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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 Aug 2019

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

Ted von Hippel

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 …


Global Validation Of Columnar Water Vapor Derived From Eos Modis-Maiac Algorithm Against The Ground-Based Aeronet Observations, Vitor S. Martins, Alexei Lyapustin, Yujie Wang, David M. Giles, Alexander Smirnov, Ilya Slutsker, Sergey Korkin May 2019

Global Validation Of Columnar Water Vapor Derived From Eos Modis-Maiac Algorithm Against The Ground-Based Aeronet Observations, Vitor S. Martins, Alexei Lyapustin, Yujie Wang, David M. Giles, Alexander Smirnov, Ilya Slutsker, Sergey Korkin

Vitor Martins

The water vapor is a relevant greenhouse gas in the Earth's climate system, and satellite products become one of the most effective way to characterize and monitor the columnar water vapor (CWV) content at global scale. Recently, a new product (MCD19) was released as part of MODIS (Moderate Resolution Imaging Spectroradiometer) Collection 6 (C6). This operational product from Multi-Angle Implementation for Atmospheric Correction (MAIAC) algorithm includes a high 1 km resolution CWV retrievals. This study presents the first global validation of MAIAC C6 CWV obtained from MODIS MCD19A2 product. This evaluation was performed using Aerosol Robotic Network (AERONET) observations at …


Seasonal And Interannual Assessment Of Cloud Cover And Atmospheric Constituents Across The Amazon (2000–2015): Insights For Remote Sensing And Climate Analysis, Vitor S. Martins, Evlyn M.L.M. Novo, Alexei Lyapustin, Luiz E.O.C. Aragão, Saulo R. Freitas, Claudio C.F. Barbosa May 2019

Seasonal And Interannual Assessment Of Cloud Cover And Atmospheric Constituents Across The Amazon (2000–2015): Insights For Remote Sensing And Climate Analysis, Vitor S. Martins, Evlyn M.L.M. Novo, Alexei Lyapustin, Luiz E.O.C. Aragão, Saulo R. Freitas, Claudio C.F. Barbosa

Vitor Martins

The quantitative assessment of cloud cover and atmospheric constituents improves our ability to exploit the climate feedback into the Amazon basin. In the 21st century, three droughts have already occurred in the Amazonia (e.g. 2005, 2010, 2015), inducing regional changes in the seasonal patterns of atmospheric constituents. In addition to climate, the atmospheric dynamic and attenuation properties are long-term challenges for satellite-based remote sensing of this ecosystem: high cloudiness, abundant water vapor content and biomass burning season. Therefore, while climatology analysis supports the understanding of atmospheric variability and trends, it also offers valuable insights for remote sensing applications. In this …


The Impact Of Trees On Passive Survivability During Extreme Heat Events In Warm And Humid Regions, Ulrike Passe, Janette R. Thompson, Baskar Ganapathysubramanian, Boshun Gao, Breanna L. Marmur Apr 2019

The Impact Of Trees On Passive Survivability During Extreme Heat Events In Warm And Humid Regions, Ulrike Passe, Janette R. Thompson, Baskar Ganapathysubramanian, Boshun Gao, Breanna L. Marmur

Breanna L. Marmur

Communities are increasingly affected by excessive heat. The likelihood of extreme heat events is predicted to increase in the Midwest region of the United States. By mid-century (2036–2065), one year out of 10 is projected to have a 5-day period that is 13°F warmer than a comparable earlier period (1976–2005). The frequency of high humidity/dew point days (“extra moist tropical air mass days,” MT++ synoptic climate classification system) has also increased significantly during a similar period (1975–2010) and between 2010 and 2014 included 8 of 26 heat events. This impact is exacerbated by the fact that many residences in low-income …


Approaches To Mitigating Decayed Buried Timber Within Railway Embankments, Barry A. Palynchuk Phd Sep 2007

Approaches To Mitigating Decayed Buried Timber Within Railway Embankments, Barry A. Palynchuk Phd

Barry A. Palynchuk PhD

During the last three years, several sinkholes have been observed along CPR railway lines in Southern Ontario. The sinkholes have formed as a result of the decay of buried timber trestles in railway embankments. Although it has not occurred the sinkholes could result in hazardous changes in track geometry under load. This study summarizes the site investigation results and remedial methods implemented at five sites in southern Ontario. Remedial methods include placement geosynthetic reinforcement, soil-cement column reinforcement and grouting of voids at the trestle bents. The design, installation methods and construction constraints for the remedial options are described in this …


Comparison Between Analytical Probabilistic And Computer Simulation Models, Using Current Design Examples, Barry A. Palynchuk Phd Sep 2003

Comparison Between Analytical Probabilistic And Computer Simulation Models, Using Current Design Examples, Barry A. Palynchuk Phd

Barry A. Palynchuk PhD

Closed form analytical expressions have been developed to solve several basic problems related to the hydrologic design of storm water management facilities. The collection of these analytical expressions is referred to as the Analytical Probabilistic Storm Water Models (APSWM). APSWM can be used as an alternative to the design storm simulation models in the design and analysis of storm water management facilities. In this paper, a comparison is made between APSWM and design storm simulation models as applied to an actual design case. Conventional outputs such as runoff volume, peak discharge, and peak discharge from detention ponds are reviewed and …