Mechanical Power Research Articles

SoxY gene family expansion underpins adaptation to diverse hosts and environments in symbiotic sulfide oxidizers.

Sulfur-oxidizing bacteria (SOB) have developed distinct ecological strategies to obtain reduced sulfur compounds for growth. These range from specialists that can only use a limited range of reduced sulfur compounds to generalists that can use many different forms as electron donors. Forming intimate symbioses with animal hosts is another highly successful ecological strategy for SOB, as animals, through their behavior and physiology, can enable access to sulfur compounds. Symbioses have evolved multiple times in a range of animal hosts and from several lineages of SOB. They have successfully colonized a wide range of habitats, from seagrass beds to hydrothermal vents, with varying availability of symbiont energy sources. Our extensive analyses of sulfur transformation pathways in 234 genomes of symbiotic and free-living SOB revealed widespread conservation in metabolic pathways for sulfur oxidation in symbionts from different host species and environments, raising the question of how they have adapted to such a wide range of distinct habitats. We discovered a gene family expansion of soxY in these genomes, with up to five distinct copies per genome. Symbionts harboring only the "canonical" soxY were typically ecological "specialists" that are associated with specific host subfamilies or environments (e.g., hydrothermal vents, mangroves). Conversely, symbionts with multiple divergent soxY genes formed versatile associations across diverse hosts in various marine environments. We hypothesize that expansion and diversification of the soxY gene family could be one genomic mechanism supporting the metabolic flexibility of symbiotic SOB enabling them and their hosts to thrive in a range of different and dynamic environments.IMPORTANCESulfur metabolism is thought to be one of the most ancient mechanisms for energy generation in microorganisms. A diverse range of microorganisms today rely on sulfur oxidation for their metabolism. They can be free-living, or they can live in symbiosis with animal hosts, where they power entire ecosystems in the absence of light, such as in the deep sea. In the millions of years since they evolved, sulfur-oxidizing bacteria have adopted several highly successful strategies; some are ecological "specialists," and some are "generalists," but which genetic features underpin these ecological strategies are not well understood. We discovered a gene family that has become expanded in those species that also seem to be "generalists," revealing that duplication, repurposing, and reshuffling existing genes can be a powerful mechanism driving ecological lifestyle shifts.

An investigation into the acceptability, adoption, appropriateness, feasibility, and fidelity of implementation strategies for birth companionship in Tehran: a qualitative inquiry on mitigating mistreatment of women during childbirth

BackgroundA birth companion is a powerful mechanism for preventing mistreatment during childbirth and is a key component of respectful maternity care (RMC). Despite a growing body of evidence supporting the benefits of birth companions in enhancing the quality of care and birth experience, the successful implementation of this practice continues to be a challenge, particularly in developing countries. Our aim was to investigate the acceptability, adoption, appropriateness, feasibility, and fidelity of implementation strategies for birth companions to mitigate the mistreatment of women during childbirth in Tehran.MethodsThis exploratory descriptive qualitative study was conducted between April and August 2023 at Valiasr Hospital in Tehran, Iran. Fifty-two face-to-face in-depth interviews were conducted with a purposive sample of women, birth companions, and maternity healthcare providers. Interviews were audio-recorded, transcribed verbatim, and analyzed using content analysis, with a deductive approach based on the Implementation Outcomes Framework in the MAXQDA 18.ResultsParticipants found the implemented program to be acceptable and beneficial, however the implementation team noticed that some healthcare providers were initially reluctant to support it and perceived it as an additional burden. However, its adoption has increased over time. Healthcare providers felt that the program was appropriate and feasible, and it improved satisfaction with care and the birth experience. Participants, however, highlighted several issues that need to be addressed. These include the need for training birth companions prior to entering the maternity hospital, informing women about the role of birth companions, assigning a dedicated midwife to provide training, and addressing any physical infrastructure concerns.ConclusionDespite some issues raised by the participants, the acceptability, adoption, appropriateness, feasibility, and fidelity of the implementation strategies for birth companions to mitigate the mistreatment of women during childbirth were well received. Future research should explore the sustainability of this program. The findings of this study can be used to support the implementation of birth companions in countries with comparable circumstances.

Spectral Spatial Neighborhood Attention Transformer for Hyperspectral Image Classification

Hyperspectral image (HSI) can provide rich spectral information, which can be helpful for accurate classification in many applications. However, the hyperspectral image classification task has challenges, including limited labeled data, data redundancy, data sparsity, and imbalanced class samples. Over time, various methods have been proposed to solve the above-mentioned problems. To mitigate the issue mentioned above in this paper, we present the neighborhood attention transformer with a channel-wise shift technique for hyperspectral image classification. The neighborhood attention transformer leverages the power of the attention mechanism to capture the spatial relationship between neighboring pixels and extract discriminative features. The channel-wise shift techniques empower the model to adjust the spectral characteristics of each channel adaptively, enhancing its ability to handle the spectral variations present in hyperspectral data. To validate the effectiveness of the proposed model, we conduct comprehensive experiments on the publically available dataset. The results demonstrate that our model consistently outperforms other state-of-the-art methods. The overall accuracy of the proposed model reached 99.41 % , 99.93 % , 98.35 % 99.59 % four datasets.

CO 2 Capture in Liquid Phase and Room-Temperature Release and Concentration Using Mechanical Power

CO ₂ Capture in Liquid Phase and Room-Temperature Release and Concentration Using Mechanical Power

Deep Learning-Powered Financial Product Recommendation System in Banks

With the rapid evolution of financial technology, the recommendation system for financial products, as a crucial technology to enhance user experience and reduce information search costs, is increasingly becoming the focus of the financial services sector. As market competition intensifies, the diversity of user demands, coupled with the continuous expansion of financial product types, has exposed limitations in traditional recommendation systems regarding accuracy and personalized services. Therefore, this study aims to explore the application of deep learning technology in the field of financial product recommendations, aiming to construct a more intelligent and precise financial product recommendation system. The metrics we focus on include precision, recall, and F1-score, comprehensively evaluating the effectiveness of the proposed methods. In terms of methodology, we first employ a Transformer model, leveraging its powerful self-attention mechanism to capture the complex relationships between user behavior sequences and financial product information.

Soft Sensor Technology for the Determination of Mechanical Seal Friction Power Performance

Mechanical seals ensure the internal sealing of centrifugal pumps from the surrounding environment. They are one of the most critical components in a centrifugal pump. For this reason, the condition of mechanical seals should be monitored during operation. Mechanical seal friction power is an important component of mechanical losses in centrifugal pumps and is used as an indicator of wear and therefore seal condition. The soft sensor described in this paper is based on temperature measurements at the seal and can be used for determining the frictional power performance. A major factor in determining frictional power performance is the heat transfer between the mechanical seal and the medium inside the pump. For calculating the heat transfer, the stationary temperature fields in the rings of the mechanical seal are described by transmission efficiencies. The root mean squared error was determined for steady-state operating conditions to assess the quality of the soft sensor calculation. The frictional power performance can be determined by recording the temperature at the mechanical seal mating ring and the medium. The algorithm detects when the steady-state operating conditions change but does not map the dynamic changes between the stationary operating conditions.

The development and implementation of a low-cost mechanical ventilator in a low-middle-income country during the COVID-19 pandemic: The Unisabana-HERONS

BackgroundThe COVID-19 pandemic in Latin America generated the need to develop low-cost, fast-manufacturing mechanical ventilators. The Universidad de La Sabana and the Fundacion Neumologica Colombiana designed and manufactured the Unisabana-HERONS (USH) ventilator. Here, we present the preclinical and clinical study results to evaluate its effectiveness and safety characteristics in an animal model (Yorkshire Sow) and five patients with acute respiratory failure receiving mechanical ventilatory support for 24 h. MethodsThe effectiveness and safety outcomes included maintaining arterial blood gases and pulse oximetry saturation (SpO2), respiratory pressures and volumes (during continuous monitoring) in the range of ARDS and lung-protective strategy goals, and the occurrence of barotrauma. A significance level of 0.05 was used for statistical tests. This clinical trial was registered on Clinicaltrials.gov (NCT04497623) and approved by the ethics committee. ResultsAmong patients treated with the Unisabana-HERONS, the most frequent causes of acute respiratory failure were pneumonia in 3/5 (60 %) and ARDS in 2/5 (40 %). During the treatment, the ventilatory parameters related to lung protection protocols were kept within the safety range, and vital signs and blood gas were stable. The percentage of time that the respiratory pressures or volumes were out of safety range were plateau pressure >30 cm H2O: 0.00 %; driving pressure >15 cm H2O: 0.06 %; mechanical power >15 J/min: 0.00 %; and Tidal volume >8 mL/kg: 0.00 %. There were no adverse events related to the ventilator. The usability questionnaire retrieved a median score for all items between 9 and 10 (best score: 10), indicating great ease of use. ConclusionThe Unisabana-HERONS ventilator effectively provided adequate gas exchange and maintained the ventilatory parameters in the range of lung protection strategies in humans and an animal model. Furthermore, it is straightforward to use and is a low-cost medical device.

MASSNet: Multiscale Attention for Single-Stage Ship Instance Segmentation

Maritime surveillance is essential in understanding, predicting, and ensuring the security of events in the complex marine environment. In this context, we have used instance segmentation techniques, which provides an accurate and efficient method for segmenting objects (Ships) in maritime surveillance. However, prevalent two-stage algorithms have limitations, including complex models, extended training time, and high memory consumption, making them impractical for real-world application. To address these challenges, we present an efficient solution called Multiscale Attention for Single-Stage Ship Instance Segmentation, or MASSNet. MASSNet uses the power of attention mechanisms to enhance multiscale feature extraction across various dimensions, resulting in a more refined and contextually-aware representation. This approach significantly improves segmentation accuracy and overall performance. In our extensive experiments, we evaluate the effectiveness of MASSNet on three challenging datasets: MariboatS, ShipInsSeg, and ShipSG. Our proposed model achieves mask Average Precision (mask AP) scores of 55.4%, 55.5%, and 74.1% on MariboatS, ShipInsSeg, and ShipSG datasets and outperforms other models such as YOLACT, SOLO and SOLOv2 architectures. MASSNet offers a robust and efficient solution for Ship Instance Segmentation, making significant improvement in the capabilities of maritime surveillance.

Mechanical Energy and Power: Time to Incorporate Them into Routine Monitoring of Mechanical Ventilation?

Mechanical Energy and Power: Time to Incorporate Them into Routine Monitoring of Mechanical Ventilation?

Enhanced mechanical endurance and power conversion efficiency in flexible Cu2ZnSnS4 solar cells using ZnO/Ag-Ag2O/ZnO film

Cu2ZnSnS4 (CZTS) solar cells occupy an important direction in the field of clean energy research due to their environmental friendliness, low cost, and industrial technology compatibility. The complex and variable usage environment also accelerates the development of flexible CZTS solar cells. However, the inferior flexibility of ITO films limited their development. ZnO/Ag/ZnO (ZAZ) films are potential choices for transparent conductive layers of CZTS solar cells due to their high transmittance, conductivity, and flexibility. To further enhance the photovoltaic performance and mechanical durability of ZAZ films and solar cells, Ag2O was introduced into ZAZ film by magnetron sputtering. An ultra-high average transmittance of 96.6% in 400-800nm was achieved for ZnO/Ag-Ag2O/ZnO (ZAAZ) films at Ag2O sputtering power of 40W, which was attributed to the fact that Ag2O effectively inhibited the growth of 3D islands of Ag film, and formed a more uniform Ag film. ZAAZ films offered a superior figure of merit value of 0.1041 Ω-1. The power conversion efficiency (PCE) of ZAAZ solar cells was 6.94%, higher than that of ZAZ solar cells (6.69%). Remarkably, the PCE of ZAAZ solar cells was 7.9% higher than that of ZAZ solar cells after 1,000 bending cycles. Therefore, Therefore, this approach may provide a promising way to improve the photovoltaic performance and mechanical durability of flexible solar cells.

Variable-pitch power regulation of tethered-wing systems based on robust gain-scheduling H-infinity control

In this paper, we address the power regulation of tethered-wing systems and illustrate the benefits of employing variable-pitch control to alleviate dynamic mechanical loads and power fluctuations. The proposed control scheme is based on a strategy to maximize the generated power during low-speed wind and prevent force and power overloads during the high-speed wind. To implement this strategy, we employ a tether reeling-speed controller to maintain optimal generator speed in low-speed winds, and a MIMO speed-force controller to prevent power surges in high-speed winds. Additionally, the minimization of the wing’s pitch angle activity during high-speed wind is considered as another control objective in the proposed scheme. The controllers are synthesized using H∞ method and are made robust with respect to the system’s dynamic and parametric uncertainties. The synthesis procedure is predicated on a linear parameter varying (LPV) expression of the dynamics of the system. The effectiveness of the strategy and the performance of the controllers are showcased through simulations conducted with a comprehensive 3-dimensional simulator for tethered-wing systems.

Discovering optimal kinetic pathways for self-assembly using automatic differentiation

Macromolecular complexes are often composed of diverse subunits. The self-assembly of these subunits is inherently nonequilibrium and must avoid kinetic traps to achieve high yield over feasible timescales. We show how the kinetics of self-assembly benefits from diversity in subunits because it generates an expansive parameter space that naturally improves the "expressivity" of self-assembly, much like a deeper neural network. By using automatic differentiation algorithms commonly used in deep learning, we searched the parameter spaces of mass-action kinetic models to identify classes of kinetic protocols that mimic biological solutions for productive self-assembly. Our results reveal how high-yield complexes that easily become kinetically trapped in incomplete intermediates can instead be steered by internal design of rate-constants or external and active control of subunits to efficiently assemble. Internal design of a hierarchy of subunit binding rates generates self-assembly that can robustly avoid kinetic traps for all concentrations and energetics, but it places strict constraints on selection of relative rates. External control via subunit titration is more versatile, avoiding kinetic traps for any system without requiring molecular engineering of binding rates, albeit less efficiently and robustly. We derive theoretical expressions for the timescales of kinetic traps, and we demonstrate our optimization method applies not just for design but inference, extracting intersubunit binding rates from observations of yield-vs.-time for a heterotetramer. Overall, we identify optimal kinetic protocols for self-assembly as a powerful mechanism to achieve efficient and high-yield assembly in synthetic systems whether robustness or ease of "designability" is preferred.

Investigation of the integration of an oscillating aerofoil-based energy harvester into the building roof

The increasing energy efficiency requirements have led to innovative renewable energy solutions being integrated into buildings. Several works have shown the potential of micro wind turbines on buildings. However, their implementations have been hindered by several challenges. Flow energy harvesting devices such as oscillating aerofoils provide potential, yet a literature gap exists regarding their integration into buildings. This study addresses this gap by investigating oscillating aerofoil wind energy harvesting system performance through numerical modelling. A coupled numerical model was introduced, integrating a novel computational approach using ANSYS Fluent with one degree of freedom in rotational motion. This methodology was introduced to analyze the dynamic behaviour and predict mechanical power output of the oscillating aerofoil wind energy harvesting system, which is a novel exploration in existing literature. Moreover, validation of the computational fluid dynamics model was conducted through using experimental wind tunnel data in the literature, and results demonstrated agreement between numerical and experimental results. To improve the wind energy harvesting system of a single oscillating aerofoil, it was integrated into building roof to take advantage of acceleration effects of building roof shape. The design improvement comprises of a novel wind energy harvesting system design of an oscillating aerofoil integrated into three different building roof including flat, pitched, and curved shapes to enhance energy efficiency. The numerical analysis demonstrated that integrating an oscillating NACA 0012 aerofoil into a curved roof resulted in the highest average power output. Specifically, the integration of the curved roof and the aerofoil yielded 18 watts, while the flat roof generated only 0.6 watts at a wind speed of 3 m/s. Integration into a pitched roof achieved 12 watts at 9 m/s. Comparatively, integrating the curved roof with the aerofoil increased power output by 50% compared to the pitched roof design at 9 m/s wind speed. Thus, variations in wind speed significantly impact performance. In addition, changes in wind direction from 0 to 10 degrees led to reduced efficiency and lower predicted power output. Lastly, the power spectral density for NACA 0012 integrated into the pitched and curved roof buildings revealed peaks at 5.8 Hz in 9 m/s wind speed conditions.

Optimally integrated waste heat recovery through combined emerging thermal technologies: Modelling, optimization and assessment for onboard multi-energy systems

This paper investigates waste heat (WH) valorisation on maritime vessels from a systemic perspective. It aims to demonstrate how a set of innovative waste heat recovery (WHR) technologies can synergistically work together to valorise waste heat in multiple ways. It proposes and develops a dedicated techno-economic analysis framework and model, surpassing previous literature that focused on individual technologies or specific combinations. Employing a Mixed Integer Linear Programming (MILP) approach, this study evaluates the dynamic and flexible operation of the WHR system throughout the round-trip journey of a vessel. Identifying the most profitable WHR system layout, determining the capacity of technologies, optimising the interconnections between technologies, and establishing strategic WH dispatching are all among the key objectives of the study.An average-scale vessel with a 36 MW diesel engine, is selected for this study which involves a 17-day journey with multiple stops in Northern Europe. The vessel adequately represents the complexity of onboard energy systems in terms of types and variability of demands, as well as WH availability. The proposed WHR system, which is tailored for the selected vessel, integrates three active technologies: an isobaric expansion engine (IEE) to contribute to mechanical power demand, a sorption system for providing cooling, and an advanced Organic Rankine Cycle (ORC) for trigeneration of power, heating, and cooling. All technologies are supported by the passive WHR technology of Thermal Energy Storage (TES). The results show that deployment of the optimised WHR system onboard the selected vessel enhances energy efficiency by 5 to 7.5 percentage points and reduces fuel consumption by 13%. The study also explores economic key performance indicators (KPIs), such as the Internal Rate of Return (IRR) which is found at about 15%, clearly evidencing a compelling solution to ship owners. Additionally, the discussion includes a detailed analysis of the contribution of individual technologies in covering onboard demands, as well as their synergistic interactions.This work clarifies the role, value, and benefit of WHR technologies onboard, advancing the understanding from individual WH recovery interventions to a system-level approach. This is especially valuable in practice, considering its adaptability across various vessel types within the global fleet.

Reperkusije petooktobarskih promena 2000. godine u svetlu dokumenata, memoara i svedočenja

Drawing upon documents, memoirs, testimonies, and scholarly literature, this study elucidates the dynamics underlying the October 5th alterations in 2000 within the Federal Republic of Yugoslavia and the Republic of Serbia. „The Fifth October“ refers to a sudden shift in political authority driven by compounded socio-political, economic, and societal tensions, alongside external influences. These multifaceted political and security upheavals, culminating on October 5, 2000, exhibited characteristics akin to a „colored revolution“, signifying a change in power dynamics without altering the prevailing political structure or formal power mechanisms. While temporal detachment affords a more impartial inquiry, the analysis contends with entrenched political narratives, oscillating between glorification and complete denial of the significance of October 5th.

Robust, Efficient, and Recoverable Thermocells with Zwitterion‐Boosted Hydrogel Electrolytes for Energy‐Autonomous and Wearable Sensing

The rapid growth of flexible quasi‐solid‐state thermocells (TECs) provides a fresh way forward for wearable electronics. However, their insufficient mechanical strength and power output still hinder their further applications. This work demonstrates a one‐stone‐two‐birds strategy to synergistically enhance the mechanical and thermoelectrochemical properties of the [Fe(CN)6]3−/4−‐based TECs. By introducing multiple non‐covalent interactions via betaine zwitterions, the mechanical strength of the conventional brittle gelatin hydrogel electrolytes is substantially improved from 50 to 440 kPa, with a high stretchability approaching 250%. Meanwhile, the betaine zwitterions strongly affect the solvation structure of [Fe(CN)6]3− ions, thus enlarging the entropy difference and raising the thermoelectrochemical Seebeck coefficient from 1.47 to 2.2 mV K−1. The resultant quasi‐solid‐state TECs exhibit a superior normalized output power density of 0.48 mW m−2 K−2, showing a notable improvement in overall performance compared to their counterparts without zwitterion regulation. In addition, the intrinsic thermo‐reversible property allows the TECs to repeatedly self‐recover through sol‐gel transformations, ensuring reliable energy output and even recycling of TECs in case of extreme mechanical damages. An energy‐autonomous smart glove consisting of eighteen individual TECs is further designed, which can simultaneously monitor the temperature of different positions of any touched object, demonstrating high potential in wearable applications.

Robust, Efficient, and Recoverable Thermocells with Zwitterion-Boosted Hydrogel Electrolytes for Energy-Autonomous and Wearable Sensing.

The rapid growth of flexible quasi-solid-state thermocells (TECs) provides a fresh way forward for wearable electronics. However, their insufficient mechanical strength and power output still hinder their further applications. This work demonstrates a one-stone-two-birds strategy to synergistically enhance the mechanical and thermoelectrochemical properties of the [Fe(CN)6]3-/4--based TECs. By introducing multiple non-covalent interactions via betaine zwitterions, the mechanical strength of the conventional brittle gelatin hydrogel electrolytes is substantially improved from 50 to 440 kPa, with a high stretchability approaching 250%. Meanwhile, the betaine zwitterions strongly affect the solvation structure of [Fe(CN)6]3- ions, thus enlarging the entropy difference and raising the thermoelectrochemical Seebeck coefficient from 1.47 to 2.2 mV K-1. The resultant quasi-solid-state TECs exhibit a superior normalized output power density of 0.48 mW m-2 K-2, showing a notable improvement in overall performance compared to their counterparts without zwitterion regulation. In addition, the intrinsic thermo-reversible property allows the TECs to repeatedly self-recover through sol-gel transformations, ensuring reliable energy output and even recycling of TECs in case of extreme mechanical damages. An energy-autonomous smart glove consisting of eighteen individual TECs is further designed, which can simultaneously monitor the temperature of different positions of any touched object, demonstrating high potential in wearable applications.

Historical trajectory, logic of change and dynamics of the regulatory system for ground floor stalls--Based on a historical institutionalist perspective

The regulatory system of street stalls is an important part of China's street governance system, which plays a pivotal role in the country's economic development and social stability. Based on the analytical framework of historical institutionalism, by analyzing the historical trajectory of the change of China's street stall regulatory system, it is found that it presents a double logic of change in terms of the mode and process of change, and that its power mechanism consists of the synergistic interactions among stakeholders, social values, the institutional environment, and the institutional system. Reflecting on the past and looking forward to the future, in order to promote the long-term sustainable development of the stall regulation system and make it enter a virtuous cycle of institutional change, it is necessary to further strengthen the concept of people-oriented management, innovate the management mechanism, and promote the combination of stall regulation and artificial intelligence.

Relating ciliary propulsion morphology and flow to particle acquisition in marine planktonic ciliates I: the tintinnid ciliate Amphorides quadrilineata

Abstract The marine tintinnid ciliate Amphorides quadrilineata is a feeding-current feeder, creating flows for particle encounter, capture and rejection. Individual-level behaviors were observed using high-speed, high-magnification digital imaging. Cells beat their cilia backward to swim forward, simultaneously generating a feeding current that brings in particles. These particles are then individually captured through localized ciliary reversals. When swimming backward, cells beat their cilia forward (=ciliary reversals involving the entire ring of cilia), actively rejecting unwanted particles. Cells achieve path-averaged speeds averaging 3–4 total lengths per second. Both micro-particle image velocimetry and computational fluid dynamics were employed to characterize the cell-scale flows. Forward swimming generates a feeding current, a saddle flow vector field in front of the cell, whereas backward swimming creates an inverse saddle flow vector field behind the cell; these ciliary flows facilitate particle encounter, capture and rejection. The model-tintinnid with a full-length lorica achieves an encounter rate Q ~29% higher than that without a lorica, albeit at a ~142% increase in mechanical power and a decrease in quasi-propulsive efficiency (~0.24 vs. ~ 0.38). It is also suggested that Q can be approximated by π(W/2 + l)2U, where W, l and U represent the lorica oral diameter, ciliary length and swimming speed, respectively.

Investigations on the performance of bottle blade overshot water wheel in very low head resources for pico hydropower

Abstract An overshot water wheel is considered as a low-cost and simple alternative for rural electrification. Hence, the aim of this study is to develop a noncomplex geometrical design of an overshot water wheel, namely, bottle blade overshot water wheel (BOWW), yet effectively operated for pico hydropower generation. The BOWW and hydro system were assessed at very low water head conditions, namely, 0.3, 0.4, and 0.5 m water head using a water test rig. According to the experimental results, the BOWW equipped with eight blades when operated at 0.5 m head produced significant mechanical power and electrical power up to 48.58 and 15.55 W. Analytically, the turbine with eight blades has 26.8–49.1% efficiency. Meanwhile, the effectiveness of four blades is between 5.66 and 28.96%. The results showed that eight blades performed well. Finally, it proves that, with a very low water head and low flow rate, the proposed system can perform and produce a significant power output for power generation.