Impact Properties of Metal-Ceramic Alloys Based on Tungsten-Nickel-Iron-Cobalt System at High-Speed Interaction

2014 ◽  
Vol 1013 ◽  
pp. 176-181
Author(s):  
Svetlana Afanas'eva ◽  
Nikolai Belov ◽  
Yurii Biryukov ◽  
Vladimir Burkin ◽  
Aleksandr Ishchenko ◽  
...  
Keyword(s):  
High Speed ◽  
High Energy ◽  
Porous Composite ◽  
Ceramic Filler ◽  
Iron Cobalt ◽  
Nickel Iron ◽  
Experimental Part ◽  
Metal Ceramic ◽  
Laboratory Technology ◽  
The Given

In the given work, the investigations have been directed to the creation of porous composite materials with MgO and B4C ceramic filler. The laboratory technology of obtaining rods from the given materials has been developed. The experimental part of this work was carried out on ballistic set-ups with shaft-reactive and electrochemical technologies of throwing with the use of high-energy plastisol fuels with nanosize metallic fillers. Mathematical modeling of the behavior of materials under conditions of high-speed interaction was carried out in the framework of a porous elastoplastic medium according to different destruction mechanisms.

scholarly journals Особенности разрушения ударников из пористого сплава на основе вольфрама с упрочняющим наполнителем при взаимодействии с бронепреградами

2020 ◽  
Vol 90 (3) ◽  
pp. 434
Author(s):  
А.Н. Ищенко ◽  
С.А. Афанасьева ◽  
Н.Н. Белов ◽  
В.В. Буркин ◽  
С.В. Галсанов ◽  
...  
Keyword(s):  
High Speed ◽  
Complex Structure ◽  
Experimental Studies ◽  
Effective Area ◽  
Depth Of Penetration ◽  
Iron Cobalt ◽  
Nickel Iron ◽  
High Speed Collision ◽  
Localization Of Plastic Deformation ◽  
Crater Morphology

In this work, computational and experimental studies of the process of destruction of composite firing pin of porous alloy tungsten+nickel+iron+cobalt with 10 % content of titanium tungsten carbide at high-speed collision with steel barriers. It is shown that at ballistic tests with the broad range of speeds, significant exceeding of penetration of these firing pins in steel barriers in comparison with a mass-dimensional analog of the W-Ni-Fe-90 alloy. Based on the analysis of the crater morphology and structure of the striker fragments after penetration into the barrier, the assumption of implementation of the self-sharpenings mode of the firing pin, by means of localization of plastic deformation is made that leads to decrease in the effective area of interaction and increase in depth of penetration. Modification of a mathematical model of a porous ideal elasto-plastic solid with complex structure for the description of destruction with a possibility of accounting of the adiabatic shift mechanism in the course of interaction of the firing pin and a barrier is carried out.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

scholarly journals 1.5 °C degrowth scenarios suggest the need for new mitigation pathways

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lorenz T. Keyßer ◽  
Manfred Lenzen
Keyword(s):  
Technological Change ◽  
High Speed ◽  
Large Scale ◽  
High Energy ◽  
Climate Mitigation ◽  
Intergovernmental Panel ◽  
Economic Output ◽  
Integrated Assessment Modelling ◽  
Negative Emissions ◽  
Energy Emissions

Abstract1.5  °C scenarios reported by the Intergovernmental Panel on Climate Change (IPCC) rely on combinations of controversial negative emissions and unprecedented technological change, while assuming continued growth in gross domestic product (GDP). Thus far, the integrated assessment modelling community and the IPCC have neglected to consider degrowth scenarios, where economic output declines due to stringent climate mitigation. Hence, their potential to avoid reliance on negative emissions and speculative rates of technological change remains unexplored. As a first step to address this gap, this paper compares 1.5  °C degrowth scenarios with IPCC archetype scenarios, using a simplified quantitative representation of the fuel-energy-emissions nexus. Here we find that the degrowth scenarios minimize many key risks for feasibility and sustainability compared to technology-driven pathways, such as the reliance on high energy-GDP decoupling, large-scale carbon dioxide removal and large-scale and high-speed renewable energy transformation. However, substantial challenges remain regarding political feasibility. Nevertheless, degrowth pathways should be thoroughly considered.

Detector commissioning and development for PETRA-III

2010 ◽  
Vol 1 (SRMS-7) ◽  
Author(s):  
David Pennicard ◽  
Heinz Graafsma ◽  
Michael Lohmann
Keyword(s):  
High Speed ◽  
Materials Science ◽  
Dynamic Range ◽  
Photon Counting ◽  
High Energy ◽  
X Rays ◽  
Silicon Detectors ◽  
Time Resolved ◽  
Wide Range ◽  
Synchrotron Light

The new synchrotron light source PETRA-III produced its first beam last year. The extremely high brilliance of PETRA-III and the large energy range of many of its beamlines make it useful for a wide range of experiments, particularly in materials science. The detectors at PETRA-III will need to meet several requirements, such as operation across a wide dynamic range, high-speed readout and good quantum efficiency even at high photon energies. PETRA-III beamlines with lower photon energies will typically be equipped with photon-counting silicon detectors for two-dimensional detection and silicon drift detectors for spectroscopy and higher-energy beamlines will use scintillators coupled to cameras or photomultiplier tubes. Longer-term developments include ‘high-Z’ semiconductors for detecting high-energy X-rays, photon-counting readout chips with smaller pixels and higher frame rates and pixellated avalanche photodiodes for time-resolved experiments.

scholarly journals NONLINEAR DYNAMICS OF SOFT FERMION EXCITATIONS IN HOT QCD PLASMA: SOFT-QUARK BREMSSTRAHLUNG AND ENERGY LOSSES

2010 ◽  
Vol 25 (04) ◽  
pp. 685-776 ◽  
Author(s):  
YU. A. MARKOV ◽  
M. A. MARKOVA ◽  
A. N. VALL
Keyword(s):  
Semiclassical Approximation ◽  
Gluon Plasma ◽  
High Energy ◽  
Energy Losses ◽  
Dynamical Equations ◽  
Model Case ◽  
Radiative Processes ◽  
Higher Order Terms ◽  
The Given ◽  
Approximate Expressions

Within the framework of a semiclassical approximation the general theory of calculation of effective currents and sources generating bremsstrahlung of an arbitrary number of soft quarks and soft gluons at collision of a high-energy color-charged particle with thermal partons in a hot quark–gluon plasma is developed. For the case of one- and two-scattering thermal partons with radiation of one or two soft excitations, the effective currents and sources are calculated in an explicit form. In the model case of "frozen" medium, approximate expressions for energy losses induced by the most simple processes of bremsstrahlung of soft quark and soft gluon are derived. On the basis of a conception of the mutual cancellation of singularities in the sum of so-called "diagonal" and "off-diagonal" contributions to the energy losses, an effective method of determining color factors in scattering probabilities containing the initial values of Grassmann color charges is suggested. The dynamical equations for Grassmann color charges of hard particle used by us earlier on are proved to be insufficient for investigation of the higher radiative processes. It is shown that for correct description of these processes the given equations should be supplemented successively with the higher-order terms in powers of the soft fermionic field.

SIMULATION SCHEME MODELING OF THE SUPER-SPEED TIME BUFFER

2020 ◽  
Author(s):  
А.М. САЖНЕВ ◽  
Л.Г. РОГУЛИНА
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Low Cost ◽  
Circuit Modeling ◽  
Clock Signal ◽  
Behavioral Models ◽  
Software Environment ◽  
Time Buffer ◽  
The Given ◽  
Simulation Scheme

Приводятся результаты моделирования сверхскоростного буфера тактовых сигналов, выполненного на базе арсенид-галлиевых n-канальных транзисторов в среде OrCAD и полностью отвечающего следующим требованиям: высокие технические характеристики, малые размеры, высокая частота и КПД, гибкость применения. Приведенные поведенческие модели допускают использование любой программной среды по схемотехническому моделированию. The results of simulation of an ultra-high-speed clock signal buffer based on gallium arsenide n-channel transistors in OrCAD are presented, which fully meets the following requirements: high technical characteristics, application flexibility, low cost, small size, high frequency, and high efficiency. The given behavioral models allow the use of any software environment for circuit modeling.

High Speed Imaging of Forced Ignition Kernels in Non-Uniform Jet Fuel/Air Mixtures

2017 ◽  
Author(s):  
Sheng Wei ◽  
Brandon Sforzo ◽  
Jerry Seitzman
Keyword(s):  
Heat Release ◽  
High Speed ◽  
Air Flow ◽  
Cetane Number ◽  
High Energy ◽  
Liquid Fuels ◽  
High Speed Imaging ◽  
Ignition Probability ◽  
Turbine Engine ◽  
Planar Laser

This paper describes experimental measurements of forced ignition of prevaporized liquid fuels in a well-controlled facility that incorporates non-uniform flow conditions similar to those of gas turbine engine combustors. The goal here is to elucidate the processes by which the initially unfueled kernel evolves into a self-sustained flame. Three fuels are examined: a conventional Jet-A and two synthesized fuels that are used to explore fuel composition effects. A commercial, high-energy recessed cavity discharge igniter located at the test section wall ejects kernels at 15 Hz into a preheated, striated crossflow. Next to the igniter wall is an unfueled air flow; above this is a premixed, prevaporized, fuel-air flow, with a matched velocity and an equivalence ratio near 0.75. The fuels are prevaporized in order to isolate chemical effects. Differences in early ignition kernel development are explored using three, synchronized, high-speed imaging diagnostics: schlieren, emission/chemiluminescence, and OH planar laser-induced fluorescence (PLIF). The schlieren images reveal rapid entrainment of crossflow fluid into the kernel. The PLIF and emission images suggest chemical reactions between the hot kernel and the entrained fuel-air mixture start within tens of microseconds after the kernel begins entraining fuel, with some heat release possibly occurring. Initially, dilution cooling of the kernel appears to outweigh whatever heat release occurs; so whether the kernel leads to successful ignition or not, the reaction rate and the spatial extent of the reacting region decrease significantly with time. During a successful ignition event, small regions of the reacting kernel survive this dilution and are able to transition into a self-sustained flame after ∼1–2 ms. The low aromatic/low cetane number fuel, which also has the lowest ignition probability, takes much longer for the reaction zone to grow after the initial decay. The high aromatic, more easily ignited fuel, shows the largest reaction region at early times.

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