8,527 research outputs found
Living In the KnowlEdge Society (LIKES) Initiative and iSchools' Focus on the Information Field
In this poster, we describe the similarities between the Living In the KnowlEdge Society (LIKES) project and iSchools – both focus on the information field. This might lead to future collaborations between the two. One of the LIKES objectives is to spread computational thinking, fundamental CS/IT paradigms, key computing concepts and ICT paradigms across the Knowledge Society. This is analogous to iSchools’ vision of education for thorough understanding of information, IT and their applications. In the previous three LIKES workshops, participants from various disciplines had an intense discussion about grand challenges to incorporate computing/IT in their disciplines. All iSchools have courses that teach computing and information-related topics. If those courses can be expanded for other non-computing disciplines on their campuses with support from experiences of LIKES, it would further empower professionals in the iField
An analytical and computational investigation of shock-induced vortical flows
Interaction of a shock wave with a jet of light gas
surrounded by an ambient heavy gas generates vorticity
around the perimeter of the jet. This rolls the jet into
a pair of counterrotating, finite-core size vortices. The
canonical problem is the two-dimensional, unsteady interaction in a finite channel. The dynamics of the vortex
pair are controlled by the incident shock strength, the
light/heavy gas density ratio, and the channel spacing.
Analytical expressions are derived which describe the
strength and motion of the vortex pair as a function
of these parameters. Numerical simulations shQw good
agreement with these models. Various perturbations on
the single jet flow are investigated with the goal of destabilizing the vortex pair and further enhancing the mixing. Single jet shape perturbations are relatively ineffective. However, an array of jets can dramatically increase the mixing. Another effective method is to form a reflected shock. Finally, an analogy to the corresponding
three-dimensional, steady flows is demonstrated both
qualitatively and quantitatively. This allows an understanding of the dynamics and mixing of the two imensional, unsteady flows to be directly applied to
three-dimensional, steady flows typical of SCRAMJET
designs
An optical tweezer actuated, nanoaperture-grid based optofluidic microscope implementation method
We report a novel grid based Optofluidic Microscope (OFM) method where a closely spaced 2D grid of nanoapertures (diameter = 100 nm, separation = 2.5 μm) provided patterned illumination. We achieved a one-to-one mapping of the light transmissions through the nanoapertures onto a high-speed CCD camera. By optically tweezing a targeted sample across the grid in a controlled fashion and recording the time varying light reception from the nanoapertures, we were able to generate high-resolution images of the sample. The achievable resolution limit of the prototype was ~ 110 nm (Sparrow’s criterion) under optimal conditions. We demonstrated the technique by imaging polystyrene beads and pollen spores
Hemosuccus Pancreaticus as a Rare Complication of Bariatric Surgery.
Hemosuccus pancreaticus is a rare cause of gastrointestinal bleeding from the duct of Wirsung into the duodenum via the ampulla of Vater. Hemosuccus pancreaticus is difficult to diagnose because the bleeding is usually intermittent, and the clinical findings are often discordant. Patients present with pain, either left upper quadrant or epigastric, and bleeding, which may present as melena, bright red blood per rectum, or even shock, if the hemorrhage is severe. Hemosuccus pancreaticus is usually caused by rupture of a pseudoaneurysm of a peri-pancreatic artery, often the splenic artery, in the setting of pancreatitis; other causes are very rare. In this report, for the first time to our knowledge, we present a case of hemosuccus pancreaticus that occurred as a complication of bariatric surgery
Between a Rock and a Cell Phone: Social Media Use during Mass Protests in Iran, Tunisia and Egypt
In this paper we examine the use of social media, and especially Twitter, in Iran, Tunisia and Egypt during the mass political demonstrations and protests in June 2009, December 2010 - January 2011, and February 2011, respectively. We compare this usage with methods and findings from other studies on the use of Twitter in emergency situations, such as natural and man-made disasters. We draw on our own experiences and participant-observations as an eyewitness in Iran (first author), and on Twitter data from Iran, Tunisia and Egypt. In these three cases, Twitter filled a unique technology and communication gap at least partially. We summarize suggested directions for future research with a view of placing this work in the larger context of social media use in conditions of crisis and social convergence
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