Analysis of protein-based media commonly found in paintings using synchronous fluorescence spectroscopy combined with multivariate statistical analysis

The spectrofluorimetric analysis of protein-based binding media, which are commonly found as painting materials, is based on the detection of emissions from amino acids, as well as fluorescent degradation products that develop with aging. Laser-induced fluorescence spectroscopy, fluorescence excitation emission spectroscopy, and time-resolved fluorescence spectroscopy have all been employed in efforts to discriminate between commonly found proteinaceous binding media, including egg white, egg yolk, milk, and casein, as well as collagen-based glues from rabbit skin, ox bone, parchment, and fish. However, synchronous fluorescence spectroscopy (SFS), a rapid means of recording fluorescence properties of samples, has not been reported for the differentiation between binding media. This work focuses on the analysis of a large set of naturally aged films of different protein-based binding media using SFS with a range of different offsets between excitation and emission monochromators between 30-60 nm. An interpretation of synchronous fluorescence spectra of binding media is presented and is followed by an assessment and classification of a database of recorded spectra using multivariate analysis. Importantly, following SFS analysis of films of binding media, principal component analysis is used to differentiate among all the proteinaceous media considered on the basis of clustering of data. This application is thus a novel and nondestructive means for differentiation between protein-based binding media.     

Inorganic–organic hybrid materials based on functionalized silica and carbon: A comprehensive understanding toward the structural property and catalytic activity difference over mesoporous silica and carbon supports

Inorganic–organic hybrid materials based on functionalized silica and carbon were synthesized by anchoring molybdovanadophosphoric acid (H₅[PMo₁₀V₂O₄₀] · 32.5H₂O) onto amine-functionalized SBA-15, ethane-bridged SBA-15 and mesoporous carbon, respectively. Small angle X-ray diffraction, N₂ sorption analysis, HRTEM, SEM, FT-IR, CP-MAS NMR were used to diagnose the mesoporous structure of inorganic–organic hybrid materials. The structural integrity of molybdovanadophosphoric acid has been found to be retained after immobilization over mesoporous materials. These inorganic–organic hybrid materials were tested in the environmentally friendly oxidation of 2-methylnaphthalene (2MN) with 30% aqueous hydrogen peroxide. Molybdovanadophosphoric acid containing mesoporous organosilica hybrid material (ethane-bridged SBA-15) exhibited higher catalytic activities in the oxidation of 2MN to give a clean product 2-methy-1,4-naphthoquinone (menadione vitamin K3 precursor), because of the improved hydrophobicity of the material. The correlation between structural properties and catalytic activities of these hybrid materials has been well addressed in our present studies.     

Differential outcomes enhance accuracy of delayed matching to sample but not resistance to change.

Three experiments assessed the relation between the differential outcomes effect and resistance to change of delayed matching-to-sample performance. Pigeons produced delayed matching-to-sample trials by responding on variable interval schedules in two components of a multiple schedule. In the same-outcome component, the probability of reinforcement was the same for both samples (.9 in Experiments 1 and 2, .5 in Experiment 3); in the different-outcomes component, the probability of reinforcement was .9 for one sample and .1 for the other. In all three experiments, the forgetting functions in the different-outcomes component were higher and shallower than in the same-outcomes component. When total reinforcement was greater in the same-outcomes component (Experiments 1 and 2), resistance to disruption by prefeeding, intercomponent food, extinction, or flashing lights typically was greater in that component. In Experiment 3, when total reinforcement was equated, resistance to disruption was similar across components. Thus, the level and slope of forgetting functions depended on differential reinforcement correlated with the samples, but the resistance to change of forgetting functions depended on total reinforcement in a component. Both aspects of the results can be explained by a model of delayed matching to sample performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Polyimides from a Novel Monomer 3,6-Bis(dimethylamino)acridine(p-cymene)dichlororuthenium(II) for a Catalytic Application

Tricyclic heteroaraomatic dye-based monomer containing NMe₂ units, 6-bis(dimethylamino)acridine(p-cymene)dichlororuthenium (II), was used to prepare novel polyimides via a one-stage solution polycondensation due to their stability under a variety of oxidative and reductive conditions. The Ru(II) complex monomer was synthesized starting from [RuCl₂(p-cymene)]₂ and 3,6-bis(dimethylamino)acridine. A series of stable polyimides was synthesized from the Ru(II) complex of 3,6-bis(dimethylamino)acridine and various aromatic dianhyrides. The polymers had inherent viscosities ranging from 1.72 to 2.11 dL/g and were soluble in polar solvents. The glass transition temperatures were 192–278 °C, and the 10% weight loss temperatures were above 503–635 °C. Ruthenium-substituted polyimides were tested for catalytic activity in the furan formation reaction of (Z)-3-methylpent-2-en-4-yn-1-ol. The polymeric catalyst was added to (Z)-3-methylpent-2-en-4-yn-l-ol without a solvent and the pure furan was isolated by distillation under reduced pressure. The conversion of the starting, enynol, was determined by gas chromatography (GC).     

Acrylate monomers from olefins via tertiary butyl hypochlorite

A variety of olefins were readily converted to acrylate monomers by combining them with t-butyl hypochlorite and acrylic or methacrylic acid at 25–65°C. The predominate product was the vicinal acyloxychloro derivative formed by addition at the olefinic double bond. By-products were the vicinal butoxychloro derivative and the still unsaturated chlorinated olefin. The main reaction was shown to occur by an ionic mechanism. 2-Chloro-1-methyl propyl methacrylate was isolated and identified as the main product of the reaction of 2-butene, methacrylic acid, and t-butyl hypochlorite. The crude olefin products readily homopolymerized and copolymerized with other vinyl monomers by incorporating free-radical initiators.     

Essential oils of Turkish anise seeds and their use in the aromatization of raki

The objectives of this study were the characterization of Turkish anise seeds, their essential oils, and investigations into the suitability of the direct use of these oils in the production of raki, a traditional Turkish distilled liqueur. The moisture, protein, ash, acid-insoluble ash, nonvolatile ethyl ether and ethanol extracts, and essential oil contents of anise seeds were determined, as were the specific gravity, refractive index, solidification point and chemical composition of anise essential oil. Finally a series of raki samples were produced, on a laboratory scale, using rectified anise essential oils obtained in this study as well as those imported and these were compared with traditionally produced rakis by a specially trained panel. The results of sensory analyses were quite promising for the use of anise essential oil as a direct flavouring additive to Turkish raki.

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Ätherische Öle türkischer Anissamen und deren Eignung für die Herstellung von Raki

Zusammenfassung Arbeitsziele waren die Charakterisierung türkischer Anissamen, ihrer ätherischen Öle und Untersuchungen zu deren Anwendbarkeit bei Herstellung von Raki, einem traditionellen türkischen alkoholischen Getränk. Zu diesem Zweck wurden der Feuchtigkeitsund Proteingehalt, der Anteil an Asche, deren säuereunlöslicher Anteil, die Äthyläther- und Äthanolextrakte und der Gehalt an ätherischen Ölen lokal vorkommender Anissamen, ferner die spezifische Dichte, der Brechungsindex und die chemische Zusammensetzung bestimmt. Die rektifizierten Öle wurden dann im Labormaßstab zur Raki-Herstellung genutzt. Die Produkte wurden auf ihre sensorischen Qualitäten hin untersucht sowie mit traditionell hergestelltem Raki verglichen. Die Ergebnisse sind vielversprechend im Hinblick auf eine kommerzielle Nutzung.

     

Model-based multidimensional clustering of categorical data

Existing models for cluster analysis typically consist of a number of attributes that describe the objects to be partitioned and one single latent variable that represents the clusters to be identified. When one analyzes data using such a model, one is looking for one way to cluster data that is jointly defined by all the attributes. In other words, one performs unidimensional clustering. This is not always appropriate. For complex data with many attributes, it is more reasonable to consider multidimensional clustering, i.e., to partition data along multiple dimensions. In this paper, we present a method for performing multidimensional clustering on categorical data and show its superiority over unidimensional clustering.     

Surface-tension determinations with a precision micro capillary rise apparatus

Summary Details of apparatus construction and refinements are presented for a micro capillary rise method of determining absolute values of surface tension. Experimental values of surface tension for benzene, n-pentadecane, and methyl laurate are recorded and compared with previous literature values. Parachors are determined. The method requires a minute amount of sample and is simple, quick, precise, and accurate. Published with the approval of the Director of Research, North Carolina Agricultural Experiment Station, as Paper No. 576 of the Journal Series.     

Polyimides from a Novel Monomer 3,6-Bis(dimethylamino)acridine(p-cymene)dichlororuthenium(II) for a Catalytic Application

Tricyclic heteroaraomatic dye-based monomer containing NMe₂ units, 6-bis(dimethylamino)acridine(p-cymene)dichlororuthenium (II), was used to prepare novel polyimides via a one-stage solution polycondensation due to their stability under a variety of oxidative and reductive conditions. The Ru(II) complex monomer was synthesized starting from [RuCl₂(p-cymene)]₂ and 3,6-bis(dimethylamino)acridine. A series of stable polyimides was synthesized from the Ru(II) complex of 3,6-bis(dimethylamino)acridine and various aromatic dianhyrides. The polymers had inherent viscosities ranging from 1.72 to 2.11 dL/g and were soluble in polar solvents. The glass transition temperatures were 192–278 °C, and the 10% weight loss temperatures were above 503–635 °C. Ruthenium-substituted polyimides were tested for catalytic activity in the furan formation reaction of (Z)-3-methylpent-2-en-4-yn-1-ol. The polymeric catalyst was added to (Z)-3-methylpent-2-en-4-yn-l-ol without a solvent and the pure furan was isolated by distillation under reduced pressure. The conversion of the starting, enynol, was determined by gas chromatography (GC).