Laboratory Report Analysis

 

Comparing and Contrasting Two Laboratory Reports on

Studying the Efficiency of Centrifugal Pumps

 

 

Klement Miraj

 

06/21/2020

English 21007

Writing for Engineers

 

 

 

 

 

 

 

 

INTRODUCTION

This analysis compares two different laboratory reports that examine the efficiency of a centrifugal pump. The first report is titled Centrifugal Pumps and authored by Oseloka Chira, Karla Muñoz, Yash Patel, and Jacob Weber. [1] The report was conducted in a Unit Operations 2 course that was taught by Professor Rumschitzki. This article is from the department of Chemical Engineering at The City College of New York. The second laboratory report is also titled Centrifugal Pumps. [2] It is authored by Carlos Tavarez, Mark Hryhorovych, Olivier Pierre, and Mohammed Farroque. The second report was conducted in a Transport Operations class that was taught by Professor Morris. This report is from the department of Chemical Engineering at The City College of New York. Since both reports have the same title it is easier to refer to the first report as the “Rum Report” and the second report as the “Mor Report”. This analysis will compare and contrast both reports by determining the effectiveness of each subunit to convey a message to the reader. The subunits being analyzed are the titles, abstracts, introductions, materials and methods, results and discussions, conclusion, and references. The guidelines followed in this analysis will be based on Chapter 19 of Technical Communication, 11^th Edition by Mike Markel. [3]

Comparing Titles

          According to Markel, an informative title helps scientists and engineers save time by using abstracting and indexing services to locate the research most relevant for their needs. [3] In both reports mentioned above the titles are Centrifugal pumps. These titles do not follow Markel’s guidelines and it is not informative enough to enable the readers to decide what the report is about. Having a catchy title will attract a reader to the report as well as notify of what was studied in the report. A better title might be “How the Efficiency in a Centrifugal Pump is Impacted by Varying the RPM and Volumetric Flow Rate.”

Comparing Abstracts

Regarding abstracts, Markel writes: “Readers of abstracts are most interested in what questions motivated your study (introduction), what answers you discovered (results), and what implications your findings have (conclusions)”. [3] Starting from the beginning both abstracts do not mention the interests that motivated them. This is common for reports that are assigned by professors because the students see the work as an assignment and not as a research paper. In the case of the Rum Report the abstract consisted of a clear summary of the experiment and of the most important data found. The Mor Report has a summary of the experiment and results, but it is written incorrectly by using a first-person perspective and using words such as we and ours. Both reports also lack an introductory sentence in the abstract to show the readers what the study is about.

Comparing Introductions

          Markel states that the introduction “…should include a concise review of previous research relevant to your study and should describe how your study extends the knowledge in your field or overcomes a weakness in previous studies”. [3] Starting off with the Rum Report it is noted that the introduction is very brief. It fails to mention previous experiments that have been done before and how it relates to the experiment being done in the report. The report explains the device well and uses principles of how a centrifugal pump works. In the Mor Report the introduction is more elaborate by including how pumps have been used as well as the aim of the report so the reader knows what is to come. The report also included visuals of how the pump works and the different compartments that make up the centrifugal pump. A schematic of the experimental setup is also included in the introduction which is unusual. A proper place for an experimental setup would be in the methods region. Neither report accomplishes Markel’s essential feature of an introduction. However, this lab report is written to explore the fundamental operating principles of a pump, rather than to show a new finding or study that could advance scientific knowledge of the device.

Along with an introduction, both reports contain a Theoretical Background section. These sections expand upon the information provided in the introduction, explaining the relevant physics and mathematical equations behind the device and the experiments. Most importantly, for the Rum Report the section shows a schematic of the experimental setup, and a cross-section of an example of a centrifugal pump. This is something that could also be included in a Materials and Methods section, as it shows how the experiment was set up, and from which gauges and meters the measurements were taken. Both reports also importantly show an equation for efficiency as it is defined for the centrifugal pump. This is essential to the entire report, as the aim is to study efficiency across a variety of operating conditions. Both reports show nearly the same information, with The Rum Report giving some more equations than The Mor Report.

Comparing Materials and Methods

          As previously mentioned, rather than a Materials and Methods section both reports use a Theoretical Background section as well as a Procedure section. Both reports appear to have a 10-step procedure that seems to be given to students who were assigned this experiment in class. These 10 steps give the exact instructions to follow to set up and run the experiment. In the procedure it does not explain the exact make and model of the pump, or the make and model of the motor that drives the pump. This information is very crucial because if another reader wants to try the same experiment it will be difficult because the name and model number of the pump are missing. To the outside reader, who only has seen a schematic of the system, this Procedure section is not very clear for both reports. The Materials and Methods section is meant to “Describe your methods in enough detail that another researcher could perform the same experiment using the same materials and methods”. [3] Unfortunately, both reports fail to have enough details for another researcher to perform the same experiment.

Comparing Results and Discussions

          As both reports were written on the same laboratory experiment, the Results and Discussions are nearly the same. There are differences among their experimental values which will always be the case for a reproduced experiment. A notable result is that using the same centrifugal pump experimental setup, the Mor Report, written in 2016, reports a maximum efficiency of ~50%. In the other hand the Rum Report, written in 2017, reports a maximum efficiency of ~15%. This is a big difference when it comes to efficiencies of pumps. One possible reason for this large decrease in reported efficiency could mean the system experienced wear and tear through a one-year cycle. The other two possibilities may be a possibly a repair between 2016 and 2017, or that there are calculation errors in one or both laboratory reports. This analysis does not cover discrepancies in the reasons behind different results for the same experiment, so will not be discussed. However, these differences are worth noting.

The Mor Report shows two figures in this section but does not properly reference them with a caption. Figures that are not produced by the author should always be referenced correctly to give the owner credit as well as give the reader information in case of more research. The Rum Report shows four figures and does properly reference them with captions. Also, The Mor Report uses different shapes for the different curves on the same plot, while The Rum Report uses different colors. Using different shapes is more appropriate because if someone prints the lab report on a black and white printer, they will still be able to distinguish between different curves. Using different colors would prevent the reader from easily distinguishing which curve is which when printed in black and white.

In the last paragraph of The Rum Report, potential sources of error and areas for improvement are discussed. If a reader wants to do this experiment him/herself, it is important for the writer to include the major sources of error and where improvements could be made. This could allow for a future experimenter to obtain more accurate results with less errors. The final paragraph of the Rum Report also discusses why these results are important, stating that “From these curves, the maximum efficiency of the pump at all conditions could be determined, which would save operating energy and costs”. [1] This important information is not included in the Mor Report.

Comparing Conclusions

According to Markel a conclusion should summarize the main points covered by your report in one or two concise paragraphs. [3] The Mor Report concisely encapsulates what the experiment was about by incorporating a summary.  Important observations and data were also included in the conclusion. In the Rum Report, the conclusion section neatly summarizes the lab report and the fundamental relationships explored without getting into details already discussed in previous sections. It also correctly suggests future studies that could be done to further explore the operating conditions of a centrifugal pump.

Comparing Appendixes

          In the Rum Report appendixes, it is noted that there are two different tables that show raw data that was used to create the figures in the Results and Discussion section. A third table is also included that shows sample calculations and efficiencies reached by the centrifugal pump. In the Mor Report the appendixes show all the information that was collected by the experiment. It demonstrates that there were two runs performed and an average of the two was calculated. In both cases Markel’s instructions were followed which states that it is the appropriate place for information that readers do not need to understand the body of your lab report. [3]

Comparing References

            When comparing both reports it is observed that there is a difference in the style of reference citation. In the Mor Report citations are reported on the footer of the page that the citation appears on. The Rum Report reports citations by putting numbers in brackets in the end of the sentence which corresponds to the reference section number at the end of the report. The Rum Report also follows a chronological cited reference meaning that the smaller number in the bracket corresponds towards the beginning of the report and follows bigger numbers in the end of the report.

CONCLUSION

          Overall, both reports have a different writing style and do a great job at explaining what a centrifugal pump does and how to calculate certain aspects. First thing that is noted is that the Mor Report has many more grammatical errors then the Rum Report. The Rum Report appears to have a more thorough understanding of the subject by being longer in length. Also, additional equations, figures and tables were provided to have a better understanding of the results. However, the Mor Report has a better title page with graphics and logos and uses a table of contents which the Rum Report skips.

In Addition, there is a large discrepancy in the reported results between the two reports. The Mor Report states an efficiency of 50 % for the centrifugal pump while the Rum Report states an efficiency of 15%. Since this is a big difference in the results while using the same equipment more experimentation is needed to find out where the errors were made and how to avoid them in the future. In this case the Rum Report is found to be more effective as a laboratory report on studying the efficiency of a centrifugal pump. This is due to its more error free writing and a more complete analysis and explanation.

 

REFERENCES

1. Chira, O., Munoz, K., Patel, Y., & Weber, J. (2017). Centrifugal Pumps(pp. 1-13, Tech.). New York, NY: Department of Chemical Engineering, The City College of New York.
2. Tavarez, C., Hryhorovych, M., Pierre, O., & Farroque, M. (2016). Centrifugal Pumps(pp. 1-11, Rep.). New York, NY: Department of Chemical Engineering, The City College of New York.
3. Markel, M. (2014). Chapter 19: Writing Lab Reports. In Technical Communication(11th ed., p. 515 – 532). Boston: Bedford/St. Martin’s.