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BackgroundPatients with esophageal cancer often experience clinically relevant deterioration of quality of life (QOL) after esophagectomy owing to malnutrition, lack of physical exercise, and psychological symptoms. ObjectiveThis study aimed to evaluate the feasibility, safety, and efficacy of a comprehensive intervention model using a mobile health system (CIMmH) in patients with esophageal cancer after esophagectomy. MethodsTwenty patients with esophageal cancer undergoing the modified McKeown surgical procedure were invited to join the CIMmH program with both online and offline components for 12 weeks. The participants were assessed before surgery and again at 1 and 3 months after esophagectomy. QOL, depressive symptoms, anxiety, stress, nutrition, and physical fitness were measured. ResultsOf the 20 patients, 16 (80%) completed the program. One month after esophagectomy, patients showed significant deterioration in overall QOL (P=.02), eating (P=.005), reflux (P=.04), and trouble with talking (P

Metal halide perovskite with high Young's modulus is prone to form cracks when subjected to mechanical stresses such as bending, twisting, or impacting, ultimately leading to a permanent decline in the performance of their photovoltaic devices. These mechanical properties pose challenges to the durability of long‐term service of photovoltaic devices and the production of flexible devices. To address this issue, the poly (lipoic acid‐co‐Styrene) elastomer is employed to modulate the modulus of perovskite films. The peak force quantitative nanomechanical atomic force microscopy measurements and nanoindentation tests demonstrated a reduction in modulus, with the lower modulus preventing the formation of cracks and defects during deformation. Moreover, this approach also suppressed the non‐radiative recombination of perovskite solar cells by leveraging the interaction between functional groups and defects. Through this method, the rigid inverted devices attained a power conversion efficiency of 24.42% alongside remarkable stability. Concurrently, flexible inverted devices achieved a power conversion efficiency of 22.21%. This strategy offers a promising avenue for fabricating flexible perovskite solar cells and enhancing their mechanical durability. [ABSTRACT FROM AUTHOR]

Railway vehicles are often subjected to stationary creep forces, such as those resulting from traction/braking, which can significantly affect their dynamic performance. This paper presents an analytical method to analyse the steering performance of elastically constrained wheelsets under stationary traction/braking torque. Two indices, which are independent of vehicle velocity, the 'self-steering index' and the 'lateral flexibility index', are proposed to evaluate the steering ability. The impact of traction/braking condition on the steering ability is analysed, in which the saturation characteristics of wheel-rail creep are considered. The findings confirm that stationary longitudinal creep forces, arising from traction/braking, negatively impact the steering ability of elastically constrained wheelsets. The lateral displacements are found to be larger with the same lateral external force and consequently flange contact may occur. To control the system to avoid it reaching this extreme, an optimised torque distribution strategy is proposed to minimise the impact of traction/braking on the self-steering ability. The analytical method presented in this study offers insights into the dynamics of railway vehicles under complex working conditions, facilitating further research in this field. [ABSTRACT FROM AUTHOR]

Modelling the dynamic interaction between equipment and the bogie of a railway vehicle is crucial for the vibration and fatigue analysis of equipment. Current methods such as finite element and rigid-flexible coupling techniques are cumbersome. In this study, an efficient modelling approach is proposed to obtain the dynamic properties of coupled equipment. First, the vehicle and equipment are treated as independent modules, and further coupled using the frequency response function (FRF)-based substructuring method (FBSM). The FBSM is then developed from the finite element method to derive the FRF for the force to stress of equipment. Validation against experimental data and existing methods for a metro vehicle demonstrates the efficacy of our approach. The results indicate that the proposed approach models the vehicle and equipment as independent modules, eliminating the interdependent modeling steps of the previous approach and requiring less computation. The coupled small-mass equipment has a negligible influence on the dynamic properties of the vehicle bogie, but its dynamic properties are sensitive to vehicle and connection stiffness. Moreover, the vibration fatigue of equipment caused by the wheel/rail roughness can also be analyzed with the proposed approach. [ABSTRACT FROM AUTHOR]

In this study, an analytical method based on a linear single bogie model was used to investigate the mechanism of active steering for three control structures: wheelset yaw control (WYC), wheelset lateral control (WLC), and bogie yaw control (BYC). The results revealed that the WYC structure reduced both circumferential and axial wear, whereas the WLC and BYC structures mainly reduced circumferential wear, and BYC was ineffective when the primary lateral stiffness was low. Moreover, the impact of external forces on the control quantity was investigated by using a nonlinear full-vehicle model, with the wheelset unbalanced moment having the largest impact. Subsequently, the adaptation of the WYC and BYC structures to two control modes, namely, force and displacement control, was analysed. The results showed that for the WYC, the displacement control mode was favoured, whereas for the BYC, the force control mode was the sole alternative. Finally, the control efficiency was determined, with the WYC being recommended for low primary longitudinal stiffness and BYC for higher stiffness. [ABSTRACT FROM AUTHOR]

Severe wheel polygon will cause the strong repeated wheel-rail excitation, accelerating the failure of vehicle key components. Nevertheless, the traditional spectral estimation methods are not ideal for dealing with these wheel fault signals, making the characteristic frequencies caused by wheel polygon hardly detected. This paper proposes a dynamic detection method for wheel polygon based on parametric power spectral estimation for the first time. Firstly, according to the dynamic characteristics of the wheel polygon, the harmonic frequency recovery model is established. Secondly, the order of the harmonic frequency recovery model is determined based on singular value decomposition and normalised error analysis. Then, the total least square method is used to calculate the parameters of the harmonic recovery model. Finally, the power spectrum of the fault signal is evaluated according to the Cadzow estimation theory. The simulation signal and the measured axle-box vertical vibration acceleration signal of a metro vehicle are taken as case studies to verify the feasibility and effectiveness of the proposed method thoroughly. The results show the proposed method can avoid the inherent defects of traditional detection and analysis methods, weaken the influence of background noise, and is highly advantageous in detecting the initial stage of wheel polygonal wear. [ABSTRACT FROM AUTHOR]

Polygonal wear of railway wheels will accelerate the failure of critical structure. It is of great significance to monitor their state in service. However, affected by the frequently changed operating speed and track irregularity, the operation process of the vehicle is typically non-stationary. The traditional analyzing methods are not ideal for dealing with the non-stationary processes, causing the accurate detection of wheel polygon wear state very hard. This paper proposes a dynamic detection framework based on iterative modified discrete Fourier transform to solve the above problem. Firstly, extract the relatively stationary short-time signals from the original signal by setting appropriate stationarity test conditions. Secondly, obtain the wheel polygon's vibration frequency and period by taking the iterative calculation and analysis. Thirdly, truncate the extracted short-time signal again to get a new short- time signal representing an integer multiple of the wheel polygon's vibration period. Finally, combined with the wheel polygon's dynamic characteristics, take the frequency domain analysis to the new short-time signal and realize the accurate estimation of the wheel polygon wear state. The simulation and experiment results show that the detection framework can effectively eliminate the influence of non-stationary factors and better solve the inherent defects of traditional analysis methods. [ABSTRACT FROM AUTHOR]