Search results for "Microstructure"
showing 10 items of 707 documents
The Effect of Dopants on Sintering and Microstructure of Lead-free KNN Ceramics
2011
Lead-free potassium sodium niobate (K0.5Na0.5)NbO3 (KNN) has been prepared via conventional ceramic processing method. The influence of 0.5 wt% - 1.5 wt% MnO2 and WO3 addition on the sintering, crystallographic structure, microstructure and dielectric properties of KNN has been investigated. Optimal sintering temperatures of KNN ceramics were observed to be in the narrow interval: 1090 °C - 1110 °C for MnO2 doped KNN; 1150 °C - 1170 °C for pure KNN and doped with WO3. XRD patterns showed that all the samples have single perovskite structure with monoclinic structure. Microstructure of ceramics was changed greatly by using dopants.http://dx.doi.org/10.5755/j01.ms.17.1.251
Statistics of order flow
2010
Effects of diet-induced obesity and voluntary wheel running on the axial and peripheral skeleton microstructure in mice
2010
Intensity of Respiratory Cortical Arousals Is a Distinct Pathophysiologic Feature and Is Associated with Disease Severity in Obstructive Sleep Apnea …
2021
Background: We investigated whether the number, duration and intensity of respiratory arousals (RA) on C3-electroencephalographic (EEG) recordings correlate with polysomnography (PSG)-related disease severity in obstructive sleep apnea (OSA) patients. We also investigated if every patient might have an individual RA microstructure pattern, independent from OSA-severity. Methods: PSG recordings of 20 OSA patients (9 female
A microstructure based mechanical model for planar fibrous scaffolds.
2010
Cardiac valve and myocardium tissue regeneration has consistently raised interest for cell-seeded/microintegrated planar fibrous scaffolds. Electrospun constructs, decellularized tissues and collagen/fibrin gels often show a similar microstructure mainly characterized by the fibrous network topology. Microstructure based mechanical modeling enable fabrication parameters and scaffolds morphology to be related to mesomacro mechanical response. A novel approach to (1) characterize the material fibers network microarchitecture, (2) reproduce stochastically equivalent fiber network models, and (3) predict the mechanical response at meso-macro level is presented in this work. Electron micrographs…
Assessment of the Inter-Batch Variability of Microstructure Parameters in Topical Semisolids and Impact on the Demonstration of Equivalence
2019
Demonstration of similar microstructure is essential for demonstrating the equivalence of generic topical products since the microstructure of semisolids may affect the drug release. The objective of this study was to compare the microstructure-defining physical parameters of different batches of a reference ointment containing calcipotriol and betamethasone (Daivobet 50 µ
Nodular cast iron fatigue lifetime in cyclic plane bending
2012
The fatigue behavior of a component is strongly dependent on the material and its surface condition. Therefore, the manner in which the surface is prepared during component manufacturing (surface roughness, residual stresses etc.) has a decisive role in dictating the initiation time for fatigue cracks. The fatigue behavior of the same material, a nodular cast iron, with three different surface conditions (fine ground, sand blast and as-cast) has been investigated under cyclic plane bending. The results show differences in fatigue strength, which are associated with the surface conditions. The characteristics of the surface layers of the different test specimens were examined by metallograph…
Predicting stiffness and strength of birch pulp:Polylactic acid composites
2016
This paper studies failure of birch pulp–polylactic acid composites. Stiffness and strength are calculated using the theory of short fibre composites and the results are compared to experimental data. The results differed from the experimental values by 0–6%. With less aligned fibres the short fibre theory is not feasible. The performance of the 40 wt% birch pulp – polylactic acid composite is predicted with X-ray microtomography based finite element modelling, and the results are compared with experiments. Stiffness results differed from experiments by 1–17% . By adding into the models a third material phase representing the interface between the fibres and the matrix, the stress–strain c…
Evolution of the microstructure of sputter deposited TaAlON thin films with increasing oxygen partial pressure
2021
Recently, quaternary oxynitrides of transition metals and aluminum have attracted increasing interest due to their tunable properties. Within the present work, a series of TaAl(O)N films was sputter deposited using constant nitrogen and varying oxygen partial pressures. The films were grown from single element Ta and Al targets. The deposition parameters were adjusted to obtain a Ta/Al atomic ratio of ~50/50 for the oxygen-free film and were held constant for the following depositions, with the exception of the increasing oxygen partial pressure and compensatory decreasing argon partial pressure. Elastic recoil detection analysis revealed oxygen contents of up to ~26 at.%, while the nitroge…
The microstructure of bentonite clay
2018
Bentonite is a common clay having many applications. One of them will be in the spent nuclear fuel repository, as a buffer material between host rock and the canisters containing the radioactive waste. This application has high requirements for the material used, ranging from, among others, appropriate mechanical properties, chemical stability, fine porous structure to sufficient hydraulic conductivity. The material should maintain its properties over time as the life span of the repository is hundreds of thousands years. The aim of this thesis was to investigate the structure of bentonite clay in a condition similar to expected in the repository. The research focused mainly on the pore str…