Track correlation

The number of cycles of disk rotation required to initiate the wear track correlated positively with the weight percent of the siloxane modifier in the epoxy. However, the initiation times for the ATBN- and CTBN-modified epoxies showed no significant correlation with the percentage of the incorporated modifier. The initiation of the wear track is assumed to result from the fatigue of the epoxy hence initiation time is related to the surface stresses. Because the surface stresses are inversely related to the elastic modulus as predicted by the Hertzian elastic contact theory 52), the initiation time data at ION load were compared to the elastic moduli of the materials in Fig. 16. The initiation times for the siloxane-modified epoxies were negatively correlated with their elastic moduli while samples modified with ATBN and CTBN showed positive correlations with their moduli. At lower loads the initiation times for the siloxane-modified epoxies increased. The effect of load on the CTBN- and ATBN-modified epoxies was too erratic to show any significant trends. 

Anson, 1987 Sheridan et al., 1987) and confirmation of open-loop primary movements (Sittig et al., 1985 Sheridan et al., 1987). In smooth tracking, correlation/cross-spectral analysis between the EMG and limb position has been used to study limb dynamics (Neilson, 1972 Barr et al., 1988). 

Correlation, or track correlation, is the process of combining one track with another track. Only one track retains its track number, and the other is dropped. This is in reference to radar tracking from one or more tracking systems watching an incoming enemy system of some type. 

L. A. Horve, The Correlation of Rotary Shaft Lip Seal Service Reliability and Pumping Ability to Wear Track Roughness and Microasperity Formation. S.A.E. Paper 910530 (1991). 

Nevertheless, these correlations are very practical tools for tracking unit performance and for troubleshooting. They are also important in process design and catalyst research. 

FIGURE 26.38 Correlation and regression coefficients between road test ratings obtained on three different wet road test tracks and laboratory ratings obtained on a wet Alumina 60 laboratory surface as function of... 

FIGURE 26.40 Correlation coefficient between road test ratings on a wet concrete track and laboratory measurements on a wet blunt Alumina 180 disk. Left as function of log a- v and right as function of log a-rv and log V. 

FIGURE 26.42 Comparison of the correlation coefficients between laboratory side force measurements with the six compounds of Table 26.2 on wet, blunt Alumina 180 and a concrete road test track as function of log ajv and log v (left) with function of temperature and log v (right). 

An update of a previous study (Axelson et al. 1978), Axelson (1986) evaluated an expanded cohort of 1,424 men (levels of trichloroethylene exposure inferred from measured urinary metabolite concentrations) and found a significant increase in incidences of bladder cancer and lymphomas, and a lower than expected incidence of total cancer mortality. A further update of this work (Axelson et al. 1994) expanded the cohort to include 249 women, tracking cancer morbidity over 30 years, and found no correlation between exposure concentration or exposure time and cancer incidence at any site. The highest standardized incidence ratio noted in this study was 1.56 (95% Cl of 0.51-3.64) for 5 cases of non-Hodgkin s lymphoma observed in men. Although four of these cases occurred in persons exposed for at least 2 years, and 3 cases had a latency of 10 years or more, urinary levels of TCA showed that 4 of the 5 cases were exposed to the lowest levels of trichloroethylene (urinary levels of TCA 0-49 mg/L). The study authors mentioned that a urinary TCA level below 50 mg/L corresponds to a trichloroethylene exposure concentration of about 20 ppm. The study authors concluded that "this study provides no evidence that trichloroethylene is a human carcinogen, i.e., when the exposure is as low as for this study population."... 

For programs where the primary assay is a binding type assay, it is important to continue to evaluate the functional response of newly synthesized compounds. Changes in functional potency should correlate with changes in binding potency. Other parameters that may need to be tracked are efficacy and agonism vs antagonism. 

The major drawback to using the Florida study to support the correlation between indoor and soil measurements was that the indoor measurements were obtained from 3-day closed-house charcoal measurements, and soil radon was obtained from 1-month alpha track measurements buried 1 ft beneath the soil surface. Comparisons of charcoal and alpha track data are generally not recommended since they are quite different measurement techniques, and represent radon levels over different time periods. However, the study was subjected to numerous quality control checks including deployment of alpha track detectors in 10% of the houses to obtain a check on indoor air measurements made by charcoal canisters. In spite of the measurement drawbacks, the study indicates that soil radon measurements taken alone are not a dependable predictor of potential indoor radon concentration. 

One study has reported effects on neurobehavioral function in lead-exposed workers at mean PbB levels of 50 pg/dL (Williamson and Teo 1986). Neurobehavioral function was measured using tests that are based on information processing theory in 59 lead workers and 59 controls matched for age, type of job, time on the job, education level, smoking history, and alcohol consumption. Statistically significant decreases in the lead-exposed workers were seen for critical flicker fusion reaction, simple reaction time, tracking speeds, hand steadiness tests, and sensory store memory. Sensory store memory speed showed a low but statistically significant correlation with PbB concentrations. Measurements of neurobehavioral function seemed well chosen, and repeated measures with associated appropriate statistics were used. 

In order to assess the accuracy of the present method, we compared it with two other methods. One was the Track Etch detector manufactured by the Terradex Corp. (type SF). Simultaneous measurements with our detectors and the Terradex detectors in 207 locations were made over 10 months. The correlation coefficient between radon concentrations derived from these methods was 0.875, but the mean value by the Terradex method was about twice that by our detectors. The other method used was the passive integrated detector using activated charcoal which is in a canister (Iwata, 1986). After 24 hour exposure, the amount of radon absorbed in the charcoal was measured with Nal (Tl) scintillation counter. The method was calibrated with the grab sampling method using activated charcoal in the coolant and cross-calibrated with other methods. Measurements for comparison with the bare track detector were made in 57 indoor locations. The correlation coefficient between the results by the two methods was 0.323. In the case of comparisons in five locations where frequent measurements with the charcoal method were made or where the radon concentration was approximately constant, the correlation coefficient was 0.996 and mean value by the charcoal method was higher by only 12% than that by the present method. 

On other hand, we found a good correlation between the results by the present method and those by the Terradex detector. However, the mean value obtained by the Terradex detector were about twice those by the present method. The reasons for this significant difference are unknown and may be due to errors in the calibration experiments and in the conditions during the measurements. In the calibration experiments the effect of existence of thoron in the chambers could be one of the reasons. As regards the condition in the measurements, methods for subtraction of background tracks and deposition of dust onto the bare detector could be candidates. However, we do not have enough data to determine the reasons for some of this difference. 

In a formal sense, a track is generated by correlated energy loss events along the direction of the momentum of the penetrating particle. Figure 3.2 shows the formation of a track according to Mott in the second-order perturbation theory... 

Of course, the role of the artificially introduced stochastics for mimicking the effect of all eddies in a RANS-based particle tracking is much more pronounced than that for mimicking the effect of just the SGS eddies in a LES-based tracking procedure. In addition, the random variations may suffer from lacking the spatial or temporal correlations the turbulent fluctuations exhibit in real life. In RANS-based simulations, these correlations are not contained in the steady spatial distributions of k and e and (if applicable) the Reynolds stresses from which a typical turbulent time scale such as k/s may be derived. One may try and cure the problem of missing the temporal coherence in the velocity fluctuations by picking a new random value for the fluid s velocity only after a certain period of time has lapsed. 

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