Effects of Pack Weight on Endurance of Long-distance Hikers

Hikers attempting long-distance trails, like the Appalachian Trail, load their backpacks down with gear that may exceed ideal limits on pack weight. Hikers pack clothing to deal with changing weather conditions, sleeping bags, tents, tarps, cooking gear, food, water and other accessories to compensate for the lack of comfort in the remote wilderness. These heavy weights may affect hikers\u27 ability to walk in comfort and result in physical injuries such as ankle sprains, knee pain, muscular fatigue, and soft tissue damage. Heavy pack weights can cause injuries and possibly prevent hikers from completing long distance hikes. This study evaluated pack weight to understand the limits of long-term load carriage. Participants were Appalachian Trail hikers who attempted to complete the entire trail in the 2012 season. Hikers were asked to complete a series of online surveys throughout the duration of their hike to assess pack weight, body weight, injuries/illnesses sustained, miles hiked, and reasons for quitting a long-distance hike. Through logistic regression analysis an equation for the prediction of completing the trail was developed. The evaluations of pack weight, load percentage of total body weight, average miles hiked per day, Body Mass Index (BMI), experience, and gender revealed how they affect the prediction process. The independent variables used for prediction show interdependency throughout the analysis with moderate relationships that would be required to successfully predict a hiker to complete the trail. In addition, there was supporting data that reflected higher instances of pack related injury reports to hikers who carried heavier pack weights. This study illustrates trends in pack weight and load percentages that may provide useful in suggesting weight limits to increase the success rates of hikers and reduce injuries. The hypothesis that hikers were negatively affected in the number of miles hiked as pack weight increases was supported in the study

EVALUATION OF TITANIUM ULTRALIGHT MANUAL WHEELCHAIRS USING ANSI/RESNA STANDARDS

A series of commercially available titanium ultralight wheelchairs were tested using ANSI/RESNA testing procedures, and their durability was compared with previously tested aluminum ultralight wheelchairs and light-weight wheelchairs. Three of each of the following titanium wheelchairs were tested: Invacare-TopEnd, Invacare-A4, Quickie-Ti, and TiLite-ZRA. The Quickie-Ti wheelchairs had the most forward and rearward center of gravity adjustability. All of the titanium wheelchairs passed the forward braking effectiveness test, but two chairs of each model tipped backward before the platform inclining to 7 degree in the rearward braking effectiveness test. All titanium wheelchairs passed the impact strength tests, but two failed in the static strength tests: two Invacare-TopEnd wheelchairs and one Invacare-A4 wheelchair failed due to deformation of the armrest mounting plates, and the handgrips of the TiLite-ZRA wheelchairs slid off the push handles. Two Invacare-A4 and one Invacare-TopEnd successfully completed the double drum and curb drop tests, but the remaining 9 wheelchairs failed prematurely. No significant differences were found in the number of the equivalent cycles or the value among the four models. The titanium ultralight wheelchairs had less equivalent cycles and value than the aluminum ultralight wheelchairs that were tested in a previous study. The failure modes in the static strength tests and the fatigue tests were consistent within the model, and revealed important design issues for each model. Our results suggest that manufacturers need to perform more careful analyses before commercializing new products

Bear Minimum: Ultralight Composite Bear Canister

The ultralight backpacking community needs a strong, easy to use, safe bear canister that is lighter than current market products for trekking in the backcountry. A full design of the lid for the bear canister is to be completed. This includes the locking mechanism to ensure it is bear proof, the interface between the lid and the canister, and the structure of the lid so it passes the strength and weight specifications. The lid, along with the already designed canister body, is to be manufactured with formal documentation. The lid will initially be tested separately and then with the canister body as an assembly. All tests will be to either verify or reject one or more of the design specifications listed later in this document. The overarching goal of the project is to find a balance of two project requirements: making a rigid lid that is, when combined with the canister body, less than 1.3 lbf and still meeting the Interagency Grizzly Bear Committee (IGBC) certification strength requirements

DESIGN AND DEVELOPMENT OF A PEDIATRIC WHEELCHAIR WITH TILT-IN-SPACE SEATING

The Pediatric Adjustable Lightweight Modular (PALM) wheelchair project consisted of three design iterations, full-scale working prototypes, durability testing and user evaluation, and technology transfer activities. User input was crucial to developing design requirements. A handful of concepts developed for this design are novel in the wheelchair market and potentially beneficial to pediatric wheelchair users and their caregivers. Some of the concepts could be applied to other wheelchair designs in the future, including adult tilt-in-space wheelchairs and seating for both adults and children. The PALM's primary construction consists of modular plastic injection molded components and straight tubes. This feature allows it to be easily customized on site by a therapist who can swap components and make adjustments. The modular design also allows it to be packed more compactly thereby decreasing manufacturing and shipping costs. Second, the tilt-in-space mechanism utilizes a unique four-bar linkage design that decreases the need for small moving parts such as rollers and spring loaded mechanisms used in other tilt-in-space center-of-gravity chairs. Third, the PALM's modular design allows for greater flexibility in the configuration of the wheelchair and adaptation to different-sized bodies. Fourth, the PALM is highly adjustable and selectable: The seat depth, seat width, back rest height, back rest angle, leg rest angle, footrest angle, seat-to-floor height, and axle position are all adjustable. Finally, the PALM converts from an attendant-style wheelchair to a self-propelled wheelchair. These features create a variety of characteristics that clearly distinguish the PALM from other currently available pediatric wheelchairs

Design of a Power-Assist Hemiplegic Wheelchair

Current one-handed manual wheelchairs are difficult to propel because one arm can only provide half the power that is ascertained in a two-handed manual wheelchair. A power-assisted hemiplegic (one-sided paralysis) wheelchair was developed that can effectively be propelled with one arm while remaining maneuverable, lightweight, and foldable. An existing manual wheelchair was minimally modified and fitted with powerassisted components that could alternatively be attached to a wide range of manual wheelchairs. The design implements a motor and gear train to power the wheel on the users affected side, encoders on both rear wheels to track wheel position, and a heel interface on the footrest to control steering. A controls program was developed that analyzes wheel position and steering to respond to the motion of the hand-driven wheel. Extensive testing was performed to ensure design integrity. Testing results showed that the prototype successfully met and exceeded predetermined design specifications based on industry standard testing procedures. The design has the potential to deliver increased freedom to a considerable consumer base

CHAMP: Tree Climbing Robot

Observing wildlife, monitoring forest health, conducting research, and detecting invasive species and infections are just a few of the crucial tasks that currently require humans to climb trees. Putting people into trees is an expensive and potentially dangerous task. The CHAMP (Compliant Hook Arboreal Mobility Platform) is a tree climbing robot that carries and controls job-specific payloads to improve the safety and efficiency of many arboreal tasks

Aeronautical Engineering: A continuing bibliography with indexes, supplement 153, October 1982

This bibliography lists 535 reports, articles and other documents introduced into the NASA Scientific and Technical Information System in September 1982

UAV or Drones for Remote Sensing Applications in GPS/GNSS Enabled and GPS/GNSS Denied Environments

The design of novel UAV systems and the use of UAV platforms integrated with robotic sensing and imaging techniques, as well as the development of processing workflows and the capacity of ultra-high temporal and spatial resolution data, have enabled a rapid uptake of UAVs and drones across several industries and application domains.This book provides a forum for high-quality peer-reviewed papers that broaden awareness and understanding of single- and multiple-UAV developments for remote sensing applications, and associated developments in sensor technology, data processing and communications, and UAV system design and sensing capabilities in GPS-enabled and, more broadly, Global Navigation Satellite System (GNSS)-enabled and GPS/GNSS-denied environments.Contributions include:UAV-based photogrammetry, laser scanning, multispectral imaging, hyperspectral imaging, and thermal imaging;UAV sensor applications; spatial ecology; pest detection; reef; forestry; volcanology; precision agriculture wildlife species tracking; search and rescue; target tracking; atmosphere monitoring; chemical, biological, and natural disaster phenomena; fire prevention, flood prevention; volcanic monitoring; pollution monitoring; microclimates; and land use;Wildlife and target detection and recognition from UAV imagery using deep learning and machine learning techniques;UAV-based change detection