Inhibitors of acid secretion can benefit gastric wound repair independent of luminal pH effects on the site of damage

PubMed Central

Demitrack, Elise S; Aihara, Eitaro; Kenny, Susan; Varro, Andrea; Montrose, Marshall H

2012-01-01

Background and aims The authors’ goal was to measure pH at the gastric surface (pHo) to understand how acid secretion affects the repair of microscopic injury to the gastric epithelium. Methods Microscopic gastric damage was induced by laser light, during confocal/two-photon imaging of pH-sensitive dyes (Cl-NERF, BCECF) that were superfused over the mucosal surface of the exposed gastric corpus of anaesthetised mice. The progression of repair was measured in parallel with pHo. Experimental conditions included varying pH of luminal superfusates, and using omeprazole (60 mg/kg ip) or famotidine (30 mg/kg ip) to inhibit acid secretion. Results Similar rates of epithelial repair and resting pHo values (~pH 4) were reported in the presence of luminal pH 3 or pH 5. Epithelial repair was unreliable at luminal pH 2 and pHo was lower (2.5±0.2, P <0.05 vs pH 3). Epithelial repair was slower at luminal pH 7 and pHo was higher (6.4±0.1, P<0.001). In all conditions, pHo increased adjacent to damage. At luminal pH 3 or pH 7, omeprazole reduced maximal damage size and accelerated epithelial repair, although only at pH 3 did omeprazole further increase surface pH above the level caused by imposed damage. At luminal pH 7, famotidine also reduced maximal damage size and accelerated epithelial repair. Neither famotidine nor omeprazole raised plasma gastrin levels during the time course of the experiments. Conclusions Epithelial repair in vivo is affected by luminal pH variation, but the beneficial effects of acutely blocking acid secretion extend beyond simply raising luminal and/or surface pH. PMID:21997560

Modulation of Cardiac Ryanodine Receptor Channels by Alkaline Earth Cations

PubMed Central

Diaz-Sylvester, Paula L.; Porta, Maura; Copello, Julio A.

2011-01-01

Cardiac ryanodine receptor (RyR2) function is modulated by Ca2+ and Mg2+. To better characterize Ca2+ and Mg2+ binding sites involved in RyR2 regulation, the effects of cytosolic and luminal earth alkaline divalent cations (M2+: Mg2+, Ca2+, Sr2+, Ba2+) were studied on RyR2 from pig ventricle reconstituted in bilayers. RyR2 were activated by M2+ binding to high affinity activating sites at the cytosolic channel surface, specific for Ca2+ or Sr2+. This activation was interfered by Mg2+ and Ba2+ acting at low affinity M2+-unspecific binding sites. When testing the effects of luminal M2+ as current carriers, all M2+ increased maximal RyR2 open probability (compared to Cs+), suggesting the existence of low affinity activating M2+-unspecific sites at the luminal surface. Responses to M2+ vary from channel to channel (heterogeneity). However, with luminal Ba2+or Mg2+, RyR2 were less sensitive to cytosolic Ca2+ and caffeine-mediated activation, openings were shorter and voltage-dependence was more marked (compared to RyR2 with luminal Ca2+or Sr2+). Kinetics of RyR2 with mixtures of luminal Ba2+/Ca2+ and additive action of luminal plus cytosolic Ba2+ or Mg2+ suggest luminal M2+ differentially act on luminal sites rather than accessing cytosolic sites through the pore. This suggests the presence of additional luminal activating Ca2+/Sr2+-specific sites, which stabilize high Po mode (less voltage-dependent) and increase RyR2 sensitivity to cytosolic Ca2+ activation. In summary, RyR2 luminal and cytosolic surfaces have at least two sets of M2+ binding sites (specific for Ca2+ and unspecific for Ca2+/Mg2+) that dynamically modulate channel activity and gating status, depending on SR voltage. PMID:22039534

Integration of organic LEDs with inorganic LEDs for a hybrid lighting system

NASA Astrophysics Data System (ADS)

Kong, H. J.; Park, J. W.; Kim, Y. M.

2013-01-01

We demonstrate that a surface-emitting hybrid light source can be realized by a combination of organic and inorganic light-emitting devices (LEDs). To this end, a blue inorganic LED bar is deployed at one side of a transparent light guide plate (LGP), and a yellow organic LED (OLED) is in contact with the rear surface of the LGP. In such a configuration, it is found that the overall luminance is almost equivalent to the sum of the luminances measured from each light source, and the overall luminance uniformity is determined mainly by the luminance uniformity of the OLED panel at high luminances. We have achieved a white color showing the Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (x = 0.34, y = 0.33), the power efficiency of 9.3 lm/W, the luminance uniformity of 63% at the luminance of 3100 cd m-2, the color rendering index as high as 89.3, and the correlated color temperature finely tunable within the range between 3000 and 8000 K. Such a system facilitates color tuning by adjusting their luminous intensities and hence the implementation of the emotional lighting system.

Luminous flux and illumination

NASA Astrophysics Data System (ADS)

Schröer, H.

2001-06-01

Themes of this book are luminous flux and illumination. The book begins with definitions of the notions luminous flux and solid angle. Then the luminous flux through simple geometrical areas as circle, ball, triangles and n-gons is treated. Chapter 7 deals with luminous flux through general surfaces. A comparison between photometric and radiation dimensions follow. The next chapter contains the luminous flux through simple areas in medium (gas). At last illumination and temperature are presented. The content is interesting for opticians, light technicians and all physicists and natural scientists, who have to do with radiation. There is an english and a german edition.

Ambient illumination revisited: A new adaptation-based approach for optimizing medical imaging reading environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chawla, Amarpreet S.; Samei, Ehsan; Duke Advanced Imaging Laboratories, Departments of Radiology, Physics, Medical Physics, and Biomedical Engineering, Duke University, Durham, North Carolina 27705

2007-01-15

Ambient lighting in soft-copy reading rooms is currently kept at low values to preserve contrast rendition in the dark regions of a medical image. Low illuminance levels, however, create inadequate viewing conditions and may also cause eye strain. This eye strain may be potentially attributed to notable variations in the luminance adaptation state of the reader's eyes when moving the gaze intermittently between the brighter display and darker surrounding surfaces. This paper presents a methodology to minimize this variation and optimize the lighting conditions of reading rooms by exploiting the properties of liquid crystal displays (LCDs) with low diffuse reflectionmore » coefficients and high luminance ratio. First, a computational model was developed to determine a global luminance adaptation value, L{sub adp}, when viewing a medical image on display. The model is based on the diameter of the pupil size, which depends on the luminance of the observed object. Second, this value was compared with the luminance reflected off surrounding surfaces, L{sub s}, under various conditions of room illuminance, E, different values of diffuse reflection coefficients of surrounding surfaces, R{sub s}, and calibration settings of a typical LCD. The results suggest that for typical luminance settings of current LCDs, it is possible to raise ambient illumination to minimize differences in eye adaptation, potentially reducing visual fatigue while also complying with the TG18 specifications for controlled contrast rendition. Specifically, room illumination in the 75-150 lux range and surface diffuse reflection coefficients in the practical range of 0.13-0.22 sr{sup -1} provide an ideal setup for typical LCDs. Future LCDs with lower diffuse reflectivity and with higher inherent luminance ratios can provide further improvement of ergonomic viewing conditions in reading rooms.« less

Lines that induce phenomenal transparency.

PubMed

Grieco, Alba; Roncato, Sergio

2005-01-01

Three neighbouring opaque surfaces may appear split into two layers, one transparent and one opaque beneath, if an outline contour is drawn that encompasses two of them. The phenomenon was originally observed by Kanizsa [1955 Rivista di Psicologia 69 3-19; 1979 Organization in Vision: Essays on Gestalt Psychology (New York: Praeger)], for the case where an outline contour is drawn to encompass one of the two parts of a bicoloured figure and a portion of a background of lightest (or darkest) luminance. Preliminary observations revealed that the outline contour yields different effects: in addition to the stratification into layers described by Kanizsa, a second split, opposite in depth order, may occur when the outline contour is close in luminance to one of the three surfaces. An initial experiment was designed to investigate what conditions give rise to the two phenomenal transparencies: this led to the conclusion that an outline contour superimposed on an opaque surface causes this surface to emerge as a transparent layer when the luminances of the contour and the surface differ, in absolute value, by no more than 13.2 cd m(-2). We have named this phenomenon 'transparency of the intercepted surface', to distinguish it from the phenomenal transparency arising when the contour and surface are very different in luminance. When such a difference exists, the contour acts as a factor of surface definition and grouping: the portion of the homogeneous surface it bounds emerges as a fourth surface and groups with a nearby surface if there is one close in luminance. The transparency phenomena ('transparency of the contoured surface') perceived in this context conform to the constraints of Metelli's model, as demonstrated by a second experiment, designed to gather 'opacity' ratings of stimuli. The observer judgments conformed to the values predicted by Metelli's formula for perceived degree of transparency, alpha. The role of the outline contour in conveying figural and intensity information is discussed.

Maintenance and regulation of the pH microclimate at the luminal surface of the distal colon of guinea-pig

PubMed Central

Genz, Anne-Katrin; v Engelhardt, Wolfgang; Busche, Roger

1999-01-01

The fluorescent dye 5-N-hexadecanoyl-aminofluorescein (HAF) was used to study the mechanisms involved in maintaining a relatively constant luminal surface pH (pHs) in the distal colon of the guinea-pig. The fatty acyl chain of the HAF molecule inserts into the apical membrane of epithelial cells. This allows a continuous measurement of the surface pH for several hours. The localization of HAF was confirmed by confocal laser-scanning microscopy and by using monoclonal antibodies against fluorescein. The insertion of HAF into the apical membrane of the colonocytes did not change the transepithelial conductance or the short-circuit current of the epithelium. With the HAF method a pH microclimate was confirmed at the colonic surface. Although the pH of the bulk luminal solution was decreased in bicarbonate-containing solution from 7.4 to 6.4 the pHs changed only in the range 7.54-6.98. In the absence of bicarbonate pHs almost followed changes of bulk luminal pH. In the presence of bicarbonate there was a decrease in pHs after removal of chloride from the luminal side and an increase in pHs after addition of butyrate to the luminal solution. This suggests the involvement of a bicarbonate-anion exchange in bicarbonate secretion: a Cl−-HCO3− as well as a short-chain fatty acid−-HCO3− exchange. The apical K+-H+-ATPase in the distal colon of guinea-pig has little influence on pHs in the presence of physiological buffer concentrations. Our findings indicate that bicarbonate plays a major role in maintaining the pH microclimate at the colonic surface. PMID:10332098

Three-dimensional spatial grouping affects estimates of the illuminant

NASA Astrophysics Data System (ADS)

Perkins, Kenneth R.; Schirillo, James A.

2003-12-01

The brightnesses (i.e., perceived luminance) of surfaces within a three-dimensional scene are contingent on both the luminances and the spatial arrangement of the surfaces. Observers viewed a CRT through a haploscope that presented simulated achromatic surfaces in three dimensions. They set a test patch to be ~33% more intense than a comparison patch to match the comparison patch in brightness, which is consistent with viewing a real scene with a simple lightning interpretation from which to estimate a different level of illumination in each depth plane. Randomly positioning each surface in either depth plane minimized any simple lighting interpretation, concomitantly reducing brightness differences to ~8.5%, although the immediate surrounds of the test and comparison patches continued to differ by a 5:1 luminance ratio.

Vocal Fold Epithelial Response to Luminal Osmotic Perturbation

ERIC Educational Resources Information Center

Sivasankar, Mahalakshmi; Fisher, Kimberly V.

2007-01-01

Purpose: Dry-air challenges increase the osmolarity of fluid lining the luminal surface of the proximal airway. The homeostasis of surface fluid is thought to be essential for voice production and laryngeal defense. Therefore, the authors hypothesized that viable vocal fold epithelium would generate a water flux to reduce an osmotic challenge (150…

Informational primacy of visual dimensions: specialized roles for luminance and chromaticity in figure-ground perception.

PubMed

Yamagishi, N; Melara, R D

2001-07-01

Three experiments were conducted to examine the distinct contributions of two visual dimensions to figure-ground segregation. In each experiment, pattern identification was assessed by asking observers to judge whether a near-threshold test pattern was the same or different in shape to a high-contrast comparison pattern. A test pattern could differ from its background along one dimension, either luminance (luminance tasks) or chromaticity (chromaticity tasks). In each task, performance in a baseline condition, in which the test pattern was intact, was compared with performance in each of several degradation conditions, in which either the contour or the surface of the figure was degraded, using either partial occlusion (Experiment 1) or ramping (Experiments 2 and 3) of figure-ground differences. In each experiment, performance in luminance tasks was worst when the contour was degraded, whereas performance in chromaticity tasks was worst when the surface was degraded. This interaction was found even when spatial frequencies were fixed across test patterns by low-pass filtering. The results are consistent with a late (postfiltering) dual-mechanism system that processes luminance information to extract boundary representations and chromaticity information to extract surface representations.

Luminance cues constrain chromatic blur discrimination in natural scene stimuli.

PubMed

Sharman, Rebecca J; McGraw, Paul V; Peirce, Jonathan W

2013-03-22

Introducing blur into the color components of a natural scene has very little effect on its percept, whereas blur introduced into the luminance component is very noticeable. Here we quantify the dominance of luminance information in blur detection and examine a number of potential causes. We show that the interaction between chromatic and luminance information is not explained by reduced acuity or spatial resolution limitations for chromatic cues, the effective contrast of the luminance cue, or chromatic and achromatic statistical regularities in the images. Regardless of the quality of chromatic information, the visual system gives primacy to luminance signals when determining edge location. In natural viewing, luminance information appears to be specialized for detecting object boundaries while chromatic information may be used to determine surface properties.

The perception of object versus objectless motion.

PubMed

Hock, Howard S; Nichols, David F

2013-05-01

Wertheimer, M. (Zeitschrift für Psychologie und Physiologie der Sinnesorgane, 61:161-265, 1912) classical distinction between beta (object) and phi (objectless) motion is elaborated here in a series of experiments concerning competition between two qualitatively different motion percepts, induced by sequential changes in luminance for two-dimensional geometric objects composed of rectangular surfaces. One of these percepts is of spreading-luminance motion that continuously sweeps across the entire object; it exhibits shape invariance and is perceived most strongly for fast speeds. Significantly for the characterization of phi as objectless motion, the spreading luminance does not involve surface boundaries or any other feature; the percept is driven solely by spatiotemporal changes in luminance. Alternatively, and for relatively slow speeds, a discrete series of edge motions can be perceived in the direction opposite to spreading-luminance motion. Akin to beta motion, the edges appear to move through intermediate positions within the object's changing surfaces. Significantly for the characterization of beta as object motion, edge motion exhibits shape dependence and is based on the detection of oppositely signed changes in contrast (i.e., counterchange) for features essential to the determination of an object's shape, the boundaries separating its surfaces. These results are consistent with area MT neurons that differ with respect to speed preference Newsome et al (Journal of Neurophysiology, 55:1340-1351, 1986) and shape dependence Zeki (Journal of Physiology, 236:549-573, 1974).

A common framework for the analysis of complex motion? Standstill and capture illusions

PubMed Central

Dürsteler, Max R.

2014-01-01

A series of illusions was created by presenting stimuli, which consisted of two overlapping surfaces each defined by textures of independent visual features (i.e., modulation of luminance, color, depth, etc.). When presented concurrently with a stationary 2-D luminance texture, observers often fail to perceive the motion of an overlapping stereoscopically defined depth-texture. This illusory motion standstill arises due to a failure to represent two independent surfaces (one for luminance and one for depth textures) and motion transparency (the ability to perceive motion of both surfaces simultaneously). Instead the stimulus is represented as a single non-transparent surface taking on the stationary nature of the luminance-defined texture. By contrast, if it is the 2D-luminance defined texture that is in motion, observers often perceive the stationary depth texture as also moving. In this latter case, the failure to represent the motion transparency of the two textures gives rise to illusionary motion capture. Our past work demonstrated that the illusions of motion standstill and motion capture can occur for depth-textures that are rotating, or expanding / contracting, or else spiraling. Here I extend these findings to include stereo-shearing. More importantly, it is the motion (or lack thereof) of the luminance texture that determines how the motion of the depth will be perceived. This observation is strongly in favor of a single pathway for complex motion that operates on luminance-defines texture motion signals only. In addition, these complex motion illusions arise with chromatically-defined textures with smooth transitions between their colors. This suggests that in respect to color motion perception the complex motions' pathway is only able to accurately process signals from isoluminant colored textures with sharp transitions between colors, and/or moving at high speeds, which is conceivable if it relies on inputs from a hypothetical dual opponent color pathway. PMID:25566023

Luminance-based specular gloss characterization.

PubMed

Leloup, Frédéric B; Pointer, Michael R; Dutré, Philip; Hanselaer, Peter

2011-06-01

Gloss is a feature of visual appearance that arises from the directionally selective reflection of light incident on a surface. Especially when a distinct reflected image is perceptible, the luminance distribution of the illumination scene above the sample can strongly influence the gloss perception. For this reason, industrial glossmeters do not provide a satisfactory gloss estimation of high-gloss surfaces. In this study, the influence of the conditions of illumination on specular gloss perception was examined through a magnitude estimation experiment in which 10 observers took part. A light booth with two light sources was utilized: the mirror image of only one source being visible in reflection by the observer. The luminance of both the reflected image and the adjacent sample surface could be independently varied by separate adjustment of the intensity of the two light sources. A psychophysical scaling function was derived, relating the visual gloss estimations to the measured luminance of both the reflected image and the off-specular sample background. The generalization error of the model was estimated through a validation experiment performed by 10 other observers. In result, a metric including both surface and illumination properties is provided. Based on this metric, improved gloss evaluation methods and instruments could be developed.

Pupil size reflects the focus of feature-based attention.

PubMed

Binda, Paola; Pereverzeva, Maria; Murray, Scott O

2014-12-15

We measured pupil size in adult human subjects while they selectively attended to one of two surfaces, bright and dark, defined by coherently moving dots. The two surfaces were presented at the same location; therefore, subjects could select the cued surface only on the basis of its features. With no luminance change in the stimulus, we find that pupil size was smaller when the bright surface was attended and larger when the dark surface was attended: an effect of feature-based (or surface-based) attention. With the same surfaces at nonoverlapping locations, we find a similar effect of spatial attention. The pupil size modulation cannot be accounted for by differences in eye position and by other variables known to affect pupil size such as task difficulty, accommodation, or the mere anticipation (imagery) of bright/dark stimuli. We conclude that pupil size reflects not just luminance or cognitive state, but the interaction between the two: it reflects which luminance level in the visual scene is relevant for the task at hand. Copyright © 2014 the American Physiological Society.

Alkaline phosphatase, 5'-nucleotidase and magnesium-dependent adenosine triphosphatase activities in the transitional epithelium of the rat urinary bladder.

PubMed

Zhang, S X; Kobayashi, T; Okada, T; García del Saz, E; Seguchi, H

1991-07-01

The cerium-based method was used to demonstrate cytochemically the ultrastructural localization of alkaline phosphatase (ALPase), 5'-nucleotidase (5'-Nase) and magnesium-dependent adenosine triphosphatase (Mg-ATPase) on the transitional epithelium of the rat urinary bladder. The reaction product for ALPase was found on the plasma membrane of all epithelial cells, except the luminal surface of superficial cells. The activity of 5'-Nase appeared on the plasma membrane of all bladder transitional epithelial cells, including the free surface of superficial cells. The Mg-ATPase reaction product was seen on the plasma membrane of superficial, intermediate and basal cells, but never on the luminal surface of superficial cells and it was only occasionally seen on the basal surface. The possible functions of these phosphatases have been discussed, and it was emphasized that the 5'-Nase activity present on the luminal surface of superficial cells may play a special role in the membrane movement of these cells in the transitional epithelium.

Detection of Lysosomal Exocytosis by Surface Exposure of Lamp1 Luminal Epitopes.

PubMed

Andrews, Norma W

2017-01-01

Elevation in the cytosolic Ca 2+ concentration triggers exocytosis of lysosomes in many cell types. This chapter describes a method to detect lysosomal exocytosis in mammalian cells, which takes advantage of the presence of an abundant glycoprotein, Lamp1, on the membrane of lysosomes. Lamp1 is a transmembrane protein with a large, heavily glycosylated region that faces the lumen of lysosomes. When lysosomes fuse with the plasma membrane, epitopes present on the luminal domain of Lamp1 are exposed on the cell surface. The Lamp1 luminal epitopes can then be detected on the surface of live, unfixed cells using highly specific monoclonal antibodies and fluorescence microscopy. The main advantage of this method is its sensitivity, and the fact that it provides spatial information on lysosomal exocytosis at the single cell level.

Presence of MUC4 in human milk and at the luminal surfaces of blood vessels.

PubMed

Zhang, Jin; Perez, Aymee; Yasin, Mohammad; Soto, Pedro; Rong, Min; Theodoropoulos, George; Carothers Carraway, Coralie A; Carraway, Kermit L

2005-07-01

MUC4 is a heterodimeric membrane mucin, composed of a mucin subunit ASGP-1 (MUC4alpha) and a transmembrane subunit ASGP-2 (MUC4beta), which has been implicated in the protection of epithelial cell surfaces. Surprisingly, development and characterization of a new monoclonal antibody (mAb), called 1G8, against ASGP-2 demonstrated by immunohistochemistry the presence of MUC4 at the luminal surfaces of blood vessels of both normal tissues and tumors. Muc4 was detected with 1G8 and other Muc4 antibodies in blood vessels from humans, rats and mice. This expression of MUC4 in endothelial cells was confirmed by immunoblotting with 1G8 in human umbilical vein endothelial cells (HUVECs), human iliac artery endothelial cells (HIAECs), and human microvascular endothelial cells (HMVECs). MUC4 could be observed on HUVECs grown on either plastic or Matrigel. Finally, MUC4 expression in the three types of endothelial cell lines was confirmed by reverse transcription-polymerase chain reaction (RT-PCR). These results provide, to our knowledge, the first demonstration of a member of the MUC gene family and membrane mucin in blood vessels. As a luminal surface component, the MUC4 is situated to contribute to the non-adhesive luminal surface and to act as an intrinsic protection and survival factor. (c) 2004 Wiley-Liss, Inc.

Testing road surface treatments to reduce erosion in forest roads in Honduras [Tratamientos de la superficie de rodadura para reducir la erosion en caminos forestales en Honduras

USGS Publications Warehouse

Rivera, Samuel; Kershner, Jeffrey L.; Keller, Gordon R.

2009-01-01

Testing road surface treatments to reduce erosion in forest roads in Honduras. Cien. Inv. Agr. 36(3):425-432. Using forest roads produces more erosion and sedimentation than any other forest or agricultural activity. This study evaluated soil losses from a forest road in central Honduras over two consecutive years. We divided a 400-m segment of road into 8 experimental units, each 50 m in length. Four units were treated with Best Management Practices (BMPs) and four were left untreated. The BMP treatments included reshaping the road prism, installing culverts and reshaping of road ditches, compacting 20-cm layers of the road tread, crowning the road surface (3% slope, double drainage), longitudinal sloping (less than 12%), and adding a 10-cm layer of gravel (crush size = 0.63 cm). Soil movement was measured daily during the rainy seasons. The highest soil loss occurred in the control road, around 500 m3 km-1 per year, while the road treated with BMP lost approximately 225 m3km-1 per year. These results show that road surface erosion can be reduced up to 50% with the implementation of surface treatments.

Development of High-power LED Lighting Luminaires Using Loop Heat Pipe

NASA Astrophysics Data System (ADS)

Huang, Bin-Juine; Huang, Huan-Hsiang; Chen, Chun-Wei; Wu, Min-Sheng

High-power LED should reject about 6 times of heat of the conventional lighting device and keep the LED junction temperature below 80°C to assure reliability and low light decay. In addition, no fan is allowed and the heat dissipation design should not interfere with the industrial design of lighting fixture and have a light weight. This thus creates an extreme thermal management problem. The present study has shown that, using a special heat dissipation technology (loop heat pipe), the high-power LED lighting luminaire with input power from 36 to 150W for outdoor and indoor applications can be achieved with light weight, among 0.96 to 1.57 kg per 1,000 lumen of net luminous flux output from the luminaire. The loop heat pipe uses a flexible connecting pipe as the condenser which can be wounded around the reflector of the luminaire to dissipate the heat to the ambient air by natural convection. For roadway or street lighting application, the present study shows that a better optical design of LED lamps can further result in power consumption reduction, based on the same illumination on road surface. The high-power LED luminaries developed in the present study have shown that the energy saving is > 50% in road lighting applications as compared to sodium light or > 70% compared to mercury light.

Luminous Enteric Bacteria of Marine Fishes: a Study of Their Distribution, Densities, and Dispersion †

PubMed Central

Ruby, E. G.; Morin, J. G.

1979-01-01

Three taxa of luminous bacteria (Photobacterium fischeri, P. phosphoreum, and Beneckea spp.) were found in the enteric microbial populations of 22 species of surface- and midwater-dwelling fishes. These bacteria often occurred in concentrations ranging between 105 and 107 colony-forming units per ml of enteric contents. By using a genetically marked strain, it was determined that luminous cells entering the fish during ingestion of seawater or contaminated particles traversed the alimentary tract and survived the digestive processes. After excretion, luminous bacteria proliferated extensively on the fecal material and became distributed into the surrounding seawater. Thus, this enteric habitat may serve as an enrichment of viable cells entering the planktonic luminous population. PMID:16345429

30 CFR 761.14 - Procedures for relocating or closing a public road or waiving the prohibition on surface coal...

Code of Federal Regulations, 2010 CFR

2010-07-01

... road or waiving the prohibition on surface coal mining operations within the buffer zone of a public road. 761.14 Section 761.14 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT... Procedures for relocating or closing a public road or waiving the prohibition on surface coal mining...

Modeling on the cathodoluminescence properties of the thin film phosphors for field emission flat panel displays

NASA Astrophysics Data System (ADS)

Cho, Kyu-Gong

2000-12-01

In order to investigate the effects of the film roughness with the fundamental luminance parameters of thin film phosphors, Y2 O3:Eu films with different thickness and roughness values were deposited on various substrate materials using a pulsed laser deposition technique under a controlled experimental procedure. The best luminous efficiency was observed from the Y2O3:Eu films on quartz substrates due to the smaller refractive index and low absorption characteristics of the quartz substrates which produce a larger amount of total internal reflection in the film and low loss of light intensity during the multiple internal reflections. The trapped light inside the film can escape the film more easily due to rougher film surface. The better epitaxial growth capability of the Y2O 3:Eu films with the LaAlO3 substrates resulted in higher luminous efficiency in the small surface roughness region. Higher luminous efficiency was observed in reflection mode than in transmission mode due to the contribution of diffusely scattered light at the air-film interface. A new theoretical model based on the diffraction scattering theory of light, the steady-state diffusion condition of carriers and the Kanaya-Okayama's electron- beam-solid interaction range satisfactorily explains all the experimental results mentioned above. The model also provides solid understandings on the cathodoluminescence properties of the thin film phosphors with the effects of other single or multiple luminance parameters. The parameters encountered for the model are surface roughness, electron-beam-solid interaction, surface recombination rate of carriers, charge carrier diffusion properties, multiple scattering at the interfaces (air- film, film-substrate, and substrate-air), optical properties of the material, film thickness, and substrate type. The model supplies a general solution in both qualitative and quantitative ways to estimate the luminance properties of the thin film phosphors and it can be utilized to optimize the thin film phosphor properties for the application of field emission flat panel displays.

Distinguishing the road conditions of dry, aquaplane, and frozen by using a three-color infrared camera

NASA Astrophysics Data System (ADS)

Tabuchi, Toru; Yamagata, Shigeki; Tamura, Tetsuo

2003-04-01

There are increasing demands for information to avoid accident in automobile traffic increase. We will discuss that an infrared camera can identify three conditions (dry, aquaplane, frozen) of the road surface. Principles of this method are; 1.We have found 3-color infrared camera can distinguish those conditions using proper data processing 2.The emissivity of the materials on the road surface (conclete, water, ice) differs in three wavelength regions. 3.The sky's temperature is lower than the road's. The emissivity of the road depends on the road surface conditions. Therefore, 3-color infrared camera measure the energy reflected from the sky on the road surface and self radiation of road surface. The road condition can be distinguished by processing the energy pattern measured in three wavelength regions. We were able to collect the experimental results that the emissivity of conclete is differ from water. The infrared camera whose NETD (Noise Equivalent Temperature Difference) at each 3-wavelength is 1.0C or less can distinguish the road conditions by using emissivity difference.

An Automated Road Roughness Detection from Mobile Laser Scanning Data

NASA Astrophysics Data System (ADS)

Kumar, P.; Angelats, E.

2017-05-01

Rough roads influence the safety of the road users as accident rate increases with increasing unevenness of the road surface. Road roughness regions are required to be efficiently detected and located in order to ensure their maintenance. Mobile Laser Scanning (MLS) systems provide a rapid and cost-effective alternative by providing accurate and dense point cloud data along route corridor. In this paper, an automated algorithm is presented for detecting road roughness from MLS data. The presented algorithm is based on interpolating smooth intensity raster surface from LiDAR point cloud data using point thinning process. The interpolated surface is further processed using morphological and multi-level Otsu thresholding operations to identify candidate road roughness regions. The candidate regions are finally filtered based on spatial density and standard deviation of elevation criteria to detect the roughness along the road surface. The test results of road roughness detection algorithm on two road sections are presented. The developed approach can be used to provide comprehensive information to road authorities in order to schedule maintenance and ensure maximum safety conditions for road users.

Illuminance and luminance distributions of a prototype ambient illumination system for Space Station Freedom

NASA Technical Reports Server (NTRS)

Mullican, R. C.; Hayes, B. C.

1991-01-01

Preliminary results of research conducted in the late 1970's indicate that perceptual qualities of an enclosure can be influenced by the distribution of illumination within the enclosure. Subjective impressions such as spaciousness, perceptual clarity, and relaxation or tenseness, among others, appear to be related to different combinations of surface luminance. A prototype indirect ambient illumination system was developed which will allow crew members to alter surface luminance distributions within an enclosed module, thus modifying perceptual cues to match crew preferences. A traditional lensed direct lighting system was compared to the prototype utilizing the full-scale mockup of Space Station Freedom developed by Marshall Space Flight Center. The direct lensed system was installed in the habitation module with the indirect prototype deployed in the U.S. laboratory module. Analysis centered on the illuminance and luminance distributions resultant from these systems and the implications of various luminaire spacing options. All test configurations were evaluated for compliance with NASA Standard 3000, Man-System Integration Standards.

A numerical forecast model for road meteorology

NASA Astrophysics Data System (ADS)

Meng, Chunlei

2017-05-01

A fine-scale numerical model for road surface parameters prediction (BJ-ROME) is developed based on the Common Land Model. The model is validated using in situ observation data measured by the ROSA road weather stations of Vaisala Company, Finland. BJ-ROME not only takes into account road surface factors, such as imperviousness, relatively low albedo, high heat capacity, and high heat conductivity, but also considers the influence of urban anthropogenic heat, impervious surface evaporation, and urban land-use/land-cover changes. The forecast time span and the update interval of BJ-ROME in vocational operation are 24 and 3 h, respectively. The validation results indicate that BJ-ROME can successfully simulate the diurnal variation of road surface temperature both under clear-sky and rainfall conditions. BJ-ROME can simulate road water and snow depth well if the artificial removing was considered. Road surface energy balance in rainy days is quite different from that in clear-sky conditions. Road evaporation could not be neglected in road surface water cycle research. The results of sensitivity analysis show solar radiation correction coefficient, asphalt depth, and asphalt heat conductivity are important parameters in road interface temperatures simulation. The prediction results could be used as a reference of maintenance decision support system to mitigate the traffic jam and urban water logging especially in large cities.

Comparison of High and Low Density Airborne LIDAR Data for Forest Road Quality Assessment

NASA Astrophysics Data System (ADS)

Kiss, K.; Malinen, J.; Tokola, T.

2016-06-01

Good quality forest roads are important for forest management. Airborne laser scanning data can help create automatized road quality detection, thus avoiding field visits. Two different pulse density datasets have been used to assess road quality: high-density airborne laser scanning data from Kiihtelysvaara and low-density data from Tuusniemi, Finland. The field inventory mainly focused on the surface wear condition, structural condition, flatness, road side vegetation and drying of the road. Observations were divided into poor, satisfactory and good categories based on the current Finnish quality standards used for forest roads. Digital Elevation Models were derived from the laser point cloud, and indices were calculated to determine road quality. The calculated indices assessed the topographic differences on the road surface and road sides. The topographic position index works well in flat terrain only, while the standardized elevation index described the road surface better if the differences are bigger. Both indices require at least a 1 metre resolution. High-density data is necessary for analysis of the road surface, and the indices relate mostly to the surface wear and flatness. The classification was more precise (31-92%) than on low-density data (25-40%). However, ditch detection and classification can be carried out using the sparse dataset as well (with a success rate of 69%). The use of airborne laser scanning data can provide quality information on forest roads.

Slope-aspect color shading for parametric surfaces

NASA Technical Reports Server (NTRS)

Moellering, Harold J. (Inventor); Kimerling, A. Jon (Inventor)

1991-01-01

The invention is a method for generating an image of a parametric surface, such as the compass direction toward which each surface element of terrain faces, commonly called the slope-aspect azimuth of the surface element. The method maximizes color contrast to permit easy discrimination of the magnitude, ranges, intervals or classes of a surface parameter while making it easy for the user to visualize the form of the surface, such as a landscape. The four pole colors of the opponent process color theory are utilized to represent intervals or classes at 90 degree angles. The color perceived as having maximum measured luminance is selected to portray the color having an azimuth of an assumed light source and the color showing minimum measured luminance portrays the diametrically opposite azimuth. The 90 degree intermediate azimuths are portrayed by unique colors of intermediate measured luminance, such as red and green. Colors between these four pole colors are used which are perceived as mixtures or combinations of their bounding colors and are arranged progressively between their bounding colors to have perceived proportional mixtures of the bounding colors which are proportional to the interval's angular distance from its bounding colors.

Factors affecting the potassium concentration at the mucosal surface of the proximal and the distal colon of guinea pig.

PubMed Central

Kück-Biere, U; von Engelhardt, W

1990-01-01

K+ concentrations were measured in vitro with K+ sensitive microelectrodes in the microclimate at the luminal cell surface of the colon of guinea pigs. The serosal K+ concentration was mostly 5.4 mmol/1, the mucosal K+ concentrations were changed (0, 5, 50, or 70 mmol/l). Under control conditions K+ concentrations in the microclimate of the proximal colon were also low (6-9 mmol/l) and rather independent from K+ concentrations in the bulk luminal solution. In the distal colon K+ concentrations in the microclimate increased from 3.7 mmol/l when no K+ was in the luminal solution, up to 22 mmol/l when the mucosal K+ concentrations was 70 mmol/l. Attempts to decrease K+ conductance of the apical membrane with Ba++, to impair K+ transport with ouabain and to increase the paracellular shunt with deoxycholic acid did not affect K+ concentrations in the microclimate of the proximal colon but decreased K+ concentrations in the distal colon. When valinomycin or triaminopyrimidine were added to the mucosal solution at high K+ concentrations in the luminal solutions the K+ concentration in the microclimate was raised. At low luminal K+ concentrations valinomycin had no effect, triaminopyrimidine significantly diminished K+ concentrations at the cell surface. Regional differences in paracellular shunt conductance and in the preepithelial diffusion barrier are thought to be responsible for the observed differences between the proximal and the distal colon. Obviously, however, further unknown mechanisms have to be involved. PMID:2108077

Maintaining granular surfaced roads.

DOT National Transportation Integrated Search

1981-02-01

Approximately 65% of Iowa's roads are surfaced with aggregates composed of crushed limestone and/or gravel. Rural Iowan's regard these roads as a very important part of their lives. Therefore, the slide-tape presentation, "Maintaining Granular Surfac...

Road impacts on the Baca National Wildlife Refuge, Colorado, with emphasis on effects to surface- and shallow ground-water hydrology - A literature review

USGS Publications Warehouse

Andersen, Douglas C.

2007-01-01

A review of published research on unpaved road effects on surface-water and shallow ground-water hydrology was undertaken to assist the Baca National Wildlife Refuge, Colorado, in understanding factors potentially influencing refuge ecology. Few studies were found that addressed hydrological effects of roads on a comparable area of shallow slope in a semiarid region. No study dealt with road effects on surface- and ground-water supplies to ephemeral wetlands, which on the refuge are sustained by seasonal snowmelt in neighboring mountains. Road surfaces increase runoff, reduce infiltration, and serve as a sediment source. Roadbeds can interfere with normal surface- and ground-water flows and thereby influence the quantity, timing, and duration of water movement both across landscapes and through the soil. Hydrologic effects can be localized near the road as well as widespread and distant. The number, arrangement, and effectiveness of road-drainage structures (culverts and other devices) largely determine the level of hydrologic alteration produced by a road. Undesirable changes to natural hydrologic patterns can be minimized by considering potential impacts during road design, construction, and maintenance. Road removal as a means to restore desirable hydrologic conditions to landscapes adversely affected by roads has yet to be rigorously evaluated.

Analysis of Contraction Joint Width Influence on Load Stress of Pavement Panels

NASA Astrophysics Data System (ADS)

Gao, Wei; Cui, Wei; Sun, Wei

2018-05-01

The width of transverse contraction joint of the cement road varies with temperatures, which leads to changes in load transmission among plates of the road surface and affects load stress of the road plates. Three-dimensional element analysis software EverFE is used to address the relation between the contraction joint width and road surface load stress, revealing the impact of reducing contraction joint width. The results could be of critical value in maintaining road functions and extending the service life of cement road surfaces.

Assessing and Mapping of Road Surface Roughness based on GPS and Accelerometer Sensors on Bicycle-Mounted Smartphones

PubMed Central

Shen, Jie; Wan, Mi; Shi, Jiafeng

2018-01-01

The surface roughness of roads is an essential road characteristic. Due to the employed carrying platforms (which are often cars), existing measuring methods can only be used for motorable roads. Until now, there has been no effective method for measuring the surface roughness of un-motorable roads, such as pedestrian and bicycle lanes. This hinders many applications related to pedestrians, cyclists and wheelchair users. In recognizing these research gaps, this paper proposes a method for measuring the surface roughness of pedestrian and bicycle lanes based on Global Positioning System (GPS) and accelerometer sensors on bicycle-mounted smartphones. We focus on the International Roughness Index (IRI), as it is the most widely used index for measuring road surface roughness. Specifically, we analyzed a computing model of road surface roughness, derived its parameters with GPS and accelerometers on bicycle-mounted smartphones, and proposed an algorithm to recognize potholes/humps on roads. As a proof of concept, we implemented the proposed method in a mobile application. Three experiments were designed to evaluate the proposed method. The results of the experiments show that the IRI values measured by the proposed method were strongly and positively correlated with those measured by professional instruments. Meanwhile, the proposed algorithm was able to recognize the potholes/humps that the bicycle passed. The proposed method is useful for measuring the surface roughness of roads that are not accessible for professional instruments, such as pedestrian and cycle lanes. This work enables us to further study the feasibility of crowdsourcing road surface roughness with bicycle-mounted smartphones. PMID:29562731

A generalised model for traffic induced road dust emissions. Model description and evaluation

NASA Astrophysics Data System (ADS)

Berger, Janne; Denby, Bruce

2011-07-01

This paper concerns the development and evaluation of a new and generalised road dust emission model. Most of today's road dust emission models are based on local measurements and/or contain empirical emission factors that are specific for a given road environment. In this study, a more generalised road dust emission model is presented and evaluated. We have based the emissions on road, tyre and brake wear rates and used the mass balance concept to describe the build-up of road dust on the road surface and road shoulder. The model separates the emissions into a direct part and a resuspension part, and treats the road surface and road shoulder as two different sources. We tested the model under idealized conditions as well as on two datasets in and just outside of Oslo in Norway during the studded tyre season. We found that the model reproduced the observed increase in road dust emissions directly after drying of the road surface. The time scale for the build-up of road dust on the road surface is less than an hour for medium to heavy traffic density. The model performs well for temperatures above 0 °C and less well during colder periods. Since the model does not yet include salting as an additional mass source, underestimations are evident under dry periods with temperatures around 0 °C, under which salting occurs. The model overestimates the measured PM 10 (particulate matter less than 10 μm in diameter) concentrations under heavy precipitation events since the model does not take the amount of precipitation into account. There is a strong sensitivity of the modelled emissions to the road surface conditions and the current parameterisations of the effect of precipitation, runoff and evaporation seem inadequate.

Contribution of mucosal maltase-glucoamylase activities to mouse small intestinal starch alpha-glucogenesis

USDA-ARS?s Scientific Manuscript database

Digestion of starch requires activities provided by 6 interactive small intestinal enzymes. Two of these are luminal endo-glucosidases named alpha-amylases. Four are exo-glucosidases bound to the luminal surface of enterocytes. These mucosal activities were identified as 4 different maltases. Two ma...

Rapid road repair vehicle

DOEpatents

Mara, Leo M.

1998-01-01

Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find an the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was was heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past.

Rapid road repair vehicle

DOEpatents

Mara, L.M.

1998-05-05

Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find at the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was not heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past. 2 figs.

Wood chips for dust control on surface-mine haul roads

Treesearch

George P., Jr. Williams

1979-01-01

On a coal haul spur road where water sprinkling was the primary method of dust control, the duration of control was increased tenfold by covering the road surface with a layer of wood chips. The chip blanket prevented existing dust-size particles from being kicked up and swept into plumes by passing traffic, insulated the road surface against evaporation and protected...

An uptake of cationized ferritin by alveolar type I cells in airway-instilled goat lung: distribution of anionic sites on the epithelial surface.

PubMed

Atwal, O S; Viel, L; Minhas, K J

1990-07-01

The present study has investigated ultrastructural localization of anionic sites on the luminal surface of the alveolar epithelium of goat lung by direct airway instillation of cationized ferritin (CF) in the cranial lobe of the right lung through a bronchoscope. The cationic probe decorated preferentially the luminal plasmalemmal vesicles and plasmalemma proper of alveolar type I cell. This indicated the presence of highly charged anionic microdomains at these binding sites. The ligand was internalized in the free plasmalemmal vesicles of alveolar type I cell within 2 min. Heavy decoration of vesicles at 5 min of perfusion indicated that the amount of CF internalization increased with its concentration in the alveoli. It is suggested that exposure of alveolar surface to several gases of ruminal-origin induces changes in the surface charge of luminal plasmalemma of alveolar type I cells. The significance of these anionic plasmalemmal sites is discussed in relation to the adjustment of osmotic pressure gradient across the alveolar-capillary membrane of the ruminant lung.

Determination of the Wave Parameters from the Statistical Characteristics of the Image of a Linear Test Object

NASA Astrophysics Data System (ADS)

Weber, V. L.

2018-03-01

We statistically analyze the images of the objects of the "light-line" and "half-plane" types which are observed through a randomly irregular air-water interface. The expressions for the correlation function of fluctuations of the image of an object given in the form of a luminous half-plane are found. The possibility of determining the spatial and temporal correlation functions of the slopes of a rough water surface from these relationships is shown. The problem of the probability of intersection of a small arbitrarily oriented line segment by the contour image of a luminous straight line is solved. Using the results of solving this problem, we show the possibility of determining the values of the curvature variances of a rough water surface. A practical method for obtaining an image of a rectilinear luminous object in the light rays reflected from the rough surface is proposed. It is theoretically shown that such an object can be synthesized by temporal accumulation of the image of a point source of light rapidly moving in the horizontal plane with respect to the water surface.

Continuous hierarchical slope-aspect color display for parametric surfaces

NASA Technical Reports Server (NTRS)

Moellering, Harold J. (Inventor); Kimerling, A. Jon (Inventor)

1994-01-01

A method for generating an image of a parametric surface, such as the aspect of terrain which maximizes color contrast to permit easy discrimination of the magnitude, ranges, intervals or classes of a surface parameter while making it easy for the user to visualize the form of the surface, such as a landscape. The four pole colors of the opponent process color theory are utilized to represent intervals or classes at 90 degree angles. The color perceived as having maximum measured luminance is selected to portray the color having an azimuth of an assumed light source and the color showing minimum measured luminance portrays the diametrically opposite azimuth. The 90 degree intermediate azimuths are portrayed by unique colors of intermediate measured luminance, such as red and green. Colors between these four pole colors are used which are perceived as mixtures or combinations of their bounding colors and are arranged progressively between their bounding colors to have perceived proportional mixtures of the bounding colors which are proportional to the interval's angular distance from its bounding colors.

HOW FAR TO THE NEAREST ROAD?

EPA Science Inventory

Increases in impervious surface area lead to declines in chemical and biological indicators of water quality .Roads are an important aspect of impervious surface, and distance to roads is an indicator of the potential threat to aquatic and terrestrial ecosystems. Although roads a...

A model for investigating the influence of road surface texture and tyre tread pattern on rolling resistance

NASA Astrophysics Data System (ADS)

Hoever, Carsten; Kropp, Wolfgang

2015-09-01

The reduction of rolling resistance is essential for a more environmentally friendly road transportation sector. Both tyre and road design can be utilised to reduce rolling resistance. In both cases a reliable simulation tool is needed which is able to quantify the influence of design parameters on the rolling resistance of a tyre rolling on a specific road surface. In this work a previously developed tyre/road interaction model is extended to account for different tread patterns and for losses due to small-scale tread deformation. Calculated contact forces and tyre vibrations for tyre/road interaction under steady-state rolling are used to predict rolling losses in the tyre. Rolling resistance is calculated for a series of different tyre/road combinations. Results are compared with rolling resistance measurements. The agreement between simulations and measurements is generally very good. It is found that both the tyre structure and small-scale tread deformations contribute to the rolling losses. The small-scale contribution depends mainly on the road roughness profile. The mean profile depth of the road surface is identified to correlate very well with the rolling resistance. Additional calculations are performed for non-traditional rubberised road surfaces, however, with mixed results. This possibly indicates the existence of additional loss mechanisms for these surfaces.

Recognition and Classification of Road Condition on the Basis of Friction Force by Using a Mobile Robot

NASA Astrophysics Data System (ADS)

Watanabe, Tatsuhito; Katsura, Seiichiro

A person operating a mobile robot in a remote environment receives realistic visual feedback about the condition of the road on which the robot is moving. The categorization of the road condition is necessary to evaluate the conditions for safe and comfortable driving. For this purpose, the mobile robot should be capable of recognizing and classifying the condition of the road surfaces. This paper proposes a method for recognizing the type of road surfaces on the basis of the friction between the mobile robot and the road surfaces. This friction is estimated by a disturbance observer, and a support vector machine is used to classify the surfaces. The support vector machine identifies the type of the road surface using feature vector, which is determined using the arithmetic average and variance derived from the torque values. Further, these feature vectors are mapped onto a higher dimensional space by using a kernel function. The validity of the proposed method is confirmed by experimental results.

36 CFR 294.25 - Mineral activities in Idaho Roadless Areas.

Code of Federal Regulations, 2010 CFR

2010-07-01

... recommend, authorize, or consent to road construction, road reconstruction, or surface occupancy associated... construction or road reconstruction associated with mineral leases in Idaho Roadless Areas designated as Backcountry/Restoration. Surface use or occupancy without road construction or reconstruction is permissible...

Assessment of roadway surface conditions using onboard vehicle sensors : final report phase I.

DOT National Transportation Integrated Search

2015-03-01

Real-time assessment of road surface conditions can be used to provide valuable safety information to travelers when roads are slippery (e.g., contaminated roads, heavy rain, black ice, etc.). Identification of these hazardous surface conditions usin...

Investigating the road surface effect to the fatigue life of an automotive coil spring

NASA Astrophysics Data System (ADS)

Putra, T. E.; Husaini

2018-05-01

This work aims to estimate the life of a coil spring considering road surface profiles. Strain signals were measured by installing a strain gage at the highest stress location of the coil spring and then driving the vehicle on country and village roads. The village road gave high amplitudes containing spikes when the tire touched a curb, bump or pothole. These conditions contributed to a higher loading rate to the car component, contributing to shorter useful fatigue life, which was only 140 reversals of blocks. Driving on the village road resulted in a 6-times decrease in the useful fatigue life of the component in comparison to the country road. In conclusion, the village road caused stronger vibrations to the component because it has a rough surface; meanwhile, the country road provided lower vibrations because the road was smooth.

Dust emissions from unpaved roads on the Colorado Plateau

NASA Astrophysics Data System (ADS)

Duniway, M.; Flagg, C.; Belnap, J.

2013-12-01

On the Colorado Plateau, elevated levels of aeolian dust have become a major land management and policy concern due to its influence on climate, weather, terrestrial ecosystem dynamics, landscape development and fertility, melting of snow and ice, air quality, and human health. Most desert soil surfaces are stabilized by plants, rocks, and/or physical or biological soil crusts, but once disturbed, sediment production from these surfaces can increase dramatically. Road development and use is a common surface disturbing activity in the region. The extent and density of roads and road networks is rapidly increasing due to continued energy exploration, infrastructure development, and off-highway recreation activities. Though it is well known that unpaved roads produce dust, the relative contribution of dust from existing roads or the implications of future road development to regional dust loading is unknown. To address this need, we have initiated a multifaceted research effort to evaluating dust emissions from unpaved roads regionally. At 34 sites arranged across various road surfaces and soil textures in southeastern Utah, we are: 1) monitoring dust emissions, local wind conditions, and vehicle traffic and 2) evaluating fugitive dust potential using a portable wind tunnel and measuring road characteristics that affect dust production. We will then 3) develop a GIS-based model that integrates results from 1 & 2 to estimate potential dust contributions from current and future scenarios of regional road development. Passive, horizontal sediment traps were installed at three distances downwind from the road edge. One control trap was placed upwind of the samplers to account for local, non-road dust emissions. An electronic vehicle counter and anemometer were also installed at monitoring sites. Dust samples were collected every three months at fixed heights, 15 cm up to 100 cm above the soil surface, from March 2010 to the present. Threshold friction velocities (TFV), the minimum wind velocity required to initiate erosion, and sediment production were also quantified using a portable wind tunnel at monitoring sites. Additionally, numerous characteristics including gravel cover, particle-size distribution, soil compaction, and loose-erodible material were measured on road surfaces at monitoring sites. Preliminary results suggest that roads are an important regional dust source, as emissions from roads are comparable to non-road, rural sources that are being monitored concurrently. While gravel roads produce more dust per day on average, per vehicle emissions are larger on dirt roads. Dust flux decreases with distance from the road edge on all road types, however this decline is less pronounced on dirt roads. Portable wind tunnel results indicate that TFV is consistently lower on dirt versus gravel roads across all soil types. Fugitive dust flux is generally larger and more variable on dirt roads compared to gravel roads. Initial analyses suggest that several easily measurable road surface characteristics can potentially be used to predict both TFV and sediment production, including: total gravel cover, gravel particle-size classes, clay content, and road compaction. The relation between TFV and total gravel cover in particular appears to be non-linear, with TFV increasing rapidly above ~40% gravel cover.

Gas discharge headlights and visibility of coloured road signs.

PubMed

Venkatachalam, Kannan; Smith, George

2000-01-01

BACKGROUND: Automotive headlamps mostly use the tungsten halogen bulb but several years ago a new type of headlamp, the gas discharge bulb, was introduced. Because of the different spectral output of this type of lamp, there has been a suggestion that it may affect the colour recognition and sign conspicuity under night-time conditions. In this study, the visibility of the road signs is used to examine the effect of the gas discharge lamp's spectrum compared with that of the conventional halogen headlamp. METHODS: The spectral output of the lamps and the spectral reflectance of common-coloured road signs were measured using a Spectra-Pritchard spectroradiometer. Using luminous reflectance data, chromaticity co-ordinates and the colorimetric shift of the road signs, when illuminated by gas discharge lamps, were plotted using CIE x,y co-ordinate system. Colour rendering indices of the lamp were calculated using Munsell samples and road signs as proscribed by the CIE Publication. In addition, the visibility index of the road signs was calculated using Adrian's 'Visibility of Target' model. RESULTS: The gas discharge headlamp has more energy in the blue region and less energy in the red region of the spectrum than the halogen headlamp. The general colour rendering index of the gas discharge lamp is higher than that of the halogen lamp. When compared with daylight, all coloured road signs used in this study have less colorimetric shift when illuminated by the gas discharge headlamp than by the halogen headlamp. CONCLUSION: The result indicates that the gas discharge lamp, while having a very different spectrum from daylight or tungsten halogen lamps, should not have a deleterious effect on sign detection or recognition, when compared to daylight or tungsten halogen lamps.

Gastric mucosal protective mechanisms: roles of epithelial bicarbonate and mucus secretions.

PubMed

Garner, A; Flemström, G; Allen, A; Heylings, J R; McQueen, S

1984-01-01

Secretion of HCO3 (amounting to 2-10% of maximum H+ secretion) in conjunction with the adherent mucus gel layer (functioning as a mixing barrier) protects gastric mucosa from luminal acid by a process of surface neutralization. Gastric HCO3 secretion is augmented by cholinergic agonists, prostaglandins and low luminal pH. Ulcerogens attenuate HCO3 secretion although passive diffusion of alkali consequent upon an increase in mucosal permeability may mask these inhibitory actions. Studies in vitro indicate that HCO3 transport in the stomach is dependent on oxidative metabolism, carbonic anhydrase activity and involves a CL exchange mechanism. Mucus, synthesized and released from epithelial cells, adheres to the mucosal surface as a thin (less than 80 microns in rat) but continuous gel layer. Prostaglandins and carbachol induced release of preformed mucus and thereby increase thickness, whereas acute exposure to ulcerogens has little effect on overall dimensions of the surface mucus layer. Measurements of pH gradients adjacent to gastric mucosa indicate that the disposal of luminal H+ occurs by extracellular neutralization. However, the fall in pH at the apical cell membrane when luminal pH is low (pH 1.5) suggests that while a mucus-bicarbonate barrier comprises the first line of mucosal defence, other factors are involved in the overall process of mucosal protection in the stomach.

In Vivo Epithelial Wound Repair Requires Mobilization of Endogenous Intracellular and Extracellular Calcium*

PubMed Central

Aihara, Eitaro; Hentz, Courtney L.; Korman, Abraham M.; Perry, Nicholas P. J.; Prasad, Vikram; Shull, Gary E.; Montrose, Marshall H.

2013-01-01

We report that a localized intracellular and extracellular Ca2+ mobilization occurs at the site of microscopic epithelial damage in vivo and is required to mediate tissue repair. Intravital confocal/two-photon microscopy continuously imaged the surgically exposed stomach mucosa of anesthetized mice while photodamage of gastric epithelial surface cells created a microscopic lesion that healed within 15 min. Transgenic mice with an intracellular Ca2+-sensitive protein (yellow cameleon 3.0) report that intracellular Ca2+ selectively increases in restituting gastric epithelial cells adjacent to the damaged cells. Pretreatment with U-73122, indomethacin, 2-aminoethoxydiphenylborane, or verapamil inhibits repair of the damage and also inhibits the intracellular Ca2+ increase. Confocal imaging of Fura-Red dye in luminal superfusate shows a localized extracellular Ca2+ increase at the gastric surface adjacent to the damage that temporally follows intracellular Ca2+ mobilization. Indomethacin and verapamil also inhibit the luminal Ca2+ increase. Intracellular Ca2+ chelation (1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid/acetoxymethyl ester, BAPTA/AM) fully inhibits intracellular and luminal Ca2+ increases, whereas luminal calcium chelation (N-(2-hydroxyetheyl)-ethylendiamin-N,N,N′-triacetic acid trisodium, HEDTA) blocks the increase of luminal Ca2+ and unevenly inhibits late-phase intracellular Ca2+ mobilization. Both modes of Ca2+ chelation slow gastric repair. In plasma membrane Ca-ATPase 1+/− mice, but not plasma membrane Ca-ATPase 4−/− mice, there is slowed epithelial repair and a diminished gastric surface Ca2+ increase. We conclude that endogenous Ca2+, mobilized by signaling pathways and transmembrane Ca2+ transport, causes increased Ca2+ levels at the epithelial damage site that are essential to gastric epithelial cell restitution in vivo. PMID:24121509

In vivo epithelial wound repair requires mobilization of endogenous intracellular and extracellular calcium.

PubMed

Aihara, Eitaro; Hentz, Courtney L; Korman, Abraham M; Perry, Nicholas P J; Prasad, Vikram; Shull, Gary E; Montrose, Marshall H

2013-11-22

We report that a localized intracellular and extracellular Ca(2+) mobilization occurs at the site of microscopic epithelial damage in vivo and is required to mediate tissue repair. Intravital confocal/two-photon microscopy continuously imaged the surgically exposed stomach mucosa of anesthetized mice while photodamage of gastric epithelial surface cells created a microscopic lesion that healed within 15 min. Transgenic mice with an intracellular Ca(2+)-sensitive protein (yellow cameleon 3.0) report that intracellular Ca(2+) selectively increases in restituting gastric epithelial cells adjacent to the damaged cells. Pretreatment with U-73122, indomethacin, 2-aminoethoxydiphenylborane, or verapamil inhibits repair of the damage and also inhibits the intracellular Ca(2+) increase. Confocal imaging of Fura-Red dye in luminal superfusate shows a localized extracellular Ca(2+) increase at the gastric surface adjacent to the damage that temporally follows intracellular Ca(2+) mobilization. Indomethacin and verapamil also inhibit the luminal Ca(2+) increase. Intracellular Ca(2+) chelation (1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/acetoxymethyl ester, BAPTA/AM) fully inhibits intracellular and luminal Ca(2+) increases, whereas luminal calcium chelation (N-(2-hydroxyetheyl)-ethylendiamin-N,N,N'-triacetic acid trisodium, HEDTA) blocks the increase of luminal Ca(2+) and unevenly inhibits late-phase intracellular Ca(2+) mobilization. Both modes of Ca(2+) chelation slow gastric repair. In plasma membrane Ca-ATPase 1(+/-) mice, but not plasma membrane Ca-ATPase 4(-/-) mice, there is slowed epithelial repair and a diminished gastric surface Ca(2+) increase. We conclude that endogenous Ca(2+), mobilized by signaling pathways and transmembrane Ca(2+) transport, causes increased Ca(2+) levels at the epithelial damage site that are essential to gastric epithelial cell restitution in vivo.

Role of urban surface roughness in road-deposited sediment build-up and wash-off

NASA Astrophysics Data System (ADS)

Zhao, Hongtao; Jiang, Qian; Xie, Wenxia; Li, Xuyong; Yin, Chengqing

2018-05-01

Urban road surface roughness is one of the most important factors in estimation of surface runoff loads caused by road-deposited sediment (RDS) wash-off and design of its control measures. However, because of a lack of experimental data to distinguish the role of surface roughness, the effects of surface roughness on RDS accumulation and release are not clear. In this study, paired asphalt and concrete road surfaces and rainfall simulation designs were used to distinguish the role of surface roughness in RDS build-up and wash-off. Our results showed that typical asphalt surfaces often have higher depression depths than typical concrete surfaces, indicating that asphalt surfaces are relatively rougher than concrete surface. Asphalt surfaces can retain a larger RDS amount, relative higher percentage of coarser particles, larger RDS wash-off loads, and lower wash-off percentage, than concrete surfaces. Surface roughness has different effects in RDS motilities with different particle sizes during rainfall runoff, and the settleable particles (44-149 μm) were notably influenced by it. Furthermore, the first flush phenomenon tended to be greater on relatively smooth surfaces than relatively rough surfaces. Overall, surface roughness plays an important role in influencing the complete process of RDS build-up and wash-off on different road characteristics.

All-terrain vehicle fatalities on paved roads, unpaved roads, and off-road: Evidence for informed roadway safety warnings and legislation.

PubMed

Denning, Gerene M; Jennissen, Charles A

2016-05-18

All-terrain vehicles (ATVs) are designed for off-highway use only, and many of their features create increased risk with roadway travel. Over half of all ATV-related fatalities occur on roadways, and nonfatal roadway crashes result in more serious injuries than those off the road. A number of jurisdictions have passed or have considered legislation allowing ATVs on public roadways, sometimes limiting them to those unpaved, arguing that they are safe for ATVs. However, no studies have determined the epidemiology of ATV-related fatalities on different road surface types. The objective of the study was to compare ATV-related deaths on paved versus unpaved roads and to contrast them with off-road fatalities. Retrospective descriptive and multivariable analyses were performed using U.S. Consumer Product Safety Commission fatality data from 1982 through 2012. After 1998, ATV-related deaths increased at twice the rate on paved versus unpaved roads. Still, 42% of all roadway deaths during the study period occurred on unpaved surfaces. States varied considerably, ranging from 18% to 79% of their ATV-related roadway deaths occurring on unpaved roads. Paved road crashes were more likely than those on unpaved surfaces to involve males, adolescents and younger adults, passengers, and collisions with other vehicles. Both the pattern of other vehicles involved in collisions and which vehicle hit the other were different for the 2 road types. Alcohol use was higher, helmet use was lower, and head injuries were more likely in paved versus unpaved roadway crashes. However, head injuries still occurred in 76% of fatalities on unpaved roads. Helmets were associated with lower proportions of head injuries among riders, regardless of road surface type. Relative to off-road crashes, both paved and unpaved roads were more likely to involve collisions with another vehicle. The vast majority of roadway crashes, however, did not involve a traffic collision on either paved or unpaved roads. Although differences were observed between paved and unpaved roads, our results show that riding on either represented significantly greater dangers than riding off the road. Many vehicle warnings specifically mention the risks of paved but not unpaved roads, yet we found 23 states with half or more of their roadway deaths on unpaved surfaces. Safety warnings should explicitly state the dangers of roadway riding regardless of surface type. These data further support laws/ordinances greatly restricting ATV riding on all types of public roadways.

Percutaneous fiber optic angioscopy of the left ventricle in patients with rheumatic valvular disease

NASA Astrophysics Data System (ADS)

Hirose, Junichi; Oshima, Tomomitsu; Fujimori, Yoshiharu; Uchida, Yasumi

1993-05-01

Recent advances in fiberoptic technology enabled us to observe percutaneously the cardiac chambers and valves. We examined left ventricular luminal and valvular changes by percutaneous fiberoptic angioscopy in patients with rheumatic valvular disease. Six patients with echocardiographic rheumatic changes in the mitral valves, underwent angioscopy during routine cardiac catheterization. The fiberscope 4.2 F in diameter, and the guiding catheter 9 F in external diameter with an inflatable balloon around the distal most tip were used for angioscopy. The left ventricular endocardial surface was diffusely white in color or white and brown in mosaic fashion. Echocardiography and angiography had low sensitivity for detecting the changes of the left ventricular luminal surface. Whitish changes which were observed by angioscopy were not related to the indices derived from echocardiography and angiography. The results indicate the possibility of percutaneous angioscopy in detecting left ventricular luminal changes in patients with rheumatic valvular disease.

The epidermal growth factor receptor (EGF-R) is present on the basolateral, but not the apical, surface of enterocytes in the human gastrointestinal tract.

PubMed Central

Playford, R J; Hanby, A M; Gschmeissner, S; Peiffer, L P; Wright, N A; McGarrity, T

1996-01-01

BACKGROUND: While it is clear that luminal epidermal growth factor (EGF) stimulates repair of the damaged bowel, its significance in maintaining normal gut growth remains uncertain. If EGF is important in maintaining normal gut growth, the EGF receptor (EGF-R) should be present on the apical (luminal) surface in addition to the basolateral surface. AIMS/SUBJECTS/METHODS: This study examined the distribution of the EGF-R in the epithelium throughout the human gastro-intestinal tract using immunohistochemistry, electron microscopy, and western blotting of brush border preparations. RESULTS: Immunostaining of the oesophagus showed circumferential EGF-R positivity in the cells of the basal portions of the stratified squamous epithelium but surface cells were EGF-R negative. In the normal stomach, small intestine, and colon, immunostaining localised the receptor to the basolateral surface with the apical membranes being consistently negative. EGF-R positivity within the small intestine appeared to be almost entirely restricted to the proliferative (crypt) region. Western blotting demonstrated a 170 kDa protein in whole tissue homogenates but not in the brush border vesicle preparations. CONCLUSIONS: As the EGF-R is located only on the basolateral surfaces in the normal adult gastrointestinal tract, the major role of luminal EGF is probably to stimulate repair rather than to maintain normal gut growth. Images Figure 1 Figure 2 Figure 3 PMID:8977341

Modeling changes in rill erodibility and critical shear stress on native surface roads

Treesearch

Randy B. Foltz; Hakjun Rhee; William J. Elliot

2008-01-01

This study investigated the effect of cumulative overland flow on rill erodibility and critical shear stress on native surface roads in central Idaho. Rill erodibility decreased exponentially with increasing cumulative overland flow depth; however, critical shear stress did not change. The study demonstrated that road erodibility on the studied road changes over the...

Epic Erosion Along Newly Constructed Roads in Yunnan, China

NASA Astrophysics Data System (ADS)

Sidle, R. C.; Kono, Y.; Yamaguchi, T.

2007-05-01

The recent expansion and construction of new mountain roads in northwestern Yunnan Province, China, poses problems related to landslides and surface erosion that are impacting the headwaters of three great river systems: the Salween, Mekong, and Yangtze. Many of these newer roads are simply blasted into unstable hillsides with virtually no attention paid to optimal road location, construction practices, and erosion control measures. During summer 2006, seven people traveling in a minivan along a newly constructed road to Weixi were killed by a landslide. A survey conducted along a this 23.5 km road section (4 yr old) in the headwaters of the Mekong River revealed epic levels of landslides and surface erosion. Based on a preliminary survey, the road erosion was categorized as moderately severe, severe, or very severe, and a representative 0.75 to 0.90 km stretch of road was then surveyed for both landslide (based on dimensional analysis) and surface erosion (based on soil pedestal height). Average mass wasting rates (9608 t ha-1yr-1) along the road were more than 13 times higher than surface erosion (720 t ha-1yr-1), even though surface erosion rates are among the highest reported for disturbed lands. Dry ravel constituted a minor proportion of the mass wasting: 4% in the severe erosion section of the road and 0.5-0.6% in the moderately severe and very severe sections. For the very severe erosion road section (6 km long), estimated landslide erosion alone was > 33,000 t ha- 1yr-1, 620 times the average landslide erosion from forest roads built in unstable terrain in western North America. These levels of landslide erosion along the Weixi road are the highest ever documented and are somewhat representative of erosion along new mountain roads in this region of Yunnan. Sediment produced from roads is highly connected to fluvial systems; we estimate that 80-95% of the direct sediment contributions into the headwaters of these rivers are attributable to road erosion and landslides. These epic sediment loads represent cumulative effects that may persist in these important transnational rivers for decades.

Radiation properties of two types of luminous textile devices containing plastic optical fibers

NASA Astrophysics Data System (ADS)

Selm, Bärbel; Rothmaier, Markus

2007-05-01

Luminous textiles have the potential to satisfy a need for thin and flexible light diffusers for treatment of intraoral cancerous tissue. Plastic optical fibers (POF) with diameters of 250 microns and smaller are used to make the textiles luminous. Usually light is supplied to the optical fiber at both ends. On the textile surface light emission occurs in a woven structure via damaged straight POFs, whereas the embroidered structure radiates the light out of macroscopically bent POFs. We compared the optical properties of these two types of textile diffusers using red light laser for the embroidery and light emitting diode (LED) for the woven structure as light sources, and found efficiencies for the luminous areas of the two samples of 19 % (woven) and 32 % (embroidery), respectively. It was shown that the efficiency can be greatly improved using an aluminium backing. Additional scattering layers lower the fluence rate by around 30 %. To analyse the homogeneity we took a photo of the illuminated surface using a 3CCD camera and found, for both textiles, a slightly skewed distribution of the dark and bright pixels. The interquartile range of brightness distribution of the embroidery is more than double as the woven structure.

Sedimentation associated with forest road surfacing in a bottomland hardwood ecosystem

Treesearch

Robert B. Rummer; Bryce Stokes; Graeme Lockaby

1997-01-01

Access systems are a necessary element of resource production in bottomland hardwood sites. However, road building may have a detrimental effect on hydrologic function of the site. This report describes initial results of a study designed to examine the effect of different road surfacing treatments on water quality.Four Surfacing treatments installed on two...

Statistical classification of road pavements using near field vehicle rolling noise measurements.

PubMed

Paulo, Joel Preto; Coelho, J L Bento; Figueiredo, Mário A T

2010-10-01

Low noise surfaces have been increasingly considered as a viable and cost-effective alternative to acoustical barriers. However, road planners and administrators frequently lack information on the correlation between the type of road surface and the resulting noise emission profile. To address this problem, a method to identify and classify different types of road pavements was developed, whereby near field road noise is analyzed using statistical learning methods. The vehicle rolling sound signal near the tires and close to the road surface was acquired by two microphones in a special arrangement which implements the Close-Proximity method. A set of features, characterizing the properties of the road pavement, was extracted from the corresponding sound profiles. A feature selection method was used to automatically select those that are most relevant in predicting the type of pavement, while reducing the computational cost. A set of different types of road pavement segments were tested and the performance of the classifier was evaluated. Results of pavement classification performed during a road journey are presented on a map, together with geographical data. This procedure leads to a considerable improvement in the quality of road pavement noise data, thereby increasing the accuracy of road traffic noise prediction models.

Numerical reproduction and explanation of road surface mirages under grazing-angle scattering.

PubMed

Lu, Jia; Zhou, Huaichun

2017-07-01

The mirror-like reflection image of the road surface under grazing-angle scattering can be easily observed in daily life. It was suggested that road surface mirages may occur due to a light-enhancing effect of the rough surface under grazing-angle scattering. The main purpose of this work is to explain the light-enhancing mechanism of rough surfaces under grazing-angle scattering. The off-specular reflection from a random rough magnesium oxide ceramic surface is analyzed by using the geometric optics approximation method. Then, the geometric optics approximation method is employed to develop a theoretical model to predict the observation effect of the grazing-angle scattering phenomenon of the road surface. The rough surface is assumed to consist of small-scale rough surface facets. The road surface mirage is reproduced from a large number of small-scale rough surface facets within the eye's resolution limit at grazing scattering angles, as the average bidirectional reflectance distribution function value at the bright location is about twice that of the surface in front of the mirage. It is suggested that the light-enhancing effect of the rough surface under grazing-angle scattering is not proper to be termed as "off-specular reflection," since it has nothing to do with the "specular" direction with respect to the incident direction.

Evolving Our Evaluation of Luminous Environments

NASA Technical Reports Server (NTRS)

Clark, Toni

2016-01-01

The advance in solid state light emitting technologies and optics for lighting and visual communication necessitates the evaluation of how NASA envisions spacecraft lighting architectures and how NASA uses industry standards for the design and evaluation of lighting systems. Current NASA lighting standards and requirements for existing architectures focus on the separate ability of a lighting system to throw light against a surface or the ability of a display system to provide the appropriate visual contrast. This project investigated large luminous surface lamps as an alternative or supplement to overhead lighting. The efficiency of the technology was evaluated for uniformity and power consumption.

Influence of high ambient illuminance and display luminance on readability and subjective preference

NASA Astrophysics Data System (ADS)

De Moor, Katrien; Andrén, Börje; Guo, Yi; Brunnström, Kjell; Wang, Kun; Drott, Anton; Hermann, David S.

2015-03-01

Many devices, such as tablets, smartphones, notebooks, fixed and portable navigation systems are used on a (nearly) daily basis, both in in- and outdoor environments. It is often argued that contextual factors, such as the ambient illuminance in relation to characteristics of the display (e.g., surface treatment, screen reflectance, display luminance …) may have a strong influence on the use of such devices and corresponding user experiences. However, the current understanding of these influence factors is still rather limited. In this work, we therefore focus in particular on the impact of lighting and display luminance on readability, visual performance, subjective experience and preference. A controlled lab study (N=18) with a within-subjects design was performed to evaluate two car displays (one glossy and one matte display) in conditions that simulate bright outdoor lighting conditions. Four ambient luminance levels and three display luminance settings were combined into 7 experimental conditions. More concretely, we investigated for each display: (1) whether and how readability and visual performance varied with the different combinations of ambient luminance and display luminance and (2) whether and how they influenced the subjective experience (through self-reported valence, annoyance, visual fatigue) and preference. The results indicate a limited, yet negative influence of increased ambient luminance and reduced contrast on visual performance and readability for both displays. Similarly, we found that the self-reported valence decreases and annoyance and visual fatigue increase as the contrast ratio decreases and ambient luminance increases. Overall, the impact is clearer for the matte display than for the glossy display.

Effectiveness of a Coral-Derived Surfacing Material for Reducing Sediment Production on Unpaved Roads, Schoffield Barracks, Oahu, Hawaii

NASA Astrophysics Data System (ADS)

Ziegler, Alan D.; Sutherland, Ross A.

2006-01-01

This study evaluated the effectiveness of two application rates of a coral-derived surfacing material for both traffic and nontraffic road conditions using simulated rainfall (110-120 mm h-1 for 30-90 min) on 0.75-m (wide) × 5.0-m (long) plots of similar slope (roughly 0.1 m m-1). The coral is a locally available material that has been applied to unpaved roads surfaces on Schoffield Barracks, Oahu, Hawaii (USA), where this experiment was conducted. The simulations show that compared with a bare control plot, the coral-based surface application rates of 80 and 160 kg m-2 (equivalent to only 10- and 20-mm thicknesses) reduced road sediment production by 75% and 95%, respectively, for nontraffic conditions. However, after two passes of the research vehicle during wet conditions, sediment production rates for the two coral treatments were not significantly different from those on the bare road plots. The overall effectiveness of the coral-derived surfacing material is unsatisfactory, primarily because the on-road surface thickness associated with the application rates tested was too small. These rates were selected to bracket those applied to training roads in the study area. Furthermore, the composition of the coral-based material does not facilitate the development of a sealed, erosion-resistant surface. When applied at the low rates tested, the coral material breaks down under normal traffic conditions, thereby losing its ability to counter shearing forces exerted by overland flow on long hillslopes where erosion measures are most needed. These simulations, combined with observations on roads in the study area, indicate that this material is not an appropriate road surfacing material for the site—at least for the low application rates examined. These results are preliminary; extended testing of higher applications rates at the hillslope scale under natural climate and traffic conditions is needed to better judge the effectiveness of this material over time.

Effectiveness of a coral-derived surfacing material for reducing sediment production on unpaved roads, Schoffield barracks, Oahu, Hawaii.

PubMed

Ziegler, Alan D; Sutherland, Ross A

2006-01-01

This study evaluated the effectiveness of two application rates of a coral-derived surfacing material for both traffic and nontraffic road conditions using simulated rainfall (110-120 mm h(-1) for 30-90 min) on 0.75-m (wide) x 5.0-m (long) plots of similar slope (roughly 0.1 m m(-1)). The coral is a locally available material that has been applied to unpaved roads surfaces on Schoffield Barracks, Oahu, Hawaii (USA), where this experiment was conducted. The simulations show that compared with a bare control plot, the coral-based surface application rates of 80 and 160 kg m(-2) (equivalent to only 10- and 20-mm thicknesses) reduced road sediment production by 75% and 95%, respectively, for nontraffic conditions. However, after two passes of the research vehicle during wet conditions, sediment production rates for the two coral treatments were not significantly different from those on the bare road plots. The overall effectiveness of the coral-derived surfacing material is unsatisfactory, primarily because the on-road surface thickness associated with the application rates tested was too small. These rates were selected to bracket those applied to training roads in the study area. Furthermore, the composition of the coral-based material does not facilitate the development of a sealed, erosion-resistant surface. When applied at the low rates tested, the coral material breaks down under normal traffic conditions, thereby losing its ability to counter shearing forces exerted by overland flow on long hillslopes where erosion measures are most needed. These simulations, combined with observations on roads in the study area, indicate that this material is not an appropriate road surfacing material for the site-at least for the low application rates examined. These results are preliminary; extended testing of higher applications rates at the hillslope scale under natural climate and traffic conditions is needed to better judge the effectiveness of this material over time.

Grip Analysis of Road Surface and Tire Footprint Using FEM

NASA Astrophysics Data System (ADS)

Sabri, M.; Abda, S.

2018-02-01

Road grip involve a touch between road pavement and the tire tread pattern. The load bearing surface, which depends on pavement roughness and local pressures in the contact patch. This research conducted to develop a Finite element model for simulating the experimentally testing of asphalt in Jl. AH Nasution Medan, North Sumatera Indonesia base on the value of grip coefficient from various tire loads and the various speed of the vehicle during contact to the road. A tire model and road pavement are developed for the analyses the geometry of tire footprint. The results showed that the greater the mass of car will increase grip coefficient. The coefficient of grip on the road surface contact trough the tire footprint strongly influence the kinetic coefficient of friction at certain speeds. Experimentally show that Concrete road grip coefficient of more than 34% compared to the asphalt road at the same IRI parameters (6-8). Kinetic friction coefficient more than 0.33 was obtained in a asphalt path at a speed of 30-40 Km/hour.

Method and apparatus for controlling an earthworking implement to preserve a crown on a road surface

NASA Technical Reports Server (NTRS)

Lundquist, Steve D. (Inventor); Staub, Michael D. (Inventor); Alster, Louis G. (Inventor)

1999-01-01

A method and apparatus for controlling an earthworking implement on an earthworking machine to preserve a crown on the surface of a road, including determining the position of the crown on the road surface, choosing a sloped grade on one side of the crown, positioning the earthworking implement on the sloped grade so that a first end of the earthworking implement is on the road surface. The processor determines a desired position of a second end of the earthworking implement so that the second end overlaps the crown and the earthworking implement does not cut the crown.

Meal-stimulated release of methionine-enkephalin into the canine jejunal lumen.

PubMed Central

Money, S R; Petroianu, A; Gintzler, A R; Jaffe, B M

1988-01-01

Application of enkephalins to the luminal surface of the bowel augments intestinal absorption. However, to date, endogenous enkephalins have not been demonstrated within intestinal luminal fluid. To determine whether enkephalins are present in the intestinal lumen, five adult dogs had 25-cm chronic jejunal Thiry-Vella loops constructed. Dogs were studied in the awake, fasted state. Jejunal loops were perfused with isoosmotic, neutral Krebs buffer containing protease inhibitors. After basal sampling, the dogs received a high fat meat meal. Collections were made during the meal and for 60 min postprandially. Luminal met-enkephalin levels were determined by radioimmunoassay and confirmed by HPLC. HPLC separation of luminal samples demonstrated two immunoreactive peaks which co-eluted with pure met-enkephalin and met-enkephalin-sulfoxide. Basal met-enkephalin outputs averaged 52 +/- 13 ng/min. The meal significantly increased mean luminal met-enkephalin output to 137 +/- 71 ng/min. During the initial 20-min postprandial period, output remained elevated (180 +/- 73 ng/min), after which it returned to basal levels. We conclude that met-enkephalin is present in the jejunal lumen, and that luminal release of this opioid is augmented by a meal. Images PMID:3343342

10 CFR 32.101 - Schedule B-prototype tests for luminous safety devices for use in aircraft.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Schedule B-prototype tests for luminous safety devices for... thermometer. (d) Shock test. The device shall be dropped upon a concrete or iron surface in a 3-foot free gravitational fall, or shall be subjected to equivalent treatment in a test device simulating such a free fall...

Effect of contiguity and figure-ground organization on the area rule of lightness.

PubMed

Boyaci, Huseyin; Simşek, Mahru Kobal; Subaşı, Ece

2014-11-25

In a simple two-dimensional (2D) display composed of two uniform surfaces with different luminances, the lightness of the darker surface varies as a function of its relative area while its luminance is held constant (Gilchrist & Radonjić, 2009; Li & Gilchrist, 1999). This phenomenon is known as the area rule of lightness, and although it is extensively studied in the literature, the underlying principles are still largely unknown. Here, using computer-generated stimuli, we investigated the effects of contiguity and figure-ground organization on the area rule of lightness. Stimuli were 2D disks composed of radial sectors with high (25 cd/m2) or low (8 cd/m2) luminance. On each trial, observers judged the lightness of the sectors by adjusting the luminance of a matching patch. Four conditions were tested. In the contiguous condition, there were one dark and one light sector; in the noncontiguous condition, both the light and dark surfaces were split into four equal radial sectors. Figure and ground conditions were generated by adding small contextual elements to the stimulus. We found that the area rule applied under all conditions; however, the functional form of the effect showed marked differences across conditions. Taken together, our results show that both high-level (e.g., perceptual grouping, figure-ground organization) and low-level (e.g., spatial-summation) mechanisms play a role in the area rule of lightness. © 2014 ARVO.

Photometric optimization and comparison of hybrid white LEDs for mesopic road lighting.

PubMed

Zhang, Chuanwen; Xiao, Licai; Zhong, Ping; He, Guoxing

2018-06-01

The photometric model for the mesopic luminous efficacy (LE m ) of hybrid white LEDs, including the radiant efficiency of both blue and red LEDs as well as the overall quantum efficiency of the phosphor layer or the quantum dot (QD) film, was developed. The optimal spectral parameters of integrated with quantum dots (QD-WLED), phosphor-converted white LED (pc-WLED) with red LEDs instead of red phosphor (pc/R WLED) for both color fidelity index (R f ) and color rendering index (R a ) above 70, 80, and 90 at correlated color temperatures of 2700-6500 K were obtained by maximizing the average LE m of four road lighting standards. By comparing among pc-WLED, QD-WLED, and pc/R WLED, it was suggested that the pc/R WLEDs make strong candidates for mesopic road lighting. The requirements of the overall efficiency of QD film were presented if the QD-WLEDs were competitive to the pc-WLEDs. Finally, the three real pc/R WLEDs with both R f and R a about 80 at CCTs of 2982 K, 4560 K, and 5683 K were demonstrated.

An empirical basis for Mach bands

PubMed Central

Lotto, R. Beau; Williams, S. Mark; Purves, Dale

1999-01-01

Mach bands, the illusory brightness maxima and minima perceived at the initiation and termination of luminance gradients, respectively, are generally considered a direct perceptual manifestation of lateral inhibitory interactions among retinal or other lower order visual neurons. Here we examine an alternative explanation, namely that Mach bands arise as a consequence of real-world luminance gradients. In this first of two companion papers, we analyze the natural sources of luminance gradients, demonstrating that real-world gradients arising from curved surfaces are ordinarily adorned by photometric highlights and lowlights in the position of the illusory bands. The prevalence of such gradients provides an empirical basis for the generation of this perceptual phenomenon. PMID:10220450

Modeling the microstructure of surface by applying BRDF function

NASA Astrophysics Data System (ADS)

Plachta, Kamil

2017-06-01

The paper presents the modeling of surface microstructure using a bidirectional reflectance distribution function. This function contains full information about the reflectance properties of the flat surfaces - it is possible to determine the share of the specular, directional and diffuse components in the reflected luminous stream. The software is based on the authorial algorithm that uses selected elements of this function models, which allows to determine the share of each component. Basing on obtained data, the surface microstructure of each material can be modeled, which allows to determine the properties of this materials. The concentrator directs the reflected solar radiation onto the photovoltaic surface, increasing, at the same time, the value of the incident luminous stream. The paper presents an analysis of selected materials that can be used to construct the solar concentrator system. The use of concentrator increases the power output of the photovoltaic system by up to 17% as compared to the standard solution.

Trypanosoma cruzi TcSMUG L-surface mucins promote development and infectivity in the triatomine vector Rhodnius prolixus.

PubMed

Gonzalez, Marcelo S; Souza, Marcela S; Garcia, Eloi S; Nogueira, Nadir F S; Mello, Cícero B; Cánepa, Gaspar E; Bertotti, Santiago; Durante, Ignacio M; Azambuja, Patrícia; Buscaglia, Carlos A

2013-11-01

TcSMUG L products were recently identified as novel mucin-type glycoconjugates restricted to the surface of insect-dwelling epimastigote forms of Trypanosoma cruzi, the etiological agent of Chagas disease. The remarkable conservation of their predicted mature N-terminal region, which is exposed to the extracellular milieu, suggests that TcSMUG L products may be involved in structural and/or functional aspects of the interaction with the insect vector. Here, we investigated the putative roles of TcSMUG L mucins in both in vivo development and ex vivo attachment of epimastigotes to the luminal surface of the digestive tract of Rhodnius prolixus. Our results indicate that the exogenous addition of TcSMUG L N-terminal peptide, but not control T. cruzi mucin peptides, to the infected bloodmeal inhibited the development of parasites in R. prolixus in a dose-dependent manner. Pre-incubation of insect midguts with the TcSMUG L peptide impaired the ex vivo attachment of epimastigotes to the luminal surface epithelium, likely by competing out TcSMUG L binding sites on the luminal surface of the posterior midgut, as revealed by fluorescence microscopy. Together, these observations indicate that TcSMUG L mucins are a determinant of both adhesion of T. cruzi epimastigotes to the posterior midgut epithelial cells of the triatomine, and the infection of the insect vector, R. prolixus.

Brightness and transparency in the early visual cortex.

PubMed

Salmela, Viljami R; Vanni, Simo

2013-06-24

Several psychophysical studies have shown that transparency can have drastic effects on brightness and lightness. However, the neural processes generating these effects have remained unresolved. Several lines of evidence suggest that the early visual cortex is important for brightness perception. While single cell recordings suggest that surface brightness is represented in the primary visual cortex, the results of functional magnetic resonance imaging (fMRI) studies have been discrepant. In addition, the location of the neural representation of transparency is not yet known. We investigated whether the fMRI responses in areas V1, V2, and V3 correlate with brightness and transparency. To dissociate the blood oxygen level-dependent (BOLD) response to brightness from the response to local border contrast and mean luminance, we used variants of White's brightness illusion, both opaque and transparent, in which luminance increments and decrements cancel each other out. The stimuli consisted of a target surface and a surround. The surround luminance was always sinusoidally modulated at 0.5 Hz to induce brightness modulation to the target. The target luminance was constant or modulated in counterphase to null brightness modulation. The mean signal changes were calculated from the voxels in V1, V2, and V3 corresponding to the retinotopic location of the target surface. The BOLD responses were significantly stronger for modulating brightness than for stimuli with constant brightness. In addition, the responses were stronger for transparent than for opaque stimuli, but there was more individual variation. No interaction between brightness and transparency was found. The results show that the early visual areas V1-V3 are sensitive to surface brightness and transparency and suggest that brightness and transparency are represented separately.

Influencing factors on the visibility of surface distresses

NASA Astrophysics Data System (ADS)

Smęt, Wojciech; Skakuj, Marek

2018-05-01

A systematic and future-oriented maintenance management requires quality-assured data regarding the condition of the roadway. An important characteristic for assessing the condition of the road surface are cracks [1]. Experience has proven that the road surface temperature and residual humidity can influence the visibility of cracks. To investigate and quantify these influencing factors in more detail, the Federal Ministry of Transport and Digital Infrastructure has implemented a comprehensive research project [2], during which several measurement campaigns were carried out at different seasons and at different temperatures and humidity degrees of the road surface. The visibility of the cracks was assessed using the German approach ZTV ZEB-StB [3]. After evaluating the cracks, the data was synchronized and the network allocation of the geo-referenced raw data was realized. The relevant condition performance indicators were calculated subsequently. For each evaluation section of 100 meters length, the mean road surface temperature was calculated and, if available, the type and year of construction of the surface course was determined. The evaluated data was visualized to establish correlations between the data and the influencing factors. For the statistical analysis of the results, a total of six comparative scenarios were defined in which the influencing factors of road surface temperature and residual humidity were assessed. This paper documents the results of the research project. In order to obtain a uniform and comparable picture of the condition of the road surface over the years and thus to be able to observe the aging process of the road surface, the measurement campaigns are to be carried out under defined conditions. The research project included proposals for defining and further specifying the measurement conditions.

Differences in Surface Water Quality Draining Four Road Surface Types in the Southern Appalachians

Treesearch

Barton D. Clinton; James M. Vose

2003-01-01

Improved and unimproved roads can be the primary source of stream sediment in forested watersheds. We assessed differences in production of total suspended solids (TSS; ppm) from four road sulfate conditions in a Southern Appalachian watershed: (1) a 2-yr-old paved surface (P), (2) an improved gravel sulfate with controlled drainage and routine maintenance (RG), (3) an...

30 CFR 717.14 - Backfilling and grading of road cuts, mine entry area cuts, and other surface work areas.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Backfilling and grading of road cuts, mine entry area cuts, and other surface work areas. 717.14 Section 717.14 Mineral Resources OFFICE OF SURFACE... MINING GENERAL PERFORMANCE STANDARDS § 717.14 Backfilling and grading of road cuts, mine entry area cuts...

Road surface erosion on the Jackson Demonstration State Forest: results of a pilot study

Treesearch

Brian Barrett; Rosemary Kosaka; David. Tomberlin

2012-01-01

This paper presents results of a 3 year pilot study of surface erosion on forest roads in the Jackson Demonstration State Forest in California’s coastal redwood region. Ten road segments representing a range of surface, grade, and ditch conditions were selected for the study. At each segment, settling basins with tipping buckets were installed to measure...

The use of screening effects in modelling route-based daytime road surface temperature

NASA Astrophysics Data System (ADS)

Hu, Yumei; Almkvist, Esben; Lindberg, Fredrik; Bogren, Jörgen; Gustavsson, Torbjörn

2016-07-01

Winter road maintenance is essential for road safety. Accurate predictions of the road surface temperature (RST) and conditions can enhance the efficiency of winter road maintenance. Screening effects, which encompass shading effects and the influence of the sky-view factor ( ψ s ), influence RST distributions because they affect road surface radiation fluxes. In this work, light detection and ranging (Lidar) data are used to derive shadow patterns and ψ s values, and the resulting shadow patterns are used to model route-based RST distributions along two stretches of road in Sweden. The shading patterns and road surface radiation fluxes calculated from the Lidar data generally agreed well with measured RST values. Variation in land use types and the angle between the road direction and solar azimuth may introduce uncertainties, and accounting for these factors may improve the results obtained in certain cases. A simple shading model that only accounts for the direct radiation at the instant of measurement is often sufficient to provide reasonably accurate RST estimates. However, in certain cases, such as those involving measurements close to sunset, it is important to consider the radiation accumulated over several hours. The inclusion of ψ s improves the model performance even more in such cases. Overall, RST models based on the accumulated direct shortwave radiation offered an optimal balance of simplicity and accuracy. General radiation models were built for country road and highway environments, explaining up to 70 and 65 %, respectively, of the observed variation in RST along the corresponding stretches of road.

Identifying critical road geometry parameters affecting crash rate and crash type.

PubMed

Othman, Sarbaz; Thomson, Robert; Lannér, Gunnar

2009-10-01

The objective of this traffic safety investigation was to find critical road parameters affecting crash rate (CR). The study was based on crash and road maintenance data from Western Sweden. More than 3000 crashes, reported from 2000 to 2005 on median-separated roads, were collected and combined with road geometric and surface data. The statistical analysis showed variations in CR when road elements changed confirming that road characteristics affect CR. The findings indicated that large radii right-turn curves were more dangerous than left curves, in particular, during lane changing manoeuvres. However sharper curves are more dangerous in both left and right curves. Moreover, motorway carriageways with no or limited shoulders have the highest CR when compared to other carriageway widths, while one lane carriageway sections on 2+1 roads were the safest. Road surface results showed that both wheel rut depth and road roughness have negative impacts on traffic safety.

Identifying Critical Road Geometry Parameters Affecting Crash Rate and Crash Type

PubMed Central

Othman, Sarbaz; Thomson, Robert; Lannér, Gunnar

2009-01-01

The objective of this traffic safety investigation was to find critical road parameters affecting crash rate (CR). The study was based on crash and road maintenance data from Western Sweden. More than 3000 crashes, reported from 2000 to 2005 on median-separated roads, were collected and combined with road geometric and surface data. The statistical analysis showed variations in CR when road elements changed confirming that road characteristics affect CR. The findings indicated that large radii right-turn curves were more dangerous than left curves, in particular, during lane changing manoeuvres. However sharper curves are more dangerous in both left and right curves. Moreover, motorway carriageways with no or limited shoulders have the highest CR when compared to other carriageway widths, while one lane carriageway sections on 2+1 roads were the safest. Road surface results showed that both wheel rut depth and road roughness have negative impacts on traffic safety. PMID:20184841

Assessing the Magnitude of Polycyclic Aromatic Hydrocarbon Loading from Road Surfaces and Its Effect on Algal Productivity

DOT National Transportation Integrated Search

2010-06-01

The hypotheses of the study were that PAHs washing off roads would retard the growth of aquatic life-supporting algae and promote the growth of harmful, toxin-producing algae in estuaries, such as the Chesapeake Bay. Runoff from various road surfaces...

Hybrid metal grid-polymer-carbon nanotube electrodes for high luminance organic light emitting diodes

NASA Astrophysics Data System (ADS)

Sam, F. Laurent M.; Dabera, G. Dinesha M. R.; Lai, Khue T.; Mills, Christopher A.; Rozanski, Lynn J.; Silva, S. Ravi P.

2014-08-01

Organic light emitting diodes (OLEDs) incorporating grid transparent conducting electrodes (TCEs) with wide grid line spacing suffer from an inability to transfer charge carriers across the gaps in the grids to promote light emission in these areas. High luminance OLEDs fabricated using a hybrid TCE composed of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS PH1000) or regioregular poly(3-hexylthiophene)-wrapped semiconducting single-walled carbon nanotubes (rrP3HT-SWCNT) in combination with a nanometre thin gold grid are reported here. OLEDs fabricated using the hybrid gold grid/PH1000 TCE have a luminance of 18 000 cd m-2 at 9 V; the same as the reference indium tin oxide (ITO) OLED. The gold grid/rrP3HT-SWCNT OLEDs have a lower luminance of 8260 cd m-2 at 9 V, which is likely due to a rougher rrP3HT-SWCNT surface. These results demonstrate that the hybrid gold grid/PH1000 TCE is a promising replacement for ITO in future plastic electronics applications including OLEDs and organic photovoltaics. For applications where surface roughness is not critical, e.g. electrochromic devices or discharge of static electricity, the gold grid/rrP3HT-SWCNT hybrid TCE can be employed.

Luminous Efficiency of Hypervelocity Meteoroid Impacts on the Moon Derived from the 2015 Geminid Meteor Shower

NASA Technical Reports Server (NTRS)

Moser, D. E.; Suggs, R. M.; Ehlert, S. R.

2017-01-01

Since early 2006 the Meteoroid Environment Office (MEO) at NASA's Marshall Space Flight Center has routinely monitored the Moon for impact flashes produced by meteoroids striking the lunar surface. Activity from the Geminid meteor shower (EM) was observed in 2015, resulting in the detection of 45 lunar impact flashes (roughly 10% of the NASA dataset), in about 10 hours of observation with peak R magnitudes ranging from 6.5 to 11. A subset of 30 of these flashes, observed 14-15 December, was analyzed in order to determine the luminous efficiency, the ratio of emitted luminous energy to the meteoroid's kinetic energy. The resulting luminous efficiency, found to range between n = 1.8 x 10(exp -4) and 3.3 x 10(exp -3), depending on the assumed mass index and flux, was than applied to calculate the masses of Geminid meteoroids striking the Moon in 2015.

Characterizing heavy metal build-up on urban road surfaces: implication for stormwater reuse.

PubMed

Liu, An; Liu, Liang; Li, Dunzhu; Guan, Yuntao

2015-05-15

Stormwater reuse is increasingly popular in the worldwide. In terms of urban road stormwater, it commonly contains toxic pollutants such as heavy metals, which could undermine the reuse safety. The research study investigated heavy metal build-up characteristics on urban roads in a typical megacity of South China. The research outcomes show the high variability in heavy metal build-up loads among different urban road sites. The degree of traffic congestion and road surface roughness was found to exert a more significant influence on heavy metal build-up rather than traffic volume. Due to relatively higher heavy metal loads, stormwater from roads with more congested traffic conditions or rougher surfaces might be suitable for low-water-quality required activities while the stormwater from by-pass road sections could be appropriate for relatively high-water-quality required purposes since the stormwater could be relatively less polluted. Based on the research outcomes, a decision-making process for heavy metals based urban road stormwater reuse was proposed. The new finding highlights the importance to undertaking a "fit-for-purpose" road stormwater reuse strategy. Additionally, the research results can also contribute to enhancing stormwater reuse safety. Copyright © 2015 Elsevier B.V. All rights reserved.

Morphological differences in coronary arteries following rotational atherectomy versus balloon angioplasty: ultrasound and angioscopic observations

NASA Astrophysics Data System (ADS)

Bass, Theodore A.; Gilmore, Paul S.; White, Christopher J.; Chami, Youssef G.; Kircher, Barbara J.; Conetta, Donald A.

1993-09-01

Percutaneous transluminal coronary rotational atherectomy (PTCRA) is an exciting new device to recannulate obstructed coronary arteries. This device works as a high speed `drill,' selectively cutting hard atherosclerotic plaque while preferentially sparing the softer, less diseased vascular luminal surface. At speeds as high as 200,000 rpm the plaque is pulverized into small particles easily handled by the circulatory system with no untoward clinical sequela. Balloon angioplasty does not remove atherosclerotic plaque. It dilates the vessel by mechanically stretching, compressing and splitting the plaque and vessel lining. We compare morphological and surface luminal characteristics of vessels post PTCRA to vessels post PTCA.

Improved performance of Mg-Y alloy thin film switchable mirrors after coating with a superhydrophobic surface

NASA Astrophysics Data System (ADS)

La, Mao; Zhou, Huaijuan; Li, Ning; Xin, Yunchuan; Sha, Ren; Bao, Shanhu; Jin, Ping

2017-05-01

The magnesium based switchable mirrors can reversibly change their optical properties between the transparent and the reflective state as a result of hydrogenation and dehydrogenation. These films can potentially be applied as new energy-saving windows, by controlling the transmittance of solar radiation through the regulation of their reflective state. In this study, magnesium-yttrium (Mg-Y) alloy thin films were prepared using a DC magnetron sputtering method. However, the luminous transmittance in the transparent state and the switching durability of switchable mirrors are too poor to satisfy practical demands. In order to improve the films switching durability, luminous transmittance and the surface functionalization, polytetrafluoroethylene (PTFE) was coated with thermal vacuum deposition for use as the top layer of Mg-Y/Pd switchable mirrors. The PTFE layer had a porous network structure and exhibited a superhydrophobic surface with a water contact angle of approximately 152°. By characterization, PTFE thin films shows the excellent protection role against the oxidization of Mg, the switching durability of the films were improved 3 times, and also shows the antireflection role the luminous transmission of films was enhanced by 7% through the top covered with PTFE.

Response of Iowa pavements to heavy agricultural loads.

DOT National Transportation Integrated Search

1999-12-01

Iowa's county road system includes several thousands of miles of paved roads which : consist of portland cement concrete (PCC) surfaces, asphalt cement concrete (ACC) surfaces, : and combinations of thin surface treatments such as seal coats and slur...

Injection moulding of plastic parts with laser textured surfaces with optical applications

NASA Astrophysics Data System (ADS)

Pina-Estany, J.; García-Granada, A. A.; Corull-Massana, E.

2018-05-01

The purpose of this work is to manufacture micro and nanotextured surfaces on plastic injection moulds with the aim of replicating them and obtaining plastic parts with optical applications. Different patterns are manufactured with nanosecond and femtosecond lasers in order to obtain three different optical applications: (i) homogeneous light diffusion (ii) 1D light directionality and (iii) 2D light directionality. Induction heating is used in the injections in order to improve the textures degree of replication. The steel mould and the plastic parts are analyzed with a confocal/focus variation microscope and with a surface roughness tester. A mock-up and a luminance camera are used to evaluate the homogeneity and luminance of the homogeneous light diffusion application in comparison with the current industrial solutions.

Phenomenal transparency in achromatic checkerboards.

PubMed

Masin, S C

1999-04-01

The study explored the luminance relations that determine the occurrence of achromatic transparency in phenomenal surfaces on complex backgrounds. Let the luminances of the left and right parts of a transparent surface on a bipartite background and those of the left and right parts of the bipartite background be p and q and m and n, respectively. Metelli proposed that this surface looks transparent when the rule p < q if m < n (or p > q if m > n) is satisfied, and Masin and Fukuda that it looks transparent when the inclusion rule is satisfied, that is, when p epsilon (m, q) or q epsilon (p, n). These rules also apply to achromatic checkerboards formed by one checkerboard enclosed in another checkerboard. This study shows that only the inclusion rule correctly predicted the occurrence of transparency in these checkerboards.

Sediment production from forest road surfaces.

Treesearch

Leslie Reid; T. Dunne

2011-01-01

Erosion on roads is an important source of fine-grained sediment in streams draining logged basins of the Pacific Northwest. Runoff rates and sediment concentrations from 10 road segments subject to a variety of traffic levels were monitored to produce sediment rating curves and unit hydrographs for different use levels and types of surfaces. These relationships are...

Trypanosoma cruzi TcSMUG L-surface Mucins Promote Development and Infectivity in the Triatomine Vector Rhodnius prolixus

PubMed Central

Gonzalez, Marcelo S.; Souza, Marcela S.; Garcia, Eloi S.; Nogueira, Nadir F. S.; Mello, Cícero B.; Cánepa, Gaspar E.; Bertotti, Santiago; Durante, Ignacio M.; Azambuja, Patrícia; Buscaglia, Carlos A.

2013-01-01

Background TcSMUG L products were recently identified as novel mucin-type glycoconjugates restricted to the surface of insect-dwelling epimastigote forms of Trypanosoma cruzi, the etiological agent of Chagas disease. The remarkable conservation of their predicted mature N-terminal region, which is exposed to the extracellular milieu, suggests that TcSMUG L products may be involved in structural and/or functional aspects of the interaction with the insect vector. Methodology and Principal Findings Here, we investigated the putative roles of TcSMUG L mucins in both in vivo development and ex vivo attachment of epimastigotes to the luminal surface of the digestive tract of Rhodnius prolixus. Our results indicate that the exogenous addition of TcSMUG L N-terminal peptide, but not control T. cruzi mucin peptides, to the infected bloodmeal inhibited the development of parasites in R. prolixus in a dose-dependent manner. Pre-incubation of insect midguts with the TcSMUG L peptide impaired the ex vivo attachment of epimastigotes to the luminal surface epithelium, likely by competing out TcSMUG L binding sites on the luminal surface of the posterior midgut, as revealed by fluorescence microscopy. Conclusion and Significance Together, these observations indicate that TcSMUG L mucins are a determinant of both adhesion of T. cruzi epimastigotes to the posterior midgut epithelial cells of the triatomine, and the infection of the insect vector, R. prolixus. PMID:24244781

Evaluation Model for Pavement Surface Distress on 3d Point Clouds from Mobile Mapping System

NASA Astrophysics Data System (ADS)

Aoki, K.; Yamamoto, K.; Shimamura, H.

2012-07-01

This paper proposes a methodology to evaluate the pavement surface distress for maintenance planning of road pavement using 3D point clouds from Mobile Mapping System (MMS). The issue on maintenance planning of road pavement requires scheduled rehabilitation activities for damaged pavement sections to keep high level of services. The importance of this performance-based infrastructure asset management on actual inspection data is globally recognized. Inspection methodology of road pavement surface, a semi-automatic measurement system utilizing inspection vehicles for measuring surface deterioration indexes, such as cracking, rutting and IRI, have already been introduced and capable of continuously archiving the pavement performance data. However, any scheduled inspection using automatic measurement vehicle needs much cost according to the instruments' specification or inspection interval. Therefore, implementation of road maintenance work, especially for the local government, is difficult considering costeffectiveness. Based on this background, in this research, the methodologies for a simplified evaluation for pavement surface and assessment of damaged pavement section are proposed using 3D point clouds data to build urban 3D modelling. The simplified evaluation results of road surface were able to provide useful information for road administrator to find out the pavement section for a detailed examination and for an immediate repair work. In particular, the regularity of enumeration of 3D point clouds was evaluated using Chow-test and F-test model by extracting the section where the structural change of a coordinate value was remarkably achieved. Finally, the validity of the current methodology was investigated by conducting a case study dealing with the actual inspection data of the local roads.

[Characteristics of fugitive dust emission from paved road near construction activities].

PubMed

Tian, Gang; Fan, Shou-Bin; Li, Gang; Qin, Jian-Ping

2007-11-01

Because of the mud/dirt carryout from construction activities, the silt loading of paved road nearby is higher and the fugitive dust emission is stronger. By sampling and laboratory analysis of the road surface dust samples, we obtain the silt loading (mass of material equal to or less than 75 micromaters in physical diameter per unit area of travel surface) of paved roads near construction activities. The result show that silt loading of road near construction activities is higher than "normal road", and silt loading is negatively correlated with length from construction's door. According to AP-42 emission factor model of fugitive dust from roads, the emission factor of influenced road is 2 - 10 times bigger than "normal road", and the amount of fugitive dust emission influenced by one construction activity is "equivalent" to an additional road length of approximately 422 - 3 800 m with the baseline silt loading. Based on the spatial and temporal distribution of construction activities, in 2002 the amount of PM10 emission influenced by construction activities in Beijing city areas account of for 59% of fugitive dust from roads.

A theoretical study for the propagation of rolling noise over a porous road pavement

NASA Astrophysics Data System (ADS)

Keung Lui, Wai; Ming Li, Kai

2004-07-01

A simplified model based on the study of sound diffracted by a sphere is proposed for investigating the propagation of noise in a hornlike geometry between porous road surfaces and rolling tires. The simplified model is verified by comparing its predictions with the published numerical and experimental results of studies on the horn amplification of sound over a road pavement. In a parametric study, a point monopole source is assumed to be localized on the surface of a tire. In the frequency range of interest, a porous road pavement can effectively reduce the level of amplified sound due to the horn effect. It has been shown that an increase in the thickness and porosity of a porous layer, or the use of a double layer of porous road pavement, attenuates the horn amplification of sound. However, a decrease in the flow resistivity of a porous road pavement does little to reduce the horn amplification of sound. It has also been demonstrated that the horn effect over a porous road pavement is less dependent on the angular position of the source on the surface of tires.

The measurement of dry deposition and surface runoff to quantify urban road pollution in Taipei, Taiwan.

PubMed

Wang, Yunn-Jinn; Chen, Chi-Feng; Lin, Jen-Yang

2013-10-16

Pollutants deposited on road surfaces and distributed in the environment are a source of nonpoint pollution. Field data are traditionally hard to collect from roads because of constant traffic. In this study, in cooperation with the traffic administration, the dry deposition on and road runoff from urban roads was measured in Taipei City and New Taipei City, Taiwan. The results showed that the dry deposition is 2.01-5.14 g/m(2) · day and 78-87% of these solids are in the 75-300 µm size range. The heavy metals in the dry deposited particles are mainly Fe, Zn, and Na, with average concentrations of 34,978, 1,519 and 1,502 ppm, respectively. Elevated express roads show the highest heavy metal concentrations. Not only the number of vehicles, but also the speed of the traffic should be considered as factors that influence road pollution, as high speeds may accelerate vehicle wear and deposit more heavy metals on road surfaces. In addition to dry deposition, the runoff and water quality was analyzed every five minutes during the first two hours of storm events to capture the properties of the first flush road runoff. The sample mean concentration (SMC) from three roads demonstrated that the first flush runoff had a high pollution content, notably for suspended solid (SS), chemical oxygen demand (COD), oil and grease, Pb, and Zn. Regular sweeping and onsite water treatment facilities are suggested to minimize the pollution from urban roads.

The Distribution of Road Salt in Private Drinking Water Wells in a Southeastern New York Suburban Township.

PubMed

Kelly, Victoria R; Cunningham, Mary Ann; Curri, Neil; Findlay, Stuart E; Carroll, Sean M

2018-05-01

We used a GIS analysis of sodium and chloride concentrations in private water wells in a southeastern New York township to describe the pattern of distribution of road salt in aquifers tapped for drinking water. The primary source of road salt was sodium chloride, and sodium and chloride concentrations were significantly correlated ( = 0.80, < 0.01). Chloride concentrations in wells increased as the percentage of impervious surface cover (ISC) within a 250-m radius around wells increased ( = 0.87, < 0.01) and declined with increasing distance to the nearest road ( = 0.76, < 0.01). Wells that were located lower in elevation than the nearest road had higher concentrations of chloride than wells that were higher than the nearest road, but this occurred only when the nearest road was >30 m from the wells ( < 0.01). Chloride concentrations were not affected by well depth or adjacent road type (major or minor roads). Surface geology and hydrologic soil class had significant effects ( < 0.01) on chloride concentrations in wells, with porous surface geology types and well-drained soils having higher concentrations; these effects may be confounded by the fact that ISC was more likely to occur on these permeable surface geology and soil types. Hot and cold spot analysis revealed substantial unevenness in chloride concentrations. Results for sodium were similar to those for chloride. Overall, these results indicate that road salt contamination of groundwater is unevenly distributed and is affected by landscape factors that can be used to guide well testing and best management practices of deicing salt distribution. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Rapid road repair vehicle

DOEpatents

Mara, Leo M.

1999-01-01

Disclosed are improvments to a rapid road repair vehicle comprising an improved cleaning device arrangement, two dispensing arrays for filling defects more rapidly and efficiently, an array of pre-heaters to heat the road way surface in order to help the repair material better bond to the repaired surface, a means for detecting, measuring, and computing the number, location and volume of each of the detected surface imperfection, and a computer means schema for controlling the operation of the plurality of vehicle subsystems. The improved vehicle is, therefore, better able to perform its intended function of filling surface imperfections while moving over those surfaces at near normal traffic speeds.

Rubber friction on road surfaces: Experiment and theory for low sliding speeds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lorenz, B.; Persson, B. N. J.; Oh, Y. R.

We study rubber friction for tire tread compounds on asphalt road surfaces. The road surface topographies are measured using a stylus instrument and atomic force microscopy, and the surface roughness power spectra are calculated. The rubber viscoelastic modulus mastercurves are obtained from dynamic mechanical analysis measurements and the large-strain effective modulus is obtained from strain sweep data. The rubber friction is measured at different temperatures and sliding velocities, and is compared to the calculated data obtained using the Persson contact mechanics theory. We conclude that in addition to the viscoelastic deformations of the rubber surface by the road asperities, theremore » is an important contribution to the rubber friction from shear processes in the area of contact. The analysis shows that the latter contribution may arise from rubber molecules (or patches of rubber) undergoing bonding-stretching-debonding cycles as discussed in a classic paper by Schallamach.« less

Optimal proportion of studded tyres in traffic flow to prevent polishing of an icy road.

PubMed

Tuononen, Ari J; Sainio, Panu

2014-04-01

Studded tyres can significantly wear the road surface and increase particle emissions from the road surface, which has a negative impact on air quality in urban areas. However, road wear might have a positive aspect by roughening the road surface and thus preventing polishing. As a consequence, other vehicles than the ones using studded tyres might also benefit from the usage of studded tyres. The impact of the proportion of studded tyres in the traffic flow on the tyre-ice friction coefficient was studied with a fleet of real cars in a closed environment under strict procedural control. The results show that a proportion of 25-50% studded tyres in the traffic flow is enough to prevent ice from developing in a manner that is critically slippery for non-studded winter tyres. It was also observed that the visual appearance of the ice surface does not indicate if the ice has become more slippery or not. Copyright © 2013 Elsevier Ltd. All rights reserved.

Multiresolution texture analysis applied to road surface inspection

NASA Astrophysics Data System (ADS)

Paquis, Stephane; Legeay, Vincent; Konik, Hubert; Charrier, Jean

1999-03-01

Technological advances provide now the opportunity to automate the pavement distress assessment. This paper deals with an approach for achieving an automatic vision system for road surface classification. Road surfaces are composed of aggregates, which have a particular grain size distribution and a mortar matrix. From various physical properties and visual aspects, four road families are generated. We present here a tool using a pyramidal process with the assumption that regions or objects in an image rise up because of their uniform texture. Note that the aim is not to compute another statistical parameter but to include usual criteria in our method. In fact, the road surface classification uses a multiresolution cooccurrence matrix and a hierarchical process through an original intensity pyramid, where a father pixel takes the minimum gray level value of its directly linked children pixels. More precisely, only matrix diagonal is taken into account and analyzed along the pyramidal structure, which allows the classification to be made.

Reflectors with directional-mixed reflection properties for application in luminaries with high-power LED diodes

NASA Astrophysics Data System (ADS)

Zaremba, Krzysztof

2008-06-01

Application of directional-mixed reflectors results in a luminance decrease of the apparent image of light emitting diodes (LEDs), which is advantageous as far as glare reduction is concerned. On the other hand, reflectors have a negative impact on luminous intensity curves of the luminaries. This work analyzes an impact of surfaces with directional-mixed reflection properties in a mirror reflector designed for a luminary equipped with high-power LEDs. We present an algorithm used to determine the shape of the reflector of the surface with small scattering, where the axis twist angle for a parabolic reflector varies in a predefined range and follows a power function.

Three-dimensional segmentation of luminal and adventitial borders in serial intravascular ultrasound images

NASA Technical Reports Server (NTRS)

Shekhar, R.; Cothren, R. M.; Vince, D. G.; Chandra, S.; Thomas, J. D.; Cornhill, J. F.

1999-01-01

Intravascular ultrasound (IVUS) provides exact anatomy of arteries, allowing accurate quantitative analysis. Automated segmentation of IVUS images is a prerequisite for routine quantitative analyses. We present a new three-dimensional (3D) segmentation technique, called active surface segmentation, which detects luminal and adventitial borders in IVUS pullback examinations of coronary arteries. The technique was validated against expert tracings by computing correlation coefficients (range 0.83-0.97) and William's index values (range 0.37-0.66). The technique was statistically accurate, robust to image artifacts, and capable of segmenting a large number of images rapidly. Active surface segmentation enabled geometrically accurate 3D reconstruction and visualization of coronary arteries and volumetric measurements.

Dynamic Eigenvalue Problem of Concrete Slab Road Surface

NASA Astrophysics Data System (ADS)

Pawlak, Urszula; Szczecina, Michał

2017-10-01

The paper presents an analysis of the dynamic eigenvalue problem of concrete slab road surface. A sample concrete slab was modelled using Autodesk Robot Structural Analysis software and calculated with Finite Element Method. The slab was set on a one-parameter elastic subsoil, for which the modulus of elasticity was separately calculated. The eigen frequencies and eigenvectors (as maximal vertical nodal displacements) were presented. On the basis of the results of calculations, some basic recommendations for designers of concrete road surfaces were offered.

Application of Wireless Intelligent Control System for HPS Lamps and LEDs Combined Illumination in Road Tunnel

PubMed Central

Lai, Jinxing; Qiu, Junling; Chen, Jianxun; Wang, Yaqiong; Fan, Haobo

2014-01-01

Because of the particularity of the environment in the tunnel, the rational tunnel illumination system should be developed, so as to optimize the tunnel environment. Considering the high cost of traditional tunnel illumination system with high-pressure sodium (HPS) lamps as well as the effect of a single light source on tunnel entrance, the energy-saving illumination system with HPS lamps and LEDs combined illumination in road tunnel, which could make full use of these two kinds of lamps, was proposed. The wireless intelligent control system based on HPS lamps and LEDs combined illumination and microcontrol unit (MCU) Si1000 wireless communication technology was designed. And the remote monitoring, wireless communication, and PWM dimming module of this system were designed emphatically. Intensity detector and vehicle flow detector can be configured in wireless intelligent control system, which gather the information to the master control unit, and then the information is sent to the monitoring center through the Ethernet. The control strategies are got by the monitoring center according to the calculated results, and the control unit wirelessly sends parameters to lamps, which adjust the luminance of each segment of the tunnel and realize the wireless intelligent control of combined illumination in road tunnel. PMID:25587266

Geometry of illumination, luminance contrast, and gloss perception.

PubMed

Leloup, Frédéric B; Pointer, Michael R; Dutré, Philip; Hanselaer, Peter

2010-09-01

The influence of both the geometry of illumination and luminance contrast on gloss perception has been examined using the method of paired comparison. Six achromatic glass samples having different lightness were illuminated by two light sources. Only one of these light sources was visible in reflection by the observer. By separate adjustment of the intensity of both light sources, the luminance of both the reflected image and the adjacent off-specular surroundings could be individually varied. It was found that visual gloss appraisal did not correlate with instrumentally measured specular gloss; however, psychometric contrast seemed to be a much better correlate. It has become clear that not only the sample surface characteristics determine gloss perception: the illumination geometry could be an even more important factor.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reitan, J.B.; Feren, K.

The luminal surface of mouse bladder urothelium was studied by scanning microscopy 1 year after irradiation with 0, 10 and 20 Gy respectively. The controls that were anaesthetized only displayed surface characteristics indistinguishable from normal urothelium. Irradiation with 10 Gy did not result in marked overall changes in the scanning electron microscopic features of the luminal aspect, but in some areas alterations comparable to the alterations after 20 Gy were observed. After irradiation with 20 Gy focal hyperplastic areas, superficial early ulceration and dedifferentiation of cover cells were seen. The dedifferentiation to featureless cells is probably not associated with increasedmore » proliferation, which in focally hyperplastic areas gives rise to a cobblestone or fuzzy appearance with small superficial cells and with many different surface features. The featureless cells may represent degenerative or agonal changes only, but a preneoplastic nature cannot be ruled out.« less

Simulation of Surface Erosion on a Logging Road in the Jackson Demonstration State Forest

Treesearch

Teresa Ish; David Tomberlin

2007-01-01

In constructing management models for the control of sediment delivery to streams, we have used a simulation model of road surface erosion known as the Watershed Erosion Prediction Project (WEPP) model, developed by the USDA Forest Service. This model predicts discharge, erosion, and sediment delivery at the road segment level, based on a stochastic climate simulator...

Slope-area thresholds of road-induced gully erosion and consequent hillslope-channel interactions

Treesearch

Harry Alexander Katz; J. Michael Daniels; Sandra Ryan-Burkett

2014-01-01

Pikes Peak Highway is a partially paved road between Cascade, Colorado and the summit of Pikes Peak. Significant gully erosion is occurring on the hillslopes due to the concentration of surface runoff, the rearrangement of drainage pathways along the road surface and adjacent drainage ditches, and the high erodibility of weathered Pikes Peak granite that underlies the...

Prediction of surface distress using neural networks

NASA Astrophysics Data System (ADS)

Hamdi, Hadiwardoyo, Sigit P.; Correia, A. Gomes; Pereira, Paulo; Cortez, Paulo

2017-06-01

Road infrastructures contribute to a healthy economy throughout a sustainable distribution of goods and services. A road network requires appropriately programmed maintenance treatments in order to keep roads assets in good condition, providing maximum safety for road users under a cost-effective approach. Surface Distress is the key element to identify road condition and may be generated by many different factors. In this paper, a new approach is aimed to predict Surface Distress Index (SDI) values following a data-driven approach. Later this model will be accordingly applied by using data obtained from the Integrated Road Management System (IRMS) database. Artificial Neural Networks (ANNs) are used to predict SDI index using input variables related to the surface of distress, i.e., crack area and width, pothole, rutting, patching and depression. The achieved results show that ANN is able to predict SDI with high correlation factor (R2 = 0.996%). Moreover, a sensitivity analysis was applied to the ANN model, revealing the influence of the most relevant input parameters for SDI prediction, namely rutting (59.8%), crack width (29.9%) and crack area (5.0%), patching (3.0%), pothole (1.7%) and depression (0.3%).

Color measurement and discrimination

NASA Technical Reports Server (NTRS)

Wandell, B. A.

1985-01-01

Theories of color measurement attempt to provide a quantative means for predicting whether two lights will be discriminable to an average observer. All color measurement theories can be characterized as follows: suppose lights a and b evoke responses from three color channels characterized as vectors, v(a) and v(b); the vector difference v(a) - v(b) corresponds to a set of channel responses that would be generated by some real light, call it *. According to theory a and b will be discriminable when * is detectable. A detailed development and test of the classic color measurement approach are reported. In the absence of a luminance component in the test stimuli, a and b, the theory holds well. In the presence of a luminance component, the theory is clearly false. When a luminance component is present discrimination judgements depend largely on whether the lights being discriminated fall in separate, categorical regions of color space. The results suggest that sensory estimation of surface color uses different methods, and the choice of method depends upon properties of the image. When there is significant luminance variation a categorical method is used, while in the absence of significant luminance variation judgments are continuous and consistant with the measurement approach.

Phenotypically heterogeneous deletion of the ABH antigen from the transformed bladder urothelium. A scanning electron microscope study.

PubMed

De Harven, E; He, S; Hanna, W; Bootsma, G; Connolly, J G

1987-10-01

The deletion of ABH blood group antigens from the luminal surface of the bladder mucosa in cases of well differentiated transitional cell carcinomata, and the formation of pleomorphic microvilli have both been associated with aggressive biological behaviour and invasiveness of the tumors. We have studied cold cup biopsies from 8 normal mucosae and 17 papillary transitional cell carcinomata of the urinary bladder. The aim of our study was to correlate the formation of uniform or pleomorphic microvilli with the extent of deletion of the ABH blood group antigens on the surface of normal and transformed bladder urothelium. Immunogold scanning electron microscopy (SEM) in the backscattered electron (BE) imaging mode was used for this purpose. In the normal urothelium, uniform labeling of the luminal cells was demonstrated. In well differentiated tumors, the superficial cells exhibited uniform microvilli and a heterogeneous expression of the ABH antigens, giving characteristic 'mosaic' patterns of the antigenic labeling across the mucosal surface. These patterns were sharply delimitated at cell junctions when viewed by SEM; these observations were confirmed by transmission electron microscopy. In higher grade tumors, decreased ABH antigen expression, pleomorphic microvilli and/or featureless luminal cells were observed. In the transformed urothelium, the formation of uniform microvilli appeared to precede the loss of ABH antigen in most cases.

Laminar shear stress modulates endothelial luminal surface stiffness in a tissue-specific manner.

PubMed

Merna, Nick; Wong, Andrew K; Barahona, Victor; Llanos, Pierre; Kunar, Balvir; Palikuqi, Brisa; Ginsberg, Michael; Rafii, Shahin; Rabbany, Sina Y

2018-04-17

Endothelial cells form vascular beds in all organs and are exposed to a range of mechanical forces that regulate cellular phenotype. We sought to determine the role of endothelial luminal surface stiffness in tissue-specific mechanotransduction of laminar shear stress in microvascular mouse cells and the role of arachidonic acid in mediating this response. Microvascular mouse endothelial cells were subjected to laminar shear stress at 4 dynes/cm 2 for 12 hours in parallel plate flow chambers that enabled real-time optical microscopy and atomic force microscopy measurements of cell stiffness. Lung endothelial cells aligned parallel to flow, while cardiac endothelial cells did not. This rapid alignment was accompanied by increased cell stiffness. The addition of arachidonic acid to cardiac endothelial cells increased alignment and stiffness in response to shear stress. Inhibition of arachidonic acid in lung endothelial cells and embryonic stem cell-derived endothelial cells prevented cellular alignment and decreased cell stiffness. Our findings suggest that increased endothelial luminal surface stiffness in microvascular cells may facilitate mechanotransduction and alignment in response to laminar shear stress. Furthermore, the arachidonic acid pathway may mediate this tissue-specific process. An improved understanding of this response will aid in the treatment of organ-specific vascular disease. © 2018 John Wiley & Sons Ltd.

Dividing attention between two transparent motion surfaces results in a failure of selective attention

PubMed Central

Ernst, Zachary Raymond; Palmer, John; Boynton, Geoffrey M.

2012-01-01

In object-based attention, it is easier to divide attention between features within a single object than between features across objects. In this study we test the prediction of several capacity models in order to best characterize the cost to dividing attention between objects. Here we studied behavioral performance on a divided attention task in which subjects attended to the motion and luminance of overlapping random dot kinemategrams, specifically red upward moving dots superimposed with green downward moving dots. Subjects were required to detect brief changes (transients) in the motion or luminance within the same surface or across different surfaces. There were two primary results. First, the dual-task deficit was large when attention was divided across two surfaces and near zero when attention was divided within a surface. This is consistent with limited-capacity processing across surfaces and unlimited-capacity processing within a surface—a pattern predicted by established theories of object-based attention. Second and unexpectedly, there was evidence of crosstalk between features: when cued to monitor transients on one surface, response rates were inflated by the presence of a transient on the other surface. Such crosstalk is a failure of selective attention between surfaces. PMID:23149301

Cost, performance, and esthetic impacts of an experimental forest road in Montana

Treesearch

Rulon B. Gardner

1978-01-01

An experimental logging road designed to minimize environmental and esthetic impact was constructed in northwest Montana. The road was single-lane (14-foot finished surface, 3-foot ditch), constructed along the contour. Esthetically, the single-lane experimental road was judged far superior to existing roads on the forest.

Luminous Efficiency of Hypervelocity Meteoroid Impacts on the Moon Derived from the 2006 Geminids, 2007 Lyrids, and 2008 Taurids

NASA Technical Reports Server (NTRS)

Moser, D. E.; Suggs, R. M.; Swift, W. R.; Suggs, R. J.; Cooke, W. J.; Diekmann, A. M.; Koehler, H. M.

2011-01-01

Since early 2006, NASA s Marshall Space Flight Center has been routinely monitoring the Moon for impact flashes produced by meteoroids striking the lunar surface. During this time, several meteor showers have produced multiple impact flashes on the Moon. The 2006 Geminids, 2007 Lyrids, and 2008 Taurids were observed with average rates of 5.5, 1.2, and 1.5 meteors/hr, respectively, for a total of 12 Geminid, 12 Lyrid, and 12 Taurid lunar impacts. These showers produced a sufficient, albeit small sample of impact flashes with which to perform a luminous efficiency analysis similar to that outlined in Bellot Rubio et al. (2000a, b) for the 1999 Leonids. An analysis of the Geminid, Lyrid, and Taurid lunar impacts is carried out herein in order to determine the luminous efficiency in the 400-800 nm wavelength range for each shower. Using the luminous efficiency, the kinetic energies and masses of these lunar impactors can be calculated from the observed flash intensity.

Luminous Efficiency of Hypervelocity Meteoroid Impacts on the Moon Derived from the 2006 Geminids, 2007 Lyrids, and 2008 Taurids

NASA Technical Reports Server (NTRS)

Moser, D. E.; Suggs, R. M.; Swift, W. R.; Suggs, R. J.; Cooke, W. J.; Diekmann, A. M.; Koehler, H. M.

2010-01-01

Since early 2006 the Meteoroid Environment Office (MEO) at NASA s Marshall Space Flight Center has been consistently monitoring the Moon for impact flashes produced by meteoroids striking the lunar surface. During this time, several meteor showers have produced multiple impact flashes on the Moon. The 2006 Geminids, 2007 Lyrids, and 2008 Taurids were observed with average rates of 5.5, 1.2, and 1.5 meteors/hr, respectively, for a total of 12 Geminid, 12 Lyrid, and 12 Taurid lunar impacts. These showers produced a sufficient, albeit small sample of impact flashes with which to perform a luminous efficiency analysis similar to that outlined in Bellot Rubio et al. (2000) for the 1999 Leonids. An analysis of the Geminid, Lyrid, and Taurid lunar impacts is carried out herein in order to determine the luminous efficiency in the 400-800 nm wavelength range for each shower. Using the luminous efficiency, the kinetic energies and masses of these lunar impactors can be calculated.

Effect of non-Newtonian and pulsatile blood flow on mass transport in the human aorta.

PubMed

Liu, Xiao; Fan, Yubo; Deng, Xiaoyan; Zhan, Fan

2011-04-07

To investigate the effects of both non-Newtonian behavior and the pulsation of blood flow on the distributions of luminal surface LDL concentration and oxygen flux along the wall of the human aorta, we numerically compared a non-Newtonian model with the Newtonian one under both steady flow and in vivo pulsatile flow conditions using a human aorta model constructed from MRI images. The results showed that under steady flow conditions, although the shear thinning non-Newtonian nature of blood could elevate wall shear stress (WSS) in most regions of the aorta, especially areas with low WSS, it had little effect on luminal surface LDL concentration (c(w)) in most regions of the aorta. Nevertheless, it could significantly enhance c(w) in areas with high luminal surface LDL concentration through the shear dependent diffusivity of LDLs. For oxygen transport, the shear thinning non-Newtonian nature of blood could slightly reduce oxygen flux in most regions of the aorta, but this effect became much more apparent in areas with already low oxygen flux. The pulsation of blood flow could significantly reduce c(w) and enhance oxygen flux in these disturbed places. In most other regions of the aorta, the oxygen flux was also significantly higher than that for the steady flow simulation. In conclusion, the shear shining non-Newtonian nature of blood has little effect on LDL and oxygen transport in most regions of the aorta, but in the atherogenic-prone areas where luminal surface LDL concentration is high and oxygen flux is low, its effect is apparent. Similar is for the effect of pulsatile flow on the transport of LDLs. But, the pulsation of blood flow can apparently affect oxygen flux in the aorta, especially in areas with low oxygen flux. Copyright © 2011 Elsevier Ltd. All rights reserved.

Experimental study of water fluxes in a residential area: 2. Road infiltration, runoff and evaporation

NASA Astrophysics Data System (ADS)

Ragab, R.; Rosier, P.; Dixon, A.; Bromley, J.; Cooper, J. D.

2003-08-01

Lack of accurate data has led some hydrologists and city planners to assume that urban infiltration is zero and runoff is 100% of the rainfall. These assumptions lead to an over estimation of road runoff volume and an underestimation of direct recharge to groundwater, which is already rising under some UK cities. This study investigates infiltration and runoff processes and quantifies the percentage of rainfall that contributes to storm drainage, and that which infiltrates through different types of road surface. Access tubes were installed for measuring soil water content using a neutron probe in three car parks, a road and a grass site at the Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford. Storm drainage was recorded at the exit of the Thamesmead Estate in Crowmarsh Gifford, just before the drain joins the River Thames at Wallingford. Rainfall and water table depth were also recorded. Weekly measurements of soil moisture content indicated that the top 40 cm layer is not influenced by water-table fluctuations and, therefore, positive changes in soil moisture could be attributed to infiltration of rainfall through the surface. Depending on the nature of the surface, subsurface layers, level of traffic, etc., between 6 and 9% of rainfall was found to infiltrate through the road surfaces studied. The storm drainage generated by road runoff revealed a flow pattern similar to that of the receiving watercourse (River Thames) and increased with the increase of infiltration and soil water content below the road surface. The ratio of runoff to rainfall was 0·7, 0·9 and 0·5 for annual, winter (October-March) and summer (April-September) respectively. As the results of the infiltration indicated that 6 to 9% of annual rainfall infiltrates through the road surface, this means that evaporation represents, 21-24% of annual rainfall, with more evaporation taking place during summer than winter.

A GIS tool to analyze forest road sediment production and stream impacts

Treesearch

Ajay Prasad; David G. Tarboton; Charles H. Luce; Thomas A. Black

2005-01-01

A set of GIS tools to analyze the impacts of forest roads on streams considering sediment production, mass wasting risk, and fish passage barriers, has been developed. Sediment production for each road segment is calculated from slope, length, road surface condition and road-side drain vegetation gathered by a GPS inventory and by overlaying the road path on a Digital...

The Measurement of Dry Deposition and Surface Runoff to Quantify Urban Road Pollution in Taipei, Taiwan

PubMed Central

Wang, Yunn-Jinn; Chen, Chi-Feng; Lin, Jen-Yang

2013-01-01

Pollutants deposited on road surfaces and distributed in the environment are a source of nonpoint pollution. Field data are traditionally hard to collect from roads because of constant traffic. In this study, in cooperation with the traffic administration, the dry deposition on and road runoff from urban roads was measured in Taipei City and New Taipei City, Taiwan. The results showed that the dry deposition is 2.01–5.14 g/m2·day and 78–87% of these solids are in the 75–300 µm size range. The heavy metals in the dry deposited particles are mainly Fe, Zn, and Na, with average concentrations of 34,978, 1,519 and 1,502 ppm, respectively. Elevated express roads show the highest heavy metal concentrations. Not only the number of vehicles, but also the speed of the traffic should be considered as factors that influence road pollution, as high speeds may accelerate vehicle wear and deposit more heavy metals on road surfaces. In addition to dry deposition, the runoff and water quality was analyzed every five minutes during the first two hours of storm events to capture the properties of the first flush road runoff. The sample mean concentration (SMC) from three roads demonstrated that the first flush runoff had a high pollution content, notably for suspended solid (SS), chemical oxygen demand (COD), oil and grease, Pb, and Zn. Regular sweeping and onsite water treatment facilities are suggested to minimize the pollution from urban roads. PMID:24135820

High Resolution Trichromatic Road Surface Scanning with a Line Scan Camera and Light Emitting Diode Lighting for Road-Kill Detection.

PubMed

Lopes, Gil; Ribeiro, A Fernando; Sillero, Neftalí; Gonçalves-Seco, Luís; Silva, Cristiano; Franch, Marc; Trigueiros, Paulo

2016-04-19

This paper presents a road surface scanning system that operates with a trichromatic line scan camera with light emitting diode (LED) lighting achieving road surface resolution under a millimeter. It was part of a project named Roadkills-Intelligent systems for surveying mortality of amphibians in Portuguese roads, sponsored by the Portuguese Science and Technology Foundation. A trailer was developed in order to accommodate the complete system with standalone power generation, computer image capture and recording, controlled lighting to operate day or night without disturbance, incremental encoder with 5000 pulses per revolution attached to one of the trailer wheels, under a meter Global Positioning System (GPS) localization, easy to utilize with any vehicle with a trailer towing system and focused on a complete low cost solution. The paper describes the system architecture of the developed prototype, its calibration procedure, the performed experimentation and some obtained results, along with a discussion and comparison with existing systems. Sustained operating trailer speeds of up to 30 km/h are achievable without loss of quality at 4096 pixels' image width (1 m width of road surface) with 250 µm/pixel resolution. Higher scanning speeds can be achieved by lowering the image resolution (120 km/h with 1 mm/pixel). Computer vision algorithms are under development to operate on the captured images in order to automatically detect road-kills of amphibians.

High Resolution Trichromatic Road Surface Scanning with a Line Scan Camera and Light Emitting Diode Lighting for Road-Kill Detection

PubMed Central

Lopes, Gil; Ribeiro, A. Fernando; Sillero, Neftalí; Gonçalves-Seco, Luís; Silva, Cristiano; Franch, Marc; Trigueiros, Paulo

2016-01-01

This paper presents a road surface scanning system that operates with a trichromatic line scan camera with light emitting diode (LED) lighting achieving road surface resolution under a millimeter. It was part of a project named Roadkills—Intelligent systems for surveying mortality of amphibians in Portuguese roads, sponsored by the Portuguese Science and Technology Foundation. A trailer was developed in order to accommodate the complete system with standalone power generation, computer image capture and recording, controlled lighting to operate day or night without disturbance, incremental encoder with 5000 pulses per revolution attached to one of the trailer wheels, under a meter Global Positioning System (GPS) localization, easy to utilize with any vehicle with a trailer towing system and focused on a complete low cost solution. The paper describes the system architecture of the developed prototype, its calibration procedure, the performed experimentation and some obtained results, along with a discussion and comparison with existing systems. Sustained operating trailer speeds of up to 30 km/h are achievable without loss of quality at 4096 pixels’ image width (1 m width of road surface) with 250 µm/pixel resolution. Higher scanning speeds can be achieved by lowering the image resolution (120 km/h with 1 mm/pixel). Computer vision algorithms are under development to operate on the captured images in order to automatically detect road-kills of amphibians. PMID:27104535

Modelling Urban diffuse pollution in groundwater

NASA Astrophysics Data System (ADS)

Jato, Musa; Smith, Martin; Cundy, Andrew

2017-04-01

Diffuse urban pollution of surface and ground waters is a growing concern in many cities and towns. Traffic-derived pollutants such as salts, heavy metals and polycyclic aromatic hydrocarbons (PAHs) may wash off road surfaces in soluble or particulate forms which later drain through soils and drainage systems into surface waters and groundwater. In Brighton, about 90% of drinking water supply comes from groundwater (derived from the Brighton Chalk block). In common with many groundwater sources the Chalk aquifer has been relatively extensively monitored and assessed for diffuse rural contaminants such as nitrate, but knowledge on the extent of contamination from road run-off is currently lacking. This project examines the transfer of traffic-derived contaminants from the road surface to the Chalk aquifer, via urban drainage systems. A transect of five boreholes have been sampled on a monthly basis and groundwater samples analysed to examine the concentrations of key, mainly road run-off derived, hydrocarbon and heavy metal contaminants in groundwater across the Brighton area. Trace concentrations of heavy metals and phenols have been observed in groundwater. Electrical conductivity changes in groundwater have also been used to assess local changes in ionic strength which may be associated with road-derived contaminants. This has been supplemented by systematic water and sediment sampling from urban gully pots, with further sampling planned from drainage and settlement ponds adjacent to major roads, to examine initial road to drainage system transport of major contaminants.

[Research on evaluation of water quality of Beijing urban stormwater runoff].

PubMed

Hou, Pei-Qiang; Ren, Yu-Fen; Wang, Xiao-Ke; Ouyang, Zhi-Yun; Zhou, Xiao-Ping

2012-01-01

The natural rainwater and stormwater runoff samples from three underlying surfaces (rooftop, campus road and ring road) were sampled and analyzed from July to October, 2010 in Beijing. Eight rainfall events were collected totally and thirteen water quality parameters were measured in each event. Grey relationship analysis and principal component analysis were applied to assess composite water quality and identify the main pollution sources of stormwater runoff. The results show that the composite water quality of ring road runoff is mostly polluted, and then is rooftop runoff, campus road runoff and rainwater, respectively. The composite water quality of ring road runoff is inferior to V class of surface water, while rooftop runoff, campus road runoff and rainwater are in II class of surface water. The mean concentration of TN and NH4(+)-N in rainwater and runoff is 5.49-11.75 mg x L(-1) and 2.90-5.67 mg x L(-1), respectively, indicating that rainwater and runoff are polluted by nitrogen (N). Two potential pollution sources are identified in ring road runoff: (1) P, SS and organic pollutant are possibly related to debris which is from vehicle tyre and material of ring road; (2) N and dissolved metal have relations with automobile exhaust emissions and bulk deposition.

Identification and interpretation of tectonic features from Skylab imagery. [Mojave Desert and San Bernardino Mountains, California

NASA Technical Reports Server (NTRS)

Abdel-Gawad, M. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Surface indications of recent faulting are generally observed in EREP S190B photographs. Comparison of secondary roads (asphalt and dirt) registered in EREP and U-2 photographs together with field measurements shows that dirt and asphalt roads about seven meters wide can be detected in EREP S190B photographs where sufficient contrast exists between the tone of the road surface and surrounding terrain. In low contrast cases, roads more than ten meters wide could not be detected.

30 CFR 761.14 - Procedures for relocating or closing a public road or waiving the prohibition on surface coal...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Procedures for relocating or closing a public road or waiving the prohibition on surface coal mining operations within the buffer zone of a public... operations within the buffer zone of a public road. (a) This section does not apply to: (1) Lands for which a...

30 CFR 761.14 - Procedures for relocating or closing a public road or waiving the prohibition on surface coal...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Procedures for relocating or closing a public road or waiving the prohibition on surface coal mining operations within the buffer zone of a public... operations within the buffer zone of a public road. (a) This section does not apply to: (1) Lands for which a...

30 CFR 761.14 - Procedures for relocating or closing a public road or waiving the prohibition on surface coal...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Procedures for relocating or closing a public road or waiving the prohibition on surface coal mining operations within the buffer zone of a public... operations within the buffer zone of a public road. (a) This section does not apply to: (1) Lands for which a...

30 CFR 761.14 - Procedures for relocating or closing a public road or waiving the prohibition on surface coal...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Procedures for relocating or closing a public road or waiving the prohibition on surface coal mining operations within the buffer zone of a public... operations within the buffer zone of a public road. (a) This section does not apply to: (1) Lands for which a...

Understanding road surface pollutant wash-off and underlying physical processes using simulated rainfall.

PubMed

Egodawatta, Prasanna; Goonetilleke, Ashantha

2008-01-01

Pollutant wash-off is one of the key pollutant processes that detailed knowledge is required in order to develop successful treatment design strategies for urban stormwater. Unfortunately, current knowledge relating to pollutant wash-off is limited. This paper presents the outcomes of a detailed investigation into pollutant wash-off on residential road surfaces. The investigations consisted of research methodologies formulated to overcome the physical constraints due to the heterogeneity of urban paved surfaces and the dependency on naturally occurring rainfall. This entailed the use of small road surface plots and artificially simulated rainfall. Road surfaces were selected due to its critical importance as an urban stormwater pollutant source. The study results showed that the influence of initially available pollutants on the wash-off process was limited. Furthermore, pollutant wash-off from road surfaces can be replicated using an exponential equation. However, the typical version of the exponential wash-off equation needs to be modified by introducing a non dimensional factor referred to as 'capacity factor' CF. Three rainfall intensity ranges were identified where the variation of CF can be defined. Furthermore, it was found that particulate density rather than size is the critical parameter that influences the process of pollutant wash-off. (c) IWA Publishing 2008.

Use of oil shale ash in road construction: results of follow-up environmental monitoring.

PubMed

Reinik, Janek; Irha, Natalya; Koroljova, Arina; Meriste, Tõnis

2018-01-05

Oil shale ash (OSA) was used for road construction in a pristine swamp area in East-Estonia during 2013-2014. OSA was used as a binder both in mass stabilization of soft peat soil and in the upper layer. Use of OSA in civil engineering always raises questions about the environmental safety of such activities. Post-construction environmental monitoring of the pilot section was carried out in 2014 and 2015. The monitoring program involved surface water and soil sampling campaigns. Samples were analyzed for selected constituents and parameters of environmental concern. The paper gives data for assessing the environmental impact and evaluation of potential risks associated with construction of roads using OSA. Leaching of hazardous compounds from the pilot section to surrounding aqueous environment was not observed during the monitoring program. Still, the road construction affected the concentration of sulfates in surrounding surface water. Also, the water-soluble content of barium in surface water correlated significantly with the concentrations of chloride and sulfate ion and electric conductivity of the surface water. Therefore, it is recommended to monitor the electric conductivity, concentrations of sulfates, chlorides, and barium in nearby surface water when OSA is used in road construction.

Road icing forecasting and detecting system

NASA Astrophysics Data System (ADS)

Xu, Hongke; Zheng, Jinnan; Li, Peiqi; Wang, Qiucai

2017-05-01

Regard for the facts that the low accuracy and low real-time of the artificial observation to determine the road icing condition, and it is difficult to forecast icing situation, according to the main factors influencing the road-icing, and the electrical characteristics reflected by the pavement ice layer, this paper presents an innovative system, that is, ice-forecasting of the highway's dangerous section. The system bases on road surface water salinity measurements and pavement temperature measurement to calculate the freezing point of water and temperature change trend, and then predicts the occurrence time of road icing; using capacitance measurements to verdict the road surface is frozen or not; This paper expounds the method of using single chip microcomputer as the core of the control system and described the business process of the system.

Low-cost rural surface alternatives : tech transfer summary.

DOT National Transportation Integrated Search

2013-12-01

Freezing-thawing action induces physical changes to granular surface : roads that can negatively impact public users, reduce emergency : responder access/time, and result in maintenance costs for secondary : road departments. Stabilization can help r...

Reshaping Light-Emitting Diodes To Increase External Efficiency

NASA Technical Reports Server (NTRS)

Rogowski, Robert; Egalon, Claudio

1995-01-01

Light-emitting diodes (LEDs) reshaped, according to proposal, increasing amount of light emitted by decreasing fraction of light trapped via total internal reflection. Results in greater luminous output power for same electrical input power; greater external efficiency. Furthermore, light emitted by reshaped LEDs more nearly collimated (less diffuse). Concept potentially advantageous for conventional red-emitting LEDs. More advantageous for new "blue" LEDs, because luminous outputs and efficiencies of these devices very low. Another advantage, proposed conical shapes achieved relatively easily by chemical etching of semiconductor surfaces.

Luminous Supersoft X-Ray Sources as Progenitors of Type Ia Supernovae

NASA Technical Reports Server (NTRS)

DiStefano, R.

1996-01-01

In some luminous supersoft X-ray sources, hydrogen accretes onto the surface of a white dwarf at rates more-or-less compatible with steady nuclear burning. The white dwarfs in these systems therefore have a good chance to grow in mass. Here we review what is known about the rate of Type la supernovae that may be associated with SSSS. Observable consequences of the conjecture that SSSs can be progenitors of Type Ia supernovae are also discussed.

Infiltration, erosion, and vegetation recovery following road obliteration

Treesearch

R. B. Foltz; H. Rhee; K. A. Yanosek

2007-01-01

Forest roads are obliterated to lower the risks of surface erosion and mass failures. One purpose of the road obliteration is to return the compacted forest roads to productive pre-road conditions, i.e., a forest floor with high infiltration capacity, low interrill erodibility, and high vegetation ground cover. It is important to know how these characteristics recover...

Method and algorithm of automatic estimation of road surface type for variable damping control

NASA Astrophysics Data System (ADS)

Dąbrowski, K.; Ślaski, G.

2016-09-01

In this paper authors presented an idea of road surface estimation (recognition) on a base of suspension dynamic response signals statistical analysis. For preliminary analysis cumulated distribution function (CDF) was used, and some conclusion that various roads have responses values in a different ranges of limits for the same percentage of samples or for the same limits different percentages of samples are located within the range between limit values. That was the base for developed and presented algorithm which was tested using suspension response signals recorded during road test riding over various surfaces. Proposed algorithm can be essential part of adaptive damping control algorithm for a vehicle suspension or adaptive control strategy for suspension damping control.

Using remote sensing data to predict road fill areas and areas affected by fill erosion with planned forest road construction: a case study in Kastamonu Regional Forest Directorate (Turkey).

PubMed

Aricak, Burak

2015-07-01

Forest roads are essential for transport in managed forests, yet road construction causes environmental disturbance, both in the surface area the road covers and in erosion and downslope deposition of road fill material. The factors affecting the deposition distance of eroded road fill are the slope gradient and the density of plant cover. Thus, it is important to take these factors into consideration during road planning to minimize their disturbance. The aim of this study was to use remote sensing and field surveying to predict the locations that would be affected by downslope deposition of eroding road fill and to compile the data into a geographic information system (GIS) database. The construction of 99,500 m of forest roads is proposed for the Kastamonu Regional Forest Directorate in Turkey. Using GeoEye satellite images and a digital elevation model (DEM) for the region, the location and extent of downslope deposition of road fill were determined for the roads as planned. It was found that if the proposed roads were constructed by excavators, the fill material would cover 910,621 m(2) and the affected surface area would be 1,302,740 m(2). Application of the method used here can minimize the adverse effects of forest roads.

An Information Retrieval Approach for Robust Prediction of Road Surface States.

PubMed

Park, Jae-Hyung; Kim, Kwanho

2017-01-28

Recently, due to the increasing importance of reducing severe vehicle accidents on roads (especially on highways), the automatic identification of road surface conditions, and the provisioning of such information to drivers in advance, have recently been gaining significant momentum as a proactive solution to decrease the number of vehicle accidents. In this paper, we firstly propose an information retrieval approach that aims to identify road surface states by combining conventional machine-learning techniques and moving average methods. Specifically, when signal information is received from a radar system, our approach attempts to estimate the current state of the road surface based on the similar instances observed previously based on utilizing a given similarity function. Next, the estimated state is then calibrated by using the recently estimated states to yield both effective and robust prediction results. To validate the performances of the proposed approach, we established a real-world experimental setting on a section of actual highway in South Korea and conducted a comparison with the conventional approaches in terms of accuracy. The experimental results show that the proposed approach successfully outperforms the previously developed methods.

An Information Retrieval Approach for Robust Prediction of Road Surface States

PubMed Central

Park, Jae-Hyung; Kim, Kwanho

2017-01-01

Recently, due to the increasing importance of reducing severe vehicle accidents on roads (especially on highways), the automatic identification of road surface conditions, and the provisioning of such information to drivers in advance, have recently been gaining significant momentum as a proactive solution to decrease the number of vehicle accidents. In this paper, we firstly propose an information retrieval approach that aims to identify road surface states by combining conventional machine-learning techniques and moving average methods. Specifically, when signal information is received from a radar system, our approach attempts to estimate the current state of the road surface based on the similar instances observed previously based on utilizing a given similarity function. Next, the estimated state is then calibrated by using the recently estimated states to yield both effective and robust prediction results. To validate the performances of the proposed approach, we established a real-world experimental setting on a section of actual highway in South Korea and conducted a comparison with the conventional approaches in terms of accuracy. The experimental results show that the proposed approach successfully outperforms the previously developed methods. PMID:28134859

Measurement Marker Recognition In A Time Sequence Of Infrared Images For Biomedical Applications

NASA Astrophysics Data System (ADS)

Fiorini, A. R.; Fumero, R.; Marchesi, R.

1986-03-01

In thermographic measurements, quantitative surface temperature evaluation is often uncertain. The main reason is in the lack of available reference points in transient conditions. Reflective markers were used for automatic marker recognition and pixel coordinate computations. An algorithm selects marker icons to match marker references where particular luminance conditions are satisfied. Automatic marker recognition allows luminance compensation and temperature calibration of recorded infrared images. A biomedical application is presented: the dynamic behaviour of the surface temperature distributions is investigated in order to study the performance of two different pumping systems for extracorporeal circulation. Sequences of images are compared and results are discussed. Finally, the algorithm allows to monitor the experimental environment and to alert for the presence of unusual experimental conditions.

Asphalt surface treatment practice in southeastern United States.

DOT National Transportation Integrated Search

2014-07-01

It costs less to maintain roads in good condition than in poor condition. Pavement preservation is a set of : activities to extend pavement life, improve safety, and meet road user expectations. Surface treatments are : pavement preservation treatmen...

An empirical study of the nuclear explosion-induced lightning seen on IVY-MIKE

NASA Astrophysics Data System (ADS)

Colvin, J. D.; Mitchell, C. K.; Greig, J. R.; Murphy, D. P.; Pechacek, R. E.; Raleigh, M.

1987-05-01

We report the results of a unique study of the lightninglike phenomena that were seen to accompany the MIKE shot of operation IVY on October 31 1952. MIKE was a thermonuclear surface burst yielding 10.4 MT, which took place on Enewetak Atoll. During the period of approximately 10 ms after detonation, five discrete luminous channels were seen to start from the ground or sea surface at a distance of approximately 1 km from the burst point and to grow up into the clouds. We have reexamined the original photographic records of IVY-MIKE, obtaining effective brightnesses (optical powers per unit length) for the luminous channels at different altitudes as functions of time. The absolute calibration for the MIKE records was deduced by comparison with the photographic records of other events of that era, laboratory measurements of film sensitivity, and use of atmospheric transmission data taken just prior to the MIKE event. Errors in this analysis lead to an uncertainty of a factor of ˜2 in the brightnesses of the luminous channels. In the laboratory we have used laser-guided electric discharges to create long (100 cm), arclike plasma channels to simulate the observed luminous channels and to allow determination of an empirical relation between the brightness of the channel and the electric current flowing in the channel. These laboratory discharges had peak currents up to 100 kA and periods of ˜2 ms. Spectroscopic analysis showed that the luminous channels consisted primarily of normal air plasma with typical ground-level contaminants. Photographic studies showed that these long-duration discharges are unstable to the m = 1 magnetohydrodynamic (MHD) instability and become severely distorted in less than 1 ms. By direct comparison of the luminous channels seen at MIKE and the laboratory discharges, we deduce: (1) the peak current in the prominent (brightest) channel at MIKE was between 200 and 600 kA. Here the most likely value of the peak current was 250±50 kA, but potential systematic errors in the film calibration and the comparison of MIKE and laboratory data make higher currents possible. (2) The rapid decline in the brightness of the luminous channels seen at MIKE is caused by a combination of the effects of the MHD instability, which eventually leads to a broadening of the current-carrying channel, and channel cooling by turbulent convective mixing.

30 CFR 816.150 - Roads: general.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... (e) Maintenance. (1) A road shall be maintained to meet the performance standards of this part and... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Roads: general. 816.150 Section 816.150 Mineral... PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS-SURFACE MINING ACTIVITIES § 816.150 Roads...

Efficient conceptual design for LED-based pixel light vehicle headlamps

NASA Astrophysics Data System (ADS)

Held, Marcel Philipp; Lachmayer, Roland

2017-12-01

High-resolution vehicle headlamps represent a future-oriented technology that can be used to increase traffic safety and driving comfort. As a further development to the current Matrix Beam headlamps, LED-based pixel light systems enable ideal lighting functions (e.g. projection of navigation information onto the road) to be activated in any given driving scenario. Moreover, compared to other light-modulating elements such as DMDs and LCDs, instantaneous LED on-off toggling provides a decisive advantage in efficiency. To generate highly individualized light distributions for automotive applications, a number of approaches using an LED array may be pursued. One approach is to vary the LED density in the array so as to output the desired light distribution. Another notable approach makes use of an equidistant arrangement of the individual LEDs together with distortion optics to formulate the desired light distribution. The optical system adjusts the light distribution in a manner that improves resolution and increases luminous intensity of the desired area. An efficient setup for pixel generation calls for one lens per LED. Taking into consideration the limited space requirements of the system, this implies that the luminous flux, efficiency and resolution image parameters are primarily controlled by the lens dimensions. In this paper a concept for an equidistant LED array arrangement utilizing distortion optics is presented. The paper is divided into two parts. The first part discusses the influence of lens geometry on the system efficiency whereas the second part investigates the correlation between resolution and luminous flux based on the lens dimensions.

30 CFR 56.9300 - Berms or guardrails.

Code of Federal Regulations, 2010 CFR

2010-07-01

... service or maintenance vehicles, berms or guardrails are not required when all of the following are met... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

30 CFR 57.9300 - Berms or guardrails.

Code of Federal Regulations, 2010 CFR

2010-07-01

... service or maintenance vehicles, berms or guardrails are not required when all of the following are met... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

30 CFR 56.9300 - Berms or guardrails.

Code of Federal Regulations, 2014 CFR

2014-07-01

...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

30 CFR 56.9300 - Berms or guardrails.

Code of Federal Regulations, 2013 CFR

2013-07-01

...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

30 CFR 57.9300 - Berms or guardrails.

Code of Federal Regulations, 2013 CFR

2013-07-01

...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

30 CFR 56.9300 - Berms or guardrails.

Code of Federal Regulations, 2012 CFR

2012-07-01

...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

30 CFR 57.9300 - Berms or guardrails.

Code of Federal Regulations, 2011 CFR

2011-07-01

...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

30 CFR 57.9300 - Berms or guardrails.

Code of Federal Regulations, 2012 CFR

2012-07-01

...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

30 CFR 57.9300 - Berms or guardrails.

Code of Federal Regulations, 2014 CFR

2014-07-01

...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

30 CFR 56.9300 - Berms or guardrails.

Code of Federal Regulations, 2011 CFR

2011-07-01

...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

Evaluation of a laser road surface tester.

DOT National Transportation Integrated Search

1995-01-01

The purpose of this study was to evaluate the accuracy and usefulness of pavement distress data derived from a laser road surface tester (RST) operating on Virginia's interstate highway system. The evaluation was conducted by comparing rut depth, rou...

Binocular stereo matching method based on structure tensor

NASA Astrophysics Data System (ADS)

Song, Xiaowei; Yang, Manyi; Fan, Yubo; Yang, Lei

2016-10-01

In a binocular visual system, to recover the three-dimensional information of the object, the most important step is to acquire matching points. Structure tensor is the vector representation of each point in its local neighborhood. Therefore, structure tensor performs well in region detection of local structure, and it is very suitable for detecting specific graphics such as pedestrians, cars and road signs in the image. In this paper, the structure tensor is combined with the luminance information to form the extended structure tensor. The directional derivatives of luminance in x and y directions are calculated, so that the local structure of the image is more prominent. Meanwhile, the Euclidean distance between the eigenvectors of key points is used as the similarity determination metric of key points in the two images. By matching, the coordinates of the matching points in the detected target are precisely acquired. In this paper, experiments were performed on the captured left and right images. After the binocular calibration, image matching was done to acquire the matching points, and then the target depth was calculated according to these matching points. By comparison, it is proved that the structure tensor can accurately acquire the matching points in binocular stereo matching.

Thermal mapping as a valuable tool for road weather forecast and winter road maintenance: an example from the Italian Alps

NASA Astrophysics Data System (ADS)

Todeschini, Ilaria; Di Napoli, Claudia; Pretto, Ilaria; Merler, Giacomo; Cavaliere, Roberto; Apolloni, Roberto; Antonacci, Gianluca; Piazza, Andrea; Benedetti, Guido

2016-08-01

During the winter period ice is likely to form on roads, making pavement surfaces slippery and increasing accident risk. Road surface temperature (RST) is one of the most important parameters in ice formation. The LIFE+ "CLEANROADS" project aims to forecast RSTs in advance in order to support road maintenance services in the timely and effective preparation of preventive anti-icing measures. This support is provided through a novel MDSS (Maintenance Decision Support System). The final goal of the project is to quantitatively demonstrate that the implemented MDSS is capable to minimize the consumption of chemical anti-icing reagents (e.g. sodium chloride) and the associated environmental (water and air) impact while maintaining the current high levels of road safety. In the CLEAN-ROADS system RSTs have been forecast by applying the numerical model METRo (Model of the Environment and Temperature of Roads) to a network of RWIS (Road Weather Information System) stations installed on a test route in the Adige Valley (Italy). This forecast is however local and does not take into account typical peculiarities along road network, such as the presence of road sections that are particularly prone to ice formation. Thermal mapping, i.e. the acquisition of mobile RST measurements through infrared thermometry, permits to (i) identify and map those sections, and (ii) extend the forecast from a RWIS station to adjacent areas. The processing of thermal mapping signals is however challenging because of random variations in the road surface emissivity. To overcome this we have acquired several thermal mapping traces along the test route during winter seasons 2014-2015 and 2015-2016. We have then defined a "characteristic" thermal fingerprint as a function of all its historical thermal mapping signals, and used it to spatialize local METRo forecasts. Preliminary results suggest the high potential of such a technique for winter road applications.

Predicting the emissive power of hydrocarbon pool fires.

PubMed

Muñoz, Miguel; Planas, Eulàlia; Ferrero, Fabio; Casal, Joaquim

2007-06-18

The emissive power (E) of a flame depends on the size of the fire and the type of fuel. In fact, it changes significantly over the flame surface: the zones of luminous flame have high emittance, while those covered by smoke have low E values. The emissive power of each zone (that is, the luminous or clear flame and the non-luminous or smoky flame) and the portion of total flame area they occupy must be assessed when a two-zone model is used. In this study, data obtained from an experimental set-up were used to estimate the emissive power of fires and its behaviour as a function of pool size. The experiments were performed using gasoline and diesel oil as fuel. Five concentric circular pools (1.5, 3, 4, 5 and 6m in diameter) were used. Appropriate instruments were employed to determine the main features of the fires. By superimposing IR and VHS images it was possible to accurately identify the luminous and non-luminous zones of the fire. Mathematical expressions were obtained that give a more accurate prediction of E(lum), E(soot) and the average emissive power of a fire as a function of its luminous and smoky zones. These expressions can be used in a two-zone model to obtain a better prediction of the thermal radiation. The value of the radiative fraction was determined from the thermal flux measured with radiometers. An expression is also proposed for estimating the radiative fraction.

Laser Diagnostic Analyses of Sooting Flames.

DTIC Science & Technology

1984-11-29

flame front as expected. However the fuel flame length is considerably shorter than the luminous height, and the flame surface must cross the soot surface...very useful in understanding this behaviour and the fact that the fuel flame length increases only slightly on addition of diluent--while the visible

Braking distance algorithm for autonomous cars using road surface recognition

NASA Astrophysics Data System (ADS)

Kavitha, C.; Ashok, B.; Nanthagopal, K.; Desai, Rohan; Rastogi, Nisha; Shetty, Siddhanth

2017-11-01

India is yet to accept semi/fully - autonomous cars and one of the reasons, was loss of control on bad roads. For a better handling on these roads we require advanced braking and that can be done by adapting electronics into the conventional type of braking. In Recent years, the automation in braking system led us to various benefits like traction control system, anti-lock braking system etc. This research work describes and experiments the method for recognizing road surface profile and calculating braking distance. An ultra-sonic surface recognition sensor, mounted underneath the car will send a high frequency wave on to the road surface, which is received by a receiver with in the sensor, it calculates the time taken for the wave to rebound and thus calculates the distance from the point where sensor is mounted. A displacement graph will be plotted based on the output of the sensor. A relationship can be derived between the displacement plot and roughness index through which the friction coefficient can be derived in Matlab for continuous calculation throughout the distance travelled. Since it is a non-contact type of profiling, it is non-destructive. The friction coefficient values received in real-time is used to calculate optimum braking distance. This system, when installed on normal cars can also be used to create a database of road surfaces, especially in cities, which can be shared with other cars. This will help in navigation as well as making the cars more efficient.

Detection of Road Surface States from Tire Noise Using Neural Network Analysis

NASA Astrophysics Data System (ADS)

Kongrattanaprasert, Wuttiwat; Nomura, Hideyuki; Kamakura, Tomoo; Ueda, Koji

This report proposes a new processing method for automatically detecting the states of road surfaces from tire noises of passing vehicles. In addition to multiple indicators of the signal features in the frequency domain, we propose a few feature indicators in the time domain to successfully classify the road states into four categories: snowy, slushy, wet, and dry states. The method is based on artificial neural networks. The proposed classification is carried out in multiple neural networks using learning vector quantization. The outcomes of the networks are then integrated by the voting decision-making scheme. Experimental results obtained from recorded signals for ten days in the snowy season demonstrated that an accuracy of approximately 90% can be attained for predicting road surface states using only tire noise data.

Distributed road assessment system

DOEpatents

Beer, N. Reginald; Paglieroni, David W

2014-03-25

A system that detects damage on or below the surface of a paved structure or pavement is provided. A distributed road assessment system includes road assessment pods and a road assessment server. Each road assessment pod includes a ground-penetrating radar antenna array and a detection system that detects road damage from the return signals as the vehicle on which the pod is mounted travels down a road. Each road assessment pod transmits to the road assessment server occurrence information describing each occurrence of road damage that is newly detected on a current scan of a road. The road assessment server maintains a road damage database of occurrence information describing the previously detected occurrences of road damage. After the road assessment server receives occurrence information for newly detected occurrences of road damage for a portion of a road, the road assessment server determines which newly detected occurrences correspond to which previously detected occurrences of road damage.

Seasonal and geographic distribution of luminous bacteria in the eastern mediterranean sea and the gulf of elat.

PubMed

Yetinson, T; Shilo, M

1979-06-01

Luminous bacteria in the Mediterranean Sea and the Gulf of Aqaba-Elat have different distribution patterns. In the Mediterranean Sea, Beneckea harveyi is present all year round, with different subtypes alternating in summer and winter; Photobacterium fischeri was only present during the winter. In the Gulf of Elat, P. leiognathi is present throughout the water column in similar densities during the entire year. This constancy in distribution is presumably due to the near-constancy in water temperature. In summer, Photobacterium leiognathi is replaced by B. harveyi in coastal surface waters. In the hypersaline Bardawil lagoon, only B. harveyi types are present. P. fischeri, a major component of the Mediterranean Sea winter communities, is absent from the lagoon. Luminous Beneckea strains show a great diversity in properties, e.g. temperature range for growth, sensitivity to infection by phages, sensitivity to attack by Bdellovibrio strains, and differences in tolerance to high-salinity shock. Therefore, subdivision of the taxonomic cluster of B. harveyi into subtypes is indicated. The composition of the luminous bacteria communities may serve as indicators of different marine water bodies. The symbiotic luminous bacteria of the light organ of the common Gulf of Elat fish, Photoblepharon palbebratus steinitzi, is different from any of the types described.

Seasonal and Geographic Distribution of Luminous Bacteria in the Eastern Mediterranean Sea and the Gulf of Elat

PubMed Central

Yetinson, T.; Shilo, M.

1979-01-01

Luminous bacteria in the Mediterranean Sea and the Gulf of Aqaba-Elat have different distribution patterns. In the Mediterranean Sea, Beneckea harveyi is present all year round, with different subtypes alternating in summer and winter; Photobacterium fischeri was only present during the winter. In the Gulf of Elat, P. leiognathi is present throughout the water column in similar densities during the entire year. This constancy in distribution is presumably due to the near-constancy in water temperature. In summer, Photobacterium leiognathi is replaced by B. harveyi in coastal surface waters. In the hypersaline Bardawil lagoon, only B. harveyi types are present. P. fischeri, a major component of the Mediterranean Sea winter communities, is absent from the lagoon. Luminous Beneckea strains show a great diversity in properties, e.g. temperature range for growth, sensitivity to infection by phages, sensitivity to attack by Bdellovibrio strains, and differences in tolerance to high-salinity shock. Therefore, subdivision of the taxonomic cluster of B. harveyi into subtypes is indicated. The composition of the luminous bacteria communities may serve as indicators of different marine water bodies. The symbiotic luminous bacteria of the light organ of the common Gulf of Elat fish, Photoblepharon palbebratus steinitzi, is different from any of the types described. Images PMID:16345404

[Analysis of first flush effect of typical underlying surface runoff in Beijing urban city].

PubMed

Ren, Yu-Fen; Wang, Xiao-Ke; Ouyang, Zhi-Yun; Hou, Pei-Qiang

2013-01-01

Rapid increase of the urban impervious underlying surfaces causes a great increase of urban runoff and the accumulation of pollutants on the roof and road surfaces brings many pollutants into the drainage system with the runoff, and it thus becomes a great threat to the urban water environment. To know the runoff pollution process and to build scientific basis for pollutant control, runoff processes from the roof and road surfaces were monitored and analyzed from 2004 to 2006, and the runoff EMC (Event Mean Concentration) was calculated. It was found that two types of runoff were seriously polluted by COD and TN. The COD and TN of roof runoff exceeded the fifth level of the surface water environmental quality standard (GB 3838-2002) by 3.64 and 4.80 times, respectively, and the COD and TN of road runoff exceeded by 3.73 and 1.07 times, respectively. M (V) curve was used to determine the relation between runoff volume and runoff pollution load. Various degrees of the first flush phenomenon were found for TSS, COD, TN and TP in roof runoff. But this phenomenon occurred only for TSS and TP of the road runoff, and on the whole it was not obvious. Properties of the underlying surfaces, rainfall intensity, and pollutant accumulation are all important factors affecting the roof and road runoff pollutant emission characteristics.

Road Weather Information Systems (RWIS) data integration guidelines

DOT National Transportation Integrated Search

2002-01-01

In an effort to reduce winter road maintenance costs, agencies are using Road Weather : Information Systems (RWIS) to gain more information for application to surface transportation. : RWIS technologies consist of roadside Environmental Sensor Statio...

Erosion and sediment delivery following removal of forest roads

USGS Publications Warehouse

Madej, Mary Ann

2001-01-01

Erosion control treatments were applied to abandoned logging roads in California, with the goal of reducing road-related sediment input to streams and restoring natural hydrologic patterns on the landscape. Treatment of stream crossings involved excavating culverts and associated road fill and reshaping streambanks. A variety of techniques were applied to road benches, which included decompacting the road surface, placing unstable road fill in more stable locations, and re-establishing natural surface drainage patterns. Following treatment and a 12-year recurrence-interval storm, some road reaches and excavated stream crossings showed evidence of mass movement failures, gullying, bank erosion and channel incision. Post-treatment erosion from excavated stream crossings was related to two variables: a surrogate for stream power (drainage area × channel gradient) and the volume of fill excavated from the channel. Post-treatment erosion on road reaches was related to four explanatory variables: method of treatment, hillslope position (upper, mid-slope or lower), date of treatment, and an interaction term (hillslope position × method of treatment). Sediment delivery from treated roads in upper, middle and lower hillslope positions was 10, 135 and 550 m3 of sediment per kilometre of treated roads, respectively. In contrast, inventories of almost 500 km of forest roads in adjacent catchments indicate that untreated roads produced 1500 to 4700 m3 of sediment per kilometre of road length. Erosion from 300 km of treated roads contributed less than 2 per cent of the total sediment load of Redwood Creek during the period 1978 to 1998. Although road removal treatments do not completely eliminate erosion associated with forest roads, they do substantially reduce sediment yields from abandoned logging roads.

65. September 1913 "No. 100. Sprinkling dirt over oil surface ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

65. September 1913 "No. 100. Sprinkling dirt over oil surface of dirt roads preparatory to rolling. This was necessary in order to keep roller from picking up asphaltic oils." - Crater Lake National Park Roads, Klamath Falls, Klamath County, OR

Assessment of roadway surface conditions using vehicle-intrinsic sensors, phase II.

DOT National Transportation Integrated Search

2016-06-28

Using onboard vehicle sensors to provide real-time identification of hazardous road surface conditions, such as the presence of ice, will allow drivers to receive warnings to proceed with caution on compromised road sections, thus reducing crash risk...

View of Antenna #1 (foreground), and Antenna #2 surface doors. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of Antenna #1 (foreground), and Antenna #2 surface doors. Image looking northeast - Titan One Missile Complex 2A, .3 miles west of 129 Road and 1.5 miles north of County Line Road, Aurora, Adams County, CO

View of Launcher #3 surface doors. Launcher #1 in background. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of Launcher #3 surface doors. Launcher #1 in background. Image looking southwest - Titan One Missile Complex 2A, .3 miles west of 129 Road and 1.5 miles north of County Line Road, Aurora, Adams County, CO

The improvement of moisture resistance and thermal stability of Ca 3SiO 4Cl 2:Eu 2+ phosphor coated with SiO 2

NASA Astrophysics Data System (ADS)

Zhuang, Jiaqing; Xia, Zhiguo; Liu, Haikun; Zhang, Zepeng; Liao, Libing

2011-02-01

Green-emitting phosphors Ca3SiO4Cl2:Eu2+ were prepared by the high temperature solid-state method. Sol-gel process was adopted to encapsulate the as-prepared phosphors with tetraethylorthosilicate (TEOS) as silicon coating reagent. Fluorescence spectrometer, scanning electron microscopy (SEM) and powder X-ray diffraction (XRD) patterns were employed to characterize the emission spectra, the surface morphologies and the phase structures, respectively. The chemical stability testing was operated by the method of soaking the phosphors in deionized water and roasting them at different temperatures. The results indicated that the surfaces of the green phosphors were evenly coated by SiO2 and the phase structure of the coated phosphors remained the same as the uncoated samples. The luminance centre of Eu2+ did not shift after surface treatment and the luminance intensity of coated phosphors was lower than that of the uncoated samples. The results demonstrated that the water-resistance stability of the coated phosphor was improved to some degree because the pH value and the luminance intensity variation were both smaller than the uncoated phosphor after steeping within the same time. Moreover, the thermal stability of coated phosphors was enhanced obviously compared to the original samples based on the temperature dependent emission spectra measurement.

Increasing of visibility on the pedestrian crossing by the additional lighting systems

NASA Astrophysics Data System (ADS)

Baleja, Richard; Bos, Petr; Novak, Tomas; Sokansky, Karel; Hanusek, Tomas

2017-09-01

Pedestrian crossings are critical places for road accidents between pedestrians and motor vehicles. For this reason, it is very important to increase attention when the pedestrian crossings are designed and it is necessary to take into account all factors that may contribute to higher safety. Additional lighting systems for pedestrian crossings are one of them and the lighting systems must fulfil the requirements for higher visibility from the point of view of car drivers from both directions. This paper describes the criteria for the suitable additional lighting system on pedestrian crossings. Generally, it means vertical illuminance on the pedestrian crossing from the driver’s view, horizontal illuminance on the crossing and horizontal illuminance both in front of and behind the crossing placed on the road and their acceptable ratios. The article also describes the choice of the colours of the light (correlated colour temperature) and its influence on visibility. As a part of the article, there are case designs of additional lighting systems for pedestrian crossings and measurements from realized additional lighting systems by luxmeters and luminance cameras and their evaluation.

40 CFR 63.4581 - What definitions apply to this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

... adhesives under this subpart. Assembled on-road vehicle coating means any coating operation in which coating... intended for on-road use including, but not limited to, components or surfaces on automobiles and light...). Assembled on-road vehicle coating includes the concurrent coating of parts of the assembled on-road vehicle...

40 CFR 63.4581 - What definitions apply to this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

... adhesives under this subpart. Assembled on-road vehicle coating means any coating operation in which coating... intended for on-road use including, but not limited to, components or surfaces on automobiles and light...). Assembled on-road vehicle coating includes the concurrent coating of parts of the assembled on-road vehicle...

40 CFR 63.4581 - What definitions apply to this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

... adhesives under this subpart. Assembled on-road vehicle coating means any coating operation in which coating... intended for on-road use including, but not limited to, components or surfaces on automobiles and light...). Assembled on-road vehicle coating includes the concurrent coating of parts of the assembled on-road vehicle...

Enhanced road weather forecasting : Clarus regional demonstrations.

DOT National Transportation Integrated Search

2011-01-01

The quality of road weather forecasts has major impacts on users of surface transportation systems and managers of those systems. Improving the quality involves the ability to provide accurate, route-specific road weather information (e.g., timing an...

Evaluation of aggregate sections at Mn/ROAD

DOT National Transportation Integrated Search

2000-06-01

This project focuses on the second construction phase of the Minnesota Road Research facility (Mn/ROAD) and evaluates three typical, locally available, surfacing aggregates along with a rollover section from the initial phase for performance. The pro...

Bicarbonate diffusion through mucus.

PubMed

Livingston, E H; Miller, J; Engel, E

1995-09-01

The mucus layer overlying duodenal epithelium maintains a pH gradient against high luminal acid concentrations. Despite these adverse conditions, epithelial surface pH remains close to neutrality. The exact nature of the gradient-forming barrier remains unknown. The barrier consists of mucus into which HCO3- is secreted. Quantification of the ability of HCO3- to establish and maintain the gradient depends on accurate measurement of this ion's diffusion coefficient through mucus. We describe new experimental and mathematical methods for diffusion measurement and report diffusion coefficients for HCO3- diffusion through saline, 5% mucin solutions, and rat duodenal mucus. The diffusion coefficients were 20.2 +/- 0.10, 3.02 +/- 0.31, and 1.81 +/- 0.12 x 10(-6) cm2/s, respectively. Modeling of the mucobicarbonate layer with this latter value suggests that for conditions of high luminal acid strength the neutralization of acid by HCO3- occurs just above the epithelial surface. Under these conditions the model predicts that fluid convection toward the lumen could be important in maintaining the pH gradient. In support of this hypothesis we were able to demonstrate a net luminal fluid flux of 5 microliters.min-1.cm-2 after perfusion of 0.15 N HCl in the rat duodenum.

Influence of age, speed and duration of monotonous driving task in traffic on the driver's useful visual field.

PubMed

Rogé, Joceline; Pébayle, Thierry; Lambilliotte, Elina; Spitzenstetter, Florence; Giselbrecht, Danièle; Muzet, Alain

2004-10-01

Recent research has shown that the useful visual field deteriorates in simulated car driving when the latter can induce a decrease in the level of activation. The first aim of this study was to verify if the same phenomenon occurs when driving is performed in a simulated road traffic situation. The second aim was to discover if this field also deteriorates as a function of the driver's age and of the vehicle's speed. Nine young drivers (from 22 to 34 years) and nine older drivers (from 46 to 59 years) followed a vehicle in road traffic during two two-hour sessions. The car-following task involved driving at 90 km.h(-1) (speed limit on road in France) in one session and at 130 km.h(-1) (speed limit on motorway in France) in the other session. While following the vehicle, the driver had to detect the changes in colour of a luminous signal located in the central part of his/her visual field and a visual signal that appeared at different eccentricities on the rear lights of the vehicles in the traffic. The analysis of the data indicates that the useful visual field deteriorates with the prolongation of the monotonous simulated driving task, with the driver's age and with the vehicle's speed. The results are discussed in terms of general interference and tunnel vision.

Effectiveness of highway-drainage systems in preventing contamination of ground water by road salt, Route 25, southeastern Massachusetts; description of study area, data collection programs, and methodology

USGS Publications Warehouse

Church, P.E.; Armstrong, D.S.; Granato, G.E.; Stone, V.J.; Smith, K.P.; Provencher, P.L.

1996-01-01

Four test sites along a 7-mile section of Route 25 in southeastern Massachusetts, each representing a specific highway-drainage system, were instrumented to determine the effectiveness of the drainage systems in preventing contamination of ground water by road salt. One of the systems discharges highway runoff onsite through local drainpipes. The other systems use trunkline drainpipes through which runoff from highway surfaces, shoulders, and median strips is diverted and discharged into either a local stream or a coastal waterway. Route 25 was completed and opened to traffic in the summer of 1987. Road salt was first applied to the highway in the winter of 1987-88. The study area is on a thick outwash plain composed primarily of sand and gravel. Water-table depths range from 15 to 60 feet below land surface at the four test sites. Ground-water flow is in a general southerly direction, approximately perpendicular to the highway. Streamflow in the study area is controlled primarily by ground-water discharge. Background concentrations of dissolved chloride, sodium, and calcium-the primary constituents of road salt-are similar in ground water and surface water and range from 5 to 20, 5 to 10, and 1 to 5 milligrams per liter, respectively. Data-collection programs were developed for monitoring the application of road salt to the highway, the quantity of road-salt water entering the ground water, diverted through the highway-drainage systems, and entering a local stream. The Massachusetts Highway Department monitored road salt applied to the highway and reported these data to the U.S. Geological Survey. The U.S. Geological Survey designed and operated the ground-water, highway- drainage, and surface-water data-collection programs. A road-salt budget will be calculated for each test site so that the effectiveness of the different highway-drainage systems in preventing contamination of ground water by road salt can be determined.

Road Weather Management Program : connected vehicle-infrastructure research. Final Report

DOT National Transportation Integrated Search

2016-04-30

This report provides insight into how existing vehicle sensor data (e.g., location, heading, road surface and atmospheric conditions) can be utilized by the CVI environment to support transportation safety through road-weather applications. Of specia...

View of Antenna #1 (foreground), and Antenna #2 surface doors. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of Antenna #1 (foreground), and Antenna #2 surface doors. Orientation Target #2 in background. Image looking northeast - Titan One Missile Complex 2A, .3 miles west of 129 Road and 1.5 miles north of County Line Road, Aurora, Adams County, CO

View of Antenna #2 (foreground), and Antenna #1 surface doors. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of Antenna #2 (foreground), and Antenna #1 surface doors. Orientation Target #1 in background. Image looking northwest - Titan One Missile Complex 2A, .3 miles west of 129 Road and 1.5 miles north of County Line Road, Aurora, Adams County, CO

Plot-, farm-, and watershed-scale effects of coffee cultivation in runoff and sediment production in western Puerto Rico.

PubMed

Ramos-Scharrón, Carlos E; Figueroa-Sánchez, Yasiel

2017-11-01

The combination of a topographically abrupt wet-tropical setting with the high level of soil exposure that typifies many sun-grown coffee farms represents optimal conditions for high erosion rates. Although traditionally considered as a main cause for water resource degradation, limited empirical evidence has existed to document its true contribution. This study relies on plot-scale experimental results conducted in western Puerto Rico to assess the impact of cultivated surfaces and farm access roads on runoff and sediment production from the plot to the farm and watershed scales. Results show that unsurfaced and graveled road surfaces produce one- to two-orders of magnitude more per unit area runoff than cultivated lands. Similarly, erosion rates from unsurfaced roads are about 102 g m -2 per cm of rainfall and these are two-orders of magnitude greater than from actively cultivated surfaces. Mitigation practices such as uncompacting road surfaces by ripping and gravel application reduce onsite erosion rates to 0.6% and 8% of unsurfaced conditions, respectively. At the farm scale, coffee farms are estimated to produce sediment at a rate of 12-18 Mg ha -1 yr -1 , and roads are undoubtedly the dominant sediment source responsible for 59-95% of the total sediment produced. The costs associated to ameliorating erosion problems through road graveling are high. Therefore, a combined approach that treats road erosion onsite with one that traps sediment before it reaches river networks is the viable solution to this problem. Copyright © 2017 Elsevier Ltd. All rights reserved.

Road Asphalt Pavements Analyzed by Airborne Thermal Remote Sensing: Preliminary Results of the Venice Highway.

PubMed

Pascucci, Simone; Bassani, Cristiana; Palombo, Angelo; Poscolieri, Maurizio; Cavalli, Rosa

2008-02-22

This paper describes a fast procedure for evaluating asphalt pavement surface defects using airborne emissivity data. To develop this procedure, we used airborne multispectral emissivity data covering an urban test area close to Venice (Italy).For this study, we first identify and select the roads' asphalt pavements on Multispectral Infrared Visible Imaging Spectrometer (MIVIS) imagery using a segmentation procedure. Next, since in asphalt pavements the surface defects are strictly related to the decrease of oily components that cause an increase of the abundance of surfacing limestone, the diagnostic absorption emissivity peak at 11.2μm of the limestone was used for retrieving from MIVIS emissivity data the areas exhibiting defects on asphalt pavements surface.The results showed that MIVIS emissivity allows establishing a threshold that points out those asphalt road sites on which a check for a maintenance intervention is required. Therefore, this technique can supply local government authorities an efficient, rapid and repeatable road mapping procedure providing the location of the asphalt pavements to be checked.

Estimation of Road Friction Coefficient in Different Road Conditions Based on Vehicle Braking Dynamics

NASA Astrophysics Data System (ADS)

Zhao, You-Qun; Li, Hai-Qing; Lin, Fen; Wang, Jian; Ji, Xue-Wu

2017-07-01

The accurate estimation of road friction coefficient in the active safety control system has become increasingly prominent. Most previous studies on road friction estimation have only used vehicle longitudinal or lateral dynamics and often ignored the load transfer, which tends to cause inaccurate of the actual road friction coefficient. A novel method considering load transfer of front and rear axles is proposed to estimate road friction coefficient based on braking dynamic model of two-wheeled vehicle. Sliding mode control technique is used to build the ideal braking torque controller, which control target is to control the actual wheel slip ratio of front and rear wheels tracking the ideal wheel slip ratio. In order to eliminate the chattering problem of the sliding mode controller, integral switching surface is used to design the sliding mode surface. A second order linear extended state observer is designed to observe road friction coefficient based on wheel speed and braking torque of front and rear wheels. The proposed road friction coefficient estimation schemes are evaluated by simulation in ADAMS/Car. The results show that the estimated values can well agree with the actual values in different road conditions. The observer can estimate road friction coefficient exactly in real-time and resist external disturbance. The proposed research provides a novel method to estimate road friction coefficient with strong robustness and more accurate.

Wheel-Based Ice Sensors for Road Vehicles

NASA Technical Reports Server (NTRS)

Arndt, G. Dickey; Fink, Patrick W.; Ngo, Phong H.; Carl, James R.

2011-01-01

Wheel-based sensors for detection of ice on roads and approximate measurement of the thickness of the ice are under development. These sensors could be used to alert drivers to hazardous local icing conditions in real time. In addition, local ice-thickness measurements by these sensors could serve as guidance for the minimum amount of sand and salt required to be dispensed locally onto road surfaces to ensure safety, thereby helping road crews to utilize their total supplies of sand and salt more efficiently. Like some aircraft wing-surface ice sensors described in a number of previous NASA Tech Briefs articles, the wheelbased ice sensors are based, variously, on measurements of changes in capacitance and/or in radio-frequency impedance as affected by ice on surfaces. In the case of ice on road surfaces, the measurable changes in capacitance and/or impedance are attributable to differences among the electric permittivities of air, ice, water, concrete, and soil. In addition, a related phenomenon that can be useful for distinguishing between ice and water is a specific transition in the permittivity of ice at a temperature- dependent frequency. This feature also provides a continuous calibration of the sensor to allow for changing road conditions. Several configurations of wheel-based ice sensors are under consideration. For example, in a simple two-electrode capacitor configuration, one of the electrodes would be a circumferential electrode within a tire, and the ground would be used as the second electrode. Optionally, the steel belts that are already standard parts of many tires could be used as the circumferential electrodes. In another example (see figure), multiple electrodes would be embedded in rubber between the steel belt and the outer tire surface. These electrodes would be excited in alternating polarities at one or more suitable audio or radio frequencies to provide nearly continuous monitoring of the road surface under the tire. In still another example, one or more microwave stripline(s) or coplanar waveguide(s) would be embedded in a tire near its outer surface; in comparison with lower-frequency capacitive devices, a device of this type could be more sensitive.

Using photographic image analysis to assess ground cover: a case study of forest road cutbanks

Treesearch

Kevin C. Bold; Frederica Wood; Pamela J. Edwards; Karl W.J. Williard; Jon E. Schoonover

2010-01-01

Road prisms, including cutbanks, road surfaces, and fillslopes, can be important contributors of sediment to streams in forested watersheds. Following road construction, cutbanks and fillslopes are often seeded, mulched, and sometimes fertilized to limit erosion and sedimentation. Assessing the success of vegetation establishment on cutbanks and fillslopes is a common...

Assessment of dynamic surface leaching of monolithic surface road materials.

PubMed

Paulus, Hélène; Schick, Joachim; Poirier, Jean-Eric

2016-07-01

Construction materials have to satisfy, among others, health and environment requirements. To check the environmental compatibility of road construction materials, release of hazardous substances into water must be assessed. Literature mostly describes the leaching behaviour of recycled aggregates for potential use in base or sub-base layers of roads. But little is known about the release of soluble substances by materials mixed with binders and compacted for intended use on road surface. In the present study, we thus performed a diffusion test with sequential renewal of water during a 64 day period according to CEN/TS 16637-2 specifications, on asphalt concretes and hydraulically bound monoliths, two common surface road materials. It is shown that release of dangerous substances is limited in these hydrodynamic conditions. It was particularly true for asphalt concrete leachates where no metallic trace element, sulphate, chloride or fluoride ion could be quantified. This is because of the low hydraulic conductivity and the low polarity of the petroleum hydrocarbon binder of these specimens. For hydraulically bound materials around 20,000 mg/m(2) of sulphate diffused from the monoliths. It is one order of magnitude higher than chloride diffusion and two orders of magnitude higher than fluoride release. No metallic trace element, except small quantities of copper in the last eluate could be quantified. No adverse effect is to be expected for human and environmental health from the leachates of these compacted surface road construction materials, because all the measured parameters were below EU (Council Directive 98/83/EC) or WHO guidelines for drinking water standards. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study on road surface source pollution controlled by permeable pavement

NASA Astrophysics Data System (ADS)

Zheng, Chaocheng

2018-06-01

The increase of impermeable pavement in urban construction not only increases the runoff of the pavement, but also produces a large number of Non-Point Source Pollution. In the process of controlling road surface runoff by permeable pavement, a large number of particulate matter will be withheld when rainwater is being infiltrated, so as to control the source pollution at the source. In this experiment, we determined the effect of permeable road surface to remove heavy pollutants in the laboratory and discussed the related factors that affect the non-point pollution of permeable pavement, so as to provide a theoretical basis for the application of permeable pavement.

Performance of reclaimed asphalt pavement on unpaved roads.

DOT National Transportation Integrated Search

2013-05-01

As the volume of traffic on unpaved roads in Wyoming increases with increased drilling activities, dust loss and surface distresses will continue to rise. It would make sense to pave some of these roads, but many counties cannot afford these expensiv...

Measurement of Vehicle Tire-to-Road Coefficient of Friction with a Portable Microcomputerized Transducer.

DTIC Science & Technology

1982-08-01

Sliding Rubber and the Load Dependance of Road Tyre Friction," The Physics of Tire Tractio,’. Theory, and Experiment (Hays, D. F., and Brown, A. L...Saturation of Sliding Rubber and the Load Dependance of Road Tyre Friction," The Physics of Tire Traction, Theory, and Expe-iment (Hays, D. F., and...surfaces could be identified and evaluated before accidents happen or runway surfaces could be evaluated to determine if rubber or other contaminant

View of Launcher #3 surface doors. Launcher #1 in background ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of Launcher #3 surface doors. Launcher #1 in background left, Launcher #2 in background right. Image looking west - Titan One Missile Complex 2A, .3 miles west of 129 Road and 1.5 miles north of County Line Road, Aurora, Adams County, CO

Impacts of road construction and removal on the hydrologic and geochemical function of a fen peatland

NASA Astrophysics Data System (ADS)

Wells, C. M.; Petrone, R. M.; Sutherland, G.; Price, J. S.

2015-12-01

Linear disturbances such as roads cover vast swaths of northeastern Alberta, the majority of which are wetlands with shallow and local hydrologic connections. Thus, the effects of road construction on wetland hydrological pathways can have significant implications on water movement within the region, and by extension the productivity of vegetation communities and carbon sequestration. However, little is known about the effect that roads have on wetland hydrology. In 2013, a gravel road built within a fen peatland was reclaimed to evaluate hydrologic impacts post removal. Prior to removal, ground and surface water flow was obstructed leading to surface ponding, and vegetation mortality was observed on the up-gradient (wet) side of the road. Rebounding of the peat column was observed throughout the fen immediately following road removal in 2013 (maximum of 12 cm, mean of 2 cm), with modest but slightly smaller expansion in 2014. For both years, peat rebound was greatest in areas where the road was removed. Peat physical properties contrasted sharply between the reclaimed road (RR) peat and the adjacent, unimpacted peatland (UP). Surface bulk densities (pb, 0-10 cm) ranged from 0.1-0.25 g cm-3 along the RR compared to 0.02-0.07 g cm-3 for the UP and on average, pb for all depths were lower at the RR compared to the UP. Similar spatial patterns were observed for peat porosity. Correspondingly low horizontal saturated hydraulic conductivities (Kh) were observed along the RR compared to the UP, averaging 5.7x10-4 m s-1 and 1.7x10-3 m s-1, respectively. The local flow system across the RR and thus subsurface flow was impeded by almost half (0.4 m d-1) compared to flow observed within the UP (0.8 m d-1), leading to ponding on the upgradient side. A marked change in hydrophysical properties and ground and surface water flow patterns post road removal has implications for plant reestablishment and restoration and will form the basis of further study.

Sources and properties of non-exhaust particulate matter from road traffic: a review.

PubMed

Thorpe, Alistair; Harrison, Roy M

2008-08-01

While emissions control regulation has led to a substantial reduction in exhaust emissions from road traffic, currently non-exhaust emissions from road vehicles are unabated. These include particles from brake wear, tyre wear, road surface abrasion and resuspension in the wake of passing traffic. Quantification of the magnitude of such emissions is problematic both in the laboratory and the field and the latter depends heavily upon a knowledge of the physical and chemical properties of non-exhaust particles. This review looks at each source in turn, reviewing the available information on the source materials and particles derived from them in laboratory studies. In a final section, some of the key publications dealing with measurements in road tunnels and the roadside environment are reviewed. It is concluded that with the exception of brake dust particles which may be identified from their copper (Cu) and antimony (Sb) content, unequivocal identification of particles from other sources is likely to prove extremely difficult, either because of the lack of suitable tracer elements or compounds, or because of the interactions between sources prior to the emission process. Even in the case of brake dust, problems will arise in distinguishing directly emitted particles from those arising from resuspension of deposited brake dust from the road surface, or that derived from entrainment of polluted roadside soils, either directly or as a component of road surface dust.

A comparative study of the grain-size distribution of surface dust and stormwater runoff quality on typical urban roads and roofs in Beijing, China.

PubMed

Shen, Zhenyao; Liu, Jin; Aini, Guzhanuer; Gong, Yongwei

2016-02-01

The deposition of pollutants on impervious surfaces is a serious problem associated with rapid urbanization, which results in non-point-source pollution. Characterizing the build-up and wash-off processes of pollutants in urban catchments is essential for urban planners. In this paper, the spatial variation and particle-size distributions of five heavy metals and two nutrients in surface dust were analyzed, and the runoff water first-flush effect (FF30) and event-mean concentrations (EMCs) of 10 common constituents were characterized. The relationships between runoff variables and stormwater characteristics were examined from three typical urban impervious surfaces in Beijing, China. Dust on road surfaces with smaller grain sizes had higher pollutant concentrations, whereas concentrations of Mn, Zn, Fe, and TP in roof surface dust increased with grain size. Particles with grain sizes of 38-74 and 125-300 μm contributed most to the total pollutant load in roads, while particles with the smallest grain sizes (<38 μm) contributed most on roofs (23.46-41.71 %). Event-mean concentrations (EMCs) and FF30 values for most runoff pollutants tended to be higher on roofs than on roads. The maximum intensity (I max) and the antecedent dry days (ADD) were critical parameters for EMCs in roads, while ADD was the only dominant parameter for EMCs on our studied roof. The rainfall intensity (RI) and maximum intensity (I max) were found to be the parameters with the strongest correlation to the first-flush effect on both roads and roofs. Significant correlations of total suspended solids (TSS) concentration in runoff with grain-size fractions of surface dust indicated that coarser particles (74-300 μm) are most likely to contribute to the solid-phase pollutants, and finer particles (<38 μm) are likely the main source of dissolved pollutants.

Optimal usage of de-icing chemicals when scraping ice.

DOT National Transportation Integrated Search

2003-11-01

One of the challenges that faces the winter maintainer is how much chemical to : apply to the road under given conditions. Insufficient chemical can lead to the road : surface becoming slick, and the road thus becoming unsafe. In all likelihood, addi...

Effects of forest road amelioration techniques on soil bulk density, surface runoff, sediment transport, soil moisture and seedling growth

Treesearch

Randy K. Kolka; Mathew F. Smidt

2004-01-01

Although numerous methods have been used to retire roads, new technologies have evolved that can potentially ameliorate soil damage, lessen ,the generation of nonpoint source pollution and increase tree productivity on forest roads. In this study we investigated the effects of three forest road amelioration techniques, subsoiling, recontouring and traditional...

Measuring water and sediment discharge from a road plot with a settling basin and tipping bucket

Treesearch

Thomas A. Black; Charles H. Luce

2013-01-01

A simple empirical method quantifies water and sediment production from a forest road surface, and is well suited for calibration and validation of road sediment models. To apply this quantitative method, the hydrologic technician installs bordered plots on existing typical road segments and measures coarse sediment production in a settling tank. When a tipping bucket...

Effects of traffic and ditch maintenance on forest road sediment production

Treesearch

Charles H. Luce; Thomas A. Black

2001-01-01

Observations of sediment yield from road segments in the Oregon Coast Range show that either heavy traffic during rainfall or blading the road ditch will increase erosion from forest roads. For the fine soils and high quality aggregate surfacing on the study plots, ditch blading increased sediment yield more than traffic equivalent to 12 log trucks per day. The...

Gradient cuts and extremal edges in relative depth and figure-ground perception.

PubMed

Ghose, Tandra; Palmer, Stephen E

2016-02-01

Extremal edges (EEs) are borders consisting of luminance gradients along the projected edge of a partly self-occluding curved surface (e.g., a cylinder), with equiluminant contours (ELCs) that run approximately parallel to that edge. Gradient cuts (GCs) are similar luminance gradients with ELCs that intersect (are "cut" by) an edge that could be due to occlusion. EEs are strongly biased toward being seen as closer/figural surfaces (Palmer & Ghose, Psychological Science, 19(1), 77-83, 2008). Do GCs produce a complementary bias toward being seen as ground? Experiment 1 shows that, with EEs on the opposite side, GCs produce a ground bias that increases with increasing ELC angles between ELCs and the shared edge. Experiment 2 shows that, with flat surfaces on the opposite side, GCs do not produce a ground bias, suggesting that more than one factor may be operating. We suggest that two partially dissociable factors may operate for curved surfaces-ELC angle and 3-D surface convexity-that reinforce each other in the figural cues of EEs but compete with each other in GCs. Moreover, this figural bias is modulated by the presence of EEs and GCs, as specified by the ELC angle between ELCs and the shared contour.

Nonlinear dynamics in the perceptual grouping of connected surfaces.

PubMed

Hock, Howard S; Schöner, Gregor

2016-09-01

Evidence obtained using the dynamic grouping method has shown that the grouping of an object's connected surfaces has properties characteristic of a nonlinear dynamical system. When a surface's luminance changes, one of its boundaries is perceived moving across the surface. The direction of this dynamic grouping (DG) motion indicates which of two flanking surfaces has been grouped with the changing surface. A quantitative measure of overall grouping strength (affinity) for adjacent surfaces is provided by the frequency of DG motion perception in directions promoted by the grouping variables. It was found that: (1) variables affecting surface grouping for three-surface objects evolve over time, settling at stable levels within a single fixation, (2) how often DG motion is perceived when a surface's luminance is perturbed (changed) depends on the pre-perturbation affinity state of the surface grouping, (3) grouping variables promoting the same surface grouping combine cooperatively and nonlinearly (super-additively) in determining the surface grouping's affinity, (4) different DG motion directions during different trials indicate that surface grouping can be bistable, which implies that inhibitory interactions have stabilized one of two alternative surface groupings, and (5) when alternative surface groupings have identical affinity, stochastic fluctuations can break the symmetry and inhibitory interactions can then stabilize one of the surface groupings, providing affinity levels are not too high (which results in bidirectional DG motion). A surface-grouping network is proposed within which boundaries vary in salience. Low salience or suppressed boundaries instantiate surface grouping, and DG motion results from changes in boundary salience. Copyright © 2015 Elsevier Ltd. All rights reserved.

30 CFR 780.37 - Road systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Road systems. 780.37 Section 780.37 Mineral... MINING AND RECLAMATION OPERATIONS PERMITS AND COAL EXPLORATION SYSTEMS UNDER REGULATORY PROGRAMS SURFACE MINING PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR RECLAMATION AND OPERATION PLAN § 780.37 Road systems...

30 CFR 780.37 - Road systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Road systems. 780.37 Section 780.37 Mineral... MINING AND RECLAMATION OPERATIONS PERMITS AND COAL EXPLORATION SYSTEMS UNDER REGULATORY PROGRAMS SURFACE MINING PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR RECLAMATION AND OPERATION PLAN § 780.37 Road systems...

30 CFR 780.37 - Road systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Road systems. 780.37 Section 780.37 Mineral... MINING AND RECLAMATION OPERATIONS PERMITS AND COAL EXPLORATION SYSTEMS UNDER REGULATORY PROGRAMS SURFACE MINING PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR RECLAMATION AND OPERATION PLAN § 780.37 Road systems...

Development of a method to remove raised-pavement markers (RPMs) from road surfaces : final report.

DOT National Transportation Integrated Search

2012-06-01

The Georgia Department of Transportation (GDOT) uses raised pavement markers (RPMs) widely on roads : throughout the State to increase road safety. Each of the approximate 3 million RPMs in Georgia was placed : manually. Unfortunately, RPMs do not la...

Importance of tread inertia and damping on the tyre/road contact stiffness

NASA Astrophysics Data System (ADS)

Winroth, J.; Andersson, P. B. U.; Kropp, W.

2014-10-01

Predicting tyre/road interaction processes like roughness excitation, stick-slip, stick-snap, wear and traction requires detailed information about the road surface, the tyre dynamics and the local deformation of the tread at the interface. Aspects of inertia and damping when the tread is locally deformed are often neglected in many existing tyre/road interaction models. The objective of this paper is to study how the dynamic features of the tread affect contact forces and contact stiffness during local deformation. This is done by simulating the detailed contact between an elastic layer and a rough road surface using a previously developed numerical time domain contact model. Road roughness on length scales smaller than the discretisation scale is included by the addition of nonlinear contact springs between each pair of contact elements. The dynamic case, with an elastic layer impulse response extending in time, is compared with the case where the corresponding quasi-static response is used. Results highlight the difficulty of estimating a constant contact stiffness as it increases during the indentation process between the elastic layer and the rough road surface. The stiffness-indentation relation additionally depends on how rapidly the contact develops; a faster process gives a stiffer contact. Material properties like loss factor and density also alter the contact development. This work implies that dynamic properties of the local tread deformation may be of importance when simulating contact details during normal tyre/road interaction conditions. There are however indications that the significant effect of damping could approximately be included as an increased stiffness in a quasi-static tread model.

Bobcats ( Lynx rufus) as a Model Organism to Investigate the Effects of Roads on Wide-Ranging Carnivores

NASA Astrophysics Data System (ADS)

Litvaitis, John A.; Reed, Gregory C.; Carroll, Rory P.; Litvaitis, Marian K.; Tash, Jeffrey; Mahard, Tyler; Broman, Derek J. A.; Callahan, Catherine; Ellingwood, Mark

2015-06-01

We are using bobcats ( Lynx rufus) as a model organism to examine how roads affect the abundance, distribution, and genetic structure of a wide-ranging carnivore. First, we compared the distribution of bobcat-vehicle collisions to road density and then estimated collision probabilities for specific landscapes using a moving window with road-specific traffic volume. Next, we obtained incidental observations of bobcats from the public, camera-trap detections, and locations of bobcats equipped with GPS collars to examine habitat selection. These data were used to generate a cost-surface map to investigate potential barrier effects of roads. Finally, we have begun an examination of genetic structure of bobcat populations in relation to major road networks. Distribution of vehicle-killed bobcats was correlated with road density, especially state and interstate highways. Collision models suggested that some regions may function as demographic sinks. Simulated movements in the context of the cost-surface map indicated that some major roads may be barriers. These patterns were supported by the genetic structure of bobcats. The sharpest divisions among genetically distinct demes occurred along natural barriers (mountains and large lakes) and in road-dense regions. In conclusion, our study has demonstrated the utility of using bobcats as a model organism to understand the variety of threats that roads pose to a wide-ranging species. Bobcats may also be useful as one of a group of focal species while developing approaches to maintain existing connectivity or mitigate the negative effects of roads.

Bobcats (Lynx rufus) as a Model Organism to Investigate the Effects of Roads on Wide-Ranging Carnivores.

PubMed

Litvaitis, John A; Reed, Gregory C; Carroll, Rory P; Litvaitis, Marian K; Tash, Jeffrey; Mahard, Tyler; Broman, Derek J A; Callahan, Catherine; Ellingwood, Mark

2015-06-01

We are using bobcats (Lynx rufus) as a model organism to examine how roads affect the abundance, distribution, and genetic structure of a wide-ranging carnivore. First, we compared the distribution of bobcat-vehicle collisions to road density and then estimated collision probabilities for specific landscapes using a moving window with road-specific traffic volume. Next, we obtained incidental observations of bobcats from the public, camera-trap detections, and locations of bobcats equipped with GPS collars to examine habitat selection. These data were used to generate a cost-surface map to investigate potential barrier effects of roads. Finally, we have begun an examination of genetic structure of bobcat populations in relation to major road networks. Distribution of vehicle-killed bobcats was correlated with road density, especially state and interstate highways. Collision models suggested that some regions may function as demographic sinks. Simulated movements in the context of the cost-surface map indicated that some major roads may be barriers. These patterns were supported by the genetic structure of bobcats. The sharpest divisions among genetically distinct demes occurred along natural barriers (mountains and large lakes) and in road-dense regions. In conclusion, our study has demonstrated the utility of using bobcats as a model organism to understand the variety of threats that roads pose to a wide-ranging species. Bobcats may also be useful as one of a group of focal species while developing approaches to maintain existing connectivity or mitigate the negative effects of roads.

Disentangle the Causes of the Road Barrier Effect in Small Mammals through Genetic Patterns.

PubMed

Ascensão, Fernando; Mata, Cristina; Malo, Juan E; Ruiz-Capillas, Pablo; Silva, Catarina; Silva, André P; Santos-Reis, Margarida; Fernandes, Carlos

2016-01-01

Road barrier effect is among the foremost negative impacts of roads on wildlife. Knowledge of the factors responsible for the road barrier effect is crucial to understand and predict species' responses to roads, and to improve mitigation measures in the context of management and conservation. We built a set of hypothesis aiming to infer the most probable cause of road barrier effect (traffic effect or road surface avoidance), while controlling for the potentially confounding effects road width, traffic volume and road age. The wood mouse Apodemus sylvaticus was used as a model species of small and forest-dwelling mammals, which are more likely to be affected by gaps in cover such as those resulting from road construction. We confront genetic patterns from opposite and same roadsides from samples of three highways and used computer simulations to infer migration rates between opposite roadsides. Genetic patterns from 302 samples (ca. 100 per highway) suggest that the highway barrier effect for wood mouse is due to road surface avoidance. However, from the simulations we estimated a migration rate of about 5% between opposite roadsides, indicating that some limited gene flow across highways does occur. To reduce highway impact on population genetic diversity and structure, possible mitigation measures could include retrofitting of culverts and underpasses to increase their attractiveness and facilitate their use by wood mice and other species, and setting aside roadside strips without vegetation removal to facilitate establishment and dispersal of small mammals.

Disentangle the Causes of the Road Barrier Effect in Small Mammals through Genetic Patterns

PubMed Central

Ascensão, Fernando; Mata, Cristina; Malo, Juan E.; Ruiz-Capillas, Pablo; Silva, Catarina; Silva, André P.; Santos-Reis, Margarida; Fernandes, Carlos

2016-01-01

Road barrier effect is among the foremost negative impacts of roads on wildlife. Knowledge of the factors responsible for the road barrier effect is crucial to understand and predict species’ responses to roads, and to improve mitigation measures in the context of management and conservation. We built a set of hypothesis aiming to infer the most probable cause of road barrier effect (traffic effect or road surface avoidance), while controlling for the potentially confounding effects road width, traffic volume and road age. The wood mouse Apodemus sylvaticus was used as a model species of small and forest-dwelling mammals, which are more likely to be affected by gaps in cover such as those resulting from road construction. We confront genetic patterns from opposite and same roadsides from samples of three highways and used computer simulations to infer migration rates between opposite roadsides. Genetic patterns from 302 samples (ca. 100 per highway) suggest that the highway barrier effect for wood mouse is due to road surface avoidance. However, from the simulations we estimated a migration rate of about 5% between opposite roadsides, indicating that some limited gene flow across highways does occur. To reduce highway impact on population genetic diversity and structure, possible mitigation measures could include retrofitting of culverts and underpasses to increase their attractiveness and facilitate their use by wood mice and other species, and setting aside roadside strips without vegetation removal to facilitate establishment and dispersal of small mammals. PMID:26978779

Design Criteria for Aggregate-Surfaced Roads and Airfields

DTIC Science & Technology

1989-04-01

functional failure conditions and their effects are tabulated in Table 4. It indicates that many distress factors may act on the gravel surface to increase...displacements. Table 4 Major Distress Types of Low-Volume Roads Distress Factor Effect on ..... Dusting Safety, environment Surface looseness Safety, roughness...will be less than that assumed as the design objective. Frost Considerations 9. The detrimental effects of frost action in subsurface materials of

Characteristics of tyre dust in polluted air: Studies by single particle mass spectrometry (ATOFMS)

NASA Astrophysics Data System (ADS)

Dall'Osto, Manuel; Beddows, David C. S.; Gietl, Johanna K.; Olatunbosun, Oluremi A.; Yang, Xiaoguang; Harrison, Roy M.

2014-09-01

There is a paucity of quantitative knowledge on the contributions of non-exhaust (abrasion and re-suspension) sources to traffic emissions. Abrasive emissions can be broadly categorised as tyre wear, brake wear and road dust/road surface wear. Current research often considers road dust and tyre dust as externally mixed particles, the former mainly composed of mineral matter and the latter solely composed of mainly organic matter and some trace elements. The aim of this work was to characterise tyre wear from both laboratory and field studies by using Aerosol Time-Of-Flight Mass Spectrometry (ATOFMS). Real-time single particle chemical composition was obtained from a set of rubber tyres rotating on a metal surface. Bimodal particle number size distributions peaking at 35 nm and 85 nm were obtained from SMPS/APS measurements over the range 6-20,000 nm. ATOFMS mass spectra of tyre wear in the particle size range 200-3000 nm diameter show peaks due to exo-sulphur compounds, nitrate, Zn and ions of high molecular weight (m/z > 100) attributed to organic polymers. Two large ATOFMS datasets collected from a number of outdoor studies were examined. The former was constituted of 48 road dust samples collected on the roads of London. The latter consisted of ATOFMS ambient air field studies from Europe, overall composed of more than 2,000,000 single particle mass spectra. The majority (95%) of tyre wear particles present in the road dust samples and atmospheric samples are internally mixed with metals (Li, Na, Ca, Fe, Ti), as well as phosphate. It is concluded that the interaction of tyres with the road surface creates particles internally mixed from two sources: tyre rubber and road surface materials. Measurements of the tyre rubber component alone may underestimate the contribution of tyre wear to concentrations of airborne particulate matter. The results presented are especially relevant for urban aerosol source apportionment and PM2.5 exposure assessment.

Relationships between nocturnal winter road slipperiness, cloud cover and surface temperature

NASA Astrophysics Data System (ADS)

Grimbacher, T.; Schmid, W.

2003-04-01

Ice and Snow are important risks for road traffic. In this study we show several events of slipperiness in Switzerland, mainly caused by rain or snow falling on a frozen surface. Other reasons for slippery conditions are frost or freezing dew in clear nights and nocturnal clearing after precipitation, which goes along with radiative cooling. The main parameters of road weather forecasts are precipitation, cloudiness and surface temperature. Precipitation is well predictable with weather radars and radar nowcasting algorithms. Temperatures are often taken from numerical weather prediction models, but because of changes in cloud cover these model values are inaccurate in terms of predicting the onset of freezing. Cloudiness, especially the advection, formation and dissipation of clouds and their interaction with surface temperatures, is one of the major unsolved problems of road weather forecasts. Cloud cover and the temperature difference between air and surface temperature are important parameters of the radiation balance. In this contribution, we show the relationship between them, proved at several stations all over Switzerland. We found a quadratic correlation coefficient of typically 60% and improved it considering other meteorological parameters like wind speed and surface water. The acquired relationship may vary from one station to another, but we conclude that temperature difference is a signature for nocturnal cloudiness. We investigated nocturnal cloudiness for two cases from winters 2002 and 2003 in the canton of Lucerne in central Switzerland. There, an ultra-dense combination of two networks with together 55 stations within 50x50 km^2 is operated, measuring air and surface temperature, wind and other road weather parameters. With the aid of our equations, temperature differences detected from this network were converted into cloud maps. A comparison between precipitation seen by radar, cloud maps and surface temperatures shows that there are similar structures in all data. Depending on the situation, we also identified additional effects influencing the temperature differences, for instance the advection of could air or the influence of melting heat at or after a snow event. All these findings help to further understand the phenomena, and hence will contribute to a better predictability of winter road slipperiness.

49 CFR 1242.15 - Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 9 2012-10-01 2012-10-01 false Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast, track laying and surfacing, and road property damaged... culverts, ties, rails, other track material, ballast, track laying and surfacing, and road property damaged...

49 CFR 1242.15 - Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 9 2011-10-01 2011-10-01 false Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast, track laying and surfacing, and road property damaged... culverts, ties, rails, other track material, ballast, track laying and surfacing, and road property damaged...

49 CFR 1242.15 - Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 9 2013-10-01 2013-10-01 false Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast, track laying and surfacing, and road property damaged... culverts, ties, rails, other track material, ballast, track laying and surfacing, and road property damaged...

49 CFR 1242.15 - Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 9 2014-10-01 2014-10-01 false Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast, track laying and surfacing, and road property damaged... culverts, ties, rails, other track material, ballast, track laying and surfacing, and road property damaged...

Overview and application of the Continuous-Flow Traffic Time-Integrated Method (CTIM) for determining the influence of road surfaces on traffic noise

DOT National Transportation Integrated Search

2012-08-19

The U.S. Department of Transportation Federal Highway Administration is sponsoring a Technical Working Group (TWG) to develop guidance for measuring the influence of road surfaces on tire-pavement noise, vehicle noise, and traffic noise in the U.S. T...

Surface and ground water quality in a restored urban stream affected by road salts

EPA Science Inventory

In 2001 research began in Minebank Run, MD to examine the impact of restoration on water quality. Our research area was to determine if road salts in the surface and ground waters are detrimental to the stream channel restoration. The upstream reach (UP), above the Baltimore I-...

7 CFR 1980.313 - Site and building requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... direct access from a street, road, or driveway. Streets and roads must be hard surface or all-weather surface. (c) Water and water/waste disposal system. A nonfarm tract on which a loan is to be made must have an adequate water and water/waste disposal system and other related facilities. Water and water...

7 CFR 1980.313 - Site and building requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... direct access from a street, road, or driveway. Streets and roads must be hard surface or all-weather surface. (c) Water and water/waste disposal system. A nonfarm tract on which a loan is to be made must have an adequate water and water/waste disposal system and other related facilities. Water and water...

7 CFR 1980.313 - Site and building requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... direct access from a street, road, or driveway. Streets and roads must be hard surface or all-weather surface. (c) Water and water/waste disposal system. A nonfarm tract on which a loan is to be made must have an adequate water and water/waste disposal system and other related facilities. Water and water...

Groundwater and surface water dynamics of Na and Cl in an urban stream: effects of road salts

EPA Science Inventory

AbstractRoad salts are a growing environmental and health concern in urban watersheds. We examined groundwater (GW) and surface water (SW) dynamics of Na and Cl in an urban stream, Minebank Run (MBR), MD. We observed an increasing salinity trend in this restored stream. Current b...

Road Asphalt Pavements Analyzed by Airborne Thermal Remote Sensing: Preliminary Results of the Venice Highway

PubMed Central

Pascucci, Simone; Bassani, Cristiana; Palombo, Angelo; Poscolieri, Maurizio; Cavalli, Rosa

2008-01-01

This paper describes a fast procedure for evaluating asphalt pavement surface defects using airborne emissivity data. To develop this procedure, we used airborne multispectral emissivity data covering an urban test area close to Venice (Italy).For this study, we first identify and select the roads' asphalt pavements on Multispectral Infrared Visible Imaging Spectrometer (MIVIS) imagery using a segmentation procedure. Next, since in asphalt pavements the surface defects are strictly related to the decrease of oily components that cause an increase of the abundance of surfacing limestone, the diagnostic absorption emissivity peak at 11.2μm of the limestone was used for retrieving from MIVIS emissivity data the areas exhibiting defects on asphalt pavements surface.The results showed that MIVIS emissivity allows establishing a threshold that points out those asphalt road sites on which a check for a maintenance intervention is required. Therefore, this technique can supply local government authorities an efficient, rapid and repeatable road mapping procedure providing the location of the asphalt pavements to be checked. PMID:27879765

Superposition of polarized waves at layered media: theoretical modeling and measurement

NASA Astrophysics Data System (ADS)

Finkele, Rolf; Wanielik, Gerd

1997-12-01

The detection of ice layers on road surfaces is a crucial requirement for a system that is designed to warn vehicle drivers of hazardous road conditions. In the millimeter wave regime at 76 GHz the dielectric constant of ice and conventional road surface materials (i.e. asphalt, concrete) is found to be nearly similar. Thus, if the layer of ice is very thin and thus is of the same shape of roughness as the underlying road surface it cannot be securely detected using conventional algorithmic approaches. The method introduced in this paper extents and applies the theoretical work of Pancharatnam on the superposition of polarized waves. The projection of the Stokes vectors onto the Poincare sphere traces a circle due to the variation of the thickness of the ice layer. The paper presents a method that utilizes the concept of wave superposition to detect this trace even if it is corrupted by stochastic variation due to rough surface scattering. Measurement results taken under real traffic conditions prove the validity of the proposed algorithms. Classification results are presented and the results discussed.

Chemistry and Photochemistry at the Surface of Urban Road Dust and Photoactive Minerals

NASA Astrophysics Data System (ADS)

Styler, S. A.; Abou-Ghanem, M.; Wickware, B.

2017-12-01

Each year, over a billion tons of dust are released into the atmosphere from arid regions. After its emission, dust can undergo efficient long-range transport to urban centres, where it can interact with local pollution sources. Another source of dust in urban regions is road dust resuspension, which is the largest anthropogenic source of primary particulate matter in both Canada and the United States. Since dust contains light-absorbing components, including iron- and titanium-containing minerals, dust-catalyzed photochemical processes have the potential to influence both the lifetime of pollutants present at the dust surface and the composition of the surrounding atmosphere. To date, most studies of dust photochemistry have focused on TiO2-mediated processes, and no studies have explored trace gas uptake at the surface of road dust. Here, we present first results from aerosol and coated-wall flow tube investigations of ozone uptake at the surface of a suite of titanium-containing minerals and road dust collected in Edmonton, Alberta. Together, this work represents a significant advance in our understanding of chemistry and photochemistry at realistic environmental interfaces.

Synthesis and luminescent properties of CaCO3:Eu3+@SiO2 phosphors with core-shell structure

NASA Astrophysics Data System (ADS)

Liu, Min; Kang, Ming; Chen, Kexu; Mou, Yongren; Sun, Rong

2018-03-01

Integrating the processes of preparation of CaCO3:Eu3+ and its surface-coating, core-shell structured CaCO3:Eu3+@SiO2 phosphors with red emission were synthesized by the carbonation method and surface precipitation procedure using sodium silicate as silica source. The phase structure, thermal stability, morphology and luminescent property of the as-synthesized samples were characterized by X-ray diffraction, Fourier transform infrared spectrum, thermal analysis, field-emission scanning electron microscopy, transmission electron microscope and photoluminescence spectra. The experimental results show that Eu3+ ions as the luminescence center are divided into two types: one is at the surface of the CaCO3 and the other inhabits the site of Ca2+. For CaCO3:Eu3+@SiO2 phosphors, the SiO2 layers are continuously coated on the surface of CaCO3:Eu3+ and show a typical core-shell structure. After coated with SiO2 layer, the luminous intensity and the compatibility with the rubber matrix increase greatly. Additionally, the luminous intensity increases with the increasing of Eu3+ ions concentration in CaCO3 core and concentration quenching occurs when Eu3+ ions concentration exceeds 7.0 mol%, while it is 5.0 mol% for CaCO3:Eu3+ phosphors. Therefore, preparation of CaCO3:Eu3+@SiO2 phosphors can not only simplify the experimental process through integrating the preparation of CaCO3:Eu3+ and SiO2 layer, but also effectively increase the luminous intensities of CaCO3:Eu3+ phosphors. The as-obtained phosphors may have potential applications in the fields of optical materials and functional polymer composite materials, such as plastics and rubbers.

The art of transparency.

PubMed

Sayim, Bilge; Cavanagh, Patrick

2011-01-01

Artists throughout the ages have discovered a number of techniques to depict transparency. With only a few exceptions, these techniques follow closely the properties of physical transparency. The two best known properties are X-junctions and the luminance relations described by Metelli. X-junctions are seen where the contours of a transparent material cross contours of the surface behind; Metelli's constraints on the luminance relations between the direct and filtered portions of the surface specify a range of luminance values that are consistent with transparency. These principles have been used by artists since the time of ancient Egypt. However, artists also discovered that stimuli can be seen as transparent even when these physical constraints are not met. Ancient Greek artists, for example, were able to depict transparent materials in simple black-and-white line drawings. Artists also learned how to represent transparency in cases where neither X-junctions nor Metelli's constraints could apply: for example, where no portions of the objects behind the transparent material extend beyond it. Many painters convincingly portrayed transparency in these cases by depicting the effects the transparent medium would have on material or object properties. Here, we show how artists employed these and other techniques revealing their anticipation of current formalizations of perceived transparency, and we suggest new, as-yet-untested principles.

The art of transparency

PubMed Central

Sayim, Bilge; Cavanagh, Patrick

2011-01-01

Artists throughout the ages have discovered a number of techniques to depict transparency. With only a few exceptions, these techniques follow closely the properties of physical transparency. The two best known properties are X-junctions and the luminance relations described by Metelli. X-junctions are seen where the contours of a transparent material cross contours of the surface behind; Metelli's constraints on the luminance relations between the direct and filtered portions of the surface specify a range of luminance values that are consistent with transparency. These principles have been used by artists since the time of ancient Egypt. However, artists also discovered that stimuli can be seen as transparent even when these physical constraints are not met. Ancient Greek artists, for example, were able to depict transparent materials in simple black-and-white line drawings. Artists also learned how to represent transparency in cases where neither X-junctions nor Metelli's constraints could apply: for example, where no portions of the objects behind the transparent material extend beyond it. Many painters convincingly portrayed transparency in these cases by depicting the effects the transparent medium would have on material or object properties. Here, we show how artists employed these and other techniques revealing their anticipation of current formalizations of perceived transparency, and we suggest new, as-yet-untested principles. PMID:23145252

Measurement of host-to-activator transfer efficiency in nano-crystalline Y{sub 2}O{sub 3}:Eu{sup 3+} under VUV excitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waite, Christopher; Mann, Rusty; Diaz, Anthony L., E-mail: DiazA@cwu.edu

2013-02-15

We have conducted a systematic study of the excitation and reflectance spectra of nano-crystalline Y{sub 2}O{sub 3}:Eu prepared by combustion synthesis. Excitation through the host lattice becomes relatively more efficient as the firing temperature of the precursor is increased, while reflectance properties remain essentially unchanged. Using these data, host-to-activator transfer efficiencies were calculated for excitation at the band edge of Y{sub 2}O{sub 3}, and evaluated using a competition kinetics model. From this analysis we conclude that the relatively low luminous efficiency of these materials is due more to poor bulk crystallinity than to surface loss effects. - Graphical abstract: Themore » low luminous efficiency of nano-crystalline Y{sub 2}O{sub 3}:Eu{sup 3+} prepared by combustion synthesis is due to poor bulk crystallinity rather than surface loss effects. Highlights: Black-Right-Pointing-Pointer We report on the optical properties of Y{sub 2}O{sub 3}:Eu{sup 3+} prepared by combustion synthesis. Black-Right-Pointing-Pointer Host-to-activator transfer efficiencies under VUV excitation were calculated. Black-Right-Pointing-Pointer The low luminous efficiency of these materials is due to poor bulk crystallinity.« less

Multiple facets of sialomucin complex/MUC4, a membrane mucin and erbb2 ligand, in tumors and tissues (Y2K update).

PubMed

Carraway, K L; Price-Schiavi, S A; Komatsu, M; Idris, N; Perez, A; Li, P; Jepson, S; Zhu, X; Carvajal, M E; Carraway, C A

2000-01-01

Sialomucin complex (SMC, MUC4) is a high Mr glycoprotein heterodimer, composed of mucin (ASGP-1) and transmembrane (ASGP-2) subunits. ASGP-2 contains two EGF-like domains and acts as an intramembrane ligand for the receptor tyrosine kinase ErbB2. Transfection studies with SMC DNAs showed that SMC expression could markedly reduce both cell-cell and cell-matrix interactions in vitro and increase the growth of primary tumors and the formation of metastatic foci of human A375 melanoma cells as xenotransplants in nude mice, possibly through the ability to suppress apoptosis. SMC is expressed in most vulnerable epithelia as a protective agent, which is found in both membrane and soluble forms at luminal surfaces and secreted into fluids such as milk and tears. SMC appears to be constitutively expressed by most accessible epithelia, notable exceptions being the mammary gland and uterine luminal epithelium, in which it is tightly regulated during pregnancy. Down-regulation at the luminal uterine surface appears necessary for blastocyst implantation. TGF-b is a potent repressor of SMC expression in the mammary gland and uterus, though by different mechanisms. These combined results suggest that SMC has multiple functions in epithelia and is tightly regulated in those tissues where its special functions are required.

Pavement Condition Assessment Using IRI from Roadroid and Surface Distress Index Method on National Road in Sumenep Regency

NASA Astrophysics Data System (ADS)

Arianto, T.; Suprapto, M.; Syafi’i

2018-03-01

The pavement condition will decrease due to the influence of traffic and environment, so that the maintenance effort is needed to maintain the road condition during the service period. In order to carry out road maintenance activities right on target, there needs to be a plan based on accurate pavement condition data. Road roughness is the most commonly used condition parameter in evaluating pavement conditions objectively because road roughness data is relatively easy to obtain, well correlated with vehicle operating costs and the most relevant parameter in road functional performance measurement. The Roadroid is an Android-based application that measures road roughness by using vibration sensors on a smartphone so it is possible to get an International Roughness Index (IRI) value as an indicator of pavement conditions more easily and efficiently. Besides based on road roughness, pavement condition evaluation can also be done visually by using Surface Distress Index (SDI) method that uses the total crack area parameters, average crack width, total number of potholes and the average depth of rutting. This study attempts to assess the condition of Jenderal Sudirman-Kalianget road by combining IRI Roadroid value and SDI value which will be used as the basis to determine the required road maintenance. This road segment is one of the national strategic road connecting the center of Sumenep regency with the Kalianget harbor. Based on IRI measurement and SDI calculation, the pavement condition of Jenderal Sudirman-Kalianget road can be described 4.2 kilometers (37.17%) were good and 2.3 kilometers (20.35%) were fair that need routine maintenance. While 2.1 kilometers (18.58%) were bad and 2.7 kilometers (23.89%) were poor that need periodical maintenance and reconstruction.

Re-entrained road dust PM10 emission from selected streets of Krakow and its impact on air quality

NASA Astrophysics Data System (ADS)

Bogacki, Marek; Mazur, Marian; Oleniacz, Robert; Rzeszutek, Mateusz; Szulecka, Adriana

2018-01-01

Scientific research studies conducted in various parts of the world confirm that PM10 concentrations in urban air depend to a great extent on the resuspension processes of the dust deposited on the road surface. The paper presents the results of the study related to the determination of the re-entrained PM10 emissions from four selected streets of Krakow (Southern Poland) together with the assessment of its impact on air quality. Examined streets are characterised by different traffic intensity (from 500 to over 20 000 vehicles per day) and individual vehicle structure. Dust material sampling and estimation of the PM10 emission were conducted according to the U.S. EPA methodology (AP 42 Fifth Edition). Two variants of sample collection were applied: from the road surface including the area at the curb (4 streets) and from the road surface alone (1 street). The estimates of resuspended road dust emission as well as the reference values derived from the U.S. EPA guidelines were used to assess the impact of this emission on the PM10 levels in the air at the location of one of the analysed streets. This assessment was conducted using the CALINE4 mathematical model. The study showed that the PM10 emissions from the re-entrained road dust can be responsible for up to 25 % in the winter and 50 % in the summer of the total PM10 concentrations in the air near the roads.

Retrieval Algorithms for Road Surface Modelling Using Laser-Based Mobile Mapping.

PubMed

Jaakkola, Anttoni; Hyyppä, Juha; Hyyppä, Hannu; Kukko, Antero

2008-09-01

Automated processing of the data provided by a laser-based mobile mapping system will be a necessity due to the huge amount of data produced. In the future, vehiclebased laser scanning, here called mobile mapping, should see considerable use for road environment modelling. Since the geometry of the scanning and point density is different from airborne laser scanning, new algorithms are needed for information extraction. In this paper, we propose automatic methods for classifying the road marking and kerbstone points and modelling the road surface as a triangulated irregular network. On the basis of experimental tests, the mean classification accuracies obtained using automatic method for lines, zebra crossings and kerbstones were 80.6%, 92.3% and 79.7%, respectively.

Automatic extraction of road features in urban environments using dense ALS data

NASA Astrophysics Data System (ADS)

Soilán, Mario; Truong-Hong, Linh; Riveiro, Belén; Laefer, Debra

2018-02-01

This paper describes a methodology that automatically extracts semantic information from urban ALS data for urban parameterization and road network definition. First, building façades are segmented from the ground surface by combining knowledge-based information with both voxel and raster data. Next, heuristic rules and unsupervised learning are applied to the ground surface data to distinguish sidewalk and pavement points as a means for curb detection. Then radiometric information was employed for road marking extraction. Using high-density ALS data from Dublin, Ireland, this fully automatic workflow was able to generate a F-score close to 95% for pavement and sidewalk identification with a resolution of 20 cm and better than 80% for road marking detection.

76 FR 35273 - CSX Transportation, Inc.; Trackage Rights Exemption; The Indiana Rail Road Company

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-16

... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [Docket No. FD 35528] CSX Transportation, Inc.; Trackage Rights Exemption; The Indiana Rail Road Company Pursuant to a supplemental trackage rights agreement (Supplemental Agreement No. 1),\\1\\ The Indiana Rail Road Company (INRD) has agreed to...

MnROAD cells 16-23 (phase II) : forensic investigation into recycled unbound base and asphalt surface materials.

DOT National Transportation Integrated Search

2017-06-01

This report presents the findings from an eight-year performance evaluation of eight cells (Cells 16-23) built at the Minnesota Road Research Facility (MnROAD) in 2008. The constructed cells were used for two performance evaluation studies of: 1) unb...

Reduction of soil erosion on forest roads

Treesearch

Edward R. Burroughs; John G. King

1989-01-01

Presents the expected reduction in surface erosion from selected treatments applied to forest road traveledways, cutslopes, fillslopes, and ditches. Estimated erosion reduction is expressed as functions of ground cover, slope gradient, and soil properties whenever possible. A procedure is provided to select rock riprap size for protection of the road ditch.

40 CFR 63.3981 - What definitions apply to this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

...-road vehicle that are painted off-vehicle to protect systems, equipment, or to allow full coverage... considered adhesives under this subpart. Assembled on-road vehicle coating means any coating operation in... or trailer intended for on-road use including, but not limited to, components or surfaces on...

40 CFR 63.3981 - What definitions apply to this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

...-road vehicle that are painted off-vehicle to protect systems, equipment, or to allow full coverage... considered adhesives under this subpart. Assembled on-road vehicle coating means any coating operation in... or trailer intended for on-road use including, but not limited to, components or surfaces on...

40 CFR 63.3981 - What definitions apply to this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

...-road vehicle that are painted off-vehicle to protect systems, equipment, or to allow full coverage... considered adhesives under this subpart. Assembled on-road vehicle coating means any coating operation in... or trailer intended for on-road use including, but not limited to, components or surfaces on...

36 CFR 1004.22 - Unsafe operation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 1004.22 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.22..., traffic, weather, road and light conditions and road character. (2) Operating a motor vehicle in a manner which unnecessarily causes its tires to squeal, skid or break free of the road surface. (3) Failing to...

A Galerkin Approach to Define Measured Terrain Surfaces with Analytic Basis Vectors to Produce a Compact Representation

DTIC Science & Technology

2010-11-01

defined herein as terrain whose surface deformation due to a single vehicle traversing the surface is negligible, such as paved roads (both asphalt ...ground vehicle reliability predictions. Current application of this work is limited to the analysis of U.S. Highways, comprised of both asphalt and...Highways that are consistent between asphalt and concrete roads b. The principle terrain characteristics are defined with analytic basis vectors

Automatic Extraction of Road Markings from Mobile Laser Scanning Data

NASA Astrophysics Data System (ADS)

Ma, H.; Pei, Z.; Wei, Z.; Zhong, R.

2017-09-01

Road markings as critical feature in high-defination maps, which are Advanced Driver Assistance System (ADAS) and self-driving technology required, have important functions in providing guidance and information to moving cars. Mobile laser scanning (MLS) system is an effective way to obtain the 3D information of the road surface, including road markings, at highway speeds and at less than traditional survey costs. This paper presents a novel method to automatically extract road markings from MLS point clouds. Ground points are first filtered from raw input point clouds using neighborhood elevation consistency method. The basic assumption of the method is that the road surface is smooth. Points with small elevation-difference between neighborhood are considered to be ground points. Then ground points are partitioned into a set of profiles according to trajectory data. The intensity histogram of points in each profile is generated to find intensity jumps in certain threshold which inversely to laser distance. The separated points are used as seed points to region grow based on intensity so as to obtain road mark of integrity. We use the point cloud template-matching method to refine the road marking candidates via removing the noise clusters with low correlation coefficient. During experiment with a MLS point set of about 2 kilometres in a city center, our method provides a promising solution to the road markings extraction from MLS data.

[Analysis of particle size characteristics of road sediments in Beijing Olympic Park].

PubMed

Li, Hai-yan; Shi, An-bang; Qu, Yang-sheng; Yue, Jing-lin

2014-09-01

Particle size analysis of road sediment collected in October and November in Beijing Olympic Park indicates that most of the sediments are 76-830 μm; the grain size of the sediments in the area of large population flow is mainly coarse but the grain size in the area of large traffic volume is fine relatively while most of the sediments are <300 p.m. Moreover, sediments of size range <300 μm can be easily accumulated on the road with moderate traffic density. The results demonstrate that the effect of pedestrian flow on the composition of the particles is unobvious and the main influences are the traffic density, extensive construction. With the length of dry period increasing, the content of sediments of size range >300 μm decreases and the content of sediments of size range < 150 μm increases, however, the change of the content of sediments of size range 150-300 μm is not obvious. The results indicate that the effectiveness of the road sediment removal depends on the length of dry period, and the accumulation of different size particles varies differently under the different dry days. Compared with the stone road, surface particles can accumulate on the asphalt road more easily as the accumulation of particles is affected by the road material significantly. Therefore, to reduce the urban surface water pollution, it is necessary to improve the design of park road such as using the stone road, which can decrease the roughness of the road.

Porosity of porcine bladder acellular matrix: impact of ACM thickness.

PubMed

Farhat, Walid; Chen, Jun; Erdeljan, Petar; Shemtov, Oren; Courtman, David; Khoury, Antoine; Yeger, Herman

2003-12-01

The objectives of this study are to examine the porosity of bladder acellular matrix (ACM) using deionized (DI) water as the model fluid and dextran as the indicator macromolecule, and to correlate the porosity to the ACM thickness. Porcine urinary bladders from pigs weighing 20-50 kg were sequentially extracted in detergent containing solutions, and to modify the ACM thickness, stretched bladders were acellularized in the same manner. Luminal and abluminal ACM specimens were subjected to fixed static DI water pressure (10 cm); and water passing through the specimens was collected at specific time interval. While for the macromolecule porosity testing, the diffusion rate and direction of 10,000 MW fluoroescein-labeled dextrans across the ACM specimens mounted in Ussing's chambers were measured. Both experiments were repeated on the thin stretched ACM. In both ACM types, the fluid porosity in both directions did not decrease with increased test duration (3 h); in addition, the abluminal surface was more porous to fluid than the luminal surface. On the other hand, when comparing thin to thick ACM, the porosity in either direction was higher in the thick ACM. Macromolecule porosity, as measured by absorbance, was higher for the abluminal thick ACM than the luminal side, but this characteristic was reversed in the thin ACM. Comparing thin to thick ACM, the luminal side in the thin ACM was more porous to dextran than in the thick ACM, but this characteristic was reversed for the abluminal side. The porcine bladder ACM possesses directional porosity and acellularizing stretched urinary bladders may increase structural density and alter fluid and macromolecule porosity. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 970-974, 2003

GROUND-BASED Paα NARROW-BAND IMAGING OF LOCAL LUMINOUS INFRARED GALAXIES. I. STAR FORMATION RATES AND SURFACE DENSITIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tateuchi, Ken; Konishi, Masahiro; Motohara, Kentaro

2015-03-15

Luminous infrared galaxies (LIRGs) are enshrouded by a large amount of dust produced by their active star formation, and it is difficult to measure their activity in optical wavelengths. We have carried out Paα narrow-band imaging observations of 38 nearby star forming galaxies including 33 LIRGs listed in the IRAS Revised Bright Galaxy Sample catalog with the Atacama Near InfraRed camera on the University of Tokyo Atacama Observatory (TAO) 1.0 m telescope (miniTAO). Star formation rates (SFRs) estimated from the Paα fluxes, corrected for dust extinction using the Balmer decrement method (typically A{sub V} ∼ 4.3 mag), show a good correlation with thosemore » from the bolometric infrared luminosity of the IRAS data within a scatter of 0.27 dex. This suggests that the correction of dust extinction for the Paα flux is sufficient in our sample. We measure the physical sizes and surface densities of infrared luminosities (Σ{sub L(IR)}) and the SFR (Σ{sub SFR}) of star forming regions for individual galaxies, and we find that most of the galaxies follow a sequence of local ultra-luminous or luminous infrared galaxies (U/LIRGs) on the L(IR)-Σ{sub L(IR)} and SFR-Σ{sub SFR} plane. We confirm that a transition of the sequence from normal galaxies to U/LIRGs is seen at L(IR) = 8 × 10{sup 10} L {sub ☉}. Also, we find that there is a large scatter in physical size, different from normal galaxies or ULIRGs. Considering the fact that most U/LIRGs are merging or interacting galaxies, this scatter may be caused by strong external factors or differences in their merging stages.« less

A neural model of border-ownership from kinetic occlusion.

PubMed

Layton, Oliver W; Yazdanbakhsh, Arash

2015-01-01

Camouflaged animals that have very similar textures to their surroundings are difficult to detect when stationary. However, when an animal moves, humans readily see a figure at a different depth than the background. How do humans perceive a figure breaking camouflage, even though the texture of the figure and its background may be statistically identical in luminance? We present a model that demonstrates how the primate visual system performs figure-ground segregation in extreme cases of breaking camouflage based on motion alone. Border-ownership signals develop as an emergent property in model V2 units whose receptive fields are nearby kinetically defined borders that separate the figure and background. Model simulations support border-ownership as a general mechanism by which the visual system performs figure-ground segregation, despite whether figure-ground boundaries are defined by luminance or motion contrast. The gradient of motion- and luminance-related border-ownership signals explains the perceived depth ordering of the foreground and background surfaces. Our model predicts that V2 neurons, which are sensitive to kinetic edges, are selective to border-ownership (magnocellular B cells). A distinct population of model V2 neurons is selective to border-ownership in figures defined by luminance contrast (parvocellular B cells). B cells in model V2 receive feedback from neurons in V4 and MT with larger receptive fields to bias border-ownership signals toward the figure. We predict that neurons in V4 and MT sensitive to kinetically defined figures play a crucial role in determining whether the foreground surface accretes, deletes, or produces a shearing motion with respect to the background. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of road salts on groundwater and surface water dynamics of socium and chloride in an urban restored stream

EPA Science Inventory

Road salts are a growing environmental concern in urban watersheds. We examined groundwater (GW) and surface water (SW) dynamics of Na+ and Cl− in Minebank Run (MBR), an urban stream in Maryland, USA. We observed an increasing salinity trend in this restored stream. Current basef...

Structure of merger remnants. I - Bulgeless progenitors

NASA Technical Reports Server (NTRS)

Hernquist, Lars

1992-01-01

The study examines mergers of identical galaxies consisting of self-gravitating disks and halos in the context of the suggestion that such events may form elliptical galaxies. It is shown that the luminous remnants of such mergers do indeed share many common properties with observed ellipticals. Specifically, the end states of the simulations considered rotate slowly in regions of relatively high surface density, having typical values of less than about 0.2 there. Morphologically, the remnants display a variety of structures, including shells and loops comprising loosely bound material and boxy and disky isophotes. The luminous matter is well-fitted by ellipsoidal generalizations of Hernquists's (1990, 1992) model for elliptical galaxies, implying that the surface brightness profiles are essentially de Vaucouleurs-like over a large radial interval. It is proposed that mergers of pure stellar disks do not represent an attractive mechanism for the production of massive elliptical galaxies.

Manufacturing polymer light emitting diode with high luminance efficiency by solution process

NASA Astrophysics Data System (ADS)

Kim, Miyoung; Jo, SongJin; Yang, Ho Chang; Yoon, Dang Mo; Kwon, Jae-Taek; Lee, Seung-Hyun; Choi, Ju Hwan; Lee, Bum-Joo; Shin, Jin-Koog

2012-06-01

While investigating polymer light emitting diodes (polymer-LEDs) fabricated by solution process, surface roughness influences electro-optical (E-O) characteristics. We expect that E-O characteristics such as luminance and power efficiency related to surface roughness and layer thickness of emitting layer with poly-9-Vinylcarbazole. In this study, we fabricated polymer organic light emitting diodes by solution process which guarantees easy, eco-friendly and low cost manufacturing for flexible display applications. In order to obtain high luminescence efficiency, E-O characteristics of these devices by varying parameters for printing process have been investigated. Therefore, we optimized process condition for polymer-LEDs by adjusting annealing temperatures of emission, thickness of emission layer showing efficiency (10.8 cd/A) at 10 mA/cm2. We also checked wavelength dependent electroluminescence spectrum in order to find the correlation between the variation of efficiency and the thickness of the layer.

General theory of frictional heating with application to rubber friction

NASA Astrophysics Data System (ADS)

Fortunato, G.; Ciaravola, V.; Furno, A.; Lorenz, B.; Persson, B. N. J.

2015-05-01

The energy dissipation in the contact regions between solids in sliding contact can result in high local temperatures which may strongly effect friction and wear. This is the case for rubber sliding on road surfaces at speeds above 1 mm s-1. We derive equations which describe the frictional heating for solids with arbitrary thermal properties. The theory is applied to rubber friction on road surfaces and we take into account that the frictional energy is partly produced inside the rubber due to the internal friction of rubber and in a thin (nanometer) interfacial layer at the rubber-road contact region. The heat transfer between the rubber and the road surface is described by a heat transfer coefficient which depends on the sliding speed. Numerical results are presented and compared to experimental data. We find that frictional heating results in a kinetic friction force which depends on the orientation of the sliding block, thus violating one of the two basic Leonardo da Vinci ‘laws’ of friction.

General theory of frictional heating with application to rubber friction.

PubMed

Fortunato, G; Ciaravola, V; Furno, A; Lorenz, B; Persson, B N J

2015-05-08

The energy dissipation in the contact regions between solids in sliding contact can result in high local temperatures which may strongly effect friction and wear. This is the case for rubber sliding on road surfaces at speeds above 1 mm s(-1). We derive equations which describe the frictional heating for solids with arbitrary thermal properties. The theory is applied to rubber friction on road surfaces and we take into account that the frictional energy is partly produced inside the rubber due to the internal friction of rubber and in a thin (nanometer) interfacial layer at the rubber-road contact region. The heat transfer between the rubber and the road surface is described by a heat transfer coefficient which depends on the sliding speed. Numerical results are presented and compared to experimental data. We find that frictional heating results in a kinetic friction force which depends on the orientation of the sliding block, thus violating one of the two basic Leonardo da Vinci 'laws' of friction.

Prognosis of flow conditions for de-centralized seepage of rainwater from roads

NASA Astrophysics Data System (ADS)

Meyer, Martin; Hasan, Issa; Sallwey, Jana; Graeber, Peter-Wolfgang

2013-04-01

Urbanization programs that include the construction of new settlements or roads lead to an increase in surface sealing. Conventional road drainage is being carried out by a rainwater sewage system coupled with collection and detention basins. This leads to local decreases in evaporation and groundwater recharge, disturbing the natural local water balance. The increased number of climate changed induced extreme precipitation events leads to a higher risk of road floodings as a result of a failure of these systems. Furthermore, the treatment of the discharge loaded with contaminants (such as heavy metals and MTBE) is resolved neither ecologically nor technologically. By using a natural, effective and sustainable evaporation and drainage strategy it is possible to reduce the probability of road floodings, to restore the natural local water balance and to establish ecologically and economically more beneficial rainwater drainage. By using PCSiWaPro®, a simulation tool for unsaturated soil zone processes developed at the Institute of Waste Management and the Technical University of Dresden, the effects of different atmospheric, hydrological and hydrogeological parameters and system conditions on the subsurface drainage flow conditions in the vicinity of a typical German highway road were studied. Special attention was given to the influence of extreme precipitation events on the drainage time at differently tilted parts of the surface, on surface drainages from lateral noise-protection barriers and on the probability of road surface underwashing. Differently constructed upper soil stratifications were tested for their ability to quickly drain water into the ground, which, besides the reduced risk of road flooding, also influence the duration time for the drainage water in each soil layer. Individual rainwater infiltration rates were applied for different regions of the model. The behaviours of three different types of soil (coarse sand, slightly silty sand and medium silty sand) were tested for their applicability as road base materials. The simulation results showed that for extreme precipitation events, the optimized decentralized road drainage system was able to discharge the accumulated rainwater. In future applications, the unsaturated flow model will be extended to a reactive transport model in order to develop strategies for optimal local drainage system design with special regard to natural purification features of different soil layer types. Additionally, PCSiWaPro® can be coupled to a groundwater model to simulate the influence of potential local groundwater contamination by road discharge on the whole underlying aquifer.

75 FR 47879 - The Indiana Rail Road Company-Abandonment Exemption-in Sullivan County, IN

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-09

... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [Docket No. AB 295 (Sub-No. 8X)] The Indiana Rail Road Company--Abandonment Exemption--in Sullivan County, IN The Indiana Rail Road Company (INRD) filed a verified notice of exemption under 49 CFR pt. 1152 subpart F--Exempt Abandonments to...

Optical microtopographic inspection of asphalt pavement surfaces

NASA Astrophysics Data System (ADS)

Costa, Manuel F. M.; Freitas, E. F.; Torres, H.; Cerezo, V.

2017-08-01

Microtopographic and rugometric characterization of surfaces is routinely and effectively performed non-invasively by a number of different optical methods. Rough surfaces are also inspected using optical profilometers and microtopographer. The characterization of road asphalt pavement surfaces produced in different ways and compositions is fundamental for economical and safety reasons. Having complex structures, including topographically with different ranges of form error and roughness, the inspection of asphalt pavement surfaces is difficult to perform non-invasively. In this communication we will report on the optical non-contact rugometric characterization of the surface of different types of road pavements performed at the Microtopography Laboratory of the Physics Department of the University of Minho.

Introduction of the Mobile Platform for the Meteorological Observations in Seoul Metropolitan City of Korea

NASA Astrophysics Data System (ADS)

Baek, K. T.; Lee, S.; Kang, M.; Lee, G.

2016-12-01

Traffic accidents due to adverse weather such as fog, heavy rainfall, flooding and road surface freezing have been increasing in Korea. To reduce damages caused by the severe weather on the road, a forecast service of combined real-time road-wise weather and the traffic situation is required. Conventional stationary meteorological observations in sparse location system are limited to observe the detailed road environment. For this reason, a mobile meteorological observation platform has been coupled in Weather Information Service Engine (WISE) which is the prototype of urban-scale high resolution weather prediction system in Seoul metropolitan area of Korea in early August 2016. The instruments onboard are designed to measure 15 meteorological parameters; pressure, temperature, relative humidity, precipitation, up/down net radiation, up/down longwave radiation, up/down shortwave radiation, road surface condition, friction coefficient, water depth, wind direction and speed. The observations from mobile platform show a distinctive advantage of data collection in need for road conditions and inputs for the numerical forecast model. In this study, we introduce and examine the feasibility of mobile observations in urban weather prediction and applications.

A method for the reduction of aerodynamic drag of road vehicles

NASA Technical Reports Server (NTRS)

Pamadi, Bandu N.; Taylor, Larry W.; Leary, Terrance O.

1990-01-01

A method is proposed for the reduction of the aerodynamic drag of bluff bodies, particularly for application to road transport vehicles. This technique consists of installation of panels on the forward surface of the vehicle facing the airstream. With the help of road tests, it was demonstrated that the attachment of proposed panels can reduce aerodynamic drag of road vehicles and result in significant fuel cost savings and conservation of energy resources.

A combined road weather forecast system to prevent road ice formation in the Adige Valley (Italy)

NASA Astrophysics Data System (ADS)

Di Napoli, Claudia; Piazza, Andrea; Antonacci, Gianluca; Todeschini, Ilaria; Apolloni, Roberto; Pretto, Ilaria

2016-04-01

Road ice is a dangerous meteorological hazard to a nation's transportation system and economy. By reducing the pavement friction with vehicle tyres, ice formation on pavements increases accident risk and delays travelling times thus posing a serious threat to road users' safety and the running of economic activities. Keeping roads clear and open is therefore essential, especially in mountainous areas where ice is likely to form during the winter period. Winter road maintenance helps to restore road efficiency and security, and its benefits are up to 8 times the costs sustained for anti-icing strategies [1]. However, the optimization of maintenance costs and the reduction of the environmental damage from over-salting demand further improvements. These can be achieved by reliable road weather forecasts, and in particular by the prediction of road surface temperatures (RSTs). RST is one of the most important parameters in determining road surface conditions. It is well known from literature that ice forms on pavements in high-humidity conditions when RSTs are below 0°C. We have therefore implemented an automatic forecast system to predict critical RSTs on a test route along the Adige Valley complex terrain, in the Italian Alps. The system considers two physical models, each computing heat and energy fluxes between the road and the atmosphere. One is Reuter's radiative cooling model, which predicts RSTs at sunrise as a function of surface temperatures at sunset and the time passed since then [2]. One is METRo (Model of the Environment and Temperature of Roads), a road weather forecast software which also considers heat conduction through road material [3]. We have applied the forecast system to a network of road weather stations (road weather information system, RWIS) installed on the test route [4]. Road and atmospheric observations from RWIS have been used as initial conditions for both METRo and Reuter's model. In METRo observations have also been coupled to meteorological forecasts from ECMWF numerical prediction model. Overnight RST minima have then been estimated automatically in nowcast mode. In this presentation we show and discuss results and performances for the 2014-2015 and 2015-2016 winter seasons. Using evaluation indexes we demonstrate that combining METRo and Reuter's models into one single forecast system improves bias and accuracy by about 0.5°C. This study is supported by the LIFE11 ENV/IT/000002 CLEAN-ROADS project. The project aims to assess the environmental impact of salt de-icers in Trentino mountain region by supporting winter road management operations with meteorological information. [1] Thornes J.E. and Stephenson D.B., Meteorological Applications, 8:307 (2001) [2] Reuter H., Tellus, 3:141 (1951) [3] Crevier L.P. and Delage Y., Journal of applied meteorology, 40:2026 (2001) [4] Pretto I. et al., SIRWEC 2014 conference proceedings, ID:0019 (2014)

GIS Data Based Automatic High-Fidelity 3D Road Network Modeling

NASA Technical Reports Server (NTRS)

Wang, Jie; Shen, Yuzhong

2011-01-01

3D road models are widely used in many computer applications such as racing games and driving simulations_ However, almost all high-fidelity 3D road models were generated manually by professional artists at the expense of intensive labor. There are very few existing methods for automatically generating 3D high-fidelity road networks, especially those existing in the real world. This paper presents a novel approach thai can automatically produce 3D high-fidelity road network models from real 2D road GIS data that mainly contain road. centerline in formation. The proposed method first builds parametric representations of the road centerlines through segmentation and fitting . A basic set of civil engineering rules (e.g., cross slope, superelevation, grade) for road design are then selected in order to generate realistic road surfaces in compliance with these rules. While the proposed method applies to any types of roads, this paper mainly addresses automatic generation of complex traffic interchanges and intersections which are the most sophisticated elements in the road networks

The Dilemma of Mountain Roads

EPA Science Inventory

Mountain roads and trails are proliferating throughout developing Southeast Asia with severe but largely unrecognized long-term consequences related to effects of landslides and surface erosion on communities and downstream resources.

Overall gloss evaluation in the presence of multiple cues to surface glossiness.

PubMed

Leloup, Frédéric B; Pointer, Michael R; Dutré, Philip; Hanselaer, Peter

2012-06-01

Human observers use the information offered by various visual cues when evaluating the glossiness of a surface. Several studies have demonstrated the effect of each single cue to glossiness, but little has been reported on how multiple cues are integrated for the perception of surface gloss. This paper reports on a psychophysical study with real stimuli that are different regarding multiple visual gloss criteria. Four samples were presented to 15 observers under different conditions of illumination in a light booth, resulting in a series of 16 stimuli. Through pairwise comparisons, an overall gloss scale was derived, from which it could be concluded that both differences in the distinctness of the reflected image and differences in luminance affect gloss perception. However, an investigation of the observers' strategy to evaluate gloss indicated a dichotomy among observers. One group of observers used the distinctness-of-image as a principal cue to glossiness, while the second group evaluated gloss primarily from differences in luminance of both the specular highlight and the diffuse background. It could therefore be questioned whether surface gloss can be characterized with one single quantity, or that a set of quantities is necessary to describe the gloss differences between objects.

The prognostic value of polycomb group protein B-cell-specific moloney murine leukemia virus insertion site 1 in stage II colon cancer patients.

PubMed

Espersen, Maiken L M; Linnemann, Dorte; Christensen, Ib J; Alamili, Mahdi; Troelsen, Jesper T; Høgdall, Estrid

2016-07-01

The aim of this study was to investigate the prognostic value of B-cell-specific moloney murine leukemia virus insertion site 1 (BMI1) protein expression in primary tumors of stage II colon cancer patients. BMI1 protein expression was assessed by immunohistochemistry in a retrospective patient cohort consisting of 144 stage II colon cancer patients. BMI1 expression at the invasive front of the primary tumors correlated with mismatch repair status of the tumors. Furthermore, BMI1 expression at the luminal surface correlated with T-stage, tumor location, and the histological subtypes of the tumors. In a univariate Cox proportional hazard analysis, no statistical significant association between risk of relapse and BMI1 protein expression at the invasive front (HR: 1.12; 95% CI 0.78-1.60; p = 0.53) or at the luminal surface of the tumor (HR: 1.06; 95% CI 0.75-1.48; p = 0.70) was found. Likewise, there was no association between 5-year overall survival and BMI1 expression at the invasive front (HR: 1.12; 95% CI 0.80-1.56; p = 0.46) or at the luminal surface of the tumor (HR: 1.16; 95% CI 0.86-1.60; p = 0.33). In conclusion, BMI1 expression in primary tumors of stage II colon cancer patients could not predict relapse or overall survival of the patients, thus having a limited prognostic value in stage II colon cancer patients. © 2016 APMIS. Published by John Wiley & Sons Ltd.

A tunable lighting system integrated by inorganic and transparent organic light-emitting diodes

NASA Astrophysics Data System (ADS)

Zhang, Jing-jing; Zhang, Tao; Jin, Ya-fang; Liu, Shi-shen; Yuan, Shi-dong; Cui, Zhao; Zhang, Li; Wang, Wei-hui

2014-05-01

A tunable surface-emitting integrated lighting system is constructed using a combination of inorganic light-emitting diodes (LEDs) and transparent organic LEDs (OLEDs). An RB two-color LED is used to supply red and blue light emission, and a green organic LED is used to supply green light emission. Currents of the LED and OLED are tuned to produce a white color, showing different Commission Internationale d'Eclairage (CIE) chromaticity coordinates and correlated color temperatures with a wide adjustable range. Such an integration can compensate for the lack of the LED's luminance uniformity and the transparent OLED's luminance intensity.

EMBLA 2000: The Optical Mission

NASA Astrophysics Data System (ADS)

Teodorani, M.; Strand, E. P.; Hauge, B. G.

2001-10-01

In August 2001 a new joint collaboration between italian physicists and norwegian engineers was succesfully carried into effect with a new mission to Norway, in order to further investigate a luminous phenomenon which is occurring recurrently in the valley of Hessdalen. The italian research-activity of this year was concentrated in the acquisition of optical data coming from conventional photography, video imaging and video-spectroscopy. Many photographs, videos and some spectra were obtained of the phenomenon. The results coming from the subsequent analysis are synthetized in seven points. A) On the basis of a photometric (point spread function) and spectroscopic (low-resolution spectra) analysis, the luminous phenomenon results to be, in the very most part of the cases, a thermal plasma. From the maximum of the Planck curve a temperature T ~ 6500 deg K is measured, which remains approximately constant for all the duration of the luminous phenomenon (sometimes up to 3 minutes), in spite of the sharp luminosity variations. B) The light-phenomenon is subject to luminosity variations on a time-scale of the order of seconds and ten seconds. A light-curve shows characteristics of semi-pulsation (about ten seconds) of the `on-off' type in the primary phase, while in the secondary phase it presents a semi-stable behaviour which is settled at the maximum luminosity and with small semi-periodic oscillations (1 second). The luminosity maxima are reached only when the radiating surface reaches the largest dimensions, by remaining the flux approximately constant. C) The luminous phenomenon when seen by naked eye appears like `light orbs', while an instrumental analysis (both video and photographic) demonstrates that the light-orbs are often constituted of many smaller orbs which appear to vibrate around a common barycenter which coincides with a larger central body, and it is evident that the central body is sometimes able to eject smaller orbs on a time-scale of the order of 1 second. The increase of the radiating surface is often due to an integrated effect which is caused by the presence of many light-components which are occasionally located just outside of the central body. D) The luminous phenomenon is able to acquire any kind of shape, sometimes also sharply geometric. E) In spite of the fact that it looks like a thermal plasma, the luminous phenomenon doesn't present, from a thermodynamic point of view, any adiabatic behaviour. This is demonstrated by the missing of an anti-correlation between the diameter of the luminous body and the flux peak-value. F) A qualitative model is presented. It is hypothesized that the luminous orbs are thermal plasma structures which are triggered by a `central force' which simulates a mini-black hole and which are internally confined by a magnetic cage. The verified missing of heat production is hypothesized to be due to a blocking of the electrons of conduction. Other models, involving the presence of magnetic monopoles, and the photoionization of low-energy plasmas by cosmic rays, are considered too. G) Once more it has been possible to demonstrate that the Hessdalen area is also featured by other targets with anomalous characteristics which seem to overlap on the more `standard luminous phenomenon', from the analysis of two of which no plasma signature was found. One of these objects presents sharply `metal like' characteristics, whose appearance in the photo after a flash exposure is interpreted to be due to an effect of stimulated emission on a substance of semiconductive kind.

Morphometry of right ventricular hypertrophy induced by myocardial infarction in the rat.

PubMed Central

Anversa, P.; Beghi, C.; McDonald, S. L.; Levicky, V.; Kikkawa, Y.; Olivetti, G.

1984-01-01

The growth response of the right ventricle was studied in rats following ligation of the left coronary artery, which produced infarcts comprising approximately 40% of the left ventricle. A month after surgery the weight of the right ventricle was increased 30%, and this hypertrophic change was characterized by a 17% wall thickening, consistent with the 13% greater diameter of myocytes. Myocardial hypertrophy was accompanied by an inadequate growth of the microvasculature that supports tissue oxygenation. This was seen by relative decreases in capillary luminal volume density (-27%) and capillary luminal surface density (-21%) and by an increase in the average maximum distance from the capillary wall to the mitochondria of myocytes (19%). In contrast, measurements of the mean myocyte volume per nucleus showed a proportional enlargement of these cells (32%), from 16,300 cu mu in control animals to 21,500 cu mu in experimental rats. Quantitative analysis of the right coronary artery revealed a 33% increase in its luminal area, commensurate with the magnitude of ventricular hypertrophy. PMID:6236695

Redox biology of the intestine

PubMed Central

Circu, Magdalena L.; Aw, Tak Yee

2011-01-01

The intestinal tract, known for its capability for self-renew, represents the first barrier of defense between the organism and its luminal environment. The thiol/disulfide redox systems comprising the glutathione/glutathione disulfide (GSH/GSSG), cysteine/cystine (Cys/CySS) and reduced and oxidized thioredoxin (Trx/TrxSS) redox couples play important roles in preserving tissue redox homeostasis, metabolic functions, and cellular integrity. Control of the thiol-disulfide status at the luminal surface is essential for maintaining mucus fluidity and absorption of nutrients, and protection against chemical-induced oxidant injury. Within intestinal cells, these redox couples preserve an environment that supports physiological processes and orchestrates networks of enzymatic reactions against oxidative stress. In this review, we focus on the intestinal redox and antioxidant systems, their subcellular compartmentation, redox signaling and epithelial turnover, and contribution of luminal microbiota, key aspects that are relevant to understanding redox-dependent processes in gut biology with implications for degenerative digestive disorders, such as inflammation and cancer. PMID:21831010

Objectification of Public Bus Stop's Pavement Surface Morphology

NASA Astrophysics Data System (ADS)

Decký, Martin; Kováč, Matúš; Mužík, Juraj; Mičechová, Lenka; Ďuriš, Lukáš

2018-06-01

The article deals with the road pavement surface morphology objectification in term of the surface unevenness degradation during the life cycle of bus stop pavements. The article presents the results of long-term rut depth measurements performed during 25 years on selected bus stops which were intended to determine correlation dependences of pavement rut depth on a number of design axles. The article also presents different methods for rut depth measurements including the straightedge test, Profilograph GE, TRIMBLE CX, and dynamic Road Scanner.

14 CFR 93.53 - Description of area.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the surface to the upper limit of each of the segments described in § 93.55. It is bounded by a line... a line bearing 180° from the intersection of the new Seward Highway and International Airport Road; thence due north to O'Malley Road; thence east along O'Malley Road to its intersection with Lake Otis...

14 CFR 93.53 - Description of area.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the surface to the upper limit of each of the segments described in § 93.55. It is bounded by a line... a line bearing 180° from the intersection of the new Seward Highway and International Airport Road; thence due north to O'Malley Road; thence east along O'Malley Road to its intersection with Lake Otis...

14 CFR 93.53 - Description of area.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the surface to the upper limit of each of the segments described in § 93.55. It is bounded by a line... a line bearing 180° from the intersection of the new Seward Highway and International Airport Road; thence due north to O'Malley Road; thence east along O'Malley Road to its intersection with Lake Otis...

14 CFR 93.53 - Description of area.

Code of Federal Regulations, 2013 CFR

2013-01-01

... the surface to the upper limit of each of the segments described in § 93.55. It is bounded by a line... a line bearing 180° from the intersection of the new Seward Highway and International Airport Road; thence due north to O'Malley Road; thence east along O'Malley Road to its intersection with Lake Otis...

Predicting forest road surface erosion and storm runoff from high-elevation sites

Treesearch

J. M. Grace III

2017-01-01

Forest roads are a concern in management because they represent areas of elevated risks associated with soil erosion and storm runoff connectivity to stream systems. Storm runoff emanating from forest roads and their connectivity to downslope resources can be influenced by a myriad of factors, including storm characteristics, management practices, and the interaction...

49 CFR 231.30 - Locomotives used in switching service.

Code of Federal Regulations, 2013 CFR

2013-10-01

... constitute a road movement. However, this term does not include movement of a train or part of a train within yard limits by the road locomotive and the placement of locomotives or cars in a train or their removal from a train by the road locomotive while en route to the train's destination. (3) Safety tread surface...

49 CFR 231.30 - Locomotives used in switching service.

Code of Federal Regulations, 2012 CFR

2012-10-01

... constitute a road movement. However, this term does not include movement of a train or part of a train within yard limits by the road locomotive and the placement of locomotives or cars in a train or their removal from a train by the road locomotive while en route to the train's destination. (3) Safety tread surface...

49 CFR 231.30 - Locomotives used in switching service.

Code of Federal Regulations, 2011 CFR

2011-10-01

... constitute a road movement. However, this term does not include movement of a train or part of a train within yard limits by the road locomotive and the placement of locomotives or cars in a train or their removal from a train by the road locomotive while en route to the train's destination. (3) Safety tread surface...

49 CFR 231.30 - Locomotives used in switching service.

Code of Federal Regulations, 2010 CFR

2010-10-01

... constitute a road movement. However, this term does not include movement of a train or part of a train within yard limits by the road locomotive and the placement of locomotives or cars in a train or their removal from a train by the road locomotive while en route to the train's destination. (3) Safety tread surface...

49 CFR 231.30 - Locomotives used in switching service.

Code of Federal Regulations, 2014 CFR

2014-10-01

... constitute a road movement. However, this term does not include movement of a train or part of a train within yard limits by the road locomotive and the placement of locomotives or cars in a train or their removal from a train by the road locomotive while en route to the train's destination. (3) Safety tread surface...

Detection of Hazardous Cavities Below a Road Using Combined Geophysical Methods

NASA Astrophysics Data System (ADS)

De Giorgi, L.; Leucci, G.

2014-07-01

Assessment of the risk arising from near-surface natural hazard is a crucial step in safeguarding the security of the roads in karst areas. It helps authorities and other related parties to apply suitable procedures for ground treatment, mitigate potential natural hazards and minimize human and economic losses. Karstic terrains in the Salento Peninsula (Apulia region—South Italy) is a major challenge to engineering constructions and roads due to extensive occurrence of cavities and/or sinkholes that cause ground subsidence and both roads and building collapse. Cavities are air/sediment-filled underground voids, commonly developed in calcarenite sedimentary rocks by the infiltration of rainwater into the ground, opening up, over a long period of time, holes and tunnels. Mitigation of natural hazards can best be achieved through careful geoscientific studies. Traditionally, engineers use destructive probing techniques for the detection of cavities across regular grids or random distances. Such probing is insufficient on its own to provide confidence that cavities will not be encountered. Frequency of probing and depth of investigation may become more expensive. Besides, probing is intrusive, non-continuous, slow, expensive and cannot provide a complete lateral picture of the subsurface geology. Near-surface cavities usually can be easily detected by surface geophysical methods. Traditional and recently developed measuring techniques in seismic, geoelectrics and georadar are suitable for economical investigation of hazardous, potentially collapsing cavities. The presented research focused on an integrated geophysical survey that was carried out in a near-coast road located at Porto Cesareo, a small village a few kilometers south west of Lecce (south Italy). The roads in this area are intensively affected by dangerous surface cracks that cause structural instability. The survey aimed to image the shallow subsurface structures, including karstic features, and evaluate their extent, as they may cause rock instability and lead to cracking of the road. Seismic refraction tomography and ground-penetrating radar surveys were carried out along several parallel traverses extending about 100 m on the cracked road. The acquired data were processed and interpreted integrally to elucidate the shallow structural setting of the site. Integrated interpretation led to the delineation of hazard zones rich with karstic features in the area. Most of these karstic features are associated with vertical and subvertical linear features and cavities. These features are the main reason of the rock instability that resulted in potentially dangerous cracking of road.

Construction dust amelioration techniques.

DOT National Transportation Integrated Search

2012-04-01

Dust produced on seasonal road construction sites in Alaska is both a traffic safety and environmental concern. Dust emanating from : unpaved road surfaces during construction severely reduces visibility and impacts stopping sight distance, and contr...

White thin-film flip-chip LEDs with uniform color temperature using laser lift-off and conformal phosphor coating technologies.

PubMed

Lin, Huan-Ting; Tien, Ching-Ho; Hsu, Chen-Peng; Horng, Ray-Hua

2014-12-29

We fabricated a phosphor-conversion white light emitting diode (PC-WLED) using a thin-film flip-chip GaN LED with a roughened u-GaN surface (TFFC-SR-LED) that emits blue light at 450 nm wavelength with a conformal phosphor coating that converts the blue light into yellow light. It was found that the TFFC-SR-LED with the thin-film substrate removal process and surface roughening exhibits a power enhancement of 16.1% when compared with the TFFC-LED without a sapphire substrate. When a TFFC-SR-LED with phosphors on a Cu-metal packaging-base (TFFC-SR-Cu-WLED) was operated at a forward-bias current of 350 mA, luminous flux and luminous efficacy were increased by 17.8 and 11.9%, compared to a TFFC-SR-LED on a Cup-shaped packaging-base (TFFC-SR-Cup-WLED). The angular correlated color temperature (CCT) deviation of a TFFC-SR-Cu-WLED reaches 77 K in the range of -70° to + 70° when the average CCT of white LEDs is around 4300 K. Consequently, the TFFC-SR-LED in a conformal coating phosphor structure on a Cu packaging-base could not only increase the luminous flux output, but also improve the angular-dependent CCT uniformity, thereby reducing the yellow ring effect.

Matrix light and pixel light: optical system architecture and requirements to the light source

NASA Astrophysics Data System (ADS)

Spinger, Benno; Timinger, Andreas L.

2015-09-01

Modern Automotive headlamps enable improved functionality for more driving comfort and safety. Matrix or Pixel light headlamps are not restricted to either pure low beam functionality or pure high beam. Light in direction of oncoming traffic is selectively switched of, potential hazard can be marked via an isolated beam and the illumination on the road can even follow a bend. The optical architectures that enable these advanced functionalities are diverse. Electromechanical shutters and lens units moved by electric motors were the first ways to realize these systems. Switching multiple LED light sources is a more elegant and mechanically robust solution. While many basic functionalities can already be realized with a limited number of LEDs, an increasing number of pixels will lead to more driving comfort and better visibility. The required optical system needs not only to generate a desired beam distribution with a high angular dynamic, but also needs to guarantee minimal stray light and cross talk between the different pixels. The direct projection of the LED array via a lens is a simple but not very efficient optical system. We discuss different optical elements for pre-collimating the light with minimal cross talk and improved contrast between neighboring pixels. Depending on the selected optical system, we derive the basic light source requirements: luminance, surface area, contrast, flux and color homogeneity.

CDOT thermal mapping report.

DOT National Transportation Integrated Search

2014-06-01

Thermal Mapping surveys were carried out on approximately 1000 miles of the Colorado Department : of Transportations (CDOTs) roads. The purpose of these surveys was to identify road surface : variations across the network to determine whether f...

Construction dust amelioration techniques : [executive summary].

DOT National Transportation Integrated Search

2012-04-01

Dust produced on seasonal road construction sites in Alaska is both a traffic safety and environmental concern. Dust emanating from : unpaved road surfaces during construction severely reduces visibility and impacts stopping sight distance, and contr...

CHAPTER 17: STORMWATER

EPA Science Inventory

The process of urbanization causes significant changes to the hydrologic regime of catchments through increased impervious areas (roads, roofs, etc) and alterations to the natural drainage network. Some examples of urbanization processes include: increasing surface area of road ...

Active Camouflage for Infantry Headwear Applications

DTIC Science & Technology

2007-02-01

incorporates a rewriteable display medium. Military, academic, and commercial groups are aiming at developing OLEDs for full- color flexible displays...as shown in Figure 7. Figure 7: Organic LED Prototype shown on a Flexible surface (Kincade, 2004). OLEDs are self-luminous and do not require...brighter, more stable color displays. The OLED manufacturing process is much more amenable to retaining optimum performance on a flexible surface

Isolation, immortalization, and characterization of a human breast epithelial cell line with stem cell properties

PubMed Central

Gudjonsson, Thorarinn; Villadsen, René; Nielsen, Helga Lind; Rønnov-Jessen, Lone; Bissell, Mina J.; Petersen, Ole William

2002-01-01

The epithelial compartment of the human breast comprises two distinct lineages: the luminal epithelial and the myoepithelial lineage. We have shown previously that a subset of the luminal epithelial cells could convert to myoepithelial cells in culture signifying the possible existence of a progenitor cell. We therefore set out to identify and isolate the putative precursor in the luminal epithelial compartment. Using cell surface markers and immunomagnetic sorting, we isolated two luminal epithelial cell populations from primary cultures of reduction mammoplasties. The major population coexpresses sialomucin (MUC+) and epithelial-specific antigen (ESA+) whereas the minor population has a suprabasal position and expresses epithelial specific antigen but no sialomucin (MUC−/ESA+). Two cell lines were further established by transduction of the E6/E7 genes from human papilloma virus type 16. Both cell lines maintained a luminal epithelial phenotype as evidenced by expression of the tight junction proteins, claudin-1 and occludin, and by generation of a high transepithelial electrical resistance on semipermeable filters. Whereas in clonal cultures, the MUC+/ESA+ epithelial cell line was luminal epithelial restricted in its differentiation repertoire, the suprabasal-derived MUC−/ESA+ epithelial cell line was able to generate itself as well as MUC+/ESA+ epithelial cells and Thy-1+/α-smooth muscle actin+ (ASMA+) myoepithelial cells. The MUC−/ESA+ epithelial cell line further differed from the MUC+/ESA+ epithelial cell line by the expression of keratin K19, a feature of a subpopulation of epithelial cells in terminal duct lobular units in vivo. Within a reconstituted basement membrane, the MUC+/ESA+ epithelial cell line formed acinus-like spheres. In contrast, the MUC−/ESA+ epithelial cell line formed elaborate branching structures resembling uncultured terminal duct lobular units both by morphology and marker expression. Similar structures were obtained by inoculating the extracellular matrix-embedded cells subcutaneously in nude mice. Thus, MUC−/ESA+ epithelial cells within the luminal epithelial lineage may function as precursor cells of terminal duct lobular units in the human breast. PMID:11914275

Effectiveness of post-fire Burned Area Emergency Response (BAER) road treatments: Results from three wildfires

Treesearch

Randy B. Foltz; Peter Robichaud

2013-01-01

Wildland fires often cause extreme changes in the landscape that drastically influence surface runoff and soil erosion, which can impact forest resources, aquatic habitats, water supplies, public safety, and forest access infrastructure such as forest roads. Little information is available on the effectiveness of various post-fire road treatments, thus this study was...

A Study on the Influence of Speed on Road Roughness Sensing: The SmartRoadSense Case †

PubMed Central

Alessandroni, Giacomo; Carini, Alberto; Lattanzi, Emanuele; Freschi, Valerio; Bogliolo, Alessandro

2017-01-01

SmartRoadSense is a crowdsensing project aimed at monitoring the conditions of the road surface. Using the sensors of a smartphone, SmartRoadSense monitors the vertical accelerations inside a vehicle traveling the road and extracts a roughness index conveying information about the road conditions. The roughness index and the smartphone GPS data are periodically sent to a central server where they are processed, associated with the specific road, and aggregated with data measured by other smartphones. This paper studies how the smartphone vertical accelerations and the roughness index are related to the vehicle speed. It is shown that the dependence can be locally approximated with a gamma (power) law. Extensive experimental results using data extracted from SmartRoadSense database confirm the gamma law relationship between the roughness index and the vehicle speed. The gamma law is then used for improving the SmartRoadSense data aggregation accounting for the effect of vehicle speed. PMID:28178224

Road profile estimation of city roads using DTPS

NASA Astrophysics Data System (ADS)

Wang, Qi; McDaniel, J. Gregory; Sun, Nian X.; Wang, Ming L.

2013-04-01

This work presents a non-destructive and non-contact acoustic sensing approach for measuring road profile of road and bridge deck with vehicles running at normal speed without stopping traffic. This approach uses an instantaneous and real-time dynamic tire pressure sensor (DTPS) that can measure dynamic response of the tire-road interaction and increases the efficiency of currently used road profile measuring systems with vehicle body-mounted profilers and axle-mounted accelerometers. In this work, a prototype of real-time DTPS system has been developed and demonstrated on a testing van at speeds from 5 to 80 miles per hour (mph). A data analysis algorithm has been developed to remove axle dynamic motions from the measured DTPS data and to find the transfer function between dynamic tire pressure change and the road profile. Field test has been performed to estimate road profiles. The road profile resolution is approximately 5 to 10 cm in width and sensitivity is 0. 3 cm for the height road surface features at driving speeds of 5 to 80 mph.

Management of paved secondary roads.

DOT National Transportation Integrated Search

1991-01-01

This report provides the background for the development of a pavement management system for the paved roads of Virginia's secondary highway system. Included are descriptions of a study to develop an acceptable surface-condition rating system for surf...

Road dust emissions from paved roads measured using different mobile systems.

PubMed

Pirjola, Liisa; Johansson, Christer; Kupiainen, Kaarle; Stojiljkovic, Ana; Karlsson, Hans; Hussein, Tareq

2010-12-01

Very few real-world measurements of road dust suspension have been performed to date. This study compares two different techniques (referred to as Sniffer and Emma) to measure road dust emissions. The main differences between the systems are the construction of the inlet, different instruments for recording particulate matter (PM) levels, and different loads on the wheel axes (the weight of Sniffer was much higher than that of Emma). Both systems showed substantial small-scale variations of emission levels along the road, likely depending on-road surface conditions. The variations observed correlated quite well, and the discrepancies are likely a result of variations in dust load on the road surface perpendicular to the driving direction that cause variations in the measurements depending on slightly different paths driven by the two vehicles. Both systems showed a substantial influence on the emission levels depending on the type of tire used. The summer tire showed much lower suspension than the winter tires (one nonstudded and one studded). However, the relative importance of the nonstudded versus studded tire was rather different. For the ratio of studded/nonstudded, Emma shows higher values on all road sections compared with Sniffer. Both techniques showed increased emission levels with increasing vehicle speed. When the speed increased from 50 to 80 km hr(-1), the relative concentrations increased by 30-170% depending on the tire type and dust load. However, for road sections that were very dirty, Sniffer showed a much higher relative increase in the emission level with the nonstudded tire. Sniffer's absolute concentrations were mostly higher than Emma's. Possible reasons for the differences are discussed in the paper. Both systems can be used for studying relative road dust emissions and for designing air quality management strategies.

Novel low-cost millimeter-wave system for road surface characterization

NASA Astrophysics Data System (ADS)

Busuioc, Dan; Anstey, Kyle; Rappaport, Carey; Birken, Ralf; Doughty, Jeffrey; Wang, Ming

2011-04-01

A novel low-cost low-complexity design based on Radar technology operating at millimeter wave is presented for the characterization of road surface conditions in real-time. At frequencies of 24-77 GHz the wavelength is long enough to obtain slight penetration in the top 1-2" of asphalt or concrete surface, but is also short enough to resolve details such as crack or pothole depth/etc. The Radar system operates by continuously outputting radiation and sampling the roadway-reflected radiation through a receiver-downconverter-sampler system. In initial laboratory testing, the received signal strength was observed to obey the inverse distance 1/R2 relationship. The received signal is further dependent on the incidence angle between the plane of the sensor and the plane of the roadway. One observation from this is the need of auxiliary sensors for determining the distance above the road surface as well as providing incident angle data. The sensor was further mounted on a movable cart used to measure the reflected signal on a variety of road surfaces (smooth, rough, surface defects, and environment factors such as various levels of moisture). By comparing measurements of the material after soaking to measurements in the dry state, there is substantial differentiation in measurements, which indicates the ability to measure the porosity of various materials. Lastly the sensor bandwidth provides the capability to measure surface roughness illustrated in the standard deviation of measurement data. On a macroscopic level, the aggregate in a roadway acts as a series of random scatterers and rough roadways or roadways with surface voids show a large variance between measurements of nearby points.

Intestinal alkaline phosphatase regulates protective surface microclimate pH in rat duodenum.

PubMed

Mizumori, Misa; Ham, Maggie; Guth, Paul H; Engel, Eli; Kaunitz, Jonathan D; Akiba, Yasutada

2009-07-15

Regulation of localized extracellular pH (pH(o)) maintains normal organ function. An alkaline microclimate overlying the duodenal enterocyte brush border protects the mucosa from luminal acid. We hypothesized that intestinal alkaline phosphatase (IAP) regulates pH(o) due to pH-sensitive ATP hydrolysis as part of an ecto-purinergic pH regulatory system, comprised of cell-surface P2Y receptors and ATP-stimulated duodenal bicarbonate secretion (DBS). To test this hypothesis, we measured DBS in a perfused rat duodenal loop, examining the effect of the competitive alkaline phosphatase inhibitor glycerol phosphate (GP), the ecto-nucleoside triphosphate diphosphohydrolase inhibitor ARL67156, and exogenous nucleotides or P2 receptor agonists on DBS. Furthermore, we measured perfusate ATP concentration with a luciferin-luciferase bioassay. IAP inhibition increased DBS and luminal ATP output. Increased luminal ATP output was partially CFTR dependent, but was not due to cellular injury. Immunofluorescence localized the P2Y(1) receptor to the brush border membrane of duodenal villi. The P2Y(1) agonist 2-methylthio-ADP increased DBS, whereas the P2Y(1) antagonist MRS2179 reduced ATP- or GP-induced DBS. Acid perfusion augmented DBS and ATP release, further enhanced by the IAP inhibitor l-cysteine, and reduced by the exogenous ATPase apyrase. Furthermore, MRS2179 or the highly selective P2Y(1) antagonist MRS2500 co-perfused with acid induced epithelial injury, suggesting that IAP/ATP/P2Y signalling protects the mucosa from acid injury. Increased DBS augments IAP activity presumably by raising pH(o), increasing the rate of ATP degradation, decreasing ATP-mediated DBS, forming a negative feedback loop. The duodenal epithelial brush border IAP-P2Y-HCO(3-) surface microclimate pH regulatory system effectively protects the mucosa from acid injury.

Capturing the sensitivity of land-use regression models to short-term mobile monitoring campaigns using air pollution micro-sensors.

PubMed

Minet, L; Gehr, R; Hatzopoulou, M

2017-11-01

The development of reliable measures of exposure to traffic-related air pollution is crucial for the evaluation of the health effects of transportation. Land-use regression (LUR) techniques have been widely used for the development of exposure surfaces, however these surfaces are often highly sensitive to the data collected. With the rise of inexpensive air pollution sensors paired with GPS devices, we witness the emergence of mobile data collection protocols. For the same urban area, can we achieve a 'universal' model irrespective of the number of locations and sampling visits? Can we trade the temporal representation of fixed-point sampling for a larger spatial extent afforded by mobile monitoring? This study highlights the challenges of short-term mobile sampling campaigns in terms of the resulting exposure surfaces. A mobile monitoring campaign was conducted in 2015 in Montreal; nitrogen dioxide (NO 2 ) levels at 1395 road segments were measured under repeated visits. We developed LUR models based on sub-segments, categorized in terms of the number of visits per road segment. We observe that LUR models were highly sensitive to the number of road segments and to the number of visits per road segment. The associated exposure surfaces were also highly dissimilar. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pollutant loads of surface runoff in Wuhan City Zoo, an urban tourist area.

PubMed

Zhao, Jian-wei; Shan, Bao-qing; Yin, Cheng-qing

2007-01-01

The pollutant loads of surface runoff in an urban tourist area have been investigated for two years in the Wuhan City Zoo, China. Eight sampling sites, including two woodlands, three animal yards, two roofs and one road, were selected for sampling and study. The results indicate that pollutants ranked in a predictable order of decreasing load (e.g. animal yard > roof > woodland > road), with animal yards acting as the key pollution source in the zoo. Pollutants were transported mainly by particulate form in runoff. Particulate nitrogen and particulate phosphorous accounted on average for 61%, 78% of total pollutant, respectively, over 13 monitored rainfall events. These results indicate the treatment practices should be implemented to improve particulate nutrient removal. Analysis of the M(V) curve indicate that no first flush effect existed in the surface runoff from pervious areas (e.g. woodland, animal ground yard), whereas a first flush effect was evident in runoff from impervious surfaces (e.g. animal cement yard, roof, road).

Advanced decision support for winter road maintenance

DOT National Transportation Integrated Search

2008-01-01

This document provides an overview of the Federal Highway Administration's winter Maintenance Decision Support System (MDSS). The MDSS is a decision support tool that has the ability to provide weather predictions focused toward the road surface. The...

Assessing Pavement Surface Splash and Spray Impact on Road Users

DOT National Transportation Integrated Search

2015-10-01

This TechBrief describes the development of an assessment tool to characterize the propensity of highway sections to generate splash and spray during rainfall and the impact of splash and spray on road users.

Baselining current road weather information : final report

DOT National Transportation Integrated Search

2009-06-10

This final report contains research findings on the characterization of the quality and value of road weather information resources used by members of the surface transportation community in their decision-making process. The objectives of the projec...

Low-cost rural surface alternatives : literature review and recommendations.

DOT National Transportation Integrated Search

2013-12-01

Freezing and thawing action induces damage to unbound gravel roads in Iowa resulting in maintenance costs for secondary road departments. Some approaches currently used by County Engineers to deal with this problem include temporarily spreading rock ...

Improving the accuracy and usability of Iowa falling weight deflectometer data : [summary].

DOT National Transportation Integrated Search

2013-05-01

Highway agencies periodically evaluate the structural condition of roads as part of their routine maintenance and rehabilitation activities. The falling-weight deflectometer (FWD) test measures road surface deflections resulting from an applied impul...

The impact of environmental factors on traffic accidents in Iran.

PubMed

Lankarani, Kamran B; Heydari, Seyed Taghi; Aghabeigi, Mohammad Reza; Moafian, Ghasem; Hoseinzadeh, Amin; Vossoughi, Mehrdad

2014-07-01

Road traffic crashes are the third highest cause of mortality in Iran. The aim of this study was to determine the impact of roadway environmental factors on traffic crash. This cross-sectional study was conducted in Iran between March 21, 2010 and December 30, 2010. The data on road traffic crashes were obtained from the Traffic Police Department records. These records were classified to control for the main confounders related to the type of crash and roadway environmental factors. Roadway environmental factors included crash scene light, weather, place of accident, the defects and geometrics of roadway and road surface. The study included 542,863 traffic crashes. The proportions of road traffic crash which led to injury were 24.44% at sunrise and 27.16% at sunset compared with 5.43% and 1.43% deaths at sunrise and sunset respectively. In regard to day time accidents, the proportions were 20.50% injuries and 0.55% deaths. The statistical analysis of the results showed that the ratio of injuries and deaths were significantly higher at sunrise and sunset than those occurring during daytime (P less than 0.001). The highest rate of death (5.07%) was due to dusty weather compared to 5.07% for other weather conditions (P less than 0.001). The highest mortality rate (3.45%) occurred on oily surfaces (P less than 0.001). The defective traffic signs were responsible for 30,046 injuries and 5.58% deaths, and road narrowing accounted for 22,775 injuries and, 4.23% deaths which indicated that the roadway defects inflict most frequent injuries and deaths. The lowest (0.74 %) and highest (3.09%) proportion of traffic crash- related deaths were due to flat straight and winding uphill/downhill roads respectively (P less than 0.001). Sunrise, sunset, dusty weather, oily road surfaces and winding uphill/downhill road were hazardous environmental factors. This study provides an insight into the potential impacts of environmental factors on road traffic accidents and underlines the implementation of appropriate preventive measures. © 2014 KUMS, All rights reserved.

Automatic 3D Extraction of Buildings, Vegetation and Roads from LIDAR Data

NASA Astrophysics Data System (ADS)

Bellakaout, A.; Cherkaoui, M.; Ettarid, M.; Touzani, A.

2016-06-01

Aerial topographic surveys using Light Detection and Ranging (LiDAR) technology collect dense and accurate information from the surface or terrain; it is becoming one of the important tools in the geosciences for studying objects and earth surface. Classification of Lidar data for extracting ground, vegetation, and buildings is a very important step needed in numerous applications such as 3D city modelling, extraction of different derived data for geographical information systems (GIS), mapping, navigation, etc... Regardless of what the scan data will be used for, an automatic process is greatly required to handle the large amount of data collected because the manual process is time consuming and very expensive. This paper is presenting an approach for automatic classification of aerial Lidar data into five groups of items: buildings, trees, roads, linear object and soil using single return Lidar and processing the point cloud without generating DEM. Topological relationship and height variation analysis is adopted to segment, preliminary, the entire point cloud preliminarily into upper and lower contours, uniform and non-uniform surface, non-uniform surfaces, linear objects, and others. This primary classification is used on the one hand to know the upper and lower part of each building in an urban scene, needed to model buildings façades; and on the other hand to extract point cloud of uniform surfaces which contain roofs, roads and ground used in the second phase of classification. A second algorithm is developed to segment the uniform surface into buildings roofs, roads and ground, the second phase of classification based on the topological relationship and height variation analysis, The proposed approach has been tested using two areas : the first is a housing complex and the second is a primary school. The proposed approach led to successful classification results of buildings, vegetation and road classes.

A semi-automated tool for reducing the creation of false closed depressions from a filled LIDAR-derived digital elevation model

USGS Publications Warehouse

Waller, John S.; Doctor, Daniel H.; Terziotti, Silvia

2015-01-01

Closed depressions on the land surface can be identified by ‘filling’ a digital elevation model (DEM) and subtracting the filled model from the original DEM. However, automated methods suffer from artificial ‘dams’ where surface streams cross under bridges and through culverts. Removal of these false depressions from an elevation model is difficult due to the lack of bridge and culvert inventories; thus, another method is needed to breach these artificial dams. Here, we present a semi-automated workflow and toolbox to remove falsely detected closed depressions created by artificial dams in a DEM. The approach finds the intersections between transportation routes (e.g., roads) and streams, and then lowers the elevation surface across the roads to stream level allowing flow to be routed under the road. Once the surface is corrected to match the approximate location of the National Hydrologic Dataset stream lines, the procedure is repeated with sequentially smaller flow accumulation thresholds in order to generate stream lines with less contributing area within the watershed. Through multiple iterations, artificial depressions that may arise due to ephemeral flow paths can also be removed. Preliminary results reveal that this new technique provides significant improvements for flow routing across a DEM and minimizes artifacts within the elevation surface. Slight changes in the stream flow lines generally improve the quality of flow routes; however some artificial dams may persist. Problematic areas include extensive road ditches, particularly along divided highways, and where surface flow crosses beneath road intersections. Limitations do exist, and the results partially depend on the quality of data being input. Of 166 manually identified culverts from a previous study by Doctor and Young in 2013, 125 are within 25 m of culverts identified by this tool. After three iterations, 1,735 culverts were identified and cataloged. The result is a reconditioned elevation dataset, which retains the karst topography for further analysis, and a culvert catalog.

Camouflage Visualization

DTIC Science & Technology

1992-04-07

reflected light seen by the viewer does not depend on the viewer’s position. Such surfaces are dull or matte and the luminance of the diffuse reflected light...vegetation and reflect only the skylight . Generally, the reflectance of the ambient light is approximately represented as a global value, constant over all the...allowing the ambient contribution provided by skylight to vary with the orientation of the surface relative to zenith. This approximation takes into

Image statistics and the perception of surface gloss and lightness.

PubMed

Kim, Juno; Anderson, Barton L

2010-07-01

Despite previous data demonstrating the critical importance of 3D surface geometry in the perception of gloss and lightness, I. Motoyoshi, S. Nishida, L. Sharan, and E. H. Adelson (2007) recently proposed that a simple image statistic--histogram or sub-band skew--is computed by the visual system to infer the gloss and albedo of surfaces. One key source of evidence used to support this claim was an experiment in which adaptation to skewed image statistics resulted in opponent aftereffects in observers' judgments of gloss and lightness. We report a series of adaptation experiments that were designed to assess the cause of these aftereffects. We replicated their original aftereffects in gloss but found no consistent aftereffect in lightness. We report that adaptation to zero-skew adaptors produced similar aftereffects as positively skewed adaptors, and that negatively skewed adaptors induced no reliable aftereffects. We further find that the adaptation effect observed with positively skewed adaptors is not robust to changes in mean luminance that diminish the intensity of the luminance extrema. Finally, we show that adaptation to positive skew reduces (rather than increases) the apparent lightness of light pigmentation on non-uniform albedo surfaces. These results challenge the view that the adaptation results reported by Motoyoshi et al. (2007) provide evidence that skew is explicitly computed by the visual system.

A hierarchical estimator development for estimation of tire-road friction coefficient

PubMed Central

Zhang, Xudong; Göhlich, Dietmar

2017-01-01

The effect of vehicle active safety systems is subject to the friction force arising from the contact of tires and the road surface. Therefore, an adequate knowledge of the tire-road friction coefficient is of great importance to achieve a good performance of these control systems. This paper presents a tire-road friction coefficient estimation method for an advanced vehicle configuration, four-motorized-wheel electric vehicles, in which the longitudinal tire force is easily obtained. A hierarchical structure is adopted for the proposed estimation design. An upper estimator is developed based on unscented Kalman filter to estimate vehicle state information, while a hybrid estimation method is applied as the lower estimator to identify the tire-road friction coefficient using general regression neural network (GRNN) and Bayes' theorem. GRNN aims at detecting road friction coefficient under small excitations, which are the most common situations in daily driving. GRNN is able to accurately create a mapping from input parameters to the friction coefficient, avoiding storing an entire complex tire model. As for large excitations, the estimation algorithm is based on Bayes' theorem and a simplified “magic formula” tire model. The integrated estimation method is established by the combination of the above-mentioned estimators. Finally, the simulations based on a high-fidelity CarSim vehicle model are carried out on different road surfaces and driving maneuvers to verify the effectiveness of the proposed estimation method. PMID:28178332

A hierarchical estimator development for estimation of tire-road friction coefficient.

PubMed

Zhang, Xudong; Göhlich, Dietmar

2017-01-01

The effect of vehicle active safety systems is subject to the friction force arising from the contact of tires and the road surface. Therefore, an adequate knowledge of the tire-road friction coefficient is of great importance to achieve a good performance of these control systems. This paper presents a tire-road friction coefficient estimation method for an advanced vehicle configuration, four-motorized-wheel electric vehicles, in which the longitudinal tire force is easily obtained. A hierarchical structure is adopted for the proposed estimation design. An upper estimator is developed based on unscented Kalman filter to estimate vehicle state information, while a hybrid estimation method is applied as the lower estimator to identify the tire-road friction coefficient using general regression neural network (GRNN) and Bayes' theorem. GRNN aims at detecting road friction coefficient under small excitations, which are the most common situations in daily driving. GRNN is able to accurately create a mapping from input parameters to the friction coefficient, avoiding storing an entire complex tire model. As for large excitations, the estimation algorithm is based on Bayes' theorem and a simplified "magic formula" tire model. The integrated estimation method is established by the combination of the above-mentioned estimators. Finally, the simulations based on a high-fidelity CarSim vehicle model are carried out on different road surfaces and driving maneuvers to verify the effectiveness of the proposed estimation method.

["Light" epithelial cells of swine and bovine oviducts].

PubMed

Suuroia, T; Aunapuu, M; Arend, A; Sépp, E

2002-01-01

The ultrastructure of oviduct epithelium of clinically healthy cows and 15 sows was investigated using scanning and transmission electron microscopy. In all parts of the oviduct, ciliated and non-ciliated epithelial cells are present, but their number varies in both the investigated animals in different regions of the oviduct, depending on the phase of the estrous cycle. In addition to ciliated cells with numerous cilia on their luminal surface, so-called pale ciliary cells were found in all parts of the oviduct of cows and sows. The cytoplasm of these cells is electron-lucent, their luminal surface carries few cilia and short microvilli. The apical cytoplasm contains species specific secretory granules, which means that these cells have features characteristic of both secretory and ciliated cells. It is suggested that the pale ciliated and non-ciliated secretory cells are functional stages of the same tubar epithelium cell, and that the transformation between these two cell types is regulated by functional requirements of the organ in different phases of the estrous cycle.

Road marking features extraction using the VIAPIX® system

NASA Astrophysics Data System (ADS)

Kaddah, W.; Ouerhani, Y.; Alfalou, A.; Desthieux, M.; Brosseau, C.; Gutierrez, C.

2016-07-01

Precise extraction of road marking features is a critical task for autonomous urban driving, augmented driver assistance, and robotics technologies. In this study, we consider an autonomous system allowing us lane detection for marked urban roads and analysis of their features. The task is to relate the georeferencing of road markings from images obtained using the VIAPIX® system. Based on inverse perspective mapping and color segmentation to detect all white objects existing on this road, the present algorithm enables us to examine these images automatically and rapidly and also to get information on road marks, their surface conditions, and their georeferencing. This algorithm allows detecting all road markings and identifying some of them by making use of a phase-only correlation filter (POF). We illustrate this algorithm and its robustness by applying it to a variety of relevant scenarios.

Measurement of deformations of models in a wind tunnel

NASA Astrophysics Data System (ADS)

Charpin, F.; Armand, C.; Selvaggini, R.

Techniques used at the ONERA Modane Center to monitor geometric variations in scale-models in wind tunnel trials are described. The methods include: photography of reflections from mirrors embedded in the model surface; laser-based torsiometry with polarized mirrors embedded in the model surface; predictions of the deformations using numerical codes for the model surface mechanical characteristics and the measured surface stresses; and, use of an optical detector to monitor the position of luminous fiber optic sources emitting from the model surfaces. The data enhance the confidence that the wind tunnel aerodynamic data will correspond with the in-flight performance of full scale flight surfaces.

Development of tiered aggregate specifications for FDOT use : [summary].

DOT National Transportation Integrated Search

2012-01-01

Limestone in Florida's peninsula plays a major : role in transportation. As a road surface, a base : layer, or as aggregate in asphalt and cement : concretes, most road building projects require : large quantities of limestone. Millions of tons : of ...

40 CFR 122.27 - Silvicultural activities (applicable to State NPDES programs, see § 123.25).

Code of Federal Regulations, 2010 CFR

2010-07-01

..., prescribed burning, pest and fire control, harvesting operations, surface drainage, or road construction and... roads) may involve point source discharges of dredged or fill material which may require a CWA section...

DETECTING EXOMOONS AROUND SELF-LUMINOUS GIANT EXOPLANETS THROUGH POLARIZATION.

PubMed

Sengupta, Sujan; Marley, Mark S

2016-01-01

Many of the directly imaged self-luminous gas giant exoplanets have been found to have cloudy atmospheres. Scattering of the emergent thermal radiation from these planets by the dust grains in their atmospheres should locally give rise to significant linear polarization of the emitted radiation. However, the observable disk averaged polarization should be zero if the planet is spherically symmetric. Rotation-induced oblateness may yield a net non-zero disk averaged polarization if the planets have sufficiently high spin rotation velocity. On the other hand, when a large natural satellite or exomoon transits a planet with cloudy atmosphere along the line of sight, the asymmetry induced during the transit should give rise to a net non-zero, time resolved linear polarization signal. The peak amplitude of such time dependent polarization may be detectable even for slowly rotating exoplanets. Therefore, we suggest that large exomoons around directly imaged self-luminous exoplanets may be detectable through time resolved imaging polarimetry. Adopting detailed atmospheric models for several values of effective temperature and surface gravity which are appropriate for self-luminous exoplanets, we present the polarization profiles of these objects in the infrared during transit phase and estimate the peak amplitude of polarization that occurs during the inner contacts of the transit ingress/egress phase. The peak polarization is predicted to range between 0.1 and 0.3 % in the infrared.

DETECTING EXOMOONS AROUND SELF-LUMINOUS GIANT EXOPLANETS THROUGH POLARIZATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sengupta, Sujan; Marley, Mark S., E-mail: sujan@iiap.res.in, E-mail: Mark.S.Marley@NASA.gov

Many of the directly imaged self-luminous gas-giant exoplanets have been found to have cloudy atmospheres. Scattering of the emergent thermal radiation from these planets by the dust grains in their atmospheres should locally give rise to significant linear polarization of the emitted radiation. However, the observable disk-averaged polarization should be zero if the planet is spherically symmetric. Rotation-induced oblateness may yield a net non-zero disk-averaged polarization if the planets have sufficiently high spin rotation velocity. On the other hand, when a large natural satellite or exomoon transits a planet with a cloudy atmosphere along the line of sight, the asymmetrymore » induced during the transit should give rise to a net non-zero, time-resolved linear polarization signal. The peak amplitude of such time-dependent polarization may be detectable even for slowly rotating exoplanets. Therefore, we suggest that large exomoons around directly imaged self-luminous exoplanets may be detectable through time-resolved imaging polarimetry. Adopting detailed atmospheric models for several values of effective temperature and surface gravity that are appropriate for self-luminous exoplanets, we present the polarization profiles of these objects in the infrared during the transit phase and estimate the peak amplitude of polarization that occurs during the inner contacts of the transit ingress/egress phase. The peak polarization is predicted to range between 0.1% and 0.3% in the infrared.« less

Detecting Exomoons Around Self-Luminous Giant Exoplanets Through Polarization

NASA Technical Reports Server (NTRS)

Sengupta, Sujan; Marley, Mark Scott

2016-01-01

Many of the directly imaged self-luminous gas giant exoplanets have been found to have cloudy atmo- spheres. Scattering of the emergent thermal radiation from these planets by the dust grains in their atmospheres should locally give rise to significant linear polarization of the emitted radiation. However, the observable disk averaged polarization should be zero if the planet is spherically symmetric. Rotation-induced oblateness may yield a net non-zero disk averaged polarization if the planets have sufficiently high spin rotation velocity. On the other hand, when a large natural satellite or exomoon transits a planet with cloudy atmosphere along the line of sight, the asymmetry induced during the transit should give rise to a net non-zero, time resolved linear polarization signal. The peak amplitude of such time dependent polarization may be detectable even for slowly rotating exoplanets. Therefore, we suggest that large exomoons around directly imaged self-luminous exoplanets may be detectable through time resolved imaging polarimetry. Adopting detailed atmospheric models for several values of effective temperature and surface gravity which are appropriate for self-luminous exoplanets, we present the polarization profiles of these objects in the infrared during transit phase and estimate the peak amplitude of polarization that occurs during the the inner contacts of the transit ingress/egress phase. The peak polarization is predicted to range between 0.1 and 0.3 % in the infrared.

DETECTING EXOMOONS AROUND SELF-LUMINOUS GIANT EXOPLANETS THROUGH POLARIZATION

PubMed Central

Sengupta, Sujan; Marley, Mark S.

2017-01-01

Many of the directly imaged self-luminous gas giant exoplanets have been found to have cloudy atmospheres. Scattering of the emergent thermal radiation from these planets by the dust grains in their atmospheres should locally give rise to significant linear polarization of the emitted radiation. However, the observable disk averaged polarization should be zero if the planet is spherically symmetric. Rotation-induced oblateness may yield a net non-zero disk averaged polarization if the planets have sufficiently high spin rotation velocity. On the other hand, when a large natural satellite or exomoon transits a planet with cloudy atmosphere along the line of sight, the asymmetry induced during the transit should give rise to a net non-zero, time resolved linear polarization signal. The peak amplitude of such time dependent polarization may be detectable even for slowly rotating exoplanets. Therefore, we suggest that large exomoons around directly imaged self-luminous exoplanets may be detectable through time resolved imaging polarimetry. Adopting detailed atmospheric models for several values of effective temperature and surface gravity which are appropriate for self-luminous exoplanets, we present the polarization profiles of these objects in the infrared during transit phase and estimate the peak amplitude of polarization that occurs during the inner contacts of the transit ingress/egress phase. The peak polarization is predicted to range between 0.1 and 0.3 % in the infrared. PMID:29430024

An approach to accidents modeling based on compounds road environments.

PubMed

Fernandes, Ana; Neves, Jose

2013-04-01

The most common approach to study the influence of certain road features on accidents has been the consideration of uniform road segments characterized by a unique feature. However, when an accident is related to the road infrastructure, its cause is usually not a single characteristic but rather a complex combination of several characteristics. The main objective of this paper is to describe a methodology developed in order to consider the road as a complete environment by using compound road environments, overcoming the limitations inherented in considering only uniform road segments. The methodology consists of: dividing a sample of roads into segments; grouping them into quite homogeneous road environments using cluster analysis; and identifying the influence of skid resistance and texture depth on road accidents in each environment by using generalized linear models. The application of this methodology is demonstrated for eight roads. Based on real data from accidents and road characteristics, three compound road environments were established where the pavement surface properties significantly influence the occurrence of accidents. Results have showed clearly that road environments where braking maneuvers are more common or those with small radii of curvature and high speeds require higher skid resistance and texture depth as an important contribution to the accident prevention. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Priority of Road Rehabilitation in Karanganyar Regency Using IRI Estimation from Roadroid

NASA Astrophysics Data System (ADS)

Achmadi, F.; Suprapto, M.; Setyawan, A.

2017-02-01

The IRI (International Roughness Index) is a road roughness index commonly obtained from measured longitudinal road profiles. This is one of the functional performance a surface of road pavement. Therefore, needs to be done evaluation and monitoring periodically to getting priority of road rehabilitation right on target. The IRI standard has commonly been used worldwide for evaluating road system. The Roadroid is an application to measure road quality with a website to view road quality. It is designed for Android smartphones, so we can easily measure and monitor the road and also use the camera for GPS-tagged photo. By using the built-in vibration sensor in smartphones, it is possible to collect IRI value which can be an indicator road conditions. This study attempts to explain the priority of road rehabilitation in Karanganyar Regency. The location of the study focused on a collector street (primary, secondary and locally road). The result of IRI estimation will be combined with other aspects that influences; land use, policy, the connectivity of road and traffic average daily. Based on IRI estimation using Roadroid, the road conditions in Karanganyar Regency can be described 59,60% were good (IRI<4,5) 21,30% fair (4,512).

Optimum display luminance depends on white luminance under various ambient illuminance conditions

NASA Astrophysics Data System (ADS)

Kim, Minkoo; Jeon, Dong-Hwan; Kim, Jeong-Sik; Yu, Byung-Chang; Park, YungKyung; Lee, Seung-Woo

2018-02-01

This paper reports display luminance levels for good visibility under nine ambient illuminance conditions (50, 100, 200, 500, 1000, 2000, 5000, 10,000, and 20,000 lx) for a given white luminance level, chosen from five candidates (100, 200, 500, 1000, and 2000 cd / m2), through a psychophysical experiment. This work reveals that the luminance levels for good visibility increase as the maximum white luminance of the display increases. The white luminance dependency of display luminance is caused by the fact that the human visual system adapts to the maximum white luminance and evaluates the brightness of the display based on it. Based on the experimental results, an appropriate luminance zone under various illuminance conditions is proposed. The appropriate luminance zone varies with the maximum white luminance of the displays. This may be understood to mean that there is no absolute luminance level under a given lighting condition. To solve this issue, a new method is proposed to determine optimum luminance levels by considering both visibility and power consumption. By the proposed method, it is reported that the optimum maximum luminance lies between 200 and 500 cd / m2 for indoor use (below 500 lx). These results were verified by young adults with normal vision.

Endogenous cyclo-oxygenase activity regulates mouse gastric surface pH

PubMed Central

Baumgartner, Heidi K; Kirbiyik, Uzay; Coskun, Tamer; Chu, Shaoyou; Montrose, Marshall H

2002-01-01

In the stomach, production of prostaglandins by cyclo-oxygenase (COX) is believed to be important in mucosal defence. We tested the hypothesis that endogenous COX activity is required for protective gastric surface pH control. Intact stomachs of anaesthetized mice were perfused with a weakly buffered solution (150 mmNaCl + 4 mm Homopipes) at pH values from 2.5 to 7.0. Gastric effluents were collected to measure pH and estimate amounts of acid or alkali secretion in nanomoles secreted per minute. A switch from net acid to net alkali secretion was seen in response to acidifying luminal pH with an apparent ‘set point’ between pH 4 and 5. At luminal pH 3, the net alkali secretion (12.7 ± 2.8 nmol OH− equivalents min−1) was abolished (2.2 ± 1.7 nmol OH− min−1) by the non-specific COX inhibitor indomethacin (5 mg kg−1 I.P.). Similar inhibition was observed using a COX-1 inhibitor (SC-560; 10 mg kg−1 I.P.), but not a COX-2 inhibitor (NS-398; 10 mg kg−1 I.P.). Subsequent treatment with 16,16-dimethyl prostaglandin E2 (dm-PGE2; 1 mg kg−1 I.P.) rescued the alkali secretion (21.8 ± 2.7 nmol OH− min−1). In either the absence or presence of the H+,K+-ATPase inhibitor omeprazole (60 mg kg−1 I.P.), indomethacin blocked similar amounts of net alkali secretion (10.5 ± 2.7 and 16.4 ± 3.4 nmol OH− min−1, respectively). We also used in vivo confocal microscopy to examine pH near the mucosal surface. The gastric mucosal surface of anaesthetized mice was exposed and mucosal surface pH was imaged using the fluorescence intensity ratio of Cl-NERF as a pH indicator. Results showed a switch from a continuous net acid to net alkali secretion by the stomach in response to changing superfusate pH from 5 to 3. At luminal pH 3, the relatively alkaline surface pH (4.3 ± 0.1) was acidified (3.6 ± 0.2) by indomethacin, and subsequent dm-PGE2 restored surface pH (4.2 ± 0.2). We conclude that the pre-epithelial alkaline layer is regulated by endogenous COX activity. PMID:12411530

Evolving Our Evaluation of Lighting Environments Project

NASA Technical Reports Server (NTRS)

Terrier, Douglas; Clayton, Ronald; Clark, Toni Anne

2016-01-01

Imagine you are an astronaut on their 100th day of your three year exploration mission. During your daily routine to the small hygiene compartment of the spacecraft, you realize that no matter what you do, your body blocks the light from the lamp. You can clearly see your hands or your toes but not both! What were those design engineers thinking! It would have been nice if they could have made the walls glow instead! The reason the designers were not more innovative is that their interpretation of the system lighting requirements didn't allow them to be so! Currently, our interior spacecraft lighting standards and requirements are written around the concept of a quantity of light illuminating a spacecraft surface. The natural interpretation for the engineer is that a lamp that throws light to the surface is required. Because of certification costs, only one lamp is designed and small rooms can wind up with lamps that may be inappropriate for the room architecture. The advances in solid state light emitting technologies and optics for lighting and visual communication necessitates the evaluation of how NASA envisions spacecraft lighting architectures and how NASA uses industry standards for the design and evaluation of lighting system. Current NASA lighting standards and requirements for existing architectures focus on the separate ability of a lighting system to throw light against a surface or the ability of a display system to provide the appropriate visual contrast. Realization that these systems can be integrated is not realized. The result is that the systems are developed independent from one another and potential efficiencies that could be realized from borrowing from the concept of one technology and applying it for the purpose of the other does not occur. This project investigated the possibility of incorporating large luminous surface lamps as an alternative or supplement to overhead lighting. We identified existing industry standards for architectural luminous or brightness uniformity as part of a lighting system definition. The efficiency of the surface lighting technology was evaluated for uniformity and power consumption. Finally, the team investigated possible performance savings if the walls were made to glow via a self luminous surface system instead of creating brightness by use of direct lighting of a highly reflective diffuse surface.

Analysis on the influence of forest soil characteristics on radioactive Cs infiltration and evaluation of residual radioactive Cs on surfaces.

PubMed

Mori, Yoshitomo; Yoneda, Minoru; Shimada, Yoko; Fukutani, Satoshi; Ikegami, Maiko; Shimomura, Ryohei

2018-03-29

We investigated the depth profiles of radioactive Cs, ignition loss, and cation exchange capacity (CEC) in five types of forest soils sampled using scraper plates. We then simulated the monitored depth profiles in a compartment model, taking ignition loss as a parameter based on experimental results showing a positive correlation between ignition loss and the CEC. The calculated values were comparable with the monitored values, though some discrepancy was observed in the middle of the soil layer. Based on decontamination data on the surface dose rate and surface contamination concentration, we newly defined a surface residual index (SRI) to evaluate the residual radioactive Cs on surfaces. The SRI value tended to gradually decrease in forests and unpaved roads and was much smaller in forests and on unpaved roads than on paved roads. The radioactive Cs was assumed to have already infiltrated underground 18 months after the nuclear power plant accident, and the sinking was assumed to be ongoing. The SRI values measured on paved roads suggested that radioactive Cs remained on the surfaces, though a gradual infiltration was observed towards the end of the monitoring term. The SRI value is thought to be effective in grasping the rough condition of residual radioactive Cs quickly at sites of decontamination activity in the field. The SRI value may be serviceable for actual contamination works after further research is done to elucidate points such as the relation between the SRI and the infiltration of radioactive Cs in various types of objects.

The analysis of tire rubber traces collected after braking incidents using Pyrolysis-GasChromatography/Mass Spectrometry.

PubMed

Sarkissian, Garry

2007-09-01

Automobile tire marks can routinely be found at the scenes of crime, particularly hit-and-run accidents and are left on road surfaces because of sudden braking or the wheels spinning. The tire marks are left due to the friction between the tire rubber and the solid road surface, and do not always demonstrate the tire tread pattern. However, the tire mark will contain traces of the tire. In this study, Pyrolysis Gas Chromatography/Mass Spectrometry was used to analyze 12 tires from different manufacturer's and their traces collected after braking incidents. Tire marks were left on a conglomerate road surface with sudden braking. The samples were pyrolysed without removal of contaminant in a micro-furnace type pyrolyser. Quantitative and qualitative analysis were performed on all the samples. All 12 samples were distinguished from each other. Each of the tire traces were identified as coming from there original source.

Sediment pathways in a tropical forest: effects of logging roads and skid trails

NASA Astrophysics Data System (ADS)

Sidle, Roy C.; Sasaki, Shozo; Otsuki, Mieko; Noguchi, Shoji; Rahim Nik, Abdul

2004-03-01

Significant erosion occurred from recently constructed forest logging roads and skid trails in a small headwater catchment in Peninsular Malaysia. Soil loss was estimated by measuring dimensions of all significant rills and gullies along the road, as well as by measuring height of preserved soil pedestals in sidecast and fill material and on skid trails. Estimates of surface erosion from logging roads and skid trails were 272 +/- 20 t ha-1 year-1 and 275 +/- 20 t ha-1 year-1 respectively. However, owing to lack of connectivity of skid trails to the stream, much of the sediment mobilized on skid trails was stored either on adjacent hillslopes or the trails themselves, rather than being transported to the stream system, as was the case for the road. Steeper skid trails (>20% gradient) had slightly higher erosion rates (320 +/- 24 t ha-1 year-1) than trails with gentler gradients (245-264 t ha-1 year-1). Some 60% of the soil loss on logging roads comes from erosion of the running surface. Disturbed cut and fill material along the road supplied the remaining 40% of the soil loss from roads. Roads and skid trails had no designed drainage systems; runoff discharged onto the hillslope at 25 major discharge nodes from the logging road (690 m total length) and at 34 nodes from skid trails (2300 m). Sediment pathways were either fully or moderately connected to headwater channels at 64% of the logging road nodes, but at only 26% of the nodes emanating from skid trails. A detailed sediment budget revealed that 78% of the soil loss from the road system (including log landings) was delivered to the stream in the first 16 months after logging began. Most (90%) of the deposition from skid trails occurred below just three discharge nodes. Runoff from and onto skid trails often exacerbated the sediment connectivity to channels. Clearly, sediment discharge from logging roads was more highly connected to the stream than discharge from skid trails. Once in the channel, much of this sediment was temporarily stored in the floodplain and behind woody debris.

Coronaridine congeners inhibit human α3β4 nicotinic acetylcholine receptors by interacting with luminal and non-luminal sites.

PubMed

Arias, Hugo R; Targowska-Duda, Katarzyna M; Feuerbach, Dominik; Jozwiak, Krzysztof

2015-08-01

To characterize the interaction of coronaridine congeners with human (h) α3β4 nicotinic acetylcholine receptors (AChRs), structural and functional approaches were used. The Ca(2+) influx results established that coronaridine congeners noncompetitively inhibit hα3β4 AChRs with the following potency (IC50's in μM) sequence: (-)-ibogamine (0.62±0.23)∼(+)-catharanthine (0.68±0.10)>(-)-ibogaine (0.95±0.10)>(±)-18-methoxycoronaridine [(±)-18-MC] (1.47±0.21)>(-)-voacangine (2.28±0.33)>(±)-18-methylaminocoronaridine (2.62±0.57 μM)∼(±)-18-hydroxycoronaridine (2.81±0.54)>(-)-noribogaine (6.82±0.78). A good linear correlation (r(2)=0.771) between the calculated IC50 values and their polar surface area was found, suggesting that this is an important structural feature for its activity. The radioligand competition results indicate that (±)-18-MC and (-)-ibogaine partially inhibit [(3)H]imipramine binding by an allosteric mechanism. Molecular docking, molecular dynamics, and in silico mutation results suggest that protonated (-)-18-MC binds to luminal [i.e., β4-Phe255 (phenylalanine/valine ring; position 13'), and α3-Leu250 and β4-Leu251 (leucine ring; position 9')], non-luminal, and intersubunit sites. The pharmacophore model suggests that nitrogens from the ibogamine core as well as methylamino, hydroxyl, and methoxyl moieties at position 18 form hydrogen bonds. Collectively our data indicate that coronaridine congeners inhibit hα3β4 AChRs by blocking the ion channel's lumen and probably by additional negative allosteric mechanisms by interacting with a series of non-luminal sites. Copyright © 2015 Elsevier Ltd. All rights reserved.

Computing multiple aggregation levels and contextual features for road facilities recognition using mobile laser scanning data

NASA Astrophysics Data System (ADS)

Yang, Bisheng; Dong, Zhen; Liu, Yuan; Liang, Fuxun; Wang, Yongjun

2017-04-01

In recent years, updating the inventory of road infrastructures based on field work is labor intensive, time consuming, and costly. Fortunately, vehicle-based mobile laser scanning (MLS) systems provide an efficient solution to rapidly capture three-dimensional (3D) point clouds of road environments with high flexibility and precision. However, robust recognition of road facilities from huge volumes of 3D point clouds is still a challenging issue because of complicated and incomplete structures, occlusions and varied point densities. Most existing methods utilize point or object based features to recognize object candidates, and can only extract limited types of objects with a relatively low recognition rate, especially for incomplete and small objects. To overcome these drawbacks, this paper proposes a semantic labeling framework by combing multiple aggregation levels (point-segment-object) of features and contextual features to recognize road facilities, such as road surfaces, road boundaries, buildings, guardrails, street lamps, traffic signs, roadside-trees, power lines, and cars, for highway infrastructure inventory. The proposed method first identifies ground and non-ground points, and extracts road surfaces facilities from ground points. Non-ground points are segmented into individual candidate objects based on the proposed multi-rule region growing method. Then, the multiple aggregation levels of features and the contextual features (relative positions, relative directions, and spatial patterns) associated with each candidate object are calculated and fed into a SVM classifier to label the corresponding candidate object. The recognition performance of combining multiple aggregation levels and contextual features was compared with single level (point, segment, or object) based features using large-scale highway scene point clouds. Comparative studies demonstrated that the proposed semantic labeling framework significantly improves road facilities recognition precision (90.6%) and recall (91.2%), particularly for incomplete and small objects.

Particulate matter emission by a vehicle running on unpaved road

NASA Astrophysics Data System (ADS)

Williams, David Scott; Shukla, Manoj K.; Ross, Jim

2008-05-01

The particulate matter (PM) emission from unpaved roads starts with the pulverization of surface material by the force of the vehicle, uplifting and subsequent exposure of road to strong air currents behind the wheels. The objectives of the project were to: demonstrate the utility of a simple technique for collecting suspended airborne PM emitted by vehicle running on an unpaved road, determine the mass balance of airborne PM at different heights, and determine the particle size and elemental composition of PM. We collected dust samples on sticky tapes using a rotorod sampler mounted on a tower across an unpaved road located at the Leyendecker Plant Sciences Research Center, Las Cruces, NM, USA. Dust samples were collected at 1.5, 4.5 and 6 m height above the ground surface on the east and west side of the road. One rotorod sampler was also installed at the centre of the road at 6 m height. Dust samples from unpaved road were mostly (70%) silt and clay-sized particles and were collected at all heights. The height and width of the PM plume and the amount of clay-sized particles captured on both sides of the road increased with speed and particle captured ranged from 0.05 to 159 μm. Dust particles between PM10 and PM2.5 did not correlate with vehicle speed but particles ⩽PM2.5 did. Emission factors estimated for the total suspended PM were 10147 g km-1 at 48 km h-1 and 11062 g km-1 at 64 km h-1 speed, respectively. The predominant elements detected in PM were carbon, aluminum and silica at all heights. Overall, sticky tape method coupled with electron microscopy was a useful technique for a rapid particle size and elemental characterization of airborne PM.

Organic Light-Emitting Diodes with a Perylene Interlayer Between the Electrode-Organic Interface

NASA Astrophysics Data System (ADS)

Saikia, Dhrubajyoti; Sarma, Ranjit

2018-01-01

The performance of an organic light-emitting diode (OLED) with a vacuum-deposited perylene layer over a fluorine-doped tin oxide (FTO) surface is reported. To investigate the effect of the perylene layer on OLED performance, different thicknesses of perylene are deposited on the FTO surface and their current density-voltages (J-V), luminance-voltages (L-V) and device efficiency characteristics at their respective thickness are studied. Further analysis is carried out with an UV-visible light double-beam spectrophotometer unit, a four-probe resistivity unit and a field emission scanning electron microscope set up to study the optical transmittance, sheet resistance and surface morphology of the bilayer anode film. We used N,N'-bis(3-methyl phenyl)- N,N'(phenyl)-benzidine (TPD) as the hole transport layer, Tris(8-hydroxyquinolinato)aluminum (Alq3) as a light-emitting layer and lithium fluoride as an electron injection layer. The luminance efficiency of an OLED structure with a 9-nm-thick perylene interlayer is increased by 2.08 times that of the single-layer FTO anode OLED. The maximum value of current efficiency is found to be 5.25 cd/A.

Tale of Terrestrial Orgins: Hypothesis for Water on the Primordial Mars

NASA Astrophysics Data System (ADS)

Brown, Cole; Williams, Darren M.

2018-06-01

It is clear from evidence obtained by Martian orbiters and rovers that the surface of Mars once had flowing water approximately 3.8 Gyr ago. At this time, however, the Sun was approximately 30% less luminous – indicating the Martian surface should not have had a temperature appropriate to explain the existence of liquid water. We investigate a potential solution to this Faint Young Sun Paradox of Mars. We show that Mars could have once been in a circumplanetary orbit about Venus where it would have had a surface temperature conducive to support liquid water given a less luminous Sun. We then model how Mars could have tidally evolved away from Venus until it eventually escaped and migrated to its present orbit. We show that, given the right initial conditions, Mars tends toward an orbit in the vicinity of its present orbit (1.52AU) after escaping Venus and that the rest of the solar system is changed insignificantly from its present configuration. Furthermore, we are working to show that the timescale of the tidal evolution is ~ 108 to 109 years -- long enough to explain the observed geological evidence of water on Mars.

Venus: The First Habitable World of Our Solar System?

NASA Technical Reports Server (NTRS)

Way, Michael Joseph; Del Genio, Anthony; Kiang, Nancy; Sohl, Linda; Clune, Tom; Aleinov, Igor; Kelley, Maxwell

2015-01-01

A great deal of effort in the search for life off-Earth in the past 20+ years has focused on Mars via a plethora of space and ground based missions. While there is good evidence that surface liquid water existed on Mars in substantial quantities, it is not clear how long such water existed. Most studies point to this water existing billions of years ago. However,those familiar with the Faint Young Sun hypothesis for Earth will quickly realize that this problem is even more pronounced for Mars. In this context recent simulations have been completed with the GISS 3-D GCM (1) of paleo Venus (approx. 3 billion years ago) when the sun was approx. 25 less luminous than today. A combination of a less luminous Sun and a slow rotation rate reveal that Venus could have had conditions on its surface amenable to surface liquid water. Previous work has also provided bounds on how much water Venus could have had using measured DH ratios. It is possible that less assumptions have to be made to make Venus an early habitable world than have to be made for Mars, even thoughVenus is a much tougher world on which to confirm this hypothesis.

Accuracy assessment of airborne LIDAR data and automated extraction of features

NASA Astrophysics Data System (ADS)

Cetin, Ali Fuat

Airborne LIDAR technology is becoming more widely used since it provides fast and dense irregularly spaced 3D point clouds. The coordinates produced as a result of calibration of the system are used for surface modeling and information extraction. In this research a new idea of LIDAR detectable targets is introduced. In the second part of this research, a new technique to delineate the edge of road pavements automatically using only LIDAR is presented. The accuracy of LIDAR data should be determined before exploitation for any information extraction to support a Geographic Information System (GIS) database. Until recently there was no definitive research to provide a methodology for common and practical assessment of both horizontal and vertical accuracy of LIDAR data for end users. The idea used in this research was to use targets of such a size and design so that the position of each target can be determined using the Least Squares Image Matching Technique. The technique used in this research can provide end users and data providers an easy way to evaluate the quality of the product, especially when there are accessible hard surfaces to install the targets. The results of the technique are determined to be in a reasonable range when the point spacing of the data is sufficient. To delineate the edge of pavements, trees and buildings are removed from the point cloud, and the road surfaces are segmented from the remaining terrain data. This is accomplished using the homogeneous nature of road surfaces in intensity and height. There are not many studies to delineate the edge of road pavement after the road surfaces are extracted. In this research, template matching techniques are used with criteria computed by Gray Level Co-occurrence Matrix (GLCM) properties, in order to locate seed pixels in the image. The seed pixels are then used for placement of the matched templates along the road. The accuracy of the delineated edge of pavement is determined by comparing the coordinates of reference points collected via photogrammetry with the coordinates of the nearest points along the delineated edge.

Improving stability of low-volume forest roads using a lignin-based emulsion

Treesearch

Robert B. Rummer; John Klepac; Harry Archer; Gerry Hebner

2001-01-01

Unitol DKG, a lignin-based emulsion used to stabilize road surfaces was tested on a low-volume forest road near Chapman, Alabama. Two replicates of three treatments were applied during October 1999 that included a 3:l dilution of Unitol DKG, a 6: 1 dilution, and pack & grade with no chemical. Also, two control sections were located at each end of the test area....

Determinants and Normal Values of Ascending Aortic Diameter by Age, Gender and Race/Ethnicity in the Multi-Ethnic Study of Atherosclerosis (MESA)

PubMed Central

Turkbey, Evrim B.; Jain, Aditya; Johnson, Craig; Redheuil, Alban; Arai, Andrew E.; Gomes, Antoinette S.; Carr, James; Hundley, W. Gregory; Teixido-Tura, Gisela; Eng, John; Lima, Joao A.C.; Bluemke, David A.

2013-01-01

PURPOSE To determine the normal size and wall thickness of the ascending thoracic aorta (AA) and its relationship with cardiovascular risk factors in a large population-based study. MATERIALS AND METHODS The mean AA luminal diameter was measured in 3573 Multi-Ethnic Study of Atherosclerosis (MESA) participants (age: 45–84 years), using gradient echo phase contrast cine MRI. Multiple linear regression models were used to evaluate the associations between risk factors and AA diameter. The median and upper normal limit (95th percentile) was defined in a “healthy” subgroup as well as AA wall thickness. RESULTS The upper limits of body surface area indexed AA luminal diameter for age categories of 45–54, 55–64, 65–74, and 75–84 years are 21, 22, 22, and 28 mm/m2 in women and 20, 21, 22, 23 mm/m2 in men, respectively. The mean AA wall thickness was 2.8 mm. Age, gender and body surface area were major determinants of AA luminal diameter (~+1 mm/10 years; ~+1.9 mm in men than women; ~+1 mm/ 0.23 m2; p<0.001). The AA diameter in hypertensive subjects was +0.9 mm larger than in normotensives (p<0.001). CONCLUSION AA diameter increases gradually with aging for both genders, among all race/ethnicities. Normal value of AA diameter is provided. PMID:23681649

Improvement in luminance of light-emitting diode using InP/ZnS quantum dot with 1-dodecanethiol ligand

NASA Astrophysics Data System (ADS)

Fukuda, Takeshi; Sasaki, Hironao

2018-03-01

We present the synthesis protocol of a red emissive InP/ZnS quantum dot with a 1-dodecanthiol ligand and its application to a quantum dot light-emitting diode. The ligand change from oleylamine to 1-dodecanthiol, which were connected around the InP/ZnS quantum dot, was confirmed by Fourier-transform infrared spectroscopy and thermal analysis. The absorption peak was blue-shifted by changing 1-dodecanthiol ligands from oleylamine ligands to prevent the unexpected nucleation of the InP core. In addition, the luminance of the light-emitting device was improved by using the InP/ZnS quantum dot with 1-dodecanthiol ligands, and the maximum current efficiency of 7.2 × 10-3 cd/A was achieved. The 1-dodecanthiol ligand is often used for capping to reduce the number of surface defects and/or prevent unexpected core growth, resulting in reduced Auger recombination. This result indicates that 1-dodecanthiol ligands prevent the deactivation of excitons while injecting carriers by applying a voltage, resulting in a high luminance efficiency.

To pave or not to pave?

DOT National Transportation Integrated Search

2006-10-01

The Issue : Two key questions must be answered when developing a gravel : road maintenance plan: : 1. What is the best way to maintain a gravel road? : 2. When should the roadway be upgraded to a paved surface? : These are not easy questions because ...

Investigation of pavement permeability : Old Bridge Road.

DOT National Transportation Integrated Search

2001-01-01

Several instances of wet pavement and pavement icing on Old Bridge Road were reported to VDOT's Lake Ridge Area Headquarters when no new precipitation had fallen. The pavement structure appears to hold water. This water seeps to the surface at a numb...

Forensic investigation of pavement distress : Old Airport Road in Bristol, Virginia.

DOT National Transportation Integrated Search

2003-01-01

A few years after Old Airport Road in Bristol, Virginia, was reconstructed, inordinate distortions of remarkable uniformity began to appear in the paved asphalt surface directly above concrete pipe culverts, which were buried beneath and across the r...

Identifying the Critical Links in Road Transportation Networks: Centrality-based approach utilizing structural properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chinthavali, Supriya

Surface transportation road networks share structural properties similar to other complex networks (e.g., social networks, information networks, biological networks, and so on). This research investigates the structural properties of road networks for any possible correlation with the traffic characteristics such as link flows those determined independently. Additionally, we define a criticality index for the links of the road network that identifies the relative importance in the network. We tested our hypotheses with two sample road networks. Results show that, correlation exists between the link flows and centrality measures of a link of the road (dual graph approach is followed) andmore » the criticality index is found to be effective for one test network to identify the vulnerable nodes.« less

Elevation data fitting and precision analysis of Google Earth in road survey

NASA Astrophysics Data System (ADS)

Wei, Haibin; Luan, Xiaohan; Li, Hanchao; Jia, Jiangkun; Chen, Zhao; Han, Leilei

2018-05-01

Objective: In order to improve efficiency of road survey and save manpower and material resources, this paper intends to apply Google Earth to the feasibility study stage of road survey and design. Limited by the problem that Google Earth elevation data lacks precision, this paper is focused on finding several different fitting or difference methods to improve the data precision, in order to make every effort to meet the accuracy requirements of road survey and design specifications. Method: On the basis of elevation difference of limited public points, any elevation difference of the other points can be fitted or interpolated. Thus, the precise elevation can be obtained by subtracting elevation difference from the Google Earth data. Quadratic polynomial surface fitting method, cubic polynomial surface fitting method, V4 interpolation method in MATLAB and neural network method are used in this paper to process elevation data of Google Earth. And internal conformity, external conformity and cross correlation coefficient are used as evaluation indexes to evaluate the data processing effect. Results: There is no fitting difference at the fitting point while using V4 interpolation method. Its external conformity is the largest and the effect of accuracy improvement is the worst, so V4 interpolation method is ruled out. The internal and external conformity of the cubic polynomial surface fitting method both are better than those of the quadratic polynomial surface fitting method. The neural network method has a similar fitting effect with the cubic polynomial surface fitting method, but its fitting effect is better in the case of a higher elevation difference. Because the neural network method is an unmanageable fitting model, the cubic polynomial surface fitting method should be mainly used and the neural network method can be used as the auxiliary method in the case of higher elevation difference. Conclusions: Cubic polynomial surface fitting method can obviously improve data precision of Google Earth. The error of data in hilly terrain areas meets the requirement of specifications after precision improvement and it can be used in feasibility study stage of road survey and design.

Using Mobile Laser Scanning Data for Features Extraction of High Accuracy Driving Maps

NASA Astrophysics Data System (ADS)

Yang, Bisheng; Liu, Yuan; Liang, Fuxun; Dong, Zhen

2016-06-01

High Accuracy Driving Maps (HADMs) are the core component of Intelligent Drive Assistant Systems (IDAS), which can effectively reduce the traffic accidents due to human error and provide more comfortable driving experiences. Vehicle-based mobile laser scanning (MLS) systems provide an efficient solution to rapidly capture three-dimensional (3D) point clouds of road environments with high flexibility and precision. This paper proposes a novel method to extract road features (e.g., road surfaces, road boundaries, road markings, buildings, guardrails, street lamps, traffic signs, roadside-trees, power lines, vehicles and so on) for HADMs in highway environment. Quantitative evaluations show that the proposed algorithm attains an average precision and recall in terms of 90.6% and 91.2% in extracting road features. Results demonstrate the efficiencies and feasibilities of the proposed method for extraction of road features for HADMs.

Influence of tyre-road contact model on vehicle vibration response

NASA Astrophysics Data System (ADS)

Múčka, Peter; Gagnon, Louis

2015-09-01

The influence of the tyre-road contact model on the simulated vertical vibration response was analysed. Three contact models were compared: tyre-road point contact model, moving averaged profile and tyre-enveloping model. In total, 1600 real asphalt concrete and Portland cement concrete longitudinal road profiles were processed. The linear planar model of automobile with 12 degrees of freedom (DOF) was used. Five vibration responses as the measures of ride comfort, ride safety and dynamic load of cargo were investigated. The results were calculated as a function of vibration response, vehicle velocity, road quality and road surface type. The marked differences in the dynamic tyre forces and the negligible differences in the ride comfort quantities were observed among the tyre-road contact models. The seat acceleration response for three contact models and 331 DOF multibody model of the truck semi-trailer was compared with the measured response for a known profile of test section.

Numerical study of aerodynamic effects on road vehicles lifting surfaces

NASA Astrophysics Data System (ADS)

Cernat, Mihail Victor; Cernat Bobonea, Andreea

2017-01-01

The aerodynamic performance analysis of road vehicles depends on the study of engine intake and cooling flow, internal ventilation, tire cooling, and overall external flow as the motion of air around a moving vehicle affects all of its components in one form or another. Due to the complex geometry of these, the aerodynamic interaction between the various body components is significant, resulting in vortex flow and lifting surface shapes. The present study, however focuses on the effects of external aerodynamics only, and in particular on the flow over the lifting surfaces of a common compact car, designed especially for this study.

Conceptual design and analysis of roads and road construction machinery for initial lunar base operations

NASA Technical Reports Server (NTRS)

Sines, Jeffrey L.; Banks, Joel; Efatpenah, Keyanoush

1990-01-01

Recent developments have made it possible for scientists and engineers to consider returning to the Moon to build a manned lunar base. The base can be used to conduct scientific research, develop new space technology, and utilize the natural resources of the Moon. Areas of the base will be separated, connected by a system of roads that reduce the power requirements of vehicles traveling on them. Feasible road types for the lunar surface were analyzed and a road construction system was designed for initial lunar base operations. A model was also constructed to show the system configuration and key operating features. The alternate designs for the lunar road construction system were developed in four stages: analyze and select a road type; determine operations and machinery needed to produce the road; develop machinery configurations; and develop alternates for several machine components. A compacted lunar soil road was selected for initial lunar base operations. The only machinery required to produce this road were a grader and a compactor. The road construction system consists of a main drive unit which is used for propulsion, a detachable grader assembly, and a towed compactor.

The influence of surface on the running velocities of elite and amateur orienteer athletes.

PubMed

Hébert-Losier, K; Jensen, K; Mourot, L; Holmberg, H-C

2014-12-01

We compared the reduction in running velocities from road to off-road terrain in eight elite and eight amateur male orienteer athletes to investigate whether this factor differentiates elite from amateur athletes. On two separate days, each subject ran three 2-km time trials and three 20-m sprints "all-out" on a road, on a path, and in a forest. On a third day, the running economy and maximal aerobic power of individuals were assessed on a treadmill. The elite orienteer ran faster than the amateur on all three surfaces and at both distances, in line with their better running economy and aerobic power. In the forest, the elites ran at a slightly higher percentage of their 2-km (∼3%) and 20-m (∼4%) road velocities. Although these differences did not exhibit traditional statistical significance, magnitude-based inferences suggested likely meaningful differences, particularly during 20-m sprinting. Of course, cognitive, mental, and physical attributes other than the ability to run on different surfaces are required for excellence in orienteering (e.g., a high aerobic power). However, we suggest that athlete-specific assessment of running performance on various surfaces and distances might assist in tailoring training and identifying individual strengths and/or weaknesses in an orienteer. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Using expansive grasses for monitoring heavy metal pollution in the vicinity of roads.

PubMed

Vachová, Pavla; Vach, Marek; Najnarová, Eva

2017-10-01

We propose a method for monitoring heavy metal deposition in the vicinity of roads using the leaf surfaces of two expansive grass species which are greatly abundant. A principle of the proposed procedure is to minimize the number of operations in collecting and preparing samples for analysis. The monitored elements are extracted from the leaf surfaces using dilute nitric acid directly in the sample-collection bottle. The ensuing steps, then, are only to filter the extraction solution and the elemental analysis itself. The verification results indicate that the selected grasses Calamagrostis epigejos and Arrhenatherum elatius are well suited to the proposed procedure. Selected heavy metals (Zn, Cu, Pb, Ni, Cr, and Cd) in concentrations appropriate for direct determination using methods of elemental analysis can be extracted from the surface of leaves of these species collected in the vicinity of roads with medium traffic loads. Comparing the two species showed that each had a different relationship between the amounts of deposited heavy metals and distance from the road. This disparity can be explained by specific morphological properties of the two species' leaf surfaces. Due to the abundant occurrence of the two species and the method's general simplicity and ready availability, we regard the proposed approach to constitute a broadly usable and repeatable one for producing reproducible results. Copyright © 2017 Elsevier Ltd. All rights reserved.

Keratin, luminal epithelial antigen and carcinoembryonic antigen in human urinary bladder carcinomas. An immunohistochemical study.

PubMed

Nathrath, W B; Arnholdt, H; Wilson, P D

1982-01-01

14 urinary bladder carcinomas of all main types were investigated with antisera to "broad spectrum keratin" (aK), "luminal epithelial antigen" (aLEA) and carcinoembryonic antigen (aCEA), using an indirect immunoperoxidase method on formalin fixed paraffin embedded sections. Keratin and LEA were both present in normal transitional epithelium, papilloma and carcinoma in situ whereas CEA was absent. Transitional cell carcinomas reacted with both aK and aLEA whereas CEA was seen only in a few foci. In squamous metaplasia and squamous carcinoma reaction with aK was particularly strong, while LEA was almost lacking and CEA was present in necrotic centres. In adenocarcinomas aK and aLEA reacted equally while aCEA reacted only on the surface.

Flux of Kilogram-Sized Meteoroids from Lunar Impact Monitoring

NASA Technical Reports Server (NTRS)

Suggs, Robert; Suggs, Ron; Cooke, William; McNamara, Heather; Diekmann, Anne; Moser, Danielle; Swift, Wesley

2008-01-01

Routine lunar impact monitoring has harvested over 110 impacts in 2 years of observations using 0.25, 0.36 and 0.5 m telescopes and low-light-level video cameras. The night side of the lunar surface provides a large collecting area for detecting these impacts and allows estimation of the flux of meteoroids down to a limiting luminous energy. In order to determine the limiting mass for these observations, models of the sporadic meteoroid environment were used to determine the velocity distribution and new measurements of luminous efficiency were made at the Ames Vertical Gun Range. The flux of meteoroids in this size range has implications for Near Earth Object populations as well as for estimating impact ejecta risk for future lunar missions.

R-LINE: A Line Source Dispersion Model for Near-Surface Releases

EPA Science Inventory

Based on Science Advisory Board and the National Research Councilrecommendations, EPA-ORD initiated research on near-road air quality andhealth effects. Field measurements indicated that exposures to traffic-emitted air pollutants near roads can be influenced by complexities of r...

Analysis of hourly crash likelihood using unbalanced panel data mixed logit model and real-time driving environmental big data.

PubMed

Chen, Feng; Chen, Suren; Ma, Xiaoxiang

2018-06-01

Driving environment, including road surface conditions and traffic states, often changes over time and influences crash probability considerably. It becomes stretched for traditional crash frequency models developed in large temporal scales to capture the time-varying characteristics of these factors, which may cause substantial loss of critical driving environmental information on crash prediction. Crash prediction models with refined temporal data (hourly records) are developed to characterize the time-varying nature of these contributing factors. Unbalanced panel data mixed logit models are developed to analyze hourly crash likelihood of highway segments. The refined temporal driving environmental data, including road surface and traffic condition, obtained from the Road Weather Information System (RWIS), are incorporated into the models. Model estimation results indicate that the traffic speed, traffic volume, curvature and chemically wet road surface indicator are better modeled as random parameters. The estimation results of the mixed logit models based on unbalanced panel data show that there are a number of factors related to crash likelihood on I-25. Specifically, weekend indicator, November indicator, low speed limit and long remaining service life of rutting indicator are found to increase crash likelihood, while 5-am indicator and number of merging ramps per lane per mile are found to decrease crash likelihood. The study underscores and confirms the unique and significant impacts on crash imposed by the real-time weather, road surface, and traffic conditions. With the unbalanced panel data structure, the rich information from real-time driving environmental big data can be well incorporated. Copyright © 2018 National Safety Council and Elsevier Ltd. All rights reserved.

Prediction of Mass Wasting, Erosion, and Sediment Transport With the Distributed Hydrology-Soil-Vegetation Model

NASA Astrophysics Data System (ADS)

Doten, C. O.; Lanini, J. S.; Bowling, L. C.; Lettenmaier, D. P.

2004-12-01

Erosion and sediment transport in a temperate forested watershed are predicted with a new sediment module linked to the Distributed Hydrology-Soil-Vegetation Model (DHSVM). The DHSVM sediment module represents the main sources of sediment generation in forested environments: mass wasting, hillslope erosion and road surface erosion. It produces failures based on a factor-of-safety analysis with the infinite slope model through use of stochastically generated soil and vegetation parameters. Failed material is routed downslope with a rule-based scheme that determines sediment delivery to streams. Sediment from hillslopes and road surfaces is also transported to the channel network. Basin sediment yield is predicted with a simple channel sediment routing scheme. The model was applied to the Rainy Creek catchment, a tributary of the Wenatchee River which drains the east slopes of the Cascade Mountains, and Hard and Ware Creeks on the west slopes of the Cascades. In these initial applications, the model produced plausible sediment yield and ratios of landsliding and surface erosion , when compared to published rates for similar catchments in the Pacific Northwest. We have also used the model to examine the implications of fires and logging road removal on sediment generation in the Rainy Creek catchment. Generally, in absolute value, the predicted changes (increased sediment generation) following fires, which are primarily associated with increased slope failures, are much larger than the modest changes (reductions in sediment yield) associated with road obliteration, although the small sensitivity to forest road obliteration may be due in part to the relatively low road density in the Rainy Creek catchment, and to mechanisms, such as culvert failure, that are not represented in the model.

Geospatial and Remote Sensing-based Indicators of Settlement Type---Differentiating Informal and Formal Settlements in Guatemala City

NASA Astrophysics Data System (ADS)

Owen, Karen K.

This research addresses the need for reliable, repeatable, quantitative measures to differentiate informal (slum) from formal (planned) settlements using commercial very high resolution imagery and elevation data. Measuring the physical, spatial and spectral qualities of informal settlements is an important precursor for evaluating success toward improving the lives of 100 million slum dwellers worldwide, as pledged by the United Nations Millennium Development Goal Target 7D. A variety of measures were tested based on surface material spectral properties, texture, built-up structure, road network accessibility, and geomorphology from twelve communities in Guatemala City to reveal statistically significant differences between informal and formal settlements that could be applied to other parts of the world without the need for costly or dangerous field surveys. When information from satellite imagery is constrained to roads and residential boundaries, a more precise understanding of human habitation is produced. A classification and regression tree (CART) approach and linear discriminant function analysis enabled a variable dimensionality reduction from the original 23 to 6 variables that are sufficient to differentiate a settlement as informal or formal. The results demonstrate that the entropy texture of roads, the degree of asphalt road surface, the vegetation patch compactness and patch size, the percent of bare soil land cover, the geomorphic profile convexity of the terrain, and the road density distinguish informal from formal settlements with 87--92% accuracy when results are cross-validated. The variables with highest contribution to model outcome that are common to both approaches are entropy texture of roads, vegetation patch size, and vegetation compactness suggesting that road texture, surface materials and vegetation provide the necessary characteristics to distinguish the level of informality of a settlement. The results will assist urban planners and settlement analysts who must process vast amounts of imagery worldwide, enabling them to report annually on slum conditions. An added benefit is the ability to use the measures in data-poor regions of the world without field surveys.

Survey of the Influence of the Width of Urban Branch Roads on the Meeting of Two-Way Vehicle Flows

PubMed Central

Chen, Qun; Zhao, Yunan; Pan, Shuangli; Wang, Yan

2016-01-01

Branch roads, which are densely distributed in cities, allow for the flow of local traffic and provide connections between the city and outlying areas. Branch roads are typically narrow, and two-way traffic flows on branch roads are thus affected when vehicles traveling in opposite directions meet. This study investigates the changes in the velocities of vehicles when they meet on two-way branch roads. Various widths of branch roads were selected, and their influence on traffic flows was investigated via a video survey. The results show that, depending on the average vehicle velocity, branch roads require different widths to prevent a large decrease in velocity when vehicles meet. When the velocity on a branch road is not high (e.g., the average velocity without meeting is approximately 6 m/s), appropriately increasing the road width will notably increase the meeting velocity. However, when the velocity is high (e.g., the average velocity without meeting is greater than 10 m/s), there is a large decrease in velocity when meeting even if the road surface is wide (6.5 m). This study provides a basis for selecting the width of urban branch roads and the simulation of bidirectional traffic on such roads. PMID:26881427

Survey of the Influence of the Width of Urban Branch Roads on the Meeting of Two-Way Vehicle Flows.

PubMed

Chen, Qun; Zhao, Yunan; Pan, Shuangli; Wang, Yan

2016-01-01

Branch roads, which are densely distributed in cities, allow for the flow of local traffic and provide connections between the city and outlying areas. Branch roads are typically narrow, and two-way traffic flows on branch roads are thus affected when vehicles traveling in opposite directions meet. This study investigates the changes in the velocities of vehicles when they meet on two-way branch roads. Various widths of branch roads were selected, and their influence on traffic flows was investigated via a video survey. The results show that, depending on the average vehicle velocity, branch roads require different widths to prevent a large decrease in velocity when vehicles meet. When the velocity on a branch road is not high (e.g., the average velocity without meeting is approximately 6 m/s), appropriately increasing the road width will notably increase the meeting velocity. However, when the velocity is high (e.g., the average velocity without meeting is greater than 10 m/s), there is a large decrease in velocity when meeting even if the road surface is wide (6.5 m). This study provides a basis for selecting the width of urban branch roads and the simulation of bidirectional traffic on such roads.

GIS-based automated management of highway surface crack inspection system

NASA Astrophysics Data System (ADS)

Chung, Hung-Chi; Shinozuka, Masanobu; Soeller, Tony; Girardello, Roberto

2004-07-01

An automated in-situ road surface distress surveying and management system, AMPIS, has been developed on the basis of video images within the framework of GIS software. Video image processing techniques are introduced to acquire, process and analyze the road surface images obtained from a moving vehicle. ArcGIS platform is used to integrate the routines of image processing and spatial analysis in handling the full-scale metropolitan highway surface distress detection and data fusion/management. This makes it possible to present user-friendly interfaces in GIS and to provide efficient visualizations of surveyed results not only for the use of transportation engineers to manage road surveying documentations, data acquisition, analysis and management, but also for financial officials to plan maintenance and repair programs and further evaluate the socio-economic impacts of highway degradation and deterioration. A review performed in this study on fundamental principle of Pavement Management System (PMS) and its implementation indicates that the proposed approach of using GIS concept and its tools for PMS application will reshape PMS into a new information technology-based system that can provide convenient and efficient pavement inspection and management.

Assessment of lead, cadmium, and zinc contamination of roadside soils, surface films, and vegetables in Kampala City, Uganda.

PubMed

Nabulo, Grace; Oryem-Origa, Hannington; Diamond, Miriam

2006-05-01

The relationship between traffic density and trace metal concentrations in roadside soils, surface films, and a selected vegetable weed, Amaranthus dubius Mart. Ex Thell., was determined in 11 farming sites along major highways around Kampala City in Uganda. Surface soil, atmospherically deposited surface films on windows, and leaves of Amaranthus dubius were sampled at known distances from the roads and analyzed for lead (Pb), zinc (Zn), and cadmium (Cd) using flame atomic absorption spectrophotometry. Atmospherically deposited trace metal particulates were sampled using window glass as an inert, passive collector. Total trace metal concentrations in soils ranged from 30.0+/-2.3 to 64.6+/-11.7 mg/kg Pb, 78.4+/-18.4 to 265.6+/-63.2 mg/kg Zn, and 0.8+/-0.13 to 1.40+/-0.16 mg/kg Cd. Total trace metal levels in soil decreased rapidly with distance from the road. Total Pb decreased with distance up to 30 m from the road, where it reached a background soil concentration of 28 mg/kg dry weight. The study found background values of 50 and 1.4 mg/kg for Zn and Cd in roadside soils, respectively. Similarly, Pb concentration in Amaranthus dubius leaves decreased with increasing distance from the road edge. The dominant pathway for Pb contamination was from atmospheric deposition, which was consistent with Pb concentrations in surface films. The mean Pb concentrations in leaves of roadside crops were higher than those in their respective roots, with the highest leaf-to-root ratio observed in the Brassica oleraceae acephala group. The lowest Pb and Zn concentrations were found in the fruit compared to the leaves of the same crops. Leaves of roadside vegetables were therefore considered a potential source of heavy metal contamination to farmers and consumers in urban areas. It is recommended that leafy vegetables should be grown 30 m from roads in high-traffic, urban areas.

Assessment of lead, cadmium, and zinc contamination of roadside soils, surface films, and vegetables in Kampala City, Uganda

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nabulo, Grace; Oryem-Origa, Hannington; Diamond, Miriam

2006-05-15

The relationship between traffic density and trace metal concentrations in roadside soils, surface films, and a selected vegetable weed, Amaranthus dubius Mart. Ex Thell., was determined in 11 farming sites along major highways around Kampala City in Uganda. Surface soil, atmospherically deposited surface films on windows, and leaves of Amaranthus dubius were sampled at known distances from the roads and analyzed for lead (Pb), zinc (Zn), and cadmium (Cd) using flame atomic absorption spectrophotometry. Atmospherically deposited trace metal particulates were sampled using window glass as an inert, passive collector. Total trace metal concentrations in soils ranged from 30.0{+-}2.3 to 64.6{+-}11.7more » mg/kg Pb, 78.4{+-}18.4 to 265.6{+-}63.2 mg/kg Zn, and 0.8{+-}0.13 to 1.40{+-}0.16 mg/kg Cd. Total trace metal levels in soil decreased rapidly with distance from the road. Total Pb decreased with distance up to 30 m from the road, where it reached a background soil concentration of 28 mg/kg dry weight. The study found background values of 50 and 1.4 mg/kg for Zn and Cd in roadside soils, respectively. Similarly, Pb concentration in Amaranthus dubius leaves decreased with increasing distance from the road edge. The dominant pathway for Pb contamination was from atmospheric deposition, which was consistent with Pb concentrations in surface films. The mean Pb concentrations in leaves of roadside crops were higher than those in their respective roots, with the highest leaf-to-root ratio observed in the Brassica oleraceae acephala group. The lowest Pb and Zn concentrations were found in the fruit compared to the leaves of the same crops. Leaves of roadside vegetables were therefore considered a potential source of heavy metal contamination to farmers and consumers in urban areas. It is recommended that leafy vegetables should be grown 30 m from roads in high-traffic, urban areas.« less

30 CFR 816.151 - Primary roads.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., or greater event as specified by the regulatory authority; (2) Drainage pipes and culverts shall be... drainage over the road surface and embankment; (4) Culverts shall be installed and maintained to sustain... intermittent stream channel crossings shall be made using bridges, culverts, low-water crossings, or other...

30 CFR 816.151 - Primary roads.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., or greater event as specified by the regulatory authority; (2) Drainage pipes and culverts shall be... drainage over the road surface and embankment; (4) Culverts shall be installed and maintained to sustain... intermittent stream channel crossings shall be made using bridges, culverts, low-water crossings, or other...

30 CFR 816.151 - Primary roads.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., or greater event as specified by the regulatory authority; (2) Drainage pipes and culverts shall be... drainage over the road surface and embankment; (4) Culverts shall be installed and maintained to sustain... intermittent stream channel crossings shall be made using bridges, culverts, low-water crossings, or other...

Black ice detection and road closure control system for Oklahoma.

DOT National Transportation Integrated Search

2014-10-01

Black ice is a thin coating of glazed ice on roadways or other transportation surfaces. Black : ice has identical appearance with black pavement and wet road, and it often forms during calm : weather. It is highly transparent and thus difficult to se...

Baselining current road weather information : results of the 2010 quality and importance survey final report.

DOT National Transportation Integrated Search

2011-01-30

This final report contains research findings on the characterization of the quality and value of road weather information resources used by members of the surface transportation community in their decision-making process. This report focuses on the r...

Evaluation and analysis of liquid deicers for winter maintenance : final report.

DOT National Transportation Integrated Search

2017-09-01

The Ohio Department of Transportation (ODOT) uses mechanical and chemical methods to keep the roads safe during snow and ice events. Chemical solutions are available on the market to assist ODOT in preventing snow from bonding to the road surface as ...

30 CFR 817.150 - Roads: General.

Code of Federal Regulations, 2014 CFR

2014-07-01

... erosion, siltation, and the air pollution attendant to erosion, including road dust and dust occurring on other exposed surfaces, by measures such as vegetating, watering, using chemical or other dust... boundaries of units of the National Park System, the National Wildlife Refuge System, the National System of...

30 CFR 817.150 - Roads: General.

Code of Federal Regulations, 2012 CFR

2012-07-01

... erosion, siltation, and the air pollution attendant to erosion, including road dust and dust occurring on other exposed surfaces, by measures such as vegetating, watering, using chemical or other dust... boundaries of units of the National Park System, the National Wildlife Refuge System, the National System of...

30 CFR 817.150 - Roads: General.

Code of Federal Regulations, 2013 CFR

2013-07-01

... erosion, siltation, and the air pollution attendant to erosion, including road dust and dust occurring on other exposed surfaces, by measures such as vegetating, watering, using chemical or other dust... boundaries of units of the National Park System, the National Wildlife Refuge System, the National System of...

Detection of the local sliding in the tyre-road contact by measuring vibrations on the inner liner of the tyre

NASA Astrophysics Data System (ADS)

Niskanen, Arto J.; Tuononen, Ari J.

2017-04-01

Intelligent tyres can provide vital information from the tyre-road contact, especially for autonomous cars and intelligent infrastructure. In this paper, the acceleration measured on the inner liner of a tyre is used to detect the local sliding in the tyre-road contact. The Hilbert-Huang transform is utilized to extract the relevant vibration components and localize them in the wheel rotation angle domain. The energy of the vibration in the trailing part of the contact is shown to increase in low-friction conditions which can be related to the sliding of the tread part as a result of the shear stresses exceeding the local friction limit. To separate the effect of the surface roughness and the friction, different road surfaces were used in the measurements. In addition, the effects of different driving manoeuvres on the measured accelerations and the propagation of the sliding zone in the contact patch during braking are illustrated.

Damage assessment using advanced non-intrusive inspection methods: integration of space, UAV, GPR, and field spectroscopy

NASA Astrophysics Data System (ADS)

Themistocleous, Kyriacos; Neocleous, Kyriacos; Pilakoutas, Kypros; Hadjimitsis, Diofantos G.

2014-08-01

The predominant approach for conducting road condition surveys and analyses is still largely based on extensive field observations. However, visual assessment alone cannot identify the actual extent and severity of damage. New non-invasive and cost-effective non-destructive (NDT) remote sensing technologies can be used to monitor road pavements across their life cycle, including remotely sensed aerial and satellite visual and thermal image (AI) data, Unmanned Aerial Vehicles (UAVs), Spectroscopy and Ground Penetrating Radar (GRP). These non-contact techniques can be used to obtain surface and sub-surface information about damage in road pavements, including the crack depth, and in-depth structural failure. Thus, a smart and cost-effective methodology is required that integrates several of these non-destructive/ no-contact techniques for the damage assessment and monitoring at different levels. This paper presents an overview of how an integration of the above technologies can be used to conduct detailed road condition surveys. The proposed approach can also be used to predict the future needs for road maintenance; this information is proven to be valuable to a strategic decision making tools that optimizes maintenance based on resources and environmental issues.

Modelling heavy metals build-up on urban road surfaces for effective stormwater reuse strategy implementation.

PubMed

Hong, Nian; Zhu, Panfeng; Liu, An

2017-12-01

Urban road stormwater is an alternative water resource to mitigate water shortage issues in the worldwide. Heavy metals deposited (build-up) on urban road surface can enter road stormwater runoff, undermining stormwater reuse safety. As heavy metal build-up loads perform high variabilities in terms of spatial distribution and is strongly influenced by surrounding land uses, it is essential to develop an approach to identify hot-spots where stormwater runoff could include high heavy metal concentrations and hence cannot be reused if it is not properly treated. This study developed a robust modelling approach to estimating heavy metal build-up loads on urban roads using land use fractions (representing percentages of land uses within a given area) by an artificial neural network (ANN) model technique. Based on the modelling results, a series of heavy metal load spatial distribution maps and a comprehensive ecological risk map were generated. These maps provided a visualization platform to identify priority areas where the stormwater can be safely reused. Additionally, these maps can be utilized as an urban land use planning tool in the context of effective stormwater reuse strategy implementation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adsorption of heavy metals by road deposited solids.

PubMed

Gunawardana, Chandima; Goonetilleke, Ashantha; Egodawatta, Prasanna

2013-01-01

The research study discussed in the paper investigated the adsorption/desorption behaviour of heavy metals commonly deposited on urban road surfaces, namely, Zn, Cu, Cr and Pb, for different particle size ranges of solids. The study outcomes, based on field studies and batch experiments, confirmed that road deposited solids particles contain a significantly high amount of vacant charge sites with the potential to adsorb additional heavy metals. Kinetic studies and adsorption experiments indicated that Cr is the most preferred metal element to associate with solids due to the relatively high electronegativity and high charge density of trivalent cation (Cr(3+)). However, the relatively low availability of Cr in the urban road environment could influence this behaviour. Comparing total adsorbed metals present in solids particles, it was found that Zn has the highest capacity for adsorption to solids. Desorption experiments confirmed that a low concentration of Cu, Cr and Pb in solids was present in water-soluble and exchangeable form, whilst a significant fraction of adsorbed Zn has a high likelihood of being released back into solution. Among heavy metals, Zn is considered to be the most commonly available metal among road surface pollutants.

IMPERVIOUS SURFACE RESEARCH IN THE MID-ATLANTIC

EPA Science Inventory

Anthropogenic impervious surfaces have an important relationship with non-point source pollution (NPS) in urban watersheds. These human-created surfaces include such features as roads, parking lots, rooftops, sidewalks, and driveways. The amount of impervious surface area in a ...

Is conversion of a roadway from surfaced to un-surfaced for agency cost savings realistic? : [participant presentation].

DOT National Transportation Integrated Search

2012-08-01

This webinar is for TxDOT project 0-6677: Costs Associated with Conversion of Surfaced to Un-surfaced Roads. The topic is Is conversion of a roadway from surfaced to un-surfaced for agency cost savings realistic?.

Is conversion of a roadway from surfaced to un-surfaced for agency cost savings realistic? : [instructor presentation].

DOT National Transportation Integrated Search

2012-08-01

This webinar is for TxDOT project 0-6677: Costs Associated with Conversion of Surfaced to Un-surfaced Roads. The topic is Is conversion of a roadway from surfaced to un-surfaced for agency cost savings realistic?.

Untreated runoff quality from roof and road surfaces in a low intensity rainfall climate.

PubMed

Charters, Frances J; Cochrane, Thomas A; O'Sullivan, Aisling D

2016-04-15

Sediment and heavy metals in stormwater runoff are key pollutants of urban waterways, and their presence in stormwater is driven by climatic factors such as rainfall intensity. This study describes the total suspended solids (TSS) and heavy metal concentrations found in runoff from four different urban surfaces within a residential/institutional catchment, in a climate where rainfall is typically of low intensity (<5.1mm·h(-1)). The results were compared to untreated runoff quality from a compilation of international studies. The road runoff had the highest TSS concentrations, while copper and galvanized roof runoff had the highest copper and zinc concentrations, respectively. Pollutant concentrations were found to be significantly different between surfaces; quantification and prediction of pollutant contributions from urban surfaces should thus take account of the different surface materials, instead of being aggregated into more generalized categories such as land use. The TSS and heavy metal concentrations were found to be at the low to medium end of ranges observed internationally, except for total copper and zinc concentrations generated by dissolution of copper and galvanized roofing material respectively; these concentrations were at least as high as those reported internationally. TSS wash-off from the roofs was seen to be a source-limited process, where all available TSS is washed off during the rain event despite the low intensity rainfall, whereas both road TSS and heavy metals wash-off from roof and road surfaces appeared to all be transport-limited and therefore some carryover of pollutants occurs between rain events. A first flush effect was seen from most surfaces for TSS, but not for heavy metals. This study demonstrates that in low intensity rainfall climates, quantification of untreated runoff quality from key individual surface types in a catchment are needed to enable development of targeted and appropriately sized stormwater treatment systems. Copyright © 2016 Elsevier B.V. All rights reserved.

a Research on Monitoring Surface Deformation and Relationships with Surface Parameters in Qinghai Tibetan Plateau Permafrost

NASA Astrophysics Data System (ADS)

Mi, S. J.; Li, Y. T.; Wang, F.; Li, L.; Ge, Y.; Luo, L.; Zhang, C. L.; Chen, J. B.

2017-09-01

The Qinghai Tibetan Plateau permafrost has been the largest permafrost region in middle-low latitude in the world for its high altitude. For the large area permafrost, especially surface deformation brought by it, have serious influence on the road engineering, road maintaining and regional economic development. Consequently, it is essential to monitor the surface deformation and study factors that influent it. We monitored an area named Wudaoliang from July 25, 2015 to June 1, 2016 and 15 Sentinel images were obtained during this time. The area we chose is about 35 kilometers long and 2 kilometers wide, and the national road 109 of China passes through the area. The traditional PS-INSAR (Persistent Scatterer Interferometric Synthetic Aperture Radar) method is not suitable because less historical images in the research area and leading to the number of PS (Persistent Scatterer) points is not enough to obtain accurate deformation results. Therefore, in this paper, we used another method which named QUASI-PSInSAR (QUASI Persistent Scatterer Interferometric Synthetic Aperture Radar) to acquire deformation for it has the advantage to weaken or eliminate the effects of spatial and temporal correlation, which has proved by other scholar. After processing 15 images in the SARproz software, we got the conclusions that, 1) the biggest deformation velocity in the whole area was about 127.9mm/year and about 109.3 mm/year in the road; 2) apparent deformation which have surface deformation more than 30mm/year was about 1.7Km in the road. Meanwhile, soil moisture(SM), Land surface temperature (LST) and surface water(SW), which are primary parameters of the land surface over the same time were reversed by using Sentinel data, Landsat data and ZY-3 data, respectively. After analyzing SM, LST , SW and deformation, we obtained that wet areas which had bigger SM, lower LST and more SW, had greater percentage of severe deformation than arid areas; besides, deformation pattern were different in arid areas and wet areas. During the research time, frost heaving firstly accounted for a large proportion both in the arid and wet areas with the decrease of downward radiation from July to December; after December, thaw settlement came into prominence with the increase downward radiation in the arid areas, while in the wet areas, surface put into diverse situations because of water transformation leading to severe deformation. In summary, soil moisture is an important factor that influences the surface deformation. This relationship between deformation process and soil moisture will be researched more in our further work.

[Architectural ultrastructure of the human urinary transitional epithelium].

PubMed

Takayama, H; Konishi, T

1984-07-01

Human urinary bladder mucosa, confirmed to be normal by cystoscopic, histologic and bacteriologic examination, were obtained from four patients at prostatectomy and from two patients at an anti-VUR procedure. The luminal surface and the three dimensional architecture of the bladder mucosa were observed by scanning electron microscopy (SEM) after cryofracture of specimen and by transmission electron microscopy (TEM). The epithelium consists of superficial, intermediate and basal cells, and SEM and TEM showed that it was stratified. Intermediate cells reached the basal lamina by slender cytoplasmic processes but superficial cells were not directly in contact with the basal lamina. No pleomorphic or long microvilli were observed but short microvilli or granular protrusions were sparsely seen on the luminal surface of superficial cells. SEM of cryofractured surfaces revealed that cells from each cell layer were in contact with cellular junctions such as ridges, plicated projections and septum-like walls. Their junctions were more complicated with increasing depth of the cell layer. No pleomorphic or long microvilli were observed on any cell surface of the intermediate or basal cell layer. Under TEM, however, these junctional structures of ridges, plicated projections and septal walls appeared to be microvilli under TEM. Microvilli-like structures on TEM, therefore, have to be carefully distinguished from real microvilli. Careful observation is required when the presence of cells covered with microvilli is described as a sign of malignancy.

Application of conjugated heparin-albumin microparticles with laser-balloon angioplasty: a potential method for reducing adverse biologic reactivity after angioplasty

NASA Astrophysics Data System (ADS)

Kundu, Sourav K.; McMath, Linda P.; Zaidan, Jonathan T.; Spears, J. Richard

1991-05-01

Laser-balloon angioplasty (LBA) may potentially be used for local application of pharmacologically active agents which will reduce thrombogenic and proliferative responses after the angioplasty. In this study, the feasibility of applying covalently conjugated heparin- albumin microparticles onto arterial luminal surface was demonstrated. The covalent linkages were formed by reaction with 1-ethyl-3-dimethyl-aminopropyl-carbodiimide (EDC), and the resultant conjugates were used for preparation of microparticles by employing standard emulsification and heat-crosslinking techniques. The heparin release rate from the microparticles was found to be dependent upon the degree of crosslinking. When a thin coagulum of a suspension of microparticles was formed with heat on a glass surface, the treated surface demonstrated resistance to clot formation in contact with non-anticoagulated blood. A suspension of the microparticles applied during laser-balloon angioplasty onto the luminal surface of dog carotid and femoral arteries showed persistence for up to one week without thrombus formation or occlusion of the vessel. Since the rate of biodegradation is primarily dictated by the extent of crosslinking, an optimal degree of thermal denaturation will permit longer persistence of the carrier while allowing adequate release of the entrapped pharmacologic agent. A variety of antithrombotic and antiinflammatory agents are being considered as candidate bioprotective materials for local application after angioplasty.

Calculation comparison of an additive and subtractive light modulator for high-resolution pixellight headlamps

NASA Astrophysics Data System (ADS)

Held, Marcel Philipp; Ley, Peer-Phillip; Lachmayer, Roland

2018-02-01

High-resolution vehicle headlamps represent a future-oriented technology that increases traffic safety and driving comfort in the dark. A further development to current matrix beam headlamps are LED-based pixellight systems which enable additional lighting functions (e.g. the projection of navigation information on the road) to be activated for given driving scenarios. The image generation is based on spatial light modulators (SLM) such as digital micromirror devices (DMD), liquid crystal displays (LCD), liquid crystal on silicon (LCoS) devices or LED arrays. For DMD-, LCD- and LCoSbased headlamps, the optical system uses illumining optics to ensure a precise illumination of the corresponding SLM. LED arrays, however, have to use imaging optics to project the LED die onto an intermediate image plane and thus create the light distribution via an apposition of gapless juxtapositional LED die images. Nevertheless, the lambertian radiation characteristics complex the design of imaging optics regarding a highefficiency setup with maximum resolution and luminous flux. Simplifying the light source model and its emitting characteristics allows to determine a balanced setup between these parameters by using the Etendue and to ´ calculate the maximum possible efficacy and luminous flux for each technology in an early designing stage. Therefore, we present a calculation comparison of how simplifying the light source model can affect the Etendue ´ conservation and the setup design for two high-resolution technologies. The shown approach is evaluated and compared to simulation models to show the occurring deviation and its applicability.

A Mechanism of Intracellular P2X Receptor Activation*

PubMed Central

Sivaramakrishnan, Venketesh; Fountain, Samuel J.

2012-01-01

P2X receptors (P2XRs) are ATP-activated calcium-permeable ligand-gated ion channels traditionally viewed as sensors of extracellular ATP during diverse physiological processes including pain, inflammation, and taste. However, in addition to a cell surface residency P2XRs also populate the membranes of intracellular compartments, including mammalian lysosomes, phagosomes, and the contractile vacuole (CV) of the amoeba Dictyostelium. The function of intracellular P2XRs is unclear and represents a major gap in our understanding of ATP signaling. Here, we exploit the genetic versatility of Dictyostelium to investigate the effects of physiological concentrations of ATP on calcium signaling in isolated CVs. Within the CV, an acidic calcium store, P2XRs are orientated to sense luminal ATP. Application of ATP to isolated vacuoles leads to luminal translocation of ATP and release of calcium. Mechanisms of luminal ATP translocation and ATP-evoked calcium release share common pharmacology, suggesting that they are linked processes. The ability of ATP to mobilize stored calcium is reduced in vacuoles isolated from P2XAR knock-out amoeba and ablated in cells devoid of P2XRs. Pharmacological inhibition of luminal ATP translocation or depletion of CV calcium attenuates CV function in vivo, manifesting as a loss of regulatory cell volume decrease following osmotic swelling. We propose that intracellular P2XRs regulate vacuole activity by acting as calcium release channels, activated by translocation of ATP into the vacuole lumen. PMID:22736763

Tolerance to road salt deicers in chronically exposed urban pond communities

EPA Science Inventory

Freshwater salinization is a concern in urban aquatic ecosystems that receive road salt runoff from vast expanses of impervious surface cover. Our study was designed to evaluate the effects of chloride contamination on urban stormwater pond food webs and to assess the tolerance o...

22 CFR 121.4 - Ground vehicles.

Code of Federal Regulations, 2014 CFR

2014-04-01

... caliber); (2) Are armored support vehicles capable of off-road or amphibious use specially designed to... the definitions or control parameters regardless of the surface (e.g., highway, off-road, rail) upon...., different paint, repositioning of bolt holes), or that add parts or components otherwise available prior to...

30 CFR 816.150 - Roads: general.

Code of Federal Regulations, 2014 CFR

2014-07-01

... erosion, siltation, and the air pollution attendant to erosion, including road dust as well as dust occurring on other exposed surfaces, by measures such as vegetating, watering, using chemical or other dust... boundaries of units of the National Park System, the National Wildlife Refuge System, the National System of...

30 CFR 816.150 - Roads: general.

Code of Federal Regulations, 2012 CFR

2012-07-01

... erosion, siltation, and the air pollution attendant to erosion, including road dust as well as dust occurring on other exposed surfaces, by measures such as vegetating, watering, using chemical or other dust... boundaries of units of the National Park System, the National Wildlife Refuge System, the National System of...

30 CFR 816.150 - Roads: general.

Code of Federal Regulations, 2013 CFR

2013-07-01

... erosion, siltation, and the air pollution attendant to erosion, including road dust as well as dust occurring on other exposed surfaces, by measures such as vegetating, watering, using chemical or other dust... boundaries of units of the National Park System, the National Wildlife Refuge System, the National System of...

Forest soil erosion prediction as influenced by wildfire and roads

NASA Astrophysics Data System (ADS)

Cao, L.; Brooks, E. S.; Elliot, W.

2017-12-01

Following a wildfire, the risk of erosion is greatly increased. Forest road networks may change the underlying topography and alter natural flow paths. Flow accumulation and energy can be redistributed by roads and alter soil erosion processes. A LiDAR (Light Detection and Ranging) DEM makes it possible to quantify road topography, and estimate how roads influence surface runoff and sediment transport in a fire-disturbed watershed. With GIS technology and a soil erosion model, this study was carried out to evaluate the effect of roads on erosion and sediment yield following the Emerald Fire southwest of Lake Tahoe. The GeoWEPP model was used to estimate onsite erosion and offsite sediment delivery from each hillslope polygon and channel segment before and after fire disturbance in part of the burned area. The GeoWEPP flow path method was used to estimate the post-fire erosion rate of each GIS pixel. A 2-m resolution LiDAR DEM was used as the terrain layer. The Emerald Fire greatly increased onsite soil loss and sediment yields within the fire boundary. Following the fire, 78.71% of the burned area had predicted sediment yields greater than 4 Mg/ha/yr, compared to the preburn condition when 65.3% of the study area was estimated to generate a sediment yield less than 0.25 Mg/ha/yr. Roads had a remarkable influence on the flow path simulation and sub-catchments delineation, affecting sediment transport process spatially. Road segments acted as barriers that intercepted overland runoff and reduced downslope flow energy accumulation, therefore reducing onsite soil loss downslope of the road. Roads also changed the boundary of sub-catchment and defined new hydrological units. Road segments can transport sediment from one sub-catchment to another. This in turn leads to the redistribution of sediment and alters sediment yield for some sub-catchments. Culverts and road drain systems are of vital importance in rerouting runoff and sediment. Conservation structures can be installed to avoid sediment deposition or debris accumulation on the road surface. On the other hand, the outlets of culverts might be at a high risk of increasing downstream channel erosion due to the large amount of runoff. This implies that conservation measurements should be considered to control the runoff and sediment output from culverts.

Geomorphological aspects of road construction in a cold environment, Finland

NASA Astrophysics Data System (ADS)

Seppälä, Matti

1999-12-01

Traditionally, road alignments followed easy landscapes and suitable landforms. When traffic and the size and weight of vehicles increased and higher speeds were used, straighter roads were required; the easygoing relief could not always be used, and problems arose. Road contractors could save money in building and maintenance costs by considering the geomorphic facts. The examples from Finland document why road construction is very expensive in the conditions generated by severe winters. In Finland, more paved roads cross the Arctic Circle than in the whole of North America. This paper gives examples of geomorphic elements affecting road construction in a cold environment: eskers, drumlins, plains of late and postglacial glaciolacustrine and marine sediments, mires, steep rock cliffs, river channels and ice-dams, fluvial erosion, and palsas. Solutions to these problems include removal of frost sensible materials and replacement by more favorable sediments. Road surfaces, kept snow-free in the wintertime, are subjected to deep freezing. The maintenance of roads can be supported with some solutions that affect snowdrift and icing problems, avoidance of geomorphic factors that cause problems, and by using natural processes to help people. Some examples of how road construction affects geomorphic processes and vice versa are provided. For example, bridges block moving river ice, and on special occasions, road banks cause icing.

USEPA EPIC IMPERVIOUS SURFACE RESEARCH IN THE MID-ATLANTIC

EPA Science Inventory

Anthropogenic impervious surfaces have an important relationship with non-point source pollution (NPS) in urban watersheds. These human-created surfaces include such features as roads, parking lots, rooftops, sidewalks, and driveways. The amount of impervious surface area in a ...

Sealing is at the origin of rubber slipping on wet roads.

PubMed

Persson, B N J; Tartaglino, U; Albohr, O; Tosatti, E

2004-12-01

Loss of braking power and rubber skidding on a wet road is still an open physics problem, as neither the hydrodynamic effects nor the loss of surface adhesion that are sometimes blamed really manage to explain the 20-30% observed loss of low-speed tyre-road friction. Here we report a novel mechanism based on sealing of water-filled substrate pools by the rubber. The sealed-in water effectively smoothens the substrate, thus reducing the viscoelastic dissipation in bulk rubber induced by surface asperities-well established as a major friction contribution. Starting with the measured spectrum of asperities one can calculate the water-smoothened spectrum and from that the predicted friction reduction, which is of the correct magnitude. The theory is directly supported by fresh tyre-asphalt friction data.

Sealing is at the origin of rubber slipping on wet roads

NASA Astrophysics Data System (ADS)

Persson, B. N. J.; Tartaglino, U.; Albohr, O.; Tosatti, E.

2004-12-01

Loss of braking power and rubber skidding on a wet road is still an open physics problem, as neither the hydrodynamic effects nor the loss of surface adhesion that are sometimes blamed really manage to explain the 20-30% observed loss of low-speed tyre-road friction. Here we report a novel mechanism based on sealing of water-filled substrate pools by the rubber. The sealed-in water effectively smoothens the substrate, thus reducing the viscoelastic dissipation in bulk rubber induced by surface asperities-well established as a major friction contribution. Starting with the measured spectrum of asperities one can calculate the water-smoothened spectrum and from that the predicted friction reduction, which is of the correct magnitude. The theory is directly supported by fresh tyre-asphalt friction data.

Automatic 3D high-fidelity traffic interchange modeling using 2D road GIS data

NASA Astrophysics Data System (ADS)

Wang, Jie; Shen, Yuzhong

2011-03-01

3D road models are widely used in many computer applications such as racing games and driving simulations. However, almost all high-fidelity 3D road models were generated manually by professional artists at the expense of intensive labor. There are very few existing methods for automatically generating 3D high-fidelity road networks, especially for those existing in the real world. Real road network contains various elements such as road segments, road intersections and traffic interchanges. Among them, traffic interchanges present the most challenges to model due to their complexity and the lack of height information (vertical position) of traffic interchanges in existing road GIS data. This paper proposes a novel approach that can automatically produce 3D high-fidelity road network models, including traffic interchange models, from real 2D road GIS data that mainly contain road centerline information. The proposed method consists of several steps. The raw road GIS data are first preprocessed to extract road network topology, merge redundant links, and classify road types. Then overlapped points in the interchanges are detected and their elevations are determined based on a set of level estimation rules. Parametric representations of the road centerlines are then generated through link segmentation and fitting, and they have the advantages of arbitrary levels of detail with reduced memory usage. Finally a set of civil engineering rules for road design (e.g., cross slope, superelevation) are selected and used to generate realistic road surfaces. In addition to traffic interchange modeling, the proposed method also applies to other more general road elements. Preliminary results show that the proposed method is highly effective and useful in many applications.

Optimal policies for aggregate recycling from decommissioned forest roads.

PubMed

Thompson, Matthew; Sessions, John

2008-08-01

To mitigate the adverse environmental impact of forest roads, especially degradation of endangered salmonid habitat, many public and private land managers in the western United States are actively decommissioning roads where practical and affordable. Road decommissioning is associated with reduced long-term environmental impact. When decommissioning a road, it may be possible to recover some aggregate (crushed rock) from the road surface. Aggregate is used on many low volume forest roads to reduce wheel stresses transferred to the subgrade, reduce erosion, reduce maintenance costs, and improve driver comfort. Previous studies have demonstrated the potential for aggregate to be recovered and used elsewhere on the road network, at a reduced cost compared to purchasing aggregate from a quarry. This article investigates the potential for aggregate recycling to provide an economic incentive to decommission additional roads by reducing transport distance and aggregate procurement costs for other actively used roads. Decommissioning additional roads may, in turn, result in improved aquatic habitat. We present real-world examples of aggregate recycling and discuss the advantages of doing so. Further, we present mixed integer formulations to determine optimal levels of aggregate recycling under economic and environmental objectives. Tested on an example road network, incorporation of aggregate recycling demonstrates substantial cost-savings relative to a baseline scenario without recycling, increasing the likelihood of road decommissioning and reduced habitat degradation. We find that aggregate recycling can result in up to 24% in cost savings (economic objective) and up to 890% in additional length of roads decommissioned (environmental objective).

An evaluation of organic light emitting diode monitors for medical applications: Great timing, but luminance artifacts

PubMed Central

Elze, Tobias; Taylor, Christopher; Bex, Peter J.

2013-01-01

Purpose: In contrast to the dominant medical liquid crystal display (LCD) technology, organic light-emitting diode (OLED) monitors control the display luminance via separate light-emitting diodes for each pixel and are therefore supposed to overcome many previously documented temporal artifacts of medical LCDs. We assessed the temporal and luminance characteristics of the only currently available OLED monitor designed for use in the medical treatment field (SONY PVM2551MD) and checked the authors’ main findings with another SONY OLED device (PVM2541). Methods: Temporal properties of the photometric output were measured with an optical transient recorder. Luminances of the three color primaries and white for all 256 digital driving levels (DDLs) were measured with a spectroradiometer. Between the luminances of neighboring DDLs, just noticeable differences were calculated according to a perceptual model developed for medical displays. Luminances of full screen (FS) stimuli were compared to luminances of smaller stimuli with identical DDLs. Results: All measured luminance transition times were below 300 μs. Luminances were independent of the luminance in the preceding frame. However, for the single color primaries, up to 50.5% of the luminances of neighboring DDLs were not perceptually distinguishable. If two color primaries were active simultaneously, between 36.7% and 55.1% of neighboring luminances for increasing DDLs of the third primary were even decreasing. Moreover, luminance saturation effects were observed when too many pixels were active simultaneously. This effect was strongest for white; a small white patch was close to 400 cd/m2, but in FS the luminance of white saturated at 162 cd/m2. Due to different saturation levels, the luminance of FS green and FS yellow could exceed the luminance of FS white for identical DDLs. Conclusions: The OLED temporal characteristics are excellent and superior to those of LCDs. However, the OLEDs revealed severe perceptually relevant artifacts with implications for applicability to medical imaging. PMID:24007183

An evaluation of organic light emitting diode monitors for medical applications: great timing, but luminance artifacts.

PubMed

Elze, Tobias; Taylor, Christopher; Bex, Peter J

2013-09-01

In contrast to the dominant medical liquid crystal display (LCD) technology, organic light-emitting diode (OLED) monitors control the display luminance via separate light-emitting diodes for each pixel and are therefore supposed to overcome many previously documented temporal artifacts of medical LCDs. We assessed the temporal and luminance characteristics of the only currently available OLED monitor designed for use in the medical treatment field (SONY PVM2551MD) and checked the authors' main findings with another SONY OLED device (PVM2541). Temporal properties of the photometric output were measured with an optical transient recorder. Luminances of the three color primaries and white for all 256 digital driving levels (DDLs) were measured with a spectroradiometer. Between the luminances of neighboring DDLs, just noticeable differences were calculated according to a perceptual model developed for medical displays. Luminances of full screen (FS) stimuli were compared to luminances of smaller stimuli with identical DDLs. All measured luminance transition times were below 300 μs. Luminances were independent of the luminance in the preceding frame. However, for the single color primaries, up to 50.5% of the luminances of neighboring DDLs were not perceptually distinguishable. If two color primaries were active simultaneously, between 36.7% and 55.1% of neighboring luminances for increasing DDLs of the third primary were even decreasing. Moreover, luminance saturation effects were observed when too many pixels were active simultaneously. This effect was strongest for white; a small white patch was close to 400 cd/m(2), but in FS the luminance of white saturated at 162 cd/m(2). Due to different saturation levels, the luminance of FS green and FS yellow could exceed the luminance of FS white for identical DDLs. The OLED temporal characteristics are excellent and superior to those of LCDs. However, the OLEDs revealed severe perceptually relevant artifacts with implications for applicability to medical imaging.

Improving Multiple Surface Range Estimation of a 3-Dimensional FLASH LADAR in the Presence of Atmospheric Turbulence

DTIC Science & Technology

2013-06-01

during the design process. For instance, the detector could be calibrated with incoherent il- lumination and a separate calibration could be performed...Poisson dis- tribution is often employed as a statistical distribution for the detected images. How- ever, due to the highly coherent nature of laser

Plaque components affect wall stress in stented human carotid artery: A numerical study

NASA Astrophysics Data System (ADS)

Fan, Zhen-Min; Liu, Xiao; Du, Cheng-Fei; Sun, An-Qiang; Zhang, Nan; Fan, Zhan-Ming; Fan, Yu-Bo; Deng, Xiao-Yan

2016-12-01

Carotid artery stenting presents challenges of in-stent restenosis and late thrombosis, which are caused primarily by alterations in the mechanical environment of the artery after stent implantation. The present study constructed patient-specific carotid arterial bifurcation models with lipid pools and calcified components based on magnetic resonance imaging. We numerically analyzed the effects of multicomponent plaques on the distributions of von Mises stresses (VMSs) in the patient-specific models after stenting. The results showed that when a stent was deployed, the large soft lipid pool in atherosclerotic plaques cushioned the host artery and reduced the stress within the arterial wall; however, this resulted in a sharp increase of VMS in the fibrous cap. When compared with the lipid pool, the presence of the calcified components led to slightly increased stresses on the luminal surface. However, when a calcification was located close to the luminal surface of the host artery and the stenosis, the local VMS was elevated. Overall, compared with calcified components, large lipid pools severely damaged the host artery after stenting. Furthermore, damage due to the calcified component may depend on location.

Cdc42 and formin activity control non-muscle myosin dynamics during Drosophila heart morphogenesis

PubMed Central

Vogler, Georg; Liu, Jiandong; Iafe, Timothy W.; Migh, Ede; Mihály, József

2014-01-01

During heart formation, a network of transcription factors and signaling pathways guide cardiac cell fate and differentiation, but the genetic mechanisms orchestrating heart assembly and lumen formation remain unclear. Here, we show that the small GTPase Cdc42 is essential for Drosophila melanogaster heart morphogenesis and lumen formation. Cdc42 genetically interacts with the cardiogenic transcription factor tinman; with dDAAM which belongs to the family of actin organizing formins; and with zipper, which encodes nonmuscle myosin II. Zipper is required for heart lumen formation, and its spatiotemporal activity at the prospective luminal surface is controlled by Cdc42. Heart-specific expression of activated Cdc42, or the regulatory formins dDAAM and Diaphanous caused mislocalization of Zipper and induced ectopic heart lumina, as characterized by luminal markers such as the extracellular matrix protein Slit. Placement of Slit at the lumen surface depends on Cdc42 and formin function. Thus, Cdc42 and formins play pivotal roles in heart lumen formation through the spatiotemporal regulation of the actomyosin network. PMID:25267295

Locally available aggregate and sediment production

Treesearch

Randy B. Foltz; Mark Truebe

2003-01-01

Selection of suitable locally available materials to build strong and durable roads with aggregate surfaces is desired to minimize road construction and maintenance costs and to minimize the detrimental effects of sedimentation. Eighteen aggregates were selected from local sources in Idaho, Oregon, South Dakota, and Washington State. Aggregate was placed in shallow...

Implementation of low temperature tests for asphalt mixtures to improve the longevity of road surfaces.

DOT National Transportation Integrated Search

2013-12-01

Field samples were obtained from cores taken from multiple roads around the Salt Lake Valley in Utah and prepared for BBR testing. The response of field cores showed that even though the same binder grade used in the region was the same, the resultin...

Stabilization techniques for reactive aggregate in soil-cement base course.

DOT National Transportation Integrated Search

2003-01-01

Anhydrite (CaSO4) beds occur as a cap rock on a salt dome in Winn Parish in north Louisiana. Locally known as Winn Rock, it has been quarried for gravel for road building. It has been used as a surface course for local parish and logging roads. Stabi...

36 CFR 1004.11 - Load, weight and size limits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... apply to a vehicle operated on a Presidio Trust road. However, the Board may designate more restrictive limits when appropriate for traffic safety or protection of the road surface. The Board may require a.... 1004.11 Section 1004.11 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY...

The influence of road salts on water quality in a restored urban stream (Columbus, OH)

EPA Science Inventory

Understanding the connection between road salts and water quality is essential to assess the implications for human health and ecosystem services. To assess the effects of the restoration on water quality, surface and ground water have been monitored at Minebank Run, MD since 20...

Luminous Blue Compact Galaxies: Probes of galaxy assembly

NASA Astrophysics Data System (ADS)

Newton, Cassidy Louann

The life cycles of galaxies over cosmic time is yet to be fully understood. How did galaxies evolve from their formative stages to the structures we observe today? This dissertation details the identification and analysis of a sample of Luminous Blue Compact Galaxies (LBCGs), a class of galaxy in the local (z < 0.05) universe exhibiting blue colors, high surface brightness, and high star formation rates. These systems appear to be very similar in their global properties to the early evolutionary phases of most galaxies, however their locality permits detailed investigation over a broad range of the electromagnetic spectrum in contrast to the smaller angular sizes and extreme faintness of distant galaxies. We use a combination of optical, ultraviolet, and infrared data to investigate a sample of LBCGs utilizing space and ground-based data.

Color Discrimination Is Affected by Modulation of Luminance Noise in Pseudoisochromatic Stimuli

PubMed Central

Cormenzana Méndez, Iñaki; Martín, Andrés; Charmichael, Teaire L.; Jacob, Mellina M.; Lacerda, Eliza M. C. B.; Gomes, Bruno D.; Fitzgerald, Malinda E. C.; Ventura, Dora F.; Silveira, Luiz C. L.; O'Donell, Beatriz M.; Souza, Givago S.

2016-01-01

Pseudoisochromatic stimuli have been widely used to evaluate color discrimination and to identify color vision deficits. Luminance noise is one of the stimulus parameters used to ensure that subject's response is due to their ability to discriminate target stimulus from the background based solely on the hue between the colors that compose such stimuli. We studied the influence of contrast modulation of the stimulus luminance noise on threshold and reaction time color discrimination. We evaluated color discrimination thresholds using the Cambridge Color Test (CCT) at six different stimulus mean luminances. Each mean luminance condition was tested using two protocols: constant absolute difference between maximum and minimum luminance of the luminance noise (constant delta protocol, CDP), and constant contrast modulation of the luminance noise (constant contrast protocol, CCP). MacAdam ellipses were fitted to the color discrimination thresholds in the CIE 1976 color space to quantify the color discrimination ellipses at threshold level. The same CDP and CCP protocols were applied in the experiment measuring RTs at three levels of stimulus mean luminance. The color threshold measurements show that for the CDP, ellipse areas decreased as a function of the mean luminance and they were significantly larger at the two lowest mean luminances, 10 cd/m2 and 13 cd/m2, compared to the highest one, 25 cd/m2. For the CCP, the ellipses areas also decreased as a function of the mean luminance, but there was no significant difference between ellipses areas estimated at six stimulus mean luminances. The exponent of the decrease of ellipse areas as a function of stimulus mean luminance was steeper in the CDP than CCP. Further, reaction time increased linearly with the reciprocal of the length of the chromatic vectors varying along the four chromatic half-axes. It decreased as a function of stimulus mean luminance in the CDP but not in the CCP. The findings indicated that visual performance using pseudoisochromatic stimuli was dependent on the Weber's contrast of the luminance noise. Low Weber's contrast in the luminance noise is suggested to have a reduced effect on chromatic information and, hence, facilitate desegregation of the hue-defined target from the background. PMID:27458404

Numerical study of the thermal behavior of a new deicing road structure design with energy harvesting capabilities

NASA Astrophysics Data System (ADS)

Le Touz, Nicolas; Dumoulin, Jean

2015-04-01

Facing the heavy organisational, financial and environmental constraints imposed by usual winter maintenance salting operations, pavement engineers have been led to look for alternative solutions to avoid ice or snow deposit at pavements surface. Among the solutions, one is self-de-icing heating pavements, for which two technologies have been developed so far: one is based on embedded coils circulating a heated calorific fluid under the pavement surface; the other one relies on the use of embedded resistant electric wires. The use and operation of such systems in the world is still limited and was only confined to small road stretches or specific applications, such as bridges which are particularly sensitive to frost. One of the most significant "coil technology" example in Europe is the SERSO-System (Solar Energy recovery from road surfaces) built in 1994, on a Switzerland bridge. Many of these experiences are referenced in the technical literature, which provides state-of-the art papers (see for instance Eugster) and useful detailed information dealing with the construction and operational management of such installation. The present study is taking part of the Forever Open Road Concept addressed by the R5G: 5th Generation Road [1], one of the major project supported by IFSTTAR. It considers a different design of self-de-icing road that simplify its mode of construction and maintenance, compared to the two technologies mentioned above. It should also be noted that similar to pavements instrumented with coils, such structure could be used in the reversible way to capture the solar energy at the pavement surface during sunny days and store it, to either warm the pavement at a later stage or for exogenous needs (e.g. contribution to domestic hot water). To complete our study we also considered the use of semi-transparent pavement course wearing in place of the traditional opaque one. In the present study, a 2D model was developed using FEM approach. It combines 2 numerical models. One is dedicated to the calculation of the heat transfer inside the porous layer between the fluid and the structure according to the geometry studied and the physical properties of the components of the system. The second one addresses the heat transfer inside the different layer of the pavement and was adapted to allow the insertion of a semi-transparent surface layer (for sun radiation). The temperature spatial distribution within the structure and its surface is calculated at different time step according to the evolution of boundary conditions at its surface. Various location in France were selected and calculation of the temperature field was carried-out over a year. Discussion on the performances of such system versus its location is proposed. Influence of a semi-transparent layer is also discussed. Future works will compared numerical simulations with experiments thank to a dedicated test bench under development and that will allow to test various structure in parallel. References [1] W. J. Eugster, Road and Bridge Heating Geothermal Energy. Overview and examples, European Geothermal Congress 2007 [2] http://www.ifsttar.fr/en/recherche-expertise/colonne-1/nos-grands-projets/r5g-5th-generation-road/

Potential Impacts from Using Photoactive Roads as AN Air Quality Mitigation Strategy

NASA Astrophysics Data System (ADS)

Toro, C.; Jobson, B. T.; Shen, S.; Chung, S. H.; Haselbach, L.

2013-12-01

Mobile sources are major contributors to photochemical air pollution in urban areas. It has been proposed that the use of TiO2 coated roadways ('photoactive roads') could be an effective approach to reduce mobile source emissions by oxidizing NOx and VOC emissions at the roadway surface. However, studies have shown that formation of HONO and aldehydes can occur from some TiO2 treated surfaces during the photocatalytic oxidation of NOx and VOC, respectively. By changing the NOx-to-VOC ratio and generating photolabile HOx radical precursors, photoactive roads may enhance ozone formation rates in urban areas. In this work we present results that quantify NOx and VOC loss rates onto TiO2 treated asphalt and concrete samples, as well as HONO and aldehydes yields that result from the photocatalytic process. The treatment used a commercially available product. These objectives are relevant considering that the quantification of pollutant loss rates and yields of byproducts have not been determined for asphalt and that in the US more than 90% of the roadway surface is made of this material. Surface reaction probabilities (γ) and byproduct yields were determined using a CSTR photochemical chamber under varying conditions of water vapor and UV-A light intensity. Our results indicate that asphalt surfaces have a significantly higher molar yield of HONO compared to concrete surfaces with similar TiO2 loading. Concrete surfaces have reaction probabilities with NO one order of magnitude higher than asphalt samples. Fresh asphalt samples showed negligible photocatalytic activity, presumably due to absorption of TiO2 into the bitumen substrate. Laboratory-prepared asphalt samples with a higher degree of exposed aggregates showed increased HONO molar yields when compared to real-road asphalt samples, whose HONO molar yield was ~1%. Preliminary results for aldehydes formation showed similar molar yields between aged asphalt and concrete, even though aged asphalt samples had twice the TiO2 loading than concrete samples.

Interpreting stream sediment fingerprints against primary and secondary source signatures in agricultural catchments

NASA Astrophysics Data System (ADS)

Blake, Will H.; Haley, Steve; Smith, Hugh G.; Taylor, Alex; Goddard, Rupert; Lewin, Sean; Fraser, David

2013-04-01

Many sediment fingerprinting studies adopt a black box approach to source apportionment whereby the properties of downstream sediment are compared quantitatively to the geochemical fingerprints of potential catchment sources without consideration of potential signature development or modification during transit. Working within a source-pathway-receptor framework, this study aimed to undertake sediment source apportionment within 6 subcatchments of an agricultural river basin with specific attention to the potential role of contaminants (vehicle emissions and mine waste) in development of stream sediment signatures. Fallout radionuclide (FRN) and geochemical fingerprinting methods were adopted independently to establish source signatures for primary sediment sources of surface and subsurface soil materials under various land uses plus reworked mine and 'secondary' soil material deposited, in transit, along road networks. FRN data demonstrated expected variability between surface soil (137Cs = 14 ± 3 Bq kg-1; 210Pbxs = 40 ± 7 Bq kg-1) and channel bank materials (137Cs = 3 ± 1 Bq kg-1; 210Pbxs = 24 ± 5 Bq kg-1) but road transported soil material was considerably elevated in 210Pbxs (up to 673 ± 51 Bq kg-1) due to sediment interaction with pluvial surface water within the road network. Geochemical discrimination between surface and subsurface soil materials was dominated by alkaline earth and alkali metals e.g. Ba, Rb, Ca, K, Mg which are sensitive to weathering processes in soil. Magnetic susceptibility and heavy metals were important discriminators of road transported material which demonstrated transformation of the signatures of material transported via the road network. Numerical unmixing of stream sediment indicated that alongside channel bank erosion, road transported material was an important component in some systems in accord with FRN evidence. While mining spoil also ranked as a significant source in an affected catchment, perhaps related to legacy sediment, the potential role of dissolved metal leaching and subsequent sediment-water interaction within the channel on signature modification remained unclear. Consideration of sediment signature modification en route from primary source to stream elucidated important information regarding sediment transfer pathways and dynamics relevant to sediment management decisions. Further work on sediment-water interactions and potential for signature transformation in the channel environment is required.

Estimating the extent of impervious surfaces and turf grass across large regions

USGS Publications Warehouse

Claggett, Peter; Irani, Frederick M.; Thompson, Renee L.

2013-01-01

The ability of researchers to accurately assess the extent of impervious and pervious developed surfaces, e.g., turf grass, using land-cover data derived from Landsat satellite imagery in the Chesapeake Bay watershed is limited due to the resolution of the data and systematic discrepancies between developed land-cover classes, surface mines, forests, and farmlands. Estimates of impervious surface and turf grass area in the Mid-Atlantic, United States that were based on 2006 Landsat-derived land-cover data were substantially lower than estimates based on more authoritative and independent sources. New estimates of impervious surfaces and turf grass area derived using land-cover data combined with ancillary information on roads, housing units, surface mines, and sampled estimates of road width and residential impervious area were up to 57 and 45% higher than estimates based strictly on land-cover data. These new estimates closely approximate estimates derived from authoritative and independent sources in developed counties.

Binocular combination of luminance profiles

PubMed Central

Ding, Jian; Levi, Dennis M.

2017-01-01

We develop and test a new two-dimensional model for binocular combination of the two eyes' luminance profiles. For first-order stimuli, the model assumes that one eye's luminance profile first goes through a luminance compressor, receives gain-control and gain-enhancement from the other eye, and then linearly combines the other eye's output profile. For second-order stimuli, rectification is added in the signal path of the model before the binocular combination site. Both the total contrast and luminance energies, weighted sums over both the space and spatial-frequency domains, were used in the interocular gain-control, while only the total contrast energy was used in the interocular gain-enhancement. To challenge the model, we performed a binocular brightness matching experiment over a large range of background and target luminances. The target stimulus was a dichoptic disc with a sharp edge that has an increment or decrement luminance from its background. The disk's interocular luminance ratio varied from trial to trial. To refine the model we tested three luminance compressors, five nested binocular combination models (including the Ding–Sperling and the DSKL models), and examined the presence or absence of total luminance energy in the model. We found that (1) installing a luminance compressor, either a logarithmic luminance function or luminance gain-control, (2) including both contrast and luminance energies, and (3) adding interocular gain-enhancement (the DSKL model) to a combined model significantly improved its performance. The combined model provides a systematic account of binocular luminance summation over a large range of luminance input levels. It gives a unified explanation of Fechner's paradox observed on a dark background, and a winner-take-all phenomenon observed on a light background. To further test the model, we conducted two additional experiments: luminance summation of discs with asymmetric contour information (Experiment 2), similar to Levelt (1965) and binocular combination of second-order contrast-modulated gratings (Experiment 3). We used the model obtained in Experiment 1 to predict the results of Experiments 2 and 3 and the results of our previous studies. Model simulations further refined the contrast space weight and contrast sensitivity functions that are installed in the model, and provide a reasonable account for rebalancing of imbalanced binocular vision by reducing the mean luminance in the dominant eye. PMID:29098293

Reverse radiance: a fast accurate method for determining luminance

NASA Astrophysics Data System (ADS)

Moore, Kenneth E.; Rykowski, Ronald F.; Gangadhara, Sanjay

2012-10-01

Reverse ray tracing from a region of interest backward to the source has long been proposed as an efficient method of determining luminous flux. The idea is to trace rays only from where the final flux needs to be known back to the source, rather than tracing in the forward direction from the source outward to see where the light goes. Once the reverse ray reaches the source, the radiance the equivalent forward ray would have represented is determined and the resulting flux computed. Although reverse ray tracing is conceptually simple, the method critically depends upon an accurate source model in both the near and far field. An overly simplified source model, such as an ideal Lambertian surface substantially detracts from the accuracy and thus benefit of the method. This paper will introduce an improved method of reverse ray tracing that we call Reverse Radiance that avoids assumptions about the source properties. The new method uses measured data from a Source Imaging Goniometer (SIG) that simultaneously measures near and far field luminous data. Incorporating this data into a fast reverse ray tracing integration method yields fast, accurate data for a wide variety of illumination problems.

Color constancy in a scene with bright colors that do not have a fully natural surface appearance.

PubMed

Fukuda, Kazuho; Uchikawa, Keiji

2014-04-01

Theoretical and experimental approaches have proposed that color constancy involves a correction related to some average of stimulation over the scene, and some of the studies showed that the average gives greater weight to surrounding bright colors. However, in a natural scene, high-luminance elements do not necessarily carry information about the scene illuminant when the luminance is too high for it to appear as a natural object color. The question is how a surrounding color's appearance mode influences its contribution to the degree of color constancy. Here the stimuli were simple geometric patterns, and the luminance of surrounding colors was tested over the range beyond the luminosity threshold. Observers performed perceptual achromatic setting on the test patch in order to measure the degree of color constancy and evaluated the surrounding bright colors' appearance mode. Broadly, our results support the assumption that the visual system counts only the colors in the object-color appearance for color constancy. However, detailed analysis indicated that surrounding colors without a fully natural object-color appearance had some sort of influence on color constancy. Consideration of this contribution of unnatural object color might be important for precise modeling of human color constancy.

Micromachined edge illuminated optically transparent automotive light guide panels

NASA Astrophysics Data System (ADS)

Ronny, Rahima Afrose; Knopf, George K.; Bordatchev, Evgueni; Tauhiduzzaman, Mohammed; Nikumb, Suwas

2012-03-01

Edge-lit backlighting has been used extensively for a variety of small and medium-sized liquid crystal displays (LCDs). The shape, density and spatial distribution pattern of the micro-optical elements imprinted on the surface of the flat light-guide panel (LGP) are often "optimized" to improve the overall brightness and luminance uniformity. A similar concept can be used to develop interior convenience lighting panels and exterior tail lamps for automotive applications. However, costly diffusive sheeting and brightness enhancement films are not be considered for these applications because absolute luminance uniformity and the minimization of Moiré fringe effects are not significant factors in assessing quality of automotive lighting. A new design concept that involves micromilling cylindrical micro-optical elements on optically transparent plastic substrates is described in this paper. The variable parameter that controls illumination over the active regions of the panel is the depth of the individual cylindrical micro-optical elements. LightTools™ is the optical simulation tool used to explore how changing the micro-optical element depth can alter the local and global luminance. Numerical simulation and microfabrication experiments are performed on several (100mmx100mmx6mm) polymethylmethacrylate (PMMA) test samples in order to verify the illumination behavior.

Genome-wide Search of Oncogenic Pathways Cooperating with ETS Fusions in Prostate Cancer

DTIC Science & Technology

2013-07-01

luminal cells cannot engraft well in this assay), and although both luminal and basal cells could serve as cells of origin of prostate cancer, luminal ...was the need for them to differentiate into luminal cells first [27]. Thus, it appears that prostate luminal cells may serve as the major cellular...origin for prostate cancer. We therefore more favor a strategy to search for ETS-cooperating mutations in prostate luminal cells. Furthermore

An Efficient Method for Automatic Road Extraction Based on Multiple Features from LiDAR Data

NASA Astrophysics Data System (ADS)

Li, Y.; Hu, X.; Guan, H.; Liu, P.

2016-06-01

The road extraction in urban areas is difficult task due to the complicated patterns and many contextual objects. LiDAR data directly provides three dimensional (3D) points with less occlusions and smaller shadows. The elevation information and surface roughness are distinguishing features to separate roads. However, LiDAR data has some disadvantages are not beneficial to object extraction, such as the irregular distribution of point clouds and lack of clear edges of roads. For these problems, this paper proposes an automatic road centerlines extraction method which has three major steps: (1) road center point detection based on multiple feature spatial clustering for separating road points from ground points, (2) local principal component analysis with least squares fitting for extracting the primitives of road centerlines, and (3) hierarchical grouping for connecting primitives into complete roads network. Compared with MTH (consist of Mean shift algorithm, Tensor voting, and Hough transform) proposed in our previous article, this method greatly reduced the computational cost. To evaluate the proposed method, the Vaihingen data set, a benchmark testing data provided by ISPRS for "Urban Classification and 3D Building Reconstruction" project, was selected. The experimental results show that our method achieve the same performance by less time in road extraction using LiDAR data.

Laser Scanning on Road Pavements: A New Approach for Characterizing Surface Texture

PubMed Central

Bitelli, Gabriele; Simone, Andrea; Girardi, Fabrizio; Lantieri, Claudio

2012-01-01

The surface layer of road pavement has a particular importance in relation to the satisfaction of the primary demands of locomotion, such as security and eco-compatibility. Among those pavement surface characteristics, the “texture” appears to be one of the most interesting with regard to the attainment of skid resistance. Specifications and regulations, providing a wide range of functional indicators, act as guidelines to satisfy the performance requirements. This paper describes an experiment on the use of laser scanner techniques on various types of asphalt for texture characterization. The use of high precision laser scanners, such as the triangulation types, is proposed to expand the analysis of road pavement from the commonly and currently used two-dimensional method to a three-dimensional one, with the aim of extending the range of the most important parameters for these kinds of applications. Laser scanners can be used in an innovative way to obtain information on areal surface layer through a single measurement, with data homogeneity and representativeness. The described experience highlights how the laser scanner is used for both laboratory experiments and tests in situ, with a particular attention paid to factors that could potentially affect the survey. PMID:23012535

Influence of Spatial and Chromatic Noise on Luminance Discrimination.

PubMed

Miquilini, Leticia; Walker, Natalie A; Odigie, Erika A; Guimarães, Diego Leite; Salomão, Railson Cruz; Lacerda, Eliza Maria Costa Brito; Cortes, Maria Izabel Tentes; de Lima Silveira, Luiz Carlos; Fitzgerald, Malinda E C; Ventura, Dora Fix; Souza, Givago Silva

2017-12-05

Pseudoisochromatic figures are designed to base discrimination of a chromatic target from a background solely on the chromatic differences. This is accomplished by the introduction of luminance and spatial noise thereby eliminating these two dimensions as cues. The inverse rationale could also be applied to luminance discrimination, if spatial and chromatic noise are used to mask those cues. In this current study estimate of luminance contrast thresholds were conducted using a novel stimulus, based on the use of chromatic and spatial noise to mask the use of these cues in a luminance discrimination task. This was accomplished by presenting stimuli composed of a mosaic of circles colored randomly. A Landolt-C target differed from the background only by the luminance. The luminance contrast thresholds were estimated for different chromatic noise saturation conditions and compared to luminance contrast thresholds estimated using the same target in a non-mosaic stimulus. Moreover, the influence of the chromatic content in the noise on the luminance contrast threshold was also investigated. Luminance contrast threshold was dependent on the chromaticity noise strength. It was 10-fold higher than thresholds estimated from non-mosaic stimulus, but they were independent of colour space location in which the noise was modulated. The present study introduces a new method to investigate luminance vision intended for both basic science and clinical applications.

Luminous bacteria cultured from fish guts in the Gulf of Oman.

PubMed

Makemson, J C; Hermosa, G V

1999-01-01

The incidence of culturable luminous bacteria in Omani market fish guts was correlated to habitat type amongst 109 species of fish. Isolated representative luminous bacteria were compared to known species using the Biolog system (95 traits/isolate) and cluster analysis, which showed that the main taxa present in fish guts were clades related to Vibrio harveyi and Photobacterium species with sporadic incidence of P. phosphoreum. The luminous isolates from gut of the slip-mouth (barred pony fish), Leiognathus fasciatus, were mainly a type related to Photobacterium but phenotypically different from known species. These luminous gut bacteria were identical with the bacteria in the light organ, indicating that the light organ supplies a significant quantity of luminous bacteria to the gut. In many of the fish that lack light organs, luminous bacteria were also the dominant bacterial type in the gut, while in some others luminous bacteria were encountered sporadically and at low densities, reflecting the incidence of culturable luminous bacteria in seawater. Pelagic fish contained the highest incidence of culturable luminous bacteria and reef-associated fish the lowest. No correlation was found between the incidence of culturable luminous bacteria and the degree to which fish produce a melanin-covered gut. Copyright 1999 John Wiley & Sons, Ltd.

Characterizing a porous road pavement using surface impedance measurement: a guided numerical inversion procedure.

PubMed

Benoit, Gaëlle; Heinkélé, Christophe; Gourdon, Emmanuel

2013-12-01

This paper deals with a numerical procedure to identify the acoustical parameters of road pavement from surface impedance measurements. This procedure comprises three steps. First, a suitable equivalent fluid model for the acoustical properties porous media is chosen, the variation ranges for the model parameters are set, and a sensitivity analysis for this model is performed. Second, this model is used in the parameter inversion process, which is performed with simulated annealing in a selected frequency range. Third, the sensitivity analysis and inversion process are repeated to estimate each parameter in turn. This approach is tested on data obtained for porous bituminous concrete and using the Zwikker and Kosten equivalent fluid model. This work provides a good foundation for the development of non-destructive in situ methods for the acoustical characterization of road pavements.

Tyre contact length on dry and wet road surfaces measured by three-axial accelerometer

NASA Astrophysics Data System (ADS)

Matilainen, Mika; Tuononen, Ari

2015-02-01

We determined the tyre contact length on dry and wet roads by measuring the accelerations of the inner liner with a three-axial accelerometer. The influence of the tyre pressure, driving velocity, and tread depth on the contact length was studied in both types of road surface conditions. On dry asphalt the contact length was almost constant, regardless of the driving velocity. On wet asphalt the presence of water could be detected even at low driving velocities (e.g. 20 km/h for a worn tyre) as the contact length began to decrease from that found in the dry asphalt situation. In addition to improving the performance of active safety systems and driver warning systems, the contact length information could be beneficial for classifying and studying the aquaplaning behaviour of tyres.

Life cycle assessment of disposal of residues from municipal solid waste incineration: recycling of bottom ash in road construction or landfilling in Denmark evaluated in the ROAD-RES model.

PubMed

Birgisdóttir, H; Bhander, G; Hauschild, M Z; Christensen, T H

2007-01-01

Two disposal methods for MSWI bottom ash were assessed in a new life cycle assessment (LCA) model for road construction and disposal of residues. The two scenarios evaluated in the model were: (i) landfilling of bottom ash in a coastal landfill in Denmark and (ii) recycling of bottom ash as subbase layer in an asphalted secondary road. The LCA included resource and energy consumption, and emissions associated with upgrading of bottom ash, transport, landfilling processes, incorporation of bottom ash in road, substitution of natural gravel as road construction material and leaching of heavy metals and salts from bottom ash in road as well as in landfill. Environmental impacts associated with emissions to air, fresh surface water, marine surface water, groundwater and soil were aggregated into 12 environmental impact categories: Global Warming, Photochemical Ozone Formation, Nutrient Enrichment, Acidification, Stratospheric Ozone Depletion, Human Toxicity via air/water/soil, Ecotoxicity in water/soil, and a new impact category, Stored Ecotoxicity to water/soil that accounts for the presence of heavy metals and very persistent organic compounds that in the long-term might leach. Leaching of heavy metals and salts from bottom ash was estimated from a series of laboratory leaching tests. For both scenarios, Ecotoxicity(water) was, when evaluated for the first 100 yr, the most important among the twelve impact categories involved in the assessment. Human Toxicity(soil) was also important, especially for the Road scenario. When the long-term leaching of heavy metals from bottom ash was evaluated, based on the total content of heavy metals in bottom ash, all impact categories became negligible compared to the potential Stored Ecotoxicity, which was two orders of magnitudes greater than Ecotoxicity(water). Copper was the constituent that gave the strongest contributions to the ecotoxicities. The most important resources consumed were clay as liner in landfill and the groundwater resource which was potentially spoiled due to leaching of salts from bottom ash in road. The difference in environmental impacts between landfilling and utilization of bottom ash in road was marginal when these alternatives were assessed in a life cycle perspective.

Use of chemical soil additives to stabilize off-road vehicle trails

Treesearch

J.N. Davis; J.E. Baier; J.P. Fulton; D.A. Brown; T.P. McDonald

2007-01-01

Off‐road vehicle (ORV) use is an increasingly popular form of outdoor recreation throughout the United States. This form of motorized recreation, however, can sometimes lead to serious erosion of trail running surfaces, with resulting export of sediment into forested ecosystems causing environmental degradation. This project was conducted to determine the...

32 CFR 935.136 - General operating rules.

Code of Federal Regulations, 2010 CFR

2010-07-01

... unposted area, except adjacent to the right-hand curb or edge of the road; (k) Park a motor vehicle in a... compacted surface; (n) Operate any motor vehicle contrary to a posted traffic sign; (o) Operate a motor... vehicle off of established roads, or in a cross-country manner, except when necessary in conducting...

32 CFR 935.136 - General operating rules.

Code of Federal Regulations, 2011 CFR

2011-07-01

... unposted area, except adjacent to the right-hand curb or edge of the road; (k) Park a motor vehicle in a... compacted surface; (n) Operate any motor vehicle contrary to a posted traffic sign; (o) Operate a motor... vehicle off of established roads, or in a cross-country manner, except when necessary in conducting...

32 CFR 935.136 - General operating rules.

Code of Federal Regulations, 2012 CFR

2012-07-01

... unposted area, except adjacent to the right-hand curb or edge of the road; (k) Park a motor vehicle in a... compacted surface; (n) Operate any motor vehicle contrary to a posted traffic sign; (o) Operate a motor... vehicle off of established roads, or in a cross-country manner, except when necessary in conducting...

32 CFR 935.136 - General operating rules.

Code of Federal Regulations, 2014 CFR

2014-07-01

... unposted area, except adjacent to the right-hand curb or edge of the road; (k) Park a motor vehicle in a... compacted surface; (n) Operate any motor vehicle contrary to a posted traffic sign; (o) Operate a motor... vehicle off of established roads, or in a cross-country manner, except when necessary in conducting...

32 CFR 935.136 - General operating rules.

Code of Federal Regulations, 2013 CFR

2013-07-01

... unposted area, except adjacent to the right-hand curb or edge of the road; (k) Park a motor vehicle in a... compacted surface; (n) Operate any motor vehicle contrary to a posted traffic sign; (o) Operate a motor... vehicle off of established roads, or in a cross-country manner, except when necessary in conducting...

Surface properties-vehicle interaction

NASA Astrophysics Data System (ADS)

Huft, D. L.; Her, I.; Agrawal, S. K.; Zimmer, R. A.; Bester, C. J.

Several topics related to the surface properties of aircraft runways are discussed. The South Dakota profilometer; development of a data acquisition method for noncontact pavement macrotexture measurement; the traction of an aircraft tire on grooved and porous asphaltic concrete; holes in the pavements; the effect of pavement type and condition on the fuel consumption of vehicles; the traction loss of a suspended tire on a sinusoidal road; the effect of vehicle and driver characteristics on the psychological evaluation of road roughness; the correlation of subjective panel ratings of pavement ride quality with profilometer-derived measures of pavement roughness; a microprocessor-based noncontact distance measuring control system, and, the representation of pavement surface topography in predicting runoff depths and hydroplaning potential are discussed.

Indirect diagnosis of pavement structural damages using surface GPR reflection techniques

NASA Astrophysics Data System (ADS)

Benedetto, A.; Pensa, S.

2007-06-01

The safety and operability of road networks is, in part, dependent on the quality of the pavement. It is known that pavements suffer from many different structural problems which can lead to damage to the pavement surface. To minimize the effect of these problems programmed policies for pavement management are required. Additionally a given local anomaly on the road surface can affect the safety of the road to various degrees according to the category of the road, so it is possible to set up different programmes of repair according to the different standards of road. Programmed policies for pavement management are required because of the wide structural damage which occurs to pavements during their normal operating life. This has consequences for the safety and operability of road networks. During the last decade, road networks suffered from great structural damage. The damage occurs for different reasons, such as the increasing traffic or the lack of means for routine maintenance. Many forms of damage, originating in the bottom layers are invisible until the pavement cracks. They depend on the infiltration of water and the presence of cohesive soil greatly reduces the bearing capacity of the sub-asphalt layers and underlying soils. On the basis of an in-depth literature review, an experimental survey with Ground Penetrating Radar (GPR) was carried out to calibrate the geophysical parameters and to validate the reliability of an indirect diagnostic method of pavement damage. The experiments were set on a pavement under which water was injected over a period of several hours. GPR travel time data were used to estimate the dielectric constant and the water content in the unbound aggregate layer, the variations in water content with time and particular areas where rate of infiltration decreases. A new methodology has been proposed to extract the hydraulic permittivity fields in sub-asphalt structural layers and soils from the moisture maps observed with GPR. It is effective at diagnosing the presence of clay or cohesive soil that compromises the bearing capacity of sub-base and induces damage.

IMPERVIOUS SURFACES AND STREAMFLOW DISCHARGE: A HISTORICAL REMOTE SENSING PERSPECTIVE IN A NORTHERN VIRGINIA SUBWATERSHED

EPA Science Inventory

Impervious surfaces are a leading contributor to non-point-source water pollution in urban watersheds. These surfaces include such features as roads, parking lots, rooftops and driveways. Aerial photography provides a historical vehicle for determining impervious surface growth a...

Research on the calibration methods of the luminance parameter of radiation luminance meters

NASA Astrophysics Data System (ADS)

Cheng, Weihai; Huang, Biyong; Lin, Fangsheng; Li, Tiecheng; Yin, Dejin; Lai, Lei

2017-10-01

This paper introduces standard diffusion reflection white plate method and integrating sphere standard luminance source method to calibrate the luminance parameter. The paper compares the effects of calibration results by using these two methods through principle analysis and experimental verification. After using two methods to calibrate the same radiation luminance meter, the data obtained verifies the testing results of the two methods are both reliable. The results show that the display value using standard white plate method has fewer errors and better reproducibility. However, standard luminance source method is more convenient and suitable for on-site calibration. Moreover, standard luminance source method has wider range and can test the linear performance of the instruments.

An index for estimating the potential metal pollution contribution to atmospheric particulate matter from road dust in Beijing.

PubMed

Zhao, Hongtao; Shao, Yaping; Yin, Chengqing; Jiang, Yan; Li, Xuyong

2016-04-15

The resuspension of road dust from street surfaces could be a big contributor to atmospheric particulate pollution in the rapid urbanization context in the world. However, to date what its potential contribution to the spatial pattern is little known. Here we developed an innovative index model called the road dust index (RI<105μm) and it combines source and transport factors for road dust particles <105μm in diameter. It could quantify and differentiate the impact of the spatial distribution of the potential risks posed by metals associated with road dust on atmospheric suspended particles. The factors were ranked and weighted based on road dust characteristics (the amounts, grain sizes, and mobilities of the road dust, and the concentrations and toxicities of metals in the road dust). We then applied the RI<105μm in the Beijing region to assess the spatial distribution of the potential risks posed by metals associated with road dust on atmospheric suspended particles. The results demonstrated that the road dust in urban areas has higher potential risk of metal to atmospheric particles than that in rural areas. The RI<105μm method offers a new and useful tool for assessing the potential risks posed by metals associated with road dust on atmospheric suspended particles and for controlling atmospheric particulate pollution caused by road dust emissions. Copyright © 2016 Elsevier B.V. All rights reserved.

Predicting risk of trace element pollution from municipal roads using site-specific soil samples and remotely sensed data.

PubMed

Reeves, Mari Kathryn; Perdue, Margaret; Munk, Lee Ann; Hagedorn, Birgit

2018-07-15

Studies of environmental processes exhibit spatial variation within data sets. The ability to derive predictions of risk from field data is a critical path forward in understanding the data and applying the information to land and resource management. Thanks to recent advances in predictive modeling, open source software, and computing, the power to do this is within grasp. This article provides an example of how we predicted relative trace element pollution risk from roads across a region by combining site specific trace element data in soils with regional land cover and planning information in a predictive model framework. In the Kenai Peninsula of Alaska, we sampled 36 sites (191 soil samples) adjacent to roads for trace elements. We then combined this site specific data with freely-available land cover and urban planning data to derive a predictive model of landscape scale environmental risk. We used six different model algorithms to analyze the dataset, comparing these in terms of their predictive abilities and the variables identified as important. Based on comparable predictive abilities (mean R 2 from 30 to 35% and mean root mean square error from 65 to 68%), we averaged all six model outputs to predict relative levels of trace element deposition in soils-given the road surface, traffic volume, sample distance from the road, land cover category, and impervious surface percentage. Mapped predictions of environmental risk from toxic trace element pollution can show land managers and transportation planners where to prioritize road renewal or maintenance by each road segment's relative environmental and human health risk. Published by Elsevier B.V.

Concentrations and bioaccessibility of metals in vegetation and dust near a mining haul road, Cape Krusenstern National Monument, Alaska

USGS Publications Warehouse

Brumbaugh, William G.; Morman, Suzette A.; May, Thomas W.

2011-01-01

Vegetation, sub-surface peat, and road dust were sampled near the Delong Mountain Transportation System (DMTS) haul road in northwest Alaska in 2005-2006 to document aluminum, barium, cadmium, lead, and zinc concentrations, and to evaluate bioaccessibility of these metals. The DMTS haul road is the transport corridor between Red Dog Mine (a large-scale, lead-zinc mine and mill) and the coastal shipping port, and it traverses National Park Service lands. Compared to reference locations, total metal concentrations in four types of vegetation (birch, cranberry, and willow leaves, and cotton grass blades/stalks) collected 25 m from the haul road were enriched on average by factors of 3.5 for zinc, 8.0 for barium, 20 for cadmium, and 150 for lead. Triple rinsing of vegetation with a water/methanol mixture reduced metals concentrations by at most 50%, and cadmium and zinc concentrations were least affected by rinsing. Cadmium and zinc bioaccessibility was greater in vegetation (50% to 100%) than in dust (15% to 20%); whereas the opposite pattern was observed for lead bioaccessibility (<30% in vegetation; 50% in dust). Barium exhibited low-to-intermediate bioaccessibility in dust and vegetation (20% to 40%), whereas aluminum bioaccessibility was relatively low (<6%) in all sample types. Our reconnaissance-level study indicates that clean-up and improvements in lead/zinc concentrate transfer activities have been effective; however, as of 2006, metal dispersion from past and/or present releases of fugitive dusts along the DMTS road still may have been contributing to elevated metals in surface vegetation. Vegetation was most enriched in lead, but because bioaccessibility of cadmium was greater, any potential risks to animals that forage near the haul road might be equally important for both of these metals.

Does apical membrane GLUT2 have a role in intestinal glucose uptake?

PubMed

Naftalin, Richard J

2014-01-01

It has been proposed that the non-saturable component of intestinal glucose absorption, apparent following prolonged exposure to high intraluminal glucose concentrations, is mediated via the low affinity glucose and fructose transporter, GLUT2, upregulated within the small intestinal apical border. The evidence that the non-saturable transport component is mediated via an apical membrane sugar transporter is that it is inhibited by phloretin, after exposure to phloridzin. Since the other apical membrane sugar transporter, GLUT5, is insensitive to inhibition by either cytochalasin B, or phloretin, GLUT2 was deduced to be the low affinity sugar transport route. As in its uninhibited state, polarized intestinal glucose absorption depends both on coupled entry of glucose and sodium across the brush border membrane and on the enterocyte cytosolic glucose concentration exceeding that in both luminal and submucosal interstitial fluids, upregulation of GLUT2 within the intestinal brush border will usually stimulate downhill glucose reflux to the intestinal lumen from the enterocytes; thereby reducing, rather than enhancing net glucose absorption across the luminal surface. These states are simulated with a computer model generating solutions to the differential equations for glucose, Na and water flows between luminal, cell, interstitial and capillary compartments. The model demonstrates that uphill glucose transport via SGLT1 into enterocytes, when short-circuited by any passive glucose carrier in the apical membrane, such as GLUT2, will reduce transcellular glucose absorption and thereby lead to increased paracellular flow. The model also illustrates that apical GLUT2 may usefully act as an osmoregulator to prevent excessive enterocyte volume change with altered luminal glucose concentrations.

Does apical membrane GLUT2 have a role in intestinal glucose uptake?

PubMed Central

Naftalin, Richard J

2014-01-01

It has been proposed that the non-saturable component of intestinal glucose absorption, apparent following prolonged exposure to high intraluminal glucose concentrations, is mediated via the low affinity glucose and fructose transporter, GLUT2, upregulated within the small intestinal apical border. The evidence that the non-saturable transport component is mediated via an apical membrane sugar transporter is that it is inhibited by phloretin, after exposure to phloridzin. Since the other apical membrane sugar transporter, GLUT5, is insensitive to inhibition by either cytochalasin B, or phloretin, GLUT2 was deduced to be the low affinity sugar transport route. As in its uninhibited state, polarized intestinal glucose absorption depends both on coupled entry of glucose and sodium across the brush border membrane and on the enterocyte cytosolic glucose concentration exceeding that in both luminal and submucosal interstitial fluids, upregulation of GLUT2 within the intestinal brush border will usually stimulate downhill glucose reflux to the intestinal lumen from the enterocytes; thereby reducing, rather than enhancing net glucose absorption across the luminal surface. These states are simulated with a computer model generating solutions to the differential equations for glucose, Na and water flows between luminal, cell, interstitial and capillary compartments. The model demonstrates that uphill glucose transport via SGLT1 into enterocytes, when short-circuited by any passive glucose carrier in the apical membrane, such as GLUT2, will reduce transcellular glucose absorption and thereby lead to increased paracellular flow. The model also illustrates that apical GLUT2 may usefully act as an osmoregulator to prevent excessive enterocyte volume change with altered luminal glucose concentrations. PMID:25671087

Extensive Transcriptomic and Genomic Analysis Provides New Insights about Luminal Breast Cancers

PubMed Central

Tishchenko, Inna; Milioli, Heloisa Helena; Riveros, Carlos; Moscato, Pablo

2016-01-01

Despite constituting approximately two thirds of all breast cancers, the luminal A and B tumours are poorly classified at both clinical and molecular levels. There are contradictory reports on the nature of these subtypes: some define them as intrinsic entities, others as a continuum. With the aim of addressing these uncertainties and identifying molecular signatures of patients at risk, we conducted a comprehensive transcriptomic and genomic analysis of 2,425 luminal breast cancer samples. Our results indicate that the separation between the molecular luminal A and B subtypes—per definition—is not associated with intrinsic characteristics evident in the differentiation between other subtypes. Moreover, t-SNE and MST-kNN clustering approaches based on 10,000 probes, associated with luminal tumour initiation and/or development, revealed the close connections between luminal A and B tumours, with no evidence of a clear boundary between them. Thus, we considered all luminal tumours as a single heterogeneous group for analysis purposes. We first stratified luminal tumours into two distinct groups by their HER2 gene cluster co-expression: HER2-amplified luminal and ordinary-luminal. The former group is associated with distinct transcriptomic and genomic profiles, and poor prognosis; it comprises approximately 8% of all luminal cases. For the remaining ordinary-luminal tumours we further identified the molecular signature correlated with disease outcomes, exhibiting an approximately continuous gene expression range from low to high risk. Thus, we employed four virtual quantiles to segregate the groups of patients. The clinico-pathological characteristics and ratios of genomic aberrations are concordant with the variations in gene expression profiles, hinting at a progressive staging. The comparison with the current separation into luminal A and B subtypes revealed a substantially improved survival stratification. Concluding, we suggest a review of the definition of luminal A and B subtypes. A proposition for a revisited delineation is provided in this study. PMID:27341628

Streamflow gains and losses along San Francisquito Creek and characterization of surface-water and ground-water quality, southern San Mateo and northern Santa Clara counties, California, 1996-97

USGS Publications Warehouse

Metzger, Loren F.

2002-01-01

San Francisquito Creek is an important source of recharge to the 22-square-mile San Francisquito Creek alluvial fan ground-water subbasin in the southern San Mateo and northern Santa Clara Counties of California. Ground water supplies as much as 20 percent of the water to some area communities. Local residents are concerned that infiltration and consequently ground-water recharge would be reduced if additional flood-control measures are implemented along San Francisquito Creek. To improve the understanding of the surface-water/ground-water interaction between San Francisquito Creek and the San Francisquito Creek alluvial fan, the U.S. Geological Survey (USGS) estimated streamflow gains and losses along San Francisquito Creek and determined the chemical quality and isotopic composition of surface and ground water in the study area.Streamflow was measured at 13 temporary streamflow-measurement stations to determine streamflow gains and losses along a 8.4-mile section of San Francisquito Creek. A series of five seepage runs between April 1996 and May 1997 indicate that losses in San Francisquito Creek were negligible until it crossed the Pulgas Fault at Sand Hill Road. Streamflow losses increased between Sand Hill Road and Middlefield Road where the alluvial deposits are predominantly coarse-grained and the water table is below the bottom of the channel. The greatest streamflow losses were measured along a 1.8-mile section of the creek between the San Mateo Drive bike bridge and Middlefield Road; average losses between San Mateo Drive and Alma Street and from there to Middlefield Road were 3.1 and 2.5 acre-feet per day, respectively.Downstream from Middlefield Road, streamflow gains and losses owing to seepage may be masked by urban runoff, changes in bank storage, and tidal effects from San Francisco Bay. Streamflow gains measured between Middlefield Road and the 1200 block of Woodland Avenue may be attributable to urban runoff and (or) ground-water inflow. Water-level measurements from nearby wells indicate that the regional water table may coincide with the channel bottom along this reach of San Francisquito Creek, particularly during the winter and early spring when water levels usually reach their maximum. Streamflow losses resumed below the 1200 block of Woodland Avenue, extending downstream to Newell Road. Discharge from a large storm drain between Newell Road and East Bayshore Road may account for the streamflow gains measured between these sites. Streamflow gains were measured between East Bayshore Road and the Palo Alto Municipal Golf Course, but this reach is difficult to characterize because of the probable influence of high tides.Estimated average streamflow losses totaled approximately 1,050 acre-feet per year for the reaches between USGS stream gage 11164500 at Stanford University (upstream of Junipero Serra Boulevard) and the Palo Alto Municipal Golf Course, including approximately 595 acre-feet per year for the 1.8-mile section between San Mateo Drive and Middlefield Road. Approximately 58 percent, or 550 acre-feet, of the total estimated average annual recharge from San Francisquito Creek occurs between the San Mateo Drive and Middlefield Road sites.The chemical composition of San Francisquito Creek water varies as a function of seasonal changes in hydrologic conditions. Measurements of specific conductance indicate that during dry weather and low flow, the dissolved-solids concentrations tends to be high, and during wet weather, the concentration tends to be low owing to dilution by surface water. Compared with water samples from upstream sites at USGS stream gage 11164500 and San Mateo Drive, the samples from the downstream sites at Alma Street and Woodland Avenue had low specific conductance; low concentrations of magnesium, sodium, sulfate, chloride, boron, and total dissolved solids; high nutrient concentrations; and light isotopic compositions indicating that urban runoff constitutes most of the streamflow

Sign luminance requirements for various background complexities

DOT National Transportation Integrated Search

1985-09-01

The Federal standards (FP-79) for luminance of retroreflective materials for traffic signs are acceptance standards; they provide no differentiation based on driver need. Driver needs for sign luminance are of 3 types -- luminance for sign comprehens...

Experimental study of tyre/road contact forces in rolling conditions for noise prediction

NASA Astrophysics Data System (ADS)

Cesbron, Julien; Anfosso-Lédée, Fabienne; Duhamel, Denis; Ping Yin, Hai; Le Houédec, Donatien

2009-02-01

This paper deals with the experimental study of dynamical tyre/road contact for noise prediction. In situ measurements of contact forces and close proximity noise levels were carried out for a slick tyre rolling on six different road surfaces between 30 and 50 km/h. Additional texture profiles of the tested surfaces were taken on the wheel track. Normal contact stresses were measured at a sampling frequency of 10752 Hz using a line of pressure sensitive cells placed both along and perpendicular to the rolling direction. The contact areas obtained during rolling were smaller than in static conditions. This is mainly explained by the dynamical properties of tyre compounds, like the viscoelastic behaviour of the rubber. Additionally the root-mean-square of the resultant contact forces at various speeds was in the same order for a given road surface, while their spectra were quite different. This is certainly due to a spectral influence of bending waves propagating in the tyre during rolling, especially when the wavelength is small in comparison with the size of the contact patch. Finally, the levels of contact forces and close proximity noise measured at 30 km/h were correlated. Additional correlations with texture levels were performed. The results show that the macro-texture generates contact forces linearly around 800 Hz and consequently noise levels between 500 and 1000 Hz via the vibrations transmitted to the tyre.

Coffee-Ring-Free Quantum Dot Thin Film Using Inkjet Printing from a Mixed-Solvent System on Modified ZnO Transport Layer for Light-Emitting Devices.

PubMed

Jiang, Congbiao; Zhong, Zhiming; Liu, Baiquan; He, Zhiwei; Zou, Jianhua; Wang, Lei; Wang, Jian; Peng, JunBiao; Cao, Yong

2016-10-05

Inkjet printing has been considered an available way to achieve large size full-color RGB quantum dots LED display, and the key point is to obtain printed film with uniform and flat surface profile. In this work, mixed solvent of 20 vol % 1,2-dichlorobenzene (oDCB) with cyclohexylbenzene (CHB) was used to dissolve green quantum dots (QDs) with CdSe@ZnS/ZnS core/shell structure. Then, by inkjet printing, a flat dotlike QDs film without the coffee ring was successfully obtained on polyetherimide (PEI)-modified ZnO layer, and the printed dots array exhibited great stability and repeatability. Here, adding oDCB into CHB solutions was used to reduce surface tension, and employing ZnO nanoparticle layer with PEI-modified was used to increase the surface free energy. As a result, a small contact angle is formed, which leads to the enhancement of evaporation rate, and then the coffee ring effect was suppressed. The printed dots with flat surface profile were eventually realized. Moreover, inverted green QD-LEDs with PEI-modified ZnO film as electron transport layer (ETL) and printed green QDs film as emission layer were successfully fabricated. The QD-LEDs exhibited the maximum luminance of 12 000 cd/m 2 and the peak current efficiency of 4.5 cd/A at luminance of 1500 cd/m 2 .

Distribution of heavy metals in road dust along an urban-rural gradient in Massachusetts

NASA Astrophysics Data System (ADS)

Apeagyei, Eric; Bank, Michael S.; Spengler, John D.

2011-04-01

Human exposures to particulate matter emitted from on-road motor vehicles include complex mixtures of metals from tires, brakes, parts wear and resuspended road dust. The aim of this study was to assess road dust for metals associated with motor vehicle traffic, particularly those metals coming from brake and tire wears. We hypothesized that the road dust would show significant difference in both composition and concentration by traffic type, road class and by location. X-ray fluorescence (XRF) analyses of 115 parked car tires showed Zn and Ca were likely associated with tire wear dust. XRF results of three used brake pads indicated high concentrations of Fe, Ti, Cu, Ba, Mo and Zr. To assess heavy metal exposures associated with tires and brake wear adjacent to roads of varying traffic and functional classes, 85 samples of road dust were collected from road surfaces adjacent to the curb and analyzed by XRF. Median concentrations for Fe, Ca and K were greater than Ti (1619 ppm), with concentration ratios of Fe: Ca: K: Ti [16:5:3:1]. Cumulative frequency distribution graphs showed distribution of Fe, Ba, Cu, and Mo were similar regardless of road traffic rating. However, Zn, Ti, and Zr varied significantly ( p < 0.05) with traffic ratings of roadways (heavy > moderate > low traffic). Fe, Ba, Cu, and Mo also had similar distributions regardless of road class while composition of Zn, Ti, and Zr varied significantly across road class ( p < 0.05) (Major roads > Minor roads > highway). In comparing urban road dust to rural road dust, we observed Fe, Ca, K, and Ti were significantly greater in urban road dust ( p < 0.05). In urban road dust the Fe: Ca: K: Ti relationship with median Ti of 2216 ppm was 12: 6: 3.5: 1. These results indicate that roadway dust may be important sources of metals for runoff water and localized resuspended particulate matter.

Comparison of the predictions of two road dust emission models with the measurements of a mobile van

NASA Astrophysics Data System (ADS)

Kauhaniemi, M.; Stojiljkovic, A.; Pirjola, L.; Karppinen, A.; Härkönen, J.; Kupiainen, K.; Kangas, L.; Aarnio, M. A.; Omstedt, G.; Denby, B. R.; Kukkonen, J.

2014-02-01

The predictions of two road dust suspension emission models were compared with the on-site mobile measurements of suspension emission factors. Such a quantitative comparison has not previously been reported in the reviewed literature. The models used were the Nordic collaboration model NORTRIP (NOn-exhaust Road TRaffic Induced Particle emissions) and the Swedish-Finnish FORE model (Forecasting Of Road dust Emissions). These models describe particulate matter generated by the wear of road surface due to traction control methods and processes that control the suspension of road dust particles into the air. An experimental measurement campaign was conducted using a mobile laboratory called SNIFFER, along two selected road segments in central Helsinki in 2007 and 2008. The suspended PM10 concentration was measured behind the left rear tyre and the street background PM10 concentration in front of the van. Both models reproduced the measured seasonal variation of suspension emission factors fairly well during both years at both measurement sites. However, both models substantially under-predicted the measured emission values. The results indicate that road dust emission models can be directly compared with mobile measurements; however, more extensive and versatile measurement campaigns will be needed in the future.

Nitrogen and phosphorus associating with different size suspended solids in roof and road runoff in Beijing, China.

PubMed

Wu, Junliang; Ren, Yufen; Wang, Xuemei; Wang, Xiaoke; Chen, Liding; Liu, Gangcai

2015-10-01

Roofs and roads, accounting for a large portion of the urban impervious land surface, have contributed significantly to urban nonpoint pollution. In this study, in Beijing, China, roof and road runoff are sampled to measure the suspended solids (SS), nitrogen (N), and phosphorus (P) contained in particles with different sizes. The SS content in the road runoff (151.59 mg/L) was sevenfold that in the roof runoff (21.13 mg/L, p < 0.05). The SS contained more coarse particulates in the roof runoff than in road runoff. The small particulates in the range of 0.45-50 μm consisted of 59 % SS in the roof runoff and 94 % SS in the road runoff. P was mainly attached to particle sizes of 10-50 μm in the roof (73 %) and road (48 %) runoffs, while N was mainly in a dissolved phase state in both runoffs. So, the different associations of N and P raise a challenge in preventing stormwater pollution in urban environments.

Sodium bromide additive improved film morphology and performance in perovskite light-emitting diodes

NASA Astrophysics Data System (ADS)

Li, Jinghai; Cai, Feilong; Yang, Liyan; Ye, Fanghao; Zhang, Jinghui; Gurney, Robert S.; Liu, Dan; Wang, Tao

2017-07-01

Organometal halide perovskite is a promising material to fabricate light-emitting diodes (LEDs) via solution processing due to its exceptional optoelectronic properties. However, incomplete precursor conversion and various defect states in the perovskite light-emitting layer lead to low luminance and external quantum efficiency of perovskite LEDs. We show here the addition of an optimum amount of sodium bromide in the methylammonium lead bromide (MAPbBr3) precursor during a one-step perovskite solution casting process can effectively improve the film coverage, enhance the crystallinity, and passivate ionic defects on the surface of MAPbBr3 crystal grains, resulting in LEDs with a reduced turn-on voltage from 2.8 to 2.3 V and an enhanced maximum luminance from 1059 to 6942 Cd/m2 when comparing with the pristine perovskite-based device.

Visual Costs of the Inhomogeneity of Luminance and Contrast by Viewing LCD-TFT Screens Off-Axis.

PubMed

Ziefle, Martina; Groeger, Thomas; Sommer, Dietmar

2003-01-01

In this study the anisotropic characteristics of TFT-LCD (Thin-Film-Transistor-Liquid Crystal Display) screens were examined. Anisotropy occurs as the distribution of luminance and contrast changes over the screen surface due to different viewing angles. On the basis of detailed photometric measurements the detection performance in a visual reaction task was measured in different viewing conditions. Viewing angle (0 degrees, frontal view; 30 degrees, off-axis; 50 degrees, off-axis) as well as ambient lighting (a dark or illuminated room) were varied. Reaction times and accuracy of detection performance were recorded. Results showed TFT's anisotropy to be a crucial factor deteriorating performance. With an increasing viewing angle performance decreased. It is concluded that TFT's anisotropy is a limiting factor for overall suitability and usefulness of this new display technology.

Effects of roads and well pads on erosion in the Largo Canyon watershed, New Mexico, 2001-02

USGS Publications Warehouse

Matherne, Anne Marie

2006-01-01

Largo Canyon, located in the San Juan Basin of northwestern New Mexico, is one of the longest dry washes in the world. Oil and gas production in the San Juan Basin, which began in the 1940's, required the development of an extensive network of dirt roads to service the oil and gas wells in the Navajo Reservoir area. Presently, there are about eight wells per square mile, and the density of oil and gas wells is expected to increase. Potential environmental effects on landscape stability that may result from the additional roads and well pads have not been documented. In 2001, the U.S. Geological Survey began a study in cooperation with the Bureau of Land Management to evaluate the effects of roads and well pads associated with oil and gas operations on the erosion potential of Bureau of Land Management lands in the Largo Canyon watershed. The effects of roads and well pads on erosion were quantified by installing sediment dams (dams) and by surveying transects across roads and well pads. Data from 26 dams were used in the analysis. Dams were installed at 43 sites: 21 on hillsides upslope from roads or pads to measure erosion from hillslopes, 11 at the downslope edges of roads to measure erosion from roads, and 11 at the downslope edges of well pads to measure erosion from well pads. Pairs of survey transects were established at nine well pads and two road locations. Sediment-accumulation data for 26 dams, recorded at 17 measurement intervals, indicate that average erosion rates at the dams significantly correlate to size of the contributing area. The average erosion rate normalized by drainage area was 0.001 foot per year below roads, 0.003 foot per year on hillslopes, and 0.011 foot per year below well pads. Results of a two-sample t-test indicate that there was no significant difference in average erosion rates for dams located on hillslopes and below roads, whereas average erosion rates were significantly greater for dams below well pads than for dams on hillslopes and dams below roads. The average erosion rates estimated from the data collected during this study most likely represent minimum erosion rates. Sediment-accumulation data for measurement intervals and for dams that were breached during 2002, resulting from the large volume of runoff generated by high-intensity storms, were not used to compute erosion rates. For this reason, the higher range of erosion rates is underrepresented and the results of this study are biased toward the lower end of the range of erosion rates. Measurements along road transects generally indicate that sediment is eroded from the top of road berms and redeposited at the base of the berms and may be transported downslope along the road. Measurements along well-pad transects generally indicate that sediment eroded from hillslopes is transported over the surface of the well pad and down the well-pad edges. Based on field observations, roads aligned parallel to topographic contours facilitate erosional processes in two ways: (1) roads cut across and collect runoff from previously established drainages and (2) roads, where they are cut into hillsides or into the land surface, provide focal points for the initiation of erosion. Roads aligned across topographic contours can serve as conduits to channel runoff but do not constitute a large percentage of the road network.

Vehicular road influence areas

NASA Astrophysics Data System (ADS)

Huertas, María E.; Huertas, José I.; Valencia, Alexander

2017-02-01

Vehicle operation over paved and unpaved roads is an emission source that significantly contributes to air pollution. Emissions are derived from vehicle exhaust pipes and re-suspension of particulate matter generated by wind erosion and tire to road surface interactions. Environmental authorities require a methodology to evaluate road impact areas, which enable managers to initiate counter-measures, particularly under circumstances where historic meteorological and/or air quality data is unavailable. The present study describes an analytical and experimental work developed to establish a simplified methodology to estimate the area influenced by vehicular roads. AERMOD was chosen to model pollutant dispersion generated by two roads of common attributes (straight road over flat terrain) under the effects of several arbitrary chosen weather conditions. The resulting pollutant concentration vs. Distance curves collapsed into a single curve when concentration and distance were expressed as dimensionless numbers and this curve can be described by a beta distribution function. This result implied that average concentration at a given distance was proportional to emission intensity and that it showed minor sensitivity to meteorological conditions. Therefore, road influence was defined by the area adjacent to the road limited by distance at which the beta distribution function equaled the limiting value specified by the national air quality standard for the pollutant under consideration.

Comparison of the predictions of two road dust emission models with the measurements of a mobile van

NASA Astrophysics Data System (ADS)

Kauhaniemi, M.; Stojiljkovic, A.; Pirjola, L.; Karppinen, A.; Härkönen, J.; Kupiainen, K.; Kangas, L.; Aarnio, M. A.; Omstedt, G.; Denby, B. R.; Kukkonen, J.

2014-09-01

The predictions of two road dust suspension emission models were compared with the on-site mobile measurements of suspension emission factors. Such a quantitative comparison has not previously been reported in the reviewed literature. The models used were the Nordic collaboration model NORTRIP (NOn-exhaust Road TRaffic Induced Particle emissions) and the Swedish-Finnish FORE model (Forecasting Of Road dust Emissions). These models describe particulate matter generated by the wear of road surface due to traction control methods and processes that control the suspension of road dust particles into the air. An experimental measurement campaign was conducted using a mobile laboratory called SNIFFER, along two selected road segments in central Helsinki in 2007 and 2008. The suspended PM10 concentration was measured behind the left rear tyre and the street background PM10 concentration in front of the van. Both models reproduced the measured seasonal variation of suspension emission factors fairly well during both years at both measurement sites. However, both models substantially under-predicted the measured emission values. The article illustrates the challenges in conducting road suspension measurements in densely trafficked urban conditions, and the numerous requirements for input data that are needed for accurately applying road suspension emission models.

Surface-Water Exchange through Culverts beneath State Road 9336 within Everglades National Park, 2004-05

USGS Publications Warehouse

Schaffranek, Raymond W.; Stewart, Marc A.; Nowacki, Daniel J.

2008-01-01

The U.S. Geological Survey collected hydrologic data between June 2004 and December 2005 to investigate the temporal and spatial nature of flow exchanges through culverts beneath State Road 9336 within Everglades National Park. Continuous data collected during the study measured flow velocity, water level, salinity, conductivity, and water-temperature in or near seven culverts between Pa-hay-okee Overlook access road and Nine Mile Pond. The two culverts east of Pa-hay-okee Overlook access road flowed into Taylor Slough Basin from 87 to 96 percent of the study period, whereas flows through five culverts between Pa-hay-okee Overlook access road and Nine Mile Pond flowed into Shark River Slough Basin from 70 to 99 percent of the study period. Synoptic flow discharges measured at all culverts during three intensive field efforts revealed a net discharge into Taylor Slough Basin from Shark River Slough Basin through culverts between Royal Palm Road and Pa-hay-okee Overlook access road, and into Shark River Slough Basin from Taylor Slough Basin through culverts between Pa-hay-okee Overlook access road and Nine Mile Pond. Data collected during the study and presented in this report provided additional knowledge of the magnitude, direction, and nature of flow exchanges through the road culverts.

Automated management for pavement inspection system (AMPIS)

NASA Astrophysics Data System (ADS)

Chung, Hung Chi; Girardello, Roberto; Soeller, Tony; Shinozuka, Masanobu

2003-08-01

An automated in-situ road surface distress surveying and management system, AMPIS, has been developed on the basis of video images within the framework of GIS software. Video image processing techniques are introduced to acquire, process and analyze the road surface images obtained from a moving vehicle. ArcGIS platform is used to integrate the routines of image processing and spatial analysis in handling the full-scale metropolitan highway surface distress detection and data fusion/management. This makes it possible to present user-friendly interfaces in GIS and to provide efficient visualizations of surveyed results not only for the use of transportation engineers to manage road surveying documentations, data acquisition, analysis and management, but also for financial officials to plan maintenance and repair programs and further evaluate the socio-economic impacts of highway degradation and deterioration. A review performed in this study on fundamental principle of Pavement Management System (PMS) and its implementation indicates that the proposed approach of using GIS concept and its tools for PMS application will reshape PMS into a new information technology-based system providing a convenient and efficient pavement inspection and management.

Responses of Roadside Soil Cation Pools to Vehicular Emission Deposition in Southern California

NASA Astrophysics Data System (ADS)

Rossi, R.; Bain, D. J.; Jenerette, D.; Clarke, L. W.; Wilson, K.

2013-12-01

Roadside soils are heavily loaded with NO3- due to vehicular emissions. This deposition likely acidifies these soils, potentially mobilizing cationic species from soil exchange sites. Acidification driven mobilization is well documented in forest soils, but poorly understood in roadside soils. Metal concentrations in park and garden soils collected from Southern California were examined across gradients of soil chemistry, road network density, climate, and geology to examine cation mobilization effects. In our samples, soil pH is not clearly related to distance from the roadside or underlying geology. However, the depletion of several elements (Al, K) is clearly observed in near-road environments. These depletion trends occur despite contrary trends, including increased soil surface areas and soil organic matter in near-road environments. Additionally, inputs from the weathering of road building materials appear to affect soil chemistry. For example, soil Ca patterns remain relatively consistent relative to roads, suggesting Ca bearing weathering products replenish soil Ca pools in near-road areas. Simple mixing models constructed using elemental ratios are consistent with road material Ca source contributions. Observed near-road patterns in soil chemistry likely influence local ecological function, shifting plant communities and soil functions. Clear understanding of these shifts is essential to the effective use of green infrastructure and other strategies utilized to control road-sourced nutrients. This analytical framework can be applied globally as road networks continue to expand and affect larger ecosystems.

Central Tire Inflation: Demonstration Tests in the South

Treesearch

R.B. Rummer; C. Ashmore; D.L. Sirois; C.L. Rawlins

1990-01-01

Tests of prototype Central Tire Inflation (CT11 systems were conducted to quantify CT1 performance, road wear, and truck vibration. The CT1 systems were tested in both experimental and operational settings. Changes in the road surface that occurred during the tests could not be statistically attributed to reduced tire pressure. Vibration at the seat base, however,...

78 FR 27132 - Special Regulations of the National Park Service, Curecanti National Recreation Area, Snowmobiles...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-09

... operation of motor vehicles between the high-water mark and the water surface of Blue Mesa Reservoir for the... motor vehicles may be used off park roads. Unless authorized by special regulation, the operation of snowmobiles and the operation of motor vehicles off road within areas of the National Park System are...

Surface Erosion Control Techniques on Newly Constructed Forest Roads

Treesearch

Johnny M. Grace; John Wilhoit; Robert Rummer; Bryce Stokes

1999-01-01

A newly constructed forest road was treated with three erosion control treatments: wood excelsior erosion mat, native grass species, and exotic grass species. The study evaluates treatment methods on the basis of sediment reduction and runoff volume reduction compared to no treatment. The erosion mat treatment was most effective in mitigating erosion losses with a 98...

Regional analysis of the effect of paved roads on sodium and chloride in lakes.

PubMed

Kelting, Daniel L; Laxson, Corey L; Yerger, Elizabeth C

2012-05-15

Salinization of surface water from sodium chloride (road salt) applied to paved roads is a widely recognized environmental concern in the northern hemisphere, yet practical information to improve winter road management to reduce the environmental impacts of this deicer is lacking. The purpose of our study was to provide such information by developing baseline concentrations for sodium and chloride for lakes in watersheds without paved roads, and then determining the relationship between these ions and density, type, and proximity of paved roads to shoreline. We used average summer (June-September) sodium and chloride data for 138 lakes combined in a watershed based analysis of paved road networks in the Adirondack Park of New York, U.S.A. The watersheds used in our study represented a broad range in paved road density and type, 56 of which had no paved roads. Median lake sodium and chloride concentrations in these 56 watersheds averaged 0.55 and 0.24 mg/L, respectively. In contrast, the median sodium and chloride concentrations for the 82 lakes in watersheds with paved roads were 3.60 and 7.22 mg/L, respectively. Paved road density (lane-km/km(2)) was positively correlated with sodium and chloride concentrations, but only state roads were significantly correlated with sodium and chloride while local roads were not. State road density alone explained 84 percent of the variation in both ions. We also successfully modeled the relationship between road proximity to shoreline and sodium and chloride concentrations in lakes, which allowed us to identify sections of road that contributed more to explaining the variation in sodium and chloride in lakes. This model and our approach could be used as part of larger efforts to identify environmentally sensitive areas where alternative winter road management treatments should be applied. Copyright © 2012 Elsevier Ltd. All rights reserved.

The perceptual consequences of interocular suppression in amblyopia.

PubMed

Maehara, Goro; Thompson, Benjamin; Mansouri, Behzad; Farivar, Reza; Hess, Robert F

2011-11-21

It is known that information from an amblyopic eye can be strongly suppressed when both eyes are open. The authors investigated the way in which suppression influences the relative perception of suprathreshold contrast and luminance between a person's eyes under dichoptic viewing conditions. Stimuli consisted of four patches of luminance or four patches containing gratings. Two patches were presented to each eye. Ten amblyopes with mild suppression (six strabismic, three anisometropic and strabismic, and one deprivation; mean age, 34.5 years) and three control observers with normal vision (mean age, 33.0 years) matched the appearance of the stimuli presented to each eye. The match involved manipulation of either luminance or contrast. Amblyopes with mild suppression decreased stimulus luminance in the fellow fixing eye or increased luminance in the amblyopic eye to achieve a match (mean matching luminance, 21.1 and 39.6 cd/m(2) for the fellow fixing eye and the amblyopic eye, respectively; standard luminance, 30 cd/m(2)). This interocular mismatch was also observed when luminance was variable and contrast was kept constant (mean matching luminance, 22.8 cd/m(2) for the fellow fixing eye). On the other hand, the amblyopic eye showed no loss of perceived contrast. There was little or no mismatch between the two eyes of control participants with normal binocular vision. Amblyopes have monocular deficits in contrast perception but dichoptic deficits in luminance perception, suggesting that suppression in its mild form involves luminance processing.

Low-cost rural surface alternatives : demonstration project : [tech transfer summary].

DOT National Transportation Integrated Search

2015-06-01

Identify the most effective and economical methods for preventing or : mitigating freeze-thaw damage to granular surfaced roads in seasonally : cold regions : Construct demonstration test sections using several stabilization : methods recomme...

Particle size distribution variance in untreated urban runoff and its implication on treatment selection.

PubMed

Charters, Frances J; Cochrane, Thomas A; O'Sullivan, Aisling D

2015-11-15

Understanding the particle size distribution (PSD) of sediment in urban runoff assists in the selection of appropriate treatment systems for sediment removal as systems vary in their ability to remove sediment across different particle size fractions. Variation in PSD in runoff from individual urban surfaces both during and across multiple rain events is not well understood and it may lead to performance uncertainty in treatment systems. Runoff PSDs in international literature were compiled to provide a comparative summary of PSDs from different urban surfaces. To further assess both intra-event and inter-event PSD variation, untreated runoff was collected from road, concrete roof, copper roof, and galvanized roof surfaces within an urban catchment exposed to the same rainfall conditions and analysed for PSD and total suspended solids (TSS). Road runoff had the highest TSS concentrations, while copper roofs had high initial TSS that reduced to very low levels under steady state conditions. Despite variation in TSS concentrations, the median particle diameter of the TSS was comparable across the surfaces. Intra-event variation was generally not significant, but substantial inter-event variation was observed, particularly for coarser road and concrete roof surfaces. PSD variation for each surface contributed to a wide range in predicted treatment performance and suggests that short-retention treatment devices carry a high performance risk of not being able to achieve adequate TSS removal across all rain events. Copyright © 2015 Elsevier Ltd. All rights reserved.

Generating strain signals under consideration of road surface profiles

NASA Astrophysics Data System (ADS)

Putra, T. E.; Abdullah, S.; Schramm, D.; Nuawi, M. Z.; Bruckmann, T.

2015-08-01

The current study aimed to develop the mechanism for generating strain signal utilising computer-based simulation. The strain data, caused by the acceleration, were undertaken from a fatigue data acquisition involving car movements. Using a mathematical model, the measured strain signals yielded to acceleration data used to describe the bumpiness of road surfaces. The acceleration signals were considered as an external disturbance on generating strain signals. Based on this comparison, both the actual and simulated strain data have similar pattern. The results are expected to provide new knowledge to generate a strain signal via a simulation.

Chromatic blur perception in the presence of luminance contrast.

PubMed

Jennings, Ben J; Kingdom, Frederick A A

2017-06-01

Hel-Or showed that blurring the chromatic but not the luminance layer of an image of a natural scene failed to elicit any impression of blur. Subsequent studies have suggested that this effect is due either to chromatic blur being masked by spatially contiguous luminance edges in the scene (Journal of Vision 13 (2013) 14), or to a relatively compressed transducer function for chromatic blur (Journal of Vision 15 (2015) 6). To test between the two explanations we conducted experiments using as stimuli both images of natural scenes as well as simple edges. First, we found that in color-and-luminance images of natural scenes more chromatic blur was needed to perceptually match a given level of blur in an isoluminant, i.e. colour-only scene. However, when the luminance layer in the scene was rotated relative to the chromatic layer, thus removing the colour-luminance edge correlations, the matched blur levels were near equal. Both results are consistent with Sharman et al.'s explanation. Second, when observers matched the blurs of luminance-only with isoluminant scenes, the matched blurs were equal, against Kingdom et al.'s prediction. Third, we measured the perceived blur in a square-wave as a function of (i) contrast (ii) number of luminance edges and (iii) the relative spatial phase between the colour and luminance edges. We found that the perceived chromatic blur was dependent on both relative phase and the number of luminance edges, or dependent on the luminance contrast if only a single edge is present. We conclude that this Hel-Or effect is largely due to masking of chromatic blur by spatially contiguous luminance edges. Copyright © 2017 Elsevier Ltd. All rights reserved.

The laboratory station for tyres grip testing on different surfaces

NASA Astrophysics Data System (ADS)

Kalinowski, K.; Grabowik, C.; Janik, W.; Ćwikła, G.; Skowera, M.

2015-11-01

The paper presents the conception of the device for tyre grip testing in the laboratory conditions. The main purpose is to provide a device working in confined spaces, which enables rapid changes of the tested samples of the road surfaces. Among the key assumptions the minimization of the device dimensions and the relative ease of transportation and mobility - the ability to quick assemble and disassemble were also assumed. The main components of the projected workstation includes: the replaceable platform for mounting samples of a road surface, the roller conveyor, the drive of the platform, the wheel mounting assembly and the axial force measuring system. At the design the station a morphological structure method has been used, particular elements have been optimized individually.

Photometric Compliance of Tablet Screens and Retro-Illuminated Acuity Charts As Visual Acuity Measurement Devices.

PubMed

Livingstone, I A T; Tarbert, C M; Giardini, M E; Bastawrous, A; Middleton, D; Hamilton, R

2016-01-01

Mobile technology is increasingly used to measure visual acuity. Standards for chart-based acuity tests specify photometric requirements for luminance, optotype contrast and luminance uniformity. Manufacturers provide some photometric data but little is known about tablet performance for visual acuity testing. This study photometrically characterised seven tablet computers (iPad, Apple inc.) and three ETDRS (Early Treatment Diabetic Retinopathy Study) visual acuity charts with room lights on and off, and compared findings with visual acuity measurement standards. Tablet screen luminance and contrast were measured using nine points across a black and white checkerboard test screen at five arbitrary brightness levels. ETDRS optotypes and adjacent white background luminance and contrast were measured. All seven tablets (room lights off) exceeded the most stringent requirement for mean luminance (≥ 120 cd/m2) providing the nominal brightness setting was above 50%. All exceeded contrast requirement (Weber ≥ 90%) regardless of brightness setting, and five were marginally below the required luminance uniformity threshold (Lmin/Lmax ≥ 80%). Re-assessing three tablets with room lights on made little difference to mean luminance or contrast, and improved luminance uniformity to exceed the threshold. The three EDTRS charts (room lights off) had adequate mean luminance (≥ 120 cd/m2) and Weber contrast (≥ 90%), but all three charts failed to meet the luminance uniformity standard (Lmin/Lmax ≥ 80%). Two charts were operating beyond manufacturer's recommended lamp replacement schedule. With room lights on, chart mean luminance and Weber contrast increased, but two charts still had inadequate luminance uniformity. Tablet computers showed less inter-device variability, higher contrast, and better luminance uniformity than charts in both lights-on and lights-off environments, providing brightness setting was >50%. Overall, iPad tablets matched or marginally out-performed ETDRS charts in terms of photometric compliance with high contrast acuity standards.

Photometric Compliance of Tablet Screens and Retro-Illuminated Acuity Charts As Visual Acuity Measurement Devices

PubMed Central

Livingstone, I. A. T.; Tarbert, C. M.; Giardini, M. E.; Bastawrous, A.; Middleton, D.; Hamilton, R.

2016-01-01

Mobile technology is increasingly used to measure visual acuity. Standards for chart-based acuity tests specify photometric requirements for luminance, optotype contrast and luminance uniformity. Manufacturers provide some photometric data but little is known about tablet performance for visual acuity testing. This study photometrically characterised seven tablet computers (iPad, Apple inc.) and three ETDRS (Early Treatment Diabetic Retinopathy Study) visual acuity charts with room lights on and off, and compared findings with visual acuity measurement standards. Tablet screen luminance and contrast were measured using nine points across a black and white checkerboard test screen at five arbitrary brightness levels. ETDRS optotypes and adjacent white background luminance and contrast were measured. All seven tablets (room lights off) exceeded the most stringent requirement for mean luminance (≥ 120 cd/m2) providing the nominal brightness setting was above 50%. All exceeded contrast requirement (Weber ≥ 90%) regardless of brightness setting, and five were marginally below the required luminance uniformity threshold (Lmin/Lmax ≥ 80%). Re-assessing three tablets with room lights on made little difference to mean luminance or contrast, and improved luminance uniformity to exceed the threshold. The three EDTRS charts (room lights off) had adequate mean luminance (≥ 120 cd/m2) and Weber contrast (≥ 90%), but all three charts failed to meet the luminance uniformity standard (Lmin/Lmax ≥ 80%). Two charts were operating beyond manufacturer’s recommended lamp replacement schedule. With room lights on, chart mean luminance and Weber contrast increased, but two charts still had inadequate luminance uniformity. Tablet computers showed less inter-device variability, higher contrast, and better luminance uniformity than charts in both lights-on and lights-off environments, providing brightness setting was >50%. Overall, iPad tablets matched or marginally out-performed ETDRS charts in terms of photometric compliance with high contrast acuity standards. PMID:27002333

Experimental studies about the impact of traction sand on urban road dust composition.

PubMed

Kupiainen, Kaarle; Tervahattu, Heikki; Räisänen, Mika

2003-06-01

Traffic causes enhanced PM(10) resuspension especially during spring in the US, Japan, Norway, Sweden and Finland, among other countries. The springtime PM(10) consists primarily of mineral matter from tyre-induced paved road surface wear and traction sand. In some countries, the majority of vehicles are equipped with studded tyres to enhance traction, which additionally increases road surface wear. Because the traction sand and the mineral matter from the pavement aggregate can have a similar mineralogical composition, it has been difficult to determine the source of the mineral fraction in the PM(10). In this study, homogenous traction sand and pavement aggregate with different mineralogical compositions were chosen to determine the sources of PM(10) particles by single particle analysis (SEM/EDX). This study was conducted in a test facility, which made it possible to rule out dust contributions from other sources. The ambient PM(10) concentrations were higher when traction sand was used, regardless of whether the tyres were studded or not. Surprisingly, the use of traction sand greatly increased the number of the particles originating from the pavement. It was concluded that sand must contribute to pavement wear. This phenomenon is called the sandpaper effect. An understanding of this is important to reduce harmful effects of springtime road dust in practical winter maintenance of urban roads

Automotive System for Remote Surface Classification.

PubMed

Bystrov, Aleksandr; Hoare, Edward; Tran, Thuy-Yung; Clarke, Nigel; Gashinova, Marina; Cherniakov, Mikhail

2017-04-01

In this paper we shall discuss a novel approach to road surface recognition, based on the analysis of backscattered microwave and ultrasonic signals. The novelty of our method is sonar and polarimetric radar data fusion, extraction of features for separate swathes of illuminated surface (segmentation), and using of multi-stage artificial neural network for surface classification. The developed system consists of 24 GHz radar and 40 kHz ultrasonic sensor. The features are extracted from backscattered signals and then the procedures of principal component analysis and supervised classification are applied to feature data. The special attention is paid to multi-stage artificial neural network which allows an overall increase in classification accuracy. The proposed technique was tested for recognition of a large number of real surfaces in different weather conditions with the average accuracy of correct classification of 95%. The obtained results thereby demonstrate that the use of proposed system architecture and statistical methods allow for reliable discrimination of various road surfaces in real conditions.

Automotive System for Remote Surface Classification

PubMed Central

Bystrov, Aleksandr; Hoare, Edward; Tran, Thuy-Yung; Clarke, Nigel; Gashinova, Marina; Cherniakov, Mikhail

2017-01-01

In this paper we shall discuss a novel approach to road surface recognition, based on the analysis of backscattered microwave and ultrasonic signals. The novelty of our method is sonar and polarimetric radar data fusion, extraction of features for separate swathes of illuminated surface (segmentation), and using of multi-stage artificial neural network for surface classification. The developed system consists of 24 GHz radar and 40 kHz ultrasonic sensor. The features are extracted from backscattered signals and then the procedures of principal component analysis and supervised classification are applied to feature data. The special attention is paid to multi-stage artificial neural network which allows an overall increase in classification accuracy. The proposed technique was tested for recognition of a large number of real surfaces in different weather conditions with the average accuracy of correct classification of 95%. The obtained results thereby demonstrate that the use of proposed system architecture and statistical methods allow for reliable discrimination of various road surfaces in real conditions. PMID:28368297

Conjunctions of colour, luminance and orientation: the role of colour and luminance contrast on saliency and proximity grouping in texture segregation.

PubMed

Leonards, U; Singer, W

2000-01-01

To examine whether perceptual grouping on the basis of orientation can be performed simultaneously with or only subsequently to grouping according to colour or luminance, we tested whether subjects are able to segregate arrays of texture elements that differ from surrounding elements by conjunctions of either (i) colour and orientation, or (ii) luminance contrast and orientation, or (iii) luminance contrast polarity and orientation. Subjects were able to use conjunctions between luminance and orientation for segregation but not conjunctions between colour or contrast polarity and orientation. Our results suggest that (i) in agreement with earlier findings, there seem to exist no specific conjunction detectors for colour and orientation or contrast polarity and orientation, and (ii) when orientation defined textures are to be distinguished by virtue of differences in luminance, colour, or contrast polarity, luminance provides a much stronger cue than colour or contrast polarity for saliency-based orientation grouping.

Neural mechanism for sensing fast motion in dim light.

PubMed

Li, Ran; Wang, Yi

2013-11-07

Luminance is a fundamental property of visual scenes. A population of neurons in primary visual cortex (V1) is sensitive to uniform luminance. In natural vision, however, the retinal image often changes rapidly. Consequently the luminance signals visual cells receive are transiently varying. How V1 neurons respond to such luminance changes is unknown. By applying large static uniform stimuli or grating stimuli altering at 25 Hz that resemble the rapid luminance changes in the environment, we show that approximately 40% V1 cells responded to rapid luminance changes of uniform stimuli. Most of them strongly preferred luminance decrements. Importantly, when tested with drifting gratings, the preferred speeds of these cells were significantly higher than cells responsive to static grating stimuli but not to uniform stimuli. This responsiveness can be accounted for by the preferences for low spatial frequencies and high temporal frequencies. These luminance-sensitive cells subserve the detection of fast motion under the conditions of dim illumination.

Geogrid reinforced road subgrade influence on the pavement evenness

NASA Astrophysics Data System (ADS)

Šiukščius, A.; Vorobjovas, V.; Vaitkus, A.

2018-05-01

As a result of increasing geogrid reinforcement applications in the road subgrade, there are number of projects where geogrid reinforcement is used to control road pavement evenness when there are small layers of peat or mud deeper under road construction. For this task geogrid reinforcement application is not documented but widely used in Lithuania for over a decade. This paper evaluates the long term influence of the geogrid reinforced soil influence on the road surface evenness, when the organic soils stratify in the deeper layers of the subgrade. The geological conditions of the investigated sections are reviewed. The experiment methodology and test results are described, which leads to the conclusions and insights how the pavement evenness depend on the geological conditions and its enhancement. The question is raised about the need for including this geogrid application to the normative documentation. Explanation of the problems that are encountered and the need for further research is given.

Tyre-road friction coefficient estimation based on tyre sensors and lateral tyre deflection: modelling, simulations and experiments

NASA Astrophysics Data System (ADS)

Hong, Sanghyun; Erdogan, Gurkan; Hedrick, Karl; Borrelli, Francesco

2013-05-01

The estimation of the tyre-road friction coefficient is fundamental for vehicle control systems. Tyre sensors enable the friction coefficient estimation based on signals extracted directly from tyres. This paper presents a tyre-road friction coefficient estimation algorithm based on tyre lateral deflection obtained from lateral acceleration. The lateral acceleration is measured by wireless three-dimensional accelerometers embedded inside the tyres. The proposed algorithm first determines the contact patch using a radial acceleration profile. Then, the portion of the lateral acceleration profile, only inside the tyre-road contact patch, is used to estimate the friction coefficient through a tyre brush model and a simple tyre model. The proposed strategy accounts for orientation-variation of accelerometer body frame during tyre rotation. The effectiveness and performance of the algorithm are demonstrated through finite element model simulations and experimental tests with small tyre slip angles on different road surface conditions.

[Experimental study on a novel esophageal prosthesis made of composite biomaterials].

PubMed

Qin, Xiong; Xu, Zhi-fei; Shi, Hong-can; Zhao, Xue-wei; Sun, Kang; Gao, Xiang-yang

2003-07-01

To design and develop a novel esophageal prosthesis by selecting appropriate biomaterials, developing special manufacturing techniques, and investigating the feasibility of replacement of cervical esophagus in mongrel dogs. In accordance with the requirements of ideal esophageal substitutes, we designed a new type of esophageal prostheses. The inner stent were made with polyurethane of medical grade, and the outer surface of the prosthesis was coated with collagen-chitosan sponge. The silicone tube was used as a control. Thirteen adult mongrel dogs that were divided into two groups were used to establish the experimental models. In the experimental group (n = 8), the esophageal prostheses were completely incorporated with the native esophagus and adherent to the surrounding host connective tissues. Epithelial linings of varying degrees were formed on the luminal surface, and complete epithelization was seen in 1 month postoperatively. The granulation at the sites of the anastomosis in this group was less significant than that of the control group. One dog has been surviving for 12 months up to now without any complications. In the control group (n = 5), esophageal epithelial was not observed on the luminal surface, constriction of the regenerated esophagus progressed and all the dogs died within 2 months after operation. These observations suggest that this esophageal prosthesis made of composite biomaterials has high biocompatibility and potential for long-segment esophageal reconstruction, which is promising for the clinical repair of esophageal defects.

Distinguishing Low-Risk Luminal A Breast Cancer Subtypes with Ki-67 and p53 Is More Predictive of Long-Term Survival

PubMed Central

Lee, Se Kyung; Bae, Soo Youn; Lee, Jun Ho; Lee, Hyun-Chul; Yi, Hawoo; Kil, Won Ho; Lee, Jeong Eon; Kim, Seok Won; Nam, Seok Jin

2015-01-01

Overexpression of p53 is the most frequent genetic alteration in breast cancer. Recently, many studies have shown that the expression of mutant p53 differs for each subtype of breast cancer and is associated with different prognoses. In this study, we aimed to determine the suitable cut-off value to predict the clinical outcome of p53 overexpression and its usefulness as a prognostic factor in each subtype of breast cancer, especially in luminal A breast cancer. Approval was granted by the Institutional Review Board of Samsung Medical Center. We analyzed a total of 7,739 patients who were surgically treated for invasive breast cancer at Samsung Medical Center between Dec 1995 and Apr 2013. Luminal A subtype was defined as ER&PR + and HER2- and was further subclassified according to Ki-67 and p53 expression as follows: luminal A (Ki-67-,p53-), luminal A (Ki-67+, p53-), luminal A (Ki-67 -, p53+) and luminal A (Ki-67+, p53+). Low-risk luminal A subtype was defined as negative for both Ki-67 and p53 (luminal A [ki-67-, p53-]), and others subtypes were considered to be high-risk luminal A breast cancer. A cut-off value of 10% for p53 was a good predictor of clinical outcome in all patients and luminal A breast cancer patients. The prognostic role of p53 overexpression for OS and DFS was only significant in luminal A subtype. The combination of p53 and Ki-67 has been shown to have the best predictive power as calculated by the area under curve (AUC), especially for long-term overall survival. In this study, we have shown that overexpression of p53 and Ki-67 could be used to discriminate low-risk luminal A subtype in breast cancer. Therefore, using the combination of p53 and Ki-67 expression in discriminating low-risk luminal A breast cancer may improve the prognostic power and provide the greatest clinical utility. PMID:26241661

Distinguishing Low-Risk Luminal A Breast Cancer Subtypes with Ki-67 and p53 Is More Predictive of Long-Term Survival.

PubMed

Lee, Se Kyung; Bae, Soo Youn; Lee, Jun Ho; Lee, Hyun-Chul; Yi, Hawoo; Kil, Won Ho; Lee, Jeong Eon; Kim, Seok Won; Nam, Seok Jin

2015-01-01

Overexpression of p53 is the most frequent genetic alteration in breast cancer. Recently, many studies have shown that the expression of mutant p53 differs for each subtype of breast cancer and is associated with different prognoses. In this study, we aimed to determine the suitable cut-off value to predict the clinical outcome of p53 overexpression and its usefulness as a prognostic factor in each subtype of breast cancer, especially in luminal A breast cancer. Approval was granted by the Institutional Review Board of Samsung Medical Center. We analyzed a total of 7,739 patients who were surgically treated for invasive breast cancer at Samsung Medical Center between Dec 1995 and Apr 2013. Luminal A subtype was defined as ER&PR + and HER2- and was further subclassified according to Ki-67 and p53 expression as follows: luminal A (Ki-67-,p53-), luminal A (Ki-67+, p53-), luminal A (Ki-67 -, p53+) and luminal A (Ki-67+, p53+). Low-risk luminal A subtype was defined as negative for both Ki-67 and p53 (luminal A [ki-67-, p53-]), and others subtypes were considered to be high-risk luminal A breast cancer. A cut-off value of 10% for p53 was a good predictor of clinical outcome in all patients and luminal A breast cancer patients. The prognostic role of p53 overexpression for OS and DFS was only significant in luminal A subtype. The combination of p53 and Ki-67 has been shown to have the best predictive power as calculated by the area under curve (AUC), especially for long-term overall survival. In this study, we have shown that overexpression of p53 and Ki-67 could be used to discriminate low-risk luminal A subtype in breast cancer. Therefore, using the combination of p53 and Ki-67 expression in discriminating low-risk luminal A breast cancer may improve the prognostic power and provide the greatest clinical utility.

A Hessian-based methodology for automatic surface crack detection and classification from pavement images

NASA Astrophysics Data System (ADS)

Ghanta, Sindhu; Shahini Shamsabadi, Salar; Dy, Jennifer; Wang, Ming; Birken, Ralf

2015-04-01

Around 3,000,000 million vehicle miles are annually traveled utilizing the US transportation systems alone. In addition to the road traffic safety, maintaining the road infrastructure in a sound condition promotes a more productive and competitive economy. Due to the significant amounts of financial and human resources required to detect surface cracks by visual inspection, detection of these surface defects are often delayed resulting in deferred maintenance operations. This paper introduces an automatic system for acquisition, detection, classification, and evaluation of pavement surface cracks by unsupervised analysis of images collected from a camera mounted on the rear of a moving vehicle. A Hessian-based multi-scale filter has been utilized to detect ridges in these images at various scales. Post-processing on the extracted features has been implemented to produce statistics of length, width, and area covered by cracks, which are crucial for roadway agencies to assess pavement quality. This process has been realized on three sets of roads with different pavement conditions in the city of Brockton, MA. A ground truth dataset labeled manually is made available to evaluate this algorithm and results rendered more than 90% segmentation accuracy demonstrating the feasibility of employing this approach at a larger scale.