7,268 research outputs found
InSb charge coupled infrared imaging device: The 20 element linear imager
The design and fabrication of the 8585 InSb charge coupled infrared imaging device (CCIRID) chip are reported. The InSb material characteristics are described along with mask and process modifications. Test results for the 2- and 20-element CCIRID's are discussed, including gate oxide characteristics, charge transfer efficiency, optical mode of operation, and development of the surface potential diagram
A study of the phase transition in the usual statistical model for nuclear multifragmentation
We use a simplified model which is based on the same physics as inherent in
most statistical models for nuclear multifragmentation. The simplified model
allows exact calculations for thermodynamic properties of systems of large
number of particles. This enables us to study a phase transition in the model.
A first order phase transition can be tracked down. There are significant
differences between this phase transition and some other well-known cases
Technical Reference: Using Lightning Location in the Wildland Fire Assessment System
Location of the ground position of lightning discharges has been possible for several years. A technique for using ignition probability calculations together with lightning location data results in maps that are useful to fire managers in making decisions on timescales from historical to real-time. These maps, part of the Wildland Fire Assessment System, will aid fire managers in assessing the potential that lightning will result in reportable fires. The maps are generated using ignition probability based on duff depth, fuel moisture, and fuel type. To match fire potential classes, ignition probabilities are classified into ignition potential classes of low. medium, high, very high, and extreme. Possible benefits are savings in time, fire suppression costs, and perhaps even lives
Satellite data relay and platform locating in oceanography. Report of the In Situ Ocean Science Working Group
The present and future use of satellites to locate offshore platforms and relay data from in situ sensors to shore was examined. A system of the ARGOS type will satisfy the increasing demand for oceanographic information through data relay and platform location. The improved ship navigation provided by the Global Positioning System (GPS) will allow direct observation of currents from underway ships. Ocean systems are described and demand estimates on satellite systems are determined. The capabilities of the ARGOS system is assessed, including anticipated demand in the next decade
Conical scan impact study. Volume 2: Small local user data processing facility
The impact of a conical scan versus a linear scan multispectral scanner (MSS) instrument on a small local-user data processing facility was studied. User data requirements were examined to determine the unique system rquirements for a low cost ground system (LCGS) compatible with the Earth Observatory Satellite (EOS) system. Candidate concepts were defined for the LCGS and preliminary designs were developed for selected concepts. The impact of a conical scan MSS versus a linear scan MSS was evaluated for the selected concepts. It was concluded that there are valid user requirements for the LCGS and, as a result of these requirements, the impact of the conical scanner is minimal, although some new hardware development for the LCGS is necessary to handle conical scan data
Rare isotope production in statistical multifragmentation
Producing rare isotopes through statistical multifragmentation is
investigated using the Mekjian method for exact solutions of the canonical
ensemble. Both the initial fragmentation and the the sequential decay are
modeled in such a way as to avoid Monte Carlo and thus provide yields for
arbitrarily scarce fragments. The importance of sequential decay, exact
particle-number conservation and the sensitivities to parameters such as
density and temperature are explored. Recent measurements of isotope ratios
from the fragmentation of different Sn isotopes are interpreted within this
picture.Comment: 10 eps figure
Treatments for pregestational chronic conditions during pregnancy: emulating a target trial with a treatment decision design
As a solution to methodologic challenges inherent to estimating causal
effects of exposures in early pregnancy, we suggest emulating a target trial
using a treatment decision design, wherein time zero is centered around
clinical landmarks where treatment decisions may occur, such as the date of
preconception counseling or prenatal care initiation. These ideas are
illustrated via protocols for two target trials in large administrative
databases, antidepressant use for pre-existing depressive disorder and
antihypertensive medication use for mild-to-moderate chronic hypertension.
Careful consideration of these issues is critical to the identification of the
causal effects of early-pregnancy pharmacotherapies on pregnancy outcomes
Herd-level risk factors associated with the presence of Phage type 21/28 E. coli O157 on Scottish cattle farms
<p>Background: E. coli O157 is a bacterial pathogen that is shed by cattle and can cause severe disease in humans. Phage type (PT) 21/28 is a subtype of E. coli O157 that is found across Scotland and is associated with particularly severe human morbidity.</p>
<p>Methods: A cross-sectional survey of Scottish cattle farms was conducted in the period Feb 2002-Feb 2004 to determine the prevalence of E. coli O157 in cattle herds. Data from 88 farms on which E. coli O157 was present were analysed using generalised linear mixed models to identify risk factors for the presence of PT 21/28 specifically.</p>
<p>Results: The analysis identified private water supply, and northerly farm location as risk factors for PT 21/28 presence. There was a significant association between the presence of PT 21/28 and an increased number of E. coli O157 positive pat samples from a farm, and PT 21/28 was significantly associated with larger E. coli O157 counts than non-PT 21/28 E. coli O157.</p>
<p>Conclusion: PT 21/28 has significant risk factors that distinguish it from other phage types of E. coli O157. This finding has implications for the control of E. coli O157 as a whole and suggests that control could be tailored to target the locally dominant PT.</p>
2021-2022 Statewide Utah Angler Survey Report
Continuing an effort that dates to 1967, we collected data through a statewide survey of licensed anglers in an effort to understand their preference and behaviors. Anglers were surveyed across the state of Utah, as well as nonresident anglers who purchased a Utah fishing license. This research was guided by objectives developed by the Division of Wildlife Resources (DWR) as and our research team at the Institute of Outdoor Recreation and Tourism at Utah State University. In the report, we provide statewide statistics and comparisons between the DWRs five management regions. The objectives and key findings are:Objective 1. Define the characteristics of Utah anglersObjective 2. Produce a snapshot of angling in Utah over a 12-month periodObjective 3. Identify what motivates Utah anglersObjective 4. Identify what fish species anglers expected to catch, caught, and prefer to catchObjective 5. Gauge anglers’ perceptions and knowledge of native and nonnative fish species in UtahObjective 6. Explore Utah anglers’ perceptions of, and experiences with, crowdingObjective 7. Identify potential areas where managers can create or promote opportunities for Utah anglers to combine recreational activities to enhance the angling experienceThe report provides tables and figures and explanations pertaining to each of the research objectives outlined above. In addition, statewide and regional statistics are provided to showcase the unique trends associated with Utah anglers and angling resources in Utah
Studies in the statistical and thermal properties of hadronic matter under some extreme conditions
The thermal and statistical properties of hadronic matter under some extreme
conditions are investigated using an exactly solvable canonical ensemble model.
A unified model describing both the fragmentation of nuclei and the thermal
properties of hadronic matter is developed. Simple expressions are obtained for
quantities such as the hadronic equation of state, specific heat,
compressibility, entropy, and excitation energy as a function of temperature
and density. These expressions encompass the fermionic aspect of nucleons, such
as degeneracy pressure and Fermi energy at low temperatures and the ideal gas
laws at high temperatures and low density. Expressions are developed which
connect these two extremes with behavior that resembles an ideal Bose gas with
its associated Bose condensation. In the thermodynamic limit, an infinite
cluster exists below a certain critical condition in a manner similar to the
sudden appearance of the infinite cluster in percolation theory. The importance
of multiplicity fluctuations is discussed and some recent data from the EOS
collaboration on critical point behavior of nuclei can be accounted for using
simple expressions obtained from the model.Comment: 22 pages, revtex, includes 6 figures, submitted to Phys. Rev.
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