1,339 research outputs found
Fabrication of bismuth ferrite nanoparticles via pulsed laser ablation in liquid
No full textBismuth ferrite (BFO) is a room-temperature multiferroic material which exhibits an above-bandgap photovoltaic response as well as photocatalytic properties. This interesting coupling of effects means that BFO may have many useful applications in fields ranging from solar energy generation to multifunctional electronic devices. Herein, bismuth ferrite nanoparticles are fabricated using pulsed laser ablation in liquid (PLAL), a quick, simple, green technique of nanostructure generation in which a bulk solid target is irradiated with incident pulsed laser light in a liquid. The extreme temperatures and pressures generated in the resulting plasma can result in novel nanostructures and even metastable phases of nanomaterials not otherwise able to be created. Raman spectroscopy indicates the fabrication of a metastable phase of tetragonal-like BFO nanoparticles by pulsed laser ablation in liquid. These nanoparticles are also shown to be very small and monodisperse. Bulk solid solutions of BFO were prepared by conventional solid state sintering. Raman spectra of the bulk BFO samples were in agreement with published spectra for rhombohedrally distorted phase BFO with R3c symmetry. The bulk BFO was then ablated via PLAL, varying parameters of laser wavelength, energy, and liquid composition. PLAL yielded colloidal solutions of nanoparticles which were then characterized. Furthermore post laser irradiation (PLI) was carried out upon the nanoparticle solutions resulting in smaller and more monodisperse nanoparticles.M.S.Includes bibliographical referencesby Tyler Christian Butle
Global restructuring and the auto industry
No full textPublisher statement: This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Cambridge Journal of Regions, Economy and Society following peer review. The definitive publisher-authenticated version: Bailey, D. , De Ruyter, A. , Michie, J. and Tyler, P. (2010) Global restructuring and the auto industry. Cambridge Journal of Regions, Economy and Society, volume 3 (3): 311-318. is available online at: http://dx.doi.org/10.1093/cjres/rsq02
A partial state collocation method for covariance optimal control
No full textThesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged student-submitted from PDF version of thesis.Includes bibliographical references (pages 121-123).An overview is presented for two methods of incorporating the covariance in an optimal control problem. Including the covariance in the optimal control problem can be beneficial in the field of navigation where it is desirable to design trajectories which either minimize navigation error or maximize observability for instrument calibration. The full state collocation method uses Legendre Gauss Radau collocation to discretize the deterministic states and controls as well as the unique elements of the covariance matrix. The problem is then transcribed to a nonlinear progamming problem (NLP) and is solved with an NLP solver. This method, however, results in problems with many constraints and variables, which is computationally expensive. The partial state collocation method, the main focus of this thesis, collocates the deterministic states and controls but uses a shooting method to incorporate the covariance matrix. The problem is then transcribed to a nonlinear programming problem, which has fewer constraints and variables than the full state collocation method. Both of these methods are demonstrated by solving for the trajectory that minimizes the final position uncertainty for a spacecraft reentering Earth's atmosphere. The problem is tested with different sized covariance matrices, which shows how the time it takes to solve the problem increases as the covariance matrix increases in size. The partial state collocation method is generally faster and converges in fewer NLP iterations than the full state collocation method. As the covariance matrix increases in size, the time it takes to solve the problem increases at a smaller rate for the partial state collocation method.by Tyler J. Kapolka.S.M
The New Fugitive
No full textCry \u27Havoc!\u27 and Let Slip the Dogs of War, by James Rainsford
I Can\u27t Believe It\u27s Not Legal, by J. Tyler Lee, Jr.
It Was the One-Armed Author, by John Kinard
Spell-Check: Racisim or Pragmatism, by Jaymes Rainsford
Horoscopes from an Irish Wench, by Alissa Cooper
Coming Attraction
Memory Compression, Predictive Coding, and Temporal Overlap as a Computational Basis for Déjà Vu
No full textThis project develops a computational memory framework explaining déjà vu using established principles from predictive coding, memory compression, and hippocampal pattern completion. The account proposes that déjà vu arises when current perceptual input partially overlaps with compressed mnemonic representations, producing a false familiarity signal in the absence of a corresponding episodic memory. A slight predictive lead or temporal overlap in processing can amplify this effect, creating the brief but vivid impression of prior occurrence.
The attached whitepaper outlines the formal mechanism, including pattern collision and temporal compression, and provides falsifiable predictions for behavioral and neuroimaging studies. The framework avoids speculative explanations and situates déjà vu within standard models of cortical prediction and hippocampal computation.
Author: Tyler J. Goodell
Independent Researcher in Memory & Perceptio
Inducing Fe moment in LaFeSi with p-block element substitution
No full textWe studied the LaFeSi phase using density functional theory based full-potential linearized augmented plane wave (FP-LAPW) method. Specifically we examined the effect of p-element substitution on the stability and magnetic properties focusing on pathways to induce Fe magnetic moments. We demonstrate that either partial or complete substitutions at the Si 2 c-site by several p-block elements lead to non-zero Fe moments. Our theoretical study shows that partially substituted LaFeSi 1-y Ga y and LaFeSi 1-y Al y are more thermodynamically stable than the fully substituted LaFeGa and LaFeAl. We also found that the P substitutions, either partial or complete, have the most negative formation energies, however the compounds containing phosphorus are non-magnetic. Our work highlights a pathway toward manipulations of the otherwise quenched Fe-moments in LaFeSi-related compounds and help in advancing the potential magnetic functionalities of LaFeX compounds.This article is published as Chouhan, Rajiv K., Tyler J. Del Rose, Yaroslav Mudryk, and Vitalij K. Pecharsky. "Inducing Fe moment in LaFeSi with p-block element substitution." AIP Advances 12, no. 3 (2022): 035130.
DOI: 10.1063/9.0000334.
Copyright 2022 The Author(s).
Attribution 4.0 International (CC BY 4.0).
Posted with permission.
DOE Contract Number(s): AC02-07CH11358
Religious Communities and Human Flourishing
No full textTyler J. VanderWeele, PhD, is the John L. Loeb and Frances Lehman Loeb Professor of Epidemiology in the Departments of Epidemiology and Biostatistics at the Harvard T.H. Chan School of Public Health, and director of the Human Flourishing Program and co-director of the Initiative on Health, Religion and Spirituality at Harvard University.
He holds degrees from the University of Oxford, University of Pennsylvania, and Harvard University in mathematics, philosophy, theology, finance and biostatistics. His methodological research is focused on theory and methods for distinguishing between association and causation in the biomedical and social sciences and, more recently, on psychosocial measurement theory.
His empirical research spans psychiatric and social epidemiology; the science of happiness and flourishing; and the study of religion and health. He is the recipient of the 2017 Presidents’ Award from the Committee of Presidents of Statistical Societies (COPSS). He has published over 400 papers in peer-reviewed journals; is author of the books Explanation in Causal Inference (2015), Modern Epidemiology (2021), and Measuring Well-Being (2021); and also writes a monthly blog posting on topics related to human flourishing for Psychology Today
Impact of pre‐treatment (soaking or germination) on nutrient and anti‐nutrient contents, cooking time and acceptability of cooked red dry bean ( Phaseolus vulgaris L.) and chickpea ( Cicer arietinum L.) grown in Ethiopia
No full textPulses are processed in diverse ways prior to consumption. Soaking and germination are among the most common traditional, household‐level food processing strategies. This study was carried out to determine the effects of soaking, germination, cooking and their combinations on the contents of selected nutrients and anti‐nutrients of red dry bean and chickpea. In addition, the effects of pre‐treatment on cooking time and the acceptability of dishes prepared from red dry bean and chickpea were determined. The nutrient compositions (zinc, iron and calcium) of most soaked‐cooked and germinated‐cooked red dry bean and chickpea samples were not significantly different than those of respective controls. However, soaking and germination pre‐treatments significantly lowered the phytate and tannin contents of the red dry bean and chickpea samples, with a few exceptions, and overall, polyphenol contents were lower after soaking‐cooking than after germination‐cooking. Most scores for sensory attributes of bean‐based and chickpea‐based dishes prepared from soaked or germinated samples were not significantly different than those of the controls. For most red dry bean and chickpea samples, longer germination times yielded superior results in terms of reductions in cooking time, tannin content, and phytate:zinc and phytate:iron molar ratio
Impact of household food processing strategies on antinutrient (phytate, tannin and polyphenol) contents of chickpeas ( Cicer arietinum L.) and beans ( Phaseolus vulgaris L.): a review
No full textPulses, which include beans and chickpeas, are major constituents of the human diet. They are important sources of energy and nutrients, particularly protein, folate and minerals. However, they also contain antinutrients which bind minerals, mainly iron and zinc, rendering them less bioavailable or unavailable for absorption. The levels of these antinutrients may be reduced by food processing techniques such as soaking and germination. Researchers have used these techniques in a number of studies; however, there is no consensus regarding the optimum processing conditions for reduction in the levels of these antinutrients. Thus, this review was conducted to describe the results of studies on soaking and germination of chickpeas and beans. A systematic search was carried out utilising Food Science and Technology Abstracts (FSTA) (1969 to present), Web of Science (1899 to present) and Scopus (1823 to present). A total of thirty‐three articles were reviewed. Both soaking and germination resulted in significant but variable degrees of reduction in levels of antinutrients in most studies
Big change or much ado about nothing?: the impact of Bill C-24 and the Bipartisan Campaign Reform Act on political fundraising in Canada and the United States
No full textRecent changes to campaign finance laws in Canada and the United States provide researchers with a unique opportunity for comparative studies on the effects of reform on fundraising at the grassroots level. In an effort to contribute to the understanding of these recent reforms the following comparative case study examines the effects of Bill C-24 (2003) and the Bipartisan Campaign Reform Act of 2002 on the campaigns of one Canadian Member of Parliament and one American Congressional Representative. The study suggests that while the impact of the most recent American reforms has been somewhat exaggerated by scholars, changes to campaign finance laws in Canada have caused substantial change at both the national and grassroots level
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