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Number of results: 9
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Abstract

Polycyclic aromatic hydrocarbons (PAHs) belong to the group of recalcitrants that on reaching wastewater can irreversibly inhibit some sensitive biological processes in activated sludge such as nitrification. This situation leads to wastewater treatment failure due to the influence of these substances on bacteria responsible for important biochemical processes. Observation of the changes in bacterial diversity using molecular tools, such as denaturing gradient gel electrophoresis (DGGE), could be the first step in finding a way of preventing wastewater treatment failure. The aim of this experiment was to monitor bacterial biodiversity in a membrane bioreactor (MBR) dealing with synthetic wastewater contaminated with high concentration of petroleum organic compounds (POCs) and to study the influence of POCs contamination on bacterial changeability in activated sludge. COD removal in investigated membrane bioreactors was at a level of 93%. The organics removal efficiency was not affected by the maximal tested dose of petroleum contamination ( l OOO μl POCs/l of wastewater) and the MBRs wastewater treatment performance was undisturbed. DGGE analysis revealed that the biodiversity fluctuated slightly in control MBR, while in experimental MBR the biodiversity index decreased drastically after adding the highest experimental concentration of POCs. These results suggest that concentrations of POCs at levels from 50 μl/l to 500 μl/l stimulate biodiversity growth, while the concentration I OOO μI POCs/1 of wastewater seems to inhibit the most sensitive processes in wastewater treatment by influencing the bacterial biocenosis.
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Authors and Affiliations

Aleksandra Ziembińska
Sławomir Ciesielski
Jarosław Wiszniowski
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Abstract

The geographical location and climatic conditions of Ukraine cause the active development of land reclamation, as it enables to ensure stable and high yields. The complexity of forecasting in this area, namely the dependence of the results onthe changing weather and climate conditions, does not allow to effectively use the standard instruments for justifying the investment for agricultural and land reclamation innovation.

The necessity of improving methodological approaches to evaluating the effectiveness of investments in projects in the field of agricultural production and land reclamation was substantiated. The proposed approaches were tested on the ad-vanced technology of water treatment in irrigation based on using a vibrating gravitation filter enabling to perform simultaneously the processes of water treatment and filter element regeneration.

The obtained results clearly show that the advancedtechnology of irrigation water treatment and the developed for this technology design of the vibrating gravity filter are cost-effective. The current payback period for irrigation projects when using the purified water under this advanced technology is 5 years. It is the same as for the irrigation projects when using clean irrigation water.

Thus, our proposed approaches to the evaluation of investments in new water treatment technologies applied in irriga-tion enable to adapt the modern methodology of analysis of economic and investment efficiency of projects to the domestic needs of agricultural production, namely to take into account the impact of changing weather and climate conditions on the resulting economic parameters.

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Authors and Affiliations

Anatoliy Rokochinskiy
ORCID: ORCID
Vyacheslav Bilokon
Nadia Frolenkova
ORCID: ORCID
Nataliіa Prykhodko
ORCID: ORCID
Pavlo Volk
ORCID: ORCID
Ruslan Tykhenko
ORCID: ORCID
Ivan Openko
ORCID: ORCID
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Abstract

The study investigates the effect of the organic compound representing the cellulose derivative - sodium salt of carboxymethyl cellulose (CMC/Na) on the structure of the main component of bentonite (B) - montmorillonite (MMT). Structural analysis revealed that the CMC/Na of different viscosity interacts with the mineral only via surface adsorption, causing at the same time partial or full delamination of its layered structure. This was confirmed by the XRD diffraction tests. Such polymer destructive influence on the structure of the modified main component of the bentonite limits the use of its composites as an independent binder in moulding sand technology, but does not exclude it from acting as an additive being a lustrous carbon carrier. According to the IR spectra of the B/CMC/Na materials, it can be stated that the interaction between the organic and inorganic parts is based on the formation of hydrogen bonds. That kind of the interpretation applies especially to the MMT modified in the bentonite with a lower viscosity polymer. The characteristics of the main IR absorption bands for composites with a higher viscosity polymer indicates the formation of less stable structures suggesting the random nature of the hydrogen bonds formation.

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Authors and Affiliations

S. Cukrowicz
B. Grabowska
K. Kaczmarska
A. Bobrowski
M. Sitarz
B. Tyliszczak
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Abstract

The aim of the study was to determine biologic variations of the main parameters in cows in early lactation and to compare intra-individual variations of parameters in cows and other species. 50 cows were included in the experiment. Blood samples were taken at the moment of calving, then on 1st, 7th, 14th and 28th day after calving. CVi had the following values: 1.9-5% for MCV, MCH, MCHC, GLU, TProt, ALB, UREA, Ca, P and Mg; 5.1-10% for RBC, Hgb, Hct, WBC, NEU, LYM, BHB, ALT, CHOL, TGC and >10% for PLT, NEFA, TBil, AST and GGT. For RBC, Hgb, Hct, MCV, MCH subject-based reference values or the reference change value should be used. For all other parameters except AST, population-based reference intervals should be used with caution. For LYM, NEU, PLT, GLU, TProt, ALB, CHOL and TGC index of individuality was close to 0.6 which means that subject-based reference values can be much more adequate to use then population-based reference intervals. For AST population-based intervals should be used. There is little effect of parity (increase CVi with parity) and no effect of milk production. CVi values obtained in cows in early lactation are specific because they deviate from the CVi values of other animal species and human. Calculated RCVs varied from 5.5% for MCHC to 41% for AST. High individuality index for many metabolic parameters opens possibility for development of model for longitudinal monitoring of metabolic status of individual animals during lactation. That requires further research.
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Authors and Affiliations

V. Kovačević
1
M.R. Cincović
1
B. Belić
1
R. Đoković
2
I. Lakić
1
M. Radinović
1
A. Potkonjak
1

  1. Department of Veterinary Medicine, Faculty of Agriculture, University of Novi Sad, Trg D.Obradovića 8, 21000 Novi Sad, Serbia
  2. Faculty of Agronomy, University of Kragujevac, Ul. Cara Dušana 34, 32000 Čačak, Serbia
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Abstract

A hot compression test was conducted on a Gleeble-3500 thermo-simulation machine to study the critical conditions and kinetics of dynamic recrystallization in a high-carbon tool steel. The critical conditions for the initiation of dynamic recrystallization were determined using the working-hardening theory. The quantitative relationship between the critical characteristics of dynamic recrystallization and the hot deformation parameters were elucidated based on two different methods:the apparent method and physically based method. It was found that the two methods both have high applicability for the investigated steel, but the physically-based method needs less parameters and makes it possible to study the effect of different factors. A dynamic recrystallization kinetics model was used to calculate the recrystallization volume fraction under different conditions. The calculation results matched well with the data obtained from the flow curves.

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Authors and Affiliations

Yong-Ji Zhang
Guang-Liang Wu
Shang-Wen Wu
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Abstract

The aim of this research work was determination of humidity impact on yeast and moulds survival in fibrous filters. It was revealed that water content of about - 53-113% stimulated growth of fungi, especially in case of moulds. In stable filters humidity conditions (50% of weight), a number of fungi reached I 04 CFU/cm2 after 84 days, with the most intensive growth during first 7 days of the experiment. In the case of very low humidity ( 13% and less), the growth of fungi was not observed.
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Authors and Affiliations

Ewa Sztompka
Ewa Karwowska
Ewa Miaśkiewicz-Pęska
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Abstract

The article is a review of the book by Krzysztof Brzechczyn, On the Multitude of the Lines of Development in the Historical Process. An Attempt at Interpretation of Evolution of Mexican Society, Wydawnictwo Naukowe UAM, Poznań 2004, ss. 341.
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Authors and Affiliations

Mieszko Ciesielski
ORCID: ORCID
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Abstract

The authors of this paper examine the ancient concepts of translatio, imitatio and aemulatio. The text goes over some problems of the heritage of antiquity and its reception in European culture of the early modern period. These questions were discusssed during the international conference “Heredes et scrutatores. Attitudes towards Antiquity in the Renaissance and in the Early Modern Period”, which was held on 19–20 May 2016 at the University of Warsaw. It celebrated the 200th anniversary of classical studies at this university. The conference seeked to explore the changing attitudes towards the heritage of classical antiquity in post-classical European culture. The scholars participating in the meeting tried to (re)examine the diversity of these attitudes in the period between the Late Middle Ages and Early Modern Times and to reflect on a number of related problems, among which were the theoretical viewpoints that had been suggested to describe this diversity. One of them, which gave its name to this conference, distinguishes between two general approaches: that of the “users”, concentrated on adapting the classical legacy by means of procedures inherited from the ancient Romans, and that of the “researchers”, which replaced the former procedures with ones typical of scholarly cognition. The participants discussed theoretical issues and concrete cases illustrating the ways that the intellectuals of the Renaissance and Early Modern Times approached the Greek and the Roman legacy. The connections between past and present attitudes towards antiquity have also been be the subject of the debate.

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Authors and Affiliations

Barbara Milewska-Waźbińska
Włodzimierz Olszaniec

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