14 research outputs found
LENDA, a Low Energy Neutron Detector Array for experiments with radioactive beams in inverse kinematics
The Low Energy Neutron Detector Array (LENDA) is a neutron time-of-flight
(TOF) spectrometer developed at the National Superconducting Cyclotron Lab-
oratory (NSCL) for use in inverse kinematics experiments with rare isotope
beams. Its design has been motivated by the need to study the spin-isospin
response of unstable nuclei using (p, n) charge-exchange reactions at
intermediate energies (> 100 MeV/u). It can be used, however, for any reaction
study that involves emission of low energy neutrons (150 keV - 10 MeV). The
array consists of 24 plastic scintillator bars and is capable of registering
the recoiling neutron energy and angle with high detection efficiency. The
neutron energy is determined by the time-of-flight technique, while the
position of interaction is deduced using the timing and energy information from
the two photomultipliers of each bar. A simple test setup utilizing radioactive
sources has been used to characterize the array. Results of test measurements
are compared with simulations. A neutron energy threshold of < 150 keV, an
intrinsic time (position) resolution of \sim 400 ps (\sim 6 cm) and an
efficiency > 20 % for neutrons below 4 MeV have been obtained.Comment: Version accepted for publication in Nucl. Instr. Methods A. Revised
text, 2 new figures added (one in section 4 and one in section 7
Giving and receiving in Paul's epistles Greco-Roman social conventions in Philippians and selected Pauline texts
SIGLEAvailable from British Library Document Supply Centre- DSC:DX186779 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Hippocampal Aβ expression, but not phosphorylated tau, predicts cognitive deficits following repeated peripheral poly I:C administration
The Sr isotope composition of the world ocean, marginal and inland seas: Implications for the Sr isotope stratigraphy
A Comparison of Dipterans from Ten Created and Ten Natural Wetlands
This study compares densities of common larval dipterans collected from areas dominated by Pontederia cordata in 10 natural and 10 created freshwater herbaceous wetlands in central Florida. At each wetland, 7 core. samples were collected from each of 5 stations during summer 1993. In addition, stem densities, vegetation areal coverage, pH, dissolved oxygen, water temperature, water depth, conductivity, sediment quality, and leaf litter were measured at 3 locations near each of the 5 stations in each wetland. Of the 57 dipteran taxa collected, 20 occurred with sufficient abundance to justify statistical comparison. Despite a large sampling effort, there were no significant differences in densities of 20 commonly occurring taxa found in created and natural wetlands after considering the effect of multiple univariate tests. Comparison of environmental variables showed significant differences in stem densities for vegetation other than P. cordata,, pH, conductivity, and sediment quality. Canonical correspondence analysis, used to relate environmental and biological variables, suggests that pH, conductivity, and sediment quality are only weakly related to dipteran community structure. Despite differences in environmental conditions, there is no convincing evidence of differences in natural and created wetland dipteran communities