11,007 research outputs found
Deposition of particle pollution in turbulent forced-air cooling
Rotating fans are the prevalent forced cooling method for heat generating
equipment and buildings. As the concentration of atmospheric pollutants has
increased, the accumulation of microscale and nanoscale particles on surfaces
due to advection-diffusion has led to adverse mechanical, chemical and
electrical effects that increase cooling demands and reduce the reliability of
electronic equipment. Here, we uncover the mechanisms leading to enhanced
deposition of particle matter (PM and PM) on surfaces due to
turbulent axial fan flows operating at Reynolds numbers, .
Qualitative observations of long-term particle deposition from the field were
combined with \textit{in situ} particle image velocimetry on a
telecommunications base station, revealing the dominant role of impingement
velocity and angle. Near-wall momentum transport for were
explored using a quadrant analysis to uncover the contributions of turbulent
events that promote particle deposition through turbulent diffusion and eddy
impaction. By decomposing these events, the local transport behaviour of fine
particles from the bulk flow to the surface has been categorised. The
transition from deposition to clean surfaces was accompanied by a decrease in
shear velocity, turbulent stresses, and particle sweep motions with lower flux
in the wall-normal direction. Finally, using these insights, selective
filtering of coarse particles was found to promote the conditions that enhance
the deposition of fine particle matter
SmartMirror: A Glance into the Future
In todays society, information is available to us at a glance through our phones, our laptops, our desktops, and more. But an extra level of interaction is required in order to access the information. As technology grows, technology should grow further and further away from the traditional style of interaction with devices. In the past, information was relayed through paper, then through computers, and in todays day and age, through our phones and multiple other mediums. Technology should become more integrated into our lives - more seamless and more invisible. We hope to push the envelope further, into the future. We propose a new simple way of connecting with your morning newspaper. We present our idea, the SmartMirror, information at a glance. Our system aims to deliver your information quickly and comfortably, with a new modern aesthetic. While modern appliances require input through modules such as keyboards or touch screen, we hope to follow a model that can function purely on voice and gesture. We seek to deliver your information during your morning routine and throughout the day, when taking out your phone is not always possible. This will cater to a larger audience base, as the average consumer nowadays hopes to accomplish tasks with minimal active interaction with their adopted technology. This idea has many future applications, such as integration with new virtual or augmented reality devices, or simplifying consumer personal media sources
Reading Wikipedia to Answer Open-Domain Questions
This paper proposes to tackle open- domain question answering using Wikipedia
as the unique knowledge source: the answer to any factoid question is a text
span in a Wikipedia article. This task of machine reading at scale combines the
challenges of document retrieval (finding the relevant articles) with that of
machine comprehension of text (identifying the answer spans from those
articles). Our approach combines a search component based on bigram hashing and
TF-IDF matching with a multi-layer recurrent neural network model trained to
detect answers in Wikipedia paragraphs. Our experiments on multiple existing QA
datasets indicate that (1) both modules are highly competitive with respect to
existing counterparts and (2) multitask learning using distant supervision on
their combination is an effective complete system on this challenging task.Comment: ACL2017, 10 page
Energetics of Protein-DNA Interactions
Protein-DNA interactions are vital for many processes in living cells,
especially transcriptional regulation and DNA modification. To further our
understanding of these important processes on the microscopic level, it is
necessary that theoretical models describe the macromolecular interaction
energetics accurately. While several methods have been proposed, there has not
been a careful comparison of how well the different methods are able to predict
biologically important quantities such as the correct DNA binding sequence,
total binding free energy, and free energy changes caused by DNA mutation. In
addition to carrying out the comparison, we present two important theoretical
models developed initially in protein folding that have not yet been tried on
protein-DNA interactions. In the process, we find that the results of these
knowledge-based potentials show a strong dependence on the interaction distance
and the derivation method. Finally, we present a knowledge-based potential that
gives comparable or superior results to the best of the other methods,
including the molecular mechanics force field AMBER99
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