6,943 research outputs found
Comments on "Wall-plug (AC) power consumption of a very high energy e+/e- storage ring collider" by Marc Ross
The paper arXiv:1308.0735 questions some of the technical assumptions made by
the TLEP Steering Group when estimating in arXiv:1305.6498 the power
requirement for the very high energy e+e- storage ring collider TLEP. We show
that our assumptions are based solidly on CERN experience with LEP and the LHC,
as well accelerators elsewhere, and confirm our earlier baseline estimate of
the TLEP power consumption.Comment: 6 page
Experimental study of the uptake of water by soybean roots
The water extraction from soil by plant roots was treated by assuming that such extraction could be represented as a continuously distributed sink (negative source) function. Preliminary results with soybeans grown in soil columns showed that a small part of the root system could extract most of the water used in transpiration. Root density as measured by root length per unit volume of soil was not directly correlated with water uptake. Both the hydraulic conductivity of the soil and root density played a major role in determining the rate of extraction of water at a given depth in the soil. Water uptake per unit root length ranged up to about 0.5 cm3/cm of root/day. This kind of data gives more insight into the conditions at the root-soil interface. The experimental work in this project was developed from a numerical analysis which was supported by an earlier OWRR project (Project No. 65-O3G), and is an example of a basic approach to the study of the interaction of the plant with its environment in which the available degree of understanding of the water flow process in soil is brought to bear upon the plant-soil interaction. The importance of evapotranspiration is well known in the hydrologic cycle. The experimental work described in this report makes a further contribution toward our understanding of this process.U.S. Geological SurveyU.S. Department of the InteriorOpe
Observation of coasting beam at the HERA Proton--Ring
We present data collected with the HERA-B wire target which prove the
existence of coasting beam at the HERA proton storage ring. The coasting beam
is inherently produced by the proton machine operation and is not dominated by
target effects.Comment: 17 pages (Latex), 12 figures (Enc. Postscript
Planning the Future of U.S. Particle Physics (Snowmass 2013): Chapter 6: Accelerator Capabilities
These reports present the results of the 2013 Community Summer Study of the
APS Division of Particles and Fields ("Snowmass 2013") on the future program of
particle physics in the U.S. Chapter 6, on Accelerator Capabilities, discusses
the future progress of accelerator technology, including issues for high-energy
hadron and lepton colliders, high-intensity beams, electron-ion colliders, and
necessary R&D for future accelerator technologies.Comment: 26 page
Prospects for the Search for a Standard Model Higgs Boson in ATLAS using Vector Boson Fusion
The potential for the discovery of a Standard Model Higgs boson in the mass
range m_H < 2 m_Z in the vector boson fusion mode has been studied for the
ATLAS experiment at the LHC. The characteristic signatures of additional jets
in the forward regions of the detector and of low jet activity in the central
region allow for an efficient background rejection. Analyses for the H -> WW
and H -> tau tau decay modes have been performed using a realistic simulation
of the expected detector performance. The results obtained demonstrate the
large discovery potential in the H -> WW decay channel and the sensitivity to
Higgs boson decays into tau-pairs in the low-mass region around 120 GeV.Comment: 20 pages, 13 ps figures, uses EPJ style fil
A High Luminosity e+e- Collider to study the Higgs Boson
A strong candidate for the Standard Model Scalar boson, H(126), has been
discovered by the Large Hadron Collider (LHC) experiments. In order to study
this fundamental particle with unprecedented precision, and to perform
precision tests of the closure of the Standard Model, we investigate the
possibilities offered by An e+e- storage ring collider. We use a design
inspired by the B-factories, taking into account the performance achieved at
LEP2, and imposing a synchrotron radiation power limit of 100 MW. At the most
relevant centre-of-mass energy of 240 GeV, near-constant luminosities of 10^34
cm^{-2}s^{-1} are possible in up to four collision points for a ring of 27km
circumference. The achievable luminosity increases with the bending radius, and
for 80km circumference, a luminosity of 5 10^34 cm^{-2}s^{-1} in four collision
points appears feasible. Beamstrahlung becomes relevant at these high
luminosities, leading to a design requirement of large momentum acceptance both
in the accelerating system and in the optics. The larger machine could reach
the top quark threshold, would yield luminosities per interaction point of
10^36 cm^{-2}s^{-1} at the Z pole (91 GeV) and 2 10^35 cm^{-2}s^{-1} at the W
pair production threshold (80 GeV per beam). The energy spread is reduced in
the larger ring with respect to what is was at LEP, giving confidence that beam
polarization for energy calibration purposes should be available up to the W
pair threshold. The capabilities in term of physics performance are outlined.Comment: Submitted to the European Strategy Preparatory Group 01-04-2013 new
version as re-submitted to PRSTA
Machine Learning Analyses of Highly-Multiplexed Immunofluorescence Identifies Distinct Tumor and Stromal Cell Populations in Primary Pancreatic Tumors
BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a formidable challenge for patients and clinicians.
OBJECTIVE: To analyze the distribution of 31 different markers in tumor and stromal portions of the tumor microenvironment (TME) and identify immune cell populations to better understand how neoplastic, non-malignant structural, and immune cells, diversify the TME and influence PDAC progression.
METHODS: Whole slide imaging (WSI) and cyclic multiplexed-immunofluorescence (MxIF) was used to collect 31 different markers over the course of nine distinctive imaging series of human PDAC samples. Image registration and machine learning algorithms were developed to largely automate an imaging analysis pipeline identifying distinct cell types in the TME.
RESULTS: A random forest algorithm accurately predicted tumor and stromal-rich areas with 87% accuracy using 31 markers and 77% accuracy using only five markers. Top tumor-predictive markers guided downstream analyses to identify immune populations effectively invading into the tumor, including dendritic cells, CD4+ T cells, and multiple immunoregulatory subtypes.
CONCLUSIONS: Immunoprofiling of PDAC to identify differential distribution of immune cells in the TME is critical for understanding disease progression, response and/or resistance to treatment, and the development of new treatment strategies
Hierarchical Multimodel Ensemble Estimates of Soil Water Retention with Global Coverage
A correct quantification of mass and energy exchange processes among land
surface and atmosphere requires an accurate description of unsaturated soil
hydraulic properties. Soil pedotransfer functions (PTFs) have been widely used
to predict soil hydraulic parameters. Here, 13 PTFs were grouped according to
input data requirements and evaluated against a well-documented soil database
with global coverage. Weighted ensembles (calibrated by four groups and the
full 13-member set of PTFs) were shown to have improved performance over
individual PTFs in terms of root mean square error and other model selection
criteria. Global maps of soil water retention data from the ensemble models as
well as their uncertainty were provided. These maps demonstrate that five PTF
ensembles tend to have different estimates, especially in middle and high
latitudes in the Northern Hemisphere. Our full 13-member ensemble model
provides more accurate estimates than PTFs that are currently being used in
earth system models
Distinguishing Various Models of the 125 GeV Boson in Vector Boson Fusion
The hint of a new particle around 125 GeV at the LHC through the decay modes
of diphoton and a number of others may point to quite a number of
possibilities. While at the LHC the dominant production mechanism for the Higgs
boson of the standard model and some other extensions is via the gluon fusion
process, the alternative vector boson fusion is more sensitive to electroweak
symmetry breaking through the gauge-Higgs couplings and therefore can be used
to probe for models beyond the standard model. In this work, using the well
known dijet-tagging technique to single out the vector boson fusion mechanism,
we investigate its capability to discriminate a number of models that have been
suggested to give an enhanced inclusive diphoton production rate, including the
standard model Higgs boson, fermiophobic Higgs boson, Randall-Sundrum radion,
inert-Higgs-doublet model, two-Higgs-doublet model, and the MSSM. The rates in
vector-boson fusion can give more information of the underlying models to help
distinguishing among the models.Comment: 31 pages, 3 figures; in this version some wordings are change
Simplified Multistep Outflow Method to Estimate Unsaturated Hydraulic Functions for Coarse-Textured Soils
Although the multistep outfl ow (MSO) method is well suited for the estimation of soil hydraulic properties by
inverse solution techniques, this method has not been widely adopted because it requires advanced instrumentation
and is time consuming. Th e objective of this study was to develop a modifi ed version of the multistep outfl ow
technique that largely simplifi es laboratory procedures and reduces costs and time. Th e numerical inversion
procedures require applying user-friendly HYDRUS soft ware to estimate fi tting parameters for soil water retention
and unsaturated hydraulic conductivity curves. Whereas values of saturated water content and saturated hydraulic
conductivity must be measured independently, the remaining functional parameters are estimated using an inverse
solution of a transient drainage experiment using multiple suction steps and a hanging water column, with drainage
outfl ows measured during drainage. A comparison test showed that the simplifi ed experiment without tensiometric
measurements provided suffi cient information in the parameter identifi cation compared with a traditional pressure
outfl ow experiment with tensiometric measurements for an Oso Flaco sand and a loamy sand fi eld soil in the
suction range of 0 to 17 kPa
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