- TITLE:
TEMPERATURE INFLUENCE ON CAVITATIONAL MASS TRANSFER IN THE CHANNEL OF LAVAL NOZZLE TYPE
- AUTHOR(S):
O. Luhovskyi, I. Nochnichenko, O. Jakhno, D. Kostiuk
- ABSTRACT:
Based on the results of experimental studies of cavitation treatment of oil in a cavitation device,
hydrodynamic small bubble cavitation was observed. A stand was developed to test the operation of
the device to determine its performance and to visualize the appearance of cavitation. A study of a
hydrodynamic cavitation device showed a significant effect of temperature and as a result of a
change in viscosity to cavitation processes.
- TITLE:
PHYSICAL PROCESSES AND MATERIALS IN HIGH-ENERGY FLUXES PROCESSING
- AUTHOR(S):
P. Petrov, S. Valkov, M. Ormanova, D. Kaisheva, T. Hikov
- ABSTRACT:
The present stage of scientific and technological development is characterized by wide-ranging
and diverse applications of the energy of high-energy fluxes (HEFs), such as electron and photon
beams. The fundamental advantage of HEFs over the conventional heat sources is the possibility to
achieve high energy density on the surface of the component treated, which explains the wide use of
HEFs for welding, heat treatment, surface modification, fabrication of wear- and corrosion-resistant
coatings, etc.
The use of HEFs for modification of metal and alloys widens the capabilities of the techniques
for improving their physical and mechanical properties. In recent years, as the studies on the
development of novel materials have intensified, hybrid techniques of HEFs treatment began to be
widely applied, whereby additional alloying is performed in the treated zone thus achieving a
substantial effect on the physical and mechanical properties of the materials processed.
This work presents results HEFs modification and welding of metals and alloys obtained in
recent years at the Laboratory of Physical Technologies at the Institute of Electronics of the
Bulgarian Academy of Sciences
- TITLE:
COMPENSATION OF DELAY IN MULTIVARIABLE CONTROL SYSTEMS USING THE METHOD OF DYNAMIC GRAPHS
- AUTHOR(S):
A. Kadirova, D.R. Kadirova, Ju.S. Bakhracheva
- ABSTRACT:
In this paper, we study the features and possibilities of dynamic graph models application to
solve the problem of designing multivariable systems with compensation for a time delay influence.
As one of the most important varieties of delayed systems, we consider the water object control
systems. The use of classical methods for calculating controllers for such systems leads to significant
difficulties and requires cumbersome transformations. Developed in this paper, the method of
dynamic graph models is based on the premise that such systems should be considered from the point
of view of discretization not only of signals but also of the system structure. This approach allows to
synthesize the control laws according to the chosen optimality criteria and to take into account the
characteristics and properties of real control objects as closely as possible
- PAGES:
1-
- TITLE:
RESEARCH OF TRANSMISSION LOSS IN RADIOWAVE PROPAGATION EFFECTED BY BUILDING MATERIALS
- AUTHOR(S):
N. D. Tashkov, R. I. Tsvetkov
- ABSTRACT:
This paper researches radio signal transmission through different building materials. The
properties of different building materials under the same conditions were examined and a
comparative analysis performed. Depending on the radio signal frequency, the situation changes
dynamically and this requires the use of different sites to determine the predictive characteristics of
the signal at the receiving point. In addition, a theoretical calculation of the signal attenuation and a
simulation were performed by using the Matlab and WinProp program products. This allows a
comparative analysis of the theoretical and simulation results.
- TITLE:
TABS AND THEIR DISPLAY IN A WEBSITES
- AUTHOR(S):
G. Bidjovski
- ABSTRACT:
The subject of the research in this scientific paper is a description of the tabs which main
function is navigation through the websites, with special emphasis on analyzing different types of
tabs. The important part of my paper is the analysis of the characteristics of various tabs on the
websites, as well as the analyzing technical methods of displaying tabs on various users' computers.
In addition, users can have different browsers, different operating systems, and different preferences
in terms of their computers' settings. All these technical issues will have an impact on how the
websites will look on the user's computer. A special overview is made for the correlation between
web tabs and all the other graphic elements in the web pages from point of view of a visual harmony
of the websites. Additionally, here I give overall directions for using tabs when designing websites,
same as the description of some opinions and advice on the same topic. After that, I analyze three
problems which arise from displaying tabs in the websites on the user's computer. In this paper, I
will come across a few solutions for all of them, as well as recommendations for when to choose
which solution.
