was performed in this work and used as draw solute for forward osmosis (FO) process. The effect of different ratios of acrylic acid (AA) and benzoyl peroxide (B) on the properties of polyelectrolyte was studied in this work. The physical and chemical properties of draw solution (DS) such as pH, conductivity, osmolality, viscosity, molecular weights and functional group were investigated. Results showed that the solution osmolality increased with increasing AA/B ratio. Self-synthesized polyelectrolytes with different molecular weights (MWs) were further correlated with its solution osmolality. The self-synthesized polyelectrolytes of PAA-K and PAA-Na showed an increasing of hydrophilic functional groups such as –OH or COOH. PAA-Na with lower MW and high osmotic pressure in the aqueous solution is found to exhibit a lower reverse solute flux during FO process. Meanwhile for the polyelectrolyte with higher MW, higher viscosity and lower diffusion coefficient were reported.

Facile Synthesis of CuO Semiconductor Nanorods for Time Dependent Study of Dye Degradation and Bioremediation Applications

The manuscript reports facile one step synthesis of CuO semiconductor nanorods by sol-gel aaproach for photocatalytic and bioremediation applications. Spectroscopic characterization along with X-ray diffractometry and electron microscopy studies confirmed the formation of nanorods with 12 to 14 nm diameter and 50-100 nm length. As synthesized nanorods were subjected to photocatalytic degradation of dyes viz. Methylene Orange (MO), Methylene Blue (MB), Eriochrome Black T (ET) and Congo Red (CR) in a time bound study. Comparative analysis of the data depicted that time taken for degradation of equal amount of CR was more compared to the other three dyes owing to its high molecular weight and lower diffusion rate in aqueous medium. Subsequently, the antibacterial properties of the nanorods were investigated against the gram negative Escherichia coli and gram positive Bacillus bacteria. Zone of clearance was observed in disk diffusion assays, thereby confirming the antibacterial characteristics of the nanorods. These nanorods thus hold great promise as a simple, selective and a sensitive analytical platform for the effective bio-monitoring and photocatalyst for dye degradation.