3,841 research outputs found
Microwave spectroscopy of the Mars atmosphere
A study of the use of millimeter-wavelength spectral transitions to investigate the atmosphere of Mars is presented. In the model experiments investigated it is assumed that a spectrometer in the frequency range from 100 to 260 GHz looks into a modest-sized telescope of from 30 to 50 cm aperture from a near-Mars orbit. The molecules H2O, CO, O2, O3, and H2O2 all have intense spectral lines in the Mars atmosphere in this frequency range and in addition are all very important in understanding the water cycle, the photochemistry, and the circularization in that atmosphere. It is shown that the altitude and the zonal distribution of H2O can be mapped even in atmospheric columns as dry as 0.25 precipital μm. Ozone can be mapped over the entire planet, independent of solar-lighting conditions, dust loading, or clouds in the atmosphere, because millimeter waves are insensitive to any particles that can be suspended in the Mars atmosphere. Because the signal-receiving techniques use superheterodyne devices and narrow spectral lines, zonal and meridional winds can be measured at altitudes above 10 km with a precision approaching approximately 3 m/s by the use of Doppler shifts. Temperature–pressure profiles can be measured to altitudes of 100 km by the use of CO lines in the limb-sounding mode
Can’t See the Wood for the Trees: The Returns to Farm Forestry in Ireland
working paperThe period 2007-2009 witnessed considerable variability in the price of outputs such
as milk and cereals and this was compounded by a high degree of volatility in the
price of inputs such as fertilizer, animal feed and energy. Previously, Irish farms have
used the returns to off-farm employment as well as agricultural support payments
such as the Single Farm Payment (SFP) and the Rural Environmental Protection
Scheme (REPS) to protect their living standards against low and uncertain agricultural
market returns. However, the downturn in the Irish economy has led to a reduction in
the availability of off-farm employment and also the discontinuation of REPS. This
may lead to an increase in afforestation on Irish farms, as forestry offers greater
certainty through the provision of an annual premium in addition to the SFP.
However, the decision to afforest represents a significant long-term investment
decision that should not be entered into without careful economic consideration. The
aim of this paper is to use the Discounted Cash Flow (DCF) analysis method to
calculate the returns to forestry under alternative opportunity costs associated with
conventional agricultural activities being superseded. The returns to forestry are
calculated using the Forestry Investment Value Estimator (FIVE). These returns were
then incorporated in the DCF model along with the returns to five conventional
agricultural enterprises, which would potentially be superseded by forestry. This
approach allows for the calculation of the Net Present Value (NPV) of three forestry
scenarios
Critical properties of the unconventional spin-Peierls system TiOBr
We have performed detailed x-ray scattering measurements on single crystals
of the spin-Peierls compound TiOBr in order to study the critical properties of
the transition between the incommensurate spin-Peierls state and the
paramagnetic state at Tc2 ~ 48 K. We have determined a value of the critical
exponent beta which is consistent with the conventional 3D universality
classes, in contrast with earlier results reported for TiOBr and TiOCl. Using a
simple power law fit function we demonstrate that the asymptotic critical
regime in TiOBr is quite narrow, and obtain a value of beta_{asy} = 0.32 +/-
0.03 in the asymptotic limit. A power law fit function which includes the first
order correction-to-scaling confluent singularity term can be used to account
for data outside the asymptotic regime, yielding a more robust value of
beta_{avg} = 0.39 +/- 0.05. We observe no evidence of commensurate fluctuations
above Tc1 in TiOBr, unlike its isostructural sister compound TiOCl. In
addition, we find that the incommensurate structure between Tc1 and Tc2 is
shifted in Q-space relative to the commensurate structure below Tc1.Comment: 12 pages, 8 figures. Submitted to Physical Review
A "partitioned leaping" approach for multiscale modeling of chemical reaction dynamics
We present a novel multiscale simulation approach for modeling stochasticity
in chemical reaction networks. The approach seamlessly integrates
exact-stochastic and "leaping" methodologies into a single "partitioned
leaping" algorithmic framework. The technique correctly accounts for stochastic
noise at significantly reduced computational cost, requires the definition of
only three model-independent parameters and is particularly well-suited for
simulating systems containing widely disparate species populations. We present
the theoretical foundations of partitioned leaping, discuss various options for
its practical implementation and demonstrate the utility of the method via
illustrative examples.Comment: v4: 12 pages, 5 figures, final accepted version. Error found and
fixed in Appendi
The global addiction academy project: a global phenomenon - requiring a global solution - from a global community
The emergence of different and effective modes of e-communications has rapidly expanded possibilities for more extensive dialogue, collaboration and learning. For professionals and those working with addiction issues and support services, these offer increased opportunities to break down significant barriers to integrating issues of addiction into the care sector workforce and to ensure that the workforce can respond more appropriately and confidently and to access a range of up-to-date resources as well as to share best practice and expertise. Our international collaboration to develop a Global Classroom which started at the beginning of 2014 seeks to provide an innovative online platform for stimulating learning among people of different disciplines and interests on addictions. We aim to bring people together from diverse cultural communities to engage in dialogue, debate and to share ideas on addiction beyond their own peers, regions or country and to meet a range of learning needs within this structure which is inclusive and developmental. This symposium will share the outcomes of our early developments in the first year of developing a global addiction academy project, the challenges and possibilities particularly focusing on the impact of such methodology on achieving wider engagement on a global public health issue and enhancing inter-professional learning
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