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91.
The effects of gap width on the transmission coefficient of vacuum-ultraviolet light through submicrometer-period, freestanding transmission gratings are reported. Results from computations and an analytical waveguide model are shown to be consistent with experimental measurements. These results show that thin gratings with narrow gaps and thick gratings with wide gaps are equally effective at eliminating 121.6-nm radiation. The thin gratings with the narrow gaps have the advantage of better attenuation of shorter-wavelength radiation than the thick gratings with the larger gaps. 相似文献
92.
Hildo J. Lamb A. van der Laarse B. M. Pluim H. P. Beyerbacht J. Doornbos E. E. van der Wall A. de Roos 《Magma (New York, N.Y.)》1998,6(2-3):168-170
4. Conclusions Diastolic LV function and myocardial HEP metabolism are impaired only when LVH is caused by permanent pressure or volume overload,
and not by a temporary increase in cardiac workload during part of the day as in elite athletes. Therefore, training-induced
and pressure/volume-overload-induced LVH seem to represent different phenotypes of LVH, possibly related to genetic reprogramming
which only occurs during permanent cardiac overload [17]. Moreover, there is an association between impaired LV diastolic
function and altered myocardial HEP metabolism in patients with hypertension and in patients with aortic valve disease. Finally
we did not find a correlation between myocardial HEP metabolism and LV mass in any of the groups studied. The latter indicates
that LVH should be regarded as an epiphenomenon to cardiac overload, and not as a primary factor causing abnormal HEP metabolism. 相似文献
93.
94.
The aim of this study was to gauge the effect of an artificially established flora, unnatural for mice, on the induction of oral candidosis in mice. Four groups of BALB/c mice were compared; conventional Candida albicans-free mice, "germ-free" mice which had been inoculated with Candida-free human saliva, germ-free mice which had been exposed to a cocktail of Streptococcus mitis, S. sobrinus and S. sanguis, and uncontaminated germ-free mice. After exposure to C. albicans via drinking water, the four groups of mice were killed and their oral cavities examined for candidal growth and oral lesions. Conventional mice yielded significantly less candidal growth and exhibited significantly fewer oral lesions than the other three groups. Candidal lesions in the two groups of contaminated germ-free mice were significantly fewer than in the uncontaminated germ-free mice. The latter exhibited extensive candidal lesions with little inflammatory infiltrate. It is concluded that mice with human oral micro-organisms have some resistance against candidal infection albeit at a reduced level, that mice with natural oral flora are highly resistant, and that germ-free mice are extremely susceptible to C. albicans infection. 相似文献
95.
ES van Waalwijk van Doorn AH Meier AW Ambergen RA Janknegt 《Canadian Metallurgical Quarterly》1996,23(3):345-371
This article elucidates the clinical applicability and state of the art of ambulatory urodynamics. Ambulatory urodynamics have evolved into practical investigations like EAC, HFM, and EAC combined with renal pelvimetry. EAC has been shown to be the method of preference if detrusor overactivity is involved. Conventional filling cystometry has proved to be an unreliable way to exclude detrusor instability. De novo instability after suspension surgery often indicates that an existing detrusor overactivity was not identified preoperatively. EAC including flowmetry has shown considerable variance in obstructive and contractility parameters in males with LUTS indicative for BPH. This raises doubt whether the clinical flow analysis is the suitable "gold standard" as advocated by the ICS. For a real break through of EAC, less complex automatic analysis is necessary. HFM is a newer method within the range of ambulatory urodynamic tests. It has not yet been completely evaluated. But, because the technique is analogous to the office flowmetry, noninvasive and very well accepted by the patients, it is expected to be widely used. This expectation is strengthened by the fact that HFM seems to show individual therapeutic efficacy of drugs, such as alpha-blockers. As a research tool to evaluate efficacy, it is far more powerful than conventional methods because of the reduction of within-patient standard deviation to about 10%. Finally, EAC combined with pelvimetry offers a promising method for the clinical evaluation of a combined dysfunction of upper and lower urinary tract. 相似文献
96.
G.-J. Meerkerk R.J.J.M. van den Eijnden I.H.A. Franken H.F.L. Garretsen 《Computers in human behavior》2010
Aim of the present study was to examine whether the personality correlates sensitivity to reward and to punishment, and impulsivity predict compulsive internet use (CIU). Furthermore, the predictive value of these personality correlates was compared to the predictive value of factors relating to psychosocial wellbeing. The results showed that particularly rash spontaneous impulsivity predicts CIU and that this personality factor is more important than psychosocial wellbeing factors. Sensitivity to reward, which is supposed to play a role in craving processes associated with substance abuse and eating disorders, could not be related to CIU. The data suggest that internet users who are characterized by an impulsive personality feature, are less able to control their use of the internet, which makes them more vulnerable to develop CIU. 相似文献
97.
B.A. Wols J.A.M.H. Hofman W.S.J. Uijttewaal L.C. Rietveld J.C. van Dijk 《Environmental Modelling & Software》2010,25(4):573-582
Computational Fluid Dynamics combined with a particle tracking technique provides valuable information concerning residence times and contact times in chemical reactors. In drinking water treatment, for example an accurate estimation of the disinfection is important to predict the microbial safety. Ozone contactors are widely used for disinfection, but the complex geometry of the system causes suboptimal hydraulics and requires optimizations of the flow. This results in a lower ozone dosage, which may reduce the formation of unwanted disinfection-by-products and the consumption of energy. To that end disinfection needs to be calculated precisely, accounting for the complex hydraulics. Several calculation methods estimating the disinfection performance of ozone contactors were evaluated using Computational Fluid Dynamics. For an accurate disinfection prediction, the full distribution of ozone exposures (CT values) is needed, only a mean CT value or residence time distribution provides insufficient information for an accurate disinfection prediction. Adjustments to the geometry of the ozone contactor that reduce the short-circuit flows resulted in an increase in disinfection capacity, whereas the mean CT value remained the same. A sensitivity analysis with respect to the kinetics was conducted. The gain in disinfection capacity obtained by optimizing the hydraulics was significant for typical values used in practice. 相似文献
98.
Marcello La Rosa Hajo A. Reijers Wil M.P. van der Aalst Remco M. Dijkman Jan Mendling Marlon Dumas Luciano García-Bañuelos 《Expert systems with applications》2011,38(6):7029-7040
Business process models are becoming available in large numbers due to their widespread use in many industrial applications such as enterprise and quality engineering projects. On the one hand, this raises a challenge as to their proper management: how can it be ensured that the proper process model is always available to the interested stakeholder? On the other hand, the richness of a large set of process models also offers opportunities, for example with respect to the re-use of existing model parts for new models. This paper describes the functionality and architecture of an advanced process model repository, named APROMORE. This tool brings together a rich set of features for the analysis, management and usage of large sets of process models, drawing from state-of-the art research in the field of process modeling. A prototype of the platform is presented in this paper, demonstrating its feasibility, as well as an outlook on the further development of APROMORE. 相似文献
99.
Tom Oomen Author Vitae Jeroen van de Wijdeven Author Vitae Author Vitae 《Automatica》2009,45(4):981-1666
Iterative Learning Control (ILC) is a control strategy to improve the performance of digital batch repetitive processes. Due to its digital implementation, discrete time ILC approaches do not guarantee good intersample behavior. In fact, common discrete time ILC approaches may deteriorate the intersample behavior, thereby reducing the performance of the sampled-data system. In this paper, a generally applicable multirate ILC approach is presented that enables to balance the at-sample performance and the intersample behavior. Furthermore, key theoretical issues regarding multirate systems are addressed, including the time-varying nature of the multirate ILC setup. The proposed multirate ILC approach is shown to outperform discrete time ILC in realistic simulation examples. 相似文献
100.
M.T. Wynn H.M.W. Verbeek W.M.P. van der Aalst A.H.M. ter Hofstede D. Edmond 《Information and Software Technology》2009,51(6):1010-1020
As the need for concepts such as cancellation and OR-joins occurs naturally in business scenarios, comprehensive support in a workflow language is desirable. However, there is a clear trade-off between the expressive power of a language (i.e., introducing complex constructs such as cancellation and OR-joins) and ease of verification. When a workflow contains a large number of tasks and involves complex control flow dependencies, verification can take too much time or it may even be impossible. There are a number of different approaches to deal with this complexity. Reducing the size of the workflow, while preserving its essential properties with respect to a particular analysis problem, is one such approach. In this paper, we present a set of reduction rules for workflows with cancellation regions and OR-joins and demonstrate how they can be used to improve the efficiency of verification. Our results are presented in the context of the YAWL workflow language. 相似文献