5,973 research outputs found
Огляд ринку сонячної енергетики України: стан та комерційні перспективи
Today, solar energy is called the energy of the future, and many companies make significant investments in the construction of such power plants. The article provides an overview of the commercial perspectives of this market, determines the size of investments and the return on the project. Modern solar panels are able to operate without additional investments for decades and, from the point of view of the authors, in the long term the electricity generated in this way will not only cost-effective, and extremely profitable. The global situation in the energy market and in the field of renewable energy, in particular, is considered. The reasons that triggered the development of renewable energy sources, the key of which are the dangers of nuclear energy and environmental pollution, are explained. Along with this, we consider the structure of the market of renewable energy sources in Ukraine, where the geographic location is favorable for the implementation of solar energy projects. The climate of Ukraine is characterized by a large number of sunny days: in terms of insolation, Ukraine is significantly superior to European leaders in solar energy. This basic factor allows us to talk about the commercial perspectives of solar power generation projects implemented in Ukraine. Against the background of these perspectives is considered the structure of the energy market in Ukraine and the investment attraction of renewable energy projects. Market trends in the development of the solar energy market were discussed, which are expected to contribute to the development of new market niches, such as after-sales services, as well as the transformation of existing business models against the backdrop of the introduction of new facilities.Сьогодні багато хто називає сонячну енергію енергією майбутнього, і багато компаній вкладають значні інвестиції в будівництво таких електростанцій. У статті наведено огляд комерційних перспектив цього ринку, визначені розміри інвестицій і окупність проекту. Сучасні сонячні батареї в змозі працювати без додаткових капіталовкладень десятки років і, з точки зору авторів, в довгостроковій перспективі електроенергія, згенерована таким чином, стане не просто рентабельною, а надприбутковою. У статті розглянута глобальна ситуація в сфері ринку енергетики і в сфері відновлюваних джерел енергії, зокрема. Пояснені причини, які послужили поштовхом у розвитку відновлюваних джерел енергії, ключовими з яких є небезпека атомної енергетики і забруднення навколишнього середовища. На ряду з зазначеним, розглянута структура ринку відновлюваних джерел енергії на Україні, географічне розташування якої сприятливо для реалізації проектів сонячної енергетики. Для клімату України характерна велика кількість сонячних днів: за ступенем інсоляції Україна значно перевершує європейських лідерів в сонячній енергетиці. Зазначене є базовим фактором, що дозволяє говорити про комерційні перспективи проектів сонячної електрогенерації, що реалізуються в Україні. На тлі зазначених перспектив розглянута структура енергетичного ринку на Україні і інвестиційна привабливість проектів відновлюваної енергетики. Обговорено ринкові тенденції розвитку ринку сонячної енергетики, які, як очікується, на тлі введення нових об'єктів сприятимуть розвитку нових ринкових ніш, таких як сервісне обслуговування, а також трансформації існуючих бізнес-моделей
Quantum Spectra and Wave Functions in Terms of Periodic Orbits for Weakly Chaotic Systems
Special quantum states exist which are quasiclassical quantizations of
regions of phase space that are weakly chaotic. In a weakly chaotic region, the
orbits are quite regular and remain in the region for some time before escaping
and manifesting possible chaotic behavior. Such phase space regions are
characterized as being close to periodic orbits of an integrable reference
system. The states are often rather striking, and can be concentrated in
spatial regions. This leads to possible phenomena. We review some methods we
have introduced to characterize such regions and find analytic formulas for the
special states and their energies.Comment: 9 pages, 8 eps figure
Proximity Effect Enhancement Induced by Roughness of SN Interface
Critical temperature reduction is considered for a thin film of
a layered superconductor (S) with a rough surface covered by a thick layer of a
normal metal (N). The roughness of the SN interface increases the penetration
of electrons from the normal metal into the superconductor and leads to an
enhancement of the proximity effect. The value of induced by the
roughness of the SN interface can be much higher than for a film
with a plain surface for an extremely anisotropic layered superconductor with
the coherence lengths .Comment: 2 page
Experimental evidence of ageing and slow restoration of the weak-contact configuration in tilted 3D granular packings
Granular packings slowly driven towards their instability threshold are
studied using a digital imaging technique as well as a nonlinear acoustic
method. The former method allows us to study grain rearrangements on the
surface during the tilting and the latter enables to selectively probe the
modifications of the weak-contact fraction in the material bulk. Gradual ageing
of both the surface activity and the weak-contact reconfigurations is observed
as a result of repeated tilt cycles up to a given angle smaller than the angle
of avalanche. For an aged configuration reached after several consecutive tilt
cycles, abrupt resumption of the on-surface activity and of the weak-contact
rearrangements occurs when the packing is subsequently inclined beyond the
previous maximal tilting angle. This behavior is compared with literature
results from numerical simulations of inclined 2D packings. It is also found
that the aged weak-contact configurations exhibit spontaneous restoration
towards the initial state if the packing remains at rest for tens of minutes.
When the packing is titled forth and back between zero and near-critical
angles, instead of ageing, the weak-contact configuration exhibits "internal
weak-contact avalanches" in the vicinity of both the near-critical and zero
angles. By contrast, the stronger-contact skeleton remains stable
One-dimensional conduction in Charge-Density Wave nanowires
We report a systematic study of the transport properties of coupled
one-dimensional metallic chains as a function of the number of parallel chains.
When the number of parallel chains is less than 2000, the transport properties
show power-law behavior on temperature and voltage, characteristic for
one-dimensional systems.Comment: 4 pages, 5 figures, submitted to Phys. Rev. Let
Nonlinear resonance in a three-terminal carbon nanotube resonator
The RF-response of a three-terminal carbon nanotube resonator coupled to
RF-transmission lines is studied by means of perturbation theory and direct
numerical integration. We find three distinct oscillatory regimes, including
one regime capable of exhibiting very large hysteresis loops in the frequency
response. Considering a purely capacitive transduction, we derive a set of
algebraic equations which can be used to find the output power (S-parameters)
for a device connected to transmission lines with characteristic impedance
.Comment: 16 pages, 8 figure
Implications of a J^PC exotic
Recent experimental data from BNL on the isovector J^PC =1^-+ exotic at 1.6
GeV in \rho\pi indicate the existence of a non-quarkonium state consistent with
lattice gauge theory predictions. We discuss how further experiments can
strengthen this conclusion. We show that the \rho\pi, \eta'\pi and \eta\pi
couplings of this state qualitatively support the hypothesis that it is a
hybrid meson, although other interpretations cannot be eliminated.Comment: 10 pages, LaTeX, minor numerical correction
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