scholarly journals Controlled levitation of nanostructured thin films for sun-powered near-space flight

2021 ◽  
Vol 7 (7) ◽  
pp. eabe1127
Author(s):  
Mohsen Azadi ◽  
George A. Popov ◽  
Zhipeng Lu ◽  
Andy G. Eskenazi ◽  
Avery Ji Won Bang ◽  
...  
Keyword(s):  
Space Flight ◽  
Light Field ◽  
Vacuum Chamber ◽  
Low Cost ◽  
Nanostructured Surface ◽  
Near Space ◽  
Recoil Force ◽  
Long Duration ◽  
Gas Molecules ◽  
Optically Trapped

We report light-driven levitation of macroscopic polymer films with nanostructured surface as candidates for long-duration near-space flight. We levitated centimeter-scale disks made of commercial 0.5-micron-thick mylar film coated with carbon nanotubes on one side. When illuminated with light intensity comparable to natural sunlight, the polymer disk heats up and interacts with incident gas molecules differently on the top and bottom sides, producing a net recoil force. We observed the levitation of 6-mm-diameter disks in a vacuum chamber at pressures between 10 and 30 Pa. Moreover, we controlled the flight of the disks using a shaped light field that optically trapped the levitating disks. Our experimentally validated theoretical model predicts that the lift forces can be many times the weight of the films, allowing payloads of up to 10 milligrams for sunlight-powered low-cost microflyers at altitudes of 50 to 100 km.

The Design, Building and Testing of a Trans-Atlantic Autonomous Sailboat

2015 ◽  
Author(s):  
Satchel B. Douglas ◽  
Nolan R. Conway ◽  
Matthew B. Weklar
Keyword(s):  
Open Source ◽  
Autonomous Vehicles ◽  
Low Cost ◽  
Design Decisions ◽  
Hull Form ◽  
Construction Methods ◽  
Autonomous Surface Vehicles ◽  
Marine Industry ◽  
Long Duration ◽  
Rotating Wing

The use of autonomous vehicles is growing in all industries. However, there are no open-source autonomous surface vehicles available in the marine industry. This paper details the design decisions made, construction methods used, and testing performed on a low-cost, open-source vessel. The vessel was designed to cross the Atlantic Ocean as a means of proving its ability to survive the harsh marine environment. A trimaran hull form and free rotating wing sail were used because the combination provided good righting characteristics, durability and low power consumption. The vessel has been shown to navigate autonomously. Total costs were less than $4000 dollars, excluding labor. Vessels of this type could be used for long duration missions recording data in the open ocean at extremely low cost.

scholarly journals A Review of the Use of Methadone for the Treatment of Chronic Noncancer Pain

2005 ◽  
Vol 10 (3) ◽  
pp. 133-144 ◽  
Author(s):  
Mary E Lynch
Keyword(s):  
Chronic Pain ◽  
Low Cost ◽  
Interindividual Variation ◽  
Duration Of Action ◽  
Chronic Noncancer Pain ◽  
Opioid Dose ◽  
Long Duration ◽  
Attractive Option ◽  
Noncancer Pain ◽  
High Bioavailability

Methadone, although having been available for approximately half a century, is now receiving increasing attention in the management of chronic pain. This is due to recent research showing that methadone exhibits at least three different mechanisms of action including potent opioid agonism, N-methyl-D-aspartate antagonism and monoaminergic effects. This, along with methadone's excellent oral and rectal absorption, high bioavailability, long duration of action and low cost, make it a very attractive option for the treatment of chronic pain. The disadvantages of significant interindividual variation in pharmacokinetics, graduated dose equivalency ratios based on prerotation opioid dose when switching from another opioid, and the requirement for special exemption for prescribing methadone make it more complicated to use. The present review is intended to educate physicians interested in adding methadone to their armamentarium for assisting patients with moderate to severe pain.

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