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Turn-to-turn short circuit faults in the primary winding of generator terminal voltage transformers can lead to erroneous operation of stator grounding protection systems. This paper analyzes the fault characteristics associated with such failures and derives formulas for the fault phase current and zero-sequence voltage during a turn-to-turn short circuit in the primary winding. A 3D finite element model of the generator terminal voltage transformer is established by using Altair Flux 3D, and the accuracy of the model is verified. Based on this model, simulation tests were conducted to investigate turn-to-turn short circuits in the primary winding. The results reveal that as the number of shorted turns increases, the voltage of the fault phase decreases continuously while the voltages of the other two phases increase. The current in the short-circuited phase rises significantly, accompanied by an increase in zero-sequence voltage. Visualizations of magnetic field parameters indicate that as the number of shorted turns increases, the magnetic induction magnitude of the fault phase rises steadily and approaches saturation, resulting in heightened magnetic field intensity near the shorted turns. This analysis of fault characteristics through simulation contributes to the advancement of fault diagnosis systems for generator terminal voltage transformers. [ABSTRACT FROM AUTHOR]

To improve the adsorption efficiency of pollutants by biochar, preparing graphene-like biochar (GBC) or nitrogen-doped biochar are two commonly used methods. However, the difference in the nitrogen doping (N-doping) effects upon the adsorption of pollutants by pristine biochar (PBC) and GBC, as well as the underlying mechanisms, are still unclear. Take the tetracycline (TC) as an example, the present study analyzed the characteristics of the adsorption of TCs on biochars (PBC, GBC, N-PBC, N-GBC), and significant differences in the effects of N-doping on the adsorption of TCs by PBC and GBC were consistently observed at different solution properties. Specifically, N-doping had varied effects on the adsorption performance of PBC, whereas it uniformly improved the adsorption performance of GBC. To interpret the phenomenon, the N-doping upon the adsorption was revealed by the QSAR model, which indicated that the pore filling (VM) and the interactions between TCs with biochars (Ead-v) were found to be the most important two factors. Furthermore, the density functional theory (DFT) results demonstrated that N-doping slightly affects biochar's chemical reactivity. The van der Waals (vdWs) and electrostatic interactions are the main forces for TCs-biochars interactions. Moreover, N-doping mostly strengthened the electrostatic interactions of TCs-biochars, but the vdWs interactions of most samples remained largely unaffected. Overall, the revealed mechanism of N-doping on TCs adsorption by biochars will enhance our knowledge of antibiotic pollution remediation. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to explore hospice caregivers' downward referral decision-making experiences and barriers under the triadic linkage model in China and to analyze the deeper social dynamics of hospice referral choices., Methods: Semi-structured interviews were conducted with caregivers handling hospice referrals from two primary hospice agencies in Nanjing, China. The themes were analyzed and summarized using the Colaizzi 7-step analysis., Results: Four themes and nine subthemes were extracted: multidimensional caregiver psychological experience (Dilemma and Guilt, Emotional Support and Psychological Adaptation), perceived disparities between referral organizations (convenience and affordability in the home community, perceived lack of primary health care resources), limitations of caregiver decision-making (cognitive comprehension bias, difficulty in information seeking, and passive acceptance of decision making), and limitations of health care referral support (lack of health care referral guidance, inadequate referral handoffs)., Conclusions: Feedback from caregivers of hospice-referred patients reveals many barriers to hospice referral decision making and referral implementation. Overcoming these barriers entails efforts to change the cognitive misunderstandings regarding hospice referrals from patients' perspective, clarify the distribution of responsibilities among hospice agencies, and provide information support and decision-making assistance. These measures must be employed to improve the implementation of hospice referral, realize the multiple benefits of hierarchical diagnosis and treatment, boost patients' satisfaction with the referrals, and ensure the rational and efficient distribution of hospice resources., Competing Interests: The authors declare no conflict of interest., (© 2024 The Authors.)