Analysis of existing radioparent refractory materials, composites and technology for creating high-speed rocket radomes. Part 2. Comparative analysis of the main properties of materials used for creating rocket radomes

2010 ◽  
Vol 51 (4) ◽  
pp. 283-288 ◽  
Author(s):  
E. I. Suzdal’tsev ◽  
D. V. Kharitonov ◽  
A. A. Anashkina
2020 ◽  
Vol 2020 (10) ◽  
pp. 8-21
Author(s):  
A. G. Kolmakov ◽  
◽  
I. O. Bannykh ◽  
V. I. Antipov ◽  
L. V. Vinogradov ◽  
...  

he basic ideas about the process of introducing cores into protective barriers and the most common core patterns and their location in conventional and sub-caliber small arms bullets are discussed. The materials used for manufacture of cores are analyzed. It is concluded that for mass bullets of increased armor penetration the most rational choice can be considered the use of high-carbon low-alloy steels of a new generation with a natural composite structure and hardness of up to 70 HRC. For specialized armor-piercing bullets, cores made from promising economically-alloyed high-speed steels characterized by a high complex of «hardness—bending strength» are better alternative than ones made of hard alloys or tungsten alloys.


Author(s):  
Cédric Lopez ◽  
François Malburet ◽  
André Barraco

This paper studies problematic of a mechanical system composed of different coupled parts submitted to a high speed shock and proposes analysis of anti vibratory passive and active methods based on an experimental and theoretical coupled approach. After a shock, different parts of the system oscillate. If one of them is excited at a particular frequency, such as its proper frequency, important oscillations appear and can lead to the deterioration of the system by introducing important stresses. In this paper, we propose an analysis in order to understand this kind of problem and what we can do to avoid it. Firstly, we discuss problematic and we expose the studied system. In a second time, we develop two approaches of modeling that allow us to understand the phenomenon by carrying out numerical simulations. Then cross checking of model is completed via experimental study on drop test bench. Passive minimization method of vibrations based on experimental and theoretical coupled approach is exposed. Finally, a comparative analysis of different methods of control and experimental results of controlled system are presented.


2013 ◽  
Vol 307 ◽  
pp. 368-371
Author(s):  
Yu Ling Liu ◽  
Juan Wang ◽  
Bao Hong Gao

In this paper, the multi-hydroxyl polyamines researched by ourselves are used in the slurry of the copper wiring CMP of GLSI, which makes the slurry alkalization. It also has the using as a pH adjusting agent, complexion agent of copper ion, multi- metal chelating agents, aminating agent of acidic oxides, pH buffer, stainless steel corrosion inhibitor, the active agent and pro-oxidant. It improves the property of slurry and solves many different of acidity slurry. The alkalinity slurry contained the multi-hydroxyl polyamines is environmental, inexpensive and composition- simplified. Without the toxic BTA which is must be used in the international and has side effect, the slurry can achieve the high speed and high flat. In the same time the low pressure and the little abrasive can be realized, which provide the new material for the removal of TSV copper film.


Author(s):  
Ali Mardani ◽  
Sultan Husein Bayqra ◽  
Süleyman Özen ◽  
Zia Ahmad Faqiri ◽  
Kambiz Ramyar

2021 ◽  
pp. 38-43
Author(s):  
A. V. Genis ◽  
A. V. Kuznetsov ◽  
Yu. P. Nekrasov

A comparative analysis of the efficiency of the most common types of adsorbents of various natures in a test environment with high humidity for obtaining filled fibrous sorption-active materials by the method of solution aerodynamic spinning is carried out. The influence of the spinning methods, the composition and structure of the obtained sorption-active filled fibrous materials, the nature of the polymer matrix, and the type of organic test substances on the protective properties of materials has been studied.


Akustika ◽  
2019 ◽  
Vol 32 ◽  
pp. 30-35
Author(s):  
Valery Murzinov ◽  
Pavel Murzinov ◽  
Irina Ivanovna

This article provides an overview of modern soundproof materials and structures used for acoustic insulation. Presently, we can find plenty of such noise insulation and sound absorption materials. One of the popular means to reduce noise and control sound today is the acoustic panels able to suppress and absorb different sounds. The article also analyses the effectiveness of acoustic and sound protection materials used in the industrial sphere. The comparative analysis of the sound protection and absorption effectiveness is carried out using sound absorption coefficients. It also presents the construction of a sound suppressing lightweight structured panel designed by the authors. The authors noted that these panels have better characteristics in comparison with other modern sound protection materials.


Author(s):  
SABITA NAHATA ◽  
SUBRATA BHATTACHARYA

Inter-symbol interference (ISI) due to multipath fading is a vital problem in high-speed wireless communication which restricts communication quality and capacity. Therefore, in addition to choosing a fading mitigation technique, it is also important to strategically select a modulation scheme for effective data transmission. Recent literature review on wireless standards, such as 3G and 4G indicates that QAM and QPSK are suitable choices for data transmission. In this paper, a comparative analysis on selected modulation schemes is performed in a fading environment. The mitigation of fading is done using adaptive equalization technique. Also, we show that the signal to noise ratio (SNR) is an important parameter to choose. It is observed that, even when an adaptive equalizer is used at the receiver, a very low SNR gives very high symbol error rate (SER). We derive some important conclusions from our simulation result: QPSK shows minimum SER, whereas 256-PSK and 256-PAM perform worse. Given its spectral efficiency and a low SER, the best choice is 256- QAM.


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