Search Results (127)

This work presents a micromagnetic investigation of monolayer L1₀ FePt and FePt/Fe bilayer thin films to clarify the role of thickness, composition, and exchange coupling in their magnetic behavior. Simulations were performed using the Landau–Lifshitz–Gilbert formalism implemented in OOMMF, with realistic material parameters and geometries. For FePt monolayers, film thicknesses of 1–20 nm were examined, revealing a non-monotonic coercivity trend: the coercive field increased from 35 mT at 1 nm to 136 mT at 10 nm and decreased to 69 mT at 20 nm. This evolution indicates a transition from localized reversal to domain-wall-mediated switching once the film exceeds the exchange length (10–20 nm). Additional simulations varying Fe concentration (48–68%) through the exchange stiffness constant showed that higher Fe content strengthens magnetic coupling and increases coercivity. Bilayer systems combining a 2 nm FePt layer with Fe layers of 10 and 12 nm exhibited rectangular, saturated loops, confirming strong exchange coupling and exchange-spring behavior. The results identify 2 nm FePt as the optimal thickness for achieving full saturation, balanced coercivity, and thermal stability in FePt/Fe thin-film architectures. Full article

Grain oriented electrical steel is the most common core material used in power and distribution transformers. Compressive mechanical stress has a detrimental effect on the magnetic properties of the steel; thus, it is important to develop techniques and models that might be useful for the designers of magnetic circuits in non-rotating electrical machines. The present paper proposes an approach to address this issue. The approach is related to previous research by Garikepati et al., yet it uses more easily accessible measurement data (coercive field strength). The phenomenological T(x) model is used as part of the computational chain. The results might interest engineers working on the nondestructive testing of soft magnetic materials. Full article

Residual stress plays a critical role in the durability and structural integrity of steel rolls and bars. Proper analysis helps prevent defects like warping or cracking, ensuring the steel meets quality standards and performs reliably in critical applications. This paper presents a methodology for analysing residual stresses using electromagnetic acoustic transducer (EMAT) based nonlinear ultrasonics. It compares its effectiveness with established techniques such as X-ray diffraction (XRD) and coercive force measurements. The results demonstrate that nonlinear ultrasonics provides more detailed insights into stress distribution, particularly in subsurface regions where traditional methods like XRD face limitations. It also shows good sensitivity to stress-induced microstructural variations than coercive force measurements. This research study is the first to perform a comparative analysis using XRD, EMAT, and coercive force techniques on industrial samples, followed by the implementation of EMAT nonlinear technology at an industrial production site. The findings indicate a positive trend observed in XRD and coercive force results, and those from nonlinear ultrasonics, further validating its accuracy. Moreover, the technology has been successfully applied in steel manufacturing industries through the project named STEEL components assessment using a novel non-destructive residual stress ultrasonic technology (STEELAR), funded by the Research Fund for Coal and Steel (RFCS). These findings underscore the potential of nonlinear ultrasonics as a powerful, fast and complementary tool for comprehensive residual stress monitoring in steel components, enhancing both theoretical understanding and practical industrial application. Full article

This study introduces a theoretical and computational framework for modeling acoustic wave propagation in defective concrete, with applications to non-destructive testing and structural health monitoring. The formulation is based on a coupled system of evolutionary hyperbolic equations, where internal defects are explicitly represented as localized energetic sources or sinks. A key contribution is the definition of a coercivity coefficient, which quantifies the energetic effect of defects and enables their classification as stabilizing, neutral, or dissipative. The model establishes a rigorous relationship between defect morphology, spatial distribution, and the global energetic stability of the material. Numerical simulations performed with an explicit finite-difference time-domain scheme confirm the theoretical predictions: the normalized total energy remains above $95\%$ for stabilizing defects (${\mu }_i>0$), decreases by about $10\%$ for quasi-neutral cases (${\mu }_i\approx 0$), and drops below $50\%$ within $200\mathsf{\mu }\mathrm{s}$ for dissipative defects (${\mu }_i<0$). The proposed approach reproduces the attenuation and phase behavior of classical Biot-type and Kelvin–Voigt models with deviations below $5\%$ while providing a richer energetic interpretation of local defect dynamics. Although primarily theoretical, this study establishes a physically consistent and quantitatively validated framework that supports the development of predictive ultrasonic indicators for the energetic classification of defects in concrete structures. Full article

We experimentally investigate the structural, magnetic, transport, and electronic properties of two d⁵ iridate double perovskite materials La₂BIrO₆ (B = Mg, Zn). Notably, despite similar crystallographic structure, the two compounds show distinctly different magnetic behaviors. The M = Mg compound shows an antiferromagnetic-like linear field-dependent isothermal magnetization below its transition temperature, whereas the M = Zn counterpart displays a clear hysteresis loop followed by a noticeable coercive field, indicative of ferromagnetic components arising from a non-collinear Ir spin arrangement. The local structure studies authenticate perceptible M/Ir antisite disorder in both systems, which complicates the magnetic exchange interaction scenario by introducing Ir-O-Ir superexchange pathways in addition to the nominal Ir-O-B-O-Ir super-superexchange interactions expected for an ideally ordered structure. While spin–orbit coupling (SOC) plays a crucial role in establishing insulating behavior for both these compounds, the rotational and tilting distortions of the IrO₆ (and MO₆) octahedral units further lift the ideal cubic symmetry. Finally, by measuring the Ir-L₃ edge resonant inelastic X-ray scattering (RIXS) spectra for both the compounds, giving evidence of spin–orbit-derived low-energy inter-J-state (intra t_2g) transitions (below ~1 eV), the charge transfer (O 2p → Ir 5d), and the crystal field (Ir t_2g → e_g) excitations, we put forward a qualitative argument for the interplay among effective SOC, non-cubic crystal field, and intersite hopping in these two compounds. Full article

This study investigates the structural and magnetic properties of ultra-high coercivity (Fe₈₀B₁₄Nb₆)_0.88Dy_0.12 alloys, doped with 0.5–5 at.% of selected metallic additions: magnetic (Ni, Co) and non-magnetic (Pt, Cu) elements. Material characterization involved both structural and magnetic measurements. Alloys containing dopant concentrations up to 2 at.% exhibited similar phase compositions, with the Dy₂Fe₁₄B compound being dominant. Magnetic hysteresis loops revealed a superposition of two components: magnetically soft and hard phases. A significant change in magnetic properties was observed within the 0.5 to 1 at.% dopant concentration range. Notably, the addition of 0.5 at.% Ni increased the apparent anisotropy field from 5.2 T to 7.5 T. Furthermore, 0.5 at.% Pt led to an increase in the coercive field from 4.6 T to 5.5 T. These additions influenced crystallization, resulting in the formation of a more regular microstructure without submicrometric dendrite branches, when compared to the base alloy. Full article

Improving the isotropic magnetic properties of FeSi electrical steels has traditionally focused on enhancing their crystallographic texture and microstructural morphology. Strengthening the cube texture within a ferritic matrix of optimal grain size is known to reduce core losses and increase magnetic induction. However, conventional cold rolling followed by annealing remains insufficient to optimise the magnetic performance of thin FeSi strips fully. This study explores an alternative approach based on grain boundary migration driven by temperature gradients combined with deformation gradients, either across the sheet thickness or between neighbouring grains, in thin, weakly deformed non-oriented (NO) electrical steel sheets. The concept relies on deformation-induced grain growth supported by rapid heat transport to promote the preferential formation of coarse grains with favourable orientations. Experimental material consisted of vacuum-degassed FeSi steel with low silicon content. Controlled deformation was introduced by temper rolling at room temperature with 2–40% thickness reductions, followed by rapid recrystallisation annealing at 950 °C. Microstructure, texture, and residual strain distributions were analysed using inverse pole figure (IPF) maps, kernel average misorientation (KAM) maps, and orientation distribution function (ODF) sections derived from electron backscattered diffraction (EBSD) data. This combined thermomechanical treatment produced coarse-grained microstructures with an enhanced cube texture component, reducing coercivity from 162 A/m to 65 A/m. These results demonstrate that temper rolling combined with dynamic annealing can surpass the limitations of conventional processing routes for NO FeSi steels. Full article

Young people under the care of child protection agencies are at increased risk of entering the criminal justice system. Residential youth organisations support young people who are unable to reside with their families or in foster care. Youth workers in these environments ensure the safety and wellbeing of young people in their care, consequently supporting the wellbeing of the overall community. This research explored the views and experiences of Queensland residential youth workers via a focus group interview. The data captured a thick description of service delivery practices. Constructivist Grounded Theory was used to conceptualise a theoretical framework based on the various empirical realities of participants. The findings highlight occasions where complex power dynamics had damaging consequences for youth workers and young people. Participants explored systemic constraints and structural inequalities, thus detailing the implications of top-down organisational structures on their service delivery, safety, and outcomes for young people. Participants were concerned about the implications of interrupted attachment and young people’s progression into crime. Practice recommendations centre around improving the disconnection between front-line realities and systemic hierarchies. Residential out-of-home care service delivery should focus on building community connection and belonging; mental, emotional and physical safety; collaborative care; and support. Full article

The term ziran first appears in the Daodejing, yet its precise meaning and attribution remain ambiguous in this book, sparking ongoing scholarly debate. This paper argues that Laozi’s idea of ziran fundamentally pertains to all things and the common people, rather than the Dao or the ruler, and its realization depends on the noncoercive action (wuwei, 無為) of the Dao and the ruler. While ziran is commonly understood as “natural” or “free from external force”, Laozi reinterprets it beyond its literal meaning, integrating the notion of order through its relationship with wuwei and thus imbuing it with theoretical significance. In this framework, ziran encompasses orders of internal senses and orders of external activities inherent in all things while simultaneously excluding excessive and disorderly desires. It thereby serves as a criterion for assessing the orderliness of desires. Furthermore, by elucidating ziran as the continuous transformation of things, the standard to which the ideal ruler or the sage resorts to curb the disorderly desires of the common people is established. Full article

Background/Objectives: Coercive measures remain a common practice in mental health, despite ethical concerns, potential risks, and uncertain efficacy. Mental healthcare workers’ (MHCWs) attitudes toward coercion can influence their use. However, research in Italy is limited. This study aimed to investigate Italian MHCWs’ attitudes toward coercion and their associations with sociodemographic and professional characteristics. Methods: A cross-sectional study was conducted on 356 MHCWs from a mental health department in Southern Italy. Participants completed the Staff Attitude to Coercion Scale (SACS), which assesses negative, pragmatic, and positive attitudes toward coercion. Descriptive statistics (i.e., frequencies, percentages, means) and bivariate analyses (i.e., one-way ANOVA) were used to explore the associations between variables. Results: The majority of participants were male (56.7%), nurses (50.3%), and worked in acute psychiatric settings (52%), with a mean age of 51.08 years (±10.59) and 13.74 years (±12.14) of experience in mental health. Attitudes differed significantly according to age, sex, professional role, and work setting. More negative attitudes were found among staff in residential settings and non-caring roles (p < 0.001). Pragmatic attitudes were lower among older staff (p = 0.012) and among those in residential settings and non-caring roles (p < 0.001). Positive attitudes were higher among males (p = 0.001), nursing staff (p < 0.001), and staff in acute settings (p = 0.049). Conclusions: Italian MHCWs reported different attitudes toward coercion, which was influenced by personal and professional factors. These findings highlight the need for targeted interventions and policy strategies to promote attitudinal change, particularly in settings where positive attitudes are prevalent. Full article

Background/Objectives: The administration of parenteral medications is essential in managing acute arousal within the Behavioral Assessment Unit (BAU) of the emergency department (ED), where timely and effective intervention is critical. This study aims to evaluate current practices surrounding the use of parenteral medications for patients with acute agitation, focusing on adherence to protocols, medication safety, documentation accuracy, and patient outcomes. Methods: A retrospective analysis was conducted on 177 cases from December 2023 to February 2024. The study assessed the demographics, diagnoses, treatment protocols, and patient outcomes, with a particular emphasis on the use of parenteral medications such as benzodiazepines and antipsychotics. The relationship between medication administration and involuntary admission, mechanical restraint usage, and patient outcomes was also explored. Results: The majority of patients were aged between 21 and 30 years, and there was a predominance of male patients across both groups. Schizophrenia was the most common diagnosis, with a higher prevalence in the parenteral group (34%) compared to the oral-only group (24%), and personality disorders were more frequent in the parenteral group. Intramuscular (IM) medication administration was strongly associated with the use of mechanical restraint, with patients receiving IM medication being 35 times more likely to require restraint, emphasizing the link between more intensive treatment approaches and behavioral challenges. The most frequently administered medications were diazepam (40.6%) and olanzapine (36.5%), with olanzapine, droperidol, and diazepam most commonly used parenterally. Documentation of physical assessments prior to parenteral administration was present in most cases, though comprehensive evaluations such as ECGs were inconsistently performed. Conclusions: Parenteral medications, including benzodiazepines and antipsychotics, were effective in rapidly stabilizing patients, but the study emphasizes reducing dependency on mechanical restraints. Tailoring treatment to patient characteristics and employing alternative de-escalation strategies can improve safety and align with recovery-oriented care. This study highlights the need for evidence-based practices to optimize care and improve patient outcomes in ED settings. Further research is needed to explore long-term outcomes and refine non-coercive care approaches. Full article

This study intends to understand the effect of annealing behavior on the microstructure and mechanical and magnetic properties of cold-rolled extra-low-carbon steel. Deformed steel samples are annealed at temperature ranges of 200–690 °C followed by air-cooling. As part of this study, Magnetic Hysteresis loop (MHL) and Barkhausen emission (MBE) measurements are carried out for non-destructive evaluation (NDE) of the mechanical properties that are altered during annealing, viz. recovery and recrystallization. At low annealing temperature ranges 200 < T < 550 °C, the recovery causes no substantial variations in microstructure, hardness value from 191–185 HV, and tensile strength 456–452 MPa, while magnetic coercivity decreases from 293–275 A/m for cold-rolled annealed steels. The microstructural changes due to recovery and recrystallization are examined using transmission electron microscopy and orientation imaging microscopy (OIM) through electron backscattered diffraction (EBSD). Recrystallization is found after annealing at T > 550 °C, confirmed by the lowering of the microstructural KAM value from 0.81° to 0.65° and a hardness drop from 190.02 to 98 HV for cold-rolled extra-low-carbon steel. Full article

Recreational hunting is a highly regulated activity, in part because it can give rise to a variety of deleterious social, environmental, and economic harms. It provides an interesting area for those interested in community safety because of the way in which both formal (e.g., enforcement officers, proscribed areas and times for hunting, licensing, etc.) and informal (e.g., community awareness and education, conservation) methods of crime prevention are applied. And yet, the criminological literature on effective regulation is not only limited but diverse in terms of scope, types of behavior considered (e.g., poaching, wildlife trading, recreation, etc.), and the context that is considered (e.g., geographical, cultural, etc.). In this paper, we present how a crime prevention and compliance response can be used to understand the nature of the issue and the individual and socio-political processes that result in non-compliance with hunting regulations. We present an overview of the status of recreational hunting in an Australian jurisdiction and locate the regulatory issues that arise within the research literature that explores the various motivations that are known to drive illegal hunting. These are then considered in relation to how community-oriented and non-coercive measures might be employed to improve prevent criminal behavior at the primary, secondary, and tertiary levels. Full article

With the rapid development of electric vehicles (EVs), vehicle-to-grid has become a common way to participate in grid regulation. However, in the traditional vehicle-to-grid strategy, the disorganized or coercive regulatory characteristics of EVs always affect the overall satisfaction of EV users and the safe and economic operation of the distribution network. It is challenging to balance the interests of road network subjects. For this reason, this paper proposes an orderly charging and discharging strategy for electric vehicles with integrated consideration of user and distribution grid benefits. First, a comprehensive EV user satisfaction model that considers the vehicle owner’s travel costs is established by considering the vehicle’s travel status and the road resistance characteristics of the road network. Further, the EV orderly charging and discharging model is established to optimize the operation cost of the distribution network, voltage deviation, and EV users’ comprehensive satisfaction, which takes into account the vehicle owner’s satisfaction and the stable operation of the distribution network. Finally, the proposed strategy is validated using the IEEE 33-node arithmetic example. The results show that the peak-to-valley load difference of the distribution network under the strategy of this paper is 29.52% lower than that under the EV non-participation regulation strategy. Compared with the EV non-participation strategy, it can effectively reduce the single-day operation cost of the system by 2.47%. Full article

We study a Dirichlet $\mu$-parametric differential problem driven by a variable competing exponent operator, given by the sum of a negative p-Laplace differential operator and a positive q-Laplace differential operator, with a multivalued reaction term in the sense of a Clarke subdifferential. The parameter $\mu \in \mathbb{R}$ makes it possible to distinguish between the cases of an elliptic principal operator $(\mu \le 0$) and a non-elliptic principal operator ($\mu >0$). We focus on the well-posedness of the problem in variable exponent Sobolev spaces, starting with energy functional analysis. Using a Galerkin approach with a priori estimate and embedding results, we show that the functional associated with the problem is coercive; hence, we prove the existence of generalized and weak solutions. Full article