Global ETD Search

1	Psychophysical investigation of the perception of hand-transmitted vibration Morioka, Miyuki January 2001 (has links) No description available. 534
2	Friction and discomfort in the design and use of hand tools : exposure to textures at different loads and velocities with reference to contamination Bobjer, Olle January 2004 (has links) The skin of the palm of the hand has no friction. It is only when in contact with other objects that frictional forces appear. This friction does not, however, conform to the classic laws of friction. The thesis shows that static skin friction is lower than dynamic friction, and that increased velocity increases the coefficient of friction, but increasing load reduces it. Consequently, references to coefficient of friction where palm skin is one of the friction partners require velocity, surface pressure and skin conditions to be specified in addition to contaminants in the friction interface, before reliable conclusions can be drawn. Eleven textured and one non-textured samples all made from the same material were investigated using eighteen male subjects. They were exposed to five contaminants, three skin conditions, three levels ofload and velocities in the range 2-128 mm/so It was concluded that velocity in the friction interface is the most dominant factor contributing to palm friction. Only small, non-significant, differences in friction were found between different types of textures under non-contaminated conditions, but major, and significant differences were observed under contaminated conditions. Coarse textures increased discomfort. For static- and dynamic friction the type of texture, coarse or fine, will affect friction in different ways depending on the skin conditions being "clean" or "contaminated." Experiments show that coarse textures generate less friction than fine under the clean conditions. Under contaminated conditions however coarse textures generate more friction than fine. The highest coefficient offriction 1-1=2.22 (SO=1.12) was recorded under dynamic conditions for a clean hand on a non-textured surface when the surface pressure was low - 6.3 kPa (SO 2.1). The lowest coefficient offriction 1-1=0.05 (SO=0.03) was found under static conditions, with lard present on a non-textured surface when the surface pressure was high - 81.4 kPa (SO=31.0). Two regression models were developed. Regression coefficients are presented for surface topography variables as well as skin condition and contamination, velocity surface pressure and discomfort. Two new surface topography representations explain the generation of friction forces. The uppermost 5% of the volume of texture peaks provided significant information for transfer offriction forces. 621.908
3	Temporal Dynamics of Heat Pain Sensations Hashmi, Javeria Ali 13 August 2010 (has links) The moment-to-moment fluctuations in pain-evoked sensory and emotional qualities, and how the pain experience differs between sexes are not well understood. Therefore, this thesis sought to 1) characterise the temporal profiles of the most prominent noxious heat-evoked sensations, 2) characterise sex differences in these sensations, 3) evaluate the magnitude of sharp pain quality evoked in hairy and glabrous skin, and 4) determine the role of absolute stimulus temperatures on sex differences in pain adaptation and habituation. A broad-based heat pain model was developed for this study that incorporates a temporally-continuous assessment of multiple sensory and affective pain dimensions, including pain, burning, sharp, stinging, cutting, and annoyance evoked by two types (static, dynamic) of repeated prolonged noxious heat stimuli. The salient hypotheses were: 1) Burning sensations have a different temporal profile compared with sharp and other related qualities, 2) The temporal dynamics of heat pain intensity and annoyance differ between males and females, 3) Sex differences in heat pain are associated with specific pain qualities and specific types of skin, and 4) Moderate-high temperatures induce pain adaptation and habituation in females but not in males. The most prominent findings were 1) sharp, stinging and cutting sensations adapted when stimulus intensity was static, but burning sensations were evoked during static and dynamic stimulus phases, 2) pain and annoyance in women were greater than men during the dynamic phases of the first stimulus but less than men during static stimulus phases and on stimulus repetition, 3) the sex difference in pain adaptation occurred with percept-fixed stimulus intensities and with absolute stimulus temperatures, 4) the sex effects associated with dynamic stimuli occurred in hairy but not glabrous skin. These findings give new insights into the relationships between pain intensity, quality and affect and have strong implications for views on sex differences in pain sensitivity. Pain, sex differences in pain pain patterns temporal summation psychophysics tonic pain burning adaptation models habituation temporal heat pain temperature pain modulation glabrous hairy analgesia chronic pain sex women sex differences sharp pain mechanisms a-delta unmyelinated C fibre brain MPQ pain dimensions 0317 0384 0349 0989 0632
4	Temporal Dynamics of Heat Pain Sensations Hashmi, Javeria Ali 13 August 2010 (has links) The moment-to-moment fluctuations in pain-evoked sensory and emotional qualities, and how the pain experience differs between sexes are not well understood. Therefore, this thesis sought to 1) characterise the temporal profiles of the most prominent noxious heat-evoked sensations, 2) characterise sex differences in these sensations, 3) evaluate the magnitude of sharp pain quality evoked in hairy and glabrous skin, and 4) determine the role of absolute stimulus temperatures on sex differences in pain adaptation and habituation. A broad-based heat pain model was developed for this study that incorporates a temporally-continuous assessment of multiple sensory and affective pain dimensions, including pain, burning, sharp, stinging, cutting, and annoyance evoked by two types (static, dynamic) of repeated prolonged noxious heat stimuli. The salient hypotheses were: 1) Burning sensations have a different temporal profile compared with sharp and other related qualities, 2) The temporal dynamics of heat pain intensity and annoyance differ between males and females, 3) Sex differences in heat pain are associated with specific pain qualities and specific types of skin, and 4) Moderate-high temperatures induce pain adaptation and habituation in females but not in males. The most prominent findings were 1) sharp, stinging and cutting sensations adapted when stimulus intensity was static, but burning sensations were evoked during static and dynamic stimulus phases, 2) pain and annoyance in women were greater than men during the dynamic phases of the first stimulus but less than men during static stimulus phases and on stimulus repetition, 3) the sex difference in pain adaptation occurred with percept-fixed stimulus intensities and with absolute stimulus temperatures, 4) the sex effects associated with dynamic stimuli occurred in hairy but not glabrous skin. These findings give new insights into the relationships between pain intensity, quality and affect and have strong implications for views on sex differences in pain sensitivity. Pain, sex differences in pain pain patterns temporal summation psychophysics tonic pain burning adaptation models habituation temporal heat pain temperature pain modulation glabrous hairy analgesia chronic pain sex women sex differences sharp pain mechanisms a-delta unmyelinated C fibre brain MPQ pain dimensions 0317 0384 0349 0989 0632

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