James Croll - Academia.edu (original) (raw)
Papers by James Croll
Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 2021
At a time when nobody has yet landed on the Antarctic continent (1879), this presentation and acc... more At a time when nobody has yet landed on the Antarctic continent (1879), this presentation and accompanying paper predicts the morphology, dynamics and thermal regime of the Antarctic ice sheet. Mathematical modelling of the ice sheet is based on the assumptions that the thickness of tabular icebergs reflects the average thickness of the ice at the margin and that the surface gradients are comparable to those of reconstructed former ice sheets in the Northern Hemisphere. The modelling shows that (a) ice is thickest near the centre at the South Pole and thins towards the margin; (b) the thickness at the pole is independent of the amount of snowfall at that place; and (c) the mean velocity at the margin, assuming a mean annual snowfall of two inches per year, is 400–500 feet per year. The thermal regime of the ice sheet is influenced by three heat sources – namely, the bed, the internal friction of ice flow and the atmosphere. The latter is the most significant and, since ice has a dow...
Clinical Physiology and Functional Imaging, 2008
design education for engineers, 1996
Proceedings of the Human Factors and Ergonomics Society Annual Meeting
J Bus Psychol, 1988
This study examined correlates of satisfaction with a continuing education course, among a group ... more This study examined correlates of satisfaction with a continuing education course, among a group of 2,980 bankers. Bankers were likely to be satisfied with their courses if (a) the classwork was applicable to their present job; (b) they were interested in the previous courses they had taken, (c) they expected a good grade from the courses, and (d) they had a high self-concept. Implications of these results for continuing education are presented.
Aviation, space, and environmental medicine, 2007
This study examined metabolic and hemodynamic responses during night vision goggle (NVG) induced ... more This study examined metabolic and hemodynamic responses during night vision goggle (NVG) induced neck strain among military helicopter pilots. We hypothesized that near infrared spectroscopy (NIRS) would be capable of identifying metabolic differences in the trapezius muscles of pilots between simulated flights with and without NVG. There were 33 pilots who were monitored on consecutive days during Day and NVG flight simulator missions. NIRS probes were attached bilaterally to the trapezius muscles at the C7 level to record total oxygenation index (TOI, %), total hemoglobin (tHb), oxyhemoglobin (HbO2), and deoxyhemoglobin (HHb). Significant differences in tHb were found between Day (0.51+/-2.31 micromol x cm (-1)) and NVG (4.14 +/- 2.74 micromol x cm(-1)) missions, and for HbO2 (Dayend 2.63+/-1.64 micromol x cm(-1); NVGend 5.77+/-1.98 micromol x cm(-1)). Significant left and right side differences between Day and NVG were found for tHb (NVGleit -1.83+/-2.55; NVGright 10.45+/-2.86 mi...
Military medicine, 2007
Increased helmet-mounted mass and specific neck postures have been found to be a cause of increas... more Increased helmet-mounted mass and specific neck postures have been found to be a cause of increased muscular activity and stress. However, pilots who use night vision goggles (NVG) frequently use counterweight (CW) equipment such as a lead mass that is attached to the back of the flight helmet to provide balance to counter the weight of the NVG equipment mounted to the front of the flight helmet. It is proposed that this alleviates this stress. However, no study has yet investigated the physiological effects of CW during an extended period of time during which the pilots performed normal operational tasks. Thirty-one Canadian Forces pilots were monitored on consecutive days during a day and a NVG mission in a CH-146 flight simulator. Near infrared spectroscopy probes were attached bilaterally to the trapezius muscles and hemodynamics, i.e., total oxygenation index, total hemoglobin, oxyhemoglobin, and deoxyhemoglobin, were monitored for the duration of the mission. Pilots either wor...
The prevalence of neck and low back musculoskeletal injuries in transit operators has been shown ... more The prevalence of neck and low back musculoskeletal injuries in transit operators has been shown to be high; with work absences exceeding double the National average. There is a lack of biomechanical data generated from field researches to inform on musculoskeletal risk associated with transportation and driving occupations. Instead there has been a reliance on simulated driving and questionnaire-based research. This study was designed to examine the musculoskeletal and biomechanical stresses experienced by urban bus drivers. The main objective was to obtain a baseline understanding of sitting posture, muscle activiation and subjective ratings of stress during regular driving tasks. Fifteen urban city bus drivers were recruited for this study. Bus drivers drove the same 65-minute bus route once, at the same time of day, in the same preselected bus. Wireless surface electromyography monitored muscular activity of the drivers' neck, upper trapezius, and erector spinae and video analysis and seat pressure mapping was used to monitor changes in driving posture. A health and lifestyle questionnaire was administered to record specific neck and back pain experienced by drivers as well as to provide lifestyle habits. Drivers were found to exhibit non-neutral postures for less than 30% of the time while conducting routine tasks of turning and stopping for passenger loading and unloading. The neck posture was the greatest concern in terms of non-neutral posture and this was supported by the higher muscle activation to the neck musculature. There was significant posture adjustment made during the one-hour driving period with the adjustments increasing with driving time. Activities associated with bus driving appear to require the use of non-neutral postures an increase in muscle activation. Significant postural adjustments were needed over the one-hour observation period suggesting that the musculoskeletal demands may increase over a regular 12-hour shift.
Medicine & Science in Sports & Exercise, 2005
Wolters Kluwer Health may email you for journal alerts and information, but is committed to maint... more Wolters Kluwer Health may email you for journal alerts and information, but is committed to maintaining your privacy and will not share your personal information without your express consent. For more information, please refer to our Privacy Policy. ... Skip Navigation Links Home > May ...
Medicine & Science in Sports & Exercise, 2006
Medicine & Science in Sports & Exercise, 2005
Journal of Obstetric, Gynecologic, & Neonatal Nursing, 2008
Journal of Employment Counseling, 1983
ABSTRACT
Journal of Business and Psychology, 1988
This study examined correlates of satisfaction with a continuing education course, among a group ... more This study examined correlates of satisfaction with a continuing education course, among a group of 2,980 bankers. Bankers were likely to be satisfied with their courses if (a) the classwork was applicable to their present job; (b) they were interested in the previous courses they had taken, (c) they expected a good grade from the courses, and (d) they had a high self-concept. Implications of these results for continuing education are presented.
International Journal of Industrial Ergonomics, 2011
Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 2021
At a time when nobody has yet landed on the Antarctic continent (1879), this presentation and acc... more At a time when nobody has yet landed on the Antarctic continent (1879), this presentation and accompanying paper predicts the morphology, dynamics and thermal regime of the Antarctic ice sheet. Mathematical modelling of the ice sheet is based on the assumptions that the thickness of tabular icebergs reflects the average thickness of the ice at the margin and that the surface gradients are comparable to those of reconstructed former ice sheets in the Northern Hemisphere. The modelling shows that (a) ice is thickest near the centre at the South Pole and thins towards the margin; (b) the thickness at the pole is independent of the amount of snowfall at that place; and (c) the mean velocity at the margin, assuming a mean annual snowfall of two inches per year, is 400–500 feet per year. The thermal regime of the ice sheet is influenced by three heat sources – namely, the bed, the internal friction of ice flow and the atmosphere. The latter is the most significant and, since ice has a dow...
Clinical Physiology and Functional Imaging, 2008
design education for engineers, 1996
Proceedings of the Human Factors and Ergonomics Society Annual Meeting
J Bus Psychol, 1988
This study examined correlates of satisfaction with a continuing education course, among a group ... more This study examined correlates of satisfaction with a continuing education course, among a group of 2,980 bankers. Bankers were likely to be satisfied with their courses if (a) the classwork was applicable to their present job; (b) they were interested in the previous courses they had taken, (c) they expected a good grade from the courses, and (d) they had a high self-concept. Implications of these results for continuing education are presented.
Aviation, space, and environmental medicine, 2007
This study examined metabolic and hemodynamic responses during night vision goggle (NVG) induced ... more This study examined metabolic and hemodynamic responses during night vision goggle (NVG) induced neck strain among military helicopter pilots. We hypothesized that near infrared spectroscopy (NIRS) would be capable of identifying metabolic differences in the trapezius muscles of pilots between simulated flights with and without NVG. There were 33 pilots who were monitored on consecutive days during Day and NVG flight simulator missions. NIRS probes were attached bilaterally to the trapezius muscles at the C7 level to record total oxygenation index (TOI, %), total hemoglobin (tHb), oxyhemoglobin (HbO2), and deoxyhemoglobin (HHb). Significant differences in tHb were found between Day (0.51+/-2.31 micromol x cm (-1)) and NVG (4.14 +/- 2.74 micromol x cm(-1)) missions, and for HbO2 (Dayend 2.63+/-1.64 micromol x cm(-1); NVGend 5.77+/-1.98 micromol x cm(-1)). Significant left and right side differences between Day and NVG were found for tHb (NVGleit -1.83+/-2.55; NVGright 10.45+/-2.86 mi...
Military medicine, 2007
Increased helmet-mounted mass and specific neck postures have been found to be a cause of increas... more Increased helmet-mounted mass and specific neck postures have been found to be a cause of increased muscular activity and stress. However, pilots who use night vision goggles (NVG) frequently use counterweight (CW) equipment such as a lead mass that is attached to the back of the flight helmet to provide balance to counter the weight of the NVG equipment mounted to the front of the flight helmet. It is proposed that this alleviates this stress. However, no study has yet investigated the physiological effects of CW during an extended period of time during which the pilots performed normal operational tasks. Thirty-one Canadian Forces pilots were monitored on consecutive days during a day and a NVG mission in a CH-146 flight simulator. Near infrared spectroscopy probes were attached bilaterally to the trapezius muscles and hemodynamics, i.e., total oxygenation index, total hemoglobin, oxyhemoglobin, and deoxyhemoglobin, were monitored for the duration of the mission. Pilots either wor...
The prevalence of neck and low back musculoskeletal injuries in transit operators has been shown ... more The prevalence of neck and low back musculoskeletal injuries in transit operators has been shown to be high; with work absences exceeding double the National average. There is a lack of biomechanical data generated from field researches to inform on musculoskeletal risk associated with transportation and driving occupations. Instead there has been a reliance on simulated driving and questionnaire-based research. This study was designed to examine the musculoskeletal and biomechanical stresses experienced by urban bus drivers. The main objective was to obtain a baseline understanding of sitting posture, muscle activiation and subjective ratings of stress during regular driving tasks. Fifteen urban city bus drivers were recruited for this study. Bus drivers drove the same 65-minute bus route once, at the same time of day, in the same preselected bus. Wireless surface electromyography monitored muscular activity of the drivers' neck, upper trapezius, and erector spinae and video analysis and seat pressure mapping was used to monitor changes in driving posture. A health and lifestyle questionnaire was administered to record specific neck and back pain experienced by drivers as well as to provide lifestyle habits. Drivers were found to exhibit non-neutral postures for less than 30% of the time while conducting routine tasks of turning and stopping for passenger loading and unloading. The neck posture was the greatest concern in terms of non-neutral posture and this was supported by the higher muscle activation to the neck musculature. There was significant posture adjustment made during the one-hour driving period with the adjustments increasing with driving time. Activities associated with bus driving appear to require the use of non-neutral postures an increase in muscle activation. Significant postural adjustments were needed over the one-hour observation period suggesting that the musculoskeletal demands may increase over a regular 12-hour shift.
Medicine & Science in Sports & Exercise, 2005
Wolters Kluwer Health may email you for journal alerts and information, but is committed to maint... more Wolters Kluwer Health may email you for journal alerts and information, but is committed to maintaining your privacy and will not share your personal information without your express consent. For more information, please refer to our Privacy Policy. ... Skip Navigation Links Home > May ...
Medicine & Science in Sports & Exercise, 2006
Medicine & Science in Sports & Exercise, 2005
Journal of Obstetric, Gynecologic, & Neonatal Nursing, 2008
Journal of Employment Counseling, 1983
ABSTRACT
Journal of Business and Psychology, 1988
This study examined correlates of satisfaction with a continuing education course, among a group ... more This study examined correlates of satisfaction with a continuing education course, among a group of 2,980 bankers. Bankers were likely to be satisfied with their courses if (a) the classwork was applicable to their present job; (b) they were interested in the previous courses they had taken, (c) they expected a good grade from the courses, and (d) they had a high self-concept. Implications of these results for continuing education are presented.
International Journal of Industrial Ergonomics, 2011