Search Results (3,637)

Spinal cord injury (SCI) often results in long-term locomotor impairments, and strategies to enhance functional recovery remain limited. While epidural electrical stimulation (EES) has shown clinical promise, our understanding of the mechanisms by which it improves function remains incomplete. Here, we use genetic tools in an animal model to perform neuromodulation and treadmill rehabilitation in a manner similar to EES, but with the benefit of the genetic tools and animal model allowing for targeted manipulation, precise quantification of the cells and circuits that were manipulated, and the gathering of extensive kinematic data. We used a viral construct that selectively transduces large diameter afferent fibers (LDAFs) with a designer receptor exclusively activated by a designer drug (hM3Dq DREADD; a chemogenetic construct) to increase the excitability of large fibers specifically, in the rat contusion SCI model. As changes in locomotion with afferent stimulation can be subtle, we carried out a detailed characterization of the kinematics of locomotor recovery over time. Adult Long-Evans rats received contusion injuries and direct intraganglionic injections containing AAV2-hSyn-hM3Dq-mCherry, a viral vector that has been shown to preferentially transduce LDAFs, or a control with tracer only (AAV2-hSyn-mCherry). These neurons then had their activity increased by application of the designer drug Clozapine-N-oxide (CNO), inducing tonic excitation during treadmill training in the recovery phase. Kinematic data were collected during treadmill locomotion across a range of speeds over nine weeks post-injury. Data were analyzed using a mixed effects model chosen from amongst several models using information criteria. That model included fixed effects for treatment (DREADDs vs. control injection), time (weeks post injury), and speed, with random intercepts for rat and time point nested within rat. Significant effects of treatment and treatment interactions were found in many parameters, with a sometimes complicated dependence on speed. Generally, DREADDs activation resulted in shorter stance duration, but less reduction in swing duration with speed, yielding lower duty factors. Interestingly, our finding of shorter stance durations with DREADDs activation mimics a past study in the hemi-section injury model, but other changes, including the variability of anterior superior iliac spine (ASIS) height, showed an opposite trend. These may reflect differences in injury severity and laterality (i.e., in the hemi-section injury the contralateral limb is expected to be largely functional). Furthermore, as with that study, withdrawal of DREADDs activation in week seven did not cause significant changes in kinematics, suggesting that activation may have dwindling effects at this later stage. This study highlights the utility of high-resolution kinematics for detecting subtle changes during recovery, and will enable the refinement of neuromechanical models that predict how locomotion changes with afferent neuromodulation, injury, and recovery, suggesting new directions for treatment of SCI. Full article

Background/Objectives: Paramedics frequently encounter potentially traumatic events and workplace violence, increasing their risk of burnout. Resilience may attenuate these effects. We examined the pathways through which post-traumatic stress (PTS) and workplace violence influence burnout and clarified the role of resilience among Korean paramedics. Methods: We studied duty-related trauma and violence experienced by 208 Busan Fire Department paramedics using standardized measures of PTS, workplace violence, resilience, and burnout. Using structural equation modeling, we tested the direct and indirect effects; covariates included sex, nursing license, and intention to stay. Results: PTS was most strongly associated with burnout, whereas workplace violence was indirectly associated with burnout through PTS. Resilience reduced PTS, yielding an indirect protective effect on burnout; however, it had no direct effect on burnout. Holding a nursing license and lack of intention to stay were significantly associated with burnout, and female sex and lack of intention to stay were indirectly associated with burnout via PTS. Conclusions: Burnout is primarily driven by PTS, and workplace violence amplifies PTS and indirectly exacerbates burnout. Strengthening violence prevention/response systems, early PTS screening/treatment, and resilience-building programs is warranted, with targeted support for vulnerable subgroups. Full article

In this article, we explain how Kant upends the terms of the debate concerning the relationship between God’s existence and an objective morality by looking at his moral-teleological argument for God’s existence in the third Critique. We explain Kant’s rejection of external sources of moral normativity and his method of grounding moral authority in the normativity of practical reason. We then turn to Kant’s argument justifying a practical belief in God as the moral author of nature. Kant’s claims about how we must conceptualize organisms teleologically and, as a result, how reason seeks an unconditioned end of nature, brings together our moral purpose with a conception of nature as an organized whole. Since our teleological concepts of organisms seem to require that human beings serve as the final, unconditioned end of nature, but morality and nature might be incompatible and divergent, we must also believe in a moral author of nature. This belief guards against demoralization and creates a unified view of the human moral agent and the world she inhabits, which Kant thinks of as indispensable for our practical lives. Kant notoriously blurs the lines between theology and ethics in nonstandard ways. Although he rejects many traditional approaches to grounding ethics in a conception of divine commands or eternal law, he still devotes a considerable amount of time to discussing the role of religion as a bulwark of the moral life. The goal of this paper is to defend Kant’s relevance to a discussion of the relationship between an objective ethics and the existence of God; his contribution deserves our notice precisely for the ways in which it promises to shift the terms of the contemporary debate and complicate possible answers to the question of whether there can be an objective morality without God. In contemporary philosophical literature, Kant’s argument contending that we must hope in God from a practical point of view on pain of irrationality of acting from duty has enjoyed substantial discussion. Here, however, we focus on a lesser-known suite of arguments that in order to so much as cognize ourselves and other species as the sorts of natural beings they are, we must believe in a supersensible moral author of these natures. This set of arguments ultimately dovetail with the more well-known argument for theistic hope and operate in much the same way. But they touch on facets of Kant’s whole philosophical system, such as his account of teleological judgment and the unity and final end of all of nature. Our goal is to explicate these arguments and illuminate their relevance of these Kantian arguments to the debate about the relevance of God to objective morality. We will argue that while an objective ethics is possible without God due to the active role of practical reason in rational agents, belief in God’s existence strengthens the claims of morality, both for psychological reasons but also by providing a more unified conception of moral and natural reality. Full article

Prior work established the presence of six crosscutting patterns of clinically significant family maltreatment (FM) and psychological health (PH) problems among active-duty service members. Here, we develop a brief screener for these patterns via Classification and Regression Trees (CART) analyses using a sample of active-duty members of the United States Air Force. CART is a predictive algorithm used in machine learning. It balances prediction accuracy and model parsimony to identify an optimal set of predictors and identifies the thresholds on those predictors in relation to a discrete condition of interest (e.g., diagnosis of pathology). A 22-item screener predicted membership in five of the six classes (sensitivities and specificities > 0.96; positive and negative predictive values > 0.90). However, for service members at extremely high risk of clinically significant externalizing behavior, sensitivity and positive predictive values were much lower. The resulting 22-item brief screener can facilitate feasible, cost-effective detection of five of the six identified FM and PH problem patterns with a small number of items. The sixth pattern can be predicted far better than chance. Researchers and policymakers can use this tool to guide prevention efforts for FM and PH problems in service members. Full article

Fuel cell trucks are a promising solution to reduce the disproportionately high greenhouse gas emissions of heavy-duty long-haul transportation. However, unlike conventional diesel vehicles, they lack combustion engine waste heat for cabin heating. As a result, electric heaters are often employed, which increase auxiliary energy consumption and reduce driving range. To address this challenge, advanced control strategies are needed to improve heating efficiency while maintaining passenger comfort. This study proposes and validates a methodology for implementing Model Predictive Control (MPC) in the cabin heating system of a fuel cell truck. Vehicle experiments were conducted to characterize dynamic heating behavior, passenger comfort indices, and to provide validation data for the mathematical models. Based on these models, an MPC strategy was developed in a Model-in-the-Loop simulation environment. The proposed approach achieves energy savings of up to 8.1% compared with conventional control using purely electric heating, and up to 21.7% when cabin heating is coupled with the medium-temperature cooling circuit. At the same time, passenger comfort is maintained within the desired range (PMV within ±0.5 under typical winter conditions). The results demonstrate the potential of MPC to enhance the energy efficiency of fuel cell trucks. The methodology presented provides a validated foundation for the further development of predictive thermal management strategies in heavy-duty zero-emission vehicles. Full article

There are various mechanisms through which water droplets can be present in compressor flows, e.g., rain ingestion in aeroengines or overspray fogging used in heavy-duty gas turbines to boost power output. For the latter, droplet evaporation within the compressor leads to a cooling of the flow as well as to a shift in the fluid properties, which is beneficial to the overall process. However, due to their inertia, the majority of droplets are deposited in the first stages of a multistage compressor. While this phenomenon is generally considered in CFD computations of droplet-laden flows, the subsequent re-entrainment of collected water, the formation of new droplets, and the impact on the overall evaporation are mostly neglected because of the additional computational effort required, especially with regard to the modeling of films formed by the deposited water. The work presented here shows an approach that allows for the integration of the process of droplet deposition and re-entrainment based on relatively simple correlations and experimental observations from the literature. Thus, the two-phase flow in multistage compressors can be modelled and analyzed very efficiently. In this paper, the models and assumptions used are described first, then the results of a study performed based on a generic multistage compressor are presented, whereby the various models are integrated step by step to allow an assessment of their impact on the droplet evaporation throughout the compressor and overall performance. It can be shown that evaporation becomes largely independent of droplet size when deposition on both rotor and stator and subsequent re-entrainment of collected water is considered. In addition, open issues with regard to the future improvement of models and correlations of two-phase flow phenomena are highlighted based on the results of the current investigation. Full article

Battery cell balancing is crucial in series-connected lithium-ion packs to maximize usable capacity, ensure safe operation, and prolong cycle life. This paper presents a comprehensive study and a novel adaptive duty-cycled hybrid balancing system that combines passive bleed resistors and an active switched-capacitor (SC) balancer, specifically designed for a 4-cell series-connected battery pack. This work also explored open circuit voltage (OCV)-driven adaptive pulse-frequency modulation (PFM) active balancing to achieve higher efficiency and better balancing speed based on different system requirements. Finally, this paper compares passive, active (SC-based), and adaptive duty-cycled hybrid balancing strategies in detail, including theoretical modeling of energy transfer and efficiency for each method. Simulation showed that the adaptive hybrid balancer speeds state-of-charge (SoC) equalization by 16.24% compared to active-only balancing while maintaining an efficiency of 97.71% with minimal thermal stress. The simulation result also showed that adaptive active balancing was able to achieve a high efficiency of 99.86% and provided an additional design degree of freedom for different applications. The results indicate that the adaptive hybrid balancer offered an excellent trade-off between balancing speed, efficiency, and implementation simplicity for 4-cell Li-ion packs, making it highly suitable for applications such as high-voltage portable chargers. Full article

This study evaluates media-level filtration behaviour and short-term fuel consumption outcomes for five spin-on lubricating oil filters operated under real driving conditions at high altitude. To improve interpretability, filters are reported using parameter-based identifiers (media descriptors and equivalent circular diameter, ECD) rather than internal codes. Pore-scale morphology was quantified by microscopy and expressed as ECD, and bulk fluid cleanliness was summarised using ISO 4406 codes. Trials were conducted over representative urban and extra-urban routes at altitude; fuel consumption was analysed using ANCOVA. The results indicated clear media-level differences (tighter pore envelopes and cleaner ISO codes, particularly for two OEM units). However, fuel-consumption differences were not statistically significant (ANCOVA, p = 0.29). Accordingly, findings are reported as short-term cleanliness and media characterisation under high-altitude duty rather than durability or efficiency claims. The parameter-based framing clarifies trade-offs across metrics and avoids over-generalisation from brand or part numbers. The work highlights the value of ECD as a comparative pore metric and underscores limitations of microscopy/cleanliness data for inferring engine wear or long-term consumption. Future work will incorporate formal multi-pass testing (ISO 4548-12), direct differential-pressure instrumentation, used-oil viscosity tracking, and wear-metal spectrometry to enable cross-vendor benchmarking and causal interpretation. Findings are presented as short-term cleanliness and media characterisation; no durability claims are made in the absence of direct wear measurements. Full article

This article proposes an improved Visible Light Communication (VLC) solution that, besides the indoor lighting and data transfer, offers an energy-efficient alternative for modern workspaces. Unlike Light-Fidelity (LiFi), designed for high-speed data communication, VLC primarily targets applications where fast data rates are not essential. The developed prototype ensures reliable communication under variable lighting conditions, addressing low-speed requirements such as test bench monitoring, occupancy detection, remote commands, logging or access control. Although the tested data rate was limited to 100 kb/s with a Bit Error Rate (BER) below 10⁻⁷, the key innovation is the light dimming dynamic adaptation. Therefore, the system self-adjusts the LED duty cycle between 10% and 90%, based on natural or artificial ambient light, to maintain a minimum illuminance of 300 lx at the workspace level. Additionally, this work includes a scalability analysis through simulations conducted in an office scenario with up to six users. The results show that the system can adjust the lighting level and maintain the connectivity according to users’ presence, significantly reducing energy consumption without compromising visual comfort or communication performance. With this light intensity regulation algorithm, the proposed solution demonstrates real potential for implementation in smart indoor environments focused on sustainability and connectivity. Full article

This study investigates the effects and mechanisms of high-power microwave on GaN HEMTs. By injecting high-power microwave from the gate into the device and employing techniques such as DC characteristics, gate-lag effect analysis, low-frequency noise measurement, and focused ion beam (FIB) cross-sectional inspection, a systematic investigation was conducted on GaN HEMT degradation and failure behaviors under conditions of a low duty cycle and narrow pulse width. Experimental results indicate that under relatively low-power HPM stress, GaN HEMT exhibits only a slight threshold voltage shift and a modest increase in transconductance, attributed to the passivation of donor-like defects near the gate. However, when the injected power exceeds 43 dBm, the electric field beneath the gate triggers avalanche breakdown, forming a leakage path and causing localized heat accumulation, which ultimately leads to permanent device failure. This study reveals the physical failure mechanisms of GaN HEMTs under low-duty-cycle HPM stress and provides important guidance for the reliability design and hardening protection of RF devices. Full article

Peer review fails when it is delivered without fairness, accountability, or respect. When unprofessional reviews are communicated without editorial intervention, they undermine trust, distort scientific dialogue, and disproportionately harm early-career and underrepresented researchers. This article combines a detailed case study with evidence from the literature to illustrate how reviewer misconduct can escalate into editorial failure, and why such outcomes are avoidable. Mechanisms already exist to prevent them, including pre-screening, structured review forms, training, appeals processes, and reviewer tracking, but require consistent application. The central problem is not the absence of guidance, but the lack of enforcement. Restoring credibility in peer review depends on editors treating oversight as a duty of stewardship, ensuring that critique remains rigorous, constructive, and respectful. Full article

This work introduces a non-isolated high step-up dc-dc interleaved boost converter combining magnetic coupling and voltage multiplier cells (VMCs). The proposed topology features a transformer with two primary windings of equal turns, interconnected to each other, enabling improved current sharing, and multiple secondary windings that contribute to extending the voltage gain. A three-winding coupled inductor is integrated into the design, while VMCs not only boost the output voltage but also significantly reduce the voltage stresses on the switches, eliminating the need for extreme duty ratios. The converter exhibits inherent modularity, allowing for voltage gain adjustments either through the turns ratio of the coupled inductor or by incorporating additional VMCs. An in-depth analysis of the topology is derived, and an experimental prototype rated at 48 V/400 V, 25 kHz, and 1 kW is implemented to verify and validate the theoretical claims, achieving an efficiency of 95.12% at full-load conditions. Full article

This paper proposes an enhanced Model Predictive Direct Speed Control (MPDSC) framework for Permanent Magnet Synchronous Motor (PMSM) drives, integrating duty ratio optimization and load torque disturbance compensation to significantly improve both transient and steady-state performance. Traditional finite-control-set MPC strategies, which apply a single voltage vector per sampling interval, often suffer from steady-state ripples, elevated total harmonic distortion (THD), and high computational complexity due to exhaustive switching evaluations. The proposed approach addresses these limitations through a novel dual-stage cost function structure: the first cost function optimizes dynamic response via predictive control of speed error, while the second adaptively minimizes torque ripple and harmonic distortion by adjusting the active–zero voltage vector duty ratio without the need for manual weight tuning. Robustness against time-varying disturbances is further enhanced by integrating a real-time load torque observer into the control loop. The scheme is validated through both MATLAB/Simulink R2020a simulations and real-time experimental testing on a dSPACE 1202 rapid control prototyping platform across small- and large-scale PMSM configurations. Experimental results confirm that the proposed controller achieves a transient speed deviation of just 0.004%, a steady-state ripple of 0.01 rpm, and torque ripple as low as 0.0124 Nm, with THD reduced to approximately 5.5%. The duty ratio-based predictive modulation ensures faster settling time, improved current quality, and greater immunity to load torque disturbances compared to recent duty-ratio MPC implementations. These findings highlight the proposed DR-MPDSC as a computationally efficient and experimentally validated solution for next-generation PMSM drive systems in automotive and industrial domains. Full article

Aluminum and its alloys are widely used in aerospace and industrial sectors due to their high specific strength, low density, and abundance. However, their low hardness, high corrosion susceptibility, and poor wear resistance limit broader applications. Surface treatments such as electroplating, PVD/CVD, and anodizing have been used to enhance surface properties. Plasma electrolytic oxidation (PEO), also known as micro-arc oxidation (MAO), has emerged as a promising technique for producing durable ceramic coatings on light metals like Al, Mg, and Ti alloys. In this study, PEO was applied to AA6061 aluminum alloy using an AC power source in potentiostatic mode at 350 V and 400 V, 1000 Hz, and 80% duty cycle for 30 min in a silicate-based electrolyte (5 g/L Na₂SiO₃ + 5 g/L KOH) maintained at 25–40 °C. The effect of voltage on the coating morphology, thickness, and corrosion resistance was investigated. The coatings exhibited porous structures with pancake-like, crater, and nodular features, and thicknesses ranged from 0.053 to 83.64 µm. XRD analysis confirmed the presence of Al, α-Al₂O₃, Ƴ-Al₂O₃, and mullite. The 400 V-coated sample showed superior corrosion resistance ( $E_{corr}= -0.77 \mathrm{V}$; $i_{corr}=0.28 \mu \mathrm{A}/{\mathrm{c}\mathrm{m}}^2$) and improved hardness (up to 233 HV), compared to 89 HV for the bare AA6061. Full article

In order to solve the problem of the efficiency reduction and complex manufacturing of traditional grating couplers under environmental temperature fluctuations, a Si₃N₄ high-efficiency grating coupler integrating a distributed Bragg reflector (DBR) and thermo-optical tuning layer is proposed. In this paper, the double-layer DBR is used to make the down-scattered light interfere with other light and reflect it back into the waveguide. The finite difference time domain (FDTD) method is used to simulate and optimize the key parameters such as grating period, duty cycle, incident angle and cladding thickness, achieving a coupling efficiency of −1.59 dB and a 3 dB bandwidth of 106 nm. In order to further enhance the temperature stability, the amorphous silicon (a-Si) thermo-optical material layer and titanium metal serpentine heater are embedded in the DBR. The reduction in coupling efficiency caused by fluctuations in environmental temperature is compensated via local temperature control. The simulation results show that within the wide temperature range from −55 °C to 150 °C, the compensated coupling efficiency fluctuation is less than 0.02 dB, and the center wavelength undergoes a blue shift. This design is compatible with complementary metal-oxide-semiconductor (CMOS) processes, which not only simplifies the fabrication process but also significantly improves device stability over a wide temperature range. This provides a feasible and efficient coupling solution for photonic integrated chips in non-temperature-controlled environments, such as optical communications, data centers, and automotive systems. Full article