11,595 research outputs found
Teleprinter uses thermal printing technique
Alphameric/facsimile printer receives serial digital data in the form of a specified number of bits per group and prints it on thermally sensitive paper. A solid state shift-register memorizes the incoming serial digital data
Scaling Properties of Paths on Graphs
Let be a directed graph on finitely many vertices and edges, and assign a
positive weight to each edge on . Fix vertices and and consider the
set of paths that start at and end at , self-intersecting in any number
of places along the way. For each path, sum the weights of its edges, and then
list the path weights in increasing order. The asymptotic behaviour of this
sequence is described, in terms of the structure and type of strongly connected
components on the graph. As a special case, for a Markov chain the asymptotic
probability of paths obeys either a power law scaling or a weaker type of
scaling, depending on the structure of the transition matrix. This generalizes
previous work by Mandelbrot and others, who established asymptotic power law
scaling for special classes of Markov chains.Comment: 23 pages, 2 figure
How will disenfranchised Peoples adapt to Climate Change? Strengthening the Ecojustice Movement
The Fourth assessment of the Intergovernmental Panel on Climate Change (IPCC) acknowledged
That millions of people are currently, and will increasingly be, affected by the impacts of climate change, in the form of floods, droughts and other extreme events, as well as related threats to food security. In response to these global environmental changes, the international community, including civil society, is acting on the need for immediate adaptation measures and is developing strategies for future adaptation. However, the impacts of climate change are unevenly distributed, with many of the poorest, most vulnerable peoples experiencing the immediate effects of climate change, in the here and now. As the IPCC noted, developing countries are disproportionately affected by climate change and often, the least able to adapt due to lack of infrastructure and resources
Lightweight, self-evacuated insulation panels
Multilayer insulation of prefabricated panels is developed for cryogenic storage tanks. System utilizes panels of aluminized Mylar separated by sheets of low conductivity polyurethane foam. Panels are self-evacuated by cryopumping of gaseous carbon dioxide at time of use
Strengthening Resilience by thinking of Knowledge as a nutrient connecting the local person to global thinking: The case of Social Technology/Tecnologia Social
In this chapter, we describe the Knowledge as a Nutrient framework that emerged from these conversations. We describe how it relates to the Tecnologia Social policy approach to sustainability, developed in Brazil (Dagnino et al. 2004, Fundação Banco do Brasil 2009, Costa 2013), which is not well known in the anglophone world. Tecnologia Social was both inspired by and rooted in Paulo Freire’s pedagogical thinking (2000, Klix 2014).  We show how this framework has the potential to increase community resilience and adaptive capacity, not only for communities that face and must adapt to climate change but for all communities in the throes of complex social, ecological, economic and political transitions.This research was supported by the International Development Research Centre, grant number IDRC GRANT NO. 106002-00
Rigid open-cell polyurethane foam for cryogenic insulation
Lightweight polyurethane foam assembled in panels is effective spacer material for construction of self-evacuating multilayer insulation panels for cryogenic liquid tanks. Spacer material separates radiation shields with barrier that minimizes conductive and convective heat transfer between shields
Why did the pheasant cross the road? Long-term road mortality patterns in relation to management changes
Pheasants (Phasianus colchicus) are commonly killed on UK roads, presenting a threat to motorists and a loss to the game shooting industry. Pheasants may be inherently susceptible, or the recent increase in their artificial rearing and release may have exacerbated the situation, either through population increases or because artificial rearing has altered movement behaviour. We compared intra-annual patterns of roadkill reported in the UK from the 1960s (prior to the onset of mass release programmes) with that from the 2010s (when pheasant release was well established and widespread), considering roadkill sex and locations and accounting for changes in traffic levels. Pheasants in the UK are disproportionately likely to be reported killed on roads. However, this likelihood has not changed notably over the past 50 years. Instead, the timing of roadkill has changed. Pheasants in the 2010s are no longer susceptible during their breeding season, unlike in the 1960s, perhaps because relatively few breed successfully. Instead, roadkill first peaks in September–November as pheasants disperse from release pens, females first. Roadkill declines over winter, but when supplementary feeding ceases in February, we see a second peak in roadkill. Roadkill rates are higher in regions of the UK where there is little arable farming and hence natural food supplies are scarce.</jats:p
Global atmospheric sampling program
Automated instruments were installed on a commercial B-747 aircraft, during the program, to obtain baseline data and to monitor key atmospheric constituents associated with emissions of aircraft engines in order to determine if aircraft are contributing to pollution of the upper atmosphere. Data thus acquired on a global basis over the commercial air routes for 5 to 10 years will be analyzed. Ozone measurements in the 29,000 to 45,000 foot altitude were expanded over what has been available from ozonesondes. Limited aerosol composition measurements from filter samples show low levels of sulfates and nitrates in the upper troposphere. Recently installed instruments for measurement of carbon monoxide and condensation nuclei are beginning to return data
Developing and Researching PhET simulations for Teaching Quantum Mechanics
Quantum mechanics is difficult to learn because it is counterintuitive, hard
to visualize, mathematically challenging, and abstract. The Physics Education
Technology (PhET) Project, known for its interactive computer simulations for
teaching and learning physics, now includes 18 simulations on quantum mechanics
designed to improve learning of this difficult subject. Our simulations include
several key features to help students build mental models and intuitions about
quantum mechanics: visual representations of abstract concepts and microscopic
processes that cannot be directly observed, interactive environments that
directly couple students' actions to animations, connections to everyday life,
and efficient calculations so students can focus on the concepts rather than
the math. Like all PhET simulations, these are developed using the results of
education research and feedback from educators, and are tested in student
interviews and classroom studies. This article provides an overview of the PhET
quantum simulations and their development. We also describe research
demonstrating their effectiveness and share some insights about student
thinking that we have gained from our research on quantum simulations.Comment: accepted by American Journal of Physics; v2 includes an additional
study, more explanation of research behind claims, clearer wording, and more
reference
Stringent Phenomenological Investigation into Heterotic String Optical Unification
For the weakly coupled heterotic string (WCHS) there is a well-known factor
of twenty conflict between the minimum string coupling unification scale,
Lambda_H ~5x10^(17) GeV, and the projected MSSM unification scale, Lambda_U ~
2.5x10^(16) GeV, assuming an intermediate scale desert (ISD). Renormalization
effects of intermediate scale MSSM-charged exotics (ISME) (endemic to
quasi-realistic string models) can resolve this issue, pushing the MSSM scale
up to the string scale. However, for a generic string model, this implies that
the projected Lambda_U unification under ISD is accidental. If the true
unification scale is 5.0x10^(17) GeV, is it possible that illusionary
unification at 2.5x10^(17) GeV in the ISD scenario is not accidental? If it is
not, then under what conditions would the assumption of ISME in a WCHS model
imply apparent unification at Lambda_U when ISD is falsely assumed? Geidt's
"optical unification" suggests that Lambda_U is not accidental, by offering a
mechanism whereby a generic MSSM scale Lambda_U < Lambda_H is guaranteed. A
WCHS model was constructed that offers the possibility of optical unification,
depending on the availability of anomaly-cancelling flat directions meeting
certain requirements. This paper reports on the systematic investigation of the
optical unification properties of the set of stringent flat directions of this
model. Stringent flat directions can be guaranteed to be F-flat to all finite
order (or to at least a given finite order consistent with electroweak scale
supersymmetry breaking) and can be viewed as the likely roots of more general
flat directions. Analysis of the phenomenology of stringent flat directions
gives an indication of the remaining optical unification phenomenology that
must be garnered by flat directions developed from them.Comment: standard latex, 18 pages of tex
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