Nanocasting of Mesoporous In‐TM (TM = Co,Fe, Mn) Oxides: Towards 3D Diluted‐Oxide Magnetic Semiconductor Architectures

Transition metal (Co, Fe, Mn)‐doped In₂O_3?y mesoporous oxides are synthesized by nanocasting using mesoporous silica as hard templates. 3D ordered mesoporous replicas are obtained after silica removal in the case of the In‐Co and In‐Fe oxide powders. During the conversion of metal nitrates into the target mixed oxides, Co, Fe, and Mn ions enter the lattice of the In₂O₃ bixbyite phase via isovalent or heterovalent cation substitution, leading to a reduction in the cell parameter. In turn, non‐negligible amounts of oxygen vacancies are also present, as evidenced from Rietveld refinements of the X‐ray diffraction patterns. In addition to (In_1?xTM_x)₂O_3?y, minor amounts of Co₃O₄, α‐Fe₂O₃, and Mn_xO_y phases are also detected, which originate from the remaining TM cations not forming part of the bixbyite lattice. The resulting TM‐doped In₂O_3?y mesoporous materials show a ferromagnetic response at room temperature, superimposed on a paramagnetic background. Conversely, undoped In₂O_3?y exhibits a mixed diamagnetic‐ferromagnetic behavior with much smaller magnetization. The influence of the oxygen vacancies and the doping elements on the magnetic properties of these materials is discussed. Due to their 3D mesostructural geometrical arrangement and their room‐temperature ferromagnetic behavior, mesoporous oxide‐diluted magnetic semiconductors may become smart materials for the implementation of advanced components in spintronic nanodevices.     

Reversible Amorphous‐to‐Amorphous Transitions in Chalcogenide Films: Correlating Changes in Structure and Optical Properties

Structural transitions in materials are accompanied by appreciable and exploitable changes in physical‐chemical properties. Whereas reversible optically‐driven atomistic changes in crystal‐to‐amorphous transitions are generally known and exploited in applications, the nature of the corresponding polyamorphic transitions between two structurally distinct meta‐stable amorphous phases is an unexplored theme. Direct experimental evidence is reported for the nature of the atomistic changes during fully reversible amorphous‐to‐amorphous switching between two individual states in the non‐crystalline As₅₀Se₅₀ films prepared by pulsed‐laser deposition and consequent changes in optical properties. Combination of surface sensitive X‐ray photoelectron spectroscopy and spectroscopic ellipsometry show that the near‐bandgap energy illumination and annealing induce reversible switching in the material's structure by local bonding rearrangements. This is accompanied by switching in refractive index between two well‐defined states. Exploiting the pluralism of distinct structural states in a disordered solid can provide new insights into the data storage in emerging optical memory and photonic applications.     

Wild melon: a novel non-edible feedstock for bioenergy

In the present research work, a non-edible oil source Cucumis melo var. agrestis(wild melon) was systematically identified and studied for biodiesel production and its characterization. The extracted oil was 29.1% of total dry seed weight. The free fatty acid value of the oil was found to be 0.64%, and the single-step alkaline transesterification method was used for conversion of fatty acids into their respective methyl esters. The maximum conversion efficiency of fatty acids was obtained at 0.4 wt% Na OH(used as catalyst), 30%(methanol to oil, v/v) methanol amount, 60 ℃ reaction temperature,600-rpm agitation rate and 60-min reaction time. Under these optimal conditions, the conversion efficiency of fatty acid was 92%. However, in the case of KOH as catalyst, the highest conversion(85%) of fatty acids was obtained at 40%methanol to oil ratio, 1.28 wt% KOH, 60 ℃ reaction temperature, 600-rpm agitation rate and 45 min of reaction time.Qualitatively, biodiesel was characterized through Fourier transform infrared spectroscopy(FTIR) and gas chromatography and mass spectroscopy(GC–MS). FTIR results demonstrated a strong peak at 1742 cm~(-1), showing carbonyl groups(C=O)of methyl esters. However, GC–MS results showed the presence of twelve methyl esters comprised of lauric acid, myristic acid, palmitic acid, non-decanoic acid, hexadecanoic acid, octadecadienoic acid and octadecynoic acid. The fuel properties were found to fall within the range recommended by the international biodiesel standard, i.e., American Society of Testing Materials(ASTM): flash point of 91 ℃, density of 0.873 kg/L, viscosity of 5.35 c St, pour point of-13 ℃, cloud point of-10 ℃, total acid number of 0.242 mg KOH/g and sulfur content of 0.0043 wt%. The present work concluded the potential of wild melon seed oil as excellent non-edible source of bioenergy.     

Maillard reaction during the processing of ‘Doce de leite’

‘Doce de leite’, a dairy product widely consumed in Brazil as a dessert or cake filling, is obtained from the heat treatment of milk and sucrose. On heating, the Maillard reaction occurs with the formation of desirable brown-coloured products with a characteristic and pleasant flavour. However, the reaction can also lead to changes in nutritive value. In order to follow chemically the extension of the Maillard reaction and its effect on the nutritive value of ‘doce de leite’ its commercial processing was followed. Increases in the level of free 5-hydroxymethylfurfural and in absorption at 420 nm by pigments attached to the protein were observed. The amino acid analysis showed a significant decrease in lysine levels (33%) as well as in arginine (11%) and histidine (10%). There was also a reduction in available lysine levels, as measured by the fluorodinitrobenzene (50.6%) and by the 2,4,6-trinitrobenzenesulphonic acid (23.5%) methods. These results suggest a deleterious effect of the processing of ‘doce de leite’ on the nutritive value of the milk.     

The EuQoS system: a solution for QoS routing in heterogeneous networks [Quality of Service based Routing Algorithms for Heterogeneous Networks]

EuQoS is the acronym for "end-to-end quality of service support over heterogeneous networks", which is a European research project aimed at building an entire QoS framework, addressing all the relevant network layers, protocols, and technologies. This framework, which includes the most common access networks (xDSL, UMTS, WiFi, and LAN) is being prototyped and tested in a multidomain scenario throughout Europe, composing what we call the EuQoS system. In this article we present the novel QoS routing mechanisms that are being developed and evaluated in the framework of this project. The preliminary performance results validate the design choices of the EuQoS system, and confirm the potential impact this project is likely to have in the near future     

Defecting From the Gutenberg Legacy: Employing Images to Test Knowledge Gaps

Education‐based knowledge gaps are well‐documented across countries, media platforms, and content. Without exception, knowledge is measured through words not images. Given the centrality of sight in the natural history of Homo sapiens, the extraordinary visual acuity of humans, and the proliferation of screen‐based visual media environments in contemporary life, an experiment was conducted to test the knowledge gap visually. Participants watched 8 audiovisual news stories. Simple recognition of story details and comprehension of that information were tested in verbal and visual modalities. Results offered the first confirmation of the knowledge gap in visual terms. Yet, gaps were significantly smaller employing visual than verbal measures, pointing to the need for continued efforts to develop visual measures for future memory studies.     

Composition and antioxidant activity of essential oils from Oregano plants grown wild in Greece

In this study, four samples of essential oils obtained from plant species with a wide distribution in Greece and economic importance for the world-wide spice market and also carvacrol and thymol were tested for their possible antioxidant activity. The four plant species wereOriganum vulgare subsp.hirtum, O. onites, Coridothymus capitatus andSatureja thymbra. The essential oils were chemically characterised by gas chromatography-ion trap detection. All the essential oils examined and also carvacrol and thymol were found to have antioxidant activity when tested on TLC plates and by measuring peroxide values of lard stored at 35° C. The results indicate that the antioxidant effect may be related to the presence of carvacrol and thymol in essential oils.     

Tocopherol and tocotrienol compositions of raw table olive fruit

The tocopherol (Tp) and tocotrienol (Tt) compositions of raw Greek olive fruit pericarp were determined by high-performance liquid chromatography. The following four types of fruit collected from three main varieties of olive trees were analysed: ‘Conservolea’ (green), ‘Halkidiki’ (green), ‘Conservolea’ (black) and ‘Calamon’ (black). α-Tp was found to be the predominant Tp in all types. The variety and stage of maturity influenced the Tp and Tt composition. β-Tp and α-Tt were found only in trace quantities in green olives. The same was true for α-Tp in all types and γ-Tp in ‘Conservolea’ (green). The calculated α-Tp equivalents (Tp and Tt compositions expressed as α-Tp according to their relative biological activities) were 21·6, 29·7, 36·8 and 39·4 μg g^?1 pericarp or 138, 132, 189 and 196 μg g^?1 lipid for ‘Conservolea’ (green), ‘Halkidiki’ (green), ‘Conservolea’ (black) and ‘Calamon’ (black), respectively.