Mechanical Power Research Articles

Speed of lung inflation at birth influences the initiation of lung injury in preterm lambs.

Gas flow is fundamental for driving tidal ventilation and, thus, the speed of lung motion, but current bias flow settings to support the preterm lung after birth do not have an evidence base. We aimed to determine the role of gas bias flow rates to generate positive pressure ventilation in initiating early lung injury pathways in the preterm lamb. Using slower speeds to inflate the lung during tidal ventilation (gas flow rates 4-6 L/min) did not affect lung mechanics, mechanical power, or gas exchange compared with those currently used in clinical practice (8-10 L/min). Speed of pressure and volume change during inflation were faster with higher flow rates. Lower flow rates resulted in less bronchoalveolar fluid protein, better lung morphology, and fewer detached epithelial cells. Overall, relative to unventilated fetal controls, there was greater protein change using 8-10 L/min, which was associated with enrichment of acute inflammatory and innate responses. Slowing the speed of lung motion by supporting the preterm lung from birth with lower flow rates than in current clinical use resulted in less lung injury without compromising tidal ventilation or gas exchange.

A qualitative investigation of tattooing as an adaptive appearance investment: positive body image and eating disorder recovery in a predominantly transgender and gender expansive sample

ABSTRACT Tattooed individuals often express the positive effects of wearing body art toward improved self-image and confidence. This research builds on prior data exploring the positive effects of tattooing and investigates how tattoos impact one’s relationship to eating disorder (ED) recovery and body image. We held three focus groups lasting 60 minutes each, recruiting participants via purposive snowball sampling (n = 15), with additional opportunities to respond to focus group prompts asynchronously. Eligible participants were individuals with lived experience of an ED, self-identified as being in recovery, had three or more tattoos, and spoke English. Participants predominantly held gender-expansive (n = 4 Non-Binary, n = 3 Genderqueer, n = 3 Cisgender Women, n = 3 Transgender, n = 2 Transmasculine, n = 2 Gender Non-Conforming, n = 2 Intersex, n = 1 Cisgender Man) and non-heterosexual identities. Focus groups were held between April 2021 and July 2023 and followed a semi-structured interview format. Primary analyses focused on participants’ responses to open-ended prompts regarding how they understood the relationships between tattooing, body image, and ED recovery. Thematic analysis identified four core themes: Tattooing allowing for embodiment, tattooing allowing for recovery-oriented behaviors, tattooing enabling positive body image, and tattooing facilitating empowerment. An overarching message was that tattooing is a therapeutic and transformative process, allowing for self-determination. Participants indicated that tattooing can be experienced as a powerful mechanism for behavioral change and shifts in relationship to one’s body. Participants expressed that tattooing can be an effective route towards both gender euphoria and body liberation, enhancing one’s ability to maintain ED recovery.

ИСПОЛЬЗОВАНИЕ ПУБЛИЧНО-ЧАСТНОГО ПАРТНЁРСТВА НА СЕЛЬСКИХ ТЕРРИТОРИЯХ

A study of successful examples of public-private partnerships in rural areas shows that a community of public and private structures contributes to the effective use of resources and the improvement of innovative technologies. Such partnerships can be a powerful mechanism for the progress of all economic sectors and the growth of security and state well-being. Public-private partnerships in rural areas make it possible to synthesize the forces of the state and private business to resolve issues of their transformation and improvement. This allows you to increase production volumes, create new jobs and cultivate the economic potential of rural areas

Task shifting for musculoskeletal disorders in Norwegian primary care: a qualitative interview study of general practitioners and specialist musculoskeletal physiotherapists

Objective To explore the views of general practitioners and physiotherapists on the current model of care for patients with musculoskeletal disorders in Norwegian primary care, and if the English First Contact Practitioner model, where patients have access to multiple professional groups with musculoskeletal health expertise, could inform service development. Design, setting, and subjects We analysed interviews with five GPs and 11 physiotherapists and used Lipsky’s theories about street-level bureaucracy and Foucault’s theories of mechanisms of power and institutional structures to explore task shifting and cooperation between different professions. Results and interpretation The empirical material reflected a multi-faceted discourse about skill-mix in primary care, where financial factors, perceptions about competence, and task preferences moderated attitudes to task shifting. Competition and cooperation coexist between the professions, and the seemingly gradual blurring between historical hegemony and new models of care creates both alliances and rivalries. Examples of deviations from the Choosing Wisely principles and evidence-based practice indicate that both general practitioners and physiotherapists balance the roles of patient advocate, gatekeeper, and homo economicus, in a context where task shifting is challenged by established practice. It appears that the management of patients with musculoskeletal disorders is fragmented and to some extent reflects a supply-driven system.

Numerical study of a low power hydrokinetic turbine

ABSTRACT In a hydrokinetic turbine, the flow completely surrounds the turbine allowing it to convert the kinetic energy of the water to mechanical power. The general objective of this work is the numerical study of a low power axial flow hydroelectric turbine using CFD (Computational Fluid Dynamics). The scope of this work includes a CFD analysis of a hydroelectric turbine, including the rotor, hub and casing, a comparison between results of steady and transient solvers, and the turbine performance in design and off-design conditions. Three-dimensional simulations were carried out using ANSYS Fluent software, with the aim of estimating the design loads and determining the nominal operating conditions, including results of steady and transient simulations. Results were obtained with the k-ω SST turbulence model and the SIMPLEC calculation algorithm, in structured and unstructured meshes, which involve stationary and rotating domains.

Effect of the prone position on mechanical power in elective surgical patients under general anesthesia: A prospective observational study.

To evaluate how the prone position influences mechanical power (MP) during elective surgical procedures. In this prospective study carried out at Karadeniz Ereğli Government Hospital, Zonguldak, Turkey, from January 2024 to February 2024, 76 patients under general anesthesia were evaluated at different time points during the surgical procedure. Hemodynamic, laboratory, and mechanical ventilation data were also recorded. The MP increased in the prone position at the beginning of surgery. Transitioning to the supine position at the end of surgery led to a decrease in MP. At the end of surgery, the mean MP in supine and prone positions was found to be higher compared to those measured in the first hour of surgery. Mechanical power and body mass index (BMI) exhibited a significant positive correlation. Position changes influence MP. Returning to the prone position increases MP. An increase in BMI is associated with an increase in MP.ANZCTR Reg. No.: ACTRN12623001281684.

Systemic Paralysis and Systemic Deterrence as Power Mechanisms of Change Failure

Systemic Paralysis and Systemic Deterrence as Power Mechanisms of Change Failure

ЕФЕКТИВНЕ ДЕРЖАВНЕ УПРАВЛІННЯ І НАЦІОНАЛЬНА БЕЗПЕКА В КОНТЕКСТІ DEEP STATE

The article explores the concept of the «deep state» as a key element of ensuring sustainable public administration and national security in war and peace. The author examines global and regional development trends that affect the formation of national security and analyses the mechanisms of power and governance in different countries. Particular attention is paid to the role of informal and closed networks in influencing official policy, which allows for a deeper understanding of the sources of information wars and manipulation of public opinion. The relevance of the study is driven by the need to build a transparent, fair and democratic society, as well as to strengthen democratic institutions and protect the rights and freedoms of citizens. The analysis of the deep state allows us to identify the interconnections between state institutions, the military, intelligence services and big business, which often remain outside democratic control. The author notes that the study of the deep state is important for the protection of democratic values, increasing transparency, accountability and efficiency of governance. Particular attention is paid to the influence of the deep state on the information space and the mechanisms of manipulating public opinion through the media. Understanding these processes contributes to the development of critical thinking and the protection of citizens' rights and freedoms. In the context of globalisation, the concept of the deep state is seen as an important factor influencing international relations, trade policies and economic alliances. The study of this phenomenon helps to predict changes in global politics and the economy, which is important for the development of long-term national security strategies. The term «deep state» is used to describe a network of influential individuals or organisations that can exert significant influence on public policy beyond democratic control. This concept is actively discussed in political debates, causing controversy over its role and influence on political processes.

Stationary steam power in the United Kingdom, 1800–70: An empirical reassessment

AbstractThe conventional view that the industrial revolution was premised on the unprecedented supply of mechanical power delivered via steam engines has been undermined by econometric work, purporting to show that their adoption outside the cotton and mining sectors was extremely limited until at least 1870. This was largely because water and wind power remained viable and cost‐competitive substitutes long into the nineteenth century. Using evidence from a newly compiled ‘census’ of stationary power installations in Suffolk, this paper demonstrates instead that the adoption of steam power was far greater than previously thought, especially in manufacturing. Moreover, the assumption that steam could be invariably substituted with environmental forces is untenable. Depending on circumstances, even very modest power requirements could only be met with steam. Although the quantitative picture remains incomplete, steam power was likely an indispensable sustentative factor for industrialization.

Effect of automated versus conventional ventilation on mechanical power of ventilation-A randomized crossover clinical trial.

Mechanical power of ventilation, a summary parameter reflecting the energy transferred from the ventilator to the respiratory system, has associations with outcomes. INTELLiVENT-Adaptive Support Ventilation is an automated ventilation mode that changes ventilator settings according to algorithms that target a low work-and force of breathing. The study aims to compare mechanical power between automated ventilation by means of INTELLiVENT-Adaptive Support Ventilation and conventional ventilation in critically ill patients. International, multicenter, randomized crossover clinical trial in patients that were expected to need invasive ventilation > 24 hours. Patients were randomly assigned to start with a 3-hour period of automated ventilation or conventional ventilation after which the alternate ventilation mode was selected. The primary outcome was mechanical power in passive and active patients; secondary outcomes included key ventilator settings and ventilatory parameters that affect mechanical power. A total of 96 patients were randomized. Median mechanical power was not different between automated and conventional ventilation (15.8 [11.5-21.0] versus 16.1 [10.9-22.6] J/min; mean difference -0.44 (95%-CI -1.17 to 0.29) J/min; P = 0.24). Subgroup analyses showed that mechanical power was lower with automated ventilation in passive patients, 16.9 [12.5-22.1] versus 19.0 [14.1-25.0] J/min; mean difference -1.76 (95%-CI -2.47 to -10.34J/min; P < 0.01), and not in active patients (14.6 [11.0-20.3] vs 14.1 [10.1-21.3] J/min; mean difference 0.81 (95%-CI -2.13 to 0.49) J/min; P = 0.23). In this cohort of unselected critically ill invasively ventilated patients, automated ventilation by means of INTELLiVENT-Adaptive Support Ventilation did not reduce mechanical power. A reduction in mechanical power was only seen in passive patients. Clinicaltrials.gov (study identifier NCT04827927), April 1, 2021. https://clinicaltrials.gov/study/NCT04827927?term=intellipower&rank=1.

Configuration optimization of a wind-solar based net-zero emission tri-generation energy system considering renewable power and carbon trading mechanisms

Incorporating renewable energy and carbon trading mechanisms within the optimization methods could enhance both the environmental and economic benefits of energy systems. A tri-generation system powered by solar and wind energy is introduced, utilizing solar photovoltaics, wind turbines, and a solar cooling/heating subsystem to attain net-zero carbon emissions via renewable power and carbon trading mechanisms. An improved multi-objective algorithm optimizes the configurations of the energy system across different scenarios. The optimization results demonstrate that the integration of wind turbines, ideally with capacities near 20 MW, lessens the dependence on external power sources and decreases annual expenditure relative to systems relying solely on photovoltaic. Meanwhile, water-cooled chillers are capable of addressing over 88% of the cooling demand, with capacity exceeding 11 MW. Sensitivity analysis highlights that increasing power grid coverage and microgrid penetration rates decrease total costs, while higher building demands reduce economic performance. A new operating mode of net-zero carbon energy systems is provided in the present study.

Mechanical power ratio threshold for ventilator-induced lung injury

RationaleMechanical power (MP) is a summary variable incorporating all causes of ventilator-induced-lung-injury (VILI). We expressed MP as the ratio between observed and normal expected values (MPratio).ObjectiveTo define a threshold value of MPratio leading to the development of VILI.MethodsIn a population of 82 healthy pigs, a threshold of MPratio for VILI, as assessed by histological variables and confirmed by using unsupervised cluster analysis was 4.5. The population was divided into two groups with MPratio above or below the threshold.Measurements and main resultsWe measured physiological variables every six hours. At the end of the experiment, we measured lung weight and wet-to-dry ratio to quantify edema. Histological samples were analyzed for alveolar ruptures, inflammation, alveolar edema, atelectasis. An MPratio threshold of 4.5 was associated with worse injury, lung weight, wet-to-dry ratio and fluid balance (all p < 0.001). After 48 h, in the two MPratio clusters (above or below 4.5), respiratory system elastance, mean pulmonary artery pressure and physiological dead space differed by 32%, 36% and 22%, respectively (all p < 0.001), being worse in the high MPratio group. Also, the changes in driving pressure, lung elastance, pulmonary artery occlusion pressure, central venous pressure differed by 17%, 64%, 8%, 25%, respectively (all p < 0.001).LimitationsThe main limitation of this study is its retrospective design. In addition, the computation for the expected MP in pigs is based on arbitrary criteria. Different values of expected MP may change the absolute value of MP ratio but will not change the concept of the existence of an injury threshold.ConclusionsThe concept of MPratio is a physiological and intuitive way to quantify the risk of ventilator-induced lung injury. Our results suggest that a mechanical power ratio > 4.5 MPratio in healthy lungs subjected to 48 h of mechanical ventilation appears to be a threshold for the development of ventilator-induced lung injury, as indicated by the convergence of histological, physiological, and anatomical alterations. In humans and in lungs that are already injured, this threshold is likely to be different.

Micro/Nanomotor-Driven Intelligent Targeted Delivery Systems: Dynamics Sources and Frontier Applications.

Micro/nanomotors represent a promising class of drug delivery carriers capable of converting surrounding chemical or external energy into mechanical power, enabling autonomous movement. Their distinct autonomous propulsive force distinguishes them from other carriers, offering significant potential for enhancing drug penetration across cellular and tissue barriers. A comprehensive understanding of micro/nanomotor dynamics with various power sources is crucial to facilitate their transition from proof-of-concept to clinical application. In this review, micro/nanomotors are categorized into three classes based on their energy sources: endogenously stimulated, exogenously stimulated, and live cell-driven. The review summarizes the mechanisms governing micro/nanomotor movements under these energy sources and explores factors influencing autonomous motion. Furthermore, it discusses methods for controlling micro/nanomotor movement, encompassing aspects related to their structure, composition, and environmental factors. The remarkable propulsive force exhibited by micro/nanomotors makes them valuable for significant biomedical applications, including tumor therapy, bio-detection, bacterial infection therapy, inflammation therapy, gastrointestinal disease therapy, and environmental remediation. Finally, the review addresses the challenges and prospects for the application of micro/nanomotors. Overall, this review emphasizes the transformative potential of micro/nanomotors in overcoming biological barriers and enhancing therapeutic efficacy, highlighting their promising clinical applications across various biomedical fields.

Design Considerations Concerning an Innovative Drive System for a Manual Wheelchair

Manual wheelchairs, which are the basic means of transport for people with disabilities, are usually characterized by an inefficient adaptation to the physical capabilities of their users. For this reason, it is advisable to search for solutions that will allow us to change the parameters of the mechanical power generated by human muscles. For this purpose, mechanical gearing known from other solutions, for example, from bicycles, can be used. The paper describes the design methodology and a number of issues related to the construction of an innovative wheelchair prototype using a chain transmission in its drive system. This solution allows for the implementation of a variable ratio between the wheels and the pushrims. Thus, it effectively allows for matching the demand for driving torque to the movement conditions and the physical capabilities of its user. The use of such a system provides the basis for increasing the efficiency of the manual propulsion process. Initial studies show that changing the gear ratio allows for different speeds of the wheelchair wheel. In the tests conducted, the root mean square of this value varied from 15.2 RPM to 35.5 RPM, which resulted in a change in power from 15.8 W to 40.1 W. Of course, the values of rotational speed and torque show a cyclically changing character, which results from the intermittent nature of generating drive by the wheelchair user. The average peak values of rotational speed were 31.4 ± 1.7 RPM, 44.3 ± 3.4 RPM and 57.9 ± 3.4 RPM, while the torque was 12.1 ± 0.5 Nm, 12.4 ± 0.4 Nm and 14.1 ± 0.6 Nm for Gears 1, 4 and 6, respectively.

Streams of conscious visual experience

Consciousness, a cornerstone of human cognition, is believed to arise from complex neural interactions. Traditional views have focused on localized fronto-parietal networks or broader inter-regional dynamics. In our study, we leverage advanced fMRI techniques, including the novel Functionnectome framework, to unravel the intricate relationship between brain circuits and functional activity shaping visual consciousness. Our findings underscore the importance of the superior longitudinal fasciculus within the fronto-parietal fibers, linking conscious perception with spatial neglect. Additionally, our data reveal the critical contribution of the temporo-parietal fibers and the splenium of the corpus callosum in connecting visual information with conscious representation and their verbalization. Central to these networks is the thalamus, posited as a conductor in synchronizing these interactive processes. Contrasting traditional fMRI analyses with the Functionnectome approach, our results emphasize the important explanatory power of interactive mechanisms over localized activations for visual consciousness. This research paves the way for a comprehensive understanding of consciousness, highlighting the complex network of neural connections that lead to awareness.

An Intrinsic Host Defense against HSV-1 Relies on the Activation of Xenophagy with the Active Clearance of Autophagic Receptors.

Autophagy engulfs cellular components in double-membrane-bound autophagosomes for clearance and recycling after fusion with lysosomes. Thus, autophagy is a key process for maintaining proteostasis and a powerful cell-intrinsic host defense mechanism, protecting cells against pathogens by targeting them through a specific form of selective autophagy known as xenophagy. In this context, ubiquitination acts as a signal of recognition of the cargoes for autophagic receptors, which direct them towards autophagosomes for subsequent breakdown. Nevertheless, autophagy can carry out a dual role since numerous viruses including members of the Orthoherpesviridae family can either inhibit or exploit autophagy for its own benefit and to replicate within host cells. There is growing evidence that Herpes simplex virus type 1 (HSV-1), a highly prevalent human pathogen that infects epidermal keratinocytes and sensitive neurons, is capable of negatively modulating autophagy. Since the effects of HSV-1 infection on autophagic receptors have been poorly explored, this study aims to understand the consequences of HSV-1 productive infection on the levels of the major autophagic receptors involved in xenophagy, key proteins in the recruitment of intracellular pathogens into autophagosomes. We found that productive HSV-1 infection in human neuroglioma cells and keratinocytes causes a reduction in the total levels of Ub conjugates and decreases protein levels of autophagic receptors, including SQSTM1/p62, OPTN1, NBR1, and NDP52, a phenotype that is also accompanied by reduced levels of LC3-I and LC3-II, which interact directly with autophagic receptors. Mechanistically, we show these phenotypes are the result of xenophagy activation in the early stages of productive HSV-1 infection to limit virus replication, thereby reducing progeny HSV-1 yield. Additionally, we found that the removal of the tegument HSV-1 protein US11, a recognized viral factor that counteracts autophagy in host cells, enhances the clearance of autophagic receptors, with a significant reduction in the progeny HSV-1 yield. Moreover, the removal of US11 increases the ubiquitination of SQSTM1/p62, indicating that US11 slows down the autophagy turnover of autophagy receptors. Overall, our findings suggest that xenophagy is a potent host defense against HSV-1 replication and reveals the role of the autophagic receptors in the delivery of HSV-1 to clearance via xenophagy.

Dynamic model of magnetic transmission

In the work, a non-contact electromechanical energy converter with permanent magnets, which is known as magnetic transmission, is studied. Magnetic transmissions have certain structural advantages compared to mechanical transmissions, namely: high reliability, efficiency, lower losses, non-contact transmission of mechanical power, no maintenance costs, and simplicity of construction. The use of magnetic transmissions for systems of conversion of low-potential mechanical energy into electrical energy is especially relevant: wind energy, water energy, energy of mechanical vibrations, etc. The use of magnetic gearboxes in autonomous wind power plants can be more promising from an economic and technical point of view compared to traditional mechanical transmissions. A numerical simulation mathematical model of magnetic transmission with permanent magnets has been developed. The use of magnetic transmission, for example, for autonomous wind power systems allows to increase the reliability of the operation of such installations, reduce operating costs and increase the efficiency of their operation. In emergency modes of operation, the use of magnetic transmission allows to avoid destruction or emergency shutdowns of electrical equipment. The developed simulation model of magnetic transmission takes into account the pulsations of the electromagnetic moment due to the discrete structure of the magnetic transmission and the change of the model parameters when the input moment changes: pulsations, losses in the magnetic core and permanent magnets, the change of the load angle and the transmitted electromagnetic moment. A feature of the developed model of the magnetic transmission system is that a change in the load of the electric power source leads to a change in the operating point on the mechanical characteristics of the rotor of the wind turbine. Conversely, when the wind parameters change, the output parameters of the source of electrical energy change: power, voltage, current and electromagnetic moment.

Descriptional Complexity of Finite Automata – Selected Highlights

The state complexity, respectively, nondeterministic state complexity of a regular language L is the number of states of the minimal deterministic, respectively, of a minimal nondeterministic finite automaton for L. Some of the most studied state complexity questions deal with size comparisons of nondeterministic finite automata of differing degree of ambiguity. More generally, if for a regular language we compare the size of description by a finite automaton and by a more powerful language definition mechanism, such as a context-free grammar, we encounter non-recursive trade-offs. Operational state complexity studies the state complexity of the language resulting from a regularity preserving operation as a function of the complexity of the argument languages. Determining the state complexity of combined operations is generally challenging and for general combinations of operations that include intersection and marked concatenation it is uncomputable.

Load carriage does not reduce absolute mechanical power output but reduces agility in elite military police officers

Objectives. The main objective of this study was to evaluate mean propulsive velocity (MPV), mean propulsive force (MPF) and mean propulsive power (MPP) in elite police officers under LOADED and UNLOADED conditions. The study also investigated the association of body composition and strength levels under the same load conditions. Methods. Twenty-one men from an elite unit in Brazil participated in the study, performing Smith machine half squats and an agility test. Dual energy X-ray absorptiometry measured body composition; a linear encoder measured MPV, MPF and MPP during the half squats; and a manual chronometer registered agility test performance. Results. The results showed that wearing and carrying occupational loads did not alter the squat exercise’s MPP, MPV and MPF but reduced the performance of relative MPP and agility (p < 0.05). The results also showed that MPP had a higher association with force (i.e., MPF and one-repetition maximum [1RM]) than velocity (i.e., MPV and agility) under the LOADED condition (p < 0.05). Among the body composition variables, only lean body mass was associated with MPP under the LOADED condition (p < 0.05). Conclusion. These findings suggest that load carriage does not reduce absolute mechanical power output, but reduces the relative MPP and agility in military police officers.

Primary Political Objective According to Zygmunt Bauman. The Commodification of Labour and the Commodification of Consumption in a Solid and Liquid Modernity

Using categories developed by the late Zygmunt Bauman, the article focuses on commodification in solid and liquid modernity, which he sees as the overarching goal of politics. In the first part, author discusses the mechanisms of commodification of labour in the heavy, producer phase of modernity, highlighting issues such as panoptic power and Fordist mechanisms of production. It then analyses the commodification of consumption and the individual’s treatment of himself as a commodity. It concludes by writing about the need to de-commodify social relations.