903 research outputs found
Research in Progress: On-Farm Storage of Ethanol Co-Products
In the past four years, five new dry-mill ethanol plants have been constructed in the northwest Iowa, and another one is under construction. These six mills will process 82 million bushels of corn to produce 217 million gallons of ethanol and almost 700,000 tons of co-products. In the production of one million gallons of ethanol yearly, almost 9 tons of co-product are produced daily. Consequently, the daily marketing of ethanol co-products is important.
Livestock producers, who take delivery of the coproducts on a regular basis, are using various storage methods and management schemes. Unfortunately, research in the storage of dry-mill ethanol co-products on-farm is in its infancy, and there are many questions yet to be addressed. The Department of Animal Science at ISU began this on-farm research to help determine nutritional and storage losses of ethanol co-products stored on-farm. This research involved four on-farm storage trials
The 21-SPONGE HI Absorption Survey I: Techniques and Initial Results
We present methods and results from "21-cm Spectral Line Observations of
Neutral Gas with the EVLA" (21-SPONGE), a large survey for Galactic neutral
hydrogen (HI) absorption with the Karl G. Jansky Very Large Array (VLA). With
the upgraded capabilities of the VLA, we reach median root-mean-square (RMS)
noise in optical depth of per
channel for the 31 sources presented here. Upon
completion, 21-SPONGE will be the largest HI absorption survey with this high
sensitivity. We discuss the observations and data reduction strategies, as well
as line fitting techniques. We prove that the VLA bandpass is stable enough to
detect broad, shallow lines associated with warm HI, and show that bandpass
observations can be combined in time to reduce spectral noise. In combination
with matching HI emission profiles from the Arecibo Observatory (
angular resolution), we estimate excitation (or spin) temperatures ()
and column densities for Gaussian components fitted to sightlines along which
we detect HI absorption (30/31). We measure temperatures up to for individual lines, showing that we can probe the
thermally unstable interstellar medium (ISM) directly. However, we detect fewer
of these thermally unstable components than expected from previous
observational studies. We probe a wide range in column density between
and for individual HI clouds. In addition,
we reproduce the trend between cold gas fraction and average found by
synthetic observations of a hydrodynamic ISM simulation by Kim et al. (2014).
Finally, we investigate methods for estimating HI and discuss their
biases.Comment: Accepted for publication in ApJ; 24 pages, 14 figure
A GBT Survey of the HALOGAS Galaxies and Their Environments I: Revealing the full extent of HI around NGC891, NGC925, NGC4414 & NGC4565
We present initial results from a deep neutral hydrogen (HI) survey of the
HALOGAS galaxy sample, which includes the spiral galaxies NGC891, NGC925,
NGC4414, and NGC4565, performed with the Robert C. Byrd Green Bank Telescope
(GBT). The resulting observations cover at least four deg around these
galaxies with an average 5 detection limit of 1.210
cm over a velocity range of 20 km s and angular scale of 9.1.
In addition to detecting the same total flux as the GBT data, the spatial
distribution of the GBT and original Westerbork Synthesis Radio Telescope
(WSRT) data match well at equal spatial resolutions. The HI mass fraction below
HI column densities of 10 cm is, on average, 2\%. We discuss the
possible origins of low column density HI of nearby spiral galaxies. The
absence of a considerable amount of newly detected HI by the GBT indicates
these galaxies do not have significant extended diffuse HI structures, and
suggests future surveys planned with the SKA and its precursors must go
\textit{at least} as deep as 10 cm in column density to
significantly increase the probability of detecting HI associated with the
cosmic web and/or cold mode accretion.Comment: Accepted for publication in The Astrophysical Journal; 28 pages, 15
figure
Analysing Lyapunov spectra of chaotic dynamical systems
It is shown that the asymptotic spectra of finite-time Lyapunov exponents of
a variety of fully chaotic dynamical systems can be understood in terms of a
statistical analysis. Using random matrix theory we derive numerical and in
particular analytical results which provide insights into the overall behaviour
of the Lyapunov exponents particularly for strange attractors. The
corresponding distributions for the unstable periodic orbits are investigated
for comparison.Comment: 4 pages, 4 figure
The GALFA-HI Compact Cloud Catalog
We present a catalog of 1964 isolated, compact neutral hydrogen clouds from
the Galactic Arecibo L-Band Feed Array Survey Data Release One (GALFA-HI DR1).
The clouds were identified by a custom machine-vision algorithm utilizing
Difference of Gaussian kernels to search for clouds smaller than 20'. The
clouds have velocities typically between |VLSR| = 20-400 km/s, linewidths of
2.5-35 km/s, and column densities ranging from 1 - 35 x 10^18 cm^-2. The
distances to the clouds in this catalog may cover several orders of magnitude,
so the masses may range from less than a Solar mass for clouds within the
Galactic disc, to greater than 10^4 Solar Masses for HVCs at the tip of the
Magellanic Stream. To search for trends, we separate the catalog into five
populations based on position, velocity, and linewidth: high velocity clouds
(HVCs); galaxy candidates; cold low velocity clouds (LVCs); warm, low
positive-velocity clouds in the third Galactic Quadrant; and the remaining warm
LVCs. The observed HVCs are found to be associated with previously-identified
HVC complexes. We do not observe a large population of isolated clouds at high
velocities as some models predict. We see evidence for distinct histories at
low velocities in detecting populations of clouds corotating with the Galactic
disc and a set of clouds that is not corotating.Comment: 34 Pages, 9 Figures, published in ApJ (2012, ApJ, 758, 44), this
version has the corrected fluxes and corresponding flux histogram and masse
The Ethnic 'Other' in Ukrainian History Textbooks: The Case of Russia and the Russians
This paper examines portrayals of Russia and the Russians in two generations of Ukrainian history textbooks. It observes that the textbooks are highly condemning of Ukraine's main ethnic other in the guise of foreign ruler: the tsarist authorities and the Soviet regime are always attributed dubious and malicious intentions even if there is appreciation for some of their policies. By contrast, the books, certainly those of the second generation, refrain from presenting highly biased accounts of the ethnic other as a national group (i.e. Russians). Instances where negative judgements do fall onto Russians are counterbalanced by excerpts criticizing ethnic Ukrainians or highlighting conflicting interests within the Ukrainian ethnic group. The negative appraisal of the ethnic other as foreign ruler is clearly instrumental for the nation-building project as it sustains a discourse legitimating the existence of Ukraine as independent state. However, recent trends in history education, the paper concludes, suggest that the importance of nurturing patriotism as a national policy objective is diminishing
Physico-chemical foundations underpinning microarray and next-generation sequencing experiments
Hybridization of nucleic acids on solid surfaces is a key process involved in high-throughput technologies such as microarrays and, in some cases, next-generation sequencing (NGS). A physical understanding of the hybridization process helps to determine the accuracy of these technologies. The goal of a widespread research program is to develop reliable transformations between the raw signals reported by the technologies and individual molecular concentrations from an ensemble of nucleic acids. This research has inputs from many areas, from bioinformatics and biostatistics, to theoretical and experimental biochemistry and biophysics, to computer simulations. A group of leading researchers met in Ploen Germany in 2011 to discuss present knowledge and limitations of our physico-chemical understanding of high-throughput nucleic acid technologies. This meeting inspired us to write this summary, which provides an overview of the state-of-the-art approaches based on physico-chemical foundation to modeling of the nucleic acids hybridization process on solid surfaces. In addition, practical application of current knowledge is emphasized
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