Removal and Containment of High-Level Radioactive Polonium From Liquid Lead-Bismuth Coolant

1997 ◽  
Vol 506 ◽  
Author(s):  
E.I. Yefimov ◽  
D.V. Pankratov ◽  
S.V. Ignatiev
Keyword(s):  
High Energy ◽  
Liquid Lead ◽  
Alkaline Extraction ◽  
Vacuum Sublimation ◽  
Safety Standards ◽  
Experimental Apparatus ◽  
The Us ◽  
High Level ◽  
Secondary Neutrons ◽  
Spallation Product

ABSTRACTThe channels of polonium nuclide formation in lead-bismuth target irradiated by high energy protons and secondary neutrons are considered. Under off blanket condition the activity of 200po -210Po, as well as the fission and spallation product activity are calculated for 15 MW target after 1 year operation. Polonium separation methods, including removal using alkaline extraction, vacuum sublimation, and so-called carrier method are analyzed. The engineering design for experimental apparatus to test polonium removal and containment using alkaline extraction using tellurium as a chemical analog of polonium is developed. The necessary degree of polonium removal to keep concentration below levels appropriate to meet the US and Russia safety standards is estimated. Comparative analysis of alkaline extraction and vacuum sublimation techniques from the viewpoint to achieve the necessary removal depth is carried out.

scholarly journals Has the Propensity to Pay Dividends Declined? Evidence from the US Banking Sector

2021 ◽  
Vol 14 (3) ◽  
pp. 103
Author(s):  
Shaojie Lai ◽  
Qing Wang ◽  
Jiangze Du ◽  
Shuwen Pi
Keyword(s):  
Banking Sector ◽  
Logit Models ◽  
Sample Period ◽  
Financial Firms ◽  
The Us ◽  
The Difference ◽  
High Level ◽  
Propensity To Pay ◽  
Financial Firm ◽  
Very High

This article examines the propensity to pay dividends in the U.S banking sector during 1973–2014. Although the propensity to pay dividends has been declining over the 52 years of our sample period, banks are consistently more likely to pay dividends than non-financial firms. Using the coefficients from logit models estimated early in the sample period to forecast the percentage of dividend payers in each subsequent year, we conclude that there has been a decline in the likelihood of paying dividends in the banking sector. However, the decline started from a very high level as compared to that of the non-banking sectors. In addition, the variables taken from the non-financial firm literature do not explain the difference between the actual and expected percentage of dividend payers in the banking sector. We also conduct exploratory analyses with bank-specific variables. Although newly included variables are significantly related to the likelihood of paying dividends, they do not explain the declining propensity to pay dividends in the banking sector.

June summits signal progress on EU-US trade ties

2021 ◽  
Keyword(s):  
Corporate Taxation ◽  
Gas Pipeline ◽  
Security Technology ◽  
Content Type ◽  
Transatlantic Cooperation ◽  
The Us ◽  
Us Government ◽  
Nord Stream ◽  
High Level ◽  
Two Sides

Significance The two sides have suspended tariffs arising from their dispute over subsidies to Airbus and Boeing, are working on an international deal on corporate taxation and have established a high-level council to discuss issues at the nexus of security, technology and trade. Impacts A major aim of closer transatlantic cooperation is better coordination of policies with respect to China. Closer transatlantic cooperation over China might soften US opposition to the Nord Stream 2 gas pipeline. It will be difficult for the US government to pass legislation concerning trade given the Democrats' precarious majority in both houses.

Teaching linguistics through language construction

2021 ◽  
Author(s):  
Yılmaz Köylü
Keyword(s):  
Language Learning ◽  
Linguistic Diversity ◽  
Project Based Learning ◽  
Learning Skills ◽  
The Us ◽  
Students First ◽  
Long Course ◽  
High Level ◽  
Semantic Properties ◽  
Specific Project

Abstract This article details how introductory linguistics courses can increase student engagement and learning through a project-based approach, whereby the students first study the subfields of linguistics with a view to complete the main project of the course, namely to construct a novel language. I provide information from a semester-long course with specific project-based activities teachers could utilize in their classes. I also thoroughly examine the constructed language projects based on 33 student submissions in an introductory linguistics course in the US. The analysis indicates a high level of engagement and creativity by the students in creating a distinct orthography, phonetic, morphological, and syntactic rules and semantic properties for their constructed languages. The results from a 20-item questionnaire and student exit interviews indicate that the project-based approach adopted in the completion of their constructed languages proved effective in (a) improving student motivation and engagement; (b) helping students apply the knowledge of the material to carry out linguistic analysis; (c) enhancing students’ language learning skills; (d) encouraging them to study additional foreign languages; and finally (e) promoting linguistic diversity. Hence, as an innovative and effective method still in its infancy, project-based learning should be more widely implemented in linguistics instruction.

scholarly journals Machine Safety: Risk Assessment, Risk Reduction

2006 ◽  
Author(s):  
Michael D. Ladd
Keyword(s):  
Risk Assessment ◽  
Risk Reduction ◽  
Equipment Design ◽  
Worker Safety ◽  
End User ◽  
Safety Risk ◽  
Safety Standards ◽  
The Us ◽  
Machine Safety

Worker safety is an issue of major concern worldwide. Evidence to this fact is noted with recent efforts to harmonize US machine safety standards with that of the European Machinery Directive. Changes to the US standards have a dramatic affect on new equipment design. Additionally, older machinery that is still in use must now be upgraded to meet these new requirements. In other words, the end user must now follow the same standards as new equipment manufacturers. Paper published with permission.

On sinterability of nanostructured W produced by high-energy ball milling

2007 ◽  
Vol 22 (5) ◽  
pp. 1200-1206 ◽  
Author(s):  
R. Malewar ◽  
K.S. Kumar ◽  
B.S. Murty ◽  
B. Sarma ◽  
S.K. Pabi
Keyword(s):  
Sintered Density ◽  
Sintering Temperature ◽  
High Energy ◽  
Deformation Bands ◽  
Dramatic Decrease ◽  
Powder Charge ◽  
Grinding Media ◽  
Energy Ball ◽  
High Level ◽  
First Time

The present investigation reports for the first time a dramatic decrease in the sintering temperature of elemental W from the conventional temperature of ≥2500 °C to the modest temperature range of 1700–1790 °C by making the W powder nanostructured through high-energy mechanical milling (MM) prior to sintering. The crystallite size of the initial W powder charge with a particle size of 3–4 μm could be brought down to 8 nm by MM for 5 h in WC grinding media. Further milling resulted in a high level of WC contamination, which apparently was due to work hardening and the grain refinement of W. A sintered density as high as 97.4% was achieved by sintering cold, isostatically pressed nanocrystalline (8 nm) W powder at 1790 °C for 900 min. The microstructure of the sintered rods showed the presence of deformation bands, but no cracks, within a large number of W grains. The mechanical properties, when compared with the hardness and elastic modulus, of the sintered nano-W specimen were somewhat superior to those reported for the conventional sintered W.

scholarly journals High Altitude Makes for High Energy

2018 ◽  
Vol XII (1) ◽  
pp. 99-101
Author(s):  
Tin Wegel
Keyword(s):  
High Energy ◽  
Indiana University ◽  
Lifelong Learners ◽  
Conference Room ◽  
Northern Colorado ◽  
The Us ◽  
Language Classrooms ◽  
University Of Northern Colorado ◽  
Performative Pedagogy ◽  
The University

On January 19, 2018 about 80 people sat in an unassuming conference room on the campus of the University of Northern Colorado in Greeley, chatting and signing away cheerfully with their seat neighbors in anticipation of the keynote address by Susanne Even from Indiana University in Bloomington, IN. The lively crowd of students and faculty members from across the country was clearly already in a chatty mood before the official introduction by Erin Noelliste, the lead organizer of the 5th Scenario Symposium on Performative Pedagogy, kicked off an engaging and interactive evening and day ahead. The idea behind this particular symposium was to focus on the use of drama to enhance learning in education and foreign languages, as the program stated. It was the second of its kind held in the US and thus aimed at broadening readership and scope of the Scenario Journal, with the goal of inspiring creativity and improvisation in foreign language classrooms. The keynote speaker Susanne Even took the podium and I dare say she could not have hoped for a more involved group of lifelong learners. Her keynote talk, made accessible to all participants by sign language interpreters, was the first presentation in the 2018 ...

ENERGY EFFICIENT LIGHTING OF PUBLIC PREMISES

2021 ◽  
pp. 54-56
Author(s):  
E. A. Kuznetsov ◽  
N. P. Nesterkina ◽  
Yu. A. Zhuravleva ◽  
S. A. Mikaeva
Keyword(s):  
Educational Institution ◽  
Light Output ◽  
Light Flux ◽  
High Energy ◽  
Educational Institutions ◽  
Energy Costs ◽  
Light Sources ◽  
Fluorescent Lamps ◽  
High Level ◽  
Incandescent Lamps

The article provides a technical and economic comparison of costs when covering 10 classrooms of a general educational institution with LED and fluorescent lamps for a period of 10 years. The main advantage of led light sources is the high level of light output compared to traditional light sources. Replacing incandescent lamps and gas-discharge ICS with led ICS can significantly reduce energy costs. Currently, led ICS are increasingly replacing traditional ICS due to their high energy efficiency and safety. For comparison, luminescent lamps LVO04-4x14-031 and LED lamps DVO12-45-003 produced by JSC “Ardatovsky lighting plant” with a comparable light flux and light distribution were selected. The number of lamps in the 65 m2 auditorium was chosen based on the normalized illumination of 500 Lux on a horizontal work surface (0.8 m). The calculation of the number of lamps that meet all the requirements for lighting in General and higher educational institutions was carried out in the DiaLux 4.13 program. According to preliminary calculations, lighting with led lamps will reduce energy costs over 10 years by 2.16 times compared to fluorescent lamps. The maximum expenses are spent on the purchase of new led lamps. This is mainly due to the higher price of led lighting devices compared to fluorescent ones.

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