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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
    Refractive Index Measurements in Qualitative Organic Microanalysis (1939)
    s.l. : American Chemical Society
    Industrial and engineering chemistry 11 (1939), S. 403-403 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ac50135a025
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  • 4
    Electronic Resource
    Electronic Resource
    CORRESPONDENCE Deposition of Gold on Fabrics (1939)
    s.l. : American Chemical Society
    Industrial & engineering chemistry 31 (1939), S. 1186-1186 
    Details
    ISSN: 1520-5045
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ie50357a030
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  • 5
    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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  • 6
    Electronic Resource
    Electronic Resource
    Cyclomorphosis in natural populations of Oscillatoria redekei Van Goor (1975)
    Oxford, UK : Blackwell Publishing Ltd
    Freshwater biology 5 (1975), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Evidence is presented of a regular seasonal variation in the filament length of Oscillatoria redekei Van Goor in Lough Neagh. This cycle is not in phase with the seasonal changes of the biomass of the species, but seems to occur in step with the nutrient concentrations. Some possible mechanisms of filament replication are discussed and evidence is presented that mechanical forces are not effective in breaking filaments. The ecological significance of cyclomorphosis in this species is difficult to establish.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2427.1975.tb00141.x
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  • 7
    Electronic Resource
    Electronic Resource
    Changes in phytoplankton physiology and morphology in response to dissolved nutrients in Lough Neagh, N. Ireland (1979)
    Oxford, UK : Blackwell Publishing Ltd
    Freshwater biology 9 (1979), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SUMMARY. Cell phosphorus and anthrone-reactive carbohydrate contents were measured over a 6-month period in the phytoplankton of Lough Neagh, N. Ireland. When all the soluble reactive phosphorus had disappeared from the water column, cell phosphorus contents began to decrease, reaching a minimum value of 0.4% ash-free dry weight. At this time, cell carbohydrate contents greatly increased and phosphorus sorption assays showed rapid uptake of orthophosphate. Following a presumed sediment phosphorus release, cell carbohydrate and phosphorus uptake rate decreased greatly and there was a subsequent increase in cell phosphorus content to 1.6% ash-free dry weight. As the cell phosphorus content declined, blue-green algal filaments became progressively shorter. On the basis of these responses it is likely that phosphorus limitation occurred over a 4-week period.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2427.1979.tb01494.x
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  • 8
    Electronic Resource
    Electronic Resource
    Sinking rates of planktonic diatoms in an unstratified lake: a comparison of field and laboratory observations (1984)
    Oxford, UK : Blackwell Publishing Ltd
    Freshwater biology 14 (1984), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SUMMARY. 1. Natural population sinking rates were calculated by fitting an exponential regression to 6 years’observations on declining crops of Melosira italica subarctica O. Müll. and Stephanodiscus astraea (Ehr.) Grun.2. Losses were described by an exponential model which yielded still water sinking rates of 0.86 md−1 for M. italica and 0.45md−1 for S. astraea.3. Laboratory measurements of the sinking rate of natural populations showed that the rate increased abruptly from less than 0.2 m d−1 in growing populations to 0.4 m d−1 after silica depletion.4. The measured sinking rate of S. astraea agreed well with that observed in the field. Where as populations of M. italica appeared to sink more quickly in the lake than could be accounted for by laboratory observations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2427.1984.tb00182.x
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  • 9
    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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  • 10
    Electronic Resource
    Electronic Resource
    Calculation of Minimum Reflux in Distillation Columns (1950)
    s.l. : American Chemical Society
    Industrial & engineering chemistry 42 (1950), S. 871-876 
    Details
    ISSN: 1520-5045
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ie50485a034
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