Study of electrostatically self-assembled thin films of CdS and ZnS nanoparticle semiconductors

NASA Astrophysics Data System (ADS)

Suryajaya

In this work, CdS and ZnS semiconducting colloid nanoparticles coated with organic shell, containing either SO[3-] or NH[2+] groups, were deposited as thin films using the technique of electrostatic self-assembly. The films produced were characterized with UV-vis spectroscopy and spectroscopic ellipsometry - for optical properties; atomic force microscopy (AFM) - for morphology study; mercury probe - for electrical characterisation; and photon counter - for electroluminescence study. UV-vis spectra show a substantial blue shift of the main absorption band of both CdS and ZnS, either in the form of solutions or films, with respect to the bulk materials. The calculation of nanoparticles' radii yields the value of about 1.8 nm for both CdS and ZnS.The fitting of standard ellipsometry data gave the thicknesses (d) of nanoparticle layers of around 5 nm for both CdS and ZnS which corresponds well to the size of particles evaluated from UV-vis spectral data if an additional thickness of the organic shell is taken into account. The values of refractive index (n) and extinction coefficient (k) obtained were about 2.28 and 0.7 at 633 nm wavelength, for both CdS and ZnS.Using total internal reflection (TIRE), the process of alternative deposition of poly-allylamine hydrochloride (PAH) and CdS (or ZnS) layers could be monitored in-situ. The dynamic scan shows that the adsorption kinetic of the first layer of PAH or nanoparticles was slower than that of the next layer. The fitting of TIRE spectra gavethicknesses of about 7 nm and 12 nm for CdS and ZnS, respectively. It supports the suggestion of the formation of three-dimensional aggregates of semiconductor nanoparticles intercalated with polyelectrolyte.AFM images show the formation of large aggregates of nanoparticles, about 40-50 nm, for the films deposited from original colloid solutions, while smaller aggregates, about 12-20 nm, were obtained if the colloid solutions were diluted.Current-voltage (I-V) and capacitance-frequency (C-f) measurements of polyelectrolyte/nanoparticles (CdS or ZnS) films suggest the tunnelling behaviour in the films while capacitance- voltage (C-V) and conductance-voltage (G-V) measurements suggest that these nanoparticles are conductive. The electroluminescence was detected in sandwich structures of (PAH/CdS/PAH)[N] using a photon counting detector, but not in the case of ZnS films.

Proceedings of Two Symposia on Nondestructive Testing of Tires

DTIC Science & Technology

1978-05-01

understanding of this tire inspection area. But this better technical understanding will not guar - antee the success of either the industry or...control. Tires with very dark sur- face may be sprayed with talcum powder to improve their reflectance. Depending upon tire type and the required tire...products there has been a tendency to use some natural or synthetic cross-linking polymer gums which under extended heat conditions have tended to

Feasibility of High-Resolution Pulse-Echo Techniques for Automobile Tire Inspection

DOT National Transportation Integrated Search

1973-06-01

The report presents ultrasonic A-scan reflection oscillograms and B-scan one-dimensional scanning displays for small sections of automobile tires, and for tire-like rubber and cord composite structures, using impulse excitation of 1-MHz and 5-MHz tra...

Optimization of an Optical Test Bench for Tire Properties Measurement and Tread Defects Characterization

PubMed Central

Castillo Aguilar, Juan Jesús; Cabrera Carrillo, Juan Antonio; Guerra Fernández, Antonio Jesús; Postigo Pozo, Sergio

2017-01-01

Tire characteristics and behavior are of great importance in vehicle dynamics since the forces transmitted in the tire-road contact are the main contributors to global vehicle performance. Several research groups have focused on the study and modeling of tires. Some of the most important factors that need to be known are tread characteristics and pressure distribution in the tire-ground contact patch. In this work, a test bench has been used to adequately determine the aforementioned factors. The measurement principle of the test bench is the frustration of total internal reflection (FTIR) of light. It makes use of a laterally illuminated glass on which the tire leans. An interposed plastic interface between them causes the reflection of light. Finally, a video camera captures the bright image formed through the glass. The brightness level in each pixel of the image is related to existing normal pressure. A study of the parameters that affect the test bench calibration such as type of interface material used, diffuse light, hysteresis, creep and transverse light absorption is performed. Experimental tests are conducted to relate tire inflation pressure and camber angle to the pressure distribution. Furthermore, the test bench is used to detect and evaluate the influence of defects in the tire on the contact pressures. PMID:28353674

Optimization of an Optical Test Bench for Tire Properties Measurement and Tread Defects Characterization.

PubMed

Castillo Aguilar, Juan Jesús; Cabrera Carrillo, Juan Antonio; Guerra Fernández, Antonio Jesús; Postigo Pozo, Sergio

2017-03-29

Tire characteristics and behavior are of great importance in vehicle dynamics since the forces transmitted in the tire-road contact are the main contributors to global vehicle performance. Several research groups have focused on the study and modeling of tires. Some of the most important factors that need to be known are tread characteristics and pressure distribution in the tire-ground contact patch. In this work, a test bench has been used to adequately determine the aforementioned factors. The measurement principle of the test bench is the frustration of total internal reflection (FTIR) of light. It makes use of a laterally illuminated glass on which the tire leans. An interposed plastic interface between them causes the reflection of light. Finally, a video camera captures the bright image formed through the glass. The brightness level in each pixel of the image is related to existing normal pressure. A study of the parameters that affect the test bench calibration such as type of interface material used, diffuse light, hysteresis, creep and transverse light absorption is performed. Experimental tests are conducted to relate tire inflation pressure and camber angle to the pressure distribution. Furthermore, the test bench is used to detect and evaluate the influence of defects in the tire on the contact pressures.

Mueller matrix spectroscopic ellipsometry study of chiral nanocrystalline cellulose films

NASA Astrophysics Data System (ADS)

Mendoza-Galván, Arturo; Muñoz-Pineda, Eloy; Ribeiro, Sidney J. L.; Santos, Moliria V.; Järrendahl, Kenneth; Arwin, Hans

2018-02-01

Chiral nanocrystalline cellulose (NCC) free-standing films were prepared through slow evaporation of aqueous suspensions of cellulose nanocrystals in a nematic chiral liquid crystal phase. Mueller matrix (MM) spectroscopic ellipsometry is used to study the polarization and depolarization properties of the chiral films. In the reflection mode, the MM is similar to the matrices reported for the cuticle of some beetles reflecting near circular left-handed polarized light in the visible range. The polarization properties of light transmitted at normal incidence for different polarization states of incident light are discussed. By using a differential decomposition of the MM, the structural circular birefringence and dichroism of a NCC chiral film are evaluated.

Immersion transmission ellipsometry (ITE): a new method for the precise determination of the 3D indicatrix of thin films

NASA Astrophysics Data System (ADS)

Jung, C. C.; Stumpe, J.

2005-02-01

The new method of immersion transmission ellipsometry (ITE) [1] has been developed. It allows the highly accurate determination of the absolute three-dimensional (3D) refractive indices of anisotropic thin films. The method is combined with conventional ellipsometry in transmission and reflection, and the thickness determination of anisotropic films solely by optical methods also becomes more accurate. The method is applied to the determination of the 3D refractive indices of thin spin-coated films of an azobenzene-containing liquid-crystalline copolymer. The development of the anisotropy in these films by photo-orientation and subsequent annealing is demonstrated. Depending on the annealing temperature, oblate or prolate orders are generated.

Ultrasonic Detection of Overbuffing in Retreaded Tires

DOT National Transportation Integrated Search

1977-08-01

A study was performed to determine the feasibility of nondestructive inspection by the reflection ultrasound for damage from overbuffing of retreaded tires. Following the introduction, the report briefly describes the principles of the method. Then, ...

Detecting Waste Tire Sites Using Satellite Imagery

NASA Astrophysics Data System (ADS)

Quinlan, B.; Huybrechts, C.; Schmidt, C.; Skiles, J. W.

2005-12-01

Waste tire piles pose environmental threats in the form of toxic fires and potential insect habitat. Previous techniques used to locate tire piles have included California Highway Patrol aerial surveillance and location tips from stakeholders. The TIRe (Tire Identification from Reflectance) model was developed as part of a pilot-project funded by the California Integrated Waste Management Board (CIWMB), a division of the California Environmental Protection Agency, and executed at NASA Ames Research Center's DEVELOP Program during the summer of 2005. The goal of the pilot-project was to determine if high-resolution satellite imagery could be used to locate waste tire disposal sites. The TIRe model, built in Leica Geosystems' ERDAS Imagine Model Builder, was created to automate the process of isolating tires in satellite imagery in two land cover types found in California. The sole geospatial data input to the TIRe model was Space Imaging IKONOS imagery. Once the imagery was processed through the TIRe model, less than 1% of the original image remained, consisting only of dark pixels containing tires or spectrally similar features. The output, a binary image was overlain on top of the original image for visual interpretation. The TIRe model was successfully able to identify waste tire piles as small as 400 tires and will prove to be a valuable tool for the detection, monitoring and remediation of waste tire sites.

Ellipsometry study of optical parameters of AgIn5S8 crystals

NASA Astrophysics Data System (ADS)

Isik, Mehmet; Gasanly, Nizami

2015-12-01

AgIn5S8 crystals grown by Bridgman method were characterized for optical properties by ellipsometry measurements. Spectral dependence of optical parameters; real and imaginary parts of the pseudodielectric function, pseudorefractive index, pseudoextinction coefficient, reflectivity and absorption coefficient were obtained from ellipsometry experiments carried out in the 1.2-6.2 eV range. Direct band gap energy of 1.84 eV was found from the analysis of absorption coefficient vs. photon energy. The oscillator energy, dispersion energy and zero-frequency refractive index, high-frequency dielectric constant values were found from the analysis of the experimental data using Wemple-DiDomenico and Spitzer-Fan models. Crystal structure and atomic composition ratio of the constituent elements in the AgIn5S8 crystal were revealed from structural characterization techniques of X-ray diffraction and energy dispersive spectroscopy.

Comparison null imaging ellipsometry using polarization rotator

NASA Astrophysics Data System (ADS)

Park, Sungmo; Kim, Eunsung; Kim, Jiwon; An, Ilsin

2018-05-01

In this study, two-reflection imaging ellipsometry is carried out to compare the changes in polarization states between two samples. By using a polarization rotator, the parallel and perpendicular components of polarization are easily switched between the two samples being compared. This leads to an intensity image consisting of null and off-null points depending on the difference in optical characteristics between the two samples. This technique does not require any movement of optical elements for nulling and can be used to detect defects or surface contamination for quality control of samples.

ELLIPSOMETRY OF ELECTROCHEMICAL SURFACE LAYERS

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

Muller, R.H.

1977-06-01

Ellipsometry is concerned with the analysis and interpretation of changes in the state of polarization caused by reflection. The technique has found increasing interest in recent years for the measurement of thin films because it is unusually sensitive, disturbs the object minimally and can be applied to surfaces contained in any optically transparent medium. Film thicknesses amenable to measurement range from fractional monoatomic coverage to microscopic thicknesses. The measurement of changes in the state of polarization of light due to reflection provides an unusually sensitive tool for observing surface layers in any optically transparent environment. A fast, self-compensating ellipsometer hasmore » been used to observe the electrochemical formation of reacted surface layers. The optical effect of mass-transport boundary layers and component imperfections have been taken into account in the interpretation of results.« less

Correlation Between Ultrasonic Nondestructive Inspection and Wheel Test of 34 Retreaded Tires

DOT National Transportation Integrated Search

1979-11-01

The report covers a test in which 34 retread tires were inspected using reflection ultrasound nondestructive inspection, wheel tested and then subjected to failure analysis by sectioning. The results demonstrate for the first time the ability of ultr...

Ellipsometry with polarisation analysis at cryogenic temperatures inside a vacuum chamber

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

Bauer, S.; Grees, B.; Spitzer, D.

2013-12-15

In this paper we describe a new variant of null ellipsometry to determine thicknesses and optical properties of thin films on a substrate at cryogenic temperatures. In the PCSA arrangement of ellipsometry the polarizer and the compensator are placed before the substrate and the analyzer after it. Usually, in the null ellipsometry the polarizer and the analyzer are rotated to find the searched minimum in intensity. In our variant we rotate the polarizer and the compensator instead, both being placed in the incoming beam before the substrate. Therefore the polarisation analysis of the reflected beam can be realized by anmore » analyzer at fixed orientation. We developed this method for investigations of thin cryogenic films inside a vacuum chamber where the analyzer and detector had to be placed inside the cold shield at a temperature of T≈ 90 K close to the substrate. All other optical components were installed at the incoming beam line outside the vacuum chamber, including all components which need to be rotated during the measurements. Our null ellipsometry variant has been tested with condensed krypton films on a highly oriented pyrolytic graphite substrate (HOPG) at a temperature of T≈ 25 K. We show that it is possible to determine the indices of refraction of condensed krypton and of the HOPG substrate as well as thickness of krypton films with reasonable accuracy.« less

Characterizing dielectric tensors of anisotropic materials from a single measurement

NASA Astrophysics Data System (ADS)

Smith, Paula Kay

Ellipsometry techniques look at changes in polarization states to measure optical properties of thin film materials. A beam reflected from a substrate measures the real and imaginary parts of the index of the material represented as n and k, respectively. Measuring the substrate at several angles gives additional information that can be used to measure multilayer thin film stacks. However, the outstanding problem in standard ellipsometry is that it uses a limited number of incident polarization states (s and p). This limits the technique to isotropic materials. The technique discussed in this paper extends the standard process to measure anisotropic materials by using a larger set of incident polarization states. By using a polarimeter to generate several incident polarization states and measure the polarization properties of the sample, ellipsometry can be performed on biaxial materials. Use of an optimization algorithm in conjunction with biaxial ellipsometry can more accurately determine the dielectric tensor of individual layers in multilayer structures. Biaxial ellipsometry is a technique that measures the dielectric tensors of a biaxial substrate, single-layer thin film, or multi-layer structure. The dielectric tensor of a biaxial material consists of the real and imaginary parts of the three orthogonal principal indices (n x + ikx, ny +iky and nz + i kz) as well as three Euler angles (alpha, beta and gamma) to describe its orientation. The method utilized in this work measures an angle-of-incidence Mueller matrix from a Mueller matrix imaging polarimeter equipped with a pair of microscope objectives that have low polarization properties. To accurately determine the dielectric tensors for multilayer samples, the angle-of-incidence Mueller matrix images are collected for multiple wavelengths. This is done in either a transmission mode or a reflection mode, each incorporates an appropriate dispersion model. Given approximate a priori knowledge of the dielectric tensor and film thickness, a Jones reflectivity matrix is calculated by solving Maxwell's equations at each surface. Converting the Jones matrix into a Mueller matrix provides a starting point for optimization. An optimization algorithm then finds the best fit dielectric tensor based on the measured angle-of-incidence Mueller matrix image. This process can be applied to polarizing materials, birefringent crystals and the multilayer structures of liquid crystal displays. In particular, the need for such accuracy in liquid crystal displays is growing as their applications in industry evolve.

The Structure of Self-Assembled Monolayers of Alkylsiloxanes on Silicon: A Comparison of Results from Ellipsometry and Low-Angle X-Ray Reflectivity

DTIC Science & Technology

1989-05-01

Thicknesses measured by the two methods differ by 2.2 (rlms) for alkyl chains of 10 - 18 carbon atoms and have a maximum difference of 4.2 e Ellipsometry...the approximate area projected by each alkyl group in the plane of the monolayer is 0,, 1’ ) # . Preliminary studies indicate that the use of this...projected by each alkyl group in the plane of the monolayer is - 21 ± 3 A2 . Preliminary studies indicate that this technique can be used to follow the

Ellipsometric studies of synthetic albumin-binding chitosan-derivatives and selected blood plasma proteins

NASA Astrophysics Data System (ADS)

Sarkar, Sabyasachi

This dissertation summarizes work on the synthesis of chitosan-derivatives and the development of ellipsometric methods to characterize materials of biological origin. Albumin-binding chitosan-derivatives were synthesized via addition reactions that involve amine groups naturally present in chitosan. These surfaces were shown to have an affinity towards human serum albumin via ELISA, UV spectroscopy and SDS PAGE. Modified surfaces were characterized with IR ellipsometry at various stages of their synthesis using appropriate optical models. It was found that spin cast chitosan films were anisotropic in nature. All optical models used for characterizing chitosan-derivatives were thus anisotropic. Chemical signal dependence on molecular structure and composition was illustrated via IR spectroscopic ellipsometry (IRSE). An anisotropic optical model of an ensemble of Lorentz oscillators were used to approximate material behavior. The presence of acetic acid in spin-cast non-neutralized chitosan samples was thus shown. IRSE application to biomaterials was also demonstrated by performing a step-wise chemical characterizations during synthesis stages. Protein adsorbed from single protein solutions on these modified surfaces was monitored by visible in-situ variable wavelength ellipsometry. Based on adsorption profiles obtained from single protein adsorption onto silicon surfaces, lumped parameter kinetic models were developed. These models were used to fit experimental data of immunoglobulin-G of different concentrations and approximate conformational changes in fibrinogen adsorption. Biomaterial characterization by ellipsometry was further extended to include characterization of individual protein solutions in the IR range. Proteins in an aqueous environment were characterized by attenuated total internal reflection (ATR) IR ellipsometry using a ZnSe prism. Parameterized dielectric functions were created for individual proteins using Lorentz oscillators. These parameterized dielectric functions were then used to describe the growth and eventual enzymatic degradation of a multilayered IgG structure by dynamic ATR-IR ellipsometry measurements. ATR-IR ellipsometry was also used to observe the specificity of anti-bodies to antigens.

Confinement effects on glass transition temperature, transition breadth, and expansivity: comparison of ellipsometry and fluorescence measurements on polystyrene films.

PubMed

Kim, S; Hewlett, S A; Roth, C B; Torkelson, J M

2009-09-01

Using ellipsometry, we characterized the nanoconfinement effect on the glass transition temperature (T (g)of supported polystyrene (PS) films employing two methods: the intersection of fits to the temperature (Tdependences of rubbery- and glassy-state thicknesses, and the transition mid-point between rubbery- and glassy-state expansivities. The results demonstrate a strong effect of thickness: T(g) (bulk) - T(g)(23 nm) = 10 degrees C. The T -range needed for accurate measurement increases significantly with decreasing thickness, an effect that arises from the broadening of the transition with confinement and a region below T (g) where expansivity slowly decreases with decreasing T . As determined from expansivities, the T (g) breadth triples in going from bulk films to a 21-nm-thick film; this broadening of the transition may be a more dramatic effect of confinement than the T (g) reduction itself. In contrast, there is little effect of confinement on the rubbery- and glassy-state expansivities. Compared with ellipsometry, T (g) 's from fluorescence agree well in bulk films but yield lower values in nanoconfined films: T (g)(bulk) - T (g)(23 nm) = 15( degrees ) C via fluorescence. This small difference in the T (g) confinement effect reflects differences in how fluorescence and ellipsometry report "average T (g) " with confinement. With decreasing nanoscale thickness, fluorescence may slightly overweight the contribution of the free-surface layer while ellipsometry may evenly weight or underweight its contribution.

Confinement effects on glass transition temperature, transition breadth, and expansivity: Comparison of ellipsometry and fluorescence measurements on polystyrene films

NASA Astrophysics Data System (ADS)

Kim, S.; Hewlett, S. A.; Roth, C. B.; Torkelson, J. M.

2009-09-01

Using ellipsometry, we characterized the nanoconfinement effect on the glass transition temperature (T gof supported polystyrene (PS) films employing two methods: the intersection of fits to the temperature (Tdependences of rubbery- and glassy-state thicknesses, and the transition mid-point between rubbery- and glassy-state expansivities. The results demonstrate a strong effect of thickness: ensuremath Tg(bulk)-Tg(23{ nm})= 10 circ C. The T -range needed for accurate measurement increases significantly with decreasing thickness, an effect that arises from the broadening of the transition with confinement and a region below T g where expansivity slowly decreases with decreasing T . As determined from expansivities, the T g breadth triples in going from bulk films to a 21-nm-thick film; this broadening of the transition may be a more dramatic effect of confinement than the T g reduction itself. In contrast, there is little effect of confinement on the rubbery- and glassy-state expansivities. Compared with ellipsometry, T g ’s from fluorescence agree well in bulk films but yield lower values in nanoconfined films: T g(bulk) - T g(23 nm) = 15° C via fluorescence. This small difference in the T g confinement effect reflects differences in how fluorescence and ellipsometry report “average T g ” with confinement. With decreasing nanoscale thickness, fluorescence may slightly overweight the contribution of the free-surface layer while ellipsometry may evenly weight or underweight its contribution. in here

DESIGN NOTE: On the frustration of back-surface reflection from transparent substrates in ellipsometry

NASA Astrophysics Data System (ADS)

Hayton, D. J.; Jenkins, T. E.

2004-02-01

The effects of back-surface reflection from transparent substrates on ellipsometric measurements are discussed and it is shown that their effects can be minimized by placing the substrate on a commercially available product, Blu-tack. The ellipsometric properties of Blu-tack in the range 250 850 nm are presented and the frustration of the back-surface reflection is discussed in terms of index matching between substrate and Blu-tack.

Immersion transmission ellipsometry (ITE) for the determination of orientation gradients in photoalignment layers

NASA Astrophysics Data System (ADS)

Jung, C. C.; Stumpe, J.

2014-09-01

The capability of the method of immersion transmission ellipsometry (ITE) (Jung et al. Int Patent WO, 2004/109260) to not only determine three-dimensional refractive indices in anisotropic thin films (which was already possible in the past), but even their gradients along the z-direction (perpendicular to the film plane) is investigated in this paper. It is shown that the determination of orientation gradients in deep-sub-μm films becomes possible by applying ITE in combination with reflection ellipsometry. The technique is supplemented by atomic force microscopy for measuring the film thickness. For a photo-oriented thin film, no gradient was found, as expected. For a photo-oriented film, which was subsequently annealed in a nematic liquid crystalline phase, an order was found similar to the one applied in vertically aligned nematic displays, with a tilt angle varying along the z-direction. For fresh films, gradients were only detected for the refractive index perpendicular to the film plane, as expected.

Michelin tire syndrome: a report of two siblings.

PubMed

Kharfi, Monia; Zaraa, Ines; Chaouechi, S; Zekri, Sami; Boukef, Safia; Jaafoura, Habib; Kamoun, Mohamed R

2005-01-01

Michelin tire syndrome is a rare syndrome characterized by excessive folding of the skin. The diagnosis is mainly clinical. It has been found to be associated with noncutaneous anomalies, and probably reflects multiple underlying disorders. We report two siblings with Michelin tire syndrome, a 5-year-old boy and his sister both of whom had marked skin folds and facial anomalies. Histologic study found an increase in smooth muscle fibers of the dermis. Electron microscopy showed details of smooth muscle cells. We also review reported cases in the literature to contribute to a better understanding of this syndrome.

Characterization on Smart Optics Using Ellipsometry

NASA Technical Reports Server (NTRS)

Song, Kyo D.

2002-01-01

Recently, NASA Langley Research Center developed a smart active optical concept to filter narrow band pass or to control optical intensity. To characterize developed smart optics materials, we have measured thickness and reflection properties of the materials using a WVASE32 ellipsometry. This project allowed us to: (1) prepare the smart optical materials for measurement of thickness and optical properties at NASA Langley Research Center; (2) measure thickness and optical properties of the smart optical materials; (3) evaluate the measured properties in terms of applications for narrow band-pass filters. The outcomes of this research provide optical properties and physical properties of the smart optics on a selected spectral range. The applications of this development were used for field-controlled spectral smart filters.

Computer Model Locates Environmental Hazards

NASA Technical Reports Server (NTRS)

2008-01-01

Catherine Huybrechts Burton founded San Francisco-based Endpoint Environmental (2E) LLC in 2005 while she was a student intern and project manager at Ames Research Center with NASA's DEVELOP program. The 2E team created the Tire Identification from Reflectance model, which algorithmically processes satellite images using turnkey technology to retain only the darkest parts of an image. This model allows 2E to locate piles of rubber tires, which often are stockpiled illegally and cause hazardous environmental conditions and fires.

Sensing of Streptococcus mutans by microscopic imaging ellipsometry

NASA Astrophysics Data System (ADS)

Khaleel, Mai Ibrahim; Chen, Yu-Da; Chien, Ching-Hang; Chang, Yia-Chung

2017-05-01

Microscopic imaging ellipsometry is an optical technique that uses an objective and sensing procedure to measure the ellipsometric parameters Ψ and Δ in the form of microscopic maps. This technique is well known for being noninvasive and label-free. Therefore, it can be used to detect and characterize biological species without any impact. Microscopic imaging ellipsometry was used to measure the optical response of dried Streptococcus mutans cells on a glass substrate. The ellipsometric Ψ and Δ maps were obtained with the Optrel Multiskop system for specular reflection in the visible range (λ=450 to 750 nm). The Ψ and Δ images at 500, 600, and 700 nm were analyzed using three different theoretical models with single-bounce, two-bounce, and multibounce light paths to obtain the optical constants and height distribution. The obtained images of the optical constants show different aspects when comparing the single-bounce analysis with the two-bounce or multibounce analysis in detecting S. mutans samples. Furthermore, the height distributions estimated by two-bounce and multibounce analyses of S. mutans samples were in agreement with the thickness values measured by AFM, which implies that the two-bounce and multibounce analyses can provide information complementary to that obtained by a single-bounce light path.

Calculation of optical band gaps of a-Si:H thin films by ellipsometry and UV-Vis spectrophotometry

NASA Astrophysics Data System (ADS)

Qiu, Yijiao; Li, Wei; Wu, Maoyang; Fu, Junwei; Jiang, Yadong

2010-10-01

Hydrogenated amorphous silicon (a-Si:H) thin films doped with Phosphorus (P) and Nitrogen (N) were deposited by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD). The optical band gaps of the thin films obtained through either changing the gas pressure (P-doped only) or adulterating nitrogen concentration (with fixed P content) were investigated by means of Ellipsometric and Ultraviolet-Visible (UV-Vis) spectroscopy, respectively. Tauc formula was used in calculating the optical band gaps of the thin films in both methods. The results show that Ellipsometry and UV-Vis spectrophotometry can be applied in the research of the optical properties of a-Si:H thin films experimentally. Both methods reflect the variation law of the optical band gaps caused by CVD process parameters, i.e., the optical band gap of the a-Si:H thin films is increased with the rise of the gas pressure or the nitrogen concentration respectively. The difference in optical band gaps of the doped a-Si:H thin films calculated by Ellipsometry or UV-Vis spectrophotometry are not so great that they both can be used to measure the optical band gaps of the thin films in practical applications.

Jet Fuel Thermal Stability Investigations Using Ellipsometry

NASA Technical Reports Server (NTRS)

Nash, Leigh; Vasu, Subith S.; Klettlinger, Jennifer Lindsey

2017-01-01

Jet fuels are typically used for endothermic cooling in practical engines where their thermal stability is very important. In this work the thermal stability of Sasol IPK (a synthetic jet fuel) with varying levels of naphthalene has been studied on stainless steel substrates using spectroscopic ellipsometry in the temperature range 385-400 K. Ellipsometry is an optical technique that measures the changes in a light beam’s polarization and intensity after it reflects off of a thin film to determine the film’s thickness and optical properties. All of the tubes used were rated as thermally unstable by the color standard portion of the Jet Fuel Thermal Oxidation Test, and this was confirmed by the deposit thicknesses observed using ellipsometry. A new amorphous model on a stainless steel substrate was used to model the data and obtain the results. It was observed that, as would be expected, increasing the temperature of the tube increased the overall deposit amount for a constant concentration of naphthalene. The repeatability of these measurements was assessed using multiple trials of the same fuel at 385 K. Lastly, the effect of increasing the naphthalene concentration in the fuel at a constant temperature was found to increase the deposit thickness.In conclusion, ellipsometry was used to investigate the thermal stability of jet fuels on stainless steel substrate. The effects of increasing temperature and addition of naphthalene on stainless steel tubes with Sasol IPK fuel were investigated. It was found, as expected, that increasing temperature lead to an increase in deposit thickness. It wasAmerican Institute of Aeronautics and Astronautics6also found that increasing amounts of naphthalene increased the maximum deposit thickness. The repeatability of these measurements was investigated using multiple tests at the same conditions. The present work provides as a better quantitative tool compared to the widely used JFTOT technique. Future work will expand on the fuel types, temperature, and substrate materials.

Combined ellipsometry and refractometry technique for characterisation of liquid crystal based nanocomposites.

PubMed

Warenghem, Marc; Henninot, Jean François; Blach, Jean François; Buchnev, Oleksandr; Kaczmarek, Malgosia; Stchakovsky, Michel

2012-03-01

Spectroscopic ellipsometry is a technique especially well suited to measure the effective optical properties of a composite material. However, as the sample is optically thick and anisotropic, this technique loses its accuracy for two reasons: anisotropy means that two parameters have to be determined (ordinary and extraordinary indices) and optically thick means a large order of interference. In that case, several dielectric functions can emerge out of the fitting procedure with a similar mean square error and no criterion to discriminate the right solution. In this paper, we develop a methodology to overcome that drawback. It combines ellipsometry with refractometry. The same sample is used in a total internal reflection (TIR) setup and in a spectroscopic ellipsometer. The number of parameters to be determined by the fitting procedure is reduced in analysing two spectra, the correct final solution is found by using the TIR results both as initial values for the parameters and as check for the final dielectric function. A prefitting routine is developed to enter the right initial values in the fitting procedure and so to approach the right solution. As an example, this methodology is used to analyse the optical properties of BaTiO(3) nanoparticles embedded in a nematic liquid crystal. Such a methodology can also be used to analyse experimentally the validity of the mixing laws, since ellipsometry gives the effective dielectric function and thus, can be compared to the dielectric function of the components of the mixture, as it is shown on the example of BaTiO(3)/nematic composite.

Optical constants of neat liquid-chemical warfare agents and related materials measured by infrared spectroscopic ellipsometry

NASA Astrophysics Data System (ADS)

Yang, C. S.-C.; Williams, B. R.; Hulet, M. S.; Tiwald, T. E.; Miles, R. W., Jr.; Samuels, A. C.

2011-05-01

We studied various liquids using a vertical attenuated total reflection (ATR) liquid sampling assembly in conjunction with Infrared Variable Angle Spectroscopic Ellipsometry (IR-VASE), to determine the infrared optical constants of several bulk liquids related to chemical warfare. The index of refraction, n, and the extinction coefficient, k, of isopropyl methylphosphonofluoridate (Sarin or GB), isopropyl alcohol (IPA) (a precursor of GB), and dimethyl methylphosphonate (DMMP)-a commonly employed simulant for GB, measured by our vertical ATR IR-VASE setup are closely matched to those found in other studies. We also report the optical constants of cyclohexyl methylphosphonofluoridate (GF), 2-(diisopropylamino)ethyl methylphosphonothioate (VX), bis-(2-chloroethyl) sulfide (HD), and 2-chlorovinyl dichloroarsine (L, Lewisite). The ATR IR-VASE technique affords an accurate measurement of the optical constants of these hazardous compounds.

Spectroscopic ellipsometry study of Cu2ZnSnS4 bulk poly-crystals

NASA Astrophysics Data System (ADS)

Levcenko, S.; Hajdeu-Chicarosh, E.; Garcia-Llamas, E.; Caballero, R.; Serna, R.; Bodnar, I. V.; Victorov, I. A.; Guc, M.; Merino, J. M.; Pérez-Rodriguez, A.; Arushanov, E.; León, M.

2018-04-01

The linear optical properties of Cu2ZnSnS4 bulk poly-crystals have been investigated using spectroscopic ellipsometry in the range of 1.2-4.6 eV at room temperature. The characteristic features identified in the optical spectra are explained by using the Adachi analytical model for the interband transitions at the corresponding critical points in the Brillouin zone. The experimental data have been modeled over the entire spectral range taking into account the lowest E0 transition near the fundamental absorption edge and E1A and E1B higher energy interband transitions. In addition, the spectral dependences of the refractive index, extinction coefficient, absorption coefficient, and normal-incidence reflectivity values have been accurately determined and are provided since they are essential data for the design of Cu2ZnSnS4 based optoelectronic devices.

Growth and characterization of high quality ZnS thin films by RF sputtering

NASA Astrophysics Data System (ADS)

Mukherjee, C.; Rajiv, K.; Gupta, P.; Sinha, A. K.; Abhinandan, L.

2012-06-01

High optical quality ZnS films are deposited on glass and Si wafer by RF sputtering from pure ZnS target. Optical transmittance, reflectance, ellipsometry, FTIR and AFM measurements are carried out. Effect of substrate temperature and chamber baking for long duration on film properties have been studied. Roughness of the films as measured by AFM are low (1-2Å).

Reflective Coating on Fibrous Insulation for Reduced Heat Transfer

NASA Technical Reports Server (NTRS)

Hass, Derek D.; Prasad, B. Durga; Glass, David E.; Wiedemann, Karl E.

1997-01-01

Radiative heat transfer through fibrous insulation used in thermal protection systems (TPS) is significant at high temperatures (1200 C). Decreasing the radiative heat transfer through the fibrous insulation can thus have a major impact on the insulating ability of the TPS. Reflective coatings applied directly to the individual fibers in fibrous insulation should decrease the radiative heat transfer leading to an insulation with decreased effective thermal conductivity. Coatings with high infrared reflectance have been developed using sol-gel techniques. Using this technique, uniform coatings can be applied to fibrous insulation without an appreciable increase in insulation weight or density. Scanning electron microscopy, Fourier Transform infrared spectroscopy, and ellipsometry have been performed to evaluate coating performance.

A hybrid PSO-SVM-based method for predicting the friction coefficient between aircraft tire and coating

NASA Astrophysics Data System (ADS)

Zhan, Liwei; Li, Chengwei

2017-02-01

A hybrid PSO-SVM-based model is proposed to predict the friction coefficient between aircraft tire and coating. The presented hybrid model combines a support vector machine (SVM) with particle swarm optimization (PSO) technique. SVM has been adopted to solve regression problems successfully. Its regression accuracy is greatly related to optimizing parameters such as the regularization constant C , the parameter gamma γ corresponding to RBF kernel and the epsilon parameter \\varepsilon in the SVM training procedure. However, the friction coefficient which is predicted based on SVM has yet to be explored between aircraft tire and coating. The experiment reveals that drop height and tire rotational speed are the factors affecting friction coefficient. Bearing in mind, the friction coefficient can been predicted using the hybrid PSO-SVM-based model by the measured friction coefficient between aircraft tire and coating. To compare regression accuracy, a grid search (GS) method and a genetic algorithm (GA) are used to optimize the relevant parameters (C , γ and \\varepsilon ), respectively. The regression accuracy could be reflected by the coefficient of determination ({{R}2} ). The result shows that the hybrid PSO-RBF-SVM-based model has better accuracy compared with the GS-RBF-SVM- and GA-RBF-SVM-based models. The agreement of this model (PSO-RBF-SVM) with experiment data confirms its good performance.

Structural investigations of human hairs by spectrally resolved ellipsometry

NASA Astrophysics Data System (ADS)

Chan, Danny; Schulz, Benjamin; Rübhausen, Michael; Wessel, Sonya; Wepf, Roger

2006-01-01

Human hair is a biological layered system composed of two major layers, the cortex and the cuticle. We show spectrally resolved ellipsometry measurements of the ellipsometric parameters Ψ and Δ of single human hairs. The spectra reflect the layered nature of hair and the optical anisotropy of the hair's structure. In addition, measurements on strands of human hair show a high reproducibility of the ellipsometric parameters for different hair fiber bundles from the same person. Based on the measurements, we describe a dielectric model of hair that explains the spectra in terms of the dielectric properties of the major parts of hair and their associated layer thicknesses. In addition, surface roughness effects modeled by a roughness layer with a complex refractive index given by an effective medium approach can be seen to have a significant effect on the measurements. We derive values for the parameters of the cuticle surface roughness layer of the thickness dACu=273 to 360 nm and the air inclusion fA=0.6 to 5.7%.

Uncontrolled combustion of shredded tires in a landfill -Part 2: Population exposure, public health response, and an air quality index for urban fires

PubMed Central

Singh, Ashish; Spak, Scott N.; Stone, Elizabeth A.; Downard, Jared; Bullard, Robert; Pooley, Mark; Kostle, Pamela A.; Mainprize, Matthew W.; Wichman, Michael D.; Peters, Thomas; Beardsley, Douglas; Stanier, Charles O.

2015-01-01

The Iowa City Landfill in eastern Iowa, United States, experienced a fire lasting 18 days in 2012, in which a drainage layer of over 1 million shredded tires burned, generating smoke that impacted the surrounding metropolitan area of 130,000 people. This emergency required air monitoring, risk assessment, dispersion modeling, and public notification. This paper quantifies the impact of the fire on local air quality and proposes a monitoring approach and an Air Quality Index (AQI) for use in future tire fires and other urban fires. Individual fire pollutants are ranked for acute and cancer relative risks using hazard ratios, with the highest acute hazard ratios attributed to SO2, particulate matter, and aldehydes. Using a dispersion model in conjunction with the new AQI, we estimate that smoke concentrations reached unhealthy outdoor levels for sensitive groups out to distances of 3.1 km and 18 km at 24-h and 1-h average times, respectively. Modeled and measured concentrations of PM2.5 from smoke and other compounds such as VOCs and benzo[a]pyrene are presented at a range of distances and averaging times, and the corresponding cancer risks are discussed. Through reflection on the air quality response to the event, consideration of cancer and acute risks, and comparison to other tire fires, we recommend that all landfills with shredded tire liners plan for hazmat fire emergencies. A companion paper presents emission factors and detailed smoke characterization. PMID:25624787

Uncontrolled combustion of shredded tires in a landfill -Part 2: Population exposure, public health response, and an air quality index for urban fires.

PubMed

Singh, Ashish; Spak, Scott N; Stone, Elizabeth A; Downard, Jared; Bullard, Robert; Pooley, Mark; Kostle, Pamela A; Mainprize, Matthew W; Wichman, Michael D; Peters, Thomas; Beardsley, Douglas; Stanier, Charles O

2015-03-01

The Iowa City Landfill in eastern Iowa, United States, experienced a fire lasting 18 days in 2012, in which a drainage layer of over 1 million shredded tires burned, generating smoke that impacted the surrounding metropolitan area of 130,000 people. This emergency required air monitoring, risk assessment, dispersion modeling, and public notification. This paper quantifies the impact of the fire on local air quality and proposes a monitoring approach and an Air Quality Index (AQI) for use in future tire fires and other urban fires. Individual fire pollutants are ranked for acute and cancer relative risks using hazard ratios, with the highest acute hazard ratios attributed to SO 2 , particulate matter, and aldehydes. Using a dispersion model in conjunction with the new AQI, we estimate that smoke concentrations reached unhealthy outdoor levels for sensitive groups out to distances of 3.1 km and 18 km at 24-h and 1-h average times, respectively. Modeled and measured concentrations of PM 2.5 from smoke and other compounds such as VOCs and benzo[a]pyrene are presented at a range of distances and averaging times, and the corresponding cancer risks are discussed. Through reflection on the air quality response to the event, consideration of cancer and acute risks, and comparison to other tire fires, we recommend that all landfills with shredded tire liners plan for hazmat fire emergencies. A companion paper presents emission factors and detailed smoke characterization.

Characterization of plasmonic effects in thin films and metamaterials using spectroscopic ellipsometry

NASA Astrophysics Data System (ADS)

Oates, T. W. H.; Wormeester, H.; Arwin, H.

2011-12-01

In this article, spectroscopic ellipsometry studies of plasmon resonances at metal-dielectric interfaces of thin films are reviewed. We show how ellipsometry provides valuable non-invasive amplitude and phase information from which one can determine the effective dielectric functions, and how these relate to the material nanostructure and define exactly the plasmonic characteristics of the system. There are three related plasmons that are observable using spectroscopic ellipsometry; volume plasmon resonances, surface plasmon polaritons and particle plasmon resonances. We demonstrate that the established method of exploiting surface plasmon polaritons for chemical and biological sensing may be enhanced using the ellipsometric phase information and provide a comprehensive theoretical basis for the technique. We show how the particle and volume plasmon resonances in the ellipsometric spectra of nanoparticle films are directly related to size, surface coverage and constituent dielectric functions of the nanoparticles. The regularly observed splitting of the particle plasmon resonance is theoretically described using modified effective medium theories within the framework of ellipsometry. We demonstrate the wealth of information available from real-time in situ spectroscopic ellipsometry measurements of metal film deposition, including the evolution of the plasmon resonances and percolation events. Finally, we discuss how generalized and Mueller matrix ellipsometry hold great potential for characterizing plasmonic metamaterials and sub-wavelength hole arrays.

User oriented end-station on VUV pump-probe magneto-optical ellipsometry at ELI beamlines

NASA Astrophysics Data System (ADS)

Espinoza, Shirly; Neuber, Gerd; Brooks, Christopher D.; Besner, Bastian; Hashemi, Maryam; Rübhausen, Michael; Andreasson, Jakob

2017-11-01

A state of the art ellipsometer for user operations is being implemented at ELI Beamlines in Prague, Czech Republic. It combines three of the most promising and exotic forms of ellipsometry: VUV, pump-probe and magneto-optical ellipsometry. This new ellipsometer covers a spectral operational range from the NIR up to the VUV, with high through-put between 1 and 40 eV. The ellipsometer also allows measurements of magneto-optical spectra with a 1 kHz switchable magnetic field of up to 1.5 T across the sample combining ellipsometry and Kerr spectroscopy measurements in an unprecedented spectral range. This form of generalized ellipsometry enables users to address diagonal and off-diagonal components of the dielectric tensor within one measurement. Pump-probe measurements enable users to study the dynamic behaviour of the dielectric tensor in order to resolve the time-domain phenomena in the femto to 100 ns range.

Characterization and Application of a Grazing Angle Objective for Quantitative Infrared Reflection Microspectroscopy

NASA Technical Reports Server (NTRS)

Pepper, Stephen V.

1995-01-01

A grazing angle objective on an infrared microspectrometer is studied for quantitative spectroscopy by considering the angular dependence of the incident intensity within the objective's angular aperture. The assumption that there is no angular dependence is tested by comparing the experimental reflectance of Si and KBr surfaces with the reflectance calculated by integrating the Fresnel reflection coefficient over the angular aperture under this assumption. Good agreement was found, indicating that the specular reflectance of surfaces can straight-forwardly be quantitatively integrated over the angular aperture without considering non-uniform incident intensity. This quantitative approach is applied to the thickness determination of dipcoated Krytox on gold. The infrared optical constants of both materials are known, allowing the integration to be carried out. The thickness obtained is in fair agreement with the value determined by ellipsometry in the visible. Therefore, this paper illustrates a method for more quantitative use of a grazing angle objective for infrared reflectance microspectroscopy.

Chirality-induced polarization effects in the cuticle of scarab beetles: 100 years after Michelson

NASA Astrophysics Data System (ADS)

Arwin, Hans; Magnusson, Roger; Landin, Jan; Järrendahl, Kenneth

2012-04-01

One hundred years ago Michelson discovered circular polarization in reflection from beetles. Today a novel Mueller-matrix ellipsometry setup allows unprecedented detailed characterization of the beetles' polarization properties. A formalism based on elliptical polarization for description of reflection from scarab beetles is here proposed and examples are given on four beetles of different character: Coptomia laevis - a simple dielectric mirror; Cetonia aurata - a left-hand narrow-band elliptical polarizer; Anoplognathus aureus - a broad-band elliptical polarizer; and Chrysina argenteola - a left-hand polarizer for visible light at small angles, whereas for larger angles, red reflected light is right-handed polarized. We confirm the conclusion of previous studies which showed that a detailed quantification of ellipticity and degree of polarization of cuticle reflection can be performed instead of only determining whether reflections are circularly polarized or not. We additionally investigate reflection as a function of incidence angle. This provides much richer information for understanding the behaviour of beetles and for structural analysis.

Optical characterization of extremely small volumes of liquid in sub-micro-holes by simultaneous reflectivity, ellipsometry and spectrometry.

PubMed

Holgado, M; Casquel, R; Sánchez, B; Molpeceres, C; Morales, M; Ocaña, J L

2007-10-01

We have fabricated and characterized a lattice of submicron cone-shaped holes on a SiO(2)/Si wafer. Reflectivity profiles as a function of angle of incidence and polarization, phase shift and spectrometry are obtained for several fluids with different refractive indexes filling the holes. The optical setup allows measuring in the center of a single hole and collecting all data simultaneously, which can be applied for measuring extremely low volumes of fluid (in the order of 0.1 femtolitres) and label-free immunoassays, as it works as a refractive index sensor. A three layer film stack model is defined to perform theoretical calculations.

Composition and structure of spontaneously adsorbed monolayers of n-perfluorocarboxylic acids on silver

NASA Astrophysics Data System (ADS)

Chau, Lai-Kwan; Porter, Marc D.

1990-03-01

Monolayer films of n-perfluorocarboxylic acids (CF 3(CF 2) nCOOH, where n = 0-2, 5-8) have been formed by spontaneous adsorption at silver. Infrared reflection spectroscopy, optical ellipsometry, and contact angle measurements indicate that these films exhibit low surface free energies, that the carboxylic acid group is symmetrically bound at the silver substrate as a carboxylate bridging ligand, and that the structure is composed of tilted (≈ 40° from the surface normal) perfluorocarbon chains and small structural defects.

Experimental methodology for assessing the environmental fate of organic chemicals in polymer matrices using column leaching studies and OECD 308 water/sediment systems: Application to tire and road wear particles.

PubMed

Unice, Kenneth M; Bare, Jennifer L; Kreider, Marisa L; Panko, Julie M

2015-11-15

Automobile tires require functional rubber additives including curing agents and antioxidants, which are potentially environmentally available from tire and road wear particles (TRWP) deposited in soil and sediment. A novel methodology was employed to evaluate the environmental fate of three commonly-used tire chemicals (N-cyclohexylbenzothiazole-2-sulfenamide (CBS), N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine (6-PPD) and 1,3-diphenylguanidine (DPG)), using a road simulator, an artificial weathering chamber, column leaching tests, and OECD 308 sediment/water incubator studies. Environmental release factors were quantified for curing (f(C)), tire wear (f(W)), terrestrial weathering (f(S)), leaching from TRWP (f(L)), and environmental availability from TRWP (f(A)) by liquid chromatography-tandem mass spectroscopy (LC/MS/MS) analyses. Cumulative fractions representing total environmental availability (F(T)) and release to water (FR) were calculated for the tire chemicals and 13 transformation products. F(T) for CBS, DPG and 6-PPD inclusive of transformation products for an accelerated terrestrial aging time in soil of 0.1 years was 0.08, 0.1, and 0.06, respectively (equivalent to 6 to 10% of formulated mass). In contrast, a wider range of 5.5×10(-4) (6-PPD) to 0.06 (CBS) was observed for F(R) at an accelerated age of 0.1 years, reflecting the importance of hydrophobicity and solubility for determining the release to the water phase. Significant differences (p<0.05) in the weathering factor, f(S), were observed when chemicals were categorized by boiling point or hydrolysis rate constant. A significant difference in the leaching factor, f(L), and environmental availability factor, f(A), was also observed when chemicals were categorized by log K(ow). Our methodology should be useful for lifecycle analysis of other functional polymer chemicals. Copyright © 2015 Elsevier B.V. All rights reserved.

40 CFR 63.6015 - What definitions apply to this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... cements, bead cements, tire building cements and solvents, green tire spray, blemish repair paints, side... in tire component identification; component storage; tire building; tire curing; and tire repair... of warm-up mills, extruders, calendars, tire building, or other tire component and tire manufacturing...

Structural investigations of human hairs by spectrally resolved ellipsometry

NASA Astrophysics Data System (ADS)

Schulz, Benjamin; Chan, D.; Ruebhausen, M.; Wessel, S.; Wepf, R.

2006-03-01

Human hair is a biological layered system composed of two major layers, the cortex and the cuticle. We show spectrally resolved ellipsometry measurements of the ellipsometric parameters ψ and δ of single human hairs. The spectra reflect the layered nature of hair and the optical anisotropy of the hair’s structure. In addition, measurements on strands of human hair show a high reproducibility of the ellipsometric parameters for different hair fiber bundles from the same person. Based on the measurements, we develop a model of the dielectric function of hair that explains the spectra. This model includes the dielectric properties of the cuticle and cortex as well as their associated layer thicknesses. In addition, surface roughness effects modelled by a roughness layer with an complex refractive index given by an effective medium approach can have a significant effect on the measurements. We derive values for the parameters of the cuticle surface roughness layer of the thickness dACu= 273-360 nm and the air inclusion fA= 0.6 -5.7%. [1] accepted for publication in J. Biomed Opt., 2005

Segment density profiles of polyelectrolyte brushes determined by Fourier transform ellipsometry

NASA Astrophysics Data System (ADS)

Biesalski, Markus; Rühe, Jürgen; Johannsmann, Diethelm

1999-10-01

We describe a method for the explicit determination of the segment density profile φ(z) of surface-attached polymer brushes with multiple angle of incidence null-ellipsometry. Because the refractive index contrast between the brush layer and the solvent is weak, multiple reflections are of minor influence and the ellipsometric spectrum is closely related to the Fourier transform of the refractive index profile, thereby allowing for explicit inversion of the ellipsometric data. We chose surface-attached monolayers of polymethacrylic acid (PMAA), a weak polyelectrolyte, as a model system and determined the segment density profile of this system as a function of the pH value of the surrounding medium by the Fourier method. Complementary to the Fourier analysis, fits with error functions are given as well. The brushes were prepared on the bases of high refractive index prisms with the "grafting-from" technique. In water, the brushes swell by more than a factor of 30. The swelling increases with increasing pH because of a growing fraction of dissociated acidic groups leading to a larger electrostatic repulsion.

Recyclable crosslinked polymer networks with full property recovery made via one-step controlled radical polymerization

NASA Astrophysics Data System (ADS)

Jin, Kailong; Li, Lingqiao; Torkelson, John

Rubber tires illustrate well the issues ranging from economic loss to environmental problems and sustainability issues that arise with spent, covalently crosslinked polymers. A nitroxide-mediated polymerization (NMP) strategy has been developed that allows for one-step synthesis of recyclable crosslinked polymers from monomers or polymers that contain carbon-carbon double bonds amenable to radical polymerization. Resulting materials possess dynamic alkoxyamine crosslinks that undergo reversible decrosslinking as a function of temperature. Using polybutadiene as starting material, and styrene, an appropriate nitroxide molecule and bifunctional initiator for initial crosslinking, a model for tire rubber can be produced by reaction at temperatures comparable to those employed in tire molding. Upon cooling, the crosslinks are made permanent due to the extraordinarily strong temperature dependence of the reverisible nitroxide capping and uncapping reaction. Based on thermomechanical property characterization, when the original crosslinked model rubber is chopped into bits and remolded in the melt state, a well-consolidated material is obtained which exhibits full recovery of properties reflecting crosslink density after multiple recycling steps.

Uncontrolled combustion of shredded tires in a landfill - Part 1: Characterization of gaseous and particulate emissions

NASA Astrophysics Data System (ADS)

Downard, Jared; Singh, Ashish; Bullard, Robert; Jayarathne, Thilina; Rathnayake, Chathurika M.; Simmons, Donald L.; Wels, Brian R.; Spak, Scott N.; Peters, Thomas; Beardsley, Douglas; Stanier, Charles O.; Stone, Elizabeth A.

2015-03-01

In summer 2012, a landfill liner comprising an estimated 1.3 million shredded tires burned in Iowa City, Iowa. During the fire, continuous monitoring and laboratory measurements were used to characterize the gaseous and particulate emissions and to provide new insights into the qualitative nature of the smoke and the quantity of pollutants emitted. Significant enrichments in ambient concentrations of CO, CO2, SO2, particle number (PN), fine particulate (PM2.5) mass, elemental carbon (EC), and polycyclic aromatic hydrocarbons (PAH) were observed. For the first time, PM2.5 from tire combustion was shown to contain PAH with nitrogen heteroatoms (a.k.a. azaarenes) and picene, a compound previously suggested to be unique to coal-burning. Despite prior laboratory studies' findings, metals used in manufacturing tires (i.e. Zn, Pb, Fe) were not detected in coarse particulate matter (PM10) at a distance of 4.2 km downwind. Ambient measurements were used to derive the first in situ fuel-based emission factors (EF) for the uncontrolled open burning of tires, revealing substantial emissions of SO2 (7.1 g kg-1), particle number (3.5 × 1016 kg-1), PM2.5 (5.3 g kg-1), EC (2.37 g kg-1), and 19 individual PAH (totaling 56 mg kg-1). A large degree of variability was observed in day-to-day EF, reflecting a range of flaming and smoldering conditions of the large-scale fire, for which the modified combustion efficiency ranged from 0.85 to 0.98. Recommendations for future research on this under-characterized source are also provided.

Uncontrolled combustion of shredded tires in a landfill – Part 1: Characterization of gaseous and particulate emissions

PubMed Central

Downard, Jared; Singh, Ashish; Bullard, Robert; Jayarathne, Thilina; Rathnayake, Chathurika; Simmons, Donald L.; Wels, Brian R.; Spak, Scott N.; Peters, Thomas; Beardsley, Douglas; Stanier, Charles; Stone, Elizabeth A.

2014-01-01

In summer 2012, a landfill liner comprising an estimated 1.3 million shredded tires burned in Iowa City, Iowa. During the fire, continuous monitoring and laboratory measurements were used to characterize the gaseous and particulate emissions and to provide new insights into the qualitative nature of the smoke and the quantity of pollutants emitted. Significant enrichments in ambient concentrations of CO, CO2, SO2, particle number (PN), fine particulate (PM2.5) mass, elemental carbon (EC), and polycyclic aromatic hydrocarbons (PAH) were observed. For the first time, PM2.5 from tire combustion was shown to contain PAH with nitrogen heteroatoms (a.k.a. azaarenes) and picene, a compound previously suggested to be unique to coal-burning. Despite prior laboratory studies’ findings, metals used in manufacturing tires (i.e. Zn, Pb, Fe) were not detected in coarse particulate matter (PM10) at a distance of 4.2 km downwind. Ambient measurements were used to derive the first in situ fuel-based emission factors (EF) for the uncontrolled open burning of tires, revealing substantial emissions of SO2 (7.1 g kg−1), particle number (3.5×1016 kg−1), PM2.5 (5.3 g kg−1), EC (2.37 g kg−1), and 19 individual PAH (totaling 56 mg kg−1). A large degree of variability was observed in day-to-day EF, reflecting a range of flaming and smoldering conditions of the large-scale fire, for which the modified combustion efficiency ranged from 0.85-0.98. Recommendations for future research on this under-characterized source are also provided. PMID:25663800

Characterization of Free-Standing Nano-Membranes by Using Ellipsometry

NASA Astrophysics Data System (ADS)

Park, Sungmo; Lee, Changho; An, Ilsin; Kim, Min-Su; Park, Jin-Goo; Ahn, Jin-ho

2018-04-01

The thickness of the pellicle is only a few tens of microns in extreme ultraviolet lithography (EUVL). This is because the absorption loss by the pellicle is high. Thus, the thickness and contamination on the surface of the EUVL pellicle are important factors for controlling the transmission of EUV light. In this work, we fabricate ultra-thin silicon-nitride membranes for EUVL pellicles and use micro-spot spectroscopic ellipsometry and imaging ellipsometry for characterization. We successfully deduce not only the thickness but also the optical function of the membrane. However, we found that some precautions were required for accurate measurement of the free-standing thin membranes by using ellipsometry. Issues related to the vibration of the membrane and the sensitivity of the measurement are discussed.

Spectroscopic ellipsometry analysis of a thin film composite membrane consisting of polysulfone on a porous α-alumina support.

PubMed

Ogieglo, Wojciech; Wormeester, Herbert; Wessling, Matthias; Benes, Nieck E

2012-02-01

Exposure of a thin polymer film to a fluid can affect properties of the film such as the density and thickness. In particular in membrane technology, these changes can have important implications for membrane performance. Spectroscopic ellipsometry is a convenient technique for in situ studies of thin films, because of its noninvasive character and very high precision. The applicability of spectroscopic ellipsometry is usually limited to samples with well-defined interfacial regions, whereas in typical composite membranes, often substantial and irregular intrusion of the thin film into the pores of a support exists. In this work, we provide a detailed characterization of a polished porous alumina membrane support, using variable-angle spectroscopic ellipsometry in combination with atomic force microscopy and mercury porosimetry. Two Spectroscopic ellipsometry optical models are presented that can adequately describe the surface roughness of the support. These models consider the surface roughness as a distinct layer in which the porosity gradually increases toward the outer ambient interface. The first model considers the porosity profile to be linear; the second model assumes an exponential profile. It is shown that the models can be extended to account for a composite membrane geometry, by deposition of a thin polysulfone film onto the support. The developed method facilitates practicability for in situ spectroscopic ellipsometry studies of nonequilibrium systems, i.e., membranes under actual permeation conditions.

Tests of two new polyurethane foam wheelchair tires.

PubMed

Gordon, J; Kauzlarich, J J; Thacker, J G

1989-01-01

The performance characteristics of four 24-inch wheelchair tires are considered; one pneumatic and three airless. Specifically, two new airless polyurethane foam tires (circular and tapered cross-section) were compared to both a molded polyisoprene tire and a rubber pneumatic tire. Rolling resistance, coefficient of static friction, spring rate, tire roll-off, impact absorption, wear resistance, and resistance to compression set were the characteristics considered for the basis of comparison. Although the pneumatic tire is preferred by many wheelchair users, the two new polyurethane foam tires were found to offer a performance similar to the high-pressure pneumatic tire. In addition, the foam tires are less expensive and lighter in weight than the other tires tested.

Tire safety : everything rides on it

DOT National Transportation Integrated Search

2008-01-01

This booklet presents a comprehensive overview of tire safety, including information on the following topics: basic tire maintenance; Uniform Tire Quality Grading System; fundamental characteristics of tires; and tire safety tips.

Ellipsometry of single-layer antireflection coatings on transparent substrates

NASA Astrophysics Data System (ADS)

Azzam, R. M. A.

2017-11-01

The complex reflection coefficients of p- and s-polarized light and ellipsometric parameters of a transparent substrate of refractive index n2, which is coated by a transparent thin film whose refractive index n1 =√{n2 } satisfies the anti-reflection condition at normal incidence, are considered as functions of film thickness d and angle of incidence ϕ. A unique coated surface, with n1 =√{n2 } and film thickness d equal to half of the film-thickness period Dϕ at angle ϕ and wavelength λ, reflects light of the same wavelength without change of polarization for all incident polarization states. (The reflection Jones matrix of such coated surface is the 2 × 2 identity matrix pre-multiplied by a scalar, hence tanΨ = 1,Δ = 0.) To monitor the deposition of an antireflection coating, the normalized Stokes parameters of obliquely reflected light (e.g. at ϕ =70∘) are measured until predetermined target values of those parameters are detected. This provides a more accurate means of film thickness control than is possible using a micro-balance technique or an intensity reflectance method.

49 CFR 575.106 - Tire fuel efficiency consumer information program.

Code of Federal Regulations, 2013 CFR

2013-10-01

... tires, deep tread, winter-type snow tires, space-saver or temporary use spare tires, tires with nominal... deep tread, winter-type snow tires and limited production tires that it manufactures which are exempt... to have included in the database of information available to consumers on NHTSA's Web site. (ii...

49 CFR 575.106 - Tire fuel efficiency consumer information program.

Code of Federal Regulations, 2014 CFR

2014-10-01

... tires, deep tread, winter-type snow tires, space-saver or temporary use spare tires, tires with nominal... deep tread, winter-type snow tires and limited production tires that it manufactures which are exempt... to have included in the database of information available to consumers on NHTSA's Web site. (ii...

49 CFR 575.106 - Tire fuel efficiency consumer information program.

Code of Federal Regulations, 2012 CFR

2012-10-01

... tires, deep tread, winter-type snow tires, space-saver or temporary use spare tires, tires with nominal... deep tread, winter-type snow tires and limited production tires that it manufactures which are exempt... to have included in the database of information available to consumers on NHTSA's Web site. (ii...

49 CFR 574.1 - Scope.

Code of Federal Regulations, 2010 CFR

2010-10-01

... forth the method by which new tire manufacturers and new tire brand name owners shall identify tires for... retreaded tire brand name owners shall identify tires for use on motor vehicles. This part also sets forth... manufacturers and new tire brand name owners, and by which other tire dealers and distributors shall record and...

Rolling Resistance of Pneumatic Tires

DOT National Transportation Integrated Search

1975-01-01

Potential improvements in tire power transmission efficiency are worth seeking for gaining improved automotive fuel economy. Summaries herein of tire rolling resistance as influenced by tire construction and design, tire materials, and tire operating...

Rolling Resistance of Pneumatic Tires

DOT National Transportation Integrated Search

1979-05-01

Potential improvements in tire power transmission efficiency are worth seeking for gaining improved automotive fuel economy. Summaries herein of tire rolling resistance as influenced by tire construction and design, tire materials, and tire operating...

Phenomena of Pneumatic Tire Hydroplaning

NASA Technical Reports Server (NTRS)

Dreher, R. C.; Horne, W. B.

1963-01-01

Recent research on pneumatic tire hydroplaning has been collected and summarized with the aim of describing what is presently known about the phenomena of tire hydroplaning. A physical description of tire hydroplaning is given along with formulae for estimating the ground speed at which it occurs. Eight manifestations of tire hydroplaning which have been experimentally observed are presented and discussed. These manifestations are: detachment of tire footprint, hydrodynamic ground pressure, spin-down of wheel, suppression of tire bow wave, scouring action of escaping fluid in tire-ground footprint region, peaking of fluid displacement drag, loss in braking traction, and loss of tire directional stability. The vehicle, pavement, tire, and fluid parameters of importance to tire hydroplaning are listed and described. Finally, the hazards of tire hydroplaning to ground and air-vehicle-ground performance are listed, and procedures are given to minimize these effects.

Energy dissipation in a rolling aircraft tire

NASA Technical Reports Server (NTRS)

Tielking, John T.

1988-01-01

The project is extending an existing finite element tire model to calculate the energy dissipation in a free-rolling aircraft tire and temperature buildup in the tire carcass. The model will provide a means of calculating the influence of tire design on the distribution of tire temperature. Current focus is on energy loss measurements of aircraft tire material. The feasibility of taking test specimens directly from the tire carcass for measurements of viscoelastic properties was demonstrated. The interaction of temperature and frequency effects on material loss properties was studied. The tire model was extended to calculate the cyclic energy change in a tire during rolling under load. Input data representing the 40 by 14 aircraft tire whose material loss properties were measured are being used.

49 CFR 574.7 - Information requirements-new tire manufacturers, new tire brand name owners.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Information requirements-new tire manufacturers, new tire brand name owners. 574.7 Section 574.7 Transportation Other Regulations Relating to..., new tire brand name owners. (a)(1) Each new tire manufacturer and each new tire brand name owner...

Evaluation of space environmental effects on metals and optical thin films on EOIM-3

NASA Technical Reports Server (NTRS)

Vaughn, Jason A.; Linton, Roger C.; Finckenor, Miria M.; Kamenetzky, Rachel R.

1995-01-01

Metals and optical thin films exposed to the space environment on the Third Flight of the Evaluation of Oxygen Interactions with Materials (EOIM-3) payload, onboard Space Shuttle mission STS-46 were evaluated. The materials effects described in this paper include the effects of space exposure on various pure metals, optical thin films, and optical thin film metals. The changes induced by exposure to the space environment in the material properties were evaluated using bidirectional reflectance distribution function (BRDF), specular reflectance (250 nm to 2500 nm), ESCA, VUV reflectance (120 nm to 200 nm), ellipsometry, FTIR and optical properties. Using these analysis techniques gold optically thin film metal mirrors with nickel undercoats were observed to darken due to nickel diffusion through the gold to the surface. Also, thin film nickel mirrors formed nickel oxide due to exposure to both the atmosphere and space.

49 CFR 575.106 - Tire fuel efficiency consumer information program.

Code of Federal Regulations, 2010 CFR

2010-10-01

... tires, deep tread, winter-type snow tires, space-saver or temporary use spare tires, tires with nominal... Web site. (ii) Requirements for tire retailers. Subject to paragraph (e)(1)(iii) of this section, each...

49 CFR 575.106 - Tire fuel efficiency consumer information program.

Code of Federal Regulations, 2011 CFR

2011-10-01

... tires, deep tread, winter-type snow tires, space-saver or temporary use spare tires, tires with nominal... Web site. (ii) Requirements for tire retailers. Subject to paragraph (e)(1)(iii) of this section, each...

Ultrasonic search wheel probe

DOEpatents

Mikesell, Charles R.

1978-01-01

A device is provided for reducing internal reflections from the tire of an ultrasonic search wheel probe or from within the material being examined. The device includes a liner with an anechoic chamber within which is an ultrasonic transducer. The liner is positioned within the wheel and includes an aperture through which the ultrasonic sound from the transducer is directed.

Current Research in Aircraft Tire Design and Performance

NASA Technical Reports Server (NTRS)

Tanner, J. A.; Mccarthy, J. L.; Clark, S. K.

1981-01-01

A review of the tire research programs which address the various needs identified by landing gear designers and airplane users is presented. The experimental programs are designed to increase tire tread lifetimes, relate static and dynamic tire properties, establish the tire hydroplaning spin up speed, study gear response to tire failures, and define tire temperature profiles during taxi, braking, and cornering operations. The analytical programs are aimed at providing insights into the mechanisms of heat generation in rolling tires and developing the tools necessary to streamline the tire design process and to aid in the analysis of landing gear problems.

Infrared spectroscopic ellipsometry of micrometer-sized SiO2 line gratings

NASA Astrophysics Data System (ADS)

Walder, Cordula; Zellmeier, Matthias; Rappich, Jörg; Ketelsen, Helge; Hinrichs, Karsten

2017-09-01

For the design and process control of periodic nano-structured surfaces spectroscopic ellipsometry is already established in the UV-VIS spectral regime. The objective of this work is to show the feasibility of spectroscopic ellipsometry in the infrared, exemplarily, on micrometer-sized SiO2 line gratings grown on silicon wafers. The grating period ranges from 10 to about 34 μm. The IR-ellipsometric spectra of the gratings exhibit complex changes with structure variations. Especially in the spectral range of the oxide stretching modes, the presence of a Rayleigh singularity can lead to pronounced changes of the spectrum with the sample geometry. The IR-ellipsometric spectra of the gratings are well reproducible by calculations with the RCWA method (Rigorous Coupled Wave Analysis). Therefore, infrared spectroscopic ellipsometry allows the quantitative characterization and process control of micrometer-sized structures.

Influence of different processing techniques on the mechanical properties of used tires in embankment construction.

PubMed

Edinçliler, Ayşe; Baykal, Gökhan; Saygili, Altug

2010-06-01

Use of the processed used tires in embankment construction is becoming an accepted way of beneficially recycling scrap tires due to shortages of natural mineral resources and increasing waste disposal costs. Using these used tires in construction requires an awareness of the properties and the limitations associated with their use. The main objective of this paper is to assess the different processing techniques on the mechanical properties of used tires-sand mixtures to improve the engineering properties of the available soil. In the first part, a literature study on the mechanical properties of the processed used tires such as tire shreds, tire chips, tire buffings and their mixtures with sand are summarized. In the second part, large-scale direct shear tests are performed to evaluate shear strength of tire crumb-sand mixtures where information is not readily available in the literature. The test results with tire crumb were compared with the other processed used tire-sand mixtures. Sand-used tire mixtures have higher shear strength than that of the sand alone and the shear strength parameters depend on the processing conditions of used tires. Three factors are found to significantly affect the mechanical properties: normal stress, processing techniques, and the used tire content. Copyright 2009. Published by Elsevier Ltd.

Infrared spectroscopic ellipsometry in semiconductor manufacturing

NASA Astrophysics Data System (ADS)

Guittet, Pierre-Yves; Mantz, Ulrich; Weidner, Peter; Stehle, Jean-Louis; Bucchia, Marc; Bourtault, Sophie; Zahorski, Dorian

2004-05-01

Infrared spectroscopic ellipsometry (IRSE) metrology is an emerging technology in semiconductor production environment. Infineon Technologies SC300 implemented the first worldwide automated IRSE in a class 1 clean room in 2002. Combining properties of IR light -- large wavelength, low absorption in silicon -- with a short focus optics -- no backside reflection -- which allow model-based analysis, a large number of production applications were developed. Part of Infineon IRSE development roadmap is now focused on depth monitoring for arrays of 3D dry-etched structures. In trench DRAM manufacturing, the areal density is high, and critical dimensions are much lower than mid-IR wavelength. Therefore, extensive use of effective medium theory is made to model 3D structures. IR-SE metrology is not limited by shrinking critical dimensions, as long as the areal density is above a specific cut-off value determined by trenches dimensions, trench-filling and surrounding materials. Two applications for depth monitoring are presented. 1D models were developed and successfully applied to the DRAM trench capacitor structures. Modeling and correlation to reference methods are shown as well as dynamic repeatability and gauge capability results. Limitations of the current tool configuration are reviewed for shallow structures.

Tire Footprint Affects Hydroplaning On Wet Pavement

NASA Technical Reports Server (NTRS)

Yager, Thomas J.

1989-01-01

Recent investigations of tire hydroplaning at highway speeds reveal, in addition to inflation pressure, tire-footprint aspect ratio (FAR), defined as width divided by length of tire surface in contact with pavement, significantly influences speed at which dynamic hydroplaning begins. Tire speeds and forces developed during tests of up to 65 mi/h (105 km/h) were monitored on flooded test surface to identify development of hydroplaning. Study focused on automotive tires because FAR's of automotive tires vary more than those of aircraft tires.

Advances and trends in the development of computational models for tires

NASA Technical Reports Server (NTRS)

Noor, A. K.; Tanner, J. A.

1985-01-01

Status and some recent developments of computational models for tires are summarized. Discussion focuses on a number of aspects of tire modeling and analysis including: tire materials and their characterization; evolution of tire models; characteristics of effective finite element models for analyzing tires; analysis needs for tires; and impact of the advances made in finite element technology, computational algorithms, and new computing systems on tire modeling and analysis. An initial set of benchmark problems has been proposed in concert with the U.S. tire industry. Extensive sets of experimental data will be collected for these problems and used for evaluating and validating different tire models. Also, the new Aircraft Landing Dynamics Facility (ALDF) at NASA Langley Research Center is described.

Study of in-plane dynamics of tires

NASA Astrophysics Data System (ADS)

Gong, S.

1993-12-01

The in-plane dynamics of tires deals with the forces and motion in the plane of rotation of the wheel. Three aspects of tire in-plane dynamics can be identified: the rolling contact between the tire and the road surface; the transmission of forces and motion from the contact patch to the wheel axle; and the vibration of the tire treadband. The main objective of the investigation reported in this thesis is to develop a tire model which is suitable to study all three aspects of the in-plane dynamics of tires in both low and high frequency ranges. The tire model is finally validated by experimental modal analysis of a test tire. Laboratory tests are conducted to establish the modal shapes and natural frequencies of the test tire. The tests are carried out for two different configurations of the tire: one with the wheel rim fixed in space and one with the tire-wheel system suspended freely in the air. Good agreement is found between the experimental and theoretical results.

Effect of wheelchair mass, tire type and tire pressure on physical strain and wheelchair propulsion technique.

PubMed

de Groot, Sonja; Vegter, Riemer J K; van der Woude, Lucas H V

2013-10-01

The purpose of this study was to evaluate the effect of wheelchair mass, solid vs. pneumatic tires and tire pressure on physical strain and wheelchair propulsion technique. 11 Able-bodied participants performed 14 submaximal exercise blocks on a treadmill with a fixed speed (1.11 m/s) within 3 weeks to determine the effect of tire pressure (100%, 75%, 50%, 25% of the recommended value), wheelchair mass (0 kg, 5 kg, or 10 kg extra) and tire type (pneumatic vs. solid). All test conditions (except pneumatic vs. solid) were performed with and without instrumented measurement wheels. Outcome measures were power output (PO), physical strain (heart rate (HR), oxygen uptake (VO2), gross mechanical efficiency (ME)) and propulsion technique (timing, force application). At 25% tire pressure PO and subsequently VO2 were higher compared to 100% tire pressure. Furthermore, a higher tire pressure led to a longer cycle time and contact angle and subsequently lower push frequency. Extra mass did not lead to an increase in PO, physical strain or propulsion technique. Solid tires led to a higher PO and physical strain. The solid tire effect was amplified by increased mass (tire × mass interaction). In contrast to extra mass, tire pressure and tire type have an effect on PO, physical strain or propulsion technique of steady-state wheelchair propulsion. As expected, it is important to optimize tire pressure and tire type. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

Structure and Thermotropic phase Behavior of Fluorinated Phospholipid Bilayers: A combined Attenuated Total Reflection FTIR Spectroscopy and Imaging Ellipsometry Study

PubMed Central

Schuy, Steffen; Faiss, Simon; Yoder, Nicholas C.; Kalsani, Venkateshwarlu; Kumar, Krishna; Janshoff, Andreas; Vogel, Reiner

2008-01-01

Lipid bilayers consisting of lipids with terminally perfluoroalkylated chains have remarkable properties. They exhibit increased stability and phase-separated nanoscale patterns in mixtures with nonfluorinated lipids. In order to understand the bilayer properties that are responsible for this behavior, we have analyzed the structure of solid-supported bilayers composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and of a DPPC analogue with 6 terminal perfluorinated methylene units (F6-DPPC). Polarized attenuated total reflection Fourier-transform infrared spectroscopy indicates that for F6-DPPC, the tilt of the lipid acyl chains to the bilayer normal is increased to 39° as compared to 21° for native DPPC, for both lipids in the gel phase. This substantial increase of the tilt angle is responsible for a decrease of the bilayer thickness from 5.4 nm for DPPC to 4.5 nm for F6-DPPC, as revealed by temperature-controlled imaging ellipsometry on microstructured lipid bilayers and solution atomic force microscopy. During the main phase transition from the gel to the fluid phase, both the relative bilayer thickness change and the relative area change are substantially smaller for F6-DPPC than for DPPC. In light of these structural and thermotropic data, we propose a model in which the higher acyl-chain tilt angle in F6-DPPC is the result of a conformational rearrangement to minimize unfavorable fluorocarbon–hydrocarbon interactions in the center of the bilayer due to chain staggering. PMID:18563929

49 CFR 569.9 - Labeling of regroovable tires.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Labeling of regroovable tires. 569.9 Section 569.9... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION REGROOVED TIRES § 569.9 Labeling of regroovable tires. (a) Regroovable tires. After August 30, 1969, each tire designed and constructed for regrooving shall be labeled...

Federal Research Action Plan (FRAP) on Recycled Tire Crumb Used on Playing Fields and Playgrounds

EPA Science Inventory

This is part of the stakeholder engagement effort for the Federal Research Action Plan on Recycled Tire Crumb Used on Playing Fields and Playgrounds. The 2017 California Tire Conference gathers those interested and involved in waste tire management, tire-derived products and tire...

Structural modeling of aircraft tires

NASA Technical Reports Server (NTRS)

Clark, S. K.; Dodge, R. N.; Lackey, J. I.; Nybakken, G. H.

1973-01-01

A theoretical and experimental investigation of the feasibility of determining the mechanical properties of aircraft tires from small-scale model tires was accomplished. The theoretical results indicate that the macroscopic static and dynamic mechanical properties of aircraft tires can be accurately determined from the scale model tires although the microscopic and thermal properties of aircraft tires can not. The experimental investigation was conducted on a scale model of a 40 x 12, 14 ply rated, type 7 aircraft tire with a scaling factor of 8.65. The experimental results indicate that the scale model tire exhibited the same static mechanical properties as the prototype tire when compared on a dimensionless basis. The structural modeling concept discussed in this report is believed to be exact for mechanical properties of aircraft tires under static, rolling, and transient conditions.

Lightweight tire concept for space shuttle

NASA Technical Reports Server (NTRS)

Shufflebotham, W. T.

1973-01-01

Various tests were conducted on a 49x17/26 PR aircraft tire that had been designed as a lightweight tire for use on the C-5A military transport. This tire is approximately 25 per cent lighter than a tire of the same size and ply rating that would be used in commercial airline service. The tires were tested at 40 per cent, 37 per cent, and 35 per cent deflections. These deflections were obtained by adjusting the inflation pressure while the load on the tire remained constant at 60,000 pounds. It was determined that the tire would operate successfully under the test conditions at 35% deflection. Prior to testing, the tires were subjected to conditions of high vacuum and low temperature. It was determined that the tires were not adversely affected by these conditions.

Skin blister formation together with patterned intradermal hematoma: a special type of tire mark injury in victims run over by a wheel.

PubMed

Pircher, R; Epting, T; Schmidt, U; Geisenberger, D; Pollak, S; Kramer, L

2015-04-01

A traffic accident victim run over by a vehicle may show a patterned skin hematoma reflecting the grooves of the tire's profile. Apart from this well-known type of imprint mark, the affected skin can also be blistered provided that the wheel exerts high pressure on the body for a prolonged period of time. The macro- and micromorphological findings as well as the protein composition of the blister fluid were investigated on the basis of a relevant autopsy case. Analogous to blisters associated with hanging marks, the transudation of serous fluid with consecutive detachment of the epidermis is interpreted as a pressure-related effect which cannot be regarded as a sign of vitality. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

29 CFR 779.366 - Recapping or retreading tires for sale.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Establishments Automotive Tire Establishments § 779.366 Recapping or retreading tires for sale. (a) Some automotive tire establishments engage in recapping and retreading work on tires which the establishment...

29 CFR 779.366 - Recapping or retreading tires for sale.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Establishments Automotive Tire Establishments § 779.366 Recapping or retreading tires for sale. (a) Some automotive tire establishments engage in recapping and retreading work on tires which the establishment...

29 CFR 779.366 - Recapping or retreading tires for sale.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Establishments Automotive Tire Establishments § 779.366 Recapping or retreading tires for sale. (a) Some automotive tire establishments engage in recapping and retreading work on tires which the establishment...

29 CFR 779.366 - Recapping or retreading tires for sale.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Establishments Automotive Tire Establishments § 779.366 Recapping or retreading tires for sale. (a) Some automotive tire establishments engage in recapping and retreading work on tires which the establishment...

The effects of varying the tire cap ply, sidewall filler height and pavement surface texture on tire/pavement noise generation

DOT National Transportation Integrated Search

2003-02-01

In order to better understand the effect of tire carcass construction and pavement texture on tire/pavement noise generation, a measurement program was conducted on a group of four automobile tires on three pavement textures. The tires included all c...

A Strain-Based Method to Estimate Slip Angle and Tire Working Conditions for Intelligent Tires Using Fuzzy Logic.

PubMed

Garcia-Pozuelo, Daniel; Yunta, Jorge; Olatunbosun, Oluremi; Yang, Xiaoguang; Diaz, Vicente

2017-04-16

Tires equipped with sensors, the so-called "intelligent tires", can provide vital information for control systems, drivers and external users. In this research, tire dynamic strain characteristics in cornering conditions are collected and analysed in relation to the variation of tire working conditions, such as inflation pressure, rolling speed, vertical load and slip angle. An experimental tire strain-based prototype and an indoor tire test rig are used to demonstrate the suitability of strain sensors to establish relations between strain data and lateral force. The results of experiments show that strain values drop sharply when lateral force is decreasing, which can be used to predict tire slip conditions. As a first approach to estimate some tire working conditions, such as the slip angle and vertical load, a fuzzy logic method has been developed. The simulation and test results confirm the feasibility of strain sensors and the proposed computational model to solve the non-linearity characteristics of the tires' parameters and turn tires into a source of useful information.

Microwave Absorption Characteristics of Tire

NASA Astrophysics Data System (ADS)

Zhang, Yuzhe; Hwang, Jiann-Yang; Peng, Zhiwei; Andriese, Matthew; Li, Bowen; Huang, Xiaodi; Wang, Xinli

The recycling of waste tires has been a big environmental problem. About 280 million waste tires are produced annually in the United States and more than 2 billion tires are stockpiled, which cause fire hazards and health issues. Tire rubbers are insoluble elastic high polymer materials. They are not biodegradable and may take hundreds of years to decompose in the natural environment. Microwave irradiation can be a thermal processing method for the decomposition of tire rubbers. In this study, the microwave absorption properties of waste tire at various temperatures are characterized to determine the conditions favorable for the microwave heating of waste tires.

Retractable barrier strip

DOEpatents

Marts, Donna J.; Barker, Stacey G.; McQueen, Miles A.

1996-01-01

A portable barrier strip having retractable tire-puncture means for puncturing a vehicle tire. The tire-puncture means, such as spikes, have an armed position for puncturing a tire and a retracted position for not puncturing a tire. The strip comprises a plurality of barrier blocks having the tire-puncture means removably disposed in a shaft that is rotatably disposed in each barrier block. The shaft removably and pivotally interconnects the plurality of barrier blocks. Actuation cables cause the shaft to rotate the tire-puncture means to the armed position for puncturing a vehicle tire and to the retracted position for not puncturing the tire. Each tire-puncture means is received in a hollow-bed portion of its respective barrier block when in the retracted position. The barrier strip rests stable in its deployed position and substantially motionless as a tire rolls thereon and over. The strip is rolled up for retrieval, portability, and storage purposes, and extended and unrolled in its deployed position for use.

Retractable barrier strip

DOEpatents

Marts, D.J.; Barker, S.G.; McQueen, M.A.

1996-04-16

A portable barrier strip is described having retractable tire-puncture means for puncturing a vehicle tire. The tire-puncture means, such as spikes, have an armed position for puncturing a tire and a retracted position for not puncturing a tire. The strip comprises a plurality of barrier blocks having the tire-puncture means removably disposed in a shaft that is rotatably disposed in each barrier block. The shaft removably and pivotally interconnects the plurality of barrier blocks. Actuation cables cause the shaft to rotate the tire-puncture means to the armed position for puncturing a vehicle tire and to the retracted position for not puncturing the tire. Each tire-puncture means is received in a hollow-bed portion of its respective barrier block when in the retracted position. The barrier strip rests in its deployed position and substantially motionless as a tire rolls thereon and over. The strip is rolled up for retrieval, portability, and storage purposes, and extended and unrolled in its deployed position for use. 13 figs.

Vehicle Tire and Wheel Creation in BRL-CAD

DTIC Science & Technology

2009-04-01

Tire Tread Modeling 4  4.  Setting Tire Thickness 7  5.  Changing the Rim Width 9  6.  Changing the Radial Location of the... treaded or nontreaded model in the tire -model.c combination based on the analysis. 4. Setting Tire Thickness Tire thickness is manipulated via... tread is not modeled by default but can be added using options. • Fine-grained control of parameters such as tire thickness is available with

A Strain-Based Method to Detect Tires' Loss of Grip and Estimate Lateral Friction Coefficient from Experimental Data by Fuzzy Logic for Intelligent Tire Development.

PubMed

Yunta, Jorge; Garcia-Pozuelo, Daniel; Diaz, Vicente; Olatunbosun, Oluremi

2018-02-06

Tires are a key sub-system of vehicles that have a big responsibility for comfort, fuel consumption and traffic safety. However, current tires are just passive rubber elements which do not contribute actively to improve the driving experience or vehicle safety. The lack of information from the tire during driving gives cause for developing an intelligent tire. Therefore, the aim of the intelligent tire is to monitor tire working conditions in real-time, providing useful information to other systems and becoming an active system. In this paper, tire tread deformation is measured to provide a strong experimental base with different experiments and test results by means of a tire fitted with sensors. Tests under different working conditions such as vertical load or slip angle have been carried out with an indoor tire test rig. The experimental data analysis shows the strong relation that exists between lateral force and the maximum tensile and compressive strain peaks when the tire is not working at the limit of grip. In the last section, an estimation system from experimental data has been developed and implemented in Simulink to show the potential of strain sensors for developing intelligent tire systems, obtaining as major results a signal to detect tire's loss of grip and estimations of the lateral friction coefficient.

78 FR 35357 - Bridgestone Americas Tire Operations, LLC, Grant of Petition for Decision of Inconsequential...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-12

... the petition and all supporting documents log onto the Federal Docket Management System (FDMS) Web... approximately 467 Firestone brand Transforce AT, size LT265/70R17, light truck replacement tires manufactured... participants had knowledge of tire labeling beyond the tire brand name, tire size, and tire pressure. Since...

40 CFR 428.10 - Applicability; description of the tire and inner tube plants subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the tire... Tire and Inner Tube Plants Subcategory § 428.10 Applicability; description of the tire and inner tube... pollutants resulting from the production of pneumatic tires and inner tubes in tire and inner tube plants...

49 CFR 575.104 - Uniform tire quality grading standards.

Code of Federal Regulations, 2013 CFR

2013-10-01

... on a pavement surface. (B) Mount each tire on a rim of design or measuring rim width specified for... importation into the United States by the tire's manufacturer of tires of the same design and size as the tire... domestic purchase or importation into the United States by a brand name owner of tires of the same design...

49 CFR 575.104 - Uniform tire quality grading standards.

Code of Federal Regulations, 2012 CFR

2012-10-01

... on a pavement surface. (B) Mount each tire on a rim of design or measuring rim width specified for... importation into the United States by the tire's manufacturer of tires of the same design and size as the tire... domestic purchase or importation into the United States by a brand name owner of tires of the same design...

49 CFR 575.104 - Uniform tire quality grading standards.

Code of Federal Regulations, 2011 CFR

2011-10-01

... on a pavement surface. (B) Mount each tire on a rim of design or measuring rim width specified for... importation into the United States by the tire's manufacturer of tires of the same design and size as the tire... domestic purchase or importation into the United States by a brand name owner of tires of the same design...

49 CFR 575.104 - Uniform tire quality grading standards.

Code of Federal Regulations, 2010 CFR

2010-10-01

... on a pavement surface. (B) Mount each tire on a rim of design or measuring rim width specified for... importation into the United States by the tire's manufacturer of tires of the same design and size as the tire... domestic purchase or importation into the United States by a brand name owner of tires of the same design...

49 CFR 575.104 - Uniform tire quality grading standards.

Code of Federal Regulations, 2014 CFR

2014-10-01

... on a pavement surface. (B) Mount each tire on a rim of design or measuring rim width specified for... importation into the United States by the tire's manufacturer of tires of the same design and size as the tire... domestic purchase or importation into the United States by a brand name owner of tires of the same design...

A Tire Air Maintenance Technology

ERIC Educational Resources Information Center

Pierce, Alan

2012-01-01

Improperly inflated car tires can reduce gas mileage and car performance, speed up tire wear, and even cause a tire to blow out. The AAA auto club recommends that someone check the air pressure of one's car's tires at least once a month. Wouldn't it be nice, though, if someone came up with a tire pressure-monitoring system that automatically kept…

49 CFR 230.113 - Wheels and tire defects.

Code of Federal Regulations, 2012 CFR

2012-10-01

... crack or break in the flange, tread, rim, plate, hub or brackets. (b) Flat spots. Wheels and tires may... 49 Transportation 4 2012-10-01 2012-10-01 false Wheels and tire defects. 230.113 Section 230.113... Tenders Wheels and Tires § 230.113 Wheels and tire defects. Steam locomotive and tender wheels or tires...

49 CFR 230.113 - Wheels and tire defects.

Code of Federal Regulations, 2010 CFR

2010-10-01

... crack or break in the flange, tread, rim, plate, hub or brackets. (b) Flat spots. Wheels and tires may... 49 Transportation 4 2010-10-01 2010-10-01 false Wheels and tire defects. 230.113 Section 230.113... Tenders Wheels and Tires § 230.113 Wheels and tire defects. Steam locomotive and tender wheels or tires...

49 CFR 230.113 - Wheels and tire defects.

Code of Federal Regulations, 2014 CFR

2014-10-01

... crack or break in the flange, tread, rim, plate, hub or brackets. (b) Flat spots. Wheels and tires may... 49 Transportation 4 2014-10-01 2014-10-01 false Wheels and tire defects. 230.113 Section 230.113... Tenders Wheels and Tires § 230.113 Wheels and tire defects. Steam locomotive and tender wheels or tires...

49 CFR 230.113 - Wheels and tire defects.

Code of Federal Regulations, 2013 CFR

2013-10-01

... crack or break in the flange, tread, rim, plate, hub or brackets. (b) Flat spots. Wheels and tires may... 49 Transportation 4 2013-10-01 2013-10-01 false Wheels and tire defects. 230.113 Section 230.113... Tenders Wheels and Tires § 230.113 Wheels and tire defects. Steam locomotive and tender wheels or tires...

49 CFR 230.113 - Wheels and tire defects.

Code of Federal Regulations, 2011 CFR

2011-10-01

... crack or break in the flange, tread, rim, plate, hub or brackets. (b) Flat spots. Wheels and tires may... 49 Transportation 4 2011-10-01 2011-10-01 false Wheels and tire defects. 230.113 Section 230.113... Tenders Wheels and Tires § 230.113 Wheels and tire defects. Steam locomotive and tender wheels or tires...

Tires: Traffic Safety Tips

DOT National Transportation Integrated Search

1996-01-01

This fact sheet, NHTSA Facts: Summer 1996, discuses motor vehicle tires. It includes how to buy the right tires (obtaining tires of the correct size, type and tread); how to grade the tires (treadwear, traction, and temperature resistance); and how t...

Research and application of online measurement system of tire tread profile in automobile tire production

NASA Astrophysics Data System (ADS)

Wang, Pengyao; Chen, Xiangguang; Yang, Kai; Liu, Xuejiao

2017-01-01

To improve the measuring efficiency of width and thickness of tire tread in the process of automobile tire production, the actual condition for the tire production process is analyzed, and a fast online measurement system based on moving tire tread of tire specifications is established in this paper. The coordinate data of tire tread profile is acquired by 3D laser sensor, and we use C# language for programming which is an object-oriented programming language to complete the development of client program. The system with laser sensor can provide real-time display of tire tread profile and the data to require in the process of tire production. Experimental results demonstrate that the measuring precision of the system is <= 1mm, it can meet the measurement requirements of the production process, and the system has the characteristics of convenient installation and testing, system stable operation.

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

PubMed

Sarkissian, Garry

2007-09-01

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

Recovery and disposal of discarded tires in the Taiwan area.

PubMed

Hwang, J S; Roam, G D

1994-12-01

Urbanization and industrialization has resulted in a vast amount of artificial water containers in Taiwan, especially discarded automobile tires. 3.5 million automobile tires and several million motorcycle tires are discarded annually. The discarded tires contaminate the environment and also become a substantial number of breeding sites for the dengue vector mosquitoes. In order to establish a sound system for the recovery and disposal of discarded tires and to control dengue fever through source reduction, it has been emphasized that users must pay for their waste. It is necessary to recover and properly dispose of these discarded tired. The commercial firms which sell or manufacture tires are therefore advised to cooperate with the Environmental Protection Administration of the Executive Yuan, R.O.C. and follow the "Regulations of Recovery and Disposal of Discarded Tires". They are requested to establish foundations for the recovery of discarded tires. Those who are willing to join should prepay a deposit or related charge by the size of tire, which is imported or locally manufactured. The foundation utilizes the deposits for the recovery and disposal of discarded tires. From 1991 to 1993 the commercial tire firms had already achieved the 80% recovery rates declared by the authorities concerned. Some of the tires, after having been recovered, were recycled in the original form and the rest were cut into small pieces for recycling after physical treatment. It should be mentioned that the Department of Environmental Protection of Kaohsiung City has collected 80 thousand discarded automobile tires to be used as ocean jetty.(ABSTRACT TRUNCATED AT 250 WORDS)

Results of Rolling Resistance Measurements of Twelve Radial Passenger Car Tires

DOT National Transportation Integrated Search

1980-01-01

The Calspan Tire Research Facility is described, including the test procedure, a tire test schedule, and a tire identification schedule for testing low-rolling resistance radial passenger car tires. The equilibrium rolling resistance was measured on ...

49 CFR 574.5 - Tire identification requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Tire identification requirements. 574.5 Section... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) TIRE IDENTIFICATION AND RECORDKEEPING § 574.5 Tire identification requirements. Each tire manufacturer shall conspicuously label on one...

Wireless Monitoring of Automobile Tires for Intelligent Tires

PubMed Central

Matsuzaki, Ryosuke; Todoroki, Akira

2008-01-01

This review discusses key technologies of intelligent tires focusing on sensors and wireless data transmission. Intelligent automobile tires, which monitor their pressure, deformation, wheel loading, friction, or tread wear, are expected to improve the reliability of tires and tire control systems. However, in installing sensors in a tire, many problems have to be considered, such as compatibility of the sensors with tire rubber, wireless transmission, and battery installments. As regards sensing, this review discusses indirect methods using existing sensors, such as that for wheel speed, and direct methods, such as surface acoustic wave sensors and piezoelectric sensors. For wireless transmission, passive wireless methods and energy harvesting are also discussed. PMID:27873979

Friction characteristics of 20 x 4.4, type 7, aircraft tires constructed with different tread rubber compounds

NASA Technical Reports Server (NTRS)

Dreher, R. C.; Yager, T. J.

1976-01-01

A test program was conducted at the Langley aircraft landing loads and traction facility to evaluate the friction characteristics of 20 x 4.4, type, aircraft tires constructed with experimental cut-resistant, tread rubber compounds. These compounds consisted of different blends of natural rubber (NR) and an alfin catalyzed styrene-butadiene copolymer rubber (SBR). One tire having a blend of 30 SBR and 70 NR and another having a blend of 60 SBR and 40 NR in the tread were tested together with a standard production tire with no SBR content in the tread rubber. The results of this investigation indicated that the test tires constructed with the special cut-resistant tread rubber compositions did not suffer any significant degradation in tire friction capability when compared with the standard tire. In general, tire friction capability decreased with increasing speed and surface wetness condition. As yaw angle increased, tire braking capability decreased while tire cornering capability increased. Tread-wear data based on number of brake cycles, however, suggested that the tires with alfin SBR blends experienced significantly greater wear than the standard production tire.

Spring Tire

NASA Technical Reports Server (NTRS)

Asnani, Vivake M.; Benzing, Jim; Kish, Jim C.

2011-01-01

The spring tire is made from helical springs, requires no air or rubber, and consumes nearly zero energy. The tire design provides greater traction in sandy and/or rocky soil, can operate in microgravity and under harsh conditions (vastly varying temperatures), and is non-pneumatic. Like any tire, the spring tire is approximately a toroidal-shaped object intended to be mounted on a transportation wheel. Its basic function is also similar to a traditional tire, in that the spring tire contours to the surface on which it is driven to facilitate traction, and to reduce the transmission of vibration to the vehicle. The essential difference between other tires and the spring tire is the use of helical springs to support and/or distribute load. They are coiled wires that deform elastically under load with little energy loss.

A comparative review of optical surface contamination assessment techniques

NASA Technical Reports Server (NTRS)

Heaney, James B.

1987-01-01

This paper will review the relative sensitivities and practicalities of the common surface analytical methods that are used to detect and identify unwelcome adsorbants on optical surfaces. The compared methods include visual inspection, simple reflectometry and transmissiometry, ellipsometry, infrared absorption and attenuated total reflectance spectroscopy (ATR), Auger electron spectroscopy (AES), scanning electron microscopy (SEM), secondary ion mass spectrometry (SIMS), and mass accretion determined by quartz crystal microbalance (QCM). The discussion is biased toward those methods that apply optical thin film analytical techniques to spacecraft optical contamination problems. Examples are cited from both ground based and in-orbit experiments.

Spectroscopic ellipsometry in vacuum ultraviolet spectral area

NASA Astrophysics Data System (ADS)

Fuchs, Detlef

An ellipsometer is developed and built, which allows the direct spectroscopic evaluation of dielectric function of solid bodies in the energy area 5 to 35 eV. A linear polarized synchrotron radiation was used as light source. The Stokes parameters and the Mueller matrices were used for the mathematical modeling, which take into account the properties of the synchrotron light and the analyzer, which depend on the wavelength. The crystals of the semiconductor bindings GaAs, GaP, InP and ZnS were examined. Ellipsometric measurements and reflection spectra show a displacement of spectral structures towards lower photon energies after the storage.

“A System for Automatically Maintaining Pressure in a Commercial Truck Tire”

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

Maloney, John

2017-07-07

Under-inflated tires significantly reduce a vehicle’s fuel efficiency by increasing rolling resistance (drag force). The Air Maintenance Technology (“AMT”) system developed through this project replenishes lost air and maintains optimal tire cavity pressure whenever the tire is rolling in service, thus improving overall fuel economy by reducing the tire’s rolling resistance. The system consists of an inlet air filter, an air pump driven by tire deformation during rotation, and a pressure regulating device. Pressurized air in the tire cavity naturally escapes by diffusion through the tire and wheel, leaks in tire seating, and through the filler valve and its seating.more » As a result, tires require constant maintenance to replenish lost air. Since manual tire inflation maintenance is both labor intensive and time consuming, it is frequently overlooked or ignored. By automating the maintenance of optimal tire pressure, the tire’s contribution to the vehicle’s overall fuel economy can be maximized. The work was divided into three phases. The objectives of Phase 1, Planning and Initial Design, resulted in an effective project plan and to create a baseline design. The objectives for Phase 2, Design and Process Optimization, were: to identify finalized design for the pump, regulator and filter components; identify a process to build prototype tires; assemble prototype tires; test prototype tires and document results. The objectives of Phase 3, Design Release and Industrialization, were to finalize system tire assembly, perform release testing and industrialize the assembly process.« less

Scattering and polarization properties of the scarab beetle Cyphochilus insulanus cuticle.

PubMed

Åkerlind, Christina; Arwin, Hans; Hallberg, Tomas; Landin, Jan; Gustafsson, Johan; Kariis, Hans; Järrendahl, Kenneth

2015-07-01

Optical properties of natural photonic structures can inspire material developments in diversified areas, such as the spectral design of surfaces for camouflage. Here, reflectance, scattering, and polarization properties of the cuticle of the scarab beetle Cyphochilus insulanus are studied with spectral directional hemispherical reflectance, bidirectional reflection distribution function (BRDF) measurements, and Mueller-matrix spectroscopic ellipsometry (MMSE). At normal incidence, a reflectance (0.6-0.75) is found in the spectral range of 400-1600 nm and a weaker reflectance <0.2 in the UV range as well as for wavelengths >1600  nm. A whiteness of W=42 is observed for mainly the elytra of the beetle. Chitin is a major constituent of the insect cuticle which is verified by the close similarity of the measured IR spectrum to that of α-chitin. The BRDF signal shows close-to-Lambertian properties of the beetle for visible light at small angles of incidence. From the MMSE measurement it is found that the beetles appear as dielectric reflectors reflecting linearly polarized light at oblique incidence with low gloss and a low degree of polarization. The measured beetle properties are properties that can be beneficial in a camouflage material.

Mechanical Properties Experimental Study of Engineering Vehicle Refurbished Tire

NASA Astrophysics Data System (ADS)

Qiang, Wang; Xiaojie, Qi; Zhao, Yang; Yunlong, Wang; Guotian, Wang; Degang, Lv

2018-05-01

The vehicle refurbished tire test system was constructed, got load-deformation, load-stiffness, and load-compression ratio property laws of engineering vehicle refurbished tire under the working condition of static state and ground contact, and built radial direction loading deformation mathematics model of 26.5R25 engineering vehicle refurbished tire. The test results show that radial-direction and side-direction deformation value is a little less than that of the new tire. The radial-direction stiffness and compression ratio of engineering vehicle refurbished tire were greatly influenced by radial-direction load and air inflation pressure. When load was certain, radial-direction stiffness would increase with air inflation pressure increasing. When air inflation pressure was certain, compression ratio of engineering vehicle refurbished tire would enlarge with radial-direction load increasing, which was a little less than that of the new and the same type tire. Aging degree of old car-case would exert a great influence on deformation property of engineering vehicle refurbished tire, thus engineering vehicle refurbished tires are suitable to the working condition of low tire pressure and less load.

77 FR 10476 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Notice of Second...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-22

...-the-Road Tires From the People's Republic of China: Notice of Second Extension of Time Limit for the... duty order on certain new pneumatic off-the-road tires (``off-the-road tires'') from the People's... on off- the-road tires from the PRC. See Certain New Pneumatic Off-the-Road Tires from the People's...

75 FR 62504 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Notice of Decision...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-12

...-the-Road Tires From the People's Republic of China: Notice of Decision of the Court of International...-road tires (``OTR tires'') from the People's Republic of China (``PRC''). See GPX Int'l Tire Corp. v... tires from the PRC. The final judgment in this case was not in harmony with the Department's July 2008...

Land Vehicle Tire Qualification: DSCC Annual Tire Conference

DTIC Science & Technology

2011-03-24

liner separations - Tire induced loss of air -Exposed or broken casing -Bulges in tread or sidewall SAE J2014 UNCLASSIFIED 11 SAE J2014 4.14 Tire ...Treadlife Durability -10000 miles duration -Evaluate tread wear performance of candidate tire -Measurements at prescribed intervals - Tread depth at centerline...shoulder -Diameter, section width, tread arc width -Conducted on courses required for mission profile Criteria: -Candidate tire exceeds 95% of

Land Vehicle Tire Qualification

DTIC Science & Technology

2009-03-25

Bead damage / separation -Severe open splices and/or liner separations - Tire induced loss of air -Exposed or broken casing -Bulges in tread or...sidewall SAE J2014 11 SAE J2014 4.14 Tire Treadlife Durability -10000 miles duration -Evaluate tread wear performance of candidate tire -Measurements at... Tread Depth measurement of reference and candidate tires taken at specified intervals • Candidate tires must complete the test and tread wear projections

Wheels and Tires: Understanding the Numbers on the Sides of Tires Might Lead to Longer Life Tires and Improved Driving Safety

ERIC Educational Resources Information Center

Ritz, John M.

2005-01-01

Automotive wheels and tires require knowledge to understand their specifications and use. While the durability and useful life of tires have increased substantially over the last several decades, in all probability consumers will purchase a number of vehicle tires over their lifetime. Knowing how they are made and what the numbers mean will assist…

Tire/runway friction interface

NASA Technical Reports Server (NTRS)

Yager, Thomas J.

1990-01-01

An overview is given of NASA Langley's tire/runway pavement interface studies. The National Tire Modeling Program, evaluation of new tire and landing gear designs, tire wear and friction tests, and tire hydroplaning studies are examined. The Aircraft Landing Dynamics Facility is described along with some ground friction measuring vehicles. The major goals and scope of several joint FAA/NASA programs are identified together with current status and plans.

Haul truck tire dynamics due to tire condition

NASA Astrophysics Data System (ADS)

Vaghar Anzabi, R.; Nobes, D. S.; Lipsett, M. G.

2012-05-01

Pneumatic tires are costly components on large off-road haul trucks used in surface mining operations. Tires are prone to damage during operation, and these events can lead to injuries to personnel, loss of equipment, and reduced productivity. Damage rates have significant variability, due to operating conditions and a range of tire fault modes. Currently, monitoring of tire condition is done by physical inspection; and the mean time between inspections is often longer than the mean time between incipient failure and functional failure of the tire. Options for new condition monitoring methods include off-board thermal imaging and camera-based optical methods for detecting abnormal deformation and surface features, as well as on-board sensors to detect tire faults during vehicle operation. Physics-based modeling of tire dynamics can provide a good understanding of the tire behavior, and give insight into observability requirements for improved monitoring systems. This paper describes a model to simulate the dynamics of haul truck tires when a fault is present to determine the effects of physical parameter changes that relate to faults. To simulate the dynamics, a lumped mass 'quarter-vehicle' model has been used to determine the response of the system to a road profile when a failure changes the original properties of the tire. The result is a model of tire vertical displacement that can be used to detect a fault, which will be tested under field conditions in time-varying conditions.

Rubber tire leachates in the aquatic environment.

PubMed

Evans, J J

1997-01-01

Tires have a deleterious effect on the environment. This review discusses the background of scrap tires discarded in the environment, including tire composition, adverse environmental effects, threats to public health and safety, and solid waste management. Despite the widespread use of scrap tires in environmental applications, both land-based and aquatic, data on the indicators of environmental degradation are extremely scarce. Indicators of environmental degradation include analysis of chemicals within the water and sediment, analysis of contaminants within organisms, and analysis of the biological effects of these compounds on plants, animals, microbes, and organelles. Although these indicators are most useful when used in parallel, a review of the available information on chemical characterization of tire leachate from tire storage facilities, manufacturing, usage in recycling applications, and toxicity exposure studies, of vegetation surveys from waste tire areas and reviews of mammalian tire product toxicity, and of toxicity, mutagenicity, and carcinogenicity of tire exposure in experimental aquatic animals, microbes, and organelles is presented. The major characteristics of these studies are discussed in specific sections. The "Discussion and Conclusions" section discusses and summarizes the biological effects and chemical characterization of tire leachates. A global environmental perspective is included to improve our understanding of the deficiency of the current knowledge of tire leachate toxicity from various sources and to encourage interdisciplinary studies to establish the pattern of pollution associated with waste tire management.

The prediction of airborne and structure-borne noise potential for a tire

NASA Astrophysics Data System (ADS)

Sakamoto, Nicholas Y.

Tire/pavement interaction noise is a major component of both exterior pass-by noise and vehicle interior noise. The current testing methods for ranking tires from loud to quiet require expensive equipment, multiple tires, and/or long experimental set-up and run times. If a laboratory based off-vehicle test could be used to identify the airborne and structure-borne potential of a tire from its dynamic characteristics, a relative ranking of a large group of tires could be performed at relatively modest expense. This would provide a smaller sample set of tires for follow-up testing and thus save expense for automobile OEMs. The focus of this research was identifying key noise features from a tire/pavement experiment. These results were compared against a stationary tire test in which the natural response of the tire to a forced input was measured. Since speed was identified as having some effect on the noise, an input function was also developed to allow the tires to be ranked at an appropriate speed. A relative noise model was used on a second sample set of tires to verify if the ranking could be used against interior vehicle measurements. While overall level analysis of the specified spectrum had mixed success, important noise generating features were identified, and the methods used could be improved to develop a standard off-vehicle test to predict a tire's noise potential.

49 CFR 574.6 - Identification mark.

Code of Federal Regulations, 2010 CFR

2010-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) TIRE IDENTIFICATION AND RECORDKEEPING § 574.6... retreaded pneumatic tires, non-pneumatic tires or non-pneumatic tire assemblies shall apply in writing to... Street SW., Washington, DC 20590, identify itself as a tire manufacturer or retreader and furnish the...

Tire aging: a human factors analysis of failure to warn and inform.

PubMed

Wogalter, Michael S; Laughery, Kenneth R

2012-01-01

A scenario of an automotive accident caused by tire failure is given followed by a human factors analysis of the information available to consumers on tire aging. Consumers have not been told that the age of the tire is a safety concern. It is not easy to decode the date of manufacture on tires. More publicity and prominent warnings are needed to communicate the dangers of older tires. Also, better ways to present the date of manufacture so that consumers can more easily and accurately assess tire age are needed.

An analysis of tire tread wear groove patterns and the effect of heteroscedasticity on tire tread wear statistics

DOT National Transportation Integrated Search

1985-09-01

This report examines the groove wear variability among tires subjected to the : Uniform Tire Quality Grading (UTQC) test procedure for determining tire tread wear. : The effects of heteroscedasticity (variable variance) on a previously reported : sta...

49 CFR 569.7 - Requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., DEPARTMENT OF TRANSPORTATION REGROOVED TIRES § 569.7 Requirements. (a) Regrooved tires. (1) Except as... for introduction into interstate commerce regrooved tires produced by removing rubber from the surface of a worn tire tread to generate a new tread pattern. Any person who regrooves tires and leases them...

Study of the use of truck tire beads as drainage pipe and analysis of the economics of tire disposal in Oklahoma. Part 1. Culverts. Final report

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

Everett, J.W.; Gattis, J.L.

1994-07-01

In an attempt to find alternate ways of dealing with waste truck tires, a private tire recycling company developed a pipe from the tire bead and sidewall. The tire-pipe has seen limited use as a roadway drainage culvert. To encourage wider use of this product, an evaluation of pipe performance was performed. The evaluation consisted of (1) inspections of existing installations; (2) structural tests; and (3) leakage tests. The study found that the majority of installations were performing well. Compared with corrugated steel and fiberglass pipes, the tire-pipe exhibited favorable structural performance. An individual tire-pipe section was found to bemore » watertight. However, when tested in the open-air (not in the ground), the tire-pipe joints were found to leak. Development of an improved end connection would improve the utility of the tire-pipe.« less

The generation of tire cornering forces in aircraft with a free-swiveling nose gear

NASA Technical Reports Server (NTRS)

Daugherty, R. H.; Stubbs, S. M.

1985-01-01

An experimental investigation was conducted to study the effect of various parameters on the cornering forces produced by a rolling aircraft tire installed on a tilted, free-swiveling nose gear. The parameters studied included tilt angle, trial, tire inflation pressure, rake angle, vertical load, and whether or not a twin tire configuration corotates. These parameters were evaluated by measuring the cornering force produced by an aircraft tire installed on the nose gear of a modified vehicle as it was towed slowly. Cornering force coefficient increased with increasing tilt angle. Increasing trial or rake angle decreased the magnitude of the cornering force coefficient. Tire inflation pressure had no effect on the cornering force coefficient. Increasing vertical load decreased the cornering force coefficient. When the tires of a twin tire system rotated independently, the cornering force coefficients were the same as those for the single-tire configuration. When the twin tire system was made to corotate, however, the cornering force coefficients increased significantly.

Exploiting symmetries in the modeling and analysis of tires

NASA Technical Reports Server (NTRS)

Noor, Ahmed K.; Andersen, Carl M.; Tanner, John A.

1987-01-01

A simple and efficient computational strategy for reducing both the size of a tire model and the cost of the analysis of tires in the presence of symmetry-breaking conditions (unsymmetry in the tire material, geometry, or loading) is presented. The strategy is based on approximating the unsymmetric response of the tire with a linear combination of symmetric and antisymmetric global approximation vectors (or modes). Details are presented for the three main elements of the computational strategy, which include: use of special three-field mixed finite-element models, use of operator splitting, and substantial reduction in the number of degrees of freedom. The proposed computational stategy is applied to three quasi-symmetric problems of tires: linear analysis of anisotropic tires, through use of semianalytic finite elements, nonlinear analysis of anisotropic tires through use of two-dimensional shell finite elements, and nonlinear analysis of orthotropic tires subjected to unsymmetric loading. Three basic types of symmetry (and their combinations) exhibited by the tire response are identified.

A study of the cornering forces generated by aircraft tires on a tilted, free-swiveling nose gear

NASA Technical Reports Server (NTRS)

Daugherty, R. H.; Stubbs, S. M.

1985-01-01

An experimental investigation was conducted to study the effect of various parameters on the cornering forces produced by a rolling aircraft tire installed on a tilted, free-swiveling nose gear. The parameters studied included tilt angle, trial, tire inflation pressure, rake angle, vertical load, and whether or not a twin tire configuration corotates. These parameters were evaluated by measuring the cornering force produced by an aircraft tire installed on the nose gear of a modified vehicle as it was towed slowly. Cornering force coefficient increased with increasing tilt angle. Increasing trial or rake angle decreased the magnitude of the cornering force coefficient. Tire inflation pressure had no effect on the cornering force coefficient. Increasing vertical load decreased the cornering force coefficient. When the tires of a twin tire system rotated independently, the cornering force coefficients were the same as those for the single-tire configuration. When the twin tire system was made to corotate, however, the cornering force coefficients increased significantly.

Forestry Tire Tractive Performance: New, Worn, and with Chains

Treesearch

C.R. Vechinski; C.R. Johnson; R.L. Raper; T.P. McDonald

1999-01-01

The tractive perfomance of a new tire, a worn tire, and a worn tire with forestry tire chains was measured in four soil types. Two of the soil types simulated forest-floor conditions with one soil type having a sulfate cover of pine straw and the other having a surface cover of sod. The two remaining soil types were bare. The worn tire with and without chains had...

Studded and unstudded winter tires in fatal road accidents in Finland.

PubMed

Malmivuo, Mikko; Luoma, Juha; Porthin, Markus

2017-07-04

The aim of the study was to compare the safety effects of studded and unstudded winter tires based on fatal road accidents. The data included 958 road accidents involving a passenger car or van that occurred in Finland from November to March between 1997 and 2012. Comparing the proportions of winter tire type in accidents and in general traffic showed that the overall effect of tire type on the number of accidents was not significant, although studded tires reduced fatal accidents by 10-15%. Compared to unstudded tires, studded tires reduced accidents significantly only on bald ice in 2005-2012. Drivers using unstudded tires were more experienced and their profession was more frequently related to driving. In addition, the vehicle age was lower for vehicles with unstudded tires. On the other hand, the state of repair was less pertinent for unstudded than for studded tires. These confounding factors offset their effects to some degree. The risk of fatal road accidents in winter between studded and unstudded tires does not differ significantly. However, the accident risk has recently been substantially higher on bald ice for unstudded than for studded tires. The magnitude of this risk difference is difficult to determine without specific information on exposure by road surface.

Tire footprint studies

NASA Technical Reports Server (NTRS)

Chawla, Mangal; Medzorian, John

1995-01-01

This presentation covers the results of tire footprint studies conducted in the Landing Gear Development Facility of the USAF Wright Laboratory at the Wright Patterson Air force Base, OH. Tire footprint studies are essential in understanding tire wear mechanisms and computing tire tread wear rates. The power input into the tread is the driving force for tread wear. Variables needed for power input calculations include the footprint pressure and slip velocity distributions. Studies were performed on the effects of power input distributions due to vertical load, camber, yaw, inflation pressure, and tire construction. For the present study, two tire constructions, one radial and the other bias, were selected. These tires were for the F-16 Block 30 fighter aircraft, both of which were previously worn. The present study was limited to steady straight roll with a 14,000 lb vertical load, a 310 psi inflation pressure, and zero yaw and camber. All tests were conducted on the Tire Force Machine (TFM) with a specialized sensor plate with embedded pressure sensors (X, Y, and Z) and slip sensors (X and Y). All tests were conducted for a table speed of 1 in/s. Tests on the TFM show that the power intensity distributions and total power for both tire constructions are quite similar for straight roll. Later on, tests were also conducted on a modified dynamometer which was overlaid with a grit wear surface. The tire speed was maintained at 40 miles per hour and yaw was set to four degrees. Dynamometer tests showed that radial tires have more tread wear than the bias tire; however, in the field, radial tires have longer life.

49 CFR 574.4 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., DEPARTMENT OF TRANSPORTATION (CONTINUED) TIRE IDENTIFICATION AND RECORDKEEPING § 574.4 Applicability. This... retreaded tires, and new non-pneumatic tires and non-pneumatic tire assemblies for use on motor vehicles... does not apply to persons who retread tires solely for their own use. [36 FR 5422, Mar. 23, 1971, as...

41 CFR 101-25.110 - Tire identification/registration program.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Tire identification...-General Policies § 101-25.110 Tire identification/registration program. The regulations issued by the Department of Transportation in 49 CFR part 574, Tire Identification and Recordkeeping, require that tire...

40 CFR 63.6006 - How do I demonstrate continuous compliance with the emission limits for tire cord production...

Code of Federal Regulations, 2010 CFR

2010-07-01

... compliance with the emission limits for tire cord production affected sources? 63.6006 Section 63.6006... Hazardous Air Pollutants: Rubber Tire Manufacturing Continuous Compliance Requirements for Tire Cord... tire cord production affected sources? (a) You must demonstrate continuous compliance with each...

Geotechnical Investigation of the Potential Use of Shredded Scrap Tires in Soil Stabilization.

DOT National Transportation Integrated Search

1998-11-01

Silt-tire and clay-tire mixtures, containing 0% to 100% shredded tire material by weight, with tire chips ranging in size from 7mm-13mm, 13mm-25mm, and 25mm-38mm, were tested for a series of engineering properties including compaction characteristics...

SCRAP TIRE RECYCLING: CONVINCING BUSINESSES TO INTEGRATE INEXPENSIVE, CUTTING-EDGE TECHNOLOGY TO CONVERT TIRES INTO VARIOUS CONSTRUCTION MATERIALS

EPA Science Inventory

Scrap tires cause serious environmental pollution and health problems. Although worldwide figures are imprecise, it is known that one-fourth of the 283 million tires scrapped in the United States were landfilled last year. Hundreds of millions more tires ar...

Survivability Enhanced Run-Flat Variable Footprint Tires

DTIC Science & Technology

2010-08-17

with tire tread . By varying the thickness and geometry of the polyurethane soft layer, this unique tire -wheel assembly can generate a wide array of...carcass severely damaged/punctured, provide the same dynamic deflection as the normal pneumatic tire , and provide similar tread life. Could a tire be...be for an optimized shape. Fig 8 shows the actual process applied to a current tire . The carbon fiber was added by removing the tread , cutting

Flexible and conductive waste tire-derived carbon/polymer composite paper as pseudocapacitive electrode

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

Naskar, Amit K.; Paranthaman, Mariappan Parans; Boota, Muhammad

A method of making a supercapacitor from waste tires, includes the steps of providing rubber pieces and contacting the rubber pieces with a sulfonation bath to produce sulfonated rubber; pyrolyzing the sulfonated rubber to produce a tire-derived carbon composite comprising carbon black embedded in rubber-derived carbon matrix comprising graphitized interface portions; activating the tire-derived carbon composite by contacting the tire-derived carbon composite with a specific surface area-increasing composition to increase the specific surface area of the carbon composite to provide an activated tire-derived carbon composite; and, mixing the activated tire-derived carbon composite with a monomer and polymerizing the monomer tomore » produce a redox-active polymer coated, activated tire-derived carbon composite. The redox-active polymer coated, activated tire-derived carbon composite can be formed into a film. An electrode and a supercapacitor are also disclosed.« less

A lateral dynamics of a wheelchair: identification and analysis of tire parameters.

PubMed

Silva, L C A; Corrêa, F C; Eckert, J J; Santiciolli, F M; Dedini, F G

2017-02-01

In vehicle dynamics studies, the tire behaviour plays an important role in planar motion of the vehicle. Therefore, a correct representation of tire is a necessity. This paper describes a mathematical model for wheelchair tire based on the Magic Formula model. This model is widely used to represent forces and moments between the tire and the ground; however some experimental parameters must be determined. The purpose of this work is to identify the tire parameters for the wheelchair tire model, implementing them in a dynamic model of the wheelchair. For this, we developed an experimental test rig to measure the tires parameters for the lateral dynamics of a wheelchair. This dynamic model was made using a multi-body software and the wheelchair behaviour was analysed and discussed according to the tire parameters. The result of this work is one step further towards the understanding of wheelchair dynamics.

Loading Deformation Characteristic Simulation Study of Engineering Vehicle Refurbished Tire

NASA Astrophysics Data System (ADS)

Qiang, Wang; Xiaojie, Qi; Zhao, Yang; Yunlong, Wang; Guotian, Wang; Degang, Lv

2018-05-01

The paper constructed engineering vehicle refurbished tire computer geometry model, mechanics model, contact model, finite element analysis model, did simulation study on load-deformation property of engineering vehicle refurbished tire by comparing with that of the new and the same type tire, got load-deformation of engineering vehicle refurbished tire under the working condition of static state and ground contact. The analysis result shows that change rules of radial-direction deformation and side-direction deformation of engineering vehicle refurbished tire are close to that of the new tire, radial-direction and side-direction deformation value is a little less than that of the new tire. When air inflation pressure was certain, radial-direction deformation linear rule of engineer vehicle refurbished tire would increase with load adding, however, side-direction deformation showed linear change rule, when air inflation pressure was low; and it would show increase of non-linear change rule, when air inflation pressure was very high.

Static and yawed-rolling mechanical properties of two type 7 aircraft tires

NASA Technical Reports Server (NTRS)

Tanner, J. A.; Stubbs, S. M.; Mccarty, J. L.

1981-01-01

Selected mechanical properties of 18 x 5.5 and 49 x 17 size, type 7 aircraft tires were evaluated. The tires were subjected to pure vertical loads and to combined vertical and lateral loads under both static and rolling conditions. Parameters for the static tests consisted of tire load in the vertical and lateral directions, and parameters for the rolling tests included tire vertical load, yaw angle, and ground speed. Effects of each of these parameters on the measured tire characteristics are discussed and, where possible, compared with previous work. Results indicate that dynamic tire properties under investigation were generally insensitive to speed variations and therefore tend to support the conclusion that many tire dynamic characteristics can be obtained from static and low speed rolling tests. Furthermore, many of the tire mechanical properties are in good agreement with empirical predictions based on earlier research.

Polycyclic aromatic hydrocarbons, elemental and organic carbon emissions from tire-wear.

PubMed

Aatmeeyata; Sharma, Mukesh

2010-09-15

Tire-wear is an important source of PAHs, elemental carbon (EC) and organic carbon (OC). The emissions of these pollutants have been studied in an experimental set-up, simulating a realistic road-tire interaction (summer tire-concrete road). The large particle non-exhaust emissions (LPNE; diameter greater than 10 microm) have been evaluated over 14,500 km run of the tire. An increasing linear trend with cumulative km run was observed for emissions of PAHs and carbon. Amongst PAHs in LPNE, pyrene has been observed to be the highest (30+/-4 mg kg(-1)) followed by benzo[ghi]perylene (17+/-2 mg kg(-1)). Different fractions of EC-OC for tire-wear have been analyzed, and unlike exhaust emissions, EC1 was observed to be 99% of EC whereas more than 70% of the OC was the high temperature carbon (OC3 and OC4). The overall emission factors (mass tire(-1) km(-1)) for PAHs, EC and OC from tire-wear are 378 ng tire(-1) km(-1), 1.46 mg tire(-1) km(-1) and 2.37 mg tire(-1) km(-1) for small cars. Copyright 2010 Elsevier B.V. All rights reserved.

Controlling plasmonic properties of epitaxial thin films of indium tin oxide in the near-infrared region

NASA Astrophysics Data System (ADS)

Kamakura, R.; Fujita, K.; Murai, S.; Tanaka, K.

2015-06-01

Epitaxial thin films of indium tin oxide (ITO) were grown on yttria-stabilized zirconia single-crystal substrates by using a pulsed laser deposition to examine their plasmonic properties. The dielectric function of ITO was characterized by spectroscopic ellipsometry. Through the concentration of SnO2 in the target, the carrier concentration in the films was modified, which directly leads to the tuning of the dielectric function in the near-infrared region. Variable-angle reflectance spectroscopy in the Kretschmann geometry shows the dip in the reflection spectrum of p-polarized light corresponding to the excitation of surface plasmon polaritions (SPPs) in the near-infrared region. The excitation wavelength of the SPPs was shifted with changing the dielectric functions of ITO, which is reproduced by the calculation using transfer matrix method.

Optical, dielectric and morphological studies of sol-gel derived nanocrystalline TiO2 films.

PubMed

Vishwas, M; Sharma, Sudhir Kumar; Narasimha Rao, K; Mohan, S; Gowda, K V Arjuna; Chakradhar, R P S

2009-10-15

Nanocrystalline TiO(2) films have been synthesized on glass and silicon substrates by sol-gel technique. The films have been characterized with optical reflectance/transmittance in the wavelength range 300-1000 nm and the optical constants (n, k) were estimated by using envelope technique as well as spectroscopic ellipsometry. Morphological studies have been carried out using atomic force microscope (AFM). Metal-Oxide-Silicon (MOS) capacitor was fabricated using conducting coating on TiO(2) film deposited on silicon. The C-V measurements show that the film annealed at 300 degrees C has a dielectric constant of 19.80. The high percentage of transmittance, low surface roughness and high dielectric constant suggests that it can be used as an efficient anti-reflection coating on silicon and other optical coating applications and also as a MOS capacitor.

All-Metal Tires

NASA Technical Reports Server (NTRS)

Bickler, Donald B.; Sword, Lee F.; Lindemann, Randel A.

1994-01-01

Tires used where elastomeric and pneumatic tires would not function. Metal tires withstand extreme temperatures. Used on Earth for vehicles and robots that fight fires or clean up dangerous chemicals.

Tire Modeling

NASA Technical Reports Server (NTRS)

Tanner, J. A. (Compiler)

1983-01-01

The workshop was organized into six sessions dealing with finite element developments, applications to tire dynamic problems, solution techniques for tire contact problems, experimental data, tire thermal studies, and current design practices.

Tread wear and footprint geometrical characters of truck bus radial tires

NASA Astrophysics Data System (ADS)

Liang, Chen; Wang, Guolin; An, Dengfeng; Ma, Yinwei

2013-05-01

Wear and mileage performance are the foremost performances for truck bus radial (TBR) tires. There are a lot of researches about the tire wear performance as well as the contact patch phenomenon by using finite element analysis (FEA) method or testing. But there is little published data on the correlations between the footprint geometry and the tread wear performance of tires. In this paper, an experiment on tire-ground performance of TBR tires is carried out by using Tekscan. The real-time changes of contact-area pressure distribution that occurred during the process of continuous load and unload are recorded. Three types of tires that act differently in behavior under normal usage are analyzed. A new method of researching in tire tread wear, which focuses on the geometrical characters of the footprint, is put forward. The experimental results of the three tires are described by using footprint geometrical characters. On the basis of studying the changing laws of footprint geometrical characters during the loading process and considering consumer survey and factory feedback information, the correlations between the geometrical character of footprints and tread destruction form are built. The analyzed results show that a greater contact area coefficient and a steady coefficient of contact result in a better wear performance for TBR tires. The footprint-shape coefficient changing laws in the process of loading are found to have a very good coincidence with the tread wear of the three types of tires. Tires with a smaller footprint-shape coefficient are likely to have an average tread wear while avoiding the shoulder wear first. The proposed research provides a new solution to predict tire-ground performance at the point of footprint and several useful references for improving tire design.

Multivalent-Ion-Activated Protein Adsorption Reflecting Bulk Reentrant Behavior.

PubMed

Fries, Madeleine R; Stopper, Daniel; Braun, Michal K; Hinderhofer, Alexander; Zhang, Fajun; Jacobs, Robert M J; Skoda, Maximilian W A; Hansen-Goos, Hendrik; Roth, Roland; Schreiber, Frank

2017-12-01

Protein adsorption at the solid-liquid interface is an important phenomenon that often can be observed as a first step in biological processes. Despite its inherent importance, still relatively little is known about the underlying microscopic mechanisms. Here, using multivalent ions, we demonstrate the control of the interactions and the corresponding adsorption of net-negatively charged proteins (bovine serum albumin) at a solid-liquid interface. This is demonstrated by ellipsometry and corroborated by neutron reflectivity and quartz-crystal microbalance experiments. We show that the reentrant condensation observed within the rich bulk phase behavior of the system featuring a nonmonotonic dependence of the second virial coefficient on salt concentration c_{s} is reflected in an intriguing way in the protein adsorption d(c_{s}) at the interface. Our findings are successfully described and understood by a model of ion-activated patchy interactions within the framework of the classical density functional theory. In addition to the general challenge of connecting bulk and interface behavior, our work has implications for, inter alia, nucleation at interfaces.

Multivalent-Ion-Activated Protein Adsorption Reflecting Bulk Reentrant Behavior

NASA Astrophysics Data System (ADS)

Fries, Madeleine R.; Stopper, Daniel; Braun, Michal K.; Hinderhofer, Alexander; Zhang, Fajun; Jacobs, Robert M. J.; Skoda, Maximilian W. A.; Hansen-Goos, Hendrik; Roth, Roland; Schreiber, Frank

2017-12-01

Protein adsorption at the solid-liquid interface is an important phenomenon that often can be observed as a first step in biological processes. Despite its inherent importance, still relatively little is known about the underlying microscopic mechanisms. Here, using multivalent ions, we demonstrate the control of the interactions and the corresponding adsorption of net-negatively charged proteins (bovine serum albumin) at a solid-liquid interface. This is demonstrated by ellipsometry and corroborated by neutron reflectivity and quartz-crystal microbalance experiments. We show that the reentrant condensation observed within the rich bulk phase behavior of the system featuring a nonmonotonic dependence of the second virial coefficient on salt concentration cs is reflected in an intriguing way in the protein adsorption d (cs) at the interface. Our findings are successfully described and understood by a model of ion-activated patchy interactions within the framework of the classical density functional theory. In addition to the general challenge of connecting bulk and interface behavior, our work has implications for, inter alia, nucleation at interfaces.

Laser characterization of the depth profile of complex refractive index of PMMA implanted with 50 keV silicon ions

NASA Astrophysics Data System (ADS)

Stefanov, Ivan L.; Stoyanov, Hristiyan Y.; Petrova, Elitza; Russev, Stoyan C.; Tsutsumanova, Gichka G.; Hadjichristov, Georgi B.

2013-03-01

The depth profile of the complex refractive index of silicon ion (Si+) implanted polymethylmethacrylate (PMMA) is studied, in particular PMMA implanted with Si+ ions accelerated to a relatively low energy of 50 keV and at a fluence of 3.2 × 1015 cm-2. The ion-modified material with nano-clustered structure formed in the near(sub)surface layer of a thickness of about 100 nm is optically characterized by simulation based on reflection ellipsometry measurements at a wavelength of 632.8 nm (He-Ne laser). Being of importance for applications of ion-implanted PMMA in integrated optics, optoelectronics and optical communications, the effect of the index depth profile of Si+-implanted PMMA on the profile of the reflected laser beam due to laser-induced thermo-lensing in reflection is also analyzed upon illumination with a low power cw laser (wavelength 532 nm, optical power 10 - 50 mW).

Method and apparatus for ultrasonic characterization through the thickness direction of a moving web

DOEpatents

Jackson, Theodore; Hall, Maclin S.

2001-01-01

A method and apparatus for determining the caliper and/or the ultrasonic transit time through the thickness direction of a moving web of material using ultrasonic pulses generated by a rotatable wheel ultrasound apparatus. The apparatus includes a first liquid-filled tire and either a second liquid-filled tire forming a nip or a rotatable cylinder that supports a thin moving web of material such as a moving web of paper and forms a nip with the first liquid-filled tire. The components of ultrasonic transit time through the tires and fluid held within the tires may be resolved and separately employed to determine the separate contributions of the two tire thicknesses and the two fluid paths to the total path length that lies between two ultrasonic transducer surfaces contained within the tires in support of caliper measurements. The present invention provides the benefit of obtaining a transit time and caliper measurement at any point in time as a specimen passes through the nip of rotating tires and eliminates inaccuracies arising from nonuniform tire circumferential thickness by accurately retaining point-to-point specimen transit time and caliper variation information, rather than an average obtained through one or more tire rotations. Morever, ultrasonic transit time through the thickness direction of a moving web may be determined independent of small variations in the wheel axle spacing, tire thickness, and liquid and tire temperatures.

Zinc Leaching from Tire Crumb Rubber

NASA Astrophysics Data System (ADS)

Rhodes, E. P.; Ren, J.; Mays, D. C.

2010-12-01

Recent estimates indicate that more than 2 billion scrap tires are currently stockpiled in the United States and approximately 280 million more tires are added annually. Various engineering applications utilize recycled tires in the form of shredded tire crumb rubber. However, the use of tire crumb rubber may have negative environmental impacts, especially when the rubber comes into contact with water. A review of the literature indicates that leaching of zinc from tire crumb rubber is the most significant water quality concern associated with using this material. Zinc is generally used in tire manufacturing, representing approximately 1.3% of the final product by mass. This study will report results from the U.S. Environmental Protection Agency’s (EPA’s) Synthetic Precipitation Leaching Procedure, batch leaching tests, and column leaching tests performed to quantify the process by which zinc leaches from tire crumb rubber into water. Results are interpreted with a first-order kinetic attachment/detachment model, implemented with the U.S. Agricultural Research Service software HYDRUS-1D, in order to determine the circumstances when zinc leaching from tire crumb rubber would be expected to comply with the applicable discharge limits. One potential application for recycled tires is replacing sand with tire crumb rubber in granular media filters used for stormwater pollution control. For this to be a viable application, the total zinc in the stormwater discharge must be below the EPA’s benchmark value of 0.117 mg/L.

A Strain-Based Method to Detect Tires’ Loss of Grip and Estimate Lateral Friction Coefficient from Experimental Data by Fuzzy Logic for Intelligent Tire Development

PubMed Central

Garcia-Pozuelo, Daniel; Diaz, Vicente; Olatunbosun, Oluremi

2018-01-01

Tires are a key sub-system of vehicles that have a big responsibility for comfort, fuel consumption and traffic safety. However, current tires are just passive rubber elements which do not contribute actively to improve the driving experience or vehicle safety. The lack of information from the tire during driving gives cause for developing an intelligent tire. Therefore, the aim of the intelligent tire is to monitor tire working conditions in real-time, providing useful information to other systems and becoming an active system. In this paper, tire tread deformation is measured to provide a strong experimental base with different experiments and test results by means of a tire fitted with sensors. Tests under different working conditions such as vertical load or slip angle have been carried out with an indoor tire test rig. The experimental data analysis shows the strong relation that exists between lateral force and the maximum tensile and compressive strain peaks when the tire is not working at the limit of grip. In the last section, an estimation system from experimental data has been developed and implemented in Simulink to show the potential of strain sensors for developing intelligent tire systems, obtaining as major results a signal to detect tire’s loss of grip and estimations of the lateral friction coefficient. PMID:29415513

26 CFR 48.4071-4 - Original equipment tires on imported articles.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Original equipment tires on imported articles..., Tread Rubber, and Taxable Fuel Tires, Tubes, and Tread Rubber § 48.4071-4 Original equipment tires on... than bicycle tires and inner tubes) that are original equipment for an imported article upon which no...

30 CFR 56.14104 - Tire repairs.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tire repairs. 56.14104 Section 56.14104 Mineral... Devices and Maintenance Requirements § 56.14104 Tire repairs. (a) Before a tire is removed from a vehicle for tire repair, the valve core shall be partially removed to allow for gradual deflation and then...

40 CFR 63.5996 - How do I demonstrate initial compliance with the emission limits for tire production affected...

Code of Federal Regulations, 2010 CFR

2010-07-01

... with the emission limits for tire production affected sources? 63.5996 Section 63.5996 Protection of... Pollutants: Rubber Tire Manufacturing Testing and Initial Compliance Requirements for Tire Production Affected Sources § 63.5996 How do I demonstrate initial compliance with the emission limits for tire...

30 CFR 57.14104 - Tire repairs.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tire repairs. 57.14104 Section 57.14104 Mineral... Devices and Maintenance Requirements § 57.14104 Tire repairs. (a) Before a tire is removed from a vehicle for tire repair, the valve core shall be partially removed to allow for gradual deflation and then...

49 CFR 573.10 - Reporting the sale or lease of defective or noncompliant tires.

Code of Federal Regulations, 2010 CFR

2010-10-01

... noncompliant tires. 573.10 Section 573.10 Transportation Other Regulations Relating to Transportation... noncompliant tires. (a) Reporting requirement. Subject to paragraph (b) of this section, any person who knowingly and willfully sells or leases for use on a motor vehicle a defective tire or a tire that is not...

40 CFR 202.23 - Visual tire inspection.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Visual tire inspection. 202.23 Section... Visual tire inspection. No motor carrier subject to these regulations shall at any time operate any motor vehicle of a type to which this regulation is applicable on a tire or tires having a tread pattern which...

49 CFR 574.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... retreader bearing the licensor's brand name. (5) Tire purchaser means a person who buys or leases a new tire, or who buys or leases for 60 days or more a motor vehicle containing a new tire for purposes other..., with respect to a tire distributor or dealer, one whose business is not owned or controlled by a tire...

78 FR 54369 - The Goodyear Tire & Rubber Company, Mootness of Petition for Decision of Inconsequential...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-03

... subject tires meet or exceed all applicable FMVSS performance standards for a tire labeled as either load...-0107; Notice 2] The Goodyear Tire & Rubber Company, Mootness of Petition for Decision of... Petition Mootness. SUMMARY: The Goodyear Tire & Rubber Company (Goodyear),\\1\\ has determined that certain...

Method of sections in analytical calculations of pneumatic tires

NASA Astrophysics Data System (ADS)

Tarasov, V. N.; Boyarkina, I. V.

2018-01-01

Analytical calculations in the pneumatic tire theory are more preferable in comparison with experimental methods. The method of section of a pneumatic tire shell allows to obtain equations of intensities of internal forces in carcass elements and bead rings. Analytical dependencies of intensity of distributed forces have been obtained in tire equator points, on side walls (poles) and pneumatic tire bead rings. Along with planes in the capacity of secant surfaces cylindrical surfaces are used for the first time together with secant planes. The tire capacity equation has been obtained using the method of section, by means of which a contact body is cut off from the tire carcass along the contact perimeter by the surface which is normal to the bearing surface. It has been established that the Laplace equation for the solution of tasks of this class of pneumatic tires contains two unknown values that requires the generation of additional equations. The developed computational schemes of pneumatic tire sections and new equations allow to accelerate the pneumatic tire structure improvement process during engineering.

A Strain-Based Method to Estimate Slip Angle and Tire Working Conditions for Intelligent Tires Using Fuzzy Logic

PubMed Central

Garcia-Pozuelo, Daniel; Yunta, Jorge; Olatunbosun, Oluremi; Yang, Xiaoguang; Diaz, Vicente

2017-01-01

Tires equipped with sensors, the so-called “intelligent tires”, can provide vital information for control systems, drivers and external users. In this research, tire dynamic strain characteristics in cornering conditions are collected and analysed in relation to the variation of tire working conditions, such as inflation pressure, rolling speed, vertical load and slip angle. An experimental tire strain-based prototype and an indoor tire test rig are used to demonstrate the suitability of strain sensors to establish relations between strain data and lateral force. The results of experiments show that strain values drop sharply when lateral force is decreasing, which can be used to predict tire slip conditions. As a first approach to estimate some tire working conditions, such as the slip angle and vertical load, a fuzzy logic method has been developed. The simulation and test results confirm the feasibility of strain sensors and the proposed computational model to solve the non-linearity characteristics of the tires’ parameters and turn tires into a source of useful information. PMID:28420156

Optical constants of electroplated gold from spectroscopic ellipsometry

NASA Astrophysics Data System (ADS)

Synowicki, R. A.; Herzinger, Craig M.; Hall, James T.; Malingowski, Andrew

2017-11-01

The optical constants of an opaque electroplated gold film (Laser Gold from Epner Technology Inc.), were determined by spectroscopic ellipsometry at room temperature over the spectral range from 0.142 μm in the vacuum ultraviolet to 36 μm in the infrared (photon energy range 0.034-8.75 eV). Data from two separate ellipsometer instruments covering different spectral ranges were analyzed simultaneously. The optical constants n&k or ε1&ε2 were determined by fitting an oscillator dispersion model combining Drude, Gaussian, and Sellmeier dispersion functions to the experimental Ψ and Δ data. The data were analyzed using both an ideal bulk substrate model and a simple overlayer model to account for surface roughness. Including the optical surface roughness layer improved ellipsometric data fits in the UV, and using a separate Drude function for the surface layer improved fits in the infrared. The surface roughness was also characterized using an Atomic Force Microscope. Using an oscillator dispersion model for the optical constants determined in this work allows for more realistic extrapolation to longer infrared wavelengths. Extending optical constants out to 50 μm and beyond is important for calibrating far-infrared reflectance measurements. Applications include understanding the thermal performance of cryogenic space-based instruments, such as the James Webb Space Telescope (JWST).

O-6 Optical Property Degradation of the Hubble Space Telescope's Wide Field Camera-2 Pick Off Mirror

NASA Technical Reports Server (NTRS)

McNamara, Karen M.; Hughes, D. W.; Lauer, H. V.; Burkett, P. J.; Reed, B. B.

2011-01-01

Degradation in the performance of optical components can be greatly affected by exposure to the space environment. Many factors can contribute to such degradation including surface contaminants; outgassing; vacuum, UV, and atomic oxygen exposure; temperature cycling; or combinations of parameters. In-situ observations give important clues to degradation processes, but there are relatively few opportunities to correlate those observations with post-flight ground analyses. The return of instruments from the Hubble Space Telescope (HST) after its final servicing mission in May 2009 provided such an opportunity. Among the instruments returned from HST was the Wide-Field Planetary Camera-2 (WFPC-2), which had been exposed to the space environment for 16 years. This work focuses on the identifying the sources of degradation in the performance of the Pick-off mirror (POM) from WFPC-2. Techniques including surface reflectivity measurements, spectroscopic ellipsometry, FTIR (and ATR-FTIR) analyses, SEM/EDS, X-ray photoelectron spectroscopy (XPS) with and without ion milling, and wet and dry physical surface sampling were performed. Destructive and contact analyses took place only after completion of the non-destructive measurements. Spectroscopic ellipsometry was then repeated to determine the extent of contaminant removal by the destructive techniques, providing insight into the nature and extent of polymerization of the contaminant layer.

Tire traces - discrimination and classification of pyrolysis-GC/MS profiles.

PubMed

Gueissaz, Line; Massonnet, Geneviève

2013-07-10

Tire traces can be observed on several crime scenes as vehicles are often used by criminals. The tread abrasion on the road, while braking or skidding, leads to the production of small rubber particles which can be collected for comparison purposes. This research focused on the statistical comparison of Py-GC/MS profiles of tire traces and tire treads. The optimisation of the analytical method was carried out using experimental designs. The aim was to determine the best pyrolysis parameters regarding the repeatability of the results. Thus, the pyrolysis factor effect could also be calculated. The pyrolysis temperature was found to be five time more important than time. Finally, a pyrolysis at 650°C during 15s was selected. Ten tires of different manufacturers and models were used for this study. Several samples were collected on each tire, and several replicates were carried out to study the variability within each tire (intravariability). More than eighty compounds were integrated for each analysis and the variability study showed that more than 75% presented a relative standard deviation (RSD) below 5% for the ten tires, thus supporting a low intravariability. The variability between the ten tires (intervariability) presented higher values and the ten most variant compounds had a RSD value above 13%, supporting their high potential of discrimination between the tires tested. Principal Component Analysis (PCA) was able to fully discriminate the ten tires with the help of the first three principal components. The ten tires were finally used to perform braking tests on a racetrack with a vehicle equipped with an anti-lock braking system. The resulting tire traces were adequately collected using sheets of white gelatine. As for tires, the intravariability for the traces was found to be lower than the intervariability. Clustering methods were carried out and the Ward's method based on the squared Euclidean distance was able to correctly group all of the tire traces replicates in the same cluster than the replicates of their corresponding tire. Blind tests on traces were performed and were correctly assigned to their tire source. These results support the hypothesis that the tested tires, of different manufacturers and models, can be discriminated by a statistical comparison of their chemical profiles. The traces were found to be not differentiable from their source but differentiable from all the other tires present in the subset. The results are promising and will be extended on a larger sample set. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Effects of tire leachate on the invasive mosquito Aedes albopictus and the native congener Aedes triseriatus.

PubMed

Villena, Oswaldo C; Terry, Ivana; Iwata, Kayoko; Landa, Edward R; LaDeau, Shannon L; Leisnham, Paul T

2017-01-01

Discarded vehicle tire casings are an important artificial habitat for the developmental stages of numerous vector mosquitoes. Discarded vehicle tires degrade under ultraviolet light and leach numerous soluble metals (e.g., barium, cadmium, zinc) and organic substances (e.g., benzothiazole and its derivatives [BZTs], polyaromatic hydrocarbons [PAHs]) that could affect mosquito larvae that inhabit the tire casing. This study examined the relationship between soluble zinc, a common marker of tire leachate, on mosquito densities in tire habitats in the field, and tested the effects of tire leachate on the survival and development of newly hatched Aedes albopictus and Aedes triseriatus larvae in a controlled laboratory dose-response experiment. In the field, zinc concentrations were as high as 7.26 mg/L in a single tire and averaged as high as 2.39 (SE ± 1.17) mg/L among tires at a single site. Aedes albopictus (37/42 tires, 81.1%) and A. triseriatus (23/42, 54.8%) were the most widespread mosquito species, co-occurred in over half (22/42, 52.4%) of all tires, and A. triseriatus was only collected without A. albopictus in one tire. Aedes triseriatus was more strongly negatively associated with zinc concentration than A. albopictus, and another common mosquito, C. pipiens, which was found in 17 tires. In the laboratory experiment, A. albopictus per capita rate of population change ( λ ') was over 1.0, indicating positive population growth, from 0-8.9 mg/L zinc concentration (0-10,000 mg/L tire leachate), but steeply declined to zero from 44.50-89.00 mg/L zinc (50,000-100,000 mg/L tire leachate). In contrast, A. triseriatus λ ' declined at the lower concentration of 0.05 mg/L zinc (100 mg/L tire leachate), and was zero at 0.45, 8.90, 44.50, and 89.00 mg/L zinc (500, 10,000, 50,000 and 100,000 mg/L tire leachate). These results indicate that tire leachate can have severe negative effects on populations of container-utilizing mosquitoes at concentrations commonly found in the field. Superior tolerance to tire leachate of A. albopictus compared to A. triseriatus, and possibly other native mosquito species, may have facilitated the replacement of these native species as A. albopictus has invaded North America and other regions around the world.

Effects of tire leachate on the invasive mosquito Aedes albopictus and the native congener Aedes triseriatus

PubMed Central

Villena, Oswaldo C.; Terry, Ivana; Iwata, Kayoko; Landa, Edward R.; LaDeau, Shannon L.

2017-01-01

Discarded vehicle tire casings are an important artificial habitat for the developmental stages of numerous vector mosquitoes. Discarded vehicle tires degrade under ultraviolet light and leach numerous soluble metals (e.g., barium, cadmium, zinc) and organic substances (e.g., benzothiazole and its derivatives [BZTs], polyaromatic hydrocarbons [PAHs]) that could affect mosquito larvae that inhabit the tire casing. This study examined the relationship between soluble zinc, a common marker of tire leachate, on mosquito densities in tire habitats in the field, and tested the effects of tire leachate on the survival and development of newly hatched Aedes albopictus and Aedes triseriatus larvae in a controlled laboratory dose-response experiment. In the field, zinc concentrations were as high as 7.26 mg/L in a single tire and averaged as high as 2.39 (SE ± 1.17) mg/L among tires at a single site. Aedes albopictus (37/42 tires, 81.1%) and A. triseriatus (23/42, 54.8%) were the most widespread mosquito species, co-occurred in over half (22/42, 52.4%) of all tires, and A. triseriatus was only collected without A. albopictus in one tire. Aedes triseriatus was more strongly negatively associated with zinc concentration than A. albopictus, and another common mosquito, C. pipiens, which was found in 17 tires. In the laboratory experiment, A. albopictus per capita rate of population change (λ′) was over 1.0, indicating positive population growth, from 0–8.9 mg/L zinc concentration (0–10,000 mg/L tire leachate), but steeply declined to zero from 44.50–89.00 mg/L zinc (50,000–100,000 mg/L tire leachate). In contrast, A. triseriatus λ′ declined at the lower concentration of 0.05 mg/L zinc (100 mg/L tire leachate), and was zero at 0.45, 8.90, 44.50, and 89.00 mg/L zinc (500, 10,000, 50,000 and 100,000 mg/L tire leachate). These results indicate that tire leachate can have severe negative effects on populations of container-utilizing mosquitoes at concentrations commonly found in the field. Superior tolerance to tire leachate of A. albopictus compared to A. triseriatus, and possibly other native mosquito species, may have facilitated the replacement of these native species as A. albopictus has invaded North America and other regions around the world. PMID:28890855

Tire-to-Surface Friction Especially Under Wet Conditions

NASA Technical Reports Server (NTRS)

Sawyer, Richard H.; Batterson, Sidney A.; Harrin, Eziaslav N.

1959-01-01

The results of measurements of the maximum friction available in braking on various runway surfaces under various conditions is shown for a C-123B airplane and comparisons of measurements with a tire-friction cart on the same runways are made. The.results of studies of wet-surface friction made with a 12-inch-diameter low-pressure tire on a tire-friction treadmill, with an automobile tire on the tire-friction cart, and with a 44 x 13 extra-high-pressure type VII aircraft tire at the Langley landing-loads track are compared. Preliminary results of tests on the tire-friction treadmill under wet-surface conditions to determine the effect of the wiping action of the front wheel of a tandem-wheel arrangement on the friction available in braking for the rear wheel are given.

Optical Physics of Cu(In,Ga)Se2 Solar Cells and Their Layer Components

NASA Astrophysics Data System (ADS)

Ibdah, Abedl-Rahman

Polycrystalline Cu(In1-xGax)Se 2 (CIGS) thin film technology has emerged as a promising candidate for low cost and high performance solar modules. The efficiency of CIGS solar cells is strongly influenced by several key factors. Among these factors include Ga composition and its profile in the absorber layer, copper content in this layer, and the solar cell multilayer structure. As a result, tools for the characterization of thin film CIGS solar cells and their layer components are becoming increasingly essential in research and manufacturing. Spectroscopic ellipsometry is a non-invasive technique that can serve as an accurate probe of component layer optical properties and multilayer structures, and can be applied as a diagnostic tool for real-time, in-line, and off-line monitoring and analysis in small area solar cell fabrication as well as in large area photovoltaics manufacturing. Implementation of spectroscopic ellipsometry provides unique insights into the properties of complete solar cell multilayer structures and their layer components. These insights can improve our understanding of solar cell structures, overcome challenges associated with solar cell fabrication, and assist in process monitoring and control on a production line. In this dissertation research, Cu(In,Ga)Se2 films with different Cu contents have been prepared by the one stage co-evaporation process. These films have been studied by real time spectroscopic ellipsometry (RTSE) during deposition, and by in-situ SE at the deposition temperature as well as at room temperature to extract the dielectric functions (epsilon1, epsilon 2) of the thin film materials. Analytical expressions for the room temperature dielectric functions were developed, and the free parameters that describe these analytical functions were in turn expressed as functions of the Cu content. As a result of this parameterization, the dielectric function spectra (epsilon 1, epsilon2) can be predicted for any desired composition within the range of the samples investigated. This capability was applied for mapping the structural and compositional variations of CIGS thin films deposited over a 10 cm x 10 cm substrate area. In another application presented in this dissertation, a non-invasive method utilizing ex-situ spectroscopic ellipsometry analysis has been developed and applied to determine non-destructively the Ga compositional profile in CIGS absorbers. The method employs parameterized dielectric function spectra (epsilon1, epsilon2) of CIGS versus Ga content to probe the compositional variation with depth into the absorber. In addition, a methodology for prediction of the external quantum efficiency (QE) including optical gains and losses for a CIGS solar cell has been developed. The methodology utilizes ex-situ spectroscopic ellipsometry analysis of a complete solar cell, with no free parameters, to deduce the multilayer solar cell structure non-invasively and simulate optical light absorption in each of the layer components. In the case of high efficiency CIGS solar cells, with minimal electronic losses, QE spectra are predicted from the sum of optical absorption in the active layer components. For such solar cells with ideal photo-generated charge carrier collection, the SE-predicted QE spectra are excellent representation of the measured ones. Since the QE spectra as well as the short circuit current density (Jsc) can be calculated directly from SE analysis results, then the predicted QE from SE can be compared with the experimental QE to evaluate electronic losses based on the difference between the spectra. Moreover, the calculated Jsc can be used as a key parameter for the design and optimization of anti-reflection coating structures. Because the long term production potential of CIGS solar modules may be limited by the availability of indium, it becomes important to reduce the thickness of the CIGS absorber layer. Thickness reduction would reduce the quantity of indium required for production which would in turn reduce costs. A decrease in short-circuit current density (Jsc) is expected, however, upon thinning the CIGS absorber due to incomplete absorption. To clarify the limits of obtainable Jsc in ultra-thin CIGS solar cells with Mo back contacts, optical properties and multilayer structural data are deduced via spectroscopic ellipsometry analysis and used to predict the QE spectra and maximum obtainable Jsc values upon thinning the absorber. Moreover, SE-guided optical design of ultra-thin CIGS solar cells has been demonstrated. In the case of solar cells fabricated on Mo, thinning the absorber in a CIGS solar cell is associated with significant optical losses in the Mo containing back contact layers. This is due in part to the poor optical reflectance of Mo. Such optical losses may be reduced by employing a back contact design with improved reflectance. Thus, alternative novel solar cell structures with ultra-thin absorbers and improved back contact reflectance have been designed and investigated using SE and the optical modeling methods. In addition to optical losses, electronic losses in the ultra-thin solar cells have been evaluated. By separating the absorber layer into sub-layer regions (for example, near-junction, bulk, and near-back-contact) and varying carrier collection probability in these regions, the contribution of each region to the current can be estimated. Based on this separation, the origin of the electronic losses has been identified as near the back contact.

Construction of a test embankment using a sand-tire shred mixture as fill material.

PubMed

Yoon, Sungmin; Prezzi, Monica; Siddiki, Nayyar Zia; Kim, Bumjoo

2006-01-01

Use of tire shreds in construction projects, such as highway embankments, is becoming an accepted way of beneficially recycling scrap tires. However, in the last decade there was a decline in the use of pure tire shreds as fill materials in embankment construction, as they are susceptible to fire hazards due to the development of exothermic reactions. Tire shred-sand mixtures, on the other hand, were found to be effective in inhibiting exothermic reactions. When compared with pure tire shreds, tire shred-sand mixtures are less compressible and have higher shear strength. However, the literature contains limited information on the use of tire shred-soil mixtures as a fill material. The objectives of this paper are to discuss and evaluate the feasibility of using tire shred-sand mixtures as a fill material in embankment construction. A test embankment constructed using a 50/50 mixture, by volume, of tire shreds and sand was instrumented and monitored to: (a) determine total and differential settlements; (b) evaluate the environmental impact of the embankment construction on the groundwater quality due to leaching of fill material; and (c) study the temperature variation inside the embankment. The findings in this research indicate that mixtures of tire shreds and sand are viable materials for embankment construction.

Measurements of Flow Rate and Trajectory of Aircraft Tire-Generated Water Spray

NASA Technical Reports Server (NTRS)

Daugherty, Robert H.; Stubbs, Sandy M.

1987-01-01

An experimental investigation was conducted at the NASA Langley Research Center to measure the flow rate and trajectory of water spray generated by an aircraft tire operating on a flooded runway. Tests were conducted in the Hydrodynamics Research Facility and made use of a partial airframe and a nose tire from a general aviation aircraft. Nose tires from a commercial transport aircraft were also used. The effects of forward speed, tire load, and water depth on water spray patterns were evaluated by measuring the amount and location of water captured by an array of tubes mounted behind the test tire. Water ejected from the side of the tire footprint had the most significant potential for ingestion into engine inlets. A lateral wake created on the water surface by the rolling tire can dominate the shape of the spray pattern as the distance aft of the tire is increased. Forward speed increased flow rates and moved the spray pattern inboard. Increased tire load caused the spray to become less dense. Near the tire, increased water depths caused flow rates to increase. Tests using a fuselage and partial wing along with the nose gear showed that for certain configurations, wing aerodynamics can cause a concentration of spray above the wing.

40 CFR 63.5987 - What are my alternatives for meeting the emission limits for tire cord production affected sources?

Code of Federal Regulations, 2010 CFR

2010-07-01

... the emission limits for tire cord production affected sources? 63.5987 Section 63.5987 Protection of... Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Cord Production Affected Sources § 63.5987 What are my alternatives for meeting the emission limits for tire cord production affected sources? You...

41 CFR 101-25.110-3 - Tires accompanying new motor vehicles.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Tires accompanying new...-GENERAL 25.1-General Policies § 101-25.110-3 Tires accompanying new motor vehicles. The tire... vehicle manufacturer or his designee to maintain a record of tires on or in each vehicle shipped by him...

40 CFR 63.5999 - How do I demonstrate initial compliance with the emission limits for tire cord production...

Code of Federal Regulations, 2010 CFR

2010-07-01

... with the emission limits for tire cord production affected sources? 63.5999 Section 63.5999 Protection... Pollutants: Rubber Tire Manufacturing Testing and Initial Compliance Requirements for Tire Cord Production Affected Sources § 63.5999 How do I demonstrate initial compliance with the emission limits for tire cord...

40 CFR 63.5981 - Am I subject to this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... subject to this subpart? (a) You are subject to this subpart if you own or operate a rubber tire..., such as wheels, inner tubes, tire bladders, and valve stems, are not components of rubber tires or tire... more per year. (b) You are not subject to this subpart if the affected source at your rubber tire...

78 FR 43967 - Mercedes-Benz USA, LLC, on Behalf of Daimler AG, Grant of Petition for Decision of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-22

... Federal Motor Vehicle Safety Standard (FMVSS) No. 110, Tire selection and rims and motor home/recreation... affixed to the driver's side B-pillar.* * * (b) Tire size designation, indicated by the headings ``size'' or ``original tire size'' or ``original size,'' and ``spare tire'' or ``spare,'' for the tires...

49 CFR 229.75 - Wheels and tire defects.

Code of Federal Regulations, 2010 CFR

2010-10-01

... crack or break in the flange, tread, rim, plate, or hub. (l) A loose wheel or tire. (m) Fusion welding... 49 Transportation 4 2010-10-01 2010-10-01 false Wheels and tire defects. 229.75 Section 229.75....75 Wheels and tire defects. Wheels and tires may not have any of the following conditions: (a) A...

49 CFR 229.75 - Wheels and tire defects.

Code of Federal Regulations, 2012 CFR

2012-10-01

... crack or break in the flange, tread, rim, plate, or hub. (l) A loose wheel or tire. (m) Fusion welding... 49 Transportation 4 2012-10-01 2012-10-01 false Wheels and tire defects. 229.75 Section 229.75....75 Wheels and tire defects. Wheels and tires may not have any of the following conditions: (a) A...

49 CFR 229.75 - Wheels and tire defects.

Code of Federal Regulations, 2011 CFR

2011-10-01

... crack or break in the flange, tread, rim, plate, or hub. (l) A loose wheel or tire. (m) Fusion welding... 49 Transportation 4 2011-10-01 2011-10-01 false Wheels and tire defects. 229.75 Section 229.75....75 Wheels and tire defects. Wheels and tires may not have any of the following conditions: (a) A...

49 CFR 229.75 - Wheels and tire defects.

Code of Federal Regulations, 2014 CFR

2014-10-01

... crack or break in the flange, tread, rim, plate, or hub. (l) A loose wheel or tire. (m) Fusion welding... 49 Transportation 4 2014-10-01 2014-10-01 false Wheels and tire defects. 229.75 Section 229.75....75 Wheels and tire defects. Wheels and tires may not have any of the following conditions: (a) A...

49 CFR 229.75 - Wheels and tire defects.

Code of Federal Regulations, 2013 CFR

2013-10-01

... crack or break in the flange, tread, rim, plate, or hub. (l) A loose wheel or tire. (m) Fusion welding... 49 Transportation 4 2013-10-01 2013-10-01 false Wheels and tire defects. 229.75 Section 229.75....75 Wheels and tire defects. Wheels and tires may not have any of the following conditions: (a) A...

75 FR 846 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Partial Rescission...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-06

...-the-Road Tires From the People's Republic of China: Partial Rescission of Countervailing Duty... the countervailing duty order on Certain New Pneumatic Off-the-Road Tires (OTR Tires) from the People... to the following six companies: 1. Aeolus Tyre Co. Ltd. (Aeolus) 2. Guizhou Tire Co. Ltd. (GTC) 3...

Static Footprint Local Forces, Areas, and Aspect Ratios for Three Type 7 Aircraft Tires

NASA Technical Reports Server (NTRS)

Howell, William E.; Perez, Sharon E.; Vogler, William A.

1991-01-01

The National Tire Modeling Program (NTMP) is a joint NASA/industry effort to improve the understanding of tire mechanics and develop accurate analytical design tools. This effort includes fundamental analytical and experimental research on the structural mechanics of tires. Footprint local forces, areas, and aspect ratios were measured. Local footprint forces in the vertical, lateral, and drag directions were measured with a special footprint force transducer. Measurements of the local forces in the footprint were obtained by positioning the transducer at specified locations within the footprint and externally loading the tires. Three tires were tested: (1) one representative of those used on the main landing gear of B-737 and DC-9 commercial transport airplanes, (2) a nose landing gear tire for the Space Shuttle Orbiter, and (3) a main landing gear tire for the Space Shuttle Orbiter. Data obtained for various inflation pressures and vertical loads are presented for two aircraft tires. The results are presented in graphical and tabulated forms.

A System to Measure Both Inner and Outer Car Tire Temperatures ``in situ''

NASA Astrophysics Data System (ADS)

Koštial, P.; Mokryšová, M.; Šišáková, J.; Mošková, Z.; Rusnáková, S.

2009-02-01

In the paper, a system for the complex analysis of the internal and external tire temperatures and pressure of sporty tires is presented. Tests were performed on the test circuit of a tire producer. The CTPA 05 measuring system (complex temperature-pressure analyzer) enables simultaneous measurements of the internal temperature and pressure in a passenger or sports tire. The experimentalist determines that the CTPA 05 can be used to measure independently the external temperature of the overcoat on the front wheel driving tires at three points. Measurements of both the internal tire temperature and pressure, as well as of the external tire temperature, are collected together with GPS (global position system) data. The system of measurement is fully automatic and contactless. The obtained results are in very good agreement with those obtained by independent methods.

Application of Novel Lateral Tire Force Sensors to Vehicle Parameter Estimation of Electric Vehicles.

PubMed

Nam, Kanghyun

2015-11-11

This article presents methods for estimating lateral vehicle velocity and tire cornering stiffness, which are key parameters in vehicle dynamics control, using lateral tire force measurements. Lateral tire forces acting on each tire are directly measured by load-sensing hub bearings that were invented and further developed by NSK Ltd. For estimating the lateral vehicle velocity, tire force models considering lateral load transfer effects are used, and a recursive least square algorithm is adapted to identify the lateral vehicle velocity as an unknown parameter. Using the estimated lateral vehicle velocity, tire cornering stiffness, which is an important tire parameter dominating the vehicle's cornering responses, is estimated. For the practical implementation, the cornering stiffness estimation algorithm based on a simple bicycle model is developed and discussed. Finally, proposed estimation algorithms were evaluated using experimental test data.

Investigation of Noise and Vibration in Tires Through Analytical Modeling, Tests and Simulations

NASA Astrophysics Data System (ADS)

Cao, Rui

Tire noise and vibration is an interesting topic, with more and more people paying attention to this issue. Tire noise can both propagate into the vehicle interior and radiate directly toward the immediate environment. Tire noise is not only related to vehicle passengers' comfort but also affects the residential or working area near highways, especially in high population density regions. The emerging electric vehicles also emphasize tires' role in vehicle Noise Vibration and Harshness (NVH) since power-train noises are significantly reduced. The study in this research focuses on the noise and vibration of tires from the low to high frequency range, typically from 60 kHz to 2 kHz. From the analytical point of view, forced vibration of a fully coupled 2D structural-acoustical model is presented and a 3D structural model is also investigated for various input conditions. Both circumferential and cross-sectional shearing motions in the analytical tire models can be observed. Static tire surface mobilities were also measured to verify the findings from the developed models. On the experimental side, the loading effect on tire noise radiation was studied, where applied loads ranged from 500 lbs to 1300 lbs. Results indicate that sound radiation is usually proportional to the loading, except between 1.1 kHz to 1.7 kHz where the load-noise relation is reversed. In addition, tire noise generated by road surface discontinuities was also studied experimentally. As expected, a broadband increase of the noise spectrum can be observed below 1 kHz compared to the noise on a continuous surface. However, the difference tends to diminish above 1 kHz except in a certain narrow frequency band depending on the particular tire tested. High frequency waves and motions in tire cross-sectional directions were identified as occurring in the frequency range of interest. A two-dimensional cross-sectional analytical tire model was proposed for further investigations, in order to verify the relation among high frequency tire noise properties and the fast propagating waves and cross-sectional motions in tires. Finally, a fully coupled finite element tire-wheel model was developed to simulate the tire deformation under static vertical loading and to explore the influence of various excitation forces. The forces or accelerations, depending on the boundary conditions, at the wheel center can be calculated from the tire model up to 500 Hz. The results can be potentially used as input for vehicle full body simulations, thus accelerating the optimization process of new product development.

Chevron cutting: Experiment with new runway mixtures

NASA Technical Reports Server (NTRS)

Tyran, K. (Compiler)

1978-01-01

Chevron cutting is shown to occur in different forms depending on the type of tire and the rubber on the running surface. Hardest wear is shown by the main tires of the B-747. Four defects occurred, in the form of two rip separation and two breakouts of the running surface. Tires capped by Thompson are more affected than any of the other rubber-capping fabrics. For Thompson tires, Chevron Cutting is greatly reduced with a fiberglass-rubber mixture. For Goodyear tires, it is eliminated with spiral wrap rubbercapping; resistance to damages through cuts seems to be more positive for Goodyear tires. For Mader tires, the extent of Chevron Cutting is generally smaller than for Thompson cappings.

Wheelbarrow tire explosion causing trauma to the forearm and hand: a case report

PubMed Central

2009-01-01

Introduction Tire explosion injuries are rare, but they may result in a severe injury pattern. Case reports and statistics from injuries caused by exploded truck tires during servicing are established, but trauma from exploded small tires seems to be unknown. Case presentation A 47-year-old german man inflated a wheelbarrow tire. The tire exploded during inflation and caused an open, multiple forearm and hand injury. Conclusion Even small tires can cause severe injury patterns in the case of an explosion. High inflating pressures and low safety distances are the main factors responsible for this occurrence. Broad safety information and suitable filling devices are indispensable for preventing these occurrences. PMID:19946543

76 FR 7816 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Rescission of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-11

...-the-Road Tires From the People's Republic of China: Rescission of Countervailing Duty Administrative... countervailing duty order on certain new pneumatic off-the-road tires (OTR Tires) from the People's Republic of... withdrawal of its request for review. See Certain New Pneumatic Off-the-Road Tires From the People's Republic...

77 FR 10615 - Cooper Tire & Rubber Tire Company, Grant of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-22

... measurable effect on the safety of the tire retread, repair, and recycling industries. The use of steel cord... no effect of the noncompliances on the operational safety of the vehicles on which these tires are mounted. The safety of people working in the tire retread, repair, and recycling industries must also be...

Fore and aft elastic response characteristics of 34 x 9.9, type 7, 14 ply-rating aircraft tires of bias-ply, bias-belted, and radial-belted design. M.S. Thesis - George Washington Univ., May 1973; [static and rolling tests on dry concrete pavements

NASA Technical Reports Server (NTRS)

Tanner, J. A.

1974-01-01

An investigation was conducted to determine the fore-and-aft elastic response characteristics of 34 x 9.9, type VII, 14 ply-rating aircraft tires of bias-ply, bias-belted, and radial-belted design. The investigation consisted of static and rolling tests on dry concrete pavements at the Langley aircraft landing loads and traction facility; statistical techniques which related the measured tire elastic characteristics to variations in the vertical load, inflation pressure, braking force and/or tire vertical deflection; and a semiempirical analysis which related the tire elastic behavior to measured wheel slippage during steady-state braking. The bias-belted tire developed the largest spring constant value for most loading conditions; the radial-belted tire, the smallest. The elastic response of the tire free periphery to static braking included both tread stretch and carcass torsional wind-up about the axle for the bias-ply and bias-belted tires and carcass wind-up alone for the radial-belted tire.

Environmental labeling of car tires--toxicity to Daphnia magna can be used as a screening method.

PubMed

Wik, Anna; Dave, Göran

2005-02-01

Car tires contain several water-soluble compounds that can leach into water and have toxic effects on aquatic organisms. Due to tire wear, 10,000 tonnes of rubber particles end up along the Swedish roads every year. This leads to a diffuse input of emissions of several compounds. Emissions of polyaromatic hydrocarbons (PAHs) are of particular concern. PAHs are ingredients of the high aromatic oil (HA oil) that is used in the rubber as a softener and as a filler. The exclusion of HA oils from car tires has started, and an environmental labeling of tires could make HA oils obsolete. The toxicity to Daphnia magna from 12 randomly selected car tires was tested in this study. Rubber from the tread of the tires was grated into small pieces, to simulate material from tire wear, and the rubber was equilibrated with dilution water for 72 h before addition of test organisms. The 24-h EC50s of the rubber pieces ranged from 0.29 to 32 gl-1, and the 48-h EC50s ranged from 0.0625 to 2.41 gl-1. Summer tires were more toxic than winter tires. After the 48-h exposure, the daphnids were exposed to UV-light for 2 h, to determine if the tires contained compounds that were phototoxic. After UV-activation the EC50s ranged from 0.0625 to 0.38 gl-1. Four of the 12 tires had a very distinct photoactivation, with a toxicity increase of >10 times. This study has shown that the used method for toxicity testing with Daphnia magna according to ISO 6341 could be used as a basis for environmental labeling of car tires.

Underinflated tires in the United States

DOT National Transportation Integrated Search

2007-02-09

Underinflated tires impact a drivers ability to control a vehicle against skidding, blowouts, and other tire failures. While not a leading cause of highway accidents and fatalities, a NHTSA study shows that, in 1999, underinflated tires contribute...

Heat generation in aircraft tires under free rolling conditions

NASA Technical Reports Server (NTRS)

Clark, S. K.; Dodge, R. N.

1980-01-01

Effort is directed toward construction of a rational method for evaluating internal temperatures of aircraft tires. Enhanced predictability of tire temperature buildup is a design tool in both the tire and airframe industries.

Tire pressure special study : interview data

DOT National Transportation Integrated Search

2001-08-01

Although 85% of the population of drivers are : concerned about maintaining proper tire inflation in : their vehicles, only 25% use the correct method to : determine the manufacturers recommended tire : pressure for their tires. In addition, 43% o...

Thermal conductance of and heat generation in tire-pavement interface and effect on aircraft braking

NASA Technical Reports Server (NTRS)

Miller, C. D.

1976-01-01

A finite-difference analysis was performed on temperature records obtained from a free rolling automotive tire and from pavement surface. A high thermal contact conductance between tire and asphalt was found on a statistical basis. Average slip due to squirming between tire and asphalt was about 1.5 mm. Consequent friction heat was estimated as 64 percent of total power absorbed by bias-ply, belted tire. Extrapolation of results to aircraft tire indicates potential braking improvement by even moderate increase of heat absorbing capacity of runway surface.

Magneto-ellipsometry as a powerful technique for investigating magneto-optical structures properties

NASA Astrophysics Data System (ADS)

Maximova, Olga; Kosyrev, Nikolay; Yakovlev, Ivan; Shevtsov, Dmitriy; Lyaschenko, Sergey; Varnakov, Sergey; Ovchinnikov, Sergey

2017-10-01

In this work we report on new magneto-ellipsometry set-up that allows to grow thin films and nanostructures by ultrahigh vacuum thermal evaporation as well as to conduct in situ measurements during the growth in order to analyze and control nanostructures properties. Ellipsometry and transverse magneto-optical Kerr effect measurements can be performed in situ inside this set-up. A uniform magnetic field of high intensity (more than 1 kOe) can be applied to samples inside the vacuum chamber. Also, we report on the developed method of data interpretation that is the base of the set-up software. Thus, we present a powerful tool for nanostructures synthesis and characterization.

Demonstration of improved vehicle fuel efficiency through innovative tire design, materials, and weight reduction technologies

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

Donley, Tim

2014-12-31

Cooper completed an investigation into new tire technology using a novel approach to develop and demonstrate a new class of fuel efficient tires using innovative materials technology and tire design concepts. The objective of this work was to develop a new class of fuel efficient tires, focused on the “replacement market” that would improve overall passenger vehicle fuel efficiency by 3% while lowering the overall tire weight by 20%. A further goal of this project was to accomplish the objectives while maintaining the traction and wear performance of the control tire. This program was designed to build on what hasmore » already been accomplished in the tire industry for rolling resistance based on the knowledge and general principles developed over the past decades. Cooper’s CS4 (Figure #1) premium broadline tire was chosen as the control tire for this program. For Cooper to achieve the goals of this project, the development of multiple technologies was necessary. Six technologies were chosen that are not currently being used in the tire industry at any significant level, but that showed excellent prospects in preliminary research. This development was divided into two phases. Phase I investigated six different technologies as individual components. Phase II then took a holistic approach by combining all the technologies that showed positive results during phase one development.« less

Acute toxicity of leachates of tire wear material to Daphnia magna--variability and toxic components.

PubMed

Wik, Anna; Dave, Göran

2006-09-01

Large amounts of tire rubber are deposited along the roads due to tread wear. Several compounds may leach from the rubber and cause toxicity to aquatic organisms. To investigate the toxic effects of tire wear material from different tires, rubber was abraded from the treads of twenty-five tires. Leachates were prepared by allowing the rubber to equilibrate with dilution water at 44 degrees C for 72 h. Then the rubber was filtered from the leachates, and test organisms (Daphnia magna) were added. Forty-eight hour EC50s ranged from 0.5 to >10.0 g l(-1). The toxicity identification evaluation (TIE) indicated that non-polar organic compounds caused most of the toxicity. UV exposure of the filtered tire leachates caused no significant increase in toxicity. However, when tested as unfiltered leachates (the rubber was not filtered from the leachates before addition of D. magna) photo-enhanced toxicity was considerable for some tires, which means that test procedures are important when testing tire leachates for aquatic (photo) toxicity. The acute toxicity of tire wear for Daphnia magna was found to be <40 times a predicted environmental concentration based on reports on the concentration of a tire component found in environmental samples, which emphasizes the need for a more extensive risk assessment of tire wear for the environment.

Tests to Determine the Adhesive Power of Passenger-Car Tires

NASA Technical Reports Server (NTRS)

Foerster, B.

1956-01-01

The concept of the adhesive power of a tire with respect to the road involves several properties which result from the purpose of the tire; namely, connecting link between vehicle and road: (1) The tire must transfer the tractive and braking forces acting in the direction of travel (tractive and braking adhesion); (2) The tire is to prevent lateral deviations of the vehicle from the desired direction of travel (track adhesion). Moreover, the rubber tire provides part of the springing of the vehicle. Above all, it has to level out the minor road irregularities; thus it smoothes, as it were, the road and simultaneously reduces the noise of driving. The springing properties of the tire affect the adhesive power. The tests described below comprise a determination of the braking and track adhesion of individual tires. The adhesion of driven wheels has not been investigated so far.

Application of Novel Lateral Tire Force Sensors to Vehicle Parameter Estimation of Electric Vehicles

PubMed Central

Nam, Kanghyun

2015-01-01

This article presents methods for estimating lateral vehicle velocity and tire cornering stiffness, which are key parameters in vehicle dynamics control, using lateral tire force measurements. Lateral tire forces acting on each tire are directly measured by load-sensing hub bearings that were invented and further developed by NSK Ltd. For estimating the lateral vehicle velocity, tire force models considering lateral load transfer effects are used, and a recursive least square algorithm is adapted to identify the lateral vehicle velocity as an unknown parameter. Using the estimated lateral vehicle velocity, tire cornering stiffness, which is an important tire parameter dominating the vehicle’s cornering responses, is estimated. For the practical implementation, the cornering stiffness estimation algorithm based on a simple bicycle model is developed and discussed. Finally, proposed estimation algorithms were evaluated using experimental test data. PMID:26569246

76 FR 6603 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Notice of Extension...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-07

...-the-Road Tires From the People's Republic of China: Notice of Extension of Time Limit for the Final... review of the antidumping duty order on certain new pneumatic off-the-road tires (``OTR tires'') from the... of the administrative review of the antidumping order on OTR tires from the PRC. See Certain New...

76 FR 14906 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Notice of Extension...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-18

...-the-Road Tires From the People's Republic of China: Notice of Extension of Time Limit for the Final... review of the antidumping duty order on certain new pneumatic off-the-road tires (``OTR tires'') from the... of the administrative review of the antidumping order on OTR tires from the PRC. See Certain New...

26 CFR 48.4221-7 - Tax-free sales of tires and tubes.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Tax-free sales of tires and tubes. 48.4221-7... Tax-free sales of tires and tubes. (a) In general. A manufacturer of tires or inner tubes that are... articles taxable under section 4071 may be sold tax free: (1) The tire or tube is sold for use by the...

77 FR 6536 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Notice of Extension...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-08

...-the-Road Tires From the People's Republic of China: Notice of Extension of Time Limit for the Final... pneumatic off-the-road tires (``off-the-road tires'') from the People's Republic of China (``PRC'') for the... preliminary results of the administrative review of the antidumping order on off- the-road tires from the PRC...

Source Hierarchy List. Volume 2. E through N

DTIC Science & Technology

1994-07-01

SEE CONTINENTAL AG HANNOVER (GERMANY F R) 421628 02 GENERAL TIRE AND RUBBER CO MARION IN 151750 02 GENERAL TIRE ANO RUBBER CO WABASH IN...151800 03 GENERAL TIRE AND RUBBER CO WABASH IN 151820 INDUSTRIAL PRODUCTS DIV...GENERAL TIRE AND RUBBER CO WABASH IN 151800 FOR HIGHEST ORGANIZATIONAL LEVEL SEE CONTINENTAL AG HANNOVER (GERMANY F R) G3 GENERAL TIRE AND RUBBER CO

Leaching of DOC, DN, and inorganic constituents from scrap tires.

PubMed

Selbes, Meric; Yilmaz, Ozge; Khan, Abdul A; Karanfil, Tanju

2015-11-01

One concern for recycle and reuse of scrap tires is the leaching of tire constituents (organic and inorganic) with time, and their subsequent potential harmful impacts in environment. The main objective of this study was to examine the leaching of dissolved organic carbon (DOC), dissolved nitrogen (DN), and selected inorganic constituents from scrap tires. Different sizes of tire chips and crumb rubber were exposed to leaching solutions with pH's ranging from 3.0 to 10.0 for 28days. The leaching of DOC and DN were found to be higher for smaller size tire chips; however, the leaching of inorganic constituents was independent of the size. In general, basic pH conditions increased the leaching of DOC and DN, whereas acidic pH conditions led to elevated concentrations of metals. Leaching was minimal around the neutral pH values for all the monitored parameters. Analysis of the leaching rates showed that components associated with the rubbery portion of the tires (DOC, DN, zinc, calcium, magnesium, etc.) exhibited an initial rapid followed by a slow release. On the other hand, a constant rate of leaching was observed for iron and manganese, which are attributed to the metal wires present inside the tires. Although the total amounts that leached varied, the observed leaching rates were similar for all tire chip sizes and leaching solutions. Operation under neutral pH conditions, use of larger size tire chips, prewashing of tires, and removal of metal wires prior to application will reduce the impact of tire recycle and reuse. Copyright © 2015 Elsevier Ltd. All rights reserved.

Single-shot Ellipsometry of Shocked Iron to 275 GPa

NASA Astrophysics Data System (ADS)

Grant, Sean; Ao, Tommy; Bernstein, Aaron; Davis, Jean-Paul; Ditmire, Todd; Dolan, Daniel; Lin, Jung-Fu; Porwitzky, Andrew; Seagle, Christopher

2017-06-01

We have studied the properties of iron under shock conditions using time-resolved ellipsometry, a technique that probes the dielectric value of materials under dynamic conditions, on the STAR gas gun facility at Sandia National Laboratories. We performed experiments on a two-stage gas gun ranging from the α - ɛ transition (75 GPa) to the solid-liquid transition (275 GPa). For the first time, we report the dielectric results of shocked iron at those conditions. In addition, the time-resolved ellipsometry diagnostic is being implemented on the Sandia pulsed power Z-machine. The goal of upcoming Z experiments will be to employ the ``shock-ramp'' technique to reach pressure and temperature conditions relevant to the Earth core, and to use ellipsometry to obtain the iron electric conductivities needed for benchmarking material models. Sandia National Laboratories is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND2017-1952 A.

Effective electron mass and phonon modes in n-type hexagonal InN

NASA Astrophysics Data System (ADS)

Kasic, A.; Schubert, M.; Saito, Y.; Nanishi, Y.; Wagner, G.

2002-03-01

Infrared spectroscopic ellipsometry and micro-Raman scattering are used to study vibrational and electronic properties of high-quality hexagonal InN. The 0.22-μm-thick highly n-conductive InN film was grown on c-plane sapphire by radio-frequency molecular-beam epitaxy. Combining our results from the ellipsometry data analysis with Hall-effect measurements, the isotropically averaged effective electron mass in InN is determined as 0.14m0. The resonantly excited zone center E1 (TO) phonon mode is observed at 477 cm-1 in the ellipsometry spectra. Despite the high electron concentration in the film, a strong Raman mode occurs in the spectral range of the unscreened A1(LO) phonon. Because an extended carrier-depleted region at the sample surface can be excluded from the ellipsometry-model analysis, we assign this mode to the lower branch of the large-wave-vector LO-phonon-plasmon coupled modes arising from nonconserving wave-vector scattering processes. The spectral position of this mode at 590 cm-1 constitutes a lower limit for the unscreened A1(LO) phonon frequency.

Overview of NASA tire experimental programs

NASA Technical Reports Server (NTRS)

Tanner, J. A.

1983-01-01

Ongoing aircraft tire experimental programs are reported. These programs are designed to measure profile growth due to inflation pressure and vertical loading, contact pressures in the tire footprint, and a number of tire mechanical properties including spring, damping, and relaxation characteristics.

Tire bales in highway applications : feasibility and properties evaluation

DOT National Transportation Integrated Search

2005-03-01

There are growing interests in the utilization of recycled tire bales for civil engineering applications, triggered partly by the significant volumes of tires that could be disposed of in transportation projects. However, evaluation of tire bale prop...

Advanced sensors and applications : commercial motor vehicle tire pressure monitoring and maintenance : [technology brief].

DOT National Transportation Integrated Search

2014-04-01

Tire pressure monitoring and automatic tire inflation technologies show significant promise for improving safety and reducing costs in the commercial vehicle industry. Improved tire pressure management directly relates to improved vehicle stability, ...

Pyrolysis kinetics behavior of solid tire wastes available in Bangladesh.

PubMed

Islam, M Rofiqul; Haniu, H; Fardoushi, J

2009-02-01

Pyrolysis kinetics of available bicycle/rickshaw, motorcycle and truck tire wastes in Bangladesh have been investigated thermogravimetrically in a nitrogen atmosphere at heating rates of 10 and 60 degrees C/min over a temperature range of 30-800 degrees C. The three tire wastes exhibited similar behaviors in that, when heating rate was increased, the initial reaction temperature decreased but the reaction range and reaction rate increased. The percentage of total weight loss was higher for truck tire waste and lower for bicycle/rickshaw tire waste. The pyrolysis of truck tire waste was found to be easier than that of bicycle/rickshaw and motorcycle tire wastes while it was comparatively more difficult for motorcycle tire waste. The overall rate equation for the three tire wastes has been modeled satisfactorily by one simplified equation from which the kinetic parameters of unreacted materials based on the Arrhenius form can be determined. The predicted rate equation compares fairly well with the measured TG and DTG data. DTA curves for all of the samples show that the degradation reactions are three main exotherms and one endotherm.

78 FR 47050 - Cooper Tire & Rubber Company, Grant of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-02

...: Cooper Tire & Rubber Company (Cooper) \\1\\ has determined that certain Cooper brand replacement tires... approximately 1,080 size P225/ 70R14 El Dorado Legend GT brand standard load replacement tires manufactured in...

Runflat Testing

DTIC Science & Technology

2015-09-09

guidance and procedures for testing the performance characteristics of runflat tires as equipped on ground vehicles. 15. SUBJECT TERMS runflat... tire assembly tread life combat flat central tire inflation system (CTIS) 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...3 3.4 Tire Assemblies ..................................................................... 3 3.5 Environmental

Tire pressure special study : vehicle observation data

DOT National Transportation Integrated Search

2001-08-01

Twenty seven percent of passenger cars with : regular passenger car tires have at least one : tire that is underinflated by 8 psi or more. : Tire Pressure Special Study: Vehicle : Observation Data is the third in a series of : research notes co...

Evaluation of an Empirical Traction Equation for Forestry Tires

Treesearch

C.R. Vechinski; C.E. Johnson; R.L. Raper

1998-01-01

Variable load test data were used to evaluate the applicability of an existing forestry tire traction model for a new forestry tire and a worn tire of the same size with and without tire chains in a range of soil conditions. `The clay and sandy soi!s ranged in moisture content from 17 to 28%. Soil bulk density varied between 1.1 and 1.4g cm-3...

Analytical studies of the Space Shuttle orbiter nose-gear tire

NASA Technical Reports Server (NTRS)

Noor, Ahmed K.; Tanner, John A.; Peters, Jeanne M.; Robinson, Martha P.

1991-01-01

A computational procedure is presented for evaluating the analytic sensitivity derivatives of the tire response with respect to material and geometrical properties of the tire. The tire is modeled by using a two-dimensional laminated anisotropic shell theory with the effects of variation in material and geometric parameters included. The computational procedure is applied to the case of the Space Shuttle orbiter nose-gear tire subjected to uniform inflation pressure. Numerical results are presented which show the sensitivity of the different tire response quantities to variations in the material characteristics of both the cord and rubber.

Forensic analysis of tire rubbers based on their sulfur chemical states.

PubMed

Funatsuki, Atsushi; Shiota, Kenji; Takaoka, Masaki; Tamenori, Yusuke

2015-05-01

The chemical states of sulfur in 11 tires were analyzed using X-ray absorption near-edge structure (XANES) in order to discriminate between various tire rubbers. All tires had peaks around 2471.5 and 2480.5eV, and the shapes and heights of these peaks differed among tires, suggesting that the sulfur chemical state could be used for discrimination between tire rubbers. Based on t-tests on the results of XANES, 43 of 55 combinations were different at a significance level of 5%. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Retractable barrier strip

DOEpatents

Marts, Donna J.; Barker, Stacey G.; Wowczuk, Andrew; Vellenoweth, Thomas E.

2002-01-01

A portable barrier strip having retractable tire-puncture spikes for puncturing a vehicle tire. The tire-puncture spikes have an armed position for puncturing a tire and a retracted position for not puncturing a tire. The strip comprises a plurality of barrier blocks having the tire-puncture spikes removably disposed in a shaft that is rotatably disposed in each barrier block. The plurality of barrier blocks hare hingedly interconnected by complementary hinges integrally formed into the side of each barrier block which allow the strip to be rolled for easy storage and retrieval, but which prevent irregular or back bending of the strip. The shafts of adjacent barrier blocks are pivotally interconnected via a double hinged universal joint to accommodate irregularities in a roadway surface and to transmit torsional motion of the shaft from block to block. A single flexshaft cable is connected to the shaft of an end block to allow a user to selectively cause the shafts of a plurality of adjacently connected barrier blocks to rotate the tire-puncture spikes to the armed position for puncturing a vehicle tire, and to the retracted position for not puncturing the tire. The flexshaft is provided with a resiliently biased retracting mechanism, and a release latch for allowing the spikes to be quickly retracted after the intended vehicle tire is punctured.

Efficacy of alpha-cypermethrin and lambda-cyhalothrin applications to prevent Aedes breeding in tires.

PubMed

Pettit, William J; Whelan, Peter I; McDonnell, Joseph; Jacups, Susan P

2010-12-01

The efficacy of alpha-cypermethrin (Cyperthor) and lambda-cyhalothrin (Demand) to prevent mosquito larval colonization of water-containing receptacles was investigated using 2 differing applications in disused car tires in Darwin, Australia. Insecticide treatments were applied uniformly to the inside surfaces of 2 categories of tires: 1) dry tires that were partially filled with water 24 h after spraying and 2) wet tires partially filled with water prior to spraying. All mosquito larvae, pupae, and dead adults were collected from the treatment and control tires weekly over the 24-wk study period and were later identified to species in the laboratory. Control tires were colonized by Aedes notoscriptus in wk 2 and by Culex quinquefasciatus in wk 4. Aedes notoscriptus failed to colonize any alpha-cypermethrin-treated tires until wk 22 and did not colonize any lambda-cyhalothrin-treated tires during the 24-wk trial. Culex quinquefasciatus colonized alpha-cypermethrin and lambda-cyhalothrin-treated tires from wk 11 and wk 15, respectively. These results indicate both insecticides using either application method can prevent colonization of Ae. notoscriptus for at least 20 wk and demonstrate great potential for the prevention of breeding in receptacles for other receptacle-breeding Aedes species, such as the dengue vectors, Ae. aegypti and Ae. albopictus.

Al+Si Interface Optical Properties Obtained in the Si Solar Cell Configuration

DOE PAGES

Subedi, Indra; Silverman, Timothy J.; Deceglie, Michael G.; ...

2017-10-18

Al is a commonly used material for rear side metallization in commercial silicon (Si) wafer solar cells. In this study, through-the-silicon spectroscopic ellipsometry is used in a test sample to measure Al+Si interface optical properties like those in Si wafer solar cells. Two different spectroscopic ellipsometers are used for measurement of Al+Si interface optical properties over the 1128-2500 nm wavelength range. For validation, the measured interface optical properties are used in a ray tracing simulation over the 300-2500 nm wavelength range for an encapsulated Si solar cell having random pyramidal texture. The ray tracing model matches well with the measuredmore » total reflectance at normal incidence of a commercially available Si module. The Al+Si optical properties presented here enable quantitative assessment of major irradiance/current flux losses arising from reflection and parasitic absorption in encapsulated Si solar cells.« less

Al+Si Interface Optical Properties Obtained in the Si Solar Cell Configuration

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

Subedi, Indra; Silverman, Timothy J.; Deceglie, Michael G.

Al is a commonly used material for rear side metallization in commercial silicon (Si) wafer solar cells. In this study, through-the-silicon spectroscopic ellipsometry is used in a test sample to measure Al+Si interface optical properties like those in Si wafer solar cells. Two different spectroscopic ellipsometers are used for measurement of Al+Si interface optical properties over the 1128-2500 nm wavelength range. For validation, the measured interface optical properties are used in a ray tracing simulation over the 300-2500 nm wavelength range for an encapsulated Si solar cell having random pyramidal texture. The ray tracing model matches well with the measuredmore » total reflectance at normal incidence of a commercially available Si module. The Al+Si optical properties presented here enable quantitative assessment of major irradiance/current flux losses arising from reflection and parasitic absorption in encapsulated Si solar cells.« less

Directions for material recovery of used tires and their use in the production of new products intended for the industry of civil construction and pavements

NASA Astrophysics Data System (ADS)

Bulei, C.; Todor, M. P.; Heput, T.; Kiss, I.

2018-01-01

The management of waste from used tires is one of the major principles of recycling and reuse, which involves encouraging a high level of material recovery components, preferably by recycling. Given the current pressure on natural resources on a global scale we must fully take into account the waste in a broader framework defined by the flow of raw materials and their sustainable use. Thus, the opportunity to use various waste from used tires as raw material in order to support economic activities becomes a priority. The recycling of raw materials from waste products and their use in new production processes for their material capitalization is becoming a sustainable approach. Used tire recycling, is the process of recycling waste tires that are no longer suitable for use on vehicles due to wear or irreparable damage. These tires are a problematic source of waste, due to the large volume produced, the durability of the tires, and the components in the tire that are ecologically problematic. Although tires are usually burnt, not recycled, efforts are continuing to find value. Tires can be recycled into, among other things, typically as crumb rubber modifier in recycled pavement. The paper presents aspects of the product resulting from crushing of used tires (powder), which can be used properly valued in the street furniture field or building materials containing rubber.

Detection of tire tread particles using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Prochazka, David; Bilík, Martin; Prochazková, Petra; Klus, Jakub; Pořízka, Pavel; Novotný, Jan; Novotný, Karel; Ticová, Barbora; Bradáč, Albert; Semela, Marek; Kaiser, Jozef

2015-06-01

The objective of this paper is a study of the potential of laser induced breakdown spectroscopy (LIBS) for detection of tire tread particles. Tire tread particles may represent pollutants; simultaneously, it is potentially possible to exploit detection of tire tread particles for identification of optically imperceptible braking tracks at locations of road accidents. The paper describes the general composition of tire treads and selection of an element suitable for detection using the LIBS method. Subsequently, the applicable spectral line is selected considering interferences with lines of elements that might be present together with the detected particles, and optimization of measurement parameters such as incident laser energy, gate delay and gate width is performed. In order to eliminate the matrix effect, measurements were performed using 4 types of tires manufactured by 3 different producers. An adhesive tape was used as a sample carrier. The most suitable adhesive tape was selected from 5 commonly available tapes, on the basis of their respective LIBS spectra. Calibration standards, i.e. an adhesive tape with different area content of tire tread particles, were prepared for the selected tire. A calibration line was created on the basis of the aforementioned calibration standards. The linear section of this line was used for determination of the detection limit value applicable to the selected tire. Considering the insignificant influence of matrix of various types of tires, it is possible to make a simple recalculation of the detection limit value on the basis of zinc content in a specific tire.

77 FR 52203 - Airworthiness Directives; Goodyear Aviation Tires

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-29

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2012... Airworthiness Directives; Goodyear Aviation Tires AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... Goodyear Aviation Tires, part number 299K63-1 (Brazilian made new tires only), installed on various...

Investigation of best options for using scrap tires in highway noise barriers.

DOT National Transportation Integrated Search

2011-06-01

In Colorado, approximately 60 million scrap tires have been stockpiled and approximately 4.5 million scrap tires are : generated annually. While CDOT does not generate these scrap tires, CDOT does have goals and policies to promote : sustainability/r...

Rolling Resistance of Tires Measured Under Transient and Equilibrium Conditions on Calspan's Tire Research

DOT National Transportation Integrated Search

1976-03-01

Rolling loss tests were performed on 31 different passenger and 4 light truck tires under transient and equilibrium conditions. The tests were designed to determine the effects of load, speed, inflation pressure, tire temperature, slip angle, torque,...

Ground tire rubber as a stabilizer for subgrade soils.

DOT National Transportation Integrated Search

2014-05-01

Over 250 million scrap tires are generated annually in the U.S. Historically, a significant portion of these tires : have been processed into finely ground tire rubber (GTR), or crumb rubber, for use as an additive in hot mix asphalt : (HMA) pavement...

Tire with Self-Repairing Mechanism

NASA Astrophysics Data System (ADS)

Nagaya, Kosuke; Ikai, Sigeo; Chiba, Manabu; Chao, Xujing

A new type of tire is presented, in which there is no air leakage when nails puncture the tire. The broken part is repaired automatically by a self-repairing mechanism. The self-repairing unit consists of two rubber sheets with internal lattices. Polymer particles, which expand their volume on adding water, are inserted into the lattices. The unit is adhered to the inside wall of the tire. Coolant fluid diluted with water is introduced to the polymers uniformly. In this system, the polymer particles expand with water-diluted coolant fluid, and become gel. Hence, they stop air leakages in the tire. Fundamental experiments are performed, and optimum conditions are found. This technique is also applied to real tires, and it is ascertained that there is no air leakage when the tire is punctured by nails.

A study of the dynamic tire properties over a range of tire constructions

NASA Technical Reports Server (NTRS)

Nybakken, G. H.; Dodge, R. N.; Clark, S. K.

1973-01-01

The dynamic properties of four model aircraft tires of various construction were evaluated experimentally and compared with available theory. The experimental investigation consisted of measuring the cornering force and the self-aligning torque developed by the tires undergoing sinusoidal steering inputs while operating on a small scale, road-wheel tire testing apparatus. The force and moment data from the different tires are compared with both finite- and point-contact patch string theory predictions. In general, agreement between finite contact patch theory and experimental observation is good. A modified string theory is also presented in which coefficients for cornering force and self-aligning torque are determined separately. This theory improves the correspondence between the experimental and analytical data, particularly on tires with relatively high self-aligning torques.

ARC-1976-AC76-0965

NASA Image and Video Library

1976-06-11

Artist: Rick Guidice Space Colonization - Bernal Sphere - The residential area is in the central sphere. Farming regions are in the 'tires.' Mirrors reflect sunlight into the habitat and farms. The large flat panels radiate away extra heat into space, and panels of solar cells provide electricity. Factories and docks for spaceships are at either end of the long central tube. (NOTE: art printed in Book 'Space Colony - Frontier of the 21st Century by Franklyn M. Branley)

49 CFR 569.7 - Requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 6 2012-10-01 2012-10-01 false Requirements. 569.7 Section 569.7 Transportation..., DEPARTMENT OF TRANSPORTATION REGROOVED TIRES § 569.7 Requirements. (a) Regrooved tires. (1) Except as... requirements: (i) The tire being regrooved shall be a regroovable tire; (ii) After regrooving, cord material...

49 CFR 569.7 - Requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 6 2014-10-01 2014-10-01 false Requirements. 569.7 Section 569.7 Transportation..., DEPARTMENT OF TRANSPORTATION REGROOVED TIRES § 569.7 Requirements. (a) Regrooved tires. (1) Except as... requirements: (i) The tire being regrooved shall be a regroovable tire; (ii) After regrooving, cord material...

49 CFR 569.7 - Requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 6 2011-10-01 2011-10-01 false Requirements. 569.7 Section 569.7 Transportation..., DEPARTMENT OF TRANSPORTATION REGROOVED TIRES § 569.7 Requirements. (a) Regrooved tires. (1) Except as... requirements: (i) The tire being regrooved shall be a regroovable tire; (ii) After regrooving, cord material...

Ground tire rubber as a stabilizer for subgrade soils : [summary].

DOT National Transportation Integrated Search

2014-05-01

Over 250 million scrap tires are generated : annually in the U.S. Historically, a significant : portion of these tires have been processed into : finely ground tire rubber (GTR), or crumb rubber, : for use as an additive in hot mix asphalt (HMA) : pa...

Rolling resistance of electric vehicle tires from track tests

NASA Technical Reports Server (NTRS)

Dustin, M. O.; Slavik, R. J.

1982-01-01

Special low-rolling-resistance tires were made for DOE's ETV-1 electric vehicle. Tests were conducted on these tires and on a set of standard commercial automotive tires to determine the rolling resistance as a function of time during both constant-speed tires and SAE J227a driving cycle tests. The tests were conducted on a test track at ambient temperatures that ranged from 15 to 32 C (59 to 89 F) and with tire pressures of 207 to 276 kPa (30 to 40 psi). At a contained-air temperature of 38 C (100 F) and a pressure of 207 kPa (30 psi) the rolling resistances of the electric vehicle tires and the standard commercial tires, respectively, were 0.0102 and 0.0088 kilogram per kilogram of vehicle weight. At a contained-air temperature of 38 C (100 F) and a pressure of 276 kPa (40 psi) the rolling resistances were 0.009 and 0.0074 kilogram per kilogram of vehicle weight, respectively.

Compressive Strength and Modulus of Elasticity of Concrete with Cubed Waste Tire Rubbers as Coarse Aggregates

NASA Astrophysics Data System (ADS)

Haryanto, Y.; Hermanto, N. I. S.; Pamudji, G.; Wardana, K. P.

2017-11-01

One feasible solution to overcome the issue of tire disposal waste is the use of waste tire rubber to replace aggregate in concrete. We have conducted an experimental investigation on the effect of rubber tire waste aggregate in cuboid form on the compressive strength and modulus of elasticity of concrete. The test was performed on 72 cylindrical specimens with the height of 300 mm and diameter of 150 mm. We found that the workability of concrete with waste tire rubber aggregate has increased. The concrete density with waste tire rubber aggregate was decreased, and so was the compressive strength. The decrease of compressive strength is up to 64.34%. If the content of waste tire rubber aggregate is more than 40%, then the resulting concrete cannot be categorized as structural concrete. The modulus of elasticity decreased to 59.77%. The theoretical equation developed to determine the modulus of elasticity of concrete with rubber tire waste aggregate has an accuracy of 84.27%.

Identification of tire leachate toxicants and a risk assessment of water quality effects using tire reefs in canals

USGS Publications Warehouse

Nelson, S. M.; Mueller, G.; Hemphill, D. C.

1994-01-01

Cover is an important component of aquatic habitat and fisheries management. Fisheries biologists often try to improve habitats through the addition of natural and artificial material to improve cover diversity and complexity. Habitat-improvement programs range from submerging used Christmas trees to more complex programs using sophisticated artificial habitat modules. Used automobile tires have been employed in the large scale construction of reefs and fish attractors in marine environments (D'Itri 1985) and to a lesser extent in freshwater (Johnson and Stein 1979) and have been recognized as a durable, inexpensive and long-lasting material which benefits fishery communities. Recent studies by the U.S. Bureau of Reclamation (Mueller and Liston 1991) have quantified the importance of tire reeds to enhancing freshwater canal fisheries in the southwestern United States. These studies have demonstrated that fisheries and aquatic macroinvertebrates are attracted to these structures, increasing species diversity, densities and biomass where reefs are places in canals. Potential benefits to fishermen are great in the form of recreational fishing. However, the use of tire reefs in aquatic environments which have relatively small volumes compared to marine or reservoir environments has raised water quality concerns. Effects of tires on water quality have not typically been studied in the part because of the obvious presence of fishes and other aquatic organisms that make use of tire reefs; the implication being that tires are intert and non-toxic. Little information on effects of tires on water quality is contained in the literature. Stone et al. (1975) demonstrated that tire exposure had no detrimental effects on two species of marine fish while results of Kellough's (1991) freshwater tests were inconclusive, but suggested that some factor in tire leachate was toxic to rainbow trout (Oncorhynchus mykiss). Nozaka et al. (1973) found no harmful substances leached from tire material soaked in fresh water. Because there are few data on toxicity associated with tires, this became the focus of our study. Toxicity Identification Evaluation (TUE) procedures developed by the EPA (1991) were used to evaluate water quality impacted by tires.

Economic and policy instrument analyses in support of the scrap tire recycling program in Taiwan.

PubMed

Chang, Ni-Bin

2008-02-01

Understanding the cost-effectiveness and the role of economic and policy instruments, such as the combined product tax-recycling subsidy scheme or a tradable permit, for scrap tire recycling has been of crucial importance in a market-oriented environmental management system. Promoting product (tire) stewardship on one hand and improving incentive-based recycling policy on the other hand requires a comprehensive analysis of the interfaces and interactions in the nexus of economic impacts, environmental management, environmental valuation, and cost-benefit analysis. This paper presents an assessment of the interfaces and interactions between the implementation of policy instruments and its associated economic evaluation for sustaining a scrap tire recycling program in Taiwan during the era of the strong economic growth of the late 1990s. It begins with an introduction of the management of the co-evolution between technology metrics of scrap tire recycling and organizational changes for meeting the managerial goals island-wide during the 1990s. The database collected and used for such analysis covers 17 major tire recycling firms and 10 major tire manufacturers at that time. With estimates of scrap tire generation and possible scale of subsidy with respect to differing tire recycling technologies applied, economic analysis eventually leads to identify the associated levels of product tax with respect to various sizes of new tires. It particularly demonstrates a broad perspective of how an integrated econometric and engineering economic analysis can be conducted to assist in implementing policy instruments for scrap tire management. Research findings indicate that different subsidy settings for collection, processing, and end use of scrap tires should be configured to ameliorate the overall managerial effectiveness. Removing the existing boundaries between designated service districts could strengthen the competitiveness of scrap tires recycling industry, helping to reduce the required levels of product tax and subsidy. With such initial breakthroughs at hand to handle the complexity of scrap tire recycling technologies, there remains unique management and policy avenues left to explore if a multi-dimensional solution is to be successful in the long run.

Formation of pentacene wetting layer on the SiO2 surface and charge trap in the wetting layer.

PubMed

Kim, Chaeho; Jeon, D

2008-09-01

We studied the early-stage growth of vacuum-evaporated pentacene film on a native SiO(2) surface using atomic force microscopy and in-situ spectroscopic ellipsometry. Pentacene deposition prompted an immediate change in the ellipsometry spectra, but atomic force microscopy images of the early stage films did not show a pentacene-related morphology other than the decrease in the surface roughness. This suggested that a thin pentacene wetting layer was formed by pentacene molecules lying on the surface before the crystalline islands nucleated. Growth simulation based on the in situ spectroscopic ellipsometry spectra supported this conclusion. Scanning capacitance microscopy measurement indicated the existence of trapped charges in the SiO(2) and pentacene wetting layer.

Passive wireless strain monitoring of tire using capacitance change

NASA Astrophysics Data System (ADS)

Matsuzaki, Ryosuke; Todoroki, Akira

2004-07-01

In-service strain monitoring of tires of automobile is quite effective for improving the reliability of tires and Anti-lock Braking System (ABS). Since conventional strain gages have high stiffness and require lead wires, the conventional strain gages are cumbersome for the strain measurements of the tires. In a previous study, the authors proposed a new wireless strain monitoring method that adopts the tire itself as a sensor, with an oscillating circuit. This method is very simple and useful, but it requires a battery to activate the oscillating circuit. In the present study, the previous method for wireless tire monitoring is improved to produce a passive wireless sensor. A specimen made from a commercially available tire is connected to a tuning circuit comprising an inductance and a capacitance as a condenser. The capacitance change of tire causes change of the tuning frequency. This change of the tuned radio wave enables us to measure the applied strain of the specimen wirelessly, without any power supply from outside. This new passive wireless method is applied to a specimen and the static applied strain is measured. As a result, the method is experimentally shown to be effective as a passive wireless strain monitoring of tires.

CV-990 Landing Systems Research Aircraft (LSRA) flight #145 drilling of shuttle tire using Tire Assault Vehicle

NASA Image and Video Library

1995-07-27

Created from a 1/16th model of a German World War II tank, the TAV (Tire Assault Vehicle) was an important safety feature for the Convair 990 Landing System Research Aircraft, which tested space shuttle tires. It was imperative to know the extreme conditions the shuttle tires could tolerate at landing without putting the shuttle and its crew at risk. In addition, the CV990 was able to land repeatedly to test the tires. The TAV was built from a kit and modified into a radio controlled, video-equipped machine to drill holes in aircraft test tires that were in imminent danger of exploding because of one or more conditions: high air pressure, high temperatures, and cord wear. An exploding test tire releases energy equivalent to two and one-half sticks of dynamite and can cause severe injuries to anyone within 50 ft. of the explosion, as well as ear injury - possibly permanent hearing loss - to anyone within 100 ft. The degree of danger is also determined by the temperature pressure and cord wear of a test tire. The TAV was developed by David Carrott, a PRC employee under contract to NASA.

FE-DEM Analysis of the Effect of Tread Pattern on the Tractive Performance of Tires Operating on Sand

NASA Astrophysics Data System (ADS)

Nakashima, Hiroshi; Takatsu, Yuzuru; Shinone, Hisanori; Matsukawa, Hisao; Kasetani, Takahiro

Soil-tire system interaction is a fundamental and important research topic in terramechanics. We applied a 2D finite element, discrete element method (FE-DEM), using FEM for the tire and the bottom soil layer and DEM for the surface soil layer. Satisfactory performance analysis was achieved. In this study, to clarify the capabilities and limitations of the method for soil-tire interaction analysis, the tractive performance of real automobile tires with two different tread patterns—smooth and grooved—was analyzed by FE-DEM, and the numerical results compared with the experimental results obtained using an indoor traction measurement system. The analysis of tractive performance could be performed with sufficient accuracy by the proposed 2D dynamic FE-DEM. FE-DEM obtained larger drawbar pull for a tire with a grooved tread pattern, which was verified by the experimental results. Moreover, the result for the grooved tire showed almost the same gross tractive effort and similar running resistance as in experiments. However, for a tire with smooth tread pattern, the analyzed gross tractive effort and running resistance behaved differently than the experimental results, largely due to the difference in tire sinkage in FE-DEM.

The effect of chine tires on nose gear water-spray characteristics of a twin engine airplane

NASA Technical Reports Server (NTRS)

Yager, T. J.; Stubbs, S. M.; Mccarty, J. L.

1975-01-01

An experimental investigation was performed to evaluate the effectiveness of nose gear chine tires in eliminating or minimizing the engine spray ingestion problem encountered on several occasions by the Merlin 4, a twin-engine propjet airplane. A study of the photographic and television coverage indicated that under similar test conditions the spray from the chine tires presented less of a potential engine spray ingestion problem than the conventional tires. Neither tire configuration appeared to pose any ingestion problem at aircraft speeds in excess of the hydroplaning speed for each tire, however, significant differences were noted in the spray patterns of the two sets of tires at sub-hydroplaning speeds. At sub-hydroplaning speeds, the conventional tires produced substantial spray above the wing which approached the general area of the engine air inlet at lower test speeds. The chine tires produced two distinct spray plumes at sub-hydroplaning speeds: one low-level plume which presented no apparent threat of ingestion, and one which at most test speeds was observed to be below the wing leading edge and thus displaced from the intakes on the engine nacelle.

CV-990 Landing Systems Research Aircraft (LSRA) flight #145 drilling of shuttle tire using Tire Assa

NASA Technical Reports Server (NTRS)

1995-01-01

Created from a 1/16th model of a German World War II tank, the TAV (Tire Assault Vehicle) was an important safety feature for the Convair 990 Landing System Research Aircraft, which tested space shuttle tires. It was imperative to know the extreme conditions the shuttle tires could tolerate at landing without putting the shuttle and its crew at risk. In addition, the CV990 was able to land repeatedly to test the tires. The TAV was built from a kit and modified into a radio controlled, video-equipped machine to drill holes in aircraft test tires that were in imminent danger of exploding because of one or more conditions: high air pressure, high temperatures, and cord wear. An exploding test tire releases energy equivalent to two and one-half sticks of dynamite and can cause severe injuries to anyone within 50 ft. of the explosion, as well as ear injury - possibly permanent hearing loss - to anyone within 100 ft. The degree of danger is also determined by the temperature pressure and cord wear of a test tire. The TAV was developed by David Carrott, a PRC employee under contract to NASA.

14 CFR 27.733 - Tires.

Code of Federal Regulations, 2011 CFR

2011-01-01

... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.733 Tires. (a) Each landing... gravity. (c) Each tire installed on a retractable landing gear system must, at the maximum size of the tire type expected in service, have a clearance to surrounding structure and systems that is adequate...

76 FR 28502 - Cooper Tire & Rubber Tire Company, Receipt of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-17

... one-fourth of the distance from the bead to the shoulder of the tire. If the maximum section width... from the bead to the shoulder of the tire, on at least one sidewall. The markings must be in letters...

Fore and aft elastic response characteristics of size 34x9.9, type 7, 14 ply-rated aircraft tires of bias ply, bias belted, and radial belted design. M.S. Thesis - George Washington Univ., Washington, D. C.

NASA Technical Reports Server (NTRS)

Tanner, J. A.

1973-01-01

An investigation was conducted to determine the fore-and-aft elastic response characteristics of aircraft tires of bias ply, bias-belted, and radial-belted design. The investigation consisted of: (1)static and rolling tests, (2)a statistical analysis which related the measured tire elastic characteristics to variations in the vertical load, inflation pressure, braking force and/or tire vertical deflection, and (3) a semi-empirical analysis which related the tire elastic behavior to measured wheel slippage during a steady-state braking. The results of this investigation indicate that the bias-belted tire has the largest spring constant value for most loading conditions and the radial-belted tire has the smallest spring constant value.

Laser cleaning of the contaminations on the surface of tire mould

NASA Astrophysics Data System (ADS)

Ye, Yayun; Jia, Baoshen; Chen, Jing; Jiang, Yilan; Tang, Hongping; Wang, Haijun; Luan, Xiaoyu; Liao, Wei; Zhang, Chuanchao; Yao, Caizhen

2017-07-01

During the manufacturing of tires, surface pollutants on tire mould will lead to the production of unqualified tires. Tire moulds need to be regularly cleaned. Laser cleaning is recognized as a non-destructive, effective, precise and environmental friendly method. In this paper, laser cleaning was used to remove contaminants on tire mould surface. First, laser induced damage experiments were performed. The results showed that the roughness and hardness of the cast steel sample surface seldom changed under the energy range of 140.1-580.2 mJ laser irradiation 1 pulse and the energy range of 44.7-168.9 mJ laser irradiation 100 pulses. In the laser cleaning experiments, the cleaning thresholds and the optimal cleaning parameters were obtained. Results indicated that laser cleaning was safe and effective for tire mould contamination removal.

Impacts of weathered tire debris on the development of Rana sylvatica larvae

USGS Publications Warehouse

Camponelli, K.M.; Casey, R.E.; Snodgrass, J.W.; Lev, S.M.; Landa, E.R.

2009-01-01

Highway runoff has the potential to negatively impact receiving systems including stormwater retention ponds where highway particulate matter can accumulate following runoff events. Tire wear particles, which contain about 1% Zn by mass, make up approximately one-third of the vehicle derived particulates in highway runoff and therefore may serve as a stressor to organisms utilizing retention ponds as habitat. In this study, we focused on the potential contribution of tire debris to Zn accumulation by Rana sylvatica larvae and possible lethal or sublethal impacts resulting from exposure to weathered tire debris during development. Eggs and larvae were exposed to aged sediments (containing either ZnCl2 or tire particulate matter, both providing nominal concentrations of 1000 mg Zn kg-1) through metamorphosis. Water column Zn was elevated in both the ZnCl2 and tire treatments relative to the control treatment, indicating that aging allowed Zn leaching from tire debris to occur. Tissue Zn was also elevated for the ZnCl2 and tire treatments indicating that Zn in the treatments was available for uptake by the amphibians. Exposure to both ZnCl2 and tire treatments increased the time for larvae to complete metamorphosis in comparison with controls. We also observed that the longer the organisms took to complete metamorphosis, the smaller their mass at metamorphosis. Our results indicate that Zn leached from aged tire debris is bioavailable to developing R. sylvatica larvae and that exposure to tire debris amended sediments can result in measurable physiological outcomes to wood frogs that may influence population dynamics. ?? 2008 Elsevier Ltd.

Impacts of weathered tire debris on the development of Rana sylvatica larvae.

PubMed

Camponelli, Kimberly M; Casey, Ryan E; Snodgrass, Joel W; Lev, Steven M; Landa, Edward R

2009-02-01

Highway runoff has the potential to negatively impact receiving systems including stormwater retention ponds where highway particulate matter can accumulate following runoff events. Tire wear particles, which contain about 1% Zn by mass, make up approximately one-third of the vehicle derived particulates in highway runoff and therefore may serve as a stressor to organisms utilizing retention ponds as habitat. In this study, we focused on the potential contribution of tire debris to Zn accumulation by Rana sylvatica larvae and possible lethal or sublethal impacts resulting from exposure to weathered tire debris during development. Eggs and larvae were exposed to aged sediments (containing either ZnCl2 or tire particulate matter, both providing nominal concentrations of 1000 mg Zn kg(-1)) through metamorphosis. Water column Zn was elevated in both the ZnCl2 and tire treatments relative to the control treatment, indicating that aging allowed Zn leaching from tire debris to occur. Tissue Zn was also elevated for the ZnCl2 and tire treatments indicating that Zn in the treatments was available for uptake by the amphibians. Exposure to both ZnCl2 and tire treatments increased the time for larvae to complete metamorphosis in comparison with controls. We also observed that the longer the organisms took to complete metamorphosis, the smaller their mass at metamorphosis. Our results indicate that Zn leached from aged tire debris is bioavailable to developing R. sylvatica larvae and that exposure to tire debris amended sediments can result in measurable physiological outcomes to wood frogs that may influence population dynamics.

78 FR 9775 - Cooper Tire & Rubber Company, Receipt of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-11

...: Cooper Tire & Rubber Company (Cooper),\\1\\ has determined that certain Cooper brand tires manufactured... brand standard load tires manufactured in Mexico by Cooper's affiliate, Corporaci[oacute]n de Occidente... Docket Management System (FDMS) Web site at http://www.regulations.gov/ . Follow the online instructions...

Results of Energy-Loss Measurements on Passenger Car Tires Operating in the Free-Rolling and Braking/Traction Modes

DOT National Transportation Integrated Search

1980-01-01

This report described the results of tests on twelve passenger car tires performed on Calspan's Tire Research Facility (CTRF). The tests were used to measure energy loss under three different test conditions: 1) with the tire in a straight, free-roll...

40 CFR 63.5984 - What emission limits must I meet for tire production affected sources?

Code of Federal Regulations, 2010 CFR

2010-07-01

... tire production affected sources? 63.5984 Section 63.5984 Protection of Environment ENVIRONMENTAL... POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Production Affected Sources § 63.5984 What emission limits must I meet...

16 CFR 1512.10 - Requirements for tires.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Requirements for tires. 1512.10 Section 1512... REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.10 Requirements for tires. The manufacturer's recommended inflation pressure shall be molded into or onto the sidewall of the tire in lettering no less than...

49 CFR 574.9 - Requirements for motor vehicle dealers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) TIRE IDENTIFICATION AND... equipped with new tires is considered, for purposes of this part, to be a tire dealer and shall meet the... other than resale, that is equipped with new tires that were not on the motor vehicle when shipped by...

Characterizing Tire Crumb Rubber for Exposure Assessment

EPA Science Inventory

Tire crumb rubber derived from recycled tires is widely used as infill material in synthetic turf fields in the United States. An estimated 95% of the over 12,000 installed fields in the U.S. use tire crumb rubber infill alone or mixed with sand or alternative materials. Concerns...

14 CFR 25.733 - Tires.

Code of Federal Regulations, 2011 CFR

2011-01-01

... reactions in paragraph (b) of this section, on the nose wheel tire, except as provided in paragraphs (b)(2) and (b)(3) of this section. (b) The applicable ground reactions for nose wheel tires are as follows: (1) The static ground reaction for the tire corresponding to the most critical combination of...

14 CFR 25.733 - Tires.

Code of Federal Regulations, 2010 CFR

2010-01-01

... reactions in paragraph (b) of this section, on the nose wheel tire, except as provided in paragraphs (b)(2) and (b)(3) of this section. (b) The applicable ground reactions for nose wheel tires are as follows: (1) The static ground reaction for the tire corresponding to the most critical combination of...

Procedures for controlling the effect of increased tire pressure on asphalt concrete pavement damage.

DOT National Transportation Integrated Search

1988-06-01

As the axle load increases, higher tire pressures become more popular for long-haul truck operators. To collect data on tire pressures and the types of tires in use, a survey was carried out at a weigh station located on Interstate 5 in Oregon during...

Visualization of tire vibration and sound radiation and modeling of tire vibration with an emphasis on wave propagation

DOT National Transportation Integrated Search

2003-08-01

It is now known that tire/road interaction noise is the major contributor to exterior automobile noise and establishes the background noise level in many environments. Thus, the reduction of tire/road noise is a major environmental noise issue today....

78 FR 3843 - Federal Motor Vehicle Safety Standards; New Pneumatic and Certain Specialty Tires

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-17

... construction from conventional tires. * * * [with] a higher inflation pressure (60 psi), different dimensions... measure the tire's growth under inflated conditions and to determine if it is within allowable growth limits. If a tire exceeds allowable growth limits in the physical dimensions test, that indicates that...

Robot Drills Holes To Relieve Excess Tire Pressures

NASA Technical Reports Server (NTRS)

Carrott, David T.

1996-01-01

Small, relatively inexpensive, remotely controlled robot called "tire assault vehicle" (TAV) developed to relieve excess tire pressures to protect ground crew, aircraft equipment, and nearby vehicles engaged in landing tests of CV-990 Landing System Research Aircraft. Reduces costs and saves time in training, maintenance, and setup related to "yellow" and "red" tire conditions. Adapted to any heavy-aircraft environment in which ground-crew safety at risk because of potential for tire explosions. Also ideal as scout vehicle for performing inspections in hazardous locations.

Simulation of Thermal Signature of Tires and Tracks

DTIC Science & Technology

2012-08-01

the body-ply is a linear elastic material. To facilitate the analysis, the tire was divided into Tread and Sidewall by the dash line as shown in...only one element is assigned through the thickness of the tire . Therefore, the thickness of the element is the same as the thickness of the tire ...to the whole part of the 3D full tire in the thermal analysis. The average strain energy density for each part ( tread or sidewall) in the cross

A dual systems account of visual perception: Predicting candy consumption from distance estimates.

PubMed

Krpan, Dario; Schnall, Simone

2017-04-01

A substantial amount of evidence shows that visual perception is influenced by forces that control human actions, ranging from motivation to physiological potential. However, studies have not yet provided convincing evidence that perception itself is directly involved in everyday behaviors such as eating. We suggest that this issue can be resolved by employing the dual systems account of human behavior. We tested the link between perceived distance to candies and their consumption for participants who were tired or depleted (impulsive system), versus those who were not (reflective system). Perception predicted eating only when participants were tired (Experiment 1) or depleted (Experiments 2 and 3). In contrast, a rational determinant of behavior-eating restraint towards candies-predicted eating for non-depleted individuals (Experiment 2). Finally, Experiment 3 established that perceived distance was correlated with participants' self-reported motivation to consume candies. Overall, these findings suggest that the dynamics between perception and behavior depend on the interplay of the two behavioral systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Remote tire pressure sensing technique

NASA Technical Reports Server (NTRS)

Robinson, Howard H. (Inventor); Mcginnis, Timothy A. (Inventor); Daugherty, Robert H. (Inventor)

1993-01-01

A remote tire pressure sensing technique is provided which uses vibration frequency to determine tire pressure. A vibration frequency measuring device is attached to the external surface of a tire which is then struck with an object, causing the tire to vibrate. The frequency measuring device measures the vibrations and converts the vibrations into corresponding electrical impulses. The electrical impulses are then fed into the frequency analyzing system which uses the electrical impulses to determine the relative peaks of the vibration frequencies as detected by the frequency measuring device. The measured vibration frequency peaks are then compared to predetermined data describing the location of vibration frequency peaks for a given pressure, thereby determining the air pressure of the tire.

A systematic experimental investigation of significant parameters affecting model tire hydroplaning

NASA Technical Reports Server (NTRS)

Wray, G. A.; Ehrlich, I. R.

1973-01-01

The results of a comprehensive parametric study of model and small pneumatic tires operating on a wet surface are presented. Hydroplaning inception (spin down) and rolling restoration (spin up) are discussed. Conclusions indicate that hydroplaning inception occurs at a speed significantly higher than the rolling restoration speed. Hydroplaning speed increases considerably with tread depth, surface roughness and tire inflation pressure of footprint pressure, and only moderately with increased load. Water film thickness affects spin down speed only slightly. Spin down speed varies inversely as approximately the one-sixth power of film thickness. Empirical equations relating tire inflation pressure, normal load, tire diameter and water film thickness have been generated for various tire tread and surface configurations.

Study on profile measurement of extruding tire tread by laser

NASA Astrophysics Data System (ADS)

Wang, LiangCai; Zhang, Wanping; Zhu, Weihu

1996-10-01

This paper presents a new 2D measuring system-profile measurement of extruding tire tread by laser. It includes the thickness measurement of extruding tire tread by laser and the width measurement of extruding tire tread using Moire Fringe. The system has been applied to process line of extruding tire tread. Two measuring results have been obtained. One is a standard profile picture of extruding tire tread including seven measuring values. Another one is a series of thickness and width values. When the scanning speed < 100mm/sec and total width < 800mm. The measuring errors of width < +/- 0.5mm. While the thickness range is < 40mm. The measuring errors of thickness < +/- 0.1mm.

Heat generation in aircraft tires under braked rolling conditions

NASA Technical Reports Server (NTRS)

Clark, S. K.; Dodge, R. N.

1984-01-01

An analytical model was developed to approximate the internal temperature distribution in an aircraft tire operating under conditions of unyawed braked rolling. The model employs an array of elements to represent the tire cross section and considers the heat generated within the tire to be caused by the change in strain energy associated with cyclic tire deflection. The additional heating due to tire slip and stresses induced by braking are superimposed on the previously developed free rolling model. An extensive experimental program was conducted to verify temperatures predicted from the analytical model. Data from these tests were compared with calculations over a range of operating conditions. The model results were in reasonably good agreement with measured values.

Vehicle Dynamics Control of In-wheel Electric Motor Drive Vehicles Based on Averaging of Tire Force Usage

NASA Astrophysics Data System (ADS)

Masaki, Nobuo; Iwano, Haruo; Kamada, Takayoshi; Nagai, Masao

For in-wheel electric motor drive vehicles, a new vehicle dynamics control which is based on the tire force usage rate is proposed. The new controller adopts non-linear optimal control could manage the interference between direct yaw-moment control and the tire force usage rate. The new control is considered total longitudinal and transverse tire force. Therefore the controller can prevent tire force saturation near tire force limit during cornering. Simulations and test runs by the custom made four wheel drive in-wheel motor electric vehicle show that higher driving stability performance compared to the performance of the same vehicle without control.

Growth studies of CVD-MBE by in-situ diagnostics

NASA Astrophysics Data System (ADS)

Maracas, George N.; Steimle, Timothy C.

1992-10-01

This is the final technical report for the three year DARPA-URI program 'Growth Studies of CVD-MBE by in-situ Diagnostics'. The goals of the program were to develop non-invasive, real time epitaxial growth monitoring techniques and combine them to gain an understanding of processes that occur during MBE growth from gas sources. We have adapted these techniques to a commercially designed gas source MBE system (Vacuum Generators Inc.) to facilitate technology transfer out of the laboratory into industrial environments. The in-situ measurement techniques of spectroscopic ellipsometry (SE) and laser induced fluorescence (LIF) have been successfully implemented to monitor the optical and chemical properties of the growing epitaxial film and the gas phase reactants. The ellipsometer was jointly developed with the J. Woolam Co. and has become a commercial product. The temperature dependence of group 3 and 5 desorption from GaAs and InP has been measured as well as the incident effusion cell fluxes. The temporal evolution of the growth has also been measured both by SE and LIF to show the smoothing of heterojunction surfaces during growth interruption. Complicated microcavity optical device structures have been monitored by ellipsometry in real time to improve device quality. This data has been coupled with the structural information obtained from reflection high energy electron diffraction (RHEED) to understand the growth processes in binary and ternary bulk 3-5 semiconductors and heterojunctions.

Evaluation of the tire pressure influence on the lateral forces that occur between tire and road

NASA Astrophysics Data System (ADS)

Cordoş, N.; Todoruţ, A.; Barabás, I.

2017-10-01

The main objective of the paper is to capture the behavior of a vehicle on a race circuit, depending on the different inflation pressures of the tires (underpressure and overpressure). Taking into account that in the cornering the forces and the moments of inertia rise due the vehicle mass, and an inertial force decomposes in two components, one in the longitudinal plane and one in the transverse plane, the work aims the assessing the lateral forces that appear, to the contact between the tires and the tread, depending on the inflation pressure. The results have a graphic interpretation, enabling a comparative study of them. Results have been obtained regarding the lateral tire forces that occur between the tire and the road. The differences between these forces were particularly noticeable in cornering, and the differences between these forces were interpreted according to the tire inflation pressure.

Orbiter post-tire failure and skid testing results

NASA Technical Reports Server (NTRS)

Daugherty, Robert H.; Stubbs, Sandy M.

1989-01-01

An investigation was conducted at the NASA Langley Research Center's Aircraft Landing Dynamics Facility (ALDF) to define the post-tire failure drag characteristics of the Space Shuttle Orbiter main tire and wheel assembly. Skid tests on various materials were also conducted to define their friction and wear rate characteristics under higher speed and bearing pressures than any previous tests. The skid tests were conducted to support a feasibility study of adding a skid to the orbiter strut between the main tires to protect an intact tire from failure due to overload should one of the tires fail. Roll-on-rim tests were conducted to define the ability of a standard and a modified orbiter main wheel to roll without a tire. Results of the investigation are combined into a generic model of strut drag versus time under failure conditions for inclusion into rollout simulators used to train the shuttle astronauts.

On the dynamic response at the wheel axle of a pneumatic tire

NASA Astrophysics Data System (ADS)

Kung, L. E.; Soedel, W.; Yang, T. Y.

1986-06-01

A method for calculating the steady state displacement response and force transmission at the wheel axle of a pneumatic tire-suspension system due to a steady state force or displacement excitation at the tire to ground contact point is developed. The method requires the frequency responses (or receptances)_of both tire-wheel and suspension units. The frequency response of the tire-wheel unit is obtained by using the modal expansion method. The natural frequencies and mode shapes of the tire-wheel unit are obtained by using a geometrically non-linear, ring type, thin shell finite element of laminate composite. The frequency response of the suspension unit is obtained analytically. These frequency responses are used to calculate the force-input and the displacement-input responses at the wheel axle. This method allows the freedom of designing a vehicle and its tires independently and still achieving optimum dynamic performance.

Analysis of Tire Tractive Performance on Deformable Terrain by Finite Element-Discrete Element Method

NASA Astrophysics Data System (ADS)

Nakashima, Hiroshi; Takatsu, Yuzuru

The goal of this study is to develop a practical and fast simulation tool for soil-tire interaction analysis, where finite element method (FEM) and discrete element method (DEM) are coupled together, and which can be realized on a desktop PC. We have extended our formerly proposed dynamic FE-DE method (FE-DEM) to include practical soil-tire system interaction, where not only the vertical sinkage of a tire, but also the travel of a driven tire was considered. Numerical simulation by FE-DEM is stable, and the relationships between variables, such as load-sinkage and sinkage-travel distance, and the gross tractive effort and running resistance characteristics, are obtained. Moreover, the simulation result is accurate enough to predict the maximum drawbar pull for a given tire, once the appropriate parameter values are provided. Therefore, the developed FE-DEM program can be applied with sufficient accuracy to interaction problems in soil-tire systems.

Integrated Photonics Research Topical Meeting (1993)

DTIC Science & Technology

1994-06-01

81 DMD Time Domain Methods .................................. 107 IME Photonic Circuits and Lightwave Reception...index change near the band edge using a small interference -ellipsometry bridge and presented several results of nt of refractive index change An[51. In... interference -ellipsometry bridge at the photon energies near Eg, especially E>Eg, and compared to previous theories. [11. Manning, R Olshans]y, and C. B. Su

Computational Modeling of Tires

NASA Technical Reports Server (NTRS)

Noor, Ahmed K. (Compiler); Tanner, John A. (Compiler)

1995-01-01

This document contains presentations and discussions from the joint UVA/NASA Workshop on Computational Modeling of Tires. The workshop attendees represented NASA, the Army and Air force, tire companies, commercial software developers, and academia. The workshop objectives were to assess the state of technology in the computational modeling of tires and to provide guidelines for future research.

3 CFR - Imports of Certain Passenger Vehicle and Light Truck Tires From the People's Republic of China

Code of Federal Regulations, 2010 CFR

2010-01-01

... Tires From the People's Republic of China Presidential Documents Other Presidential Documents... Truck Tires From the People's Republic of China Memorandum for the Secretary of Commerce[,] the... vehicle and light truck tires from the People's Republic of China (China) are being imported into the...

40 CFR 63.5986 - What emission limits must I meet for tire cord production affected sources?

Code of Federal Regulations, 2010 CFR

2010-07-01

... tire cord production affected sources? 63.5986 Section 63.5986 Protection of Environment ENVIRONMENTAL... POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Cord Production Affected Sources § 63.5986 What emission limits must I...

75 FR 32536 - Foreign Tire Sales, Inc., Receipt of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-08

...-0063; Notice 1] Foreign Tire Sales, Inc., Receipt of Petition for Decision of Inconsequential Noncompliance Foreign Tire Sales, Inc. (FTS) \\1\\, as importer of record for ProMeter brand medium truck radial... Noncompliance Responsibility and Reports. \\1\\ Foreign Tire Sales, Inc. is an importer of replacement motor...

26 CFR 48.4071-1 - Imposition and rates of tax.

Code of Federal Regulations, 2011 CFR

2011-04-01

... manufacturer. (d) Recapped or retreaded tires. The recapping or retreading of a tire, whether from shoulder-to-shoulder or bead-to-bead, does not constitute manufacture of a taxable tire. The tax on tires imposed by... carcass not previously sold in the United States that is recapped or retreaded from shoulder-to-shoulder...

26 CFR 48.4071-1 - Imposition and rates of tax.

Code of Federal Regulations, 2013 CFR

2013-04-01

... manufacturer. (d) Recapped or retreaded tires. The recapping or retreading of a tire, whether from shoulder-to-shoulder or bead-to-bead, does not constitute manufacture of a taxable tire. The tax on tires imposed by... carcass not previously sold in the United States that is recapped or retreaded from shoulder-to-shoulder...

26 CFR 48.4071-1 - Imposition and rates of tax.

Code of Federal Regulations, 2010 CFR

2010-04-01

... manufacturer. (d) Recapped or retreaded tires. The recapping or retreading of a tire, whether from shoulder-to-shoulder or bead-to-bead, does not constitute manufacture of a taxable tire. The tax on tires imposed by... carcass not previously sold in the United States that is recapped or retreaded from shoulder-to-shoulder...

26 CFR 48.4071-1 - Imposition and rates of tax.

Code of Federal Regulations, 2012 CFR

2012-04-01

... manufacturer. (d) Recapped or retreaded tires. The recapping or retreading of a tire, whether from shoulder-to-shoulder or bead-to-bead, does not constitute manufacture of a taxable tire. The tax on tires imposed by... carcass not previously sold in the United States that is recapped or retreaded from shoulder-to-shoulder...

49 CFR 230.112 - Wheels and tires.

Code of Federal Regulations, 2010 CFR

2010-10-01

... wheels mounted on the same axle shall not vary more than 1/4 inch. (d) Tire thickness. Wheels may not have tires with a minimum thickness less than that indicated in the table in this paragraph (d). When... the minimum thickness of tires may be as much below the limits specified earlier in this paragraph (d...

75 FR 81712 - The Goodyear Tire & Rubber Company, Receipt of Petition for Decision of Inconsequential...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-28

..., all of the tires included in this petition meet or exceed the performance requirements of FMVSS No...-0174; Notice 1] The Goodyear Tire & Rubber Company, Receipt of Petition for Decision of Inconsequential Noncompliance The Goodyear Tire & Rubber Company (Goodyear) \\1\\ has determined that certain Goodyear commercial...

77 FR 2775 - Goodyear Tire and Rubber Company, Grant of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-19

... tread wear, temperature, and traction ratings, to assess performance capabilities of various tires. In...-0033; Notice 2] Goodyear Tire and Rubber Company, Grant of Petition for Decision of Inconsequential.... SUMMARY: Goodyear Tire and Rubber Company,(Goodyear),\\1\\ has determined that approximately 26,224 Goodyear...

Are you overloading you skidder tires?

Treesearch

Cleveland J. Biller; Cleveland J. Biller

1972-01-01

The undersize and underinflated tire is one of the costliest problems in Appalachian logging. Overloaded and underinflated tires cause excessive wear and expensive early replacement. In seeking a solution to this problem, we have developed a method that can be used for choosing the correct tire size and inflation pressure for a particular skidder.

Impacts of environmental conditions on the sorption of volatile organic compounds onto tire powder.

PubMed

Oh, Dong I; Nam, Kyongphile; Park, Jae W; Khim, Jee H; Kim, Yong K; Kim, Jae Y

2008-05-01

A series of batch tests were performed and the impacts of environmental conditions and phase change on the sorption of volatile organic compounds (VOCs) were investigated. Benzene, trichloroethylene, tetrachloroethylene, and ethylbenzene were selected as target VOCs. Sorption of VOCs onto tire powder was well demonstrated by a linear-partitioning model. Water-tire partition coefficients of VOCs (not tested in this study) could be estimated using a logarithmic relationship between observed water-tire partition coefficients and octanol-water partition coefficients of the VOCs tested. The target VOCs did not seem to compete with other VOCs significantly when sorbed onto the tire powder for the range of concentrations tested. The influence of environmental conditions, such as pH and ionic strength also did not seem to be significant. Water-tire partition coefficients of benzene, trichloroethylene, tetrachloroethylene, and ethylbenzene decreased as the sorbent dosage increased. However, they showed stable values when the sorbent dosage was greater than 10 g/L. Air-tire partition coefficient could be extrapolated from Henry's law constants and water-tire partition coefficient of VOCs.

Pathology of non-thermal irreversible electroporation (N-TIRE)-induced ablation of the canine brain.

PubMed

Rossmeisl, John H; Garcia, Paulo A; Roberston, John L; Ellis, Thomas L; Davalos, Rafael V

2013-01-01

This study describes the neuropathologic features of normal canine brain ablated with non-thermal irreversible electroporation (N-TIRE). The parietal cerebral cortices of four dogs were treated with N-TIRE using a dose-escalation protocol with an additional dog receiving sham treatment. Animals were allowed to recover following N-TIRE ablation and the effects of treatment were monitored with clinical and magnetic resonance imaging examinations. Brains were subjected to histopathologic and ultrastructural assessment along with Bcl-2, caspase-3, and caspase-9 immunohistochemical staining following sacrifice 72 h post-treatment. Adverse clinical effects of N-TIRE were only observed in the dog treated at the upper energy tier. MRI and neuropathologic examinations indicated that N-TIRE ablation resulted in focal regions of severe cytoarchitectural and blood-brain-barrier disruption. Lesion size correlated to the intensity of the applied electrical field. N-TIRE-induced lesions were characterized by parenchymal necrosis and hemorrhage; however, large blood vessels were preserved. A transition zone containing parenchymal edema, perivascular inflammatory cuffs, and reactive gliosis was interspersed between the necrotic focus and normal neuropil. Apoptotic labeling indices were not different between the N-TIRE-treated and control brains. This study identified N-TIRE pulse parameters that can be used to safely create circumscribed foci of brain necrosis while selectively preserving major vascular structures.

Use of shredded tire chips and tire crumbs as packing media in trickling filter systems for landfill leachate treatment.

PubMed

Mondal, B; Warith, M A

2008-08-01

Scrap tire stockpiles are breeding grounds for pests, mosquitoes and west Nile viruses and, thereby, become a potential health risk. This experimental study was carried out in six stages to determine the suitability of shredded tire materials in a trickling filter system to treat landfill leachate. Biochemical oxygen demand (BOD5), chemical oxygen demand (COD) and NH3-N removals were obtained in the range of 81 to 96%, 76 to 90% and 15 to 68%, respectively. The removal of organics appears to be largely related to total dissolved solids reduction in leachate. A sudden increase, from time to time, in organic content of effluent could be attributed to biomass sloughing and clogging in the trickling filters. However, tire crumbs exhibited more consistent organics removal throughout the experimental program. Due to the high surface area of shredded tire chips and crumbs, a layer of biomass, 1-2 mm thick, was attached to them and was sloughed off at an interval of 21 days. Apart from that, as shredded tires are comparatively cheaper than any other usable packing material, tire chips and tire crumbs appeared to be quite promising as packing media in trickling filters for landfill leachate treatment.

Experimental Investigations on the Pull-Out Behavior of Tire Strips Reinforced Sands.

PubMed

Li, Li-Hua; Chen, Yan-Jun; Ferreira, Pedro Miguel Vaz; Liu, Yong; Xiao, Heng-Lin

2017-06-27

Waste tires have excellent mechanical performance and have been used as reinforcing material in geotechnical engineering; however, their interface properties are poorly understood. To further our knowledge, this paper examines the pull-out characteristics of waste tire strips in a compacted sand, together with uniaxial and biaxial geogrids also tested under the same conditions. The analysis of the results shows that the interlocking effect and pull-out resistance between the tire strip and the sand is very strong and significantly higher than that of the geogrids. In the early stages of the pull-out test, the resistance is mainly provided by the front portion of the embedded tire strips, as the pull-out test continues, more and more of the areas towards the end of the tire strips are mobilized, showing a progressive failure mechanism. The deformations are proportional to the frictional resistance between the tire-sand interface, and increase as the normal stresses increase. Tire strips of different wear intensities were tested and presented different pull-out resistances; however, the pull-out resistance mobilization patterns were generally similar. The pull-out resistance values obtained show that rubber reinforcement can provide much higher pull-out forces than the geogrid reinforcements tested here, showing that waste tires are an excellent alternative as a reinforcing system, regardless of the environmental advantages.

T.R.I.C.K.-Tire/Road Interaction Characterization & Knowledge - A tool for the evaluation of tire and vehicle performances in outdoor test sessions

NASA Astrophysics Data System (ADS)

Farroni, Flavio

2016-05-01

The most powerful engine, the most sophisticated aerodynamic devices or the most complex control systems will not improve vehicle performances if the forces exchanged with the road are not optimized by proper employment and knowledge of tires. The vehicle interface with the ground is constituted by the sum of small surfaces, wide about as one of our palms, in which tire/road interaction forces are exchanged. From this it is clear to see how the optimization of tire behavior represents a key-factor in the definition of the best setup of the whole vehicle. Nowadays, people and companies playing a role in automotive sector are looking for the optimal solution to model and understand tire's behavior both in experimental and simulation environments. The studies carried out and the tool developed herein demonstrate a new approach in tire characterization and in vehicle simulation procedures. This enables the reproduction of the dynamic response of a tire through the use of specific track sessions, carried out with the aim to employ the vehicle as a moving lab. The final product, named TRICK tool (Tire/Road Interaction Characterization and Knowledge), comprises of a vehicle model which processes experimental signals acquired from vehicle CAN bus and from sideslip angle estimation additional instrumentation. The output of the tool is several extra "virtual telemetry" channels, based on the time history of the acquired signals and containing force and slip estimations, useful to provide tire interaction characteristics. TRICK results can be integrated with the physical models developed by the Vehicle Dynamics UniNa research group, providing a multitude of working solutions and constituting an ideal instrument for the prediction and the simulation of the real tire dynamics.

Tire Development for Effective Transportation and Utilization of Used Tires, CRADA 01-N044, Final Report

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

Susan M. Maley

Scrap tires represent a significant disposal and recycling challenge for the United States. Over 280 million tires are generated on an annual basis, and several states have large stockpiles or abandoned tire piles that are slated for remediation. While most states have programs to address the accumulation and generation of scrap tires, most of these states struggle with creating and sustaining recycling or beneficial end use markets. One of the major issues with market development has been the costs associated with transporting and processing the tires into material for recycling or disposal. According to a report by the Rubber Manufacturesmore » Association tire-derived fuel (TDF) represents the largest market for scrap tires, and approximately 115 million tires were consumed in 2001 as TDF (U.S. Scrap Tire Markets, 2001, December 2002, www.rma.org/scraptires). This market is supported primarily by cement kilns, followed by various industries including companies that operate utility and industrial boilers. However the use of TDF has not increased and the amount of TDF used by boiler operators has declined. The work completed through this cooperative research and development agreement (CRADA) has shown the potential of a mobile tire shredding unit to economically produce TDF and to provide an alterative low cost fuel to suitable coal-fired power systems. This novel system addresses the economic barriers by processing the tires at the retailer, thereby eliminating the costs associated with hauling whole tires. The equipment incorporated into the design allow for small 1-inch chunks of TDF to be produced in a timely fashion. The TDF can then be co-fired with coal in suitable combustion systems, such as a fluidized bed. Proper use of TDF has been shown to boost efficiency and reduce emissions from power generation systems, which is beneficial to coal utilization in existing power plants. Since the original scope of work outlined in the CRADA could not be completed because of lack of progress by the CRADA members, the agreement was not extended beyond February 2004. The work completed included the detailed design of the mobile unit, a general economic analysis of the operating the system, and outreach activities.« less

Single shot ultrafast dynamic ellipsometry (UDE) of laser-driven shocks in single crystal explosives

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

Whitley, Von H; Mcgrane, Shawn D; Moore, David S

2009-01-01

We report on the first experiments to measure states in shocked energetic single crystals with dynamic ellipsometry. We demonstrate that these ellipsometric techniques can produce reasonable Hugoniot values using small amounts of crystalline RDX and PETN. Pressures, particle velocities and shock velocities obtained using shocked ellipsometry are comparable to those found using gas-gun flyer plates and molecular dynamics calculations. The adaptation of the technique from uniform thin films of polymers to thick non-perfect crystalline materials was a significant achievement. Correct sample preparation proved to be a crucial component. Through trial and error, we were able to resolve polishing issues, samplemore » quality problems, birefringence effects and mounting difficulties that were not encountered using thin polymer films.« less

Organic/carbon nanotubes hybrid thin films for chemical detection

NASA Astrophysics Data System (ADS)

Banimuslem, Hikmat Adnan

Metallophthalocyanines (MPcs) are classified as an important class of conjugated materials and they possess several advantages attributed to their unique chemical structure. Carbon nanotubes (CNT), on the other hand, are known to enhance the properties of nano-composites in the conjugated molecules, due to their one dimensional electronic skeleton, high surface area and high aspect ratio. In this thesis, work has been carried out on the investigation of different substituted metal-phthalocyanines with the aim of developing novel hybrid film structures which incorporates these phthalocyanines and single-walled carbon nanotubes (SWCNT) for chemical detection applications. Octa-substituted copper phthalocyanines (CuPcR[8]) have been characterised using UV-visible absorption spectroscopy. Obtained spectra have yielded an evidence of a thermally induced molecular reorganization in the films. Influence of the nature of substituents in the phthalocyanine molecule on the thin films conductivity was also investigated. Octa-substituted lead (II) phthalocyanines (PbPcR[8]) have also been characterized using UV-visible spectroscopy. Sandwich structures of ITO/PbPcR[8]/In were prepared to investigate the electronic conduction in PbPcR[8]. The variation in the J(V) behavior of the films as a result of heat treatment is expected to be caused by changes in the alignment inside the columnar stacking of the molecules of the films. Thin films of non-covalently hybridised SWCNT and tetra-substituted copper phthalocyanine (CuPcR[4]) molecules have been produced. FTIR, DC conductivity, SEM and AFM results have revealed the [mathematical equation]; interaction between SWCNTs and CuPCR[4] molecules and shown that films obtained from the acid-treated SWCNTs/CuPcR[4] hybrids demonstrated more homogenous surface. Thin films of pristine CuPCR[4] and CuPcR[4]/S WCNT were prepared by spin coating onto gold-coated glass slides and applied as active layers for the detection of benzo[a]pyrene, pentachlorophenol (PCP), 2-chlorophenol, diuron and simazine in water as well as amines vapours in ambient air utilizing total internal reflection spectroscopic ellipsometry (TIRE) as an optical detection method. Different concentrations of pesticides in water ranging from 1 to 25 mug/L have been examined. It was revealed that the shifts in [mathematical equation] spectra of CuPcR[4]SWCNT films were evidently larger than those produced by the pristine CuPcR[4] films, indicating largely improved films' sensitivity of the hybrid films. Adsorption of amines onto films' surfaces has been realised by monitoring changes in the phase shift [mathematical equation] of TIRE. Methylamine has shown higher sensitivity and lower response time among the studied amines. For all amines vapours, the sensitivity of SWCNT/CuPcR[4] hybrid films was higher than the sensitivity of pristine Cu[1]PCR[4] films. Further work has been carried out on hybrids of SWCNT with zinc phthalocyanines (ZnPc). Thin films of pristine SWCNT and SWCNT/ZnPc hybrids were prepared by drop casting onto interdigitated electrodes and applied as active layers to detect ammonia vapor by measuring electrical resistance changes. Influence of pyrene substituent in the phthalocyanine ring on the hybrid formation and their sensor response has also been verified.

41 CFR 101-25.110-2 - Tires obtained through Federal Supply Schedules or regional term contracts.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Federal Supply Schedules or regional term contracts. 101-25.110-2 Section 101-25.110-2 Public Contracts... REGULATIONS SUPPLY AND PROCUREMENT 25-GENERAL 25.1-General Policies § 101-25.110-2 Tires obtained through Federal Supply Schedules or regional term contracts. When tire manufacturers ship tires direct against...

41 CFR 101-25.110-2 - Tires obtained through Federal Supply Schedules or regional term contracts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Federal Supply Schedules or regional term contracts. 101-25.110-2 Section 101-25.110-2 Public Contracts... REGULATIONS SUPPLY AND PROCUREMENT 25-GENERAL 25.1-General Policies § 101-25.110-2 Tires obtained through Federal Supply Schedules or regional term contracts. When tire manufacturers ship tires direct against...

78 FR 38443 - Chrysler Group, LLC, Grant of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-26

... tire change and placed on the subject vehicles. However, 729 vehicles that received the updated vehicle placard were fitted with the Yokahama tires instead of the Kumbo tires. Chrysler stated its belief that... weight rating (GVWR) of the vehicles is not affected by the tire change. Chrysler also notes that the...

29 CFR 779.366 - Recapping or retreading tires for sale.

Code of Federal Regulations, 2010 CFR

2010-07-01

... retail establishment in the industry if not more than 50 percent of the annual dollar volume of its sales... 29 Labor 3 2010-07-01 2010-07-01 false Recapping or retreading tires for sale. 779.366 Section 779... Establishments Automotive Tire Establishments § 779.366 Recapping or retreading tires for sale. (a) Some...

77 FR 71678 - The Goodyear Tire & Rubber Company, Receipt of Petition for Decision of Inconsequential...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-03

...: The Goodyear Tire & Rubber Company (GOODYEAR),\\1\\ has determined that certain Goodyear brand tires... LT 275/65R18 brand tires manufactured between April 8, 2012, and May 12, 2012 at its plant in Gadsden.... Electronically: By logging onto the Federal Docket Management System (FDMS) Web site at http://www.regulations...

77 FR 71679 - Bridgestone Americas Tire Operations, LLC, Receipt of Petition for Decision of Inconsequential...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-03

... Bridgestone brand tires manufactured between June 19, 2011 and March 17, 2012, do not fully comply with... brand tires manufactured between June 19, 2011, and March 17, 2012. Only 97 of the affected tires are no.... c. Electronically: by logging onto the Federal Docket Management System (FDMS) Web site at http...

77 FR 11189 - Yokohama Tire Corporation, Denial of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-24

... full Tire Identification Number (TIN) on one sidewall but omit the partial serial number on the other....'' YTC explained its belief that the Tire Identification Number (TIN) and the partial TIN are used to... TIN is molded on the intended outboard sidewall of these tires and consumers could be directed to have...

77 FR 4996 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Rescission of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-01

...-the-Road Tires From the People's Republic of China: Rescission of Countervailing Duty Administrative... countervailing duty order on certain new pneumatic off-the-road tires (OTR Tires) from the People's Republic of..., Office 6, ``Administrative Review of the Countervailing Duty Order on Certain New Pneumatic Off-the-road...

49 CFR 571.109 - Standard No. 109; New pneumatic and certain specialty tires.

Code of Federal Regulations, 2014 CFR

2014-10-01

... deformation and allows no loss of air through the portion that it comprises of the tire-rim pressure chamber... rim that undergoes no permanent deformation and allows no loss of air through the portion that it... Safety Standard No. 109 The following tables list tire sizes and tire constructions with proper load and...

Results from recent NASA tire thermal studies

NASA Technical Reports Server (NTRS)

Mccarty, J. L.

1983-01-01

The testing technique and some results from an experimental study to determine tire temperature profiles to aid in defining the strength and fatigue limitations of the tire carcass structure are described. This effort is part of a program to explore analytically and through experiment the temperature distribution in an aircraft tire during free roll and braked and yawed rolling conditions.

76 FR 31584 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Extension of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-01

...-the-Road Tires From the People's Republic of China: Extension of Preliminary Results of Antidumping... for the preliminary results of the administrative review of certain new pneumatic off-the-road tires... on certain new pneumatic off-the-road tires from the PRC. See Initiation of Antidumping and...

49 CFR 570.62 - Tires.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Tires. 570.62 Section 570.62 Transportation Other... § 570.62 Tires. (a) Tread depth. The tread shall be not less than four thirty-seconds of an inch deep on each front tire of any vehicle other than a trailer and not less than two thirty-seconds of an inch on...

26 CFR 48.4073-2 - Exemption of tires with internal wire fastening.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Exemption of tires with internal wire fastening... internal wire fastening. The tax does not apply to sales of tires of any size or dimension manufactured from extruded tiring that is fastened or held together by means of internal wire or other metallic...

26 CFR 48.4073-2 - Exemption of tires with internal wire fastening.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 16 2011-04-01 2011-04-01 false Exemption of tires with internal wire fastening... internal wire fastening. The tax does not apply to sales of tires of any size or dimension manufactured from extruded tiring that is fastened or held together by means of internal wire or other metallic...

75 FR 17827 - Goodyear Tire & Rubber Company, Grant of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

... measurable effect on the safety of the tire retread, repair, and recycling industries. The use of steel cord... effect of the noncompliance on the operational safety of vehicles on which these tires are mounted. The safety of people working in the tire retread, repair, and recycling industries must also be considered...

24 CFR 3280.904 - Specific requirements for designing the transportation system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... the tire and manufactured home frame or structure to permit unimpeded wheel movement and for changing... alternatives listed in § 3280.903(c) may be accepted in place of such an analysis. (7) Hubs and bearings. Hubs...) Tires, wheels and rims. Tires, wheels and rims shall meet the requirements of § 3280.904(b)(3). Tires...

Tire/wheel concept

NASA Technical Reports Server (NTRS)

Harper, P. M., Sr. (Inventor)

1981-01-01

A tire and wheel assembly is disclosed in which a low profile pneumatic tire (having sidewalls which deflect inwardly under load) and a wheel (having a rim featuring a narrow central channel and extended rim flanges) form the combination. The extended rim flanges support the tire sidewalls under static and dynamic loading conditions to produce a combination particularly suited to aircraft applications.

24 CFR 3280.904 - Specific requirements for designing the transportation system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... the tire and manufactured home frame or structure to permit unimpeded wheel movement and for changing... alternatives listed in § 3280.903(c) may be accepted in place of such an analysis. (7) Hubs and bearings. Hubs...) Tires, wheels and rims. Tires, wheels and rims shall meet the requirements of § 3280.904(b)(3). Tires...

24 CFR 3280.904 - Specific requirements for designing the transportation system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... the tire and manufactured home frame or structure to permit unimpeded wheel movement and for changing... alternatives listed in § 3280.903(c) may be accepted in place of such an analysis. (7) Hubs and bearings. Hubs...) Tires, wheels and rims. Tires, wheels and rims shall meet the requirements of § 3280.904(b)(3). Tires...

24 CFR 3280.904 - Specific requirements for designing the transportation system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... the tire and manufactured home frame or structure to permit unimpeded wheel movement and for changing... alternatives listed in § 3280.903(c) may be accepted in place of such an analysis. (7) Hubs and bearings. Hubs...) Tires, wheels and rims. Tires, wheels and rims shall meet the requirements of § 3280.904(b)(3). Tires...

49 CFR 571.129 - Standard No. 129; New non-pneumatic tires for passenger cars.

Code of Federal Regulations, 2013 CFR

2013-10-01

...-pneumatic tire assembly incorporates a wheel, supports the tire, and attaches, either integrally or... directly or through a wheel or wheel center member, the vertical load and tractive forces from the roadway... assembly means a non-pneumatic tire, alone or in combination with a wheel or wheel center member, which can...

75 FR 74003 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Partial Rescission...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-30

...-the-Road Tires From the People's Republic of China: Partial Rescission of Countervailing Duty... the countervailing duty order on certain new pneumatic off-the-road tires (OTR Tires) from the People... Guizhou Tyre Co., Ltd., Guizhou Advanced Rubber Co., Ltd., and Guizhou Tyre Import and Export Corporation...

76 FR 14919 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Notice of Partial...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-18

...-the-Road Tires From the People's Republic of China: Notice of Partial Rescission of Antidumping Duty.... DATES: Effective Date: March 18, 2011. FOR FURTHER INFORMATION CONTACT: Raquel Silva or Frances Veith... antidumping duty order on certain new pneumatic off-the-road tires (``OTR tires'') from the People's Republic...

75 FR 76956 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Rescission, in Part...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-10

...-the-Road Tires From the People's Republic of China: Rescission, in Part, of Countervailing Duty... the countervailing duty order on certain new pneumatic off-the-road tires (OTR Tires) from the People... the following seven companies: Shandong Huitong Tyre Co., Ltd.; Qingdao Hengda Tyres Co., Ltd...

75 FR 24884 - Certain New Pneumatic Off-the-Road Tires from the People's Republic of China: Partial Rescission...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-06

...-the-Road Tires from the People's Republic of China: Partial Rescission of Countervailing Duty... the countervailing duty order on Certain New Pneumatic Off-the-Road Tires (OTR Tires) from the People...: May 6, 2010. FOR FURTHER INFORMATION CONTACT: Andrew Huston, AD/CVD Operations, Office 6, Import...

Reduction of the shimmy tendency of tail and nose-wheel landing gears by installation of specially designed tires

NASA Technical Reports Server (NTRS)

Schrode, H

1955-01-01

Shimmy of tail and nose wheels may be eliminated by installation of dampers and use of large trail; however, this produces construction and operational disadvantages. It is more favorable to employ, instead of the customary tail-wheel tires, tires with lesser shimmy tendency. A description of the best possible form for these tires follows: furthermore, a few general concepts regarding the effects of the condition of the tire, of the type of rolling motion, and of the landing, are discussed.

Effect of Tire Pressure to Physical Workload at Operating a Manual Wheelchair.

PubMed

Booka, Masayuki; Yoneda, Ikuo; Hashizume, Tsutomu; Lee, Hokyoo; Oku, Hidehisa; Fujisawa, Shoichiro

2015-01-01

It is often experienced that low tire pressure of the wheelchair not only increases running resistance, but also reduces parking brake performance. In this study, the required driving forces for different tire pressures were experimentally measured and evaluated. It was indicated from the result that the wheelchair with proper tire pressure could be run with less workload of wheelchair-user. Then it was also indicated that the wheelchair with a lower tire pressure needed more workload of wheelchair-user even on hard level surface.

Aircraft radial-belted tire evaluation

NASA Technical Reports Server (NTRS)

Yager, Thomas J.; Stubbs, Sandy M.; Davis, Pamela A.

1990-01-01

An overview is given of the ongoing joint NASA/FAA/Industry Surface Traction And Radial Tire (START) Program being conducted at NASA Langley's Aircraft Landing Dynamics Facility (ALDF). The START Program involves tests using three different tire sizes to evaluate tire rolling resistance, braking, and cornering performance throughout the aircraft ground operational speed range for both dry and wet runway surfaces. Preliminary results from recent 40 x 14 size bias-ply, radial-belted, and H-type aircraft tire tests are discussed. The paper concludes with a summary of the current program status and planned ALDF test schedule.

Comparison of 30x11.5 - 14.5 bias-ply and radial-belted tire characteristics

NASA Technical Reports Server (NTRS)

Davis, Pamela A.

1992-01-01

An investigation at NASA Langley Research Center was conducted to determine the static and dynamic mechanical characteristics of 30x11.5-14.5, Type VIII, bias-ply and radial-belted aircraft tires. The tire characteristics were determined by application of vertical and fore-and-aft loads. The results of the study are presented to show static load deflection curves, hysteresis losses, and stiffness and damping characteristics of each tire type tested. The advantages and disadvantages of each type of tire are also given.

Uncontacted tire explosion causing trauma to bilateral lower extremities: A case report.

PubMed

Yu, Ming-Yang; Su, Yun; Meng, Xiang-Jun; Luan, Bo-Wu; Gu, Gui-Shan; Sun, Qiang; Zhao, De-Wei

2017-06-01

It is uncommon for tire explosion related injuries on the lower extremity. The bilateral lower extremities were injured by tire explosion when the patient was seated in a bus. She sustained an open fracture with partial bone loss in the right calcaneus (a comminuted fracture in the right ankle joint) and a closed comminuted fracture in the left tibia and fibula. This damage was caused by uncontacted tire explosion, thanks to a thick floor between the exploded tire and the patient's feet. This type of injury on lower extremity caused by uncontacted tire explosion was uncommon. Copyright © 2017 Daping Hospital and the Research Institute of Surgery of the Third Military Medical University. Production and hosting by Elsevier B.V. All rights reserved.

An investigation of green iridescence on the mollusc Patella granatina

NASA Astrophysics Data System (ADS)

Brink, D. J.; van der Berg, N. G.

2005-01-01

In this paper we investigate the relatively rare phenomenon of iridescence on the outer surface of seashells (not the well known pearly inner surfaces). Using reflection spectroscopy and scanning electron microscopy we show that rows of iridescent green spots on the mollusc Patella granatina are caused by a thin-film stack buried about 100 µm below the rough outer surface of the shell. The high-density layers in the stack seem to be made of crystalline aragonite, but according to Raman spectroscopy and ellipsometry measurements the low-density layers as well as the bulk of the shell wall are a mixture of porous aragonite and organic materials such as carotenoids.

Water desorption from a confined biopolymer.

PubMed

Pradipkanti, L; Satapathy, Dillip K

2018-03-14

We study desorption of water from a confined biopolymer (chitosan thin films) by employing temperature dependent specular X-ray reflectivity and spectroscopic ellipsometry. The water desorption is found to occur via three distinct stages with significantly different desorption rates. The distinct rates of water desorption are attributed to the presence of different kinds of water with disparate mobilities inside the biopolymer film. We identify two characteristic temperatures (T c1 and T c2 ) at which the water desorption rate changes abruptly. Interestingly, the characteristic temperatures decrease with decreasing the film thickness. The thickness dependence of the characteristic temperature is interpreted in the context of a higher mobility of polymer chains at the free surface for polymers under one-dimensional confinement.

Jet Fuel Thermal Stability Investigations using Ellipsometry

NASA Technical Reports Server (NTRS)

Nash, Leigh; Klettlinger, Jennifer; Vasu, Subith

2017-01-01

Ellipsometry is an optical technique used to measure the thickness of thin films. This technique was used to measure the thickness of deposits created by heated jet fuel, specifically Sasol IPK on stainless steel tubes. A new amorphous model was used to iteratively determine the film thickness. This method was found to be repeatable, and the thickness of deposit increased with increasing temperature and increasing concentration of naphthalene.

A Procedure for Determining Tire-Road Friction Characteristics Using a Modification of the Magic Formula Based on Experimental Results

PubMed Central

Pérez, Javier; Velasco, Juan M.; Guerra, Antonio J.; Hernández, Pedro

2018-01-01

Knowledge of tire-road friction characteristics is essential for the proper performance of most relevant vehicle active safety systems. Therefore, its determination is necessary to improve the effectiveness of these systems and to avoid or reduce the consequences of traffic accidents. For this reason, there is a great deal of literature concerning methods and devices for measuring and modeling tire-road friction. Most of these methods have focused on determining the road friction resistance, taking only road composition and making measurements in wet conditions into account. However, friction forces are also dependent on the tire type, since the contact is established between the tire and the road in real driving conditions. Thus, the type and characteristics of the tire have to be considered in the study of the interaction between the vehicle and the road. The aim of this work is to unify the study of the friction coefficient, taking into consideration the two existing bodies involved in the contact, i.e., the tire and road and the main factors that influence the forces in the contact. To this end, a modification of the Pacejka Magic Formula is proposed to include the effects of the main parameters that influence the contact, such as road composition and its state, tire type, vehicle speed, and slip between the tire and the road. To do so, real tests have been conducted on several roads and with different operating conditions. As a result, a more accurate tire-road friction model has been obtained. PMID:29562623

A Procedure for Determining Tire-Road Friction Characteristics Using a Modification of the Magic Formula Based on Experimental Results.

PubMed

Cabrera, Juan A; Castillo, Juan J; Pérez, Javier; Velasco, Juan M; Guerra, Antonio J; Hernández, Pedro

2018-03-17

Knowledge of tire-road friction characteristics is essential for the proper performance of most relevant vehicle active safety systems. Therefore, its determination is necessary to improve the effectiveness of these systems and to avoid or reduce the consequences of traffic accidents. For this reason, there is a great deal of literature concerning methods and devices for measuring and modeling tire-road friction. Most of these methods have focused on determining the road friction resistance, taking only road composition and making measurements in wet conditions into account. However, friction forces are also dependent on the tire type, since the contact is established between the tire and the road in real driving conditions. Thus, the type and characteristics of the tire have to be considered in the study of the interaction between the vehicle and the road. The aim of this work is to unify the study of the friction coefficient, taking into consideration the two existing bodies involved in the contact, i.e., the tire and road and the main factors that influence the forces in the contact. To this end, a modification of the Pacejka Magic Formula is proposed to include the effects of the main parameters that influence the contact, such as road composition and its state, tire type, vehicle speed, and slip between the tire and the road. To do so, real tests have been conducted on several roads and with different operating conditions. As a result, a more accurate tire-road friction model has been obtained.

A North American model to contain the spread of Aedes albopictus through tire legislation.

PubMed

Novak, R J

1995-12-01

The introduction, spread, and establishment of the Asian tiger mosquito, Aedes albopictus, in the United States has been facilitated by used or waste tires. This species has not only caused considerable concern among public health officials but also highlighted that the growing accumulations of used tires are a serious solid waste problem and a challenge to the recycling industry. This paper illustrates how the State of Illinois addressed the public health and solid waste problems associated with waste tires, mosquitoes and mosquito-borne pathogens. The goal of the State was to develop and implement through legislative process the Illinois Waste Tire Act. The purpose of the Waste Tire Act is: 1) to ensure that used and waste tires are collected for disposal and recycling, 2) to provide for the abatement of used and waste tire dumps and associated threats to public health, 3) to encourage the development of used and waste tire processing facilities and technologies, including energy recovery, and 4) to provide for research on vectors associated with used and waste tires, and the diseases they spread. The discussion will include key statutes from the Act and the model used to coordinate the effort of five different governmental agencies. An up-to-date presentation of vector-related research, mandated by the Act, ranging from applied investigations on mosquito control to more basic studies investigations on virus identification using molecular technology will be discussed. Finally a discussion of problems that have been encountered along with solutions dealing with legislative language, multidisciplined agency efforts and interactions with the general public are presented.

Predicting the compressibility behaviour of tire shred samples for landfill applications.

PubMed

Warith, M A; Rao, Sudhakar M

2006-01-01

Tire shreds have been used as an alternative to crushed stones (gravel) as drainage media in landfill leachate collection systems. The highly compressible nature of tire shreds (25-47% axial strain on vertical stress applications of 20-700 kPa) may reduce the thickness of the tire shred drainage layer to less than 300 mm (minimum design requirement) during the life of the municipal solid waste landfill. There hence exists a need to predict axial strains of tire shred samples in response to vertical stress applications so that the initial thickness of the tire shred drainage layer can be corrected for compression. The present study performs one-dimensional compressibility tests on four tire shred samples and compares the results with stress/strain curves from other studies. The stress/strain curves are developed into charts for choosing the correct initial thickness of tire shred layers that maintain the minimum thickness of 300 mm throughout the life of the landfill. The charts are developed for a range of vertical stresses based on the design height of municipal waste cell and bulk unit weight of municipal waste. Experimental results also showed that despite experiencing large axial strains, the average permeability of the tire shred sample consistently remained two to three orders of magnitude higher than the design performance criterion of 0.01cm/s for landfill drainage layers. Laboratory experiments, however, need to verify whether long-term chemical and bio-chemical reactions between landfill leachate and the tire shred layer will deteriorate their mechanical functions (hydraulic conductivity, compressibility, strength) beyond permissible limits for geotechnical applications.

An algorithm for the kinetics of tire pyrolysis under different heating rates.

PubMed

Quek, Augustine; Balasubramanian, Rajashekhar

2009-07-15

Tires exhibit different kinetic behaviors when pyrolyzed under different heating rates. A new algorithm has been developed to investigate pyrolysis behavior of scrap tires. The algorithm includes heat and mass transfer equations to account for the different extents of thermal lag as the tire is heated at different heating rates. The algorithm uses an iterative approach to fit model equations to experimental data to obtain quantitative values of kinetic parameters. These parameters describe the pyrolysis process well, with good agreement (r(2)>0.96) between the model and experimental data when the model is applied to three different brands of automobile tires heated under five different heating rates in a pure nitrogen atmosphere. The model agrees with other researchers' results that frequencies factors increased and time constants decreased with increasing heating rates. The model also shows the change in the behavior of individual tire components when the heating rates are increased above 30 K min(-1). This result indicates that heating rates, rather than temperature, can significantly affect pyrolysis reactions. This algorithm is simple in structure and yet accurate in describing tire pyrolysis under a wide range of heating rates (10-50 K min(-1)). It improves our understanding of the tire pyrolysis process by showing the relationship between the heating rate and the many components in a tire that depolymerize as parallel reactions.

Experimental Investigations on the Pull-Out Behavior of Tire Strips Reinforced Sands

PubMed Central

Li, Li-Hua; Chen, Yan-Jun; Ferreira, Pedro Miguel Vaz; Liu, Yong; Xiao, Heng-Lin

2017-01-01

Waste tires have excellent mechanical performance and have been used as reinforcing material in geotechnical engineering; however, their interface properties are poorly understood. To further our knowledge, this paper examines the pull-out characteristics of waste tire strips in a compacted sand, together with uniaxial and biaxial geogrids also tested under the same conditions. The analysis of the results shows that the interlocking effect and pull-out resistance between the tire strip and the sand is very strong and significantly higher than that of the geogrids. In the early stages of the pull-out test, the resistance is mainly provided by the front portion of the embedded tire strips, as the pull-out test continues, more and more of the areas towards the end of the tire strips are mobilized, showing a progressive failure mechanism. The deformations are proportional to the frictional resistance between the tire-sand interface, and increase as the normal stresses increase. Tire strips of different wear intensities were tested and presented different pull-out resistances; however, the pull-out resistance mobilization patterns were generally similar. The pull-out resistance values obtained show that rubber reinforcement can provide much higher pull-out forces than the geogrid reinforcements tested here, showing that waste tires are an excellent alternative as a reinforcing system, regardless of the environmental advantages. PMID:28773069

77 FR 11190 - Yokohama Tire Company, Denial of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-24

... (TIN)/partial TIN required by paragraph S5.5.1 on one of the tire sidewalls. YTC indicates that the noncompliant tires do however include the full TIN on the intended outboard sidewall. YTC argues that the TIN and the partial TIN are used to properly identify tires that are involved in a safety campaign. YTC...

78 FR 73560 - Certain Off-The-Road Tires From China; Scheduling of an Expedited Five-Year Review Concerning the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-06

... Off-The-Road Tires From China; Scheduling of an Expedited Five-Year Review Concerning the Countervailing Duty Order and Antidumping Duty Order On Certain Off-The-Road Tires From China AGENCY: United... order on certain off-the-road tires from China would be likely to lead to continuation or recurrence of...

78 FR 33059 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Rescission of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-03

...-the-Road Tires From the People's Republic of China: Rescission of Antidumping Duty Administrative... order on certain new pneumatic off-the-road tires from the People's Republic of China (``PRC'') for the... antidumping duty order on certain new pneumatic off-the-road tires, with respect to the above-named companies...

76 FR 4287 - New Pneumatic Off-the-Road Tires From the People's Republic of China: Extension of Time Limit for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-25

... Tires From the People's Republic of China: Extension of Time Limit for Final Results of Countervailing... administrative review of the countervailing duty order on certain new pneumatic off-the-road tires from the People's Republic of China. See New Pneumatic Off-the-Road Tires From the People's Republic of China...

75 FR 32159 - Certain New Pneumatic Off-the-Road Tires from the People's Republic of China: Extension of Time...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-07

...-the-Road Tires from the People's Republic of China: Extension of Time Limit for Preliminary Results of... administrative review of the countervailing duty order on certain new pneumatic off-the-road tires from the... States: Hebei Starbright Tire Co., Ltd. Extension of Time Limit for the Preliminary Results Section 751(a...

49 CFR 574.7 - Information requirements-new tire manufacturers, new tire brand name owners.

Code of Federal Regulations, 2011 CFR

2011-10-01

... lease to tire purchasers. (2) Each tire registration form provided to independent distributors and... following physical characteristics: (A) Be rectangular; (B) Be not less than 31/2 inches high, 5 inches long, and 0.007 inches thick; (C) Be not more than 41/4 inches high, 6 inches long, and 0.016 inch thick...

Land Vehicle Tire Qualification

DTIC Science & Technology

2010-03-25

separation -Bead damage / separation -Severe open splices and/or liner separations - Tire induced loss of air -Exposed or broken casing -Bulges in tread ...or sidewall *UNCLASSIFIED* SAE J2014 11 SAE J2014 4.14 Tire Treadlife Durability -10000 miles duration -Evaluate tread wear performance of candidate... tire -Measurements at prescribed intervals - Tread depth at centerline & shoulder -Diameter, section width, tread arc width -Conducted on courses

77 FR 12812 - Steel Wheels From the People's Republic of China: Notice of Preliminary Affirmative Determination...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-02

... separately. These products are used with both tubed and tubeless tires. Steel wheels, whether or not attached to tires or axles, are included. However, if the steel wheels are imported as an assembly attached to tires or axles, the tire or axle is not covered by the scope. The scope includes steel wheels, discs...

40 CFR 1037.801 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... resistance tire means a tire on a vocational vehicle with a TRRL at or below of 7.7 kg/metric ton, a steer tire on a tractor with a TRRL at or below 7.7 kg/metric ton, or a drive tire on a tractor with a TRRL at or below 8.1 kg/metric ton. Manufacture means the physical and engineering process of designing...

Effect of Speed on Tire-Soil Interaction and Development of Towed Pneumatic Tire-Soil Model

DTIC Science & Technology

1974-10-01

rigid wheels were per- formed by several researchers under laboratory conditions (Refs. 20 through 22) using the flash X -ray technique. These experiments...Towed Tire-Soil Model ................................... 90 IX Conclusions and Recommendations .............. 95 X References...Velocity Fields ................................. A-1 x Section Page Appendix B - Computer Program Chart for Computation 3- of Tire Performance with

Automobile tires--a potential source of highly carcinogenic dibenzopyrenes to the environment.

PubMed

Sadiktsis, Ioannis; Bergvall, Christoffer; Johansson, Christer; Westerholm, Roger

2012-03-20

Eight tires were analyzed for 15 high molecular weight (HMW) polycyclic aromatic hydrocarbons (PAH), using pressurized fluid extraction. The variability of the PAH concentrations determined between different tires was large; a factor of 22.6 between the lowest and the highest. The relative abundance of the analytes was quite similar regardless of tire. Almost all (92.3%) of the total extractable PAH content was attributed to five PAHs: benzo[ghi]perylene, coronene, indeno[1,2,3-cd]pyrene, benzo[e]pyrene, and benzo[a]pyrene. The difference in the measured PAH content between summer and winter tires varied substantially across manufacturers, making estimates of total vehicle fleet emissions very uncertain. However, when comparing different types of tires from the same manufacturer they had significantly (p = 0.05) different PAH content. Previously, there have been no data available for carcinogenic dibenzopyrene isomers in automobile tires. In this study, the four dibenzopyrene isomers dibenzo[a,l]pyrene, dibenzo[a,e]pyrene, dibenzo[a,i]pyrene, and dibenzo[a,h]pyrene constituted <2% of the sum of the 15 analyzed HMW PAHs. These findings show that automobile tires may be a potential previously unknown source of carcinogenic dibenzopyrenes to the environment.

Intelligent Tires Based on Measurement of Tire Deformation

NASA Astrophysics Data System (ADS)

Matsuzaki, Ryosuke; Todoroki, Akira

From a traffic safety point-of-view, there is an urgent need for intelligent tires as a warning system for road conditions, for optimized braking control on poor road surfaces and as a tire fault detection system. Intelligent tires, equipped with sensors for monitoring applied strain, are effective in improving reliability and control systems such as anti-lock braking systems (ABSs). In previous studies, we developed a direct tire deformation or strain measurement system with sufficiently low stiffness and high elongation for practical use, and a wireless communication system between tires and vehicle that operates without a battery. The present study investigates the application of strain data for an optimized braking control and road condition warning system. The relationships between strain sensor outputs and tire mechanical parameters, including braking torque, effective radius and contact patch length, are calculated using finite element analysis. Finally, we suggested the possibility of optimized braking control and road condition warning systems. Optimized braking control can be achieved by keeping the slip ratio constant. The road condition warning would be actuated if the recorded friction coefficient at a certain slip ratio is lower than a ‘safe’ reference value.

Intelligent tires for improved tire safety using wireless strain measurement

NASA Astrophysics Data System (ADS)

Matsuzaki, Ryosuke; Todoroki, Akira

2008-03-01

From a traffic safety point-of-view, there is an urgent need for intelligent tires as a warning system for road conditions, for optimized braking control on poor road surfaces and as a tire fault detection system. Intelligent tires, equipped with sensors for monitoring applied strain, are effective in improving reliability and control systems such as anti-lock braking systems (ABSs). In previous studies, we developed a direct tire deformation or strain measurement system with sufficiently low stiffness and high elongation for practical use, and a wireless communication system between tires and vehicle that operates without a battery. The present study investigates the application of strain data for an optimized braking control and road condition warning system. The relationships between strain sensor outputs and tire mechanical parameters, including braking torque, effective radius and contact patch length, are calculated using finite element analysis. Finally, we suggested the possibility of optimized braking control and road condition warning systems. Optimized braking control can be achieved by keeping the slip ratio constant. The road condition warning would be actuated if the recorded friction coefficient at a certain slip ratio is lower than a 'safe' reference value.

A Model for Space Shuttle Orbiter Tire Side Forces Based on NASA Landing Systems Research Aircraft Test Results

NASA Technical Reports Server (NTRS)

Carter, John F.; Nagy, Christopher J.; Barnicki, Joseph S.

1997-01-01

Forces generated by the Space Shuttle orbiter tire under varying vertical load, slip angle, speed, and surface conditions were measured using the Landing System Research Aircraft (LSRA). Resulting data were used to calculate a mathematical model for predicting tire forces in orbiter simulations. Tire side and drag forces experienced by an orbiter tire are cataloged as a function of vertical load and slip angle. The mathematical model is compared to existing tire force models for the Space Shuttle orbiter. This report describes the LSRA and a typical test sequence. Testing methods, data reduction, and error analysis are presented. The LSRA testing was conducted on concrete and lakebed runways at the Edwards Air Force Flight Test Center and on concrete runways at the Kennedy Space Center (KSC). Wet runway tire force tests were performed on test strips made at the KSC using different surfacing techniques. Data were corrected for ply steer forces and conicity.

Biological control of mosquitoes in scrap tires in Brownsville, Texas, USA and Matamoros, Tamaulipas, Mexico.

PubMed

Uejio, Christopher K; Hayden, Mary H; Zielinski-Gutierrez, Emily; Lopez, Jose Luis Robles; Barrera, Roberto; Amador, Manuel; Thompson, Gregory; Waterman, Stephen H

2014-06-01

Dengue periodically circulates in southern Texas and neighboring Tamaulipas, Mexico; thus, a closer examination of human and vector ecology at the northern limits of North American transmission may improve prevention activities. Scrap tires produce large mosquito populations and increase the risk of dengue transmission. Some households choose not to pay tire disposal fees, and many tires are illegally dumped in residential areas. Biological control may provide low-cost and environmentally friendly mosquito control. This pilot study evaluated the ability of Mesocyclops longisetus to reduce mosquito populations in existing residential scrap tire piles. Mosquito populations were measured by the number of all mosquito pupae within tires or adult Aedes aegypti and Ae. albopictus near piles. Mesocyclops longisetus treated piles did not significantly reduce total mosquito pupae (P = 0.07) in Matamoros, Mexico. The study also evaluated the efficacy of native Toxorhynchites moctezuma which preferentially colonized tire piles under vegetation cover in Brownsville, TX. Toxorhynchites moctezuma larvae significantly reduced total mosquito pupae, but the strength of control diminished over time.

Occurrence and effects of tire wear particles in the environment--a critical review and an initial risk assessment.

PubMed

Wik, Anna; Dave, Göran

2009-01-01

This review summarizes the existing knowledge on the occurrence of tire wear particles in the environment, and their ecotoxicological effects. A meta-analysis on tire components in the environment revealed that tire wear particles are present in all environmental compartments, including air, water, soils/sediments, and biota. The maximum Predicted Environmental Concentrations (PECs) of tire wear particles in surface waters range from 0.03 to 56 mg l(-1) and the maximum PECs in sediments range from 0.3 to 155 g kg(-1) d.w. The results from our previous long-term studies with Ceriodaphnia dubia and Pseudokirchneriella subcapitata were used to derive Predicted No Effect Concentrations (PNECs). The upper ranges for PEC/PNEC ratios in water and sediment were >1, meaning that tire wear particles present potential risks for aquatic organisms. We suggest that management should be directed towards development and production of more environmentally friendly tires and improved road runoff treatment.

Some effects of grooved runway configurations on aircraft tire braking traction under flooded runway conditions

NASA Technical Reports Server (NTRS)

Byrdsong, T. A.

1973-01-01

An experimental investigation was conducted to study the effect of grooved runway configurations on aircraft tire braking traction on flooded runway surfaces. The investigation was performed, utilizing size 49 x 17, type VII, aircraft tires with an inflation pressure of 170 lb per square inch at ground speeds up to approximately 120 knots. The results of this investigation indicate that when the runway is flooded, grooved surfaces provide better braking traction than an ungrooved surface and, in general, the level of braking traction was found to improve as the tire bearing pressure was increased because of an increase in the groove area of either the surface or the tire tread. Rounding the groove edges tended to degrade the tire braking capability from that developed on the same groove configuration with sharp edges. Results also indicate that braking friction coefficients for the test tires and runway surfaces decreased as ground speed was increased because of the hydroplaning effects.

Friction characteristics of three 30 by 11.5-14.5, type 8, aircraft tires with various tread groove patterns and rubber compounds

NASA Technical Reports Server (NTRS)

Yager, T. J.; Mccarty, J. L.

1977-01-01

A test program was conducted to evaluate friction performance and wear characteristics on wet runways of three 30 x 11.5-14.5, type, aircraft tires having two different tread patterns and natural rubber contents. All test tires had the standard three circumferential groove tread, but two had molded transverse grooves which extended from shoulder to shoulder. The tread rubber content of the two tires with transverse grooves differed in that one had a 100 percent natural rubber tread and the other had a rubber tread composition that was 30 percent synthetic and 70 percent natural. The third test tire had the conventional 100 percent natural rubber tread. Results indicate that the differences in tire tread design and rubber composition do not significantly affect braking and cornering friction capability on wet or dry surfaces. Braking performance of the tires decreases with increased speed, with increased yaw angle and, at higher speeds, with increased wetness of the surface.

Carbon materials derived from waste tires as high-performance anodes in microbial fuel cells.

PubMed

Chen, Wei; Feng, Huajun; Shen, Dongsheng; Jia, Yufeng; Li, Na; Ying, Xianbin; Chen, Ting; Zhou, Yuyang; Guo, Jiayun; Zhou, Mengjiao

2018-03-15

In this study, carbonized waste tires were directly used as a high-performance anode material in microbial fuel cells (MFCs). The effect of the pyrolysis temperature used for waste tire carbonization on the current output performance was investigated to determine the optimal pyrolysis temperature. Thermal gravimetric analysis/differential scanning calorimetry showed that tire carbonization started at 200°C and ended at about 500°C; the weight loss was about 64%. When used in an MFC, the electrode obtained from waste tires carbonized at 800°C gave a current density of 23.1±1.4Am -2 , which is much higher than that achieved with traditional graphite felt anodes (5.5±0.1Am -2 ). The results of this study will be useful in optimizing the design of carbonized waste tire anodes for enhancing MFC performances and will alleviate the environmental problems caused by waste tires. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of substitution monopole models for tire noise sound synthesis

NASA Astrophysics Data System (ADS)

Berckmans, D.; Kindt, P.; Sas, P.; Desmet, W.

2010-01-01

Due to the considerable efforts in engine noise reduction, tire noise has become one of the major sources of passenger car noise nowadays and the demand for accurate prediction models is high. A rolling tire is therefore experimentally characterized by means of the substitution monopole technique, suiting a general sound synthesis approach with a focus on perceived sound quality. The running tire is substituted by a monopole distribution covering the static tire. All monopoles have mutual phase relationships and a well-defined volume velocity distribution which is derived by means of the airborne source quantification technique; i.e. by combining static transfer function measurements with operating indicator pressure measurements close to the rolling tire. Models with varying numbers/locations of monopoles are discussed and the application of different regularization techniques is evaluated.

Simulation research of the tire Basic Relaxation Model in conditions of the wheel cornering angle oscillations

NASA Astrophysics Data System (ADS)

Luty, W.

2016-09-01

- A description of the tire Basic Relaxation Model (BRM) is presented in this paper. Simulation research of the tire BRM model in conditions of oscillatory changes of the wheel cornering angle were performed. During the simulation tests the courses of changes in the value of lateral reaction force, transmitted by the wheel, as a response to the sinusoidal changes in the value of the wheel cornering angle have been presented. There have been compared the simulation results obtained for the model of tire-road interaction in two modes: including and not including the BRM. The simulation results allowed to verify prepared BRM and also to determine the influence of the tire relaxation process on the tire behavior in conditions of dynamic changes of the wheel cornering angle.

Computational strategies for tire monitoring and analysis

NASA Technical Reports Server (NTRS)

Danielson, Kent T.; Noor, Ahmed K.; Green, James S.

1995-01-01

Computational strategies are presented for the modeling and analysis of tires in contact with pavement. A procedure is introduced for simple and accurate determination of tire cross-sectional geometric characteristics from a digitally scanned image. Three new strategies for reducing the computational effort in the finite element solution of tire-pavement contact are also presented. These strategies take advantage of the observation that footprint loads do not usually stimulate a significant tire response away from the pavement contact region. The finite element strategies differ in their level of approximation and required amount of computer resources. The effectiveness of the strategies is demonstrated by numerical examples of frictionless and frictional contact of the space shuttle Orbiter nose-gear tire. Both an in-house research code and a commercial finite element code are used in the numerical studies.

Efficient Computation Of Behavior Of Aircraft Tires

NASA Technical Reports Server (NTRS)

Tanner, John A.; Noor, Ahmed K.; Andersen, Carl M.

1989-01-01

NASA technical paper discusses challenging application of computational structural mechanics to numerical simulation of responses of aircraft tires during taxing, takeoff, and landing. Presents details of three main elements of computational strategy: use of special three-field, mixed-finite-element models; use of operator splitting; and application of technique reducing substantially number of degrees of freedom. Proposed computational strategy applied to two quasi-symmetric problems: linear analysis of anisotropic tires through use of two-dimensional-shell finite elements and nonlinear analysis of orthotropic tires subjected to unsymmetric loading. Three basic types of symmetry and combinations exhibited by response of tire identified.

Sensitivity of tire response to variations in material and geometric parameters

NASA Technical Reports Server (NTRS)

Noor, Ahmed K.; Tanner, John A.; Peters, Jeanne M.

1992-01-01

A computational procedure is presented for evaluating the analytic sensitivity derivatives of the tire response with respect to material and geometric parameters of the tire. The tire is modeled by using a two-dimensional laminated anisotropic shell theory with the effects of variation in material and geometric parameters included. The computational procedure is applied to the case of uniform inflation pressure on the Space Shuttle nose-gear tire when subjected to uniform inflation pressure. Numerical results are presented showing the sensitivity of the different response quantities to variations in the material characteristics of both the cord and the rubber.

Determining thickness and refractive index from free-standing ultra-thin polymer films with spectroscopic ellipsometry

DOE PAGES

Hilfiker, James N.; Stadermann, Michael; Sun, Jianing; ...

2016-08-27

It is a well-known challenge to determine refractive index (n) from ultra-thin films where the thickness is less than about 10 nm. In this paper, we discovered an interesting exception to this issue while characterizing spectroscopic ellipsometry (SE) data from isotropic, free-standing polymer films. Ellipsometry analysis shows that both thickness and refractive index can be independently determined for free-standing films as thin as 5 nm. Simulations further confirm an orthogonal separation between thickness and index effects on the experimental SE data. Effects of angle of incidence and wavelength on the data and sensitivity are discussed. Finally, while others have demonstratedmore » methods to determine refractive index from ultra-thin films, our analysis provides the first results to demonstrate high-sensitivity to the refractive index from ultra-thin layers.« less

Designing optical metamaterial with hyperbolic dispersion based on Al:ZnO/ZnO nano-layered structure using Atomic Layer Deposition technique

DOE PAGES

Kelly, Priscilla; Liu, Mingzhao; Kuznetsova, Lyuba

2016-04-07

In this study, nano-layered Al:ZnO/ZnO hyperbolic dispersion metamaterial with a large number of layers was fabricated using the atomic layer deposition (ALD) technique. Experimental dielectric functions for Al:ZnO/ZnO structures are obtained by an ellipsometry technique in the visible and near-infrared spectral ranges. The theoretical modeling of the Al:ZnO/ZnO dielectric permittivity is done using effective medium approximation. A method for analysis of spectroscopic ellipsometry data is demonstrated to extract the optical permittivity for this highly anisotropic nano-layered metamaterial. The results of the ellipsometry analysis show that Al:ZnO/ZnO structures with a 1:9 ALD cycle ratio exhibit hyperbolic dispersion transition change near 1.8more » μm wavelength.« less

49 CFR 571.139 - Standard No. 139; New pneumatic radial tires for light vehicles.

Code of Federal Regulations, 2014 CFR

2014-10-01

... part of the tire that is made of steel wires, wrapped or reinforced by ply cords and that is shaped to... mechanical device made of rubber, chemicals, fabric and steel or other materials, that, when mounted on an....Test sample. For the tests specified in S6, use: (a) One tire for high speed; (b) Another tire for...

49 CFR 571.139 - Standard No. 139; New pneumatic radial tires for light vehicles.

Code of Federal Regulations, 2013 CFR

2013-10-01

... part of the tire that is made of steel wires, wrapped or reinforced by ply cords and that is shaped to... mechanical device made of rubber, chemicals, fabric and steel or other materials, that, when mounted on an....Test sample. For the tests specified in S6, use: (a) One tire for high speed; (b) Another tire for...

49 CFR 571.139 - Standard No. 139; New pneumatic radial tires for light vehicles.

Code of Federal Regulations, 2012 CFR

2012-10-01

... part of the tire that is made of steel wires, wrapped or reinforced by ply cords and that is shaped to... mechanical device made of rubber, chemicals, fabric and steel or other materials, that, when mounted on an....Test sample. For the tests specified in S6, use: (a) One tire for high speed; (b) Another tire for...

78 FR 51271 - Michelin North America, Inc., Moot of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-20

... tires sidewall markings on the opposite side of the full DOT TIN are lacking the designation ``Extra... tires lack the marking ``Extra Load'' on the sidewall opposite of the full DOT TIN as required by FMVSS... subject tires are mounted on a vehicle, the left side tires on the vehicle will show the full DOT TIN and...

49 CFR 571.110 - Tire selection and rims and motor home/recreation vehicle trailer load carrying capacity...

Code of Federal Regulations, 2014 CFR

2014-10-01

..., equipped with passenger car tires, the vehicle normal load on the tire shall be no greater than 94 percent..., the vehicle normal load on the tire shall be no greater than 94 percent of the load rating at the... vehicle trailer load carrying capacity information for motor vehicles with a GVWR of 4,536 kilograms (10...

49 CFR 571.110 - Tire selection and rims and motor home/recreation vehicle trailer load carrying capacity...

Code of Federal Regulations, 2012 CFR

2012-10-01

..., equipped with passenger car tires, the vehicle normal load on the tire shall be no greater than 94 percent..., the vehicle normal load on the tire shall be no greater than 94 percent of the load rating at the... vehicle trailer load carrying capacity information for motor vehicles with a GVWR of 4,536 kilograms (10...

49 CFR 571.110 - Tire selection and rims and motor home/recreation vehicle trailer load carrying capacity...

Code of Federal Regulations, 2011 CFR

2011-10-01

..., equipped with passenger car tires, the vehicle normal load on the tire shall be no greater than 94 percent..., the vehicle normal load on the tire shall be no greater than 94 percent of the load rating at the... vehicle trailer load carrying capacity information for motor vehicles with a GVWR of 4,536 kilograms (10...

49 CFR 571.110 - Tire selection and rims and motor home/recreation vehicle trailer load carrying capacity...

Code of Federal Regulations, 2013 CFR

2013-10-01

..., equipped with passenger car tires, the vehicle normal load on the tire shall be no greater than 94 percent..., the vehicle normal load on the tire shall be no greater than 94 percent of the load rating at the... vehicle trailer load carrying capacity information for motor vehicles with a GVWR of 4,536 kilograms (10...

49 CFR 571.110 - Tire selection and rims and motor home/recreation vehicle trailer load carrying capacity...

Code of Federal Regulations, 2010 CFR

2010-10-01

..., equipped with passenger car tires, the vehicle normal load on the tire shall be no greater than 94 percent..., the vehicle normal load on the tire shall be no greater than 94 percent of the load rating at the... vehicle trailer load carrying capacity information for motor vehicles with a GVWR of 4,536 kilograms (10...

40 CFR Table 11 to Subpart Xxxx of... - Minimum Data for Continuous Compliance With the Emission Limits for Tire Cord Production Affected...

Code of Federal Regulations, 2010 CFR

2010-07-01

... With the Emission Limits for Tire Cord Production Affected Sources 11 Table 11 to Subpart XXXX of Part... for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 11 Table 11 to Subpart XXXX of Part 63—Minimum Data for Continuous Compliance With the Emission Limits for Tire Cord...

A Planar Quasi-Static Constraint Mode Tire Model

DTIC Science & Technology

2015-07-10

strikes a balance between simple tire models that lack the fidelity to make accurate chassis load predictions and computationally intensive models that...strikes a balance between heuristic tire models (such as a linear point-follower) that lack the fidelity to make accurate chassis load predictions...UNCLASSIFIED: Distribution Statement A. Cleared for public release A PLANAR QUASI-STATIC CONSTRAINT MODE TIRE MODEL Rui Maa John B. Ferris

77 FR 16892 - BMW of North America, LLC, Grant of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-22

... certain BMW vehicles equipped with ``run-flat'' tires do not fully comply with paragraphs S4.3(c) and S4.3... equipped with ``run flat'' tires are affected. The affected vehicle models are certain: Model Year 2008... equipped with ``run-flat'' tires and have no spare tire, the word ``none,'' as required by paragraphs S4.3...

Quasi-Static Viscoelasticity Loading Measurements of an Aircraft Tire

NASA Technical Reports Server (NTRS)

Mason, Angela J.; Tanner, John A.; Johnson, Arthur R.

1997-01-01

Stair-step loading, cyclic loading, and long-term relaxation tests were performed on an aircraft tire to observe the quasi-static viscoelastic response of the tire. The data indicate that the tire continues to respond viscoelastically even after it has been softened by deformation. Load relaxation data from the stair-step test at the 15,000-lb loading was fit to a monotonically decreasing Prony series.

Commentary: legal minimum tread depth for passenger car tires in the U.S.A.--a survey.

PubMed

Blythe, William; Seguin, Debra E

2006-06-01

Available tire traction is a significant highway safety issue, particularly on wet roads. Tire-roadway friction on dry, clean roads is essentially independent of tread depth, and depends primarily on roadway surface texture. However, tire-wet-roadway friction, both for longitudinal braking and lateral cornering forces, depends on several variables, most importantly on water depth, speed and tire tread depth, and the roadway surface texture. The car owner-operator has control over speed and tire condition, but not on water depth or road surface texture. Minimum tire tread depth is legislated throughout most of the United States and Europe. Speed reduction for wet road conditions is not.A survey of state requirements for legal minimum tread depth for passenger vehicle tires in the United States is presented. Most states require a minimum of 2/32 of an inch (approximately 1.6 mm) of tread, but two require less, some have no requirements, and some defer to the federal criterion for commercial vehicle safety inspections. The requirement of 2/32 of an inch is consistent with the height of the tread-wear bars built in to passenger car tires sold in the United States, but the rationale for that requirement, or other existing requirements, is not clear. Recent research indicates that a minimum tread depth of 2/32 of an inch does not prevent significant loss of friction at highway speeds, even for minimally wet roadways. The research suggests that tires with less than 4/32 of an inch tread depth may lose approximately 50 percent of available friction in those circumstances, even before hydroplaning occurs. It is concluded that the present requirements for minimum passenger car tire tread depth are not based upon rational safety considerations, and that an increase in the minimum tread depth requirements would have a beneficial effect on highway safety.

Artist: Rick Guidice Space Colonization - Bernal Sphere - The residential area is in the central

NASA Technical Reports Server (NTRS)

1976-01-01

Artist: Rick Guidice Space Colonization - Bernal Sphere - The residential area is in the central sphere. Farming regions are in the 'tires.' Mirrors reflect sunlight into the habitat and farms. The large flat panels radiate away extra heat into space, and panels of solar cells provide electricity. Factories and docks for spaceships are at either end of the long central tube. (NOTE: art printed in Book 'Space Colony - Frontier of the 21st Century by Franklyn M. Branley)

A is for aphorism--'medicine is my lawful wife, and literature is my mistress. When I get [fed up with] one, I spend the night with the other.'.

PubMed

Koh, Chee

2013-09-01

'I feel more confident and more satisfied with myself when I reflect that I have two professions and not one. Medicine is my lawful wife, and literature is my mistress. When I get tired of one I spend the night with the other. Though it is irregular, it is less boring this way, and besides, neither of them loses anything through my infidelity.'

Thin-film hermeticity - A quantitative analysis of diamondlike carbon using variable angle spectroscopic ellipsometry

NASA Technical Reports Server (NTRS)

Orzeszko, S.; De, Bhola N.; Woollam, John A.; Pouch, John J.; Alterovitz, Samuel A.

1988-01-01

This paper reports on the successful application of variable-angle spectroscopic ellipsometry to quantitative thin-film hermeticity evaluation. It is shown that, under a variety of film preparations and moisture introduction conditions, water penetrates only a very thin diamondlike carbon (DLC) top surface-roughness region. Thus, DLC is an excellent candidate for use as protective coatings in adverse chemical and aqueous environments.

PMMA and polystyrene films modification under ion implantation studied by spectroscopic ellipsometry

NASA Astrophysics Data System (ADS)

Leontyev, A. V.; Kovalev, V. I.; Khomich, A. V.; Komarov, Fadei F.; Grigoryev, V. V.; Kamishan, A. S.

2004-05-01

We have applied spectroscopic ellipsometry with binary polarization modulation to study the refractive index n(λ) and extinction coefficient k(λ) spectra of as-deposited and irradiated with nitrogen ions polymethylmethacrylate (PMMA) and polystyrene (PS) films in 300-1030 nm range. The results of performed investigation confirmed the possibility and estimate restrictions of the ion implantation for local change the refractive index of polymeric materials.

Interaction of In-wheel permanent magnet synchronous motor with tire dynamics

NASA Astrophysics Data System (ADS)

Song, Ziyou; Li, Jianqiu; Wei, Yintao; Xu, Liangfei; Ouyang, Minggao

2015-05-01

Drive wheel systems combined with the in-wheel permanent magnet synchronous motor (I-PMSM) and the tire are highly electromechanical-coupled. However, the deformation dynamics of this system, which may influence the system performance, is neglected in most existing literatures. For this reason, a deformable tire and a detailed I-PMSM are modeled using Matlab/Simulink. Furthermore, the influence of tire/road contact interface is accurately described by the non-linear relaxation length-based model and magic formula pragmatic model. The drive wheel model used in this paper is closer to that of a real tire in contrast to the rigid tire model which is widely used. Based on the near-precise model mentioned above, the sensitivity of the dynamic tire and I-PMSM parameters to the relative error of slip ratio estimation is analyzed. Additionally, the torsional and longitudinal vibrations of the drive wheel are presented both in time and frequency domains when a quarter vehicle is started under conditions of a specific torque curve, which includes an abrupt torque change from 30 N · m to 200 N · m. The parameters sensitivity on drive wheel vibrations is also studied, and the parameters include the mass distribution ratio of tire, the tire torsional stiffness, the tire damping coefficient, and the hysteresis band of the PMSM current control algorithm. Finally, different target torque curves are compared in the simulation, which shows that the estimation error of the slip ratio gets violent, and the longitudinal force includes more fluctuation components with the increasing change rate of the torque. This paper analyzes the influence of the drive wheel deformation on the vehicle dynamic control, and provides useful information regarding the electric vehicle traction control.

In-situ ellipsometry: applications to thin film research, development, and production

NASA Astrophysics Data System (ADS)

Kief, Mark T.

1999-07-01

Many industries including the optics industry, semiconductor industry, and magnetic storage industry are deeply rooted in the science and technology of the film materials and thin film based devices. Research in novel thin film systems and the engineering of artificial structures increasingly requires a control on the atomic scale in both thickness and lateral order. Development of the deposition and fabrication processes for these thin film structures requires technical sophistication and efficiency combined with an understanding of the multi-faceted process interactions. The production of these materials necessitates a remarkable degree of control to minimize scrap and assure good performance. Furthermore, in today's industry these operations must occur at an ever accelerating pace. In this article, we will review one technique which can make these challenges more tractable-- insitu ellipsometry. This is a very powerful tool which is capable of characterizing thin film processes in real-time. We review the art and illustrate with novel applications to metal thin film growth. In addition, we will illustrate how information obtained with insitu ellipsometry can predict the end use thin film properties such as the transport properties. In conclusion, further advances in insitu ellipsometry and its applications will be discussed in terms of needs and trends as a tool for thin film research, development and production.

In-situ ellipsometry: applications to thin film research, development, and production

NASA Astrophysics Data System (ADS)

Kief, M. T.

1999-07-01

Many industries including the optics industry, semiconductor industry, and magnetic storage industry are deeply rooted in the science and technology of thin film materials and thin film based devices. Research in novel thin film systems and the engineering of artificial structures increasingly requires a control on the atomic scale in both thickness and lateral order. Development of the deposition and fabrication processes for these thin film structures requires technical sophistication and efficiency combined with an understanding of the multi-faceted process interactions. The production of these materials necessitates a remarkable degree of control to minimize scrap and assure good performance. Furthermore, in today's industry these operations must occur at an ever accelerating pace. In this article, we will review one technique which can make these challenges more tractable - insitu ellipsometry. This is a very powerful tool which is capable of characterizing thin film processes in real-time. We review the art and illustrate with novel applications to metal thin film growth. In addition, we will illustrate how information obtained with insitu ellipsometry can predict the end use thin film properties such as the transport properties. In conclusion, further advances in insitu ellipsometry and its applications will be discussed in terms of needs and trends as a tool for thin film research, development and production.

Holographic Techniques for Nondestructive Testing of Tires

DOT National Transportation Integrated Search

1972-04-01

Holographic interferometric techniques were used in a development program to evaluate the feasibility of the technique in the nondestructive testing (NDT) of commercial automobile tires. Passenger tires with built-in defects were holographically insp...

Tire pressure special study : methodology

DOT National Transportation Integrated Search

2001-08-01

Tire Pressure Special Study: Methodology is the : first in a series of research notes pertaining to the : Tire Pressure Special Study (TPSS) conducted by : the National Highway Traffic Safety Administration : (NHTSA). Upcoming research notes wi...

Application of tire dynamics to aircraft landing gear design analysis

NASA Technical Reports Server (NTRS)

Black, R. J.

1983-01-01

The tire plays a key part in many analyses used for design of aircraft landing gear. Examples include structural design of wheels, landing gear shimmy, brake whirl, chatter and squeal, complex combination of chatter and shimmy on main landing gear (MLG) systems, anti-skid performance, gear walk, and rough terrain loads and performance. Tire parameters needed in the various analyses are discussed. Two tire models are discussed for shimmy analysis, the modified Moreland approach and the von Schlippe-Dietrich approach. It is shown that the Moreland model can be derived from the Von Schlippe-Dietrich model by certain approximations. The remaining analysis areas are discussed in general terms and the tire parameters needed for each are identified. Accurate tire data allows more accurate design analysis and the correct prediction of dynamic performance of aircraft landing gear.

49 CFR 571.119 - Standard No. 119; New pneumatic tires for motor vehicles with a GVWR of more than 4,536 kilograms...

Code of Federal Regulations, 2013 CFR

2013-10-01

... tubetype tires, and (c) undergoes no permanent rim deformation and allows no loss of air through the..., tube valve and flap assembly (as required) that allows no loss of air for testing of tube-type tires... 49 Transportation 6 2013-10-01 2013-10-01 false Standard No. 119; New pneumatic tires for motor...

49 CFR 571.119 - Standard No. 119; New pneumatic tires for motor vehicles with a GVWR of more than 4,536 kilograms...

Code of Federal Regulations, 2011 CFR

2011-10-01

... tubetype tires, and (c) undergoes no permanent rim deformation and allows no loss of air through the..., tube valve and flap assembly (as required) that allows no loss of air for testing of tube-type tires... 49 Transportation 6 2011-10-01 2011-10-01 false Standard No. 119; New pneumatic tires for motor...

49 CFR 571.119 - Standard No. 119; New pneumatic tires for motor vehicles with a GVWR of more than 4,536 kilograms...

Code of Federal Regulations, 2010 CFR

2010-10-01

... tubetype tires, and (c) undergoes no permanent rim deformation and allows no loss of air through the..., tube valve and flap assembly (as required) that allows no loss of air for testing of tube-type tires... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 119; New pneumatic tires for motor...

49 CFR 571.119 - Standard No. 119; New pneumatic tires for motor vehicles with a GVWR of more than 4,536 kilograms...

Code of Federal Regulations, 2014 CFR

2014-10-01

... tubetype tires, and (c) undergoes no permanent rim deformation and allows no loss of air through the..., tube valve and flap assembly (as required) that allows no loss of air for testing of tube-type tires... 49 Transportation 6 2014-10-01 2014-10-01 false Standard No. 119; New pneumatic tires for motor...

49 CFR 571.119 - Standard No. 119; New pneumatic tires for motor vehicles with a GVWR of more than 4,536 kilograms...

Code of Federal Regulations, 2012 CFR

2012-10-01

... tubetype tires, and (c) undergoes no permanent rim deformation and allows no loss of air through the..., tube valve and flap assembly (as required) that allows no loss of air for testing of tube-type tires... 49 Transportation 6 2012-10-01 2012-10-01 false Standard No. 119; New pneumatic tires for motor...

26 x 6.6 radial-belted aircraft tire performance

NASA Technical Reports Server (NTRS)

Davis, Pamela A.; Martinson, Veloria J.; Yager, Thomas J.; Stubbs, Sandy M.

1991-01-01

Preliminary results from testing of 26 x 6.6 radial-belted and bias-ply aircraft tires at NASA Langley's Aircraft Landing Dynamics Facility (ALDF) are reviewed. The 26 x 6.6 tire size evaluation includes cornering performance tests throughout the aircraft ground operational speed range for both dry and wet runway surfaces. Static test results to define 26 x 6.6 tire vertical stiffness properties are also presented and discussed.

Yawed-Rolling Tire Mechanical Properties Testing of the Navy T-45 Aircraft Tires

NASA Technical Reports Server (NTRS)

Daugherty, Robert H.

2000-01-01

The T-45 Goshawk is a United States Navy Jet aircraft used primarily as a trainer. The aircraft design makes use of "off the shelf" hardware as much as possible and was found to have unusual directional control issues during around operations. The aircraft was involved in numerous pilot-induced-oscillation incidents as well as observed to have unusual directional control reactions to failed main gear tires, a condition that is normally handled relatively easily by conventional aircraft steering control techniques. The behavior of the aircraft's tires had previously been modeled in simulators as a result of approximations provided in 40-year-old reference publications. Since knowledge of the true tire cornering and braking behavior is essential to modeling, understanding, and fixing directional control problems, the United States Navy requested assistance from the NASA Langley Research Center's (LARC) Aircraft Landing Dynamics Facility (ALDF) to define the yawed-rolling mechanical properties of the T-45 aircraft tires. The purpose of this report is to document the results of testing the subject tires at the NASA LaRC ALDF in September 1998. Brief descriptions of the Instrumented Tire Test Vehicle (ITTV) are included to familiarize the reader with the ITTV capabilities, data acquisition system, test and measurement techniques, data accuracy, and analysis and presentation of the testing results.

Three Three-Axis IEPE Accelerometers on the Inner Liner of a Tire for Finding the Tire-Road Friction Potential Indicators.

PubMed

Niskanen, Arto; Tuononen, Ari J

2015-08-05

Direct tire-road contact friction estimation is essential for future autonomous cars and active safety systems. Friction estimation methods have been proposed earlier for driving conditions in the presence of a slip angle or slip ratio. However, the estimation of the friction from a freely-rolling tire is still an unsolved topic. Knowing the existing friction potential would be beneficial since vehicle control systems could be adjusted before any remarkable tire force has been produced. Since accelerometers are well-known and robust, and thus a promising sensor type for intelligent tires, this study uses three three-axis IEPE accelerometers on the inner liner of a tire to detect friction potential indicators on two equally smooth surfaces with different friction levels. The equal roughness was chosen for both surfaces in order to study the friction phenomena by neglecting the effect of surface texture on vibrations. The acceleration data before the contact is used to differentiate the two friction levels between the tire and the road. In addition, the contact lengths from the three accelerometers are used to validate the acceleration data. A method to differentiate the friction levels on the basis of the acceleration signal is also introduced.

The NASA landing gear test airplane

NASA Technical Reports Server (NTRS)

Carter, John F.; Nagy, Christopher J.

1995-01-01

A tire and landing gear test facility has been developed and incorporated into a Convair 990 aircraft. The system can simulate tire vertical load profiles to 250,000 lb, sideslip angles to 15 degrees, and wheel braking on actual runways. Onboard computers control the preprogrammed test profiles through a feedback loop and also record three axis loads, tire slip angle, and tire condition. The aircraft to date has provided tire force and wear data for the Shuttle Orbiter tire on three different runways and at east and west coast landing sites. This report discusses the role of this facility in complementing existing ground tire and landing gear test facilities, and how this facility can simultaneously simulate the vertical load, tire slip, velocity, and surface for an entire aircraft landing. A description is given of the aircraft as well as the test system. An example of a typical test sequence is presented. Data collection and reduction from this facility are discussed, as well as accuracies of calculated parameters. Validation of the facility through ground and flight tests is presented. Tests to date have shown that this facility can operate at remote sites and gather complete data sets of load, slip, and velocity on actual runway surfaces. The ground and flight tests have led to a successful validation of this test facility.

Three Three-Axis IEPE Accelerometers on the Inner Liner of a Tire for Finding the Tire-Road Friction Potential Indicators †

PubMed Central

Niskanen, Arto; Tuononen, Ari J.

2015-01-01

Direct tire-road contact friction estimation is essential for future autonomous cars and active safety systems. Friction estimation methods have been proposed earlier for driving conditions in the presence of a slip angle or slip ratio. However, the estimation of the friction from a freely-rolling tire is still an unsolved topic. Knowing the existing friction potential would be beneficial since vehicle control systems could be adjusted before any remarkable tire force has been produced. Since accelerometers are well-known and robust, and thus a promising sensor type for intelligent tires, this study uses three three-axis IEPE accelerometers on the inner liner of a tire to detect friction potential indicators on two equally smooth surfaces with different friction levels. The equal roughness was chosen for both surfaces in order to study the friction phenomena by neglecting the effect of surface texture on vibrations. The acceleration data before the contact is used to differentiate the two friction levels between the tire and the road. In addition, the contact lengths from the three accelerometers are used to validate the acceleration data. A method to differentiate the friction levels on the basis of the acceleration signal is also introduced. PMID:26251914

The space shuttle program from challenge to achievement: Space exploration rolling on tires

NASA Technical Reports Server (NTRS)

Felder, G. L.

1985-01-01

The Space Shuttle Transportation System is the first space program to employ the pneumatic tire as a part of space exploration. For aircraft tires, this program establishes new expectations as to what constitutes acceptable performance within a set of tough environmental and operational conditions. Tire design, stresses the usual low weight, high load, high speed, and excellent air retention features but at extremes well outside industry standards. Tires will continue to be an integral part of the Shuttle's landing phase in the immediate future since they afford a unique combination of directional control, braking traction, flotation and shock absorption not available by other systems.

Heat generation in aircraft tires

NASA Technical Reports Server (NTRS)

Clark, S. K.; Dodge, R. N.

1985-01-01

A method was developed for calculating the internal temperature distribution in an aircraft tire while free rolling under load. The method uses an approximate stress analysis of each point in the tire as it rolls through the contact patch, and from this stress change the mechanical work done on each volume element may be obtained and converted into a heat release rate through a knowledge of material characteristics. The tire cross-section is then considered as a body with internal heat generation, and the diffusion equation is solved numerically with appropriate boundary conditions of the wheel and runway surface. Comparison with data obtained with buried thermocouples in tires shows good agreement.

Vein-style air pumping tube and tire system and method of assembly

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

Benedict, Robert Leon; Gobinath, Thulasiram; Lin, Cheng-Hsiung

An air pumping tube and tire system and method of assembling is provided in which a tire groove is formed to extend into a flexing region of a tire sidewall and a complementary air pumping tube inserts into the tire groove. In the green, uncured air pumping tube condition, one or more check valves are assembled into the air pumping tube through access shafts and align with an internal air passageway of the air pumping tube. Plug components of the system enclose the check valves in the air pumping tube and the check valve-containing green air pumping tube is thenmore » cured.« less

Heat generation in aircraft tires

NASA Technical Reports Server (NTRS)

Clark, S. K.

1983-01-01

A method was developed for calculating the internal temperature distribution in an aircraft tire while free rolling under load. The method uses an approximate stress analysis of each point in the tire as it rolls through the contact patch, and from this stress change the mechanical work done on each volume element may be obtained and converted into a heat release rate through a knowledge of material characteristics. The tire cross-section is then considered as a body with internal heat generation, and the diffusion equation is solved numerically with appropriate boundary conditions of the wheel and runway surface. Comparison with data obtained with buried thermocouples in tires shows good agreement.

An evaluation of string theory for the prediction of dynamic tire properties using scale model aircraft tires

NASA Technical Reports Server (NTRS)

Clark, S. K.; Dodge, R. N.; Nybakken, G. H.

1972-01-01

The string theory was evaluated for predicting lateral tire dynamic properties as obtained from scaled model tests. The experimental data and string theory predictions are in generally good agreement using lateral stiffness and relaxation length values obtained from the static or slowly rolling tire. The results indicate that lateral forces and self-aligning torques are linearly proportional to tire lateral stiffness and to the amplitude of either steer or lateral displacement. In addition, the results show that the ratio of input excitation frequency to road speed is the proper independent variable by which frequency should be measured.

NASA evaluation of Type 2 chemical depositions. [effects of deicer deposition on aircraft tire friction performance

NASA Technical Reports Server (NTRS)

Yager, Thomas J.; Stubbs, Sandy M.; Howell, W. Edward; Webb, Granville L.

1993-01-01

Recent findings from NASA Langley tests to define effects of aircraft Type 2 chemical deicer depositions on aircraft tire friction performance are summarized. The Aircraft Landing Dynamics Facility (ALDF) is described together with the scope of the tire cornering and braking friction tests conducted up to 160 knots ground speed. Some lower speed 32 - 96 km/hr (20 - 60 mph) test run data obtained using an Instrumented Tire Test Vehicle (ITTV) to determine effects of tire bearing pressure and transverse grooving on cornering friction performance are also discussed. Recommendations are made concerning which parameters should be evaluated in future testing.

Deformability of shredded tires

DOT National Transportation Integrated Search

1999-01-01

This report describes three separate studies that examine the deformability of shredded tire fill material. The first study determined the response of shredded tires to cyclic loading. These tests were conducted in a load frame on both constrained an...

40 CFR 63.5982 - What parts of my facility does this subpart cover?

Code of Federal Regulations, 2010 CFR

2010-07-01

...; bead cementing operations; tire building operations; green tire spray operations; extruding, to the... operations; other tire building operations, to the extent that cements and solvents are used; and balance pad...

26 CFR 48.4073-1 - Exemption of tires of certain sizes.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) MISCELLANEOUS EXCISE TAXES MANUFACTURERS AND RETAILERS EXCISE TAXES Motor Vehicles, Tires, Tubes, Tread Rubber... tax does not apply to sales of tires of all-rubber construction (whether hollow center or solid) if...

26 CFR 48.4073-1 - Exemption of tires of certain sizes.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) MISCELLANEOUS EXCISE TAXES MANUFACTURERS AND RETAILERS EXCISE TAXES Motor Vehicles, Tires, Tubes, Tread Rubber... tax does not apply to sales of tires of all-rubber construction (whether hollow center or solid) if...

26 CFR 48.4073-1 - Exemption of tires of certain sizes.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) MISCELLANEOUS EXCISE TAXES MANUFACTURERS AND RETAILERS EXCISE TAXES Motor Vehicles, Tires, Tubes, Tread Rubber... tax does not apply to sales of tires of all-rubber construction (whether hollow center or solid) if...

26 CFR 48.4073-1 - Exemption of tires of certain sizes.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) MISCELLANEOUS EXCISE TAXES MANUFACTURERS AND RETAILERS EXCISE TAXES Motor Vehicles, Tires, Tubes, Tread Rubber... tax does not apply to sales of tires of all-rubber construction (whether hollow center or solid) if...

Statistical analysis of tire treadwear data

DOT National Transportation Integrated Search

1985-03-01

This report describes the results of a statistical analysis of the treadwear : variability of radial tires subjected to the Uniform Tire Quality Grading (UTQG) : standard. Because unexplained variability in the treadwear portion of the standard : cou...

Mechanistic understanding of tetracycline sorption on waste tire powder and its chars as affected by Cu(2+) and pH.

PubMed

Lian, Fei; Song, Zhengguo; Liu, Zhongqi; Zhu, Lingyan; Xing, Baoshan

2013-07-01

The sorption characteristics of tetracycline (TC) by waste tire powder and its chars were investigated to explore the potential of using waste tires as effective sorbents for removal of TC from aqueous solution. Naphthalene (NAPH), a typical hydrophobic organic compound, was selected as asorbate for comparison. TC displayed much lower sorption affinity to tire powder than NAPH. However, it exhibited similar adsorption affinity as NAPH on the pyrolyzed tire chars, which was mainly attributed to π-π electron-donor-acceptor interactions of TC with the graphite surface of chars. TC and Cu(2+) could mutually facilitate the sorption of each other on both tire powder and pyrolyzed chars in a wide pH range. This could be explained by the metallic complexation and/or surface-bridging mechanisms (i.e., Cu- or TC-bridging). However, Cu(2+) and NAPH depressed the sorption of each other on tire powder and displayed negligible impact to each other on the highly pyrolyzed chars. Copyright © 2013 Elsevier Ltd. All rights reserved.

Tire-rim interface pressure of a commercial vehicle wheel under radial loads: theory and experiment

NASA Astrophysics Data System (ADS)

Wan, Xiaofei; Shan, Yingchun; Liu, Xiandong; He, Tian; Wang, Jiegong

2017-11-01

The simulation of the radial fatigue test of a wheel has been a necessary tool to improve the design of the wheel and calculate its fatigue life. The simulation model, including the strong nonlinearity of the tire structure and material, may produce accurate results, but often leads to a divergence in calculation. Thus, a simplified simulation model in which the complicated tire model is replaced with a tire-wheel contact pressure model is used extensively in the industry. In this paper, a simplified tire-rim interface pressure model of a wheel under a radial load is established, and the pressure of the wheel under different radial loads is tested. The tire-rim contact behavior affected by the radial load is studied and analyzed according to the test result, and the tire-rim interface pressure extracted from the test result is used to evaluate the simplified pressure model and the traditional cosine function model. The results show that the proposed model may provide a more accurate prediction of the wheel radial fatigue life than the traditional cosine function model.

Co-gasification of tire and biomass for enhancement of tire-char reactivity in CO2 gasification process.

PubMed

Lahijani, Pooya; Zainal, Zainal Alimuddin; Mohamed, Abdul Rahman; Mohammadi, Maedeh

2013-06-01

In this investigation, palm empty fruit bunch (EFB) and almond shell (AS) were implemented as two natural catalysts rich in alkali metals, especially potassium, to enhance the reactivity of tire-char through co-gasification process. Co-gasification experiments were conducted at several blending ratios using isothermal Thermogravimetric analysis (TGA) under CO2. The pronounced effect of inherent alkali content of biomass-chars on promoting the reactivity of tire-char was proven when acid-treated biomass-chars did not exert any catalytic effect on improving the reactivity of tire-char in co-gasification experiments. In kinetic studies of the co-gasified samples in chemically-controlled regime, modified random pore model (M-RPM) was adopted to describe the reactive behavior of the tire-char/biomass-char blends. By virtue of the catalytic effect of biomass, the activation energy for tire-char gasification was lowered from 250 kJ/mol in pure form 203 to 187 kJ/mol for AS-char and EFB-char co-gasified samples, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Spray From a Rolling Tire: Mechanics of Droplet Formation

NASA Astrophysics Data System (ADS)

Plocher, Dennis; Browand, Fred

2010-11-01

The spray pattern immediately behind a single-groove tire rolling on a wet surface is produced in the laboratory using a specially designed tire spray simulator. The spray development is examined using high speed video. Water from the groove forms a liquid sheet as the tire-tread lifts away from the surface. The sheet is not of uniform thickness, but it remains attached to the tread. The thinner portions of the sheet become even thinner as the tire rotates, and eventually break to produce holes near the tire surface. The holes grow as the sheet margins surrounding the holes retract into the thicker portions of the sheet which become roughly cylindrical "ligaments" aligned at right angles to the direction of spray motion. The ligaments break into large droplets via a Rayleigh instability. The smallest droplets form when the margins of two holes collide. As Weber number, We = ρU^2w/2σ , based on tire groove half width, w/2, varies by a factor of 25, the sheet-ligament structure persists, but ligaments become less organized, and more small droplets appear in the pattern.

Nonlinear Analysis and Modeling of Tires

NASA Technical Reports Server (NTRS)

Noor, Ahmed K.

1996-01-01

The objective of the study was to develop efficient modeling techniques and computational strategies for: (1) predicting the nonlinear response of tires subjected to inflation pressure, mechanical and thermal loads; (2) determining the footprint region, and analyzing the tire pavement contact problem, including the effect of friction; and (3) determining the sensitivity of the tire response (displacements, stresses, strain energy, contact pressures and contact area) to variations in the different material and geometric parameters. Two computational strategies were developed. In the first strategy the tire was modeled by using either a two-dimensional shear flexible mixed shell finite elements or a quasi-three-dimensional solid model. The contact conditions were incorporated into the formulation by using a perturbed Lagrangian approach. A number of model reduction techniques were applied to substantially reduce the number of degrees of freedom used in describing the response outside the contact region. The second strategy exploited the axial symmetry of the undeformed tire, and uses cylindrical coordinates in the development of three-dimensional elements for modeling each of the different parts of the tire cross section. Model reduction techniques are also used with this strategy.

AIR EMISSIONS FROM SCRAP TIRE COMBUSTION

EPA Science Inventory

The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

Pressure Effects on Worn Passenger Car Tire Carcasses

DOT National Transportation Integrated Search

1975-02-01

Work is described to examine the value of hydrostatic proof pressure testing in selecting used tire carcasses for retreading. Preliminary experiments on single tire cords indicate that overloads close to rupture do not damage subsequent fatigue life....

Field study of a shredded-tire embankment.

DOT National Transportation Integrated Search

1994-01-01

This report presents interim data from the ongoing field study of an experimental shredded-tire embankment constructed near Williamsburg, Virginia. Approximately 1.7 million tires were used. This constitutes the largest reported use to date of waste ...

Semi-Automated Pulse-Echo Ultrasonic System for Inspecting Tires

DOT National Transportation Integrated Search

1977-07-01

A nondestructive tire-testing system has been developed using the pulse-echo ultrasonic technique, which offers substantial advantages over all other physical nondestructive-testing methods and shows promise of reducing the cost of production-tire in...

Effect of friction on rolling tire-pavement interaction

DOT National Transportation Integrated Search

2010-11-01

In this research, a three-dimensional (3-D) tire-pavement interaction model is developed using FEM to analyze the tire-pavement contact stress distributions at various rolling conditions (free rolling, braking/accelerating, and cornering). In additio...

26 CFR 48.6416(c)-1 - Credit for tax paid on tires or, prior to January 1, 1984, inner tubes.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Credit for tax paid on tires or, prior to... § 48.6416(c)-1 Credit for tax paid on tires or, prior to January 1, 1984, inner tubes. (a) Allowance of... under section 4218 on the use, of a tire or inner tube, and the manufacturer of another article taxable...

Quasi-Static and Dynamic Response Characteristics of F-4 Bias-Ply and Radial-Belted Main Gear Tires

NASA Technical Reports Server (NTRS)

Davis, Pamela A.

1997-01-01

An investigation was conducted at Langley Research Center to determine the quasi-static and dynamic response characteristics of F-4 military fighter 30x11.5-14.5/26PR bias-ply and radial-belted main gear tires. Tire properties were measured by the application of vertical, lateral, and fore-and-aft loads. Mass moment-of-inertia data were also obtained. The results of the study include quasi-static load-deflection curves, free-vibration time-history plots, energy loss associated with hysteresis, stiffness and damping characteristics, footprint geometry, and inertia properties of each type of tire. The difference between bias-ply and radial-belted tire construction is given, as well as the advantages and disadvantages of each tire design. Three simple damping models representing viscous, structural, and Coulomb friction are presented and compared with the experimental data. The conclusions discussed contain a summary of test observations.

Comparative study of engineering properties of two-lime waste tire particle soil and soil with lime/loess ratio of 3:7

NASA Astrophysics Data System (ADS)

Tiecheng, Yan; Xingyuan, Zhang; Hongping, Yang

2018-03-01

This study describes an analytical comparison of the engineering characteristics of two-lime waste tire particle soil and soil with lime/loess ratio of 3:7 using density measurements, results of indoor consolidation tests, and direct shear tests to examine the strength and deformation characteristics. It investigates the engineering performance of collapsible loess treated with waste tire particles and lime. The results indicate that (1) the shear strength of the two-lime waste tire particle soils increases continuously with soil age; and (2) the two-lime waste tire particle soils are light-weight, strong, and low-deformation soils, and can be applied primarily to improve the foundation soil conditions in areas with collapsible loess soils. This could address the problem of used tire disposal, while providing a new method to consider and manage collapsible loess soils.

Properties and potential environmental applications of carbon adsorbents from waste tire rubber

USGS Publications Warehouse

Lehmann, C.M.B.; Rameriz, D.; Rood, M.J.; Rostam-Abadi, M.

2000-01-01

The properties of tire-derived carbon adsorbents (TDCA) produced from select tire chars were compared with those derived from an Illinois coal and pistachio nut shells. Chemical analyses of the TDCA indicated that these materials contain metallic elements not present in coal-and nut shell-derived carbons. These metals, introduced during the production of tire rubber, potentially catalyze steam gasification reactions of tire char. TDCA carbons contained larger meso-and macopore volumes than their counterparts derived from coal and nut shell (on the moisture-and ash-free-basis). Adsorptive properties of the tire-derived adsorbent carbons for air separation, gas storage, and gas clean up were also evaluated and compared with those of the coal-and nut shell derived carbons as well as a commercial activated carbon. The results revealed that TDCA carbons are suitable adsorbents for removing vapor-phase mercury from combustion flue gases and hazardous organic compounds from industrial gas streams.

Dynamic tire pressure sensor for measuring ground vibration.

PubMed

Wang, Qi; McDaniel, James Gregory; Wang, Ming L

2012-11-07

This work presents a convenient and non-contact acoustic sensing approach for measuring ground vibration. This approach, which uses an instantaneous dynamic tire pressure sensor (DTPS), possesses the capability to replace the accelerometer or directional microphone currently being used for inspecting pavement conditions. By measuring dynamic pressure changes inside the tire, ground vibration can be amplified and isolated from environmental noise. In this work, verifications of the DTPS concept of sensing inside the tire have been carried out. In addition, comparisons between a DTPS, ground-mounted accelerometer, and directional microphone are made. A data analysis algorithm has been developed and optimized to reconstruct ground acceleration from DTPS data. Numerical and experimental studies of this DTPS reveal a strong potential for measuring ground vibration caused by a moving vehicle. A calibration of transfer function between dynamic tire pressure change and ground acceleration may be needed for different tire system or for more accurate application.

Cornering and wear characteristics of the Space Shuttle Orbiter nose-gear tire

NASA Technical Reports Server (NTRS)

Davis, Pamela A.; Stubbs, Sandy M.; Vogler, William A.

1989-01-01

Tests of the Space Shuttle Orbiter nose-gear tire have been completed at NASA Langley's Aircraft Landing Dynamics Facility. The purpose of these tests was to determine the cornering and wear characteristics of the Space Shuttle Orbiter nose-gear tire under realistic operating conditions. The tire was tested on a simulated Kennedy Space Center runway surface at speeds from 100 to 180 kts. The results of these tests defined the cornering characteristics which included side forces and associated side force friction coefficient over a range of yaw angles from 0 deg to 12 deg. Wear characteristics were defined by tire tread and cord wear over a yaw angle range of 0 deg to 4 deg under dry and wet runway conditions. Wear characteristics were also defined for a 15 kt crosswind landing with two blown right main-gear tires and nose-gear steering engaged.

Cornering and wear behavior of the Space Shuttle Orbiter main gear tire

NASA Technical Reports Server (NTRS)

Daugherty, Robert H.; Stubbs, Sandy M.

1987-01-01

One of the factors needed to describe the handling characteristics of the Space Shuttle Orbiter during the landing rollout is the response of the vehicle's tires to variations in load and yaw angle. An experimental investigation of the cornering characteristics of the Orbiter main gear tires was conducted at the NASA Langley Research Center Aircraft Landing Dynamics Facility. This investigation compliments earlier work done to define the Orbiter nose tire cornering characteristics. In the investigation, the effects of load and yaw angle were evaluated by measuring parameters such as side load and drag load, and obtaining measurements of aligning torque. Because the tire must operate on an extremely rough runway at the Shuttle Landing Facility at Kennedy Space Center (KSC), tests were also conducted to describe the wear behavior of the tire under various conditions on a simulated KSC runway surface. Mathematical models for both the cornering and the wear behavior are discussed.

Cornering characteristics of a 40 by 14-16 type 7 aircraft tire and a comparison with characteristics of a C40 by 14-21 cantilever aircraft tire

NASA Technical Reports Server (NTRS)

Tanner, J. A.; Dreher, R. C.

1973-01-01

An investigation was conducted at the Langley aircraft landing loads and traction facility to determine the cornering characteristics of a 40 x 14-16 type VII aircraft tire. These characteristics, which include the cornering-force and drag-force friction coefficients and self-alining torque, were obtained for the tire operating on dry, damp and flooded runway surfaces over a range of yaw angles from 0 deg to 20 deg and at ground speeds from 5 to 100 knots, both with and without braking. The results of this investigation indicated that the cornering capability of the 40 x 14-16 type VII aircraft tire is degraded by high ground speeds, thin-film lubrication and tire hydroplaning effects on the wet surfaces, and brake torque. The cornering capability is greatly diminished when locked-wheel skids are encountered.

Properties of concrete containing scrap-tire rubber--an overview.

PubMed

Siddique, Rafat; Naik, Tarun R

2004-01-01

Solid waste management is one of the major environmental concerns in the United States. Over 5 billion tons of non-hazardous solid waste materials are generated in USA each year. Of these, more than 270 million scrap-tires (approximately 3.6 million tons) are generated each year. In addition to this, about 300 million scrap-tires have been stockpiled. Several studies have been carried out to reuse scrap-tires in a variety of rubber and plastic products, incineration for production of electricity, or as fuel for cement kilns, as well as in asphalt concrete. Studies show that workable rubberized concrete mixtures can be made with scrap-tire rubber. This paper presents an overview of some of the research published regarding the use of scrap-tires in portland cement concrete. The benefits of using magnesium oxychloride cement as a binder for rubberized concrete mixtures are also presented. The paper details the likely uses of rubberized concrete.

Preliminary measurements on heat balance in pneumatic tires

NASA Technical Reports Server (NTRS)

Nybakken, G. H.; Collart, D. Y.; Staples, R. J.; Lackey, J. I.; Clark, S. K.; Dodge, R. N.

1973-01-01

A variety of tests was undertaken to determine the nature of heat generation associated with a pneumatic tire operating under various conditions. Tests were conducted to determine the magnitude and distribution of internally generated heat caused by hysteresis in the rubber and ply fabric in an automobile tire operating under conditions of load, pressure, and velocity representative of normal operating conditions. These included tests at various yaw angles and tests with braking applied. In other tests, temperature sensors were mounted on a road to measure the effect of a tire rolling over and an attempt was made to deduce the magnitude and nature of interfacial friction from the resulting information. In addition, tests were performed using the scratch plate technique to determine the nature of the motion between the tire and road. Finally, a model tire was tested on a roadwheel, the surface covering which could be changed, and an optical pyrometer was used to measure rubber surface temperatures.

Theoretical and experimental analysis of the contact between a solid-rubber tire and a chassis dynamometer

NASA Astrophysics Data System (ADS)

Belkin, A. E.; Semenov, V. K.

2016-05-01

We consider the problem of modeling the test where a solid-rubber tire runs on a chassis dynamometer for determining the tire rolling resistance characteristics.We state the problem of free steady-state rolling of the tire along the test drum with the energy scattering in the rubber in the course of cyclic deformation taken into account. The viscoelastic behavior of the rubber is described by the Bergströ m-Boyce model whose numerical parameters are experimentally determined from the results of compression tests with specimens. The finite element method is used to obtain the solution of the three-dimensional viscoelasticity problem. To estimate the adequacy of the constructed model, we compare the numerical results with the results obtained in the solid-rubber tire tests on the Hasbach stand from the values of the rolling resistance forces for various loads on the tire.

Traction Characteristics of a 30 by 11.5-14.5, Type 8, Aircraft Tire on Dry, Wet and Flooded Surfaces

NASA Technical Reports Server (NTRS)

Yager, T. J.; Dreher, R. C.

1976-01-01

A limited test program was conducted to extend and supplement the braking and cornering data on a 30 x 11.5-14.5, type VIII, aircraft tire to refine the tire/runway friction model for use in the development of an aircraft ground performance simulation. Tire traction data were obtained on dry, wet and flooded runway surfaces at ground speeds ranging from 5 to 100 knots and at yaw angles extending up to 12 deg. These friction coefficients are presented as a function of slip characteristics, namely, the maximum and skidding drag coefficients and the maximum cornering coefficients are presented as a function of both ground speed and yaw angle to extend existing data on that tire size. Tire braking and cornering capabilities were shown to be affected by vehicle ground speed, wheel yaw attitude and the extent of surface wetness.

Experimental investigation of the braking and cornering characteristics of 30 x 11.5-14.5, type 8, aircraft tires with different tread patterns

NASA Technical Reports Server (NTRS)

Dreher, R. C.; Tanner, J. A.

1974-01-01

An investigation was conducted at the aircraft landing loads and traction facility to study the braking and cornering characteristics, including the drag-force and cornering-force friction coefficients, of 30 by 11.5-14.5, type VIII aircraft tires with five different tread patterns. Test data were obtained on dry, damp, and flooded runway surfaces over a range of yaw angles from 0 deg to 12 deg at ground speeds from 5 knots to 100 knots. The results of this investigation indicate that a tread pattern consisting of transverse cuts across the entire width of the tread slightly improved the tire traction performance on wet surfaces. The braking and cornering capability of the tires was degraded by thin-film lubrication and tire hydroplaning effects on the wet runway surfaces. The braking capability of the tires decreased when the yaw angle was increased.

Dynamics and Stability of Rolling Viscoelastic Tires

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

Potter, Trevor

2013-04-30

Current steady state rolling tire calculations often do not include treads because treads destroy the rotational symmetry of the tire. We describe two methodologies to compute time periodic solutions of a two-dimensional viscoelastic tire with treads: solving a minimization problem and solving a system of equations. We also expand on work by Oden and Lin on free spinning rolling elastic tires in which they disovered a hierachy of N-peak steady state standing wave solutions. In addition to discovering a two-dimensional hierarchy of standing wave solutions that includes their N-peak hiearchy, we consider the eects of viscoelasticity on the standing wavemore » solutions. Finally, a commonplace model of viscoelasticity used in our numerical experiments led to non-physical elastic energy growth for large tire speeds. We show that a viscoelastic model of Govindjee and Reese remedies the problem.« less

Dynamic Tire Pressure Sensor for Measuring Ground Vibration

PubMed Central

Wang, Qi; McDaniel, James Gregory; Wang, Ming L.

2012-01-01

This work presents a convenient and non-contact acoustic sensing approach for measuring ground vibration. This approach, which uses an instantaneous dynamic tire pressure sensor (DTPS), possesses the capability to replace the accelerometer or directional microphone currently being used for inspecting pavement conditions. By measuring dynamic pressure changes inside the tire, ground vibration can be amplified and isolated from environmental noise. In this work, verifications of the DTPS concept of sensing inside the tire have been carried out. In addition, comparisons between a DTPS, ground-mounted accelerometer, and directional microphone are made. A data analysis algorithm has been developed and optimized to reconstruct ground acceleration from DTPS data. Numerical and experimental studies of this DTPS reveal a strong potential for measuring ground vibration caused by a moving vehicle. A calibration of transfer function between dynamic tire pressure change and ground acceleration may be needed for different tire system or for more accurate application. PMID:23202206

The effect of FeF2 on the magneto-optic response in FeF2/Fe/FeF2 sandwiches

NASA Astrophysics Data System (ADS)

Pištora, J.; Lesňák, M.; Lišková, E.; Višňovský, Š.; Harward, I.; Maslankiewicz, P.; Balin, K.; Celinski, Z.; Mistrík, J.; Yamaguchi, T.; Lopusnik, R.; Vlček, J.

2010-04-01

The room temperature optical constants n and k of MBE grown FeF2 films are reported. Because of poor chemical stability, FeF2 had to be coated with a protective Au layer. Reflection spectral ellipsometry in the photon energy range between 1.3 and 5.2 eV was performed on structures with a typical profile Au(0.5 nm)/FeF2(120 nm)/Au(30 nm)/Ag(20 nm)/Fe(0.6 nm) grown on GaAs(0 0 1) substrate. The spectra of n and k in FeF2 were subsequently employed in the design of FeF2/Fe/FeF2 sandwiches considered as magneto-optic (MO) sensors for weak microwave currents. Their MO response was evaluated using reflection MO (Kerr) spectroscopy at polar magnetization. The present results may be of interest in MO studies of magnetic nanostructures with Fe/FeF2/Fe, including MO magnetometry and MO magnetic domain imaging.

B-spline parameterization of the dielectric function and information criteria: the craft of non-overfitting

NASA Astrophysics Data System (ADS)

Likhachev, Dmitriy V.

2017-06-01

Johs and Hale developed the Kramers-Kronig consistent B-spline formulation for the dielectric function modeling in spectroscopic ellipsometry data analysis. In this article we use popular Akaike, corrected Akaike and Bayesian Information Criteria (AIC, AICc and BIC, respectively) to determine an optimal number of knots for B-spline model. These criteria allow finding a compromise between under- and overfitting of experimental data since they penalize for increasing number of knots and select representation which achieves the best fit with minimal number of knots. Proposed approach provides objective and practical guidance, as opposite to empirically driven or "gut feeling" decisions, for selecting the right number of knots for B-spline models in spectroscopic ellipsometry. AIC, AICc and BIC selection criteria work remarkably well as we demonstrated in several real-data applications. This approach formalizes selection of the optimal knot number and may be useful in practical perspective of spectroscopic ellipsometry data analysis.

In situ monitoring of atomic layer epitaxy via optical ellipsometry

NASA Astrophysics Data System (ADS)

Lyzwa, F.; Marsik, P.; Roddatis, V.; Bernhard, C.; Jungbauer, M.; Moshnyaga, V.

2018-03-01

We report on the use of time-resolved optical ellipsometry to monitor the deposition of single atomic layers with subatomic sensitivity. Ruddlesden-Popper thin films of SrO(SrTiO3) n=4 were grown by means of metalorganic aerosol deposition in the atomic layer epitaxy mode on SrTiO3(1 0 0), LSAT(1 0 0) and DyScO3(1 1 0) substrates. The measured time dependences of ellipsometric angles, Δ(t) and Ψ(t), were described by using a simple optical model, considering the sequence of atomic layers SrO and TiO2 with corresponding bulk refractive indices. As a result, valuable online information on the atomic layer epitaxy process was obtained. Ex situ characterization techniques, i.e. transmission electron microscopy, x-ray diffraction and x-ray reflectometry verify the crystal structure and confirm the predictions of optical ellipsometry.

The optical properties of transferred graphene and the dielectrics grown on it obtained by ellipsometry

NASA Astrophysics Data System (ADS)

Kasikov, Aarne; Kahro, Tauno; Matisen, Leonard; Kodu, Margus; Tarre, Aivar; Seemen, Helina; Alles, Harry

2018-04-01

Graphene layers grown by chemical vapour deposition (CVD) method and transferred from Cu-foils to the oxidized Si-substrates were investigated by spectroscopic ellipsometry (SE), Raman and X-Ray Photoelectron Spectroscopy (XPS) methods. The optical properties of transferred CVD graphene layers do not always correspond to the ones of the exfoliated graphene due to the contamination from the chemicals used in the transfer process. However, the real thickness and the mean properties of the transferred CVD graphene layers can be found using ellipsometry if a real thickness of the SiO2 layer is taken into account. The pulsed laser deposition (PLD) and atomic layer deposition (ALD) methods were used to grow dielectric layers on the transferred graphene and the obtained structures were characterized using optical methods. The approach demonstrated in this work could be useful for the characterization of various materials grown on graphene.

Modal analysis of a loaded tire with non-contact measurements and piezoelectric excitation

NASA Astrophysics Data System (ADS)

Ferhat, Ipar; Tarazaga, Pablo A.

2017-04-01

The complex nature of tires requires very precise test data to model the structure accurately. The highly damped characteristics, geometric features and operational conditions of tires cause various testing difficulties that affect the reliability of the modal testing. One of the biggest challenges of tire testing is exciting the whole tire at once. Conventionally, impact hammers, shakers, and cleats are used as an excitation input. The shortcomings of these excitation methods are the directional and force inconsistency of hammer impacts, coupled dynamics of shakers and speed limitations of cleat excitation. Other challenges of modal testing of tires are the effect of added mass due to sensor placements and difficulty of vibration measurement of a rotating tire with accelerometers. In order to remedy these problems, we conduct experimental modal analysis (EMA) using a non-contact measurement technique and piezoelectric excitation. For non-contact measurement, a 3-D scanning laser doppler vibrometer (SLDV) is used. For the piezoelectric excitation, Micro Fiber Composite (MFC) patches are used due to their flexible nature and power capacity. This excitation method can also be crucial to the excitation of rotating tires since the cleat excitation is not adequate for low-speed measurements. Furthermore, the piezoelectric actuation could be used as sensors as well as noise controllers in operating conditions. For this work, we run experiments for a loaded tire in non-rotating condition. Experiments are carried out for the frequency bandwidth up to 500Hz to capture the structural behavior under high-frequency excitations and its potential coupled behavior to airborne noise.

Truck Rollover Characterization for Class-8 Tractor-Trailers Utilizing Standard Dual Tires and New-Generation Single Tires

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

Capps, Gary; Knee, Bill; Franzese, Oscar

2005-07-30

The Heavy Truck Rollover Characterization Project is a major research effort conducted by the National Transportation Research Center, Inc. (NTRCI) in partnership with Oak Ridge National Laboratory (ORNL), Dana Corporation (Dana), Michelin Americas Research and Development Corporation (Michelin) and Clemson University (Clemson), under the NTRCIs Heavy Vehicle Safety Research Center (HVSRC) for the Federal Highway Administration (FHWA). ORNL provided the day-to-day management of the project. The expertise mix of this team coupled with complementary research needs and interests, and a positive can-do attitude provided an extremely positive experimental research opportunity for all involved. Furthermore, this team supplied significant and valuablemore » resources that provided a strong positive benchmark regarding the ability to conduct research within a public-private partnership. The work conducted by this team focused on initial efforts to generate data and information on heavy truck rollover not currently available in the industry. It reflects efforts within Phases 1 and 2 of a longer-term four-phase research program. A 1999 Peterbilt 379 class-8 tractor and 2004 Wabash dry freight van trailer were the test vehicles utilized in this effort. Both were instrumented with a number of sensors to capture the dynamics of the tractor and trailer as it engaged in various testing maneuvers that included: an evasive maneuver, swept sine, constant radius, and a run-off-the-road maneuver. The run-off-the-road maneuver was discontinued because the test track could not safety accommodate such a maneuver. These maneuvers were carried out utilizing both standard dual tires and new-generation dual tires in six test series. Two test series also included the use of a wider-slider suspension. Outriggers were placed on the test vehicle to assure that an actual rollover would not occur, however, the tests were designed to generate lift-off of tires during the tests. One of the main objectives of the tests that are a part of this study was to understand how different elements (e.g., dual tires and wide-base, new-generation single tires, different trailer suspension types, etc.) affect the overall vehicle roll stability. Tilt-table tests were also performed to characterize the static rollover propensity if the tractor trailer. For all of the tests, the vehicle was loaded with ballast for a gross vehicle weight rating of 79,000 lbs., and the speeds were gradually increased so that wheel lift-off was experienced both visually and via instrumentation. A significant amount of data was collected on all maneuvers performed (1.2 Gigabytes of data from 45 data channels sampled at 0.01 sec) and information was also captured via videotaping (one camera inside the cabin and three others outside; plus one off-board camera). Due to a number of issues related to the sensors, and idiosyncrasies in the data itself, a statistically meaningful data set was not possible. However sufficient data was collected to demonstrate the trends and patterns in the heavy truck rollover phenomenon.« less

76 FR 67132 - Foreign-Trade Zone 177-Evansville, IN; Application for Manufacturing Authority; Hoosier Stamping...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-31

... within Site 8 of FTZ 177. The facility is used for the manufacturing, testing, warehousing, packaging...: pneumatic tires, tubes, rolled rim rings, semi-pneumatic tires, herring-bone tires, welding wires and bolts...

Proof Pressure Evaluation of Worn Passenger Car Tire Carcasses

DOT National Transportation Integrated Search

1976-11-01

Test work is described that examines the value of hydrostatic proof pressure testing in screening worn tire carcasses before retreading. Results are given from dynamometer wheel tests on a significant sample of retreaded passenger car tires. Each sam...

49 CFR 579.26 - Reporting requirements for manufacturers of tires.

Code of Federal Regulations, 2010 CFR

2010-10-01

... of tires with the same SKU, plant where manufactured, and year for which the volume produced or imported is less than 15,000, or are deep tread, winter-type snow tires, space-saver or temporary use spare...

49 CFR 579.26 - Reporting requirements for manufacturers of tires.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of tires with the same SKU, plant where manufactured, and year for which the volume produced or imported is less than 15,000, or are deep tread, winter-type snow tires, space-saver or temporary use spare...

Electronic and optical properties of titanium nitride bulk and surfaces from first principles calculations

NASA Astrophysics Data System (ADS)

Mehmood, Faisal; Pachter, Ruth; Murphy, Neil R.; Johnson, Walter E.

2015-11-01

Prediction of the frequency-dependent dielectric function of thin films poses computational challenges, and at the same time experimental characterization by spectroscopic ellipsometry remains difficult to interpret because of changes in stoichiometry and surface morphology, temperature, thickness of the film, or substrate. In this work, we report calculations for titanium nitride (TiN), a promising material for plasmonic applications because of less loss and other practical advantages compared to noble metals. We investigated structural, electronic, and optical properties of stoichiometric bulk TiN, as well as of the TiN(100), TiN(110), and TiN(111) outermost surfaces. Density functional theory (DFT) and many-body GW methods (Green's (G) function-based approximation with screened Coulomb interaction (W)) were used, ranging from G0W0, GW0 to partially self-consistent sc-GW0, as well as the GW-BSE (Bethe-Salpeter equation) and time-dependent DFT (TDDFT) methods for prediction of the optical properties. Structural parameters and the band structure for bulk TiN were shown to be consistent with previous work. Calculated dielectric functions, plasma frequencies, reflectivity, and the electron energy loss spectrum demonstrated consistency with experiment at the GW0-BSE level. Deviations from experimental data are expected due to varying experimental conditions. Comparison of our results to spectroscopic ellipsometry data for realistic nanostructures has shown that although TDDFT may provide a computationally feasible level of theory in evaluation of the dielectric function, application is subject to validation with GW-BSE calculations.

Ellipsometry-like analysis of polarization state for micro cracks using stress-induced light scattering method

NASA Astrophysics Data System (ADS)

Sakata, Yoshitaro; Terasaki, Nao; Sakai, Kazufumi; Nonaka, Kazuhiro

2016-03-01

Fine polishing techniques, such as chemical mechanical polishing (CMP), are important to glass substrate manufacturing. When these techniques involve mechanical interaction in the form of friction between the abrasive and the substrate surface during polishing, latent flaws may form on the product. Fine polishing induced latent flaws in glass substrates may become obvious during a subsequent cleaning process if the glass surface is eroded away by chemical interaction with a cleaning liquid. Thus, latent flaws reduce product yield. A novel technique (the stress-induced light scattering method; SILSM) which was combined with light scattering method and stress effects was proposed for inspecting surface to detect polishing induced latent flaws. This method is able to distinguish between latent flaws and tiny particles on the surface. In this method, an actuator deforms a sample inducing stress effects around the tip of a latent flaw caused by the deformation, which in turn changes the refractive index of the material around the tip of the latent flaw because of the photoelastic effect. A CCD camera detects this changed refractive index as variations in light-scattering intensity. In this study, the changes in reflection coefficients and polarization states after application of stress to a glass substrate were calculated and evaluated qualitatively using Jones matrix-like ellipsometry. As the results, it was shown that change in the polarization states around the tip of latent flaw were evaluated between before and after applied stress, qualitatively.

Heat generation in aircraft tires under free rolling conditions

NASA Technical Reports Server (NTRS)

Clark, S. K.; Dodge, R. N.

1982-01-01

A method was developed for calculating the internal temperature distribution in an aircraft tire while free rolling under load. The method uses an approximate stress analysis of each point in the tire as it rolls through the contact patch, and from this stress change the mechanical work done on each volume element may be obtained and converted into a heat release rate through a knowledge of material characteristics. The tire cross-section is then considered as a body with internal heat generation, and the diffusion equation is solved numerically with appropriate boundary conditions of the wheel and runway surface. Comparison with data obtained with buried thermocouples in tires shows good agreement.

Sustainable Potassium-Ion Battery Anodes Derived from Waste-Tire Rubber

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

Li, Yunchao; Adams, Ryan A.; Arora, Anjela

The recycling of waste-tire rubber is of critical importance since the discarded tires pose serious environmental and health hazards to our society. Here, we report a new application for hard-carbon materials derived from waste-tires as anodes in potassium-ion batteries. The sustainable tire-derived carbons show good reversible potassium insertion at relatively high rates. Long-term stability tests exhibit capacities of 155 and 141 mAh g –1 for carbon pyrolyzed at 1100°C and 1600°C, respectively, after 200 cycles at current rate of C/2. As a result, this study provides an alternative solution for inexpensive and environmental benign potassium-ion battery anode materials.

Temperature distribution in an aircraft tire at low ground speeds

NASA Technical Reports Server (NTRS)

Mccarty, J. L.; Tanner, J. A.

1983-01-01

An experimental study was conducted to define temperature profiles of 22 x 5.5, type 7, bias ply aircraft tires subjected to freely rolling, yawed rolling, and light braking conditions. Temperatures along the inner wall of freely rolling tires were greater than those near the outer surface. The effect of increasing tire deflection was to increase the temperature within the shoulder and sidewall areas of the tire carcass. The effect of cornering and braking was to increase the treat temperature. For taxi operations at fixed yaw angles, temperature profiles were not symmetric. Increasing the ground speed produced only moderate increases in tread temperature, whereas temperatures in the carcass shoulder and sidewall were essentially unaffected.

Sustainable Potassium-Ion Battery Anodes Derived from Waste-Tire Rubber

DOE PAGES

Li, Yunchao; Adams, Ryan A.; Arora, Anjela; ...

2017-04-13

The recycling of waste-tire rubber is of critical importance since the discarded tires pose serious environmental and health hazards to our society. Here, we report a new application for hard-carbon materials derived from waste-tires as anodes in potassium-ion batteries. The sustainable tire-derived carbons show good reversible potassium insertion at relatively high rates. Long-term stability tests exhibit capacities of 155 and 141 mAh g –1 for carbon pyrolyzed at 1100°C and 1600°C, respectively, after 200 cycles at current rate of C/2. As a result, this study provides an alternative solution for inexpensive and environmental benign potassium-ion battery anode materials.

Tailored Recovery of Carbons from Waste Tires for Enhanced Performance as Anodes in Lithium-ion Batteries

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

Naskar, Amit K; Bi,; Saha, Dipendu

2014-01-01

Morphologically tailored pyrolysis-recovered carbon black is utilized in lithium-ion batteries as a potential solution for adding value to waste tire-rubber-derived materials. Micronized tire rubber was digested in a hot oleum bath to yield a sulfonated rubber slurry that was then filtered, washed, and compressed into a solid cake. Carbon was recovered from the modified rubber cake by pyrolysis in a nitrogen atmosphere. The chemical pretreatment of rubber produced a carbon monolith with higher yield than that from the control (a fluffy tire-rubber-derived carbon black). The carbon monolith showed a very small volume fraction of pores of widths 3 4 nm,more » reduced specific surface area, and an ordered assembly of graphitic domains. Electrochemical studies on the recovered-carbon-based anode revealed an improved Li-ion battery performance with higher reversible capacity than that of commercial carbon materials. Anodes made with a sulfonated tire-rubber-derived carbon and a control tire-rubber-derived carbon, respectively, exhibited an initial coulombic efficiency of 80% and 45%, respectively. The reversible capacity of the cell with the sulfonated carbon as anode was 400 mAh/g after 100 cycles, with nearly 100% coulombic efficiency. Our success in producing higher performance carbon material from waste tire rubber for potential use in energy storage applications adds a new avenue to tire rubber recycling.« less

A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process for decentralized wastewater treatment.

PubMed

Krayzelova, Lucie; Lynn, Thomas J; Banihani, Qais; Bartacek, Jan; Jenicek, Pavel; Ergas, Sarina J

2014-09-15

Nitrogen discharges from decentralized wastewater treatment (DWT) systems contribute to surface and groundwater contamination. However, the high variability in loading rates, long idle periods and lack of regular maintenance presents a challenge for biological nitrogen removal in DWT. A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process was developed that combines nitrate (NO3(-)) adsorption to scrap tire chips with sulfur-oxidizing denitrification. This allows the tire chips to adsorb NO3(-) when the influent loading exceeds the denitrification capacity of the biofilm and release it when NO3(-) loading rates are low (e.g. at night). Three waste products, scrap tire chips, elemental sulfur pellets and crushed oyster shells, were used as a medium in adsorption, leaching, microcosm and up-flow packed bed bioreactor studies of NO3(-) removal from synthetic nitrified DWT wastewater. Adsorption isotherms showed that scrap tire chips have an adsorption capacity of 0.66 g NO3(-)-N kg(-1) of scrap tires. Leaching and microcosm studies showed that scrap tires leach bioavailable organic carbon that can support mixotrophic metabolism, resulting in lower effluent SO4(2-) concentrations than sulfur oxidizing denitrification alone. In column studies, the T-SHAD process achieved high NO3(-)-N removal efficiencies under steady state (90%), variable flow (89%) and variable concentration (94%) conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

PubMed Central

Zhang, Xudong; Göhlich, Dietmar

2017-01-01

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

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

PubMed

Zhang, Xudong; Göhlich, Dietmar

2017-01-01

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

Interfacial Properties of EXXPRO(TM) and General Purpose Elastomers

NASA Astrophysics Data System (ADS)

Zhang, Y.; Rafailovich, M.; Sokolov, Jon; Qu, S.; Ge, S.; Ngyuen, D.; Li, Z.; Peiffer, D.; Song, L.; Dias, J. A.; McElrath, K. O.

1998-03-01

EXXPRO(Trademark) elastomers are used for tires and many other applications. This elastomer (denoted as BIMS) is a random copolymer of p-methylstyrene (MS) and polyisobutylene (I) with varying degrees of PMS content and bromination (B) on the p-methyl group. BIMS is impermeable to gases, and has good heat, ozone and flex resistance. Very often general purpose elastomers are blended with BIMS. The interfacial width between polybutadiene and BIMS is a sensitive function of the Br level and PMS content. By neutron reflectivity (NR), we studied the dynamics of interface formation as a function of time and temperature for BIMS with varying degrees of PMS and Br. We found that in addition to the bulk parameters, the total film thickness and the proximity of an interactive surface can affect the interfacial interaction rates. The interfacial properties can also be modified by inclusion of particles, such as carbon black (a filler component in tire rubbers). Results will be presented on the relation between the interfacial width as measured by NR and compatibilization studies via AFM and LFM.

A study of the microstructure and optical properties of thin lead-dielectric cermet films. Ph.D. Thesis - Va. Polytechnic Inst. and State Univ.

NASA Technical Reports Server (NTRS)

Owen, R. B.

1972-01-01

A transmission electron microscopy study involving direct and replicating techniques is directed to a definition of the microstructure of radio frequency-sputtered, thin lead-dielectric cermet films. Once defined, this microstructure is used to obtain theoretical film refractive indices. The Maxwell Garnett theory provides a basis for the theoretical results. Measurements of film transmission and reflectivity are used to obtain rough experimental values for film refractive indices by the Tekucheva method. More exact values are obtained via ellipsometry. The rough Tekucheva values are used to determine the range over which computer calculations interpreting the ellipsometric results must be made. This technique yields accurate values for the film refractive indices.

78 FR 71032 - Foreign Tire Sales, Inc., Denial of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-27

...). ACTION: Denial of Petition. SUMMARY: Foreign Tire Sales, Inc. (FTS), as importer for ProMeter brand... and drive) ProMeter brand medium truck radial tires manufactured during the period between the 15th...

Federal Research on Recycled Tire Crumb Used on Playing Fields

EPA Pesticide Factsheets

Ground rubber is recovered from scrap tires or from the tire retreading process. It is used in road construction and in athletic and recreational applications,like ground cover under playground equipment, running track material, and as a soil additive.

Recycled tires as coarse aggregate in concrete pavement mixtures.

DOT National Transportation Integrated Search

2013-07-01

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

77 FR 65050 - Continental Tire North America, LLC, Mootness of Petition for Decision of Inconsequential...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-24

... certain passenger car replacement tires manufactured in 2009, do not fully comply with paragraph S5.5(b... Continental brand Extremecontact DWS model passenger car tires manufactured from March 2009 to October 2009 at...

Measurement Of Water Sprays Generated By Airplane Tires

NASA Technical Reports Server (NTRS)

Daugherty, Robert H.; Stubbs, Sandy M.

1990-01-01

Experimental investigation conducted at NASA Langley Research Center to measure rate of flow and trajectory of water spray generated by tire operating on flooded runway. Potential application to both aircraft and automotive industries, with particular application to manufacturers of tires.

Develop metrics of tire debris on Texas highways : [project summary].

DOT National Transportation Integrated Search

2017-05-01

This research developed metrics on the amount and characteristics of tire debris generated on Texas highways. These metrics provide numerical, data-based rates for districts to anticipate the amounts and characteristics of tire debris and to plan rem...

Increased efficiency in the second-hand tire trade provides opportunity for dengue control.

PubMed

Pliego Pliego, Emilene; Velázquez-Castro, Jorge; Eichhorn, Markus P; Fraguela Collar, Andrés

2018-01-21

Dengue fever is increasing in geographical range, spread by invasion of its vector mosquitoes. The trade in second-hand tires has been implicated as a factor in this process because they act as mobile reservoirs of mosquito eggs and larvae. Regional transportation of tires can create linkages between rural areas with dengue and disease-free urban areas, potentially giving rise to outbreaks even in areas with strong local control measures. In this work we sought to model the dynamics of mosquito transportation via the tire trade, in particular to predict its role in causing unexpected dengue outbreaks through vertical transmission of the virus across generations of mosquitoes. We also aimed to identify strategies for regulating the trade in second-hand tires, improving disease control. We created a mathematical model which captures the dynamics of dengue between rural and urban areas, taking into account the movement and storage time of tires, and mosquito diapause. We simulate a series of scenarios in which a mosquito population is introduced to a dengue-free area via movement of tires, either as single or multiple events, increasing the likelihood of a dengue outbreak. A persistent disease state can be induced regardless of whether urban conditions for an outbreak are met, and an existing endemic state can be enhanced by vector input. Finally we assess the potential for regulation of tire processing as a means of reducing the transmission of dengue fever using a specific case study from Puerto Rico. Our work demonstrates the importance of the second-hand tire trade in modulating the spread of dengue fever across regions, in particular its role in introducing dengue to disease-free areas. We propose that reduction of tire storage time and control of their movement can play a crucial role in containing dengue outbreaks. Copyright © 2017 Elsevier Ltd. All rights reserved.

Non-thermal irreversible electroporation (N-TIRE) and adjuvant fractionated radiotherapeutic multimodal therapy for intracranial malignant glioma in a canine patient.

PubMed

Garcia, P A; Pancotto, T; Rossmeisl, J H; Henao-Guerrero, N; Gustafson, N R; Daniel, G B; Robertson, J L; Ellis, T L; Davalos, R V

2011-02-01

Non-thermal irreversible electroporation (N-TIRE) has shown promise as an ablative therapy for a variety of soft-tissue neoplasms. Here we describe the therapeutic planning aspects and first clinical application of N-TIRE for the treatment of an inoperable, spontaneous malignant intracranial glioma in a canine patient. The N-TIRE ablation was performed safely, effectively reduced the tumor volume and associated intracranial hypertension, and provided sufficient improvement in neurological function of the patient to safely undergo adjunctive fractionated radiotherapy (RT) according to current standards of care. Complete remission was achieved based on serial magnetic resonance imaging examinations of the brain, although progressive radiation encephalopathy resulted in the death of the dog 149 days after N-TIRE therapy. The length of survival of this patient was comparable to dogs with intracranial tumors treated via standard excisional surgery and adjunctive fractionated external beam RT. Our results illustrate the potential benefits of N-TIRE for in vivo ablation of undesirable brain tissue, especially when traditional methods of cytoreductive surgery are not possible or ideal, and highlight the potential radiosensitizing effects of N-TIRE on the brain.

Flexible Piezoresistive Sensors Embedded in 3D Printed Tires

PubMed Central

Emon, Md Omar Faruk; Choi, Jae-Won

2017-01-01

In this article, we report the development of a flexible, 3D printable piezoresistive pressure sensor capable of measuring force and detecting the location of the force. The multilayer sensor comprises of an ionic liquid-based piezoresistive intermediate layer in between carbon nanotube (CNT)-based stretchable electrodes. A sensor containing an array of different sensing units was embedded on the inner liner surface of a 3D printed tire to provide with force information at different points of contact between the tire and road. Four scaled tires, as well as wheels, were 3D printed using a flexible and a rigid material, respectively, which were later assembled with a 3D-printed chassis. Only one tire was equipped with a sensor and the chassis was driven through a motorized linear stage at different speeds and load conditions to evaluate the sensor performance. The sensor was fabricated via molding and screen printing processes using a commercially available 3D-printable photopolymer as 3D printing is our target manufacturing technique to fabricate the entire tire assembly with the sensor. Results show that the proposed sensors, inserted in the 3D printed tire assembly, could detect forces, as well as their locations, properly. PMID:28327533

Flexible Piezoresistive Sensors Embedded in 3D Printed Tires.

PubMed

Emon, Md Omar Faruk; Choi, Jae-Won

2017-03-22

In this article, we report the development of a flexible, 3D printable piezoresistive pressure sensor capable of measuring force and detecting the location of the force. The multilayer sensor comprises of an ionic liquid-based piezoresistive intermediate layer in between carbon nanotube (CNT)-based stretchable electrodes. A sensor containing an array of different sensing units was embedded on the inner liner surface of a 3D printed tire to provide with force information at different points of contact between the tire and road. Four scaled tires, as well as wheels, were 3D printed using a flexible and a rigid material, respectively, which were later assembled with a 3D-printed chassis. Only one tire was equipped with a sensor and the chassis was driven through a motorized linear stage at different speeds and load conditions to evaluate the sensor performance. The sensor was fabricated via molding and screen printing processes using a commercially available 3D-printable photopolymer as 3D printing is our target manufacturing technique to fabricate the entire tire assembly with the sensor. Results show that the proposed sensors, inserted in the 3D printed tire assembly, could detect forces, as well as their locations, properly.

Treatment of domestic wastewater by subsurface flow constructed wetlands filled with gravel and tire chip media.

PubMed

Richter, A Y; Weaver, R W

2003-12-01

Subsurface flow constructed wetlands (SFCWs) are becoming increasingly common in on-site treatment of wastewater. Gravel is the most popular form of wetland fill medium, but tire chips provide more porosity, are less dense, and less expensive. This study determines the treatment efficiency of SFCWs filled with gravel or tire chip media to treat domestic wastewater. The influent and effluent of six SFCWs filled with tire chip medium and six SFCWs filled with gravel were monitored for 5 to 16 consecutive months. Parameters measured included pH, biochemical oxygen demand (BOD5), total and volatile suspended solids, NH4, P, and fecal and total coliforms. The only clear difference between medium types in wetland performance was for P. Soluble P in the effluent averaged 1.6 +/- 1.0 mg l(-1) in the tire chip-filled wetlands and 4.8 +/- 3.2 mg l(-1) in the gravel-filled wetlands. Most likely, Fe from exposed wires in shredded steel-belted tires complexed with P to create an insoluble compound. Tire chips may be a better fill medium for SFCWs than gravel because of higher porosity, lower cost, and greater reduction of P in effluent.

Non-Thermal Irreversible Electroporation (N-TIRE) and Adjuvant Fractionated Radiotherapeutic Multimodal Therapy for Intracranial Malignant Glioma in a Canine Patient

PubMed Central

Garcia, P. A.; Pancotto, T.; Rossmeisl, J. H.; Henao-Guerrero, N.; Gustafson, N. R.; Daniel, G. B.; Robertson, J. L.; Ellis, T. L.; Davalos, R. V.

2011-01-01

Non-thermal irreversible electroporation (N-TIRE) has shown promise as an ablative therapy for a variety of soft-tissue neoplasms. Here we describe the therapeutic planning aspects and first clinical application of N-TIRE for the treatment of an inoperable, spontaneous malignant intracranial glioma in a canine patient. The N-TIRE ablation was performed safely, effectively reduced the tumor volume and associated intracranial hypertension, and provided sufficient improvement in neurological function of the patient to safely undergo adjunctive fractionated radiotherapy (RT) according to current standards of care. Complete remission was achieved based on serial magnetic resonance imaging examinations of the brain, although progressive radiation encephalopathy resulted in the death of the dog 149 days after N-TIRE therapy. The length of survival of this patient was comparable to dogs with intracranial tumors treated via standard excisional surgery and adjunctive fractionated external beam RT. Our results illustrate the potential benefits of N-TIRE for in vivo ablation of undesirable brain tissue, especially when traditional methods of cytoreductive surgery are not possible or ideal, and highlight the potential radiosensitizing effects of N-TIRE on the brain. PMID:21214290

Discrete retardance second harmonic generation ellipsometry.

PubMed

Dehen, Christopher J; Everly, R Michael; Plocinik, Ryan M; Hedderich, Hartmut G; Simpson, Garth J

2007-01-01

A new instrument was constructed to perform discrete retardance nonlinear optical ellipsometry (DR-NOE). The focus of the design was to perform second harmonic generation NOE while maximizing sample and application flexibility and minimizing data acquisition time. The discrete retardance configuration results in relatively simple computational algorithms for performing nonlinear optical ellipsometric analysis. NOE analysis of a disperse red 19 monolayer yielded results that were consistent with previously reported values for the same surface system, but with significantly reduced acquisition times.

Measurement of the infrared optical constants for spectral modeling: n and k values for (NH4)2SO4 via single-angle reflectance and ellipsometric methods

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

Blake, Thomas A.; Brauer, Carolyn S.; Kelly-Gorham, Molly Rose K.

The optical constants n and k can be used to model infrared spectra, including refraction, absorption, reflectance, and emissivity, but obtaining reliable values for solid materials (pure or otherwise) presents a challenge: In the past, the best results for n and k have been obtained from bulk, homogeneous materials, free of defects. That is, materials where the Fresnel equations are operant since there is no light scattering. Since it is often not possible to obtain a pure macroscopic (crystalline) material, it may be possible to press the material into a (uniform, void-free) disk. We have recently been able to domore » this with ammonium sulfate powder and then measured the n & k values via two independent methods: 1) Ellipsometry - which measures the changes in amplitude and phase of light reflected from the material of interest as a function of wavelength and angle of incidence, and 2) Single angle specular reflectance with an FT spectrometer using a specular reflectance device within an FT instrument which measures the change in amplitude of light reflected from the material of interest as a function of wavelength and angle of incidence over a wide wavelength range. The quality of the derived n & k values was tested by generating the reflectance spectra of the pellet and comparing to the calculated to measured reflectance spectra of the pure material which has been previously published. The comparison to literature values showed good accuracy and good agreement, indicating promise to measure other materials by such methods.« less

14 CFR 25.733 - Tires.

Code of Federal Regulations, 2014 CFR

2014-01-01

... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... suitable tire of proper fit with a speed rating approved by the Administrator that is not exceeded under... wheel with brakes capable of producing this ground reaction. This nose tire load may not exceed 1.5...