scholarly journals Influence of Electrolytical Oxidising of Silumine Surfaces on the Quality of Bonding with Epoxy Resin

2016 ◽  
Vol 61 (3) ◽  
pp. 1601-1606
Author(s):  
A. Posmyk ◽  
M. Cholewa ◽  
J. Wieczorek ◽  
D. Scelina

Abstract The article presents the preparation process of AC-AlSi12 aluminum alloy surface by application of anodic oxidation method. The method enables the formation of a porous oxide layer (Al2O3) which generates the substrate of durable adhesive bond with an epoxy resin. It also presents the influence of the form of silicon precipitates in the modified alloy upon anodizing process, uniform structure and thickness of the oxide layer as well as the topography of its surface which is expected to improve adhesion of the resin and silumin. The paper describes how the position of oxidized surface against the negative electrode influences the coating structure. The studied silumins are intended to form the material for casting of 3 dimensional objects whose parts will change the distribution of electric field strength that may cause non-uniform structure of the coating.

Author(s):  
Wah Chiu ◽  
Michael Sherman ◽  
Jaap Brink

In protein electron crystallography, both low dose electron diffraction patterns and images are needed to provide accurate amplitudes and phases respectively for a 3-dimensional reconstruction. We have demonstrated that the Gatan 1024x1024 model 679 slow-scan CCD camera is useful to record electron diffraction intensities of glucose-embedded crotoxin complex crystal to 3 Å resolution. The quality of the electron diffraction intensities is high on the basis of the measured intensity equivalence ofthe Friedel-related reflections. Moreover, the number of patterns recorded from a single crystal can be as high as 120 under the constraints of radiation damage and electron statistics for the reflections in each pattern.A limitation of the slow-scan CCD camera for recording electron images of protein crystal arises from the relatively large pixel size, i.e. 24 μm (provided by Gatan). The modulation transfer function of our camera with a P43 scintillator has been determined for 400 keV electrons and shows an amplitude fall-off to 0.25 at 1/60 μm−1.


2015 ◽  
Vol 669 ◽  
pp. 150-157
Author(s):  
Peter Michal ◽  
Alena Vagaská ◽  
Miroslav Gombár

Paper tracks experimentally confirmed relationship between chemical composition of electrolyte and resulting surface finish quality of created oxide layer during the process of anodic oxidation of aluminium. Examined chemical factors were: concentrations of sulphuric acid, oxalic acid, boric acid and sodium chloride. Aggressive effects of electrolyte were chosen as indicator of resulting layer quality – presence and extent of etching of used substrate sample.


2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Virgil Penta ◽  
Cristian Pirvu ◽  
Ioana Demetrescu

The main objective of the current paper is to show that electrochemical impedance spectroscopy (EIS) could be a method for evaluating and predicting of ProTaper rotary file system clinical lifespan. This particular aspect of everyday use of the endodontic files is of great importance in each dental practice and has profound clinical implications. The method used for quantification resides in the electrochemical impedance spectroscopy theory and has in its main focus the characteristics of the surface titanium oxide layer. This electrochemical technique has been adapted successfully to identify the quality of the Ni-Ti files oxide layer. The modification of this protective layer induces changes in corrosion behavior of the alloy modifying the impedance value of the file. In order to assess the method, 14 ProTaper sets utilized on different patients in a dental clinic have been submitted for testing using EIS. The information obtained in regard to the surface oxide layer has offered an indication of use and proves that the said layer evolves with each clinical application. The novelty of this research is related to an electrochemical technique successfully adapted for Ni-Ti file investigation and correlation with surface and clinical aspects.


Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 962 ◽  
Author(s):  
Usman Ali Khan ◽  
Sang Sun Lee

Device-to-Device (D2D) communication is the major enabler of Vehicle-to-Everything communication in 3rd Generation Partnership Project (3GPP) Release 14. The user equipment/device can engage either in direct communication with the infrastructure, use a relay node, or it can communicate directly with another device with or without infrastructure support. The user equipment can be either a hand-held cellular device or a moving vehicle. The coexistence of cellular user equipment with the vehicular user equipment imposes different Quality of Service (QOS) requirements due to the rapid mobility of the vehicles and interference. Resource allocation is an important task by which the user equipment is allocated the required resources based on different QOS parameters. In this paper, we introduced the case of three types of users which share uplink resources: two types of vehicular users, and a third user that acts as a handheld cellular phone, which is nearly static. By keeping in mind, the differential QOS requirements for the three types of users, we have calculated the optimum power and then applied a 3-dimensional graph-based matching and hypergraph coloring based resource block (RB) allocation.


2019 ◽  
Vol 4 (2) ◽  
pp. 247301141983850 ◽  
Author(s):  
Justin J. Ray ◽  
Andrew J. Friedmann ◽  
Andrew E. Hanselman ◽  
Justin Vaida ◽  
Paul D. Dayton ◽  
...  

Hallux valgus is a common condition that results from a complex positional deformity of the first ray. The bunion or medial prominence that results from the lateral deviation and pronation of the hallux is only one component of the 3-dimensional deformity. Hallux valgus can lead to considerable pain and altered joint mechanics. The precise biomechanical etiology remains under debate. Predisposing factors include female sex, age, constricting footwear, and family history. Metatarsus adductus, equinus contracture, hammertoe deformity, and pes planus often coexist with hallux valgus. Nonoperative treatment involves patient education, shoe modifications, toe pads and positioning devices, and activity modifications. Surgery is considered in patients who fail nonoperative treatment with the goal of pain relief, correction of the deformity, improved first ray stability, and improved quality of life. More than 100 different procedures have been described to treat hallux valgus; they include combinations of soft tissue balancing, metatarsal osteotomies, and fusion of either the metatarsophalangeal (MTP) or tarsometatarsal (TMT) joint. The choice of procedures depends on the severity and location of the deformity as well as surgeon preference. Recent advances in operative techniques include minimally invasive surgery and correction of rotational deformity.


Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 578 ◽  
Author(s):  
Guodong Zhu ◽  
Shouren Wang ◽  
Wei Cheng ◽  
Gaoqi Wang ◽  
Wentao Liu ◽  
...  

The surface of the aluminum alloy is prone to oxidation, which in turn affects the quality of the weld. The 5A12 aluminum alloy was cleaned by acousto-optic Q-switched diode-pumped Nd:YAG laser and the effects of different laser powers and different cleaning speeds on the surface roughness, microstructure, element content, microhardness, residual stress and corrosion resistance of aluminum alloy were investigated. The results show that when the power is 98W and the cleaning speed is 4.1 mm/s, the effect of Nd: YAG laser on the removal of oxide film on 5A12 aluminum alloy surface is the most effective. After laser cleaning, the smoothness and strength of aluminum alloy surface can be effectively improved. However, as a major element in 5A12 aluminum alloy, the content of magnesium decreased. At the same time, the residual tensile stress was generated on the surface of the aluminum alloy after cleaning, and the corrosion resistance slightly decreased.


2016 ◽  
Vol 149 ◽  
pp. 512-519 ◽  
Author(s):  
Alena Vagaská ◽  
Erika Fechová ◽  
Peter Michal ◽  
Miroslav Gombár

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Christian Hopmann ◽  
Suveni Kreimeier ◽  
Jan Keseberg ◽  
Carsten Wenzlau

Lightweight construction is a central technology in today’s industrial production. One way to achieve the climate goals is the production of hybrid compounds of metal and plastic. The manufacturing process for these hybrid parts can be divided into in-mold assembly and postmold assembly. The postmold assembly includes thermal joining by laser, which is applied in the context of this paper. For the investigations, four plastics (MABS, PA6.6-GF35, PP, and PC), which differ in their properties, and three metals (unalloyed steel, stainless steel, and aluminum) are combined and analyzed. These materials have been used, since they have a huge significance in the automotive industry. Preliminary studies showed that an adhesive bond between the two materials is achieved using metal with a structured surface. According to these studies, three structuring processes for metals (selective laser melting (SLM), NRX, and a welded metallic tissue) are tested. The quality of the material/structure combinations is tested in tensile-shear-tests, microscopy images, and alternating climate tests. Compounds with SLM-Structure achieve highest strength, while compounds with aluminum are much more complex to manufacture.


Author(s):  
Jun Doi ◽  
Atsushi Yamada ◽  
Keisuke Inoue

Finite element analysis has become a key technology for a design process of manufacturing industry. A hexahedral mesh is focused, because using a hexahedral mesh increases the quality of analysis. However it is very difficult problem to generate high quality hexahedral meshes, and there are many challenging research topics. Our goal is to develop a method to generate hexahedral meshes automatically to general volumes. Our method uses an intermediate model to recognize the input volume. The intermediate model is defined in the integer 3-dimensional space, and faces of the intermediate model are vertical to coordinate axes. Hexahedral mesh is generated by dividing the intermediate model into integer grids, and blocks of grids are projected into original volume. In this paper, we describe the method to generate a topology of the intermediate model. We use face clustering technique to generate the topology of the intermediate model. The faces of the input volume are clustered into 6 types; according to 3 coordinate axes and its direction, and clustered faces will be the faces of the intermediate model.


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