Neškodljivost kalupnih pjesaka sa bentonitom i svijetlećim nositeljima ugljika

Procedures have been developed to determine the volume, rate and composition (particularly BTEX: benzene, toluene, ethylbenzene and xylenes and PAHs (polycyclic aromatic hydrocarbons)) of gas evolution from moulds and cores prepared with various binders as a means of harmfulness of moulding sands. The rate of gas evolution from green sands with four different lustrous carbon carrier and BTEX content were determined. The gas evolution rates are highest in the range of about 20 to 30 s after contact with molten metal. In practice during the first 200-250 s the total emission of gases generated in investigated samples occurred. The main emitted component from the BTEX group was benzene.Postupci su razvijeni za određivanje volumena, brzine i sastava (posebice BTEX: benzen, toluen, etilbenzen, xilana) i PAH (policiklički automatski hidrokarbonati) plina koji nastaje iz kalupa i jezgri na različitim nosačima u težnji za neškodljivost kalupnih pijesaka. Brzine nastajanja plina iz pripravljenih pijesaka sa 4 različita svijetleća nositelja ugljika i sadržajem BTEX su određeni. Brzine nastajanja plina su najveće u razini 20 do 30 s poslije dodira sa rastopljenim metalom. Praktično, tijekom prvih 200-250 s ostvaruje se ukupna emisija stvorenih plinova u istraživanim uzorcima. Iz BTEX skupine, benzen je glavna emitirajuća komponenta

Spectra disentangling applied to the Hyades binary Theta^2 Tau AB: new orbit, orbital parallax and component properties

Theta^2 Tauri is a detached and single-lined interferometric-spectroscopic binary as well as the most massive binary system of the Hyades cluster. The system revolves in an eccentric orbit with a periodicity of 140.7 days. The secondary has a similar temperature but is less evolved and fainter than the primary. It is also rotating more rapidly. Since the composite spectra are heavily blended, the direct extraction of radial velocities over the orbit of component B was hitherto unsuccessful. Using high-resolution spectroscopic data recently obtained with the Elodie (OHP, France) and Hermes (ORM, La Palma, Spain) spectrographs, and applying a spectra disentangling algorithm to three independent data sets including spectra from the Oak Ridge Observatory (USA), we derived an improved spectroscopic orbit and refined the solution by performing a combined astrometric-spectroscopic analysis based on the new spectroscopy and the long-baseline data from the Mark III optical interferometer. As a result, the velocity amplitude of the fainter component is obtained in a direct and objective way. Major progress based on this new determination includes an improved computation of the orbital parallax. Our mass ratio is in good agreement with the older estimates of Peterson et al. (1991, 1993), but the mass of the primary is 15-25% higher than the more recent estimates by Torres et al. (1997) and Armstrong et al. (2006). Due to the strategic position of the components in the turnoff region of the cluster, these new determinations imply stricter constraints for the age and the metallicity of the Hyades cluster. The location of component B can be explained by current evolutionary models, but the location of the more evolved component A is not trivially explained and requires a detailed abundance analysis of its disentangled spectrum.Comment: in press, 13 pages, 10 Postscript figures, 5 tables. Table~4 is available as online material. Keywords: astrometry - techniques: high angular resolution - stars: binaries: visual - stars: binaries: spectroscopic - stars: fundamental parameter

Threat-sensitive anti-predator defence in precocial wader, the northern lapwing Vanellus vanellus

Birds exhibit various forms of anti-predator behaviours to avoid reproductive failure, with mobbing—observation, approach and usually harassment of a predator—being one of the most commonly observed. Here, we investigate patterns of temporal variation in the mobbing response exhibited by a precocial species, the northern lapwing (Vanellus vanellus). We test whether brood age and self-reliance, or the perceived risk posed by various predators, affect mobbing response of lapwings. We quantified aggressive interactions between lapwings and their natural avian predators and used generalized additive models to test how timing and predator species identity are related to the mobbing response of lapwings. Lapwings diversified mobbing response within the breeding season and depending on predator species. Raven Corvus corax, hooded crow Corvus cornix and harriers evoked the strongest response, while common buzzard Buteo buteo, white stork Ciconia ciconia, black-headed gull Chroicocephalus ridibundus and rook Corvus frugilegus were less frequently attacked. Lapwings increased their mobbing response against raven, common buzzard, white stork and rook throughout the breeding season, while defence against hooded crow, harriers and black-headed gull did not exhibit clear temporal patterns. Mobbing behaviour of lapwings apparently constitutes a flexible anti-predator strategy. The anti-predator response depends on predator species, which may suggest that lapwings distinguish between predator types and match mobbing response to the perceived hazard at different stages of the breeding cycle. We conclude that a single species may exhibit various patterns of temporal variation in anti-predator defence, which may correspond with various hypotheses derived from parental investment theory

Expansion of Nature Conservation Areas: Problems with Natura 2000 Implementation in Poland?

In spite of widespread support from most member countries’ societies for European Union policy, including support for the sustainable development idea, in many EU countries the levels of acceptance of new environmental protection programmes have been and, in particular in new member states, still are considerably low. The experience of the countries which were the first to implement union directives show that they cannot be effectively applied without widespread public participation. The goal of this study was, using the example of Poland, to assess public acceptance of the expansion of nature conservation in the context of sustainable development principles and to discover whether existing nature governance should be modified when establishing new protected areas. The increase in protected areas in Poland has become a hotbed of numerous conflicts. In spite of the generally favourable attitudes to nature which Polish people generally have, Natura 2000 is perceived as an unnecessary additional conservation tool. Both local authorities and communities residing in the Natura areas think that the programme is a hindrance, rather than a help in the economic development of municipalities or regions, as was initially supposed. This lack of acceptance results from many factors, mainly social, historic and economic. The implications of these findings for current approach to the nature governance in Poland are discussed

Wykorzystanie spektrofotometrii do oznaczania zawartości montmorillonitu w masach formierskich z bentonitem

The theoretical bases of spectrophotometry used in analysis are discussed in the paper as well as the results of investigations of the montmorillonite content by means of the spectrophotometric adsorption of the Cu(II)-triethylenetetramine (Cu-TET) complex are presented. Bentonites originated from various producers (Sud Chemie, ZGM Zębiec S.A,) as well as samples of model moulding sands bonded by these bentonites were inwestigated in respect of their montmorillonite content. The montmorillonite content was measured in samples being at a room temperature and at temperatures of 400 °C and 700 °C. It was indicated, that the determined montmorillonite content in bentonite for the bentonites under investigation and for the model moulding sands with bentonites, are comparable, which proves that the quartz matrix, does not disrupt the measuring methodology and the applied spectrophotometric method is suitable for the moulding sands. It was found that at a temperature of 700 °C montmorillonite undergoes deactivation in the tested bentonites.W publikacji omówiono podstawy teoretyczne spektrofotometrii wykorzystywanej w analityce chemicznej oraz przedstawiono wyniki badań zawartości montmorillonitu metodą spektrofotometryczną adsorpcji kompleksu Cu(II)-trietylenotetraminy (Cu-TET). Zbadano bentonity pochodzące od różnych producentów (Sud-Chemie, ZGM Zębiec S.A.) oraz próbki modelowych mas formierskich wiązanych tymi bentonitami pod względem ich zawartości montmorillonitu. Zawartość montmorillonitu mierzono w próbkach w temperaturze pokojowej oraz w próbkach wygrzewanych w temperaturze 400 °C i 700 °C. Wykazano, że wyznaczone zawartości montmorillonitu w bentonicie dla rozpatrywanych bentonitów i mas modelowych z ich udziałem są porównywalne, co świadczy o tym, że osnowa kwarcowa, nie zakłóca metodyki pomiarowej, a stosowana metoda spektrofotometryczna nadaje się do wykorzystania w odniesieniu do mas formierskich. Stwierdzono, że w temperaturze 700 °C następuje dezaktywacja montmorillonitu w badanych bentonitach

Wpływ wsiewek miedzyplonowych na zawartość azotu mineralnego oznaczonego w glebie jesienią i wiosną w konwencjonalnym i ekologicznym systemie produkcji

The aim of researches was to determine the influence of undersown crops plowed down in the autumn and left till spring in the form of mulch on mineral nitrogen content in the soil profile determined in autumn and in spring in conventional and organic farming systems. The field experiments were conducted at the Zawady Experimental Farm owned by the University of Natural Sciences and Humanities in Siedlce. The following treatments were examined: factor 1 – Undersown crop: control object (no undersown crop cultivation), an undersown crop – biomass ploughed down in autumn (white melilot, white melilot + westerwold ryegrass, westerwold ryegrass), an undersown crop with its biomass used as a spring-incorporated mulch (white melilot, white melilot + westerwold ryegrass, westerwold ryegrass). factor 2 – farming system: conventional and organic. Ammonium and nitrate nitrogen contents were determined in two soil layers (0–30 and 31–60 cm) twice, ie in autumn and spring. The results showed that the highest soil concentrations of ammonium and nitrate ions were determined on control object, and in spring following white melilot incorporation. The autumn and spring-determined soil contents of mineral nitrogen were significantly higher in the conventional in comparison with organic farming system. Mulching of the soil surface with undersown crops significantly reduced the mineral nitrogen content in soil in spring compared with the autumn-incorporated undersown crops.Celem przeprowadzonych badań było określenie wpływu wsiewek międzyplonowych przyoranych jesienią i pozostawionych do wiosny w formie mulczu na zawartość mineralnych form azotu oznaczonego w profilu glebowym jesienią i wiosną w konwencjonalnym i ekologicznym systemie produkcji. Badania polowe przeprowadzono w RSD w Zawadach należącej do Uniwersytetu Przyrodniczo-Humanistycznego w Siedlcach. W doświadczeniu badano dwa czynniki. I. Wsiewka międzyplonowa: obiekt kontrolny (bez uprawy wsiewki międzyplonowej), wsiewka międzyplonowa - biomasa przyorana jesienią (nostrzyk biały, nostrzyk biały + życica westerwoldzka, życica westerwoldzka), wsieka międzyplonowa - biomasa pozostawiona do wiosny w formie mulczu (nostrzyk biały, nostrzyk biały + życica westerwoldzka, życica westerwoldzka). II. System produkcji: konwencjonalny, ekologiczny. Zawartość jonów amonowych i azotanowych oznaczono dwukrotnie, tj. jesienią i wiosną, w dwóch warstwach gleby (0-30 i 31-60 cm). Otrzymane wyniki badań pozwalają stwierdzić, że jesienią najwyższą zawartość mineralnych form azotu odnotowano na obiekcie kontrolnym, a wiosną po przyoraniu nostrzyku białego. W konwencjonalnym systemie produkcji zawartość azotu mineralnego oznaczonego w glebie zarówno jesienią, jak i wiosną była istotnie wyższa niż w ekologicznym systemie produkcji. Wsiewki międzyplonowe pozostawione do wiosny w formie mulczu spowodowały zmniejszenie zawartości azotu mineralnego w glebie wiosną w porównaniu do wsiewek międzyplonowych przyoranych jesienią

Wpływ międzyplonów na zawartość azotu mineralnego w glebie jesienią i wiosną

The aim of the present research was to determine the influence of undersown crops and stubble crops on the content of mineral forms of nitrogen in soil profile in autumn and spring. Field experiments were carried out at the Experimental Farm in Zawady, owned by the University of Podlasie in Siedlce. The following combinations of intercrops were taken into account: control object (without intercrop), undersown crops - biomass plowed down in autumn (white clover, Italian ryegrass), stubble crop - oiomass plowed down in autumn (oil radish), stubble crop - biomass left in the form of mulch (oil radish) till spring. The content of nitrate and ammonia ions were determined twice, ie in autumn and spring, in two layers of soil (0-30 and 31-60 cm). The results pointed out that, putting the intercrops into the cultivation limited the conrent of mineral nitrogen in soil in autumn, and increased in spring. The highest concentration of nitrate and ammonia ions was noted in soil in spring, when white clover was plowed down. When the surface of soil was mulched with stubble crop from white mustard in the time of winter, it decreased the content of mineral nitrogen in spring.Celem przeprowadzonych badań było określenie wpływu wsiewek miedzyplonowych i międzyplonów ścierniskowych na zawartość mineralnych form azotu oznaczonego w profilu glebowym jesienią i wiosną. Badania polowe przeprowadzono w RSD w Zawadach należącej do Akademii Podlaskiej w Siedlcach, W doświadczeniu badano następujące kombinacje międzyplonów. obiekt kontrolny (bez międzyplonu), wsiewka międzyplonowa - biomasa przyorana jesienią (koniczyna biała, życica wielokwiatowa), międzyplon ścierniskowy - biomasa przyorana jesienią (rzodkiew oleista), międzyplon ścierniskowy - biomasa pozostawioną do wiosny w formie mulczu (rzodkiew oleista). Zawartość jonów amonowych i azotanowychl oznaczono dwukrotnie, tj. jesienią i wiosną, w dwóch warstwach gleby (0-30 i 31-60 cm). Otrzymane wyniki pozwalają stwierdzić, iż wprowadzenie do uprawy miedzyplonów zmniejszało zawartość azotu mineralnego w glebie jesienią, a zwiększało wiosną. Największe stężenie jonów amonowych i azotanowych odnotowani w glebie wiosną, po przyoraniu koniczyny białej. Mulczowanie powierzchni gleby w okresie zimy międzyplonem ścierniskowym z rzodkwi oleistej zmniejszało zawartość azotu mineralnego wiosną