Effects of Preform Shear on Tensile Properties of a Woven C/SiC Composite

This article addresses effects of weave defects in an angle‐interlock C‐fiber preform on the tensile properties of the resulting fully processed C‐fiber/SiC‐matrix composite. For this purpose, a preform was intentionally sheared in a controlled manner after weaving. The resulting distortions were quantified by analyzing high‐resolution images of the preform surface after the first step of matrix processing, while the tows were still clearly visible. Comparisons are made of tensile test results on specimens cut from this composite panel and from a pristine panel in select loading orientations. Strain maps obtained by digital image correlation are used to identify local strain variations that are attributable to weave defects. The results are discussed in terms of: (i) the shear‐normal coupling that arises in loading orientations of present interest, and (ii) the geometric effects of tow misalignment on tow continuity along the specimen gauge length. The composite is found to perform in a robust manner, in the sense that the tensile properties are not sensitive to the presence of the defects.     

Authentication of the anti-tumor herb Baihuasheshecao with bioactive marker compounds and molecular sequences

Baihuasheshecao (Hedyotis diffusa), a Chinese herb for cancer treatment, is frequently adulterated by a related species Hedyotis corymbosa. DNA sequencing of the complete internal transcribed spacer region was applied to differentiate H. diffusa from H. corymbosa and other closely related species. The molecular data showed that four out of seven herb samples of Baihuasheshecao were adulterants. Chemical analyses by TLC and HPLC were used to authenticate H. diffusa and H. corymbosa. Two marker compounds were identified exclusively in H. diffusa: 6-O-(E)-p-coumaroyl scandoside methyl ester (compound 1) and 10(S)-hydroxypheophytin a (compound 2). Both compounds showed moderate anti-proliferation effect on PC3 human androgen-independent prostate cancer cells, while compound 2 also showed strong anti-proliferation effect on LNCaP human androgen-sensitive prostate cancer cells. Accordingly, these bioactive marker compounds could be applied to verify the authenticity and assess the quality of Baihuasheshecao.     

Edge of Empire: Transnationalism and identity in Wellington,New Zealand,ca . 1860- ca . 1920

Aspects of transnationalism and identity in the period from the 1860s to the mid 1920s, which set in motion a form of globalization related to empire, are focused upon. The notion of 'regimes of representation' is adapted as a broad conceptual framework for exploring the role of colonial directories in establishing the identity of metropolitan commercial culture in Wellington, New Zealand. This outpost of empire is examined through a detailed analysis of the images presented in a series of directories by Kelly's and Wise. These reveal how British commerce established a strong and lasting identity in the colony through a variety of 'acts of representation'. It is concluded that colonial directories are a worthwhile but neglected source for exploring the geographies of empire.     

Sex pheromone of aPlanotortrix excessana sibling species and reinvestigation of related species

The sex pheromone of aPlanotortrix excessana sibling species was investigated. Females were found to produce eight potential pheromone components: dodecyl acetate, tetradecyl acetate (14OAc). (Z)-5-tetradecenyl acetate (Z5-14OAc), (Z)-7-tetradecenyl acetate (Z7-14OAc), (Z)-9-tetradecenyl acetate, hexadecyl acetate, (Z)-7-hexadecenyl acetate, and (Z)-9-hexadecenyl acetate. When these compounds were bioassayed using field-trapping and wind-tunnel techniques, only 14OAc,Z5-14OAc, andZ7-14OAc were found to be behaviorally active. The sex pheromone glands of females of other species including,Planotortrix MBS,Planotortrix M,P. notophaea, Ctenopseustis servana, and aC. obliquana sibling species, were also found to containZ5-14OAc orZ7-14OAc, singly or in combination. In the case ofPlanotortrix M, the addition ofZ7-14OAc to the previously identified sex pheromone blend ofZ5-14OAc and 14OAc was found to increase trap captures of male moths of this species. Thus in these New Zealand species (and in some Australian species),Z5-14OAc andZ7-14OAc appear to be utilized in combination in pheromonal communication just as (Z)-11-tetradecenyl acetate and (E)-11-tetradecenyl acetate are used by many species of Holarctic Tortricidae in the tribe Archipini.Lepidoptera: Tortricidae: Tortricinae.     

Chilled ceilings and displacement ventilation

Displacement ventilation and chilled ceiling systems have been promoted as being ‘greener’ alternatives to other common forms of air conditioning system. They have been viewed by some of the building services industry as a welcome departure from the traditional ‘North American’ systems of air conditioning most frequently adopted to date, and could be viewed as a more suitable alternative for use in the moderate climatic conditions of the UK.This paper reviews some of the authors' recent and current work on the performance of these systems in office environments.     

Electrical and mechanical behaviors of carbon nanotube‐filled polymer blends

Four carbon nanotube (CNT)‐filled polymer blends, i.e., CNT‐filled polyethylene terephthalate (PET)/polyvinylidene fluoride, PET/nylon 6,6, PET/polypropylene, and PET/high‐density polyethylene blends, have been injection‐molded and characterized in terms of their microstructures, electrical conductivities, and mechanical properties. The distribution of CNTs in the polymer blends has been examined based on their wetting coefficients and minimization of the interfacial energy. The electrical conductivity and mechanical properties have been related to the cocontinuous polymer blends, the conductive path formed by CNTs, the CNT distribution, and the intrinsic properties of the constituent polymers. It is found that to obtain a CNT‐filled polymer composite with both high electrical conductivity and good mechanical properties, it is preferred that most CNTs distribute in one polymer phase, while the other polymer phase(s) remain neat. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 477–488, 2006     

The comparison of electroencephalograms recorded before and after electrical stunning of cattle

Electroencephalograms (EEGs) were recorded before and after ‘head-only’ electrical stunning of adult cattle. Epochs of 8·5 s duration derived from the pre-and the post-stun EEG signals were compared for differences in scale and frequency.

The frequency structures of two selected epochs from the one animal were evaluated using the periodogram ordinates derived by calculating the Fast Fourier Transform. The comparison of the two pre-stun epochs indicated that, within the one animal, the pre-stun EEG signal had a consistent frequency pattern. Similarly, a comparison of two post-stun epochs indicated that the post-stun EEG signal also had a consistent frequency pattern. The comparison of pre- and post-stun epochs indicated a consistent increases in amplitude after stunning. Additionally, after stunning, there was an increase in the power of frequencies in the range 4–8 Hz and a decrease in the power of certain frequencies in the range 15–25 Hz. Although there was considerable animal-to-animal variation it was demonstrated that electric stunning produced definable changes in the EEG signal.     

Free and glycosylated sterol bioaccumulation in developing Cycas micronesica seeds

The bioaccumulation of free and glycosylated forms of stigmasterol and β-sitosterol were determined from Cycas micronesica K.D. Hill seeds throughout seed ontogeny. Per-seed pool of the four compounds increased linearly from 2 to 24 months, indicating no developmental period elicited a major shift in the rate of bioaccumulation. The slopes were not homogeneous, signifying a change in relative sterol profile concomitant with seed maturation. This shift was in favour of the glucosides, as their rate of accumulation exceeded that of the free sterols. Stigmasterol content exceeded that of β-sitosterol, but ontogeny did not influence the ratio of these dominant sterols. The quantity and quality of sterol exposure during consumption of foods prepared from gametophytes by humans is strongly influenced by age of harvested seeds. Results are critical for a further understanding of the link between human neurodegenerative diseases and historical consumption of foods derived from the seed gametophyte tissue.     

Simulation and optimization of retention in ion chromatography using virtual column 2 software

A new software package, Virtual Column 2, is described for the simulation and optimization of the separation of inorganic anions by ion chromatography (IC). The software uses a limited amount of experimental retention data acquired according to a correct experimental design to predict retention times for analytes over a designated search area of eluent compositions. The experimental retention data are used to solve a new retention model, called the linear solvent strength model, empirical approach (LSSM-EA), which then enables prediction of retention times for all eluent compositions in the search area. The theoretical development of LSSM-EA and the processes used for solving the equations are discussed. Virtual Column 2 can be used for eluents containing one or two competing ions, and the software contains retention databases for up to 33 analytes on the Dionex AS9A-HC, AS4A-SC, and AS14A analytical columns with carbonate-bicarbonate eluents and the Dionex AS10, AS15, and AS16 analytical columns with hydroxide eluents (results for the AS10 and AS15 columns are not discussed in the present study). Virtual Column 2 has been evaluated extensively and is shown to give predicted retention times that in most cases agree with experimentally determined data to within 5%. The software has uses in practical IC method development, education and training in IC, and refinement of existing IC methodology. A free version of this program is available by download at www.virtualcolumn.com.