Phase Characteristics Research Articles

Determination of parameters of radio emission sources

An important task requiring additional research is the analysis of algorithms for determining the carrier frequencies of broadband signals of various durations, allowing for a short pulse duration to reliably determine the parameters of the input signal with positive signal-to-noise ratios. The search for optimal ways to determine the parameters of radio emission sources with minimal input data under operating conditions as part of on-board radio monitoring systems. Methods for determining the frequency and phase characteristics of broadband and narrowband signals with a minimum signal duration (up to 1 microsecond) are presented. A modification of the guiding cosine algorithm has been developed to optimize the resources of the signal processing system. The proposed algorithms make it possible to reduce the amount of computing device resources used. The total computational complexity of the algorithms is relatively low, and the amount of memory used is acceptable for loading into computing nodes from on-board equipment. This work was supported by the Ministry of Science and Higher Education within the State assignment № 075-00701-24-07.

Orangish-red light emitting LaSr2AlO5:Sm3+ nanophosphors for warm LEDs: Crystallographic, photoluminescence characteristics with high color purity and thermal stability

Gel-combustion method was implemented in current research to generate Strontium Lanthanum Aluminate (LaSr2AlO5) phosphors doped with Sm3+ ions and have a potential to emit orangish-red light. In order to analyze phase characteristics, XRD technique was employed. XRD patterns of synthesized materials were closely resembles the JCPDS pattern indicated on card no. 70–2197, which define the tetragonal symmetry of the material with I4/mcm space group. The morphological, optical band energies and elemental analyses were done via TEM, DRS and EDX investigation respectively. The Sm3+ activated LaSr2AlO5 phosphor's PL spectra monitored at 406 nm excitation indicate intense visible orangish-red emission at 602 nm owing to the 4G5/2 → 6H7/2 transition. Concentration quenching was obtained at 4 mol % content of Sm3+ owed to the dipole-dipole interaction among activated ions. The calculated lifetimes have been observed to shorten as content of Sm3+ ions in the phosphors rises. The CIE (0.6069, 0.3905) value, CCT (1382 K) value, 99.4 % color purity of the optimum sample was calculated which placed in orange-red space. The fabricated phosphor has excellent thermal durability up to 498 K and 0.1686 eV activation energy. Finally, the results of all the research allow us to consider that Sm3+ doped LaSr2AlO5 phosphor is appropriate for warm LEDs.

Detection of uterine cancer biomarker EGFR through an aptasensor utilizing a carbon electrode modified with silver nanowires

Treatment options and survival chances are enhanced with early detection of uterine cancer. In this work, an electrochemical paper analytical device (ePAD) for detecting Epidermal growth factor receptor (EGFR), a biomarker for uterine cancer, was demonstrated. The objective of this study is to develop a rapid nano-biosensing method for early detection of fatal uterine cancer. The proposed ePAD is inexpensive, disposable, easy, and repeatable, among other advantageous qualities. The ePAD's Working electrode comprises of silver nanowires. In addition, the use of aptamers has enhanced the performance of the biosensor. The silver nanowires' morphological, optical, elemental content, and phase characteristics were assessed by employing several analytical techniques: transmission electron microscopy (TEM), Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV–vis spectroscopy. This aptamer-modified ePAD assists in amplifying the signal of the developed platform to identify EGFR. The biosensor utilized the voltametric detection of EGFR in a solution of 0.5 mM potassium ferro/ferri cyanide, which acts as a redox pair by applying a potential of 50 mV/s at the working electrode yielded the highest performance. The designed sensor demonstrated an optimum response broad linearity of 0.01 ng/ml – 1 μg/ml for EGFR, with limit of detection (LOD) of 0.01ng/ml.

CO2-induced micro-mechanical alterations of mudstone Caprock: Examples from the Mercia Mudstone Group, East Irish Sea Basin

Mechanical properties of caprock are important for subsurface energy sequestration as they determine the rock stability under the influence of external forces. Despite some advantages, there is a lack of knowledge regarding the interplay between rock texture and mechanical properties and their impact on the caprock stability within a short-term fluid-rock reaction period. Typical caprock samples from the Mercia Mudstone Group in the East Irish Sea Basin are studied in this work. X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) were used to identify minerology and local heterogeneity characteristics. Nanoindentation tests were conducted before and after CO2-brine-rock reaction to investigate the changes of micro-mechanical properties. After CO2-brine treatment, significant dolomite dissolution was observed in all samples (although dolomite content was only minor in some samples). In contrast, the micro-texture of other minerals showed no significant changes indicating minimal to no dissolution at the current resolution. The changes of mechanical properties are lower than expected, which are probably related to the impaired cementation induced by the retained water in pore throats and relatively rough surface after reaction. For long-term carbon sequestration, the layered depositional characteristics of different phases may not only form a barrier to prevent fluids leaking upward, but also complement each other in mechanical properties to maintain stability. This study improves the understanding of the effect of microscale structural and micro-mechanical changes on caprock stability in carbon sequestration related applications.

Tailoring nano-heterogeneity to enhance magnetostriction in Goss grain-oriented Fe81Ga19 alloy thin sheets by aging treatment

The magnetostriction of Fe–Ga thin sheets can be significantly improved by secondary recrystallization, but the effect of the nano-heterogeneity on the magnetostriction of Fe–Ga thin sheets with preferred texture is still an open question. This paper studies the feasibility of tailoring nano-heterogeneity to enhance the magnetostriction of <001>-oriented Fe–Ga thin sheets by aging treatment. The secondary recrystallization of Goss ({110}<001>) texture with magnetostriction of 220 ± 12 ppm is achieved in Fe81Ga19 thin sheets after annealing at 950 °C. The magnetostriction and magnetic properties exhibit nonlinear changes with the increase of aging temperature. A peak magnetostriction of 244 ± 5 ppm is obtained in Fe81Ga19 thin sheets after aging at 450 °C, about 11% more than that of Fe–Ga thin sheets after secondary recrystallization. The effect of aging treatment on the magnetostriction of Fe–Ga thin sheets depends on the characteristics of the nano-scale L60 phase and causes lattice distortion. The increase of the volume fraction of the nano-scale L60 phase at the aging temperature of 450 °C leads to a much larger distortion and enhancement of the magnetostriction. As the aging temperature is lower than 400 °C or higher than 550 °C, the decrease of volume fraction or the coarsening of L60 phases, respectively, results in the decrease in the distortion of the A2 matrix.

Evolutionary patterns of shear behavior and crack distribution during fault slip

Near-fault mineral resource excavation activities have the potential to induce fault slip, leading to the occurrence of earthquakes. This study explores the effects of dip angle and confining stress on the fault slip process caused by mining stress adjustment indoor tests and numerical simulations. It reveals the evolutionary patterns of shear behavior and crack distribution during the fault slip process. The results indicate that similar to shear stress, the acoustic emission activity associated with fault slip under mining stress exhibits distinct phase characteristics: A few cracks are randomly distributed in the linear steady stage → Isolated crack points cluster gather near the fault in the nonlinear steady stage → Cracks, mainly shear cracks, propagate along the fault in the meta-instability stage → Tension cracks connect shear cracks to propagate perpendicular to the fault in the instability stage. Generally, the fault slip process is governed by shear failure, accounting for over 75 %. Dip angle and confining stress significantly affect the shear behavior and crack distribution during fault slip. The constraint effect of confining stress causes intermittent slip of faults. An inverse relationship exists between peak stress intensity, the number of cracks, and the area impacted by shear slip and the dip angle. Accordingly, this research proposes support measures for areas at potential slip risk on faults, considering slip mechanical conditions and crack distribution characteristics. These results offer a method for identifying different stages of fault slip based on crack propagation, providing theoretical support for the monitoring and early warning of mining-induced fault slip.

Effect of Ti additions on the mechanical properties and thermal expansion properties of Ni9Cr9Co9Fe9Tix (x=1, 2, 3) high entropy alloy

The mechanical properties and thermal expansion properties of high entropy alloys (HEAs) are crucial for practical applications. However, there is a scarcity of research on how to optimize the relationship between the mechanical and thermal expansion properties, which currently restricts the application of HEAs as precision structural materials. To address this critical issue, the present study investigates the mechanical properties and thermal expansion properties of Ni9Cr9Co9Fe9Tix (x=1,2,3) HEAs fabricated via repeated arc melting and casting in a vacuum environment. The results show that Ni9Cr9Co9Fe9Tix HEAs exhibit a typical microstructure characteristic of dendritic and inter-dendritic phase, and a small amount of Ni3Ti phase is formed in the Ni9Cr9Co9Fe9Tix HEAs. The addition of Ti notably increases the tensile strength of Ni9Cr9Co9Fe9Tix HEAs, while the presence of the Ni3Ti phase contributes to a reduction in its thermal expansion coefficient. Notably, HEAs with higher Ti content demonstrate increased yield strength but diminished ductility. The primary mechanisms that strengthen the HEA are solid-solution strengthening, secondary phase hardening and dislocations strengthening of the FCC matrix. This study provides superior mechanical properties for HEAs structural components and reduces the thermal expansion coefficient of the matrix alloy, which also indicated the potential of this material for the design and development of HEAs for precision structural components.

Simulation Method for the Impact of Atmospheric Wind Speed on Optical Signals in Satellite–Ground Laser Communication Links

To analyze the intensity of atmospheric turbulence in a satellite–ground laser communication link, it is important to consider the effect of increased atmospheric turbulence caused by wind speed. Atmospheric turbulence causes a change in the refractive index, which negatively impacts the quality and focusing ability of the laser beam by altering its phase front. To simulate the changes in amplitude and phase characteristics of laser beam propagation in atmospheric turbulence caused by wind speed, a transverse translation phase screen is used. To better understand and address the influence of atmospheric wind speed on the phase of optical signals in satellite–ground laser communication links, this paper proposes a Monte Carlo simulation method. This method utilizes the spatial and temporal variations in the refractive index in the atmosphere and integrates the principles of optical signal propagation in the atmosphere to simulate changes in the phase of optical signals under different wind speed conditions. By analyzing the variations in the received optical signal’s power, the Monte Carlo method is employed to simulate phase screens and logarithmic amplitude screens. Additionally, it models the probability density of the statistical behavior of received optical signal’s fluctuations, as well as the time autocorrelation coefficient of optical signals. This paper, under the coupling condition in satellite–ground laser communication links, conducted a Monte Carlo simulation experiment to analyze the characteristics of the optical signal’s fluctuations in the link and discovered that atmospheric wind speed affects the shape of the power spectral density model of the received optical signal. Increasing wind speed leads to a decrease in the time autocorrelation coefficient of the received optical signal and affects the coupling efficiency. The paper then used a cubic spline interpolation fitting method to verify the models of the power spectral density and the autocorrelation time coefficient of the optical signal. This provides a theoretical foundation and practical guidance for the optimization of satellite–ground laser communication systems.

NUMERICAL MODELING OF THE SEPARATION OF LIQUID AND GASEOUS PHASES OF HYDROCARBON MIXTURES IN A VORTEX CHAMBER

Analysis of the separation process in a vortex chamber is based on the assumption of phase equilibrium existence in the system. Dynamic processes occurring while phases moving in a vortex chamber contribute to the separation of the liquid and gaseous phases of hydrocarbon mixtures. Thus, the transition of the fluid to a metastable state in the vortex chamber will occur in less time than using the traditional methods.Based on the developed model of a vortex chamber in ANSYS FLUENT a series of numerical experiments were carried out. The influence of various parameters on the amount of removal of liquid and gaseous phases of hydrocarbon mixtures was determined. Indicators of the properties of the liquid phase have the greatest impact on the dynamics of the removal of liquid with gas, while the characteristics of the gas phase can be neglected due to their statistical insignificance.When studying the design of a vortex chamber, the smallest removal is observedwhen the inlet pipe is installed further from the top of the chamber (more recessed into the flow). The H/D ratio has less influence, but the offset decreases monotonically as the H/D parameter increases. The influence of the flow rate and the ratio of phases formed in the nozzles on the amount of carryover indicates that with an increase in the gas phase in the incoming flow, the removal of liquid increases. The inlet rate has a less influence.Statistical processing and regression analysis of the results of numerical modeling were carried out. Empirical equations for calculating the amount of droplet liquid removal from the vortex chamber are obtained. The dispersion value was calculated and the significance of the regression coefficients was checked. Based on the results of assessing homogeneity, reproducibility, and adequacy, a conclusion was made about the suitability of the developed model for calculations.

Thermal stability of Ni-based superalloys fabricated through additive manufacturing: A review

Additive manufacturing (AM) is a cutting-edge technique that builds parts by adding layers from a digital design and depositing materials selectively where required. AM is vital in industries like aerospace, healthcare, and automotive because of benefits like design flexibility, cost-efficiency, and customization over conventional methods. Ni-based superalloys AM processes involve phenomena like solidification, phase change, different microstructure characteristics, and melting pool boundaries, affecting both microstructure and mechanical properties. Ni-based superalloys are regarded as potential candidates for high-temperature applications, thanks to their capability to benefit from various strengthening mechanisms such as precipitation hardening and solid solution strengthening. This comprehensive review explores the thermal stability and high temperature softening resistance of additively manufactured (AMed) Ni-based superalloys, from microstructural and mechanical points of view. This review explores the thermal stability and high temperature softening resistance of additively manufactured Ni-based superalloys. It explores the interplay of alloying elements at high temperature, additive manufacturing parameters, and initial microstructure, focusing on grain boundary/sub-boundary networks evolution. The influence of solute drag effect, second phases Zenner pinning effect, and post-processing treatments on microstructural changes such as second phase characteristics, recrystallization (static and dynamic), grain growth phenomena, and textural variations is also analyzed. High temperature mechanical properties of AM-Ni-based superalloys are evaluated, including yield and tensile strength, elongation, work-hardening behavior, creep, and fatigue properties. Hydrogen embrittlement is a significant reason for failure, so this issue is briefly assessed in AM-Ni-based superalloys. Results show that understanding relationships between processing, microstructure, post-processing treatment, and properties is crucial for thermal stability control.

Characterization of 17th century archaeological metallic statuettes using combined neutron tomography and neutron diffraction

A combination of neutron computed tomography and neutron diffraction analysis has been studied to demonstrate the efficacy of employing neutron-based methodologies to investigate brass metallic statuettes, thereby shedding light on their structural and phase characteristics, all the while obviating the need to dissect the sample physically. In order to corroborate the findings obtained from the neutron-based techniques, supplementary methodologies such as Energy Dispersive X-ray Fluorescence were employed to extract elemental information and validate the results. These preliminary findings draw attention to the potential of neutron imaging to unveil intricate information regarding the techniques and components employed by artisans of antiquity in the production of Indian brass artifacts. We were also able to discern concealed structural attributes within metallic statuettes, as well as ascertain the precise phase composition of the brass alloy, thus further enriching our understanding of manufacturing practices of brass statuettes in the 17th-century era.

Full-Color Imaging System Based on the Joint Integration of a Metalens and Neural Network.

Lenses have been a cornerstone of optical systems for centuries; however, they are inherently limited by the laws of physics, particularly in terms of size and weight. Because of their characteristic light weight, small size, and subwavelength modulation, metalenses have the potential to miniaturize and integrate imaging systems. However, metalenses still face the problem that chromatic aberration affects the clarity and accuracy of images. A high-quality image system based on the end-to-end joint optimization of a neural network and an achromatic metalens is demonstrated in this paper. In the multi-scale encoder-decoder network, both the phase characteristics of the metalens and the hyperparameters of the neural network are optimized to obtain high-resolution images. The average peak-signal-to-noise ratio (PSNR) and average structure similarity (SSIM) of the recovered images reach 28.53 and 0.83. This method enables full-color and high-performance imaging in the visible band. Our approach holds promise for a wide range of applications, including medical imaging, remote sensing, and consumer electronics.

Research on the Sentiment Analysis and Evolutionary Mechanism of Sudden Network Public Opinion Based on SNA-ARIMA Model with Text Mining

This article is based on the massive text data in the digital era, using text mining methods to explore the evolution mechanism of online public opinion, in order to achieve the control of public opinion trends in sudden network events and regulate the stability of online and offline public opinion. We introduced time series for decision-making assistance, combined with time series autoregressive integrated moving average model (ARIMA) for prediction, and comprehensively evaluates the evolution of public opinion from two dimensions: sentimental orientation and social network analysis (SNA). Based on this, a new exploration model for public opinion evolution, SNA-ARIMA, is constructed. The research results indicate that the process of public opinion dissemination exhibits distinct phased characteristics, and each stage is comprehensively influenced by different key nodes or factors. This study provides decision support for managing public opinion crises, making the identification of key nodes in online public opinion events, the evolution mechanism of public opinion, and the guidance of public opinion crises more systematic, forward-looking, and scientific.

Braking and Propulsion Phase Characteristics of Traditional and Accentuated Eccentric Loaded Back Squats.

The purpose of this study was to examine the differences in braking and propulsion force-time characteristics and barbell velocity between traditional (TRAD) and accentuated eccentric loaded (AEL) back squats using various load combinations. Sixteen resistance-trained men participated in four separate testing sessions which included a one repetition maximum (1RM) back squat during the first session and three squat testing sessions. During the squat testing sessions, participants either performed sets of three repetitions of TRAD back squats each with 50, 60, 70, and 80% 1RM or performed the same loads with the addition of weight releasers that increased the total eccentric weight of the first repetition of each set to either 100 (AEL-MAX) or 110% 1RM (AEL-SUPRA). Braking and propulsion mean force, duration, and impulse as well as mean and peak barbell velocity were compared between each condition and load. Significantly greater braking impulses were produced during the AEL-MAX and AEL-SUPRA conditions compared to TRAD (p < 0.03) with small-moderate effect sizes favoring AEL-SUPRA. No other significant differences existed among conditions for other braking, propulsion, or barbell velocity variables. AEL-MAX and AEL-SUPRA back squats may provide a greater braking stimulus compared to TRAD squats; however, the propulsion phase of the movement does not appear to be impacted. From a loading standpoint, larger and smaller load spreads may favor rapid and maximal force production characteristics, respectively. Further research on this topic is needed as a large portion of the braking stimulus experienced during AEL back squats may be influenced by relative strength.

Biological sex and hormonal contraceptive associations with drug cue reactivity in cannabis use disorder

Biological sex differences in Cannabis Use Disorder (CUD) progression, cannabis withdrawal severity, and pharmacotherapy response have been reported, suggesting that CUD mechanisms may differ by sex. Drug cue reactivity is an established predictor of drug use behavior, but the literature on sex differences in drug cue reactivity is mixed, including in CUD. One possible moderator of sex differences in drug cue reactivity is hormonal contraceptive (HC) use. The aim of the present study was to test whether sex differences in neural cannabis cue reactivity and craving varied by female HC use in a CUD sample. As part of a larger study, 152 adults reporting frequent cannabis use completed a drug cue reactivity task during electrocenphalogram recording. Late positive potential (LPP) amplitude modulation by cannabis cues was used to measure neural cue reactivity. Craving after the cue reactivity task was also assessed. Males (n = 74) and naturally-cycling females (n = 26), who did not differ from each other, showed significantly greater LPP enhancement to cannabis vs. neutral cues compared to HC-using females (n = 52), an effect mostly driven by neutral cues. Craving was significantly higher in naturally-cycling but not HC-using females compared to males, but only in covariate-unadjusted analyses. Exploratory analyses of HC and menstrual phase characteristics indicate a progesterone-related mechanism may underlie HC effects on cannabis cue reactivity. The present study's results suggest that mixed findings on drug cue reactivity sex differences may be due to variability in HC use, which has implications for sex-specific models of CUD progression and treatment.

Focusing characteristics of space-variant quadratic phase modulated linearly polarized Bessel–Gaussian vortex beam

Focusing characteristics of space-variant quadratic phase modulated linearly polarized Bessel–Gaussian vortex beam

Hallux valgus in children. Biomechanical aspect: A literature review

BACKGROUND: The study comprehensively describes the issues of the normal biomechanics of the first toe, first metatarsophalangeal joint, and first ray when walking. Understanding the fundamental processes of the functioning of these structures is a leading aspect in the study of the etiopathogenesis of hallux valgus and is important in treatment planning.&#x0D; AIM: To analyze the literature concerning the kinematic and kinetic indicators of the first toe, first metatarsophalangeal joint, and first ray of the foot when walking in the final support phase.&#x0D; MATERIALS AND METHODS: The characteristics of periods, gait phases, kinetic and kinematic movements were analyzed.&#x0D; RESULTS: To perform a “push-off” when walking, sufficient extension of the first toe in the first metatarsophalangeal joint is necessary, which is fully accomplished only in combination with flexion and eversion of the first ray of the foot. Muscular control of the position of the first toe in the first metatarsophalangeal joint is carried out by the short and long flexors of the first toe with the sesamoid apparatus of the first metatarsal bone, whereas functions of the first ray and midfoot joints are stabilized by the peroneus longus muscle.&#x0D; CONCLUSIONS: The influence of kinematic and kinetic indicators of movements in the lower-limb joints in the horizontal plane on the flexion of the first ray and extension of the first toe in the metatarsophalangeal joint and the determination of the nature and volume of movements in midfoot joints in various phases of the gait cycle remains a pressing issue.

Effect of Multistage Solution Aging Heat Treatment on Mechanical Properties and Precipitated Phase Characteristics of High-Strength Toughened 7055 Alloy.

In this paper, a one-step hot extrusion dual-stage solution treatment method is employed to fabricate high-strength and tough T-shaped complex cross-section 7055 (Al-Zn-Mg-Cu-Zr) alloy profiles, and a detailed investigation is conducted on the microstructure and mechanical properties. The results indicate that the comprehensive mechanical properties of the 7055 aluminum extruded alloy using the two-stage solution aging treatment are excellent. This is particularly evident in the balance between strength and ductility, where outstanding strength is accompanied by a plasticity that is maintained at 13.2%. During the extrusion process, the deformation textures are mainly composed of brass and copper, forming a 15.1% recrystallization texture Cube. In addition, the equilibrium phase η(MgZn2) precipitated in the grain is the main strengthening phase, and there are large discontinuous grain boundary precipitates at the grain boundary, which hinders the grain boundary dislocation movement and has great influence on the mechanical properties of alloy materials.

High-speed and high-precision measurement of biaxial in-plane displacements: tens of nanometers principle error suppression in microprobe sensors

When the microprobe sensor is faced with the demand of high-speed biaxial displacement measurement, due to the characteristics of phase generated carrier (PGC) technology, accompanying optical intensity modulation (AOIM) and unfavorable phase modulation depth (PMD) will bring about the tens of nanometer cyclic nonlinear errors, further hindering high-speed and high-precision measurement. Herein, a light source intensity stabilization system based on semiconductor optical amplifier (SOA) feedback control is achieved to eliminate the error caused by AOIM in the presence of high-frequency and large-amplitude laser modulation. Based on this, the reasons for large nonlinear errors in biaxial measurements and the inability to ensure the stability of the accuracy of multiple measurement axes are methodically examined, and an effective nonlinear error elimination methodology based on the normalized amplitude correction of active temperature scanning is proposed. The continuity and linearity of the temperature scanning are also discussed. The performed experiments show that the above approach is capable of reducing the displacement demodulation error from the nanometer scale to the sub-nanometer scale. Further, the nonlinear error is reduced to within 0.1 nm for both measurement axes and the performance becomes consistent. The dual-axis measurement resolution of the microprobe sensor reaches 0.4 nm and the measurement speed is better than 1.2 m/s with the standard deviation of lower than 0.5 nm.

Navigating loneliness: the interplay of social relationships and coping skills

ABSTRACT This study explores the (characteristics of) social relationships and coping efforts that protect emerging adults from feeling lonely. The research question is ‘what do emerging adults need in order to not feel lonely?’. Semi-structured interviews with university students from the Netherlands (N = 29; 20–26 years) were conducted between November 2021 and February 2022. Thematic analysis was used to analyse the data. All participants had experiences with loneliness. In order to not feel lonely, participants needed functional, available social relationships with specific others. Quantitative and qualitative characteristics of social relationships were discussed. Furthermore, participants needed to know and accept themselves and to have realistic expectations about others. In terms of coping, participants made active efforts to improve social relationships and altered expectations about others. The results are discussed in line with social discrepancy theory, coping theory, and characteristics of the life phase of emerging adulthood. Implications for loneliness interventions are discussed.