918 research outputs found
Prediction of the bending behavior after pre-strain of an aluminum alloy
The present work is focused on the modeling of sheet metal mechanical behavior up to rupture, including anisotropy and hardening. The mechanical behavior of an AA6016 alloy was characterized at room temperature in tension, simple shear and hydraulic bulging. The initial anisotropy was described with the Yld2004-18p yield criterion coupled to a mixed hardening law. Concerning rupture, an uncoupled phenomenological criterion of Mohr-Coulomb type will be used. For the material parameter identification, an inverse methodology was used with the objective of reducing the gap between experimental and numerical data. Finally, validation of the results was performed on bending tests with different amplitudes of tension pre-strain in order to reach or not rupture in the bent area
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Bremsstrahlung Versus Monoenergetic Photon Dose and Photonuclear Stimulation Comparisons at Long Standoff Distances
Energetic photon sources with energies greater than 6 MeV continue to be recognized as viable source for various types of inspection applications, especially those related to nuclear and/or explosive material detection. These energetic photons can be produced as a continuum of energies (i.e., bremsstrahlung distribution) or as a set of one or more discrete photon energies (i.e., monoenergetic distribution). This paper will provide a follow-on extension of the photon dose comparison presented at the 9th International Conference on Applications of Nuclear Techniques (June 2008). The latter paper showed the comparative advantages and disadvantages of the photon doses provided by these two energetic interrogation sources and highlighted the higher energy advantage of the bremsstrahlung source, especially at long standoff distances (i.e., distance from source to the inspected object). Specifically, this paper will pursue this higher energy photon inspection advantage (up to 100 MeV) by providing dose and stimulated photonuclear interaction predictions for air and an infinitely dilute interrogated material (used for comparative interaction rate assessments since it excludes material self-shielding) as the interrogation object positioned forward on the inspection beam axis at increasing standoff distances. In addition to the direct energetic photon-induced stimulation, the predictions will identify the importance of any secondary downscattered/attenuated source-term effects arising from the photon transport in the intervening atmosphere. *Supported in part by the Defense Threat Reduction Agency and Department of Energy (DOE) Idaho Operations Office under Contract Number DE-AC07-05ID14517
Algorithmic Formulations of Evolutionary Anisotropic Plasticity Models Based on Non-Associated Flow Rule
Reunion of random walkers with a long range interaction: applications to polymers and quantum mechanics
We use renormalization group to calculate the reunion and survival exponents
of a set of random walkers interacting with a long range and a short
range interaction. These exponents are used to study the binding-unbinding
transition of polymers and the behavior of several quantum problems.Comment: Revtex 3.1, 9 pages (two-column format), 3 figures. Published version
(PRE 63, 051103 (2001)). Reference corrections incorporated (PRE 64, 059902
(2001) (E
Testing scuffing resistance of materials for marine 2-stroke engines β Difficulties with lab scale testing of a complex phenomenon
The Parallel Magnetoconductance of Interacting Electrons in a Two Dimensional Disordered System
The transport properties of interacting electrons for which the spin degree
of freedom is taken into account are numerically studied for small two
dimensional diffusive clusters. On-site electron-electron interactions tend to
delocalize the electrons, while long-range interactions enhance localization.
On careful examination of the transport properties, we reach the conclusion
that it does not show a two dimensional metal insulator transition driven by
interactions. A parallel magnetic field leads to enhanced resistivity, which
saturates once the electrons become fully spin polarized. The strength of the
magnetic field for which the resistivity saturates decreases as electron
density goes down. Thus, the numerical calculations capture some of the
features seen in recent experimental measurements of parallel
magnetoconductance.Comment: 10 pages, 6 figure
Expression profiling of cyclin B1 and D1 in cervical carcinoma
Aim: Cyclins are a family of regulatory proteins that play a key role in controlling the cell cycle. Abnormalities of cell cycle regulators, including cyclins and cyclin dependent kinases, have been reported in various malignant tumors. This study was undertaken to quantitatively detect cyclin B1 and D1 in cervical cancer. Methods: A quantitative real-time reverse transcription polymerase chain reaction and Western blot assay were used to analyze the expression of cyclin B1/D1 mRNA and proteins, respectively, in fresh invasive cervical cancer (n = 41) and normal cervical tissues (n = 10). Results: There was significantly greater cyclin B1 expression in invasive cervical cancer than in normal cervical tissue (P = 0.019). However, cyclin D1 expression was not significantly different. A Western blot assay yielded similar results. Conclusion: Our results were consistent with the concept that up-regulation of cyclin B1 expression occurred in cervical cancer and an aberrant expression of cyclin B1 might play an important role in cervical carcinogenesis.Π¦Π΅Π»Ρ: ΡΠΈΠΊΠ»ΠΈΠ½Ρ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»ΡΡΡ ΡΠΎΠ±ΠΎΠΉ ΡΠ΅ΠΌΠ΅ΠΉΡΡΠ²ΠΎ ΡΠ΅Π³ΡΠ»ΡΡΠΎΡΠ½ΡΡ
Π±Π΅Π»ΠΊΠΎΠ², ΠΊΠΎΠ½ΡΡΠΎΠ»ΠΈΡΡΡΡΠΈΡ
ΠΊΠ»Π΅ΡΠΎΡΠ½ΡΠΉ ΡΠΈΠΊΠ». ΠΠ°Π»ΠΈΡΠΈΠ΅
ΡΡΠ½ΠΊΡΠΈΠΎΠ½Π°Π»ΡΠ½ΡΡ
ΠΈ ΡΡΡΡΠΊΡΡΡΠ½ΡΡ
Π½Π°ΡΡΡΠ΅Π½ΠΈΠΉ ΡΠ΅Π³ΡΠ»ΡΡΠΎΡΠΎΠ² ΠΊΠ»Π΅ΡΠΎΡΠ½ΠΎΠ³ΠΎ ΡΠΈΠΊΠ»Π° (ΡΠΈΠΊΠ»ΠΈΠ½ΠΎΠ² ΠΈ ΡΠΈΠΊΠ»ΠΈΠ½Π·Π°Π²ΠΈΡΠΈΠΌΡΡ
ΠΊΠΈΠ½Π°Π·) Π±ΡΠ»ΠΎ
ΠΎΡΠΌΠ΅ΡΠ΅Π½ΠΎ Π² ΠΊΠ»Π΅ΡΠΊΠ°Ρ
ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
Π·Π»ΠΎΠΊΠ°ΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΡ
Π½ΠΎΠ²ΠΎΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΠΉ. Π¦Π΅Π»ΡΡ Π΄Π°Π½Π½ΠΎΠ³ΠΎ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ Π±ΡΠ»ΠΎ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠ΅
ΠΊΠΎΠ»ΠΈΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎΠ³ΠΎ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΡΠΈΠΊΠ»ΠΈΠ½ΠΎΠ² B1 ΠΈ D1 Π² ΠΊΠ»Π΅ΡΠΊΠ°Ρ
ΡΠ°ΠΊΠ° ΡΠ΅ΠΉΠΊΠΈ ΠΌΠ°ΡΠΊΠΈ. ΠΠ΅ΡΠΎΠ΄Ρ: ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ ΡΡΠΎΠ²Π½Ρ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ
ΡΠΈΠΊΠ»ΠΈΠ½ΠΎΠ² B1/D1 (mRNA ΠΈ Π±Π΅Π»ΠΊΠΎΠ² ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²Π΅Π½Π½ΠΎ) Π² ΡΠ²Π΅ΠΆΠ΅ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ
ΠΊΠ»Π΅ΡΠΊΠ°Ρ
ΠΈΠ½Π²Π°Π·ΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΠ°ΠΊΠ° ΡΠ΅ΠΉΠΊΠΈ ΠΌΠ°ΡΠΊΠΈ (n = 41) ΠΈ
Π½ΠΎΡΠΌΠ°Π»ΡΠ½ΠΎΠΉ ΡΠΊΠ°Π½ΠΈ ΡΠ΅ΠΉΠΊΠΈ ΠΌΠ°ΡΠΊΠΈ (n = 10) ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΈ ΠΌΠ΅ΡΠΎΠ΄Π°ΠΌΠΈ RT-PCR Π² ΡΠ΅ΠΆΠΈΠΌΠ΅ ΡΠ΅Π°Π»ΡΠ½ΠΎΠ³ΠΎ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ ΠΈ ΠΠ΅ΡΡΠ΅ΡΠ½-Π±Π»ΠΎΡ Π°Π½Π°Π»ΠΈΠ·Π°.
Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ: ΠΎΡΠΌΠ΅ΡΠ΅Π½ Π±ΠΎΠ»Π΅Π΅ Π²ΡΡΠΎΠΊΠΈΠΉ ΡΡΠΎΠ²Π΅Π½Ρ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ Π³Π΅Π½Π° ΡΠΈΠΊΠ»ΠΈΠ½Π° Π1 Π² ΠΊΠ»Π΅ΡΠΊΠ°Ρ
ΠΈΠ½Π²Π°Π·ΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΠ°ΠΊΠ° ΡΠ΅ΠΉΠΊΠΈ ΠΌΠ°ΡΠΊΠΈ, ΡΠ΅ΠΌ Π²
ΠΊΠ»Π΅ΡΠΊΠ°Ρ
Π½ΠΎΡΠΌΠ°Π»ΡΠ½ΠΎΠΉ ΡΠΊΠ°Π½ΠΈ (P = 0,019). ΠΠ΅ Π²ΡΡΠ²Π»Π΅Π½Ρ Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΡΠ΅ ΡΠ°Π·Π»ΠΈΡΠΈΡ Π² ΡΡΠΎΠ²Π½Π΅ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ Π³Π΅Π½Π° ΡΠΈΠΊΠ»ΠΈΠ½Π° D1. ΠΡΠΈ
ΠΠ΅ΡΡΠ΅ΡΠ½-Π±Π»ΠΎΡ Π°Π½Π°Π»ΠΈΠ·Π΅ ΠΏΠΎΠ»ΡΡΠ΅Π½Ρ Π°Π½Π°Π»ΠΎΠ³ΠΈΡΠ½ΡΠ΅ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ. ΠΡΠ²ΠΎΠ΄Ρ: ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠΆΠ΄Π°ΡΡ ΠΊΠΎΠ½ΡΠ΅ΠΏΡΠΈΡ
ΠΎΠ± Π°ΠΊΡΠΈΠ²Π°ΡΠΈΠΈ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ ΡΠΈΠΊΠ»ΠΈΠ½Π° Π1 ΠΏΡΠΈ ΡΠ°ΠΊΠ΅ ΡΠ΅ΠΉΠΊΠΈ ΠΌΠ°ΡΠΊΠΈ. ΠΠ±Π΅ΡΡΠ°Π½ΡΠ½Π°Ρ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΡ ΡΠΈΠΊΠ»ΠΈΠ½Π° Π1 ΠΌΠΎΠΆΠ΅Ρ ΠΈΠ³ΡΠ°ΡΡ Π²Π°ΠΆΠ½ΡΡ
ΡΠΎΠ»Ρ ΠΏΡΠΈ Π·Π»ΠΎΠΊΠ°ΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎΠΉ ΡΡΠ°Π½ΡΡΠΎΡΠΌΠ°ΡΠΈΠΈ ΡΠΏΠΈΡΠ΅Π»ΠΈΡ ΡΠ΅ΠΉΠΊΠΈ ΠΌΠ°ΡΠΊΠΈ
Synchronization and resonance in a driven system of coupled oscillators
We study the noise effects in a driven system of globally coupled
oscillators, with particular attention to the interplay between driving and
noise. The self-consistency equation for the order parameter, which measures
the collective synchronization of the system, is derived; it is found that the
total order parameter decreases monotonically with noise, indicating overall
suppression of synchronization. Still, for large coupling strengths, there
exists an optimal noise level at which the periodic (ac) component of the order
parameter reaches its maximum. The response of the phase velocity is also
examined and found to display resonance behavior.Comment: 17 pages, 3 figure
Surface finishing of intricate metal mould structures by large-area electron beam irradiation
The advancement of polymer moulding tools is increasingly focused on imparting not only form but also surface texture for functionality to the surfaces of parts that are created. Furthermore, the increasing demand for inexpensive and higher quality micro-components means that tools for replication processes must take advantage of advanced manufacturing techniques. Tools created by processes such as micro-investment casting, as in this case, may often suffer from excessive surface roughness, malformed edges and general deformation. This results in higher de-moulding forces and a reduction in fidelity of moulded parts to design intent. In this study, large-area electron beam irradiation (EB) is shown to be an effective technique for improving these metrics. For the first time, large population, high aspect ratio micro-features are subject to this process and the mechanisms of smoothing and key enhancement phenomena are demonstrated. The possibility of including EB irradiation in an integrated process chain for arriving at net shape is also discussed.
Surfaces of protruding features are shown to have surface roughness reduced significantly from 126 to 22 nm Ra value, with bottom substrate also similarly improving from 150 to 27 nm Ra. Bottoms of recessed features are also observed to have much improved surface finishes. βDomingβ of tops of column features is also demonstrated, further enhancing form. These features would be far too fragile to be polished by any other mechanical method
Evolution of the number of accreting white dwarfs with shell nuclear burning and of occurrence rate of SN Ia
We analyze temporal evolution of the number of accreting white dwarfs with
shell hydrogen burning in semidetached and detached binaries. We consider a
stellar system in which star formation lasts for 10 Gyr with a constant rate,
as well as a system in which the same amount of stars is formed in a single
burst lasting for 1 Gyr. Evolution of the number of white dwarfs is confronted
to the evolution of occurrence rate of events that usually are identified with
SN Ia or accretion-induced collapses, i.e. with accumulation of Chandrasekhar
mass by a white dwarf or a merger of a pair of CO white dwarfs with total mass
not lower than the Chandrasekhar one. In the systems with a burst of star
formation, at 10 Gyr observed supersoft X-ray sources, most probably, are
not precursors of SN Ia. The same is true for an overwhelming majority of the
sources in the systems with constant star formation rate. In the systems of
both kinds mergers of white dwarfs is the dominant SN Ia scenario. In symbiotic
binaries, accreting CO-dwarfs do not accumulate enough mass for SN Ia
explosion, while ONeMg-dwarfs finish their evolution by an accretion-induced
collapse with formation of a neutron star.Comment: 11 pages, 2 figures, accepted by Astronomy Letter
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