Journal articles: 'Wire grids'

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Новиков, Yu Novikov, Спиридонов, V. Spiridonov, Большаков, and Vadim Bolshakov. "Operational Characteristics of Filtering Partitions from Wire Grids with Cells of Micron Sizes." Safety in Technosphere 2, no. 6 (December 25, 2013): 52–57. http://dx.doi.org/10.12737/2163.

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Results of pilot studies related to hydraulic resistance of wire woven grids with cells of micron sizes in laminar mode of a filtration have been presented. For assessment of grids hydraulic resistance the permeability coefficient value has been used. To overcome the effect of a large-scale factor on conducted researches results the dimensionless size of this parameter in the form of permeability coefficient relation to a square of the grid cell size is entered. The researches have been conducted on free-flow hydraulic installation by specially developed technique providing high precision determination of this parameter. Influence like wires interlacing at a size of dimensionless coefficient of permeability is established. Nature of influence like wires interlacing at a size of this parameter is confirmed with results of wire grids internal structure analysis. On the basis of obtained data the choice technique like grid has been developed for production of a filtering partition with optimum characteristics at the set size of filtering nominal subtlety. On the basis of porous body channel model the assessment of hydraulic resistance coefficient value of wire grids with various type of wires interlacing has been carried out. Dependence of this parameter on wires interlacing type has been established. Groundlessness of interstice’s tortuosity coefficient use at assessment of grids hydraulic resistance has been shown.

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Hu, Yong, Xin Shen, Ye Hu, Maosen Wang, Qichao Zhang, Qing Zou, and Bin Li. "A winding machine for polarized wire grid of microwave radiometer calibration." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 233, no. 5 (August 16, 2018): 1916–25. http://dx.doi.org/10.1177/0954410018791888.

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Polarized wire grid has been used as a low-energy polarization separator in many calibration systems. A novel machine was developed for winding the polarized wire grids with different sizes and shapes. In this paper, the process of design including parameters calculation, structural analysis, and the calibration for the winding device is presented. Finally, taking an oval grid as an example, the fabrication and the testing results is shown. A 250 mm×350 mm oval polarized wire grid is fabricated by using this machine, with 0.1 mm diameter molybdenum wires at the distance of 0.3 ± 0.02 mm. And it achieved the 01. mm flatness requirement. The machine used is robust and can be easily extended to even 200 × 200 mm2 – 500 mm × 500 mm grids with 0.08–0.2 mm diameter wires at the distance of 0.1–0.5 mm.

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Fu Xiuhua, 付秀华, 林晓敏 Lin Xiaomin, 张功 Zhang Gong, 王野 Wang Ye, and 张静 Zhang Jing. "红外宽波段亚波长金属线栅偏振元件的研制." Chinese Journal of Lasers 48, no. 9 (2021): 0903002. http://dx.doi.org/10.3788/cjl202148.0903002.

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Chitti Babu, Y., Ch Anuradha, and P. Sri Rama Chandra Murty. "An Fuzzy Trust Based Energy Aware Multipath Secure Data Collection in WSN." International Journal of Engineering & Technology 7, no. 3.27 (August 15, 2018): 371. http://dx.doi.org/10.14419/ijet.v7i3.27.17975.

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A Wireless Sensor Network (WSN) is an array of radar nodules that energetically organize itself into a cable-less grid without utilizing any prevailing arrangement. One of the significant issues in WSNs is the drive’s intake, whereby the grid’s lifespan is reliant on this aspect. Security is another significant issues in cable-less radar grids, because of absence of wire/cable besides resource constraint’s nature. Reliance model shows a key role in fortifying the radar grids by recognizing the egotistical, malevolent and give-in nodules and separating them from message grid. Directed Random Propagation (DRP) operates two-hop vicinity data to enhance the circulation competence, leading to a reduced pack capture possibility. In this study, Shuffled Frog Leaping Algorithm (SFLA) is applied to augment ill-defined faith centered drive conscious multiple route locked data group in WSN.

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Liu, Hai Rui, Jun Sheng Yu, and Xiao Ming Liu. "Characteristic of Free Stand Wire-Grid Polarizers in Sub-Millimeter Wave Range." Applied Mechanics and Materials 290 (February 2013): 127–32. http://dx.doi.org/10.4028/www.scientific.net/amm.290.127.

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Free stand wire-grids (FSWG) are widely used as polarizers, beam splitters, attenuators, and interferometers in millimeter wave and THz ranges. FSWG behaves as low-loss element as the wire grid is unsupported with a substrate, and provides good performance in the range of 0.1-3.0 THz. This paper analyzes the characteristic of the wire-grid polarizers in sub millimeter wave range. These analysis include the spectral transmittance with different wire spacing and incident angle. In order to evaluate the analysis, we measured the transmittance of wire-grid polarizer by using a novel quasi-optical system. Test results of transmittance show that the extinction ratio is over 15 dB up to 700GHz, which agrees well with predictions.

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Yamada, Itsunari, Kohei Fukumi, Junji Nishii, and Mitsunori Saito. "Near-Infrared Polarizer with Tungsten Silicide Wire Grids." Japanese Journal of Applied Physics 50, no. 1R (January 1, 2011): 012502. http://dx.doi.org/10.7567/jjap.50.012502.

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Sanabria, J. C., B. L. Berman, C. Cetina, P. L. Cole, W. R. Dodge, V. G. Nedorezov, A. S. Sudov, and G. Ya Kezerashvili. "Parallel-plate avalanche detectors with anode wire grids." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 441, no. 3 (March 2000): 525–34. http://dx.doi.org/10.1016/s0168-9002(99)00857-8.

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Yamada, Itsunari, Kohei Fukumi, Junji Nishii, and Mitsunori Saito. "Near-Infrared Polarizer with Tungsten Silicide Wire Grids." Japanese Journal of Applied Physics 50 (January 20, 2011): 012502. http://dx.doi.org/10.1143/jjap.50.012502.

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Yu, Shengbao, Guanliang Dong, Nannan Liu, Xiyang Liu, Chang Xu, Yanju Ji, and Hui Luan. "Diagnosis for Conductor Breaks of Grounding Grids Based on the Wire Loop Method of the Transient Electromagnetic Method." Mathematical Problems in Engineering 2019 (March 20, 2019): 1–11. http://dx.doi.org/10.1155/2019/1489543.

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The wire loop method of the transient electromagnetic (TEM) method is used to nondestructively detect conductor breaks of grounding grid. For this purpose, grounding grids serve as an underground wire loop, and the measuring points are arranged on the ground. At each measuring point, a receiving loop is employed to detect the electromagnetic response generated by transmitting the current of the transmitting loop. Conductor breaks can be diagnosed by analyzing the slices of the electromagnetic response. We study the effect of loop size and height difference through the simulation of an intact 2×2 grounding grid, confirming that it is easier to obtain the topological structure using a small transmitting loop and a small height difference. Furthermore, simulations of an intact 4×4 grounding grid and grids with different locations of conductor breaks are also conducted with a small transmitting loop. It is easy to distinguish the topological structure of the grounding grid and the locations of conductor breaks. Finally, the detection method is applied experimentally. The experimental results confirm that the proposed method is an effective technique for conductor break diagnosis.

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BHOWMICK, A., W. C. J. CARVALHO, A. V. KORGAONKAR, J. V. YAKHMI, and V. C. SAHNI. "A NEW GRIDLESS ION OPTICS FOR HIGH RESOLUTION TIME-OF-FLIGHT MASS SPECTROMETER." International Journal of Modern Physics B 19, no. 15n17 (July 10, 2005): 2621–26. http://dx.doi.org/10.1142/s0217979205031420.

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Wire meshes commonly used as transmission grids in ion optical configurations has certain unavoidable disadvantages. Apart from the loss in transmission, there are small angle deflections while the ions are passing close to the wires. This is important for high resolution time-of-flight mass spectrometry as this effect impairs both the dynamic range and the resolution. The amount of deflection from various commercially available grids are determined from simulation calculations on representative wire grids. Gridless designs of ion optics are becoming more popular in recent times for sophisticated and sensitive measurements. Here we report such a device for time of flight mass spectrometer that also assists in perpendicular ionization. This ion optics together with a gridless ion reflector gives a high time resolution of more than 40000.

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11

Yatsenko, V. V., S. A. Tretyakov, S. I. Maslovski, and A. A. Sochava. "Higher order impedance boundary conditions for sparse wire grids." IEEE Transactions on Antennas and Propagation 48, no. 5 (May 2000): 720–27. http://dx.doi.org/10.1109/8.855490.

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12

Wood, Timothy A., William D. Lawson, Priyantha W. Jayawickrama, and James G. Surles. "Pullout Behavior of Steel Mechanically Stabilized Earth Reinforcements." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 52 (May 11, 2018): 238–50. http://dx.doi.org/10.1177/0361198118758314.

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Instrumented pullout tests of unprecedented scope and scale explore the pullout behavior for three steel mechanically stabilized earth reinforcement types: ribbed strips, ladder-like strips, and three-wire bar mat grids. These data quantify the distribution of pullout resistance between longitudinal elements and illustrate the nature of certain reinforcement deformations. Consistent with characteristic inextensible pullout behavior and soil-reinforcement interaction, synthesized strain-gage data illustrate linear stress reduction along the embedment length during pullout for all three reinforcement styles. For ladder-like strips, the axial force divides evenly between the two longitudinal elements. For the three-wire bar mat grid, the center bar carries approximately 40% of the axial force, whereas each outside bar carries approximately 30% of the axial force. Observed pullout-induced deformation in the transverse elements of three-wire bar mat grids having widely spaced longitudinal bars is conceptually different from extensible behavior and suggests the need for refinement in current pullout resistance formulations.

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Zhurakhivskyi, A. V., Z. M. Bakhor, A. Ya Yatseiko, and V. H. Hapanovych. "Formation of a Strategy for Increasing the Efficiency of Operation of Distribution Electrical Grids at the Stage of Pre-Design Works." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 62, no. 2 (April 4, 2019): 155–67. http://dx.doi.org/10.21122/1029-7448-2019-62-2-155-167.

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The main criterions to assess the quality of operation of distribution electrical grids are considered. It is shown that in power supply companies as early as at the pre-design formation of the strategy of modernization and reconstruction of electrical grids, it is necessary to choose the optimal measures for each mainline with a clear sequence of implementation of the selected measures in the electrical grid taking into account prospects of its development. A mathematical model of the classification of mainlines of distribution electrical grids has been developed according to the state of their operation, viz. successful operation, strenuous operation and unacceptable operation. On the basis of this model an algorithm for a choice of the optimal technical measures for the reconstruction of mainlines has been formed depending on their state: for mainlines in the strenuous state it is possible to replace the wire of the section or an installation of a battery of statistical capacitors at the remote transformer substations; for mainlines in the unacceptable state, in accordance with the results of an expert assessment of possible measures taking into account the electrical grid development, the prospects of increase of the load, the construction of unloading points, the connection to the distributed generation electrical grid, a decision is being made to replace the wire section, to transform a part or the whole electrical grid to higher voltage level. This allows formalizing the procedure for the choice and implementation the outlined measures as early as at the stage of pre-design formation of the modernization and reconstruction strategy so to provide an efficient use of funds for the reconstruction and technical retooling of distribution electrical grids in order to improve the quality of their operation. The mathematical model and the algorithm for the choice of the optimal technical measure for the reconstruction of the mainline taking into account the prospects for development that had been developed was tested during the development of the optimal strategy for the development of 6–10 kV distribution electrical grids in the Western region of Ukraine.

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Ekinci, Yasin, Harun H. Solak, Christian David, and Hans Sigg. "Bilayer Al wire-grids as broadband and high-performance polarizers." Optics Express 14, no. 6 (2006): 2323. http://dx.doi.org/10.1364/oe.14.002323.

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Mishra, Vivek, and Sachin S. Sapatnekar. "Probabilistic Wire Resistance Degradation Due to Electromigration in Power Grids." IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems 36, no. 4 (April 2017): 628–40. http://dx.doi.org/10.1109/tcad.2016.2584054.

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Спиридонов, В., V. Spiridonov, О. Кирикова, O. Kirikova, А. Ельчанинов, and A. El'chaninov. "Filter Characteristics of Porous Wire Gauze Partitions." Safety in Technosphere 7, no. 4 (June 24, 2019): 43–48. http://dx.doi.org/10.12737/article_5cf66af7ab5389.61512953.

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The article presents the results of experimental studies of the uneven distribution of the distances between the wires of the warp and weft in woven wire meshes with square cells used to clean gases and liquids from mechanical impurities in various branches of technology. On the basis of experimental data using the methods of probability theory, the regularity of the size distribution of the cells of these grids is determined. The length of its minimum side is chosen as the determining size of a square cell. The results of the conducted studies were used to estimate the fractional coefficient of the leakage of spherical particles through the mesh in the sieve mechanism of separation of these particles from the fluid flow. The probability of particle breakthrough through the grid is assumed to be equal to the fraction of the fluid flow passing through the cells, which determines the size of which is larger than the particle diameter. For experimental verification of the calculated values of the leakage coefficient for the sieve filtering mechanism, a preliminary analysis of the influence of the parameters of the hydrodynamic mode of fluid flow through the grid and the level of fluid contamination on the filtering mechanism was carried out. The results of experimental studies of the fractional leakage coefficient values obtained by the sieve filtering mechanism are compared with the calculated data.

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ERTUNÇ, Ö., N. ÖZYILMAZ, H. LIENHART, F. DURST, and K. BERONOV. "Homogeneity of turbulence generated by static-grid structures." Journal of Fluid Mechanics 654 (May 11, 2010): 473–500. http://dx.doi.org/10.1017/s0022112010000479.

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Homogeneity of turbulence generated by static grids is investigated with the help of hot-wire measurements in a wind-tunnel and direct numerical simulations based on the Lattice Bolztmann method. It is shown experimentally that Reynolds stresses and their anisotropy do not become homogeneous downstream of the grid, independent of the mesh Reynolds number for a grid porosity of 64%, which is higher than the lowest porosities suggested in the literature to realize homogeneous turbulence downstream of the grid. In order to validate the experimental observations and elucidate possible reasons for the inhomogeneity, direct numerical simulations have been performed over a wide range of grid porosity at a constant mesh Reynolds number. It is found from the simulations that the turbulence wake behind the symmetric grids is only homogeneous in its mean velocity but is inhomogeneous when turbulence quantities are considered, whereas the mean velocity field becomes inhomogeneous in the wake of a slightly non-uniform grid. The simulations are further analysed by evaluating the terms in the transport equation of the kinetic energy of turbulence to provide an explanation for the persistence of the inhomogeneity of Reynolds stresses far downstream of the grid. It is shown that the early homogenization of the mean velocity field hinders the homogenization of the turbulence field.

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Gomes-Fernandes, R., B. Ganapathisubramani, and J. C. Vassilicos. "Particle image velocimetry study of fractal-generated turbulence." Journal of Fluid Mechanics 711 (September 12, 2012): 306–36. http://dx.doi.org/10.1017/jfm.2012.394.

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AbstractAn experimental investigation involving space-filling fractal square grids is presented. The flow is documented using particle image velocimetry (PIV) in a water tunnel as opposed to previous experiments which mostly used hot-wire anemometry in wind tunnels. The experimental facility has non-negligible incoming free-stream turbulence (with 2.8 % and 4.4 % in the streamwise (${u}^{\ensuremath{\prime} } / U$) and spanwise (${v}^{\ensuremath{\prime} } / U$) directions, respectively) which presents a challenge in terms of comparison with previous wind tunnel results. An attempt to characterize the effects of the incoming free stream turbulence on the grid-generated turbulent flow is made and an improved wake-interaction length scale is proposed which enables the comparison of the present results with previous ones for both fractal square and regular grids. This length scale also proves to be a good estimator of the turbulence intensity peak location. Furthermore, a new turbulence intensity normalization capable of collapsing${u}^{\ensuremath{\prime} } / U$for various grids in various facilities is proposed. Comparison with previous experiments indicates good agreement in turbulence intensities, Taylor microscale, as well as various other quantities, if the improved wake-interaction length scale is used. Global and local isotropy of fractal-generated turbulence is assessed using the velocity gradients of the two-component (2C) two-dimensional (2D) PIV and compared with regular grid results. Finally, the PIV data appear to confirm the new dissipation behaviour previously observed in hot-wire measurements.

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Sergan, Tatiana, Marina Lavrentovich, Jack Kelly, Eric Gardner, and Douglas Hansen. "Measurement and modeling of optical performance of wire grids and liquid-crystal displays utilizing grid polarizers." Journal of the Optical Society of America A 19, no. 9 (September 1, 2002): 1872. http://dx.doi.org/10.1364/josaa.19.001872.

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Monteiro, Vitor, Julio S. Martins, João Carlos Aparício Fernandes, and Joao L. Afonso. "Review of a Disruptive Vision of Future Power Grids: A New Path Based on Hybrid AC/DC Grids and Solid-State Transformers." Sustainability 13, no. 16 (August 22, 2021): 9423. http://dx.doi.org/10.3390/su13169423.

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Power grids are evolving with the aim to guarantee sustainability and higher levels of power quality for universal access to electricity. More specifically, over the last two decades, power grids have been targeted for significant changes, including migration from centralized to decentralized paradigms as a corollary of intensive integration of novel electrical technologies and the availability of derived equipment. This paper addresses a review of a disruptive vision of future power grids, mainly focusing on the use of hybrid AC/DC grids and solid-state transformers technologies. Regarding hybrid AC/DC grids in particular, they are analyzed in detail in the context of unipolar and bipolar DC grids (i.e., two-wire or three-wire DC grids), as well as the different structures concerning coupled and decoupled AC configurations with low-frequency or high-frequency isolation. The contextualization of the possible configurations of solid-state transformers and the different configurations of hybrid transformers (in the perspective of offering benefits for increasing power quality in terms of currents or voltages) is also analyzed within the perspective of the smart transformers. Additionally, the paper also presents unified multi-port systems used to interface various technologies with hybrid AC/DC grids, which are also foreseen to play an important role in future power grids (e.g., the unified interface of renewable energy sources and energy storage systems), including an analysis concerning unified multi-port systems for AC or DC grids. Throughout the paper, these topics are presented and discussed in the context of future power grids. An exhaustive description of these technologies is made, covering the most relevant and recent structures and features that can be developed, as well as the challenges for the future power grids. Several scenarios are presented, encompassing the mentioned technologies, and unveiling a progressive evolution that culminates in the cooperative scope of such technologies for a disruptive vision of future power grids.

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Sangregorio, Miguel, Ningfei Wang, Kan Xie, Zun Zhang, and Xiaojun Wang. "Rapid fabrication of ion optics by selective laser melting." Rapid Prototyping Journal 25, no. 2 (March 4, 2019): 299–307. http://dx.doi.org/10.1108/rpj-05-2017-0085.

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Purpose Traditional ion optics manufacturing processes are complex and costly. The purpose of this paper is to study the feasibility of using selective laser melting (SLM) to produce additively manufactured ion optics. Design/methodology/approach An SLM machine was used to generate Ti6Al4V screen grids. The output was separated through wire cutting from the build platform and studied through a scanning electron microscope. To increase the geometrical accuracy of the original grid, samples consisting of nine-aperture arrays were fabricated with different parameter combinations, increasing the energy density. An empirical method to correlate the energy density applied in the fabrication process with the dimensional accuracy of the hole array positioning was developed through the analysis of multiple samples. Findings The SLM machine generated grids with optimal microstructure, the apertures fell within the specified tolerances and tolerances of slightly less than 10 µm can be guaranteed for the hole array positioning. The grids’ upper surfaces presented good-quality surface finish, and the lower surface quality was acceptable when the wire cutting process that separated the grid from the build platform performed slowly. Regardless of the build strategy, the stresses generated in the separation process caused the warping of the ion optic, so a flattening operation was necessary in all cases. Originality/value This research proved that SLM is a viable solution for ion optics fabrication, faster (less than 24 h) and less expensive (order of US$300) than traditional fabrication methods (with fabrication times from 24 to more than 400 h and costs from US$500 to US$5,000, depending on the material, size and shape).

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Landrac, Gabrielle, René Clequin, and Philippe Gelin. "Characterization of wire-grids for filters in circular waveguides at millimetre wavelengths." International Journal of Numerical Modelling: Electronic Networks, Devices and Fields 2, no. 1 (March 1989): 1–15. http://dx.doi.org/10.1002/jnm.1660020102.

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Taniguchi, Y., Y. Baba, N. Nagaoka, and A. Ametani. "Modification on a Thin-Wire Representation for FDTD Calculations in Nonsquare Grids." IEEE Transactions on Electromagnetic Compatibility 50, no. 2 (May 2008): 427–31. http://dx.doi.org/10.1109/temc.2008.921034.

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Nicolai, Massimo, Mauro Zanuccoli, Paolo Magnone, Marco Galiazzo, Diego Tonini, Matteo Bertazzo, Enrico Sangiorgi, and Claudio Fiegna. "Simulation Study of Multi-wire front Contact Grids for Silicon Solar Cells." Energy Procedia 77 (August 2015): 129–38. http://dx.doi.org/10.1016/j.egypro.2015.07.020.

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Łukasz, Kwaśny, and Dariusz Zieliński. "Control of a Four-wire Hybrid Prosumer Converter for Balancing Utility Grids." Power Electronics and Drives 6, no. 1 (January 1, 2021): 1–11. http://dx.doi.org/10.2478/pead-2021-0001.

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Abstract The paper presents the project of the power electronic AC/DC converter operating under a multiresonant control algorithm for prosumer applications. This design allows independent control of active and reactive power for any or each phase. Both the converter and its algorithm are based on a three-phase converter of four-wire topology (AC/DC 3p-4w) with a DC bus, which couple the converter to a renewable energy source and energy storage. Further, model and simulation tests were carried out in the Matlab-SIMULINK programming environment. The results obtained indicate that operation with deep unbalances and powers of opposite signs in individual phases results in current variations (oscillations) in the DC line, which is a significant limitation, and it can be concluded that the level of asymmetry should be limited to the level acceptable to the energy storage device.

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Ivanov, Dmitry, Marat Sadykov, Aleksandr Golenishchev-Kutuzov, Danil Yaroslavsky, Tatyana Galieva, and Amir Arslanov. "The application of the technology of sensor networks for the intellectualization of the overhead power transmission lines." E3S Web of Conferences 220 (2020): 01071. http://dx.doi.org/10.1051/e3sconf/202022001071.

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The length of overhead power transmission lines in the Russian Federation is over 2.8 million kilometers. Power grids are rapidly becoming obsolete. The level of deterioration of the equipment achieves 70% [1]. This leads to breakdowns on overhead power transmission lines and reduce the quality of electricity supply. One of the focus areas towards improving the situation is a deep modernization of the power grid with an orientation on energy efficiency. The purpose of this work is the creation a system for operative monitoring of the technical condition of high-voltage power-transmission lines based on modular devices. The modular device is configured depending on the issues at hand: control of ice formation; control of ice melting; localization of the place of short circuit, breakage, lightning strike; determination of electrical loads on the wire or control of the load of overhead power transmission lines; determination of mechanical loads at the wire suspension point; determination of conditions for the occurrence of ice formation, determination of defects in insulators. This will equip the overhead line diagnostic systems without serious financial costs by simple installation on the wire of the developed device which design allows to change the configuration of the equipment and solve a wide range of tasks.

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Utting, W. S., and N. Jones. "Axial–Torsional interactions and wire deformation in 19-wire spiral strand." Journal of Strain Analysis for Engineering Design 23, no. 2 (April 1, 1988): 79–86. http://dx.doi.org/10.1243/03093247v232079.

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Tensile tests were performed on a straight steel strand of three layer (12/6/1) construction, having a core wire diameter of 3.66 mm and 3.33 mm diameter helical wires, under conditions of full end-fixity, partial restraint, and ends free from torsional restraint. The torque generated under tensile load was recorded as well as the strand extension and rotation over a 600 mm gauge length. Wire tensions and bending moments in the outer layer of helical wires were determined at the mid-strand position from the outputs of strain gauges in groups of three with parallel grids and mounted parallel to the wire axis on the crown of each wire. The rate of strand extension under tensile load was found to be greater in tests with reduced torsional restraint, the greatest rate occurring in the free-end test. The strand rotation rate was also found to be greatest in the free-end test. The greatest difference from the theoretically predicted rates occurred in a free-end test with increasing load; predicted values of extension and rotation underestimated the test results by 12 and 23 per cent, respectively. Displacement of the load-torque plots occurred in the direction of reducing torque as testing proceeded. This appears to indicate the redistribution of the strand load between the layers of wires. Wire tensions showed a more even sharing of load in the fixed-end condition than in the free-end condition. The increase in rate of tension with strand load was less for most wires in tests with reduced torsional restraint, with the lowest tension rates developing in the free-end condition. For most wires, the rate of bending moment change with strand load was greater (in the sense tending to decrease tensile stress on wire crowns) in tests with reduced torsional restraint. However, the bending moment rates varied greatly between wires, the variation being greater in tests with reduced torsional restraint than in fixed-end tests.

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Burgos-Mellado, Claudio, Alessandro Costabeber, Mark Sumner, Roberto Cárdenas-Dobson, and Doris Sáez. "Small-Signal Modelling and Stability Assessment of Phase-Locked Loops in Weak Grids." Energies 12, no. 7 (March 30, 2019): 1227. http://dx.doi.org/10.3390/en12071227.

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This paper proposes a low-complexity small signal model for a 3-leg converter connected to a balanced three-phase, three-wire weak grid and synchronised to this grid using a PLL implemented in a synchronous rotating d-q axis. A thorough analysis of the system stability as a function of the PLL bandwidth and the short circuit ratio (SCR) of the grid is performed based on a linearised model. By using the proposed model, an improved design process is proposed for the commonly used dq-PLL that accounts for the potential stability issues which may occur in weak grids. Using the proposed approach, it is possible to optimise the PLL design to find the fastest PLL that can operate stably considering the SCR of the grid. In addition, the proposed model is very simple, resulting in a straightforward design tool that could also be used for online stability monitoring. The method is validated through simulations and experimental results from a 5kW laboratory system.

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BAYER KESKİN, Sena Esen, and Ahmet Arif ERGİN. "Continuity of currents across neighboring cells in PMM analysis of thin-wire grids." TURKISH JOURNAL OF ELECTRICAL ENGINEERING & COMPUTER SCIENCES 22 (2014): 582–87. http://dx.doi.org/10.3906/elk-1209-17.

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Lin, Mei, and Yanzhong Yu. "A Design of High-Power Beam Combiner at Millimeter Wavelengths Utilizing Wire Grids." Journal of Infrared, Millimeter, and Terahertz Waves 30, no. 5 (February 5, 2009): 538–43. http://dx.doi.org/10.1007/s10762-009-9468-8.

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Held, Lukas, Felicitas Mueller, Sina Steinle, Mohammed Barakat, Michael R. Suriyah, and Thomas Leibfried. "An Optimal Power Flow Algorithm for the Simulation of Energy Storage Systems in Unbalanced Three-Phase Distribution Grids." Energies 14, no. 6 (March 15, 2021): 1623. http://dx.doi.org/10.3390/en14061623.

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An optimal power flow algorithm for unbalanced three-phase distribution grids is presented in this paper as a new tool for grid planning on low voltage level. As additional equipment like electric vehicles, heat pumps or solar power systems can sometimes cause unbalanced power flows, existing algorithms have to be adapted. In comparison to algorithms considering balanced power flows, the presented algorithm uses a complete model of a three-phase four-wire low voltage grid. Additionally, a constraint for the voltage unbalance in the grid is introduced. The algorithm can be used to optimize the operation of energy storage systems in unbalanced systems. The used grid model, constraints, objective function and solver are explained in detail. A validation of the algorithm using a commercial tool is done. Additionally, three exemplary optimizations are performed to show possible applications for this tool.

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Blanco, A., S. Fonti, A. Piacente, and V. De Cosmo. "Wide band measurement of power transmission coefficients and polarizing efficiency of free standing wire grids in the far infrared." Infrared Physics 27, no. 5 (September 1987): 275–79. http://dx.doi.org/10.1016/0020-0891(87)90067-4.

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Zhu, Qifan, Yuegang Fu, Zhiying Liu, and Mingyu Li. "Integrated structure of polarization detection in the visible spectrum based on double wire grids." Journal of Nanophotonics 12, no. 03 (August 30, 2018): 1. http://dx.doi.org/10.1117/1.jnp.12.036010.

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Heras, Fernando Las, and J. L. Fernández Jambrina. "Efficient modelling of curved surfaces by planar patches and wire grids for electromagnetic scattering." International Journal of Numerical Modelling: Electronic Networks, Devices and Fields 8, no. 6 (November 1995): 417–29. http://dx.doi.org/10.1002/jnm.1660080604.

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Ambekar, Anand S., Sujit Navnath Zadake, and Suresh K. Kangane. "Mini Implant Punch (MIP)." Journal of Indian Orthodontic Society 55, no. 2 (January 22, 2021): 211–14. http://dx.doi.org/10.1177/0301574220965308.

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Implant placement has always been a difficult task to accomplish. Several designs and methods have been proposed for precise implant placement in order to gain absolute anchorage in orthodontics. Implant placement grids and templates have always been used for placing mini implants since 1980. The aim of this article is to provide a simple and efficient method to construct an orthodontic Mini Implant Punch (MIP) made up of Australian 0.018″ stainless steel wire with easy wire bending.

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Vishnoi, Shuchi. "Power Quality Improvement using UPQC with Single and Three-Phase Non-linear Loads in Countryside Areas." International Journal of Soft Computing and Engineering 9, no. 4 (November 5, 2019): 18–24. http://dx.doi.org/10.35940/ijsce.c3281.119419.

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This paper is intended to simulate a power quality conditioning device, Unified Power Quality Conditioner (UPQC), in countryside areas for non-linear loading. From past decades there is much increase in the requirement of the good quality electrical power in single phase distribution grids established in these locations. Due to technical advancement, three-phase loads are practiced more than single phase loads so that the demand for three phase distribution grids is growing. But the installation process of three-phase grids, at countryside areas, is not an economic option and to get access to these systems is a very challenging task. So a neighbouring three-phase distribution system is required to be established at the location, where single-phase to three-phase UPQC with single wire earth return is appropriate for the end user due to economic considerations. A dual compensation strategy is implemented to obtain the reference quantities for controlling the converters. The proposed idea is accomplished to eliminate voltage harmonics and mitigate further instabilities and power quality problems. This system allows the balanced and regulated voltage with lower harmonic content. Synchronous Reference Frame (SRF) based controllers are considered to organize the input grid current and the load voltages of the UPQC. The present prototype under consideration analyses and validates the compensation and controlling techniques using PI controller. The control strategies are simulated using MATLAB/SIMULINK.

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Nishi, S., N. Hashimoto, T. Todaka, and A. Nomura. "A Microguide Wire with a Scale (Scaler Guide)." Interventional Neuroradiology 3, no. 2_suppl (November 1997): 212–14. http://dx.doi.org/10.1177/15910199970030s246.

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There are various methods for measuring an affected vascular size during embolization or percutaneous transluminal angioplasty (PTA). Metallic balls, electrodes, grids, coins on the skin were simple and useful in this sense, but not stable and exact for measuring. A 0.014 “or 0.016” microguide wire with 5 gold markers in the tip is newly developed and used clinically (a scaler guide). One marker measures 1 mm in length. There is a distance of 4 mm between two neighboring markers. A microcatheter is navigated using a standard microguide wire into the vessels of the lesion. Bilateral digital subtraction angiography (DSA) is performed after exchange of a microguide wire with a scaler guide. Magnification ratio between distance measured by DSA and real distance from markers is calculated. Thereafter, the size of the vessels will be measured. With this method, the size of vessels was measured in patients with aneurysm or arteriovenous malformation or stenotic lesion. Selection of coils or PTA balloons could be made easily and effectively. Interventions were more safely performed with this new scaler guide.

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Manabe, T., and A. Murk. "Transmission and reflection characteristics of slightly irregular wire-grids with finite conductivity for arbitrary angles of incidence and grid rotation." IEEE Transactions on Antennas and Propagation 53, no. 1 (January 2005): 250–59. http://dx.doi.org/10.1109/tap.2004.838786.

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LAVOIE, P., L. DJENIDI, and R. A. ANTONIA. "Effects of initial conditions in decaying turbulence generated by passive grids." Journal of Fluid Mechanics 585 (August 7, 2007): 395–420. http://dx.doi.org/10.1017/s0022112007006763.

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The effects of initial conditions on grid turbulence are investigated for low to moderate Reynolds numbers. Four grid geometries are used to yield variations in initial conditions and a secondary contraction is introduced to improve the isotropy of the turbulence. The hot-wire measurements, believed to be the most detailed to date for this flow, indicate that initial conditions have a persistent impact on the large-scale organization of the flow over the length of the tunnel. The power-law coefficients, determined via an improved method, also depend on the initial conditions. For example, the power-law exponent m is affected by the various levels of large-scale organization and anisotropy generated by the different grids and the shape of the energy spectrum at low wavenumbers. However, the results show that these effects are primarily related to deviations between the turbulence produced in the wind tunnel and true decaying homogenous isotropic turbulence (HIT). Indeed, when isotropy is improved and the intensity of the large-scale periodicity, which is primarily associated with round-rod grids, is decreased, the importance of initial conditions on both the character of the turbulence and m is diminished. However, even in the case where the turbulence is nearly perfectly isotropic, m is not equal to −1, nor does it show an asymptotic trend in x towards this value, as suggested by recent analysis. Furthermore, the evolution of the second- and third-order velocity structure functions satisfies equilibrium similarity only approximately.

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Lawson, William D., Priyantha W. Jayawickrama, Timothy A. Wood, and James G. Surles. "Pullout Resistance Factors for Inextensible Mechanically Stabilized Earth Reinforcements in Sandy Backfill." Transportation Research Record: Journal of the Transportation Research Board 2363, no. 1 (January 2013): 21–29. http://dx.doi.org/10.3141/2363-03.

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This paper presents results from a laboratory program of 402 pullout tests of inextensible reinforcements used for walls of mechanically stabilized earth (MSE). Results focus on the evaluation of pullout resistance factors for ribbed-steel strip and welded-steel grid reinforcements embedded in sandy backfill that marginally met AASHTO requirements for select granular fill. This project used Texas Tech University's large-scale MSE test box with dimensions of 12 3 12 3 4 ft and an applied overburden capacity of 40 ft of backfill. This test box facilitated pullout testing at a scale not unlike typical field construction. The research design evaluated pullout resistance factors for both ribbed-strip and welded-grid reinforcements for a variety of independent variables, including overburden pressure, reinforcement length, level of compaction, grid wire size, and grid geometry, such as transverse and longitudinal wire spacing. Appropriate statistical analyses were used to interpret the data within the context of published AASHTO design guidance for inextensible MSE reinforcements. The results show that pullout behaviors of both ribbed strips and welded grids in properly compacted sandy backfill are conservative compared with the default pullout resistance factors provided by AASHTO. The data also suggest that the current AASHTO equations for pullout resistance factors for grid reinforcement do not accurately capture the influence of transverse and longitudinal bar spacings.

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Paschen, Mathias, Hans Joachim Winkel, and Henning Knuths. "Fluid-Structure Interactions in Pelagic Trawls and Probable Consequences for the Selectivity of the Fishing Gear." Advances in Science and Technology 58 (September 2008): 247–56. http://dx.doi.org/10.4028/www.scientific.net/ast.58.247.

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To study the phenomenon of fluid-net-structure interaction of a trawl the authors investigated effects of hydro-elasticity of stiff net panels (grids) by means of special experiments in a wind tunnel. The analyses were especially focused on how the grids affect the current. One of the targets was to observe the correlation between the actual distribution of velocity distant and close to the grid and the respective hydrodynamic load distribution namely under consideration of prevailing geometrical and kinematical parameters. Another aim of the tests was to get an idea of the fluid-dynamic interactions between neighbouring mesh bars which is implicitly expressed in the well known nomographic diagram by Koritzky (1973). And last but not least the third target was to analyse the impact of the grid on the fluid parameters in correlation with further investigations regarding the understanding of the phenomenon of selectivity of fishing gears. In context of these objectives the hydrodynamic loads as well as the current distributions close to and far from the grid surface were measured by a six-component balance, by hot-wire anemometers as well as by a 2d-PIV-system. The tests were focused on small angles of attack. To control the motion of fluid two end plates and a base plate were used. The consequences of a fluid blockage at the end of a grid were analysed. Results are presented and discussed.

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He, Wei, and Aichao Yang. "A Shear-Mode Piezoelectric Heterostructure for Electric Current Sensing in Electric Power Grids." Micromachines 10, no. 6 (June 23, 2019): 421. http://dx.doi.org/10.3390/mi10060421.

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This paper presents a shear-mode piezoelectric current sensing device for two-wire power cords in electric power grids. The piezoelectric heterostructure consists of a cymbal structure and a permalloy plate. The cymbal structure is constructed from a permanent magnet, a brass cap, and shear-mode piezoelectric materials. The permalloy plate concentrates the magnetic field generated by the two-wire power cord on the magnet. Under the force amplification effect of the cymbal structure, the response of the device is improved. A prototype has been fabricated to conduct the experiments. The experimental average sensitivity of the device is 12.74 mV/A in the current range of 1–10 A with a separating distance of d = 0 mm, and the resolution reaches 0.04 A. The accuracy is calculated to be ±0.0177 mV at 1.5 A according to the experimental voltage distribution. The current-to-voltage results demonstrate that the proposed heterostructure can also be used as a magnetoelectric device without bias.

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Florkowski, Marek, Jakub Furgał, and Maciej Kuniewski. "Lightning Impulse Overvoltage Propagation in HVDC Meshed Grid." Energies 14, no. 11 (May 24, 2021): 3047. http://dx.doi.org/10.3390/en14113047.

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This paper reports on the propagation of lightning overvoltage in a high-voltage direct current (HVDC) meshed grid. Since several topologies of meshed grids have been elaborated in the last decade, we used a common comprehensive reference test platform. The lightning impulse propagation was investigated with regard to the impact of surge arresters and the polarity of the lightning stroke concerning the DC line polarity (±500 kV). Various scenarios were considered, including a direct lightning strike to the DC+ conductor, to the tower, and to the shielding wire in the middle of the span, including backflash on the insulators. The influence of tower footing impedance on overvoltage levels at various nodes was assessed, depicting the critical value. A description of the models used in the simulations was provided. The main focus of the paper was on the wide-area propagation of the overvoltages in the meshed grid, at distant terminals and inside the feeders. An interesting observation was the effects of lightning at the far end of the analyzed grid, propagating through multiterminal and long-distance connections. The presented analysis, based on an exemplary meshed HVDC grid, underlines the importance of the insulation coordination studies and system security studies with respect to the localization of overvoltage protection systems.

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Baumann, Hanns U. "Performance of prefabricated high strength welded wire grids in ductile concrete shear wall boundary elements." Structural Design of Tall Buildings 2, no. 1 (March 1993): 33–52. http://dx.doi.org/10.1002/tal.4320020104.

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Devisilov, Vladimir, Yu Novikov, and Vadim Bolshakov. "Combined Porous Mesh Metals and Products Made fromThem." Safety in Technosphere 9, no. 2 (March 16, 2021): 43–48. http://dx.doi.org/10.12737/1998-071x-2021-9-2-43-48.

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In this paper are considered the essence and design-technological features of products made from new types of porous mesh metals (PMM) based on combination of various permeable and impermeable metallic materials interconnected by hot rolling in the vacuum. To create new materials, a combination of different types of metal grids is used. Therefore, these materials have received the name - combined porous mesh metals (CPMM). The technological problem is to create reliable products with predictable strength, filtration and structural characteristics. The technology of manufacturing products from CPMM is complex and includes a large number of technological operations divided into operations for material manufacture and operations for manufacturing from this material a finished product of required application. Material production includes several operations for preparing the initial metal grids (washing, degreasing, marking-out, grid packaging), and complex technological operations for material manufacturing, consisting in joint the grids and embedded materials between themselves (vacuuming, heating to a predetermined temperature, grid package rolling in vacuum and in hot condition, etc.). Each of technological operations for material manufacturing should be carried out in rigid mode ranges, such as temperature mode, package drafting degree mode, etc. A slight deviation from the mode leads to rejected material or significant deviation from the specified parameters. A difficult problem is the interconnection of metallic grids of various types (distinguishing by thickness, wire diameter, etc.), as well as interconnection of solid metallic embedded elements necessary for products formation from the obtained material. As a result of numerous experiments, it has been able to achieve success and develop the technology for CPMM material manufacturing. The developed material and products made from it have been imbedded at the enterprises of those industries, where highly reliable and efficient constructions, made from permeable materials and having specified functional parameters, are required. A new phase separator filter (PSF) for the fuel tank (FT) of a space item has been created and implemented. Currently, sets including 20 typical sizes of PSF of various modifications are delivered. Using of capillary intakes (CIs) with PSF made from CPMM provides reduction of residual rests of fuel liquid components in fuel tanks. CIs with PSF are almost 2 times lighter than CIs, carried out according to traditional frame-grid design.

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Raab, Georgy I., E. I. Fakhretdinova, and R. Z. Valiev. "The Study of the Strained State of the Long-Length Aluminum Billet Obtained by a New Method - Multi-ECAP-Conform." Materials Science Forum 870 (September 2016): 603–7. http://dx.doi.org/10.4028/www.scientific.net/msf.870.603.

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This paper presents the results of a computer and experimental study of a promising severe plastic deformation (SPD) technique, called Multi-ECAP-Conform (M-ECAP-C), for the fabrication of long-length nanostructured billets (wire rods) with an enhanced strength and electrical conductivity from the aluminum alloy EN-AW 6101 per one processing cycle. On the basis of the obtained results, a new rational geometry of the pressing channel for the M-ECAP-C process has been developed. The strained state of pilot samples of wire rods have been studied. Using the method of dividing grids shows the character of accumulation and the achieved level of deformation shear during the experimental treatment, and the average value of the shear deformation of the central region of the workpiece is 3.015. It was found that the error between the obtained values of the experimental method of grids, computer modeling and calculation is, respectively, 10 % and 17 %. The error between the experimental and computer modeling is not so important, so application of the computer modeling to estimate the strain state of the method of the Multi-ECAP-Conform is completely adequate.

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Li, Yongxia, and Yulei Gong. "Design of Three Phase Load Unbalance Automatic Regulating System for Low Voltage Power Distribution Grids." MATEC Web of Conferences 173 (2018): 02040. http://dx.doi.org/10.1051/matecconf/201817302040.

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In the three-phase four wire system of the low voltage side for the distribution grid, the phenomenon of asymmetrical and uneven single phase load were very common, causing unbalance in certain network. When unbalance exists, the system will have a larger line loss and the unbalanced loads can result in efficiency reduction of power energy and voltage quality decline. And then the safety and stabilization of power system in the low-voltage distribution grid will be directly affected. Therefore, based on the problems above, combined with the characteristic of the low voltage distribution grid in the three-phase four wire system, a three phase load unbalance automatic regulating system for low voltage distribution grid is designed. The system is composed of intelligent phase change controller and phase commutation switch. Based on the relevant theoretical analysis and experimental research applied in the system, the results show that this system can reasonably reduce load imbalance, improve power system performance, economic and social benefits.

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Kusuma, Benny, Tavio, and Priyo Suprobo. "Behavior of Concentrically Loaded Welded Wire Fabric Reinforced Concrete Columns with Varying Reinforcement Grids and Ratios." International Journal of ICT-aided Architecture and Civil Engineering 2, no. 1 (June 30, 2015): 1–14. http://dx.doi.org/10.21742/ijiace.2015.2.1.01.

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Sajjad Seyedalipour, S., and Gevork B. Gharehpetian. "Interconnection of Distributed Generation Resources to Three-Phase Four-Wire Grids Using a Novel Control Technique." Indian Journal of Science and Technology 11, no. 30 (August 1, 2018): 1–12. http://dx.doi.org/10.17485/ijst/2018/v11i30/94593.

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50

Spiridonov, V. S., and S. V. Belov. "Properties of porous metals based on wire grids with square cells. II. Hydraulic and filtering characteristics." Soviet Powder Metallurgy and Metal Ceramics 24, no. 12 (December 1985): 941–44. http://dx.doi.org/10.1007/bf00805253.

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Journal articles on the topic 'Wire grids'

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