Effects of stress changes after demagnetization on magnetization curves and domain wall motions in a grain-oriented Si–Fe sheet

With the popularity of step-stress accelerated life testing, researchers are exploring more possibilities for models that relate the life distributions under different stress levels. Cumulative risk model assumes that the effects of stress changes have a lag period before they are fully observed, which guarantees the continuity of the hazard rate function. This paper studies the cumulative risk model for Lomax distribution with step-stress experiments. For maximum likelihood estimation, Newton-Rapson method is adopted to get point estimates. Meanwhile, the asymptotic normality of the maximum likelihood estimator is used to obtain asymptotic confidence intervals. For Bayesian estimation, point estimates and highest posterior density credible intervals under squared error loss function with informative prior and non-informative prior are derived using Metropolis-Hastings method and Metropolis-Hastings within Gibbs algorithm. To evaluate the effects of stress change time and the length of lag period, as well as the performance of different methods, numerical simulations are conducted. Then a real nanocrystalline data set is analyzed.

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The effects of psychosocial stress on intergroup resource allocation

Scientific Reports ◽

10.1038/s41598-019-54954-w ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 5

Author(s):

Adam Schweda ◽

Nadira Sophie Faber ◽

Molly J. Crockett ◽

Tobias Kalenscher

Keyword(s):

Social Preferences ◽

Social Dilemma ◽

Opposite Pattern ◽

Physiological Factors ◽

Prosocial Motives ◽

Tend And Befriend ◽

Stress Changes ◽

Effects Of Stress ◽

Other Regarding ◽

Fight Or Flight

AbstractStress changes our social behavior. Traditionally, stress has been associated with “fight-or-flight” – the tendency to attack an aggressor, or escape the stressor. But stress may also promote the opposite pattern, i.e., “tend-and-befriend” – increased prosociality toward others. It is currently unclear which situational or physiological factors promote one or the other. Here, we hypothesized that stress stimulates both tendencies, but that fight-or-flight is primarily directed against a potentially hostile outgroup, moderated by rapid-acting catecholamines, while tend-and-befriend is mainly shown towards a supportive ingroup, regulated by cortisol. To test this hypothesis, we measured stress-related neurohormonal modulators and sex hormones in male and female participants who were exposed to a psychosocial stressor, and subsequently played an intergroup social dilemma game in which they could reveal prosocial motives towards an ingroup (ingroup-love) and hostility towards an outgroup (outgroup-hate). We found no significant effects of stress on social preferences, but stress-related heart-rate increases predicted outgroup-hostile behavior. Furthermore, when controlling for testosterone, cortisol was associated with increased ingroup-love. Other-regarding behavior was overall higher in male than female participants. Our mixed results are of interest to scholars of the effects of stress on prosocial and aggressive behavior, but call for refinement in future replications.

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Critical Period for Stability of an Excavated Slope in Clay Soil

Canadian Geotechnical Journal ◽

10.1139/t74-061 ◽

1974 ◽

Vol 11 (4) ◽

pp. 620-623 ◽

Cited By ~ 5

Author(s):

T. Cameron Kenney ◽

Saif Uddin

Keyword(s):

Pore Water ◽

Safety Factor ◽

Critical Period ◽

Clay Soil ◽

Water Pressure ◽

Stability Study ◽

Stress Changes ◽

Pore Water Pressures ◽

Effects Of Stress

Bishop and Bjerrum have hypothesized that the critical period for stability of a slope excavated in weak clay soil would not occur at the end of the excavation period but, rather, would occur some time after completion of the excavation when the pore-water pressures in the slope corresponded to natural seepage conditions; for natural seepage conditions the pore-water pressures would no longer be influenced by the effects of stress changes in the soil caused by excavation of the slope. Evidence in support of this hypothesis will be presented in the form of a stability study of an excavated slope along the Kimola Canal in Finland. It will be shown from the results of stability calculations, based on measured pore-water pressures, that the safety factor of the slope decreased immediately after excavation was completed and that the slope failed some time later when the water-pressure conditions were most adverse to stability.

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Circumferential permeability in nonmagnetostrictive amorphous wires

Journal of Materials Research ◽

10.1557/jmr.1996.0313 ◽

1996 ◽

Vol 11 (10) ◽

pp. 2486-2489 ◽

Cited By ~ 25

Author(s):

M. L. Sanchez ◽

R. Valenzuela ◽

M. Vazquez ◽

A. Hernando

Keyword(s):

Domain Wall ◽

Current Amplitude ◽

Complex Permeability ◽

Equivalent Circuits ◽

Magnetization Curves ◽

Frequency Range ◽

Impedance Response ◽

Amorphous Wires ◽

Circular Field ◽

Magnetization Processes

Real and imaginary components of the impedance response on Co68.1Fe4.4B15Si12.5 amorphous as-cast wires were measured in the 100 Hz-100 kHz frequency range and 0.05–30 mA (RMS) current amplitude, at axial dc fields of 0 and 4800 A/m. From these data, plots of circumferential complex permeability as a function of circular field, as well as magnetization curves, were derived. Results are analyzed in terms equivalent circuits, which allows a resolution of domain wall and rotational contributions to the circumferential magnetization processes.

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Nd Rich Nd-Fe-B Tailored for Maximum Coercivity

MRS Proceedings ◽

10.1557/proc-577-247 ◽

1999 ◽

Vol 577 ◽

Cited By ~ 1

Author(s):

Er. Girt ◽

Kannan M. Krishnan ◽

G. Thomas ◽

C. J. Echer ◽

Z. Altounian

Keyword(s):

Domain Wall ◽

Coercive Field ◽

Magnetization Curves ◽

Pinning Mechanism ◽

Initial Magnetization ◽

Domain Wall Pinning

ABSTRACTThe coercive field, He, in rapidly quenched Nd-Fe-B was found to increase for samples with excess of Nd. In addition, Hc, strongly depends on the Fe/B ratio, increasing from 1.67 T for Fe/B = 1.07 to 2.05 T for Fe/B = 14.6 in Nd30(Fe,B)70. The increase in Hc seems to correlate with an increase of the γ-Nd phase in the sample. The initial magnetization curves of Nd30(Fe,B)70 show that the domain wall pinning plays a more important role as the Fe/B ratio increases. Thus, γ-Nd may play an important role in promoting a pinning mechanism. The excess of Nd in rapidly quenched Nd-Fe-B samples was also found to promote growth of Nd2Fe14B grains elongated in shape.

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Electron Microscopy of Graphite Intercalation Compounds

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055564 ◽

1982 ◽

Vol 40 ◽

pp. 544-545

Author(s):

G. Timp ◽

L. Salamanca-Riba ◽

L.W. Hobbs ◽

G. Dresselhaus ◽

M.S. Dresselhaus

Keyword(s):

Electron Microscopy ◽

Phase Transitions ◽

Domain Wall ◽

Intercalation Compounds ◽

Lattice Plane ◽

Wall Model ◽

Graphite Intercalation Compounds ◽

Fundamental Symmetry ◽

Graphite Intercalation

Electron microscopy can be used to study structures and phase transitions occurring in graphite intercalations compounds. The fundamental symmetry in graphite intercalation compounds is the staging periodicity whereby each intercalate layer is separated by n graphite layers, n denoting the stage index. The currently accepted model for intercalation proposed by Herold and Daumas assumes that the sample contains equal amounts of intercalant between any two graphite layers and staged regions are confined to domains. Specifically, in a stage 2 compound, the Herold-Daumas domain wall model predicts a pleated lattice plane structure.

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The direct determination of magnetic domain wall profiles using a split detector STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100109471 ◽

1978 ◽

Vol 36 (1) ◽

pp. 466-467

Author(s):

J.N. Chapman ◽

P.E. Batson ◽

E.M. Waddell ◽

R.P. Ferrier

Keyword(s):

Electron Microscope ◽

Domain Wall ◽

Transmission Electron Microscope ◽

Domain Walls ◽

Photographic Plate ◽

Magnetic Domain ◽

Direct Determination ◽

Quantitative Information ◽

Scanning Transmission Electron Microscope ◽

Transmission Electron

By far the most commonly used mode of Lorentz microscopy in the examination of ferromagnetic thin films is the Fresnel or defocus mode. Use of this mode in the conventional transmission electron microscope (CTEM) is straightforward and immediately reveals the existence of all domain walls present. However, if such quantitative information as the domain wall profile is required, the technique suffers from several disadvantages. These include the inability to directly observe fine image detail on the viewing screen because of the stringent illumination coherence requirements, the difficulty of accurately translating part of a photographic plate into quantitative electron intensity data, and, perhaps most severe, the difficulty of interpreting this data. One solution to the first-named problem is to use a CTEM equipped with a field emission gun (FEG) (Inoue, Harada and Yamamoto 1977) whilst a second is to use the equivalent mode of image formation in a scanning transmission electron microscope (STEM) (Chapman, Batson, Waddell, Ferrier and Craven 1977), a technique which largely overcomes the second-named problem as well.

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The need of electron microscopy in the study of domains and domain walls in ferroelectrics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170487 ◽

1994 ◽

Vol 52 ◽

pp. 550-551

Author(s):

Wenwu Cao

Keyword(s):

Domain Wall ◽

Domain Walls ◽

High Mobility ◽

Continuum Theory ◽

Polarization Vector ◽

Ferroelectric Materials ◽

Dielectric Constants ◽

Nonlocal Coupling ◽

Cubic Symmetry ◽

Gradient Energy

Domain structures play a key role in determining the physical properties of ferroelectric materials. The formation of these ferroelectric domains and domain walls are determined by the intrinsic nonlinearity and the nonlocal coupling of the polarization. Analogous to soliton excitations, domain walls can have high mobility when the domain wall energy is high. The domain wall can be describes by a continuum theory owning to the long range nature of the dipole-dipole interactions in ferroelectrics. The simplest form for the Landau energy is the so called ϕ model which can be used to describe a second order phase transition from a cubic prototype,where Pi (i =1, 2, 3) are the components of polarization vector, α's are the linear and nonlinear dielectric constants. In order to take into account the nonlocal coupling, a gradient energy should be included, for cubic symmetry the gradient energy is given by,

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