1,726,439 research outputs found
A Variant Branching Pattern of the Aortic Arch: A Case Report.
Full text linkVariant aortic arch branching pattern may occur with different embryological mechanisms. We report on a variant aortic arch branching in a 41-year old Tanzanian male cadaver during dissection practice. The left common carotid artery was seen originating from the root of the brachiocephalic trunk and the left vertebral artery from the arch of the aorta proximal to the origin of the left subclavian artery. We discuss the relative literature, its potential embryologic development and clinical significance
FATIGUE CRACK GROWTH OF THE 8090 ALLOY UNDER OVERLOADING
No full textIn the present paper, the fatigue crack growth retardation following a single tensile overload applied to the 8090 alloy is studied and compared with results obtained from conventional aluminium alloys. The 8090 alloy exhibits a high retardation effect to overloads ; reasons for this good behaviour are given considering mechanical and fractographic aspects
Žetva strnih žita i uljane repice kombajnima New Holland CX 8090 i New Holland CR 9080
No full textThe article is focused on evaluation of the throughput, the fuel consumption and the performance of combine harvesters New Holland CX 8090 and New Holland CR 9080 during harvest of cereals and oilseeds rape. During harvest of winter wheat the throughput of New Holland CR 9080 combine harvester was 15,73 kg∙s-1. The throughput of New Holland CX 8090 was 13,27 kg∙s-1. The throughput of the combine harvester New Holland CR 9080, during harvest of winter wheat, was 12,60 kg∙s-1 for the New Holland CX 8090 it was 8,68 kg∙s-1. The fuel consumption of New Holland CR 9080 was 17,3l·ha-1 during harvest of winter wheat and 16,4 l·ha-1 while harvesting winter oilseed rape. New Holland CX 8090 had consumption 16,5 l·ha-1 for winter wheat and 15,9 l·ha-1 for winter oilseed rape. General operational performance pW07 during harvest of winter wheat was, for the New Holland CR 9080, 4,26 l·ha-1, weight operational performance mW07 was equal to 21,91 t.h-1. For harvesting wheat with New Holland CX 8090 the general operational performance pW07 was 3,70 ha.h-1 and the weight operational performance mW07 was 19,03 t.h-1. While harvesting oilseed rape the surface operational performance pW07 for CR 9080 was 3,13 ha.h-1, for CX 8090 it was 2,79 ha.h-1. The weight operational performance, of the combine harvester New Holland CR, mW07 was 10,00 t.h-1, the combine harvester CX 8090 had mW07 equal 8,90 t.h-1.Rad se bavi ocenjivanjem protoka, potrošnje goriva i performansi kombajna New Holland CX 8090 i New Holland CR 9080 u žetvi strnih žita i uljane repice. U žetvi ozime pšenice protok kod New Holland CR 9080 bio je 15,73 kg∙s-1. Protok kod New Holland CX 8090 bio je 13,27 kg∙s-1. Protok kod New Holland CR 9080 u žetvi ozime pšenice bio je 12,60 kg∙s-1, a kod New Holland CX 8090 8,68 kg∙s-1. Potrošnja goriva kod New Holland CR 9080 bila je 17,3l·ha-1 u žetvi ozime pšenice i 16,4 l·ha-1 u žetvi ozime uljane repice. New Holland CX 8090 imao je potrošnju od 16,5 l·ha-1 kod žetve ozime pšenice i 15,9 l·ha-1 pri žetvi uljane repice. Opšte radne performanse pW07 pri žetvi ozime pšenice bile su, kod New Holland CR 9080, 4,26 l·ha-. Pri žetvi žita sa New Holland CX 8090 opšte performance bile su pW07 3,70 ha.h-1
A quantitative interpretation of DSC experiments on quenched and aged SiCp reinforced 8090 alloys
No full textDSC curves of the quenched monolithic 8090 alloy and the 8090 MMC have been used to obtain values for the heats of formation of GPB zones, delta' and S phase. Using these ?H values and a correction for overlap of effects, the DSC curves of the aged alloys have been interpreted in terms of amounts of precipitates present. The presented interpretations are consistent with previous microstructural investigations. The solvus of GPB zones and of S phase in 8090 alloys has been obtained. Significant amounts of GPB zones are formed in the monolithic alloy, whilst the addition of SiC particles greatly reduces the amount of GPB zones formed
DEVELOPMENT OF SUPERPLASTIC 8090 AND 8091 SHEET
No full textThe paper considers the superplastic forming of the alloys Lital 8090 and Lital 8091 after processing by a route designed to confer superplastic properties. Examples of the components that can be fabricated by superplastic forming are shown and the properties that can be achieved in such components after different heat treatment procedures are given. Lital 8091 possesses somewhat better forming characteristics and is capable of achieving appreciably higher strengths in the formed product. However, the alloy is relatively quench sensitive and reasonably rapid cooling is necessary to achieve the maximum properties. Lital 8090 has somewhat reduced forming capabilities and can only achieve lower strength. However, it is less quench sensitive and near to full strength properties can be achieved by air cooling from the solution treatment temperature
The Strength and Fracture Behaviour of Diffusion Bonded Joints in Al-Li(8090) Alloy Sheet
No full textSolid state and transient liquid phase diffusion bonded joints have been made between Al-Li 8090 alloy and 8090 alloy/SiC particulate metal matrix composite. In this paper some shear and peel strengths are reported and the factors that affect the strength and fracture behaviour are discussed. Comparisons are made with other published data for bonded joints in Al-Li alloys.</jats:p
Investigations on serrated flow in 8090 Al alloy and 8090 Al-SiCp composites occurring during dynamic ultra low load micro hardness (DUH) indentation.
No full textOccurrence of plastic instabilities during depth sensing indentation in 8090 Al alloy and 8090 Al-SiCp composites containing 8 and 15 vol.% of SiC particles have been investigated by dynamic ultra low load micro hardness (DUH) technique. The unreinforced alloy shows instabilities (serrations) in the load-displacement curve in the as-extruded (AE) and solution-treated conditions. However, the magnitude of serrations becomes negligible after ageing. Al-Li-8% SiC composite shows signs of serrations in the soln.-treated condition. On the other hand, Al-Li-15% SiC composite shows almost no or negligible serrated flow in all the conditions (as-extruded, solution-treated, and aged)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
FATIGUE AND CORROSION FATIGUE OF 8090 Al-Li-Cu-Mg ALLOY
No full textThe fatigue resistance of metals can be profoundly affected by the environmental reactions that change crack initiation and propagation processes. These corrosion fatigue processes can occur in high strength aluminium alloys in aircraft, which frequently encounter salt spray and high humidity environments. For this reason, the fatigue behaviour of 8090-T6 alloy in the form of 25mm thick plate has been investigated in both air and an aerated 2.5% NaCl solution. Results are compared to a conventional high strength aluminium alloy, 2014-T6. Fatigue crack initiation and propagation data are presented for different crack orientations and mean stress levels. The slightly lower fatigue strength of 8090-T6 in air is attributed to earlier crack initiation. The fatigue crack propagation behaviour of 8090-T6 is shown to be superior to that of 2014-T6 at low to intermediate levels of ƊK, under both environmental conditions. The mechanisms associated with fatigue crack initiation and propagation, and environmental effects, are discussed
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