Spiral Components Research Articles

Numerical Investigation of the Heat Transfer Characteristics of Liquid Lithium Metal in Spiral Tubes

Abstract The application of liquid lithium as a coolant for the forthcoming era of space nuclear reactors exhibits significant potential, and spiral tube heat exchanger components are commonly used in steam generators for reactors. However, the heat transfer characteristics of liquid lithium in spiral tubes are not yet fully understood. This research establishes a non-isothermal heat transfer model incorporating a modified turbulent Prandtl number to analyze the flow of liquid lithium through spiral tubes with varying geometries. Numerical analysis is carried out focusing on the influence of inlet velocity, the distribution of related parameters, and the geometry of spiral tubes. The results demonstrate that in the range of the dimensionless Dean number 8165–13,063, the Nusselt number and the pressure drop present approximately linear relations with the Dean number. For the distribution law of relevant physical quantities, the inner side of the tube displays an eye-anatomy low-flowrate area and a high-temperature area, while a low-pressure area forms on the inner pipe wall. Finally, the pitch and spiral radius are found to be reduced as much as possible to ensure high liquid lithium-based heat transfer performance with a small pressure drop. The optimized design parameters reveal that within the actual design range of non-dimensional pitch of 0.667–10.667 and curvature of 0.0556–0.1667, the non-dimensional pitch and curvature are 0.667–2.667 and 0.1667, respectively. This study offers valuable insights into the heat transfer properties of liquid lithium within heat exchangers of the spiral tube design, promoting its application in space nuclear reactor power supply.

Enhancing feature selection with GMSMFO: A global optimization algorithm for machine learning with application to intrusion detection

Abstract The paper addresses the limitations of the Moth-Flame Optimization (MFO) algorithm, a meta-heuristic used to solve optimization problems. The MFO algorithm, which employs moths' transverse orientation navigation technique, has been used to generate solutions for such problems. However, the performance of MFO is dependent on the flame production and spiral search components, and the search mechanism could still be improved concerning the diversity of flames and the moths' ability to find solutions. The authors propose a revised version called GMSMFO, which uses a Novel Gaussian mutation mechanism and shrink MFO to enhance population diversity and balance exploration and exploitation capabilities. The study evaluates the performance of GMSMFO using the CEC 2017 benchmark and 20 datasets, including a high-dimensional intrusion detection system dataset. The proposed algorithm is compared to other advanced metaheuristics, and its performance is evaluated using statistical tests such as Friedman and Wilcoxon rank-sum. The study shows that GMSMFO is highly competitive and frequently superior to other algorithms. It can identify the ideal feature subset, improving classification accuracy and reducing the number of features used. The main contribution of this research paper includes the improvement of the exploration/exploitation balance and the expansion of the local search. The ranging controller and Gaussian mutation enhance navigation and diversity. The research paper compares GMSMFO with traditional and advanced metaheuristic algorithms on 29 benchmarks and its application to binary feature selection on 20 benchmarks, including intrusion detection systems. The statistical tests (Wilcoxon rank-sum and Friedman) evaluate the performance of GMSMFO compared to other algorithms. The algorithm source code is available at https://github.com/MohammedQaraad/GMSMFO-algorithm.

Instability of skyrmion lattice under microwave magnetic field due to single-q helimagnetic excitation mode

Composed of the three spiral magnetic vectors, the structure of skyrmion lattice (SkL) can be destructed by spin excitations in possibly two ways: one is to make decoherence of all the helices through the phase change of a certain spiral magnetic vector, and the other is to inhibit one or two spiral components while enhancing the others so that it becomes a magnetic structure of single or double magnetic vectors. Here, we present a micromagnetic study on the spin excitations of a two-dimensional SkL under the in-plane microwave magnetic field. By calculating the parameters describing the in-plane spin excitations mode, we find that the spin configuration tends to be an enhanced single-vector spiral magnetic structure due to the excitation modes under some specific frequencies so that the SkL will collapse to the topologically trivial state. Our results help to form a deeper understanding of the spin excitation in SkL under an ac magnetic field.

Analisis Penyebab Kerusakan Head Truck-B44 Menggunakan Metode FMEA dan FTA (Studi Kasus : PT. Bima, Site Pelabuhan Berlian)

A company if wants to survive in the face of the era of globalization is required to improve the quality of service continuously. PT. BIMA is a company engaged in maintenance and port equipment providers. In the service process, PT. Bima has 5 types of transport aircraft, but the most number of units and often used to operate is the head truck. Based on the history data, there are B44 head truck units, often damage problems in several parts, namely damage to Accu, Tire, Coupling, Hose Spiral and Separator components. The purpose to identify the type of damage that occurred, conduct an assessment which is then continued analysis of the FTA method to find out the factors that cause damage and provide recommendations. The results showed that with fmea analysis it was found the type of damage that had the largest RPN value score was the type of damage to the head truck-B44 unit in the accu section which had a RPN value of 181. While the results of the FTA analysis found that the cause of damage to the accu drop was the use of overtime units, damaged accu clamps, pull accu and preventive maintenance intervals were less accurate.

Six-axis free bending and twisting analysis of spiral square tube

Six-axis free bending and twisting (6FBT) technology enables the integral forming of square tube components with complex shapes. However, the process analysis method and the deformation behavior of square tube spiral components in the bending and twisting process have not been investigated. In this paper, an analytical model of the bending die trajectory suitable for one-time forming of square tube spiral components is proposed and verified by FE simulations and experiments. In this model, the bending direction of the component axis is changed continuously by adding an additional cross section torsion angle in the bending process of the square tube, and then the spiral member is formed. This paper further reveals the laws of stress, strain, wall thickness distribution and cross section distortion of 304 stainless steel square tube spiral components in the 6FBT process. The results show that during the forming process, the equivalent stress on the edge of the square tube is greater than that on the surface, the wall thickness reduction on each cross section only occurs on the outside of the bent, and the section distortion between the inside and outside of the bent is larger than that between the inside and outside of the twist.

Orbital angular momentum mode detection of the combined vortex beam generated by coherent combining technology.

Coherent beam combining (CBC) technology has distinct advantages in generating high power vortex beam. In this paper, a circularly arranged coherent beam array (CBA) with discrete vortex phases is constructed to generate vortex beams. We demonstrated that the combined vortex beam (CVB) generated by the CBA is a multiplexing vortices optical field, which sidelobe is the coaxial interference pattern of these spiral harmonic components. Using the designed Dammam vortex grating (DVG), the orbital angular momentum (OAM) spectrum of the CVB is detected. Moreover, taking the target OAM mode purity of the CVB as the evaluation function of active phase control system, we realized the closed-loop phase control of the CBA and obtained the phase-locked output of the CVB.

Insights into magnetoelectric coupling mechanism of the room-temperature multiferroic Sr3Co2Fe24O41 from domain observation

The mechanism of a magnetoelectric coupling in a room-temperature multiferroic, $\mathrm{S}{\mathrm{r}}_{3}\mathrm{C}{\mathrm{o}}_{2}\mathrm{F}{\mathrm{e}}_{24}{\mathrm{O}}_{41}$, with the Z-type hexaferrite structure, is examined by three approaches: observations of domain structures and their field responses, measurements of magnetic-field effect on electric polarization, i.e., magnetoelectric effect, and phenomenological discussions on the interplay among coexisting order parameters. With use of a resonant soft x-ray microdiffraction technique, we visualized magnetic-field responses of two types of magnetic domains ascribed to ferrimagnetic and spiral components inherent in a transverse conical magnetic structure of the hexaferrite. A simultaneous inversion of these magnetic domains by a magnetic-field reversal was observed, meaning that the process of a magnetization reversal corresponds to a 180\ifmmode^\circ\else\textdegree\fi{} rotation of the cone axis. The reversal process of the magnetic structure, together with experimental results of the magnetoelectric effect, leads us to the conclusion that the magnetoelectricity in the Z-type hexaferrite originates mainly from the spin-dependent metal-ligand orbital hybridization, with minor contribution from the asymmetric spin-exchange interaction. Furthermore, such a mechanism is discussed by the symmetry analysis based on the Landau theory and is well described in terms of couplings among the coexisting order parameters included in the free energy. Thus, observations on field responses of multiple domains in multiferroics provide insights into underlying microscopic magnetoelectric coupling mechanisms.

Introduction to The Spiral Dynamics and The Spiral Coriolis Force

The spiral dynamics of a point-like body of mass m in spiral differential geometry are introduced. New ideal motions have been studied, the uniform spiral motion and the uniform spiral-polar motion. The analysis is proposed by comparing the ideal spiral motions with the ideal circular motions. The theoretical forces acting on a point-like body of mass m moving in spiral frames were analyzed. The spiral and polar components of the Coriolis forces were compared.

Axially Symmetric Solution of the Weyl–Dirac Theory of Gravitation and the Problem of Rotation Curves of Galaxies

On the basis of the Poincare´–Weyl gauge theory of gravitation, a new conformal Weyl–Dirac theory of gravitation was proposed, formulated in Cartan–Weyl space-time with the Dirac scalar field representing a model of dark matter. A static approximate axially symmetric solution of the field equations in vacuum is obtained. On the basis of this solution, in the Newtonian approximation we consider the problem of rotation velocities in the spiral components of galaxies.

Direct laser printing of chiral plasmonic nanojets by vortex beams

Donut-shaped laser radiation, carrying orbital angular momentum, namely optical vortex, was recently shown to provide vectorial mass transfer, twisting transiently molten material and producing chiral micro-scale structures on surfaces of different bulk materials upon their resolidification. In this paper, we show that nanosecond laser vortices can produce chiral nanoneedles (nanojets) of variable size on thin films of such plasmonic materials, as silver and gold films, covering thermally insulating substrates. These results suggest optical interference of the incident and reflected laser beams as a source of complex surface intensity distributions in metal films, possessing spiral components and driving both center-symmetric and spiral thermocapillary melt flows to yield in frozen nanoneedles with their pre-determined spiral nanocarving.

Dynamic torsional characteristics of mine hoisting rope and its internal spiral components

Dynamic torsional characteristics of mine hoisting rope and its internal spiral components were investigated in the present study. Theoretical models of tensions of rope segments at distinct locations were presented to obtain dynamic rope tensions. Theoretical models of torque, unit torsion angle, torsion angle, twisting parameters, and torsional stress were introduced to investigate dynamic torsional characteristics of hoisting rope and its internal spiral components under tension. Rope tests were conducted in order to validate dynamic torsional properties of the rope under fluctuation tensions. The results show three-stage fluctuating trends of rope tension and torque. An increase of hoisting time induces a decreased torsion angle of the rope, fluctuating upward trends of unit torsion angles of the rope, spiral strands and steel wires, respectively, fluctuating increases in lay angles of the spiral strand and steel wires, respectively, and the fluctuating decreased lay length of the spiral strand. An increase of the distance between rope segment and friction pulley tangent causes a decrease at first and then an increase in the unit torsion angle in cases of the rope, spiral strands and steel wires, an increase at first and then a decrease in the rope torsion angle, increased lay angle and decreased lay length of the spiral strand, a decrease at first and then an increase in the torsional stress of steel wire in every layer of the spiral strand.

Magnetic Robot and Manipulation for Active-Locomotion With Targeted Drug Release

In this paper, we propose a new mechanism for targeted drug release based on active locomotion. The manipulating method is a magnetic torque control based on a rotating magnetic field using a three-axis Helmholtz coil system. The applied magnetic field creates two rolling (radial and longitudinal directions) and a rotating motion for active locomotion according to variations in the working space and robot posture. Two spiral components in the robot mechanism and the rotating motion completely conduct and control the drug release. Magnetic attractive force between the two spiral components prevents drug leakage during the movement for targeting. When the robot arrives at the destination, the robot switches the direction of the thrust force of the two spiral components to separate the robot body for the drug release. The thrust force for the drug release is higher than the magnetic attractive force. We verified the rapid active locomotion and targeted drug release using precise control through various experiments. In our assessment, the proposed robot mechanism can realize the role of a functional medical robot for therapy and diagnosis.

On Mixing Fingerprints

This work explores the possibility of mixing two different fingerprints, pertaining to two different fingers, at the image level in order to generate a new fingerprint. To mix two fingerprints, each fingerprint pattern is decomposed into two different components, viz., the continuous and spiral components. After prealigning the components of each fingerprint, the continuous component of one fingerprint is combined with the spiral component of the other fingerprint. Experiments on the West Virginia University (WVU) and FVC2002 datasets show that mixing fingerprints has several benefits: (a) it can be used to generate virtual identities from two different fingers; (b) it can be used to obscure the information present in an individual's fingerprint image prior to storing it in a central database; and (c) it can be used to generate a cancelable fingerprint template, i.e., the template can be reset if the mixed fingerprint is compromised.

SED DECOMPOSITION OF INFRARED-LUMINOUS GALAXIES

We select infrared-luminous galaxies by cross-matching the SDSS spectroscopic sample of galaxies with the WISE all-sky survey catalog. Based on photometric data points covering from SDSS u-band to WISE , their spectral energy distributions (SEDs) are separated into AGN, elliptical, spiral, and irregular galaxy components. The derived luminosities of spiral galaxy and AGN are well correlated with and [OIII] line luminosities, respectively. Most galaxies are dominated by young stellar populations even for optical AGNs, but at least 10% of optical non-AGNs appear to harbor buried AGNs. The AGN contribution increases dramatically with the total luminosity. These results show that the SED decomposition is successful and is useful to understand the true nature of dusty galaxies.

Enhancing foam drainage by spiral internal components of different thread pitches and inclined angles and their applications to enrichment of SDS

For further enhancing foam drainage and comprehensive knowledge of the spiral internal component (SIC), the effects of its thread pitch and inclined angle were experimentally and theoretically investigated. The results showed that the decrease of the thread pitch, and the increase of the inclined angle contributed to more enhancement of foam drainage. Under batch conditions, the SDS enrichment ratio obtained with SIC of thread pitch 30mm and inclined angle 30° was about 2.4 times of that obtained without SIC. The theoretical analyses predicted the liquid holdup distribution in the column with SIC and gave better explanations for the experimental results. It is found that the decrease of the thread pitch resulted in a larger number of the SIC units by which the more enhanced foam drainage was obtained. The increase of the inclined angle sped the reflux of the drained liquid, thus leading to faster decrease of the liquid holdup. However, the inclined angle had the weaker ability to enhance foam drainage than the thread pitch.

Abstract No. 310: Comparison of delivered radiation dose between C-arm CT and conventional spiral CT components of hybrid fluoroscopy units used for interventional radiology procedures

Abstract No. 310: Comparison of delivered radiation dose between C-arm CT and conventional spiral CT components of hybrid fluoroscopy units used for interventional radiology procedures

POMD13 Distinguishing tremor-dominant Parkinson's disease from tremulous subjects without evidence of dopaminergic deficit by spirography: an FP-CIT validated study

Five to fifteen per cent of de novo patients recruited for recent clinical trials of anti-parkinsonian drugs had no evidence of nigrostriatal dopamine denervation on functional imaging. These diagnostically challenging...

Fourier photometric analysis of isolated galaxies in the context of the AMIGA project

We present the results of a Fourier photometric decomposition of a representative sample of ~100 isolated Sb-Sc CIG/AMIGA galaxies. It complements the analysis presented in Durbala et al. 2008 for the same sample by allowing a description of the spiral structure morphology. We estimate dynamical measures like torque strength for bar and spiral, and also the total nonaxisymmetric torque. We explore the interplay between the spiral and bar components of galaxies. Both the length and the contrast of the Fourier bars decrease along the morphological sequence Sb-Sbc-Sc, with bars in earlier types being longer and showing higher contrast. Bars of Sb galaxies are ~3x longer than bars in Sc types. We find that longer bars are not necessarily stronger (as quantified by the torque Q_{b} measure), but longer bars show a higher contrast, in very good agreement with theoretical predictions. Our data suggests that bar and spiral components are rather independent in the sense that the torque strengths of the two components are not correlated. The total strength Q_{g} is a very reliable tracer of the bar strength Q_{b}, the two quantities showing a very tight linear correlation. Comparison with a similar sample of disk galaxies extracted from the OSUBGS indicates that the isolated CIG/AMIGA galaxies host significantly longer Fourier bars and possibly show a different distribution of spiral torque Q_{s}. The Fourier analysis also revealed a potential case of counterwinding spiral structure (NGC 5768), which deserves further kinematic study. We find that m = 2 (i.e., dominating two-armed pattern) is the most common spiral arm multiplicity among the sample of Sb-Sc CIG/AMIGA galaxies (~40%), m = 2&3 and m = 1&2 are found in ~28% and ~13% of isolated galaxies, respectively.

A simple method of measuring differentially-excited on-wafer spiral inductor-like components

This paper proposes a simple method of measuring differentially-excited on-wafer RF CMOS spiral inductor-like components. This method requires only two common ‘G-S-G’ probes and an ordinary two-port VNA. Using a network instead of a detailed equivalent circuit, this method completes the de-embedding with only one ‘Through’ dummy, and thus the measurements are greatly simplified. By designing the ports ‘Open’ or ‘Short-circuited’ deliberately, a multi-port transformer can be transformed into three two-port networks with different terminators. Then, couplings between the two coils can be solved, and the differentially-excited scattering parameters (S-parameters) can be constructed. Also, a group of differential inductors and transformers were designed and measured, and then comparisons between simulated and measured electromagnetic results are performed to verify this method.

Percutaneous Temporal Wiring Method for Minimally Invasive Plate Osteosynthesis of a Distal Tibial Fracture

Reduction of distal tibial fractures-especially fractures that include an oblique or spiral fracture component-during operative treatment with minimally invasive plate osteosynthesis is not always easy. Unexpected and unacceptable displacement can sometimes be seen after plate fixation. We designed an effective fracture reduction method involving a percutaneous temporal wiring technique for the reduction of distal tibial fractures, including fractures that contain oblique or spiral fracture components, during the minimally invasive plate osteosynthesis procedure. Our method can consistently accomplish satisfactory reduction of these fractures and easily maintain reduced fractures, fix the plate, reduce the level of radiation exposure during the operation.