Rate Of Decrease In Amplitude Research Articles

N.D. Kondratiev Long Wave Models for Three Large European Countries

The purpose of this study is to analyze the similarities and differences in the structure of N. D. Kondratiev long waves in the economies of the three largest European countries: Germany, France and Great Britain. It is assumed that the main trend in the dynamics of the GDP of these countries – ​is the trend associated precisely with changes in technology, and not with the influence of ones or others exogenous factors – ​can be represented in the form of a superposition of long Kondratiev waves represented by a periodic function, the values of which at a given time determines the amount of value added produced over the previous time interval. Each wave is characterized by four parameters: time, length of its period, magnitude of the initial amplitude and rate of amplitude decrease. In addition, such characteristics of long waves as the duration of their latency period, the time of their entry into leading positions and duration of their leadership relative to the previous and subsequent technological waves are calculated. Five long Kondratiev waves are considered, the parameters of which are estimated in such a way as to obtain the best description of the dynamics of the GDP of a given country in terms of the deviation of the model from this dynamics. As an estimate of GDP, its values measured in international dollars (Geary–Khamis dollars) for the period from 1790 to 2020 are considered. The calculations showed that in some parameters there is a similarity in the structure of technological waves in these countries, while in others there are differences in the dynamics of their occurrence and development. In the final part of the article, the characteristics of long waves for three European countries are compared with the characteristics of long waves in the US economy over the same time period obtained in previous studies. It is also shown that the leadership durations of long waves obtained in these calculations coincide with the theoretical estimates of the periods of long waves by N. D. Kondratiev.

Dynamic and Static Compression Tests for Paper Honeycomb Cores and Absorbed Energy.

In order to investigate the effect of loading rate on the strength and the absorbed energy of paper honeycomb cores, a series of compression tests were carried out at quasi-static and dynamic rates. The specimens used are polypropylene(PP) and polyester(PET) thermoplastic honeycomb cores, which are usually called paper honeycomb cores. It was found that the peak stress and average crush stress increased with the increase of loading rate and was especially remarkable in the results of the PP core. The absorbed energy obtained from dynamic tests was also greater than that obtained at quasi-static rates. It was ascertained that the polyvinyl chloride(PVC) long tube was quite useful as a device for measuring stress waves in dynamic compression tests, if the characteristics of the wave propagation in the PVC tube are obtained by preliminary wave propagation experiments, specifically to determine the rate of decrease in amplitude and/or the propagation velocity.

Diffusion study in Ni xZr 1− x amorphous metallic alloys

The temperature effect of nickel self-diffusion in amorphous NiZr alloy has been determined from interdiffusion measurements by studying the rate of decrease in amplitude of composition-modulated thin films. Temperature and pressure effects of hafnium diffusion in amorphous Ni 54Zr 46 alloys have also been measured, given the zirconium self-diffusivity behaviour in this material, using secondary ion mass spectrometry (SIMS). Activation energies measured are 1.33 eV/at. for nickel diffusion and 0.76 eV/at. for hafnium diffusion. The dependence on pressure studied by annealing samples at 412°C, 10 h, under hydrostatic pressure from 0.02 to 0.96 GPa led to an activation volume of 8 Å 3/atom for hafnium diffusion in this amorphous alloy. These present results are then discussed with respect to possible diffusion mechanisms like point defects models and collective ‘models’ involving several atoms.

Experimental evaluation of delaminations in composite plates by the use of Lamb waves

The fundamental S 0 mode of Lamb waves can be used in testing for delaminations in plate material. By scanning over the surface beneath which a delamination lies, it is possible to measure the size of the delamination. The amplitude of the wave decreases over a delamination. It has been found that the phase velocity does not change significantly with the depth of delamination. The rate of decrease in amplitude of an individual pulse cycle was detected to vary with the depth of the delamination, being most sensitive to delaminations near the surface of the plate. This is particularly useful when sizing for defects close to the surface, where a normal-incidence pulse-echo ultrasonic method has problems, particularly when the depth of the defect or the back-wall echoes lie within the length of the transmitted ultrasonic pulse. The rate of change in signal amplitude over the delamination also depends on the surface area of the probe in contact with the specimen surface, i.e. a small probe is more receptive to the presence of a delamination. The technique has potential for faster c-scanning of a complete plate than the usual normal-incidence pulse-echo method.

Activation volume for the interdiffusion of Ag-Au multilayers

The activation volume ΔV for chemical diffusion in Ag50Au50 alloy has been determined from the pressure dependence of the rate of decrease in amplitude of composition-modulated thin films. Based on resistivity measurements, it is argued that the technique yields the bulk chemical diffusion coefficient, in close agreement with the experimental results. Eight measurements of the diffusion coefficient were made, four as a function of temperature (237–309 °C) at atmospheric pressure and four as a function of pressure (0–0.85 GPa) at constant temperature (269.5 °C). The samples, 2000–3000-Å-thick multilayers of alternating silver and gold, with periods between 72 and 160 Å, were made with a newly built UHV sputter-deposition apparatus. The bulk chemical interdiffusion activation energy (1.5 eV) and activation volume (0.72 Ω) agree with those expected from other interdiffusion and tracer measurements.

Numerical modelling of SHLgwaves in and near continental margins

SUMMARY The effect of transition regions between continental and oceanic structures on the propagation of L, waves from continental sources is examined. In particular, the attenuation due to variations in layer thickness in such transition regions is calculated and explained for a suite of simple models. The measured attenuation, due tq the geometry of the transition regions between the oceanic and continental structures within a partially oceanic path with source and receiver in a continental structure, is at most a factor of four for frequencies from 0.01 to 1 Hz. This is inadequate to explain the observed extinction of L, along such paths. This extinction has previously been attributed to the effects of the transition region geometry. The method used to calculate the results presented in this study is developed and its validity and accuracy are demonstrated. Propagator matrix seismograms are coupled into a Finite Element calculation to produce hybrid teleseismic SH mode sum seismograms. These hybrid synthetics can be determined for paths including any regional transition zone or other heterogeneity that exists as part of a longer, mostly plane-layered, path. Numerical results presented for a suite of transition models show distinct trends in each of the regions through which the wavefield passes. The wavefield passes through a continent-ocean transition region, then a region of oceanic structure, and finally through an ocean-continent transition region. When an L, wavefront passes through a continent-ocean transition, the amplitude and coda duration of the L, wave at the surface both increase. At the same time, much of the modal L, energy previously trapped in the continental crust is able to escape from the lower crust into the subcrustal layers as body waves. The magnitude of both these effects increases as the length of the transition region increases. When the wavefront passes through the region of oceanic structure further energy escapes from the crustal layer, and produces a decrease in L, amplitude at the surface. The rate of amplitude decrease is maximum near the transition region and decreases with distance from it. When the wavefield passes through the oceancontinent transition region a rapid decrease in the L, amplitude at the surface of the crust results. The energy previously trapped in the oceanic crustal layer spreads throughout the thickening crustal layer. Some of the body wave phases produced when the wavefield passes through the continent-ocean transition region are incident on the continental crust in the ocean-continent transition region. These waves are predominantly transmitted back into the crust. The other body wave phases reach depths below the depth of the base of the continental crust before reaching the ocean-continent transition and, thus, escape from the system.

The effects of flurazepam hydrochloride on brain electrical activity during sleep

To further evaluate the effects of flurazepam on EEG during sleep, following 7 nights of placebo baseline, flurazepam (30 mg) was administered to 6 young adult poor sleepers for 10 additional nights while 6 other young adult poor sleepers continued to receive placebo capsules in a double-blind paradigm. Three placebo follow-up nights were recorded 2–3 weeks post-treatment. Twelve good sleepers received only placebo capsules for the first 7 nights. Delta waves, 0.5–2 c/sec, and sleep spindles were counted on-line by a phasic detector. Delta activity was also analyzed off-line by PDP-12 computer for only the first 4 h of sleep and involved a comparison over stages of sleep. Click-evoked K-complexes during NREM sleep were analyzed for 6 good sleepers and 11 poor sleepers. Repeated use of flurazepam caused a gradual decrease in delta amplitude and count, and a gradual increase in sleep spindle rate. The decrease in delta amplitude was seen in all sleep stages, but the decrease was significant only during SWS and stage 2. The decrease in delta amplitude was significant by the 3rd drug night, but the rate of amplitude decrease tended to slow with continued treatment. The decrease in delta count was less pronounced and more gradual over drug nights than the rate of decrease in amplitude. Flurazepam also significantly reduced evoked K-complex amplitude but did not affect latency. Sleep spindle rate was significantly increased by drug night 5. Results of this study indicate that the reduction of SWS with flurazepam during the initial drug nights is due primarily to the decrease in delta amplitude, but, with continued use, the decrease in delta count also contributes to the decrease in stage 4 sleep.

Evoked potential amplitude change related to intelligence and arousal.

ABSTRACTUsing a sample of 94 adult subjects, relationships between measures of intelligence and the rate of decrease in amplitude of the average evoked potential (AEP) were examined in some detail. It was found that the rate of AEP amplitude decrease from a condition of high extrinsic inducement to activation to a condition of low extrinsic inducement to activation was significantly correlated with fluid intelligence (r= .24) and its subprocesses, but not with crystallized intelligence. This finding was interpreted as indicating that the AEP shift measure and the fluid intelligence measures indicate a kind of adaptive flexibility (or plasticity) of intellectual functioning. The results suggested that this is not a flexibility capacity that decreases significantly with aging in adulthood.