1,249 research outputs found
Parameter selection for the supply system in a Pilger mill
The braking chamber in the supply system of a Pilger pipe mill is modernized. The influence of constant and variable parameters of the supply system on braking is studied. © 2013 Allerton Press, Inc
Rapid evolution of hybrid breakdown following recent divergence with gene flow in Senecio species on Mount Etna, Sicily
How do nascent species evolve reproductive isolation during speciation with on-going gene flow? How do hybrid lineages become stabilised hybrid species? While commonly used genomic approaches provide an indirect way to identify species incompatibility factors, synthetic hybrids generated from interspecific crosses allow direct pinpointing of phenotypic traits involved in incompatibilities and the traits that are potentially adaptive in hybrid species. Here we report the analysis of phenotypic variation and hybrid breakdown in crosses between closely-related Senecio aethnensis and S. chrysanthemifolius, and their homoploid hybrid species, S. squalidus. The two former species represent a likely case of recent (<200 ky) speciation with gene flow driven by adaptation to contrasting conditions of high- and low-elevations on Mount Etna, Sicily. As these species form viable and fertile hybrids, it remains unclear whether they have started to evolve reproductive incompatibility. Our analysis represents the first study of phenotypic variation and hybrid breakdown involving multiple Senecio hybrid families. It revealed wide range of variation in multiple traits, including the traits previously unrecorded in synthetic hybrids. Leaf shape, highly distinct between S. aethnensis and S. chrysanthemifolius, was extremely variable in F2 hybrids, but more consistent in S. squalidus. Our study demonstrates that interspecific incompatibilities can evolve rapidly despite on-going gene flow between the species. Further work is necessary to understand the genetic bases of these incompatibilities and their role in speciation with gene flow.info:eu-repo/semantics/publishedVersio
Laser acceleration of ion beams
We consider methods of charged particle acceleration by means of
high-intensity lasers. As an application we discuss a laser booster for heavy
ion beams provided, e.g. by the Dubna nuclotron. Simple estimates show that a
cascade of crossed laser beams would be necessary to provide additional
acceleration to gold ions of the order of GeV/nucleon.Comment: 4 pages, 4 figures, Talk at the Helmholtz International Summer School
"Dense Matter in heavy Ion Collisions and Astrophysics", August 21 -
September 1, 2006, JINR Dubna, Russia; v2, misprints correcte
Wireless digital traffic signs of the future
[EN] Traffic signs have come a long way since the first automobile was invented. They have long served the purpose of warning and guiding drivers and also enforcing the traffic laws governing speed, parking, turns, and stopping. In this study, the authors discuss the issues and challenges facing current traffic signs, and how it will evolve into a next-generation traffic sign architecture using advanced wireless communications technologies. With technological advances in the areas of wireless communications and embedded electronics and software, we foresee that, in the future, digital traffic sign posts will be capable of transmitting the traffic sign information wirelessly to road users, and this will transform our roads into intelligent roads, where signs will appear promptly and automatically on in-vehicle displays to alert the driver. There is no longer the need to watch out for traffic signs since the detection will be automatic and performed wirelessly. This transformation will lessen burden on the drivers, so that they can then focus more on the traffic ahead while driving. Also, this evolution into wireless digital sign posts will fit well with the vision of future smart cities, where smart transportation technologies will be present to transform how we drive and commute, yielding greater safety, ease, and assistance to drivers.Toh, CK.; Cano, J.; Fernandez-Laguia, C.; Manzoni, P.; Tavares De Araujo Cesariny Calafate, CM. (2019). Wireless digital traffic signs of the future. IET Networks. 8(1):74-78. https://doi.org/10.1049/iet-net.2018.5127S74788
Органические растворители и свойства прядильных растворов
The given article represents the bases of selection of solvents for polymer solutions. The results of the research indicate that the solvent is an effective instrument which allows the combination of polymers through the solutions. These solutions are employed for creating fibrous materials.В представленной работе отражены основные аспекты выбора растворителей при создании фильтрующих материалов ФП (Фильтр Петрянова®). Представлены результаты исследования, характеризующие растворитель как эффективный инструмент, позволяющий совмещать полимеры через растворы и получать прядильные растворы, используемые в ЭФВ-процессе (процессе эектроформования волокнистых материалов)
Исследование процесса электроформования смесей фторполимеров и свойств получаемых материалов
To substitute the foreign filtering membrane Millipore FSLW, which currently in use on some of Russian and Ukrainian NPP the nonwoven fibrous material, obtained by means of electrospinning from spinning solutions of mixtured fluoropolymers F-42 and SKF-26, have been produced. The influence of polymer ratio on fibrous material properties was investigated.С целью замены применяемой в настоящее время на ряде российских и украинских АЭС импортной фильтрующей мембраны Millipore FSLW был разработан отечественный нетканый волокнистый материал, полученный методом электроформования из формовочных растворов на основе смеси фторполимеров Ф-42 и СКФ-26. Исследовано влияние соотношения полимеров на свойства волокнистого материала
Spin Resolution of the Electron-Gas Correlation Energy: Positive same-spin contribution
The negative correlation energy per particle of a uniform electron gas of
density parameter and spin polarization is well known, but its
spin resolution into up-down, up-up, and down-down contributions is not.
Widely-used estimates are incorrect, and hamper the development of reliable
density functionals and pair distribution functions. For the spin resolution,
we present interpolations between high- and low-density limits that agree with
available Quantum Monte Carlo data. In the low-density limit for ,
we find that the same-spin correlation energy is unexpectedly positive, and we
explain why. We also estimate the up and down contributions to the kinetic
energy of correlation.Comment: new version, to appear in PRB Rapid Communicatio
Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jefferson Lab
This report presents a brief summary of the science opportunities and program
of a polarized medium energy electron-ion collider at Jefferson Lab and a
comprehensive description of the conceptual design of such a collider based on
the CEBAF electron accelerator facility.Comment: 160 pages, ~93 figures This work was supported by the U.S. Department
of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177,
DE-AC02-06CH11357, DE-AC05-060R23177, and DESC0005823. The U.S. Government
retains a non-exclusive, paid-up, irrevocable, world-wide license to publish
or reproduce this manuscript for U.S. Government purpose
Прогнозирование растворимости фторполимеров
The article describes different approaches towards finding solubility parameter of fluorpolymers and also provides comparative analysis of the obtained values.В статье отражены результаты работы, связанной с определением и сопоставлением значений параметра растворимости фторполимеров с использованием различных методов
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