Phase Coefficients Research Articles

Kinetics of Fixed Bed Sorption Processes

Adsorption and ion exchange are examples of fixed-bed sorption processes that show transient behavior. This means that differential equations are needed to design them. As a result, numerical methods are commonly utilized to solve these equations. The solution frequently used in analytical methods is called the Thomas solution. Thomas gave a complete solution that adds a nonlinear equilibrium relationship that depends on second-order reaction kinetics. A computational approach was devised to solve the Thomas model. The Thomas model's validity was established by conducting three distinct sets of experiments. The first entails the adsorption of acetic acid from the air through the utilization of activated carbon. Following this, zeolite-5A adsorbs trichloroethylene (TCE) from the air. Finally, activated carbon is employed for the purpose of adsorbing o-cresol from aqueous solutions. A study was done to estimate phase equilibria and interphase mass transfer rates. To find the kinetic mass-transfer coefficient (K) for gases, the phase coefficients for mass transfer in the fluid phase ( ) and the pore phase ( ) were added together. The estimation of (K) for liquid was performed using the mass transfer coefficient for the solid phase and togather. The results suggest that the adsorption of acetic acid from air on activated carbon gives a good agreement with the Thomas model. The other sets of data demonstrate a disparity due to the underlying assumptions inherent in the Thomas model.

Modality-based attention and dual-stream multiple instance convolutional neural network for predicting microvascular invasion of hepatocellular carcinoma.

The presence of microvascular invasion (MVI) is a crucial indicator of postoperative recurrence in patients with hepatocellular carcinoma (HCC). Detecting MVI before surgery can improve personalized surgical planning and enhance patient survival. However, existing automatic diagnosis methods for MVI have certain limitations. Some methods only analyze information from a single slice and overlook the context of the entire lesion, while others require high computational resources to process the entire tumor with a three-dimension (3D) convolutional neural network (CNN), which could be challenging to train. To address these limitations, this paper proposes a modality-based attention and dual-stream multiple instance learning(MIL) CNN. In this retrospective study, 283 patients with histologically confirmed HCC who underwent surgical resection between April 2017 and September 2019 were included. Five magnetic resonance (MR) modalities including T2-weighted, arterial phase, venous phase, delay phase and apparent diffusion coefficient images were used in image acquisition of each patient. Firstly, Each two-dimension (2D) slice of HCC magnetic resonance image (MRI) was converted into an instance embedding. Secondly, modality attention module was designed to emulates the decision-making process of doctors and helped the model to focus on the important MRI sequences. Thirdly, instance embeddings of 3D scans were aggregated into a bag embedding by a dual-stream MIL aggregator, in which the critical slices were given greater consideration. The dataset was split into a training set and a testing set in a 4:1 ratio, and model performance was evaluated using five-fold cross-validation. Using the proposed method, the prediction of MVI achieved an accuracy of 76.43% and an AUC of 74.22%, significantly surpassing the performance of the baseline methods. Our modality-based attention and dual-stream MIL CNN can achieve outstanding results for MVI prediction.

CFD-PBE Simulation of Flow Dynamics and Mass Transfer in Two-Stage Countercurrent Mixer-Settler

Flow condition and mass transfer behavior of liquid–liquid extraction in a two-stage countercurrent extractor are investigated experimentally and numerically. CFD-PBE simulation is adopted to analyze the impact of operating parameters, including impeller speed, residence time, and organic-aqueous ratio of feed flow on volume fraction and droplet size of dispersed phase and volumetric mass transfer coefficient. Droplet size distribution is calculated by considering breakage and coalescence of dispersed phase. The allocation of dispersed phase between stages is found to be determined by impeller speed. Meanwhile, the allocation of dispersed phase between mixers and settlers is governed by residence time and organic-aqueous ratio of feed flow. Turbulence intensity, volume fraction, and droplet size distribution are revealed to be dominating parameters that affect the spatial nonuniform distribution of volumetric mass transfer coefficient. The mass transfer rate can be improved by increasing impeller speed in two stages. Higher residence time and organic-aqueous ratio of feed flow, however, have opposite effects on mass transfer rate in stage-1 and stage-2.

RIS-Enhanced Secure Transmission in MTC Networks With Finite Blocklength

In this paper, we propose a reconfigurable intelligent surface (RIS) assisted secure finite blocklength transmission framework in machine-type communications (MTC) networks, where the integration of millimeter-wave (mmWave) communication and non-orthogonal multiple access (NOMA) technology is considered to alleviate the problem of insufficient spectrum resources caused by massive MTC devices (MTCDs). For improving the ability of anti-eavesdropping, we aim to maximize the achievable sum secrecy capacity (SC) by jointly optimize the MTCDs’ transmission power, RIS phase coefficient and receive beamforming design. To handle the nonconvexity of the proposed optimization problem, we decouple it into three sub-problems, where the first two are solved by successive convex approximation (SCA) method. A minimum mean squared error successive interference cancellation (MMSE-SIC) scheme is proposed to tackle the receive beamforming problem for uplink NOMA networks. Furthermore, an alternating optimization based joint power, phase, and beamforming allocation (AO-JPPBA) algorithm is developed to implement joint optimization. Simulation results show that: 1) the security performance of the proposed AO-JPPBA is improved by 612.26% than the baseline scheme; 2) the proposed MMSE-SIC beamforming scheme is more effective in improving sum-SC of uplink NOMA networks; 3) RIS’s location has an obvious impact on sum-SC when considering eavesdroppers with strong wiretapping ability.

Calibration method for fringe projection profilometry based on rational function lens distortion model

The calibration of the fringe projection profilometry (FPP) system is susceptible to the camera lens distortion. This paper presents a calibration method based on the rational function lens distortion model. In this method, we integrate the rational function into the mathematical expression of the out-of-plane height to mitigate the impact of lens distortion. With arbitrarily arranged measurement components, we can flexibly measure the three-dimensional (3D) shape of objects with no expensive auxiliaries, high-precision setups, or complicated projector calibration. First, we project modulated sinusoidal fringe patterns with high frequency to the concentric circle grids calibration board to accurately estimate the unwrapped phase value, the pixel coordinate, and the out-of-plane height at each feature point. Then, the 3D coordinates can be recovered by determining the coefficients of the high order phase, coordinate, and height (PCH) mapping. Experiments on computer simulation and real data demonstrate that the modified calibration contributes to the flexibility and accuracy of the 3D shape measurement.

One-Pot, Three-Phase Recycling of Metals from Li-Ion Batteries in Rotating, Concentric-Liquid Reactors.

Efficient recycling of spent lithium-ion batteries, LIBs, is essential for making their numerous applications sustainable. Hydrometallurgy-based separation methods are an indispensable part of the recycling process but remain limited by the extraction efficiency and selectivity, and typically require numerous binary liquid-liquid extraction steps in which the capacity of the extracting organic phase or partition coefficient of extracted metals become an overall bottleneck. In this paper, we describe rotating reactors in which aqueous feed, organic extractant, and aqueous acceptor phases are all present in the same, rotating vessel and can be vigorously stirred and emulsified without the coalescence of aqueous layers. In this arrangement, the extractant molecules are not equilibrated with the feed and, instead, "shuttle" between the feed/extractant and the extractant/acceptor interfaces multiple times, with each such molecule ultimately transferring ∼10 metal ions. This shuttling allows for using extractant concentrations much lower than in previous designs even for extremely concentrated feeds and, simultaneously, ensures unprecedented speed and selectivity of the one-pot processes. These experimental results are accompanied by theoretical considerations of the selectivity versus speed trends as well as discussion of parameters essential for system's upscaling. This article is protected by copyright. All rights reserved.

Phase stability and thermophysical properties of CeO2-Re2O3 (Re[dbnd]Eu, Gd, Dy, Y, Er, Yb) co-stabilised zirconia

A series of 16 mol% CeO2-2 mol% Re2O3 co-stabilised zirconia (ZrO2) (16Ce4ReSZ, ReEu, Gd, Dy, Y, Er, Yb) ceramic materials were synthesised using a chemical coprecipitation– high-temperature roasting method. Their phase structure, high-temperature phase stability, mechanical properties, thermal conductivity and coefficient of thermal expansion (CTE) were investigated. The results show that the ZrO2 tetragonal phase co-stabilised by CeO2 and Re3+ with a smaller radius has better stability. The 16Ce4ReSZ (ReDy, Y, Er, Yb) materials have high fracture toughnesses, low thermal conductivities, and high CTE values. As the radius of the Re3+ ions decreases, the lattice energy increased, while the lattice distortion decreases, the CTE decreases slightly and the thermal conductivity of the material increases slightly. Owing to the high phase stability of 16Ce4YbSZ, its mechanical properties are best after 100 h of sintering at 1400 °C.

Ankle strategies for step-aside movement during quiet standing.

The mediolateral ankle strategy plays a crucial role in providing ankle stability in ground obstacle-avoidance behavior. This is achieved by changing basic walking patterns according to the characteristics of the obstacle. In daily life, it is more common to use step-aside movement (i.e., dodging step) for collision avoidance rather than side-stepping (i.e., widening standing base) when encountering an approaching pedestrian or bicycle. While studies have been conducted on the mediolateral ankle strategy contribution in obstacle avoidance using side-stepping, knowledge of step-aside movement is still inadequate. Therefore, we conducted an electromyography (EMG) analysis on the tibialis anterior (TA), peroneus longus (PL), and soleus (SOL) muscles, as well as measured center of pressure (CoP) displacement, and vertical ground reaction force (vGRF) of the standing leg, in order to understand the role of ankle muscles in step-aside movement during quiet standing. Fifteen healthy young men repeated twelve step-aside movements in both left and right directions. A Bayesian one-sample t-test was used to determine the sufficient step and participant counts. Multiple linear regression analysis was used to investigate the correlation between the muscle activity and CoP displacement or vGRF. The regression coefficients (β) of the left push phase and the right loading phase were tested against zero using a Bayesian one-sample t-test to identify the correlation between independent and dependent variables. We used the one-dimensional statistical parametric mapping (SPM1d) method to analyze the differences between and within the groups of EMG data based on the continuous time series. The results showed that the PL displayed a substantial contribution to the mediolateral ankle strategy during the push phase of step-aside movement, and also contributed to maintaining ankle stability during the loading phase. This suggested that screening for PL weakness and providing appropriate interventions and/or training approaches is especially critical for populations with walking stability problems.

Image-recognition-based system for precise hand function evaluation

Hand dysfunction caused by hand injuries, strokes, or other neurological degenerative diseases such as cervical spondylosis is being increasingly reported. Currently, hand function assessments for diagnosis or rehabilitation are primarily based on qualitative scales, which are subjective and may vary considerably depending on the expertise of the attending clinician. Although wearable sensors and computer vision techniques have been proposed to obtain quantitative hand movement information, both have limitations. In this study, a multiview video tracking and recording system was set up using high-speed cameras and mapping of actual hand movements. The state-of-the-art software DeepLabCut was used to obtain precise 2D and 3D finger joint positions. Kinematic parameters, such as movement count, period, phase, and Pearson coefficient were used to characterize hand movement based on the relative distance-time curves of finger joints. Experimental results in a clinical setting showed that this video-based image-recognition neural network method can accurately distinguish healthy from dysfunctional hand movements. The proposed system is inexpensive, easy to set up and use, and exhibits high accuracy. Thus, it can revolutionize medical hand motion analysis and spur the development of automated quantitative systems for early hand-related disorder detection.

Comet P/2021 HS (PANSTARRS) and the Challenge of Detecting Low-activity Comets

Jupiter-family comet (JFC) P/2021 HS (PANSTARRS) only exhibits a coma within a few weeks of its perihelion passage at 0.8 au, which is atypical for a comet. Here we present an investigation into the underlying cause using serendipitous survey detections and targeted observations. We find that the detection of the activity is caused by an extremely faint coma being enhanced by the forward scattering effect owing to the comet reaching a phase angle of ∼140°. The coma morphology is consistent with sustained, sublimation-driven activity produced by a small active area, ∼700 m2, one of the smallest values ever measured on a comet. The phase function of the nucleus shows a phase coefficient of 0.035 ± 0.002 mag deg−1, implying an absolute magnitude of H = 18.31 ± 0.04 and a phase slope of G = − 0.13, with color consistent with typical JFC nuclei. Thermal observations suggest a nucleus diameter of 0.6–1.1 km, implying an optical albedo of 0.04–0.23, which is higher than typical cometary nuclei. An unsuccessful search for dust trail and meteor activity confirms minimal dust deposit along the orbit, totaling ≲108 kg. As P/2021 HS is dynamically unstable, similar to typical JFCs, we speculate that it has an origin in the trans-Neptunian region and that its extreme depletion of volatiles is caused by a large number of previous passages to the inner solar system. The dramatic discovery of the cometary nature of P/2021 HS highlights the challenges of detecting comets with extremely low activity levels. Observations at high phase angle, where forward scattering is pronounced, will help identify such comets.

A Fast Butterfly-Compressed Hadamard–Babich Integrator for High-Frequency Helmholtz Equations in Inhomogeneous Media with Arbitrary Sources

We present a butterfly-compressed representation of the Hadamard–Babich (HB) ansatz for the Green’s function of the high-frequency Helmholtz equation in smooth inhomogeneous media. For a computational domain discretized with discretization cells, the proposed algorithm first solves and tabulates the phase and HB coefficients via eikonal and transport equations with observation points and point sources located at the Chebyshev nodes using a set of much coarser computation grids, and then butterfly compresses the resulting HB interactions from all cell centers to each other. The overall CPU time and memory requirement scale as for any bounded two-dimensional (2D) domains with arbitrary excitation sources. A direct extension of this scheme to bounded 3D domains yields an CPU complexity, which can be further reduced to quasi-linear complexities with proposed remedies. The scheme can also efficiently handle scattering problems involving inclusions in inhomogeneous media. Although the current construction of our HB integrator does not accommodate caustics, the resulting HB integrator itself can be applied to certain sources, such as concave-shaped sources, to produce caustic effects. Compared to finite-difference frequency domain methods, the proposed HB integrator is free of numerical dispersion and requires fewer discretization points per wavelength. As a result, it can solve wave propagation problems well beyond the capability of existing solvers. Remarkably, the proposed scheme can accurately model wave propagation in 2D domains with 640 wavelengths per direction and in 3D domains with 54 wavelengths per direction on a state-of-the-art supercomputer at Lawrence Berkeley National Laboratory.

Estimation Method Based on Extended Kalman Filter for Uncertain Phase Shifts in Phase-Measuring Profilometry

Phase-measuring profilometry (PMP) is increasingly applied in high-accuracy three-dimensional shape measurement. However, various factors may result in the uncertainty of phase shift values in the PMP system, and phase errors induced by actual phase shift often bring about the reconstruction failure of a measured object. A quadratic phase estimation method using the extended Kalman filter is proposed to remove the phase error introduced by uncertain phase shift. After eliminating the background and fringe modulation, the state estimation is employed to evaluate the quadratic phase coefficients in a selected mask window, and the phase shifts of adjacent fringe patterns can be estimated to compute the unwrapping phase. This paper presents a novel method for improving the accuracy of the PMP system influenced by phase shift errors, and the proposed region-wise method significantly enhances the reconstruction quality and efficiency. Experimental results show that the proposed algorithm effectively evaluates the actual phase shift and directly compensates the phase error, and has the advantages of high speed, high accuracy, and robustness.

Anomalous interaction of Pearcey Gaussian pulse in saturable nonlinear media

The dynamics of the mutual interaction of two temporally separated Pearcey Gaussian (PG) pulses in a saturable nonlinear medium is investigated. According to the temporal separation, relative phase, and saturation coefficient of the two pulses, we observed attraction or repulsion between PG pulses. The attraction leads to the generation of breathing solitons whose period increases linearly with the saturation parameter. By adjusting the pulse separation, the change of the initial interference makes the two pulses transmit without mutual interference. We also find that the repulsion makes the two pulses separate, and the interval decreases with the saturable parameter. We also investigate the impact of quadratic chirp imposed on the input pulse on the interaction dynamics. Our results reveal a novel scenario for PG pulses interaction in the nonlinear Schrödinger equation and provide an alternative mechanism to control breather soliton generation.

The Additive Value of Radiomics Features Extracted from Baseline MR Images to the Barcelona Clinic Liver Cancer (BCLC) Staging System in Predicting Transplant-Free Survival in Patients with Hepatocellular Carcinoma: A Single-Center Retrospective Analysis.

To study the additive value of radiomics features to the BCLC staging system in clustering HCC patients. A total of 266 patients with HCC were included in this retrospective study. All patients had undergone baseline MR imaging, and 95 radiomics features were extracted from 3D segmentations representative of lesions on the venous phase and apparent diffusion coefficient maps. A random forest algorithm was utilized to extract the most relevant features to transplant-free survival. The selected features were used alongside BCLC staging to construct Kaplan-Meier curves. Out of 95 extracted features, the three most relevant features were incorporated into random forest classifiers. The Integrated Brier score of the prediction error curve was 0.135, 0.072, and 0.048 for the BCLC, radiomics, and combined models, respectively. The mean area under the receiver operating curve (ROC curve) over time for the three models was 81.1%, 77.3%, and 56.2% for the combined radiomics and BCLC models, respectively. Radiomics features outperformed the BCLC staging system in determining prognosis in HCC patients. The addition of a radiomics classifier increased the classification capability of the BCLC model. Texture analysis features could be considered as possible biomarkers in predicting transplant-free survival in HCC patients.

Constrained radar waveform optimization for a cooperative radar-communication system

The coexistence of radar-sensing and communication systems research has received a surge of interest in recent times to tackle the issue of spectrum inadequacy. Designing an optimized radar waveform for a coexistence scenario has been a challenging task for accomplishing the convergence of radar-sensing and communication functionalities, without degrading the performance at either end. This paper proposes a novel global optimization-based Spatial Branch and Bound (SBnB) approach to optimize the phase coefficients of a Non-Linear Frequency Modulated (NLFM) waveform in a CRCS framework. In addition, the Modified-Power Ratio Constraint-Cramér–Rao Lower Bound (M-PRC-CRLB), a local optimization-based approach is proposed to optimize the phase coefficients of an NLFM waveform. The spectral energy distribution and auto-correlation characteristics of an NLFM waveform are comprehensively investigated for various values of polynomial order (N) and at different threshold Signal-to-Noise-Ratio (SNR) values. To compare the proposed waveform design approaches (M-PRC-CRLB, SBnB) with the existing waveform design approaches namely, Minimum Estimation Error Variance (MEEV) and PRC- CRLB, a Peak-to-Side-Lobe-Ratio (PSLR), and Integrated-Side-Lobe-Ratio (ISLR) are evaluated at various polynomial orders and threshold SNR values. Furthermore, the performance of a CRCS is assessed using the radar estimation rate and communication data rate. The simulation results reveal that the proposed optimized radar waveform design approaches provide improved performance compared to the existing radar waveform design approaches in terms of radar estimation rate. Further, the proposed global optimization-based SBnB approach achieves a comparable performance of the communication data rate. In addition, the proposed approaches accomplish enhanced spectral utilization, controlled side-lobe energy levels, reduced range-domain ambiguities, and a higher information rate in a CRCS.

CFD investigation of the complex multiphase flow of biomass gasification in industrial-scale dual fluidized bed reactor

In this work, the process of biomass steam-gasification via a dual fluidized bed with a thermal input of 8MWth is numerically modeled by applying the multiphase particle-in-cell method. This model is successfully validated with the experimental data. Based on the simulation, the results can be epitomized as: distinct fluidization regimes in gasifier and combustor reactors give rise to different flow pattern and dispersion coefficients of solid phase in both reactors. Large particle heat transfer coefficients mainly appear in the upper regions of both reactors due to violent reactions. In this industrial-scale apparatus, the time-averaged heat transfer coefficient of sand in the combustor is larger than that of gasifier sand for about 40 W/(m2·K). Relationships between key variables such as volume fraction, heat transfer coefficient, slip velocity, Reynolds number and temperature of solid phase are discussed. Particles with small volume fraction tend to possess large heat transfer coefficient and slip velocity. The results explored at the particle-level might be useful in the industrial operating regarding the biomass steam-gasification processes.

Potential Power of the Pyramidal Structure VII: Effects of Pyramid Power and Bio-Entanglement on the Circadian Rhythm of Biosensors

We have demonstrated the existence of a pyramid power and have revealed its characteristics by strictly scientific experiments using biosensors. We also revealed the existence of a Bio-Entanglement, an entangled relationship between biosensors. A parallel study of biosensors (edible cucumber slices) had also been conducted, and we found that the circadian rhythm of gas concentrations emitted from biosensors changes seasonally. The pyramid power and Bio-Entanglement did not change the number of cycles in the periodic approximation curve representing circadian rhythm. Therefore, in this paper we analyzed the influence of the pyramid power and Bio-Entanglement, i.e., their influence on the phase, amplitude, and correlation coefficient of the periodic approximation curve representing the circadian rhythm of emitted gas concentrations. The main results are as follows. 1) The pyramid power shifted the phase of the periodic approximation curve representing the circadian rhythm by 43 minutes. 2) The amplitude of the periodic approximation curve changed with the pyramid power and the Bio-Entanglement. The effect on the lower and upper sections of the biosensors stacked in two layers was different, with a tendency to increase the amplitude of the lower layer and decrease the amplitude of the upper layer. 3) The pyramid power and the Bio-Entanglement affected the correlation coefficient between gas concentration and the periodic approximation curve representing the circadian rhythm of gas concentration. The effect on the lower and upper layers of the biosensors was different, with a tendency for the lower layer correlation coefficient to be larger and the upper layer correlation coefficient to be smaller. Previously we demonstrated that the pyramid power and the Bio-Entanglement affect the ratio of gas concentration, i.e., psi index Ψ. In this paper we demonstrate for the first time that the pyramid power and the Bio-Entanglement affect time, i.e., phase difference.

СОВЕРШЕНСТВОВАНИЕ МЕТОДИКИ РАСЧЕТА ТАКТОВ И ЦИКЛОВ СВЕТОФОРНОГО РЕГУЛИРОВАНИЯ С УЧЕТОМ ОРГАНИЗАЦИИ ОТДЕЛЬНЫХ ПОЛОС ДЛЯ ДВИЖЕНИЯ ПАССАЖИРСКОГО ТРАНСПОРТА

The article discusses the problematic issues of calculating the cycles and cycles of traffic light regulation, in terms of individual lanes allocated for the movement of urban passenger transport. A methodology for studying the intensity of passenger transport traffic and the coefficients of their ghosting to passenger transport is proposed. Proposals have been developed to improve the existing methodology for calculating the cycles and cycles of traffic light regulation, through the use of phase coefficients for individual lanes intended for passenger transport.

Simultaneous Active and Passive Information Transfer for RIS-Aided MIMO Systems: Iterative Decoding and Evolution Analysis

This paper investigates the potential of reconfigurable intelligent surface (RIS) for passive information transfer in a RIS-aided multiple-input multiple-output (MIMO) system. We propose a novel simultaneous active and passive information transfer (SAPIT) scheme. In SAPIT, the transmitter (Tx) and the RIS deliver information simultaneously, where the RIS information is carried through the RIS phase shifts embedded in reflected signals. We introduce the coded modulation technique at the Tx and the RIS. The main challenge of the SAPIT scheme is to simultaneously detect the Tx signals and the RIS phase coefficients at the receiver. To address this challenge, we introduce appropriate auxiliary variables to convert the original signal model into two linear models with respect to the Tx signals and one entry-by-entry bilinear model with respect to the RIS phase coefficients. With this auxiliary signal model, we develop a message-passing-based receiver algorithm. Furthermore, we analyze the fundamental performance limit of the proposed SAPIT-MIMO transceiver. Notably, we establish the state evolution to predict the receiver performance in a large-size system. We further analyze the achievable rates of the Tx and the RIS, which provides insight into the code design for sum-rate maximization. Numerical results validate our analysis and show that the SAPIT scheme outperforms the passive beamforming counterpart in achievable sum rate of the Tx and the RIS.

СОВЕРШЕНСТВОВАНИЕ МЕТОДИКИ ПРОЕКТИРОВАНИЯ СВЕТОФОРНЫХ ОБЪЕКТОВ С УЧЕТОМ ОРГАНИЗАЦИИ ПЕШЕХОДНОГО ДВИЖЕНИЯ

The article deals with problematic issues in the existing methodology for calculating traffic light objects from the point of view of pedestrian traffic organization. New formulas have been developed that make it possible to recalculate phase coefficients more accurately for objects where pedestrians do not have time to overcome the roadway during the permitting cycle. A new al-gorithm for calculating the cycles and cycles of traffic light regulation is proposed, taking into ac-count the recalculation of phases sufficient in duration for pedestrians to pass through the carria-geway.