Guidelines for Engineering-based Projects

All manuscripts published in JEI must be hypothesis-driven research. Hypotheses are a crucial part of the scientific thinking process, and professional scientific endeavors revolve around posing and testing hypotheses. We believe that it is important for students who publish with JEI to practice rigorous scientific thinking. This means that manuscripts that merely introduce an invention, no matter how impressive it is, are not appropriate for JEI. Here are some common examples of unacceptable “hypotheses” relating to engineering projects:

  • I hypothesize that my invention will work
  • I hypothesize that I can build this invention

In this guideline, we will provide some examples of submissions that we received in the past that failed our Pre-Review process because they did not pose a clear hypothesis. We will then describe a few of the best strategies to convert your engineering-based manuscript into a hypothesis-driven one publishable with JEI.


Ex. 1

Developing a Portable, Reusable, and Inexpensive Magnesium-Air Fuel Cell


Global warming is becoming an increasingly bigger problem by the day, and it is important that we work to find alternative sources of electricity. The goal of this project was to build a fuel cell that could generate useful electricity with clean energy sources. This fuel cell uses magnesium, salt water, and oxygen from the atmosphere to generate electricity. The fuel cell, designed to contain nine sub-cells, each have gratings on their sides to let air pass through a carbon cathode-filter on the outside perimeter of each sub-cell. In the middle of the cell is a strip of magnesium. In between the carbon filter and magnesium lies the salt water electrolyte. In the fuel cell, the salt water is soaked up by cotton to prevent water from leaking out of the fuel cell. The magnesium is oxidized by the oxygen, and releases two electrons that generate an electric current. During testing, the fuel cell, with 3 rows of 3 cells in series, generated 4 volts at .75 amperes. This was enough to power an LED light and charge a phone. The magnesium strip inside each sub-cell lasts for approximately 48 hours before generated electricity levels drop to insignificant amounts. This engineering project proved that magnesium-air fuel cells are viable for electricity production, and that this technology can be used in a variety of applications. Possible uses of this fuel cell include electricity in remote locations, immediate electricity for rescue teams, and portable power for hikers, bikers, and campers.

Reasons for Pre-Review failure:

The authors of this manuscript designed and built a portable magnesium-air fuel cell and validated its function with a few tests. However, the manuscript is not structured around a clear hypothesis and experiments to test whether the hypothesis is correct, and therefore is not appropriate for publication in JEI as is. See below for potential ways to convert this manuscript into hypothesis-driven research.

Ex. 2

DyGS: a dynamic gene searching algorithm for cancer detection


Cancer is a lethal disease and ranks as the world’s second most prevalent cause of death. So far, biopsy is the most common method conducted to determine the progression of tumors. However, the traditional technique is deemed too invasive and cannot be used repeatedly. On the other hand, liquid biopsy, also known as blood-sample tests, has become more and more promising. One critical step in liquid biopsy is to create an effective gene panel to cover the maximum number of cancer cases possible. In this study, we used a novel dynamic gene searching algorithm called DyGS (Dynamic Gene Search). As far as we know, this was the first algorithm designed to create a gene panel for each of the 12 cancers that have the highest number of new cases and death rates. Based on this efficient algorithm, gene lists were generated, ranging from 12 to 153 genes with a median of 47 for the 12 cancer types. Notably, many of these genes included in the panel can be targeted by various drugs. Therefore, the gene panels designed by the DyGS algorithm can then be used as actionable drug targets for cancer treatment as well as biomarkers in liquid biopsy to help identify the early stages of cancer.

Reasons for Pre-Review failure

Again, this is very impressive work done by a high school student. The implicit hypothesis of the study is that the algorithm they developed can create gene lists to effectively test for 12 types of cancer. In order to test this hypothesis, the author needs to show that the gene list can accurately predict whether the patient has the particular type of cancer, and/or whether it outperforms other algorithms. However, the authors did not perform an experiment to actually test the validity of their methods, though they suggested why it might be valid by looking closely at the gene list and making sense of the output. Because the authors did not actually test the hypothesis and show the results, it is not appropriate for JEI publication in its current form. If performing an experiment to test the algorithm is not feasible, the author needs to modify the hypothesis. See an example of how this can be done below.

Strategies to convert engineering-based manuscripts

It is often possible to convert an engineering-based manuscript to a hypothesis-driven one by adding a few experiments, and sometimes just by changing the way it is presented. Here are some strategies to convert manuscripts that involve engineering and optimization projects to also include a clear, experimentally tested hypothesis, with examples drawn from past JEI submissions.

1. Use the device or algorithm to address a scientific question

This is the best way to use your invention to write a hypothesis-driven manuscript acceptable for JEI publication. Here are some examples of JEI manuscripts that uses the invention/optimization to pose a question and perform a series of experiments to test the hypothesis using their invention.

Ex. 1

The Effect of Turbine Size on Voltage Production in a Small-Scale Hydropower Generator


The purpose of this experiment was to determine if a larger turbine on a small hydropower generator would produce a greater voltage than a smaller sized turbine. This experiment was conducted in the Salinas river, which flowed from 0.40 m/s to 0.43 m/s during testing, and a sink, which flowed at 3.78 liters per minute. There were three turbines used: a small one with scoops sized 1.25”x1.25,” a medium one with scoops sized 1.375”x1.25,” and a large one with scoops sized 1.75”x1.5.” Once in the water source, the instantaneous voltage produced by the generator was recorded at each minute for a period of ten minutes. There were five tests conducted using each turbine with the river and the sink. The small turbine produced the greatest voltage in both tests by generating an average voltage of 1.216V in the river and 4.06V in the sink, compared with .99V and 3.738 being produced by the medium turbine, and 0.87 V and 3.419V being produced by the big turbine. As turbine size went up, the voltage being produced went down with statistical significance between each data set. The original hypothesis wasn’t supported because the large turbine produced the least voltage. This may be because the increased surface area of the scoops meant that the large turbine needed more water to be able to turn or because the weight of the turbine added resistance.

This manuscript contained two parts: an engineering portion where the authors built the portable hydropower generator, a multimeter, turbines, and other supplies necessary for testing, and a scientific testing portion where the authors performed experiments to compare the effect of turbine size on the voltage produced by a small hydropower generator. This is a good example of how you can use your inventions and engineered-devices to test a scientific hypothesis.

Ex. 2

Modeling Energy Produced by Solar Panels


As solar panels become increasingly popular, consumers want to know how to harvest more of the sun’s energy and how to increase the efficiency of solar panels. Determining the annual optimum tilt angle of a solar panel is a simple yet effective way to increase the energy generated. Our hypothesis was that if the tilt angle of the solar panel were set to the latitude of the location, then the solar panel would generate the most energy annually. A mathematical model was built to simulate the amount of solar energy generated in a day and in a year and was used as comparison to field data. Ten solar panels of varying angles were set outside and the voltage across a resistor was logged every five minutes to measure the energy generated by the solar panels. The model simulation supported the hypothesis, as the solar panel tilt angle of 40° generated the most energy and the latitude of the location of the experiment was around 40°. The field data supports the hypothesis at the experimental latitude and the results of the simulation confirm the field data, and shows that the solar panel tilt angle should be set within ±10° of the latitude to produce the most energy.

The manuscript also contains two parts: an optimization/theory-based calculation part and an experimental part. The authors tested the hypothesis generated from their mathematical model by performing an experiment with real solar panels.

2. Compare with existing method or device.

If an invention explores a different way to accomplish a goal more efficiently or more accurately, you can design an experiment where you compare your invention with the existing method, and test whether your invention outperforms the other method. However, you must include the following information for this approach to be acceptable:

  • Give a clear justification for why an improvement on the existing method/device was necessary. Give examples of problems associated with conventional method.
  • Predict specifically in which aspect you hypothesize your invention will outperform the previous device.
  • Give concrete reasons about why you think so and back your claim up with previous research or theoretical background.

These requirements are necessary to ensure that you have thought critically about your inventions.

Ex. 1

Developing a Portable, Reusable, and Inexpensive Magnesium-Air Fuel Cell

How to Revise:

For this manuscript, the authors can compare their invention to another portable fuel cell that already exists. However, there must be a clear rationale for why they did so. Is there a problem with an existing fuel cell in certain applications? They can introduce the current/conventional portable fuel cell and its shortcomings in the Introduction. Then they must hypothesize that their own invention will outperform the conventional fuel in those specific aspects and give concrete reasons why they believe so. The authors should then perform a series of experiment testing and comparing the function of the two fuel cells and attempt to show that their invention is better at various aspects. They may find that actually in some aspects, their invention does not outperform the conventional fuel cell–and that is completely fine! Finding results to the contrary of the hypothesis is an important part of the scientific process and JEI welcomes manuscripts with results that do not support the original hypothesis.

Links to Manuscripts

Feel free to contact the JEI Editorial Staff if you have any more questions about how to write a hypothesis-driven manuscript for JEI. Find the links to the full manuscripts mentioned above, as well as some other engineering-based manuscripts below:

Testing Various Synthetic And Natural Fiber Materials for soundproofing

More Efficient Helicopter Blades Based on Whale Tubercles