scholarly journals Analysis of basic concepts of advanced engines for supersonic civil aircraft on the basis of foreign designers’ experience

2021 ◽  
Vol 20 (3) ◽  
pp. 24-36
Author(s):  
A. D. Alendar ◽  
A. N. Grunin ◽  
M. V. Siluyanova

The work contains the results of a study of the basic design concepts of advanced engines for supersonic civil aircraft, carried out in order to make a forecast for the development of aviation technology, taking into account the experience of foreign designers. Engine designs are presented that are considered to be the most rational ones from the point of view of achieving high technical and economic parameters in the range of cruise Mach numbers from 1.2 to 5. Advantages and disadvantages of various engine designs, as well as issues of engine regulation at different flight modes, are discussed. The parameters of some engines being developed and studied at present for supersonic civil aircraft are presented. The analysis of the designs shows that an increase in the cruise Mach number leads to a complication of engine designs in the direction of an increase in the number of controlled elements, the number of working fluid flow paths, a complication of the architecture of turbomachines, as well as in the direction of using combined schemes and alternative fuels. The aspiration to meet new reinforced ecological requirements through the use of new, complex engine designs that differ significantly from traditional gas turbine engines will inevitably entail additional technical risks due to the insufficient level of technological readiness of most of the new controlled units.

2020 ◽  
Vol 5 (4) ◽  
pp. 202-209
Author(s):  
Alexander Topal ◽  
◽  
Iryna Holenko ◽  
Luidmyla Haponych ◽  
◽  
...  

For the municipal solid waste (MSW) to be used in a proper way, it is necessary to implement clean technologies capable of thermal treatment of MSW and RDF in order to produce heat and electricity while meeting current ecological requirements. Nowadays, a number of technologies for MSW/RDF thermal treating are being used worldwide. Among them, the most proven technologies, applicable for industrial introduction, have been considered while analyzing their advantages/ disadvantages accounting for local conditions of Ukraine.


2020 ◽  
Author(s):  
Stéphane Goria ◽  
Louise Dupet ◽  
Maëva Négroni ◽  
Gabriel Sega ◽  
Philippe Arnoux ◽  
...  

BACKGROUND most serious games and other game-based tools are designed as digital games or escape games. They are designed for learning or sometimes in the field of medicine as an aid to care. However, they can also be seen as an aid to research, in our case, to evaluate the advantages and disadvantages of imaging techniques for cancer detection. OBJECTIVE we present a case study of action research on the design of a serious board game intended to consider the advantages and weaknesses of a diagnostic method in a different ways. The goal was to better understand the principles of designing a tool using game or play. METHODS we explicitly implemented another process than gamification to develop a structure reminiscent of the game to highlight the strengths and weaknesses of different imaging techniques from the point of view of the respondents (in this case specialists not directly involved in the project). Based on this feedback and the scientific literature on this subject, we detail the main categories of games and games developed for serious use in order to understand their differences. Concerning the cancer research part to which game contributes, our method is based on questions asked to experts and practitioners of this specialty. RESULTS an expert point of view translation tool in the form of a game has been realized to apprehend a research in a different way. CONCLUSIONS we show with the help of a diagram, some possible design paths leading to this type of design result including two hidden dimensions to consider (the awareness of the game or play by the "player" and his role as a contributor or recipient).


Author(s):  
Doriana Landi ◽  
Marta Ponzano ◽  
Carolina Gabri Nicoletti ◽  
Gaia Cola ◽  
Gianluca Cecchi ◽  
...  

AbstractRestrictions in the access to healthcare facilities during COVID-19 pandemic have raised the need for remote monitoring of chronic medical conditions, including multiple sclerosis (MS). In order to enable the continuity of care in these circumstances, many telemedicine applications are currently tested. While physicians’ preferences are commonly investigated, data regarding the patients’ point of view are still lacking. We built a 37 items web-based survey exploring patients’ propensity, awareness, and opinions on telemedicine with the aim to evaluate the sustainability of this approach in MS. Analysing 613 questionnaires out of 1093 that were sent to persons with MS followed at the Multiple Sclerosis Center of Tor Vergata University, Rome, we found that more than half of respondents (54%) were open to having a televisit. Propensity toward telemedicine significantly depended on having a higher income (p = 0.037), living farther from the center (p = 0.038), using computer and tablet (p = 0.010) and using the Internet for other remote activities (p < 0.001), conversely it was not influenced by any specific disease characteristics (i.e. degree of disability). The main advantages and disadvantages of televisit reported by participants were respectively saving time (70%) and impossibility to measure physical parameters (71%). Although the majority of respondents are in favour of televisit, so far this approach is restricted to those displaying better socioeconomic conditions and higher familiarity with technology. Implications of the study are that telemedicine platforms should be better tailored to patients’ demands in order to spread the use of telemedicine, to enhance usability and to increase patients’ adherence.


2001 ◽  
Vol 54 (1) ◽  
pp. 69-92 ◽  
Author(s):  
Igor V. Andrianov ◽  
Jan Awrejcewicz

In this review article, we present in some detail new trends in application of asymptotic techniques to mechanical problems. First we consider the various methods which allows for the possibility of extending the perturbation series application space and hence omiting their local character. While applying the asymptotic methods very often the following situation appears: an existence of the asymptotics ε → 0 implies an existence of the asymptotics ε → ∞ (or, in a more general sense, ε → a and ε → b). Therefore, an idea of constructing a single solution valid for a whole interval of parameter ε changes is very attractive. In other words, we discuss a problem of asymptotically equivalent function constructions possessing for ε → a and ε → b a known asymptotic behavior. The defined problems are very important from the point of view of both theoretical and applied sciences. In this work, we review the state-of-the-art, by presenting the existing methods and by pointing out their advantages and disadvantages, as well as the fields of their applications. In addition, some new methods are also proposed. The methods are demonstrated on a wide variety of static and dynamic solid mechanics problems and some others involving fluid mechanics. This review article contains 340 references.


2006 ◽  
Vol 53 (3) ◽  
pp. 313-334 ◽  
Author(s):  
Emilija Beker

The choice of an adequate exchange rate regime proves to be a highly sensitive field within which the economic authorities present and confirm themselves. The advantages and disadvantages of fixed and flexible exchange rate regimes, which have been quite relativized from the conventional point of view, together with simultaneous, but not synchronized effects of structural and external factors, remain permanently questioned throughout a complex process of exchange rate regime decision making. The paper reflects the attempt of critical identification of the key exchange rate performances with emphasis on continuous non-uniformity and (un)certainty of shelf life of a relevant choice.


10.12737/1575 ◽  
2013 ◽  
Vol 2 (5) ◽  
pp. 25-30 ◽  
Author(s):  
Николайкин ◽  
N. Nikolaykin

The modern directions of environment protection against aircraft influence in the light of International Civil Aviation Organization (IСAO) decisions have been analyzed. Modern priorities in this activity have been revealed, tendencies of development related to international and civil aviation, as well as evolution of ecological requirements to aircraft, civil aviation’s fuel efficiency increase directions and alternative fuels, problems of aviation noise impact on habitat have been considered.


2021 ◽  
Vol 8 (1) ◽  
pp. F11-F18
Author(s):  
S.M. Vaneev ◽  
V.S. Martsynkovskyy ◽  
A. Kulikov ◽  
D.V. Miroshnichenko ◽  
Ya.І. Bilyk ◽  
...  

The creation of energy-saving turbogenerators is an essential component of the development of small energy systems. The gradual growth of interest in distributed electricity generation necessitates the constant improvement of these units. Moreover, they implement a more environmentally friendly generation method than when using microturbine units that use fuel to carry out the work process. Nowadays, turbogenerators are created based on different types of expansion machines, which have their advantages and disadvantages, given in this article. Compared to competitors, vortex expansion machines have good prospects and the necessary potential to expand their research and produce turbogenerators. An experimental vortex expansion machine with a peripheral-lateral channel and ability to change the geometric parameters of its flowing part was created to meet these needs. Experimental studies of the machine were performed on a special stand with air as a working fluid. As a result of the tests, the data were successfully obtained and processed. They are presented in the form of tables and graphical dependencies. The nature of the influence of thermodynamic parameters and geometric parameters of the flow part on the efficiency of the vortex expansion machine and turbogenerator based on it to further improve and create new turbogenerators is clarified.


2021 ◽  
Vol 5 (2) ◽  
pp. 128
Author(s):  
Fitria Jalaluddin ◽  
Alfelia Nugky Permatasari

Covid-19 made several countries adopt lock-down policies as an effort to break the chain of spreading the virus. However, this policy greatly affects sectors related to the daily mobility of people, especially the tourism sector which has been most significantly affected by Covid-19. One of the provinces in Indonesia that has experienced a major loss in the tourism sector due to Covid-19 is the Yogyakarta Special Region (DIY). Therefore, the DIY government gradually continues to encourage the tourism sector to resume operations, one of which is by releasing new applications for tourists, namely "Jogja Pass" and "Visiting Jogja" to monitor visitors to tourism destinations in DIY. In this study the author will focus on studying the application "Visiting Jogja". The purpose of this research is to examine the advantages and disadvantages of the "Visiting Jogja" application from the user's point of view, and to find out whether the "Visiting Jogja" application can help restore the confidence of tourists to travel to Yogyakarta. This study uses qualitative research methods, with data collection techniques through direct interviews with 10 respondents as a sample who is determined randomly. The results show that the application "Visiting Jogja" can provide assurance for tourists, which helps generate confidence in users to visit more tourism attractions in Yogyakarta. However, the government's efforts in socializing and promoting the “Visiting Jogja” application to the public are still lacking.


2021 ◽  
Vol 6 ◽  
pp. 4-17
Author(s):  
V.V Koval ◽  
D.V. Miroshnichenko ◽  
O.V. Bogoyavlenska

The article substantiates the importance and problems of determining of such an indicator of the quality of solid fossil fuels, as mechanical strength. The strength of coal depends on a large number of factors (viscosity, brittleness, properties of structural bonds, etc.), the change of which is impossible to take into account. Therefore, the strength of coal in the sample, piece, pack and formation must be represented by some integral index, which inevitably fluctuates around a certain average value and can be determined only approximately. The evaluation of the strength properties of coal should be carried out on the basis of mass tests using statistical methods that allow to calculate the average value and coefficient of variation. Since the strength dispersion is mainly due to the natural inhomogeneity of the coal, the excessive accuracy of the measuring instruments has almost no effect on the statistical characteristics. Laboratory methods of mechanical tests of mine samples, in comparison with full-scale, as a rule, are very accessible and, at qualitative performance of tests, are highly reliable. The properties of coal as an object of enrichment and use are largely related to its physical properties. The physical properties of coal and mineral impurities significantly affect the formation of the main parameters that characterize the particle size distribution and fractional composition, it`s changes during the mining, transportation and enrichment processes. The basic physical and mechanical properties of solid fuels from the point of view of their industrial processing have been listed, the review has been made of the most widespread methods of study of coals mechanical durability and the equipment used for these purposes. The main advantages and disadvantages have been summarized of these methods, as well as their relationship. The factors have been Indicated tinfluencing the mechanical strength of coal. The expediency of using existing methods from the point of view of informativeness for thesphere of its application has been estimated. The methods common in the coal processing industry are considered in more detail. Keywords: coal, solid fuel mining, mechanical strength, determination methods, influencing factors, grinding strength, crushing index. Corresponding author V.V. Koval, e-mail: [email protected]


2001 ◽  
pp. 117-127
Author(s):  
Svetlana Demchenko ◽  

The information base of the study was the works of economists in the field of approaches to assessing the effectiveness of worker’s work. The article is devoted to the development of an algorithm for evaluating labor efficiency, taking into account the improved methodology. The hypothesis of the study is the assumption of increasing the influence of the concept of sustainable economic development on the choice of methods for evaluating the effectiveness of labor resources. Within the framework of this study, the authors consider various concepts for the study of labor efficiency, highlight the advantages and disadvantages of existing approaches and offer their own concept of evaluating labor efficiency from the point of view of the concept of sustainable development. The approbation of the author's methodology is presented on the example of a specific company.


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