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Number of results: 6
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Abstract

Biodegradation of organic matter by sulphate-reducing bacteria (SRB) isolated from soil from military testing ground and petroleum plants were investigated. The isolated microorganisms utilized low molecular weight compounds and participation of SRB in biodegradation of these compounds was similar in marine sediments and in soil (40-55%).
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Authors and Affiliations

Dorota Wolicka
Andrzej Borkowski
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Abstract

High concentrations of nitrogen dioxide in the air, particularly in heavily urbanized areas, have an adverse eff ect on many aspects of residents’ health. A method is proposed for modelling daily average, minimal and maximal atmospheric NO 2 concentrations in a conurbation, using two types of modelling: multiple linear regression (LR) an advanced data mining technique – Random Forest (RF). It was shown that Random Forest technique can be successfully applied to predict daily NO 2 concentration based on data from 2015–2017 years and gives better fit than linear models. The best results were obtained for predicting daily average NO 2 values with R 2 =0.69 and RMSE=7.47 μg/m . The cost of receiving an explicit, interpretable function is a much worse fit (R 2 from 0.32 to 0.57). Verification of models on independent material from the first half of 2018 showed the correctness of the models with the mean average percentage error equal to 16.5% for RF and 28% for LR modelling daily average concentration. The most important factors were wind conditions and traffic flow. In prediction of maximal daily concentration, air temperature and air humidity take on greater importance. Prevailing westerly and south-westerly winds in Wrocław effectively implement the idea of ventilating the city within the studied intersection. Summarizing: when modeling natural phenomena, a compromise should be sought between the accuracy of the model and its interpretability.
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Authors and Affiliations

Joanna Amelia Kamińska
1
Tomasz Turek
1

  1. Wrocław University of Environmental and Life Sciences
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Abstract

The aim of the study was to use regenerated activated carbon to adsorb phenol from a river. Coconut shell activated carbon was derived from used tap water filter cartridges. The activated carbon was carbonised and then activated with KOH at 200°C, under a nitrogen atmosphere. The resulting adsorbent was characterised on the basis of nitrogen adsorption by Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM) analysis and point of zero charge (pH PZC). The study of periodic adsorption included kinetic and equilibrium modelling, determined the effect of solution pH on efficiency and the possibility of regeneration and reuse of the adsorbent. The efficiency of phenol removal from model water was evaluated, followed by the possibility of their adsorption from a polluted river in Silesia Province. Phenol adsorption followed pseudo-second-order kinetics. The adsorbents showed high adsorption abilities, as determined by the Langmuir isotherm model. The model fits the experimental data well. The concentration of phenol in the river was in the range of 0.45–0.77 mg∙dm– 3, which means that its value was at least five times higher than the standard values. The use of regenerated activated carbon from waste filter cartridges removed phenol from the river by 78% using optimal test parameters.
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Authors and Affiliations

Anna Marszałek
1
ORCID: ORCID
Ewa Puszczało
1
ORCID: ORCID

  1. Silesian University of Technology, Faculty of Energy and Environmental Engineering, Konarskiego St, 18, 44-100 Gliwice, Poland
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Abstract

It is known that the basic variable in the cellular environment is temperature and low temperature decreases cellular metabolism rate. Also, low cellular metabolic activity reduces oxidative stress, resulting in low ROS production. The aim of this study was therefore to investigate the effect of 36.5°C (low) and 38.5°C (conventional) incubation temperatures during IVM on glutathione peroxidase activity of oocytes and blastocysts following fertilization. Bovine oocytes were matured in medium-199 for 22 hours at either 36.5°C or 38.5°C and they were subjected to in vitro fertilization (IVF). Putative zygotes were then transferred randomly into SOFaa embryo culture media with or without antioxidant (a mixture of GSH and SOD) until development to the blastocyst stage. Glutathione peroxidase enzyme (GSH-Px) activity was lower (p<0.05) in oocytes matured at low temperature than those of conventional temperature. Similarly, GSH-Px activity was lower (p<0.05) in blastocysts, which were obtained from oocytes matured at low temperature and cultured in antioxidants-supplemented embryo media. The GSH-Px activity of blastocysts, obtained from oocytes matured in low temperature, cultured in antioxidants-free embryo media was similar to blastocysts obtained from oocytes matured in conventional temperature, cultured in antioxidants-supplemented embryo media. The results of the present study show that decreasing the in vitro maturation temperature decreases antioxidant enzyme activity in both oocyte and blastocyst. Additionally, maturation of bovine oocytes at 36.5°C incubation temperature may provide an optimal thermal condition for the enzymatic antioxidant system of both oocytes and blastocyst.
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Authors and Affiliations

U. Şen
1

  1. Ondokuz Mayis University, Faculty of Agriculture, Department of Agricultural Biotechnology, 55139, Samsun, Turkey
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Abstract

This article presents the main stages and challenges in modelling and designing of modern ultrasonic welding and cutting systems. First, the key components of such a system, such as an ultrasonic stack (con- sisting of a high power ultrasonic transducer and a sonotrode) and a digitally controlled ultrasonic power supply with precise control of the output power, have been considered. Next, a concept of measurement system for verification and validation of mathematical models of ultrasonic stacks and its components has been presented. Finally, a method of ultrasonic stack e-diagnosis based on ultrasonic transducer electrical impedance measurement during welding and cutting process has been described
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Authors and Affiliations

Andrzej Milewski
Piotr Kluk
Witold Kardyś
Paweł Kogut

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