382 research outputs found
Characterization of Vitis vinifera cultivars by random amplified polymorphic DNA markers
Research Not
Kinematics of the Local Universe XIV. Measurements from the 21 cm line and the HI mass function from a homogeneous catalog gathered with the Nancay radio telescope
Aims. This paper presents 828 new 21 cm neutral hydrogen line measurements carried out with the FORT receiver of the meridian transit Nancay radio telescope (NRT) in the years 2000-2007.Methods. This observational program was part of a larger project aimed at collecting an exhaustive and magnitude-complete HI extragalactic catalog for Tully-Fisher applications. Through five massive data releases, the KLUN series has collected a homogeneous sample of 4876 HI-spectra of spiral galaxies, complete down to a flux of 5 Jy km s(-1) and with declination delta > -40 degreesResults. We publish here the last release of the KLUN HI observational program, corresponding to the faint end of the survey, with HI masses ranging from 5 x 10(8) to 5 x 10(10) solar masses. The size of this final sample is comparable to the catalogs based on the Arecibo and Parkes radio telescope campaigns, and it allows general HI mass distribution studies from a set of homogeneous radio measurements
Dissolution Behaviour of Alkali-activated Fe-rich Non-ferrous Metallurgy Slag in Acetic Acid
The application of Fe-rich non-ferrous metallurgy slag (NFS, within a FeOx-SiO2-Al2O3-CaO system) in alkali-activated materials requires detailed information on the durability performance. The present study investigates the durability of alkali activated NFS (AA-NFS) exposed to acetic acid to simulate the attack of a concrete by organic acids present in animal manure or sewage systems. The dissolution behavior of NFS and alkali-activated NFS (AA-NFS) was assessed by immersing NFS and AA-NFS in a 3 wt. % acetic acid solution at a liquid to solid weight ratio of 1000. The dissolved ions in the acetic solution from NFS and AA-NFS were measured at different time intervals over 7 days. Through the comparison of NFS with AA-NFS, the dissolution behavior of unreacted slag and binder in AA-NFS could be evaluated separately, considering a calculated amount of 47.7 wt.% of unreacted slag was present in the AA-NFS. The results demonstrated that the binder dissolves slightly faster than slag in the first 4 hours. Over half of the dissolution rate of the Ca, Fe and Al in AA-NFS was due to binder. While for Si, 41% total dissolution rate in AA-NFS was from binder and the other 59% was from unreacted slag. After 7 days however, the dissolved fraction of slag was higher than binder. About 90% Ca, 79% Fe and 71% Al in slag was ended up in the acetic acid solution, which is higher than that in binder (74%, 62% and 56%, respectively). A significantly higher difference was found for the total dissolved fraction of Si in slag (86%) compared to that in binder (43%). The highly connected silicate network in the binder remains largely intact as silica gel, while due to the low connectivity of the silicate species in the slag the silicate dissolves after the other elements have left the structure. Overall these results suggest that Ca has the lowest dissolution resistance in binder, followed by Fe, Al and Si
Salford postgraduate annual research conference (SPARC) 2012 proceedings
These proceedings bring together a selection of papers from the 2012 Salford Postgraduate Annual Research Conference (SPARC). They reflect the breadth and diversity of research interests showcased at the conference, at which over 130 researchers from Salford, the North West and other UK universities presented their work. 21 papers are collated here from the humanities, arts, social sciences, health, engineering, environment and life sciences, built environment and business
Transport Measurements on Nano-engineered Two Dimensional Superconducting Wire Networks
Superconducting triangular Nb wire networks with high normal-state resistance
are fabricated by using a negative tone hydrogen silsesquioxane (HSQ) resist.
Robust magnetoresistance oscillations are observed up to high magnetic fields
and maintained at low temperatures, due to the eective reduction of wire
dimensions. Well-defined dips appear at integral and rational values (1/2, 1/3,
1/4) of the reduced flux f = Phi/Phi_0, which is the first observation in the
triangular wire networks. These results are well consistent with theoretical
calculations for the reduced critical temperature as a function of f.Comment: 4 pages, 3 figure
Switching and growth for microbial populations in catastrophic responsive environments
Phase variation, or stochastic switching between alternative states of gene
expression, is common among microbes, and may be important in coping with
changing environments. We use a theoretical model to assess whether such
switching is a good strategy for growth in environments with occasional
catastrophic events. We find that switching can be advantageous, but only when
the environment is responsive to the microbial population. In our model,
microbes switch randomly between two phenotypic states, with different growth
rates. The environment undergoes sudden "catastrophes", the probability of
which depends on the composition of the population. We derive a simple
analytical result for the population growth rate. For a responsive environment,
two alternative strategies emerge. In the "no switching" strategy, the
population maximises its instantaneous growth rate, regardless of catastrophes.
In the "switching" strategy, the microbial switching rate is tuned to minimise
the environmental response. Which of these strategies is most favourable
depends on the parameters of the model. Previous studies have shown that
microbial switching can be favourable when the environment changes in an
unresponsive fashion between several states. Here, we demonstrate an
alternative role for phase variation in allowing microbes to maximise their
growth in catastrophic responsive environments.Comment: 9 pages, 10 figures; replaced with revised versio
Kinematics of the Local Universe XIII. 21-cm line measurements of 452 galaxies with the Nan\c{c}ay radiotelescope, JHK Tully-Fisher relation and preliminary maps of the peculiar velocity field
This paper presents 452 new 21-cm neutral hydrogen line measurements carried
out with the FORT receiver of the meridian transit Nan\c{c}ay radiotelescope
(NRT) in the period April 2003 -- March 2005. This observational programme is
part of a larger project aiming at collecting an exhaustive and
magnitude-complete HI extragalactic catalogue for Tully-Fisher applications
(the so-called KLUN project, for Kinematics of the Local Universe studies, end
in 2008). The whole on-line HI archive of the NRT contains today reduced
HI-profiles for ~4500 spiral galaxies of declination delta > -40°
(http://klun.obs-nancay.fr). As an example of application, we use direct
Tully-Fisher relation in three (JHK) bands in deriving distances to a large
catalog of 3126 spiral galaxies distributed through the whole sky and sampling
well the radial velocity range between 0 and 8000 km/s. Thanks to an iterative
method accounting for selection bias and smoothing effects, we show as a
preliminary output a detailed and original map of the velocity field in the
Local Universe
The empirical basis for modelling glacial erosion rates
Glaciers are highly effective agents of erosion that have profoundly shaped Earth’s surface, but there is uncertainty about how glacial erosion should be parameterised in landscape evolution models. Glacial erosion rate is usually modelled as a function of glacier sliding velocity, but the empirical basis for this relationship is weak. In turn, climate is assumed to control sliding velocity and hence erosion, but this too lacks empirical scrutiny. Here, we present statistically robust relationships between erosion rates, sliding velocities, and climate from a global compilation of 38 glaciers. We show that sliding is positively and significantly correlated with erosion, and derive a relationship for use in erosion models. Our dataset further demonstrates that the most rapid erosion is achieved at temperate glaciers with high mean annual precipitation, which serve to promote rapid sliding. Precipitation has received little attention in glacial erosion studies, but our data illustrate its importance
Surface energy budget and thermal inertia at Gale Crater: Calculations from ground‐based measurements
The analysis of the surface energy budget (SEB) yields insights into soil‐atmosphere interactions and local climates, while the analysis of the thermal inertia ( I ) of shallow subsurfaces provides context for evaluating geological features. Mars orbital data have been used to determine thermal inertias at horizontal scales of ~10 4 m 2 to ~10 7 m 2 . Here we use measurements of ground temperature and atmospheric variables by Curiosity to calculate thermal inertias at Gale Crater at horizontal scales of ~10 2 m 2 . We analyze three sols representing distinct environmental conditions and soil properties, sol 82 at Rocknest (RCK), sol 112 at Point Lake (PL), and sol 139 at Yellowknife Bay (YKB). Our results indicate that the largest thermal inertia I = 452 J m −2 K −1 s −1/2 (SI units used throughout this article) is found at YKB followed by PL with I = 306 and RCK with I = 295. These values are consistent with the expected thermal inertias for the types of terrain imaged by Mastcam and with previous satellite estimations at Gale Crater. We also calculate the SEB using data from measurements by Curiosity's Rover Environmental Monitoring Station and dust opacity values derived from measurements by Mastcam. The knowledge of the SEB and thermal inertia has the potential to enhance our understanding of the climate, the geology, and the habitability of Mars. Key Points We calculate the thermal inertia and surface energy budget at Gale Crater We use MSL REMS measurements for our calculationsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108664/1/jgre20287.pd
- …