Estimation of laser-Doppler anemometry measuring volume displacement in cylindrical pipe flow

Laser-Doppler anemometry application in measurements of the 3-D swirl turbulent flow velocity in the cylindrical pipe, behind the axial fan, have been analysed. This paper presents a brief overview of uncertainty sources in the laser-Doppler anemometry measurements. Special attention is paid to estimation of laser-Doppler anemometry measuring volume positioning in cylindrical pipe flow due to optical aberrations, caused by the pipe wall curvature. The hypothesis, that in the central part of the pipe (r/R < 0.6) exists a small, or negligible pipe wall influence on laser- -Doppler anemometry measuring position, is investigate. The required corrections, for measurements of axial, tangential, and radial velocity components such: shift of measuring volume and its orientation are analyzed and determined for used test rig and for some other pipe geometries. [Projekat Ministarstva nauke Republike Srbije, br. TR 35046

Thermal relaxation of magnetic clusters in amorphous Hf_{57}Fe_{43} alloy

The magnetization processes in binary magnetic/nonmagnetic amorphous alloy Hf_{57}Fe_{43} are investigated by the detailed measurements of magnetic hysteresis loops, temperature dependence of magnetization, relaxation of magnetization and magnetic ac susceptibility, including a nonlinear term. Blocking of magnetic moments at lower temperatures is accompanied with the slow relaxation of magnetization and magnetic hysteresis loops. All of the observed properties are explained with the superparamagnetic behaviour of the single domain magnetic clusters inside the nonmagnetic host, their blocking by the anisotropy barriers and thermal fluctuation over the barriers accompanied by relaxation of magnetization. From magnetic viscosity analysis based on thermal relaxation over the anisotropy barriers it is found out that magnetic clusters occupy the characteristic volume from 25 up to 200 nm3 . The validity of the superparamagnetic model of Hf_{57}Fe_{43} is based on the concentration of iron in the Hf_{100-x}Fe_{43} system that is just below the threshold for the long range magnetic ordering. This work throws more light on magnetic behaviour of other amorphous alloys, too

Risk of malignancy index in the differential diagnosis of ovarian cancer in premenopausal and postmenopausal women

Uvod Karcinomi jajnika su vodeći uzrok smrtnosti u grupi ginekoloških maligniteta, stoga je karcinom jajnika najizučavanije polje u ginekološkoj onkologiji. Uzrok visoke stope smrtnosti od karcinom jajnika jeste njegova asimptomatičnost i nedovoljna efikasnost dijagnostičkih metoda, usled čega se u više od 70% slučajeva dijagnostikuje u uznapredovalom stadijumu bolesti. Rano dijagnostikovanje ovarijalnih neoplazmi je od izuzetnog značaja, kako bi se optimizovali načini lečenja, smanjili troškovi a pacijentkinje uputile u odgovarajuće onkološke centre. Napredak u cilju bolje diferencijacije benignih od malignih tumora jajnika, napravljen je razvijanjem indeksa malignosti (RMI) koji kombinuje kliničke, ultrazvučne nalaze i koncentracije tumor markera CA 125 u serumu. Drugi značajan predikcioni test predstavlja ROMA indeks koji uzima u obzir koncentracije CA 125 i HE4 u serumu, zajedno sa menopauzalnim statusom. Iako su RMI i ROMA pouzdane metode koje mogu da pomognu u preoperativnom razlikovanju pacijentkinja sa adneksalnim masama, neophodna je dalja validacija ovih metoda. Cilj istraživanja Utvrditi validnost RMI u diferencijalnoj dijagnozi benignih od malignih tumora jajnika kod pacijentkinja u premenopauzi i postmenopauzi, kao i validnost pojedinačnih komponenti predikcionih testova (RMI i ROMA) u zavisnosti od menopauzalnog statusa pacijentkinja. Metodologija Itraživanja u okviru ove doktorske disertacije obavljena su po tipu studije preseka u Ginekološko akušerskoj klinici „Narodni front“ u periodu jul – decembar 2015. godine. U studiju su uključene 153 pacijentkinje koje su bile podvrgnute operativnom lečenju (laparotomija, laparoskopija) tumora adneksalnih masa. Svim pacijentkinjama preoperativno je urađen transvaginalni ultrasonografski pregled i određene su koncentracije CA 125 i HE 4 u serumu i izračunavani su RMI i ROMA...Ovarian cancers are the leading cause of mortality in the group of gynecological cancers, and because of that ovarian cancer is the most widely studied field in gynecological oncology. The lack of sympthoms and low efficiency of diagnostic methods, are main reasons for high rate of morthality, because more than 70% of women with ovarian cancer are diagnosed at advanced stages of disease. Early diagnosis of ovarian cancer is extremely important in order to optimize treatments, reduce the cost of treatment, and to refere the patient to appropriate oncology centers. Progress in finding better approach in differentiation between benign and malignant ovarian tumors, resulted in developing the risk of malignancy index (RMI), which combines clinical, ultrasound findings and the value of the tumor marker CA 125. Other significant predictive test represents ROMA index that takes into account the concentrations of CA 125 and HE4 in serum, together with the menopausal status. Although the RMI and ROMA are reliable methods helping in preoperative discrimination of patients with adnexal masses, further validation of these methods still need to be assessed. The aim of the research To determine the validity of the RMI in the differential diagnosis of benign and malignant ovarian tumors in premenopausal and postmenopausal patients, and validite each of the individual components of predictive tests (RMI and ROMA) depending on menopausal status of the patients. Methods The study for this doctoral thesis was conducted in the Clinic for Gynecology and Obstetrics “Narodni front”, Belgrade, Serbia, during the last six months of 2015. The study group included 153 adult patients who had undergone surgery (laparatomy, laparascopy) for adnexal tumours. All patients included in this study were preoperatively underwent detailed ultrasonographic examination and have determined concentration of serum CA 125 and HE4, and RMI and ROMA were calculated..

Imaging in percutaneous ablation for atrial fibrillation

Percutaneous ablation for electrical disconnection of the arrhythmogenic foci using various forms of energy has become a well-established technique for treating atrial fibrillation (AF). Success rate in preventing recurrence of AF episodes is high although associated with a significant incidence of pulmonary vein (PV) stenosis and other rare complications. Clinical workup of AF patients includes imaging before and after ablative treatment using different noninvasive and invasive techniques such as conventional angiography, transoesophageal and intracardiac echocardiography, computed tomography (CT) and magnetic resonance imaging (MRI), which offer different information with variable diagnostic accuracy. Evaluation before percutaneous ablation involves assessment of PVs (PV pattern, branching pattern, orientation and ostial size) to facilitate position and size of catheters and reduce procedure time as well as examining the left atrium (presence of thrombi, dimensions and volumes). Imaging after the percutaneous ablation is important for assessment of overall success of the procedure and revealing potential complications. Therefore, imaging methods enable depiction of PVs and the anatomy of surrounding structures essential for preprocedural management and early detection of PV stenosis and other ablation-related procedures, as well as long-term follow-up of these patients

Determination of air and hydrofoil pressure coefficient by laser doppler anemometry

Some results of experiments performed in water cavitation tunnel are presented. Pressure coefficient (Cp) was experimentally determined by Laser Doppler Anemometry (LDA) measurements. Two models were tested: model of airplane G4 (Super Galeb) and hydrofoil of high speed axial pump. These models are not prepared for conventional pressure measurements, so that LDA is applied for Cp determination. Numerical results were obtained using a code for average Navier-Stokes equations solutions. Comparisons between computational and experimental results prove the effectiveness of the LDA. The advantages and disadvantages of LDA application are discussed. Flow visualization was made by air bubbles

Chemical composition and screening of the antimicrobial and antioxidative activity of extracts of Stachys species

GC and GC/MS analyses of the diethyl ether and ethyl acetate extracts obtained from the aerial parts of Stachys germanica subsp. heldreichii (Boiss) Hayek, Stachys iva Griseb., Stachys plumosa Griseb. and Stachys scardica Griseb., Balkan peninsula endemics, were performed. One hundred and seventy-nine constituents, accounting for 88.8–98.1% of the total composition of the extracts, were identified. The common feature of the diethyl ether extracts was the high content of terpenoids and fatty acid-derived compounds, while the common feature of the ethyl acetate extracts was the prevalence of fatty acid-derived compounds. A disk diffusion method was used for the evaluation of the antimicrobial activities of the extracts against a panel of microorganisms (bacteria: Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Salmonella enteritidis; fungi: Aspergillus niger and Candida albicans). The total antioxidant capacity of the extracts was evaluated by the phosphomolybdenum method. The preliminary bioassay results indicated that the diethyl ether extract of S. plumosa could be a possible source of antioxidant and antimicrobial compounds

IR thermography in moisture and earthquake damage detection performed in the Žiča monastery, Serbia

This paper presents the results of the IR thermographic diagnostics of the seismic damage inflicted upon the Žiča Monastery after the earthquake on 3rd November 2010. The Žiča Monastery founded in 13th century is located in central Serbia. The moisture content in the structure was detected too. The obtained results document the current state of the buildings and, at the same time, confirm the advantages of IR thermography as a method in the diagnosis of earthquake cracks, useful for the seismic retrofit study. The obtained results enable the identification of the structure parts where more in-depth investigations need to be concentrated. The procedures and activities for curative conservation and protection of the Žiča Monastery should include the thermographic test results. The results and the conclusions obtained in this case study could be used as example for further extensive studies of historical and cultural heritage buildings

Torrential floods and town and country planning in Serbia

Torrential floods are the most frequent natural catastrophic events in Serbia, causing the loss of human lives and huge material damage, both in urban and rural areas. The analysis of the intra-annual distribution of maximal discharges aided in noticing that torrential floods have a seasonal character. The erosion and torrent control works (ETCWs) in Serbia began at the end of the 19th century. Effective protection from torrential floods encompasses biotechnical works on the slopes in the watershed and technical works on the torrent beds, within a precisely defined administrative and spatial framework in order to achieve maximal safety for people and their property. Cooperation to overcome the conflicts between the sectors of the water resources management, forestry, agriculture, energetics, environmental protection and local economic development groups is indispensable at the following levels: policy, spatial planning, practice, investments and education. The lowest and most effective level is through the Plans for Announcement of Erosive Regions (PAERs) and the Plans for Protection from Torrential Floods (PPTFs), with Hazard Zones (HZs) and Threatened Areas (TAs) mapping on the basis of the hydrologic, hydraulic and spatial analysis of the factors that are important for the formation of torrential floods. Solutions defined through PAERs and PPTFs have to be integrated into Spatial Plans at local and regional levels

Numeričke simulacije širenja štetnih gasova i čestica emitovanih iz Železare u Smederevu

This paper presents the results obtained by numerical simulation, of air pollution dispersion from the stacks of steel plant in the direction of Smederevo fortress. Trajectories and concentrations of pollutants (particulate matters, CO and NO2) were determined by commercial software ANSYS FLUENT. The relief of the terrain was included in the geometry of the numerical domain (11400x3600x100 m). An unstructured mesh composed of more than three million cells was generated. Southeast wind speed was 2.9 m/s blowing in the direction parallel to the longest side of the domain. Atmospheric conditions correspond to conversion, i.e. increase in temperature with height. The sources of pollution included in the simulation are central agglomeration stack, blast fumaces stack and central stack of steel-making. Obtained results represent the first step in a complex, multidisciplinary research of the industrial zones impact on cultural heritage objects.U radu su prikazani rezultati širenja štetnih materija u vazduhu, emitovanih iz dimnjaka Železare u pravcu Smederevske tvrđave, dobijeni numeričkom simulacijom. Putanje i koncentracija polutanata (čestica, CO i NO2) su simulirane komercijalnim softverskim paketom ANSYS FLUENT. Reljef terena je uključen u geometriju numeričkog domena, čije su dimenzije 11400x3600x100 m. Generisana je nestruktuisana mreža sa više od tri miliona ćelija. Numerička simulacija je vršena za jugoistočni vetar (paralelan dužoj stranici domena) brzine 2.9 m/s. Atmosferski uslovi odgovaraju slučaju konverzije, temperatura raste sa visinom. Izvori zagađenja su centralni dimnjak aglomeracije, dimnjak visoke peći i centralni dimnjak čeličane. Dobijeni rezultati su samo prvi korak kompleksnog, multidisciplinarnog istraživanja uticaja industrijskih zona na objekte kulturne baštine