Assessment of the technical condition of mines with mechanical fuses

2021 ◽  
Vol 2021 (1) ◽  
pp. 1-12
Author(s):  
Adam Kubecki ◽  
Cezary Śliwiński ◽  
Janusz Śliwiński ◽  
Ireneusz Lubach ◽  
Leszek Bogdan ◽  
...  

Contemporary armed conflicts reveal that the use of effective mine barriers has a significant impact on the course of hostilities. Therefore, the Polish Armed Forces selected reliable and effective explosive ordnance as a priority, both newly-acquired material and those currently in operation. For this reason, among others, strict supervision over the technical condition of mines is exercised, in particular during their long-term storage. The reasons behind the increased mine unreliability may include physical and chemical changes in the construction materials used (corrosion, deformations, loss of strength properties), deterioration of the physicochemical properties of the main charge, booster and primer-detonator, inadequate technical condition of the safety components, or the failure of mine fuse mechanisms. In order to assess the mine's operational reliability, each mine fuse subassembly is examined and then a check of the entire assembled mine is performed. This requires proper planning of the full test cycle and the use of inspected and calibrated measuring devices and test stands enabling the precise adjustment of mechanical and climatic stress parameters.

2018 ◽  
Vol 178 ◽  
pp. 09019
Author(s):  
Oleg Primin ◽  
Vladimir Orlov

The growing deterioration and unsatisfactory technical condition of the pipes of water supply and wastewater disposal networks in Russian cities and other inhabited localities, as well as limited (under the conditions of Russian housing and utilities sector reforming) funding of pipeline renovation and rehabilitation have considerably aggravated the problem of pipe reliability provision. These factors make pipe renovation and rehabilitation quite a topical issue. A very promising trend in the field of pipeline construction and renovation named “trenchless technologies” has been commonly used in the world in recent years. A wide choice of different construction materials used for pipe rehabilitation appeared in the market. Under the conditions of densely built-up urban areas, these methods are of great current interest for city utilities. Quite different pipe renovation methods are used currently but the most popular method comprises the application of a flexible polymeric hose that makes it possible to form a new composite pipe inside the old one. The wall thickness of such a hose is among the important factors that have an impact on the cost and efficiency of pipe renovation methods based on the application of flexible polymeric hoses. The hose wall thickness is determined on the basis of calculating the “soil - old pipe - hose” system in view of its static stability. The article describes the technology for the trenchless rehabilitation of water pipes and the strength calculation method for a “pipe - polymeric hose” double-layer structure.


Author(s):  
O. Semenenko ◽  
O. Vodchyts ◽  
V. Koverga ◽  
R. Lukash ◽  
O. Lutsenko

The introduction and active use of information transmission and storage systems in the Ministry of Defense (MoD) of Ukraine form the need to develop ways of guaranteed removal of data from media after their use or long-term storage. Such a task is an essential component of the functioning of any information security system. The article analyzes the problems of guaranteed destruction of information on magnetic media. An overview of approaches to the guaranteed destruction of information on magnetic media of different types is presented, and partial estimates of the effectiveness of their application are given by some generally accepted indicators of performance evaluation. The article also describes the classification of methods of destruction of information depending on the influence on its medium. The results of the analysis revealed the main problems of application of software methods and methods of demagnetization of the information carrier. The issue of guaranteed destruction of information from modern SSD devices, which are actively used in the formation of new systems of information accumulation and processing, became particularly relevant in the article. In today's conditions of development of the Armed Forces of Ukraine, methods of mechanical and thermal destruction are more commonly used today. In the medium term, the vector of the use of information elimination methods will change towards the methods of physical impact by the pulsed magnetic field and the software methods that allow to store the information storage device, but this today requires specialists to develop new ways of protecting information in order to avoid its leakage.


Author(s):  
Ian Park

The introduction sets out the broad questions to be addressed, namely: do states have right to life obligations during armed conflict; if so, what are these obligations; when do they apply, and in respect of whom; and how can states best ensure compliance with these obligations? The introduction also provides a précis of each chapter and the themes explored therein. Additionally, it makes reference to the fact that UK armed forces doctrine and procedures in respect of recent armed conflicts will be used as examples to explore the issues under consideration in the book. The aim is also to proffer a view on where the current UK procedures do not comply with the state’s right to life obligations and how this can be rectified.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2482
Author(s):  
Jarosław Konior ◽  
Mariusz Rejment

The degree of technical wear of old buildings, which are made of basic materials (cement, concrete, steel, timber, plaster, brick) using traditional technology, is expressed by the size and intensity of damage to their elements. The topic of the research concerns old residential buildings from the turn of the 19th and 20th centuries, which are located in the downtown district of Wroclaw, Poland. The descriptive analysis and the analysis of the definitions of defects that occur in the elements of residential buildings, which were performed as random analyzes, do not allow defects to be considered as measurable variables at a level of visual investigation. The major drawback of the method that is used by experts when assessing the technical condition of civil engineering buildings is that it does not numerically express the magnitude (strength) of the defects. Therefore, an attempt was made to numerically express the relationship (if such a relationship exists) between the occurred defects of buildings and the extent of their technical wear process. When calculating the strength of this relationship, the method of determining the point biserial correlation coefficient for the measurable property and the dichotomous property was used. It was found that the direction of the relation is right-hand for all the tested building elements, but the strength of the correlation between the detected defects and technical wear shows a considerable span and depends on the conditions of the apartment house’s maintenance. As a rule, damage caused by water penetration and moisture penetration always shows correlations of at least moderate strength.


Radiocarbon ◽  
2019 ◽  
Vol 61 (5) ◽  
pp. 1221-1228
Author(s):  
Naoto Fukuyo ◽  
Yusuke Yokoyama ◽  
Yosuke Miyairi ◽  
Yusuke Igarashi

ABSTRACTWe analyzed rare wooden Komainu found at Akagami Shrine in Akita prefecture, Japan. The formation of historical objects is often thoroughly recorded in documents, although the formation age of this particular Komainu sculpture is still unknown due to its antiquity. Thus, age determination exercises have been conducted using radiocarbon (14C)-wiggle-matching techniques. Although only a limited quantity was available for sampling, we have successfully measured 14C samples in the sculptures along with several sets of tree rings. We interpret the Komainu sculptures age considering the age of the trees and the result obtained from the wooden construction materials used for the Akagami shrine. The results obtained from Komainu show a range from 550 CE to 1020 CE, which is consistent with the dates of the shrine’s formation. Thus, the multiple 14C-wiggle-matching method can determine precise calendar ages of wood, as well as provide some supportive information for the periods when there are no reliable historical documents.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3835
Author(s):  
Robert Dylewski ◽  
Janusz Adamczyk

The energy efficiency of the construction sector should be determined by the cleanliness of the environment and, thus, the health of society. The scientific aim of this article was to develop a methodology for determining the optimum thickness of thermal insulation, taking into account both economic and ecological aspects and considering both heating and cooling costs. The method takes into account the number of degree days of the heating period, as well as the number of degree days of the cooling period. Variants in terms of different types of thermal insulation, various types of construction materials for building walls, climatic zones and heat sources, were taken into consideration. In order to find the optimum thicknesses of thermal insulation, both in economic and ecological terms, a metacriterion was used. The optimum thicknesses of thermal insulation with the use of the metacriterion were obtained in the range of 0.11–0.55 m. It was observed that the values of the optimum heat transfer coefficients for economic and ecological reasons do not depend on the type of construction materials used for vertical walls. The type of applied heat source is of the greatest importance for the size of the economic and ecological benefits. The proposed mathematical model for determining the optimum thickness of thermal insulation with the use of a metacriterion is a kind of generalization of earlier models from the literature.


Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 276
Author(s):  
Nisar Ali Khan ◽  
Giorgio Monti ◽  
Camillo Nuti ◽  
Marco Vailati

Infilled reinforced concrete (IRC) frames are a very common construction typology, not only in developing countries such as Pakistan but also in southern Europe and Western countries, due to their ease of construction and less technical skills required for the construction. Their performance during past earthquakes has been in some cases satisfactory and in other cases inadequate. Significant effort has been made among researchers to improve such performance, but few have highlighted the influence of construction materials used in the infill walls. In some building codes, infills are still considered as non-structural elements, both in the design of new buildings and, sometimes, in the assessment of existing buildings. This is mainly due to some difficulties in modeling their mechanical behavior and also the large variety of typologies, which are difficult to categorize. Some building codes, for example, Eurocode, already address the influence of infill walls in design, but there is still a lack of homogeneity among different codes. For example, the Pakistan building code (PBC) does not address infills, despite being a common construction technique in the country. Past earthquake survey records show that construction materials and infill types significantly affect the seismic response of buildings, thus highlighting the importance of investigating such parameters. This is the object of this work, where a numerical model for infill walls is introduced, which aims at predicting their failure mode, as a function of some essential parameters, such as the friction coefficient between mortar and brick surface and mortar strength, usually disregarded in previous models. A comprehensive case study is presented of a three-story IRC frame located in the city of Mirpur, Pakistan, hit by an earthquake of magnitude 5.9 on 24 September 2019. The results obtained from the numerical model show good agreement with the damage patterns observed in situ, thus highlighting the importance of correctly modeling the infill walls when seismically designing or assessing Pakistani buildings that make use of this technology.


1978 ◽  
Vol 18 (206) ◽  
pp. 274-284 ◽  
Author(s):  
Yves Sandoz

The events in Lebanon and the despatch of a UN armed force to keep the peace there brings into focus a problem which cannot be ignored, the application of international humanitarian law in armed conflicts. This problem has two aspects:— What is the nature of the armed forces which the UN commits or can commit at the present time?— To what extent are these armed forces obliged to apply humanitarian law?


2013 ◽  
Vol 739 ◽  
pp. 292-297 ◽  
Author(s):  
Vit Křivý ◽  
Petr Konečný ◽  
Viktor Urban

The paper deals with a statistical evaluation of the real material properties of weathering steels used for the construction of motorway bridges in the Czech Republic between 2001 and 2007. The statistical analysis and evaluation is carried out for a range of hot rolled plates made of S355J2W weathering steel. The paper contains an evaluation of the strength properties of the steel and its chemical composition. The paper also contains derived real values of partial factors of materials corresponding to the relevant reliability classes RC1 to RC3 pursuant to the European standard EN 1990.


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