Development of reclaimed potable water quality criteria

In order to minimize launch requirements necessary to meet the demands of long-term spaceflight, NASA will reuse water reclaimed from various on-board sources including urine, feces, wash water and humidity condensate. Development of reclamation systems requires the promulgation of water quality standards for potable reuse of the reclaimed water. Existing standards for domestic U.S. potable water consumption were developed, but do not consider the peculiar problems associated with the potable reuse of recycled water. An effort was made to: (1) define a protocol by which comprehensive reclaimed water potability/palatability criteria can be established and updated; and (2) continue the effort to characterize the organic content of reclaimed water in the Regenerative Life Support Evaluation

Pilot dynamic response to sudden flight control system failures and implications for design

Pilot dynamic response to sudden flight control system failure

Who Cares About the Craft Apprentice? A report of a study of the attitudes to further education of 2,000 Scottish craft apprentices

The recent publication by the Scottish Council for Research in Education of ";A Day Off Work?";, concentrates on a description of the attitudes towards further education of some 2000 craft apprentices in Central Scotland. The data was collected during 1968 and 1969 by means of questionnaire, interview and attitude scale and in this article a brief summary will be given mainly in terms of each category of student rather than each source of data. The categories of students involved can be considered in terms of the craft course attended or the mode of attendance. Respondents were drawn from the City and Guilds Craft courses in Catering, Electrical Installation Work, Mechanical Engineering, Fabrication Engineering and Carpentry and Joinery, and over 200 of these followed full-time or block release courses during the investigation

BulB - visualizing bulletin board activity

Visualisation is well known as an effective means of enriching user interaction with complex systems. Recent research with online communities has considered the application of visualisation tool support, with the intention of further improving communication between community members. This paper reviews existing work in this area with specific reference to the application of visualisation to improve user interaction within online forums such as bulletin boards. The paper then outlines work undertaken by the authors to develop a second-generation visualisation tool - 'BulB'

Defect formation in superconducting rings: external fields and finite-size effects

Consistent with the predictions of Kibble and Zurek, scaling behaviour has been seen in the production of fluxoids during temperature quenches of superconducting rings. However, deviations from the canonical behaviour arise because of finite-size effects and stray external fields. Technical developments, including laser heating and the use of long Josephson tunnel junctions, have improved the quality of data that can be obtained. With new experiments in mind we perform large-scale 3D simulations of quenches of small, thin rings of various geometries with fully dynamical electromagnetic fields, at nonzero externally applied magnetic flux. We find that the outcomes are, in practice, indistinguishable from those of much simpler Gaussian analytical approximations in which the rings are treated as one-dimensional systems and the magnetic field fluctuation-free.Comment: 10 pages, 3 figures, presentation at QFS2012, to appear in JLT

Soliton form factors from lattice simulations

The form factor provides a convenient way to describe properties of topological solitons in the full quantum theory, when semiclassical concepts are not applicable. It is demonstrated that the form factor can be calculated numerically using lattice Monte Carlo simulations. The approach is very general and can be applied to essentially any type of soliton. The technique is illustrated by calculating the kink form factor near the critical point in 1+1-dimensional scalar field theory. As expected from universality arguments, the result agrees with the exactly calculable scaling form factor of the two-dimensional Ising model.Comment: 5 pages, 3 figures; v2: discussion extended, references added, version accepted for publication in PR

Fractal Characterizations of MAX Statistical Distribution in Genetic Association Studies

Two non-integer parameters are defined for MAX statistics, which are maxima of $d$ simpler test statistics. The first parameter, $d_{MAX}$, is the fractional number of tests, representing the equivalent numbers of independent tests in MAX. If the $d$ tests are dependent, $d_{MAX} < d$. The second parameter is the fractional degrees of freedom $k$ of the chi-square distribution $\chi^2_k$ that fits the MAX null distribution. These two parameters, $d_{MAX}$ and $k$, can be independently defined, and $k$ can be non-integer even if $d_{MAX}$ is an integer. We illustrate these two parameters using the example of MAX2 and MAX3 statistics in genetic case-control studies. We speculate that $k$ is related to the amount of ambiguity of the model inferred by the test. In the case-control genetic association, tests with low $k$ (e.g. $k=1$) are able to provide definitive information about the disease model, as versus tests with high $k$ (e.g. $k=2$) that are completely uncertain about the disease model. Similar to Heisenberg's uncertain principle, the ability to infer disease model and the ability to detect significant association may not be simultaneously optimized, and $k$ seems to measure the level of their balance