Determination of the time-dependent reaction coefficient and the heat flux in a nonlinear inverse heat conduction problem

Diffusion processes with reaction generated by a nonlinear source are commonly encountered in practical applications related to ignition, pyrolysis and polymerization. In such processes, determining the intensity of reaction in time is of crucial importance for control and monitoring purposes. Therefore, this paper is devoted to such an identification problem of determining the time-dependent coefficient of a nonlinear heat source together with the unknown heat flux at an inaccessible boundary of a one-dimensional slab from temperature measurements at two sensor locations in the context of nonlinear transient heat conduction. Local existence and uniqueness results for the inverse coefficient problem are proved when the first three derivatives of the nonlinear source term are Lipschitz continuous functions. Furthermore, the conjugate gradient method (CGM) for separately reconstructing the reaction coefficient and the heat flux is developed. The ill-posedness is overcome by using the discrepancy principle to stop the iteration procedure of CGM when the input data is contaminated with noise. Numerical results show that the inverse solutions are accurate and stable

PHASES High Precision Differential Astrometry of delta Equulei

delta Equulei is among the most well-studied nearby binary star systems. Results of its observation have been applied to a wide range of fundamental studies of binary systems and stellar astrophysics. It is widely used to calibrate and constrain theoretical models of the physics of stars. We report 27 high precision differential astrometry measurements of delta Equulei from the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES). The median size of the minor axes of the uncertainty ellipses for these measurements is 26 micro-arcseconds. These data are combined with previously published radial velocity data and other previously published differential astrometry measurements using other techniques to produce a combined model for the system orbit. The distance to the system is determined to within a twentieth of a parsec and the component masses are determined at the level of a percent. The constraints on masses and distance are limited by the precisions of the radial velocity data; we outline plans improve this deficiency and discuss the outlook for further study of this binary.Comment: Accepted by AJ. Complete versions of tables 2-7 now available at http://stuff.mit.edu/~matthew1/deltaEquTables/ (removed from astroph server

Гидрофобизация и упрочнение целлюлозных материалов из вторичных ресурсов

The influence of the sizing agent and filler on the physical-mechanical and surface properties of paper from the cellulose mass of the inner layer of the bark of mulberry tree branches has been studied. According to standard methods, the mechanical strength and absorbency were studied. Surface absorbency for one-side wetting was determined by the method of Cobb(30), by determining the mass of water absorbed by the paper surface when wetting one side of the test sample. It was found that it is advisable to add a sizing agent in the range from 1 to 1.5 g per 100 g of dry cellulose raw materials, since an increase in the additive to 2 g helps to reduce the interfiber bonding forces by 21 %. The addition of 6 g of kaolin affects the distance between the fibers, which reduces the mechanical adhesive forces by 12.5 %. During the analysis of the surface properties of paper samples, the sizing efficiency was found to be from 22.5 to 30 % with an increase in the addition of sizing glue, which can be explained by densification of the structure, which prevents the penetration of aqueous solutions. The addition of 2 to 6 g of kaolin also increases water resistance from 17.5 to 25 %. With the help of a mathematical model, rational values of absorbency were revealed with a composition of 92 %, with a sizing agent of 1.5 g and an amount of filler of 4 g. The resulting mathematical model can be used as the basis for controlling the surface characteristics of paper during its production.Исследовано влияние проклеивающего вещества и наполнителя на физико-механические и поверхностные свойства бумаги из целлюлозной массы внутреннего слоя коры веток тутового дерева. По стандартным методикам изучены механическая прочность и впитывающая способность. Поверхностную впитываемость при одностороннем смачивании определяли по методу Кобб(30), путем определения массы воды, поглощенной поверхностью бумаги при смачивании одной стороны испытуемого образца. Выявлено, что целесообразно добавление проклеивающего вещества в пределах от 1 до 1,5 г на 100 г сухого целлюлозного сырья, так как увеличение добавки до 2 г способствует уменьшению межволоконных сил связи на 21 %. Добавление каолина в количестве 6 г влияет на расстояние между волокнами, что уменьшает механические силы сцепления на 12,5 %. В ходе анализа поверхностных свойств образцов бумаги определена эффективность проклейки от 22,5 до 30 % с увеличением проклеивающего вещества, что можно объяснить уплотнением структуры, которая препятствует проникновению водных растворов. Добавление каолина от 2 до 6 г также повышает стойкость к воде от 17,5 до 25 %. С помощью математической модели показаны рациональные значения впитывающей способности при составе бумажной массы 92 % при проклеивающем веществе 1,5 г и количестве наполнителя 4 г. Полученная математическая модель может быть положена в основу управления поверхностных характеристик бумаги в процессе ее производства

Multi-stage urethroplasy for anterior urethral strictures: objective parameters of long-term efficacy and patient-reported outcomes

Introduction. Multi-stage urethral surgery is used in cases of the most complex urethral strictures. The evaluation of surgical treatment results given by patients is a significant criterion for the efficacy of urethroplasty along with the assessment of urethral patency through instrumental examinations.Objective. To evaluate the long-term efficacy of multistage urethroplasty for complex anterior urethral strictures considering the patients' quality of life and satisfaction with the surgical outcomes.Materials and methods. The study included 73 patients aged 18 – 84 years with anterior urethral strictures who underwent multi-stage urethroplasty in 2010 – 2019. Surgical and functional outcomes of urethroplasty were assessed through general blood and urine tests, physical examination, uroflowmetry, and retrograde urethrography and urethroscopy in case of urinary disorders.  Subjective parameters of treatment efficacy were studied using questionnaires: International Prostate Symptom Score (IPSS); Quality of life (QoL); Patient-reported Outcome Measure for Urethral Stricture Surgery (USS-PROM); Patient Global Impression of Improvement (PGI-I).Results. Recurrent urethral stricture was detected in 19 (26,0%) patients with the average follow-up period being 65 months. Independent urination was restored in 71 (97.3%) cases, including repeated interventions. After surgery, there was a significant increase in urinary flow rate parameters (Q max: 8.1 vs 19.1 ml/s, p < 0.0001; Q ave: 5.5 vs 10.7 ml/s; p = 0.0004), decrease in residual urine volume (62.4 vs 18.6 ml, p < 0.0001), decrease in total IPSS score (18.7 vs 5.7 points; p < 0.0001) and QoL index (4.3 vs 1 .8 points, p < 0.0001). A comparative analysis of preoperative and postoperative USS-PROM questionnaire results demonstrated an improvement in indicators assessing LUTS (12.9 vs 3.4 points; p < 0.0001; 3.6 vs 1.7 points; p < 0.0001), and urination-associated quality of life (2.6 vs 0.6 points; p < 0.0001) and overall health (EQ-5D index: 0.73 vs 0.91 points; p = 0.025; EQ-VAS: 68.0 vs 88.1 points, p = 0.004). Fifty-seven (81.4%) men were “very satisfied” or “satisfied” with the treatment outcomes, while nine (12.9%) respondents noted a moderate effect of residual urinary disorders on the quality of life. Significantly higher satisfaction was observed among cystostomy patients and in cases where repeated interventions were unnecessary.Conclusion. Multi-stage urethroplasty for complex anterior urethral strictures achieves efficacy in 97.3% of cases and is accompanied by high levels of quality of life and patient’s satisfaction during long-term follow-up

Поверхностные и оптические свойства бумаги, содержащей карбонат кальция

The article investigates the surface and optical properties of calcium carbonate paper obtained at the UzbekChinese enterprise Fergana stone paper company (Uzbekistan), in order to identify the possibility of their use at printing enterprises for printing multicolor products using traditional printing methods. According to the results of a quantitative assessment of the surface quality by the indirect Beck method, we can say that paper sample 1 has a smoothness like coated paper (750–1500 s), paper samples 2 and 3 – like calendered paper, so that these paper samples can be recommended for prints with increased quality requirements. Smaller values of roughness Ra and small depressions, expressed by darkening in the topographic AFM images, characterized sufficient homogeneity and density of the structure. It was also revealed that the surface of the paper samples has a high ability to specularly reflect the incident light, since the percentage of surface reflection is similar to that of coated papers. Samples of paper have a whiteness of about 90 % and do not have a tint, since the difference between the maximum and minimum values of the reflection coefficients on a white stack is not more than 10 %. The tested paper samples can be recommended without restrictions for double-sided printing, since the opacity index is more than 92 %.Исследованы поверхностные и оптические свойства бумаги из карбоната кальция, полученной в условиях Узбекско-китайского предприятия Fergana stone paper company (Узбекистан), с целью выявления возможности ее использования на полиграфических предприятиях для печати многокрасочной продукции с применением традиционных способов печати. По результатам количественной оценки качества поверхности косвенным методом Бека можно утверждать, что образец бумаги № 1 обладает гладкостью, как у мелованной бумаги (750–1500 с), образцы бумаги № 2 и 3, как у бумаг каландрированных, которые можно рекомендовать для изданий с повышенными требованиями к качеству. Меньшие значения шероховатости Ra и небольшие углубления, выраженные затемнением на топографических АСМ-изображениях, характеризовали достаточную однородность и плотность структуры. Также выявлено, что поверхность образцов бумаги обладает высокой способностью зеркально отражать падающий свет, так как процент отражения поверхностей такой же, как у мелованных бумаг. Образцы бумаги имеют белизну порядка 90 % и нет оттенка, так как разница между максимальным и минимальным значениями коэффициентов отражения на белой стопе не больше 10 %. Исследуемые образцы бумаги можно без ограничений рекомендовать для двусторонней печати, так как показатель светонепроницаемости больше 92 %

The Disk Wind in the Young Binaries and the Origin of the Cyclic Activity of Young Stars

We present results of numerical modeling of the cyclic brightness modulation in the young binary systems with the eccentric orbits and low-mass secondary components. Brightness variations of the primary is due to the periodical extinction variations on the line-of-sight caused by the disk wind of the secondary and a common envelope it produces. A matter distribution in the envelope has been calculated in the ballistic approach. Calculations showed that for the young binaries with the elliptic orbits parameters of the photometric minima (their depth, duration and the shape of light curves) depend not only on the disk wind parameters and an inclination of the binary orbit to the line-of-sight but also on the longitude of the periastron. A modulation of the scattered radiation of the common envelope with a phase of the orbital period has been investigated in the single scattering approach. It is shown that an amplitude of the modulation is maximal when the system is seen edge-on and has also a non-zero value in the binaries observed pole-on. Possible applications of the theory to the young stellar objects are discussed. In particular, an attention is payed to a resemblance of the light curves in some models with light curves of the objects suspected as candidates to FUORs.Comment: 18 pages, 9 figures, accepted by Astronomy Letter

СОЧЕТАНИЕ ТЯЖЕЛОГО ТЕЧЕНИЯ ЯЗВЕННОЙ БОЛЕЗНИ И ГЕМОФИЛИИ В У РЕБЕНКА. КЛИНИЧЕСКОЕ НАБЛЮДЕНИЕ

Gastroduodenal ulcer is less common and milder in children than in adults. Gastroduodenal ulcer complications, such as hemorrhage, penetration etc. are even less common. Recurrent ulcerous defect hemorrhage is a reason to expand diagnostic search and involve various specialists, primarily hematologists, into the diagnosis establishing process. The article presents a clinical case of a child with gastroduodenal ulcer complicated with recurrent hemorrhage not terminated with the standard therapy; thus, additional diagnostic testing was performed. This helped to detect a hematological disease and determine an optimal therapy amount.Язвенная болезнь желудка и двенадцатиперстной кишки у детей встречается реже, чем у взрослых, и отличается более легким течением. Еще реже у детей встречаются осложнения язвенной болезни, такие как кровотечение, пенетрация и др. Рецидивирующие кровотечения из язвенных дефектов являются поводом для расширения диагностического поиска и привлечения к процессу постановки диагноза различных специалистов, в первую очередь гематологов. В статье представлен клинический случай ребенка с язвенной болезнью, осложненной рецидивирующими кровотечениями, которые не купировались при применении стандартной терапии, что послужило причиной для дополнительных диагностических исследований. Это позволило выявить гематологическое заболевание и определить оптимальный объем терапии

PHASES Differential Astrometry and Iodine Cell Radial Velocities of the kappa Pegasi Triple Star System

kappa Pegasi is a well-known, nearby triple star system. It consists of a ``wide'' pair with semi-major axis 235 milli-arcseconds, one component of which is a single-line spectroscopic binary (semi-major axis 2.5 milli-arcseconds). Using high-precision differential astrometry and radial velocity observations, the masses for all three components are determined and the relative inclinations between the wide and narrow pairs' orbits is found to be 43.8 +/- 3.0 degrees, just over the threshold for the three body Kozai resonance. The system distance is determined to 34.60 +/- 0.21 parsec, and is consistent with trigonometric parallax measurements.Comment: Accepted for publication in ApJ, complete versions of tables 2 and 4 can be found at http://stuff.mit.edu/~matthew1/kapPegTables

The GRANDMA network in preparation for the fourth gravitational-wave observing run

GRANDMA is a world-wide collaboration with the primary scientific goal ofstudying gravitational-wave sources, discovering their electromagneticcounterparts and characterizing their emission. GRANDMA involves astronomers,astrophysicists, gravitational-wave physicists, and theorists. GRANDMA is now atruly global network of telescopes, with (so far) 30 telescopes in bothhemispheres. It incorporates a citizen science programme (Kilonova-Catcher)which constitutes an opportunity to spread the interest in time-domainastronomy. The telescope network is an heterogeneous set of already-existingobserving facilities that operate coordinated as a single observatory. Withinthe network there are wide-field imagers that can observe large areas of thesky to search for optical counterparts, narrow-field instruments that dotargeted searches within a predefined list of host-galaxy candidates, andlarger telescopes that are devoted to characterization and follow-up of theidentified counterparts. Here we present an overview of GRANDMA after the thirdobserving run of the LIGO/VIRGO gravitational-wave observatories in $2019-2020$and its ongoing preparation for the forthcoming fourth observational campaign(O4). Additionally, we review the potential of GRANDMA for the discovery andfollow-up of other types of astronomical transients.<br