WorldWideScience

Sample records for pavement grooving

  1. Wet Weather Crater Repair Technologies for Grooved and Smooth Pavements

    Science.gov (United States)

    2018-04-30

    Dean Geotechnical and Structures Laboratory U.S. Army Engineer Research and Development Center 3909 Halls Ferry Road Vicksburg, MS 39180-6199...ORGANIZATION REPORT NUMBER U.S. Army Engineer Research and Development Center Geotechnical and Structures Laboratory 3909 Halls Ferry Road ...SUBJECT TERMS Crater Concrete Rain and rainfall ADR Grooved pavement Smooth pavement Runoff Runways (Aeronautics) – Maintenance and repair

  2. Effectiveness of noise barriers installed adjacent to transverse grooved concrete pavement : executive summary report.

    Science.gov (United States)

    2009-10-16

    In recent years the Ohio Department of Transportation (ODOT) has reconstructed a number of roadways where asphalt pavements were replaced with concrete pavements which were finished with a random transverse grooved surface texture (ODOT specification...

  3. Research on Grooved Concrete Pavement Based on the Durability of Its Anti-Skid Performance

    Directory of Open Access Journals (Sweden)

    Mulian Zheng

    2018-05-01

    Full Text Available The objectives of the present study are to investigate the anti-skid performance of concrete pavement and to attempt to enhance its durability by two different methods: using a longitudinally-transversely grooved (LT form, and using a self-developed composite curing agent containing paraffin and Na2SiO3 as the main ingredients. The friction coefficient (μ was measured by self-developed equipment to evaluate the anti-skid performance of samples with three different groove forms (LT, longitudinally grooved (L, and transversely grooved (T. Abrasion tests were then carried out to evaluate the durability of the anti-skid performance. The results indicated that anti-skid performance of LT samples was approximately 46.2% greater than that of T samples, but its durability was not as significant as that of T samples. However, the resistance to abrasion could be improved by using the aforementioned curing agent. Comparisons were carried out between samples sprayed the curing agent and control samples without any curing agent under standard conditions. It was found that the application of the curing agent increased the anti-skid durability of concrete by 35.4%~47.8%, proving it to be a useful and promising technique.

  4. Grooved cold moderator tests

    International Nuclear Information System (INIS)

    Inoue, K.; Kiyanagi, Y.; Iwasa, H.; Watanabe, N.; Ikeda, S.; Carpenter, J.M.; Ishikawa, Y.

    1983-01-01

    We performed some grooved cold moderator experiments for methane at 20 K by using the Hokkaido University linac to obtain information to be used in the planning of the KENS-I' project. Cold neutron gains, spatial distribution of emitted beams and time distribution of the neutrons in the grooved cold moderator were measured. Furthermore, we assessed the effects of the grooved cold moderator on the performances of the spectrometers presently installed at the KENS-I cold source. We concluded that the grooved cold moderator benefited appreciably the performances of the spectrometers

  5. Endosonography of groove pancreatitis

    NARCIS (Netherlands)

    Tio, T. L.; Luiken, G. J.; Tytgat, G. N.

    1991-01-01

    Groove pancreatitis is a rare form of chronic pancreatitis. Distinction between pancreatitis and pancreatic carcinoma is often difficult. Two cases of groove pancreatitis diagnosed by endosonography are described. A hypoechoic pattern between the duodenal wall and pancreas was clearly imaged in both

  6. First branchial groove anomaly.

    Science.gov (United States)

    Kumar, M; Hickey, S; Joseph, G

    2000-06-01

    First branchial groove anomalies are very rare. We report a case of a first branchial groove anomaly presented as an infected cyst in an 11-month-old child. Management of such lesions is complicated because of their close association with the facial nerve. Surgical management must include identification and protection of the facial nerve. Embryology and facial nerve disposition in relation to the anomaly are reviewed.

  7. EDM Electrode for Internal Grooves

    Science.gov (United States)

    Ramani, V.; Werner, A.

    1985-01-01

    Electroerosive process inexpensive alternative to broaching. Hollow brass electrodes, soldered at one end to stainless-steel holding ring, held in grooves in mandrel. These electrodes used to machine grooves electrically in stainless-steel tube three-eights inch (9.5 millimeters) in diameter. Tool used on tubes already in place in equipment.

  8. Room to Groove?

    DEFF Research Database (Denmark)

    Seabrooke, Leonard

    . As long as they stay within the parameters of legitimate financial practice to signal institutional isomorphism, the `groove', creditors may well allow borrowers room for change in self-determined ways. This paper maps out the historical and conceptual terrain concerning civilizing ideas about...... the legitimacy of financial practices within global capital markets, and investigates relationships between Western `civilizers' and Emerging Market Economies during the last two periods of financial globalization, the late-nineteenth/ early-twentieth centuries and the late-twentieth century.......The use of a `standard of civilization', a preferred form of socio-political organization, in global capital markets presents both constraints and opportunities for creditors and borrowers. When imposed, civilizing standards may change how a borrower would prefer to conduct their affairs. Creditors...

  9. Pavement Subgrade Performance Study

    DEFF Research Database (Denmark)

    Zhang, Wei; Ullidtz, Per; Macdonald, Robin

    1998-01-01

    The report describes the second test in the Danish Road Testing Machine (RTM) under the International Pavement Subgrade Performance Study. Pavement response was measured in different layers, and compared to different theroretical values. Performance in terms of plastic strains, rutting...

  10. Concrete pavement joint deterioration.

    Science.gov (United States)

    2015-12-01

    Concrete pavements are an important part of our national infrastructure. In recent years the relatively small number of reported joints deteriorating prematurely in concrete pavements around Indiana has increased. Changes over the past 45 years in IN...

  11. Permeable pavement study (Edison)

    Data.gov (United States)

    U.S. Environmental Protection Agency — While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types...

  12. Indiana Pavement Preservation Program

    OpenAIRE

    Ong, Ghim Ping (Raymond); Nantung, Tommy E.; Sinha, Kumares C.

    2010-01-01

    State highway agencies are facing immense pressure to maintain roads at acceptable levels amidst the challenging financial and economic situations. In recent years, pavement preservation has been sought as a potential alternative for managing the pavement assets, believing that it would provide a cost-effective solution in maintaining infrastructural conditions and meeting user expectations. This study explores the potential of pavement preservation concepts in managing the agency‘s pavement ...

  13. Olfactory groove meningiomas.

    Science.gov (United States)

    Hentschel, Stephen J; DeMonte, Franco

    2003-06-15

    Olfactory groove meningiomas (OGMs) arise over the cribriform plate and may reach very large sizes prior to presentation. They can be differentiated from tuberculum sellae meningiomas because OGMs arise more anterior in the skull base and displace the optic nerve and chiasm inferiorly rather than superiorly. The authors searched the neurosurgery database at the M. D. Anderson Cancer Center for cases of OGM treated between 1993 and 2003. The records of these patients were then reviewed retrospectively for details regarding clinical presentation, imaging findings, surgical results and complications, and follow-up status. Thirteen patients, (12 women and one man, mean age 56 years) harbored OGMs (mean size 5.7 cm). All patients underwent bifrontal craniotomies and biorbital osteotomies. There were 11 complete resections (including the hyperostotic bone and dura of the cribriform plate and any extension into the ethmoid sinuses) and two subtotal resections with minimal residual tumor left in patients with recurrent lesions. No complication directly due to the surgery occurred in any patient. There were no recurrences in a mean follow-up period of 2 years (range 0-5 years). With current microsurgical techniques, the results of OGM resection are excellent, with a high rate of total resection and a low incidence of complications. All hyperostotic bone should be removed with the dura of the anterior skull base to minimize the risk of recurrence.

  14. DNA minor groove alkylating agents.

    Science.gov (United States)

    Denny, W A

    2001-04-01

    Recent work on a number of different classes of anticancer agents that alkylate DNA in the minor groove is reviewed. There has been much work with nitrogen mustards, where attachment of the mustard unit to carrier molecules can change the normal patterns of both regio- and sequence-selectivity, from reaction primarily at most guanine N7 sites in the major groove to a few adenine N3 sites at the 3'-end of poly(A/T) sequences in the minor groove. Carrier molecules discussed for mustards are intercalators, polypyrroles, polyimidazoles, bis(benzimidazoles), polybenzamides and anilinoquinolinium salts. In contrast, similar targeting of pyrrolizidine alkylators by a variety of carriers has little effect of their patterns of alkylation (at the 2-amino group of guanine). Recent work on the pyrrolobenzodiazepine and cyclopropaindolone classes of natural product minor groove binders is also reviewed.

  15. Optics of multiple grooves in metal

    DEFF Research Database (Denmark)

    Skjølstrup, Enok Johannes Haahr; Søndergaard, Thomas; Pedersen, Kjeld

    2017-01-01

    This paper studies theoretically how the optics of multiple grooves in a metal change as the number of grooves is increased gradually from a single groove to innitely many arranged in a periodic array. In the case of a single groove the out-of-plane scattering (OUP) cross section at resonance can...

  16. Optics of multiple grooves in metal

    DEFF Research Database (Denmark)

    Skjølstrup, Enok Johannes Haahr; Søndergaard, Thomas; Pedersen, Kjeld

    2017-01-01

    This paper theoretically studies how the optics of multiple grooves in a metal change as the number of grooves gradually increased from a single groove to infinitely many arranged in a periodic array. In the case of a single groove, the out-of-plane scattering (OUP) cross section at resonance can...

  17. Consideration of pavement roughness effects on vehicle-pavement interaction

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2001-07-01

    Full Text Available . In this paper the focus is on quantification of the pavement roughness effects on the calculated structural pavement life and the effects of surfacing maintenance on the moving dynamic tyre loads generated by vehicles. A simplified method for calculating... the moving dynamic tyre load population is used together with standard pavement response analysis methods to quantify the effects of pavement surfacing maintenance on roughness and structural pavement life. This method can be used as a pavement management...

  18. State of the art: Asphalt for airport pavement surfacing

    Directory of Open Access Journals (Sweden)

    Greg White

    2018-01-01

    Full Text Available Airport runways and taxiways are commonly comprised of a flexible pavement with an asphalt surface. Marshall-designed asphalt with sawn grooves is the most frequent airport asphalt surface material. However, some airports have adopted alternate asphalt mixtures for improved resistance to shear stress and for increased surface texture, allowing grooving to be avoided. Of the alternate asphalt mixtures, stone mastic asphalt is the most commonly reported. Resistance to shear stress is a critical performance requirement for airport surface asphalt. Shear stress resistance minimises the risk of rutting, shoving and groove closure. However, fracture resistance must not be ignored when developing even more shear resistance asphalt mixtures. Significant distress in airport asphalt surfaces, compliant with the traditional prescriptive specification, has increased interest in a performance-based airport asphalt specification. Commonly reported distresses include groove closure in slow moving aircraft areas and shearing in heavy aircraft braking zones. Development of reliable performance-indicative test methods is expected in the future and will enable warranted performance-based asphalt mixture design for airport surfaces. Keywords: Airport, Pavement, Asphalt, Surface

  19. NASA diagonal-braked test vehicle evaluation of traction characteristics of grooved and ungrooved runway surfaces at Miami International Airport, Miami, Florida, 8-9 May 1973

    Science.gov (United States)

    Horne, W. B.

    1977-01-01

    Two runways were evaluated under artificially wetted conditions with the NASA diagonal-braked vehicle (DBV). Results of the evaluation which included a pavement drainage analysis, a pavement skid resistance analysis, and a DBV wet/dry stopping distance ratio analysis indicated that the ungrooved runway surfaces had poor water drainage characteristics and poor skid resistance under wet conditions at high speeds especially in rubbercoated areas of the runways. Grooving runways to a transverse 1-1/4 x 1/4 x 1/4 inch pattern greatly improved both the water drainage and pavement skid resistance capability of these asphaltic concrete surfaces.

  20. Pavement Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Comprehensive Environmental and Structural AnalysesThe ERDC Pavement Testing Facility, located on the ERDC Vicksburg campus, was originally constructed to provide an...

  1. Optics of multiple ultrasharp grooves in metal

    DEFF Research Database (Denmark)

    Skjølstrup, Enok Johannes Haahr; Søndergaard, Thomas

    2017-01-01

    . When the multiple-groove array is illuminated by a plane wave the out-of-plane scattering is found to be extraordinarily large compared with the expected maximum from a geometric-optics estimate even for array widths of many wavelengths. The out-of-plane scattering is even higher per groove compared......The optics of multiple ultrasharp sub-wavelength grooves in metal is studied theoretically. Focus is on the transition from a single groove, where the scattering cross section is significant and can exceed the groove width, to infinitely many grooves in a periodic array with very low reflectance...

  2. Asphalt in Pavement Maintenance.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

    Maintenance methods that can be used equally well in all regions of the country have been developed for the use of asphalt in pavement maintenance. Specific information covering methods, equipment and terminology that applies to the use of asphalt in the maintenance of all types of pavement structures, including shoulders, is provided. In many…

  3. Resistance to minor groove binders.

    Science.gov (United States)

    Colmegna, Benedetta; Uboldi, Sarah; Erba, Eugenio; D'Incalci, Maurizio

    2014-03-01

    In this paper multiple resistance mechanisms to minor groove binders (MGBs) are overviewed. MGBs with antitumor properties are natural products or their derivatives and, as expected, they are all substrates of P-glycoprotein (P-gp). However, a moderate expression of P-gp does not appear to reduce the sensitivity to trabectedin, the only MGB so far approved for clinical use. Resistance to this drug is often related to transcriptional mechanisms and to DNA repair pathways, particularly defects in transcription-coupled nucleotide excision repair (TC-NER). Therefore tumors resistant to trabectedin may become hypersensitive to UV rays and other DNA damaging agents acting in the major groove, such as Platinum (Pt) complexes. If this is confirmed in clinic, that will provide the rationale to combine trabectedin sequentially with Pt derivates.

  4. Pavement edge treatment.

    Science.gov (United States)

    2013-01-01

    Four projects were built over two construction seasons using special devices attached to the paving machine that produces a 30 slope on the outside pavement edge instead of the near vertical drop-off common with conventional paving equipment. This ...

  5. Pervious Pavement System Evaluation

    Science.gov (United States)

    Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, grade...

  6. Desert Pavement Studies

    National Research Council Canada - National Science Library

    Haff, Peter

    2003-01-01

    Combining plan view information from aerial photography showing details of stream channels on desert pavement surfaces with process-based erosion models, a high-resolution, synthetic topography DEM...

  7. Desert Pavement Studies

    National Research Council Canada - National Science Library

    Haff, P

    2003-01-01

    Combining plan view information from aerial photography showing details of stream channels on desert pavement surfaces with process-based erosion models, a high-resolution, "synthetic topography" DEM...

  8. Laser grooving of surface cracks on hot work tool steel

    Directory of Open Access Journals (Sweden)

    D. Klobčar

    2011-10-01

    Full Text Available The paper presents the analysis of laser grooving of 1.2343 tool steel hardened to 46 HRC. The effect of laser power and grooving speed on groove shape (i.e. depth and width, the material removal rate and the purity of produced groove as a measure of groove quality was investigated and analyzed using response surface methodology. Optimal parameters of laser grooving were found, which enables pure grooves suitable for laser welding.

  9. Differential diagnosis of groove pancreatic carcinomas vs. groove pancreatitis: Usefulness of the portal venous phase

    International Nuclear Information System (INIS)

    Ishigami, Kousei; Tajima, Tsuyoshi; Nishie, Akihiro; Kakihara, Daisuke; Fujita, Nobuhiro; Asayama, Yoshiki; Ushijima, Yasuhiro; Irie, Hiroyuki; Nakamura, Masafumi; Takahata, Shunichi; Ito, Tetsuhide; Honda, Hiroshi

    2010-01-01

    Purpose: To clarify if the portal venous phase is helpful for the differential diagnosis of groove pancreatic carcinomas and groove pancreatitis. Materials and methods: MDCT and MRI of groove pancreatic carcinomas (n = 7) and groove pancreatitis (n = 15) were retrospectively reviewed by two radiologists independently. The signal intensity on T2-weighted images was subjectively assessed. The presence or absence of common bile duct (CBD) and main pancreatic duct (MPD) strictures, calcifications, and cystic lesions was evaluated. Additionally, the appearance of groove pancreatic carcinoma and that of groove pancreatitis in the portal venous phase on dynamic MDCT and MRI were compared. Results: There were no significant differences in the signal intensity on T2-weighted images and in the presence or absence of CBD and MPD strictures, calcifications, and cystic lesions between groove pancreatic carcinomas and groove pancreatitis. However, patchy focal enhancement in the portal venous phase was more commonly observed in groove pancreatitis than groove pancreatic carcinoma (Reviewers 1 and 2: 14/15 [93.3%] vs. 1/7 [14.3%], P < 0.0001). In addition, peripheral enhancement was only seen in groove pancreatic carcinomas (Reviewer 1: 4/7 [57.1%] vs. 0/15 [0%], P < 0.005, and Reviewer 2: 3/7 [42.9%] vs. 0/15 [0%], P < 0.05). Conclusion: The portal venous phase may be helpful for the differential diagnosis of groove pancreatic carcinomas and groove pancreatitis.

  10. Training development for pavement preservation.

    Science.gov (United States)

    2013-05-01

    This research project strives to help the Iowa Department of Transportation (DOT) fully achieve the full benefits of pavement : preservation through training on proper selection, design, and application of pavement preservation treatments. In some ca...

  11. Alternative pavements for snowmobile crossings.

    Science.gov (United States)

    2009-09-01

    Excessive highway pavement wear from snowmobile traffic is a maintenance problem for the New Hampshire Department of : Transportation. The snowmobiles and trail grooming equipment scar and erode the pavement surfaces, eventually creating wide ruts ac...

  12. Status report on pavement management.

    Science.gov (United States)

    1984-01-01

    This report traces the developments in pavement management in the Virginia Department of Highways and Transportation from the initial efforts in the mid-1970s through early 1984. Included are status reports on pavement management for the interstate, ...

  13. Development of reliable pavement models.

    Science.gov (United States)

    2011-05-01

    The current report proposes a framework for estimating the reliability of a given pavement structure as analyzed by : the Mechanistic-Empirical Pavement Design Guide (MEPDG). The methodology proposes using a previously fit : response surface, in plac...

  14. Influence of musical groove on postural sway.

    Science.gov (United States)

    Ross, Jessica M; Warlaumont, Anne S; Abney, Drew H; Rigoli, Lillian M; Balasubramaniam, Ramesh

    2016-03-01

    Timescales of postural fluctuation reflect underlying neuromuscular processes in balance control that are influenced by sensory information and the performance of concurrent cognitive and motor tasks. An open question is how postural fluctuations entrain to complex environmental rhythms, such as in music, which also vary on multiple timescales. Musical groove describes the property of music that encourages auditory-motor synchronization and is used to study voluntary motor entrainment to rhythmic sounds. The influence of groove on balance control mechanisms remains unexplored. We recorded fluctuations in center of pressure (CoP) of standing participants (N = 40) listening to low and high groove music and during quiet stance. We found an effect of musical groove on radial sway variability, with the least amount of variability in the high groove condition. In addition, we observed that groove influenced postural sway entrainment at various temporal scales. For example, with increasing levels of groove, we observed more entrainment to shorter, local timescale rhythmic musical occurrences. In contrast, we observed more entrainment to longer, global timescale features of the music, such as periodicity, with decreasing levels of groove. Finally, musical experience influenced the amount of postural variability and entrainment at local and global timescales. We conclude that groove in music and musical experience can influence the neural mechanisms that govern balance control, and discuss implications of our findings in terms of multiscale sensorimotor coupling. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  15. Thermal Bridge Effects in Window Grooves

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    In this report thermal bridge effects in window grooves are analyzed. The analysis is performed using different thicknesses of the window groove insulation, to evaluate what the optimal solution is.All analysis in the report is performed using both 2- and 3-dimensional numerical analysis....

  16. Mixed convection in a baffled grooved channel

    Indian Academy of Sciences (India)

    MS received 16 May 2014; revised 19 October 2014; accepted 06 November 2014. Abstract. In the present numerical work, flow structure and heat transfer charac- teristics are investigated in a baffled grooved channel, differentially heated from the sides. The baffle is placed vertically downward from the top wall of grooved ...

  17. Spiral groove seal. [for rotating shaft

    Science.gov (United States)

    Ludwig, L. P.; Strom, T. N. (Inventor)

    1974-01-01

    Mating flat surfaces inhibit leakage of a fluid around a stationary shaft. A spiral groove produces a pumping action toward the fluid when the shaft rotates. This prevents leakage while a generated hydraulic lifting force separates the mating surfaces to minimize wear. Provision is made for placing these spiral grooves in communication with the fluid to accelerate the generation of the hydraulic lifting force.

  18. Dielectric image line groove antennas for millimeterwaves

    Science.gov (United States)

    Solbach, K.; Wolff, I.

    Grooves in the ground plane of dielectric image lines are proposed as a new radiating structure. A figure is included showing the proposed groove structure as a discontinuity in a dielectric image line. A wave incident on the dielectric image line is partly reflected by the discontinuity, partly transmitted across the groove, and partly radiated into space above the line. In a travelling-wave antenna, a number of grooves are arranged below a dielectric guide, with spacings around one guide wavelength to produce a beam in the upper half space. A prescribed aperture distribution can be effected by tapering the series radiation resistance of the grooves. This can be done by adjusting the depths of the grooves with a constant width or by varying the widths of the grooves with a constant depth. Attention is also given to circular grooves. Here, the widths of the holes are chosen so that they can be considered as waveguides operating far below the cut-off frequency of the fundamental circular waveguide mode.

  19. Pavement Snow Melting

    Energy Technology Data Exchange (ETDEWEB)

    Lund, John W.

    2005-01-01

    The design of pavement snow melting systems is presented based on criteria established by ASHRAE. The heating requirements depends on rate of snow fall, air temperature, relative humidity and wind velocity. Piping materials are either metal or plastic, however, due to corrosion problems, cross-linked polyethylene pipe is now generally used instead of iron. Geothermal energy is supplied to systems through the use of heat pipes, directly from circulating pipes, through a heat exchanger or by allowing water to flow directly over the pavement, by using solar thermal storage. Examples of systems in New Jersey, Wyoming, Virginia, Japan, Argentina, Switzerland and Oregon are presented. Key words: pavement snow melting, geothermal heating, heat pipes, solar storage, Wyoming, Virginia, Japan, Argentina, Klamath Falls.

  20. The investigation of groove geometry effect on heat transfer for internally grooved tubes

    International Nuclear Information System (INIS)

    Bilen, Kadir; Cetin, Murat; Gul, Hasan; Balta, Tuba

    2009-01-01

    An experimental study of surface heat transfer and friction characteristics of a fully developed turbulent air flow in different grooved tubes is reported. Tests were performed for Reynolds number range 10,000-38,000 and for different geometric groove shapes (circular, trapezoidal and rectangular). The ratio of tube length-to-diameter is 33. Among the grooved tubes, heat transfer enhancement is obtained up to 63% for circular groove, 58% for trapezoidal groove and 47% for rectangular groove, in comparison with the smooth tube at the highest Reynolds number (Re = 38,000). Correlations of heat transfer and friction coefficient were obtained for different grooved tubes. In evaluation of thermal performance, it is seen that the grooved tubes are thermodynamically advantageous (Ns, a < 1) up to Re = 30,000 for circular and trapezoidal grooves and up to Re = 28,000 for rectangular grooves. It is observed that there is an optimum value of the entropy generation number at about Re = 17,000 for all investigated grooves

  1. Experimental pavement delineation treatments

    Science.gov (United States)

    Bryden, J. E.; Lorini, R. A.

    1981-06-01

    Visibility and durability of materials used to delineate shoulders and medians adjacent to asphalt pavements were evaluated. Materials evaluated were polysulfide and coal tar epoxies, one and two component polyesters, portland cement, acrylic paints, modified-alkyd traffic paint, preformed plastic tape, and thermoplastic markings. Neat applications, sand mortars, and surface treatments were installed in several geometric patterns including cross hatches, solid median treatments, and various widths of edge lines. Thermoplastic pavement markings generally performed very well, providing good visibility under adverse viewing conditions for at least 4 years. Thermoplastic 4 in. wide edge lines appear to provide adequate visibility for most conditions.

  2. Modified pavement cement concrete

    Science.gov (United States)

    Botsman, L. N.; Ageeva, M. S.; Botsman, A. N.; Shapovalov, S. M.

    2018-03-01

    The paper suggests design principles of pavement cement concrete, which covers optimization of compositions and structures at the stage of mixture components selection due to the use of plasticizing agents and air-retaining substances that increase the viability of a concrete mixture. It also demonstrates advisability of using plasticizing agents together with air-retaining substances when developing pavement concrete compositions, which provides for the improvement of physical and mechanical properties of concrete and the reduction of cement binding agent consumption thus preserving strength indicators. The paper shows dependences of the main physical-mechanical parameters of concrete on cement consumption, a type and amount of additives.

  3. Fatigue cracking in road pavement

    Science.gov (United States)

    Mackiewicz, P.

    2018-05-01

    The article presents the problem of modelling fatigue phenomena occurring in the road pavement. The example of two selected pavements shows the changes occurring under the influence of the load in different places of the pavement layers. Attention is paid to various values of longitudinal and transverse strains generated at the moment of passing the wheel on the pavement. It was found that the key element in the crack propagation analysis is the method of transferring the load to the pavement by the tire and the strain distribution in the pavement. During the passage of the wheel in the lower layers of the pavement, a complex stress state arises. Then vertical, horizontal and tangent stresses with various values appear. The numerical analyses carried out with the use of finite element methods allowed to assess the strain and stress changes occurring in the process of cracking road pavement. It has been shown that low-thickness pavements are susceptible to fatigue cracks arising "bottom to top", while pavements thicker are susceptible to "top to bottom" cracks. The analysis of the type of stress allowed to determine the cracking mechanism.

  4. Pavement Performance : Approaches Using Predictive Analytics

    Science.gov (United States)

    2018-03-23

    Acceptable pavement condition is paramount to road safety. Using predictive analytics techniques, this project attempted to develop models that provide an assessment of pavement condition based on an array of indictors that include pavement distress,...

  5. Optimization and standardization of pavement management processes.

    Science.gov (United States)

    2004-08-01

    This report addresses issues related to optimization and standardization of current pavement management processes in Kentucky. Historical pavement management records were analyzed, which indicates that standardization is necessary in future pavement ...

  6. A guide for local agency pavement managers

    Science.gov (United States)

    1994-12-01

    The purpose of this guide is to provide Washington's local agencies with a practical document that will assist pavement managers in understanding the pavement management process and the steps necessary to implement their own pavement management syste...

  7. Experimental Studies on Grooved Double Pipe Heat Exchanger with Different Groove Space

    Science.gov (United States)

    Sunu, P. W.; Arsawan, I. M.; Anakottapary, D. S.; Santosa, I. D. M. C.; Yasa, I. K. A.

    2018-01-01

    Experimental studies were performed on grooved double pipe heat exchanger (DPHE) with different groove space. The objective of this work is to determine optimal heat transfer parameter especially logarithmic mean temperature difference (LMTD). The document in this paper also provides the total heat observed by the cold fluid. The rectangular grooves were incised on outer surface of tube side with circumferential pattern and two different grooves space, namely 1 mm and 2 mm. The distance between grooves and the grooves high were kept constant, 8 mm and 0.3 mm respectively. The tube diameter is 20 mm and its made of aluminium. The shell is made of acrylic which has 28 mm in diameter. Water is used as the working fluid. Using counter flow scheme, the cold fluid flows in the annulus room of DPHE. The volume flowrate of hot fluid remains constant at 15 lpm. The volume flowrate of cold fluid were varied from 11 lpm to 15 lpm. Based on logarithmic mean temperature difference analysis, the LMTD of 1 mm grooves space was higher compared to that of 2 mm grooves space. The smaller grooves space has more advantage since the recirculating region are increased which essentially cause larger heat transfer enhancement.

  8. Geotextiles in Flexible Pavement Construction

    Science.gov (United States)

    Alungbe, Gabriel D.

    2004-01-01

    People everywhere in the developed world regularly drive on paved roads. Learning about the construction techniques and materials used in paving benefits technology and construction students. This article discusses the use of geosynthetic textiles in pavement construction. It presents background on pavements and describes geotextiles and drainage…

  9. Evaluation of airfield pavement evenness

    Science.gov (United States)

    Pietruszewski, Paweł; Poświata, Adam; Wesołowski, Mariusz

    2018-05-01

    The evenness of airfield pavements is one of the basic operating parameters, which characterize them. The evenness determines not only comfort of traffic along an airfield pavement, but also influences the size of dynamic effect on the pavement, hence, the safety of air operations. In addition, the evenness condition changing as a result of dynamic loads, adverse weather conditions or inappropriate airfield pavement construction technology, lead to deviations from the desired condition in the form of longitudinal and transverse unevenness. As a result, systematic and correct performance of tests is a very significant and required factor impacting the improvement of traffic safety on airfield pavements. If the data obtained through the measurements are not sufficiently reliable, they may consequently lead to making incorrect decisions, which can ultimately impact the safety of air operations.

  10. Pavement maintenance scheduling using genetic algorithms

    OpenAIRE

    Yang, Chao; Remenyte-Prescott, Rasa; Andrews, John D.

    2015-01-01

    This paper presents a new pavement management system (PMS) to achieve the optimal pavement maintenance and rehabilitation (M&R) strategy for a highway network using genetic algorithms (GAs). Optimal M&R strategy is a set of pavement activities that both minimise the maintenance cost of a highway network and maximise the pavement condition of the road sections on the network during a certain planning period. NSGA-II, a multi-objective GA, is employed to perform pavement maintenance optimisatio...

  11. Local-scale stratigraphy of grooved terrain on Ganymede

    Science.gov (United States)

    Murchie, Scott L.; Head, James W.; Helfenstein, Paul; Plescia, Jeffrey B.

    1987-01-01

    The surface of the Jovian satellite, Ganymede, is divided into two main units, dark terrain cut by arcuate and subradial furrows, and light terrain consisting largely of areas with pervasive U-shaped grooves. The grooved terrain may be subdivided on the basis of pervasive morphology of groove domains into four terrain types: (1) elongate bands of parallel grooves (groove lanes); (2) polygonal domains of parallel grooves (grooved polygons); (3) polygonal domains of two orthogonal groove sets (reticulate terrain); and (4) polygons having two to several complexly cross-cutting groove sets (complex grooved terrain). Reticulate terrain is frequently dark and not extensively resurfaced, and grades to a more hummocky terrain type. The other three grooved terrain types have almost universally been resurfaced by light material during their emplacement. The sequence of events during grooved terrain emplacement has been investigated. An attempt is made to integrate observed geologic and tectonic patterns to better constrain the relative ages and styles of emplacement of grooved terrain types. A revised model of grooved terrain emplacement is proposed and is tested using detailed geologic mapping and measurement of crater density.

  12. Accelerated pavement testing of thin RCC over soil cement pavements

    Directory of Open Access Journals (Sweden)

    Zhong Wu

    2016-05-01

    Full Text Available Three full-scale roller compacted concrete (RCC pavement sections built over a soil cement base were tested under accelerated pavement testing (APT. The RCC thicknesses varied from 102 mm (4 in. to 152 mm (6 in. and to 203 mm (8 in., respectively. A bi-directional loading device with a dual-tire load assembly was used for this experiment. Each test section was instrumented with multiple pressure cells and strain gages. The objective was to evaluate the structural performance and load carrying capacity of thin RCC-surfaced pavements under accelerated loading. The APT results generally indicated that all three RCC pavement sections tested in this study possessed very high load carrying capacity; an estimated pavement life in terms of equivalent single axle load (ESAL for the thinnest RCC section (i.e., RCC thickness of 102 mm evaluated was approximately 19.2 million. It was observed that a fatigue failure would be the primary pavement distress type for a thin RCC pavement under trafficking. Specifically, the development of fatigue cracking was found to originate from a longitudinal crack at the edge or in the center of a tire print, then extended and propagated, and eventually merged with cracks of other directions. Instrumentation results were used to characterize the fatigue damage under different load magnitudes. Finally, based on the APT performance of this experiment, two fatigue models for predicting the fatigue life of thin RCC pavements were developed. Keywords: Roller compacted concrete, APT, Pavement performance, Non-destructive testing, Fatigue analysis

  13. Graphene Plasmons in Triangular Wedges and Grooves

    DEFF Research Database (Denmark)

    Gonçalves, P. A. D.; Dias, E. J. C.; Xiao, Sanshui

    2016-01-01

    and tunability of graphene plasmons guided along the apex of a graphene-covered dielectric wedge or groove. In particular, we present a quasi-analytic model to describe the plasmonic eigenmodes in such a system, including the complete determination of their spectrum and corresponding induced potential...... and electric-field distributions. We have found that the dispersion of wedge/groove graphene plasmons follows the same functional dependence as their flat-graphene plasmon counterparts, but now scaled by a (purely) geometric factor in which all the information about the system’s geometry is contained. We...

  14. Nondestructive testing of pavements and pavement bases (a bibliography with abstracts). Report for 1964--Dec 1975

    International Nuclear Information System (INIS)

    Habercom, G.E. Jr.

    1976-02-01

    Eighty references on nondestructive methods for quality assurance of pavements and pavement bases are presented. Vibration, nuclear activation, radiometry, and acoustic detection are among the various techniques employed

  15. Spiral groove seal. [for hydraulic rotating shaft

    Science.gov (United States)

    Ludwig, L. P. (Inventor)

    1973-01-01

    Mating flat surfaces inhibit leakage of a fluid around a stationary shaft. A spiral groove pattern produces a pumping action toward the fluid when the shaft rotates which prevents leakage while a generated hydraulic lifting force separates the mating surfaces to minimize wear.

  16. Optimization of Grooved Micromixer for Microengineering Technologies

    DEFF Research Database (Denmark)

    Sabotin, I.; Tristo, G.; Bissacco, Giuliano

    2013-01-01

    Due to the absence of turbulent flow and the slow diffusion process, mixing of solutions at micro-scale is a difficult task. This paper describes the optimization route towards the efficient design of a bottom grooved micromixer. Based on thoroughly discussed mixing mechanisms, the optimization w...

  17. Appraisal of transverse nasal groove: a study.

    Science.gov (United States)

    Sathyanarayana, Belagola D; Basavaraj, Halevoor B; Nischal, Kuchangi C; Swaroop, Mukunda R; Umashankar, Puttagangu N; Agrawal, Dhruv P; Swamy, Suchetha S; Okram, Sarda

    2012-01-01

    Transverse nasal groove is a condition of cosmetic concern which awaits due recognition and has been widely described as a shallow groove that extends transversely over the dorsum of nose. However, we observed variations in the clinical presentations of this entity, hitherto undescribed in literature. We conducted a clinicoepidemiological study of transverse nasal lesions in patients attending our outpatient department. We conducted a prospective observational study. We screened all patients attending our out-patient department for presence of transverse nasal lesions, signs of any dermatosis and associated other skin conditions. One hundred patients were recruited in the study. Females (80%) predominated over males. Most patients were of 15-45 years age group (70%). Majority of the transverse nasal lesions were classical transverse nasal groove (39%) and others included transverse nasal line (28%), strip (28%), ridge (4%) and loop (1%). Seborrhoeic diathesis was the most common condition associated with transverse nasal lesion. Occurrence of transverse nasal line, strip, ridge and loop, in addition to classical transverse nasal groove implies that latter is actually a subset of transverse nasal lesions. Common association of this entity with seborrheic dermatitis, seborrhea and dandruff raises a possibility of whether transverse nasal lesion is a manifestation of seborrheic diathesis.

  18. Tire-Pavement Friction Characteristics with Elastic Properties of Asphalt Pavements

    Directory of Open Access Journals (Sweden)

    Miao Yu

    2017-11-01

    Full Text Available The skid-resisting performance of pavement is a critical factor in traffic safety. Recent studies primarily analyze this behavior by examining the macro or micro texture of the pavement. It is inevitable that skid-resistance declines with time because the texture of pavement deteriorates throughout its service life. The primary objective of this paper is to evaluate the use of different asphalt pavements, varying in resilience, to optimize braking performance on pavement. Based on the systematic dynamics of tire-pavement contact, and analysis of the tire-road coupled friction mechanism and the effect of enlarging the tire-pavement contact area, road skid resistance was investigated by altering the elastic modulus of asphalt pavement. First, this research constructed the kinetic contact model to simulate tire-pavement friction. Next, the following aspects of contact behaviors were studied when braking: tread deformation in the tangential pavement interface, actual tire-pavement contact in the course, and the frictional braking force transmitted from the pavement to the tires. It was observed that with improvements in pavement elasticity, the actual tire-pavement contact area increased, which gives us the ability to effectively strengthen the frictional adhesion of the tire to the pavement. It should not be overlooked that the improvement in skid resistance was caused by an increase in pavement elasticity. This research approach provides a theoretical basis and design reference for the anti-skid research of asphalt pavements.

  19. Intentional replantation: A viable alternative for management of palatogingival groove

    OpenAIRE

    Vijay Kumar; Ajay Logani; Naseem Shah

    2013-01-01

    Radicular groove is an anatomical malformation that often leads to combined endodontic-periodontic lesions. Treatment of complex groove presents a clinical challenge to the operator. A case of type III palatogingival groove is successfully treated with intentional replantation. With the understanding of the procedure and strict adherence to guidelines improves, practitioners can use intentional replantation as an easy and cost-effective alternative for the management of radicular groove. The ...

  20. Extending the Service Life of Pavements

    Science.gov (United States)

    Gschwendt, Ivan

    2018-03-01

    The cost of road construction and expenditures on the maintenance of pavements, i.e., their whole life cost, represents a lot of money. The paper describes a procedure for a pavement management system with degradation models and estimates the length of time for the rehabilitation of an asphalt pavement. Using a theory of pavement mechanics, we calculated the stresses and strains on the layers of two pavement models. High modulus asphalt concrete, an asphalt mix with a high binder content, and an asphalt mix with binder modifications are new road building materials. Prolonging the time for the rehabilitation of pavements is possible.

  1. Pervious Pavement System Evaluation- Abstract

    Science.gov (United States)

    Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, gra...

  2. Intentional replantation: A viable alternative for management of palatogingival groove

    Directory of Open Access Journals (Sweden)

    Vijay Kumar

    2013-01-01

    Full Text Available Radicular groove is an anatomical malformation that often leads to combined endodontic-periodontic lesions. Treatment of complex groove presents a clinical challenge to the operator. A case of type III palatogingival groove is successfully treated with intentional replantation. With the understanding of the procedure and strict adherence to guidelines improves, practitioners can use intentional replantation as an easy and cost-effective alternative for the management of radicular groove. The paper presents a brief review of palatogingival groove and highlights an easy and predictable alternative for its management.

  3. Quantifying Evaporation in a Permeable Pavement System

    Science.gov (United States)

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. Th...

  4. Dynamic contracting mechanism for pavement maintenance management

    NARCIS (Netherlands)

    Demirel, H.C.; De Ridder, H.A.J.

    2013-01-01

    Technological advances, financial possibilities and changes of demands have increasingly affected the pavement maintenance environment for outsourcing in recent years. This induces complexity in the contracting methods of pavement maintenance activities. Despite the fact that current contracting

  5. Equivalent damage of loads on pavements

    CSIR Research Space (South Africa)

    Prozzi, JA

    2009-05-26

    Full Text Available This report describes a new methodology for the determination of Equivalent Damage Factors (EDFs) of vehicles with multiple axle and wheel configurations on pavements. The basic premise of this new procedure is that "equivalent pavement response...

  6. Pavement performance evaluation, phase II : data collection.

    Science.gov (United States)

    2008-12-01

    Phase I and II of this study tested approximately 1500 rehabilitated pavements (asphalt and PCC) : throughout the State. These pavements ranged from 5 to 15 years old and were intended to develop a : snapshot of how various rehabilitations were perfo...

  7. Sustainable concrete pavements : a manual of practice.

    Science.gov (United States)

    2011-08-01

    Developed as a more detailed follow-up to a 2009 briefing document, Building Sustainable Pavement with Concrete, this guide provides a clear, concise, and cohesive discussion of pavement sustainability concepts and of recommended practices for maximi...

  8. Inverted base pavements: construction and performance

    KAUST Repository

    Papadopoulos, Efthymios; Santamarina, Carlos

    2017-01-01

    quality control. This study reviews the extensive South African experience and case histories in the USA. Accumulating evidence suggests that inverted base pavements are a viable alternative and can outperform conventional pavements at a lower cost

  9. An approach to pavement management in Virginia.

    Science.gov (United States)

    1981-01-01

    The report summarizes the objectives and benefits of formal pavement management systems and outlines an approach believed by the author to be practical for Virginia. The management of Virginia interstate pavements and a proposed random-sampling plan ...

  10. Calibration of PMIS pavement performance prediction models.

    Science.gov (United States)

    2012-02-01

    Improve the accuracy of TxDOTs existing pavement performance prediction models through calibrating these models using actual field data obtained from the Pavement Management Information System (PMIS). : Ensure logical performance superiority patte...

  11. Appraisal of the Causes of Pavement

    African Journals Online (AJOL)

    pavement failure) or structural (deep-seated pavement failure). ... is primarily due to shallow groundwater level. Adewole et al. ... processing and interpretation of Landsat-7 ETM+ images covering the study area and it's environ for lineaments.

  12. Serviceable pavement marking retroreflectivity levels : technical report.

    Science.gov (United States)

    2009-03-01

    This research addressed an array of issues related to measuring pavement markings retroreflectivity, factors : related to pavement marking performance, subjective evaluation process, best practices for using mobile : retroreflectometers, sampling pav...

  13. Deterioration of jointed Portland cement concrete pavements.

    Science.gov (United States)

    1975-01-01

    Information has been gathered regarding the performance of more than 400 lane-miles of jointed PCC interstate pavements located in five construction districts in Virginia. The factors causing pavement deterioration have been identified, the processes...

  14. Tire-Pavement Friction Characteristics with Elastic Properties of Asphalt Pavements

    OpenAIRE

    Miao Yu; Guoxiong Wu; Lingyun Kong; Yu Tang

    2017-01-01

    The skid-resisting performance of pavement is a critical factor in traffic safety. Recent studies primarily analyze this behavior by examining the macro or micro texture of the pavement. It is inevitable that skid-resistance declines with time because the texture of pavement deteriorates throughout its service life. The primary objective of this paper is to evaluate the use of different asphalt pavements, varying in resilience, to optimize braking performance on pavement. Based on the systema...

  15. Trabectedin – the DNA minor groove binder

    Directory of Open Access Journals (Sweden)

    G. A. Belitsky

    2015-01-01

    Full Text Available Trabectedin (ET-743, Yondelis is an alkaloid that was originally isolated from the Caribbean Sea squirt, Ecteinascidia turbinata and is now produced synthetically. Its chemical structure consists in three fused tetrahydroisoquinoline rings. Two of them, A and B, binds covalently to guanine residues in the minor groove of the DNA double helix to bend the molecule toward the major groove and the third ring C protrudes from the DNA duplex, apparently allowing interactions with several nuclear proteins. Binding to the minor groove of DNA, trabectedin trigger a cascade of events that interfere with several transcription factors, DNA binding proteins, and DNA repair pathways in particular nucleotide excision repair. It acts both as a DNA-alkylating drug and topoisomerase poison. Trabectedin-DNA adduct traps the nucleotide excision repair proteins repairing the DNA damage in transcribing genes and induces DNA strand breaks. Cells deficient in homologous recombination pathway which repairs these double-strand breaks show increased sensitivity to trabectedin. The most sensitive of them were myxoid liposarcomas. Trabectedin is also effective in chemotherapy-experienced patients with advanced, recurrent liposarcoma or leiomyosarcoma as well as in women with ovarian cancer and breast cancer with BRCAness phenotype. Besides of tumor cells Trabectedin inhibits inflammatory cells by affecting directly monocytes and tumorassociated macrophages and indirectly by inhibiting production of inflammatory mediators, the cytokines and chemokines. It inhibits also the MDR-1 gene, which is responsible for the resistance of cancer cells to chemotherapeutic agents and strikes tumor angiogenesis.

  16. Labiogingival groove: A rare developmental tooth anomaly

    Directory of Open Access Journals (Sweden)

    Shiva Chauhan

    2017-01-01

    Full Text Available Labiogingival groove is a congenital morphologic dental anomaly, in which an infolding of the inner enamel epithelium and Hertwig's epithelial root sheath create a groove extending varying depth into root. Epithelial attachment can be breached by gingival irritation secondary to plaque accumulation creating a periodontal defect that spreads to the pulp causing primary periodontal/secondary endodontic. A 12-year-old boy reported with the complaint of painful tooth with pus discharge from labial gingival surface in the maxillary right lateral incisor for 4 months. Intraoral examination revealed bluish red gingiva with loss of contour in relation to maxillary right lateral incisor and purulent discharge in relation to it. A provisional diagnosis of localized gingival abscess in relation to maxillary right incisor (primary periodontic and secondary endodontic involvement was given, and required treatment was carried out. On exposure of the involved tooth, a labiogingival groove was noticed which could have been a contributing factor for the progression of the condition.

  17. Impact of pavement conditions on crash severity.

    Science.gov (United States)

    Li, Yingfeng; Liu, Chunxiao; Ding, Liang

    2013-10-01

    Pavement condition has been known as a key factor related to ride quality, but it is less clear how exactly pavement conditions are related to traffic crashes. The researchers used Geographic Information System (GIS) to link Texas Department of Transportation (TxDOT) Crash Record Information System (CRIS) data and Pavement Management Information System (PMIS) data, which provided an opportunity to examine the impact of pavement conditions on traffic crashes in depth. The study analyzed the correlation between several key pavement condition ratings or scores and crash severity based on a large number of crashes in Texas between 2008 and 2009. The results in general suggested that poor pavement condition scores and ratings were associated with proportionally more severe crashes, but very poor pavement conditions were actually associated with less severe crashes. Very good pavement conditions might induce speeding behaviors and therefore could have caused more severe crashes, especially on non-freeway arterials and during favorable driving conditions. In addition, the results showed that the effects of pavement conditions on crash severity were more evident for passenger vehicles than for commercial vehicles. These results provide insights on how pavement conditions may have contributed to crashes, which may be valuable for safety improvement during pavement design and maintenance. Readers should notice that, although the study found statistically significant effects of pavement variables on crash severity, the effects were rather minor in reality as suggested by frequency analyses. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Pavement noise measurements in Poland

    Science.gov (United States)

    Zofka, Ewa; Zofka, Adam; Mechowski, Tomasz

    2017-09-01

    The objective of this study is to investigate the feasibility of the On-Board Sound Intensity (OBSI) system to measure tire-pavement noise in Poland. In general, sources of noise emitted by the modern vehicles are the propulsion noise, aerodynamic resistance and noise generated at the tire-pavement interface. In order to capture tire-pavement noise, the OBSI system uses a noise intensity probe installed in the close proximity of that interface. In this study, OBSI measurements were performed at different types of pavement surfaces such as stone mastic asphalt (SMA), regular asphalt concrete (HMA) as well as Portland cement concrete (PCC). The influence of several necessary OBSI measurement conditions were recognized as: testing speed, air temperature, tire pressure and tire type. The results of this study demonstrate that the OBSI system is a viable and robust tool that can be used for the quality evaluation of newly built asphalt pavements in Poland. It can be also applied to generate reliable input parameters for the noise propagation models that are used to assess the environmental impact of new and existing highway corridors.

  19. Geo synthetic-reinforced Pavement systems

    International Nuclear Information System (INIS)

    Zornberg, J. G.

    2014-01-01

    Geo synthetics have been used as reinforcement inclusions to improve pavement performance. while there are clear field evidence of the benefit of using geo synthetic reinforcements, the specific conditions or mechanisms that govern the reinforcement of pavements are, at best, unclear and have remained largely unmeasured. Significant research has been recently conducted with the objectives of: (i) determining the relevant properties of geo synthetics that contribute to the enhanced performance of pavement systems, (ii) developing appropriate analytical, laboratory and field methods capable of quantifying the pavement performance, and (iii) enabling the prediction of pavement performance as a function of the properties of the various types of geo synthetics. (Author)

  20. ICP experiments more durable pavements

    International Nuclear Information System (INIS)

    Carta Petrolera

    1994-01-01

    A new asphalts technology that will make more durable the pavement in the highways and roads of the cities of Colombia investigates the Colombian Institute of the Petroleum ICP. The project that will have important incidence in the solution of one of the main problems in the roads of cities like Bogota, is only one of the 35 investigation programs and application of new technologies that with relationship to the sector of the hydrocarbons and its influence branches the ICP advances. The investigation looks for to elevate the current average of useful life of the pavements, with that it would be reached a standard that has the developed countries in this field

  1. [Microsurgical removal of olfactory groove meningiomas].

    Science.gov (United States)

    Liang, Ri-Sheng; Zhou, Liang-Fu; Mao, Ying; Zhang, Rong; Yang, Wei-Zhong

    2011-01-01

    To explore an effective method for further improving the surgical results of treatment of olfactory groove meningiomas. Sixty seven cases of olfactory groove meningiomas were treated by microneurosurgery, among which fifty seven were de novo cases, eight were recurrent tumors and the other two re-recurrent cases. Modified Derome approach was used in 12 cases, bilateral subfrontal approach in 28 cases, modified pterional approach in 21 cases and unilateral subfrontal approach in six cases. Tumors were resected microsurgically with radical removal of invaded dura, bone, and paranasal sinus mucosa. Reconstruction was performed in patients with skull base defect. Simpson grade I removal was accomplished in 59 cases, grade II in seven cases and grade IV in one case. Among 57 patients with de novo tumor, Simpson I resection was accomplished in 54 cases. Postoperative rhinorrhea and intracranial infection occurred in one case and was cured after temporal lumbar CSF drainage and antibiotic therapy. Two patients (2.9%) died within one month after operation, i.e.one aged patient of heart failure and the other of severe hypothalamus complication. Forty seven patients (72.3%) were followed up from one to ten years with an average of five years and four months. With the exception of two cases died, among the alive 45 patients, there were only three patients with tumor recurrence, which had undergone Simpson II or IV tumor resection. No recurrence was found in cases with Simpson I tumor removal. Previous blurred vision was not improved in three patients, hemiparalysis in two patients, and the other patients recovered well, resuming previous jobs or being able to take care themselves. Total tumor removal (Simpson I) should be the surgical goal for treatment of olfactory groove meningiomas, especially for de novo cases. An appropriate approach is fundamental in the effort to remove an OGM totally. Appropriate anterior skull base reconstruction with vascularized material is

  2. Teaching Methodology of Flexible Pavement Materials and Pavement Systems

    Science.gov (United States)

    Mehta, Yusuf; Najafi, Fazil

    2004-01-01

    Flexible pavement materials exhibit complex mechanical behavior, in the sense, that they not only show stress and temperature dependency but also are sensitive to moisture conditions. This complex behavior presents a great challenge to the faculty in bringing across the level of complexity and providing the concepts needed to understand them. The…

  3. Laser Surface Hardening of Groove Edges

    Science.gov (United States)

    Hussain, A.; Hamdani, A. H.; Akhter, R.; Aslam, M.

    2013-06-01

    Surface hardening of groove-edges made of 3Cr13 Stainless Steel has been carried out using 500 W CO2 laser with a rectangular beam of 2.5×3 mm2. The processing speed was varied from 150-500 mm/min. It was seen that the hardened depth increases with increase in laser interaction time. A maximum hardened depth of around 1mm was achieved. The microhardness of the transformed zone was 2.5 times the hardness of base metal. The XRD's and microstructural analysis were also reported.

  4. Syncopation, body-movement and pleasure in groove music.

    OpenAIRE

    Witek, MA; Clarke, EF; Wallentin, M; Kringelbach, ML; Vuust, P

    2014-01-01

    Moving to music is an essential human pleasure particularly related to musical groove. Structurally, music associated with groove is often characterised by rhythmic complexity in the form of syncopation, frequently observed in musical styles such as funk, hip-hop and electronic dance music. Structural complexity has been related to positive affect in music more broadly, but the function of syncopation in eliciting pleasure and body-movement in groove is unknown. Here we report results from a ...

  5. Dual-phase CT findings of groove pancreatitis

    Energy Technology Data Exchange (ETDEWEB)

    Zaheer, Atif, E-mail: azaheer1@jhmi.edu [The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Pancreatitis Center, Division of Gastroenterology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Haider, Maera, E-mail: mhaider3@jhmi.edu [The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Kawamoto, Satomi, E-mail: skawamo1@jhmi.edu [The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Hruban, Ralph H., E-mail: rhruban1@jhmi.edu [Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, the Johns Hopkins University School of Medicine, Baltimore, MD 21231 (United States); Fishman, Elliot K., E-mail: efishma1@jhmi.edu [The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States)

    2014-08-15

    Purpose: Groove pancreatitis is a rare focal form of chronic pancreatitis that occurs in the pancreaticoduodenal groove between the major and minor papillae, duodenum and pancreatic head. Radiologic appearance and clinical presentation can result in suspicion of malignancy rendering pancreaticoduodenectomy inevitable. This study reports dual phase CT findings in a series of 12 patients with pathology proven groove pancreatitis. Materials and methods: Retrospective review of preoperative CT findings in 12 patients with histologically proven groove pancreatitis after pancreaticoduodenectomy. Size, location, attenuation, presence of mass or cystic components in the pancreas, groove and duodenum, calcifications, duodenal stenosis and ductal changes were recorded. Clinical data, laboratory values, endoscopic ultrasonographic and histopathological findings were collected. Results: Soft tissue thickening in the groove was seen in all patients. Pancreatic head, groove and duodenum were all involved in 75% patients. A discrete lesion in the pancreatic head was seen in half of the patients, most of which appeared hypodense on both arterial and venous phases. Cystic changes in pancreatic head were seen in 75% patients. Duodenal involvement was seen in 92% patients including wall thickening and cyst formation. The main pancreatic duct was dilated in 7 patients, with an abrupt cut off in 3 and a smooth tapering stricture in 4. Five patients had evidence of chronic pancreatitis with parenchymal calcifications. Conclusion: Presence of mass or soft tissue thickening in the groove with cystic duodenal thickening is highly suggestive of groove pancreatitis. Recognizing common radiological features may help in diagnosis and reduce suspicion of malignancy.

  6. Wetting morphologies and their transitions in grooved substrates

    Energy Technology Data Exchange (ETDEWEB)

    Seemann, Ralf; Bommer, Stefan; Herrmann, Carsten; Michler, Dominik [Experimental Physics, Saarland University, D-66123 Saarbruecken (Germany); Brinkmann, Martin; Herminghaus, Stephan; Khare, Krishnacharya; Kostourou, Konstantina; Gurevich, Evgeny [Max Planck Institute for Dynamics and Self-Organization, D-37073 Goettingen (Germany); Law, Bruce M; McBride, Sean, E-mail: r.seemann@physik.uni-saarland.de [Department of Physics, Kansas State University, Manhattan, KS 66506 (United States)

    2011-05-11

    When exposed to a partially wetting liquid, many natural and artificial surfaces equipped with complex topographies display a rich variety of liquid interfacial morphologies. In the present article, we focus on a few simple paradigmatic surface topographies and elaborate on the statics and dynamics of the resulting wetting morphologies. It is demonstrated that the spectrum of wetting morphologies increases with increasing complexity of the groove structure. On elastically deformable substrates, additional structures in the liquid morphologies can be observed, which are caused by deformations of the groove geometry in the presence of capillary forces. The emergence of certain liquid morphologies in grooves can be actively controlled by changes in wettability and geometry. For electrically conducting solid substrates, the apparent contact angle can be varied by electrowetting. This allows, depending on groove geometry, a reversible or irreversible transport of liquid along surface grooves. In the case of irreversible liquid transport in triangular grooves, the dynamics of the emerging instability is sensitive to the apparent hydrodynamic slip at the substrate. On elastic substrates, the geometry can be varied in a straightforward manner by stretching or relaxing the sample. The imbibition velocity in deformable grooves is significantly reduced compared to solid grooves, which is a result of the microscopic deformation of the elastic groove material close to the three phase contact line.

  7. Tuning in to pavement radio

    NARCIS (Netherlands)

    Ellis, S.

    1989-01-01

    This article describes a phenomenon known all over Africa, for which there is no really satisfactory term in English but which is summed up in the French term 'radio trottoir', literally 'pavement radio'. It may be defined as the popular and unofficial discussion of current affairs in Africa,

  8. The Concrete and Pavement Challenge

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

    The modern world is characterized by the extensive use of concrete and asphalt pavement. Periodically, these materials are replaced and the old materials disposed of. In this challenge, students will be asked to develop ways to reuse the old materials. It is important for students to understand how concrete and asphalt are made and applied, as…

  9. Fracture mechanics in pavement design

    CSIR Research Space (South Africa)

    Denneman, E

    2009-07-01

    Full Text Available . The paper also seeks to promote the use of size independent material properties to characterize pavement materials. Some material properties used in current methods, such as the concepts of strain at break and flexural strength are known to exhibit size...

  10. The order of condensation in capillary grooves

    International Nuclear Information System (INIS)

    Rascón, Carlos; Parry, Andrew O; Nürnberg, Robert; Pozzato, Alessandro; Tormen, Massimo; Bruschi, Lorenzo; Mistura, Giampaolo

    2013-01-01

    We consider capillary condensation in a deep groove of width L. The transition occurs at a pressure p co (L) described, for large widths, by the Kelvin equation p sat − p co (L) = 2σcosθ/L, where θ is the contact angle at the side walls and σ is the surface tension. The order of the transition is determined by the contact angle of the capped end θ cap ; it is continuous if the liquid completely wets the cap, and first-order otherwise. When the transition is first-order, corner menisci at the bottom of the capillary lead to a pronounced metastability, determined by a complementary Kelvin equation Δp(L) = 2σsinθ cap /L. On approaching the wetting temperature of the capillary cap, the corner menisci merge and a single meniscus unbinds from the bottom of the groove. Finite-size scaling shifts, crossover behaviour and critical singularities are determined at mean-field level and beyond. Numerical and experimental results showing the continuous nature of condensation for θ cap = 0 and the influence of corner menisci on adsorption isotherms are presented. (fast track communication)

  11. The order of condensation in capillary grooves.

    Science.gov (United States)

    Rascón, Carlos; Parry, Andrew O; Nürnberg, Robert; Pozzato, Alessandro; Tormen, Massimo; Bruschi, Lorenzo; Mistura, Giampaolo

    2013-05-15

    We consider capillary condensation in a deep groove of width L. The transition occurs at a pressure p(co)(L) described, for large widths, by the Kelvin equation p(sat) - p(co)(L) = 2σ cosθ/L, where θ is the contact angle at the side walls and σ is the surface tension. The order of the transition is determined by the contact angle of the capped end θcap; it is continuous if the liquid completely wets the cap, and first-order otherwise. When the transition is first-order, corner menisci at the bottom of the capillary lead to a pronounced metastability, determined by a complementary Kelvin equation Δp(L) = 2σ sinθcap/L. On approaching the wetting temperature of the capillary cap, the corner menisci merge and a single meniscus unbinds from the bottom of the groove. Finite-size scaling shifts, crossover behaviour and critical singularities are determined at mean-field level and beyond. Numerical and experimental results showing the continuous nature of condensation for θcap = 0 and the influence of corner menisci on adsorption isotherms are presented.

  12. Minnesota Local Agency Pavement Marking : Mining Existing Data

    Science.gov (United States)

    2017-11-01

    Pavement marking is important for safety. Maximizing pavement marking performance in terms of increased retroreflectivity, within limited budget constraints, allows agencies to make better decisions toward providing more effective pavement marking pe...

  13. Comparison of winter temperature profiles in asphalt and concrete pavements.

    Science.gov (United States)

    2014-06-01

    The objectives of this research were to 1) determine which pavement type, asphalt or concrete, has : higher surface temperatures in winter and 2) compare the subsurface temperatures under asphalt and : concrete pavements to determine the pavement typ...

  14. Texas flexible pavements overlays : review and analysis of existing databases.

    Science.gov (United States)

    2011-12-01

    Proper calibration of pavement design and rehabilitation performance models to : conditions in Texas is essential for cost-effective flexible pavement design. The degree of : excellence with which TxDOTs pavement design models is calibrated will d...

  15. Comparison of accelerated pavement test results with long term pavement behaviour and performance

    CSIR Research Space (South Africa)

    Jooste, FJ

    1997-08-01

    Full Text Available The aim of this study was to investigate the following:how accelerated pavement testing predictions compare with actual road behaviour and performance the relative influences of load and environmental factors on pavement deterioration and how well...

  16. Calibration of full-scale accelerated pavement testing data using long-term pavement performance data

    CSIR Research Space (South Africa)

    VdM Steyn, WJ

    2012-09-01

    Full Text Available Accelerated Pavement Testing (APT) has always been conducted with the objective of improving the understanding of real pavements under real traffic and environmental conditions. While APT provides an accelerated view of some of the major structural...

  17. MoDOT pavement preservation research program volume IV, pavement evaluation tools-data collection methods.

    Science.gov (United States)

    2015-10-01

    The overarching goal of the MoDOT Pavement Preservation Research Program, Task 3: Pavement Evaluation Tools Data : Collection Methods was to identify and evaluate methods to rapidly obtain network-level and project-level information relevant to :...

  18. Verification of mechanistic-empirical design models for flexible pavements through accelerated pavement testing : technical summary.

    Science.gov (United States)

    2014-08-01

    Midwest States Accelerated Pavement Testing Pooled-Fund Program, financed by the : highway departments of Kansas, Iowa, and Missouri, has supported an accelerated : pavement testing (APT) project to validate several models incorporated in the NCHRP :...

  19. Verification of mechanistic-empirical design models for flexible pavements through accelerated pavement testing.

    Science.gov (United States)

    2014-08-01

    The Midwest States Accelerated Pavement Testing Pooled Fund Program, financed by the highway : departments of Kansas, Iowa, and Missouri, has supported an accelerated pavement testing (APT) project to : validate several models incorporated in the NCH...

  20. Feasibility of reclaimed asphalt pavement as aggregate in portland cement concrete pavement, phase II : field demonstration.

    Science.gov (United States)

    2015-10-01

    This research was focused on evaluating the feasibility of using minimally processed reclaimed asphalt pavement (RAP) as : aggregate replacement in concrete pavements. An initial phase of research demonstrated that concretes with up to 50 percent : o...

  1. Feasibility of reclaimed asphalt pavement as aggregate in portland cement concrete pavements.

    Science.gov (United States)

    2013-11-01

    This research effort was focused on evaluating the feasibility of using minimally processed reclaimed : asphalt pavement (RAP) as aggregate replacement in concrete pavements. This research demonstrated : that concretes with up to 50 percent of the fi...

  2. Advanced Pavement Design: Finite Element Modeling for Rigid Pavement Joints, Report II: Model Development

    National Research Council Canada - National Science Library

    Hammons, Michael

    1998-01-01

    .... The objective of this research was to obtain data on the response of the ng'id pavement slab-joint-foundation system by conducting laboratory-scale experiments on jointed rigid pavement models...

  3. An integrated pavement data management and feedback system (PAMS) : evaluation of pavement condition rating procedure.

    Science.gov (United States)

    1984-08-01

    This report describes an evaluation of a method for use in the Highway Needs Study pavement condition rating. The methods by which the Department generates and manages pavement condition data in the overall process of providing a network of highways ...

  4. Existing pavement input information for the mechanistic-empirical pavement design guide.

    Science.gov (United States)

    2009-02-01

    The objective of this study is to systematically evaluate the Iowa Department of Transportations (DOTs) existing Pavement Management Information System (PMIS) with respect to the input information required for Mechanistic-Empirical Pavement Des...

  5. Integration and Evaluation of Automated Pavement Distress Data in INDOT’s Pavement Management System

    Science.gov (United States)

    2017-05-01

    This study was in two parts. The first part established and demonstrated a framework for pavement data integration. This is critical for fulfilling QC/QA needs of INDOTs pavement management system, because the precision of the physical location re...

  6. Numerical analysis of flow in a centrifugal compressor with circumferential grooves: influence of groove location and number on flow instability

    Science.gov (United States)

    Chen, X.; Qin, G.; Ai, Z.; Ji, Y.

    2017-08-01

    As an effective and economic method for flow range enhancement, circumferential groove casing treatment (CGCT) is widely used to increase the stall margin of compressors. Different from traditional grooved casing treatments, in which the grooves are always located over the rotor in both axial and radial compressors, one or several circumferential grooves are located along the shroud side of the diffuser passage in this paper. Numerical investigations were conducted to predict the performance of a low flow rate centrifugal compressor with CGCT in diffuser. Computational fluid dynamics (CFD) analysis is performed under stage environment in order to find the optimum location of the circumferential casing groove in consideration of stall margin enhancement and efficiency gain at design point, and the impact of groove number to the effect of this grooved casing treatment configuration in enhancing the stall margin of the compressor stage is studied. The results indicate that the centrifugal compressor with circumferential groove in vaned diffuser can obtain obvious improvement in the stall margin with sacrificing design efficiency a little. Efforts were made to study blade level flow mechanisms to determine how the CGCT impacts the compressor’s stall margin (SM) and performance. The flow structures in the passage, the tip gap, and the grooves as well as their mutual interactions were plotted and analysed.

  7. Factors Affecting Pavement Surface and Evaluation Rating Accuracy and Variability

    OpenAIRE

    Montgomery, Sharlan R; Haddock, John E

    2018-01-01

    The collection of sufficient, accurate, and consistent pavement condition data is essential to an effective pavement management system. Condition data drive a variety of pavement management tasks such as: • Predicting future pavement performance• Identifying current and future maintenance and rehabilitation needs • Estimating budget needs and requirements • Reporting to decision makers • Selecting appropriate pavement management tools Pavement condition data are represented at either th...

  8. Enhancing pavement performance prediction models for the Illinois Tollway System

    OpenAIRE

    Laxmikanth Premkumar; William R. Vavrik

    2016-01-01

    Accurate pavement performance prediction represents an important role in prioritizing future maintenance and rehabilitation needs, and predicting future pavement condition in a pavement management system. The Illinois State Toll Highway Authority (Tollway) with over 2000 lane miles of pavement utilizes the condition rating survey (CRS) methodology to rate pavement performance. Pavement performance models developed in the past for the Illinois Department of Transportation (IDOT) are used by th...

  9. MoDOT pavement preservation research program volume III, development of pavement family and treatment performance models.

    Science.gov (United States)

    2015-10-01

    Pavement performance models describe the deterioration behavior of pavements. They are essential in a pavement management : system if the goal is to make more objective, reliable, and cost-effective decisions regarding the timing and nature of paveme...

  10. Using Tire/Pavement Interface Noise Results to Define Statistically Similar Bituminous Pavements in Massachusetts

    OpenAIRE

    Hencken, John; Haas, Edwin; Bennert, Thomas

    2012-01-01

    In October 2010, the Center for Advanced Infrastructure and Transportation (CAIT) utilized the On-Board Sound Intensity Method in Massachusetts to evaluate seven Open-Graded Friction Courses (OGFC) and eight Asphalt Rubber Gap Graded (ARGG) pavements for MassDOT. Since major concerns regarding pavement selection in the northeast revolve around winter conditions and winter maintenance, if noise level similarities could be found between ARGG and OGFC pavements, pavement engineers would be able ...

  11. Pavement Preservation for Elected Officials: The Inside Story of Pavement Deterioration

    OpenAIRE

    Olson, Jim

    2012-01-01

    This session is intended to provide elected officials and practitioners with an introduction to the concept of pavement preservation and its applicability within public agencies. Topics include definitions, budget planning, pavement life, road networks, alternative strategies, pavement distresses, guidelines and preservation treatments.

  12. Inverted base pavements: construction and performance

    KAUST Repository

    Papadopoulos, Efthymios

    2017-05-11

    Inverted base pavements involve a well-compacted granular aggregate base built between a thin asphalt concrete layer and a cement-treated base. Inverted base pavements can be constructed using conventional equipment and procedures but require proper quality control. This study reviews the extensive South African experience and case histories in the USA. Accumulating evidence suggests that inverted base pavements are a viable alternative and can outperform conventional pavements at a lower cost. Inverted base pavements rely on the complementary interaction between layers. The cement-treated base provides a stiff foundation for efficient compaction and constrains the deformation of the stress-sensitive granular aggregate base. The thin asphalt surface layer deforms as a membrane and develops low tensile stress. Additional large-scale field tests should be conducted to assess the performance of inverted base pavement designs in a wide range of conditions relevant to the USA.

  13. From the Bandstand to the Classroom: Thinking and Playing Grooves

    Science.gov (United States)

    Baxter, Marsha; Santantasio, Christopher

    2012-01-01

    In this article, narratives of a salsa concert and a lesson with a Native American flute performer provide openings for exploring grooves and their application in the music classroom. The term "groove" is examined, along with some non-Western ideas about time as represented in the music of the West African Kpelle people. A sixth-grade…

  14. Heat transfer and thermal stress analysis in grooved tubes

    Indian Academy of Sciences (India)

    Heat transfer and thermal stresses, induced by temperature differencesin the internally grooved tubes of heat transfer equipment, have been analysed numerically. The analysis has been conducted for four different kinds of internally grooved tubes and three different mean inlet water velocities. Constant temperature was ...

  15. Grooves on the occipital lobe of Indian brains.

    Science.gov (United States)

    Bisaria, K K

    1984-01-01

    The existence of a groove on the occipital lobe formed by the dural venous sinus or ridge has only rarely been described in the past. As observed in this study such grooves are either unilateral or bilateral and their incidence is very high in Indian brains. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:6490537

  16. Grooves on the occipital lobe of Indian brains.

    OpenAIRE

    Bisaria, K K

    1984-01-01

    The existence of a groove on the occipital lobe formed by the dural venous sinus or ridge has only rarely been described in the past. As observed in this study such grooves are either unilateral or bilateral and their incidence is very high in Indian brains.

  17. Observations of secondary oscillations in thermal grain boundary grooves

    International Nuclear Information System (INIS)

    Sachenko, P.P.; Schneibel, J.H.; Zhang, W.

    2004-01-01

    Thermal grain boundary grooving by surface diffusion is accompanied not only by main maxima on either side of a groove, but also by secondary maxima and minima. We measure these oscillations in tungsten and give reasons why the observed secondary maxima and minima are larger than predicted

  18. Olfactory groove meningiomas: approaches and complications.

    Science.gov (United States)

    Aguiar, Paulo Henrique Pires de; Tahara, Adriana; Almeida, Antonio Nogueira; Simm, Renata; Silva, Arnaldo Neves da; Maldaun, Marcos Vinicius Calfatt; Panagopoulos, Alexandros Theodoros; Zicarelli, Carlos Alexandre; Silva, Pedro Gabriel

    2009-09-01

    Olfactory groove meningiomas (OGM) account for 4.5% of all intracranial meningiomas. We report 21 patients with OGMs. Tumors were operated on using three surgical approaches: bifrontal (7 patients), fronto-pterional (11 patients) and fronto-orbital (3 patients). Total tumor removal (Simpson Grade 1) was achieved in 13 patients and Simpson II in 8 patients. Perioperative mortality was 4.76%. The average size of the OGM was 4.3+/-1.1cm. The overall recurrence rate was 19%. We preferred to use the pterional approach, which provides quick access to the tumor with less brain exposure. It also allows complete drainage of cisternal cerebrospinal fluid, providing a good level of brain relaxation during surgery. However, for long, thin tumors, hemostasis can be difficult using this approach.

  19. Plasma interaction with emmissive surface with Debye-scale grooves

    Science.gov (United States)

    Schweigert, Irina; Burton, Thomas S.; Thompson, Gregory B.; Langendorf, Samuel; Walker, Mitchell L. R.; Keidar, Michael

    2018-04-01

    The sheath development over emissive grooved surface in dc discharge plasma controlled by an electron beam is studied in the experiment and in 2D kinetic simulations. Grooved hexagonal boron nitride surfaces with different aspect ratios, designed to mimic the erosion channels, were exposed to an argon plasma. The characteristic size of the grooves (1 mm and 5 mm) is about of the Debye length. The secondary electrons emission from the grooved surfaces is provided by the bombardment with energetic electrons originated from the heated powered cathode. The transition between a developed and a collapsed sheaths near emissive surface takes place with an increase of the beam electron energy. For grooved emissive surfaces, the sheath transition happens at essentially higher voltage compared to the planar one. This phenomenon is analyzed in the terms of the electron energy distribution function.

  20. Characteristics of Multiplexed Grooved Nozzles for High Flow Rate Electrospray

    International Nuclear Information System (INIS)

    Kim, Kyoung Tae; Kim, Woo Jin; Kim, Sang Soo

    2007-01-01

    The electrospray operated in the cone-jet mode can generate highly charged micro droplets in an almost uniform size at flow rates. Therefore, the multiplexing system which can retain the characteristics of the cone-jet mode is inevitable for the electrospray application. This experiment reports the multiplexed grooved nozzle system with the extractor. The effects of the grooves and the extractor on the performance of the electrospray were evaluated through experiments. Using the grooved nozzle, the stable cone-jet mode can be achieved at the each groove in the grooved mode. Furthermore, the number of nozzles per unit area is increased by the extractor. The multiplexing density is 12 jets per cm 2 at 30 mm distance from the nozzle tip to the ground plate. The multiplexing system for the high flow rate electrospray is realized with the extractor which can diminish the space charge effect without sacrificing characteristics of the cone-jet mode

  1. Long Life Pavements; Firmes de larga duracion

    Energy Technology Data Exchange (ETDEWEB)

    Mateos Moreno, A.; Marron Fernandez, J. O.; Perez Ayuso, J.

    2009-07-01

    The existence of long-life pavements is not new; they have been built in Europe and the United States for decades. In fact, the concept arises from the observation of in-service roads; it was verified how particular pavements, initially designed for a 20-year service life, did not seem to have reduced the bearing capacity along the time, and its maintenance necessities had been exclusively focused on the wearing course. The base idea of long-life pavements is the existence of a fatigue threshold below which the damage produced by each load application is, in practice, zero or below the healing potential of the asphalt mix. The use practice of long-life pavements design considers a pavements constituted by three asphalt layers, each one with a very specific role: a wearing course that provides with the surface characteristics, an intermediate course that provides with most of the structural capacity and a base course that provides with the fatigue resistance. Furthermore, one of the particularities is the design against specific distress mechanisms. Maintenance strategy also presents specific particularities for long-life pavements. It is essentially focused on the detection of surface deterioration, and the appropriate and timely repair, before the damage extends beyond the wearing course, putting into risk the structural integrity of the pavement. Nowadays, this new way to conceive the design, the construction and the maintenance of road pavements, constitutes one of the main challenges for pavement engineering worldwide. (Author) 5 refs.

  2. Evaluating life cycle costs of perpetual pavements in China using operational pavement management system

    Directory of Open Access Journals (Sweden)

    Saud A. Sultan

    2016-10-01

    Full Text Available Highway transportation is considered as vital factor in China’s economic growth; many high grade highways have been constructed in China during the last decades. The research and application of perpetual asphalt pavement (PP technology have been deployed in China since 2000. The semi-rigid pavement has been normally considered as typical pavement of high class highways in the design according to the Chinese experience. The objective of this research is to evaluate the performance of different Chinese perpetual pavements using operational pavement management system and to examine its suitability for use in the design and construction of more economical and durable pavements. It has been found that the use of thin asphalt layers over semi-rigid pavement foundation in PP structure will create more sustainable, economical, and durable PP structures in comparison with typical thick asphalt layers PP structures.

  3. Double-grooved nanofibre surfaces with enhanced anisotropic hydrophobicity.

    Science.gov (United States)

    Liang, Meimei; Chen, Xin; Xu, Yang; Zhu, Lei; Jin, Xiangyu; Huang, Chen

    2017-11-02

    This study reports a facile method for fabricating double-grooved fibrous surfaces. The primary grooves of the surface are formed by aligned fibres, while the secondary grooves are achieved by oriented nanogrooves on the fibre surface. Investigation into the formation mechanism reveals that the nanogrooves can be readily tailored through adjusting the solvent ratio and relative humidity. With this understanding, a variety of polymers have been successfully electrospun into fibres having the same nanogrooved feature. These fibres show high resemblance to natural hierarchical structures, and thereby endowing the corresponding double-grooved surface with enhanced anisotropic hydrophobicity. A water droplet at a parallel direction to the grooves exhibits a much higher contact angle and a lower roll-off angle than the droplet at a perpendicular direction. The application potential of such anisotropic hydrophobicity has been demonstrated via a fog collection experiment, in which the double-grooved surface can harvest the largest amount of water. Moreover, the fabrication method requires neither post-treatment nor sophisticated equipment, making us anticipate that the double-grooved surface would be competitive in areas where a highly ordered surface, a large surface area and an anisotropic hydrophobicity are preferred.

  4. Modelling Flexible Pavement Response and Performance

    DEFF Research Database (Denmark)

    Ullidtz, Per

    This textbook is primarily concerned with models for predicting the future condition of flexible pavements, as a function of traffic loading, climate, materials, etc., using analytical-empirical methods.......This textbook is primarily concerned with models for predicting the future condition of flexible pavements, as a function of traffic loading, climate, materials, etc., using analytical-empirical methods....

  5. Numerical Simulation of Tire-Pavement Interaction

    NARCIS (Netherlands)

    Srirangam, S.K.

    2015-01-01

    Good skid resistance of a pavement surface is essential for road safety. Loss of skid resistance can lead to property damage and loss of lives. Ever increasing need of driver safety poses challenges to the highway authorities to evaluate pavement conditions even more precisely under different

  6. Load Response Analysis of Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    Xiao Zhijun

    2016-01-01

    Full Text Available Based on the filed data of Fuzhou test road, load response regulation of nonlinear pavement structure was analyzed in this paper; Mechanics software was adopted to analyze linear elastic and nonlinear of the pavement structure, analyzed results and road filed data were compared, and determine the correlation between them and the field data.

  7. Analysis and design optimization of flexible pavement

    Energy Technology Data Exchange (ETDEWEB)

    Mamlouk, M.S.; Zaniewski, J.P.; He, W.

    2000-04-01

    A project-level optimization approach was developed to minimize total pavement cost within an analysis period. Using this approach, the designer is able to select the optimum initial pavement thickness, overlay thickness, and overlay timing. The model in this approach is capable of predicting both pavement performance and condition in terms of roughness, fatigue cracking, and rutting. The developed model combines the American Association of State Highway and Transportation Officials (AASHTO) design procedure and the mechanistic multilayer elastic solution. The Optimization for Pavement Analysis (OPA) computer program was developed using the prescribed approach. The OPA program incorporates the AASHTO equations, the multilayer elastic system ELSYM5 model, and the nonlinear dynamic programming optimization technique. The program is PC-based and can run in either a Windows 3.1 or a Windows 95 environment. Using the OPA program, a typical pavement section was analyzed under different traffic volumes and material properties. The optimum design strategy that produces the minimum total pavement cost in each case was determined. The initial construction cost, overlay cost, highway user cost, and total pavement cost were also calculated. The methodology developed during this research should lead to more cost-effective pavements for agencies adopting the recommended analysis methods.

  8. Pervious Pavement System Evaluation-Paper

    Science.gov (United States)

    The use of a pervious pavement can be effective as a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete paver systems as a type of porous pavement. Although the pavers are impermeable, the spaces between the pave...

  9. Vacuum sealing with a spiral grooved gas dynamic seal

    International Nuclear Information System (INIS)

    Sawada, Tadashi

    1979-01-01

    Gas dynamic seals with rectangular spiral grooves are studied theoretically taking the effects of sidewalls of the grooves and the effects of gas compressibility into account, and slip boundary conditions are employed. The results are compared with the existing experimental data and the validity of the theory is confirmed over a wide pressure range except for the extremely low pressures. Suggestions are made regarding the choice of the geometrical dimensions, i.e., aspect ratio, helix angle, clearance parameter and groove width ratio. (author)

  10. Grooved Fuel Rings for Nuclear Thermal Rocket Engines

    Science.gov (United States)

    Emrich, William

    2009-01-01

    An alternative design concept for nuclear thermal rocket engines for interplanetary spacecraft calls for the use of grooved-ring fuel elements. Beyond spacecraft rocket engines, this concept also has potential for the design of terrestrial and spacecraft nuclear electric-power plants. The grooved ring fuel design attempts to retain the best features of the particle bed fuel element while eliminating most of its design deficiencies. In the grooved ring design, the hydrogen propellant enters the fuel element in a manner similar to that of the Particle Bed Reactor (PBR) fuel element.

  11. Improving rutting resistance of pavement structures using geosynthetics: an overview.

    Science.gov (United States)

    Mirzapour Mounes, Sina; Karim, Mohamed Rehan; Khodaii, Ali; Almasi, Mohammad Hadi

    2014-01-01

    A pavement structure consists of several layers for the primary purpose of transmitting and distributing traffic loads to the subgrade. Rutting is one form of pavement distresses that may influence the performance of road pavements. Geosynthetics is one type of synthetic materials utilized for improving the performance of pavements against rutting. Various studies have been conducted on using different geosynthetic materials in pavement structures by different researchers. One of the practices is a reinforcing material in asphalt pavements. This paper intends to present and discuss the discoveries from some of the studies on utilizing geosynthetics in flexible pavements as reinforcement against permanent deformation (rutting).

  12. Improving Rutting Resistance of Pavement Structures Using Geosynthetics: An Overview

    Directory of Open Access Journals (Sweden)

    Sina Mirzapour Mounes

    2014-01-01

    Full Text Available A pavement structure consists of several layers for the primary purpose of transmitting and distributing traffic loads to the subgrade. Rutting is one form of pavement distresses that may influence the performance of road pavements. Geosynthetics is one type of synthetic materials utilized for improving the performance of pavements against rutting. Various studies have been conducted on using different geosynthetic materials in pavement structures by different researchers. One of the practices is a reinforcing material in asphalt pavements. This paper intends to present and discuss the discoveries from some of the studies on utilizing geosynthetics in flexible pavements as reinforcement against permanent deformation (rutting.

  13. Fatigue and rutting lives in flexible pavement

    Directory of Open Access Journals (Sweden)

    Ahmed Ebrahim Abu El-Maaty Behiry

    2012-12-01

    Full Text Available Flexible pavement is designed based on axle load limits and climatic conditions. The Egyptian code has specified certain load limits that should not be exceeded. The overweight trucks cause severe deterioration to the pavement and thus reduce its life. The study aims at studying the effect of axle load increase, and the variation in pavement modulus, on the overall pavement life. The research uses the BISAR software and the Egyptian environmental and pavement materials conditions to estimate the tensile strains occurring under the asphalt concrete (AC layer and the compressive strains above the subgrade surface. The results revealed that tensile and compressive strain increased with increasing axle loads and decreased with increasing asphalt layer modulus thus the violating trucks should be unloaded when their weights exceed certain limits. Base thickness and subgrade resilient modulus were the key elements which control the equilibrium between fatigue and rutting lives.

  14. Surface Distresses Detection of Pavement Based on Digital Image Processing

    OpenAIRE

    Ouyang , Aiguo; Luo , Chagen; Zhou , Chao

    2010-01-01

    International audience; Pavement crack is the main form of early diseases of pavement. The use of digital photography to record pavement images and subsequent crack detection and classification has undergone continuous improvements over the past decade. Digital image processing has been applied to detect the pavement crack for its advantages of large amount of information and automatic detection. The applications of digital image processing in pavement crack detection, distresses classificati...

  15. Surgical Management of Olfactory Groove Meningiomas | El-Naggar ...

    African Journals Online (AJOL)

    Objective: To study the bifrontal approach to olfactory groove meningiomas ... in all patients was Grade I meningiomas (World Health Organization grading). ... Bifrontal approach offers excellent exposure, and when combined with modern ...

  16. Interproximal grooving in the Atapuerca-SH hominid dentitions.

    Science.gov (United States)

    Bermúdez de Castro, J M; Arsuaga, J L; Pérez, P J

    1997-03-01

    The dental sample recovered from the Sima de los Huesos (SH) Middle Pleistocene cave site of the Sierra de Atapuerca (Spain) includes 296 specimens. Interproximal wear grooves have been observed in 20 maxillary and mandibular posterior teeth belonging to at least five of the 32 individuals identified so far in the SH hypodigm. Interproximal grooving affected only the adults, and at an age between 25 and 40 years. The appearance, morphology, and location pattern of the SH wear grooves are similar to those reported in other fossil hominids and in more recent human populations. Two alternative proposals, the toothpicking and the fiber or sinew processing hypotheses, compete for explaining the formation of this anomalous wear. The characteristics observed in the wear grooves of the SH teeth are compatible only with the habitual probing of interdental spaces by means of hard and inflexible objects. Dietary grit may also have contributed to the abrasion of the root walls during the motion of the dental probes.

  17. Fractures of the proximal humerus involving the intertubercular groove

    International Nuclear Information System (INIS)

    Ahovuo, J.; Paavolainen, P.; Bjoerkenheim, J.M.; Helsinki Univ. Central Hospital

    1989-01-01

    The purpose of this study was to analyse the involvement of the gliding surface of the biceps tendon in fractures of the proximal humerus. Fifteen patients had a fracture of the proximal humerus verified with antero-posterior and axillary radiographs. Tangential radiographs of the intertubercular groove, obtained from the shoulder joint, showed involvement of the intertubercular groove in 13 patients (87%), which could not be shown with other projections. Groove radiographs revealed in 3 patients a dislocation of the fragments of the greater tuberosity large enough to require surgical treatment, but which had not been found using conventional techniques. Therefore, a groove radiograph should be used to precise fractures of the proximal humerus. (orig.)

  18. V-groove plasmonic waveguides fabricated by nanoimprint lithography

    DEFF Research Database (Denmark)

    Fernandez-Cuesta, I.; Nielsen, R.B.; Boltasseva, Alexandra

    2007-01-01

    Propagation of channel plasmon-polariton modes in the bottom of a metal V groove has been recently demonstrated. It provides a unique way of manipulating light at nanometer length scale. In this work, we present a method based on nanoimprint lithography that allows parallel fabrication of integra...... of integrated optical devices composed of metal V grooves. This method represents an improvement with respect to previous works, where the V grooves were fabricated by direct milling of the metal, in terms of robustness and throughput. © 2007 American Vacuum Society......Propagation of channel plasmon-polariton modes in the bottom of a metal V groove has been recently demonstrated. It provides a unique way of manipulating light at nanometer length scale. In this work, we present a method based on nanoimprint lithography that allows parallel fabrication...

  19. [Developmental radicular groove as a cause of endodontic failure].

    Science.gov (United States)

    Fabra Campos, H; Millet Part, J

    1989-01-01

    A clinical case of apical injury on an upper lateral incisor with endodontical and surgical failures in its treatment is presented. Extraction of the incisor and its study at the stereoscopic microscope showed the existence of a developmental groove running from the cingulum to the end of the root, establishing a communication between the crevice and the apical part of the tooth. Bacterial infection through the groove could provide an explanation for treatment failure.

  20. Enhancing pavement performance prediction models for the Illinois Tollway System

    Directory of Open Access Journals (Sweden)

    Laxmikanth Premkumar

    2016-01-01

    Full Text Available Accurate pavement performance prediction represents an important role in prioritizing future maintenance and rehabilitation needs, and predicting future pavement condition in a pavement management system. The Illinois State Toll Highway Authority (Tollway with over 2000 lane miles of pavement utilizes the condition rating survey (CRS methodology to rate pavement performance. Pavement performance models developed in the past for the Illinois Department of Transportation (IDOT are used by the Tollway to predict the future condition of its network. The model projects future CRS ratings based on pavement type, thickness, traffic, pavement age and current CRS rating. However, with time and inclusion of newer pavement types there was a need to calibrate the existing pavement performance models, as well as, develop models for newer pavement types.This study presents the results of calibrating the existing models, and developing new models for the various pavement types in the Illinois Tollway network. The predicted future condition of the pavements is used in estimating its remaining service life to failure, which is of immediate use in recommending future maintenance and rehabilitation requirements for the network. Keywords: Pavement performance models, Remaining life, Pavement management

  1. Experimental and Numerical Investigation on Tribological Performance of Grooved Texture

    Directory of Open Access Journals (Sweden)

    CHEN Ping

    2016-06-01

    Full Text Available In order to study the influence of the angle and arrangement forms of micro-grooves on the tribological performance of the contact surface, the finite element analysis software was used to simulate the grooved textures with different angles and arrangements. The YLP-20 laser processing system was used to process grooved texture on stainless steel disk surfaces, and the Tribometer (UMT-2 was also used to conduct tribological test under the condition of rotation. The results show that the numerical simulation values are basically consistent with experimental results of grooved textures, and the tribological performance of the friction pairs with textures is also improved. The grooved textures with different angles and arrangement forms have different influence on tribological performance of friction pairs. When the friction velocity is less than 300r/min, the parallel texture with 0° has smaller friction coefficients. While the friction velocity is larger than 300r/min, the parallel texture with 90° has a better ability of reducing friction. Therefore, different grooved textures should be chosen according to operation conditions.

  2. Assessment of highway pavements using GPR

    Science.gov (United States)

    Plati, Christina; Loizos, Andreas

    2015-04-01

    Highway infrastructure is a prerequisite for a functioning economy and social life. Highways, often prone to congestion and disruption, are one of the aspects of a modern transport network that require maximum efficiency if an integrated transport network, and sustainable mobility, is to be achieved. Assessing the condition of highway structures, to plan subsequent maintenance, is essential to allow the long-term functioning of a road network. Optimizing the methods used for such assessment will lead to better information being obtained about the road and underlying ground conditions. The condition of highway structures will be affected by a number of factors, including the properties of the highway pavement, the supporting sub-base and the subgrade (natural ground), and the ability to obtain good information about the entire road structure, from pavement to subgrade, allows appropriate maintenance programs to be planned. The maintenance of highway pavements causes considerable cost and in many cases obstruction to traffic flow. In this situation, methods that provide information on the present condition of pavement structure non-destructively and economically are of great interest. It has been shown that Ground-Penetrating-Radar (GPR), which is a Non Destructive Technique (NDT), can deliver information that is useful for the planning of pavement maintenance activities. More specifically GPR is used by pavement engineers in order to determine physical properties and characteristics of the pavement structure, information that is valuable for the assessment of pavement condition. This work gives an overview on the practical application of GPR using examples from highway asphalt pavements monitoring. The presented individual applications of GPR pavement diagnostics concern structure homogeneity, thickness of pavement layers, dielectric properties of asphalt materials etc. It is worthwhile mentioning that a number of applications are standard procedures, either

  3. Global warming potential of pavements

    Energy Technology Data Exchange (ETDEWEB)

    Santero, Nicholas J [Department of Civil and Environmental Engineering, 407 McLaughlin Hall, University of California, Berkeley, CA 94720-1712 (United States); Horvath, Arpad, E-mail: njsantero@cal.berkeley.ed, E-mail: horvath@ce.berkeley.ed [Department of Civil and Environmental Engineering, 215B McLaughlin Hall, University of California, Berkeley, CA 94720-1712 (United States)

    2009-09-15

    Pavements comprise an essential and vast infrastructure system supporting our transportation network, yet their impact on the environment is largely unquantified. Previous life-cycle assessments have only included a limited number of the applicable life-cycle components in their analysis. This research expands the current view to include eight different components: materials extraction and production, transportation, onsite equipment, traffic delay, carbonation, lighting, albedo, and rolling resistance. Using global warming potential as the environmental indicator, ranges of potential impact for each component are calculated and compared based on the information uncovered in the existing research. The relative impacts between components are found to be orders of magnitude different in some cases. Context-related factors, such as traffic level and location, are also important elements affecting the impacts of a given component. A strategic method for lowering the global warming potential of a pavement is developed based on the concept that environmental performance is improved most effectively by focusing on components with high impact potentials. This system takes advantage of the fact that small changes in high-impact components will have more effect than large changes in low-impact components.

  4. Global warming potential of pavements

    International Nuclear Information System (INIS)

    Santero, Nicholas J; Horvath, Arpad

    2009-01-01

    Pavements comprise an essential and vast infrastructure system supporting our transportation network, yet their impact on the environment is largely unquantified. Previous life-cycle assessments have only included a limited number of the applicable life-cycle components in their analysis. This research expands the current view to include eight different components: materials extraction and production, transportation, onsite equipment, traffic delay, carbonation, lighting, albedo, and rolling resistance. Using global warming potential as the environmental indicator, ranges of potential impact for each component are calculated and compared based on the information uncovered in the existing research. The relative impacts between components are found to be orders of magnitude different in some cases. Context-related factors, such as traffic level and location, are also important elements affecting the impacts of a given component. A strategic method for lowering the global warming potential of a pavement is developed based on the concept that environmental performance is improved most effectively by focusing on components with high impact potentials. This system takes advantage of the fact that small changes in high-impact components will have more effect than large changes in low-impact components.

  5. Ion implantation planar in targets with semi-cylindrical grooves

    International Nuclear Information System (INIS)

    Filiz, Y.; Demokan, O.

    2002-01-01

    The experimental and numerical investigations suggest that the ion-matrix phase of the sheath evolution plays a crucial role in determining the ion flux to the target surfaces . It can easily be realized that conformal mapping of the target's surface by the sheath is questionable, or even inapplicable in the case of surfaces with fine irregularities or this continuities. The theoretical analysis of such cases is evidently quite complicated. On the other hand, most actual targets fall into this category, and hence, the understanding of the corresponding sheath behavior remains vital for accomplishing uniform implantation. The ion- matrix sheaths have been treated analytically by Conrad for planar, cylindrical and spherical targets successfully. Similar y, Sheridan and Zang et al. have investigated the ion matrix sheath in cylindrical bores, without and with axial electrodes, respectively. All these works assumed targets with infinite areas or length, Zeng et al. and Kwok et al. have started studying implantation into grooves, by carrying out simulations for the inner and outer races of bearings, which are modeled as semi- cylinders of infinite length. Finally, Demokan has presented the first analytic treatment of on matrix sheaths in two- dimensions, by considering targets with rectangular grooves of infinite length, representing a broad range of industrial items. In this work, ion-matrix sheath near infinite length are theoretically analysed. Understanding the sheath formation near such targets is essential for achieving successful ion implantation on the surfaces of a broad range of industrial products, including all types of bearings. The potential profiles both inside and outside the groove are derived and the consequent ion velocity higher plasma densities may improve the uniformity of implantation on the surfaces of such grooves. Furthermore, the sheath edge deformation due to the grooves, the variation of the angle of incidence on the surface of the groove

  6. Formation Mechanisms for Spur and Groove Features on Fringing Reefs

    Science.gov (United States)

    Bramante, J. F.; Ashton, A. D.; Perron, J. T.

    2016-12-01

    Spur and groove systems (SAGs) are ubiquitous morphological features found on fore-reef slopes globally. SAGs consist of parallel, roughly shore-normal ridges of actively growing coral and coralline algae (spurs) separated by offshore-sloping depressions typically carpeted by a veneer of sediment (grooves). Although anecdotal observations and recent statistical analyses have reported correlations between wave exposure and the distribution of SAGs on fore-reef slopes, the physical mechanisms driving SAG formation remain poorly understood. For example, there remains significant debate regarding the importance of coral growth versus bed erosion for SAG formation. Here we investigate a hypothesis that SAG formation is controlled by feedbacks between sediment production and diffusion and coral growth. Using linear stability analysis, we find that sediment production, coral growth, and the feedbacks between them are unable to produce stable periodic structures without a sediment sink. However, if incipient grooves act as conduits for sediment transport offshore, a positive feedback can develop as the groove bed erodes through wave-driven abrasion during offshore transport. Eventually a negative feedback slows groove deepening when the groove bed is armored by sediment, and the groove bed relaxes to a sediment-veneered equilibrium profile analogous to sediment-rich shorefaces. To test this hypothesis, we apply a numerical model that incorporates coral growth and sediment production, sediment diffusion, non-linear wave-driven abrasion, and sediment advection offshore. This model produces the periodic, linear features characteristic of SAG morphology. The relative magnitude of growth, production, diffusion, abrasion, and advection rates affect periodic spacing or wavelength of the modeled SAGs. Finally, we evaluate the ability of the model to replicate geographical variability in SAG characteristics using previously published datasets and reanalysis wave data.

  7. Permeable Pavement Research - Edison, New Jersey

    Science.gov (United States)

    This presentation provides the background and summary of results collected at the permeable pavement parking lot monitored at the EPA facility in Edison, NJ. This parking lot is surfaced with permeable interlocking concrete pavers (PICP), pervious concrete, and porous asphalt. ...

  8. PAVEMENT AS CONTINUITY - THE CASE FROM LISBON

    Directory of Open Access Journals (Sweden)

    Joana Pimenta

    2009-04-01

    To conclude this practical part of the study a small proposal is presented defining guide lines for an intervention regarding the pavement of the study case, in which its different characteristics are and potential analysed.

  9. Characterization and Modeling of Recycled Pavement Sections

    Science.gov (United States)

    2017-12-01

    Because of its documented cost and environmental benefits, cold central plant recycling (CCPR) has attracted the interest of local and state departments of transportation. In 2015 two test pavement sections with CCPR as base layers were constructed a...

  10. User's guide : pavement marking management system database.

    Science.gov (United States)

    2011-12-01

    Pavement markings play a critical role in maintaining a safe and efficient driving environment for road users, especially during nighttime conditions. The Texas Department of Transportation (TxDOT) spends millions of dollars each year for installatio...

  11. Noise measurements of highway pavements in Texas.

    Science.gov (United States)

    2009-10-01

    This report presents the results of noise testing performed on Texas pavements between May of 2006 and the : summer of 2008. Two field test methodologies were used: roadside noise measurement with SPL meters and onvehicle : sound intensity measuremen...

  12. Performance of I-57 recycled concrete pavements.

    Science.gov (United States)

    2009-01-01

    In 1986-1987 the Illinois Department of Transportation (IDOT) constructed a demonstration project on I-57 near Effingham, Illinois to evaluate the viability : of recycling an existing jointed reinforced concrete pavement for use as its primary aggreg...

  13. Optimization of safety on pavement preservation projects.

    Science.gov (United States)

    2011-01-01

    To achieve a goal of reducing highway crash fatalities by 4% each year to improve roadway safety, the Georgia Department of Transportation (GDOT) is actively seeking opportunities to incorporate safety improvements into its current pavement preservat...

  14. MoDOT pavement preservation research program.

    Science.gov (United States)

    2014-08-01

    The following report documents a research project on pavement preservation performed by the Missouri University of Science and : Technology (Missouri S&T) and the University of Missouri-Columbia (UMC) on behalf of the Missouri Department of Transport...

  15. Life cycle assessment of asphalt pavement maintenance.

    Science.gov (United States)

    2014-01-01

    This study aims at developing a life cycle assessment (LCA) model to quantify the impact of pavement preservation on energy consumption and greenhouse gas (GHG) emissions. The construction stage contains material, manufacture, transportation and plac...

  16. Pervious Pavement System Evaluation- Abstract 1

    Science.gov (United States)

    Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, gra...

  17. On-road Bicycle Pavement Markings

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — A mile by mile breakdown of the on-street bicycle pavement markings installed within the City of Pittsburgh. These include bike lanes, shared lane markings...

  18. Alternative pavement designs : Randolph park and ride.

    Science.gov (United States)

    2013-05-01

    Previous research on alternative pavement type bidding has proven that various treatments : are unique in terms of constructability, material characteristics, and associated performance. : While some treatments may have higher initial costs, it is im...

  19. Evaluation of concrete pavement patching techniques.

    Science.gov (United States)

    1989-01-01

    This final report presents the results of a study undertaken to improve in concrete pavement patching techniques. Activities included an evaluation of the suitability of the impact hammer and maturity calculations for determining when a patch is read...

  20. Performance evaluation of precast prestressed concrete pavement.

    Science.gov (United States)

    2007-11-01

    This report describes in detail an experimental investigation of an innovative precast prestressed concrete pavement (PPCP) system used to rehabilitate a 1,000 ft. section of interstate highway located on the northbound lanes of I-57 near Charleston,...

  1. Class C fly ash in pavements.

    Science.gov (United States)

    2010-07-01

    Portland cement is the most dominant material used in concrete pavements in the state of Nebraska. In order to improve performance, reduce cost, and advance sustainability, a percentage of the Portland cement is replaced with a recycled material know...

  2. Continuous blood fractionation using an array of slanted grooves

    Science.gov (United States)

    Bernate, Jorge A.; Chengxun, Liu; Lagae, Liesbet; Drazer, German

    2011-11-01

    Blood is a complex fluid having different specialized biological functions and containing a plethora of clinical information. The separation of different blood components is a crucial step in many research and clinical applications. In this work we take advantage of the flow characteristics in microfluidic devices in which the bottom surface is patterned with slanted rectangular grooves to continuously fractionate blood. We exploit the flow in the vicinity of the patterned surface when the dimensions of the grooves are much smaller than the dimensions of the main channel. In these devices, we observed that the grooves act as open channels guiding flow along them with the flow over them being in the direction of the main channel. We present experiments in which the different blood components are deflected laterally to a different extent by the flow along the grooves depending on their sedimentation velocity, which allows their continuous fractionation. In particular, the heavier red blood cells experience the largest deflection while the lighter white blood cells deflect the least, allowing their passive and minimally invasive isolation. In addition, this fluidic platform can also be used to separate magnetically labeled circulating cancer cells which can be retained in the flow along the grooves using a sufficiently strong magnetic force.

  3. Performance optimization of grooved slippers for aero hydraulic pumps

    Directory of Open Access Journals (Sweden)

    Juan Chen

    2016-06-01

    Full Text Available A computational fluid dynamics (CFD simulation method based on 3-D Navier–Stokes equation and Arbitrary Lagrangian–Eulerian (ALE method is presented to analyze the grooved slipper performance of piston pump. The moving domain of grooved slipper is transformed into a fixed reference domain by the ALE method, which makes it convenient to take the effects of rotate speed, body force, temperature, and oil viscosity into account. A geometric model to express the complex structure, which covers the orifice of piston and slipper, vented groove and the oil film, is constructed. Corresponding to different oil film thicknesses calculated in light of hydrostatic equilibrium theory and boundary conditions, a set of simulations is conducted in COMSOL to analyze the pump characteristics and effects of geometry (groove width and radius, orifice size on these characteristics. Furthermore, the mechanics and hydraulics analyses are employed to validate the CFD model, and there is an excellent agreement between simulation and analytical results. The simulation results show that the sealing land radius, orifice size and groove width all dramatically affect the slipper behavior, and an optimum tradeoff among these factors is conducive to optimizing the pump design.

  4. Documentation of roller-bearing effect on butterfly inspired grooves

    Science.gov (United States)

    Gautam, Sashank; Lang, Amy

    2017-11-01

    Butterfly wings are covered with scales in a roof shingle pattern which align together to form grooves. The increase or decrease of laminar friction drag depends on the flow orientation to the scales. Flow in the longitudinal direction to the grooves encounters increased surface area which increases the friction drag. However, in the transverse direction, for low Re laminar flow, a single vortex is formed inside each groove and is predicted to remain stable due to the very low Re of the flow in each cavity. These embedded vortices act as roller bearings to the flow above, such that the fluid from the outer boundary layer does not mix with fluid inside the cavities. This leads to a reduction of skin friction drag when compared to a smooth surface. When the cavity flow Re is increased beyond a critical point, the vortex becomes unstable and the low-momentum fluid in the grooves mixes with the outer boundary layer flow, increasing the drag. The objective of this experiment is to determine the critical Re where the embedded vortex transitions from a stable to an unstable state using DPIV. Subsequently, for steady vortex conditions, a comparison of skin friction drag between the grooved and flat plate can show that the butterfly scaled surface can result in sub-laminar friction drag. The National Science Foundation (Grant No. 1335848).

  5. Design of pellet surface grooves for fission gas plenum

    International Nuclear Information System (INIS)

    Carter, T.J.; Jones, L.R.; Macici, N.; Miller, G.C.

    1986-01-01

    In the Canada deuterium uranium pressurized heavy water reactor, short (50-cm) Zircaloy-4 clad bundles are fueled on-power. Although internal void volume within the fuel rods is adequate for the present once-through natural uranium cycle, the authors have investigated methods for increasing the internal gas storage volume needed in high-power, high-burnup, experimental ceramic fuels. This present work sought to prove the methodology for design of gas storage volume within the fuel pellets - specifically the use of grooves pressed or machined into the relatively cool pellet/cladding interface. Preanalysis and design of pellet groove shape and volume was accomplished using the TRUMP heat transfer code. Postirradiation examination (PIE) was used to check the initial design and heat transfer assumptions. Fission gas release was found to be higher for the grooved pellet rods than for the comparison rods with hollow or unmodified pellets. This had been expected from the initial TRUMP thermal analyses. The ELESIM fuel modeling code was used to check in-reactor performance, but some modifications were necessary to accommodate the loss of heat transfer surface to the grooves. It was concluded that for plenum design purposes, circumferential pellet grooves could be adequately modeled by the codes TRUMP and ELESIM

  6. Surface sedimentation at permeable pavement systems

    DEFF Research Database (Denmark)

    Støvring, Jan; Dam, Torben; Jensen, Marina Bergen

    2018-01-01

    Newly installed permeable pavement (PP) systems provide high surface infiltration capacity, but the accumulation of sediments causes a decrease in capacity over time, eventually leading to surface clogging. With the aim of investigating local sedimentation processes and the importance of restorat......Newly installed permeable pavement (PP) systems provide high surface infiltration capacity, but the accumulation of sediments causes a decrease in capacity over time, eventually leading to surface clogging. With the aim of investigating local sedimentation processes and the importance...

  7. Fusing complementary images for pavement cracking measurements

    International Nuclear Information System (INIS)

    Yao, Ming; Zhao, Zuyun; Xu, Bugao; Yao, Xun

    2015-01-01

    Cracking is a major pavement distress that jeopardizes road serviceability and traffic safety. Automated pavement distress survey (APDS) systems have been developed using digital imaging technology to replace human surveys for more timely and accurate inspections. Most APDS systems require special lighting devices to illuminate pavements and prevent shadows of roadside objects that distort cracks in the image. Most artificial lighting devices are laser based, and are either hazardous to unprotected people or require dedicated power supplies on the vehicle. This study was aimed to develop a new imaging system that can scan pavement surface at highway speed and determine the level of severity of pavement cracking without using any artificial lighting. The new system consists of dual line-scan cameras that are installed side by side to scan the same pavement area as the vehicle moves. Cameras are controlled with different exposure settings so that both sunlit and shadowed areas can be visible in two separate images. The paired images contain complementary details useful for reconstructing an image in which the shadows are eliminated. This paper intends to present (1) the design of the dual line-scan camera system, (2) a new calibration method for line-scan cameras to rectify and register paired images, (3) a customized image-fusion algorithm that merges the multi-exposure images into one shadow-free image for crack detection, and (4) the results of the field tests on a selected road over a long period. (paper)

  8. Research on performance of upstream pumping mechanical seal with different deep spiral groove

    International Nuclear Information System (INIS)

    Wang, Q; Chen, H L; Liu, T; Liu, Y H; Liu, Z B; Liu, D H

    2012-01-01

    As one new type of mechanical seal, Upstream Pumping Mechanical Seal has been widely used in fluid machinery. In this paper, structure of spiral groove is innovatively optimized to improve performance of Upstream Pumping Mechanical Seal with Spiral Groove: keeping the dam zone and the weir zone not changed, changing the bottom shape of spiral groove only, substituting different deep spiral groove for equal deep spiral groove. The simulation on Upstream Pumping Mechanical Seal with different deep spiral grooves is done using FVM method. According to calculation, the performances of opening force and pressure distribution on seals face are obtained. Five types of spiral grooves are analyzed, namely equal deep spiral groove, circumferential convergent ladder-like different deep spiral groove, circumferential divergent ladder-like different deep spiral groove, radial convergent ladder-like different deep spiral groove and radial divergent ladder-like different deep spiral groove. This paper works on twenty-five working conditions. The results indicate the performances of circumferential divergent 2-ladder different deep spiral groove are better than the others, with more opening force and better stabilization, while with the same leakage. The outcome provides theoretical support for application of Upstream Pumping Mechanical Seal with circumferential convergent ladder-like different deep spiral groove.

  9. Research on performance of upstream pumping mechanical seal with different deep spiral groove

    Science.gov (United States)

    Wang, Q.; Chen, H. L.; Liu, T.; Liu, Y. H.; Liu, Z. B.; Liu, D. H.

    2012-11-01

    As one new type of mechanical seal, Upstream Pumping Mechanical Seal has been widely used in fluid machinery. In this paper, structure of spiral groove is innovatively optimized to improve performance of Upstream Pumping Mechanical Seal with Spiral Groove: keeping the dam zone and the weir zone not changed, changing the bottom shape of spiral groove only, substituting different deep spiral groove for equal deep spiral groove. The simulation on Upstream Pumping Mechanical Seal with different deep spiral grooves is done using FVM method. According to calculation, the performances of opening force and pressure distribution on seals face are obtained. Five types of spiral grooves are analyzed, namely equal deep spiral groove, circumferential convergent ladder-like different deep spiral groove, circumferential divergent ladder-like different deep spiral groove, radial convergent ladder-like different deep spiral groove and radial divergent ladder-like different deep spiral groove. This paper works on twenty-five working conditions. The results indicate the performances of circumferential divergent 2-ladder different deep spiral groove are better than the others, with more opening force and better stabilization, while with the same leakage. The outcome provides theoretical support for application of Upstream Pumping Mechanical Seal with circumferential convergent ladder-like different deep spiral groove.

  10. Nondestructive testing of pavements and pavement bases. (a bibliography with abstracts). Report for 1964-Jan 78

    International Nuclear Information System (INIS)

    Habercom, G.E. Jr.

    1978-01-01

    Nondestructive methods for quality assurance of pavements and pavement bases are investigated in these Government-sponsored research reports. Vibration, nuclear activation, radiometry, and acoustic detection are among the various techniques employed. The updated bibliography contains 114 abstracts, 17 of which are new entries to the previous edition

  11. Thermal stability analysis under embankment with asphalt pavement and cement pavement in permafrost regions.

    Science.gov (United States)

    Junwei, Zhang; Jinping, Li; Xiaojuan, Quan

    2013-01-01

    The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8 m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results.

  12. Flexible pavement rehabilitation design based on pavement service life time span left

    OpenAIRE

    Gamelyak, I.; Shevchuk, V.

    2005-01-01

    The design of flexible pavement rehabilitation is analysed in terms of durability-cost. A notion of the remaining service life span is described. the model of rehabilitation strategy selection is presented for both design project and operation stages. the results can be used in the pavement management system.

  13. Evaluation of various hot mix asphalt pavement thicknesses over rubblized concrete pavement.

    Science.gov (United States)

    2011-07-01

    In 1999, the Wisconsin DOT constructed two test sections as part of a rubblized PCC pavement project on I-39 to evaluate whether : increased HMA thickness could extend the pavement system's service life. Design thicknesses of the control and test sec...

  14. Reconsideration of tyre-pavement input parameters for the structural design of flexible pavements

    CSIR Research Space (South Africa)

    De Beer, Morris

    2006-08-01

    Full Text Available of modern truck tyres. Tyre-pavement contact stress measurements were carried out on a busy national road (N3) in South Africa from the port of Durban to the inland province of Gauteng. The three-dimensional tyre-pavement contact stress regimes of 45 227...

  15. Atypical olfactory groove meningioma associated with uterine fibromatosis; case report

    Directory of Open Access Journals (Sweden)

    Toma I. Papacocea

    2016-11-01

    Full Text Available The concomitant presence of the olfactory groove meningioma with uterine fibrosis is very rare. Our report presents the case of a giant olfactory groove meningioma revealed after a uterine fibroma resection in a 44 years-old female, due to a generalized seizure 10 days after operation. Cranial CT-scan identified the tumor as an olfactory groove meningioma. The tumor was operated with a macroscopically complete resection; the endothermal coagulation of the dura attachment was performed (Simpson II with a good postoperative evolution. Laboratory results showed the presence of receptors for steroid hormones both in meningioma and uterine tumor, and the histopathological examination revealed an atypical meningioma with 17% proliferation markers. Our findings suggest that even though meningiomas are benign tumors and a complete resection usually indicates a good prognosis, the association with uterine fibromatosis and the presence of high percentage of steroid receptors creates a higher risk to relapse, imposing therefore a good monitoring.

  16. Gap and channeled plasmons in tapered grooves: a review

    DEFF Research Database (Denmark)

    Smith, C. L. C.; Stenger, Nicolas; Kristensen, Anders

    2015-01-01

    Tapered metallic grooves have been shown to support plasmons - electromagnetically coupled oscillations of free electrons at metal-dielectric interfaces - across a variety of configurations and V-like profiles. Such plasmons may be divided into two categories: gap-surface plasmons (GSPs) that are......Tapered metallic grooves have been shown to support plasmons - electromagnetically coupled oscillations of free electrons at metal-dielectric interfaces - across a variety of configurations and V-like profiles. Such plasmons may be divided into two categories: gap-surface plasmons (GSPs...... platform to explore the fundamental science of plasmon excitations and their interactions. In this Review, we provide a research status update of plasmons in tapered grooves, starting with a presentation of the theory and important features of GSPs and CPPs, and follow with an overview of the broad range...

  17. Raphides with barbs and grooves in Xanthosoma sagittifolium (Araceae).

    Science.gov (United States)

    Sakai, W S; Hanson, M; Jones, R C

    1972-10-20

    Raphides in petioles of Xanthosoma sagittifolium are needlelike crystals about 50 micrometers long. The rectangular cross sections have maximum dimensions of approximately 850 by 250 nanometers. The raphides have two distinct end structures. One end is narrow, acute, and tapered to a point; the other is broad, acute, and abruptly pointed. Barbs, about 750 angstroms long with tips oriented away from the narrow end, occur along the length of the raphide on ridges on either side of two longitudinal grooves. These grooves, located opposite each other, give the raphide cross section an H-shape.

  18. Evaluating the performance of sustainable perpetual pavements using recycled asphalt pavement in China

    Directory of Open Access Journals (Sweden)

    Saud A. Sultan

    2016-10-01

    Full Text Available The vast highways network in China is moving from the phase of construction to the phase of maintenance, and with the introduction of new technique of perpetual pavement in last decade, it is necessary to consider recycling as one of the promising solutions for rehabilitation of old asphalt concrete pavement and ultimately to convert them into perpetual pavements. The aim is to reuse the existing pavement materials for several reasons, mainly to preserve natural resources such as aggregates, and to satisfy economic requirements by reducing the cost of highway construction and rehabilitation. A detailed testing program has been carried out on recycled asphalt pavements materials (RAP to evaluate their mechanical and structural characteristics to be used for the construction and rehabilitation of road pavements. Different types of RAP mixes have been stabilized by Portland cement to find the most suitable one from the point of view of design, construction, economy and environment. The analysis of life cycle costs has been carried out using system analysis and management of pavement program (SAMP5. The analysis of life cycle costs showed that the use of Portland cements with small percentages improves the structural characteristics of recycled asphalt materials to be used as stabilized base pavement layers for new or rehabilitated old road pavements and also for the construction and rehabilitation of perpetual pavements. A large amount of savings in construction and rehabilitation cost has been achieved by the use of stabilized RAP materials in addition to important contributions to the environment and preserving of natural resources.

  19. Long term pavement performance computed parameter : frost penetration

    Science.gov (United States)

    2008-11-01

    As the pavement design process moves toward mechanistic-empirical techniques, knowledge of seasonal changes in pavement structural characteristics becomes critical. Specifically, frost penetration information is necessary for determining the effect o...

  20. Investigation clogging dynamic of permeable pavement systems using embedded sensors

    Science.gov (United States)

    Permeable pavement is a stormwater control measure commonly selected in both new and retrofit applications. However, there is limited information about the clogging mechanism of these systems that effects the infiltration. A permeable pavement site located at the Seitz Elementary...

  1. Designing Base and Subbase to Resist Environmental Effects on Pavements

    Science.gov (United States)

    2018-02-02

    MnDOTs current pavement thickness design procedures do not characterize the effects of subgrade soil frost susceptibility. Previous research indicates frost action is the most severe environmental factor on pavement performance. The most accepted ...

  2. Density measurement verification for hot mix asphalt concrete pavement construction.

    Science.gov (United States)

    2010-06-01

    Oregon Department of Transportation (ODOT) requires a minimum density for the construction of dense-graded hot mix asphalt concrete (HMAC) pavements to ensure the likelihood that the pavement will not experience distresses that reduce the expected se...

  3. Density measurement verification for hot mixed asphalt concrete pavement construction.

    Science.gov (United States)

    2010-06-01

    Oregon Department of Transportation (ODOT) requires a minimum density for the construction of dense-graded hot mix asphalt concrete (HMAC) pavements to ensure the likelihood that the pavement will not experience distresses that reduce the expected se...

  4. Mobile geographic information system solution for pavement condition surveys [summary].

    Science.gov (United States)

    2012-01-01

    The State Materials Office (SMO) of the Florida : Department of Transportation (FDOT) performs : annual Pavement Condition Surveys (PCS) of : the Departments extensive pavement network. : This work is performed by single-person crews in : inertial...

  5. Evaluation of recycled concrete as aggregate in new concrete pavements.

    Science.gov (United States)

    2014-04-01

    This study evaluated the use of recycled concrete as coarse aggregate in new concrete pavements. : Recycled concrete aggregate (RCA) produced from demolished pavements in three geographically dispersed locations in Washington state were used to perfo...

  6. Overview of the South African mechanistic pavement design analysis method

    CSIR Research Space (South Africa)

    Theyse, HL

    1996-01-01

    Full Text Available A historical overview of the South African mechanistic pavement design method, from its development in the early 1970s to the present, is presented. Material characterization, structural analysis, and pavement life prediction are discussed...

  7. Software offers transparent, straightforward assessment of pavement additives : research spotlight.

    Science.gov (United States)

    2015-04-01

    Adding new materials to pavement layers is a proven technique to : improve performance. Many types of additivesfrom engineered : polymers and acids to recycled pavement, crumb rubber, shingles : and glasshave been used to help construct better ...

  8. Evaluation of microcracking and chemical deterioration in concrete pavements.

    Science.gov (United States)

    1995-10-31

    The major objective of this research project was to investigate the : chemistry and morphology of portland cement concrete pavements in : Iowa. The integrity of the various pavements was evaluated qualitatively, : based on the presence or absence of ...

  9. Exploration of Machine Learning Approaches to Predict Pavement Performance

    Science.gov (United States)

    2018-03-23

    Machine learning (ML) techniques were used to model and predict pavement condition index (PCI) for various pavement types using a variety of input variables. The primary objective of this research was to develop and assess PCI predictive models for t...

  10. A pavement management research program for Oregon highways : final report.

    Science.gov (United States)

    1989-12-01

    An extensive program was developed to measure pavement deflection skid resistance, and rideability throughout Oregon. The data from those "objective" measures were then evaluated for correlations with observed pavement distress and traffic factors. :...

  11. Advanced Automated Detection Analysis and Classification of Cracks in Pavement

    OpenAIRE

    Scott, Dennis

    2014-01-01

    Functional Session 5: Pavement Management Moderated by Akyiaa Hosten This presentation was held at the Pavement Evaluation 2014 Conference, which took place from September 15-18, 2014 in Blacksburg, Virginia. Presentation only

  12. Implementation of a pavement management system in Virginia.

    Science.gov (United States)

    1987-01-01

    The report summarizes the developments in pavement management in the Virginia Department of Transportation through late 1986. Included are discussions of the pavement management process with examples of priority programming, long-range projection of ...

  13. Variability of Pavement Distress Data From Manual Surveys

    OpenAIRE

    Daleiden, Jerome

    2014-01-01

    Functional Session 5: Pavement Management Moderated by Akyiaa Hosten This presentation was held at the Pavement Evaluation 2014 Conference, which took place from September 15-18, 2014 in Blacksburg, Virginia. Presentation only

  14. A pavement management research program for Oregon highways : interim report.

    Science.gov (United States)

    1985-03-01

    This is the first in a series of reports documenting progress on a statewide pavement management research project. The overall project is conducting research into pavement life cycles of different rehabilitation treatment; the cost-effectiveness of e...

  15. Evaluation of Procedures for Backcalculation of Airfield Pavement Moduli

    Science.gov (United States)

    2015-08-01

    ER D C/ G SL T R -1 5 -3 1 Evaluation of Procedures for Backcalculation of Airfield Pavement Moduli G eo te ch n ic al a n d S tr u...August 2015 Evaluation of Procedures for Backcalculation of Airfield Pavement Moduli Lucy P. Priddy and Carlos R. Gonzalez Geotechnical and...USAF’s) airfield pavement structural evaluation procedures. Determining the structural integrity of airfield pavement relies on the analysis of

  16. New Jersey Micro-Surface Pavement Noise Evaluation

    OpenAIRE

    Hencken, John; Haas, Edwin; Tulanowski, Michael; Bennert, Thomas

    2015-01-01

    New Jersey DOT is evaluating pavement preservation types for interstate resurfacing as a method to increase network pavement life cycles within depressed budgetary limits. Despite the economic benefits for micro-surface there is concern for the noise quality and pavement noise levels, which will become a significant issue to a greater population as the application increases over an increased area of lane miles throughout the state. Pavement noise research has been conducted on in-service pave...

  17. Precast concrete pavement - systems and performance review

    Science.gov (United States)

    Novak, Josef; Kohoutková, Alena; Křístek, Vladimír; Vodička, Jan

    2017-09-01

    Long-term traffic restrictions belong to the key disadvantages of conventional cast-in-plane concrete pavements which have been used for technical structures such as roads, parking place and airfield pavements. As a consequence, the pressure is put on the development of such systems which have short construction time, low production costs, long-term durability, low maintenance requirements etc.. The paper presents the first step in the development of an entirely new precast concrete pavement (PCP) system applicable to airfield and highway pavements. The main objective of the review of PCP systems is to acquire a better understanding of the current systems and design methods used for transport infrastructure. There is lack of information on using PCP systems for the construction of entirely new pavements. To most extensive experience is dated back to the 20th century when hexagonal slab panels and system PAG were used in the Soviet Union for the military airfields. Since cast-in-situ pavements became more common, the systems based on precast concrete panels have been mainly utilized for the removal of damaged sections of existing structures including roads, highways etc.. Namely, it concerns Fort Miller Super Slab system, Michigan system, Uretek Stitch system and Kwik system. The presented review indicates several issues associated with the listed PCP systems and their applications to the repair and rehabilitation of existing structures. Among others, the type of manufacturing technology, particularly the position of slots for dowel bars, affects the durability and performance of the systems. Gathered information serve for the development of a new system for airfield and highway pavement construction.

  18. 0-6673 : improvement in pavement ride, distress, and condition based on different pavement types : [project summary].

    Science.gov (United States)

    2013-08-01

    Each district is required to develop a 4-year : pavement management plan assigning project : treatment categories for the Pavement : Management Information System (PMIS). : However, there are different interpretations in : the districts about what tr...

  19. Evaluation of current Louisiana flexible pavement structures using PMS data and new M-E pavement design guide.

    Science.gov (United States)

    2010-10-01

    The proposed study uses the new MEPDG together with data available from LADOTDs Pavement Management System (PMS) and other data sources from LADOTDs main frame to evaluate typical flexible pavement structures currently used and to make changes ...

  20. Effect of age of permeable pavements on their infiltration function

    NARCIS (Netherlands)

    Boogaard, Floris; Lucke, Terry; Beecham, Simon

    This study describes field investigations designed to compare the infiltration capacities of 55 permeable pavement systems installed in the Netherlands and in Australia. The ages of the pavements varied from 1 to 12 years. Using infiltrometer testing, the performance of the pavements has been

  1. Pavement sound absorption measurements in the U.S.

    Science.gov (United States)

    2012-08-19

    In the U.S., the topic of pavement sound absorption in regard to tire-pavement noise has shown increased interest and research over the last several years. Four types of pavement sound absorption measurements with various applications are discussed: ...

  2. Knowledge Discovery and Pavement Performance : Intelligent Data Mining

    NARCIS (Netherlands)

    Miradi, M.

    2009-01-01

    The main goal of the study was to discover knowledge from data about asphalt road pavement problems to achieve a better understanding of the behavior of them and via this understanding improve pavement quality and enhance its lifespan. Four pavement problems were chosen to be investigated; raveling

  3. Effect of age of permeable pavements on their infiltration function

    NARCIS (Netherlands)

    Terry Lucke; ir. Floris Boogaard; Simon Beecham

    2013-01-01

    This study describes field investigations designed to compare the infiltration capacities of 55 permeable pavement systems installed in the Netherlands and in Australia. The ages of the pavements varied from 1 to 12 years. Using infiltrometer testing, the performance of the pavements has been

  4. Effectiveness of various public private partnership pavement rehabilitation treatments: A big data informatics survival analysis of pavement service life : final report.

    Science.gov (United States)

    2017-09-29

    Past research efforts have used a wide variety of methodological approaches to analyze pavement performance indicators, pavement rehabilitation treatments, and pavement service life. Using big data informatics methods, the intent of this study is to ...

  5. Tailoring channeled plasmon polaritons in metallic V-grooves

    DEFF Research Database (Denmark)

    Smith, Cameron; Thilsted, Anil Haraksingh; Marie, Rodolphe

    2013-01-01

    of propagating plasmons to optimize the trade-off between lateral confinement and loss [2]. Accordingly, the traits of CPPs in metallic V-grooves suggest their widespread implementation, with applications ranging from ultracompact photonic circuitry [3] to lab-on-a-chip sensing. Current CPP research focuses...

  6. Flow characterization in periodic microchannels containing asymmetric grooves

    Energy Technology Data Exchange (ETDEWEB)

    Osorio-Nesme, A; Delgado, A, E-mail: anuhar.nesme@fau.de [Institute of Fluid Mechanics, Friedrich-Alexander Erlangen-Nuremberg University, Cauerstrasse 4, D-91058 Erlangen (Germany)

    2017-10-15

    Characterization of two-dimensional flows in microchannels with anisotropic periodic grooves is numerically carried out by using the lattice Boltzmann method. Periodically placed microstructures, consisting of novel nozzle-diffuser-like grooves are deliberately designed to introduce a flow-direction dependent resistance. Simulations were conducted for a low-to-moderate Reynolds number in the laminar-transition flow regime. Different channel geometries, defined by the half-angle ϕ of the periodic grooves are considered. The influence of the half-angle on both the flow field and the onset of oscillatory flow regime at different driving body forces is analyzed. At a low Reynolds number, the flow is observed stationary and fully reversible, regardless of the groove geometry. In this regime, higher Reynolds numbers were observed when the geometry acts as a diffuser (negative flow) than as a nozzle (positive flow) for a given driving body force. At sufficiently high Reynolds number the flow turns from a steady state to a time-dependent oscillatory regime through a Hopf bifurcation. Successive flow bifurcations lead the flow structure from a periodic regime to a quasi-chaotic regime with three-dimensional structures. The onset of unsteady flow occurs earlier for positive flows and geometries with small half-angles. For higher driving forces, there is a reduction in the volume flow rate due to the advected material in the transversal direction, causing consequently a decrease in the Reynolds number. (paper)

  7. Syncopation, body-movement and pleasure in groove music.

    Science.gov (United States)

    Witek, Maria A G; Clarke, Eric F; Wallentin, Mikkel; Kringelbach, Morten L; Vuust, Peter

    2014-01-01

    Moving to music is an essential human pleasure particularly related to musical groove. Structurally, music associated with groove is often characterised by rhythmic complexity in the form of syncopation, frequently observed in musical styles such as funk, hip-hop and electronic dance music. Structural complexity has been related to positive affect in music more broadly, but the function of syncopation in eliciting pleasure and body-movement in groove is unknown. Here we report results from a web-based survey which investigated the relationship between syncopation and ratings of wanting to move and experienced pleasure. Participants heard funk drum-breaks with varying degrees of syncopation and audio entropy, and rated the extent to which the drum-breaks made them want to move and how much pleasure they experienced. While entropy was found to be a poor predictor of wanting to move and pleasure, the results showed that medium degrees of syncopation elicited the most desire to move and the most pleasure, particularly for participants who enjoy dancing to music. Hence, there is an inverted U-shaped relationship between syncopation, body-movement and pleasure, and syncopation seems to be an important structural factor in embodied and affective responses to groove.

  8. Novel scaffold design with multi-grooved PLA fibers

    International Nuclear Information System (INIS)

    Chung, Sangwon; King, Martin W; Gamcsik, Mike P

    2011-01-01

    A novel prototype nonwoven textile structure containing polylactide (PLA) multigrooved fibers has been proposed as a possible scaffold material for superior cell attachment and proliferation. Grooved cross-sectional fibers with larger surface area were obtained by a bi-component spinning system and the complete removal of the sacrificial component was confirmed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and x-ray photon spectroscopy (XPS) analysis. These PLA nonwoven scaffolds containing the grooved fibers exhibited enhanced wettability, greater flexibility and tensile properties, and a larger surface area compared to a traditional PLA nonwoven fabric containing round fibers. To evaluate cellular attachment on the two types of PLA nonwoven scaffolds, NIH 3T3 fibroblasts were cultured for up to 12 days. It was evident that the initial cellular attachment was superior on the scaffold with grooved fibers, which was confirmed by MTT viability assay (p < 0.01) and SEM analysis. In the future, by modulating the size of the grooves on the fibers, such a scaffold material with a large surface area could serve as an alternative matrix for culturing different types of cells.

  9. Syncopation, body-movement and pleasure in groove music.

    Directory of Open Access Journals (Sweden)

    Maria A G Witek

    Full Text Available Moving to music is an essential human pleasure particularly related to musical groove. Structurally, music associated with groove is often characterised by rhythmic complexity in the form of syncopation, frequently observed in musical styles such as funk, hip-hop and electronic dance music. Structural complexity has been related to positive affect in music more broadly, but the function of syncopation in eliciting pleasure and body-movement in groove is unknown. Here we report results from a web-based survey which investigated the relationship between syncopation and ratings of wanting to move and experienced pleasure. Participants heard funk drum-breaks with varying degrees of syncopation and audio entropy, and rated the extent to which the drum-breaks made them want to move and how much pleasure they experienced. While entropy was found to be a poor predictor of wanting to move and pleasure, the results showed that medium degrees of syncopation elicited the most desire to move and the most pleasure, particularly for participants who enjoy dancing to music. Hence, there is an inverted U-shaped relationship between syncopation, body-movement and pleasure, and syncopation seems to be an important structural factor in embodied and affective responses to groove.

  10. VALIDITY OF GARBER MODEL IN PREDICTING PAVEMENT CONDITION INDEX OF FLEXIBLE PAVEMENT IN KERBALA CITY

    Directory of Open Access Journals (Sweden)

    Hussein A. Ewadh

    2018-05-01

    Full Text Available Pavement Condition Index (PCI is one of the important basics in pavement maintenance management system (PMMS, and it is used to evaluate the current and future pavement condition. This importantance in decision making to limit the maintenance needs, types of treatment, and maintenance priority. The aim of this research is to estimate the PCI value for flexible pavement urban roads in the study area (kerbala city by using Garber et al. developed model. Based on previous researches, data are collected for variables that have a significant impact on pavement condition. Data for pavement age (AGE, average daily traffic (ADT, and structural number (SN were collected for 44 sections in the network roads. A field survey (destructive test (core test and laboratory test (Marshall Test were used to determine the capacity of structure layer of pavement (SN. The condition index (CI output from a developed model was compared with the PCI output of PAVER 6.5.7 by using statistical analysis test. The developed model overestimates value of CI rather than PCI estimated from PAVER 6.5.7 due to statistical test to a 95% degree of confidence, (R = 0.771 for 44 sections (arterial and collector.

  11. Study on road surface source pollution controlled by permeable pavement

    Science.gov (United States)

    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.

  12. The complex radicular groove: interdisciplinary management with mineral trioxide aggregate and bone substitute.

    Science.gov (United States)

    Narmatha, V J; Thakur, Sophia; Shetty, Sheetal; Bali, Praveen Kumar

    2014-11-01

    This article is a case report of the successful interdisciplinary management of a maxillary lateral incisor with a deep palatogingival groove. The tooth presented with severe periodontal destruction owing to the deep extension of the groove up to the root apex. The groove was meticulously diagnosed and treated by endodontic and subsequent periodontal surgery leading to complete resolution of the pathological process.

  13. Optical microtopographic inspection of asphalt pavement surfaces

    Science.gov (United States)

    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.

  14. Quantitative analysis of microtubule orientation in interdigitated leaf pavement cells.

    Science.gov (United States)

    Akita, Kae; Higaki, Takumi; Kutsuna, Natsumaro; Hasezawa, Seiichiro

    2015-01-01

    Leaf pavement cells are shaped like a jigsaw puzzle in most dicotyledon species. Molecular genetic studies have identified several genes required for pavement cells morphogenesis and proposed that microtubules play crucial roles in the interdigitation of pavement cells. In this study, we performed quantitative analysis of cortical microtubule orientation in leaf pavement cells in Arabidopsis thaliana. We captured confocal images of cortical microtubules in cotyledon leaf epidermis expressing GFP-tubulinβ and quantitatively evaluated the microtubule orientations relative to the pavement cell growth axis using original image processing techniques. Our results showed that microtubules kept parallel orientations to the growth axis during pavement cell growth. In addition, we showed that immersion treatment of seed cotyledons in solutions containing tubulin polymerization and depolymerization inhibitors decreased pavement cell complexity. Treatment with oryzalin and colchicine inhibited the symmetric division of guard mother cells.

  15. "Full-Scale Testing of Pavement Response"

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ekdahl, Peter

    1998-01-01

    Three pavement sections in southern Sweden were instrumented in late 1991. Each section have instruments for measuring the strain at the bottom of the asphalt layer, vertical stress and strains in the subgrade and temperatures at different depths. The purpose was to evaluate different theoretical...... methods for determining stresses, strains and deflections in pavement structurers.Falling Weight Deflectometer (FWD) test were done on the test sections, and stresses and strains were measured both under FWD loading and under a rolling wheel load. Different back-analysis procedures were used to derive...

  16. The Inhabitants of the Historical Pavement

    DEFF Research Database (Denmark)

    2016-01-01

    and boulevards to kiosks and cigarette packs.This particular excerpt presents a framed view of a quasi-historical pavement in downtown Chicago and the coming and going of people. Some are passing by without paying much attention, for others it is their daily workplace and for some an exotic starting point...... for yet unknown adventures. The pavement and collective history will outlast all of them – but while they are here, they set each other in motion and even the most trivial elements of the street become part of this choreography.Throughout the film, the reciprocal relationship between the individual...

  17. Interim revision of the South African Mechanistic-Empirical pavement design method for flexible pavements

    CSIR Research Space (South Africa)

    Theyse, HL

    2011-09-01

    Full Text Available Pavement design methods, in combination with network level management systems must enable road authorities to develop reliable long-term financial plans based on the estimated structural capacity of the road network. Inaccurate design models...

  18. Tyre-pavement interface contact stresses on flexible pavements - quo vadis?

    CSIR Research Space (South Africa)

    De Beer, Morris

    2004-09-01

    Full Text Available on tyre inflation pressure on this route is also given. The paper also discusses an improved definition of the actual tyre/pavement interaction of modern heavy vehicles and their loads on the current flexible road infrastructure....

  19. Performance studies of continuously reinforced concrete pavement : pavements without transverse steel.

    Science.gov (United States)

    1972-01-01

    The status of studies of the three continuously reinforced pavement projects near Charlottesville is reported. Of particular interest in these studies are the effects of the elimination of transverse reinforcing steel, the changing characteristics of...

  20. Development of index based pavement performance models for pavement management system (PMS) of LADOTD : tech summary.

    Science.gov (United States)

    2009-03-01

    A research study was initiated by the Louisiana Department of Transportation and Development (LADOTD) in conjunction with the : Federal Highway Administration (FHWA) to evaluate the overall performance and eff ectiveness of LADOTDs Pavement Manage...

  1. Development of index based pavement performance models for pavement management system (PMS) of LADOTD.

    Science.gov (United States)

    2009-03-01

    This report focuses on pavement performance and treatment models for Louisiana Department of : Transportation and Development (LADOTD) and is in continuation of Louisiana Transportation : Research Center (LTRC) Report No. 430 Development of Unifor...

  2. Development of Pavement Condition Index Model Using PAVER 6.5.7 for Flexible Pavement Urban Roads in Kerbala City

    Directory of Open Access Journals (Sweden)

    Hussein Ali Ewadh

    2017-08-01

    Full Text Available The pavement condition index (PCI is an important factor indicating pavement condition of roads. The pavement is one of the basic parts of the road infrastructure. Accordingly the aim of this paper is to develop a pavement condition index model using PAVER 6.5.7 for a flexible pavement urban roads in the Kerbala city center. The development model is depending on the PCI value of 109 sample sections having 57.8 km length, Data collected for pavement distress (type, dimension, and severity were used to find PCI. The filtering and outlier analysis was done by using a polynomial (fourth-degree constrained least squared for statistical process. These processes were done by (PAVER 6.5.7 software. The result of the prediction model of PCI shows that it is valid to be used in the prediction of the condition of pavement for the same family type

  3. Numerical investigation of the effects of geometric parameters on transverse motion with slanted-groove micro-mixers

    Energy Technology Data Exchange (ETDEWEB)

    Baik, Seung Joo; Cho, Jae Yong; Choi, Se Bin; Lee, Joon Sang [School of Mechanical Engineering, Yonsei University, Seoul (Korea, Republic of)

    2016-08-15

    We investigated hydrodynamic phenomena inside several passive microfluidic mixers using a Lattice Boltzmann method (LBM) based on particle mesoscopic kinetic equations. Mixing processes were simulated in a Slanted grooved micro-mixer (SGM), a Staggered herringbone grooved micro-mixer (SHM), and a Bi-layered staggered herringbone grooved micro-mixer (BSHM). Then, the effects of six geometric mixer parameters (i.e., groove height to channel height ratio, groove width to groove pitch length ratio, groove pitch to groove height ratio, groove intersection angle, herringbone groove asymmetric ratio and bi-layered groove asymmetric ratio) on mixing were investigated using computed cross-flow velocity and helicity density distributions in the flow cross-section. We demonstrated that helicity density provides sufficient information to analyze micro helical motion within a micro-mixer, allowing for micro-mixer design optimization.

  4. Grooved windows for scintillation crystals and light pipes of high refractive index

    International Nuclear Information System (INIS)

    Swinehart, C.F.

    1975-01-01

    Scintillation crystals are disclosed which have improved resolution and pulse height. An improved crystal has shallow grooves or spot depressions cut in the window, usually an end surface. Typical grooves are about 1.5 mm wide and about .1 mm deep. The grooves may be either horizontal, generally parallel grooves in spaced apart relationship, or concentric rings in radially spaced apart relationship. A light pipe of high refractive index, such as a crystal of pure sodium iodide, may also be improved with shallow grooves or spot depressions cut in an end surface

  5. Unified design of sinusoidal-groove fused-silica grating.

    Science.gov (United States)

    Feng, Jijun; Zhou, Changhe; Cao, Hongchao; Lu, Peng

    2010-10-20

    A general design rule of deep-etched subwavelength sinusoidal-groove fused-silica grating as a highly efficient polarization-independent or polarization-selective device is studied based on the simplified modal method, which shows that the device structure depends little on the incident wavelength, but mainly on the ratio of groove depth to incident wavelength and the ratio of wavelength to grating period. These two ratios could be used as the design guidelines for wavelength-independent structure from deep ultraviolet to far infrared. The optimized grating profile with a different function as a polarizing beam splitter, a polarization-independent two-port beam splitter, or a polarization-independent grating with high efficiency of -1st order is obtained at a wavelength of 1064 nm, and verified by using the rigorous coupled-wave analysis. The performance of the sinusoidal grating is better than a conventional rectangular one, which could be useful for practical applications.

  6. Dance, Music, Meter and Groove: A Forgotten Partnership

    Directory of Open Access Journals (Sweden)

    W Tecumseh eFitch

    2016-03-01

    Full Text Available I argue that core aspects of musical rhythm, especially groove and syncopation, can only be fully understood in the context of their origins in the participatory social experience of dance. Musical meter is first considered in the context of bodily movement. I then offer an interpretation of the pervasive but somewhat puzzling phenomenon of syncopation in terms of acoustic emphasis on certain offbeat components of the accompanying dance style. The reasons for the historical tendency of many musical styles to divorce themselves from their dance-based roots are also briefly considered. To the extent that musical rhythms only make sense in the context of bodily movement, researchers interested in ecologically valid approaches to music cognition should make a more concerted effort to extend their analyses to dance, particularly if we hope to understand the cognitive constraints underlying rhythmic aspects of music like meter and groove.

  7. Dance, Music, Meter and Groove: A Forgotten Partnership.

    Science.gov (United States)

    Fitch, W Tecumseh

    2016-01-01

    I argue that core aspects of musical rhythm, especially "groove" and syncopation, can only be fully understood in the context of their origins in the participatory social experience of dance. Musical meter is first considered in the context of bodily movement. I then offer an interpretation of the pervasive but somewhat puzzling phenomenon of syncopation in terms of acoustic emphasis on certain offbeat components of the accompanying dance style. The reasons for the historical tendency of many musical styles to divorce themselves from their dance-based roots are also briefly considered. To the extent that musical rhythms only make sense in the context of bodily movement, researchers interested in ecologically valid approaches to music cognition should make a more concerted effort to extend their analyses to dance, particularly if we hope to understand the cognitive constraints underlying rhythmic aspects of music like meter and groove.

  8. Hydrodynamic simulations of microjetting from shock-loaded grooves

    Science.gov (United States)

    Roland, C.; de Rességuier, T.; Sollier, A.; Lescoute, E.; Soulard, L.; Loison, D.

    2017-01-01

    The interaction of a shock wave with a free surface which has geometrical defects, such as cavities or grooves, may lead to the ejection of micrometric debris at velocities of km/s. This process can be involved in many applications, like pyrotechnics or industrial safety. Recent laser shock experiments reported elsewhere in this conference have provided some insight into jet formation as well as jet tip velocities for various groove angles and shock pressures. Here, we present hydrodynamic simulations of these experiments, in both 2D and 3D geometries, using both finite element method and smoothed particle hydrodynamics. Numerical results are compared to several theoretical predictions including the Richtmyer-Meshkov instabilities. The role of the elastic-plastic behavior on jet formation is illustrated. Finally, the possibility to simulate the late stage of jet expansion and fragmentation is explored, to evaluate the mass distribution of the ejecta and their ballistic properties, still essentially unknown in the experiments.

  9. Numerical analysis of lateral illumination lightpipes using elliptical grooves

    Science.gov (United States)

    Sánchez-Guerrero, Guillermo E.; Viera-González, Perla M.; Martínez-Guerra, Edgar; Ceballos-Herrera, Daniel E.

    2017-09-01

    Lightpipes are used for illumination in applications such as back-lighting or solar cell concentrators due to the high irradiance uniformity, but its optimal design requires several parameters. This work presents a procedure to design a square lightpipe to control the light-extraction on its lateral face using commercial LEDs placed symmetrically in the lightpipe frontal face. We propose the use of grooves using total internal reflection placed successively in the same face of extraction to control the area of emission. The LED area of emission is small compared with the illuminated area, and, as expected, the lateral face total power is attenuated. These grooves reduce the optical elements in the system and can control areas of illumination. A mathematical and numerical analysis are presented to determine the dependencies on the light-extraction.

  10. Condensation and Evaporation Transitions in Deep Capillary Grooves

    OpenAIRE

    Malijevský, A. (Alexandr); Parry, A.O.

    2014-01-01

    We study the order of capillary condensation and evaporation transitions of a simple fluid adsorbed in a deep capillary groove using a fundamental measure density functional theory (DFT). The walls of the capillary interact with the fluid particles via long-ranged, dispersion, forces while the fluid-fluid interaction is modelled as a truncated Lennard-Jones-like potential. We find that below the wetting temperature $T_w$ condensation is first-order and evaporation is continuous with the metas...

  11. Development of New Bituminous Pavement Design Method

    DEFF Research Database (Denmark)

    Ullidtz, Per

    The report and work of COST Action 333 sets in place the foundation for a coherent, cost-effective and harmonised European pavement design method. In order to do this, the work programme focused on information gathering, identification of requirements and the selection of the necessary design...

  12. Viscoelastic Pavement Modeling with a Spreadsheet

    DEFF Research Database (Denmark)

    Levenberg, Eyal

    2016-01-01

    The aim herein was to equip civil engineers and students with an advanced pavement modeling tool that is both easy to use and highly adaptive. To achieve this, a mathematical solution for a layered viscoelastic half-space subjected to a moving load was developed and subsequently implemented...

  13. The Reflective Cracking in Flexible Pavements

    Directory of Open Access Journals (Sweden)

    Pais Jorge

    2013-07-01

    Full Text Available Reflective cracking is a major concern for engineers facing the problem of road maintenance and rehabilitation. The problem appears due to the presence of cracks in the old pavement layers that propagate into the pavement overlay layer when traffic load passes over the cracks and due to the temperature variation. The stress concentration in the overlay just above the existing cracks is responsible for the appearance and crack propagation throughout the overlay. The analysis of the reflective cracking phenomenon is usually made by numerical modeling simulating the presence of cracks in the existing pavement and the stress concentration in the crack tip is assessed to predict either the cracking propagation rate or the expected fatigue life of the overlay. Numerical modeling to study reflective cracking is made by simulating one crack in the existing pavement and the loading is usually applied considering the shear mode of crack opening. Sometimes the simulation considers the mode I of crack opening, mainly when temperature effects are predominant.

  14. Relationship between road pavement failures, engineering indices ...

    African Journals Online (AJOL)

    This article presents the results of a study carried out to relate the frequency of pavement failures, the engineering indices of the subgrade materials and the underlying geology. The results show a high variability in the indices such as the liquid limit, LL, the plasticity index, PI, the maximum dry density, MDD, the optimum ...

  15. Pavement evaluation using a portable lightweight deflectometer.

    Science.gov (United States)

    2012-12-01

    The use of Zorn ZFG-3000 portable Lightweight Deflectometer (LWD) in the in-situ : assessment of pavement quality was investigated in this research. A lower load and a : shorter load pulse duration are used in a LWD as compared to a Falling Weight : ...

  16. Lessons learned : pavement marking warranty contract.

    Science.gov (United States)

    2013-12-01

    In 2012, UDOT implemented a performance-based warranty on a portion of an I-15 pavement marking : project. The awarded contract requested a contractor warranty on the implemented markings for a total : duration of six years. This is the first time th...

  17. Texas perpetual pavements : new design guidelines.

    Science.gov (United States)

    2010-06-01

    Since 2001, the State of Texas has been designing and constructing perpetual pavements : on some of its heavily trafficked highways where the expected 20-year truck-traffic estimate of : 18 kip ESALs is in excess of 30 million (TxDOT, 2001). To date,...

  18. Cracking of open traffic rigid pavement

    Directory of Open Access Journals (Sweden)

    Niken Chatarina

    2017-01-01

    Full Text Available The research is done by observing the growth of real structure cracking in Natar, Lampung, Indonesia compared to C. Niken’s et al research and literature study. The rigid pavement was done with open traffic system. There are two main crack types on Natar rigid pavement: cracks cross the road, and cracks spreads on rigid pavement surface. The observation of cracks was analyzed by analyzing material, casting, curing, loading and shrinkage mechanism. The relationship between these analysis and shrinkage mechanism was studied in concrete micro structure. Open traffic make hydration process occur under vibration; therefore, fresh concrete was compressed and tensioned alternately since beginning. High temperature together with compression, cement dissociation, the growth of Ca2+ at very early age leads abnormal swelling. No prevention from outside water movement leads hydration process occur with limited water which caused spreads fine cracks. Limited water improves shrinkage and plastic phase becomes shorter; therefore, rigid pavement can’t accommodate the abnormal swelling and shrinking alternately and creates the spread of cracks. Discontinuing casting the concrete makes both mix under different condition, the first is shrink and the second is swell and creates weak line on the border; so, the cracks appear as cracks across the road.

  19. Pavement management system for City of Madison.

    Science.gov (United States)

    2016-11-01

    This project aims to implement a pavement management system (PMS) for the City of Madison using : four specific objectives: 1) build a city-wide GIS database for PMS compatible and incorporable with the : citys GIS system; 2) identify feasible pav...

  20. Effectiveness of weed control methods on pavement

    NARCIS (Netherlands)

    Vermeulen, G.D.; Verwijs, B.R.; Kempenaar, C.

    2007-01-01

    The policy in the Netherlands is to signifiantly reduce the use of herbicides, also on pavements. Existing non-chemical methods to control weeds are much less effective than spot spraying, the usual method at this moment. Therefore, the cost of non-chemical weed management is often estimated to be 4

  1. Groove Pancreatitis – A Mimic of Pancreatic and Periampullary Tumors

    Directory of Open Access Journals (Sweden)

    Sivakami R Pradheepkumar

    2017-10-01

    Full Text Available Groove Pancreatitis (GP is a rare form of focal chronic pancreatitis involving the pancreatico-duodenal groove (PDG. GP was first described by Becker in 1973. Though, GP has been described so many years ago, it is still unfamiliar among most physicians because of lack of sufficient case studies and clinical similarity of GP to conventional pancreatitis. Imaging based differentiation of GP from other lesions, like pancreatic and periampullary adenocarcinoma is also not possible in all the cases, unless there are typical findings favoring GP. Since, the line of treatment and outcome is totally different in these two conditions, appreciation of the fine differences between these two entities is very significant. Groove pancreatitis is symptomatically treated with medicines and only for patients with continuous and severe symptoms which are not amenable to medical treatment surgical management is considered. Radiological differentiation of GP from pancreatic and periampullary malignancies will help to avoid unnecessary surgery in the initial stages. We report two cases of GP, one of pure and other of segmental form where we found typical imaging features which pointed to the diagnosis of GP with a small discussion about the Computed tomography (CT and Magnetic Resonance Imaging (MRI appearance of this entity as well as its differential diagnosis.

  2. Permanent deformation and deflection relationship from pavement condition assessment

    Directory of Open Access Journals (Sweden)

    Fabricio Leiva-Villacorta

    2017-07-01

    Full Text Available The development of permanent deformation in flexible pavements has been a research topic for several decades. Currently there are models included in the structural design of pavements that can predict this type of failure. However, the variables required for the prediction of this distress are complex or difficult to obtain in the field, making its application in pavement evaluation also difficult. Measurement of the deflection of pavement structures by means of non-destructive testing is a technique used to assess the condition of the pavement. This research study seeks to correlate data from deflections of the pavement surface with probable permanent deformation in time. In addition, prediction of the remaining life of the pavement structure using a specified criterion is also analyzed. In order to accomplish these objectives, data acquired from 4 different full scale accelerated pavement test tracks was used to develop a permanent deformation model as a function of deflection, load repetitions and pavement layer thickness. The developed model considered a time series model that incorporates an Auto-regressive parameter of order 1. The proposed model presents an advantage over currently available models because it reduces the required parameters to predict the permanent deformation and/or remaining life in the structure and because these variables can be easily found and updated in a pavement management system. Keywords: HVS, Permanent deformation, Deflections, APT, Time series, Instrumentation

  3. Developing a network-level structural capacity index for structural evaluation of pavements.

    Science.gov (United States)

    2013-03-01

    The objective of this project was to develop a structural index for use in network-level pavement evaluation to facilitate : the inclusion of the pavements structural condition in pavement management applications. The primary goal of network-level...

  4. On-board sound intensity tire-pavement noise study in North Carolina.

    Science.gov (United States)

    2011-12-01

    "This research investigated tire-pavement noise on various types of pavements across North Carolina by using On- : Board Sound Intensity (OBSI) method. To mitigate traffic noise, quieter pavement may provide advantages that : noise barriers cannot. T...

  5. Determination of coefficient of thermal expansion effects on Louisiana's PCC pavement design.

    Science.gov (United States)

    2011-12-01

    With the development of the Mechanistic Empirical Pavement Design Guide (MEPDG) as a new pavement design tool, the : coefficient of thermal expansion (CTE) is now considered a more important design parameter in estimating pavement : performance inclu...

  6. Determination of coefficient of thermal expansion for Portland Cement Concrete pavements for MEPDG Implementation

    Science.gov (United States)

    2012-10-01

    The Coefficient of Thermal Expansion (CTE) is an important parameter in Portland Cement Concrete (PCC) pavement analysis and design as it is directly proportional to the magnitude of temperature-related pavement deformations throughout the pavement s...

  7. Integration of pavement cracking prediction model with asset management and vehicle-infrastructure interaction models.

    Science.gov (United States)

    2015-01-01

    Not long after the construction of a pavement or a new pavement surface, various : forms of deterioration begin to accumulate due to the harsh effects of traffic loading : combined with weathering action. In a recent NEXTRANS project, a pavement crac...

  8. Predicting pavement condition index using international roughness index in Washington DC.

    Science.gov (United States)

    2014-09-01

    A number of pavement condition indices are used to conduct pavement management assessments, two of which are the : International Roughness Index (IRI) and Pavement Condition Index (PCI). The IRI is typically measured using specialized : equipment tha...

  9. A link of full-scale accelerated pavement testing to long-term pavement performance study in the Western Cape Province of South Africa

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph K

    2016-09-01

    Full Text Available of Accelerated Pavement Testing in Pavement Sustainability A Link of Full-Scale Accelerated Pavement Testing to Long-Term Pavement Performance Study in the Western Cape Province of South Africa J. K. Anochie-Boateng W. JvdM Steyn C. Fisher L. Truter...

  10. Molecular mechanisms controlling pavement cell shape in Arabidopsis leaves.

    Science.gov (United States)

    Qian, Pingping; Hou, Suiwen; Guo, Guangqin

    2009-08-01

    Pavement cells have an interlocking jigsaw puzzle-shaped leaf surface pattern. Twenty-three genes involved in the pavement cell morphogenesis were discovered until now. The mutations of these genes through various means lead to pavement cell shape defects, such as loss or lack of interdigitation, the reduction of lobing, gaps between lobe and neck regions in pavement cells, and distorted trichomes. These phenotypes are affected by the organization of microtubules and microfilaments. Microtubule bands are considered corresponding with the neck regions of the cell, while lobe formation depends on patches of microfilaments. The pathway of Rho of plant (ROP) GTPase signaling cascades regulates overall activity of the cytoskeleton in pavement cells. Some other proteins, in addition to the ROPs, SCAR/WAVE, and ARP2/3 complexes, are also involved in the pavement cell morphogenesis.

  11. Assessing Asphalt and Concrete Pavement Surface Texture in the Field

    OpenAIRE

    Saad I. Sarsam; Huda N. Al Shareef

    2016-01-01

    The incorporation of safety characteristics into the traditional pavement structural design or in the functional evaluation of pavement condition has not been established yet. The design has focused on the structural capacity of the roadway so that the pavement can withstand specific level of repetitive loading over the design life. On the other hand, the surface texture condition was neither included in the AASHTO design procedure nor in the present serviceability index measurements. The ...

  12. Crushing damage estimation for pavement with lightly cementitious bases

    CSIR Research Space (South Africa)

    De Beer, Morris

    2014-07-01

    Full Text Available . Department of Transport. Pretoria, South Africa. Litwinowicz and De Beer., 2013. Long term crushing performance of lightly cementitious pavement materials – update to the South African procedures. Road Materials and Pavement Design. Maina, J.W., De... Beer, M. and van Rensburg, Y., 2013. Modelling Tyre-Road Contact Stresses in Pavement Design and Analysis. Proceedings of 32nd Southern Africa transport conference, Pretoria, July 2013. pp 336-345: SAPDM, (2014). http://www.sapdm.co.za/, last...

  13. Dynamic Modeling of Pavements with Application to Deflection Measurements

    DEFF Research Database (Denmark)

    Madsen, Stine Skov

    Pavement surface deflection measurements are the primary means of evaluating the bearing capacity of a pavement. The most common type of device used for measuring pavement surface deflections is the Falling Weight Deflectometer (FWD). However, increasing attention has been given to the Rolling Wheel...... Deflectometer (RWD) type of device due to its ability to measure deflections continuously while driving at traffic speed. To be able to properly interpret deflection measurements from an RWD device, more knowledge about the structural behavior of a pavement when subjected to transient dynamic loads moving...

  14. Hybrid green permeable pave with hexagonal modular pavement systems

    International Nuclear Information System (INIS)

    Rashid, M A; Abustan, I; Hamzah, M O

    2013-01-01

    Modular permeable pavements are alternatives to the traditional impervious asphalt and concrete pavements. Pervious pore spaces in the surface allow for water to infiltrate into the pavement during rainfall events. As of their ability to allow water to quickly infiltrate through the surface, modular permeable pavements allow for reductions in runoff quantity and peak runoff rates. Even in areas where the underlying soil is not ideal for modular permeable pavements, the installation of under drains has still been shown to reflect these reductions. Modular permeable pavements have been regarded as an effective tool in helping with stormwater control. It also affects the water quality of stormwater runoff. Places using modular permeable pavement has been shown to cause a significant decrease in several heavy metal concentrations as well as suspended solids. Removal rates are dependent upon the material used for the pavers and sub-base material, as well as the surface void space. Most heavy metals are captured in the top layers of the void space fill media. Permeable pavements are now considered an effective BMP for reducing stormwater runoff volume and peak flow. This study examines the extent to which such combined pavement systems are capable of handling load from the vehicles. Experimental investigation were undertaken to quantify the compressive characteristics of the modular. Results shows impressive results of achieving high safety factor for daily life vehicles.

  15. Study on Flexible Pavement Failures in Soft Soil Tropical Regions

    Science.gov (United States)

    Jayakumar, M.; Chee Soon, Lee

    2015-04-01

    Road network system experienced rapid upgrowth since ages ago and it started developing in Malaysia during the colonization of British due to its significant impacts in transportation field. Flexible pavement, the major road network in Malaysia, has been deteriorating by various types of distresses which cause descending serviceability of the pavement structure. This paper discusses the pavement condition assessment carried out in Sarawak and Sabah, Malaysia to have design solutions for flexible pavement failures. Field tests were conducted to examine the subgrade strength of existing roads in Sarawak at various failure locations, to assess the impact of subgrade strength on pavement failures. Research outcomes from field condition assessment and subgrade testing showed that the critical causes of pavement failures are inadequate design and maintenance of drainage system and shoulder cross fall, along with inadequate pavement thickness provided by may be assuming the conservative value of soil strength at optimum moisture content, whereas the exiting and expected subgrade strengths at equilibrium moisture content are far below. Our further research shows that stabilized existing recycled asphalt and base materials to use as a sub-base along with bitumen stabilized open graded base in the pavement composition may be a viable solution for pavement failures.

  16. Crack identification for rigid pavements using unmanned aerial vehicles

    Science.gov (United States)

    Bahaddin Ersoz, Ahmet; Pekcan, Onur; Teke, Turker

    2017-09-01

    Pavement condition assessment is an essential piece of modern pavement management systems as rehabilitation strategies are planned based upon its outcomes. For proper evaluation of existing pavements, they must be continuously and effectively monitored using practical means. Conventionally, truck-based pavement monitoring systems have been in-use in assessing the remaining life of in-service pavements. Although such systems produce accurate results, their use can be expensive and data processing can be time consuming, which make them infeasible considering the demand for quick pavement evaluation. To overcome such problems, Unmanned Aerial Vehicles (UAVs) can be used as an alternative as they are relatively cheaper and easier-to-use. In this study, we propose a UAV based pavement crack identification system for monitoring rigid pavements’ existing conditions. The system consists of recently introduced image processing algorithms used together with conventional machine learning techniques, both of which are used to perform detection of cracks on rigid pavements’ surface and their classification. Through image processing, the distinct features of labelled crack bodies are first obtained from the UAV based images and then used for training of a Support Vector Machine (SVM) model. The performance of the developed SVM model was assessed with a field study performed along a rigid pavement exposed to low traffic and serious temperature changes. Available cracks were classified using the UAV based system and obtained results indicate it ensures a good alternative solution for pavement monitoring applications.

  17. Incorporating moving dynamic tyre loads in pavement design and analysis

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2000-07-01

    Full Text Available at the University of Pretoria. 4 REAL LIFE TYRE LOADS Characterisation Pavement loading has been shown by various authors to be a dynamic (time-dependent) phenomenon (Divine, 1997; Cebon, 1999). A pavement experiences a vehicle as a moving, time-varying set... frequencies. Body bounce generally dominates the dynamic loading, and is mainly caused by the response of the sprung mass of the vehicle to the pavement roughness. Axle hop becomes more significant at higher vehicle speeds and higher pavement roughnesses...

  18. Proactive pavement asset management with climate change aspects

    Science.gov (United States)

    Zofka, Adam

    2018-05-01

    Pavement Asset Management System is a systematic and objective tool to manage pavement network based on the rational, engineering and economic principles. Once implemented and mature Pavement Asset Management System serves the entire range of users starting with the maintenance engineers and ending with the decision-makers. Such a system is necessary to coordinate agency management strategy including proactive maintenance. Basic inputs in the majority of existing Pavement Asset Management System approaches comprise the actual pavement inventory with associated construction history and condition, traffic information as well as various economical parameters. Some Pavement Management System approaches include also weather aspects which is of particular importance considering ongoing climate changes. This paper presents challenges in implementing the Pavement Asset Management System for those National Road Administrations that manage their pavement assets using more traditional strategies, e.g. worse-first approach. Special considerations are given to weather-related inputs and associated analysis to demonstrate the effects of climate change in a short- and long-term range. Based on the presented examples this paper concludes that National Road Administrations should account for the weather-related factors in their Pavement Management Systems as this has a significant impact on the system outcomes from the safety and economical perspective.

  19. Synthesis and characterization of DNA minor groove binding alkylating agents.

    Science.gov (United States)

    Iyer, Prema; Srinivasan, Ajay; Singh, Sreelekha K; Mascara, Gerard P; Zayitova, Sevara; Sidone, Brian; Fouquerel, Elise; Svilar, David; Sobol, Robert W; Bobola, Michael S; Silber, John R; Gold, Barry

    2013-01-18

    Derivatives of methyl 3-(1-methyl-5-(1-methyl-5-(propylcarbamoyl)-1H-pyrrol-3-ylcarbamoyl)-1H-pyrrol-3-ylamino)-3-oxopropane-1-sulfonate (1), a peptide-based DNA minor groove binding methylating agent, were synthesized and characterized. In all cases, the N-terminus was appended with an O-methyl sulfonate ester, while the C-terminus group was varied with nonpolar and polar side chains. In addition, the number of pyrrole rings was varied from 2 (dipeptide) to 3 (tripeptide). The ability of the different analogues to efficiently generate N3-methyladenine was demonstrated as was their selectivity for minor groove (N3-methyladenine) versus major groove (N7-methylguanine) methylation. Induced circular dichroism studies were used to measure the DNA equilibrium binding properties of the stable sulfone analogues; the tripeptide binds with affinity that is >10-fold higher than that of the dipeptide. The toxicities of the compounds were evaluated in alkA/tag glycosylase mutant E. coli and in human WT glioma cells and in cells overexpressing and under-expressing N-methylpurine-DNA glycosylase, which excises N3-methyladenine from DNA. The results show that equilibrium binding correlates with the levels of N3-methyladenine produced and cellular toxicity. The toxicity of 1 was inversely related to the expression of MPG in both the bacterial and mammalian cell lines. The enhanced toxicity parallels the reduced activation of PARP and the diminished rate of formation of aldehyde reactive sites observed in the MPG knockdown cells. It is proposed that unrepaired N3-methyladenine is toxic due to its ability to directly block DNA polymerization.

  20. Correcting groove error in gratings ruled on a 500-mm ruling engine using interferometric control.

    Science.gov (United States)

    Mi, Xiaotao; Yu, Haili; Yu, Hongzhu; Zhang, Shanwen; Li, Xiaotian; Yao, Xuefeng; Qi, Xiangdong; Bayinhedhig; Wan, Qiuhua

    2017-07-20

    Groove error is one of the most important factors affecting grating quality and spectral performance. To reduce groove error, we propose a new ruling-tool carriage system based on aerostatic guideways. We design a new blank carriage system with double piezoelectric actuators. We also propose a completely closed-loop servo-control system with a new optical measurement system that can control the position of the diamond relative to the blank. To evaluate our proposed methods, we produced several gratings, including an echelle grating with 79  grooves/mm, a grating with 768  grooves/mm, and a high-density grating with 6000  grooves/mm. The results show that our methods effectively reduce groove error in ruled gratings.

  1. Sequence specificity and biological consequences of drugs that bind covalently in the minor groove of DNA

    International Nuclear Information System (INIS)

    Hurley, L.H.; Needham-VanDevanter, D.R.

    1986-01-01

    DNA ligands which bind within the minor groove of DNA exhibit varying degrees of sequence selectivity. Factors which contribute to nucleotide sequence recognition by minor groove ligands have been extensively investigated. Electrostatic interactions, ligand and DNA dehydration energies, hydrophobic interactions and steric factors all play significant roles in sequence selectivity in the minor groove. Interestingly, ligand recognition of nucleotide sequence in the minor groove does not involve significant hydrogen bonding. This is in sharp contrast to cellular enzyme and protein recognition of nucleotide sequence, which is achieved in the major groove via specific hydrogen bond formation between individual bases and the ligand. The ability to read nucleotide sequence via hydrogen bonding allows precise binding of proteins to specific DNA sequences. Minor groove ligands examined to date exhibit a much lower sequence specificity, generally binding to a subset of possible sequences, rather than a single sequence. 19 refs., 7 figs

  2. Coronary sinus and atrioventricular groove avulsion after motor vehicle crash

    Directory of Open Access Journals (Sweden)

    Bradley M Dennis

    2014-01-01

    Full Text Available Simultaneous cardiac and pericardial rupture from blunt chest trauma is a highly lethal combination with rarely reported survival. We report of a case of young patient with a right atrioventricular groove injury, pericardial rupture and a unique description of a coronary sinus avulsion following blunt chest trauma. Rapid recognition of this injury is crucial to patient survival, but traditional diagnostic adjuncts such as ultrasound, echocardiography and computed tomography are often unhelpful. Successful repair of these injuries requires high suspicion of injury, early cardiac surgery involvement of and possible even placement of the patient on cardiopulmonary bypass.

  3. Constitutional Syndrome, Ascites and Duodenal Thickening Presenting as Groove Pancreatitis

    Directory of Open Access Journals (Sweden)

    Jose Maria Frutos Perez

    2017-12-01

    Full Text Available Groove pancreatitis (GP is a very infrequent subtype of chronic pancreatitis affecting the pancreatic-duodenal junction. It usually manifests in middle-aged men with a history of chronic alcoholism, though it has also been described in women and in individuals who do not consume alcohol[1]. Even though the underlying etiology is unclear, chronic alcohol consumption is known to increase the viscosity of the pancreatic juice and exacerbate the inflammatory process[2]. We present a case of GP that posed diagnostic difficulties because it manifested as ascites and duodenal thickening, with pancreatic imaging findings initially normal.

  4. Narrow groove gas metal-arc welding of aluminum

    International Nuclear Information System (INIS)

    Armstrong, R.E.

    1975-01-01

    The Gas Metal-Arc (GMA) welding process is explained and the equipment used described with an analysis of power supply function and the action of the arc, followed by discussion of general applications and problems. GMA braze welding of beryllium is then described, as is the development of a special high purity filler wire and a narrow deep groove joint design for improved weld strength in beryllium. This joint design and the special wire are applied in making high strength welds in high strength aluminum for special applications. High speed motion pictures of the welding operation are shown to illustrate the talk. (auth)

  5. Microorganism Removal in Permeable Pavement Parking Lots ...

    Science.gov (United States)

    Three types of permeable pavements (pervious concrete, permeable interlocking concrete pavers, and porous asphalt) were monitored at the Edison Environmental Center in Edison, New Jersey for indicator organisms such as fecal coliform, enterococci, and E. coli. Results showed that porous asphalt had much lower concentration in monitored infiltrate compared to pervious concrete and permeable interlocking concrete pavers. Concentrations of monitored organisms in infiltrate from porous asphalt were consistently below the bathing water quality standard. Fecal coliform and enterococci exceeded bathing water quality standards more than 72% and 34% of the time for permeable interlocking concrete pavers and pervious concrete, respectively. Purpose is to evaluate the performance of permeable pavement in removing indicator organisms from infiltrating stormwater runoff.

  6. Combined endodontic-periodontic treatment of a palatal groove: a case report.

    Science.gov (United States)

    Schwartz, Scott A; Koch, Michael A; Deas, David E; Powell, Charles A

    2006-06-01

    The palatal groove is a developmental anomaly that predisposes the tooth involved to a severe periodontal defect. When further complicated by pulp necrosis, these grooves often present a diagnostic and treatment planning challenge that requires an interdisciplinary treatment approach. This case report describes the successful collaborative management of a maxillary lateral incisor with an extensive palatal groove using a combination of nonsurgical endodontic therapy, odontoplasty, and periodontal regenerative techniques.

  7. Pavement Management Systems on a Local Level

    OpenAIRE

    Vasquez, Cristian A.

    2011-01-01

    Roads are one of the most valuable infrastructure assets within a community. Proper maintenance of the roadway network can promote the prosperity of a community. In recent times maintenance has become much more difficult with the price of asphalt increasing drastically and city budgets contracting due to the economic downturn. With these conditions, the proper management of an agency’s street network is necessary. The use of pavement management systems provides the help needed in the preserva...

  8. Pavement cells and the topology puzzle.

    Science.gov (United States)

    Carter, Ross; Sánchez-Corrales, Yara E; Hartley, Matthew; Grieneisen, Verônica A; Marée, Athanasius F M

    2017-12-01

    D'Arcy Thompson emphasised the importance of surface tension as a potential driving force in establishing cell shape and topology within tissues. Leaf epidermal pavement cells grow into jigsaw-piece shapes, highly deviating from such classical forms. We investigate the topology of developing Arabidopsis leaves composed solely of pavement cells. Image analysis of around 50,000 cells reveals a clear and unique topological signature, deviating from previously studied epidermal tissues. This topological distribution is established early during leaf development, already before the typical pavement cell shapes emerge, with topological homeostasis maintained throughout growth and unaltered between division and maturation zones. Simulating graph models, we identify a heuristic cellular division rule that reproduces the observed topology. Our parsimonious model predicts how and when cells effectively place their division plane with respect to their neighbours. We verify the predicted dynamics through in vivo tracking of 800 mitotic events, and conclude that the distinct topology is not a direct consequence of the jigsaw piece-like shape of the cells, but rather owes itself to a strongly life history-driven process, with limited impact from cell-surface mechanics. © 2017. Published by The Company of Biologists Ltd.

  9. Management of endodontic-periodontic lesion of a maxillary lateral incisor with palatoradicular groove

    Directory of Open Access Journals (Sweden)

    Jayshree Ramakrishna Vishwas

    2014-01-01

    Full Text Available Presence of palatal radicular grooves are considered to be an important contributing factor to the development of localized periodontitis, as it favored the accumulation and proliferation of bacterial plaque deep into the periodontium. Pulp involvement could result due to the introduction of bacterial toxins through channels that existed between the root canal system and the groove. Early diagnosis, elimination of inflammation and correction of anatomic complications are the key to a favorable outcome for managing palatoradicular groove. Present report describes successful management with an interdisciplinary approach of maxillary lateral incisor with combined endodontic periodontic lesion associated with palatoradicular groove.

  10. Enhanced heat transfer performances of molten salt receiver with spirally grooved pipe

    International Nuclear Information System (INIS)

    Lu, Jianfeng; Ding, Jing; Yu, Tao; Shen, Xiangyang

    2015-01-01

    The enhanced heat transfer performances of solar receiver with spirally grooved pipe were theoretically investigated. The physical model of heat absorption process was proposed using the general heat transfer correlation of molten salt in smooth and spirally grooved pipe. According to the calculation results, the convective heat transfer inside the receiver can remarkably enhance the heat absorption process, and the absorption efficiency increased with the flow velocity and groove height, while the wall temperature dropped. As the groove height increased, the heat losses of convection and radiation dropped with the decrease of wall temperature, and the average absorption efficiency of the heat receiver can be increased. Compared with the heat receiver with smooth pipe, the heat absorption efficiency of heat receiver with spirally grooved pipe e/d = 0.0475 can rise for 0.7%, and the maximum bulk fluid temperature can be increased for 31.1 °C. As a conclusion, spirally grooved pipe can be a very effective way for heat absorption enhancement of solar receiver, and it can also increase the operating temperature of molten salt. - Highlights: • Spirally grooved tube is a very effective way for solar receiver enhancement. • Heat absorption model of receiver is proposed with general heat transfer correlation. • Spirally groove tube increases absorption efficiency and reduces wall temperature. • Operating temperature of molten salt remarkably increases with groove height. • Heat absorption performance is promoted for first and second thermodynamics laws

  11. Space qualification of high capacity grooved heat pipes

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, M; Mullender, B; Druart, J [SABCA, Societe Anomyme Belgel de Construction Aeronautique (Belgium); Supper, W; Beddows, A [ESTEC-The (Netherlands)

    1997-12-31

    Based on the thermal requirements of the future telecommunication satellites, the development of a High Capacity Grooved Heat Pipe (HPG), was contracted by ESA to SABCA leading to an aluminium extruded heat pipe (outer diameter of 25 mm) based on a multi re-entrant grooves design. After an intensive acceptance test campaign whose results showed a good confidence in the design and the fulfillment of the required specifications of heat transport and on tilt capability (experimental maximum heat transport capability of 1500 Watt metres for a vapour temperature of 20 deg C), similar heat pipes have been developed with various outer diameters (11 mm, 15 mm and 20 mm) and with various shapes (circular outer shapes, integrated saddles). Several of these heat pipes were tested during two parabolic flight campaigns, by varying the heat loads during the micro-gravity periods. This HGP heat pipe family is now being submitted to a space qualification program according to ESA standards (ESA PSS-49), both in straight and bent configuration. Within this qualification, the heat pipes are submitted to an extended test campaign including environmental (random/sinus vibration, constant acceleration) and thermal tests (thermal performance, thermal cycle, thermal soak, ageing). (authors) 9 refs.

  12. Syncopation affects free body-movement in musical groove

    DEFF Research Database (Denmark)

    Witek, Maria A. G.; Popescu, Tudor; Clarke, Eric F

    2016-01-01

    One of the most immediate and overt ways in which people respond to music is by moving their bodies to the beat. However, the extent to which the rhythmic complexity of groove-specifically its syncopation-contributes to how people spontaneously move to music is largely unexplored. Here, we measur...... on the body-part. We demonstrate that while people do not move or synchronise much to rhythms with high syncopation when dancing spontaneously to music, the relationship between rhythmic complexity and synchronisation is less linear than in simple finger-tapping studies.......One of the most immediate and overt ways in which people respond to music is by moving their bodies to the beat. However, the extent to which the rhythmic complexity of groove-specifically its syncopation-contributes to how people spontaneously move to music is largely unexplored. Here, we measured...... free movements in hand and torso while participants listened to drum-breaks with various degrees of syncopation. We found that drum-breaks with medium degrees of syncopation were associated with the same amount of acceleration and synchronisation as low degrees of syncopation. Participants who enjoyed...

  13. Capillary contact angle in a completely wet groove.

    Science.gov (United States)

    Parry, A O; Malijevský, A; Rascón, C

    2014-10-03

    We consider the phase equilibria of a fluid confined in a deep capillary groove of width L with identical side walls and a bottom made of a different material. All walls are completely wet by the liquid. Using density functional theory and interfacial models, we show that the meniscus separating liquid and gas phases at two phase capillary coexistence meets the bottom capped end of the groove at a capillary contact angle θ(cap)(L) which depends on the difference between the Hamaker constants. If the bottom wall has a weaker wall-fluid attraction than the side walls, then θ(cap) > 0 even though all the isolated walls are themselves completely wet. This alters the capillary condensation transition which is now first order; this would be continuous in a capped capillary made wholly of either type of material. We show that the capillary contact angle θ(cap)(L) vanishes in two limits, corresponding to different capillary wetting transitions. These occur as the width (i) becomes macroscopically large, and (ii) is reduced to a microscopic value determined by the difference in Hamaker constants. This second wetting transition is characterized by large scale fluctuations and essential critical singularities arising from marginal interfacial interactions.

  14. Flight trajectory of a rotating golf ball with grooves

    Science.gov (United States)

    Baek, Moonheum; Kim, Jooha; Choi, Haecheon

    2014-11-01

    Dimples are known to reduce drag on a sphere by the amount of 50% as compared to a smooth surface. Despite the advantage of reducing drag, dimples deteriorate the putting accuracy owing to their sharp edges. To minimize this putting error but maintain the same flight distance, we have devised a grooved golf ball (called G ball hereafter) for several years. In this study, we modify the shape and pattern of grooves, and investigate the flow characteristics of the G ball by performing wind-tunnel experiments at the Reynolds numbers of 0 . 5 ×105 - 2 . 5 ×105 and the spin ratios (ratio of surface velocity to the free-stream velocity) of 0 - 0.6 that include the real golf-ball velocity and rotational speed. We measure the drag and lift forces on the rotating G ball and compare them with those of a smooth ball and two well-known dimpled balls. The lift-to-drag ratio of the G ball is much higher than that of a smooth ball and is in between those of the two dimpled balls. The trajectories of flying golf balls are computed. The flight distance of G ball is almost the same as that of one dimpled ball but slightly shorter than that of the other dimpled ball. The fluid-dynamic aspects of these differences will be discussed at the talk. Supported by 2011-0028032, 2014M3C1B1033980.

  15. Space qualification of high capacity grooved heat pipes

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, M.; Mullender, B.; Druart, J. [SABCA, Societe Anomyme Belgel de Construction Aeronautique (Belgium); Supper, W.; Beddows, A. [ESTEC-The (Netherlands)

    1996-12-31

    Based on the thermal requirements of the future telecommunication satellites, the development of a High Capacity Grooved Heat Pipe (HPG), was contracted by ESA to SABCA leading to an aluminium extruded heat pipe (outer diameter of 25 mm) based on a multi re-entrant grooves design. After an intensive acceptance test campaign whose results showed a good confidence in the design and the fulfillment of the required specifications of heat transport and on tilt capability (experimental maximum heat transport capability of 1500 Watt metres for a vapour temperature of 20 deg C), similar heat pipes have been developed with various outer diameters (11 mm, 15 mm and 20 mm) and with various shapes (circular outer shapes, integrated saddles). Several of these heat pipes were tested during two parabolic flight campaigns, by varying the heat loads during the micro-gravity periods. This HGP heat pipe family is now being submitted to a space qualification program according to ESA standards (ESA PSS-49), both in straight and bent configuration. Within this qualification, the heat pipes are submitted to an extended test campaign including environmental (random/sinus vibration, constant acceleration) and thermal tests (thermal performance, thermal cycle, thermal soak, ageing). (authors) 9 refs.

  16. Reassessing the Function of Grooves in Mycenaean Tombs

    Directory of Open Access Journals (Sweden)

    Constantina Katsari

    2001-11-01

    Full Text Available Normal 0 0 2 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Among the Chamber and Tholos Tombs that were built in Greece during the Late Helladic period are some that show a particular feature: a pair of grooves that are carved on the floor of the 'stomion '(a short corridor that leads inside the tomb, leading from the 'dromos '(a long road that leads towards the tomb itself into the chamber. Archaeologists have suggested a number of explanations regarding their function; however, none of these seems entirely plausible. In this article, we offer a different kind of hypothesis mostly based on architectural evidence. We will suggest that, rather than being related to ritual practices, the grooves were mainly used to facilitate the construction of the graves.

  17. An analysis of pavement heat flux to optimize the water efficiency of a pavement-watering method

    International Nuclear Information System (INIS)

    Hendel, Martin; Colombert, Morgane; Diab, Youssef; Royon, Laurent

    2015-01-01

    Pavement-watering as a technique of cooling dense urban areas and reducing the urban heat island effect has been studied since the 1990's. The method is currently considered as a potential tool for and climate change adaptation against increasing heat wave intensity and frequency. However, although water consumption necessary to implement this technique is an important aspect for decision makers, optimization of possible watering methods has only rarely been conducted. An analysis of pavement heat flux at a depth of 5 cm and solar irradiance measurements is proposed to attempt to optimize the watering period, cycle frequency and water consumption rate of a pavement-watering method applied in Paris over the summer of 2013. While fine-tuning of the frequency can be conducted on the basis of pavement heat flux observations, the watering rate requires a heat transfer analysis based on a relation established between pavement heat flux and solar irradiance during pavement insolation. From this, it was found that watering conducted during pavement insolation could be optimized to 30-min cycles and water consumption could be reduced by more than 80% while reducing the cooling effect by less than 13%. - Highlights: • The thermal effects of pavement-watering were investigated in Paris, France. • Pavement-watering was found to significantly affect pavement heat flux 5 cm deep. • When insolated, a linear relation was found between heat flux and solar radiation. • Pavement-watering did not alter its slope, but introduced a negative intercept. • Subsequent improvements of the watering period, frequency and rate are proposed

  18. Modeling the Hydrologic Processes of a Permeable Pavement System

    Science.gov (United States)

    A permeable pavement system can capture stormwater to reduce runoff volume and flow rate, improve onsite groundwater recharge, and enhance pollutant controls within the site. A new unit process model for evaluating the hydrologic performance of a permeable pavement system has be...

  19. Permeable Pavement Research at the Edison Environmental Center

    Science.gov (United States)

    There are few detailed studies of full-scale, replicated, actively-used permeable pavement systems. Practitioners need additional studies of permeable pavement systems in its intended application (parking lot, roadway, etc.) across a range of climatic events, daily usage conditio...

  20. Nutrient Infiltrate Concentrations from Three Permeable Pavement Types

    Science.gov (United States)

    While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types have on nutrient concentrations present in stormwater runoff are limited. In 2009, the U.S. EPA constructed a 0.4-ha...

  1. Full scale demonstration of air-purifying pavement

    NARCIS (Netherlands)

    Ballari, M.; Brouwers, H.J.H.

    2013-01-01

    Experiments concerning a full-scale demonstration of air purifying pavement in Hengelo, The Netherlands, are reported. The full width of the street was provided with concrete pavement containing TiO2 over a length of 150 m ("DeNOx street"). Another part of the street, about 100 m, was paved with

  2. Effects of street tree shade on asphalt concrete pavement performance

    Science.gov (United States)

    E.G. McPherson; J. Muchnick

    2005-01-01

    Forty-eight street segments were paired into 24 high-and low-shade pairs in Modesto, California, U.S. Field data were collected to calculate a Pavement Condition Index (PCI) and Tree Shade Index (TSI) for each segment. Statistical analyses found that greater PCI was associated with greater TSI, indicating that tree shade was partially responsible for reduced pavement...

  3. 3D Tyre/Road pavement contact stress measurements

    CSIR Research Space (South Africa)

    De Beer, Morris

    2010-10-01

    Full Text Available The CSIR’s proprietary Stress-in-Motion (SIM) measurements provide rational descriptions of 1D, 2D and 3D tyre/road pavement stresses for: Road pavement design testing and evaluation, as well as tyre design, testing and evaluation....

  4. Soil Properties And Pavement Performance In The Nigerian ...

    African Journals Online (AJOL)

    The geotechnical properties of the sub-structure of the Shagamu-Ore-Benin pavement were studied in an attempt to identifying the quality of construction materials and the pavement performance. The sub-structure soil materials were collected from the field and were taken to the laboratory for particle size analysis, Atterberg ...

  5. Accelerated load testing of geosynthetic base reinforced pavement test sections.

    Science.gov (United States)

    2011-02-01

    The main objective of this research is to evaluate the benefits of geosynthetic stabilization and reinforcement of subgrade/base aggregate layers in flexible pavements built on weak subgrades and the effect of pre-rut pavement sections, prior to the ...

  6. Effect of training algorithms on neural networks aided pavement ...

    African Journals Online (AJOL)

    Especially, the use of Finite Element (FE) based pavement modeling results for training the NN aided inverse analysis is considered to be accurate in realistically characterizing the non-linear stress-sensitive response of underlying pavement layers in real-time. Efficient NN learning algorithms have been developed and ...

  7. Long-term Metal Performance of Three Permeable Pavements

    Science.gov (United States)

    EPA constructed a 4,000-m2 parking lot surfaced with three permeable pavements (permeable interlocking concrete pavers, pervious concrete, and porous asphalt) on the Edison Environmental Center in Edison, NJ in 2009. Samples from each permeable pavement infiltrate were collected...

  8. Assessing Asphalt and Concrete Pavement Surface Texture in the Field

    Directory of Open Access Journals (Sweden)

    Saad I. Sarsam

    2016-06-01

    Full Text Available The incorporation of safety characteristics into the traditional pavement structural design or in the functional evaluation of pavement condition has not been established yet. The design has focused on the structural capacity of the roadway so that the pavement can withstand specific level of repetitive loading over the design life. On the other hand, the surface texture condition was neither included in the AASHTO design procedure nor in the present serviceability index measurements. The pavement surface course should provide adequate levels of friction and ride quality and maintain low levels of noise and roughness. Many transportation departments perform routine skid resistant testing, the type of equipment used for testing varies depending on the preference of each transportation department. It was felt that modeling of the surface texture condition using different methods of testing may assist in solving such problem. In this work, Macro texture and Micro texture of asphalt and cement concrete pavement surface have been investigated in the field using four different methods (The Sand Patch Method, Outflow Time Method, British Pendulum Tester and Photogrammetry Technique. Two different grain sizes of sand have been utilized in conducting the Sand Patch while the Micro texture was investigated using the British Pendulum tester method at wet pavement surface conditions. The test results of the four methods were correlated to the skid number. It was concluded that such modeling could provide instant data in the field for pavement condition which may help in pavement maintenance management.

  9. Highway pavement failure induced by poor soil geotechnical ...

    African Journals Online (AJOL)

    X-ray diffraction studies showed the presence of abundant kaolinite peaks and a subdued goethite peak without any trace of montmorrilonite. The presence of excess fines in the pavement construction materials (soils) contributed to the failure of the highway pavement at this locality. The low CBR value is also a noted cause ...

  10. 23 CFR 973.208 - Indian lands pavement management system (PMS).

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Indian lands pavement management system (PMS). 973.208... PROGRAM Bureau of Indian Affairs Management Systems § 973.208 Indian lands pavement management system (PMS... concepts described in the AASHTO's “Pavement Management Guide.” 1 1 “Pavement Management Guide,” AASHTO...

  11. Influence of Pavement on Fatigue Performance of Urban Steel Box Girder Deck

    Directory of Open Access Journals (Sweden)

    Zheng Zhongyue

    2016-01-01

    Full Text Available Based on spatial finite element analysis method, the Influence of pavement on fatigue performance of orthotropic steel deck was analyzed in terms of pavement system, asphalt pavement stiffness. The result shows that compared with asphalt pavement system, RPC pavement system can not only obviously improve the stress condition of steel bridge deck, but also significantly extend the fatigue life of steel bridge panel; Increasing the stiffness of pavement layer can obviously reduce the stress amplitude of fatigue details, especially for direct contact with the pavement.

  12. The Simulation Realization of Pavement Roughness in the Time Domain

    Science.gov (United States)

    XU, H. L.; He, L.; An, D.

    2017-10-01

    As the needs for the dynamic study on the vehicle-pavement system and the simulated vibration table test, how to simulate the pavement roughness actually is important guarantee for whether calculation and test can reflect the actual situation or not. Using the power spectral density function, the simulation of pavement roughness can be realized by Fourier inverse transform. The main idea of this method was that the spectrum amplitude and random phase were obtained separately according to the power spectrum, and then the simulation of pavement roughness was obtained in the time domain through the Fourier inverse transform (IFFT). In the process, the sampling interval (Δl) was 0.1m, and the sampling points(N) was 4096, which satisfied the accuracy requirements. Using this method, the simulate results of pavement roughness (A~H grades) were obtain in the time domain.

  13. Importance of dowels in transversal joints in concrete pavements

    Science.gov (United States)

    Grosek, Jiri; Chupik, Vladimir; Stryk, Josef; Brezina, Ilja

    2017-09-01

    Concrete pavements are designed for heavy loaded road structures. Their usage brings a number of specific issues. It is necessary to solve them all to ensure that concrete pavements will fulfil their function along the whole design period. One of these issues concerns dowels, which are located in transversal joints. Modelling of load, caused by heavy vehicles, with the use of the finite element method, provides valuable information about the stress condition of concrete pavement. The results of modelling can be verified by measurements or experiments in practice. Dowels and tie bars in jointed unreinforced concrete pavements and the importance of their correct placement, dimensions and material quality on pavement behaviour and lifespan were studied as a part of R&D projects of Technology Agency of the Czech Republic Nos. TA02031195 and TE01020168. The paper presents the experience from the modelling and performed experiments and makes conclusions which are important for the use in practice.

  14. Utilization of Advanced Diagnostic Methods for Texture and Rut Depth Analysis on a Testing Pavement Section

    Directory of Open Access Journals (Sweden)

    Slabej Martin

    2015-05-01

    Full Text Available Qualitative characteristics of pavement in wide range reflects the pavement serviceability, which is a summary of the characteristics of the pavement, providing a fast, smooth, economical and especially safe driving of motor-vehicles. The target factor of pavement serviceability and safety of roads represents the quality of their surface properties. In the framework of research activities performed in the Research Centre founded under the auspices of University of Žilina, individual parameters of pavement serviceability were monitored by pavement surface scanning. This paper describes the creation of a 3D - road surface model and its analysis and evaluation from the viewpoint of two pavement serviceability parameters - the rut depth and texture. Measurements were performed on an experimental pavement section used contemporary in an Accelerated Pavement Testing experiment. The long-term goal is to ascertain functions predicting degradation of these two pavement serviceability parameters.

  15. Photocatalytic pavement blocks. Air purification by pavement blocks. Final results of the research at BRRC

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    The use of materials can influence to a large extent the environmental impact of traffic and of road infrastructure. Especially in urban areas, where the risk on smog formation during hot summer days is high, the use of photocatalytic pavement blocks can reduce the air pollution significantly. A project on environmental friendly concrete pavement blocks is conducted at the Belgian Road Research Centre. The use of photocatalytic material in the surface of pavement blocks to obtain air purifying materials is investigated. In contact with light, TiO2 as photocatalyst, is able to reduce the NO and NO2 content in the air, caused by the exhaust of traffic. The efficiency is tested on pavement blocks, but the technique can as well be applied on other road elements (e.g. noise reducing walls, linear elements) or as a coating on new materials or existing structures. At the previous TRA conference in Gotenborgh, Sweden, the principle of photocatalysis was presented. In this paper, emphasis will be put on the final results of the 4-year project obtained in laboratory as well as on site at the Leien of Antwerp (10,000 m{sup 2}). The results indicate a durable efficiency towards NOx reduction, which is in favour for the diminishing of the risk on ozone formation. However, the precise translation from the laboratory towards the site is still in question. The results obtained during the project are discussed in this paper.

  16. Photocatalytic pavement blocks. Air purification by pavement blocks. Final results of the research at BRRC

    International Nuclear Information System (INIS)

    2009-01-01

    The use of materials can influence to a large extent the environmental impact of traffic and of road infrastructure. Especially in urban areas, where the risk on smog formation during hot summer days is high, the use of photocatalytic pavement blocks can reduce the air pollution significantly. A project on environmental friendly concrete pavement blocks is conducted at the Belgian Road Research Centre. The use of photocatalytic material in the surface of pavement blocks to obtain air purifying materials is investigated. In contact with light, TiO2 as photocatalyst, is able to reduce the NO and NO2 content in the air, caused by the exhaust of traffic. The efficiency is tested on pavement blocks, but the technique can as well be applied on other road elements (e.g. noise reducing walls, linear elements) or as a coating on new materials or existing structures. At the previous TRA conference in Gotenborgh, Sweden, the principle of photocatalysis was presented. In this paper, emphasis will be put on the final results of the 4-year project obtained in laboratory as well as on site at the Leien of Antwerp (10,000 m 2 ). The results indicate a durable efficiency towards NOx reduction, which is in favour for the diminishing of the risk on ozone formation. However, the precise translation from the laboratory towards the site is still in question. The results obtained during the project are discussed in this paper

  17. Performance of continuously reinforced concrete pavements volume 5 : maintenance and repair of CRC pavements.

    Science.gov (United States)

    1998-10-01

    This report is one of a series of reports prepared as part of a recent study sponsored by the Federal Highway Administration (FHWA) aimed at updating the state-of-the-art of the design, construction, maintenance, and rehabiilitation of CRC pavements....

  18. Towards Understanding Tyre-Pavement Contact in APT Research on Flexible Pavements

    CSIR Research Space (South Africa)

    De Beer, Morris

    2016-09-01

    Full Text Available An important element of Accelerated Pavement Testing (APT) is the selection of appropriate test tyre(s) to be used for APT testing. By far the majority of full scale (or scaled) APT devices uses pneumatic rubber tyres. Tyres differ not only in size...

  19. Pavement noise research : modeling of quieter pavements in Florida, final report, October 19, 2009.

    Science.gov (United States)

    2009-10-01

    The research on noise created by the tire/pavement interface, while relatively new, has seen considerable interest over the past few years because of the potential benefits and a general desire by the public for quieter highways. The Florida Departme...

  20. Pavement Pre- and Post-Treatment Performance Models Using LTPP Data

    OpenAIRE

    Lu, Pan; Tolliver, Denver

    2012-01-01

    This paper determines that pavement performance in International Roughness Index (IRI) is affected by exogenous interventions such as pavement age, precipitation level, freeze-thaw level, and lower level preservation maintenance strategies. An exponential function of pavement age was used to represent pavement IRI performance curves. Moreover, this paper demonstrates a method which calculates short-term post-pavement performance models from maintenance effect models and pre-treatment performa...

  1. Pavement structure mechanics response of flexible on semi-flexible overlay that based on the old cement concrete pavement damage

    Directory of Open Access Journals (Sweden)

    Jiang Ruinan

    2015-01-01

    Full Text Available The old cement pavement damage status directly affect the design of the paving renovation. Based on the state of the old road investigation, combined with the research data at home and abroad, use the control index that average deflection, deflection value and CBR value to determine the reasonable time to overlay. Draw up the typical pavement structure according to the principle of combination of old cement pavement overlay structure design, and calculated that the tensile stress and shear stress in asphalt layer ,semi-flexible layer and the tensile in the old cement pavement adopting BISA3.0 statics finite element analysis model when modulus in the old road was diminishing. Use the computed result to analyses the influence of old road damage condition the influence of pavement structure.

  2. Treatment of combined endodontic: periodontic lesion by sealing of palato-radicular groove using biodentine

    OpenAIRE

    Naik, Mayuri; de Ataide, Ida de Noronha; Fernandes, Marina; Lambor, Rajan

    2014-01-01

    Introduction: Palatoradicular groove is a developmental anomaly which is predominantly found in maxillary lateral incisors. It provides a susceptible alcove for the progression of localised periodontal inflammation which can further cause pulpal involvement. This case report describes the successful treatment of a large periodontic - endodontic lesion usingnon surgical endodontic therapy and biodentine for the sealing of the palatoradicular groove.

  3. Treatment of combined endodontic: periodontic lesion by sealing of palato-radicular groove using biodentine.

    Science.gov (United States)

    Naik, Mayuri; de Ataide, Ida de Noronha; Fernandes, Marina; Lambor, Rajan

    2014-11-01

    Palatoradicular groove is a developmental anomaly which is predominantly found in maxillary lateral incisors. It provides a susceptible alcove for the progression of localised periodontal inflammation which can further cause pulpal involvement. This case report describes the successful treatment of a large periodontic - endodontic lesion usingnon surgical endodontic therapy and biodentine for the sealing of the palatoradicular groove.

  4. Grooved floor system for cattle housing: ammonia emission reduction and good slip resistance

    NARCIS (Netherlands)

    Swierstra, D.; Braam, C.R.; Smits, M.C.J.

    2001-01-01

    To improve the slip resistance of solid floors in dairy cow houses and to achieve the ammonia emission reduction prescribed by the Dutch government, precast concrete floors with grooves and a dung scraper were investigated. The grooves parallel to the alley had 160 mm center-to-center spacing and

  5. Side-coupled cavity model for surface plasmon-polariton transmission across a groove

    International Nuclear Information System (INIS)

    Liu, J.S.Q.

    2010-01-01

    We demonstrate that the transmission properties of surface plasmon-polaritons (SPPs) across a rectangular groove in a metallic film can be described by an analytical model that treats the groove as a side-coupled cavity to propagating SPPs on the metal surface. The coupling efficiency to the groove is quantified by treating it as a truncated metal-dielectric-metal (MDM) waveguide. Finite-difference frequency-domain (FDFD) simulations and mode orthogonality relations are employed to derive the basic scattering coefficients that describe the interaction between the relevant modes in the system. The modeled SPP transmission and reflection intensities show excellent agreement with full-field simulations over a wide range of groove dimensions, validating this intuitive model. The model predicts the sharp transmission minima that occur whenever an incident SPP resonantly couples to the groove. We also for the first time show the importance of evanescent, reactive MDM SPP modes to the transmission behavior. SPPs that couple to this mode are resonantly enhanced upon reflection from the bottom of the groove, leading to high field intensities and sharp transmission minima across the groove. The resonant behavior exhibited by the grooves has a number of important device applications, including SPP mirrors, filters, and modulators.

  6. Solving the N-Queens Problem with GROOVE - Towards a Compendium of Best Practices

    NARCIS (Netherlands)

    Zambon, Eduardo; Rensink, Arend; Hermann, F.; Sauer, S.

    We present a detailed solution to the N-queens puzzle using GROOVE, a graph transformation tool especially designed for state space exploration and analysis. While GROOVE has been freely available for more than a decade and has attracted a reasonable number of users, it is safe to say that only a

  7. Hybrid plasmonic waveguide in a metal V-groove

    Directory of Open Access Journals (Sweden)

    Zhao-xian Chen

    2014-01-01

    Full Text Available We propose and investigate a type of hybrid plasmonic waveguide in a metal V-groove. A high-permittivity nanowire was placed in the metal channel covered with a dielectric film of lower permittivity. Deeper sub-wavelength confinement and much longer propagation distance were achieved in comparison with conventional channel plasmonic waveguides. The overall performance was improved as compared with the conventional hybrid plasmonic structure based on a flat metal surface. Finite element analysis showed that both the mode propagation and field profile can be adjusted by changing the nanowire radius and film thickness. Some benefits, such as a reduced scattering loss caused by the surface roughness, are also expected owing to the unique mode profile. The proposed approach has potential for application in high-level photonic integration.

  8. From old alkylating agents to new minor groove binders.

    Science.gov (United States)

    Puyo, Stéphane; Montaudon, Danièle; Pourquier, Philippe

    2014-01-01

    Alkylating agents represent the oldest class of anticancer agents with the approval of mechloretamine by the FDA in 1949. Even though their clinical use is far beyond the use of new targeted therapies, they still occupy a major place in the treatment of specific malignancies, sometimes representing the unique option for the treatment of refractory tumors. Here, we are reviewing the major classes of alkylating agents, with a particular focus on the latest generations of compounds that specifically target the minor groove of the DNA. These naturally occurring derivatives have a unique mechanism of action that explains the recent regain of interest in developing new classes of alkylating agents that could be used in combination with other anticancer drugs to enhance tumor response in the clinic. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. Identification of Pavement Distress Types and Pavement Condition Evaluation Based on Network Level Inspection for Jazan City Road Network

    Directory of Open Access Journals (Sweden)

    M Mubaraki

    2014-06-01

    Full Text Available The first step in establishing a pavement management system (PMS is road network identification. An important feature of a PMS is the ability to determine the current condition of a road network and predict its future condition. Pavement condition evaluation may involve structure, roughness, surface distress, and safety evaluation. In this study, a pavement distress condition rating procedure was used to achieve the objectives of this study. The main objectives of this study were to identify the common types of distress that exist on the Jazan road network (JRN, either on main roads or secondary roads, and to evaluate the pavement condition based on network level inspection. The study was conducted by collecting pavement distress types from 227 sample units on main roads and 500 sample units from secondary roads. Data were examined through analysis of common types of distress identified in both main and secondary roads. Through these data, pavement condition index (PCI for each sample unit was then calculated. Through these calculations, average PCIs for the main and secondary roads were determined. Results indicated that the most common pavement distress types on main roads were patching and utility cut patching, longitudinal and transverse cracking, polished aggregate, weathering and raveling, and alligator cracking. The most common pavement distress types on secondary roads were weathering and raveling, patching and utility cut patching, longitudinal and transverse cracking, potholes, and alligator cracking. The results also indicated that 65% of Jazan's main road network has an average pavement condition rating of very good while only 30% of Jazan's secondary roads network has an average pavement condition.

  10. Influence of edge conditions on material ejection from periodic grooves in laser shock-loaded tin

    Energy Technology Data Exchange (ETDEWEB)

    Rességuier, T. de; Roland, C. [Institut PPRIME, UPR 3346, CNRS, ENSMA, Université de Poitiers, 1 ave. Clément Ader, 86961 Futuroscope Cedex (France); Prudhomme, G.; Lescoute, E.; Mercier, P. [CEA, DAM, DIF, 91297 Arpajon (France); Loison, D. [Institut de Physique de Rennes, CNRS, Université de Rennes 1, 35042 Rennes (France)

    2016-05-14

    In a material subjected to high dynamic compression, the breakout of a shock wave at a rough free surface can lead to the ejection of high velocity debris. Anticipating the ballistic properties of such debris is a key safety issue in many applications involving shock loading, including pyrotechnics and inertial confinement fusion experiments. In this paper, we use laser driven shocks to investigate particle ejection from calibrated grooves of micrometric dimensions and approximately sinusoidal profile in tin samples, with various boundary conditions at the groove edges, including single groove and periodic patterns. Fast transverse shadowgraphy provides ejection velocities after shock breakout. They are found to depend not only on the groove depth and wavelength, as predicted theoretically and already observed in the past, but also, unexpectedly, on the edge conditions, with a jet tip velocity significantly lower in the case of a single groove than behind a periodic pattern.

  11. Dispersion characteristics of planar grating with arbitrary grooves for terahertz Smith-Purcell radiation

    International Nuclear Information System (INIS)

    Cao, Miaomiao; Li, Ke; Liu, Wenxin; Wang, Yong

    2015-01-01

    In this paper, a novel method of getting the dispersion relations in planar grating with arbitrary grooves for terahertz Smith-Purcell radiation is investigated analytically. The continuous profile of the groove is approximately replaced by a series of rectangular steps. By making use of field matches method and the continuity of transverse admittance, the universal dispersion equation for grating with arbitrarily shaped grooves is derived. By solving the dispersion equation in presence of electron beam, the growth rate is obtained directly and the dependence on beam parameters is analyzed. Comparisons of the dispersion characteristics among some special groove shapes have been made by numerical calculation. The results show that the rectangular-step approximation method provides a novel approach to obtain the universal dispersion relation for grating with arbitrary grooves for Smith-Purcell radiation

  12. Treatment of a Developmental Groove and Supernumerary Root Using Guided Tissue Regeneration Technique

    Directory of Open Access Journals (Sweden)

    Zahra Alizadeh Tabari

    2016-01-01

    Full Text Available Introduction. The radicular groove is a developmental groove which is usually found on the palatal or lateral aspects of the maxillary incisor teeth. The present case is a maxillary lateral incisor with a small second root and a deep radicular groove. The developmental groove caused a combined periodontal-endodontic lesion. Methods. Case was managed using a combined treatment procedure involving nonsurgical root canal therapy and surgical periodontal treatment. After completion of root canal treatment, guided tissue regeneration (GTR was carried out using decalcified freeze dried bone allograft (DFDBA and a bioabsorbable collagenous membrane. Tooth also was splinted for two months. Results. After 12 months the tooth was asymptomatic. The periapical radiolucency disappeared and probing depth did not exceed 3 mm. Conclusion. Combined treatment procedure involving nonsurgical root canal therapy and surgical periodontal regenerative treatment can be a predictable technique in treating combined endodontic-periodontal lesions caused by radicular groove.

  13. Fatigue Behavior of Modified Asphalt Concrete Pavement

    Directory of Open Access Journals (Sweden)

    saad I. Sarsam

    2016-02-01

    Full Text Available Fatigue cracking is the most common distress in road pavement. It is mainly due to the increase in the number of load repetition of vehicles, particularly those with high axle loads, and to the environmental conditions. In this study, four-point bending beam fatigue testing has been used for control and modified mixture under various micro strain levels of (250 μƐ, 400 μƐ, and 750 μƐ and 5HZ. The main objective of the study is to provide a comparative evaluation of pavement resistance to the phenomenon of fatigue cracking between modified asphalt concrete and conventional asphalt concrete mixes (under the influence of three percentage of Silica fumes 1%, 2%, 3% by the weight of asphalt content, and (changing in the percentage of asphalt content by (0.5% ± from the optimum. The results show that when Silica fumes content was 1%, the fatigue life increases by 17%, and it increases by 46% when Silica fumes content increases to 2%, and that fatigue life increases to 34 % when Silica fumes content increases to 3% as compared with control mixture at (250 μƐ, 20°C and optimum asphalt content. From the results above, we can conclude the optimum Silica fumes content was 2%. When the asphalt content was 4.4%, the fatigue life has increased with the use of silica fumes by (50%, when asphalt content was 5.4%, the additives had led to increasing the fatigue life by (69%, as compared with the conventional asphalt concrete pavement.

  14. Individual differences in beat perception affect gait responses to low- and high-groove music.

    Directory of Open Access Journals (Sweden)

    Li-Ann eLeow

    2014-10-01

    Full Text Available Slowed gait in Parkinson’s disease (PD patients can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the beat, which might be difficult for PD patients who tend to show weak beat perception. One solution may be to use high groove music, which has high beat salience that may facilitate synchronization, and affective properties which may improve motivation to move. As a first step in understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low groove music, high groove music, and metronome cues. High groove music was predicted to elicit better synchronization than low groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1 preferred tempo: beat rate matched to preferred step rate and (2 faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high groove music, and worst with low groove music. In addition, high groove music elicited longer and faster steps than low groove music, both at preferred tempo and at faster tempo. Low groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation.

  15. Individual Differences in Beat Perception Affect Gait Responses to Low- and High-Groove Music

    Science.gov (United States)

    Leow, Li-Ann; Parrott, Taylor; Grahn, Jessica A.

    2014-01-01

    Slowed gait in patients with Parkinson’s disease (PD) can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the “beat,” which might be difficult for patients with PD who tend to show weak beat perception. One solution may be to use high-groove music, which has high beat salience that may facilitate synchronization, and affective properties, which may improve motivation to move. As a first step to understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low-groove music, high-groove music, and metronome cues. High-groove music was predicted to elicit better synchronization than low-groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1) preferred tempo: beat rate matched to preferred step rate and (2) faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high-groove music, and worst with low-groove music. In addition, high-groove music elicited longer and faster steps than low-groove music, both at preferred tempo and at faster tempo. Low-groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation. PMID:25374521

  16. Effects of groove shape of notch on the flow characteristics of spool valve

    International Nuclear Information System (INIS)

    Ye, Yi; Yin, Chen-Bo; Li, Xing-Dong; Zhou, Wei-jin; Yuan, Feng-feng

    2014-01-01

    Highlights: • Flow characteristics of notches are studied using CFD simulation and experiment. • Test data is fitted by least square method to analyze discharge coefficient. • The stable value of discharge coefficient is deduced. • Effects of groove shape on steady flow force and throttling stiffness are performed. • The groove shape has significant effects on the flow characteristics. - Abstract: The grooves of notches of hydraulic spool valves are usually designed into various shapes for their desired flow characteristics. The aim of this paper is to clarify the effects of the groove shape on the flow characteristics through computational fluid dynamics (CFD) and experimental investigations. The RNG k–ε turbulence model is used to simulate the pressure distributions of the flow fields inside three notches with their corresponding typical structural grooves in order to analyze the changes of restricted locations along with the openings and, furthermore, to calculate the flow areas of the notches. The accuracy of the employed model is demonstrated by comparing the computational results with the experimental data. Additionally, the flow rate vs. pressure drop data obtained from the experiment is fitted by least square method. On this basis, the discharge coefficient as a function of groove geometry, flow condition, fitting coefficients and its stable value is deduced, proving to be quite consistent with the experimental result. Thanks to the jet flow angles estimated by CFD simulation, the steady flow forces are calculated, which show good agreement with the experimental results except for some small differences. Finally, the throttling stiffness of the three notches is investigated, with that of divergent U-shape groove falls between spheroid-shape groove and triangle-shape groove. Similar results are found for steady flow force. The results indicate that the groove shape has significant effects on the flow characteristics (flow area, discharge

  17. Champagne Groove Lipectomy: A Safe Technique to Contour the Upper Abdomen in Abdominoplasty.

    Science.gov (United States)

    Brooks, Ron; Nguyen, Jonathan; Chowdhry, Saeed; Tutela, John Paul; Kelishadi, Sean; Yonick, David; Choo, Joshua; Wilhelmi, Bradon J

    2017-01-01

    Objective: Combined liposuction and abdominoplasty, or lipoabdominoplasty, is particularly helpful in sculpting a more aesthetically pleasing abdominal contour, particularly in the supraumbilical midline groove. This groove, coined the "champagne groove" by one of our patients, is a frequently sought-after attribute by patients. However, liposuction adds time and cost to an already costly abdominoplasty. We sought to create this groove without the addition of liposuction, utilizing what we call a champagne groove lipectomy. This study reports on our champagne groove lipectomy technique and compares our complication rates with those reported in the literature for standard abdominoplasty techniques. Methods: This is a retrospective review of a single surgeon's experience at our institution over a 6-year period (2007-2012). A total of 74 patients undergoing consecutive abdominoplasty were studied, all female nonsmokers. Two groups were recognized: 64 of 74 patients underwent abdominoplasty, partial belt lipectomy, and champagne groove lipectomy, while 10 of 74 patients underwent fleur-de-lis abdominoplasty without champagne groove lipectomy. Results: Overall, 10 of 74 patients (13.5%) suffered some type of complication, which compares favorably with reported rates in the literature. The majority of complications were related to delayed wound healing or superficial wound dehiscence. Among those patients who underwent champagne groove lipectomy, complications occurred in 6 of 64 patients (9.3%), versus 4 of 10 (40%) patients undergoing fleur-de-lis abdominoplasty. Conclusions: Champagne groove lipectomy is a cost-effective alternative to lipoabdominoplasty for achieving an aesthetically pleasing upper midline abdominal contour, with complication rates comparing favorably with those reported in the literature.

  18. High quality broadband spatial reflections of slow Rayleigh surface acoustic waves modulated by a graded grooved surface

    KAUST Repository

    Xu, Yanlong; Peng, Pai

    2015-01-01

    . The graded grooved surface is structured by drilling one dimensional array of graded grooves with increased depths on a flat surface. We investigate SAW dispersion relations, wave field distribution at several typical SAW wavelengths, and time evolution of a

  19. Pavement cracking measurements using 3D laser-scan images

    International Nuclear Information System (INIS)

    Ouyang, W; Xu, B

    2013-01-01

    Pavement condition surveying is vital for pavement maintenance programs that ensure ride quality and traffic safety. This paper first introduces an automated pavement inspection system which uses a three-dimensional (3D) camera and a structured laser light to acquire dense transverse profiles of a pavement lane surface when it carries a moving vehicle. After the calibration, the 3D system can yield a depth resolution of 0.5 mm and a transverse resolution of 1.56 mm pixel −1 at 1.4 m camera height from the ground. The scanning rate of the camera can be set to its maximum at 5000 lines s −1 , allowing the density of scanned profiles to vary with the vehicle's speed. The paper then illustrates the algorithms that utilize 3D information to detect pavement distress, such as transverse, longitudinal and alligator cracking, and presents the field tests on the system's repeatability when scanning a sample pavement in multiple runs at the same vehicle speed, at different vehicle speeds and under different weather conditions. The results show that this dedicated 3D system can capture accurate pavement images that detail surface distress, and obtain consistent crack measurements in repeated tests and under different driving and lighting conditions. (paper)

  20. The leaf phenophase of deciduous species altered by land pavements

    Science.gov (United States)

    Chen, Yuanyuan; Wang, Xiaoke; Jiang, Bo; Li, Li

    2018-02-01

    It has been widely reported that the urban environment alters leaf and flowering phenophases; however, it remains unclear if land pavement is correlated with these alterations. In this paper, two popular deciduous urban trees in northern China, ash (Fraxinus chinensis) and maple (Acer truncatum), were planted in pervious and impervious pavements at three spacings (0.5 m × 0.5 m, 1.0 m × 1.0 m, and 2.0 m × 2.0 m apart). The beginning and end dates of the processes of leaf budburst and senescence were recorded in spring and fall of 2015, respectively. The results show that leaf budburst and senescence were significantly advanced in pavement compared to non-pavement lands. The date of full leaf budburst was earlier by 0.7-9.3 days for ash and by 0.3-2.3 days for maple under pavements than non-pavements, respectively. As tree spacing increases, the advanced days of leaf budburst became longer. Our results clearly indicate that alteration of leaf phenophases is attributed to land pavement, which should be taken into consideration in urban planning and urban plant management.

  1. Determination of Tongue and Groove parameters for multileaf collimators; Determinaco de parametros de Tongue and Groove de colimadores de multilaminas

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Aluisio; Almeida, Carlos E. de, E-mail: alu_neto@hotmail.com [Universidade Estadual do Rio de Janeiro (UERJ), RJ (Brazil). Laboratorio de Ciencias Radiologicas; Nguyen, Bihn [Prowess Inc., Concord, CA (United States)

    2012-08-15

    The Tongue and Groove effect (TandG) is characterized by an additional attenuation between adjacent and opposing leaves on multileaf collimators (MLCs) in adjacent or complementary fields. This is a typical situation in of intensity-modulated radiotherapy treatments. The aim of this study was to measure the width and transmission of TandG effect for two commercial MLCs: Varian Millennium 120 (6 MV and 16 MV beams) and BrainLab m3 (only for 6 MV). The methodology used was based on the creation of MLC shapes that emphasizes TandG effect, the irradiation of these fields on radiochromic film and the sensitometric evaluation of the films in order to determine the TandG width and transmission. The results for TandG width for studied MLCs were 2.5, 1.8 and 2 mm, respectively, whit transmission TandG values of 87, 90 and 85%. (author)

  2. Drainage investigation of surface runoff for highway pavement

    Directory of Open Access Journals (Sweden)

    Al-adili Aqeel

    2018-01-01

    Full Text Available The aim of this study is to establish the effect of heavy rainfall and the chosen pavement layers on the drainage design, material selection and rutting resistance of the flexible pavement. The test in present study was started with wheel track passing without load and without rain falling on the pavement for a period of time, and it was noticed that no distress appeared on the surface of the pavement. Then, the load is gradually added by using wheel track load of 106 psi for five tests without rain falling and five other tests with gradually increasing rain fall duration and intensity. Deterioration and distresses appeared on the pavement when increasing the wheel track load to (150 psi under high intensity rain and long term duration of rain fall. By increasing the number of days, which is 103 days of study, when the pavement is saturated, the extra amount of the water will runoff. The clogging material which caused a decrease in the water seepage, increases the time of runoff ending. The clogging materials of fine particles that get deposited on the surface of the pavement resulted by passing the wheel track loading and wear & tear of the pavement surface, and other clogging materials such as salt in the water will penetrate to the pavement and seal the voids and decrease its water seepage. The water seepage decreases by increasing number of days, so the amount of the absorbed water decreases by 89% after 71 days of testing for high rain intensity (116 ml/min..

  3. Development of Improved Mechanistic Deterioration Models for Flexible Pavements

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ertman, Hans Larsen

    1998-01-01

    The paper describes a pilot study in Denmark with the main objective of developing improved mechanistic deterioration models for flexible pavements based on an accelerated full scale test on an instrumented pavement in the Danish Road Tessting Machine. The study was the first in "International...... Pavement Subgrade Performance Study" sponsored by the Federal Highway Administration (FHWA), USA. The paper describes in detail the data analysis and the resulting models for rutting, roughness, and a model for the plastic strain in the subgrade.The reader will get an understanding of the work needed...

  4. Adaptation of AASHTO Pavement Design Guide for Local Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hajek, J.J. [Applied Research Associates Inc., Toronto, ON (Canada)

    2001-07-01

    The methodology used to adapt the 1993 AASHTO Guide for Design of Pavement Structures to Ontario conditions was described. The guide expresses the effect of traffic loads on pavement performance using the concept of axle Load Equivalency Factors (LEF). LEF is regarded as a pavement damage factor assigned to each specific load and axle configuration. The size of LEF is related to the damage that is expected to occur from a standard load of 80 kN carried by a single axle with dual tires. The factors are summarized to yield the number of Equivalent Single Axle Loads (ESALs) a pavement is expected to sustain during its life. A summary was also provided of the additional work done to prepare for the transition to the proposed mechanistically-based 2002 AASHTO Guide. The paper focused only on the design of flexible pavements in terms of load characterization using equivalent single axle loads along with axle load spectra, below grade and material characterization, plus initial and terminal serviceability and reliability. The AASHTO Guide uses two parameters to deal with design reliability: design reliability level and overall standard deviation. Data collected on Ontario highway pavements and materials was used for assessing the design inputs. Other data was also collected from research and development studies, laboratory experiments, and from a survey of experienced pavement design engineers. The end result was a new grouping of Ontario soils for pavement design, recommended values for the resilient modulus of below grade soils, recommendations for structural layer coefficients for Ontario pavement materials and recommendations for the initial pavement serviceability based on Ontario smoothness specifications. Results of calibration and verification processes indicate that for new flexible pavements, the AASHTO-Ontario model is in good agreement with the observed results. It was recommended that the calibration and verification of the AASHTO-Ontario model should be a

  5. Validation of theoretical models through measured pavement response

    DEFF Research Database (Denmark)

    Ullidtz, Per

    1999-01-01

    mechanics was quite different from the measured stress, the peak theoretical value being only half of the measured value.On an instrumented pavement structure in the Danish Road Testing Machine, deflections were measured at the surface of the pavement under FWD loading. Different analytical models were...... then used to derive the elastic parameters of the pavement layeres, that would produce deflections matching the measured deflections. Stresses and strains were then calculated at the position of the gauges and compared to the measured values. It was found that all analytical models would predict the tensile...

  6. Climate change, energy, sustainability and pavements

    International Nuclear Information System (INIS)

    Gopalakrishnan, Kasthurirangan; Steyn, Wynand JvdM; Harvey, John

    2014-01-01

    Provides an integrated perspective on understanding the impacts of climate change, energy and sustainable development on transportation infrastructure systems. Presents recent technological innovations and emerging concepts in the field of green and sustainable transportation infrastructure systems with a special focus on highway and airport pavements. Written by leading experts in the field. Climate change, energy production and consumption, and the need to improve the sustainability of all aspects of human activity are key inter-related issues for which solutions must be found and implemented quickly and efficiently. To be successfully implemented, solutions must recognize the rapidly changing socio-techno-political environment and multi-dimensional constraints presented by today's interconnected world. As part of this global effort, considerations of climate change impacts, energy demands, and incorporation of sustainability concepts have increasing importance in the design, construction, and maintenance of highway and airport pavement systems. To prepare the human capacity to develop and implement these solutions, many educators, policy-makers and practitioners have stressed the paramount importance of formally incorporating sustainability concepts in the civil engineering curriculum to educate and train future civil engineers well-equipped to address our current and future sustainability challenges. This book will prove a valuable resource in the hands of researchers, educators and future engineering leaders, most of whom will be working in multidisciplinary environments to address a host of next-generation sustainable transportation infrastructure challenges.

  7. Review of ice and snow runway pavements

    Directory of Open Access Journals (Sweden)

    Greg White

    2018-05-01

    Full Text Available Antarctica is the highest, driest, coldest, windiest, most remote and most pristine place on Earth. Polar operations depend heavily on air transportation and support for personnel and equipment. It follows that improvement in snow and ice runway design, construction and maintenance will directly benefit polar exploration and research. Current technologies and design methods for snow and ice runways remain largely reliant on work performed in the 1950s and 1960s. This paper reviews the design and construction of polar runways using snow and ice as geomaterials. The inability to change existing snow and ice thickness or temperature creates a challenge for polar runway design and construction, as does the highly complex mechanical behaviour of snow, including the phenomena known as sintering. It is recommended that a modern approach be developed for ice and snow runway design, based on conventional rigid and flexible pavement design principles. This requires the development on an analytical model for the prediction of snow strength, based on snow age, temperature history and density. It is also recommended that the feasibility of constructing a snow runway at the South Pole be revisited, in light of contemporary snow sintering methods. Such a runway would represent a revolutionary advance for the logistical support of Antarctic research efforts. Keywords: Runway, Pavement, Snow, Ice, Antarctic

  8. Climate change, energy, sustainability and pavements

    Energy Technology Data Exchange (ETDEWEB)

    Gopalakrishnan, Kasthurirangan [Iowa State Univ., Ames, IA (United States). Dept. of Civil, Construction and Environmental Engineering; Steyn, Wynand JvdM [Pretoria Univ. (South Africa). Dept. of Civil Engineering; Harvey, John (ed.) [California Univ., Davis, CA (United States). Dept. of Civil and Environmental Engineering

    2014-07-01

    Provides an integrated perspective on understanding the impacts of climate change, energy and sustainable development on transportation infrastructure systems. Presents recent technological innovations and emerging concepts in the field of green and sustainable transportation infrastructure systems with a special focus on highway and airport pavements. Written by leading experts in the field. Climate change, energy production and consumption, and the need to improve the sustainability of all aspects of human activity are key inter-related issues for which solutions must be found and implemented quickly and efficiently. To be successfully implemented, solutions must recognize the rapidly changing socio-techno-political environment and multi-dimensional constraints presented by today's interconnected world. As part of this global effort, considerations of climate change impacts, energy demands, and incorporation of sustainability concepts have increasing importance in the design, construction, and maintenance of highway and airport pavement systems. To prepare the human capacity to develop and implement these solutions, many educators, policy-makers and practitioners have stressed the paramount importance of formally incorporating sustainability concepts in the civil engineering curriculum to educate and train future civil engineers well-equipped to address our current and future sustainability challenges. This book will prove a valuable resource in the hands of researchers, educators and future engineering leaders, most of whom will be working in multidisciplinary environments to address a host of next-generation sustainable transportation infrastructure challenges.

  9. Application of Conductive Materials to Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    Hai Viet Vo

    2017-01-01

    Full Text Available Snow-melting pavement technique is an advanced preservation method, which can prevent the forming of snow or ice on the pavement surface by increasing the temperature using an embedded heating system. The main scope of this study is to evaluate the impact of conductive additives on the heating efficiency. The electrical resistivity and thermal conductivity were considered to investigate effects of conductive additives, graphite, and carbon fibers on the snow-melting ability of asphalt mixtures. Also, the distribution of the conductive additives within the asphalt concrete body was investigated by microstructural imaging. An actual test was applied to simulate realistic heating for an asphalt concrete mixture. Thermal testing indicated that graphite and carbon fibers improve the snow-melting ability of asphalt mixes and their combination is more effective than when used alone. As observed in the microstructural image, carbon fibers show a long-range connecting effect among graphite conductive clusters and gather in bundles when added excessively. According to the actual test, adding the conductive additives helps improve snow-melting efficiency by shortening processing time and raising the surface temperature.

  10. The comparisons of computational models of pavement due to the dynamic load act

    Directory of Open Access Journals (Sweden)

    Valašková Veronika

    2017-01-01

    Full Text Available Finite element method (FEM is frequently used to solve current problems of the structural mechanics in engineering practice. The dynamic interaction of the two systems is one of the topics that can be solved using FEM. To simplify the solution of the interaction, it is possible to divide the system in two independent subsystems, vehicle and pavement. Computing software ADINA, based on the principles of the finite element modelling, was adopted to solve the given problem. The results from the first computational model can be used as the inputs for the second model. To analyse stress state of the pavement with different composition, three specific types of pavements were selected – concrete pavement, semi-rigid pavement and flexible pavement. The pavements represent the typical pavement types used for the regular road structures. This article is focused on the analysis of the stress state and the displacements of the pavement induced by the moving load from the traffic.

  11. An Innovative Cellular Automata Technique for Mapping Cracking Pattern of Airport Pavement

    Directory of Open Access Journals (Sweden)

    Yin Fucheng

    2017-01-01

    Full Text Available In this study, an innovative cellular automata (CA technique was proposed for mapping cracking pattern of the airport pavement. The CA technique was developed to establish a numerical model describing the effect of boundary condition of pavement on zones (CA cells within the pavement. A state function was used to describe the state values in the cells within the CA lattice. The correction coefficient principle is used as the criterion of zone similarity and the corresponding technique is proposed to find similar zones within and between pavements. Three pavement models, HRS, MRS and LRS, tested in FAA, USA, are set as the base pavements to map the cracking patterns of pavements with different sizes from the base pavements. The mapped cracking patterns of unseen pavements are empirically verified by referring to the relative experimental models.

  12. Cost-Effective Pavement Performance Management of Indiana's Enhanced National Highway System through Strategic Modification of the Pavement Rehabilitation Treatment Trigger Values

    OpenAIRE

    Noureldin, Menna; Fricker, Jon D.; Sinha, Kumares C.

    2015-01-01

    Cost-Effective Pavement Performance Management of Indiana's Enhanced National Highway System through Strategic Modification of the Pavement Rehabilitation Treatment Trigger Values Presented during Session 3: Policy and Funding, moderated by Magdy Mikhail, at the 9th International Conference on Managing Pavement Assets (ICMPA9) in Alexandria, VA. Includes conference paper and PowerPoint slides.

  13. Long-term Performance of Granular Bases Including the Effect of Wet-Dry Cycles on Inverted Base Pavement Performance

    Science.gov (United States)

    2017-06-01

    The main objective of this study was to advance the understanding of alternative pavement designs. In particular, potential techniques such as inverted base pavements (IBP) have increased the importance of granular aggregate bases (GAB) in pavement s...

  14. Laser melting of groove defect repair on high thermal conductivity steel (HTCS-150)

    Science.gov (United States)

    Norhafzan, B.; Aqida, S. N.; Fazliana, F.; Reza, M. S.; Ismail, I.; Khairil, C. M.

    2018-02-01

    This paper presents laser melting repair of groove defect on HTCS-150 surface using Nd:YAG laser system. Laser melting process was conducted using JK300HPS Nd:YAG twin lamp laser source with 1064 nm wavelength and pulsed mode. The parameters are pulse repetition frequency (PRF) that is set from 70 to 100 Hz, average power ( P A) of 50-70 W, and laser spot size of 0.7 mm. HTCS-150 samples were prepared with groove dimension of 0.3 mm width and depths of 0.5 mm using EDM wire cut. Groove defect repaired using laser melting process on groove surface area with various parameters' process. The melted surface within the groove was characterized for subsurface hardness profile, roughness, phase identification, chemical composition, and metallographic study. The roughness analysis indicates high PRF at large spot size caused high surface roughness and low surface hardness. Grain refinement of repaired layer was analyzed within the groove as a result of rapid heating and cooling. The hardness properties of modified HTCS inside the groove and the bulk surface increased two times from as received HTCS due to grain refinement which is in agreement with Hall-Petch equation. These findings are significant to parameter design of die repair for optimum surface integrity and potential for repairing crack depth and width of less than 0.5 and 0.3 mm, respectively.

  15. Effect of groove on socket welds under the condition of vibration fatigue

    International Nuclear Information System (INIS)

    Xiu, Junjie; Jing, Hongyang; Han, Yongdian; Zhao, Lei; Xu, Lianyong

    2013-01-01

    Root failures of socket welds in small bore piping caused by vibration mainly occur at nuclear power plants (NPPs). It was observed that at higher stress level failures tended to originate at the toe while for the case of lower stress failures tended to occur at the root. The groove can increase the penetration depth (PD) of root, which is beneficial to the fatigue life. The effect of groove was also investigated by finite element method (FEM). The simulation results show that groove can decline the stress distribution, stress triaxiality and maximum principal plastic strain in the weld root, and the 5 mm groove suffering σ max (the highest stress of root failure) is almost same as no groove subjecting to σ f (fatigue limit). The test results show that the socket weld with groove can increase the natural frequency and damping of specimen, which make the system more difficult to vibrate. Moreover, the groove can also improve the fatigue property of specimen which do not exist the root failure even under high cycle fatigue (HCF)

  16. The MLC tongue-and-groove effect on IMRT dose distributions

    Energy Technology Data Exchange (ETDEWEB)

    Deng Jun [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305 (United States). E-mail: jun@reyes.stanford.edu; Pawlicki, Todd; Chen Yan; Li Jinsheng; Jiang, Steve B.; Ma, C.-M. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305 (United States)

    2001-04-01

    We have investigated the tongue-and-groove effect on the IMRT dose distributions for a Varian MLC. We have compared the dose distributions calculated using the intensity maps with and without the tongue-and-groove effect. Our results showed that, for one intensity-modulated treatment field, the maximum tongue-and-groove effect could be up to 10% of the maximum dose in the dose distributions. For an IMRT treatment with multiple gantry angles ({>=} 5), the difference between the dose distributions with and without the tongue-and-groove effect was hardly visible, less than 1.6% for the two typical clinical cases studied. After considering the patient setup errors, the dose distributions were smoothed with reduced and insignificant differences between plans with and without the tongue-and-groove effect. Therefore, for a multiple-field IMRT plan ({>=} 5), the tongue-and-groove effect on the IMRT dose distributions will be generally clinically insignificant due to the smearing effect of individual fields. The tongue-and-groove effect on an IMRT plan with small number of fields (<5) will vary depending on the number of fields in a plan (coplanar or non-coplanar), the MLC leaf sequences and the patient setup uncertainty, and may be significant (>5% of maximum dose) in some cases, especially when the patient setup uncertainty is small ({<=} 2 mm). (author)

  17. The effect of expert performance microtiming on listeners’ experience of groove in swing or funk music

    Directory of Open Access Journals (Sweden)

    Olivier Senn

    2016-10-01

    Full Text Available This study tested the influence of expert performance microtiming on listeners' groove experience. Two professional rhythm section (bass/drums performances in swing and funk style were recorded, and the performances' original microtemporal deviations from a regular metronomic grid were scaled to several magnitude levels. Music expert (n=79 and non-expert (n=81 listeners rated the groove qualities of stimuli using a newly developed questionnaire that measures three dimensions of the groove experience (Entrainment, Enjoyment, and the absence of Irritation. Findings show that music expert listeners were more sensitive to microtiming manipulations than non-experts. Across both expertise groups and for both styles, groove ratings were high for microtiming magnitudes equal or smaller than those originally performed and decreased for exaggerated microtiming magnitudes. In particular, both the fully quantized music and the music with the originally performed microtiming pattern were rated equally high on groove. This means that neither the claims of PD theory (that microtiming deviations are necessary for groove nor the opposing exactitude hypothesis (that microtiming deviations are detrimental to groove were supported by the data.

  18. Microcirculation within Grooved Substrates regulates Cell Positioning and Cell Docking inside Microfluidic Channels

    Science.gov (United States)

    Manbachi, Amir; Shrivastava, Shamit; Cioffi, Margherita; Chung, Bong Geun; Moretti, Matteo; Demirci, Utkan; Yliperttula, Marjo; Khademhosseini, Ali

    2009-01-01

    Immobilization of cells inside microfluidic devices is a promising approach for enabling studies related to drug screening and cell biology. Despite extensive studies in using grooved substrates for immobilizing cells inside channels, a systematic study of the effects of various parameters that influence cell docking and retention within grooved substrates has not been performed. We demonstrate using computational simulations that the fluid dynamic environment within microgrooves significantly varies with groove width, generating micro-circulation areas in smaller microgrooves. Wall shear stress simulation predicted that shear stresses were in opposite direction in smaller grooves (25 and 50 μm wide) in comparison to those in wider grooves (75 and 100 μm wide). To validate the simulations, cells were seeded within microfluidic devices, where microgrooves of different widths were aligned perpendicularly to the direction of the flow. Experimental results showed that, as predicted, the inversion of the local direction of shear stress within the smaller grooves resulted in alignment of cells on two opposite sides of the grooves under the same flow conditions. Also, the amplitude of shear stress within microgrooved channels significantly influenced cell retainment in the channels. Therefore, our studies suggest that microscale shear stresses greatly influence cellular docking, immobilization, and retention in fluidic systems and should be considered for the design of cell-based microdevices. PMID:18432345

  19. A stereological approach for measuring the groove angles of intergranular corrosion

    International Nuclear Information System (INIS)

    Gwinner, B.; Borgard, J.-M.; Dumonteil, E.; Zoia, A.

    2017-01-01

    Highlights: • The ICG morphology has been characterized in 3D by X-ray μ-tomography. • The measurement of the angles of the IGC groove on 2D cross sections induces a bias. • A methodology is proposed to estimate the true value of the IGC groove angles in 3D. - Abstract: Non-sensitized austenitic stainless steels can be prone to intergranular corrosion when they are in contact with an oxidizing medium like nitric acid. Intergranular corrosion is characterized by the formation of grooves along the grain boundaries. The angle of these grooves is a key parameter, which directly informs of the intergranular corrosion kinetics. Most of the time, the angles of the grooves are experimentally measured on 2-dimensional cross sections of the corroded samples. This study discusses the relationship between the groove angle measured on 2-dimensional sections and the true groove angle in 3-dimensional space. This approach could also be easily extended to the study of crack angle in the domains of corrosion-fatigue, stress corrosion cracking or mechanical fracture.

  20. Investigation of enhanced condensation heat transfer outside vertical titanium circularly-grooved tube

    International Nuclear Information System (INIS)

    Zhaorigetu; Huang Weitang; Lv Xiangbo; Liu Feng

    2005-01-01

    The investigation of enhanced condensation heat transfer had been conducted on the outside vertical Titanium circularly-grooved tube. The experimental result indicates that the Titanium circularly-grooved tube is fairly efficient in enhancing the heat transfer. Within the experimental scope, the total heat transfer coefficient of the optimum circularly-grooved tube is 1.12 to 1.36 times of that of the Titanium smooth tube. Through regression analysis on the experimental data, the experimental correlations for the inside heat transfer coefficient, the condensation heat transfer coefficient on film condensation and the friction coefficient were achieved. (authors)

  1. Unusual stress fracture in an adolescent baseball pitcher affecting the trochlear groove of the olecranon

    International Nuclear Information System (INIS)

    Blake, Joseph J.; Block, John J.; Kan, J.H.; Hannah, Gene A.

    2008-01-01

    Stress fractures of the proximal ulna are known to occur in throwing athletes. Most cases extend to involve the olecranon, and cases limited to the trochlear groove are rare. In this report we present a 17-year-old elite baseball pitcher with a stress fracture of the trochlear groove of the proximal ulna. Diagnosis was made by demonstration of characteristic signal changes on MRI of the elbow. The fracture occurred at the cortical notch, also known as the pseudodefect of the trochlear groove. This case suggests that the cortical notch serves as an area of weakness predisposing pitchers to development of a stress fracture. (orig.)

  2. Mathematical modeling of photovoltaic thermal PV/T system with v-groove collector

    Science.gov (United States)

    Zohri, M.; Fudholi, A.; Ruslan, M. H.; Sopian, K.

    2017-07-01

    The use of v-groove in solar collector has a higher thermal efficiency in references. Dropping the working heat of photovoltaic panel was able to raise the electrical efficiency performance. Electrical and thermal efficiency were produced by photovoltaic thermal (PV/T) system concurrently. Mathematical modeling based on steady-state thermal analysis of PV/T system with v-groove was conducted. With matrix inversion method, the energy balance equations are explained by means of the investigative method. The comparison results show that in the PV/T system with the V-groove collector is higher temperature, thermal and electrical efficiency than other collectors.

  3. Metal concentrations from permeable pavement parking lot in Edison, NJ

    Data.gov (United States)

    U.S. Environmental Protection Agency — The U.S. Environmental Protection Agency constructed a 4000-m2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements...

  4. Sustainable Mitigation of Stormwater Runoff Through Fully Permeable Pavement

    Science.gov (United States)

    2018-03-01

    This report presents the implementation of new design method developed using mechanistic-empirical design approach by University of California Pavement Research Center (UCPRC) through building two test sections at California State University Long Bea...

  5. Evaluation of acceptance strength tests for concrete pavements.

    Science.gov (United States)

    2005-06-30

    The North Carolina Department of Transportation has used traditionally flexural strength tests for acceptance : testing of Portland cement concrete pavements. This report summarizes a research project implemented to : investigate the feasibility of u...

  6. Effect of friction on rolling tire-pavement interaction.

    Science.gov (United States)

    2010-11-01

    Accurate modeling of tirepavement contact behavior (i.e., distribution of contact tractions at the : interface) plays an important role in the analysis of pavement performance and vehicle driving safety. : The tirepavement contact is essentiall...

  7. Prediction of thermal behavior of pervious concrete pavements in winter.

    Science.gov (United States)

    2017-05-15

    Because application of pervious concrete pavement (PCPs) has extended to cold-climate regions of the United States, the safety and : mobility of PCP installations during the winter season need to be maintained. Timely application of salt, anti-icing,...

  8. Pavement evaluation - an international perspective: Fit for purpose?

    OpenAIRE

    Wix, Richard

    2014-01-01

    Plenary Session 1 Moderated by Edgar de León Izeppi This presentation was held at the Pavement Evaluation 2014 Conference, which took place from September 15-18, 2014 in Blacksburg, Virginia. Presentation only

  9. Ultra thin continuously reinforced concrete pavement research in south Africa

    CSIR Research Space (South Africa)

    Perrie, BD

    2007-08-01

    Full Text Available Ultra thin continuously reinforced concrete pavements (UTCRCP), in literature also referred to as Ultra Thin Reinforced High Performance Concrete (UTHRHPC), have been used in Europe successfully as a rehabilitation measure on steel bridge decks...

  10. DURABILITY OF FLEXIBLE PAVEMENTS: A CASE STUDY OF ...

    African Journals Online (AJOL)

    user

    years, ranking, predominant factors affecting pavement durability and the estimate of durability. In this regard .... subgrade soil into the base course and provide the drainage of ..... [3] Oguara T. M. “A management model for road infrastructure ...

  11. Safety performance evaluation of converging chevron pavement markings : final report.

    Science.gov (United States)

    2014-12-01

    The objectives of this study were (1) to perform a detailed safety analysis of converging chevron : pavement markings, quantifying the potential safety benefits and developing an understanding of the : incident types addressed by the treatment, and (...

  12. sensitivity analysis on flexible road pavement life cycle cost model

    African Journals Online (AJOL)

    user

    of sensitivity analysis on a developed flexible pavement life cycle cost model using varying discount rate. The study .... organizations and specific projects needs based. Life-cycle ... developed and completed urban road infrastructure corridor ...

  13. Ground penetrating radar evaluation of new pavement density.

    Science.gov (United States)

    2015-02-01

    The objective of this project was to map pavement surface density variations using dielectric : measurements from ground penetrating radar (GPR). The work was carried out as part of an : Asphalt Intelligent Compaction demonstration project on SR 539 ...

  14. Texas pavement preservation center two-year summary report.

    Science.gov (United States)

    2011-08-01

    Established August 11, 2005, The TPPC serves the broad range of needs of the Texas Department of Transportation (TxDOT), and other agencies within the highway community by promoting awareness of pavement preservation as a feasible and practical maint...

  15. Texas pavement preservation center four-year summary report.

    Science.gov (United States)

    2009-07-04

    The Texas Pavement Preservation Center (TPPC), in joint collaboration with the Center for Transportation Research (CTR) of the University of Texas at Austin and the Texas Transportation Institute (TTI) of Texas A&M University, promotes the use of pav...

  16. Mobile geographic information system (GIS) solution for pavement condition surveys.

    Science.gov (United States)

    2012-06-28

    This report discusses the design and implementation of a software-based solution that will improve the data collection processes during the Pavement Condition Surveys (PCS) conducted by the State Materials Office (SMO) of the Florida Department of Tr...

  17. Investigation clogging dynamic of permeable pavement systems using embeded sensors

    Data.gov (United States)

    U.S. Environmental Protection Agency — Permeable pavement is a stormwater control measure commonly selected in both new and retrofit applications. However, there is limited information about the clogging...

  18. Calibration of controlling input models for pavement management system.

    Science.gov (United States)

    2013-07-01

    The Oklahoma Department of Transportation (ODOT) is currently using the Deighton Total Infrastructure Management System (dTIMS) software for pavement management. This system is based on several input models which are computational backbones to dev...

  19. Pavement subgrade MR design values for Michigan's seasonal changes : appendices.

    Science.gov (United States)

    2009-07-22

    The resilient modulus (MR) of roadbed soil plays an integral role in the design of pavement systems. Currently, the various regions of the Michigan Department of Transportation (MDOT) use different procedures to determine the MR values. Most of these...

  20. Iowa pavement asset management decision-making framework.

    Science.gov (United States)

    2015-10-01

    Most local agencies in Iowa currently make their pavement treatment decisions based on their limited experience due primarily to : lack of a systematic decision-making framework and a decision-aid tool. The lack of objective condition assessment data...

  1. Benefits and assessment of annual budget requirements for pavement preservation.

    Science.gov (United States)

    2012-01-01

    This research identifies methods and best practices that can be used by the Indiana Department of Transportation (INDOT) in : performing various strategies for pavement preservation. It also identifies various methods of calculating the benefits of :...

  2. Evaluation of the use of snowplowable raised pavement markers.

    Science.gov (United States)

    2009-04-01

    The objective of this study was to evaluate the effectiveness and durability of snowplowable raised pavement markers (RPM) installed on the RPM system in Kentucky. The durability evaluation dealt wit the marker housing. : The data show that continued...

  3. Use of nondestructive evaluation to detect moisture in flexible pavements.

    Science.gov (United States)

    2006-01-01

    The purpose of this study was to identify the currently available nondestructive evaluation technology that holds the greatest potential to detect moisture in flexible pavements and then apply the technology in multiple locations throughout Virginia....

  4. Evaluation of portable retroreflectometer for use on pavement marking materials.

    Science.gov (United States)

    1981-01-01

    The subjective rating of the night visibility of pavement marking materials is difficult as it can be influenced by many variables. In an attempt to provide an improved method of determining the night visibility of these materials, a portable retrore...

  5. Tack coat optimization for HMA overlays : accelerated pavement test report.

    Science.gov (United States)

    2009-02-01

    Interface bonding between hot-mix asphalt (HMA) overlays and Portland cement concrete (PCC) pavements is one : of the most significant factors affecting overlay service life. This study was performed to quantify the effects of HMA type, : tack coat t...

  6. Implementation of warm-mix asphalt mixtures in Nebraska pavements.

    Science.gov (United States)

    2012-07-01

    The primary objective of this research is to evaluate the feasibility of several WMA mixtures as potential asphalt paving : mixtures for Nebraska pavements. To that end, three well-known WMA additives (i.e., Sasobit, Evotherm, and Advera : synthetic ...

  7. Life cycle and economic efficiency analysis: durable pavement markings.

    Science.gov (United States)

    2009-07-01

    This project examined the life cycle and economic efficiency of two pavement marking : materials inlaid tape and thermoplastic to find the most economical product for specific : traffic and weather conditions. Six locations in the state of Ma...

  8. Long-Term Field Performance of Pervious Concrete Pavement

    Directory of Open Access Journals (Sweden)

    Aleksandra Radlińska

    2012-01-01

    Full Text Available The work described in this paper provides an evaluation of an aged pervious concrete pavement in the Northeastern United States to provide a better understanding of the long-lasting effects of placement techniques as well as the long-term field performance of porous pavement, specifically in areas susceptible to freezing and thawing. Multiple samples were taken from the existing pavement and were examined in terms of porosity and unit weight, compressive and splitting tensile strength, and the depth and degree of clogging. It was concluded that improper placement and curing led to uneven pavement thickness, irregular pore distribution within the pervious concrete, and highly variable strength values across the site, as well as sealed surfaces that prevented infiltration.

  9. Development of an Overlay Design Procedure for Composite Pavements

    Science.gov (United States)

    2017-09-01

    The composite overlay design procedure currently used by ODOT sometimes produces very large overlay thicknesses that are deemed structurally unnecessary, especially for composite pavements already with thick asphalt overlays. This study was initiated...

  10. stabilization of dredged spoils for pavement construction in the niger

    African Journals Online (AJOL)

    Dr. Tse

    Natural soils underlying the East-West road are mainly clay and silt of poor quality ... on the dredged soils included particle size distribution, compaction and California ... KEYWORDS: Stabilization, dredge spoil, pavement, Niger Delta, cement.

  11. ANALYSIS OF GROUP MAINTENANCE STRATEGY -ROAD PAVEMENT AND SEWERAGE PIPES-

    Science.gov (United States)

    Tanimoto, Keishi; Sugimoto, Yasuaki; Miyamoto, Shinya; Nada, Hideki; Hosoi, Yoshihiko

    Recently, it is critical to manage deteriorating sewerage and road facilities efficiently and strategically. Since the sewerage pipes are mostly installed under road pavement, the works for the replacement of the sewerage pipes are partially common to the works for the road. This means that the replacement cost can be saved by coordinating the timing of the replacements by sewerage pipe and road pavement. The purpose of the study is to develop the model based on Markov decision process to derive the optimal group maintenance policy so as to minimize lifecycle cost. Then the model is applied to case study area and demonstrated to estimate the lifecycle cost using statistical data such as pipe replacement cost, road pavement rehabilitation cost, and state of deterioration of pipes and road pavement.

  12. Recycled tires as coarse aggregate in concrete pavement mixtures.

    Science.gov (United States)

    2013-07-01

    The reuse potential of tire chips as coarse aggregates in pavement concrete was examined in this research by : investigating the effects of low- and high-volume tire chips on fresh and hardened concrete properties. One concrete : control mixture was ...

  13. Benefit cost models to support pavement management decisions.

    Science.gov (United States)

    2012-06-01

    A critical role of pavement management is to provide decision makers with estimates of the required budget level to achieve specific steady-state network conditions, and to recommend the best allocation of available budget among competing needs for m...

  14. Fatigue and rutting strain analysis of flexible pavements designed ...

    African Journals Online (AJOL)

    ELO

    The study was carried out with the layered elastic analysis software EVERSTRESS. Key words: Layered elastic analysis, fatigue, rutting, strains, design, flexible pavement, CBR. ..... Numerical Computational Stresses and Strains in Multi-Layer ...

  15. Inverted base pavements : new field test and design catalogue.

    Science.gov (United States)

    2014-01-01

    The current economic situation has severely affected the US road infrastructure and funding has become : inadequate for either maintenance or future growth. : The inverted base pavement structure is a promising alternative to achieve high quality roa...

  16. Pavement management system for City of Madison : research brief.

    Science.gov (United States)

    2016-11-01

    Keeping city streets in good state of repair has been a significant challenge for small communities : where both road repair budgets and staff resources are lacking. To prevent pavement deterioration at : a large scale, local governments need to find...

  17. MDOT Pavement Management System : Prediction Models and Feedback System

    Science.gov (United States)

    2000-10-01

    As a primary component of a Pavement Management System (PMS), prediction models are crucial for one or more of the following analyses: : maintenance planning, budgeting, life-cycle analysis, multi-year optimization of maintenance works program, and a...

  18. SDDOT'S enhanced pavement management system : visual distress survey manual [2017

    Science.gov (United States)

    2017-05-11

    In 1993, the South Dakota Department of Transportation initiated the Research Project SD93-14, Enhancement of South Dakotas Pavement Management System. As the Research Project progressed, it was determined that to better evaluate the condition of ...

  19. Pavement management system review : final report, October 2009.

    Science.gov (United States)

    2009-10-01

    The University of Alabama (UA) researchers worked with Alabama Department of Transportation (ALDOT) managers to investigate various mechanisms to provide quality control of data collection and interpretation for pavements, and to target the data resu...

  20. Assessment of Asphalt Concrete Reinforcement Grid in Flexible Pavements

    Science.gov (United States)

    2016-05-01

    successfully used as interlayers include asphalt rubber and geotextiles, and the applica- tion of recycling techniques to rework the upper 2–4 in. of the...from a set of weights dropped from increasingly greater predetermined heights onto a rubber buffer system connected to a 12 in. diameter segmented...pavement temperature at depth, IR = the infrared pavement surface temperature (°C), D = the asphalt depth to estimate the temperature (mm), 1

  1. Application of surplus and waste materials in roads pavement making

    OpenAIRE

    Mousavi, S. M.; Fazli, A. H.; Rouzmehr, F.

    2011-01-01

    Nowadays there are a lot of problems about surpluses and debris made by humans all around the world. Lots of these surpluses seriously harm our natural environment. Reuse of this kind of materials in other processes like building constructions or pavement help our natural environment in every aspect. Asphalt concrete is the main part of pavements in most parts of the world with an increasing rate of production in need of more ways and roads. In this paper we will provide...

  2. Evaluation of Nontraditional Airfield Pavement Surfaces for Contingency Operations

    Science.gov (United States)

    2014-01-01

    double, triple seals, and cape seals have been used in various airports in the Australian territories (such as Cocos Island) with triple seals and cape...polymers, or fibers with the natural soil. In stabilizing soil, strength, durability, cohesion, and reduced swelling properties may be improved (UFC...2012. Cocos (Keeling) Island Aircraft pavement refurbishment project. Presentation provided by S. Emery, 5 May 2013. Ellis, C. I. 1979. Pavement

  3. Pavement-Watering for Cooling the Built Environment: A Review

    OpenAIRE

    Hendel , Martin

    2016-01-01

    Pavement-watering is being considered by decision-makers in many cities as a means of cooling the built environment and of adapting to rising extreme heat events due to climate change. In this article we review the existing literature on the topic of pavement-watering. We first focus on the methodological choices made in the literature, including study approach and scale, watering methods used as well as how results are analyzed. We then discuss the cooling effects reported, separating micro-...

  4. Evaluation of pavement skid resistance using high speed texture measurement

    Directory of Open Access Journals (Sweden)

    Jay N. Meegoda

    2015-12-01

    Full Text Available Skid resistance is an important parameter for highway designs, construction, management, maintenance and safety. The purpose of this manuscript is to propose the correlation between skid resistance, which is measured as skid resistance trailer, and mean profile depth (MPD or the macro surface texture, which is measured by vehicle mounted laser, so that highway agencies can predict the skid resistance of pavement without the use of expensive and time consuming skid resistance trailer, which also causes disruption of traffic in use. In this research skid numbers and MPD from 5 new asphalt pavements and 4 old asphalt pavements were collected using a locked wheel skid trailer and a vehicle mounted laser. Using the data collected, a correlation between the skid number (SN40R collected by locked wheel skid tester and the texture data or MPD collected by a vehicle mounted laser operating at highway speeds was developed. The proposed correlation for new pavements was positive for MPD values less than 0.75 mm to reach a peak SN40R value, then there was a negative correlation as the MPD increases until the MPD value was equal to 1.1 mm and beyond the MPD value of 1.1 mm to the maximum value of 1.4 mm, SN40R value remained almost constant. There were significant data scatter for the MPD value of 0.8 mm. To explain these results, water film thickness during the friction test was calculated and the critical MPD was defined. The effect of sealed water pool on the SN40R was discussed. The test result showed a similar trend for older asphalt pavements, but with lower SN40R values due to the polishing of pavement micro-texture by traffic. Hence, a reduction factor was proposed for older pavements based on cumulative traffic volume for the above correlation to predict the skid resistance of older pavements.

  5. Following the canyon to reach and remove olfactory groove meningiomas.

    Science.gov (United States)

    Stefini, Roberto; Zenga, Francesco; Giacomo, Esposito; Bolzoni, Andrea; Tartara, Fulvio; Spena, Giannantonio; Ambrosi, Claudia; Fontanella, Marco M

    2017-04-01

    Olfactory groove meningiomas (OGMs) represent approximately 10% of all intracranial meningiomas. They arise in the olfactory fossa, a variable depression delimited by the lateral lamella and perpendicular plate. The cribriform plate with the lateral lamella and ethmoidal and orbital roof could be viewed as a 'canyon' with the frontal sinus as the main entrance. Between January 2000 and December 2013, 32 consecutive patients underwent removal of OGMs through this 'canyon' at the Department of Neurosurgery of Brescia and Turin. Complete removal was achieved in all patients with this trans-frontal sinus subcranial approach (Simpson grade I; mean lesion volume, 46.6 cm3). Five patients (15.6%) experienced nasal CSF leakage, treated with external lumbar drain positioning for 4 days and resolved in all cases but one, which was re-operated. Two patients (6.2%) during the CSF leakage experienced meningitis at day 7 after surgery, both successfully treated by intravenous antibiotic therapy. After one month, one patient developed hydrocephalus, treated with a ventricular peritoneal shunt. In one patient, traction on the OGM caused bleeding of the callosomarginal artery, which was coagulated with superior frontal gyrus ischemia without neurological consequences. Glasgow Outcome Scale Score at 6 months was V in 29 patients, IV in one patient, and I in two patients. Advantages with this approach may include easy and early control of blood supply from its insertion in the skull base, minimal frontal lobe retraction, preservation of the frontal veins draining to the sagittal sinus, and a satisfactory aesthetic outcome.

  6. Traction suture modification to tongue-in-groove caudal septoplasty.

    Science.gov (United States)

    Indeyeva, Y A; Lee, T S; Gordin, E; Chan, D; Ducic, Y

    2018-02-01

    Caudal septal deviation leads to unfavorable esthetic as well as functional effects on the nasal airway. A modification to the tongue-in-groove (TIG) technique to correct these caudal septal deformities is described. With placement of a temporary suspension suture to the caudal septum, manual traction is applied, assuring that the caudal septum remains in the midline position while it is being secured with multiple through-and-through, trans-columellar and trans-septal sutures. From 2003 to 2016, 148 patients underwent endonasal septoplasty using this modified technique, with excellent functional and cosmetic outcomes and a revision rate of 1.4%. This modified TIG technique replaces the periosteal suture that secures the caudal septum to the midline nasal crest in the original TIG technique. This simplifies the procedure and minimizes the risk of securing the caudal septum off-midline when used in endonasal septoplasty. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  7. Condensation and evaporation transitions in deep capillary grooves

    International Nuclear Information System (INIS)

    Malijevský, Alexandr; Parry, Andrew O

    2014-01-01

    We study the order of capillary condensation and evaporation transitions of a simple fluid adsorbed in a deep capillary groove using a fundamental measure density functional theory (DFT). The walls of the capillary interact with the fluid particles via long-ranged, dispersion, forces while the fluid-fluid interaction is modelled as a truncated Lennard–Jones-like potential. We find that below the wetting temperature T w condensation is first-order and evaporation is continuous with the metastability of the condensation being well described by the complementary Kelvin equation. In contrast above T w both phase transitions are continuous and their critical singularities are determined. In addition we show that for the evaporation transition above T w there is an elegant mapping, or covariance, with the complete wetting transition occurring at a planar wall. Our numerical DFT studies are complemented by analytical slab model calculations which explain how the asymmetry between condensation and evaporation arises out of the combination of long-ranged forces and substrate geometry. (paper)

  8. Condensation and evaporation transitions in deep capillary grooves.

    Science.gov (United States)

    Malijevský, Alexandr; Parry, Andrew O

    2014-09-03

    We study the order of capillary condensation and evaporation transitions of a simple fluid adsorbed in a deep capillary groove using a fundamental measure density functional theory (DFT). The walls of the capillary interact with the fluid particles via long-ranged, dispersion, forces while the fluid-fluid interaction is modelled as a truncated Lennard-Jones-like potential. We find that below the wetting temperature Tw condensation is first-order and evaporation is continuous with the metastability of the condensation being well described by the complementary Kelvin equation. In contrast above Tw both phase transitions are continuous and their critical singularities are determined. In addition we show that for the evaporation transition above Tw there is an elegant mapping, or covariance, with the complete wetting transition occurring at a planar wall. Our numerical DFT studies are complemented by analytical slab model calculations which explain how the asymmetry between condensation and evaporation arises out of the combination of long-ranged forces and substrate geometry.

  9. Characterisation of a grooved heat pipe with an anodised surface

    Science.gov (United States)

    Solomon, A. Brusly; Ram Kumar, A. M.; Ramachandran, K.; Pillai, B. C.; Senthil Kumar, C.; Sharifpur, Mohsen; Meyer, Josua P.

    2017-03-01

    A grooved heat pipe (GHP) is an important device for managing heat in space applications such as satellites and space stations, as it works efficiently in the absence of gravity. Apart from the above application, axial GHPs are used in many applications, such as electronic cooling units for temperature control and permafrost cooling. Improving the performance of GHPs is essential for better cooling and thermal management. In the present study, the effect of anodization on the heat transfer characteristics of a GHP is studied with R600a as a working fluid. In addition, the effects of fill ratio, inclination angle and heat inputs on the heat transfer performance of a GHP are studied. Furthermore, the effect of heat flux on dimensional numbers, such as the Webber, Bond, Kutateladze and condensation numbers, are studied. The inclination angle, heat input and fill ratio of GHPs are varied in the range of 0°-90°, 25-250 W and 10-70 % respectively. It is found that the above parameters have a significant effect on the performance of a GHP. Due to the anodisation, the maximum enhancement in heat transfer coefficient at the evaporator is 39 % for a 90° inclination at a heat flux of 11 kW/m2. The reported performance enhancement of a GHP may be due to the large numbers of nucleation sites created by the anodisation process and enhancement in the capillary force due to the coating.

  10. Influence of pavement condition on horizontal curve safety.

    Science.gov (United States)

    Buddhavarapu, Prasad; Banerjee, Ambarish; Prozzi, Jorge A

    2013-03-01

    Crash statistics suggest that horizontal curves are the most vulnerable sites for crash occurrence. These crashes are often severe and many involve at least some level of injury due to the nature of the collisions. Ensuring the desired pavement surface condition is one potentially effective strategy to reduce the occurrence of severe accidents on horizontal curves. This study sought to develop crash injury severity models by integrating crash and pavement surface condition databases. It focuses on developing a causal relationship between pavement condition indices and severity level of crashes occurring on two-lane horizontal curves in Texas. In addition, it examines the suitability of the existing Skid Index for safety maintenance of two-lane curves. Significant correlation is evident between pavement condition and crash injury severity on two-lane undivided horizontal curves in Texas. Probability of a crash becoming fatal is appreciably sensitive to certain pavement indices. Data suggested that road facilities providing a smoother and more comfortable ride are vulnerable to severe crashes on horizontal curves. In addition, the study found that longitudinal skid measurement barely correlates with injury severity of crashes occurring on curved portions. The study recommends exploring the option of incorporating lateral friction measurement into Pavement Management System (PMS) databases specifically at curved road segments. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Pavement Response to Variable Tyre Pressure of Heavy Vehicles

    Directory of Open Access Journals (Sweden)

    Arshad Ahmad Kamil

    2016-01-01

    Full Text Available In recent years, the effect of overinflated tyre pressure and increased heavy vehicles’ axle load on flexible pavements has become a subject of great concern because of the higher stress levels induced and damage caused to road pavements. This paper aims to evaluate the effect of variable tyre inflation pressures (using actual tyre contact/footprint area to determine the responses of flexible pavement. A full scale experiment was conducted on a heavy vehicle with 1:1:2 axle configuration, 10 R 20 tyre size and attached trailer with constant axle load. Measurements were made for actual tyre-pavement contact area. KENPAVE linear elastic program was then used to analyse the effects of the measured actual tyre-pavement contact area and the results was compared using conventional circular tyre contact area. A comparative analysis was then made between the actual contact area and the conventional circular tyre contact area. It was found that high tyre inflation pressure produce smaller contact area, giving more detrimental effect on the flexible pavement. It was also found that the temperature of tyres when the heavy vehicles are operational give less significant impact on tyre inflation pressure for the Malaysian climate.

  12. Effect of speed hump characteristics on pavement condition

    Directory of Open Access Journals (Sweden)

    Talaat Ali Abdel-Wahed

    2017-02-01

    Full Text Available Speed humps are the most common type of traffic calming devices due to their low cost and easy installation. However, in many Egyptian roads, considerable number of these humps is randomly placed without proper engineering studies and justifications. Deterioration of pavement condition is observed near these humps. This paper presents a case study applied to collect and analyze visual inspection data for the reason of evaluating the impact of speed humps on pavement condition on intercity rural roads. The paper used 52 speed humps located in an intercity two-lane, two-way road that connects two cities, Tahta and Gerga, in Upper Egypt. The total length of this road is about 34 km. Pavement condition index (PCI, in road sections, near speed humps in the two directions of travel were calculated from the visual inspection measurements. The characteristics of each speed hump (width, height, and distance from preceding hump were measured. Using statistical analyses, the correlations between the pavement conditions and hump characteristics were examined. Regression analysis models were developed to represent the relationships between pavement conditions and hump characteristics. Generally, the results proved that the pavement conditions are greatly influenced by the presence of speed humps and hump characteristics.

  13. Analysis of natural stone block pavements in urban shared areas

    Directory of Open Access Journals (Sweden)

    Pablo Zoccali

    2018-06-01

    Full Text Available This paper analysed and verified an existing block stone pavement in an urban shared area. Fatigue and rutting verification was performed respectively for bound and unbound pavement materials using analytical curves available in the literature. The commercial finite element (FE software Abaqus® was used to calculate the response of the pavement when subjected to different loading, construction and geometrical configurations (i.e. type of analysis, shape and size of meshes, boundary conditions, and bonding contacts between the pavements layers. At the end of this study, a static model of a structure with hexahedral blocks having sides of 0.02 m, with full bonded layers and restrained horizontal displacements on the model sides, was implemented to evaluate the maximum tensile stress induced in a block when the load is applied at its centre. This analysis highlighted the need for rigorous criteria for a correct design, in order to avoid inappropriate and expensive use of road materials. Keywords: Block pavement, Commercial vehicle loads, Finite element model, Hexagonal Stone block, Pedestrian pavement, Shared area

  14. Urban pavement surface temperature. Comparison of numerical and statistical approach

    Science.gov (United States)

    Marchetti, Mario; Khalifa, Abderrahmen; Bues, Michel; Bouilloud, Ludovic; Martin, Eric; Chancibaut, Katia

    2015-04-01

    The forecast of pavement surface temperature is very specific in the context of urban winter maintenance. to manage snow plowing and salting of roads. Such forecast mainly relies on numerical models based on a description of the energy balance between the atmosphere, the buildings and the pavement, with a canyon configuration. Nevertheless, there is a specific need in the physical description and the numerical implementation of the traffic in the energy flux balance. This traffic was originally considered as a constant. Many changes were performed in a numerical model to describe as accurately as possible the traffic effects on this urban energy balance, such as tires friction, pavement-air exchange coefficient, and infrared flux neat balance. Some experiments based on infrared thermography and radiometry were then conducted to quantify the effect fo traffic on urban pavement surface. Based on meteorological data, corresponding pavement temperature forecast were calculated and were compared with fiels measurements. Results indicated a good agreement between the forecast from the numerical model based on this energy balance approach. A complementary forecast approach based on principal component analysis (PCA) and partial least-square regression (PLS) was also developed, with data from thermal mapping usng infrared radiometry. The forecast of pavement surface temperature with air temperature was obtained in the specific case of urban configurtation, and considering traffic into measurements used for the statistical analysis. A comparison between results from the numerical model based on energy balance, and PCA/PLS was then conducted, indicating the advantages and limits of each approach.

  15. Cloud Impacts on Pavement Temperature in Energy Balance Models

    Science.gov (United States)

    Walker, C. L.

    2013-12-01

    Forecast systems provide decision support for end-users ranging from the solar energy industry to municipalities concerned with road safety. Pavement temperature is an important variable when considering vehicle response to various weather conditions. A complex, yet direct relationship exists between tire and pavement temperatures. Literature has shown that as tire temperature increases, friction decreases which affects vehicle performance. Many forecast systems suffer from inaccurate radiation forecasts resulting in part from the inability to model different types of clouds and their influence on radiation. This research focused on forecast improvement by determining how cloud type impacts the amount of shortwave radiation reaching the surface and subsequent pavement temperatures. The study region was the Great Plains where surface solar radiation data were obtained from the High Plains Regional Climate Center's Automated Weather Data Network stations. Road pavement temperature data were obtained from the Meteorological Assimilation Data Ingest System. Cloud properties and radiative transfer quantities were obtained from the Clouds and Earth's Radiant Energy System mission via Aqua and Terra Moderate Resolution Imaging Spectroradiometer satellite products. An additional cloud data set was incorporated from the Naval Research Laboratory Cloud Classification algorithm. Statistical analyses using a modified nearest neighbor approach were first performed relating shortwave radiation variability with road pavement temperature fluctuations. Then statistical associations were determined between the shortwave radiation and cloud property data sets. Preliminary results suggest that substantial pavement forecasting improvement is possible with the inclusion of cloud-specific information. Future model sensitivity testing seeks to quantify the magnitude of forecast improvement.

  16. Improve the quality and service life of water-based pavement marking paints on pavements with high-iron aggregates.

    Science.gov (United States)

    2015-08-01

    White pavement paint marking on airport runways was being discolored by rust-like staining. Discoloration is a critical safety : problem because white paint indicates runways and yellow paint is used for taxiways and aircraft parking. When the white ...

  17. Evaluation and Development of Pavement Scores, Performance Models and Needs Estimates for the TXDOT Pavement Management Information System : Final Report

    Science.gov (United States)

    2012-10-01

    This project conducted a thorough review of the existing Pavement Management Information System (PMIS) database, : performance models, needs estimates, utility curves, and scores calculations, as well as a review of District practices : concerning th...

  18. Establishing appropriate inputs when using the mechanistic-empirical pavement design guide to design rigid pavements in Pennsylvania.

    Science.gov (United States)

    2011-03-01

    Each design input in the Mechanistic-Empirical Design Guide (MEPDG) required for the design of Jointed Plain Concrete : Pavements (JPCPs) is introduced and discussed in this report. Best values for Pennsylvania conditions were established and : recom...

  19. 0-6683 : develop a pavement project evaluation index to support the 4-year pavement management plan.

    Science.gov (United States)

    2013-08-01

    A pavement management plan (PMP) identifies : candidate maintenance and rehabilitation (M&R) : projects for a particular roadway network over a : multi-year planning period. The PMP is a living : document because projects are reevaluated and : reprio...

  20. Feasibility of perpetual pavement stage construction in China: A life cycle cost analysis

    Directory of Open Access Journals (Sweden)

    Zhongyin Guo

    2016-12-01

    Full Text Available The main objective of pavement design and management is to build sustainable pavement structure with minimum costs during its whole life. There are many uncertainties in the process of pavement design pertaining many of its variables, such as future traffic estimation, long time behavior of materials, future weights and types of traveling vehicles, availability of funds etc. Therefore, it is important to apply pavement stage construction technique during the process of pavement design and management to minimize the risk associated with these uncertainties. From the beginning of 2000, the research and application of perpetual asphalt pavement (PP technology has been deployed in China. The semi rigid base for asphalt pavement has been normally considered as typical component of high class highways in the design according to the Chinese experience since 1997. The research objective is to apply pavement stage construction for the evaluation of life cycle costs of Chinese perpetual and traditional semi rigid pavements using operational pavement management system in addition to examine its suitability for design and construction of more economical and durable flexible pavements. It has been found that the stage construction of asphalt layers in PP over semi rigid pavement foundation will create more sustainable and trusted pavement structures in spite of 2–5% increase in present total cost.

  1. Palatal radicular groove: Clinical implications of early diagnosis and surgical sealing

    Directory of Open Access Journals (Sweden)

    P Corrêa-Faria

    2011-01-01

    Full Text Available Palatal radicular groove is a discreet alteration in tooth morphology, characterized by an invagination that begins near the cingulum of the tooth and moves in an apical direction. Clinically, palatal radicular groove may be associated with periodontal and/or endodontic problems. This paper describes a clinical case of a young patient with palatal radicular groove with no signs of periodontal disease or endodontic impairment. An early diagnosis was made and treatment consisted of surgical sealing of the defect. After a 2-year period, reexaminations demonstrated adequate hygiene, maintenance of tooth vitality and periodontal health. The early diagnosis and sealing of the groove observed surgically made the root surface smooth, avoiding subgingival bacterial plaque buildup, and preventing possible periodontal and/or pulp impairment stemming from the defect.

  2. Tunable THz notch filter with a single groove inside parallel-plate waveguides.

    Science.gov (United States)

    Lee, Eui Su; Jeon, Tae-In

    2012-12-31

    A single groove in a parallel-plate waveguide (PPWG) has been applied to a tunable terahertz (THz) notch filter with a transverse-electromagnetic (TEM) mode. When the air gap between the metal plates of the PPWG is controlled from 60 to 240 μm using a motor controlled translation stage or a piezo-actuator, the resonant frequency of the notch filter is changed from 1.75 up to 0.62 THz, respectively. Therefore, the measured tunable sensitivity of the notch filter increases to 6.28 GHz/μm. The measured resonant frequencies were found to be in good agreement with the calculation using an effective groove depth. Using a finite-difference time-domain (FDTD) simulation, we also demonstrate that the sensitivity of a THz microfluidic sensor can be increased via a small air gap, a narrow groove width, and a deep groove depth.

  3. Grooving of grain boundaries in multicrystalline silicon: Effect on solar cell performance

    International Nuclear Information System (INIS)

    Dimassi, W.; Bouaicha, M.; Nouri, H.; Boujmil, M.F.; Ben Nasrallah, S.; Bessais, B.

    2006-01-01

    In this work, we investigate the effect of grooving of grain boundaries (GB) in multicrystalline silicon using chemical etching in HF/HNO 3 solutions. The grain boundaries were grooved in order to reduce the area of these highly recombining regions. Using optimized conditions, grooved GBs enable deep phosphorus diffusion and deep metallic contacts. As a result, the internal quantum efficiency (IQE), and the I-V characteristics under the dark and AM1.5 illumination were improved. It was also observed a reduction of the GB recombination velocity, which was deduced from light-beam-induced-current (LBIC) measurements. Such grooving in multicrystalline silicon enables passivation of GB-related defects. These results are discussed and compared to solar cells based on untreated multicrystalline silicon wafers

  4. Groove Pancreatitis with Biliary and Duodenal Stricture: An Unusual Cause of Obstructive Jaundice

    Directory of Open Access Journals (Sweden)

    Marta Gravito-Soares

    2016-05-01

    Discussion: Groove pancreatitis is a benign cause of obstructive jaundice, whose main differential diagnosis is duodenal or pancreatic neoplasia. When this condition causes duodenal or biliary stricture, surgical treatment can be necessary.

  5. Standardized performance tests of collectors of solar thermal energy: Prototype moderately concentrating grooved collectors

    Science.gov (United States)

    1976-01-01

    Prototypes of moderately concentrating grooved collectors were tested with a solar simulator for varying inlet temperature, flux level, and incident angle. Collector performance is correlated in terms of inlet temperature and flux level.

  6. 'Tongue-and-groove' effect in intensity modulated radiotherapy with static multileaf collimator fields

    International Nuclear Information System (INIS)

    Que, W; Kung, J; Dai, J

    2004-01-01

    The 'tongue-and-groove problem' in step-and-shoot delivery of intensity modulated radiotherapy is investigated. A 'tongue-and-groove' index (TGI) is introduced to quantify the 'tongue-and-groove' effect in step-and-shoot delivery. Four different types of leaf sequencing methods are compared. The sliding window method and the reducing level method use the same number of field segments to deliver the same intensity map, but the TGI is much less for the reducing level method. The leaf synchronization method of Van Santvoort and Heijmen fails in step-and-shoot delivery, but a new method inspired by the method of Van Santvoort and Heijmen is shown to eliminate 'tongue-and-groove' underdosage completely

  7. U-shaped micro-groove fiber based on femtosecond laser processing for humidity sensing

    Science.gov (United States)

    Fu, Gui; Ma, Li-li; Su, Fu-fang; Shi, Meng

    2018-05-01

    A novel optical fiber sensor with a U-shaped micro-groove structure ablated by femtosecond laser on single-mode fiber for measuring air relative humidity (RH) is reported in this paper. In order to improve the accuracy of sensor, a graphene oxide (GO)/polyvinyl alcohol (PVA) composite film is coated on the surface of micro-groove structure. In the U-shaped micro-groove structure, the remaining core and micro-cavity in the micro-groove make up two major optical propagation paths, forming a Mach-Zehnder interferometer (MZI). The sensor has a good linear response within the RH range of 30%—85%, and the maximum sensitivity can reach 0.638 1 nm/%RH. The effect of temperature on the overall performance of the humidity sensor is also investigated. As a new type of all-fiber device, the sensor shows excellent sensitivity and stability.

  8. Determinig the Shape Coefficient A of Groove on the Pen for the Shaft

    Science.gov (United States)

    Křístek, Ivo; Havlík, Jiří; Mosler, Václav; Daniš, Igor

    2017-12-01

    This article focuses on creating a diagram for determining the shape coefficient α for a tongue groove on the shaft. Experimental determination of curve diagrams by comparing diagrams and monograms used using FEM calculations.

  9. Use of lime cement stabilized pavement construction

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M.A.; Raju, G.V.R.P. [JNTU College of Engineering, Kakinada (India). Dept. of Civil Engineering

    2009-08-15

    Expansive clay is a major source of heave induced structural distress. Swelling of expansive soils causes serious problems and produce damages to many structures. Many research organizations are doing extensive work on waste materials concerning the feasibility and environmental suitability. Fly ash, a waste by product from coal burning in thermal power stations, is abundant in India causing severe health, environmental and disposal problems. Attempts are made to investigate the stabilization process with model test tracks over expansive subgrade in flexible pavements. Cyclic plate load tests are carried out on the tracks with chemicals like lime and cement introduced in fly ash subbase laid on sand and expansive subgrades. Test results show that maximum load carrying capacity is obtained for stabilized fly ash subbase compared to untreated fly ash subbase.

  10. Latex improvement of recycled asphalt pavement

    Science.gov (United States)

    Drennon, C.

    1982-08-01

    The performance of a single unmodified milled recycled asphalt concrete was compared to milled asphalt concrete modified by addition of three types of rubber latex. Latex was added at 2, 3, 5, and 8 percent latex by weight of asphalt in the asphalt concrete. Lattices used were a styrene butadiene (SBR), a natural rubber (NR), an acrylonitrile butadiene (NBR), and four varieties of out of specification SBR lattices. Marshall tests, while indecisive, showed a modest improvement in properties of SBR and NR added material at 3 and 5 percent latex. Addition of NBR latex caused deterioration in Marshall stability and flow over that of control. Repeated load tests were run using the indirect tensile test, analyzed by the VESYS program, which computes life of pavements. Repeated load tests showed improvement in asphalt concrete life when 3 and 5 percent SBR was added. Improvement was also shown by the out of specification SBR.

  11. Large eddy simulation of the subcritical flow over a V grooved circular cylinder

    International Nuclear Information System (INIS)

    Alonzo-García, A.; Gutiérrez-Torres, C. del C.; Jiménez-Bernal, J.A.

    2015-01-01

    Highlights: • We compared numerically the turbulent flow over a smooth circular cylinder and a V grooved cylinder in the subcritical regime. • Turbulence intensities in both streamwise and normal direction suffered attenuations. • The swirls structures on grooves peaks seemed to have a cyclic behavior. • The evolution of the flow inside grooves showed that swirls structures located in peaks suffered elongations in the normal direction. • The secondary vortex structures formed in the grooved cylinder near wake were smaller in comparison of the smooth cylinder flow. - Abstract: In this paper, a comparative numerical study of the subcritical flow over a smooth cylinder and a cylinder with V grooves (Re = 140,000) is presented. The implemented technique was the Large Eddy Simulation (LES), which according to Kolmogorov's theory, resolves directly the most energetic largest eddies and models the smallest and considered universal high frequency ones. The Navier-Stokes (N-S) equations were solved using the commercial software ANSYS FLUENT V.12.1, which applied the finite volume method (FVM) to discretize these equations in their unsteady and incompressible forms. The grid densities were 2.6 million cells and 13.5 million cells for the smooth and V grooved cylinder, respectively. Both meshes were composed of structured hexahedral cells and close to the wall of the cylinders, additional refinements were employed in order to obtain y +<5 values. All cases were simulated during at least 15 vortex shedding cycles with the aim of obtaining significant statistical data. Results: showed that for both cases (smooth and V grooved cylinder flow), the numerical code was capable of reproducing the most important physical quantities of the subcritical regime. Velocity distribution and turbulence intensity in the flow direction suffered a slight attenuation along the wake, as a consequence of grooves perturbation, which also caused an increase in the pressure coefficient

  12. Schwann cell interactions with polymer films are affected by groove geometry and film hydrophilicity

    International Nuclear Information System (INIS)

    Mobasseri, S A; Downes, S; Terenghi, G

    2014-01-01

    We have developed a biodegradable polymer scaffold made of a polycaprolactone/polylactic acid (PCL/PLA) film. Surface properties such as topography and chemistry have a vital influence on cell–material interactions. Surface modifications of PCL/PLA films were performed using topographical cues and UV–ozone treatment to improve Schwann cell organisation and behaviour. Schwann cell attachment, alignment and proliferation were evaluated on the grooved UV–ozone treated and non-treated films. Solvent casting of the polymer solution on patterned silicon substrates resulted in films with different groove shapes: V (V), sloped (SL) and square (SQ) shapes. Pitted films, with no grooves, were prepared as a negative control. The UV–ozone treatment was performed to increase hydrophilicity. The process specifications for UV–ozone treatment were evaluated and 5 min radiation time and 6 cm distance to the UV source were suggested as the optimal practise. When cultured on grooved films, Schwann cells elongated on the V and SL shape grooves without crossing over, and grew in the direction of the grooves. However, there was less elongation with more crossing over on the SQ shape grooves. The maximum cell length (511 μm) was observed on the treated V-grooved films. The cells cultured on pitted UV–ozone treated surfaces showed random arrangements with no increase in length. We have demonstrated that the synergic effects of physical cues combined with UV–ozone treatment have the potential to enhance Schwann cell morphology and alignment. (paper)

  13. Management of endodontic-periodontic lesion of a maxillary lateral incisor with palatoradicular groove

    OpenAIRE

    Jayshree Ramakrishna Vishwas; Shoeb Yakub Shaikh; Varsha H. Tambe; Fareedi Mukram Ali; Mohammed Mustafa

    2014-01-01

    Presence of palatal radicular grooves are considered to be an important contributing factor to the development of localized periodontitis, as it favored the accumulation and proliferation of bacterial plaque deep into the periodontium. Pulp involvement could result due to the introduction of bacterial toxins through channels that existed between the root canal system and the groove. Early diagnosis, elimination of inflammation and correction of anatomic complications are the key to a favorabl...

  14. Optimal Tempo for Groove: Its Relation to Directions of Body Movement and Japanese nori.

    Science.gov (United States)

    Etani, Takahide; Marui, Atsushi; Kawase, Satoshi; Keller, Peter E

    2018-01-01

    The tendency for groove-based music to induce body movements has been linked to multiple acoustical factors. However, it is unclear how or whether tempo affects groove, although tempo significantly affects other aspects of music perception. To address this issue, the present study investigated effects of tempo, specific rhythmic organizations of patterns, and syncopation on groove and the induction of the sensation of wanting to move. We focused on the directions of body movement in particular by taking into account nori , which is an indigenous Japanese musical term used not only synonymously with groove, but also as a spatial metaphor indicating vertical or horizontal movement directions. Thus, the present study explored how groove was felt and defined, as well as how musical factors induced the sensation of wanting to move in cross-cultural context. A listening experiment was conducted using drum breaks as stimuli. Stimuli consisted of various rhythm patterns at six tempi from 60 to 200 BPM. The main findings are that: (1) an optimal tempo for groove existed for drum breaks at around 100-120 BPM, (2) an optimal tempo existed for the sensation of wanting to move the body in specific directions (i.e., back-and-forth and side-to-side), (3) groove and nori shared a similar concept of wanting to move but differed on several points (i.e., association with sense of pulse and fast tempo). Overall, the present study suggests that there is an optimal tempo for body movement related to groove. This finding has implications for the use of music or rhythmic stimuli to induce smooth motion in rehabilitation, therapy, or dance.

  15. Effect of heat treatment on the grooving corrosion resistance of ERW pipes

    International Nuclear Information System (INIS)

    Lee, Jong Kwon; Lee, Jae Young; Lim, Soo Hyun; Park, Ji Hwan; Seo, Bo Min; Kim, Seon Hwa

    2002-01-01

    The v-sharp grooving corrosion of ERW(electrical resistance welding) steel pipes limited their wide application in the industry in spite of their high productivity and efficiency. The grooving corrosion is caused mainly by the different microstructures between the matrix and weld that is formed during the rapid heating and cooling cycle in welding. By this localized corrosion reaction of pipes, it evolves economic problems such as the early damage of industrial facilities and pipe lines of apartment, and water pollution. Even though the diminishing of sulfur content is most effective to decrease the susceptibility of grooving corrosion, it requires costly process. In this study, improvement of grooving corrosion resistance was pursuited by post weld heat treatment in the temperature range between 650 .deg. C and 950 .deg. C. Also, the effect of heat input in the welding was investigated. By employing chromnoamperometry and potentiodynamic experiment, the corrosion rate and grooving corrosion index(α) were obtained. It was found that heat treatment could improve the grooving corrosion resistance. Among them, the heat treated at 900 .deg. C and 950 .deg. C had excellent grooving corrosion resistance. The index of heat treated specimen at 900 .deg. C and 950 .deg. C were 1.0, 1.2, respectively, which are almost immune to the grooving corrosion. Potential difference after the heat treatment, between base and weld metal was decreased considerably. While the as-received one measured 61∼71 mV, that of the 900 .deg. C heat treated steel pipe measured only 10mV. The results were explained and discussed

  16. Optimal Tempo for Groove: Its Relation to Directions of Body Movement and Japanese nori

    Directory of Open Access Journals (Sweden)

    Takahide Etani

    2018-04-01

    Full Text Available The tendency for groove-based music to induce body movements has been linked to multiple acoustical factors. However, it is unclear how or whether tempo affects groove, although tempo significantly affects other aspects of music perception. To address this issue, the present study investigated effects of tempo, specific rhythmic organizations of patterns, and syncopation on groove and the induction of the sensation of wanting to move. We focused on the directions of body movement in particular by taking into account nori, which is an indigenous Japanese musical term used not only synonymously with groove, but also as a spatial metaphor indicating vertical or horizontal movement directions. Thus, the present study explored how groove was felt and defined, as well as how musical factors induced the sensation of wanting to move in cross-cultural context. A listening experiment was conducted using drum breaks as stimuli. Stimuli consisted of various rhythm patterns at six tempi from 60 to 200 BPM. The main findings are that: (1 an optimal tempo for groove existed for drum breaks at around 100–120 BPM, (2 an optimal tempo existed for the sensation of wanting to move the body in specific directions (i.e., back-and-forth and side-to-side, (3 groove and nori shared a similar concept of wanting to move but differed on several points (i.e., association with sense of pulse and fast tempo. Overall, the present study suggests that there is an optimal tempo for body movement related to groove. This finding has implications for the use of music or rhythmic stimuli to induce smooth motion in rehabilitation, therapy, or dance.

  17. Grooved surface topography alters matrix-metalloproteinase production by human fibroblasts

    International Nuclear Information System (INIS)

    Brydone, Alistair S; Dominic Meek, R M; Dalby, Matthew J; Berry, Catherine C; McNamara, Laura E

    2011-01-01

    Extracellular matrix (ECM) remodelling is an essential physiological process in which matrix-metalloproteinases (MMPs) have a key role. Manipulating the manner in which cells produce MMPs and ECMs may enable the creation of a desired tissue type, i.e. effect repair, or the prevention of tissue invasion (e.g. metastasis). The aim of this project was to determine if culturing fibroblasts on grooved topography altered collagen deposition or MMP production. Human fibroblasts were seeded on planar or grooved polycaprolactone substrates (grooves were 12.5 μm wide with varying depths of 240 nm, 540 nm or 2300 nm). Cell behaviour and collagen production were studied using fluorescence microscopy and the spent culture medium was assessed using gel zymography to detect MMPs. Total collagen deposition was high on the 240 nm deep grooves, but decreased as the groove depth increased, i.e. as cell contact guidance decreased. There was an increase in gelatinase on the 2300 nm deep grooved topography and there was a difference in the temporal expression of MMP-3 observed on the planar surface compared to the 540 nm and 2300 nm topographies. These results show that topography can alter collagen and MMP production. A fuller understanding of these processes may permit the design of surfaces tailored to tissue regeneration e.g. tendon repair.

  18. Cold test of deep groove plarizer for 170 GHz ECCD system

    International Nuclear Information System (INIS)

    Saigusa, M.; Ookouti, K.; Sazawa, S.; Yuasa, S.; Takei, N.; Takahashi, K.; Sakamoto, K.; Imai, T.

    2001-01-01

    The single deep groove mirror was proposed as a new concept polarizer instead of the conventional two mirror polarizers for producing ordinary (or extraordinary) wave with high mode purity at an arbitrary injection angle in electron cyclotron current drive (ECCD) experiments. The estimated mode purity of O and X waves on the plasma surface is expected to be higher than about 93% for reasonable ECCD experimental conditions. The three types of deep groove mirrors, which are the rectangular groove mirror and the non-rectangular one, are manufactured and tested at the frequency range from 140 GHz to 170 GHz and the power level of 30 mW. The groove parameters are the period of 0.9-1 mm, the ridge width of 0.45-0.5 mm, and the groove depth of 1.98 mm, which is deeper than a wavelength at 170 GHz. The measured results of deep groove polarizers agree with the theoretical predictions, qualitatively. Those prove the feasibility of a single mirror polarizer for ECCD system

  19. V-groove SnO2 nanowire sensors: fabrication and Pt-nanoparticle decoration

    International Nuclear Information System (INIS)

    Sun, Gun-Joo; Choi, Sun-Woo; Jung, Sung-Hyun; Katoch, Akash; Kim, Sang Sub

    2013-01-01

    Networked SnO 2 nanowire sensors were achieved using the selective growth of SnO 2 nanowires and their tangling ability, particularly on on-chip V-groove structures, in an effort to overcome the disadvantages imposed on the conventional trench-structured SnO 2 nanowire sensors. The sensing performance of the V-groove-structured SnO 2 nanowire sensors was highly dependent on the geometrical dimension of the groove, being superior to those of their conventional trench-structured counterparts. Pt nanoparticles were decorated on the surface of the networked SnO 2 nanowires via γ-ray radiolysis to enhance the sensing performances of the V-groove sensors whose V-groove widths had been optimized. The V-groove-structured Pt-nanoparticle-decorated SnO 2 nanowire sensors exhibited outstanding and reliable sensing capabilities towards toluene and nitrogen dioxide gases, indicating their potential for use as a platform for chemical gas sensors. (paper)

  20. Structure of a Pheromone Receptor-Associated Mhc Molecule With An Open And Empty Groove

    Energy Technology Data Exchange (ETDEWEB)

    Olson, R.; Huey-Tubman, K.E.; Dulac, C.; Bjorkman, P.J.; /Caltech /Harvard U.

    2006-10-06

    Neurons in the murine vomeronasal organ (VNO) express a family of class Ib major histocompatibility complex (MHC) proteins (M10s) that interact with the V2R class of VNO receptors. This interaction may play a direct role in the detection of pheromonal cues that initiate reproductive and territorial behaviors. The crystal structure of M10.5, an M10 family member, is similar to that of classical MHC molecules. However, the M10.5 counterpart of the MHC peptide-binding groove is open and unoccupied, revealing the first structure of an empty class I MHC molecule. Similar to empty MHC molecules, but unlike peptide-filled MHC proteins and non-peptide-binding MHC homologs, M10.5 is thermally unstable, suggesting that its groove is normally occupied. However, M10.5 does not bind endogenous peptides when expressed in mammalian cells or when offered a mixture of class I-binding peptides. The F pocket side of the M10.5 groove is open, suggesting that ligands larger than 8-10-mer class I-binding peptides could fit by extending out of the groove. Moreover, variable residues point up from the groove helices, rather than toward the groove as in classical MHC structures. These data suggest that M10s are unlikely to provide specific recognition of class I MHC-binding peptides, but are consistent with binding to other ligands, including proteins such as the V2Rs.

  1. Structure of a pheromone receptor-associated MHC molecule with an open and empty groove.

    Directory of Open Access Journals (Sweden)

    2005-08-01

    Full Text Available Neurons in the murine vomeronasal organ (VNO express a family of class Ib major histocompatibility complex (MHC proteins (M10s that interact with the V2R class of VNO receptors. This interaction may play a direct role in the detection of pheromonal cues that initiate reproductive and territorial behaviors. The crystal structure of M10.5, an M10 family member, is similar to that of classical MHC molecules. However, the M10.5 counterpart of the MHC peptide-binding groove is open and unoccupied, revealing the first structure of an empty class I MHC molecule. Similar to empty MHC molecules, but unlike peptide-filled MHC proteins and non-peptide-binding MHC homologs, M10.5 is thermally unstable, suggesting that its groove is normally occupied. However, M10.5 does not bind endogenous peptides when expressed in mammalian cells or when offered a mixture of class I-binding peptides. The F pocket side of the M10.5 groove is open, suggesting that ligands larger than 8-10-mer class I-binding peptides could fit by extending out of the groove. Moreover, variable residues point up from the groove helices, rather than toward the groove as in classical MHC structures. These data suggest that M10s are unlikely to provide specific recognition of class I MHC-binding peptides, but are consistent with binding to other ligands, including proteins such as the V2Rs.

  2. Grooved surface topography alters matrix-metalloproteinase production by human fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Brydone, Alistair S; Dominic Meek, R M [Department of Orthopaedics, Southern General Hospital, 1345 Govan Road, Glasgow G51 4TF (United Kingdom); Dalby, Matthew J; Berry, Catherine C; McNamara, Laura E, E-mail: alibrydone@gmail.com [Centre for Cell Engineering, Joseph Black Building, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2011-06-15

    Extracellular matrix (ECM) remodelling is an essential physiological process in which matrix-metalloproteinases (MMPs) have a key role. Manipulating the manner in which cells produce MMPs and ECMs may enable the creation of a desired tissue type, i.e. effect repair, or the prevention of tissue invasion (e.g. metastasis). The aim of this project was to determine if culturing fibroblasts on grooved topography altered collagen deposition or MMP production. Human fibroblasts were seeded on planar or grooved polycaprolactone substrates (grooves were 12.5 {mu}m wide with varying depths of 240 nm, 540 nm or 2300 nm). Cell behaviour and collagen production were studied using fluorescence microscopy and the spent culture medium was assessed using gel zymography to detect MMPs. Total collagen deposition was high on the 240 nm deep grooves, but decreased as the groove depth increased, i.e. as cell contact guidance decreased. There was an increase in gelatinase on the 2300 nm deep grooved topography and there was a difference in the temporal expression of MMP-3 observed on the planar surface compared to the 540 nm and 2300 nm topographies. These results show that topography can alter collagen and MMP production. A fuller understanding of these processes may permit the design of surfaces tailored to tissue regeneration e.g. tendon repair.

  3. Modified Kelvin Equations for Capillary Condensation in Narrow and Wide Grooves

    Science.gov (United States)

    Malijevský, Alexandr; Parry, Andrew O.

    2018-03-01

    We consider the location and order of capillary condensation transitions occurring in deep grooves of width L and depth D . For walls that are completely wet by liquid (contact angle θ =0 ) the transition is continuous and its location is not sensitive to the depth of the groove. However, for walls that are partially wet by liquid, where the transition is first order, we show that the pressure at which it occurs is determined by a modified Kelvin equation characterized by an edge contact angle θE describing the shape of the meniscus formed at the top of the groove. The dependence of θE on the groove depth D relies, in turn, on whether corner menisci are formed at the bottom of the groove in the low density gaslike phase. While for macroscopically wide grooves these are always present when θ condensation transition is different depending on whether the contact angle is greater or less than a universal value θ*≈31 °. Our arguments are supported by detailed microscopic density functional theory calculations that show that the modified Kelvin equation remains highly accurate even when L and D are of the order of tens of molecular diameters.

  4. NMR studies of DNA oligomers and their interactions with minor groove binding ligands

    Energy Technology Data Exchange (ETDEWEB)

    Fagan, Patricia A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1996-05-01

    The cationic peptide ligands distamycin and netropsin bind noncovalently to the minor groove of DNA. The binding site, orientation, stoichiometry, and qualitative affinity of distamycin binding to several short DNA oligomers were investigated by NMR spectroscopy. The oligomers studied contain A,T-rich or I,C-rich binding sites, where I = 2-desaminodeoxyguanosine. I•C base pairs are functional analogs of A•T base pairs in the minor groove. The different behaviors exhibited by distamycin and netropsin binding to various DNA sequences suggested that these ligands are sensitive probes of DNA structure. For sites of five or more base pairs, distamycin can form 1:1 or 2:1 ligand:DNA complexes. Cooperativity in distamycin binding is low in sites such as AAAAA which has narrow minor grooves, and is higher in sites with wider minor grooves such as ATATAT. The distamycin binding and base pair opening lifetimes of I,C-containing DNA oligomers suggest that the I,C minor groove is structurally different from the A,T minor groove. Molecules which direct chemistry to a specific DNA sequence could be used as antiviral compounds, diagnostic probes, or molecular biology tools. The author studied two ligands in which reactive groups were tethered to a distamycin to increase the sequence specificity of the reactive agent.

  5. Measurement of sheath thickness by lining out grooves in the Hall-type stationary plasma thrusters

    International Nuclear Information System (INIS)

    Yu Daren; Wu Zhiwen; Ning Zhongxi; Wang Xiaogang

    2007-01-01

    Using grooves created along the axial direction of the discharge channel, a method for measuring sheath thickness in Hall-type stationary plasma thrusters has been developed. By distorting the wall surface using these grooves, it is possible to numerically study the effect of the wall surface on the sheath and near wall conductivity. Monte Carlo method is applied to calculate the electron temperature variation with different groove depths. The electron dynamic process in the plasma is described by a test particle method with the electron randomly entering the sheath from the discharge channel and being reflected back. Numerical results show that the reflected electron temperature is hardly affected by the wall surface if the groove depth is much less than the sheath thickness. On the other hand, the reflected electron temperature increases if the groove depth is much greater than the sheath thickness. The reflected electron temperature has a sharp jump when the depth of groove is on the order of the sheath thickness. The simulation is repeated with different sheath thicknesses and the results are the same. Therefore, a diagnosis mean of the sheath thickness can be developed based on the method. Also the simulation results are in accord with the experimental data. Besides, the measurement method may be applicable to other plasma device with similar orthogonal steady state electrical and magnetic fields

  6. Cycle time improvement for plastic injection moulding process by sub groove modification in conformal cooling channel

    Science.gov (United States)

    Kamarudin, K.; Wahab, M. S.; Batcha, M. F. M.; Shayfull, Z.; Raus, A. A.; Ahmed, Aqeel

    2017-09-01

    Mould designers have been struggling for the improvement of the cooling system performance, despite the fact that the cooling system complexity is physically limited by the fabrication capability of the conventional tooling methods. However, the growth of Solid Free Form Technology (SFF) allow the mould designer to develop more than just a regular conformal cooling channel. Numerous researchers demonstrate that conformal cooling channel was tremendously given significant result in the improvement of productivity and quality in the plastic injection moulding process. This paper presents the research work that applies the passive enhancement method in square shape cooling channel to enhance the efficiency of cooling performance by adding the sub groove to the cooling channel itself. Previous design that uses square shape cooling channel was improved by adding various numbers of sub groove to meet the best sub groove design that able reduced the cooling time. The effect of sub groove design on cooling time was investigated by Autodesk Modlflow Insight software. The simulation results showed that the various sub groove designs give different values to ejection time. The Design 7 showed the lowest value of ejection time with 24.3% increment. The addition of sub groove significantly increased a coolant velocity and a rate of heat transfer from molten plastic to coolant.

  7. Standard nomenclature and methods for describing the condition of pavements draft TRH 6

    CSIR Research Space (South Africa)

    Curtayne, PC

    2009-01-26

    Full Text Available The need for describing the condition of pavements occurs frequently in highway engineering. Accurate descriptions are a prerequisite for establishing procedures with which to evaluate the various aspects of the pavement condition. A variety...

  8. Update to Permeable Pavement Research at the Edison Environmental Center - abstract

    Science.gov (United States)

    Abstract The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavement including: interlocking concrete permeable pavers...

  9. Development of Pavement Performance Prediction Models for Preservation Treatments : Volume 2

    Science.gov (United States)

    2018-04-01

    The implementation of a pavement preservation program was initiated in Fiscal Year (FY) 2005 at the Illinois Department of Transportation (IDOT) by appropriating funding for four specific pavement preservation treatments. The types of treatments incl...

  10. Update to permeable pavement research at the Edison Environmental Center - slides

    Science.gov (United States)

    Abstract: The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavement including: interlocking concrete permeable paver...

  11. Historical performance evaluation of Iowa pavement treatments using data analytics : tech transfer summary.

    Science.gov (United States)

    2017-01-01

    Evaluate the performance of the most-used pavement treatments in Iowa by considering different parameters such as type of treatment, treatment thickness, traffic, and pavement type : Estimate a service life for each treatment based on the obs...

  12. Modeling of interaction between steel and concrete in continuously reinforced concrete pavements : final report.

    Science.gov (United States)

    2016-01-01

    Continuously reinforced concrete pavement (CRCP) contains continuous longitudinal reinforcement with no transverse : expansion within the early life of the pavement and can continue to develop cracks in the long-term. The : accurate modeling of CRCPs...

  13. Top-down cracking of rigid pavements constructed with fast setting hydraulic cement concrete

    CSIR Research Space (South Africa)

    Heath, AC

    2009-01-29

    Full Text Available Jointed plain concrete pavement (JPCP) test sections were constructed using fast setting hydrualic cement concrete (FSHCC) as part of the California accelerated pavement testing program (CAL/APT). Many of the longer slabs cracked under environmental...

  14. Assessment of asphalt concrete reinforcement grid in flexible pavements : final report.

    Science.gov (United States)

    2016-05-01

    This report investigated the application of accepted methods of pavement structural evaluation to independently assess the potential structural benefit of asphalt geogrid reinforcement of an operational flexible highway pavement. The asphalt interlay...

  15. Nontraditional Fog Seal for Asphalt Pavement : Performance on Shoulder Sections in Minnesota

    Science.gov (United States)

    2018-05-01

    The pavement engineering community has recently been introduced to a number of nontraditional products intended for uses as surface sealers for bituminous pavements. Many new products use agricultural-based components and little is known regarding th...

  16. Determination of coefficient of thermal expansion effects on Louisiana's PCC pavement design : technical summary report.

    Science.gov (United States)

    2011-12-01

    The coefficient of thermal expansion (CTE) has been widely considered as a fundamental property of : Portland cement concrete (PCC) pavement but has never played an important role in the thickness design : procedure for PCC pavement until recently. I...

  17. Caltrans accelerated pavement testing (CAL/APT) program - test results: 1993-1996

    CSIR Research Space (South Africa)

    Nokes, WA

    1997-08-01

    Full Text Available By combining the results of both the HVS and laboratory tests, interpretations of pavement performance are described and recommendations for pavement design and construction have been made to Caltrans....

  18. Engineering properties of stabilized subgrade soils for implementation of the AASHTO 2002 pavement design guide.

    Science.gov (United States)

    2009-06-01

    A comprehensive laboratory study was undertaken to determine engineering properties of cementitiously stabilized common subgrade soils in Oklahoma for the design of roadway pavements in accordance with the AASHTO 2002 Mechanistic-Empirical Pavement D...

  19. MDOT innovation leading to faster, longer-lasting pavement repairs : research spotlight.

    Science.gov (United States)

    2015-01-01

    Current methods of patching pavement must evolve to meet increasing mobility demands. : To address this need, MDOT has been testing a new generation of rapid set full-depth : pavement repair materials. Initial results are promising. The new materials...

  20. Historical performance evaluation of Iowa pavement treatments using data analytics : final report.

    Science.gov (United States)

    2016-11-01

    The pavement network in Iowa has reached a mature state making maintenance and rehabilitation activities more important than new construction. As such, a need exists to evaluate the performance of the pavement treatments and estimate their performanc...

  1. Recycled Portland cement concrete pavements : Part II, state-of-the art summary.

    Science.gov (United States)

    1979-01-01

    This report constitutes a review of the literature concerning recycling of portland cement concrete pavements by crushing the old pavement and reusing the crushed material as aggregate in a number of applications. A summary of the major projects cond...

  2. Texas flexible pavements and overlays : calibration plans for M-E models and related software.

    Science.gov (United States)

    2013-06-01

    This five-year project was initiated to collect materials and pavement performance data on a minimum of 100 highway test sections around the State of Texas, incorporating flexible pavements and overlays. Besides being used to calibrate and validate m...

  3. Transition from manual to automatic rutting measurements : effect on pavement serviceability index values.

    Science.gov (United States)

    2010-06-01

    The Pavement Serviceability Index (pSn is used by New Mexico Department of Transportation : (NMDOT) to express the serviceability level of a pavement section at the network level. The PSI : is calculated with distress ratings (including rutting) and ...

  4. Commonwealth of Pennsylvania Bureau of Aviation pavement evaluation report : final report, March 2010.

    Science.gov (United States)

    2010-03-01

    As part of the Pennsylvania Department of Transportations (PennDOT) airport pavement management efforts, the Bureau of : Aviation (BOA) retained Applied Pavement Technology, Inc. (APTech), assisted by DY Consultants, to evaluate the condition of t...

  5. Simulation of dynamic traffic loading based on accelerated pavement testing (APT)

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2004-03-01

    Full Text Available The objective of this paper is to introduce the latest Heavy Vehicle Simulator (HVS) technology as part of the South African Accelerated Pavement Testing (APT) efforts, its capabilities and expected impact on road pavement analysis....

  6. Accelerated pavement testing of low-volume paved roads with geocell reinforcement : [technical summary].

    Science.gov (United States)

    2015-03-01

    The Midwest States Accelerated Pavement Testing Pooled-Fund Program, financed : by the highway departments of Kansas, Iowa, Missouri, and New York, has : supported an accelerated pavement testing (APT) project to study the rehabilitation : of low-vol...

  7. Accelerated testing for studying pavement design and performance (FY 2003) : research summary.

    Science.gov (United States)

    2008-01-01

    The Midwest States Accelerated Pavement Testing Pooled Fund Program, financed by : the highway departments of Missouri, Iowa, Kansas and Nebraska, has supported an : accelerated pavement testing (APT) project to compare the performance of stabilized ...

  8. Accelerated pavement testing of low-volume paved roads with geocell reinforcement.

    Science.gov (United States)

    2015-03-01

    The Midwest States Accelerated Pavement Testing Pooled-Fund Program, financed by the highway : departments of Kansas, Iowa, Missouri, and New York, has supported an accelerated pavement testing (APT) project : to study the rehabilitation of low-volum...

  9. Evaluation of concrete pavements with materials-related distress : appendix B.

    Science.gov (United States)

    2010-02-02

    An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

  10. Considerations for rigid vs. flexible pavement designs when allowed as alternate bids : technical report.

    Science.gov (United States)

    2009-08-01

    This report documents the research conducted for the Texas Department of Transportation (TxDOT) : concerning the use of pavement alternates. The scope of the project includes reviewing the state-of-thepractice : in methods used for pavement type sele...

  11. Nondestructive pavement evaluation using finite element analysis based soft computing models.

    Science.gov (United States)

    2009-09-15

    Evaluating structural condition of existing, in-service pavements constitutes annually a major part of the : maintenance and rehabilitation activities undertaken by State Highway Agencies (SHAs). Accurate : estimation of pavement geometry and layer m...

  12. Alternate bidding strategies for asphalt and concrete pavement projects utilizing life cycle cost analysis (LCCA).

    Science.gov (United States)

    2012-07-01

    Recent changes in pavement materials costs have impacted the competitive environment relative to the : determination of the most cost effective pavement structure for a specific highway project. In response, State : highway agencies have renewed thei...

  13. A methodology to support the development of 4-year pavement management plan.

    Science.gov (United States)

    2014-07-01

    A methodology for forming and prioritizing pavement maintenance and rehabilitation (M&R) projects was developed. : The Texas Department of Transportation (TxDOT) can use this methodology to generate defensible and cost-effective : 4-year pavement man...

  14. Evaluation of concrete pavements with materials-related distress : appendix C.

    Science.gov (United States)

    2010-03-02

    An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

  15. Preservation of olfaction in surgery of olfactory groove meningiomas.

    Science.gov (United States)

    Jang, Woo-Youl; Jung, Shin; Jung, Tae-Young; Moon, Kyung-Sub; Kim, In-Young

    2013-08-01

    Olfaction is commonly considered as secondary among the sensory functions, perhaps reflecting a lack of interest in sparing olfaction after surgery for the olfactory groove meningiomas (OGM). However, considering the repercussions of olfaction for the quality of life, the assessment of post-operative olfaction should be necessary. We retrospectively reviewed the olfactory outcome in patients with OGM and investigated the factors associated with sparing the post-operative olfaction. Between 1993 and 2012, 40 patients with OGM underwent surgical resection and estimated the olfactory function using the Korean version of "Sniffin'Sticks" test (KVSS). Variable factors, such as tumor size, degree of preoperative edema, tumor consistency, preoperative olfactory function, surgical approaches, patient's age, and gender were analyzed with attention to the post-operative olfactory function. Anatomical and functional preservation of olfactory structures were achieved in 26 patients (65%) and 22 patients (55%), respectively. Among the variable factors, size of tumor was significant related to the preservation of post-operative olfaction. (78.6% in size4 cm, p=0.035). Sparing the olfaction was significantly better in patients without preoperative olfactory dysfunction (84.6%) compared with ones with preoperative olfactory dysfunction (40.7%, p=0.016). The frontolateral approach achieved much more excellent post-operative olfactory function (71.4%) than the bifrontal approach (36.8%, p=0.032). If the tumor was smaller than 4 cm and the patients did not present olfactory dysfunction preoperatively, the possibility of sparing the post-operative olfaction was high. Among the variable surgical approaches, frontolateral route may be preferable sparing the post-operative olfaction. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Clinical, radiological, surgical, and pathological determinants of olfactory groove schwannoma

    Directory of Open Access Journals (Sweden)

    Andi Sadayandi Ramesh

    2014-01-01

    Full Text Available Background: Olfactory groove schwannomas (OGS are rare anterior cranial fossa base tumors with only 41 cases reported in literature. Olfactory ensheathing cell schwannoma (OECS has similar clinico-radiological features as OGS, but a different cell of origin. In recent years, there is growing interest in OECS as more cases are being reported. Aims: The objective was to study the clinico-radiological features of OGS and define the histological differentiation from OECS. Materials and Methods: We retrospectively analyzed clinical, radiological, surgical and histopathological picture of all cases of OGS managed in our institute. Immuno histochemical studies were performed in these tumors for differentiating from OECS. A comprehensive review of articles published until date describing the operative treatment was done. Results: All three cases had presented with seizures, two had anosmia and papilledema. Gross-total resection was achieved in all our patients. One patient expired in the postoperative period due to septicemia. Positive expression to newer immuno histochemical biomarker CD57 (Leu7, with negative staining to smooth muscle α-actin (SMA was helpful in confirming the diagnosis of OGS and differentiating it from OECS in all our cases. Conclusions: OECS, though rare has to be differentiated from OGS using immuno histochemistry. Gross-total resection of OGS with preservation of olfactory function is often possible and curative. Although these tumors are commonly treated with microsurgical skull base approaches, an endoscopic endonasal approach can be considered in some cases, with repair using mucoperiosteal pedicled flap to prevent cerebrospinal fluid leak.

  17. Comparative Study of Flexible Pavement Designs for New Road in Great Britain and Indonesia

    OpenAIRE

    Basri, Hanafi

    2009-01-01

    The objective of this article is to compare the design methods for flexible pavements for new roads and overlays between two countries, Great Britain and Indonesia.Pavement design procedures provide a structure that can be accepted in a specific environmental condition and able to satisfy the anticipated traffic loading. There are many factors influencing the thickness design of pavement, such as pavement materials, traffic load and climatic conditions, there is no doubt that the method of pa...

  18. Using a constructive pavement texture index for skid resistance screening

    Directory of Open Access Journals (Sweden)

    Chia-Pei Chou

    2017-07-01

    Full Text Available Skid resistance measurement is one of the major measurements used to assess road safety. Typical devices used for measuring skid resistance include single point checking type and continuous measurements type. However, conducting periodic full roadway network skid resistance survey can be a relatively time consuming and difficult task because of the limited water carrying capacity used by all kinds of devices, including the continuous types. On the contrary, measurement of pavement surface texture can be conducted easily and continuously by most profilers. This research investigates the relation between pavement skid resistance and surface texture. The focus is on the development of a texture index that can serve as a screening indicator to filter out the high-risk pavement sections for further skid resistance measurement. Two measuring devices, GripTester (GT and National Taiwan University laser profiler (NTU Profiler, were used to collect data on pavement skid resistance and texture in a network of 555 sections, respectively. The pavement texture index of the mean difference of elevation (MDE is calculated at a 1 mm profile interval, which is a very promising indicator to represent pavement skid resistance. Through a sensitivity study, the MDE threshold of 0.15 mm is observed to provide a relatively reasonable screening function that filters out 29.01% of the entire surveyed network for further skid resistance inspection. It averted more than 70% skid resistance measurement capacity of the entire network. The accuracy of correct judgment by the selected threshold is about 80%, only 3.78% of roadway sections considered for further inspection of the recommended list are not included. Keywords: Skid resistance, Pavement texture, Macrotexture, Laser profiler, GripTester

  19. Temperature prediction model of asphalt pavement in cold regions based on an improved BP neural network

    International Nuclear Information System (INIS)

    Xu, Bo; Dan, Han-Cheng; Li, Liang

    2017-01-01

    Highlights: • Pavement temperature prediction model is presented with improved BP neural network. • Dynamic and static methods are presented to predict pavement temperature. • Pavement temperature can be excellently predicted in next 3 h. - Abstract: Ice cover on pavement threatens traffic safety, and pavement temperature is the main factor used to determine whether the wet pavement is icy or not. In this paper, a temperature prediction model of the pavement in winter is established by introducing an improved Back Propagation (BP) neural network model. Before the application of the BP neural network model, many efforts were made to eliminate chaos and determine the regularity of temperature on the pavement surface (e.g., analyze the regularity of diurnal and monthly variations of pavement temperature). New dynamic and static prediction methods are presented by improving the algorithms to intelligently overcome the prediction inaccuracy at the change point of daily temperature. Furthermore, some scenarios have been compared for different dates and road sections to verify the reliability of the prediction model. According to the analysis results, the daily pavement temperatures can be accurately predicted for the next 3 h from the time of prediction by combining the dynamic and static prediction methods. The presented method in this paper can provide technical references for temperature prediction of the pavement and the development of an early-warning system for icy pavements in cold regions.

  20. Integrating Pavement Crack Detection and Analysis Using Autonomous Unmanned Aerial Vehicle Imagery

    Science.gov (United States)

    2015-03-27

    INTEGRATING PAVEMENT CRACK DETECTION AND ANALYSIS USING AUTONOMOUS UNMANNED AERIAL VEHICLE...protection in the United States. AFIT-ENV-MS-15-M-195 INTEGRATING PAVEMENT CRACK DETECTION AND ANALYSIS USING AUTONOMOUS UNMANNED AERIAL...APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENV-MS-15-M-195 INTEGRATING PAVEMENT CRACK DETECTION AND ANALYSIS USING AUTONOMOUS

  1. Prediction of IRI in short and long terms for flexible pavements: ANN and GMDH methods

    NARCIS (Netherlands)

    Ziari, H.; Sobhani, J.; Ayoubinejad, J.; Hartmann, Timo

    2015-01-01

    Prediction of pavement condition is one of the most important issues in pavement management systems. In this paper, capabilities of artificial neural networks (ANNs) and group method of data handling (GMDH) methods in predicting flexible pavement conditions were analysed in three levels: in 1 year,

  2. Effects of moving dynamic tyre loads on tyre-pavement contact stresses

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2002-01-01

    Full Text Available The purpose of this paper is to indicate the effect that moving dynamic tyre loads has on the tyre-pavement contact stresses used in pavement analysis. Traditionally tyre loads (in pavement analysis) are modelled as constant loads applied through...

  3. Toward using tire-road contact stresses in pavement design and analysis

    CSIR Research Space (South Africa)

    De Beer, Morris

    2012-10-01

    Full Text Available pavement design. Four different tire models were used to represent a single tire type in order to demonstrate its effect on road pavement response of a typical South African pavement structure. Only applied vertical stress was used for the analyses...

  4. Evaluation of the MIT-Scan-T2 for non-destructive PCC pavement thickness determination.

    Science.gov (United States)

    2008-07-01

    The MIT-Scan-T2 device is marketed as a non-destructive way to determine pavement thickness on both : HMA and PCC pavements. PCC pavement thickness determination is an important incentivedisincentive : measurement for the Iowa DOT and contractors. Th...

  5. Evaluation of MIT-SCAN-T2 for Thickness Quality Control for PCC and HMA Pavements

    Science.gov (United States)

    2018-02-01

    Thickness is currently a pay item for PCC pavements and a quality control item for both PCC and HMA pavements. A change in pavement thickness of 0.5 in. can result in a change of multiple years of service. Current thickness measurements are performed...

  6. Application of the portable pavement seismic analyser (PSPA) for pavement analysis

    CSIR Research Space (South Africa)

    Steyn, WJVDM

    2007-07-01

    Full Text Available at the selected locations were compared using a one-way ANOVA and a correlation matrix to analyse the repeatability of the PSPA data, and to determine whether there was a significant difference between the three observations obtained at a specific location... behaviour from pavement layers, the PSPA measurements were conducted at 90° angles at the same location. An ANOVA test and correlation matrix was set up for each point to evaluate the isotropy of the moduli. Unfortunately, no comparative data (such as FWD...

  7. Stormwater quality of spring-summer-fall effluent from three partial-infiltration permeable pavement systems and conventional asphalt pavement.

    Science.gov (United States)

    Drake, Jennifer; Bradford, Andrea; Van Seters, Tim

    2014-06-15

    This study examined the spring, summer and fall water quality performance of three partial-infiltration permeable pavement (PP) systems and a conventional asphalt pavement in Ontario. The study, conducted between 2010 and 2012, compared the water quality of effluent from two Interlocking Permeable Concrete Pavements (AquaPave(®) and Eco-Optiloc(®)) and a Hydromedia(®) Pervious Concrete pavement with runoff from an Asphalt control pavement. The usage of permeable pavements can mitigate the impact of urbanization on receiving surface water systems through quantity control and stormwater treatment. The PP systems provided excellent stormwater treatment for petroleum hydrocarbons, total suspended solids, metals (copper, iron, manganese and zinc) and nutrients (total-nitrogen and total-phosphorus) by reducing event mean concentrations (EMC) as well as total pollutant loadings. The PPs significantly reduced the concentration and loading of ammonia (NH4(+)+NH3), nitrite (NO2(-)) and organic-nitrogen (Org-N) but increased the concentration and loading of nitrate (NO3(-)). The PP systems had mixed performances for the treatment of phosphate (PO4(3-)). The PP systems increased the concentration of sodium (Na) and chloride (Cl) but EMCs remained well below recommended levels for drinking water quality. Relative to the observed runoff, winter road salt was released more slowly from the PP systems resulting in elevated spring and early-summer Cl and Na concentrations in effluent. PP materials were found to introduce dissolved solids into the infiltrating stormwater. The release of these pollutants was verified by additional laboratory scale testing of the individual pavement and aggregate materials at the University of Guelph. Pollutant concentrations were greatest during the first few months after construction and declined rapidly over the course of the study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. The impact of postoperative supraclavicular radiotherapy on tracheoesophageal groove lymph node metastasis in esophageal carcinoma

    International Nuclear Information System (INIS)

    Qian Pudong; Lu Jinchen; Mei Zeru; Zhu Jun

    2005-01-01

    Objective: To evaluate the prognostic factors of tracheoesophageal groove lymph node (TEGLN) metastasis in postoperative esophageal carcinoma. Methods: From January 1996 to December 1997, 101 postoperative cervical and thoracic esophageal carcinoma patients proved absence from tracheoesophageal groove lymph node (TEGIAN) metastasis before and after operation by physical examination and computer tomography examination were entered into this study. The patients were divided into three groups according to the treatment of supraclavicular region: no prophylactic radiotherapy (group A-, 30 patients); prophylactic radiotherapy with local dose < 45 Gy (Group B-, 71 patients); and prophylactic radiotherapy with local dose ≥45 Gy (Group C-, 19 patients). Radiotherapy was delivered by cobalt- 60 or 6 MV X-ray with the prescribed dose normalized to the point of tracheoesophageal groove, i. e, 5 cm in depth. The tracheoesophageal groove lymph node metastasis after treatment was observed. Results: The incidence of tracheoesophageal groove lymph node metastasis was 20% (6/30), 9.6% (5/71) and 0% (0/19) in groups A, B and C. Univariate analysis showed that there was significant difference of TEGLN metastasis between groups A and C only (P=0.039), but higher dose to supraclavicular region tended to lower the incidence of TEGLN metastasis. Multivariate analysis showed that only prophylactic radiotherapy to the supraclavicular region was independent prognostic factor for TEGLN metastasis (P=0.037). Gender, primary tumor site and pathological stage had no significant impact on TEGLN metastasis. Conclusions: Postoperative prophylactic supraclavicular region irradiation can lower the incidence of tracheoesophageal groove lymph node metastasis in esophageal carcinoma. Radiotherapy dose should not be less than 45 Gy and should be routinely normalized to a point 5 cm deep in the tracheoesophageal groove. (authors)

  9. Coal-tar based pavement sealant toxicity to freshwater macroinvertebrates

    International Nuclear Information System (INIS)

    Bryer, Pamela J.; Scoggins, Mateo; McClintock, Nancy L.

    2010-01-01

    Non-point-source pollution is a major source of ecological impairment in urban stream systems. Recent work suggests that coal-tar pavement sealants, used extensively to protect parking areas, may be contributing a large portion of the polycyclic aromatic hydrocarbon (PAH) loading seen in urban stream sediments. The hypothesis that dried coal-tar pavement sealant flake could alter the macroinvertebrate communities native to streams in Austin, TX was tested using a controlled outdoor laboratory type approach. The treatment groups were: control, low, medium, and high with total PAH concentrations (TPAH = sum of 16 EPA priority pollutant PAHs) of 0.1, 7.5, 18.4, and 300 mg/kg respectively. The low, medium, and high treatments were created via the addition of dried coal-tar pavement sealant to a sterile soil. At the start of the 24-day exposure, sediment from a minimally impacted local reference site containing a community of live sediment-dwelling benthic macroinvertebrates was added to each replicate. An exposure-dependent response was found for several stream health measures and for several individual taxa. There were community differences in abundance (P = 0.0004) and richness (P < 0.0001) between treatments in addition to specific taxa responses, displaying a clear negative relationship with the amount of coal-tar sealant flake. These results support the hypothesis that coal-tar pavement sealants contain bioavailable PAHs that may harm aquatic environments. - Coal-tar pavement sealants degrade stream invertebrate communities.

  10. Update to Permeable Pavement Research at the Edison ...

    Science.gov (United States)

    The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavements including interlocking concrete permeable pavers, pervious concrete, and porous asphalt. The permeable pavements are limited to parking spaces while adjacent driving lanes are impermeable and drain to the permeable surfaces. The parking lot is instrumented for continuous monitoring with thermistors and water content reflectometers that measure moisture as infiltrate passes through the storage gallery beneath the permeable pavements into the underlying native soil. Each permeable surface of the parking lot has four lined sections that capture infiltrate in tanks for water quality analyses; these tanks are capable of holding volumes up to 4.1 m3, which represents up to 38 mm (1.5 in.) for direct rainfall on the porous pavement and runoff from adjacent driving lanes that drain into the permeable surface.Previous technical releases concerning the demonstration site focused on monitoring techniques, observed chloride and nutrient concentrations, surface hydrology, and infiltration and evaporation rates. This presentation summarizes these past findings and addresses current water quality efforts including pH, solids analysis, total organic carbon, and chemical oxygen demand. Stormwater runoff continues to be a major cause of water pollution in

  11. A User Friendly Software for Rigid Pavement Design

    Directory of Open Access Journals (Sweden)

    Aydın Kıcı

    2017-12-01

    Full Text Available Concrete pavements as concrete road slab, appear as a strong alternative for flexible superstructures especially because of their low cost for maintenance and repair and the high performance they show under heavy axle loads. The design of these concrete road slabs is quite different from the traditional concrete and reinforced concrete structures’ design. In the design for this kind of pavements, traffic conditions should be defined properly and considered an addition to the concrete and platform properties. There have been designing methods developed based on both experimental and mechanic foundations for concrete pavements. The most important ones of these methods are AASHTO (1993 and PCA (1984. In both design methods, it’s significant to know the maximum deflections and maximum strains the vehicles’ loads cause on the pavement. The calculation of this maximum deflections and maximum strains can be done via the finite element method or the closed formulas which have been developed by Westergaard. In this study, a user-friendly software has been developed based on AASHTO 1993, PCA 1984 design methods and Westergaard formulas. Thanks to this software, the user who wants to design the concrete pavement as concrete road slab can obtain the essential parameters automatically by entering the required data for the design.

  12. Perpetual pavement – absorbing stress and functional maintenance

    Directory of Open Access Journals (Sweden)

    Rong Gao

    2017-03-01

    Full Text Available Perpetual Pavement combines the well documented smoothness and safety advantages of asphalt with an advanced, multi-layer paving design process, that with routine maintenance, extends the useful life of a roadway. Perpetual provides long lasting road and smoothness for the construction purposes. This study has the design key points of perpetual pavement based on the idea of life cycle, which has a new direction for the new highway construction, reconstruction and expansion. First, the structure of long life pavement design is studied to analyze the effect of stress absorbing layer. Second, researches on stress absorbing layer from the aspects of raw materials, mix proportion are implemented. Third, the design index of stress absorbing layer is determined by the shear strength test. The results show that the design idea of composite perpetual pavement can be realized by reasonable design of the stress absorbing layer and carrying out the surface functional maintenance can ensure the pavement to avoid structural damage in the operation stage.

  13. Urban evaporation rates for water-permeable pavements.

    Science.gov (United States)

    Starke, P; Göbel, P; Coldewey, W G

    2010-01-01

    In urban areas the natural water balance is disturbed. Infiltration and evaporation are reduced, resulting in a high surface runoff and a typical city climate, which can lead to floods and damages. Water-permeable pavements have a high infiltration rate that reduces surface runoff by increasing the groundwater recharge. The high water retention capacity of the street body of up to 51 l/m(2) and its connection via pores to the surface lead to higher evaporation rates than impermeable surfaces. A comparison of these two kinds of pavements shows a 16% increase in evaporation levels of water-permeable pavements. Furthermore, the evaporation from impermeable pavements is linked directly to rain events due to fast-drying surfaces. Water-permeable pavements show a more evenly distributed evaporation after a rain event. Cooling effects by evaporative heat loss can improve the city climate even several days after rain events. On a large scale use, uncomfortable weather like sultriness or dry heat can be prevented and the urban water balance can be attenuated towards the natural.

  14. Experimental Study on Color Durability of Color Asphalt Pavement

    Science.gov (United States)

    Ning, Shi; Huan, Su

    2017-06-01

    Aiming at the poor Color durability and the lack of research on Color asphalt pavement, spraying an anti-tire trace seal resin emulsion on the surface, a Color durable asphalt pavement was proposed. After long-term rolling and long-term aging test, the Color durability was evaluated by RGB function in Photoshop and trace residue rate formula. Test results proved that the Evaluation method was simple and effective. After long-term rolling, the Color of the road surface tends to a constant value. Spraying the emulsion on the road surface can resist tire traces. After long-term aging test, the resistance to tire traces was increased by 26.6% compared with the conventional type, while the former was 44.1% higher than the latter without long-term aging. The Color durable asphalt pavement can effectively improve the ability of Color asphalt pavement to resist tire traces, and significantly improve the Color durability of Color asphalt pavement.

  15. Automatic Pavement Crack Recognition Based on BP Neural Network

    Directory of Open Access Journals (Sweden)

    Li Li

    2014-02-01

    Full Text Available A feasible pavement crack detection system plays an important role in evaluating the road condition and providing the necessary road maintenance. In this paper, a back propagation neural network (BPNN is used to recognize pavement cracks from images. To improve the recognition accuracy of the BPNN, a complete framework of image processing is proposed including image preprocessing and crack information extraction. In this framework, the redundant image information is reduced as much as possible and two sets of feature parameters are constructed to classify the crack images. Then a BPNN is adopted to distinguish pavement images between linear and alligator cracks to acquire high recognition accuracy. Besides, the linear cracks can be further classified into transversal and longitudinal cracks according to the direction angle. Finally, the proposed method is evaluated on the data of 400 pavement images obtained by the Automatic Road Analyzer (ARAN in Northern China and the results show that the proposed method seems to be a powerful tool for pavement crack recognition. The rates of correct classification for alligator, transversal and longitudinal cracks are 97.5%, 100% and 88.0%, respectively. Compared to some previous studies, the method proposed in this paper is effective for all three kinds of cracks and the results are also acceptable for engineering application.

  16. What musicians do to induce the sensation of groove in simple and complex melodies, and how listeners perceive it

    Directory of Open Access Journals (Sweden)

    Guy eMadison

    2014-08-01

    Full Text Available Groove is the experience of wanting to move when hearing music, such as snapping fingers or tapping feet. This is a central aspect of much music, in particular of music intended for dancing. While previous research has found considerable consistency in ratings of groove across individuals, it remains unclear how groove is induced, that is, what are the physical properties of the acoustic signal that differ between more and less groove-inducing versions. Here, we examined this issue with a performance experiment, in which 4 musicians performed 6 simple and 6 complex melodies in two conditions with the intention of minimizing and maximizing groove. Analyses of rhythmical and temporal properties from the performances demonstrated some general effects. For example, more groove was associated with more notes on faster metrical levels and syncopation, and less groove was associated with deadpan timing and destruction of the regular pulse. We did not observe that deviations from the metrical grid (i.e. micro-timing were a predictor of groove. A listener experiment confirmed that the musicians’ manipulations had the intended effects on the experience of groove. A Brunswikian lens model was applied, which estimates the performer-perceiver communication across the two experiments. It showed that the communication achievement for simple melodies was 0.62, and that the matching of performers’ and listeners’ use of 9 rhythmical cues was 0.83. For complex melodies with an already high level of groove, the corresponding values were 0.39 and 0.34, showing that it was much more difficult to take out groove from musical structures designed to induce groove.

  17. Developing Pavement Distress Deterioration Models for Pavement Management System Using Markovian Probabilistic Process

    Directory of Open Access Journals (Sweden)

    Promothes Saha

    2017-01-01

    Full Text Available In the state of Colorado, the Colorado Department of Transportation (CDOT utilizes their pavement management system (PMS to manage approximately 9,100 miles of interstate, highways, and low-volume roads. Three types of deterioration models are currently being used in the existing PMS: site-specific, family, and expert opinion curves. These curves are developed using deterministic techniques. In the deterministic technique, the uncertainties of pavement deterioration related to traffic and weather are not considered. Probabilistic models that take into account the uncertainties result in more accurate curves. In this study, probabilistic models using the discrete-time Markov process were developed for five distress indices: transverse, longitudinal, fatigue, rut, and ride indices, as a case study on low-volume roads. Regression techniques were used to develop the deterioration paths using the predicted distribution of indices estimated from the Markov process. Results indicated that longitudinal, fatigue, and rut indices had very slow deterioration over time, whereas transverse and ride indices showed faster deterioration. The developed deterioration models had the coefficient of determination (R2 above 0.84. As probabilistic models provide more accurate results, it is recommended that these models be used as the family curves in the CDOT PMS for low-volume roads.

  18. Geo synthetic-reinforced Pavement systems; Sistemas de pavimentos reforzados con geosinteticos

    Energy Technology Data Exchange (ETDEWEB)

    Zornberg, J. G.

    2014-02-01

    Geo synthetics have been used as reinforcement inclusions to improve pavement performance. while there are clear field evidence of the benefit of using geo synthetic reinforcements, the specific conditions or mechanisms that govern the reinforcement of pavements are, at best, unclear and have remained largely unmeasured. Significant research has been recently conducted with the objectives of: (i) determining the relevant properties of geo synthetics that contribute to the enhanced performance of pavement systems, (ii) developing appropriate analytical, laboratory and field methods capable of quantifying the pavement performance, and (iii) enabling the prediction of pavement performance as a function of the properties of the various types of geo synthetics. (Author)

  19. Factors Influencing Stormwater Mitigation in Permeable Pavement

    Directory of Open Access Journals (Sweden)

    Chun Yan Liu

    2017-12-01

    Full Text Available Permeable pavement (PP is used worldwide to mitigate surface runoff in urban areas. Various studies have examined the factors governing the hydrologic performance of PP. However, relatively little is known about the relative importance of these governing factors and the long-term hydrologic performance of PP. This study applied numerical models—calibrated and validated using existing experimental results—to simulate hundreds of event-based and two long-term rainfall scenarios for two designs of PP. Based on the event-based simulation results, rainfall intensity, rainfall volume, thickness of the storage layer and the hydraulic conductivity of the subgrade were identified as the most influential factors in PP runoff reduction. Over the long term, PP performed significantly better in a relatively drier climate (e.g., New York, reducing nearly 90% of runoff volume compared to 70% in a relatively wetter climate (e.g., Hong Kong. The two designs of PP examined performed differently, and the difference was more apparent in the relatively wetter climate. This study generated insights that will help the design and implementation of PP to mitigate stormwater worldwide.

  20. Transverse grooved artefacts from southwestern Asia and northern Eurasia: Common traits and the reconstruction of function

    Directory of Open Access Journals (Sweden)

    Irina Usacheva

    2016-10-01

    Full Text Available Transverse grooved artefacts (TGA appeared as a new cultural element in Mesolithic-Proto-Neolithic sites in southwestern Asia. We know of similar artefacts from northern Africa. Hundreds of TGA have also been found in northern Eurasia. Some common traits were found in specimens from far apart territories, such as the non-abrasive heat-resistant nature of the raw materials, specificity of fragmentation without any signs of physical impact, the standard size of the grooves, association with a specific type of landscape, the similar economic level of the societies with which the items are associated, and use-wear marks in the grooves. Based on these regularities we can speak of a single main function for these artefacts which support the earlier reconstruction of R.L. and R.S. Solecki, suggesting that grooved stones were used for straightening cane and reed shafts under heating. Other evidence and traces that have been identified on the surface of TGA outside the groove could be associated with a variety of additional functions.

  1. Development of an equine groove model to induce metacarpophalangeal osteoarthritis: a pilot study on 6 horses.

    Science.gov (United States)

    Maninchedda, Ugo; Lepage, Olivier M; Gangl, Monika; Hilairet, Sandrine; Remandet, Bernard; Meot, Francoise; Penarier, Geraldine; Segard, Emilie; Cortez, Pierre; Jorgensen, Christian; Steinberg, Régis

    2015-01-01

    The aim of this work was to develop an equine metacarpophalangeal joint model that induces osteoarthritis that is not primarily mediated by instability or inflammation. The study involved six Standardbred horses. Standardized cartilage surface damage or "grooves" were created arthroscopically on the distal dorsal aspect of the lateral and medial metacarpal condyles of a randomly chosen limb. The contralateral limb was sham operated. After 2 weeks of stall rest, horses were trotted 30 minutes every other day for 8 weeks, then evaluated for lameness and radiographed. Synovial fluid was analyzed for cytology and biomarkers. At 10 weeks post-surgery, horses were euthanized for macroscopic and histologic joint evaluation. Arthroscopic grooving allowed precise and identical damage to the cartilage of all animals. Under the controlled exercise regime, this osteoarthritis groove model displayed significant radiographic, macroscopic, and microscopic degenerative and reactive changes. Histology demonstrated consistent surgically induced grooves limited to non-calcified cartilage and accompanied by secondary adjacent cartilage lesions, chondrocyte necrosis, chondrocyte clusters, cartilage matrix softening, fissuring, mild subchondral bone inflammation, edema, and osteoblastic margination. Synovial fluid biochemistry and cytology demonstrated significantly elevated total protein without an increase in prostaglandin E2, neutrophils, or chondrocytes. This equine metacarpophalangeal groove model demonstrated that standardized non-calcified cartilage damage accompanied by exercise triggered altered osteochondral morphology and cartilage degeneration with minimal or inefficient repair and little inflammatory response. This model, if validated, would allow for assessment of disease processes and the effects of therapy.

  2. Development of an equine groove model to induce metacarpophalangeal osteoarthritis: a pilot study on 6 horses.

    Directory of Open Access Journals (Sweden)

    Ugo Maninchedda

    Full Text Available The aim of this work was to develop an equine metacarpophalangeal joint model that induces osteoarthritis that is not primarily mediated by instability or inflammation. The study involved six Standardbred horses. Standardized cartilage surface damage or "grooves" were created arthroscopically on the distal dorsal aspect of the lateral and medial metacarpal condyles of a randomly chosen limb. The contralateral limb was sham operated. After 2 weeks of stall rest, horses were trotted 30 minutes every other day for 8 weeks, then evaluated for lameness and radiographed. Synovial fluid was analyzed for cytology and biomarkers. At 10 weeks post-surgery, horses were euthanized for macroscopic and histologic joint evaluation. Arthroscopic grooving allowed precise and identical damage to the cartilage of all animals. Under the controlled exercise regime, this osteoarthritis groove model displayed significant radiographic, macroscopic, and microscopic degenerative and reactive changes. Histology demonstrated consistent surgically induced grooves limited to non-calcified cartilage and accompanied by secondary adjacent cartilage lesions, chondrocyte necrosis, chondrocyte clusters, cartilage matrix softening, fissuring, mild subchondral bone inflammation, edema, and osteoblastic margination. Synovial fluid biochemistry and cytology demonstrated significantly elevated total protein without an increase in prostaglandin E2, neutrophils, or chondrocytes. This equine metacarpophalangeal groove model demonstrated that standardized non-calcified cartilage damage accompanied by exercise triggered altered osteochondral morphology and cartilage degeneration with minimal or inefficient repair and little inflammatory response. This model, if validated, would allow for assessment of disease processes and the effects of therapy.

  3. A test for the minimum scale of grooving on the Amatrice and Norcia earthquakes

    Science.gov (United States)

    Okamoto, K.; Brodsky, E. E.; Billi, A.

    2017-12-01

    As stress builds up along a fault, elastic strain energy builds until it cannot be accommodated by small-scale ductile deformation and then the fault brittlely fails. This brittle failure is associated with the grooving process that causes slickensides along fault planes. Therefore the scale at which slickensides disappear could be geological evidence of earthquake nucleation. Past studies found the minimum scale of grooving, however the studied fault surfaces were not exposed by recent earthquakes. These measurements could have been a product of chemical or mechanical weathering. On August 24th and October 30th of 2016, MW 6.0 and 6.5 earthquakes shook central Italy. The earthquakes caused decimeter to meter scale fault scarps along the Mt. Vettoretto Fault. Here, we analyze samples of a scarp using white light interferometry in order to determine if the minimum scale of grooving is present. Results suggest that grooving begins around 100 μm for these samples, which is consistent with previous findings of faults without any direct evidence of earthquakes. The measurement is also consistent with typical values of the frictional weakening distance Dc, which also is associated with a transition between ductile and brittle behavior. The measurements show that the minimum scale of grooving is a useful measure of the behavior of faults.

  4. Thermal performance comparison of oscillating heat pipes with and without helical micro-grooves

    Science.gov (United States)

    Qu, Jian; Li, Xiaojun; Xu, Qian; Wang, Qian

    2017-11-01

    This paper presents an experimental investigation to compare the thermal performance of three closed loop oscillating heat pipes (OHPs) with and without internal helical microgrooves at vertical and horizontal orientations. All of these OHPs were made from copper tubes and have three turns with lengths of 70, 230 and 110 mm at the evaporator, adiabatic and condenser sections, respectively. Deionized water was used as the working fluid at a volumetric filling ratio of 50%. The internal diameters (IDs) of two smooth-tube OHPs are 4.0 and 4.8 mm, respectively, and the internal diameter of micro-grooved OHP without groove structures is about 4.5 mm. Experimental results demonstrated that the addition of groove structures make the OHP remarkably outperform smooth-tube OHPs in both effective thermal conductivity and thermal resistance. The thermal resistance of vertically-oriented micro-grooved OHP could be lowered to 0.057 °C/W associated with an effective thermal conductivity of 6.1 × 104 W/ (m·K) at the input heat flux of 3.8 × 104 W/m2. Compared to smooth-tube OHPs, preliminary mechanism analysis reveals that local heat transfer coefficients both at the heating and cooling sections of micro-grooved OHP could be significantly improved. Moreover, enhanced liquid backflow to the evaporator due to microgroove-induced capillarity is also responsible for the OHP performance enhancement.

  5. Study of mastoid canals and grooves in north karnataka human skulls.

    Science.gov (United States)

    Hadimani, Gavishiddappa Andanappa; Bagoji, Ishwar Basavantappa

    2013-08-01

    This study was undertaken to observe the frequency of mastoid canals and grooves in north Karnataka dry human skulls. 100 dry human skulls of unknown age and sex from the department of Anatomy were selected and observed for the present study. The mastoid regions of dry skulls were observed for the presence of mastoid canals and grooves, if any. A metallic wire was passed through the canal for its confirmation and then the length was measured. The Mastoid canals were present in 53% of the total 100 skulls observed either bilaterally or unilaterally. Mastoid grooves were present in 18% of the total skulls (100) observed. Double mastoid canal was found in 01% of total skull studied and both Mastoid canals & Mastoid grooves together were present in 02% of the total skulls (100) observed. The knowledge of mastoid canals and grooves is very important for otolaryngologists and neurosurgeons. Because they contain an arterial branch of occipital artery with its accompanying vein which is liable to injury resulting into severe bleeding.

  6. Research on fatigue behavior and residual stress of large-scale cruciform welding joint with groove

    International Nuclear Information System (INIS)

    Zhao, Xiaohui; Liu, Yu; Liu, Yong; Gao, Yuan

    2014-01-01

    Highlights: • The fatigue behavior of the large-scale cruciform welding joint with groove was studied. • The longitudinal residual stress of the large-scale cruciform welding joint was tested by contour method. • The fatigue fracture mechanism of the large-scale cruciform welding joint with groove was analyzed. - Abstract: Fatigue fracture behavior of the 30 mm thick Q460C-Z steel cruciform welded joint with groove was investigated. The fatigue test results indicated that fatigue strength of 30 mm thick Q460C-Z steel cruciform welded joint with groove can reach fatigue level of 80 MPa (FAT80). Fatigue crack source of the failure specimen initiated from weld toe. Meanwhile, the microcrack was also found in the fusion zones of the fatigue failure specimen, which was caused by weld quality and weld metal integrity resulting from the multi-pass welds. Two-dimensional map of the longitudinal residual stress of 30 mm thick Q460C-Z steel cruciform welded joint with groove was obtained by using the contour method. The stress nephogram of Two-dimensional map indicated that longitudinal residual stress in the welding center is the largest

  7. Mechanochemical Polarization of Contiguous Cell Walls Shapes Plant Pavement Cells.

    Science.gov (United States)

    Majda, Mateusz; Grones, Peter; Sintorn, Ida-Maria; Vain, Thomas; Milani, Pascale; Krupinski, Pawel; Zagórska-Marek, Beata; Viotti, Corrado; Jönsson, Henrik; Mellerowicz, Ewa J; Hamant, Olivier; Robert, Stéphanie

    2017-11-06

    The epidermis of aerial plant organs is thought to be limiting for growth, because it acts as a continuous load-bearing layer, resisting tension. Leaf epidermis contains jigsaw puzzle piece-shaped pavement cells whose shape has been proposed to be a result of subcellular variations in expansion rate that induce local buckling events. Paradoxically, such local compressive buckling should not occur given the tensile stresses across the epidermis. Using computational modeling, we show that the simplest scenario to explain pavement cell shapes within an epidermis under tension must involve mechanical wall heterogeneities across and along the anticlinal pavement cell walls between adjacent cells. Combining genetics, atomic force microscopy, and immunolabeling, we demonstrate that contiguous cell walls indeed exhibit hybrid mechanochemical properties. Such biochemical wall heterogeneities precede wall bending. Altogether, this provides a possible mechanism for the generation of complex plant cell shapes. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Application of Artificial Intelligence for Optimization in Pavement Management

    Directory of Open Access Journals (Sweden)

    Reus Salini

    2015-07-01

    Full Text Available Artificial intelligence (AI is a group of techniques that have quite a potential to be applied to pavement engineering and management. In this study, we developed a practical, flexible and out of the box approach to apply genetic algorithms to optimizing the budget allocation and the road maintenance strategy selection for a road network. The aim is to provide an alternative to existing software and better fit the requirements of an important number of pavement managers. To meet the objectives, a new indicator, named Road Global Value Index (RGVI, was created to contemplate the pavement condition, the traffic and the economic and political importance for each and every road section. This paper describes the approach and its components by an example confirming that genetic algorithms are very effective for the intended purpose.

  9. Performance of Kaolin Clay on the Concrete Pavement

    Science.gov (United States)

    Abdullah, M. E.; Jaya, R. P.; Shahafuddin, M. N. A.; Yaacob, H.; Ibrahim, M. H. Wan; Nazri, F. M.; Ramli, N. I.; Mohammed, A. A.

    2018-05-01

    This paper investigates the performance of concrete pavement containing kaolin clay with their engineering properties and to determine the optimum kaolin clay content. The concrete used throughout the study was designed as grade 30 MPa strength with constant water to cement ratio of 0.49. The compressive strength, flexural strength and water absorption test was conducted in this research. The concrete mix designed with kaolin clay as cement replacement comprises at 0%, 5%, 10% and 15% by the total weight of cement. The results indicate that the strength of pavement concrete decreases as the percentage of kaolin clay increases. It also shows that the water absorption increases with the percentage of cement replacement. However, 5% kaolin clay is found to be the optimum level to replace cement in a pavement concrete.

  10. Pavement Subgrade Performance Study in the Danish Road Testing Machine

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ertman Larsen, Hans Jørgen

    1997-01-01

    Most existing pavement subgrade criteria are based on the AASHO Road Test, where only one material was tested and for only one climatic condition. To study the validity of these criteria and to refine the criteria a co-operative research program entitled the "International Pavement Subgrade...... Performance Study" was sponsored by the FHWA with American, Finnish and Danish partners. This paper describes the first test series which was carried out in the Danish Road Testing Machine (RTM).The first step in this program is a full scale test on an instrumented pavement in the Danish Road Testing Machine....... Pressure gauges and strain cells were installed in the upper part of the subgrade, for measuring stresses and strains in all three directions. During and after construction FWD testing was carried out to evaluate the elastic parameters of the materials. These parameters were then used with the theory...

  11. Recycling of Reclaimed Asphalt Pavement in Portland Cement Concrete

    Directory of Open Access Journals (Sweden)

    Salim Al-Oraimi

    2009-06-01

    Full Text Available Reclaimed Asphalt Pavement (RAP is the result of removing old asphalt pavement material. RAP consists of high quality well-graded aggregate coated with asphalt cement. The removal of asphalt concrete is done for reconstruction purposes, resurfacing, or to obtain access to buried utilities. The disposal of RAP represents a large loss of valuable source of high quality aggregate. This research investigates the properties of concrete utilizing recycled reclaimed asphalt pavement (RAP. Two control mixes with normal aggregate were designed with water cement ratios of 0.45 and 0.5. The control mixes resulted in compressive strengths of 50 and 33 MPa after 28 days of curing. The coarse fraction of RAP was used to replace the coarse aggregate with 25, 50, 75, and 100% for both mixtures. In addition to the control mix (0%, the mixes containing RAP were evaluated for slump, compressive strength, flexural strength, and modulus of elasticity. Durability was evaluated using surface absorption test.

  12. Determination of Pavement Rehabilitation Activities through a Permutation Algorithm

    Directory of Open Access Journals (Sweden)

    Sangyum Lee

    2013-01-01

    Full Text Available This paper presents a mathematical programming model for optimal pavement rehabilitation planning. The model maximized the rehabilitation area through a newly developed permutation algorithm, based on the procedures outlined in the harmony search (HS algorithm. Additionally, the proposed algorithm was based on an optimal solution method for the problem of multilocation rehabilitation activities on pavement structure, using empirical deterioration and rehabilitation effectiveness models, according to a limited maintenance budget. Thus, nonlinear pavement performance and rehabilitation activity decision models were used to maximize the objective functions of the rehabilitation area within a limited budget, through the permutation algorithm. Our results showed that the heuristic permutation algorithm provided a good optimum in terms of maximizing the rehabilitation area, compared with a method of the worst-first maintenance currently used in Seoul.

  13. Pavement maintenance optimization model using Markov Decision Processes

    Science.gov (United States)

    Mandiartha, P.; Duffield, C. F.; Razelan, I. S. b. M.; Ismail, A. b. H.

    2017-09-01

    This paper presents an optimization model for selection of pavement maintenance intervention using a theory of Markov Decision Processes (MDP). There are some particular characteristics of the MDP developed in this paper which distinguish it from other similar studies or optimization models intended for pavement maintenance policy development. These unique characteristics include a direct inclusion of constraints into the formulation of MDP, the use of an average cost method of MDP, and the policy development process based on the dual linear programming solution. The limited information or discussions that are available on these matters in terms of stochastic based optimization model in road network management motivates this study. This paper uses a data set acquired from road authorities of state of Victoria, Australia, to test the model and recommends steps in the computation of MDP based stochastic optimization model, leading to the development of optimum pavement maintenance policy.

  14. Rheo-mechanical model for self-healing asphalt pavement

    International Nuclear Information System (INIS)

    Gömze, A L; Gömze, L N

    2017-01-01

    Examining the rheological properties of different asphalt mixtures at different temperatures, pressures and deformation conditions on the combined rheo-tribometers the authors have found that the generally used Burgers-model doesn’t explain the deformation properties of asphalt mixtures and pavements under loading forces and loading pressures. To understand better the rheological and deformation properties of such complex materials like asphalt mixtures and pavements the authors used Malvern Mastersizer X laser granulometer, Bruker D8 Advance X-ray diffractometer, Hitachi TM 1000 Scanning Elektronmicroscope, Tristar 3000 specific surface tester and the combined rheo-tribometer developed and patented by the authors. After the complex investigation of different asphalt mixtures the authors have found a new, more complex rheological model for the asphalts including self-healing asphalt pavements. (paper)

  15. Modified asphalt for pavements; Hosoyo kaishitsu asufuaruto ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Tsukagoshi, T. [Nippon Oil Co. Ltd., Yokohama (Japan)

    1997-10-01

    Modified asphalt has been used widely in such applications as countermeasure against rutting, countermeasure against wear caused by tire chains in snowy and cold areas, or bridge deck pavement. Features of various kinds of modified asphalt, standards, and standard properties are introduced. Modified asphalt containing natural asphalt is used for steel plate deck pavement. Semi-blown asphalt is used when emphasis must be given to the countermeasure for flowing resistance of asphalt pavement. Features and standards of asphalt containing rubber, thermoplastic elastomer, and thermoplastic resin are described. Asphalt containing heat-setting resin shows excellent characteristics, which other types of modified asphalt do not possess, in the laboratory resistance test for fatigue, flowing, and wear. Change in the history of modified asphalt in Japan from the initial stage to the present are explained and shown in a table together with time and phenomena, and the change in the production of modified asphalt is shown. 15 refs., 5 figs., 5 tabs.

  16. Pavement system with rubber tire chips in subgrade

    Energy Technology Data Exchange (ETDEWEB)

    Ashtakala, B.; Hoque, A.K.M.M. [Concordia Univ., Montreal, PQ (Canada). Dept. of Civil Engineering

    1995-12-31

    A pavement design method was developed in which shredded rubber tire chips mixed with sand were used as a material for pavement subgrade. Rubber tire chips are highly compressible and produce both elastic and plastic deformations under the application of loads. Sand was added to fill the void between the tire chips and make the mixture a strong material. The design method considered the vertical compressive strain produced by the design life traffic load 18k (80 KN) repetitions. The equivalent thicknesses of the layers above the subgrade corresponding to this vertical compressive strain were determined using contour charts. From this equivalent thickness, the thicknesses for asphalt pavement, base, and sub-base were determined by Odemark`s method. 3 refs., 1 tab., 3 figs.

  17. RAPID INSPECTION OF PAVEMENT MARKINGS USING MOBILE LIDAR POINT CLOUDS

    Directory of Open Access Journals (Sweden)

    H. Zhang

    2016-06-01

    Full Text Available This study aims at building a robust semi-automated pavement marking extraction workflow based on the use of mobile LiDAR point clouds. The proposed workflow consists of three components: preprocessing, extraction, and classification. In preprocessing, the mobile LiDAR point clouds are converted into the radiometrically corrected intensity imagery of the road surface. Then the pavement markings are automatically extracted with the intensity using a set of algorithms, including Otsu’s thresholding, neighbor-counting filtering, and region growing. Finally, the extracted pavement markings are classified with the geometric parameters using a manually defined decision tree. Case studies are conducted using the mobile LiDAR dataset acquired in Xiamen (Fujian, China with different road environments by the RIEGL VMX-450 system. The results demonstrated that the proposed workflow and our software tool can achieve 93% in completeness, 95% in correctness, and 94% in F-score when using Xiamen dataset.

  18. Tactile pavement for guiding walking direction: An assessment of heading direction and gait stability.

    Science.gov (United States)

    Pluijter, Nanda; de Wit, Lieke P W; Bruijn, Sjoerd M; Plaisier, Myrthe A

    2015-10-01

    For maintaining heading direction while walking we heavily rely on vision. Therefore, walking in the absence of vision or with visual attention directed elsewhere potentially leads to dangerous situations. Here we investigated whether tactile information from the feet can be used as a (partial) substitute for vision in maintaining a stable heading direction. If so, participants should be better able to keep a constant heading direction on tactile pavement that indicates directionality than on regular flat pavement. However, such a pavement may also be destabilizing. Thus we asked participants to walk straight ahead on regular pavement, and on tactile pavement (tiles with ridges along the walking direction) while varying the amount of vision. We assessed the effects of the type of pavement as well as the amount of vision on the variability of the heading direction as well as gait stability. Both of these measures were calculated from accelerations and angular velocities recorded from a smartphone attached to the participants trunk. Results showed that on tactile pavement participants had a less variations in their heading direction than on regular pavement. The drawback, however, was that the tactile pavement used in this study decreased gait stability. In sum, tactile pavement can be used as a partial substitute for vision in maintaining heading direction, but it can also decrease gait stability. Future work should focus on designing tactile pavement that does provided directional clues, but is less destabilizing. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Inverse Analysis of Pavement Structural Properties Based on Dynamic Finite Element Modeling and Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Xiaochao Tang

    2013-03-01

    Full Text Available With the movement towards the implementation of mechanistic-empirical pavement design guide (MEPDG, an accurate determination of pavement layer moduli is vital for predicting pavement critical mechanistic responses. A backcalculation procedure is commonly used to estimate the pavement layer moduli based on the non-destructive falling weight deflectometer (FWD tests. Backcalculation of flexible pavement layer properties is an inverse problem with known input and output signals based upon which unknown parameters of the pavement system are evaluated. In this study, an inverse analysis procedure that combines the finite element analysis and a population-based optimization technique, Genetic Algorithm (GA has been developed to determine the pavement layer structural properties. A lightweight deflectometer (LWD was used to infer the moduli of instrumented three-layer scaled flexible pavement models. While the common practice in backcalculating pavement layer properties still assumes a static FWD load and uses only peak values of the load and deflections, dynamic analysis was conducted to simulate the impulse LWD load. The recorded time histories of the LWD load were used as the known inputs into the pavement system while the measured time-histories of surface central deflections and subgrade deflections measured with a linear variable differential transformers (LVDT were considered as the outputs. As a result, consistent pavement layer moduli can be obtained through this inverse analysis procedure.

  20. Numerical Study of Tire Hydroplaning Based on Power Spectrum of Asphalt Pavement and Kinetic Friction Coefficient

    Directory of Open Access Journals (Sweden)

    Shengze Zhu

    2017-01-01

    Full Text Available Hydroplaning is a driving phenomenon threating vehicle’s control stability and safety. It happens when tire rolls on wet pavement with high speed that hydrodynamic force uplifts the tire. Accurate numerical simulation to reveal the mechanism of hydroplaning and evaluate the function of relevant factors in this process is significant. In order to describe the friction behaviors of tire-pavement interaction, kinetic friction coefficient curve of tire rubber and asphalt pavement was obtained by combining pavement surface power spectrum and complex modulus of tread rubber through Persson’s friction theory. Finite element model of tire-fluid-pavement was established in ABAQUS, which was composed of a 225-40-R18 radial tire and three types of asphalt pavement covered with water film. Mechanical responses and physical behaviors of tire-pavement interaction were observed and compared with NASA equation to validate the applicability and accuracy of this model. Then contact force at tire-pavement interface and critical hydroplaning speed influenced by tire inflation pressure, water film thickness, and pavement types were investigated. The results show higher tire inflation pressure, thinner water film, and more abundant macrotexture enhancing hydroplaning speed. The results could be applied to predict hydroplaning speed on different asphalt pavement and improve pavement skid resistance design.