Searched for: subject%3A%22cone%22
(1 - 19 of 19)
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Simons, E.C. (author), Weerheijm, J. (author), Toussaint, G. (author), Sluys, L.J. (author)
In this study, the impact of a steel spherical projectile on an alumina ceramic is considered. New experimental and numerical results are presented and analysed. Numerical results are obtained using the Finite Element Method and the upgraded viscosity regularized Johnson-Holmquist-2 constitutive model to describe the ceramic material behaviour....
article 2020
document
Koster, K. (author), Erkens, G. (author), Zwanenburg, C. (author)
Land subsidence threatens many coastal areas. Quantifying current and predicting future subsidence are essential to sustain the viability of these areas with respect to rising sea levels. Despite its scale and severity, methods to quantify subsidence are scarce. In peat-rich subsidence hot spots, subsidence is often caused by peat compression....
article 2016
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TNO Defensie en Veiligheid (author), Veraar, R.G. (author), Mayer, A.E.H.J. (author), Verreault, J. (author), Stowe, R.A. (author), Farinaccio, R. (author), Harris, P.G. (author)
By injecting and mixing the fuel upstream of the combustor and initiating the combustion of the fuel-air mixture by a shock wave in the combustor, shock-induced combustion ramjets offer the potential to drastically reduce the length and mass of scramjet propulsion systems. Based on extensive numerical gas dynamic and thermo-mechanical analysis,...
conference paper 2010
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Veraar, R.G. (author), Mayer, A.E.H.J. (author), Verreault, J. (author), Stowe, R.A. (author), Farinaccio, R. (author), Harris, P.G. (author), TNO Defensie en Veiligheid (author)
By injecting and mixing the fuel upstream of the combustor and initiating the combustion of the fuel-air mixture by a shock wave in the combustor, shock-induced combustion ramjets offer the potential to drastically reduce the length and mass of scramjet propulsion systems. Based on extensive numerical gas dynamic and thermo-mechanical analysis,...
conference paper 2009
document
Leemhuis, A.P. (author), Nennie, E.D. (author), Belfroid, S.P.C. (author), Alberts, G.J.N. (author), Peters, E. (author), Joosten, G.J.P. (author), TNO Industrie en Techniek (author)
A strong increase in gas inflow due to gas coning and the resulting bean-back because of Gas to Oil Ratio (GOR) constraints can severely limit oil production and reservoir drive energy. In this paper we will use a coupled reservoir-well model to demonstrate that oil production can be increased by using controlled inflow from a gas cone as a...
conference paper 2008
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de Kruif, B.J. (author), Leskens, M. (author), van der Linden, R. (author), Alberts, G.J.N. (author), TNO Industrie en Techniek (author)
Real-time monitoring of downhole oil, gas and water flows in wells can significantly improve the production performance of these wells when this flow rate information is used to manipulate inflow control valves. An example of this is the allocation of a gas or water cone to its entrance point in a multilateral well, allowing to close down the...
conference paper 2008
document
TNO Bouw en Ondergrond (author), Donselaar, M.E. (author), Geel, C.R. (author)
The size, shape and spatial position of lithofacies types (or facies architecture) in a tidal estuarine basin are complex and therefore difficult to model. The tidal currents in the basin concentrate sand-sized sediment in a branching pattern of tidal channels and fringing tidal flats. Away from the sandy tidal flats the sediment gradually...
article 2007
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Lucassen, M.P. (author), Alferdinck, J.W.A.M. (author), TNO Defensie en Veiligheid (author)
We report on a dynamic simulation of defective color vision. Using an RGB video camera connected to a PC or laptop, the captured and displayed RGB colors are translated by our software into modified RGB values that simulate the color appearance of a person with a color deficiency. Usually, the simulation of deficient color vision is restricted...
conference paper 2006
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Alferdinck, J.W.A.M. (author), TNO Defensie en Veiligheid (author)
During night-time driving hazardous objects often appear at mesopic light levels, which are typically measured using light meters with a spectral sensitivity that is only valid for photopic light levels. In order to develop suitable mesopic models a target detection experiment was performed in a driving simulator. While subjects drove along a...
article 2006
document
Zagers, N.P.A. (author), Pot, M.C.A. (author), van Norren, D. (author)
Our aim was to assess the integrity of the photoreceptors in the fovea, and to measure the optical density of the macular pigment and the eye lens in patients with diabetes mellitus, and to compare the results with those of a group of healthy subjects. The directional and spectral properties of the light reflected from a 1.9 deg field centered...
article 2005
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Lucassen, M.P. (author), Walraven, J. (author), TNO Defensie en Veiligheid (author)
In a preceding study we measured human color constancy in experimental conditions in which simulated illuminants and surface colors were varied in the chromatic domain only. Both illumination level and sample re.ectance were fixed in that study. In the present study we focus on the achromatic dimension, both with respect to luminance contrast ...
article 2005
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Sturm, W.L. (author), Belfroid, S.P.C. (author), van Wolfswinkel, O. (author), Peters, M.C.A.M. (author), Verhelst, F.J.P.C.M. (author), Technisch Physische Dienst TNO - TH (author)
In order to develop smart well control systems for unstable oil wells, realistic modeling of the dynamics of the well is essential. Most dynamic well models use a semi-steady state inflow model to describe the inflow of oil and gas from the reservoir. On the other hand, reservoir models use steady state lift curves for modeling of the wells....
conference paper 2004
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Zagers, N.P.A. (author), van Norren, D. (author)
We measured the amplitude of the directional component of the bleached fundus reflectance, the so-called optical Stiles-Crawford effect, as a function of wavelength. The directional reflectance originates from within the outer segments of the photoreceptors. Thus only two anterior absorbers are of importance: Macular pigment and the crystalline...
article 2004
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Berendschot, T.T.J.M. (author), Delint, P.J. (author), van Norren, D. (author), TNO Technische Menskunde (author)
In 1851 Helmholtz introduced the ophthalmoscope. The instrument allowed the observation of light reflected at the fundus. The development of this device was one of the major advancements in ophthalmology. Yet ophthalmoscopy allows only qualitative observation of the eye. Since 1950 attempts were made to address the challenging, quantitative...
article 2003
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Zagers, N.P.A. (author), Berendschot, T.T.J.M. (author), van Norren, D. (author)
We present evidence for the wavelength dependence of the directionality of light reflected from cone receptor cells (optical StilesCrawford effect): Blue light is more directional than red. According to the waveguide-scattering model of Marcos J. Opt. Soc. Am. A 15 , 2012 (1998), directionality is the sum of a waveguide component and a...
article 2003
document
Bouman, M.A. (author)
Thresholds for seeing light from a stimulus are determined by a mechanism that pairs subliminal excitations from both halves of a twin unit. Such excitations stem from a package of k ≥ 1 receptor responses. A half-unit contains one red or one green cone and P rods. The receptor's "Weber machine" controls the receptor's gain. Each half of a twin...
article 2002
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Zagers, N.P.A. (author), van de Kraats, J. (author), Berendschot, T.T.J.M. (author), van Norren, D. (author)
An instrument for simultaneous measurement of foveal spectral reflectance and cone-photoreceptor directionality is described. The key element is an imaging spectrograph (spectral range of 420–790 nm) with its entrance slit conjugate to the pupil plane of a human eye. A 1.9-deg spot on the retina is sampled in 1 s. Video observation of the retina...
article 2002
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Walraven, J. (author), Werner, J.S. (author)
The locus of unique white was measured for two observers over a wide range of stimulus intensities, using both direct matching and absolute judgements. Chromaticity coordinates of each observer's unique white were found to be invariant over a range of about 4 log units. This result is discussed in the context of the class of models that explain...
article 1991
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Vos, J.J. (author), Estevez, O. (author), Walraven, P.L. (author), Instituut voor Zintuigfysiologie TNO (author)
New action spectra are derived for the foveal cones on the basis of three assumptions: (1) the Stiles-Burch (1959) colorimetric data are better than CIE 1931; (2) the long wavelength flanks of the dichromatic luminosity functions offer better anchorage than the confusion loci; and (3) the relative mutual heights per receptor can be derived from...
article 1990
Searched for: subject%3A%22cone%22
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