20 research outputs found

    Contemporary determinants of international relatioos

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    Z wprowadzenia: "Nauka o stosunkach międzynarodowych nie może się obejść bez systematyzowania i porządkowania omawianej przez siebie niezwykle szerokiej materii. Poszukując odpowiedzi na pytania związane z relacjami pomiędzy uczestnikami interakcji międzynarodowych, nie sposób nie dostrzegać czynników, jakie na nie wpływają, czy to w sposób pośredni czy też bezpośredni, zależny lub niezależny od nich. Wielość tych czynników i zmienność wagi przykładanej do poszczególnych, zależnie od epoki, stwarza konieczność gruntownego badania i wskazywania na najważniejsze z nich, decydujące w danym okresie."(...

    Demand in the sports market

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    Rozdział ma na celu przedstawienie strony popytowej rynku, ze specjalnym uwzględnieniem najważniejszego podmiotu konsumującego sport, jakim są osoby fizyczne. W szczególności zaprezentowane zostaną: wielkość wydatków na sport wg sektorów instytucjonalnych w Polsce, czynne uprawianie sportu (obraz aktywności fizycznej i wydatków na sport Polaków oraz model decyzyjny podejmowania i wyboru aktywności sportowej), bierne uprawianie sportu (zmienne determinujące oglądanie wydarzeń sportowych oraz obraz statystyczny tej aktywności w Polsce), metody badania popytu (wywiad z przedstawicielami agencji badawczej Pentagon Research)

    Zinc Sorption Studies on Pectin-Based Biosorbents

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    The previously-obtained and characterized hybrid pectin-based beads containing agar-agar and guar gum, as well as sole pectin beads (P, for comparison) were examined for zinc ions sorption and desorption properties. The sorption kinetics and equilibrium in the studied system was described by two kinetic models (pseudo-first- and pseudo-second-order) and two isotherms (Langmuir and Freundlich), respectively. The desorption kinetics and equilibrium was also investigated by applying various inorganic acids (nitric, hydrochloric, and sulfuric acid) of various concentrations. In the case of guar gum additive, no significant change in sorption capacity compared to sole pectin beads was observed (q: 37.0 ± 2.6 and 34.7 ± 2.0 mg/g, respectively). Addition of agar-agar significantly decreased the sorption capacity to 22.3 ± 1.0 mg/g, but stripping of zinc(II) ions from this biosorbent was complete even with very diluted acids (0.01 M). Total desorption of zinc from sole pectin and pectin-guar gum beads required acid solution of higher concentration (0.1 M). Sorption rates for all biosorbents are roughly the same and maximum sorption is achieved after 4–5 h. Obtained results and the advantage of our sorbent’s shape formation ability, make the pectin-based biosorbents interesting alternative for zinc(II) ions removal

    Solvent-Impregnated Sorbents for Tantalum from Niobium Separation Using a Fixed-Bed Column

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    Reactor-grade niobium steel is used as a construction material for nuclear reactors. In this case, the presence of tantalum, which is characterized by a 20 times higher active cross section for capturing thermal neutrons than the cross section of niobium (181Ta: 21.3 barn), cannot exceed 100 ppm. Analytical methods for quality and new separation method development control need very pure niobium matrices—niobium compounds with a low tantalum content, which are crucial for preparing matrix reference solutions or certified reference materials (CRMs). Therefore, in this paper, a new, efficient method for separating trace amounts of Ta(V) from Nb(V) using extraction chromatography with the use of sorbents impregnated with methyl isobutyl ketone MIBK solvent is proposed. Various types of MIBK-impregnated sorbents were used (AG® 1-X8 Anion Exchange Resin, AMBERLITE™ IRC120 Na Ion Exchange Resin, SERVACEL® Cellulose Anion Exchangers DEAE 52, active carbons of various grain size, carbonized blackcurrant pomace, carbonized chokeberry pomace, bentonite, and polyurethane foam in lumps). The highest tantalum removal efficiency was determined using active coal-based materials (>97%). The separation effectivity of tantalum from niobium was also determined in dynamic studies using a fixed-bed column with MIBK-impregnated active carbon. Solutions of various Nb:Ta weight ratios (1:1, 100:1, 1000:1) were used. The most impressive result was obtaining 70 mL of high purity niobium solution of tantalum content 0.027 ppm (in relation to Nb) with 88.4% yield of niobium from a solution of Nb:Ta, weight ratio 1000:1 (purge factor equaled 35,000). It proves the presented system to be applicable for preparation of pure niobium compounds with very low contents of tantalum

    Mało energochłonna utylizacja zasolonych wód kopalnianych w zintegrowanym systemie membranowo – wyparnym

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    Przedstawiono rozwiązanie, w którym woda zasolona poddawana jest wstępnemu uzdatnianiu metodą nanofiltracji (NF) a następnie zatężaniu metodą wyparną lub w zintegrowanym układzie elektrodializa – odwrócona osmoza i dalszemu odparowaniu z krystalizacją chlorku sodu. Na przykładzie solanki z KWK Budryk wykazano, że uzysk soli, dzięki samemu zastosowaniu nanofiltracji, można zwiększyć z obecnej wartości 72,01% do 87,35%, a po dalszym usprawnieniu, polegającym na oczyszczaniu chemicznym, do 91,11% a nawet 99,1%. Wstępne uzdatnianie solanki metodą nanofiltracji, prowadzone w sposób opracowany przez Autorów w warunkach dużego przesycenia siarczanem wapnia z częściową recyrkulacją retentatu i kontrolowaną krystalizacją gipsu, daje możliwość zastosowania mało energochłonnych rozwiązań zatężania solanki. Na przykładzie solanki Budryk wykazano, że zużycie energii w procesie jej utylizacji można zmniejszyć z obecnych 888,7 kWh/t soli do 433,7-451,2 kWh/t soli, w przypadku zatężania solanki mało energochłonną metodą wyparną lub do 396,8 kWh/t soli w przypadku zatężania solanki w zintegrowanym układzie: elektrodializa – odwrócona osmoza. Proponowane rozwiązanie ma zostać przebadane w instalacji pilotowej w ramach projektu NANOS, finansowanego w programie TANGO2

    Zinc Ion Removal on Hybrid Pectin-Based Beads Containing Modified Poly(Methyl Methacrylate) Waste

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    A new hybrid sorbent in the form of round beads containing modified poly(methyl methacrylate) (PMMA) waste immobilized in pectin and crosslinked with calcium ions was prepared. A previously obtained and characterized powdered poly(methyl methacrylate)–based sorbent was used. Batch and column studies on the new material’s sorption-desorption properties were performed. Two kinetic models (pseudo-first- and pseudo-second-order) and three isotherms (Langmuir, Langmuir bisite and Freundlich) were used to describe the results. Breakthrough and elution curves were also obtained. Nitric, hydrochloric, and sulfuric acid of various concentrations were used in the desorption studies. Higher sorption affinity of zinc(II) ions to hybrid sorbent than to pectin alone, reflected by higher values of the Langmuir and Freundlich model parameters, was observed. The maximum sorption capacities, calculated based on the best-fitted models, were 50.2 mg/g (Langmuir bisite) and 42.2 mg/g (Langmuir) for hybrid and only pectin beads, respectively. The stripping of Zn ions using 0.1 M solutions of mineral acids was similarly effective in the case of both sorbents. The mass balance calculated for the column studies showed about 100% recovery of zinc in a sorption-desorption cycle. By applying the hybrid sorbent under the studied conditions it is possible to purify Zn in water to the level permitted by law and concentrate Zn(II) ions by about 60 times

    A Method for Determination of Metals in Hybrid Metal Oxide/Metal-Carbon Nanotubes Catalysts

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    Carbon nanotubes (CNTs), due to their special structure and unique properties, are still one of the most interesting materials for scientists. Recently, carbon nanotubes were proposed as a new type of carbon support for catalysts. Fe, Pt, Ni, Co, and other metals anchored to CNTs are used in various reactions. Due to the fact that production processes are usually unpredictable and the total amount of metal/metal oxide deposited on the CNTs may only be estimated, the methods for examining the chemical composition are necessary. In this study, fast and simple inductively coupled plasma atomic emission spectrometry (ICP-AES) with slurry nebulization was proposed for metal content determination in hybrid CeZrO2/CNT, Ni-CeZrO2/CNT, and Ni/CNT materials. Slurries were prepared by 30 min ultrasonication of appropriate amount of investigated material in 1% Triton X-100 solution. Optimal range of slurry concentration and optimal RF plasma power were established (40–400 mg L−1, 1.2 kW, resp.). Obtained results proved that this method may be applied for determination of Ce, Zr, and Ni in hybrid CNT-based materials

    Long Term and Large-Scale Continuous Studies on Zinc(II) Sorption and Desorption on Hybrid Pectin-Guar Gum Biosorbent

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    Pectin-guar gum biosorbent was tested for zinc(II) ions removal in column process. Sorption–desorption experiments were performed in laboratory and at larger scale. The breakthrough and elution curves were obtained for various conditions. The Bed Depth Service Time model was tested for utility in data estimation. Possibility of sorbent reuse and its lifetime was examined in 20 repeated sorption–desorption cycles. Finally, tests were repeated for real wastewater from galvanizing plant, giving satisfactory results. The effectiveness of Zn(II) sorption happened to be dependent on process parameters; tests have proved that it increased with increasing bed height and with decreasing flow rate or grain size. For an initial zinc concentration of 30 mg/L, even 2096 mL of zinc solution could be purified in small scale experiment (2 g of fine grain sorbent and flow rate 60 mL/h) or 5900 L in large-scale (16 kg of large grain sorbent and flow rate 45 L/h). This allowed for 40-fold or 49-fold zinc increases in concentration in one sorption–desorption cycle. The most successful results are meant that at least 20 sorption–desorption cycles could be performed on one portion of biosorbent without loss of its effectiveness, large-scale tests for real wastewater from galvanizing plant gave satisfactory results, and that the form and mechanical stability of our sorbent is suitable for column usage with flow rates applicable in industry
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