Patterns, cyclical

World trade in coal totaled 576 million tons (524 million tonnes) in 1998, of which 523 million tons (476 million tonnes) shipped in oceangoing vessels. Coal shipments use the same dry bulk vessels that transport other bulk commodities, such as iron ore and bauxite, so vessel rates for coal shipments arc hostage to wider market forces. However, the cyclic pattern observable in vessel rates disguises the long-term trend in which rates have varied little in nominal terms. For example, spot vessel coal rates in the 1998-1999 time period were about the same as in the mid-1980s, varying between 5 and 10 per ton. 

There is a cyclic variation in the amount of sulphate found in rust formed on steel exposed at different times of the year (Fig. 3.3), and the amount depends on the month of the year rather than on the period of exposure, at least for periods of up to two years. Consequently, the month of exposure will have an important influence on the corrosion rate up to a year or so (see Table 3.2). In one test, specimens exposed for two months from September corroded at 0-035 mm/y compared with 0.0136 mm/y for specimens exposed from May, and the amount of rust formed on steel follows this cyclic pattern over periods of up to two years and possibly for... 

A form of corrosion resulting in the transgranular cracking of a metal in an corrosive environment under a cyclical pattern of stress. 

A characteristic of the pump was the appearance of a cyclic pattern in the rate of discharge. The resulting fluctuations were responsible for a wastage of energy, not only... 

The rate and depth of breathing are perfectly adjusted to meet the metabolic needs of the tissues and to maintain a P02 of 100 mmHg, a PC02 of 40 mmHg, and a pH of 7.4 in the arterial blood. Breathing is initiated spontaneously by the central nervous system and occurs in a continuous cyclical pattern of inspiration and expiration. The three major components of the regulatory system for ventilation are ... 

As shown in Table 3.21, the stabilization corresponding to Fig. 3.46(a) (36.8 kcal mol-1) is nearly twice that of benzene (20.4 kcal mol-1), but the complementary interaction corresponding to Fig. 3.46(b) is essentially switched off (less than 1 kcal mol-1). Thus, borazine has a strong mono-directional cyclic pattern of conjugations that is quite unlike that of benzene. 

The final pair of methods for reduction of dimensionality which will be tackled in this chapter are Fourier analysis and the life table analysis. Fourier analysis seeks to identify cyclic patterns in data and then either analyze the patterns or the residuals after the patterns are taken out. Life table analysis techniques are directed to identifying and quantitating the time course of risks (such as death, or the occurrence of tumors). 

The top panel in Figure 10.3 shows the issues as a function of measurement number. The bottom range chart shows that the short-term variability of the issues process is stable and in statistical control. The x-bar chart shows that the issues process mean is stable and in statistical control, with one exception at subgroup 19. A cyclical pattern appears to be present in the x-bar chart, but the structure is not as well defined as it is for the clearings data. 

Initial inspection of Figure 10.1 showed what appears to be a cyclical pattern in the clearings and issues. This was confirmed by the statistical process control charts in Figures 10.2-10.4. The broad peaks and valleys in Figure 10.1 seem to repeat every 20 to 25 days. At first, this seemed to be a strange number of days for a cycle - a monthly cycle of 30 or 31 days would have made more sense to some of us. However, the student was quick to point out that the average business month has between 21 and 22 days (365.25 calendar days per year) x (5 business days per week) / (7 calendar days per week) = 260.89 business days per year which, when divided by 12 months, is 21.75 or approximately 22 business days per month. 

The ozone layer seems to follow some cyclic pattern that may affect the size of the thin layer over time. 

Figure 9) The magnitude of the systematic error contribution changes continuously with time, but it follows a definite cyclic pattern that repeats itself periodically. (This case is simulated here as a sine wave.)... 

We used the cumulative number of drugs with NMEs approved and launched in Taiwan to measure pharmaceutical innovations. The annual number of NMEs introduced into Taiwan between 1985 and 2002 followed cyclic patterns (Fig. 13.1). In 1985, 95 NMEs were introduced in this market. This number decreased to 52 and 49 in the next two years, but increased subsequently. In 1995 only 15 NMEs were introduced, possibly reflecting delays in approvals caused by the transition from the then-existing health care financing system to national health insurance in Taiwan in that year. ... 

These individuals have areas of increased bone resorption and other areas of abnormal new bone formation. The abnormal bone formation can result in pain, deformity, and fracture of affected bones. The bisphospho-nates and calcitonin are most commonly used in the treatment of this disease. Long-term continuous use of bisphosphonates can be associated with the induction of osteomalacia through a direct impairment of new bone formation. Therefore, the bisphosphonates are given in a cyclic pattern to treat Paget s disease. 

Recurrent endogenous depression with a cyclic pattern is controlled by either lithium or imipramine, both of which are superior to placebo. 

Acute endogenous depression is not generally considered to be an indication for treatment with lithium. Alcohol and substance abuse have a high association with bipolar illness. However, recurrent endogenous depressions with a cyclic pattern are controlled by either lithium or imipramine, both of which are superior to a placebo. 

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