Phase System Research Articles

A modular model for reliability analysis model of PMS with multiple K/N subsystems and mixed shocks

AbstractIn this article, a modular model is proposed for the reliability modeling of phased mission systems (PMSs) with complicated system behaviors. By the modular method, the system is divided into several levels: system, subsystem, and components. At the component level, the shock effect, including self‐degradation, additional wear and damage caused by shocks, is considered and the component reliability is evaluated. Then, the reliability modeling method of the K/N system consisting of multiple K/N subsystems is proposed, by a mathematics reasoning method. The correctness of the proposed method is also verified by a Monte Carlo (MC) simulation procedure. At last, the modular method is applied at the system level, and the reliability of a practical engineering case, the attitude and orbit control system (AOCS), is evaluated for illustration. Meanwhile, the parameter sensitivity analysis is also carried out for implementation.

Optimizing the management of multiple water resources in irrigation area under uncertainty: A novel scenario-based multi-objective fuzzy-credibility constrained programming model

Effective water resources management is vital for sustainable development, healthy ecosystems, stable socio-economic, and human well-being. However, managing water resources faces challenges due to the involvement of multiple stakeholders and uncertainties in various hydrologic fluxes. This complexity makes it rare for research to simultaneously address the hidden uncertainties in both objectives and constraints. Here, we developed a scenario-based multi-objective fuzzy-credibility constrained programming approach and applied it to the water resource management system (SMOFCP-WRMS) of the Zhaokou Yellow River Diversion Irrigation Area Phase II Project (ZKID-II). This method handles uncertainties represented by scenarios and fuzzy sets, while also resolving fuzzy uncertainty parameters within the multiple objectives and constraints of the model. We solve the SMOFCP-RWMS model by integrating the Nondominated sorting genetic algorithm III (NSGA-III) and compromise programming (CP) method. The results show that: (1) An increase in constraints violation risks (credibility level from 0.5 to 1.0) results in a decrease in water resources allocation and pollutant discharge by 25.95 × 106 m3 and 207.63 tonne, respectively, accompanied by a decline in net economic income by 68.04 × 106 CNY; (2) From extraordinary dry year to normal year (design frequencies from 95 % to 50 %) leads to a reduction in water shortage by 167.07 × 106 m3. Incorporating ‘credibility levels’ and ‘design frequencies’ would be beneficial for addressing uncertainties, including fuzzy information and discrete possibilities for the future; (3) Regarding the multi-objective model solution, the combined NSGA-III and CP approach demonstrates an average increase of 1.71 % in net economic benefits and 5.91 % in total pollution discharge, along with a 6.77 % reduction in the water deficit ration compared to the traditional CP method. Although the ecological benefits decrease slightly in the compromise-optimal solutions using the combined NSGA-III and CP method, the economic and social benefits are improved compared to those from the combined NSGA-II and CP method. This study provides valuable decision-making guidance for water resources managers in irrigated areas, aiding them in balancing economic, social, and ecological benefits, and enabling the section of an optimal water resources management scheme based on acceptable risk levels under various uncertain conditions.

Quaternity method for integrated screening, separation, extraction optimization, and bioactivity evaluation of acetylcholinesterase inhibitors from Sophora flavescens Aiton.

Sophora flavescens Aiton (Fabaceae), a ubiquitous plant species in Asia, contains a wide range of pharmacologically active compounds, such as flavonoids, with potential anti-Alzheimer's disease (anti-AD) effects. The objective of the study is to develop a quaternity method for the screening, isolation, extraction optimization, and activity evaluation of acetylcholinesterase (AChE)-inhibiting compounds from S. flavescens to realize high-throughput screening of active substances in traditional Chinese medicine and to provide experimental data for the development of anti-AD drugs. With AChE as the target molecule, affinity ultrafiltration and liquid chromatography-mass spectrometry were applied to screen for potential inhibitors of the enzyme in S. flavescens. Orthogonal array experiments combined with the multi-objective Non-Dominated Sorting Genetic Algorithm III was used for the first time to optimize the process for extracting the active substances. Enzyme inhibition kinetics and molecular docking studies were performed to verify the potential anti-AD effects of the active compounds. Five AChE-inhibiting compounds were identified: kushenol I, kurarinone, sophoraflavanone G, isokurarinone, and kushenol E. These were successfully separated at purities of 72.88%, 98.55%, 96.86%, 96.74%, and 95.84%, respectively, using the n-hexane/ethyl acetate/methanol/water (4.0/5.0/4.0/5.0, v/v/v/v), n-hexane/ethyl acetate/methanol/water (5.0/5.0/6.0/4.0, v/v/v/v), and n-hexane/ethyl acetate/methanol/water (4.9/5.1/5.7/4.3, v/v/v/v) mobile phase systems. Enzyme inhibition kinetics revealed that kushenol E had the best inhibitory effect. This study elucidates the mechanism of action of five active AChE inhibitors in S. flavescens and provides a theoretical basis for the screening and development of anti-AD and other therapeutic drugs.

Inspection of wind turbine bolted connections using the ultrasonic phased array system

This study explores the inspection of bolted connections in wind turbines, specifically focusing on the application of Phased Array Ultrasonic Testing (PAUT). The research comprises four sections: Acoustoelastic Constant calibration, high tension investigation on bolts, blind tests on larger bolts, and Finite Element Analysis (FEA) verification. The methodology shows accurate results for stress while the bolt is under operative loads, and produces a clear indication of when it is above these loads and beginning to deform. PAUT emerges as a promising tool for bolt inspection, offering multiple imaging modes for simultaneous stress monitoring and defect detection. The study advocates for PAUT as a robust method to enhance wind turbine safety, longevity, and future in-situ testing.

Design of 2.5-3.3 GHz high-precision compact digital phase shifter

Abstract A 6-bit MMIC digital phase shifter, designed using a 0.5 μm GaAs pHEMT process, has been developed to enhance the search capability of phased array systems for targets. The chip structure of the phase shifter is well-designed, and the improved embedded topology of the 45° and 90° phase shifting units effectively reduces the overall insertion loss. To reduce the chip size, the phase shifting units with smaller layouts of 5.625°, 11.25°, and 22.5° are combined, greatly reducing the chip area. The results show that within the frequency range of 2.5-3.3 GHz, the input and output VSWR is less than 1.38, the insertion loss is less than 4.3 dB, the root mean square phase error of the phase shifting state is less than 1.43°, and the absolute value of the amplitude fluctuation for different states is less than 0.52 dB. The compact chip structure measures 2.45 mm×1.08 mm.

Reducing Artefacts in FRF-based Damage Detection Using Novel Mode Extraction Approach for Guided Ultrasonic Waves

Damage in thin-walled structures can be detected by guided ultrasonic wave (GUW) based structural health monitoring systems. The application of phased arrays enables the scanning of large-scale structures from a single position. However, physical wave focusing requires a lot of effort. This can be significantly reduced if frequency response functions (FRFs) are used. They enable the calculation of virtual response signals for virtual focusing on any position. Although this technique offers an energy-efficient and fast possibility of damage detection, it has the disadvantage of artefacts that occur due to the multimodal nature of GUW, as damage detection is generally designed for single-mode signals. These artefacts are often reduced by mode-selective excitation/sensing or by subtracting a baseline measurement. This work presents a concept to combine an existing FRF-based damage detection algorithm and a previously presented method for mode extraction. It enables the extraction of GUW mode components from broadband, temporally sampled, single-input single-output sensor data during signal processing on the basis of the respective dispersion relations. The aim is to reduce artefacts without using mode-selective excitation/sensing or baseline measurements. A finite element simulation of GUW propagation in an isotropic structure is used to demonstrate the advantages and limitations of this approach. The simulations include multimodal and single mode evaluation to point out the added value of performing mode extraction prior to damage detection. It is supposed that the successful extraction of the mode components from the temporally sampled data results in a decreasing amplitude of the occurring artefacts compared to the multimodal case, while the case of mode-selective excitation apparently results in no artefacts. The presented concept of adding mode extraction to damage detection algorithms can lead to an increase in performance of FRF-based phased array systems. Artefacts that would lead to false detection of damage are reduced inherently during signal processing which eliminates the need for mode-selective excitation/sensing or baseline measurements.

Development and Validation of New HPLC Method for the Determination of Imidazolidinyl Urea in Topical Formulation

Introduction: In this study, a new, simple, selective, and fast liquid chromatographic method has been developed and validated for the determination of imidazolidinyl urea used as an anti-microbial agent in topical formulation. Methods: The developed HPLC method using a diode array detector for the determination of imidazolidinyl urea was applied to the topical formulation. Imidazolidinyl urea in the sample was analyzed in the cyano column (250 x 4,6 mm, 5 μm i.d.) under chromatographic conditions, where the flow rate was determined as 1.0 mL/min. The column oven was 40.0°C, and imidazolidinyl urea was detected at 210 nm. Isocratic application of acetonitrile-water (25:75, v/v) was used as the mobile phase system. The validation of the developed method was performed according to the International Conference on Harmonisation guidelines Q2 (R1). Results: The linearity range of the imidazolidinyl urea was 0.050-0.150 mg/mL, and the limits of detection and quantification were calculated to be 62.5x10-6 mg/mL and 125x10-6 mg/mL, respectively. Assay recovery and precision of imidazolidinyl urea from topical formulation at 0.050, 0.100, and 0.125 mg/mL concentrations were evaluated. The mean recoveries for imidazolidinyl urea in the topical formulation were calculated as 98.857-104.560%. Conclusion: The validated method was successfully applied to the determination of imidazolidinyl urea in a topical formulation. The proposed method is reproducible and reliable and can be used safely for routine analysis.

Fuzzy Controller with Shunt Active Power Filter in Reducing THD for Three Phase System

Fuzzy Controller with Shunt Active Power Filter in Reducing THD for Three Phase System

Chromatographic Profiling of Ziziphus mauritiana Lam. Extracts for Phytochemical Characterization

Ziziphus mauritiana, commonly known as Chinese date, Ber, and Indian jujube, belongs to the Rhamnaceae family and is native to Southeast Asia. Although it has been naturalized in tropical regions from South Africa to the Middle East and the Indian subcontinent, its phytochemical profile remains underexplored. A comprehensive phytochemical profiling and standardization of extract can be achieved by TLC and HPLC analysis. The study involves the development of improved chromatographic methods for the analysis of local Z. mauritiana leaves, including selection of the mobile phase type, gradient elution method and temperature, which are all potential HPLC parameters that may affect the result of analysis. The leaves were subjected to extraction through maceration utilizing methanol and hexane. The results indicated a percentage yield of 7.28% for hexane and 18.98% for methanol. TLC investigations were conducted using the crude extracts obtained, employing a dual mobile phase system (ethyl acetate: chloroform = 6:4) for the methanol extract and hexane:acetone (6:4) for the hexane extract, respectively. Both systems exhibited successful separation of phytochemicals. The methanol extract was subjected to HPLC profiling in accordance with the established protocols. Naringin was determined to be present through qualitative HPLC screening. Phytochemicals present in the leaves of Z. mauritiana are identified as a result of this research, which also sheds light on the optimal parameters for TLC and HPLC analyses. This research may also provide valuable insight regarding the importance of quality control and formulation of herbal medicines from the standardized extract.

High-order allpass cascade-connected phase-system design utilizing fractional polynomial errors

ABSTRACT This paper proposes a nonlinear optimization method for designing a high-order recursive allpass digital phase system that comprises several cascade-connected second-order (SO) allpass sections. This method first splits a given phase design specification (approximation target) into a set of equal sub-specifications, and then the equal sub-specification acts as the ideal phase for each of the SO sections. Since an SO section can be designed via employing a linear programming to minimize a linear fractional error function, this splitting process generates an excellent starting point (good initial values for the coefficients of the cascaded SO sections) for further minimizing the overall approximation error. This paper first derives a wide variety of fractional polynomial error functions for designing cascade-connected allpass phase systems of different high orders, and then shows that a high-order cascade-connected allpass phase system can be designed by utilizing a nonlinear solver to minimize the peak deviation of such a fractional polynomial error. Using the derived fractional polynomial error functions in the system design enables the system designer to find an excellent starting point for further minimizing the approximation error and thus reach a convergent design solution. This paper first derives a set of fractional polynomial errors, and then adopts the eighth-order cascade-connected phase system design to exemplify the effectiveness of the fractional-polynomial-error-based design tactic. Furthermore, the stability of the cascade-connected high-order allpass system can be readily checked via confirming that all of the cascaded SO sections have their poles inside the unit circle in the complex plane.

EReaxFF force field development for BaZr0.8Y0.2O3-δ solid oxide electrolysis cells applications

The use of solid-oxide materials in electrocatalysis applications, especially in hydrogen-evolution reactions, is promising. However, further improvements are warranted to overcome the fundamental bottlenecks to enhancing the performance of solid-oxide electrolysis cells (SOECs), which is directly linked to the more-refined fundamental understanding of complex physical and chemical phenomena and mass exchanges that take place at the surfaces and in the bulk of electrocatalysis materials. Here, we developed an eReaxFF force field for barium zirconate doped with 20 mol% of yttrium, BaZr0.8Y0.2O3-δ (BZY20) to enable a systematic, large-length-scale, and longer-timescale atomistic simulation of solid-oxide electrocatalysis for hydrogen generation. All parameters for the eReaxFF were optimized to reproduce quantum-mechanical (QM) calculations on relevant condensed phase and cluster systems describing oxygen vacancies, vacancy migrations, electron localization, water adsorption, water splitting, and hydrogen generation on the surfaces of the BZY20 solid oxide. Using the developed force field, we performed both zero-voltage (excess electrons absent) and non-zero-voltage (excess electrons present) molecular dynamics simulations to observe water adsorption, water splitting, proton migration, oxygen-vacancy migrations, and eventual hydrogen-production reactions. Based on investigations offered in the present study, we conclude that the eReaxFF force field-based approach can enable computationally efficient simulations for electron conductivity, electron leakage, and other non-zero-voltage effects on the solid oxide materials using the explicit-electron concept. Moreover, we demonstrate how the eReaxFF force field-based atomistic-simulation approach can enhance our understanding of processes in SOEC applications and potentially other renewable-energy applications.

QbD green analytical procedure for the quantification of tolvaptan by utilizing stability indicating UHPLC method

For the first time a new QbD-assisted green stability indicating ultra-high-performance liquid chromatography (UHPLC) method was developed and validated for quantifying Tolvaptan. The method is simple, quick, cost-effective, and stable, and it was used to formulate a quality target product profile (QTPP) with strategically defined critical analytical attributes (CAAs) to meet specific criteria. Chromatographic separation was undertaken using a 10 cm long column of ACE excel super C18 with an interior diameter of 2.1 mm and particle size of 1.7 µm. The analysis was performed under controlled conditions at 25 ℃ with the mobile phase flowing at a rate of 0.2 mL/min and detection occurring at 220 nm. Injected 3 µL of standard by using an isocratic mobile phase system consisting of acetonitrile and water in a 95:5 v/v ratio. The diluents, prepared by mixing acetonitrile with water at a 90:10 volumetric ratio, were utilized. The analyte’s retention time was determined to be 1.63 min. The developed method provided reliable results with accuracy exceeding 99% and a correlation coefficient exceeding 0.999 ranged between 10 and 150 µg/mL across the range for LOQ—150% levels. Notably, during forced degradation testing, Tolvaptan exhibited susceptibility to acidic hydrolysis. The method effectively separated degradation products during stress testing, demonstrating its stability-indicating status. Environmental sustainability assessment of the developed method was conducted through the investigation of various indicators of Complex GAPI, Analytical Eco scale and Analytical GREEness and it was concluded the optimized method aligns with environmentally friendly practices.

Interference Study of 5G System on Civil Aircraft Airborne Beidou RDSS System in Takeoff and Landing Phase

Interference Study of 5G System on Civil Aircraft Airborne Beidou RDSS System in Takeoff and Landing Phase

Designing biodegradable aqueous biphasic systems for the selective separation of enzymes

In this work, the salting-out strength of reline eutectic mixture in aqueous solution of the non-ionic surfactant Triton X-102 has been demonstrated at temperatures between 298.15 and 323.15 K as a preliminary step to be employed in downstream operations of a biotechnological process. The phase diagrams data of reline-based Aqueous Two Phase Systems (ATPS) have been correlated using empirical models based on exponential and polynomial equations. The tie-lines have been empirically ascertained through physical properties characterization and Othmer-Tobias equation was proposed to correlate those data. After having studied the effect of the proposed reline eutectic mixture on two model enzymes (protease and lipase), the performance of this ATPS for selectively separating them was evaluated for three different feed compositions on the same tie-line, demonstrating their pertinence to segregate the lipase to one of the phases (yield about 95 %) and the protease to the other phase (yield about 98 %). These promising results are interesting for application in biotechnological reactions where proteases have been proved to be deleterious for lipases activity, as the biocompatibility of the proposed platform does not involve drastic negative effects on any of the enzymes.

Study on UPLC–MS/MS Method for Four Compositions of Cangzhu

Background The legal quality control of Cangzhu is used the single component as an evaluation indicator, which would not be enough to reflect the authenticity of quality. It is necessary to select several typical chemical components as the basis for quality control of medicinal materials and decoction pieces to reflect the content of effective ingredients. Purpose Based on UPLC-MS/MS, the study aimed to build the content determination method of atractyloidin, atractylidin A, atractylenolide I, and atractylenolide III in Cangzhu from different sources. Materials and Methods Agilent SB-C18 (2.1 × 100 µm, 1.8 µm) was used to be the stationary phase. The mobile phase system was formed by water-formic acid (1000:1) and acetonitrile-formic acid (1000:1) in gradient elution. The column temperature set at 40℃, and the flow rate was 0.3 mL min–1. Results The contents of atractyloidin, atractylidin A, atractylenolide I, and atractylenolide III had good linearity in a certain range (r2 ≥ 0. 9990). The RSD of the precision, stability and repetitive test results were less than 3.00%. In addition, the content of the four components were some different among different patches of Cangzhu. Conclusion The method was simple, rapid and highly sensitive, which was suitable for the determination of atractyloidin, atractylidin A, atractylenolide I, and atractylenolide III in Cangzhu.

One-Step Preparation Method and Rapid Detection Implementation Scheme for Simple Magnetic Tagging Materials

With the widespread application of tagging materials, existing chemical tagging materials exhibit limitations in stability and detection under field conditions. This study introduces a novel magnetic detection scheme. Hydrophilic material-modified Fe3O4 nanoparticles (COOH-PEG@Fe3O4 NPs) were synthesized using the co-precipitation technique. The content of Fe3O4 nanoparticles in the magnetic tagging liquid can reach up to 10 wt% and remain stable in an aqueous phase system for seven days. This research details the preparation process, the characterization methods (IR, 1HNMR, EDX, XRD, SEM, TEM, VSM, DLS), and the performance effects of the materials in magnetic tagging. Experimental results indicate that COOH-PEG@Fe3O4 NPs exhibit high remanence intensity (Br = 1.75 emu/g) and considerable stability, making it possible to quickly detect tagged liquids in the field using portable flux meters and optical pump magnetometers. This study provides new insights into the design and application of magnetic tagging materials, making it particularly suitable for long-term tagging and convenient detection in field scenarios.

A new approach for scale-up of pulsed disc and doughnut columns based on the similarity principle

A detailed experimental study is performed to understand the effect of scaling up on the hydrodynamic behavior of Pulsed Disc and Doughnut Columns (PDDCs) using three different systems without mass transfer. The phase system used in the experiments consists of tap water as the dispersed phase and 10% P507/kerosene with different saponification rates as the continuous phase. Dispersed phase holdup and Sauter mean diameter (d32) were measured under different operating conditions. The operating parameters that have varied are the pulsation intensity and flow rate of both liquid phases. The geometrical parameters are plate spacing spacing and column diameter. Further, the empirical correlations based on the similarity principle have been proposed to predict the dispersed phased holdup and Sauter mean diameter for a better understanding of the scale-up process.

Numerical and experimental investigations on dynamic response of twin-barge floatover system in standby phase

The twin-barge floatover installation method is an efficient method for the mega topsides installation for the offshore platform because of the large capacity and the gap-free for the substructures. This paper develops the dedicated software TBF-TJU (Twin-Barge Floatover by TJU) for dynamic response analysis of the twin-barge floatover installation system. A numerical model of the elastically-connected twin-barge floatover installation system was developed to analyze the coupled dynamic response of topsides and barges. The motion equations of the twin-barge and the topsides with consideration of the mechanical connections and the hydrodynamic interactions are derived and then solved in the time domain. The loads on mating units DSU(Deck Support Unit) in head and beam seas are numerically and experimentally investigated in detail. The numerical results are compared to the results of the corresponding tests in regular and random waves. Time-series and statistical comparisons of the motions and loads indicate that the numerical model can provide a reasonable estimation of the dynamic response of the twin barges and the topsides. The motion of the upwind barge is significantly larger than that of the leeward barge in beam sea due to the shielding effect and the hydrodynamic interactions.

Polystyrene composite system: An alternative for wastewater treatment.

Rapid population growth intensifies water scarcity, highlighting the importance of treatment technologies such as reverse osmosis and membrane filtration to ensure safe drinking water and preserve resources. The use of polystyrene as a filter for polluted water is valuable due to its porous surface, efficiently retaining impurities. The system, a tubular reactor with a mixed polystyrene bed, underwent evaluations with varying particle sizes, flow rates and times, operating in dead-end mode and series system without recirculation with theoretical residence times between 180 and 360 min. The study, divided into two phases, optimized the system in the first phase, characterizing the filter bed and carrying out maintenance for 360 min at 0.5 L/min. Phase two evaluated the performance of the reactor in treating wastewater with flow rates of 0.5 and 1 L/min for 180 min. Under the best conditions of Phase I, 55% of Escherichia coli and turbidity were deactivated, not meeting potability standards. In Phase II, there was efficiency in the removal of several parameters, such as chemical oxygen demand (78.26%), total phosphorus (75%), nitrate (73.42%), ammonia (73.13%), nitrite (69.33%), potassium (70.83%), and sodium (68.75%). In addition, 98.32% of E. coli was deactivated, meeting CONAMA Class 2 and 3 irrigation standards.

Analysis and denoising of electric noise in phased array ultrasonic testing system

Phased array ultrasonic testing (PAUT) is an advanced technique used for non-destructive testing (NDT) to detect and assess the integrity of materials or structures. In composite materials with significant acoustic attenuation, electrical noise significantly impacts PAUT detection accuracy, highlighting a crucial issue. This paper presents a comprehensive analysis of electrical noise, explains the relationship between electrical noise and inspection parameters, and proposes recommendations to reduce it. A time-varying filter empirical mode decomposition (TVF-EMD) joint wavelet thresholding method is proposed for denoising electrical noise after time-corrected gain (TCG). The ultrasonic echo signal goes through TVF-EMD decomposition, resulting in intrinsic mode functions (IMFs). Energy entropy is utilized to identify the signal-dominant IMFs, and wavelet thresholding is applied to further reduce noise within these selected IMFs. The proposed method effectively removes noise and ensures signal integrity by validating simulated and experimental signals.