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The Removal Of Wood Components From Hardwood By Hot Water, Rory Jara
The Removal Of Wood Components From Hardwood By Hot Water, Rory Jara
Electronic Theses and Dissertations
Hot-water extraction of hemicelluloses from wood is a promising technology in the integrated biorefmery concept. A particular case is where the pulp industry makes co-products such as ethanol and acetic acid besides pulp thereby maximizing the value of biomass. Similarly, the oriented strand board (OSB) industry appears to be suitable for this technical approach as it is composed of large centralized facilities. Many studies have been carried out on the kinetics and mechanism of hot-water extraction of lignocellulosics. However, most of these studies were performed in batch reactors which are not best suited to determine intrinsic kinetics of hemicellulose dissolution …
Analysis Of Optical Spikes Reveals Dynamics Of Aggregates In The Twilight Zone, Nathan Briggs
Analysis Of Optical Spikes Reveals Dynamics Of Aggregates In The Twilight Zone, Nathan Briggs
Electronic Theses and Dissertations
The "biological pump," whereby phytoplankton grow in the surface ocean, aggregate, and sink, is a critical process contributing to global atmospheric CO2 drawdown and provides the vast majority of food for deep ocean and benthic ecosystems. The strength of this pump hinges on the amount of material that stick together to form larger aggregates, the sinking rates of these aggregates, and the rate at which they are consumed as they sink. However, marine aggregates, also called "marine snow," are often fragile and notoriously difficult to sample, their sinking rates are highly variable and difficult to quantify, and their concentrations can …
Late Spring And Summer Phytoplankton Community Dynamics On Georges Bank With Emphasis On Diatoms, Alexandrium Spp., And Other Dinoflagellates, Rachel Gettings
Late Spring And Summer Phytoplankton Community Dynamics On Georges Bank With Emphasis On Diatoms, Alexandrium Spp., And Other Dinoflagellates, Rachel Gettings
Electronic Theses and Dissertations
Georges Bank is a highly productive continental shelf system in the Northwest Atlantic that has historically supported a rich fishery. Part of that productivity stems from annual spring diatom bloom, which is followed by post-bloom populations of flagellates, including the toxic dinoflagellate Alexandrium spp., responsible for paralytic shellfish poisoning. While the general oceanography of Georges Bank has been well studied, far less is known about phytoplankton community dynamics or even basic species distributions and abundance. This thesis is driven in part by the possible competitive interactions among species of phytoplankton which are thought to influence Alexandrium blooms on the Bank. …
Higher-Order Physic For Modeling Ice Streams In Ice Sheets, Debra A. Kenneway
Higher-Order Physic For Modeling Ice Streams In Ice Sheets, Debra A. Kenneway
Electronic Theses and Dissertations
Ice streams are transitional between inland glaciers and ice shelves. Hence no stresses can be neglected. Ice streams are important dynamic features of a glacier; it is well known that ice streams drain up to 90% of the ice from an ice sheet. Herein I model ice streams as a multiphysics system of coupled components. This includes treating ice as a non-Newtonian fluid since empirical measurements show a power law relation between stress and strain rate. Sliding is a physical feature that must be included. This is done with a novel approach to sliding by way of a slippery layer. …
Improving Parallel I/O Performance Using Interval I/O, Jeremy Logan
Improving Parallel I/O Performance Using Interval I/O, Jeremy Logan
Electronic Theses and Dissertations
Today's most advanced scientific applications run on large clusters consisting of hundreds of thousands of processing cores, access state of the art parallel file systems that allow files to be distributed across hundreds of storage targets, and utilize advanced interconnections systems that allow for theoretical I/O bandwidth of hundreds of gigabytes per second. Despite these advanced technologies, these applications often fail to obtain a reasonable proportion of available I/O bandwidth. The reasons for the poor performance of application I/O include the noncontiguous I/O access patterns used for scientific computing, contention due to false sharing, and the somewhat finicky nature of …
Climate Investigations Using Ice Sheet And Mass Balance Models With Emphasis On North American Glaciation, Sean David Birkel
Climate Investigations Using Ice Sheet And Mass Balance Models With Emphasis On North American Glaciation, Sean David Birkel
Electronic Theses and Dissertations
This dissertation describes the application of the University of Maine Ice Sheet Model (UM-ISM) and Environmental Change Model (UM-ECM) to understanding mechanisms of ice-sheet/climate integration during ice ages. The UM-ECM, written by the author for this research, calculates equilibrium biome and snow/ice mass balance solutions for the globe based on modern input climatology and user-defined parameter values. The program was produced in conjunction with a National Science Foundation ITEST grant meant to seed inquiry-based classroom study of Earth systems using computer models. To that end, the UM-ECM serves as both a research and teaching tool. The model has a web-based …