Multiplication Factor for Subcritical Multiplying System and the Efficiency of Source Neutrons

2021 ◽  
Vol 84 (8) ◽  
pp. 1424-1430
Author(s):  
L. S. Ershova ◽  
A. V. Lukin ◽  
D. V. Khmelnitsky
Kerntechnik ◽  
2020 ◽  
Vol 85 (1) ◽  
pp. 38-53
Author(s):  
M. J. Leotlela ◽  
I. Petr ◽  
A. Mathye

2020 ◽  
Vol 61 ◽  
pp. 54-60
Author(s):  
N. D. Orlova ◽  
D. A. Egorova

The clonal micropropagation technique of valuable Lonicera caerulea L. varieties (Indigo Gem, Moskovskaya 23, Diana, Jugana) has been improved. The effect of various types and concentrations of carbohydrates on microshoots regeneration of the genus Lonicera L. representatives was studied. It is shown that the concentration of carbohydrates has the greatest effect on microshoots height and the type of carbohydrate nutrition has the greatest effect on multiplication factor. The type of carbohydrate nutrition (42 %) had the greatest influence on multiplication factor. Peculiarities of varieties, genetic characteristics interaction, carbohydrate nutrition type and concentration had a lesser effect (20 %, 14 % and 11 % respectively). The variety Moskovskaya 23 was characterized by the highest microshoots number (49.6 mm). The highest multiplication factor in the studied varieties, regardless of the type of carbohydrate nutrition, was observed at concentration of 40 g/l (11.57).


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Helena Eri Shimizu ◽  
Josierton Cruz Bezerra ◽  
Luciano José Arantes ◽  
Edgar Merchán-Hamann ◽  
Walter Ramalho

Abstract Background Since 2004, Brazil has had a national policy for occupational health and safety. This policy means companies’ tax burden is altered according to the numbers of work-related accidents and ill-health amongst their workers. In 2010, a multiplication factor was introduced to this policy, called the Accident Prevention Factor. The idea of this new multiplication factor is to encourage individual employers to take initiatives to prevent accidents and ill health in the workplace. This study was designed to investigate the incidence of work-related accidents and ill-health in Brazil according to their causes, their severity, and the economic activity in which they occur, and to compare the data before and after the introduction of the Accident Prevention Factor. Methods An ecological study was conducted by analyzing the time series of work-related accidents/ill-health between 2008 and 2014 from the Brazilian social security system (Previdência Social) statistical yearbooks. Incidences were calculated per cause, economic activity, and severity of the accident/ill-health. Data from before and after the introduction of the Accident Prevention Factor were compared using the Mann-Whitney test per cause and per economic activity. Statistical analyses were made using the SPSS software, with significance set at 5%. Results A reduction in the incidence of work-related accidents/ill-health was found across all the groups of causes analyzed, except for the groups “external causes of morbidity and mortality” and “factors influencing health status and contact with health services.” Greater reductions were found for diseases of the musculoskeletal system and connective tissue and diseases of the nervous system. Reductions in work-related accidents/ill-health were found in the different economic activities and in the different severity groups. The highest reduction after the introduction of the Accident Prevention Factor was in manufacturing and production (p < 0.05). Conclusions Overall, the incidence of accidents/ill-health was found to be on decline, except those with external causes of morbidity and mortality and those involving factors influencing health status and contact with health services. The biggest reduction was found in manufacturing and production. However, generally speaking progress still needs to be made in accident prevention and occupational health across a whole range of work environments.


Author(s):  
Tomáš Czakoj ◽  
Evžen Losa

Three-dimensional Monte Carlo code KENO-VI of SCALE-6.2.2 code system was applied for criticality calculation of the LR-0 reactor core. A central module placed in the center of the core was filled by graphite, lithium fluoride-beryllium fluoride (FLIBE), and lithium fluoride-sodium fluoride (FLINA) compounds. The multiplication factor was obtained for all cases using both ENDF/B-VII.0 and ENDF/B-VII.1 nuclear data libraries. Obtained results were compared with benchmark calculations in the MCNP6 using ENDF/B-VII.0 library. The results of KENO-VI calculations are found to be in good agreement with results obtained by the MCNP6. The discrepancies are typically within tens of pcm excluding the case with the FLINA filling. Sensitivities and uncertainties of the reference case with no filling were determined by a continuos-energy version of the TSUNAMI sequence of SCALE-6.2.2. The obtained uncertainty in multiplication factor due to the uncertainties in nuclear data is about 650 pcm with ENDF/B-VII.1.


1975 ◽  
Vol 97 (3) ◽  
pp. 915-920
Author(s):  
G. Best Brown

It is becoming of great importance to develop processes which can utilize the “available cold” of LNG and thus recover the energy used for its liquefaction. It is possible to evaluate the amount of refrigeration that could be produced reversibly Q1, at a temperature T1, from the amount of cold available, Q2, at a lower temperature, T2, in an environment at T0. This is:Q1Q2≤T0−T2T0−T1·T1T2 For LNG it would be obtained that: Q1Q2≤13.5 Work is being done to develop cold multiplication cycles which would approach this ideal figure. Among the systems under development is an absorption process resembling a reversal of the well-known absorption refrigerator. An ethane-neoheptane system is presented for which the multiplication factor has been around 1.8 and the efficiency of around 17 percent. The irreversibilities of the cycle and the low enthalpy of mixing of hydrocarbons are the main reasons for the relatively low cold multiplication factor and thermodynamic efficiency.


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