Mixed oxides NiO/ZnO/Al2O3 synthesized in a single step via ultrasonic spray pyrolysis (USP) method

Mixed oxides have received remarkable attention due to the many opportunities to adjust their interesting structural, electrical, catalytic properties, leading to a better, more useful performance compared to the basic metal oxides. In this study, mixed oxides NiO/ZnO/Al2O3 were synthesized in a single step via the ultrasonic spray pyrolysis method using nitrate salts, and the temperature effects of the process were investigated (400, 600, 800 \ub0C). The synthesized samples were characterized by means of scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction and Raman spectroscopy analyses. The results showed Al2O3, NiO–Al2O3 and ZnO–Al2O3 systems with spinel phases. Furthermore, the Raman peaks supported the coexistence of oxide phases, which strongly impact the overall properties of nanocomposite

One step production of silver-copper (Agcu) nanoparticles

AgCu nanoparticles were prepared through hydrogen-reduction-assisted Ultrasonic Spray Pyrolysis (USP) and the Hydrogen Reduction (HR) method. The changes in the morphology and crystal structure of nanoparticles were studied using different concentrated precursors. The structure and morphology of the mixed crystalline particles were characterized through X-ray diffraction analysis (XRD), scanning electron microscopy (FEG-SEM), transmission electron microscopy (TEM) and Energy-dispersive X-ray spectroscopy (EDS). The average particle size decreased from 364 nm to 224 nm by reducing the initial solution concentration from 0.05 M to 0.4 M. These results indicate that the increase in concentration also increases the grain size. Antibacterial properties of nanoparticles against Escherichia coli were investigated. The obtained results indicate that produced particles show antibacterial activity (100%). The AgCu nanoparticles have the usage potential in different areas of the industry

High-pressure x-ray diffraction study of SrMoO4 and pressure-induced structural changes

SrMoO4 was studied under compression up to 25 GPa by angle-dispersive x-ray diffraction. A phase transition was observed from the scheelite-structured ambient phase to a monoclinic fergusonite phase at 12.2(9) GPa with cell parameters a = 5.265(9) A, b = 11.191(9) A, c = 5.195 (5) A, and beta = 90.9, Z = 4 at 13.1 GPa. There is no significant volume collapse at the phase transition. No additional phase transitions were observed and on release of pressure the initial phase is recovered, implying that the observed structural modifications are reversible. The reported transition appeared to be a ferroelastic second-order transformation producing a structure that is a monoclinic distortion of the low-pressure phase and was previously observed in compounds isostructural to SrMoO4. A possible mechanism for the transition is proposed and its character is discussed in terms of the present data and the Landau theory. Finally, the EOS is reported and the anisotropic compressibility of the studied crystal is discussed in terms of the compression of the Sr-O and Mo-O bonds.Comment: 36 pages, 9 figures, 1 tabl

The behavior of organic components in copper recovery from electroless plating bath effluents using 3D electrode systems

An electrochemical method was applied for the recovery of copper both from the spent solutions and from the rinse waters of electroless copper plating baths, containing copper sulfate, formaldehyde, quadrol, and NaOH. Experiments were conducted in a rotating packed cell (Rollschichtzelle((R))) to investigate the effects of current density, electrolyte composition, temperature, and pH on the copper recovery. All the copper (final C-cu = 0.1 ppm) was recovered from the waste and rinse waters of chemical copper plating plants with 70% current efficiency by the electrochemical treatment in a rotating packed cell at 130 A/m(2) current density, room temperature, with 5 mm diameter cathode granules, with the presence of formaldehyde, and with a specific energy consumption of 3.2-3.5 kW h/kg Cu. On the other hand, final copper concentrations of 5 ppm were reached with 62% current efficiency and 5.5-5.8 kW h/kg Cu specific energy consumption, with electrolytes containing no formaldehyde. (C) 2004 Elsevier B.V. All rights reserved

Field trials of no-decompression stop limits for diving at 3500 m

Introduction: In 1990, Bogazici University (Istanbul, Turkey) launched an altitude diving program to develop techniques and safe decompression profiles for diving at high terrestrial altitudes. Following pioneering diving expeditions to lakes at high elevations in 1990-1992, it was deemed necessary to calculate new tables. Methods: Bottom time limits for dives requiring no decompression stops (no-d) were calculated for 3500 m using linear extrapolation of U.S. Navy M-values decreased by 4 ft of sea water (M4 limits). These limits were tested for 15, 18, 21, 24, 27, and 30 m of depth by diving in the Great Sea Lake at Mt Kackar (3412 m) with 10 dives per profile. Results. The mean decompression sickness (DCS) risk estimated from precordial bubble scores (Spencer Scale) ranged from 0.3% to 2.8% per profile. After three expeditions, 165 dives had been achieved with a cumulative bottom time of 3199 min. No DCS occurred in dives that adhered to the M4 no-d limits. However, two cases of Type I and one case of Type II DCS were encountered where the divers accidentally exceeded those limits. Discussion: Considering the estimated risk of DCS and the relatively small number of trials, a more conservative approach was used to develop a final set of high altitude dive tables. This conclusive approach used continuous compartment half-lives. It is based on fitting a surface of allowable supersaturation limits using the empirical M-values from existing tables as well as our altitude diving data, together with an added constraint that forces calculated M-values to stay below the available M-value data

Synthesis, structural and magnetic characterization of soft magnetic nanocrystalline ternary FeNiCo particles

The present study focuses on the synthesis, microstructural and magnetic properties of ternary FeNiCo nanoparticles. Nanocrystalline ternary FeNiCo particles were synthesized via hydrogen reduction assisted ultrasonic spray pyrolysis method in single step. The effect of precursor concentration on the morphology and the size of particles was investigated. The syntheses were performed at 800\ua0\ub0C. Structure, morphology and magnetic properties of the as-prepared products were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) studies. Scherer calculation revealed that crystallite size of the ternary particles ranged between 36 and 60\ua0nm. SEM and TEM investigations showed that the particle size was strongly influenced by the precursor concentration and Fe, Ni, Co elemental composition of individual particles was homogeneous. Finally, the soft magnetic properties of the particles were observed to be a function of their size

Synthesis, structural and magnetic characterization of soft magnetic nanocrystalline ternary FeNiCo particles

The present study focuses on the synthesis, microstructural and magnetic properties of ternary FeNiCo nanoparticles. Nanocrystalline ternary FeNiCo particles were synthesized via hydrogen reduction assisted ultrasonic spray pyrolysis method in single step. The effect of precursor concentration on the morphology and the size of particles was investigated. The syntheses were performed at 800\ua0\ub0C. Structure, morphology and magnetic properties of the as-prepared products were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) studies. Scherer calculation revealed that crystallite size of the ternary particles ranged between 36 and 60\ua0nm. SEM and TEM investigations showed that the particle size was strongly influenced by the precursor concentration and Fe, Ni, Co elemental composition of individual particles was homogeneous. Finally, the soft magnetic properties of the particles were observed to be a function of their size

Fracture of popliteal artery stents

In peripheral arterial obstructive disease, more than 50% of all lesions are localized in the femoropopliteal segment and surgical revascularization is the treatment of choice. Percutaneous transluminal angioplasty (PTA) is recommended for short lesions, with subsequent stent implantation if the result is sub-optimal or dissections occur after PTA or for restenosis. There are both acute and late complications with stent implantation. In the present patient, stents were placed in the left popliteal artery where the left knee joint flexes, and obstruction because of stent fracture occurred 6 months later. The patient eventually underwent left femoro-popliteal saphenous vein bypass grafting

A chronic coronary pseudoaneurysm after stent implantation

Recently, as a part of new stent implantation strategy in order to decrease stent thrombosis, final dilatations with high pressure and/or higher sized balloons were applied after the initial deployment of the stent. In this paper, we presented a case of chronic coronary pseudoaneurysm which occured after an initially successful stent implantation in the left anterior descending artery, probably due to high pressure final dilatation

Rescue coronary stenting with heparin-coated Jostents for failed thrombolysis in acute myocardial infarction

The aim of the present study was to assess the procedural safety and in-hospital and long-term effectiveness of heparin-coated Jostents after failed thrombolysis in acute myocardial infarction. We prospectively analyzed the acute and long-term clinical and angiographic outcornes of 35 consecutive patients treated with heparin-coated Jostents for thrombolytic failure. Rescue coronary stenting was successful in 34 of 35 patients (97%). Thrombolysis in Myocardial Infarction flow grade 3 was obtained in 31 patients (88.5%). The only patient with procedural failure died from cardiogenic shock a day after the procedure. One patient (2.8%) underwent an emergency coronary bypass operation because of angiographic evidence of stent thrombosis with re-infarction. During in-hospital follow-up, 2 patients (5.7%) underwent an elective coronary bypass operation after successful stent implantation of the infarct-related artery because of existing severe multivessel coronary artery disease. Minor bleeding complications at the vascular access site occurred in 3 (8.6%) patients. No cerebrovascular or any other major bleeding complication occurred. One patient (2.1%) underwent repeat coronary angioplasty for restenosis and an elective coronary artery bypass operation was performed in one patient (2.8%) during the 294 +/- 150 days follow-up. The rate of target vessel revascularization was 14.3% and the event-free survival rate was 80%. Twenty-six patients (90%) had angiographic follow-up at six months, and stent restenosis was found in 5 (19.2%). This study demonstrates that heparin-coated Jostents are safe, with low in-hospital and long-term mortality fates for the treatment of failed thrombolysis in acute myocardial infarction. The angiographic restenosis and target vessel revascularization rates of this registry are also acceptable