2,367 research outputs found
sj-docx-1-psx-10.1177_00323217221102700 – Supplemental material for Are Political Staffers out of Touch with Grassroots Party Members? Assessing Congruence between Professionals and Volunteers
No full textSupplemental material, sj-docx-1-psx-10.1177_00323217221102700 for Are Political Staffers out of Touch with Grassroots Party Members? Assessing Congruence between Professionals and Volunteers by Pieter Moens in Political Studies</p
Envelope frequency response function calculation of uncertain structures
No full textRequirements for the dynamic properties of a mechanical structure are commonly expressed in terms of eigenfrequencies. Therefore, during the design phase of a mechanical structure much attention is paid to natural frequencies and mode shapes. However, these modal properties tend to vary strongly if small variations are applied on the design model. Therefore, the presence of open design decisions or other uncertain parameters complicates strongly a meaningful dynamic design validation in an early design stage. A fuzzy finite element method for the eigenvalue analysis has been developed to cope with this problem. This method results in fuzzily defined modal properties indicating the degree of uncertainty on the eigenfrequencies and eigenmodes resulting from the uncertain model. However, rather than eigenfrequencies, the specification of responses at frequencies that are critical in the operating conditions of the structure would be a more realistic concept for dynamic design requirements. In order to facilitate the use of such design requirements, a tool is needed to analyze the influence of design decisions on responses at these specific frequencies. Therefore a method for the calculation of fuzzy frequency response functions of uncertain structures is presented. The procedure calculates guaranteed bounds on the envelope on the response function starting from interval bounded uncertainties on the input model. It necessitates the calculation of guaranteed boundaries on the contribution of each individual mode to the total frequency response function.status: Publishe
Analysis of Models of F-Actin Using fluorescence Resonance Energy Transfer Spectroscopy
No full textFluorescence resonance energy transfer spectroscopy (FRET) has been widely used to determine distances ranging from 10 to 100A between amino acids within proteins. However, FRET is not very good at measuring atomic distances because it measures the distance between two probes attached to an amino acid but not the position of the amino acid itself. Therefore, one has to take into consideration the size of the probes used to interpret the FRET data. FRET compensates for that deficit by being particularly sensitive to changes in distance and therefore is suitable to study conformational change in proteins (dos Remedios and Moens 1995a, 1995b).In 1981, Taylor et al. (1981) used FRET to determine the radial coordinate of Cys-374 of actin and study the assembly of actin filament. Subsequently, several authors have used this method to determine the radii of Gln-41 (Kasprzak 1988) the nucleotide binding site (Miki et al. 1986b; Kasprzak 1988) Cys-lO (Miki et al. 1986) and Cys-374(Kasprzak 1988; Moens et al. 1994).When myosin 51 binds to actin filaments, the radial coordinate of Gln-41 increases by 3 A(Kasprzak 1988) and we showed that the radius of Cys-374 increases by approximately 4.5A (Moens et a1. 1997)
Threshold Voltage Instability Mechanisms in p-GaN Gate AlGaN/GaN HEMTs
No full textIn this study, we propose a technique to evaluate the transient threshold voltage behavior of p-GaN capped AlGaN/GaN high-electron-mobility transistors (HEMTs). The threshold voltage is monitored from 10 μs to 100 s during positive gate bias stress. Technology computer-aided design (TCAD) simulations offer in-depth analysis of the different threshold voltage instability mechanisms: (i) electron trapping at the AlGaN/GaN interface, (ii) hole accumulation and trapping at the p-GaN/AlGaN interface and in the AlGaN barrier, respectively, and (iii) hole depletion of the p-GaN layer
Numerical simulation of impact noise generated at the railway insulated joint
No full textThis paper presents a full finite element (FE) model of wheel-track interaction to study the wheel-rail impact noise excited by an insulated joint (IJ). The integration is performed in the time domain with an explicit central difference scheme. The vibratory behaviour of the track and wheel model are respectively validated with hammer test and Axle Box Acceleration (ABA) measurement. By making use of the calculated velocities and pressures on the vibrating surfaces, the boundary element method (BEM) based on Helmholtz equation is adopted to transform the vibrations of the wheel-track into acoustic signals. The decay rate of impact noise at different frequency bands during propagation are analysed. The predictions of total impact noise radiation and the noise contributions of different track components are in good agreement with results reported in the literature, while the effective frequency range is successfully extended from 5 kHz to 10 kHz.Accepted Author ManuscriptRailway Engineerin
A wavelength criterion for the validity of the energy finite element method for plates
No full textThis paper presents a fundamental study of the validity of the Energy Finite Element Method (EFEM) for plates with hysteresis damping. Assumptions and approximations in the derivation of the fundamental energy equations of EFEM limit the validity region of the method. Recent publications present indicators for limits of the validity region, based on experimental deduction and experience. This paper discusses a more fundamental explanation of the validity limits in terms of the assumptions and approximations of EFEM. For plates with hysteresis damping, a limit is found in terms of characteristic dimensions of the plate with respect to the wavelength. Plates with different shapes and boundary conditions are studied. Numerical examples with validation in analytic modal superposition solutions and classical dynamic FEM support the conclusions.status: Publishe
Sophie Mereau : Das Bluthenalter der Empfindung. Herausgegeben und mit Nachwort und Auswahlbibliographie versehen von Herman Moens, 1982
No full textMontandon Alain. Sophie Mereau : Das Bluthenalter der Empfindung. Herausgegeben und mit Nachwort und Auswahlbibliographie versehen von Herman Moens, 1982. In: Dix-huitième Siècle, n°15, 1983. Aliments et cuisine. p. 480
À propos de l'analyse chimique des pigments utilisés dans quelques manuscrits enluminés
No full textDe Reu Martine, Van Hooydonk G., Vandenabeele P., Moens L., Von Bohlen A., Klockenkämper R. À propos de l'analyse chimique des pigments utilisés dans quelques manuscrits enluminés. In: Scriptorium, Tome 53 n°2, 1999. pp. 357-372
Structural Basis for Force Decline in Edl-muscle From Mdx Mice After Eccentric Contraction
No full textEDL-muscles from mdx mice display an irreversible decline in maximal isometric force after eccentric contractions (Moens et al., J MRCM, 14, 446-51). About 50% of the force decline could be explained by membrane-damaged fibres. The unexplained part of the force decline could be caused by damage at the myotendinous junction (MTJ). Ultrathin longitudinal sections were cut at 100 µm intervals from blocks that contained both tendon and muscle. No fibres display separation of basement- and plasma membrane at the MTJ. Our results indicate yet another cause for the unexplained part of the force decline observed after eccentric contractions in EDL muscles from mdx mice
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