Impact of method choice on inbreeding coefficient estimation : a study of inbreeding in five beef cattle breeds in Norway

In 2020 was genotyping implemented into the populations of Norwegian beef cattle breeds of Hereford, Charolais, Aberdeen Angus, Limousin and Simmental. This development provides an opportunity to estimate genomic inbreeding within the population of these Norwegian beef cattle breeds. Various methods were used for estimating inbreeding coefficients, including FVanRaden1, Fhom, Funi, FROH and Fped. When inbreeding is defined as identical-by-decent, estimators must range between 0 and 1 since they estimate probability (FROH and Fped). In contrast, when inbreeding is defined as the correlation between uniting gametes, estimators can take both positive and negative values ranging from -1 to 1 (FVanRaden1, Fhom, Funi). The software tools PLINK.v1.9, CFC and R-studio has been used for conducting the estimates. Two approaches of analyzes for FVanRaden1, Fhom, Funi, FROH in PLINK.v1.9 has been used. The first involved separate analysis by breeds, followed by a second approach where dataset contained all breeds, but each breed was coded as a family, and post-analysis was the breeds separate into individual datasets. The two approaches gave different estimates from FVanRaden1, Fhom, Funi, suggesting that the methods are sensitive to the reference allele frequencies. Correlations within methods conducted in the two approaches reveals that FVanRaden1 showed to have the lowest correlation with itself. FROH had a perfect correlation and are only influenced by the fit of parameter settings. Mean inbreeding coefficient showed to be lower than estimates from populations from other countries. The results from Fped analysis in this study align closely with the finding of Kleiven (2007) for the same Norwegian beef cattle breeds in 2006. This could be explained with a substantial import of genetic material from outside Norway. FROH divided the breeds into two groups where Hereford, Charolais and Aberdeen Angus all had an inbreeding of ~12% and Limousin and Simmental had an inbreeding of 4% and 5% respectively. Research has consistently shown the complexity of selecting an appropriate inbreeding coefficient, and this complexity is also evident in this study. However, the study highlights the advantages of using FROH, which is not sensitive to reference allele frequencies, allows for breed comparisons, and can differentiate between new and old inbreeding.M-H

Characterization of surface dielectric barrier discharge influenced by intermediate frequency for ozone production

The aim of this study is to investigate the effect of the intermediate frequency (1–10 kHz) of the sinusoidal driving voltage on the characteristics of a developed surface dielectric barrier discharge (SDBD)-based reactor having spikes on its discharge electrode. Moreover, its influence on the production of ozone and nitrogen oxide byproducts is evaluated. The results show that SDBD is operated in the filamentary mode at all the frequencies. Nevertheless, the pulses of the discharge current at high frequencies are much denser and have higher amplitudes than those at low frequencies. The analysis of the power consumed in the reactor shows that a small portion of the input power is dissipated in the dielectric material of SDBD source, whereas the major part of the power is consumed in the plasma discharge. The results of the ozone production show that higher frequencies have a slightly adverse effect on the ozone production at relatively high energy density values, where the ozone concentration is slightly decreased when the frequency is increased at the same energy density. The temperature of the discharge channels and gas is not a crucial factor for the decomposition of ozone in this reactor, while the results of the measurements of nitrogen oxides characteristics indicate that the formation of NO and NO2 has a significant adverse effect on the production efficiency of ozone due to their oxidation to another nitrogen oxides and their catalytic effect

Wind energy management of a standalone system operating at maximum power point

In this paper, the management and control of a standalone wind energy system versus variations of wind speed and load are investigated. The system includes a wind turbine coupled to a variable-speed permanent magnet synchronous generator (PMSG), rectifier,boost converter, power inverter, and an energy storage system(ESS). The ESS is a very important part to achieve system stability and support the maximum power point tracking(MPPT) operation. A simple off-line MPPT algorithm is introduced that can be accomplished using the boost converter. The system dynamic model is derived then the control and energy management algorithms are introduced to improve the system performance. The MATLABplatform has been utilized to simulate the proposed system under different disturbances in the load power and wind speed. The results show perfect management of the system energy, good performance of the DC link voltage, stable load voltage, and load frequency