Assessment of pitting corrosion in bare and passivated (wet scCO2-induced patination and chemical passivation) hot-dip galvanized steel samples with SVET,FTIR, and SEM (EDS)

In this study, the local electrochemical activity of untreated and passivated (natural or chemical passivation) zinc specimens was observed during immersion in a 0.1-M NaCl solution. The localized anodic activity during the exposure, measured with the scanning vibrating electrode technique, was linked to zinc dissolution by the pitting corrosion mechanism. It was correlated to specific corrosion products characterized by Fourier transmission infrared (FTIR) microscopy. FTIR molecule maps were produced from individual pitting corrosion sites (100–200 µm in width). With argon ion beam milling and latest energy-dispersive X-ray spectroscopy (EDS) technology, element maps with a high spatial resolution (≪100 nm) were recorded from abrasion- and beam-sensitive corrosion products, showing a residual layer structure. This study demonstrates the capability of FTIR mapping, cross-section polishing, and state-of-the-art scanning electron microscopy imaging, and EDS element mapping to produce high-resolution elemental, molecular, and visual information about pitting corrosion mechanisms on a hot-dip galvanized steel sample.     

The Effects of the Alkaloid Tambjamine J on Mice Implanted with Sarcoma 180 Tumor Cells

The tambjamines are a small group of bipyrrolic alkaloids that, collectively, display a significant range of biological activities including antitumor, antimicrobial and immunosuppressive properties. The key objective of the present study was to undertake preclinical assessments of tambjamine J (T-J) so as to determine its in vivo antitumor effects. To that end, sarcoma 180 cells were transplanted in mice and the impacts of the title compound then evaluated using a range of protocols including hematological, biochemical, histopathological, genotoxic and clastogenic assays. As a result it was established that this alkaloid has a significant therapeutic window and effectively reduces tumor growth (by 40 % and 79 % at doses of 10 and 20 mg/kg/day, respectively). In this regard it displays similar antitumor activity to the anticancer agent cyclophosphamide and alters animal weight in an analogous manner.     

Study of nylon 6 and poly(propylene oxide) blends by thermal measurements and carbon-13 NMR high resolution solid-state

Samples of Nylon 6/poly(propylene oxide), with poly(propylene oxide) (PPO) content varying up to 35%, have been examined using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and nuclear magnetic resonance (NMR) carbon-13 at solid-state. Carbon-13 spectra were measured by cross-polarization (CP), magic angle spinning (MAS), and high-power hydrogen decoupling (HPHD). The variation contact time experiment and MAS technique were also determined. The data are discussed in terms of compatibility and plasticization of the samples. © 1995 John Wiley & Sons, Inc.     

A 3D-QSAR Study of Analogs of (Z)-5-Decenyl Acetate, A Pheromone Component of the Turnip Moth, Agrotis segetum

The methodology of three-dimensional quantitative structure-activity relationships (3D-QSAR) has been employed to develop a quantitative model for the relationship between single-cell activities for a large set of analogs of (Z)-5-decenyl acetate, a pheromone component of the turnip moth, Agrotis segetum, and the structural characteristics of the analogs. The method of partial least squares (PLS) projections to latent structures has been used to delineate the relationships between measured activities and chemical structures. The training set includes 42 compounds, and a test set of seven molecules has been employed to assess the predictivity of the model. The model derived is able to calculate the activities of the seven test compounds with an average unsigned error of 0.3, close to the experimental error. Contour maps of regression-like coefficients from transformed PLS components display electronic and nonbonded features of high importance for the observed variation in the activities of compounds in the training set. The contours for the nonbonded (van der Waals) field support previous conclusions that the interaction between the pheromone component and its receptor is characterized by a high steric complementarity.     

Particles from fires—a screening of common materials found in buildings

Small combustion generated particles are known to have a negative impact on human health and on the environment. In spite of the huge amount of particles generated locally in a fire accident, few investigations have been made on the particles from such fires. In this article, 24 different materials or products, typically found in buildings have been exposed to burning conditions in order to examine their particle generating capacity. In addition, a carbon fibre based composite material was tested in order to investigate if asbestos‐resembling particles could be generated in a fire situation. The majority of the experiments were performed in the small‐scale cone calorimeter, and some further data were collected in intermediate scale (SBI) and full scale (room‐corner) tests. Additional testing of the composite material was made in a small‐scale tubular reactor. The amount of particles and particle size distributions were measured by the use of a low‐pressure impactor and particle aerodynamic diameter sizes from 30 nm to 10 μm were measured. The results from the project show that the yield of particles generated varied significantly between materials but that the shape of mass and number size distributions were very similar for all the materials tested. The maximum amount of particles was obtained from materials that did not burn well (e.g. flame retarded materials). Well‐burning materials, e.g. wood materials, tend to oxidize all available substances and thereby minimize the amount of particles in the smoke gas. It was found that asbestos‐resembling particles could be produced from under‐ventilated combustion of the composite material tested. Copyright © 2003 John Wiley & Sons, Ltd.     

Cyberbullying on social networking sites: A literature review and future research directions

Cyberbullying on social networking sites is an emerging societal issue that has drawn significant scholarly attention. The purpose of this study is to consolidate the existing knowledge through a literature review and analysis. We first discuss the nature, research patterns, and theoretical foundations. We then develop an integrative framework based on social cognitive theory to synthesize what is known and identify what remains to be learned, with a focus on the triadic reciprocal relationships between perpetrators, victims, and bystanders. We discuss the key findings and highlight opportunities for future research. We conclude this paper by noting research contributions and limitations.     

Socio-familial characteristics of black male heroin addicts and their nonaddicted friends

To determine whether family, peer, and school variables are associated with divergent heroin-use patterns or career outcomes, we interviewed 183 black male heroin addicts, experimenters, and non-heroin users from Chicago's south side. While subgroup differences on socio-familial variables generally were not statistically significant, we did observe a number of trends in the expected direction. For example, addicts were more likely than experimenters or nonusers to come from broken homes, to have friends who were involved in serious types of drug use and other illegal activities, and to drop out of high school. At the same time, the pervasiveness of some of our measures of "social disharmony" across the sample suggest that, at least in some inner-city black neighborhoods, these patterns are perhaps becoming the norm.     

Introduction of methyl groups to acetate substituted chain of (Z)-5-decenyl acetate,a pheromone component of turnip moth,agrotis segetum: synthesis,single-sensillum recordings,and structure-activity relationships

Methyl-substituted analogs of (Z)-5-decenyl acetate, a pheromone component of the turnip moth,Agrotis segetum, have been synthesized and studied by electrophysiological single-sensillum recordings and molecular mechanics calculations [MM2(85)]. The analogs are monomethyl substituted in the 2, 3, 4, and 5 positions and geminally dimethyl substituted in the 2, 3, and 4 positions. The methyl groups have been employed as space probes to study the degree of steric complementarity between the acetate-substituted alkyl chain of the pheromone component and its receptor. The electrophysiological activities, interpreted in terms of a receptor interaction model, indicate significant steric repulsive interactions between the introduced methyl groups and the receptor. This implies a high degree of complementarity between the acetate-substituted alkyl chain of the natural pheromone component and its receptor.Schiff., Lepidoptera: Noctuidae.     

Determination of the vapor pressures of moth sex pheromone components by a gas chromatographic method

The vapor pressures of decyl acetate, five decenyl acetate isomers, (Z)-7-dodecenyl acetate, and (Z)-9-tetradecenyl acetate have been determined at three to six temperatures in the interval 25–45 °C by a gas Chromatographic method suitable for accurate measurements of the low vapor pressures of moth sex pheromone components at biologically relevant temperatures. The vapor pressure values at 30.5 °C are 3.80 Pa for decyl acetate, 4.08–5.40 Pa for the decenyl acetate isomers, 0.562 Pa for (Z)-7-dodecenyl acetate, and 0.094 Pa for (Z)-9-tetradecenyl acetate. The vapor pressures of the decenyl acetates show a small but significant dependence on the double bond position. Four of the compounds in this study, 10Ac,Z5–10Ac,Z7–12Ac, andZ9–14Ac have recently been identified as sex pheromone components of the turnip moth,Agrotis segetum. Large differences between the mole percentages of the component as found in liquid extracts of female abdominal tips and the corresponding mole percentages in the vapor phase are predicted.