70 research outputs found
Energy spectrum of a 2D Dirac electron in the presence of a constant magnetic field
In this paper we obtain exact solutions of a 2D relativistic Dirac oscillator
in the presence of a constant magnetic field. We compute the energy spectrum
and discuss its dependence on the spin and magnetic field strength.Comment: 7 page
Taxonomy of the order Mononegavirales: update 2016
In 2016, the order Mononegavirales was emended through the addition of two new families (Mymonaviridae and Sunviridae), the elevation of the paramyxoviral subfamily Pneumovirinae to family status (Pneumoviridae), the addition of five free-floating genera (Anphevirus, Arlivirus, Chengtivirus, Crustavirus, and Wastrivirus), and several other changes at the genus and species levels. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV)
DYNSYL: a general-purpose dynamic simulator for chemical processes
Lawrence Livermore Laboratory is conducting a safeguards program for the Nuclear Regulatory Commission. The goal of the Material Control Project of this program is to evaluate material control and accounting (MCA) methods in plants that handle special nuclear material (SNM). To this end we designed and implemented the dynamic chemical plant simulation program DYNSYL. This program can be used to generate process data or to provide estimates of process performance; it simulates both steady-state and dynamic behavior. The MCA methods that may have to be evaluated range from sophisticated on-line material trackers such as Kalman filter estimators, to relatively simple material balance procedures. This report describes the overall structure of DYNSYL and includes some example problems. The code is still in the experimental stage and revision is continuing
Process monitor design for an extraction column: an application of estimation/detection
The NRC Safeguards Program at LLL is directed toward developing a methodology for assessing the effectiveness of material control and accounting systems at processing/reprocessing facilities for special nuclear material. The methodology under development requires many types of mathematical models including performance models of safeguard components. Included in the class of safeguard components are real-time measurement systems which incorporate on-line estimators/detectors for the timely detection of material losses. Performance modeling generally involves mathematical model development and simulation of the physical process being measured. This report discusses the development of material estimator designs for a liquid--liquid extraction column using a reprocessing application. These designs are applicable to any processing unit which can be adequately represented by linear or nonlinear models in state space form. Although this work is discussed in the context of a plutonium extraction column, it is representative of two classes of safeguard components which are generic to any fuel cycle involving chemical separations/purifications
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Material accounting in a complex chemical processing unit: an application of estimation/detection
The design of a real-time material accounting technique for a complex chemical processing unit is considered. This technique is applied to a liquid--liquid extraction column where sensitive and/or expensive material is being processed. On-line material accounting is accomplished using a generalized likelihood ratio detector. It is shown that the detector performs well on simulated data which includes various diversion schemes
Rhines scale and spectra of the beta-plane turbulence with bottom drag
We study two-dimensional incompressible turbulence on the beta planeand propose a modification to the Rhines scale that takes into accountthe bottom friction
Optimal life stage for radiation sterilization of Anopheles males and their fitness for release.
Mating by male Anopheles mosquitoes (Diptera: Culicidae) was evaluated in the laboratory to assess fitness effects of radio-sterilization applied during different life stages of the malaria vectors An. stephensi Liston and An. gambiae Giles sensu stricto. After reproductive sterilization by gamma-irradiation (120 Gy), equal proportions of sterile and fertile (unirradiated) male adults were released into cages with virgin females and allowed to compete for matings. Radio-sterilization was applied when the males were pupae aged 0-7 h or 24-32 h, or adults aged <24 h or 24-55 h. After being radio-sterilized in the adult stage, males of both species competed effectively with unirradiated males, whereas those sterilized in the pupal stage obtained significantly fewer matings than unirradiated males from the same cohort. There was no evidence of females obtaining multiple inseminations. These findings emphasize the need to radio-sterilize males as adults in order to minimize the fitness cost. Such males may be intended for sterile insect technique population suppression or for trial releases of transgenic anophelines
COMPARISON OF RINSE SAMPLING METHODS FOR DETECTION OF SALMONELLAE ON EVISCERATED BROILER CARCASSES
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