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Full-Text Articles in Engineering

Thermal Removal Of Carbon Dioxide From The Atmosphere: Energy Requirements And Scaling Issues, Ted Von Hippel May 2018

Thermal Removal Of Carbon Dioxide From The Atmosphere: Energy Requirements And Scaling Issues, Ted Von Hippel

Publications

I conduct a systems-level study of direct air capture of CO2 using techniques from thermal physics. This system relies on a combination of an efficient heat exchanger, radiative cooling, and refrigeration, all at industrial scale and operated in environments at low ambient temperatures. While technological developments will be required for such a system to operate efficiently, those developments rest on a long history of refrigeration expertise and technology, and they can be developed and tested at modest scale. I estimate that the energy required to remove CO2 via this approach is comparable to direct air capture by other techniques. The …


Propeller Design Requirements For Quadcopters Utilizing Variable Pitch Propellers, Ian R. Mcandrew, Elena Navarro, Ken Witcher Feb 2018

Propeller Design Requirements For Quadcopters Utilizing Variable Pitch Propellers, Ian R. Mcandrew, Elena Navarro, Ken Witcher

Publications

Unmanned aerial vehicles, UAV, has increases in the drastically in these past several years since their costs reduced. This research is based and built upon previous research presented in a conference. With the advent of commercial Quadcopters, four propeller systems, are used, being designed and used to operate the advantages of both flight and hovering. The basic design of their propeller blades has not evolved from the early days of manned flight when wooden fixed blades were used. In this paper that expands upon previous findings and discussions it explores the historical developments. Furthermore, how the expansion and reduction in …


Mechanical And Electrical Characterization Of Carbon Fiber/Bucky Paper/Zinc Oxide Hybrid Composites, Suma Ayyagari, Marwan Al-Haik, Virginie Rollin Jan 2018

Mechanical And Electrical Characterization Of Carbon Fiber/Bucky Paper/Zinc Oxide Hybrid Composites, Suma Ayyagari, Marwan Al-Haik, Virginie Rollin

Publications

The quest for multifunctional carbon fiber reinforced composites (CFRPs) expedited the use of several nano reinforcements such as zinc oxide nanorods (ZnO) and carbon nanotubes (CNTs). Zinc oxide is a semi-conductor with good piezoelectric and pyroelectric properties. These properties could be transmitted to CFRPs when a nanophase of ZnO is embedded within CFRPs. In lieu of ZnO nanorods, Bucky paper comprising mat of CNTs could be sandwiched in-between composite laminae to construct a functionally graded composite with enhanced electrical conductivities. In this study, different configurations of hybrid composites based on carbon fibers with different combinations of ZnO nanorods and Bucky …