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Badanie przepływu kompozytów polimerowo-drzewnych w procesie wytłaczania jednoślimakowego

Wilczyński K., Buziak K., Bartnik M.

Polimery

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2016

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T. 61, nr 3

195--201

PL

Zbadano doświadczalnie przepływ kompozytu polimerowo-drzewnego o zawartości 70 % mas. mączki drzewnej w procesie wytłaczania jednoślimakowego, w różnych warunkach technologicznych przetwórstwa. Przebieg uplastyczniania i przepływu tworzywa oceniono na podstawie tzw. zimnego eksperymentu wytłaczania, z zastosowaniem techniki wyciągania ślimaka. Na podstawie wyników badań zaproponowano mechanizm uplastyczniania jednokierunkowego. Stwierdzono, że modelowanie procesu wytłaczania kompozytów polimerowo-drzewnych wymaga odmiennego podejścia niż modelowanie wytłaczania tworzyw termoplastycznych.

EN

Experimental studies have been done on the flow of wood-polypropylene composite with 70 wt % wood flour loading under various processing conditions of single-screw extrusion. The plasticization and flow of the polymer were evaluated on the basis of so-called cold extrusion experiment using „Screw Pulling-out Technique”. It was stated that the flow of wood-plastic composites is essentially different from the flow of thermoplastics. The flow is accompanied by slipping at the barrel walls, screw and die surfaces, also it shows ayield stress. Melting of the composite with high wood-flour content does not proceed according to the well known Tadmor model. Based on the results of the investigations, one-dimensional model of melting has been proposed. It was stated that the modeling of wood-plastic composite extrusion process requires a different approach then that used to model the extrusion of thermoplastic polymers.

2

Furanocoumarins from Peucedanum tauricum Bieb. and their variability in the aerial parts of the plant during development

Bartnik M., Głowniak K.

Acta Chromatographica

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2007

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No. 18

5-14

EN

A rapid and sensitive reversed-phase high-performance liquid chromatographic (RP-HPLC) method has been used for determination of furanocoumarins in methanolic extracts of Peucedanum tauricum Bieb. HPLC separation was performed on a C18 analytical column (250 mm × 4 mm i.d., 5-μm particles) with a methanol–water gradient as mobile phase. A second chromatographic system with an acetonitrile–water gradient was also developed independently. Diode-array detection was performed between 220 and 400 nm and in quantitative analysis compounds were detected at 320 nm. Calibration plots were linear for 0.01–0.2 mg mL-1 bergapten and peucedanin in methanol (injection volume 10 μL). Before HPLC, samples were purified by solid-phase extraction (SPE). Oxypeucedanin hydrate (oPh), bergapten (5-MOP), oxypeucedanin (oP), peucedanin (P), 8-methoxypeucedanin (mP), and isoimperatorin (isoIMP) were detected and identified in extracts of P. tauricum. Total amounts of furanocoumarins determined by SPE–HPLC were 8.31 mg g-1 dry wt (0.83%) in flowers, 20.49 mg g-1 dry wt (2.05%) in immature fruits, and 21.30 mg g-1 dry wt (2.13%) in mature fruits. The predominant coumarin compound in the reproductive organs was peucedanin – 5.04 mg g-1 dry wt (0.50%) in flowers, 13.58 mg g-1 dry wt (1.36%) in immature fruits, and 13.51 mg g-1 dry wt (1.35%) in completely mature fruits. The predominant furanocoumarin in the leaves, however, was 8-methoxypeucedanin – from 0.55 mg g-1 to 1.02 mg g-1 dry wt (0.06–0.10%). The furanocoumarin content of the plant extracts correlated with period of development and the part of the plant (generative or vegetative). Some of the detected compounds (e.g. peucedanin and 8- methoxypeucedanin, which are both linear furanocoumarins of a rare structural type with restricted occurrence in P. officinale and the closely related species P. coriaceum and P. longifolium) could be a chemotaxonomically characteristic of the species investigated. As we have reported elsewhere, peucedanin is effective at induction of apoptosis and inhibition of heatshock protein expression in HeLa cells. The fruits of P. tauricum are a good source of peucedanin for further biological and pharmacological tests.

3

Nietolerancja glutenu

Bartnik M.

Przemysł Spożywczy

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1999

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T. 53, nr 7

33-34

PL

W artykule przedstawiono niektóre ważniejsze problemy dotyczące celiakii (m.in. toksyczność białek prolaminowych, produkty bezglutenowe i problemy legislacyjne, wykorzystanie owsa, gryki i amarantusa w diecie bezglutenowej).

EN

Aspects of coeliac disease are discussed from the viewpoint of different problems connected with the dietetic therapy (e.g. toxicity of prolamins, gluten-free products and legal problems, oats, buckwheat and amaranthus in gluten-free diets).

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Żywność ekologiczna w opinii konsumentów

Bartnik M., Moroz A.

Przemysł Spożywczy

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1998

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T. 52, nr 10

18-21

PL

W artykule scharakteryzowano stosunek do żywności ekologicznej konsumentów różnych krajów: USA, krajów Europy Zachodniej i Polski. Żywność ta - produkowana bez stosowania w rolnictwie środków chemicznych - jest trudna do odróżnienia od żywności produkowanej w sposób konwencjonalny, a ceny jej są z reguły wyższe. Konsumentów interesuje problem jakości żywności ekologicznej, a zwłaszcza odpowiedź na pytanie, czy jest ona faktycznie" zdrowsza" od żywności konwencjonalnej?

EN

"Organic foods" are commonly represented as food grown without pesticides, artificial fertilizers, which has not been treated with preservatives, hormones, antibiotics etc. There is no method for distinguishing between "organic" and "conventional" foods. Prices of "organic" foods tend to be higher than those of their "conventional" foods. This article discusses several problems of the quality of organic foods vs. conventional foods (is organic food healthier than conventional food) and consumer attitudes and expectations to organic foods in different countries: USA, Europe and Poland.