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51.
Magdalena Wirkowska Ewa Ostrowska-Lig?za Agata Górska Piotr Koczoń 《Journal of Thermal Analysis and Calorimetry》2012,110(1):137-143
The aim of this research was to analyse composition, fatty acids distribution and oxidative stability of fats extracted from four samples of baby formulas. The fats were oxidized in a differential scanning calorimeter (DSC) under polythermal (dynamic) conditions and at normal pressure. The DSC experiments were carried out in an oxygen flow atmosphere using different, linearly programmed, heating rates in the range of 4?C12.5?°C/min. The extrapolated onset temperatures were determined using DSC exotherms and used for the assessment of the thermal oxidative stabilities of the samples. Activation energies (E a), pre-exponential factors (Z) and reaction rate constants (k) for oil oxidation under DSC conditions were calculated using the Ozawa?CFlynn?CWall method and the Arrhenius equation. The melting characteristics of the studied fats were obtained. The fats extracted from the agglomerated samples with higher onset temperatures were more stable than the fats extracted from the initial samples of baby formulas. 相似文献
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Migas Piotr Heyka Magdalena Pobłocka-Olech Loretta Krauze-Baranowska Mirosława 《平面色谱法杂志一现代薄层色谱法》2012,25(5):439-444
JPC – Journal of Planar Chromatography – Modern TLC - Three step bivariant multiple development thin-layer chromatography (BMD-TLC) technique was used in the quantitative analysis of... 相似文献
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Thomas Ihn Susanne Dröscher Stephan Schnez Helena Knowles Johannes Güttinger Magdalena Huefner Christoph Stampfer Yigal Meir Klaus Ensslin 《Solid State Communications》2012,152(15):1306-1310
We report two experiments on graphene nanostructures. The first was performed on a graphene nanoribbon, where the nature of electronic transport was investigated in detail. Electrons or holes are found to localize in pockets of the potential along the ribbon. Transport is governed by the joint action of localization and Coulomb interaction. The temperature-dependence of the conductance shows activated behavior at temperatures above a few Kelvin. The activation energy retraces the edges of Coulomb blockade diamonds found in nonlinear transport. In the second experiment the metallic tip of a low-temperature scanning force microscope was scanned above a graphene quantum dot. In addition to the familiar Coulomb blockade fringes, localized states are detected forming in the constrictions connecting the dot to source and drain. 相似文献
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Green synthesis and antibacterial effects of aqueous colloidal solutions of silver nanoparticles using clove eugenol 下载免费PDF全文
Magdalena Parlinska‐Wojtan Joanna Depciuch Bartosz Fryc Małgorzata Kus‐Liskiewicz 《应用有机金属化学》2018,32(4)
Silver nanoparticles were synthesized using clove extract (CE). Scanning transmission electron microscopy (STEM) revealed the morphology of the metallic Ag nanoparticles obtained via the clove extract synthesis (Ag NPs‐CE), which had a uniform distribution and average sizes varying from 10 nm to 100 nm. Fourier transform infra‐red (FTIR) spectroscopy showed that clove eugenol acts as a capping and reducing agent being adsorbed on the surface of Ag NPs‐CE, enabling their reduction from Ag+ and preventing their agglomeration. Formation of the Ag0 structure is also confirmed in the FTIR spectrum by the presence in the Ag NPs‐CE sample of the –C=O and –C=C vibrations at wavenumbers 1600 and 2915 cm‐1, respectively. Antibacterial and antifungal tests using three strains of bacteria and one fungi strain showed that the Ag NPs‐CE performed better compared to pure clove extract (CE) sample. 相似文献
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Filip Ciesielczyk Przemysław Bartczak Karolina Wieszczycka Katarzyna Siwińska-Stefańska Magdalena Nowacka Teofil Jesionowski 《Adsorption》2013,19(2-4):423-434
The aim of this work was to obtain an inorganic oxide system containing silica and magnesium oxide, and characterized by specific physicochemical properties, in particular well-defined adsorption parameters. The preparation process was carried out according to a co-precipitation method using solutions of sodium silicate and selected inorganic magnesium salt. The oxide system obtained (MgO·SiO2) was used as a support (adsorbent) of nickel(II) ions, whose precursors were model solutions of nitrates. The effectiveness of the adsorption process was evaluated using many different analytical techniques, including atomic absorption spectroscopy, energy dispersive X-ray spectroscopy and equivalent point titration. Moreover the stability of adsorbent/adsorbate bonding was estimated. The oxide systems—adsorbents—used in the process were also analyzed according to their physicochemical properties, especially changes in adsorption parameters. The last part of the study involved evaluation of the kinetics of the adsorption process depending on time and the pH of the reaction system. 相似文献