The flora of the volcanic island of Brusnik (central Dalmatia, Croatia)

Research into the vascular flora of the volcanic island of Brusnik was carried out in the period from 2000 to 2002. A total of 28 higher plant species was found, four of them being noted for the first time. Of the 41 taxa noted by previous authors, 24 were confirmed, but 17 were not. According to analysis of life forms, the most numerous are Therophyta (13 species, 46.4%), followed by Chamaephyta (seven species, 25%), Phanerophyta (four species, 14.3%), Hemicryptophyta (three species, 10.7%) and Geophyta (one species, 3.6%). After analysis of floral elements, autochthonous taxa are grouped into three categories: Mediterranean floral element (18 species, 66.6%), South European floral element (five species, 18.5%) and widespread plants (four species, 14.8%). Especially important plants in the flora of Brusnik are Frankenia pulverulenta L., a very rare species in the Croatian flora and the Illyrian-Adriatic endemic plants Centaurea ragusina L., Limonium vestitum (Salmon) Salmon subsp. brusnicense Trinajsti} and Senecio leucanthemifolius Poir. var. reichenbachii Fiori. The results of our research show that the island of Brusnik belongs, in phytogeographical terms, to the Mediterranean zone proper of the Mediterranean region

Zlatibor knitters in the socialist Yugoslavia media discourse

In the first half of the 1970s, a beautiful, young, modern and well-groomed urban woman was the dominant figure in the media discourse of the Yugoslav women’s magazine “Bazar”. The characters of rural women appeared only sporadically. One of the few were Zlatibor knitters — rural women employed in the fashion production Sirogojno Style, which in the second half of the last century created a recognizable identity in the domestic and foreign fashion market. The aim of this paper is to compare the way in which the major and minor female characters were presented in the media discourse of the mentioned women’s magazine and to provide an answer to the question of whether (and to what extent) their media images are compatible. In terms of methodology, the paper relies on the analysis of textual and visual messages published in issues 129–285 of the women’s magazine “Bazar”

The supramolecular arrangement in the Ni(II) complexes of isothiosemicarbazide

The molecules of two complexes [Ni(ITSC)2(H2O)2](tere)·2H2O and [Ni(ITSC)2(NO3)2] (ITSC = S-methylisothiosemicarbazide; tere = terephthalate) tend to associate trough the hydrogen bonding interactions into the characteristic 2D blocks separated by the S-methyl moieties. The different coordination mode of the isothiosemicarbazide comparing to thiosemicarbazide (TSC) prevents the formation of the complementary hydrogen bonds with dicarboxylate important for selfassambly of TSC complexes, however in these ITSC the terephthalate anion has role in connection of the blocks and transformation of the 2D into the 3D supramolecular structure. The similar crystal arrangement is found in two earlier reported complexes of Ni(II) with ITSC.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Study of C−H⋅⋅⋅π interactions with pyrrole and chelate rings in metal-porphyrin complexes

The Cambridge Structural Database (CSD) was screened in order to find and investigate specific C−H⋅⋅⋅π interactions between C−H groups and two types of rings with delocalized π-bonds that exist in porphyrin: pyrrole and six-membered chelate. Statistical analysis of geometrical parameters for interactions in both types of rings was done. In order to determine preferred positions in porphyrinato ring for C−H⋅⋅⋅π interactions fifteen different points distributed over porphyrin ring have been chosen and each of them have been analyzed. Calculations of these interactions by density functional theory (DFT) have been done on three different model systems.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Experimental and numerical investigation of flow around a sphere with dimples for various flow regimes

Flow over a sphere is a typical bluff-body flow with many engineering applications. However, it has not been studied in depth, as compared to flow over a circular cylinder, because of the difficulties in the experimental set-up as well as in the computational approach for studying flow over a sphere. The main challenges are to understand the flow hydrodynamics and to clarify the flow pattern around a dimpled sphere because the flow pattern complying with the dimple structure on its surface is very complicated. In this paper experimental and numerical investigations of the fluid flow around a sphere with dimples, are represented. The sphere with dimples is placed in a quadratic cross section duct (measuring section) and numerical simulation results are obtained by solving RANS equations. Furthermore, experimental measurements are carried out using a Laser-Doppler Anemometer (LDA). Experimental and numerical results of flow velocity fields were compared for three different flow regimes (Re=8×103, 2×104 and 4×104). Numerical investigation was performed for wide range of Reynolds numbers (Re=270%106). The final purpose of this paper is experimental and numerical determination of velocity field, separation point, pressure and drag coefficient, the length of reverse flow region in the wake and RANS turbulent model which gives the best results for engineering practice

Determination of averaged axisymmetric flow in hydraulic turbomachinery runner

The first chapter of the paper is introductory unfolding, where the task of hydrodynamic calculation is presented, as well as the schema of flow in the flow-through part of turbomachine. It also outlines an overview of recent results in this field, limited to the most significant results, as well as those who have paved the way to some new methods of study and recalculation of the hydraulic turbomachinery and low pressure fans. The main task of the turbomachinery hydrodynamic calculation (the design of flow components that provide the required operated parameters, and at the same time achieving its maximum energy efficiency), is a very complex task which requires a unified application of theoretical and experimental research results. In order to achieve practically applicable methodology for the turbomschinery calculation, the simplification of the fluid flow and fluid characteristics is performed: physical flow is simplified as two-dimensional, in some cases even one-dimensional flow, the turbomachinery operates in a steady operating regime, when the flow can be considered invariant with time, and the fluid in hydraulic turbomachinery and low pressure fans can be regarded as incompressible. The basic assumption is that the flow in turbomachinery runners and its stationary parts are axisymmetric, although realistically it is not the case. Also, in the introductory chapter, the basics of determining the shape of the hydraulic turbomachinery blades are represented. At the end of this chapter, the application, development and significance of the numerical simulation of fluid flow regarding turbomachinery design and testing, with emphasis on the most significant achievements in this field and its application to the turbomachinery performance, is showed. In the second chapter of the doctoral thesis a brief overview of the methodology of numerical simulation of flow, turbulence modeling and application a possibility of CFD (Computational Fluid Dynamics) methods to flow in turbomachinery is given. Especially the numerical simulation of flow in hydraulic turbomachinery and low pressure fans runners, but also in the fixed vane and vaneless stationary parts of turbomachinery, is considered. Due to the simple application, but also the required computing resources for the purpose of ix numerical flow simulation, the focus was on solving the Reynolds-averaged equations (i.e. RANS equations). The basic equations of fluid flow (partial differential equation) are given, which are, in the process of the temporal and spatial discretization, transformed into a system of algebraic equations, suitable for numerical implementation. The system of equations is closed by using any of the existing models of turbulent flow (i.e. turbulence models), what was also discussed in this chapter. In the last part of this chapter the principles of numerical solving of fluid flow are given (beginning with discretization, difference schemes, the generation of the computational grid, and ending with the convergence criterion of the obtained solution). Examples of numerical simulations obtained by using commercial software Ansys Flow Dynamics, which consists of turbomachinery module and validation of numerical models, are the subjects of the third chapter. The examples of numerical simulations of different turbomachines are presented, in following order: I) low pressure reversible axial flow fan with plane runner blades, II) axial-flow propeler pump and III) centrifugal pump. For all cases, the physical model is first presented, and then a numerical model is created, while the results of numerical simulations are given as the display of operating parameters obtained for a defined number of revolutions. The operated parameters of each presented turbo machine obtained by numerical simulations of the flow in the range of operating flow rate, compared with the operating characteristics obtained by experimental tests of appropriate machines under laboratory conditions, therefore performing the validation of the model. When it comes to turbomachinery, with respect to their practical application, it can be considered that the model validation is performed if the relative error of operating parameters in all current regimes does not exceed 5%. The flow parameters in different discrete points of the turbomachinery runner, i.e. in different cross-sections of the runner (position, pressure, and velocity) of all presented examples, which are used for the purpose of averaging, were presented in the form of tables given in the Appendix of this dissertation. The fourth chapter deals with the determination of averaged axisymmetric flow surface according to the results obtained by numerical simulation of flow in hydraulic turbines and low pressure fans. The real flow in the profile cascades of hydraulic turbomachinery and fans is not axially symmetric, and the can be reduced to axisymmetric flow fictively, if the flow parameters in the blade channels are averaged according to a circular coordinate. Values of x flow parameters at discrete points of the considered flow field are obtained by numerical simulations. According to the results of numerical simulations of flow in turbomachinery runner, it is possible to determine the averaged flow parameters accordint to the circular coordinate, and then to determinate the averaged axisymmetric flow surfaces. The methodology of averaging flow parameters according to the circular coordinate and obtained equations are presented in this chapter. The results of determining the meridional flow streamlines of the averaged fluid flow using the integral equations of continuity, for the cases presented in the chapter 3, are presented in the fifth chapter. Guided by the theory and the equations given in section 4, the results of determination of averaged streamlines in hydraulic turbomachinery and low pressure fans runner, respectively averaged axisymmetric flow surface. In addition, the specific works of elementary stages on averaged axisymmetric flow surfaces in the turbomachinery runner are determined, as well as torque and power of the runner. Finally, the calculation of flow rates of the averaged mechanical flow energy through axisymmetric flow control surfaces, at the entrance and exit of the work area of the runner, is performed, leading to the significant information on the fluid energy losses in the turbomachinery runner. At the end of the dissertation the Conclusion is presented, and in the Appendix tables the averaged values of flow parameters in the corresponding sections of the turbomachinery runners are presented. The results of averaging according to the circular coordinate, as defined in section 4, are presented, and these results are used in section 5

Metastability – Markovian approach

A complete system of events of nonlinear processes in complex dynamical systems describes the evolution of the distribution. Different stages of evolution of the distribution declared stable, metastable and unstable systems. Variance of probabilistic distribution plays a crucial role in determining the state of the system. It was found that the system is metastable, when it carried Markovian processes in continuous time. Metastability is the original metallurgical phenomenon and actively exists in the structure of the materials. In a metastable state, the structural distances in material are exponentially distributed

3-Anilino-1-ferrocenylpropan-1-one

In the title ferrocene derivative, [Fe(C5H5)(C14H14NO)], the dihedral angle between the mean planes of the phenyl ring and the substituted cyclo­penta­dienyl ring is 84.4 (1)°. The mol­ecules are connected into centrosymmetric dimers via N—H⋯O hydrogen bonds. In addition, C—H⋯O and C—H⋯N contacts stabilize the crystal packing

Znanje i stavovi beogradskih studenata medicine i stomatologije o upravljanju medicinskim otpadom

Introduction/Objective Knowledge and practical skills in medical waste (MW) management are of equal importance for medical and dental doctors. The first comparative study on the knowledge and skills in the field of MW management among Belgrade students was conducted with the goal of examining whether students of medicine and dentistry are equally familiar with this extremely important field. Methods a cross-sectional study included 558 students of the sixth year of studies (430 medical and 128 dental students) who completed an anonymous semi-structured questionnaire to determine attitudes and knowledge on MW management. Results the majority of medical and dental students had no training in MW management (79.5% and 74.6%, respectively). Dental students use protective equipment more frequently than medical students (94.5% vs. 42%, p lt 0.001). However, full vaccinal protection against hepatitis B is better among medical students compared to dental students (57.7% vs. 39.1%, p lt 0.001). Complete knowledge on postexposal prophylaxis is better among medical students compared to dental students (44.5% vs. 13.3%, p lt 0.001). However, dental students are more disciplined in reporting injuries (63.1% vs. 52.4%, p = 0.038). The students' knowledge on primary separation of infectious waste (93% vs. 77.8%, p lt 0.001) and used needles (80.3% vs. 70.4%, p = 0.007) is better among dental students compared to medical students' correct answers. Conclusion Dental students show better knowledge on MW management and are more disciplined in using personal infection protection compared to medical students. The students support continued training on MW management and investigations on this topic.Uvod/Cilj Znanje i praktične veštine upravljanja medicinskim otpadom su od posebnog značaja za doktore medicine i stomatologije. Komparativna studija o znanju i veštinama iz oblasti upravljanja medicinskim otpadom sprovedena je među beogradskim studentima prvi put, u cilju ispitivanja da li ovom izuzetno važnom oblašću studenti medicine i stomatologije vladaju podjednako dobro. Metode Ova studija preseka obuhvatila je 558 studenata šeste godine studija na Beogradskom univerzitetu (430 studenata medicine i 128 studenata stomatologije), koji su popunili anonimni upitnik o znanju i stavovima o upravljanju medicinskim otpadom. Rezultati Većina studenata stomatologije i medicine nisu imali nikakvu posebnu obuku iz upravljanja medicinskim otpadom (79,5% i 74,6%). Studenti stomatologije su češće koristili zaštitnu opremu (94,5% prema 42%, p lt 0,001). Vakcinalna zaštita od hepatitisa B je kompletnija među studentima medicine u odnosu na studente stomatologije (57,7% prema 39,1%, p lt 0,001). Znanje o profilaksi posle izloženosti bolja je među studentima medicine (44,5% prema 13,3%, p lt 0,001). Međutim, studenti stomatologije su ažurniji u pogledu prijavljivanja povreda na radnom mestu (63,1% prema 52,4%, p = 0,038). Znanje studenata o primarnoj separaciji infektivnog otpada i korišćenih igala je bolje među budućim stomatolozima (tačni odgovori 93% nasuprot 77,8%; p lt 0,001 i 80,3% prema 70,4%; p = 0,007). Zaključak Studenti stomatologije imaju bolje znanje o upravljanju medicinskim otpadom i disciplinovaniji su u pogledu korišćenja zaštitne opreme na radu u odnosu na studente medicine. Studenti podržavaju kontinuiranu edukaciju o upravljanju medicinskim otpadom i dalja istraživanja o ovoj temi