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

Hypothyroidism as a factor of heart failure in elderly people

Uvod: Cilj ovog rada je ispitivanje povezanosti hipotireoze sa pojavom srčane insuficijencije kod osoba starije životne dobi i utvrđivanje posebnosti uticaja hipotireoze na način prezentovanja i način lečenja srčane insuficijencije kod osoba starije životne dobi. Metod: Ispitivanje je obuhvatalo 277 pacijenata životne dobi 65 godina i preko, a koji su imali dijagnostikovanu srčanu insuficijenciju. Ispitivana grupa su osobe starije životne dobi sa srčanom insuficijencijom i hipotireozom i kontrolna grupa – osobe starije životne dobi sa srčanom insuficijencijom, ali bez hipotireoze hospitalizovani na kliničkom odeljenju za gerijatriju, Kliničko bolničkog centra Zvezdara u Beogradu u periodu od 2005. Do 2010. godine. Ispitivanje je sprovedeno u skladu sa Helsinškom dekleracijom (revidirana verzija, 1983. godina), a odobrena je od strane etičkog komiteta Medicinskog fakulteta Univeziteta u Beogradu. Svi podaci su obrađeni i prikazani merama deskriptivne staristike. Za poređenje kontinuiranih numeričkih varijabli sa normalnom raspodelom korišćen je t-test., dok je poređenje učestalosti korišćen hi-kvadrat. Nivo statističke značajnosti je bio p<0,05. Rezultati: Prosečna starost u grupi ispitanika je bila 80,35+-6,31, a u kontrolnoj grupi 81,41+-6,34 godina. U grupi sa hipotireozom statistički značajno je češća bila pojava angine pektoris (p<0,001). U istoj grupi bilo je statistički više bolesnika sa predhodnom zamenom veštačke valvule (p=0,022). U ispitivanoj grupi starijih bolesnika sa srčanom insuficijencijom i hipotireozom, u odnosu na kontrolnu grupu, registruju se statistički više vrednosti serumskog ukupnog holesterola (p<0,001), LDL-holesterola (p<0,001) i triglicerida (p<0,001). U odnosu na tiroidni hormonski status, na početku studije u ispitivanoj grupi bolesnici sa SI i hipotireozom su imali signifikantno veće vrednosti serumskog TSH (p<0,001) i fT4 (p<0,048) u odnosu na kontrolnu grupu. Posle godinu dana praćenja, nije bilo više razlike u odnosu na vrednosti TSH, dok statistički značajna razlika ostaje u odnosu na serumske vrednosti fT4 (p<0,001). Tokom pet godina praćenja, broj hospitalizacija je bio signifikantno veći u grupi starijih bolesnika sa srčanom insuficijencijom i hipotireozom u odnosu na kontrolnu grupu (p<0,008). Od specifičnih kliničkih parametara ,u ispitivanoj grupi statistički je češće registrovan: subjektivni osećaj gušenja (p<0,009), nalaz bazalnih pukota (p<0,001), otoka nogu (p<0,004) , ST-T EKG promena apsolutne aritmije, veći broj bolesnika sa NYHA III ili IV klasom (p<0,004), bolesnika sa EF <45%, hipertrofija miokarda LK i perikardni izliv. Učestalost umrlih je bila statistički značajno veća u ispitivanoj grupi (p<0,001). Zaključak: Polazeći od poznatih činjenica da hormoni štitne žlezde utiču na rad kardiovaskularnog sistema sa jedne strane, a sa druge strane da i sama starost utiče kako na pojavu srčane insuficijencije tako i slabije funkcije štitne žlezde, u starijoj životnoj populaciji u prisustvu hipotireoze, hronična srčana insuficijencija ima lošiju prognozu, sa češćim smnrtnim ishodom, sa većim brojem NYHA III i IV klase bolesnika, manjom EF, većim brojem hospitalizacija, češćom pojavom angine pektoris, višim serumskim vrednostima ureje, kreatinina, kao i holesterola i triglicerida.INTRODUCTION: The aim of this work was to investigate the association of hypothyroidism with the emergence of heart failure in elderly people and determining the specific influence of hypothyroidism in the manner of presentation and method of treating heart failure in the elderly. METHOD: Testing has included 277 patients aged 65 years and over, who had a diagnosed heart failure. The study groups are the elderly with heart failure and hypothyroidism and control groups - elderly people with heart failure, but without clinical hypothyroidism hospitalized at the geriatric ward of the Clinical Center Zvezdara in Belgrade in the period since 2005. By 2010 the study was conducted in accordance with the Declaration of Helsinki (revised version, 1983 years) and has been approved by the ethical committee of the Medical Faculty of the University of Belgrade. All data are analyzed and presented measures of descriptive statistics. For comparison of continuous numerical variables with normal distribution was used t-test, while the comparison frequency used chi-square. Level of significance was p <0.05. Results: The average age in the group of respondents was 80.35 + -6.31, and in the control group 81.41 + -6.34 years. In the group with hypothyroidism was significantly more frequent occurrence of angina pectoris (p <0.001). In the same group was statistically higher in patients with previous prosthetic valve replacement (p = 0.022). In the study group of elderly patients with heart failure and hypothyroidism, compared to the control group, registered a statistically higher serum total cholesterol (p <0.001), LDL-cholesterol (p <0.001) and triglycerides (p <0.001). In relation to thyroid hormone status at baseline in the study group patients with SI and hypothyroidism had significantly higher serum TSH (p <0.001) and FT4 (p <0.048) compared to the control group. After a year of follow-up, there were more differences to TSH, while statistically significant difference remains in relation to serum fT4 (p <0.001). During five years of follow up, the number of hospitalizations was significantly higher in the group of elderly patients with heart failure and hypothyroidism compared to the control group (p <0.008). Of specific clinical parameters in the study group was statistically more frequently registered a subjective feeling of suffocation (p <0.009), a finding basal crackles (p <0.001), when legs (p <0.004), ST-T changes in ECG were arrhythmia, a larger number of patients with NYHA class III or IV (p <0.004), patients with EF <45%, LK hypertrophy and pericardial effusion. The incidence of deaths was significantly higher in the study group (p <0.001). Conclusion: Starting from the known fact that thyroid hormones affect the cardiovascular system on the one hand, and on the other side how age affects the occurrence of heart failure and poor thyroid function in the elderly population in the presence of hypothyroidism, chronic heart failure has worse prognosis, with a more frequent fatal outcome, with a number of NYHA class III and IV patients, lower EF, a larger number of hospitalization, higher incidence of angina pectoris, higher serum levels of urea, creatinine, and cholesterol and triglyceride levels

Supplementary data for the article: Savić, B. G.; Stanković, D. M.; Živković, S. M.; Ognjanović, M. R.; Tasić, G. S.; Mihajlović, I. J.; Brdarić, T. P. Electrochemical Oxidation of a Complex Mixture of Phenolic Compounds in the Base Media Using PbO2-GNRs Anodes. Applied Surface Science 2020, 529, 147120. https://doi.org/10.1016/j.apsusc.2020.147120

Supplementary material for: [https://doi.org/10.1016/j.apsusc.2020.147120]Related to published version: [https://cherry.chem.bg.ac.rs/handle/123456789/4177

Image clutter metrics and target acquisition performance

Introduction/purpose: Measuring target acquisition performance in imaging systems with human-in-the-loop plays an essential role in military applications. This paper presents an extended review on the application of image clutter metrics for target acquisition, with the aim of using objective measures to predict the detection probability, false alarm probability and mean search time of the target in the image. Methods: To determine the degree of clutter, simple features on the global (picture-wise) and local (target-wise) level were used as well as contrastbased clutter metrics, target size and metrics derived from image quality assessment measures. Along with the standard ones, the features derived from the distribution of mean subtracted contrast normalized coefficients were also used. To compare the results of the objective scores and the experimental results obtained on the publicly available Search_2 dataset, regression laws accepted in the literature were applied. Linear correlations and rank correlations were used as quantitative measures of agreement. Results: It is shown that the best agreement with target acquisition indicators is obtained by applying clutter metrics derived from image quality assessment measures. The correlation with the results of subjective tests is up to 90%, which indicates the need for further research. A special contribution of the paper is the analysis of the target acquisition prediction performance using simple features at the global and local level, where it is shown that the prediction performance can be improved by determining the features around the target. Furthermore, it was shown that the false alarm probability and the probability of detection can be predicted based on the mean target search time in the image with a probability higher than 90%. Conclusion: In addition to obtaining a high degree of agreement between the objective metrics of clutter and the results of subjective tests (up to 90%), there is a need to improve the existing and develop new metrics as well as to conduct new subjective tests

Microstructure assessment of Co alloy intended for dentistry

Cobalt–chromium–molybdenum (CoCrMo) alloys are known for medical use due to their biocompatibility, corrosion and wear resistance. The chemical and phase composition, as well as microstructure of the alloy directly affect the mechanical properties. In this investigation, CoCrMo alloy samples were obtained by vacuum precise casting. The procedure of melting and casting process as well as their parameters are given. Molds fabricated of copper, gray iron, steel, ceramics and graphite were used during the casting process. In this way, the cooling rate influence on the obtained microstructure was examined. Besides, different casting temperatures (1400°C, 1450°C and 1500°C) were applied for each kind of mold. After metallographic preparation, the microstructure was examined on the cross section of samples by optical microscopy. The obtained results show that by increasing the cooling rate, the microstructure of samples become finer and more homogeneous

Monte Carlo simulation as an alternative approach for estimation of uncertainty measurement of 2,4 dimethylphenol

The estimation of uncertainty measurement using different approaches is increasingly applied to assess the reliability of results generated by applied analytical methods. This paper presents the Monte Carlo simulation model (MCS) for calculating the uncertainty of the measurement associated with the result of the analysis. The results of MCS were compared with the commonly used a standard method (GUM). The calculations of the measurement uncertainty were demonstrated in the case of the determination of 2,4-dimethylphenol by gas chromatography in concrete samples.14th international conference on fundamental and applied aspects of physical chemistry; 24-28 September 2018, Belgrade, Serbia

Synthesis, characterization and cytotoxicity of a palladium(II) complex of 3-[(2-hydroxybenzylidene)amino]-2-thioxoimidazolidin-4-one

The polydentate ligand 3-[(2-hydroxybenzylidene)amino]-2-thioxoimidazolidin-4-one was synthesized in the intermolecular cyclocondensation reaction of 2-hydroxybenzaldehyde thiosemicarbazone and ethyl chloroacetate. A novel palladium(II) complex was obtained from cis-[Pd(DMSO)(2)Cl-2] by nucleophilic substitution of both DMSO ligands with the iminic nitrogen and the thiolactamic sulfur from the ligand. The structures of the compounds were characterized based on their spectral data. The cytotoxic activities of the ligand and the palladium(II) complex were studied on the tumor cell lines: human colon carcinoma HCT-116 and SW-480 cells using the MTT viability test. The results showed that the investigated palladium(II) complex had a significantly greater cytotoxic effect compared to that of the ligand

Systematics of c-axis Phonons in the Thallium and Bismuth Based Cuprate Superconductors

We present grazing incidence reflectivity measurements in the far infrared region at temperatures above and below Tc for a series of thallium (Tl2Ba2CuO6, Tl2Ba2CaCu2O8) and bismuth (Bi2Sr2CuO6, Bi2Sr2CaCu2O8, and Bi(2-x)Pb(x)Sr2CaCu2O8) based cuprate superconductors. From the spectra, which are dominated by the c-axis phonons, longitudinal frequencies (LO) are directly obtained. The reflectivity curves are well fitted by a series of Lorentz oscillators. In this way the transverse (TO) phonon frequencies were accurately determined. On the basis of the comparative study of the Bi and Tl based cuprates with different number of CuO2 layers per unit cell, we suggest modifications of the assignment of the main oxygen modes. We compare the LO frequencies in Bi2Sr2CaCu2O8 and Tl2Ba2Ca2Cu3O10 obtained from intrinsic Josephson junction characteristics with our measurements, and explain the discrepancy in LO frequencies obtained by the two different methods.Comment: 8 pages Revtex, 6 eps figures, 3 tables, to appear in Phys. Rev.

Smart Tourism Destinations: Can the Destination Management Organizations Exploit Benefits of the ICTs? Evidences from a Multiple Case Study

Recent developments of ICTs enable new ways to experience tourism and conducted to the concept of smart tourism. The adoption of cutting-edge technologies and its combination with innovative organizational models fosters cooperation, knowledge sharing, and open innovation among service providers in tourism destination. Moreover, it offers innovative services to visitors. In few words, they become smart tourism destinations. In this paper, we report first results of the SMARTCAL project aimed at conceiving a digital platform assisting Destination Management Organizations (DMOs) in providing smart tourism services. A DMO is the organization charged with managing the tourism offer of a collaborative network, made up of service providers acting in a destination. In this paper, we adopted a multiple case studies approach to analyze five Italian DMOs. Our aims were to investigate (1) if, and how, successful DMOs were able to offer smart tourism services to visitors; (2) if the ICTs adoption level was related to the collaboration level among DMO partners. First results highlighted that use of smart technologies was still in an embryonic stage of development, and it did not depend from collaboration levels