Theory of highly loaded coal-water slurries

There has been analyzed the existing schemes of strapping of circulated system of drilling set during drilling with well washing by the foam and argued the necessity of its efficient raising; there has been chosen the scheme of strapping of circulated system during drilling with well washing by the foam for the possibility of the most rational usage of existing foamgenerating equipment.В статті проаналізовані існуючі схеми обв'язки циркуляційної системи бурової установки при бурінні з промиванням свердловини піною та обґрунтована необхідність підвищення їх ефективності; для можливості найбільш раціонального використання існуючого піногенеруючого устаткування передбачена схема обв'язки циркуляційної системи при бурінні з промиванням свердловини піною

Upconversion assisted self-pulsing in a high-concentration erbium doped fiber laser

We report results on experimental and theoretical characterisation of self-pulsing in high concentration erbium doped fibre laser which is free from erbium clusters. Unlike previous models of self-pulsing accounting for pair-induced quenching (PIQ) on the clustered erbium ions, new model has been developed with accounting for statistical nature of the excitation migration and upconversion and resonance-like pumpto-signal intensity noise transfer. The obtained results are in a good agreement with the experimental data

Resonance vector mode locking

A mode locked fibre laser as a source of ultra-stable pulse train has revolutionised a wide range of fundamental and applied research areas by offering high peak powers, high repetition rates, femtosecond range pulse widths and a narrow linewidth. However, further progress in linewidth narrowing seems to be limited by the complexity of the carrier-envelope phase control. Here for the first time we demonstrate experimentally and theoretically a new mechanism of resonance vector self-mode locking where tuning in-cavity birefringence leads to excitation of the longitudinal modes sidebands accompanied by the resonance phase locking of sidebands with the adjacent longitudinal modes. An additional resonance with acoustic phonons provides the repetition rate tunability and linewidth narrowing down to Hz range that drastically reduces the complexity of the carrier-envelope phase control and so will open the way to advance lasers in the context of applications in metrology, spectroscopy, microwave photonics, astronomy, and telecommunications

Time delay between images of the lensed quasar UM673

We study brightness variations in the double lensed quasar UM673 (Q0142-100) with the aim of measuring the time delay between its two images. In the paper we combine our previously published observational data of UM673 obtained during the 2003 - 2005 seasons at the Maidanak Observatory with archival and recently observed Maidanak and CTIO UM673 data. We analyze the V, R and I-band light curves of the A and B images of UM673, which cover ten observational seasons from August 2001 to November 2010. We also analyze the time evolution of the difference in magnitudes between images A and B of UM673 over more than ten years. We find that the quasar exhibits both short-term (with amplitude of \sim 0.1 mag in the R band) and high-amplitude (\sim 0.3 mag) long-term variability on timescales of about several months and several years, respectively. These brightness variations are used to constrain the time delay between the images of UM673. From cross-correlation analysis of the A and B quasar light curves and error analysis we measure the mean time delay and its error of 89 \pm11 days. Given the input time delay of 88 days, the most probable value of the delay that can be recovered from light curves with the same statistical properties as the observed R-band light curves of UM673 is 95{+5/-16}{+14/-29} days (68 and 95 % confidence intervals). Analysis of the V - I color variations and V, R and I-band magnitude differences of the quasar images does not show clear evidence of the microlensing variations between 1998 and 2010.Comment: Submitted to A&A, 11 pages, 9 figure

Time delays in PG1115+080: new estimates

We report new estimates of the time delays in the quadruple gravitationally lensed quasar PG1115+080, obtained from the monitoring data in filter R with the 1.5-m telescope at the Maidanak Mountain (Uzbekistan, Central Asia) in 2004-2006. The time delays are 16.4 days between images C and B, and 12 days between C and A1+A2, with image C being leading for both pairs. The only known estimates of the time delays in PG1115 are those based on observations by Schechter et al. (1997) -- 23.7 and 9.4 days between images C and B, C and A1+A2, respectively, as calculated by Schechter et al., and 25 and 13.3 days as revised by Barkana (1997) for the same image components with the use of another method. The new values of time delays in PG 1115+080 may be expected to provide larger estimates of the Hubble constant thus decreasing a diversity between the H_0 estimates taken from gravitationally lensed quasars and with other methods.Comment: 5 pages, 2 figures, Accepted for publication in MNRAS Letter

PG 1115+080: variations of the A2/A1 flux ratio and new values of the time delays

We report the results of our multicolor observations of PG 1115+080 with the 1.5-m telescope of the Maidanak Observatory (Uzbekistan, Central Asia) in 2001-2006. Monitoring data in filter R spanning the 2004, 2005 and 2006 seasons (76 data points) demonstrate distinct brightness variations of the source quasar with the total amplitude of almost 0.4 mag. Our R light curves have shown image C leading B by 16.4d and image (A1+A2) by 12d that is inconsistent with the previous estimates obtained by Schechter et al. in 1997 - 24.7d between B and C and 9.4d between (A1+A2) and C. The new values of time delays in PG 1115+080 must result in larger values for the Hubble constant, thus reducing difference between its estimates taken from the gravitational lenses and with other methods. Also, we analyzed variability of the A2/A1 flux ratio, as well as color changes in the archetypal "fold" lens PG 1115+080. We found the A1/A2 flux ratio to grow during 2001-2006 and to be larger at longer wavelengths. In particular, the A2/A1 flux ratio reached 0.85 in filter I in 2006. We also present evidence that both the A1 and A2 images might have undergone microlensing during 2001-2006, with the descending phase for A1 and initial phase for A2. We find that the A2/A1 flux ratio anomaly in PG 1115 can be well explained both by microlensing and by finite distance of the source quasar from the caustic fold.Comment: 14 pages, 7 figures, 8 tables, Accepted for publication in MNRA

The astrometric Gaia-FUN-SSO observation campaign of 99 942 Apophis

Astrometric observations performed by the Gaia Follow-Up Network for Solar System Objects (Gaia-FUN-SSO) play a key role in ensuring that moving objects first detected by ESA's Gaia mission remain recoverable after their discovery. An observation campaign on the potentially hazardous asteroid (99 942) Apophis was conducted during the asteroid's latest period of visibility, from 12/21/2012 to 5/2/2013, to test the coordination and evaluate the overall performance of the Gaia-FUN-SSO . The 2732 high quality astrometric observations acquired during the Gaia-FUN-SSO campaign were reduced with the Platform for Reduction of Astronomical Images Automatically (PRAIA), using the USNO CCD Astrograph Catalogue 4 (UCAC4) as a reference. The astrometric reduction process and the precision of the newly obtained measurements are discussed. We compare the residuals of astrometric observations that we obtained using this reduction process to data sets that were individually reduced by observers and accepted by the Minor Planet Center. We obtained 2103 previously unpublished astrometric positions and provide these to the scientific community. Using these data we show that our reduction of this astrometric campaign with a reliable stellar catalog substantially improves the quality of the astrometric results. We present evidence that the new data will help to reduce the orbit uncertainty of Apophis during its close approach in 2029. We show that uncertainties due to geolocations of observing stations, as well as rounding of astrometric data can introduce an unnecessary degradation in the quality of the resulting astrometric positions. Finally, we discuss the impact of our campaign reduction on the recovery process of newly discovered asteroids.Comment: Accepted for publication in A&

Морфофункциональная характеристика отека-набухания коры головного мозга белых крыс после тяжелой черепно-мозговой травмы без и на фоне применения L-лизина эсцината

Aim of study The study is devoted to a morphometric assessment of the manifestations of edema-swelling of the somatosensory cortex (SSC) of the brain of white rats after severe traumatic brain injury (TBI) without using L-lysine escinate and when using it as a therapeutic effect.Material and methods We stained sections with hematoxylin-eosin and performed morphometric methods. On thin (4 μm) serial frontal sections of SSC, neurons and microvessels in the control (intact animals, n=5) were examined in 1 (n= 5), 3 (n=5), 5 (n=5), 7 (n=5) and 14 (n=5) days after injury without treatment (n=25, comparison group) and with treatment (n=25, main group). In color raster images (lens x100), using the plug-in filter “Find Maxima”, maximum brightness areas (MBA) were determined , which were then analyzed using the “Analyze Particles” program from ImageJ 1.52 s. MBA corresponded to SSC sites with a high degree of hydration of nerve tissue - edema-swelling. Statistical hypotheses were tested using nonparametric criteria.Results and discussion In control animals, a low degree of hydration of SSC tissue was noted (relative area 3-8%). In the comparison group, 1 and 3 days after STBI, foci of edema-swelling covered up to 30% of SSC, in 5 days - up to 15%, in 7 days - up to 20%, in 15 - up to 18%. Significant heteromorphism and heterogeneity of changes in the neuropil around neurons and blood vessels was noted. In the dynamics of the post-traumatic period, the proportion of large foci of edema-swelling (intra- and perineuronal, perivascular) decreased. In the main group, one day after STBI, there was a statistically significantly smaller number of foci of edema-swelling and their total relative area. The values range of these variables significantly decreased. L-lysine escinat affected the water balance most effectively in the acute post-traumatic period (day 1 and 3). The drug “smoothed out” the manifestation peaks (number, focal area) of edema-swelling: the values of the studied morphometric indicators were statistically significantly different. Consequently, morphometric signs of hydropic dystrophy after STBI were detected in both studied groups during the 15 days of observation.Conclusion The degree of SSC nervous tissue hydration increased after STBI. L-lysine escinate statistically significantly reduced manifestations of hydropic dystrophy. The drug significantly affected the degree of hydration of neural tissue observed in the early post-traumatic period.Цель Исследование посвящено морфометрической оценке проявлений отека-набухания соматосенсорной коры (ССК) головного мозга белых крыс после тяжелой черепно-мозговой травмы (ТЧМТ) на фоне использования в качестве лечебного воздействия L-лизина эсцината.Методы исследования Использована окраска срезов гематоксилином-иозином и методы морфометрии. На тонких (4 мкм) серийных фронтальных срезах ССК изучены нейроны и микрососуды в контроле (интактные животные, n=5), через 1 (n=5), 3 (n=5), 5 (n=5), 7 (n=5) и 14 (n=5) суток после травмы без лечения (n=25, группа сравнения) и с лечением (n=25, основная группа). На цветных растровых изображениях (объектив х100) с помощью плагин-фильтра “Find Maxima” определяли зоны максимальной яркости, которые затем анализировали с помощью “Analyze Particles” из программы ImageJ 1.52s. Зоны соответствовали участкам ССК с высокой степенью гидратации нервной ткани - отек-набухание. Статистические гипотезы проверяли с помощью непараметрических критериев.Результаты и обсуждение У контрольных животных отмечена низкая степень гидратации нервной ткани ССК (относительная площадь 3−8%). В группе сравнения через 1 и 3 суток после ТЧМТ очаги отека-набухания охватывали до 30% ССК, через 5 суток - до 15%, через 7 суток - до 20%, через 15 - до 18%. Отмечалась значительная гетероморфность и гетерогенность изменений в нейропиле, вокруг нейронов и сосудов. В динамике посттравматического периода доля крупных очагов отека-набухания (интра- и перинейрональных, периваскулярных) снижалась. В основной группе через одни сутки после ТЧМТ было статистически значимо меньшее количество очагов отека-набухания и их общая относительная площадь была меньше, чем в группе сравнения. Значительно уменьшался разброс значений данных переменных. Наиболее эффективно L-лизина эсцинат действовал на водный баланс в остром посттравматическом периоде (1-е и 3-и сутки). Препарат «сглаживал»  пики проявлений (количество, площадь очагов) отека-набухания: значения изученных морфометрических показателей статистически значимо отличались. Следовательно, морфометрическиепризнаки гидропической дистрофии после ТЧМТ выявлялись в обеих изученных группах на протяжении 15 суток наблюдения.Заключение После ТЧМТ увеличивалась степень гидратации нервной ткани ССК. L-лизин эсцинат статистически значимо уменьшал проявления гидропической дистрофии. Особенно выраженное влияние препарата на степень гидратации нервной ткани отмечено в раннем посттравматическом периоде

The CRESST Dark Matter Search

The current status of CRESST (Cryogenic Rare Event Search using Superconducting Thermometers) and new results concerning the detector development are presented. The basic technique of CRESST is to search for particle Dark Matter (WIMPS, Weakly Interacting Massive particles) by the measurement of non-thermal phonons as created by WIMP-induced nuclear recoils. Combined with the newly developed method of simultaneous measurement of scintillation light, strong background discrimination is possible, resulting in a substantial increase in WIMP detection sensitivity. The short and long term perspectives of CRESST are discussed.Comment: 12 pages, 6 figure