Preparation of <SUP>57</SUP>Co sources for Mössbauer Spectroscopy

Małgorzata ?ołtowska,Izabela Cieszykowska,Tomasz Janiak,Tadeusz Barcikowski,Mieczysław Mielcarski 한국자기학회 2017 한국자기학회 학술연구발표회 논문개요집 Vol.2017 No.11

On some generalizations of the reversibility in nonunital rings

Małgorzata Elzbieta Hryniewicka,Małgorzata Jastrzebska 대한수학회 2019 대한수학회지 Vol.56 No.2

This paper is intended as a discussion of some generalizations of the notion of a reversible ring, which may be obtained by the restriction of the zero commutative property from the whole ring to some of its subsets. By the INCZ property we will mean the commutativity of idempotent elements of a ring with its nilpotent elements at zero, and by ICZ property we will mean the commutativity of idempotent elements of a ring at zero. We will prove that the INCZ property is equivalent to the abelianity even for nonunital rings. Thus the INCZ property implies the ICZ property. Under the assumption on the existence of unit, also the ICZ property implies the INCZ property. As we will see, in the case of nonunital rings, there are a few classes of rings separating the class of INCZ rings from the class of ICZ rings. We will prove that the classes of rings, that will be discussed in this note, are closed under extending to the rings of polynomials and formal power series.

Approaches to enhance UV light emission in ZnO nanomaterials

Małgorzata Norek 한국물리학회 2019 Current Applied Physics Vol.19 No.8

Zinc oxide (ZnO) has been regarded as one of the most promising candidate for efficient UV light emitted devices owing to its unique optical properties, such as direct wide band-gap and a large exciton binding energy. In many optoelectronical applications, reducing the size of the semiconductor down to nanometer scale is necessary. However, in ZnO nanostructures the UV emission can be drastically weakened owing to high surface-to-volume ratio, crystal imperfections, or unintentional defects. These factors induce competitive processes to the nearband- edge (NBE) excitonic recombination in the UV region, including defect-related radiative recombination, resulted in the emission in the visible part of the spectrum, or other quenching processes, resulted in dissipation of excitation energy in the form of non-radiative recombination. Therefore, for future applications a strategy is needed to limit the quenching processes and to optimize the NBE emission of the ZnO nanomaterials. In this review article, the most effective approaches to achieve this goal are summarized and discussed.

Modification of the alumina surface properties by adsorbed anionic polyacrylamide—Impact of polymer hydrolysis

Małgorzata Wisniewska,Stanisław Chibowski,Teresa Urban 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

The effects of solution pH and degree of polymer hydrolysis on the adsorption mechanism of anionicpolyacrylamide (PAM) on the alumina surface were investigated. The spectrophotometry, potentiometrictitration, microelectrophoresis and thermogravimetry were applied to determine polymer adsorbedamount, surface charge density and zeta potential of solid particles in the presence and absence of PVA,as well as thermal characteristics of Al2O3 surface with the adsorbed polymer, respectively. The obtainedresults indicate that adsorption of PAM decreases with the increasing pH. Additionally, the polymeradsorption level depends on its degree of hydrolysis (which is equivalent to the content of carboxylgroups).

UV plasmonic-based sensing properties of aluminum nanoconcave arrays

Małgorzata Norek,Maksymilian Włodarski,Piotr Matysik 한국물리학회 2014 Current Applied Physics Vol.14 No.11

For several decades the plasmonic behavior of materials has been almost exclusively studied in visible region. Emerging applications require, however, the development of efficient materials operating in UV range. In UV nanoplasmonics aluminum (Al) can play a leading role due to its advantageous electronic properties. Yet, there is still lack of reproducible method to obtain Al nanostructures with desired parameters. Al nanoconcaves can provide a way to overcome these limitations. Here, two different periodicities of the Al nanoconcaves arrays were analyzed. It was observed that the Al concaves can dramatically reduce the optical reflectivity as compared to flat, unstructured Al. At the same time pronounced reflectivity dips were discernible, which were ascribed to (0,1) plasmonic mode. The positions of the dips were at around 250 nm and 350 nm for Al concaves with interpores distance (Dc) of 246.3 nm and 456.7 nm, respectively. The refractive index sensitivity (RIS) was: ~191 nm/RIU for the Al concaves with Dc ¼ 246.3 nm, and ~291 nm/RIU for the Al nanoconcaves arrays with Dc ¼ 456.7 nm.

Investigations of flocculation possibilities of the water alumina suspension in the presence of nonionic polymer

Małgorzata Wisniewska,Stanisław Chibowski,Teresa Urban 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.1

The effect of solution pH and molecular weight of polyethylene glycol (PEG) and polyethylene oxide (PEO) on their adsorption as well as stability of the colloidal Al2O3 water suspension was studied. The following methods were applied: turbidimetry, spectrophotometry, viscosimetry, potentiometric titration and microelectrophoresis. It was shown that the increasing solution pH affects conformation of the adsorbed macromolecules which affects the stability properties of such systems. The polymer adsorption causes deterioration of the stability conditions of the investigated alumina systems in comparison to those without polymer at all investigated pH values. At pH 3 and 6 the effect of the suspension destabilization is significantly smaller than at pH 9. The most effective flocculent of Al2O3 water suspension is PEO of the molecular weight 218,000 at pH 9.

Envelope development and variation in Trachelomonas hispida (Euglenophyta)

Małgorzata Poniewozik,Emil Zięba,Ewa Sajnaga 한국조류학회I 2018 ALGAE Vol.33 No.4

In Trachelomonas hispida, the adult envelope that surrounds the monad is oval in shape and covered with spines. Developmentof the lorica is an interesting, but poorly known phenomenon. We observed in detail the formation of spinelessenvelopes of T. hispida using light microscopy and scanning electron microscopy. The results showed that youngcells formed delicate and net-like envelopes. The structure changed with age, and mature specimens had solid, thick loricaewith small pores. As the loricae aged, they changed their shape, and rope-like fibres from the external layer startedto unwind, progressing from the apical pore, exposing the underlying net-like structure. X-ray spectrometry showed thatFe was the major mineral component in young and mature loricae, whereas old loricae did not contain Fe salts, althoughthey did contain a high number of Mn compounds. We also noticed a different pattern of mineralization process in theenvelopes. Apart from the even distribution of mineral deposition over the entire lorica, we observed that it started fromthe apical pore and ended at the posterior end. There was considerable morphological variation in envelope shape andornamentation, which had collars and folds around the apical pore and process at the posterior end. This suggested thatmany varieties of T. hispida should be taxonomically reappraised. We also discuss a hypothetical role for the spines onlorica surfaces in aquatic ecosystems.

Electronic and magnetic properties of the [4Fe-4S] iron-sulfur clusters encapsulated in a single-walled semiconducting carbon nanotube

Małgorzata Wawrzyniak-Adamczewska 한국물리학회 2018 Current Applied Physics Vol.18 No.9

The electronic and magnetic properties of the charge neutral iron-sulfur clusters, [4Fe-4S], encapsulated in a semiconducting single-walled carbon nanotube, CNT(17,0), are examined within the density functional theory approach. We verified that for the isolated cluster, due to exchange coupling between the electron spins on iron ions, the antiferromagnetic ground state with the total spin S = 0 is formed. The encapsulation provides the significant charge transfer from the carbon nanotube to the embedded molecule. In consequence, a shift of the molecular levels with broadening of the HOMO-LUMO gap is observed, and the significant p-doping of the surrounding nanotube with narrowing its energy band gap occurs. This transferred charge is found to be localized on the iron centers and contributes to the reduction of the value of the magnetic moments on the iron centers. We find that, the antiferromagnetic arrangement of the magnetic moments on the molecule is preserved after encapsulation and no net magnetic moment is induced on the carbon nanotube. We also ascertained that the considered hybrid system is of the p-degenerated semiconducting type.

Influence of Pulsed Electric Field on Accumulation of Calcium in Lactobacillus rhamnosus B 442

Małgorzata Góral,Urszula Pankiewi,Monika Sujka,Radosław Kowalski,Dariusz Góral,Katarzyna Kozłowicz 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.1

Calcium is an element that performs many important functions in the human body. A study was conducted on the use of a pulsed electric field (PEF) to enrich cells of Lactobacillus rhamnosus B 442 in calcium ions. The highest concentration of calcium ions in bacterial cells (7.30 mg/g d.m.) was obtained at ion concentration of 200 μg/ml of medium and with the use of the following PEF parameters: field strength 3.0 kV/cm, exposure time 10 min, pulse width 75 ms and 20 h of culturing after which bacteria were treated with the field. Cell biomass varied in the range from 0.09 g/g d.m. to 0.252 g/g d.m., and the total number of bacteria ranged from 1010 CFU/ml to 1012 CFU/ml. Microscope photographs prove that calcium ions were situated within the cells of the bacteria, and electroporation contributed to an increase in the effectiveness of the ion bioaccumulation process. Samples containing calcium and subjected to electroporation displayed intensive fluorescence. The significance of this research was the possibility of using probiotic bacteria enriched with calcium ions for the production of functional food in subsequent studies.

Legislation on Space Security: South Korean and Poland Challenges

Małgorzata Polkowska 한국항공우주정책⋅법학회 2019 한국항공우주정책·법학회지 Vol.34 No.1

This article refers to the Space security legislation in South Korea and Poland. Both states have already prepared some legislation on Security in Space- the question is the following- if there is still a need of progress and if those presented legislation are sufficient for the practical purposes of the peaceful uses of Outer Space. South Korea is a much more experienced state in using space than Poland; the same seems with the legislation. Poland as less experienced state in this matter has lots of ambitions to create the efficient legislation on Space security, so it must follow the good examples of states and institution in this matter. One of them is Korea. On the other state, Poland as a Member of EU must implement the European law in space security (in particular SSA), which seems to be priceless and efficient for the international cooperation in Space.