2,861 Results Found

A curve with single-signed, monotonically increasing or decreasing curvatures is referred to as a planar spiral. $G^2$ Hermite data are spiral $G^2$ Hermite data for which only interpolation by a spiral is possible. In this study, we design segmented spira...

The paper aims to extend the classical two-dimensional (2D) Fibonacci spiral into three-dimensional (3D) space by using geometric constructions starting from cubic Fibonacci identities and relying on affine maps and parametrizations of the curves. We...

This work is intended to directly supplement the previous work by Coutsias and Kazarinoff on the foundational understanding of lacunary trigonometric systems and their relation to the Fresnel integrals, specifically the Cornu spirals [Physica 26D (19...

This paper presents a comprehensive study focused on evaluating the strain generated within short concrete columns reinforced with glass-fiber-reinforced polymer (GFRP) bars and spirals under concentric compressive axial loads. This research was moti...

The complex Bernoulli spiral is connected to Grandi curves and Chebyshev polynomials. In this framework, pseudo-Chebyshev polynomials are introduced, and some of their properties are borrowed to form classical trigonometric identities; in particular,...

Sustainability has to penetrate more and more into higher education. It should not focus only on traditional elements. It should also enter new, but for future improvement, extremely important areas. Based on this premise, creativity and motivation,...

Glass fiber-reinforced polymer (GFRP) composites offer a compelling solution to the durability degradation of reinforced concrete (RC) structures in harsh marine and de-icing environments. Hybridizing fiber-reinforced polymer (FRP) with conventional...

Inspired by the concept of antennas in electromagnetics, this study proposes a novel acoustic metamaterial using Archimedean spiral structures. Unlike traditional resonant absorption structures, the present structure does not rely on resonant cavitie...

In order to achieve the dual needs of single-phase vibration reduction and lightweight, a square honeycomb acoustic metamaterials with local resonant Archimedean spirals (SHAMLRAS) is proposed. The independent geometry parameters of SHAMLRAS structur...

This paper presents the experimental results and analytical modeling of the axial compressive behavior of concrete cylinders confined by both glass fiber-reinforced polymer (GFRP) tube and inner steel spiral reinforcement (SR). The concrete structur...

The usage of unmanned aerial vehicles (UAV) has increased in recent years and new application scenarios have emerged. Some of them involve tasks that require a high degree of autonomy, leading to increasingly complex systems. In order for a robot to...

Hexagonal order and golden-angle spirals are two of the most persistent geometric motifs in natural growth, and they also guide engineered systems that pack, route, or sense from a central source. This paper develops a two-objective account of their...

This paper presents the results of a study of the ordering in polyethylene terephthalate (PET) film induced by Ar⁸⁺ ions with an irradiation fluence of 2 × 10¹² ions/cm², and of the temporal stability of the induced ordering in the irradiated s...

Glass fiber-reinforced polymer (GFRP) reinforcements are useful alternatives to traditional steel bars in concrete structures, particularly in vertical structural elements such as columns, as they are less prone to corrosion, and impart increasing st...

We present the MATLAB code Spirality, a novel method for measuring spiral arm pitch angles by fitting galaxy images to spiral templates of known pitch. Computation time is typically on the order of 2 min per galaxy, assuming 8 GB of working memory. W...

Parkinson’s disease (PD) is a progressive neurodegenerative disorder whose early symptoms, especially mild tremor, are often clinically imperceptible. Early detection is crucial for initiating neuroprotective interventions to slow dopaminergic...

The middle trough of spirals serves simultaneously as a buffer zone for variations in hydrodynamic parameters and as a region where mineral particles of different densities are prone to mixing, exerting a profound influence on particle-separation eff...

Underwater acoustic spiral sources can generate spiral acoustic fields where the phase depends on the bearing angle. This allows estimating the bearing angle of a single hydrophone relative to a single source and implementing localization equipment,...

This paper comprehensively reviews the spiral dynamics optimization (SDO) algorithm and investigates its characteristics. SDO algorithm is one of the most straightforward physics-based optimization algorithms and is successfully applied in various br...

A visual graphic called Spiral Strip is presented consisting of color-coded segments arranged in a spiral. The width and length of each individual segment can be different, which can be used to convey additional information (besides the color coding)...

To realize the electrochemical etching of a micro spiral cylindrical electrode, a new method of rotating electrochemical etching is proposed, and its process is further studied. First, according to the electrochemical etching principle, the machining...

We present a neutron guide which is curved in the shape of a logarithmic spiral. Simulations and calculations for such a spiral guide are presented and the potential use of the guide for a reflectometer is investigated and compared to the conventiona...

In this paper, a new method to calculate the self-inductance of the Archimedean spiral coil is presented. The proposed method is derived by solving Neumann’s integral formula, and the numerical tool is used to calculate the inductance value. Th...

We analyze three nearby spiral galaxies—NGC 1097, NGC 1566, and NGC 3627—using images from the DustPedia database in seven infrared bands (3.6, 8, 24, 70, 100, 160, and 250 μm). For each image, we perform photometric decomposition and...

The traditional approach to the interpretation of spirals observed in radar, optical and radiometric panoramas of a sea surface is based on equating the outer spiral scale with the scale of a manifesting eddy, but the validity of this approach has be...

A low-cost high-efficiency ultra-wideband (UWB) cavity-backed spiral antenna is proposed. It employs an equiangular spiral enclosed by an Archimedean spiral and it is fed through a tapered microstrip balun. A center-raised cylindrical absorber-free c...

We report a novel broadband slot-spiral antenna that can be integrated with high-electron-mobility transistor (HEMT) terahertz (THz) detectors. The effect of various antenna parameters on the transmission efficiency of the slot-spiral structure at 15...

In this paper, we propose a terahertz (THz) spiral spatial filtering (SSF) imaging method that can enable image contrast enhancement. The related theory includes three main steps: (1) the THz image of the target is Fourier transformed to the spatial...

What are the mechanisms by which groups with certain opinions gain public voice and force others holding a different view into silence? Furthermore, how does social media play into this? Drawing on neuroscientific insights into the processing of soci...

In this paper, we characterize the helical beam structure through an analysis of the spiral character of the phase distribution inside a light beam. In particular, we show that a line connected with the 2π phase jump in the Laguerre–Gauss be...

There are four types of bubble ascent paths: rectilinear, zigzag, spiral, and chaotic, but fewer quantitative studies on the dynamics of bubble spiral motion. In this paper, the spiral path dynamics of a single bubble with an initial diameter of 1.75...

Here, we have reviewed some typical plasmonic structures based on Archimedes’ spiral (AS) architectures, which can produce polarization-sensitive focusing phenomenon and generate plasmonic vortices (PVs) carrying controllable orbital angular momentum...

An important goal in cardiology and other fields is to identify and control dynamic spiral wave patterns in reaction–diffusion partial differential equations. This research focuses on the Barkley model. The spiral wave motion is controlled and...

Linear Hashing is an important algorithm for many key-value stores in main memory. Spiral Storage was invented to overcome the poor fringe behavior of Linear Hashing, but after an influential study by Larson, it seems to have been discarded. Since al...

Spirals, tilings, and hyperbolic geometry are important mathematical topics with outstanding aesthetic elements. Nonetheless, research on their aesthetic visualization is extremely limited. In this paper, we give a simple method for creating Escher-l...

A spiral sound wave transducer comprised of longitudinal vibrating elements has been proposed. This transducer was made from eight uniform radial distributed longitudinal vibrating elements, which could effectively generate low frequency underwater a...

While spiral galaxies observed from Earth clearly seem to spin in different directions, little is yet known about other differences between galaxies that spin clockwise and galaxies that spin counterclockwise. Here we compared the color of 64,399 spi...

In addition to classical steroids, which have cholesterol as a precursor, there are steroids with 7-dehydrocholesterol as a precursor. This review describes the identification of these steroids, their biosynthesis, and some aspects of their function....

This paper presents the mathematical modeling, fluid dynamic analysis, and experimental analysis of a spiral case without guide vanes. Using a specific case of the Archimedes spiral, the model eliminates the need for fixed or moving blades to simplif...

In this paper, an analytical calculation of the inductance of an air-core planar spiral coil is presented. The inner and outer radius of the planar spiral coil is determined from the general equation of the filament of the wire. Using the Neumann int...

The dynamic migration of mineral particles within spiral separators and its control via structural parameters are not yet fully understood, hindering efficiency improvements. To this end, a set of spiral separators with systematically adjusted struct...

Parkinson’s disease is a neurodegenerative disease that often comes with symptoms such as muscle stiffness, slowness of movement, and tremors at rest. Since this disease negatively influences the quality of life in patients, an early and accura...

We analyse the influence of spiral dislocation topology on the revival time for the harmonic oscillator, for a particle confined to one-dimensional quantum ring, and a two-dimensional quantum ring. We first investigate the effects of a cut-off point...

Spiral arms are a common feature of local galaxies, but the exact form of the distribution of mass and light in them is not well known. In this work, we aim to measure this distribution as accurately as possible, focusing on individual spiral arms an...

We developed and investigated a particular geometry of transducers, emulating the shape of bats’ cochlea, to transmit and receive ultrasounds in the air. Their design involved the use of polyvinylidene fluoride (PVDF) as a piezoelectric materia...

This paper proposes a novel spiral-wound, optic-fiber sensor to monitor the corrosion of steel bars. At the same time, the winding parameters, such as winding angle and pitch, were first theoretically deduced. Then, to decrease light loss, a practica...

We examine the spiral structure of the thinking and the work of Marshall McLuhan, which we believe will provide a new way of viewing McLuhan’s work. In particular, we believe that the way he reversed figure and ground, reversed content and medium, re...

In order to solve the problem of inadequate confinement provided by traditional rectangular stirrups in concrete square columns under stringent seismic fortification requirements, a spiral stirrup with a better constraint effect was used in the squar...

In this study, the proposed bandpass filter (BPF) connects an interdigital and a spiral capacitor in series between the two symmetrical halves of a circular intertwined spiral inductor. For the mass production of devices and to achieve a higher accur...

Orthoplanar springs are single-component compliant mechanisms that can be fabricated from sheet material and undergo deflection orthogonal to the plane of the mechanism. They are useful in applications where spatial constraints are significant. An Eu...