182 research outputs found
Transformation of university publishing activity based on business processes reengineering
The paper reveals the role of business processes reengineering (BPR) in key organization business processes transformation. Some methods for evaluating business processes effectiveness and BRP tools are reviewed. The main directions of the transformation of business processes in the publishing activities of Polotsk State University are proposed
Transformation of university publishing activity based on business processes reengineering
The paper reveals the role of business processes reengineering (BPR) in key organization business processes transformation. Some methods for evaluating business processes effectiveness and BRP tools are reviewed. The main directions of the transformation of business processes in the publishing activities of Polotsk State University are proposed
Crystal Structure and Physical Properties of U3T3Sn4 (T = Ni, Cu) Single-Crystals
Heat capacity experiments, crystal structure determination and transmission
electron microscopy have been carried out on U3Cu3Sn4 single-crystals. U3Cu3Sn4
was confirmed to be a heavy-fermion antiferromagnet (TN=13(1) K) with a low
temperature electronic heat capacity coefficient gamma=390 mJ/molUK2. Low
temperature heat capacity experiments on a U3Ni3Sn4 single-crystal indicate
that below 0.4 K there is a crossover between the previously observed non-Fermi
liquid behavior and a Fermi liquid state.Comment: 12 pages (incl. 2 tables & 4 figures), to appear in Physica
Recovery of the Fermi-liquid state in U_3Ni_3Sn_4 by pressure
Measurements of the resistivity of single-crystalline U_3Ni_3Sn_4 under
hydrostatic pressure up to 1.8 GPa are reported. We show that the temperature
T_FL, below which the resistivity obeys the Fermi-liquid expression rho ~ T^2,
increases with pressure as T_FL ~ (p-p_c)^1/2. The analysis of the data within
the magnetotransport theory of Rosch lends strong support for an
antiferromagnetic quantum critical point in U_3Ni_3Sn_4 at a negative critical
pressure p_c of -0.04+-0.02 GPa. The proximity to an antiferromagnetic
instability in U_3Ni_3Sn_4 is consistent with the previously reported non-Fermi
liquid term in the low-temperature specific heat.Comment: 14 pages (including 4 figures); pdf forma
Class of Ferromagnetic Semiconductors
Single crystal and polycrystal oxoruthenates having the generalized compositions (Baz,Sr1−z)FexCoyRu6−(x+y)O11 (1≦(x+y)≦5; 0≦z≦1) and (Ba,Sr)M2±xRu4∓xO11 (M=Fe,Co) belong to a novel class of ferromagnetic semiconductors with applications in spin-based field effect transistors, spin-based light emitting diodes, and magnetic random access memories
ВЫЧИСЛЕНИЕ ВЕРШИН ПОЛИТОПОВ РАЗБИЕНИЙ ЧИСЕЛ
The paper describes a method of generating vertices of the polytopes of integer partitions that was used by the authors to calculate all vertices and support vertices of the partition polytopes for all n ≤ 105 and all knapsack partitions of n ≤ 165. The method avoids generating all partitions of n. The vertices are determined with the help of sufficient and necessary conditions; in the hard cases, the well-known program Polymake is used. Some computational aspects are exposed in more detail. These are the algorithm for checking the criterion that characterizes partitions that are convex combinations of two other partitions; the way of using two combinatorial operations that transform the known vertices to the new ones; and employing the Polymake to recognize a limited number (for small n) of partitions that need three or more other partitions for being convexly expressed. We discuss the computational results on the numbers of vertices and support vertices of the partition polytopes and some appealing problems these results give rise to.Описывается метод генерирования вершин политопов разбиений чисел, с помощью которого авторами были вычислены все вершины и опорные вершины политопов разбиений всех n ≤ 105 и все рюкзачные разбиения n ≤ 165. Метод не требует построения всех разбиений n. Вершины определяются с помощью достаточных и необходимых условий, в трудных случаях применяется известная программа Polymake. Подробно излагаются алгоритм проверки критерия, характеризующего разбиения, являющиеся выпуклыми комбинациями двух других; методика применения двух комбинаторных операций, преобразующих известные вершины в новые вершины, и способ применения программы Polymake для распознавания небольшого (для малых n) числа разбиений, являющихся выпуклыми комбинациями трех и более разбиений. Представляются результаты вычислений и формулируются новые проблемы, к которым приводят полученные данные о числах вершин и опорных вершин политопов разбиений чисел
Myocardial remodeling and fibroblast growth factor in patients with resistant hypertension
Aim. To study the prevalence and severity of left ventricular hypertrophy (LVH), its relationship with fibroblast growth factor (FGF23) in patients with resistant hypertension (RH) depending on the effectiveness of multiagent antihypertensive therapy.Material and methods. The study included 92 patients diagnosed with RH. All patients underwent 24-hour ambulatory blood pressure monitoring (ABPM), echocardiography, general laboratory tests, and the serum FGF23 level was determined.Results. According to ABPM results, patients were divided into following groups: 1st — controlled RH (n=44) and 2nd — uncontrolled (n=48) RH. The groups were comparable in sex, age, main clinical and anthropometric parameters. In group 2, the main parameters of ABPM were higher. There were no differences in general laboratory tests, In the group of uncontrolled RH, the level of FGF23 was higher — 11,7 [8,5; 15,4] pmol/ml vs 9,2 [7,1; 11,6] pmol/ml in the 1st group (p=0,0036). According to echocardiography, a comparable violation of left ventricular (LV) diastolic function, an increase in left atrial size, LV mass (LVM) and LVM index were found. In patients of the 2nd group, large values of interventricular septal thickness were revealed — 1,3 [1,2; 1,4] cm vs 1,2 [1,1; 1,3] cm in the 1st group (p=0, 0043) and relative LV wall thickness (LVWT) — 0,50 [0,48; 0,53] vs, 0,45 [0,43; 0,50] in the 1st group (p<0,0001). In the 1st and 2nd groups, concentric LVH was more common (18 (41%) patients in the 1st and 26 (54,1%) in the 2nd (p=0,044) groups) than eccentric LVH (15 (34,1%) and 13 (27,1%) patients in the 1st and 2nd groups, respectively). Correlation analysis revealed a positive relationship between pulse pressure and HTN duration (r=48, p=0,02) and FGF23 level (r=0,62, p=0,004). The LVM index was positively associated with the diastolic pressure-time index (BP) (r=51, p=0,02). A positive correlation was found between relative LVWT and pulse pressure (r=0,64, p=0,02) and a negative relationship with the duration of regular antihypertensive therapy (r=47, p=0,04), A strong relationship was found between LVEF and FGF23 levels (r=0,75, p=0,005).Conclusion. For patients with uncontrolled resistant hypertension, an increase in pulse pressure and myocardial remodeling in the form of concentric hypertrophy are more characteristic. FGF23 is significantly higher in uncontrolled RH and is positively associated with pulse pressure and relative LVWT
Studies of cracking behavior in melt-processed YBCO bulk superconductors
An important phenomenon in bulk superconductors fabricated by top-seeded-melt growth (TSMG) is the formation of cracks due to the inherent brittleness of the YBa2Cu3O7-δ (Y-123) phase matrix. These form during the fabrication of the superconducting monolith and play an important role in the limitation of current flow. However, cracks may also form during cooling cycles of the sample to liquid nitrogen temperatures. In this investigation, macrocracks along the c-direction, in particular were analyzed microscopically before and after cooling. In addition we attempt to resolve the c-axis macrocrack formation pattern using the magnetoscan technique
The level of VEGF-A in the lacrimal fluid of diabetic retinopathy
The lacrimal fluid was investigated in 56 people (95 eyes) with type II diabetes, of which 11 (11 eyes) with no signs of diabetic retinopathy and 45 patients (84 eyes) suffering from diabetic retinopathy of varying severity. Investigation of VEGF-A (vascular endothelial growth factor A) in stimulated lacrimal fluid revealed its level in all patients. It was significantly higher in patients with diabetic retinopathy compared with data that have been obtained in patients with diabetes, but without signs of diabetic retinopathy. Statistically significant differences in the level of VEGF-A in patients with non-proliferative and proliferative retinopathy of 1-3 stages have not been identified. At the same time in patients with far-advanced retinopathy with marked variations of fatal retina and vitreous body (detachment expressed gliosis), but without evidence of neovascularization of the anterior eye, a significant decrease in the level of vasoproliferative factors has revealed
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