Use of Distribution Devices for Hydraulic Profiling of Coolant Flow in Core Gas-cooled Reactors

In setting up a reactor plant for the transportation-power module of the megawatt class an important task is to optimize the path of flow, i.e. providing moderate hydraulic resistance, uniform distribution of the coolant. Significant contribution to the hydraulic losses makes one selected design of the coolant supplies. It is, in particular, hemispherical or semi-elliptical shape of the supply reservoir, which is selected to reduce its mass, resulting in the formation of torusshaped vortex in the inlet manifold, that leads to uneven coolant velocity at the inlet into the core, the flow pulsations, hydraulic losses.To control the flow redistribution in the core according to the level of energy are used the switchgear - deflectors installed in a hemispherical reservoir supplying coolant to the fuel elements (FE) of the core of gas-cooled reactor. This design solution has an effect on the structure of the flow, rate in the cooling duct, and the flow resistance of the collector.In this paper we present the results of experiments carried out on the gas dynamic model of coolant paths, deflectors, and core, comprising 55 fuel rod simulators. Numerical simulation of flow in two-parameter model, using the k-ε turbulence model, and the software package ANSYS CFX v14.0 is performed. The paper demonstrates that experimental results are in compliance with calculated ones.The results obtained suggest that the use of switchgear ensures a coolant flow balance directly at the core inlet, thereby providing temperature reduction of fuel rods with a uniform power release in the cross-section. Considered options to find constructive solutions for deflectors give an idea to solve the problem of reducing hydraulic losses in the coolant paths, to decrease pulsation components of flow in the core and length of initial section of flow stabilization.</p

Validation of novel food safety climate components and assessment of their indicators in Central and Eastern European food industry

Important insight into the Central and Eastern European food industry, beyond traditional food safety (FS) management and reflects on its food safety climate or the human route of its food safety culture is provided. Novel FS climate self-assessment tool was developed and validated by 65 FS experts from governmental agencies, third party certification bodies, food sector associations, universities and food industry. Three original FS climate components: FS knowledge, business priorities and FS legislation, were introduced and their nine components were assessed in nine Central and Eastern European countries involving 470 food companies. FS knowledge was better assessed in big and medium sized than in small companies. Knowledge component was equally assessed as good, irrespective of the FS risk profile of the food company surveyed while certified FS management system was charted by higher FS knowledge scores within a same food company. Business priorities in Central and Eastern European food organizations were related to hygiene and food safety and were always put before profit regardless of the company size. Hygiene and food safety were seen equality as a critical business success factor irrespective of the associated level of riskiness. FS climate legislation component in all food organizations surveyed was assessed affirmatively. Central and Eastern European food companies seemed to avoid problems in cooperation and trust between food safety leaders and other employees, since they have perceived FS climate highly and similarly. EU operating food companies had comparable overall FS climate to non-EU companies mostly because they have equally perceived their business priorities and appropriateness of associated FS legislation. The only exception was the FS knowledge that was better assessed in EU than non-EU food enterprises

Association of single nucleotide polymorphisms in leptin (LEP) and leptin receptor (LEPR) genes with backfat thickness and daily weight gain in Ukrainian Large White pigs

© 2018 Elsevier B.V. Leptin (LEP) and leptin receptor (LEPR) genes play an important role in the regulation of fat deposition and other commercially important traits in pigs and this regulation is known to be breed-specific. The aim of the present study was to investigate the presence and frequency of LEP polymorphisms g.2845A > T, g.3996T > C, and LEPR polymorphisms c.232A > T, c.915C > T and c.2856C > T in Ukrainian Large White pigs, and to determine whether these polymorphisms are associated with the following traits: backfat thickness at the 10th rib, backfat thickness at the 6-7th rib, backfat thickness at sacrum and average daily weight gain. The study was conducted on 108 Ukrainian Large White purebred female pigs. Genotyping of LEP and LEPR polymorphisms was performed using RCR-RELF technique. The study demonstrated that the LEP SNP g.2845A > T was segregating in the population of Ukrainian Large Whiter pigs studied with almost equal frequencies of the alternative alleles being observed. The LEP SNP g.3996 T > C was absent in Ukrainian Large White pigs with all the animals having g.3996CC genotype. The LEPR SNP c.915C > T was segregating in the pig population studied with c.915C allele frequency dominating. Segregation was also observed for the LEPR SNP c.2856 C > T with an almost equal frequency of the alternative alleles. The LEPR SNP c.232A > T was polymorphic with the frequency of the alternative alleles c.232A and c.232T being 0.25 and 0.75 respectively. No association was established between any of the traits investigated and the LEP SNP g.2845 A > T, LEPR SNP c232A > T, and LEPR SNP c.915C > T. The LEPR SNP c.2856C > T was associated with backfat thickness at the level of 6-7th and 10th ribs with c.2856TT genotype having lower backfat thickness compared to c.2856CC and c.2856CT. The LEPR SNP c.2856C > T was also associated with average daily weight gain which was lower in animals with c.2856TT genotype. Results of the study suggest that LEPR SNP c.2856C > T can be considered as a genetic marker for subcutaneous fat deposition and average daily weight gain in Ukrainian Large White pigs. This marker can be of particular importance in breeding programmes aiming to modify the carcass structure and pigs growth rate

Covid-19 pandemic effects on food safety - Multi-country survey study

This study provides an important insight into the response of food safety systems during the first months of the pandemic, elevating the perspective of preventing Covid-19 within conventional food safety management systems. A multi-country survey was conducted in 16 countries involving 825 food companies. Based on the results of the survey, it is obvious that the level of maturity of a food safety system in place is the main trigger in classifying companies and their responses to the pandemic challenge. Staff awareness and hygiene are the two most important attributes in combating Covid-19, opposed to temperature checking of workers in food establishment and health protocols from the World Health Organization, recognized as attributes with limited salience and importance. Companies confirmed implementation of more restrictive hygiene procedures during the pandemic and the need for purchasing more additional personal protective equipment. Retailers were identified as the food supply chain link mostly affected by the pandemic opposed to food storage facilities ranked as least affected. During this challenging period, all companies declared that food safety has not been compromised at any moment. It is important to note that less than a half of the food companies had documented any emergency plans associated with pandemics and health issues in place