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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Weight load carry : a review of the efficiency and effectiveness of the army backpack /

Lehmann, Frederick Denis. January 1998 (has links)
Thesis (M.Sc. (Hons.)) -- University of Western Sydney, Hawkesbury, 1998. / Bibliography : leaves 117-130.
62

The effect of load and technique on biomechanical and psychophysical responses to level dynamic pushing and pulling /

Bennett, Anthena Iona. January 2008 (has links)
Thesis (M.Sc. (Human Kinetics & Ergonomics)) - Rhodes University, 2009.
63

Gebräuche und Leistungsfähigkeit des Menschen im Tragen von Lasten Eine biogeographische Untersuchung.

Kenntner, Georg. January 1973 (has links)
Habilitationsschrift--Universität des Saarlandes, Saarbrücken. / Summary in English. Bibliography: p. 147-152.
64

Designing a passenger lift and transfer device using 3D modeling and kinematic simulation techniques /

Koshti, Sushim. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 97-98). Also available on the World Wide Web.
65

Biomechanics of dependent transfers on an aircraft /

Higginson, Brian Keith. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2008. / Printout. Includes bibliographical references. Also available on the World Wide Web.
66

Laboratory investigation of a load carriage task observed in forestry

Furney, Sheena Elizabeth January 2007 (has links)
The objective of the present study was to investigate and compare the human responses to two load carriage tasks performed with three different load masses and on three different gradients. The task of carrying hydrogel in one hand was observed in a silviculture industry and crude physiological and perceptual responses were measured. This task was simulated in a laboratory setting together with a suggested intervention of backpack carriage. Eighteen conditions were established which consisted of the two modes of carriage and a combination of three load masses (9kg, 12kg and 15kg) and three gradients (5%, 10% and 15%). Twenty eight Rhodes University female students comprised the sample and the experimental procedures were conducted on a Quinton treadmill. Each participant was required to complete nine of the eighteen conditions which were each four minutes in duration. Postural changes were assessed using lateral and posterior digital images taken at the second and fourth minute and compression and shearing forces were estimated with the ErgolmagerTM Physiological responses (heart rate, ventilation and metabolic responses) were measured continuously with the Quark b² and perceptual responses ('central' and 'local' RPE) were measured every minute during the experimentation and body discomfort was rated at the completion of each condition. Overall responses revealed that hand carriage (146 bt.min⁻¹ , 25.09 mIO₂. kg-l.min⁻¹) was generally found to be more physiologically stressful than backpack carriage (130 bt.min⁻¹, 22.15 mIO₂.kg⁻¹ .min⁻¹) independent of load mass and gradient. Physiological responses were higher (113 bt.min-1 to 174 bt.min⁻¹ ) in responses to increasing gradient as opposed to increasing load mass (104 bt.min-1 to 153 bt.min⁻¹ ) for both backpack and hand carriage. Categorisation using the guidelines of Sanders and McCormick (1993) allowed for classification of conditions, with respect to physiological responses, into 'moderate', 'heavy' and 'very heavy' stress. For almost all of the physiological responses the majority of conditions which were classified as 'moderate' were backpack carriage conditions and the conditions classified as 'very heavy' were mostly hand carriage conditions. In terms of postural responses hand carriage resulted in more strain and greater compression and shearing forces on the spine. In terms of the compression forces increasing gradient had a greater affect on backpack carriage (681 N to 935 N) compared to hand carriage (570N to 793N). In contrast, increasing load mass had a larger affect on hand carriage postures and compression forces (751 N to 935N) in comparison to backpack carriage (723N to 780N). Shearing forces were found to be worse in hand carriage conditions overall. Although participants generally underrated perceived exertion in relation to cardiorespiratory responses, these perceptions revealed that backpack carriage, with a mean 'central' RPE of 12 compared to 11 for hand carriage, was somewhat preferred to hand carriage and that increasing gradient was perceived to be marginally more straining than increasing load mass.
67

Three dimensional kinetic analysis of asymmetrical lifting

Li, Jian-Chuan January 1996 (has links)
Manual lifting is dynamic in nature and involves asymmetrical loading of the human body. This study investigated kinematic and kinetic characteristics of asymmetrical lifting in three dimensions, and then constructed a 3-D biomechanical force model of the lower back which is capable of quantifying torsional stress on the human spine. Eleven healthy adult male manual workers were recruited as subjects and lifted a 1 Okg load placed at the sagittal plane (0°) and at 30°, 60° and 90° lateral planes to the right, from 150mm and 500mm initial lift heights, respectively, to an 800mm high bench in the sagittal plane. Subjects' spinal motions and the trajectorial movements of the load in three-dimensional space were monitored simultaneously by a Lumbar Motion Monitor and a V-scope Motion Analyzer. Generally, the spinal motion factors increased as a function of increasing task asymmetry and differed (p < 0.05) between the lower (150mm) and higher (500mm) levels in the sagittal plane. In all asymmetrical conditions the motion factors showed a dramatic increase at the 500mm level compared to the increase at the 150mm level. The rates of increase in the horizontal and frontal planes were greater than those in the sagittal plane. Task asymmetry had a significant effect on the spinal kinematic parameters in the frontal plane at the two lift heights, and only at the high level (500mm) in the horizontal plane, with exception of average acceleration . Initial lift height exerted a significant effect on peak velocity and acceleration in both frontal and horizontal planes and on range of motion in the horizontal plane. Kinetic characteristics of the object being lifted in three-dimensions increased with an increase in task asymmetry. The increase was more dramatic in the lateral direction in the horizontal plane. However, motion factors in the vertical direction dominated the full range of the lift, irrespective of task asymmetry and lift height. The kinetic measures differed (p < 0.05) between the lower ( 1 50mm) and the higher (500mm) levels in the vertical direction except for average force. Task asymmetry had a significant effect on dynamic measures in the anterior-posterior direction. Both task asymmetry and lift height had a significant effect on dynamic motion factors in the lateral direction. From insights gained in the empirical study a three-dimensional biomechanical force model of the lower back was constructed based on a mechanism of muscle force re-orientation in the lumbar region. Acknowledging that the lower back is designed to be able to rotate around its longitudinal axis, the proposed model accounts for compression and shear forces and a torsional moment. The model has similar predictability to Schultz and Andersson's (1981) model when the human trunk exerts only a flexion-extension moment in the sagittal plane, but additionally predicts dramatic increases in shear forces, oblique muscle forces and torsional moment under asymmetrical lifting conditions which the Schultz-Andersson model does not. The increase rates in these forces and moment are not linearly related over task asymmetric angle.
68

The effect of load and technique on biomechanical and perceptual responses during dynamic pushing and pulling

Desai, Sheena Dhiksha January 2009 (has links)
Changes in the industrial job profile, from lifting and lowering to repetitive dynamic pushing and pulling have been facilitated through the use of manual vehicles, aimed at minimising the workload. Yet, the demands of pushing and pulling have not been well documented. Using measures of the horizontal component of the hand forces, spinal kinematics, muscle activity at various sites on the upper body and body discomfort ratings, this study aimed at quantifying the biomechanical and perceptual demands of various dynamic push/pull techniques. 36 healthy male participants performed two-handed forward pushing, two-handed backward pulling and one-handed forward pulling, employing an industrial pallet jack supporting two loads of 250kg or 500kg. While no single technique was definitively identified as preferable regarding hand forces, pushing at 500kg elicited higher initial and sustained forces (p<0.05) than one- and two-handed pulling respectively. Increments in load mass from 250kg to 500kg resulted in significant differences in the initial, sustained and ending forces. With regard to spinal kinematics in the sagittal plane, two-handed pulling elicited the highest trunk flexion, and may therefore expose individuals to prolonged forward bending. Generally this technique was found to evoke the highest sagittal responses. Spinal kinematic measures in the lateral and transverse planes suggested that one-handed pulling was accompanied by the highest measures, and hence the greatest risk of developing lower back disorders related to this plane. Although various combinations of muscles were active during each technique, one-handed pulling and pushing, most often induced the highest muscle activation levels and two-handed pulling, the lowest. While erector spinae evidenced no significant differences between techniques at each load or between loads for the same technique, activation levels were high under all conditions. Perceptual ratings of body discomfort revealed that not only is the upper body susceptible to injuries during pushing and pulling, but also that the lower extremities may have a considerable role to play in these tasks, with the calves being a particular area of concern. Findings concluded that symmetrical pushing and pulling tasks are preferable.
69

Carrying capacity assessment of diving sites in Hong Kong and Malaysia

Zhang, Liye 20 June 2016 (has links)
This study aims to understand tourism carrying capacities of diving sites in Hong Kong and Malaysia. Specifically, ecological, psychological and social carrying capacities were assessed. Methodology involved photo quadrat transect survey, questionnaire survey and visual experiment survey. Over a period of two calendar years (2013 and 2014), 13, 12 and 9 photo quadrat transect surveys were conducted in Sharp Island, Tsim Chau and Mabul Island (Ray Point and Eel Garden) respectively to provide data for ecological carrying capacity assessment. In addition, 455 and 342 questionnaires were collected in Hong Kong and Mabul Island respectively to assess divers' satisfaction with diving attributes of the respective dive sites. Regarding social carrying capacity assessment, 247 and 158 visual experiment questionnaires were collected to assess crowding as perceived by divers in the two sites.;The ecological carrying capacity of Sharp Island lies between 172 and (less than) 825 divers every quarter in the absence of better solutions. At Tsim Chau, diving activity is not the most important factor in influencing the coverage of sea anemone. In addition, the use of additional (subjective) data was necessary to define the ecological carrying capacity of Tsim Chau and possibly Sharp Island. In Mabul Island, the results show that the ecological carrying capacity is about 16800-17200 divers per year at Ray Point and about 15600-16800 divers per year at Eel Garden. Based on the findings, it is likely that the usage of the diving sites on Sharp Island, Ray Point and Eel Garden have already exceeded the social carrying capacity. Regarding the psychological carrying capacity, this study found that the most important factor that influences divers' willingness to return to Hong Kong diving sites is "the quality of corals". In Mabul Island, the most important factor is "the value for money of Mabul diving". However, no studied diving sites have exceeded their psychological carrying capacities. Regarding the social carrying capacity, on both Hong Kong and Mabul Island diving sites, the "number of divers" was found to be the most influential factor for divers' perceived crowding. In Hong Kong, divers' begin to feel unacceptably crowded if 78̃ divers are visible to them at one time whereas in Mabul Island, divers would start to feel unacceptably crowded if 8 to 9 divers were visible to them at one time. Based on this, it is likely that the usage of both Hong Kong and Mabul Island diving sites have already exceeded the social carrying capacity.;With the increasing popularity of diving in recent years, divers and diving trips operators around the world need to be aware of divers' impact on coral reef, divers' satisfaction and underwater crowding problem. Finally, a series of management and policy measures to minimise the impact of diving activity on coral, improve divers' satisfaction and mitigate divers' crowding perception in underwater environment are proposed for sustainable use of diving sites in Hong Kong and Mabul Island.
70

Towards Sustainable Use of Groundwater Resources: Aquifer 23, La Mancha-Spain.

Doncel Fuentes, Pablo January 2015 (has links)
La Mancha Plain lies in the core of Spain and partially stretches over the Guadiana River Upper Basin (UGB), is one of the most arid regions of the Iberian Peninsula, indeed “La Mancha” in Arabic means “the dry”, and also houses a vast Aquifer that has supported the related numerous marshlands and hydro-ecosystems in harmony with the human development till the 1970s, when the “Agrarian Green Revolution” commenced. Land reclamation over River and lagoon beds joined to the irrigation implementation of more than 150.000 Ha have badly bled the water resources to the maximum usable limit, lowering the phreatic table down to 60 meters, provoking a serious ecological damage for the 25.000 Ha of wetlands highly dependent on shallow phreatic levels. Recently, Nature granted the wettest period ever registered in the area (2009-2012) which caused an incredible natural replenishment of that Aquifer deficit. However, even though several costly plans and policies have been undertaken, it is still pending to effectively control the extractions, to manage the Aquifer within a portion allowing a certain continuous upwelling to enliven the Guadiana River real spring, and also, to adjust the essential agriculture sector to the environmental conditions and carrying capacity of the system.

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