The purpose of this research was to compare the rutting, cracking, and development of roughness of two asphalt overlay types commonly used in northern Utah and to evaluate how well the Mechanistic-Empirical Pavement Design Guide (MEPDG) can predict the observed results. AC-10 and PG 64-34 asphalt overlay materials were paved in a checkerboard pattern at a test site on State Route 30 near Logan, Utah, and observed for 3 years at 6-month intervals. Primary data included rutting, cracking, and roughness. At the conclusion of the 3-year evaluation period, rut depths were 0.08 in. deeper, on average, in the AC-10 overlay compared to the PG 64-34 overlay. Fatigue cracking in the PG 64-34 overlay exceeded that in the AC-10 overlay by 0.11 percent, on average. The measured roughness of the PG 64-34 overlay was greater by 24 in./mile, on average, than the AC-10 overlay. In summary, although the AC-10 product exhibited more rutting than the PG 64-34 product, the latter exhibited more fatigue cracking and greater roughness than the former. Although the MEPDG predictions for rutting are within the range of observed rut depths, the MEPDG overestimated the AC-10 rut depth while underestimating the PG 64-34 rut depth. Furthermore, the apparent inability of the MEPDG to predict amounts of longitudinal, fatigue, and transverse cracking comparable to measured values is concerning; the MEPDG predicted negligible cracking for both overlay types for the duration of the 3-year analysis period. While the MEPDG cracking models appear to be unsuitable for predicting cracking at this site, the MEPDG predictions for roughness are shown to be within the range of observed values. Given the findings of this study, the researchers recommend that Utah Department of Transportation (UDOT) engineers consider specifying the AC-10 asphalt overlay product for pavement treatments in conditions similar to those evaluated in this investigation. Even though the MEPDG predictions of rutting and roughness were generally correct, the researchers recommend that such predicted values be used as general predictions only. Further evaluation of these models, as well as the MEPDG models for longitudinal, fatigue, and transverse cracking, should be completed before the MEPDG is fully adopted by UDOT.

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The general trend toward increased use of computer models and simulations during product development has led to a need for accurate and reliable product models. The function of many products relies on contact interfaces between interacting components. To simulate the behavior of such products, accurate models of both components and interfaces are required. Depending on the purpose of the simulation, interface models of different degrees of complexity are needed. In simulation of very large systems with many interfaces, it might be computationally expensive to integrate detailed models of each individual interface. Condensed models, or abstractions, that describe the interface properties with a minimum of degrees of freedom are therefore required. This thesis deals with mechanical interfaces with an emphasis on friction. In the four appended papers friction models are discussed in terms of condensed models, as well as in terms of more detailed contact models. The aim is to study how friction can be modeled in behavioral simulation of products and to discuss the convenience and relevance of using different types of friction models as building blocks of a system model in behavioral simulations. Paper A presents a review of existing condensed friction models for sliding contacts under different running conditions and discusses the models from both simulation and tribological points of view. In papers B and C a simplified contact model, called the elastic foundation model, is used to model friction in a boundary-lubricated rolling and sliding contact. The model is integrated in a dynamic rigid body model of a mechanical system, the system behavior is simulated, and the result is compared with experimental results. Paper D discusses the application of the elastic foundation model to rough surface contact problems and investigates how the error in the elastic foundation results depends on surface roughness. / QC 20101129

In today’s paper and board production, quality control is made on a single cross direction (CD)sample from each tambour. As several different properties are analysed, only a limited number of measurement results are obtained for one property. Therefore, the measurement results might not be representative for the properties of the entire width of the tambour. The first objective of the project was to investigate variations of thickness, surface roughness and mechanical properties with a much higher resolution and number of measurements. The results of the measurement were compared with the routine quality control of the mill. The second objective of the project was to evaluate the influence of the wire shake unit in the centreply on the properties of the produced board. The measurements were performed on Iggesundpaperboard samples.The high-resolution measurements were performed using the STFI structural thicknessmeasurement device, an OptiTopo topography measurement device and a modified Autolinedevice at RISE Bioeconomy. The statistical evaluation of the results was performed in Matlab.Standard deviation, local variance and a frequency analysis were calculated for the thicknessmeasurements. Only standard deviation was considered for the topography data. For the mechanical properties, the distribution was evaluated using the Weibull distribution, since theresults had a single-sided distribution. In addition, the properties were analysed as a function of their location, for example to identify deterministic deviations in cross direction.The results of the first part of the project showed that the everyday control conducted in Iggesund is sufficient for most of the properties. Greatest difference was found at the edges ofthe samples, where Iggesund standard quality control does not detect a major variation inproperties, as no measurements are performed that close to the edge of the web. For example,at one edge, the high frequent measurements showed a significant drop in thickness which were not detected with the everyday quality control.In the second part of the project, the effect of a shake unit on the paper properties was evaluated. Here it was seen that the thickness variation were reduced, which also can be interpreted as an improvement of formation in the centre ply of the paperboard. As for thesurface roughness a slight improvement was found. Also for the mechanical properties, the shake unit appeared to improve the uniformity of the product / I dagens pappers-och kartongproduktion görs kvalitetskontroll på en enda tvärremsa (CD) från varje tambour. Eftersom flera olika egenskaper analyseras, erhålls endast ett begränsat antal mätresultat för en egenskap. Därför är informationen begränsad och kanske inte representativ för hela bredden av tambours egenskaper. Projektets första mål var att undersöka variationer i tjocklek, ytjämnhet och mekaniska egenskaper med mycket högre upplösning och antal mätningar. Resultaten av mätningen jämfördes med brukets rutinmässiga kvalitetskontroll.Det andra syftet med projektet var att utvärdera effekten av viraskaken på egenskaperna hos den producerade kartongen. Samtliga mätningar utfördes på kartongprover från IggesundsBruk.Mätningarna med hög upplösning utfördes med hjälp av en STFI-mätare för strukturtjocklek,en OptiTopo-enhet och en modifierad L&W Autoline-enhet. Den statistiska utvärderingen avresultaten utfördes i Matlab. Standardavvikelse, lokal variation och en frekvensanalys beräknades för tjockleksmätningarna. Endast standardavvikelse utvärderades för ytråhetsdata.För de mekaniska egenskaperna utvärderades fördelningen med hjälp av Weibullfördelningen,eftersom resultaten visade ett ensidigt beteende. Dessutom analyserades egenskaperna som en funktion av deras placering, till exempel för att identifiera deterministiska avvikelser i tvärriktningen.Resultaten av projektets första del visade att den dagliga kontrollen i Iggesund är tillräcklig för de flesta egenskaperna. Den största skillnaden hittades vid provets kanter, där Iggesundsstandardkvalitetskontroll Missar stora variationer för vissa egenskaper, eftersom inga mätningar utförs i det området på produkten. Vid ena sidan av nätverket visade de högfrekventa mätningarna en betydande minskning av tjockleken.I den andra delen av projektet utvärderades effekten av en skakningsenhet på pappersegenskaperna. Här såg man att variansen i tjockleksmätningarna indikerar en förbättring av formationen i kartongens mittskikt. När det gäller ytråheten konstaterades en liten förbättring. För de mekaniska egenskaperna föreföll viraskaken förbättra produktenslikformighet.

Thermal barrier coatings (TBCs) have been widely used in gas turbine engines to protect the underlying metal from high operating temperature so as to improve the durability of the components and enhance the engine efficiency. However, since the TBCs always operate in a demanding high-temperature environment of aircraft and industrial gas-turbine engines, a better understanding of this complex system is required to improve the durability and reliability. The objective of this study is to investigate the effects of surface modification for the NiCoCrAlY bond coats on the thermal cycling lifetime and failure characteristics of TBCs. Parameters of modification for the bond coats included as-sprayed, barrel-finished, hand-polished and pre-oxidation heat treatment at 1100[degrees]C in P=10O2-8 atm up to 4 hours, carried out prior to the electron beam physical vapor deposition (EB-PVD) of ZrO2-7wt% Y2O3 (7YSZ) ceramic topcoat. The resulting characteristics of the bond coat and the thermally grown oxide (TGO) scale were initially documented by surface roughness, phase constituents of the TGO scale, and residual stress of the TGO scale. The thermal cycling test consisted of 10-minute heat-up to 1121°C, 40-minute hold at 1121°C, and 10-minute forced air-quench. As-coated and thermally-cycled TBCs were characterized by optical profilometry (OPM), photo-stimulated luminescence spectroscopy (PSLS), optical microscopy, scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), and scanning/transmission electron microscopy (TEM/STEM) equipped with high angle annular dark field (HAADF) and X-ray energy dispersive spectroscopy (XEDS). TBC specimens for TEM/STEM analysis were prepared by focused ion beam (FIB) in-situ lift-out (INLO) technique. Superior thermal cycling lifetime was observed for TBCs with as-sprayed bond coats regardless of pre-oxidation heat treatment, and TBCs with hand-polished bond coats only after pre-oxidation heat treatment. With pre-oxidation heat treatment, relative photostimulated luminescence intensity of the equilibrium α-Al2O3 increased. Thus, the improvement in TBC lifetime can be correlated with an increase in the amount of α-Al2O3 in the TGO scale, given a specific surface modification/roughness. The lifetime improvement due to pre-oxidation was particularly significant to TBCs with smooth hand-polished bond coats and negligible for TBCs with rough as-sprayed bond coats. Spallation-fracture paths depended on the lifetime of TBCs. Premature spallation of TBCs occurred at the interface between the YSZ and TGO. Longer durability can be achieved by restricting the fracture paths to the TGO/bond coat interface. Small particulate phase observed through the TGO scale was identified as Y2O3 (cubic) by diffraction analysis on TEM. While small addition of Y in the NiCoCrAlY bond coat helps the adhesion of the TGO scale, excessive alloying can lead to deleterious effects.

Rating scales are commonly used to study voice quality. The purpose of this study was to examine inter-rater reliability/agreement of graduate student clinicians with differing levels of experience in rating voice perception. The Consensus Auditory Perception Evaluation of Voice (CAPE-V) was used to asses 1.) overall severity, 2.) roughness, 3.) breathiness, 4.) strain, 5.) pitch and 6.) loudness from a sample of pediatric voices. Twenty-four graduate clinicians who had completed a graduate level course in voice disorders participated in the study. Twelve of the participants were randomly selected to complete a perceptual training course prior to the evaluation session. Voice samples included 10 disordered and 2 normal voices from a population of children age 3-10 years old. The 12 voice samples were randomly repeated 3 times. Results of analysis of variance indicated that the groups significantly differed in their severity rating of the perceptual indices, suggesting that training affected the participants' judgment of severity. Additionally, variability was reduced as a function of training. Pearson product-moment correlation coefficient's revealed a moderate to strong relationship for all of the perceptual indices suggesting that regardless of training participants have an implicit understanding of normal versus disordered voice samples.

The Aquarius/SAC-D is an Earth Science remote sensing satellite mission to measure global Sea Surface Salinity (SSS) that is sponsored by the NASA and the Argentine Space Agency (CONAE). The prime remote sensor is the Aquarius (AQ) L-band radiometer/scatterometer, which measures the L-band emitted blackbody radiation (brightness temperature) from the ocean. The brightness temperature at L-band is proportional to the ocean salinity as well as a number of physical parameters including ocean surface wind speed. The salinity retrieval algorithm make corrections for all other parameters before retrieving salinity, and the greatest of these is the increased brightness temperature due to roughness caused by surface wind speed. This thesis presents an independent approach for the AQ roughness correction, which is derived using simultaneous measurements from the CONAE Microwave Radiometer (MWR). When the wind blows over the ocean’s surface, the brightness temperature is increased because of the ocean wave surface roughness. The MWR provides a semi-empirical approach by measuring the excess ocean emissivity at 36.5 GHz and then applying radiative transfer theory (improved ocean surface emissivity model) to translate this to the AQ 1.4 GHz frequency (L-band). The theoretical basis of the MWR algorithm is described and empirical results are presented that demonstrate the effectiveness in reducing the salinity measurement error due to surface roughness.

Research was performed to analyze the performance of the crack, seat, and overlay (CS&O) roadway rehabilitation technique in the Central Coast and Northern regions of California. This technique was evaluated through literature review to determine the state of practice and their conclusions. California highway sections rehabilitated using CS&O were selected for evaluation based on age and location. Pavement distresses and traffic data for these sections were collected and analyzed. Prior to beginning analysis this data was checked for errors, outliers, and omissions. The analysis consisted of checking the data for correlations among distresses and regions. The focus of this research is to develop performance prediction models for pavement distresses in CS&O sections. Using data collected from Caltrans’ Pavement Condition Reporting Software, performance models were developed based on dependent (distress) variables: alligator cracking, transverse cracking, longitudinal cracking, and International Roughness Index (IRI). And independent (explanatory) variables: age, traffic in the form of equivalent single axle load (ESAL), thickness of hot mix asphalt (HMA), thickness of Portland Cement Concrete (PCC), and cumulative traffic in the form of cumulative ESAL. Prediction models were then analyzed for preciseness and sensitivity to the variables included in each model.