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EN
In this study, NiAl-LDH was modified with hydrochar using the NiAl-Hydrochar composite coprecipitation method. Materials were characterized by XRD and FT-IR analysis. XRD diffractogram and FT-IR spectra show that the NiAl-Hydrochar composite material has the characteristics of the precursors. NiAl- Hydrochar composite materials have a large adsorption capacity to adsorb cationic dyes. The adsorption follows the Langmuir adsorption isotherm model with the maximum capacity (Qmax) of the NiAl-Hydrochar composite material reaching 256.410 mg/g for malachite green and the adsorption process takes place spontaneously and endothermically. The regeneration process of NiAl-Hydrochar composites was more stable and the decrease was not significant (>70%). The selectivity of the dye mixture showed that the adsorbent was more selective for malachite green dye compared to methylene blue and rhodamine-B.
PL
W artykule zbadano zagadnienie zwarcia w linii dwutorowej z nieselektywnym działaniem związanym z nastawami przekaźnika opartymi na niedokładnej/niewystarczającej znajomości impedancji linii. Analiza zwarcia oparta jest na zmierzonych impedancjach linii i symulacji/testach systemowych wykonywanych za pomocą oprogramowania RelaySimTest. Przyjęto i udokumentowano odpowiednią procedurę pomiaru impedancji linii w liniach dwutorowych w możliwie najmniej inwazyjny sposób.
EN
This paper investigates a double-circuit line fault with non-selective tripping caused by the parameterization of the relay based on inaccurate/insufficient knowledge of the line impedances. Analysis of the fault is based on the measured line impedances and the simulation/system-based testing using RelaySimTest. An appropriate procedure was adopted and documented to measure the line impedances of double-circuit lines in a minimally invasive manner.
3
Content available Optimization strategies of container terminals
EN
One of the main tasks of operational management of modern container terminals is effective utilization of existing technological resources. The search for possible variants of terminal activity optimization requires constant analysis of transport process technology and development of technical and technological approaches to increase the effectiveness of resources utilization. One of the possible solutions provided by terminal operational systems is the application of different strategies of container stack organization and container selectivity. At the same time, the complicated character of input and output container flow makes the effectiveness of these strategies doubtful. The paper states that this particular manner of container service is different from traditional ones, i.e. FIFO and FILO. As output container flow is randomly distributed the manner of container service can be considered as First In/Random Out. The paper also considers different strategies that are applied in practice and analyzes its influence on the productivity of handling equipment. The results of these strategies simulation modeling are represented. The results prove that no strategy can provide a productivity with theoretical selectivity; any strategy provides slowed intensity of operations. At the same time, it is proved that the only optimization strategy which increases the productivity of handling equipment is the organization of terminal activity whereby containers can be selected from the stack not in requirement sequence, but in order of its position in a stack.
EN
This work describes the preparation of functional polymers containing 2-mercapto-1-methylimidazole and guanylthiourea ligands from chemically modified vinylbenzyl chloride/divinylbenzene copolymer (VBC/DVB). The resins were used for the removal of Ag(I) from synthetic and real chloride solutions. The 2-mercapto-1-methylimidazole resin was highly selective towards Ag(I) in relation to Pb(II) from real chloride leaching solution. The resins were selective for Ag(I) from real chloride solution and they did not sorb chloride complexes of Co(II), Ni(II) and Zn(II). The sorption kinetic data were well fitted to the pseudo-first-order kinetic model. The degree of Ag(I) desorption was about 80% using 1% potassium cyanide solution in 0.5% hydrogen peroxide solution. Resins retain their capacity towards Ag(I) in five consecutive sorption/desorption cycles.
EN
Palladium immobilized in metal-organic frameworks (MOF) exhibit promising catalytic properties in hydrogenation of different unsaturated substrates. Due to the specific porous and crystalline structure MOFs can contribute in bonding and activation of organic substrates, increasing catalytic efficiency of Pd@MOF composites. The superior tunability of MOFs structures enables to design highly selective catalysts for hydrogenation of different substrates, such as olefins, esters, ketones, alcohols or alkynes. Due to the synergistic effects of palladium and MOF not only high activity but also high selectivity can be achieved. The article presents representative examples of MOF-based palladium catalysts for hydrogenation to illustrate perspectives, also technological, of their application.
PL
W artykule przedstawiono możliwości poprawy selektywności i szybkości wykrywania zwarć w sieciach przemysłowych z wewnętrzną generacją na przykładzie zastosowania sterownika polowego SIPROTEC 7SD82 firmy Siemens.
EN
The article presents the possibilities of improving the selectivity and speed of short circuits detection in industrial MV networks with an internal generation on the example of use of Siemens SIPROTEC 7SD82 bay control unit.
EN
Froth flotation is a dynamic multiphase process in which particulate matter is separated with the help of chemical reagents by gas bubbles immersed in water. The original flotation results are usually presented in the form of kinetic curves relating recovered particulate matter mass (yield ) or mass of a selected component (recovery ), both shortly denoted as y, versus process time t at different concentrations c (g/dm3) of the applied reagents. The kinetic curves can be modified into three: incentive (maximum yield or recovery ymax vs c), limits (ymax vs kinetic constant k or specific rate) and half-life of flotation (t1/2 vs c) curves. The original and modified curves can be normalized by taking into account either an external parameter such as molecular mass (MW), critical coalesce concentration (CCC), critical concentration at the minimum bubble velocity (CMV), dynamic foaming index (DFI), and many other parameters or an internal parameter such as time, concentration needed to achieve certain yield, recovery (y) or kinetic constant. Normalization leads to new flotation curves and provides additional useful information about flotation performance. Normalization can be fully effective, partial or ineffective. Normalization of the original flotation kinetic curves usually is ineffective. Also, normalization of the incentive curve with external parameters such as frother molecular mass, which changes reagent concentration from c (g/dm3) to C (mol/dm3), is also ineffective. Partially effective are normalizations with other external parameters such as CCC and CMV, usually within the same class of regents, for instance alcohols. Only DFI seems to be a universal external normalization parameter for flotation results because it provides fully effective normalization and thus predicts the flotation results. Limited data on DFI restrict a full verification of this hypothesis. Normalization of the modified flotation curves with internal parameters such as k50 (value of 1st order kinetic constant when recovery or yield is 50% after a given flotation time), Ct1/2 (frother concentration in mol/dm3 at which the flotation half-life has an arbitrarily chosen value) and cy75 (frother concentration in g/dm3 at which recovery or yield is 75% after a given flotation time) is a good base for practical classification of flotation reagents.
EN
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.
PL
Ołów jest jednym z głównych składników towarzyszących obecnych w polimetalicznych rudach miedzi z Monokliny Przedsudeckiej. Ruda wydobywana w rejonie kopalni Lubin obecnie charakteryzuje się stosunkiem zawartości Cu do Pb jak 2: 1, co oznacza, że jest to ruda miedziowo-ołowiowa. Nośnikami miedzi w tej rudzie są bornit, chalkopiryt i w mniejszym stopniu chalkozyn, a nośnikiem ołowiu jest galena. Technologia flotacji w ZWR Lubin ma charakter kolektywny. W układzie technologicznym tego zakładu skruszona nadawa rozdzielana jest na 2 strumienie: rudy łupkowo-węglanowej oraz piaskowcowej. W pracy porównano selektywność flotacyjnego wzbogacania w ołów w obu strumieniach rudy. Na podstawie krzywych wzbogacania stwierdzono, że w przypadku flotacji rudy piaskowcowej galena flotowała z wyższą selektywnością niż we flotacji rudy łupkowo-węglanowej. Stwierdzono, że koncentraty flotacji głównej frakcji piaskowcowej charakteryzują się zbliżoną zawartością ołowiu do zawartości tego metalu w koncentratach ostatecznych z ZWR Lubin. Pomimo wysokiej selektywności wzbogacania w ołów we flotacji głównej piasków, znacząca ilość tego metalu koncentruje się w układzie flotacji łupkowo-węglanowej. Analizy mineralogiczne wykazały, że galena charakteryzuje się nieznacznie drobniejszym uziarnieniem oraz znacząco wyższym stopniem uwolnienia we flotacji głównej piasków w porównaniu ze strumieniem flotacji głównej łupkowo-węglanowej.
XX
Lead is one of the main accompanying components of po/ymetal/ic copper ore from the Kupferschiefer deposit located in SW Poland. The ratio of copper-to-lead content in the ore mined in the Lubin area is 2:7, this means that it is a Cu-Pb ore. The main copper-bearing minerals in the ore are bornite, chalcopyrite, and to a lesser extent, cha/cocite, while galena is the main lead-bearing mineral. The flotation at Lubin Concentrator (KGHM Polska M/edz 5.AJ consists of two independent streams of ore processing, that is shale-dolomitic and sandstone circuits. In this work selectivity of lead-bearing minerals flotation in two circuits was compared. The comparison was based on upgrading curves. The results showed that flotation selectivity of galena in the concentrate of the sandstone circuit was higher than that in the shale-dolomitic stream, while the most of this mineral is processed in the shale-dolomitic circuit The content of lead in the concentrate of rougher flotation of sandstone circuit was similar to the content of lead in the final concentrate produced at Lubin Concentrator. Mineralogical analyses indicated that galena was finer and also better liberated in the sandstone circuit than in the shale-dolomite stream.
EN
The flotation behavior of hard-to-separate and high-ash fine coal was investigated using conventional flotation with constant power input. A new flotation process, based on energy input and distribution, was designed to lower the ash content of concentrate. The results obtained using Fourier transform infrared (FTIR) analysis show that the coal samples have good floatability because of many hydrophobic and few hydrophilic functional groups. Under a constant power input, a large number of ash-forming materials floated into a froth product at the start of flotation. Based on the Fuerstenau upgrading curves, it was determined that the 0.25-0.074 mm size fraction range showed the worst selectivity when compared with 0.50-0.25 mm and -0.074 mm size fractions. The desired concentrate with an ash content of 13.98%, 27.59% of ash recovery, and 80.01% combustible matter recovery could be obtained by transferring the excess energy of the flotation-conditioning stage to the pre-conditioning stage and increasing the power input step-by-step in the flotation-conditioning stage at equal total energy consumption.
EN
Accuracy of determination of different separation parameters and selectivity indicators depends on the error of chemical analysis of feed and separation products as well as experimental and approximation errors. In this paper different selectivity parameters were considered which formulae was based on the content of useful component in the feed, concentrate and tailing. It was shown that the impact of chemical analysis on the selectivity parameters was small and the error determined by means of partial derivative approach for a copper ore upgraded by flotation was negligible. Also experimental errors were found to be insignificant. The largest errors occurred for approximation of the upgrading data with inadequately selected selectivity indicators.
PL
Niektóre polimery, w tym polimery odpadowe, mogą być bardzo dobrymi prekursorami do otrzymywania porowatych węgli aktywnych. W pracy przedstawiono wyniki badania adsorpcji CO2 i N2 w przedziale temperatur od 0C do 60C pod ciśnieniem 0,005÷1,2 bar (w przypadku CO2) i 0,001÷1,2 bar (w przypadku N2) na jednym mezoporowatym i pięciu mikroporowatych węglach aktywnych otrzymanych z polimerów. Izotermy adsorpcji CO2 i N2 aproksymowano za pomocą równania wirialego i wyznaczono wartości jego współczynników. Na podstawie wartości pierwszego wirialnego współczynnika wyznaczono stałe Henry’go adsorpcji CO2 i N2 w przedziale temperatur od 0C do 60C, które następnie zastosowano do obliczenia selektywności adsorpcji CO2 względem N2 na badanych węglach. Stwierdzono, że wartości stałej Henry’ego adsorpcji CO2 były o rząd wielkości większe od wartości stałej Henry’ego adsorpcji N2. Duża wartość wyznaczonej na podstawie tych stałych selektywności adsorpcji CO2 w stosunku do N2 wskazuje na znacznie silniejsze oddziaływanie CO2 niż N2 z powierzchnią węgla aktywnego. Oznacza to, że badane nanoporowate materiały węglowe mogą być z powodzeniem stosowane do adsorpcji CO2, w tym także do adsorpcji CO2 ze strumienia gazów spalinowych zawierających między innymi azot.
EN
Some polymers, including waste polymers, are very good precursors for synthesis of porous carbons. Data for adsorption of CO2 and N2 at temperatures in the range from 0oC to 60oC and pressures ranging from 0.005 to 1.2 bar and 0.001 to 1.2 bar for CO2 and N2, respectively are presented for one ordered mesoporous and five microporous activated carbons obtained from polymers. Adsorption isotherms of CO2 and N2 were approximated by means of virial equation and used to determine its coefficients. The first virial coefficient was used to determine the Henry’s constants for CO2 and N2 adsorption at temperatures from 0oC to 60oC, then applied for calculation of adsorption selectivity of CO2 over N2 for the carbons studied. It was established that the value of Henry’s constant for CO2 adsorption is an order of a magnitude larger than the corresponding value of Henry’s constant for N2 adsorption. High adsorption selectivity value obtained on the basis of these constants for CO2 compared to N2 indicate much stronger interaction of CO2 with a carbon surface than that of N2. This would indicate that the nanoporous carbons under studies can be readily applied for adsorption of CO2, including CO2 adsorption from a stream of flue gas containing nitrogen.
PL
Badano równowagi fazowe w układach dwuskładnikowych związków zapachowych, takich jak ketony, kwasy, długołańcuchowe alkohole, alkany, 2-fenyloetanol z alkoholami i wodą oraz 2-fenyloetanol z cieczami jonowymi. Badano również układy trójskładnikowe {ciecz jonowa + 2-fenyloetanol + woda}.
EN
The phase equilibria in binary systems of fragrance materials such as ketones, acids, alakanols, alkanes, 2-phenylethanol with alcohols and water as well as 2-phenylethanol with ionic liquids were measured. The ternary systems (ionic liquid + 2-phenylethanol + water) were also studied.
PL
Przedstawiono sposób doboru zabezpieczeń prądowych w systemach zasilania gwarantowanego ze szczególnym zwróceniem uwagi na selektywność ich działania.
EN
The paper presents a method for selection of current protections in guaranteed power supply systems, special attention paid to their operational selectivity.
PL
Przedstawiono wyniki badań porównawczych oksyetylenowania alkoholu laurylowego frakcji C₁₂–C₁₄ z zastosowaniem homogenicznego katalizatora alkalicznego (NaOH) oraz heterogenicznego katalizatora typu dimetalocyjankowego (DMC). Przeprowadzono analizę aktywności katalitycznej oraz składu i wybranych właściwości uzyskanych produktów. Katalizator DMC charakteryzuje ponad 7-krotnie wyższa aktywność wyrażona jako jednostkowa szybkość przereagowania oksiranu, węższa dystrybucja homologów generowanych polidyspersyjnych produktów reakcji oraz większa selektywność w porównaniu z katalizatorem alaMexeo kalicznym. Oksyetylaty otrzymane z udziałem katalizatora DMC wykazują również względnie większe wartości stałej równowagi hydrofilowo-lipofilowej HLB. Stwierdzono pełną przydatność badanego katalizatora typu DMC do otrzymywania niejonowych surfaktantów typu oksyetylatów.
EN
C₁₂–C₁₄ fatty alcs. were ethoxylated with oxirane in presence of NaOH or a com. complex M¹x[M²(CN)₆]yL (M¹ = Zn²⁺, Fe²⁺ or Ni²⁺, M2 = Fe³⁺ or Co³⁺, L = H₂O, F⁻, Cl⁻, Br-, I-, alcs., glycols, ethers or polyethers) catalyst, to study the reaction kinetics and product properties (hydrophilic-lipophylic balance, chem. compn., PhOH index, cloud point). The complex catalyst was more active and selective than the NaOH catalyst.
EN
The selectivity behaviour of nuclear grade anion exchange resin Auchlite ARA-9366 in chloride form towards iodide and bromide ions in the solution was studied. The trend in selectivity of the resin was predicted on the basis of thermodynamics of Clˉ/Iˉ and Clˉ/Brˉ uni-univalent ion exchange reactions. It was observed that the equilibrium constants K values for Clˉ/Iˉ ion exchange reaction were higher than that calculated for Clˉ/Brˉ exchange under identical experimental conditions. Also the enthalpy values for the two uni-univalent ion exchange reactions were calculated as -47.87 and -36.14 kJ/mol respectively. The high K and low enthalpy values obtained for Clˉ/Iˉ ion exchange reaction as compared to that obtained during Clˉ/Brˉ exchange supports higher selectivity of the resin towards iodide ions as compared to that towards bromide ions, when both the ions are present in the same solution.
EN
The thermodynamic approach was applied to predict the trend selectivity of industrial grade anion exchange resin Auchlite A-378 in chloride form towards iodide and bromide ions in the solution. The study was conducted by performing the Clˉ/Iˉ and Clˉ/Brˉ uni-univalent ion exchange reactions under gradually increasing temperature conditions. The thermodynamic equilibrium constants K values were used to calculate the enthalpies of the two uni-univalent ion exchange reactions. It was observed that the K values for Clˉ/Iˉ ion exchange reaction were higher than Clˉ/Brˉ exchange reaction under identical experimental conditions. Also the enthalpy values for the two uni-univalent ion exchange reactions were calculated as -39.51 and -18.38 kJ/mol respectively. The high K and low enthalpy values obtained for Clˉ/Iˉ ion exchange reaction is responsible for higher selectivity of the resin towards iodide ions as compared to that towards bromide ions, when both the ions are present in the same solution.
EN
Analyze of chromium(III) transport process from mixtures of Cr(III)/Cr(VI) ions with polymer inclusion membrane (PIM) system have been done. Di(2-ethylhexyl) phosphoric acid (D2EHPA) have been used as a carrier. It was found that the transport efficiency in PIM is dependent on the carrier concentration in the membrane. It was found that there is an optimal range of carrier concentration in the membrane, which ensures rapid and efficient transport. In studied system optimal D2EHPA concentration was in range between 0,9- 1,5 mol/dm3. Membrane worked as selective barrier for Cr(VI) ions. However increase of Cr(VI) concentration above 0,0005 mol/dm3 negatively influenced Cr(III) transport. It was caused by degradation of the polymer inclusion membrane made of cellulose triacetate (CTA) . Strongly oxidizing Cr(VI) ions can damage polymer inclusion membrane with CTA matrix. The chemical attack of strongly oxidant Cr(VI) ions could lead either to hydrolysis of the pendant acetyl group or to oxidation of polymer backbone leading to chain scission. Moreover, oxidation is accelerated at high concentration of Cr(VI) ions. The membrane containing D2EHPA as a carrier can be recommended for selective separation of Cr(III) ions only from diluted Cr(VI)/Cr(III) mixtures. However the polymer inclusion membrane need a change the polymer matrix.
EN
Iron ores located in the Alswaween area (Saudi Arabia) are of finely disseminated nature. They require ultrafine grinding for considerable degree of liberation. In this paper, different upgrading tech-niques were tried for their processing. The applied upgrading techniques included selective flocculation and column flotation as recent efficient technologies in fines upgrading. Each technique was investigated and optimized separately. Results showed that neither selective flocculation nor column flotation can be successfully used alone to produce high quality iron concentrate especially when using iron ore of size fraction 100% -0.075 mm. The best quality concentrate was found to have 55% Fe and 57% Fe when applying selective flocculation and column flotation, respectively at their optimum operating conditions. Meanwhile, the previously obtained results can be significantly improved when grinding the ore below 45 μm and applying selective flocculation as cleaning step for the concentrate obtained from the column flotation. Thus, it is possible to obtain concentrate having iron content of 63.55% Fe with 52.3% yield, which means an iron recovery in concentrate of ~80%.
EN
It was shown in the paper that kinetic equations relating recoveries of two components in separation products and time, when combined together to eliminate the time parameter, provide mathematical equations which relate recoveries of the two considered components in concentrate. The obtained one-adjustable-parameter type equations are very useful for approximation of the separation results plotted as the so-called Fuerstenau upgrading curves. Most empirical mathematical formulas presently used for the Fuerstenau plots were derived using various kinetic equations while some are still awaiting for their kinetic derivation.
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