Structural Characterization of Aniline-Bentonite Composite by FTIR,DTA/TG,and PXRD Analyses and BET Measurement

ABSTRACT

The aniline species incorporated into the acid-activated bentonite matrices leads to the decay of the skeletal stretches centered at 1041 cm^?1 and the rise of new features in the phenyl ring frequency region, 1700–1400 cm^?1, demonstrates clearly the influence of the acid activation on the Lewis sites necessary for coordination of aniline to bentonite. The exothermic DTA features at 507, 684, and 725°C indicate the release of both the clusters and the decomposed fragments of the aniline-clay composite, and the highly stable carbonaceous residue, respectively. The basal difference by ～1.0 nm and the much smaller surface area (33.8 m²/g) than that of the nonintercalated bentonite (129.2 m²/g) prove the presence of the tilted aniline species between the interlamellar grooves of the bentonite framework.     

Christopher Longuet-Higgins, 1923 to 2004

The structure, harmonic vibrational frequencies, dissociation energies with respect to possible fragmentation pathways, dipole moment, natural bond orbital (NBO) partial atomic charges and time-dependent density functional theory (TD-DFT) excitation energies for the novel molecule periodane, FBeCNLiOB, and three structural analogues were computed using density functional theory (DFT). Two isoelectronic analogues (FBeCNLiNC and FBeBOLiOB) result from the replacement in periodane of the BO fragment with the CN fragment and vice versa, while the third, called hydroperiodane, is formed by replacing the F atom of periodane with a H atom. These three species are predicted to have a stable structural motif based on that of the theoretically predicted planar global minimum of the periodane molecule.     

Simultaneous species and sex identification of silkworm pupae using hyperspectral imaging technology

To obtain high-quality raw silk and improve the economic values of sericulture industry, sex needs to be discriminated first before cross-breeding. Much work has been reported about sex identification. However, to realize automatic separation of silkworm pupae, the species also needs to be classified, which no research has ever explored. Hence, this paper studied the feasibility of visible and near-infrared hyperspectral imaging technology to identify the species and sex of silkworm pupae. 288 hyperspectral images of silkworm pupae were collected and the average spectra were extracted from the region of interest, around the tail region of silkworm pupae. Successive projection algorithm was served as a variable selection method to choose the optimal wavelengths from the full spectra. At the same time, principal component analysis was used to choose the characteristic images. Then, the gray-level co-occurrence matrix was implemented on the first three principal component images (accounted for 99.05% of the total variances) to extract 48 textural features. Partial least squares discriminant analysis and support vector machine models were built, respectively, based on the spectral data, textural data and fusion data that included spectral and textural data, in which the support vector machine model based on the fusion data, gave the best species and sex identification result with an accuracy of 95.83%. It demonstrated that the hyperspectral imaging technology could be a new and nondestructive method to replace the manual work.     

Dehydration and recrystallization of radiation-damaged titanite under thermal annealing

Abstract

Dehydration of oriented sections of a radiation-damaged titanite crystal, CaTiSiO₅, at temperatures up to 1500K was analysed using infrared spectroscopy. The IR spectra of the untreated sample show only a very weak orientational dependence. The absence of sharp absorption peaks at wave number near 3486 cm^?1 in metamict titanite shows that the local environmental configurations of OH species in the metamict titanite differ strongly from that of crystalline titanite. The OH spectra of radiation-damaged titanite can be decomposed into two components: the first component shows anisotropic and sharp spectral features while the second component consists of a broad spectral feature like those observed in disordered silica glasses. It is proposed that the first component is related to the crystalline part of the titanite sample while the second is from the defected and disordered part which suffered strong radiation damage. With increasing annealing temperature, a decrease in the broad absorption between 2500 and 3200 cm^?1 is accompanied by a recovery of sharp IR bands near 3486 cm^?1 which display the same orientational dependence as undamaged single crystals. Annealing the sample at 1000K leads to the line profiles and orientational dependence of the main OH stretching bands near 3486cm^?1 that are virtually identical with those of crystalline, undamaged titanites. At temperatures above 1500 K, the crystal starts to melt and the orientational dependence of the IR absorption is destroyed. The recrystallization processes are quantified and discussed in terms of a percolation behaviour of amorphous and crystalline titanite. It is proposed that hydrogen transport is strongly enhanced during recrystallization.     

Plasmas for medicine

Plasma medicine is an innovative and emerging field combining plasma physics, life science and clinical medicine. In a more general perspective, medical application of physical plasma can be subdivided into two principal approaches. (i) “Indirect” use of plasma-based or plasma-supplemented techniques to treat surfaces, materials or devices to realize specific qualities for subsequent special medical applications, and (ii) application of physical plasma on or in the human (or animal) body to realize therapeutic effects based on direct interaction of plasma with living tissue. The field of plasma applications for the treatment of medical materials or devices is intensively researched and partially well established for several years. However, plasma medicine in the sense of its actual definition as a new field of research focuses on the use of plasma technology in the treatment of living cells, tissues, and organs. Therefore, the aim of the new research field of plasma medicine is the exploitation of a much more differentiated interaction of specific plasma components with specific structural as well as functional elements or functionalities of living cells. This interaction can possibly lead either to stimulation or inhibition of cellular function and be finally used for therapeutic purposes. During recent years a broad spectrum of different plasma sources with various names dedicated for biomedical applications has been reported. So far, research activities were mainly focused on barrier discharges and plasma jets working at atmospheric pressure.     

Wood species identification using feature-level fusion scheme

In this paper, we propose a robust wood species identification scheme by using a feature-level fusion scheme. First, a novel wood feature acquirement system is devised, which can get the curve of 1D wood spectral reflectance ratio and the 2D wood surface color image. Second, the 4 wood color features, the 4 principal texture features, the 4 secondary texture features and the 4 spectral features are established, respectively. Third, a fuzzy BP neural network is proposed to perform the classification work, which consists of 4 sub-networks based on the color feature, texture feature and spectral feature. We have experimentally proved that this scheme improves the mean recognition accuracy to approximately 90% for 5 wood species. Moreover, our feature-level fusion scheme is superior to the recognition schemes which use color feature and texture feature.     

Temperature's optical tomography diagnosis of arc plasma jet flowing into air

An argon arc jet plasma flowing into air is chosen as a practical example to study the multiple species jet plasma's optical computerized tomography (OCT) diagnosis. The refractive index models of the pure argon and the multiple species arc plasmas are supplied. On the basis of which, the temperature reconstruction model of the multiple species arc plasma is further derived. By theoretical calculation, the effect of mixed air on the refractive index is given. For the sake of better proving the effect of directly omitting the mixed air on flow field's temperature reconstruction from the refractive index, a simulated experiment is supplied. Finally, the condition, which can be adopted to estimate that whether the pure argon arc plasma refractive index model still can be used as the temperature reconstruction model of the argon arc plasma jet flowing into air, is proposed.     

Surface enhanced Raman spectroscopic investigation of orchil dyed wool from Roccella tinctoria and Lasallia pustulata

In this work Raman spectroscopic techniques have been utilized to characterize the vibrational spectral features of orchil dyed wool samples. Specifically, it is noted by surface enhanced Raman spectroscopy that wool dyed purple with two historically used orchil species (Roccella tinctoria and Lasallia pustulata) show spectral differences possibly owing to their specific dye‐precursor constituents. The additional natural dyestuff woad (Isatis tinctoria L.) overdyeing the R. tinctoria orchil dyed wool is a further challenge when distinguishing the mixed dye components given by the co‐adsorption of the dyestuffs as permitted by the selection rules of surface enhanced Raman spectroscopy. Furthermore, the effects of dilution of the L. pustulata species in its spectral detection have been assessed along with the evaluation of subsequent lichen extract boiling before dyeing which resulted in the detection of a degraded form of the orchil dye. Proof of concept included the surface enhanced Raman spectroscopy (SERS) investigation of a purple dyed tapestry (XVI century) which permitted an aged orchil dye to be determined. This contribution utilizes SERS as a fast, reproducible and specific method for both orchil dye detection and alteration induced by degradation. Copyright © 2014 John Wiley & Sons, Ltd.     

Plasma Applications: A Dermatological View

The ability to produce cold plasma at atmospheric pressure conditions was the basis for the rapid growth of plasma related application areas in biomedicine. Plasma comprises a multitude of active components such as charged particles, electric current, UV radiation, and reactive species which can act synergistically. The antiitch, antimicrobial, and anti‐inflammatory effect was already demonstrated in in vivo and in vitro experiments and until now no resistance of pathogens against plasma treatment was observed. The combination of the different active agents and their broad range of positive effects on various diseases, especially easily accessible skin diseases, render plasma quite attractive for applications in medicine. Hence, plasma medicine as an independent and promising medical field has been emerged recently. For medical applications two different types of cold plasma are suitable; indirect (plasma jet, plasma torch) and direct plasma sources (dielectric barrier discharge ‐ DBD). So far, no standards and norms are defined for any of these plasma sources. Also, no convenient criteria for standardization of the quality rating of plasma in the view of dermatological applications exist. Although various cold plasma studies have been performed the results are hardly comparable, as physical parameters of the plasma devices, experimental conditions, and organisms used vary greatly. Therefore, standardized risk analyses are necessary for the assessment of different plasma sources. In this review two plasma sources are described and possible risk factors are discussed to estimate the safety of plasma used as a therapeutic tool in dermatology. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Fluorescence Microscopy and Flow Cytofluorometry of Reactive Oxygen Species

Abstract

The effects of reactive oxygen species on cell function and health have driven the development of numerous detection methodologies to assess oxidative stress. In this article, we review the detection of reactive oxygen species by fluorescence microscopy and flow cytofluorometry over the last seven years. Emphasis is placed on the variety of sample matrices analyzed and the diverse biomedical questions and oxidative stress mediated diseases that benefit from the information provided by these fluorescence-based analytical techniques.