Mechanical Properties of Yttria- and Ceria-Stabilized Zirconia Coatings Obtained by Suspension Plasma Spraying

Plasma generated by the SG-100 torch was applied to spray suspension formulated with the use of ZrO₂ + 8 wt.% Y₂O₃ (8YSZ) and ZrO₂ + 24 wt.% CeO₂ + 2.5 wt.% Y₂O₃ (24CeYSZ) as solid phases. The suspensions were formulated with the use of 20 wt.% solid phase, 40 wt.% water, and 40 wt.% ethanol. The plasma spray parameters were optimized by keeping constant: (a) the electric power of 40 kW and (b) the working gas compositions of 45 slpm for Ar and 5 slpm for H₂. On the other hand, the spray distance was varied from 40 to 60 mm and the torch linear speed was varied from 300 to 500 mm/s. The coatings were sprayed onto stainless steel substrates, and their thicknesses were in the range from 70 to 110 μm. The coating microstructures were analyzed with a scanning electron microscope. Mechanical properties were tested with the different methods including the indentation and scratch tests. The indentation test, carried out with various loads ranging from 100 to 10,000 mN, enabled to determine elastic modulus and Martens microhardness. Young’s modulus of the coatings was in the range of 71-107 GPa for 8YSZ and 68-130 GPa for 24CeYSZ coatings. The scratch test enabled the authors to find the scratch macrohardness.     

Resistance A La Corrosion D'ensembles Soudes En Alliages De Titane—Influence De L'etat Structural

An investigation of the potentiodynamic polarization behaviour of some titanium alloys welds has shown that their corrosion resistance is not significantly influenced by variation of micro-structure, even in melted and heat-affected zones. For comparison, some microstructures similar to those observed in welds were also studied. Slight variations concern only the passive behaviour of these alloys which are unaffected in the active state by microstructural changes. Interpretations of peculiar behaviour of Ti–2, 5%Cu alloy are suggested.     

RACFP: a training tool to work with floating-point representation, algorithms, and circuits in undergraduate courses

The design of pedagogical tools to train students is an interesting challenge for academic instructors in any educational area. Some approaches have appeared focusing on computer arithmetic, both integer and floating point. Floating-point arithmetic involves much more complexity; nevertheless, little time is usually devoted to this topic in computer engineering undergraduate courses. In this paper, RACFP is proposed as a pedagogical tool to work with floating-point in undergraduate courses. The tool has been designed with three abstraction levels according to the following learning outcomes: representation, arithmetic operation algorithms, and manufactured hardware circuits. The abstraction levels work independently, allowing for the use of RAC/sub FP/ in other courses, such as discrete mathematics or numerical methods, in which floating representation and related issues are also learning topics. RACFP design pursues two main goals: to minimize the complexity of the learning process and to encourage students when working with floating point. The first goal is achieved as a result of the multilevel design of the tool, while the second goal is achieved as RAC/sub FP/ shows how manufactured hardware implements generic algorithms.     

Analysis of thin PZT films as a function of depth and thickness by GIXS

Abstract

We have performed depth profile studies on PZT films of different thickness. Thin epitaxial films of PbZr_0.2Ti_0.8O₃ have been deposited on mono-crystalline (001) LaAlO₃ substrate by pulsed laser deposition. Grazing incidence X-ray scattering was used to study the films' structure. GIXS technique was used to analyze the in-plane compression of lattice parameters as a function of depth within the films.     

Mapping the Chemical Variability of Vegetable Lecithins

There is an increasing interest in vegetable lecithins because of their broad usage in many food and cosmetic applications. In this research, the chemical variability of commercial lecithins from soy, sunflower and rapeseed were mapped. The acetone insoluble matter, total phospholipid content and their compositions were determined. Significant correlation coefficients were observed between phosphatidylcholine and phosphatidic acid (?0.84), phosphatidylethanolamine and phosphatidylinositol (?0.86), monounsaturated fatty acid and polyunsaturated fatty acid (?0.97). Principal component analysis was used to group the lecithins according to their sources. Rapeseed lecithin was found to be the most different product compared to soy and sunflower lecithin.     

InN Stillinger-Weber参数：用于InxGa1-xN合金

使用Stillinger-Weber(SW)类型经典势,研究了InxGa1-xN合金的原子结构以及富铟Clusters引起的InGaN/GaN量子阱的形变.SW参数来自氮化铟晶体常数和闪锌矿及铅锌矿结构中的弹性常数.还给出了含有富铟团簇的量子阱的能量.