The flux ratio of the [N II]λλ\lambda\lambda 6548, 6583 \AA\ lines in sample of Active Galactic Nuclei Type 2

In spectra of the Active Galactic Nuclei (AGNs), the [N II] 6548, 6583 A lines are commonly fitted using the fixed intensity ratio of these two lines (R[N II]=I$_{6583}$/I$_{6548}$). However, the used values for fixed intensity ratio are slightly different through literature. There are several theoretical calculations of the transition probabilities which can be used for the line ratio estimation, but there are no experimental measurements of this ratio, since the [N II] lines are extremely weak in laboratory plasma. Therefore, the intensity ratio of [N II] lines can be measured only in the spectra of astrophysical objects. However, precise and systematic measurements have not be done so far, because of difficulties in measurement of the [N II] ratio in various spectra (overlapping with H$\alpha$, weak intensity of [N II], influence of the continuum noise and outflow contribution, etc.). Here we present the measurements of the flux ratio of the [N II]$\lambda\lambda$ 6548, 6583 A emission lines for a sample of 250 Type 2 AGNs spectra taken form Sloan Digital Sky Survey (SDSS) data base. The spectra are chosen to have high signal-to-noise ratio and to [N II] and H$\alpha$ lines do not overlap. The obtained mean flux ratio from measurements is 3.049 $\pm$ 0.021. Our result is in agreement with theoretical result obtained by taking into account the relativistic corrections to the magnetic dipole operator.Comment: Accepted in Advances in Space Research, 8 pages, 4 figures, 1 tabl

Influence of the optical Fe II quasi-continuum on measuring the spectral parameters of active galactic nuclei

We explore the influence of optical Fe II quasi-continuum on the measured spectral parameters in the 4150-5500 A range for the spectra of Type 1 active galactic nuclei (AGNs). We assume that the broad line region is composed of two sub-regions: the very broad line region (VBLR) and the intermediate line region (ILR). We constructed a large set of synthetic AGN spectra by taking different portions of the VBLR and ILR contributions, where initially the VBLR and ILR model spectra were constructed on the basis of prototypes of two observed spectra with dominant VBLR (i.e. ILR) emission. To investigate the influence of the optical Fe II quasi-continuum on the AGN measured spectral parameters, we fit the power-law continuum and emission lines in a set of model spectra, as commonly done for observed AGN spectra. We then compared the spectral parameters obtained after the fitting procedure with those of the model. We find that the optical Fe II quasi-continuum can be very strong in the case of spectra with strong and very broad Fe II lines and it is difficult to fully separate it from the power-law continuum. This gives the effect of a slightly underestimated H$\beta$ width and underestimated fluxes of the H$\beta$ and Fe II lines, while the continuum flux is then slightly overestimated. The most affected spectral parameters are the line equivalent widths (EWs), especially EW Fe II, which may be strongly underestimated. We discuss the possible underlying physics in the quasar main sequence, as implied by the results of our spectral modelling. We find that the set of AGN model spectra assuming different ILR and VBLR contributions can aptly reproduce the quasar main sequence, that is, the full width at half maximum (FWHM) H$\beta$ versus Fe II/H$\beta$ anti-correlation, where both parameters in this anti-correlation are strongly dependent on the ILR and VBLR contribution rate.Comment: 12 pages, 15 figures, accepted in Astronomy & Astrophysic

Preliminary study of copper(II) ions removal from wastewater using solid residue obtained by co-pyrolysis of lignite and high density polyethylene mixture

In this study the solid residue obtained by the co-pyrolysis of low quality, mineral-rich lignite taken from the Kostolac Basin, Serbia (45.36% of ash; 33.42% of total organic carbon; net calorific value of 9.5 MJ/kg) and high density polyethylene, HDPE (mass ratio, 1:1) at 500 oC was tested as a sorbent for Cu2+ ions, considering that as a coaly-based material, simultaneously enriched in clays, it may have good adsorption properties. Sorption experiments of were performed using 0.5 g of solid co-pyrolysis lignite/HDPE product, as sorbent which was treated with 5 cm3 of model solutions containing ~ 200 times higher concentration of Cu2+ ions (242.60 mg/dm3), in relationship to its maximal allowed content in surface water of bad quality. Model solutions were prepared using corresponding nitrates dissolved in distilled water. Two model solutions were prepared. The first model solution contained individual Cu2+ ions, whereas the second one contained mixture of Cu2+, Pb2+, Co2+ and Cd2+ ions. Concentration of each ion in latter was also ~ 200 times higher than its maximal allowed content in surface water of bad quality. Treatment with distilled water was used as a blank. Concentrations of heavy metal ions in initial model solutions and supernatants obtained after sorption experiments were measured using inductively coupled plasma – optical emission spectrometry. The obtained results indicated very efficient sorption of Cu2+ ions from its individual model solution, attaining 99.96%. The efficiency of Cu2+ ions sorption was also high (99.95%) from model solution, which contained mixture of metal ions. It is important to mention that sorption of other metal ions from model solution mixture was also effective (99.99%, 80.70% and 71.04% for Pb2, Cd2+ and Co2+, respectively). The preliminary results showed promising sorption properties of solid residue obtained by the co-pyrolysis of lignite and HDPE against Cu2+, but also possibly for other heavy metals, particularly, Pb2+ ions.Abstracts and Field guides: [https://opac.geologie.ac.at/wwwopacx/wwwopac.ashx?command=getcontent&server=images&value=Pangeo_Austria_2022.pdf

Arsenic removal from aqueous solutions by sorption onto zirconium- and titanium-modified sorbents

Arsenic reduction in drinking water can include treatment by adsorption, switching to alternative water sources, or blending with water that has a lower arsenic concentration. Commercial sorbents MTM, Greensand and BIRM (Clack Corporation) were modified with zirconium and titanium after activation. The modifications were performed with titanium tetrachloride and zirconium tetrachloride. The modified sorbents were dried at different temperatures. The sorption of arsenate and arsenite dissolved in drinking water (200μg L-1) onto the sorbents were tested using a batch procedure. After removal of the sorbent, the concentration of arsenic was determined by HG-AAS. Zirconium-modified BIRM showed the best performance for the removal of both arsenite and arsenate. Modification of the greensand did not affect arsenic sorption ability. Zirconium-modified BIRM diminished the concentration of total As to below 5 μg L-1

Study of the Electrochemical Oxidation of Reactive Textile Dyes Using Platinum Electrode

Textile industries are widespread in developing countries. Among the various processes in the textile industry, the dyeing process uses large volumes of water for dyeing, fixing and washing. Textile industry wastewater is characterized by intensive color and high chemical oxygen demand (COD) concentrations that discarding of these toxic wastewaters to the environment will cause a major problem. In this study electrochemical oxidation of reactive textile dyes: Reactive Blue 52, Reactive Black 5, Reactive Green 15, and Reactive Yellow 125, using platinum anode was examined. Electrolysis is carried out in electrochemical cell containing membrane which is standard membrane in industry. Membrane separated anodic and cathodic area. Supporting electrolyte was 0.1M sodium sulfate which is also present in real textile effluents. Applied voltage of 6, 12 and 24V, and influence of membrane on electrolysis were examined on model dye (Reactive Blue 52). Highest degradation degree for model dye was achieved at 12V, so electrolysis of other dyes was done on this voltage. COD value of all dyes dropped after 60 minutes of electrolysis below a measurable level ( LT 30mg/L O-2), except Reactive Black 5 whose COD reduction was 57.95% with membrane and 35.28% without membrane applied. Complete decolorization was achieved after 10 to 60 minutes for all dyes. Degradation products of model dye Reactive Blue 52 were monitored with HPLC, and influence of pH on decolorization was also examined on model dye

Obrnuta proteza ramena: primjena i iskustvo u Hrvatskoj

Reverse shoulder prosthesis has become one of the most often used prosthetic implants in shoulder replacement surgery. It has a wide spectrum of indications, starting from comminuted humeral fractures and posttraumatic arthritis to arthritis caused by the rotator cuff loss. Its application at our hospital began in 2004, at first in few specific cases and with time in ever growing number of patients. Over 8 years, more than 250 reverse shoulder prostheses were implanted at our institution. In addition, our surgeons supervised its application in other hospitals all over Croatia. In the postoperative course, the shoulder was immobilized for 4-6 weeks with a thoracobrachial cast. After removal of the cast, physical therapy was initiated. The length of physical therapy program depended upon many factors. As a rule, immobilization lasted longer in patients that were operated on due to posttraumatic arthritis and those that suffered from deltoid muscle atrophy and shoulder contracture before surgery. Complications included dislocation of the prosthesis shortly after surgery (in the first four weeks) and infection. Infection was a special problem and treatment included even explantation of the prosthesis.Inverzna ili obrnuta proteza ramena je implantat koji se posljednjih godina sve češće ugrađuje na mjesto ramenog zgloba. Ima širok spektar indikacija, od višeivernih prijeloma humerusa, posttraumatskih artroza pa do artroza uzrokovanih gubitkom rotatorne manžete. U našoj Klinici ugrađuje se od 2004. godine, isprva sporadično, a potom sve više. Tijekom idućih 8 godina ugrađeno je preko 250 ovih proteza. U to nisu uključene proteze koje su ugrađene u drugim bolničkim ustanovama, ali pod vodstvom stručnjaka iz naše ustanove. U poslijeoperacijskom tijeku, prvih 4-6 tjedana, bolesnik je bio imobiliziran, najčešće torakobrahijalnim gipsom. Nakon skidanja imoblizacije uslijedila bi fizikalna terapija. Dužina fizikalna terapije ovisila je o mnogo čimbenika. U pravilu je duže trajala kod bolesnika koji su operirani zbog posttraumatske artroze i prijeoperacijski su imali atrofiju deltoidnog mišića i kontrakturu ramena. Od komplikacija treba spomenuti luksacije proteze u kratkom poslijeoperacijskom tijeku (prva 4 tjedna) i infekcije. Infekcija je osobit problem, a njezino liječenje uključuje i vađenje proteze

Study of the Electrochemical Oxidation of Reactive Textile Dyes Using Platinum Electrode

Textile industries are widespread in developing countries. Among the various processes in the textile industry, the dyeing process uses large volumes of water for dyeing, fixing and washing. Textile industry wastewater is characterized by intensive color and high chemical oxygen demand (COD) concentrations that discarding of these toxic wastewaters to the environment will cause a major problem. In this study electrochemical oxidation of reactive textile dyes: Reactive Blue 52, Reactive Black 5, Reactive Green 15, and Reactive Yellow 125, using platinum anode was examined. Electrolysis is carried out in electrochemical cell containing membrane which is standard membrane in industry. Membrane separated anodic and cathodic area. Supporting electrolyte was 0.1M sodium sulfate which is also present in real textile effluents. Applied voltage of 6, 12 and 24V, and influence of membrane on electrolysis were examined on model dye (Reactive Blue 52). Highest degradation degree for model dye was achieved at 12V, so electrolysis of other dyes was done on this voltage. COD value of all dyes dropped after 60 minutes of electrolysis below a measurable level ( LT 30mg/L O-2), except Reactive Black 5 whose COD reduction was 57.95% with membrane and 35.28% without membrane applied. Complete decolorization was achieved after 10 to 60 minutes for all dyes. Degradation products of model dye Reactive Blue 52 were monitored with HPLC, and influence of pH on decolorization was also examined on model dye

Synthesis, Characterization and Adsorptive Properties of Organobentonites

In this paper partial and complete substitution of cations in the interlayer region of clay with different amounts of two aliphatic ammonium cations was performed with aim of synthesis of organobentonites with multipurpose adsorption properties. Domestic clay from Bogovina was submitted according to a common procedure used for the obtention of organobentonite, which comprises the following steps: grinding, sieving, Na-exchange, cation exchange and drying. The samples were characterized by X-ray diffraction and infrared spectroscopy. The incorporation of surfactant molecules into smectite structure lead to constant increase of d(001) basal spacing. IR absorption bands assigned to methyl and methylene vibrations increased with the increase of surfactant/bentonite ratio and length of aliphatic chain in surfactant molecules. Adsorptive properties of the obtained materials were in accordance with their organophylicity: the adsorption of organic dye increased while the rate of removal of Pb2+ by adsorption decreased

Distribution of major and trace elements in the Kovin lignite (Serbia)

A geochemical and mineralogical study was performed on lignite samples from the Upper Miocene Kovin deposit, hosting three coal seams. The Kovin lignite is characterized by high moisture content, medium to high ash yield, medium to high sulphur content and a relatively low gross and net calorific value. The mineralogical composition, and major and trace element contents were determined by X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) analyses, and inductively coupled plasma optical emission spectrometry (ICP-OES). The most abundant minerals in all lignite samples from the three coal seams are clays (illite/smectite), silicates (quartz, plagioclase), sulphates (gypsum/anhydrite) and carbonate (calcite). The other iron-rich minerals are sulphides, oxides and hydroxides (pyrite, mag-netite, haematite, and limonite). In general, mineral matter in the matrix coal consists of illite/ smectite and quartz, while xylite-rich coals, apart from illite/smectite, have a higher content of sulphates and Fe-oxide/hydroxide minerals. The lignite from the Kovin deposit is enriched in As, Cd, Co, Cr, Cu, Ga, Li, Mn, Mo, Ni, Pb, V, Zn, Gd, Tb, Er and Lu in comparison with the Clarke values for brown coals. The statistical analysis of bulk compositional data shows inorganic affinity for the majority of the major and trace elements and possible association with pyrite, illite/ smectite and calcite

Tracing the outflow kinematics in Type 2 active galactic nuclei

We used a sample of 577 spectra of active galactic nuclei Type 1.8-2 (z < 0.25) taken from the Sloan Digital Sky Survey to trace the influence of the outflow kinematics on the profiles of different emission lines (Hβ, [O III], Hα, [N II], [S II]). All considered lines were fitted with two Gaussian components: one that fits the core of the line, and another that fits the wings. We provide a procedure for decomposition of the Hα+[N II] wavelength band for spectra where these lines overlap. The influence of the gravitational and non-gravitational kinematics on the line components is investigated by comparing the dispersions of the line components with stellar velocity dispersion. We find that wing components of all the considered emission lines have pure non-gravitational kinematics. The core components are consistent with gravitational kinematics for the Hα, [N II], and [S II] lines, while in the [O III] there is evidence for contribution from non-gravitational kinematics. We adopted the wing components as a proxy for the outflow contribution and investigated the outflow kinematics by analysing the correlations between the widths and shifts of the wing components of different lines. For this purpose, we used the subsets in which wing components are detected in both compared lines, and can be fitted independently. We find strong correlations between wing component shifts, as well as between wing component widths of all considered lines, with the exception of the Hβ wing component width. These correlations indicate that outflow dynamics systemically affect all emission lines in the spectrum. However, it reflects with a different strength in their profiles, which is observed as different widths of the wing components. This is investigated by comparison of the mean widths of the wing components in subsets where wing components are present in all lines. The strongest outflow signature is observed in the [O III] lines, which have the broadest wing components; weaker outflow signatures are found in Hα and [N II], and the weakest is found for [S II]. These results imply that the considered lines arise in different parts of an outflowing region