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Open access

Monika Śleziak and Marek Duliński

Abstract

The isotope activity concentration of rocks and bottom sediments was evaluated based on the samples collected from sedimentation ponds and gangue repositories. Radium 226Ra, thorium 228Th and potassium 40K activities were measured by gamma spectrometry using high-purity germanium detector – HPGe 4020. The radiation effect resulting from the presence of natural radionuclides was estimated by radiological hazard indices such as f 1 and f 2 coefficients, radium equivalent, internal and external hazard indices and absorbed dose rate. Performed measurements and calculations have shown that the bottom sediments are most contaminated. They may pose a serious radiological hazard for present and future generations.

Open access

Amir Ali, Muhammad Makshoof Athar, Mahmood Ahmed, Kashif Nadeem, Ghulam Murtaza, Umar Farooq and Muhammad Salman

Abstract

With the increased number of multi-drug formulations, there is a need to develop new methods for simultaneous determinations of drugs. A precise, accurate and reliable liquid chromatographic method was developed for simultaneous determination of paracetamol, thiamine, and pyridoxal phosphate in pharmaceutical formulations. Separation of analytes was carried out with an Agilent Poroshell C18 column. A mixture of ammonium phosphate buffer (pH = 3.0), acetonitrile and methanol in the ratio of 86:7:7 (V/V/V) was used as the mobile phase pumped at a flow rate of 1.8 mL min−1. Detection of all three components, impurities and degradation products was performed at the selected wavelength of 270 nm. The developed method was validated in terms of linearity, specificity, precision, accuracy, LOD and LOQ as per ICH guidelines. Linearity of the developed method was found in the range 17.5–30 µg mL−1 for thiamine, 35–60 µg mL−1 for pyridoxal phosphate and 87.5–150 µg mL−1 for paracetamol. The coefficient of determination was ≥ 0.9981 for all three analytes. The proposed HPLC method was found to be simple and reliable for the routine simultaneous analysis of paracetamol, thiamine and pyridoxal phosphate in tablet formulations. Complete separation of analytes in the presence of degradation products indicated selectivity of the method.

Open access

Andrej Martinčič, Tone Wraber and Igor Dakskobler

Abstract

In the alpine belt of the Julian Alps (glacial cirque Na Jezerih under Mt. Veliki Rokav, Jarečica, the Mangart Saddle and Prodi under Mt. Mangart as well as Mt. Plešivec in the rock wall of Loška Stena) we studied the phytosociology and ecology of snow-bed vegetation with dominating flowering plants Salix herbacea, Luzula alpinopilosa, Gnaphalium supinum, Soldanella pusilla and Salix retusa, and numerous moss species. Based on the comparison with similar snow-bed communities in the Central, Eastern and Southern Alps we described a new association Salicetum retuso-herbaceae and classified it into the alliance Salicion herbaceae and class Salicetea herbaceae. We determined several successional stages of snow-bed vegetation on mixed calcareous-silicate bedrock that we treat as variants, in two relevés also the initial association Polytrichetum sexangularis.

Open access

Sergio X. Lima, Karolina P. S. Costa, Zelmo R. Lima, Fagner C. Rother, Olga M. O. Araujo, Helio C. Vital, Tercio Brum, Wilson F. R. S. Junior, Jose Carlos C. Amorim, Matthew J. F. Healy and Edson R. Andrade

Abstract

The detonation of an (hypothetical) improvised nuclear device (IND) can generate atmospheric release of radioactive material in the form of particles and dust that ultimately contaminate the soil. In this study, the detonation of an IND in an urban area was simulated, and its effects on humans were determined. The risk of solid cancer development due to radiation was calculated by taking into account prompt radiation and whole-body exposure of individuals near the detonation site up to 10 km. The excess relative risk (ERR) of developing solid cancer was evaluated by using the mathematical relationships from the Radiation Effects Research Foundation (RERF) studies and those from the HotSpot code. The methodology consists of using output data obtained from simulations performed with the HotSpot health physics code plugging in such numbers into a specific given equation used by RERF to evaluate the resulting impact. Such a preliminary procedure is expected to facilitate the decision-making process significantly.

Open access

K. Szmuc, M. Kus-Liskiewicz, Ł. Szyller, D. Szmuc, M. Stompor, I. Zawlik, T. Ruman, S. Wołowiec and J. Cebulski

Abstract

The composite containing nanosilver uniformly deposited on matrix composed of CaHPO4 x 2H2O (brushite, ca 89 mass %), CaHPO4 (monteonite, ca 9.5 mass%), and Ag3PO4 (0.5 mas%) was obtained by addition of calcium nitrate and silver nitrate aqueous solution at 30:1 Ca:Ag molar ratio into excess of (NH4)2PO4 solution at pH 5.0 – 5.5. The isolated solid was characterized by STEM, XRD, and LDI mass spectrometry. It has been found that nanosilver was uniformly distributed within composite as <10 nm diameter sized nanoparticles. Determination of silver by AAS showed that 60% of silver is present as Ag(0) nanoparticles, the present as matrix Ag3PO4 as identified by XRD method. The composite showed strong growth inhibition in E. coli and P. aeruginosa strains, and moderate towards S. aureus. The C. albicans cells were the most resistant to the tested material, although still composite was moderately cytostatic for the yeast.

Open access

Alexander Druzhinin

Abstract

The World Ocean and, in particular, its resource potential have always had a dramatic effect on the progress and spatial organisation of humanity. Recently, the effect of the sea factor on the economy and the settlement system has increased amid globalisation, geoeconomic changes, increasing geopolitical turbulence, and the growing competition for resources. In this article, I attempt to assess the influence of the sea factor on the socioeconomic geography of the Russian Federation. A country with an extensive coastline and a vast inland area, Russia has territories that are very different in geographical terms. I pay special attention to the post-Soviet changes in the major components of the country’s maritime economy: seaports, fishing industry, offshore production, recreation, etc. Another focus is the assessment of these industries’ impact on the development of the coastal areas. I demonstrate the growing dependence between the maritime economy and the economic development of Russia’s inland regions. I identify the key natural geographic, foreign economy, settlement-related, and geopolitical factors of the coastalisation of the economy, infrastructure, and population, observed in Russia today. This process is taking place in the Baltic, Black, and Caspian Sea areas, as well as in the Arctic and Pacific regions of the country. I conclude that Russia’s integration into the system of multi-dimensional Eurasian partnerships (including the Belt and Road initiative) and the ‘turn to the East’ contribute to both the further ‘marinisation’ of Russian space and the differentiation of coastal zones by the level and rates of socio-economic development.

Open access

Nathalia Yeremenko

Abstract

The present paper studies the ruderal vegetation of the class of Robinietea in Kryvyi Rih. We present the spontaneous woody vegetation of parks and other artificial plantations. Urban landscapes remain unstudied phytosociologically despite the highly diverse habitat niches. We have carried out the comparisons of communities from other regions of Ukraine and adjacent territories. In total, four associations and one derivate community, belonging to three alliances, were identified and categorized as follows: Chelidonio-Acerion negundi (synanthropic tree communities with Acer negundo), Chelidonio majoris-Robinion pseudoacaciae (artificial and spontaneous plantations of Robinia pseudoacacia), Geo-Acerion platanoidis (artificial plantations of broad-leaved tree species). The ordination analysis indicates ecological differentiation of syntaxa investigated in Kryvyi Rih. The most important of them are soil aeration (Ae), the cryo-climate (Cr) and nitrogen content in soil (Nt). Critical revision of the class Robinietea syntaxonomy demands further current research.

Open access

Paweł Gładki

Abstract

In this paper we define root selections and 2p-th root selections for hyperfields: these are multiplicative subgroups whose existence is equivalent to the existence of a well behaved square root function and 2p-th root function, respectively. We proceed to investigate some basic properties of such root selections, and draw some parallels between the theory of root selections for hyperfields and the theory of orderings and orderings of higher level in hyperfields previously studied by the author.

Open access

Anna M. Baryła

Abstract

Green roofs play a significant role in sustainable drainage systems. They form absorbent surfaces for rainwater, which they retain with the aid of profile and plants. Such roofs therefore take an active part in improving the climatic conditions of a city and, more broadly, the water balance of urbanized areas. One of the factors influencing the hydrological efficiency of green roofs is the drainage layer. In the article, column studies were carried out under field conditions involving the comparison of the retention abilities of two aggregates serving as the drainage layer of green roofs, i.e. Leca® and quartzite grit. The average retention of the substrate was 48%; for a 5 cm drainage layer of Leca® retention was 57%, for a 10 cm layer of Leca average retention was 61%. For a 5 cm layer of quartzite grit average retention was 50%, for 10 cm layer of quartzite grit 53%. The highest retention was obtained for the column with the substrate and 10-centimeter layer of Leca®. At the same time, it was shown that Leca® is a better retention material than quartzite grit. The initial state of substrate moisture content from a green roof appears to be a significant factor in reducing rainfall runoff from a green roof; the obtained values of initial moisture content made for a higher correlation than the antecedent dry weather period.

Open access

Ivan Chajda and Helmut Länger

Abstract

Since the reduct of every residuated lattice is a semiring, we can ask under what condition a semiring can be converted into a residuated lattice. It turns out that this is possible if the semiring in question is commutative, idempotent, G-simple and equipped with an antitone involution. Then the resulting residuated lattice even satisfies the double negation law. Moreover, if the mentioned semiring is finite then it can be converted into a residuated lattice or join-semilattice also without asking an antitone involution on it. To a residuated lattice L which does not satisfy the double negation law there can be assigned a so-called augmented semiring. This can be used for reconstruction of the so-called core C(L) of L. Conditions under which C(L) constitutes a subuniverse of L are provided.