Period measurement

Although the instruments that functioned according to equation 6.2 were very useful, it soon became obvious that for the desired accuracy their area of application was typically limited to AF 0.02 F. Even at a relative frequency change of (F - F J / F 2 %, errors of around 2 % occurred in the coating thickness measurement so that the usable service life of the coating in the case of a 6-MFIz monitor crystal was about 120 kFIz. 

The period measurement (measurement of the oscillation duration) vi/as the result of the introduction of digital time measurement and the discovery of the proportionality of crystal thickness Dq and oscillation duration Tq. The necessary precision of thickness measurement permits application of equation 6.3 up to about AF 0.05 Fq. 

In period measurement a second crystal oscillator is essentially used as a reference oscillator that is not coated and usually oscillates at a much higher frequency than the monitor crystal. The reference oscillator generates small precision time intervals, with which the oscillation duration of the monitor crystal is determined. This is done by means of two pulse counters the first counts a fixed number of monitor oscillations m. The second is started simultaneously with the first and counts the oscillations of the reference crystal during m oscillations of the monitor crystal. Because the reference frequency F,. is known and stable, the time for m monitor oscillations can be determined accurately to 2/F,.. The monitor oscillation period is then 

For low coating rates, small densities of the coating material and fast measurements (that require short counting times), it is important to have a reference oscillator with a high frequency. All of this requires great time precision so that the small coating-related frequency shifts can be resolved. If the frequency shift of the monitor crystal decreases between two 

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In case of mixed systems the procedure must be varied and it would be restricted to the special film systems of interest, of course. Mixed systems would be used by inspection companies and industrial users who normally do not dispose of the equipment for measurements as mentioned above. In these cases instead of a round robin test only periodical measurements of the properties of these mixed film systems by an independent third party institution can be used for film classification and continuous surveillance. 

If your facility does not have periodic measurements of stormwater releases of the chemical, but has submitted chemical-specific monitoring data in permit applications, then these data must be used to calculate the percent contribution from stormwater. Rates of flow can be estimated by multiplying the annual amount of rainfall by the land area of the facility and then multiplying that figure by the runoff coefficient. The runoff coefficient represents the fraction of rainfall that does not infiltrate into the ground but runs off as stormwater. The runoff coefficient is directly related to how the land in the drainage area is used. (See table below.)... 

Induction period measurements can also be used to determine interfacial tensions. To validate the values inferred, however, it is necessary to compare the results with an independent source. Hurley etal. (1995) achieved this for Cyanazine using a dynamic contact angle analyser (Calm DCA312). Solid-liquid interfacial tensions estimated from contact angle measurements were in the range 5-12 mJ/m which showed closest agreement with values (4—20mJ/m ) obtained from the log-log plots of induction time versus supersaturation based on the assumption of — tg. 

Audit findings or scores are useful periodic measures of improvement in PSM and ESH management. Improvement in performance between audits is generally easy to spot. Audits may not be conducted annually at each facility however, if a sufficient sample of facilities is audited each year it can provide a useful indicator of overall change across the company. Of course, the audit results are most relevant to the individual facility managers who can develop action plans for improvement based on the results. 

Hazard assessment findings are similar to audits, in that they are periodic measures. Hazard assessments might include Hazard and Operability (HA-ZOP) studies, What-If/Checklists, Fault Tree Analyses, or other techniques. The results of these studies will indicate what types of hazards exist and whether or not these hazards are sufficiently controlled. 

Figure 4. Effect of hyperosmolality on lysosomal enzyme release from rabbit neutrophils. Cells were preincubated 10 min at 37 C in either regular HEPES buffer at 320 mosmol/kg ( ) or in HEPES buffer with 0.3-M sucrose at 680 mosmol/kg ( ), 5 Mg/mL cyto-chalasin B was added, cells were stimulated with FMLP, and p-glucuronidase was released into the medium during a 6-min period measured.

Heuberger et al. [272] and an Israeli group [271] have, independently from each other and at nearly the same period, measured the hyperfine splitting and the isomer... 

Measure blood glucose levels at baseline and every 3 months to assess for glucose intolerance and insulin resistance. Periodic measurement of glycosylated hemoglobin (HbAlc) also may be useful.34... 

Information on the excretion of americium after dermal exposure in humans or animals is extremely limited. Some qualitative information is available from an accidental exposure in which a worker received facial wounds from projectile debris and nitric acid during an explosion of a vessel containing 241 Am (McMurray 1983). The subject also inhaled 241Am released to the air as dust and nitric acid aerosols, which was evident from external chest measurements of internal radioactivity thus, excretion estimates reflect combined inhalation, dermal, and wound penetration exposures (Palmer et al. 1983). Measurements of cumulative fecal and urinary excretion of241 Am during the first years after the accident, and periodic measurements made from day 10 to 11 years post accident indicated a fecal urine excretion ratio of approximately 0.2-0.3, although the ratio was approximately 1 on day 3 post accident (Breitenstein and... 

All is not what it seems, however, because most binary stars have a very faint neighbour and so both the red- and blue-shifted lines are not observed and the spectroscopic motion of just the bright star is enough to make the period measurement. The faint binary partner will pass in front of the bright star during the period of rotation if the plane of the binary orbit is along the line of sight from the Earth. 

Method validation provides information concerning the method s performance capabilities and limitations, when applied under routine circumstances and when it is within statistical control, and can be used to set the QC limits. The warning and action limits are commonly set at twice and three times the within-laboratory reproducibility, respectively. When the method is used on a regular basis, periodic measurement of QC samples and the plotting of these data on QC charts is required to ensure that the method is still within statistical control. The frequency of QC checks should not normally be set at less than 5% of the sample throughput. When the method is new, it may be set much higher. Quality control charts are discussed in Chapter 6. 

Regular, periodic measurement of plasma HIV RNA levels and CD4 cell counts is necessary to determine the risk of disease progression in an HIV-infected individual and to determine when to initiate or modify antiretroviral treatment regimens. 

It is essential to ensure that employees are not exposed to toxic materials at levels above or for durations beyond those permitted by TLV s or the equivalent. It is thus necessary to ensure by periodic measurement that atmospheric levels of toxic materials throughout the work shift do not exceed the permitted levels. Measurement of atmospheric toxic exposures has been discussed in Chapter 11. The frequency of this air sampling depends on the potential for exposure and injury. Where the hazard is relatively low and actions have been taken to control it, occasional checks by a knowledgeable but not necessarily professional person are desirable to ensure that the control is effective. Where there is a potential for serious hazard, for example, where high-hazard materials are handled in quantity,... 

Periodical measurement of well known odours is advisable. This helps in controlling the general performance of olfactometer and observers. 

At the next sampling period, measure the controlled variable to get a new value of x and repeat the steps above. 

We start the reaction, and follow its course, e.g. by periodically measuring the concentration of reagents, and then plot the function ... 

The asymptotic observer was tested in an experimental 1 m upflow anaerobic fixed bed reactor pilot plant used for the treatment of industrial wine distillery vinasses obtained from local distilleries in the Narbonne area (France) (see Figure 26). These experimental runs were carried out over a 35 day period. Measurements of the dilution rate as well as the and S2 concentrations and the partial CO2 pressure were performed on-line (see Figures 27 to 30). The measurements of S J, and were obtained from off-line data and... 

The results obtained with the model for the mammalian circadian clock provide cues for circadian-rhythm-related sleep disorders in humans [117]. Thus permanent phase shifts in LD conditions could account for (a) the familial advanced sleep phase syndrome (FASPS) associated with PER hypopho-sphorylation [118, 119] and (b) the delayed sleep phase syndrome, which is also related to PER [120]. People affected by FASPS fall asleep around 7 30 p.m. and awake around 4 30 a.m. The duration of sleep is thus normal, but the phase is advanced by several hours. Moreover, the autonomous period measured for circadian rhythms in constant conditions is shorter [121]. The model shows that a decrease in the activity of the kinase responsible for PER phosphorylation is indeed accompanied by a reduction of the circadian period in continuous darkness and by a phase advance upon entrainment of the rhythm by the LD cycle [114]. 

After the addition of the seed crystals the relative solution concentration was periodically measured. In Figure 3 the changes of L-threonine concentration in the solution were compared for four experimental runs with different initial supersaturations. Here the relative concentration is defined as the ratio of L-threonine to the total enantiomers. For the case of lower initial supersaturations... 

Monitor response to all diabetic therapies by periodic measurements of FPG and HbA-ic levels. During initial dose titration, fasting glucose can be used to determine... 

Hepatotoxicity Hepatotoxicity with elevated serum alkaline phosphatase and bilirubin may occur primarily in allograft recipients. Periodically measure serum transaminases, alkaline phosphatase and bilirubin for early detection of hepatotoxicity. 

Activity ratios are a measure of how effectively a firm manages its assets. There are two inventory/turnover ratios in common use today. The inventory/sales ratio is found by dividing the inventory by the sales. Another method is to divide the cost of sales by inventory. The average collection period measures the number of days that customers invoices remain unpaid. Fixed assets and total assets turnover indicate how well the fixed and total assets of the firm are being used. 

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