Circular Motion Research Articles

A Randomized Comparative study of efficacy and safety between %20 and %30 Hydrogen peroxide in the Treatment of Actinic keratosis

Background and objectives: Actinic keratosis is a premalignant skin lesion that presents clinically as a sand-like macule or papule on an erythematous base with a superficial scale due to atypical proliferation of keratinocytes and may progress to squamous cell carcinoma. The aim of this study was to compare the efficacy of hydrogen peroxide in treatment of actinic keratosis between two different concentrations (%20 and %30). Methods: This is a randomized open label therapeutic trial of twenty patients with actinic keratosis has been enrolled, it was conducted from April 2022 to August 2022 at Sulaimaniah dermatology teaching center. Patients were divided to two treatment groups. Hydrogen peroxide %20 applied to the actinic lesions of group A, while group B applied 30% Hydrogen peroxide to the lesions. The solution was applied to the lesions in a circular motion for 20 seconds, for four rounds per session Patients were seen after a first session in two weeks. Maximum four sessions spaced out by 15 days are given until clearance. Result: we conducted a randomized open label therapeutic trial. It was conducted from April 2022 to August 2022 at Sulaimaniah dermatology teaching center. Regarding response in Group A out of twenty actinic lesions, marked and moderate improvement was recorded in %40, %30 of the lesions respectively while the remaining lesions %30 of them showed slight improvement and no clinically clearance has been recorded. In comparsison, Group B out of twenty lesions %60 of them clinically cleared and slight improvement was recorded only in %20 of lesions. There were statistically significant differences between (20% & 30% Hydrogen peroxide ) in response (p-value=0.000). Regarding side effects; majority of patients (85%) in both groups had recorded burning sensation, irritation and transient erythema, while no scarring, pigmentation, atrophy has been recorded. There were no statically significant differences between two groups. Conclusion: Hydrogen peroxide can be used as safe, alternative method to other modalities in treatment of actinic keratosis lesions, results would be better if higher concentration %30 used

Dynamics of JET runaway electron beams in D2-rich shattered pellet injection mitigation experiments

Abstract The publication provide further insights into the dynamics of JET runaway electron (RE) beams mitigated by D2-rich shattered pellet injection (SPI) (Reux et al 2022 Plasma Phys. Control. Fusion 64 034002). Multi-diagnostic analyses show that mechanisms causing continuous RE losses and energy transfer from hot electrons to cold background plasma can act before the SPI. After the SPI, measurements are compatible with a reduction of the maximum energy and pitch angle of the RE distribution while the population of supra-thermal electrons increases. The RE population growth is likely due to electron avalanche. Dark island-like pattern chains, characterised by an integer poloidal mode number and a certain minor radius, are identified in the JET RE beam synchrotron radiation videos. The synchrotron island dynamics is studied via a newly developed computer vision code (Sommariva and Silburn https://c4science.ch/source/pSpiPTV/). The radial motion of synchrotron island chains is found to be consistent with the most plausible time evolution of the radial current density profile compatible with both the RE synchrotron videos and the total RE current time trace. Similarly, correlations are identified between the temporal progression of the synchrotron islands poloidal rotation frequency and sudden MHD relaxation events. Loss-of-RE events probably caused by non-linear interactions between synchrotron islands are observed for the first time. Experimental evidences suggest that synchrotron islands are possibly related to the existence of magnetic islands which may lead to the development of new RE beam mitigation strategies.

QPOs and circular orbits around black holes in Chaplygin-like cold dark matter

Understanding the nature of dark energy in the universe is an actual issue in theoretical astrophysics and cosmology. One way to do it is by probing dark fluids with different equations of states (EoS). In the present work, we consider a Schwarzschild black hole (BH) surrounded by a dark fluid with a Chaplygin-like EoS as a generalized version of the Chaplygin EoS. We first investigate the effects of the dark fluid parameters on the horizon properties of the BH. The effective mass of the spacetime is calculated and analyzed under the dark fluid parameters. The scalar invariants of the BH spacetime are also calculated, and it is shown that the spacetime curvature increases as the dark fluid parameter increases. Next, we studied the circular motion of the test particle around the BH. As standard particle motion investigations, we analyze the effective potential of the particles for circular motion, specific energy, and angular corresponding to circular orbits with zero and nonvanishing values of the dark fluid intensity. In addition, we study the innermost stable circular orbits (ISCO). It is observed that there is an outermost stable circular orbit (OSCO) due to the presence of the dark fluid. It also shows that at a critical value of the dark fluid intensity parameter, ISCO and OSCO take the same radius. We calculate the frequency of Keplerian orbits and radial and vertical oscillations of the particles along stable circular orbits. We also applied orbital data from hotspots observed near Sgr A* to obtain upper and lower values for the EoS parameter. Finally, we investigate quasiperiodic oscillations and obtain the mass-to-EoS parameter relations for GRS J1915-105 and XTE 1550-564.

Medio-lateral forefoot segmentation for clinical gait analysis based on metatarsal subunit rigidity and angular motion

Medio-lateral forefoot segmentation for clinical gait analysis based on metatarsal subunit rigidity and angular motion

A Novel 3D Non-Stationary Vehicle-to-Vehicle Channel Model with Circular Arc Motions

A Novel 3D Non-Stationary Vehicle-to-Vehicle Channel Model with Circular Arc Motions

Flight Stability of Spinning Projectiles at High Angles of Attack

The flight behavior of the spin-stabilized 105 mm M1 artillery projectile, when fired with high quadrant elevation, is studied using six-degrees-of-freedom trajectory simulations and theoretical methods of stability analysis. Trajectory simulation results confirm the known effect of overstabilization at the apogee, leading to high angles of attack (AoA), drift to the left, and base-forward descent. For quadrant elevations between nose-forward and base-forward descent, a previously unknown descent mode was discovered, with projectiles performing a low-frequency coning motion at high angles of attack of 73 and 104 deg, respectively. An exhaustive theoretical description of such high-AoA limit cycles is given that overcomes the limitation to small angles of attack prevalent in traditional concepts of projectile stability. Based on a formulation of the angular motion in spherical coordinates, conditions for the existence of limit cycles are identified and stability criteria are derived using Lyapunov’s first method of linearization around equilibrium and eigenvalue analysis of the resulting Jacobian. The resulting criteria indicate that limit cycle flight is primarily governed by the Magnus moment coefficient. The method is applied to the 105 mm M1 projectile, and the coning motions observed in the trajectory simulations are accurately reproduced by the theory.

Exploring a novel feature of ellis spacetime: Insights into scalar field dynamics

We have studied neutral and charged massive particles dynamics in Ellis spacetime in the presence of the external scalar field. Focusing on the circular motion of massive particles, the impact of an external scalar field on the Innermost Stable Circular Orbit (ISCO) position is analyzed, revealing a non-linear relationship with the scalar field parameter. Perturbation techniques are employed to investigate oscillatory motion near stable orbits in the Ellis spacetime, yielding analytical expressions for radial and angular oscillations. The throat of the wormhole has been constrained by comparing theoretical and observational results for fundamental frequencies of particles from quasars. Finally, scalar and gravitational perturbations in the Ellis spacetime have been studied. It is shown that the equation for the scalar profile function is fully independent from the tensor functions and the solution can be represented in terms of the confluent Heun function. However, it has been shown that equations for the tensor profile functions strongly depend on the scalar profile functions in the Ellis spacetime and they are reduced to the Regge–Wheeler–Zerilli equation. Finally, numerical solutions to the Regge–Wheeler–Zerilli equation for the radial functions in the Ellis have been presented.

Teknik Counter Pressure Mengurangi Intensitas Nyeri Persalinan Kala I Fase Aktif

Lower back pain is a frequent symptom during pregnancy, often worsening as the pregnancy progresses. The shifting center of gravity, hormonal changes, and increased weight gain associated with pregnancy can contribute to lower back pain and discomfort. While pharmacological interventions are sometimes necessary, there is growing interest in non-pharmacological approaches that may provide relief without potential side effects. Counter pressure is a type of massage that uses your fists to apply constant pressure to the patient's spine during compression. Anti-stress information can also be applied to the lower back in a straight or circular motion. Back compression techniques can relieve back pain during labor contractions. Objective to determine the level of labor pain in the first stage of the active phase of labor in women giving birth at the Rappang Health Center in Sidrap Regency before back massage is carried out with the counter pressure technique. To find out labor pain in the first stage of the active phase of labor in women giving birth at the Rappang Health Center, Sidrap Regency, after doing back massage using a counter pressure technique. The type of research used is pseudo- or quasy-experimental research with a Two-Group Posttest Only design. The relaxation technique obtained a mean rank of 18.25, while the group that underwent counter pressure obtained a value of 6.75. So the average pain in the group that only got the relaxation technique was higher than that done with masse counter pressure with a p value (0.000) <0.05 so it can be concluded that counter pressure massage is effective in reducing pain intensity in laboring mothers. There is an influence of the Counter Pressure massage technique to reduce the intensity of labor pain during the first active phase at the Rappang Health Center, Sidrap Regency. Counter pressure could potentially be a useful technique for managing labor pain.

Efficacy Comparison of Low Level Laser Treatment with Muscle Energy Procedure Among Diabetic Patients Suffering from Frozen Shoulder

Frozen shoulder incidence in diabetic patient is twice as high as normal controls. There are various conventional as well as electrotherapies for its treatment within which low-level laser therapy versus muscle energy technique are well debated for efficacy in diabetic patients frozen shoulder. Objective: Comparative analysis of effectiveness of low-level laser therapy and muscle energy technique among diabetic patients with frozen shoulder. The study design was comparative study. The Place and Duration of Study was Department of Orthopaedic, Indus Medical College, Tando Muhammad Khan from 1st January 2023 to 30th June 2023. Methods: One hundred and twenty patients who were having diabetes mellitus (type 1 and type 2) and suffering from frozen shoulders were enrolled. The conventional therapeutic exercise included exercises like pendulum, arm overhead, finger wall ladder, twisting arm outwards, overhead pulley, cross-body reach exercises, hand behind-back exercise and outward rotation exercise. Muscle energy technique was administered in cases where restriction in shoulder flexion, as well as abduction, external rotation was observed. Results: There were 59% females and 41% males with majority being within the age group of 45-65 years. It was observed that there was a significant variance between pain scores at pretreatment and post treatment stages with highest value decrease observed in muscle energy technique group II. The ROM was least improved in control group only treated through conventional protocol. Conclusions: The Muscle energy technique is slightly more effective than low-level laser therapy technique in terms of pain, inflammation reduction and angular movements.

Photo Stress & Finite Element Analysis of Slip Yoke of Ashok Leyland Dost

We studied the simulation, experimental behaviour of slip yoke under loading condition. Slip yoke used for transmitting torque and rotation, is one of the most important components in motor vehicles. It is required to connect the other components of the drivetrain such as transmission and differential to each other. Basically, a slip yoke comprises of yoke parts, splined parts. Each component on slip yoke is exposed to torsion while they perform their functions such as angular and axial movement. Therefore, each component should be strong enough against to torsion in the design and analysis processes. In this study, experimental and simulation methods were used to design the slip yoke, investigated, and compared with each other. In the simulation studies, finite element analysis (FEA) was implemented by using three different loading conditions. photo elastic stress analysis (experimental method) is carried out. The comparative analysis of both methods is done & failure cause of slip yoke is found out.

Theoretical study on the movements of bubbles

The radial and translational motions of multiple interacting spherical bubbles are obtained using classical Newton mechanics. It is seen that bubbles not only move in straight line, but also in circular motion. The tracks of the bubbles show that the interactions among them include attractive, repulsive and dynamic equilibrium. There are three types of straight line corresponding to attraction, coexistence of attraction and repulsion and dynamic equilibrium, and two types of circular movement corresponding to attraction and dynamic equilibrium. The results can provide an explanation for cavitation chain and profile in cavitation field.

A mathematical model of the combination of lateral tilt and rotation of the vertebra

An important section of spinal biomechanics is the analysis of various types of movements in spinal segments, which are difficult to observe, and setting up experiments is quite complex. There are few articles devoted to this topic, and the methodological approaches outlined in these studies are so heterogeneous that they do not allow for a comparative analysis. In this situation, the abstract language of mathematics allows us to objectively answer the questions that arise. Aim of the study was to develop a mathematical model of a spinal segment to calculate the combination of rotation angles and lateral inclination of the vertebra, as well as to identify factors influencing these parameters. Material and methods. The developed mathematical model of the motion segment of the spine was used as the main tool for the study. The initial data for this model were the coordinates of the reference points of the vertebrae, which makes it possible to determine a number of parameters describing their complex structure. Using this model, the parameters of the combination of vertebral movement in the frontal and horizontal planes were calculated. Results and discussion. The developed model of the combination of movements in the spinal segment is adequate to the ideas about the nature of movements in the spinal segments. The coefficient of combination of lateral tilt and rotation of the vertebra for the cervical vertebrae is from 0.5 to 0.7, for the thoracic vertebrae from 0.3 to 0.5, and for the lumbar vertebrae from 0.0 to 0.1. Fluctuations in the value of this coefficient depend on the angle of inclination of the upper articular surfaces of the underlying vertebra. Reducing the size of the articular surfaces leads to a decrease in the magnitude of the angular movements of the vertebra, and their convergence leads to an increase in mobility in the spinal segments. A negative angle of inclination of the articular surfaces causes opposite rotation of the vertebra.

Academy Transaction note “matrix gains selection for three-axis magnetic attitude control of dynamically elongated satellite”

The paper proposes algorithm for angular motion control of a dynamically elongated spacecraft. The algorithm is based on the direct Lyapunov method using matrix control coefficients. The calculated mechanical torque is implemented using magnetorquers. Control parameters are selected using Floquet theory to ensure convergence to the required motion.

Hydrodynamic study of gas–liquid-solid mini-fluidization based on fluorescence PIV

The fluorescence-based tracer particle image velocimetry (fluorescence PIV) was used to obtain the flow regimes transition, bubble size and velocity, liquid and particle flow field characteristics of the 1 ∼ 3 mm GLSMFBs and 93 ∼ 195 μm glass beads. When the bed-to-particle diameter ratio increased, the bubble size and velocity distribution tended to be more concentrated. Bubble rose as straight line and S-shaped spiral trajectory. The divergence and vorticity of the flow field were preliminarily quantified. There showed a close relationship between the macroscopic hydromechanical behaviors such as bubble size and velocity and the mesoscopic behaviors such as the movement and development of vortices. The upward drag force of liquid and bubble on particles mainly affected the particle axial velocity, while the particle radial motion was mainly caused by bubble wake and surface force among particles. The results provide theoretical reference for the design and optimization of GLSMFB reactors.

A Light-Powered Self-Circling Slider on an Elliptical Track with a Liquid Crystal Elastomer Fiber.

In this paper, we propose an innovative light-powered LCE-slider system that enables continuous self-circling on an elliptical track and is comprised of a light-powered LCE string, slider, and rigid elliptical track. By formulating and solving dimensionless dynamic equations, we explain static and self-circling states, emphasizing self-circling dynamics and energy balance. Quantitative analysis reveals that the self-circling frequency of LCE-slider systems is independent of the initial tangential velocity but sensitive to light intensity, contraction coefficients, elastic coefficients, the elliptical axis ratio, and damping coefficients. Notably, elliptical motion outperforms circular motion in angular velocity and frequency, indicating greater efficiency. Reliable self-circling under constant light suggests applications in periodic motion fields, especially celestial mechanics. Additionally, the system's remarkable adaptability to a wide range of curved trajectories exemplifies its flexibility and versatility, while its energy absorption and conversion capabilities position it as a highly potential candidate for applications in robotics, construction, and transportation.

Design and Implementation of Remote Lab PID Controller Experiment Based on IoT

The education sector has increasingly embraced distance education to ensure a safe and uninterrupted learning process, especially in wars or epidemics. This paper focuses on designing and implementing a PID (Proportional-Integral-Derivative) controller experiment in remote laboratories utilizing the Internet of Things (IoT). Also, a laboratory experiment was developed using a naturally unstable system, specifically a cart-inverted pendulum. The experiments aim to enhance students' understanding of PID controller tuning within a real-world context. This system was chosen due to its dual motion characteristics, with a linear motion for the cart and a circular motion for the pendulum. Two controllers were designed and implemented for the system to enable control and feedback. Additionally, the Blynk platform was integrated into the experiment setup, allowing for real-time visualization of the system's response, control of PID parameters, and the ability to view the video stream via platforms like Skype. For remote connectivity, NodeMCU, an IoT development board, controlled the pendulum, collected system parameters, and transmitted them to the cloud through the Internet. Moreover, the sensors and the system were mathematically modeled, and their transfer functions were extracted. That allows the students to do the PID experiment theoretically and practically and compare the results. This complete setup enables local and remote access to the experiment, ensuring students can experiment regardless of their physical location. As a result of the study, designing and implementing a remote laboratory PID controller experiment utilizing IoT technology provides students with an innovative and immersive learning experience.

Energy extraction and Keplerian fundamental frequencies in the Kalb–Ramond gravity

The nonminimal coupling of the nonzero vacuum expectation value of the self-interacting antisymmetric Kalb–Ramond field with gravity leads to a power-law hairy BH having a parameter s, which encompasses the Reissner-Nordström black hole (s=1). It is obtained the axially symmetric counterpart of this hairy solution, namely, the rotating Kalb–Ramond black hole, which encompasses, as special cases, Kerr (s=0) and Kerr–Newman (s=1) black holes. With rotating Kalb–Ramond black hole metric, we study its horizon structure and motion of the test particles in the near of the equatorial plane and we determine radial motion equations which governing t and ϕ. We also explore thatthe black hole mass increasing when falling many of mass-less particles are relative to the black hole mass. We consider how the Kalb–Ramond parameters depend on increasing its mass. Furthermore, we analyze the Keplerian frequency, as well as the vertical and horizontal oscillations of basic frequencies, using a graph-based approach. The frequency charts are contingent upon the Kalb–Ramond parameters s and Γ. By consulting certain sources, ones can investigate the distinctions between KR gravity and other models.

In-situ aberration correction for Laguerre-Gaussian optical tweezers via optimization of orbit shape

We introduce a concept of aberration correction under microscopy that is based on observation of circular Brownian motion of an object driven by orbital angular momentum of a Laguerre-Gaussian (LG) beam. Following the concept, we establish an aberration-correction scheme by using a holographic optical tweezers setup equipped with a spatial light modulator that produces the LG beam as well as corrects the light wavefront. The light wavefront is modified adaptively to improve circular symmetry and uniformity of the orbit of a colloidal dielectric sphere revolving in mid-water under the irradiation of the LG beam. We reveal that the proposed scheme is sensitive to tiny phase difference of less than the accuracy of a highest-grade optical flat, 0.05λ, and is applicable to aberrations of up to the first 21 terms of the Zernike series expansion. The scheme not only improves the quality of optical tweezers but also enables to distinguish individual objective lenses assigned a common product code from difference in aberration-correction patterns. The present contribution therefore provides a useful tool for microscopy and laser fabrication in addition to the immediate application to optical trapping.

Circular motion of noncollinear spin textures in Corbino disks: Dynamics of Néel- versus Bloch-type skyrmions and skyrmioniums

Magnetic skyrmions are nanoscale magnetic whirls that can be driven by currents via spin torques. They are promising candidates for spintronic devices such as the racetrack memory, where a motion along the uniform current is typically desired. However, for spin torque nano-oscillators in Corbino disks, the goal is to achieve a circular motion, perpendicular to the radially applied current. As we show, based on analytical calculations and micromagnetic simulations, Bloch skyrmions engage in a circular motion with frequencies in the MHz range when driven by spin-orbit torques. In contrast, Néel skyrmions get stuck at the edges of the disk. Our analysis reveals that the antagonistic dynamics between Bloch- and Néel-type magnetic textures arise from their helicity. Furthermore, we find that skyrmioniums, which are topologically trivial variations of skyrmions, move even faster and allow an increase in the current density without being pushed toward the edges of the disk. When driven by spin-transfer torques instead, Bloch and Néel skyrmions no longer exhibit different dynamics. Instead, they move along a circular trajectory due to the skyrmion Hall effect caused by their topological charge. Consequently, the topologically trivial skyrmioniums inevitably become trapped at the disk edge in this scenario. To provide a comprehensive understanding, our paper also examines currents applied tangentially, further enriching our insights into skyrmion dynamics and appropriate current injection methods for skyrmion-based devices. Published by the American Physical Society 2024

Impact of human micro-movements on breathing zone and thermal plume formation

To enhance the realism and precision of indoor environment assessments and the evaluation of human health risks using computational fluid dynamics (CFD), it is crucial to accurately replicate human shape and physiological functions. This study investigates the influence of micro-movements resulting from posture control on the human breathing zone (BZ) using CFD analysis. A Computer-Simulated Person (CSP) incorporating a sophisticated nasal cavity model and multi-node thermoregulation was employed to precisely predict the microclimate around the human body, including the BZ. Two types of movements were considered to replicate micro-movements of a standing human body: angular and linear movements. The BZs were evaluated based on the Scale for Ventilation Efficiency (SVE) 4 and 5 for exhalation and inhalation modes, respectively. While the distribution of exhaled air remained generally consistent, distinct differences were observed in inhaled air distribution. In a representative case with a maximum angular velocity of 4°/s, the horizontal length increased by 12 cm, and the vertical distance of the SVE5>10 % distribution decreased by 14 cm compared to the stationary case. Linear movement, particularly in the mediolateral (ML) direction, led to a horizontal expansion of the inhaled air distribution. The findings of this study suggest that replicating human micro-movements has a minimal impact on general indoor climate analysis but significantly enhances the accuracy of predicting breathing air quality.