169,906 research outputs found
Organic geochemistry of Pliocene sediments in the core monsoon zone on the Indian Peninsula
No full textInorganic analyses of major, trace, and rare earth element concentrations for 30 bulk sediment samples at Site U1445 and additional samples from other sites in the Bay of Bengal for reference. Bulk sediment samples were freeze-dried and hand-powdered in an agate mortar and pestle prior to flux fusion for analyses of major elements with ICP-ES and an acid cocktail digestions for analyses of trace and rare earth elements on ICP-MS (Dunlea et al., 2015, doi:10.1002/2015PA002829).
Analyses of 57 bulk sediment samples from Site U1445 for bulk calcium carbonate, total organic carbon, total carbon, total acidified nitrogen, carbon isotopes of the total organic carbon, and the designation of visually lighter versus darker samples at similar depths.
Hydrogen isotopes and carbon isotope analyses of leaf wax fatty acids extracted from 57 samples at Site U1445. Measurements from fatty acid chainlengths C26, C28, and C30 are reported with their standard deviation. The correction for C3-C4 physiological differences in the hydrogen isotopes of C30 fatty acids is reported, estimating C3 vegetation as having a δ13C of -35.4 ‰ and C4 vegetation as -21.4‰
Pliocene expansion of C-4 vegetation in the core monsoon zone on the Indian Peninsula
No full text© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Dunlea, A. G., Giosan, L., & Huang, Y. Pliocene expansion of C-4 vegetation in the core monsoon zone on the Indian Peninsula. Climate of the Past, 16(6), (2020): 2533-2546, https://doi.org/10.5194/cp-16-2533-2020.The expansion of C4 vegetation during the Neogene was one of the largest reorganizations of Earth's terrestrial biome. Once thought to be globally synchronous in the late Miocene, site-specific studies have revealed differences in the timing of the expansion and suggest that local conditions play a substantial role. Here, we examine the expansion of C4 vegetation on the Indian Peninsula since the late Miocene by constructing a ∼6-million-year paleorecord with marine sediment from the Bay of Bengal at Site U1445, drilled during International Ocean Discovery Program Expedition 353. Analyses of element concentrations indicate that the marine sediment originates from the Mahanadi River in the Core Monsoon Zone (CMZ) of the Indian Peninsula. Hydrogen isotopes of the fatty acids of leaf waxes reveal an overall decrease in the CMZ precipitation since the late Miocene. Carbon isotopes of the leaf wax fatty acids suggest C4 vegetation on the Indian Peninsula existed before the end of the Miocene but expanded to even higher abundances during the mid-Pliocene to mid-Pleistocene (∼3.5 to 1.5 million years ago). Similar to the CMZ on the Indian Peninsula, a Pliocene expansion or re-expansion has previously been observed in northwest Australia and in East Africa, suggesting that these tropical ecosystems surrounding the Indian Ocean remained highly sensitive to changes in hydroclimate after the initial spread of C4 plants in late Miocene.This research has been supported by the Ocean and Climate Change Institute Postdoctoral Scholarship at Woods Hole Oceanographic Institution to Ann Dunlea, and the U.S. National Science Foundation to Liviu Giosan (grant no. NSF OCE-0652315). USSSP post-cruise support was provided to Expedition 353 shipboard participants Liviu Giosan and Yongsong Huang
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A globally conservative finite element MHD code and its application to the study of compact torus formation, levitation and magnetic compression
No full textThe DELiTE (Differential Equations on Linear Triangular Elements) framework
was developed for spatial discretisation of partial differential equations on
an unstructured triangular grid in axisymmetric geometry. The framework is
based on discrete differential operators in matrix form, which are derived
using linear finite elements and mimic some of the properties of their
continuous counterparts. A single-fluid two-temperature MHD code is implemented
in this framework. The inherent properties of the operators are used in the
code to ensure global conservation of energy, particle count, toroidal flux,
and angular momentum. The code was applied to study a novel experiment in which
a compact torus (CT), produced with a magnetized Marshall gun, is magnetically
levitated off an insulating wall and then magnetically compressed through the
action of currents in the levitation/compression coils located outside the
wall. We present numerical models for CT formation, levitation, and magnetic
compression, and comparisons between simulated and experimental diagnostics.Comment: 50 pages, 78 figures, partially presented in conference posters C.
Dunlea et al., Magnetic Compression at General Fusion - Experiment &
Simulation with a neutral fluid, APS_DPP 2017, EPS 2018, ICPP_201
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A ±25A Versatile Shunt-Based Current Sensor with 10kHz Bandwidth and ±0.25% Gain Error from -40°C to 85°C Using 2-Current Calibration
No full textAccurate current sensing is critical in many industrial applications, such as battery management and motor control. Precise shunt-based current sensors have been reported with gain errors of less than 1% over the industrial temperature range (-40°C to 85°C) [1]–[4]. However, since they are intended for coulomb counting, their bandwidth is limited to a few tens of Hz, making them unsuitable for battery impedance or motor-current sensing. This paper presents a current sensor with a wide (10kHz) bandwidth and a tunable temperature compensation scheme (TCS), which allows it to be flexibly used with different types of shunts while maintaining high accuracy. A low-cost room-temperature calibration scheme is proposed to optimize gain flatness over temperature by exploiting the shunt's self-heating at large currents. Over the industrial temperature range and a ±25A current range, it achieves state-of-the-art gain error (±0.25%) with both low-cost PCB and stable metal-alloy shunts.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
An Article About Albertus C. Van Raalte, Author Unknown, Except for Parts Taken from an Article by Anna C. Post
No full textAn article about Albertus C. Van Raalte, author unknown, except for parts taken from an article by Anna C. Post. The author knew first generation persons in the Holland settlement and therefore, the article has some value.https://digitalcommons.hope.edu/vrp_1890s/1012/thumbnail.jp
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