Line Components Research Articles

Photospheric variability of the late B supergiant HD 199478

ABSTRACT We present the results of spectral studies of the photospheric lines of the late B supergiant HD 199478 (B8 Iae) in the visual range. The radial velocities of photospheric lines, as well as the emission component of the Hα line, demonstrate synchronous variations. The variations in the equivalent widths of the photospheric lines and the emission component of the Нα line tend to be anticorrelated. The parameters of the spectral lines vary quasi-periodically and are characterized by extrema. The time-scales between the nearby extrema are about 25 d, and the full cycle of the quasi-period is about 45 ± 10 d. The D Na i line profiles often exhibit signs of accretion of matter on to the star. It is shown that the observed photometric variability of the star can also be explained by radial pulsations.

Remote handling maintenance of beam dump in IFMIF-DONES

IFMIF-DONES aims at providing high-energy deuterons to produce a neutron flux to test materials. The accelerator stops the pulsed beam at a low duty cycle in the Beam Dump, which is a relevant component of the High Energy Beam Transport line. The cartridge of the Beam Dump absorbs a beam of charged particles during DONES accelerator commissioning and start-up phases after a shutdown. The cartridge is contained for security reasons in a shielding given its high activation, which remains for a long time. Deterioration of this component is due to heating cycles, radiation and corrosion caused by the cartridge cooling water. Thereby, Beam Dump has been classified as 3rd class Remote Handling component. It means that there is no scheduled maintenance for this component, but Remote Handling operations are required in case of failure. Remote equipment is mandatory when the Beam Dump shielding is open due to the high radiation levels. This work presents the maintenance operations to replace the Beam Dump cartridge. It includes the sequence and description of the procedures, equipment and tools necessary to meet the project requirements.

Real-Time Detection and Spatial Localization of Insulators for UAV Inspection Based on Binocular Stereo Vision

Unmanned aerial vehicles (UAVs) have become important tools for power transmission line inspection. Cameras installed on the platforms can efficiently obtain aerial images containing information about power equipment. However, most of the existing inspection systems cannot perform automatic real-time detection of transmission line components. In this paper, an automatic transmission line inspection system incorporating UAV remote sensing with binocular visual perception technology is developed to accurately detect and locate power equipment in real time. The system consists of a UAV module, embedded industrial computer, binocular visual perception module, and control and observation module. Insulators, which are key components in power transmission lines as well as fault-prone components, are selected as the detection targets. Insulator detection and spatial localization in aerial images with cluttered backgrounds are interesting but challenging tasks for an automatic transmission line inspection system. A two-stage strategy is proposed to achieve precise identification of insulators. First, candidate insulator regions are obtained based on RGB-D saliency detection. Then, the skeleton structure of candidate insulator regions is extracted. We implement a structure search to realize the final accurate detection of insulators. On the basis of insulator detection results, we further propose a real-time object spatial localization method that combines binocular stereo vision and a global positioning system (GPS). The longitude, latitude, and height of insulators are obtained through coordinate conversion based on the UAV’s real-time flight data and equipment parameters. Experiment results in the actual inspection environment (220 kV power transmission line) show that the presented system meets the requirement of robustness and accuracy of insulator detection and spatial localization in practical engineering.

Study of polarization strategy with two elliptical grating polarizers for ECRH systems

• The polarization strategy for ECRH systems with two elliptical grating polarizers was studied. • The polarization purity of the polarization strategy was analyzed. • The elliptical polarizer was tested at the low power experiment. The grating polarizer is a critical component in the millimeter-wave transmission line in an electron cyclotron resonance heating (ECRH) system, the main function of which is to change the polarization characteristics of the millimeter-wave. This paper presents an optimal polarization strategy for the millimeter-wave transmission line in an ECRH system. With two identical sinusoidal-groove elliptical grating polarizers, an arbitrary polarization can be realized. A special elliptical grating polarizer has thus been designed and its performance has been tested on a low power test bed. The results of the low power experiments agree well with the theoretical calculation values. The purity of the polarization achieved via the polarization strategy developed in this work has also been calculated and is found to be no less than 99.98 %. The analysis indicates that almost all the polarization states can be obtained by this polarization strategy.

Broadband Rotary Joint Concept for High-Power Radar Applications

To allow antenna movements in azimuth and elevation in high-power radar applications, rotary joints are essential. They allow the rotation of a transmission line and therefore are important transmission line components. In the present paper, a broadband rotary joint concept for high-power W-band radar applications is proposed. To avoid a twist of the polarization plane of a linearly polarized mode, like HE11, a combination of two broadband polarizer is used. A cross polarization of Xpol ≤ − 20 dB can be achieved within the considered frequency range from 90 GHz to 100 GHz. This corresponds to a suitable value for radar applications.

An improved Faster R-CNN for defect recognition of key components of transmission line.

In a national power grid system, it is necessary to keep transmission lines secure. Detection and identification must be regularly performed for transmission tower components. In this paper, we propose a defect recognition method for key components of transmission lines based on deep learning. First, based on the characteristics of the transmission line image, the defect images are preprocessed, and the defect dataset is created. Then, based on the TensorFlow platform and the traditional Faster R-CNN based on the R-CNN model, the concept-ResNet-v2 network is used as the basic feature extraction network to improve the network structure adjustment and parameter optimization. Through feature extraction, target location, and target classification of aerial transmission line defect images, a target detection model is obtained. The model improves the feature extraction on transmission line targets and small target component defects. The experimental results show that the proposed method can effectively identify the defects of key components of the transmission lines with a high accuracy of 98.65%.

Variance components in recombinant inbred lines of Tef [Eragrostis tef (Zucc.) Trotter L.]: Estimation and their implications in selection

Tef [Eragrostis tef (Zucc.) Trotter L.] is an indigenous and important cereal crop in Ethiopia. Its improvement is dependent on the presence and magnitude of genetic variation among traits in a giv...

An Insulator in Transmission Lines Recognition and Fault Detection Model Based on Improved Faster RCNN

Insulators are critical electric components in transmission lines. Recognizing insulators and detecting the faults timely and accurately is essential for maintaining the safety and stability of transmission lines. Traditional methods have low accuracy and poor applicability in insulator recognition and fault detection. An insulator recognition and fault detection model was proposed in the article aiming at improving the insulator recognition and fault detection accuracy. First, based on the faster region convolutional neural network (RCNN), the feature pyramid networks (FPNs) were used to improve the Faster RCNN model and locate the insulators with complex background image. Then, the target area was clipped to remove the redundant background noise, and the hue, saturation, and value (HSV) color space adaptive threshold algorithm was applied for image segmentation due to the influence of light, background noise, and shooting angle. Finally, line detection, image rotation, and vertical projection were used to finish the insulator fault detection. The experimental results show that the proposed insulator recognition and fault detection model can recognize the insulators and detect fault types with better accuracy and achieve a mean average precision (mAP) of 90.8% for glass insulators and 91.7% for composite insulators on the testing dataset. Additionally, the proposed method meets the intelligent inspection of insulator faults in transmission lines and has good engineering application value.

Dispersion properties of artifi cial topological insulators based on an infi nite double-periodic array of elliptical quartz elements

Subject and Purpose. Special features of all-dielectric electromagnetic analogues of topological insulators (TI) in the microwave range are considered, aiming at studying the influence of geometrical and constitutive parameters of TI elements on the dispersion properties of topological insulators based on a two-dimensional double-periodic array of dielectric elements. Methods and Methodology. The evaluation of dispersion properties and electromagnetic field spatial distribution patterns for topological insulators is performed using numerical simulation programs. Results. The electromagnetic analogue of a topological insulator based on a double-periodic array of elliptical quartz cylinders has been considered. By numerical simulation, it has been demonstrated that the electromagnetic properties of the structure are controllable by changing the quartz uniaxial anisotropy direction without any changes in other parameters. A combined topological insulator made up of two adjoining ones differing in shapes of their unit cells has been considered with the numerical demonstration that frequencies of surface states are controllable by choosing the quartz uniaxial anisotropy direction. It has been shown that it is at the interface of two different in shape unit cells that the electromagnetic field concentration at a surface state frequency takes place. Conclusion. A possibility has been demonstrated of controlling microwave electromagnetic properties of topological insulators by changing their geometric parameters and permittivity of the constituents. From a practical point of view, topological insulators can be used as components of microwave transmission lines and devices featuring very small propagation loss.

Нелинейная задача о межматериальной трещинепод воздействием волны сдвига

Solution of the problem for an interface crack under the action of a harmonic shear wave is presented. It is shown that the same problems solutions of other authors were performed without taking into account the crack faces contact, and results obtained indicate the interpenetration of the faces, that is not possible. Thus, it is proved that the problem is nonlinear because the positions and sizes of the contact zone are unknown and variable during the loading. The solution is obtained by the boundary integral equations method taking into account the contact interaction of the crack faces: using the Somigliana dynamic identity and the boundary equations arising from them, the transition from the two-dimensional problem to the equivalent problem at the boundaries of the domain is realized; the vector components in the boundary integral equations are presented by Fourier series, to prevent the interpenetration of the crack faces and the emergence of tensile forces in the contact zone the Signorini unilateral constraints are involved. The numerical solution is performed by the method of boundary elements with constant approximation of the problem parameters on an element. Numerical researches of the shear wave frequency influence onto the crack faces and adjoining surface displacements, opening and extent of crack faces contact zone are carried out. The quantitative difference between the maximum tangential and normal components of adhesion line and the crack faces displacements is shown. It is shown that the position and length of the contact area change during the load period, and the magnitudes of the contact forces vary along the crack length.

A Defect Detection Method for Rail Surface and Fasteners Based on Deep Convolutional Neural Network.

As a result of long-term pressure from train operations and direct exposure to the natural environment, rails, fasteners, and other components of railway track lines inevitably produce defects, which have a direct impact on the safety of train operations. In this study, a multiobject detection method based on deep convolutional neural network that can achieve nondestructive detection of rail surface and fastener defects is proposed. First, rails and fasteners on the railway track image are localized by the improved YOLOv5 framework. Then, the defect detection model based on Mask R-CNN is utilized to detect the surface defects of the rail and segment the defect area. Finally, the model based on ResNet framework is used to classify the state of the fasteners. To verify the robustness and effectiveness of our proposed method, we conduct experimental tests using the ballast and ballastless railway track images collected from Shijiazhuang-Taiyuan high-speed railway line. Through a variety of evaluation indexes to compare with other methods using deep learning algorithms, experimental results show that our method outperforms others in all stages and enables effective detection of rail surface and fasteners.

IN SEARCH OF A COLOR LINE

AbstractThis research examines laws in the colony of Virginia created by a powerful landowning planter class that attempted to draw a color line separating three descent groups: an indigenous native population (Indian), an immigrant population from Europe (English), and an imported population from Africa (Negro). Textual analysis of the Laws of Colonial Virginia shows that the English lawmakers had to learn they were the White component of a color line; they did not, for many years, refer to themselves as White. Contrary to some widely held views that race relations began as soon as these groups came into contact at some point in the seventeenth century, the analysis of written law suggests it took over 100 years, until near the middle third of the eighteenth century in Colonial Virginia, before a definitive concept of race was socially-constructed and a color line was drawn in Black and White.

Detection of damage sites on overhead power lines with a voltage of 110 kV or higher

The article is devoted to problems in the electric grid complex related to ageing of components of power lines, reduction of reliability and increase the number of failures. It shows the need of development of scientific and methodical bases of perfection of management and organization of the system of technical maintenance and repair of equipment in power network systems, taking into account the current state of development of the power industry. Problems of disconnections of high-voltage power lines occur periodically in many countries and the search for options for their early elimination or pre-termination is a very urgent task. Researching and developing methods and devices for early detection of fault locations will minimize the time for troubleshooting and thus reduce downtime and economic losses for all parties, both the grids organization and the electricity consumer. The paper presents the results of research and development of devices used to detect places of power line damage in the conditions of “digital transformation” of the energy complex. The implementation of the developed proposals will have a positive impact on reducing losses from under-supply of electricity and will reduce the time for identifying fault locations associated with determining the locations of short-circuit currents.

Overview of visual defect detection of transmission line components

Overview of visual defect detection of transmission line components

OUP accepted manuscript

We present an analysis of the galaxy environment and physical properties of a partial Lyman limit system at z = 0.83718 with HI and metal line components closely separated in redshift space ($|\Delta v| \approx 400$ km/s) towards the background quasar HE1003+0149. The HST/COS far-ultraviolet spectrum provides coverage of lines of oxygen ions from OI to OV. Comparison of observed spectral lines with synthetic profiles generated from Bayesian ionization modeling reveals the presence of two distinct gas phases in the absorbing medium. The low-ionization phase of the absorber has sub-solar metallicities (1/10-th solar) with indications of [C/O] < 0 in each of the components. The OIV and OV trace a more diffuse higher-ionization medium with predicted HI column densities that are $\approx 2$ dex lower. The quasar field observed with VLT/MUSE reveals three dwarf galaxies with stellar masses of $M^* \sim 10^{8} - 10^{9}$ M$_\odot$, and with star formation rates of $\approx 0.5 - 1$ M$_\odot$ yr$^{-1}$, at projected separations of $\rho/R_{\mathrm{vir}} \approx 1.8 - 3.0$ from the absorber. Over a wider field with projected proper separation of $\leq 5$ Mpc and radial velocity offset of $|\Delta v| \leq 1000$ km/s from the absorber, 21 more galaxies are identified in the $VLT$/VIMOS and Magellan deep galaxy redshift surveys, with 8 of them within $1$ Mpc and $500$ km/s, consistent with the line of sight penetrating a group of galaxies. The absorber presumably traces multiple phases of cool ($T \sim 10^4$ K) photoionized intragroup medium. The inferred [C/O] < 0 hints at preferential enrichment from core-collapse supernovae, with such gas displaced from one or more of the nearby galaxies, and confined to the group medium.

Multi Component Drill Jig for Brake Lining Component

The process of producing a perfect work holding device is of prime importance to any industry. The drill jig must be such that it conforms to all the factors of design and that is absolutely economical too. Our work is to design a Multi component drill jig for brake lining componentwhich will be an advanced way for producing the spring-hole drills in three various brake lining components in the same jig. The brake liner is an important component in automobile; hence for drilling a spring hole in brake lining component, drill jig is necessary. The drill jig that we have designed aims at solving the problem of replacing the jig each time a different component has to be drilled. The brake lining varies in size and a different jig produced for each component will increase the cost.This can be reduced by adopting this design for producing the drill hole in the brake lining. Mechanical slider is used alongside with jig to stack and load the liners. The jig is manufactured by processes like milling, grinding etc. Our project helps in reducing the cost of manufacture of the brake lining. It also reduces the time of production in a considerable way.

Atomic data for the Gaia-ESO Survey

Context. We describe the atomic and molecular data that were used for the abundance analyses of FGK-type stars carried out within the Gaia-ESO Public Spectroscopic Survey in the years 2012 to 2019. The Gaia-ESO Survey is one among several current and future stellar spectroscopic surveys producing abundances for Milky-Way stars on an industrial scale. Aims. We present an unprecedented effort to create a homogeneous common line list, which was used by several abundance analysis groups using different radiative transfer codes to calculate synthetic spectra and equivalent widths. The atomic data are accompanied by quality indicators and detailed references to the sources. The atomic and molecular data are made publicly available at the CDS. Methods. In general, experimental transition probabilities were preferred but theoretical values were also used. Astrophysical gf-values were avoided due to the model-dependence of such a procedure. For elements whose lines are significantly affected by a hyperfine structure or isotopic splitting, a concerted effort has been made to collate the necessary data for the individual line components. Synthetic stellar spectra calculated for the Sun and Arcturus were used to assess the blending properties of the lines. We also performed adetailed investigation of available data for line broadening due to collisions with neutral hydrogen atoms. Results. Among a subset of over 1300 lines of 35 elements in the wavelength ranges from 475 to 685 nm and from 850 to 895 nm, we identified about 200 lines of 24 species which have accurate gf-values and are free of blends in the spectra of the Sun and Arcturus. For the broadening due to collisions with neutral hydrogen, we recommend data based on Anstee-Barklem-O’Mara theory, where possible. We recommend avoiding lines of neutral species for which these are not available. Theoretical broadening data by R.L. Kurucz should be used for Sc II, Ti II, and Y II lines; additionally, for ionised rare-earth species, the Unsöld approximation with an enhancement factor of 1.5 for the line width can be used. Conclusions. The line list has proven to be a useful tool for abundance determinations based on the spectra obtained within the Gaia-ESO Survey, as well as other spectroscopic projects. Accuracies below 0.2 dex are regularly achieved, where part of the uncertainties are due to differences in the employed analysis methods. Desirable improvements in atomic data were identified for a number of species, most importantly Al I, S I, and Cr II, but also Na I, Si I, Ca II, and Ni I.

Further Empirical Evidence on Patrick Hughes' Reverspectives: A Pilot Study.

Reverspectives are paintings created by the English artist Patrick Hughes. They are 3D structures, for example, pyramids or prisms, which elicit an illusory depth perception that corresponds to the reverse of the physical depth layout. Rogers and Gyani state that “the perspective information provided by a simple grid of vertical and horizontal lines on a slanting surface can be just as powerful as the information provided by a rich, naturalistic scene”. The present experiment was aimed to further investigate this perspective reversal. Three independent variables were manipulated: (1) texture components (i.e., vertical, horizontal, and oblique lines components), (2) texture spatial arrangement (i.e., Hughes-type “perspective” grid vs. equidistant “no perspective” grid), and (3) illumination direction (i.e., homogeneous illumination, light from above, and light from below). The dependent variable was the “critical distance”, namely, the distance between an approaching observer and the stimulus at which the illusory depth perception of concavity/convexity switched to the actual perception of convexity/concavity. The results showed that a stronger illusion is elicited by: (a) a Hughes-type texture spatial arrangement; (b) a complete grid texture composition, having both vertical and horizontal, and oblique components; and (c) illumination from below, as opposed to the condition in which light is coming from above.

Detection of a High-Temperature Blackbody Hump in Black Hole Spectra. The strongly redshifted annihilation line

Abstract We detected a so called high-temperature blackbody (HBB) component, found in the 15 – 40 keV range, in the broad-band X-ray energy spectra of black hole (BH) candidate sources. A detailed study of this spectral feature is presented using data from five of the Galactic BH binaries, Cyg X–1, GX 339–4, GRS 1915+105, SS 433 and V4641 Sgr in the low/hard, intermediate, high/soft and very soft spectral states (LHS, IS, HSS and VSS, respectively) and spectral transitions between them using RXTE, INTEGRAL and BeppoSAX data. In order to fit the broad-band energy spectra of these sources we used an additive XSPEC model, composed of the Comptonization component and the Gaussian line component. In particular, we reveal that the IS spectra have the HBB component which color temperature, kTHBB is in the range of 4.5 – 5.9 keV. This HBB feature has been detected in some spectra of these five sources only in the IS (for the photon index Γ &amp;gt; 1.9) using different X-ray telescopes. We also demonstrate that a timescale of the HBB-feature is of orders of magnitude shorter than the timescale of the iron line and its edge. That leads us to conclude that these spectral features are formed in geometrically different parts of the source and which are not connected to each other. Laurent &amp; Titarchuk (2018) demonstrated a presence of a gravitational redshifted annihilation line emission in a BH using the Monte-Carlo simulations and therefore the observed HBB hump leads us to suggest this feature is a gravitational redshifted annihilation line observed in these black holes.

Identificación, representación descriptiva y evaluación archivísticas a partir de imágenes digitalizadas de documentos microfilmados que integran los llamados Archivos Berrutti del Ministerio de Defensa Nacional del Uruguay

It presents the project Archival identification of types and documentary series from digitized images of microfilmed documents that make up the so-called Berrutti Archives, which arises from the research activities in the area of ​​archival science carried out at the Faculty of Information and Communication of the University of the Republic of Uruguay. It constitutes a component of the Digital Research Resources research line, as it shows interest in the typology of digital information resources. The objective is to propose guidelines from archival research for the treatment of identification, descriptive representation and evaluation of the digitized images of microfilmed documents that make up the Berrutti Archives of the Ministry of National Defense of Uruguay. The defined methodology presents a qualitative, exploratory and descriptive approach appropriate to meet the objectives set. The results of the research are intended to provide an archival approach with the development of specific functions on a documentary grouping with special characteristics.