Browsing by Title
Now showing items 372-391 of 77475
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A 120-GHz Power Amplifier in 45-nm SiGe
(2022-12-02)As 5G cellular technologies are in the deployment stage and 6G technology is entering the research arena, the need for more bandwidth allocation has led to the drastic increase in frequency that has crossed the threshold into the sub-terahertz (sub-THz) region. This spectrum allows for larger bandwidths, but also brings challenges for implementation ... -
A 2-D simulation study on CO2ﾠsoluble surfactant for foam enhanced oil recovery
(2019)This paper probes the transport of CO2ﾠsoluble surfactant for foaming in porous media. We numerically investigate the effect of surfactant partitioning between the aqueous phase and the gaseous phase on foam transport for subsurface applications when the surfactant is injected in the CO2ﾠphase. A 2-D reservoir simulation is developed to quantify the ... -
A 200 MeV proton spin polarimeter
(1983)The design, construction, and calibration of a 2 MeV proton spin polarimeter are described. This polarimeter monitors the beam at the transfer point between the linear accelerator and the Alternating Gradient Synchrotron at Brookhaven National Laboratory. The polarimeter determines the beam polarization to an accuracy of 1% in less than ten minutes ... -
A 2D optical lattice for creating a 1-dimensional Fermi gas
(2009)Ultracold atomic gases can be prepared in laboratory environments with unrivaled control and purity. In one and a half decades the field has evolved from the first Bose condensates in dilute alkali gases to multiple species mixtures and degenerate Fermi systems. Combining quantum degenerate fermions and optical lattices enables the simulation of ... -
A 3.0 meter liquid mirror telescope
(2000)We constructed a 3.0 meter diameter f/1.5 Liquid Mirror Telescope (LMT) between 1990 and 1994 at the NASA Johnson Space Center, Houston, Texas. We have subsequently operated it since 1995 at the NASA Orbital Debris Observatory (NODO), Cloudcroft, NM. Employing an inexpensive rotating container of mercury as its primary parabolic mirror, the NASA LMT ... -
A 3D inﾠvitro model of patient-derived prostate cancer xenograft for controlled interrogation of inﾠvivo tumor-stromal interactions
(2016)Patient-derived xenograft (PDX) models better represent human cancer than traditional cell lines. However, the complex in vivo environment makes it challenging to employ PDX models to investigate tumor-stromal interactions, such as those that mediate prostate cancer (PCa) bone metastasis. Thus, we engineered a defined three-dimensional (3D) hydrogel ... -
A 3D inﾠvitro model of patient-derived prostate cancer xenograft for controlled interrogation of inﾠvivo tumor-stromal interactions
(2016)Patient-derived xenograft (PDX) models better represent human cancer than traditional cell lines. However, the complex in vivo environment makes it challenging to employ PDX models to investigate tumor-stromal interactions, such as those that mediate prostate cancer (PCa) bone metastasis. Thus, we engineered a defined three-dimensional (3D) hydrogel ... -
A 3D microfluidic tumor model to study immune cell infiltration into solid tumors
(2017-08-07)The tumor microenvironment consists of other cells besides cancer cells, including immune cells like T-cells, natural killer cells, and macrophages. The roles of these infiltrated cells, however, are diverse and can be both pro- or anti-tumorigenic. The effects of infiltrated natural killer cells are poorly characterized and highly misunderstood. To ... -
A 3D printable perfused hydrogel vascular model to assay ultrasound-induced permeability
(2022)The development of an in vitro model to study vascular permeability is vital for clinical applications such as the targeted delivery of therapeutics. This work demonstrates the use of a perfusion-based 3D printable hydrogel vascular model as an assessment for endothelial permeability and its barrier function. Aside from providing a platform that more ... -
A 5-km-thick reservoir with > 380,000 km3 of magma within the ancient Earth's crust
(2022)Several recent studies have argued that large, long-lived and molten magma chambers may not occur in the shallow Earth’s crust. Here we present, however, field-based observations from the Bushveld Complex that provide evidence to the contrary. In the eastern part of the complex, the magmatic layering continuously drapes across a ~ 4-km-high sloping ... -
'A Almshouse Ting Dat': Developments in Poor Relief and Child Welfare in Jamaica during the Interwar Years
(2013-07-24)This dissertation examines the development of poor relief and child welfare policy in Jamaica during the interwar years. It establishes the paradigms for accessing relief and how this influenced broader discussions of poverty, class and citizenship in society. As such it shows how these concerns about poverty, in the public sphere, influenced state ... -
A Ball and Beam Module for a Haptic Paddle Education Platform
(2017)Single degree of freedom force-feedback mechatronic devices, often called haptic paddles, are used in university curriculum as well as massive open online courses (MOOCs). While devices differ based on the goals of a given course, broadly speaking they provide hands-on learning for students studying mechatronics and dynamics. We introduce the third ... -
A Bayesian approach for capturing daily heterogeneity in intra-daily durations time series
(2013)Intra-daily financial durations time series typically exhibit evidence of long range dependence. This has motivated the introduction of models able to reproduce this stylized fact, like the Fractionally Integrated Autoregressive Conditional Duration Model. In this work we introduce a novel specification able to capture long range dependence. We propose ... -
A Bayesian approach to computing Brauer groups of cubic surfaces
(2022-12-02)We present an algorithm for computing the Brauer groups of cubic surfaces. The algorithm takes as input an equation for a cubic surface X and a confidence threshold 0.5 < r < 1 and outputs a candidate for the Brauer group of X and a confidence level > r for the result. The algorithm runs by sampling lifts of Frobenius at many primes of good reduction ... -
A Bayesian Approach to Social Structure Uncovers Cryptic Regulation of Group Dynamics in Drosophila melanogaster
(2015)Understanding the mechanisms that give rise to social structure is central to predicting the evolutionary and ecological outcomes of social interactions. Modeling this process is challenging, because all individuals simultaneously behave in ways that shape their social environments—a process called social niche construction (SNC). In earlier work, ... -
A Bayesian hierarchical model for detecting associations between haplotypes and disease using unphased SNPs
(2008)This thesis addresses using haplotypes to detect disease predisposing chromosomal regions based on a Bayesian hierarchical model for case-control data. By utilizing the Stochastic Search Variable Selection (SSVS) procedure of George and McCulloch (1997), the number of parameters is riot constrained by the sample size, as are the frequentist methods. ... -
A Bayesian Integrative Model for Genetical Genomics with Spatially Informed Variable Selection
(2014)We consider a Bayesian hierarchical model for the integration of gene expression levels with comparative genomic hybridization (CGH) array measurements collected on the same subjects. The approach defines a measurement error model that relates the gene expression levels to latent copy number states. In turn, the latent states are related to the ...
