40 research outputs found

    Pastoralism and Emergent Complex Settlement in the Middle Bronze Age, Azerbaijan: Isotopic analyses of mobility strategies in transformation

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    Objectives. This article explores the scale and seasonal patterns of mobility at the complex settlement site of Qızqala during the Middle Bronze Age (2400–1,500 BCE). By integrating human bone, teeth, and environmental samples this research tests the hypothesis of the persistent importance of community-wide seasonal pastoral transhumance during the early formation of complex settlement systems of the South Caucasus. Methods. This research applies stable oxygen and radiogenic strontium isotope analyses on incremental samples of human tooth enamel, bulk tooth enamel, and bone to resolve mobility patterns. Sequential and bulk sampling techniques elucidate seasonal and residential mobility behaviors. Extensive environmental isotope samples of plant and water were collected through regional survey and establish local and regional isotopic baselines, which are compared to human isotope analysis results. Results. Qızqala individuals exhibit low isotopic variability compared to regional contemporaries. 87Sr/86Sr ratios from human remains indicate seasonal and residential isotopic variability within the baseline ranges of local landscapes. δ18O values display erratic patterns, but correspond to seasonal variability with fluctuations between highland and lowland altitudinal zone baseline values. Conclusions. Results suggest that isotopic analysis of multiple elements and sequential enamel samples offers finer resolution on the complexities of human mobility strategies and elucidate the daily lives of often overlooked mobile populations. Higher resolution of individual mobility reveals shared routine behaviors that underscore the importance of diverse social collaborations in forming complex polities in the South Caucasus

    Chemically bonded stationary phases with incorporated polar groups for liquid chromatography : the synthesis and surface properties

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    In recent years high performance liquid chromatography (HPLC) has gained a dominant position in the life sciences. The widespread use of this technique allows to perform an analysis of compounds which are used in various areas of human life. Currently, there are wide and fully untapped opportunities for synthesis of chromatographic packings with chemically bonded stationary phases. Some of the liquid chromatographic analyses needs the application of water-rich mobile phases (more than 85% water or a buffer). In such condition the performance of hydrophobic stationary phases indicate that the bonded ligands might be collapsing. This problem could be solved by increasing of organic content in the mobile phase which should improve solvation and bring bonded ligands back to the original conformation. To avoid this procedure, which reduces the retention and selectivity of the separation, it is possible to apply stationary phases with incorporated polar groups mixed with the original alkyl ligands (polar embedded stationary phases). Another possibility is to add some polar groups during endcapping procedure (polar end-capped stationary phases). This produces variation in the bonding. Chemically bonded stationary phases which include both hydrophobic and hydrophilic ligands are so-called mixed mode stationary pahses. These materials can be used in reversed phase liquid chromatography (RPLC) and there is also a possibility to use them in hydrophilic interaction liquid chromatography (HILIC). They allow to separate polar and non-polar analytes. Following the idea of green chemistry, especially green analytical chemistry, a series of stationary phases was synthesized. The obtained materials connect polar and hydrophobic groups in the structure of bonded ligands. These specific surface properties provide the stability of the stationary phase in pure water as a mobile phase. Surface properties of novel material were analyzed using various instrumental and chromatographic methods. Finaly, the mixtures of various compounds were applied to test the separation selectivity of stationary phases in various chromatographic system, including purely aqueous conditions

    Change of Ultrasound Energy Amount Put Into Sewage Sludge Depending on their Content of Dry Mass

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    Despite of many studies on the use of ultrasonic disintegration for sewage sludge conditioning, have not yet been generally accepted indicators to choose the best parameters of used ultrasound to assist in the process of dewatering sludge. Still the most important issue is to adjust proper quantities of introduced energy depending on the characteristic parameters of sewage sludge. The publication presents the results of studies which purpose was to determine the relation of ultrasound energy introduced during sonification of sewage sludge with variable contents of their dry mass. Based on the survey and after analysis of the results, we can conclude that the amount of ultrasound energy introduced into the sewage sludge depends strictly on the content of their dry mass. Together with the increase of dry matter content, grows the amount of energy introduced into sludge. Regardless of the used disintegrator’s power for sonification, for each analyzed amplitude, together with increasing exposure time, density of energy increased nonlinearly. For sludge treated sonification at a specific time, value of this parameter was also changing nonlinearly to the size of used amplitude. The greater the value of the amplitude, the quantity of energy introduced had higher values

    Absorption Enhancement in Si Solar Cells by Incorporation of Metallic Nanoparticles: Improved COMSOL Numerical Study Including Quantum Corrections

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    One of the crucial parameters affecting the solar cell efficiency is the absorption rate versus solar spectrum. Metallic nanoparticles deposited on the cell surface can mediate this process. Main mechanisms of absorption enhancement due to metallic nanoparticle plasmons were proposed: (1) the scattering of incident solar light causing increase of the optical path length inside active layer and local enhancement of the electric field; (2) near field coupling between plasmon and semiconductor and the direct generation of electron-hole pairs in the semiconductor. The field concentration effect can be described by classical electrodynamic theory, the coupling between metallic nanoparticle plasmons and band electrons in semiconductor substrate must be captured upon quantum mechanics. In this paper we took the challenge to develop fast and reliable method for calculation of device optical properties by application of COMSOL system appropriately configured to take into account these quantum effects, via the quantum modification of the dielectric function of semiconductor substrate and metallic components. The presented results indicate that the efficiency of energy transfer due to near field coupling of metallic nanoparticle plasmons with semiconductor substrate is much more effective than the absorption increase due to metallic nanoparticle plasmons scattering only

    Podstawowe zasady monitoringu hydromorfologicznego polskich rzek

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    This paper presents the key principles of the new Polish methodology for hydromorphological river surveys which is consistent with the provisions of the Water Framework Directive. This method proposes to investigate only the main watercourse of the water body. The assessment is based on cartographic maps, satellite images and the existing databases. Field surveys are limited to selected stretches of the water body. The classification of the river's ecological status and ecological potential is based on a hierarchical system comprising four elements: hydrological regime, river continuity, channel morphology and floodplain. They are evaluated in view of features characterized by selected attributes. The method is the same for natural and heavily modified water bodies, while a simplified methodology is used to investigate artificial water bodies. It does not account for differences in abiotic type, landscape or size of the catchment area. The results are presented in abridged and field protocols. The attributes are evaluated on a five-point grading scale or through a descriptive approach which supports the calculation of ecological quality ratios for quality elements, hierarchical system elements and the water body. The usefulness of the proposed method has been tested on 11 pilot water bodies. The presented approach enables to perform hydromorphological surveys of Polish rivers by 2015, as required under the Water Framework Directive.W pracy przedstawiono podstawowe założenia nowej, polskiej metodyki monitoringu hydromorfologicznego rzek (MHR), dostosowanej do wymogów Ramowej Dyrektywy Wodnej. Zgodnie z nią przewiduje się badanie jedynie całego głównego cieku jednolitej części wód. Ocena opiera się na materiałach kartograficznych i teledetekcyjnych oraz istniejących bazach danych. Prace terenowe wykonuje się w ograniczonym zakresie. Do oceny stanu i potencjału ekologicznego stosowany jest system hierarchiczny. Zakłada on dokonanie oceny czterech elementów: reżimu hydrologicznego, ciągłości rzeki, morfologii koryta i doliny zalewowej. Są one oceniane na podstawie licznych wskaźników charakteryzowanych przez wybrane atrybuty. W analogiczny sposób bada się cieki naturalne i silnie zmienione, w uproszczony cieki sztuczne. Sposób ten nie różni się dla wydzielonych typów biotycznych, krajobrazów i wielkości zlewni cieku. Wyniki oceny są prezentowane w protokołach kameralnych i terenowych. Atrybuty podlegają ocenie punktowej lub opisowej, która umożliwia obliczenie współczynników jakości ekologicznej wskaźników, elementów oraz jednolitej części wód. Przydatność metody MHR została sprawdzona w 11 pilotowych jednolitych częściach wód. Stwarza ona możliwość przeprowadzenia wymaganej oceny hydromorfologii cieków w Polsce do końca 2015 r., czego wymaga Ramowa Dyrektywa Wodna

    Hydromorphological survey of lowland rivers with the MHR method

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    Ramowa Dyrektywa Wodna 2000/60 wymaga wykonania monitoringu hydromorfologicznego rzek. Kraje członkowskie we własnym zakresie opracowują metodyki, zapewniające dokonanie oceny stanu i potencjału ekologicznego w przedziale 5 klas jakości. Przedstawiono wyniki badań pilotowych, wykonanych w Polsce za pomocą nowej metody MHR (Monitoring Hydromorfologiczny Rzek). Obejmowały one 11 jednolitych części wód powierzchniowych (JCWP) o łącznej długości 358,2 km, znajdujących się w różnych częściach kraju. Badania obejmowały jednolite części wód, głównie nizinne cieki naturalne. Określone współczynniki jakości ekologicznej (WJE) umożliwiają ocenę stanu ośmiu i potencjału ekologicznego trzech jednolitych części wód powierzchniowych. Wskazują również, które z 4 elementów i 16 wskaźników w największym zakresie wpływają na wynik oceny.The Water Framework Directive 2000/60 obligates to realize the monitoring of hydromorphological elements of rivers. Member states should establish methodology for the assessment of the state and ecological potential within the 5 quality classes. In this article the results of pilot studies carried out in Poland using a new MHR (River Hydro-morphological Monitoring) method are presented. The studies involved 11 water bodies, mainly lowland rivers in different parts of the country, with a total length of 358.2 km. The Ecological Quality Ratios (EQR) established during the study allow for assessing the state of eight and the ecological potential of three water bodies. They also indicate which of the 4 elements and 16 indices exert the largest influence on results

    Role of Phytohormones in Biomass and Polyphenol Accumulation in Salvia bulleyana In Vitro Culture

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    Salvia bulleyana is a plant native to the Chinese Yunnan Province. This species has been used in traditional Chinese medicine as a substitute for Danshen (the roots of Salvia miltiorrhiza). The aim of our study was to establish an effective system for propagating S. bulleyana shoots to obtain large amounts of material rich in bioactive compounds. Phytohormones were used to regulate shoot growth and regeneration potential and influence plant secondary metabolism. The shoot tips were incubated on a Murashige and Skoog agar medium supplemented with 0.1 or 0.5 mg/L IAA (indole-3-acetic acid) and the cytokinins benzylaminopurine (BAP), meta-topoline (M-T), 6-benzylaminopurine riboside (RBAP), N-benzyl-9-(2-tetrahydropyranyl)-adenine (BPA) or kinetin, (K) at concentrations of 0.5, 1 or 2 mg/L. It was observed that the type and concentration of growth regulator significantly influenced the regeneration potential of S. bulleyana shoots. The highest multiplication rate was obtained when 0.1 mg/L IAA and 2 mg/L BPA were used. Under these conditions, 100% of shoot tips formed buds and almost seven buds/shoot per explant were obtained after five weeks. Meanwhile, the highest biomass was found for shoots growing on a medium supplemented with 0.1 mg/L IAA and 1 mg/L M-T: 1.2 g of fresh weight and 0.17 g of dry weight. However, a medium with 0.1 mg/L IAA and 2 mg/L RBAP was most favorable for bioactive phenolic acid content, with a total polyphenol level (37.7 mg/g dw) 4.5 times higher than in shoots grown on medium without growth regulators (8.23 mg/g dw). Finally, optimal conditions were selected by TOPSIS (technique for order of preference by similarity to the ideal solution); the culture of S. bulleyana grown on an MS medium containing 0.1 mg/L IAA and 1 mg/L M-T was found to be the most efficient for polyphenol accumulation and can be used for the production of medicinally relevant compounds

    Influence of surface and structural properties on the initial release of risperidone from polymeric drug carriers

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    In this work, implantable drug formulation with risperidone on the basis of poly(L-lactide-co-glycolide) (L-PLGA) and poly(D,L-lactide-co-glycolide) (D,L-PLGA) as drug carries was developed. The influence of surface and structural properties on the initial release of risperidone during the first twenty four hours was determined. In this aim, high-performance liquid chromatography, nuclear magnetic resonance spectroscopy, scanning electron microscope and atomic force microscope were used. Significant differences between L-PLGA and D,L-PLGA matrices in all analyzed data were noted. The burst effect was not revealed for any of the studied polymers, however the released drug was almost five times larger for D,L-PLGA matrices. The L-PLGA copolymer revealed a significantly longer average length of the lactidyl and glycolidyl blocks than D,L-PLGA. Moreover, various characters of surface for analyzed matrices were shown, i.e. in case of L-PLGA the surface was porous and in case of D,L-PLGA it was nonporous. Undoubtedly, there were dependences between risperidone's initial release and the topography and the structure of polymeric matrices. We suppose that the larger drug release for L-PLGA was more associated with surface properties and thus structure of matrices. The obtained results showed the great potential of both polymers and possibility to choose the optimal polymer
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