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Multifoci focusing has always been a problem that researchers continue to pay attention to and urgently needs to be solved. Metasurfaces display unprecedented capabilities and flexibilities to solve this problem. In this work, Pancharatnam–Berry (PB)‐phase‐based plasmonic metasurfaces are presented to realize wavelength‐selective directional focusing on the same focal plane. Ultrathin meta‐atoms with the half‐wave plate effect have only three layers, and 360° phase modulation is obtained by axially rotating gold strip based on PB phase. Two metasurfaces are designed to verify our strategy. Above all, a wavelength‐selective directional focusing metasurface is presented to converge right‐handed circularly polarized wave with wavelengths of 187, 271, and 355 μm at different predetermined positions at 810 μm. Next, the second metasurface exhibits the function that three vortex beams carrying orbital angular momentums with different topological charges can be produced under the irradiation of incident wave at the aforementioned wavelengths. In this research, a solid step is paved toward practical applications of flat photonics. [ABSTRACT FROM AUTHOR]

In this paper, a bifunctional full-space metasurface (FS-MS) with dual-band is proposed. Two metal layers are located on each side of the unit dielectric substrate, independently regulating the phase in the transmission and reflection. The metasurface can reflect x-polarized waves at 28 GHz and transmit y-polarized waves at 35 GHz. Based on the anisotropy and Huygens theories, the reflected and transmitted beams can be tuned flexibly. The metasurface design is carried out as an illustration of the reflected Bessel beams and the transmitted focusing or OAM beam. The results show that the metasurfaces can realize double zero-order Bessel beams, bifocals with a focusing efficiency of 22.27%, and an OAM beam with a mode purity of 74.12%. The proposed FS-MS, devoid of multilayer stacking and metal perforations, exhibits a simple structure, low profile, and ease of processing, all of which make them a promising candidate for applications in intelligent housing systems. [ABSTRACT FROM AUTHOR]

The paper considers the problem of forming the maximum amplitude of the electric field strength at a required point using two identical one-dimensional linear antenna arrays located orthogonally to each other and focused at one point in space. Relationships have been obtained that allow us to determine the geometric dimensions of all areas. The results of theoretical calculations of the sizes of the zone of increased electric field intensity turned out to be close to the results of simulation. For example, the size of the zone of increased electric field intensity for two orthogonal antenna arrays consisting of 20 elements, the theoretical dimensions of the zone of increased intensity were 310 mm. The simulation results showed the dimensions of this zone to be equal to 325 mm, which is explained by taking into account the influence of radiation from the other antenna array. [ABSTRACT FROM AUTHOR]

Wireless communications are nowadays shifting to higher operation frequencies with the aim to meet the ever-increasing demand for bandwidth. While reconfigurable intelligent surfaces (RISs) are usually envisioned to restore the line-of-sight of blocked links and to efficiently counteract the increased pathloss, their functionalities can extend far beyond these basic operations. Owing to their large surface and the multitude of scatterers, RISs can be exploited to perform advanced wavefront engineering, essentially transforming the incident beam into a non-trivial reflected beam that is able to address the challenges of high frequencies more efficiently than conventional beam-forming. In this paper, it is demonstrated how advanced wavefront engineering with RISs enables beam profiles that are able to focus, bend and self-heal, thus offering functionalities beyond the current state-of-the-art. Their potential as enablers of perceptive, resilient, and efficient networks is discussed, and a localization technique based on a hybrid beam-forming/beam-focusing scheme is demonstrated. [ABSTRACT FROM AUTHOR]

The possibility of increasing the current density of a charged particle beam (focusing) by means of tapered glass channels without the use of external energy sources is actively translated into action today for positively charged ions. For electron beams, this possibility is not realized due to the lack of experimental data on the sliding interaction between electron beams and a dielectric surface. It is necessary to examine the compression of an electron beam by tapered capillaries depending on their geometrical parameters, as well as to study the temporal characteristics of the focusing process. In this work, the authors experimentally studied the compression of a 10 keV electron beam using a 15-mm-long tapered glass channel with an inlet-to-outlet inside diameter ratio of 1.15 mm/0.30 mm. The beam current density is shown to increase at the outlet of the capillary with the specified parameters by up to a factor of 2.7 for the position where the channel axis is parallel to that of the initial beam. This density increase is estimated for electrons that have lost no more than 1 keV of initial energy. It is also shown that the process of electron transmission by a tapered capillary is stable regardless of the orientation of the capillary with respect to the direction of the initial beam. [ABSTRACT FROM AUTHOR]

Label-free super-resolution (LFSR) imaging relies on light-scattering processes in nanoscale objects without a need for fluorescent (FL) staining required in super-resolved FL microscopy. The objectives of this Roadmap are to present a comprehensive vision of the developments, the state-of-the-art in this field, and to discuss the resolution boundaries and hurdles which need to be overcome to break the classical diffraction limit of the LFSR imaging. The scope of this Roadmap spans from the advanced interference detection techniques, where the diffraction-limited lateral resolution is combined with unsurpassed axial and temporal resolution, to techniques with true lateral super-resolution capability which are based on understanding resolution as an information science problem, on using novel structured illumination, near-field scanning, and nonlinear optics approaches, and on designing superlenses based on nanoplasmonics, metamaterials, transformation optics, and microsphere-assisted approaches. To this end, this Roadmap brings under the same umbrella researchers from the physics and biomedical optics communities in which such studies have often been developing separately. The ultimate intent of this paper is to create a vision for the current and future developments of LFSR imaging based on its physical mechanisms and to create a great opening for the series of articles in this field.

Ultrawideband (UWB) time‐reversal techniques are widely used in microwave imaging systems to detect and localize breast tumors. Measuring the scattering electromagnetic fields from a breast phantom can be time‐reversed and back‐propagated to refocus on a tumor. In this study, a Debye model was applied to the breast phantom. Using the decomposition of the time‐reversal operator (TR‐DORT), images were obtained in the UWB frequency range of 3.1–10.6 GHz. The conventional TR imaging method employs the free‐space Green's function to refocus on the tumor, which degrades refocusing in a lossy and dispersive breast phantom. We propose the use of the cylindrical dyadic Green's function in a three‐layer medium for TR imaging. The excitation system consists of a circular array of spiral antennas. The imaging results of the proposed Green's function in TR‐DORT were subsequently calculated, indicating successful tumor detection in different application scenarios of the lossy and dispersive breast phantom. [ABSTRACT FROM AUTHOR]

Introduction: Focusing-Oriented Psychotherapy has had a long history and influence on the field of psychotherapy. By "clearing a space" and "focusing," individuals can enhance their emotional awareness and improve their ability to self-regulate. These tasks are particularly relevant in the context of Psycho-Oncology, although the research on their potential benefits for cancer patients is limited. Furthermore, the application of these tasks in a group or online setting has not been thoroughly explored. Methods: This study aimed to examine the effectiveness of a two-session online intervention based on Focusing for cancer-diagnosed participants and its impact on their mental health and wellbeing. The study involved three participants with a diagnosis of colorectal cancer who were undergoing palliative treatment. We used both qualitative and quantitative methods. PFC-2 was used to assess participants' accomplishment of the task; FMS was used to assess the change in the focusing attitude, while CORE-OM, and PWBS-RV were used as mental health distress and psychological wellbeing measures; participant feedback was collected through questionnaires and a semi-structured interview. Results: The results suggest that the tasks led to greater self-awareness, heightened self-reflection, and a sense of relief for the participants. Discussion: These findings suggest that the group intervention protocol based on online Focusing sessions is potentially useful for broader applications. [ABSTRACT FROM AUTHOR]

Holographic processing of hydroacoustic noise signals in randomly inhomogeneous ocean environment is presented. A method of hologram purification from a perturbed field is described. An algorithm of resolving signals using a single detector is presented. Focusing of signal spectral density on a hologram is considered. Criteria of signal resolution are proposed. Results of numerical simulation of the resolution of two hydroacoustic signals against the background of intense internal waves, conditioning coupling of sound field modes, are shown. [ABSTRACT FROM AUTHOR]

Focusing and separation of cells by microfluidic techniques are significant steps in many applications, such as single-cell analysis and disease diagnosis. Among the microfluidic techniques, passive magnetophoresis, as a label-free manner, can manipulate samples by means of magnetic field. Nowadays, most magnetic fields are generated by permanent magnets and electromagnets with large size. However, it is difficult to assemble a magnetic array using permanent magnets or electromagnets to optimize the field distribution. To produce a flexible magnetic field, a micro-magnet made by NdFeB powder and polydimethyl siloxane is proposed in this paper, and those magnetized micro-magnets are arranged into different arrays according to the arrangements of their magnetization directions. Meanwhile, a microfluidic chip containing magnetized micro-magnet arrays is designed for focusing and separating polystyrene microbeads with different diameters. The focusing and separation behaviors of microbeads in the designed microfluidic system are numerical and experimental investigated. In addition, the effects of flow rate and the arrangement of the magnetic micro-magnet array on microbead focusing and separation are discussed. Finally, a multistage microfluidic chip is designed to successfully isolate 5 μm-diameter, 10 μm-diameter, and 15 μm-diameter microbeads from their mixture at a flow rate of 240 μL/min with high purity. [ABSTRACT FROM AUTHOR]

Multifoci focusing has always been a problem that researchers continue to pay attention to and urgently needs to be solved. Metasurfaces display unprecedented capabilities and flexibilities to solve this problem. In this work, Pancharatnam–Berry (PB)‐phase‐based plasmonic metasurfaces are presented to realize wavelength‐selective directional focusing on the same focal plane. Ultrathin meta‐atoms with the half‐wave plate effect have only three layers, and 360° phase modulation is obtained by axially rotating gold strip based on PB phase. Two metasurfaces are designed to verify our strategy. Above all, a wavelength‐selective directional focusing metasurface is presented to converge right‐handed circularly polarized wave with wavelengths of 187, 271, and 355 μm at different predetermined positions at 810 μm. Next, the second metasurface exhibits the function that three vortex beams carrying orbital angular momentums with different topological charges can be produced under the irradiation of incident wave at the aforementioned wavelengths. In this research, a solid step is paved toward practical applications of flat photonics.

The actor's focus takes a large part of the kinetic performance and scenic formation after it is a performance technique capable of organizing the space of the theatrical performance, as the focus of the actor takes a means that supports the performance and appears in an acceptable way from the recipient's point of view. In light of the above, the researcher divided his research topic into four chapters. The first chapter (the methodological framework) included the research problem represented by the following question: What is the role of focus techniques in the kinetic formation of the actor's performance in the Iraqi theatrical performance? Then access to the importance of the research and the need for it and the research objective which was determined as follows: Identifying the role of concentration techniques in the movement formation of the actor's performance in the Iraqi theatrical show, in addition to determining the time and place of the research sample and mentioning the terms mentioned in the title text, and the second chapter included two topics, the first: Concentration, its concept, types and tasks, and the second topic was determined under the title: Concentration in the movement actor. Then addressing the paragraph of what the theoretical framework resulted in. The third chapter included the research community and its sample, then determining the methodology that the researcher will follow, represented by the descriptive analytical method, then the research tool that will enable him to analyze the sample, as for the fourth chapter, it was determined by the most important results that the researcher reached through the analysis of the sample, then the conclusions related to the axis of the study, in addition to addressing some recommendations and suggestions to conclude his study with the most important references that he relied on in the facts of the research entitled Concentration techniques in the movement formation of the actor's performance.

In this case study, the character of Miss Havisham, from Dickens’ novel Great Expectations, is explored as a representation of frozen trauma. Support is offered for the usefulness of fictional case study to therapeutic understanding and practice, and some of its limitations noted. The frozen nature of traumatic experiencing is elucidated and defined from a person-centered perspective. A brief synopsis of the story and character of Miss Havisham is offered, and the relevance of her early life considered together with her environment and her social context as a Victorian woman. A case is made for a body response to working with trauma which draws upon Gendlin’s focusing approach and Prouty’s model of Pre-Therapy. Limitations of both are noted. Using fictional case study as a creative method of inquiry, its potential for offering real world understanding around trauma theory is established. The primacy of the body in experiencing trauma, and healing from it, is affirmed. A resonance is illuminated between current thinking around traumatic wounding and healing, and a relational therapeutic approach which has the organism at its heart. Insights have arisen from the therapist’s exploration of ‘tidy[ing] up’ the mess and real change has been experienced in practice with clients. [ABSTRACT FROM AUTHOR]

Manipulating the propagation of mid-infrared (mid-IR) light is crucial for optical imaging, biosensing, photocatalysis, and guiding photonic circuits. Artificially engineered metamaterials were introduced to comprehensively control optical waves. However, fabrication challenges and optical losses have impeded the progress. Fortunately, two-dimensional van der Waals (vdW) materials are alternatives because of their inherent optical properties, such as hyperbolic behavior, high confinement, low loss, and atomic-scale thickness. In this research, we conducted theoretical and numerical investigations on the α-phase molybdenum trioxide, a biaxial vdW material, with patterned graphene to assess the potential of the tunable focusing of mid-IR light. Our proposed method directly alters the path of excited light to focus mid-IR light by negative refraction. Further, the patterned graphene in our design offers enhanced focusing characteristics, featuring a significantly reduced waist diameter with 1/92 of the free-space wavelength, an enhanced beam quality without pronounced field ripples, and a fivefold increase in field intensity. Moreover, our approach significantly preserves the waist diameter of the focused beam while facilitating directional steering. Thus, the focused beam can propagate in a canalized manner toward the desired direction. These advancements lay the foundation for promising applications in planar photonics. [ABSTRACT FROM AUTHOR]

An X-ray point source was used to examine the diffraction behavior of a low-angle twist boundary. It is shown that when radiation is focused inside a crystal, because of the dislocation structure of the defect wall, the vertical divergence can be reduced so much that the size of the focus in this direction is significantly smaller than in the horizontal direction. This circumstance can be used to create X-ray optical elements. [ABSTRACT FROM AUTHOR]

This paper uses MATLAB software to demonstrate the performance of UWBSAR and conducts a comparative study with data obtained from conventional radar. It compares various antennas that support UWB, such as Vivaldi, MIMO, and monopole antennas, analyzed using SIMULINK. The paper discusses the design of UWBSAR to provide a comprehensive analytical picture of the processed images. The focus is on frequency domain analysis in general and the Range Migration Algorithm (RMA) in particular. The data obtained after signal processing is recorded to estimate the crossrange resolution, which is then compared with conventional SAR. The cross-range resolution estimated using UWBSAR is found to be lower than that of conventional radar, proving that UWBSAR is a better alternative for obtaining sharper images in short-range applications. High-quality images are reconstructed using a combination of UWB radar, SAR processing, and proposed algorithms to improve image quality. The investigation includes positive image generation to enhance sharpness and near-field imaging procedures. This paper also describes Ultra-Wideband (UWB) Synthetic Aperture Radar (SAR) and its application in operating at low frequencies to detect obscured targets beneath foliage. While it has obvious military applications, it also has civilian uses, such as in geophysical studies and weather forecasting. Several applications have been identified for both military and civilian environments. [ABSTRACT FROM AUTHOR]

The separation of particles such as cells and bacteria in viscoelastic fluids has significant applications in biomedical fields. At present, one of the main challenges that limit the application of microfluidic technology is to separate particles in the viscoelastic fluids with different rheological properties. For instance, most existing microfluidic devices can only work in the fluid with a specific rheological property, resulting in the requirement of time-consuming design, manufacturing, testing, and optimization of different devices to separate particles in the fluids with different rheological properties. In this work, a novel hybrid three-stage microfluidic device that was made up of a micropore structure and two gradually contracted microchannels was designed to achieve efficient continuous separation of particles in the viscoelastic fluid over a wide range of rheological properties (0.07 < El < 340.41). Different separation strategies including first focusing, then initial separation, and then precise separation (FISPS) and initial separation and then precise separation (ISPS) were found. The separation strategy ISPS occurred at El < 0.14 while the separation strategy FISPS occurred at El > 8.43. In addition, the transformation of the separation mechanism from ISPS to FISPS was found under different flow conditions in the fluid with the transitional rheological properties (0.21 < El < 1.10). The effect of the flow rate and the rheological property of the fluid on microparticle separation were systematically studied by the experiment. With simple structure, easy operation, high separation efficiency, the present microfluidic device would have great potentials in the biomedical and clinical applications, such as the separation of cells for different patients. [ABSTRACT FROM AUTHOR]

The creation of multi-channel focused beams with arbitrary polarization states and their corresponding optical torques finds effective applications in the field of optical manipulation at the micro-nanoscale. The existing metasurface-based technologies for polarization rotation have made some progress, but they have been limited to single functions and have not yet achieved the generation of full polarization. In this work, we propose a multi-channel and spatial-multiplexing interference strategy for the generation of multi-channel focusing beams with arbitrary polarization rotation based on all-dielectric birefringent metasurfaces via simultaneously regulating the propagation phase and the geometric phase and independently controlling the wavefronts at different circular polarizations. For the proof of concept, we demonstrate highly efficient multi-channel polarization rotation meta-devices. The meta-devices demonstrate ultra-high polarization extinction ratios and high focusing efficiencies at each polarization channel. Our work provides a compact and versatile wavefront-shaping methodology for full-polarization control, paving a new path for planar multifunctional meta-optical devices in optical manipulation at micro–nano dimensions. [ABSTRACT FROM AUTHOR]

We evaluated the performance of three flat large‐sized gaming monitors with 35 subjects regarding the recognition of Landolt C with short visualization time and fast movement. A search task using circles in dark and bright conditions and visual fatigue. An OLED monitor performed significantly better than two LCDs. [ABSTRACT FROM AUTHOR]

Background: Previously, there has been some work in the field of optical imaging on phase compensation by employing Legendre polynomials as an expansion of the phase function, and this seems to be an appealing unstudied area in the field of ultrasound imaging. Purpose: The paper is devoted to solving one of the problems of enhancing the authenticity of diagnostics data obtained in ultrasound visualization systems and presents a novel approach to aberration correction, which ensures a reliable eliminating of phase distortions. The novelty of the proposed approach consists in the use of the decomposition of the wave front by Legendre polynomials to approximate aberrations of the phase front of ultrasonic waves propagating through distorting layers. Methods: The phase aberrations are corrected using a single sector probe that captures echoes in synthetic aperture mode. The proposed method approximates the changes in the wave front by means of the Legendre polynomials. The performance was investigated by placing a 13‐mm‐wide ultrasonic probe with 64 elements operating at 2 MHz on the surface of a commercial quality control phantom ATS Model 539 through a distorting layer. The following metrics were measured: peak value, root mean square (RMS), full width at half maximum (FWHM), contrast‐to‐noise ratio (CNR). During the experiments, three different aberrators were used interchangeably as distorting layers, two of which were made of photopolymer resin with RMS values of 39 and 97 ns and a speed of sound close to that of a human temporal bone tissue, and the third was an ex vivo human temporal bone with the RMS value of 44 ns. To test the correction, three regions inside the phantom were examined. Two‐sided nonparametric Wilcoxon rank‐sum test was used for assessing the statistical significance. The significance level for this study was set at α ≤ 0.05. To counteract the problem of multiple comparisons, the p‐values were adjusted by the Holm–Bonferroni correction method. Results: The statistically significant results have demonstrated the possibility of increasing peak intensity value up to 3.08 times, reducing the RMS width and FWHM of the intensity angular distribution down to 60% and 82%, respectively, and increasing CNR up to 2.12 times by using the proposed phase distortion correction method, compared with the case without correction. The results show that the method can be used as an effective aberration correction technique for all tested regions inside the phantom and distorting layers. Its usage allowed correcting up to 97% of the aberrations caused by the ex vivo temporal bone model. Conclusion: The results show that the usage of the proposed method for aberration correction can successfully increase the intensity and reduce the angular width of the ultrasound wave scattered by the point targets inside the phantoms. The method works with different distorting layers and is capable of correcting phase aberrations in multiple sections of the sonogram. The limitation of the proposed method consists in the fact that it requires the use of aperture synthesis and access to raw radiofrequency data, which restricts its application in common scanners. [ABSTRACT FROM AUTHOR]

Attentional control refers to the capacity to voluntarily control attentional resources in a flexible manner. Attentional control was reported to play a fundamental role in self-regulation, emotion regulation, delay of gratification, and psychological distress. The Attentional Control Scale (ACS) was developed to measure perceived attentional control based on shifting and focusing dimensions. The present studies aimed to adapt the Turkish version of ACS and asses its psychometric characteristics. Study 1 aimed to explore the psychometric qualities of the Turkish version with a group of Turkish individuals (N = 428, 306 women) between the ages of 18 and 68 and supported the two-factor model of ACS consisting of 17 items in total. The results supported that shifting, focusing, and total ACS showed adequate internal consistency, test-retest reliability, and convergent validity evidence based on its significant correlations with measures of anxiety, depression, and repetitive negative thinking, signifying its proper psychometric characteristics. In Study 2 (N = 97, 65 women), the association of ACS with behavioral attentional control measures was examined, and non-significant associations between self-report and behavioral measures of attentional control were denoted. These findings signified that rather than indicating the individual's actual attentional control capacity, ACS assessed how the individual perceives their own attention control capacities. Taken together, the results suggest that the Turkish form of ACS is a valid and reliable scale that can be used to assess perceived attentional control capacity based on shifting and focusing domains, particularly in the research setting. [ABSTRACT FROM AUTHOR]

The dynamics of two-dimensional waves in a water-filler pipe containing cluster of bubbles has been investigated. The waves are generated by a step-like increase in the pressure at one end of the pipe. The liquid with bubbles is described by a system of macroscopic equations of conservation of mass, bubble number, and momentum, as well as an equation of the pressure in the bubbles. A comparison with the case of the wave impact on a bubbly layer near the the pipe wall is also conducted. The dependence of the maximum pressure amplitude in the pipe on the bubbly cluster size and the initial volumetric gas content in the cluster is studied. A map of zones with maximum pressure in the pipe is constructed. The results show that besides the zone where the volumetric content is a determining factor, there is a zone where the size of the bubbly region play a crucial role. There is an optimal combination of the bubbly region size and the initial volumetric bubble content that ensures maximum pressure growth in the pipe. [ABSTRACT FROM AUTHOR]

IntroductionFocusing-Oriented Psychotherapy has had a long history and influence on the field of psychotherapy. By “clearing a space” and “focusing,” individuals can enhance their emotional awareness and improve their ability to self-regulate. These tasks are particularly relevant in the context of Psycho-Oncology, although the research on their potential benefits for cancer patients is limited. Furthermore, the application of these tasks in a group or online setting has not been thoroughly explored.MethodsThis study aimed to examine the effectiveness of a two-session online intervention based on Focusing for cancer-diagnosed participants and its impact on their mental health and wellbeing. The study involved three participants with a diagnosis of colorectal cancer who were undergoing palliative treatment. We used both qualitative and quantitative methods. PFC-2 was used to assess participants' accomplishment of the task; FMS was used to assess the change in the focusing attitude, while CORE-OM, and PWBS-RV were used as mental health distress and psychological wellbeing measures; participant feedback was collected through questionnaires and a semi-structured interview.ResultsThe results suggest that the tasks led to greater self-awareness, heightened self-reflection, and a sense of relief for the participants.DiscussionThese findings suggest that the group intervention protocol based on online Focusing sessions is potentially useful for broader applications.

Optical endoscopy has become an essential diagnostic and therapeutic approach in modern biomedicine for directly observing organs and tissues deep inside the human body, enabling non-invasive, rapid diagnosis and treatment. Optical fiber endoscopy is highly competitive among various endoscopic imaging techniques due to its high flexibility, compact structure, excellent resolution, and resistance to electromagnetic interference. Over the past decade, endoscopes based on a single multimode optical fiber (MMF) have attracted widespread research interest due to their potential to significantly reduce the footprint of optical fiber endoscopes and enhance imaging capabilities. In comparison with other imaging principles of MMF endoscopes, the scanning imaging method based on the wavefront shaping technique is highly developed and provides benefits including excellent imaging contrast, broad applicability to complex imaging scenarios, and good compatibility with various well-established scanning imaging modalities. In this review, various technical routes to achieve light focusing through MMF and procedures to conduct the scanning imaging of MMF endoscopes are introduced. The advancements in imaging performance enhancements, integrations of various imaging modalities with MMF scanning endoscopes, and applications are summarized. Challenges specific to this endoscopic imaging technology are analyzed, and potential remedies and avenues for future developments are discussed.

Physical features of spatial-energy characteristics of linearly polarized THz laser beams at sharp and moderate focusing in free space are analyzed both theoretically and experimentally. The Rayleigh-Sommerfeld vector theory is used to model propagation of laser beams excited by quasi-optical waveguide resonator modes in free space. Well-known methods of measuring spatial-energy characteristics of laser beams in the THz range are used in the experimental study. It is shown that the intensity of the total electric field of both combined TE0n + EH2n and EН-1n + EH3n modes (n = 1, 2, 3) in the focal region is defined by all three components and has a dip on the axis for both focusing types. The central maxima of the field of these modes become significantly shifted from the geometric foci of the lenses used as the order n of these modes increases. The EН-11 + EH31 mode has the smallest diameter (2.94λ) of the focal spot in the maximum intensity region at sharp focusing. The TE01 + EH21 mode has the smallest diameter (13.65λ) of the focal spot at moderate focusing. [ABSTRACT FROM AUTHOR]

Selective attention refers to the ability to focus on goal-relevant information while filtering out irrelevant information. In a multisensory context, how do people selectively attend to multiple inputs when making categorical decisions? Here, we examined the role of selective attention in cross-modal categorization in two experiments. In a speed categorization task, participants were asked to attend to visual or auditory targets and categorize them while ignoring other irrelevant stimuli. A response-time extended multinomial processing tree (RT-MPT) model was implemented to estimate the contribution of attentional focusing on task-relevant information and attentional filtering of distractors. The results indicated that the role of selective attention was modality-specific, with differences found in attentional focusing and filtering between visual and auditory modalities. Visual information could be focused on or filtered out more effectively, whereas auditory information was more difficult to filter out, causing greater interference with task-relevant performance. The findings suggest that selective attention plays a critical and differential role across modalities, which provides a novel and promising approach to understanding multisensory processing and attentional focusing and filtering mechanisms of categorical decision-making. [ABSTRACT FROM AUTHOR]

In this paper, diffraction of scalar waves by a screen with a circular aperture is explored, considering the incidence of either a collimated beam or a focused wave, a historical review of the development of the theory is presented, and the introduction of the Fresnel approximation is described. For diffraction by a focused wave, the general case is considered for both high numerical aperture and for finite values of the Fresnel number. One aim is to develop a theory based on the use of dimensionless optical coordinates that can help to determined the general behaviour and trends of different system parameters. An important phenomenon, the focal shift effect, is discussed as well. Explicit expressions are provided for focal shift and the peak intensity for different numerical apertures and Fresnel numbers. This is one application where the Rayleigh–Sommerfeld diffraction integrals provide inaccurate results. [ABSTRACT FROM AUTHOR]

We introduce the notion of limited consideration into a bilateral, infinite-horizon, alternating-offers bargaining game. Both agents have reference-dependent preferences, and their reference points are dynamically updated. An agent's current consideration set (or focus) is influenced by the last offer he rejected such that the most salient point in that consideration set becomes his current reference point. We provide an implicit characterization of stationary subgame perfect Nash equilibria in our model. Without resorting to asymmetric or incomplete information, we show that our bargaining game can produce delay and disagreement in equilibrium. In addition to analytical results on the disagreement conditions and the nature of agreements, we provide computational comparative statics on model parameters and study their impacts on delay. [ABSTRACT FROM AUTHOR]

The paper considers the possibility of forming the maximum amplitude of the electric field strength at a given point in space using a linear antenna array focused on a finite distance. Since the location of the electric field maximum does not coincide with the point at which the antenna array is focused, two methods have been proposed to ensure the positioning of the maximum at a given point. The first method is an algorithm that allows you to determine such a large focal length at which the maximum electric field strength is positioned at the required point. The second way is to use two parallel identical antenna arrays, equidistantly located relative to the desired location of the maximum electric field strength. The limitations imposed by each of the methods are considered. Examples of the use of each of the methods for positioning the maximum electric field strength at a given point are given. [ABSTRACT FROM AUTHOR]

This article presents the design of a dielectric lens antenna that utilizes the concept of a stepped Fresnel lens for focusing electromagnetic millimeter waves. Based on the quasi-optical properties of these waves, a Cartesian Oval is optimized and employed as a focusing lens. Multiple such lenses are combined to two different Fresnel-based lens antennas. We survey these newly designed lens antennas and compare them with a focusing lens antenna based on a Cartesian oval and a far-field lens antenna. Simulations and measurements with a frequency-modulated continuous-wave (FMCW) radar validate the effectiveness of the new design, demonstrating an even improved focus size while significantly reducing the size and weight of the lens antenna by up to 53% and by nearly 48 %, respectively. Additionally, the Fresnel-based lens antennas reveal a frequency dependency, enabling frequency-based steering of the focal length over a wide relative tuning range of 177%, which we thoroughly investigate for various bandwidths and center frequencies. [ABSTRACT FROM AUTHOR]

Comparative study of dialects invariably reveals interesting similarities and differences in the dialects of a language. In this regard, so much differences have been reported in the grammatical structure of the dialects of different languages that include Yorùbá. Such reports with respect to Yorùbá have not only enriched our understanding of the grammar of the language, they have also helped in clarifying controversial and/or obscure issues in the language. The present paper investigates the nature of focus constructions in two dialects of Yorùbá language: Mò͎bà and Mọ́yè͎e͎ with particular attention to the coding of focusing. The study investigates constituents that can be moved to effect focus construction, the focus markers, the overt and covert nature of the markers, and some phonological issues arising from the coding. The paper is descriptive in orientation. Data were collected from native speakers of the two dialects and relevant existing literatures. It is established in this paper that Mò͎bà and Mọ́yè͎e͎ manifest constituent and sentence focusing. Mò͎bà has two focus markers while Mọ́yè͎e͎ has one. The paper contributes to existing literature in the field of Yorùbá dialectology. [ABSTRACT FROM AUTHOR]

The utilization of spintronic terahertz (THz) emitters has a significant influence on broadband coherent spectroscopy and imaging at THz frequencies. By using femtosecond light to irradiate the spintronic heterostructures, spin currents from the ultrafast demagnetization effect can be transformed into charge currents through the inverse spin Hall effect, leading to the emission of THz waves. In this work, through the incorporation of sequential and inverse deposition of W‐Co20Fe60B20‐Pt heterostructure films, control is gained over the spin currents and THz waveforms, enabling it to achieve a 180° phase difference across a broad frequency spectrum while efficiently radiating THz waves. This, in turn, allows it to control the spatial phase of THz radiation. To test the device's capabilities, lithography‐based devices capable of focusing, producing vortexes, and dividing beams are manufactured. This investigation aims to advance the development of THz pulse sources while providing essential support for cutting‐edge technologies such as THz spectroscopy, high‐resolution imaging, and high‐speed communications. [ABSTRACT FROM AUTHOR]

The feasibility of application of a ferromagnetic conductive cylinder nozzle to focus the fluid flow extruded by a piston dispenser is assessed in the present work. Based on the limiting cases of stationary and laminar fluid flows, it is shown that an electric field can be created between the fluid and the cylindrical nozzle due to the anomalous Hall effect in the cylindrical nozzle with a current flowing along the cylinder. This field is created by the electric current caused by the mechanical movement of the fluid. This electric current of the fluid creates around itself the cylindrical magnetic field that penetrates into the ferromagnetic nozzle. On the example of carbonyl iron, it is shown with allowance for the corresponding approximations that an increase in the current flowing through the ferromagnetic nozzle should lead to a decrease of the fluid flow radius. [ABSTRACT FROM AUTHOR]

We test for a novel pattern of menu-dependent risk attitudes that forms the basis of recent theories of risky choice: Does expanding the range of potential prizes from lotteries in a choice set lead people to overweight those prizes and make riskier choices? Contrary to our hypothesis, we find no evidence of such a menu effect. Varying the potential prize offered by an actuarially unfavorable, high-risk lottery does not affect the likelihood of choosing a different, moderate-risk gamble in favor of a safer alternative. Our well-powered null results cast doubt on prominent theories of menu-dependent risk preferences. [ABSTRACT FROM AUTHOR]

The focused acoustic field formed under the water surface raised by ultrasound exposure was numerically investigated to elucidate the relationship with the surface rising prior to ultrasonic atomization. The effect of surface tension was newly added to the computational scheme constructed in the previous paper (Orisaki and Kajishima, 2022) and the direct numerical simulation based on compressible fluid dynamics was conducted. The water surface above the sound source rises. When the risen surface shape changes into a dome due to the effect of surface tension, the acoustic antinode with strong focusing appears inside the dome and the water surface begins to rise rapidly. In case of the insufficient sound source pressure, the gentle risen surface is kept, and acoustic peak spots remain deep due to the small curvature of the surface. These results suggest that the dome formation increases the acoustic pressure amplitude at the dome center and promotes acoustic cavitation there. On the dome surface, the kinetic energy density with the phase opposite to acoustic pressure increases, which causes the increase in the acoustic radiation pressure.

On X-ray beamlines and telescopes, glancing-incidence mirrors with parabolic profiles are used to collimate, focus, and collect light. Here, analytic descriptions for paraboloidal, plane-parabolic, and parabolic cylindrical mirrors in several congruent geometries that are commonly used in fabrication, metrology, and modeling are provided. The exact expressions are derived directly from Fermat's principle, without coordinate transformations, in several mirror-centered coordinate systems, including one with the surface tangent to the central point of intersection. Coefficients for a sixth-order polynomial series approximation are calculated for that coordinate system.

Ellipsoidal and plane-elliptical surfaces are widely used as reflective, point-to-point focusing elements in many optical systems, including X-ray optics. Here the classical optical path function approach of Fermat is applied to derive a closed-form expression for these surfaces that are uniquely described by the object and image distances and the angle of incidence at a point on a mirror surface. A compact description facilitates design, modeling, fabrication, and testing to arbitrary accuracy. Congruent surfaces in two useful coordinate systems - a system centered on the ellipsoid's axes of symmetry and a mirror-centered or `vertex' system with the surface tangent to the xy plane at the mirror's center - are presented. Expressions for the local slope and radii of curvature are derived from the result, and the first several terms of the Maclauren series expansion are provided about the mirror center.

Abstract Underwater images suffer from color distortion, low clarity and halos problems due to light absorption, particle scattering and non‐uniform illumination. To address these degradation issues, a multi‐cues underwater image restoration algorithm combined with light field technology is proposed. First, based on Epipolar Plane Image, the light field cue transmittance containing depth information is calculated. Then, according to the turbidity of the underwater image, the light field cue transmittance and the polarization cue transmittance are fused to obtain the multi‐cues transmittance, which can effectively reduce the effect of particle scattering and color bias. Finally, the background light is estimated through the all‐focus operation, which can effectively overcome the distortion of an underwater single image and simultaneously reduce the halo phenomenon. Experimental results show that the method achieves the best results evaluated by UCIQE, UIQM, PSNR, and SSIM, and the restored color under the method is closer to the actual image than other underwater restoration methods.

Background. The article considers cognitive mechanisms of the formation of the temporal meanings in the advertising tourist narrative. Relevance of the study is determined by its correlation with modern linguistic research aimed at studying linguistic semantics in its relationship with cognitive structures. Having a multicomponent structure, time is currently positioned as an attribute of human activity and also as a phenomenon of human existence. However, there is insufficient study of the interpretive potential of time, which makes research topic relevant. Purpose. The research purpose is as follows: to determine the cognitive mechanisms of the temporal organization of the advertising tourist narrative. Materials and methods. Language units of various levels were used for the study, obtained from authentic online texts of advertising tourist narrative. The main research methods include analysis and synthesis of theoretical material, the continuous sampling method, descriptive method, contextual analysis method as well as cognitive modeling method. Results. The results have shown that the main cognitive mechanisms of formation and interpretation of temporal meanings in the advertising tourist narrative include focusing, profiling, perspectivization, conceptual metaphor. Cognitive models of structuring temporal meanings, the source of which are the cognitive mechanisms outlined above, are considered. Practical implications. The research results can be used in the development of courses on general linguistics, lexicology and cognitive linguistics.

Based on the Richards-Wolf formalism, we obtain two different exact expressions for the angular momentum (AM) density in the focus of a vortex beam with the topological charge n and with right circular polarization. One expression for the AM density is derived as the cross product of the position vector and the Poynting vector and has a nonzero value at the focus for an arbitrary integer number n. The other expression for the AM density is deduced as a sum of the orbital angular momentum (OAM) and the spin angular momentum (SAM). We reveal that at the focus of the light field under analysis, the latter turns zero at n = –1. While both these expressions are not equal to each other at each point of space, 3D integrals thereof are equal. Thus, exact expressions are obtained for densities of AM, SAM and OAM at the focus of a vortex beam with right-hand circular polarization and the identity for the densities AM = SAM + OAM is shown to be violated. Besides, it is shown that the expressions for the strength vectors of the electric and magnetic fields near the sharp focus, obtained by adopting the Richards-Wolf formalism, are exact solutions of the Maxwell's equations. Thus, Richards–Wolf theory exactly describes the behavior of light near the sharp focus in free space.

Airborne circular synthetic aperture radar (CSAR) can realize high-resolution imaging of the scene over 360 degrees azimuth angle variation. Aiming at the problem of focusing of buildings for the airborne CSAR, this paper first analyzes the phase errors of CSAR buildings focusing in detail, and the analytic relationship between the scatterer height and azimuth focusing quality is deduced. Then, a focusing method of CSAR buildings based on the back projection algorithm is proposed. This method adopts the processing strategy of multi-layers imaging, and it is able to improve azimuth focusing quality of the buildings which have large height dimension. The proposed method is especially suitable for the high-resolution imaging and monitoring of the urban site with high-rise buildings in the airborne CSAR scenario. The correctness of the theoretical analysis and the validity of the proposed method are verified by using both simulation results and Ku-band airborne CSAR real data processing results. [ABSTRACT FROM AUTHOR]