3,743 research outputs found
Aerospace nickel-cadmium cell separator qualifications program
The present space qualified nylon separator, Pellon 2505 ML, is no longer available for aerospace nickel-cadmium (NiCd) cells. As a result of this anticipated unavailability, a joint Government program between the Air Force Space Division and the Naval Research Laboratory was established. Four cell types were procured with both the old qualified and the new unqualified separators. Acceptance, characterization, and life cycling tests are to be performed at the Naval Weapons Support Center, Crane, Ind. (NWSC/Crane). The scheduling and current status of this program are discussed and the progress of testing and available results are projected
Pentatomidae (Hemiptera: Heteroptera: Pentatomidae) Captured on Purple Prism Traps Deployed for Detection of Emerald Ash Borer (Agrilus planipennis) (Coleoptera: Buprestidae) in Minnesota
The observation of bycatch from insect trapping programs, though often considered bothersome, may hold value for ecological and taxonomic studies. In Minnesota, a large trapping survey consisting of pheromone-baited purple prism traps, has been conducted for early detection of Agrilus planipennis, the emerald ash borer. Stink bugs (Heteroptera: Pentatomidae), which are pests of increasing importance in the North Central U.S., were observed to be captured by these traps. The objective of this study was to use trap bycatch from the A. planipennis traps for further documentation of the abundance and diversity of Pentatomidae in Minnesota. In 2011 and 2012, 4,401 and 5,651 purple prism traps were deployed and checked in Minnesota, respectively. Across both years, a total of 17 species of Pentatomidae were identified from 2 subfamilies, Asopinae and Pentatominae. The most abundant and prevalent species collected were Banasa calva (Say), B. dimidiata (Say), Chinavia hilaris (Say), Euschistus tristigmus luridus Dallas, Menecles insertus (Say), and Podisus maculiventris (Say). The pentatomid community observed on purple prism traps deployed in arboreal habitats differed from pentatomid communities reported in Minnesota crops (i.e., soybean, wheat and corn). Results of this study show that many pentatomid species are captured on purple prism traps and therefore bycatch of these traps could provide valuable information on the pentatomid community. However, purple prism traps should be used in addition to traditional surveillance or scouting methods for pentatomids
Probability distributions of smeared quantum stress tensors
We obtain in closed form the probability distribution for individual
measurements of the stress-energy tensor of two-dimensional conformal field
theory in the vacuum state, smeared in time against a Gaussian test function.
The result is a shifted Gamma distribution with the shift given by the
previously known optimal quantum inequality bound. For small values of the
central charge it is overwhelmingly likely that individual measurements of the
sampled energy density in the vacuum give negative results. For the case of a
single massless scalar field, the probability of finding a negative value is
84%. We also report on computations for four-dimensional massless scalar fields
showing that the probability distribution of the smeared square field is also a
shifted Gamma distribution, but that the distribution of the energy density is
not.Comment: 9 pages, 1 figure. Minor edits implemente
Nickel hydrogen low Earth orbit test program update and status
The current status of nickel-hydrogen (NiH2) testing ongong at NWSC, Crane In, and The Aerospace Corporation, El Segundo, Ca are described. The objective of this testing is to develop a database for NiH2 battery use in Low Earth Orbit (LEO) and support applications in Medium Altitude Orbit (MAO). Individual pressure vessel-type cells are being tested. A minimum of 200 cells (3.5 in diameter and 4.5 in diameter) are included in the test, from four U.S. vendors. As of this date (Nov. 18, 1986) approximately 60 cells have completed preliminary testing (acceptance, characterization, and environmental testing) and have gone into life cycling
Contact, Perspective Taking, and Anxiety as Predictors of Stereotype Endorsement, Explicit Attitudes, and Implicit Attitudes
We proposed a model of intergroup contact wherein contact promotes understanding of outgroup perspectives, perspective taking relates to reduced intergroup anxiety that in turn is associated with lessened stereotyping and more positive intergroup attitudes. Additionally, we examined if implicit attitudes followed this model or were directly impacted by contact. White undergraduates (n = 153) completed measures of contact, perspective taking, intergroup anxiety, stereotype endorsement, and implicit and explicit intergroup attitudes. Our model fitted the data well but explained explicit attitudes and stereotyping better than implicit attitudes. Supporting an environmental association interpretation, contact was the only significant predictor of implicit attitudes. Findings support a dual-process model wherein implicit and explicit attitudes represent separate constructs and support the value of contact in improving intergroup attitudes
Local Thermal Equilibrium in Quantum Field Theory on Flat and Curved Spacetimes
The existence of local thermal equilibrium (LTE) states for quantum field
theory in the sense of Buchholz, Ojima and Roos is discussed in a
model-independent setting. It is shown that for spaces of finitely many
independent thermal observables there always exist states which are in LTE in
any compact region of Minkowski spacetime. Furthermore, LTE states in curved
spacetime are discussed and it is observed that the original definition of LTE
on curved backgrounds given by Buchholz and Schlemmer needs to be modified.
Under an assumption related to certain unboundedness properties of the
pointlike thermal observables, existence of states which are in LTE at a given
point in curved spacetime is established. The assumption is discussed for the
sets of thermal observables for the free scalar field considered by Schlemmer
and Verch.Comment: 16 pages, some minor changes and clarifications; section 4 has been
shortened as some unnecessary constructions have been remove
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