Age problems

Most exptl smokeless proplnts based upon the high-energy NF compds have been plagued with stability and ageing problems which results in poor shelf-life. Additionally, the cost projections on some of the ingredients results in an unreasonably high cost propint... 

The population module (POP) calculates the population development for the EU29 countries with one-year age cohorts, i.e., the ageing problem is considered. 

The different types of word problems are divided into categories, in case you re only looking for help with age problems or in case you re only interested in interest problems. Most of the examples have a firm basis in reality, but a few are off the wall, just because you need to have a good sense of humor when dealing with math word problems. 

This problem is more like the word problems that most people remember from their high school years. The problem almost seems like double-speak when you first read it. I hate to give too much away right here, because I cover age problems in great detail in Chapter 15, but let this be a tickler— something to get you all enthused about doing more age problems. 

In this chapter, I acquaint you with techniques and procedures to use when tackling word problems involving the ages of one, two, or more people. When broken down into their component parts, age problems seem much less intimidating. Here you see how to deal with aging — well, ages of people after a certain amount of time. I hope you ll see the humor in the cartoon, too. 

Traditional age word problems use algebraic expressions to write comparisons such as twice the age of or four years older than and then solve for one or more person s age. You ll see lots of parentheses in the equations that are first written so that the meaning is clearly defined and the people s ages are clearly identified. Age problems can get pretty wordy and confusing, so you want to be sure that you ve written something to parallel the wording. 

Age problems get even more exciting when you get out your crystal ball and make predictions about the future or look back in a photo album to reminisce about the past. The equations used to solve age problems about the future and past get more complicated because the same amount of time has to be added to or subtracted from each variable expression. 

Some age problems also use comparisons where one person is twice as old or four times as old in a number of years. 

One more age problem to consider mixes in a little number sense with ages now and in the past. 

The major problem in any simulated test is that of shortening the life span of the part. If a part is expected to last several years, an increase in operating temperature may introduce other aging problems than those experienced by operating at standard temperature. Similar considerations need to be applied to other variable factors such as load, vibrations, or concentration of chemicals. 

Sample Preparation. The bentonite powder obtained from Fisher Scientific Company was dissolved in doubly distilled and filtered water to make a stock solution with C 3.65 x 10 g/g. This stock solution was further diluted to the concentrations listed in Table L All measurements were made within 10 days of sample preparation in order to avoid possible aging problems. 

I m not talidng about fun you can have at an amusement park, but CRE fun. Now that we have an understanding on how to solve for the exit concentrations of multiple reactions in a CSTR and how to plot the species concentration down the length of a PER or PER, we can address one of the most important and fun areas of chemical reaction engineering. This area, discussed in Section 6.1, is learning how to maximize the desired product and minimize the undesired product. It is this area that can make or break a chemical process financially. It is also an area that requires creativity in designing the reactor schemes and feed conditions that will maximize profits. Here you can mix and match reactors, feed steams, and side streams as well as vary the ratios of feed concentration in order to maximize or minimize the selectivity of a particular species. Problems of this type are what I call digital-age problems - because... 

Unfortunately there is an aging problem for PTMSP, resulting in deterioration of its transport properties with time. As shown in Figure 9.16, permeability decreased by one order of magnimde during the first 3 months, whereupon permeability stabilized. Selectivity remained stable during this period. But even the aged PTMSP is still a viable alternative to mbbery polymers for heavy hydrocarbon removal. 

If the components are not miscible in the solid and the liquid states, their DSC peaks remain unchanged. This allows to identify components of the drug product, to follow aging problems with polymorphism and in favourable cases to quantify the drug substance and the excipients.f ° ... 

Our approach to the color-variable LEDs presented here has a number of important advantages (1) The two redox polymers modify the charge-inj ection properties of the polymer/metal interfaces, allowing the use of high-workfunction metals as electrodes. This potentially reduces the aging problems associated with conventional polymer LEDs, which must use reactive low-workfunction metals to... 

One important function of the elaboration knowledge and its related mental model of the situation is to preserve the order expressed in the relationship from its first manifestation to the second. Consider again the age problem introduced above. The two things in this problem are readily identifiable as Mary and her mother. Their associated measurable properties are ages in years. The relationship of interest is that Mary s age is one-third of her mother s age. The importance of the mental model should be evident here. Without an adequate model, the solver might be tempted to apply a formulaic approach that depends on a sequential parsing of the problem, expecting the two statements of the relationship to maintain their order. In fact, as this simple problem illustrates, the order is often disrupted. In this problem, the initial statement is Mary-related to-mother. In the final statement, we... 

A defining characteristic of Restate problems is that one answer to the question posed in the problem is explicitly stated. For the age problem, the question is How old is Mary We already know from the problem statement that she is one-third as old as her mother. But this is not the desired form of response. An individual solving this problem is expected to know from previous experience that the solution will be expressed in years, even though an explicit question about years is not stated. 

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