Research studies, experimental designs

Using experimental design such as Surface Response Method optimises the product formulation. This method is more satisfactory and effective than other methods such as classical one-at-a-time or mathematical methods because it can study many variables simultaneously with a low number of observations, saving time and costs [6]. Hence in this research, statistical experimental design or mixture design is used in this work in order to optimise the MUF resin formulation. 

Intensive instrumental and analytical methods research performed during the 1970 s has clearly contributed to the confidence with which current research results are reported. Examination of recent literature shows that research protocols have departed from simplistic single element studies and have incorporated more realistic experimental designs that include multi-elemental determinations. 

The number of levels of any one factor which should be Included in the experimental design will depend largely on the following considerations 1) the research objectives (Is this factor of primary Interest in this research ), 2) the degree of certainty attached to current knowledge of the effects of the factor, and 3) the degree of probability that this factor interacts with other factors, which are definitely of primary interest, to determine the levels of the functional property (or properties) to be studied. Setting the level of an Important causative factor at an arbitrary point(s) could seriously bias results of analysis of the experimental data. 

In setting the number of levels to be studied of any one variable factor, the type of effects which it is likely to have on the functional properties to be studied is very important. If its effects are known to be linear and that factor is of secondary Importance to the researcher, then two levels (one at each end of some practical range of levels) may be sufficient. If, on the other hand, it is known that the effects of this factor are curvilinear and/or discontinuous at some point, then at least three levels should be included in the experimental design. If the Interaction of a factor with other factors is known to be significant, then this too could be sufficient reason to Include more than two levels of that factor in the design. 

Shortly after Ochoa s studies, Sam Weiss began a search for a DNA-directed RNA polymerase. His experimental design was influenced by the theory that RNA must be made on a DNA template if it is to carry the genetic message. He was also influenced by Komberg s discovery that DNA synthesis required nucleoside triphosphates for substrates rather than nucleoside diphosphates. With crude liver extracts, Weiss was able to demonstrate a capacity for RNA synthesis that was severely inhibited by DNase. Weiss s results touched off systematic investigations of RNA metabolism in many laboratories. A continuous expansion of research effort from that time on has yielded a wealth of understanding about the transcription process and related aspects of RNA metabolism. 

The reasonable agreement between the Kd values from our study (2045 mL/g) and Cantrell s work (2600 mL/g) suggests that both studies similarly accounted for the effects of calcium competition in the experimental design. Also, the ability of a single Kd to describe data from several column durations (10 to 60 days) indicates that the equilibrium assumption is reasonable. However, the limited number of applicable studies suggests that more research is needed to confirm these conclusions. 

As we have shown earlier, survey studies and studies of clinical samples have provided a large body of evidence relating inadequate or disturbed sleep to various measures of functioning. Very few studies, however, have employed experimental designs to study consequences of inadequate or restricted sleep. Parents are often reluctant for their children to lose sleep or to stay overnight in a laboratory. In addition, preparing laboratory and staff for the needs of children adds another layer of complexity to laboratory studies. The few experimental studies have provided mixed results and much more research is required. New evidence that school-age children can comply with imposed sleep schedules at home for days and weeks may facilitate additional studies (137). 

Experimental design and analysis have become essential because of the greater detail in modem biological theories and the complexities in treatments of disease. The clinician is usually interested in small, but biologically important, treatment effects that can be obscured by uncontrolled natural variation and bias in non-rigorous studies. This places well-performed clinical trials at the very center of clinical research today (pp. 9-10). 

There are two components to evidence-based medicine and two related sets of responsibilities. The first component is clinical research. Clinical research is a scientific endeavor that provides evidence concerning potential therapeutic interventions. This book has focused on one particular therapeutic intervention, drug therapy. Once clinical trials have been conducted, the evidence obtained is published in clinical communications in journals. Everyone involved in clinical research has the responsibility to provide the best possible evidence in this manner. As noted throughout the book, this includes all aspects of clinical research study design, experimental methodology and clinical operations, analysis and interpretation, and also accurate and complete representation of study findings in clinical communications as discussed in Section 13.6. 

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