Testing heat supply networks for heat losses

The scope of operations of the branch where the survey was carried out is: transmission and distribution of heat and heating medium to consumers through heat supply networks, maintaining the proper quality and amount of thermal power and heating medium supplied, ensuring contractual activities with heat consumers, as well as control of compliance with the consumption regimes stipulated by contracts, ensuring payments from consumers for supplied heat and heating medium, development and implementation of measures ensuring maximum efficiency of heat supply activities. The purpose of the work performed is to determine the actual heat losses through the thermal insulation of the surveyed heating networks and to compare them with normative values. The article presents an analysis of materials on the heat supply system; test findings for actual heat losses in a heat supply pipeline; calculation of actual heat losses for each section and their adjustment to average annual operating conditions of the given heat supply network; comparison of calculation results with normative characteristics. The test findings are used in developing the output performance for the «Heat Loss» indicator and in setting of norms for operating heat losses. The heat supply source for the heat pipeline is the CHP-plant. The pipelines are routed above ground on high and low supports, as well as in crawl ways. The thermal insulation of the pipelines is mainly made of 50 mm blankets of mineral wool and is typical for heat supply networks. In overhauls of heat supply networks, polyurethane foam is partly used as thermal insulation

Prediction of continuous cooling diagrams for the precision forged tempering steel 50CrMo4 by means of artificial neural networks

Quenching and tempering of precision forged components using their forging heat leads to reduced process energy and shortens the usual process chains. To design such a process, neither the isothermal transformation diagrams (TTT) nor the continuous cooling transformation (CCT) diagrams from literature can be used to predict microstructural transformations during quenching since the latter diagrams are significantly influenced by previous deformations and process-related high austenitising temperatures. For this reason, deformation CCT diagrams for several tempering steels from previous works have been investigated taking into consideration the process conditions of precision forging. Within the scope of the present work, these diagrams are used as input data for predicting microstructural transformations by means of artificial neural networks. Several artificial neural network structures have been examined using the commercial software MATLAB. Predictors have been established with satisfactory capabilities for predicting CCT diagrams for different degrees of deformation within the analyzed range of data.DFG/CRC/48

Convergent evolution of complex genomic rearrangements in two fungal meiotic drive elements

Meiotic drive is widespread in nature. The conflict it generates is expected to be an important motor for evolutionary change and innovation. In this study, we investigated the genomic consequences of two large multi-gene meiotic drive elements, Sk-2 and Sk-3, found in the filamentous ascomycete Neurospora intermedia. Using long-read sequencing, we generated the first complete and well-annotated genome assemblies of large, highly diverged, non-recombining regions associated with meiotic drive elements. Phylogenetic analysis shows that, even though Sk-2 and Sk-3 are located in the same chromosomal region, they do not form sister clades, suggesting independent origins or at least a long evolutionary separation. We conclude that they have in a convergent manner accumulated similar patterns of tandem inversions and dense repeat clusters, presumably in response to similar needs to create linkage between genes causing drive and resistance

Phenotypic, biochemical and genomic variability in generations of the rapeseed (Brassica napus L.) mutant lines obtained via chemical mutagenesis.

The phenotypic, biochemical and genetic variability was studied in M2-M5 generations of ethyl methansulfonat (EMS, 0.2%) mutagenized rapeseed lines generated from canola, '00', B. napus cv. Vikros. EMS mutagenesis induced extensive diversity in morphological and agronomic traits among mutant progeny resulted in selection of EMS populations of B. napus- and B. rapa-morphotypes. The seeds of the obtained mutant lines were high-protein, low in oil and stabilized in contents of main fatty acids which make them useful for feed production. Despite the increased level of various meiotic abnormalities revealed in EMS populations, comparative karyotype analysis and FISH-based visualization of 45S and 5S rDNA indicated a high level of karyotypic stability in M2-M5 plants, and therefore, the obtained mutant lines could be useful in further rapeseed improvement. The revealed structural chromosomal reorganizations in karyotypes of several plants of B. rapa-type indicate that rapeseed breeding by chemical mutagenesis can result in cytogenetic instability in the mutant progeny, and therefore, it should include the karyotype examination. Our findings demonstrate that EMS at low concentrations has great potential in rapeseed improvement