J08069+1527: A newly discovered high amplitude, hybrid subdwarf B pulsator

We present our discovery of a new hybrid pulsating subdwarf B star, J08069+1527. The effective temperature and surface gravity of 28,500$\pm$400\,K and 5.37$\pm$0.04\,dex, respectively, place this object inside the instability strip and also among other pulsating hot subdwarfs of a hybrid nature, right next to another fascinating star: Balloon\,090100001. From this proximity, we anticipated this star could pulsate in both high and low frequency modes. Indeed, our analysis of photometric data confirmed our prediction. We detected two peaks in the high frequency region and two other peaks at low frequencies. In addition, the amplitude of the dominant mode is very high and comparable to the dominant peaks in other hybrid subdwarf B stars. Since this star is bright, we performed time-series low resolution spectroscopy. Despite a low signal-to-noise (S/N) ratio, we were able to detect the main peak from these data. All our results strongly indicate that J08069+1527 is a high amplitude pulsating hot subdwarf B star of hybrid nature. By analogy to the other pulsating sdB star, we judge that the dominant mode we detected here has radial nature. Future stellar modeling should provide us with quite good constrains as p- and g-modes presented in this star are driven in different parts of its interior.Comment: 7 pages, 10 figures, accepted for publication in MNRA

The pulsating hot subdwarf Balloon 090100001: results of the 2005 multisite campaign

We present the results of a multisite photometric campaign on the pulsating sdB star Balloon 090100001. The star is one of the two known hybrid hot subdwarfs with both long- and short-period oscillations. The campaign involved eight telescopes with three obtaining UBVR data, four B-band data, and one Stromgren uvby photometry. The campaign covered 48 nights, providing a temporal resolution of 0.36microHz with a detection threshold of about 0.2mmag in B-filter data. Balloon 090100001 has the richest pulsation spectrum of any known pulsating subdwarf B star and our analysis detected 114 frequencies including 97 independent and 17 combination ones. The strongest mode (f_1) in the 2.8mHz region is most likely radial while the remaining ones in this region form two nearly symmetric multiplets: a triplet and quintuplet, attributed to rotationally split \ell=1 and 2 modes, respectively. We find clear increases of splitting in both multiplets between the 2004 and 2005 observing campaigns, amounting to 15% on average. The observed splittings imply that the rotational rate in Bal09 depends on stellar latitude and is the fastest on the equator. We use a small grid of models to constrain the main mode (f_1), which most likely represents the radial fundamental pulsation. The groups of p-mode frequencies appear to lie in the vicinity of consecutive radial overtones, up to the third one. Despite the large number of g-mode frequencies observed, we failed to identify them, most likely because of the disruption of asymptotic behaviour by mode trapping. The observed frequencies were not, however, fully exploited in terms of seismic analysis which should be done in the future with a larger grid of reliable evolutionary models of hot subdwarfs.Comment: accepted for publication in MNRA

All-trans retinoic acid release from biodegradable polyester microcapsules

[Excerpt] Tissue engineering strategies frequently include a scaffold, living cells and bioactive substances to promote cell growth and guide cell differentiation. The encapsulation in carriers enables protects the bioactivity of those substances upon implantation, avoids being transported by the body fluids and also allows controlling the release rate. Encapsulation materials are preferably biodegradable polymers. In this work, all-trans retinoic acid (atRA) was used as a model bioactive agent; since it was shown that atRA enhances the expression of osteocalcin, a specific osteogenic marker. [...]info:eu-repo/semantics/publishedVersio

Nuclear fragmentation: sampling the instabilities of binary systems

We derive stability conditions of Asymmetric Nuclear Matter ($ANM$) and discuss the relation to mechanical and chemical instabilities of general two-component systems. We show that the chemical instability may appear as an instability of the system against isoscalar-like rather than isovector-like fluctuations if the interaction between the two constituent species has an attractive character as in the case of $ANM$. This leads to a new kind of liquid-gas phase transition, of interest for fragmentation experiments with radioactive beams.Comment: 4 pages (LATEX), 3 Postscript figures, improved version, added reference

On the Invariant Theory of Weingarten Surfaces in Euclidean Space

We prove that any strongly regular Weingarten surface in Euclidean space carries locally geometric principal parameters. The basic theorem states that any strongly regular Weingarten surface is determined up to a motion by its structural functions and the normal curvature function satisfying a geometric differential equation. We apply these results to the special Weingarten surfaces: minimal surfaces, surfaces of constant mean curvature and surfaces of constant Gauss curvature.Comment: 16 page

Classification of integrable Weingarten surfaces possessing an sl(2)-valued zero curvature representation

In this paper we classify Weingarten surfaces integrable in the sense of soliton theory. The criterion is that the associated Gauss equation possesses an sl(2)-valued zero curvature representation with a nonremovable parameter. Under certain restrictions on the jet order, the answer is given by a third order ordinary differential equation to govern the functional dependence of the principal curvatures. Employing the scaling and translation (offsetting) symmetry, we give a general solution of the governing equation in terms of elliptic integrals. We show that the instances when the elliptic integrals degenerate to elementary functions were known to nineteenth century geometers. Finally, we characterize the associated normal congruences

Growth of a bonelike apatite on chitosan microparticles after a calcium silicate treatment

Bioactive chitosan microparticles can be prepared successfully by treating them with a calcium silicate solution and then subsequently soaking them in simulated body fluid (SBF). Such a combination enables the development of bioactive microparticles that can be used for several applications in the medical field, including injectable biomaterial systems and tissue engineering carrier systems. Chitosan microparticles, 0.6 lm in average size, were soaked either for 12 h in fresh calcium silicate solution (condition I) or for 1 h in calcium silicate solution that had been aged for 24 h before use (condition II). Afterwards, they were dried in air at 60 !C for 24 h. The samples were then soaked in SBF for 1, 3 and 7 days. After the condition I calcium silicate treatment and the subsequent soaking in SBF, the microparticles formed a dense apatite layer after only 7 days of immersion, which is believed to be due to the formation of silanol (Si– OH) groups effective for apatite formation. For condition II, the microparticles successfully formed an apatite layer on their surfaces in SBF within only 1 day of immersion.I.B.L. thanks the Portuguese Foundation for Science and Technology (FCT), for providing her a PhD scholarship (SFRH/BD/9031/2002), the European Union funded STREP Project HIPPOCRATES (NMP3-CT-2003-505758) and the European NoE EXPERTISSUES (NMP3-CT-2004-500283)

СТВОРЕННЯ ПРОГРАМНОГО ЗАБЕЗПЕЧЕННЯ ДЛЯ ВИМІРЮВАЛЬНОГО КОМПЛЕКСУ МАГНІТОМЕТРІВ LEMI-30

Introduction. Over the past decades, the development of technology and digital devices has been steadily gaining momentum and is increasingly becoming an important part of our daily lives. It is difficult to imagine a modern person who would not use various devices in our time, both at home and at work. Every day, these devices develop, update, improve, and become more convenient and understandable for use in various spheres of life. Achievements in the development of computer technology allow to significant increase the speed of devices to thousands and even millions of measurements per second, as well as to improve the methods and methods of automated control of technological equipment of various types of activities. The results of progress are reflected in the improvement of the quality of devices while reducing their size and updating the software.The magnetic field, which is caused by the sources of the Earth's orbit and the sources inside the Earth's surface, has a significant impact on the biochemical processes of organisms. People are exposed to its influence every minute, both positive and negative. Magnetometers are designed to measure the characteristics of the magnetic field and magnetic properties of materials, and their use allows predicting of negative phenomena and preventing their impact on humanity.Purpose. Currently, the creation of software that would allow the user to easily interact with the device through a convenient and understandable interface remains relevant. The purpose of the work is to develop such software for the lemi-30 measuring complex of magnetometers that can be used during the study of the magnetic field on the earth's surface. This software will facilitate interaction with this type of device. This program can be useful in predicting earthquakes due to changes in the Earth's magnetic field.Results. As a result of the analysis of the existing software for this type of device, an application was developed in the Python programming language. To develop the program interface, a GUI designer was chosen. In addition to Microsoft Visual Studio, a cross-platform tool Qt was used. Having considered the functionality of the existing software, the developed interface takes into account and implements factors that will make this program more convenient, mobile and flexible. In particular, the program code for the initialisation of serial ports was added, and the ability to view free ports in the system was added. The ability to start recording the obtained results will allow you to record data from any moment of the study. Added display of data stream with a fixed delay. During the operation of the device, you can display the data received at the time of recording and display the recording of the main steps when using the device after the end  of the operation. The ability to complete the recording of the obtained results at any time and save the records with the possibility of their further use for analysis or forecasting is also of great importance.Conclusions. Induction satellite synchronized 3-component magnetometers, which are designed for the study of magnetic field fluctuations on the Earth's surface, are ideal for monitoring earthquakes and the influence of the magnetic field on the processes associated with it. Such devices require high-quality software. An understandable interface will allow you to expand the use of the device, attracting a larger audience. And the functionality of the application can be modernised in the future, by choosing the latest technologies and taking into account the needs of users. Creating software for the measuring complex of lemi-30 magnetometers is relevant and in demand.Проблема. За останні десятиліття розвиток технологій і цифрових приладів невпинно набирає обертів і дедалі більше впливає на наше повсякденне життя. Важко уявити сучасну людину, яка б у наш час не використовувала різноманітні прилади, як у побуті, так і на роботі. З кожним днем ці прилади розвиваються, оновлюються, вдосконалюються, стають зручнішими та зрозумілішими для використання в різних сферах життя. Досягнення розвитку обчислювальної техніки дає змогу значно збільшити швидкодію приладів до тисяч і навіть мільйонів вимірів на 1 секунду, також покращити методи і способи автоматизованого керування технологічним устаткуванням різного роду діяльності. Результати прогресу відображаються в підвищенні якості приладів при зменшенні їх розмірів і оновленні програмного забезпечення.Магнітне поле, яке зумовлене джерелами навколоземного простору і джерелами всередині земної кулі, має неабиякий вплив на біохімічні процеси організмів. Люди щохвилини піддаються його дії, як позитивній так і негативній. Магнітометри призначені для вимірювання характеристик магнітного поля та магнітних властивостей матеріалів, а їх використання дає можливість передбачати негативні явища запобігаючи їх впливу на людство.Мета. На даний час залишається актуальним створення програмного забезпечення (ПЗ), яке б дало змогу легко взаємодіяти користувачу з апаратом через зручний і зрозумілий інтерфейс. Метою роботи є розробка такого програмного забезпечення для вимірювального комплексу магнітометрів lemi-30, яке можна використовувати в ході дослідження магнітного поля на земній поверхні. Це ПЗ полегшить взаємодію з такого типу приладами. І ця програма може бути корисною при прогнозуванні землетрусів внаслідок зміни магнітного поля Землі.Результати дослідження. В результаті проведеного аналізу існуючого програмного забезпечення для такого типу приладів було розроблено додаток мовою програмування Python. Для розробки інтерфейсу програми обрано конструктор для розробки GUI. Окрім Microsoft Visual Studio, був використаний кросплатформенний засіб Qt. Розглянувши функціонал існуючого ПЗ, у розробленому інтерфейсі враховані і реалізовані фактори, які зроблять дану програму зручнішою, мобільнішою і гнучкішою. Зокрема, було додано програмний код для ініціалізації серійних портів, додано можливість переглянути вільні порти у системі. Можливість почати запис отримуваних результатів дозволить фіксувати дані із будь-якого моменту дослідження. Додали відображення потоку даних з фіксованою затримкою. Під час роботи приладу можна відображати дані, які надійшли в момент запису і відображати запис основних кроків при використанні приладу після закінчення роботи. Велике значення має і можливість завершити запис отримуваних результатів в будь який момент та збереження записів з можливістю їх подальшого використання для аналізу чи прогнозування.Висновки. Індукційні супутникові синхронізовані 3-компонентні магнітометри, які призначені для дослідження коливань магнітного поля на земній поверхні ідеально підходять для моніторингу землетрусів і впливу магнітного поля на процеси, які з цим пов’язані. Такі прилади потребують якісного програмного забезпечення. Зрозумілий інтерфейс дозволить розширити використання приладу, залучивши більшу аудиторію. А функціональні можливості додатку можна надалі модернізувати, обираючи новітні технології і враховуючи потреби користувачів. Створення програмного забезпечення для вимірювального комплексу магнітометрів lemi-30 є актуальним і затребуваним

Coulomb effects on growth of instabilities in asymmetric nuclear matter

We study the effects of the Coulomb interaction on the growth of unstable modes in asymmetric nuclear matter. In order to compare with previous calculations we use a semiclassical approach based on the linearized Vlasov equation. Moreover, a quantum calculation is performed within the R.P.A.. The Coulomb effects are a slowing down of the growth and the occurrence of a minimal wave vector for the onset of the instabilities. The quantum corrections cause a further decrease of the growth rates.Comment: 10 pages, revtex, 4 ps figures, to appear in Phys. Rev. C e-mail: [email protected], [email protected]

Analysis of the rich frequency spectrum of KIC 10670103 revealing the most slowly rotating subdwarf B star in the Kepler field

We analyse 2.75 yr of Kepler spacecraft observations of the pulsating subdwarf B star KIC 10670103. These 1.4 million measurements have an impressive duty cycle of 93.8 per cent, a frequency resolution of 0.017 μHz, and a 5σ detection limit of 0.1 parts-per-thousand (ppt). We detect 278 periodicities, making KIC 10670103 the richest pulsating subdwarf B star to date. Frequencies range from 23 to 673 μHz (0.4 and 11.8 h), with amplitudes from the detection limit up to 14 ppt. Follow-up spectroscopic data were obtained from which it was determined that KIC 10670103 does not show significant radial velocity variations. Updated atmospheric model fits determined Teff = 21 485 ± 540 K, log g = 5.14 ± 0.05, and log N(He)/N(H) = -2.60 ± 0.04. We identify pulsation modes using asymptotic period spacings and frequency multiplets. The frequency multiplets indicate a spin period of 88 ± 8 d. Of the 278 periodicities detected in KIC 10670103, 163 (59 per cent) have been associated with low-degree (ℓ ≤ 2) pulsation modes, providing tight constraints for model fitting. While the data are exquisite, amplitudes (and some frequencies) are not stable over the course of the observations, requiring tools which are non-standard for compact pulsators such as sliding Fourier transforms and Lorentzian fitting. Using the 163 identified pulsation modes, it is possible to make detailed examinations of the pulsation structure; including where the pulsation power is concentrated in radial order, over what frequency range mode trapping is inefficient, and how power switches between multiplet members