Previous research has shown that implementing high-temperature superconducting dc power cables in electrical grids of large metropolitan areas will have major positive impacts on power system ...operation and control. Current activities in Russia comprise developing a 2.5-km high-temperature superconducting dc cable and its installation in St. Petersburg electrical grid. This work includes five major parts: installation site selection, cable calculation, development and manufacturing, cryogenic equipment development, ac/dc converter development, and testing of all dc line elements. As of today, the list of subcontractors has been approved. The purpose of this report is to summarize current results and future work.
ABSTRACT
We report the discovery of a circular mid-infrared shell around the emission-line star Wray 16-137 using archival data of the Spitzer Space Telescope. Follow-up optical spectroscopy of Wray ...16-137 with the Southern African Large Telescope revealed a rich emission spectrum typical of the classical luminous blue variables (LBVs) like P Cygni. Subsequent spectroscopic and photometric observations showed drastic changes in the spectrum and brightness during the last three years, meaning that Wray 16-137 currently undergoes an S Dor-like outburst. Namely, we found that the star has brightened by ≈1 mag in the V and Ic bands, while its spectrum became dominated by Fe ii lines. Taken together, our observations unambiguously show that Wray 16-137 is a new member of the family of Galactic bona fide LBVs.
In 2005–2014 we acquired a total of 135, 137 and 134 measurements in
B
-,
V
- and
I
c
-filters, respectively, for the 5-days Cepheid ASAS 160125-5150.3. Our observations showed variations of light ...amplitude, which allowed us to suspect the presence of the Blazhko effect. Combining our measurements with ASAS-3 data allowed us to determine the period of the Blazhko effect
P
B
l
=
1242
d
±
10
d
, and now ASAS 160125-5150.3 is the second Galactic Cepheid (after V473 Lyr) with strong Blazhko effect pulsating in the first overtone.
In 2012–2014 we acquired 1569 CCD
B
V
I
c
frames for the RR Lyrae type variable SW Dor with the 76-cm telescope of the South African Astronomical Observatory (SAAO) and 1-m telescopes of Las Cumbres ...Observatory Global Telescope network (LCOGT). Our observations showed a large scatter in the resulting phased light curve, especially near maximum brightness, which allowed us to reveal the Blazhko effect with a period of
∼
80
.
d
9
. To study the pulsation period changes, we used all the available observations including the 1299 magnitude estimates from the digitized plate library of Harvard University (the DASCH project), which allowed us to construct the
O
−
C
diagram spanning a 125-year long time interval and discover for the first time at least three abrupt changes of the pulsation period.
Results are presented from measuring nuclear modification factors
R
AA
of the π
0
, η,
K
S
, and ω mesons produced in systems of Cu + Au and U + U collisions at cms energies of
= 200 and 192 GeV, ...respectively, in the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC). The
R
AA
values are found not to depend on the type of neutral meson and to vary in the ~0.4–0.6 and ~0.2–0.3 intervals for central Cu + Au and U + U collisions, respectively. The mean
R
AA
values for different collision systems (Au + Au, Cu + Cu, Cu + Au, and U + U) are found to coincide within the measuring errors when estimated at comparable values of collision energy
, and of the number of nucleons participating in a nucleus–nucleus collision,
N
part
.
A major objective in the field of high-energy nuclear physics is to quantify and characterize the quark-gluon plasma (QGP) formed in relativistic heavy-ion collisions, representing an ideal liquid ...with partonic degrees of freedom 1-4. Due to the very short lifetime the ϕ-meson can decay in QGP, thereby providing a key information on the hot and dense medium properties created in the relativistic heavy ion collisions. In central Cu+Au collision, the smaller nucleus is fully enveloped in the larger one thus reducing the contribution of nucleon-nucleon collisions in the low-density nuclear corona region. The U+U collision system provides the largest energy density available at RHIC. Also, the uranium nucleus is highly asymmetric, which leads to different parametrizations of the U+U collision geometry. In this report we will present latest results on the ϕ-meson production in Cu+Au at S NN =200GeV and U+U collisions at S NN =192GeV using the PHENIX detector at the RHIC 5. This report presents invariant transverse momentum spectra and nuclear modification factors of ϕ-meson.
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