1,174 research outputs found
MARVEL analysis of the measured high-resolution rovibronic spectra of the calcium monohydroxide radical (CaOH)
The calcium monohydroxide radical (CaOH) is an important astrophysical
molecule relevant to cool stars and rocky exoplanets, amongst other
astronomical environments. Here, we present a consistent set of highly accurate
rovibronic (rotation-vibration-electronic) energy levels for the five lowest
electronic states (\tilde{X}\,^2\Sigma^+, \tilde{A}\,^2\Pi,
\tilde{B}\,^2\Sigma^+, \tilde{C}\,^2\Delta, \tilde{D}\,^2\Sigma^+) of
CaOH. A comprehensive analysis of the published spectroscopic literature on
this system has allowed 1955 energy levels to be determined from 3204
rovibronic experimental transitions, all with unique quantum number labelling
and measurement uncertainties. The dataset covers rotational excitation up to
for molecular states below 29\,000~cm. The analysis was
performed using the MARVEL algorithm, which is a robust procedure based on the
theory of spectroscopic networks. The dataset provided will significantly aid
future interstellar, circumstellar and atmospheric detections of CaOH, as well
as assisting in the design of efficient laser cooling schemes in ultracold
molecule research and precision tests of fundamental physics
Flux Penetration in Superconducting Strip with Edge-Indentation
The flux penetration near a semicircular indentation at the edge of a thin
superconducting strip placed in a transverse magnetic field is investigated.
The flux front distortion due to the indentation is calculated numerically by
solving the Maxwell equations with a highly nonlinear law. We find that
the excess penetration, , can be significantly ( 50%) larger than
the indentation radius , in contrast to a bulk supercondutor in the
critical state where . It is also shown that the flux creep tends
to smoothen the flux front, i.e. reduce . The results are in very good
agreement with magneto-optical studies of flux penetration into an
YBaCuO film having an edge defect.Comment: 5 pages, 7 figure
Method of restoring pivot connections cast iron bushings of heat engine with external heat supply
The article presents the results of studies aimed at developing a method of restoring cast iron bushings for pivot connections of a heat engine with external heat supply. The methods of computer modeling the stress-strain state of the pivot connections are used. To carry out computer modeling, the ANSYS program has been used, which allows simulating the stress-strain state of the kinetic pair of the pivot connection of the crank mechanism of engines with external heat supply and excluding cumbersome field tests of experimental samples. The dependence of stresses on the contact surface of the bushing on the depth of the boring in relation to its total length has experimentally been established
Method of restoring pivot connections cast iron bushings of heat engine with external heat supply
The article presents the results of studies aimed at developing a method of restoring cast iron bushings for pivot connections of a heat engine with external heat supply. The methods of computer modeling the stress-strain state of the pivot connections are used. To carry out computer modeling, the ANSYS program has been used, which allows simulating the stress-strain state of the kinetic pair of the pivot connection of the crank mechanism of engines with external heat supply and excluding cumbersome field tests of experimental samples. The dependence of stresses on the contact surface of the bushing on the depth of the boring in relation to its total length has experimentally been established
Strengthening elements to increase fatigue strength of mine hoisting machine steel structures
The article deals with the issues of reliable operation of metal structures of mine hoisting machines. A method has been developed that makes it possible to increase the brake device steel beam structures strength, which will further prevent the formation and growth of cracks in the body of the metal structure. It is proposed to strengthen the «weak points» in the structure to increase strength and resistance to fatigue failure with the complete rejection of using expensive high-strength alloys. To study the stress-strain state and fatigue failure of steel structures, the method of computer simulation was used. The article presents the results of studying metal structures of mine hoisting machines by non-destructive testing methods; the percentage of various damages is determined. The article discusses a method for combating fatigue failure of steel structures through the use of elements that strengthen the structure in the places of its fatigue failure
Strengthening elements to increase fatigue strength of mine hoisting machine steel structures
The article deals with the issues of reliable operation of metal structures of mine hoisting machines. A method has been developed that makes it possible to increase the brake device steel beam structures strength, which will further prevent the formation and growth of cracks in the body of the metal structure. It is proposed to strengthen the «weak points» in the structure to increase strength and resistance to fatigue failure with the complete rejection of using expensive high-strength alloys. To study the stress-strain state and fatigue failure of steel structures, the method of computer simulation was used. The article presents the results of studying metal structures of mine hoisting machines by non-destructive testing methods; the percentage of various damages is determined. The article discusses a method for combating fatigue failure of steel structures through the use of elements that strengthen the structure in the places of its fatigue failure
Roe deer (Capreolus capreolus) are a novel potential reservoir for human visceral leishmaniasis in the Emilia-Romagna region of northeastern Italy
Leishmaniasis is a complex human disease caused by intracellular parasites of the genus Leishmania, predominantly transmitted by the bite of sand flies. In Italy, leishmaniasis is caused exclusively by Leishmania infantum, responsible for the human and canine visceral leishmaniases (HVL and CVL, respectively). Within the Emilia-Romagna region, two different foci are active in the municipalities of Pianoro and Valsamoggia (both in the province of Bologna). Recent molecular studies indicated that L. infantum strains circulating in dogs and humans are different, suggesting that there is an animal reservoir other than dogs for human visceral leishmaniasis in the Emilia-Romagna region. In this work, we analyzed specimens from wild animals collected during hunts or surveillance of regional parks near active foci of human visceral leishmaniasis for L. infantum infection in the province of Bologna. Out of 70 individuals analyzed, 17 (24%) were positive for L. infantum. The infection prevalence in hedgehogs (Erinaceus europaeus), roe deer (Capreolus capreolus), badgers (Meles meles), and bank voles (Myodes glareolus) was 80, 33, 25, and 11%, respectively. To distinguish the two strains of L. infantum we have developed a nested PCR protocol optimized for animal tissues. Our results demonstrated that most (over 90%) of L. infantum infections in roe deer were due to the strain circulating in humans in the Emilia-Romagna region
Interaction between superconducting vortices and Bloch wall in ferrite garnet film
Interaction between a Bloch wall in a ferrite-garnet film and a vortex in a
superconductor is analyzed in the London approximation. Equilibrium
distribution of vortices formed around the Bloch wall is calculated. The
results agree quantitatively with magneto-optical experiment where an in-plane
magnetized ferrite-garnet film placed on top of NbSe2 superconductor allows
observation of individual vortices. In particular, our model can reproduce a
counter-intuitive attraction observed between vortices and a Bloch wall having
the opposite polarity. It is explained by magnetic charges appearing due to
discontinuity of the in-plane magnetization across the wall.Comment: 4 pages, 5 figure
Quasi-one-dimensional intermittent flux behavior in superconducting films
Intermittent filamentary dynamics of the vortex matter in superconductors is found in films of YBa2Cu3O7-ÎŽ deposited on tilted substrates. Deposition of this material on such substrates creates parallel channels of easy flux penetration when a magnetic field is applied perpendicular to the film. As the applied field is gradually increased, magneto-optical imaging reveals that flux penetrates via numerous quasi-one-dimensional jumps. The distribution of flux avalanche sizes follows a power law, and data collapse is obtained by finite-size scaling, with the depth of the flux front used as crossover length. The intermittent behavior shows no threshold value in the applied field, in contrast to conventional flux jumping. The results strongly suggest that the quasi-one-dimensional flux jumps are of a different nature than the thermomagnetic dendritic (branching) avalanches that are commonly found in superconducting films
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