Comparative Analysis of Hard Anodized Layer on Aluminium Alloy

2014 ◽  
Vol 782 ◽  
pp. 615-618
Author(s):  
Lenka Klakurková ◽  
Eduard Hégr ◽  
Ladislav Čelko ◽  
Tomáš Podrábský ◽  
Martin Juliš ◽  
...  

Hard anodized layers were produced by two different manufacturers on the same type of aluminium alloy on a vacuum pump part of complex shape. The sulphuric acid/water solution was used to produce alumina layers, which were subsequently sealed in demineralized water. A comparative analysis based on metallographic methodology, with the aim to control the stability of alumina formation process and to identify its defects, was performed by means of light and scanning electron microscopy, surface profilometry and microhardness measurements. To determine the thickness of alumina layers, the image analysis was also used.

2018 ◽  
Vol 52 (2) ◽  
pp. 379-385 ◽  
Author(s):  
S. L. Stephenson ◽  
Yu. K. Novozhilov ◽  
P. Wellman

A new species of Cribraria, described herein as C. bicolor, appeared in moist chamber cultures on samples of the bark of Eucalyptus sp. collected at two localities in Australia. The morphology of representative specimens was examined by light and scanning electron microscopy, and micrographs of relevant morphological details of sporocarps and spores are provided. The species has a number of distinct and unique morphological features, including a glossy bright-violet globose sporotheca and a two-colored long stalk which is bright-red over the lower one-third and light yellow or lemon-yellow over the upper two-thirds. The combination of these characteristics as well as a shallow calyculus which is dark-violet when viewed under a dissecting microscope and bright red in transmitted light when mounted in lactophenol makes C. bicolor a well-defined morphospecies when compared to all other species of Cribraria. The stability of the taxonomic characters of the species was confirmed by an examination of a number of specimens.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Biao Xiang ◽  
Xingxing Wang ◽  
Gang Wu ◽  
Yichen Xu ◽  
Menghan Wang ◽  
...  

AbstractNumerous factors can influence the force exerted by clear aligners on teeth. This study aimed to investigate the stability of the force delivered by two different material appliances. 90 clear aligners with 2 materials and three different activations were designed and fabricated. Then, a device was employed to measure the force generated by the two types of PET-G material appliances immersed in artificial saliva for 0, 3, 7, 10, 14 days. Scanning electron microscopy was applied to observe the morphologic alterations on the aligner surfaces, respectively. The forces generated by different activation appliance exhibited differently, 0.0 mm < 0.1 mm < 0.2 mm. In addition, increasing the immersion times and the orthodontic force also decreased, but the forces decreased differently. Compared with the forces of conventional PETG appliances with 0.20 mm activation, the modified PETG appliances with the same activation exhibited significantly higher mean force. When comparing the mean force for modified PETG appliances after 10 and 14 days with conventional PETG appliances, the delivery forces exhibited significant differences (P < 0.05). The force delivered by both materials decreased obviously following artificial saliva immersion, and the force generated by modified aligners exhibited better stability than conventional aligners.


2003 ◽  
Vol 18 (9) ◽  
pp. 2050-2054 ◽  
Author(s):  
Marcello Gombos ◽  
Vicente Gomis ◽  
Anna Esther Carrillo ◽  
Antonio Vecchione ◽  
Sandro Pace ◽  
...  

In this work, we report on the observation of Nd1Ba6Cu3O10,5 (Nd163) phase of the NdBaCuO system in melt-textured Nd123 bulk samples grown from a mixture of Nd123 and Nd210 phase powders. The observation was performed with polarized light optical microscopy and scanning electron microscopy–energy dispersive x-ray analyses. Images of the identified phase crystals show an aspect quite different from Nd422 crystals. Unexpectedly, Nd163 was individuated, even in “pure” Nd123 samples. Moreover, after long exposure to air, Nd163 disappeared completely in samples synthesized from powders containing Nd210. Thermogravimetry analyses of powders show that the stability of this phase in air is limited to temperatures higher than 900 °C, so Nd163 is unstable and highly reactive at room temperature. Moreover, an explanation of the observation of Nd163 in Nd210 free samples, based on the spontaneous formation of Nd163 phase in a Nd123 melt, is proposed.


2011 ◽  
Vol 418-420 ◽  
pp. 192-195
Author(s):  
Dong Qi Liu ◽  
Ying Liu ◽  
Shu Fa Han ◽  
Yu Feng Zhang ◽  
Cui Yu Yin

In this article we successfully prepared calamine / sodium alginate viscose fiber. Good dispersion and stability of the modified solution was prepared by dispersing calamine in alkaline solution of sodium alginate, and then mixed it with viscose spinning solution by spinning injection methods. Moreover, the stability of calamine / sodium alginate solution, the effect of concentration of calamine on the fiber properties is studied in this paper. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and physical mechanical performance are test to characterize the structure and the performance of the calamine / sodium alginate viscose fiber.


Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1197 ◽  
Author(s):  
Wei Li ◽  
Jie Wu ◽  
Xingui Cheng ◽  
Lanjuan Wu ◽  
Zhi Liu ◽  
...  

The impact of hydroxypropylsulfonation/caproylation on the adhesion of cornstarch to polylactic acid (PLA) fibers was investigated for ameliorating the applications such as PLA sizing. The hydroxypropylsulfonated and caproylated cornstarch (HCS) samples with different degrees of substitution (DS) were synthesized by a hydroxypropylsulfonation of acid-converted cornstarch (ACS) with 3-chloro-2-hydroxy-1-propanesulfonic acid sodium salt (CHPS-Na) and subsequently a caproylation with caproic anhydride (CA). The HCS granules were characterized by Fourier transform infrared spectroscopic and scanning electron microscopy. The adhesion was evaluated by measuring the bonding forces of the PLA roving impregnated. The mechanical behaviors of the adhesive layers were estimated by determining the properties of the films. The results of adhesion measurement were also analyzed especially through the wetting and spreading of the paste on the fiber surfaces, as well as the failure type, internal stress and mechanical behaviors of the adhesive layers among fibers. Additionally, apparent viscosity and its stability of the pastes were also determined. It was found that hydroxypropylsulfonation/caproylation was not only able to obviously improve the adhesion of ACS to PLA fibers, but also capable of further improving the adhesion of hydroxypropylsulfonated starch (HS) to the fibers. With the rise in the total DS, the adhesion gradually increased. The two substituents improved the wetting and spreading, reduced the internal stress, lowered the probabilities of interfacial failure and cohesive failure, decreased the film brittleness, and increased the van der Waals force at the interfaces. Moreover, the HCS samples with a stability of above 85% could meet the demand on the stability for sizing. Considering the experimental results of the adhesion and the analysis of the results, HCS showed potential in the application of PLA sizing.


Author(s):  
Robert Lotha ◽  
Aravind Sivasubramanian ◽  
Meenakshi Sundaram Muthuraman

Objective: The present study was aimed at the biosynthesis of silver nanoparticles (AgNPs) using aqueous extract of Euphorbia cyathophora leavesand testing their anticancer potential using HT-29 cell line model.Methods: Green synthesis of silver nanoparticles was obtained with the aqueous extract of E. cyathophora. The synthesized nanoparticles wereconfirmed initially by ultraviolet-visible spectroscopy. Further, scanning electron microscopy, transmission electron microscopy, and X-Ray diffractionstudies also ensured the presence of silver nanoparticles. Zeta potential studies revealed the stability of the silver nanoparticles.Results: Antioxidant and anticancer studies of the nanoparticles against HT-29 cell line exhibited remarkable results.Conclusion: This ensures that the synthesized nanoparticles play an important role in medicinal biology.


2012 ◽  
Vol 9 (75) ◽  
pp. 2551-2562 ◽  
Author(s):  
Marjorie S. Austero ◽  
Amalie E. Donius ◽  
Ulrike G. K. Wegst ◽  
Caroline L. Schauer

Chitosan (CS), the deacetylated form of chitin, the second most abundant, natural polysaccharide, is attractive for applications in the biomedical field because of its biocompatibility and resorption rates, which are higher than chitin. Crosslinking improves chemical and mechanical stability of CS. Here, we report the successful utilization of a new set of crosslinkers for electrospun CS. Genipin, hexamethylene-1,6-diaminocarboxysulphonate (HDACS) and epichlorohydrin (ECH) have not been previously explored for crosslinking of electrospun CS. In this first part of a two-part publication, we report the morphology, determined by field emission scanning electron microscopy (FESEM), and chemical interactions, determined by Fourier transform infrared microscopy, respectively. FESEM revealed that CS could successfully be electrospun from trifluoroacetic acid with genipin, HDACS and ECH added to the solution. Diameters were 267 ± 199 nm, 644 ± 359 nm and 896 ± 435 nm for CS–genipin, CS–HDACS and CS–ECH, respectively. Short- (15 min) and long-term (72 h) dissolution tests (T 600 ) were performed in acidic, neutral and basic pHs (3, 7 and 12). Post-spinning activation by heat and base to enhance crosslinking of CS–HDACS and CS–ECH decreased the fibre diameters and improved the stability. In the second part of this publication, we report the mechanical properties of the fibres.


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