Search results for "Force dynamics"
showing 5 items of 5 documents
Dynamic force spectroscopy: analysis of reversible bond-breaking dynamics
2008
The problem of diffusive bond-dissociation in a double well potential under application of an external force is scrutinized. We compute the probability distribution of rupture forces and present a detailed discussion of the influence of finite rebinding probabilities on the dynamic force spectrum. In particular, we focus on barrier crossing upon extension, i.e. under linearly increased load, and upon relaxation starting from completely separated bonds. For large loading rates the rupture force and the rejoining force depend on the loading rate in the expected manner determined by the shape of the potential. For small loading rates the mean forces obtained from pull and relax modes approach …
Recognition of Chip Forms by Means of Dynamic Force Spectrum Analysis
1993
In this study the ability to identify chip forms occurrs in the turning of austenitic stainless steel using dynamic force spectrum analysis has been tested. For this purpose the frequency spectra obtained from various metal cutting tests were recorded along with the static cutting forces. A dual channel analysis, based on the Fast Fourier Transform (FFT), was adopted to help identify the continuous/discontinuous (favourable/unfavourable) chip forming boundary. The results showed an acceptable correlation between the types of the frequency spectra and the types of chip forms. Finally, an original classification of the spectra obtained during turning of AISI 304 (DIN 1.4301) stainless steel i…
The effects of intensity, frequency, static load, and shore hardness on different parameters in vibration sensitivity measurements.
1987
The effects of shore hardness, static load, frequency, and intensity of vibration on the amplitude and dynamic force effects of vibration were studied in conditions corresponding to those occurring in vibrotactile sensitivity measurements. The measurements were performed on three silicon plates of known shore hardness. The results indicated that the effect of differences in elasticity on the vibration amplitudes was evident at lower frequencies up to about 200 Hz whereas at higher frequencies the amplitudes remained at the same level, regardless of elasticity. On dynamic force the effect of elasticity was observed at all frequencies studied (50-500 Hz). The static load of the contractor had…
Achieving high effectiveQ-factors in ultra-high vacuum dynamic force microscopy
2010
The effective Q-factor of the cantilever is one of the most important figures-of-merit for a non-contact atomic force microscope (NC-AFM) operated in ultra-high vacuum (UHV). We provide a comprehensive discussion of all effects influencing the Q-factor and compare measured Q-factors to results from simulations based on the dimensions of the cantilevers. We introduce a methodology to investigate in detail how the effective Q-factor depends on the fixation technique of the cantilever. Fixation loss is identified as a most important contribution in addition to the hitherto discussed effects and we describe a strategy for avoiding fixation loss and obtaining high effective Q-factors in the forc…
Between Composition and Emergentness: A Cognitive Semantics Re-Reading of the Way-Construction
2016
This study re-analyzes the English way-construction by having recourse to diverse concepts and tools of Talmy’s cognitive semantics. Drawing on his theory of recombinance and its relevance for conceptualizing the construction, the article implements Talmy’s theory of event integration, categorizes the way-construction as an instantiation of the open path event frame, considers link-ups of the schematic systems of force dynamics and attention as they become instantiated in the construction, and probes into its motion-aspect patterning, grounded in a conformation of space and time and resulting in a strategy that is called de-conflation. Further, it will recruit Talmy’s types of semantic conf…