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Sample records for road deicing salt

  1. Road deicing salt irreversibly disrupts osmoregulation of salamander egg clutches.

    Science.gov (United States)

    Karraker, Nancy E; Gibbs, James P

    2011-03-01

    It has been postulated that road deicing salts are sufficiently diluted by spring rains to ameliorate any physiological impacts to amphibians breeding in wetlands near roads. We tested this conjecture by exposing clutches of the spotted salamander (Ambystoma maculatum) to three chloride concentrations (1 mg/L, 145 mg/L, 945 mg/L) for nine days, then transferred clutches to control water for nine days, and measured change in mass at three-day intervals. We measured mass change because water uptake by clutches reduces risks to embryos associated with freezing, predation, and disease. Clutches in controls sequestered water asymptotically. Those in the moderate concentrations lost 18% mass initially and regained 14% after transfer to control water. Clutches in high concentration lost 33% mass and then lost an additional 8% after transfer. Our results suggest that spring rains do not ameliorate the effects of deicing salts in wetlands with extremely high chloride concentrations.

  2. Road deicing salt irreversibly disrupts osmoregulation of salamander egg clutches

    Energy Technology Data Exchange (ETDEWEB)

    Karraker, Nancy E., E-mail: karraker@hku.hk [Department of Environmental and Forest Biology, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210 (United States); Gibbs, James P. [Department of Environmental and Forest Biology, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210 (United States)

    2011-03-15

    It has been postulated that road deicing salts are sufficiently diluted by spring rains to ameliorate any physiological impacts to amphibians breeding in wetlands near roads. We tested this conjecture by exposing clutches of the spotted salamander (Ambystoma maculatum) to three chloride concentrations (1 mg/L, 145 mg/L, 945 mg/L) for nine days, then transferred clutches to control water for nine days, and measured change in mass at three-day intervals. We measured mass change because water uptake by clutches reduces risks to embryos associated with freezing, predation, and disease. Clutches in controls sequestered water asymptotically. Those in the moderate concentrations lost 18% mass initially and regained 14% after transfer to control water. Clutches in high concentration lost 33% mass and then lost an additional 8% after transfer. Our results suggest that spring rains do not ameliorate the effects of deicing salts in wetlands with extremely high chloride concentrations. - Road deicing salts irreversibly disrupts osmoregulation of salamander egg clutches.

  3. Increase of urban lake salinity by road deicing salt

    Energy Technology Data Exchange (ETDEWEB)

    Novotny, Eric V.; Murphy, Dan [University of Minnesota, Department of Civil Engineering, St. Anthony Falls Laboratory, 2 Third Avenue SE, Minneapolis, MN 55414, 612-625-2810 (United States); Stefan, Heinz G. [University of Minnesota, Department of Civil Engineering, St. Anthony Falls Laboratory, 2 Third Avenue SE, Minneapolis, MN 55414, 612-625-2810 (United States)], E-mail: stefa001@umn.edu

    2008-11-15

    Over 317,000 tonnes of road salt (NaCl) are applied annually for road deicing in the Twin Cities Metropolitan Area (TCMA) of Minnesota. Although road salt is applied to increase driving safety, this practice influences environmental water quality. Thirteen lakes in the TCMA were studied over 46 months to determine if and how they respond to the seasonal applications of road salt. Sodium and chloride concentrations in these lakes were 10 and 25 times higher, respectively, than in other non-urban lakes in the region. Seasonal salinity/chloride cycles in the lakes were correlated with road salt applications: High concentrations in the winter and spring, especially near the bottom of the lakes, were followed by lower concentrations in the summer and fall due to flushing of the lakes by rainfall runoff. The seasonal salt storage/flushing rates for individual lakes were derived from volume-weighted average chloride concentration time series. The rate ranged from 9 to 55% of a lake's minimum salt content. In some of the lakes studied salt concentrations were high enough to stop spring turnover preventing oxygen from reaching the benthic sediments. Concentrations above the sediments were also high enough to induce convective mixing of the saline water into the sediment pore water. A regional analysis of historical water quality records of 38 lakes in the TCMA showed increases in lake salinity from 1984 to 2005 that were highly correlated with the amount of rock salt purchased by the State of Minnesota. Chloride concentrations in individual lakes were positively correlated with the percent of impervious surfaces in the watershed and inversely with lake volume. Taken together, the results show a continuing degradation of the water quality of urban lakes due to application of NaCl in their watersheds.

  4. Increase of urban lake salinity by road deicing salt.

    Science.gov (United States)

    Novotny, Eric V; Murphy, Dan; Stefan, Heinz G

    2008-11-15

    Over 317,000 tonnes of road salt (NaCl) are applied annually for road deicing in the Twin Cities Metropolitan Area (TCMA) of Minnesota. Although road salt is applied to increase driving safety, this practice influences environmental water quality. Thirteen lakes in the TCMA were studied over 46 months to determine if and how they respond to the seasonal applications of road salt. Sodium and chloride concentrations in these lakes were 10 and 25 times higher, respectively, than in other non-urban lakes in the region. Seasonal salinity/chloride cycles in the lakes were correlated with road salt applications: High concentrations in the winter and spring, especially near the bottom of the lakes, were followed by lower concentrations in the summer and fall due to flushing of the lakes by rainfall runoff. The seasonal salt storage/flushing rates for individual lakes were derived from volume-weighted average chloride concentration time series. The rate ranged from 9 to 55% of a lake's minimum salt content. In some of the lakes studied salt concentrations were high enough to stop spring turnover preventing oxygen from reaching the benthic sediments. Concentrations above the sediments were also high enough to induce convective mixing of the saline water into the sediment pore water. A regional analysis of historical water quality records of 38 lakes in the TCMA showed increases in lake salinity from 1984 to 2005 that were highly correlated with the amount of rock salt purchased by the State of Minnesota. Chloride concentrations in individual lakes were positively correlated with the percent of impervious surfaces in the watershed and inversely with lake volume. Taken together, the results show a continuing degradation of the water quality of urban lakes due to application of NaCl in their watersheds.

  5. Impacts of road deicing salt on the demography of vernal pool-breeding amphibians.

    Science.gov (United States)

    Karraker, Nancy E; Gibbs, James P; Vonesh, James R

    2008-04-01

    Deicing agents, primarily road salt, are applied to roads in 26 states in the United States and in a number of European countries, yet the scale of impacts of road salt on aquatic organisms remains largely under-studied. The issue is germane to amphibian conservation because both adult and larval amphibians are known to be particularly sensitive to changes in their osmolar environments. In this study, we combined survey, experimental, and demographic modeling approaches to evaluate the possible effects of road salt on two common vernal-pond-breeding amphibian species, the spotted salamander (Ambystoma maculatum) and the wood frog (Rana sylvatica). We found that in the Adirondack Mountain Region of New York (USA), road salt traveled up to 172 m from the highway into wetlands. Surveys showed that egg mass densities of spotted salamanders (A. maculatum) and wood frogs (R. sylvatica) were two times higher in forest pools than roadside pools, but this pattern was better explained by road proximity than by increased salinity. Experiments demonstrated that embryonic and larval survival were reduced at moderate (500 muS) and high conductivities (3000 muS) in A. maculatum and at high conductivities in R. sylvatica. Demographic models suggest that such egg and larval stage effects of salt may have important impacts on populations near roads, particularly in the case of A. maculatum, for which salt exposure may lead to local extinction. For both species, the effect of road salt was dependent upon the strength of larval density dependence and declined rapidly with distance from the roadside, with the greatest negative effects being limited to within 50 m. Based on this evidence, we argue that efforts to protect local populations of A. maculatum and R. sylvatica in roadside wetlands should, in part, be aimed at reducing application of road salt near wetlands with high conductivity levels.

  6. Effects of road de-icing salt (NaCl) on larval wood frogs (Rana sylvatica).

    Science.gov (United States)

    Sanzo, Domenico; Hecnar, Stephen J

    2006-03-01

    Vast networks of roads cover the earth and have numerous environmental effects including pollution. A major component of road runoff in northern countries is salt (mostly NaCl) used as a winter de-icing agent, but few studies of effects of road salts on aquatic organisms exist. Amphibians require aquatic habitats and chemical pollution is implicated as a major factor in global population declines. We exposed wood frog tadpoles to NaCl. Tests revealed 96-h LC50 values of 2,636 and 5,109 mg/l and tadpoles experienced reduced activity, weight, and displayed physical abnormalities. A 90 d chronic experiment revealed significantly lower survivorship, decreased time to metamorphosis, reduced weight and activity, and increased physical abnormalities with increasing salt concentration (0.00, 0.39, 77.50, 1,030.00 mg/l). Road salts had toxic effects on larvae at environmentally realistic concentrations with potentially far-ranging ecological impacts. More studies on the effects of road salts are warranted.

  7. Impacts of road deicing salts on the early-life growth and development of a stream salmonid: Salt type matters.

    Science.gov (United States)

    Hintz, William D; Relyea, Rick A

    2017-04-01

    The use of road deicing salts in regions that experience cold winters is increasing the salinity of freshwater ecosystems, which threatens freshwater resources. Yet, the impacts of environmentally relevant road salt concentrations on freshwater organisms are not well understood, particularly in stream ecosystems where salinization is most severe. We tested the impacts of deicing salts-sodium chloride (NaCl), magnesium chloride (MgCl2), and calcium chloride (CaCl2)-on the growth and development of newly hatched rainbow trout (Oncorhynchus mykiss). We exposed rainbow trout to a wide range of environmentally relevant chloride concentrations (25, 230, 860, 1500, and 3000 mg Cl(-) L(-1)) over an ecologically relevant time period (25 d). We found that the deicing salts studied had distinct effects. MgCl2 did not affect rainbow trout growth at any concentration. NaCl had no effects at the lowest three concentrations, but rainbow trout length was reduced by 9% and mass by 27% at 3000 mg Cl(-) L(-1). CaCl2 affected rainbow trout growth at 860 mg Cl(-) L(-1) (5% reduced length; 16% reduced mass) and these effects became larger at higher concentrations (11% reduced length; 31% reduced mass). None of the deicing salts affected rainbow trout development. At sub-lethal and environmentally relevant concentrations, our results do not support the paradigm that MgCl2 is the most toxic deicing salt to fish, perhaps due to hydration effects on the Mg(2+) cation. Our results do suggest different pathways for lethal and sub-lethal effects of road salts. Scaled to the population level, the reduced growth caused by NaCl and CaCl2 at critical early-life stages has the potential to negatively affect salmonid recruitment and population dynamics. Our findings have implications for environmental policy and management strategies that aim to reduce the impacts of salinization on freshwater organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Effect of road deicing salt on the susceptibility of amphibian embryos to infection by water molds.

    Science.gov (United States)

    Karraker, Nancy E; Ruthig, Gregory R

    2009-01-01

    Some causative agents of amphibian declines act synergistically to impact individual amphibians and their populations. In particular, pathogenic water molds (aquatic oomycetes) interact with environmental stressors and increase mortality in amphibian embryos. We documented colonization of eggs of three amphibian species, the wood frog (Rana sylvatica), the green frog (Rana clamitans), and the spotted salamander (Ambystoma maculatum), by water molds in the field and examined the interactive effects of road deicing salt and water molds, two known sources of mortality for amphibian embryos, on two species, R. clamitans and A. maculatum in the laboratory. We found that exposure to water molds did not affect embryonic survivorship in either A. maculatum or R. clamitans, regardless of the concentration of road salt to which their eggs were exposed. Road salt decreased survivorship of A. maculatum, but not R. clamitans, and frequency of malformations increased significantly in both species at the highest salinity concentration. The lack of an effect of water molds on survival of embryos and no interaction between road salt and water molds indicates that observations of colonization of these eggs by water molds in the field probably represent a secondary invasion of unfertilized eggs or of embryos that had died of other causes. Given increasing salinization of freshwater habitats on several continents and the global distribution of water molds, our results suggest that some amphibian species may not be susceptible to the combined effects of these factors, permitting amphibian decline researchers to devote their attention to other potential causes.

  9. Effects of applying deicing salt to roads in protected areas: a preliminary study in the Bavarian Forest National Park

    Directory of Open Access Journals (Sweden)

    Zdenka Křenová

    2012-09-01

    Full Text Available The negative effects of applying deicing salts to ecosystems are well documented for many countries. In some countries, the application of the deicing salts to roads in protected areas is prohibited by law. There is little detailed knowledge of the effects of deicing salts on ecosystems in the Bavarian Forest NP. The first preliminary study was conducted in 2011 and the first results are published in this paper. Nine permanent study sites were established and significant differences in soil chemical parameters among the different sites were recorded. The highest amounts of Na+ and Cl− ions were recorded at study site #4, which is located only a few meters from the bank of the Grosse Ohe River. Much higher concentrations of Na+ and Cl− ions were found at 10 meters from the road than at the road edge and it is assumed that this is due to long-term contamination from water accumulating from melting snow. There were also higher concentrations of salt ions recorded at other sites along the main road. It is important that trajectories of the mobility of ions, including seasonal variability and commutations of salt in ecosystems, should be studied in future.

  10. Potential for local adaptation in response to an anthropogenic agent of selection: effects of road deicing salts on amphibian embryonic survival and development

    OpenAIRE

    Hopkins, Gareth R; Susannah S French; Brodie, Edmund D.

    2012-01-01

    The application of millions of tons of road deicing salts every winter in North America presents significant survival challenges to amphibians inhabiting roadside habitats. While much is known of the effects of NaCl on anuran tadpoles, less is known of effects on amphibian eggs, or any caudate life stage. In addition, little is known of the effects of MgCl2, which is now the 2nd most commonly used road deicer. Most studies have considered amphibians to be helpless victims of deicing salts, an...

  11. Cumulative effects of road de-icing salt on amphibian behavior.

    Science.gov (United States)

    Denoël, Mathieu; Bichot, Marion; Ficetola, Gentile Francesco; Delcourt, Johann; Ylieff, Marc; Kestemont, Patrick; Poncin, Pascal

    2010-08-15

    Despite growing evidence of the detrimental effect of chemical substances on organisms, limited research has focused on changes in behavioral patterns, in part due to the difficulties to obtain detailed quantitative data. Recent developments in efficient computer-based video analyses have allowed testing pesticide effects on model species such as the zebrafish. However, these new techniques have not yet been applied to amphibians and directly to conservation issues, i.e., to assess toxicological risks on threatened species. We used video-tracking analyses to test a quantitative effect of an environmental contaminant on the locomotion of amphibian tadpoles (Rana temporaria) by taking into account cumulative effects. Because recent research has demonstrated effects of de-icing salts on survival and community structure, we used sodium chloride in our experimental design (25 replicates, 4 concentrations, 4 times) to test for an effect at the scale of behavior at environmentally relevant concentrations. Analysis of 372 1-h video-tracks (5 samples/s) showed a complex action of salts on behavioral patterns with a dose and cumulative response over time. Although no effects were found on mortality or growth, the highest salt concentrations reduced the speed and movement of tadpoles in comparison with control treatments. The reduced locomotor performance could have detrimental consequences in terms of tadpoles' responses to competition and predation and may be an indicator of the low concentration effect of the contaminant. On one hand, this study demonstrates the usefulness of examining behavior to address conservation issues and understand the complex action of environmental factors and, more particularly, pollutants on organisms. On the other hand, our results highlight the need of new computerized techniques to quantitatively analyze these patterns.

  12. Potential for local adaptation in response to an anthropogenic agent of selection: effects of road deicing salts on amphibian embryonic survival and development.

    Science.gov (United States)

    Hopkins, Gareth R; French, Susannah S; Brodie, Edmund D

    2013-02-01

    The application of millions of tons of road deicing salts every winter in North America presents significant survival challenges to amphibians inhabiting roadside habitats. While much is known of the effects of NaCl on anuran tadpoles, less is known of effects on amphibian eggs, or any caudate life stage. In addition, little is known of the effects of MgCl2, which is now the 2nd most commonly used road deicer. Most studies have considered amphibians to be helpless victims of deicing salts, and ignore the possibility of the evolution of local adaptation to this stressor. We attempt to address these knowledge gaps and explore this evolutionary potential by examining the effects of NaCl and MgCl2 on the survival and development of eggs from different female rough-skinned newts (Taricha granulosa) from the same population. We demonstrate that both salts, at environmentally relevant concentrations, severely affect the embryonic survival and development of this amphibian, but that the effects of the salt are dependent on the identity of the mother. This female × treatment interaction results in substantial variation in tolerance to road deicing salts among newt families, providing the raw material necessary for natural selection and the evolution of local adaptation in this amphibian.

  13. Toxicity of road deicing salt (NaCl) and copper (Cu) to fertilization and early developmental stages of Atlantic salmon (Salmo salar).

    Science.gov (United States)

    Mahrosh, Urma; Kleiven, Merethe; Meland, Sondre; Rosseland, Bjørn Olav; Salbu, Brit; Teien, Hans-Christian

    2014-09-15

    In many countries, salting of ice or snow covered roads may affect aquatic organisms in the catchment directly or indirectly by mobilization of toxic metals. We studied the toxicity of road deicing salt and copper (Cu) on the vulnerable early life stages of Atlantic salmon (Salmo salar), from fertilization till hatching. Controlled episodic exposure to road salt (≥ 5,000 mg/L) during fertilization resulted in reduced swelling and less percent egg survival. Exposure to Cu both during and post fertilization caused delayed hatching. Larval deformities were, however found as an additional effect, when eggs were exposed to high salt concentration (≥ 5,000 mg/L) mixed with Cu (10 μg Cu/L) during fertilization. Thus, it appears that the sensitivity of early developmental stages of Atlantic salmon increased when exposed to these stressors, and road salt application during spawning can pose threat to Atlantic salmon in water bodies receiving road runoff. The study gives insight on assessment and management of risks on Atlantic salmon population posed by road related hazardous chemicals.

  14. Heavy metal removal mechanisms of sorptive filter materials for road runoff treatment and remobilization under de-icing salt applications.

    Science.gov (United States)

    Huber, Maximilian; Hilbig, Harald; Badenberg, Sophia C; Fassnacht, Julius; Drewes, Jörg E; Helmreich, Brigitte

    2016-10-01

    The objective of this research study was to elucidate the removal and remobilization behaviors of five heavy metals (i.e., Cd, Cu, Ni, Pb, and Zn) that had been fixed onto sorptive filter materials used in decentralized stormwater treatment systems receiving traffic area runoff. Six filter materials (i.e., granular activated carbon, a mixture of granular activated alumina and porous concrete, granular activated lignite, half-burnt dolomite, and two granular ferric hydroxides) were evaluated in column experiments. First, a simultaneous preloading with the heavy metals was performed for each filter material. Subsequently, the remobilization effect was tested by three de-icing salt experiments in duplicate using pure NaCl, a mixture of NaCl and CaCl2, and a mixture of NaCl and MgCl2. Three layers of each column were separated to specify the attenuation of heavy metals as a function of depth. Cu and Pb were retained best by most of the selected filter materials, and Cu was often released the least of all metals by the three de-icing salts. The mixture of NaCl and CaCl2 resulted in a stronger effect upon remobilization than the other two de-icing salts. For the material with the highest retention, the effect of the preloading level upon remobilization was measured. The removal mechanisms of all filter materials were determined by advanced laboratory methods. For example, the different intrusions of heavy metals into the particles were determined. Findings of this study can result in improved filter materials used in decentralized stormwater treatment systems.

  15. Mobilization of arsenic, lead, and mercury under conditions of sea water intrusion and road deicing salt application

    Science.gov (United States)

    Sun, Hongbing; Alexander, John; Gove, Brita; Koch, Manfred

    2015-09-01

    Water geochemistry data from complexly designed salt-solution injection experiments in the laboratory, coastal aquifers of Bangladesh and Italy, taken from the literature, and two salted watersheds of New Jersey, US were collected and analyzed to study the geochemical mechanisms that mobilize As, Pb, and Hg under varied salting conditions. Overall, increased NaCl-concentrations in aquifers and soil are found to increase the release of Pb and Hg into the water. Reducing environments and possible soil dispersion by hydrated Na+ are found to lead to an increase of As-concentration in water. However, the application of a pure NaCl salt solution in the column injection experiment was found to release less As, Pb, and Hg initially from the soil and delay their concentration increase, when compared to the application of CaCl2 and NaCl mixed salts (at 6:4 weight ratio). The concentration correlation dendrogram statistical analyses of the experimental and field data suggest that the release of As, Hg, and Pb into groundwater and the soil solution depends not only on the salt level and content, but also on the redox condition, dissolved organic matter contents, competitiveness of other ions for exchange sites, and source minerals. With the ongoing over-exploration of coastal aquifers from increased pumping, continued sea-level rise, and increased winter deicing salt applications in salted watersheds of many inland regions, the results of this study will help understand the complex relation between the concentrations of As, Pb, and Hg and increased salt level in a coastal aquifer and in soils of a salted watershed.

  16. Increased frequency and severity of developmental deformities in rough-skinned newt (Taricha granulosa) embryos exposed to road deicing salts (NaCl & MgCl2).

    Science.gov (United States)

    Hopkins, Gareth R; French, Susannah S; Brodie, Edmund D

    2013-02-01

    Road-side aquatic ecosystems in North America are annually polluted with millions of tons of road deicing salts, which threaten the survival of amphibians which live and breed in these habitats. While much is known of the effects of NaCl, little is known of the second most-commonly used deicer, MgCl(2), which is now used exclusively in parts of the continent. Here we report that environmentally relevant concentrations of both NaCl and MgCl(2) cause increased incidence of developmental deformities in rough-skinned newt hatchlings that developed embryonically in these salts. In addition, we provide some of the first quantification of severity of different deformities, and reveal that increased salt concentrations increase both deformity frequency and severity. Our work contributes to the growing body of literature that suggests salamanders and newts are particularly vulnerable to salt, and that the emerging pollutant, MgCl(2) is comparable in its effects to the more traditionally-used NaCl.

  17. Corrosion Detection of Road Deicing Salt on Carbon Steel and Corrosion Reducing Treatments%公路融雪剂碳钢腐蚀性检测方法及缓蚀工艺研究

    Institute of Scientific and Technical Information of China (English)

    陈宗伟; 张立塔; 赫恩龙; 刘涛

    2011-01-01

    Application of chloride deicing salt improves the efficiency of snow removal, but it also causes the corrosion of road infrastructures. Deicing salt concentration and its experimental environment are significant effect on the corrosion detection results. Considering the actual road snow conditions and requirements of road area environmental protection, the carbon steel corrosion detection method is optimized. The tested deicing salt concentration is proposed to 35 g/L, and deicing salt corrosion index adjusted to less than 20% corrosion rate of industrial sodium chloride. Carbon steel corrosion rate of deicing salt which added different ratio of corrosion inhibit ingredients reduced to 0. 064 ~0. 442 mm/a, equivalent to only 7. 9%~54. 7% that of industrial sodium chloride. The optimum deicing salt formula is: 97. 5% of industrial chloride salt, 0. 5% of corrosion inhibitor A, B and D, 1.0% of corrosion inhibitor C.%氯盐型融雪剂的应用提高了公路融雪除冰效率,也对路面基础设施造成了一定的腐蚀影响.通过对比实验发现融雪剂浓度和实验环境对检测结果影响显著,考虑实际融雪后雪水状况与路域生态环境保护需要,优化了碳钢腐蚀性检测方法,建议待测融雪剂溶液浓度调整为35 g/L,融雪剂碳钢腐蚀性评价指标调整为低于氯化钠(工业品)腐蚀率的20%.添加不同配比缓蚀剂成分的融雪剂溶液可使碳钢腐蚀速率降低至0.064~0.442mm/a,仅相当于工业氯化钠腐蚀性的7.9%~54.7%.较优的融雪剂配方为:工业盐97.5%、缓蚀剂A添加0.5%、缓蚀剂B添加0.5%、缓蚀剂C添加1.0%、缓蚀剂D添加0.5%.

  18. Use of borehole and surface geophysics to investigate ground-water quality near a road-deicing salt-storage facility, Valparaiso, Indiana

    Science.gov (United States)

    Risch, M.R.; Robinson, B.A.

    2001-01-01

    Borehole and surface geophysics were used to investigate ground-water quality affected by a road-deicing salt-storage facility located near a public water-supply well field. From 1994 through 1998, borehole geophysical logs were made in an existing network of monitoring wells completed near the bottom of a thick sand aquifer. Logs of natural gamma activity indicated a uniform and negligible contribution of clay to the electromagnetic conductivity of the aquifer so that the logs of electromagnetic conductivity primarily measured the amount of dissolved solids in the ground water near the wells. Electromagneticconductivity data indicated the presence of a saltwater plume near the bottom of the aquifer. Increases in electromagnetic conductivity, observed from sequential logging of wells, indicated the saltwater plume had moved north about 60 to 100 feet per year between 1994 and 1998. These rates were consistent with estimates of horizontal ground-water flow based on velocity calculations made with hydrologic data from the study area.

  19. Groundwater Infiltration Path of Road Deicing Agent and its Quantification

    Science.gov (United States)

    Moroizumi, T.; Hada, J.; Sasaki, K.

    2015-12-01

    A deicing agent has been sprinkled on an expressway to prevent it from freezing in the hilly and mountainous area along the expressway having been used for more than 30 years. We investigated the infiltration, the river runoff, and the scattering of the de-icing agent quantitatively, observed the variation of water quality in river, and discussed the infiltration route and balance of the deicing agent in order to clarify the influence of the de-icing agent on the groundwater salinization. As a result, it turned out that 65% of the de-icing agent sprinkled on the road surface flowed into the waterway, the 25% infiltrated into underground through the crack of a road surface, and the remaining 10% dispersed out of an expressway. Next, for the rate of the de-icing agent outflowing to the river during a frozen snow term, it was estimated that the 39% of the sprinkled de-icing agent outflowed with surface water, and the 17% did with groundwater. Moreover, it was shown clearly that the 44% was probably stored in underground from the balance between the sprinkled de-icing agent and the outflowing one. In addition, the Cl- concentration of groundwater by the infiltrated deicing agent was simulated to clarify its extent and to predict its change in future when stopped sprinkling the deicing agent.

  20. Increased chloride concentration in a lake due to deicing salt application.

    Science.gov (United States)

    Thunqvist, E L

    2003-01-01

    During winter, the Swedish National Road Administration uses on average 250,000 tonnes of sodium chloride for deicing purposes. Chloride concentration is a function of the amount of deicing salt applied during the winter season and the amount of water in which the salt can be diluted. An estimation of seasonal amount of deicing salt in relation to amount of run-off was used in order to identify the effects of deicing salt. The measured chloride concentration in a lake used as a municipal water supply was similar to the concentration estimated by a simple steady state method accounting for the catchment area. The simplified steady state method was a useful tool for estimating steady state concentrations on a regional level, including a non-influenced lake as a comparison.

  1. CONTRIBUTION FROM DEICING SALT TO CHEMICAL COMPOSITION OF SALT SUPPLYED TO AREA UNDER THE BRIDGES

    Science.gov (United States)

    Takebe, Masamichi; Ohya, Makoto; Hirose, Nozomu; Ochibe, Keishi; Aso, Toshihiko

    Salt is known to accelerate the corrosion of weathering steel bridges. The origin of salt around girders is valuable information in terms of the maintenance for anti-corrosion of steel bridges. Salt around girders generally originates from sea-salt and deicing salt. Since salt of both origin increases in winter, contribution of deicing salt is hard to be estimated only from fluctuation of total abundance of salt around the bridge. In this study, abundance of Mg2+ as well as that of Cl- in salt sampled under bridges is analyzed. As a result, this study revealed that the supply of deicing salt declines Mg2+/Cl- ratio of salt on the girder. In addition, examination of Mg2+/Cl- ratio of salt sampled under the examined bridge near sea revealed that the fluctuation of quantity of air-born salt under the bridge is ascribed to the fluctuation of supply of sea salt.

  2. Regional increase of mean chloride concentration in water due to the application of deicing salt.

    Science.gov (United States)

    Thunqvist, Eva-Lotta

    2004-06-05

    The Directive of the European Parliament and of the Council 2000/60/EC: Establishing a Framework for Community Action in the Field of Water Policy, states that it is necessary to consider human activities within a river basin in order to prevent and reduce the spreading of pollutants and to achieve good water status. This paper shows a simple method to estimate the environmental pressure from the deicing of roads as steady state chloride concentration in water. The data processed are presented using GIS. The result showed that the contribution of deicing salt is of importance for the chloride concentration on a regional scale. The increase in chloride concentration is also compared to the background concentration and other sources of chloride within the river basin. Road salt applied by the Swedish National Road Administration (SNRA) accounts for more than half of the total chloride load for the river basin investigated. The method presented may easily be generalised to a national scale for monitoring the environmental effects of deicing salt application.

  3. Freezing points and small-scale deicing tests for salts of levulinic acid made from grain sorghum.

    Science.gov (United States)

    Ganjyal, G; Fang, Q; Hanna, M A

    2007-11-01

    Deicers from renewable resources are needed to overcome the disadvantages of using traditional deicers. Salts made from levulinic acid produced using grain sorghum as raw material were tested as road deicing agents. Freezing points of these salts viz., sodium levulinate, magnesium levulinate and calcium levulinate along with rock salt (sodium chloride) were determined according to American Society for Testing and Materials (ASTM) D 1177-94 standard at concentrations of 10, 20, 30 and 40 % w/w. There were significant differences among the freezing points of the salts. Freezing points for rock salt, sodium levulinate, calcium levulinate and magnesium levulinate, for different concentrations, were in the ranges of -6.6 to -20.5, -2.9 to -15.0, -2.1 to -7.8 and -1.5 to -6.5 degrees C, respectively. Deicing effectiveness of the salts of levulinic acid were investigated by conducting small-scale deicing tests with aqueous solutions of various salt concentrations (2%, 5% and 10%) in a laboratory freezer and by spraying the deicer on a graveled surface covered by ice and snow with the average temperature during the testing at -2.7 degrees C. Deicing capabilities of the three salts of levulinic acid differed. At -2.7 degrees C, all three salts caused melting of the ice. Among the different levulinates studied sodium levulinate was the most effective deicing agent. These salts of levulinates could be a viable replacement for traditional deicers and could help in reducing the disadvantages of traditional deicers.

  4. Acidity and mineral composition of precipitation in Moscow: Influence of deicing salts

    Science.gov (United States)

    Eremina, I. D.; Aloyan, A. E.; Arutyunyan, V. O.; Larin, I. K.; Chubarova, N. E.; Yermakov, A. N.

    2015-11-01

    Monitoring data and analysis of the variation in acidity and mineral composition of atmospheric precipitation in Moscow in 2012 are presented. We have found that the chloride anions in the precipitation are largely caused by chlorides of deicing salts. Here, the chloride anions, along with metal chlorides (components of deicing salts), are partly caused by dissolved hydrogen chloride. The appearance of hydrogen chloride in the atmosphere of Moscow has been shown to result from heterophase chemical reactions involving deicing salts. We have obtained preliminary estimates for the scales of the effect of these salts on the mineral composition and acidity of precipitations in Moscow.

  5. Highway deicing salt dynamic runoff to surface water and subsequent infiltration to groundwater during severe UK winters.

    Science.gov (United States)

    Rivett, Michael O; Cuthbert, Mark O; Gamble, Richard; Connon, Lucy E; Pearson, Andrew; Shepley, Martin G; Davis, John

    2016-09-15

    Dynamic impact to the water environment of deicing salt application at a major highway (motorway) interchange in the UK is quantitatively evaluated for two recent severe UK winters. The contaminant transport pathway studied allowed controls on dynamic highway runoff and storm-sewer discharge to a receiving stream and its subsequent leakage to an underlying sandstone aquifer, including possible contribution to long-term chloride increases in supply wells, to be evaluated. Logged stream electrical-conductivity (EC) to estimate chloride concentrations, stream flow, climate and motorway salt application data were used to assess salt fate. Stream loading was responsive to salt applications and climate variability influencing salt release. Chloride (via EC) was predicted to exceed the stream Environmental Quality Standard (250mg/l) for 33% and 18% of the two winters. Maximum stream concentrations (3500mg/l, 15% sea water salinity) were ascribed to salt-induced melting and drainage of highway snowfall without dilution from, still frozen, catchment water. Salt persistance on the highway under dry-cold conditions was inferred from stream observations of delayed salt removal. Streambed and stream-loss data demonstrated chloride infiltration could occur to the underlying aquifer with mild and severe winter stream leakage estimated to account for 21 to 54% respectively of the 70t of increased chloride (over baseline) annually abstracted by supply wells. Deicing salt infiltration lateral to the highway alongside other urban/natural sources were inferred to contribute the shortfall. Challenges in quantifying chloride mass/fluxes (flow gauge accuracy at high flows, salt loading from other roads, weaker chloride-EC correlation at low concentrations), may be largely overcome by modest investment in enhanced data acquisition or minor approach modification. The increased understanding of deicing salt dynamic loading to the water environment obtained is relevant to improved

  6. Improving the Performance of Road Salt on Anti-Icing

    OpenAIRE

    Lende, Wibeke

    2014-01-01

    Winter maintenance is a challenging field, especially in parts of the world with a temperate climate. The friction of the road surface has to be kept at an acceptable level so that the demands for traffic safety and mobility are fulfilled. Road salts are used in large quantities for both anti-icing and de-icing objectives, because they depress the freezing point of water.An alternative mechanism of the anti-icing wet pavement freezing has recently been introduced. It says that the salt does n...

  7. Long-term ferrocyanide application via deicing salts promotes the establishment of Actinomycetales assimilating ferrocyanide-derived carbon in soil.

    Science.gov (United States)

    Gschwendtner, Silvia; Mansfeldt, Tim; Kublik, Susanne; Touliari, Evangelia; Buegger, Franz; Schloter, Michael

    2016-07-01

    Cyanides are highly toxic and produced by various microorganisms as defence strategy or to increase their competitiveness. As degradation is the most efficient way of detoxification, some microbes developed the capability to use cyanides as carbon and nitrogen source. However, it is not clear if this potential also helps to lower cyanide concentrations in roadside soils where deicing salt application leads to significant inputs of ferrocyanide. The question remains if biodegradation in soils can occur without previous photolysis. By conducting a microcosm experiment using soils with/without pre-exposition to road salts spiked with (13) C-labelled ferrocyanide, we were able to confirm biodegradation and in parallel to identify bacteria using ferrocyanide as C source via DNA stable isotope probing (DNA-SIP), TRFLP fingerprinting and pyrosequencing. Bacteria assimilating (13) C were highly similar in the pre-exposed soils, belonging mostly to Actinomycetales (Kineosporia, Mycobacterium, Micromonosporaceae). In the soil without pre-exposition, bacteria belonging to Acidobacteria (Gp3, Gp4, Gp6), Gemmatimonadetes (Gemmatimonas) and Gammaproteobacteria (Thermomonas, Xanthomonadaceae) used ferrocyanide as C source but not the present Actinomycetales. This indicated that (i) various bacteria are able to assimilate ferrocyanide-derived C and (ii) long-term exposition to ferrocyanide applied with deicing salts leads to Actinomycetales outcompeting other microorganisms for the use of ferrocyanide as C source.

  8. The Fate of De-icing Salts in Stormwater Management Systems

    Science.gov (United States)

    Ballestero, T. P.; Roseen, R. M.; Houle, J. J.

    2005-05-01

    The traditional paradigm behind the design of stormwater management systems is to minimize the water quantity and water quality impacts resulting from land modification. The intent is to yield post-development hydrology similar to pre-development hydrology. The water quality aspect has been primarily focused on sediment removal, however, rarely are stormwater management systems designed for removal of de-icing salt. Chloride toxicity effects upon aquatic organisms resulting from snowmelt runoff are pronounced, routine, and problematic in northern climates. The capacity of current management strategies to treat chloride is in question. This paper explores the fate of de-icing salt through 13 different stormwater management systems. The systems include swales, retention pond, infiltration systems, bioretention systems, wetlands, manufactured devices, and porous asphalt. All systems exist at a field site and are delivered the same runoff (quantity and quality). The devices were designed and installed in accordance with existing drainage manual recommendations. None were designed for salt removal. As expected, devices with minimal water storage do not remove salt. Devices that do have significant amounts of storage do not remove salt, however the effluent concentrations are not as high as the influent concentrations: the peak influent salt concentration is attenuated similar to how the peak inflow discharge is attenuated by storage routing. The porous asphalt has displayed some remarkable characteristics. This surface has remained permeable throughout the winter, even though in addition to the de-icing chemicals, sand is applied. It appears that very little de-icing salt is needed on the surface, which has enormous economic and environmental implications.

  9. Effects of ion exchange on stream solute fluxes in a basin receiving highway deicing salts

    Science.gov (United States)

    Shanley, J.B.

    1994-01-01

    At Fever Brook, a 1260-ha forested basin in central Massachusetts, highway deicing salt application increased the solute flux in streamflow by 120% above background flux (equivalent basis) during a 2-yr period. Attempts to isolate the nonsalt component of stream solute fluxes have commonly subtracted salt contributions based on the net Cl flux (Cl output in streamflow minus Cl input in precipitation). In these studies, any net Na flux in excess of the amount needed to balance the net Cl flux has been attributed to weathering. At Fever Brook, however, the net output of Na was less than the net output of Cl, suggesting a loss of Na within the basin. The Na sink was inferred to be cation exchange of Na for Ca and Mg in the soil. A method was developed to quantify the exchange based on a Na budget, which included an independent estimate of the Na flux from weathering. The amount of exchange was apportioned to Ca and Mg based on their relative concentrations in the stream. The background fluxes of Ca and Mg (i.e., those that would occur in the absence of deicing salts) were calculated by subtracting the amounts from ion exchange plus the much smaller direct contributions in deicing salts from the observed fluxes. Ion exchange and direct salt contributions increased the net output fluxes of Ca and Mg, each by 44% above background. In basins that receive deicing salts, failure to account for cation exchange thus may result in an underestimate of the flux of Na from weathering and overestimates of the fluxes of Ca and Mg from weathering.

  10. Retention of heavy metals and poly-aromatic hydrocarbons from road water in a constructed wetland and the effect of de-icing

    KAUST Repository

    Tromp, Karin

    2012-02-01

    A full-scale remediation facility including a detention basin and a wetland was tested for retention of heavy metals and Poly-Aromatic Hydrocarbons (PAHs) from water drained from a motorway in The Netherlands. The facility consisted of a detention basin, a vertical-flow reed bed and a final groundwater infiltration bed. Water samples were taken of road water, detention basin influent and wetland effluent. By using automated sampling, we were able to obtain reliable concentration averages per 4-week period during 18 months. The system retained the PAHs very well, with retention efficiencies of 90-95%. While environmental standards for these substances were surpassed in the road water, this was never the case after passage through the system. For the metals the situation was more complicated. All metals studied (Cu, Zn, Pb, Cd and Ni) had concentrations frequently surpassing environmental standards in the road water. After passage through the system, most metal concentrations were lower than the standards, except for Cu and Zn. There was a dramatic effect of de-icing salts on the concentrations of Cu, Zn, Cd and Ni, in the effluent leaving the system. For Cu, the concentrations even became higher than they had ever been in the road water. It is advised to let the road water bypass the facility during de-icing periods. © 2011 Elsevier B.V.

  11. EXPERIMENTAL STUDIES ON DEVELOPMENT OF SUSTAINABLE AGRICULTURAL-BASED ROAD TRANSPORT DEICING APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Peter C. Taylor

    2014-06-01

    Full Text Available Snow and ice removal on highways and public streets is critical for safe operation of the road transportation infrastructure. The issues to be addressed in selecting suitable deicing and anti-icing materials include cost, effectiveness, and damage to the pavement, vehicles and the environment. Considerable research has been carried out in recent years to develop alternative deicers with better performance and cost effectiveness. Among the developed deicer materials are agricultural based deicers that are considered to be sustainable and environmentally-beneficial materials. Iowa is one of the States that is rich in agricultural renewable resources, some of which are being processed for applications such as fuel. Any industrial process, including that of converting corn to ethanol or soy to bio-diesel, is likely to have a number of by-products generated. Rather than face disposal issues for these by-products, it would be desirable to find those that, with a minimum of additional processing, can be used as a deicing compound, either alone, or in combination with products currently in use. Currently, a number of agricultural based deicer materials have been developed or are still under development. However, little information is known about the actual manufacturing/refining process since most of the developed materials are all proprietary products (patented or commercial. Furthermore, no standard test specifying agricultural-based deicer is available. The study described in this paper focuses on the development of an improved agricultural based deicing product. The objective of this study was to evaluate deicer materials including traditional and alternative deicer materials on road skid resistance which is critical for safe operation of the road transportation infrastructure.

  12. Runoff of deicing salt: effect on irondequoit bay, Rochester, new york.

    Science.gov (United States)

    Bubeck, R C; Diment, W H; Deck, B L; Baldwin, A L; Lipton, S D

    1971-06-11

    Salt used for deicing the streets near Rochester, New York, has increased the chloride concentration in Irondequoit Bay at least fivefold during the past two decades. During the winter of 1969-70 the quantity and salinity of the dense runoff that accumulated on the bottom of the bay was sufficient to prevent complete vertical mixing of the bay during the spring. Comparison with 1939 conditions indicates that the period of summer stratification has been prolonged a month by the density gradient imposed by the salt runoff.

  13. Road salt emissions: A comparison of measurements and modelling using the NORTRIP road dust emission model

    Science.gov (United States)

    Denby, B. R.; Ketzel, M.; Ellermann, T.; Stojiljkovic, A.; Kupiainen, K.; Niemi, J. V.; Norman, M.; Johansson, C.; Gustafsson, M.; Blomqvist, G.; Janhäll, S.; Sundvor, I.

    2016-09-01

    De-icing of road surfaces is necessary in many countries during winter to improve vehicle traction. Large amounts of salt, most often sodium chloride, are applied every year. Most of this salt is removed through drainage or traffic spray processes but a certain amount may be suspended, after drying of the road surface, into the air and will contribute to the concentration of particulate matter. Though some measurements of salt concentrations are available near roads, the link between road maintenance salting activities and observed concentrations of salt in ambient air is yet to be quantified. In this study the NORTRIP road dust emission model, which estimates the emissions of both dust and salt from the road surface, is applied at five sites in four Nordic countries for ten separate winter periods where daily mean ambient air measurements of salt concentrations are available. The model is capable of reproducing many of the salt emission episodes, both in time and intensity, but also fails on other occasions. The observed mean concentration of salt in PM10, over all ten datasets, is 4.2 μg/m3 and the modelled mean is 2.8 μg/m3, giving a fractional bias of -0.38. The RMSE of the mean concentrations, over all 10 datasets, is 2.9 μg/m3 with an average R2 of 0.28. The mean concentration of salt is similar to the mean exhaust contribution during the winter periods of 2.6 μg/m3. The contribution of salt to the kerbside winter mean PM10 concentration is estimated to increase by 4.1 ± 3.4 μg/m3 for every kg/m2 of salt applied on the road surface during the winter season. Additional sensitivity studies showed that the accurate logging of salt applications is a prerequisite for predicting salt emissions, as well as good quality data on precipitation. It also highlights the need for more simultaneous measurements of salt loading together with ambient air concentrations to help improve model parameterisations of salt and moisture removal processes.

  14. 蓄盐沥青混合料除冰雪性能研究%Research on Deicing Performance of Asphalt Mixture Containing Salt

    Institute of Scientific and Technical Information of China (English)

    谭忆秋; 孙嵘蓉; 郭猛; 钟勇; 周水文

    2013-01-01

    In order to effectively evaluate the deicing performance of asphalt mixture containing salt and find out the deicing mechanism and effect of asphalt mixture containing salt, firstly the road performance of asphalt mixture containing salt was studied, then the system for testing adhesion between ice and asphalt mixture was developed, and the extreme fracture tensile and damage interface level were proposed to assess the adhesion between asphalt mixture and ice. The effect of grading types and temperature on adhesion was also studied. The deicing mechanism of asphalt mixture containing salt was studied with the freezing point test. The deicing effect of asphalt mixture containing salt was verified by indoor test and outdoor actual project. The results show that asphalt mixture containing salt can effectively decrease the adhesion between ice and mixture and the extreme fracture tensile of mixture containing salt is 27. 8% lower than that of ordinary mixture at -5 ℃ ; the open gradation asphalt mixture has better adhesion with ice than the dense gradation, and the adhesion ability increases with the increase of the nominal maximum aggregate size, or the decrease of the temperature, and the interface level decreases with the decrease of temperature; the road performance and deicing performance of asphalt pavement containing salt are good.%为了有效评价沥青路面除冰雪性能、揭示蓄盐沥青混合料除冰雪机理及效果,首先对蓄盐沥青混合料的路用性能进行了研究;其次开发了冰膜与沥青混合料表面粘结力测试系统,提出采用极限破坏拉力和破坏界面等级综合评价混合料与冰的粘结能力,分析了级配类型、温度对粘结能力的影响;并设计了冰点试验方法,研究了蓄盐沥青混合料除冰雪机理;最后通过室内试验和室外实体工程对除冰雪效果进行了验证.结果表明:蓄盐沥青混合料能有效降低混合料与冰之间的粘结力,-5℃时蓄盐混

  15. Deicing chemicals as source of constituents of highway runoff

    Science.gov (United States)

    Granato, G.E.

    1996-01-01

    The dissolved major and trace constituents of deicing chemicals as a source of constituents in highway runoff must be quantified for interpretive studies of highway runoff and its effects on surface water and groundwater. Dissolved constituents of the deicing chemicals-sodium chloride, calcium chloride, and premix (a mixture of sodium and calcium chloride)-were determined by analysis of salt solutions created in the laboratory and are presented as mass ratios to chloride. Deicing chemical samples studied are about 98 and 97 percent pure sodium chloride and calcium chloride, respectively: however, each has a distinct major and trace ion constituent signature. The greatest impurity in sodium chloride road sail samples was sulfate, followed by calcium, potassium, bromide, vanadium, magnesium, fluoride, and other constituents with a ratio to chloride of less than 0.0001 by mass. The greatest impurity in the calcium chloride road salt samples was sodium, followed by potassium, sulfate, bromide, silica, fluoride. strontium, magnesium, and other constituents with a ratio to chloride of less than 0.0001 by mass. Major constituents of deicing chemicals in highway runoff may account for a substantial source of annual chemical loads. Comparison of estimated annual loads and first flush concentrations of deicing chemical constituents in highway runoff with those reported in the literature indicate that although deicing chemicals are not a primary source of trace constituents, they are not a trivial source, either. Therefore, deicing chemicals should be considered as a source of many major and trace constituents in highway and urban runoff.

  16. Suppression of deicing salt corrosion of weathering steel bridges by washing

    Energy Technology Data Exchange (ETDEWEB)

    Hara, Shuichi [Investigation and Research Division, Sumitomo Metal Technology Inc., 1-8 Fuso-cho, Amagasaki, Hyogo 660-0891 (Japan)]. E-mail: hara-shu@smt-co.com; Miura, Masazumi [Development Division, Yon-den Consultant Co., 1007-3 Mure-cho Kida-gun, Kagawa 761-0121 (Japan); Uchiumi, Yasushi [Bridge Division, Kawada Industries Inc., 1-3-11 Takinogawa, Kita-ku, Tokyo 114-8562 (Japan); Fujiwara, Toshiaki [Takamatsu Engineering Office, Shikoku Regional Bureau, Japan Highway Public Co., 4-1-3 Asahi-cho, Takamatsu, Kagawa 760-0065 (Japan); Yamamoto, Masataka [Takamatsu Engineering Office, Shikoku Regional Bureau, Japan Highway Public Co., 4-1-3 Asahi-cho, Takamatsu, Kagawa 760-0065 (Japan)

    2005-10-01

    To elucidate the influences of deicing salts and high pressure (2-4 MPa) washing on the characteristics of the rust formed on weathering steel bridges, washing experiments have been carried out for three years. The rust was characterized by means of ion chromatography, X-ray diffraction and adsorption of N{sub 2}. The rust thickness was measured, and also the rust weight per unit area of the steel surface was measured. It was found that water-soluble chloride accelerated the rate of corrosion because the rust particles grow by the chloride ions and micro-pore structure of the rust appeared by the chloride ions. Washing with water suppressed corrosion owing to the disappearance of chloride ions.

  17. Salt on roads and the environment (VB)

    DEFF Research Database (Denmark)

    Hessberg, Philipp von; Jørgensen, Michael Søgaard

    2000-01-01

    This report descripes the extent of use of salt on roads in Denmark and the environmental consequences of this. Alternative strategies for reducing the risk of greasy roads and different ways of alleviating the vegetation are also discussed.The different consequences for the environment that this......This report descripes the extent of use of salt on roads in Denmark and the environmental consequences of this. Alternative strategies for reducing the risk of greasy roads and different ways of alleviating the vegetation are also discussed.The different consequences for the environment...... that this report discusses are:- The ground water.- Lakes and streams.- Plants and trees along roads.The consequences for the economy through usage of salt on roads has not been carried out....

  18. Salt on roads and the environment (VB)

    DEFF Research Database (Denmark)

    Hessberg, Philipp von; Jørgensen, Michael Søgaard

    2000-01-01

    This report descripes the extent of use of salt on roads in Denmark and the environmental consequences of this. Alternative strategies for reducing the risk of greasy roads and different ways of alleviating the vegetation are also discussed.The different consequences for the environment that this......This report descripes the extent of use of salt on roads in Denmark and the environmental consequences of this. Alternative strategies for reducing the risk of greasy roads and different ways of alleviating the vegetation are also discussed.The different consequences for the environment...... that this report discusses are:- The ground water.- Lakes and streams.- Plants and trees along roads.The consequences for the economy through usage of salt on roads has not been carried out....

  19. Durability of cracked fibre reinforced concrete exposed to freeze-thaw and deicing salt

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1998-01-01

    -thaw and deicing salt. The concrete has a water-powder ratio of 0.38 including both fly ash and silica fume. Both steel fibres (ZP, 0.4 vol%) and polypropylene fibres (PP, 1 vol%) are used as well as main reinforcement. The freeze-thaw test emphasizes the need for a critical evaluation of the mix design and mixing......Durability studies are carried out by subjecting FRC-beams to combined mechanical and environmental load. Mechanical load is obtained by subjecting beams to 4-point bending until a predefined crack width is reached. Specimens sawn from the beams after unloading are exposed to freeze...... methods when designing FRC-structures. The scaling is increased by a factor 5 to 10 when adding fibres to the concrete while the air content is below 4% by volume. The variation of the scaling increases when adding fibres. Capillary water uptake in uncracked specimens of FRC was 20-30% higher at 1°C than...

  20. 化学融雪剂对小球藻生长和生理特性的影响%The effect of deicing salt on growth and physiological characteristics of Chlorella vulgaris

    Institute of Scientific and Technical Information of China (English)

    胡水; 李法云; 范志平; 程志辉; 高群; 张营

    2013-01-01

    寒冷地区道路表面除雪化冰使用的化学融雪剂随着地表径流进入水体,将影响水生态系统中的水生生物正常生长,并破坏水生态系统平衡.为研究化学融雪剂醋酸钾盐对水生生物的毒性效应,分析了不同浓度有机融雪剂醋酸钾盐对小球藻生长特征、藻细胞光合色素、蛋白质及多糖含量的影响.结果表明:浓度为2 g·L-1的有机融雪剂对小球藻生长无明显影响,当融雪剂浓度为4 g·L-1时,小球藻细胞生长表现出明显抑制效应,且抑制效应随融雪剂浓度增加呈显著上升趋势(P<0.01);当融雪剂浓度小于4g·L-1时,有机融雪剂对小球藻细胞内叶绿素a合成有明显促进作用,但随着有机融雪剂处理浓度升高,藻细胞内叶绿素a含量逐渐下降.当融雪剂的处理浓度大于4 g·L-1的时候,藻细胞内蛋白质和多糖含量与对照组相比呈显著下降趋势(P<0.01),抑制水体中小球藻正常生长繁殖并破坏藻体细胞,最终导致水生态系统平衡被破坏.%Deicing salt was applied for clearing ice and snow on road in winter and entered into river with the surface runoff,so it affected the growth of aquatic organism and broke the equilibrium of aquatic ecosystem.In order to study the toxic effect of organic deicing salt on aquatic organisms,the effects of organic deicing salt on the growth,the content change of photosynthesis pigments,protein and polysaccharides of Chlorella vulgaris were analyzed.The results show that there is no significant effect for the growth of Chlorella vulgaris when the deicing salt (potassium acetate)concentration is 2 g· L-1.However,there is a significant inhibitory effect on the cell growth of Chlorella vulgaris when it is 4 g ·L-1,and the inhibitive effect of deicing salt significantly increases (P < 0.01) with the increase of the concentrations.There is the significant stimulative effect on biosynthesis of chlorophyll (a) in a cell of Chlorella vulgaris

  1. Transport of road salt contamination in karst aquifers and soils over multiple timescales.

    Science.gov (United States)

    Robinson, Heather K; Hasenmueller, Elizabeth A

    2017-12-15

    Road deicing has caused widespread environmental Na(+) and Cl(-) release for decades, yet the transport and retention of these contaminants in karst aquifers and soils are poorly understood. We examined the transport dynamics of Na(+) and Cl(-) from road salt in shallow groundwater during flooding and over seasonal timescales by intensively monitoring an urban and a rural karst spring over approximately 2 years. Furthermore, we used a 20-year dataset for the rural spring to determine how salt retention affected long-term geochemical trends in the shallow groundwater. Salt transport was governed by hydrologic pathways through karst aquifers: during winter and early spring floods, flow through preferential pathways rapidly transported salty meltwater or stormwater over hours to days, while the remaining salt-contaminated water moved diffusely through the rock matrix on timescales of months to years. Flood hydrograph separations revealed that event water constituted 61.2% of stormflow on average at the urban spring, leading to more extreme variability in salt concentrations during flooding and throughout the year. This variability indicates that baseflow contributions to urban streams overlying karst aquifers with preferential flowpaths are likely less effective at buffering salt concentrations. In contrast, salt concentrations were less variable in the baseflow-dominated rural spring (28.7% event water). Furthermore, salt was episodically released from soils to shallow groundwater throughout the year during first flush events. A Cl(-) mass balance indicates that Cl(-) applied during previous winters persists within the springs' recharge basins for more than a year, raising baseline concentrations as road salt is introduced faster than it can be flushed from the basin. Inter-annual salt retention by soils or slow groundwater movement likely caused significant Cl(-) and specific conductivity (SpC) increases at the rural spring from 1996 to 2016. Accumulation of salt in

  2. Geospatial Estimates of Road Salt Usage Across a Gradient of Urbanizing Watersheds in Southern Ontario:Thesis for Masters in Spatial Analysis (MSA)

    Science.gov (United States)

    Giberson, G. K.; Oswald, C.

    2015-12-01

    In areas affected by snow, chloride (Cl) salts are widely used as a de-icing agent to improve road conditions. While the improvement in road safety is indisputable, there are environmental consequences to local aquatic ecosystems. In many waterways, Cl concentrations have been increasing since the early 1990s, often exceeding national water quality guidelines. To determine the quantity of Cl that is accumulating in urban and urbanizing watersheds, accurate estimates of road salt usage at the watershed-scale are needed. The complex jurisdictional control over road salt application in southern Ontario lends itself to a geospatial approach for calculating Cl inputs to improve the accuracy of watershed-scale Cl mass balance estimates. This study will develop a geospatial protocol for combining information on road salt applications and road network areas to refine watershed-scale Cl inputs, as well as assess spatiotemporal patterns in road salt application across the southern Ontario study region. The overall objective of this project is to use geospatial methods (predominantly ArcGIS) to develop high-accuracy estimates of road salt usage in urbanizing watersheds in southern Ontario. Specifically, the aims will be to map and summarize the types and areas ("lane-lengths") of roadways in each watershed that have road salt applied to them, to determine the most appropriate source(s) of road salt usage data for each watershed, taking into consideration multiple levels of jurisdiction (e.g. municipal, regional, provincial), to calculate and summarize sub-watershed and watershed-scale road salt usage estimates for multiple years, and to analyze intra-watershed spatiotemporal patterns of road salt usage, especially focusing on impervious surfaces. These analyses will recommend areas of concern exacerbated by high-levels of road salt distribution; recommendations around modifying on-the-ground operations will be the next step in helping to correct these issues.

  3. 融雪剂路面上汽车制动距离计算模型%Calculation model of automobile braking distance on pavement with deicing salt

    Institute of Scientific and Technical Information of China (English)

    李志鹏; 彭涛; 王茜; 詹长书

    2012-01-01

    The forces conditions of front and rear wheels during automobile braking process were analyzed, and a mathematical model of automobile braking distance and road adhesion coefficient was established. Braking tests on ice-snow-covered pavement and the pavement after using deicing salt were carried out, and the braking distances under different primary braking speeds were calculated by using MATLAB software. Test result shows that on ice-snow-covered pavement, when the primary braking speeds are 10.8, 24.4, 31.4 km . h-1 respectively, the braking distances are 2. 959, 18. 378, 26. 264 m respectively. On the pavement after using deicing salt, when the primary braking speeds are 11.0, 22.9, 31.0 km . h 1 respectively, the braking distances are 2.430, 13.766, 18.860 m respectively. After using deicing salt, the adhesion coefficient of the pavement increases significantly, and the test braking distance decreases by 25%-28%, the simulation braking distance decreases by about 30G and is close to the test value. So the calculation model is feasible. 7 tabs, 4 figs, 14 refs.%分析了汽车制动过程前、后轮受力状况,建立了汽车制动距离与路面附着系数的数学模型。在冰雪路面和使用融雪剂路面上进行了制动试验,应用MATLAB软件仿真计算了汽车在不同制动初速度下的制动距离。试验结果表明:在冰雪路面上,当汽车制动初速度分别为10.8、24.4、31.4km·h-1时,制动距离分别为2.959、18.378、26.264m;在使用融雪剂路面上,当汽车制动初速度分别为11.0、22.9、31.0km·h-1时,制动距离分别为2.430、13.766、18.860m。使用融雪剂后,附着系数明显提高,测试制动距离减小了25%~289/6,仿真计算制动距离减小了约30%,两者接近,因此,计算模型可靠。

  4. Effects of Deicing Salt Stress on Photosynthetic Characteristics of Rosa chinensis%融雪剂胁迫对月季光合特性的影响

    Institute of Scientific and Technical Information of China (English)

    茹豪; 张建军; 徐佳佳; 王清玉; 黄明

    2012-01-01

    An experiment was conducted to study the effects of deicing salt stress on urban green plants. The photosynthetic characteristics of one-year-old seedlings of Rosa chinensis were determined under deicing salt stress of different concentrations (0, 20, 50, 80, 120g · m-2). Results showed that the net photosynthetic rate, transpiration rate, and stomatal conductance of the leaves of R. chinensis declined markedly with increasing deicing salt concentration and prolonged stress time. Under the stress of LBR-4 deicing salt, the water use efficiency declined markedly, and intercellular CO2 concentration and stomatal limitation decreased after an initial increase. However, under the stress of JLR-01 deicing salt, water use efficiency, stomatal limitation and intercellular CO, concentration increased during the first week and decreased during the second week, and stomatal conductance decreased after an initial increase. Under the same stress concentration, it chinensis were damaged by LBR-4 deicing salt more badly than by JLR-01. R. chinensis seedlings could endure threats of less than 20 g · m-2 deicing salt, and they could recover after removing deicing salt. However, when R. chinensis seedlings in conditions of more than 50 g · m-2, they would be destroyed in a short period of time and never restored normal growth. The effects of deicing salt on R. chinensis seedlings not only result from Cl- but also from other trace metals-%为了探讨融雪剂对城市绿化植物的影响,以1年生月季(Rosa chinensis)幼苗为试材,在融雪剂施用量为0、20、50、80、120g · m-25种条件下,研究了融雪剂对月季光舍特性的影响.结果表明:随着融雪剂施用量的增加和胁迫时间的延长,月季叶片净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(G(0))明显下降.施用融雪剂LBR -4后,月季的水分利用效率(Wu,E)明显下降,胞间二氧化碳摩尔分数(Ci)和气孔限制值(L(O))先降后升;在施用融雪剂JLR-01后的第1

  5. Deicing investigation of a CNFP-based high-efficiency self-deicing system

    Science.gov (United States)

    Zhang, Qiangqiang; Hui, Li

    2012-04-01

    A self-deicing road system consisting of a carbon nano-fiber polymer (CNFP) thermal source, an AlN-ceramic insulated encapsulation layer, a multiwall carbon nanotube (MWCNT)/cement-based thermal conduction layer and a thermally insulated substrate was proposed in this study. The effects of ambient temperature, heat flux density and ice thickness on the deicing of the self-deicing system were investigated in chilled. The efficiency, repeatability, cost and feasibility of the self-deicing road system in both deicing and snow-melting applications were analyzed. Indices for evaluating the deicing or snow-melting performance of the self-deicing road system were adopted in this study.

  6. 公路用融雪剂应用研究现状与发展趋势%Current Situation of Application and Study of Deicing Salt for Highway and Development Tendency

    Institute of Scientific and Technical Information of China (English)

    刘楠

    2012-01-01

    概述了国内外融雪剂应用研究现状与发展趋势,为科学合理选用融雪剂技术提供参考。%Current situation of application and study of deicing salt for highway and development tendency are summarized, providing references for scientific and reasonable application of deicing salt.

  7. Effects of deicing salt on the vitality and health of two spruce species, Picea abies Karst., and Picea glehnii Masters planted along roadsides in northern Japan.

    Science.gov (United States)

    Kayama, M; Quoreshi, A M; Kitaoka, S; Kitahashi, Y; Sakamoto, Y; Maruyama, Y; Kitao, M; Koike, T

    2003-01-01

    In northern Japan, the growth of Picea abies Karst., and Picea glehnii Masters, which have been planted along the highways, is often suppressed due to several environmental stresses. To examine the adverse effects of deicing salt, the primary source of stress,we measured needle life span, photosynthetic capacity, and water potential and transpiration rate of the two spruce species at a site with damaged trees, near the roadside and a site with healthy trees, located far from the highway. Results from the analysis showed large amounts of sodium and chlorine in the soil and snow at the damaged site. These elements had accumulated in the needles of the spruce. Moreover, physiological traits of the spruce, at the damaged site were also affected. Therefore, we concluded that poor physiological traits might be attributed to an accumulation of deicing salt in the needles, resulting in the suppression of tree growth.

  8. Toxicity of road salt to Nova Scotia amphibians

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Sara J. [Department of Biology, Saint Mary' s University, 923 Robie Street, Halifax, NS, B3H 3C3 (Canada); Russell, Ronald W. [Department of Biology, Saint Mary' s University, 923 Robie Street, Halifax, NS, B3H 3C3 (Canada)], E-mail: ron.russell@smu.ca

    2009-01-15

    The deposition of chemical pollutants into roadside wetlands from runoff is a current environmental concern. In northern latitudes, a major pollutant in runoff water is salt (NaCl), used as de-icing agents. In this study, 26 roadside ponds were surveyed for amphibian species richness and chloride concentration. Acute toxicity tests (LC{sub 50}) were performed on five locally common amphibian species using a range of environmentally significant NaCl concentrations. Field surveys indicated that spotted salamanders (Ambystoma maculatum) and wood frogs (Rana sylvatica) did not occupy high chloride ponds. American toads (Bufo americanus) showed no pond preference based on chloride concentration. Acute toxicity tests showed spotted salamanders and wood frogs were most sensitive to chloride, and American toads were the least. Spring peepers (Pseudacris crucifer) and green frogs (Rana clamitans) showed intermediate sensitivities. We concluded that chloride concentrations in ponds due to application of de-icing salts, influenced community structure by excluding salt intolerant species. - Salt toxicity is presented as a mechanism affecting the distribution of amphibians and structure of amphibian communities in roadside wetlands.

  9. Optimizing a Test Method to Evaluate Resistance of Pervious Concrete to Cycles of Freezing and Thawing in the Presence of Different Deicing Salts

    Directory of Open Access Journals (Sweden)

    Chehong Tsang

    2016-10-01

    Full Text Available The lack of a standard test method for evaluating the resistance of pervious concrete to cycles of freezing and thawing in the presence of deicing salts is the motive behind this study. Different sample size and geometry, cycle duration, and level of submersion in brine solutions were investigated to achieve an optimized test method. The optimized test method was able to produce different levels of damage when different types of deicing salts were used. The optimized duration of one cycle was found to be 24 h with twelve hours of freezing at −18 °C and twelve hours of thawing at +21 °C, with the bottom 10 mm of the sample submerged in the brine solution. Cylinder samples with a diameter of 100 mm and height of 150 mm were used and found to produce similar results to 150 mm-cubes. Based on the obtained results a mass loss of 3%–5% is proposed as a failure criterion of cylindrical samples. For the materials and within the cycles of freezing/thawing investigated here, the deicers that caused the most damage were NaCl, CaCl 2 and urea, followed by MgCl 2 , potassium acetate, sodium acetate and calcium-magnesium acetate. More testing is needed to validate the effects of different deicers under long term exposures and different temperature ranges.

  10. Optimizing a Test Method to Evaluate Resistance of Pervious Concrete to Cycles of Freezing and Thawing in the Presence of Different Deicing Salts.

    Science.gov (United States)

    Tsang, Chehong; Shehata, Medhat H; Lotfy, Abdurrahmaan

    2016-10-28

    The lack of a standard test method for evaluating the resistance of pervious concrete to cycles of freezing and thawing in the presence of deicing salts is the motive behind this study. Different sample size and geometry, cycle duration, and level of submersion in brine solutions were investigated to achieve an optimized test method. The optimized test method was able to produce different levels of damage when different types of deicing salts were used. The optimized duration of one cycle was found to be 24 h with twelve hours of freezing at -18 °C and twelve hours of thawing at +21 °C, with the bottom 10 mm of the sample submerged in the brine solution. Cylinder samples with a diameter of 100 mm and height of 150 mm were used and found to produce similar results to 150 mm-cubes. Based on the obtained results a mass loss of 3%-5% is proposed as a failure criterion of cylindrical samples. For the materials and within the cycles of freezing/thawing investigated here, the deicers that caused the most damage were NaCl, CaCl 2 and urea, followed by MgCl 2 , potassium acetate, sodium acetate and calcium-magnesium acetate. More testing is needed to validate the effects of different deicers under long term exposures and different temperature ranges.

  11. Numerical study of the thermal behavior of a new deicing road structure design with energy harvesting capabilities

    Science.gov (United States)

    Le Touz, Nicolas; Dumoulin, Jean

    2015-04-01

    Facing the heavy organisational, financial and environmental constraints imposed by usual winter maintenance salting operations, pavement engineers have been led to look for alternative solutions to avoid ice or snow deposit at pavements surface. Among the solutions, one is self-de-icing heating pavements, for which two technologies have been developed so far: one is based on embedded coils circulating a heated calorific fluid under the pavement surface; the other one relies on the use of embedded resistant electric wires. The use and operation of such systems in the world is still limited and was only confined to small road stretches or specific applications, such as bridges which are particularly sensitive to frost. One of the most significant "coil technology" example in Europe is the SERSO-System (Solar Energy recovery from road surfaces) built in 1994, on a Switzerland bridge. Many of these experiences are referenced in the technical literature, which provides state-of-the art papers (see for instance Eugster) and useful detailed information dealing with the construction and operational management of such installation. The present study is taking part of the Forever Open Road Concept addressed by the R5G: 5th Generation Road [1], one of the major project supported by IFSTTAR. It considers a different design of self-de-icing road that simplify its mode of construction and maintenance, compared to the two technologies mentioned above. It should also be noted that similar to pavements instrumented with coils, such structure could be used in the reversible way to capture the solar energy at the pavement surface during sunny days and store it, to either warm the pavement at a later stage or for exogenous needs (e.g. contribution to domestic hot water). To complete our study we also considered the use of semi-transparent pavement course wearing in place of the traditional opaque one. In the present study, a 2D model was developed using FEM approach. It combines 2

  12. Effect of deicing salts on urban soils and health status of roadside trees in the Opole region.

    Science.gov (United States)

    Czerniawska-Kusza, Izabela; Kusza, Grzegorz; Duzyński, Mariusz

    2004-08-01

    This article reports on a study whose aim was to evaluate the impact of snow removal salts on urban soil properties and the health of roadside trees. The evaluation was done by chemical analyses of soil samples and plant matter combined with toxicity testing, performed with a Protoxkit F, a protozoan microbiotest. Samples were collected at 45 locations on three main roads in the town of Opole (Poland). The roads differed in the snow removal technology and amount of chemical substances (mostly NaCl) used on them during the winter. The study showed that when soil was exposed to a high level of NaCl, it tended to be more alkaline and also exhibited increased content of Na(+) and Cl(-). The toxic effects of the soil extract on protozoa appeared at 26.0 mg Na(+)/100 g soil dry mass (s.d.m.) and 12.0 mg Cl(-)/100 g s.d.m., whereas salt injury symptoms (chlorosis and necrosis of the edge of leaf blades) appeared at 13.2 mg Na(+)/100 g s.d.m. and 3.9 mg Cl(-)/100 g s.d.m., becoming more severe at 26.0 mg Na(+)/100 g s.d.m. and 12.0 mg Cl(-)/100 g s.d.m. because of extensive necrosis and defoliation. The lysimetric experiment, which was used to test soil samples collected from the city park area, indicated that salt plays a significant role in the pollution of soil in urban areas, with the least toxic salt being CaCl(2).

  13. Numerical investigation of road salt impact on an urban wellfield.

    Science.gov (United States)

    Bester, M L; Frind, E O; Molson, J W; Rudolph, D L

    2006-01-01

    The impact of road salt on a wellfield in a complex glacial moraine aquifer system is studied by numerical simulation. The moraine underlies an extensive urban and industrial landscape, which draws its water supply from >20 wellfields, several of which are approaching or have exceeded the drinking water limit for chloride. The study investigates the mechanisms of road salt infiltration, storage, and transport in the subsurface and assesses the effectiveness of mitigation measures designed to reduce the impact. The three-dimensional transport model accounts for increases in salt loading, as well as growth of the urbanized area and road network over the past 50 years. The simulations, which focus on one impacted wellfield, show chloride plumes originating mainly at arterial roads and migrating through aquitard windows into the water supply aquifers. The results suggest that the aquifer system contains a large and heterogeneously distributed mass of chloride and that concentrations in the aquifer can be substantially higher than the concentrations in the well water. Future impact scenarios indicate that although the system responds rapidly to reductions in salt loading, the residual chloride mass may take decades to flush out, even if road salting were discontinued. The implications with respect to urban wellfields in typical snow-belt areas are discussed.

  14. Permeable Asphalt: A New Tool to Reduce Road Salt Contamination of Groundwater in Urban Areas.

    Science.gov (United States)

    Dietz, Michael E; Angel, Derek R; Robbins, Gary A; McNaboe, Lukas A

    2016-08-30

    Chloride contamination of groundwater in urban areas due to deicing is a well-documented phenomenon in northern climates. The objective of this study was to evaluate the effects of permeable pavement on degraded urban groundwater. Although low impact development practices have been shown to improve stormwater quality, no infiltration practice has been found to prevent road salt chlorides from entering groundwater. The few studies that have investigated chlorides in permeable asphalt have involved sampling directly beneath the asphalt; no research has looked more broadly at surrounding groundwater conditions. Monitoring wells were installed upgradient and downgradient of an 860 m(2) permeable asphalt parking lot at the University of Connecticut (Storrs, Connecticut). Water level and specific conductance were measured continuously, and biweekly samples were analyzed for chloride. Samples were also analyzed for sodium (Na), calcium (Ca), and magnesium (Mg). Analysis of variance analysis indicated a significantly (p asphalt in impacted urban environments with high ambient chloride concentrations can be beneficial to shallow groundwater quality, although these results may not be generalizable to areas with low ambient chloride concentrations.

  15. 氯盐型融雪剂碳钢腐蚀性的测定新方法%Determination for Chloride Salt -Type of Deicing Salt Carbon Steel Causticity

    Institute of Scientific and Technical Information of China (English)

    王树轩; 李宁; 李波; 李玉龙

    2012-01-01

    文章考虑了融雪剂使用过程的通气状态,提出测定氯盐型融雪剂碳钢腐蚀率的新方法—充氧测定法.并比较了充氧与非充氧条件下,NaCl、MgCl2和CaCl2三种融雪剂对碳钢的腐蚀性.在充氧条件下,141 h三种融雪剂的失重率相差不大,普遍大于非充氧状态下553 h的失重率,553 h时,当浓度低于4%,失重率CaCl2> MgCl2> NaCl,浓度大于4%时,失重率NaCl> CaCl2> MgCl2.并利用灰色系统理论建模,预测分析CaCl2对碳钢腐蚀性.在553 h时,非充氧条件下,灰色预测效果好,误差<±10.%In this paper, after considering the aeration state of using deicing salt, we proposed a new method of measuring for chloride salt - type of deicing salt carbon steel causticity by oxygenizing mensuration. And compare with the condition of oxygenation and dis - oxygenation. The causticity for carbon steel from the three kind of deicing salt were NaCl, MgCl2 and CaCl2- In general , the rate of weight loss of these kind of deicing salt have less difference in the condition of oxygenation with 141 h, greater than the condition of dis - oxygenation with 553 h. When the time is 553 h and the conch is lower than 4% , the rate of weight loss is: CaCl2 > MgCl2 > NaCl; and when the conch is higher than 4% , the rate of weight loss is: NaCl > CaCl, > MgCl2. We predicted and analyzed the carbon steel causticity from CaCl2 with Grey system theory model. In the condition of dis - oxygenation with 553 h, the impact of grey predicting is very good, and the inaccuracy is lower than ± 10.

  16. Cumulative effects of road de-icing salt on amphibian behavior

    OpenAIRE

    Denoël, Mathieu; Bichot, Marion; Ficetola, G. Francesco; Delcourt, Johann; Ylieff, Marc; Kestemont, Patrick; Poncin, Pascal

    2010-01-01

    Despite growing evidence of the detrimental effect of chemical substances on organisms, limited research has focused on changes in behavioral patterns, in part due to the difficulties to obtain detailed quantitative data. Recent developments in efficient computer-based video analyses have allowed testing pesticide effects on model species such as the zebrafish. However, these new techniques have not yet been applied to amphibians and directly to conservation issues, i.e. to assess toxicologic...

  17. 聚乙烯醇纤维强化水泥基复合材料的抗盐冻性能%Deicing salt resistance of PVA fiber reinforced cementitious composite

    Institute of Scientific and Technical Information of China (English)

    刘曙光; 闫敏; 闫长旺; 郭荣跃

    2012-01-01

    通过氯盐环境中的快速冻融试验研究了纤维体积率、冻融循环次数、粉煤灰、硅粉对聚乙烯醇(PVA)纤维水泥基复合材料抗盐冻性能的影响。通过扫描电镜观察内部微观结构随盐冻作用的变化规律、PVA纤维在水泥基体中分布情况和界面结合状况。试验结果表明:PVA纤维的掺入可明显改善水泥基复合材料的抗盐冻性能;PVA纤维在基体中分散性较好,且与水泥基体界面结合状况较好;而粉煤灰、硅粉的掺入未明显改善PVA纤维水泥基复合材料的抗盐冻性能。%The effects of the fiber volume ratio,the freezing-deicing cycle number,the coal fly ash,and the silicon powder on the resistance against deicing salt of the polyvinyl alcohol(PVA) fiber reinforced cementitious composite were investigated by the accelerated preezing-deicing cycle test under the chloride environment.The change of the microstructure along with the action of the chloride and the freezing-deicing,the distribution of the PVA fiber in the cement matrix and the interface binding were observed by a scan electronic microscope.The test result show that adding PVA fiber into cement improves significantly the freezing-deicing resistance of the cementitious composite under the chloride environment.The PVA fiber is well distributed in the matrix and well bound with the cement in the interface.Adding the coal fly ash or silicon powder do not much improve the deicing salt resistance of the composite.

  18. Long-term dynamics of anthropogenic solonetzicity in soils of the Eastern okrug of Moscow under the impact of deicing salts

    Science.gov (United States)

    Nikiforova, E. M.; Kasimov, N. S.; Kosheleva, N. E.

    2017-01-01

    The long-term dynamics of the anthropogenic soil solonetzicity under the impact of applied deicing salts were studied in the Eastern administrative okrug (EAO) of Moscow. The composition and amount of the applied agents and distribution patterns of sodium in snowmelt water and in soils of different land-use zones were analyzed. The maps of soil solonetzization in the EAO in 1989, 2005, and 2010 were compiled, and the degree of degradation of the soil cover was evaluated. It was shown that the contrast of the technogenic anomalies in the content of exchangeable sodium and the size of these anomalies in soils of the okrug increase with time. In 21 years, the mean content of exchangeable sodium in the surface soil layer increased from 0.38 to 0.80 cmol(equiv.)/kg, and the degree of solonetzicity (as judged from the exchangeable sodium percentage) increased from 3.1 to 7.2%. In 2005-2010, the rates of sodium accumulation in the soil adsorption complex were twice as high as those in 1989-2005.

  19. 高效环保融雪剂的研究%The Research of Efficient and Environmentally Friendly Deicing

    Institute of Scientific and Technical Information of China (English)

    梁西良; 崔宝军; 白雪峰; 王旭; 李猛

    2014-01-01

    With economic development of our country, road transportation has become the vital lifeline of the national economic. Therefore, to ensure the urban roads and highways smooth has become an important issue closely related to socioeconomic. Winter weather is the biggest barrier for smooth traffic, thus deicing technology is imperative. Using deicing salt is the most widely used method, but the classification is extensive. In this paper, the differences between chlorine deicing salts and organic salts is compared and the one does the less harm to tires as well as the environment is investigated.%随着我国经济的发展,公路运输已成为经济发展的主要命脉。所以,保证城市道路与高速公路交通顺畅,已成为与社会经济紧密关联的重要问题。其中冰雪天气是保障交通畅通的“大敌”,发展道路除冰雪技术势在必行,采用融雪剂是最为广泛的应用方法。融雪剂的分类较多。综述了氯盐类和有机盐类融雪剂的不同,综合选出对环境和轮胎损伤最小的融雪剂。

  20. Prevention and Monitoring of Secondary Deicing Salt Soil at Tian' anmen%天安门融雪剂次生盐害土壤的防治与监测

    Institute of Scientific and Technical Information of China (English)

    郭城; 孙向阳; 郝利锋; 张强; 罗丹

    2012-01-01

    为了减轻氯盐类融雪剂对生态环境造成的污染,节约由此产生的土壤治理修复费用,针对天安门广场油松土壤的融雪剂次生盐害问题,采用铺设吸附层的方式进行了土壤防治工作.吸附层由海泡石绒、沸石、腐殖质3种吸附性材料组成,具有吸附融雪剂中Na+、Cl-等无机离子的作用,分别对铺设吸附层前后的土壤采样分析.结果表明:吸附层对土壤的pH、EC值有明显缓冲作用,可有效吸附融雪剂中Na+、Cl-,但对Cl-可能存在吸附量上限.后续的土壤监测表明,天安门广场地形及车辆行人等因素对土壤EC值有一定影响.吸附层能够吸收氯盐类融雪剂中的无机盐离子成分,在一定范围内可有效防止氯盐类融雪剂对油松种植土壤造成的次生盐害问题,改变污染状况.%In order to reduce the pollution caused by chlorine deicing salt on the ecological environment, and save the costs of soil remediation and repair, prevention and control of soil was carried out with a kind of adsorbed layer of deicing salt adsorption, which was made up of adsorption materials, such as sepiolite cashmere, zeolite and humus, aiming at the Tian' anmen Square in Pinus tebulaeformis planting soil secondary salinity problems of deicing salt. The laying of adsorption layer and soil were sampled and analyzed. The results showed that, the adsorption layer would absorb Na+, Cl- from the deicing salt effectively, which also had an obviously buffer action on pH, EC value of soil. However, a maximum adsorption capacity might exist when Cl- was absorbed. The follow-up soil monitoring showed that, pedestrians and traffic on Tiananmen Square and other factors had certain effect on soil EC value. The adsorption layer would absorb the inorganic salt ion composition in the chlorine deicing salt, and it would effectively prevent the secondary salt damage caused by the chlorine deicing salt on Pinus tabulaeformis planting soil, to change the

  1. 氯盐融雪剂对4种地被植物种子萌发的影响%Effect of chloride deicing salts on seed germination of four ground covers species

    Institute of Scientific and Technical Information of China (English)

    杨冬; 周广柱

    2015-01-01

    The effects of deicing salts on seed germination and growth of shoots and roots of four kinds of ground covers (Poa pratensts, Bromus inermis Layss,Coreopsis basalis,Cosmos bipinnatus Cav. ) were studied. The length of roots and shoots of ground covers were also determined in this paper. The results showed that the inhibition effect on seed germination and growth response in the four kinds of ground covers was increased with increasing concentration of deicing salts. Cosmos bipinnatus Cav.showed the highest tolerance to deicing salts, followed by Bromus inermis Layss, Coreopsis basalis and Poa pratensis. The critical value of tolerance to deicing salts were 14.69 g/L, 10.04 g/L, 7.38 g/L and 7.31 g/L forCosmos bipinnatus Cav, Bromus inermis Layss, Coreopsis basalis and Poa pratensis,respectively and the maximum value were 21.08 g/L, 16.51 g/L, 14.67 g/L and 13.50 g/L, respectively.%以草地早熟禾、无芒雀麦、金鸡菊、波斯菊4种地被植物种子为研究材料,探讨不同浓度氯盐类融雪剂对其发芽的影响。结果表明:随着融雪剂浓度的增加,4种地被植物种子萌发、幼芽、幼根生长受到的抑制作用增强。4种地被植物对融雪剂胁迫的耐受能力大小依次为波斯菊>无芒雀麦>金鸡菊>草地早熟禾,耐受临界值分别为14.69 g/L、10.04 g/L、7.38 g/L和7.31 g/L,极限值分别为21.08 g/L、16.51 g/L、14.67 g/L和13.50 g/L。

  2. Long-term trends in sodium and chloride in the Mohawk River, New York: the effect of fifty years of road-salt application.

    Science.gov (United States)

    Godwin, K S; Hafner, S D; Buff, M F

    2003-01-01

    Ecological studies have demonstrated the adverse effects of road-salt, primarily NaCl, on water quality, flora, and fauna. In this study, we quantified changes in ionic composition and solute flux of water draining the Mohawk River Basin (9103 km(2)) in New York State, from 1952 to 1998. Using various statistical, graphical, and modeling techniques, we showed that concentrations ofNa+ and Cl- have increased by 130 and 243%, respectively, while other constituents have decreased or remained constant. The use of de-icing salt on roads within the watershed, which we estimate at 39 kg km(-2) day(-1), appears to be the primary mechanism responsible for reported increases, accounting for the increase in NaCl export from 16 to 46 kg km(-2) day(-1) over the 47-year period.Moreover, despite population decline within this rural upstate watershed, increased environmental stewardship, and The Clean Water Act, concentrations of Na+ and Cl- still increased during the 1990s.

  3. Legacy of road salt: Apparent positive larval effects counteracted by negative postmetamorphic effects in wood frogs.

    Science.gov (United States)

    Dananay, Kacey L; Krynak, Katherine L; Krynak, Timothy J; Benard, Michael F

    2015-10-01

    Road salt runoff has potentially large effects on wetland communities, but is typically investigated in short-term laboratory trials. The authors investigated effects of road salt contamination on wood frogs (Rana sylvatica) by combining a field survey with 2 separate experiments. The field survey tested whether wood frog larval traits were associated with road salt contamination in natural wetlands. As conductivity increased, wood frog larvae were less abundant, but those found were larger. In the first experiment of the present study, the authors raised larvae in outdoor artificial ponds under 4 salt concentrations and measured larval vital rates, algal biomass, and zooplankton abundance. Salt significantly increased larval growth, algal biomass, and decreased zooplankton abundance. In the second experiment, the authors raised larvae to metamorphosis in the presence and absence of salt contamination and followed resulting juvenile frogs in terrestrial pens at high and low densities. Exposure to road salt as larvae caused juvenile frogs to have greater mortality in low-density terrestrial environments, possibly because of altered energy allocation, changes in behavior, or reduced immune defenses. The present study suggests that low concentrations of road salt can have positive effects on larval growth yet negative effects on juvenile survival. These results emphasize the importance of testing for effects of contaminants acting through food webs and across multiple life stages as well as the potential for population-level consequences in natural environments.

  4. Effect of deicing salts on seed germination and growth of three cool-season turfgrass species%融雪剂对3种冷季型草坪草种子萌发和幼苗生长的影响

    Institute of Scientific and Technical Information of China (English)

    张营; 李法云; 荣湘民; 孙婷婷; 李霞; 程志辉

    2012-01-01

    The effects of two typical deicing salts (mass concentration of NaCl in No. 1 deicing salt was 45.2%, in No. 2 deicing salt 54.6% ) on seed germination and growth of shoots and roots of three kinds of cool-season turfgrasses (Poa pratensis cv. Merit, Lolium perenne cv. Green Emerald and Trifolium repens cv. Riverdel) were studied. The length of roots and shoots, relative water content, relative permeability of plasma membrane, malondialdehyd (MDA) content and peroxidases(POD) activity of turfgrass seedlings were also determined in this paper. The results showed that the inhibition effect on seed germination and growth response in the three kinds of turfgrasses was increased with increasing concentration of deicing salts. Compared with No. 1 deicing salt, the inhibition effect of No. 2 deicing salt was stronger. Lolium perenne showed the highest tolerance to deicing salts, followed by Poa pratensis and Trifolium repens. The critical value of tolerance to deicing salts were 6.25-9.61 g/L, 4.99-6.17 g/L and 1.97-3.11 g/L for Lolium perenne, Poa pratensis and Trifolium repens, respectively and the maximum value were 12.89-16.85 g/L, 9.79-12.62 g/L and 5.71-8.26 g/L, respectively. The deicing salts mainly inhibited water absorption, disturbed membrane function and induced MDA accumulation via the effect of osmotic and ion toxicity, and POD enzyme of the three kinds of turfgrass seedlings provided some protection against the dcicing salt stress.%以早熟禾(Poa pratensis cv.Merit)、黑麦草(Lolium perenne cv.Green Emerald)和白三叶(Trifolium repens cv.Riverdel)3种冷季型草坪草为材料,探讨2种典型融雪剂(1号融雪剂含NaCl 45.2%,2号融雪剂含NaCl54.6%)对其种子萌发、幼芽和幼根生长的影响,并测定幼苗生长过程中含水量、质膜相对透性、丙二醛含量及过氧化物酶(POD)活性.结果表明:随着融雪剂浓度的增加,3种草坪草种子萌发和幼苗生长受到的抑制作用增强,2号融雪剂对草坪

  5. Estimating Concentrations of Road-Salt Constituents in Highway-Runoff from Measurements of Specific Conductance

    Science.gov (United States)

    Granato, Gregory E.; Smith, Kirk P.

    1999-01-01

    Discrete or composite samples of highway runoff may not adequately represent in-storm water-quality fluctuations because continuous records of water stage, specific conductance, pH, and temperature of the runoff indicate that these properties fluctuate substantially during a storm. Continuous records of water-quality properties can be used to maximize the information obtained about the stormwater runoff system being studied and can provide the context needed to interpret analyses of water samples. Concentrations of the road-salt constituents calcium, sodium, and chloride in highway runoff were estimated from theoretical and empirical relations between specific conductance and the concentrations of these ions. These relations were examined using the analysis of 233 highwayrunoff samples collected from August 1988 through March 1995 at four highway-drainage monitoring stations along State Route 25 in southeastern Massachusetts. Theoretically, the specific conductance of a water sample is the sum of the individual conductances attributed to each ionic species in solution-the product of the concentrations of each ion in milliequivalents per liter (meq/L) multiplied by the equivalent ionic conductance at infinite dilution-thereby establishing the principle of superposition. Superposition provides an estimate of actual specific conductance that is within measurement error throughout the conductance range of many natural waters, with errors of less than ?5 percent below 1,000 microsiemens per centimeter (?S/cm) and ?10 percent between 1,000 and 4,000 ?S/cm if all major ionic constituents are accounted for. A semi-empirical method (adjusted superposition) was used to adjust for concentration effects-superposition-method prediction errors at high and low concentrations-and to relate measured specific conductance to that calculated using superposition. The adjusted superposition method, which was developed to interpret the State Route 25 highway-runoff records, accounts for

  6. Effects of highway deicing chemicals on shallow unconsolidated aquifers in Ohio, interim report, 1988-93

    Science.gov (United States)

    Jones, A.L.; Sroka, B.N.

    1997-01-01

    County sites) are potentially affected by direct application of deic ing chemicals. Climatic data from the period January 1991 through September 1993 show that cold weather, and therefore deicing chemical application rates, varied widely across the State. As a consequence, only minor traces of dissolved chloride above background concentrations (mean, 12-25 mg/L) were determined in ground-water samples from the Pickaway County, Clark County, and Champaign County sites. At the Ashland and Richland County sites, dissolved chlo ride concentrations increased above background concentrations (from the upgradient well, pre sumably unaffected by road salt) only intermittently (mean background concentrations of 3-25 mg/L, rising to a mean of 49-77 mg/L). For the interim reporting period, the mean dissolved chloride concentration for all downgradient wells was about 2 times the background concentra tion (25mg/L) at the Ashland County site (50 mg/L) and 14 times the background concentration (3 mg/L) at the Richland County site (40 mg/L). At the Lucas County, Portage County, and Ash tabula County sites, deicing-chemical application was consistent throughout the winter, and downgradient dissolved chloride concentrations rarely returned to background concentrations (mean 6-32 mg/L) throughout the period. For the interim reporting period, the mean dissolved chloride concentration for all downgradient wells was about 3 times the background concentra tion at the Lucas County site (92 mg/L), 72 times the background concentration at the Portage County site (432 mg/L, 2 downgradient wells), and 21 times the background concentration at the Ashtabula County site (279 mg/L). Other factors that may affect the movement of deicing chemicals through the aquifer were examined, such as precipitation amounts; the types of subsurface materials; ground-water velocity and gradient; hydraulic conductivity; soil type; land use; and ODOT deicing priority. A final report is planned for 2001 afte

  7. Salt and the Rough-skinned Newt (Taricha granulosa): Evolutionary Investigations of Local Adaptation to an Anthropogenic and Natural Stressor

    OpenAIRE

    Hopkins, Gareth Rowland

    2015-01-01

    Amphibians are osmotically-challenged due to their highly permeable skin and egg membranes. As such, biologists have mostly ignored their occurrence in saline habitats. The goal of this dissertation was to investigate the ability of amphibians to adapt to inhabit these osmotically-stressful environments. As freshwater resources are increasingly salinized due to a combination of anthropogenic and natural stressors, including road-deicing salt application, coastal storm events, and sea-level ri...

  8. 融雪剂对五种北方主要农作物种子萌发过程的干扰作用%Interference of Deicing Salt on Germination of Some Main Crops Seeds in North China

    Institute of Scientific and Technical Information of China (English)

    李雪; 赵淑华; 蒋媛媛; 王明霞

    2012-01-01

    目的 观察氯盐类融雪剂对五种北方主要农作物种子萌发过程的干扰作用.方法 玉米、大豆、水稻、黄瓜、白菜种子的半数发芽抑制浓度(LD50)分别为19.1、10.6、16.2、20.2、12.0 mg/ml.每种农作物的种子分别在对照(蒸馏水)组和低( 1/8 LD50)、中(1/4LD50)、高剂量(1/2 LD50)融雪剂溶液中培养,玉米、大豆、水稻、黄瓜每组20粒,白菜每组40粒,相同浓度实验重复5次.当对照组种子发芽率达到90%时,测定脯氨酸、可溶性蛋白质、总游离氨基酸的含量.结果 黄瓜种子在高剂量组脯氨酸含量明显下降(P<0.05);白菜种子在各剂量组均明显下降(P<0.05);大豆种子在高剂量组明显升高(P<0.05);水稻种子在中剂量组下降,而在高剂量组升高(P<0.05);玉米种子在中、低剂量组升高(P<0.05),而在高剂量组下降(P<0.05).黄瓜种子在中、高剂量组可溶性蛋白含量明显下降(P<0.05);白菜和水稻种子在高剂量组明显增高(P<0.05);大豆种子在中、低剂量组明显下降,而在高剂量组明显增高(P<0.05);玉米种子在各剂量组均明显升高(P<0.05).水稻种子在中剂量组总游离氨基酸含量下降(P<0.05),在高剂量组升高(P<0.05);黄瓜和大豆种子在各剂量组均下降(P<0.05);白菜和玉米种子在中、低剂量组下降(P<0.05),在高剂量组升高(P<0.05).结论 在本实验条件下,氯盐类融雪剂对农作物种子的发育过程有干扰作用,并且大豆、水稻和玉米的抗干扰能力相对较强.%Objective To study the interference of deicing salt in the germination process of some of the main corps in north China. Methods In the previous experiments, for corn, soybeans, rice, cucumber, Chinese cabbage seeds, LDM were 19.1,10.6,16.2,20.2 and 12.0 mg/ml respectively. Each of the seeds of crops were in control group (distilled water) and low (1/8 LD50), moderate (1/4 LD50), high dose (1/2 LD50

  9. Numerical analysis on thermal characteristics and ice melting efficiency for microwave deicing vehicle

    Science.gov (United States)

    Wang, Can; Yang, Bo; Tan, Gangfeng; Guo, Xuexun; Zhou, Li; Xiong, Shengguang

    2016-05-01

    In the high latitudes, the icy patches on the road are frequently generated and have a wide distribution, which are difficult to remove and obviously affect the normal usage of the highways, bridges and airport runways. Physical deicing, such as microwave (MW) deicing, help the ice melt completely through heating mode and then the ice layer can be swept away. Though it is no pollution and no damage to the ground, the low efficiency hinders the development of MW deicing vehicle equipped without sufficient speed. In this work, the standard evaluation of deicing is put forward firstly. The intensive MW deicing is simplified to ice melting process characterized by one-dimensional slab with uniform volumetric energy generation, which results in phase transformation and interface motion between ice and water. The heating process is split into the superposition of three parts — non-heterogeneous heating for ground without phase change, heat transfer with phase change and the heat convection between top surface of ice layer and flow air. Based on the transient heat conduction theory, a mathematical model, combining electromagnetic and two-phase thermal conduction, is proposed in this work, which is able to reveal the relationship between the deicing efficiency and ambient conditions, as well as energy generation and material parameters. Using finite difference time-domain, this comprehensive model is developed to solve the moving boundary heat transfer problem in a one-dimensional structured gird. As a result, the stimulation shows the longitudinal temperature distributions in all circumstances and quantitative validation is obtained by comparing simulated temperature distributions under different conditions. In view of the best economy and fast deicing, these analytic solutions referring to the complex influence factors of deicing efficiency demonstrate the optimal matching for the new deicing design.

  10. Cultural Meromixis: the Influence of Road Salt Deicers on Two Urban Kettle Lakes

    Science.gov (United States)

    Koretsky, C.; Sibert, R.; Wyman, D. A.; Griffey, D.; Krishnamurthy, R. V.

    2014-12-01

    The increasing global use of road salt deicers has led to an influx of salts, particularly NaCl and CaCl2, into urban surface waters. This influx has led to documented salinization of drinking water supplies, as well as damage to ecosystems. There is an increasing recognition that the influx of road salt deciers may also influence the physical mixing of lakes, with dramatic consequences for lake biogeochemistry. In this study, the water column chemistry of two kettle lakes in urban Kalamazoo, MI, USA was monitored for over a year. Woods Lake, an ~9.7 ha, 14 m max depth lake, receives most water from storm water sewers, whereas nearby Asylum Lake, an ~19.8 ha, 15.8 m max depth lake, is primarily groundwater fed. The water columns of both lakes are strongly redox stratified, but exhibit some significant differences in water chemistry. The input of road salt has caused Woods Lake to transition to meromixis, with permanently anoxic bottom waters and significant accumulations of dissolved Mn(II), Fe(II), NH3, PO4-3 and sometimes HS- in the hypolimnion. In contrast, Asylum Lake appears to be monomictic, with turnover occurring in fall, but not spring. During most seasons, the hypolimnion of Asylum Lake has significant levels of dissolved Mn(II), NH3, PO4-3, and sometimes HS-, but dissolved Fe(II) remains below detection limits. A comparison of δ18O and δD with the local meteoric water line demonstrates that both lakes undergo significant evaporation. Woods Lake is considerably more influenced by evaporation than Asylum Lake, presumably due to the longer residence time of water in Woods Lake. The longer residence time, together with the smaller volume of water in Woods Lake, likely explains the more rapid transition to meromixis compared to Asylum Lake. This study demonstrates that road salt deicers can significantly influence the biogeochemistry and physical function of urban lakes, and in some cases can result in dimictic lakes transitioning to cultural meromixis.

  11. Fate and Transport of Road Salt During Snowmelt Through a Calcareous Fen: Kampoosa Bog, Stockbridge, Massachusetts

    Science.gov (United States)

    Rhodes, A. L.; Guswa, A. J.; Pufall, A.

    2007-12-01

    Kampoosa Bog is the largest and most ecologically diverse calcareous lake-basin fen in Massachusetts. Situated within a 4.7 km2 drainage basin, the open fen (approx. 20 acres) consists of a floating mat of sedges (incl. Carex aquatilis and Cladium mariscoides) that overlie peat and lake clay deposits. Mineral weathering of marble bedrock within the drainage basin supplies highly alkaline ground and surface waters to the fen basin. The natural chemistry has been greatly altered by road salt runoff from the Massaschusetts Turnpike, and in question is whether disturbance from the Turnpike and a gas pipline has facilitated aggressive growth by the invasive species Phragmites australis. Considered to be one of the most significant rare species habitats in the state, Massachusetts has designated Kampoosa Bog an Area of Critical Environmental Concern, and a committee representing several local, regional, and state agencies, organizations, and citizens manages the wetland. The purpose of this study is to characterize the hydrologic and chemical response of the wetland during snowmelt events to understand the fate and movement of road salt (NaCl). Concentrations of Na and Cl in the fen groundwater are greatest close to the Turnpike. Concentrations decrease with distance downstream but are still greatly elevated relative to sites upstream of the Turnpike. During snowmelt events, the fen's outlet shows a sharp rise in Na and Cl concentrations at the onset of melting that is soon diluted by the added meltwater. The Na and Cl flux, however, is greatest at peak discharge, suggesting that high-flow events are significant periods of export of dissolved salts from the fen. Pure dissolution of rock salt produces an equal molar ratio between Na and Cl, and sodium and chloride imbalances in stream and ground waters suggest that ~20% of the Na is stored on cation exchange sites within the peat. The largest imbalances between Na and Cl occur deeper within the peat, where the peat is

  12. CLEAN-ROADS project: air quality considerations after the application of a novel MDSS on winter road maintenance activities

    Science.gov (United States)

    Pretto, Ilaria; Malloci, Elisa; Tonidandel, Gabriele; Benedetti, Guido; Di Napoli, Claudia; Piazza, Andrea; Apolloni, Roberto; Cavaliere, Roberto

    2016-04-01

    With this poster we present the environmental benefit on air quality derived by the application of the CLEAN-ROADS pilot project. The CLEAN-ROADS project addresses the problem of the environmental pollution caused by de-icing salts during winter road maintenance activities in the Province of Trento (Italy). A demonstrative Maintenance Decision Support System (MDSS) has been developed in order to improve the intervention procedures of the road management service. Specifically it aims to optimize the efficiency of how available resources (e.g., salt consumption) are currently used while guaranteeing the current level of road safety. The CLEAN-ROADS project has been tested and validated on a test area located in a valley bottom (Adige Valley), where the highest optimization margins are to be expected. The project supports current road maintenance practices, which has proved to be reliable and accurate, with a new scalable and energy-efficient road monitoring system. This system is based on a network of road weather stations (road weather information system, RWIS) installed on the test route. It is capable to collect real-time data about the road conditions and to perform short-term and now-cast road weather forecasts, which actively integrate weather data and bulletins covering the target area [1]. This poster presents the results obtained from a three-year monitoring activity with the aim to (1) determine the impact of de-icing salts on air quality and (2) quantify the improvements obtained by the application of the CLEAN-ROADS project on air quality. The Ambient Air Quality and Cleaner Air for Europe Directive (2008/50/EC) states that contributions to exceedances of particulate matter PM10 limit values that are attributable to road winter salting may be subtracted when assessing compliance with air quality limit values, once provided that reasonable measures have been taken to lower concentrations [2]. As the de-icing salts used in road maintenance are mainly based

  13. 14 CFR 25.929 - Propeller deicing.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller deicing. 25.929 Section 25.929... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.929 Propeller deicing. (a) For airplanes... combustible fluid is used for propeller deicing, §§ 25.1181 through 25.1185 and 25.1189 apply....

  14. Best management practices for airport deicing stormwater.

    Science.gov (United States)

    Switzenbaum, M S; Veltman, S; Mericas, D; Wagoner, B; Schoenberg, T

    2001-06-01

    With the advent of new regulations concerning aircraft deicing and management of spent aircraft deicing fluids (ADFs), many airports now face the dual challenges of simultaneously maintaining public safety and protecting the environment. This paper provides a theoretical assessment of the potential environmental impact of stormwater runoff and offers detailed current information on alternative deicing fluid application methods and materials, collection and treatment practices.

  15. Hydrogeologic Processes Impacting Storage, Fate, and Transport of Chloride from Road Salt in Urban Riparian Aquifers.

    Science.gov (United States)

    Ledford, Sarah H; Lautz, Laura K; Stella, John C

    2016-05-17

    Detrimental effects of road salt runoff on urban streams are compounded by its facilitated routing via storm drains, ditches, and flood channels. Elevated in-stream salinity may also result from seasonal storage and discharge of chloride in groundwater, and previous work has hypothesized that groundwater discharge to streams may have the effect of diluting stream chloride concentrations in winter and enriching them in summer. However, the hydrogeological processes controlling these patterns have not been thoroughly investigated. Our research focuses on an urban stream and floodplain system in Syracuse, NY, to understand how groundwater and surface water exchange impacts chloride storage, fate, and transport. We created a 3D groundwater flow and solute transport model of the floodplain, calibrated to the distributions of floodplain hydraulic heads and groundwater fluxes to the stream throughout the reach. We used a sensitivity analysis to calibrate and evaluate the influence of model parameters, and compared model outputs to field observations. The main source mechanism of chloride to the floodplain aquifer was high-concentration, overbank flood events in winter that directly recharged groundwater. The modeled residence time and storage capacity of the aquifer indicate that restoration projects designed to promote floodplain reconnection and the frequency of overbank flooding in winter have the potential to temporarily store chloride in groundwater, buffer surface water concentrations, and reduce stream concentrations following periods of road salting.

  16. The Impact of Road Maintenance Substances on Metals Surface Corrosion

    Directory of Open Access Journals (Sweden)

    Jolita Petkuvienė

    2011-04-01

    Full Text Available The purpose of research is to assess changes in the visual metal surface due to the exposure of road maintenance salts and molasses (‘Safecote’. Chlorides of deicing salts (NaCl, CaCl2 are the main agents affecting soil and water resources as well as causing the corrosion of roadside metallic elements. Molasses (‘Safecote’ is offered as an alternative to deice road pavement by minimizing the corrosion of metal elements near the road. A laboratory experiment was carried out to immerse and spray metals with NaCl, CaCl2, NaCl:CaCl2 and NaCl:Safecote solutions. The obtained results showed that NaCl:Safecote solution had the lowest coating with corrosion products (the average 17±4 % of the surface. The solutions of NaCl, CaCl2 and NaCl:CaCl2 had the highest percentage rate of the corrosion product on the metal surface reaching an average of 33±5 %. Article in English

  17. Numerical simulation and experimental validation of aircraft ground deicing model

    OpenAIRE

    2016-01-01

    Aircraft ground deicing plays an important role of guaranteeing the aircraft safety. In practice, most airports generally use as many deicing fluids as possible to remove the ice, which causes the waste of the deicing fluids and the pollution of the environment. Therefore, the model of aircraft ground deicing should be built to establish the foundation for the subsequent research, such as the optimization of the deicing fluid consumption. In this article, the heat balance of the deicing proce...

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

    Science.gov (United States)

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

  19. Salt overload: How quickly does road salt move from road to groundwater to stream in Baltimore County, MD and what are the effects on soil, groundwater, and stream chemistry?

    Science.gov (United States)

    Moore, J.; Sandosky, B.; McGuire, M.; Casey, R.; Snodgrass, J.; Lev, S. M.

    2013-12-01

    The portion of the landscape covered by roads and other impervious surfaces has increased over the last 50 years. Concurrently, application of road salt, primarily sodium chloride (NaCl), as a de-icer has increased in areas of North America with regular ice and snowfall events. Over the last 10 - 15 years, numerous investigators reported that decades of road salt application has resulted in growing concentrations of sodium and chloride in groundwater and surface water. These road salt-derived elements are present at elevated levels in the surface and groundwaters of impacted watersheds year round. An understudied aspect of road salt impacts has been the role that stormwater management basins (SMBs) play in altering the timing and location of road salt loading to urban and suburban groundwater-surface water systems. SMBs have become common in construction and development over the last 15-20 years. One of the major goals of SMBs is to decrease direct runoff from impervious surfaces to streams by redirecting that runoff into shallow groundwater and thus reducing the flashiness of streams in urban and suburban areas. An unintended consequence of SMBs is that road salt runoff from impervious surfaces is focused into the SMBs and loaded into the vadose zone and shallow groundwater in the winter and then exported to surface water throughout the year. As part of an onging project in a suburb northwest of Baltimore, MD, water samples were collected several times a year from groundwater below two SMBs, a shallow groundwater aquifer downgradient of the SMBs, and a second-order stream for which the aquifer provides baseflow. The major elemental chemistry of the samples was measured. Conductivity and water level loggers were installed to collect data in wells and surface water between grab sampling events. The logger records will be analyzed using spatio-temporal data mining techniques to extract important patterns in the data and to highlight and understand seasonal trends and

  20. THE AIRPORT DE-ICING OF AIRCRAFTS

    Directory of Open Access Journals (Sweden)

    Robert KONIECZKA

    2015-03-01

    Full Text Available This article provides a summary of the issues involved in de-icing several kinds of aircrafts before flight. The basic risks of an iced aircraft and the factors that can influence its intensity are stated. It discusses the methods for de-icing and protecting against ice formation on small aircrafts, helicopters, and large aircrafts. It also classifies the fluids and other methods used for these de-icing operations, and explains the characteristics and limitations of their use.

  1. Military Specification Updates & Deicing Working Group Initiatives

    Science.gov (United States)

    2011-08-18

    Air Force Petroleum Agency I n t e g r i t y - S e r v i c e - E x c e l l e n c e Military Specification Updates & Deicing Working Group...00-2011 4. TITLE AND SUBTITLE Military Specification Updates & Deicing Working Group Initiatives 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...Corrosion Runway Deicing Fluid Partnership with Battelle Memorial Institute (lead agency), AFRL/ ASC, Army (CRREL), Navy (NAVAIR), Octagon, AMIL

  2. Storage and release of road-salt contamination from a calcareous lake-basin fen, western Massachusetts, USA.

    Science.gov (United States)

    Rhodes, Amy L; Guswa, Andrew J

    2016-03-01

    Road salt (NaCl) applications to highways have increased stream sodium and chloride concentrations due to retention within watersheds. The mechanisms for retention and export of Na(+) and Cl(-) from different environments are not fully understood. This field study examines the hydrologic and cation exchange processes that store and release Na(+) and Cl(-) from a calcareous fen adjacent to a highway. Despite high concentrations of Ca(2+) and Mg(2+), elevated salt concentrations enable Na(+) to occupy up to 15% of the cation exchange capacity of shallow peat. Calculations of selectivity coefficients show that Na(+) preferentially exchanges with Mg(2+), and Na(+) can be desorbed under more dilute conditions caused by precipitation and snowmelt. Detailed sampling of surface and ground waters during three snowmelt events illustrate early releases of Na(+) and Cl(-) at the onset of melting, with maximum fluxes coinciding with peak discharge. From 7 March through 4 April 2005, the flux of dissolved salt exiting the wetland amounts to 13% (Na) and 17% (Cl) of annual rock salt applied to the highway. For all of 2005, the total salt mass leaving the wetland via Kampoosa Brook is similar to the amount of road salt applied; 50% of the annual salt efflux occurred during the snowmelt season of March through May. In general, exported Na(+) and Cl(-) correlate with the number of lane miles of highway crossing the watershed. Large rain events outside of winter months are more effective than snowmelt with reducing dissolved salts because snowmelt also introduces contamination. For this and other wetlands having alkaline geochemistry and high flushing rates, management strategies that reduce rock salt amounts to roadways will assist with reducing salt contamination to levels less toxic to vegetation and aquatic organisms. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Characterization of hydrophobic and hydrophilic coatings as deicing and anti-icing

    Science.gov (United States)

    Aoki, Akihito; Morita, Katsuaki; Konno, Akihisa; Sakaue, Hirotaka

    2010-11-01

    Anti-icing is necessary in various fields, such as aeronautics, roads, power lines, ships, and architectures. Deicing fluids, and sometimes hot water, work to prevent from icing. Due to environmental issue, deicing fluids are not always welcome to use. We study hydrophobic and hydrophilic coatings for anti-icing. By coating these to a target surface, it prevents icing without damaging the environment. We present a characterization method of hydrophobic and hydrophilic coatings for deicing and anti-icing. We provide a temperature-control room to create an icing condition, such as -10 to 0 degrees C. Under the controlled room, the contact angle measurement as well as the force measurement is employed. Total 15 coatings are characterized. Based on the tests of all coatings, we propose a combined coating from some characterized ones.

  4. 基于表面能理论的除冰盐侵蚀沥青-矿料界面机理研究%Study on erosion of new de-icing salt on asphalt mixture based on surface energy theory

    Institute of Scientific and Technical Information of China (English)

    肖庆一; 胡海学; 王丽娟; 李宁利

    2012-01-01

    During the winter maintenance work, the use of new de-icing salt makes erosion damage of asphalt pavement. The contact angles of de-icing salt solution on asphalt surface as well as mineral aggregate surface were determined by Sessile Drop and Capillary rise, respectively. This study calculates the composition of surface energy of asphalt, mineral aggregate and sodium acetate solution, and analyses, using the surface energy theory as well as Gibbs free energy relationship, the stability of asphalt mixture in different composition systems and the erosion tendency of de-icing salt solution on mineral aggregate-asphalt interface. The results show that the erosion of de-icing salt solution on limestone-asphalt interface is more obvious than water. Moreover, the erosion tendency increases with increasing solution concentration and the process has a strong spontaneity. The erosion damage depends on the amphiphilic structure of acetate ion and defects of asphalt-aggregate interface.%冬季沥青路面除冰雪养护工作中,醋酸类新型除冰盐的使用已对沥青路面造成侵蚀破坏,本文依据表面能理论研究分析新型除冰盐对沥青混合料的侵蚀破坏机理.研究首先利用Van Oss三相物质界面接触过程中的自由能变化理论,构建溶液侵蚀沥青-矿料界面动力学模型;基于Young-Dupré液体在固体表面接触角理论,利用滴落法和毛细管上升法求解出沥青、石灰石矿料的表面能参数;并利用逆向求解的方法得到不同浓度除冰盐溶液的表面能参数;计算得出除冰盐侵蚀破坏过程的三相系统(沥青、矿料和除冰盐溶液)的吉布斯自由能变化,从而基于表面能理论以及分子官能团组成角度进行了深入的机理解释.结果表明:醋酸类除冰盐溶液对沥青-矿料的界面侵蚀破坏的能力较蒸馏水强,且侵蚀趋势随溶液浓度增加而增加,反应过程自发性逐渐增强;侵蚀破坏主要与醋酸类除冰盐中

  5. The Protection and Treatment of Landscaping Plant Secondary Disasters (Deicing Salt Damage) Caused by Extreme Weather%极端气候造成园林绿化植物次生灾害(融雪剂危害)的防护与救治

    Institute of Scientific and Technical Information of China (English)

    曹臻; 周雪; 柏超

    2012-01-01

    the deicing salt is usually used to alleviate urban traffic pressure after snow in winter. However, it is severely harmful on landscaping plants. In order to reduce or avoid this kind of harm, a variety of protections and treatments are actively explored. This paper describes the protection of landscaping plants before it is harmed by deicing salt, as well as its treatment after it is harmed. Moreover, this paper discusses how to respond to extreme weather and city-specific environmental impact on landscaping plants for Beijing landscaping industry in a high efficient and low cost way, and find the balance point to ensure normal operation of social life and maintenance of healthy development of ecology.%每年冬季降雪之后,为缓解城市交通压力,相关部门均会撒施融雪剂.而融雪剂的使用对园林绿化植物造成了极大危害.为了减少或避免这种危害,我们积极探索各种防护、救治措施.通过对园林绿化植物受融雪剂危害之前的防护和受融雪剂危害之后的救治,来探讨北京园林绿化行业如何高效、低耗地应对极端天气和城市特定环境对园林绿化植物的影响,进而找到保证社会生活正常运转与维持生态环境健康发展的平衡点.

  6. Agent-based scheduling for aircraft deicing

    NARCIS (Netherlands)

    Mao, X.; Ter Mors, A.W.; Roos, N.; Witteveen, C.

    2006-01-01

    The planning and scheduling of the deicing and anti-icing activities is an important and challenging part of airport departure planning. Deicing planning has to be done in a highly dynamic environment involving several autonomous and self-interested parties. Traditional centralized scheduling approa

  7. Roads

    Data.gov (United States)

    National Park Service, Department of the Interior — This dataset shows the roads within and near Delaware Water Gap NRA taken from 1:4800 scale mapping that was done for the original land acquisition period (1967)...

  8. Mobilization of major and trace constituents of highway runoff in groundwater potentially caused by deicing chemical migration

    Science.gov (United States)

    Granato, Gregory E.; Church, Peter E.; Stone, Victoria J.

    1995-01-01

    The quality of water in unsaturated zones and groundwater is affected by the major ions in deicing chemicals applied to roads and highways. The assessment of the environmental effects of highway runoff requires investigations to determine whether other major and trace constituents are mobilized during deicing chemical migration through the unsaturated zone and groundwater. In this regard, groundwater samples were analyzed in February and August 1991, and March, August, and November 1993 at a test site along Route 25 in southeastern Massachusetts. Analyses indicated that concentrations of major and trace chemical constituents of highway runoff in groundwater are substantially higher downgradient than upgradient from the highway.

  9. Numerical simulation and experimental validation of aircraft ground deicing model

    Directory of Open Access Journals (Sweden)

    Bin Chen

    2016-05-01

    Full Text Available Aircraft ground deicing plays an important role of guaranteeing the aircraft safety. In practice, most airports generally use as many deicing fluids as possible to remove the ice, which causes the waste of the deicing fluids and the pollution of the environment. Therefore, the model of aircraft ground deicing should be built to establish the foundation for the subsequent research, such as the optimization of the deicing fluid consumption. In this article, the heat balance of the deicing process is depicted, and the dynamic model of the deicing process is provided based on the analysis of the deicing mechanism. In the dynamic model, the surface temperature of the deicing fluids and the ice thickness are regarded as the state parameters, while the fluid flow rate, the initial temperature, and the injection time of the deicing fluids are treated as control parameters. Ignoring the heat exchange between the deicing fluids and the environment, the simplified model is obtained. The rationality of the simplified model is verified by the numerical simulation and the impacts of the flow rate, the initial temperature and the injection time on the deicing process are investigated. To verify the model, the semi-physical experiment system is established, consisting of the low-constant temperature test chamber, the ice simulation system, the deicing fluid heating and spraying system, the simulated wing, the test sensors, and the computer measure and control system. The actual test data verify the validity of the dynamic model and the accuracy of the simulation analysis.

  10. 氯盐类融雪剂对混凝土路面危害分析%The analysis of chloride deicing salts’ hazard on concrete pavement

    Institute of Scientific and Technical Information of China (English)

    王有振

    2014-01-01

    氯盐类融雪剂在我国北方地区有着广泛的使用,但在使用过程中,存在对融雪剂的腐蚀性认识不足,缺乏相应产品标准和使用规范等问题。本文对融雪剂的类型进行了介绍,对氯盐类融雪剂对混凝土路面的腐蚀机理进行分析。通过冻融循环实验,研究了几种常见氯盐类融雪剂的腐蚀特性,并得出实验结论。%Chloride deicing salts has been widely used in northern China ,but the corrosion of deicing salt usually has been neglected during the use,and there is a lack of the appropriate product standards and the use of norms.In this paper,types of deicing salt are introduced;deicing salts of chlorine on the corrosion mechanism of concrete pavement are analyzed .By freeze-thaw cycle experiments ,the corrosion properties of several common chloride deicing salts has been studied ,and the conclusions of the experiment has been drawn .

  11. Influential Factors on Deicing Performance of Electrically Conductive Concrete Pavement

    Institute of Scientific and Technical Information of China (English)

    TANG Zuquan; QIAN Jueshi; LI Zhuoqiu; WU Chuanming

    2006-01-01

    The deicing experiment of carbon fiber reinforced electrically conductive concrete (CFRC) slab was conducted in laboratory at first, then the deicing process of CFRC pavement was analyzed by means of finite element method (FEM). At last, based on the energy conservation law and the computing results of finite element method, the influential factors including the setting of electric heating layer, environmental temperature, the thickness of ice, material parameters, and deicing power on deicing performance and energy consumption were discussed.

  12. Salt vulnerability assessment methodology for municipal supply wells

    Science.gov (United States)

    Betts, Andrew; Gharabaghi, Bahram; McBean, Ed; Levison, Jana; Parker, Beth

    2015-12-01

    De-icing agents containing chloride ions used for winter road maintenance have the potential to negatively impact groundwater resources for drinking water supplies. A novel methodology using commonly-available geospatial data (land use, well head protection areas) and public accessible data (salt application rates, hydrometric data) to identify salt vulnerable areas (SVAs) for groundwater wells is developed to prioritize implementation of better management practices for road salt applications. The approach uses simple mass-balance terms to collect chloride input from 3 pathways: surface runoff, shallow interflow and baseflow. A risk score is calculated, which depends on the land use within the respective municipal supply well protection area. Therefore, it is plausible to avoid costly and extensive numerical modeling (which also would bear many assumptions, simplifications and uncertainties). The method is applied to perform a vulnerability assessment on twenty municipal water supply wells in the Grand River watershed, Ontario, Canada. The calculated steady-state groundwater recharge chloride concentration for the supply wells is strongly correlated to the measured transient groundwater chloride concentrations in the case study evaluation, with an R2 = 0.84. The new method provides a simple, robust, and practical method for municipalities to assess the long-term risk of chloride contamination of municipal supply wells due to road salt application.

  13. 14 CFR 23.1095 - Carburetor deicing fluid flow rate.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Carburetor deicing fluid flow rate. 23.1095 Section 23.1095 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Induction System § 23.1095 Carburetor deicing fluid flow rate. (a) If a carburetor deicing fluid system...

  14. 14 CFR 121.225 - Propeller deicing fluid.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Propeller deicing fluid. 121.225 Section 121.225 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Propeller deicing fluid. If combustible fluid is used for propeller deicing, the certificate holder...

  15. 14 CFR 125.123 - Propeller deicing fluid.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Propeller deicing fluid. 125.123 Section 125.123 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Requirements § 125.123 Propeller deicing fluid. If combustible fluid is used for propeller deicing,...

  16. Effect of salt and urban water samples on bacterivory by the ciliate, Tetrahymena thermophila

    Energy Technology Data Exchange (ETDEWEB)

    St Denis, C.H.; Pinheiro, M.D.O.; Power, M.E. [Department of Biology, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1 (Canada); Bols, Niels C., E-mail: ncbols@uwaterloo.c [Department of Biology, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1 (Canada)

    2010-02-15

    The effect of road salt on the eating of bacteria or bacterivory by the ciliate, Tetrahymena thermophila, was followed in non-nutrient Osterhout's solution with Escherichia coli expressing green fluorescent protein. Bacterivory was impaired at between 0.025 and 0.050% w/v but the ciliates appeared to have normal morphologies and motilities, whereas at above 0.1%, bacterivory was blocked and many ciliates died. By contrast, E. coli remained viable, suggesting salt could alter predator-prey relationships in microbial communities. In nutrient medium, salt was not toxic and the ciliates grew. After growth in salt, ciliates consumed bacteria in 0.2% salt, indicating the salt acclimation of bacterivory. Bacteria and ciliates were added to urban creek samples to compare their capacity to support exogenous bacterivory. Even though samples were collected weekly for a year and be expected to have fluctuating salt levels as a result of deicing, all creek samples supported a similar level of bacterivory. - Road salt at some concentrations inhibits bacterivory by ciliates, and thus potentially could alter the microbial food web.

  17. Deicing and Anti-Icing Unite

    Science.gov (United States)

    2002-01-01

    With funding from Glenn's Small Business Innovation Research (SBIR) program, Cox & Company, Inc., built an ice protection system that combines thermal anti-icing and mechanical deicing to keep airfoils (wings and other lifting surfaces) clear of ice. Cox's concept was to combine an anti-icing system with NASA's Electro-Mechanical Expulsion Deicing System, a mechanical deicer. The anti-icing element of this hybrid would reduce the aerodynamic losses associated with deicing systems. The Cox Low Power Ice Protection System is the first new aircraft ice protection system that has been approved by the Federal Aviation Administration for use on a business jet in 40 years. While the system is currently sized for Premier class aircraft, there are no apparent constraints prohibiting its use on aircraft of any size. The company is investigating further applications, such as adapting the system for unmanned aerial vehicles and other military aircraft.

  18. Soluble salt removal from MSWI fly ash and its stabilization for safer disposal and recovery as road basement material.

    Science.gov (United States)

    Colangelo, F; Cioffi, R; Montagnaro, F; Santoro, L

    2012-06-01

    Fly ash from municipal solid waste incinerators (MSWI) is classified as hazardous in the European Waste Catalogue. Proper stabilization processes should be required before any management option is put into practice. Due to the inorganic nature of MSWI fly ash, cementitious stabilization processes are worthy of consideration. However, the effectiveness of such processes can be severely compromised by the high content of soluble chlorides and sulphates. In this paper, a preliminary washing treatment has been optimized to remove as much as possible soluble salts by employing as little as possible water. Two different operating conditions (single-step and two-step) have been developed to this scope. Furthermore, it has been demonstrated that stabilized systems containing 20% of binder are suitable for safer disposal as well as for material recovery in the field of road basement (cement bound granular material layer). Three commercially available cements (pozzolanic, limestone and slag) have been employed as binders.

  19. Deicing System Protects General Aviation Aircraft

    Science.gov (United States)

    2007-01-01

    Kelly Aerospace Thermal Systems LLC worked with researchers at Glenn Research Center on deicing technology with assistance from the Small Business Innovation Research (SBIR) program. Kelly Aerospace acquired Northcoast Technologies Ltd., a firm that had conducted work on a graphite foil heating element under a NASA SBIR contract and developed a lightweight, easy-to-install, reliable wing and tail deicing system. Kelly Aerospace engineers combined their experiences with those of the Northcoast engineers, leading to the certification and integration of a thermoelectric deicing system called Thermawing, a DC-powered air conditioner for single-engine aircraft called Thermacool, and high-output alternators to run them both. Thermawing, a reliable anti-icing and deicing system, allows pilots to safely fly through ice encounters and provides pilots of single-engine aircraft the heated wing technology usually reserved for larger, jet-powered craft. Thermacool, an innovative electric air conditioning system, uses a new compressor whose rotary pump design runs off an energy-efficient, brushless DC motor and allows pilots to use the air conditioner before the engine even starts

  20. Electromagnetic-Repulsion Systems For Deicing Aircraft

    Science.gov (United States)

    Smith, Samuel O.; Zieve, Peter

    1994-01-01

    Improved eddy-current electromagnetic-repulsion deicing systems developed for use on variety of exterior aircraft surfaces like leading edges of wings, engine inlets, propellers, and helicopter rotors. Fit to exterior surfaces, as retrofits or original equipment. Systems light in weight, consume little average power, and capable of protecting against severe icing conditions.

  1. Comparison of the Asphalt Pavement Deicing Technology%沥青路面除冰技术之比较

    Institute of Scientific and Technical Information of China (English)

    陈章

    2013-01-01

      道路结冰致使车轮与路面摩擦作用大大减弱,导致车辆打滑或刹车失灵,引起交通事故,阻塞交通运行,造成行人滑倒、摔伤等。本文通过对各种除冰技术的比较,给大家在选择除冰方法上提供借鉴。%Icy roads wil greatly decrease the friction force be-tween wheels of vehicles and roads, causing vehicle skid, brak-e failure, traffic jam or even traffic accidents. And pedestrians may slip down and get hurt. By comparing several techniques and methods of anti-icing and deicing, this thesis wants to give some suggestions for choosing the proper methods of anti-icin-g and deicing.

  2. Deicing/Propylene Glycol (PG) Microbial Remediation Technology

    Science.gov (United States)

    2011-05-01

    Deicing /Propylene Glycol (PG) Microbial Remediation Technology Environment, Energy Security, & Sustainability (E2S2) Symposium & Exhibition Ernest N...DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Deicing /Propylene Glycol (PG) Microbial Remediation Technology 5a. CONTRACT...Issues C. PG Remediation Project D. Summary E. Questions 2 3 Background • Aircraft deicing fluids (ADF) work planes fly in the winter o Military

  3. Acute lung injury following refrigeration coil deicing.

    Science.gov (United States)

    McKeown, Nathanael J; Burton, Brent T

    2012-03-01

    We report a case of a worker who developed ALI requiring mechanical ventilatory support after attempting to melt ice condensate by applying the flame of an oxy-acetylene torch to refrigeration coils charged with a halocarbon refrigerant in a closed environment. A discussion of possible etiologies are discussed, including phosgene, carbonyl fluoride, and nitrogen oxides. Primary prevention with adequate respiratory protection is recommended whenever deicing is performed in a closed space environment.

  4. Autonomous Deicing System For Airplane Wing

    Science.gov (United States)

    Hickman, G. A.; Gerardi, J. J.

    1993-01-01

    Prototype autonomous deicing system for airplane includes network of electronic and electromechanical modules at various locations in wings and connected to central data-processing unit. Small, integrated solid-state device, using long coils installed under leading edge, exciting small vibrations to detect ice and larger vibrations to knock ice off. In extension of concept, outputs of vibration sensors and other sensors used to detect rivet-line fractures, fatigue cracks, and other potentially dangerous defects.

  5. 14 CFR 23.1097 - Carburetor deicing fluid system capacity.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Carburetor deicing fluid system capacity... Powerplant Induction System § 23.1097 Carburetor deicing fluid system capacity. (a) The capacity of each... operation. (b) If the available preheat exceeds 50 °F. but is less than 100 °F., the capacity of the...

  6. Laser atomic emission analysis of airborne pollution of green stands by deicing agents

    Science.gov (United States)

    Bel'Kov, M. V.; Burakov, V. S.; Kiris, V. V.; Maksimova, I. A.; Raikov, S. N.; Sudnik, A. V.

    2010-05-01

    We present the results of analysis of airborne pollution of green stands along the Minsk Beltway by components of deicing agents (chlorine). We used laser spectral analysis for rapid determination of chlorine. Comparison of the analysis results for accumulation of salt components in samples collected from trees along the Minsk Beltway with control samples showed that the chlorine content is 3.7-5.5 times higher than the control values. The degree of pollution depends on the position of the trees on the forest edge relative to the highway, which is confirmed by reliable correlation coefficients.

  7. Determination of bile salt critical micellization concentration on the road to drug discovery.

    Science.gov (United States)

    Natalini, Benedetto; Sardella, Roccaldo; Gioiello, Antimo; Ianni, Federica; Di Michele, Alessandro; Marinozzi, Maura

    2014-01-01

    With the discovery of the bile acid (BA)-activated nuclear and membrane receptors, the role of BAs as signalling molecules in important paracrine and endocrine networks has been fully documented in the last decade. Besides regulating their own synthesis and transport, BAs have been demonstrated being involved in triggering the adaptive response to cholestasis and other insults to liver. More to the point, their recognized ability to control the general energy-related metabolism and inflammation processes has contributed to justify the renewed interest towards this class of amphiphilic steroidal compounds. All these evidences feed a continuing interest in the BA research aimed at designing and synthesizing new side chain- and body-modified derivatives endowed with improved biological and physico-chemical profiles, as well as with proper ADMET behaviour. In this context, the micellar aggregation of BAs, and the respective critical micellization concentration (CMC) value (determined on the BA sodium salt, BS), is considered a key parameter that needs to be determined in the preliminary phase of compound characterization, being implicated in cytotoxicity issues. An extraordinary variety of different analytical techniques and methods have been proposed along the years with the aim of better identifying the start of the self-aggregation process of BS monomers. The unicity of the physico-chemical nature of such class of compounds can be invoked to explain this unusual interest. Accordingly, a number of both invasive and non-invasive approaches have been developed along with a limited number of indirect chromatographic-based estimation strategies. Worth to be mentioned among the non-invasive determination methods are those based on potentiometry, freezing point depression, surface tension, nuclear magnetic resonance, viscosimetry, turbidimetry, microcalorimetry, refractometry, conductimetry, spectrophotometry, cholesterol solubilization, and monoglucuronide solubilization

  8. Effects of highway deicing chemicals on shallow unconsolidated aquifers in Ohio--final report

    Science.gov (United States)

    Kunze, Allison E.; Sroka, Bernard N.

    2004-01-01

    As a result of concerns about salt intrusion into drinking water aquifers, the effects of highway deicing chemicals on shallow aquifers were studied at eight locations in Ohio from 1988 through 2002. The study was done by the U.S. Geological Survey, in cooperation with the Ohio Department of Transportation and the Federal Highway Administration. Sites were selected along major undivided highways where drainage is by open ditches and ground-water flow is approximately perpendicular to the highway. Records of deicer application rates were kept, and apparent movement of deicing chemicals through shallow, unconsolidated aquifers was monitored by means of periodic measurements of specific conductance and concentrations of dissolved sodium, calcium, and chloride. The State routes monitored were the following: State Route (SR) 3 in Ashland County, SR 84 in Ashtabula County, SR 29 in Champaign County, SR 4 in Clark County, SR 2 in Lucas County, SR 104 in Pickaway County, SR 14 in Portage County, and SR 97 in Richland County. The study began in 1988 with background data collection, extensive literature review, and site selection. This process, including drilling of wells at numerous test sites and the eight selected sites, lasted 3 years. Routine groundwater sampling at 4- to 6-week intervals began in January 1991 and continued through September 1999. A multilevel, passive flow ground-water sampling device was constructed and used. Other conditions monitored on a regular basis included ground-water level (monitored continuously), specific conductance, air and soil temperature, precipitation,chloride concentration in soil samples, and deicing-chemical application times and rates. Evidence from water analysis, specific-conductance measurements, and surface-geophysical measurements indicates that three of the eight sites (Ashtabula County, Lucas County, and Portage County sites) were affected by direct application of deicing chemicals. Climatic data collected during the study

  9. The effects of calcium magnesium acetate (CMA) deicing material on the water quality of Bear Creek, Clackamas County, Oregon, 1999

    Science.gov (United States)

    Tanner, Dwight Q.; Wood, Tamara M.

    2000-01-01

    This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the Oregon Department of Transportation (ODOT), to evaluate the effects of the highway deicing material, calcium magnesium acetate (CMA), on the water quality of Bear Creek, in the Cascade Range of Oregon. ODOT began using CMA (an alternative deicer that has fewer adverse environmental effects than road salt) in the mid-1990s and began this study with the USGS to ensure that there were no unexpected effects on the water quality of Bear Creek. Streamflow, precipitation, dissolved oxygen, pH, specific conductance, and water temperature were measured continuously through the 1998?99 winter. There was no measurable effect of the application of CMA to Highway 26 on the biochemical oxygen demand (BOD), calcium concentration, or magnesium concentration of Bear Creek and its tributaries. BOD was small in all of the water samples, some of which were collected before CMA application, and some of which were collected after application. Five-day BOD values ranged from 0.1 milligrams per liter to 1.5 milligrams per liter, and 20-day BOD values ranged from 0.2 milligrams per liter to 2.0 milligrams per liter. Dissolved copper concentrations in a small tributary ditch on the north side of Highway 26 exceeded the U.S. Environmental Protection Agency aquatic life criteria on three occasions. These exceedances were probably not caused by the application of CMA because (1) one of the samples was a background sample (no recent CMA application), and (2) dissolved copper was not detected in Bear Creek water samples to which CMA was added during laboratory experiments.

  10. Contamination of environment in the road surroudings – impact of road salting on Norway spruce (Picea abies) and Scots pine (Pinus sylvestris)

    Science.gov (United States)

    Hegrová, Jitka; Steiner, Oliver; Goessler, Walter; Tanda, Stefan; Anděl, Petr

    2017-09-01

    A comprehensive overview of the influence of transport on the environment is presented in this study. The complex analysis of soil and needle samples provides an extensive set of data, which presents elemental contamination of the environment near roads. Traffic pollution (including winter road treatment) has a significant negative influence on our environment. Besides sodium and chlorine from winter maintenance many other elements are emitted into the environment. Three possible sources of contamination are assumed for environmental contamination evaluation: car emission, winter maintenance and abrasion from breaks and clutches. The chemical analysis focused on the description of samples from inorganic point of view. The influence of the contamination potential on the sodium and chlorine content in the samples of 1st year-old and 2nd year-old needles of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) is discussed. Additional soil samples were taken from each sampling site and analyzed to get insight in the sodium and chlorine distribution. Statistical evaluation was used for interpretation of complex interaction patterns between element concentrations in different aged needles based on localities character including distance from the road and element concentration in soils. This species of needles were chosen because of its heightened sensitivity towards salinization. The study was conducted in different parts of the Czech Republic. The resulting database is a source of valuable information about the influence of transport on the environment.

  11. Ice Detector and Deicing Fluid Effectiveness Monitoring System

    Science.gov (United States)

    Seegmiller, H. Lee B. (Inventor)

    1996-01-01

    An ice detector and deicing fluid effectiveness monitoring system for an aircraft is disclosed. The ice detection portion is particularly suited for use in flight to notify the flight crew of an accumulation of ice on an aircraft lifting and control surfaces, or helicopter rotors, whereas the deicing fluid effectiveness monitoring portion is particularly suited for use on the ground to notify the flight crew of the possible loss of the effectiveness of the deicing fluid. The ice detection portion comprises a temperature sensor and a parallel arrangement of electrodes whose coefficient of coupling is indicative of the formation of the ice, as well as the thickness of the formed ice. The fluid effectiveness monitoring portion comprises a temperature sensor and an ionic-conduction cell array that measures the conductivity of the deicing fluid which is indicative of its concentration and, thus, its freezing point. By measuring the temperature and having knowledge of the freezing point of the deicing fluid, the fluid effectiveness monitoring portion predicts when the deicing fluid may lose its effectiveness because its freezing point may correspond to the temperature of the ambient.

  12. The influence of temperature and salt on metal and sediment removal in stormwater biofilters.

    Science.gov (United States)

    Søberg, Laila C; Viklander, Maria; Blecken, Godecke-Tobias

    2014-01-01

    Stormwater biofilters are used to treat stormwater runoff. In countries with cold winter climates, biofilters are subject to low temperatures which, in some cases, are combined with potentially high salt concentrations from road de-icing, potentially affecting the biofilter's performance. Since stormwater biofilters have been developed without consideration of their critical winter use, a laboratory study was carried out to evaluate the performance of stormwater biofilters subjected to low and high temperatures, with and without salt. Both factors and their interaction had a significant effect on outflow concentrations and removal percentages. Salt had a negative impact on outflow concentrations, causing lower removal percentages for (especially dissolved) metals, this impact being most pronounced for Cu and Pb. The unrealistic combination of salt with high temperature seemed to further amplify the negative impacts of salt despite the fact that temperature alone did not cause significant differences in outflow concentrations and removal percentages. Still, biofilters showed the ability to treat stormwater efficiently under the simulated winter conditions; outflow concentrations for total metals as a minimum met the class 4 threshold value defined in the Swedish freshwater quality guidelines, while inflow concentrations clearly exceeded the threshold value for class 5. The relatively coarse filter material (which is recommended to facilitate infiltration during winter) did not seem to exacerbate biofilter performance.

  13. Single Neuron PID Control of Aircraft Deicing Fluids Rapid Heating System

    OpenAIRE

    2013-01-01

    Aircraft deicing fluids rapid heating system is widely used in aircraft ground deicing to ensure that the operation of flights can be safe and efficient. Aiming at the temperature turbulence problem of aircraft deicing system, this paper presents the single neuron PID control strategy which combine the advantage of conventional PID control with artificial neuron control. The aircraft deicing fluids rapid heating system and the scheme and working principle of the system is introduced. Simulati...

  14. 除冰车铲冰装置传送带的分析与研究%Analysis and Research of Deicing Special Vehicle Shovel Ice Device Conveyor

    Institute of Scientific and Technical Information of China (English)

    张志富; 黄其柏; 陈定方; 王晓娟

    2015-01-01

    In view of the phenomenon that icy roads to road traffic accidents have severely affected,a mechanical deicing special vehicle for road deicing,which carried on the reasonable design and layout is devised.The belt drive system of mechanical deicing device is major researched,infinitesimal dynamics equation of conveyor belt is established,and the belt drive system is analyzed in theory.Through theory design and engineering design algorithm,the belt transmission torque and power is analyzed,the foundation for the further study of belt transmission is laid.By using the ANSYS and ADAMS,the stress simulation and dynamics simulation of belt drive systems are carried out,and the correctness of the preliminary design of pulley drive system is validated,the technical support of the optimum design of deicing special vehicle is provided.The study of deicing special vehicle deicing efficiency has played a key role,which with better economic benefits and promotional value.%针对路面结冰对道路交通安全事故存在严重影响的现象,设计出了一款用于道路除冰的机械式除冰专用车,对其进行合理的设计与布局;主要研究机械铲冰装置的带传动系统,建立传送带的微元动力学方程,对带传动系统进行了理论分析;通过理论设计和工程设计算法对带传动的转矩和功率进行分析,为带传动进一步的研究奠定了基础;通过ANSYS和ADAMS对带传动系统分别进行应力仿真和动力学仿真,验证了初步设计的带轮传动系统的正确性,为除冰车的优化设计提供了技术支撑,对除冰车除冰效率的研究起到了关键的作用,具有较好的经济效益和推广价值.

  15. Analysis to Support Execution of the Defense Environmental International Cooperation (DEIC) Program

    Science.gov (United States)

    2012-05-01

    IDA Document D-4605 May 2012 Analysis to Support Execution of the Defense Environmental International Cooperation ( DEIC ) Program Susan L. Clark...Execution of the Defense Environmental International Cooperation ( DEIC ) Program Susan L. Clark-Sestak iii Executive Summary The Defense...Environmental International Cooperation ( DEIC ) program is managed by the Director of Environmental Readiness and Safety (ERS) in the Office of the Deputy

  16. Passive Anti-Icing and Active Deicing Films.

    Science.gov (United States)

    Wang, Tuo; Zheng, Yonghao; Raji, Abdul-Rahman O; Li, Yilun; Sikkema, William K A; Tour, James M

    2016-06-08

    Anti-icing and deicing are the two major pathways for suppressing adhesion of ice on surfaces, yet materials with dual capabilities are rare. In this work, we have designed a perfluorododecylated graphene nanoribbon (FDO-GNR) film that takes advantage of both the low polarizability of perfluorinated carbons and the intrinsic conductive nature of graphene nanoribbons. The FDO-GNR films are superhydrophobic with a sheet resistance below 8 kΩ·sq(-1) and then exhibit an anti-icing property that prevents freezing of incoming ice-cold water down to -14 °C. After that point, voltage can be applied to the films to resistively heat and deice the surface. Further a lubricating liquid can be employed to create a slippery surface to improve the film's deicing performance. The FDO-GNR films can be easily switched between the superhydrophobic anti-icing mode and the slippery deicing mode by applying the lubricant. A spray-coating method makes it suitable for large-scale applications. The anti-icing and deicing properties render the FDO-GNR films with promise for use in extreme environments.

  17. Nanoscale deicing by molecular dynamics simulation

    Science.gov (United States)

    Xiao, Senbo; He, Jianying; Zhang, Zhiliang

    2016-07-01

    Deicing is important to human activities in low-temperature circumstances, and is critical for combating the damage caused by excessive accumulation of ice. The aim of creating anti-icing materials, surfaces and applications relies on the understanding of fundamental nanoscale ice adhesion mechanics. Here in this study, we employ all-atom modeling and molecular dynamics simulation to investigate ice adhesion. We apply force to detach and shear nano-sized ice cubes for probing the determinants of atomistic adhesion mechanics, and at the same time investigate the mechanical effect of a sandwiched aqueous water layer between ice and substrates. We observe that high interfacial energy restricts ice mobility and increases both ice detaching and shearing stresses. We quantify up to a 60% decrease in ice adhesion strength by an aqueous water layer, and provide atomistic details that support previous experimental studies. Our results contribute quantitative comparison of nanoscale adhesion strength of ice on hydrophobic and hydrophilic surfaces, and supply for the first time theoretical references for understanding the mechanics at the atomistic origins of macroscale ice adhesion.Deicing is important to human activities in low-temperature circumstances, and is critical for combating the damage caused by excessive accumulation of ice. The aim of creating anti-icing materials, surfaces and applications relies on the understanding of fundamental nanoscale ice adhesion mechanics. Here in this study, we employ all-atom modeling and molecular dynamics simulation to investigate ice adhesion. We apply force to detach and shear nano-sized ice cubes for probing the determinants of atomistic adhesion mechanics, and at the same time investigate the mechanical effect of a sandwiched aqueous water layer between ice and substrates. We observe that high interfacial energy restricts ice mobility and increases both ice detaching and shearing stresses. We quantify up to a 60% decrease in ice

  18. Nanoscale deicing by molecular dynamics simulation.

    Science.gov (United States)

    Xiao, Senbo; He, Jianying; Zhang, Zhiliang

    2016-08-14

    Deicing is important to human activities in low-temperature circumstances, and is critical for combating the damage caused by excessive accumulation of ice. The aim of creating anti-icing materials, surfaces and applications relies on the understanding of fundamental nanoscale ice adhesion mechanics. Here in this study, we employ all-atom modeling and molecular dynamics simulation to investigate ice adhesion. We apply force to detach and shear nano-sized ice cubes for probing the determinants of atomistic adhesion mechanics, and at the same time investigate the mechanical effect of a sandwiched aqueous water layer between ice and substrates. We observe that high interfacial energy restricts ice mobility and increases both ice detaching and shearing stresses. We quantify up to a 60% decrease in ice adhesion strength by an aqueous water layer, and provide atomistic details that support previous experimental studies. Our results contribute quantitative comparison of nanoscale adhesion strength of ice on hydrophobic and hydrophilic surfaces, and supply for the first time theoretical references for understanding the mechanics at the atomistic origins of macroscale ice adhesion.

  19. Modeling and strain gauging of eddy current repulsion deicing systems

    Science.gov (United States)

    Smith, Samuel O.

    1993-01-01

    Work described in this paper confirms and extends work done by Zumwalt, et al., on a variety of in-flight deicing systems that use eddy current repulsion for repelling ice. Two such systems are known as electro-impulse deicing (EIDI) and the eddy current repulsion deicing strip (EDS). Mathematical models for these systems are discussed for their capabilities and limitations. The author duplicates a particular model of the EDS. Theoretical voltage, current, and force results are compared directly to experimental results. Dynamic strain measurements results are presented for the EDS system. Dynamic strain measurements near EDS or EIDI coils are complicated by the high magnetic fields in the vicinity of the coils. High magnetic fields induce false voltage signals out of the gages.

  20. Influence of Superhydrophobic Properties on Deicing

    Science.gov (United States)

    Nazhipkyzy, M.; Mansurov, Z. A.; Amirfazli, A.; Esbosin, A.; Temirgaliyeva, T. S.; Lesbayev, B. T.; Aliyev, E. T.; Prikhodko, N. G.

    2016-11-01

    Nowadays the creation of anti-icing, or deicing, surfaces is one of the most important problems, as such surfaces are widely used in aeronautics, wind turbines, and telecommunication antennas. In this paper, we focus mainly on reducing the ice adhesion forces and easy ice removal, once ice has formed. Removal of a liquid from a surface can be provided by modification of the surface wettability by means of applying superhydrophobic coatings. Such coatings are water-resistant, i.e., are characterized by low water adhesion forces. To study the impact of superhydrophobic coatings, tests were performed on the surface of a wing in a wind tunnel. By spraying Teflon and polyphenylene sulfide (PPS) on the wing, we obtained a superhydrophobic film. This film has a structure that provides superhydrophobic properties, so that the wetting angle is above 140°. A comparison of the resulting surface with a clean Teflon one shows that adhesion of the Teflon + PPS mixture to an aluminum surface is five times higher. We also investigate the degree of ice formation on the surfaces of simple and superhydrophobic aircraft wings at a temperature of -18°C. It was shown that ice was formed on a simple wing within 40 s and on a superhydrophobic wing within 25 s. When the simple wing with a mass of 23 g was inserted into the wind tunnel, its mass reached 50 g, and for a superhydrophobic wing with a mass of 26 g the latter reached 42 g. The sample of the airfoil wing we prepared has a low adhesion, which helps in easy ice removal.

  1. Demonstrate a Low Biochemical Oxygen Demand Aircraft Deicing Fluid

    Science.gov (United States)

    2013-06-01

    and hazardous proprietary additive materials such as corrosion inhibitors . Specifically, the test objectives were as follows: 1. Illustrate...concentrations of deicing fluids are known to cause acute aquatic toxicological effects, due mainly to additives (e.g., to improve corrosion inhibition... coats the aircraft surface in a smooth and consistent manner with no foam. Fluid has good wetting characteristics and exhibits no pitting

  2. Deicing with Nd:YAG and CO2 lasers

    Science.gov (United States)

    Qi, Lijun; Zhu, Xiao; Zhu, Changhong; Guo, Fei; Zhu, Guangzhi; Gu, Shanqiang

    2010-11-01

    A model of deicing with Nd:YAG and CO2 lasers for simulation using ANSYS software is presented. Experiments with a 300-W, 1-ms, 60-Hz Nd:YAG laser and a 500- to 2000-W cw CO2 laser are reported. The Nd:YAG laser is considered as a volume thermal source, and the CO2 laser as a plane thermal source. The model and the simulation results can describe both Nd:YAG and CO2 laser deicing well. The results of the simulation and experiments suggest that the melting rates for the two lasers are almost equal at the same laser power density. So are the melting efficiencies. The hard and transparent ice irradiated by the Nd:YAG laser becomes opaque and loose, because the thermal stress is distributed in the body of the ice, while the ice irradiated by the CO2 laser is still transparent and hard, because thermal stress hardly occurs. So the laser with characteristics of high output power and large ice absorbing length can be selected for the power line laser deicing system, and Nd:YAG laser is more appropriate for power-line deicing than CO2 laser.

  3. Identification of Salt Stress Biomarkers in Romanian Carpathian Populations of Picea abies (L. Karst.

    Directory of Open Access Journals (Sweden)

    Sorin T Schiop

    Full Text Available The Norway spruce (Picea abies, the most important tree species in European forests, is relatively sensitive to salt and does not grow in natural saline environments. Yet many trees are actually exposed to salt stress due to the common practice of de-icing of mountain roads in winter, using large amounts of NaCl. To help develop strategies for an appropriate use of reproductive seed material on reforestation sites, ensuring better chances of seedling survival in salt-affected areas, we have studied the responses of young spruce seedlings to salt treatments. The specific aim of the work was to identify the optimal salt stress biomarkers in Picea abies, using as experimental material seedlings obtained by germination of seeds with origin in seven populations from the Romanian Carpathian Mountains. These responses included general, conserved reactions such as the accumulation of ions and different osmolytes in the seedlings needles, reduction in photosynthetic pigments levels, or activation of antioxidant systems. Although changes in the contents of different compounds involved in these reactions can be associated to the degree of stress affecting the plants, we propose that the (decreasing levels of total phenolics or total carotenoids and the (increasing levels of Na+ or K+ ions in Picea abies needles, should be considered as the most reliable and useful biomarkers for salt stress in this species. They all show very high correlation with the intensity of salt stress, independently of the genetic background of the seeds parental population, and relatively easy, quantitative assays are available to determine their concentrations, requiring simple equipment and little amount of plant material.

  4. Identification of Salt Stress Biomarkers in Romanian Carpathian Populations of Picea abies (L.) Karst.

    Science.gov (United States)

    Schiop, Sorin T; Al Hassan, Mohamad; Sestras, Adriana F; Boscaiu, Monica; Sestras, Radu E; Vicente, Oscar

    2015-01-01

    The Norway spruce (Picea abies), the most important tree species in European forests, is relatively sensitive to salt and does not grow in natural saline environments. Yet many trees are actually exposed to salt stress due to the common practice of de-icing of mountain roads in winter, using large amounts of NaCl. To help develop strategies for an appropriate use of reproductive seed material on reforestation sites, ensuring better chances of seedling survival in salt-affected areas, we have studied the responses of young spruce seedlings to salt treatments. The specific aim of the work was to identify the optimal salt stress biomarkers in Picea abies, using as experimental material seedlings obtained by germination of seeds with origin in seven populations from the Romanian Carpathian Mountains. These responses included general, conserved reactions such as the accumulation of ions and different osmolytes in the seedlings needles, reduction in photosynthetic pigments levels, or activation of antioxidant systems. Although changes in the contents of different compounds involved in these reactions can be associated to the degree of stress affecting the plants, we propose that the (decreasing) levels of total phenolics or total carotenoids and the (increasing) levels of Na+ or K+ ions in Picea abies needles, should be considered as the most reliable and useful biomarkers for salt stress in this species. They all show very high correlation with the intensity of salt stress, independently of the genetic background of the seeds parental population, and relatively easy, quantitative assays are available to determine their concentrations, requiring simple equipment and little amount of plant material.

  5. 快速复合融除冰装置的研究%Research of Rapid Compound Deicing Equipment

    Institute of Scientific and Technical Information of China (English)

    朱自成; 张学军; 徐肖攀; 储伟俊; 李超新

    2014-01-01

    如何保证冰雪天气条件下交通顺畅、行车安全,提高道路通行能力和运营效益、减少和避免交通事故发生是当今面临的一大难题。为此,在分析现有不同除冰方法的基础上,提出一种融合热力-水射流切割融除冰与机械铣削除冰的复合除冰方法。介绍了热力快速复合融除冰装置和机械铣削除冰装置的结构组成、工作原理,设计了复合融除冰装置,并进行了相关试验。结果表明:该装置可以很好地完成融除冰任务,满足设计需求。%Determining how to strikingly reduce the accident rate on roads,ensure traffic flow and safety in the icy weather,and improve the capacity and efficiency of transportation in snow weather has become a tough issue nowadays.A new method was presented in which thermal water-jet cutting was combined with mechanical-milling deicing technology,basing on current different deicing meth-ods.Then the structure and working principle of this device were introduced,together with the practicality design.The experimental results indicate that this device can perform well in deicing work,and satisfy the design requirements.

  6. Effect of Graphene Coating on the Heat Transfer Performance of a Composite Anti-/Deicing Component

    Directory of Open Access Journals (Sweden)

    Long Chen

    2017-09-01

    Full Text Available The thermal conductivity of a graphene coating for anti-/deicing is rarely studied. This paper presents an improved anti-/deicing efficiency method for composite material anti-/deicing by using the heat-transfer characteristic of a graphene coating. An anti-/deicing experiment was conducted using the centrifugal force generated by a helicopter rotor. Results showed that the graphene coating can accelerate the internal heat transfer of the composite material, thereby improving the anti-icing and deicing efficiency of the helicopter rotor. The spraying process parameters, such as coating thickness and spraying pressure, were also studied. Results showed that reducing coating thickness and increasing spraying pressure are beneficial in preparing a graphene coating with high thermal conductivity. This study provides an experimental reference for the application of a graphene coating in anti-/deicing.

  7. Aerodynamic Effects Of Deicing And Anti-Icing Fluids

    Science.gov (United States)

    Addy, Harold E., Jr.; Runyan, L. James; Zierten, Thomas A.; Hill, Eugene G.

    1994-01-01

    Report presents results of wind-tunnel tests of aerodynamic effects of deicing and anti-icing fluids on airplane wings. Tests conducted on three-dimensional half-model airplane and two-dimensional airfoil model at temperatures ranging from -29 to +10 degrees C. Fluids used included three commercial fluids available for use during 1987-1988 winter season, one discontinued commercial fluid, and eight newer fluids experimental at time of test.

  8. Shape-Memory-Alloy-Based Deicing System Developed

    Science.gov (United States)

    1996-01-01

    Ice buildup on aircraft leading edge surfaces has historically been a problem. Most conventional deicing systems rely either on surface heating to melt the accreted ice or pneumatic surface inflation to mechanically debond the ice. Deicers that rely solely on surface heating require large amounts of power. Pneumatic deicers usually cannot remove thin layers of ice and lack durability. Thus, there is a need for an advanced, low-power ice protection system. As part of the NASA Small Business and Innovation Research (SBIR) program, Innovative Dynamics, Inc., developed an aircraft deicing system that utilizes the properties of Shape Memory Alloys (SMA). The SMA-based system has achieved promising improvements in energy efficiency and durability over more conventional deicers. When they are thermally activated, SMA materials change shape; this is analogous to a conventional thermal expansion. The thermal input is currently applied via conventional technology, but there are plans to implement a passive thermal input that is supplied from the energy transfer due to the formation of the ice itself. The actively powered deicer was tested in the NASA Lewis Icing Research Tunnel on a powered rotating rig in early 1995. The system showed promise, deicing both rime and glaze ice shapes as thin as 1/8 in. The first prototype SMA deicer reduced power usage by 45 percent over existing electrothermal systems. This prototype system was targeted for rotorcraft system development. However, there are current plans underway to develop a fixed-wing version of the deicer.

  9. A basic approach for wing leading deicing by smart structures

    Science.gov (United States)

    Struggl, Stephan; Korak, Johannes; Feyrer, Christoph

    2011-04-01

    An investigation regarding de-icing of wing leading edges through the use of smart structures is performed. Piezoelectric actuators are used to excite the structures at their natural frequencies. This vibration excites shear stresses at the surface, which lead to the shedding off of ice. For optimal excitation of the structure, the frequency and the placement of piezo elements are determined, in order to maximize the shear stress. First, experimental investigations on a clamped aluminum plate are carried out. With these findings, the transition to an aluminum sample of a wing leading edge is performed. Practical experiments have been carried out on a sample of an aluminum wing leading edge. First, the structural behavior is determined by a modal analysis so that the natural frequencies and the eigenmodes can be calculated. By FE simulation all parameter combinations can be calculated, so the practical tests can be adapted accordingly. Practical experiments have been carried out under realistic conditions in terms of ice formation in an icing research tunnel. Different types of ice have been considered, which require a different level of shear stresses for the de-icing. Further investigations will concern the determination of the suitable frequency and furthermore an ongoing monitoring of the process to take up account on different icing conditions. The studies point to a further possibility of energy efficient de-icing.

  10. Detection of triazole deicing additives in soil samples from airports with low, mid, and large volume aircraft deicing activities.

    Science.gov (United States)

    McNeill, K S; Cancilla, D A

    2009-03-01

    Soil samples from three USA airports representing low, mid, and large volume users of aircraft deicing fluids (ADAFs) were analyzed by LC/MS/MS for the presence of triazoles, a class of corrosion inhibitors historically used in ADAFs. Triazoles, specifically the 4-methyl-1H-benzotriazole and the 5-methyl-1H-benzotriazole, were detected in a majority of samples and ranged from 2.35 to 424.19 microg/kg. Previous studies have focused primarily on ground and surface water impacts of larger volume ADAF users. The detection of triazoles in soils at low volume ADAF use airports suggests that deicing activities may have a broader environmental impact than previously considered.

  11. Recovery of salts from ion-exchange regeneration streams by a coupled nanofiltration-membrane distillation process.

    Science.gov (United States)

    Jiříček, Tomáš; De Schepper, Wim; Lederer, Tomáš; Cauwenberg, Peter; Genné, Inge

    2015-01-01

    Ion-exchange tap water demineralization for process water preparation results in a saline regeneration wastewater (20-100 mS cm(-1)) that is increasingly problematic in view of discharge. A coupled nanofiltration-membrane distillation (NF-MD) process is evaluated for the recovery of water and sodium chloride from this wastewater. NF-MD treatment of mixed regeneration wastewater is compared to NF-MD treatment of separate anion- and cation-regenerate fractions. NF on mixed regeneration wastewater results in a higher flux (30 L m(-2) h(-1) at 7 bar) compared to NF on the separate fractions (6-9 L m(-2) h(-1) at 30 bar). NF permeate recovery is strongly limited by scaling (50% for separate and 60% for mixed, respectively). Physical signs of scaling were found during MD treatment of the NF permeates but did not result in flux decline for mixed regeneration wastewater. Final salt composition is expected to qualify as a road de-icing salt. NF-MD is an economically viable alternative compared to external disposal of wastewater for larger-scale installations (1.4 versus 2.5 euro m(-3) produced demineralized water for a 10 m3 regenerate per day plant). The cost benefits of water re-use and salt recuperation are small when compared to total treatment costs for mixed regenerate wastewater.

  12. Single Neuron PID Control of Aircraft Deicing Fluids Rapid Heating System

    Directory of Open Access Journals (Sweden)

    Bin Chen

    2013-02-01

    Full Text Available Aircraft deicing fluids rapid heating system is widely used in aircraft ground deicing to ensure that the operation of flights can be safe and efficient. Aiming at the temperature turbulence problem of aircraft deicing system, this paper presents the single neuron PID control strategy which combine the advantage of conventional PID control with artificial neuron control. The aircraft deicing fluids rapid heating system and the scheme and working principle of the system is introduced. Simulation is executed on the basis of the mathematical model of aircraft deicing fluids rapid heating system, which is built in this paper, according to a number of data collected by experiments which are operated on the experimental platform of deicing fluids rapid heating system. The simulation results show that the single neuron PID control strategy perform effectively on the temperature turbulence problem of aircraft deicing fluids rapid heating system. Experiments are conducted to vertify the single neuron PID control strategy, the results of which show that the single neuron PID control strategy can achieve the request in practical application of the aircraft deicing fluids rapid heating system.

  13. Improved management of winter operations to limit subsurface contamination with degradable deicing chemicals in cold regions

    NARCIS (Netherlands)

    French, H.K.; Zee, van der S.E.A.T.M.

    2014-01-01

    This paper gives an overview of management considerations required for better control of deicing chemicals in the unsaturated zone at sites with winter maintenance operations in cold regions. Degradable organic deicing chemicals are the main focus. The importance of the heterogeneity of both the inf

  14. 14 CFR 23.1099 - Carburetor deicing fluid system detail design.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Carburetor deicing fluid system detail design. 23.1099 Section 23.1099 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Powerplant Induction System § 23.1099 Carburetor deicing fluid system detail design. Each carburetor...

  15. Power Grid De-icing Optimal Plan Based on Fractional Sieve Method

    Science.gov (United States)

    Xie, Guangbin; Lin, Meihan; Li, Huaqiang

    2017-05-01

    Aiming at the problem that the reliability of system was reduced and the security risk was increased during the DC de-icing period, a decision-making model based on the fractional sieve method was proposed. This model introduced risk assessment theory, and took into account the comprehensive failure probability model of protection action and ice cover. Considering the de-icing condition, a DC de-icing strategy model, which was with the objective function of minimizing the load of shedding and minimizing the operating risk, was proposed. The objective function was optimized by particle swarm optimization algorithm and fractional sieve method. The simulative results of IEEE30-bus system indicated that the load loss caused by de-icing and the operational risk of the system could be effectively reduced by the proposed model. It provided a reference for power department to make a de-icing plan.

  16. Thermal de-icing of HV conductors by using an external DC source

    Energy Technology Data Exchange (ETDEWEB)

    Breault, S.; Prud' homme, P. [Hydro-Quebec, PQ (Canada). TransEnergie Div.

    2002-07-01

    The Research Institute of Hydro-Quebec is conducting 2 test programs in climatic chambers. It is also compiling a database for conductors, ground wires and optical power ground wires (OPGW). An in-house computer program has also been developed to evaluate de-icing using the Joule effect. Maps illustrating the power transmission network for the entire province were presented. It was shown that de-icing requires 1800 A per every 735 kV conductor. This upper limit is fixed by the thermal rating of the line. The longest line to be de-iced in Quebec is about 250 km long. This would require 850 kV and 6000 MVA of power. The basic de-icing configuration at 315 kV was also illustrated, along with a simulation of the impact of de-icing on ice loading of power lines.

  17. Effects of the Exposure to Corrosive Salts on the Frictional Behavior of Gray Cast Iron and a Titanium-Based Metal Matrix Composite

    Energy Technology Data Exchange (ETDEWEB)

    Blau, Peter Julian [ORNL; Truhan, Jr., John J [ORNL; Kenik, Edward A [ORNL

    2007-01-01

    The introduction of increasingly aggressive road-deicing chemicals has created significant and costly corrosion problems for the trucking industry. From a tribological perspective, corrosion of the sliding surfaces of brakes after exposure to road salts can create oxide scales on the surfaces that affect friction. This paper describes experiments on the effects of exposure to sodium chloride and magnesium chloride sprays on the transient frictional behavior of cast iron and a titanium-based composite sliding against a commercial brake lining material. Corrosion scales on cast iron initially act as abrasive third-bodies, then they become crushed, spread out, and behave as a solid lubricant. The composition and subsurface microstructures of the corrosion products on the cast iron were analyzed. Owing to its greater corrosion resistance, the titanium composite remained scale-free and its frictional response was markedly different. No corrosion scales were formed on the titanium composite after aggressive exposure to salts; however, a reduction in friction was still observed. Unlike the crystalline sodium chloride deposits that tended to remain dry, hygroscopic magnesium chloride deposits absorbed ambient moisture from the air, liquefied, and retained a persistent lubricating effect on the titanium surfaces.

  18. Corrosion effects of runway de-icing chemicals on aircraft alloys and coatings

    Energy Technology Data Exchange (ETDEWEB)

    Huttunen-Saarivirta, E., E-mail: elina.huttunen-saarivirta@tut.fi [Department of Materials Science, Tampere University of Technology, P.O. Box 589, FI-33101 Tampere (Finland); Kuokkala, V.-T.; Kokkonen, J. [Department of Materials Science, Tampere University of Technology, P.O. Box 589, FI-33101 Tampere (Finland); Paajanen, H. [Finnish Air Force Materiel Command, Plans Division, Support Systems Section, P.O. Box 210, FI-33101 Tampere (Finland)

    2011-03-15

    Research highlights: {yields} Corrosion effects of urea and four new runway de-icing chemicals on Al alloy 2024, Mg alloy RZ5 and cadmium-plated and subsequently chromate-treated steel 4340 were examined by three types of corrosion tests. {yields} Corrosion effects of urea on Al alloy 2024 were more pronounced than those of the new de-icing chemicals, with pitting corrosion being evident in urea in all tests. {yields} The rate of corrosion in Mg alloy RZ5 was often higher in new de-icing chemicals than in urea, although the form of corrosion was the same in most cases, i.e., general corrosion. {yields} Corrosion effects of the five runway de-icing chemicals on cadmium-plated and subsequently chromate-treated steel 4340 were slightly different in all three tests, but some loss of the coating layers was detected in all cases. - Abstract: Corrosion effects of five runway de-icing chemicals on aluminium alloy 2024, magnesium alloy RZ5 and cadmium-plated and subsequently chromate-treated steel 4340 were investigated by cyclic polarisation measurements, open circuit potential monitoring and cyclic chemical exposure tests. The runway de-icing chemicals included in the study contained urea, which has a long history as a runway de-icing chemical, and four new commercial de-icing chemicals, which were based on betaine and potassium formate. Corrosion effects of urea on aluminium alloy 2024 were more pronounced than those of the new de-icing chemicals. In urea, the breakdown potential, indicating the onset of pitting, was clearly distinguishable in the cyclic polarisation curve and pitting corrosion was detected on the specimen surface after all three types of tests. Weight losses during the chemical exposure tests were also higher for urea than for the other four chemicals, where pitting corrosion was only occasionally detected. The opposite was true in the case of magnesium alloy RZ5: although the alloy experienced general corrosion in each de-icing chemical included in the

  19. Flexural waves induced by electro-impulse deicing forces

    Science.gov (United States)

    Gien, P. H.

    1990-01-01

    The generation, reflection and propagation of flexural waves created by electroimpulsive deicing forces are demonstrated both experimentally and analytically in a thin circular plate and a thin semicylindrical shell. Analytical prediction of these waves with finite element models shows good correlation with acceleration and displacement measurements at discrete points on the structures studied. However, sensitivity to spurious flexural waves resulting from the spatial discretization of the structures is shown to be significant. Consideration is also given to composite structures as an extension of these studies.

  20. WHIPICE. [Computer Program for Analysis of Aircraft Deicing

    Science.gov (United States)

    1992-01-01

    This video documents efforts by NASA Lewis Research Center researchers to improve ice protection for aircraft. A new system of deicing aircraft by allowing a thin sheet of ice to develop, then breaking it into particles, is being examined, particularly to determine the extent of shed ice ingestion by jet engines that results. The process is documented by a high speed imaging system that scans the breakup and flow of the ice particles at 1000 frames per second. This data is then digitized and analyzed using a computer program called WHIPICE, which analyzes grey scale images of the ice particles. Detailed description of the operation of this computer program is provided.

  1. A Cool Tool for Deicing Planes

    Science.gov (United States)

    2001-01-01

    Nicknamed the "ice zapper," the Electro Expulsive Separation System (EESS) is an aircraft ice removal system that "pulverizes ice and removes layers of ice as thin as frost or as thick as an inch of glaze," according to the principle inventor of the technology. Patented by NASA's Ames Research Center, the EESS consists of layers of conductors encased in materials that are bonded directly to the airframe structure. When ice accumulates on the aircraft, an electric current is sent through the conductors, causing them to pulse. Even though the conductors move less than a twenty-thousandth of an inch in just a millisecond, the movement is sufficient to pulverize the ice. It is this highly accelerated motion that shatters the ice into particles the size of table salt; too small to be harmful to the aircraft. When compared with other systems in use, such as thermal deicers and pneumatic boots, the ice zapper does very well. Thermal deicers are fairly common, although they use an enormous amount of energy and present the possibility of ice refreezing. Pneumatic boots are not always effective because they require an inflation device that is unable to work until a quarter inch of ice has accumulated. With both systems, the ice that is loosened may still be large enough to cause problems for the plane once dislodged.

  2. Scheduling de-icing vehicles within airport logistics: a heuristic algorithm and performance evaluation

    OpenAIRE

    2012-01-01

    Most delays in the air transport occur at the airport. A particular reason is the complexity of managing the large number of supporting flows in airport logistics. We consider the optimisation problem of scheduling de-icing vehicles that is one of the key supporting logistic flows in the turn-around process of aircraft. The objective is to minimise the delay of flights due to de-icing, and the travel distance of the de-icing vehicles. We study the complexity of the problem, and develop a solu...

  3. Surface roughness due to residual ice in the use of low power deicing systems

    Science.gov (United States)

    Shin, Jaiwon; Bond, Thomas H.

    1993-01-01

    Thicknesses of residual ice are presented to provide information on surface contamination and associated roughness during deicing events. Data was obtained from low power ice protection systems tests conducted in the Icing Research Tunnel at NASA Lewis Research Center (LeRC) with nine different deicing systems. Results show that roughness associated with residual ice is not characterized by uniformly distributed roughness. Results also show that deicing systems require a critical mass of ice to generate a sufficient expelling force to remove the ice.

  4. Experimental Study on Deicing Performance of Carbon Fiber Reinforced Conductive Concrete

    Institute of Scientific and Technical Information of China (English)

    Zuquan TANG; Zhuoqiu LI; Jueshi QIAN; Kejin WANG

    2005-01-01

    Carbon fiber reinforced concrete (CFRC) is a kind of good electrothermal material. When connected to an external power supply, stable and uniform heat suitable for deicing application is generated in the CFRC slab. Electric heating and deicing experiments of carbon fiber reinforced concrete slab were carried out in laboratory, and the effect of the temperature and thickness of ice, the thermal conductivity of CFRC, and power output on deicing performance and energy consumption were investigated. The experimental results indicate that it is an effective method to utilize the thermal energy produced by CFRC slab to deice. The time to melt the ice completely decreases with increasing power output and ice temperature, and increases with increasing thickness of the ice. The energy consumption to ranges from -3℃ to -18℃. CFRC with good thermal conduction can reduce temperature difference in CFRC slab effectively.

  5. Miscellaneous Roads

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data set contains roadway centerlines for miscellanous roads, a catch-all category for all road types not present in the other DNR derived products. These road...

  6. Physical Basis of Power Transmission Wire’s Deicing by Electrodynamic Method

    Directory of Open Access Journals (Sweden)

    Lyapunov Danil Yu.

    2014-01-01

    Full Text Available In this paper a new method of power transmission wire’’s deicing is described. Deicing process is divided into three independent sub-processes, namely the process of melting the thin inner layer of ice cover, the process of ice cylinder fracturing into components due to bending deformations; the process of shaking off the fractured ice cylinder elements by inertial forces. Mathematical description of each sub-process is shown.

  7. A numerical and experimental investigation of electrothermal aircraft deicing

    Science.gov (United States)

    Leffel, K.; Masiulaniec, K. C.; Dewitt, K. J.; Keith, T. G., Jr.

    1986-01-01

    Experimental data were obtained for the deicing characteristics of a stationary UH-1H helicopter blade which had been fitted with an electrothermal deicer assembly. The tests were run in the NASA Lewis Icing Research Tunnel, and yielded transient temperature responses for the substrate, heater and abrasion shield at selected positions around the blade. The data at the abrasion shield-ice interface clearly documented when melting, shedding or refreezing occurred. Comparisons were made between the experimental data and a one-dimensional numerical model. The agreement was generally very good, with the simulations being shown to be capable of predicting the transient temperature responses along with phase change and ice shedding. At many blade positions, the model was capable of accurately simulating the thermal response of the electrothermal deicer assembly.

  8. 路面融雪化冰模型装置试验研究%Experimental study on the device of deicing and snow-melting model for the pavement

    Institute of Scientific and Technical Information of China (English)

    王宇军; 常睿; 岳卫民

    2016-01-01

    This paper established a small road testing system of deicing and snow melting,and analyzing the law of heat-conduction in the con-crete through the temperature change in different parts,and based on this,temperature distribution of structure layer and road surface,the as-cending rule of temperature and snow melting effect of the preheating time were researched theoretically. It provides reference and basis for dei-cing and snow-melting of road.%针对路面融雪化冰现象,建立了一个小型道路融雪化冰试验系统,通过不同部位温度变化情况,分析了热量在混凝土中的传导规律,并在此基础上,对结构层内温度场、上表面温度分布和升温规律、预热时间融雪效果进行了理论研究,为道路融雪化冰提供参考和依据。

  9. Strabo's roads

    DEFF Research Database (Denmark)

    Bekker-Nielsen, Tønnes

    2017-01-01

    in the Geography, and the world-view, of Strabo. Strabo did not take much interest in roads as artefacts or monuments, in the technology of road construction, or in the mythological and historical background of individual roads. He is primarily interested in roads from a functional point of view. For the general...

  10. Preliminary Inquiry of Salt and Frost Heave Deformation on Urban Road in Alar%阿拉尔市区道路盐-冻胀变形破坏初探

    Institute of Scientific and Technical Information of China (English)

    张灵通; 杨保存; 李寿宁

    2016-01-01

    南疆城市阿拉尔市区的沥青混凝土道路每年冬-春就会出现不同程度的变形破坏现象,通过对虹桥路试验路段不同深度路基结构层及一侧绿化带内相应深度取土样,运用SEM微观电镜观测土样微观结构发现:路基水泥土稳定层膨胀疏松,掺杂着大量具有膨胀作用的硫酸钠晶体和硫酸钙晶体,而其他结构层很少,绿化带土样则几乎观测不到,表明水泥土稳定层发生膨胀是导致沥青混凝土道路变形破坏的主要因素。对路基内盐分及温度、路面竖向变形、地下水位变化分析得知,路基内盐-温-水共同作用是促使水稳层产生膨胀变形的因素,因此对于该地区道路工程应做好控温限盐防水的措施。%There are different degrees of deformation on the urban road asphalt concrete every winter and spring in Alar, a city in southern Xinjiang. Soil samples are taken from different depth of subgrade structure layers and one side of the green belt in Hongqiao Road test section. Its micro structure with SEM scanning display that subgrade soil cement stabi⁃lized layer is expanded and loose, mixed with a large number of expanded elements such as sodium sulfate and calcium sulfate crystal, which are few in other layers, and almost none in green belt. The results show that the expansion of soil ce⁃ment stabilized layer is the main factor of asphalt concrete pavement deformation. Analysis of the salt, temperature, verti⁃cal deformation in subgrade pavement and changes of underground water level prove that the interaction of salt-tempera⁃ture-water in subgrade promotes the expansion of the water layer, so it is better to control the temperature and salt, and take water proofing measures for road engineering in this area.

  11. 氯盐融雪剂对城市道路绿化带土壤性状的影响%Effect of Snow Melt Agent Containing Chloride-salt on Soil Chemical Characters of Urban Road Greenbelt

    Institute of Scientific and Technical Information of China (English)

    王艳春; 白雪薇; 李芳

    2011-01-01

    2009年底至2010年初,北京市降雪非常集中且强度较大,为保障交通畅通,大量的氯盐融雪剂在北京城区的绿地上应用,其用量达3万t.路面撒施的融雪剂不可避免地进入分车带、绿化带等绿地,对绿地植物正常生长造成威胁.文章通过实地采集了45个绿地土样,研究了道路绿地土壤盐分等相关指标,结果表明,与对照相比,撒施融雪剂对道路绿化带土壤造成了严重的污染,土壤全盐量范围为0.11%~2.79%,最高值出现在西城区金融街;表层土壤氯化物含量范围为222~19 548 mg/kg;表层土壤水溶性钠分别达到了对照的18~780倍.从不同土层来看,0~10 cm的表层土壤全盐量、氯化物、水溶性钠的含量远远高于10~20 cm土层;地理分布上呈现出中心城区表层土壤全盐量总体高于外围城区,交通主干道高于次干道和交通支线的特点.最后,提出了减缓氯盐融雪剂危害的建议措施.%There were several heavy snowfalls during winter of 2009-2010 in Beijing and nearly 30,000 tons of snow melt agent containing chloride salt were used to guarantee the smooth and safe traffic flow. Snow melt agent containing chloride salt inevitably entered the greenbelt soil by the road, which* greatly threatened the growth of plants. Soil salt and chloride content were studied and analyzed after typical greenbelt soil samples were collected from main arterial traffic such as the 2nd, 3rd and 4th rings road. Results showed that snow melt agent containing chloride salt had caused serious soil pollution and soil salt, chloride and water soluble sodium content greatly increased, compared to check soil, with the highest salt content of 2.79% in Beijing Financial Street, chloride content in surface soil as 222 ~19,548mg/kg. Water soluble sodium content reached 18-780 times of the check. The contents of investigated indexes in surface soil (0-10 cm) were greatly higher than that in 10-20 cm soil. Central

  12. ROAD SAFETY

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Every year a lot of people are killed or injured in road accidents.How can we make the roads safer?Remember the following traffic rules. When you ride a bike,keep to the right side of the road.Don't cross the road or turn left at a red traffic light.Give a hand signal if you want to turn or stop. Before crossing the road,stop and look both ways,right and left.If the road is

  13. Wind Tunnel Study of the Electro-Thermal De-Icing of Wind Turbine Blades

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, C.; Ilinca, A.; Fortin, G.; Perron, J. [Anti-icing Materials International Laboratory, Universite du Quebec a Chicoutimi, Quebec, Canada and Wind Energy Group, Universite du Quebec a Rimouski, Quebec (Canada)

    2007-07-01

    Most of the wind turbines operating in cold climates are facing icing events but very few of them are equipped with blade de-icing systems. Few studies were performed and published on the characteristics of these de-icing systems. In order to optimize the design and power consumption of an electro-thermal de-icing system for wind turbine blades, an experimental set-up was built and used to test the system under icing conditions in a refrigerated wind tunnel. The parameters of the de-icing control system consider only the convective heat transfer at the blade surface during ice accretion. Meteorological data are those gathered from Murdochville's experimental site in Canada. The blade airfoil is a NACA 63 415 and the icing conditions are scaled to be simulated in the icing wind tunnel section. The results show the relation between the meteorological conditions, the ridge formed by liquid water runback, the heating power and the airfoil surface temperature. The study provides useful data for the design of electro-thermal deicing systems for wind turbine blade application.

  14. Road density

    Data.gov (United States)

    U.S. Environmental Protection Agency — Road density is generally highly correlated with amount of developed land cover. High road densities usually indicate high levels of ecological disturbance. More...

  15. Overhead Transmission Lines Deicing under Different Incentive Displacement

    Directory of Open Access Journals (Sweden)

    Qing He

    2014-01-01

    Full Text Available Overhead transmission line icing is one of the main factors affecting safety and reliability of power grid. This paper proposed an excitation deicing method of iced wire and theoretically revealed the ice removal mechanism under displacement excitation conditions, by taking the LGJ-70/10 glaze icing wire as the 3D model and analyzing and studying its dynamic response under the effect of displacement excitation. The simulation results show that the stress of wire icing area is enlarged with the increase of excitation displacement and frequency. Through the comparison of the compression strength experimental results on a series of different iced wires in low temperature environment, the authors found out that the stress generated from the wire icing area is greater than the crushing strength of the ice within the scope of the calculation parameters, which proved the validity and the feasibility of the method, and finally the suitable excitation displacement is determined. Following studies show that, as far as possible, it is necessary to reduce the incentive displacement and also to select the appropriate constraint length in order to avoid the line jumping that may be caused by large span ice shedding.

  16. Road Safety

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Every day we all use roads. We walk on them. We walk eitheralong the pavement (人行道)or across the road. If we are careless, wecan cause accidents.Accidents often happen when people arecrossing the road. Here is some advice.

  17. Assessment of water quality, road runoff, and bulk atmospheric deposition, Guanella Pass area, Clear Creek and Park Counties, Colorado, water years 1995-97

    Science.gov (United States)

    Stevens, Michael R.

    2001-01-01

    phytoplankton in the lakes were probably phosphorus-limited. Measures of trophic status (secchi depth, total phosphorus, and chlorophyll-a) indicated that Duck and Clear Lakes were oligotrophic in 1997.Ground water had relatively low specific conductance (range 24 to 584 microsiemens per centimeter) and did not exceed U.S. Environmental Protection Agency drinking-water standards, except for samples collected from a single well, which exceeded the Proposed Maximum Contaminant Level for uranium.Runoff from the Guanella Pass road enters streams through surface channels connected to culverts and roadside ditches. Fifty-six percent of the total number of culvert and roadside-ditch drainage features on the Guanella Pass road showed evidence of recent surface runoff connection to an adjacent stream. Road runoff is generated during snowmelt and during summer rainstorms.At a road cross-drain culvert monitored continuously for discharge (water years 1996-97), most runoff (77 to 96 percent) was a result of snowmelt, and runoff from the road preceded the basinwide peak streamflow, resulting in sediment and water-quality constituent inputs to the stream when the stream?s capacity for dilution of the road runoff was low. Specific conductance of road-runoff samples ranged from 14 to 468 microsiemens per centimeter. Major-ion composition of some samples indicated effects from deicing salt (sodium chloride) and dust inhibitor (magnesium chloride) applied to sections of the road, but changes in the stream concentrations that might be attributed to the runoff were brief and relatively small.Nutrients were commonly measured in road-runoff samples at larger concentrations than in streamflow. Concentrations of nitrate and ammonia, especially during rainfall-generated road runoff, were more similar to the concentrations in precipitation than to the concentrations in stream water. Concentrations of ammonia plus organic nitrogen (total as N) (range less than 0.2 to 24 milligrams per liter) and t

  18. Water droplet behavior on superhydrophobic SiO2 nanocomposite films during icing/deicing cycles

    NARCIS (Netherlands)

    Lazauskas, A.; Guobiene, A.; Prosycevas, I.; Baltrusaitis, V.; Grigaliunas, V.; Narmontas, P.; Baltrusaitis, Jonas

    2013-01-01

    This work investigates water droplet behavior on superhydrophobic (water contact angle value of 162 ± 1°) SiO2 nanocomposite films subjected to repetitive icing/deicing treatments, changes in SiO2 nanocomposite film surface morphology and their non-wetting characteristics. During the experiment, wat

  19. Water droplet behavior on superhydrophobic SiO2 nanocomposite films during icing/deicing cycles

    NARCIS (Netherlands)

    Lazauskas, A.; Guobiene, A.; Prosycevas, I.; Baltrusaitis, V.; Grigaliunas, V.; Narmontas, P.; Baltrusaitis, J.

    2013-01-01

    This work investigates water droplet behavior on superhydrophobic (water contact angle value of 162 ± 1°) SiO2 nanocomposite films subjected to repetitive icing/deicing treatments, changes in SiO2 nanocomposite film surface morphology and their non-wetting characteristics. During the experiment, wat

  20. Water droplet behavior on superhydrophobic SiO2 nanocomposite films during icing/deicing cycles

    NARCIS (Netherlands)

    Lazauskas, A.; Guobiene, A.; Prosycevas, I.; Baltrusaitis, V.; Grigaliunas, V.; Narmontas, P.; Baltrusaitis, Jonas

    2013-01-01

    This work investigates water droplet behavior on superhydrophobic (water contact angle value of 162 ± 1°) SiO2 nanocomposite films subjected to repetitive icing/deicing treatments, changes in SiO2 nanocomposite film surface morphology and their non-wetting characteristics. During the experiment,

  1. Traffic Accidents on Slippery Roads

    DEFF Research Database (Denmark)

    Fonnesbech, J. K.; Bolet, Lars

    2014-01-01

    Police registrations from 65 accidents on slippery roads in normally Danish winters have been studied. The study showed: • 1 accident per 100 km when using brine spread with nozzles • 2 accidents per 100 km when using pre wetted salt • 3 accidents per 100 km when using kombi spreaders The results...

  2. A new system of snow-melting and deicing%一种新型的融雪化冰系统

    Institute of Scientific and Technical Information of China (English)

    侯雪梅

    2014-01-01

    Based on the technology of ice and snow melting processes through the heating power, a new system for snow melting or deicing is designed.Four units of the new system including heat production,heat insulation and thermal conductivity,and control part are integrated ingen-iously.In this new system heat is generated by heating cable,and heat is transferred evenly to the road by composite carbon with foam glass to insulate heating power.Experimental analysis on road table temperature,melting ice dynamics and heat insulation performance show that the effect of ice and snow melting is good with less heat loss in the process of the whole running system.%基于热力融雪化冰技术,研发设计一种新型融雪化冰系统。该系统由发热、隔热、导热以及控制模块四部分组成。利用发热电缆产生热量,用复合碳进行热量的均匀传导,并采用泡沫玻璃进行隔热。通过路表温度、融冰动力学和隔热性能实验分析,该系统融雪化冰效果较好,且在整个运行过程中系统热损耗较小。

  3. Water droplet behavior on superhydrophobic SiO{sub 2} nanocomposite films during icing/deicing cycles

    Energy Technology Data Exchange (ETDEWEB)

    Lazauskas, A., E-mail: Algirdas.LAZAUSKAS@stud.ktu.lt [Institute of Materials Science, Kaunas University of Technology, Savanorių 271, 3009 Kaunas (Lithuania); Guobienė, A., E-mail: Asta.GUOBIENE@ktu.lt [Institute of Materials Science, Kaunas University of Technology, Savanorių 271, 3009 Kaunas (Lithuania); Prosyčevas, I., E-mail: IGORPROS@mail.ru [Institute of Materials Science, Kaunas University of Technology, Savanorių 271, 3009 Kaunas (Lithuania); Baltrušaitis, V., E-mail: fei@fei.lt [Institute of Materials Science, Kaunas University of Technology, Savanorių 271, 3009 Kaunas (Lithuania); Grigaliūnas, V., E-mail: Viktoras.GRIGALIUNAS@ktu.lt [Institute of Materials Science, Kaunas University of Technology, Savanorių 271, 3009 Kaunas (Lithuania); Narmontas, P., E-mail: Pranas.NARMONTAS@ktu.lt [Institute of Materials Science, Kaunas University of Technology, Savanorių 271, 3009 Kaunas (Lithuania); Baltrusaitis, J., E-mail: j.baltrusaitis@utwente.nl [PhotoCatalytic Synthesis Group, University of Twente, Meander 229, P.O. Box 217, 7500 AE Enschede (Netherlands)

    2013-08-15

    This work investigates water droplet behavior on superhydrophobic (water contact angle value of 162 ± 1°) SiO{sub 2} nanocomposite films subjected to repetitive icing/deicing treatments, changes in SiO{sub 2} nanocomposite film surface morphology and their non-wetting characteristics. During the experiment, water droplets on SiO{sub 2} nanocomposite film surface are subjected to a series of icing and deicing cycles in a humid (∼ 70% relative humidity) atmosphere and the resulting morphological changes are monitored and characterized using atomic force microscopy (AFM) and contact angle measurements. Our data show that the formation of the frozen or thawed water droplet, with no further shape change, on superhydrophobic SiO{sub 2} nanocomposite film, is obtained faster within each cycle as the number of the icing/deicing cycles increases. After 10 icing and deicing cycles, the superhydrophobic SiO{sub 2} nanocomposite film had a water contact angle value of 146 ± 2° which is effectively non-superhydrophobic. AFM analysis showed that the superhydrophobic SiO{sub 2} nanocomposite film surface area under the water droplet undergoes gradual mechanical damage during the repetitive icing/deicing cycles. We propose a possible mechanism of the morphological changes to the film surface that take place during the consecutive icing/deicing experiments. - Highlights: • Superhydrophobic film is subjected to repetitive icing/deicing treatments. • Water droplet shape transition is recorded and characterized thereafter. • Atomic force microscopy and contact angle measurements are performed. • The surface undergoes gradual mechanical damage during repetitive icing/deicing. • Mechanism for the observed surface morphological changes is suggested.

  4. A novel actuator phasing method for ultrasonic de-icing of aircraft structures

    Science.gov (United States)

    Borigo, Cody J.

    Aircraft icing is a critical concern for commercial and military rotorcraft and fixed-wing aircraft. In-flight icing can lead to dramatic decreases in lift and increases in drag that have caused more than a thousand deaths and hundreds of accidents over the past three decades alone. Current ice protection technologies have substantial drawbacks due to weight, power consumption, environmental concerns, or incompatibility with certain structures. In this research, an actuator phasing method for ultrasonic de-icing of aircraft structures was developed and tested using a series of finite element models, 3D scanning laser Doppler vibrometer measurements, and experimental de-icing tests on metallic and composite structures including plates and airfoils. An independent actuator analysis method was developed to allow for practical evaluation of many actuator phasing scenarios using a limited number of finite element models by properly calculating the phased stress fields and electromechanical impedance curves using a complex coupled impedance model. A genetic algorithm was utilized in conjunction with a series of finite element models to demonstrate that phase inversion, in which only in-phase and anti-phase signal components are applied to actuators, can be utilized with a small number of phasing combinations to achieve substantial improvements in de-icing system coverage. Finite element models of a 48"-long airfoil predicted that phase inversion with frequency sweeping can provide an improvement in the shear stress coverage levels of up to 90% compared to frequency sweeping alone. Experimental evaluation of the phasing approach on an icing grid showed a 189% improvement in de-icing coverage compared to frequency sweeping alone at comparable power levels. 3D scanning laser Doppler vibrometer measurements confirmed the increased variation in the surface vibration field induced by actuator phasing compared to unphased frequency sweeping. Additional contributions were made

  5. Road works and road safety.

    NARCIS (Netherlands)

    2008-01-01

    Roadworks can cause dangerous situations for both road users and road workers. In the period 2000-2009, 2% of all registered fatal crashes in the Netherlands took place at roadworks. In addition, roadworks seem to increase the crash rate. Lorries are relatively often involved in crashes at roadworks

  6. Road works and road safety.

    NARCIS (Netherlands)

    2008-01-01

    Roadworks can cause dangerous situations for both road users and road workers. In the period 2000-2009, 2% of all registered fatal crashes in the Netherlands took place at roadworks. In addition, roadworks seem to increase the crash rate. Lorries are relatively often involved in crashes at

  7. 基于微波与磁铁耦合发热效应的融雪除冰技术%Techniques for snow-melting and deiced based on microwave and magnet coupling effect

    Institute of Scientific and Technical Information of China (English)

    郭德栋; 沙爱民

    2012-01-01

    In order to improve the microwave deicing efficiency of cleating the ice on the road rapidly, the deicing tech- nology of asphalt pavement based on microwave and magnet coupling effect was studied by tests. First, the technologi- cal property of magnetite aggregate and magnetite asphalt concrete were tested. Second, the microwave-heated tests were put forth to analyze the heated efficiency of conventional and magnetite aggregates. Finally, the microwave deicing efficiency of asphalt concrete was studied by the laboratory tests. The results showed the technological property of mag- netite asphalt concrete could meet the requirements according to specification. The microwave-heated efficiency of magnetite aggregates was about 20 times of conventional aggregates. The microwave deicing efficiency of magnetite asphalt concrete was about 10-20 times of conventional asphalt concrete.%为提高道路的融雪除冰效率,实现冬季道路雪后快速畅通,对基于微波与磁铁耦合效应的融雪除冰技术进行了试验研究。首先测定了磁铁矿集料的技术性质和磁铁矿沥青混凝土的路用性能;其次通过微波发热试验对比分析了普通集料和含磁铁集料的微波发热效率;最后通过室内除冰试验分析了磁铁矿沥青混凝土的微波除冰效率。结果表明:磁铁矿沥青混凝土路用性能能够满足规范要求;磁铁矿集料的微波发热效率约为普通集料的20倍;磁铁矿沥青混凝土的微波除冰效率约为普通沥青混凝土的10~30倍。

  8. Major Roads

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data set contains roadway centerlines for major roads (interstates and trunk highways) found on the USGS 1:24,000 mapping series. These roadways are current...

  9. GPS Roads

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set contains a 1:100,000 scale vector digital representation of all interstate highways, all US highways, most of the state highways, and some county roads...

  10. New Technologies for de-icing Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Baaaath, Lars; Loefgren, Hans

    2000-11-15

    This is a pilot study to investigate icing on wings of wind power turbines. In this report we present and discuss various ways and means to either heat water droplets or melt ice when formed on the wings of wind turbines. The situation is different from icing on wings of airplanes in that (1) the wings of wind turbines spend all of their time in the atmosphere where the risk of icing is highest and (2) the speed of wing to air varies over the wing where it is constant for an airplane. The form of the wind turbine wings also varies from tip to centre, to compensate for the varying relative air speed. We have concentrated on icing conditions at temperatures -10 deg C - 0 deg C and droplet sizes of 1-10 mum. Icing occurs also at much lower temperatures, but this will probably be because of direct freezing of water vapour to ice. This is presently outside the scope of our pilot project report. We conclude that - The form of the wing, especially on the contact area may be crucial to the icing problem. - Also the nano-metric structure of the wing surface can probably be designed so that the water droplets have a minimized contact area to the wing. Our pilot investigation also suggests the following: - Microwaves are much too inefficient to heat water or melt ice. Direct microwave devices should therefore not be developed. Indirect heating with microwaves is possible. - Millimeter waves are sufficiently efficient, but the generation is most probably too inefficient to be of any practical use. - Infrared waves are very efficient to heat water and melt ice and should be investigated. - Heat conduction is also efficient and should be pursued. Using microwaves to heat the wing surface which then conduct heat to the water/ice is a very efficient and robust method. Our pre-study suggests that the solution to avoid icing or de-ice wings of wind turbines most probably is not one single technology. The form and surface structure of the wings play important role for icing

  11. 电脉冲除冰系统除冰激励的仿真研究%Simulation of Deicing Excitation of Electro-impulse Deicing System

    Institute of Scientific and Technical Information of China (English)

    李清英; 白天; 朱春玲

    2011-01-01

    A two-dimensional electromagnetic eddy current field analysis model of the experimental electro-impulse deicing system was developed.A numerical post-processing method was proposed to simulate the deicing excitation exerting on the testing skin.Moreover,a three-dimensional dynamic analysis model of the testing skin was built based on the dynamic finite element method.The accelerations were calculated by loading the transient pressure to the skin model.Then,the acceleration experiment was introduced to verify the simulation results.It is obtained that the numerical acceleration values agree well with the experimental data,which indicates that it is feasible for the deicing excitation to use the method of post-processing pressure distribution and the method of the dynamic finite elements of the testing skin.The presented methods provide a solid basis for the ice failure analysis of the electro-impulse deicing system.%建立了电脉冲除冰实验系统的二维电磁涡流场分析模型,提出了数值计算后处理求解试验蒙皮表面除冰激励分布的方法,并利用有限元动力分析方法建立了试验蒙皮的三维动力分析模型,通过在模型上加载后处理所得的表面瞬态压力,仿真获得了试验蒙皮的响应加速度,最后引入加速度实验用以验证模拟值。结果表明,基于二维电磁涡流场数值计算后处理求解除冰激励与有限元动力分析试验蒙皮的方法,所得的加速度与实验测量值吻合较好,因此说明了所述方法的正确性,可为电脉冲除冰系统的冰层破坏分析奠定基础。

  12. Evaluation of activated sludge for biodegradation of propylene glycol as an aircraft deicing fluid.

    Science.gov (United States)

    Delorit, Justin D; Racz, LeeAnn

    2014-04-01

    Aircraft deicing fluid used at airport facilities is often collected for treatment or disposal in order to prevent serious ecological threats to nearby surface waters. This study investigated lab scale degradation of propylene glycol, the active ingredient in a common aircraft deicing fluid, by way of a laboratory-scale sequencing batch reactor containing municipal waste water treatment facility activated sludge performing simultaneous organic carbon oxidation and nitrification. The ability of activated sludge to remove propylene glycol was evaluated by studying the biodegradation and sorption characteristics of propylene glycol in an activated sludge medium. The results indicate sorption may play a role in the fate of propylene glycol in AS, and the heterotrophic bacteria readily degrade this compound. Therefore, a field deployable bioreactor may be appropriate for use in flight line applications.

  13. Modeling the kinetics of microbial degradation of deicing chemicals in porous media under flow conditions.

    Science.gov (United States)

    Wehrer, Markus; Jaesche, Philipp; Totsche, Kai Uwe

    2012-09-01

    A quantitative knowledge of the fate of deicing chemicals in the subsurface can be provided by joint analysis of lab experiments with numerical simulation models. In the present study, published experimental data of microbial degradation of the deicing chemical propylene glycol (PG) under flow conditions in soil columns were simulated inversely to receive the parameters of degradation. We evaluated different scenarios of an advection-dispersion model including different terms for degradation, such as zero order, first order and inclusion of a growing and decaying biomass for their ability to explain the data. The general break-through behavior of propylene glycol in soil columns can be simulated well using a coupled model of solute transport and degradation with growth and decay of biomass. The susceptibility of the model to non-unique solutions was investigated using systematical forward and inverse simulations. We found that the model tends to equifinal solutions under certain conditions.

  14. Distributed road assessment system

    Science.gov (United States)

    Beer, N. Reginald; Paglieroni, David W

    2014-03-25

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

  15. [Methodical approaches to the substantiation of hygienic requirements for the application of deicing materials].

    Science.gov (United States)

    Kriatov, I A; Tonkopiĭ, N I; Vodianova, M A; Rusakov, N V; Doner'ian, L G; Evseeva, I S; Ushakov, D I; Matveeva, I S; Vorob'eva, O V; Tsapkova, N N

    2014-01-01

    In the paper there is presented a review of existing guidelines and rules of operation of deicing materials (DIM), as well as opportunities for their processing with the aim to ensure the security for the environment and public health. There are described the ecological- hygienic and toxicological properties of chemicals. There are reported results of a pot experiment for the assessment of the impact of DIM on the lawn.

  16. Louisiana ESI: ROADS (Road Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains the state maintained primary and secondary road network of Louisiana. Vector lines in the data set represent Interstates, U.S. Highways, and...

  17. Radio-frequency-transparent, electrically conductive graphene nanoribbon thin films as deicing heating layers.

    Science.gov (United States)

    Volman, Vladimir; Zhu, Yu; Raji, Abdul-Rahman O; Genorio, Bostjan; Lu, Wei; Xiang, Changsheng; Kittrell, Carter; Tour, James M

    2014-01-08

    Deicing heating layers are frequently used in covers of large radio-frequency (RF) equipment, such as radar, to remove ice that could damage the structures or make them unstable. Typically, the deicers are made using a metal framework and inorganic insulator; commercial resistive heating materials are often nontransparent to RF waves. The preparation of a sub-skin-depth thin film, whose thickness is very small relative to the RF skin (or penetration) depth, is the key to minimizing the RF absorption. The skin depth of typical metals is on the order of a micrometer at the gigahertz frequency range. As a result, it is very difficult for conventional conductive materials (such as metals) to form large-area sub-skin-depth films. In this report, we disclose a new deicing heating layer composite made using graphene nanoribbons (GNRs). We demonstrate that the GNR film is thin enough to permit RF transmission. This metal-free, ultralight, robust, and scalable graphene-based RF-transparent conductive coating could significantly reduce the size and cost of deicing coatings for RF equipment covers. This is important in many aviation and marine applications. This is a demonstration of the efficacy and applicability of GNRs to afford performances unattainable by conventional materials.

  18. Queuing Aircraft Deicing-dispatch in Multi-deicing Bays Based on Non-cooperative Game Theory%多除冰坪排队飞机除冰过程调度非合作博弈

    Institute of Scientific and Technical Information of China (English)

    邢志伟; 唐广群; 任准

    2013-01-01

    According to the practical situation of aircraft delays in hub airports on snowy days and the current application of multi-deicing bays (MDB),aircraft queuing model of the MDB is established based on multi-server queuing system theory.Besides,the dispatch model of each corresponding holding deicing queue is also established based on game theory.The dynamic flights data of Beijing Capital Airport are used for simulation.The results show that the classification and fair allocation of the deicing bay can decrease the holding time of all the deicing aircrafts in the deicing system and relieve the deicing jam in peak hours,and the model guarantees the fairness of the deicing resources allocation and presents the relationship between MDB input and aircraft's sojourn time.This research also provides a new way for airports' deicing operation and deicing bay construction.%针对冰雪天气大型枢纽机场的大面积航班延误及多除冰坪的实际情况,利用多服务台排队系统理论,建立多除冰坪飞机排队模型,并结合博弈思想建立对应于各等待除冰队列的调度模型.利用首都机场动态航班数据进行仿真计算.仿真结果表明,对除冰位进行分类和合理分配,可以降低所有除冰飞机在除冰系统中的总逗留时间,从而缓解高峰时段除冰坪拥堵情况,给出了除冰坪投入量与飞机逗留时间的关系,保证了除冰资源分配的公平性,为机场地面除冰运行及除冰坪建设提供了一种新的思路.

  19. The influence of supraglacial debris cover variability on de-icing processes - examples from Svalbard

    Science.gov (United States)

    Lukas, Sven; Benn, Douglas I.; Boston, Clare M.; Hawkins, Jack; Lehane, Niall E.; Lovell, Harold; Rooke, Michael

    2014-05-01

    Extensive supraglacial debris covers are widespread near the margins of many cold-based and polythermal surging and non-surging glaciers in Svalbard. Despite their importance for current glacier dynamics and a detailed understanding of how they will affect the de-icing of ice-marginal areas, little work has been carried out to shed light on the sedimentary processes operating in these debris covers. We here present data from five different forelands in Svalbard. In all five cases, surfaces within the debris cover can be regarded as stable where debris cover thickness exceeds that of the active layer; vegetation development and absence of buried ice exposures at the surface support this conclusion, although test pits and geophysical investigations have revealed the presence of buried ice at greater depths (> 1-3 m). These findings imply that even seemingly stable surfaces at present will be subject to change by de-icing in the future. Factors and processes that contribute towards a switch from temporarily stable to unstable conditions have been identified as: 1. The proximity to englacial or supraglacial meltwater channels. These channels enlarge due to thermo-erosion, which can lead to the eventual collapse of tunnel roofs and the sudden generation of linear instabilities in the system. Along such channels, ablation is enhanced compared to adjacent debris-covered ice, and continued thermo-erosion continuously exposes new areas of buried ice at the surface. This works in conjunction with 2. Debris flows that occur on all sloping ground and transfer material from stable to less stable (sloping) locations within the debris cover and eventually into supraglacial channels, from where material is then removed from the system. Several generations of debris flows have been identified in all five debris covers, strongly suggesting that these processes are episodic and that the loci of these processes switch. This in turn indicates that transfer of material by debris flows

  20. Frost susceptibility of granular subbase materials contaminated by deicing chemicals

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr; Orlander, Tobias; Doré, Guy

    2013-01-01

    to be caused by ice segregation, but rather a volume increase by fusion caused by a small amount of pore water. The direction of the frost front could not be determined from the collected test results, and no reduction in bearing capacity or increase in frost susceptibility can be derived from the collected...... on roads and airfields enter the granular subbase materials and thereby makes the soil more frost-susceptible. In this project a series of isothermal frost heave tests has been carried out on granular subbase material from the runway at Kuujjuaq Airport, Québec, Canada. The tests have been carried out......, were used in order to determine any influence from the cooling ramp. The tests included settings that allowed the samples additional brine during freezing. Hence, the water and salinity were measured before and after the tests in order to determine the redistribution of water and salinity. The test...

  1. Road works

    CERN Multimedia

    GS Department

    2010-01-01

    From Monday 11 October until Friday 29 October 2010, the flow of traffic will be disrupted by road works at the roundabout in front of Restaurant No. 2; The number of spaces available in the car park in front of Rest. No. 2 will be reduced. Thank you for your understanding during this period. GS/SEM Group

  2. Study on de-icing criterion of electro-impulse de-icing simulation%电脉冲除冰仿真冰层松脱准则研究

    Institute of Scientific and Technical Information of China (English)

    张永杰; 董文俊; 王斌团; 廖凯

    2012-01-01

    电脉冲除冰系统以其结构简单、重量轻、效率高等优良性能,已成为未来飞机除冰系统的主要发展方向之一.开展电脉冲除冰过程的动力学仿真分析与冰层松脱准则研究,能够为飞机电脉冲除冰系统设计提供基本参考依据.在研究比较相关技术文献的基础上,综合考虑了冰层松脱过程中法向正应力与层间剪应力的共同作用,提出了一种改进的冰层松脱准则;数值算例证实该准则合理、准确,能够应用于电脉冲除冰过程的仿真分析中.%The Electro-Impulse De-lcing(EIDI) system, which possesses simple structure, light weight and high efficiency etc. Excellent performances, has been a main development direction of airplane de-icing system in future. For airplane EIDI design, it is an essential reference to simulate electro-impulse de-icing process and study de-icing criterion. In this paper, based on studying and comparing the relational technology literatures, an improved de-icing criterion is proposed. In the criterion, the normal stress and interfacial shear stress are considered during the de-icing process. Numerical experiments show that the criterion is reasonable, accurate and applicable for simulating electro-impulse de-icing process.

  3. 飞机除冰液地面除冰过程模型仿真与实验%Model Simulation and Experiment of Aircraft Deicing Process Using Deicing Fluids on Ground

    Institute of Scientific and Technical Information of China (English)

    陈斌; 王立文

    2012-01-01

    描述了飞机地面除冰过程相关参数和热量损耗关系,选择机翼表面温度和积冰厚度作为描述该过程的状态变量,基于热平衡理论建立了该过程的数学模型。通过仿真研究,得出飞机地面除冰过程除冰效率的变化规律:提高除冰液温度,除冰效率明显提高;如果除冰液温度恒定,一味地增大除冰液流量,除冰效率提高不明显。在飞机地面除冰环境模拟装置上进行了模型验证实验,实验和仿真结果趋势一致,表明所建模型与实际过程匹配,可以为后续飞机地面除冰过程装备参数优化奠定基础。%Several parameters and thermal consumption associated with the deicing process were described,and then the airfoil temperature and the ice thickness on the airfoil were chosen as state parameters to depict the deicing process.The deicing process model was established and simulated based on thermal balance.The simulation results reveal that the deicing efficient is enhanced obviously with a high deicing fluids temperature,but the enhancement degree is small if the deicing fluids flow rate is raised only with the temperature constant.Finally,an experiment was done based on an aircraft deicing simulation equipment.Experiment results are consistent with simulation result,which shows that the model has a good match with practical process.So this model could be as the base for the further research on the aircraft deicing process parameters optimization.

  4. Traffic Accidents on Slippery Roads

    DEFF Research Database (Denmark)

    Fonnesbech, J. K.; Bolet, Lars

    2014-01-01

    Police registrations from 65 accidents on slippery roads in normally Danish winters have been studied. The study showed: • 1 accident per 100 km when using brine spread with nozzles • 2 accidents per 100 km when using pre wetted salt • 3 accidents per 100 km when using kombi spreaders The results...... of accidents in normally Danish winter seasons are remarkable alike the amount of salt used in praxis in the winter 2011/2012. • 2.7 ton NaCl/km when using brine spread with nozzles • 5 ton NaCl/km when using pre wetted salt. • 5.7 ton NaCl/km when using kombi spreaders The explanation is that spreading...

  5. A structural dynamics investigation related to EIDI applications. [Electro-Impulse Deicing

    Science.gov (United States)

    Bernhart, W. D.; Gien, P. H.

    1986-01-01

    A method for modeling the structural dynamics of electro-impulse deicing is presented. A guideline for building a representative finite element model is discussed together with the experimental determination of the force pulse parameters used in the computational model. The results from the computer solution are compared with experimental results for a semi-cylindrical shell. This preliminary comparison indicated that typical structural dynamic responses may be predicted in the near coil field for the duration of the forcing pulse. The sensitivity of the response to both geometric and electrical parameters is also discussed.

  6. Electro-impulse deicing - Structural dynamic studies, icing tunnel tests and applications

    Science.gov (United States)

    Bernhart, W. D.; Zumwalt, G. W.

    1984-01-01

    This paper contains a discussion of the comparison of analytical and experimental results of the dynamic response of a flat rectangular plate subjected to electro-impulse type deicing forces. Early attempts in this correlation have been hampered by the complex leading edge geometries of the airfoils tested to date. The lack of a suitable analytical model for a typical leading edge structure has prompted these preliminary investigations of simple geometries, beginning with a flat plate and to be followed by a semi-cylindrical leading edge representation. The comparisons reported herein are thus limited to rectangular plate models. Project plans and icing tunnel results are given.

  7. Use of natural resources for sustainable roads

    CSIR Research Space (South Africa)

    Paige-Green, P

    2009-01-01

    Full Text Available the surfacing and the formation of blisters, loosening of the upper layer and loss of the seal. Even when the seal is perfectly impermeable, water will usually escape from beneath the surfacing at the edge of the road resulting in deposition of salts...

  8. Synthesis and properties of a clean and sustainable deicing additive for asphalt mixture.

    Science.gov (United States)

    Peng, Chao; Yu, Jianying; Zhao, Zhijie; Dai, Jing; Fu, Jingyi; Zhao, Meiling; Wang, Wei

    2015-01-01

    A clean and sustainable deicing additive was prepared via the adsorption of acetate anions (Ac-) by magnesium (Mg) and aluminum (Al) calcined layered double hydroxide (Mg/Al-CLDH). Fourier transform infrared spectroscopy spectrums proved that Ac- had intercalated into LDH structure. X-ray diffraction patterns, scanning electron microscopy and transmission electron microscopy images showed that the intercalation spacing and platelet thickness of Mg and Al layered double hydroxide containing Ac- anions (Mg/Al-Ac- LDH) had been enlarged due to substitution of divalent CO32- anions by a larger quantity of monovalent Ac- anions. Differential scanning calorimetry tests testified that the insoluble Mg2/Al-Ac- LDH evidently decreased the freeze point (FP) of water to -10.68°C. X-ray photoelectron spectroscopy analyses confirmed that the Ac- were strongly confined by the metal layers of LDHs. FP test of asphalt mixtures confirmed that Mg/Al-Ac- LDHs reduced FP to -5.5°C. Immersion test results indicated that Mg/Al-Ac- LDH had a good deicing durability and Ac- did not released from asphalt mixture. Snow melting observation was conducted further testified that Mg/Al-Ac- LDH melted snow or ice sustainably.

  9. Synthesis and properties of a clean and sustainable deicing additive for asphalt mixture.

    Directory of Open Access Journals (Sweden)

    Chao Peng

    Full Text Available A clean and sustainable deicing additive was prepared via the adsorption of acetate anions (Ac- by magnesium (Mg and aluminum (Al calcined layered double hydroxide (Mg/Al-CLDH. Fourier transform infrared spectroscopy spectrums proved that Ac- had intercalated into LDH structure. X-ray diffraction patterns, scanning electron microscopy and transmission electron microscopy images showed that the intercalation spacing and platelet thickness of Mg and Al layered double hydroxide containing Ac- anions (Mg/Al-Ac- LDH had been enlarged due to substitution of divalent CO32- anions by a larger quantity of monovalent Ac- anions. Differential scanning calorimetry tests testified that the insoluble Mg2/Al-Ac- LDH evidently decreased the freeze point (FP of water to -10.68°C. X-ray photoelectron spectroscopy analyses confirmed that the Ac- were strongly confined by the metal layers of LDHs. FP test of asphalt mixtures confirmed that Mg/Al-Ac- LDHs reduced FP to -5.5°C. Immersion test results indicated that Mg/Al-Ac- LDH had a good deicing durability and Ac- did not released from asphalt mixture. Snow melting observation was conducted further testified that Mg/Al-Ac- LDH melted snow or ice sustainably.

  10. Improved management of winter operations to limit subsurface contamination with degradable deicing chemicals in cold regions.

    Science.gov (United States)

    French, Helen K; van der Zee, Sjoerd E A T M

    2014-01-01

    This paper gives an overview of management considerations required for better control of deicing chemicals in the unsaturated zone at sites with winter maintenance operations in cold regions. Degradable organic deicing chemicals are the main focus. The importance of the heterogeneity of both the infiltration process, due to frozen ground and snow melt including the contact between the melting snow cover and the soil, and unsaturated flow is emphasised. In this paper, the applicability of geophysical methods for characterising soil heterogeneity is considered, aimed at modelling and monitoring changes in contamination. To deal with heterogeneity, a stochastic modelling framework may be appropriate, emphasizing the more robust spatial and temporal moments. Examples of a combination of different field techniques for measuring subsoil properties and monitoring contaminants and integration through transport modelling are provided by the SoilCAM project and previous work. Commonly, the results of flow and contaminant fate modelling are quite detailed and complex and require post-processing before communication and advising stakeholders. The managers' perspectives with respect to monitoring strategies and challenges still unresolved have been analysed with basis in experience with research collaboration with one of the case study sites, Oslo airport, Gardermoen, Norway. Both scientific challenges of monitoring subsoil contaminants in cold regions and the effective interaction between investigators and management are illustrated.

  11. Overview of numerical codes developed for predicted electrothermal deicing of aircraft blades

    Science.gov (United States)

    Keith, Theo G.; De Witt, Kenneth J.; Wright, William B.; Masiulaniec, K. Cyril

    1988-01-01

    An overview of the deicing computer codes that have been developed at the University of Toledo under sponsorship of the NASA-Lewis Research Center is presented. These codes simulate the transient heat conduction and phase change occurring in an electrothermal deicier pad that has an arbitrary accreted ice shape on its surface. The codes are one-dimensional rectangular, two-dimensional rectangular, and two-dimensional with a coordinate transformation to model the true blade geometry. All modifications relating to the thermal physics of the deicing problem that have been incorporated into the codes will be discussed. Recent results of reformulating the codes using different numerical methods to increase program efficiency are described. In particular, this reformulation has enabled a more comprehensive two-dimensional code to run in much less CPU time than the original version. The code predictions are compared with experimental data obtained in the NASA-Lewis Icing Research Tunnel with a UH1H blade fitted with a B. F. Goodrich electrothermal deicer pad. Both continuous and cyclic heater firing cases are considered. The major objective in this comparison is to illustrate which codes give acceptable results in different regions of the airfoil for different heater firing sequences.

  12. VT Road Centerline

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata)(User Guide)The Vermont Road Centerline data layer (TransRoad_RDS) contains all town and state highways, as well as many private roads. The...

  13. TransRoad_RDS

    Data.gov (United States)

    Vermont Center for Geographic Information — The Road Centerline data layer (TransRoad_RDS) contains all town and state highways, as well as many private roads. The centerlines were originally developed under...

  14. Armenia - Rural Road Rehabilitation

    Data.gov (United States)

    Millennium Challenge Corporation — The key research questions guiding our design of the RRRP evaluation are: • Did rehabilitating roads affect the quality of roads? • Did rehabilitating roads improve...

  15. The Influence of Iron Ions on the Aqueous Photocatalytic Oxidation of Deicing Agents

    Directory of Open Access Journals (Sweden)

    D. Klauson

    2007-01-01

    Full Text Available An experimental research into aqueous photocatalytic oxidation (PCO of the deicing compounds, 2-ethoxyethanol (2-EE, diethylene glycol monomethyl ether (DEGMME, and ethylene glycol (EG was undertaken. The addition of iron ions to the acidic aqueous solutions to be treated displayed complex influence on the oxidation efficiency of the above mentioned substances, resulting in a sharp increase of the PCO efficiency at smaller concentrations of iron ions followed by a drastic decrease with the increasing iron ion concentrations. The phenomena observed can be explained by the electron scavenging effect of the iron ions and the competitive adsorption of iron ions and the oxidized substances on titanium dioxide surface. The carbonic acids determined as the PCO by-products allow outlining some reaction pathways for the substances under consideration.

  16. Full two-dimensional transient solutions of electrothermal aircraft blade deicing

    Science.gov (United States)

    Masiulaniec, K. C.; Keith, T. G., Jr.; Dewitt, K. J.; Leffel, K. L.

    1985-01-01

    Two finite difference methods are presented for the analysis of transient, two-dimensional responses of an electrothermal de-icer pad of an aircraft wing or blade with attached variable ice layer thickness. Both models employ a Crank-Nicholson iterative scheme, and use an enthalpy formulation to handle the phase change in the ice layer. The first technique makes use of a 'staircase' approach, fitting the irregular ice boundary with square computational cells. The second technique uses a body fitted coordinate transform, and maps the exact shape of the irregular boundary into a rectangular body, with uniformally square computational cells. The numerical solution takes place in the transformed plane. Initial results accounting for variable ice layer thickness are presented. Details of planned de-icing tests at NASA-Lewis, which will provide empirical verification for the above two methods, are also presented.

  17. Kinetics of anaerobic degradation of glycol-based type I aircraft deicing fluids.

    Science.gov (United States)

    Schoenberg, T; Veltman, S; Switzenbaum, M

    2001-01-01

    The kinetics of anaerobic degradation of glycol-based Type I aircraft deicing fluids (ADFs) were characterized using suspended-growth fill-and-draw reactors. Both Type I ADFs tested showed near-complete anaerobic degradability. First-order degradation rate constants of 3.5 d(-1) for the propylene glycol-based Type I ADF and 5.2 d(-1) for the ethylene glycol-based Type I ADF were obtained through continuous-culture means under mesophilic conditions (35 degrees C). Fill-and-draw operation at lower temperatures affected anaerobic degradability only minimally down to 25 degrees C but substantially below 25 degrees C. High Type I ADF feed concentrations substantially affected degradability. Batch testing of fill-and-draw reactors resulted in first-order degradation rate constants of 1.9 d(-1) for propylene glycol-based Type I ADF and 3.5 d(-1) for ethylene glycol-based Type I ADF.

  18. Composites of Graphene Nanoribbon Stacks and Epoxy for Joule Heating and Deicing of Surfaces.

    Science.gov (United States)

    Raji, Abdul-Rahman O; Varadhachary, Tanvi; Nan, Kewang; Wang, Tuo; Lin, Jian; Ji, Yongsung; Genorio, Bostjan; Zhu, Yu; Kittrell, Carter; Tour, James M

    2016-02-10

    A conductive composite of graphene nanoribbon (GNR) stacks and epoxy is fabricated. The epoxy is filled with the GNR stacks, which serve as a conductive additive. The GNR stacks are on average 30 nm thick, 250 nm wide, and 30 μm long. The GNR-filled epoxy composite exhibits a conductivity >100 S/m at 5 wt % GNR content. This permits application of the GNR-epoxy composite for deicing of surfaces through Joule (voltage-induced) heating generated by the voltage across the composite. A power density of 0.5 W/cm(2) was delivered to remove ∼1 cm-thick (14 g) monolith of ice from a static helicopter rotor blade surface in a -20 °C environment.

  19. The road safety audit and road safety inspection.

    NARCIS (Netherlands)

    2007-01-01

    A road safety audit (RSA) and a road safety inspection (RSI) are used to test the safety level of the road infrastructure. The RSA tests the design of new roads or the reconstruction of existing roads, whereas the RSI is used for testing existing roads. An RSA, therefore, aims to 'improve' the road

  20. The road safety audit and road safety inspection.

    NARCIS (Netherlands)

    2007-01-01

    A road safety audit (RSA) and a road safety inspection (RSI) are used to test the safety level of the road infrastructure. The RSA tests the design of new roads or the reconstruction of existing roads, whereas the RSI is used for testing existing roads. An RSA, therefore, aims to 'improve' the road

  1. Kinetics of microbial degradation of deicing chemicals in percolated porous media - the modeling perspective

    Science.gov (United States)

    Wehrer, Markus; Lissner, Heidi; Totsche, Kai

    2013-04-01

    A quantitative knowledge of the fate of deicing chemicals in the subsurface can be provided by analysis of laboratory and field experiments with numerical simulation models. In the present study, experimental data of microbial degradation of the deicing chemical propylene glycol (PG) under flow conditions in soil columns and field lysimeters were simulated to analyze the process conditions of degradation and to obtain the according parameters. Results from the column experiment were evaluated applying different scenarios of an advection-dispersion model using HYDRUS-1D. To reconstruct the data, different competing degradation models were included, i.e., zero order, first order and inclusion of a growing and decaying biomass. The general breakthrough behavior of propylene glycol in soil columns can be simulated well using a coupled model of solute transport and degradation with growth and decay of biomass. The susceptibility of the model to non-unique solutions was investigated using systematical forward and inverse simulations. We found that the model tends to equifinal solutions under certain conditions. Complex experimental boundary conditions can help to avoid this. Under field conditions, the situation is far more complex than in the laboratory. Studying the fate of PG with undisturbed lysimeters we found that aerobic and anaerobic degradation occurs simultaneously. We attribute this to the physical structure and the aggregated nature of the undisturbed soil material . This results in the presence of spatially disjoint oxidative and reductive regions of microbial activity and requires, but is not fully reflected by a dual porosity model. Currently, the numerical simulation of this system is in progress, considering several flow and transport models. A stochastic global search algorithm (DREAM-ZS) is used in conjuction with HYDRUS-1D to avoid local minima in the inverse simulations. The study shows the current limitations and potentials of modeling degradation

  2. Deicing of medium voltage power transmission lines by Joule heating method

    Energy Technology Data Exchange (ETDEWEB)

    Farokhi, S.; Vahidi, B. [Amirkabir Univ. of Technology, Tehran (Iran, Islamic Republic of). Electrical Engineering Dept.

    2005-07-01

    A Joule heating method for the de-icing of overhead transmission lines was presented. The combined use of short circuits and reduced voltage was introduced as as effective method for the de-icing of sub-transmission lines of a utility in Iran. The method is able to melt ice in a short period of time. The required electrical current and the time needed for melting the ice as a function of wind speed, air temperature and ice thickness was determined by using a finite difference heat transfer model which considered the heat flux terms. An algorithm of the application method was proposed using the finite difference heat transfer model and considering steady state radial heat conduction. The required time for melting the accumulated ice on overhead transmission lines for different values of line current and climatic conditions was calculated. In the proposed method, after disconnecting the end of the line, a 3 phase short circuit was applied and accumulated ice was melted because of Joule losses. The main restrictions to the method were the current rating of facilities, and source capacity. After a consideration of these restrictions, instead of feeding the line by rated voltage, a voltage with a value of about 20 to 40 per cent of its rated voltage was applied and a short circuit on the end of the line should be made. The algorithm was made by collecting the data for the power system, disconnecting both ends of the line from the system and applying required changes on loads. transformers calculated from the load flow of the system. The line was fed with the reduced voltage by connecting the line to a lower level voltage. A case study of the method was presented. 10 refs., 1 tab., 4 figs.

  3. The Dynamics of Growing Herbaceous Plants in the Soil Contaminated with Sodium Formiate

    Directory of Open Access Journals (Sweden)

    Agnė Kazlauskienė

    2011-02-01

    Full Text Available Salts are most frequently used for road maintenance in cold seasons in Lithuania. In case the use of salts is mandatory, the proposal is to apply as small amounts as possible following the norms of use. Using alternative de-icing salts and agents, such as formiates is recommended. Formiates can be applied with the aim to reduce road sliperness and as a preventive measure of de-icing road paving. These substances are efficient, environment-friendly and have no corrosive effect. The article presents physicochemical and toxicological characteristics of the above introduced materials.Article in Lithuanian

  4. Lewis icing research tunnel test of the aerodynamic effects of aircraft ground deicing/anti-icing fluids

    Science.gov (United States)

    Runyan, L. James; Zierten, Thomas A.; Hill, Eugene G.; Addy, Harold E., Jr.

    1992-01-01

    A wind tunnel investigation of the effect of aircraft ground deicing/anti-icing fluids on the aerodynamic characteristics of a Boeing 737-200ADV airplane was conducted. The test was carried out in the NASA Lewis Icing Research Tunnel. Fluids tested include a Newtonian deicing fluid, three non-Newtonian anti-icing fluids commercially available during or before 1988, and eight new experimental non-Newtonian fluids developed by four fluid manufacturers. The results show that fluids remain on the wind after liftoff and cause a measurable lift loss and drag increase. These effects are dependent on the high-lift configuration and on the temperature. For a configuration with a high-lift leading-edge device, the fluid effect is largest at the maximum lift condition. The fluid aerodynamic effects are related to the magnitude of the fluid surface roughness, particularly in the first 30 percent chord. The experimental fluids show a significant reduction in aerodynamic effects.

  5. 飞机除冰液稳定性研究%Study on stability test of aircraft deicing fluids

    Institute of Scientific and Technical Information of China (English)

    彭华乔; 王强; 曾萍; 吴海涛; 张亚博; 张帆; 赵芯; 苏正良; 夏祖西

    2015-01-01

    在SAE AMS 1424和SAE AMS 1428的基础上,分析了I型、II型、III型和IV型飞机除冰液稳定性试验要求和步骤。建议我国积极开展飞机除冰液稳定性检测和研究工作,为除冰液的适航审定提供技术支持。%Based on SAE AMS 1424 and SAE AMS 1428 ,the requirements and procedures of stability test for aircraft deicing fluids type I,II,III and IV are introduced. In order to provide the technical support for deicing fluids airworthiness certification,the corresponding test and research shall be improved.

  6. Efficient on-site degradation of high concentration of spent deicing fluids: A laboratory study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Strong, J.M. [Oak Ridge National Lab., TN (United States); Waltz, M. [REMTECH, Bridgeville, PA (United States)

    1997-10-01

    The on-site treatment of antifreeze compounds and aircraft deicing fluids (ethylene glycol and propylene glycol) will reduce disposal costs, decrease environmental impact, minimize the potential for additional spills/contamination and meet the goals of pollution prevention by reducing the amount of hazardous materials generated. The authors have identified bacteria that can degrade 1-10% glycol waste at room temperatures of ca. 23C. A second subculture was isolated that could degrade glycol waste at ca. 4C.

  7. 机场使用除冰液的应急监测%Airport De-icing Fluid Emergency Monitoring

    Institute of Scientific and Technical Information of China (English)

    胡雄星; 韩中豪

    2012-01-01

    The paper introduced the emergency monitoring for airport de-icing fluid contamination in Shanghai, China The study included development of monitoring program, monitoring sites, analysis project, tracking monitoring, data analysis, etc. The results showed that de-icing waste liquid directly discharging into rivers had polluted water environment seriously in the short term, but the water would gradually return to normal over time. The environmental impact assessment of airport de-icing fluid contamination could be conducted by monitoring the chemical oxygen demand for water.%介绍了机场除冰液污染的应急监测,包括监测方案制订、监测点位设置、分析对象确定、跟踪监测、数据分析等.监测结果表明,除冰液废液直排入河道在短期内对水环境造成了严重影响,但随着时间推移水体逐步恢复正常.机场除冰液污染的应急监测可通过监测水体中的化学需氧量进行.

  8. Electrical resistivity tomography as monitoring tool for unsaturated zone transport: an example of preferential transport of deicing chemicals.

    Science.gov (United States)

    Wehrer, Markus; Lissner, Heidi; Bloem, Esther; French, Helen; Totsche, Kai Uwe

    2014-01-01

    Non-invasive spatially resolved monitoring techniques may hold the key to observe heterogeneous flow and transport behavior of contaminants in soils. In this study, time-lapse electrical resistivity tomography (ERT) was employed during an infiltration experiment with deicing chemical in a small field lysimeter. Deicing chemicals like potassium formate, which frequently impact soils on airport sites, were infiltrated during snow melt. Chemical composition of seepage water and the electrical response was recorded over the spring period 2010. Time-lapse electrical resistivity tomographs are able to show the infiltration of the melt water loaded with ionic constituents of deicing chemicals and their degradation product hydrogen carbonate. The tomographs indicate early breakthrough behavior in parts of the profile. Groundtruthing with pore fluid conductivity and water content variations shows disagreement between expected and observed bulk conductivity. This was attributed to the different sampling volume of traditional methods and ERT due to a considerable fraction of immobile water in the soil. The results show that ERT can be used as a soil monitoring tool on airport sites if assisted by common soil monitoring techniques.

  9. Deicing salt scaling resistance of concrete incorporating fly ash and (or) silica fume: laboratory and field sidewalk test data

    Energy Technology Data Exchange (ETDEWEB)

    Bouzoubaa, N.; Bilodeau, A.; Fournier, B.; Hooton, R.D.; Gagne, R.; Jolin, M.

    2011-04-15

    A study was carried out in the spring of 2002 on sidewalk sections cast with different concrete mixtures showing the severity of the ASTM C 672 procedure and the adequateness of the BNQ (Bureau de normalisation du Quebec)procedure. This study set out to confirm these results and determine the impact of time of casting on the scaling resistance of the concrete. The results confirmed the adequateness of the BNQ procedure, showing that concrete cast in the fall season scaled more than those cast in the spring. Curing compounds increase the scaling resistance. This study provided results which could be useful when planning to cast sidewalk sections.

  10. Roads (Johnson City)

    Data.gov (United States)

    National Park Service, Department of the Interior — This is a vector line file showing the location of existing NPS roads including access roads for which the park has an easement at Lyndon B. Johnson National...

  11. Roads Near Streams

    Data.gov (United States)

    U.S. Environmental Protection Agency — Roads are a source of auto related pollutants (e.g. gasoline, oil and other engine fluids). When roads are near streams, rain can wash these pollutants directly into...

  12. Future Roads Near Streams

    Data.gov (United States)

    U.S. Environmental Protection Agency — Roads are a source of auto related pollutants (e.g. gasoline, oil and other engine fluids). When roads are near streams, rain can wash these pollutants directly into...

  13. VT Road Centerline

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata)(User Guide)(Symbology layer files: aotclass_only.lyr aotclass_surfacetyp.lyr)The Vermont Road Centerline data layer (TransRoad_RDS) contains all...

  14. Future Road Density

    Data.gov (United States)

    U.S. Environmental Protection Agency — Road density is generally highly correlated with amount of developed land cover. High road densities usually indicate high levels of ecological disturbance. More...

  15. Rural road maintenance management

    OpenAIRE

    Johannessen, B.

    1999-01-01

    This manual summarizes relevant Cambodian government policies regarding rural road maintenance. Chapter 2 defines the various components of road maintenance and describes an effective strategy and organization which addresses the maintenance requirements of rural roads in Cambodia. Chapter 3 is a brief description of the planning, implementation and reporting cycle required in an effective road maintenance management system. Chapter 4 summarizes the contracts management procedures, and finall...

  16. Research Status of Wind Turbine Blade Deicing Technology%风力机叶片防除冰技术研究现状

    Institute of Scientific and Technical Information of China (English)

    汪根胜; 石阳春; 蒋立波; 刘亮

    2016-01-01

    提出了风力机防除冰的关键部件是叶片,并介绍了风力机叶片覆冰的影响,叶片防冰的主动与被动型方法及其各自的优缺点。重点阐述了憎水涂料防冰法的研究现状,并总结了憎水性涂料防冰的三大主要效果。对目前风力机叶片防除冰技术的主流方法进行了综合评价,并指出了其日后的发展方向。%This paper put forward that the key components of wind turbine deicing was the blade, and introduced the effect of ice covering of the blade, the active and passive methods for wind turbine blade deicing together with their merits and defects. The review focused on the research status of hydrophobic deicing coating method, and summarized three main effects of the hydrophobic deicing coating. Finally, a comprehensive evaluation of the current mainstream method of wind turbine blade deicing technology was conducted, and its future development direction was pointed out.

  17. Brief survey of deicing/anti-icing fluid and techniques for aircraft%飞机除冰/防冰液及除冰技术

    Institute of Scientific and Technical Information of China (English)

    李斌

    2012-01-01

    本文主要介绍了飞机除冰/防冰液的四种类型及主要技术要求,包括材料组成与理化性能、稳定性、使用性能、对飞机材料及机场跑道材料的影响、对生态环境的影响等,并简述了飞机液体防冰技术、机械除冰技术和热力防冰技术等几大类除冰技术的发展情况。%The four types and chief requirements of deicing/anti-icing fluid for aircraft were intrduced,including fluid composition and physical properties,stability,performance properties,effect on aircraft materials and runway concrete scaling resistance,environmental information,etc.The development of deicing techniques for aircraft which include fluid deicing,mechanical deicing and hot deicing were summarized.

  18. 架空输电线路除冰技术分析%Analysis of Deicing Methods for Overhead Transmission Lines

    Institute of Scientific and Technical Information of China (English)

    刘顺新; 罗浩东; 邓小磊

    2011-01-01

    At present, how to melt the ice on transmission lines to reduce the losses is still a worldwide technical problem. The existing deicing methods can be divided into three kinds, i.e. the ice-melting method, the mechanical deicing method, and the deicing method with new technology. In this study, a simple transmission line model was established, and the deicing methods mentioned above with their implementation circuits were analyzed respectively. Their advantages and disadvantages were compared.Thus, the most suitable deicing method for the transmission line model was obtained.%如何对覆冰输电线路进行融冰、除冰以降低冰灾损失,目前仍是世界性的技术难题.针对该问题,笔者在现有除冰技术如热力除冰法、机械除冰法以及其它新技术除冰法的基础上,建立了一个简单的输电线路模型,并依次研究各种除冰技术及其实现电路.最后得出适合该输电线路的除冰措施,从而为输电线路在覆冰情况下的除冰提供技术指导.

  19. Monitoring the fate and transport of deicing chemicals in lysimeter experiments

    Science.gov (United States)

    Lißner, H.; Wehrer, M.; Totsche, K. U.

    2012-04-01

    Large amounts of the deicing chemicals (DIC) propylene glycol (PG) and formate are spread for removal of snow and ice on the aircrafts and airfields every winter. A considerable amount of these chemicals are carried into surrounding areas, where they mix with snow and infiltrate in the soil during snowmelt. Even though DIC are easily degradable, the high mobility and the high biological oxygen demand of PG in particular can influence the hydrogeochemistry of the unsaturated and saturated zone. The aims of the study were to evaluate and quantify transport of deicing chemicals during snowmelt under field conditions, and to study effects of DIC degradation on the hydrogeochemistry of the unsaturated zone. Eight undisturbed soil cores (0.3 m x 1 m, 0.071 m3) were retrieved at the Gardermoen Airport, Norway, and installed as non-weighable small scale lysimeters at a nearby field site. Before snowmelt in March 2010, a mix of snow containing 350 g/m2 PG, 71 g/m2 formate, and 17 g/m2 of bromide were added to the lysimeters. To determine the fate and transport of PG we monitored PG and its metabolites, bromide, manganese, and iron in the seepage water. High cumulative infiltration and marginal degradation of PG during the snowmelt period allowed up to 50 % of the PG to leave the upper, microbially most active, region of the soil. Only marginal concentrations of formate were analysed in all lysimeters, indicating fast degradation and favoured metabolism by soil bacteria compared to PG. Low contents of metabolites and the concurrent breakthrough of PG and Br in the seepage water even imply that PG was not significantly degraded before June. Redox values down to 200 mV in April, the detection of propionate and manganese, as well as a rise in pH, suggest partially anearobic localities in the soil, not only during high soil water saturation in April and May but also during summer when PG degradation was very efficient. In the longterm, the intense depletion of electron acceptors

  20. Phosphate salts

    Science.gov (United States)

    ... levels that are too high, and for preventing kidney stones. They are also taken for treating osteomalacia (often ... But intravenous phosphate salts should not be used. Kidney stones (nephrolithiasis). Taking potassium phosphate by mouth might help ...

  1. Salt cookbook

    CERN Document Server

    Saha, Anirban

    2015-01-01

    If you are a professional associated with system and infrastructure management, looking at automated infrastructure and deployments, then this book is for you. No prior experience of Salt is required.

  2. FEATURES ROAD SAFETY AUDIT

    Directory of Open Access Journals (Sweden)

    L. Abramova

    2015-07-01

    Full Text Available Development of the road network, increasing motorization of the population significantly increase the risk of accidents. Experts in the field of traffic are developing methods to reduce the probability of accidents. The ways of solving the problems of road safety audit at various stages of the «life» of roads are considered.

  3. Overload road damage model

    CSIR Research Space (South Africa)

    Roux, MP

    2005-03-01

    Full Text Available Not only do overloaded vehicles pose an increased safety risk on the road (reduced stability and braking efficiency etc.), but they also accelerate the rate of deterioration of the road network and increase road maintenance costs, which in turn...

  4. Anaerobic digestion of aircraft deicing fluid wastes: interactions and toxicity of corrosion inhibitors and surfactants.

    Science.gov (United States)

    Gruden, Cyndee L; Hernandez, Mark

    2002-01-01

    Corrosion inhibitors and surfactants are present in aircraft deicing fluids (ADFs) at significant concentrations (> 1% w/w). The purpose of this research was to study the interactions of a common nonionic surfactant with the commercially significant corrosion inhibitors used in modern ADF (4- and 5-methylbenzotriazole [MeBT]), and to determine the effects of their mixture on the conventional anaerobic digestion process. In mesophilic anaerobic microcosms codigesting wastewater solids, propylene glycol, and MeBT, increasing surfactant levels resulted in enhanced MeBT sorption on digester solids. As judged by anaerobic toxicity assays, responses from digesters containing surfactant concentrations below their critical micelle concentration (CMC) suggested that low nonionic surfactant concentrations could facilitate a reduction in the apparent toxicity of MeBT. In microcosms exposed to surfactant concentrations above their CMC, no increase in MeBT solubility was observed, and the anaerobic toxicity response corresponded to control systems not containing surfactant. Direct microscopic measurements of digesting biomass using fluorescent phylogenetic probes (fluorescent in situ hybridization) revealed that members of the domain Bacteria were more sensitive to MeBT in the presence of surfactant than were members of the domain Archaea.

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

    Science.gov (United States)

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

    2016-04-01

    Road ice is a dangerous meteorological hazard to a nation's transportation system and economy. By reducing the pavement friction with vehicle tyres, ice formation on pavements increases accident risk and delays travelling times thus posing a serious threat to road users' safety and the running of economic activities. Keeping roads clear and open is therefore essential, especially in mountainous areas where ice is likely to form during the winter period. Winter road maintenance helps to restore road efficiency and security, and its benefits are up to 8 times the costs sustained for anti-icing strategies [1]. However, the optimization of maintenance costs and the reduction of the environmental damage from over-salting demand further improvements. These can be achieved by reliable road weather forecasts, and in particular by the prediction of road surface temperatures (RSTs). RST is one of the most important parameters in determining road surface conditions. It is well known from literature that ice forms on pavements in high-humidity conditions when RSTs are below 0°C. We have therefore implemented an automatic forecast system to predict critical RSTs on a test route along the Adige Valley complex terrain, in the Italian Alps. The system considers two physical models, each computing heat and energy fluxes between the road and the atmosphere. One is Reuter's radiative cooling model, which predicts RSTs at sunrise as a function of surface temperatures at sunset and the time passed since then [2]. One is METRo (Model of the Environment and Temperature of Roads), a road weather forecast software which also considers heat conduction through road material [3]. We have applied the forecast system to a network of road weather stations (road weather information system, RWIS) installed on the test route [4]. Road and atmospheric observations from RWIS have been used as initial conditions for both METRo and Reuter's model. In METRo observations have also been coupled to

  6. Road Transport Entrepreneurs and Road Transportation Revolution ...

    African Journals Online (AJOL)

    Toshiba

    An International Multidisciplinary Journal, Ethiopia. Vol. 7 (4), Serial No. ... Nnewi Igbo emerged as pioneer road transport entrepreneurs and charted this novel ..... the cardinal motives for venturing into the transport industry. (Maduewesi ...

  7. Swedish experiences of wind power in cold climate - icing, ice throw and deicing; Svenska erfarenheter av vindkraft i kallt klimat - nedisning, iskast och avisning

    Energy Technology Data Exchange (ETDEWEB)

    Ronsten, Goeran [Aeronautical Research Inst. of Sweden, Bromma (Sweden)

    2004-06-01

    The report treats icing, risk for ice throws and deicing. Statistics over icing exists, but needs to be processed in order to fit the wind energy sector. Preliminary icing maps and operation statistics indicate where icing occurs. The local variations can be important. Measurements of icing in high masts should be started in order to verify and improve existing forecast methods, which in turn can form the base for icing frequency maps. On the basis of reliable frequency maps, siting of wind power plants and the need of deicing equipment can be assessed in a more reliable way than today. Risk areas for ice throws, based on results from EU:s research programmes, is presented. The risk to meet flying ice is small but real, why precautionary measures to avoid accidents should be taken. Today there exists no commercial deicing system for deicing during operation. The Bonus Company announces that such a systems will be ready for delivery in 2005. Enercon markets a light deicing system for stalled plants. Enercon has announced a future, more effective, deicing equipment that can deice during operation. The the first Swedish wind power plants in cold climate ware taken into operation in October 1998. One of these units is a Bonus 600 kW Mk IV standing on a ridge between two of the three Suorva dams. Three units from different manufacturers (Bonus, NEG-Micon and Nordex/Vestas) are installed on Rodovaalen since the autumn 1998. The owner intends to test deicing equipment at this site. Between October 1998 and January 2004 the turbine heating system on the Bonus plant at Suorva has consumed 70 MWh of 8548 MWh (0.82%) while the Rodovaalen plants had used 142 MWh of 6230 MWh (2.3%). Our general knowledge of icing is small since continuous icing measurements not have taken place since the measurements in high masts was completed in the 1980s. Today's ice detectors function well but are considered too costly to be used at the large numbers of places that would be required in

  8. Automatic Road Centerline Extraction from Imagery Using Road GPS Data

    Directory of Open Access Journals (Sweden)

    Chuqing Cao

    2014-09-01

    Full Text Available Road centerline extraction from imagery constitutes a key element in numerous geospatial applications, which has been addressed through a variety of approaches. However, most of the existing methods are not capable of dealing with challenges such as different road shapes, complex scenes, and variable resolutions. This paper presents a novel method for road centerline extraction from imagery in a fully automatic approach that addresses the aforementioned challenges by exploiting road GPS data. The proposed method combines road color feature with road GPS data to detect road centerline seed points. After global alignment of road GPS data, a novel road centerline extraction algorithm is developed to extract each individual road centerline in local regions. Through road connection, road centerline network is generated as the final output. Extensive experiments demonstrate that our proposed method can rapidly and accurately extract road centerline from remotely sensed imagery.

  9. Bicycle facilities on road segments and intersections of distributor roads.

    NARCIS (Netherlands)

    2008-01-01

    A sustainably safe road environment requires bicycle facilities that separate motorized traffic from relatively vulnerable road users like cyclists. Research indicates that on distributor roads the road sections with adjoining or separate bicycle tracks are safer than the road sections without any b

  10. Bicycle facilities on road segments and intersections of distributor roads.

    NARCIS (Netherlands)

    2008-01-01

    A sustainably safe road environment requires bicycle facilities that separate motorized traffic from relatively vulnerable road users like cyclists. Research indicates that on distributor roads the road sections with adjoining or separate bicycle tracks are safer than the road sections without any b

  11. 输电线路新型电磁防除冰%New Electromagnetic Deicing Technology for Transmission Lines

    Institute of Scientific and Technical Information of China (English)

    王新掌; 李红磊; 高建良; 王君莉; 郝少帅

    2015-01-01

    As the deicing of the high voltage transmission line needs outrage of the line and requires large quantities of man power and materials,and is both dangerous and risky, this paper proposes a non-outrage deicing method. Based on the high frequency electromagnetic induction technology and heat conduction theory,the paper establishes the deicing phy-sical model of transmission lines,and uses APDL,the ANSYS parametric programming language to program relative analysis programs, and analyzes the magnetic field and temperature field coupling phenomenon in the numerical method. Contras-ting the temperature distribution and change under different electromagnetic parameters of transmission lines, the paper obtains the main electromagnetic parameters affecting tempera-ture variation of the transmission line,such as the frequency of high frequency current, high frequency current density, the distance between two induction coils,the length of induction coils,the thickness of induction coils and the time of induction heating. On the basis of these main electromagnetic parameters, the coil size is optimized and designed so that the transmission line can efficiently deice above 0℃.%针对当前国内外高压输电线路除冰时需要线路停运,且需要较多的人力、物力、劳动强度大和危险等特点,提出了一种不停电电磁防除冰方法。基于高频电磁感应技术和热传导理论,建立了高压输电线路的防除冰物理模型,利用ANSYS参数化语言APDL进行编程,对输电线路物理模型中的电磁-热现象进行了耦合数值计算。通过对比不同电磁参数下输电线路温度的分布和变化情况,找到了影响输电线路温度变化的主要电磁参数,包括高频电流的频率、高频电流密度、感应线圈间距、感应线圈长度、感应线圈厚度和感应加热时间。据此对线圈尺寸进行了优化设计,使输电线路温度在0℃以上能够有效防除冰。

  12. Degradation of deicing chemicals affects the natural redox system in airfield soils.

    Science.gov (United States)

    Lissner, Heidi; Wehrer, Markus; Jartun, Morten; Totsche, Kai Uwe

    2014-01-01

    During winter operations at airports, large amounts of organic deicing chemicals (DIC) accumulate beside the runways and infiltrate into the soil during spring. To study the transport and degradation of DIC in the unsaturated zone, eight undisturbed soil cores were retrieved at Oslo airport, Norway, and installed as lysimeters at a nearby field site. Before snowmelt in 2010 and 2011, snow amended with a mix of the DICs propylene glycol (PG) and formate as well as bromide as conservative tracer was applied. Water samples were collected and analyzed until summer 2012. Water flow and solute transport varied considerably among the lysimeters but also temporally between 2010 and 2011. High infiltration rates during snowmelt resulted in the discharge of up to 51 and 82% PG in 2010 and 2011, respectively. The discharge of formate remained comparatively low, indicating its favored degradation even at freezing temperatures compared with PG. Manganese (Mn) and iron (Fe) were observed in the drainage in autumn owing to the anaerobic degradation of residual PG during summer. Our findings suggest that upper boundary conditions, i.e., snow cover and infiltration rate, and the extent of preferential flowpaths, control water flow and solute transport of bromide and PG during snowmelt. PG may therefore locally reach deeper soil regions where it may pose a risk for groundwater. In the long term, the use of DIC furthermore causes the depletion of potential electron acceptors and the transport of considerable amounts of Fe and Mn. To avoid an overload of the unsaturated zone with DIC and to maintain the natural redox system, the development of suitable remediation techniques is required.

  13. Roads In and Surrounding Cedar Breaks National Monument, Utah (roads)

    Data.gov (United States)

    National Park Service, Department of the Interior — This coverage contains those transportation routes from the Dixie's d2_travel_rte coverage that were calculated road = 'Road'. The Dixie National Forest Road...

  14. 环保多功能沥青除冰路面一体化设计研究%Environment-friendly multi-function asphalt pavement de-icing design and mechanism

    Institute of Scientific and Technical Information of China (English)

    丁庆军; 彭馨彦; 姜友生; 陈光新; 毛明

    2012-01-01

    依托湖北杭瑞高速公路工程,为降低沿线行车通过居民区带来的噪音污染,解决冬季路面积雪薄冰带来的行车安全问题,以具有一定结构除冰性能的高连通孔隙沥青路面材料为基体,选用橡胶高黏度改性沥青,并掺人环保型化学抑冰剂,开发设计具有除冰、降噪、抗滑功能材料路面.以不牺牲路用性能为前提,通过测试动稳定度、冻融劈裂强度比、飞散损失、抗剪强度等,确定环保型化学抑冰剂的掺量.同时利用驻波管法、手工铺砂法及轮版法测定空隙化分别为16%、20%、24%、28%的路面材料除冰性能、降噪性能和抗滑性能.测试结果表明,当环保型融雪除冰剂的掺量为2%,空隙率控制在20%左右时,高连通孔隙沥青材料的路面使用性能最佳,具有较好的除冰性能、降噪性能和抗滑性能.%The present study aims to introduce a new approach to reducing expressway noise pollution caused by the roadside traffic and relieving the traffic hazard caused by the snow-ice sliding in winter days by taking the Hangzhou-Ruili Expressway construction project as our case study. In proceeding with our research, we have done a series of experiments and tests for our goals by using high-sticking porous asphalt pavement material to lower the traffic noise by using modified high-viscosity rubber asphalt and environment-friendly organic-inorganic composite deicer to increase the skidding and sliding resistance so as to heighten the de-icing function of the road. In our experiments, we have repeatedly tested the dynamic stability, the freeze-thaw splitting strength ratio, the loss of sliding, shear strength and other parameters concerned so as to determine the appropriate dosage of environment-friendly organic-inorganic composite deicer. And, the eventually, the testing results prove that the pavement performance of the innovated composite pavement asphalt material can reduce the skidding and

  15. Trajectory of a road vehicle during road maintenance

    Directory of Open Access Journals (Sweden)

    Stachová Darina

    2017-01-01

    Full Text Available Consider a vehicle moving on a road whose usage over time creates an uneven surface on the road. Road unevenness that we encounter on surface communications often arises as a consequence of dynamical effects of moving vehicles, of weather changes, and due to road construction works. This article concerns with mathematical modeling of the trajectory of a road vehicle moving on such a surface during the course of road maintenance.

  16. Roads to Safety.

    Science.gov (United States)

    Hauer, Ezra

    1991-01-01

    Contends that the level of safety built into roads is largely unpremeditated and that roads and highways are not as safe as they might be. Discusses practices, standards, and deficiencies in highway and traffic safety related to geometric design and traffic engineering. Recommends increased transportation engineering professionalism and public…

  17. Vehicular road influence areas

    Science.gov (United States)

    Huertas, María E.; Huertas, José I.; Valencia, Alexander

    2017-02-01

    Vehicle operation over paved and unpaved roads is an emission source that significantly contributes to air pollution. Emissions are derived from vehicle exhaust pipes and re-suspension of particulate matter generated by wind erosion and tire to road surface interactions. Environmental authorities require a methodology to evaluate road impact areas, which enable managers to initiate counter-measures, particularly under circumstances where historic meteorological and/or air quality data is unavailable. The present study describes an analytical and experimental work developed to establish a simplified methodology to estimate the area influenced by vehicular roads. AERMOD was chosen to model pollutant dispersion generated by two roads of common attributes (straight road over flat terrain) under the effects of several arbitrary chosen weather conditions. The resulting pollutant concentration vs. Distance curves collapsed into a single curve when concentration and distance were expressed as dimensionless numbers and this curve can be described by a beta distribution function. This result implied that average concentration at a given distance was proportional to emission intensity and that it showed minor sensitivity to meteorological conditions. Therefore, road influence was defined by the area adjacent to the road limited by distance at which the beta distribution function equaled the limiting value specified by the national air quality standard for the pollutant under consideration.

  18. Road crash costs.

    NARCIS (Netherlands)

    2010-01-01

    Road crashes result in all kinds of social costs, such as medical costs, production loss, human losses, property damage, settlement costs and costs due to congestion. Studies into road crash costs and their trends are carried out quite regularly. In 2009, the costs amounted to € 12.5 billion, or 2.2

  19. 飞机除冰液在冰中的渗透性能影响因素分析%Research Aircraft Deicing Fluid Permeability of Ice

    Institute of Scientific and Technical Information of China (English)

    陈元; 李志强; 张帆; 彭华乔; 于新华

    2015-01-01

    In order to improve the ability of aircraft deicing fluid airworthiness certification, making a research and analysis of aircraft deicing fluid influence on the permeability of ice through temperature, freezing point, osmotic pressure and the molecular weight respectively, according to《AIR 6211 Ice Penetration Test Method for Runways and Taxiways Deicing/Anti-icing Chemicals》. The results show that the depth of aircraft deicing fluid on the penetration of ice decreases as the temperature is reduced. The permeability of Newtonian-fluid is better than non Newtonian-fluid at the same temperature. The permeability of aircraft deicing fluid has no direct relation to the freezing point and associated with osmotic pressure. Moreover, the higher pressure, the better permeability of ice.%为了提高飞机除冰液适航验证能力,根据《AIR 6211 Ice Penetration Test Method for Runways and Taxiways Dei-cing/Anti-icing Chemicals》标准试验方法,研究分析了温度、冰点、渗透压和分子大小对飞机除冰液渗透性能的影响。试验结果表明:随着温度的降低,飞机除冰液对冰的渗透性逐渐减小;在相同温度下,牛顿流体型除冰液的渗透性优于非牛顿流体型除冰液;飞机除冰液的冰点和渗透性无直接关系而与渗透压相关,且渗透压越大,对冰的渗透性越好。

  20. 飞机除冰/防冰液的流变特性研究%Rheological properties of aircraft deicing/anti-icing fluid

    Institute of Scientific and Technical Information of China (English)

    张亚博; 赵芯; 于新华; 张帆; 陈元

    2015-01-01

    The non-Newton aircraft deicing/anti-icing fIuid rheoIogicaI property through use of BrookfieId viscometer. By means of the aircraft deicing/anti-icing fIuid shear rate and shear stress measurement and data caIcuIation,found that under the condition of medium shear rate,the aircraft deicing/anti-icing fIuid conforms to the power Iaw. The shear rates tend to be zero and tend to infinity,the aircraft deicing/anti-ic-ing fIuid viscosity is cIose to a constant vaIue. The new rheoIogicaI equation can describe the rheoIogicaI properties of the aircraft deicing/anti-icing fIuid within the fuII scope of the shear rate.%使用BrookfieId粘度计对非牛顿流体型飞机除冰/防冰液的流变性进行了研究,通过对飞机除冰/防冰液剪切速率和剪切应力的测量和数据拟合,发现在中等剪切速率条件下,飞机除冰/防冰液符合幂律流体的流变特性;在剪切率趋近于0和趋近于无穷大时,飞机除冰/防冰液的粘度都是趋近于一个固定值,据此推导出新的流变方程,新流变方程能在整个剪切速率范围内很好的反应飞机除冰/防冰液的流变特性。

  1. 基于GPRS和PLC的飞机地面除冰监控系统%Aircraft ground deicing monitoring system based on GPRS and PLC

    Institute of Scientific and Technical Information of China (English)

    王立文; 陈垣均; 陈斌

    2016-01-01

    针对飞机地面除冰系统的远程管理和维护需求,提出基于 GPRS DTU (data transfer unit)通信模块和 PLC 控制单元的飞机地面除冰远程监控系统方案。通过以松下PLC为主控制单元的飞机地面除冰系统终端,将系统运行状况和故障信息经 GPRS网络实时传送到远程监控中心,经过对远程监控中心上位机软件的操纵,实现对飞机地面除冰系统的远程监测与控制,解决机场特殊环境下对飞机地面除冰信息传输和运行监控的难题。测试结果验证了该方案的可行性。%According to remote management and maintenance requirements of aircraft ground deicing system,the program of air-craft ground deicing remote monitoring system was proposed based on GPRS DTU and PLC control unit.Through aircraft ground deicing system terminal based on Panasonic PLC control unit,the system running status and fault information were real-time sent to the remote monitoring center via the GPRS network.The software of computer monitoring center was operated,re-mote measure and control of aircraft ground deicing system was realized.The problems of information transmitting and operation monitoring about aircraft ground deicing system were solved in the special environment at the airport.Testing results show that the monitoring system program is feasible.

  2. 高压线除冰机器人本体结构设计%Design of Body Structure for a Deicing Robot on the High Voltage Line

    Institute of Scientific and Technical Information of China (English)

    林坚磊; 刘文华; 陈雪; 侯智强; 宋赫

    2015-01-01

    Aiming at icing conditions of high voltage lines, a kind of line deicing robot is proposed. It consists of moving mechanism, climbing obstacle structure, deicing hammer, gear drive and camera system. The robot utilizes the deicing wheel fixed in the fore-end to cut ice, and then the deicing hammer clears up the remaining icing. The driving wheel adopts semi-circular structure to meet a range of diameter and uses a locking mechanism to provide stability for the robot. The robot is of small size and with high efficiency deicing, and cleared icing thickness can reach from10 to 25mm.%针对高压输电线路的覆冰情况,提出了一种线路除冰机器人,该机器人由行走机构、越障机构、除冰工具、传动系统和摄像系统组成。机器人利用固定在前端的除冰砂轮对覆冰切割,而后除冰锤实现180°半圆形往复运动对剩余覆冰进行反复敲打清除;驱动轮采用半圆型结构,适应一定范围的线径,为机器人提供了稳定性。该机器人体积小,除冰效率高,可清除厚度为10~25 mm的覆冰。

  3. Self-response multi-functional composite material base on carbon nanotube paper using deicing, flame retardancy, thermal insulation, and lightning-strike protection

    Science.gov (United States)

    Chu, Hetao; Zhang, Zhichun; Liu, Yanju; Leng, Jinsong

    2015-04-01

    Carbon nanotube paper (CNP) based multi-functional composite material is an attractive candidate for deicing, flame retardancy, thermal insulation and lighting strike protection due to the excellent conductivity, light weight and thin dimensions. In this article, multi-functional carbon nanotube paper was fabricated successfully by using commercial carbon nanotube. As a deicing composite material, carbon nanotube was used directly without pretreatment in fabricating carbon nanotube paper. The conductivities of the carbon nanotube paper and deicing composite were 77.8S/cm and 64.9S/ respectively. Electrical heating and deicing performance were test by infrared camera with deicing time less than 220s and 450s to melt a certain amount of ice under different ambient condition. CNT was grafted by zirconium (IV) butoxide solution and dimethyl dichlorosilicane to form co-oligomers on the tube surface while oligomers decompose under a certain temperature to develop an inorganic layer of silicon zirconium oxide. The oxidizing temperature of carbon nanotube increases more than 20°C and the weight loss rate decreases 20% than the untreated carbon nanotube. Lightning protection material required high electro conductivity, due to the utmost high current in a short time. Therefore, silver nanoparticles were deposited on the surface of carbon nanotube with the diameter around 100nm. The conductivity increased sharply from 84s/cm to1756s/cm with the mount of 5.9wt% Ag of the modified carbon nanotube paper because the silver nanoparticles deposited on the surface. In addition, the silver modified also can be used as thermal insulation material decreasing the infrared radiation.

  4. Salt stains from evaporating droplets

    NARCIS (Netherlands)

    Shahidzadeh, N.; Schut, M.F.L.; Desarnaud, J.; Prat, M.; Bonn, D.

    2015-01-01

    The study of the behavior of sessile droplets on solid substrates is not only associated with common everyday phenomena, such as the coffee stain effect, limescale deposits on our bathroom walls, but also very important in many applications such as purification of pharmaceuticals, deicing of

  5. Salt stains from evaporating droplets

    NARCIS (Netherlands)

    Shahidzadeh, N.; Schut, M.F.L.; Desarnaud, J.; Prat, M.; Bonn, D.

    2015-01-01

    The study of the behavior of sessile droplets on solid substrates is not only associated with common everyday phenomena, such as the coffee stain effect, limescale deposits on our bathroom walls, but also very important in many applications such as purification of pharmaceuticals, deicing of airplan

  6. Instrumentation and monitoring of the nextgen road infrastructure: Some results and perspectives from the R5G project

    Science.gov (United States)

    Hautière, Nicolas; Bourquin, Frédéric

    2017-04-01

    Through the centuries, the roads - which today constitute in France a huge transport network of 1 millions kilometers length - have always been able to cope with society needs and challenges. As a consequence, the next generation road infrastructure will have to take into account at least three societal transitions: ecological, energetic and digital. The goal of the 5th generation road project (R5G©) [1], led by Ifsttar in France, aligned with the Forever Open program [2], is to design and build demonstrators of such future road infrastructures. The goal of this presentation is to present different results related to the greening of road materials [3], the design of energy-positive roads [4, 5], the test of roads that self-diagnose [6], the design of roads adapted for connected [7], autonomous [8] and electrified vehicles [9], etc. In terms of perspectives, we will demonstrate that the road infrastructures will soon become a complex system: On one side road users will benefit from new services, on the other side such massively connected and instrumented infrastructures will potentially become an opportune sensor for knowledge development in geoscience, such as air quality, visibility and fog monitoring. References: [1] R5G project. r5g.ifsttar.fr [2] Forever Open Road project. www.foreveropenroad.eu [3] Biorepavation project. www.infravation.net/projects/BIOREPAVATION [4] N. Le Touz, J. Dumoulin. Numerical study of the thermal behavior of a new deicing road structure design with energy harvesting capabilities. EGU General Assembly 2015, Apr 2015, Vienne, Austria. [5] S. Asfour, F. Bernardin, E. Toussaint, J.-M. Piau. Hydrothermal modeling of porous pavement for its surface de-freezing. Applied Thermal Engineering. Volume 107, 25 August 2016, Pages 493-500 [6] LGV BPL Instrumentation. http://railenium.eu/wp-content/uploads/2016/08/INSTRUMENTATION-BPL-FR.pdf [7] SCOOP@F project. https://ec.europa.eu/inea/en/connecting

  7. 盐冻循环对胶粉改性沥青混合料性能的影响%The Influence that Salt Freezing Cycles have on the Property of Rubber Powder Modified Asphalt Mixture

    Institute of Scientific and Technical Information of China (English)

    冯蕾; 王乐; 崔亚楠; 韩吉伟; 阴福

    2014-01-01

    In winter of cold region,pavements are easily frozen by snow and ice and deicing salt is often used for to melt ice.However,the use of deicing salt can produce erosion of pavement materials.In this article,the freeze-thaw cycle test was conducted to analysis the influence that salt freeze-thaw cycles had on porosity of rubber powder modified asphalt mixture.Temperature,concentration of deicing salt and the number of freeze-thaw cycles were considered in the test.The test was carried out in accordance with the orthogonal principle.The porosity and splitting strength of the specimens were got during the test.It was found that with the increase of salt concentration and the freeze-thaw cycles,porosity of rubber pow-der modified asphalt mixture increased gradually.It showed that deicing salt causes serious damage to the rubber powder modified asphalt of pavement and it is unfavorable to use in a large amount.%冬季寒冷地区路面易积雪结冰,常使用除冰盐进行融雪除冰。除冰盐的使用会对路面材料产生侵蚀。本文通过室内冻融循环试验分析盐冻融循环对胶粉改性沥青混合料的性能的影响。实验中考虑了温度、除冰盐浓度和冻融循环次数三个因素,按照正交原理进行试验,试验测得了试件的孔隙率和劈裂强度。经分析发现,随着盐浓度和冻融循环次数的增加,胶粉改性沥青混合料的孔隙率逐渐变大。说明冬季路面使用的除冰盐对胶粉改性沥青的破坏较严重,不宜大量使用。

  8. Wildland road removal: research needs

    Science.gov (United States)

    T. Adam Switalski; John A. Bissonette; Tom H. Deluca; Charles H. Luce; Mary Ann Madej

    2003-01-01

    Wildland road removal is a common practice across the U.S. and in some parts of Canada. The main types of road removal include ripping, stream crossing restoration, and full recontour. Road removal creates a short-term disturbance that may temporarily increase sediment loss. However, research and long-term monitoring have shown that road removal both reduces erosion...

  9. Direct Optical Ice Sensing and Closed-Loop Controller Design for Active De-icing of Wind Turbines Using Distributed Heating

    Science.gov (United States)

    Shajiee, Shervin

    Ice accumulation on wind turbines operating in cold regions reduces power generation by degrading aerodynamic efficiency and causes mass imbalance and fatigue loads on the blades. Due to blade rotation and variation of the pitch angle, different locations on the blade experience large variations of Reynolds number, Nusselt number, heat loss, and non-uniform ice distribution. Hence, applying different amounts of heat flux in different blade locations can provide more effective de-icing for the same total power consumption. This large variation of required heat flux motivates using distributed resistive heating, with the capability of locally adjusting thermal power as a function of location on the blade. The main contributions of this research are developing the experimental feasibility of direct ice sensing using an optical sensing technique as well as development of a computational framework for implementation of closed-loop localized active de-icing using distributed sensing. A script-base module was developed in a commercial finite-element software (ANSYS) which provides the capability of (i) Closed-loop de-icing simulations for a distributed network of sensors and actuators, (ii) investigating different closed-loop thermal control schemes and their de-icing efficiency (iii) optimizing thermal actuation for a distributed resistive heating, and (iv) analyzing different faulty scenarios for sensors and thermal actuators under known faults in the network. Different surrogate models were used to enhance the computational efficiency of this approach. The results showed that optimal value of control parameters in a distributed network of heaters depends on convective heat transfer characteristics, layout of heaters and type of closed-loop controller scheme used for thermal actuation. Furthermore, It was shown that closed-loop control provides much faster de-icing than the open-loop constant heat flux thermal actuation. It was observed both experimentally and

  10. Road rage and collision involvement.

    Science.gov (United States)

    Mann, Robert E; Zhao, Jinhui; Stoduto, Gina; Adlaf, Edward M; Smart, Reginald G; Donovan, John E

    2007-01-01

    To assess the contribution of road rage victimization and perpetration to collision involvement. The relationship between self-reported collision involvement and road rage victimization and perpetration was examined, based on telephone interviews with a representative sample of 4897 Ontario adult drivers interviewed between 2002 and 2004. Perpetrators and victims of both any road rage and serious road rage had a significantly higher risk of collision involvement than did those without road rage experience. This study provides epidemiological evidence that both victims and perpetrators of road rage experience increased collision risk. More detailed studies of the contribution of road rage to traffic crashes are needed.

  11. Township Administered Roads

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data set contains roadway centerlines for township administered roads found on the USGS 1:24,000 mapping series. In some areas, these roadways are current...

  12. Burkina Faso - Roads

    Data.gov (United States)

    Millennium Challenge Corporation — Impaq worked with the data collection firms NSCE-MCG-AC3E [the Group] to conduct traffic, household, and business surveys as part of the Roads Project evaluation....

  13. Taos County Roads

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Vector line shapefile under the stewardship of the Taos County Planning Department depicting roads in Taos County, New Mexico. Originally under the Emergency...

  14. State Forest Roads

    Data.gov (United States)

    Minnesota Department of Natural Resources — ArcView shape file of roads administered by the Commissioner of Natural Resources to provide access to lands administered by the Division of Forestry. Most, but not...

  15. Road Works Ahead

    Institute of Scientific and Technical Information of China (English)

    Gertrude Majyambere

    2011-01-01

    @@ CHINA will invest about $532 million in Rwanda this year, mainly targeting critical economic engines such as building roads and vocational schools, said Shu Zhan, Chinese Ambassador to Rwanda, in early February.

  16. Kilburn High Road Revisited

    Directory of Open Access Journals (Sweden)

    Cristina Capineri

    2016-07-01

    Full Text Available Drawing on John Agnew’s (1987 theoretical framework for the analysis of place (location, locale and sense of place and on Doreen Massey’s (1991 interpretation of Kilburn High Road (London, the contribution develops an analysis of the notion of place in the case study of Kilburn High Road by comparing the semantics emerging from Doreen Massey’s interpretation of Kilburn High Road in the late Nineties with those from a selection of noisy and unstructured volunteered geographic information collected from Flickr photos and Tweets harvested in 2014–2015. The comparison shows how sense of place is dynamic and changing over time and explores Kilburn High Road through the categories of location, locale and sense of place derived from the qualitative analysis of VGI content and annotations. The contribution shows how VGI can contribute to discovering the unique relationship between people and place which takes the form given by Doreen Massey to Kilburn High Road and then moves on to the many forms given by people experiencing Kilburn High Road through a photo, a Tweet or a simple narrative. Finally, the paper suggests that the analysis of VGI content can contribute to detect the relevant features of street life, from infrastructure to citizens’ perceptions, which should be taken into account for a more human-centered approach in planning or service management.

  17. 架空输电线路除冰机器人的研制%The Manufacturing of a Deicing Robot for Overhead Transmission Lines

    Institute of Scientific and Technical Information of China (English)

    张峰; 郭锐; 赵金龙; 曹雷

    2011-01-01

    Deicing with robotics could be operated on line for the transmission lines to prevent damage.For single line deicing between two towers,a practical deicing robot for overhead transmission lines is manufactured.The robot deices by impacting on ice with fixed tools.Three driving wheels and pressure wheel mechanism could increase friction for driving.A locking mechanism and anti-overturning mechanism are developed for high stability and safety during working.The robot has the advantages of light weight,small size and high deicing efficiency.Many experiments have been carried out on simulative lines and 500 kV live-lines.It is varified that the deicing speed is more than 0.13 m/s,even through the ice diameter is 50 mm.%利用机器人技术实现输电线路在线除冰,可以在不停电的情况下提早消除覆冰隐患,防止重大灾害的发生。针对一档内单股线除冰作业,设计并研制出一种实用性较高的输电线路除冰机器人。该机器人采用固定刀具,前推撞击方式除冰;3个并行排列同时驱动的行走轮与压紧轮机构配合增大摩擦驱动力;采用的锁紧机构和防倾倒机构,确保作业稳定,保障作业安全。该机器人体积小、重量轻、除冰效率高,已经在模拟线路和500 kV带电线路等进行过多次除冰试验,在直径超过50 mm的高硬度覆冰环境下,平均除冰速度可达0.13 m/s。

  18. Ice detection and deicing system improves the economics of a wind turbine in the arctic weather conditions

    Energy Technology Data Exchange (ETDEWEB)

    Maekinen, J. [Labko Ice Detection Oy (Finland)

    1995-12-31

    The Finnish Lapland is an excellent test area for the wind turbines due to strong winds and heavy icing. Also the need of ice protection is evident, for wind turbines cannot be used in the area at all without such devices which keep the blades free of ice, rime frost or heavy snow. Labco Ice Detection Oy has been working in good cooperation with VTT and Kemijoki Oy to solve this problem technically and economically by developing an ice detector and deicing system. This system detects ice when its thickness is 0,5 mm and melts it so that the blades will stay clean during the ice accretion. The enclosed estimation process indicates that the investment in this system is economically profitable. (author)

  19. 不可控12脉波整流的输电线路直流融冰研究%Study on DC De-icing Method Based on Uncontrollable 12-Pulse Rectification for Transmission Line

    Institute of Scientific and Technical Information of China (English)

    罗小龙; 廖振; 彭峰; 郭浩; 胡晓羲

    2012-01-01

    在覆冰输电线路的融冰方法中,与传统的交流融冰法和机械除冰法相比,直流融冰法具有所需电源容量小、高效、方便等优势。研究了采用不可控12脉波整流的直流融冰方法,分析了不可控12脉波整流直流融冰原理,在确定相应型号导线融冰电流的基础上,计算出实现导线融冰所需的融冰电压和交流侧电压,并由此确定整流变压器的额定电压比,分别推导出上下整流桥串/并联两种接线方式条件下覆冰导线的可融长度。仿真结果表明,该方法在不同型号导线的一定长度范围内具有良好的融冰效果,为解决输电线路覆冰问题提供了一种可靠技术。%In many de-icing methods for icing transmission lines, DC de-icing method has many advantages when it is compared to the traditional AC or artificial de-icing method, such as smaller power supply capacity, higher efficiency and convenience. This paper studies a DC de-icing method which is based on uncontrollable 12 pulse rectifier. It analyzes DC de-icing principle of uncontrollable 12 pulse rectification. According to the de-icing current of a given conductor, the AC side voltage and the DC de-icing voltage, which could make the ice covering on the conductor de-iced, will be calculated. Then the rated voltage ratio of rectifying transformer can be easily determined, and the icing conductor's de-icing range is deduced by making the two rectifier bridges connected in series and in parallel. Simulation shows that this method is really efficient to de-ice the ice covering on the transmission line in a certain range. It provides a reliable technology for solving the problem of icing transmission lines.

  20. 公路除冰融雪剂中添加剂的种类及发展%Classification and Development of Ddditives in Highway Deicing

    Institute of Scientific and Technical Information of China (English)

    方降龙; 肖娟定; 胡辉

    2014-01-01

    The classification of additives including corrosion inhibitor, rust inhibitor, soil anti-caking agent, antilubricant, surfactant, chromogenic agent, etc. in highway deicing are summed up, the develop-ment trend of the additives in future is analyzed, which are intended to provide reference for the research about the formula of the additives in deicing.%总结了公路除冰融雪剂中添加剂的种类,包括缓蚀剂、阻锈剂、土壤抗结剂、防滑剂、表面活性剂、显色剂等,分析了添加剂的发展趋势,旨在为融雪剂中添加剂配方研究提供一定的参考。

  1. FORMATION PROCESS AND HISTORICAL FUNCTIONS OF OLD AKIHA ROAD

    Science.gov (United States)

    Nakane, Yoji; Okuda, Masao; Kani, Yukihiko; Hayakawa, Kiyoshi; Matsui, Tamotsu

    An object of this study is the old Akiha road located along the southern parts of the Akaishi Mountains in Sizuoka Prefecture. The old Akiha road between Hamamatsu city in Enshu and Iida city in Shinshu had been utilized by people for the purposes of making a pilgrimage, megalithic faith, transporting obsidian since the primitive age, practicing the mountaineering asceticism, operating the military activities in the warlike age, transporting salt from coastal area to mountainous area and so on. Through the investigation of literature, site reconnaissance and hearing, the formation process and the historical functions of the old Akiha road were studied, including the situation in medieval times or before. As the results, it was elucidated that the oldest road between two cities had located over the Hyoukoshi Pass, the road routes had the lowering trend from mountainside to riverside, and the historical functions of old Akiha road were the passage for transportation of various kinds of goods and human being, faith and culture.

  2. Roads at Pipe Spring National Monument, Arizona 2006 (roads)

    Data.gov (United States)

    National Park Service, Department of the Interior — This is an Arc/Info coverage consisting of 30 arcs representing the roads in Pipe Spring National Monument, Arizona. Twenty-five of the road arcs were collected by a...

  3. Silk Road policy

    Energy Technology Data Exchange (ETDEWEB)

    Nishikawa, Y. [Mitsui Mineral Development Engineering Co., Tokyo (Japan)

    1999-04-01

    Landlocked Asia is blessed with rich mineral and energy resources and has great potential to supply these resources to Europe and eastern Asia. With globalisation of markets progressing rapidly, central Asia is now in the spotlight for its economic activity, as a route for international trade and as the heartland of the `Modern Silk Road` of the 21st century. The article discusses the mineral resources of central Asia, covering Kazakhstan, Uzbekistan, Turkmenistan, Kyrghystan, Xingjiang, and Mongolia. Energy resources of the region, coal, oil and natural gas, are mentioned. International organizations and industrial companies like Japan are supporting the transformation of these vast largely unexplored areas to market economies. Construction of the New Silk Road has begun, under the UNDP, and improvement of the Silk Road railway is also underway, with Japanese funding. 3 figs.

  4. Laboratory-scale evaluation of a combined soil amendment for the enhanced biodegradation of propylene glycol-based aircraft de-icing fluids.

    Science.gov (United States)

    Libisch, Balázs; French, Helen K; Hartnik, Thomas; Anton, Attila; Biró, Borbála

    2012-01-01

    A combined soil amendment was tested in microcosm experiments with an aim to enhance the aerobic biodegradation of propylene glycol (PG)-based aircraft de-icing fluids during and following the infiltration of contaminated snowmelt. A key objective under field conditions is to increase degradation of organic pollutants in the surface soil where higher microbial activity and plant rhizosphere effects may contribute to a more efficient biodegradation of PG, compared to subsoil ground layers, where electron acceptors and nutrients are often depleted. Microcosm experiments were set up in Petri dishes using 50 g of soil mixed with appropriate additives. The samples contained an initial de-icing fluid concentration of 10,000 mg/kg soil. A combined amendment using calcium peroxide, activated carbon and 1 x Hoagland solution resulted in significantly higher degradation rates for PG both at 4 and 22 degrees C. Most probable numbers of bacteria capable of utilizing 10,000 mg/kg de-icing fluid as a sole carbon source were about two orders of magnitude higher in the amended soil samples compared to unamended controls at both temperatures. The elevated numbers of such bacteria in surface soil may be a source of cells transported to the subsoil by snowmelt infiltration. The near-surface application of amendments tested here may enhance the growth of plants and plant roots in the contaminated area, as well as microbes to be found at greater depth, and hence increase the degradation of a contaminant plume present in the ground.

  5. 覆冰四分裂导线除冰过程模拟研究%Numerical simulation study on de-icing process of iced quad-bundled conductor

    Institute of Scientific and Technical Information of China (English)

    严波; 陈科全; 祖正华; 张宏雁; 周松

    2011-01-01

    针对提出的一种覆冰四分裂导线智能除冰方法,采用ABAQUS有限元软件建立覆冰四分裂导线及其除冰装置的有限元模型,实现除冰过程的数值模拟方法.通过数值模拟研究,验证智能除冰方法的可行性.覆冰破坏采用拉伸破坏强度理论,利用ABAQUS的用户材料子程序VUMAT定义覆冰的本构关系和破坏准则,实现破坏单元的删除.通过除冰装置不同张开位移和安装个数以及不同覆冰厚度下除冰效果的模拟研究,为智能除冰装置的设计提供参考.%Numerical model of iced quad-bundled conductor line with new intelligent de-icing equipments was set up by means of ABAQUS software, and the simulation of de-icing process was numerically carried out. The feasibility of the intelligent de-icing method was verified based on the numerical simulation. Tension failure criterion was employed in the simulation of ice failure, and the user material subroutine VUMAT of ABAQUS software was developed to introduce the constitutive relation of ice and the deletion of broken ice elements. Several de-icing scenarios were numerically studied considering the variables including the opening displacement of de-icing equipment,the number of installed de-icing equipments on the line and the thickness of ice covered on the conductors. The obtained numerical results provide a reference for design and realization of intelligent de-icing equipment.

  6. Design of Bridge Deck with Intelligent Temperature Control and Deicing System%智能控温防冻桥面的构思和设计

    Institute of Scientific and Technical Information of China (English)

    谭红霞; 涂莉; 李建男

    2012-01-01

    It is cold winter in China,and the cold weather lasts almost one month in south China and even longer in the north.So,the road surface and bridge deck get iced up easily.The traffic accidents and high-way closures caused by icing will bring huge negative social influence and economic losses,so it is necessary to take effective decicing methods.However,some of the current deicing methods,have both advantages and disadvantages.Accordingly,this paper proposes a new method:replace a row of reinforcement steel bar with steel pipes in the steel mesh and lay heating wires in the pipes to heat up he bridge deck.The entire circuit control system takes the advantage of automatic temperature control.When the deck temperature is lower than 2 ℃,the temperature control system automatically switch on the power,and wires warm up;when the deck temperature is higher than 20 ℃,the temperature control system automatically switch off the power,wires stop warming.In this way,intelligent temperature control is achieved,and at the same time,the deck will not be iced up in low temperature.This system is easy to repair when with a fault,thus ensuring safe transportation.%中国冬季天气寒冷,路面桥面容易结冰,南方结冰期近1个月,北方时间更长.结冰引起的交通事故和高速公路关闭带来巨大的社会影响和经济损失,故急需采取有效的方法防止路面结冰.利用在桥面铺装层中的钢筋网,修改一个方向的钢筋为钢管,钢管中敷设发热丝,对桥面加热,整个电路使用控制系统根据温度变化自动控制.当桥面温度低于2℃时,控温系统自动接通电源,发热丝发热,加热桥面,当桥面温度高于20℃时,控温系统自动断开电源,发热丝停止加热桥面,从而实现温度智能可控,并且低温时路面不会结冰,故障时易于检修,车辆能安全通行.

  7. 除冰剂对机场跑道混凝土抗冻性能影响%Effects of deicing agent on freezing resistance of airfieId pavement concrete

    Institute of Scientific and Technical Information of China (English)

    陈继超; 李玉香; 朱晓燕; 郑召; 付玉龙

    2015-01-01

    The freezing resistance of airport pavement concretes which were immersed in different concentrations of ethylene glycol so-lution was investigated by single side freezing-thawing method,and the amount of samples′s caling was regarded as evaluation parame-ters of the freezing-thawing durability of concrete. Results show that the freezing-thawing damage is the most serious in low salt con-centrations,and when the concentration of ethylene glycol was 3%,freezing-thawing damage reaches the maximum;By the failure mechanism of airport pavement concrete analysis,the damage was significantly affected by the concrete bibulous rate and deicing agent itself freezing inflation rate.%采用单面冻融法,以试件表面剥落量作为混凝土抗冻性能的评定参数,探讨了经不同浓度乙二醇溶液浸泡后的机场道面混凝土的抗冻性能。结果表明,混凝土经中低浓度乙二醇溶液浸泡后,冻融破坏严重,当乙二醇浓度为3%时,冻融破坏达最大值;通过机场道面混凝土破坏机理分析,破坏主要受混凝土中溶液吸入率、除冰剂自结冰膨胀率影响显著。

  8. eRoads

    DEFF Research Database (Denmark)

    Connolly, David

    in the energy demand and carbon dioxide emissions, since they also enable heavy-duty transport to be electrified such as trucks and buses. It is unlikely that these forms of transport will be electrified without electric roads, due to the relatively high cost of on-board battery storage....... battery capacity required for electric vehicles if they are not installed. The electric road and battery electric vehicle scenarios are more efficient and produce less carbon dioxide emissions than their corresponding oil scenarios for two key reasons: 1) the vehicles are more efficient and 2) electric...

  9. Road crash costs.

    OpenAIRE

    2010-01-01

    Road crashes result in all kinds of social costs, such as medical costs, production loss, human losses, property damage, settlement costs and costs due to congestion. Studies into road crash costs and their trends are carried out quite regularly. In 2009, the costs amounted to € 12.5 billion, or 2.2% of the Gross Domestic Product (GDP). Insight into these costs is used for policy preparation and evaluation, and makes it possible to compare them with costs in other areas. Another important app...

  10. Process for cleaning up hard coal mines containing salt water. Verfahren zur Entsorgung von salzwasserfuehrenden Steinkohlenzechen

    Energy Technology Data Exchange (ETDEWEB)

    Hoelter, H.; Igelbuescher, H.; Gresch, H.; Dewert, H.

    1987-03-12

    The process for cleaning up pits with a great deal of salt water in them and the associated high proportion of flotation material is characterized by the fact that the pre-treated salt water content forms a mass with the flotation coal/rock mass, which is burnt to a residue in fluidized-bed combustion, where the residue as a building material containing salt is particularly suitable for building roads and paths secure against frost and for similar building processes.

  11. Road safety performance indicators for the interurban road network.

    NARCIS (Netherlands)

    Yannis, G. Weijermars, W.A.M. Gitelman, V. Vis, M. Chazirisa, A. Papadimitriou, E. & Lima Azevedo, C.

    2013-01-01

    Various road safety performance indicators (SPIs) have been proposed for different road safety research areas, mainly as regards driver behaviour (e.g. seat belt use, alcohol, drugs, etc.) and vehicles (e.g. passive safety); however, no SPIs for the road network and design have been developed. The o

  12. Road safety performance indicators for the interurban road network.

    NARCIS (Netherlands)

    Yannis, G. Weijermars, W.A.M. Gitelman, V. Vis, M. Chazirisa, A. Papadimitriou, E. & Lima Azevedo, C.

    2013-01-01

    Various road safety performance indicators (SPIs) have been proposed for different road safety research areas, mainly as regards driver behaviour (e.g. seat belt use, alcohol, drugs, etc.) and vehicles (e.g. passive safety); however, no SPIs for the road network and design have been developed. The o

  13. Valencia County E-911 Roads

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set contains a vector digital representation of all accessible roads in the county including interstate highways, State highways, county roads and some...

  14. Kansas Road Centerline Fle (KRCF)

    Data.gov (United States)

    Kansas Data Access and Support Center — This version of the Kansas Road Centerline File (0801) represents the first effort to create a statewide roads layer from best available data sources. KGS integrated...

  15. Sierra County E-911 Roads

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set contains a vector digital representation of all accessible roads including interstate highways, State highways, county roads and some city streets in...

  16. VT E911 Road Centerlines

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) EmergencyE911_RDS was originally derived from RDSnn (now called TransRoad_RDS). "Zero-length ranges" in the ROADS layer pertain to grand-fathered...

  17. Grant County E-911 Roads

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set contains a vector digital representation of all accessible roads in the county including interstate highways, State highways, county roads and city...

  18. Supervising road safety in Peru

    OpenAIRE

    Sagástegui, Freddy; Abogado, Adjuntía para el Medio Ambiente, Servicios Públicos y Pueblos Indígenas, Defensoría del Pueblo. Lima, Perú.

    2010-01-01

    In this article some problems in road safety are described, which have been detected by the Ombudsman of Peru, as part of its role of public administration supervisor, amongst these problems we mention: lack of and inadequate elaboration of the statistics on road traffic accidents, the inconsistency of the National Council for Road Security and the lack of responsibility of the local and regional governments reflected by the lack of application of the National Plan of Road Safety. facing ...

  19. Road construction in underground mines

    Energy Technology Data Exchange (ETDEWEB)

    Benke, L.; Benkovics, I.

    1985-01-01

    The need and reasons of road construction for rubber-tyre vehicles in various mine sections are examined. A detailed analysis is given of the direct and indirect influences of underground haulage ways and transport roads on the parameters of mine performance. The various mine road construction technologies are overviewed. Experiences are presented with road construction in the Mecsek Ore Mines Company, Plant 3, Hungary. The cost factors of four construction technologies are compared.

  20. Auctioning Concessions for Private Roads

    NARCIS (Netherlands)

    Ubbels, Barry; Verhoef, Erik

    2004-01-01

    Private toll roads are now seriously considered as an alternative to public (free-access) road infrastructure. Nevertheless, complete private provision without governmental control is only rarely considered. A main consideration against private roads would be that operators would be primarily intere

  1. Run-off-road crashes.

    NARCIS (Netherlands)

    2014-01-01

    In the Netherlands, one-third of all fatalities and one-sixth of all seriously injured are the consequence of run-off-road crashes. The outcome of run-off-road crashes is relatively severe, one fatality in five seriously injured, which is twice the average in the Netherlands. Serious run-off-road cr

  2. The Road Home

    Science.gov (United States)

    O'Shaughnessy, Molly

    2016-01-01

    "Children have the potential to create a world we cannot imagine. This is our hope." In choosing Montessori, O'Shaughnessy says that we are choosing the road less traveled. We are choosing education as an aid to life. We are choosing an approach that respects the innate and unique potential of each child and that calls upon us to serve…

  3. Road-rail vehicle

    NARCIS (Netherlands)

    Evers, J.J.M.

    2002-01-01

    A transport vehicle equipped with a number of first wheel sets, having wheels provided with tires, to which steering means and driving means, if any, are coupled to enable the transport vehicle to be moved over a road surface. The transport vehicle further comprises at least one second wheel set, ha

  4. EARTH ROADS ARE EASY

    Directory of Open Access Journals (Sweden)

    David O. Whitten

    2000-01-01

    Full Text Available The earliest European immigrants in America traveled on waterways and on pathways worn into the earth by animals and Native Americans. Once their communities began to thrive, settlers widened paths and cleared new roads and streets then began experimenting with inexpensive surfacing to reduce dust in dry weather and mud in wet. “Earth Roads Are Easy” investigates materials and techniques used to maintain primitive thoroughfares with a minimum of effort and expense. The options range from the mundane—clay, sand, gravel, calcium chloride, oil, and tar—to the extraordinary—water glass, adobe clay, beet juice, and carpeting.There is no more dfficult problem confronting highway engineers than that of properly constructing and maintaining an earth road. The work may be less spectacular than the construction and maintenance of hard-surfaced roads, but there is greater latitude in location, methods of construction and choice of materials, consequently there is more scope for the exercise of sound judgment on the part of the engineer.1

  5. The great West Road

    CERN Multimedia

    1975-01-01

    From right to centre the 'Nationale 84' relying Meyrin to Saint-Genis. The fence limits Lab I on that side. From bottom the road leading to the double inclined tunnel linking Lab I and Lab II. On the foreground the ISR building (left) and the West Hall (centre).

  6. Mayan Forest Road Projects

    DEFF Research Database (Denmark)

    Conde, Dalia Amor

    2008-01-01

    Road-building projects in the Mayan Biosphere Reserve to connect Mexico and Guatemala were subjected to a cost-benefit evaluation. Up to an estimated 311,000 hectares of jaguar habitat were found to be at risk of deforestation due to these projects. Some of the projects were shown to have negativ...

  7. Road and Street Centerlines, Roads, road surfaces, Published in 2009, Central College.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — , was produced all or in part from Not Provided information as of 2009. It is described as 'Roads, road surfaces'. Data by this publisher are often provided in UTM...

  8. Microbial monitoring and most-probable number of microbes in soils capable of degrading aircraft deicing fluids

    Science.gov (United States)

    Biró, B.; Horváth, N.; Domonkos, M.; French, H. K.

    2012-04-01

    Intensive use of propylene glycol (PG) and potassium formate-(PF) based aircraft de-icing fluids (ADF) are sources of pollution in Northern airports for soil and groundwater. When the contaminated snow melts in the spring, the de-icing chemicals can infiltrate the sandy soil rapidly. The pollutants are known to be degradable by soil microbes, biodegradation however might vary temporally and spatially. Non-invasive monitoring tools are mainly used to outline areas affected by contaminants and to monitor the flow and transport processes. Field sampling and laboratory measurements are required to examine microbial differences in soils, and the activity of PG degraders. The objective of our work was to map this variability using techniques, such as the countable, colony-forming (CFU) aerobic and anaerobic microbial components (bacteria and fungi) in soils and their catabolic enzymatic activity, measured by fluorescein-diacetate (FDA) analysis. Ratio of potential PG degraders was studied by the most probable number (MPN) method. Soil samples from the Gardermoen Airport (Oslo, Norway) were collected during spring 2010, vertically at 0-110 cm below ground level, and horizontally at about 0-154 cm distance from the runway in 5 steps each. A 10-fold soil solution was done in basal medium at 10.000 ppm ADF, added to 96-wells microplates. Growth was tested after incubation at 22 °C for 2 and 4 weeks by iodonitrotetrazolium violet (INT). Cochran table was applied to calculate the MPN values of PG degraders. There were an increasing abundance and activity of aerobic and anaerobic bacteria and fungi found further away from the highly contaminated runway, indicating toxic effects in this area. Also, below the 40cm soil layer a reduced microbial activity could be seen. The most probable number of microbes capable to degrade ADF correlates well with the CFU numbers and the measured FDA enzymatic activity of the soils. Near the most contaminated runway, 3% of the total

  9. Fleet size estimation for spreading operation considering road geometry, weather and traffic

    Directory of Open Access Journals (Sweden)

    Steven I-Jy Chien

    2014-02-01

    Full Text Available Extreme weather conditions(i.e. snow storm in winter time have caused significant travel disruptions and increased delay and traffic accidents. Snow plowing and salt spreading are the most common counter-measures for making our roads safer for motorists. To assist highway maintenance authorities with better planning and allocation of winter maintenance resources, this study introduces an analytical model to estimate the required number of trucks for spreading operation subjective to pre-specified service time constraints considering road geometry, weather and traffic. The complexity of the research problem lies in dealing with heterogeneous road geometry of road sections, truck capacities, spreading patterns, and traffic speeds under different weather conditions and time periods of an event. The proposed model is applied to two maintenance yards with seven road sections in New Jersey (USA, which demonstrates itself fairly practical to be implemented, considering diverse operational conditions.

  10. Verification of road databases using multiple road models

    Science.gov (United States)

    Ziems, Marcel; Rottensteiner, Franz; Heipke, Christian

    2017-08-01

    In this paper a new approach for automatic road database verification based on remote sensing images is presented. In contrast to existing methods, the applicability of the new approach is not restricted to specific road types, context areas or geographic regions. This is achieved by combining several state-of-the-art road detection and road verification approaches that work well under different circumstances. Each one serves as an independent module representing a unique road model and a specific processing strategy. All modules provide independent solutions for the verification problem of each road object stored in the database in form of two probability distributions, the first one for the state of a database object (correct or incorrect), and a second one for the state of the underlying road model (applicable or not applicable). In accordance with the Dempster-Shafer Theory, both distributions are mapped to a new state space comprising the classes correct, incorrect and unknown. Statistical reasoning is applied to obtain the optimal state of a road object. A comparison with state-of-the-art road detection approaches using benchmark datasets shows that in general the proposed approach provides results with larger completeness. Additional experiments reveal that based on the proposed method a highly reliable semi-automatic approach for road data base verification can be designed.

  11. Is road safety management linked to road safety performance?

    Science.gov (United States)

    Papadimitriou, Eleonora; Yannis, George

    2013-10-01

    This research aims to explore the relationship between road safety management and road safety performance at country level. For that purpose, an appropriate theoretical framework is selected, namely the 'SUNflower' pyramid, which describes road safety management systems in terms of a five-level hierarchy: (i) structure and culture, (ii) programmes and measures, (iii) 'intermediate' outcomes'--safety performance indicators (SPIs), (iv) final outcomes--fatalities and injuries, and (v) social costs. For each layer of the pyramid, a composite indicator is implemented, on the basis of data for 30 European countries. Especially as regards road safety management indicators, these are estimated on the basis of Categorical Principal Component Analysis upon the responses of a dedicated road safety management questionnaire, jointly created and dispatched by the ETSC/PIN group and the 'DaCoTA' research project. Then, quasi-Poisson models and Beta regression models are developed for linking road safety management indicators and other indicators (i.e. background characteristics, SPIs) with road safety performance. In this context, different indicators of road safety performance are explored: mortality and fatality rates, percentage reduction in fatalities over a given period, a composite indicator of road safety final outcomes, and a composite indicator of 'intermediate' outcomes (SPIs). The results of the analyses suggest that road safety management can be described on the basis of three composite indicators: "vision and strategy", "budget, evaluation and reporting", and "measurement of road user attitudes and behaviours". Moreover, no direct statistical relationship could be established between road safety management indicators and final outcomes. However, a statistical relationship was found between road safety management and 'intermediate' outcomes, which were in turn found to affect 'final' outcomes, confirming the SUNflower approach on the consecutive effect of each layer.

  12. Competitiveness in Road Transport

    DEFF Research Database (Denmark)

    Borgström, Benedikte; Gammelgaard, Britta; Bruun, Poul

    Road transport is an important sector, connecting time and space of production and consumption. Its market conditions has changed. The EU single market implementation has increased price pressure due to supply of low cost road freight transport from counties with lower cost structures. Changes....... In this paper we will explore that knowledge gap and analyze what value proposition(s) and capabilities can transform potential cost disadvantages of acting in a market that includes both high- and low-cost-country actors? And in conceptual terminology, how are capabilities deployed and developed to construct...... take into account logistics service supplier strategic management. We also contribute with better understanding of value creation in order to escape commoditization and differentiate services through relationships (customers and/or other hauliers). Practical implications concern hauliers’ strategy...

  13. The road coloring problem

    CERN Document Server

    Trahtman, A N

    2007-01-01

    The synchronizing word of deterministic automaton is a word in the alphabet of colors (considered as letters) of its edges that maps the automaton to a single state. A coloring of edges of a directed graph is synchronizing if the coloring turns the graph into deterministic finite automaton possessing a synchronizing word. The road coloring problem is a problem of synchronizing coloring of directed finite strongly connected graph with constant outdegree of all its vertices if the greatest common divisor of lengths of all its cycles is one. The problem was posed by Adler, Goodwyn and Weiss over 30 years ago and evoked a noticeable interest among the specialists in theory of graphs, deterministic automata and symbolic dynamics. The problem is described even in "Vikipedia" - the popular Internet Encyclopedia. The positive solution of the road coloring problem is presented.

  14. Road Traffic Noise

    Science.gov (United States)

    Beckenbauer, Thomas

    Road traffic is the most interfering noise source in developed countries. According to a publication of the European Union (EU) at the end of the twentieth century [1], about 40% of the population in 15 EU member states is exposed to road traffic noise at mean levels exceeding 55 dB(A). Nearly 80 million people, 20% of the population, are exposed to levels exceeding 65 dB(A) during daytime and more than 30% of the population is exposed to levels exceeding 55 dB(A) during night time. Such high noise levels cause health risks and social disorders (aggressiveness, protest, and helplessness), interference of communication and disturbance of sleep; the long- and short-term consequences cause adverse cardiovascular effects, detrimental hormonal responses (stress hormones), and possible disturbance of the human metabolism (nutrition) and the immune system. Even performance at work and school could be impaired.

  15. Environmentally friendly road construction

    Directory of Open Access Journals (Sweden)

    A.I. Essawy

    2013-06-01

    Full Text Available Environmental pollution is a major problem in developing countries like Egypt. Reuse of waste polymers is considered an attractive solution for environmental white pollution and reducing of the costs of road pavement and maintenance. This research aims to prepare environmentally friendly hot mix asphalt (HMA for paving using some industrial wastes as polypropylene and polyester fibers. The solid materials in the mix include normal and highly porous aggregates. 5% and 10% of waste polymers by weight of the asphalt were used to prepare special binders. The samples were tested for their physical properties, chemical properties, aging, scanning electron microscopy (SEM and thermo-gravimetric analysis (TGA. The results revealed that the prepared HMA using 5% of waste polymer had high performance as compared to the ordinary one and the waste polymer could be used in road construction.

  16. Competitiveness in Road Transport

    DEFF Research Database (Denmark)

    Borgström, Benedikte; Gammelgaard, Britta; Bruun, Poul

    take into account logistics service supplier strategic management. We also contribute with better understanding of value creation in order to escape commoditization and differentiate services through relationships (customers and/or other hauliers). Practical implications concern hauliers’ strategy...... a competitive value proposition? We will illustrate the strategy-as-practice with two projects, and discuss implications in terms of capabilities needed to create an effective value proposition and hence competitiveness. The theoretical contribution is in theorizing haulier strategic development in which we...... in the market also encourage strategic development of some road hauliers into providers of unique services. Such road haulier strategic development contributes to efficiency and effectiveness in basically all business sectors of EU. Little research is available of such strategic and operational management...

  17. Tweets on the road

    CERN Document Server

    Lenormand, Maxime; Colet, Pere; Ramasco, José J

    2014-01-01

    The pervasiveness of mobile devices, which is increasing daily, is generating a vast amount of geo-located data allowing us to gain further insights into human behaviors. In particular, this new technology enables users to communicate through mobile social media applications, such as Twitter, anytime and anywhere. Thus, geo-located tweets offer the possibility to carry out in-depth studies on human mobility. In this paper, we study the use of Twitter in transportation by identifying tweets posted from roads and rails in Europe between September 2012 and November 2013. We compute the percentage of highway and railway segments covered by tweets in 39 countries. The coverages are very different from country to country and their variability can be partially explained by differences in Twitter penetration rates. Still, some of these differences might be related to cultural factors regarding mobility habits and interacting socially online. Analyzing particular road sectors, our results show a positive correlation b...

  18. The behaviour of salt and salt caverns

    NARCIS (Netherlands)

    Fokker, P.A.

    1995-01-01

    Salts are mined for both storage and extraction purposes, either via dry or solution mining techniques. For operational, environmental and geological purposes, it is important to understand and predict the in situ behaviour of salt, in particular the creep and strength characteristics. A micro-mecha

  19. Ice Control with Brine on Highways

    DEFF Research Database (Denmark)

    Bolet, Lars

    During the years 1996-2006, the Division of Highways and Transportation in the former county of Funen gradually replaced pre-wetted salt with brine as de-icing agent in all her ice control activities. The replacement related to 1000 kilometres of highways. Jeopardizing neither road safety nor...

  20. Dynamically loaded beam failure under corroded conditions

    NARCIS (Netherlands)

    Veerman, R.P.; Koenders, E.A.B.

    2014-01-01

    De-icing salts, used on roads in heavy winters, may enter reinforced concrete (RC) structures via its capillary pore system or via cracks, initiating reinforcement corrosion and reducing its remaining service-life. Vehicles passing real bridges exert a dynamic impact action that might activate a fat

  1. August: Road Movies

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Eldorado France, 2008 85' Road movie Directed by: Bouly Lanners Cast: Bouly Lanners, Fabrice Adde Philippe Nahon Yvan is an auto salesman who makes a good living dealing in American luxury cars. One evening, Yvan comes home to discover a burglar has made his way into his home, and a quick search reveals the criminal, Elie is hiding under his bed, and when the thief finally emerges he turns out to be a junkie who is feeling the first stages of withdrawal.

  2. Snow Roads and Runways

    Science.gov (United States)

    1990-11-01

    CONSTRUCT ROADS FOR MARCHING COLUMNS ALL ARMS (1) Pass over the trace twice with (1) Two passes with the harrow the harrow. and roller. (2) After harrowing...should be accomplished by successive passes with beams or slabs to the towing bars. A method forballasting D-7 orD-8 tractortracks. Normally twoto five... waffle -type snow surface (Fig. 85)and is notas suitable for snow pavement surface has been previously compacted snow compaction as other types of rollers

  3. Assessing Road Traffic Expression

    Directory of Open Access Journals (Sweden)

    Fábio Silva

    2014-12-01

    Full Text Available Road traffic is a problem which is increasing in cities with large population. Unrelated to this fact the number of portable and wearable devices has also been increasing throughout the population of most countries. With this advent, the capacity to monitor and register data about people habits and locations as well as more complex data such as intensity and strength of movements has created an opportunity to contribute to the general wealth and comfort within these environments. Ambient Intelligence and Intelligent Decision Making processes can benefit from the knowledge gathered by these devices to improve decisions on everyday tasks such as deciding navigation routes by car, bicycle or other means of transportation and avoiding route perils. The concept of computational sustainability may also be applied to this problem. Current applications in this area demonstrate the usefulness of real time system that inform the user of certain conditions in the surrounding area. On the other hand, the approach presented in this work aims to describe models and approaches to automatically identify current states of traffic inside cities and use methods from computer science to improve overall comfort and the sustainability of road traffic both with the user and the environment in mind. Such objective is delivered by analyzing real time contributions from those mobile ubiquitous devices to identifying problematic situations and areas under a defined criteria that have significant influence towards a sustainable use of the road transport infrastructure.

  4. Cooking without salt

    Science.gov (United States)

    DASH diet; High blood pressure - DASH; Hypertension - DASH; Low-salt diet - DASH ... Explore cooking with salt substitutes. Add a splash of lemon and other citrus fruits, or wine, to soups and other dishes. Or use them ...

  5. The effects of salt on rheological properties of asphalt after long-term aging.

    Science.gov (United States)

    Yu, Xin; Wang, Ying; Luo, Yilin; Yin, Long

    2013-01-01

    Limited studies in recent years have shown that asphalt pavement subject to seawater in coastal regions or deicing salt in cold regions may be seriously damaged after being soaked in saline water for a long time. However, there is limited research into the influence of salt on rheological properties of asphalt after long-term aging. In this study, rheological properties of unmodified and polymer-modified asphalt after long-term aging were tested after being soaked in different concentrations of salt (0.3%~5%) for different durations (1 day~30 days). Orthogonal array based on the Taguchi method was used for experimental design. The frequency sweep tests were performed on the specimens of aged asphalt after being soaked for complex modulus and phase angle master curves and ultimate fatigue temperature. BBR tests were performed for stiffness. The test results indicate that saline water appears to reduce low temperature properties and fatigue resistance properties and improved high temperature properties of aged asphalt, and it also affects the sensitivity of complex modulus and phase angles at low frequencies.

  6. The Effects of Salt on Rheological Properties of Asphalt after Long-Term Aging

    Directory of Open Access Journals (Sweden)

    Xin Yu

    2013-01-01

    Full Text Available Limited studies in recent years have shown that asphalt pavement subject to seawater in coastal regions or deicing salt in cold regions may be seriously damaged after being soaked in saline water for a long time. However, there is limited research into the influence of salt on rheological properties of asphalt after long-term aging. In this study, rheological properties of unmodified and polymer-modified asphalt after long-term aging were tested after being soaked in different concentrations of salt (0.3%~5% for different durations (1 day~30 days. Orthogonal array based on the Taguchi method was used for experimental design. The frequency sweep tests were performed on the specimens of aged asphalt after being soaked for complex modulus and phase angle master curves and ultimate fatigue temperature. BBR tests were performed for stiffness. The test results indicate that saline water appears to reduce low temperature properties and fatigue resistance properties and improved high temperature properties of aged asphalt, and it also affects the sensitivity of complex modulus and phase angles at low frequencies.

  7. Road traffic injuries in Mozambique.

    Science.gov (United States)

    Romão, Francelina; Nizamo, Hanifa; Mapasse, Domingos; Rafico, Momede Mussá; José, João; Mataruca, Simão; Efron, M Lúcia; Omondi, Lucas O; Leifert, Thelma; Bicho, Joaquim M L Marungo

    2003-01-01

    Road traffic injuries affect the economy, health and quality of life of the people of Mozambique. Current road safety programmes are inadequate and inefficient given the magnitude of the problem. Data reported on road traffic crashes in the period 1990 to 2000 from the National Institute for Road Safety, the traffic police and the Central Hospital of Maputo were reviewed. The burden of road traffic injuries in Mozambique is rising, with at least three people killed daily. The age group most affected is 25-38 (39.35%), followed by 16-24 (20.79%). The main causes of crashes include reckless driving, drunken driving, roads with potholes, inadequate signs, lack of protection for pedestrians, and inadequate traffic law enforcement. However, the data are not adequate to reveal the true magnitude of the problem. Data collected by different sources are incomplete and not coordinated with other sources and databases. In urban areas, however, better response to crashes, treatment of the injured, reporting and data collection is attributable to a greater concentration of police and medical facilities. Road traffic safety programmes in Mozambique are inadequate and inefficient, starting with the data collection system. Improvement of injury surveillance systems is needed to help make road traffic safety a national development agenda priority and for developing and implementing road safety policies. For road safety programmes to be effective, government must facilitate stakeholders' involvement, and the clear definition of government activities, civil society activities and public-private partnerships need to be established.

  8. Optimal Road Capacity Building : Road Planning by Marginal Cost Pricing

    OpenAIRE

    NEMOTO, Toshinori; Misui, Yuki; Kajiwara, Akira

    2009-01-01

    The purpose of this study is to propose a new road planning and financing scheme based on short-term social marginal cost pricing that facilitates the establishment of optimal road standards in the long term. We conducted a simulation analysis based on the proposed planning scheme and observed that the simulation calculated the optimal road capacity in the future, and thus proved that the new planning scheme is feasible.

  9. Gender stereotypes among road users

    OpenAIRE

    Dontsov, Alexander; Kabalevskaya, Alexandra

    2013-01-01

    This article analyzes the mechanism of stereotyping as exemplified by gender stereotypes of road users. Gender stereotypes are not only viewed as an a priori image of a percept, but also examined ‘in action’ at the very moment of their actualization with road users. In the paper we have identified the content of road users’ gender stereotypes; analyzed the behaviour of male and female drivers, pinpointing a number of gender-specific behavioural features; demonstrated that male and female driv...

  10. The salts of Mars

    Science.gov (United States)

    Clark, B. C.; Van Hart, D. C.

    1981-01-01

    Salt compounds are apparently an important component of the fine-grained regolith on Mars. Salt enrichment may be explained either as a secondary concentration of chemical weathering products or as direct incorporation of planetary released volatiles. Geochemical measurements and chemical relationships constrain the salt species and resultant physicochemical consequences. A likely assemblage is dominated by (Mg,Na)SO4, NaCl, and (Mg,Ca)CO3. Formation of brine in equilibrium with such a salt mixture is unlikely under the temperature and water-vapor restrictions prevalent over most, if not all, of the Martian surface. Acidic conditions, accompanying salt formation, favor the preferential destruction of susceptible igneous minerals.

  11. 24 CFR 1710.110 - Roads.

    Science.gov (United States)

    2010-04-01

    ... (4) Who is responsible for road maintenance? If the roads are to be maintained by a public authority... for maintaining the roads and that, if maintenance is not performed, the roads may soon deteriorate... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Roads. 1710.110 Section...

  12. 覆冰导线机械式冲击除冰模拟研究%Numerical simulations of mechanical de-icing for iced transmission lines

    Institute of Scientific and Technical Information of China (English)

    陈科全; 严波; 刘小会; 程皓月

    2012-01-01

    A numerical model consisting of adjacent spans and insulator strings of a multi-span iced transmission line section was set up with ABAQUS software. The user-defined material subroutine VUMAT of ABAQUS software was developed for introducing a porous elastic constitutive model of ice and deleting pipe elements used to model broken ice with a tensile failure criterion. A large number of de-icing scenarios were studied with parametric variables including number of spans per line section, span length, ice porosity, ice thickness, temperature and different amplitudes of shock-loads. Based on above numerical simulations, the effects of adjacent span and insulator strings on the rate of de-icing were analyzed and discussed. It was shown that the process of de-icing after loading is affected obviously by all the above parameters except temperature. The obtained numerical results provided a reference for design of de-icing technique in practice.%采用ABAQUS有限元软件建立覆冰导线有限元模型,利用用户材料子程序VUMAT定义覆冰本构模型和删除破坏单元,实现冲击载荷作用下导线除冰过程的模拟.覆冰采用多孔弹性模型,并考虑温度和孔隙率对其力学性能的影响;引入拉伸破坏准则判断覆冰的破坏.对不同档数、档距、覆冰孔隙率、覆冰厚度、除冰时的温度、冲击载荷大小等情况下除冰过程的模拟分析表明,较小范围温度的变化对除冰率的影响很小,而其它因素对除冰效果的影响明显,在设计机械式冲击除冰装置时应予以考虑.

  13. Road traffic noise and stroke

    DEFF Research Database (Denmark)

    Sørensen, Mette; Hvidberg, Martin; Andersen, Zorana J

    2011-01-01

    Epidemiological studies suggest that long-term exposure to road traffic noise increases the risk of cardiovascular disorders. The aim of this study was to investigate the relation between exposure to road traffic noise and risk for stroke, which has not been studied before.......Epidemiological studies suggest that long-term exposure to road traffic noise increases the risk of cardiovascular disorders. The aim of this study was to investigate the relation between exposure to road traffic noise and risk for stroke, which has not been studied before....

  14. 融雪剂对桥梁的破坏和影响%On deicing salt damage and the impact on the bridge

    Institute of Scientific and Technical Information of China (English)

    杨哲斌

    2014-01-01

    本文围绕国内外融雪剂对桥梁结构的破坏机理,说明融雪剂对桥梁钢筋混凝土结构的破坏作用,提出减少氯盐类融雪剂危害性的措施,提高我国路桥使用耐久性的措施.

  15. Road Works Ahead

    Institute of Scientific and Technical Information of China (English)

    Gertrude; Majyambere

    2011-01-01

    China to invest $532 million in Rwanda in 2011 CHINA will invest about $532 million in Rwanda this year,mainly targeting critical economic engines such as building roads and vocational schools,said Shu Zhan,Chinese Ambassador to Rwanda,in early February. "We need to have adequate field surveys,wide consultation and detailed ’homework,’ in order to come up with tailor-made solutions that meet local needs," Shu said in an interview with ChinAfrica.

  16. RoadTrip Charcoal

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Apple iPod系列产品最让人遗憾的地方,就是缺少对于调频收音机的支持。所以我们只好通过各种配件为它增加功能。这款RoadTrip“巧克力”,不仅能让iPod增加收音机的功能,还可以通过调频把iPod中的音乐发出出来。

  17. Road traffic injuries

    Institute of Scientific and Technical Information of China (English)

    WANG Zheng-guo 王正国

    2003-01-01

    @@ The appearance of cars has raised materialistic civilization and living standard to an unprecedented level. Today, it is hard to imagine how we human beings can live without cars.Yet, motor vehicles can cause a great number of deaths and injuries as well as considerable economic losses, which have constituted the global burden. Understanding of the occurrence and development of road traffic injuries will contribute to the prevention and control of crash and to the implementation of "everybody has the right to enjoy health" proposed by WHO.

  18. Road Traffic Injuries

    Institute of Scientific and Technical Information of China (English)

    WANG Zheng-guo

    2005-01-01

    @@ As everybody knows that automobiles have been greatly changing our life. However, everything has two sides, motor vehicles have also caused a huge number of people's deaths, injuries and property damage. Traffic crashes are perhaps the number one public health problem in developed countries [1]. In the United States, pre-retirement years of life lost in traffic crashes are more than that of the two combined leading diseases: cancer and heart disease [1]. Today road traffic crash (RTC) ranks 11th in leading cause of death and accounts for 2.1% of all deaths globally.

  19. Improving road safety: Experiences from the Netherlands

    NARCIS (Netherlands)

    Hagenzieker, M.P.

    2012-01-01

    Dr. Hagenzieker's research and education activities focus on the road safety effects of the transport system, with particular interest in road user behaviour aspects. Her PhD-research was on the effects of rewards on road user behaviour.

  20. In–Service Road Safety Audits

    National Research Council Canada - National Science Library

    A. Mendoza–Díaz; E. Abarca–Pérez; A.G. Centeno–Saad

    2009-01-01

    A road safety audit is a formal analysis that seeks to guarantee that an existing or future road fulfills optimal safety criteria, conducted by a team of experts who se members are independent of the road project...

  1. All Road Density (18km)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Density (km / km^2) of all roads in the western United States. Dataset was developed to generalize the 2000 US Census TIGER/Line Roads layer to a density within 18km...

  2. Road safety in developing countries.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1991-01-01

    This paper presents a classification of countries (developing and developed alike), divided into two main categories: an economical and historical entry. When road safety problems are placed into the economical context, it then appears that, among other things: (1) The road safety problem in the ind

  3. Submarine Salt Karst Terrains

    Directory of Open Access Journals (Sweden)

    Nico Augustin

    2016-06-01

    Full Text Available Karst terrains that develop in bodies of rock salt (taken as mainly of halite, NaCl are special not only for developing in one of the most soluble of all rocks, but also for developing in one of the weakest rocks. Salt is so weak that many surface-piercing salt diapirs extrude slow fountains of salt that that gravity spread downslope over deserts on land and over sea floors. Salt fountains in the deserts of Iran are usually so dry that they flow at only a few cm/yr but the few rain storms a decade so soak and weaken them that they surge at dm/day for a few days. We illustrate the only case where the rates at which different parts of one of the many tens of subaerial salt karst terrains in Iran flows downslope constrains the rates at which its subaerial salt karst terrains form. Normal seawater is only 10% saturated in NaCl. It should therefore be sufficiently aggressive to erode karst terrains into exposures of salt on the thousands of known submarine salt extrusions that have flowed or are still flowing over the floors of hundreds of submarine basins worldwide. However, we know of no attempt to constrain the processes that form submarine salt karst terrains on any of these of submarine salt extrusions. As on land, many potential submarine karst terrains are cloaked by clastic and pelagic sediments that are often hundreds of m thick. Nevertheless, detailed geophysical and bathymetric surveys have already mapped likely submarine salt karst terrains in at least the Gulf of Mexico, and the Red Sea. New images of these two areas are offered as clear evidence of submarine salt dissolution due to sinking or rising aggressive fluids. We suggest that repeated 3D surveys of distinctive features (± fixed seismic reflectors of such terrains could measure any downslope salt flow and thus offer an exceptional opportunity to constrain the rates at which submarine salt karst terrains develop. Such rates are of interest to all salt tectonicians and the many

  4. Gender Stereotypes among Road Users

    Directory of Open Access Journals (Sweden)

    Kabalevskaya, Alexandra I.

    2013-09-01

    Full Text Available This article analyzes the mechanism of stereotyping as exemplified by gender stereotypes of road users. Gender stereotypes are not only viewed as an a priori image of a percept, but also examined ‘in action’ — at the very moment of their actualization with road users. In the paper we have identified the content of road users’ gender stereotypes; analyzed the behaviour of male and female drivers, pinpointing a number of gender-specific behavioural features; demonstrated that male and female driving differ from each other in terms of speed, intensity and roughness; and identified the conditions and mechanisms underlying the actualization of gender stereotypes. Based on video and audio materials, we have found that drivers’ gender-specific behavioural features are perceivable to road users: such features trigger the actualization of gender stereotypes as attributive schemes, which determine the interaction between road users, while also laying the foundation for gender stereotypes.

  5. PID parameters optimization for deicing robot joint controller.%除冰机器人关节控制PID参数优化

    Institute of Scientific and Technical Information of China (English)

    谢岚; 孙炜; 赵国瑞

    2011-01-01

    针对输电线除冰机器人的关节运动,提出一种改进的无刷直流电机控制策略,利用粒子群算法优化不完全微分控制算法来代替传统的PID控制,对Kp、Ti、Td进行全局优化·实验结果表明,该方法明显提高了控制性能,具有很强的鲁棒性,能够满足除冰机器人对控制系统高精度、实时性的要求.%To control the motion of the joints of deicing robot on power transmission line,an improved brushless DC motor control strategy is proposed,which utilizes PSO algorithm to optimize the parameters of PID controller with incomplete derivation instead of the traditional PID control.Three parameters of Kp, Ti , and Td are overall optimized. The results of experiments show that the control performance of the proposed method is improved dramatically and is highly robust which can meet high-precision and real-time requirements of the deicing robot.

  6. Road safety performance indicators for the interurban road network.

    Science.gov (United States)

    Yannis, George; Weijermars, Wendy; Gitelman, Victoria; Vis, Martijn; Chaziris, Antonis; Papadimitriou, Eleonora; Azevedo, Carlos Lima

    2013-11-01

    Various road safety performance indicators (SPIs) have been proposed for different road safety research areas, mainly as regards driver behaviour (e.g. seat belt use, alcohol, drugs, etc.) and vehicles (e.g. passive safety); however, no SPIs for the road network and design have been developed. The objective of this research is the development of an SPI for the road network, to be used as a benchmark for cross-region comparisons. The developed SPI essentially makes a comparison of the existing road network to the theoretically required one, defined as one which meets some minimum requirements with respect to road safety. This paper presents a theoretical concept for the determination of this SPI as well as a translation of this theory into a practical method. Also, the method is applied in a number of pilot countries namely the Netherlands, Portugal, Greece and Israel. The results show that the SPI could be efficiently calculated in all countries, despite some differences in the data sources. In general, the calculated overall SPI scores were realistic and ranged from 81 to 94%, with the exception of Greece where the SPI was relatively lower (67%). However, the SPI should be considered as a first attempt to determine the safety level of the road network. The proposed method has some limitations and could be further improved. The paper presents directions for further research to further develop the SPI.

  7. 用于碳纤维复合材料的电热除冰技术实验研究%Experimental Study on Electro-thermal Deicing Technique for Carbon Fiber Composite

    Institute of Scientific and Technical Information of China (English)

    马莉娅; 熊联友; 刘立强; 杨娇萍; 杨岩峰

    2012-01-01

    Based on recent research of electro-thermal deicing technique for carbon fiber composite airfoil, a multi-material structure is proposed. The deicer pad consistes of multi-materials, each with specific thermal properties. Some of these materials are manufactured in the laboratory based on the property requirements. The finite volume method (FVM) is adopted to simulate the performance of the deicing pad, and the proper thickness of the insulation layer is determined. Through numerical simulation the uniformity of the heating circuit is also verified. According to the scheme an electro-thermal deicer pad is developed, and a deicing validation device is designed and adopted to carry out the experimental study on the performance of the deicer pad. The impact of heat flux, airflow velocity and the angle between the airflow and the deicing surface on the deicing performance is studied. The study shows that the electro-thermal deicer pad so designed is able to provide good deicing performance, and that the proposed deicing scheme is feasible.%针对碳纤维复合材料机翼的电热除冰技术研究现状,提出了采用多层材料结构的电热除冰垫技术方案.该电热除冰垫各层均由具有不同热功能的材料构成,其中部分材料为根据性能需要自行制备得到的.采用有限容积法(FVM)对除冰垫的性能进行了数值模拟,确定了隔热层厚度,验证了加热回路的均匀性.根据所确定的方案制备了电热除冰垫,并利用自行搭建的除冰验证装置对该电热除冰垫的性能进行了实验研究,得到了加热热流密度、来流风速、来流与除冰表面间夹角对除冰性能的影响规律.研究表明,该电热除冰垫具有良好的除冰性能,除冰方案可行.

  8. Analysis on DC Deicing Process and Efficiency in China Southern Power Grid%南方电网主网架直流融冰工作流程与融冰效率研究

    Institute of Scientific and Technical Information of China (English)

    陈彦州; 王奇; 蔡延雷; 顾保全; 吴黎黎; 谢辰昱

    2013-01-01

    The China Southern Power Grid (CSG) has installed 6 sets of DC deicers on its backbone transmission grid since the ice disaster in 2008,among which the DC deicer in Gaopo substation of Gao-Zhao ±500 kV DC transmission lines is the first OPGW deicer in CSG.Most of the existing DC deicing researches concern the analyses of provincial power grid and transmission lines.However,the icing on overhead ground lines has become the secondary influencing factor in the causation of power system fault in winter.In this paper,the above 6 sets of DC deicers are described with emphasis on the OPGW deicer,and the deicing process and efficiency after the installation of deicing switches are analyzed.The feasibility and necessity of OPGW deicing is discussed,and suggestion of making a DC deicing process and installing deicing switches is offered to improve deicing efficiency.%自2008年冰灾后,南方电网在西电东送主网架输电通道中加装了6套直流融冰装置,其中高肇直流高坡站直流融冰装置为南方电网首套高压直流输电线OPGW融冰装置.现有的研究工作大多只涉及线路两侧未安装融冰短接刀闸情况下相线融冰技术的研究与计算,实际上,地线覆冰是仅次于相线覆冰的影响系统冰期安全运行的因素,融冰短接刀闸的装设能够大大提高融冰效率.在此背景下,笔者介绍了6套直流融冰装置特别是高坡站OPGW直流融冰装置的概况,分析了基于覆冰预警系统的直流融冰工作流程及安装融冰短接刀闸前后的融冰效率.最后,对分析结果进行了总结,指出OPGW融冰具有可行性和必要性,并建议制定工作流程、加装融冰刀闸以提高融冰效率.

  9. Environmental Simulation and Experimental Study of Aircraft Icing and Deicing on Ground%飞机地面积/除冰环境模拟与试验研究

    Institute of Scientific and Technical Information of China (English)

    陈斌; 张浩; 王立文

    2011-01-01

    飞机地面积冰是飞机进入冬季安全飞行的重要隐患,很多飞行事故都是因为没有清除飞机表面的积冰而造成的.基于对飞机地面积/除冰的真实环境的分析,在低温湿热试验箱中模拟积/除冰时的大气条件,对机翼积/除冰进行试验研究.通过改变环境温度、除冰液温度、流量、浓度等影响因素,利用光纤式结冰传感器得到不同环境条件下,除冰液参数对除冰过程的影响数据,并对这些数据进行了分析.试验结果表明该装置能有效地模拟飞机地面积/除冰过程,数据分析显示飞机地面结冰过程主要受外界环境温度,湿度(空气的水含量)的影响;对飞机地面除冰来说,除冰液温度参数是除冰效果达到最佳的关键因素.%Aircraft icing on ground is a major danger for flight safety in winter, and numerous flight accidents could attribute to not having cleared the ice on the aircraft body before takeoff. An atmosphere icing weather condition was simulated in a low temperature cabin to imitate aircraft deicing on ground based on the study of aircraft ice mechanism on ground. Then several conditions, such as deicing fluids temperature , flow rate and scale, were changed to study the influencing factors on the aircraft deicing process u-sing fiber-optic icing sensors. Experimental results show that the aircraft deicing simulation environment could effectively simulate the deicing/icing process. Moreover, analysis results reveal that the environment temperature, humidity are the main parameters for the aircraft icing process and the deicing fluids temperature is the key factor to obtain ideal deicing effect.

  10. Silk Roads or Steppe Roads? The Silk Roads in World History.

    Science.gov (United States)

    Christian, David

    2000-01-01

    Explores the prehistory of the Silk Roads, reexamines their structure and history in the classical era, and explores shifts in their geography in the last one thousand years. Explains that a revised understanding of the Silk Roads demonstrates how the Afro-Eurasian land mass has been linked by networks of exchange since the Bronze Age. (CMK)

  11. Road safety in practice

    CERN Multimedia

    2003-01-01

    On the 23 and 25 September come and test your driving skills and your reflexes on the two days of road safety in practice! To conclude the poster and article campaign on this topic which started last year, CERN now comes to the practical part with demonstrations, like a spectacular overturning test, information stands, where you can meet safety personnel from France, Switzerland and CERN, and discussions & debates. Come to ... ... the Meyrin site on 23 September: - From 8:30 hrs, stands and demonstrations on the parking site Cèdres, behind the Restaurant no. 1. - From 9:30 hrs, discussions and debates in the main auditorium. ... the Prévessin site on 25 September: - From 8:30 hrs, stands and demonstrations on the parking site of the building 866. - From 14:00 hrs, discussions and debates in the AB auditorium, building 864.

  12. Weather and road capacity

    DEFF Research Database (Denmark)

    Jensen, Thomas Christian

    2014-01-01

    The paper presents estimations of the effect of bad weather on the observed speed on a Danish highway section; Køge Bugt Motorvejen. The paper concludes that weather, primarily precipitation and snow, has a clear negative effect on speed when the road is not in hypercongestion mode. Furthermore......, the capacity of the highway seems to be reduced in bad weather and there are indications that travel time variability is also increased, at least in free-flow conditions. Heavy precipitation reduces speed and capacity by around 5-8%, whereas snow primarily reduces capacity. Other weather variables......-parametrically against traffic density and in step 2 the residuals from step 1 are regressed linearly against the weather variables. The choice of a non-parametric method is made to avoid constricting ties from a parametric specification and because the focus here is not on the relationship between traffic flow...

  13. 220kV站街变直流融冰装置试验及其应用%Test and application of DC deicing device in 220kV zhanjie substation

    Institute of Scientific and Technical Information of China (English)

    陈仕军; 杨通江; 陈峰; 张小兵

    2011-01-01

    DC - based deicing is the most efficient and reliable way to solve the problem of ice - accumulation of overhead line. As the DC deicing device is always on cold standby state, and come into operation when the overhead line is ice - accumulated, in order to ensuring the DC deicing device working normally during the ice - accumulating and the transmission line working safely and reliably dur- ing the ice disaster, we need to check the deicing device and carry out the low- voltage rectifier test periodically. Through inspecting the thyristor and the secondary system devices condition, the DC deicing device will enter the spinning reserve before the ice - accumulation in order to guaranteeing the safety and stability operation of the transmission line during the ice disaster.%直流融冰是解决架空导线覆冰是最直接、最有效、最可靠的融冰方式之一,但由于直流融冰装置只在线路覆冰期间投入运行,大部分时间都处于冷备用状态。为保证直流融冰装置在线路覆冰期间能正常运行,须定期对直流融冰装置进行检查及低压整流试验,通过试验检查晶闸管、二次系统设备的工作状况,使直流融冰装置在覆冰季前进入热备用状态,保证输电线路在冰灾期间的安全稳定运行。

  14. Road and Street Centerlines - Five Year Road Program (Arcs)

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Volusia County Adopted 5-year road improvement program. An additional 5-years of planning information is also included; this information is not officially Adopted....

  15. SALT for Language Acquisition.

    Science.gov (United States)

    Bancroft, W. Jane

    1996-01-01

    Discusses Schuster's Suggestive-Accelerative Learning Techniques (SALT) Method, which combines Lozanov's Suggestopedia with such American methods as Asher's Total Physical Response and Galyean's Confluent Education. The article argues that students trained with the SALT Method have higher achievement scores and better attitudes than others. (14…

  16. Hydroxycarboxylic acids and salts

    Energy Technology Data Exchange (ETDEWEB)

    Kiely, Donald E; Hash, Kirk R; Kramer-Presta, Kylie; Smith, Tyler N

    2015-02-24

    Compositions which inhibit corrosion and alter the physical properties of concrete (admixtures) are prepared from salt mixtures of hydroxycarboxylic acids, carboxylic acids, and nitric acid. The salt mixtures are prepared by neutralizing acid product mixtures from the oxidation of polyols using nitric acid and oxygen as the oxidizing agents. Nitric acid is removed from the hydroxycarboxylic acids by evaporation and diffusion dialysis.

  17. SALT for Language Acquisition.

    Science.gov (United States)

    Bancroft, W. Jane

    1996-01-01

    Discusses Schuster's Suggestive-Accelerative Learning Techniques (SALT) Method, which combines Lozanov's Suggestopedia with such American methods as Asher's Total Physical Response and Galyean's Confluent Education. The article argues that students trained with the SALT Method have higher achievement scores and better attitudes than others. (14…

  18. Geomechanics of bedded salt

    Energy Technology Data Exchange (ETDEWEB)

    Serata, S.; Milnor, S.W.

    1979-06-08

    Creep data from the literature search is reinterpreted by SGI, resulting in a better understanding of the temperature and stress state dependence of the octahedral creep rate and the octahedral shear strength. The concept of a transition strength between the elastic and the plastic states is in agreement with the data. The elastic and rheological properties of salt are described, and a set of constitutive equations is presented. The dependence of material properties on parameters such as temperature is considered. Findings on the permeability of salt are summarized, and the in-situ behavior of openings in bedded salt is described based on extensive engineering experience. A stress measuring system utilizing a finite element computer code is discussed. Geological factors affecting the stability of salt openings are considered, and the Stress Control Technique for designing stable openings in bedded salt formations is explained.

  19. Salt Tolerance in Soybean

    Institute of Scientific and Technical Information of China (English)

    Tsui-Hung Phang; Guihua Shao; Hon-Ming Lam

    2008-01-01

    Soybean is an Important cash crop and its productivity is significantly hampered by salt stress. High salt Imposes negative impacts on growth, nodulation, agronomy traits, seed quality and quantity, and thus reduces the yield of soybean. To cope with salt stress, soybean has developed several tolerance mechanisms, including: (I) maintenance of ion homeostasis; (ii) adjustment in response to osmotic stress; (iii) restoration of osmotic balance; and (iv) other metabolic and structural adaptations. The regulatory network for abiotic stress responses in higher plants has been studied extensively in model plants such as Arabidopsis thaliana. Some homologous components involved in salt stress responses have been identified in soybean. In this review, we tried to integrate the relevant works on soybean and proposes a working model to descdbe Its salt stress responses at the molecular level.

  20. Salt and nephrolithiasis.

    Science.gov (United States)

    Ticinesi, Andrea; Nouvenne, Antonio; Maalouf, Naim M; Borghi, Loris; Meschi, Tiziana

    2016-01-01

    Dietary sodium chloride intake is nowadays globally known as one of the major threats for cardiovascular health. However, there is also important evidence that it may influence idiopathic calcium nephrolithiasis onset and recurrence. Higher salt intake has been associated with hypercalciuria and hypocitraturia, which are major risk factors for calcium stone formation. Dietary salt restriction can be an effective means for secondary prevention of nephrolithiasis as well. Thus in this paper, we review the complex relationship between salt and nephrolithiasis, pointing out the difference between dietary sodium and salt intake and the best methods to assess them, highlighting the main findings of epidemiologic, laboratory and intervention studies and focusing on open issues such as the role of dietary salt in secondary causes of nephrolithiasis.

  1. Road Network Selection Based on Road Hierarchical Structure Control

    Directory of Open Access Journals (Sweden)

    HE Haiwei

    2015-04-01

    Full Text Available A new road network selection method based on hierarchical structure is studied. Firstly, road network is built as strokes which are then classified into hierarchical collections according to the criteria of betweenness centrality value (BC value. Secondly, the hierarchical structure of the strokes is enhanced using structural characteristic identification technique. Thirdly, the importance calculation model was established according to the relationships among the hierarchical structure of the strokes. Finally, the importance values of strokes are got supported with the model's hierarchical calculation, and with which the road network is selected. Tests are done to verify the advantage of this method by comparing it with other common stroke-oriented methods using three kinds of typical road network data. Comparision of the results show that this method had few need to semantic data, and could eliminate the negative influence of edge strokes caused by the criteria of BC value well. So, it is better to maintain the global hierarchical structure of road network, and suitable to meet with the selection of various kinds of road network at the same time.

  2. Road Safety: The Vital but Neglected Subject.

    Science.gov (United States)

    Hollins, Patsy

    1989-01-01

    Teacher training students (N=153) in England were surveyed about road safety education. Attitudes of students about their preparation for teaching road safety, ways of integrating road safety into the primary and secondary curriculum, and obstacles to teaching road safety in schools are discussed. (IAH)

  3. 3D Scene Priors for Road Detection

    NARCIS (Netherlands)

    Alvarez, J.M.; Gevers, T.; Lopez, A.M.

    2010-01-01

    Vision-based road detection is important in different areas of computer vision such as autonomous driving, car collision warning and pedestrian crossing detection. However, current vision-based road detection methods are usually based on low-level features and they assume structured roads, road

  4. 3D Scene Priors for Road Detection

    NARCIS (Netherlands)

    J.M. Alvarez; T. Gevers; A.M. Lopez

    2010-01-01

    Vision-based road detection is important in different areas of computer vision such as autonomous driving, car collision warning and pedestrian crossing detection. However, current vision-based road detection methods are usually based on low-level features and they assume structured roads, road homo

  5. The Rauischholzhausen agenda for road ecology

    NARCIS (Netherlands)

    Roedenbeck, I.A.; Fahrig, L.; Findlay, C.S.; Houlahan, J.E.; Jaeger, J.A.G.; Klar, N.; Kramer-Schadt, S.; Grift, van der E.A.

    2007-01-01

    Despite the documented negative effects of roads on wildlife, ecological research on road effects has had comparatively little influence on road planning decisions. We argue that road research would have a larger impact if researchers carefully considered the relevance of the research questions addr

  6. 3D Scene Priors for Road Detection

    NARCIS (Netherlands)

    Alvarez, J.M.; Gevers, T.; Lopez, A.M.

    2010-01-01

    Vision-based road detection is important in different areas of computer vision such as autonomous driving, car collision warning and pedestrian crossing detection. However, current vision-based road detection methods are usually based on low-level features and they assume structured roads, road homo

  7. Measuring (un)safety of roads.

    NARCIS (Netherlands)

    2009-01-01

    Measuring the safety level of a road is difficult. First of all you have to know how many crashes have occurred on a road. Various units of measurement are used for this: the absolute number of crashes per road, the number of crashes per road length, and the number of crashes per distance travelled.

  8. Measuring (un)safety of roads.

    NARCIS (Netherlands)

    2009-01-01

    Measuring the safety level of a road is difficult. First of all you have to know how many crashes have occurred on a road. Various units of measurement are used for this: the absolute number of crashes per road, the number of crashes per road length, and the number of crashes per distance travelled.

  9. Wheel-Based Ice Sensors for Road Vehicles

    Science.gov (United States)

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

    2011-01-01

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

  10. The contribution of on-road studies of road user behaviour to improving road safety.

    Science.gov (United States)

    Lenné, Michael G

    2013-09-01

    For over 40 years transport safety researchers have been using methods of vehicle instrumentation to gain greater insights into the factors that contribute to road user crash risk and the associated crash factors. In the previous decade in particular the widespread availability of lower cost and more advanced methods of vehicle instrumentation and recording technologies are supporting the increasing number of on-road research studies worldwide. The design of these studies ranges from multi-method studies using instrumented test vehicles and defined driving routes, to field operational tests, through to much larger and more naturalistic studies. It is timely to assess the utility of these methods for studying the influences of driver characteristics and states, the design and operation of the road system, and the influences of in-vehicle technologies on behaviour and safety for various road user groups. This special issue considers the extent to which on-road studies using vehicle instrumentation have been used to advance knowledge across these areas of road safety research. The papers included in this issue illustrate how research using instrumented test vehicles continues to generate new knowledge, and how the larger scale United States and European naturalistic and field operational test studies are providing a wealth of data about road user behaviour in real traffic. This is balanced with a number of studies that present methodological developments in data collection and analysis methods that, while promising, need further validation. The use of on-road methods to accurately describe the behaviours occurring in everyday real-world conditions, to quantify risks for safety critical events, and an improved understanding of the factors that contribute to risk, clearly has huge potential to promote further road trauma reductions.

  11. How effective is road mitigation at reducing road-kill? A meta-analysis

    NARCIS (Netherlands)

    Rytwinski, Trina; Soanes, Kylie; Jaeger, Jochen A.G.; Fahrig, Lenore; Findlay, C.S.; Houlahan, Jeff; Ree, van der Rodney; Grift, van der Edgar A.

    2016-01-01

    Road traffic kills hundreds of millions of animals every year, posing a critical threat to the
    populations of many species. To address this problem there are more than forty types of
    road mitigation measures available that aim to reduce wildlife mortality on roads (road-kill).
    For road

  12. Impact of an adequate road environment on the safety of non-motorised road users

    CSIR Research Space (South Africa)

    Ribbens, H

    2008-01-01

    Full Text Available ) among these vulnerable road users (VRUs) have always been high and in 2004, they constituted about 41% i.e. 5 309 of the 12 727 road fatalities on South African roads. Non-motorised road users (NMRUs) comprise a variety of road users, mostly pedestrians...

  13. How effective is road mitigation at reducing road-kill? A meta-analysis

    NARCIS (Netherlands)

    Rytwinski, Trina; Soanes, Kylie; Jaeger, Jochen A.G.; Fahrig, Lenore; Findlay, C.S.; Houlahan, Jeff; Ree, van der Rodney; Grift, van der Edgar A.

    2016-01-01

    Road traffic kills hundreds of millions of animals every year, posing a critical threat to the
    populations of many species. To address this problem there are more than forty types of
    road mitigation measures available that aim to reduce wildlife mortality on roads (road-kill).
    For road p

  14. The Dilemma of Mountain Roads

    Science.gov (United States)

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

  15. Modeling road-cycling performance.

    Science.gov (United States)

    Olds, T S; Norton, K I; Lowe, E L; Olive, S; Reay, F; Ly, S

    1995-04-01

    This paper presents a complete set of equations for a "first principles" mathematical model of road-cycling performance, including corrections for the effect of winds, tire pressure and wheel radius, altitude, relative humidity, rotational kinetic energy, drafting, and changed drag. The relevant physiological, biophysical, and environmental variables were measured in 41 experienced cyclists completing a 26-km road time trial. The correlation between actual and predicted times was 0.89 (P road-cycling performance are maximal O2 consumption, fractional utilization of maximal O2 consumption, mechanical efficiency, and projected frontal area. The model is then applied to some practical problems in road cycling: the effect of drafting, the advantage of using smaller front wheels, the effects of added mass, the importance of rotational kinetic energy, the effect of changes in drag due to changes in bicycle configuration, the normalization of performances under different conditions, and the limits of human performance.

  16. DOT Basemap Roads - All Types

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data set contains roadway centerlines for roads found on the USGS 1:24,000 mapping series. Those roadways that are Interstate, Trunk Highway, or CSAH (county...

  17. Curry County E-911 Roads

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Line attributes denoting all street centerlines in Curry County. Dataset includes all centerlines for all county maintained roads, all state and federal highways,and...

  18. Road Weather and Connected Vehicles

    Science.gov (United States)

    Pisano, P.; Boyce, B. C.

    2015-12-01

    On average, there are over 5.8 M vehicle crashes each year of which 23% are weather-related. Weather-related crashes are defined as those crashes that occur in adverse weather or on slick pavement. The vast majority of weather-related crashes happen on wet pavement (74%) and during rainfall (46%). Connected vehicle technologies hold the promise to transform road-weather management by providing improved road weather data in real time with greater temporal and geographic accuracy. This will dramatically expand the amount of data that can be used to assess, forecast, and address the impacts that weather has on roads, vehicles, and travelers. The use of vehicle-based measurements of the road and surrounding atmosphere with other, more traditional weather data sources, and create road and atmospheric hazard products for a variety of users. The broad availability of road weather data from mobile sources will vastly improve the ability to detect and forecast weather and road conditions, and will provide the capability to manage road-weather response on specific roadway links. The RWMP is currently demonstrating how weather, road conditions, and related vehicle data can be used for decision making through an innovative Integrated Mobile Observations project. FHWA is partnering with 3 DOTs (MN, MI, & NV) to pilot these applications. One is a mobile alerts application called the Motorists Advisories and Warnings (MAW) and a maintenance decision support application. These applications blend traditional weather information (e.g., radar, surface stations) with mobile vehicle data (e.g., temperature, brake status, wiper status) to determine current weather conditions. These weather conditions, and other road-travel-relevant information, are provided to users via web and phone applications. The MAW provides nowcasts and short-term forecasts out to 24 hours while the EMDSS application can provide forecasts up to 72 hours in advance. The three DOTs have placed readers and external

  19. 一种配电网线路不停电融冰方法%A Non-outage De-icing Method of Distribution Lines

    Institute of Scientific and Technical Information of China (English)

    杨少杰; 高一波

    2016-01-01

    A non-outage de-icing method of distribution lines is proposed. By lowering operating voltage of the iced distribution lines and increasing the current of the iced lines, the ice is melted by heat. A pair of wide-range on-load tap changer transformers are connected in series with both terminals of the iced lines through switches. By adjustment of the two transformers, the operating voltage of the iced lines is lowered to ensure voltage stability at the load terminal. A simulation model of non-outage deicing system of distribution lines is established based on PSCAD platform to simulate and analyze line deicing under different operating condi-tions; besides, the various reactive power compensation schemes are compared to provide voltage support for lines. In the end, the application scenario of the scheme is expounded.%提出了一种配网线路不停电融冰的方法,通过降低配电网线路覆冰段的运行电压、增加覆冰段线路电流,以实现热力融冰。将2台大范围有载调压变压器通过开关装置串联接入线路覆冰段两端,通过这2台融冰变压器的协同调节降低线路覆冰段运行电压,并保证负荷端电压的稳定。基于PSCAD平台搭建了配电网线路不停电融冰系统仿真模型,对不同工况下的线路融冰运行情况进行了仿真分析,并对不同无功补偿方案进行对比分析,从而为线路提供电压支撑,最后给出了该方案的适用场合。

  20. Effects of road deicer (NaCl) and amphibian grazers on detritus processing in pond mesocosms.

    Science.gov (United States)

    Van Meter, Robin J; Swan, Christopher M; Trossen, Carrie A

    2012-10-01

    Road deicers have been identified as potential stressors in aquatic habitats throughout the United States, but we know little regarding associated impacts to ecosystem function. A critical component of ecosystem function that has not previously been evaluated with respect to freshwater salinization is the impact on organic matter breakdown. The purpose of this study was to evaluate cumulative effects of road deicers and tadpole grazers on leaf litter breakdown rate (g d(-1) ) and microbial respiration (mg O(2)  g leaf(-1) h(-1) ). To test this interaction, in May 2008 the authors added dry leaf litter (Quercus spp.) to forty 600-L pond mesocosms and inoculated each with algae and zooplankton. In a full-factorial design, they manipulated a realistic level of road salt (ambient or elevated at 645 mg L(-1) Cl(-) ) and tadpole (Hyla versicolor) presence or absence. The elevated chloride treatment reduced microbial respiration by 24% in the presence of tadpoles. The breakdown of leaf litter by tadpoles occurred 9.7% faster under ambient chloride conditions relative to the elevated chloride treatment. Results of the present study suggest that the microbial community is directly impacted by road deicers and heavy tadpole grazing under ambient conditions limits microbial capacity to process detritus. Road salts and tadpoles interact to limit microbial respiration, but to a lesser extent leaf mass loss rate, thereby potentially restricting energy flow from detrital sources in pond ecosystems.

  1. LOGISTICS FLOWS IN THE ROAD SECTOR

    OpenAIRE

    Tsarenkova, I. M.

    2007-01-01

    Logistical torrents in the system of road economy is consider and distinctive sings which evoke peculiarity his activity and specific quality, be formed. During execution of works on object reveal optimum direction of move road-structure technology, which transformaintion to transport logistical road-structure torrents. Elements of information torrents on micro level, which reflection demand to the condition car road and scheme of forming financial torrents in road complex are work out; offer...

  2. 2013 CERN Road Race

    CERN Multimedia

    Klaus Hanke

    2013-01-01

    The 2013 annual CERN Road Race will be held on Wednesday 18 September at 6.15 p.m.   The 5.5 km race takes place over 3 laps of a 1.8 km circuit in the West Area of the Meyrin site, and is open to everyone working at CERN and their families. There are runners of all speeds, with times ranging from under 17 to over 34 minutes, and the race is run on a handicap basis, by staggering the starting times so that (in theory) all runners finish together. Children (< 15 years) have their own race over 1 lap of 1.8 km. As usual, there will be a “best family” challenge (judged on best parent and best child). Trophies are awarded in the usual men’s, women’s and veterans’ categories, and there is a challenge for the best age/performance. Every adult will receive a souvenir prize, financed by a registration fee of 10 CHF. Children enter free (each child will receive a medal). More information, and the online entry form, can be found here.

  3. 2013 CERN Road Race

    CERN Document Server

    Klaus Hanke

    2013-01-01

    The 2013 edition of the annual CERN Road Race will be held on Wednesday 18 September at 18.15.   The 5.5 km race takes place over 3 laps of a 1.8 km circuit in the West Area of the Meyrin site, and is open to everyone working at CERN and their families. There are runners of all speeds, with times ranging from under 17 to over 34 minutes, and the race is run on a handicap basis, by staggering the starting times so that (in theory) all runners finish together. Children (< 15 years) have their own race over 1 lap of 1.8 km. As usual, there will be a “best family” challenge (judged on best parent + best child). Trophies are awarded in the usual men’s, women’s and veterans’ categories, and there is a challenge for the best age/performance. Every adult will receive a souvenir prize, financed by a registration fee of 10 CHF. Children enter free (each child will receive a medal). More information, and the online entry form, can be found at: htt...

  4. Tourist Assessment of Croatian Roads

    Directory of Open Access Journals (Sweden)

    Joso Vurdelja

    2012-10-01

    Full Text Available As environmentally clean industry and as the most significantworld industry regarding the number of employees and theimpact on the social and economic development of a countTy,tourism represents an extremely important social and economicbranch for Croatia.As a functional unit of the mutually interweaving socialand economic relations, tourism is a complex phenomenonwhose development depends on a number of compatible factorsout of which the transport infrastructure is considered to bethe most obvious and almost the most significant one, i.e. thefirst among the equal. This is primarily true for road traffic infrastructure,since road trai!Sportation of tourists by passengercars, buses and motorcycles accounts for more than 90 percentof the overall tourist journeys in Croatia.The topic of this paper is precisely, among other things, thetourist assessment of the Croatian road network by means ofthe so-called econometric model regarding the contribution ofa certain road route to the overall tourist traffic.Practical implementation of the elaborated problematicshould result in the improvement of road infrastructure eitherby constructing new motonvays and/or roads, or by reconstructionand/or modernisation of the existing traffic routes.

  5. Road rage victimization among adolescents.

    Science.gov (United States)

    Smart, Reginald G; Stoduto, Gina; Adlaf, Edward M; Mann, Robert E; Sharpley, Justin M

    2007-09-01

    Although much has been learned about road rage among adults, data on road rage experiences among adolescents has not been available previously. We examine the prevalence and demographic correlates of road rage victimization based on a population survey of Ontario students. Based on the 2005 Ontario Student Drug Use Survey, a self-administered survey of Ontario students in grades 7-12 (n = 7726), the contribution of demographic factors (gender, region, driver's license status, grade, overall marks) to three road rage victimization measures was examined with logistic regression analysis. Just over half of students (53.2%) had been victims of shouts, curses and rude gestures in the past year, 8.9% were threatened with damage to their vehicle or personal injury and 6.2% experienced an attempt or actual damage to their vehicle or personal injury. Logistic regression analyses revealed that being a victim of shouting was significantly related to region, driver's license status, and grade. Victimization by threats was significantly related to gender, driver's license, grade, and marks. Being a victim of attempts or actual vehicle damage or injury was significantly related to region, driver's license, and marks. This study provides the first indication of prevalence of road rage victimization among adolescents. Road rage victimization in its milder form is common, involving just over half of Ontario students in grades 7-12. About 1 in 10 students were threatened with vehicle damage or personal injury, and about 1 in 20 were victims of attempts or actual damage or injury.

  6. Test Operations Procedure (TOP) 01-1-065 Accelerated Corrosion Durability

    Science.gov (United States)

    2013-10-15

    as a general guide. This procedure is focused on metallic corrosion and does not accelerate Microbial Induced Corrosion (MIC) or degradation of non...metallic materials such as plastics or rubbers due to solar exposure or other causes of degradation besides what is identified in this procedure... concentration salt solutions that are present on roadways, typically from road deicing salts. The application includes exposure to fine mists from elevated

  7. Crushed Salt Constitutive Model

    Energy Technology Data Exchange (ETDEWEB)

    Callahan, G.D.

    1999-02-01

    The constitutive model used to describe the deformation of crushed salt is presented in this report. Two mechanisms -- dislocation creep and grain boundary diffusional pressure solution -- are combined to form the basis for the constitutive model governing the deformation of crushed salt. The constitutive model is generalized to represent three-dimensional states of stress. Upon complete consolidation, the crushed-salt model reproduces the Multimechanism Deformation (M-D) model typically used for the Waste Isolation Pilot Plant (WIPP) host geological formation salt. New shear consolidation tests are combined with an existing database that includes hydrostatic consolidation and shear consolidation tests conducted on WIPP and southeastern New Mexico salt. Nonlinear least-squares model fitting to the database produced two sets of material parameter values for the model -- one for the shear consolidation tests and one for a combination of the shear and hydrostatic consolidation tests. Using the parameter values determined from the fitted database, the constitutive model is validated against constant strain-rate tests. Shaft seal problems are analyzed to demonstrate model-predicted consolidation of the shaft seal crushed-salt component. Based on the fitting statistics, the ability of the model to predict the test data, and the ability of the model to predict load paths and test data outside of the fitted database, the model appears to capture the creep consolidation behavior of crushed salt reasonably well.

  8. Gases in molten salts

    CERN Document Server

    Tomkins, RPT

    1991-01-01

    This volume contains tabulated collections and critical evaluations of original data for the solubility of gases in molten salts, gathered from chemical literature through to the end of 1989. Within the volume, material is arranged according to the individual gas. The gases include hydrogen halides, inert gases, oxygen, nitrogen, hydrogen, carbon dioxide, water vapor and halogens. The molten salts consist of single salts, binary mixtures and multicomponent systems. Included also, is a special section on the solubility of gases in molten silicate systems, focussing on slags and fluxes.

  9. Reducing Moose-Vehicle Collisions through Salt Pool Removal and Displacement: an Agent-Based Modeling Approach

    Directory of Open Access Journals (Sweden)

    Paul D. Grosman

    2009-12-01

    Full Text Available Between 1990 and 2002, more than 200 moose-vehicle collisions occurred each year in Quebec, including about 50/yr in the Laurentides Wildlife Reserve. One cause is the presence of roadside salt pools that attract moose near roads in the spring and summer. Using the computer simulation technique of agent-based modeling, this study investigated whether salt pool removal and displacement, i.e., a compensatory salt pool set up 100 to 1500 m away from the road shoulder, would reduce the number of moose-vehicle collisions. Moose road crossings were used as a proxy measure. A GPS telemetry data set consisting of approximately 200,000 locations of 47 moose over 2 yr in the Laurentides Wildlife Reserve was used as an empirical basis for the model. Twelve moose were selected from this data set and programmed in the model to forage and travel in the study area. Five parameters with an additional application of stochasticity were used to determine moose movement between forest polygons. These included food quality; cover quality, i.e., protection from predators and thermal stress; proximity to salt pools; proximity to water; and slope. There was a significant reduction in road crossings when either all or two thirds of the roadside salt pools were removed, with and/or without salt pool displacement. With 100% salt pool removal, the reduction was greater (49% without compensatory salt pools than with them (18%. When two thirds of the salt pools were removed, the reduction was the same with and without compensatory salt pools (16%. Although moose-vehicle collisions are not a significant mortality factor for the moose population in the Laurentides Wildlife Reserve, in areas with higher road densities, hunting pressure, and/or predator densities it could mean the difference between a stable and a declining population, and salt pool removal could be part of a good mitigation plan to halt population declines. This model can be used, with improvements such as

  10. Vanuatu - HDM-4 Analysis of the Efate Ring Road and the Santo East Coast Road

    Data.gov (United States)

    Millennium Challenge Corporation — The Millennium Challenge Corporation (MCC) provided funds for the upgrade of two roads in Vanuatu. These were the Efate Ring Road and the Santo East Coast Road. Both...

  11. 特高压直流融冰方式控制策略及试验分析%Analysis of Control Strategy and Test for De-Icing Operation Mode of UHVDC Project

    Institute of Scientific and Technical Information of China (English)

    杨万开; 吴庆范; 庞广恒

    2015-01-01

    特高压直流输电工程融冰接线方式采用极 I 和极 II高端换流器并联接线运行方式。向(家坝)—上(海)和锦(屏)—苏(南)±800 kV直流工程融冰基本控制方式采用并联混合式多端直流输电系统(multi-terminal direct current, MTDC)控制策略,溪(洛渡左岸)—浙(江金华)±800 kV直流工程采用并联换流器电流裕度控制策略。分析特高压直流工程融冰方式控制保护原理和向上、锦苏以及溪浙工程融冰方式系统试验结果,并对融冰接线方式系统试验过程中发现的稳态运行直流电流略大于设定值、直流电流不能稳定运行等问题进行论述和分析,揭示产生问题的原因,提出解决方案,并在向上特高压直流输电工程融冰方式系统试验过程中得到验证。%De-icing connection of ultra high voltage DC (UHVDC) transmission project consists of Pole 1 and Pole 2 high-voltage converters in parallel connection. Hybrid parallel multi-terminal direct current (MTDC) control was used as de-icing mode control strategy for parallel converters of Xiangjiaba-Shanghai (abbr. XS) and Jinping-Sunan (abbr. JS) ±800 kV UHVDC projects, and current margin control was used as de-icing mode control strategy for parallel converters of Xiluodu Left bank to Jinhua of Zhejiang (abbr. XZ)±800 kV UHVDC project. De-icing mode control and protective principles are analyzed in this paper. De-icing mode test results were analyzed during XS, JS and XZ UHVDC system commissioning tests. During de-icing tests, DC current steady state operation value was slightly larger than setting value, DC current could not be stable. These technical problems were discussed in detail and their causes were analyzed. Solutions of above problems were presented and testified in XS UHVDC transmission project de-icing mode test.

  12. 基于传感器的飞机地面除冰模拟实验研究%Study on simulation experiment for aircraft ground deicing based on sensor

    Institute of Scientific and Technical Information of China (English)

    王立文; 赵亮; 陈斌

    2013-01-01

    飞机除冰是影响民航冬季安全运行的重要因素之一,为了优化飞机除冰液参数,设计了飞机地面除冰室外实验.在冬季室外条件下通过对结冰的模拟机体表面喷射加热的除冰液进行除冰,在除冰过程中对除冰液流量、除冰液温度进行控制,通过安装在机体上的温度传感器和光纤传感器得到飞机机体表面温度变化和冰层厚度变化情况.通过分析实验结果可得:在一定范围内,除冰液温度升高能有效提高除冰速率;除冰液流量增加也能提高除冰速率,但当除冰液流量超过一定值时,射流冲击成为除冰的主要动力.%Aircraft icing is one of the important factors that affect civil aviation safety in operation in winter.In order to optimize parameters of aircraft deicing fluid,aircraft ground deicing outdoor experiment is carried out.In winter outdoor conditions,aircraft deicing is operated by injecting heated deicing fluid to the aircraft surface.The temperature and the velocity of the flow must be changed regularly,and change of temperature and ice thickness can be detected by temperature sensor and fibre-optic sensor that are installed on the aircraft surface.By analyzing result of experiment,the conclusion is that,in certain range the temperature rise of deicing liquid increases apparently ice removal rate,but the jet impact force will be the main force of deicing when the velocity of flow exceeds certain value.

  13. Research of Aircraft Ground Deicing Operation Based on Non-cooperative Game Theory%飞机地面除冰运行的非合作博弈研究

    Institute of Scientific and Technical Information of China (English)

    邢志伟; 乔晓辉

    2011-01-01

    针对大型机场对优化除冰调度运行以减少航班延误的需求,以及各航空公司对有限除冰资源的无序竞争,结合非合作博弈理论,建立飞机除冰地面运行的非合作博弈模型,设计了除冰资源分配为浮动优先级算法,在MATLAB环境下,利用首都机场动态航班数据对算法进行了仿真验证.仿真结果表明,将设计的浮动优先级算法应用于飞机地面除冰运行中,机场离港航班的延误情况得到了明显缓解,且对现有的"先到先服务"除冰调度策略进行了优化,并保证了资源分配的公平性,为机场地面除冰运行提供了一种新的思路.%Aiming at the request of reducing aircraft delay by optimizing the deicing operation in hinge airports, and the disordered competition to the limited deicing resources among the airline companies, a non-cooperative game based aircraft ground deicing operation modeling was established. The floating-priority algorithm used for distributing deicing resources was provided. Based on the software MATLAB, the domestic departures data of Beijing Capital Airport was used for simulation experiments. Simulation results show that the delays of the leaving flights has been relieved clearly and the 'first come, first served' scheduling strategy has been optimized after using of the floating-priority algorithm in the aircraft ground deicing operation. The presented model and algorithm ensure the fairness of resource-allocation and provide a new way for aircraft ground deicing operation.

  14. Model Test Study on Deicing Vibration of Long Span Transmission Tower-line System%大跨越输电塔—线体系脱冰振动模型试验

    Institute of Scientific and Technical Information of China (English)

    刘春城; 沈磨群; 张莹; 祁西汉

    2013-01-01

    输电线路脱冰振动响应给电网的正常运行带来重大的安全隐患.为精确分析大跨越输电塔—线体系中导地线脱冰对铁塔造成的动力冲击响应,以晋东南—南阳—荆门1 000 kV特高压输变电工程中的黄河大跨越段为原型,对覆冰条件下五塔四档线塔—线体系模型的脱冰冲击响应进行了模拟试验,通过对比分析塔-线体系在不同脱冰工况下杆塔的动力响应,获得输电杆塔的最不利脱冰工况,找出了输电塔在脱冰冲击作用下的最不利位置.利用ANSYS软件建立与试验模型相应的输电塔线体系模型,采用完全法瞬时动力分析模拟导、地线脱冰,提取各个测点应变,所得结果与试验结果吻合.%The deicing vibration of transmission tower-line system bring significant security risk to the normal operation of power network.In order to accurate study the dynamic shock response of long span transmission tower-line system deicing on the tower structure,taking the Yellow River long span transmission lines in Jindongnan-Nanyang-Jingmen 1 000 kV ultra high voltage (UHV) transmission project as prototype,deicing shock simulation test of transmission tower-line system is carried out to find out the dynamic response of tower structure under different icing conditions.By comparing and analyzing the dynamic response of tower structure on deicing,the most unfavorable on deicing conditions and position of tower is investigated.ANSYS software is used to establish the transmission tower-line system model corresponding to the test model.The full method transient dynamic analysis is applied to simulate conductor and grounding wires deicing and extract strain of each measure point.The result is consistent with the experiment.

  15. A Review of Electromagnetic Wave Absorbing Materials Used in Microwave Deicing Pavement%电磁波吸收材料用于微波融冰雪路面的研究进展∗

    Institute of Scientific and Technical Information of China (English)

    高杰; 张正伟; 韩振强; 沙爱民; 王振军; 蒋玮

    2016-01-01

    Microwave deicing pavement is manufactured by electromagnetic wave absorbing materials and the traditional pavement,which has broad application prospects because of its advantages of efficiency and eco-friendli-ness.In order to further increase the deicing ability of microwave deicing pavement,the working principle of the mi-crowave deicing pavement and the main factors influencing the deicing efficiency are introduced in this paper.Micro-wave heating mechanism of electromagnetic wave absorbing materials is elaborated.And the electromagnetic charac-teristics of 9 microwave absorbing materials are summarized.The research progresses of carbon fiber,magnetite and steel fiber in microwave deicing pavement are emphatically introduced,and their application prospects are evaluated re-spectively from the viewpoint of economic efficiency and heating rate .At last,the current drawbacks existing in this technology are pointed out.%电磁波吸收材料与传统路面材料相结合,所形成的微波融冰雪路面具有高效、环保等优势。为进一步提高路面的微波融冰雪能力,介绍了微波融冰雪路面的工作原理及影响除冰效率的主要因素,阐述了电磁波吸收材料在微波照射下的发热机理。在此基础上,综述了9种电磁波吸收材料的电磁特性,并着重介绍了碳纤维、磁铁矿石与钢纤维用于路面微波除冰雪的研究进展,并从发热速率与经济性角度对比分析其应用前景。最后,指出了目前研究中存在的问题,展望了今后的研究趋势。

  16. Serso - Seasonal storage of solar energy for the de-icing of a bridge; Serso, stockage saisonnier solaire pour le degivrage d'un pont

    Energy Technology Data Exchange (ETDEWEB)

    Pahud, D.

    2007-07-01

    This report for the Swiss Federal Office of Energy (SFOE) takes a look at a project that uses stored solar heat to de-ice a bridge. A concept is described which involves seasonal heat storage in the ground. Solar energy is collected during the summer, stored in the ground with the help of a borehole heat exchanger field, and recovered in winter for use in the defrosting of the bridge. Measurements of the system's thermal performance over a few years have been used to develop and validate a simulation tool for the sizing of similar systems. This simulation tool, called BRIDGESIM, is described and the various parameters used for particular situations are discussed. The effects of various factors such as the presence of ground water are discussed.

  17. Road safety and road traffic accidents in Saudi Arabia

    Science.gov (United States)

    Mansuri, Farah A.; Al-Zalabani, Abdulmohsen H.; Zalat, Marwa M.; Qabshawi, Reem I.

    2015-01-01

    Objectives: To identify the changing trends and crucial preventive approaches to road traffic accidents (RTAs) adopted in the Kingdom of Saudi Arabia (KSA) over the last 2.5 decades, and to analyze aspects previously overlooked. Methods: This systematic review was based on evidence of RTAs in KSA. All articles published during the last 25 years on road traffic accident in KSA were analyzed. This study was carried out from December 2013 to May 2014 in the Department of Family and Community Medicine, Taibah University, Al-Madinah Al-Munawwarah, KSA. Results: Road traffic accidents accounted for 83.4% of all trauma admissions in 1984-1989, and no such overall trend was studied thereafter. The most frequently injured body regions as reported in the latest studies were head and neck, followed by upper and lower extremities, which was found to be opposite to that of the studies reported earlier. Hospital data showed an 8% non-significant increase in road accident mortalities in contrast to police records of a 27% significant reduction during the years 2005-2010. Excessive speeding was the most common cause reported in all recent and past studies. Conclusion: Disparity was common in the type of reporting of RTAs, outcome measures, and possible causes over a period of 2.5 decade. All research exclusively looked into the drivers’ faults. A sentinel surveillance of road crashes should be kept in place in the secondary and tertiary care hospitals for all regions of KSA. PMID:25828277

  18. Chassis harness design for airport deicing vehicles%机场除冰车底盘部分线束设计研究

    Institute of Scientific and Technical Information of China (English)

    李剑涛; 唐岚; 杨桃; 唐伟

    2013-01-01

    The electric performance level of airport deicing vehicle directly affects its fuel economy, emission, and safety and comfort performance level. However, the quality of whole vehicle electric performance depends on vehicle's harness design level. This given design sets about airport deicing vehicle's chassis harness, investigates vehicle's harness elements design and drawing methods, which reduces defects from unreasonable design. Also, it uses graphics software to adjust its harness arrangement more reasonable. The real vehicle tests verified that this design improved the chassis harness performance of original airport vehicles. And this design provides a reference method for relevant professional designers.%机场除冰车整车电气性能水平直接影响其燃油经济性能、排放性能、安全及舒适性能的高低,而整车电气性能的优劣取决于汽车线束设计水平.该文从机场除冰车底盘部分线束的实际设计着手,对汽车线束中各要素设计及绘制方法进行研究,减少由设计不合理产生的缺陷,并运用绘图软件将其线束布置更为合理.经实车验证,该设计方法提升了原有机场专用车底盘线束性能,同时为相关专业设计人员提供了可借鉴的方法.

  19. Present a new type of self-heating composite based on carbon nanotubes paper and investigate the feasibility in deicing (presentation video)

    Science.gov (United States)

    Chu, Hetao; Zhang, Zhichun; Liu, Yanju; Leng, Jinsong

    2014-04-01

    In this paper, a novel self-heating composite material utilizing carbon nanotubes (CNTs) paper is designed and fabricated successfully. The carbon nanotube paper was prepared by multiple steps of CNTs dispersion and suspension filtration as shown in Fig1. a and characterized by scanning electron microscopy thermo gravimetric analysis nitrogen adsorption isotherms at 77K and so on. The surface of the as-prepared CNTs paper is smooth and very flexible. The conductivity of the CNTs paper could be regulated from 30 S/cm to 200 S/cm. The fabricating process of the self-heating is shown in Fig.1 b and the electric heating performance under different ambient temperature, power changing from 4.3W to 44.8W and wind speed ranging from 8m/s to 14m/s was discussed. In addition, the feasibility of the application in the deicing of the composite was simulated by the software of Fluent. The thermal behavior was discussed combining the experimental and simulated values, especially the temperature field distribution under different wind speed. The maximum heating rate can reach 2℃/s under different condition. The equilibrium temperature and energy consumption of the composite at different power compared with the commercial kanthal electric heating film were also investigated. The energy consumption of the self-heating material is less than the kanthal electric heating film to reach the same equilibrium temperature which may be caused by the difference of heat capacity. The experimental and simulated results indicate the electric heating performance of CNTs paper-based composite is superior to the commercial kanthal electric heating film and has feasibility in the field of deicing.

  20. Encapsulating Urban Traffic Rhythms into Road Networks

    Science.gov (United States)

    Wang, Junjie; Wei, Dong; He, Kun; Gong, Hang; Wang, Pu

    2014-02-01

    Using road GIS (geographical information systems) data and travel demand data for two U.S. urban areas, the dynamical driver sources of each road segment were located. A method to target road clusters closely related to urban traffic congestion was then developed to improve road network efficiency. The targeted road clusters show different spatial distributions at different times of a day, indicating that our method can encapsulate dynamical travel demand information into the road networks. As a proof of concept, when we lowered the speed limit or increased the capacity of road segments in the targeted road clusters, we found that both the number of congested roads and extra travel time were effectively reduced. In addition, the proposed modeling framework provided new insights on the optimization of transport efficiency in any infrastructure network with a specific supply and demand distribution.

  1. Salt Pomo: An Ethnogeography

    OpenAIRE

    McCarthy, Helen

    1986-01-01

    Recent research in Salt Pomo territory has produced new ethnogeographic data to add to the named villages identified in much earlier studies (Barrett 1904, 1908; Merriam MS, 1966, 1977). This new information is of particular interest because it significantly increases our general knowledge of the Salt Pomo, about whom little is otherwise known, and because it contributes to an understanding of their settlement pattern as well as to broader, regional land-use analyses. In addition, the study a...

  2. Hygroscopic Salts on Mars

    Science.gov (United States)

    Melchiorri, R.; Davila, A. F.; Chittenden, J.; Haberle, R. M.

    2008-12-01

    We present preliminary results on the influence of a salt-rich regolith in the water cycle of Mars. Global climate modeling shows that the relative humidity on the Martian surface often reaches values above the deliquescence point of salts that are common components of the regolith. At the deliquescence point, these salts will absorb atmospheric water vapor and form a saturated, transient liquid solution that is stable under a range of temperatures. If atmospheric temperatures fall below the eutectic point of the solution, the later will freeze in the pore space of the regolith, thereby resulting in a net transport of water from the vapor phase in the atmosphere, to the solid state in the regolith. This simple model partially accounts for some the distribution of water on the Martian surface as revealed by Mars Odyssey, in particular, we find that: even though the Cl and surface water distributions detected by HEND/ODYSSEY are highly correlated, salt deliquescence under the the present atmospheric conditions does not explain the overall distribution of water in the near surface regolith. However deliquescence of salt-rich soils could be an important contributor to the distribution of water in the regolith at high obliquity. In that scenario the water in the near-surface regolith would be the remnant of high obliquity conditions salt deliquescence is still active in different regions on Mars today, and it should be introduced as a parameter in the modern GCMs as a new ground/atmosphere interaction

  3. Road Nail: Experimental Solar Powered Intelligent Road Marking System

    Science.gov (United States)

    Samardžija, Dragan; Teslić, Nikola; Todorović, Branislav M.; Kovač, Erne; Isailović, Đorđe; Miladinović, Bojan

    2012-03-01

    Driving in low visibility conditions (night time, fog or heavy precipitation) is particularly challenging task with an increased probability of traffic accidents and possible injuries. Road Nail is a solar powered intelligent road marking system of wirelessly networked signaling devices that improve driver safety in low visibility conditions along hazardous roadways. Nails or signaling devices are autonomous nodes with capability to accumulate energy, exchange wireless messages, detect approaching vehicles and emit signalization light. We have built an experimental test-bed that consists of 20 nodes and a cellular gateway. Implementation details of the above system, including extensive measurements and performance evaluations in realistic field deployments are presented. A novel distributed network topology discovery scheme is proposed which integrates both sensor and wireless communication aspects, where nodes act autonomously. Finally, integration of the Road Nail system with the cellular network and the Internet is described.

  4. Accounting for anthropic energy flux of traffic in winter urban road surface temperature simulations with TEB model

    Directory of Open Access Journals (Sweden)

    A. Khalifa

    2015-06-01

    Full Text Available A forecast of the snowfall helps winter coordination operating services, reducing the cost of the maintenance actions, and the environmental impacts caused by an inappropriate use of de-icing. In order to determine the possible accumulation of snow on pavement, the forecast of the road surface temperature (RST is mandatory. Physical numerical models provide such forecast, and do need an accurate description of the infrastructure along with meteorological parameters. The objective of this study was to build a reliable urban RST forecast with a detailed integration of traffic in the Town Energy Balance (TEB numerical model for winter maintenance. The study first consisted in generating a physical and consistent description of traffic in the model with all the energy interactions, with two approaches to evaluate the traffic incidence on RST. Experiments were then conducted to measure the traffic effect on RST increase with respect to non circulated areas. These field data were then used for comparison with forecast provided by this traffic-implemented TEB version.

  5. The Application of Reconstructive SVC Device with Deicing Function in China Southern Power Grid%可重构SVC兼直流融冰装置在南方电网的应用

    Institute of Scientific and Technical Information of China (English)

    谢惠藩; 王海军; 张楠; 卢志良; 陈潜

    2012-01-01

    介绍了可重构SVC兼直流融冰装置在SVC模式及融冰模式下的控制策略和谐波特性,总结其在南方电网的应用情况,以500 kV桂林变电站和独山变电站的SVC项目为例讨论了实际运行的相关问题.%Introducing the control strategies and harmonic characteristics of reconstructive SVC device with deicing function in both SVC mode and deicing mode, this paper summarizes its application in China Southern Power Gird, and discusses the corresponding practical operation issues with the SVC projects in the 500 kV Guilin and Dushan substations as examples.

  6. Road characteristics and bicycle accidents.

    Science.gov (United States)

    Nyberg, P; Björnstig, U; Bygren, L O

    1996-12-01

    In Umeå, Sweden, defects in the physical road surface contributed to nearly half of the single bicycle accidents. The total social cost of these injuries to people amount to at least SEK 20 million (SEK 60,000 or about USD 8,500 per accident), which corresponds to the estimated loss of "eight life equivalents a year". Improved winter maintenance seems to have the greatest injury prevention potential and would probably reduce the number of injuries considerably, whereas improved road quality and modification of kerbs would reduce the most severe injuries. A local traffic safety program should try to prevent road accidents instead of handling the consequences of them. In accordance with Parliament decisions on traffic we would like to see increased investment in measures favoring bicycle traffic, where cycling is seen as a solution, not as a problem.

  7. PHOTOGRAMMETRIC TECHNIQUES FOR ROAD SURFACE ANALYSIS

    Directory of Open Access Journals (Sweden)

    V. A. Knyaz

    2016-06-01

    Full Text Available The quality and condition of a road surface is of great importance for convenience and safety of driving. So the investigations of the behaviour of road materials in laboratory conditions and monitoring of existing roads are widely fulfilled for controlling a geometric parameters and detecting defects in the road surface. Photogrammetry as accurate non-contact measuring method provides powerful means for solving different tasks in road surface reconstruction and analysis. The range of dimensions concerned in road surface analysis can have great variation from tenths of millimetre to hundreds meters and more. So a set of techniques is needed to meet all requirements of road parameters estimation. Two photogrammetric techniques for road surface analysis are presented: for accurate measuring of road pavement and for road surface reconstruction based on imagery obtained from unmanned aerial vehicle. The first technique uses photogrammetric system based on structured light for fast and accurate surface 3D reconstruction and it allows analysing the characteristics of road texture and monitoring the pavement behaviour. The second technique provides dense 3D model road suitable for road macro parameters estimation.

  8. A global strategy for road building.

    Science.gov (United States)

    Laurance, William F; Clements, Gopalasamy Reuben; Sloan, Sean; O'Connell, Christine S; Mueller, Nathan D; Goosem, Miriam; Venter, Oscar; Edwards, David P; Phalan, Ben; Balmford, Andrew; Van Der Ree, Rodney; Arrea, Irene Burgues

    2014-09-11

    The number and extent of roads will expand dramatically this century. Globally, at least 25 million kilometres of new roads are anticipated by 2050; a 60% increase in the total length of roads over that in 2010. Nine-tenths of all road construction is expected to occur in developing nations, including many regions that sustain exceptional biodiversity and vital ecosystem services. Roads penetrating into wilderness or frontier areas are a major proximate driver of habitat loss and fragmentation, wildfires, overhunting and other environmental degradation, often with irreversible impacts on ecosystems. Unfortunately, much road proliferation is chaotic or poorly planned, and the rate of expansion is so great that it often overwhelms the capacity of environmental planners and managers. Here we present a global scheme for prioritizing road building. This large-scale zoning plan seeks to limit the environmental costs of road expansion while maximizing its benefits for human development, by helping to increase agricultural production, which is an urgent priority given that global food demand could double by mid-century. Our analysis identifies areas with high environmental values where future road building should be avoided if possible, areas where strategic road improvements could promote agricultural development with relatively modest environmental costs, and 'conflict areas' where road building could have sizeable benefits for agriculture but with serious environmental damage. Our plan provides a template for proactively zoning and prioritizing roads during the most explosive era of road expansion in human history.

  9. Photogrammetric Techniques for Road Surface Analysis

    Science.gov (United States)

    Knyaz, V. A.; Chibunichev, A. G.

    2016-06-01

    The quality and condition of a road surface is of great importance for convenience and safety of driving. So the investigations of the behaviour of road materials in laboratory conditions and monitoring of existing roads are widely fulfilled for controlling a geometric parameters and detecting defects in the road surface. Photogrammetry as accurate non-contact measuring method provides powerful means for solving different tasks in road surface reconstruction and analysis. The range of dimensions concerned in road surface analysis can have great variation from tenths of millimetre to hundreds meters and more. So a set of techniques is needed to meet all requirements of road parameters estimation. Two photogrammetric techniques for road surface analysis are presented: for accurate measuring of road pavement and for road surface reconstruction based on imagery obtained from unmanned aerial vehicle. The first technique uses photogrammetric system based on structured light for fast and accurate surface 3D reconstruction and it allows analysing the characteristics of road texture and monitoring the pavement behaviour. The second technique provides dense 3D model road suitable for road macro parameters estimation.

  10. An analysis of Malaysia road traffic death distribution by road environment

    Indian Academy of Sciences (India)

    YUSRIA DARMA; MOHAMED REHAN KARIM; SULAIMAN ABDULLAH

    2017-09-01

    Various initiatives, strategies and programmes have been taken by the Government of Malaysia to resolve issues pertaining to road traffic deaths. Nevertheless, the implementation of the programmes outlined in Malaysian Road Safety Plan 2006 needs to be enhanced in order to achieve the set targets. In this regard, it is imperative for all parties concerning road safety to determine the factors that significantly contribute to road traffic deaths. According to the Ministry of Works, Malaysia, the blackspot treatment programme (which is centred on the elimination of road hazards by engineering approaches) is successful in reducing the number of injuries due to road traffic accidents up to a certain extent. This study is focussed on analysing road traffic deaths caused by various road environment elements recorded by the police from 2000 to 2011 in order to determine their distribution, proportion and relationship with fatal accidents. The Chi-square test and Marascuilo procedure with 5% level of significance are used in this study. Based on locality, the number of road traffic deaths in rural area (66%) is significantly higher compared with that in urban areas (34%). Based on road category, the number of road traffic deaths is the highest for federal roads, whereas the highest rate of fatalities per kilometre is recorded for expressways. Based on road segment, the number of road traffic deaths is the highest for straight road segments, followed by bends. In addition, the number of road traffic deaths is the highest for Y/T junctions,followed by cross junctions. The lowest number of road traffic deaths is recorded for interchanges and roundabouts. The results show that only 11.25% of the total road traffic deaths are related to road defects. The highest proportion of deaths due to road defects (48.6%) is associated with lack of street lighting provision,whereas road shoulder edge drop-off and potholes contribute 15.4% and 11.2% of road traffic deaths,respectively.

  11. Carbon Nanomaterials for Road Construction

    Directory of Open Access Journals (Sweden)

    Zaporotskova Irina Vladimirovna

    2015-05-01

    Full Text Available The requirement of developing and modernizing the roads in Russia and in the Volgograd region in particular, is based on need of expanding the directions of scientific research on road and transport complexes. They have to be aimed at the development of the theory of transport streams, traffic safety increase, and, first of all, at the application of original methods of road development and modernization, introduction of modern technologies and road-building materials.On the basis of the analysis of the plans for transportation sphere development in the Volgograd region assuming the need to apply the new technologies allowing to create qualitative paving, the authors propose the technology of creating a heavy-duty paving with the use of carbon nanomaterial. The knowledge on strengthening the characteristics of carbon nanotubes is a unique material for nanotechnology development which allowed to assume the analysis of general information about asphalt concrete. The analysis showed that carbon nanotubes can be used for improvement of operational characteristics of asphalt concrete, and it is possible to carry out additives of nanotubes in hot as well as in cold bitumen. The article contains the basic principles of creation of the new road material received by means of bitumen reinforcing by carbon nanotubes. The structures received by the offered technique binding on the basis of the bitumens modified by carbon nanomaterial can be used for coverings and bases on highways of all categories in all road and climatic zones of Russia. The technical result consists in increasing the durability and elasticity of the received asphalt covering, and also the increase of water resistance, heat resistance and frost resistance, the expansion of temperature range of its laying in the field of negative temperatures.

  12. Landscape Changes and a Salt Production Sustainable Approach in the State of Salt Pan Area Decreasing on the Coast of Tianjin, China

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2015-07-01

    Full Text Available Landsat images from 1979, 1988, 1999, 2008, and 2013 were used to analyze the landscape area change of salt pans lying on the coast of Tianjin. While initially (1979–1988, the area of Tianjin’s salt pan increased, later (1988–2013 it declined dramatically. In the first phase (1979–1988 of the studied period the primary roll-in landscape of the salt pan wasbarren land with an area of 60.0 km2. By 1988, the area of Tianjin’s salt pan rose to 457.8 km2. The main roll-out landscape of the salt pan during 1988–2013 was urban, barren land, village/town, harbor, and road whose area amounted to 69.8, 35.9, 27.3, 25.5 and 18.4 km2 respectively. The roll-out barren land will be transformed to construction land ultimately. By 2013, the total loss reached 167.3 km2, which was 36.5% of the salt pan area of Tianjin in 1988. With the development of coastal economy, the salterns with a lower economic value were transformed to and replaced by land use types with a higher economic value. This trend would influence the production of sea salt and the development of sodium hydroxide and sodium carbonate industries. Seawater desalination provides an opportunity for the restoration and compensation of salt production capacity. Based on the theory of circular economy and industrial symbiosis, in this article an industrial symbiosis model for sea salt production and sea water desalination is explored: “mariculture–power plant cooling–seawater desalination–Artemia culture–bromide extraction–sea salt production–salt chemical industry”. Through the application of this process sustainable development of the sea salt production in Tianjin could be achieved.

  13. Protocols for toll road systems

    OpenAIRE

    2013-01-01

    A problem in a tolling system like AutoPASS is the number of unidentified passages due to unreadable license plates. As a consequence money is lost for the toll road companies. A scheme is proposed that uses anonymous statistics to aid in the process of allocating resources for manual controls. Due to legal requirements for anonymity of data produced at toll plazas, a model that simulates the traffic frequencies on Norwegian roads is developed and implemented in Java. Using the toll plazas th...

  14. Research of the vertical swing arm device for a transmission line deicing robot%输电线路除冰机器人竖直摆臂机构研究

    Institute of Scientific and Technical Information of China (English)

    曹冲振; 庄佳兰; 王吉岱; 王凤芹; 梁程; 张玲玲

    2012-01-01

    研制除冰机器人代替人工方法进行导线除冰具有重要的应用前景.分析了除冰机器人前(后)臂运动特点,得到竖直摆臂机构的设计要求.根据竖直摆臂机构设计要求,采用四杆机构实现竖直摆臂运动.基于四杆机构的封闭性,应用解析法进行了四杆机构的机构综合,并用实例说明其应用.除冰机器人实验样机验证了四杆机构综合方法是正确的,四杆机构式竖直摆臂机构满足机器人的运动所有要求.%Deicing robot is more prospective than the manual in transmission line deicing.The design requirements of vertical swing arm device were got by analyzing motion characteristics of deicing robot fore arm (rear arm).According to motion requirements of the vertical swing arm device, a four-bar mechanism was adopted to achieve its swinging motion.Based on closeness of four-bar mechanism, a synthesis of vertical swing arm device was implemented by analyzing,and an example was used to explain its application. Deicing robot experimental prototype proved that the vertical swing arm device meet the motion require- ments of deicing robot.

  15. Salt treatment Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Stefan [NUKEM Technologies GmbH, Alzenau (Germany)

    2013-07-01

    The Task of NUKEM Technologies GmbH is to develop a technical solution for the treatment of salt containing effluents at Fukushima Daiichi. The target of the treatment is a solidified product suitable for the safe storage on site. Therefore, NUKEM investigated several technologies (direct cementation, drying and storage, drying and subsequent cementation) in order to find a fit for purpose solution. The following tasks have been considered: (a) Mechanical strength and homogeneity of the product; (b) Cost efficient solution (cost for the drying system vs. reduced amount of storage containers); (c) Proven technology; (d) On site storage. NUKEM made some practical test in parallel with different recipes. The aim was to embed as much as possible salt quantity into the cement matrix, but still meet the requested mechanical strength and required homogeneity. As a result NUKEM recommended to apply the following technologies (a) a drying system, to produce a dry salt product (b) a cementation facility, to generate a homogeneous salt/cement matrix (c) a filling station with attached CMS (Container measuring station) to fill the resulting cement/salt matrix into containers suitable for the storage at Fukushima Daiichi. (orig.)

  16. De Baca County E-911 Roads

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set contains a vector digital representation of all accessible roads including interstate highways, State highways, county roads and city streets in DeBaca...

  17. DNR State Forest Roads - WHEELS Database

    Data.gov (United States)

    Minnesota Department of Natural Resources — Roads administered by the Commissioner of Natural Resources to provide access to lands administered by the Division of Forestry. These roads are generally open to...

  18. Road safety audits: The way forward

    CSIR Research Space (South Africa)

    Labuschagne, FJJ

    2010-08-01

    Full Text Available formally implemented in South Africa. This paper assesses recent international developments pertaining to road safety auditing and reports on a review of the experience by road safety practitioners in South Africa. It concludes with recommendations...

  19. Honduras - Transportation and Farm to Market Roads

    Data.gov (United States)

    Millennium Challenge Corporation — The evaluation of the Transport Project and Farm to Market Roads Activity aimed to answer whether or not improved conditions throughout the road network: • Lowered...

  20. The angular nature of road networks

    CERN Document Server

    Molinero, Carlos; Arcaute, Elsa

    2015-01-01

    Road networks are characterised by several structural and geometric properties. Their topological structure determines partially its hierarchical arrangement, but since these are networks that are spatially situated and, therefore, spatially constrained, to fully understand the role that each road plays in the system it is fundamental to characterize the influence that geometrical properties have over the network's behaviour. In this work, we percolate the UK's road network using the relative angle between street segments as the occupation probability. We argue that road networks undergo a non-equilibrium first-order phase transition at the moment the main roads start to interconnect forming the spanning percolation cluster. The percolation process uncovers the hierarchical structure of the roads in the network, and as such, its classification. Furthermore, this technique serves to extract the set of most important roads of the network and to create a hierarchical index for each road in the system.

  1. 飞机除冰液加热系统单神经元PID控制仿真%Single Neuron PID Control Simulation of Aircraft Deicing Fluids Heating System

    Institute of Scientific and Technical Information of China (English)

    陈斌; 杨宏祯; 王立文

    2012-01-01

    Aiming at the temperature turbulence problem of aircraft deicing heating system, this paper presents the single neuron PID control strategy which combines the advantage of conventional PID control with artificial neuron control. By building the mathematical model of aircraft deicing fluids heating system on the basis of data gathered by experiments, simulation of single neuron PID control is executed. Results show that the single neuron PID control strategy performs effectively on the temperature turbulence problem of aircraft deicing fluids heating system.%针对在飞机除冰液加热系统中管路流量脉动造成温度波动的问题,提出单神经元PID控制策略,建立飞机除冰液加热系统的数学模型,并使用Matlab进行仿真.结果表明,单神经元PID控制策略对飞机除冰液加热过程的控制,比常规的PID控制器速率快、稳定性高.

  2. 架空输电线路除冰机器人的样机研制及动力学仿真%Development and Dynamics Simulation of De-icing Robot for Overhead Power Transmission Lines

    Institute of Scientific and Technical Information of China (English)

    张屹; 邵威; 朱大林; 邹圣权; 艾福洲; 朱险峰

    2011-01-01

    基于高压输电线路巡线机器人的研究,结合高压输电线路上覆冰的去除方法,设计了一种新型的高压输电线路除冰机器人.采用ADAMS软件对该机器人选行了运动学、动力学分析及仿真.结果表明,该机器人能在输电线上稳定地行走,并能较好地解决自主越障的问题,可完成输电线上的除冰任务.%Based on the research of power transmission lines inspection robot, a new robot for high voltage transmission lines deicing is designed by combination of transmission lines deicing method. Then, software ADAMS is applied to analyze and simulate the kinematies and dynamies of the robot. The results show that the robot can walk on transmission linen steadily and solve the problem of spanning barriers itself, which can complete deicing task of power transmission lines.

  3. Ranking EU progress on road safety : 10th road safety Performance Index (PIN) report.

    NARCIS (Netherlands)

    Adminaite, D. Jost, G. Stipdonk, H. & Ward, H.

    2016-01-01

    In 2010, the European Union renewed its commitment to improve road safety by setting a target of reducing road deaths by 50% by 2020, compared to 2010 levels. This target followed an earlier target set in 2001 to halve road deaths by 2010. 2015 was the second consecutive poor year for road safety; 2

  4. Tire-road noise: an experimental study of tire and road design parameters

    NARCIS (Netherlands)

    Bekke, Dirk; Wijnant, Ysbrand; Weegerink, Thijs; Boer, de Andre

    2013-01-01

    It is widely known that road traffic noise has negative influences on human health. Hence, as tire-road noise is considered to be the most dominant cause of road traffic noise above 30-50 km/h, a lot of research is performed by the two involving industries: road authorities/manufacturers and tire ma

  5. Tire-road noise: an experimental study of tire and road design parameters

    NARCIS (Netherlands)

    Bekke, Dirk; Wijnant, Ysbrand H.; Weegerink, Thijs; de Boer, Andries

    2013-01-01

    It is widely known that road traffic noise has negative influences on human health. Hence, as tire-road noise is considered to be the most dominant cause of road traffic noise above 30-50 km/h, a lot of research is performed by the two involving industries: road authorities/manufacturers and tire

  6. Trismus: An unusual presentation following road accident

    Directory of Open Access Journals (Sweden)

    Thakur Jagdeep

    2007-01-01

    Full Text Available Trismus due to trauma usually follows road accidents leading to massive faciomaxillary injury. In the literature there is no report of a foreign body causing trismus following a road accident, this rare case is an exception. We present a case of isolated presentation of trismus following a road accident. This case report stresses on the thorough evaluation of patients presenting with trismus following a road accident.

  7. Reflection properties of road surfaces. Contribution to OECD Scientific Expert Group AC4 on Road Surface Characteristics.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1983-01-01

    Photometric characteristics of road surfaces are dealt with. Representation of reflection properties in public lighting; quality criteria of road lighting installations; classification of road surfaces; the relation between reflection characteristics and other properties of road pavements in public

  8. Reflection properties of road surfaces. Contribution to OECD Scientific Expert Group AC4 on Road Surface Characteristics.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1983-01-01

    Photometric characteristics of road surfaces are dealt with. Representation of reflection properties in public lighting; quality criteria of road lighting installations; classification of road surfaces; the relation between reflection characteristics and other properties of road pavements in public

  9. Value of monitoring in road network management

    NARCIS (Netherlands)

    Zouch, M.; Courage, W.; Napoles-Morales, O.

    2014-01-01

    We present a framework for road network management to assist road authorities in maintenance budget estimations and long-term maintenance strategies definition. Information about road conditions is obtained from monitoring. Available data are used to estimate and update prediction of degradation evo

  10. Optimal Redesign of the Dutch Road Network

    NARCIS (Netherlands)

    Snelder, M.; Wagelmans, A.P.M.; Schrijver, J.M.; Van Zuylen, H.J.; Immers, L.H.

    2007-01-01

    The Dutch national road network has been developed over several decades. In the past, roads were constructed according to the then current spatial and transportation planning philosophies. Because the existing road network is a result of a long process of successive developments, the question can be

  11. Analysis of traffic safety at road works.

    NARCIS (Netherlands)

    Weijermars, W. & Spittje, H.

    2010-01-01

    Road works create a risk, both to road workers and drivers. SWOV conducted research into 58 severe crashes to gain more insight into the causes of crashes at work zones. Finally, 50 work-zones were visited to obtain more insight into (1) the extent to which the Dutch guidelines for safe road works a

  12. Psychological aspects of road user behaviour

    NARCIS (Netherlands)

    Rothengatter, J.A.

    1997-01-01

    The behaviour of road users is an important factor in accident causation. Traffic psychology, defined as ''the study of the behaviour of road users and the psychological processes underlying that behaviour'', attempts to identify the determinants of road user behaviour with the aim of developing eff

  13. Road geometry classification by adaptive shape models

    NARCIS (Netherlands)

    J.M. Álvarez; T. Gevers; F. Diego; A.M. López

    2012-01-01

    Vision-based road detection is important for different applications in transportation, such as autonomous driving, vehicle collision warning, and pedestrian crossing detection. Common approaches to road detection are based on low-level road appearance (e.g., color or texture) and neglect of the scen

  14. Psychological aspects of road user behaviour

    NARCIS (Netherlands)

    Rothengatter, J.A.

    The behaviour of road users is an important factor in accident causation. Traffic psychology, defined as ''the study of the behaviour of road users and the psychological processes underlying that behaviour'', attempts to identify the determinants of road user behaviour with the aim of developing

  15. Numerical simulation of tyre/road noise

    NARCIS (Netherlands)

    Schutte, Jan Henk

    2011-01-01

    In modern society, traffic noise has become an important issue for mental health. A significant contributor to this noise pollution is exterior tyre/road noise, which is caused by the interaction between tyre and road surface and. In order to reduce tyre/road noise at the source, accurate numerical

  16. Mechanism for salt scaling

    Science.gov (United States)

    Valenza, John J., II

    Salt scaling is superficial damage caused by freezing a saline solution on the surface of a cementitious body. The damage consists of the removal of small chips or flakes of binder. The discovery of this phenomenon in the early 1950's prompted hundreds of experimental studies, which clearly elucidated the characteristics of this damage. In particular it was shown that a pessimum salt concentration exists, where a moderate salt concentration (˜3%) results in the most damage. Despite the numerous studies, the mechanism responsible for salt scaling has not been identified. In this work it is shown that salt scaling is a result of the large thermal expansion mismatch between ice and the cementitious body, and that the mechanism responsible for damage is analogous to glue-spalling. When ice forms on a cementitious body a bi-material composite is formed. The thermal expansion coefficient of the ice is ˜5 times that of the underlying body, so when the temperature of the composite is lowered below the melting point, the ice goes into tension. Once this stress exceeds the strength of the ice, cracks initiate in the ice and propagate into the surface of the cementitious body, removing a flake of material. The glue-spall mechanism accounts for all of the characteristics of salt scaling. In particular, a theoretical analysis is presented which shows that the pessimum concentration is a consequence of the effect of brine pockets on the mechanical properties of ice, and that the damage morphology is accounted for by fracture mechanics. Finally, empirical evidence is presented that proves that the glue-small mechanism is the primary cause of salt scaling. The primary experimental tool used in this study is a novel warping experiment, where a pool of liquid is formed on top of a thin (˜3 mm) plate of cement paste. Stresses in the plate, including thermal expansion mismatch, result in warping of the plate, which is easily detected. This technique revealed the existence of

  17. Headway times and road safety.

    NARCIS (Netherlands)

    2007-01-01

    In road traffic, the advice is to maintain a minimum distance of two seconds to the vehicle in front. This headway time is based on the reaction time of drivers under various circumstances. A headway time of two seconds is sufficient for the majority of drivers to prevent a rear-end collision with

  18. Basics of a Good Road:

    OpenAIRE

    Bonte, Dudley

    2014-01-01

    This Asphalt 101 presentation will focus on the following topics: foundation preparation basics for a good road (subgrades, subgrade treatments, aggregate base; overlay preparation; and mixture thickness standards); what properties are critical to testing standards, quality, and inspection (materials, placement and compaction, use of INDOT specifications/certifications, APAI Local Government Specification Guide); and pavement preservation with 4.75 mm thin overlay.

  19. Distributed modeling for road authorities

    NARCIS (Netherlands)

    Luiten, G.T.; Bõhms, H.M.; Nederveen, S. van; Bektas, E.

    2013-01-01

    A great challenge for road authorities is to improve the effectiveness and efficiency of their core processes by improving data exchange and sharing using new technologies such as building information modeling (BIM). BIM has already been successfully implemented in other sectors, such as architectur

  20. Pollution-free road lighting

    Science.gov (United States)

    Schreuder, Duco A.

    They relate to reducing road accidents and some forms of crime but also enhance the social safety of residents and pedestrians and the amenity for residents. Road traffic in developing countries is much more hazardous than in industrialized countries. Accident rates in 'low' income countries may be as much as 35 times higher than in 'high' income countries. Thus, it might be much more cost-effective to light roads in the developing world than in the industrialized world. Fighting light pollution is more pressing in developing countries as most of the major high-class astronomical observatories are there. Astronomical observations are disturbed by light from outdoor lighting installations, part of which is scattered in the atmosphere to form 'sky glow'. The International Lighting Commission CIE has published a Technical Report giving general guidance for lighting designers and policy makers on the reduction of the sky glow. Lighting improves visibility, essential for almost all human activity. However, light that hits the road contributes to visibility only if it is reflected. In poorly designed lighting equipment much of the lumen output of the lamps is sent directly upwards. This can be avoided by properly defined light fittings. The light output of fittings is determined by their optical quality and by the installation maintenance factor. Open fittings are to be preferred. If mounted horizontally, they make street lighting with the least light pollution.

  1. Distributed modeling for road authorities

    NARCIS (Netherlands)

    Luiten, G.T.; Bõhms, H.M.; Nederveen, S. van; Bektas, E.

    2013-01-01

    A great challenge for road authorities is to improve the effectiveness and efficiency of their core processes by improving data exchange and sharing using new technologies such as building information modeling (BIM). BIM has already been successfully implemented in other sectors, such as architectur

  2. Road freight and the environment

    CSIR Research Space (South Africa)

    Makamo, N

    2015-07-01

    Full Text Available Freight transportation is one of the major contributors to economic development in a country. During a recent study, it was found that little information is available in terms of the cost of crashes to the environment. Environmental impacts of road...

  3. IN SPHERE OF ROAD BUILDING

    Directory of Open Access Journals (Sweden)

    Shakhov Oleg Fedorovich

    2012-09-01

    Full Text Available At present, it is necessary to use concession bases of development of national transport systems more widely considering the importance of road building, and also that fact that interests of the state and managing subjects - participants of investment building activity have differently directed vectors.

  4. Road Safety Barriers, the Need and Influence on Road Traffic Accidents

    Science.gov (United States)

    Butāns, Ž.; Gross, K. A.; Gridnevs, A.; Karzubova, E.

    2015-11-01

    Constantly increasing intensity of road traffic and the allowed speed limits seem to impose stronger requirements on road infrastructure and use of road safety systems. One of the ways to improve road safety is the use of road restraint systems. Road safety barriers allow not only reducing the number of road traffic accidents, but also lowering the severity of accidents. The paper provides information on the technical requirements of road safety barriers. Various types of road safety barriers and their selection criteria for different types of road sections are discussed. The article views an example of a road traffic accident, which is also modelled by PC-Crash computer program. The given example reflects a road accident mechanism in case of a car-to-barrier collision, and provides information about the typical damage to the car and the barrier. The paper describes an impact of the road safety barrier type and its presence on the road traffic accident mechanism. Implementation and maintenance costs of different barrier types are viewed. The article presents a discussion on the necessity to use road safety barriers, as well as their optimal choice.

  5. Photoluminescence of urine salts

    Science.gov (United States)

    Bordun, O.; Drobchak, O.

    2008-02-01

    Photoexcitation and luminescence spectra of dried urine sample under laser excitation were studied. Luminescence spectra of urine are determined by luminescence of urea which is the main component of urine. The presence of pathological salts in urine leads to the long-wave shifting of maxima of luminescence and to the decreasing of luminescence intensity.

  6. Learning SaltStack

    CERN Document Server

    Myers, Colton

    2015-01-01

    If you are a system administrator who manages multiple servers, then you know how difficult it is to keep your infrastructure in line. If you've been searching for an easier way, this book is for you. No prior experience with SaltStack is required.

  7. What Are Bath Salts?

    Science.gov (United States)

    ... in Missouri. She won the 3rd place 2013 Addiction Science Award . Read More » 0 Comments Bath Salts: An Emerging Danger February 05, 2013 / Sara Bellum ... copy Listen Drug Facts ... Nicotine, & E-Cigarettes Brain and Addiction Drug Overdoses in Youth HIV/AIDS and Drug ...

  8. Spatial Analysis Methods of Road Traffic Collisions

    DEFF Research Database (Denmark)

    Loo, Becky P. Y.; Anderson, Tessa Kate

    Spatial Analysis Methods of Road Traffic Collisions centers on the geographical nature of road crashes, and uses spatial methods to provide a greater understanding of the patterns and processes that cause them. Written by internationally known experts in the field of transport geography, the book...... outlines the key issues in identifying hazardous road locations (HRLs), considers current approaches used for reducing and preventing road traffic collisions, and outlines a strategy for improved road safety. The book covers spatial accuracy, validation, and other statistical issues, as well as link...

  9. Using CART to segment road images

    Science.gov (United States)

    Davies, Bob; Lienhart, Rainer

    2006-01-01

    The 2005 DARPA Grand Challenge is a 132 mile race through the desert with autonomous robotic vehicles. Lasers mounted on the car roof provide a map of the road up to 20 meters ahead of the car but the car needs to see further in order to go fast enough to win the race. Computer vision can extend that map of the road ahead but desert road is notoriously similar to the surrounding desert. The CART algorithm (Classification and Regression Trees) provided a machine learning boost to find road while at the same time measuring when that road could not be distinguished from surrounding desert.

  10. THE ECONOMIC EVALUATION OF FOREST ROAD BUILDING

    OpenAIRE

    Muška, Aina; Bičevskis, Matīss

    2010-01-01

    Forest road density in Latvia is insufficient, although the Joint Stock Company ‘‘Latvijas valsts meži” (“Latvian State Forestry”) performs active forest road building. The hypothesis of the research is that the resources invested in a forest road building pay off during its use. The goal of the research is to study the economic benefit from forest road building. The authors’ research showed that the total costs of forest road building and use could result in Ls 246,779 over 40 years or Ls 6,...

  11. Carpinteria Salt Marsh Habitat Polygons

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — We identified five common habitat types in Carpinteria Salt Marsh: channels, pans (flats), marsh, salt flat and upland. We then drew polygons around each habitat...

  12. 输电线路除冰机器人关键技术综述%Review on Key Technology of De-icing Robot Running on Overhead Transmission Line

    Institute of Scientific and Technical Information of China (English)

    王耀南; 魏书宁; 印峰; 杨易旻; 谭磊; 曹文明

    2011-01-01

    Ice-coated transmission lines seriously harm the safety and stability of the power grid. Compared with the traditional methods of de-icing, de-icing robots have advantages in terms of energy consumption, cost and safety, et al. As an emerging research area, international research on the de-icing robot is still in its infancy, and no mature technology can be used for reference. Thus it is necessary to review current achievements systematically and intensively. State-of-the-art in research and application of de-icing robot running on overhead transmission line are surveyed. Key technologies of de-icing robot are discussed in detail, including high reliability of motion mechanism design on complex flexible structure of transmission lines; autonomous behavior control and navigation in complex unstructured environment; efficient de-icing mechanism without damage; long-continuous power supply in a wide range of field work; remote communication, monitoring, teleoperation under the conditions of long distance and strong electromagnetic interference; special protection mechanisms under poor working conditions. Development trend and research direction for deicing robot are suggested in the end.%输电线路覆冰严重危害到电网的安全稳定运行,与传统除冰方法相比,采用机器人除冰在能耗、成本及安全性等方面具有优势.作为一个新兴的研究领域,国内外对除冰机器人的研究尚处在起步阶段,并没有成熟的技术可借鉴,因此有必要对现有研究成果进行系统分析和深入总结.回顾国内外高压输电线路除冰机器人的研究和应用现状,详细探讨了除冰机器人复杂柔性结构输电线缆上的高可靠性运动机构设计;复杂非结构化环境下的机器人自主行为控制与导航;无损伤高效除冰机构;野外大范围长时间工作的持续动力供给;远距离强电磁干扰条件下的机器人远程通信、监测和遥操作;恶劣工作环境中的本体

  13. Salt ingestion caves.

    Directory of Open Access Journals (Sweden)

    Lundquist Charles A.

    2006-01-01

    Full Text Available Large vertebrate herbivores, when they find a salt-bearing layer of rock, say in a cliff face, can produce sizable voids where, overgenerations, they have removed and consumed salty rock. The cavities formed by this natural animal process constitute a uniqueclass of caves that can be called salt ingestion caves. Several examples of such caves are described in various publications. Anexample in Mississippi U.S.A., Rock House Cave, was visited by the authors in 2000. It seems to have been formed by deer orbison. Perhaps the most spectacular example is Kitum Cave in Kenya. This cave has been excavated to a length over 100 metersby elephants. An ancient example is La Cueva del Milodon in Chile, which is reported to have been excavated by the now extinctmilodon, a giant ground sloth. Still other possible examples can be cited. This class of caves deserves a careful definition. First, thecavity in rock should meet the size and other conventions of the locally accepted definition of a cave. Of course this requirement differsin detail from country to country, particularly in the matter of size. The intent is to respect the local conventions. The characteristicthat human entry is possible is judged to be a crucial property of any recognized cave definition. Second, the cavity should besignificantly the result of vertebrate animal consumption of salt-bearing rock. The defining process is that rock removed to form thecave is carried away in the digestive track of an animal. While sodium salts are expected to be the norm, other salts for which thereis animal hunger are acceptable. Also some other speleogenesis process, such as solution, should not be excluded as long as it issecondary in formation of a cave in question.

  14. Road user behaviour changes following a self-explaining roads intervention.

    Science.gov (United States)

    Mackie, Hamish W; Charlton, Samuel G; Baas, Peter H; Villasenor, Pablo C

    2013-01-01

    The self-explaining roads (SER) approach uses road designs that evoke correct expectations and driving behaviours from road users to create a safe and user-friendly road network. Following the implementation of an SER process and retrofitting of local and collector roads in a suburb within Auckland City, lower speeds on local roads and less variation in speed on both local and collector roads were achieved, along with a closer match between actual and perceived safe speeds. Preliminary analyses of crash data shows that the project has resulted in a 30% reduction crash numbers and an 86% reduction in crash costs per annum, since the road changes were completed. In order to further understand the outcomes from this project, a study was carried out to measure the effects of the SER intervention on the activity and behaviour of all road users. Video was collected over nine separate days, at nine different locations, both before and after SER construction. Road user behaviour categories were developed for all potential road users at different location types and then used to code the video data. Following SER construction, on local roads there was a relatively higher proportion of pedestrians, less uniformity in vehicle lane keeping and less indicating by motorists along with less through traffic, reflecting a more informal/low speed local road environment. Pedestrians were less constrained on local roads following SER construction, possibly reflecting a perceptually safer and more user-friendly environment. These behaviours were not generally evident on collector roads, a trend also shown by the previous study of speed changes. Given that one of the objectives of SER is to match road user behaviour with functionally different road categories, the road user behaviour differences demonstrated on different road types within the SER trial area provides further reinforcement of a successful SER trial.

  15. FUNCTIONAL CLASSIFICATION OF RURAL ROADS IN SERBIA

    Directory of Open Access Journals (Sweden)

    Mihailo Maletin

    2015-06-01

    Full Text Available In order to revise the existing classification of rural roads in Serbia, which is rather old and defined on administrative criteria, the research developed a proposal for functional classification and categorization of primary rural roads. This resulted in four classes of rural roads based on their basic function and, with the introduction of five spatial accessibility levels, road classes are subdivided in eight road types. Based on the Serbia State Spatial Plan data, centers of gravitation together with border crossings are classified in four categories and desire lines of major transport function levels are defined. Based on this information and traffic count data the proposal of new primary rural road network in Serbia reduces the total length of the existing one with approximately the same overall accessibility level. Proposed categorization of rural roads as primary, regional and local ones is founded on functional classification and coincides with reorganization of governmental structure in Serbia.

  16. The safe road transport system approach

    Directory of Open Access Journals (Sweden)

    Vollpracht Hans-Joachim

    2016-07-01

    Full Text Available More than 1,24 million people die each year on the worlds roads and between 20 to 50 million suffer from nonfatal injuries. The UN Road Safety Collaboration Meetings under the leadership of WHO developed the Programme for the Decade of Actions for road safety taking nations into the responsibility of improving their accident figures by the five pillars of a national Road Safety Policy, safer Roads, safer Vehicles, safer Road Users and Post Crash Care. It is this Safe System Approach that takes into consideration the land use, infrastructure and transport planning, road user’s abilities and limitations and the close cooperation of all governmental and none governmental stakeholders involved.

  17. White noise excitation of road vehicle structures

    Indian Academy of Sciences (India)

    Werner Schiehlen

    2006-08-01

    Heave and pitch motions of road vehicle structures affect the comfort and the safety of passengers. Excitation of these vertical vibrations is due to road surface roughness. Road vehicle structures are modelled as mechanical systems characterized by their inertia, damping and stiffness, and represented as state equations. This paper deals with the influence of random road profiles on the vertical dynamics of road vehicles characterized by stochastic processes. Switching from road profile displacement to road profile velocity results in white noise excitation facilitating mathematical analysis. Some fundamentals of power spectral density analysis and covariance analysis are reviewed. A quarter car model is used to show the advantages of the covariance analysis resulting immediately in standard variations characterizing the vehicle’s performance.

  18. Understanding Road Usage Patterns in Urban Areas

    CERN Document Server

    Wang, Pu; Bayen, Alexandre M; Schechtner, Katja; González, Marta C; 10.1038/srep01001

    2012-01-01

    In this paper, we combine the most complete record of daily mobility, based on large-scale mobile phone data, with detailed Geographic Information System (GIS) data, uncovering previously hidden patterns in urban road usage. We find that the major usage of each road segment can be traced to its own - surprisingly few - driver sources. Based on this finding we propose a network of road usage by defining a bipartite network framework, demonstrating that in contrast to traditional approaches, which define road importance solely by topological measures, the role of a road segment depends on both: its betweeness and its degree in the road usage network. Moreover, our ability to pinpoint the few driver sources contributing to the major traffic flow allows us to create a strategy that achieves a significant reduction of the travel time across the entire road system, compared to a benchmark approach.

  19. Measuring Road Network Vulnerability with Sensitivity Analysis

    Science.gov (United States)

    Jun-qiang, Leng; Long-hai, Yang; Liu, Wei-yi; Zhao, Lin

    2017-01-01

    This paper focuses on the development of a method for road network vulnerability analysis, from the perspective of capacity degradation, which seeks to identify the critical infrastructures in the road network and the operational performance of the whole traffic system. This research involves defining the traffic utility index and modeling vulnerability of road segment, route, OD (Origin Destination) pair and road network. Meanwhile, sensitivity analysis method is utilized to calculate the change of traffic utility index due to capacity degradation. This method, compared to traditional traffic assignment, can improve calculation efficiency and make the application of vulnerability analysis to large actual road network possible. Finally, all the above models and calculation method is applied to actual road network evaluation to verify its efficiency and utility. This approach can be used as a decision-supporting tool for evaluating the performance of road network and identifying critical infrastructures in transportation planning and management, especially in the resource allocation for mitigation and recovery. PMID:28125706

  20. Salt fluoridation and oral health

    OpenAIRE

    Thomas M. Marthaler

    2013-01-01

    The aim of this paper is to make known the potential of fluoridated salt in community oral health programs, particularly in South Eastern Europe. Since 1922, the addition of iodine to salt has been successful in Switzerland. Goiter is virtually extinct. By 1945, the cariesprotective effect of fluorides was well established. Based on the success of water fluoridation, a gynecologist started adding of fluoride to salt. The sale of fluoridated salt began in 1956 in the Swiss Canton of Zurich,...

  1. 小型清雪除冰机的研究设计%Design and Research of Small Kiyoshi Deicing Machine

    Institute of Scientific and Technical Information of China (English)

    李晓建; 李彩霞; 袁磊; 曲帅帅

    2015-01-01

    At present, the snow removing job tasks in most domestic cities are mainly operated by labor or large machinery auxiliary operations, but the current situation that many streets in our country are too narrow to allow the operation of large ma-chinery, so we could only rely on manual operations to solve the dilemma.Small Kiyoshi deicing machine that is designed in this paper could effectively solve these difficulties.By combining the manual control and automatic control, the small Kiyoshi deicing operations can be carried out for different streets, which can effectively reduce the labor intensity, and can take advan-tage of its mechanized snow removal operations to effectively improve the efficiency.Small machinery is widely used in manu-facturing cost and application, and has good prospects for development and application value.%针对目前国内大部分城市除雪作业任务主要靠人工或大型机械设备辅助作业,但我国很多街道存在过窄的现状,限制了大型机械的操作,只能靠人工作业来解决目前面临的困境。小型清雪除冰机设计可有效地解决目前所面临的困境,它将人工控制与自动控制相结合,可以针对不同的街道进行清雪除冰作业,可有效地减轻工人的劳动强度,还可利用其机械化作业的优势有效地提高除雪效率。小型机械在制造成本与应用范围较广,能够大面积推广,具有较好的发展前景和应用价值。

  2. Design and Optimization of Electro-imlulse De-icing System Coil%电脉冲除冰系统线圈的设计及优化

    Institute of Scientific and Technical Information of China (English)

    王渊; 朱春玲; 付斌

    2016-01-01

    The impact force between the coil and the aluminum plate was studied.A numerical analysis was used for discharge process of electric impulse de-icing system from the point of view of energy transfer.The peak current and peak time coil inductance, capacitance and resistance, and other factors were taken into accaunt in cal-cution.A program was create to calculate the frequency, peak current, inductors and peak time for different coil parameters.Coil and aluminium were built two-dimensional finite element model to calculate the aluminum sheet electromagnetic and magnetic field distributions with the coil is loaded on the numerical calculation of current densi-ty.Electric impulse de-icing system was built experimental platform.Analysis of factors influencing the peak value of impact force.The impact force is analyzed and compared with the simulation results.An effective method for the design of the flat coil design is obtained.%对电脉冲除冰系统线圈和铝板之间产生冲击力进行研究。从能量传递的角度对系统放电过程进行数值计算,在计算峰值电流和峰值时间时考虑线圈感抗、电容容抗和导线电阻等因素。峰值电流计算结果导入二维有限元模型,通过改变线圈与铝板的参数对冲击力进行分析。搭建电脉冲除冰系统力学实验台,进行冲击力实验,分析影响冲击力峰值的因素。对所得冲击力进行分析并与仿真结果进行对比。得出一种有效的平板线圈设计优化方法。

  3. Lowering Salt in Your Diet

    Science.gov (United States)

    ... sodium, per serving. back to top Q. Are salt substitutes safe? A. Many salt substitutes contain potassium chloride and can be used by ... heart disease. Check with your doctor before using salt substitutes. back to top Q. What is FDA's role ...

  4. Effect of Road Lighting on the Quality of Dual Carriageway Road Service

    Directory of Open Access Journals (Sweden)

    Ben-Edigbe Johnnie

    2014-02-01

    Full Text Available The study is exciting because it introduced a new quality of road service assessment approach. The study explored the effect of road lighting on the quality of dual carriageway road service. Based on the hypothesis that road lighting has no significant effect on the level of road service, an impact study was carried out in Skudai town, Malaysia. Twenty four hours continuous traffic volume, vehicle types and speeds data were collected during daylight, road lighting and dry weather conditions for two directional flows. Results show that travel speeds speed during daylight and road lighting periods did not differ significantly. The study concluded road lighting does not affect the quality of road service significantly.

  5. Salt supply to and significance of asymmetric salt diapirs

    DEFF Research Database (Denmark)

    Koyi, H.; Burliga, S.; Chemia, Zurab

    2012-01-01

    Salt diapirs can be asymmetric both internally and externally reflecting their evolution history. As such, this asymmetry bear a significant amount of information about the differential loading (± lateral forces) and in turn the salt supply that have shaped the diapir. In two dimensions......, In this study we compare results of analogue and numerical models of diapirs with two natural salt diapris (Klodawa and Gorleben diapirs) to explain their salt supply and asymmetric evolution. In a NW-SE section, the Gorleben salt diapir possesses an asymmetric external geometry represented by a large...... southeastern overhang due to salt extrusion during Middle Cretaceous followed by its burial in Tertiary. This external asymmetry is also reflected in the internal configuration of the diapir which shows different rates of salt flow on the two halves of the structure. The asymmetric external and internal...

  6. Salt supply to and significance of asymmetric salt diapirs

    DEFF Research Database (Denmark)

    Koyi, H.; Burliga, S.; Chemia, Zurab

    2012-01-01

    Salt diapirs can be asymmetric both internally and externally reflecting their evolution history. As such, this asymmetry bear a significant amount of information about the differential loading (± lateral forces) and in turn the salt supply that have shaped the diapir. In two dimensions......, In this study we compare results of analogue and numerical models of diapirs with two natural salt diapris (Klodawa and Gorleben diapirs) to explain their salt supply and asymmetric evolution. In a NW-SE section, the Gorleben salt diapir possesses an asymmetric external geometry represented by a large...... southeastern overhang due to salt extrusion during Middle Cretaceous followed by its burial in Tertiary. This external asymmetry is also reflected in the internal configuration of the diapir which shows different rates of salt flow on the two halves of the structure. The asymmetric external and internal...

  7. Pairing Heterocyclic Cations with closo-dodecafluorododecaborate(2-). Synthesis of Binary Heterocyclium(1+) Salts and a AG4(heterocycle)8(4+) Salt of B12F12(2-) (Preprint)

    Science.gov (United States)

    2011-04-04

    Crystallographic data for salts 1-6, 8, and 9 have been deposited with the Cambridge Crystallographic Data Centre (deposition numbers CCDC XYZXYZ–XYZXYZ...Copies of the data can be obtained free of charge on application to CCDC , 12 Union Road, Cambridge CB2 1EZ, UK, fax: +44 1223 336033; email: deposit

  8. High-Luminance Road Surfaces,

    Science.gov (United States)

    1980-12-01

    condition was changed with the decreased use of snow chains and increasing use of studded tires. The studded tires wear down the road surface in a...region, white anorthosite of a uniform and unweathered type is usable as an additive to asphalt con- crete and wear surfacing for asphalt gravel...CLASSIFICATION Of THIS PAGE(W/em Daateoo 20. Abstract (cont’d) resistance to weathering, and the degree of luminosity. Quartzites have the best wear

  9. Appropriate roads for rural access

    CSIR Research Space (South Africa)

    Paige-Green, P

    2006-03-01

    Full Text Available plastic deformation. Deficiencies in any of these properties result in poor riding quality and high maintenance requirements as well as an increased loss of material from the road. It is thus essential that the best available material is used... of the specification illustrated in Figure 1 is the ability to identify potential problems associated with materials not meeting the specifications. This allows the implementer to make judgments regarding the consequences of using material outside...

  10. Methanol - alternative fuel road traffic

    Energy Technology Data Exchange (ETDEWEB)

    Muendler, H.

    1980-09-01

    This brochure names the fuel properties that are required for road traffic, discusses the replacement of petrol by methanol, discusses the possibilities of manufacturing methanol, draws up a timetable and an organigram for a (M-15) large scale test and compares costs of petrol, methanol, synthesis process petrol and hydrogenation process petrol. Furthermore, the technical requirements of vehicles as well as test results of exhaust gas emissions are also discussed.

  11. Mobility management and road safety.

    OpenAIRE

    2012-01-01

    Mobility management stands for organizing 'smart travel' and focuses on reducing the amount of car mobility (particularly during peak hours) by stimulating travellers to refrain from travelling (telecommuting), to travel at a different time of day (avoiding peak hours) or to choose a different means of transport. Mobility management should result in, for instance, improved accessibility and less environmental impact; road safety is hardly mentioned as an objective. Mobility management can inc...

  12. Revival of the Silk Road

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    China's Xinjiang Uygur Autonomous Region, bordering eight countries and providing a corridor to the Central Asian region, was once famous for the Silk Road. But now this region is often reported by Western media as having the problems of "political separatism, economic exclusion and religious fundamentalism." Professor David Gosset with the Shanghai-based China Europe International Business School analyzed Xinjiang's development, which he framed as "Xinjiang's experience." According to him, Xinjiang has ...

  13. Road safety: take it seriously

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    Around 50 road accidents happen every year at CERN. Cyclists, drivers and pedestrians must pay attention to their behaviour at all times to ensure that this doesn’t become an even more serious problem. Even if the Laboratory’s sites are not exactly downtown Shanghai, all road users need to make a little effort. So let’s do it!   Life at CERN: let’s stick to accumulating scientific data rather than road accidents! (Cartoon by Cian O'Luanaigh) Despite a dedicated Safety Code in force since 1990, “traffic-calming” measures put in place last year, several reminders in the Bulletin and frequent safety campaigns, the number of accidents, particularly those involving cyclists, has remained high since 2008. Luckily, no-one has been seriously injured but it is more and more frequent to experience near misses or actual accidents, whether in a car or on a bike. Incivilities, excessive speeding (also for bikes!) and answering ...

  14. Seismic risk assessment for road in Indonesia

    Science.gov (United States)

    Toyfur, Mona Foralisa; Pribadi, Krishna S.

    2016-05-01

    Road networks in Indonesia consist of 446,000 km of national, provincial and local roads as well as toll highways. Indonesia is one of countries that exposed to various natural hazards, such as earthquakes, floods, landslides, etc. Within the Indonesian archipelago, several global tectonic plates interact, such as the Indo-Australian, Pacific, Eurasian, resulting in a complex geological setting, characterized by the existence of seismically active faults and subduction zones and a chain of more than one hundred active volcanoes. Roads in Indonesia are vital infrastructure needed for people and goods movement, thus supporting community life and economic activities, including promoting regional economic development. Road damages and losses due to earthquakes have not been studied widely, whereas road disruption caused enormous economic damage. The aim of this research is to develop a method to analyse risk caused by seismic hazard to roads. The seismic risk level of road segment is defined using an earthquake risk index, adopting the method of Earthquake Disaster Risk Index model developed by Davidson (1997). Using this method, road segments' risk level can be defined and compared, and road risk map can be developed as a tool for prioritizing risk mitigation programs for road networks in Indonesia.

  15. Effects of road networks on bird populations.

    Science.gov (United States)

    Kociolek, A V; Clevenger, A P; St Clair, C C; Proppe, D S

    2011-04-01

    One potential contributor to the worldwide decline of bird populations is the increasing prevalence of roads, which have several negative effects on birds and other vertebrates. We synthesized the results of studies and reviews that explore the effects of roads on birds with an emphasis on paved roads. The well-known direct effects of roads on birds include habitat loss and fragmentation, vehicle-caused mortality, pollution, and poisoning. Nevertheless, indirect effects may exert a greater influence on bird populations. These effects include noise, artificial light, barriers to movement, and edges associated with roads. Moreover, indirect and direct effects may act synergistically to cause decreases in population density and species richness. Of the many effects of roads, it appears that road mortality and traffic noise may have the most substantial effects on birds relative to other effects and taxonomic groups. Potential measures for mitigating the detrimental effects of roads include noise-reduction strategies and changes to roadway lighting and vegetation and traffic flow. Road networks and traffic volumes are projected to increase in many countries around the world. Increasing habitat loss and fragmentation and predicted species distribution shifts due to climate change are likely to compound the overall effects of roads on birds.

  16. 75 FR 73983 - Proposed Modification of the Salt Lake City, UT, Class B Airspace Area; Public Meetings

    Science.gov (United States)

    2010-11-30

    ... Federal Aviation Administration 14 CFR Part 71 Proposed Modification of the Salt Lake City, UT, Class B... Lake City, UT. The purpose of these meetings is to provide interested parties an opportunity to present... held in the Ogden Conference Room, Ogden Hinckley Airport Terminal, 3909 Airport Road, Ogden, UT,...

  17. Frost formation with salt

    Science.gov (United States)

    Guadarrama-Cetina, J.; Mongruel, A.; González-Viñas, W.; Beysens, D.

    2015-06-01

    The formation of frost in presence of salt (NaCl) crystal is experimentally investigated on a hydrophobic surface. It presents several remarkable features due to the interplay of salty-water saturation pressure evolution, initially lower than the saturation pressure of ice and water, and the percolating propagation of ice dendrites from defects throughout the supercooled water droplet pattern. In particular, it is remarkable that nucleation of supercooled water and/or ice is prevented around the salty drop in a region of inhibited condensation where the substrate remains dry. As condensation proceeds, salt concentration decreases to eventually become lower than ice's, allowing ice dendrites to hit the salty drop. Salty water then melts ice but eventually freezes as an effect of dilution.

  18. Mixed salt crystallisation fouling

    CERN Document Server

    Helalizadeh, A

    2002-01-01

    The main purpose of this investigation was to study the mechanisms of mixed salt crystallisation fouling on heat transfer surfaces during convective heat transfer and sub-cooled flow boiling conditions. To-date no investigations on the effects of operating parameters on the deposition of mixtures of calcium sulphate and calcium carbonate, which are the most common constituents of scales formed on heat transfer surfaces, have been reported. As part of this research project, a substantial number of experiments were performed to determine the mechanisms controlling deposition. Fluid velocity, heat flux, surface and bulk temperatures, concentration of the solution, ionic strength, pressure and heat transfer surface material were varied systematically. After clarification of the effect of these parameters on the deposition process, the results of these experiments were used to develop a mechanistic model for prediction of fouling resistances, caused by crystallisation of mixed salts, under convective heat transfer...

  19. Thermochemical Properties of Nicotine Salts

    Directory of Open Access Journals (Sweden)

    Riggs DM

    2014-12-01

    Full Text Available The thermal gravimetric analysis (TGA and differential scanning calorimetry (DSC results presented in this report clearly show that the thermal stability and the endothermic peak nicotine release temperatures are different for different nicotine salts and these temperatures appear to be linked to the general microstructural details of the salt itself. In addition, the peak nicotine release temperatures are highly dependent upon the sample size used. The heat of vaporization for neat (non-protonated nicotine is also sample-size dependent. The TGA data showed that the least stable of the salts tested at elevated temperatures was the liquid salt nicotine triacetate followed by the crystalline materials (e.g., nicotine gallate and finally, the amorphous salts (e.g., nicotine alginate. The DSC results revealed that the liquid and crystalline salts exhibit nicotine release endotherms that are strongly related to the sample weight being tested. The amorphous salts show nicotine endotherm peak temperatures that are nearly independent of the sample weight. The range of peak nicotine release temperatures varied depending upon the specific salts and the sample size from 83 oC to well over 200 oC. Based on these results, the evolution of nicotine from the nicotine salt should be expected to vary based on the composition of the salt, the details of its microstructure, and the amount of nicotine salt tested.

  20. Frost formation with salt

    OpenAIRE

    Guadarrama-Cetina, J.; Mongruel, A; González-Viñas, W; Beysens, D. A.

    2015-01-01

    The formation of frost in presence of salt (NaCl) crystal is experimentally investigated on a hydrophobic surface. It presents several remarkable features due to the interplay of salty-water saturation pressure evolution, initially lower than the saturation pressure of ice and water, and the percolating propagation of ice dendrites from defects throughout the supercooled water droplet pattern. In particular, it is remarkable that nucleation of supercooled water and/or ice is prevented around ...

  1. A Robust Multifunctional Sandwich Panel Design with Trabecular Structures by the Use of Additive Manufacturing Technology for a New De-Icing System

    Directory of Open Access Journals (Sweden)

    Carlo Giovanni Ferro

    2017-06-01

    Full Text Available Anti-ice systems assure a vital on-board function in most aircraft: ice prevention or de-icing is mandatory for all aerodynamic surfaces to preserve their performance, and for all the movable surfaces to allow the proper control of the plane. In this work, a novel multi-functional panel concept which integrates anti-icing directly inside the primary structure is presented. In fact, constructing the core of the sandwich with trabecular non-stochastic cells allows the presence of a heat exchanger directly inside the structure with a savings in weight and an improvement in thermal efficiency. This solution can be realized easily in a single-piece component using Additive Manufacturing (AM technology without the need for joints, gluing, or welding. The objective of this study is to preliminarily investigate the mechanical properties of the core constructed with Selective Laser Melting (SLM; through the Design of Experiment (DOE, different design parameters were varied to understand how they affect the compression behaviour.

  2. 风电叶片除冰方法理论研究%A Theoretical Research on Deicing Technology for Wind Turbine Blades

    Institute of Scientific and Technical Information of China (English)

    陈阳; 薛浩鹏; 郝志勇

    2015-01-01

    With the deterioration of global ecological environment, clean and green energy has been developing quickly, especially the wind power energy. However, the problem of blade freezing in winter somehow restricts the development of wind power. A theoretical study was carried out on common deicing methods used at home and abroad,aiming to provide reference to future blade ice prevention technology.%随着地球生态环境日益恶化,清洁绿色能源得到了快速发展,储备丰富的风能发展尤为迅速.然而风机叶片冬季结冰问题很大程度上限制了风力发电的发展速度.根据目前国内外常用的除冰方法,从理论上进行学习研究,为以后更好地摸索风叶除冰技术打下坚实的基础.

  3. Invasive Brown Treesnake movements at road edges indicate road-crossing avoidance

    Science.gov (United States)

    Siers, Shane R; Savidge, Julie S; Reed, Robert N.

    2014-01-01

    Roads have significant impacts on the dispersal of wildlife. Although this poses a threat to the abundance and diversity of desirable flora and fauna, it also affords some opportunity for enhancing control of invasive species. Roads are the most common terrain features that may affect the rate of landscape-scale movements of invasive Brown Treesnakes (Boiga irregularis) throughout Guam. We radio tracked 45 free-ranging Brown Treesnakes in close proximity to two roads in Guam and recorded instances where daily relocations of snakes spanned roads. Then we reconstructed observed movement histories with randomized turning angles, which served as a useful null hypothesis for assessing the effect of roads or road edge habitat on Brown Treesnake movement patterns. Random walk simulations demonstrated that Brown Treesnakes crossed these roads at a rate far lower than would be expected if snake movement was random with respect to roads and road edge habitat. We discuss two alternative hypotheses for these results: 1) habitat gaps posed by roads physically or behaviorally restrict snake movement; or 2) road edges provide preferred foraging habitat from which snakes are reluctant to depart. Because roads often form the boundaries of jurisdictional and management units, the effects of roads on the movement of invasive Brown Treesnakes will influence the prospects for success of future landscape-level suppression efforts.

  4. Dynamics of vehicle-road coupled system

    CERN Document Server

    Yang, Shaopu; Li, Shaohua

    2015-01-01

    Vehicle dynamics and road dynamics are usually considered to be two largely independent subjects. In vehicle dynamics, road surface roughness is generally regarded as random excitation of the vehicle, while in road dynamics, the vehicle is generally regarded as a moving load acting on the pavement. This book suggests a new research concept to integrate the vehicle and the road system with the help of a tire model, and establishes a cross-subject research framework dubbed vehicle-pavement coupled system dynamics. In this context, the dynamics of the vehicle, road and the vehicle-road coupled system are investigated by means of theoretical analysis, numerical simulations and field tests. This book will be a valuable resource for university professors, graduate students and engineers majoring in automotive design, mechanical engineering, highway engineering and other related areas. Shaopu Yang is a professor and deputy president of Shijiazhuang Tiedao University, China; Liqun Chen is a professor at Shanghai Univ...

  5. Solid road environment and its hazards

    Directory of Open Access Journals (Sweden)

    Budzyński Marcin

    2017-01-01

    Full Text Available Accidents that involve vehicles departing the road tend to have very high severity, as they often result in the vehicle hitting a permanent obstacle (which can be a tree, a pole, facility pillar, front wall of a culvert or a barrier. In recent years, this type of accident caused approx. 19% of all road deaths in Poland. A particularly high risk can be observed on roads located in northern and western voivodships, with many avenues of trees along the roadside. The paper will present the major road user hazards and their locations, based on the example of detailed analyses conducted for the area of the Warminsko-Mazurskie voivodship in Poland. In the paper, the authors will also present measures that can be applied to improve the safety of road users by improving roads managed by local governments in Warminsko-Mazurskie.

  6. The road plan model: Information model for planning road building activities

    Science.gov (United States)

    Azinhal, Rafaela K.; Moura-Pires, Fernando

    1994-01-01

    The general building contractor is presented with an information model as an approach for deriving a high-level work plan of construction activities applied to road building. Road construction activities are represented in a Road Plan Model (RPM), which is modeled in the ISO standard STEP/EXPRESS and adopts various concepts from the GARM notation. The integration with the preceding road design stage and the succeeding phase of resource scheduling is discussed within the framework of a Road Construction Model. Construction knowledge is applied to the road design and the terrain model of the surrounding road infrastructure for the instantiation of the RPM. Issues regarding the implementation of a road planner application supporting the RPM are discussed.

  7. Road Lane Detection by Discriminating Dashed and Solid Road Lanes Using a Visible Light Camera Sensor

    National Research Council Canada - National Science Library

    Hoang, Toan Minh; Hong, Hyung Gil; Vokhidov, Husan; Park, Kang Ryoung

    2016-01-01

    With the increasing need for road lane detection used in lane departure warning systems and autonomous vehicles, many studies have been conducted to turn road lane detection into a virtual assistant...

  8. The Use of Theatre Tours in Road Safety Education.

    Science.gov (United States)

    Powney, Janet; And Others

    The Scottish Road Safety Campaign and the Road Safety Council of Wales have made a large investment in theater tours as a method of providing road safety education. This study aimed to evaluate the effectiveness of a road safety message delivered by a theater group, Road Safety Officers (RSOs), or, teachers for pupils in upper secondary classes.…

  9. Value creation of road infrastructure networks: a structural equation approach

    NARCIS (Netherlands)

    Hartmann, A.; Ling, F.Y.Y.

    2016-01-01

    Although road agencies need to provide road infrastructure that is beneficial for road users, little is known about how the activities of the agencies influence the value creation of road infrastructure. From a service-dominant logic perspective, the importance of road maintenance and traffic manage

  10. Road Network Generalization Based on Float CAR Tracking

    Science.gov (United States)

    Zhou, Cheng; Li, Wenjing; Jia, Hongguo

    2016-06-01

    Road generalization is not only helpful to simplify complicated road networks but can also satisfy the needs of reasonable display of roads under varying scales, thus offering basis for updating and grading urban roads. This paper proposes a selection method for road network generalization by integrating road-associated vehicle trajectory dynamic properties and road features and calculating the importance of urban roads. First of all, the location and motion information of floating vehicles are associated to relevant roads to generate the dynamic properties of roads. Then, the dynamic and static properties of roads are analyzed, and the cluster analysis is conducted to the trajectory points at road intersections to obtain the importance of some road intersections there are vehicles passing by. Afterwards, the weights of roads are calculated using the dominance rough set, the roads are ranked by weight and the practical significance of ranking results is analyzed. Finally, the selection rules for the basic framework of road network are determined to meet with different requirements and guarantee both connectivity and completeness of road networks. The results show that the relative importance of roads is made clear by taking advantage of the rough set and the generalized road network highlights the distribution and connection of urban main roads.

  11. Identification of Maximum Road Friction Coefficient and Optimal Slip Ratio Based on Road Type Recognition

    Institute of Scientific and Technical Information of China (English)

    GUAN Hsin; WANG Bo; LU Pingping; XU Liang

    2014-01-01

    The identification of maximum road friction coefficient and optimal slip ratio is crucial to vehicle dynamics and control. However, it is always not easy to identify the maximum road friction coefficient with high robustness and good adaptability to various vehicle operating conditions. The existing investigations on robust identification of maximum road friction coefficient are unsatisfactory. In this paper, an identification approach based on road type recognition is proposed for the robust identification of maximum road friction coefficient and optimal slip ratio. The instantaneous road friction coefficient is estimated through the recursive least square with a forgetting factor method based on the single wheel model, and the estimated road friction coefficient and slip ratio are grouped in a set of samples in a small time interval before the current time, which are updated with time progressing. The current road type is recognized by comparing the samples of the estimated road friction coefficient with the standard road friction coefficient of each typical road, and the minimum statistical error is used as the recognition principle to improve identification robustness. Once the road type is recognized, the maximum road friction coefficient and optimal slip ratio are determined. The numerical simulation tests are conducted on two typical road friction conditions(single-friction and joint-friction) by using CarSim software. The test results show that there is little identification error between the identified maximum road friction coefficient and the pre-set value in CarSim. The proposed identification method has good robustness performance to external disturbances and good adaptability to various vehicle operating conditions and road variations, and the identification results can be used for the adjustment of vehicle active safety control strategies.

  12. Contracting the Road to Development: Early Impacts of a Rural Roads Program

    OpenAIRE

    Martin Valdivia

    2010-01-01

    We study here the early impacts of the Peruvian Rural Roads Program (RRP), characterized by a decentralized mechanism that contracts private local firms for the rehabilitation and maintenance of rural roads with local supervision by community leaders setting incentives that favour prevention activities and a sustainable and timely maintenance of rural roads. The analysis is based on a quasi-experimental approach through which control roads are defined prior to the intervention and based on ke...

  13. Automatic Construction of Hierarchical Road Networks

    Science.gov (United States)

    Yang, Weiping

    2016-06-01

    This paper describes an automated method of constructing a hierarchical road network given a single dataset, without the presence of thematic attributes. The method is based on a pattern graph which maintains nodes and paths as junctions and through-traffic roads. The hierarchy is formed incrementally in a top-down fashion for highways, ramps, and major roads directly connected to ramps; and bottom-up for the rest of major and minor roads. Through reasoning and analysis, ramps are identified as unique characteristics for recognizing and assembling high speed roads. The method makes distinctions on the types of ramps by articulating their connection patterns with highways. Major and minor roads will be identified by both quantitative and qualitative analysis of spatial properties and by discovering neighbourhood patterns revealed in the data. The result of the method would enrich data description and support comprehensive queries on sorted exit or entry points on highways and their related roads. The enrichment on road network data is important to a high successful rate of feature matching for road networks and to geospatial data integration.

  14. THE GREAT SILK ROAD AND TURKISH WORLD

    Directory of Open Access Journals (Sweden)

    Mustafa ÖZDEMİR

    2011-04-01

    Full Text Available The expression of the great Silk Road first came from the famouse Chinese traveler Çjan Syan before the BC and is now known as Kervan Road. Later, this expression gained a new meaning between Asia, the Mediterranean and the European countries.An estimated of 20 000 km of total length of the Great Silk Road passed the Turkish peoples settled lands. The Silk Road that was considered as the Jugularvein major trade route that was connecting China and Byzantium was in Turks hands.

  15. Rheology of rock salt for salt tectonics modeling

    Directory of Open Access Journals (Sweden)

    Shi-Yuan Li

    2016-10-01

    Full Text Available Abstract Numerical modeling of salt tectonics is a rapidly evolving field; however, the constitutive equations to model long-term rock salt rheology in nature still remain controversial. Firstly, we built a database about the strain rate versus the differential stress through collecting the data from salt creep experiments at a range of temperatures (20–200 °C in laboratories. The aim is to collect data about salt deformation in nature, and the flow properties can be extracted from the data in laboratory experiments. Moreover, as an important preparation for salt tectonics modeling, a numerical model based on creep experiments of rock salt was developed in order to verify the specific model using the Abaqus package. Finally, under the condition of low differential stresses, the deformation mechanism would be extrapolated and discussed according to microstructure research. Since the studies of salt deformation in nature are the reliable extrapolation of laboratory data, we simplified the rock salt rheology to dislocation creep corresponding to power law creep (n = 5 with the appropriate material parameters in the salt tectonic modeling.

  16. The Effects of Vibrations Experienced during Road vs. Off-road Cycling.

    Science.gov (United States)

    Macdermid, P W; Fink, P W; Stannard, S R

    2015-10-01

    The purpose of this investigation was to compare the effects of vibrations experienced during off-road and road cycling. It was hypothesised that additional damping will be expressed through a greater work demand and increased physiological markers when travelling at the same speed over an identical terrain profile. Participants ascended a tar-sealed road climb and a single-track off-road climb at a predetermined speed. Time, speed, power, cadence, heart rate and V̇ O2 were sampled and logged every second while tri-axial accelerometers recorded accelerations (128 Hz) to quantify vibrations experienced. Statistical analysis indicated accelerations to be greater during the off-road condition (proad riding are associated with the increased vibrations and rolling resistance experienced. This led to increases in the work done (road: 280±69 vs. off-road: 312±74 W, p=0.0003) and, consequentially, a significant increase in the physiological markers V̇ O2 (road: 48.5±7.5 off-road 51.4±7.3 ml·kg(-1)·min(-1), p=0.0033) and heart rate (road: 161±10 off-road 170±10 bpm, p=0.0001) during the off-road condition. Such physiological differences and their causes are important to understand in order to provide suitable training recommendations or technological interventions for improving competitive performance or recreational enjoyment.

  17. RoADS: a road pavement monitoring system for anomaly detection using smart phones

    NARCIS (Netherlands)

    Seraj, Fatjon; Zwaag, van der Berend Jan; Dilo, Arta; Luarasi, Tamara; Havinga, Paul; Atzmueller, Martin; Chin, Alvin; Janssen, Frederik; Schweizer, Immanuel; Trattner, Christoph

    2016-01-01

    Monitoring the road pavement is a challenging task. Authorities spend time and finances to monitor the state and quality of the road pavement. This paper investigate road surface monitoring with smartphones equipped with GPS and inertial sensors: accelerometer and gyroscope. In this study we descri

  18. RoADS: a road pavement monitoring system for anomaly detection using smart phones

    NARCIS (Netherlands)

    Seraj, Fatjon; Zwaag, van der Berend Jan; Dilo, Arta; Luarasi, Tamara; Havinga, Paul

    2014-01-01

    Monitoring the road pavement is a challenging task. Authorities spend time and finances to monitor the state and quality of the road pavement. This paper investigate road surface monitoring with smartphones equipped with GPS and inertial sensors: accelerometer and gyroscope. In this study we describ

  19. The relationship between traffic volume and road safety on the secondary road network : a literature review.

    NARCIS (Netherlands)

    Duivenvoorden, K.

    2010-01-01

    On motorways, congestion is a well-known traffic problem. On the secondary road network, the same problem arises when traffic volume increases and the driven speed decreases. At certain times of day, roads get congested and the number of interactions between road users increases. In general, higher

  20. Visibility of road markings on wet road surfaces : a literature study.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1981-01-01

    The English version of B 14153 is presented. Road markings, notably lane markers, are often only poorly visible when the road is wet. This is particularly a problem at night on unlit roads. A study is made of whether a solution for this problem can be found on the basis of the known, published li

  1. Research on Transmission Line De-icing Source Based on the Method of High-frequency Excitation%基于高频激励法的输电线路融冰激励源研究

    Institute of Scientific and Technical Information of China (English)

    荆群伟; 周羽生; 罗屿; 刘亮

    2015-01-01

    针对当前输电线路融冰技术的缺陷,国外有学者提出了一种在线高频激励融冰方法。此方法具有可实现在线融冰、融冰电流小和融冰效率高等优点,但成套融冰设备未得到深入研究。为推进此融冰方法在输电线路中的实际应用,提出一种针对500 kV交流输电线路的移动式高频融冰激励源设计方案,重点分析并计算了移相变压器与功率单元相关参数,并运用MATLAB对级联式高频激励源进行仿真。结果表明,此方案可行且具有谐波含量低、输出电压稳定等优势。%Considering the current defects of transmission line melting ice technologies, some foreign scholars have proposed a new online high⁃frequency excitation method of melting ice which has the advantages of online deicing, small deicing current and high deicing efficiency;but the complete sets of equipment for deicing still need more re⁃search. To promote the practical application of this method in the power system, this paper proposes a portable high⁃frequency excitation design program used in 500 kV transmission line, and focuses on the analysis and calcu⁃lation of the phase⁃shifting transformers and power unit parameters. Then cascaded high⁃frequency excitation is sim⁃ulated with MATLAB. The results show that this scheme is feasible and has many advantages such as low harmonic contents and stable output voltage.

  2. Electrochromic Salts, Solutions, and Devices

    Energy Technology Data Exchange (ETDEWEB)

    Burrell, Anthony K. (Los Alamos, NM); Warner, Benjamin P. (Los Alamos, NM); McClesky, T. Mark (Los Alamos, NM)

    2008-11-11

    Electrochromic salts. Electrochromic salts of dicationic viologens such as methyl viologen and benzyl viologen associated with anions selected from bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and tris(trifluoromethylsulfonyl)methide are produced by metathesis with the corresponding viologen dihalide. They are highly soluble in molten quarternary ammonium salts and together with a suitable reductant provide electrolyte solutions that are used in electrochromic windows.

  3. Electrochromic Salts, Solutions, and Devices

    Energy Technology Data Exchange (ETDEWEB)

    Burrell, Anthony K. (Los Alamos, NM); Warner, Benjamin P. (Los Alamos, NM); McClesky, T. Mark (Los Alamos, NM)

    2008-10-14

    Electrochromic salts. Electrochromic salts of dicationic viologens such as methyl viologen and benzyl viologen associated with anions selected from bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and tris(trifluoromethylsulfonyl)methide are produced by metathesis with the corresponding viologen dihalide. They are highly soluble in molten quarternary ammonium salts and together with a suitable reductant provide electrolyte solutions that are used in electrochromic windows.

  4. Electrochromic salts, solutions, and devices

    Energy Technology Data Exchange (ETDEWEB)

    Burrell, Anthony K. (Los Alamos, NM); Warner, Benjamin P. (Los Alamos, NM); McClesky,7,064,212 T. Mark (Los Alamos, NM)

    2006-06-20

    Electrochromic salts. Electrochromic salts of dicationic viologens such as methyl viologen and benzyl viologen associated with anions selected from bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and tris(trifluoromethylsulfonyl)methide are produced by metathesis with the corresponding viologen dihalide. They are highly soluble in molten quarternary ammonium salts and together with a suitable reductant provide electrolyte solutions that are used in electrochromic windows.

  5. Salt fluoridation and oral health

    Directory of Open Access Journals (Sweden)

    Thomas M. Marthaler

    2013-11-01

    Full Text Available The aim of this paper is to make known the potential of fluoridated salt in community oral health programs, particularly in South Eastern Europe. Since 1922, the addition of iodine to salt has been successful in Switzerland. Goiter is virtually extinct. By 1945, the cariesprotective effect of fluorides was well established. Based on the success of water fluoridation, a gynecologist started adding of fluoride to salt. The sale of fluoridated salt began in 1956 in the Swiss Canton of Zurich, and several other cantons followed suit. Studies initiated in the early seventies showed that fluoride, when added to salt, inhibits dental caries. The addition of fluoride to salt for human consumption was officially authorized in 1980-82. In Switzerland 85% of domestic salt consumed is fluoridated and 67% in Germany. Salt fluoridation schemes are reaching more than one hundred million in Mexico, Colombia, Peru and Cuba. The cost of salt fluoridation is very low, within 0.02 and 0.05 € per year and capita. Children and adults of the low socio-economic strata tend to have substantially more untreated caries than higher strata. Salt fluoridation is by far the cheapest method for improving oral health. Conclusions. Salt fluoridation has cariostatic potential like water fluoridation (caries reductions up to 50%. In Europe, meaningful percentages of users have been attained only in Germany (67% and Switzerland (85%. In Latin America, there are more than 100 million users, and several countries have arrived at coverage of 90 to 99%. Salt fluoridation is by far the cheapest method of caries prevention, and billions of people throughout the world could benefit from this method.

  6. Forest opening with a secondary road network

    Directory of Open Access Journals (Sweden)

    Danilović Milorad

    2013-01-01

    Full Text Available This paper presents the results of an analysis of the position and density of a secondary road network in the group-selection management system. The research was conducted in the economic unit Prosara in the north west of the Republic of Srpska. The network of skid roads in the analyzed sections was recorded using the GPS devices Garmin GPS 60 and Garmin Map 62st, and the analysis software package used was ESRI ArcInfo 10.1. Adhering to the general guidelines, the slope of skid roads was analyzed within six predefined intervals: 0-12 %, 12-16 %, 16-20 %, 20-30 %, 30-40 % and over 40%. Relative openness with a secondary road network was determined for a maximum distance between the skid roads of 130m and it ranged from 82.62 % to 96.37 %. Such openness was classified as very good and excellent. Together with all factors related to stand and terrain characteristics, it appears that in all the compartments, the density of the secondary network of skid roads is adequate for the application of a skidder with a winch, without extending above the maximum length of the winch rope. Out of the total length of analyzed skid roads, 24% is within an appropriate slope interval for a planned conversion to truck roads, whereas 37 % is the maximum slope from the ecological point of view. The average terrain slope for the whole analyzed area is 26.4%. Such moderately sloping terrain is suitable for the construction of skid roads with low investment and small environmental impact. Due to their specific configuration, the main skid roads were designed along the ridge, while the secondary and tertiary skid roads most often separated from them at the maximum slope, forming an irregular fish bone shape.

  7. Scaling roads and wildlife: The Cinderella principle

    Science.gov (United States)

    Bissonette, J.A.

    2002-01-01

    It is clear that a reduction in both direct and indirect effects of roads and road networks must be the goal of management agencies. However, increased permeability of roaded landscapes can only be achieved by up-front planning and subsequent mitigative actions. The key is to understand that roads must be made permeable to the movement of animals. More profoundly, ecosystem services, i.e., clean water, clean air, uncontaminated soil, natural landscapes, recreation opportunities, abundant wildlife, and life sustaining ecological processes must not be seriously impacted. In other words, quality of life as measured by ecosystem services should be a major component of the planning process when roads are constructed or improved. Mitigative structures exist to increase permeability of roads. Wildlife overpasses and underpasses, often referred to as ecoducts or green bridges, with associated structures to enable larger animals to exit the road right of way, e.g., earthen escape ramps (BISSONETTE and HAMMER, 2001), various culvert designs for smaller animals including badger pipes and amphibian and reptile tunnels, and fish ladders are but a small sampling of the structures already in place around the world. What is needed is attention to the big picture. Landscapes need to be reconnected and made more permeable. Responsible agencies and organizations need to be aggressive about promoting mitigations and a conservation ethic into road planning. Only with a broad based effort between a concerned public, a database to work from, and a willingness of responsible agencies, will the now very large virtual footprint of roads and road networks be reduced to more closely approximate the physical footprint. By embracing the Cinderella Principle of making the virtual shoe fit more closely the actual physical footprint of roads, we will be able to achieve a closer connection with ecological harmony with its resultant effect of abundant wildlife.

  8. Tidal Flushing Restores the Physiological Condition of Fish Residing in Degraded Salt Marshes

    OpenAIRE

    Dibble, Kimberly L.; Meyerson, Laura A.

    2012-01-01

    Roads, bridges, and dikes constructed across salt marshes can restrict tidal flow, degrade habitat quality for nekton, and facilitate invasion by non-native plants including Phragmites australis. Introduced P. australis contributes to marsh accretion and eliminates marsh surface pools thereby adversely affecting fish by reducing access to intertidal habitats essential for feeding, reproduction, and refuge. Our study assessed the condition of resident fish populations (Fundulus heteroclitus) a...

  9. Pathophysiology of salt sensitivity hypertension.

    Science.gov (United States)

    Ando, Katsuyuki; Fujita, Toshiro

    2012-06-01

    Dietary salt intake is the most important factor contributing to hypertension, but the salt susceptibility of blood pressure (BP) is different in individual subjects. Although the pathogenesis of salt-sensitive hypertension is heterogeneous, it is mainly attributable to an impaired renal capacity to excrete sodium (Na(+) ). We recently identified two novel mechanisms that impair renal Na(+) -excreting function and result in an increase in BP. First, mineralocorticoid receptor (MR) activation in the kidney, which facilitates distal Na(+) reabsorption through epithelial Na(+) channel activation, causes salt-sensitive hypertension. This mechanism exists not only in models of high-aldosterone hypertension as seen in conditions of obesity or metabolic syndrome, but also in normal- or low-aldosterone type of salt-sensitive hypertension. In the latter, Rac1 activation by salt excess causes MR stimulation. Second, renospecific sympathoactivation may cause an increase in BP under conditions of salt excess. Renal beta2 adrenoceptor stimulation in the kidney leads to decreased transcription of the gene encoding WNK4, a negative regulator of Na(+) reabsorption through Na(+) -Cl (-) cotransporter in the distal convoluted tubules, resulting in salt-dependent hypertension. Abnormalities identified in these two pathways of Na(+) reabsorption in the distal nephron may present therapeutic targets for the treatment of salt-sensitive hypertension.

  10. Dietary Salt Intake and Hypertension

    Science.gov (United States)

    2014-01-01

    Over the past century, salt has been the subject of intense scientific research related to blood pressure elevation and cardiovascular mortalities. Moderate reduction of dietary salt intake is generally an effective measure to reduce blood pressure. However, recently some in the academic society and lay media dispute the benefits of salt restriction, pointing to inconsistent outcomes noted in some observational studies. A reduction in dietary salt from the current intake of 9-12 g/day to the recommended level of less than 5-6 g/day will have major beneficial effects on cardiovascular health along with major healthcare cost savings around the world. The World Health Organization (WHO) strongly recommended to reduce dietary salt intake as one of the top priority actions to tackle the global non-communicable disease crisis and has urged member nations to take action to reduce population wide dietary salt intake to decrease the number of deaths from hypertension, cardiovascular disease and stroke. However, some scientists still advocate the possibility of increased risk of CVD morbidity and mortality at extremes of low salt intake. Future research may inform the optimal sodium reduction strategies and intake targets for general populations. Until then, we have to continue to build consensus around the greatest benefits of salt reduction for CVD prevention, and dietary salt intake reduction strategies must remain at the top of the public health agenda. PMID:25061468

  11. Road Crashes in Addis Ababa, Ethiopia: Empirical Findings ...

    African Journals Online (AJOL)

    Generally, among other risk factors we assessed including road conditions and ... right of way to other vehicles were the leading risk factors for road crashes in the city. Key Words: Road Crash; Fatalities; Serious Injuries; Minor Injuries; Safety ...

  12. All roads lead to Meyrin

    CERN Multimedia

    Communication locale

    2011-01-01

    Tous les chemins mènent à Meyrin - All roads lead to Meyrin From 29 September to 16 October, 2011, come to the Salle Antoine Verchère in Meyrin for Tous les chemins mènent à Meyrin. The celebration will include an exposition as well as a theatrical performance about Meyrin, the first satellite city in Switzerland. With the help of the memories and testimonies from the people of Meyrin, Tous les chemins mènent à Meyrin is putting the collective memories of the commune on display. It is an occasion for everyone, whether you're from near or far, to find out how all the roads lead to Meyrin.  Salle Antoine-Verchère Route de Meyrin 294 – 1217 Meyrin Tram 18 – Stop: Meyrin Village Thursdays / Fridays / Saturdays at 8pm Sundays at 5pm Regular ticket: CHF 15.- Concession ticket (students, chômeurs, AVS, AI): CHF 12.- Children up to 16: CHF 10.- Family ticket: CHF 35.-

  13. Temporal contrast of salt delivery in mouth increases salt perception

    NARCIS (Netherlands)

    Busch, J.L.H.C.; Tournier, C.; Knoop, J.E.; Kooyman, G.; Smit, G.

    2009-01-01

    The impact of salt delivery in mouth on salt perception was investigated. It was hypothesized that fast concentration changes in the delivery to the receptor can reduce sensory adaptation, leading to an increased taste perception. Saltiness ratings were scored by a panel over time during various

  14. Road Scene Segmentation from a Single Image

    NARCIS (Netherlands)

    J.M. Alvarez; T. Gevers; Y. LeCun; A.M. Lopez

    2012-01-01

    Road scene segmentation is important in computer vision for different applications such as autonomous driving and pedestrian detection. Recovering the 3D structure of road scenes provides relevant contextual information to improve their understanding. In this paper, we use a convolutional neural net

  15. Drawing Road Networks with Mental Maps.

    Science.gov (United States)

    Lin, Shih-Syun; Lin, Chao-Hung; Hu, Yan-Jhang; Lee, Tong-Yee

    2014-09-01

    Tourist and destination maps are thematic maps designed to represent specific themes in maps. The road network topologies in these maps are generally more important than the geometric accuracy of roads. A road network warping method is proposed to facilitate map generation and improve theme representation in maps. The basic idea is deforming a road network to meet a user-specified mental map while an optimization process is performed to propagate distortions originating from road network warping. To generate a map, the proposed method includes algorithms for estimating road significance and for deforming a road network according to various geometric and aesthetic constraints. The proposed method can produce an iconic mark of a theme from a road network and meet a user-specified mental map. Therefore, the resulting map can serve as a tourist or destination map that not only provides visual aids for route planning and navigation tasks, but also visually emphasizes the presentation of a theme in a map for the purpose of advertising. In the experiments, the demonstrations of map generations show that our method enables map generation systems to generate deformed tourist and destination maps efficiently.

  16. Road safety: Knowledge, research and policy.

    NARCIS (Netherlands)

    Koornstra, M.J.

    1986-01-01

    The Dutch Institute for Road Safety Research SWOV is one of the very few institutes that is dedicated solely to the safety aspect of road traffic. In the nearly 25 years of its existence SWOV has contributed relatively much to the theoretical notions and methods of analysis. An overview is given of

  17. Road traffic emission monitoring on motorways

    NARCIS (Netherlands)

    Dittrich, M.G.; Beek, P.J.G. van

    2006-01-01

    Road traffic noise is one of the major environmental noise sources that is known to cause health problems. Despite existing noise reception items, the continuing growth of traffic causes higher levels than the lims allow. Consequently, excessive costs are incurred for noise barriers along roads and

  18. Off-Road and the Fragile Desert

    Science.gov (United States)

    Stebbins, Robert C.

    1974-01-01

    Part one of a two-part article sets forth the dimensions and the political-cultural aspects of the use of off-road vehicles in desert areas. Presents arguments for and against off-road vehicle use on national-resource land as exemplified in the California Desert. (Editor/JR)

  19. Ruts and waves in the road surface.

    NARCIS (Netherlands)

    Tromp, J.P.M.

    1989-01-01

    The characteristics of a road and a road surface should not unexpectedly change, if the traffic process is to be kept safe and under control. Knowledge on accidents, in which ruts and waves played a part does not seem to exist. Knowledge on driver behaviour due to the occurrence of waves or ruts is

  20. International comparability of road safety data.

    NARCIS (Netherlands)

    2007-01-01

    Many countries compare the level of their road safety with other countries as an impulse for developing road safety policy. This, however, is by no means easy. The absolute numbers of crashes or casualties can not simply be compared, but must be related to the number of inhabitants of a country or t