Required separation distance between decks and at abutments of a bridge crossing a canyon site to avoid seismic pounding

2009 ◽  
pp. n/a-n/a ◽  
Author(s):  
Kaiming Bi ◽  
Hong Hao ◽  
Nawawi Chouw
Keyword(s):  
Separation Distance ◽  
Bridge Crossing ◽  
Seismic Pounding

Seismic Pounding Model Using Hertzian Contact

2018 ◽  
Author(s):  
Arthur Mereles ◽  
Marcus Varanis ◽  
José Manoel Balthazar ◽  
Angelo Marcelo Tusset
Keyword(s):  
Hertzian Contact ◽  
Seismic Pounding

scholarly journals Azimuthal Anchoring Strength in Photopatterned Alignment of a Nematic

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 675
Author(s):  
H. Nilanthi Padmini ◽  
Mojtaba Rajabi ◽  
Sergij V. Shiyanovskii ◽  
Oleg D. Lavrentovich
Keyword(s):  
Liquid Crystal ◽  
Point Defects ◽  
Elastic Energy ◽  
Separation Distance ◽  
Thin Layers ◽  
Uv Exposure ◽  
Surface Anchoring ◽  
Anchoring Strength ◽  
Spatially Varying

Spatially-varying director fields have become an important part of research and development in liquid crystals. Characterization of the anchoring strength associated with a spatially-varying director is difficult, since the methods developed for a uniform alignment are seldom applicable. Here we characterize the strength of azimuthal surface anchoring produced by the photoalignment technique based on plasmonic metamsaks. The measurements used photopatterned arrays of topological point defects of strength +1 and −1 in thin layers of a nematic liquid crystal. The integer-strength defects split into pairs of half-integer defects with lower elastic energy. The separation distance between the split pair is limited by the azimuthal surface anchoring, which allows one to determine the strength of the latter. The strength of the azimuthal anchoring is proportional to the UV exposure time during the photoalignment of the azobenzene layer.

scholarly journals Aerial Transmission of the SARS-CoV-2 Virus through Environmental E-Cigarette Aerosols: Implications for Public Policies

2021 ◽  
Vol 18 (4) ◽  
pp. 1437
Author(s):  
Roberto A. Sussman ◽  
Eliana Golberstein ◽  
Riccardo Polosa
Keyword(s):  
Emission Rate ◽  
Respiratory Activity ◽  
Separation Distance ◽  
Mitigation Strategies ◽  
Relative Risks ◽  
Respiratory Flow ◽  
Outdoor Spaces ◽  
Direct Exposure ◽  
Social Separation ◽  
Indoor Spaces

We discuss the implications of possible contagion of COVID-19 through e-cigarette aerosol (ECA) for prevention and mitigation strategies during the current pandemic. This is a relevant issue when millions of vapers (and smokers) must remain under indoor confinement and/or share public outdoor spaces with non-users. The fact that the respiratory flow associated with vaping is visible (as opposed to other respiratory activities) clearly delineates a safety distance of 1–2 m along the exhaled jet to prevent direct exposure. Vaping is a relatively infrequent and intermittent respiratory activity for which we infer a mean emission rate of 79.82 droplets per puff (6–200, standard deviation 74.66) comparable to mouth breathing, it adds into shared indoor spaces (home and restaurant scenarios) a 1% extra risk of indirect COVID-19 contagion with respect to a “control case” of existing unavoidable risk from continuous breathing. As a comparative reference, this added relative risk increases to 44–176% for speaking 6–24 min per hour and 260% for coughing every 2 min. Mechanical ventilation decreases absolute emission levels but keeps the same relative risks. As long as direct exposure to the visible exhaled jet is avoided, wearing of face masks effectively protects bystanders and keeps risk estimates very low. As a consequence, protection from possible COVID-19 contagion through vaping emissions does not require extra interventions besides the standard recommendations to the general population: keeping a social separation distance of 2 m and wearing of face masks.

scholarly journals Anti-Reflection Nanostructures on Tempered Glass by Dynamic Beam Shaping

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 289
Author(s):  
Petr Hauschwitz ◽  
Jan Brajer ◽  
Danijela Rostohar ◽  
Jaromír Kopeček ◽  
Tomáš Mocek ◽  
...  
Keyword(s):  
Mobile Phones ◽  
Thermal Damage ◽  
Pulsed Laser ◽  
Processing Parameters ◽  
Beam Shaping ◽  
Separation Distance ◽  
Tempered Glass ◽  
Fundamental Wavelength ◽  
Speed Up ◽  
Scanning Head

Reflectivity and surface topography of tempered glass were modified without any thermal damage to the surroundings by utilizing 1.7 ps ultrashort pulsed laser on its fundamental wavelength of 1030 nm. To speed up the fabrication, a dynamic beam shaping unit combined with a galvanometer scanning head was applied to divide the initial laser beam into a matrix of beamlets with adjustable beamlets number and separation distance. By tuning the laser and processing parameters, reflected intensity can be reduced up to 75% while maintaining 90% of transparency thus showing great potential for display functionalization of mobile phones or laptops.

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