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Czarnuszka siewna (Nigella sativa L.): Skład chemiczny i aktywność biologiczna

Wajs A., Kalemba D.

Zeszyty Naukowe. Chemia Spożywcza i Biotechnologia / Politechnika Łódzka

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2003

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Z. 67

121-141

PL

W pracy dokonano przeglądu literatury dotyczącej badań nad czarnuszką siewną (Nigella sativa L.). Omówiono skład chemiczny, aktywność biologiczną i zastosowanie nasion rośliny. Szczególny nacisk położono na skład i właściwości olejku eterycznego z nasion N. sativa.

EN

This review includes the relevant literature on Nigella sativa, describes recent advantages regarding to chemical composition, properties and application of black cumin, especially essential oil from the seeds.

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Supercritical carbon dioxide extraction from solid matrix of vegetable origin

Wawrzyniak P., Kalemba D., Wajs A.

Polish Journal of Chemical Technology

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2003

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Vol. 5, nr 4

67-69

EN

The supercritical fluid extraction (SFE) of Nigella sativa L. (black cumin) was studied using Nigella seeds as a row material and CO2 as a solvent. Nigella sativa is widely distributed in Europe and western Asia. The Nigella seeds have been reported to have many medical properties and are used in folk medicine and as a spice in food. The effect of operation conditions was analyzed in a series of experiments at temperatures between 280 and 313 K and pressures between 8 and 10.0 MPa. The experimental data were analyzed in terms of yield, solvent requirement, loading, percent recovery and extraction rate. The results were compared with these obtained by solvent extraction of the material in Soxhlet apparatus by means of hexane. Volatiles were obtained from the extracts by hydrodistillation. The same volatile constituents in similar contents were identified in both SFE and hexane extracts. Chemical characterization of the compounds was carried out by the means of GC and GC-MS analysis. The non-volatile fraction will be subjected to further analysis.

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Dc/Dc Resonant Converter with a One-switch Synchronous Regulator

Wajs A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2001

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vol. 49, nr 1

101-117

EN

The paper presents a resonsnt dc/dc converter with a one-switch synchronous regulator and a Class E amplifier. The circuit diagram, its principle of operation and a theoretical analysis of a one-switch synchronous regulator and experimental results for resonant dc/dc converter are given. The persented one-switch synchronous regulator [1] is a modification of a two-switch synchronous regulator [2], [3]. Due to resonant technique of shaping current and voltage waveforms in semiconductor switches in these power-supply systems switching losses have been reduced. This advantage makes possible to operate the converter at a high and constant frequency with good efficiency, which enables it to achieve a high degree of miniaturisation as well as a low level of emitted electromagnetic interferences. The proposed circuit can find applications in power-supply systems in telecommunications, aircraft and computers.