Analyzing Data

Scientists often express numbers in scientific notation and solve problems using dimensional analysis. 

EHEKES Measurements contain uncertainties that affect how a calculated result is presented. 

Most skydivers jump from an altitude of about 4000 m. 

A skydiver s maximum speed is about 190 km/h, but speeds as high as 483 km/h have been achieved. 

The freefall portion of a dive usually lasts more than a minute, while the parachute portion lasts 5-9 minutes. 

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Multivariate statistics is the discipline to analyze data, to elucidate the intrinsic structure within the data, and to reduce the number of variables needed to describe the data. 

There is a temptation when analyzing data to plug numbers into an equation, carry out the calculation, and report the result. This is never a good idea, and you should develop the habit of constantly reviewing and evaluating your data. For example, if analyzing five samples gives an analyte s mean concentration as 0.67 ppm with a standard deviation of 0.64 ppm, then the 95% confidence interval is... 

In this problem you will collect and analyze data in a simulation of the sampling process. Obtain a pack of M M s or other similar candy. Obtain a sample of five candies, and count the number that are red. Report the result of your analysis as % red. Return the candies to the bag, mix thoroughly, and repeat the analysis for a total of 20 determinations. Calculate the mean and standard deviation for your data. Remove all candies, and determine the true % red for the population. Sampling in this exercise should follow binomial statistics. Calculate the expected mean value and expected standard deviation, and compare to your experimental results. 

W. J. Diamond, Practica/ Experimenta/ Designs for Engineers and Scientists, 2nd ed.. Van Nostrand Reinhold, New York, 1989. "This book is for engineers and scientists with Httie or no statistical background who want to learn to design efficient experiments and to analyze data correctiy. .. The emphasis is on practical methods, rather than on statistical theory." The discussion is quite detailed in some areas, eg, experimental designs based on Hadamard matrices, and scanty in others. 

Holzworth and Maga (16) developed a technique for examining the trend in visibility and analyzed data for several California airports. Bakersfield s visibility deteriorated over the period 1948-1957, and Sacramento s visibility decreased over the period 1935-1958. Los Angeles had decreasing visibility from 1932 to 1947, with little change over the period 1948-1959. 

RMDB is supplemented by microfilmed reports containing failure rates/modes and analyzed data. Reports relating to the theory and procedural techniques to obtain and analyze reliability-maintainability data are cataloged, abstracted, microfilmed and computer listed in the R-M Data Summaries. 

Don t collect and analyze data just because it is accessible. Only collect data that will lead to action to improve the product, process, or system... 

Only analyze data with the intention of discovering problems. 

It frequently happens that we plot or analyze data in terms of quantities that are transformed from the raw experimental variables. The discussion of the propagation of error leads us to ask about the distribution of error in the transformed variables. Consider the first-order rate equation as an important example ... 

Alert and alarm limits The microprocessor should include the ability to automatically alert the user to changes in machine, equipment or system condition. Most of the predictive maintenance techniques rely on a change in the operating condition of plant equipment to identify an incipient problem. Therefore, the system should be able to analyze data and report any change in the monitoring parameters that were established as part of the database development. 

This chapter will present examples of testing and their behavior that influence decisions to be made by designers when analyzing data. Testing methods have been prepared and used for over 2,000 years with probably more in the past century that in all the past. Examining and properly applying property test data of plastics is important to designers. 

In computer operations with other kinetic systems, Equation 8 may be used, and all the unique features of the kinetic system may be incorporated into the value of Q which may of course be a very complex expression. This technique is of interest only in that it simplifies the work necessary to analyze data using any specific kinetics for a chemical reaction. The technique requires sectioning the catalyst bed in most cases with normal space velocities, 50-100 sections which require 2-3 min of time on a small computer, appear to be sufficient even when very complex equations are used. 

Mahabadi and O Driscolm considered that segmental motion and center of mass diffusion should be the dominant mechanisms at low conversion. They analyzed data for various polymerizations and proposed that k, J should be dependent on chain length such that the overall rale constant obeys the expression ... 

M.S.A.-WHitby Particle Size. Analyzer Data for Ammonium Nitrate. ... 

The lEP provides the monitoring fi amework to characterize the status and trends of Delta aquatic ecosystems. The lEP strives to provide information on the many factors that affect ecological resorrrces in the Delta. Key near-term goals for the lEP include (1) collecting and analyzing data needed to understand factors controlling the distribution and abundance of selected fish and wildlife resources, (2)... 

Software designed for general or specific use might be useless in the intended application sociologists, mathematicians, clinical researchers, and physicists, just to name a few user categories, all gather and analyze data, to be sure, but each one has particular data structures and hypotheses. Tests must be selected to fit the application. 

These gold exchange reactions are prevented by prior alkylation of this protein thiol. Because of its lower affinity for gold when Cys-34 exists as a disulfide species, gold-to-sulfhydryl and gold-to-total albumin ratios are considered when analyzing data. Albumin with the Cys-34 blocked by alkylation is often used. 

Further progress in understanding membrane instability and nonlocality requires development of microscopic theory and modeling. Analysis of membrane thickness fluctuations derived from molecular dynamics simulations can serve such a purpose. A possible difficulty with such analysis must be mentioned. In a natural environment isolated membranes assume a stressless state. However, MD modeling requires imposition of special boundary conditions corresponding to a stressed state of the membrane (see Refs. 84,87,112). This stress can interfere with the fluctuations of membrane shape and thickness, an effect that must be accounted for in analyzing data extracted from computer experiments. 

FIG. 8 Contour plot of percentage error in the rate constant that results from analyzing data in terms of the constant-composition model, rather than the full diffusion model. The data are for a tip-ITIES separation, d/a = 0.1, with a range of K and values. (Reprinted from Ref. 49. Copyright 1999 American Chemical Society.)... 

Acquiring and Analyzing Data What happens to the volume of the gas as the pressure increases ... 

When scientists perform experiments, they make observations, collect and analyze data, and formulate generalizations about the data. When you work in the laboratory, you should record all your data in a laboratory report. An analysis of data is easier if all data are recorded in an organized, logical manner. Tables and graphs are often used for this purpose. 

It is a pleasure to acknowledge those individuals who helped us indirectly in preparing this book our colleagues Professors L.A. Behie, P.R. Bishnoi, R.A. Heidemann and R.G. Moore and our graduate students who over the years as part of their M.Sc. and Ph.D. thesis have gathered and analyzed data. 

The FDA is in the process of analyzing data to determine whether there is an increased risk of suicidality in adult patients similar to that seen in pediatric patients (see above). Even though the suicidality risk for adults taking antidepressant medications... 

A few years later in 1983, Whittemore and colleagues11 analyzed data on 50,000 former male students who had attended Harvard University between 1916 and 1950. In a 16 to 50 year follow-up, they compared coffee and tea drinking practices of 126 men in the college cohort, who had subsequently died of pancreatic cancer, with those of 504 surviving class-... 

Data analysis should focus on the development or refinement of the conceptual site model by analyzing data on source characteristics, the nature and extent of contamination, the contaminants transport pathways and fate, and the effects on human health and the environment. All field activities, sample management and tracking, and document control and inventory should be well managed and documented to ensure their quality, validity, and consistency. 

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