Investigations of the Structure of the Diurnal Variations of Geomagnetic Field

Changes in solar activity mechanisms generate changes in geomagnetic activity. The structure of geomagnetic activity can be illustrated by classes of the periodic and non-periodic variations of geomagnetic field. This study shows the results of the analysis of the periodic and non-periodic diurnal variations in the geomagnetic field (variations Sq, Sd,) and disturbances of geomagnetic activity (variations of indices Ri, Kp). The analysis was carried out during the months in which extreme solar and geomagnetic storms were recorded, October 2003 and November 2004. An analysis the structure and morphology of diurnal variations was made on the basis of the recorded geomagnetic data (the mean hourly values of geomagnetic field, three-hour indices of geomagnetic activity), at the Geomagnetic Observatory Grocka (GCK) (Serbia).

Surface spin flip probability of mesoscopic Ag wires

Spin relaxation in mesoscopic Ag wires in the diffusive transport regime is studied via nonlocal spin valve and Hanle effect measurements performed on permalloy/Ag lateral spin valves. The ratio between momentum and spin relaxation times is not constant at low temperatures. This can be explained with the Elliott-Yafet spin relaxation mechanism by considering the momentum surface relaxation time as being temperature dependent. We present a model to separately determine spin flip probabilities for phonon, impurity and surface scattering and find that the spin flip probability is highest for surface scattering.Comment: 5 pages, 4 figure

Evidence of Vortex Jamming in Abrikosov Vortex Flux Flow Regime

We report on dynamics of non-local Abrikosov vortex flow in mesoscopic superconducting Nb channels. Magnetic field dependence of the non-local voltage induced by the flux flow shows that vortices form ordered vortex chains. Voltage asymmetry (rectification) with respect to the direction of vortex flow is evidence that vortex jamming strongly moderates vortex dynamics in mesoscopic geometries. The findings can be applied to superconducting devices exploiting vortex dynamics and vortex manipulation, including superconducting wires with engineered pinning centers.Comment: 5 pages, 3 figure

Predictive value of transvaginal ultrasound in predicting histopathologic endometrium in perimenopausal women

Rezime: Cilj ovog istraživanja je bio da se proceni tačnost transvaginalnog ultrazvuka u otkrivanju maligniteta na endometrijumu kod perimenopauzalnih žena. Materijal i metode: U prospektivnoj studiji učestvovalo je 100 pacijentkinja u perimenopauzi kod kojih je otkrivena neka promena na endometrijumu ultrazvučnim pregledom ili su bile upućene na Ginekološko akušersku kliniku Narodni front u Beogradu u period od 1. septembra 2012.godine. Transvaginalnim ultrazvukom pregledana je svaka pacijentkinja uključena u istraživanje. Parametri ultrazvučnog pregleda sačinjavali su ultrazvučni skor. Rezultat: Rezultat dobijen regresionom analizom pokazuje da ovaj transvaginalni ultrazvučni skor ima prognostički značaj u otkrivanju maligniteta endometrijuma. Vrednost skora 8 pokazuje najbolju validnost u detekciji endometrijalnog maligniteta sa senzitivnošću 0,857 i specifičnošću 0,785. Zaključak: Prikupljene vrednosti transvaginalnog ultrazvučnog pregleda pokazuju veliku prediktivnu vrednost u otkivanju malignih promena na endometrijumu.Summary: Purpose: The aim of this study was to assess the accuracy of transvaginal ultrasound in detecting endometrial malignancy in perimenopausal women. Material and methode: The cross-sectional study included 100 perimenopausal women who had changes on the edometrium discovered through a regular ultrasound check-up and were referred to Clinic of Gynecology and Obstetrics "Narodni Front" in Belgrade during the period from September 1, 2012 to September 1, 2013. Transvaginal ultrasound has been performed on each participant in the study. Parameters of the ultrasound examination composed a score system. Result: The results of regression analysis have shown that this transvaginal ultrasound score have independent prognostic value for detection of endometrial malignancy. Score system showed that the value 8 had the best validity for the detection of endometrial malignity with the sensitivity of 0.857 and specificity of 0.785. Conclusion: The collected transavginal ultrasound sample had high predictive value for the discovery of malign changes on endometrium

Methodological foundations of a modern textbook of the Russian lannguage for professionals ( in higher education for turismology and economics)

Дисертација представља покушај комплексне и системске разраде концепта савременог когнитивно-комуникативног уџбеника руског језика високошколског туризмолошког профила у српској говорној и социокултурној средини. Цео процес истраживања у спољашњем обухвату је постављен на тродимензионалном нивоу и плану посматрања међусобно условљаваних појава, тј. саодноса друштвених потреба, наставног процеса и концепта савременог уџбеника струке. Из те комплементарности разраста аспект интердисциплинарног приступа у сферу лингвистичке и туризмолошке науке. Додири ових двеју сфера у више тачака укрштања артикулишу комуникативну функцију језика, која са своје стране опредмећује језик струке. Управо тај комуникативни аспект језика, као стожер нашег истраживања, одређује постављање методолошких основа наставе руског језика на Високој школи за туризам. Они се, пак, манифестују кроз одређене циљеве у наставном процесу, методске концепције и принципе наставе, садржај наставе, избор наставног материјала, методе у настави. Примењујући их и анализирајући у виду општих начела, долазимо кроз сам наставни процес, који је уједно и наш експеримент, до извесних резултата. То значи да, на основу примарне анализе уз помоћ традиционалне руско-српске лингвистичке литературе, наставних и образовних програма и стандарда и уз помоћ наведених извора, реализујемо савремени методолошки приступ концепцији уџбеника руског језика високошколске туризмолошке струке. Он своје оправдање налази у теоријском објашњењу настанка и формирања аспектних говорних навика и комуникативних умења, који и јесу теоријски и практични саставни део самог наставног процеса. На тај начин се доводе у везу методолошки основи наставног процеса руског језика на Високој школи за туризам и методолошки основи концепције савременог уџбеника високошколског туризмолошког профила. Методолошки основи засебно, као и у својој корелацији јесу утемељени на лингвистичким основама научног стила руског језика, што тај међуоднос чини још оправданијим.The dissertation is an attempt to develop a complex system and the concept of modern cognitive-communicative textbooks of the Russian Language for students of higher education in tourismology in the Serbian speaking and socio-cultural environment. The whole research process in the external scope is based on a three-dimensional level and the observation plan on each mutually conditioned phenomena, ie interrelations and correlations between social needs, teaching process and the concept of a modern professional textbook. This aspect of complementarity brings about the interdisciplinary approach in the sphere of linguistics and tousrimology. Touches of these two spheres in multipoint crosses articulate the communicative function of language, which in turn reifies the professional language. It is this communicative aspect of the language, as the pillar of our research, which determines the methodological foundations of teaching the Russian language at the College for Tourism. They are, in turn, manifested through specific goals in the teaching process, methodological concepts and principles of teaching, the content of the curriculum, the selection of teaching materials, teaching methods. Analyzing and applying them in the form of general principles, we come from the teaching process itself, which is at the same time our experiment, to certain results. This means that, based on the primary analysis using the traditional Russian-Serbian linguistic literature, teaching curricula and standards, and with the help of these sources we implement modern methodological approach to the textbooks of Russian for higher levels of tourismology education. It finds its justification in the theoretical explanation of the origin and formation of aspect-speech habits and communication skills, which are theoretical and practical part of the education process itself. Thus the methodological basis of teaching the Russian language at the College of Tourism and methodological basis of the concept of a modern textbook for students of tourism at higher education level are associated. Methodological grounds alone, as well as in their correlation, are based on linguistic grounds of scientific style of the Russian Language, thus making this interrelationship even more justified