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Number of results: 6
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Abstract

Dynamics of a weakly nonlinear and weakly dispersive flow of a gas where molecular vibrational relaxation takes place is studied. Variations in the vibrational energy in the field of intense sound is considered. These variations are caused by a nonlinear transfer of the acoustic energy into energy of vibrational degrees of freedom in a relaxing gas. The final dynamic equation which describes this is instantaneous, it includes a quadratic nonlinear acoustic source reflecting the nonlinear character of interaction of high-frequency acoustic and non-acoustic motions in a gas. All types of sound, periodic or aperiodic, may serve as an acoustic source. Some conclusions about temporal behavior of the vibrational mode caused by periodic and aperiodic sounds are made.

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Authors and Affiliations

Anna Perelomova
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Abstract

Heavy metal contamination often accompanies pollution with petroleum oil derivatives. Metal ions may considerably affect the process of hydrocarbon biodegradation. The results obtained for bacterial strains Gordon ia a/kanivorans S7 and Pseudom on as fluorescens SL3 indicated the limitation of cell growth and reduced ability of degradation of petroleum oil hydrocarbons in the presence ferric ions in the range of 15-100 mg Fe/dm3. However, the addition of these ions in the range of 1-7 mg Fe/dm3 might appear to be advantageous for biodegradation process. Supplementation with ferric ions in the range of 50-100 mg Fe/dm' decreases emulsifying activity of tested strains. The excess of these ions is accumulated in the bacterial cells.
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Authors and Affiliations

Ewa Kwapisz
Aneta Piątkowska
Małgorzata Piotrowicz-Wasiak
Jacek Polak
Stanisław Bielecki
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Abstract

In this study, the effect of calcium treatment on the mechanical properties and fatigue behavior of low carbon steel material is investigated. By applying calcium treatment after aluminum deoxidation for steel cleanliness, the aim is to transform the inclusions into harmless structures and produce cleaner liquid steel. As a result of the study, calcium treated material’s tensile strength slightly increases while fatigue life decreases. SEM studies were conducted to evaluate the results and it was observed that while elongated inclusions were observed as well as spherical shapes in the untreated sample, the inclusions generally had a spherical shape in the calcium treated sample. After the steel cleanliness process, the mechanical properties of the samples were improved. The tensile strength of the calcium treated sample increased slightly. However, a significant decrease in fatigue strength was observed depending on brittle inclusions that occur as a result of the calcium treatment process.
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Authors and Affiliations

Barış Karabayrak
1
ORCID: ORCID
Sinem Baskut
2
ORCID: ORCID
Dilek Turan
1
ORCID: ORCID

  1. Eskisehir Technical University, Faculty of Aeronautics and Astronautics, Department of Airframe and Power Plant Maintenance, Eskisehir, Turkey
  2. Eskisehir Technical University, Faculty of Engineering, Department of Materials Science and Engineering, Eskisehir, Turkey
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Abstract

This study set out to investigate, for the first time, the distribution and colocalization pattern of cocaine-and amphetamine-regulated transcript (CART) and one of the calcium binding-proteins: parvalbumin (PV) in the chinchilla’s hippocampus proper (HP). HP, consisting of Ammon’s horn (CA) and the dentate gyrus (DG), is an important component of the limbic system, involved in learning and memory processes. CA showed a higher immunoreactivity of CART (-IR) compared to DG. CART-IR neurons were mainly observed in the molecular layer of DG and in the pyramidal layer of CA. CART-IR fibers were present in the granular layer; in the hilus numerous mossy fibers were detected, while in the molecular layer CART-IR fibers were not found. In all CA fields (CA1-CA3), CART-IR fibers were only present in the lacuno- sum-molecular layer. Immunofluorescence with double- labeling showed that only CART-IR cells stained positive for PV, whereas in CART-IR fibers there was no PV-positive reaction. Our research supplements missing knowledge about the distribution and colocalization pattern of CART with PV in the chinchilla’s hippocampus, and also provides a better understanding of the similarities and differences among individuals of the same species and also with other mammals.

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Authors and Affiliations

R. Szalak
M. Matysek
W. Kukula-Koch
K. Rycerz
A. Zacharko-Siembida
M.B. Arciszewski

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