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Spinel LiMn2O4 particles were successfully synthesized by an ultrasonic spray pyrolysis method from the precursor solutions; various combinations of nitrate, acetates or formats of lithium and manganese were stoichiometrically dissolved in distilled water. The product characteristics, such as crystallinity, specific surface area, particle morphology and interior structure of particles, were examined with X-ray diffraction (XRD), the Brunauer–Emmet–Teller (BET) method, field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). All the samples exhibited a pure cubic spinel structure without any impurities in the XRD patterns, while the surface morphology of as-prepared powders was classified into four patterns and the interior structure three patterns.The as-prepared samples were then used as cathode active materials for lithium-ion battery, and electrochemical studies were carried out on the charge/discharge characteristics of the Li/LiMn2O4 cells. The effect of LiMn2O4 particle properties such as crystallite size, specific surface area and particle morphology on the electrochemical properties were also discussed in details. [Copyright &y& Elsevier]

The deposition of gadolinia-doped ceria (CGO, Gd0.1Ce0.9O1.95) and LaGaO3-based perovskite oxides (LSGM, La0.9Sr0.1Ga0.8Mg0.2O2.87) thin films on a stainless steel substrate was studied using the electrostatic spray deposition (EDS) technique. The effect of process conditions, such as deposition temperature, deposition time and liquid flow rate, on the surface morphology and microstructure of thin films was examined with scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The deposited CGO films with a highly porous and three-dimensional interconnected structure were obtained at a liquid flow rate of 0.5 ml/h, a deposition temperature of 503 K and a deposition time ranging from 0.5 to 1 h. On the other hand, the deposited LSGM thin films with porous microstructure were also obtained at the deposition time of 1 h, the deposition temperature of 533 K and the liquid flow rate of 0.5 ml/h. The deposited CGO and LSGM thin films were amorphous at the used deposition temperature. Subsequently, the samples were annealed at 1173 K for 2 h and the desired crystal structures were obtained. The chemical analysis of the thin films was investigated by energy dispersive X-ray (EDX) analysis. The observed chemical compositions of the samples were in a fair agreement with those of the starting solutions. [Copyright &y& Elsevier]

Spinel lithium manganese oxide LiMn2O4 and its substituted forms LiM1/6Mn11/6O4 (M=Co, Al and Ni) were prepared by ultrasonic spray pyrolysis method. As-prepared particles showed a spherical morphology and a densely congested interior structure. The geometric mean diameter was between 0.76 and 0.93 μm, and the geometric standard deviation was approximately 1.33. The crystallite size was approximately 30 nm, and the specific surface area of the particles ranges from 5.7 to 12.7 m2/g. As-prepared particles were used as cathode active materials for lithium secondary battery and their charge/discharge properties have been investigated. As a result, it could be seen that ultrasonic spray pyrolysis is an effective method to prepare lithium manganese oxide (LiMn2O4) and its substituted forms within very short production time, which is only 4.8 min in the present work. [Copyright &y& Elsevier]

This study examined the fate of target sites that escaped high-grade restenosis (> or = 70% diameter narrowing) after percutaneous transluminal coronary angioplasty. Although favorable long-term prognosis after successful percutaneous transluminal coronary angioplasty is well documented, little is known about the stability of target sites. Long-term follow-up (mean 6.5 years, range 1.0 to 12.0) was performed in 693 patients with 948 narrowings (stenosis <70% in diameter at follow-up coronary angiography). Among them, 249 patients (36%) with 303 target sites received late follow-up coronary angiography. The relation of target sites to the culprit lesions for coronary events or newly developed angina was angiographically reviewed and progression/regression was also examined, focusing on the target sites. Regression was observed in 16 of 255 target sites in subjects with <50% stenosis and in 21 of 48 sites in the group with midgrade stenosis of 50% to 69% luminal narrowing (16 of 255, 6.3% vs 21 of 48, 43.8%, p <0.001). Progression was observed in 33 and 4 sites (33 of 255, 12.9% vs 4 of 48, 8.3%; p = NS) in each group, respectively. The rest remained within the same range of stenosis. Culprit lesions for 2 acute myocardial infarctions, 7 unstable anginas, and 17 newly developed anginas were related to the original target sites. Three lesions developed in the midgrade stenosis group. Those 26 lesions were a component of 8.6% of 303 angiographically confirmed sites and 2.7% of total target sites. Target sites that escape high-grade restenosis frequently regress and become stable plaques and rarely trigger coronary events. [ABSTRACT FROM AUTHOR]