scholarly journals Superplasticity and Superplastic Forming

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 946
Author(s):  
Donato Sorgente

In both academic and industrial research endeavours, driving forces are essential to keep the interest alive for a specific topic [...]

2018 ◽  
Vol 28 (5) ◽  
pp. 1563-1565
Author(s):  
Havë Qarri ◽  
Jusuf Fejza

There are many theories about motivation. Different scholars have tried to find out why some people want to work and some do not, why some people are better than others and what motivates them to achieve results. There is one but a very simple recipe on how to motivate people. The motive depends on the individual, the situation or the people with whom we are working. Motivation theories can only be used as a tool. But commanders need to know when and how to use the right tool (theory).Motivation is a very specific topic and not very elaborate among us. Therefore, we took the courage to choose this subject as a course. In order to make the work as rich as possible we have used different literature."To win competitive advantage and survive in the global economy, managers must motivate their employees. Motivation is a complex psychological process in which demands and desires create driving forces that aim at achieving goals.


Author(s):  
J. I. Bennetch

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.


Author(s):  
P. R. Okamoto ◽  
N.Q. Lam ◽  
R. L. Lyles

During irradiation of thin foils in a high voltage electron microscope (HVEM) defect gradients will be set up between the foil surfaces and interior. In alloys defect gradients provide additional driving forces for solute diffusion since any preferential binding and/or exchange between solute atoms and mobile defects will couple a net flux of solute atoms to the defect fluxes. Thus, during irradiation large nonequilibrium compositional gradients can be produced near the foil surfaces in initially homogeneous alloys. A system of coupled reaction-rate and diffusion equations describing the build up of mobile defects and solute redistribution in thin foils and in a semi-infinite medium under charged-particle irradiation has been formulated. Spatially uniform and nonuniform damage production rates have been used to model solute segregation under electron and ion irradiation conditions.An example calculation showing the time evolution of the solute concentration in a 2000 Å thick foil during electron irradiation is shown in Fig. 1.


Author(s):  
A. Cziráki ◽  
E. Ková-csetényi ◽  
T. Torma ◽  
T. Turmezey

It is known that the formation of cavities during superplastic deformation can be correlated with the development of stress concentrations at irregularities along grain boundaries such as particles, ledges and triple points. In commercial aluminium alloys Al-Fe-Si particles or other coarse constituents may play an important role in cavity formation.Cavity formation during superplastic deformation was studied by optical metallography and transmission scanning electron microscopic investigations on Al-Mg-Si and Al-Mg-Mn alloys. The structure of particles was characterized by selected area diffraction and X-ray micro analysis. The volume fraction of “voids” was determined on mechanically polished surface.It was found by electron microscopy that strongly deformed regions are formed during superplastic forming at grain boundaries and around coarse particles.According to electron diffraction measurements these areas consist of small micro crystallized regions. See Fig.l.Comparing the volume fraction and morphology of cavities found by optical microscopy a good correlation was established between that of micro crystalline regions.


2013 ◽  
Vol 18 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Robert J. Barth

Abstract Scientific findings have indicated that psychological and social factors are the driving forces behind most chronic benign pain presentations, especially in a claim context, and are relevant to at least three of the AMA Guides publications: AMA Guides to Evaluation of Disease and Injury Causation, AMA Guides to Work Ability and Return to Work, and AMA Guides to the Evaluation of Permanent Impairment. The author reviews and summarizes studies that have identified the dominant role of financial, psychological, and other non–general medicine factors in patients who report low back pain. For example, one meta-analysis found that compensation results in an increase in pain perception and a reduction in the ability to benefit from medical and psychological treatment. Other studies have found a correlation between the level of compensation and health outcomes (greater compensation is associated with worse outcomes), and legal systems that discourage compensation for pain produce better health outcomes. One study found that, among persons with carpal tunnel syndrome, claimants had worse outcomes than nonclaimants despite receiving more treatment; another examined the problematic relationship between complex regional pain syndrome (CRPS) and compensation and found that cases of CRPS are dominated by legal claims, a disparity that highlights the dominant role of compensation. Workers’ compensation claimants are almost never evaluated for personality disorders or mental illness. The article concludes with recommendations that evaluators can consider in individual cases.


2005 ◽  
pp. 133-143 ◽  
Author(s):  
E. Balashova

The method of analyzing and modeling cyclical fluctuations of economy initiated by F. Kydland and E. Prescott - the 2004 Nobel Prize winners in Economics - is considered in the article. They proposed a new business cycle theory integrating the theory of long-run economic growth as well as the microeconomic theory of consumers and firms behavior. Simple version of general dynamic and stochastic macroeconomic model is described. The given approach which was formulated in their fundamental work "Time to Build and Aggregate Fluctuations" (1982) gave rise to an extensive research program and is still used as a basic instrument for investigating cyclical processes in economy nowadays.


2004 ◽  
pp. 129-140 ◽  
Author(s):  
M. Tretyakov

The article focuses on the analysis of the process of convergence of outsider and insider models of corporate governance. Chief characteristics of basic and intermediate systems of corporate governance as well as the changing role of its main agents are under examination. Globalization of financial and commodity markets, convergence of legal systems, an open exchange of ideas and information are the driving forces of the convergence of basic systems of corporate governance. However the convergence does not imply the unification of institutional environment and national institutions of corporate governance.


Author(s):  
Faridullah Bezhan

Wish Zalmiyan or the ‘Awaken Youth Party’ (AYP) was the first political party to operate openly in Afghanistan. It enjoyed support from the intelligentsia and the monarchical regime. The AYP’s key ideological elements were nationalism and constitutionalism. While they made the party popular with a segment of the ruling elite and the intelligentsia, they brought resentment from the religious establishment for which Islam was the only ideology to be followed and the Quran the only constitution the country needed. This chapter examines how, in the aftermath of World War II, most members of the urban Afghan educated class leaned towards nationalism and constitutionalism as the driving forces for new political dynamics and the progress of the country. It explores what type of nationalism the Wish Zalmiyan party was advocating.


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