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The unfeasible fabrication of helix slow wave structures in W-band traveling wave tubes makes necessary to find alternative slow wave structures in order to amplify the RF signal to the output levels required to overcome atmospheric attenuation in satellite communications. Meander lines are nowadays being studied as slow wave structures for W-band traveling wave tubes due to their favorable properties compared to full metal alternatives. A novel meander line topology is introduced in this work, showing that high gain and output power can be achieved using a low-voltage electron beam. Cold and large signal simulations are presented in this work.
High temperature superconductors --- Millimeter wave devices
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Technical information is provided in this guide related to liquid-immersed power, distribution, and regulating transformers that are designed to operate at temperatures that exceed the normal thermal limits of IEEE Std C57.12.00(TM), under continuous load, in the designed average ambient and at rated conditions. Guidelines for applying high-temperature solid and liquid materials as insulation systems; guidelines for loading high-temperature liquid-immersed power, distribution, and regulating transformers; and guidelines on test procedures for qualifying new high-temperature solid and liquid insulating materials are included.
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Heat resistant alloys --- High temperature metals --- Refractory metals --- Superalloys --- Alloys --- Heat resistant materials --- Corrosion.
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High furnaces are used since centuries in the field of metallurgy. They have been upgraded in term of capacity, efficiency, size, and environmental footprint. Indeed, while processing, iron and steel making produce by products such as sludges, dusts, and slags. Nowadays cold biding technologies start to be studied in the field due to the potential save of energy and the problem of resources depletion. In first time, studies have been made to analyze the global behavior of pure iron pastilles in a simulation of BF process. 2 different binders has been used : FE14 (organic) and cement combined with bentonite (non-organic). As planned, their behaviors were totally different. The mechanical properties of samples containing Alcotac FE14 tended to decrease a lot just after the increase of temperature, in contrary to the recipes with cement and bentonite. However after 700°C, others physicals phenomenon like sintering start to counterbalance the effect of binder. Also, the addition of anthracite (carbon) in some recipes has as effect to decrease the (or at least slow down the increase) the quality of the samples due to the evaporation of mater (Boudouard reaction). In a second time, a large panel of recipes containing a large panel of binders/binder combinations were briefly studied in order to not loose too munch time. The results in term of mechanical properties led some interesting point : -CB11 binder seems to have acceptable mechanicals properties at high temperature (700°C) despite the fact that is an organic material. -Carbon addition seems to have an effect before its degradation with boudouard reaction. -Cement added with other component than bentonite gives bad results. -Using by products tends to decrease a lot the quality of the samples In a last time, deeper studies on recipes from 2nd campaign revealed the fact that, not only the quality (in term of mechanical properties) of the agglomerate change by using secondary resources, but also its behave all along the BF treatment. Thus, making extrapolations of what would happen to samples containing by products (sludges, dusts,…) from data coming from experiments made on pure iron agglomerates seems to not be judicious. This 3rd campaign also revealed better the necessity to control the amount of carbon in the recipe. Indeed, agglomerated containing to munch carbon were not characterizable due to their degradation inside the crucible after 900°C.
sludges --- High temperature furnace --- Agglomerate --- Binders --- Recycling --- Metal --- Iron --- Steel --- Ingénierie, informatique & technologie > Science des matériaux & ingénierie --- Physique, chimie, mathématiques & sciences de la terre > Chimie
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During the last years we have witnessed colossal advancements in all-electrical doping control on cuprates. In the vast majority of cases, the tuning of charge carrier density has been achieved via electric field effect by means of either a ferroelectric polarization or by using a dielectric or electrolyte gating. Unfortunately, these approaches are constrained to rather thin superconducting layers and require large electric fields in order to ensure sizable carrier modulations [1, 2]. In this master thesis, we focus on the investigation of oxygen doping in an extended region through current-stimulated oxygen migration in Y B a 2 Cu 3 O 7−δ superconducting bridges. The underlying methodology is rather simple and avoiding sophisticated overlay nanofabrication process steps and complex electronics. A patterned multiterminal transport bridge configuration allows us to electrically assess the directional counterflow of oxygen atoms and vacancies. Importantly, the emerging propagating front of current-dependent doping δ isprobed in situ by polarized optical microscopy and scanning electron microscopy. The resulting imaging techniques, together with photo-induced conductivity and Raman scattering investigations reveal an inhomogeneous oxygen vacancy distribution with a controllable propagation speed permitting us to estimate the oxygen diffusivity. These findings provide direct evidence that the microscopic mechanism at play in electrical doping in cuprates involves diffusion of oxygen atoms with the applied current. The resulting fine control of the oxygen content in complex oxides paves the way towards a systematic study of complex phase diagrams and the design of electrically addressable devices.
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In this Special Issue of Sensors, seven peer-reviewed manuscripts appear on the topic of ultrasonic transducer design and operation in harsh environments: elevated temperature, high gamma and neutron radiation fields, or the presence of aggressive chemicals. Motivations for these research and development projects are strongly focused on nuclear power plant inspections (particularly liquid-sodium cooled reactors), and nondestructive testing of high-temperature piping installations. It is anticipated that extensive use of permanently mounted robust transducers for in-service monitoring of petrochemical plants and power generations stations; quality control in manufacturing plants; and primary and secondary process monitoring in the fabrication of engineering materials will soon be made.
PMN-PT --- neutron irradiation --- TUCSS --- L-waves --- field-deployable sensor --- structural health monitoring --- ultrasonic --- piezoelectric wafer active sensor --- nondestructive testing --- high-temperature monitoring --- FBR --- gallium phosphate --- NDT (Non Destructive Testing) --- inspection --- guided wave --- elevated temperature --- imaging --- sodium --- pressurized water reactor fuel rods --- high-temperature ultrasonic testing --- ultrasonic transducer --- dry coupling --- reactor --- lithium niobate --- non-destructive evaluation --- guided-wave send–receive --- spray-on transducers --- NDE --- piezoelectric --- harsh environment --- R --- EMAT sensor --- piezocomposites --- ISI& --- SFR --- NDT --- liquid sodium --- thickness shear --- Phased Array --- NDE (Non Destructive Evaluation) --- ultrasound --- high temperature --- radiation --- radiation resistance --- in-service inspection --- nuclear power plants
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Throughout the history of materials science and physics, few topics have captured as much interest as the phenomenon of superconductivity (SPC), discovered in 1911. Perhaps this is because of the intriguing interpretation of the phenomenon, which remains controversial, or for the secret hope of being able to synthesize a material with a critical superconductive transition temperature (TC) high enough to revolutionize the sector of energy generation and transport. As a matter of fact, the search for new superconductor materials has motivated an army of scientists, in particular, after the discovery of high-TC superconductor cuprates (HTS) in the mid-80s. Besides the unremitting interest in HTS, new materials, such as intermetallic borides, iron–nickel-based superconductors, heavy fermion, and organic and superhydride systems, are still delivering outstanding achievements to the scientific community, among which includes thousands of papers and a handful of Nobel prize winners). This Special Issue “Synthesis and Characterization of New Superconductor Materials” is a collection of scientific contributions providing new insights and advances in this fascinating field, addressing issues ranging from the fundamental research (theory and correlation between critical temperature, TC, and structural properties) to the development of innovative solutions for practical applications of superconductivity: Synthesis of new superconducting materials Magnetic and/or electric characterization of the TC transition Role of crystal symmetry and chemical substitutions on TC TC dependence on external stimuli and/or non-ambient conditions Theoretical modeling
Research & information: general --- Dirac electron --- Landau level --- interlayer magnetoresistance --- organic conductor --- α-(BEDT-TTF)2I3 --- Er123 --- melt temperature --- superconducting solder --- superconducting joint --- FeSe --- superconductivity --- high pressure --- chemical intercalation --- interfacial coupling --- AC susceptibility --- BaZrO3 --- co-precipitation --- solid-state --- YBa2Cu3O7−δ --- Weyl semimetal --- focused ion beam --- high-temperature superconductors --- bismuth-based cuprates --- Bi-2212 --- Dirac electron --- Landau level --- interlayer magnetoresistance --- organic conductor --- α-(BEDT-TTF)2I3 --- Er123 --- melt temperature --- superconducting solder --- superconducting joint --- FeSe --- superconductivity --- high pressure --- chemical intercalation --- interfacial coupling --- AC susceptibility --- BaZrO3 --- co-precipitation --- solid-state --- YBa2Cu3O7−δ --- Weyl semimetal --- focused ion beam --- high-temperature superconductors --- bismuth-based cuprates --- Bi-2212
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Throughout the history of materials science and physics, few topics have captured as much interest as the phenomenon of superconductivity (SPC), discovered in 1911. Perhaps this is because of the intriguing interpretation of the phenomenon, which remains controversial, or for the secret hope of being able to synthesize a material with a critical superconductive transition temperature (TC) high enough to revolutionize the sector of energy generation and transport. As a matter of fact, the search for new superconductor materials has motivated an army of scientists, in particular, after the discovery of high-TC superconductor cuprates (HTS) in the mid-80s. Besides the unremitting interest in HTS, new materials, such as intermetallic borides, iron–nickel-based superconductors, heavy fermion, and organic and superhydride systems, are still delivering outstanding achievements to the scientific community, among which includes thousands of papers and a handful of Nobel prize winners). This Special Issue “Synthesis and Characterization of New Superconductor Materials” is a collection of scientific contributions providing new insights and advances in this fascinating field, addressing issues ranging from the fundamental research (theory and correlation between critical temperature, TC, and structural properties) to the development of innovative solutions for practical applications of superconductivity: Synthesis of new superconducting materials Magnetic and/or electric characterization of the TC transition Role of crystal symmetry and chemical substitutions on TC TC dependence on external stimuli and/or non-ambient conditions Theoretical modeling
Dirac electron --- Landau level --- interlayer magnetoresistance --- organic conductor --- α-(BEDT-TTF)2I3 --- Er123 --- melt temperature --- superconducting solder --- superconducting joint --- FeSe --- superconductivity --- high pressure --- chemical intercalation --- interfacial coupling --- AC susceptibility --- BaZrO3 --- co-precipitation --- solid-state --- YBa2Cu3O7−δ --- Weyl semimetal --- focused ion beam --- high-temperature superconductors --- bismuth-based cuprates --- Bi-2212 --- n/a
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The Mediterranean basin is the main area both for the cultivation of durum wheat and for the consumption of derived food products such as pasta, couscous, and bulgur. The ongoing climate changes and new consumer preferences make the selection of genetic materials suitable for the present scenarios particularly difficult. This Special Issue Book covers several aspects of the genetic improvement of durum wheat, collected in seven chapters including two review papers focused on milestones in durum wheat breeding programs across the countries of the Mediterranean basin and sub-Saharan Africa. Water deficit and heat stress occurring during the reproductive stage of wheat have a detrimental effect on yield and grain quality of durum wheat. The papers included in this Special Issue propose selection strategies for traits associated with yield and grain quality (e.g., root architecture, carbon isotope composition of grain, and gluten quality) under natural or artificial environmental conditions of drought, heat, and nutrient stress. This Special Issue presents new breeding opportunities for selecting modern varieties adapted to climate change and expanding durum wheat production.
Research & information: general --- Biology, life sciences --- Agro-industry --- Ethiopia --- oasis wheat --- pasta wheat --- Senegal River --- value chain --- heat stress --- durum wheat --- yield --- tolerance --- fertility --- climate change --- resilience --- aluminum --- resistance --- durum --- hydroponics --- soil acidity --- Triticum turgidum ssp. durum Desf. --- agronomic traits --- carbon isotope --- days to heading --- grain quality --- yield components --- Mediterranean basin --- breeding --- MAS --- biochemical markers --- quality --- proxy traits --- genetic resources --- root screening --- root architecture --- glutenin polymers --- gluten quality --- high temperature --- nitrogen fertilization --- Agro-industry --- Ethiopia --- oasis wheat --- pasta wheat --- Senegal River --- value chain --- heat stress --- durum wheat --- yield --- tolerance --- fertility --- climate change --- resilience --- aluminum --- resistance --- durum --- hydroponics --- soil acidity --- Triticum turgidum ssp. durum Desf. --- agronomic traits --- carbon isotope --- days to heading --- grain quality --- yield components --- Mediterranean basin --- breeding --- MAS --- biochemical markers --- quality --- proxy traits --- genetic resources --- root screening --- root architecture --- glutenin polymers --- gluten quality --- high temperature --- nitrogen fertilization
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This exhaustive work in several volumes and over 2500 pages provides a thorough treatment of ultra-high temperature materials (with melting points around or over 2500 °C). The first volume focuses on carbon (graphene/graphite) and refractory metals (W, Re, Os, Ta, Mo, Nb and Ir), whilst the second and third are dedicated to refractory transition metal 4-5 groups carbides. Topics included are physical (structural, thermal, electro-magnetic, optical, mechanical, nuclear) and chemical (more than 3000 binary, ternary and multi-component systems, including those used for materials design, data on solid-state diffusion, wettability, interaction with various elements and compounds in solid and liquid states, gases and chemicals in aqueous solutions) properties of these materials. It will be of interest to researchers, engineers, postgraduate, graduate and undergraduate students alike. The readers/users are provided with the full qualitative and quantitative assessment, which is based on the latest updates in the field of fundamental physics and chemistry, nanotechnology, materials science, design and engineering.
Materials science. --- Inorganic chemistry. --- Ceramics. --- Glass. --- Composites (Materials). --- Composite materials. --- Characterization and Evaluation of Materials. --- Inorganic Chemistry. --- Ceramics, Glass, Composites, Natural Materials. --- Composites (Materials) --- Multiphase materials --- Reinforced solids --- Solids, Reinforced --- Two phase materials --- Materials --- Amorphous substances --- Ceramics --- Glazing --- Ceramic technology --- Industrial ceramics --- Keramics --- Building materials --- Chemistry, Technical --- Clay --- Inorganic chemistry --- Chemistry --- Inorganic compounds --- Material science --- Physical sciences --- Materials at high temperatures. --- Carbides. --- Heat resistant alloys. --- High temperature metals --- Refractory metals --- Superalloys --- Alloys --- Heat resistant materials --- Carbon compounds --- High temperatures --- Strength of materials
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