A silicon-cast device that aids in securing rope ends by ensuring a figure-eight knot is tied for use in gym and rock climbing

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (leaf 20).Between the years of 1953 and 2005, there were 253 fatalities from rappel failure/error. Some of these deaths may have been prevented if a stopper knot was tied at the end of the rope. Current climbing habits do not reinforce the tying of a stopper knot. More people are learning to climb in the gym and do not know risk reducing habits when beginning to climb outside, such as tying a stopper knot. The Hedgehog is a silicon device that reinforces the risk reducing habit of tying a stopper knot by a combination of form and color. A specially designed form aids in correct knot tying and the color signals the climber their attention is needed. When the Hedgehog was given to climbers in a climbing gym and had a success rate of 70%. Climbers without the Hedgehog had a success rate of only 8%. Success was defined as having a stopper knot in the rope when the climber began to ascend the route.by Shane M. Treadway.S.B

Atlas 5013 tank corrosion test

The type and cause of corrosion in spot welded joints were determined by X-ray and chemical analysis. Fatigue and static tests showed the degree of degradation of mechanical properties. The corrosion inhibiting effectiveness of WD-40 compound and required renewal period by exposing typical joint specimens were examined

The determination of attitude deviation limits for terminating a non-nominal translunar injection maneuver

Determining attitude deviation limits for translunar injection maneuve

Discharge characteristics of dielectric materials examined in mono-, dual-, and spectral energy electron charging environments

The effects of midenergy electrons on the charge and discharge characteristics of spacecraft dielectric materials and the data base from which basic discharge models can be formulated is expanded. Thin dielectric materials were exposed to low, mid combined low and mid, and spectral energy electron environments. Three important results are presented: (1) it determined electron environments that lead to dielectric discharges at potentials less negative than -5 kV; (2) two types of discharges were identified that dominate the kinds of discharges seen; and (3) it is shown that, for the thin dielectric materials tested, the worst-case discharges observed in the various environments are similar

Our current conceptualisation of peer review must be expanded if we're to realise the greatest innovations

All agree that peer review is an area of scholarly communications that is ripe for innovation. However, it may be that our current conceptualisation of peer review places limits on our progress and ambitions. Jon Treadway highlights four alternative tracks of development, including an increased recognition of the many diverse contributions to the research process, a renewed and widened understanding of what constitutes a “peer”, and a robust evidence base for which techniques and modes of review most consistently benefit authors and the wider scholarly record

Performance Evaluation of Pressure Transducers for Water Impacts

The Orion Multi-Purpose Crew Vehicle is being designed for water landings. In order to benchmark the ability of engineering tools to predict water landing loads, test programs are underway for scale model and full-scale water impacts. These test programs are predicated on the reliable measurement of impact pressure histories. Tests have been performed with a variety of pressure transducers from various manufacturers. Both piezoelectric and piezoresistive devices have been tested. Effects such as thermal shock, pinching of the transducer head, and flushness of the transducer mounting have been studied. Data acquisition issues such as sampling rate and anti-aliasing filtering also have been studied. The response of pressure transducers have been compared side-by-side on an impulse test rig and on a 20-inch diameter hemisphere dropped into a pool of water. The results have identified a range of viable configurations for pressure measurement dependent on the objectives of the test program

Imaging the pathophysiology of major depressive disorder - from localist models to circuit-based analysis

The neuroimaging literature of Major Depressive Disorder (MDD) has grown substantially over the last several decades, facilitating great advances in the identification of specific brain regions, neurotransmitter systems and networks associated with depressive illness. Despite this progress, fundamental questions remain about the pathophysiology and etiology of MDD. More importantly, this body of work has yet to directly influence clinical practice. It has long been a goal for the fields of clinical psychology and psychiatry to have a means of making objective diagnoses of mental disorders. Frustratingly little movement has been achieved on this front, however, and the 'gold-standard’ of diagnostic validity and reliability remains expert consensus. In light of this challenge, the focus of the current review is to provide a critical summary of key findings from different neuroimaging approaches in MDD research, including structural, functional and neurochemical imaging studies. Following this summary, we discuss some of the current conceptual obstacles to better understanding the pathophysiology of depression, and conclude with recommendations for future neuroimaging research