56 research outputs found
Pastoralism and Emergent Complex Settlement in the Middle Bronze Age, Azerbaijan: Isotopic analyses of mobility strategies in transformation
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
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
Application of Fenton Reaction for Supporting Biological Wastewater Treatment from the Dairy Industry
The dairy industry is one of the most polluting of industries, not only in terms of the volume of effluent generated, but also in terms of its characteristics as well. The composition of waste water produced in the milk processing plants depends primarily on the type of production (such as fluid milk, butter, cheese, buttermilk, whey, yogurt, condensed milk, flavored milk, milk powder, ice cream, etc.). The factors influencing the composition and charge of waste water are the raw materials used, level of technology plant, cleaning and disinfection processes and the amount of water used. Still increased pollution, combined with increased industrial activity and increasingly restrictive laws concerning discharges, focuses on the problem of optimal industry wastewater treatment. High concentration of organic matter in dairy wastewater causes problems with their removal in biological methods. Combining advanced oxidation process (AOP) and biological process has received attention in recent years as a promising alternative for industrial wastewater treatment. Among biological treatment processes the sequencing batch reactor (SBR) have been widely applied for treating dairy wastewater. The advantages of this technology can include high flexibility and ease of adaptation of operating parameters. Sequencing batch reactor is the name given to wastewater treatment systems based on activated sludge, operated on a sequence changes of anaerobic and aerobic conditions in one reactor. Using AOP pretreatment is important to improve the biodegradability and produce an effluent that can be treated biologically These processes involve the generation of highly free radicals, mainly hydroxyl radical (HO) via chemical, photochemical and photocatalytic reactions. One of the most important AOP process is Fenton reaction. Effectiveness of Fenton reaction has been confirmed in the case of pharmaceutical wastewater, treatment of brines or treatment of paper pulp manufacturing effluents. The oxidation system based on the Fenton’s reagent (hydrogen peroxide in the presence of a ferrous salt under acidic conditions) has been used for the treatment of both organic and inorganic substances of the wastewater stream. The present study was aimed to treat the dairy wastewater by Fenton’s process and an aerobic sequencing batch reactor. The first part of this study examined the effect of operating conditions on Fenton`s process pretreatment of dairy wastewater. The effectiveness of the AOP pretreatment was assessed by evaluating wastewater biodegradability enhancement (BOD5/COD), as well as monitoring major pollutant concentrations (COD) with reaction time. The optimum dose Fe2+ and H2O2 was found to be 1.2 and 2.0 g/L, respectively. In a single biological treatment the average removal efficiencies of COD, and NH4+ were 67%, and 61%, respectively. Integration of Fenton`s process and biological treatment resulted in 93% removal of COD and 79% NH4+ from the dairy wastewater. The results indicated that the combined process would be a promising alternative for the treatment of dairy wastewater
Change of Ultrasound Energy Amount Put Into Sewage Sludge Depending on their Content of Dry Mass
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
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
Chromatographic analysis of nucleic acids constituents
Understanding the characteristics, role and structure of nucleic acids allowed to
answer questions about the disease processes. Today, nucleic acids and their constituents
are tools, which are used by molecular biology in medicine and biotechnology. Antisense
and gene therapy are intensively developing methods for possible treating or preventing
disease. They use short fragments of DNA or RNA - oligonucleotides to silence the genes
expression. They are not the only ones that allow analytical chemists to obtain information
about the state of our body. Determination of modified nucleoside allows detection
of cancer, while analysis of nucleotides allows the estimation of strengthening the immune
system.
There is a great need of sensitive, selective and precise methods of separation of nucleosides,
nucleotides and oligonucleotides and their qualitative and quantitative analysis.
Consequently liquid chromatography (LC) is the most commonly used for analysis of
nucleic acid constituents. The most widely used modes of LC include Ion Exchange Chromatography
(IEC) and Reversed Phase High Performance Liquid Chromatography (RP
HPLC). Both techniques have their advantages and disadvantages in the analysis of nucleosides,
nucleotides and oligonucleotides. In the case of IEC it is necessary to use high concentrations
of the salt in the mobile phase or concentration gradients, which considerably
limits the possibility of using MS detection. RP HPLC can be coupled with MS detection
but only when volatile salts are mobile phase components. On the other hand there is a
significant problem is the lack of sufficient selectivity for the most polar nucleosides and
nucleotides. RP HPLC MS is still most often used in the determination of nucleosides and
nucleotides, due to its high sensitivity and a comprehensive qualitative analysis.
Another system used for the HPLC analysis of oligonucleotides is Ion Pair Reversed
Phase High Performance Liquid Chromatography (IP RP HPLC). These compounds can
not be analyzed by RP HPLC due to their high polarity. The advantage of IP RP HPLC is
selectivity, achieved by a suitable choice of mobile phase composition and the possibility
of using MS. A disadvantage of IP RP HPLC in the analysis of oligonucleotides is however
lower sensitivity compared to RP HPLC.
During the last few years Hydrophilic Interaction Liquid Chromatography (HILIC)
was applied for the separation of mixtures of nucleosides, nucleotides, oligonucleotides
extracted from a biological or food samples. The presented results demonstrate the usefulness
of this method, however, the resolving power is limited due to the asymmetric peak
shape. On the other hand proper selection of the mobile and stationary phase can lead to
a high selectivity in the analysis of the most polar nucleosides, nucleotides and oligonucleotides,
which can not be separated by RP HPLC
Effect of pH and mobile phase additives on the chromatographic behaviour of an amide‐embedded stationary phase: Cyanocobalamin and its diaminemonochloro‐platinum(II) conjugate as a case study
Podstawowe zasady monitoringu hydromorfologicznego polskich rzek
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
Hydromorfologia rzek w Polsce - klasy jakości stanu ekologicznego
This work presents rules and results of classifications of hydromorphological status of watercourses used presently in Europe. The Water Framework Directive introduced an obligation to monitor hydromorphological elements of rivers, which include hydrological regime, river continuity and bed morphology. European standards require somewhat different quality indicators and the way of their assessment for such investigations. Classification of status and ecological potential shall include categories and types of rivers, however, the methods existing so far do not provide such a distinction. Assessment of much differentiated features and attributes, as well as the requirement of presenting the outcome in EQR form, within limits from zero to one, cause that all the studied parameters, which are very diverse, must be conveyed to numerical form. The MHR method takes into account the above conditions and proposes a classification which includes limit values for five classes of status and four classes of ecological potential. It assumes limit values of classes lowering from natural watercourses through heavily modified to artificial.W pracy przedstawiono zasady i wyniki stosowanych dotychczas w Europie klasyfikacji stanu hydromorfologicznego cieków. Ramowa Dyrektywa Wodna wprowadziła obowiązek monitorowania elementów hydromorfologicznych rzek, do których zaliczono reżim hydrologiczny, ciągłość rzeki oraz morfologię koryta. Normy europejskie określają wymagane w takich badaniach nieco odmienne wskaźniki jakości i sposób ich oceny. Według klasyfikacji stanu i potencjału ekologicznego powinny być uwzględnione kategorie i typy rzek, natomiast według dotychczasowych metod nie ma takiego rozróżnienia. Ocena bardzo zróżnicowanych wskaźników i atrybutów oraz wymóg prezentowania wyniku w formie EQR w granicach od zera do jedności powoduje, że wszystkie badane parametry, które są bardzo zróżnicowane, muszą być doprowadzone do formy liczbowej. W metodzie MHR uwzględnia się powyższe uwarunkowania i proponuje klasyfikację, zawierającą wartości graniczne pięciu klas stanu oraz czterech klas potencjału ekologicznego. Zakłada się w niej, że wartości graniczne klas zmniejszają się od cieków naturalnych poprzez silnie zmienione do sztucznych
- …