Flagellar protein FliL: A many-splendored thing.

FliL is a bacterial flagellar protein demonstrated to associate with, and regulate ion flow through, the stator complex in a diverse array of bacterial species. FliL is also implicated in additional functions such as stabilizing the flagellar rod, modulating rotor bias, sensing the surface, and regulating gene expression. How can one protein do so many things? Its location is paramount to understanding its numerous functions. This review will look at the evidence, attempt to resolve some conflicting findings, and offer new thoughts on FliL.

Ozonation degradation of wastewater using rotational hydrodynamic cavitation reactor with a conical rotor.

Water pollution caused by an abusive discharge of dye-containing wastewater leads to serious ecological risks. Conventional wastewater treatment methods have shortcomings of incomplete degradation, long-time treatment and secondary pollution. For the first time, a rotational hydrodynamic cavitation reactor (RHCR) equipped with a conical rotor has been designed to enhance the ozonation process for effective degradation of pollutants. The effects of rotational speed, discharge voltage, gas flow rate, liquid flow rate and initial pH on methylene blue (MB) degradation were deeply investigated. The optimised conditions were initial pH = 9, rotational speed = 1800 rpm, discharge voltage = 9.3 kV, gas flow rate = 60 mL/min and liquid flow rate = 80 mL/min. With the integration of ozonation and cavitation in RHCR, the MB degradation efficiency reached 95.2%, which was 15.6% higher than that of the individual ozonation method. The degradation process was proven to track the first-order kinetic model, with the reaction rate and synergy index were 0.232 min-1 and 1.78, respectively. Through the quenching experiments, it can be confirmed that the contribution proportion of hydroxyl radical during degradation was increased by 8.7% due to the enhancement of cavitation. A required energy consumption of 74.7 kWh/order/m3 and a total expense of 8.7 $/m3 were calculated. The energy consumption of the RHCR was approximately 80% lower than that of the recently reported degradation system combining ozonation and cavitation, with total expense reduced by 52%. The findings of this work provide a new water treatment method and offered theoretical references for the design of RHCR.

A complete 3D-printed tool kit for Solid-State NMR sample and rotor handling.

Solid state NMR (SSNMR) is a highly versatile and broadly applicable method for studying the structure and dynamics of biomolecules and materials. For scientists entering the field of SSNMR, the many quotidian activities required in the workflow to prepare samples for data collection can present a significant barrier to adoption. These steps include transfer of samples into rotors, marking the reflective surfaces for high sensitivity tachometer signal detection, inserting rotors into the magic-angle spinning (MAS) stator, achieving stable spinning, and removing and storing rotors to ensure reproducibility of data collection conditions. Even experienced spectroscopists experience occasional problems with these operations, and the cumulative probability of a delay to successful data collection is high enough to cause frequent disruptions to instrument schedules, particularly in the context of large facilities serving a diverse community of users. These problems are all amplified when utilizing rotors smaller than about 4 mm in diameter. Therefore, to improve the reliability and robustness of SSNMR sample preparation workflows, here we describe a set of tools for rotor packing, unpacking, tachometer marking, extraction and storage. Stereolithography 3D printing was employed as a cost-effective and convenient method for prototyping and manufacturing a full range of designs suitable for several types of probes and rotor geometries.

Conjugated Coordination Nanosheets with Molecular Rotors for Pseudocapacitors: Nanoarchitectonics and Enhanced Performance.

High-level pseudocapacitive materials require incorporations of significant redox regions into conductive and penetrable skeletons to enable the creation of devices capable of delivering high power for extended periods. Coordination nanosheets (CNs) are appealing materials for their high natural electrical conductivities, huge explicit surface regions, and semi-one-layered adjusted pore clusters. Thus, rational design of ligands and topological networks with desired electronic structure is required for the advancement in this field. Herein, we report three novel conjugated CNs (RV-10-M, M = Zn, Ni, and Co), by utilizing the full conjugation of the terpyridine-attached flexible tetraphenylethylene (TPE) units as the molecular rotors at the center. We prepare binder-free transparent nanosheets supported on Ni-foam with outstanding pseudocapacitive properties via a hydrothermal route followed by facile exfoliation. Among three CNs, the high surface area of RV-10-Co facilitates fast transport of ions and electrons and could achieve a high specific capacity of 670.8 C/g (1677 F/g) at 1 A/g current density. Besides, the corresponding flexible RV-10-Co possesses a maximum energy density of 37.26 Wh kg-1 at a power density of 171 W kg-1 and 70% capacitance retention even after 1000 cycles.

Unsteady CFD simulation of a rotor blade under various wind conditions.

Wind and gusts can significantly impact the performance of rotors and turbines. The transient behavior of the rotor should be carefully examined to account for these effects. This paper investigates the unsteady aerodynamic characteristics of a rotor blade under different wind conditions, such as direction, speed, and angle. A 3D transient Computational Fluid Dynamics (CFD) simulation using the dynamic mesh technique is performed to analyze the rotor dynamics. The unsteady Reynolds-averaged Navier-Stokes (URANS) equations with the k-ω SST turbulence model are solved. The rotor blade used for this study is the U15XXL Combo KV29 industrial blade, which has not been numerically analyzed before. The results show that wind in the same direction as the rotation reduces the thrust more than lateral or opposite wind. Lateral wind with a speed lower than 5 m/s decreases the blade performance, but higher speeds increase it. Higher lateral wind speeds also cause two peaks in the torque curve, forming a butterfly wing shape in the polar torque plot and multiple extrema in the torque curve with increasing speed. The maximum thrust shifts slightly to the left with increasing lateral wind speed. The lateral angle does not affect the average thrust produced in one blade revolution but only causes a spatial shift. The thrust production decreases as the angle approaches the opposite direction of rotation. The motion amplitude decreases, and the curve becomes smoother as this angle increases. A nearly straight line similar to no side wind is observed at 60 and 90 degrees, which is attributed to the constant effective angle of attack during the rotation cycle.

Assessment of the effects of the use of preconsumer cotton waste on the quality of rotor yarns.

Due to the shortage of raw fiber materials and stricter legislative conditions, it has become necessary to process even the more contaminated fiber wastes that contain only a small amount of useable fibers. Hence, this paper investigates the impact of different cleaning channels on the Rieter R37 rotor spinning machine in controlling spinning strategy and yarn quality using recovered blowroom cotton waste fibers. The study involves spinning 98-tex yarns with different cleaning channels during the spinning process, using recovered blowroom cotton waste in blends with virgin cotton processed into slivers by two methods. Qualitative indicators in the fiber-sliver-yarn line were evaluated and graphically compared. The statistical significance of the influencing factors was determined using the Generalized Anova. Additionally, the quality of the experimental samples was compared to authentic data from global production using the USTER® STATISTIC. The results underline the significant influence of fiber quality, sliver preparation method and implemented cleaning channels on the arrangement of fibers in yarn structures as evidenced by structural and mechanical parameters. In particular, the comparison with USTER® STATISTICS confirms that all yarns meet the required quality standards for selected applications, including those spun exclusively from 100 % cotton waste. Furthermore, the results demonstrate that this innovative technology enables yarn manufacturers to meet customer demands, ensure optimal yarn quality and achieve cost savings by optimizing waste removal without compromising fiber yield.

Probabilistic Analysis of Critical Speed Values of a Rotating Machine as a Function of the Change of Dynamic Parameters.

Real-world rotordynamic systems exhibit inherent uncertainties in manufacturing tolerances, material properties, and operating conditions. This study presents a Monte Carlo simulation approach using MSC Adams View and Adams Insight to investigate the impact of these uncertainties on the performance of a Laval/Jeffcott rotor model. Key uncertainties in bearing damping, bearing clearance, and mass imbalance were modeled with probabilistic distributions. The Monte Carlo analysis revealed the probabilistic nature of critical speeds, vibration amplitudes, and overall system stability. The findings highlight the importance of probabilistic methods in robust rotordynamic design and provide insights for establishing manufacturing tolerances and operational limits.

Inter hospital transfers in rotor wing aircraft. Patterns and challenges. Protocol for a scoping review.

BACKGROUND: Inter-hospital transfer is necessary for the transport of patients to specialized treatment. Rotor-wing aircraft may be used in lieu of ambulances in time-critical conditions over long distances and when specialist team skills are called for. The purpose of the review is to assess the current scientific literature that describes the scenario to develop a national guideline for inter-hospital transfers using rotor-wing aircraft. The aim is to describe the patterns and challenges. METHODS AND ANALYSIS: The authors will conduct a scoping review as per Joanna Briggs Institute guideline. The protocol for the scoping review will adhere to the Open Science Framework guideline for scoping reviews and we will report the findings of the scoping review as per PRISMA-ScR guideline. We have developed the search strategy with the help of a research librarian and will conduct search in relevant electronic databases and include gray literature as well, using the PRESS and PRISMA-S guidelines. Two authors will independently screen titles and abstracts for inclusion as per eligibility criteria and conflicts will be resolved by a third reviewer. Full text retrieval will be conducted accordingly. We will analyze the extracted data using validated statistical methods. ETHICS AND DISSEMINATION: According to Danish law, scoping reviews are exempt from ethics committee approval. The findings of this scoping review will provide the scientific foundation for a national guideline on rotor-wing aircraft conveyed inter-hospital transfers in Denmark. Furthermore, we will publish the results of the scoping review in a relevant scientific journal.

Dynamics modeling and nonlinear attitude controller design for a rocket-type unmanned aerial vehicle.

This paper presents an altitude and attitude control system for a newly designed rocket-type unmanned aerial vehicle (UAV) propelled by a gimbal-based coaxial rotor system (GCRS) enabling thrust vector control (TVC). The GCRS is the only means of actuation available to control the UAV's orientation, and the flight dynamics identify the primary control difficulty as the highly nonlinear and tightly coupled control distribution problem. To address this, the study presents detailed derivations of attitude flight dynamics and a control strategy to track the desired attitude trajectory. First, a Proportional-Integral-Derivative (PID) control algorithm is developed based on the formulation of linear matrix inequality (LMI) to ensure robust stability and performance. Second, an optimization algorithm using the Levenberg-Marquardt (LM) method is introduced to solve the nonlinear inverse mapping problem between the control law and the actual actuator outputs, addressing the nonlinear coupled control input distribution problem of the GCRS. In summary, the main contribution is the proposal of a new TVC UAV system based on GCRS. The PID control algorithm and LM algorithm were designed to solve the distribution problem of the actuation model and confirm altitude and attitude tracking missions. Finally, to validate the flight properties of the rocket-type UAV and the performance of the proposed control algorithm, several numerical simulations were conducted. The results indicate that the tightly coupled control input nonlinear inverse problem was successfully solved, and the proposed control algorithm achieved effective attitude stabilization even in the presence of disturbances.

Mapping Atrial Fibrillation Drivers.

Understanding the initiating role of pulmonary veins in atrial fibrillation (AF) has led to the development of pulmonary vein isolation (PVI). The efficacy of PVI is high for paroxysmal AF, whereas it is limited for non-paroxysmal AF. This fact highlights the necessity of understanding the mechanism through which AF is maintained, to develop ablation strategies that would be required in addition to the PVI. Mapping AF in animal models and humans has led to the identification of focal or rotational drivers. New technologies have been developed to identify those AF drivers and are used as a guide for catheter ablation. This review article aims to provide a comprehensive overview of the current state of knowledge regarding AF drivers and the various mapping approaches used to identify them.

A pedigree analysis of Rotor hyperbilirubinemia combined with hepatitis B virus infection in a SLCO1B1 and SLCO1B3 gene mutations patient.

Background: Rotor syndrome (RS, OMIM#237450) is an extremely rare autosomal digenic recessive disorder characterized by mild non-hemolytic hereditary conjugated hyperbilirubinemia, caused by biallelic variation of SLCO1B1 and SLCO1B3 genes that resulted in OATP1B1/B3 dysfunction in the sinusoidal membrane leading to impaired bilirubin reuptake ability of hepatocytes. Methods: One RS pedigree was recruited and clinical features were documented. Whole genome second-generation sequencing was used to screen candidate genes and mutations, Sanger sequencing confirmed predicted mutations. Results: This study detected a homozygous nonsense variant c.1738C > T (p.R580*) in the coding region of the SLCO1B1 (NM006446) gene in a family with RS and hepatitis B virus infection by Variants analysis and Sanger sequencing, and confirmed by Copy Number Variation (CNV) analysis and Long Range PCR that there was a homozygous insertion of intron 5 of the SLCO1B3 gene into intron 5 of long-interspersed element 1 (LINE1). A few cases of such haplotypes have been reported in East Asian populations. A hepatitis B virus infection with fatty liver disease was indicated by pathology, which revealed mild-moderate lobular inflammation, moderate lobular inflammation, moderate hepatocellular steatosis, and fibrosis stage 1-2 (NAS score: 4 points/S1-2) alterations. Heterozygotes carrying p.R580* and LINE1 insertions were also detected in family members (I1, I2, III2, III3), but they did not develop conjugated hyperbilirubinemia. Conclusion: The mutations may be the molecular genetic foundation for the presence of SLCO1B1 c.1738C > T(p.R580*) and SLCO1B3 (LINE1) in this RS pedigree.

Power regulation of variable speed multi rotor wind systems using fuzzy cascaded control.

Power quality is a crucial determinant for integrating wind energy into the electrical grid. This integration necessitates compliance with certain standards and levels. This study presents cascadedfuzzy power control (CFPC) for a variable-speed multi-rotor wind turbine (MRWT) system. Fuzzy logic is a type of smart control system already recognized for its robustness, making it highly suited and reliable for generating electrical energy from the wind. Therefore, the CFPC technique is proposed in this work to control the doubly-fed induction generator (DFIG)-based MRWT system. This proposed strategy is applied to the rotor side converter of a DFIG to improve the current/power quality. The proposed control has the advantage of being model-independent, as it relies on empirical knowledge rather than the specific characteristics of the DFIG or turbine. Moreover, the proposed control system is characterized by its simplicity, high performance, robustness, and ease of application. The implementation of CFPC management for 1.5 MW DFIG-MRWT was carried out in MATLAB environment considering a variable wind speed. The obtained results were compared with the direct power control (DPC) technique based on proportional-integral (PI) controllers (DPC-PI), highlighting that the CFPC technique reduced total harmonic distortion by high ratios in the three tests performed (25%, 30.18%, and 47.22%). The proposed CFPC technique reduced the response time of reactive power in all tests by ratios estimated at 83.76%, 65.02%, and 91.42% compared to the DPC-PI strategy. Also, the active power ripples were reduced by satisfactory proportions (37.50%, 32.20%, and 38.46%) compared to the DPC-PI strategy. The steady-state error value of reactive power in the tests was low when using the CFPC technique by 86.60%, 57.33%, and 72.26%, which indicates the effectiveness and efficiency of the proposed CFPC technique in improving the characteristics of the system. Thus this control can be relied upon in the future.

Integration of Sm2Co17 Micromagnets in a Ferromagnetic Multipolar Microrotor to Enhance MEMS and Micromotor Performance.

MEMS and micromotors may benefit from the increasing complexity of rotors by integrating a larger number of magnetic dipoles. In this article, a new microassembly and bonding process to integrate multiple Sm2Co17 micromagnets in a ferromagnetic core is presented. We experimentally demonstrate the feasibility of a multipolar micrometric magnetic rotor with 11 magnetic dipoles made of N35 Sm2Co17 micromagnets (length below 250 µm and thickness of 65 µm), integrated on a ferromagnetic core. We explain the micromanufacturing methods and the multistep microassembly process. The core is manufactured on ferromagnetic alloy Fe49Co49V2 and has an external diameter of 800 µm and a thickness of 200 µm. Magnetic and geometric measurements show good geometric fitting and planarity. The manufactured microrotor also shows good agreement among the magnetic measurements and the magnetic simulations which means that there is no magnetic degradation of the permanent magnet during the manufacturing and assembly process. This technique enables new design possibilities to significantly increase the performance of micromotors or MEMS.

Effects of UAS Rotor Wash on Air Quality Measurements.

Laboratory and field tests examined the potential for unmanned aircraft system (UAS) rotor wash effects on gas and particle measurements from a biomass combustion source. Tests compared simultaneous placement of two sets of CO and CO2 gas sensors and PM2.5 instruments on a UAS body and on a vertical or horizontal extension arm beyond the rotors. For 1 Hz temporal concentration comparisons, correlations of body versus arm placement for the PM2.5 particle sensors yielded R2 = 0.85 and for both gas sensor pairs exceeded R2 of 0.90. Increasing the timestep to 10 s average concentrations throughout the burns improved the R2 value for the PM2.5 to 0.95 from 0.85. Finally, comparison of whole-test average concentrations further increased the correlations between body- and arm-mounted sensors, exceeding R2 of 0.98 for both gases and particle measurements. Evaluation of PM2.5 emission factors with single factor ANOVA analyses showed no significant differences between the values derived from the arm, either vertical or horizontal, and those from the body. These results suggest that rotor wash effects on body- and arm-mounted sensors are minimal in scenarios where short duration, time-averaged concentrations are used to calculate emission factors and whole-area flux values.

Using absorbance detection for hs-SV-AUC characterization of adeno-associated virus.

Data are presented demonstrating that absorbance detection can be used during high-speed sedimentation velocity analytical ultracentrifugation (hs-SV-AUC) experiments to characterize the size distribution of adeno-associated virus (AAV) drug products accurately. Advantages and limitations of being able to use this detector in this specific type of SV-AUC experiment are discussed.

Distance Measurement of Contra-Rotating Rotor Blades with Ultrasonic Transducers.

Coaxial rotor helicopters have great potential in civilian and commercial uses, with many advantages, but challenges remain in the accurate measurement of rotor blades' distance to prevent blade collision. In this paper, a blade tip distance measurement method based on ultrasonic measurement window and phase triggering is proposed, and the triggering time of the transmitter is studied. Due to the complexity of the measured signal, bandpass filtering and a time-of-flight (TOF) estimation based on the power density of the received signal are utilised. The method is tested on an experimental test platform with a pair of 200 kHz ultrasonic transducers. The experimental results show that the maximum ranging error is less than 1.0% for the blade tip distance in a range of 100-1000 mm. Compared with the amplitude threshold method, the proposed TOF estimation method works well on the received signal with a low SNR and improves the ranging accuracy by about 5 mm when the blade tip distance is larger than 500 mm. This study provides a good reference for the accurate measurement of rotor blade tip distance, and gives a solution for ranging high-speed rotating objects.

Nonlinear robust sliding mode - Backstepping hybrid control for WECS -theoretical design and experimental evaluation.

This paper proposes a new contribution in the field of optimizing control techniques for wind systems to enhance the quality of the energy produced in the grid. Although the Sliding Mode control technique, whether classical or involving the use of artificial intelligence, has shown interesting results, its main drawback lies in the oscillation phenomenon commonly referred to as "chattering." This phenomenon affects the accuracy and robustness of the system, as well as the parametric variation of the system. In this work, we propose a solution that combines two nonlinear techniques based on the Lyapunov theorem to eliminate the chattering phenomenon. It is a hybrid approach between the Backstepping strategy and the Sliding Mode, aiming to control the active and reactive powers of the doubly fed induction generator (DFIG) connected to the electrical grid by two converters (grid side and machine side). This hybrid technique aims to improve the performance of the wind system in terms of precision errors, stability, as well as active and reactive power. The proposed solution has been validated in the Matlab & Simulink environment to assess the performance and robustness of the proposed model, as well as experimentally validated on a test bench using the DSPACE 1104 card. The obtained results are then compared with other techniques, demonstrating a significant improvement in performance.

Geometric working volume of a satellite positive displacement machine.

This article describes a method for determining the geometric working volume of satellite positive displacement machines (pump and motor). The working mechanism of these machines is satellite mechanism consisting of two non-circular gears (rotor and curvature) and circular gears (satellites). Two variants of the satellite mechanism are presented. In the first mechanism, the rolling line of the rotor is a sinusoid "wrapped" around a circle. In the second mechanism, the rolling line of the rotor is a double sinusoid "wrapped" around a circle. A method for calculating the area of the working chamber as a function of the rotor rotation angle is presented, based on mathematical formulae of the rotor, the curvature and the satellite rolling lines. It has been shown that the second variant of the satellite mechanism is advantageously characterised by a larger difference between the maximum area of the working chamber and the minimum area of this chamber. New mathematical formulas have been proposed to calculate the area of the working chamber for any angle of rotation of the shaft (rotor) based on the maximum and minimum values of the area of this chamber. It was thus confirmed that the geometric working volume depends on the maximum and minimum area of a working chamber and on the height of the satellite mechanism. The analyses of the area of the working chamber were carried out both for the mechanism without gears (the area delimited by the rolling lines of the elements of the mechanism) and for the real mechanism with gears. Differences in the values of these fields were also detected.

Analysis and Compensation of Lorentz Force Magnetic Bearing Magnetic Flux Density Uniformity Error.

Aiming at the influence of the magnetic flux density uniformity error (MFDUE) of the Lorentz force magnetic bearing (LFMB) on the sensitivity accuracy of magnetically suspended control and sensing gyroscopes (MSCSGs) on the angular rate of a spacecraft, a high precision measurement method of the angular rate of a spacecraft based on the MFDUE compensation of LFMB is proposed. Firstly, the structure of MSCSG and the sensitivity principle of MSCSG to the spacecraft angular rate are introduced. The mechanism influencing the accuracy of MSCSG to spacecraft angular rate sensitivity is deduced based on the definition of magnetic flux density uniformity. Secondly, the 3D magnetic flux distribution of LFMB is analyzed using ANSYS. The relationship between the rotor tilt angle, tilt angular rate, and magnetic flux density is established. The induced current calculation model due to MFDUE is proposed, and the LFMB magnetic flux density error compensation is realized. Finally, the simulation results show that the estimation accuracy of the induced current by the proposed method can reach 96%, and the simulation and the experiment show that the error compensation method can improve the accuracy of MSCSG in measuring the spacecraft angular rate by 12.5%.

Influence of operating pressure on the durability of a satellite hydraulic motor supplied by rapeseed oil.

This article describes the results of a durability test of a hydraulic satellite motor supplied by rapeseed oil. The tests were carried out on a test stand in a power recuperation system. The tests of the motor were carried out at a constant shaft speed for three fixed pressure drops in the motor. This made it possible to demonstrate the influence of the motor operating pressure on the durability of the satellite mechanism. The influence of the pressure drop in the motor and the influence of the operating time on the motor absorbency, on the torque on the motor shaft and the influence on the volumetric and hydraulic-mechanical efficiency are also shown. The basic relationship between the efficiency of the motor and the temperature rise in the motor is also described. The results of the calculations of the temperature rise in the motor are compared with the experimental results. The article also shows which components of the motor's working mechanism wear out the fastest. The cause of the wear and failure is also explained.