Actual questions of fire safety of materials internal structural elements for special vehicles

Magnesium alloys find their application in aviation technology for manufacturing of structural elements in uninhabited compartments and outside areas with increased fire hazard. At the stage of development of magnesium alloys with low fire hazard, it is advisable to perform comparative tests on relatively small samples so that all test equipment can be located in a laboratory. A method has been developed for conducting flammability tests when exposed to a flame with a temperature of 1,100 ° C for samples of magnesium alloys of small sizes. Comparative tests of two magnesium alloys - the standard ML5 and the new experimental one with increased fire safety - have been carried out. Significant differences have been established in the flammability and extinguishing ability of various grades of magnesium alloys - it is shown that the samples of the experimental magnesium alloy, in comparison with the ML5 alloy, are more difficult to ignite and in most cases can self-extinguish rapidly, while the weight loss of the sample practically does not occur.

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Optimization of foamed plastic technology

E3S Web of Conferences ◽

10.1051/e3sconf/20199706010 ◽

2019 ◽

Vol 97 ◽

pp. 06010

Author(s):

Sergey Kozlov ◽

Boris Efimov ◽

Ekaterina Bobrova ◽

Ekaterina Zinovieva ◽

Ekaterina Zhukova

Keyword(s):

Fire Safety ◽

Experimental Studies ◽

Heat Losses ◽

Structural Safety ◽

Building Structures ◽

Structural Elements ◽

Insulation Systems ◽

Favorable Conditions ◽

Selection Of ◽

Plastic Technology

Insulation systems of building structures involve the solution of the following group of tasks: creation of favorable conditions for the work of structural elements and construction as a whole; optimization of heat losses through the insulation shell; creation of comfortable conditions in the room. Such a system would function normally if effective thermal insulation, including polyethylene, were used. The price of polyethylene foam can be reduced without prejudice to the properties in the case of the use of secondary polyethylene foam. The article presents the results of experimental studies, the purpose of which is to optimize the composition of polyethylene foam with the addition of secondary polyethylene, the formation of methods of selection of its composition and the development of systems for the application of products based on polyethylene foam. The article presents the main provisions of the method of analytical optimization, which allows to significantly reducing the material and time costs of processing the results of the experiment. The article deals with aspects of the implementation of construction systems using products based on polyethylene foam in terms of minimizing heat loss through the contact areas. Mandatory criteria for the construction and implementation of insulation systems are safety conditions, including both structural safety (including maintenance-free cycle) and fire safety.

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Some Approaches to Developing a Test Method for Determining the Actual Fire Resistance Limit of Façade Translucent Structures

E3S Web of Conferences ◽

10.1051/e3sconf/202132002005 ◽

2021 ◽

Vol 320 ◽

pp. 02005

Author(s):

Tatiana Eremina ◽

Dmitry Korol’chenko ◽

Mikhail Vasiliev ◽

Leonid Tanklevskiy ◽

Mikhail Eremin

Keyword(s):

Fire Resistance ◽

Fire Safety ◽

Structural Design ◽

Test Method ◽

Structural Elements ◽

Fire Load ◽

High Rise ◽

Actual Fire ◽

Fire Flame ◽

Fire Impact

Based on the analysis of modern construction of high-rise buildings with façade translucent structures (FTS), it was established that the actual fire resistance limit of FTS for high-rise buildings should be assessed. The criterion for loss of fire resistance of a translucent façade is the collapse or fall-out of fragments of the translucent façade filling that contribute to the spread of fire in the building. By analyzing the experience of tests carried out fragments of buildings with FTS with simulated thermal and/or fire (flame torch) effects, the following factors are taken into account: wind loads with variable directions of air flows; access of fire-fighting and rescue units, etc. During full-scale FTS tests, a possible scenario of fire development is simulated, taking into account the fragment and features of the specimen, the fire load that affects the development of fire along the façade, the structural design of the FTS, – glass (conventional and fireresistant) and structural elements. The authors suggest that in order to ensure fire safety of high-rise buildings with FTS the fire-resistance limit assessment should be carried out on fragments of buildings with a simulation of thermal and/or fire impact, which is close to the real conditions.

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Modern fire safety systems in shopping and entertainment centers

XXI century Technosphere Safety ◽

10.21285/2500-1582-2021-3-303-308 ◽

2021 ◽

Vol 6 (3) ◽

pp. 303-308

Author(s):

Yu. V. Reva ◽

T. N. Gerasimova

Keyword(s):

Fire Safety ◽

Structural Features ◽

Shopping Centers ◽

Structural Elements ◽

Safety Measures ◽

Advantages And Disadvantages ◽

Fire Extinguishing ◽

Safety Systems ◽

Fire Extinguishing System ◽

Specialized System

Currently, the number of shopping centers in Russia is increasing. For their construction, new combustible materials and design solutions are used. This creates a high fire load and requires fire safety measures. To ensure the fire safety of visitors, structural features of buildings are essential; it is also crucial to take into account the psychophysiological characteristics of people in these buildings and their level of familiarity with the main structural elements of the building, willingness to find the fire sign and do their best to leave the building. The article describes promising fire safety systems for shopping centers, their advantages and disadvantages. A specialized system of fire extinguishing means consisting of interconnected software controls and structures and a gas fire extinguishing system and smoke curtains are described.

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Structural phenomena in the growth of carbon nanotubes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100149581 ◽

1993 ◽

Vol 51 ◽

pp. 750-751

Author(s):

Jun Jiao

Keyword(s):

Carbon Nanotubes ◽

Growth Mechanism ◽

Carbonaceous Material ◽

Cluster Growth ◽

Structural Elements ◽

Rich Variety ◽

Different Shapes ◽

Point To Point

HREM studies of the carbonaceous material deposited on the cathode of a Huffman-Krätschmer arc reactor have shown a rich variety of multiple-walled nano-clusters of different shapes and forms. The preparation of the samples, as well as the variety of cluster shapes, including triangular, rhombohedral and pentagonal projections, are described elsewhere.The close registry imposed on the nanotubes, focuses attention on the cluster growth mechanism. The strict parallelism in the graphitic separation of the tube walls is maintained through changes of form and size, often leading to 180° turns, and accommodating neighboring clusters and defects. Iijima et. al. have proposed a growth scheme in terms of pentagonal and heptagonal defects and their combinations in a hexagonal graphitic matrix, the first bending the surface inward, and the second outward. We report here HREM observations that support Iijima’s suggestions, and add some new features that refine the interpretation of the growth mechanism. The structural elements of our observations are briefly summarized in the following four micrographs, taken in a Hitachi H-8100 TEM operating at an accelerating voltage of 200 kV and with a point-to-point resolution of 0.20 nm.

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Designing TIMP (tissue inhibitor of metalloproteinases) variants that are selective metalloproteinase inhibitors

Biochemical Society Symposium ◽

10.1042/bss0700201 ◽

2003 ◽

Vol 70 ◽

pp. 201-212 ◽

Cited By ~ 51

Author(s):

Hideaki Nagase ◽

Keith Brew

Keyword(s):

Three Dimensional ◽

Therapeutic Interventions ◽

Tissue Inhibitors Of Metalloproteinases ◽

Structural Basis ◽

Structural Elements ◽

Ridge Structure ◽

Extracellular Matrix Components ◽

Metalloproteinase Inhibitors ◽

The Matrix ◽

A Disintegrin And Metalloproteinase

The tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of the matrix metalloproteinases (MMPs), enzymes that play central roles in the degradation of extracellular matrix components. The balance between MMPs and TIMPs is important in the maintenance of tissues, and its disruption affects tissue homoeostasis. Four related TIMPs (TIMP-1 to TIMP-4) can each form a complex with MMPs in a 1:1 stoichiometry with high affinity, but their inhibitory activities towards different MMPs are not particularly selective. The three-dimensional structures of TIMP-MMP complexes reveal that TIMPs have an extended ridge structure that slots into the active site of MMPs. Mutation of three separate residues in the ridge, at positions 2, 4 and 68 in the amino acid sequence of the N-terminal inhibitory domain of TIMP-1 (N-TIMP-1), separately and in combination has produced N-TIMP-1 variants with higher binding affinity and specificity for individual MMPs. TIMP-3 is unique in that it inhibits not only MMPs, but also several ADAM (a disintegrin and metalloproteinase) and ADAMTS (ADAM with thrombospondin motifs) metalloproteinases. Inhibition of the latter groups of metalloproteinases, as exemplified with ADAMTS-4 (aggrecanase 1), requires additional structural elements in TIMP-3 that have not yet been identified. Knowledge of the structural basis of the inhibitory action of TIMPs will facilitate the design of selective TIMP variants for investigating the biological roles of specific MMPs and for developing therapeutic interventions for MMP-associated diseases.

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