A variable profile depth crossed-grating-based exit pupil expander with improved imaging brightness uniformity

2021 ◽  
Author(s):  
Qimeng Wang ◽  
Yuxuan Zhao ◽  
Lijiang Zeng
Keyword(s):  
Exit Pupil ◽  
Profile Depth

scholarly journals Tire/Road Rolling Resistance Modeling: Discussing the Surface Macrotexture Effect

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 538
Author(s):  
Malal Kane ◽  
Ebrahim Riahi ◽  
Minh-Tan Do
Keyword(s):  
Slip Rate ◽  
Rolling Resistance ◽  
Friction Model ◽  
Slip Rates ◽  
Wide Range ◽  
Road Surfaces ◽  
Profile Depth ◽  
Experimental Rolling ◽  
Resistance Modeling ◽  
Pavement Friction

This paper deals with the modeling of rolling resistance and the analysis of the effect of pavement texture. The Rolling Resistance Model (RRM) is a simplification of the no-slip rate of the Dynamic Friction Model (DFM) based on modeling tire/road contact and is intended to predict the tire/pavement friction at all slip rates. The experimental validation of this approach was performed using a machine simulating tires rolling on road surfaces. The tested pavement surfaces have a wide range of textures from smooth to macro-micro-rough, thus covering all the surfaces likely to be encountered on the roads. A comparison between the experimental rolling resistances and those predicted by the model shows a good correlation, with an R2 exceeding 0.8. A good correlation between the MPD (mean profile depth) of the surfaces and the rolling resistance is also shown. It is also noticed that a random distribution and pointed shape of the summits may also be an inconvenience concerning rolling resistance, thus leading to the conclusion that beyond the macrotexture, the positivity of the texture should also be taken into account. A possible simplification of the model by neglecting the damping part in the constitutive model of the rubber is also noted.

scholarly journals Reclaimed Asphalt Pavement (RAP) Based on a Geospatial Information System (GIS)

2020 ◽  
Vol 28 (2) ◽  
pp. 36-42
Author(s):  
Hossein Hariri Asli ◽  
Mahyar Arabani ◽  
Yaser Golpour
Keyword(s):  
Information System ◽  
Asphalt Pavement ◽  
Reclaimed Asphalt Pavement ◽  
Geospatial Information ◽  
Reclaimed Asphalt ◽  
Medium Risk ◽  
Profile Depth ◽  
Risk Zones ◽  
The Mean ◽  
Very High

AbstractA Geospatial Information System (GIS) is a system designed to capture, store, manipulate, analyze, manage, and present spatial or geospatial data. Reclaimed Asphalt Pavement (RAP) based on the GIS is one of the indirect and efficient methods in identifying areas. In this work, an analytical computational process combined with a spatial analysis was used to identify pavement zones for a city. The zoning results were categorized in four classes, including very high, high, medium risk, and low risk zones. The high and very high risk zones have been considered as a whole. The work circumstances include the Mean Profile Depth (MPD) data as a function of the number of wheel passes and the temperature; ten (10) specimens were selected from a set of 23 specimens. The results showed a good correlation between the parameters, including the number of wheels passing, the temperature, and the MPD.

Determination of Electrically Active Defect Profiles in Semiconductors Using a Photoelectrochemical Technique

1986 ◽  
Vol 82 ◽  
Author(s):  
F.D. Gealy ◽  
H.L. Tuller
Keyword(s):  
Impedance Spectroscopy ◽  
Liquid Electrolyte ◽  
Profile Measurement ◽  
Acceptor Concentration ◽  
Defect Profile ◽  
Profile Depth ◽  
Charge Capacitance ◽  
Substitutional Impurities ◽  
Good Agreement

ABSTRACTElectrically active defects are common in semiconductors. Such defects include easily ionized substitutional impurities, vacancies, and interstitials which can act as shallow donors or acceptors. If one type of defect predominates, its concentration corresponds directly to the local donor or acceptor concentration. Consequently, measurement of a carrier profile in a nonhomogeneous semiconductor is effectively the same as measurement of the defect profile.The photoelectrochemical profiling technique allows for carrier profile measurement with submicrometer spatial resolution. The sample is profiled by photoetching, then carrier measurement, and iterating this procedure until the desired profile depth is obtained.Derivation of the space charge capacitance by impedance spectroscopy is discussed. An analysis of the P-doped Si-liquid electrolyte interface is presented. Phosphorous diffusivity coefficients in good agreement with literature values are derived from photoelectrochemical derived profiles.

Mean residence times and characteristics of humic substances extracted from a Taiwan soil

2001 ◽  
Vol 81 (3) ◽  
pp. 299-307 ◽  
Author(s):  
M C Wang ◽  
S H Chang
Keyword(s):  
Humic Substances ◽  
Soil Profile ◽  
Fulvic Acids ◽  
Spectroscopic Properties ◽  
Residence Times ◽  
Spin Resonance ◽  
Profile Depth ◽  
Mean Residence Times ◽  
High Degree ◽  
C Nmr

Humic substances are well known for their long-term persistence in soil environments. The relationship between the mean residence times (MRT) and characteristics of humic substances extracted from a soil with highorganic matter (OM) content in Taiwan was investigated. The MRTs of the soil organic matter (SOM) and its humic substances extracted from the soil samples taken from three depths (0–20, 40–60, and 70–150 cm) of a soil profile were determined by 14C-dating procedures. Moreover, the humic substances were subjected to elemental analysis and investigation by electron spin resonance (ESR), Fourier transform infrared (FTIR), and solid-state 13C nuclear magnetic resonance (13C NMR) spectroscopies. The ranges of the MRT of fulvic acids (FA) (MW < 1000), FA (MW > 1000), humic acid (HA) (MW > 1000), and humins (MW > 1000) were 143 ± 110 to 1740 ± 60, 213 ± 120 to 1690 ± 200, 253 ± 60 to 2200 ± 40, and 293 ± 40 to 2173 ± 70 yr, respectively. The higher standard deviations of the means of determined MRTs of FA (MW < 1000) and FAs (MW > 1000) may be due to their lability. Further, the MRTs of the FAs (MW < 1000), FAs (MW > 1000), HAs (MW > 1000), and humins (MW > 1000) increased with increasing soil profile depth, indicating the slow biological and chemical degradations of humic substances in the deeper layers. The elemental composition and spectroscopic properties of FTIR, 13C NMR, and ESR of humic substances did not change significantly with their MRTs. The MRTs in the range observed in this study were apparently long enough to render humic substances a high degree of chemical stability. Key words: Humic substances, mean residence times, ESR, FTIR, 13C NMR, humin

Profile Depth

2011 ◽  
pp. 591-591
Author(s):  
Jan W. Gooch
Keyword(s):  
Profile Depth

scholarly journals Dependence of Heavy Soil Transport Function on Soil Profile Depth

2011 ◽  
Vol 57 (2) ◽  
pp. 45-52
Author(s):  
Dana Kotorová ◽  
Jana Jakubová ◽  
Ladislav Kováč
Keyword(s):  
Bulk Density ◽  
Soil Profile ◽  
Clayey Soil ◽  
Total Porosity ◽  
Soil Tillage ◽  
Transport Function ◽  
Clay Particles ◽  
Soil Transport ◽  
Heavy Soil ◽  
Profile Depth

Dependence of Heavy Soil Transport Function on Soil Profile DepthThe aim of this work was to quantify the effect of soil profile depth on the transport function of heavy soils. Treatments were carried out between 2006 and 2009 in Milhostov. Two variants were examined : the (conventional soil tillage and long-time no-tilled variant). Soil samples were taken in spring and autumn from soil profile depth of 0.00-0.60 m from each 0.10 m. For further evaluation the average values were used. Particle size composition, bulk density, total porosity and maximum capillary capacity were determined. Content of clay particles in soil profile was in interval 59.64-68.53% and such soils are characterised in the range from clay-loamy soil to clayey soil. The bulk density increased with the depth of soil profile and its values reached 1 184-1 646 kg m-3. The total porosity was in range 37.68-55.17% and it decreased with the depth of soil profile. The values of maximum capillary capacity were characterised for heavy soils with high content of clay particles. The depth had statistically significant effect on all observed parameters. In average, on both variants the bulk density was higher than 1 400 kg m-3, the total porosity was lower than 47% and the content of clay was higher than 30%, pointing to the possibility of soil compaction, which will result in reduced transport function of heavy soils.

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