Metallic Hydrides I: Hydrogen Storage and Other Gas-Phase Applications

A brief survey is given of the various classes of metal alloys and compounds that are suitable for hydrogen-storage and energy-conversion applications. Comparisons are made of relevant properties including hydrogen absorption and desorption pressures, total and reversible hydrogen-storage capacity, reaction-rate kinetics, initial activation requirements, susceptibility to contamination, and durability during long-term thermal cycling. Selected applications are hydrogen storage as a fuel, gas separation and purification, thermal switches, and sorption cryocoolers

Detecting and Explaining Crisis

Individuals on social media may reveal themselves to be in various states of crisis (e.g. suicide, self-harm, abuse, or eating disorders). Detecting crisis from social media text automatically and accurately can have profound consequences. However, detecting a general state of crisis without explaining why has limited applications. An explanation in this context is a coherent, concise subset of the text that rationalizes the crisis detection. We explore several methods to detect and explain crisis using a combination of neural and non-neural techniques. We evaluate these techniques on a unique data set obtained from Koko, an anonymous emotional support network available through various messaging applications. We annotate a small subset of the samples labeled with crisis with corresponding explanations. Our best technique significantly outperforms the baseline for detection and explanation.Comment: Accepted at CLPsych, ACL workshop. 8 pages, 5 figure

Sand dune field paleoenvironment, paleoecology, and human environmental interaction in the middle Tanana River Valley near the Gerstle River, subarctic Alaska: the late glacial to the middle Holocene

Thesis (M.A.) University of Alaska Fairbanks, 2017This study was conducted to explore paleoenvironmental change within the Gerstle-Sawmill Dune Field (GSDF), located just west of the Gerstle River in the middle Tanana River valley, Interior Alaska from the late Glacial to the middle Holocene. Specifically, this study was undertaken to document human-environment interaction on the landscape. Geoarchaeological methods were used in order to determine the history of sand dune development across the area, how the local ecological systems changed through time, and determine prehistoric human use of environment and response to environmental and ecological change. The data collected from these locations was used to create a model for sand dunes and human land use regarding local ecological stability and dynamic sand dune deposition. Patterns of human land use within the GSDF were then compared with data collected from sites in proximity to the GSDF to determine how this portion of the environment operated within the larger geographic area. This geoarchaeological research aids in understanding ecological patterning within terrestrial lowland systems from the Late Glacial to the Middle Holocene, with regard to human land use dynamics within a changing geomorphological system