scholarly journals Possibility of the Use of Different Types of Materials in Passive Ventilation Systems of Munitions

2016 ◽  
Vol 7 (3) ◽  
pp. 21-34
Author(s):  
Adam WIŚNIEWSKI
Keyword(s):  
Shape Memory ◽  
Thermal Loading ◽  
Slow Heating ◽  
Military Equipment ◽  
Bullet Fragment ◽  
Jet Impact ◽  
Different Types ◽  
Mathematical Equations ◽  
Shape Memory Materials ◽  
Shaped Charge Jet

The paper presents different types of insensitive munition used in military equipment, especially in western countries. Tests of this munition, their parameters, e.g. fast and slow heating, bullet, fragment and shaped charge jet impact and sympathetic reaction are described. The characteristics of shape-memory materials like alloys and polymers are presented. Behaviour of shape-memory alloy is explained by example of TiNi al-loys during mechanical or thermal loading, and martensitic transformation into austen-ite during unloading. Material parameters of the TiNi alloys, their testing and mathematical equations are shown. Venting systems used in the explosive reactive armour cassettes are presented. Different examples of materials, including shape-memory materials in munition, are demonstrated.

scholarly journals Different Types of Ventilation Systems of Munitions

2017 ◽  
Vol 8 (4) ◽  
pp. 23-36
Author(s):  
Adam WIŚNIEWSKI
Keyword(s):  
Temperature Increase ◽  
Shaped Charge ◽  
Slow Heating ◽  
Energy Materials ◽  
After Effects ◽  
Military Equipment ◽  
Different Types ◽  
Sandwich Type ◽  
Shaped Charge Jet ◽  
Ventilation Systems

In the article it is presented the guideline and requirements for construction and technology designing of munition, that allows mitigation and decreasing after effects of stimuli impacting the Insensitive Munition (IM), used in military equipment, i.e. in case of pressure and temperature increase during fire, fast and slow heating, sympathetic detonation, perforation of the munition by a projectile, a fragment or a shaped charge jet. The construction of the IM munition is specified with the use of barriers, ventilation/deaeration of the munition case and double-purpose technology. The features of the active and passive/inert ventilation systems of the IM munition are presented, examples of absorbing energy materials and structure of covers/barriers of a „sandwich” type. Depending on the IM classes of threats and different representative standards and one metric of munition response and technology maturity, there are different consequences of detonation, explosion, deflagration/propulsion, burn, not sustained reaction, etc. observed. Some examples are presented with the use of the shaped-memory alloys or polymers in the Insensitive Munition.

WRINKLING ATOP SHAPE MEMORY MATERIALS

2012 ◽  
Vol 19 (02) ◽  
pp. 1250010 ◽  
Author(s):  
L. SUN ◽  
Y. ZHAO ◽  
W. M. HUANG ◽  
H. PURNAWALI ◽  
Y. Q. FU
Keyword(s):  
Surface Tension ◽  
Surface Roughness ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Patterned Surfaces ◽  
Advantages And Disadvantages ◽  
Different Types ◽  
Shape Memory Materials ◽  
Processing Techniques

Many surface related properties, such as surface roughness, surface tension and reflection etc are heavily dependent on the surface morphology of materials. Patterned surfaces may have significant effects on these properties. In this paper, we compare wrinkles produced atop three different types of shape memory materials, namely, shape memory alloy, shape memory polymer and shape memory hybrid. We show the advantages and disadvantages of them in terms of the processing techniques and the resultant wrinkle patterns.

scholarly journals Blended and more: instructors organize sensemaking opportunities for mathematical equations in different ways when teaching the same scientific phenomenon

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Fang Fang Zhao ◽  
Linh Chau ◽  
Anita Schuchardt
Keyword(s):  
Scientific Understanding ◽  
Biological Phenomenon ◽  
Study Approach ◽  
Different Types ◽  
Multiple Case ◽  
Mathematical Equations ◽  
Scientific Phenomenon ◽  
Student Problem ◽  
Mathematics And Science

Abstract Background Many students solving quantitative problems in science struggle to apply mathematical instruction they have received to novel problems. The few students who succeed often draw on both their mathematical understanding of the equation and their scientific understanding of the phenomenon. Understanding the sensemaking opportunities provided during instruction is necessary to develop strategies for improving student outcomes. However, few studies have examined the types of sensemaking opportunities provided during instruction of mathematical equations in science classrooms and whether they are organized in ways that facilitate integration of mathematical and scientific understanding. This study uses a multiple case study approach to examine the sensemaking opportunities provided by four different instructors when teaching the same biological phenomenon, population growth. Two questions are addressed: (1) What types of sensemaking opportunities are provided by instructors, and (2) How are those sensemaking opportunities organized? The Sci-Math Sensemaking Framework, previously developed by the authors, was used to identify the types of sensemaking. Types and organization of sensemaking opportunities were compared across the four instructors. Results The instructors provided different opportunities for sensemaking of equations, even though they were covering the same scientific phenomenon. Sensemaking opportunities were organized in three ways, blended (previously described in studies of student problem solving as integration of mathematics and science resources), and two novel patterns, coordinated and adjacent. In coordinated sensemaking, two types of sensemaking in the same dimension (either mathematics or science) are explicitly connected. In adjacent sensemaking, two different sensemaking opportunities are provided within the same activity but not explicitly connected. Adjacent sensemaking was observed in three instructors’ lessons, but only two instructors provided opportunities for students to engage in blended sensemaking. Conclusions Instructors provide different types of sensemaking opportunities when teaching the same biological phenomenon, making different resources available to students. The organization of sensemaking also differed with only two instructors providing blended sensemaking opportunities. This result may explain why few students engage in the successful strategy of integrating mathematics and science resources when solving quantitative problems. Documentation of these instructional differences in types and organization of sensemaking provides guidance for future studies investigating the effect of instruction on student sensemaking.

An overview of elastic polymeric shape memory materials for comfort fitting

2017 ◽  
Vol 136 ◽  
pp. 238-248 ◽  
Author(s):  
L. Sun ◽  
W.M. Huang ◽  
T.X. Wang ◽  
H.M. Chen ◽  
C. Renata ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Materials

The small spacecraft with a magnetic sail on high-temperature superconductors

2021 ◽  
pp. 51-61
Author(s):  
Timur Sh. KOMBAEV ◽  
Mikhail K. ARTEMOV ◽  
Valentin K. SYSOEV ◽  
Dmitry S. DEZHIN
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
High Temperature ◽  
Shape Memory ◽  
New Technologies ◽  
High Temperature Superconductors ◽  
Solar Wind Plasma ◽  
Large Area ◽  
Small Spacecraft ◽  
Shape Memory Materials

It is proposed to develop a small spacecraft for an experiment using high-temperature superconductors (HTS) and shape memory materials. The purpose of the experiment is to test a technological capability of creating a strong magnetic field on the small spacecraft using HTS and shape memory materials for deployed large-area structures, and study the magnetic field interaction with the solar wind plasma and the resulting force impact on the small spacecraft. This article is of a polemical character and makes it possible to take a fresh look at the applicability of new technologies in space-system engineering. Key words: high-temperature superconductors, shape memory materials, solar wind, spacecraft.

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