Impact of climatic conditions on the parameters of failure flow of military vehicles

Author(s):  
Nikolaj Dobrzinskij ◽  
Algimantas Fedaravicius ◽  
Kestutis Pilkauskas ◽  
Egidijus Slizys

Relevance of the article is based on participation of armed forces in various operations and exercises, where reliability of machinery is one of the most important factors. Transportation of soldiers as well as completion of variety of tasks is ensured by properly functioning technical equipment. Reliability of military vehicles – armoured SISU E13TP Finnish built and HMMWV M1025 USA built were selected as the object of the article. Impact of climatic conditions on reliability of the vehicles exploited in southwestern part of the Atlantic continental forest area is researched by a case study of the vehicles exploitation under conditions of the climate of Lithuania. Reliability of military vehicles depends on a number of factors such as properties of the vehicles and external conditions of their operation. Their systems and mechanisms are influenced by a number of factors that cause different failures. Climatic conditions represent one of the factors of operating load which is directly dependent on the climate zone. Therefore, assessment of the reliability is started with the analysis of climatic factors affecting operating conditions of the vehicles. Relationship between the impact of climatic factors and failure flow of the vehicles is presented and discussed.

Author(s):  
B. Pychkov ◽  
Т. Kopeykina

Artificial cold is widely used in various industries and agriculture, transportation, air conditioning systems and many other fields of science and technology. High-quality equipment for the production of cold is also important for the technical equipment of the Armed Forces, because it is sometimes necessary to provide certain temperature conditions for the reliable operation of electronic means for various purposes and electronic equipment of weapons. In a hot climate, there is a need to create comfortable conditions for the personnel of the units, as well as ensuring quality storage of food and water. An important device of any refrigeration machine is the condenser of coolant, which significantly determines its efficiency. Recently, much attention is paid to the study and application of mixtures of known refrigerating agents along with single-component substances. It is shown that in certain cases, mixtures of coolants can improve the volumetric and energy parameters of low-temperature installations and obtain this effect without significant structural changes. This is very promising for mobile installations, including military ones, which have to work in various climatic conditions that require adjustment of cooling capacity. A promising working substance of bi-cooling plants is a binary non-azeotropic mixture of freons-12 and 22. The mode of operation of bi-coolant capacitors differs from the modes of operation of one-component devices, which is explained by the mutual influence of heat and mass transfer processes occurring together in the boundary vapor layer at the condensation surface and the condensate film. This circumstance makes the strict calculation of the heat exchange surface of capacitors quite difficult. In such calculations, it is necessary to use data on the thermophysical properties of the mixture in both the steam and liquid phases. However, these data cannot be found in the literature for all promising two-component refrigerants. Data on the vapor-liquid equilibrium of mixtures are also required. Taking into account the above, in this work, an experimental study process of the condensation of pure freons-12 and 22, as well as their mixtures on a twenty-row sheaf of ribbing tubes, was carried out. The article describes the construction of the experimental capacitor and the method of measurement. The obtained experimental formulas for calculating condensation on single horizontal pipes and on a sheaf of horizontal pipes, as well as on the impact of the rows of condenser pipes on heat transfer are presented. The obtained data are compared with the literature data. The results of the experiment allowed us to propose a simplified engineering method for calculating the condensation surface of multi-tube bi-coolant capacitors. In addition, a method for calculating the basic geometric parameters of such shell-and-tube capacitors in the industrial load range is proposed.


2014 ◽  
Vol 36 (2) ◽  
pp. 185 ◽  
Author(s):  
Fang Chen ◽  
Keith T. Weber

Changes in vegetation are affected by many climatic factors and have been successfully monitored through satellite remote sensing over the past 20 years. In this study, the Normalised Difference Vegetation Index (NDVI), derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Terra satellite, was selected as an indicator of change in vegetation. Monthly MODIS composite NDVI at a 1-km resolution was acquired throughout the 2004–09 growing seasons (i.e. April–September). Data describing daily precipitation and temperature, primary factors affecting vegetation growth in the semiarid rangelands of Idaho, were derived from the Surface Observation Gridding System and local weather station datasets. Inter-annual and seasonal fluctuations of precipitation and temperature were analysed and temporal relationships between monthly NDVI, precipitation and temperature were examined. Results indicated NDVI values observed in June and July were strongly correlated with accumulated precipitation (R2 >0.75), while NDVI values observed early in the growing season (May) as well as late in the growing season (August and September) were only moderately related with accumulated precipitation (R2 ≥0.45). The role of ambient temperature was also apparent, especially early in the growing season. Specifically, early growing-season temperatures appeared to significantly affect plant phenology and, consequently, correlations between NDVI and accumulated precipitation. It is concluded that precipitation during the growing season is a better predictor of NDVI than temperature but is interrelated with influences of temperature in parts of the growing season.


2021 ◽  
Vol 44 (1) ◽  
pp. 63-72
Author(s):  
D. Sh. Sharipov

The study of the processes occurring deep in the earth's crust has always been a relevant research topic. The results of these studies allowed development and safe mining of mineral deposits in various conditions. The growth in the consumption of extracted resource and the increase in the scale of mining are forcing enterprises to search for the solutions to complex engineering and technical problems, one of which is the problem of displacement of rock masses and the earth's surface in industrial production-affected areas including tailings dams. The purpose of this study is to improve the operation safety of tailing dams. The object of the study is embankment dams of dressing plant tailing dumps. The subject of the study is deformation processes occurring in dam bodies and slope surfaces. The main research methods used in the work are: the study of safe operation methods for tailing dams based on the operating conditions of Uchalinskoye tailing dump using the modern methods of stability assessment, analysis and generalization of domestic and foreign experience, as well as the study of current methods of geomechanical monitoring of deformation processes – engineering and geological, geophysical, mine surveying and hydrogeological ones. The article describes geographic, hydrographic, climatic, geological and mining operation conditions of the tailing dump of Uchalinsky GOK (Ore Mining and Processing Plant) JSC. The influence of hydrodynamic and hydrostatic forces on embankment tailing dam stability is substantiated. Based on the data obtained and the research methods used, it is concluded that hydrodynamic and hydrostatic forces are fundamental destructive factors affecting dams. The results of these studies can be applied at the design stage of hydraulic structures, since they will supplement theoretical knowledge about the impact of liquid waste on the safety of tailing dams and earth-filled dams, as well as allow detecting deformation processes at their initial development stage and making decisions on their elimination.


2020 ◽  
Vol 148 ◽  
Author(s):  
B. Tinto ◽  
S. Salinas ◽  
A. Dicko ◽  
T. S. Kagone ◽  
I. Traore ◽  
...  

Abstract Although the African continent is, for the moment, less impacted than the rest of the world, it still faces the risk of a spread of COVID-19. In this study, we have conducted a systematic review of the information available in the literature in order to provide an overview of the epidemiological and clinical features of COVID-19 pandemic in West Africa and of the impact of risk factors such as comorbidities, climatic conditions and demography on the pandemic. Burkina Faso is used as a case study to better describe the situation in West Africa. The epidemiological situation of COVID-19 in West Africa is marked by a continuous increase in the numbers of confirmed cases. This geographic area had on 29 July 2020, 131 049 confirmed cases by polymerase chain reaction, 88 305 recoveries and 2102 deaths. Several factors may influence the SARS-CoV-2 circulation in Africa: (i) comorbidities: diabetes mellitus and high blood pressure could lead to an increase in the number of severe cases of SARS-CoV-2; (ii) climatic factors: the high temperatures could be a factor contributing to slow the spread of the virus and (iii) demography: the West Africa population is very young and this could be a factor limiting the occurrence of severe forms of SARS-CoV-2 infection. Although the spread of the SARS-CoV-2 epidemic in West Africa is relatively slow compared to European countries, vigilance must remain. Difficulties in access to diagnostic tests, lack of hospital equipment, but also the large number of people working in the informal sector (such as trading, businesses, transport and restoration) makes it difficult to apply preventive measures, namely physical distancing and containment.


2020 ◽  
Vol 164 ◽  
pp. 08006
Author(s):  
Marat Kuzhin ◽  
Ekaterina Chepik ◽  
Angelina Baranova

In this research the influence of natural and climatic conditions on the organization of construction production are examined. Our purpose was to identify the nature of the dependence of the duration of construction work on natural and climatic factors. The analysis of normative and technical documentation in terms of accounting for the influence of natural and climatic factors was made. The system of estimation of influence of natural conditions on preparatory, ground, facade, roofing works, and also the appliance of monolithic structures, installation of prefabricated ferroconcrete items, and on works – implementation of internal finishing is offered. It was estimated, that the norms of construction production take into account a certain number of natural and climatic factors affecting the performance of work, but most of these factors have not yet been given in the normative and technical documentation. It is necessary to study this issue more comprehensively and to establish exact dependences on natural and climatic conditions, which will allow to quantify these factors already while calculating. This is necessary to compile more accurate calendar plans and schedules of production of works, as close as possible to real conditions. The study of this issue is one of the most important issues in the design of construction production. With insufficient consideration of these factors, the final actual figures are very different from the projected ones, which also lead to an increase in the cost of construction and installation work and the duration of their implementation. Taking into consideration the influence of natural and climatic factors will allow planning construction production more accurate.


2014 ◽  
Vol 17 (4) ◽  
pp. 173-185 ◽  
Author(s):  
Emilia Modranka ◽  
Jadwiga Suchecka

Health of the population is one of the basic factors of social development. The results of empirical studies indicate a number of factors determining the level of health of the population related to access to health care services, the level of environmental pollution and the wealth of society. It must be assumed that the observed disparities in the health depend on distributions of particular determinants. The aim of the article is to assess the significance of the main factors affecting the occurrence of spatial disparities in the level of social development districts NTS-4 in terms of health of the population. The analysis was based on estimates of the Spatial Durbin Model (SDM) which takes into account the impact of neighborhood spatial units on level of dependent variable and the explanatory variables. The size of the level of social development in terms of health of the population in the study was approximate by the aggregate value of the index, which is the local component of the Local Human Development Index LHDI.


1999 ◽  
Vol 122 (4) ◽  
pp. 611-616 ◽  
Author(s):  
Daniel B. Olsen ◽  
Charles E. Mitchell

Current research shows that the only hazardous air pollutant of significance emitted from large bore natural gas engines is formaldehyde CH2O. A literature review on formaldehyde formation is presented focusing on the interpretation of published test data and its applicability to large bore natural gas engines. The relationship of formaldehyde emissions to that of other pollutants is described. Formaldehyde is seen to have a strong correlation to total hydrocarbon (THC) level in the exhaust. It is observed that the ratio of formaldehyde to THC concentration is roughly 1.0–2.5 percent for a very wide range of large bore engines and operating conditions. The impact of engine operating parameters, load, rpm, spark timing, and equivalence ratio, on formaldehyde emissions is also evaluated. [S0742-4795(00)01004-8]


2020 ◽  
Vol 2020 (2) ◽  
pp. 21-26
Author(s):  
Sergey Vladimirovich Golovko ◽  
Dmitry Anatolyevich Zadorkin

The article outlines the problem of the influence of climatic factors on the efficiency of solar panels operation. Not long ago the idea of free electricity seemed incredible. However, the development of technologies rapidly progresses, and the alternative energy captures more and more supporters every day. The popularity of solar panels is growing quite rapidly, since photovoltaic converters are an efficient source of electricity. But for more efficient operation of solar cells it is necessary to create the specific conditions, taking into account the location of the unit. There have been considered the factors of more efficient operation of the photovoltaic converters: the hash climatic conditions and the intensity of solar radiation depending on the angle of reducing the impact of the solar rays onto the solar cell surface.


Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1967
Author(s):  
Bianca Enaru ◽  
Georgiana Drețcanu ◽  
Teodora Daria Pop ◽  
Andreea Stǎnilǎ ◽  
Zorița Diaconeasa

Anthocyanins are secondary metabolites and water-soluble pigments belonging to the phenolic group, with important functions in nature such as seed dispersal, pollination and development of plant organs. In addition to these important roles in plant life, anthocyanins are also used as natural pigments in various industries, due to the color palette they can produce from red to blue and purple. In addition, recent research has reported that anthocyanins have important antioxidant, anticancer, anti-inflammatory and antimicrobial properties, which can be used in the chemoprevention of various diseases such as diabetes, obesity and even cancer. However, anthocyanins have a major disadvantage, namely their low stability. Thus, their stability is influenced by a number of factors such as pH, light, temperature, co-pigmentation, sulfites, ascorbic acid, oxygen and enzymes. As such, this review aims at summarizing the effects of these factors on the stability of anthocyanins and their degradation. From this point of view, it is very important to be precisely aware of the impact that each parameter has on the stability of anthocyanins, in order to minimize their negative action and subsequently potentiate their beneficial health effects.


2019 ◽  
pp. 112-119
Author(s):  
Irina G. Silina ◽  
Evgeny A. Gilmiyarov ◽  
Vadim A. Ivanov

The article deals with the operating conditions of Sobolevo — Petropavlovsk-Kamchatsky gas pipeline. Much attention is given to technical assessment of aboveground crossings of this gas pipeline. We report key climatic conditions and other factors affecting gas pipeline operation. Also, we present the results of aboveground crossings partial monitoring and detect the matters of their condition significant degradation.


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