We develop Wigner–Weyl formalism for the lattice models. For the definiteness we consider Wilson fermions in the presence of U(1) gauge field. The given technique reduces calculation of the two point ...fermionic Green function to solution of the Groenewold equation. It relates Wigner transformation of the Green function with the Weyl symbol QW of Wilson Dirac operator. We derive the simple expression for QW in the presence of varying external U(1) gauge field. Next, we solve the Groenewold equation to all orders in powers of the derivatives of QW. Thus the given technique allows to calculate the fermion propagator in the lattice model with Wilson fermions in the presence of arbitrary background electromagnetic field. The generalization of this method to the other lattice models is straightforward.
We emphasize that the results of the paper are valid if the external electromagnetic field is slowly varying (i.e. if its variation on the distance of the order of lattice spacing may be neglected).
PV panels application for water boilers Kiseleva, S; Suleymanov, M; Tarasenko, A
Journal of physics. Conference series,
06/2021, Letnik:
1960, Številka:
1
Journal Article
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Abstract
PV panels price decrease with average efficiency growth is a stable trend for modern solar energy technologies. In these conditions several companies proposed control systems for solar water ...heating, substituting solar collectors by PV panels. Advantages and disadvantages for such scheme application in Russian conditions are discussed in this paper. Results of PV water heater experimental testing in Moscow climate conditions and numerical simulation of collector versus PV panels in several Russian region are also given, as the development of earlier economic estimations. Both maximum power point tracking (MPPT) PV array control scheme and array with constant load discharge have been tested. MPPT revealed better efficiency, but special controller without battery application is needed.
The proposed economy is green due to the fact that, according to the authors, it is based on resource and energy conservation and energy efficiency, rational use of natural resources, as well as the ...disposal of man-made and household waste. Thus, with the energy saving potential in Russia of 40%, respectively, less land will be used for the extraction of fossil hydrocarbons, the area of pollution of adjacent areas during transportation will be reduced, and territories will also be freed up due to the processing of industrial waste and solid waste. All of these measures will help conserve the land and its overlying green spaces. As a result of the unprecedented economic growth of recent decades due to the anthropogenic factor - deforestation, the construction of mines, mines and oil wells, the unprecedented growth of cities, the almost uncontrolled burning of fuel, the expansion of areas occupied by industrial and domestic waste, the useful green surface of the planet (forests, farmland, parks, gardens, swamps) has been significantly reduced. That is, there is a growing imbalance of natural and physical capital. And the green color is a kind of indicator of this disharmony (balance) on the planet, which occurs due to human activity. Therefore, the new economic model should be energy efficient, low carbon, innovative, and necessarily green.
Direct marketing is one of the most significant and effective strategies in terms of attracting a target audience interested in specific services or products. The essence of this type of marketing is ...that there is no need to involve specialists in intermediary services, and it is aimed only at its target group of customers. In the implementation of direct marketing, special attention is paid to the marketing information system and marketing research. It is appropriate to note that marketing, as an economic and social category, develops on the basis of continuous changes in technology, supply and demand, which predetermines the adaptability, and not at all the sustainability of the new marketing concept. A marketing information system involves the systematic collection, analysis, interpretation, and communication of market information within an organization. It collects data from both internal and external sources of the organization. All important marketing activities such as price, new product development, packaging, distribution, promotion, media, etc. depends on the information provided by that system. The availability of quality information helps organizations make more informed market decisions. Wrong decisions regarding market operations will have a negative impact on the business and hinder its survival.
The
distributions of the
K
0
- and ϕ-mesons produced in the
collisions at
TeV have been analyzed by fitting them using the exponential function. It was observed that the distributions contain several
...regions similar to the cases with the charged particles,
-and η-mesons produced in the same events. These regions could be characterized using three variables: the length of the region
and free fitting parameters
and
. It was observed that the values of the parameters as a function of energy grouped around certain lines and there are jump-like changes. These observations together with the effect of existing the several
regions can say on discrete energy dependencies for the
,
and
. The lengths of the regions increase with the mass of the particles. This increase gets stronger with energy. The mass dependencies of the parameters
and
show a regime change at a mass
. According to the phenomenology of string theory, these results could be explained by two processes occurring simultaneously: string hadronization and string breaking. In the experiment we can only measure the spectrum of the hadronized particles, since we cannot access the spectrum of the strings themselves. The string breaking effect could be a signal of string formations and the reason behind the observation of several
regions and the jump-like changes for the characteristics of the regions.
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