Showing 21 - 30 of 59 Items
Fast pyrolysis of lignins
Date: 2010-08-01
Creator: Sedat H. Beis, Saikrishna Mukkamala, Nathan Hill, Jincy Joseph, Cirila, Baker, Bruce Jensen, Elizabeth A. Stemmler, M. Clayton Wheeler, Brian G. Frederick
Access: Open access
- Three lignins: Indulin AT, Lignoboost™, and Acetocell lignin, were characterized and pyrolyzed in a continuous-fed fast pyrolysis process. The physical and chemical properties of the lignins included chemical composition, heat content, ash, and water content. The distributed activation energy model (DAEM) was used to describe the pyrolysis of each lignin. Activation energy distributions of each lignin were quite different and generally covered a broad range of energies, typically found in lignins. Process yields for initial continuous-fed fast pyrolysis experiments are reported. Bio-oil yield was low, ranging from 16 to 22%. Under the fast pyrolysis conditions used, the Indulin AT and Lignoboost™ lignin yielded slightly more liquid product than the Acetocell lignin. Lignin kinetic parameters and chemical composition vary considerably and fast pyrolysis processes must be specified for each type of lignin.
Deciphering the bacterial glycocode: Recent advances in bacterial glycoproteomics
Date: 2013-02-01
Creator: Scott A. Longwell, Danielle H. Dube
Access: Open access
- Bacterial glycoproteins represent an attractive target for new antibacterial treatments, as they are frequently linked to pathogenesis and contain distinctive glycans that are absent in humans. Despite their potential therapeutic importance, many bacterial glycoproteins remain uncharacterized. This review focuses on recent advances in deciphering the bacterial glycocode, including metabolic glycan labeling to discover and characterize bacterial glycoproteins, lectin-based microarrays to monitor bacterial glycoprotein dynamics, crosslinking sugars to assess the roles of bacterial glycoproteins, and harnessing bacterial glycosylation systems for the efficient production of industrially important glycoproteins. © 2012 Elsevier Ltd.
The Photodegradation of Endocrine Disrupting Compounds in Aqueous Solutions Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2014-05-01
Creator: Peyton C Morss
Access: Access restricted to the Bowdoin Community
Developing methods of transient absorption spectroscopy for the study of triplet state photoacids Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2023-01-01
Creator: Jack R Callahan
Access: Access restricted to the Bowdoin Community
Sorption of Cationic Heterocyclic Amines to Soils: Effects of Charge Delocalization and other Factors Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2023-01-01
Creator: Mariah McKenzie
Access: Access restricted to the Bowdoin Community
MnNiO3 revisited with modern theoretical and experimental methods
Date: 2017-11-07
Creator: Allison L. Dzubak, Chandrima Mitra, Michael Chance, Stephen Kuhn, Gerald E., Jellison, Athena S. Sefat, Jaron T. Krogel, Fernando A. Reboredo
Access: Open access
- MnNiO3 is a strongly correlated transition metal oxide that has recently been investigated theoretically for its potential application as an oxygen-evolution photocatalyst. However, there is no experimental report on critical quantities such as the band gap or bulk modulus. Recent theoretical predictions with standard functionals such as LDA+U and HSE show large discrepancies in the band gaps (about 1.23 eV), depending on the nature of the functional used. Hence there is clearly a need for an accurate quantitative prediction of the band gap to gauge its utility as a photocatalyst. In this work, we present a diffusion quantum Monte Carlo study of the bulk properties of MnNiO3 and revisit the synthesis and experimental properties of the compound. We predict quasiparticle band gaps of 2.0(5) eV and 3.8(6) eV for the majority and minority spin channels, respectively, and an equilibrium volume of 92.8 Å3, which compares well to the experimental value of 94.4 Å3. A bulk modulus of 217 GPa is predicted for MnNiO3. We rationalize the difficulty for the formation of ordered ilmenite-type structure with specific sites for Ni and Mn to be potentially due to the formation of antisite defects that form during synthesis, which ultimately affects the physical properties of MnNiO3.
Glycans in pathogenic bacteria - potential for targeted covalent therapeutics and imaging agents
Date: 2014-04-08
Creator: Van N. Tra, Danielle H. Dube
Access: Open access
- A substantial obstacle to the existing treatment of bacterial diseases is the lack of specific probes that can be used to diagnose and treat pathogenic bacteria in a selective manner while leaving the microbiome largely intact. To tackle this problem, there is an urgent need to develop pathogen-specific therapeutics and diagnostics. Here, we describe recent evidence that indicates distinctive glycans found exclusively on pathogenic bacteria could form the basis of targeted therapeutic and diagnostic strategies. In particular, we highlight the use of metabolic oligosaccharide engineering to covalently deliver therapeutics and imaging agents to bacterial glycans. © 2014 The Partner Organisations.
Assessing the Accuracy of Quantum Monte Carlo Pseudopotentials for CO2 Capture in Metal Organic Frameworks
Date: 2021-01-01
Creator: Chloe Renfro
Access: Open access
- As global emissions of CO2 and other greenhouse gases rises, global warming persists as an imminent threat to the environment and every day lives. To reduce greenhouse gas emissions in the atmosphere, there is a need to design materials to separate and capture the different gasses. Current gas capturing technologies lack efficiency and have extensive energy costs. A class of materials for CO2 capture is Molecular Organic Frameworks (MOFs). In order for a MOF to be efficient for this type of separation, the MOF needs to be able to selectively bind to the gas, while also not suffering a high energy cost to remove the gas and reuse the material. Computationally calculated binding energies are used to determine the usefulness of a MOF at capture and separation of a certain gas. Each computational method has its advantages and limitations. In this work, diffusion quantum Monte Carlo is being explored. This paper focuses on the accuracy of recently developed pseudopotentials for DMC use. These pseudopotentials have been tested on smaller molecules but have not been systematically tested for systems such as MOFs. Results from a DMC calculation of Zn-MOF-74 show a binding energy of -18.02 kJ/mol with an error bound of 16.74 kJ/mol. In order to assess the accuracy of the DMC results for binding energies of this magnitude the uncertainty need to be reduced, a subject of ongoing work.
Investigating the Effects of Mixed Solvents on the Excited State Proton Transfer Mechanisms of 8-Amino-2-naphthol This record is embargoed.
- Embargo End Date: 2027-05-19
Date: 2022-01-01
Creator: Alexander Avrom Kreines
Access: Embargoed
Ionic Liquids as Additives for Metal-Organic Framework Crystallization Access to this record is restricted to members of the Bowdoin community. Log in here to view.
- Restriction End Date: 2027-06-01
Date: 2024-01-01
Creator: Oliver Wang
Access: Access restricted to the Bowdoin Community