Considerations in the assessment of the consequences of effluents from mixed oxide fuel fabrication plants

The purpose of this study was to provide information and identify parameters relevant to assessing the consequences to man and his environment of large scale mixed plutonium-uranium oxide fuel fabrication plants which will be needed in the next 10 to 15 years. The report identifies the pertinent parameters, values, factors and methods which may be used in evaluating the environmental consequences of routine plant operation as well as postulated accidents. This study provides a base for the development of siting criteria and safety analyses for mixed oxide fuel fabrication facilities. (auth

Abraham Lincoln Sixteenth President of the United States of America

The color lithograph depicts a seated portrait of Abraham Lincoln. Lincoln sits in a chair with a small table to his proper right. On the table sits a copy of the Emancipation Proclamation, and ink well, and books. The image features hues of black, white and blue and is printed on off-white paper. It is probably after a photo by Alexander Gardner (see O-49 through O-53).https://scholarsjunction.msstate.edu/fvw-prints/1096/thumbnail.jp

Sizes of Masing Parts of Massive Star Forming Regions

It is shown that the images, line profiles, and time evolution of different interstellar masing transitions can be explained by the hypothesis that the population inversions giving birth to masers take place in turbulent regions with extents that are orders of magnitude greater than the sizes of the maser spots. It is shown that the images of methanol masers in the turbulent model persist within considerable time and do not prevent measurement of the annual parallaxes using data on the 12 GHz methanol maser positions.Показано, что изображения, профили линий и временная эволюция различных переходов межзвездных мазеров могут быть объяснены в рамках гипотезы о том, что инверсия населенностей, приводящая к появлению мазеров, возникает в турбулентных районах с размерами, превышающими размеры мазерных пятен на порядки величины. Показано также, что изображения метанольных мазеров в турбулентной модели остаются неизменными в течение продолжительного времени, что позволяет проводить измерения годичных параллаксов по данным о положениях метанольных мазеров на 12 ГГц.Показано, що зображення, профілі ліній та часову еволюцію різних переходів міжзоряних мазерів можна пояснити в межах гіпотези про те, що інверсія населеностей, котра призводить до появи мазерів, виникає в турбулентних районах з розмірами, вищими за такі мазерних плям на порядки величини. Показано також, що зображення метанольних мазерів у турбулентній моделі залишаються незмінними протягом довгого часу, що дозволяє вимірювати річні паралакси за даними про розташування метанольних мазерів на 12 ГГц

An optimal series expansion of the multiparameter fractional Brownian motion

We derive a series expansion for the multiparameter fractional Brownian motion. The derived expansion is proven to be rate optimal.Comment: 21 pages, no figures, final version, to appear in Journal of Theoretical Probabilit

Joint Activity and Attenuation Reconstruction From Multiple Energy Window Data With Photopeak Scatter Re-Estimation in Non-TOF 3-D PET

Estimation of attenuation from positron emission tomography (PET) data only is of interest for hybrid PET-MR and systems where CT is not available or recommended. However, when using data from a single energy window, emission-based non-time-of-flight (TOF) PET attenuation correction (AC) methods suffer from “cross-talk” artifacts. Based on earlier work, this article explores the hypothesis that cross-talk can be reduced by using more than one energy window. We propose an algorithm for the simultaneous estimation of both activity and attenuation images, as well as, the scatter component of the measured data from a PET acquisition, using multiple energy windows. The model for the measurements is 3-D and accounts for the finite energy resolution of PET detectors; it is restricted to single scatter. The proposed energy-based simultaneous maximum likelihood reconstruction of activity and attenuation with photopeak scatter re-estimation algorithm is compared with simultaneous estimation from a single energy window simultaneous maximum likelihood reconstruction of activity and attenuation with photopeak scatter re-estimation. The evaluation is based on simulations using the characteristics of the Siemens mMR scanner. Phantoms of different complexity were investigated. In particular, a 3-D XCAT torso phantom was used to assess the inpainting of attenuation values within the lung region. Results show that the cross-talk present in non-TOF maximum likelihood reconstruction of activity and attenuation reconstructions is significantly reduced when using multiple energy windows and indicate that the proposed approach warrants further investigation