scholarly journals Post-test comparison of thermal-hydrologic measurements and numerical predictions for the in situ single heater test, Yucca Mountain, Nevada

1998 ◽  
Author(s):  
S. Ballard ◽  
N.D. Francis ◽  
S.R. Sobolik ◽  
R.E. Finley
Keyword(s):  
Yucca Mountain ◽  
Numerical Predictions ◽  
Post Test ◽  
Single Heater

scholarly journals The extreme runoff index for flood early warning in Europe

2014 ◽  
Vol 14 (6) ◽  
pp. 1505-1515 ◽  
Author(s):  
L. Alfieri ◽  
F. Pappenberger ◽  
F. Wetterhall
Keyword(s):  
Early Warning ◽  
Input Data ◽  
Weather Forecasting ◽  
Spatial Inhomogeneity ◽  
Optimal Timing ◽  
Numerical Predictions ◽  
In Situ Observations

Abstract. Systems for the early detection of floods over continental and global domains have a key role in providing a quick overview of areas at risk, raise the awareness and prompt higher detail analyses as the events approach. However, the reliability of these systems is prone to spatial inhomogeneity, depending on the quality of the underlying input data and local calibration. This work proposes a simple approach for flood early warning based on ensemble numerical predictions of surface runoff provided by weather forecasting centers. The system is based on a novel indicator, referred to as an extreme runoff index (ERI), which is calculated from the input data through a statistical analysis. It is designed for use in large or poorly gauged domains, as no local knowledge or in situ observations are needed for its setup. Daily runs over 32 months are evaluated against calibrated hydrological simulations for all of Europe. Results show skillful flood early warning capabilities up to a 10-day lead time. A dedicated analysis is performed to investigate the optimal timing of forecasts to maximize the detection of extreme events. A case study for the central European floods of June 2013 is presented and forecasts are compared to the output of a hydro-meteorological ensemble model.

A Novel Vibrating Ribbon Technique

2005 ◽  
Author(s):  
Jonathan H. Watmuff
Keyword(s):  
Test Section ◽  
Vibration Amplitude ◽  
Wave Amplitude ◽  
Separation Bubble ◽  
Wind Tunnel Test ◽  
Mean Flow ◽  
Test Plate ◽  
Numerical Predictions ◽  
The Mean

A novel vibrating ribbon apparatus is described that is active over the full span of a wind tunnel test section. The spanwise uniformity of the vibration amplitude and other ribbon characteristics are considered in detail. The height of each end of the ribbon above the test plate can be adjusted in situ, while the ribbon is vibrating and with flow in the test section, thereby allowing the response of the layer to be easily tuned. The growth of the wave amplitude downstream of the ribbon is shown to agree with numerical predictions. However, two or three wavelengths of development are required before the wave amplitude follows the predicted growth. The flow around an inactive ribbon is examined using a commercial CFD solver and features such as a miniature separation bubble just downstream of the ribbon are revealed. The distance required for the mean flow to recover from the disturbance introduced by the ribbon is greater when the ribbon is located further from the wall. The mean flow recovers to form a boundary layer that is slightly thicker than the undisturbed flow. Experimental measurements indicate that the distance required for the wave motions to follow predicted behavior is about 4 or 5 times larger than distance for recovery of the mean flow.

scholarly journals Comparative efficacy of a hydroxyapatite and a fluoride toothpaste for prevention and remineralization of dental caries in children

BDJ Open ◽  
2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Bennett T. Amaechi ◽  
Parveez Ahamed AbdulAzees ◽  
Dina Ossama Alshareif ◽  
Marina Adel Shehata ◽  
Patrícia Paula de Carvalho Sampaio Lima ◽  
...  
Keyword(s):  
Pairwise Comparison ◽  
Oral Appliance ◽  
Comparable Efficacy ◽  
Double Blind ◽  
Fluoride Toothpaste ◽  
Initial Caries ◽  
Significant Difference ◽  
Post Test ◽  
Amine Fluoride

Abstract Objective This in situ study compared the effectiveness of two toothpastes containing hydroxyapatite or 500 ppm fluoride in promoting remineralization and inhibiting caries development. Materials and methods Two enamel blocks (human primary teeth), one sound and one with artificially-produced caries lesion, were exposed to toothpaste containing either 10% hydroxyapatite or 500 ppm F− (amine fluoride) via intra-oral appliance worn by 30 adults in two-arm double blind randomized crossover study lasting 14 days per arm (ClinicalTrials.gov: NCT03681340). Baseline and post-test mineral loss and lesion depth (LD) were quantified using microradiography. One-sided t-test of one group mean was used for intragroup comparison (baseline vs. post-test), while two-sided t-test of two independent means was used to compare the two toothpaste groups. Results Pairwise comparison (baseline vs. test) indicated significant (p < 0.0001) remineralization and LD reduction by either toothpaste; however, when compared against each other, there was no statistically significant difference in remineralization or LD reduction between the two toothpastes. No demineralization could be observed in sound enamel blocks exposed to either toothpaste. While F− induced lesion surface lamination, HAP produced a more homogenous lesion remineralization. Conclusions 10% hydroxyapatite achieved comparable efficacy with 500 ppm F− in remineralizing initial caries and preventing demineralization. Thus the HAP toothpaste is confirmed to be equal to the fluoride toothpaste in this study.

scholarly journals Discrete-Fracture Modeling of Thermal-Hydrological Processes at Yucca Mountain and the Llnl G-Tunnel Heater Test

1995 ◽  
Vol 412 ◽  
Author(s):  
John J. Nitao ◽  
Thomas A. Buscheck
Keyword(s):  
Test Site ◽  
Yucca Mountain ◽  
Fracture Flow ◽  
Transport Code ◽  
Fracture Modeling ◽  
Discrete Fracture ◽  
The Matrix ◽  
Fracture Models ◽  
Equivalent Continuum

AbstractAn in situ heater test was performed at G-Tunnel, Nevada Nuclear Test Site, to investigate the thermal-hydrological response of unsaturated, fractured volcanic tuff under conditions similar to those at Yucca Mountain. The NUFT flow and transport code was used to model the test using discrete-fracture and equivalent-continuum approaches. Nonequilibrium fracture flow and thermal buoyant gas-phase convection were found to be the likely causes for observed lack of condensate imbibition into the matrix. The potential repository at Yucca Mountain was also modeled. Disequilibrium fracture flow is predicted to occur for less than a hundred years after emplacement followed by a period of fracture-matrix equilibrium, during which the equivalent-continuum and discrete-fracture models give almost identical results.

High-pressure catalytic combustion of methane over platinum: In situ experiments and detailed numerical predictions

2004 ◽  
Vol 136 (1-2) ◽  
pp. 217-240 ◽  
Author(s):  
Michael Reinke ◽  
John Mantzaras ◽  
Rolf Schaeren ◽  
Rolf Bombach ◽  
Andreas Inauen ◽  
...  
Keyword(s):  
High Pressure ◽  
Catalytic Combustion ◽  
Numerical Predictions ◽  
In Situ Experiments ◽  
Catalytic Combustion Of Methane
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