Search results for "Steady-state"
showing 9 items of 29 documents
Steady-state dynamic response of various hysteretic systems endowed with fractional derivative elements
2019
In this paper, the steady-state dynamic response of hysteretic oscillators comprising fractional derivative elements and subjected to harmonic excitation is examined. Notably, this problem may arise in several circumstances, as for instance, when structures which inherently exhibit hysteretic behavior are supplemented with dampers or isolators often modeled by employing fractional terms. The amplitude of the steady-state response is determined analytically by using an equivalent linearization approach. The procedure yields an equivalent linear system with stiffness and damping coefficients which are related to the amplitude of the response, but also, to the order of the fractional derivativ…
Anomalous diffusion and nonlinear relaxation phenomena in stochastic models of interdisciplinary physics
2020
The study of nonlinear dynamical systems in the presence of both Gaussian and non-Gaussian noise sources is the topic of this research work. In particular, after shortly present new theoretical results for statistical characteristics in the framework of Markovian theory, we analyse four different physical systems in the presence of Levy noise source. (a) The residence time problem of a particle subject to a non-Gaussian noise source in arbitrary potential profile was analyzed and the exact analytical results for the statistical characteristics of the residence time for anomalous diffusion in the form of Levy flights in fully unstable potential profile was obtained. Noise enhanced stability …
DFT study on the cycloreversion of thietane radical cations.
2011
The molecular mechanism of the cycloreversion (CR) of thietane radical cations has been analyzed in detail at the UB3LYP/6-31G* level of theory. Results have shown that the process takes place via a stepwise mechanism leading to alkenes and thiobenzophenone; alternatively, formal [4 + 2] cycloadducts are obtained. Thus, the CR of radical cations 1a, b(center dot+) is initiated by C2-C3 bond breaking, giving common intermediates INa,b. At this stage, two reaction pathways are feasible involving ion molecule complexes IMCa,b (i) or radical cations 4a,b(center dot+) (ii). Calculations support that 1a(center dot+) follows reaction pathway (leading to the formal [4 + 2] cycloadducts 5a). By cont…
''High-Intensity Interval Training in Cardiac Rehabilitation''
2012
Guiraud, Thibaut | Nigam, Anil | Gremeaux, Vincent | Meyer, Philippe | Juneau, Martin | Bosquet, Laurent; International audience; ''High-intensity interval training (HIIT) is frequently used in sports training. The effects on cardiorespiratory and muscle systems have led scientists to consider its application in the field of cardiovascular diseases. The objective of this review is to report the effects and interest of HIIT in patients with coronary artery disease (CAD) and heart failure (HF), as well as in persons with high cardiovascular risk. A non-systematic review of the literature in the MEDLINE database using keywords 'exercise', 'high-intensity interval training', 'interval training'…
The effect of high-intensity interval exercise program on blood lipids and hormones in recreationally active adults
2015
Johdanto. Tyypin 2 diabetes sekä verenkieroelimistön sairaudet ovat yleistyneet ja niiden tehokkaimpana ehkäisynä pidetään liikuntaa. Suomessa ihmiset eivät noudata liikuntasuosi-tuksia ja syyksi inaktiivisuuteen sanotaankin olevan ajan ja motivaation puute. Korkeate-hoinen intervalliharjoittelu on ollut suosittua siksi, että se säästää aikaa ja sen vaikutuksien terveyteen ja kuntoon ajatellaan olevan vähintäänkin samanlaiset kun aerobisen harjoittelun. Tämän tutkimuksen tarkoituksena oli tutkia onko kahden erityyppisen intervalliharjoittelun (juoksu ja kuntopiiri) välillä eroja veren lipideissä ja hormoneissa, kun työmäärä ja intensiteetti pysyvät samana. Tällä hetkellä tutkimuksia tästä a…
Comparison of the effects of high-intensity interval running, high-intensity interval circuit training and steady-state running on body composition a…
2015
Introduction. The measurement of body composition is important for several reasons, but nowadays when obesity and overweight are common problems all over the world even more attention should be given to body composition. Excess amount of fat is itself a risk for health, but it also predisposes to many diseases, one of which is diabetes. It has been shown that with regular physical activity and exercise the body composition and body’s glucose regulation can be improved. In common activity guidelines the amount of traditional endurance and resistance training takes hours per week to perform to fill the recommendations. However, since it has been shown that one of the most common reasons for n…
Anthrazyklin-induzierte Kardiotoxizität: MRT des Herzens bei Kindern und Jugendlichen mit malignen Erkrankungen
2004
Purpose: Quantification of left and right ventricular function using MRI in young cancer patients treated with cardiotoxic anthracyclines. Materials and Methods: Twenty-eight patients (mean age 16.4 years) underwent cardiac MRI at 1.5 T. The study protocol consisted of morphologic T2-weighted images with fat suppression and cine steady-state free precession sequences (SSFP) for functional analysis. Seven patients were examined at the end of chemotherapy, two of them also repeatedly during therapy, and 21 patients following an average period of three years after finishing chemotherapy (range one month - 20 years) Results: The end-systolic volume index increased and the ejection fraction of t…
Kardio-MRT
2004
Since initial reports in the early 1990s cardiac magnetic resonance imaging (CMR) has matured and is likely to become an established method for routine cardiac diagnostics. The development of faster gradient-echo sequences and stronger magnetic fields has led to improved temporal and spatial resolution. Myocardial viability can be examined by morphological and functional analysis. Contrast enhanced MRI (ceMRI), perfusion measurements and regional wall motion analysis are the major diagnostic tools. The ability to image in arbitrary double oblique planes provides comprehensive visualization of the heart. The introduction of the MR navigator technique allowed for free-breathing motion correct…
Quantifying Intermodal Distraction by Emotion During Math Performance: An Electrophysiological Approach
2019
Emotionally engaging stimuli are powerful competitors for limited attention capacity. In the cognitive neuroscience laboratory, the presence of task-irrelevant emotionally arousing visual distractors prompts decreased performance and attenuated brain responses measured in concurrent visual tasks. The extent to which distraction effects occur across different sensory modalities is not yet established, however. Here, we examined the extent and time course of competition between a naturalistic distractor sound and a visual task stimulus, using dense-array electroencephalography (EEG) recordings from 20 college students. Steady-state visual evoked potentials (ssVEPs) were quantified from EEG, e…