bluuebunny/crossref_metadata_2025 huggingface dataset:
BEHSA grafted polymer for selective extraction of U(VI), Th(IV) and La(III) from acidic matrices and environmental samples – a green process
Authors: Raju Ch. Siva Kesava , Subramanian M. S. , Srinivasan T. G. , Rao P. R. Vasudeva
Published: June 2006

A new class of polymeric resin called MCM-BEHSA, for extraction of U(VI), Th(IV) and La(III) was synthesized by grafting Merrifield chloromethylated polymer withN,N-bis-(2-ethyl-hexyl)-succinamic acid. The chemical modifications at each step of the grafting was confirmed by FT-IR spectroscopy, CPMAS solid state NMR spectroscopy, CHN elemental analysis and also by Thermo Gravimetric analysis. All the parameters influencing the quantitative metal ion extraction were optimized by both static and dynamic methods. The resin showed good extractability over a wide range of acidity (0.01-10 M) with fast exchange rate (saturation possible within 20 minutes) and high sorption capacities for U(VI), Th(IV) and La(III). Quantitative metal desorption was achieved by using 0.5 M (NH4)2CO3for all the analytes. A significant feature of this grafted polymer was its ability to extract Th(IV) from very high nitric acid concentrations. Interference studies with commonly encountered metal ions, rare earth ions and electrolytes showed very high tolerance limit for those ions. Enrichment factor values of 400, 550 and 350 with limit of quantification (LOQ) as 10 ng ml-1, 10 ng ml-1and 20 ng ml-1were observed for U(VI), Th(IV) and La(III), respectively. All the analytical data were within 3.2% rsd, reflecting the reproducibility and reliability of the developed method.
Studies on the dissolution behaviour of ThO2 and (U,Th)O2 by a solid state reaction method
Authors: Chaudhury Satyajeet , Keskar Meera , Patil Abhay V. , Mudher K. D. Singh , Venugopal V.
Published: June 2006

A simple and fast method for the dissolution of sintered ThO2 and (U,Th)O2 was developed. The products formed when these oxides were fused with ammonium sulphate at various temperatures were found to be readily soluble in dilute nitric acid. Among all the products obtained at various temperatures, (NH4)2 Th (SO4)3 and (NH4)2(Ux,Th1-x)(SO4)3, obtained at 365 °C, were found highly soluble (>99%). After dissolution thorium was separated selectively by oxalate precipitation method. More than 95% of uranium was recovered from the solution by ammonium diuranate precipitation method. The products formed at different temperatures were characterised by X-ray, thermal and chemical analysis techniques.
Studies on some divalent metal α-isosaccharinic acid complexes
Authors: Warwick Peter , Evans Nick , Vines Sarah
Published: June 2006

The presence of organic complexants, such as α-isosaccharinic acid (ISA) in an intermediate-level radioactive-waste (ILW) repository may have a detrimental effect on the sorption of radionuclides by forming organic complexes in solution. To assess this, stability constants are required for the complexes formed. Constants have been determined for the divalent metal ions, Cd2+, Co2+and UO22+with α-isosaccharinic acid (ISA) in near-neutral and alkaline conditions. The effect of these complexes on radionuclide solubility in the near-field and alkaline-disturbed zone is shown. The constants were measured by the ion-exchange (Schubert) method [1] with the exception of U(VI) at pH 13.3, for which the solubility product method [2] was used. At pH7 each complex was of the form M1ISA1, with log β values suggestive of salt formation. At high pH, log β values were between 13 and 20. The number of hydroxide ions involved in the complexation reactions was determined using Bjerrum plots, conductometric titrations and spectrophotometric methods [1]. The constants have enabled speciation calculations to be performed showing the effect of ISA on the metal's solubility. Solubility is predicted to increase in the presence of ISA from pH 9 to 13.5, suggesting that it may have an impact on radionuclide behaviour. The largest solubility increases are for Cd and Co, the smallest for U(VI).
Preparation and preliminary biological evaluation of a 177Lu labeled nitroimidazole derivative for possible use in targeted tumor therapy
Authors: Das Tapas , Chakraborty Sudipta , Banerjee Sharmila , Sarma Haladhar D. , Samuel Grace , Venkatesh Meera
Published: June 2006

The preparation and preliminary biological evaluation of a metronidazole-BFCA (bifunctional chelating agent) conjugate labeled with 177Lu is reported. Metronidazole, a well known hypoxia marker has been suitably derivatized and coupled with a polyazamacrocyclic BFCA, namely, para-aminobenzyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (p-amino-benzyl-DOTA). 177Lu, which is presently being considered as one of the pivotal radionuclides for targeted therapy was produced in adequate specific activity (∼185 TBq/g) and high radionuclidic purity (99.99%) by irradiating enriched (60.6% 176Lu) Lu2O3 target at a moderate thermal neutron flux of 3×1013 n/cm2/s. The metronidazole-BFCA conjugate was radiolabeled with 177Lu in high radiochemical purity (97%). Preliminary biodistribution studies carried out in Swiss mice bearing fibrosarcoma tumors revealed good tumor uptake (1.30% ID/g at 30 min post-injection) with rapid renal clearance (94.48% ID at 30 min post-injection) and significant tumor to blood (28.00 at 3 h post-injection) and tumor to muscle (14.00 at 3 h post-injection) ratios.
History Keeps Bethlehem Steel from Going off the Rails: Moving a Complex Community Process toward Success
Authors: HOLT SHARON ANN
Published: June 2006

This article chronicles an on-going effort of local community and cultural groups to preserve and interpret the abandoned historic buildings of the Bethlehem Steel Corporation in Bethlehem, Pennsylvania. Advocates for the site, with help from the Mid-Atlantic Regional Center for the Humanities (MARCH), are working with private developers to adapt and re-use the site. Outlining the complex process of persuading city of.cials and developers of the value of saving the plant and the interplay of local, state, regional, and national in.uences that shape the project, the author raises questions about the fragility of a public/private/nonpro.t alliance, suggests new strategies public historians might adopt for industrial sites, and comments on the danger that the expense of saving industrial sites poses to communities, even when history is a community priority. Documents and news coverage relating to the project can be read in full at www.march.rutgers.edu/bethsteel.htm.
The Smithsonian's National Museum of the American Indian: An International Institution of Living Cultures
Authors: EVELYN DOUGLAS E.
Published: June 2006

The mission of the Smithsonian Institution's National Museum of the American Indian is to affirm to Native communities and the non-Native public the historical and contemporary culture and cultural achievements of the Natives of the Western Hemisphere by advancing, in consultations, collaboration and cooperation with them, a knowledge and understanding of their cultures, including art, history and language, and by recognizing the Museum's special responsibility, through innovative public programming, research and collections, to protect, support and enhance the development, maintenance and perpetuation of Native culture and community. Adopted 1990.
Outcomes Associated With Spirometry for Pediatric Asthma in a Managed Care Organization
Authors: Cabana Michael , Slish Kathryn K. , Nan Bin , Leo Harvey , Bratton Susan L. , Dombkowski Kevin J.
Published: June 2006

BACKGROUND. The National Heart, Lung and Blood Institute asthma guidelines recommend that children with asthma receive spirometry testing “at least every 1 to 2 years to assess the maintenance of airway function.”

OBJECTIVE. The purpose of this work was to describe: (1) how often children with asthma receive spirometry testing, (2) what factors are associated with receipt of spirometry testing, and (3) the impact of spirometry testing on subsequent emergency department visits for asthma.

METHODS. We analyzed all pediatric asthma claims data from a university-based managed care organization for a 3-year period (January 2001 to December 2003). We included all of the continuously enrolled patients with active asthma between 7 and 21 years of age. Our outcomes of interest were the presence of ≥1 claim for spirometry testing (Common Procedural Terminology 94010–6, 94060, 94070, or 94150) and the time to emergency department visit. We used multivariate logistic regression to determine factors associated with receipt of spirometry and survival analyses techniques to assess the association between receipt of spirometry with the likelihood of an emergency department asthma visit in the next year, controlling for patient age, gender, severity of illness, and type of insurance.

RESULTS. There were 2688 eligible children of whom 1509 (56%) were male, 324 (12%) had Medicaid insurance, and 624 (24%) had persistent asthma in the initial year. Of the 2688 children, only 612 (23%) had ≥1 claim for spirometry testing during the study period. In all of the multivariate logistic analysis models, increased severity of illness was consistently associated with increased likelihood of receiving spirometry testing. Compared with patients without Medicaid insurance, children with Medicaid insurance were consistently less likely to receive spirometry testing. After adjusting for age, gender, severity, and insurance type, receipt of spirometry did not affect the likelihood of future emergency department asthma use.

CONCLUSIONS. Children with Medicaid insurance are less likely to receive spirometry testing. Reasons may be because of access to care, inadequate provider referral for testing, or patient preferences. Objective lung function tests, such as spirometry, are a potentially important component of monitoring chronic disease status. However, it is not clear whether spirometry testing by itself, completed every 1 to 2 years, helps prevent the likelihood of emergency department asthma visits. Compared with guideline recommendations, spirometry is underused; however, additional work is needed to understand how to best integrate such testing to improve asthma outcomes.
National Estimates of Hospital Use by Children With HIV Infection in the United States: Analysis of Data From the 2000 KIDS Inpatient Database
Authors: Kourtis Athena P. , Paramsothy Pangaja , Posner Samuel F. , Meikle Susan F. , Jamieson Denise J.
Published: June 2006

OBJECTIVES. The purpose of this research was to describe hospital use patterns of HIV-infected children in the United States.

STUDY DESIGN. We analyzed a nationwide, stratified probability sample of 2.5 million hospital discharges of children and adolescents during the year 2000, weighted to 7.3 million discharges nationally. We excluded discharges after hospitalizations related to pregnancy/childbirth and their complications and discharges of neonates <1 month of age and of patients >18 years of age. Diagnoses were identified through the use of the Clinical Classification Software with grouping of related diagnoses.

RESULTS. We estimated that there were 4107 hospitalizations of HIV-infected children in 2000 and that these hospitalizations accounted for ∼$100 million in hospital charges and >30000 hospital days. Infections, including sepsis and pneumonia, were among the most frequent diagnoses in such hospitalizations, followed by diagnoses related to gastrointestinal conditions, nutritional deficiencies and anemia, fluid/electrolyte disorders, central nervous system disorders, cardiovascular disorders, and respiratory illnesses. Compared with hospitalizations of non-HIV-infected children, hospitalizations of HIV-infected ones were more likely to be in urban areas, in pediatric/teaching hospitals, and in the Northeast, and the expected payer was more likely to be Medicaid (77.6% vs 37.2%). Compared with children without HIV, those with HIV tended to be older (median age: 9.5 years vs 5.2 years), to have been hospitalized longer (mean: 7.8 days vs 3.9 days), and to have incurred higher hospital costs (mean: $23221 vs $11215); HIV-associated hospitalizations ended in the patient's death more frequently than non-HIV ones (1.8% vs 0.4%), and complications of medical care were also more common (10.8% vs 6.2%).

CONCLUSIONS. Infections account for the majority of hospitalizations of HIV-infected children in the United States, although nutritional deficiencies, anemia and other hematologic disorders, gastrointestinal and renal disorders, and complications of medical care are also more common among hospitalized children with HIV than among those without HIV.
Pyrimidine (6–4) Pyrimidone Photoproduct Mapping After Sublethal UVC Doses: Nucleotide Resolution Using Terminal Transferase‐dependent PCR
Authors: Rochette Patrick J. , Bastien Nathalie , Todo Takeshi , Drouin Régen
Published: June 2006

UVC irradiation of genomic DNA induces two main types of potentially mutagenic base modifications: cyclobutane pyrimidine dimers (CPDs) and the less frequent (15–30% of CPD levels) pyrimidine (6–4) pyrimidone photoproducts (6–4PP). Ligation‐mediated PCR (LMPCR), a genomic sequencing technique, allows CPD mapping at nucleotide resolution following irradiation with sublethal doses of UVB or UVC for most cell types. In contrast, a dose of 80 J/m2 of UVC that is lethal for the majority of cell types is necessary to map 6–4PP by the LMPCR technique. This compromises the use of LMPCR to study the repair of 6–4PP. To date, no other techniques have been developed to study 6–4PP repair at nucleotide resolution. We have therefore adapted a recently developed technique for the mapping of 6–4PP: terminal transferase‐dependent PCR (TDPCR). TDPCR is in many ways similar to LMPCR. This technique is more sensitive and allows the mapping of 6–4PP at UVC doses as low as 10 J/m2 in genomic DNA and in living cells.
A Median Third Eye: Pineal Gland Retraces Evolution of Vertebrate Photoreceptive Organs†
Authors: Mano Hiroaki , Fukada Yoshitaka
Published: June 2006

In many vertebrates, the pineal gland serves as a photoreceptive neuroendocrine organ. Morphological and functional similarities between the pineal and retinal photoreceptor cells indicate their close evolutionary relationship, and hence the comparative studies on the pineal gland and the retina are the keys to deciphering the evolutionary traces of the vertebrate photoreceptive organs. Several studies have suggested common genetic and molecular mechanisms responsible for their similarities, but largely unknown are those underlying pineal‐specific development and physiological functions. Recent studies have identified several cis‐acting DNA elements that participate in transcriptional control of the pineal‐specific genes. Genetic approaches in the zebrafish have also contributed to elucidating the genetic network regulating the pineal development and neurogenesis. These efforts toward elucidating the molecular instrumentation intrinsic to the pineal gland, back to back with those to the retina, should lead to a comprehensive understanding of the evolutionary history of the vertebrate photoreceptive structures. This article summarizes the current status of research on these topics.
A Simple and Economical Method for Maintaining Precise, Programmable Thermal Regimes in Recirculating Aquatic Mesocosms
Authors: Schaefer Jacob F
Published: June 2006

A programmable and networkable temperature control system was developed for recirculating aquatic mesocosms. The system allows for dynamic diel thermal regimes that are not possible with commercially available temperature controllers. In operation over 2 years from 2004 to 2006, the system has arrays of tanks that were maintained with stable, variable (constant diel cycle) and stochastic (random diel cycle) thermal regimes. As designed, the system's central computer logs the data and changes set points at regular intervals. Because the dual-stage temperature controllers can be operated over a network, the system is easily expanded to accommodate multiple setups. The controllers can also be operated over a wireless network if necessary. In cases in which greater heating and cooling rates are needed, more powerful equipment can be substituted with minimal change to the controller setup.
Experimental Burned Rock Studies on the Edwards Plateau: A View from Camp Bullis, Texas
Authors: Pagoulatos Peter
Published: June 2006

This article presents an experimental study concerning the use of thermally altered stone, commonly referred to as fire-cracked, or burned rock. A series of controlled cooking experiments were initiated as limestone cobbles were placed within a prepared earth-oven and re-heated; this type of earth-oven is similar to those found within prehistoric burned rock mounds on the Edwards Plateau of central Texas. Twelve experiments were conducted in this study, as four different sets of cobble assemblages were each re-heated three times, at six, twelve, twenty-four, and forty-eight hour intervals. These heated limestone cobbles were then analyzed for thermal alteration characteristics such as color change, cracking, and spalling, for comparative purposes. Quantitative analyses were then applied to the data in order to establish whether different patterns of thermal alteration exist dependent upon short-term and long-term re-uses.
Natural Resource and Environmental Economics: A Retrospective View
Authors: Castle Emery N.
Published: June 2006

This article reviews the methodological and theoretical foundations of natural resource and environmental economics prior to an examination of three examples of topics of current interest in the field. The three examples are nonmarket values, benefit—cost analysis, and the new institutional economics. The article draws on the review of contemporary work to identify a number of topics deserving of attention in subsequent work in this field. The items listed would have the effect of making future research more particular and less doctrinaire.
Niche Market Potential: The Case of the U.S. Craft Brewing Industry
Authors: Bastian Chris T. , Oakley-Simpson Deborah M. , McLeod Donald M. , Menkhaus Dale J. , Alsup Dan , Ogden Jeff , Whipple Glen D.
Published: June 2006

This study examines craft brewers as a niche market for the malting industry. Results suggest that catering to craft brewers' needs and preferences offers potential opportunities for malt suppliers. Malt suppliers will have to increase services and provide differentiated malt products to increase demand from craft brewers. This may be a problem for a number of firms that have invested capital to supply large volumes of mass‐produced malt inputs. Malt barley producers may also be able to exploit niche markets as input suppliers to malting facilities.
Agricultural Research: Benefits and Beneficiaries of Alternative Funding Mechanisms
Authors: Huffman Wallace E. , Just Richard E.
Published: June 2006

This article analyzes alternative funding mechanisms for agricultural research and the benefits and beneficiaries of these approaches. Although other mechanisms exist, the discussion focuses on public formula and competitive grants programs, private‐sector contracts and grants, and revenue from sale of intellectual property rights (IPRs) or new products embodying innovations. Over the past two decades, agricultural research has been criticized for the noncompetitive nature of research fund allocations. Considerable evidence exists that the system has performed well for society. We conclude that the private sector should be permitted to carry out research that it finds profitable to undertake with minimal competition from the public sector. The public research institutions should focus on general and pretechnology science programs that complement private research‐and‐development (R&D) activities and conduct applied research in areas in which innovations are socially beneficial but not privately profitable. The mechanism for channeling public funds to researchers (e.g., formula, competitive grants, or earmarks) can be expected to affect the types of benefits/impacts of agricultural research conducted and the efficiency of the research activity. Issues remain about the emphasis on process versus substance in the R&D funding debate. However, available evidence does not suggest the elimination of traditional funding mechanisms for public agricultural research.
Potential Entry of Chile into NAFTA: Are There Lessons from U.S./Mexican Fruit and Vegetable Trade?
Authors: Stanton Julie V.
Published: June 2006

Although the Clinton administration has been unable to obtain fast‐track negotiating authority, eventual expansion of free trade in the hemisphere is likely, and the U.S. position might be affected by the failure to negotiate Chile's entry into NAFTA. One hurdle to broad‐based support for Chile's entry is U.S. horticulture producers' claims of “injury” from NAFTA trade. We argue that (a) considerable empirical evidence acquits NAFTA of these charges, (b) liberalizing Chile's strict trade barriers should yield significant U.S. gains, and (c) NAFTA's combined trade‐investment reform facilitates U.S. foreign agricultural investment. Together these benefits imply that resistance to Chile's entry is unwarranted.
New Process for Preparing Tire Tread Compounds Having Low Rolling Resistance
Authors: Hirakawa H. , Ahagon A.
Published: June 2006

Two-stage mixing when applied to blends of Chlorobutyl Rubber (C1-IIR), Natural Rubber (NR), and Polybutadiene Rubber (BR), can produce tread compounds exhibiting a combination of very low hysteresis, good wet skid resistance, and good abrasion resistance. In the first stage, about half the raw rubber, including all C1-IIR and BR, is mixed with most of the carbon black to form a very high carbon black stock. In the second stage, the first-stage stock is diluted with the remaining NR. Curatives, etc., are added on the mill. Tests on radial tires for automobiles confirm the advantages of the two-stage mixed tri-rubber blend tread compounds.
Mallory Tube Test: Analyses of Deformation and Heat Generation
Authors: Beringer C. W. , Kwon Y. D. , Prevorsek D. C. , Causa A. G.
Published: June 2006

Experimental observations of the cyclic deformation and temperature rise in Mallory tubes during testing are described. The analyses of the data explain the temperature rise in terms of heat generated by the cord and rubber during the cyclic deformation. Using the measured temperature rise and the heat generative characteristics of cord and rubber, the effective strain amplitude of the cyclic deformation is calculated. This effective strain amplitude is compared and found to be consistent with the strain amplitude measured from photographs of the tube contour during testing. The study also reviews some of the factors affecting the results of the test and proposes an explanation for the differences in durability between tubes reinforced with nylon 6 and nylon 66..
Analysis and Computation of Energy Loss in Radial Tires
Authors: Chakko M. K.
Published: June 2006

A comprehensive but simple analytical model for predicting the energy loss in radial tires is presented. Using approximate structural analysis, the model relates the basic material properties and construction variables of the tire to its energy loss or rolling resistance. The formulas developed were computer-programmed, and the tire rolling resistance and its distribution among the components of a typical radial automobile tire were computed. The significant contributions to rolling resistance were from tread compression, carcass cord extension and bending, and sidewall rubber bending. Parametric studies using the computer program were carried out to obtain the trends in rolling resistance due to changes in several tire material properties and construction variables. The computations also showed the existence of locally optimum values for the tread modulus, carcass cord modulus, and carcass cord end count which minimize the tire rolling resistance.
Contact Loading of a Rubber Disk
Authors: Ridha R. A. , Satyamurthy K. , Hirschfelt L. R. , Holle R. E.
Published: June 2006

A computational method is described for the analysis of deformable bodies loaded against rigid surfaces. The deformable body is modeled by three-dimensional isoparametric elements. A contact algorithm determines the nodes that come into contact with each loading step; the finite element analysis computes the size and shape of the footprint and the distribution of contact pressure in the footprint. The procedure is illustrated by analysis of the contact of a rubber disk. The close agreement, shown between the computed and measured results for the rubber disk, demonstrates the potential of the technique for 3D contact analysis of pneumatic tires.
Determination of Tire-Road Friction Coefficients for Skid Mark Analysis
Authors: Garrott W. R. , Guenther D. A.
Published: June 2006

An experimental study was made to compare the validities of methods currently used by accident reconstructionists to determine the coefficient of friction between the road and the vehicle tires at the time of an incident. This value could then be used in conjunction with skid mark length and vehicle weight to calculate the prebraking speed of the vehicle. Three automobiles and three trucks with a variety of tires and loadings were used on a variety of pavements. The accuracy and area of applicability of each of four methods for obtaining friction coefficients were determined by relating the prebraking speed calculated from each to the actual speed at the time of brake application. All four methods were satisfactory for automobiles and the pickup truck used, but only two were acceptable for heavy trucks. The most valid coefficients are obtained from skid mark lengths obtained under conditions duplicating those in an incident.
Interactive Graphics for the Analysis of Tires
Authors: Prabhakaran R.
Published: June 2006

The finite element method, which is a numerical discretization technique for obtaining approximate solutions to complex physical problems, is accepted in many industries as the primary tool for structural analysis. Computer graphics is an essential ingredient of the finite element analysis process. The use of interactive graphics techniques for analysis of tires is discussed in this presentation. The features and capabilities of the program used for pre- and post-processing for finite element analysis at GenCorp are included.
Pantographing Self-Adaptive Gap Elements
Authors: Padovan J. , Moscarello R. , Stafford J. , Tabaddor F.
Published: June 2006

A pantographing self-adaptive gap element type contact strategy is presented. Due to the manner of its formulation, it can handle large deformations in the contact zone, contact initiation in a structure that has either positive or indefinite stiffness characteristics, kinematic and material nonlinearities, as well as self-adaptive load (time) stepping. Contact in pre- and post-buckling structures can be treated in this context. Several illustrative benchmark problems are given. These include coming into contact with a fiat surface, and involve large deformation kinematics and inelastic behavior as well as pre- and post-buckling stiffness characteristics.
Displacements and Stresses Resulting from Contact of a Steel Belted Radial Tire with a Flat Surface
Authors: DeEskinazi J. , Yang T. Y. , Soedel W.
Published: June 2006

The displacements and stresses in a steel belted radial tire in contact with a flat surface are analyzed by the use of the finite element method. The tire configuration is modeled by using flat triangular plate elements. The radial profile is divided into four zones and each zone is assumed to be piecewise homogeneous. The material properties for each zone are obtained directly from a separate experimental study. Such laminate property is included in the formulation of the stiffness matrix of the triangular plate element. An incremental stiffness matrix based on the quadratic terms in the strain-displacement equations is also formulated for the element. The geometrically nonlinear behavior of the finite element model is predicted by a linear incremental procedure. The distributions of displacement, membrane stress, and bending stress throughout the tire are computed. The results for sidewall deflections resulting from inflation and the spring constant of the tire are compared with experimental measurements.
Road Surface Bulk Water Drainage—A Theoretical Study
Authors: Bond R. , Lees G.
Published: June 2006

A theoretical approach to bulk water drainage properties at the tire/road surface interface for a freely rotating tire is presented. The results show that it is possible to optimize the road surface macrotexture conditions (aggregate size, aggregate spacing, and absolute texture depth) to give the minimum time for removal of bulk water from the interface yet give the maximum possible actual area of contact between the tire and road surface to obtain the maximum possible friction levels.
A Study on Asymmetries in Tire Forces
Authors: Galli E. , Raggi R.
Published: June 2006

A formalism has been developed to analyze tire force data when asymmetries resulting from the intrinsic characteristics of the tires occur. Identifying and eliminating spurious signals from the measuring equipment has been found to be simple. The formalism is based on the decomposition of the force in independent terms, characterized by well-defined symmetry properties. As an application, lateral force asymmetries are analyzed. Further, the concepts of pseudocamber and pseudoslip are generalized to include slip angles different from zero.
Rolling Resistance of Pneumatic Tires
Authors: Clark S. K.
Published: June 2006

Linear relations have been observed experimentally between tire equilibrium rolling resistance, tire load, and the reciprocal of tire inflation pressure. These variables are used to formulate a simple general expression for rolling resistance, and predictions made with this expression are compared with measured data.
Relationship of Tire Rolling Resistance to the Viscoelastic Properties of the Tread Rubber
Authors: Lou A. Y. C.
Published: June 2006

For radial and belted bias automobile tires having replicate bodies but different tread materials, the rolling resistance force was found to be nearly a linear function of the tread material loss ratio (fractional hysteresis) measured at either constant strain or constant stress. Loss ratio is calculated as the ratio of energy loss (hysteresis) to total energy input obtained from constant crosshead speed (sawtooth) loading cycles on an Instron tester. Good correlation was also observed between rolling resistance force and a viscoelastic index (loss tangent) obtained from sinusoidal strain cycles on a Rheovibron instrument. When related to energy loss of the tread, rolling resistance showed good correlation only for a series of natural rubber compounds of varied black content; a tread based on a solution styrene-butadiene rubber polymer fell outside the natural rubber pattern.
A Note on Tire Carcass Mechanical Properties
Authors: Tielking J. T. , Martin R. E. , Schapery R. A.
Published: June 2006

Uniaxial stress tests were conducted on composite specimens cut from two different locations on a bias tire carcass. These data together with cord data, the Halpin-Tsai “micromechanics” equations, and the linear laminate constitutive equations are used to derive the in-situ rubber modulus as a function of time and to check for consistency among the specimens tested. The main purpose of the first part of the study was to obtain constituent material properties for use in a finite element model of a tire. This model is then employed in the investigation of the influence of uniform rubber modulus on the shape of an inflated tire carcass, and it is concluded that the strain and time dependence of the rubber modulus will introduce some error in a tire structural analysis that uses linear elastic stress-strain equations and permits geometric nonlinearity. It appears that the error will be minimal in a low strain region such as in the sidewall.
The Adequacy of Linear Models in Tread Life Testing
Authors: Wright C. T.
Published: June 2006

This paper examines the assumption of linearity in the application of regression techniques to tread wear data. Data from several sources provide evidence that tread wear is only approximately linear. Linear models appear to be adequate after a sufficient break-in period whose length depends on the nature of the test. When linear models are used to compare the tread life potential of a test tire to that of a control tire, both tires must have had the same testing exposure or else the rate of wear may be overestimated.
A Note on Patterns of Wear Within the Tread Area
Authors: Brenner F. C. , Kondo A.
Published: June 2006

Tread wear data are frequently fitted by a straight line having average groove depth as the ordinate and mileage as the abscissa. The authors have observed that the data points are not randomly scattered about the line but exist in runs of six or seven points above the line followed by the same number below the line. Attempts to correlate these cyclic deviations with climatic data failed. Harmonic content analysis of the data for each individual groove showed strong periodic behavior. Groove 1, a shoulder groove, had two important frequencies at 40 960 and 20 480 km (25 600 and 12 800 miles); Grooves 2 and 3, the inside grooves, had important frequencies at 10 240, 13 760, and 20 480 km (6400, 8600, and 12 800 miles), with Groove 4 being similar. A hypothesis is offered as a possible explanation for the phenomenon.
Prediction of Tire Tread Wear Rate and Tread Wear Rate Differences
Authors: Dudley E. A. , Bauer R. F. , Reilly P. M.
Published: June 2006

A method is presented for the analysis of tread wear test data, having the principal aim of predicting the ultimate tread life from results of a test suspended near the halfway mark. This method uses standard regression analysis of a suitable model followed by Bayesian inference to produce subjective probability distributions of predicted tread depth and their associated uncertainty.
Simplified Prediction of Ply Steer in Radial Tires
Authors: Bert C. W.
Published: June 2006

Ply steer is a rolling contact phenomenon which manifests itself as a lateral force acting at the ground plane of a tire constrained in yaw or a change in slip angle of a tire free to yaw. It has long been known that radial tires generally exhibit greater ply steer than do bias tires. However, the only previously published quantitative analysis of this phenomenon considered the multi-layer cord-rubber composite by means of netting analysis, which is not very accurate at cord angles typical of radial tire belts. A simple, explicit expression is developed herein by combining modern composite laminate theory with two very simple, uniform-stress-state tire-road contact models. The ply-steer results predicted by the resulting expressions are compared with some experimental results and the agreement is found to be reasonably satisfactory.
A Thermomechanical Approach to Tire Power Loss Modeling
Authors: Whicker D. , Browne A. L. , Segalman D. J. , Wickliffe L. E.
Published: June 2006

The increasing emphasis on improving fuel economy has created a need for a good analytical model for predicting tire power loss. Some of the existing tire power loss models are first reviewed and deficiencies noted, principal among these being the constitutive theory used to characterize tire materials, the model for the tire-pavement interaction, the model to account for the changing thermal state of the tire, and the model representing the interaction between the thermal and the mechanical states of the tire. The characteristics of an ideal power loss model are then outlined, its conceptual basis is presented, and the specific tasks needed to develop it and eliminate the previously listed deficiencies are discussed. Required experimental inputs to the model are enumerated. Finally, preliminary results are presented which demonstrate the feasibility of the approach.
Patterns of Tread Wear and Estimated Tread Life
Authors: Brenner F. C. , Kondo A.
Published: June 2006

Tire wear data from two tread wear tests on different courses have been analyzed to determine how patterns of wear are affected by the course. The coefficient of variation (CV) was used as a measure of irregular wear. Tires which exhibited irregular wear (large CV) exhibited the same pattern of wear on both courses; that is, the location of the fastest wearing ribs was unchanged. Those that wore more evenly showed distinct differences in wear pattern on the two courses although all ribs wore at about the same rate. However, some of the changes observed for particular brands of tires may have been the result of tire design changes. Tread life was projected for tires based on the fastest disappearing groove and on the average of all groove depth readings. The rankings of the tires by both methods on the two courses were highly correlated; there does not appear to be any advantage to one method over the other for relative rating.
Analysis of the Wear of Multisectioned Tire Treads
Authors: Derringer G. C.
Published: June 2006

The meaningfulness of multisectioned tire tests has been the subject of considerable controversy for many years. In this exposition analysis of the data from such tests is discussed from a statistician's point of view. The applicable statistical model for analyzing such data is discussed, as well as data transformation and estimation of tire-compound interaction effects. It is concluded that, given the proper analysis, multisectioned tire tests are a valid means for comparing treadwear of several compounds.
Resonant Sound and Vibration Characteristics of a Truck Tire
Authors: Reiter W. F.
Published: June 2006

Bias ply truck tire resonant vibration and sound fields were evaluated in the laboratory by standard vibration and sound measurement procedures. Four resonances were isolated between 90 and 250 Hz. Analysis of the sound and vibration fields showed that each isolated resonant mode radiates acoustic energy like a simple source. The modes investigated were determined to be acoustically slow with the attendant acoustic radiation emanating from a region within ¼ wavelength of the tire footprint.
Uniformity of Tires at Vehicle Operating Speeds
Authors: Walker J. C. , Reeves N. H.
Published: June 2006

The general trend of the forces generated by a nonuniform tire and wheel as a function of speed has been available for several years. As a rule it has been found that the first harmonic of the force variation is the greatest single contributory factor in those vehicle shake problems originating at the tire and wheel. The paper shows how the first harmonic varies with speed for a batch of tires, and, in particular, discusses the phase and amplitude relationship between longitudinal force variation and radial force variation with speed; a mathematical analysis is given. Attempts to counteract the high speed nonuniformity forces by using balance weights on the wheel are reported. The relative effect of the tire and the wheel is considered. Also, the application of this work as a vehicle shake diagnostic technique to isolate tire wheel assembly and vehicle effects is discussed.
Tire Testing for Rolling Resistance and Fuel Economy
Authors: Glemming D. A. , Bowers P. A.
Published: June 2006

The rolling resistance of tires and the fundamental factors influencing rolling resistance during laboratory and road testing are discussed. Test methodologies for vehicle fuel consumption, vehicle coast-down, rolling resistance trailer measurements, and laboratory testing are described. This paper is confined to passenger tire characteristics and deals primarily with test techniques, although some observations are made regarding tire construction, the effect of environment, comparison of test methods, test parameter effects, and the interrelationships between various test modes.
Traction-Abrasion Relationships of Tread Compounds Containing New Reinforcing Blacks
Authors: Boonstra B. B.
Published: June 2006

Abradibility and braking force coefficient (BFC) were determined on compounds of various elastomers and fillers, using a modified Lambourn abrader. Butyl rubber showed the highest BFC and butadiene rubber the lowest, with SBR intermediate. While the effect of carbon black type is not as large certain types of carbon black imparted not only improved traction (“wet” BFC) to tread compounds but also increased wear resistance, in contrast to other methods of improving traction which invariably lead to lower abrasion resistance. The laboratory relationship was confirmed on actual tires on a special trailer and on a test fleet car.
A Model Analysis of the Structural and Pneumatic Contributions to Tire Behavior Under Vertical Loads
Authors: Nicholson D. W.
Published: June 2006

An inflated ring under compression between rigid, flat, parallel plates is used to provide a simple analysis for the structural and pneumatic contributions to the behavior of tires under vertical loading. The fundamental assumption is the additivity of the solutions for the limiting cases of pure bending and of pure membrane behavior, for which exact solutions in simple form are given. Bounding curves for contact width and pressure changes are given as functions of deflection. The computed force-deflection relations exhibit linearity up to a high deflection.
Effects of Tire Rolling Resistance on Vehicle Fuel Consumption
Authors: Crum W. B. , McNall R. G.
Published: June 2006

Variation in the effects of tire rolling resistance on passenger car fuel consumption seldom exceeds ten percent. The definition of these effects is therefore a problem in experimental design and control, measurement precision, and careful accounting for uncontrolled variables.

A rolling resistance test conducted on a road surface with a fully instrumented tire test trailer is described and the test results presented. Fuel “economy” test techniques are discussed with emphasis on precautions and recommendations for reliable testing and test results presented. When aerodynamic drag is taken into account with wind tunnel measurements, the results are suggestive of engine characteristic curves.
Contact of an Inflated Toroidal Membrane with a Flat Surface as an Approach to the Tire Deflection Problem
Authors: DeEskinazi J. , Soedel W. , Yang T. Y.
Published: June 2006

A finite element procedure has been developed for the displacement and stress analysis of a homogeneous and isotropic inner tube mounted on a rim and in contact with a flat surface. The geometric nonlinear effect is accounted for by including the quadratic terms in the strain-displacement equations. The nonlinear load-displacement path is predicted by a linear incremental procedure. The procedure is first demonstrated by a large deflection analysis of a strip of a tire (a cable). The results are in good agreement with a known alternative solution. A homogeneous and isotropic inner tube is then pressurized and the displacements and stresses are found. The displacements are also found experimentally. Both results are in good agreement. Finally, the inner tube is mounted on a rim and pressed against a rigid flat surface. The resulting displacements and footprints are also measured experimentally. The computer results are shown to be in reasonable agreement with the experiment.
Measurement of Steady State and Transient Aircraft Tire Forces
Authors: Brewer H. K.
Published: June 2006

Studies of aircraft directional control during takeoff and landing are best carried out with programmed simulators in which the pilot interacts directly with the aircraft systems. A vital input to such simulations is accurate tire force data, which at the present time are difficult to obtain because of lack of experimental facilities. This paper describes new test equipment for measuring aircraft tire forces which is now available at the Air Force Flight Dynamics Laboratory, Wright-Patterson Air Force Base. Sample data are presented and discussed which pertain to conventional and experimental radial ply aircraft tires.
Infrared Inspection of Nonpneumatic Rubber Road Wheels
Authors: Wilburn D. K.
Published: June 2006

The examination of twelve used solid rubber road wheels by an infrared (IR) temperature profiling technique during drum test experiments is described. The IR method was evaluated as a noncontact means of predicting road wheel integrity by analysis of the circumferential temperature profile. The effectiveness of the temperature profiling method was determined by stripping the rubber from each wheel and visually evaluating the bond interface and rubber tread. Known defects in the used wheels were used to evaluate the IR examination method. Left and right sidewall and tread area were examined simultaneously by use of three sensor heads which were mounted in a test rig positioned around the test wheel. Results indicate that the IR test technique has a capability of detecting cracks and chunking in the rubber tread, gross unbonded areas and interface delamination, and large-area entrapped foreign objects at the rubber-to-metal interface. Low bond strength and small unbonded areas less than one square inch were not detected. Defects located along the left sidewall area were more difficult to sense because of the wear flange and high thermal coupling with the metal sidewall, which dissipated tread-developed heat.
Mechanical Properties of an Off-the-Road Tire
Authors: Skele P. , Brookman B. J.
Published: June 2006

Four 20.5-25/16 PR off-the-road tires have been tested in order to obtain their static and dynamic properties. Quasi-static tests were performed to obtain static spring rates and loss energies. Drop tests were conducted with various weights and tire inflation pressures to obtain dynamic spring rates and damping coefficients. Dynamometer tests were performed at various loads, speeds, and inflation pressures in order to determine temperature buildup. Yawed roll tests are reported that provide carpet plots of cornering force and aligning torque versus slip angle and normal load.
Tire Cornering Properties
Authors: Bergman W. , Clemett H. R.
Published: June 2006

This paper provides a critical review of tire test techniques, test equipment, data processing methods, and mathematical models for obtaining data and describing tire cornering properties. It examines applicability of this data for evaluation of vehicle directional response properties and shows how test and data processing methods influence tire parameters used in simulations with models. Mathematical relationships between tire parameters and vehicle directional response parameters such as steering sensitivity are shown. Fundamental differences between conditions prevailing in testing, hypothetical assumptions used in mathematical models, and actual tire operating conditions on a vehicle are discussed. The need for transient tire measurements and modeling for transient conditions is also shown.
The Significance of Tread Element Flexibility to Thin Film Wet Traction
Authors: Browne A. L. , Whicker D. , Rohde S. M.
Published: June 2006

An analysis is presented for the action of individual tire tread elements on polished sections of pavement covered by thin fluid films. Tread element flexibility, wheel slip, and time-dependent loading are incorporated. The effect of the lateral expansion of tread elements on groove closure is also studied.