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  • 1
    Electronic Resource
    Electronic Resource
    Microwave cavity spectrometer for process monitoring of ethylene oxide sterilization (1993)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 64 (1993), S. 103-108 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: This article reports a novel and simple cavity spectrometer for process monitoring of ethylene oxide sterilization, in which the source frequency, cavity resonant frequency, and gas absorption center frequency are asynchronous with respect to each other, thus, enabling sophisticated signal enhancement techniques to be employed without the need to engage the Stark effect. The operation of the device is such that the source frequency sweeps across a given range (F1 to F2) which contains one of the absorption peaks of the analyte gas (gases) of interest while the cavity resonant frequency Fr is oscillated within the profile of the absorption peak. Signal enhancement is achieved by adding a relatively small magnitude/high-frequency "dither'' signal to the source frequency sweep pattern. The salient information of the gas absorption due to the oscillation of the resonant frequency of the cavity is carried by the "dither'' signal and amplified and extracted by a series of tuned amplifiers and demodulators. Although the device is still at the initial design stage, a working prototype has been constructed in order to test the feasibility of the novel asynchronous modulation technique. This was achieved by successfully demonstrating that the device operates in an expected manner to within a standard error of 8.3%. It is believed that this error largely results from mechanical components. The significance of this error is greatly reduced when the spectrometer is operated in a large signal scanning mode as is the case when we apply the "power saturation'' technique to measure the concentration of ethylene oxide in the resonant cavity. This measurement showed that there is a good linear correlation between the output signal and the concentration of ethylene oxide gas (to within a standard error of 4%).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1144422
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  • 2
    Electronic Resource
    Electronic Resource
    Comparative solvolytic reactivity of bay-region diol epoxides derived from dibenz[a,j]anthracene and dibenzacridines (1990)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 112 (1990), S. 1177-1185 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00159a044
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  • 3
    Electronic Resource
    Electronic Resource
    Alignment of vorticity and scalar gradient with strain rate in simulated Navier–Stokes turbulence (1987)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 30 (1987), S. 2343-2353 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The alignment between vorticity and eigenvectors of the strain-rate tensor in numerical solutions of Navier–Stokes turbulence is studied. Solutions for isotropic flow and homogeneous shear flow from pseudospectral calculations using 1283 grid points have been examined. The Taylor Reynolds number is 83 or greater. In both flows there is an increased probability for the vorticity to point in the intermediate strain direction and at three-fourths of the sample points this strain is positive (extensive). This propensity for vorticity alignment with a positive intermediate strain is a consequence of angular momentum conservation, as shown by a restricted Euler model of the coupling between strain and vorticity. Probability distributions for intermediate strain, conditioned on total strain, change from a symmetric triangular form at small strain to an asymmetric one for large strain. The most probable value of the asymmetric distribution gives strains in the ratios of 3:1: −4. The evolution of the distribution from a symmetric to an asymmetric form as the strain magnitude increases is essentially the same in both flows, indicating a generic structure of intense turbulence. The alignment between the gradient of a passive scalar and eigenvectors of the strain-rate tensor for Prandtl numbers of 0.1, 0.2, 0.5, and 1.0 has also been studied. There is an increased probability for the scalar gradient to align in the most compressive strain direction, and the average gradient is larger when it is pointing in that direction. Estimates for the scalar dissipation from the turbulent kinetic energy, its dissipation, and the root-mean-square scalar value are in reasonable agreement with calculated scalar dissipation if no explicit Prandtl number dependence is used in the estimate. Statistical analysis of scalar dissipation conditioned on energy dissipation yields a power-law relation between conditioned mean values. Both simulated flows are found to obey the qualitative predictions of the Gurvich–Yaglom (lognormal) intermittency model. Energy and scalar intermittency exponents are estimated and compared to measured values.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.866513
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  • 4
    Electronic Resource
    Electronic Resource
    Bovine amelogenin message heterogeneity: alternative splicing and Y-chromosomal gene transcription (1992)
    s.l. : American Chemical Society
    Biochemistry 31 (1992), S. 8384-8388 
    Details
    ISSN: 1520-4995
    Source: ACS Legacy Archives
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/bi00150a036
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  • 5
    Electronic Resource
    Electronic Resource
    Structure of rel-(3R,3aS,7aS)-hexahydro-4,4-dimethoxy-3-(methylthio)-3-pentyl-2(3H)-benzo[b]furanone (1986)
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 42 (1986), S. 1587-1589 
    Details
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108270186091382
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  • 6
    Electronic Resource
    Electronic Resource
    Multilocus analysis of the fragile X syndrome (1988)
    Springer
    Human genetics 〈Berlin〉 78 (1988), S. 201-205 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A multilocus analysis of the fragile X (fra(X)) syndrome was conducted with 147 families. Two proximal loci, DXS51 and F9, and two distal loci, DXS52 and DXS15, were studied. Overall, the best multipoint distances were found to be DXS51-F9, 6.9%, F9-fra(X), 22.4%; fra(X)-DXS52, 12.7%; DXS52-DXS15, 2.2%. These distances can be used for multipoint mapping of new probes, carrier testing and counseling of fra(X) families. Consistent with several previous studies, the families as a whole showed genetic heterogeneity for linkage between F9 and fra(X).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00291662
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  • 7
    Electronic Resource
    Electronic Resource
    Identification of a new HLA-DPB1 allele (DPB1*5101) by oligotyping and nucleotide sequencing (1994)
    Springer
    Immunogenetics 40 (1994), S. 164-164 
    Details
    ISSN: 1432-1211
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00188183
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  • 8
    Electronic Resource
    Electronic Resource
    Host selectivity and the mediation of competition by the root hemiparasite Rhinanthus minor (1991)
    Springer
    Oecologia 86 (1991), S. 81-87 
    Details
    ISSN: 1432-1939
    Keywords: Competition ; Hemiparasitism ; Host selectivity ; Rhinanthus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Rhinanthus minor (Yellow-rattle) was grown in replacement series mixtures with Lolium perenne and Trifolium repens. The hemiparasitic interaction resulted in Relative Yield Totals (the sum of the yields in mixture relative to those in monoculture) considerably above 2. The hemiparasite caused a greater decrease in the yield of the legume and also performed better on the legume, indicating that T. repens was a better host for R. minor than L. perenne under the experimental conditions. When L. perenne and T. repens were grown in binary mixture with or without R. minor the hemiparasite affected considerably the competitive relationship between the two species by selectively parasitizing the legume. The effect of R. minor on competition between the two species was, however, dependent upon the nutrient status of the soil: the higher the level of soil nitrogen the fewer haustorial connections were made with T. repens and the less was the depression in its yield. In another series of experiments in which Festuca rubra, Holcus lanatus and L. perenne were grown in various binary mixtures with or without R. minor it was also shown that the yield of a preferred host was depressed to the advantage of a non-preferred host. It is suggested that the mediation of competition by the hemiparasite provides a mechanism by which it might affect the structure and diversity of plant communities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317393
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  • 9
    Electronic Resource
    Electronic Resource
    The role of the hemiparasitic annual Rhinanthus minor in determining grassland community structure (1992)
    Springer
    Oecologia 89 (1992), S. 62-68 
    Details
    ISSN: 1432-1939
    Keywords: Rhinanthus ; Hemiparasitism ; Species diversity ; Community structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Rhinanthus minor (yellow-rattle) is a widespread hemiparasitic plant of grassland habitats throughout Great Britain. It is usually considered to be indicative of species-rich grassland, but in a survey of 14 habitats throughout Britain it was found that R. minor at the time of flowering normally occupied relatively low-diversity patches within areas of high diversity as determined by the number of species, Simpson's Index and the Shannon-Wiener Index. Following the death of adult plants of R. minor in the summer it was shown that the pattern of species diversity changed such that by the time R. minor germinated in the following spring the differences between the areas containing and not containing R. minor were much less distinct. A perturbation experiment in which R. minor was removed from four sites indicated that the effect of the removal of R. minor on the development of community structure over the next year was to increase species diversity on three of the sites and decrease it on the fourth. Those species which responded to the removal of R. minor by an increase in abundance were shown to be preferred hosts. All three lines of evidence point to the fact R. minor has a significant effect on the species diversity of the communities in which it grows by selectively parasitizing components of the flora and modifying the competitive relationships between plants. However, as the communities generally responded to the removal of R. minor by an increase in diversity and as the general survey indicated that R. minor is generally associated with areas of low diversity it would appear that the plants which are selectively parasitized are generally not the competitive dominants in the community.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319016
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  • 10
    Electronic Resource
    Electronic Resource
    Relationships between the effects of insect herbivory and sheep grazing on seasonal changes in an early successional plant community (1987)
    Springer
    Oecologia 71 (1987), S. 245-253 
    Details
    ISSN: 1432-1939
    Keywords: Calcicolous grassland ; Herbivory ; Insects ; Plant succession ; Sheep
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effects of spring grazing by sheep and of natural levels of insect herbivory were studied in 1985 on a limestone field abandoned from arable land for four years. A split-plot design was adopted in which paddocks, arranged in Latin squares, were either left ungrazed or heavily grazed by sheep for ten days in April. Within each paddock plots were either sprayed regularly with Malathion-60 or untreated. Natural levels of insect herbivory, compared to the reduced levels in insecticide-treated plots, had effects of similar magnitude to those from the short burst of spring grazing. Many attributes of the grazed/insecticide-treated sward were either increased or decreased by a factor of two within a season. Both types of herbivore caused changes in the direction of plant succession as well as in its rate. Effects on early successional species were large and similar when caused by either type of herbivore. Effects on later successional species were often smaller, but also showed differences in the action of the two herbivore types, as did effects on sward height, species richness and total cover. The effects of sheep and insect herbivory were not always additive or in the same direction. The results suggest that manipulations of both mammal and insect herbivores may be powerful tools for directing changes in plant community composition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00377291
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