We proposed a simple and high value-added technology for recycling NdFeB waste. Neodymium was successfully separated from FeNd alloy by chemical dealloying reaction FeNd + 2NdCl3 → 3NdCl2 + Fe in ...molten chlorides. In the dealloying process, the porous iron alloy with small pores (around 10 nm) and high surface area (2 ∼ 20 × 104 cm2 cm−3) was prepared. The separated neodymium can be recycled as metallic neodymium by spontaneous disproportionation 3NdCl2(l) → 2NdCl3(l) + Nd(s). In other words, the FeNd alloy only needs to be dipped in molten chloride to obtain metallic neodymium and porous iron alloy by the chemical dealloying method. And the LiCl-NdCl3 salts can be recyclable.
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•The chemical dealloying method of recycling NdFeB wastes was proposed.•The reaction process of the chemical dealloying method was revealed.•Nd was separated from FeNd alloy while porous iron alloy was prepared.
Neodymium-iron-boron (NdFeB) magnets are the rare earth products with the largest output, and their recycling is of significance for the sustainable development of rare earth resources. Currently, the recycling technology of NdFeB wastes is more concerned with the recovery of rare-earth elements, while iron is regarded as a low-value by-product. In this work, chemical dealloying method in molten chlorides was proposed to separate neodymium from FeNd alloy and simultaneously to prepare porous iron alloy. The effects of the molar ratio of reactants, dealloying temperature and time on the separation efficiency of neodymium were investigated. The maximum separation efficiency of neodymium from FeNd alloy can reach 96 %. The separation process of neodymium and the formation process of porous iron alloy were estimated based on the ICP, XRD, XPS, SEM-EDS analyses of recycled products. Neodymium was separated from FeNd alloy by the reaction with Nd(III) ions to form Nd(II) ions in molten chlorides, while the porous iron alloy was formed. The formed Nd(II) ions can be transformed into Nd(III) ions and metallic neodymium particles by the disproportionation reaction. In the process, Nd(III) ions can act as a complement to react with FeNd alloy. And neodymium was recovered in the form of metallic neodymium and NdOCl from the chloride melt and the rinsing solution of porous iron alloy, respectively. The formed porous iron alloy had the surface area of unit volume in the range of (2 ∼ 20) × 104 cm2 cm−3, the pore width around 10 nm and good hardness. The porous iron alloy is a high value-added product.
In this study, the torsional aeroelastic effects are investigated for high-rise buildings by carrying out a series of forced vibration wind tunnel tests. In these tests nine building models with ...different side ratios and structural eccentricities are considered, where the structural responses and surface pressures for each model are measured. The method used to determine the torsional aerodynamic stiffness and damping ratios from the experimental data is introduced. The effects of the vibration amplitude, side ratio, and structural eccentricities on these two ratios are examined. The results show that the amplitude of the vibration does not have a significant effect on the torsional aeroelastic effect. Also, the torsional aerodynamic stiffness ratio can be neglected in the absence of structural eccentricity. However, the side ratio has a significant effect on the aerodynamic damping ratio where it decreases with increasing side ratio. Although the cross-wind eccentricities are found to have no significant influence on the aeroelastic effects, the along-wind eccentricities greatly influence the aeroelastic effects. Furthermore, a windward eccentricity can increase both the aerodynamic stiffness and damping ratios, whereas a leeward eccentricity can decrease these ratios.
•Torsional aeroelastic effect of tall buildings is investigated using a forced vibration wind tunnel test.•Vibration magnitude has no significant effect on the torsional aeroelastic effect.•Aerodynamic damping ratio decreases with increasing side ratio.•►Along-wind eccentricities greatly affect aeroelastic effects while cross-wind eccentricities do not.•Windward eccentricity increases both aerodynamic stiffness and damping ratios.
Background—Despite global efforts to control tobacco use, smoking remains a leading cause of preventable diseases, mortality, and disparities, especially among individuals with mental health ...conditions. Smartphone apps have emerged as cost-effective tools to aid smokers in quitting; however, their evidence-based foundation remains understudied. This research conducted two searches to identify relevant apps: one through the scientific literature and the other from app stores. Methods—The study sought apps designed to assist smokers with mental health conditions in quitting. Searches were conducted in the scientific literature and major app stores. The apps found were evaluated for their basis in theory, features, and claimed effectiveness. Usage and rating scores were compared. Results—Among 23 apps found from app store search, only 10 (43%) were evidence-based and none had explicit reference to theory, while all apps identified in the literature were developed by applying theory. However, app store apps had significantly higher user numbers and ratings than those identified in the literature (mean rating 4.7 out of 5.0). Conclusion—Smokers with mental health conditions have limited support from currently available smoking cessation apps. Apps identified in the scientific literature lack sufficient use and longevity. Sustained support beyond research projects is crucial for enabling theoretically informed evidence-based apps to be available for people with mental health conditions, as is greater collaboration between developers and researchers to create apps that engage with end-user design.
A geometric analysis of the cubic A2BX6 structure commonly formed by metal halides is presented. Using the “hard-sphere” approximation, where the ions are represented by spheres of a fixed radius, we ...derive four limiting models that each constrain the distances between constituent ions in different ways. We compare the lattice parameters predicted by these four models with experimental data from the Inorganic Crystal Structure Database (ICSD). For the fluorides, the maintenance of the AX bond length at the sum of the A and X radii gives the best approximation of the lattice parameter, leading to structures with widely separated BX6 octahedra. For the heavier halides, a balance between forming an A-site cavity of the correct size and maintaining suitable anion–anion distances determines the lattice parameter. It is found that in many A2BX6 compounds of heavier halides, the neighboring octahedra show very significant anion–anion overlap. We use these models to predict a compound with A-site rattling and use density functional theory (DFT) to confirm this prediction. Finally, we use the geometric models to derive formability criteria for vacancy-ordered double perovskites.
Cisplatin is a potent antitumor drug, which is widely applied in clinical cancer treatment. However, cisplatin can hardly distinguish between healthy tissue and tumor tissue, resulting in serious ...toxic side effects. Indocyanine green (ICG) is a FDA-approved near-infrared (NIR) fluorescence dye which has been used in photothermal therapy and optically mediated diagnostic, but the application of ICG is limited by its concentration-dependent aggregation, poor aqueous stability in vitro, lack of target specificity and rapid elimination from the body. Herein, to overcome these limitations of cisplatin and ICG, we fabricated folate-modified, cisplatin, ICG-loaded lipid-polymer hybrid nanoparticles (FCINPs) using a single-step sonication method. The FCINPs exhibited well-defined monodispersity, significant stability and excellent NIR penetration ability. The intracellular uptake experiment showed that the targeting efficacy of the FCINPs was more effective in folate receptors (FRs) over-expressing MCF-7 cells than FRs negative A549 cells. In addition, compared with chemo or photothermal treatment alone, the treatment of FCINPs in combination with 808 nm NIR laser irradiation can significantly induce the apoptosis and necrosis of MCF-7 cells. These findings indicated that the FCINPs would be a promising nanosized drug formulation for tumor-targeted therapy in the future.
The near-infrared (NIR)-mediated novel strategy to control the drug release from nanocarriers has developed rapidly in recent decades. Polyaniline as a non-cytotoxic and electroactive material for ...studying cellular proliferation has attracted great attention in recent years. In the present work, polyaniline-mediated polymeric nanoparticles were developed to target the delivery of cisplatin and release it in a controllable way. The prepared polyaniline nanoparticles displayed a size of 90 ± 1.0 nm, a favorable morphology in water, and could be targeted to tumors through the high affinity between trastuzumab and the overexpressed Her2 in tumor cells. In addition, the developed nanoparticles demonstrated exciting photothermal conversion efficiency induced by NIR light and achieved significant cell inhibition efficiency (93.97%) in vitro when exposed to an 808 nm NIR laser with the power of 1.54 W for 5 min. Therefore, the developed external control release delivery system with excellent specificity and high cytotoxicity exhibited great potential in cell research and our research demonstrated that the polyaniline also has potential in the application of photothermal conversion in biomedicine.
Left bundle branch area pacing (LBBAP) has emerged as a promising physiological pacing modality. This study was designed to investigate the acute impact of the atrioventricular delay (AVD) on cardiac ...electrical characteristics and identify an optimal range of AVDs for LBBAP to achieve electrical atrioventricular and interventricular synchrony. Patients indicated for ventricular or biventricular pacing were studied during routine follow-ups at least 3 months after LBBAP implantation. Patients were excluded if they had a complete AV block or persistent atrial fibrillation. AVD was programed from 40 to 240 ms or until intrinsic conduction occurred. Optimal AVD was determined by the electrocardiography criteria, including QRS duration, reduced R-wave in lead V1, reduced notching or slurring in lateral leads, and more desirable precordial QRS transition. A total of 38 patients (age 68.7 ± 10.3 years; 16 male (42%); 18 dual-chamber pacemakers and 20 cardiac resynchronization therapy devices; average follow-up period 15.1 ± 10.2 months) were included. The fusion of LBBAP and intrinsic right ventricular conduction occurred in 21 patients with corresponding optimal AVD determined. A great proportion (∼85%) of the optimal AVDs ranged from 50% to 80% of the observed atrium-to-left bundle branch-sensing (A-LBBS) intervals. The linear correlation between the optimal AVD and corresponding A-LBBS interval (optimal AVD = 0.84 × A-LBSs interval – 36 ms) produced R = 0.86 and p <0.0001. In conclusion, AVD selection during LBBAP greatly impacted the ventricular electrical characteristics and the optimal AVD was linearly correlated with the corresponding A-LBBS interval.
•A novel HFBB analysis approach that considers the effect of higher modes has been developed.•The accuracy of the proposed method was validated for three typical lattice towers.•The proposed method ...exhibits a significant advantage for estimating wind-induced responses, especially for the TV tower.•The proposed method greatly extends the application of the HFBB technique to slender structures.
This paper presents a novel high-frequency base balance (HFBB) analysis approach that considers the effect of higher modes on wind-induced responses of tall slender structures. The generalized force for any mode is formulated by assuming a distribution of the wind force power spectral density (PSD) along the structural height, and employing the base moments measured from HFBB wind tunnel tests. The structural responses are then calculated by solving the equation of motion. The accuracy of the proposed method is validated by comparing the results from the proposed method with those from associated aeroelastic model testing, for a microwave communication tower, an electrical transmission tower and a TV tower. The results show that the proposed method exhibits a significant advantage for estimating wind-induced responses, especially for the TV tower. This is because the proposed method takes account of the contribution of the higher modes, which are usually not ignorable for tall and flexible lattice towers. Therefore, the proposed method greatly extends the application of the HFBB technique to tall and flexible structures where the effects of higher modes are significant.
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