Phase Angle Research Articles

An adaptive internal mass source wave-maker for short wave generation

The mass source wave-maker is commonly employed for generating water waves in numerical simulations, during which a correct amount of mass is introduced or subtracted from the internal flow region to produce target waves. The method has proven to be effective in producing waves in shallow and intermediate water depths, while its efficiency is declined for short wave generation. The main reason for this efficiency declination is that the internal mass source in deeper water region is not effective to generate short waves with their motions primarily on water surface. In order to overcome this shortcoming, many of the previous numerical treatments have introduced various enhancement factors into the source functions, which are empirically obtained and also violate the law of mass conservation. In this study, we develop a new adaptive internal wave-maker model that can be self-adjusted to suit different wave conditions. The line source starts from the bottom and extends to the computational cell right beneath free surface at each time step. The depth dependent weighting coefficient is introduced to the source function based on the linear wave theory for each wave component. No empirical coefficients are necessary, and the mass conservation is strictly and explicitly enforced. In principle, the method can be applied to all types of linear waves in the entire range of kh. The numerical experiments show that the present method can produce very good results for linear waves with kh up to 16.11, adequate for most of wave conditions in coastal engineering. For generation of fifth-order Stokes waves, the method can be extended straightforwardly for each of five wave components. For irregular waves composed of many linear wave components, different weighting coefficients can be readily calculated for each of them, respectively. As a result, the new model can generate irregular waves with overall better performance of reproducing wave spectrum, whose high-frequency part has been underestimated by previous methods. The numerical experiments also show that the new model can produce better results for focused waves where many linear waves of different frequencies start from the same point with specific phase angles, due to its capability of generating shorter wave components.

Postoperative complications in the pediatric population. Malnutrition or phase angle? Which one do we use?

Malnutrition increases post-operative risks like infections and prolonged stays. Pediatric assessment challenges require using anthropometric measurements and phase angle, which reflects body cell mass and health outcomes. Phase angle varies by maturation stages, making it crucial for pre-surgical evaluations alongside BMI. This study aimed to determine the relationship between nutritional status, phase angle, and postoperative complications in pediatric patients who underwent surgery. Prospective study with patients aged 3-17 undergoing major non-ambulatory surgery. Anthropometric measurements (weight, height, BMI Z-scores) hand grip strength, dietary intake and body composition via bioimpedance to assess phase angle were recorded. Postoperative complications were monitored, including surgical site infections, morbidity (pneumonia, inotropic support, infections, thromboembolism), and mortality. Surgical risks and pre- and postoperative conditions were documented. After the application of the selection criteria, a total of 391 patients who underwent surgery were included; 60% (n = 235) were within the range of the preschool and school-age groups. During the follow-up period, 51 (13%) patients developed at least one postoperative complication, with surgical site infections being the most common. Moreover, as phase angle decreased, the length of stay (LOS) increased in all the participants. Among children aged ≤12 years old, malnutrition was a risk factor for complications [OR 3.86 (1.61-9.27 95%CI)], whereas among adolescents, phase angle served as a protective factor [OR 0.63 (0.42-0.94 95%CI)]. Significant associations were observed between nutritional status, by BMI z-score, and post-surgical complications in younger patients. Additionally, in adolescents, the phase angle emerged as a protective factor against these complications.

Double-mixing CP violation in B decays

AbstractWe study a long-overlooked CP violation observable, termed double-mixing CP violation, which arises from the interference between two neutral meson oscillating paths involved in a decay chain. The double-mixing CP violation is beneficial for the precise test of the Standard Model CKM mechanism, as it offers the potential to extract weak phases without pollution from strong dynamics. To provide a comprehensive understanding of the double-mixing CP violation, we perform phenomenological analyses on the cascade decays of the $$B^0_d$$ B d 0 and $$B^0_s$$ B s 0 mesons. Our results show that the double-mixing CP violation can be very significant in certain decay channels, such as $$B^0_d \rightarrow J/\psi K \rightarrow J/\psi (\pi ^+\ell ^-{\bar{\nu }}_\ell )$$ B d 0 → J / ψ K → J / ψ ( π + ℓ - ν ¯ ℓ ) , where the total CP violation arises almost entirely from the double-mixing CP violation. In addition, we employ the decay process $$B^0_d \rightarrow D^0 K \rightarrow (K^-\pi ^+)(\pi \ell \nu )$$ B d 0 → D 0 K → ( K - π + ) ( π ℓ ν ) to demonstrate that the involved strong and weak phases can be directly determined from the experimental data without any theoretical inputs. Specifically, the overall weak phase of this process is $$2\beta +\gamma $$ 2 β + γ , which is of significant importance for extracting the CKM phase angles. We also use $$B^0_s \rightarrow \rho ^0 K \rightarrow \rho ^0(\pi ^-\ell ^+\nu _\ell )$$ B s 0 → ρ 0 K → ρ 0 ( π - ℓ + ν ℓ ) to illustrate and discuss the significant importance of $$K^0_S - K^0_L$$ K S 0 - K L 0 interference.

12521 Electrical Impedance Myography And Muscle Health In Older Adults With Type 1 Diabetes

Abstract Disclosure: A. Fremaint: None. G. Jung: None. E. Yu: None. M. Bouxsein: None. Introduction: Recent studies indicate that individuals with Type 1 diabetes mellitus (T1D) develop skeletal muscle health impairments which might contribute to falls and explain their high fracture risk. A novel handheld Electrical Impedance Myography (EIM) device (mScan model 1301, Myolex) has been developed to assess muscle quality by calculating tissue impedance. We hypothesized that mScan could identify individuals with worse strength and body composition outcomes among older adults with and without T1D. Methods: We studied participants of the T1D Bone Health Connection (BEACON) Study who were aged 50+ and who had undergone EIM testing (n=63 T1D, n=50 non-diabetic controls). We analyzed EIM-derived phase angle [Phase = arctan(reactance/resistance)] at 100 kHz in 3 upper extremity muscles (biceps brachii, lateral deltoid, and wrist extensors), where lower phase values indicate poorer muscle quality. Correlations of EIM data were performed with grip strength measured by a handheld dynamometer and appendicular lean mass/height2 (ALM/ht2) and visceral adipose tissue (VAT) from whole-body DXA scans. Pearson’s correlations were used for all statistical analyses. Results: Mean age (63±7 years), sex (54% female), and BMI (26.5 kg/m2) were similar between T1D and control groups. Adults with T1D had a nonsignificant trend towards lower muscle quality at the biceps brachii than controls (8.9±5.4 vs 10.9 ±6.0 degrees, p=0.078). There were no differences between groups in phase angle for lateral deltoid nor wrist extensors. Higher muscle quality at the biceps brachii was associated with higher grip strength (r=0.28, p=0.005) in the full cohort as well as in the T1D group (r=0.40, p <0.001). In the full cohort, greater VAT was associated with lower muscle health at the biceps brachii (r = -0.34, p=0.003) and lateral deltoid (r = -0.23, p<0.014), with similar patterns in both T1D and controls. There were no correlations of muscle quality with ALM/ht2. Conclusion: Our data suggest that mScan holds promise for detection of skeletal muscle health impairments in older adults, including those with T1D, potentially aiding in the diagnosis and prevention of related falls and fractures. Further research is required to investigate the association between VAT and muscle health and to validate the effectiveness of mScan in T1D and other populations. Presentation: 6/3/2024

Influence of a new controlled voltage regulator on the current and voltage non-sinusoidality of a power supply system

This work evaluates the influence of a new controlled voltage regulator on the current and voltage non-sinusoidality in different sections of a power supply system during smooth (discrete) voltage regulation on the high-voltage side of a shop transformer. The MatLab software application was used to develop a block-modular model for a transformer substation with the proposed controlled voltage regulator and measurement modules. The developed model was used to investigate the current and voltage non-sinusoidality in different parts of a power supply system when stabilizing the voltage at the consumer end at a given level. The study was carried out using a shop transformer with a capacity of 1 MV∙A and a voltage of 6/0.4 kV under an active-inductive character of the load with the load current phase angle of φ=45 deg. The obtained results confirm that, due to the extended functional capabilities of the proposed technical solution, the voltage at consumers is maintained at a given level under high technical and economic performance. When the network voltage is reduced by 5% and the activeinductive load current is increased by 35%, the proposed device was shown to create voltage non-sinusoidality. The voltage non-sinusoidality value does not exceed the permissible domestic and international norms. In addition, the proposed device is capable of maintaining the voltage at the consumer end at a given level. The obtained integral characteristic of voltage stabilization shows that the application of the proposed technical solution instead of the existing mechanical voltage regulator of the “switching without excitation” type allows the nominal voltage at the busbar of the switchgear to be retained. Further research will investigate voltage stabilization at consumers with simultaneous compensation of reactive power for complex improvement of technical and economic indicators of power supply systems under the conditions of unstable supply voltage and load current.

Enhancing the conductivity and dispersion properties of polyaniline using ethyl orange

In our research, we developed a novel one-step synthesis method for polyaniline (PANI) using the organic dye Ethyl Orange (EO). This method facilitated the formation of PANI nanorods and significantly enhanced their electrical conductivity, achieving up to 13.5 S cm−1. The structural interaction between EO and PANI was confirmed through Fourier-transform infrared (FTIR) and UV–visible (UV-Vis) spectroscopy. Notably, the inclusion of EO improved PANI's dispersion properties, resulting in a zeta potential of 34 mV in water and excellent dispersibility in various organic solvents. These attributes significantly enhance the application potential of PANI nanorods, especially in protective coatings. Electrochemical impedance spectroscopy (EIS) analysis revealed that EO-PANI/WPU coatings (0.5 wt% EO-PANI) exhibited exceptional electrochemical stability and corrosion resistance in a 3.5 wt% NaCl solution. Specifically, the initial impedance magnitude (Zf=0.01 Hz, 1010 ohms) of EO-PANI/WPU coatings was approximately two orders of magnitude higher than that of traditional WPU coatings (108 ohms). Over time, the EO-PANI coatings demonstrated higher phase angles and impedance, indicating superior electrochemical stability and protective performance.

Aeroacoustic analysis of fixed- and variable-pitch controlled multirotors and noise reduction via rotor phase control

This research conducts a comparative analysis of the aerodynamic and aeroacoustic characteristics of fixed-pitch and variable-pitch controlled multirotors (i.e., revolution per minute and collective pitch control). The study encompasses hovering and forward flight conditions, considering wind gust effects. Specifically, high-resolution time-frequency analysis is conducted to investigate the interference and modulation effects of multirotor noise. The analysis reveals significant variations in spectral characteristics depending on the control method. Notably, the frequencies of tonal noise from variable-pitch controlled multirotor do not exhibit short-periodic modulation, in contrast to those of fixed-pitch controlled multirotor. Considering the distinctive spectral characteristics of variable-pitch controlled multirotor, this study explores the effectiveness of noise reduction in variable-pitch controlled multirotor by implementing rotor phase control methods. To validate the noise reduction in time series simulations, a deep learning model is employed to determine the dynamically optimized rotor phases. A multilayer perceptron neural network was trained to derive the optimal rotor phase angles over time, considering the target observer points and flight conditions. The results demonstrate a substantial reduction in noise at the target observer points.

Prediction of energy harvesting efficiency through a wake–foil interaction model for oscillating foil arrays

This research investigates the wake–foil interactions between two oscillating foils in a tandem configuration undergoing energy harvesting kinematics. Oscillating foils have been shown to extract hydrokinetic energy from free-stream flows through a combination of periodic heave and pitch motions, at relatively higher amplitudes and lower reduced frequency than thrust generating foils. When placed in tandem, the wake–foil interactions can govern the energy harvesting efficiency of the system due to a reduced relative flow velocity in combination with a structured and coherent wake of vortices shed from the high amplitude flapping of upstream foils. This work utilizes simulations of two tandem foils to parameterize and model the energy harvesting performance as a function of array configuration and foil kinematics. Once the wake of the leading foil has been fully parameterized, the placement, phase angle and kinematic stroke of the second foil is utilized to estimate the time-dependent power curve. The algorithm predicts the power of the second foil through the mean and unsteady wake characteristics, including the direct impingement of a vortex with the trailing foil.

Analysis of the evolution process of corrosion products of pure magnesium based on the phase angle

The process of immersion corrosion on pure magnesium in 0.1 M NaCl solution was investigated by the phase angle. Results show that the peak value of phase angle and responding frequency of peak can be used to characterize the evolution process of corrosion products. It is before 80 min that corrosion products increase on the surface until film layers formed. The theoretical relation between the phase angle and corrosion products was established and the simulated results had a good agreement with the validation experiment data. Moreover, the evolution mechanism of corrosion products was studied by Scanning Vibrating Electrode Technique.

Dilational rheological properties of extended anionic surfactants at decane-water interface

The dynamic interfacial dilational properties of extended surfactants octadecyl-(polypropylene oxide)m-(polyethylene oxide)n-carboxylic sodium (C18POmEOnC) with different numbers of polypropylene oxide (PO) and polyethylene oxide (EO) groups at the decane–water interface were investigated by means of oscillating drop method. The influences of interface ageing time, dilational frequency, bulk concentration and interfacial pressure on the dilational properties were investigated. The experimental results demonstrate that, at low concentrations, the adsorption film is predominantly influenced by diffusion exchange, while intermolecular interactions at the interface play a more significant role at high concentrations. Beyond the critical micelle concentration (CMC), the primary relaxation process in the adsorption film is driven by the formation of micellar structures. Additionally, the weak hydrophobic PO groups exhibit compressibility and extensibility, facilitating the formation of spring-like helical structures at the decane–water interface. As a result, the dilational modulus increases and the phase angle decreases in low concentration with the increase of PO number. With increasing concentration, the weak hydrophilic EO chains gradually transition from a partially flat state to an upright orientation toward the aqueous phase, forming sublayer structures through polar interactions. At this stage, the increase in EO group chain length has a more pronounced impact on the elastic modulus compared to PO groups. These experimental findings suggest the existence of a mechanistic model for the extended surfactant adsorption films.

Association between phase angle and sarcopenia in patients with connective tissue diseases

Background and AimsEarly detection and management of sarcopenia in patients with connective tissue diseases (CTDs) are essential. However, the relationship between the phase angle and sarcopenia in patients with CTDs is unknown. This study investigated the association between the phase angle and sarcopenia in patients with (CTDs) and determined the optimal phase angle cutoff values for the early detection of sarcopenia. MethodsA retrospective cross-sectional study was conducted in 279 hospitalized patients with CTDs undergoing rehabilitation (median age 73.3 years; 80 men and 199 women). Bioimpedance analysis was used to measure the phase angle, and sarcopenia was assessed according to the Asian Working Group for Sarcopenia criteria. ResultsSarcopenia was identified in 134 patients (36 men and 98 women). Patients with sarcopenia had a significantly smaller phase angle than those without sarcopenia. Multivariate analysis revealed that phase angle was significantly associated with sarcopenia after adjusting for confounding factors in each sex. The optimal phase angle cutoff value for identifying sarcopenia was 4.6° for men and 4.3° for women, with area under the curve values of 0.795 and 0.754, respectively. ConclusionPhase angle is a valuable marker for identifying sarcopenia in patients with CTDs. The established phase angle cutoff values of 4.6° in men and 4.3° in women can facilitate the early detection and management of sarcopenia.

Effect of phase angle on thermohydraulic performance of an annular tube formed by co-twisted oval tubes

This study introduces a novel annular tube configuration consisting of co-twisted oval tubes with different phase angles between the inner and outer tubes. The effect of the inner tube's phase angle on the flow and heat transfer characteristics was numerically investigated over a Reynolds number range of 1000–10 000. The performance of the proposed annular tube configuration was compared with that of a conventional straight annular tube. The results indicate that the twisted oval tube induces a strong secondary flow inside the tube, which significantly enhances the heat transfer. The average Nu and f values of the annular tube with twisted oval tubes are higher than those of the conventional straight annulus. The phase angle between the inner and outer tubes significantly influences the heat transfer and comprehensive thermal performances, especially within the laminar flow region. As the phase angle increases, the average Nu increases first and then decreases. Optimal phase angles of 60° and 45° exist for Re < 6000 and Re ≥ 6000, respectively, with the largest heat transfer ability and comprehensive heat transfer performance. In comparison with a conventional straight annulus, the twisted annulus exhibits an increase in both Nu and f, with maximum enhancements of 89% and 58%, respectively. Moreover, the highest attainable thermal performance factor for the twisted annular tube was 1.66, reflecting a 66% enhancement in thermal performance compared to the conventional straight annulus.

Deformation and microregion fracture mechanisms in type 316L welded joint under isothermal and thermo-mechanical fatigue loadings

Isothermal (IF) and thermo-mechanical fatigue (TMF) tests were conducted on 316L welded joints to investigate the effects of phase angle (in-phase (IP), clockwise-diamond (CD), and out-of-phase (OP)) and mechanical strain amplitude (±0.4 %, ±0.5 %, ±0.6 %) on deformation and microregion fracture mechanisms. Results reveal that increasing strain amplitude induces a higher softening rate, reduced fatigue life, and more pronounced dynamic strain aging (DSA). Nevertheless, there is a complicated discrepancy in the cyclic deformation between various phase angles. At high strain amplitudes, local embrittlement along the austenite/δ-ferrite interface induces cracking in the weld metal (WM) under both IF and TMF loadings, with TMF life increasing with phase angle. At a lower strain amplitude of 0.4 %, however, fracture location migration and different TMF life were observed. Microstructural analysis reveals that during TMF a lower strain amplitude of 0.4 %, the microstructure in both base metal (BM) and WM evolves from simple planar structures to low-energy substructures, characterized by an increase in kernel average misorientation, geometrically necessary dislocations, and low-angle grain boundaries, together with a reduction in high-angle grain boundaries and twin boundaries. In the WM, increasing phase angle tends to reduce dislocation density and reproduces planar dislocation structures due to enhanced DSA, thereby lowering cellular structure maturity. Conversely, in the BM, dislocation proliferation and interaction intensify, enhancing cellular structure maturity and de-twinning effect, which reduces BM fracture resistance and causes fracture migration from the WM to the BM. Moreover, active DSA under CD loading improves deformation resistance in both microregions, prolonging fatigue life and contributing to the observed different TMF life.

Research on parameter deviation modelling of dual LCC wireless power transfer system

Abstract In this paper, parameter deviation modelling analysis is performed based on the dual LCC compensation network of wireless power transfer (WPT) system. Firstly, the mutual inductive coupling model of the dual LCC compensation circuit is derived based on the fundamental wave analysis method; secondly, the parameter deviation is introduced into the circuit model for the errors existing in the inductive and capacitive components of the compensation network circuit of the actual wireless charging system, and the relation between the deviation and the amplitude of the branch currents, the phase angle and the output characteristics of system are obtained through the establishment of derivation model and the resistive deviation correction term is introduced; finally, the parameter deviation is verified through the simulation. The establishment of parameter deviation model increases the accuracy of the whole circuit model and provides the theoretical basis to reduce the negative influence of parameter deviation on transmission characteristics. The value of parameter deviation can be inverted through the phase angle, thus providing a basis for adjusting the resonant state of the compensation circuit.

Acute local and non-local morphological, sensory and fluid responses to stretching and foam rolling in young females

BackgroundThis study aimed to compare and examine the local and non-local effects of a foam rolling (FR) and static stretching (SS) intervention applied to the plantar flexor (PF). MethodsFourteen female participants were investigated. Each participant underwent three conditions in a random order at least 48h apart and at the same time of the day: Control (CC), SS, and FR. Each condition was performed unilaterally in the dominant PF for 4 sets (apart from CC). SS was performed for 30 s. The FR included 30 rolls (15 in each direction) over a period of 30 s. A rest of 30 s was provided between each set for all conditions. Outcome variables were ankle dorsiflexion range of movement (ROM), tissue hardness, localized bioimpedance analysis at 50 kHz (L-BIA), and pain pressure thresholds (PPT). Tissue hardness, L-BIA, and PPT were measured in the lower leg and thigh. Measures were assessed pre (T0), immediately post (T1), and 10-min after (T2) the intervention. ResultsNo differences were found for time for the CC or between the T0 of each condition. Concerning the lower leg, ROM improved for SS and FR from T0 to T1 while returning to baseline in T2. A significant increase in PPT was observed only for SS in T1. L-BIA showed a significant increase for both phase angle and impedance only for FR in T1. Tissue hardness did not change for any group at any time-point. Concerning the thigh, no measure at any time point showed significant differences. ConclusionBoth, FR and SS were able to acutely improve ankle ROM. The observed changes were probably caused by a change in viscoelastic properties and local pain perception, without any variation in tissue morphology. FR was the only intervention to improve the intracellular-to-extracellular ratio and decrease fluids. Non-local effects were not observed.

The impact of home parenteral support on phase angle and functional mass change in palliative cancer patients with chronic intestinal failure (TYPE 3)

The impact of home parenteral support on phase angle and functional mass change in palliative cancer patients with chronic intestinal failure (TYPE 3)

Phase angle as a prognostic factor for disease-related malnutrition in hospitalised patients

Phase angle as a prognostic factor for disease-related malnutrition in hospitalised patients

Correlation between phase angle and clinical prognosis in de novo acute lymphoblastic leukemia patients

Correlation between phase angle and clinical prognosis in de novo acute lymphoblastic leukemia patients

Cardiorespiratory Fitness Predicts Improvements In Phase Angle Among Cancer Survivors

Cardiorespiratory Fitness Predicts Improvements In Phase Angle Among Cancer Survivors

Phase angle in patients with peritoneal carcinomatosis undergoing cytoreductive surgery and hyperthermic intraoperative chemotherapy

Phase angle in patients with peritoneal carcinomatosis undergoing cytoreductive surgery and hyperthermic intraoperative chemotherapy