Phase Pattern Research Articles

Child-therapist interaction features impact Autism treatment response trajectories

BackgroundIdentifying mechanisms of change in Autism treatment may help explain response variability and maximize efficacy. For this, the child-therapist interaction could have a key role as stressed by developmental models of intervention, but still remains under-investigated. AimsThe longitudinal study of treatment response trajectories considering both baseline and child-therapist interaction features by means of predictive modeling. Methods and ProceduresN = 25 preschool children were monitored for one year during Naturalistic Developmental Behavioral Intervention. N = 100 video-recorded sessions were annotated with an observational coding system at four time points, to extract quantitative interaction features. Outcomes and ResultsBaseline and interaction variables were combined to predict response trajectories at one year, and achieved the best predictive performance. The baseline developmental gap, therapist’s efficacy in child engagement, respecting children’s timing after fast behavioral synchronization, and modulating the interplay to prevent child withdrawal emerged as key factors. Further, changes in interaction patterns in the early phase of the intervention were predictive of the overall response to treatment. Conclusions and ImplicationsClinical implications are discussed, stressing the importance of promoting emotional self-regulation during intervention and the possible relevance of the first period of intervention for later response.

Taxon-specific, phased siRNAs underlie a speciation locus in monkeyflowers.

Taxon-specific small RNA loci are widespread in eukaryotic genomes, yet their role in lineage-specific adaptation, phenotypic diversification, and speciation is poorly understood. Here, we report that a speciation locus in monkeyflowers (Mimulus), YELLOW UPPER (YUP), contains an inverted repeat region that produces small interfering RNAs (siRNAs) in a phased pattern. Although the inverted repeat is derived from a partial duplication of a protein-coding gene that is not involved in flower pigmentation, one of the siRNAs targets and represses a master regulator of floral carotenoid pigmentation. YUP emerged with two protein-coding genes that control other aspects of flower coloration as a "superlocus" in a subclade of Mimulus and has contributed to subsequent phenotypic diversification and pollinator-mediated speciation in the descendant species.

A Phased Array Antenna with Novel Composite Right/Left-Handed (CRLH) Phase Shifters for Wi-Fi 6 Communication Systems

A linear phased array antenna excited with a novel composite right/left-handed (CRLH) phase shifters structure is proposed. The phase of the conventional CRLH transmission line is controlled with magnetically aligned micron-sized particles embedded inside the unit cell of the CRLH transmission line. The cascading of unit cells produces the desired phase shifts for the main beam scanning of the linear antenna array operating at a 5.5 GHz center frequency for Wi-Fi 6 applications. The proposed phase shifter design has a very low insertion loss (0.5–2 dB), excellent matching characteristics with the antenna array (less than −10 dB) and a small phase error (1–2 degrees). A 1 × 4 linear patch antenna phased array operating at a 5.5 GHz center frequency of the Wi-Fi 6 band is simulated using the Method of Moments (MoM) simulator platform. Then, the array is driven with the proposed novel CRLH phase shifters for the main beam at broadside and the main beam steered at 15- and 30-degree scan angles toward the desired users. For experimental validation, multiple unit cells of the proposed phase shifters are fabricated, and the 1 × 4 patch antenna array is fed with these fabricated unit cells of the phase shifters. The phased array radiation patterns are measured using an in-house fully calibrated anechoic chamber and were compared with simulated phased array patterns. The measured phased array patterns are in good agreement with the simulated patterns. As compared with commercially available phase shifters, the proposed novel CRLH phase shifters do not need external complex biasing circuitry, which is a major advantage in space constraint limitations at the router side of multi-user MIMO-OFDM systems.

Hydrodynamics and mass transfer around active particles in dense gas-fluidized beds

The hydrodynamics of bubbling fluidized beds of Geldart B granular solids operated at ambient temperature and at 500 °C are investigated by uncooled capacitance probes at different gas superficial velocities. Statistical analysis of the time-series of the local bed voidage generates Probability Density Functions (PDF) that display multimodal patterns. A remarkable bimodal character is apparent in the part of the PDF that refers to the emulsion phase when the gas superficial velocity is increased. It is inferred that two phases with different porosity co-exist in the emulsion phase: a lower voidage LV-phase and a higher voidage HV-phase. The link between the LV- and HV-phases as assessed from PDF of capacitance signals and the actual flow patterns induced in the emulsion phase by the bubbles is open to scrutiny.Along a different path, the influence of the bed hydrodynamics and expansion patterns of the emulsion phase on the gas mass transfer around a freely moving coarse active particle is investigated. To this end, mass transfer-limited reaction experiments are performed, consisting in catalytic oxidation of carbon monoxide at 450 °C over Pt-loaded γ-alumina spheres immersed in the fluidized bed. The mass transfer coefficient around the freely moving active particles is measured and worked out to calculate the particle Sherwood (Sh) number. Results obtained from reaction experiments confirm the close relationship between mass transfer and expansion patterns of the emulsion phase, and the need for proper hydrodynamic characterization of the bed. A Frӧssling-type equation, Sh=2·∊e+K·(Ree/∊e)1/2·Sc1/3, well correlates the results. Sh increases with fluidization gas velocity and a best fitting is obtained using the bed voidage of the HV-region of the emulsion phase in the correlation.

Preparation of nanosheets embedded ZnSe/Bi2Se3 core/shell quantum dots for the study of optical properties and antibacterial activity

Cation exchange reaction is a well-known ion exchange method that is very much feasible for easy synthesis procedure and greater tunability in size and shape of nanomaterials. Here, we have synthesized different water dispersed ZnSe/Bi2Se3 core/shell quantum dots by using the cation exchange method with varying Bi content. The variation in Bi concentration allows the change in shell thickness which ultimately affects the structural and optical behaviors. The ZnSe/Bi2Se3 quantum dots exhibited type II band alignment. The as-prepared quantum dots embedded nanosheets exhibit broad, amorphous XRD pattern of the ZnSe phase. A shift in the peak position of the XRD pattern as well as Raman vibrational bands with varying Bi content suggests the formation of the Bi2Se3 shell. Also, the shifting among the XPS peaks confirms the change in the chemical environment of both Zn-Se and Bi-Se bonds in the hybrid system. This ensures the Se ions on the surface of ZnSe coordinated the bismuth complex. The increase in shell thickness enhances the band edge absorption and reduces the optical bandgap which is due to the increase in the particle size of the sample. A broad photoluminescence emission is observed for all the cases with 514 and 325 nm excitation. Each broad spectrum is comprised of different component peaks corresponding to excitonic and defects (vacancies and interstitials) related emission. The core/shell materials are most suitable for different biomedical applications. Hence, the ZnSe/Bi2Se3 quantum dots are analyzed for antibacterial activity, which showed a good antibacterial response against Staphylococcus aureus (ATCC 25,923).

Laser-Induced Phase Transition and Patterning of hBN-Encapsulated MoTe2.

Transition metal dichalcogenides exhibit phase transitions through atomic migration when triggered by various stimuli, such as strain, doping, and annealing. However, since atomically thin 2D materials are easily damaged and evaporated from these strategies, studies on the crystal structure and composition of transformed 2D phases are limited. Here, the phase and composition change behavior of laser-irradiated molybdenum ditelluride (MoTe2 ) in various stacked geometry are investigated, and the stable laser-induced phase patterning in hexagonal boron nitride (hBN)-encapsulated MoTe2 is demonstrated. When air-exposed or single-side passivated 2H-MoTe2 are irradiated by a laser, MoTe2 is transformed into Te or Mo3 Te4 due to the highly accumulated heat and atomic evaporation. Conversely, hBN-encapsulated 2H-MoTe2 transformed into a 1T' phase without evaporation or structural degradation, enabling stable phase transitions in desired regions. The laser-induced phase transition shows layer number dependence; thinner MoTe2 has a higher phase transition temperature. From the stable phase patterning method, the low contact resistivity of 1.13kΩµm in 2H-MoTe2 field-effect transistors with 1T' contacts from the seamless heterophase junction geometry is achieved. This study paves an effective way to fabricate monolithic 2D electronic devices with laterally stitched phases and provides insights into phase and compositional changes in 2D materials.

Hybrid diffractive optics (DOE & refractive lens) for broadband EDoF imaging

In the considered hybrid diffractive imaging system, a refractive lens is arranged simultaneously with a multilevel phase mask (MPM) as a diffractive optical element (DOE) for Achromatic Extended-depth-of-field (EDoF) imaging. This paper proposes a fully differentiable image formation model that uses neural network techniques to maximize the imaging quality by optimizing MPM, digital image reconstruction algorithm, refractive lens parameters (aperture size, focal length), and distance between the MPM and sensor. Firstly, model-based numerical simulations and end-to-end joint optimization of imaging are used. A spatial light modulator (SLM) is employed in the second stage of the design to implement MPM optimized at the first stage, and the image processing is optimized experimentally using a learning-based approach. The third stage of optimization is targeted at joint optimization of the SLM phase pattern and image reconstruction algorithm in the hardware-in-the-loop (HIL) setup, which allows compensation for a mismatch between numerical modeling and the physical reality of optic and sensor. A comparative analysis of the imaging accuracy and quality using the optical parameters is presented. It is proved experimentally, first time to the best of our knowledge, that wavefront phase modulation can provide imaging of advanced quality as compared with some commercial multi-lens cameras.

Lightweight Fan-Beam Microstrip Grid Antenna for Airborne Microwave Interferometric Radiometer Applications.

The microwave interferometric radiometer (MIR) uses aperture synthesis technology to equate multiple small-aperture antennas into a large-aperture antenna to improve spatial resolution. At present, MIR antennas that operate at frequencies above the C-band mostly use horn antennas, waveguide slot antennas, etc., which have the disadvantages of a high profile and large mass. In this paper, a new type of miniaturized, low-profile, and lightweight K-band fan-beam microstrip grid antenna is designed for the airborne campaign of the K-band one-dimensional MIR of a Microwave Imager Combined Active and Passive (MICAP) onboard a Chinese Ocean Salinity Mission (COSM). With a limited size constraint (12.33 mm) on the antenna width, a fan-beam shape antenna pattern was achieved with a 5.34° 3-dB beamwidth in the narrow beam direction and up to a 55° 3-dB beamwidth in the fan-beam direction. A periodic structural unit is proposed in this paper to reduce the design complexity of Taylor weighting, achieving desirable performances on gain (19.1 dB) and sidelobe level (<-20 dB) in the H-plane. Four antenna elements were fabricated and arranged in a non-redundant sparse array. The performance of the four-element sparse array was evaluated with a simulation and real measurement in an anechoic chamber. The coupling between antenna elements was less than -25 dB, and the consistency of phase patterns was better than 3.4°. These results verify the feasibility of the proposed K-band microstrip grid antenna for airborne MIR applications.

Generation of V-point polarization singularity using single phase encoding with a spatial light modulator

A liquid crystal Spatial Light Modulator (SLM) can be used in various ways to produce vector-vortices. Superposition of scalar vortices with orthogonal polarization is a common approach, while a more recent technique is to use dual-phase modulation. These approaches require modulation of at least two phase patterns with a SLM or multiple SLMs. In this paper, we propose a novel technique to produce vector-vortices by modulating orthogonal light components through a single phase pattern with a SLM. It does not require interferometric setups, and simplifies the generation of light beams with V-point polarization singularities. Because of compact and robustness of our experimental setup, it can be easily integrated to any device for applications of vector-vortices.

Neural computing with coherent laser networks

Abstract We show that coherent laser networks (CLNs) exhibit emergent neural computing capabilities. The proposed scheme is built on harnessing the collective behavior of laser networks for storing a number of phase patterns as stable fixed points of the governing dynamical equations and retrieving such patterns through proper excitation conditions, thus exhibiting an associative memory property. It is discussed that despite the large storage capacity of the network, the large overlap between fixed-point patterns effectively limits pattern retrieval to only two images. Next, we show that this restriction can be uplifted by using nonreciprocal coupling between lasers and this allows for utilizing a large storage capacity. This work opens new possibilities for neural computation with coherent laser networks as novel analog processors. In addition, the underlying dynamical model discussed here suggests a novel energy-based recurrent neural network that handles continuous data as opposed to Hopfield networks and Boltzmann machines that are intrinsically binary systems.

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.

Programmable freeform optics with extended white light sources: possibilities and limitations.

Freeform optics can be used in lighting applications to generate accurate prescribed illumination patterns from compact light sources such as LEDs. When targeting dynamic illumination systems, a time-variable optical functionality is needed. Phase-only spatial light modulators (SLMs) have been used in the past for various dynamic beam shaping applications with monochromatic, zero-étendue illumination under paraxial conditions. Such limitations can no longer hold when considering lighting applications. In this paper, a novel algorithm for the calculation of smooth phase shift patterns is presented in order to generate arbitrary target patterns from arbitrary incident wave fronts for non-paraxial conditions. When applying such phase shift patterns to SLMs, these devices can be considered as programmable freeform optics. The experimental performance of the calculated phase patterns is analyzed on a real SLM, with a maximal phase shift of 6π, for collimated laser beams and white LEDs. The possibilities and limitations of generating accurate prescribed target patterns are critically discussed in terms of the angular extent of the target pattern, the consider spectrum of the light source and the étendue of the incident light beam.

The differential diagnosis of pancreatic cystic neoplasms with conventional ultrasound and contrast-enhanced ultrasound.

Advances in imaging have improved the detection rate of pancreatic cystic neoplasms (PCNs), but clinical management varies depending on the pathological type of PCNs, and thus accurate differential diagnosis is of considerable clinical significance. We conducted this study to identify the clinical and sonographic features of PCNs with significance for differential diagnosis and to compare the diagnostic accuracy of conventional ultrasound and conventional ultrasound combined with contrast-enhanced ultrasound (CEUS) for PCNs. From January 1, 2011, to December 31, 2022, a total of 100 patients with PCNs who underwent CEUS examination and were confirmed to have PCNs by postoperative pathology in West China Hospital of Sichuan University were included in this study. Of the clinical characteristics of PCNs, age and gender were found to be important differential diagnostic features. Moreover, communication of the lesion with the main pancreatic duct on conventional ultrasound and CEUS images was a critical feature in the differential diagnosis of intraductal papillary mucinous neoplasm (IPMN). The size of the lesion, the thickness of the cyst wall and the number of septa in conventional ultrasound images, the uniformity of the cyst wall thickness in CEUS images, and the enhancement pattern in the arterial phase were significant features for the differential diagnosis of serous cystic neoplasm (SCN). Cyst wall thickness and uniformity of the cyst wall thickness in conventional ultrasound images and cyst wall thickness and septa thickness in CEUS images were important features in the differential diagnosis of mucinous cystic neoplasm (MCN). The size and internal components of the lesion on conventional ultrasound images, internal components of the lesion, and the enhancement pattern in the arterial phase and rim enhancement on CEUS images were the key features in the differential diagnosis of solid pseudopapillary neoplasm (SPN). Conventional ultrasound combined with CEUS demonstrated significantly greater accuracy than did conventional ultrasound alone in the differential diagnosis of PCNs (66% vs. 79%; P=0.002). PCN types differ in their clinical and ultrasound features. Conventional ultrasound combined with CEUS can better distinguish between different pathological types of PCNs than can conventional ultrasound alone.

Multi-Feed Metasurface Antennas: Direct Numerical Design and Experimental Validations

This paper provides new designs and realizations of leaky-wave (LW) metasurface (MTS) antennas fed at multiple points. The design technique is based on the direct integral-equation solution by the Method of Moments (MoM). The unknown is no longer the current distribution, but the impedance profile itself. The method can be used to generate any shaped radiation pattern in amplitude, phase, and polarization, provided that the antenna area and the feeder illumination are consistent with the shape of the desired radiation pattern. The algorithm can also be used to design multi-functional antennas (multibeam, multiband, dual-polarizion, etc). While multiple feeds are traditionally used to implement multiple fonctionnalities, they may also be required for the efficient generation of a single shaped beam, thus leading to a higher surface-wave (SW) to LW conversion efficiency. The present paper shows for the first time, two realizations of MTS design with the integral equation formalism, which require the usage of multiple feeds: a circularly polarized sectoral conical beam and a dual-polarized broadside beam MTS antenna. The good comparison between measurements and numerical predictions shows the effectiveness of the design method.

Effects of Horus Antenna Patterns on the Copolar Correlation of Weather Returns

The effects of phased array antenna patterns on copolar correlation coefficient of polarimetric radar are analyzed. Analytic expressions are derived and used to quantify biases in the copolar correlation coefficient caused by mismatch of beam widths for horizontal and vertical polarizations. Misalignment in the beams’ pointing direction is also considered. Measurements are made on an 8×8 panel of a polarimetric phased array radar (PPAR) under development by the Advanced Radar Research Center at the University of Oklahoma in collaboration with NOAA’s National Severe Storms Laboratory. The all-digital radar is called Horus and some measurements on a partially populated antenna are presented.

Seismic Response Characteristics of a Tunnel Portal Subjected to Topographical and Geological Asymmetsric Loading

The tunnel portal is the most seismically vulnerable section of the tunnel against earthquakes. Due to the combined effects of topographic and geological asymmetric loading, the mechanical characteristics of this type of portal are very complex. In this study, a three-dimensional numerical model was developed and calculated to investigate the seismic response characteristics of a tunnel portal subjected to topographic and geological asymmetric loading. The results show that the seismic weakness of the tunnel support structure is located at the tunnel arch shoulders and sidewalls; the time to reach the peak displacement around the tunnel is slightly delayed compared to the slope, and the time to reach the peak displacement shows a phased pattern. Compared to the tunnel structure, the slopes are more prone to landslides and other disasters due to terrain and geological factors under earthquake action. Therefore, more attention should be paid to the seismic and anti-seismic design of tunnel slopes.

Design of Bowtie Antenna With Rounded Edge and Middle-Sliced Modifications for UHF Partial Discharge Sensor

Partial Discharge (PD) detection using ultra-high frequency (UHF) method has been proven as more noise-resistant in GIS condition monitoring, compared to the conventional PD detection methods, where the common noise frequency range such as in the power plants is below UHF frequency range. However, noise in UHF range may occur at certain conditions. Thus, UHF sensor with high sensitivity is necessary to detect PD-induced electromagnetic wave in UHF range. This paper discusses the modified design of a bowtie antenna as UHF sensor and its performance in detecting PD in the air. The modification method is conducted through simulation using antenna design software, resulting in curved-edge and middle sliced bowtie antennas. The designed bowtie antenna has wider bandwidth of above 300 MHz, reflection coefficient lower than -10 dB, and the voltage standing wave ratio (VSWR) less than 2. During initial design, the antenna geometry including gap distance, wing radius, and flare angle are adjusted to obtain the optimum antenna characteristics. The final designed sensor is then fabricated on a printed circuit board (PCB) with FR4-epoxy substrate material and tested using Vector Network Analyzer (VNA). Furthermore, the modified antennas are also tested in the high voltage laboratory to detect PD in needle–plane electrode. The experiment results show that both modified bowtie antennas can successfully detect the PD signal with correct phase patterns, and that the middle-sliced modified bowtie antenna is more sensitive than the rounded edge modified bowtie antenna.

THE CORRELATION OF MICROSTRUCTURE, AND MECHANICAL PROPERTIES OF NOVEL Fe3O4-(AuTe2) –REINFORCED ALUMINIUM MATRIX COMPOSITE PRODUCED VIA RECRYSTALLIZATION ROUTE

Aluminum Metal Matrix Composites (AMMC) have been becoming suitable materials for many devices in the application of various fields such as medical equipment, aircraft, electrical motors, overhead transmission lines, construction, etc. Aluminum was reinforced with the Fe3O4-(AuTe2) through the recrystallization process, hence, AMMC was successfully developed. The aim was to characterize the microstructure and phase patterns of the developed AMMC and compare it with conventional Aluminum as well as its thermos-mechanical characteristics. Physical, mechanical, and morphological properties of the composite and regular Al were examined. Based on the outcomes, the microstructural examination of the composite showed that the Al matrix had a sizable distribution of reinforcement components. Additionally shown was the creation of new phases, which significantly improved the strength and corrosion resistance of the composite. The influence of the reinforcement materials was found to have greatly enhanced the hardness tests. From 60 HRB for ordinary Al to 92.3 for AMMC, the hardness rose. Hence, after corrosion tests in an acidic solution (5% H2SO4 + H2O) hardness also increased from 41.1 HRB of the conventional Al to 52.8 HRB of the AMMC. Therefore, Corrosion resistance is improved by adding this reinforcement (Al- Fe3O4-(AuTe2) to the composite (lower corrosion rate). We then chose Al-5Fe3O4-10(AuTe2) as an optimal composite after comparing all the samples.

High Aperture Efficiency Arced Conformal Array With Phasor Beam Steering Antenna

A phasor beam steering stacked patch antenna with abilities of both the amplitude and phase pattern reconfigurations is proposed and used for improving the aperture efficiency of arced conformal array. The phasor beam steering antenna is composed of two parasitic patches on the top integrated with four PIN diodes and a driven patch on the lower layer. By switching the bias states of the PIN diodes, the induced complex current of the top patch is alterable and the phasor beam steering can be delivered. Thus, in the conformal array design, the phase compensation can be realized by the phase pattern reconfiguration of the phasor beam steering antenna instead of the conventionally used phase delay lines. Meanwhile, the amplitude pattern reconfiguration of the phasor beam steering antenna can also be used for enhancing the contribution of side elements to the gain of axial beam. A four-element arced conformal array with the phasor beam steering antenna is designed and measured for verification. Both the simulated and measured results indicate that the realized gain of the proposed conformal array is 12.0 dBi, and the corresponding aperture efficiencies are improved up to 51.48%, which is better than the results of the arced conformal array with the phase compensation network.

Safe energy-storage mechanical metamaterials via architecture design

Mechanical and functional properties of metamaterials could be simultaneously manipulated via their architectures. This study proposes multifunctional metamaterials possessing both load-bearing capacity and energy storage capability, comprising multi-phase lattice metamaterial and cylindrical battery cells. Defect phase are incorporated into the metamaterials, which are then printed with stainless steel powder. The printed metamaterials are assembled with battery cells and compressed. Experimental results revealed that the voids in the lattice metamaterials, could guide deformation mode away from the internal battery cell that postponed the emergence of battery short-circuit. Effects of void phase pattern and content are discussed by simulation. We found that the multifunctional system could absorb greater energy after defect phase incorporation, as designed with proper void phase pattern and content. Also, these findings are further validated for the system with six battery cells. This study demonstrated how to design an energy-storage metamaterials with enhanced mechanical properties and battery safety simultaneously. Also, defect engineering was helpful for battery protection and energy absorption of the multifunctional system.