Showing 5031 - 5040 of 5831 Items
Activation of Hydrogen by Sterically Modulated Coinage Metal Catalysts via Mutual Quenching of Hard/Soft Acid/Base Mismatches
Date: 2024-01-01
Creator: Zach Leibowitz
Access: Open access
- To mitigate the devastating environmental impacts of climate change in the coming decades, it is imperative that we replace the use of fossil fuels with renewable energy sources such as wind, solar, and hydroelectric. As these renewable energy sources are inherently intermittent, there exists a need for sustainable mechanisms to store renewable energy for later use. While the direct use of dihydrogen (H2) as a combustible fuel would allow for energy storage without the harmful release of carbon dioxide (CO2) upon combustion, the practicality of H2 as a synthetic fuel is limited by its low volumetric energy density. Combining sustainable H2 production (e.g. electrolysis using energy from renewable sources) with subsequent carbon fixation (e.g. the hydrogenation of CO2) represents a promising pathway to the sustainable production of high-density synthetic fuels. We hypothesize that such a process could be catalyzed by an IPr**-supported catalyst containing a hard/soft acid/base (HSAB) mismatch, with a polarizable coinage metal acting as a soft acid. As such, the aim of our project is the construction of a catalogue of IPr**-supported copper, silver, and gold catalysts that we anticipate will facilitate the heterolysis of dihydrogen and subsequent hydrogenation of CO2. In the present paper, we report the synthesis and characterization of an IPr**-silver complex which will serve as a precursor to many of our proposed HSAB mismatch catalysts and discuss next steps as we construct our catalogue of catalysts.
Looking Ahead With the World in Their Hands: The Postsecondary Aspirations of East Island Youth
Date: 2016-05-01
Creator: Abby E Roy
Access: Open access
Modeling Strategic Behavior in the U.S. Senate Using Ideal Points with Social Interactions Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2017-05-01
Creator: Tucker Gordon
Access: Access restricted to the Bowdoin Community
Hunter-Gatherers: The Survival of the Foraging Practice In Modern States Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2015-05-01
Creator: Tristan C Van Kote
Access: Access restricted to the Bowdoin Community
*dhéĝhōm,*héshr, and *wek (earth, blood, and speech): an archaeological, genetic, and linguistic exploration of Indo-European origins
Date: 2017-05-01
Creator: Lara Bluhm
Access: Open access
- This project investigates strategies for learning about prehistoric languages that have left no written records. It focuses upon the origins and expansion of the Indo-European language family (the world’s largest by total speaking population, today including most of the languages between Iceland and India) and its associated speakers, who likely emerged during the Neolithic from someplace in eastern Europe or western Asia. There are two primary hypotheses regarding the origins of these languages and the so-called Indo-Europeans themselves. In one, it is argued that they arose via the expansion of agriculture out of Anatolia and into Europe, c. 5000 BC. The other, and leading, hypothesis suggests instead that the languages spread through migrations of highly mobile pastoralists outward from the Black Sea steppes at the end of the Neolithic, c. 3000 BC. This project will explore the developing interface between archaeology, genetics, and linguistics in prehistoric resarch. There are three main chapters: (1) some background and historical context about Indo-European studies; (2) an examination of methodological interaction among archaeology, linguistics, and genetics; and (3) a survey of various archaeological, genetic, and linguistic data as they pertain to the Indo-Europeans and the above two hypotheses of their origins.
Visions of Unity, Memories of Violence: American Civil Religion and the Japanese American Incarceration
Date: 2018-05-01
Creator: Brigitte Helene McFarland
Access: Open access
Benchmarking Ab Initio Computational Methods for the Quantitative Prediction of Sunlight-Driven Pollutant Degradation in Aquatic Environments
Date: 2016-05-01
Creator: Kasidet Trerayapiwat
Access: Open access
- Understanding the changes in molecular electronic structure following the absorption of light is a fundamental challenge for the goal of predicting photochemical rates and mechanisms. Proposed here is a systematic benchmarking method to evaluate accuracy of a model to quantitatively predict photo-degradation of small organic molecules in aquatic environments. An overview of underlying com- putational theories relevant to understanding sunlight-driven electronic processes in organic pollutants is presented. To evaluate the optimum size of solvent sphere, molecular Dynamics and Time Dependent Density Functional Theory (MD-TD-DFT) calculations of an aniline molecule in di↵erent numbers of water molecules using CAM-B3LYP functional yielded excited state energy and oscillator strength values, which were compared with data from experimental absorption spectra. For the first time, a statistical method of comparing experimental and theoretical data is proposed. Underlying Gaussian functions of absorption spectra were deconvoluted and integrated to calculate experimental oscillator strengths. A Matlab code written by Soren Eustis was utilized to decluster MD-TD-DFT results. The model with 256 water molecules was decided to give the most accurate results with optimized com- putational cost and accuracy. MD-TD-DFT calculations were then performed on aniline, 3-F-aniline, 4-F-aniline, 3-Cl-aniline, 4-MeOacetophenone, and (1,3)-dimethoxybenzophenone with CAM-B3LYP, PBE0, M06-2X, LCBLYP, and BP86 functionals. BP86 functional was determined to be the best functional. Github repository: https://github.com/eustislab/MD_Scripts
Fact vs. Faction: Polarization in the Information Age
Date: 2016-05-01
Creator: Noah Finberg
Access: Open access
- How can individuals in the contemporary media and political environment form better political beliefs? In chapter one, this thesis considers what it means to say American politics is polarized. It evaluates the extent of polarization in American politics. And it presents original evidence that suggests that just as the public and members of Congress have polarized, so too has American political discourse. Through the lens of political psychology, chapter two investigates how America’s polarized politics has influenced the quality of individuals’ beliefs. Chapter three explores the role that the media plays in encouraging or minimizing the biased information processing practices identified in chapter two. Finally, I conclude by arguing that individuals need to fundamentally rethink how they consume political information; advocate for the creation of a completely new social media platform specifically designed to encourage political deliberation; and outline what such a platform might look like.
Characterization and distribution of allatostatin type-C (AST-C) neuropeptides and receptors in crustaceans Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2016-05-01
Creator: Tess Lameyer
Access: Access restricted to the Bowdoin Community