652 research outputs found
Early-Stage Evolution of the EPR Spectrum of Crystalline Sucrose at Room Temperature after High-Dose X Irradiation
Variations in the squamous part of the occipital bone in medieval and contemporary cranial series from Bulgaria
The squamous part of the occipital bone is a place of many different variations. They are a result of faulty ossification in the occipital squama or due to the presence of sutural bones in the lambda region. As their differentiation is intricate because of the various criteria used, the issue of their recognition in the adult skull still remains difficult even though they can be clearly distinguished at a younger age. The aim of the present study was to compare the frequency of interparietal, preinterparietal and sutural bones in the lambda region in medieval male and female cranial series as well as between medieval and contemporary male series from Bulgaria. We also discuss the development of the occipital squama in order to set clearer criteria for further differentiation of such variations in the adult skull. In the reviewed 3 cranial series, the variations in the squamous portion of the occipital bone were observed with a low frequency. The incidence of preinterparietal bones was more common than the interparietal ones. The sutural bones in the lambda region were numerous in the series. No statistically significant sex or intergroup differences were established. So even if these anatomical variations are relatively rare, the understanding of them is of significance for many disciplines like anthropology, comparative and developmental anatomy, clinical and forensic medicine.
Precision Measurement of 11Li moments: Influence of Halo Neutrons on the 9Li Core
The electric quadrupole moment and the magnetic moment of the 11Li halo
nucleus have been measured with more than an order of magnitude higher
precision than before, |Q| = 33.3(5)mb and mu=3.6712(3)mu_N, revealing a
8.8(1.5)% increase of the quadrupole moment relative to that of 9Li. This
result is compared to various models that aim at describing the halo
properties. In the shell model an increased quadrupole moment points to a
significant occupation of the 1d orbits, whereas in a simple halo picture this
can be explained by relating the quadrupole moments of the proton distribution
to the charge radii. Advanced models so far fail to reproduce simultaneously
the trends observed in the radii and quadrupole moments of the lithium
isotopes.Comment: 4 pages, 4 figures, 1 tabl
Juvenile Nasopharyngeal Angiofibroma – Characteristics, Diagnosis and Treatment
Ювенилният назофарингеален ангиофибром е рядък съдов тумор, срещащ се с честота под 0,5% от всички тумори на главата и шията. Въпреки че е хистологично бенигнен, той притежава локална инвазивност, подобно на злокачествените неоплазми. Лечението до ден-днешен е сериозно предизвикателство, криещо множество рискове от тежки, понякога животозастрашаващи усложнения.Juvenile nasopharyngeal angiofibroma is a rare high vascular tumor with a frequency of less than 0,5% of all head and neck tumors. Although histologicaly benign, it possess invasiveness similar to malignant neoplasms. The treatment is still a challenge with risk of sometimes lifethreatening complications
Neutron stars in Gauss-Bonnet gravity -- nonlinear scalarization and gravitational phase transitions
It was recently discovered that scalarized neutron stars in scalar-tensor
theories can undergo a gravitational phase transition to a non-scalarized (GR)
state. Surprisingly, even though the driving mechanism is totally different,
the process resembles closely the first-order matter phase transition from
confined nuclear matter to deconfined quark matter in neutron star cores. The
studies until now were limited, though, to only one theory of gravity and a
limited range of parameters. With the present paper, we aim at demonstrating
that gravitational phase transitions are more common than expected. More
specifically, we show that the phenomenon of nonlinear scalarization is present
for neutron stars in Gauss-Bonnet gravity leading to the possibility of
gravitational phase transition. Moreover, it can be observed for a wide range
of parameters so no fine-tuning is needed. This solidifies the conjecture that
gravitational phase transitions are an important phenomenon for compact objects
and their astrophysical implications deserve an in-depth study.Comment: 16 pages, 5 figure
Spectroscopic distinction between the normal state pseudogap and the superconducting gap of cuprate high T_{c} superconductors
We report on broad-band infrared ellipsometry measurements of the c-axis
conductivity of underdoped RBa_{2}Cu_{3}O_{7-d} (R=Y, Nd, and La) single
crystals. Our data provide a detailed account of the spectral weight (SW)
redistributions due to the normal state pseudogap (PG) and the superconducting
(SC) gap. They show that these phenomena involve different energy scales,
exhibit distinct doping dependencies and thus are likely of different origin.
In particular, the SW redistribution in the PG state closely resembles the one
of a conventional charge- or spin density wave (CDW or SDW) system.Comment: 4 pages, 4 figure
Early-Stage Evolution of the EPR Spectrum of Crystalline Sucrose at Room Temperature after High-Dose X Irradiation
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