Gas absorption towards the η Tel debris disc: winds or clouds?

η Telescopii is an ∼23 Myr old A-type star surrounded by an edge-on debris disc hypothesized to harbour gas. Recent analysis of far- and near-ultraviolet spectroscopic observations of η Tel found absorption features at ∼−23 and ∼−18 km s−1 in several atomic lines, attributed to circumstellar and interstellar gas, respectively. In this work, we put the circumstellar origin of the gas to a test by analysing high-resolution optical spectroscopy of η Tel and of three other stars with a similar line of sight as η Tel: HD 181327, HD 180575, and ρ Tel. We found absorption features at ∼−23 and ∼−18 km s−1 in the Ca II H&K lines, and at ∼−23 km s−1 in the Na I D1&D2 doublet in η Tel, in agreement with previous findings in the ultraviolet. However, we also found absorption features at ∼−23 km s−1 in the Ca II K lines of the three other stars analysed. This strongly implies that the absorption lines previously attributed to circumstellar gas are more likely due to an interstellar cloud traversing the line of sight of η Tel instead

Supplementary data for the article: Waisi, H.; Janković, B.; Nikolić, B.; Dragičević, V.; Panić, I.; Tosti, T.; Trifković, J. Influence of Various Concentrations of 24-Epibrassinolide on the Kinetic Parameters during Isothermal Dehydration of Two Maize Hybrids. South African Journal of Botany 2018, 119, 69–79. https://doi.org/10.1016/j.sajb.2018.08.006

Supplementary material for: [https://doi.org/10.1016/j.sajb.2018.08.006]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/342

Supplementary data for article : Panic, V. V.; Seslija, S. I.; Popovic, I. G.; Spasojevic, V. D.; Popovic, A. R.; Nikolic, V. B.; Spasojevic, P. M. Simple One-Pot Synthesis of Fully Biobased Unsaturated Polyester Resins Based on Itaconic Acid. Biomacromolecules 2017, 18 (12), 3881–3891. https://doi.org/10.1021/acs.biomac.7b00840

Supporting information for: [https://doi.org/10.1021/acs.biomac.7b00840]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2568]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3058

Adsorption of azo dyes on polymer materials

The use of polymeric adsorbents for the removal of azo dyes from solution has been reviewed. Adsorption techniques are widely used to remove certain classes of pollutants from waters, especially those which are not easily biodegradable. The removal of azo dyes as pollutants from wastewaters of textile, paper, printing, leather, pharmaceutical and other industries has been addressed by the researchers. The wider use of already available adsorbents is restricted due to their high costs which lead to investigation and development of new materials that can be cheaper, eficient and easy regenerated. The aim of this article is to present to the readers the widespread investigations in recent years of synthetic and natural polymers as adsorbents and potential replacement of conventional adsorbents. This review presents only the data obtained using raw, hydrogel, grafted and crosslinked forms of synthetic and nature based polymers, and the discussion is limited to these polymer-based materials and their adsorption properties

Exocometary gas structure, origin and physical properties around β Pictoris through ALMA CO multitransition observations

Recent ALMA observations unveiled the structure of CO gas in the 23 Myr-old $\beta$ Pictoris planetary system, a component that has been discovered in many similarly young debris disks. We here present ALMA CO J=2-1 observations, at an improved spectro-spatial resolution and sensitivity compared to previous CO J=3-2 observations. We find that 1) the CO clump is radially broad, favouring the resonant migration over the giant impact scenario for its dynamical origin, 2) the CO disk is vertically tilted compared to the main dust disk, at an angle consistent with the scattered light warp. We then use position-velocity diagrams to trace Keplerian radii in the orbital plane of the disk. Assuming a perfectly edge-on geometry, this shows a CO scale height increasing with radius as $R^{0.75}$, and an electron density (derived from CO line ratios through NLTE analysis) in agreement with thermodynamical models. Furthermore, we show how observations of optically thin line ratios can solve the primordial versus secondary origin dichotomy in gas-bearing debris disks. As shown for $\beta$ Pictoris, subthermal (NLTE) CO excitation is symptomatic of H$_2$ densities that are insufficient to shield CO from photodissociation over the system's lifetime. This means that replenishment from exocometary volatiles must be taking place, proving the secondary origin of the disk. In this scenario, assuming steady state production/destruction of CO gas, we derive the CO+CO$_2$ ice abundance by mass in $\beta$ Pic's exocomets to be at most $\sim$6%, consistent with comets in our own Solar System and in the coeval HD181327 system.LM acknowledges support by STFC and ESO through graduate studentships and, together with MCW and QK, by the European Union through ERC grant number 279973. Work of OP is funded by the Royal Society Dorothy Hodgkin Fellowship, and AMH gratefully acknowledges support from NSF grant AST-1412647.This is the final version of the article. It first appeared from Oxford University Press via https://doi.org/10.1093/mnras/stw241

Supplementary data for the article: Waisi, H.; Janković, B.; Nikolić, B.; Dragičević, V.; Panić, I.; Tosti, T.; Trifković, J. Influence of Various Concentrations of 24-Epibrassinolide on the Kinetic Parameters during Isothermal Dehydration of Two Maize Hybrids. South African Journal of Botany 2018, 119, 69–79. https://doi.org/10.1016/j.sajb.2018.08.006

Supplementary material for: [https://doi.org/10.1016/j.sajb.2018.08.006]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/342

Biohidrogelovi poli(metakrilne kiseline): bubrenje i kontrolisano otpuštanje kofeina

Modern society are faced with lot of challenges in the treatment of many diseases, especiallywith serious ones such as cancer. Safer and more efficient treatment of the cancer patients are maingoals which researchers are aiming. One of the good approaches can be drug delivery systems.Still, a lot of anticancer drugs are poorly water-soluble and their encapsulation and controlled releasecan be quite challenging. Present study is focused to improve drug delivery system based onhydrophilic poly(methacrylic acid) and amphiphilic casein with encapsulated poorly water-solublecaffeine, which has been developed through our previous research. The hydrogels with 1.6mol% ofcrosslinker and 100% of neutralization degree of methacrylic acid are synthetized (PMAC-100N-4M). The swelling process of the PMAC-100N-4M hydrogels and caffeine release are analyzed intwo environments which simulate human stomach and intestines. It is also investigated how thechange in the encapsulated caffeine weight and the addition of liposomes with encapsulated caffeine,affect swelling degree of the PMAC-100N-4M hydrogels and release of caffeine. The resultsshow that controlled release of caffeine is improved, therefore overall therapy can be enhanced.Savremeno društvo je suočeno sa mnogim izazovima u tretamanu raznih bolesti, naročito ozbiljnih oboljenja kao što je rak. Glavni ciljevi naučnika su da se postigne bezbednija i efikasnija terapija pacijenata koji se leče od raka. Jedan od dobrih načina da se to postigne su sistemi za dostavu lekova. Ipak, mnogi antikancerogeni lekovi su slabovodorastvorni, pa bi veliki izazov mogao da bude inakpsulacija i njihovo kontorlisano otpuštanje iz sistema za dostavu lekova. Cilj ovog rada je da se unapredi sistem za dostavu lekova na bazi hidrofilne poli(metakrilne kiseline) i amfifilnog kazeina sa inkapsuliarnim slabo vodorastvornim kofeinom, koji je razvijen tokom našeg prethodnog istraživanja. U ovom radu sintetisani su hidrogelovi sa 1,6mol% umreživača i 100% neutralisanom metakrilnom kiselinom (PMAC-100N-4M). Procesi bubrenja PMAC-100N-4M hidrogelova i kontrolisanog otpuštanja kofeina su ispitivani u dve sredine koje simuliraju želudac i tanko crevo čoveka. Takođe je ispitano kako promena količine inkapsuliranog kofeina i dodatak lipozomne suspenzije sa inkapsuliranim kofeinom utiče na procese bubrenja PMAC-100N-4M hidorgelova i otpuštanje kofeina. Rezultati pokazuju da je proces kontrolisanog otpuštanje kofeina unapređen, a samim tim je moguće unaprediti i celokupnu terapiju

Ultrazvučna ekstrakcija pektina iz otpadne jabučne kaše primenom eutektičkih rastvarača na bazi holin hlorida

Pectin and pectin derived oligosaccharides can be obtained from waste apple pomace(biomass). Traditional method for pectin extraction involves use of diluted mineral acids atelevated temperatures, with yields of about 10 to 15%. As an alternative to conventionalmethods, the use of eutectic solvents is increasing because of their superior propertieswhen it comes to targeted extraction of certain components from biomass. The aim of thispaper is ultrasound assisted extraction of pectin from waste apple pomace using cholinechloride based eutectic solvents and lactic acid. Properties of extracted products wereexamined using FTIR spectroscopy and differential scanning calorimetry.Pektin i pektinski oligosaharidi mogu se dobiti iz otpadne jabučne kaše. Ovaj prirodni polimer ima široku primenu u industriji. Tradicionalna metoda za ekstrakciju pektina podrazumeva tretman razblaženim mineralnim kiselinama na povišenoj temperaturi, pri čemu se prinosi ostvaruju od oko 10 do 15%. Kao alternativa tradicionalnim rastvaračima sve češće se koriste i eutektički rastvarači, koje odlikuju daleko superiornija svojstva kada je reč o ciljanoj ekstrakciji određenih komponenti iz biomase. Cilj ovog rada je ultrazvučna ekstrakcija pektina primenom eutektičkih rastvarača na bazi holin hlorida i mlečne kiseline. Svojstva ekstrahovanog proizvoda ispitana su primenom FTIR spektroskopije i diferencijalne skenirajuće kalorimetrije

Planet formation in intermediate-separation binary systems

ABSTRACT We report the first characterization of the individual discs in the intermediate-separation binary systems KK Oph and HD 144668 at millimetre wavelengths. In both systems, the circumprimary and the circumsecondary discs are detected in the millimetre continuum emission, but not in 13CO nor C18O lines. Even though the disc structure is only marginally resolved, we find indications of large-scale asymmetries in the outer regions of the primary discs, most likely due to perturbation by the companion. The derived dust masses are firmly above debris disc level for all stars. The primaries have about three times more dust in their discs than the secondaries. In the case of HD 144668, the opacity spectral index of the primary and secondary differ by a large margin of 0.69, which may be a consequence of the secondary disc being more compact. Upper limits on the gas masses imply less than 0.1 Mjup in any of these discs, meaning that giant planets can no longer form in them. Considering that there have been no massive gas discs identified to date in intermediate-separation binaries (i.e. binaries at a few hundred au separation), this opens space for speculation whether their binarity causes the removal of gas, with tidal interaction truncating the discs and hence shortening the accretion time-scale. More systematic studies in this respect are sorely needed.</jats:p

GASPS observations of Herbig Ae/Be stars with PACS/Herschel. The atomic and molecular content of their protoplanetary discs

We observed a sample of 20 representative Herbig Ae/Be stars and five A-type debris discs with PACS onboard of Herschel. The observations were done in spectroscopic mode, and cover far-IR lines of [OI], [CII], CO, CH+, H2O and OH. We have a [OI]63 micron detection rate of 100% for the Herbig Ae/Be and 0% for the debris discs. [OI]145 micron is only detected in 25%, CO J=18-17 in 45% (and less for higher J transitions) of the Herbig Ae/Be stars and for [CII] 157 micron, we often found spatially variable background contamination. We show the first detection of water in a Herbig Ae disc, HD 163296, which has a settled disc. Hydroxyl is detected as well in this disc. CH+, first seen in HD 100546, is now detected for the second time in a Herbig Ae star, HD 97048. We report fluxes for each line and use the observations as line diagnostics of the gas properties. Furthermore, we look for correlations between the strength of the emission lines and stellar or disc parameters, such as stellar luminosity, UV and X-ray flux, accretion rate, PAH band strength, and flaring. We find that the stellar UV flux is the dominant excitation mechanism of [OI]63 micron, with the highest line fluxes found in those objects with a large amount of flaring and greatest PAH strength. Neither the amount of accretion nor the X-ray luminosity has an influence on the line strength. We find correlations between the line flux of [OI]63 micron and [OI]145 micron, CO J = 18-17 and [OI]6300 \AA, and between the continuum flux at 63 micron and at 1.3 mm, while we find weak correlations between the line flux of [OI]63 micron and the PAH luminosity, the line flux of CO J = 3-2, the continuum flux at 63 micron, the stellar effective temperature and the Brgamma luminosity. (Abbreviated version)Comment: 20 pages, 29 figures, accepted by Astronomy and Astrophysic