The interior rotation of a sample of gamma Doradus stars from ensemble modelling of their gravity mode period spacings

CONTEXT. Gamma Doradus stars (hereafter gamma Dor stars) are known to exhibit gravity- and/or gravito-intertial modes that probe the inner stellar region near the convective core boundary. The non-equidistant spacing of the pulsation periods is an observational signature of the stars' evolution and current internal structure and is heavily influenced by rotation. AIMS. We aim to constrain the near-core rotation rates for a sample of gamma Dor stars, for which we have detected period spacing patterns. METHODS. We combined the asymptotic period spacing with the traditional approximation of stellar pulsation to fit the observed period spacing patterns using chi-squared optimisation. The method was applied to the observed period spacing patterns of a sample of stars and used for ensemble modelling. RESULTS. For the majority of stars with an observed period spacing pattern we successfully determined the rotation rates and the asymptotic period spacing values, though the uncertainty margins on the latter were typically large. This also resulted directly in the identification of the modes corresponding with the detected pulsation frequencies, which for most stars were prograde dipole gravity and gravito-inertial modes. The majority of the observed retrograde modes were found to be Rossby modes. We further discuss the limitations of the method due to the neglect of the centrifugal force and the incomplete treatment of the Coriolis force. CONCLUSION. Despite its current limitations, the proposed methodology was successful to derive the rotation rates and to identify the modes from the observed period spacing patterns. It forms the first step towards detailed seismic modelling based on observed period spacing patterns of moderately to rapidly rotating gamma Dor stars.Comment: 12 pages, 15 figures, 5 tables. Accepted for publication in Astronomy & Astrophysic

Least-squares deconvolution based analysis of stellar spectra

In recent years, astronomical photometry has been revolutionised by space missions such as MOST, CoRoT and Kepler. However, despite this progress, high-quality spectroscopy is still required as well. Unfortunately, high-resolution spectra can only be obtained using ground-based telescopes, and since many interesting targets are rather faint, the spectra often have a relatively low S/N. Consequently, we have developed an algorithm based on the least-squares deconvolution profile, which allows to reconstruct an observed spectrum, but with a higher S/N. We have successfully tested the method using both synthetic and observed data, and in combination with several common spectroscopic applications, such as e.g. the determination of atmospheric parameter values, and frequency analysis and mode identification of stellar pulsations.Comment: Proceedingspaper, 8 pages, 4 figures, appears in "Setting a New Standard in the Analysis of Binary Stars", Eds K. Pavlovski, A. Tkachenko, and G. Torres, EAS Publications Serie

The interior angular momentum of core hydrogen burning stars from gravity-mode oscillations

A major uncertainty in the theory of stellar evolution is the angular momentum distribution inside stars and its change during stellar life. We compose a sample of 67 stars in the core-hydrogen burning phase with a $\log\,g$ value from high-resolution spectroscopy, as well as an asteroseismic estimate of the near-core rotation rate derived from gravity-mode oscillations detected in space photometry. This assembly includes 8 B-type stars and 59 AF-type stars, covering a mass range from 1.4 to 5\,M$_\odot$, i.e., it concerns intermediate-mass stars born with a well-developed convective core. The sample covers projected surface rotation velocities $v\sin\,i \in[9,242]\,$km\,s$^{-1}$ and core rotation rates up to $26\mu$Hz, which corresponds to 50\% of the critical rotation frequency. We find deviations from rigid rotation to be moderate in the single stars of this sample. We place the near-core rotation rates in an evolutionary context and find that the core rotation must drop drastically before or during the short phase between the end of the core-hydrogen burning and the onset of core-helium burning. We compute the spin parameter, which is the ratio of twice the rotation rate to the mode frequency (also known as the inverse Rossby number), for 1682 gravity modes and find the majority (95\%) to occur in the sub-inertial regime. The ten stars with Rossby modes have spin parameters between 14 and 30, while the gravito-inertial modes cover the range from 1 to 15.Comment: Manuscript of 5 pages, including 2 figures, accepted for publication in The Astrophysical Journal Letter

Особливості комерціалізації результатів біотехнологічної промисловості

Метою статті є визначення галузевих особливостей комерціалізації науково-технічних та інженерних розробок в галузі біотехнології. Відповідно до поставленої мети основними завданнями є: з’ясувати ознаки біотехнологічних виробництв та визначити їх вплив на комерціалізацію науково-технічних розробок в галузі біотехнології; проаналізувати існуючі форми комерціалізації інноваційних розробок та з’ясувати можливість їх застосування у біотехнології; окреслити особливості та пов’язані з ними проблеми комерціалізації науково-технічних та інженерних розробок в галузі біотехнології. Стаття визначає поняття комерціалізації, розглядає процес комерціалізації науково-технічних та інноваційних розробок. Доводить актуальність і необхідність комерціалізації інноваційних розробок як відповідь на зростаючі потреби споживачів та розвитку ринку в цілому. Робота вказує на міждисциплінарність біотехнології як науки та її поширення у різні сфери життя суспільства, через «кольорову» класифікацію. Визначено особливості комерціалізації в сфері біотехнологічної промисловості. Автор визначає головні характеристики біотехнологій: складність структури біотехнологічних продуктів, складність виробництв, недосконалість методів контролю якості, відсутність клінічної історії у препаратів, вказує на їхній вплив на комерціалізацію розробок в галузі. У статті вказується, що особливості галузі можна умовно поділити на ті, що мають безпосередній та опосередкований вплив на комерціалізацію. В дослідженні представлені існуючі форми комерціалізації науково-технічних розробок, а саме: використання у власному виробництві, лізинг, інжиніринг, франчайзинг, промислова кооперація, ліцензійні угоди, а також розглядаються можливості застосування їх у сфері біотехнології. Не всі форми комерціалізації можливо застосовувати в даній галузі, особливо це стосується такої форми як франчайзинг. Наукова новизна даного дослідження полягає в обґрунтуванні впливу характерних ознак галузі на процеси комерціалізації в біотехнології, вибору форм комерціалізації, визначенні та систематизації проблем, вирішення яких дозволить спростити процеси комерціалізації біотехнологічних розробок.The purpose of the study is to determine the specific features of the commercialization of scientific and engineering developments in the field of biotechnology. According to the goal, the main tasks are: to find out specific features of biotechnology production and determine their impact on the commercialization of scientific and technological developments in the field of biotechnology; to analyse existing forms of commercialization of innovative developments and to find out the possibility of their application in biotechnology; to outline the features and related problems of commercialization of scientific and engineering developments in the biotechnology industry. The article defines commercialization, consider on commercialization of scientific and technical innovative developments. It demonstrates urgency and necessity of innovative developments commercialization as an answer to the growing needs of consumers and market evolution. The study argues the interdisciplinary of biotechnology and its distribution in various spheres of life through colour classification. It determines the features of commercialization in biotechnology. The author describes the main characteristics of biotechnologies: complexity of the structure of biotechnological products, the complexity of production, the imperfection of quality control methods, and the lack of clinical history of drugs. She insists on their great influence on the commercialization of developments of the industry. The article shows that all the characteristics of biotechnologies can be divided into those that have a direct and indirect impact on their commercialization. It enumerates the forms of commercialization of scientific and technical developments: use in their own production, leasing, engineering, franchising, industrial cooperation, license agreements and consider on the possibility of their application in biotechnology. Not all forms of commercialization can be applied in the industry and franchising definitely can’t. The scientific novelty of this study is to substantiate the influence of the characteristic features of the industry on the processes of commercialization in biotechnology, the choice of forms of commercialization, the definition and systematization of problems, the solution of which will simplify the processes of commercialization of biotechnological developments

Образ наратора у малій прозі Осипа Турянського

У статті досліджується образ наратора у малій прозі Осипа Турянського, з’ясовуються формальні та змістові домінанти художніх текстів письменника. Особлива увага звернена на жанрові пошуки автора, засоби характеротворення, розкриття світоглядних позицій персонажів та структуротвірних складників творів. Осип Турянський презентує різножанрові художні тексти у малій прозі, а саме: притча, замальовка, оповідання. Зображаючи звичайних людей та їхні повсякденні клопоти, він зосереджує увагу на дослідженні характерів, які мають відмінні пріоритети, по-різному сприймають буття і відповідають на його запити залежно від віку, стану, статі, однак залишаються членами єдиної громади. Наратор у творах може відігравати роль спостерігача («Де сонце»), співрозмовника автора, читача й учасника дійства («Ех, коб мене були вчили»), розповідача і коментатора («Курка»). Відповідно до змістового стрижня тексту Осип Турянський використовує образи-символи, типажі, фольклорний ін- тертекст, але водночас він порушує актуальні освітні, політичні, соціальні та філософські проблеми. (The article deals with the narrator’s image in the small prose by Osyp Turianskyj. It investigates the main formal and sense components of the short stories and picks out the peculiarities of the writer’s individual style. The research reveals the author’s accents in the reflection of vital problems and situations. The writer represents ordinary week-days of Ukrainians. Osyp Turianskyj raises philosophic, political, national, educational and ethical questions. He analyzes the age difference of the world outlook and disposition in the original parable «Where is the Sun». The author opens the characters in the dialogue between grandpa and grandchild. The boy helps grandfather to understand that sunshine is in the heart. The narrator is the observer only Osyp Turianskyi chooses polylogue as the verbal picture of the human variety in the story «Oh, if I was taught». The writer performs the feast in honour of the graduate Pavlo. That is why the education becomes text’s pivot. The narrator participates in the feast as observer and commentator of the event. So he is co-author and the interlocutor of the reader. The story «Hen» is the literary interpretation of the folk anecdote. The narrator tells about the christening of the peasant children and describes the different emotions of the characters. The small prose by Osyp Turianskyi presented the variety of the genres, interesting characters and different functions of the narrator. The writer enriched the Ukrainian literature of the beginning of the 20th century.

Robust propagation direction of stresses in a minimal granular packing

By employing the adaptive network simulation method, we demonstrate that the ensemble-averaged stress caused by a local force for packings of frictionless rigid beads is concentrated along rays whose slope is consistent with unity: forces propagate along lines at 45 degrees to the horizontal or vertical. This slope is shown to be independent of polydispersity or the degree to which the system is sheared. Further confirmation of this result comes from fitting the components of the stress tensor to the null stress constitutive equation. The magnitude of the response is also shown to fall off with the -1/2 power of distance. We argue that our findings are a natural consequence of a system that preserves its volume under small perturbations.Comment: 8 pages, 6 figures. Some extra clarification and minor improvements. To appear in EPJ-

Tkachenko modes as sources of quasiperiodic pulsar spin variations

We study the long wavelength shear modes (Tkachenko waves) of triangular lattices of singly quantized vortices in neutron star interiors taking into account the mutual friction between the superfluid and the normal fluid and the shear viscosity of the normal fluid. The set of Tkachenko modes that propagate in the plane orthogonal to the spin vector are weakly damped if the coupling between the superfluid and normal fluid is small. In strong coupling, their oscillation frequencies are lower and are undamped for small and moderate shear viscosities. The periods of these modes are consistent with the observed ~100-1000 day variations in spin of PSR 1828-11.Comment: 7 pages, 3 figures, uses RevTex, v2: added discussion/references, matches published versio

Giant Vortex Lattice Deformations in Rapidly Rotating Bose-Einstein Condensates

We have performed numerical simulations of giant vortex structures in rapidly rotating Bose-Einstein condensates within the Gross-Pitaevskii formalism. We reproduce the qualitative features, such as oscillation of the giant vortex core area, formation of toroidal density hole, and the precession of giant vortices, observed in the recent experiment [Engels \emph{et.al.}, Phys. Rev. Lett. {\bf 90}, 170405 (2003)]. We provide a mechanism which quantitatively explains the observed core oscillation phenomenon. We demonstrate the clear distinction between the mechanism of atom removal and a repulsive pinning potential in creating giant vortices. In addition, we have been able to simulate the transverse Tkachenko vortex lattice vibrations.Comment: 5 pages, 6 figures; revised description of core oscillation, new subfigur

Yorke and Wright 3/2-stability theorems from a unified point of view

We consider a family of scalar delay differential equations $x'(t)=f(t,x_t)$, with a nonlinearity $f$ satisfying a negative feedback condition combined with a boundedness condition. We present a global stability criterion for this family, which in particular unifies the celebrated 3/2-conditions given for the Yorke and the Wright type equations. We illustrate our results with some applications.Comment: 10 pages, accepted for publication in the Expanded Volume of DCDS, devoted to the fourth international conference on Dynamical Systems and Differential Equations, held at UNC at Wilmington, May 2002. Minor changes from the previous versio

Collective Oscillations of Vortex Lattices in Rotating Bose-Einstein Condensates

The complete low-energy collective-excitation spectrum of vortex lattices is discussed for rotating Bose-Einstein condensates (BEC) by solving the Bogoliubov-de Gennes (BdG) equation, yielding, e.g., the Tkachenko mode recently observed at JILA. The totally symmetric subset of these modes includes the transverse shear, common longitudinal, and differential longitudinal modes. We also solve the time-dependent Gross-Pitaevskii (TDGP) equation to simulate the actual JILA experiment, obtaining the Tkachenko mode and identifying a pair of breathing modes. Combining both the BdG and TDGP approaches allows one to unambiguously identify every observed mode.Comment: 5 pages, 4 figure