825 research outputs found
Farm, Rural Economy, and Policy Implications of Sustainable Agriculture in South Dakota
South Dakota State University (SDSU) has been conducting research since the mid- 1980s on what has come to be called sustainable agriculture. We have been examining farming systems in which producers adopt management-intensive, holistic system orientations in planning their farms. Such farm managers generally view themselves as allies with nature, rather than as conquerors of nature. In addition to economic survivability, these farmers tend to give high priority to (1) being good stewards of the soil, (2) reducing pollution of ground and surface water, (3) raising chemical residue free, high quality products, and (4) reducing possible harmful effects of farm chemicals on their families\u27 health
Agronomic, Economic and Ecological Relationships in Alternative (Organic), Coventional, and Reduced-till Farming Systems
The objectives of the experiment station trials were to: • Measure yields in alternative, conventional and reduced-till farming systems. • Compare whole-farm economic performance. • Measure whole-farm productivity of the systems. • Determine influence of farming system on soil nutrient relationships, soil temperatures, soil water content, bulk density, residue cover, and snow catch. • Compare populations of plant feeding, predaceous, and microbial feeding nematodes. • Determine populations of fungi and bacteria, and measure mycorrhizal associations and soil fungistatic properties. • Determine effect of farming systems on earthworm populations. • Determine weed species present and densities. • Measure beneficial and harmful arthropod populations and measure insect damage. • Compare the relative sustainability of the various systems. This list of objectives represents various interests of the researchers and also reflects an attempt to obtain a holistic view of the processes that constitute a farming system
First atom lifetime and scattering length measurements
The results of a search for hydrogen-like atoms consisting of
mesons are presented. Evidence for atom production
by 24 GeV/c protons from CERN PS interacting with a nickel target has been seen
in terms of characteristic pairs from their breakup in the same target
() and from Coulomb final state interaction (). Using
these results the analysis yields a first value for the atom lifetime
of fs and a first model-independent measurement of
the S-wave isospin-odd scattering length
( for isospin ).Comment: 14 pages, 8 figure
Pion and proton showers in the CALICE scintillator-steel analogue hadron calorimeter
Showers produced by positive hadrons in the highly granular CALICE
scintillator-steel analogue hadron calorimeter were studied. The experimental
data were collected at CERN and FNAL for single particles with initial momenta
from 10 to 80 GeV/c. The calorimeter response and resolution and spatial
characteristics of shower development for proton- and pion-induced showers for
test beam data and simulations using Geant4 version 9.6 are compared.Comment: 26 pages, 16 figures, JINST style, changes in the author list, typos
corrected, new section added, figures regrouped. Accepted for publication in
JINS
Shower development of particles with momenta from 15 GeV to 150 GeV in the CALICE scintillator-tungsten hadronic calorimeter
We present a study of showers initiated by electrons, pions, kaons, and
protons with momenta from 15 GeV to 150 GeV in the highly granular CALICE
scintillator-tungsten analogue hadronic calorimeter. The data were recorded at
the CERN Super Proton Synchrotron in 2011. The analysis includes measurements
of the calorimeter response to each particle type as well as measurements of
the energy resolution and studies of the longitudinal and radial shower
development for selected particles. The results are compared to Geant4
simulations (version 9.6.p02). In the study of the energy resolution we include
previously published data with beam momenta from 1 GeV to 10 GeV recorded at
the CERN Proton Synchrotron in 2010.Comment: 35 pages, 21 figures, 8 table
Performance of the first prototype of the CALICE scintillator strip electromagnetic calorimeter
A first prototype of a scintillator strip-based electromagnetic calorimeter
was built, consisting of 26 layers of tungsten absorber plates interleaved with
planes of 45x10x3 mm3 plastic scintillator strips. Data were collected using a
positron test beam at DESY with momenta between 1 and 6 GeV/c. The prototype's
performance is presented in terms of the linearity and resolution of the energy
measurement. These results represent an important milestone in the development
of highly granular calorimeters using scintillator strip technology. This
technology is being developed for a future linear collider experiment, aiming
at the precise measurement of jet energies using particle flow techniques
The Time Structure of Hadronic Showers in highly granular Calorimeters with Tungsten and Steel Absorbers
The intrinsic time structure of hadronic showers influences the timing
capability and the required integration time of hadronic calorimeters in
particle physics experiments, and depends on the active medium and on the
absorber of the calorimeter. With the CALICE T3B experiment, a setup of 15
small plastic scintillator tiles read out with Silicon Photomultipliers, the
time structure of showers is measured on a statistical basis with high spatial
and temporal resolution in sampling calorimeters with tungsten and steel
absorbers. The results are compared to GEANT4 (version 9.4 patch 03)
simulations with different hadronic physics models. These comparisons
demonstrate the importance of using high precision treatment of low-energy
neutrons for tungsten absorbers, while an overall good agreement between data
and simulations for all considered models is observed for steel.Comment: 24 pages including author list, 9 figures, published in JINS
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