Wyniki wyszukiwania - BazTech

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Comparative Analysis of Phenolic and Flavonoid content, Antioxidant, Antibacterial Activities, and Functional Groups of Chemicals from Hypericum perforatum L., and Papaver Rhoeas L. Flower Extracts

Afqir Hajar, Belmalha Saadia, Farihi Ayoub, Elbouzidi Amine, Bouhrim Mohamed, Elrherabi Amal, Boutagayout Abdellatif, Oubihi Asmae, Ouhssine Mohammed

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 2

88--101

EN

In this study, the authors aimed to compare the phytochemical compounds (polyphenols and flavonoids), antioxidant activity, functional groups present in the compounds (FTIR), and anti-microbial effects, in the aqueous and methanol extracts obtained from flowers of commercial Hypericum perforatum and native Papaver Rhoeas from Morocco. P. Rhoeas L was collected from El Lhaj Kaddour near Meknes, while H. perforatum L was bought in a dried state from a Moroccan herbalist in the same city. Total polyphenols were evaluated using the Folin-Ciocalteu reagent, respectively. The antioxidant activity was assessed via DPPH and antimicrobial effects were tested against six bacteria (Gram– and Gram+). The aqueous and methanol extracts of P. Rhoeas had the highest TPC value (23.67 ± 0.94 mg GAE/g; 15.86 ± 0.65 mg GAE/g) compared to H. perforatum (15.26 ± 1.30 mg GAE/g; 5.50 ± 1.13 GAE/g). The aqueous extract of Papaver Rhoeas exhibited the highest TFC at 14.36 ± 0.49 mg QE/g, while the methanol extract of Hypericum perforatum had the highest 10.65 ± 0.49 mg QE/g in TFC. In contrast, the methanol and aqueous extracts of H. perforatum showed significant zones of inhibition against Staphylococcus aureus (9.5 ± 0.5 mm and 10.17 ± 0.29 mm) and Staphylococcus epidermidis (8.33 ± 0.58 mm and 9.33 ± 0.58 mm) respectively, with a minimum inhibitory concentration was estimated at 10 μL/ml. The FTIR analysis demonstrated that the extracts of both plants are rich in bioactive molecules with potential biological activities and a pharmaceutical industry perspective. Consequently, these Papaver Rhoeas and Hypericum perforatum extracts exhibit antioxidant and antibacterial activities.

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Zastosowanie metod spektroskopowych do oznaczania zawartości pierwiastków i jonów

Malec Agnieszka, Borowski Gabriel

LAB Laboratoria, Aparatura, Badania

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2019

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R. 24, nr 1

10--14

PL

W artykule przedstawiono najczęściej stosowane metody spektroskopowe służące do oznaczania zawartości pierwiastków i jonów w materiałach stałych i ciekłych. Wyjaśniono sposób prowadzenia oznaczeń w każdej metodzie oraz omówiono jej wady i zalety. Przedstawiono procedurę przygotowania próbek materiałów do analizy. Zaprezentowano również przykładowe wyniki oznaczeń pierwiastków w spektroskopie emisyjnym ICP-OES w porównaniu do wyników referencyjnych. Stwierdzono dużą zgodność zmierzonych zawartości pierwiastków z wartościami referencyjnymi, co potwierdza bardzo dużą dokładność wybranej metody spektroskopowej.

3

Sonochemical-assisted magnesium borate synthesis from different boron sources

Yildirim M., Kipcak A. S., Derun E. M.

Polish Journal of Chemical Technology

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2017

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Vol. 19, nr 1

81--88

EN

In this study, sonochemical-assisted magnesium borate synthesis is studied from different boron sources. Various reaction parameters are successfully applied by a simple and green method. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopies are used to characterize the synthesized magnesium borates on the other hand surface morphologies are investigated by using scanning electron microscope (SEM). The XRD analyses showed that the products were admontite [MgO(B2O3)3 · 7(H2O)] with JCPDS (Joint Committee on Powder Diffraction Standards) no. of 01-076-0540 and mcallisterite [Mg2(B6O7(OH)6)2 · 9(H2O)] with JCPDS no. of 01-070-1902. The results that found in the spectroscopic studies were in a good agreement with characteristic magnesium borate bands in both regions of infra-red and visible. According to SEM results, obtained borates were in micro and sub-micro scales. By the use of ultrasonication, reaction yields were found between 84.2 and 97.9%. As a result, it is concluded that the sonochemical approach is a practicable synthesis method to get high efficiency and high crystallinity in the synthesis magnesium borate compounds.

4

Annealing temperature effect on structural, morphological and optical parameters of mesoporous TiO2 film photoanode for dye-sensitized solar cell application

Hossain M. K., Pervez M. F., Mia M. N. H., Tayyaba S., Uddin M. J., Ahamed R., Khan R. A., Hoq M., Khan M. A., Ahmed F.

Materials Science Poland

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2017

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Vol. 35, No. 4

868--877

EN

Use of Degussa P25 titanium-dioxide nanopowder in dye-sensitized solar cell (DSSC) photoanode improves efficiency of the DSSC cell. Annealing of titanium dioxide is required for fabrication of crystalline mesoporous thin film photoanode on transparent conducting glass using doctor blade method. Different annealing temperatures provide different structural, morphological, and optical properties of the photoanode, which may influence the efficiency of the cell. In this paper, energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and UV-Vis-NIR spectroscopicanalysis have been carried out to investigate annealing temperature effect on various structural parameters, mole-fraction, phase-content, and optical bandgap of the TiO2 film photoanode. It was observed that depending on annealing temperature, theratio of polymorphs of Degussa P25 changed substantially. For the change in annealing temperature from 350 °C to 600 °C, variations occurred in crystallite size from 11.9 nm to 24.9 nm, strain from 0.006 to 0.014, specific surface area from 62.77 m2·g-1 to 125.74 m2·g-1, morphology index from 0.49 to 0.64, dislocation density from 5 × 1013 line/m2 to 8 × 1015 line/m2·, crystallite per unit surface area from 2 × 1013 m-2·to 2.5 × 1014·m-2·, and optical bandgap from 2.4 eV to 3.1 eV.

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Zastosowanie analizy spektroskopowej w podczerwieni w badaniach skał z pogranicza diagenezy i anchimetamorfizmu

Kowalska S., Przelaskowska A., Mroczkowska-Szerszeń M.

Nafta-Gaz

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2012

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R. 68, nr 12

949--958

PL

W artykule przedstawiono przykład zastosowania analizy spektroskopowej w podczerwieni w badaniach skał z pogranicza diagenezy i metamorfizmu niskiego stopnia. Podstawowym założeniem przeprowadzonych badań było odniesienie względem siebie dwóch indeksów mogących służyć jako paleotermometry indeksu Flehmiga oraz indeksu Küblera. Oba indeksy umożliwiają oznaczanie stopnia diagenezy materiału pelitycznego w oparciu o analizę postępu procesu illityzacji smektytu. W rozpatrywanym zakresie temperatur analizowany jest głównie stopień rekrystalizacji materiału illitowego w muskowit.

EN

The article describes the application of spectroscopic infrared analysis for diagenetic and very low grade metamorphic rocks. The aim of the research was to compare two indices that can be used as paleothermometers – the Flehmig index and the Kübler index. Both of them allow to analyze the diagenesis grade of the pelitic rocks based on the smectite illityzation process completion (in the researched temperature range it is mainly recristallization grade of illitic material into muscovite).

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Dust components identification by emission spectroscopy in back discharge

Czech T., Krupa A., Lackowski M., Rajch E.

Environment Protection Engineering

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2006

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Vol. 32, nr 3

55-62

EN

The results of emission spectroscopic analysis of back discharge generated in the point-to-plane electrode covered with fly ash layer of high resistivity in ambient air were presented. The visual forms of the discharge were recorded with digital camera referred to the current-voltage characteristics and optical emission spectra. The interest in these studies was motivated by detrimental effects which this type of discharge causes in the electrostatic precipitators. The studies have shown that the spectral lines omitted the back discharge are unique and dependent on discharge current. The spectral lines could be used for investigation of dust layer composition.

PL

Wyładowanie wsteczne powstaje na elektrodzie biernej w obecności warstwy dielektrycznej o dużej rezystywności. Przedstawiono wyniki badań wyładowania wstecznego dla elektrody uziemionej, pokrytej warstwą pyłu z elektrofiltru. Strimery w wyładowaniu wstecznym rozwijają się pomiędzy elektrodą ulotową a kraterem powstałym w warstwie dielektrycznej. Gdy zwiększa się napięcie, wyładowanie strimerowe może przejść w wyładowanie łukowe. Cechą wyładowania wstecznego do warstwy pyłu w powietrzu jest pojawienie się intensywnego pasma molekularnego azotu (N2). Oprócz głównych pasm azotu zidentyfikowano również pasma NO i NO2 o mniejszej intensywności. Obserwowano również linie atomowe pierwiastków, np. Co, Fe, Mo, Ni, Ti, oraz ich tlenków. W wyniku wyładowania metale z pyłu osadzonego na elektrodzie mogą być wtórnie emitowane do atmosfery.