Wyniki wyszukiwania - Biblioteka Nauki

1

Qualitative and quantitative analysis of polyphenolic compounds in Ilex Sp.

100%

Zwyrzykowska A. , Kupczyński R. , Jarosz B. , Szumny A. , Kucharska A. Z.

Open Chemistry

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2015

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tom 13

|

nr 1

EN

Natural compounds are an important source of desired biological activity which help to improve nutritional status, enhance productivity and bring many health benefits. The leaves of the Ilex paraguariensis (Aquifoliaceae) are used for preparing a beverage known as yerba mate and represent a proven source of natural polyphenols which are known to foster biological activity with the emphasis on antioxidant properties. In present work we focused on the polyphenolic content of air-dried leaves of Ilex aquifolium L., Ilex aquifolium ‘Argentea Mariginata’, Ilex meserveae ‘Blue Angel’, and a commercially available mate as the reference product. Liquid chromatography combined with mass spectrometry (HPLC and LC-MS) and thin layer chromatography (TLC), were used to establish polyphenolic substances content in aqueous methanolic extracts obtained from the biological matter. Up to 20 polyphenolic compounds were identified in the extracts, including rutin, quinic acid and its caffeoyl esters, i.e. chlorogenic acid and its isomers as well as dicaffeoyl derivatives. We took chlorogenic acid and rutin as reference compounds to quantify their levels in the extracts. It was determined that in all tested plants, high levels of these antioxidants were present. This led us to the conclusion that their leaves might serve as valuable food additives.

2

The IBA self-extracting cyclotron project

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Kleeven W. , Lucas S. , Delvaux J. , Swoboda F. , Zaremba S. , Beeckman W. , Vandeplassche D. , Abs M.

Nukleonika

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2003

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tom Vol. 48,suppl.2

59-67

EN

The self-extracting cyclotron is a high-intensity 14 MeV H+ machine for isotope production. There is no electrostatic deflector. Extraction is achieved with a special shaping of the magnetic field. There are two long poles and two short poles, both with an elliptical gap profile; this provides a steep fall off of the magnetic field at the pole radii. An extraction groove is machined in the iron of one of the longer poles. First harmonic coils create a large orbit separation at the entrance of the extraction path and extract the beam. The machine is presently installed in the industrial isotope production site where the final commissioning and tests took place. Beams of more than 1.5 mA have been extracted and transported. Further development is ongoing in order to increase the current on target to at least 2 mA in the coming months. Commercial isotope production will start in the course of this year. The concept of the machine is explained and the layout of the machine and beam lines is presented. Results of orbit calculations and central region optimizations are given. Results of the measurement of extracted beam shapes and emittances are given. The progress and present status of the project are discussed.

3

Pozyskiwanie kobaltu(II) z krajowych surowców metodami ekstrakcyjnymi

100%

Gotfryd L.

Przemysł Chemiczny

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2006

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tom T. 85, nr 8-9

810-813

PL

Produkt uboczny polskich elektrorafinerii miedzi, surowy siarczan niklu (SSN) zawiera 25– 30% Ni, ok. 0,5% Co i inne typowe zanieczyszczenia (Zn, Cu, Mg, Fe). Można wskazać dwie główne drogi jego oczyszczania: poprzez usunięcie wszystkich istotnych zanieczyszczeń i dalszą obróbkę zawierającego nikiel(II) rafinatu lub poprzez sekwencyjne oczyszczanie roztworu SSN, z ekstrakcją i reekstrakcją niklu(II) jako ostatecznymi procesami jego oczyszczania i koncentracji. Zastosowanie ekstrakcji rozpuszczalnikowej Cyanexem 272 umożliwia pozyskanie z SSN czystego siarczanu niklu(II) (% wag., 22,3 Ni; 0,08 Ca; 0,03 Mg; 0,026 Na; poniżej: 0,001 Zn; 0,002 Co i 0,0025 Cu, Fe i Pb) oraz koncentratu Co(II). Inny proces, z udziałem ekstrahenta hydroksyoksymowego, prowadzi do podobnych rezultatów, ale jest bardziej pracochłonny ze względu na skomplikowany sposób usuwania kobaltu(II).

EN

Three major steps in processing of a decopperized crude NiSO4 soln.: (i) removal of most H2SO4, (ii) removal of As and/ or change of reaction medium, and (iii) recovery of Co(II) and Ni(II), were studied, each by several ways, viz., (i) extn. of H2SO4 and As with TBP and Cyanex 923; neutralization with calcined MgO; selective prepn. of gypsum; (ii) neutralization with lime or basic Ni (II) carbonate; or with NH4OH or with (Na/K) (OH/CO3); prepn. of Ni(II), Co(II) amino complexes; (iii) removing Fe(II/III), Mn(II/IV), As(III/V), Zn(II), and Cu(II); sepn. of Co(II) by oxidn. with (NH4)S2O8 and pptn.; removing major impurities by ion-exchange resins; cementation of Cu with Zn; extn. of Zn, Cu, Co with di(2,4,4-trimethylpentyl)phosphinic acid. A crude NiSO4 soln. contg. Ni 25–30, Co ~0.5%, and Zn, Cu, Mg, and Fe impurities, extd. with di(2,4,4trimethylpentyl) phosphinic acid, gave a Co(II) conc. and a pure NiSO4 contg. Ni 22.3%, Zn < 10, Cu < 20, Cu + Fe + Pb < 25, Na 260, Mg 300, and Ca 800 ppm.

4

Removal of lindane from wastewater using liquid-liquid extraction process

100%

Patil I. D. , Patil Y. S. , Pangarkar B. L.

Polish Journal of Chemical Technology

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2013

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tom 15

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nr 3

81-84

EN

Pesticide pollution is a serious problem being faced. Harmful levels of pesticides are found in the water which is used for daily purposes. In the event of such a scenario, this paper presents a working solution for bringing down the Pesticide levels in the water to safe levels by using the method of liquid-liquid extraction. The experimental liquid-liquid equilibrium data on pesticide-water-solvent ternary mixtures at a temperature of 288.15 K are presented here. The pesticide used here is a chlorinated hydrocarbon called lindane found in the water (underground, land), beverages and foods. The solvents used are Petro-ether-Chloroform (1:1), Ethylene di chloride and n-hexane. The equilibrium generation diagram, triangular diagram, tie lines and bimodal curves as well as the distribution coefficient have been determined and reported. The petro-ether-chloroform was found to be the right solvent for the separation of lindane from wastewater because of high selectivity (25.36) and distribution coefficient (4). The extraction process is simulated into ‘C’ language

5

Bioługowanie metali ciężkich z odpadów pogalwanicznych przy neutralnym pH środowiska, w obecności bakterii produkujących biosurfaktanty

100%

Karwowska E. , Andrzejewska-Morzuch D.

Rocznik Ochrona Środowiska

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2012

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tom Tom 14

597--606

EN

Precipitates and sludges from the galvanic industry are one of the sources of the environment contamination with heavy metals. Therefore, the investigations are carried out in order to developer the effective method of metals elimination from these wastes. The promising results are obtained in case of the application of microbial leaching. Up to now results concerned mainly the metals bioleaching in acidic environment. In this research work the possibility of heavy metals removal from galvanic wastes using the culture of sulphur oxidizing bacteria (pH 2-4) and a mixed culture of both sulphur oxidizing bacteria and biosurfactant producing bacteria (pH 6.5-8) was examined. It allowed to compare the process effectiveness in acidic and neutral environment. The cultures were prepared based on the activated sludge from the municipal wastewater treatment plant. The presence of sulphur oxidizing bacteria Acidithiobacillus ferrooxidans was confirmed using the PCR method. Bacillus subtilis and B. cereus strains were applied as biosurfactant producers. Three galvanic wastes, different in grain size, water content and heavy metal concentration, were bioleached. The research revealed that the metal release from galvanic wastes was more effective in presence of biosurfactant, especially in case of copper, but also for cadmium and chromium. The process effectiveness in acidic condition was comparatively lower. Zinc was the only metal that was bioleached faster in acidic environment, with similar final metal removal after 25 days of the process. The maximum values of metals elimination in the presence of biosurfactant depended on the bioleached waste type and were: 7.1-100% for copper, 3.7-50.3% for zinc, 30-50.5% for chromium, 34.1-71.9% for cadmium. The effectiveness of the nickel and lead removal was lower than 5%. The prolongation of the bioleaching period up to 40 days in case of waste C (the less susceptible to the bioleaching) resulted in elimination of 67.9% of Cu, 34.7% of Zn, 100% of Cr and 39.1% of Pb, while the effectiveness of nickel removal was still very low.

6

Extraction process and method validation for bioactive compounds from Citrus reticulata cv. Chachiensis : application of response surface methodology and HPLC–DAD

100%

Mei Z. , Zhang R. , Zhao Z. , Zheng G. , Xu X. , Yang D.

Acta Chromatographica

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2021

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tom Vol. 33, no. 3

270--280

EN

Citrus reticulata cv. Chachiensis, a traditional Chinese herb, has extensive medicinal and edible effects. 3′,4′,5,6,7,8-Hexamethoxyflavone (HM) and 5,6,7,8,4′-pentamethoxyflavone (PM) are main bioactive compounds in Chachiensis, which have been reported to possess various biological properties. In this study, supercritical CO2 extraction (SCE) and high-speed countercurrent chromatography (HSCCC) were utilized to prepare HM and PM from Chachiensis. The contents of target compounds were determined by a high-performance liquid chromatography method with diode-array detection (HPLC-DAD), which was validated using the following parameters: linearity, sensitivity, repeatability, stability, precision and accuracy. The SCE conditions were optimized using response surface methodology with central composite design. Obtained optimum conditions were temperature of 37.9 °C, pressure of 26.3 MPa, and modifier volume of 81.0 mL. Under above conditions, the recoveries of target compounds were 92.52 ± 0.83 and 96.36 ± 0.43%, respectively. The most appropriate solvent system for HSCCC was selected as n-hexane/ethyl acetate/methanol/water (1:0.8:1:1.2, v/v). The HSCCC fractions were detected by HPLC-DAD, liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR). The results indicated that this method was successfully applied to obtain HM and PM with high purities and high recoveries from Chachiensis.

7

On the influence of subordinators on extractions from complement clauses

100%

Müller S.

Poznań Studies in Contemporary Linguistics

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2011

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tom 47

538

EN

This paper argues for a semantic account of ungrammatical extractions from ob(‘whether’)-complement clauses in German. Relying on Partition Semantics for a se-mantic characterisation of wh-questions (cf. e.g. Groenendijk and Stokhof 1984) and the concept of index dependency of propositions denoted by [+wh]-complement clauses (cf. Groenendijk and Stokhof 1982), it is argued that the ungrammatical extraction constructions are “defective” on logico-semantic grounds as they can get an interpretation under which no alternative answer opened up by the question can be excluded. By relying on e.g. Fox and Hackl’s (2006) assumptions on contextual blindness (the term being used by Magri 2009), the semantic violation is treated as a constraint that can only be circumvented by evoking contextually invariable means. It is argued that the latter aspect can manifest itself in the occurrence of resumptive pronouns in the extraction domain.

8

A comparative study on the method of extracting edge and contour information of multifunctional digital ship image

100%

Yin F.

Polish Maritime Research

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2017

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tom S 3

235--242

EN

The result of the extraction of the edge and contour information of the multifunctional digital ship image directly affects the evaluation and recognition of the subsequent image quality. At present, the common method used to extract the edge contour information is based on the Canny operator, and there is a problem that the edge is not clear.In order to obtain more accurate edge information, a method of extracting edge and contour information of multimedia digital image based on multi-scale morphology is proposed. Firstly, the digital ship image is made double filter and the fuzzy threshold segmentation, and then the edge and contour information is extracted by multi-scale morphology. Experiments show that the proposed method can obtain more accurate edge information compared with the other methods.

9

Quick and simple speciation analysis of chromium in cements

100%

Grabarczyk M. , Wardak C.

Physicochemical Problems of Mineral Processing

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2022

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tom Vol. 58, iss. 2

art. no. 144445

EN

The extraction of total Cr(VI) from commercially available cements, based on DTPA + 0.2 mol dm-3 (NH4)2SO4/NH4OH mixture solution and subsequent selective determination of Cr(VI) has been proposed. The determination was carried out using the adsorptive voltammetric stripping method. The study was conducted using three different commercially available cement samples. It has been checked that the proposed extraction procedure guaranteed no changes of chromium speciation during cement analysis. For comparison extraction was also carried out with the use of recommended by United States Environmental Protection Agency (EPA) Method 3060A, based on 0.28 mol dm-3 Na2CO3 + 0.5 mol dm-3 NaOH). Additionally, the extraction process was carried out using only distilled water as an extraction mixture which allows to evaluate concentration of only soluble Cr(VI) forms contained in cement. In all three cements, the content of soluble Cr(VI) was below 2 ppm, i.e. the limit value by European Union Directive 2003/53/EC.

10

Optimization of extraction techniques and RP-HPLC analysis of anti-parkinson drug levodopa from flowers of Vicia faba L.

100%

Bulduk I.

Acta Chromatographica

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2020

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tom Vol. 32, no. 4

281--288

EN

Vicia faba, also known as “bakla” in Turkey, is a species of Fabaceae family that is widely grown in Africa and Asia. It is rich in levodopa, a medicinal substance used to treat Parkinson's disease. Levodopa produced by chemical synthesis is expensive and causes various side effects. Therefore, it is recommended to use natural levodopa sources to prevent possible side effects. A Central Composite Design technique has been used in this study to optimize levodopa extraction from Vicia faba. First, a single factor analysis examined 3 variables such as extraction temperature, extraction time, and concentration of acetic acid. The purpose of this study was to assess the effects of variables chosen on levodopa's extraction performance. By using variance and regression analyses, a second-order regression equation was determined as a predicted model. The value of R2 is 0.9882, which shows that the equation fits well. The best conditions are as follows: a temperature of 59.85 °C, an extraction time of 18.74 min, and an acetic acid content of 0.28%. Under optimum conditions, the maximum levodopa yield calculated from the predicted module was 4.53%. Extraction efficiency was determined as 4.54% experimentally under optimum conditions. A good relationship has been found between the experimental result and the predicted value.

11

Extraction of characteristic points from radar image

100%

Praczyk T.

Zeszyty Naukowe / Akademia Morska w Szczecinie

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2008

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tom nr 13 (85)

74-78

EN

The problem of continuous position availability is one of the most important issues connected with human activity at sea. Because the availability of the electronic navigational systems can be limited in some cases (for example during military operations) we should consider additional methods of gathering information about ship's position. In this paper, one of these methods is presented, which is based on extraction of specific features from radar images - characteristic points of the coastline.

PL

Ciągła dostępność pozycji jest jednym z najważniejszych problemów związanych z ludzką działalnością na morzu. Ponieważ dostępność elektronicznych systemów nawigacyjnych może być ograniczona w niektórych przypadkach (np. podczas operacji wojskowych), powinno się rozważyć dodatkowe metody gromadzenia informacji o pozycji statku. Jedna z tych metod, oparta na wybieraniu konkretnych elementów z obrazów radarowych - punkty charakterystyczne lini brzegowej, została zaprezentowana w niniejszym artykule.

12

Supported liquid membrane extraction of peptides.

100%

Drapała A. , Dżygiel P. , Jönsson J. Å. , Wieczorek P.

Acta Biochimica Polonica

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2001

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tom 48

|

nr 4

1113-1116

EN

The application of supported liquid membrane (SLM) extraction for the enrichment of short peptides is presented. The extraction efficiency is dependent on the pH of donor phase and salt concentration in acceptor phase. Moreover, the extraction efficiency is also influenced by the peptide amino-acid sequence and hydrophobicity.

13

Kinetic modeling of chromium(III) extraction with aliquat 336 from alkaline aqueous solutions containing chlorides

100%

Wionczyk B.

Physicochemical Problems of Mineral Processing

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2013

|

tom Vol. 49, iss. 2

587--605

EN

The effects of time, composition and history of preparation of the aqueous phase on the liquidliquid extraction of chromium(III) with Aliquat 336 from the aqueous alkaline solutions containing chlorides were studied. At time far from the equilibrium the yield and initial rate of the chromium(III) extraction depend on NaOH concentration, ionic strength of the aqueous phase and the way of its preparation. At the constant composition of the feed solution, rate of the Cr(III) extraction in approach to the equilibrium is higher when chromium(III) is extracted from the alkaline aqueous phase freshly prepared by direct dissolution of a weighted sample of CrCl3 than from that obtained by dilution of aged stock solution of CrCl3. Kinetic analysis by the mathematical models showed that within the whole period of time needed to reach the equilibrium, the rate of the Cr(III) extraction is limited by the second-, and third-order chemical reaction towards Cr(III), irrespective of composition and preparation history of the aqueous phase. The three-dimensional diffusion and chemical reaction at phase boundary substrateproduct (the contracting volume) models have a significant effect on the chromium(III) extraction within the initial extent of the process.

14

Removal of lindane from wastewater using liquid-liquid extraction process

100%

Patil I. D. , Patil Y. S. , Pangarkar B. L.

Polish Journal of Chemical Technology

|

2013

|

tom Vol. 15, nr 3

81-84

EN

Pesticide pollution is a serious problem being faced. Harmful levels of pesticides are found in the water which is used for daily purposes. In the event of such a scenario, this paper presents a working solution for bringing down the Pesticide levels in the water to safe levels by using the method of liquid-liquid extraction. The experimental liquid-liquid equilibrium data on pesticide-water-solvent ternary mixtures at a temperature of 288.15 K are presented here. The pesticide used here is a chlorinated hydrocarbon called lindane found in the water (underground, land), beverages and foods. The solvents used are Petro-ether-Chloroform (1:1), Ethylene di chloride and n-hexane. The equilibrium generation diagram, triangular diagram, tie lines and bimodal curves as well as the distribution coefficient have been determined and reported. The petro-ether-chloroform was found to be the right solvent for the separation of lindane from wastewater because of high selectivity (25.36) and distribution coefficient (4). The extraction process is simulated into ‘C’ language.

15

Enhancement of Supercritical Fluid Extraction in Membrane Cleaning Process by Addition of Organic Solvents

100%

Krzysztoforski J. , Krasiński A. , Henczka M. , Piątkiewicz W.

Chemical and Process Engineering

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2013

|

tom 34

|

nr 3

403-414

EN

In this study, the process of membrane cleaning by supercritical fluid extraction was investigated. Polypropylene microfiltration membranes, contaminated with oils, were treated in a batch process with a supercritical fluid (SCF). As extractant, pure supercritical carbon dioxide or supercritical carbon dioxide with admixtures of methanol, ethanol and isopropanol were used. Single-stage and multi-stage extraction was carried out and process efficiency was determined. The obtained results showed that addition of organic solvents significantly enhances the cleaning performance, which increases with increase of organic solvent concentration and decreases with increasing temperature. All three solvents showed a comparable effect of efficiency enhancement. The results confirmed that supercritical fluid extraction can be applied for polypropylene membrane cleaning.

16

Solvent extraction of Pr(III), Nd(III), Sm(III) and Eu(III) with 5,7-dichloro-8-hydroxyquinoline from water and water-methanol phases

100%

Czakis-Sulikowska D. , Kuźnik B. , Malinowska A.

Chemia Analityczna

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2001

|

tom Vol. 46, No. 1

93-99

EN

The extraction of Ln(III) (Pr, Nd, Sm, EU) with 5,7-dichloro-8-hydroxyquinoline in chloroform from water and water-methanol phase was studied. The parameters of the extraction process were determined and the separation factors of investigated pairs of lan-thanides were calculated. In the presence of methanol in the water phase the synergistic effect was observed.

PL

Zbadano ekstrakcję Ln(III) (Pr, Nd, Sm, Eu) roztworami 5,7-dichloro-8-hydroksy-chinoliny w chloroformie z fazy wodnej i wodno-metanolowej. Wyznaczono parametry ekstrakcji i obliczono współczynniki separacji poszczególnych par badanych lanta-nowców. W obecności metanolu w fazie wodnej zaobserwowano efekt synergetyczny.

17

The utilization possibility of waste lignite as a raw material in the process of obtaining humic acids preparations

100%

Hoffmann K. , Huculak-Mączka M.

Polish Journal of Chemical Technology

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2012

|

tom Vol. 14, nr 4

1-6

EN

In the light of environmental law utilization lignite waste in non-energy sectors of the economy is a national way to manage them. Lignite due to the lower degree of coalifi cation and calorifi c value as well as a high content of humic substances becomes a valuable component of fertilizer. The paper presents the possibility of using lignite waste as a raw material in the process of obtaining humic acids with 0.1 M NaOH. The idea of the process combines production, environmental and economic purposes. After the extraction process of humic acids and considering the possibility of using waste formed during the process, were carried out a number of studies to assist in choosing the best solution to its management.

18

Nowe tendencje w procesach ekstrakcyjnych

100%

Szymanowski J.

Przemysł Chemiczny

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2003

|

tom T. 82, nr 8-9

792-793

19

Availability of heavy metals in soil of Dąbrowa Górnicza to plants

100%

Wyżgolik B. , Karweta S. , Surowiec E.

Archiwum Ochrony Środowiska

|

2002

|

tom Vol. 28, no. 4

41-50

EN

Elevated content of heavy metals in soils is characteristic of the Dąbrowa Górnicza region. The highest concentrations of lead, cadmium and zinc exceed here 650, 15, and 1000 mg/kg of soil, respectively. Samples of soil from selected sites underwent the speciation analysis with the use of the Tessier method, modified according to Kersten and Forstner. Results of the investigations proved the highest concentrations of these metals in the area of Trzebiesławice. They occur here in the strongly bound forms and, mainly, their occurrence is related to presence of limestone rocks. The greatest amounts of these metals in easily assimilable to plant forms occur within the area of the town of Dąbrowa Górnicza. The most probable source of most of these heavy metals in soils are here contaminants emitted by the industry, mainly by the metallurgy. In the vicinity of the town of Błędów, mainly sandy soils occur, characteristic of which is low content of considered metals. Weak sorption capacities of these soils account for relatively good extractability of the three metals. In soils from the Łęka area, strong binding of these metals was confirmed. Occurrence of cadmium should be of special attention because this metal occurs as built in the crystal lattice of minerals

PL

Gleby na terenie gminy Dąbrowa Górnicza charakteryzują się podwyższoną zawartością metali ciężkich. Najwyższe zawartości ołowiu przekraczają 650 mg/kg, kadmu 15 mg/kg i cynku 1000 mg/kg gleby. Próbki gleby z wybranych punktów podano analizie specjacyjnej według Tessiera w modyfikacji Kerstena i Forstnera. Z przeprowadzonych badań wynika, że na terenie Trzebiesławic stwierdzono najwyższe zawartości tych metali. Występują tutaj w formie silnie związanej i w znacznej części są związane ze skałami wapiennymi. Najwięcej form łatwo przyswajalnych występuje na terenie miasta Dąbrowa Górnicza. najprawdopodobniej większość metali ciężkich w glebie pochodzi z zanieczyszczeń, które były emitowane przez przemysł głównie hutniczy. W rejonie Błędowa występują głównie gleby piaszczyste, które charakteryzują się niską zawartością omawianych metali. Słabe własności sorpcyjne tych gleb sprawiają, że stosunkowo łatwo są ekstrahowane. Spośród badanych gleb na terenie Łęki stwierdzono silne związanie tych metali. Na szczególną uwagę zasługuje występowanie kadmu, który wbudowany jest w sieć krystaliczną minerałów.

20

Optimization of plutonium extraction with methyltrioctylammonium chloride preceding its determination by liquid scintillation spectrometry

100%

Komosa A. , Piekarz M.

Nukleonika

|

2010

|

tom Vol. 55, No. 2

137-141

EN

Optimization of selective extraction conditions for separating plutonium from uranium and thorium standard solutions using methytrioctylammonium chloride (Aliquat 336) as extracting agent is presented. Influence of such parameters as concentration of extracting agent and nitric acid, and kind of reducing agent on the efficiency of extraction were studied. The method was developed for standard solutions of Pu, Th and U. A Quantulus liquid scintillation spectrometer was used for determination of alpha activity of these isotopes. It was found that using HDEHP in the first stage of the elaborated procedure and Aliquat 336 in the next, it is possible to separate Pu from the mixture of U and Th. Optimal values of measuring parameters such as a PSA value and a scintillation cocktail volume were established as well.