1,283 research outputs found
Descreening of Field Effect in Electrically Gated Nanopores
This modeling work investigates the electrical modulation characteristics of
field-effect gated nanopores. Highly nonlinear current modulations are observed
in nanopores with non-overlapping electric double layers, including those with
pore diameters 100 times the Debye screening length. We attribute this extended
field-effect gating to a descreening effect, i.e. the counter-ions do not fully
relax to screen the gating potential due to the presence of strong ionic
transport
STM Studies of Synthetic Peptide Monolayers
We have used scanning probe microscopy to investigate self-assembled
monolayers of chemically synthesized peptides. We find that the peptides form a
dense uniform monolayer, above which is found a sparse additional layer. Using
scanning tunneling microscopy, submolecular resolution can be obtained,
revealing the alpha helices which constitute the peptide. The nature of the
images is not significantly affected by the incorporation of redox cofactors
(hemes) in the peptides.Comment: 4 pages, 3 figures (4 gifs); to appear in the Proceedings of the
XIIth Int. Winterschool on Electronic Properties of Novel Materials
"Molecular Nanostructures", Kirchberg/Tyrol, Febr. 199
Lantana urticoides Hayek
https://thekeep.eiu.edu/herbarium_specimens_byname/18905/thumbnail.jp
A VHDL Core for Intrinsic Evolution of Discrete Time Filters with Signal Feedback
The design of an Evolvable Machine VHDL Core is presented, representing a discrete-time processing structure capable of supporting control system applications. This VHDL Core is implemented in an FPGA and is interfaced with an evolutionary algorithm implemented in firmware on a Digital Signal Processor (DSP) to create an evolvable system platform. The salient features of this architecture are presented. The capability to implement IIR filter structures is presented along with the results of the intrinsic evolution of a filter. The robustness of the evolved filter design is tested and its unique characteristics are described
A singular solace: an ecclesiastical history of Haddington, 1560-2000
After a Preamble covering the evolution of the church in Haddington during the medieval period, this dissertation will provide a case-study of how the church in a small, semi-rural burgh evolved from 1560 to 2000 in the context of developments within the Scottish church, Scottish society and the local community. It will show that the wealth of the burgh facilitated the building of an impressive gothic church; the evolution of St Mary’s into a collegiate church; and how the building was severely damaged in 1548/9; how it was converted into a parish church after the Reformation. The study will also show that the first Protestant minister was appointed in 1562; that St Mary’s was Presbyterian during the religious controversies of the seventeenth century; that during the eighteenth century and early nineteenth Episcopal, Burgher, Antiburgher, Relief, Haldaneite, Independent, Original Secession, and Methodist meeting-houses were planted in the burgh; that because of the dominance of the established church the Disruption had a limited impact in the town; that in 1862 a Roman Catholic Church was opened; and that, after a burst of energy in the post-war period, the churches in the burgh went into numerical decline. This dissertation will also demonstrate that the evolution of the church in Haddington was influenced by a number of factors, that it had several distinctive features; and that the three main characteristics of the church in Haddington were continuity, diversity and being ‘a singular solace’ for the community
Minister of the Gospel at Haddington The Life and Work of the Reverend John Brown (1722-1787)
This dissertation takes a fresh look at the life and work of the Reverend John Brown (1722-1787), minister of the First Secession Church in Haddington and Professor of Divinity in the Associate (Burgher) Synod, who is best known as the author of The Self-Interpreting Bible (1778). Brown was born in humble circumstances in Perthshire; ‘attached’ himself to the 1733 Secession, and aspired to become one of its ministers. However, his lack of formal education, the death of his parents, and accusations that to learn Greek and Hebrew he had entered a Faustian pact, meant he struggled to achieve his goal. However, after serving as a shepherd, pedlar, soldier and teacher and studying part-time for the ministry, he was ordain in July 1751. Brown soon established himself as an effective pastor and respected presbyter and, in 1753, was elected moderator of the Associate (Burgher) Synod. After publishing four works, including a history of the Secession, in 1767 Brown was appointed to the non-stipendiary post of Professor of Divinity and each summer students came to Haddington to study under him. In 1771 Brown began to correspond with Selina, Countess of Huntingdon, one of the leaders of the Evangelical Revival in England and Wales, who requested a copy of his Systematic Theology for use in her college in Trefecca in mid-Wales. Brown was a prolific religious writer and published sixty books, pamphlets and tracts, including A Dictionary of the Bible (1769), which attracted interest outside Scotland; The Self-Interpreting Bible (1778), upon which his reputation largely rests; and a History of the British Churches (1784), which is perhaps his ablest work. The main sources for Brown’s life are accounts written by himself and members of his family; profiles in his Dictionary and Bible and Robert MacKenzie’s biography, John Brown of Haddington (1918)
The SWELLS Survey. I. A large spectroscopically selected sample of edge-on late-type lens galaxies
The relative contribution of baryons and dark matter to the inner regions of
spiral galaxies provides critical clues to their formation and evolution, but
it is generally difficult to determine. For spiral galaxies that are strong
gravitational lenses, however, the combination of lensing and kinematic
observations can be used to break the disk-halo degeneracy. In turn, such data
constrain fundamental parameters such as i) the mass density profile slope and
axis ratio of the dark matter halo, and by comparison with dark matter-only
numerical simulations the modifications imposed by baryons; ii) the mass in
stars and therefore the overall star formation efficiency, and the amount of
feedback; iii) by comparison with stellar population synthesis models, the
normalization of the stellar initial mass function. In this first paper of a
series, we present a sample of 16 secure, 1 probable, and 6 possible strong
lensing spiral galaxies, for which multi-band high-resolution images and
rotation curves were obtained using the Hubble Space Telescope and Keck-II
Telescope as part of the Sloan WFC Edge-on Late-type Lens Survey (SWELLS). The
sample includes 8 newly discovered secure systems. [abridged] We find that the
SWELLS sample of secure lenses spans a broad range of morphologies (from
lenticular to late-type spiral), spectral types (quantified by Halpha
emission), and bulge to total stellar mass ratio (0.22-0.85), while being
limited to M_*>10^{10.5} M_sun. The SWELLS sample is thus well-suited for
exploring the relationship between dark and luminous matter in a broad range of
galaxies. We find that the deflector galaxies obey the same size-mass relation
as that of a comparison sample of elongated non-lens galaxies selected from the
SDSS survey. We conclude that the SWELLS sample is consistent with being
representative of the overall population of high-mass high-inclination disky
galaxies.Comment: 21 pages, 6 figures, MNRAS, in pres
Inductive Linear-Position Sensor/Limit-Sensor Units
A new sensor provides an absolute position measurement. A schematic view of a motorized linear-translation stage that contains, at each end, an electronic unit that functions as both (1) a non-contact sensor that measures the absolute position of the stage and (2) a non-contact equivalent of a limit switch that is tripped when the stage reaches the nominal limit position. The need for such an absolute linear position-sensor/limit-sensor unit arises in the case of a linear-translation stage that is part of a larger system in which the actual stopping position of the stage (relative to the nominal limit position) must be known. Because inertia inevitably causes the stage to run somewhat past the nominal limit position, tripping of a standard limit switch or other limit sensor does not provide the required indication of the actual stopping position. This innovative sensor unit operates on an electromagnetic-induction principle similar to that of linear variable differential transformers (LVDTs
Determining the Locations of Dust Sources in FeLoBAL Quasars
We conduct a spectroscopic search of quasars observed by the Sloan Digital
Sky Survey (SDSS) with broad absorption line (BAL) troughs due to Mg II and
troughs due to Fe II that simultaneously exhibit strong Balmer narrow emission
lines (NELs). We find that in a redshift range of 0.4 less than or equal to z
less than or equal to 0.9 approximately 23 of the 70 Mg II BALs and 4 of a
subset of 15 Fe II BALs exhibit strong Balmer emission. We also find
significant fractions of Mg II BALs (approximately 23%) and those Mg II BALs
with Fe II troughs (approximately 27%) have strong continuum reddening, E(B -
V) greater than or equal to 0.1. From measurements of the Balmer decrement in
three objects, we find similarly significant reddening of the NEL region in
three of the four objects; the NELs in the fourth object are not measurable. We
also include one object in this study not taken from the SDSS sample that shows
Fe II absorption and strong narrow emission, but due to measurement uncertainty
and low continuum reddening the comparison is consistent but inconclusive. We
find a trend in both the Mg II and Fe II BAL samples between the NEL reddening
and continuum reddening. Because the narrow line reddening is consistent with
the continuum reddening in every object in the two SDSS samples, it suggests
that the reddening sources in these objects likely exist at larger radial
distances than the narrow line regions from the central nucleus.Comment: 40 manuscript pages, accepted in ApJ (July
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