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

Diagnostic validity of different tests in pediatric gastroesophageal reflux disease

Dijagnoza gastroezofagealne refluksne bolesti B , zasnovana na simptomima, nije specifična zbog visoke prevalencije poremećaja koji mogu da oponašaju B. Najčešće korišćene dijagnostičke metode kod dece su pH monitoring, kombinovani pH-MII (multikanalna intraluminalna impedansa) monitoring i endoskopija. Kombinovani pH-MII monitoring je najtačniji dijagnostički metod za otkrivanje GERB-a kod dece, sa tendencijom da postane zlatni standard. Cilj ove studije bio je da uporedi različite dijagnostičke metode za otkrivanje GERB-a kod dece i odredi njihovu validnost. Takođe, cilj nam je bio da ispitamo razlike u kliničkim i pH-MII parametrima između dobnih grupa, kao i prediktivni značaj parametara pH-MII monitoringa u proceni prisustva erozivne refluksne bolesti. Materijal i metode: U ovoj studiji preseka, retrospektivno su prikupljeni podaci o svoj deci uzrasta do 18 godina kojoj je urađen pH-MII monitoring zbog gastrointestinalnih i/ili ekstraezofagealnih simptoma suspektnih na GERB u Univerzitetskoj dečjoj klinici u Beogradu, u periodu od jula 2012. do decembra 2016. godine. Za četiri indeksna dijagnostička testa simptomi, pH monitoring, MII monitoring, endoskopija određeni su parametri dijagnostičke validnosti senzitivnost, specifičnost, pozitivna i negativna prediktivna vrednosti) uzimajući pH-MII monitoring za referentni test. Rezultati: Ukupno 218 dece 117 dečaka/101 devojčica , prosečnog uzrasta 6,7 godina (opseg 0,06-18,00 godina), ispunilo je kriterijume za uključivanje u studiju. Ambulatornim pH-MII monitoringom B je utvrđen kod 128 57,4% dece. Izolovanim pH monitoringom B je utvrđen kod 76 34,1% dece, dok je MII monitoringom dijagnostikovan kod 78 (35%) dece. Slabokiseli refluks je bio češći kod odojčadi p<0,01 , dok je kiseli refluks bio značajno češći kod starije dece i adolescenata (p<0,01). Senzitivnost pH-metrije je bila najniža kod odojčadi (22,9%), uz jasnu rastuću tendenciju sa uzrastom (najviša je bila kod dece ≥ 9 godina, 76,4%)..

Momentum-Resolved Electronic Structure of the High-TcT_{c} Superconductor Parent Compound BaBiO3_{3}

We investigate the band structure of BaBiO$_{3}$, an insulating parent compound of doped high-$T_{c}$ superconductors, using \emph{in situ} angle-resolved photoemission spectroscopy on thin films. The data compare favorably overall with density functional theory calculations within the local density approximation, demonstrating that electron correlations are weak. The bands exhibit Brillouin zone folding consistent with known BiO$_{6}$ breathing distortions. Though the distortions are often thought to coincide with Bi$^{3+}$/Bi$^{5+}$ charge ordering, core level spectra show that bismuth is monovalent. We further demonstrate that the bands closest to the Fermi level are primarily oxygen derived, while the bismuth $6s$ states mostly contribute to dispersive bands at deeper binding energy. The results support a model of Bi-O charge transfer in which hole pairs are localized on combinations of the O $2p$ orbitals.Comment: minor changes to text and other figures; includes link to online Supplemental Material; accepted to Phys. Rev. Let

Synthesis of BaTiO3 from a mechanically activated BaCO3-TiO2 system

In this article the solid state reaction of BaTiO3 formation from a mechanically activated BaCO3-TiO2 system has been investigated. An equimolar mixture of BaCO3 and TiO2 powders was activated in a planetary ball mill in a continual regime for 0, 30 and 90 min, pressed and thermally treated up to 1200°C. The effect of the milling and firing regime on the phase formation was investigated by the X-ray diffraction (XRD) method and differential thermal analysis (DTA). Deconvolution of the experimental DTA curve corresponding to the BaTiO3 synthesis process has been performed. The influence of the activation time on the change of characteristic temperature for each elementary step in the complete solid-state reaction of BaTiO3 formation, was analyzed. These results were correlated with the ones obtained by SEM characterization and by XRD analysis.U ovome radu je analiziran uticaj mehaničke aktivacije sistema BaCO3- TiO2 na formiranje BaTiO3. Ekvimolarne smeše praha BaCO3 i TiO2 su aktivirane u planetarnom mlinu u kontinualnom režimu tokom 0, 30 i 90 min. Uzorci su zatim presovani i termički tretirani do 1200oC. Efekat mlevenja i zagrevanja na promene faza je analiziran primenom rendgenske fazne analize i diferencijalne termijske analize. Izvršena je dekonvolucija eksperimentalno dobijene DTA krive koja odgovara procesu sinteze BaTiO3, kao i analiza uticaja vremena aktivacije na promene karakteristične temperature za svaki pojedinačni elementarni proces tokom sinteze barijum titanata. Ovi rezultati su korelisani sa rezultatima dobijenim SEM i XRD analizom

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

Supplementary data for article:Trmčić, M.; Matović, R. V.; Tovilović, G.; Ristic, B. Z.; Trajković, V. S.; Ferjančić, Z.; Saičić, R. A Novel C,D-Spirolactone Analogue of Paclitaxel: Autophagy Instead of Apoptosis as a Previously Unknown Mechanism of Cytotoxic Action for Taxoids. Organic and Biomolecular Chemistry 2012, 10 (25), 4933–4942. https://doi.org/10.1039/c2ob25514f

Supplementary material for: [https://doi.org/10.1039/c2ob25514f]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1304

Synthesis and sintering of high-temperature composites based on mechanically activated fly ash

Amount of fly ash which is and yet to be generated in the coming years highlights the necessity of developing new methods of the recycling where this waste can be reused in significant quantity. A new possibility for fly ash utilization is in high-temperature application (thermal insulators or/and refractory material products). As such, fly ash has to adequately answer the mechanical and thermal stability criteria. One of the ways of achieving it is by applying mechanical activation procedure on fly ash. In present study, fly ashes from two different power plants were mechanically activated in a planetary ball mill. Mechanically treated fly ashes were cemented with two different binders: standard Portland cement and high-aluminates cement. Physico-chemical analysis and investigation of mineralogical components of composites are emphasized, due to the changes occurred in fly ash during mechanical activation and sintering of composites. Macro-performance of the composites was correlated to the microstructure of fly ash studied by means of XRD and SEM analysis. Thermal stability of crystalline phases was investigated with DTA. Highlight was placed on determination of relationship between mechanically activated fly ash and obtained composites microstructure on one side and behavior of sintered composites on the other side. [Projekat Ministarstva nauke Republike Srbije, br. 172057, 45008 and a project F-198, financed by Serbian Academy of Sciences and Arts

The absence of immunoreactivity to donkey’s milk in patients with recurrent aphthous ulcers and immunoreactivity to cow’s milk

Despite the numerous benefits of milk constituents for human health a considerable number of the general population follow a milk-restricted diet due to clinically confirmed or self-assessed adverse reactions to cow’s milk consumption. Recurrent aphthous ulcers (RAU) are currently one of the most common oral disorders, with a worldwide distribution and insufficiently defined etiology, which, among other factors, implies the immunological reaction to food proteins. The aim of this study was to determine the immune-reactivity to donkey’s milk proteins in patients with RAU and compare it to the reactivity towards the proteins from cow’s and goat’s milks, in a set of simultaneous experiments. Levels of serum IgA, IgG and IgE antibodies to the same quantity of the examined antigens were determined by enzyme-linked immunosorbent assay. The results indicate that patients with RAU with increased immunity to cow’s milk proteins could consider the use of donkey’s milk as the best protein source

Prevalence, clinical characteristics, and predictors of peripheral arterial disease in hemodialysis patients: a cross-sectional study

BackgroundPeripheral arterial disease (PAD) is common in patients with end-stage renal disease on hemodialysis, but is frequently underdiagnosed. The risk factors for PAD are well known within the general population, but they differ somewhat in hemodialysis patients. This study aimed to determine the prevalence of PAD and its risk factors in patients on hemodialysis.MethodsThis cross-sectional study included 156 hemodialysis patients. Comorbidities and laboratory parameters were analyzed. Following clinical examinations, the ankle-brachial index was measured in all patients. PAD was diagnosed based on the clinical findings, ankle-brachial index lt 0.9, and PAD symptoms.ResultsPAD was present in 55 of 156 (35.3%; 95% CI, 27.7-42.8%) patients. The patients with PAD were significantly older (6710years vs. 62 +/- 11years, p=0.014), more likely to have diabetes mellitus (p=0.022), and anemia (p=0.042), and had significantly lower serum albumin (p=0.005), total cholesterol (p=0.024), and iron (p=0.004) levels, higher glucose (p=0.002) and C-reactive protein (p lt 0.001) levels, and lower dialysis adequacies (p=0.040) than the patients without PAD. Multivariate analysis showed higher C-reactive protein level (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.00-1.06; p=0.030), vascular access by Hickman catheter (OR, 4.66; 95% CI, 1.03-21.0; p=0.045), and symptoms of PAD (OR, 5.20; 95% CI, 2.60-10.4; p lt 0.001) as independent factors associated with PAD in hemodialysis patients.ConclusionThe prevalence of PAD was high among patients with end-stage renal disease on hemodialysis. Symptoms of PAD, higher C-reactive protein levels, and Hickman vascular access were independent predictors of PAD in patients on hemodialysis