Search results for "THD"
showing 10 items of 129 documents
Influence of the suspension of continued treatment with flurazepam and amobarbital on two discrimination learning schedules.
1977
The authors have studied the effect of the suspension of chronic treatment with flurazepam and amobarbital on the operant behavior of rats that for the first time were in the presence of two fixed-interval discrimination schedules. With the sound discrimination schedule, the responses emitted by the treated animals had characteristics similar to those of control animals. With the temporal discrimination schedule, though it is not possible to distinguish between learning rates, modifications in the intensity of the effect (increases in lever pressing) indicate that, considering the doses, the action of flurazepam is slight and that of amobarbital clear and statistically significant.
Harmonic reduction in CHB 13-level inverters by PAM fundamental-frequency strategy
2019
In this paper cascaded H-bridges (CHB) 13-level inverters are considered and a particular pulse amplitude modulation (PAM) strategy is introduced to mitigate or eliminate many harmonic components on the output voltage, in order to obtain low Total Harmonic Distortion (THD) factor. This procedure defines different dc voltage sources and sets of six switching angles, depending on an integer parameter $q$ belonging to the close interval $I=[11, 15]$ . The obtained THD doesn't depend on modulation index $m$ . The control of $m$ is made by changing the dc voltage sources that depend linearly on m, while the switching angles remain constant. An investigation about the role of the $q$ parameter on…
Convergence of nociceptive and non-nociceptive inputs onto spinal reflex pathways to the tibialis anterior muscle in humans
1998
The interaction of low-threshold mechanoreceptive and nociceptive inputs onto spinal neurones probably plays a major role in the pathophysiology of the clinical sign of allodynia. This phenomenon was investigated by modulation of the early component of the flexor reflex (FR) in the tibialis anterior (TA) muscle, elicited by electrical stimulation of the medial plantar nerve at the sole of the foot, by homotopically applied painful heat in humans. This early reflex with an electrical threshold of 2.7-fold the detection threshold and a mean afferent conduction velocity of 49 m s-1 is a non-nociceptive FR. When applying conditioning painful heat (46 degrees C) to the sole of the foot this refl…
Psychomotor and Motor Speed in Power Athletes Self-Administering Testosterone and Anabolic Steroids
1988
Abstract The effect of self-administered testosterone and anabolic steroids on psychomotor and motor speed were studied among five top-level power athletes. The experiment included a 26-week intensive strength training period in association with the use of exogenous hormones and a 6-week follow-up after drug withdrawal. Six athletes not using exogenous hormones served as a control group. The results indicated a similar, and in most cases insignificant, improvement (0–10%) in performance in both groups in both the simple and more complicated motor and psychomotor tests. Only in maximal vertical speed related to body weight was there more improvement in the experimental group, from 122.2 to 1…
Withdrawal of inhaled corticosteroids in COPD: A meta-analysis
2017
Background Conflicting findings exist on the benefit of withdrawal of inhaled corticosteroid (ICS) in chronic obstructive pulmonary disease (COPD). We performed a quantitative synthesis in order to assess real impact of ICS discontinuation in COPD patients. Methods We carried out a meta-analysis via random-effects model on the available clinical evidence to evaluate the effect of ICS discontinuation in COPD. Randomized clinical trials and observational real-life studies investigating the effects of ICS withdrawal on the risk of COPD exacerbation, lung function (forced expiratory volume in 1 s [FEV1]) and quality of life (St. George's Respiratory Questionnaire [SGRQ]) were identified by sear…
Incidence of Diabetes Following Ramipril or Rosiglitazone Withdrawal
2011
OBJECTIVE To examine the impact of withdrawing rosiglitazone and ramipril medication on diabetes incidence after closeout of the Diabetes REduction Assessment with ramipril and rosiglitazone Medication (DREAM) trial. RESEARCH DESIGN AND METHODS The 3,366 DREAM subjects at trial end who had not developed diabetes while taking double-blind study medication were transferred to single-blind placebo for 2 to 3 months before undergoing an oral glucose tolerance test. Glycemic status was analyzed for the trial plus washout period and for the washout period alone. RESULTS Following median (interquartile range) 71 (63–86) days drug withdrawal, overall glycemic status remained modestly improved in t…
Enhanced modulation strategy for 7-level voltage waveform in asymmetrical 5-level Cascaded H-Bridge Inverters
2022
The CHBMI performance optimization can be reached both with hardware and software solutions. Generally, asymmetrical configurations allow the extension of the voltage levels number and the implementation of an innovative modulation strategy allows for improving the performance in terms of harmonic distortion and conversion efficiency. This work is devoted to the development of a modulation strategy that allows improving the performance of an asymmetrical single-phase five-level Cascaded H-Bridge Inverter generating a 7-level voltage waveform. Thus, a digital approach and corresponding digital functions are presented. Subsequently, the impact of the dead time and the influence on the voltage…
Il ruolo del Consiglio europeo nella Brexit
2019
Il Consiglio europeo ha svolto un ruolo di primo piano nella Brexit. L’articolo cerca di spiegare che questo ruolo è stato più ampio rispetto a quello espressamente conferito dall’art. 50 TUE per affrontare poi due problemi: nello svolgere questo ruolo il Consi- glio europeo ha agito solo come istituzione dell’Unione europea o anche come vertice di capi Stato? E ha rispettato il principio dell’equilibrio istituzionale? The European Council has been playing a leading role in Brexit procedure. This article aims at showing how this role does not simply reflect the powers explicitly assigned to the European Council under Article 50 TEU. Two more questions are addressed: In performing its role h…
Substituent effects in trans-p,p'-disubstituted azobenzenes: X-ray structures at 100 K and DFT-calculated structures.
2014
The crystal and molecular structures of twopara-substituted azobenzenes with π-electron-donating –NEt2and π-electron-withdrawing –COOEt groups are reported, along with the effects of the substituents on the aromaticity of the benzene ring. The deformation of the aromatic ring around the –NEt2group inN,N,N′,N′-tetraethyl-4,4′-(diazenediyl)dianiline, C20H28N4, (I), may be caused by steric hindrance and the π-electron-donating effects of the amine group. In this structure, one of the amine N atoms demonstrates clearsp2-hybridization and the other is slightly shifted from the plane of the surrounding atoms. The molecule of the second azobenzene, diethyl 4,4′-(diazenediyl)dibenzoate, C18H18N2O4,…
Student Progress in Higher Education: What We Have Learned from Large-Scale Studies
2011
en ligne sur http://www.benthamscience.com/open/toeduj/articles/V004/1TOEDUJ.pdf; International audience; This review examines student progress in higher education based on 28 articles examining 25 large-scale samples of first-year entrants in higher education programs in nine countries. These articles were obtained from a search of published and publicly available research on student departure. Although the results of the studies reviewed are heterogeneous, generalized trends emerge from the synthesis of this body of research on dropout behavior, completion, and time-to-degree. The vast majority of the empirical works reviewed indicate that personal characteristics, family background, prio…