Shield Plate Research Articles

Знахідки І тис. н. е. у Полтавському Поворсклі: за матеріалами робіт 2016 р.

The article deals with the finds of the second and third quarters of 1st millennium CE, which were found and transferred by local residents from the villages Velyka Rublivka, Drany, Ustimenki and Opishnia. The finds are fibulae, mirrors, a detail of the chest lock and fragments of pottery. The upper shield plate of the Eastern European emaciated enamel fibula (fig. 1, 1; 2, 1) — re-folded / a crossbar, type II according to G.F. Korzukhina, or T-shaped type with triangular or cruciform legs, the developed phase, seria 2, type II, according to E.L. Gorokhovskyi, in the vicinity of Velyka Rublivka village was discovered. The three-fingered fibula from the village Drany (fig. 1, 2; 2, 2) refer to the transitional type from the lamellar to the palatine types. The fragments of two mirrors (fig. 1, 4, 5; 2, 4, 5) from Ustimenky belong to the Sarmatian time and find the wide analogies among the Sarmatian burials of the Northern Black Sea Coast and the Crimea. Also, the detail of the chest lock or the clamp of the provincial-Roman type (fig. 1, 3; 2, 3), although there are similar finds on the Cherniakhiv culture sites. The Penkivka culture settlement near the Rag doll museum in Opishnia was also discovered.

An Inductive and Capacitive Combined Parallel Transmission of Power and Data for Wireless Power Transfer Systems

A new parallel transmission method of power and data is proposed for peer-to-peer wireless power transfer (WPT) systems. Essentially, data are modulated and transferred via high-frequency electric field generated by the parasitic capacitances of the coupling coils and the metal shield plates, while power is transferred through relatively low-frequency magnetic field generated by the coupling coils. Coupling structure and operation principle are illustrated and analyzed. Besides, the signal to noisy ratio performance is studied and optimized. With the proposed method, a 40 W prototype is built and the data transmission rate reaches 230 kbps. Experimental results have verified that the proposed method is valid and has the advantages of good flexibility and large spatial position offset redundancy. Because the method does not do any modification on the main circuit of the WPT system, it also has advantages of low cost and easy to implement.

Development of a solar tracking system of a nonelectric power source by using a metal hydride actuator

This study develop the solar tracking system of a nonelectric power source by using a metal hydride (MH) actuator with solar radiation drive. The proposed tracking system includes two MH reactors of the same shape that are placed perpendicular to the solar cell array. A shielding plate is installed between the MH reactors to interrupt the solar radiation from each MH reactor. The solar angle of direction changes when there is a temperature difference between the MH reactors. This is because a gap occurs in the equilibrium pressure of the hydrogen sealed hermetically in each reactor, and the actuator angle of direction follows the sun according to this pressure difference. This study also present the result of the proposed system after four months of testing. Moreover, this study examine the wind’s influence on the proposed MH actuator by applying heat fluid simulation. In order to achieve highly reliable solar tracking with the proposed system, excessive cooling by wind should be prevented by installing a windshield.

Influence of shielding plates on dynamical response of HL-2M vacuum vessel due to electromagnetic force during a plasma disruption

PurposeIn this paper, numerical modelling and dynamical response analysis were performed for the HL-2M vacuum vessel (VV) and shielding plates (SPs) during a plasma disruption by using an updated ANSYS parametric design language (APDL) code developed by the authors. The purpose of this paper is to investigate the influence of the SPs on the dynamical response of VV owing to a transient electromagnetic (EM) force and to optimize the design of SPs in view of the minimization of the structural dynamic response.Design/methodology/approachThe Lagrangian approach, i.e. the moving coordinate scheme developed by the authors, was updated to tackle the EM-mechanical coupling effect in the dynamic response analysis of the VV-SPs system due to the transient EM force during plasma disruptions. To optimize the structural design of HL-2M SPs, the influence of the key parameters of SPs, i.e., the side length, thickness and material properties, was clarified on the basis of the numerical results and an optimized design of SPs was obtained.FindingsThe updated APDL code of the Lagrangian approach is efficient for the transient dynamical response analysis of the VV-SPs system owing to the EM force. The SP of a smaller side length, larger thickness tungsten material better mitigates the dynamical response of the VV-SPs system.Originality/valueThe Lagrangian approach was updated for the EM–mechanical coupling dynamical response analysis of the VV-SPs system, and the influence of the SP parameters on the dynamical response of the VV-SPs system of HL-2M Tokamak was clarified.

Multilayer magnetic shielding: an innovative overlapping structure

The study deals with magnetic shields for distribution systems mainly devoted to medium voltage/low voltage sub-station. In the category of passive system, a new multilayer shielding plate is presented. The main purpose of the proposed solution is the reduction of the gap between the ferromagnetic sheets by a proper overlapping in order to reduce the local leakage fluxes. Plates characterised by different conductive and ferromagnetic thicknesses have been realised and tested. The effect of the welding of the conductive part is finally analysed.

Null-Coupled Electromagnetic Field Canceling Coil for Wireless Power Transfer System

In this paper, we present a kind of null-coupled canceling (NCC) coil to shield electromagnetic fields (EMFs) for wireless power transfer (WPT) systems. The proposed NCC coil is based on the particular zero-mutual-inductance characteristic between two general coils. The working principles, shielding effectiveness, and practical expansions of the proposed NCC coil are illustrated. Furthermore, locating of the zero-mutual-inductance position and determination of the canceling coil current are elaborated, and effects that an NCC coil exerts on the output power, efficiency, and misalignment tolerance of the applied WPT system are theoretically studied. Finally, targeted at our predesigned electric vehicle wireless charging-oriented WPT prototype, a practical NCC coil is built and tested with comparative experiments with the prevalent aluminum (Al) plate shielding. The experimental results show that, with a properly chosen canceling current, the proposed NCC coil could not only shield the EMF more effectively, but also cause a lower efficiency reduction to the applied WPT system than an Al-plate does.

Thermohydraulic analysis of hydroformed radiation shield plate

Hydroformed panels are widely used in fusion reactor components as a thermal radiation shield, for cryopumps and cryostats. In a cryopump, the pumping surface area is cooled down below 5K and is shielded from direct outer thermal radiation by using radiation shield panel cooled at 80K. Therefore, high cryogenic operational mass flows are required and thus pressure drop and heat transfer characteristics are important aspects of study. CFD analysis for radiation shield plate (2045 mm × 1800 mm × 3 mm) has been carried out when gaseous helium at 15 bar and 80K was inserted under heat flux of 365 W/m2. Further analyses were made for variable mass flow rate (i.e. 20 g/sec to 50 g/sec) to obtain optimum value of pressure drop with accurate thermal distribution on hydroformed shield plate.

RELATIONS OF HEAT RADIATION EFFECT AND SHIELDING EFFECT BY OPENING OF THE MAGNETIC SHIELD PLATE

Extremely low frequency (ELF) magnetic fields from electric power lines and electric appliances cause errors in the even correct operation of medical and laboratory equipments. High-permeability material plates surrounding all four sides of cables can achieve the best shielding performance. However, the shielding structure reduces the cooling capability and degrades the current carrying capacity of the cable. In a previous report, the authors examined the performance of a magnetic shield using perforated high-permeability alloy plates. In this paper, the authors carried out "the inspection of the heat radiation effect with the opening" and “the relative inspection of the heat radiation effect and the magnetic shielding effect". This experimental model was consisted of three electric cables connected to a three-phase AC power supply, and a magnetic shield surrounding the cables. To evaluate the heat radiation effect, the authors measured the temperature of the cable surface, in three-phase AC current 400 A. Each cable was horizontally placed 50 mm away from each other. The magnetic shield was made from 0.5 mm thick, perforated Permalloy PB plates and was formed a square tube with 150 mm x 150 mm x 1000 mm in size. Six types of Permalloy PB plates were tested. The opening ratio was 0% (no ventilating hole), 10%, 20%, 30%, 40% and 50%, respectively. The holes were 5 mm in diameter and arranged in straight centers pattern. Next, numerical thermo-fluid 3-D analysis was performed using FVM software, STREAM (Software Cradle Co., Ltd. Japan). The rise in temperature of the cable surface was calculated by models same as the experiment, and the authors defined the calculating formula to evaluate a heat radiation effect with the opening. In addition, by the experiment circuit and opening conditions same as the above, the authors measured the magnetic flux density. In this paper, the authors compare the performance of magnetic shielding using the shielding factor, which is the ratio of the measured magnetic flux density to that in non-shielding condition. To evaluate the magnetic shielding effect at the time of the opening, the authors defined the calculating formula of the hold ratio on the basis of a magnetic shielding effect when there was no ventilating hole. Main results are follows. A: From the inspection of the heat radiation effect by the experiments and the numerical analyses, it was shown that the rise in temperature of the cable surface decreased when the opening area of the shield plate was increasing. B: The authors defined the expression of the heat radiation effect, and inspected the difference by the opening rate. In the experiments and analyses, similar characteristics were provided. C: In the inspection of the magnetic shielding effect by the experiments, it was shown that the magnetic shielding effect decreased when the opening area of the shield plate was increasing. D: In "the heat radiation effect by the opening ratio" and "the hold ratio of the magnetic shielding effect by the opening ratio ", the authors showed the relations of both clearly.

A superconducting manifold‐coupled triplexer with an iterative design method at X‐band

ABSTRACTThis paper presents a superconducting manifold‐coupled narrowband triplexer at X‐band frequency. The high Q‐value resonator is adopted to create a filter with low insertion loss. Impedance matching and iterative design methods are used to design the duplexer and manifold structure. Furthermore, metal shielding plates are used to separate the three channels to suppress the box resonant modes. The three bandwidths of the superconducting triplexer are all 60 MHz, and the center frequencies are 9.0, 9.12, and 9.24 GHz. The triplexer exhibits good performance at 65 K, with an insertion loss of 0.7 dB at 9.24 GHz. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2949–2954, 2016

Improvement in luminance efficiency of organic light emitting diodes by suppression of secondary electron bombardment of substrate during sputter deposition of top electrode films

In this study, we investigated the degradation mechanisms of the luminance performance of organic light-emitting diodes (OLEDs) when their top electrode films were deposited by sputter deposition process. During the sputter deposition of the top electrode films, the suppression of the incidence of high-energy electrons on the substrate was attempted using various methods. As a result, we found that during electrode deposition, the incidence of the high-energy secondary electrons, which were emitted from the target surface, on the substrate was the main cause of the significant degradation of the luminance performance. It was also found that the application of a magnetic field by setting permanent magnets near the substrate holder and the insertion of a shield plate near the target cathode were effective in suppressing the incidence of secondary electrons on the substrate.

Ultrastructural analysis of siliceous cell wall regeneration in the stramenopile Triparma laevis (Parmales, Bolidophyceae)

:The marine alga Triparma laevis NIES-2565, belonging to the Parmales (Bolidophyceae), possesses a siliceous cell wall that is composed of shield, ventral, dorsal and girdle plates. The cell wall is lost under silicate-deficient culture conditions. Regeneration of the cell wall occurs with the addition of sufficient silicate ions into the culture medium. In this study, the formation of the siliceous cell wall was observed by transmission electron microscopy. Silica deposition vesicles (SDVs) forming the shield and ventral plates were initially found around the chloroplast, moving toward the plasma membrane as they expanded, with siliceous plates being built within the SDV. The SDV membrane was tightly adpressed to the siliceous plate. In contrast, SDVs for dorsal and girdle plates were formed adjacent to the plasma membrane. Extracellular secretion of mature siliceous plates began with shield plates, followed in turn by ventral, dorsal and girdle plates. The dorsal and girdle plates were inserted into the space between the previously secreted shield and ventral plates. Our study demonstrates that SDVs develop in different areas of the cell, according to whether they are forming dorsal and girdle plates or shield and ventral plates.

Nonlinear Probabilistic Analysis of the Failure Pressure of NPP Shielding Plate

This paper describes the nonlinear probabilistic analysis of the failure pressure of the shielding plate of the reactor box of the nuclear power plant under a high internal overpressure and temperature. The scenario of the hard accident in Nuclear power plant (NPP) and the methodology of the calculation of the fragility curve of the failure overpressure using the probabilistic safety assessment PSA 2 level is presented. The fragility curve of the failure pressure was determined using 45 probabilistic simulations using the response surface method (RSM) with the Central Composite Design (CCD) for 106 Monte Carlo simulations for each model and 5 level of the overpressure.

Electromagnetic Field Analysis of a Dipole Coil Element With Surface Impedance Characterized Shielding Plate for 7-T MRI

In this paper, we systematically investigate the electromagnetic (EM) field of a stripline dipole coil element backed by various shielding plates, which are characterized by surface impedance. The initial analysis is based on a 2-D finite-element-method model, where the considered surface impedance was categorized in terms of magnitude and phase. It has been demonstrated that the shielding plate can be approximately modeled by the magnitude of a complex surface impedance if the absolute EM field distribution is considered. Additionally, as the magnitude of the surface impedance increases, the magnetic and electric fields excited by the stripline tend to distribute in a broader manner. Thus, the transversal homogeneity of the $B_{1}$ field of a stripline coil can be improved by a shielding plate with a high surface impedance, which has been verified by 3-D models based on single- and multi-coil elements. For the experimental validation, two shielding plates—a copper-plated substrate and a high-impedance surface, which exhibits a small and large surface impedance, respectively—are considered. An excellent agreement of field distributions between numerical simulation and measurement has been observed.

In situ baking method for degassing of a kicker magnet in accelerator beam line

In this study, the authors propose a new in situ degassing method by which only kicker magnets in the accelerator beam line are baked out without raising the temperature of the vacuum chamber to prevent unwanted thermal expansion of the chamber. By simply installing the heater and thermal radiation shield plates between the kicker magnet and the chamber wall, most of the heat flux from the heater directs toward the kicker magnet. The result of the verification test showed that each part of the kicker magnet was heated to above the target temperature with a small rise in the vacuum chamber temperature. A graphite heater was selected in this application to bake-out the kicker magnet in the beam line to ensure reliability and easy maintainability of the heater. The vacuum characteristics of graphite were suitable for heater operation in the beam line. A preliminary heat-up test conducted in the accelerator beam line also showed that each part of the kicker magnet was successfully heated and that thermal expansion of the chamber was negligibly small.

多層断熱技術Ⅱ

The calorimeter is used to test the thermal performance of multilayer insulation (MLI). The data obtained by the calorimeter installed in a laboratory must be utilized to estimate the thermal performance of MLI fabricated in the actual cryostat for superconducting magnets or the storage vessel for low-temperature liquefied gas. If MLI is fabricated in an actual cryostat so as to be in the state of self-compression, the non-dimensional parameter P* of the compression pressure between the adjacent layers plays an important role as an experimental condition. In order to design a calorimeter, it is necessary to pay attention to its apparent thermal conductivity, which is lowest among all insulation materials and has extremely large anisotropy. In view of this, the MLI sample must be fabricated so that it covers the entire surface of the calorimeter test cylinder, and the cross-section of MLI at its ends must not be exposed to hot surfaces or shield plates. Some amount of distortion or small steps on the cold surface where the MLI is wrapped may cause wrinkles in the MLI; at which time it becomes impossible to determine the value of P*. A new calorimeter utilizing a small cryo-cooler and heat-flow meter is shown. This calorimeter is expected to enable to allow experiments to proceed efficiently by eliminating the burden of handling liquefied gases, like liquid helium.

酸化クロム触媒を用いた熱分解によるCFRPの補修技術の開発

This paper presents the preliminary investigation of repairing method for CFRP based on TASC (Thermal Activation of Semi-Conductors) technique by removing the matrix resin and inserting the reinforced thread in the target area of CFRP. In order to optimize the joining process, temperature effects on decomposition rate and fiber damage during the decomposition process was studied. The decomposition rate increased as temperature increased whereas the decomposition rate was constant at the temperature of more than 450 °C. By contrast, carbon fiber damaged at the temperature of more than 460 °C. Hence, the optimal temperature of decomposition process was revealed. Decomposition process have been optimized by developing the heating configuration. Homogenous heating was achieved by using radiator and shielding plates with optimal heat source distance from the heating objective. Finally, it is possible to carry out the strength evaluation test using single-lap test specimen created by the proposed method.

Contextualising bow fibulae with Boeotian shield plates: Cultural transfer processes during early iron age in the Central Balkan area

Despite the fact that double-looped fibulae with catch-plates in the form of a Boeotian shield have been frequently discussed, it is worthwhile examining the type again from a supra-regional perspective. The following paper, therefore, has two aims. First, the typo-chronological development of the fibulae with catch-plates in the form of a Boeotian shield within the Central Balkan area is considered. The second part of the paper focuses on the processes of the spread of the fibula type. The question is raised as to what extent local elites - integrated in supra-regional networks - could have functioned as transmitters and agents in the processes of cultural transfer.

Effect of surface topological structure and chemical modification of flame sprayed aluminum coatings on the colonization of Cylindrotheca closterium on their surfaces

Biofouling is one of the major problems for the coatings used for protecting marine infrastructures during their long-term services. Regulation in surface structure and local chemistry is usually the key for adjusting antifouling performances of the coatings. In this study, flame sprayed multi-layered aluminum coatings with micropatterned surfaces were constructed and the effects of their surface structure and chemistry on the settlement of typical marine diatoms were investigated. Micropatterned topographical morphology of the coatings was constructed by employing steel mesh as a shielding plate during the coating deposition. A silicone elastomer layer for sealing and interconnection was further brush-coated on the micropatterned coatings. Additional surface modification was made using zwitterionic molecules via DOPA linkage. The surface-modified coatings resist effectively colonization of Cylindrotheca closterium. This is explained by the quantitative examination of a simplified conditioning layer that deteriorated adsorption of bovine calf serum proteins on the zwitterionic molecule-treated samples is revealed. The colonization behaviors of the marine diatoms are markedly influenced by the micropatterned topographical morphology. Either the surface micropatterning or the surface modification by zwitterionic molecules enhances antimicrobial ability of the coatings. However, the combined micropatterned structure and zwitterionic modification do not show synergistic effect. The results give insight into anti-corrosion/fouling applications of the modified aluminum coatings in the marine environment.

THE GEOMORPHOLOGICAL INDICATIONS OF HORIZONTAL NEOTECTONIC MOVEMENTS ALONG THE BOUNDARY BETWEEN BALTIC SHIELD AND WEST-ARCTIC PLATFORM (MURMANSK REGION)

Horizontal component of neotectonic movements in platform conditions can be identified by comparing the morphostructural pattern of the region with the known structural models of horizontal deformations. Through the juncture of the Baltic shield and Barents plate, which is the part of the Western Arctic platform the two sutures pass: Karpinsky lineament – latitudinal zone of discontinuities, by which crystalline basement is dipping step by step seaward and thrust-shear structure Trollfjord–Rybachiy–Kanin. Characteristic features for this area are as follows: concentration of cracks, bearing tectonic mirrors and furrows slip, faults and near-fault deformations, manifested by the valleys and canyons, and the steps of relief, the formation of which cannot be explained by selective denudation of the substrate. The epicenters of earthquakes are numerous here. By the geological data the morphostructures were distinguished here with the indications of rotations of blocks, leading to the subsidences in the areas of stretching and shears along an echelon faults and also movements in mutually antithetic directions – right and left strike-slips of unknown age. Antithetic movements along the plate boundaries can be explained by the complex nature of the interaction of the East European platform with its frame.

Detonation initiation in shielded thin layers of explosives by shaped-charge jets

The main features of detonation initiation in shielded thin layers of an explosive impacted by high-velocity metal shaped-charge jets are presented. It has been shown experimentally that the exclusion of the initial shock-wave stage of loading of the explosive by shielding the explosive layer by a compressible light material significantly reduces the initiating ability of the shaped-charge jet. The critical conditions of detonation initiation in thin layers of explosives placed between metal plates impacted by shaped-charge jets normally and at an angle of 30° have been experimentally determined; maximum thicknesses of the shielding plates of different materials have been determined above which detonation in the explosive does not occur even upon exposure to the high-velocity head element of a shaped-charge jet.