angular characteristic
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Vestnik IGEU ◽  
2021 ◽  
pp. 38-46
Author(s):  
A.I. Tikhonov ◽  
A.V. Stulov ◽  
A.V. Likhachova ◽  
M.I. Nikiforov ◽  
I.V. Eryomin

Modern technologies of generative design and digital twins of electrical devices are based on the use of field models, as a rule, three-dimensional ones. Also, it is possible to solve design problems and to simulate accurately electrical machines and devices based on a set of 2D models of physical fields. Application of automatically generated field models in modern systems of engineering analysis during the design and optimization of electrical machines and devices makes it possible to get rid of many assumptions and outdated empirical and semi-empirical dependencies, as well as to reach a new methodological level of design theory, characterized by a unified approach to the calculation of various devices. Therefore, the purpose of this article is to develop a methodology to design a synchronous motor of an atypical design, based on the use of two-dimensional models of a stationary magnetic field at different design stages and allowing a solution to be obtained even in the absence of preliminary studies and recommendations. The finite element method is used implemented by means of the EMLib library (author's development), which allows calculating magnetic fields in a 2D formulation. Also, methods of the theory of synchronous machines and object-oriented programming in VBA in the MSExcel environment are used. Elements of digital twin technology and generative design are used while developing the methodology and design system. A method to design an end-face synchronous motor has been developed using automatically generated set of field models at the stages of choosing the height of a permanent magnet, calculating the parameters of an equivalent circuit, and an angular characteristic. Based on the popular MSExcel package, a system to design an end-face synchronous motor has been developed. The EMLib library has been implemented into the system, it allows using the results of calculating the magnetic field in the key design operations. The end-face synchronous motor has been designed and tested on the base of the developed system. The results of the research can be used during the development of methods to design electrical machines and devices of arbitrary, including non-standard design, for which approved algorithms for engineering analysis do not exist.


2020 ◽  
Vol 47 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Viktoriia Komlyk ◽  
Viktor Brygadyrenko

AbstractThis article discusses the effect of soil salinity on the variability of Bembidion (Notaphus) varium (Oliver, 1795). The authors of the article collected imagoes of this species in five ecosystems that differed in soil salinity; 13 linear characteristics, one angular characteristic and 6 morphometric indices were measured. Significant changes in six linear parameters of B. varium (body length, head length and width, width of prothorax between front angles, maximum width of prothorax and elytra width) and two morphometric indices are observed in the considered ecosystems. Soil salinity probably has the most impact on the variability of these characteristics. However, the influence of other important natural and anthropogenic factors is not ruled out. Significant differences between the sexes are observed for all linear parameters: females of B. varium are larger than males. There are no differences between males and females in morphometric indices. The head width, prothorax length and width, elytra length and width depend on the body length of B. varium individuals. The morphological variability of B. varium under the influence of other environmental factors needs further research.


2019 ◽  
Vol 27 (3) ◽  
pp. 250-269
Author(s):  
V. O. Komlyk ◽  
V. V. Brygadyrenko

Morphological variability is the result of interaction between genetic diversity of the population and environmental selection. Despite the large number of studies of morphological variability of ground beetles, there is very little research dedicated to influence of environmental factors on it. This article discusses the influence of natural and anthropogenic factors on the variability of Bembidion minimum (Fabricius, 1792). B. minimum is a West Palearctic species which is distributed in North Africa, Europe, Western Asia. It is a macropterous species that lives in humid biotopes along the shores of seas, rivers and standing water bodies. 410 specimens were collected from 12 ecosystems differing by plant cover, degree of litter development, mechanical composition of the soil, mineralization and acidity of soil solution, type and intensity of anthropogenic impact. 13 linear characteristics, one angular characteristic, density of elytra puncturing and contrast of spots on the beetles’ elytra were measured. Additionally 6 morphometric indices were calculated. More than a third of the variability of imagoes in the studied populations was found to be determined by the general body size. Sexual dimorphism was observed on all linear parameters and most morphometric indices. Females do not differ from males in the back angles of the prothorax. Natural and anthropogenic factors to a greater or lesser degree were shown to affect the morphological variability of B. minimum: soil acidity and mineralization have the greatest impact. The soil acidity causes significant variability of most linear parameters; mineralization – body length, head length, prothorax length and width, elytra width. Plant cover and mechanical composition of the soil have a slight impact on imago morphology. The type and structure of vegetation significantly affect head width, prothorax length and width, and the mechanical composition of the soil – body length and head length. Degree of litter development does not cause significant changes in the linear dimensions of beetles. With thickening of the litter the posterior spots on the elytra become brighter, they have sharper contours, and density of elytra puncturing also changes. The mean value of the back angles is affected by the herb layer of meadow vegetation, soil mineralization and acidity. The variability of morphometric indexes under the influence of natural factors was found to be lower than variability of linear characteristics. The recreational load and cattle grazing cause similar changes in linear measurements and morphometric indexes of B. minimum. With escalation of these factors, the body length, length and width of elytra of both females and males decrease. Assessing the natural morphological variability of populations in ecosystems whose environmental factors are within extreme and sub-extreme values for a given population is a promising direction of research in modern ecology.


2019 ◽  
Vol 27 (1) ◽  
pp. 21-25
Author(s):  
V. O. Komlyk ◽  
V. V. Brygadyrenko

Bembidion (Talanes) aspericolle (Germar, 1829) is a Western Palearctic species which lives on the shores of the Atlantic Ocean, the Mediterranean, Black and Caspian Seas and saline inland habitats from Central Europe to Central Asia. Anthropogenic impact is one of the most important environmental factors affecting the morphological variability of ground beetles. The objective of our research is assessment of the morphological variability of this species in three ecosystems differing by intensity of anthropogenic impact. 13 linear characteristics, one angular characteristic, density of pores on the prothorax and elytra, contrast of spots on the beetles’ elytra were measured, and 6 morphometric indices were calculated. The mean value of body length in females is more than in males in the studied populations. In the ecosystem with high anthropogenic pressure, female body length is shorter by 3.7% and elytra length is shorter by 6.0% than in females in the ecosystem with low anthropogenic impact. Differences between populations in the body length of males are not significant. In the ecosystem with high anthropogenic transformation, sexual dimorphism is observed only on head and prothorax width. The ratio of maximum width of elytra to maximum prothorax width decreases significantly with increasing anthropogenic load. The impact of anthropogenic factors on the ecosystem produces significant changes in elytra length and head width of B. aspericolle and in four of the six morphometric indices. It is reasonable to use these morphometric characteristics of B. aspericolle adults in bioindication. The complex of anthropogenic factors does not have a significant impact on the value of anterior and posterior angles of prothorax, density of prothorax and elytra puncturing and contrast of the light spots at the top of the elytra. The sex of the specimen influences all linear characteristics. The absence of significant differences in morphometric indices between males and females shows that the body proportions of the beetles remain unchanged and only linear dimensions vary. Research on the morphological variability of B. aspericolle is important for understanding microevolutionary processes in populations of beetles under anthropogenically induced changes in the environment.


Author(s):  
Aida Sheikh ◽  
Hassan Khotanlou

There are many ways to recognize the identity of individuals and authenticate them and the modern world still is looking for unique biometric features of humans. The recognition and authentication of individuals with the help of their handwriting is regarded as a research topic in recent years. It is widely used in the field of security, legal, access control to systems and financial activities. This thesis tries to examines the identification and authentication of individuals in Persian (Farsi) handwritten texts so that the identity of the author can be determined with a handwritten text, and in the authentication problem, with having two handwritten texts, it is determined that whether both manuscripts belong to a specific person or not. The proposed system for recognizing the identity of the author in this study can be divided into two main parts: one part is intended for training and the other for testing. To assess the performance of introduced characteristics, the Hidden Markov Model (HMM) is used as the classifier; thus, a model is defined for each angular characteristic. The defined angular models are connected by a specific chain network to form a comprehensive database for classification. This database is then used to determine and authenticate the author.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Ali Abd El-Salam Ibrahim ◽  
Mostafa Abd El-Fattah El-Aasser

The silicon solar cells are largely insensitive to gamma-radiation because the radiation passes through solar cells without imparting all of its energy. In order to enhance the sensitivity to radiation, the solar cells are coupled to CsI(Tl) scintillator. With the help of n+pp++ PESC monocrystalline silicon solar cells and CsI(Tl) scintillators, a gamma-radiation test monitor (TM) is developed. Due to safety concerns, a convenience relatively intense60Co gamma-source is used as a suitable substitute for spent fuel. Two designs made of two representative arrays of monocrystalline solar cells are suggested. The induced current and voltage generated by these solar cells are measured. The temperature dependence of the induced current and the angular characteristic of the TM, for both designs, are presented. In comparison to conventional gamma-ray sensors, the Si solar cells exhibited better performance than the conventional types. Design II is found to be more efficient than I and superior performance for all of the measured parameters is obtained.


1998 ◽  
Vol 07 (06) ◽  
pp. 659-667 ◽  
Author(s):  
Prithipal Singh ◽  
H. Khushnood

An attempt has been made to study the angular characteristic of relativistic charged particles produced in 4.5 A GeV/c 12C-emulsion collisions. The dependence of these characteristics on the multiplicity of the relativistic particles, Ns, has also been investigated. The results reveal that the angular distributions of relativistic particles do not depend on Ns, except at small angles where contribution of singly charged particles fragments enhances the number of relativistic charged particles. It is also observed that the maximum of pseudorapidity, η and <η> distributions, shifts towards the lower value of η with increasing multiplicity of Ns. The study of the rapidity dispersion of relativistic charged particles reveals that the clusterization effect occurs significantly among the final state relativistic particles produced in heavy ion interactions.


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