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Kapitsa Anna K.A.,JSC
Acta Astronautica | Year: 2012

A combined method of liquid separation from a gasliquid flow is presented based on an analysis of existing methods of separation and experience gained from the Russian space stations Salut, Mir and the International Space Station. This method combines the advantages of both water-holding materials and semi-permeable membranes. The paper describes an actual device as well as laboratory test results for materials and the separator. The separator described has successfully been in experimental operation on the ISS since the 1st of September 2009. © 2012 Elsevier Ltd. Source

Grassberger P.,JSC
Journal of Statistical Mechanics: Theory and Experiment | Year: 2013

We study epidemic processes with immunization on very large 1-dimensional lattices, where at least some of the infections are non-local, with rates decaying as power laws p(x) ∼ x-σ-1 for large distances x. When starting with a single infected site, the cluster of infected sites stays always bounded if σ > 1 (and dies with probability 1, if its size is allowed to fluctuate down to zero), but the process can lead to an infinite epidemic for σ < 1. For σ < 0 the behavior is essentially of mean-field type, but for 0 < σ ≤ 1 the behavior is non-trivial, both for the critical and for supercritical cases. For critical epidemics we confirm a previous prediction that the critical exponents controlling the correlation time and the correlation length are simply related to each other, and we verify detailed field theoretic predictions for σ↘1/3. For σ = 1 we find generic power laws with continuously varying exponents even in the supercritical case, and confirm in detail the predicted Kosterlitz-Thouless nature of the transition. Finally, the mass N(t) of supercritical clusters grows for 0 < σ < 1 like a stretched exponential. This implies that networks embedded in 1-d space with power-behaved link distributions have infinite intrinsic dimension (based on the graph distance), but are not small world. © 2013 IOP Publishing Ltd and SISSA Medialab srl. Source

Grassberger P.,JSC | Grassberger P.,Max Planck Institute for the Physics of Complex Systems
Journal of Statistical Physics | Year: 2013

We extend a recent study of susceptible-infected-removed epidemic processes with long range infection (referred to as I in the following) from 1-dimensional lattices to lattices in two dimensions. As in I we use hashing to simulate very large lattices for which finite size effects can be neglected, in spite of the assumed power law p(x)∼{pipe}x{pipe}-σ-2 for the probability that a site can infect another site a distance vector x apart. As in I we present detailed results for the critical case, for the supercritical case with σ = 2, and for the supercritical case with 0<σ<2. For the latter we verify the stretched exponential growth of the infected cluster with time predicted by M. Biskup. For σ = 2 we find generic power laws with σ-dependent exponents in the supercritical phase, but no Kosterlitz-Thouless (KT) like critical point as in 1-d. Instead of diverging exponentially with the distance from the critical point, the correlation length increases with an inverse power, as in an ordinary critical point. Finally we study the dependence of the critical exponents on σ in the regime 0<σ<2, and compare with field theoretic predictions. In particular we discuss in detail whether the critical behavior for σ slightly less than 2 is in the short range universality class, as conjectured recently by F. Linder et al. As in I we also consider a modified version of the model where only some of the contacts are long range, the others being between nearest neighbors. If the number of the latter reaches the percolation threshold, the critical behavior is changed but the supercritical behavior stays qualitatively the same. © 2013 Springer Science+Business Media New York. Source

Grassberger P.,JSC | Grassberger P.,Institute for Advanced Studies in Basic Sciences
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2015

We present an efficient algorithm for simulating percolation transitions of mutually supporting viable clusters on multiplex networks (also known as "catastrophic cascades on interdependent networks"). This algorithm maps the problem onto a solid-on-solid-type model. We use this algorithm to study interdependent agents on duplex Erdös-Rényi (ER) networks and on lattices with dimensions 2, 3, 4, and 5. We obtain surprising results in all these cases, and we correct statements in the literature for ER networks and for two-dimensional lattices. In particular, we find that d=4 is the upper critical dimension and that the percolation transition is continuous for d≤4 but - at least for d≠3 - not in the universality class of ordinary percolation. For ER networks we verify that the cluster statistics is exactly described by mean-field theory but find evidence that the cascade process is not. For d=5 we find a first-order transition as for ER networks, but we find also that small clusters have a nontrivial mass distribution that scales at the transition point. Finally, for d=2 with intermediate-range dependency links we propose a scenario that differs from that proposed in W. Li et al. [Phys. Rev. Lett. 108, 228702 (2012)PRLTAO0031-900710.1103/PhysRevLett.108.228702]. © 2015 American Physical Society. Source

Home > Press > Dr. Ellen Ochoa To Receive the National Space Society's 2016 Space Pioneer Award for Non-Legislative Government Service Abstract: Dr. Ellen Ochoa is the winner of the Society's 2016 Space Pioneer Award for Non-Legislative Government Service. This award recognizes Ochoa's career serving as a professional engineer, a shuttle astronaut, the first hispanic woman in space, and subsequently in very important management positions in NASA, including her current position as the Director of NASA's Johnson Space Center. Ellen will accept the award on May 19 at the National Space Society's 2016 International Space Development Conference® (isdc.nss.org/2016/). This will be the 35th ISDC and will be held in San Juan, Puerto Rico, at the Sheraton Puerto Rico Hotel and Casino. The conference will run from May 18-22, 2016. The public is invited to attend ISDC in order to view the award presentation. About National Space Society NSS is an independent nonprofit educational membership organization dedicated to the creation of a spacefaring civilization. NSS is widely acknowledged as the preeminent citizen's voice on space, with over 50 chapters in the United States and around the world. The Society publishes Ad Astra magazine, an award-winning periodical chronicling the most important developments in space. To learn more, visit www.nss.org. Biographies for the Hopkins quote can be found at www.nss.org/about/bios/downs. About the The International Space Development Conference® (ISDC). National Space Society's International Space Development Conference (ISDC) 2016 (May 18-22) celebrates the increasingly collaborative, multinational, multidisciplinary, and interconnected nature of space development in the 21st century: Space Beyond Borders. If you seek to accelerate our pursuits beyond planet Earth and learn about the opportunities the emerging space economy can bring to science, technology and exploration, ISDC is the preeminent gathering place for you. NSS chose Puerto Rico as a surprisingly inexpensive travel destination. isdc.nss.org/2016/ About the Space Pioneer Award The Space Pioneer Award consists of a silvery pewter Moon globe cast by the Baker Art Foundry in Placerville, California, from a sculpture originally created by Don Davis, the well-known space and astronomical artist. The globe, as shown at left, which represents multiple space mission destinations and goals, sits freely on a brass support with a wooden base and brass plaque, which are created by the greatly respected Michael Hall's Studio Foundry of Driftwood, TX. NSS has several different categories under which the award is presented each year, starting in 1988. Some of the recent winners of Space Pioneer Awards include Elon Musk, Ray Bradbury, Robert Bigelow, citizen astronaut Anousheh Ansari, Dr. Kip Thorne, and the European Space Agency (ESA) Rosetta mission team. About Dr. Ellen Ochoa After receiving a Doctorate in Electrical Engineering from Stanford University in 1985, Dr. Ochoa did research at both Sandia National Laboratories and NASA Ames Research Center. Her achievements include significant engineering work in optics, in information (signal-to-noise) in images, and as Chief of the Intelligent Systems Technology Branch at NASA Ames. She also served as a shuttle astronaut for over a decade, making four flights, from 1993 to 2002. Ochoa then served as Deputy Director and Director of Flight Crew Operations at Johnson Space Center, focusing on the Astronaut Office and Aircraft Operations, and later as Deputy Center Director. Then, on the first day of 2013, Dr. Ochoa became the Director of NASA's Johnson Space Center, a position she currently holds. Johnson has been the focus for human spacecraft operations for most of NASA's history. Dr. Ochoa's directorship of JSC will have a significant impact on the future of human spaceflight. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

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