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The present study aims to apply an electrostatic dry powder coating process to coat aspirin tablets with polymer blends to produce a single-layer coating film, which potentially allows an advantageous delayed sustained drug release profile. The coating formulations containing polymer blends of enteric polymer (hydroxypropyl methylcellulose phthalate or hydroxypropyl methyl cellulose acetate-succinate) and insoluble polymer (Eudragit® RL) were successfully developed and optimized. Results of scanning electron microscopy and acid resistance test demonstrated that curing conditions had a significant impact on the qualities of the produced film. Drug dissolution experiments revealed that changes in the coating level and the coating formulation with different ratios of the enteric polymer to the insoluble polymer achieved an altered and adjustable drug release profile. All of the results suggested that electrostatic powder coating technology is capable to produce a satisfactory coating film with polymer blends, allowing an advantageous functionality of delayed sustained drug release.

Anion-exchange membrane electrolyzer cells (AEMECs) are one of the most promising technologies for carbon-neutral hydrogen production. Over the past few years, the performance and durability of AEMECs have substantially improved. Herein, we report an engineered liquid/gas diffusion layer (LGDL) with tunable pore morphologies that enables the high performance of AEMECs. The comparison with a commercial titanium foam in the electrolyzer indicated that the engineered LGDL with thin-flat and straight-pore structures significantly improved the interfacial contacts, mass transport, and activation of more reaction sites, leading to outstanding performance. We obtained a current density of 2.0 A/cm2 at 1.80 V with an efficiency of up to 81.9% at 60 °C under 0.1 M NaOH-fed conditions. The as-achieved high performance in this study provides insight to design advanced LGDLs for the production of low-cost and high-efficiency AEMECs.

Thin foil based porous transport layers (PTLs) that contain highly structured pore arrays have shown promise as anode PTLs in proton exchange membrane electrolysis cells. These novel PTLs, fabricated with advanced manufacturing techniques, produce thin, tunable, multifunctional layers with reduced flow and interfacial resistances and high thermal and electric conductivities. To further optimize their design, it is important to understand their fundamental impact on the transport of protons, electrons, and liquid/vapor mixtures in the electrode. In this work, we develop a two-dimensional multiphysics model to simulate the coupled electrochemistry and multiphase transport in an electrolysis cell operated with the novel PTL architecture. The results show that larger pores improve access of water to the anode catalyst layer, which is beneficial for both the oxygen evolution reaction and membrane hydration. Larger pore sizes also improve oxygen gas transport from the catalyst layer, because generated oxygen gas is forced to travel in-plane through the anode catalyst layer until it reaches a pore opening that is connected to a channel. The discussed results confirm that the proposed thin foil based PTLs are fundamentally different from conventional PTLs, such as felts or layered meshes. The model developed in this work also provides generalizable insight into fundamental PEMEC phenomena, such as the competition between liquid and gas phase transport, membrane hydration and water management, and nonuniform electrochemical reactions, which are processes relevant to all PEMEC designs.

With the progress of science and technology and the improvement of people’s living standards, the high-value utilization of waste bamboo materials and the increasingly serious problem of electromagnetic wave (EMW) pollution have attracted more and more attention. The above two problems can be solved simultaneously by overcoming the structural defects of bamboo, such as dense arrangement of fiber cells, horizontal gradient stratification and so on, realizing the impregnation of inorganic materials, and then obtaining magnetic biochar-based EMW absorbers by in situ pyrolysis. Here, we carry out fibrosis treatment to obtain bamboo bundles with significantly increased specific surface area and a large number of exposed inner walls of fiber cells. After that, the bamboo bundles are impregnated in iron acetylacetonate (Fe(acac)3) DMF solution with concentrations of 0.04, 0.08 and 0.12 g/mL, and fiberized bamboo-derived magnetic biomass carbon (FBMC) are finally prepared through in situ pyrolysis technology. The results show that the EMW absorption performance of the prepared FBMCs is best with an impregnation concentration of 0.04 g/mL, and the minimum reflection loss is − 28.21 dB at 13.40 GHz with a matching thickness of 3 mm. With further increase of the impregnation concentration, the magnetic properties and electrical conductivities of FBMCs are enhanced, but their corresponding EMW absorption performance is deteriorated. Further research shows that the absorption capacities mainly come from the good dielectric loss caused by the interfacial polarization effect, and the magnetic loss caused by natural and exchange response. It is proved that the attenuation ability of FBMC-0.04 to EMW energy mainly comes from EMW absorption behavior.

Hypersonic non-equilibrium air flows over a laminar double-cone configuration are numerically investigated. In this paper, the effects of thermochemical non-equilibrium gas, chemical non-equilibrium gas, and thermally perfect gas models on the prediction of the wall-surface heat transfer and pressure are investigated. Comparing to the high-enthalpy experimental data, the results of simulations indicate that all models have a similar tendency, and underpredict the length of the separation region, while the heat transfer peaks are overpredicted. The experimental data for surface pressure and heat transfer is insensitive to the choice of the thermally perfect gas model and non-equilibrium thermochemistry models. Quantitatively, the thermochemical non-equilibrium gas and thermally perfect gas models predict the same separation and reattachment locations within the uncertainty in the simulation, but the chemical non-equilibrium gas model predicts a smaller separation region.

Exploring cost-effective and efficient bifunctional electrocatalysts via simple fabrication strategies is strongly desired for practical water splitting. Herein, an easy and fast one-step electrodeposition process is developed to fabricate W-doped NiFe (NiFeW)-layered double hydroxides with ultrathin nanosheet features at room temperature and ambient pressure as bifunctional catalysts for water splitting. Notably, the NiFeW nanosheets require overpotentials of only 239 and 115 mV for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively, to reach a current density of 10 mA/cm2 in alkaline media. Their exceptional performance is further demonstrated in a full electrolyzer configuration with the NiFeW as both anode and cathode catalysts, which achieves a low cell voltage of 1.59 V at 10 mA/cm2, 110 mV lower than that of the commercial IrO2 (anode) and Pt (cathode) catalysts. Moreover, the NiFeW nanosheets are superior to various recently reported bifunctional electrocatalysts. Such remarkable performances mainly ascribe to W doping, which not only effectively modulates the electrocatalyst morphology but also engineers the electronic structure of NiFe hydroxides to boost charge-transfer kinetics for both the OER and HER. Hence, the ultrathin NiFeW nanosheets with an efficient fabrication strategy are promising as bifunctional electrodes for alkaline water electrolyzers.

This study investigates the influence of steel slag (SS) and steel fibers on the electrical resistivity and electromagnetic (EM) shielding effectiveness of high-strength concrete (HSC). It was found that the electrical resistivity of mixtures were mainly influenced by free water. Thus, the EM shielding effectiveness was evaluated without the effect of free water. HSC with 20% replacement ratio of SS exhibited slightly improved EM shielding, lower electrical resistivity, and reduced strength (compressive and flexural) compared to HSC without SS. However, HSC with steel fibers exhibited significantly improved EM shielding, lower electrical resistivity, and higher strength and toughness compared to HSC without steel fibers. An increase in the steel fiber content in the HSC significantly decreased the electrical resistivity and increased the shielding effectiveness, strength, and toughness. Regardless of the fiber content in the fiber volume fraction of mixture, the shielding effectiveness is similar for cases with and without SS whose electrical resistivity values differ only slightly. This proves that the EM shielding effectiveness was mainly affected by the electrical resistivity and these properties are significantly correlated when the electrical resistivity values differ noticeably. HSC reinforced with rebar with 50 mm spacing exhibited a 23.5–75.6% increase in the shielding effectiveness in the 600–1,000 MHz frequency region compared to pristine HSC.

To achieve large-scale application of proton exchange membrane electrolyzer cells (PEMECs) for hydrogen production, it is highly desirable to reduce the manufacturing cost while enhancing cell performance. In the PEMPECs, a catalyst-coated membrane (CCM) is the vital component where electrochemical reactions and mass transport mainly occur. The fabrication methods and catalyst layer (CL) structure can significantly affect the cell performance. Herein, for the first time, a comparative study of CCM fabrications with decal transfer and direct spray deposition methods have been conducted by both ex-situ materials characterization and in-situ performance testing in PEMECs. It is found CCMs that are fabricated with a direct spray deposition method display enhanced cell performance compared to CCMs fabricated with a decal transfer method, mainly due to the largely reduced ohmic resistance and improved mass transport. More importantly, cell performance can be greatly enhanced by simply regulating the Nafion ionomer content at the anode CL. The optimal Nafion ionomer content of 10 wt% gives the best cell performance at 80 °C with a low cell voltage of 1.887 V at 2 A cm−2, outperforming the commercial CCM and most other previous publications. Our study provides a valuable guidance for fabrication and optimization of CCMs with significantly enhanced performance and reduced cost for practical application of the PEMECs.

Interest in the low-cost production of clean hydrogen is growing. Anion exchange membrane water electrolyzers (AEMWEs) are considered one of the most promising sustainable hydrogen production technologies because of their ability to split water using platinum group metal-free catalysts, less expensive anode flow fields, and bipolar plates. Critical to the realization of AEMWEs is understanding the durability-limiting factors that restrict the long-term use of these devices. This article presents both durability-limiting factors and mitigation strategies for AEMWEs under three operation modes, i.e., pure water-fed (no liquid electrolyte), concentrated KOH-fed, and 1 wt% K2CO3-fed operating at a differential pressure of 100 psi. We examine extended-term behaviors of AEMWEs at the single-cell level and connect their behavior with the electrochemical, chemical, and mechanical instability of single-cell components. Finally, we discuss the pros and cons of AEMWEs under these operation modes and provide direction for long-lasting AEMWEs with highly efficient hydrogen production capabilities.

The Box–Behnken design and desirability approach were used to investigate and optimize the process parameters for aluminum reduction cells related to alumina dissolution. The bath temperature, alumina content, current and alumina temperature were chosen as the design parameters. The content of cumulative dissolved alumina (CCDA) and the relative deviation from the target content (RDTC) were adopted as the responses. The interactive influence results show that increasing the bath temperature and alumina temperature, as well as decreasing the alumina content, can increase CCDA. Increasing the bath temperature and lowering the current are beneficial for obtaining a more uniform alumina distribution. The optimal operating parameters were determined to be as follows: bath temperature of 958.8 °C, alumina content of 2.679 wt.%, current of 300 kA and alumina temperature of 200 °C.

Redox-active organic electrode materials offer several advantages over traditional inorganic compounds, such as structural and chemical tunability for multielectron reactions, high redox stability,...

As the most important part of electrochemical reaction in proton exchange membrane electrolysis cells (PEMECs) for water splitting, oxygen evolution reaction (OER) occurs at the anode catalyst layer (CL). The distribution of the OER site is affected by many factors, such as properties of CL, operation parameters, procedures, etc. To study the effects of properties of CLs on the distribution of OER site on the CL, and consequently affect the performance of PEMECs, CLs with different sheet resistances are tested under different operation conditions. The phenomena of OER on CLs are captured by a high-speed and micro-scale visualization system in-situ and analysed coupled with electrochemical results. The results show that both sheet resistance and wettability of CLs have significant impact on the distribution of the OER site, which can help optimize the design of membrane electrode assembly and improve the operating parameters for electrochemical devices.

The n-type ultrathin fully depleted silicon-on-insulator (FDSOI) metal–oxide–semiconductor field-effect transistors (MOSFETs), with a Hf0.5Zr0.5O2 high dielectric permittivity (high-k) dielectric as gate insulator, were fabricated. The total ionizing dose effects were investigated, and an X-ray radiation dose up to 1500 krad(Si) was applied for both long- and short-channel devices. The short-channel devices (0.025–0.100 μm) exhibited less irradiation sensitivity compared with the long-channel devices (0.35–16 μm), leading to a 71% reduction in the irradiation-induced drain current growth and a 26% decrease in the shift of the threshold voltage. It was experimentally demonstrated that the OFF mode is the worst case among the three working conditions (OFF, ON and All0) for short-channel devices. Also, the determined effective electron mobility was enhanced by 38% after X-ray irradiation, attributed to the different compensations for charges triggered by radiation between the high-k dielectric and buried oxide. By extracting the carrier mobility, gate length modulation, and source/drain (S/D) parasitic resistance, the degradation mechanism on X-ray irradiation was revealed. Finally, the split capacitance–voltage measurements were used to validate the analysis.

In contrast to the original form of anode, the perforated anode is a new kind of anode that can significantly reduce the bubble thickness while maintaining a stable electrolysis process. The bubble...

An experimental observation of kerosene injected into supersonic flow is presented. A reflected shock tunnel is used to produce high-temperature Mach 2 airflow. A flat plate injector model with a 0...

Supported non-precious metal nanoparticles (NPs) have attracted considerable interest for their low cost and excellent properties. However, immobilizing them with good dispersion on supports is sti...

Microwave processing techniques have been extensively used in the food industry due to its significant reduction in time and energy consumption, but its effect on the potential degradation of the extracted target compounds cannot be ignored. In this paper, experiments were carried out to establish a model system of closed magnetic stirring and controlled temperature cooling microwave irradiation (CMCC-MI system); the model extraction solutions were constructed with the standards gallic acid and resveratrol as target compounds to be extracted; its type of free radicals were detected during microwave irradiation extraction, and its changes were monitored under different microwave extraction conditions, namely, solvent types, organic extractant concentrations, microwave irradiation power, extraction temperature, and extraction time, in order to understand the effect of microwave irradiation and provide an objective evaluation polyphenols under different microwave extraction conditions. The degradation and fragment ion peaks of gallic acid and resveratrol owing to hydroxyl free radicals imply that the extraction yield should not be over-focused in actual extraction applications of microwave irradiation; more attention should be paid to the potential degradation of the extracted target compounds induced by microwave irradiation.

The microstructural, magnetic, and electrical properties of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCFO) nanofibers prepared by electrospinning and calcination were systematically investigated. It was found that the as-prepared nanofibers manifested ferromagnetism at low temperatures. Moreover, the resistance and magnetoresistance (MR) data conformed to the one-dimensional variable range hopping (1D VRH) model and revealed that LSCFO nanofibers had different electronic conduction behavior at different temperatures and magnetic fields. LSCFO nanofibers had small negative MR at low temperatures and large positive MR at high temperatures, and the transition temperature ranged between 240 and 260 K. The negative MR and the positive MR of LSCFO nanofibers manifested a fit to the 1D weak localization model and the 1D VRH model, respectively. Therefore, the proposed work can provide an important reference to the design of solid oxide fuel cells (SOFCs) based on the LSCFO cathode.

Barrier film coating is the most appropriate and widely used approach to protect solid dosages from moisture, particularly for water-sensitive drugs including herbal medicines. This study aims to produce the barrier film of a typical herbal medicine by applying an electrostatic deposition process with ultrafine powders of hydroxypropyl cellulose so as to achieve the functionality of moisture protection. The flowability of the ultrafine powders was significantly improved by adding suitable nano additives. The applied plasticizer in the coating formulation had a significant effect on the water vapor permeability of the film. Also, the electrostatic deposition efficiency were significantly affected by the charging voltage of the electrostatic gun and the plasticizer ratio. Curing time and temperature were identified as two critical parameters for barrier coating in terms of surface morphology and hygroscopicity. All the results suggested that the electrostatic deposition process is capable to produce efficient barrier film for herbal medicines.

Terahertz biosensing provides a suitable method to identify biomolecules due to their rich spectral fingerprint in this electromagnetic region. However, owing to the limitations of terahertz sources and detectors, the signal is weak and requires to be enhanced by particular technologies. In this paper, we propose a terahertz plasmonic biosensor based on Goos-Hanchen effect in graphene. Sample sensing can be realized by measuring the Goos-Hanchen shift of the reflected light. Numerical simulations show that the sensitivity of this biosensor can reach a high value up to $2.5\times 10^4\mu$ m/RIU. This graphene plasmonic configuration combined with Goos-Hanchen effect provides a novel high-sensitivity approach for future terahertz biosensing applications.

By considering a nonmonotonic d-wave superconducting (SC) gap effect in electron-doped cuprate superconductors, the energy and momentum dependence of the electronic Raman scattering is studied. The...

We investigate optical property of polarization-maintaining fiber taper (PMFT) for tunable multi-wavelength laser generation in a fiber ring cavity. A panda-type polarization fiber is fused and tapered into a fiber taper with a diameter of about 2.5 μm. Optical and thermal properties of the PMFT are investigated theoretically and experimentally. As combined with a polarization dependent isolator, tunable multi-wavelength fiber laser operation is achieved by controlling of polarization-dependent loss in the fiber ring cavity. The laser wavelength number can be switched from 1 to 4. The 3 dB bandwidths of laser spectra are less than 0.05 nm for all wavelength numbers, with a maximum OSNR of about 54 dB. For single-wavelength laser operation near 1561.66 nm, the measured wavelength and power fluctuations are

Electrostatic powder coating of osmotic pump tablets becomes increasingly attractive in pharmaceutical industry due to its dry coating process. The present study aimed to investigate the influence factors of electrostatic powder coating of osmotic pump tablets with ultrafine powders during the powder adhesion and film formation. The results of the powder adhesion evaluation indicated that the powder adhesion was significantly influenced by the liquid plasticizers and the charging voltage of the electrostatic spray gun. SEM and drug dissolution tests illustrated that coating particle size and curing time and temperature could significantly influenced the film formation process, a finer coating particle size and-/or higher curing temperature and-/or longer curing time led to a more continuous and uniform coating film. Those results indicate that a well-controlled coating film with high qualities could be fabricated by a well-designed electrostatic powder coating, suggesting it is a promising alternative for preparing osmotic drug delivery systems.

As a new generation of solid-state film cells, organic solar cells (OSCs) have become the research focus in the field of renewable energy sources, and the reported power conversion efficiencies (PCEs) have been boosted to 18%. Hole transport layer (HTL) materials, a critical component of OSCs, exert a tremendous impact on the PCE and stability of OSCs. At present, the HTL materials used in OSCs can be divided into two main categories, which are inorganic HTL materials and organic HTL materials. Although, OSCs with inorganic HTL materials can achieve satisfactory PCE, they are not suitable for large-scale commercial roll-to-roll production due to the unavoidable process of high-temperature vacuum evaporation. Recently, a great number of organic HTL materials have been designed, synthesized, and successfully applied in OSCs. Herein, we review the recent advances in organic HTL materials in single-junction OSCs and systematically discuss the relationships between the structure and properties of various HTL materials, and highlight the design rules of HTL materials for highly efficient and stable OSCs.

The goal of the study is to develop a novel method to manufacture the functional bras. The high precision three-dimensional (3D) scanner was employed to get the point cloud data. A fixed mount was invented to keep the bra cup stable and decrease measuring error. A bottom holder was prepared by the 3D printer to place the bra cup during the injection process. Furthermore, the injection points coordinate values and the injection volumes can be determined based on the 3D image of the bra cup and the thickness of those positions. At last, the three-axis automatic robot which was coupled with a precision liquid dispenser is used to inject the microcapsules solution into the bra cup for the preparation of functional intimate apparel. The proposed method was verified to be feasible and effective through a practical example.

The development of water electrolyzer is challenging as we approach theoretical limits arising from electrochemical reactions and micro-scale bubble dynamics. In this research, two-phase flow and bubble dynamics are in-situ studied in a special designed single-channel electrolyzer. The devices fabricated by a 3D printer provide a whole vision of the electrochemical reaction within the channel. In-situ observations of channel-scale hydrogen and oxygen micro-bubbles dynamics are conducted, and the whole process of hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs) are simultaneously studied. The results indicate that all bubbles generate at the interface between the proton exchange membrane and the electrode wire, and the operating conditions have a great impact on the micro bubble evolution process. The bubble detachment diameter is inversely proportional to the flow velocity, but is in direct proportion to the current density. Finally, a mathematic model has been developed, and shows a good agreement with experimental data. Those results could help to better understand the bubble evolution mechanism, in order to further understand the electrochemical reaction.

Thin/tunable liquid/gas diffusion layers (TT-LGDLs) or porous transport layers (TT-PTLs), have exhibited superior multifunctional performance in proton exchange membrane electrolyzer cells (PEMECs), which can be attributed to their unique structures, such as planar surface, straight-through pores, thin thickness, etc. For achieving better PEMEC performance, TT-LGDLs with smaller pore size are desired. However, in this case, mass diffusion issues are brought in when some of the pores are covered by the flow field lands or shoulders. The coverage of the pores can lead to very high transport resistance, which may reduce the number of active oxygen evolution reaction sites, and therefore lower down the PEMEC performance. The in-plane transport enhancement layer for TT-LGDLs/PTLs are proposed to develop a dual-layer LGDL/PTL structure for improving the mass diffusion and the PEMEC performance. The results of this research reveal that the dual-layer LGDL/PTL structure exhibits smaller ohmic resistance and mass transport resistance, and therefore improve the PEMEC performance, without obvious changes in kinetic losses. The total ohmic resistance and mass transport resistance can be reduced by about 23% and 41%, respectively, with an ∼830 μm pore TT-LGDL/PTL stacking on a ∼100 μm pore TT-LGDL/PTL. The results indicate the feasibility of stacking the in-plane transport enhancement layer with large pore sizes onto a small pore TT-LGDLs/PTLs for high efficiency and low cost PEMEC practical applications.

A stability analyser and a rheometer were used to study the effects of Tween 85 (polyoxyethylene sorbitan trioleate) on the dispersion properties of nano-aluminium/JP-10 (exo-tetrahydrodicyclopentadiene) suspensions. Results show that the addition of Tween 85 can effectively improve the stability of two-phase suspensions by hindering particle aggregation and reduce the viscosity of a system. The surface characteristics of the zeta potential and the contact angle were measured. The dispersion of the suspensions was improved by Tween 85 mainly by enhancing the steric hindrance of particles. The adsorbed particles obtained in JP-10 with different Tween 85 concentrations were analysed via scanning electron microscopy and Fourier transform infrared spectroscopy to explore the adsorption behaviour of Tween 85 molecules on the surface of aluminium particles and to confirm that Tween 85 formed an adsorption layer on the particle surface. Thermogravimetric analysis indicated that the adsorption amount of Tween 85 increased with its concentration in JP-10. The roughness analysis of the surface of adsorbed particles was measured via atomic force microscopy to characterise the thickness of the adsorption layer. The results showed that Tween 85 molecules formed an irregular adsorption layer on the particle surface, and an increase in the concentration of Tween 85 in JP-10 increased the thickness of the adsorption layer.

Wettability of titanium thin/tunable liquid/gas diffusion layers (TT-LGDLs) may affect the oxygen bubble dynamics and detachment process, and impact the performance (cell voltage) in proton exchange membrane electrolyzer cells (PEMECs). In this study, a silane monolayer is applied to tune the TT-LGDL wettability for the first time. The ultra-fast and micro-scale oxygen gas bubble dynamics and the two-phase flow in the channel are studied in situ for hydrophobically treated and hydrophilic titanium thin/tunable LGDLs (TT-LGDLs) with a high-speed and micro-scale visualization system (HMVS). The HMVS shows that the micro oxygen bubbles occur only along the CL/TT-LGDL interfaces at the rim of pores on TT-LGDLs. Bubbles more easily coalescence to form a large one in hydrophobic TT-LGDLs. Pore-scale analysis on the single bubble evolution process shows that the detachment diameter and frequency of oxygen bubbles in the hydrophobic TT-LGDLs are much larger than those in the hydrophilic TT-LGDLs. The PEMEC performance with the hydrophobic and hydrophilic TT-LGDLs are very close under 2.0 A/cm2, which means that the wettability has limited effect on TT-LGDLs mainly due to their thin features and unique structures with straight pores.

For establishing the large-scale hydrogen production as energy carrier from water electrolysis, improving cost-effectiveness and efficiency remains the main challenges. In this study, we propose a novel proton exchange membrane electrolyzer cell (PEMEC), consisting of non-conductive bipolar plates (BPs) and thin film liquid/gas diffusion layers (TF-LGDLs) to reduce the cost and improve the PEMEC performance. The 3D printed non-conductive BP is manufactured with low-cost polylactic acid (PLA) and is mainly functioned to distribute the water and gas products. A titanium thin film LGDL (TF-LGDL) with surroundings is developed for directly transporting electrons from the external power sources, which changes the electron transport path in the PEMECs. The PLA BP exhibits an extremely low cost (1/10 of that of the graphite BP), and the hydrogen production rate per unit BP cost in a PEMEC with PLA BP, is almost 6 times higher than a conventional one with graphite BPs. More importantly, the PEMECs with PLA BPs can achieve a good electrochemical performance of 2.21 V at 1 A/cm2under room temperature. A model is also developed to investigate the impact of the BP resistivity of on the cell performance, and a guideline for the selection guideline of conductivity of BPs material is provided. The easily accessible and low-cost PLA BPs coupled with the new electron-conducting path will drive the exploration of plastic materials for economic and efficient water splitting or other energy conversion devices, including fuel cells, batteries, and solar cells.

Polycrystalline Sm1−xLaxFeO3 (SLFO, x = 0, 0.05, 0.1 and 0.2) samples were prepared by solid state reaction method. The effects of La ions doping on the structure and magnetic properties of SLFO samples were studied by X-ray diffraction (XRD) and magnetic characterization (magnetic hysteresis loops and temperature-dependent magnetic susceptibility). La ions could be successfully doped into SLFO up to 20% without phase transformation. By diluting the magnetic Sm ions with this non-magnetic La ions, the magnetic anisotropy energy of SLFO increased first and then followed by dropping, so the exchange bias (EB) field also increased first and then dropped. Temperature induced spin switching can be observed after zero field cooling procedure.

Indium-doped Ga 1−x In x FeO 3 (GIFO) with x = 0–0.15 were prepared by solid state reaction. Structural, magnetic and electric properties of the samples were studied. All specimen could be well indexed by the polar Pc 21 n space group and no phase transition was observed. Saturated magnetization exhibits a maximum at light doping sample of Ga 0.95 In 0.05 FeO 3 due to the enhancement of the distortion, showing a correspondence with the variation of Fe 3+ distribution difference between two forms of sites. Pyroelectric measurements show an increase of polarization after doping. The results indicate that both magnetism and ferroelectricity of GaFeO 3 can be optimized by In doping.

Li1.2Ni1/3Co1/3Mn1/3O2 was synthesized as a cathode material for lithium-ion batteries and coated with various amounts of CoAl2O4 (0–5 wt%) at high temperature. The effect of the surface modification on the structure and electrochemical performance of the cathode was evaluated. Microstructural analysis using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy revealed that the CoAl2O4 coating did not affect the crystal structure of the electrode material and that the coating only appeared on the electrode surface. The effect of the CoAl2O4 coating on the electrochemical performance was evaluated by examining charge-discharge cycles, rate performance, and electrochemical impedance. The cathodes coated with CoAl2O4 exhibited improved discharge capacity and cyclic performance compared with those of the uncoated cathode. The electrode coated with 2.5 wt% CoAl2O4 exhibited the highest discharge capacity (202.5 mAhg−1 vs. 185 mAhg−1 for the uncoated material) and highest capacity retention (84.8% for 50 cycles vs. 78.6% for the uncoated material).

We systematically studied the structure, magnetism, resistance, magnetoresistance (MR) and nonlinear current-voltage (I-V) curves of La0.33Pr0.34Ca0.33MnO3 (LPCMO) nanofibers via electrospinning and followed calcination. Magnetic study shows that this nanosystem can form long-range order and generate spin-glass states at low temperatures. The resistance and MR studies indicate the presence of metal insulator transitions and colossal MR effects in the system, respectively. One-dimensional variable range hopping (1D VRH) model is used to explain the high-temperature segment behavior of resistance and MR. The behavior of the nonlinear I-V curves indicates the exist of threshold voltage and zero bias conductance at low temperatures in the LPCMO nanowires, which represents the existence of Coulomb gap.

Background In current clinical practice, the most commonly used fusion cage materials are titanium (Ti) alloys. However, titanium alloys are non-degradable and may cause stress shielding. ZK60 is a bio-absorbable implant that can effectively avoid long-term complications, such as stress shielding effects, implant displacement, and foreign body reactions. In this study, we aimed at investigating the biomechanical behavior of the cervical spine after implanting different interbody fusion cages.Methods The finite element (FE) models of anterior cervical disc removal and bone graft fusion (ACDF) with a ZK60 cage and a Ti cage were constructed, respectively. Simulations were performed to evaluate their properties of flexion, extension, lateral bending, and axial rotation of the cervical spine. Moreover, a side-by-side comparison was conducted on the range of motion (ROM), the deformation of cages, the stress in the cages, bone grafts, and cage-end plate interface. Simultaneously, according to the results of biomechanical analysis, the microporous structure of the ZK60 cage was improved by the lattice topology optimization technology and validation using static structure.Results The ROMs in the current study were comparable with the results reported in the literature. There was no significant difference in the deformation of the two cages under various conditions. Moreover, the maximum stress occurred at the rear of the cage in all cases. The cage's and endplate-cage interface's stress of the ZK60 group was reduced compared with the Ti cage, while the bone graft stress in the ZK60 fusion cage was significantly greater than that in the Ti fusion cage (average 27.70%). We further optimized the cage by filling with lattice structures, the volume was decreased by 40%, and validation showed more significant biomechanical properties than ZK60 and Ti cages.Conclusion The application of the ZK60 cage can significantly increase the stress stimulation to the bone graft by reducing the stress shielding effect between the two instrumented bodies. We also observed that the stress of the endplate-cage interface decreased as the reduction of the cage's stiffness, indicating that subsidence is less likely to occur in the cage with lower stiffness. Moreover, we successfully designed a porous cage on the basis of the biomechanical load by lattice optimization.

High power and frequency stability of electromagnetic wave input are required in the DNP-NMR system. It is necessary to monitor the electromagnetic wave energy in the transmission line in real-time to judge the magnitude and stability of the energy transmitted to the NMR spectrometer. However, the energy in the transmission system is too large to be directly measured in the transmission line. A part of the energy must be extracted to facilitate the measurement. We design a directional coupler by placing a wire array in the middle of the three-port circular corrugated waveguide for real-time extraction of transmitted energy. In the frequency range of 290 – 360 GHz, 0.05% energy can be stably coupled to port 3, so it is convenient for the energy detection. The S 11 parameter of the designed directional coupler can below −20dB from 290 to 360 GHz, and even −41dB at the operating frequency of 330 GHz.

Purpose: To evaluate the safety and efficacy of GreenLight XPS 180-W laser photoselective vaporization of the prostate (PVP) in high-risk elderly patients with benign prostatic hyperplasia. Materia...

This study presents the shear capacity of eco-friendly high-strength concrete (HSC) beams reinforced by 0.75% (by volume) of hooked steel fibers or shear stirrups with various spacings. Five large-scale HSC beams with steel fibers or stirrups were tested and investigated with respect to shear capacity, failure mode, and crack patterns. The test results indicate that all five tested beams finally failed by a shear-critical failure mode and that the use of 0.75 vol% of steel fibers significantly improved the shear strength although it decreased the diagonal crack angle of HSC beam in the case of without stirrups. There are some different properties compared with ACI 318-19 recommendation, but the use of 0.75 vol% steel fibers exhibited approximately 13.2% higher shear strength when compared with that of minimum shear reinforcement for the HSC beam. Furthermore, the shear capacity of steel fibers calculated by experimental data, and it was compared with several prediction equations. The prediction models containing fiber factor were more closely agreeable with test results with a minimum of 10.9% difference.

Indwelling ureteral stents represent a very frequently used procedure in urological clinical practice that ensures the drainage of urine from the upper urinary tract. However, the stents could result in many stent-associated complications, such as encrustation and patient discomfort. We developed a new type of biodegradable ureteral stents produced from degradable polyurethane and magnesium alloys. In the present study, we investigated the biocompatibility and the property of degradation of the biodegradable ureteral stents. We evaluated the cytotoxicity of biodegradable ureteral stent by the MTT assay in vitro. The rabbit dorsal muscle embedding test was used to assess the biocompatibility of the degradable stents. Inflammation and fibrosis of muscle tissue were noted to evaluate compatibility at 1, 2, 4, 6 weeks after stents implanted in muscle. The degradation of the biodegradable ureteral stents was assessed by measuring the weight loss of the samples in AUS (artificial urine solution). For validating the degradation property of degradable stents in vivo, we inserted a degradable stent or a conventional biostable stent into Bama pigs. Furthermore, blood studies, liver function tests, renal function tests, urine studies, and computerized tomography (CT) were performed postoperatively. Our study confirms that the degradable polyurethane-based biodegradable ureteral stent has good biocompatibility. Our biodegradable ureteral stents were completely degraded within 4 weeks and provided a better ability of drainage than conventional stents. They hold promise for decreasing the need for a secondary procedure and stent related morbidity, such as infections.

Oil-water two-phase flow exists widely in petroleum exploitation, storage and transportation, chemical industry, energy and other industrial fields, and water content is one of the important parameters of oil-water two-phase flow system. At present, the successful measurement of moisture content in two-phase flow is X-ray method, in which the hot cathode X-ray has a short life, a long preheating time and a large volume, which is not conducive to the measurement of two-phase flow. Compared with the existing hot cathode X ray tube, the coniferous tree carbon nanotube used in this study has a long life, short preheating time and is easy to carry. In view of the low pixel resolution of the image collected by cold cathode X-ray, median filtering, local binarization, morphological operation, small area removal and other preprocessing are carried out on the X-ray image to accurately locate the target information in the image, remove excess pixel noise, and accurately marginalize the information. Canny algorithm is used to extract the edge of X-ray pictures based on preprocessing, and a geometric model is established to calculate the moisture content. In conclusion, the two-phase flow moisture content measurement scheme based on cold cathode X-ray is completely feasible, providing an effective measurement method for the two-phase flow moisture content measurement.

In the process of oil production, to timely and accurately acquire flow pattern, velocity and the phase fraction of downhole oil-gas-water multiphase flow can better grasp the dynamic information of reservoir, which has very important significance for effectively protecting reservoir, prolonging development cycle and enhancing oil recovery of producing wells. Nuclear magnetic resonance (NMR) overcomes the technical limitations of traditional measurement methods. It has become a new research direction in the field of multiphase flow measurement, which has the advantages of wide measurable velocity range, large dynamic range of water-liquid ratio, and not affected by macro-physical characteristics such as multiphase flow pattern, velocity and viscosity. In this paper, the NMR response model of multiphase flow is constructed and the magnetization length, magnetization effect and magnetic field characteristics under different multiphase flow parameters are studied, which is used to optimize the parameters of NMR magnet. On this basis, the influence of multiphase flow parameters on NMR response signal is analyzed, and the measurement model of water holdup and velocity of multiphase flow in NMR for slug flow is constructed, which can realize on-line measurement of parameters of multiphase flow in NMR.

As a core component of the NMR two-phase flow probe, the RF coil plays an important role in signal transmission and magnetic field excitation. The traditional solenoid coil reduces the uniformity of the magnetic field due to the end effect, which affects the measurement accuracy of the resonance signal. To solve this problem, a new type of winding structure with multi-stage dense combination is proposed. In this paper, the comsol simulation tool is used to numerically simulate the distribution characteristics and matching relationship between the static magnetic field and the RF field in the detection area, and optimize the design of the coil structure parameters under the constraints of the size of the tubing. The simulation and experimental results show that the optimized coil structure has high signal-to-noise ratio, and the magnetic field is stable and uniformity within the error tolerance range within ±20 cm of the axial distance of the sensor, which effectively solves the end effect. The problem of rapid magnetic field drop has important reference value for the design of NMR two-phase flow RF probe.

In NMR multiphase flow measurement, permanent magnets are mainly used to generate a uniform static magnetic field, and the strength and uniformity of the magnetic field directly affect the final measurement results. The Halbach magnet structure is used as the main magnet for design. The advantage is that the volume is small and the magnetic field strength is large. However, the magnetic field has an end effect. The Halbach structure composed of commonly used magnets cannot meet the length requirement of the axial uniform magnetic field. Based on the theory of permanent magnet array magnetic field. The main research uses COMSOL electromagnetic simulation software to solve the problem of small effective range of axial uniform magnetic field based on the traditional Halbach cylindrical structure. Through the principle of magnetic field superposition, the design of three-section magnet structure is optimized to overcome the end effect, in order to overcome the end effect, the final designed axial uniform magnetic field range is increased by 1.5–1.67 times than the initial value, to achieve the main magnet structure for nuclear magnetic resonance detection.

Additive manufacturing (AM) of the complex devices for energy application remains an almost unexplored area, and the harsh acidic environment also limits the application of AM parts in water splitting for hydrogen production. Here, bipolar plates (BPs), which are used to transport reactants/products and conduct electrons in proton exchange membrane electrolyzer cells (PEMECs), are printed from stainless steel (SS) with selective laser melting (SLM). Then surface treatments are employed on those BPs by thin film electroplating with Au, and the protective thin layer enables the utilization of AM SS parts to both cathode and anode sides of water electrolyzer cells and exhibits superior corrosion resistances and electronic conductivities. The Au-coated AM SS BPs deliver a low interfacial contact resistance (6.4 mΩ cm2 under 1.45 MPa) and an excellent performance in PEMECs (1.71 V at 2 A/cm2), and maintain a remarkable durability in the simulated anode environment compared with the uncoated AM SS BPs and conventional graphite BPs. This approach demonstrates the possibility of 3-dimensional printing fully integrated water electrolyzer cells at both anode and cathode sides.

Proton exchange membrane electrolyzer cells (PEMECs) have been considered one of the most promising devices for hydrogen generation and energy storage from water splitting, especially when coupled with sustainable energy resources. Microporous layers (MPLs), which have been widely used in fuel cells for better catalyst access and product/reactant removal, have limited investigations in PEMECs due to harsh environments and carbon corrosion. In this study, the MPLs with both irregular micro (∼5 μm) and spherical nano (30–50 nm) titanium particles are developed on novel thin/tunable liquid/gas diffusion layers (TT-LGDLs) and are investigated comprehensively both in-situ and ex-situ for the first time. The MPLs change the wettability of the TT-LGDLs and show super hydrophobic property. The results reveal that micro particle MPLs exhibit improved catalytic activity but increased ohmic resistances, and that nano particle MPLs do not impact catalytic activity meaningfully but exhibit even greater increases in ohmic resistance. The effects of the thickness of the MPLs are also investigated and the typical MPL is also studied by in-situ visualization in a transparent PEMEC with a high-speed and micro-scale visualization system (HMVS). The results indicate the strong feasibility of the TT-LGDLs with small pore size and large porosity for high-efficiency and low-cost PEMEC practical applications.

Gas bubble dynamics and two-phase flow have a significant impact on the performance and efficiency of proton exchange membrane electrolyzer cells (PEMECs). It has been strongly desired to develop an effective experimental method for in-situ observing the high-speed/micro-scale oxygen bubble dynamics and two-phase flow in an operating PEMEC. In this study, the micro oxygen bubble dynamic behavior and two-phase flow are in-situ visualized through a high-speed camera coupled with a specific designed transparent PEMEC, which uses a novel thin liquid/gas diffusion layer (LGDL) with straight-through pores. The effects of different operating conditions on oxygen bubble dynamics, including nucleation, growth, and detachment, and two-phase flow have been comprehensively investigated. The results show that temperature and current density have great effects on bubble growth rate and reaction sites while the influence of flow rate is very limited. The number, growth rate, nucleation site, and slug flow regime of oxygen gas bubbles increase as temperature and/or current density increases, which indicates that an increase in temperature and/or current density can enhance the oxygen production efficiency. Further, a mathematical model for the bubble growth is developed to evaluate the effects of temperature and current density on the bubble dynamics. A mathematical model has been established and shows a good correlation with the experimental results. The studies on two-phase flow and high-speed micro bubble dynamics in the microchannel will help to discover the true electrochemical reaction at micro-scale in an operating PEMEC.

Lately, a great deal of attention is being paid to capsule coating, since the coat protects active pharmaceutical ingredients (APIs) from damage, as is in the case of tablet and pellet. However, moisture and heat sensitivity of gelatin shells make it challenging to coat capsules using the conventional aqueous coating techniques. In an effort to overcome this challenge, the present study aims to coat capsules using two different coating techniques: electrostatic dry powder coating (EDPC) and dip coating (DC). Both capsule coatings and free films were prepared by these two coating techniques, and the effects of coating formulations and processing conditions on the film quality were investigated. The corresponding drug in vitro release and mechanisms were characterized and compared. The results of dissolution tests demonstrated that the drug release behavior of both EDPC and DC coated capsules could be optimized to a sustained release of 24 h, following the Fick's diffusion law. The results of this study suggest that EDPC method is better than DC method for coating capsules, with respect to the higher production efficiency and better stability, indicating that this dry coating technology has promised in gelatin capsule coating applications.

Proton exchange membrane electrolyzer cells (PEMECs) have received great attention for hydrogen/oxygen production due to their high efficiencies even at low-temperature operation. Because of the high cost of noble platinum-group metal (PGM) catalysts (Ir, Ru, Pt, etc.) that are widely used in water splitting, a PEMEC with low catalyst loadings and high catalyst utilizations is strongly desired for its wide commercialization. In this study, the ultrafast and multiscale hydrogen evolution reaction (HER) phenomena in an operating PEMEC is in-situ observed for the first time. The visualization results reveal that the HER and hydrogen bubble nucleation mainly occur on catalyst layers at the rim of the pores of the thin/tunable liquid/gas diffusion layers (TT-LGDLs). This indicates that the catalyst material of the conventional catalyst-coated membrane (CCM) that is located in the middle area of the LGDL pore is underutilized/inactive. Based on this discovery, a novel thin and tunable gas diffusion electrode (GDE) with a Pt catalyst thickness of 15 nm and a total thickness of about 25 µm has been proposed and developed by taking advantage of advanced micro/nano manufacturing. The novel thin GDEs are comprehensively characterized both ex-situ and in-situ, and exhibit excellent PEMEC performance. More importantly, they achieve catalyst mass activity of up to 58 times higher than conventional CCM at 1.6 V under the operating conditions of 80 °C and 1 atm. This study demonstrates a promising concept for PEMEC electrode development, and provides a direction of future catalyst designs and fabrications for electrochemical devices.

LiNi1/3ZnxCo1/3-xMn1/3O2 (0.000 ≤ x ≤ 0.133) hollow microspheres are synthesized using MnO2 hollow microspheres both as a self-template and Mn source. These hollow microspheres, ~4 μm in diameter, are composed of approximately 300 nm basic nanoparticles. The XRD patterns of LiNi1/3ZnxCo1/3-xMn1/3O2 were analyzed by the RIETAN-FP program, and the obtained samples have a layered α-NaFeO2 structure. Electrochemical performances of the samples were carried out between 2.5 V and 4.5 V. The behavior of the lattice parameters is consistent with Cycling performance and rate performance change with increase of x. Compared with the others, the sample of x = 0.133 exhibits a relatively superior electrochemical performance. The specific capacity of x = 0.133 was increased by 10.7% than no-doped. In addition, the cyclic voltammograms curves of the second cycle show no significant alteration compared with the first cycle and the electrochemical impedance of zinc doping sample showed smaller transfer resistance than the no-doping sample.

Using additive manufacturing (AM) technology, a fundamental material and structure innovation was proposed to significantly increase the energy efficiency, and to reduce the weight, volume and component quantity of proton exchange membrane electrolyzer cells (PEMECs). Four conventional parts (liquid/gas diffusion layer, bipolar plate, gasket, and current distributor) in a PEMEC were integrated into one multifunctional AM plate without committing to tools or molds for the first time. In addition, since the interfacial contact resistances between those parts were eliminated, the comprehensive in-situ characterizations of AM cells showed that an excellent energy efficiency of up to 86.48% was achieved at 2 A/cm2 and 80 °C, and the hydrogen generation rate was increased by 61.81% compared to the conventional cell. More importantly, the highly complex inner structures of the AM integrated multifunctional plates also exhibit the potential to break limitations of conventional manufacture methods for hydrogen generation and to open a door for the development of other energy conversion devices, including fuel cells, solar cells and batteries.