169,970 research outputs found
Sheykh ül-islam Feyzullah Efendi and the Armenian Patriarch Awetik‘: a case of entangled confessional disciplining?
No full textAmong the Sheyk ül-islams, the chief religious authority of the Ottoman Empire, Feyzullah Efendi is one of the best known and most studied. This is certainly due to the incredible amount of power and wealth he was able to obtain during his tenure, as well as to his sudden and tragic end during the Rebellion of 1703. What is less known is that he played a central role in the religious and social turmoil which affected the Eastern Christian communities of the Empire at the turn of the eighteenth century, interfering directly in the ecclesiastical organization of the Syriac and especially Armenian Church. Already in 1692, when he was still a qadi in Erzurum, he meddled in the disputes between Catholic missionaries and Armenian Apostolic prelates, supporting the latter against the former and provoking the intervention of the French Ambassador, who obtained the exile of the local Armenian bishop. Few years later, once reached the summit of power, he resumed his fight against Catholic propaganda by appointing as Armenian Patriarch of Constantinople (and later of Jerusalem too) the very same bishop he had sided with in Erzurum, Awetik' Ewdokac’i. The condition behind these appointments was that Awetik‘ would have directed his efforts to stop the work of Catholic missionaries among the Armenians, punishing those who had been converted to the «Frank» religion. But why a high-ranking Ottoman officer should have been concerned by the doctrinal quarrels going on within the Eastern Christian communities? By cross-checking Ottoman, Western and Armenian sources, my chapter addresses this question, highlighting the political and entangled dimension of the Ottoman Confessionalization
Detailed survey on minimum activation energy for penetration of Ni nanoparticles into Bi-2223 crystal structure and temperature-dependent Ni diffusivity
No full textThe primary contributions of this study are not only to explore the role of diffusion annealing temperature interval 650 to 850 A degrees C on the formation of effective electron-phonon coupling or cooper-pair probabilities (percentage of clusters in the superconducting path), densities of active and dynamic electronic states at Fermi energy level, stabilization of superconductivity in the homogeneous regions, overlapping of Cu-3d and O-2p wave functions and bond strengths in the crystal matrix of Ni surface-layered Bi-2223 polycrystalline ceramics, but also to determine the temperature-dependent diffusion fast-rate and required minimum activation energy for the diffusion of Ni foreign impurities into the bulk Bi-2223 superconducting crystal structure for the first time. The dc electrical measurement results obtained show that the optimum diffusion annealing temperature is found to be 700 A degrees C for the penetration of optimum Ni concentration into the Bi-2223 crystal lattice so that the ceramic compound exposed to 700 A degrees C annealing temperature exhibits the highest electrical and superconducting properties. In this respect, the material with the minimum electrical resistivity parameters of Delta rho, rho (115K) , rho (res) and rho (norm) obtains the maximum superconducting characteristics of , and RRR. Accordingly, the annealing temperature of 700 A degrees C promotes the Bi-2223 ceramics for usage in the engineering, electro-optic, industrial and large scale applications. At the same time, the diffusion coefficients [D = D(o)exp(E/k(B)T)] determined at annealing temperature ranging from 650 to 850 A degrees C are observed to be much more significant at rather higher temperatures as compared to lower temperatures. The temperature-dependent Ni diffusion coefficient is determined to be D = 3.9707 x 10(- 7)exp[- 1.132 eV/k(B)T] for the Bi-2223 particulate solid material. Namely, the diffusion coefficient is calculated to be about 3.9707 x 10(- 7)cm(2) s(- 1) when the required minimum activation energy for the introduction of heavy metal Ni ions to the bulk Bi-2223 crystal structure is computed to be about 1.132 eV, being one of the most striking points deduced form this work
SYNTHESIS OF MAGNESIUM SILICATE FROM WHEAT HUSK ASH: EFFECTS OF PARAMETERS ON STRUCTURAL AND SURFACE PROPERTIES
No full textTERZIOGLU, Pinar/0000-0003-4114-7044WOS: 000311336800077In the present study, magnesium silicate was produced by using wheat husk ash. Wheat husk was burned at 600 degrees C to obtain an amorphous ash structure, and the ash was processed with sodium hydroxide solution with heat to extract silica. Sodium silicate solution and magnesium salts were used to synthesize magnesium silicate. The present study investigates effects of the feeding rate on magnesium silicate production (0.6 mL/min, 35 mL/min, 70 mL/min), the type of magnesium salt (MgSO4 center dot 7H(2)O or MgCl2 center dot 6H(2)O), temperature (25 degrees C or 50 degrees C), and the washing agent ( water and acetone) on the chemical composition and surface characteristics of magnesium silicate. The results demonstrated that all of the variables affected the surface characteristics of magnesium silicate, such as surface area, particle size, and pore volume. However, it was also observed that the studied parameters did not affect the chemical composition of magnesium silicate. The wheat husk ash-based magnesium silicates obtained in the experimental study had a BET surface area ranging from 79 to 91 m(2)/g and a particle size varying from 42 to 63 mu m.Yildiz Technical University, Coordination of Scientific Research Projects (BAP)Yildiz Technical University [29-07-04-YL05]This study was funded by Yildiz Technical University, Coordination of Scientific Research Projects (BAP) with project number 29-07-04-YL05
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Structural and physical properties of Sm-doped Bi1.6Pb0.4Sr2Ca2-xSmxCu3Oy superconductors
No full textOzturk, Ozgur/0000-0002-0391-5551; Terzioglu, Cabir/0000-0002-3944-0367The superconducting Bi1.6Pb0.4Sr2Ca2-xSMxCu3Oy (X = 0.0, 0.0005, 0.001, 0.005, 0.01, 0.1, 0.5, 1.0, and 1.5) system was investigated for different concentrations of Sm. The structural analysis was carried out by XRD. XRD results show that the samples with substitution of various amounts of Sm for Ca transform from the major high-T-c phase (Bi-2223) to the low-T-c phase (Bi-2212). The lattice parameter data extracted from XRD showed that with increasing Sm concentration (x), the lattice parameter a increases slightly while the lattice parameter c decreases significantly. DC resistivity measurements were carried out by the standard four-probe technique in the temperature range between 25 K and 130 K. With increasing Sm substitution up to x = 0.1, the values of T-e(offset) vary between 107 K and 70 K. The samples with x > 0.1 did not show any superconducting transition down to 25 K. The critical current density measurements were performed in liquid nitrogen. Critical current density decreases with increasing Sm substitution, and it was measured to be 43 A/cm(2) for the sample with x = 0.0 at zero field. Microstructure examinations were carried out by SEM. All the reported data were discussed, and compared with earlier results on Sm and other substituted Bi-Sr-Ca-Cu-O system. (c) 2005 Elsevier B.V. All rights reserved
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Investigation of some physical properties of Gd added Bi-2223 superconductors
No full textX-ray powder diffraction (XRD), scanning electron microscopy (SEM), dc electrical resistivity, critical current density and static microindentation measurements are performed to investigate some physical properties of Bi(1.8)Pb(0.35)Sr(1.9)Ca(2.1)Cu(3)Gd(x)O(y) superconducting samples with x = 0.0, 0.1, 0.3 and 0.5. We observe from the transport measurements that, for the Gd added sample, the critical transition temperature (T(c)) and the critical current density (J(c)) are decreased in comparison with that of undoped sample. In addition, surface morphology and grain connectivity of the samples are degraded and the high-T(c) phase of the samples decreases with increasing Gd addition. The indentation load versus diagonal length of the samples under different indentation loads in the range of 0.245-2.940 N are measured. The microindentation measurements showed that, for the Gd added sample, the load dependent (apparent) microhardness value (H(v)) is lower in comparison with that of the pure sample (x = 0). The values of H(v) are found to be load dependent. In addition, we extract the load independent (true) microhardness using the Kick's law, proportional specimen resistance (PSR), modified proportional specimen resistance (MPSR) and the Hays-Kendall (HK) approach and compare the true hardness with the apparent hardness. The possible reasons for the observed degradation in microstructure, superconducting and mechanical properties due to Gd addition are discussed. (C) 2010 Elsevier B.V. All rights reserved
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Investigation of Cr addition effect on structural, morphological, electrical and magnetic properties of Bi(Pb)-2212 superconductors
No full textThe main purpose of this research work will assess the effect of Cr addition on the properties of Bi1.8Pb0.4Sr2CaCu2O8+d superconducting ceramics. The samples are produced from industrial powders with different amounts of Cr (0, 1, 2, 3, 4, 5, 6 and 7 wt %) by sol–gel synthesis route. The influence of doping element has been determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), electrical resistivity and magnetic characterizations. In particular, the eventual presence of secondary phases as a result of Cr doping on the undoped sample was investigated by using XRD. By means of SEM analysis, the Cr doping influence on the grain morphology of the samples was explored. Contrarily, the Tc,on and the Tc,off of the samples have been obtained by using electrical resistivity measurements and their behavior as a function of the Cr doping has been discussed. Finally, by performing magnetization analysis versus temperature and magnetic field, the behavior of the critical temperature Tc and of the critical current density Jc as a proportion of the Cr concentration has been discussed
Journal of Physics Conference Series
No full textWe investigated the effect of cooling rates on the microstructure and mechanical properties of Bi(1,6)Pb(0,4)Sr(2)Ca(2)Cu(3)Oy superconductors prepared by standard solid state reaction methods. The samples were annealed under identical condition and cooled with different cooling rates. The investigations consisted of Vickers microhardness, SEM and XRD measurements. XRD examination of the samples showed that high percentage of Bi-2212 phase was observed and low-T(c) phase increased with increasing the cooling rates. From SEM analysis, flake-like grains were more pronounced with increasing cooling rates. The indentation load versus diagonal length of the samples under different indentation loads in the range of 0.245-2.940 N were presented. We calculated Vickers hardness, Young's modulus, yield strength, fracture toughness values. These mechanical properties of the samples were found to be load and cooling rate dependent. In addition, we calculated the load independent microhardness, Young's modulus, and yield strength and fracture toughness of the samples using different models. The possible reasons for the observed changes in microstructure and mechanical properties of the samples due to cooling rates were discussed
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